WorldWideScience

Sample records for ca ii ca

  1. The center-to-limb behavior of CaI lambda 6573 and [Ca II] lambda 7324

    International Nuclear Information System (INIS)

    Ayres, T.R.; Testerman, L.

    1978-01-01

    Center-to-limb measurements of the Ca I lambda 6573 intercombination line and the Ca II lambda 7324 forbidden line are compared with synthetic profiles based on a simple representation of the non-LTE Ca-Ca + ionization equilibrium. The effects of photoionization from low lying excited states of neutral calcium are found to reduce the sensitivity of the lambda 6573 center-to-limb behavior as a thermal structure diagnostic. The synthetic center-to-limb behavior is also sensitive to uncertainties in the nonthermal broadening. Nevertheless, the measured center-to-limb behavior of lambda 6573 favors a 'cool' photospheric model similar to the Vernazza, Avrett, and Loeser model M over hotter models based on the Ca II K wings. The non-LTE calcium abundance obtained from the disk center equivalent widths of lambda 6573 and lambda 7324 using the best fit model is Asub(Ca)approximately=2.1+-0.2x10 -6 (by number relative to hydrogen). Applications of these lines as diagnostics of the Ca-Ca + ionization equilibrium in other stars are briefly discussed. (Auth.)

  2. Ca II H and K emission from late-type stars

    International Nuclear Information System (INIS)

    Middlekoop, F.

    1982-01-01

    This thesis is based on a study of the Ca II H and K emission features of late main-sequence stars. In Chapter II it is shown that rotation periods can be determined from a modulation in the Ca II H and K signal for many stars in a broad range of spectral types. In Chapter III it is shown that a clear correlation exists between Ca II H and K emission and rotational velocity in active main-sequence stars. There is an indication for a (probably colour-dependent) critical velocity at which the Ca II H and K emission suddenly drops. Chapter IV discusses the dependence of Ca II H and K emission on the rotation rate for evolved stars. (Auth./C.F.)

  3. Macrocyclic receptor showing extremely high Sr(II)/Ca(II) and Pb(II)/Ca(II) selectivities with potential application in chelation treatment of metal intoxication.

    Science.gov (United States)

    Ferreirós-Martínez, Raquel; Esteban-Gómez, David; Tóth, Éva; de Blas, Andrés; Platas-Iglesias, Carlos; Rodríguez-Blas, Teresa

    2011-04-18

    Herein we report a detailed investigation of the complexation properties of the macrocyclic decadentate receptor N,N'-Bis[(6-carboxy-2-pyridil)methyl]-4,13-diaza-18-crown-6 (H(2)bp18c6) toward different divalent metal ions [Zn(II), Cd(II), Pb(II), Sr(II), and Ca(II)] in aqueous solution. We have found that this ligand is especially suited for the complexation of large metal ions such as Sr(II) and Pb(II), which results in very high Pb(II)/Ca(II) and Pb(II)/Zn(II) selectivities (in fact, higher than those found for ligands widely used for the treatment of lead poisoning such as ethylenediaminetetraacetic acid (edta)), as well as in the highest Sr(II)/Ca(II) selectivity reported so far. These results have been rationalized on the basis of the structure of the complexes. X-ray crystal diffraction, (1)H and (13)C NMR spectroscopy, as well as theoretical calculations at the density functional theory (B3LYP) level have been performed. Our results indicate that for large metal ions such as Pb(II) and Sr(II) the most stable conformation is Δ(δλδ)(δλδ), while for Ca(II) our calculations predict the Δ(λδλ)(λδλ) form being the most stable one. The selectivity that bp18c6(2-) shows for Sr(II) over Ca(II) can be attributed to a better fit between the large Sr(II) ions and the relatively large crown fragment of the ligand. The X-ray crystal structure of the Pb(II) complex shows that the Δ(δλδ)(δλδ) conformation observed in solution is also maintained in the solid state. The Pb(II) ion is endocyclically coordinated, being directly bound to the 10 donor atoms of the ligand. The bond distances to the donor atoms of the pendant arms (2.55-2.60 Å) are substantially shorter than those between the metal ion and the donor atoms of the crown moiety (2.92-3.04 Å). This is a typical situation observed for the so-called hemidirected compounds, in which the Pb(II) lone pair is stereochemically active. The X-ray structures of the Zn(II) and Cd(II) complexes show that

  4. The Influence of Mg(II and Ca(II Ions on Rutin Autoxidation in Weakly Alkaline Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Živanović Slavoljub C.

    2016-09-01

    Full Text Available Rutin (quercetin-3-O-rutinoside is one of the most abundant bioflavonoids with various biological and pharmacological activities. Considering the ubiquitous presence of Mg(II and Ca(II ions in biological systems we decided to investigate their influence on the autoxidation of rutin in weakly alkaline aqueous solutions. Changes in UV-Vis spectra recorded during the rutin autoxidation in aqueous solution at pH 8.4 revealed that this process was very slow in the absence of metal ions. The presence of Mg(II and, especially Ca(II ion, increased the transformation rate of rutin. UV-Vis spectra recorded after prolonged autoxidation indicated the formation of humic acidlike products in the presence of Mg(II and Ca(II ions. Four new compounds formed during the initial stage of rutin autoxidation in the presence of Mg(II and Ca(II ions were detected by HPLCDAD. Based on the analysis of their DAD UV-Vis spectra and comparison of their retention times with the retention time value for rutin, we concluded that the initial rutin transformation products were formed by the water addition on double bond in ring C and hydroxylation of ring B. A very small decrease of the initial rutin concentration (4% was observed by HPLC-DAD in the absence of metal ions for the period of 90 minutes. However, rutin concentration decrease was much larger in the presence of Mg(II and Ca(II ions (14% and 24%, respectively. The more pronounced effect of Ca(II ion on the rutin autoxidation may be explained by the stronger binding of Mg(II ion to rutin and thus greater stabilizing effect on reaction intermediates caused by its higher ionic potential (charge/ionic radius ratio in comparison to Ca(II ion. The results of this study may contribute to the better understanding of interactions of Mg(II and Ca(II ions with natural phenolic antioxidants which are important for their various biological activities.

  5. A dynamic model of interactions of Ca2+, calmodulin, and catalytic subunits of Ca2+/calmodulin-dependent protein kinase II.

    Directory of Open Access Journals (Sweden)

    Shirley Pepke

    2010-02-01

    Full Text Available During the acquisition of memories, influx of Ca2+ into the postsynaptic spine through the pores of activated N-methyl-D-aspartate-type glutamate receptors triggers processes that change the strength of excitatory synapses. The pattern of Ca2+influx during the first few seconds of activity is interpreted within the Ca2+-dependent signaling network such that synaptic strength is eventually either potentiated or depressed. Many of the critical signaling enzymes that control synaptic plasticity,including Ca2+/calmodulin-dependent protein kinase II (CaMKII, are regulated by calmodulin, a small protein that can bindup to 4 Ca2+ ions. As a first step toward clarifying how the Ca2+-signaling network decides between potentiation or depression, we have created a kinetic model of the interactions of Ca2+, calmodulin, and CaMKII that represents our best understanding of the dynamics of these interactions under conditions that resemble those in a postsynaptic spine. We constrained parameters of the model from data in the literature, or from our own measurements, and then predicted time courses of activation and autophosphorylation of CaMKII under a variety of conditions. Simulations showed that species of calmodulin with fewer than four bound Ca2+ play a significant role in activation of CaMKII in the physiological regime,supporting the notion that processing of Ca2+ signals in a spine involves competition among target enzymes for binding to unsaturated species of CaM in an environment in which the concentration of Ca2+ is fluctuating rapidly. Indeed, we showed that dependence of activation on the frequency of Ca2+ transients arises from the kinetics of interaction of fluctuating Ca2+with calmodulin/CaMKII complexes. We used parameter sensitivity analysis to identify which parameters will be most beneficial to measure more carefully to improve the accuracy of predictions. This model provides a quantitative base from which to build more complex dynamic

  6. Spectroscopic and thermal degradation behavior of Mg(II, Ca(II, Ba(II and Sr(II complexes with paracetamol drug

    Directory of Open Access Journals (Sweden)

    Moamen S. Refat

    2017-05-01

    Full Text Available Complexes of Mg(II, Ca(II, Ba(II and Sr(II with paracetamol drug were synthesized and characterized by elemental analysis, conductivity, UV–Vis, IR, and 1H NMR spectroscopy and thermal analysis, as well as screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as paracetamol behaves as a neutral bidentate ligand coordinated to the metal ions via the lone pair of electrons of nitrogen and carbonyl-O atoms of the amide group. From the microanalytical data, the stoichiometry of the complexes reacts with Mg(II, Ca(II, Ba(II and Sr(II by molar ratios (2:1 (paracetamol:metal ion. The thermal behavior (TG/DTG of the complexes was studied. The ligand and their metal complexes were screened against both of antibacterial and fungicidal activities.

  7. Fusion-activated Ca(2+ entry: an "active zone" of elevated Ca(2+ during the postfusion stage of lamellar body exocytosis in rat type II pneumocytes.

    Directory of Open Access Journals (Sweden)

    Pika Miklavc

    2010-06-01

    Full Text Available Ca(2+ is essential for vesicle fusion with the plasma membrane in virtually all types of regulated exocytoses. However, in contrast to the well-known effects of a high cytoplasmic Ca(2+ concentration ([Ca(2+](c in the prefusion phase, the occurrence and significance of Ca(2+ signals in the postfusion phase have not been described before.We studied isolated rat alveolar type II cells using previously developed imaging techniques. These cells release pulmonary surfactant, a complex of lipids and proteins, from secretory vesicles (lamellar bodies in an exceptionally slow, Ca(2+- and actin-dependent process. Measurements of fusion pore formation by darkfield scattered light intensity decrease or FM 1-43 fluorescence intensity increase were combined with analysis of [Ca(2+](c by ratiometric Fura-2 or Fluo-4 fluorescence measurements. We found that the majority of single lamellar body fusion events were followed by a transient (t(1/2 of decay = 3.2 s rise of localized [Ca(2+](c originating at the site of lamellar body fusion. [Ca(2+](c increase followed with a delay of approximately 0.2-0.5 s (method-dependent and in the majority of cases this signal propagated throughout the cell (at approximately 10 microm/s. Removal of Ca(2+ from, or addition of Ni(2+ to the extracellular solution, strongly inhibited these [Ca(2+](c transients, whereas Ca(2+ store depletion with thapsigargin had no effect. Actin-GFP fluorescence around fused LBs increased several seconds after the rise of [Ca(2+](c. Both effects were reduced by the non-specific Ca(2+ channel blocker SKF96365.Fusion-activated Ca(2+entry (FACE is a new mechanism that leads to [Ca(2+](c transients at the site of vesicle fusion. Substantial evidence from this and previous studies indicates that fusion-activated Ca(2+ entry enhances localized surfactant release from type II cells, but it may also play a role for compensatory endocytosis and other cellular functions.

  8. Oxidized CaMKII (Ca2+/Calmodulin-Dependent Protein Kinase II) Is Essential for Ventricular Arrhythmia in a Mouse Model of Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Wang, Qiongling; Quick, Ann P; Cao, Shuyi; Reynolds, Julia; Chiang, David Y; Beavers, David; Li, Na; Wang, Guoliang; Rodney, George G; Anderson, Mark E; Wehrens, Xander H T

    2018-04-01

    Duchenne muscular dystrophy patients are prone to ventricular arrhythmias, which may be caused by abnormal calcium (Ca 2+ ) homeostasis and elevated reactive oxygen species. CaMKII (Ca 2+ /calmodulin-dependent protein kinase II) is vital for normal Ca 2+ homeostasis, but excessive CaMKII activity contributes to abnormal Ca 2+ homeostasis and arrhythmias in cardiomyocytes. Reactive oxygen species induce CaMKII to become autonomously active. We hypothesized that genetic inhibition of CaMKII oxidation (ox-CaMKII) in a mouse model of Duchenne muscular dystrophy can alleviate abnormal Ca 2+ homeostasis, thus, preventing ventricular arrhythmia. The objective of this study was to test if selective loss of ox-CaMKII affects ventricular arrhythmias in the mdx mouse model of Duchenne muscular dystrophy. 5-(6)-Chloromethyl-2,7-dichlorodihydrofluorescein diacetate staining revealed increased reactive oxygen species production in ventricular myocytes isolated from mdx mice, which coincides with elevated ventricular ox-CaMKII demonstrated by Western blotting. Genetic inhibition of ox-CaMKII by knockin replacement of the regulatory domain methionines with valines (MM-VV [CaMKII M281/282V]) prevented ventricular tachycardia in mdx mice. Confocal calcium imaging of ventricular myocytes isolated from mdx :MM-VV mice revealed normalization of intracellular Ca 2+ release events compared with cardiomyocytes from mdx mice. Abnormal action potentials assessed by optical mapping in mdx mice were also alleviated by genetic inhibition of ox-CaMKII. Knockout of the NADPH oxidase regulatory subunit p47 phox normalized elevated ox-CaMKII, repaired intracellular Ca 2+ homeostasis, and rescued inducible ventricular arrhythmias in mdx mice. Inhibition of reactive oxygen species or ox-CaMKII protects against proarrhythmic intracellular Ca 2+ handling and prevents ventricular arrhythmia in a mouse model of Duchenne muscular dystrophy. © 2018 American Heart Association, Inc.

  9. Physical conditions in CaFe interstellar clouds

    OpenAIRE

    Gnacinski, P.; Krogulec, M.

    2007-01-01

    Interstellar clouds that exhibit strong Ca I and Fe I lines were called CaFe clouds. The ionisation equilibrium equations were used to model the column densities of Ca II, Ca I, K I, Na I, Fe I and Ti II in CaFe clouds. The chemical composition of CaFe clouds is that of the Solar System and no depletion of elements onto dust grains is seen. The CaFe clouds have high electron densities n=1 cm^-3 that leads to high column densities of neutral Ca and Fe.

  10. Clinical evaluation of the Byk LIA-mat CA125 II assay: discussion of a reference value.

    Science.gov (United States)

    Bonfrer, J M; Korse, C M; Verstraeten, R A; van Kamp, G J; Hart, G A; Kenemans, P

    1997-03-01

    The Byk LIA-mat CA125 II assay was compared with the Centocor IRMA CA125 II. Serum samples studied (n = 1012) were obtained from 652 apparently healthy females, 61 pregnant women, and 299 patients with benign and malignant gynecological tumors. The CA125 II assay value at the 95th percentile of the total healthy group was 29 kU/L for the LIA-mat and 32 kU/L for the Centocor assay. For the LIA-mat assay the 95th percentile was 31 kU/L (Centocor 36 kU/L) for the group 55 years of age. By using ROC curves we found the optimal pretreatment Byk LIA-mat CA125 II value differentiating between benign and malignant ovarian tumors to be 95 kU/L. Pretreatment CA125 values > 1000 kU/L were detected in serum samples of patients with advanced epithelial ovarian cancer.

  11. Removal of Ca(II) and Mg(II) from potassium chromate solution on Amberlite IRC 748 synthetic resin by ion exchange

    International Nuclear Information System (INIS)

    Yu Zhihui; Qi Tao; Qu Jingkui; Wang Lina; Chu Jinglong

    2009-01-01

    Experimental measurements have been made on the batch ion exchange of Ca(II) and Mg(II) from potassium chromate solution using cation exchanger of Amberlite IRC 748 as K + form. The ion exchange behavior of two alkaline-earth metals on the resin, depending on contact time, pH, temperature and resin dosage was studied. The adsorption isotherms were described by means of the Langmuir and Freundlich isotherms. For Ca(II) ion, the Langmuir model represented the adsorption process better than the Freundlich model. The maximum ion exchange capacity was found to be 47.21 mg g -1 for Ca(II) and 27.70 mg g -1 for Mg(II). The kinetic data were tested using Lagergren-first-order and pseudo-second-order kinetic models. Kinetic data correlated well with the pseudo-second-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. Various thermodynamic parameters such as Gibbs free energy (ΔG o ), enthalpy (ΔH o ) and entropy (ΔS o ) were also calculated. These parameters showed that the ion exchange of Ca(II) and Mg(II) from potassium chromate solution was feasible, spontaneous and endothermic process in nature. The activation energy of ion-exchange (E a ) was determined as 12.34 kJ mol -1 for Ca(II) and 9.865 kJ mol -1 for Mg(II) according to the Arrhenius equation.

  12. Developmental distribution of CaM kinase II in the antennal lobe of the sphinx moth Manduca sexta.

    Science.gov (United States)

    Lohr, Christian; Bergstein, Sandra; Hirnet, Daniela

    2007-01-01

    The antennal lobe (primary olfactory center of insects) is completely reorganized during metamorphosis. This reorganization is accompanied by changing patterns of calcium signaling in neurons and glial cells. In the present study, we investigated the developmental distribution of a major calcium-dependent protein, viz., calcium/calmodulin-dependent protein kinase II (CaM kinase II), in the antennal lobe of the sphinx moth Manduca sexta by using a monoclonal antibody. During synaptogenesis (developmental stages 6-10), we found a redistribution of CaM kinase II immunoreactivity, from a homogeneous distribution in the immature neuropil to an accumulation in the neuropil of the glomeruli. CaM kinase II immunoreactivity was less intense in olfactory receptor axons of the antennal nerve and antennal lobe glial cells. Western blot analysis revealed a growing content of CaM kinase II in antennal lobe tissue throughout metamorphosis. Injection of the CaM kinase inhibitor KN-93 into pupae resulted in a reduced number of antennal lobe glial cells migrating into the neuropil to form borders around glomeruli. The results suggest that CaM kinase II is involved in glial cell migration.

  13. Mechanism of Ca2+/calmodulin-dependent kinase II regulation of AMPA receptor gating

    DEFF Research Database (Denmark)

    Kristensen, Anders Skov; Jenkins, Meagan A; Banke, Tue G

    2011-01-01

    The function, trafficking and synaptic signaling of AMPA receptors are tightly regulated by phosphorylation. Ca(2+)/calmodulin-dependent kinase II (CaMKII) phosphorylates the GluA1 AMPA receptor subunit at Ser831 to increase single-channel conductance. We show that CaMKII increases the conductanc...

  14. Ca(2+-dependent regulation of the Ca(2+ concentration in the myometrium mitochondria. II. Ca(2+ effects on mitochondria membranes polarization and [Ca(2+](m

    Directory of Open Access Journals (Sweden)

    L. G. Babich

    2017-06-01

    Full Text Available It is known that Ca2+ accumulation in the mitochondria undergoes complex regulation by Ca2+ itself. But the mechanisms of such regulation are still discussed. In this paper we have shown that Ca ions directly or indirectly regulate the level of myometrium mitochondria membranes polarization. The additions of 100 µM Ca2+ were accompanied by depolarization of the mitochondria membranes. The following experiments were designed to study the impact of Ca2+ on the myometrium mitochondria [Ca2+]m. Isolated myometrium mitochondria were preincubated without or with 10 μM Са2+ followed by 100 μM Са2+ addition. Experiments were conducted in three mediums: without ATP and Mg2+ (0-medium, in the presence of 3 mM Mg2+ (Mg-medium and 3 mM Mg2+ + 3 mM ATP (Mg,ATP-medium. It was shown that the effects of 10 μM Са2+ addition were different in different mediums, namely in 0- and Mg-medium the [Ca2+]m values increased, whereas in Mg,ATP-medium statistically reliable changes were not registered. Preincubation of mitochondria with 10 μM Са2+ did not affect the [Ca2+]m value after the addition of 100 μM Са2+. The [Ca2+]m values after 100 μM Са2+ addition were the same in 0- and Mg,ATP-mediums and somewhat lower in Mg-medium. Preliminary incubation of mitochondria with 10 μM Са2+ in 0- and Mg-mediums reduced changes of Fluo 4 normalized fluorescence values that were induced by 100 μM Са2+ additions, but in Mg,ATP-medium such differences were not recorded. It is concluded that Са2+ exchange in myometrium mitochondria is regulated by the concentration of Ca ions as in the external medium, so in the matrix of mitochondria. The medium composition had a significant impact on the [Са2+]m values in the absence of exogenous cation. It is suggested that light increase of [Са2+]m before the addition of 100 μM Са2+ may have a positive effect on the functional activity of the mitochondria.

  15. PROBABLE IDENTIFICATION OF THE ON-DISK COUNTERPART OF SPICULES IN HINODE Ca II H OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    De Wijn, A. G., E-mail: dwijn@ucar.edu [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2012-09-20

    I present a study of high-resolution time series of Ca II H images and Fe I 630.15 nm spectra taken with the Solar Optical Telescope on the Hinode spacecraft. There is excellent correspondence between the Ca II H and the Fe I line core intensity, except tenuous emission around the network field concentrations in the former that is absent in the latter. Analysis of on-disk observations and a comparison with limb observations suggests that this 'network haze' corresponds to spicules, and likely to type-II spicules in particular. They are known to appear in emission in on-disk broadband Ca II H diagnostics and the network haze is strongest in those areas where features similar to type-II spicules are produced in simulations.

  16. Up-regulation of Ca2+/CaMKII/CREB signaling in salicylate-induced tinnitus in rats.

    Science.gov (United States)

    Zhao, Jiuhan; Wang, Biao; Wang, Xiaohong; Shang, Xiuli

    2018-02-09

    The purpose of the study was to investigate the changes of Ca 2+ /calmodulin-dependent protein kinases II (CaMKII)/cAMP response element-binding protein (CREB) signaling pathway in a rat tinnitus model. Eighteen Wistar rats were randomly divided into three groups: normal control (NC), normal saline (NS), and tinnitus model (TM) groups. Tinnitus model was induced by intraperitoneal injection of salicylate. The concentration of intracellular calcium level in auditory cortex cells was determined using Fura-2 acetoxymethyl ester (Fura-2 AM) method with fluorospectrophotometer. Expressions of calmodulin (CaM), N-methyl-D-aspartate receptor 2B subunit (NR2B), calcium-calmodulin kinase II (CaMKII), and cAMP response element-binding protein (CREB) were detected with Western blot. Tinnitus model was successfully established by the intraperitoneal administration of salicylate in rats. Compared with rats in NC and NS groups, salicylate administration significantly elevated CaM, NR2B, phospho-CaMKII and phospho-CREB expression in auditory cortex from tinnitus model group (p salicylate administration causes tinnitus symptoms and elevates Ca 2+ /CaMKII/CREB signaling pathway in auditory cortex cells. Our study likely provides a new understanding of the development of tinnitus.

  17. CaII Κ Imaging to Understand UV Irradiance Variability

    Indian Academy of Sciences (India)

    tribpo

    the observational details, a new method of analysis, and the preliminary results of the. CaII Κ spectroheliograms of the National Solar Observatory at Sacramento Peak. (NSO/Sac Peak). The main purpose of the present paper is to separate and to derive the relative intensity and area of various chromospheric features from ...

  18. Integrated-light spectroscopy of globular clusters at the infrared Ca II lines

    Science.gov (United States)

    Armandroff, Taft E.; Zinn, Robert

    1988-01-01

    Integrated-light spectroscopy has been obtained for 27 globular clusters at the Ca II IR triplet. Line strengths and radial velocities have been measured from the spectra. For the well-studied clusters in the sample, the strength of the Ca II lines is very well correlated with previous metallicity estimates. Thus, the triplet is useful as a metallicity indicator in globular cluster integrated-light spectra. The greatly reduced effect of interstellar extinction at these wavelengths (compared to the blue region of the spectrum) has permitted observations of some of the most heavily reddened clusters in the Galaxy. For several such clusters, the Ca II triplet metallicities are in poor agreement with metallicity estimates from IR photometry by Malkan (1981). The strength of an interstellar band at 8621A has been used to estimate the amount of extinction towards these clusters. Using the new metallicity and radial-velocity data, the metallicity distribution, kinematics, and spatial distribution of the disk globular cluster system have been analyzed. Results very similar to those of Zinn (1985) have been found. The relation of the disk globulars to the stellar thick disk is discussed.

  19. SYNTHESIS, CHARACTERIZATION AND ANTITUMOR ACTIVITY OF A Ca (II COORDINATION POLYMER BASED ON 3-AMINO-2-PYRAZINECARBOXYLIC ACID

    Directory of Open Access Journals (Sweden)

    XI-SHI TAI

    2015-10-01

    Full Text Available A new Ca(II coordination polymer has been obtained by reaction of Ca(ClO42·H2O with 3-amino-2-pyrazinecarboxylic acid in CH3CH2OH/H2O. It was characterized by IR, 1HNMR, thermal analysis and X-ray single crystal diffraction analysis. X-ray analysis reveals that each Ca(II center is seven-coordination with a N2O5 distorted pentagonal bipyramidal coordination environment. The Ca(II ions are linked through the O atoms of 3-amino-2-pyrazinecarboxylic acid ligands to form 1D chain structure. And then a 3D network structure is constructed by hydrogen bonds and π-π stacking. The antitumor activity of 3-amino-2-pyrazinecarboxylic acid ligand and its Ca(II coordination polymer against human intestinal adenocarcinoma HCT-8 cells, lung adenocarcinoma HCT-116 cells and human lung adenocarcinoma A549 cells line have been investigated.

  20. Modulation pf pulmonary surfactant secretion from alveolar type II cells by cytoplasmic free calcium ([Ca2+]/sub i/)

    International Nuclear Information System (INIS)

    Sano, K.; Voelker, D.R.; Mason, R.J.

    1986-01-01

    Ca 2+ is regulator of a variety of cellular functions including exocytosis. TPA and terbutaline have been shown to stimulate surfactant secretion from alveolar type II cells. The authors examined changes in [Ca 2+ ]/sub i/ and surfactant secretion by secretagogues in primary culture of alveolar type II cells. Cells were isolated from adult rats and were cultured for 24 h with 3 H-choline to label phosphatidylcholine. Percent secretion was determined by counting the lipids of cells and medium; cytotoxicity was excluded by measuring lactate dehydrogenase as cells and medium. [Ca 2+ ]/sub i/ was determined by measuring quin2 fluroescence of cells cultured on a glass coverslip. Ionomycin increased secretion as well as [Ca 2+ ] in dose dependent manner at the concentration from 25 to 400 nM. Ionomycin (50 nM) increased terbutaline-induced secretion in a synergistic manner but only increased TPA-induced secretion in an additive manner. Terbutaline mobilized [Ca 2+ ]/sub i/ from intracellular stores and increased [Ca 2+ ]/sub i/ by 20% from a basal level of 140 nM. TPA itself did not change [Ca 2+ ]/sub i/ but inhibited the effect of terbutaline on [Ca 2+ ]/sub i/. Loading of quin2 in the absence of extracellular calcium lowered [Ca 2+ ]/sub i/ from 143 nM to 31 nM. Lowering [Ca 2+ ]/sub i/ inhibited TPA- or terbutaline-induced secretion by 22% and 40% respectively. These results indicate that [Ca 2+ ]/sub i/ effects cAMp-induced secretion more than protein kinase C-mediated secretion in alveolar type II cells

  1. PMR spectroscopy of Ca(II) complexes of ethylenediamine-N,N,N',N' - tetraacetic acid

    International Nuclear Information System (INIS)

    Novomesky, P.; Balgavy, P.; Majer, J.

    1977-01-01

    Proton magnetic resonance spectra for the EDTA complexes of Ca(II) were measured in aqueous solutions as a function of solution pH. It follows from the analysis of chemical shift changes that the nitrogen atoms rather than the carboxylate groups are protonated (as the pH is lowered) in the tetraanion of EDTA. The same conclusion follows for the protonization of the [CaEDTA] 2- complex in the acid pH range where the hydrogen complex [CaH(EDTA)] - is formed. The formation of [Ca(OH)EDTA] 3- was not observed at pH less than 12.6, at [CaEDTA] 2- concentration of 0.5 mol/l. In solutions with a metal-to-ligand molar ratio 1:1.5 two sets of resonance signals appear in the pH range from 12.8 to 6.0, the former for the free ligand and the latter for the stable [CaEDTA] 2- complex. However, from pH 6.0 to 4.35 only one set of broadened signals was observed, which indicates that an exchange process between free ligand, normal [CaEDTA] 2- complex and [CaH(EDTA)] - takes place. (author)

  2. New 3D gas density maps of NaI and CaII interstellar absorption within 300 pc

    Science.gov (United States)

    Welsh, B. Y.; Lallement, R.; Vergely, J.-L.; Raimond, S.

    2010-02-01

    Aims: We present new high resolution (R > 50 000) absorption measurements of the NaI doublet (5889-5895 Å) along 482 nearby sight-lines, in addition to 807 new measurements of the CaII K (3933 Å) absorption line. We have combined these new data with previously reported measurements to produce a catalog of absorptions towards a total of 1857 early-type stars located within 800 pc of the Sun. Using these data we have determined the approximate 3-dimensional spatial distribution of neutral and partly ionized interstellar gas density within a distance-cube of 300 pc from the Sun. Methods: All newly recorded spectra were analyzed by means of a multi-component line profile-fitting program, in most cases using simultaneous fits to the line doublets. Normalized absorption profiles were fitted by varying the velocity, doppler width and column density for all intervening interstellar clouds. The resulting total column densities were then used in conjunction with the Hipparcos distances of the target stars to construct inversion maps of the 3D spatial density distribution of the NaI and CaII bearing gas. Results: A plot of the equivalent width of NaI versus distance reveals a wall of neutral gas at ~80 pc that can be associated with the boundary wall to the central rarefied Local Cavity region. In contrast, a similar plot for the equivalent width of CaII shows no sharply increasing absorption at 80 pc, but instead we observe a slowly increasing value of CaII equivalent width with increasing sight-line distance sampled. Low values for the volume density of NaI (nNaI values in the range 10-8 >nNaI > 10-10 cm-3 are found for sight-lines with distance >300 pc. Both high and low values of the volume density of CaII (nCaII) are found for sight-lines 100 pc a value of nCaII ~ 10-9 cm-3 is typical for most sight-lines, indicating that the distribution of CaII bearing gas is fairly uniform throughout the general ISM. Our three maps of the 3D spatial distribution of local neutral Na

  3. Calcium EXAFS establishes the Mn-Ca cluster in the oxygen-evolving complex of Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Cinco, Roehl M.; McFarlane Holman, Karen L.; Robblee, John H.; Yano, Junko; Pizarro, Shelly A.; Bellacchio, Emanuele; Sauer, Kenneth; Yachandra, Vittal K.

    2002-08-02

    The proximity of Ca to the Mn cluster of the photosynthetic water-oxidation complex is demonstrated by X-ray absorption spectroscopy. We have collected EXAFS data at the Ca K-edge using active PS II membrane samples that contain approximately 2 Ca per 4 Mn. These samples are much less perturbed than previously investigated Sr-substituted samples, which were prepared subsequent to Ca depletion. The new Ca EXAFS clearly shows backscattering from Mn at 3.4 angstroms, a distance that agrees with that surmised from previously recorded Mn EXAFS. This result is also consistent with earlier related experiments at the Sr K-edge, using samples that contained functional Sr, that show Mn is {approx}; 3.5 angstroms distant from Sr. The totality of the evidence clearly advances the notion that the catalytic center of oxygen evolution is a Mn-Ca heteronuclear cluster.

  4. Coordination and structure of Ca(II)-acetate complexes in aqueous solution studied by a combination of Raman and XAFS spectroscopies

    Science.gov (United States)

    Muñoz Noval, Álvaro; Nishio, Daisuke; Kuruma, Takuya; Hayakawa, Shinjiro

    2018-06-01

    The determination of the structure of Ca(II)-acetate in aqueous solution has been addressed by combining Raman and X-ray absorption fine structure spectroscopies. The pH-dependent speciation of the acetate/Ca(II) system has been studied observing modifications in specific Raman bands of the carboxyl group. The current results evidence the Ca(II)-acetate above acetate pKa forms a bidentate complex and presents a coordination 6, in which the Ca-O shell radius decrease of about 0.1 Å with respect the hydrated Ca2+ with coordination 8. The experimental results show the OCO angle of the carboxyl in the complex is close to 124°, being the OCaO angle about 60°.

  5. Rat vas deferens SERCA2 is modulated by Ca2+/calmodulin protein kinase II-mediated phosphorylation

    International Nuclear Information System (INIS)

    Rodriguez, J.B.R.; Muzi-Filho, H.; Valverde, R.H.F.; Quintas, L.E.M.; Noel, F.; Einicker-Lamas, M.; Cunha, V.M.N.

    2013-01-01

    Ca 2+ pumps are important players in smooth muscle contraction. Nevertheless, little information is available about these pumps in the vas deferens. We have determined which subtype of sarco(endo)plasmic reticulum Ca 2+ -ATPase isoform (SERCA) is expressed in rat vas deferens (RVD) and its modulation by calmodulin (CaM)-dependent mechanisms. The thapsigargin-sensitive Ca 2+ -ATPase from a membrane fraction containing the highest SERCA levels in the RVD homogenate has the same molecular mass (∼115 kDa) as that of SERCA2 from the rat cerebellum. It has a very high affinity for Ca 2+ (Ca 0.5 = 780 nM) and a low sensitivity to vanadate (IC 50 = 41 µM). These facts indicate that SERCA2 is present in the RVD. Immunoblotting for CaM and Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) showed the expression of these two regulatory proteins. Ca 2+ and CaM increased serine-phosphorylated residues of the 115-kDa protein, indicating the involvement of CaMKII in the regulatory phosphorylation of SERCA2. Phosphorylation is accompanied by an 8-fold increase of thapsigargin-sensitive Ca 2+ accumulation in the lumen of vesicles derived from these membranes. These data establish that SERCA2 in the RVD is modulated by Ca 2+ and CaM, possibly via CaMKII, in a process that results in stimulation of Ca 2+ pumping activity

  6. MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKIIδ

    International Nuclear Information System (INIS)

    Cha, Min-Ji; Jang, Jin-Kyung; Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon; Lee, Chang Yeon; Park, Jun-Hee; Lee, Jiyun; Seo, Hyang-Hee; Choi, Eunhyun; Jeon, Woo-min; Hwang, Hye Jin; Shin, Hyun-Taek

    2013-01-01

    Highlights: •CaMKIIδ mediates H 2 O 2 -induced Ca 2+ overload in cardiomyocytes. •miR-145 can inhibit Ca 2+ overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca 2+ ) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca 2+ signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca 2+ -mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H 2 O 2 -mediated Ca 2+ overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca 2+ overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca 2+ -related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca 2+ overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses

  7. Tracers of Chromospheric Structure. I. Observations of Ca II K and Hα in M Dwarfs

    Science.gov (United States)

    Walkowicz, Lucianne M.; Hawley, Suzanne L.

    2009-02-01

    We report on our observing program4This paper is based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. to capture simultaneous spectra of Ca II and Balmer lines in a sample of nearby M3 dwarfs. Our goal is to investigate the chromospheric temperature structure required to produce these lines at the observed levels. We find a strong positive correlation between instantaneous measurements of Ca II K and the Balmer lines in active stars, although these lines may not be positively correlated in time-resolved measurements. The relationship between Hα and Ca II K remains ambiguous for weak and intermediate activity stars, with Hα absorption corresponding to a range of Ca II K emission. A similar relationship is also observed between Ca II K and the higher-order Balmer lines. As our sample consists of a single spectral type, correlations between these important chromospheric tracers cannot be ascribed to continuum effects, as suggested by other authors. These data confirm prior nonsimultaneous observations of the Hα line behavior with increasing activity, showing an initial increase in the Hα absorption with increasing Ca II K emission, prior to Hα filling in and eventually becoming a pure emission line in the most active stars. We also compare our optical measurements with archival UV and X-ray measurements, finding a positive correlation between the chromospheric and coronal emission for both high and intermediate activity stars. We compare our results with previous determinations of the active fraction of low-mass stars

  8. Amorphous manganese-calcium oxides as a possible evolutionary origin for the CaMn₄ cluster in photosystem II.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi

    2011-06-01

    In this paper a few calcium-manganese oxides and calcium-manganese minerals are studied as catalysts for water oxidation. The natural mineral marokite is also studied as a catalyst for water oxidation for the first time. Marokite is made up of edge-sharing Mn(3+) in a distorted octahedral environment and eight-coordinate Ca(2+) centered polyhedral layers. The structure is similar to recent models of the oxygen evolving complex in photosystem II. Thus, the oxygen evolving complex in photosystem II does not have an unusual structure and could be synthesized hydrothermally. Also in this paper, oxygen evolution is studied with marokite (CaMn₂O₄), pyrolusite (MnO₂) and compared with hollandite (Ba(0.2)Ca(0.15)K(0.3)Mn(6.9)Al(0.2)Si(0.3)O(16)), hausmannite (Mn₃O₄), Mn₂O₃.H₂O, Ca Mn₃O₆.H₂O, CaMn₄O₈.H₂O, CaMn₂O₄.H₂O and synthetic marokite (CaMn₂O₄). I propose that the origin of the oxygen evolving complex in photosystem II resulted from absorption of calcium and manganese ions that were precipitated together in the archean oceans by protocyanobacteria because of changing pH from ~5 to ~8-10. As reported in this paper, amorphous calcium-manganese oxides with different ratios of manganese and calcium are effective catalysts for water oxidation. The bond types and lengths of the calcium and manganese ions in the calcium-manganese oxides are directly comparable to those in the OEC. This primitive structure of these amorphous calcium-manganese compounds could be changed and modified by environmental groups (amino acids) to form the oxygen evolving complex in photosystem II.

  9. Methodology to obtain exchange properties of the calcite surface-Application to major and trace elements: Ca(II), HCO3-, and Zn(II)

    International Nuclear Information System (INIS)

    Tertre, E.; Beaucaire, C.; Juery, A.; Ly, J.; Tertre, E.; Beaucaire, C.; Juery, A.; Ly, J.

    2010-01-01

    Sorption of inorganic elements onto carbonate minerals has been intensively described in the literature by two reaction steps: (1) a first one rapid and completed within a few hours and (2) a second one slower, eventually irreversible, and occurring at a constant rate. The first step is often attributed to an ion-exchange process, but its reversibility is rarely investigated. Consequently, discrimination of the global sorption phenomenon into two different mechanisms is not always justified. In this study, we investigated, by batch experiments, both sorption and desorption of Ca(II), HCO 3 - , and Zn(II), radiolabeled with isotopes 45 Ca(II), H 14 CO 3 - , and 65 Zn(II), respectively, onto synthetic pure calcite. Solutions were pre-equilibrated with atmospheric p(CO 2 ) and saturated with respect to calcite. Therefore, our purpose was to: (1) obtain experimental distribution coefficients of major elements (Ca(II) and HCO 3 - ) and a trace element (Zn(II)) onto calcite from sorption and desorption experiments, (2) test the validity of a first-occurring ion-exchange process generally noted in the literature, by calculating distribution coefficients for the 'sole' exchange process, and (3) quantify the amounts of Ca(II), HCO 3 - , and Zn(II) sorbed on the calcite surface by the sole 'exchange process' and compare them with surface crystallochemical data. Ca(II) or HCO 3 - sorption experimental data suggest that a significant fraction of these two elements was sorbed irreversibly onto or in the calcite. By using a method based on isotopic ratios, the Ca(II) or HCO 3 - concentrations, which are reversibly adsorbed on the calcite, have been quantified. These concentrations are respectively estimated at 4. 0 ± 2. 0 * 10 -4 and 7. 0 ± 1. 5 * 10 -4 mol/kg. The obtained Ca(II) surface concentration value is one order of magnitude lower than the one obtained from isotopic measurement by former authors [Geochim. Cosmochim. Acta 55 (1991) 1549; Geochim. Cosmochim. Acta 51

  10. Spectroscopic and thermal degradation behavior of Mg(II), Ca(II), Ba(II) and Sr(II) complexes with paracetamol drug

    OpenAIRE

    Moamen S. Refat; Gehad G. Mohamed; Mohamed Y. El-Sayed; Hamada M.A. Killa; Hammad Fetooh

    2017-01-01

    Complexes of Mg(II), Ca(II), Ba(II) and Sr(II) with paracetamol drug were synthesized and characterized by elemental analysis, conductivity, UV–Vis, IR, and 1H NMR spectroscopy and thermal analysis, as well as screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as paracetamol behaves as a neutral bidentate ligand coordinated to the metal ions via the lone pair of electrons of nitrogen and carbonyl-O atoms of the amide group. From the microanalytical dat...

  11. Rat vas deferens SERCA2 is modulated by Ca{sup 2+}/calmodulin protein kinase II-mediated phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.B.R.; Muzi-Filho, H. [Programa de Farmacologia e Inflamação, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Valverde, R.H.F. [Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Quintas, L.E.M. [Programa de Farmacologia e Inflamação, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Noel, F. [Programa de Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Einicker-Lamas, M. [Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Rio de Janeiro, RJ (Brazil); Cunha, V.M.N. [Programa de Farmacologia e Inflamação, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    2013-03-19

    Ca{sup 2+} pumps are important players in smooth muscle contraction. Nevertheless, little information is available about these pumps in the vas deferens. We have determined which subtype of sarco(endo)plasmic reticulum Ca{sup 2+}-ATPase isoform (SERCA) is expressed in rat vas deferens (RVD) and its modulation by calmodulin (CaM)-dependent mechanisms. The thapsigargin-sensitive Ca{sup 2+}-ATPase from a membrane fraction containing the highest SERCA levels in the RVD homogenate has the same molecular mass (∼115 kDa) as that of SERCA2 from the rat cerebellum. It has a very high affinity for Ca{sup 2+} (Ca{sub 0.5} = 780 nM) and a low sensitivity to vanadate (IC{sub 50} = 41 µM). These facts indicate that SERCA2 is present in the RVD. Immunoblotting for CaM and Ca{sup 2+}/calmodulin-dependent protein kinase II (CaMKII) showed the expression of these two regulatory proteins. Ca{sup 2+} and CaM increased serine-phosphorylated residues of the 115-kDa protein, indicating the involvement of CaMKII in the regulatory phosphorylation of SERCA2. Phosphorylation is accompanied by an 8-fold increase of thapsigargin-sensitive Ca{sup 2+} accumulation in the lumen of vesicles derived from these membranes. These data establish that SERCA2 in the RVD is modulated by Ca{sup 2+} and CaM, possibly via CaMKII, in a process that results in stimulation of Ca{sup 2+} pumping activity.

  12. MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKIIδ

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Min-Ji [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jang, Jin-Kyung [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Lee, Chang Yeon; Park, Jun-Hee [Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, 50 Yonsei-ro, Seodamun-gu, Seoul 120-759 (Korea, Republic of); Lee, Jiyun; Seo, Hyang-Hee [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Choi, Eunhyun [Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University Health System, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jeon, Woo-min [Department of Animal Resource, Sahmyook University, Seoul 139-742 (Korea, Republic of); Hwang, Hye Jin [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Shin, Hyun-Taek [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); and others

    2013-06-14

    Highlights: •CaMKIIδ mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca{sup 2+} overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

  13. Dual Nuclear/Fluorescence Imaging Potantial of Zinc(II) Phthalocyanine in MIA PaCa-2 Cell Line.

    Science.gov (United States)

    Lambrecht, Fatma Yurt; Ince, Mine; Er, Ozge; Ocakoglu, Kasim; Sarı, Fatma Aslıhan; Kayabasi, Cagla; Gunduz, Cumhur

    2016-01-01

    Pancreatic cancer is very common and difficult to diagnose in early stage. Imaging systems for diagnosing cancer have many disadvantages. However, combining different imaging modalities offers synergistic advantages. Optical imaging is the most multidirectional and widely used imaging modality in both clinical practice and research. In present study, Zinc(II) phthalocyanine [Zn(II)Pc] was synthesized, labeled with iodine- 131 and in vitro study was carried out. The intracellular uptake studies of radiolabeled Zn(II)Pc were performed in WI-38 [ATCC CCL-75™, tissue: human fibroblast lung] and MIA PaCa-2 [ATCC CRL-1420™, tissue: human epithelial pancreas carcinoma] cell lines. The intracellular uptake efficiency of radiolabeled Zn(II)Pc in MIA PaCa-2 cells was determined two times higher than WI-38 cells. Also, fluorescence imaging (FI) efficiency of synthesized Zn(II)Pc was investigated in MIA PaCa-2 cells and significant uptake was observed. Zn(II)Pc might be used as a new agent for dual fluorescence/nuclear imaging for pancreatic cancer. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Slender Ca ii H Fibrils Mapping Magnetic Fields in the Low Solar Chromosphere

    Energy Technology Data Exchange (ETDEWEB)

    Jafarzadeh, S.; Rutten, R. J.; Szydlarski, M. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Solanki, S. K.; Wiegelmann, T.; Riethmüller, T. L.; Noort, M. van; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J. [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Iniesta, J. C. del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apartado de Correos 3004, E-18080 Granada (Spain); Knölker, M. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Pillet, V. Martínez [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Schmidt, W., E-mail: shahin.jafarzadeh@astro.uio.no [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany)

    2017-04-01

    A dense forest of slender bright fibrils near a small solar active region is seen in high-quality narrowband Ca ii H images from the SuFI instrument onboard the Sunrise balloon-borne solar observatory. The orientation of these slender Ca ii H fibrils (SCF) overlaps with the magnetic field configuration in the low solar chromosphere derived by magnetostatic extrapolation of the photospheric field observed with Sunrise/IMaX and SDO/HMI. In addition, many observed SCFs are qualitatively aligned with small-scale loops computed from a novel inversion approach based on best-fit numerical MHD simulation. Such loops are organized in canopy-like arches over quiet areas that differ in height depending on the field strength near their roots.

  15. Synthesis, Structural Characterization, and Antitumor Activity of a Ca(II Coordination Polymer Based on 1,6-Naphthalenedisulfonate and 4,4′-Bipyridyl

    Directory of Open Access Journals (Sweden)

    Xishi Tai

    2013-08-01

    Full Text Available A novel Ca(II coordination polymer, [CaL(4,4′-bipyridyl(H2O4]n (L = 1,6-naphthalenedisulfonate, was synthesized by reaction of calcium perchlorate with 1,6-naphthalenedisulfonic acid disodium salt and 4,4′-bipyridyl in CH3CH2OH/H2O. It was characterized by elemental analysis, IR, molar conductivity and thermogravimetric analysis. X-ray crystallography reveals that the Ca(II coordination polymer belongs to the orthorhombic system, with space group P212121. The geometry of the Ca(II ion is a distorted CaNO6 pengonal bipyramid, arising from its coordination by four water molecules, one nitrogen atom of 4,4′-bipyridyl molecule, and two oxygen atoms from two L ligands. The complex molecules form a helical chain by self-assembly. The antitumor activity of 1,6-naphthalenedisulfonic acid disodium salt and the Ca(II coordination polymer against human hepatoma smmc-7721 cell line and human lung adenocarcinoma A549 cell line reveals that the Ca(II coordination polymer inhibits cell growth of human lung adenocarcinoma A549 cell line with IC50 value of 27 μg/mL, and is more resistive to human lung adenocarcinoma A549 cell line as compared to 1,6-naphthalenedisulfonic acid disodium salt.

  16. Inhibitory effects of KN-93, an inhibitor of Ca2+ calmodulin-dependent protein kinase II, on light-regulated root gravitropism in maize

    Science.gov (United States)

    Feldman, L. J.; Hidaka, H.

    1993-01-01

    Light is essential for root gravitropism in Zea mays L., cultivar Merit. It is hypothesized that calcium mediates this light-regulated response. KN-93, an inhibitor of calcium/calmodulin kinase II (CaMK II), inhibits light-regulated root gravitropism but does not affect light perception. We hypothesize that CaMK II, or a homologue, operates late in the light/gravity signal transduction chain. Here we provide evidence suggesting a possible physiological involvement of CaMK II in root gravitropism in plants.

  17. Structure of the CaMKIIdelta/calmodulin complex reveals the molecular mechanism of CaMKII kinase activation.

    Directory of Open Access Journals (Sweden)

    Peter Rellos

    2010-07-01

    Full Text Available Long-term potentiation (LTP, a long-lasting enhancement in communication between neurons, is considered to be the major cellular mechanism underlying learning and memory. LTP triggers high-frequency calcium pulses that result in the activation of Calcium/Calmodulin (CaM-dependent kinase II (CaMKII. CaMKII acts as a molecular switch because it remains active for a long time after the return to basal calcium levels, which is a unique property required for CaMKII function. Here we describe the crystal structure of the human CaMKIIdelta/Ca2+/CaM complex, structures of all four human CaMKII catalytic domains in their autoinhibited states, as well as structures of human CaMKII oligomerization domains in their tetradecameric and physiological dodecameric states. All four autoinhibited human CaMKIIs were monomeric in the determined crystal structures but associated weakly in solution. In the CaMKIIdelta/Ca2+/CaM complex, the inhibitory region adopted an extended conformation and interacted with an adjacent catalytic domain positioning T287 into the active site of the interacting protomer. Comparisons with autoinhibited CaMKII structures showed that binding of calmodulin leads to the rearrangement of residues in the active site to a conformation suitable for ATP binding and to the closure of the binding groove for the autoinhibitory helix by helix alphaD. The structural data, together with biophysical interaction studies, reveals the mechanism of CaMKII activation by calmodulin and explains many of the unique regulatory properties of these two essential signaling molecules.This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3-D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the Web plugin are available in Text S1.

  18. FAST INVERSION OF SOLAR Ca II SPECTRA

    International Nuclear Information System (INIS)

    Beck, C.; Choudhary, D. P.; Rezaei, R.; Louis, R. E.

    2015-01-01

    We present a fast (<<1 s per profile) inversion code for solar Ca II lines. The code uses an archive of spectra that are synthesized prior to the inversion under the assumption of local thermodynamic equilibrium (LTE). We show that it can be successfully applied to spectrograph data or more sparsely sampled spectra from two-dimensional spectrometers. From a comparison to a non-LTE inversion of the same set of spectra, we derive a first-order non-LTE correction to the temperature stratifications derived in the LTE approach. The correction factor is close to unity up to log τ ∼ –3 and increases to values of 2.5 and 4 at log τ = –6 in the quiet Sun and the umbra, respectively

  19. A Devil in the Details: Matrix-Dependent 40Ca42Ca++/42Ca+ and Its Effects on Estimates of the Initial 41Ca/40Ca in the Solar System

    Science.gov (United States)

    McKeegan, K. D.; Liu, M.-C.

    2015-07-01

    Ian Hutcheon established that the molecular ion interference 40Ca42Ca++/42Ca+ on 41K+ is strongly dependent on the mineral analyzed. Correction for this "matrix effect" led to a downward revision of the initial 41Ca/40Ca of the solar system.

  20. Investigation in vitro Effects of Rivastigmine and Galantamine Used to Treatment of Alzheimer's Disease on CA Isozymes I and II

    OpenAIRE

    DİLEK, Esra; ÇANKAYA, Murat; EZMECİ, Talat; SUNAR, Mukadder; ÇOBAN, T. Abdulkadir

    2017-01-01

    The carbonicanhydrases (CA, EC. 4.2.1.1) are an expanding family of zinc-containing enzymescatalyzing the reversible hydration of CO2 in a two-step reaction toyield HCO3-and H+. These enzymes playimportant roles in several physiological/pathological processes. The aim ofthis study is to evaluate in vitrothe effects of these drug active substances which use which use for treatmentof Alzheimer disease on CA I and II isoenzyme. CA I and II isoenzymes fromhuman blood have been purified using Seph...

  1. Hydrolysis of molten CaCl2-CaF2 with additions of CaO

    Directory of Open Access Journals (Sweden)

    Espen Olsen

    2017-10-01

    Full Text Available Calcium halide based molten salts have recently attracted interest for a number of applications such as direct reduction of oxides for metal production and as liquefying agent in cyclic sorption processes for CO2 by CaO from dilute flue gases (Ca-looping. A fundamental aspect of these melts is the possible hydrolysis reaction upon exposure to gaseous H2O forming corrosive and poisonous hydrogen halides. In this work experiments have been performed investigating the formation of HCl and HF from a molten salt consisting of a 13.8 wt% CaF2 in CaCl2 eutectic exposed to a flowing gas consisting of 10 vol% H2O in N2. Hydrolysis has been investigated as function of content of CaO and temperature. HCl and HF are shown to be formed at elevated temperatures; HCl forms to a substantially larger extent than HF. Addition of CaO has a marked, limiting effect on the hydrolysis. Thermodynamic modeling of the reaction indicates activity coefficients for CaO above unity in the system. For cyclic CO2-capture based on thermal swing, it is advisable to keep the temperature in the carbonation (absorption reactor well below 850 ℃ while maintaining a high CaO content if molten CaCl2 is employed. Similar conclusions can be drawn with regards to CaF2.

  2. 76 FR 22809 - Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2011-04-25

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2011-0196] RIN 1625-AA00 Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA AGENCY... Security Exercise; San Francisco Bay, San Francisco, CA. (a) Location. The limits of this safety zone...

  3. Preparation of 45Ca(HDEHP)n and (CaH1502)2 samples for liquid scintillation counting, compared to 45caCl2 results

    International Nuclear Information System (INIS)

    Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.

    1994-01-01

    A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs

  4. DETECTION OF CA II ABSORPTION BY A HIGH-VELOCITY CLOUD IN THE DIRECTION OF THE QUASAR PKS 0837-120

    NARCIS (Netherlands)

    ROBERTSON, JG; SCHWARZ, UJ; VANWOERDEN, H; MURRAY, JD; MORTON, DC; HULSBOSCH, ANM

    1991-01-01

    We present optical absorption spectroscopy of the Ca II K and H lines along the sight line to the quasar PKS 0837-120, which lies in the direction of a high-velocity cloud (HVC) detected in H I 21-cm emission at V(LSR) = + 105 km s-1. Our data show Ca II absorption due to the HVC as well as a lower

  5. The effect of Ca2+ ions and ionic strength on Mn(II) oxidation by spores of the marine Bacillus sp. SG-1

    Science.gov (United States)

    Toyoda, Kazuhiro; Tebo, Bradley M.

    2013-01-01

    Manganese(IV) oxides, believed to form primarily through microbial activities, are extremely important mineral phases in marine environments where they scavenge a variety of trace elements and thereby control their distributions. The presence of various ions common in seawater are known to influence Mn oxide mineralogy yet little is known about the effect of these ions on the kinetics of bacterial Mn(II) oxidation and Mn oxide formation. We examined factors affecting bacterial Mn(II) oxidation by spores of the marine Bacillus sp. strain SG-1 in natural and artificial seawater of varying ionic conditions. Ca2+ concentration dramatically affected Mn(II) oxidation, while Mg2+, Sr2+, K+, Na+ and NO3- ions had no effect. The rate of Mn(II) oxidation at 10 mM Ca2+ (seawater composition) was four or five times that without Ca2+. The relationship between Ca2+ content and oxidation rate demonstrates that the equilibrium constant is small (on the order of 0.1) and the binding coefficient is 0.5. The pH optimum for Mn(II) oxidation changed depending on the amount of Ca2+ present, suggesting that Ca2+ exerts a direct effect on the enzyme perhaps as a stabilizing bridge between polypeptide components. We also examined the effect of varying concentrations of NaCl or KNO3 (0-2000 mM) on the kinetics of Mn(II) oxidation in solutions containing 10 mM Ca2+. Mn(II) oxidation was unaffected by changes in ionic strength (I) below 0.2, but it was inhibited by increasing salt concentrations above this value. Our results suggest that the critical coagulation concentration is around 200 mM of salt (I = ca. 0.2), and that the ionic strength of seawater (I > 0.2) accelerates the precipitation of Mn oxides around the spores. Under these conditions, the aggregation of Mn oxides reduces the supply of dissolved O2 and/or Mn2+ and inhibits the Mn(II) → Mn(III) step controlling the enzymatic oxidation of Mn(II). Our results suggest that the hardness and ionic strength of the aquatic environment

  6. Synthesis, structural characterization and antitumor activity of a Ca(II) coordination polymer based on 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide ligands

    Energy Technology Data Exchange (ETDEWEB)

    Tai, Xi-Shi, E-mail: taixs@wfu.edu.cn [Weifang University, College of Chemistry and Chemical Engineering (China); Wang, Xin [Qinghai Normal University, Department of Chemistry (China)

    2017-03-15

    A new Ca(II) coordination polymer, ([CaL(H{sub 2}O){sub 4}] · (H{sub 2}O){sub 4}){sub n} (L = 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide) has been prepared by one-pot synthesis method. And it was characterized by elemental analysis, IR and thermal analysis. The result of X-ray single-crystal diffraction analysis shows that the Ca(II) complex molecules form one-dimensional chain structure by the bridging oxygen atoms. The anti-tumor activity of L ligand and the Ca(II) coordination polymer has also been studied.

  7. CaMKII in sinoatrial node physiology and dysfunction

    Directory of Open Access Journals (Sweden)

    Yuejin eWu

    2014-03-01

    Full Text Available The calcium and calmodulin dependent protein kinase II (CaMKII is present in sinoatrial node (SAN pacemaker cells and is required for physiological fight or flight SAN beating rate responses. Inhibition of CaMKII in SAN does not affect baseline heart rate, but reduces heart rate increases in response to physiological stress. CaMKII senses intracellular calcium (Ca2+ changes, oxidation status and hyperglycemia to phosphorylate substrates that regulate Ca2+-sensitive proteins, such as L-type Ca2+ channels, phospholamban (PLN, and cardiac ryanodine receptors (RyR2. All of these substrates are involved in the SAN pacemaking mechanism. Excessive CaMKII activity, as occurs under pathological conditions such as heart failure, ischemia and diabetes, can promote intracellular Ca2+ overload and reactive oxygen species (ROS production. Oxidation of CaMKII (ox-CaMKII locks CaMKII into a constitutively active configuration that contributes to SAN cell apoptosis and fibrosis. This ox-CaMKII-mediated loss of functional SAN cells contributes to sinoatrial node dysfunction (SND and sudden death. Thus, CaMKII has emerged as a central regulator of physiological SAN responses and a key determinant of SND.

  8. Value of Combined Detection of Serum CEA, CA72-4, CA19-9, CA15-3 and CA12-5 in the Diagnosis of Gastric Cancer.

    Science.gov (United States)

    Chen, Changguo; Chen, Qiuyuan; Zhao, Qiangyuan; Liu, Min; Guo, Jianwei

    2017-05-01

    To examine whether the combined detection of serum tumor markers (CEA, CA72-4, CA19-9, CA15-3 and CA12-5) improves the sensitivity and accuracy in the diagnosis of gastric cancer (GC). An automatic chemiluminescence immune analyzer with matched kits was used to determine the levels of serum CEA, CA72-4, CA19-9, CA15-3, and CA12-5 in 87 patients with gastric cancer (GC group), 60 patients with gastric benign diseases (GBD group) who were hospitalized during the same period, and 40 healthy subjects undergoing a physical examination. The values of these 5 tumor markers in the diagnosis of gastric cancer were analyzed. The levels of serum CEA, CA72-4, CA19-9, and CA12-5 were higher in the GC group than in the GBD group and healthy subjects, and these differences were significant ( P 0.05). The combined detection of CEA, CA72-4, CA19-9, and CA12-5 had a higher diagnostic value for gastric cancer than did single detection, and the positive detection rate of the combined detection of the four tumor markers was 60.9%. The diagnostic power when using the combined detection of CA72-4, CEA, CA19-9, and CA12-5 was the best. The combined detection of serum CA72-4, CEA, CA19-9 and CA12-5 increases the sensitivity and accuracy in the diagnosis of GC and can thus be considered an important tool for early diagnosis. © 2017 by the Association of Clinical Scientists, Inc.

  9. Single-channel L-type Ca2+ currents in chicken embryo semicircular canal type I and type II hair cells.

    Science.gov (United States)

    Zampini, Valeria; Valli, Paolo; Zucca, Giampiero; Masetto, Sergio

    2006-08-01

    Few data are available concerning single Ca channel properties in inner ear hair cells and particularly none in vestibular type I hair cells. By using the cell-attached configuration of the patch-clamp technique in combination with the semicircular canal crista slice preparation, we determined the elementary properties of voltage-dependent Ca channels in chicken embryo type I and type II hair cells. The pipette solutions included Bay K 8644. With 70 mM Ba(2+) in the patch pipette, Ca channel activity appeared as very brief openings at -60 mV. Ca channel properties were found to be similar in type I and type II hair cells; therefore data were pooled. The mean inward current amplitude was -1.3 +/- 0.1 (SD) pA at - 30 mV (n = 16). The average slope conductance was 21 pS (n = 20). With 5 mM Ba(2+) in the patch pipette, very brief openings were already detectable at -80 mV. The mean inward current amplitude was -0.7 +/- 0.2 pA at -40 mV (n = 9). The average slope conductance was 11 pS (n = 9). The mean open time and the open probability increased significantly with depolarization. Ca channel activity was still present and unaffected when omega-agatoxin IVA (2 microM) and omega-conotoxin GVIA (3.2 microM) were added to the pipette solution. Our results show that types I and II hair cells express L-type Ca channels with similar properties. Moreover, they suggest that in vivo Ca(2+) influx might occur at membrane voltages more negative than -60 mV.

  10. Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.

    Science.gov (United States)

    Kim, Eun Young; Rumpf, Christine H; Van Petegem, Filip; Arant, Ryan J; Findeisen, Felix; Cooley, Elizabeth S; Isacoff, Ehud Y; Minor, Daniel L

    2010-12-01

    Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site.

  11. The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

    Science.gov (United States)

    González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

    2014-01-01

    An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p calcareum Ca was greater (p calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly absorbed before the duodenum, but Ca from L. calcareum Ca is mostly absorbed in the jejunum and ileum.

  12. βCaMKII plays a nonenzymatic role in hippocampal synaptic plasticity and learning by targeting αCaMKII to synapses.

    Science.gov (United States)

    Borgesius, Nils Z; van Woerden, Geeske M; Buitendijk, Gabrielle H S; Keijzer, Nanda; Jaarsma, Dick; Hoogenraad, Casper C; Elgersma, Ype

    2011-07-13

    The calcium/calmodulin-dependent kinase type II (CaMKII) holoenzyme of the forebrain predominantly consists of heteromeric complexes of the αCaMKII and βCaMKII isoforms. Yet, in contrast to αCaMKII, the role of βCaMKII in hippocampal synaptic plasticity and learning has not been investigated. Here, we compare two targeted Camk2b mouse mutants to study the role of βCaMKII in hippocampal function. Using a Camk2b(-/-) mutant, in which βCaMKII is absent, we show that both hippocampal-dependent learning and Schaffer collateral-CA1 long-term potentiation (LTP) are highly dependent upon the presence of βCaMKII. We further show that βCaMKII is required for proper targeting of αCaMKII to the synapse, indicating that βCaMKII regulates the distribution of αCaMKII between the synaptic pool and the adjacent dendritic shaft. In contrast, localization of αCaMKII, hippocampal synaptic plasticity and learning were unaffected in the Camk2b(A303R) mutant, in which the calcium/calmodulin-dependent activation of βCaMKII is prevented, while the F-actin binding and bundling property is preserved. This indicates that the calcium/calmodulin-dependent kinase activity of βCaMKII is fully dispensable for hippocampal learning, LTP, and targeting of αCaMKII, but implies a critical role for the F-actin binding and bundling properties of βCaMKII in synaptic function. Together, our data provide compelling support for a model of CaMKII function in which αCaMKII and βCaMKII act in concert, but with distinct functions, to regulate hippocampal synaptic plasticity and learning.

  13. Ca(2+) currents and voltage responses in Type I and Type II hair cells of the chick embryo semicircular canal.

    Science.gov (United States)

    Masetto, Sergio; Zampini, Valeria; Zucca, Giampiero; Valli, Paolo

    2005-11-01

    Type I and Type II hair cells, and Type II hair cells located in different zones of the semicircular canal crista, express different patterns of voltage-dependent K channels, each one specifically shaping the hair cell receptor potential. We report here that, close to hatching, chicken embryo semicircular canal Type I and Type II hair cells express a similar voltage-dependent L-type calcium current (I(Ca)), whose main features are: activation above -60 mV, fast activation kinetics, and scarce inactivation. I(Ca) should be already active at rest in Zone 1 Type II hair cells, whose resting membrane potential was on average slightly less negative than -60 mV. Conversely, I(Ca) would not be active at rest in Type II hair cells from Zone 2 and 3, nor in Type I hair cells, since their resting membrane potential was significantly more negative than -60 mV. However, even small depolarising currents would activate I(Ca) steadily in Zone 2 and 3 Type II hair cells, but not in Type I hair cells because of the robust repolarising action of their specific array of K(+) currents. The implications of the present findings in the afferent discharge are discussed.

  14. Ca2+/cation antiporters (CaCA: Identification, characterization and expression profiling in bread wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Mehak Taneja

    2016-11-01

    Full Text Available The Ca2+/cation antiporters (CaCA superfamily proteins play vital function in Ca2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat. Herein, we identified thirty four TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B and D subgenome and homeologous chromosome (HC, except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about ten transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections and abiotic stresses (heat, drought, salt suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However the role of individual gene needs to be established. The present study unfolded the opportunity

  15. Ca2+/Cation Antiporters (CaCA): Identification, Characterization and Expression Profiling in Bread Wheat (Triticum aestivum L.).

    Science.gov (United States)

    Taneja, Mehak; Tyagi, Shivi; Sharma, Shailesh; Upadhyay, Santosh Kumar

    2016-01-01

    The Ca 2+ /cation antiporters (CaCA) superfamily proteins play vital function in Ca 2+ ion homeostasis, which is an important event during development and defense response. Molecular characterization of these proteins has been performed in certain plants, but they are still not characterized in Triticum aestivum (bread wheat). Herein, we identified 34 TaCaCA superfamily proteins, which were classified into TaCAX, TaCCX, TaNCL, and TaMHX protein families based on their structural organization and evolutionary relation with earlier reported proteins. Since the T. aestivum comprises an allohexaploid genome, TaCaCA genes were derived from each A, B, and D subgenome and homeologous chromosome (HC), except chromosome-group 1. Majority of genes were derived from more than one HCs in each family that were considered as homeologous genes (HGs) due to their high similarity with each other. These HGs showed comparable gene and protein structures in terms of exon/intron organization and domain architecture. Majority of TaCaCA proteins comprised two Na_Ca_ex domains. However, TaNCLs consisted of an additional EF-hand domain with calcium binding motifs. Each TaCaCA protein family consisted of about 10 transmembrane and two α-repeat regions with specifically conserved signature motifs except TaNCL, which had single α-repeat. Variable expression of most of the TaCaCA genes during various developmental stages suggested their specified role in development. However, constitutively high expression of a few genes like TaCAX1-A and TaNCL1-B indicated their role throughout the plant growth and development. The modulated expression of certain genes during biotic (fungal infections) and abiotic stresses (heat, drought, salt) suggested their role in stress response. Majority of TaCCX and TaNCL family genes were found highly affected during various abiotic stresses. However, the role of individual gene needs to be established. The present study unfolded the opportunity for detail

  16. Relative cytotoxicity of complexes of platinum(II and palladium(II against pure cell culture Paramecium caudatum and human cell lines A431 and HaCaT

    Directory of Open Access Journals (Sweden)

    Aleksei Vladimirovich Eremin

    2018-04-01

    Full Text Available The results of cytotoxicity cisplatin-like complexes of platinum(II and palladium(II are presented. The cytotoxicity was researched by method of  biotesting with Paramecium caudatum and by MTT-assay with human cells: epidermoid carcimoma A431 and minimal transformed aneuploid keratinocytes HaCaT. Cytotoxicity of complexes toward protists is high, however, comparatively HaCaT are more sensitive than A431. Furthemore, cytotoxicity of palladium(II complexes is higher than the analogues with platinum(II.

  17. The Ca II resonance lines in M dwarf stars without H-alpha emission

    Energy Technology Data Exchange (ETDEWEB)

    Giampapa, M.S.; Cram, L.E.; Wild, W.J. (National Solar Observatory, Tucson, AZ (USA) Sydney Univ. (Australia) Arizona Univ., Tucson (USA))

    1989-10-01

    Spectra of the Ca II H and K lines in a sample of 31 M dwarf stars without H-alpha emission are used to calculate chromospheric K line radiative losses, F(k), and to study the joint response of Ca II K and H-alpha to chromospheric heating in dwarf M stars. It is suggested that the poor correlation found in the equivalent width - log F(K) diagram may be due either to radial segregation of the H-alpha and K line forming regions or to lateral inhomogeneities in the chromospheres. The results confirm the existence of dM stars with weak H-alpha absorption and K line emission only slightly weaker than that of the dMe stars, and show that dM stars with weak H-alpha but kinematics and metallicities representative of the young disk population belong to a class characterized by a comparatively high degree of chromospheric activity. 32 refs.

  18. CaMKII in the Cardiovascular System: Sensing Redox States

    Science.gov (United States)

    Erickson, Jeffrey R.; He, B. Julie; Grumbach, Isabella M.; Anderson, Mark E

    2013-01-01

    The multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is now recognized to play a central role in pathological events in the cardiovascular system. CaMKII has diverse downstream targets that promote vascular disease, heart failure and arrhythmias, so improved understanding of CaMKII signaling has the potential to lead to new therapies for cardiovascular disease. CaMKII is a multimeric serine-threonine kinase that is initially activated by binding calcified calmodulin (Ca2+/CaM). Under conditions of sustained exposure to elevated Ca2+/CaM CaMKII transitions into a Ca2+/CaM-autonomous enzyme by two distinct but parallel processes. Autophosphorylation of threonine 287 in the CaMKII regulatory domain ‘traps’ CaMKII into an open configuration even after Ca2+/CaM unbinding. More recently, our group identified a pair of methionines (281/282) in the CaMKII regulatory domain that undergo a partially reversible oxidation which, like autophosphorylation, prevents CaMKII from inactivating after Ca2+/CaM unbinding. Here we review roles of CaMKII in cardiovascular disease with an eye to understanding how CaMKII may act as a transduction signal to connect pro-oxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of cardiovascular disease. PMID:21742790

  19. Solar center-limb variation of the Ca II K line and the Wilson-Bappu effect

    International Nuclear Information System (INIS)

    Engvold, O.; Marstad, N.C.

    1983-01-01

    New observations of the quiet Sun Ca II K line center-to-limb (C-L) have been made. The separation of the K 2 intensity peaks, the K 1 intensity minima and the intermediate width W 0 (the Wilson-Bappu width) are presented. It is shown that the C-L variation of all three parameters can be accounted for as a dependence on chromospheric column mass. The corresponding Ca II K line with parameters of 41 late type stars are also shown to vary in accordance with the inferred chromospheric column mass of the stars. The solar C-L and the stellar variation of the widths ΔK 1 and W 0 are found to have nearly indentical factors of proportionality with respect to log (column mass)

  20. The role of Ca2+/calmodulin-dependent protein kinase II and calcineurin in TNF-α-induced myocardial hypertrophy

    International Nuclear Information System (INIS)

    Wang, Gui-Jun; Wang, Hong-Xin; Yao, Yu-Sheng; Guo, Lian-Yi; Liu, Pei

    2012-01-01

    We investigated whether Ca 2+ /calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) are involved in myocardial hypertrophy induced by tumor necrosis factor α (TNF-α). The cardiomyocytes of neonatal Wistar rats (1-2 days old) were cultured and stimulated by TNF-α (100 µg/L), and Ca 2+ signal transduction was blocked by several antagonists, including BAPTA (4 µM), KN-93 (0.2 µM) and cyclosporin A (CsA, 0.2 µM). Protein content, protein synthesis, cardiomyocyte volumes, [Ca 2+ ] i transients, CaMKIIδ B and CaN were evaluated by the Lowry method, [ 3 H]-leucine incorporation, a computerized image analysis system, a Till imaging system, and Western blot analysis, respectively. TNF-α induced a significant increase in protein content in a dose-dependent manner from 10 µg/L (53.56 µg protein/well) to 100 µg/L (72.18 µg protein/well), and in a time-dependent manner from 12 h (37.42 µg protein/well) to 72 h (42.81 µg protein/well). TNF-α (100 µg/L) significantly increased the amplitude of spontaneous [Ca 2+ ] i transients, the total protein content, cell size, and [ 3 H]-leucine incorporation in cultured cardiomyocytes, which was abolished by 4 µM BAPTA, an intracellular Ca 2+ chelator. The increases in protein content, cell size and [ 3 H]-leucine incorporation were abolished by 0.2 µM KN-93 or 0.2 µM CsA. TNF-α increased the expression of CaMKIIδ B by 35.21% and that of CaN by 22.22% compared to control. These effects were abolished by 4 µM BAPTA, which itself had no effect. These results suggest that TNF-α induces increases in [Ca 2+ ] i , CaMKIIδ B and CaN and promotes cardiac hypertrophy. Therefore, we hypothesize that the Ca 2+ /CaMKII- and CaN-dependent signaling pathways are involved in myocardial hypertrophy induced by TNF-α

  1. A Butterfly Diagram and Carrington Maps for Century-long CA II K Spectroheliograms from The Kodaikanal Observatory

    Science.gov (United States)

    Chatterjee, Subhamoy; Banerjee, Dipankar; Ravindra, B.

    2016-08-01

    The century-long (1907-2007) Ca II K spectroheliograms from the Kodaikanal Solar Observatory (KSO) are calibrated, processed, and analyzed to follow the evolution of the bright on-disc structures called plages, possible representatives of magnetic activity on the Sun. This is the longest data set studied in Ca II K to date, covering about 9.5 cycles of 11 yr periods. Plages are segmented with area ≥slant 1 {{arcmin}}2 using global thresholds for individual full disc images and subsequent application of a morphological closing operation. The plage index is calculated and is seen to have a close positive correlation with the fractional disc area covered by plages. The newly generated plage area cycle (from KSO) was compared with the same from the Mount Wilson Observatory (correlation 95.6%) for the overlapping years, I.e., 1915-2000. This study illustrates the time-latitude distribution of plage centroids by rendering a butterfly diagram (as observed for sunspots). The 3D visualization of the diagram shows one-to-one mapping between plage location, time, and area. This work further delineates the positional correlation between magnetic patches and plage regions through the comparison of synoptic maps derived from both KSO Ca II K images and space-based full disc line-of-sight magnetograms. Regular synoptic magnetograms from ground-based observatories are available only after 1970s. Thus the long term Ca II K data from KSO can be used as a proxy for estimating magnetic activity locations and their strengths at earlier times.

  2. Control of ciliary motility by Ca2+: Integration of Ca2+-dependent functions and targets for Ca2+ action

    International Nuclear Information System (INIS)

    Evans, T.C.

    1988-01-01

    To identify functions that regulate Ca 2+ -induced ciliary reversal in Paramecium, mutants defective in terminating depolarization-induced backward swimming were selected. Six independent recessive mutations (k-shy) comprising two complementation groups, k-shyA and k-shyB, were identified. All mutants exhibited prolonged backward swimming in depolarizing solutions. Voltage clamp studies revealed that mutant Ca 2+ current amplitudes were reduced, but could be restored to wild type levels by EGTA injection. The recovery of the mutant Ca 2+ current from Ca 2+ -dependent inactivation, and the decay of the Ca 2+ -dependent K + and Ca 2+ -dependent Na + currents after depolarization were slow in k-shy compared to wild type. To identify protein targets of Ca 2+ action, ciliary proteins that interact with calmodulin (CaM) were characterized. With a 125 I-CaM blot assay, several CaM-binding proteins were identified including axonemal, soluble, and membrane-bound polypeptides. Competitive displacement studies with unlabeled Paramecium CaM, bovine CaM, and troponinC suggested that both protein types bind CaM with high affinity and specificity. To examine the presence of CaM-binding sites in intact axonemes, a filtration binding assay was developed

  3. An inhibitory effect of extracellular Ca2+ on Ca2+-dependent exocytosis.

    Directory of Open Access Journals (Sweden)

    Wei Xiong

    Full Text Available AIM: Neurotransmitter release is elicited by an elevation of intracellular Ca(2+ concentration ([Ca(2+](i. The action potential triggers Ca(2+ influx through Ca(2+ channels which causes local changes of [Ca(2+](i for vesicle release. However, any direct role of extracellular Ca(2+ (besides Ca(2+ influx on Ca(2+-dependent exocytosis remains elusive. Here we set out to investigate this possibility on rat dorsal root ganglion (DRG neurons and chromaffin cells, widely used models for studying vesicle exocytosis. RESULTS: Using photolysis of caged Ca(2+ and caffeine-induced release of stored Ca(2+, we found that extracellular Ca(2+ inhibited exocytosis following moderate [Ca(2+](i rises (2-3 µM. The IC(50 for extracellular Ca(2+ inhibition of exocytosis (ECIE was 1.38 mM and a physiological reduction (∼30% of extracellular Ca(2+ concentration ([Ca(2+](o significantly increased the evoked exocytosis. At the single vesicle level, quantal size and release frequency were also altered by physiological [Ca(2+](o. The calcimimetics Mg(2+, Cd(2+, G418, and neomycin all inhibited exocytosis. The extracellular Ca(2+-sensing receptor (CaSR was not involved because specific drugs and knockdown of CaSR in DRG neurons did not affect ECIE. CONCLUSION/SIGNIFICANCE: As an extension of the classic Ca(2+ hypothesis of synaptic release, physiological levels of extracellular Ca(2+ play dual roles in evoked exocytosis by providing a source of Ca(2+ influx, and by directly regulating quantal size and release probability in neuronal cells.

  4. Chromospheric Ca II H and K and H-alpha emission in single and binary stars of spectral types F6-M2

    International Nuclear Information System (INIS)

    Strassmeier, K.G.; Fekel, F.C.; Bopp, B.W.; Dempsey, R.C.; Henry, G.W.

    1990-01-01

    New observations of the Ca II H and K and H-epsilon region and/or the Balmer H-alpha line are presented for 100 mostly very active stars but also for weak or inactive stars with suspected activity. Correlations between chromospheric activity at Ca II H and K and H-alpha and effective surface temperature and rotation are identified, and several new stars with chromospheric Ca II H and K emission are discovered. No single activity-rotation relation can be derived for all luminosity classes, and there is clear evidence that evolved stars are generally more active than main-sequence stars of the same rotation period. Binary within the evolved stars appears to play no role, while main-sequence binary stars show generally higher levels of activity than their single counterparts. Chromospheric emission in the Ca II H and K lines depends on surface temperature in that flux declines with cooler temperature. 63 refs

  5. Reduction of SR Ca2+ leak and arrhythmogenic cellular correlates by SMP-114, a novel CaMKII inhibitor with oral bioavailability.

    Science.gov (United States)

    Neef, Stefan; Mann, Christian; Zwenger, Anne; Dybkova, Nataliya; Maier, Lars S

    2017-07-01

    Sarcoplasmic reticulum (SR) Ca 2+ leak induced by Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) is centrally involved in atrial and ventricular arrhythmogenesis as well as heart failure remodeling. Consequently, treating SR Ca 2+ leak has been proposed as a novel therapeutic paradigm, but compounds for use in humans are lacking. SMP-114 ("Rimacalib") is a novel, orally available CaMKII inhibitor developed for human use that has already entered clinical phase II trials to treat rheumatoid arthritis. We speculated that SMP-114 might also be useful to treat cardiac SR Ca 2+ leak. SMP-114 significantly reduces SR Ca 2+ leak (as assessed by Ca 2+ sparks) in human atrial (0.72 ± 0.33 sparks/100 µm/s vs. control 3.02 ± 0.91 sparks/100 µm/s) and failing left ventricular (0.78 ± 0.23 vs. 1.69 ± 0.27 sparks/100 µm/s) as well as in murine ventricular cardiomyocytes (0.30 ± 0.07 vs. 1.50 ± 0.28 sparks/100 µm/s). Associated with lower SR Ca 2+ leak, we found that SMP-114 suppressed the occurrence of spontaneous arrhythmogenic spontaneous Ca 2+ release (0.356 ± 0.109 vs. 0.927 ± 0.216 events per 30 s stimulation cessation). In consequence, post-rest potentiation of Ca 2+ -transient amplitude (measured using Fura-2) during the 30 s pause was improved by SMP-114 (52 ± 5 vs. 37 ± 4%). Noteworthy, SMP-114 has these beneficial effects without negatively impairing global excitation-contraction coupling: neither systolic Ca 2+ release nor single cell contractility was compromised, and also SR Ca 2+ reuptake, in line with resulting cardiomyocyte relaxation, was not impaired by SMP-114 in our assays. SMP-114 demonstrated potential to treat SR Ca 2+ leak and consequently proarrhythmogenic events in rodent as well as in human atrial cardiomyocytes and cardiomyocytes from patients with heart failure. Further research is necessary towards clinical use in cardiac disease.

  6. Distribución Espacial de Ancho Equivalente del Triplete del CaII a partir de Imágenes GMOS

    Science.gov (United States)

    Díaz, R. J.; Mast, D.

    Using Gemini+GMOS imagery obtained through the filters i, z and CaT, we developed a technique for estimating the value of the Ca II triplet (CaT) equivalent width (EW). The map generated through arithmetic operations with the near infrared images was calibrated with long slit spectra obtained with REOSC spectrograph at CASLEO. We apply this technique to the study of M 83 central region and present the preliminary results on the spatial distribution of the EW(CaT) within an area of 40 per 40 square arcsec around the double nucleus of M 83, with a spatial resolution of 0.8 arcsec. FULL TEXT IN SPANISH.

  7. CaMKII determines mitochondrial stress responses in heart

    Science.gov (United States)

    Joiner, Mei-ling A.; Koval, Olha M.; Jingdong, Li; He, B. Julie; Allamargot, Chantal; Gao, Zhan; Luczak, Elizabeth D.; Hall, Duane D.; Fink, Brian D.; Chen, Biyi; Yang, Jinying; Moore, Steven A.; Scholz, Thomas D.; Strack, Stefan; Mohler, Peter J.; Sivitz, William I.; Song, Long-Sheng; Anderson, Mark E.

    2012-01-01

    Myocardial cell death is initiated by excessive mitochondrial Ca2+ entry, causing Ca2+ overload, mitochondrial permeability transition pore (mPTP) opening and dissipation of the mitochondrial inner membrane potential (ΔΨm)1,2. However, the signaling pathways that control mitochondrial Ca2+ entry through the inner membrane mitochondrial Ca2+ uniporter (MCU)3–5 are not known. The multifunctional Ca2+ and calmodulin-dependent protein kinase II (CaMKII) is activated in ischemia reperfusion (I/R), myocardial infarction (MI) and neurohumoral injury, common causes of myocardial death and heart failure, suggesting CaMKII could couple disease stress to mitochondrial injury. Here we show that CaMKII promotes mPTP opening and myocardial death by increasing MCU current (IMCU). Mitochondrial-targeted CaMKII inhibitory protein or cyclosporin A (CsA), an mPTP antagonist with clinical efficacy in I/R injury6, equivalently prevent mPTP opening, ΔΨm deterioration and diminish mitochondrial disruption and programmed cell death in response to I/R injury. Mice with myocardial and mitochondrial-targeted CaMKII inhibition are resistant to I/R injury, MI and neurohumoral injury, suggesting pathological actions of CaMKII are substantially mediated by increasing IMCU. Our findings identify CaMKII activity as a central mechanism for mitochondrial Ca2+ entry and suggest mitochondrial-targeted CaMKII inhibition could prevent or reduce myocardial death and heart failure dysfunction in response to common experimental forms of pathophysiological stress. PMID:23051746

  8. Reduced endogenous Ca2+ buffering speeds active zone Ca2+ signaling.

    Science.gov (United States)

    Delvendahl, Igor; Jablonski, Lukasz; Baade, Carolin; Matveev, Victor; Neher, Erwin; Hallermann, Stefan

    2015-06-09

    Fast synchronous neurotransmitter release at the presynaptic active zone is triggered by local Ca(2+) signals, which are confined in their spatiotemporal extent by endogenous Ca(2+) buffers. However, it remains elusive how rapid and reliable Ca(2+) signaling can be sustained during repetitive release. Here, we established quantitative two-photon Ca(2+) imaging in cerebellar mossy fiber boutons, which fire at exceptionally high rates. We show that endogenous fixed buffers have a surprisingly low Ca(2+)-binding ratio (∼ 15) and low affinity, whereas mobile buffers have high affinity. Experimentally constrained modeling revealed that the low endogenous buffering promotes fast clearance of Ca(2+) from the active zone during repetitive firing. Measuring Ca(2+) signals at different distances from active zones with ultra-high-resolution confirmed our model predictions. Our results lead to the concept that reduced Ca(2+) buffering enables fast active zone Ca(2+) signaling, suggesting that the strength of endogenous Ca(2+) buffering limits the rate of synchronous synaptic transmission.

  9. Photoemission study of Ca-intercalated graphite superconductor CaC6

    International Nuclear Information System (INIS)

    Okazaki, Hiroyuki; Yoshida, Rikiya; Iwai, Keisuke; Noami, Kengo; Muro, Takayuki; Nakamura, Tetsuya; Wakita, Takanori; Muraoka, Yuji; Hirai, Masaaki; Tomioka, Fumiaki; Takano, Yoshihiko; Takenaka, Asami; Toyoda, Masahiro; Oguchi, Tamio; Yokoya, Takayoshi

    2010-01-01

    In this work, we have performed resonant photoemission studies of Ca-intercalated graphite superconductor CaC 6 . Using photon energy of the Ca 2p-3d threshold, the photoemission intensity of the peak at Fermi energy (E F ) is resonantly enhanced. This result provides spectroscopic evidence for the existence of Ca 3d states at E F , and strongly supports that Ca 3d state plays a crucial role for the superconductivity of this material with relatively high T c .

  10. Solubility of calcium in CaO-CaCl2

    International Nuclear Information System (INIS)

    Perry, G.S.; Shaw, S.J.

    1991-06-01

    The Direct Oxide Reduction (DOR) process is well established as a process to produce plutonium metal from plutonium dioxide by reaction with calcium. Calcium chloride is added to dissolve the calcium oxide produced, allowing the metal to coalesce into a button. Since calcium metal melts at 840 0 C and DOR can take place successfully below this temperature, it is likely calcium dissolved in calcium chloride reacts with the plutonium dioxide. The solubility of calcium in calcium chloride is reasonably well established but the effect of the CaO formed during the DOR process on the solubility of calcium has not been previously determined. For this reason the solubility of calcium in CaCl 2 -CaO melts at 800 o C has been studied. The solubility decreases from 2.7 mol % in CaCl 2 to 0.4 mol % in 9 mol % CaO-CaCl 2 . (author)

  11. Astragalus Granule Prevents Ca2+ Current Remodeling in Heart Failure by the Downregulation of CaMKII

    Directory of Open Access Journals (Sweden)

    Sinai Li

    2017-01-01

    Full Text Available Background. Astragalus was broadly used for treating heart failure (HF and arrhythmias in East Asia for thousands of years. Astragalus granule (AG, extracted from Astragalus, shows beneficial effect on the treatment of HF in clinical research. We hypothesized that administration of AG prevents the remodeling of L-type Ca2+ current (ICa-L in HF mice by the downregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII. Methods. HF mice were induced by thoracic aortic constriction (TAC. After 4 weeks of AG treatment, cardiac function and QT interval were evaluated. Single cardiac ventricular myocyte was then isolated and whole-cell patch clamp was used to record action potential (AP and ICa-L. The expressions of L-type calcium channel alpha 1C subunit (Cav1.2, CaMKII, and phosphorylated protein kinase A (p-PKA were examined by western blot. Results. The failing heart manifested distinct electrical remodeling including prolonged repolarization time and altered ICa-L kinetics. AG treatment attenuated this electrical remodeling, supported by AG-related shortened repolarization time, decreased peak ICa-L, accelerated ICa-L inactivation, and positive frequency-dependent ICa-L facilitation. In addition, AG treatment suppressed the overexpression of CaMKII, but not p-PKA, in the failing heart. Conclusion. AG treatment protected the failing heart against electrical remodeling and ICa-L remodeling by downregulating CaMKII.

  12. Preparation of 45Ca(HDEHP)n and (CaH{sub 1}50{sub 2})2 samples for liquid scintillation counting, compared to 45caCl{sub 2} results; Preparacion de Ca (HDEHP)n y (C{sub 8}H{sub 1}50{sub 2})2 marcados con 45Ca y estudio comparativo con 4 5ca Cl2 en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.

    1994-07-01

    A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs.

  13. Mechanochemical synthesis and intercalation of Ca(II)Fe(III)-layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Ferencz, Zs.; Szabados, M.; Varga, G.; Csendes, Z. [Department of Organic Chemistry, University of Szeged, Dóm tér 8, Szeged H-6720 (Hungary); Materials and Solution Structure Research Group, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720 (Hungary); Kukovecz, Á. [Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720 (Hungary); MTA-SZTE “Lendület” Porous Nanocomposites Research Group, Rerrich Béla tér 1, Szeged H-6720 (Hungary); Kónya, Z. [Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720 (Hungary); MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, Rerrich Béla tér 1, Szeged H-6720 (Hungary); Carlson, S. [MAX IV Laboratory, Ole Römers väg 1, Lund SE-223 63 (Sweden); Sipos, P. [Materials and Solution Structure Research Group, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720 (Hungary); Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged H-6720 (Hungary); and others

    2016-01-15

    A mechanochemical method (grinding the components without added water – dry grinding, followed by further grinding in the presence of minute amount of water or NaOH solution – wet grinding) was used in this work for the preparation and intercalation of CaFe-layered double hydroxides (LDHs). Both the pristine LDHs and the amino acid anion (cystinate and tyrosinate) intercalated varieties were prepared by the two-step grinding procedure in a mixer mill. By systematically changing the conditions of the preparation method, a set of parameters could be determined, which led to the formation of close to phase-pure LDH. The optimisation procedure was also applied for the intercalation processes of the amino acid anions. The resulting materials were structurally characterised by a range of methods (X-ray diffractometry, scanning electron microscopy, energy dispersive analysis, thermogravimetry, X-ray absorption and infra-red spectroscopies). It was proven that this simple mechanochemical procedure was able to produce complex organic–inorganic nanocomposites: LDHs intercalated with amino acid anions. - Graphical abstract: Amino acid anion-Ca(II)Fe(III)-LDHs were successfully prepared by a two-step milling procedure. - Highlights: • Synthesis of pristine and amino acid intercalated CaFe-LDHs by two-step milling. • Identifying the optimum synthesis and intercalation parameters. • Characterisation of the samples with a range of instrumental methods.

  14. Efficient simultaneous removal of U(VI) and Cu(II) from aqueous solution using core-shell nZVI@SA/CMC-Ca beads

    International Nuclear Information System (INIS)

    Shuhong Hu; Xiaoyan Lin; Wenhui Zhao; Ministry of Education, Sichuan; Xuegang Luo

    2018-01-01

    Core-shell nanoscale zero-valent iron@alginate/carboxymethyl cellulose sodium composite loaded with calcium (nZVI@SA/CMC-Ca) beads were synthesized in this study using coaxial electronic injection method. The adsorbent structure was characterized via FT-IR, SEM, EDX and XPS. The adsorption behavior of U(VI) and Cu(II) on core-shell nZVI@SA/CMC-Ca beads was studied under various experimental parameters like pH, contact time and temperature. The isotherm and the kinetic data, pertaining to the adsorption of U(VI) and Cu(II) by core-shell nZVI@SA/CMC-Ca beads obeyed both the Langmuir and Freundlich isotherms model and the pseudo-second-order kinetics model, respectively. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption. The experiment of regeneration and reusability suggested core-shell nZVI@SA/CMC-Ca bead was a regenerated material. (author)

  15. Coping with Asymmetric Channel Losses in CSMA/CA

    DEFF Research Database (Denmark)

    Paramanathan, Achuthan; Roetter, Daniel Enrique Lucani; Fitzek, Frank

    2013-01-01

    Inspired by the discrepancy between past theoretical analysis and real measurements for high-load scenarios for intersession network coding, we pinpoint and analyze the source of this discrepancy in wireless networks implementing a CSMA/CA medium access scheme. Our analysis shows that CSMA/CA is ......) confirm the sensitivity of the CSMA/CA scheme in real implementations, and (ii) shows that our adaptive protocol provides a simple, yet potent mechanism to cope with asymmetric channel losses and ultimately to enhance end-to-end throughput in high-load scenarios....

  16. Study on the diagnostic value of determination of changes of serum CA125 and CA19-9 levels in patients with endometriosis

    International Nuclear Information System (INIS)

    Liu Aimin

    2008-01-01

    Objective: To explore the diagnostic value of determination of changes of serum CA125 and CA19-9 levels in patients with endometriosis. Methods: Serum CA125 and CA19-9 levels were determined with RIA in 45 patients with endometriosis and 40 controls. Results: Serum levels of CA125 and CA19-9 in patients with endometriosis (89.63 ± 30.16u/ml and 95.62±43.67u/ml respectively) were significantly higher than those (16.26±6.37u/ml and 20.26±8.25u/ml respectively) in controls (P<0. 001). Sensitivity of CA125 for diagnosis of endometriosis was 77.78% and that of CA19-9 was 62.22%, while the specificity was 92.50% and 90.00% respectively. If we only took the patients with both markers elevated as being diagnostically positive, the sensitivity would naturally be lower (57.78%) but the specificity would be 100%. Levels of the markers were significantly higher in stage III, IV patients than those in patients with stage I, II disease (P<0.01). Conclusion: Combined determination of serum CA125 and CA19-9 levels were of highly specific diagnostic value in patients with endometriosis. (authors)

  17. Atmospheric structure deduced from disturbed line profiles application to Ca II lines

    International Nuclear Information System (INIS)

    Mein, N.; Mein, P.; Malherbe, J.-M.; Dame, L.; Dumont, S.; CNRS, Laboratoire de Physique Stellaire et Planetaire, Verrieres-le-Buisson, France; College de France, Paris)

    1985-01-01

    A new method is described in order to derive physical quantities (temperature, pressure, radial velocities) from the observation of disturbed line profiles. A method of Fourier analysis is suggested with double profiles and a nonlinear expansion of the coefficient of the Fourier terms. An application to a sequence of H-Ca II lines is attempted. The method is a powerful tool allowing for the simultaneous determination of at least four physical quantities. 9 references

  18. Dynamics of the Solar Chromosphere. II. Ca II H2V and K2V Grains versus Internetwork Fields

    NARCIS (Netherlands)

    Lites, B.W.; Rutten, R.J.; Berger, T.E.

    1998-01-01

    We use the Advanced Stokes Polarimeter at the NSO/Sacramento Peak Vacuum Tower Telescope to search for spatio- temporal correlations between enhanced magnetic fields in the quiet solar internetwork photosphere and the occurrence of Ca II H2v grains in the overlying chromosphere.We address the

  19. Oxidized CaMKII causes cardiac sinus node dysfunction in mice

    Science.gov (United States)

    Swaminathan, Paari Dominic; Purohit, Anil; Soni, Siddarth; Voigt, Niels; Singh, Madhu V.; Glukhov, Alexey V.; Gao, Zhan; He, B. Julie; Luczak, Elizabeth D.; Joiner, Mei-ling A.; Kutschke, William; Yang, Jinying; Donahue, J. Kevin; Weiss, Robert M.; Grumbach, Isabella M.; Ogawa, Masahiro; Chen, Peng-Sheng; Efimov, Igor; Dobrev, Dobromir; Mohler, Peter J.; Hund, Thomas J.; Anderson, Mark E.

    2011-01-01

    Sinus node dysfunction (SND) is a major public health problem that is associated with sudden cardiac death and requires surgical implantation of artificial pacemakers. However, little is known about the molecular and cellular mechanisms that cause SND. Most SND occurs in the setting of heart failure and hypertension, conditions that are marked by elevated circulating angiotensin II (Ang II) and increased oxidant stress. Here, we show that oxidized calmodulin kinase II (ox-CaMKII) is a biomarker for SND in patients and dogs and a disease determinant in mice. In wild-type mice, Ang II infusion caused sinoatrial nodal (SAN) cell oxidation by activating NADPH oxidase, leading to increased ox-CaMKII, SAN cell apoptosis, and SND. p47–/– mice lacking functional NADPH oxidase and mice with myocardial or SAN-targeted CaMKII inhibition were highly resistant to SAN apoptosis and SND, suggesting that ox-CaMKII–triggered SAN cell death contributed to SND. We developed a computational model of the sinoatrial node that showed that a loss of SAN cells below a critical threshold caused SND by preventing normal impulse formation and propagation. These data provide novel molecular and mechanistic information to understand SND and suggest that targeted CaMKII inhibition may be useful for preventing SND in high-risk patients. PMID:21785215

  20. Preoperative serum levels of ca 72-4, cea, ca 19-9, and Alpha-fetoprotein in patients with gastric cancer Níveis séricos pré-operatórios de CA 72-4, CEA, CA 19-9 e Alfa-fetoproteína em pacientes com câncer gástrico

    Directory of Open Access Journals (Sweden)

    Rejane Mattar

    2002-06-01

    Full Text Available INTRODUCTION: The clinical importance of preoperative serum levels of CA 72-4, carcinoembryonic antigen (CEA, CA 19-9, and alpha-fetoprotein (AFP was prospectively evaluated in 44 patients with gastric cancer. METHOD: The serum tumor marker levels were determined by commercial radioimmunoassay kits. Positivity for CA 72-4 (>4 U/mL, CEA (>5 ng/mL, CA 19-9 (>37 U/mL, and AFP (>10 ng/mL were correlated according to the stage, histology, and lymph node metastasis. RESULTS AND DISCUSSION: CA 72-4 showed a higher positivity rate for gastric cancer (47.7% than CEA (25%, CA 19-9 (25%, and AFP (0%. The combination of CA 72-4 with CEA and CA 19-9 increased the sensitivity to 61.4%. The positivity rates of CA 72-4 in patients at stages I and II (initial disease and in patients at stages III and IV (advanced disease were 9% and 60.6%, respectively (P INTRODUÇÃO: A importância clínica dos níveis séricos pré-operatórios de CA 72-4, antígeno carcinoembrionário (CEA, CA 19-9 e alfa-fetoproteína (AFPfoi avaliada prospectivamente em 44 pacientes com câncer gástrico. MÉTODOS: Os marcadores tumorais foram quantificados com o emprego de kits comerciais de radioimunoensaio. A positividade dos marcadores, CA 72-4 (>4 U/ml, CEA (>5 ng/ml, CA 19-9 (>37 U/ml e AFP (>10 ng/ml, foi correlacionada com o estágio da doença, a histologia do tumor e comprometimento de linfonodo. RESULTADOS E DISCUSSÃO: O marcador CA 72-4 apresentou maior positividade para o câncer gástrico (47,7% que CEA (25%, CA 19-9 (25% e AFP (0%. A associação de CA 72-4, CEA e CA 19-9 aumentou a sensibilidade para 61,4%. A positividade do CA 72-4 nos pacientes com estágios I e II (Doença Inicial e nos pacientes com estágios III e IV (Doença Avançada foi de 9 e 60,6%, respectivamente (p<0,005. Não foi observada correlação entre os níveis séricos de CEA e CA 19-9 com o estágio do câncer gástrico. O CA 72-4 apresentou tendência de sugerir comprometimento de linfonodo, mas n

  1. Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

    Science.gov (United States)

    Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

    2016-01-01

    Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

  2. crdi.ca

    International Development Research Centre (IDRC) Digital Library (Canada)

    et des enfants d'Afrique. INITIATIVE CONCERTÉE. Innovation pour la santé des mères et des enfants d'Afrique. Centre de recherches pour le développement international. CP Box 8500 Ottawa ON Canada K1G 3H9. Téléphone : +1 613 236 6163 • Télécopieur : +1 613 657 7749 ismea@crdi.ca | www.crdi.ca/ismea crdi.ca.

  3. Asymmetries of the solar Ca II lines

    International Nuclear Information System (INIS)

    Heasley, J.N.

    1975-01-01

    A theoretical study of the influence of propagating acoustic pulses in the solar chromosphere upon the line profiles of the Ca II resonance and infrared triplet lines has been made. The major objective has been to explain the observed asymmetries seen in the cores of the H and K lines and to predict the temporal behavior of the infrared lines caused by passing acoustic or shock pulses. The velocities in the pulses, calculated from weak shock theory, have been included consistently in the non-LTE calculations. The results of the calculations show that these lines are very sensitive to perturbations in the background atmosphere caused by the pulses. Only minor changes in the line shapes result from including the velocities consistently in the line source function calculations. The qualitative changes in the line profiles vary markedly with the strength of the shock pulses. The observed differences in the K line profiles seen on the quiet Sun can be explained in terms of a spectrum of pulses with different wavelengths and initial amplitudes in the photosphere. (Auth.)

  4. Renovascular BK(Ca) channels are not activated in vivo under resting conditions and during agonist stimulation

    DEFF Research Database (Denmark)

    Magnusson, Linda; Sørensen, Charlotte Mehlin; Braunstein, Thomas Hartig

    2006-01-01

    We investigated the role of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels for the basal renal vascular tone in vivo. Furthermore, the possible buffering by BK(Ca) of the vasoconstriction elicited by angiotensin II (ANG II) or norepinephrine (NE) was investigated. The possible activation.......3 nmol/min) did not have any effect. Renal injection of ANG II (1-4 ng) or NE (10-40 ng) produced a transient decrease in RBF. These responses were not affected by preinfusion of TEA or IBT. Renal infusion of the BK(Ca) opener NS-1619 (90.0 nmol/min) did not affect basal RBF or the response to NE......, there is no indication for a major role for BK(Ca) channels in the control of basal renal tone in vivo. Furthermore, BK(Ca) channels do not have a buffering effect on the rat renal vascular responses to ANG II and NE. The fact that NS-1619 attenuates the ANG II response indicates that the renal vascular BK(Ca) channels...

  5. Rotation and kinematics of the premain-sequence stars in Taurus-Auriga with Ca II emission

    Science.gov (United States)

    Hartmann, Lee W.; Soderblom, David R.; Stauffer, John R.

    1987-01-01

    Radial velocities and v sin i values for the stars in the Taurus-Auriga region that were found to have strong Ca II H and K emission by Herbig, Vrba, and Rydgren 'HVR', (1986) are reported. Most of the velocities are determined to better than 2 km/s precision. The kinematic properties of the Ca II emission stars with strong Li are found to be indistinguishable from conventional T Tauris in Taurus-Auriga, contrary to HVR. These Li-rich stars also rotate like T Tauris. Most of the stars that lack Li are probable or possible members of the Hyades, in the foreground, and are among the brightest and most active stars in that cluster for their spectral types. It is suggested following Jones and Herbig (1979), that the apparent absence of low-mass stars older than 10 Myr in Taurus-Auriga is real, and is due to the finite lifetime of the cloud.

  6. Rotation and kinematics of the premain-sequence stars in Taurus-Auriga with CA II emission

    Science.gov (United States)

    Hartmann, Lee W.; Soderblom, David R.; Stauffer, John R.

    1987-04-01

    The authors report radial velocities and v sin i values for the stars in the Taurus-Auriga region that were found to have strong Ca II H and K emission by Herbig, Vrba, and Rydgren (HVR). Most of the velocities are determined to better than 2 km s-1 precision. The authors find the kinematic properties of the Ca II emission stars with strong Li to be indistinguishable from conventional T Tauris in Taurus-Auriga, contrary to HVR. These Li-rich stars also rotate like T Tauris. Most of the stars that lack Li are probable or possible members of the Hyades, in the foreground, and are among the brightest and most active stars in that cluster for their spectral types. The authors suggest, following Jones and Herbig, that the apparent absence of low-mass stars older than 10 Myr in Taurus-Auriga is real, and is due to the finite lifetime of the cloud.

  7. Characterization of Bacillus subtilis YfkE (ChaA): a calcium-specific Ca2+/H+ antiporter of the CaCA family.

    Science.gov (United States)

    Fujisawa, Makoto; Wada, Yuko; Tsuchiya, Takahiro; Ito, Masahiro

    2009-08-01

    YfkE, a protein from Bacillus subtilis, exhibits homology to the Ca(2+):Cation Antiporter (CaCA) Family. In a fluorescence-based assay of everted membrane vesicles prepared from Na(+)(Ca(2+))/H(+) antiporter-defective mutant Escherichia coli KNabc, YfkE exhibited robust Ca(2+)/H(+) antiport activity, with a K (m) for Ca(2+) estimated at 12.5 muM at pH 8.5 and 113 muM at pH 7.5. Neither Na(+) nor K(+) served as a substrate. Mg(2+) also did not serve as a substrate, but inhibited the Ca(2+)/H(+) antiporter activity. The Ca(2+) transport capability of YfkE was also observed directly by transport assays in everted membrane vesicles using radiolabeled (45)Ca(2+). Transcriptional analysis from the putative yfkED operon using beta-garactosidase activity as a reporter revealed that both of the yfkE and yfkD genes are regulated by forespore-specific sigma factor, SigG, and the general stress response regulator, SigB. These results suggest that YfkE may be needed for Ca(2+) signaling in the sporulation or germination process in B. subtilis. ChaA is proposed as the designation for YfkE of B. subtilis.

  8. Comparative study of anisotropic superconductivity in CaAlSi and CaGaSi

    International Nuclear Information System (INIS)

    Tamegai, T.; Uozato, K.; Kasahara, S.; Nakagawa, T.; Tokunaga, M.

    2005-01-01

    In order to get some insight into the origin of the anomalous angular dependence of H c2 in a layered intermetallic compound CaAlSi, electronic, superconducting, and structural properties are compared between CaAlSi and CaGaSi. The angular dependence of H c2 in CaGaSi is well described by the anisotropic GL model. Parallel to this finding, the pronounced lattice modulation accompanying the superstructure along the c-axis in CaAlSi is absent in CaGaSi. A relatively large specific heat jump at the superconducting transition in CaAlSi compared with CaGaSi indicates the presence of strong electron-phonon coupling in CaAlSi, which may cause the superstructure and the anomalous angular dependence of H c2

  9. Mass yield distributions for the reactions Ca+Ca, Nb+Nb and Ca+Ca at E/A=800 MeV in the molecular-dynamical model

    International Nuclear Information System (INIS)

    Kiselev, S.M.

    1987-01-01

    Mass yield distributions obtained on the basis of the molecular-dynamical model are presented for the Ca+Ca, Nb+Nb reactions at E/A=400 MeV and Ca+Ca reaction at E/A=800 MeV. For the fragments with masses upto quarter of the mass of initial nucleus the model predicts a power law for mass spectra with almost the same value of the exponent. Such the behaviour is roughly a result of the superposition of the fireball breakup and the disintegration of spectator regions rather than the evidence of a liquid-gas-like phase transition in hot nuclear matter

  10. Study on the isospin equilibration phenomenon in nuclear reactions 40Ca + 40Ca , 40Ca + 46Ti , 40Ca + 48Ca , 48Ca + 48Ca at 25 MeV/nucleon by using the CHIMERA multidetector

    Science.gov (United States)

    Martorana, N. S.; Auditore, L.; Berceanu, I.; Cardella, G.; Chatterjee, M. B.; De Luca, S.; De Filippo, E.; Dell'Aquila, D.; Gnoffo, B.; Lanzalone, G.; Lombardo, I.; Maiolino, C.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.

    2017-11-01

    We report on the results obtained by studying nuclear reactions between isotopes of Ca and Ti at 25 MeV/nucleon. We used the multidetector CHIMERA to detect charged reaction products. In particular, we studied two main effects: the isospin diffusion and the isospin drift. In order to study these processes we performed a moving-source analysis on kinetic energy spectra of the isobar nuclei ^{3H} and ^{3He} . This method allows to isolate the emission from the typical sources produced in reactions at Fermi energy: projectile like fragment (PLF), target like fragment (TLF), and mid-velocity (MV) emission. The obtained results are compared to previous experimental investigations and to simulations obtained with CoMD-II model.

  11. CaMKII in Vascular Signalling: "Friend or Foe"?

    Science.gov (United States)

    Ebenebe, Obialunanma V; Heather, Alison; Erickson, Jeffrey R

    2018-05-01

    Signalling mechanisms within and between cells of the vasculature enable function and maintain homeostasis. However, a number of these mechanisms also contribute to the pathophysiology of vascular disease states. The multifunctional signalling molecule calcium/calmodulin-dependent kinase II (CaMKII) has been shown to have critical functional effects in many tissue types. For example, CaMKII is known to have a dual role in cardiac physiology and pathology. The function of CaMKII within the vasculature is incompletely understood, but emerging evidence points to potential physiological and pathological roles. This review discusses the evidence for CaMKII signalling within the vasculature, with the aim to better understand both positive and potentially deleterious effects of CaMKII activation in vascular tissue. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  12. Ventral tegmental area disruption selectively affects CA1/CA2 but not CA3 place fields during a differential reward working memory task.

    Science.gov (United States)

    Martig, Adria K; Mizumori, Sheri J Y

    2011-02-01

    Hippocampus (HPC) receives dopaminergic (DA) projections from the ventral tegmental area (VTA) and substantia nigra. These inputs appear to provide a modulatory signal that influences HPC dependent behaviors and place fields. We examined how efferent projections from VTA to HPC influence spatial working memory and place fields when the reward context changes. CA1 and CA3 process environmental context changes differently and VTA preferentially innervates CA1. Given these anatomical data and electrophysiological evidence that implicate DA in reward processing, we predicted that CA1 place fields would respond more strongly to both VTA disruption and changes in the reward context than CA3 place fields. Rats (N = 9) were implanted with infusion cannula targeting VTA and recording tetrodes aimed at HPC. Then they were tested on a differential reward, win-shift working memory task. One recording session consisted of 5 baseline and 5 manipulation trials during which place cells in CA1/CA2 (N = 167) and CA3 (N = 94) were recorded. Prior to manipulation trials rats were infused with either baclofen or saline and then subjected to control or reward conditions during which the learned locations of large and small reward quantities were reversed. VTA disruption resulted in an increase in errors, and in CA1/CA2 place field reorganization. There were no changes in any measures of CA3 place field stability during VTA disruption. Reward manipulations did not affect performance or place field stability in CA1/CA2 or CA3; however, changes in the reward locations "rescued" performance and place field stability in CA1/CA2 when VTA activity was compromised, perhaps by trigging compensatory mechanisms. These data support the hypothesis that VTA contributes to spatial working memory performance perhaps by maintaining place field stability selectively in CA1/CA2. Copyright © 2009 Wiley-Liss, Inc.

  13. Blebbistatin, a myosin II inhibitor, suppresses Ca(2+)-induced and "sensitized"-contraction of skinned tracheal muscles from guinea pig.

    Science.gov (United States)

    Yumoto, Masatoshi; Watanabe, Masaru

    2013-01-01

    Blebbistatin, a potent inhibitor of myosin II, has inhibiting effects on Ca(2+)-induced contraction and contractile filament organization without affecting the Ca(2+)-sensitivity to the force and phosphorylation level of myosin regulatory light chain (MLC20) in skinned (cell membrane permeabilized) taenia cecum from the guinea pig (Watanabe et al., Am J Physiol Cell Physiol. 2010; 298: C1118-26). In the present study, we investigated blebbistatin effects on the contractile force of skinned tracheal muscle, in which myosin filaments organization is more labile than that in the taenia cecum. Blebbistatin at 10 μM or higher suppressed Ca(2+)-induced tension development at any given Ca(2+) concentration, but had little effects on the Ca(2+)- induced myosin light chain phosphorylation. Also blebbistatin at 10 μM and higher significantly suppressed GTP-γS-induced "sensitized" force development. Since the force inhibiting effects of blebbistatin on the skinned trachea were much stronger than those in skinned taenia cecum, blebbistatin might directly affect myosin filaments organization.

  14. Meiosis, egg activation, and nuclear envelope breakdown are differentially reliant on Ca2+, whereas germinal vesicle breakdown is Ca2+ independent in the mouse oocyte

    Science.gov (United States)

    Tombes, R. M.; Simerly, C.; Borisy, G. G.; Schatten, G.

    1992-01-01

    During early development, intracellular Ca2+ mobilization is not only essential for fertilization, but has also been implicated during other meiotic and mitotic events, such as germinal vesicle breakdown (GVBD) and nuclear envelope breakdown (NEBD). In this study, the roles of intracellular and extracellular Ca2+ were examined during meiotic maturation and reinitiation at parthenogenetic activation and during first mitosis in a single species using the same methodologies. Cumulus-free metaphase II mouse oocytes immediately resumed anaphase upon the induction of a large, transient Ca2+ elevation. This resumption of meiosis and associated events, such as cortical granule discharge, were not sensitive to extracellular Ca2+ removal, but were blocked by intracellular Ca2+ chelators. In contrast, meiosis I was dependent on external Ca2+; in its absence, the formation and function of the first meiotic spindle was delayed, the first polar body did not form and an interphase-like state was induced. GVBD was not dependent on external Ca2+ and showed no associated Ca2+ changes. NEBD at first mitosis in fertilized eggs, on the other hand, was frequently, but not always associated with a brief Ca2+ transient and was dependent on Ca2+ mobilization. We conclude that GVBD is Ca2+ independent, but that the dependence of NEBD on Ca2+ suggests regulation by more than one pathway. As cells develop from Ca(2+)-independent germinal vesicle oocytes to internal Ca(2+)-dependent pronuclear eggs, internal Ca2+ pools increase by approximately fourfold.

  15. Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

    Directory of Open Access Journals (Sweden)

    MITHLESH AGRAWAL

    2002-04-01

    Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

  16. Application value of combined measurement of serum sTn, CA242, CA19-9 and CEA in the diagnosis of gastroenterological neoplasm

    International Nuclear Information System (INIS)

    Zhang Wanzhong; Chen Zhizhou; Fan Zhenfu

    2007-01-01

    To determine the application value of four serum tumor markers sTn, CA242, CA 19-9 and CEA in the diagnosis of gastroenterological neoplasm, the serum sTn, CA242, CA19-9 and CEA in 30 normal adult controls and 60 patients with gastroenterological neoplasm were measured by IRMA. The results showed that the serum sTn, CA242, CA19-9 and CEA levels in patients with gastric carcinoma or colorectal carcinoma were much higher than those in control group (P<0.01). The serum CEA, CA19-9 and CA242 levels in patients with colorectal carcinoma were significantly higher than those in patients with gastric carcinoma (P<0.01), but the serum sTn level in the former was markedly lower (P<0.01) than that in the latter. The sensitivity of tumor marker increased with the progress of clinical stages, with a considerably higher sensitivity for stage IV compared with stage I-II (P<0.01). The combined test of four tumor markers could be more sensitive than single test in detecting gastric carcinoma and colorectal carcinoma (P<0.05). Four tumor markers are useful for diagnosing gastroenterological neoplasm, and the combined measurement of 4 tumor markers could increase the sensitivity of detecting gastric carcinoma. (authors)

  17. Extremely Elevated CA 125 and CA 19-9 in Endometrioma; A Case Series

    Directory of Open Access Journals (Sweden)

    Vugar Bayramov

    2010-03-01

    Full Text Available Although endometriosis is a benign condition, increased levels of the tumor markers CA 125 and CA 19-9 may be seen. However, these tumor markers reach to very high levels, rarely. In this report, 4 patients between 20 and 43 year-old with extremely elevated CA 125, CA 19-9 and CA 15-3 levels are discussed. In endometriosis extremely increased tumor markers are determined in the case of ruptured endometrioma cyst. There are two mechanisms to clarify extremely elevated levels of CA 125 in endometriosis. First, the peritoneal irritation of CA 125 molecule after the rupture of endometioma cyst and CA 125 secretion from the periton. And the second is penetration of the CA 125 moecule easily to the circulation through the peritoneal endothelial surface after the cyst rupture. In conclusion, the diagnosis of ruptured endometrioma cyst should be kept in mind especially in young patients with extremely elevated serum CA 125 levels with regard to the history and ultrasonographical signs and invasive procedures should be avoided.

  18. Ca isotopes in refractory inclusions

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.

    1984-01-01

    We report measurements of the absolute isotope abundance of Ca in Ca-Al-rich inclusions from the Allende and Leoville meteorites. Improved high precision measurements are reported also for 46 Ca. We find that nonlinear isotope effects in Ca are extremely rare in these inclusions. The absence of nonlinear effects in Ca, except for the effects in FUN inclusions, is in sharp contrast to the endemic effects in Ti. One fine-grained inclusion shows an excess of 46 Ca of (7 +- 1) per mille, which is consistent with addition of only 46 Ca or of an exotic (*) component with 46 Ca* approx. 48 Ca*. FUN inclusion EK-1-4-1 shows a small 46 Ca excess of (3.3 +- 1.0) per mille; this confirms that the exotic Ca components in EK-1-4-1 were even more deficient in 46 Ca relative to 48 Ca than is the case for normal Ca. The Ca in the Ca-Al-rich inclusions shows mass dependent isotope fractionation effects which have a range from -3.8 to +6.7 per mille per mass unit difference. This range is a factor of 20 wider than the range previously established for bulk meteorites and for terrestrial and lunar samples. Ca and Mg isotope fractionation effects in the Ca-Al-rich inclusions are common and attributed to kinetic isotope effects. (author)

  19. Clinical evaluation of CEA, CA19-9, CA72-4 and CA125 in gastric cancer patients with neoadjuvant chemotherapy.

    Science.gov (United States)

    Sun, Zhipeng; Zhang, Nengwei

    2014-12-29

    In the clinical practice of neoadjuvant chemotherapy, response markers are very important. We aimed o investigate whether tumor markers CEA(carcino-embryonic antigen), CA19-9(carbohydrate antigen 19-9), CA72-4(carbohydrate antigen 72-4), and CA125(carbohydrate antigen 125) can be used to evaluate the response to neoadjuvant chemotherapy, and to evaluate the diagnosis and prognosis value of four tumor markers in the patients of gastric cancer. A retrospective review was performed of 184 gastric cancer patients who underwent a 5-Fu, leucovorin, and oxaliplatin (FOLFOX) neoadjuvant chemotherapy regimen, followed by surgical treatment. Blood samples for CEA, CA19-9, CA72-4, and CA125 levels were taken from patients upon admission to the hospital and after neoadjuvant chemotherapy. Statistical analysis was performed to identify the clinical value of these tumor markers in predicting the survival and the response to neoadjuvant chemotherapy. Median overall survival times of pretreatment CA19-9-positive and CA72-4-positive patients (14.0 +/-2.8 months and 14.8 +/-4.0 months, respectively) were significantly less than negative patients (32.5 +/-8.9 months and 34.0 +/-10.1 months, respectively) (P = 0.000 and P = 0.002, respectively). Pretreatment status of CA19-9 and CA72-4 were independent prognostic factors in gastric cancer patients (P = 0.029 and P = 0.008, respectively). Pretreatment CEA >50 ng/ml had a positive prediction value for clinical disease progression after neoadjuvant chemotherapy according to the ROC curve (AUC: 0.694, 95% CI: 0.517 to 0.871, P = 0.017). The decrease of tumor markers CEA, CA72-4, and CA125 was significant after neoadjuvant chemotherapy (P = 0.030, P = 0.010, and P = 0.009, respectively), especially in patients with disease control (including complete, partial clinical response, and stable disease) (P = 0.012, P = 0.020, and P = 0.025, respectively). A decrease in CA72-4 by more than 70% had

  20. High-Order Ca(II)-Chloro Complexes in Mixed CaCl2-LiCl Aqueous Solution: Insights from Density Functional Theory and Molecular Dynamics Simulations.

    Science.gov (United States)

    Wang, Yu-Lin; Wang, Ying; Yi, Hai-Bo

    2016-07-21

    In this study, the structural characteristics of high-coordinated Ca-Cl complexes present in mixed CaCl2-LiCl aqueous solution were investigated using density functional theory (DFT) and molecular dynamics (MD) simulations. The DFT results show that [CaClx](2-x) (x = 4-6) clusters are quite unstable in the gas phase, but these clusters become metastable when hydration is considered. The MD simulations show that high-coordinated Ca-chloro complexes are possible transient species that exist for up to nanoseconds in concentrated (11.10 mol·kg(-1)) Cl(-) solution at 273 and 298 K. As the temperature increases to 423 K, these high-coordinated structures tend to disassociate and convert into smaller clusters and single free ions. The presence of high-order Ca-Cl species in concentrated LiCl solution can be attributed to their enhanced hydration shell and the inadequate hydration of ions. The probability of the [CaClx](2-x)aq (x = 4-6) species being present in concentrated LiCl solution decreases greatly with increasing temperature, which also indicates that the formation of the high-coordinated Ca-Cl structure is related to its hydration characteristics.

  1. Evaluation of Serum CEA, CA19-9, CA72-4, CA125 and Ferritin as Diagnostic Markers and Factors of Clinical Parameters for Colorectal Cancer.

    Science.gov (United States)

    Gao, Yanfeng; Wang, Jinping; Zhou, Yue; Sheng, Sen; Qian, Steven Y; Huo, Xiongwei

    2018-02-09

    Blood-based protein biomarkers have recently shown as simpler diagnostic modalities for colorectal cancer, while their association with clinical pathological characteristics is largely unknown. In this study, we not only examined the sensitivity and reliability of single/multiple serum markers for diagnosis, but also assessed their connection with pathological parameters from a total of 279 colorectal cancer patients. Our study shown that glycoprotein carcinoembryonic antigen (CEA) owns the highest sensitivity among single marker in the order of CEA > cancer antigen 72-4 (CA72-4) > cancer antigen 19-9 9 (CA19-9) > ferritin > cancer antigen 125 (CA125), while the most sensitive combined-markers for two to five were: CEA + CA72-4; CEA + CA72-4 + CA125; CEA + CA19-9 + CA72-4 + CA125; and CEA + CA19-9 + CA72-4 + CA125 + ferritin, respectively. We also demonstrated that patients who had positive preoperative serum CEA, CA19-9, or CA72-4 were more likely with lymph node invasion, positive CA125 were prone to have vascular invasion, and positive CEA or CA125 were correlated with perineural invasion. In addition, positive CA19-9, CA72-4, or CA125 was associated with poorly differentiated tumor, while CEA, CA19-9, CA72-4, CA125 levels were positively correlated with pathological tumor-node-metastasis stages. We here conclude that combined serum markers can be used to not only diagnose colorectal cancer, but also appraise the tumor status for guiding treatment, evaluation of curative effect, and prognosis of patients.

  2. Metallicities for old stellar systems from Ca II triplet strengths in member giants

    International Nuclear Information System (INIS)

    Armandroff, T.E.; Da costa, G.S.

    1991-01-01

    The spectra of giants in six well-studied Galactic globulars spanning a wide range of abundance are used to investigate the utility of the Ca II triplet as an abundance indicator. The calibration resulting from these clusters is used to derive metal abundances from the spectra of giants in Eridanus, Pal 12, and the Carina dwarf spheroidal galaxy. The results obtained are compared with earlier determinations based on giant branch photometry. 37 refs

  3. The diagnostic value of determination of serum GOLPH3 associated with CA125, CA19.9 in patients with ovarian cancer.

    Science.gov (United States)

    Fan, H-Y; Duan, D-M; Liu, Y-F

    2017-09-01

    To evaluate the value of three tumor markers serum Golgi phosphoprotein-3 (GOLPH3), cancer antigen 125 (CA125) and cancer antigen 19-9 (CA19.9) in the diagnosis and postoperative evaluation of ovarian cancer by detecting these three markers. A total of 187 patients were studied and included in the ovarian cancer group, benign pelvic mass group, and the normal control group. The levels of serum Golgi phosphoprotein-3 (GOLPH3), cancer antigen 125 (CA125) and cancer antigen 199 (CA19.9) were detected, respectively, and their effects on the diagnosis, evaluation, pathology typing and staging of ovarian cancer were measured. The sensitivity of the detection of ovarian cancer by GOLPH3 combined with CA125 and CA19.9 was higher than that by a single marker (pserum GOLPH3 in patients with serous and endometrioid carcinoma was significantly higher than that in patients with mucinous carcinoma, clear-cell carcinoma and germ cell tumor (pserum GOLPH3 level between patients with ovarian malignancies at stage III-IV and those at stage I-II (p>0.05). The levels of serum GOLPH3, CA125 and CA19.9 in patients with ovarian malignancies after surgery were significantly lower than those before surgery (p<0.05). The combined detection by GOLPH3, CA125, and CA19.9 may improve the diagnosis rate of ovarian epithelial cancer. GOLPH3, as a new ovarian cancer tumor marker used in clinical diagnosis, is expected to become an important indicator for the early diagnosis of ovarian cancer and the determination of clinical surgery efficacy.

  4. Cell type-specific genetic and optogenetic tools reveal hippocampal CA2 circuits.

    Science.gov (United States)

    Kohara, Keigo; Pignatelli, Michele; Rivest, Alexander J; Jung, Hae-Yoon; Kitamura, Takashi; Suh, Junghyup; Frank, Dominic; Kajikawa, Koichiro; Mise, Nathan; Obata, Yuichi; Wickersham, Ian R; Tonegawa, Susumu

    2014-02-01

    The formation and recall of episodic memory requires precise information processing by the entorhinal-hippocampal network. For several decades, the trisynaptic circuit entorhinal cortex layer II (ECII)→dentate gyrus→CA3→CA1 and the monosynaptic circuit ECIII→CA1 have been considered the primary substrates of the network responsible for learning and memory. Circuits linked to another hippocampal region, CA2, have only recently come to light. Using highly cell type-specific transgenic mouse lines, optogenetics and patch-clamp recordings, we found that dentate gyrus cells, long believed to not project to CA2, send functional monosynaptic inputs to CA2 pyramidal cells through abundant longitudinal projections. CA2 innervated CA1 to complete an alternate trisynaptic circuit, but, unlike CA3, projected preferentially to the deep, rather than to the superficial, sublayer of CA1. Furthermore, contrary to existing knowledge, ECIII did not project to CA2. Our results allow a deeper understanding of the biology of learning and memory.

  5. Study of 40Ca-40Ca elastic scattering at intermediate energy

    International Nuclear Information System (INIS)

    Kumar, Ashok; Srivastava, B.B.

    1980-01-01

    The differential cross sections for 40 Ca- 40 Ca elastic scattering have been calculated at laboratory incident energy of 240 MeV using a sharp cut off of the partial waves below a critical angular momentum, 1sub(c)' to account for absorption. The effective 40 Ca- 40 Ca potential is taken to be the sum of a real nuclear potential and the Coulomb potential. The calculated differential cross sections which are in fair agreement with the experimental data are presented and discussed. (author)

  6. INTRACELLULAR Ca2+ HOMEOSTASIS

    Directory of Open Access Journals (Sweden)

    Shahdevi Nandar Kurniawan

    2015-01-01

    Full Text Available Ca2+ signaling functions to regulate many cellular processes. Dynamics of Ca2+ signaling or homeostasis is regulated by the interaction between ON and OFF reactions that control Ca2+ flux in both the plasma membrane and internal organelles such as the endoplasmic reticulum (ER and mitochondria. External stimuli activate the ON reactions, which include Ca2+ into the cytoplasm either through channels in the plasma membrane or from internal storage like in ER. Most of the cells utilize both channels/sources, butthere area few cells using an external or internal source to control certain processes. Most of the Ca2+ entering the cytoplasm adsorbed to the buffer, while a smaller part activate effect or to stimulate cellular processes. Reaction OFF is pumping of cytoplasmic Ca2+ using a combination mechanism of mitochondrial and others. Changes in Ca2+ signal has been detected in various tissues isolated from animals induced into diabetes as well as patients with diabetes. Ca2+ signal interference is also found in sensory neurons of experimental animals with diabetes. Ca2+ signaling is one of the main signaling systems in the cell.

  7. F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling.

    Science.gov (United States)

    Lange, Klaus; Gartzke, Joachim

    2006-11-01

    A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. Copyright 2006 Wiley-Liss, Inc.

  8. The other side of cardiac Ca2+ signaling: transcriptional control

    Directory of Open Access Journals (Sweden)

    Alejandro eDomínguez-Rodríquez

    2012-11-01

    Full Text Available Ca2+ is probably the most versatile signal transduction element used by all cell types. In the heart, it is essential to activate cellular contraction in each heartbeat. Nevertheless Ca2+ is not only a key element in excitation-contraction coupling (EC coupling, but it is also a pivotal second messenger in cardiac signal transduction, being able to control processes such as excitability, metabolism, and transcriptional regulation. Regarding the latter, Ca2+ activates Ca2+-dependent transcription factors by a process called excitation-transcription coupling (ET coupling. ET coupling is an integrated process by which the common signaling pathways that regulate EC coupling activate transcription factors. Although ET coupling has been extensively studied in neurons and other cell types, less is known in cardiac muscle. Some hints have been found in studies on the development of cardiac hypertrophy, where two Ca2+-dependent enzymes are key actors: Ca2+/Calmodulin kinase II (CaMKII and phosphatase calcineurin, both of which are activated by the complex Ca2+/ /Calmodulin. The question now is how ET coupling occurs in cardiomyocytes, where intracellular Ca2+ is continuously oscillating. In this focused review, we will draw attention to location of Ca2+ signaling: intranuclear ([Ca2+]n or cytoplasmic ([Ca2+]c, and the specific ionic channels involved in the activation of cardiac ET coupling. Specifically, we will highlight the role of the 1,4,5 inositol triphosphate receptors (IP3Rs in the elevation of [Ca2+]n levels, which are important to locally activate CaMKII, and the role of transient receptor potential channels canonical (TRPCs in [Ca2+]c, needed to activate calcineurin.

  9. Changes in the expression of serum markers CA242, CA199, CA125, CEA, TNF-α and TSGF after cryosurgery in pancreatic cancer patients.

    Science.gov (United States)

    Zhou, Gang; Niu, Lizhi; Chiu, David; He, Lihua; Xu, Kecheng

    2012-07-01

    The presence of serum tumor markers, carbohydrate antigen 242 (CA242), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), tumor-supplied group of factors (TSGF) and tumor necrosis factor-α (TNF-α), is closely associated with invasion and metastasis of many malignancies. The expression of these markers were measured in serum taken from 37 pancreatic cancer patients prior to treatment. Levels of CA242, CA199, CA125, CEA and TNF-α expression correlated with tumor size, clinical stage, tumor differentiation, lymph node and liver metastasis (P markers were significantly reduced compared with levels prior to cryosurgery (P 0.05). Thus, cryosurgery is more effective than chemotherapy for decreasing CA242, CA199, CA125, CEA, TSGF and TNF-α serum levels in these patients.

  10. Regulated release of Ca2+ from respiring mitochondria by Ca2+/2H+ antiport.

    Science.gov (United States)

    Fiskum, G; Lehninger, A L

    1979-07-25

    Simultaneous measurements of oxygen consumption and transmembrane transport of Ca2+, H+, and phosphate show that the efflux of Ca2+ from respiring tightly coupled rat liver mitochondria takes place by an electroneutral Ca2+/2H+ antiport process that is ruthenium red-insensitive and that is regulated by the oxidation-reduction state of the mitochondrial pyridine nucleotides. When mitochondrial pyridine nucleotides are kept in a reduced steady state, the efflux of Ca2+ is inhibited; when they are in an oxidized state, Ca2+ efflux is activated. These processes were demonstrated by allowing phosphate-depleted mitochondria respiring on succinate in the presence of rotenone to take up Ca2+ from the medium. Upon subsequent addition of ruthenium red to block Ca2+ transport via the electrophoretic influx pathway, and acetoacetate, to bring mitochondrial pyridine nucleotides into the oxidized state, Ca2+ efflux and H+ influx ensued. The observed H+ influx/Ca2+ efflux ratio was close to the value 2.0 predicted for the operation of an electrically neutral Ca2+/2H+ antiport process.

  11. Applicative Value of Serum CA19-9, CEA, CA125 and CA242 in Diagnosis and Prognosis for Patients with Pancreatic Cancer Treated by Concurrent Chemoradiotherapy.

    Science.gov (United States)

    Gu, Yu-Lei; Lan, Chao; Pei, Hui; Yang, Shuang-Ning; Liu, Yan-Fen; Xiao, Li-Li

    2015-01-01

    To evaluate the application value of serum CA19-9, CEA, CA125 and CA242 in diagnosis and prognosis of pancreatic cancer cases treated with concurrent chemotherapy. 52 patients with pancreatic cancer, 40 with benign pancreatic diseases and 40 healthy people were selected. The electrochemiluminescence immunoassay method was used for detecting levels of CA19-9, CEA and CA125, and a CanAg CA242 enzyme linked immunoassay kit for assessing the level of CA242. The Kaplan-Meier method was used for analyzing the prognostic factors of patients with pancreatic cancer. The Cox proportional hazard model was applied for analyzing the hazard ratio (HR) and 95% confidential interval (CI) for survival time of patients with pancreatic cancer. The levels of serum CA19-9, CEA, CA125 and CA242 in patients with pancreatic cancer were significantly higher than those in patients with benign pancreatic diseases and healthy people (PCEA. The specificity of CA242 is the highest, followed by CA125, CEA and CA19-9. The sensitivity and specificity of joint detection of serum CA19-9, CEA, CA125and CA242 were 90.4% and 93.8%, obviously higher than single detection of those markers in diagnosis of pancreatic cancer. The median survival time of 52 patients with pancreatic cancer was 10 months (95% CI7.389~12.611).. Patients with the increasing level of serum CA19-9, CEA, CA125, CA242 had shorter survival times (P=0.047. 0.043, 0.0041, 0.029). COX regression analysis showed that CA19-9 was an independent prognostic factor for patients with pancreatic cancer (P=0.001, 95%CI 2.591~38.243). The detection of serum tumor markers (CA19.9, CEA, CA125 and CA242) is conducive to the early diagnosis of pancreatic cancer and joint detection of tumor markers helps improve the diagnostic efficiency. Moreover, CA19-9 is an independent prognostic factor for patients with pancreatic cancer.

  12. CaMKII content affects contractile, but not mitochondrial, characteristics in regenerating skeletal muscle

    NARCIS (Netherlands)

    Eilers, W.; Jaspers, R.T.; de Haan, A.; Ferrié, C.; Valdivieso, P.; Flueck, M.

    2014-01-01

    Background: The multi-meric calcium/calmodulin-dependent protein kinase II (CaMKII) is the main CaMK in skeletal muscle and its expression increases with endurance training. CaMK family members are implicated in contraction-induced regulation of calcium handling, fast myosin type IIA expression and

  13. Structural insights into the light-driven auto-assembly process of the water-oxidizing Mn4CaO5-cluster in photosystem II.

    Science.gov (United States)

    Zhang, Miao; Bommer, Martin; Chatterjee, Ruchira; Hussein, Rana; Yano, Junko; Dau, Holger; Kern, Jan; Dobbek, Holger; Zouni, Athina

    2017-07-18

    In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light-driven splitting of water at a protein-bound Mn 4 CaO 5 -cluster, the water-oxidizing complex (WOC). In the photosynthetic organisms, the light-driven formation of the WOC from dissolved metal ions is a key process because it is essential in both initial activation and continuous repair of PSII. Structural information is required for understanding of this chaperone-free metal-cluster assembly. For the first time, we obtained a structure of PSII from Thermosynechococcus elongatus without the Mn 4 CaO 5 -cluster. Surprisingly, cluster-removal leaves the positions of all coordinating amino acid residues and most nearby water molecules largely unaffected, resulting in a pre-organized ligand shell for kinetically competent and error-free photo-assembly of the Mn 4 CaO 5 -cluster. First experiments initiating (i) partial disassembly and (ii) partial re-assembly after complete depletion of the Mn 4 CaO 5 -cluster agree with a specific bi-manganese cluster, likely a di-µ-oxo bridged pair of Mn(III) ions, as an assembly intermediate.

  14. Anticancer ruthenium(III) complex KP1019 interferes with ATP-dependent Ca2+ translocation by sarco-endoplasmic reticulum Ca2+-ATPase (SERCA).

    Science.gov (United States)

    Sadafi, Fabrizio-Zagros; Massai, Lara; Bartolommei, Gianluca; Moncelli, Maria Rosa; Messori, Luigi; Tadini-Buoninsegni, Francesco

    2014-08-01

    Sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), a P-type ATPase that sustains Ca2+ transport and plays a major role in intracellular Ca2+ homeostasis, represents a therapeutic target for cancer therapy. Here, we investigated whether ruthenium-based anticancer drugs, namely KP1019 (indazolium [trans-tetrachlorobis(1H-indazole)ruthenate(III)]), NAMI-A (imidazolium [trans-tetrachloro(1H-imidazole)(S-dimethylsulfoxide)ruthenate(III)]) and RAPTA-C ([Ru(η6-p-cymene)dichloro(1,3,5-triaza-7-phosphaadamantane)]), and cisplatin (cis-diammineplatinum(II) dichloride) might act as inhibitors of SERCA. Charge displacement by SERCA adsorbed on a solid-supported membrane was measured after ATP or Ca2+ concentration jumps. Our results show that KP1019, in contrast to the other metal compounds, is able to interfere with ATP-dependent translocation of Ca2+ ions. An IC50 value of 1 μM was determined for inhibition of calcium translocation by KP1019. Conversely, it appears that KP1019 does not significantly affect Ca2+ binding to the ATPase from the cytoplasmic side. Inhibition of SERCA at pharmacologically relevant concentrations may represent a crucial aspect in the overall pharmacological and toxicological profile of KP1019. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Clinical significance of combined determination of the changes of serum IGF-II, CA19-9 and AFP levels after intervention therapy in patients with primary hepatic cancer

    International Nuclear Information System (INIS)

    Wang Zhong

    2007-01-01

    Objective: To investigate the clinical significance of changes of serum IGF-II, CA19-9 and AFP levels after intervention therapy in patients with primary hepatic cancer. Methods: Serum levels of IGF-II, CA19-9 and AFP (with RIA) were repeatedly determined in 35 patients with primary hepatic cancer before intervention therapy, 1 month after intervention therapy and 6 months after intervention therapy as well as in 30 controls. Results: Before intervention therapy, serum levels of IGF-II, CA19-9 and AFP in the patients were significantly higher than those in the controls (P <0.01 ). One month after intervention therapy, all the serum levels were approaching normal. Six months later, the levels in the patients without recurrence remained normal. However, the levels in the 6 patients with recurrence returued to those before intervention therapy again. Conclusion: Changes of serum IGF-II, CA19-9 and AFP levels are closely related to the tumor burden and may reflect the presence of recurrence. (authors)

  16. The CaV2.3 R-type voltage-gated Ca2+ channel in mouse sleep architecture.

    Science.gov (United States)

    Siwek, Magdalena Elisabeth; Müller, Ralf; Henseler, Christina; Broich, Karl; Papazoglou, Anna; Weiergräber, Marco

    2014-05-01

    Voltage-gated Ca(2+) channels (VGCCs) are key elements in mediating thalamocortical rhythmicity. Low-voltage activated (LVA) CaV 3 T-type Ca(2+) channels have been related to thalamic rebound burst firing and to generation of non-rapid eye movement (NREM) sleep. High-voltage activated (HVA) CaV 1 L-type Ca(2+) channels, on the opposite, favor the tonic mode of action associated with higher levels of vigilance. However, the role of the HVA Non-L-type CaV2.3 Ca(2+) channels, which are predominantly expressed in the reticular thalamic nucleus (RTN), still remains unclear. Recently, CaV2.3(-/-) mice were reported to exhibit altered spike-wave discharge (SWD)/absence seizure susceptibility supported by the observation that CaV2.3 mediated Ca(2+) influx into RTN neurons can trigger small-conductance Ca(2+)-activated K(+)-channel type 2 (SK2) currents capable of maintaining thalamic burst activity. Based on these studies we investigated the role of CaV2.3 R-type Ca(2+) channels in rodent sleep. The role of CaV2.3 Ca(2+) channels was analyzed in CaV2.3(-/-) mice and controls in both spontaneous and artificial urethane-induced sleep, using implantable video-EEG radiotelemetry. Data were analyzed for alterations in sleep architecture using sleep staging software and time-frequency analysis. CaV2.3 deficient mice exhibited reduced wake duration and increased slow-wave sleep (SWS). Whereas mean sleep stage durations remained unchanged, the total number of SWS epochs was increased in CaV2.3(-/-) mice. Additional changes were observed for sleep stage transitions and EEG amplitudes. Furthermore, urethane-induced SWS mimicked spontaneous sleep results obtained from CaV2.3 deficient mice. Quantitative Real-time PCR did not reveal changes in thalamic CaV3 T-type Ca(2+) channel expression. The detailed mechanisms of SWS increase in CaV2.3(-/-) mice remain to be determined. Low-voltage activated CaV2.3 R-type Ca(2+) channels in the thalamocortical loop and extra

  17. Regulation of CaMKII signaling in cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Mariya Yordanova Mollova

    2015-08-01

    Full Text Available Heart failure (HF is a major cause of death in the developed countries. (Murray and Lopez, 1996;Koitabashi and Kass, 2012. Adverse cardiac remodeling that precedes heart muscle dysfunction is characterized by a myriad of molecular changes affecting the cardiomyocyte. Among these, alterations in protein kinase pathways play often an important mediator role since they link upstream pathologic stress signaling with downstream regulatory programs and thus affect both the structural and functional integrity of the heart muscle. In the context of cardiac disease, a profound understanding for the overriding mechanisms that regulate protein kinase activity (protein-protein interactions, post-translational modifications, or targeting via anchoring proteins is crucial for the development of specific and effective pharmacological treatment strategies targeting the failing myocardium.In this review, we focus on several mechanisms of upstream regulation of Ca2+/Calmodulin-dependent kinase II (CaM Kinase II, CaMKII that play a relevant pathophysiological role in the development and progression of cardiovascular disease; precise targeting of these mechanisms might therefore represent novel and promising tools for prevention and treatment of HF.

  18. Rates for some reactions involving 42Ca and 44Ca

    International Nuclear Information System (INIS)

    Cheng, C.W.; King, J.D.

    1980-01-01

    Ground-state reaction rates have been deduced from recent cross section measurements for the 42 CA(α, n) 45 Ti, 42 Ca(p, γ) 43 Sc, and 44 Ca(p, n) 44 Sc reactions. Comparison of these rates with those calculated from a statistical model of nuclear reactions. (Woosley et al) shows good agreement for the first two, but the 44 Ca(p, n) rate is more than a factor of 2 less than the theoretical prediction. Stellar reaction rates have been derived from the ground-state rates by multiplying the ground-state rates by the ratio of stellar to ground-state rates given by the statistical model. Both ground-state and stellar rates have been represented by analytic functions of the temperature. The role of these reactions in the approach to quasi-equilibrium during explosive silicon burning is discussed

  19. Mg-Ca Alloys Produced by Reduction of CaO: Understanding of ECO-Mg Alloy Production

    Science.gov (United States)

    Jung, In-Ho; Lee, Jin Kyu; Kim, Shae K.

    2017-04-01

    There have been long debates about the environment conscious (ECO) Mg technology which utilizes CaO to produce Ca-containing Mg alloys. Two key process technologies of the ECO-Mg process are the chemical reduction of CaO by liquid Mg and the maintenance of melt cleanliness during the alloying of Ca. Thermodynamic calculations using FactSage software were performed to explain these two key issues. In addition, an experimental study was performed to compare the melt cleanliness of the Ca-containing Mg alloys produced by the conventional route with metallic Ca and the ECO-Mg route with CaO.

  20. Spectropolarimetric Inversions of the Ca II 8542 Å Line in an M-class Solar Flare

    Science.gov (United States)

    Kuridze, D.; Henriques, V. M. J.; Mathioudakis, M.; Rouppe van der Voort, L.; de la Cruz Rodríguez, J.; Carlsson, M.

    2018-06-01

    We study the M1.9-class solar flare SOL2015-09-27T10:40 UT using high-resolution full Stokes imaging spectropolarimetry of the Ca II 8542 Å line obtained with the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope. Spectropolarimetric inversions using the non-LTE code NICOLE are used to construct semiempirical models of the flaring atmosphere to investigate the structure and evolution of the flare temperature and magnetic field. A comparison of the temperature stratification in flaring and nonflaring areas reveals strong heating of the flare ribbon during the flare peak. The polarization signals of the ribbon in the chromosphere during the flare maximum become stronger when compared to its surroundings and to pre- and post-flare profiles. Furthermore, a comparison of the response functions to perturbations in the line-of-sight magnetic field and temperature in flaring and nonflaring atmospheres shows that during the flare, the Ca II 8542 Å line is more sensitive to the lower atmosphere where the magnetic field is expected to be stronger. The chromospheric magnetic field was also determined with the weak-field approximation, which led to results similar to those obtained with the NICOLE inversions.

  1. The study of skeletal calcium metabolism with 41Ca and 45Ca

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Beck, Belinda; Bierman, June M.; Caffee, Marc W.; Heaney, Robert P.; Holloway, Leah; Marcus, Robert; Southon, John R.; Vogel, John S.

    2000-10-01

    The living skeleton can be labeled for life by the administration of radiologically trivial amounts of 41Ca tracer. After initial elimination of tracer from the readily exchangeable calcium pools subsequent skeletal calcium turnover maintains and modulates the urine 41Ca content. Uniquely, bone calcium metabolism may then be studied with tracer in near equilibrium with the body's calcium and resorbing calcium directly measured by accelerator mass spectrometry (AMS) of excreta. Our experiments with 25 41Ca labeled subjects demonstrate excellent diurnal stability and remarkable response to intervention of the urine signal. Thus the tracer method may prove a competitive means of measuring the effects of antiresorptive osteoporosis treatments, for therapy development or even clinical monitoring. Novel studies of long-term skeletal evolution are also possible. We realize that routinely administered short-lived calcium radiotracers contain 41Ca impurities and that thousands of experimental participants have been historically inadvertently 41Ca labeled. The 41Ca urine index might now rapidly further be characterized by contemporary measurements of these one-time subjects, and with their by now thoroughly skeleton-equilibrated tracer they might be ideal participants in other new experiments. We are also investigating 45Ca AMS. It may prove preferable to label the skeleton with this radiotracer already familiar to bioscientists, but new to AMS.

  2. 2,5-hexanedione (HD) treatment alters calmodulin, Ca2+/calmodulin-dependent protein kinase II, and protein kinase C in rats' nerve tissues

    International Nuclear Information System (INIS)

    Wang Qingshan; Hou Liyan; Zhang Cuili; Zhao Xiulan; Yu Sufang; Xie, Ke-Qin

    2008-01-01

    Calcium-dependent mechanisms, particularly those mediated by Ca 2+ /calmodulin (CaM)-dependent protein kinase II (CaMKII), have been implicated in neurotoxicant-induced neuropathy. However, it is unknown whether similar mechanisms exist in 2,5-hexanedione (HD)-induced neuropathy. For that, we investigated the changes of CaM, CaMKII, protein kinase C (PKC) and polymerization ratios (PRs) of NF-L, NF-M and NF-H in cerebral cortex (CC, including total cortex and some gray), spinal cord (SC) and sciatic nerve (SN) of rats treated with HD at a dosage of 1.75 or 3.50 mmol/kg for 8 weeks (five times per week). The results showed that CaM contents in CC, SC and SN were significantly increased, which indicated elevation of Ca 2+ concentrations in nerve tissues. CaMKII contents and activities were also increased in CC and were positively correlated with gait abnormality, but it could not be found in SC and SN. The increases of PKC contents and activities were also observed in SN and were positively correlated with gait abnormality. Except for that of NF-M in CC, the PRs of NF-L, NF-M and NF-H were also elevated in nerve tissues, which was consistent with the activation of protein kinases. The results suggested that CaMKII might be partly (in CC but not in SC and SN) involved in HD-induced neuropathy. CaMKII and PKC might mediate the HD neurotoxicity by altering the NF phosphorylation status and PRs

  3. Structural, electronic, elastic, and thermodynamic properties of CaSi, Ca2Si, and CaSi2 phases from first-principles calculations

    Science.gov (United States)

    Li, X. D.; Li, K.; Wei, C. H.; Han, W. D.; Zhou, N. G.

    2018-06-01

    The structural, electronic, elastic, and thermodynamic properties of CaSi, Ca2Si, and CaSi2 are systematically investigated by using first-principles calculations method based on density functional theory (DFT). The calculated formation enthalpies and cohesive energies show that CaSi2 possesses the greatest structural stability and CaSi has the strongest alloying ability. The structural stability of the three phases is compared according to electronic structures. Further analysis on electronic structures indicates that the bonding of these phases exhibits the combinations of metallic, covalent, and ionic bonds. The elastic constants are calculated, and the bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and anisotropy factor of polycrystalline materials are deduced. Additionally, the thermodynamic properties were theoretically predicted and discussed.

  4. Accessing the nuclear symmetry energy in Ca+Ca collisions

    Directory of Open Access Journals (Sweden)

    Chbihi A.

    2012-07-01

    Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.

  5. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    Directory of Open Access Journals (Sweden)

    Wouter Eilers

    2014-01-01

    Full Text Available We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis and slow-type muscle (soleus for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02. In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII.

  6. Ca2+ signaling in injured in situ endothelium of rat aorta.

    Science.gov (United States)

    Berra-Romani, Roberto; Raqeeb, Abdul; Avelino-Cruz, José Everardo; Moccia, Francesco; Oldani, Amanda; Speroni, Francisco; Taglietti, Vanni; Tanzi, Franco

    2008-09-01

    The inner wall of excised rat aorta was scraped by a microelectrode and Ca2+ signals were investigated by fluorescence microscopy in endothelial cells (ECs) directly coupled with injured cells. The injury caused an immediate increase in the intracellular Ca2+ concentration ([Ca2+]i), followed by a long-lasting decay phase due to Ca2+ influx from extracellular space. The immediate response was mainly due to activation of purinergic receptors, as shown by the effect of P2X and P2Y receptors agonists and antagonists, such as suramin, alpha,beta-MeATP, MRS-2179 and 2-MeSAMP. Inhibition of store-operated Ca2+ influx did not affect either the peak response or the decay phase. Furthermore, the latter was: (i) insensitive to phospholipase C inhibition, (ii) sensitive to the gap junction blockers, palmitoleic acid, heptanol, octanol and oleamide, and (iii) sensitive to La3+ and Ni2+, but not to Gd3+. Finally, ethidium bromide or Lucifer Yellow did not enter ECs facing the scraped area. These results suggest that endothelium scraping: (i) causes a short-lasting stimulation of healthy ECs by extracellular nucleotides released from damaged cells and (ii) uncouples the hemichannels of the ECs facing the injury site; these hemichannels do not fully close and allow a long-lasting Ca2+ entry.

  7. Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.

    Directory of Open Access Journals (Sweden)

    Xiao-Chen Li

    Full Text Available Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca(2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca(2+ current (I(Ca was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of I(Ca did not compromise the Ca(2+-induced Ca(2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of I(Ca. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca(2+ removal were more rapid in ground squirrels. Ca(2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high I(Ca threshold, low SR Ca(2+ leak and rapid cytosolic Ca(2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca(2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca(2+ overload-related heart diseases.

  8. Physiological and Pathological Roles of CaMKII-PP1 Signaling in the Brain

    Directory of Open Access Journals (Sweden)

    Norifumi Shioda

    2017-12-01

    Full Text Available Ca2+/calmodulin (CaM-dependent protein kinase II (CaMKII, a multifunctional serine (Ser/threonine (Thr protein kinase, regulates diverse activities related to Ca2+-mediated neuronal plasticity in the brain, including synaptic activity and gene expression. Among its regulators, protein phosphatase-1 (PP1, a Ser/Thr phosphatase, appears to be critical in controlling CaMKII-dependent neuronal signaling. In postsynaptic densities (PSDs, CaMKII is required for hippocampal long-term potentiation (LTP, a cellular process correlated with learning and memory. In response to Ca2+ elevation during hippocampal LTP induction, CaMKIIα, an isoform that translocates from the cytosol to PSDs, is activated through autophosphorylation at Thr286, generating autonomous kinase activity and a prolonged Ca2+/CaM-bound state. Moreover, PP1 inhibition enhances Thr286 autophosphorylation of CaMKIIα during LTP induction. By contrast, CaMKII nuclear import is regulated by Ser332 phosphorylation state. CaMKIIδ3, a nuclear isoform, is dephosphorylated at Ser332 by PP1, promoting its nuclear translocation, where it regulates transcription. In this review, we summarize physio-pathological roles of CaMKII/PP1 signaling in neurons. CaMKII and PP1 crosstalk and regulation of gene expression is important for neuronal plasticity as well as survival and/or differentiation.

  9. Mg and Ca isotope fractionation during CaCO3 biomineralisation

    International Nuclear Information System (INIS)

    Chang, Veronica T.-C.; Williams, R.J.P.; Makishima, Akio; Belshawl, Nick S.; O'Nions, R. Keith

    2004-01-01

    The natural variation of Mg and Ca stable isotopes of carbonates has been determined in carbonate skeletons of perforate foraminifera and reef coral together with Mg/Ca ratios to assess the influence of biomineralisation processes. The results for coral aragonite suggest its formation, in terms of stable isotope behaviour, approximates to inorganic precipitation from a seawater reservoir. In contrast, results for foraminifera calcite suggest a marked biological control on Mg isotope ratios presumably related to its low Mg content compared with seawater. The bearing of these observations on the use of Mg and Ca isotopes as proxies in paleoceanography is considered

  10. Effects of Ca on microstructure, mechanical and corrosion properties and biocompatibility of Mg-Zn-Ca alloys.

    Science.gov (United States)

    Yin, Ping; Li, Nian Feng; Lei, Ting; Liu, Lin; Ouyang, Chun

    2013-06-01

    Zn and Ca were selected as alloying elements to develop an Mg-Zn-Ca alloy system for biomedical application due to their good biocompatibility. The effects of Ca on the microstructure, mechanical and corrosion properties as well as the biocompatibility of the as-cast Mg-Zn-Ca alloys were studied. Results indicate that the microstructure of Mg-Zn-Ca alloys typically consists of primary α-Mg matrix and Ca₂Mg₆Zn₃/Mg₂Ca intermetallic phase mainly distributed along grain boundary. The yield strength of Mg-Zn-Ca alloy increased slightly with the increase of Ca content, whilst its tensile strength increased at first and then decreased. Corrosion tests in the simulated body fluid revealed that the addition of Ca is detrimental to corrosion resistance due to the micro-galvanic corrosion acceleration. In vitro hemolysis and cytotoxicity assessment disclose that Mg-5Zn-1.0Ca alloy has suitable biocompatibility.

  11. The diagnostic value of serum tumor markers CEA, CA19-9, CA125, CA15-3, and TPS in metastatic breast cancer.

    Science.gov (United States)

    Wang, Weigang; Xu, Xiaoqin; Tian, Baoguo; Wang, Yan; Du, Lili; Sun, Ting; Shi, Yanchun; Zhao, Xianwen; Jing, Jiexian

    2017-07-01

    This study aims to understand the diagnostic value of serum tumor markers carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9), cancer antigen 125 (CA125), cancer antigen 15-3 (CA15-3), and tissue polypeptide-specific antigen (TPS) in metastatic breast cancer (MBC). A total of 164 metastatic breast cancer patients in Shanxi Cancer Hospital were recruited between February 2016 and July 2016. 200 breast cancer patients without metastasis in the same period were randomly selected as the control group. The general characteristics, immunohistochemical, and pathological results were investigated between the two groups, and tumor markers were determined. There were statistical differences in the concentration and the positive rates of CEA, CA19-9, CA125, CA15-3, and TPS between the MBC and control group (Ptumor marker at 56.7% and 97.0%, respectively. In addition, two tumor markers were used for the diagnosis of MBC and the CEA and TPS combination had the highest diagnostic sensitivity with 78.7%, while the CA15-3 and CA125 combination had the highest specificity of 91.5%. Analysis of tumor markers of 164 MBC found that there were statistical differences in the positive rates of CEA and CA15-3 between bone metastases and other metastases (χ 2 =6.00, P=0.014; χ 2 =7.32, P=0.007, respectively). The sensitivity and specificity values of the CEA and CA15-3 combination in the diagnosis of bone metastases were 77.1% and 45.8%, respectively. The positive rate of TPS in the lung metastases group was lower than in other metastases (χ 2 =8.06, P=0.005).There were significant differences in the positive rates of CA15-3 and TPS between liver metastases and other metastases (χ 2 =15.42, Ptumor markers have varying diagnostic value. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. New limits on 2β processes in 40Ca and 46Ca by using low radioactive CaF2(Eu) crystal scintillators

    International Nuclear Information System (INIS)

    Belli, P.; Bernabei, R.; Dai, C.J.

    2001-01-01

    The development of highly radiopure CaF 2 (Eu) crystal scintillators has been performed aiming at a substantial sensitivity enhancement of the 2β decay investigation and of the search for dark matter particles with spin-dependent (SD) interaction. The results of CaF 2 (Eu) background measurements and simulation are presented. New and highly improved T 1/2 limits on the 2β decay of 46 Ca and the double electron capture of 40 Ca are obtained

  13. Optimization and application of ICPMS with dynamic reaction cell for precise determination of 44Ca/40Ca isotope ratios.

    Science.gov (United States)

    Boulyga, Sergei F; Klötzli, Urs; Stingeder, Gerhard; Prohaska, Thomas

    2007-10-15

    An inductively coupled plasma mass spectrometer with dynamic reaction cell (ICP-DRC-MS) was optimized for determining (44)Ca/(40)Ca isotope ratios in aqueous solutions with respect to (i) repeatability, (ii) robustness, and (iii) stability. Ammonia as reaction gas allowed both the removal of (40)Ar+ interference on (40)Ca+ and collisional damping of ion density fluctuations of an ion beam extracted from an ICP. The effect of laboratory conditions as well as ICP-DRC-MS parameters such a nebulizer gas flow rate, rf power, lens potential, dwell time, or DRC parameters on precision and mass bias was studied. Precision (calculated using the "unbiased" or "n - 1" method) of a single isotope ratio measurement of a 60 ng g(-1) calcium solution (analysis time of 6 min) is routinely achievable in the range of 0.03-0.05%, which corresponded to the standard error of the mean value (n = 6) of 0.012-0.020%. These experimentally observed RSDs were close to theoretical precision values given by counting statistics. Accuracy of measured isotope ratios was assessed by comparative measurements of the same samples by ICP-DRC-MS and thermal ionization mass spectrometry (TIMS) by using isotope dilution with a (43)Ca-(48)Ca double spike. The analysis time in both cases was 1 h per analysis (10 blocks, each 6 min). The delta(44)Ca values measured by TIMS and ICP-DRC-MS with double-spike calibration in two samples (Ca ICP standard solution and digested NIST 1486 bone meal) coincided within the obtained precision. Although the applied isotope dilution with (43)Ca-(48)Ca double-spike compensates for time-dependent deviations of mass bias and allows achieving accurate results, this approach makes it necessary to measure an additional isotope pair, reducing the overall analysis time per isotope or increasing the total analysis time. Further development of external calibration by using a bracketing method would allow a wider use of ICP-DRC-MS for routine calcium isotopic measurements, but it

  14. Impact of seawater [Ca

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G.J.; de Nooijer, L.J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  15. CaV 3.1 and CaV 3.3 account for T-type Ca2+ current in GH3 cells

    Directory of Open Access Journals (Sweden)

    M.A. Mudado

    2004-06-01

    Full Text Available T-type Ca2+ channels are important for cell signaling by a variety of cells. We report here the electrophysiological and molecular characteristics of the whole-cell Ca2+ current in GH3 clonal pituitary cells. The current inactivation at 0 mV was described by a single exponential function with a time constant of 18.32 ± 1.87 ms (N = 16. The I-V relationship measured with Ca2+ as a charge carrier was shifted to the left when we applied a conditioning pre-pulse of up to -120 mV, indicating that a low voltage-activated current may be present in GH3 cells. Transient currents were first activated at -50 mV and peaked around -20 mV. The half-maximal voltage activation and the slope factors for the two conditions are -35.02 ± 2.4 and 6.7 ± 0.3 mV (pre-pulse of -120 mV, N = 15, and -27.0 ± 0.97 and 7.5 ± 0.7 mV (pre-pulse of -40 mV, N = 9. The 8-mV shift in the activation mid-point was statistically significant (P < 0.05. The tail currents decayed bi-exponentially suggesting two different T-type Ca2+ channel populations. RT-PCR revealed the presence of a1G (CaV3.1 and a1I (CaV3.3 T-type Ca2+ channel mRNA transcripts.

  16. Tetanic Ca2+ transient differences between slow- and fast-twitch mouse skeletal muscle fibres: a comprehensive experimental approach.

    Science.gov (United States)

    Calderón, Juan C; Bolaños, Pura; Caputo, Carlo

    2014-12-01

    One hundred and eighty six enzymatically dissociated murine muscle fibres were loaded with Mag-Fluo-4 AM, and adhered to laminin, to evaluate the effect of modulating cytosolic Ca(2+) buffers and sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA), mitochondria, and Na(+)/Ca(2+) exchanger (NCX) on the differential tetanic Ca(2+) transient kinetics found in different fibre types. Tetanic Ca(2+) transients were classified as morphology type I (MT-I) or type II (MT-II) according to their shape. The first peak of the MT-I (n = 25) and MT-II (n = 23) tetanic Ca(2+) transients had an amplitude (∆F/F) of 0.41 ± 0.03 and 0.83 ± 0.05 and a rise time (ms) of 1.35 and 0.98, respectively. MT-I signals had a time constant of decay (τ1, ms) of 75.9 ± 4.2 while MT-II transients showed a double exponential decay with time constants of decay (τ1 and τ2, ms) of 18.3 ± 1.4 and 742.2 ± 130.3. Sarcoendoplasmic reticulum Ca(2+) ATPase inhibition demonstrated that the decay phase of the tetanic transients mostly rely on SERCA function. Adding Ca(2+) chelators in the AM form to MT-I fibres changed the morphology of the initial five peaks to a MT-II one, modifying the decay phase of the signal in a dose-dependent manner. Mitochondria and NCX function have a minor role in explaining differences in tetanic Ca(2+) transients among fibre types but still help in removing Ca(2+) from the cytosol in both MT-I and MT-II fibres. Cytoplasmic Ca(2+) buffering capacity and SERCA function explain most of the different kinetics found in tetanic Ca(2+) transients from different fibre types, but mitochondria and NCX have a measurable role in shaping tetanic Ca(2+) responses in both slow and fast-twitch muscle fibre types. We provided experimental evidence on the mechanisms that help understand the kinetics of tetanic Ca(2+) transients themselves and explain kinetic differences found among fibre types.

  17. Coupled Ca2+/H+ transport by cytoplasmic buffers regulates local Ca2+ and H+ ion signaling.

    Science.gov (United States)

    Swietach, Pawel; Youm, Jae-Boum; Saegusa, Noriko; Leem, Chae-Hun; Spitzer, Kenneth W; Vaughan-Jones, Richard D

    2013-05-28

    Ca(2+) signaling regulates cell function. This is subject to modulation by H(+) ions that are universal end-products of metabolism. Due to slow diffusion and common buffers, changes in cytoplasmic [Ca(2+)] ([Ca(2+)]i) or [H(+)] ([H(+)]i) can become compartmentalized, leading potentially to complex spatial Ca(2+)/H(+) coupling. This was studied by fluorescence imaging of cardiac myocytes. An increase in [H(+)]i, produced by superfusion of acetate (salt of membrane-permeant weak acid), evoked a [Ca(2+)]i rise, independent of sarcolemmal Ca(2+) influx or release from mitochondria, sarcoplasmic reticulum, or acidic stores. Photolytic H(+) uncaging from 2-nitrobenzaldehyde also raised [Ca(2+)]i, and the yield was reduced following inhibition of glycolysis or mitochondrial respiration. H(+) uncaging into buffer mixtures in vitro demonstrated that Ca(2+) unloading from proteins, histidyl dipeptides (HDPs; e.g., carnosine), and ATP can underlie the H(+)-evoked [Ca(2+)]i rise. Raising [H(+)]i tonically at one end of a myocyte evoked a local [Ca(2+)]i rise in the acidic microdomain, which did not dissipate. The result is consistent with uphill Ca(2+) transport into the acidic zone via Ca(2+)/H(+) exchange on diffusible HDPs and ATP molecules, energized by the [H(+)]i gradient. Ca(2+) recruitment to a localized acid microdomain was greatly reduced during intracellular Mg(2+) overload or by ATP depletion, maneuvers that reduce the Ca(2+)-carrying capacity of HDPs. Cytoplasmic HDPs and ATP underlie spatial Ca(2+)/H(+) coupling in the cardiac myocyte by providing ion exchange and transport on common buffer sites. Given the abundance of cellular HDPs and ATP, spatial Ca(2+)/H(+) coupling is likely to be of general importance in cell signaling.

  18. Polyamines mediate abnormal Ca2+ transport and Ca2+-induced cardiac cell injury in the calcium paradox

    International Nuclear Information System (INIS)

    Trout, J.J.; Koenig, H.; Goldstone, A.D.; Lu, C.Y.; Fan, C.C.

    1986-01-01

    Ca 2+ -free perfusion renders heart cells Ca 2+ -sensitive so that readmission of Ca 2+ causes a sudden massive cellular injury attributed to abnormal entry of Ca 2+ into cells (Ca paradox). Hormonal stimulation of Ca 2+ fluxes was earlier shown to be mediated by polyamines (PA). 5 min perfusion of rat heart with Ca 2+ -free medium induce a prompt 40-50% decline in levels of the PA putrescine (PUT), spermidine and spermine and their rate-regulatory synthetic enzyme ornithine decarboxylase (ODC), and readmission of Ca 2+ -containing medium abruptly ( 2+ reperfusion-induced increases in ODC and PA and also prevented increased 45 Ca 2+ uptake and heart injury, manifested by loss of contractility, release of enzymes (CPK, LDH), myoglobin and protein, and E.M. lesions (contracture bands, mitochondrial changes). 1 mM PUT negated DFMO inhibition, repleted heart PA and restored Ca 2+ reperfusion-induced 45 Ca 2+ influx and cell injury. These data indicate that the Ca 2+ -directed depletion-repletion cycle of ODC and PA triggers excessive transsarcolemmal Ca 2+ transport leading to the calcium paradox

  19. Far-infrared radiation acutely increases nitric oxide production by increasing Ca2+ mobilization and Ca2+/calmodulin-dependent protein kinase II-mediated phosphorylation of endothelial nitric oxide synthase at serine 1179

    International Nuclear Information System (INIS)

    Park, Jung-Hyun; Lee, Sangmi; Cho, Du-Hyong; Park, Young Mi; Kang, Duk-Hee; Jo, Inho

    2013-01-01

    Highlights: •Far-infrared (FIR) radiation increases eNOS-Ser 1179 phosphorylation and NO production in BAEC. •CaMKII and PKA mediate FIR-stimulated increases in eNOS-Ser 1179 phosphorylation. •FIR increases intracellular Ca 2+ levels. •Thermo-sensitive TRPV Ca 2+ channels are unlikely to be involved in the FIR-mediated eNOS-Ser 1179 phosphorylation pathway. -- Abstract: Repeated thermal therapy manifested by far-infrared (FIR) radiation improves vascular function in both patients and mouse model with coronary heart disease, but its underlying mechanism is not fully understood. Using FIR as a thermal therapy agent, we investigate the molecular mechanism of its effect on endothelial nitric oxide synthase (eNOS) activity and NO production. FIR increased the phosphorylation of eNOS at serine 1179 (eNOS-Ser 1179 ) in a time-dependent manner (up to 40 min of FIR radiation) in bovine aortic endothelial cells (BAEC) without alterations in eNOS expression. This increase was accompanied by increases in NO production and intracellular Ca 2+ levels. Treatment with KN-93, a selective inhibitor of Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) and H-89, a protein kinase A inhibitor, inhibited FIR radiation-stimulated eNOS-Ser 1179 phosphorylation. FIR radiation itself also increased the temperature of culture medium. As transient receptors potential vanilloid (TRPV) ion channels are known to be temperature-sensitive calcium channels, we explore whether TRPV channels mediate these observed effects. Reverse transcription-PCR assay revealed two TRPV isoforms in BAEC, TRPV2 and TRPV4. Although ruthenium red, a pan-TRPV inhibitor, completely reversed the observed effect of FIR radiation, a partial attenuation (∼20%) was found in cells treated with Tranilast, TRPV2 inhibitor. However, ectopic expression of siRNA of TRPV2 showed no significant alteration in FIR radiation-stimulated eNOS-Ser 1179 phosphorylation. This study suggests that FIR radiation increases NO

  20. Intracellular alkalinization induces cytosolic Ca2+ increases by inhibiting sarco/endoplasmic reticulum Ca2+-ATPase (SERCA.

    Directory of Open Access Journals (Sweden)

    Sen Li

    Full Text Available Intracellular pH (pHi and Ca(2+ regulate essentially all aspects of cellular activities. Their inter-relationship has not been mechanistically explored. In this study, we used bases and acetic acid to manipulate the pHi. We found that transient pHi rise induced by both organic and inorganic bases, but not acidification induced by acid, produced elevation of cytosolic Ca(2+. The sources of the Ca(2+ increase are from the endoplasmic reticulum (ER Ca(2+ pools as well as from Ca(2+ influx. The store-mobilization component of the Ca(2+ increase induced by the pHi rise was not sensitive to antagonists for either IP(3-receptors or ryanodine receptors, but was due to inhibition of the sarco/endoplasmic reticulum Ca(2+-ATPase (SERCA, leading to depletion of the ER Ca(2+ store. We further showed that the physiological consequence of depletion of the ER Ca(2+ store by pHi rise is the activation of store-operated channels (SOCs of Orai1 and Stim1, leading to increased Ca(2+ influx. Taken together, our results indicate that intracellular alkalinization inhibits SERCA activity, similar to thapsigargin, thereby resulting in Ca(2+ leak from ER pools followed by Ca(2+ influx via SOCs.

  1. Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

    Science.gov (United States)

    Joint EPA and Los Angeles Regional Water Quality Control Board NPDES Permit and Waiver from Secondary Treatment for the West Basin Municipal Water District Edward C. Little Water Recycling Plant, El Segundo, CA: CA0063401

  2. Large conductance Ca2+-activated K+ (BK channel: Activation by Ca2+ and voltage

    Directory of Open Access Journals (Sweden)

    RAMÓN LATORRE

    2006-01-01

    Full Text Available Large conductance Ca2+-activated K+ (BK channels belong to the S4 superfamily of K+ channels that include voltage-dependent K+ (Kv channels characterized by having six (S1-S6 transmembrane domains and a positively charged S4 domain. As Kv channels, BK channels contain a S4 domain, but they have an extra (S0 transmembrane domain that leads to an external NH2-terminus. The BK channel is activated by internal Ca2+, and using chimeric channels and mutagenesis, three distinct Ca2+-dependent regulatory mechanisms with different divalent cation selectivity have been identified in its large COOH-terminus. Two of these putative Ca2+-binding domains activate the BK channel when cytoplasmic Ca2+ reaches micromolar concentrations, and a low Ca2+ affinity mechanism may be involved in the physiological regulation by Mg2+. The presence in the BK channel of multiple Ca2+-binding sites explains the huge Ca2+ concentration range (0.1 μM-100 μM in which the divalent cation influences channel gating. BK channels are also voltage-dependent, and all the experimental evidence points toward the S4 domain as the domain in charge of sensing the voltage. Calcium can open BK channels when all the voltage sensors are in their resting configuration, and voltage is able to activate channels in the complete absence of Ca2+. Therefore, Ca2+ and voltage act independently to enhance channel opening, and this behavior can be explained using a two-tiered allosteric gating mechanism.

  3. Influence of ER leak on resting cytoplasmic Ca2+ and receptor-mediated Ca2+ signalling in human macrophage.

    Science.gov (United States)

    Layhadi, Janice A; Fountain, Samuel J

    2017-06-03

    Mechanisms controlling endoplasmic reticulum (ER) Ca 2+ homeostasis are important regulators of resting cytoplasmic Ca 2+ concentration ([Ca 2+ ] cyto ) and receptor-mediated Ca 2+ signalling. Here we investigate channels responsible for ER Ca 2+ leak in THP-1 macrophage and human primary macrophage. In the absence of extracellular Ca 2+ we employ ionomycin action at the plasma membrane to stimulate ER Ca 2+ leak. Under these conditions ionomycin elevates [Ca 2+ ] cyto revealing a Ca 2+ leak response which is abolished by thapsigargin. IP 3 receptors (Xestospongin C, 2-APB), ryanodine receptors (dantrolene), and translocon (anisomycin) inhibition facilitated ER Ca 2+ leak in model macrophage, with translocon inhibition also reducing resting [Ca 2+ ] cyto . In primary macrophage, translocon inhibition blocks Ca 2+ leak but does not influence resting [Ca 2+ ] cyto . We identify a role for translocon-mediated ER Ca 2+ leak in receptor-mediated Ca 2+ signalling in both model and primary human macrophage, whereby the Ca 2+ response to ADP (P2Y receptor agonist) is augmented following anisomycin treatment. In conclusion, we demonstrate a role of ER Ca 2+ leak via the translocon in controlling resting cytoplasmic Ca 2+ in model macrophage and receptor-mediated Ca 2+ signalling in model macrophage and primary macrophage. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Spectroscopic, Elemental and Thermal Analysis, and Positron Annihilation Studies on Ca(II), Sr(II), Ba(II), Pb(II), and Fe(III) Penicillin G Potassium Complexes

    Science.gov (United States)

    Refat, M. S.; Sharshara, T.

    2015-11-01

    The [Pb(Pin)2] · 3H2O, [M(Pin)(H2O)2(Cl)] · nH2O (M = SrII, CaII or BaII; n = 0-1), and [Fe(Pin)2(Cl)(H2O)] · H2O penicillin G potassium (Pin) complexes were synthesized and characterized using elemental analyses, molar conductivity, thermal analysis and electronic spectroscopy techniques. The positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques have been employed to probe the defects and structural changes of Pin ligand and its complexes. The PAL and DB line-shape parameters were discussed in terms of the structure, molecular weight, ligand-metal molar ratio, and other properties of the Pin complexes.

  5. Combined Evaluation of AFP, CA15-3, CA125, CA19-9, and CEA Tumor Markers in Patients with Hepatitis B and C.

    Science.gov (United States)

    Assmar, Mehdi; Yeganeh, Sara; Mansourghanaei, Fariborz; Amirmozafari, Nour

    2016-12-01

    This study aimed to determine the role of tumor markers AFP, CA15-3, CA125, CA19-9 and CEA in patients with hepatitis B and C. This descriptive cross-sectional study was performed from Oct 2012 to Oct 2014. Serum samples of 129 patients with hepatitis B and C referred to Guilan Liver and Digestive Disease Research Center in Rasht, Iran were collected and checked for the existence of the listed tumor markers by ELISA. No increase in serum levels of tumor marker CA19-9, CEA and CA15-3 were seen in patients with hepatitis ( P >0.05). In patients with hepatitis B, increase in CA125 were observed ( P =0.03). In hepatitis C patients, there was an increase in AFP levels ( P =0.03). The levels of AFP and CA125 markers were high in hepatitis C and hepatitis B, respectively. However, the increased levels were not seen is malignancy. Due to the small sample size, further study is necessary to find the reasons of the increase.

  6. Phase diagrams for systems Cu2S-AIIS (AII=Mg, Ca, Sr, Ba)

    International Nuclear Information System (INIS)

    Andreev, O.V.; Sikerina, N.V.; Solov'eva, A.V.

    2005-01-01

    By the methods of physicochemical analysis phase diagrams of Cu 2 S-A II S (A II =Mg, Ca, Sr, Ba) systems are studied. The system Cu 2 S-SrS is of eutectic type with eutectic coordinates 1095 K and 21.5 mol.% of SrS. Solubility of SrS in Cu 2 S is 2 mol.% at 1095 K. Regularities of phase diagram changes of Cu 2 S-A II S (A II =Mg, Ca, Sr, Ba) system are determined. Thermodynamic analysis is done [ru

  7. Prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma

    Science.gov (United States)

    Wang, Wei; Chen, Xiao-Long; Zhao, Shen-Yu; Xu, Yu-Hui; Zhang, Wei-Han; Liu, Kai; Chen, Xin-Zu; Yang, Kun; Zhang, Bo; Chen, Zhi-Xin; Chen, Jia-Ping; Zhou, Zong-Guang; Hu, Jian-Kun

    2016-01-01

    The prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma (GC) has been widely reported and is still under debate. Here, we evaluated the prognostic significance of preoperative serum CA125, CA19-9 and CEA in patients with GC. 1692 patients with GC who underwent gastrectomy were divided into the training (from January 2005 to December 2011, n = 1024) and the validation (from January 2012 to December 2013, n = 668) cohorts. Positive groups of CA125 (> 13.72 U/ml), CA19-9 (> 23.36 U/ml) and CEA (> 4.28 ng/ml) were significantly associated with more advanced clinicopathological traits and worse outcomes than that of negative groups (all P tumor size (P tumor markers (NPTM) were more accurate in prognostic prediction than TNM stage alone. Our findings suggested that elevated preoperative serum CA125, CA19-9 and CEA were associated with more advanced clinicopathological traits and less favorable outcomes. In addition, CA125 as an independent prognostic factor should be further investigated. Nomogram based on NPTM could accurately predict the prognosis of GC patients. PMID:27097114

  8. Nuclear spectroscopy of Ca and Sc isotopes from inelastic scattering and one-nucleon transfer reactions on a radioactive 41Ca target

    International Nuclear Information System (INIS)

    Vold, P.

    1978-04-01

    The structure of energy levels in 40 , 42 Ca and 42 Sc has been studied using inelastic proton scattering and one-nucleon stripping and pick-up transfer reactions on a 41 Ca target. Data has given the following information on the properties of the 41 Ca ground state wave function; i) the 41 Ca (g.s.) looks very much like an f (sub7/2) neutron coupled to the 40 Ca (g.s.) core. ii) The core-excited component of the 41 Ca (g.s.) is determined to be 10 or less. It was inferred that the main constituents of the spectroscopic strength leading to the (f(sub7/2)) 2 , (f(sub7/2)p(sub3/2))(subt=1) and (f(sub7/2)p(sub1/2))(subT=1) configurations have been identified. This was used to deduce the effective two-particle matrix elements for these configurations. The 42 Sc and 42 Ca data result in excellent agreement for the T=1 members of the (f(sub7/2)) 2 multiplet while the (f(sub7/2)p(sub3/2))(subT=1) matrix elements derived from the 42 Sc data are about 0.2 MeV more repulsive than those obtained from the 42 Ca data. The (f(sub7/2)d(sub3/2) -1 ) matrix elements derived from the present ( 3 He,α) data were compared to the corresponding values obtained from one-nucleon stripping to mass 34 nuclei. The two sets of matrix elements are in very good agreement. The 40 Ca values are also well reproduced by calculations using the modified surface delta interaction. The experimental spectroscopic factors to both the T=0 and T=1 states of the (f(sub7/2)) 2 multiplet are in remarkably good agreement with the predicted values of the coexistence model considering the simplicity of this model. (JIW)

  9. Impact parameter determination for 40Ca + 40Ca reactions using a neural network

    International Nuclear Information System (INIS)

    Haddad, F.; Hagel, K.; Li, J.; Mdeiwayeh, N.; Natowitz, J.B.; Wada, R.; Xiao, B.; David, C.; Freslier, M.; Aichelin, J.

    1995-01-01

    A neural network is used for the impact parameter determination in 40 Ca + 40 Ca reactions at energies between 35 and 70 AMeV. A special attention is devoted to the effect of experimental constraints such as the detection efficiency. An overall improvement of the impact parameter determination of 25% is obtained with the neural network. The neural network technique is then used in the analysis of the Ca+Ca data at 35 AMeV and allows separation of three different class of events among the selected 'complete' events. (authors). 8 refs., 5 figs

  10. Diabetes increases mortality after myocardial infarction by oxidizing CaMKII

    OpenAIRE

    Luo, Min; Guan, Xiaoqun; Luczak, Elizabeth D.; Lang, Di; Kutschke, William; Gao, Zhan; Yang, Jinying; Glynn, Patric; Sossalla, Samuel; Swaminathan, Paari D.; Weiss, Robert M.; Yang, Baoli; Rokita, Adam G.; Maier, Lars S.; Efimov, Igor R.

    2013-01-01

    Diabetes increases oxidant stress and doubles the risk of dying after myocardial infarction, but the mechanisms underlying increased mortality are unknown. Mice with streptozotocin-induced diabetes developed profound heart rate slowing and doubled mortality compared with controls after myocardial infarction. Oxidized Ca2+/calmodulin-dependent protein kinase II (ox-CaMKII) was significantly increased in pacemaker tissues from diabetic patients compared with that in nondiabeti...

  11. PGC-1α accelerates cytosolic Ca2+ clearance without disturbing Ca2+ homeostasis in cardiac myocytes

    International Nuclear Information System (INIS)

    Chen, Min; Wang, Yanru; Qu, Aijuan

    2010-01-01

    Energy metabolism and Ca 2+ handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1α in cardiac Ca 2+ signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1α via adenoviral transduction. Our data shows that overexpressing PGC-1α improved myocyte contractility without increasing the amplitude of Ca 2+ transients, suggesting that myofilament sensitivity to Ca 2+ increased. Interestingly, the decay kinetics of global Ca 2+ transients and Ca 2+ waves accelerated in PGC-1α-expressing cells, but the decay rate of caffeine-elicited Ca 2+ transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca 2+ -ATPase (SERCA2a), but not Na + /Ca 2+ exchange (NCX) contribute to PGC-1α-induced cytosolic Ca 2+ clearance. Furthermore, PGC-1α induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1α did not disturb cardiac Ca 2+ homeostasis, because SR Ca 2+ load and the propensity for Ca 2+ waves remained unchanged. These data suggest that PGC-1α can ameliorate cardiac Ca 2+ cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1α-calcium handing pathway sheds new light on the role of PGC-1α in the therapy of cardiac diseases.

  12. Comparison of phosgene, chlorine, and hydrogen chloride as reagents for converting molten CaO.CaCl2 to CaCl2

    International Nuclear Information System (INIS)

    Fife, K.W.

    1985-01-01

    One method at Los Alamos for preparing impure plutonium metal from the impure oxide is by batch reduction with calcium metal at 850 0 C in a CaCl 2 solvent. The solvent salt from this reduction is currently discarded as low-level radioactivity waste only because it is saturated with the CaO byproduct. We have demonstrated a pyrochemical technique for converting the CaO to CaCl 2 thereby incorporating solvent recycling into the batch reduction process. We will discuss the effectiveness of HCl, Cl 2 , and COCl 2 as chlorinating agents and recycling actual spent process solvent salts. 6 refs., 8 figs

  13. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    International Nuclear Information System (INIS)

    Souza, C.F.; Carneiro, A.B.; Silveira, A.B.; Laranja, G.A.T.; Silva-Neto, M.A.C.; Costa, S.C. Goncalves da; Paes, M.C.

    2009-01-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  14. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    Energy Technology Data Exchange (ETDEWEB)

    Souza, C.F. [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Carneiro, A.B.; Silveira, A.B. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); Laranja, G.A.T. [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); Silva-Neto, M.A.C. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); INCT, Entomologia Molecular (Brazil); Costa, S.C. Goncalves da [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Paes, M.C., E-mail: mcpaes@uerj.br [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); INCT, Entomologia Molecular (Brazil)

    2009-12-18

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  15. Regulation of Blood Pressure by Targeting CaV1.2-Galectin-1 Protein Interaction.

    Science.gov (United States)

    Hu, Zhenyu; Li, Guang; Wang, Jiong-Wei; Chong, Suet Yen; Yu, Dejie; Wang, Xiaoyuan; Soon, Jia Lin; Liang, Mui Cheng; Wong, Yuk Peng; Huang, Na; Colecraft, Henry M; Liao, Ping; Soong, Tuck Wah

    2018-04-12

    Background -L-type Ca V 1.2 channels play crucial roles in regulation of blood pressure. Galectin-1 (Gal-1), has been reported to bind to the I-II loop of Ca V 1.2 channels to reduce their current density. However, the mechanistic understanding for the down-regulation of Ca V 1.2 channels by Gal-1, and whether Gal-1 plays a direct role in blood pressure regulation remain unclear. Methods - In vitro experiments involving co-IP, western blot, patch-clamp recordings, immunohistochemistry and pressure myography were used to evaluate the molecular mechanisms by which Gal-1 down-regulates Ca V 1.2 channel in transfected HEK 293 cells, smooth muscle cells, arteries from Lgasl1 -/- mice, rat and human patients. In vivo experiments involving delivery of Tat-e9c peptide and AAV5-Gal-1 into rats were performed to investigate the effect of targeting Ca V 1.2-Gal-1 interaction on blood pressure monitored by tail cuff or telemetry methods. Results -Our study reveals that Gal-1 is a key regulator for proteasomal degradation of Ca V 1.2 channels. Gal-1 competed allosterically with Ca V β subunit for binding to the I-II loop of Ca V 1.2 channel. This competitive disruption of Ca V β binding led to Ca V 1.2 degradation by exposing the channels to poly-ubiquitination. Notably, we demonstrated that the inverse relationship of reduced Gal-1 and increased Ca V 1.2 protein levels in arteries was associated with hypertension in hypertensive rats and patients, and Gal-1 deficiency induces higher blood pressure in mice due to up-regulated Ca V 1.2 protein level in arteries. To directly regulate blood pressure by targeting the Ca V 1.2-Gal-1 interaction, we administered Tat-e9c, a peptide that competed for binding of Gal-1, by a mini-osmotic pump and this specific disruption of Ca V 1.2-Gal-1 coupling increased smooth muscle Ca V 1.2 currents, induced larger arterial contraction and caused hypertension in rats. In contrasting experiments, over-expression of Gal-1 in smooth muscle by a

  16. Ozone (O{sub 3}) elicits neurotoxicity in spinal cord neurons (SCNs) by inducing ER Ca{sup 2+} release and activating the CaMKII/MAPK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yun; Lin, Xiaowen; Zhao, XueJun; Xie, Juntian; JunNan, Wang; Sun, Tao; Fu, Zhijian, E-mail: zhijian_fu@163.com

    2014-11-01

    Ozone (O{sub 3}) is widely used in the treatment of spinal cord related diseases. Excess or accumulation of this photochemical air can however be neurotoxic. In this study, in vitro cultured Wister rat spinal cord neurons (SCNs) were used to investigate the detrimental effects and underlying mechanisms of O{sub 3}. Ozone in a dose-dependent manner inhibited cell viability at a range of 20 to 500 μg/ml, with the dose at 40 μg/ml resulting in a decrease of cell viability to 75%. The cell death after O{sub 3} exposure was related to endoplasmic reticulum (ER) calcium (Ca{sup 2+}) release. Intracellular Ca{sup 2+} chelator, ER stabilizer (inositol 1,4,5-trisphosphate receptor (IP3R) antagonist and ryanodine receptor (RyR) antagonist) and calcium/calmodulin-dependent protein kinase II (CaMKII) antagonist could effectively block Ca{sup 2+} mobilization and inhibit cell death following 40 μg/ml O{sub 3} exposure. In addition, ER Ca{sup 2+} release due to O{sub 3} exposure enhanced phospho-p38 and phospho-JNK levels and apoptosis of SCNs through activating CaMKII. Based on these results, we confirm that ozone elicits neurotoxicity in SCNs via inducing ER Ca{sup 2+} release and activating CaMKII/MAPK signaling pathway. Therefore, physicians should get attention to the selection of treatment concentrations of oxygen/ozone. And, approaches, such as chelating intracellular Ca{sup 2+} and stabilizing neuronal Ca{sup 2+} homeostasis could effectively ameliorate the neurotoxicity of O{sub 3}. - Highlights: • Exposure to O{sub 3} can reduce the viability of SCNs and cause the cell death. • Exposure to O{sub 3} can trigger RyR and IP3R dependent intracellular Ca{sup 2+} release. • Exposure to O{sub 3} can enhance the phospho-CaMKII, phospho-JNK and phospho-p38 levels.

  17. Nanosilica supported CaO: A regenerable and mechanically hard CO2 sorbent at Ca-looping conditions

    International Nuclear Information System (INIS)

    Sanchez-Jimenez, P.E.; Perez-Maqueda, L.A.; Valverde, J.M.

    2014-01-01

    Highlights: • A synthetic CO 2 sorbent is prepared by impregnation of calcium nitrate on a nanosilica matrix. • Sintering of the nascent CaO in the calcination stage of carbonation/calcination cycles is hindered. • CaO conversion reaches a stable value well above the residual conversion of natural limestone. • Particle fragmentation as caused by ultrasonic irradiation in a liquid dispersion is hindered. - Abstract: This work presents a CO 2 sorbent that may be synthesized from low-cost and widely available materials following a simple method basically consisting of impregnation of a nanostructured silica support with a saturated solution of calcium nitrate. In a first impregnation stage, the use of a stoichiometric CaO/SiO 2 ratio serves to produce a calcium silicate matrix after calcination. This calcium silicate matrix acts as a thermally stable and mechanically hard support for CaO deposited on it by further impregnation. The CaO-impregnated sorbent exhibits a stable CaO conversion at Ca-looping conditions whose value depends on the CaO wt% deposited on the calcium silicate matrix, which can be increased by successive reimpregnations. A 10 wt% CaO impregnated sorbent reaches a stable conversion above 0.6 whereas the stable conversion of a 30 wt% CaO impregnated sorbent is around 0.3, which is much larger than the residual conversion of CaO derived from natural limestone (between 0.07 and 0.08). Moreover, particle size distribution measurements of samples predispersed in a liquid and subjected to high energy ultrasonic waves indicate that the CaO-impregnated sorbent has a relatively high mechanical strength as compared to limestone derived CaO

  18. Thermoluminescence of CaCO3:Dy and CaCO3:Mn

    International Nuclear Information System (INIS)

    Bapat, V.N.; Nambi, K.S.V.

    1976-01-01

    CaCO 3 samples doped with Dy and Mn were prepared in the laboratory by co-precipitation techniques. Thermoluminescence and emission spectra of these phosphors were studied and were compared with those of the naturally occuring calcite and undoped CaCO 3 samples. Dy-doping seems to give a more efficient phosphor and indicates a possibility of getting a better phosphor by a judicious choice of a rare earth doping of CaCO 3 . Interesting result have been obtained on the TL glow curve variations of these phosphors with different temperature treatments prior to irradiation. (author)

  19. Chemical purification of CaCO{sub 3} and CaWO{sub 4} powders used for CaWO{sub 4} crystal production for the CRESST experiment

    Energy Technology Data Exchange (ETDEWEB)

    Trinh Thi, H.H.; Defay, X.; Erb, A.; Hampf, R.; Lanfranchi, J.C.; Langenkaemper, A.; Morgalyuk, V.; Muenster, A.; Mondragon, E.; Oppenheimer, C.; Potzel, W.; Schoenert, S.; Steiger, H.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Physik-Department and Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany)

    2016-07-01

    CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) uses CaWO{sub 4} single crystals as targets for the direct search for dark matter particles. Since several years these CaWO{sub 4} crystals are grown at the Technische Universitaet Muenchen. Thereby, commercially available CaCO{sub 3} and WO{sub 3} powders are used for the synthesis of CaWO{sub 4} powder. For the experiment low intrinsic contaminations of the crystals play a crucial role. In order to improve the radiopurity of the crystals it is necessary to reduce potential sources for radioactive backgrounds such as U and Th. In this poster we will present our studies of the chemical purification of the CaCO{sub 3} and CaWO{sub 4} powders.

  20. Ischemic damage in hippocampal CA1 is dependent on glutamate release and intact innervation from CA3

    DEFF Research Database (Denmark)

    Benveniste, H; Jørgensen, M B; Sandberg, M

    1989-01-01

    The removal of glutamatergic afferents to CA1 by destruction of the CA3 region is known to protect CA1 pyramidal cells against 10 min of transient global ischemia. To investigate further the pathogenetic significance of glutamate, we measured the release of glutamate in intact and CA3-lesioned CA...

  1. Ca isotopic fractionation patterns in forest ecosystems

    Science.gov (United States)

    Kurtz, A. C.; Takagi, K.

    2012-12-01

    Calcium stable isotope ratios are an emerging tracer of the biogeochemical cycle of Ca that are just beginning to see significant application to forest ecosystems. The primary source of isotopic fractionation in these systems is discrimination against light Ca during uptake by plant roots. Cycling of vegetation-fractionated Ca establishes isotopically distinct Ca pools within a forest ecosystem. In some systems, the shallow soil exchangeable Ca pool is isotopically heavy relative to Ca inputs. This has been explained by preferential removal of light Ca from the soil. In other systems, the soil exchange pool is isotopically light relative to inputs, which is explained by recycling of plant-fractionated light Ca back into soil. Thus vegetation uptake of light Ca has been called on to account for both isotopically heavy and light Ca in the shallow soil exchange pools. We interpret patterns in ecosystem δ44Ca with the aid of a simple box model of the forest Ca cycle. We suggest that the δ44Ca of exchangeable Ca in the shallow soil pool primarily reflects the relative magnitude of three key fluxes in a forest Ca cycle, 1) the flux of external Ca into the system via weathering or atmospheric deposition, 2) the uptake flux of Ca from soils into the vegetation pool, and 3) the return flux of Ca to shallow soils via remineralization of leaf litter. Two observations that emerge from our model may aid in the application of Ca isotopes to provide insight into the forest Ca cycle. First, regardless of the magnitude of both vegetation Ca uptake and isotopic fractionation, the δ44Ca of the soil exchange pool will equal the input δ44Ca unless the plant uptake and remineralization fluxes are out of balance. A second observation is that the degree to which the shallow soil exchange pool δ44Ca can differ from the input ratio is controlled by the relative rates of biological uptake and external Ca input. Significant differences between soil exchange and input δ44Ca are seen only

  2. Spin decomposition of the responses of 44Ca and 48Ca to 300 MeV protons

    International Nuclear Information System (INIS)

    Baker, F.T.; Bimbot, L.; Fergerson, R.W.; Glashausser, C.; Green, A.; Haeusser, O.; Hicks, K.; Jones, K.; Miller, C.A.; Vetterli, M.; Abegg, R.; Beatty, D.; Bonin, B.; Castel, B.; Chen, X.Y.; Cupps, V.; Djalali, C.; Henderson, R.; Jackson, K.P.; Jeppesen, R.; Nakayama, K.; Nanda, S.K.; Sawafta, R.; Yen, S.; Institut de Physique Nucleaire, F-91406 Orsay, France; Rutgers University, Piscataway, New Jersey 08854; Simon Fraser University, Burnaby, Canada V5A1S6; TRIUMF, 4004 Westbrook Mall, Vancouver, Canada V6T2A3; Los Alamos National Laboratory, Los Alamos, New Mexico 87544; Centre d'Etudes Nucleaires de Saclay, 91191 Gif sur Yvette, CEDEX, France; Queen's University, Kingston, Canada K7L3N6; University of Colorado, Boulder, Colorado 80309; University of South Carolina, Columbia, South Carolina 29208; Continuous Electron Beam Accelerator Facility, 12000 Jefferson Ave., Newport News, Virginia 23606; University of Alberta, Edmonton, Canada T6G2J1)

    1991-01-01

    Angular distributions of the double-differential cross section d 2 σ/dΩ dE(σ) and the spin-flip probability S nn have been measured for inclusive proton inelastic scattering from 44 Ca at 290 MeV and from 48 Ca at 318 MeV. Excitation energies up to about 50 MeV for 44 Ca and 40 MeV for 48 Ca have been investigated over the laboratory angular ranges of 3 degree to 12 degree for 44 Ca and 3 degree to 9 degree for 48 Ca. Multipole decompositions of angular distributions of both the spin-flip cross section σS nn and the estimated cross section for ΔS=0 transitions have been performed. Distributions of strengths were deduced for ΔL=1, ΔS=0 (the giant dipole), ΔL=2, ΔS=0 (the giant quadrupole), ΔL=0, ΔS=1 (the magnetic dipole), ΔL=1, ΔS=1 (the spin dipole), and ΔL=2, ΔS=1 (the spin quadrupole). The ΔS=0 summed strengths for 44 Ca are lower than for 40 Ca and 48 Ca. The spin-dipole summed strengths are found to be approximately independent of A. For 48 Ca, essentially all M1 strength observed was in the 10.23 MeV 1 + state; for 44 Ca, M1 strength was observed to be fragmented over a range of 7 to 18 Mev

  3. Tumor markers CA19-9, CA242 and CEA in the diagnosis of pancreatic cancer: a meta-analysis.

    Science.gov (United States)

    Zhang, Yimin; Yang, Jun; Li, Hongjuan; Wu, Yihua; Zhang, Honghe; Chen, Wenhu

    2015-01-01

    Pancreatic cancer has the worst prognosis and early detection is crucial for improving patient prognosis. Therefore, we performed a meta-analysis to evaluate and compare the sensitivity and specificity of single test of CA19-9, CA242, and CEA, as well as combination test in pancreatic cancer detection. We searched PubMed, Embase, Medline, and Wanfang databases for studies that evaluated the diagnostic validity of CA19-9, CA242, and CEA between January 1990 and September 2014. Data were analyzed by Meta-Disc and STATA software. A total of 21 studies including 3497 participants, which fulfilled the inclusion criteria were considered for analysis. The pooled sensitivities for CA19-9, CA242, and CEA were 75.4 (95% CI: 73.4-77.4), 67.8 (95% CI: 65.5-70), and 39.5 (95% CI: 37.3-41.7), respectively. The pooled specificities of CA19-9, CA242, and CEA were 77.6 (95% CI: 75.4-79.7), 83 (95% CI: 81-85), and 81.3 (95% CI: 79.3-83.2), respectively. Parallel combination of CA19-9+CA242 has a higher sensitivity (89, 95% CI: 80-95) without impairing the specificity (75, 95% CI: 67-82). Our meta-analysis showed that CA242 and CA19-9 have better performance in the diagnosis of pancreatic cancer than CEA. Furthermore, parallel combination test of CA19-9+CA242 could be of better diagnostic value than individual CA242 or CA19-9 test.

  4. Ab-initio calculations of the Ruddlesden-Popper phases CaMnO3, CaO(CaMnO3) and CaO(CaMnO3)2

    International Nuclear Information System (INIS)

    Cardoso, C; Borges, R P; Gasche, T; Godinho, M

    2008-01-01

    The present work reports ab-initio density functional theory calculations for the Ruddlesden-Popper phase CaO(CaMnO 3 ) n compounds. In order to study the evolution of the properties with the number of perovskite layers, a detailed analysis of the densities of states calculated for each compound and for several magnetic configurations was performed. The effect of distortions of the crystal structure on the magnetic ground state is also analysed and the exchange constants and transition temperatures are calculated for the three compounds using a mean field model. The calculated magnetic ground state structures and magnetic moments are in good agreement with experimental results and previous calculations

  5. Endothelial CaMKII as a regulator of eNOS activity and NO-mediated vasoreactivity.

    Directory of Open Access Journals (Sweden)

    Shubha Murthy

    Full Text Available The multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII is a serine/threonine kinase important in transducing intracellular Ca2+ signals. While in vitro data regarding the role of CaMKII in the regulation of endothelial nitric oxide synthase (eNOS are contradictory, its role in endothelial function in vivo remains unknown. Using two novel transgenic models to express CaMKII inhibitor peptides selectively in endothelium, we examined the effect of CaMKII on eNOS activation, NO production, vasomotor tone and blood pressure. Under baseline conditions, CaMKII activation was low in the aortic wall. Consistently, systolic and diastolic blood pressure, heart rate and plasma NO levels were unaltered by endothelial CaMKII inhibition. Moreover, endothelial CaMKII inhibition had no significant effect on NO-dependent vasodilation. These results were confirmed in studies of aortic rings transduced with adenovirus expressing a CaMKII inhibitor peptide. In cultured endothelial cells, bradykinin treatment produced the anticipated rapid influx of Ca2+ and transient CaMKII and eNOS activation, whereas CaMKII inhibition blocked eNOS phosphorylation on Ser-1179 and dephosphorylation at Thr-497. Ca2+/CaM binding to eNOS and resultant NO production in vitro were decreased under CaMKII inhibition. Our results demonstrate that CaMKII plays an important role in transient bradykinin-driven eNOS activation in vitro, but does not regulate NO production, vasorelaxation or blood pressure in vivo under baseline conditions.

  6. Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

    Science.gov (United States)

    Barclay, C J

    2012-12-01

    The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

  7. Measurements of natural 41Ca concentrations

    International Nuclear Information System (INIS)

    Steinhof, A.

    1989-05-01

    Atomic mass spectroscopic examinations on 41 Ca were carried out in the UNILAC accelerator. A sensitivity of about 10 -15 was achieved. This would allow the measurement of present natural 41 Ca concentrations as soon as the problem of the transmission determination is solved. In this respect suggestions were worked out and their feasibility discussed. The detection of 41 Ca-ions is especially free of background when high UNILAC-energies are applied. An estimation showed a background level corresponding with a 41 Ca concentration of less then 10 -17 referred to 40 Ca. Besides an independent concept for the electromagnetic concentration of 41 Ca with variable concentration factors was developed. After being concentrated up to 50 respectively 25 times the initial concentration in the GSI mass separator, the 41 Ca concentration of three recent deer bones found in the Odenwald was measured by atomic mass spectroscopy in the 14UD-Pelletron Tandem in Rehovot (Israel). The measured 41 Ca concentrations ranged between 10 -14 to 10 -13 with consideration of the concentration factor. A theoretical study of the 41 Ca production in the earth's surface based on cosmic radiation illustrates the influence of trace elements on the neutron flux and thus on the 41 Ca production. This influence might be a possible explanation for the observed amplitude of variation of the 41 Ca concentration in recent bones which are of decisive importance for the feasibility of 41 Ca-related dating. In this work a method is suggested that does not depend on the amplitude of variation mentioned above and which would allow the determination of the erosion rate of rocks by its 41 Ca concentrations. (orig./HP) [de

  8. Bax regulates neuronal Ca2+ homeostasis.

    Science.gov (United States)

    D'Orsi, Beatrice; Kilbride, Seán M; Chen, Gang; Perez Alvarez, Sergio; Bonner, Helena P; Pfeiffer, Shona; Plesnila, Nikolaus; Engel, Tobias; Henshall, David C; Düssmann, Heiko; Prehn, Jochen H M

    2015-01-28

    Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation. Copyright © 2015 the authors 0270-6474/15/351706-17$15.00/0.

  9. Structural basis for the differential effects of CaBP1 and calmodulin on CaV1.2 calcium-dependent inactivation

    Science.gov (United States)

    Findeisen, Felix; Minor, Daniel L.

    2010-01-01

    Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (CaVs) with unusual properties. CaBP1 inhibits CaV1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation (CDF). Here, we show that the ability of CaBP1 to inhibit CaV1.2 CDI and induce CDF arises from interaction between the CaBP1 N-lobe and interlobe linker residue Glu94. Unlike CaM, where functional EF hands are essential for channel modulation, CDI inhibition does not require functional CaBP1 EF-hands. Furthermore, CaBP1-mediated CDF has different molecular requirements than CaM-mediated CDF. Overall, the data show that CaBP1 comprises two structural modules having separate functions: similar to CaM, the CaBP1 C-lobe serves as a high-affinity anchor that binds the CaV1.2 IQ domain at a site that overlaps with the Ca2+/CaM C-lobe site, whereas the N-lobe/linker module houses the elements required for channel modulation. Discovery of this division provides the framework for understanding how CaBP1 regulates CaVs. PMID:21134641

  10. Structural basis for the differential effects of CaBP1 and calmodulin on Ca(V)1.2 calcium-dependent inactivation.

    Science.gov (United States)

    Findeisen, Felix; Minor, Daniel L

    2010-12-08

    Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (Ca(V)s) with unusual properties. CaBP1 inhibits Ca(V)1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation (CDF). Here, we show that the ability of CaBP1 to inhibit Ca(V)1.2 CDI and induce CDF arises from interaction between the CaBP1 N-lobe and interlobe linker residue Glu94. Unlike CaM, where functional EF hands are essential for channel modulation, CDI inhibition does not require functional CaBP1 EF hands. Furthermore, CaBP1-mediated CDF has different molecular requirements than CaM-mediated CDF. Overall, the data show that CaBP1 comprises two structural modules having separate functions: similar to CaM, the CaBP1 C-lobe serves as a high-affinity anchor that binds the Ca(V)1.2 IQ domain at a site that overlaps with the Ca²+/CaM C-lobe site, whereas the N-lobe/linker module houses the elements required for channel modulation. Discovery of this division provides the framework for understanding how CaBP1 regulates Ca(V)s. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. CORRELATION OF 48Ca, 50Ti, AND 138La HETEROGENEITY IN THE ALLENDE REFRACTORY INCLUSIONS

    International Nuclear Information System (INIS)

    Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Chen, Jiang-Chang

    2015-01-01

    Precise determinations of 48 Ca anomalies in Allende calcium–aluminum-rich inclusions (CAIs) are reported in this work. There are endemic positive 48 Ca/ 44 Ca anomalies in all analyzed CAIs after normalization to 42 Ca/ 44 Ca, and it is clearly shown that there is no simple correlation between 48 Ca/ 44 Ca and 50 Ti/ 48 Ti anomalies, in agreement with Jungck et al. Compared to the 48 Ca/ 44 Ca versus 50 Ti/ 48 Ti correlation line defined by differentiated meteorites, reported by Chen et al., the CAIs plot to elevated 50 Ti/ 48 Ti. Assuming the 48 Ca/ 44 Ca anomalies of both CAIs and differentiated meteorites came from the same source, excess 50 Ti anomalies in CAIs can be calculated by subtracting the part associated with 48 Ca/ 44 Ca. These excesses show a linear correlation with 138 La anomalies, a neutrino-process nuclide. According to current stellar nucleosynthetic models, we therefore suggest that the solar system 48 Ca, 50 Ti, and 138 La isotopic variations are made of mixtures between grains condensed from ejecta of neutron-rich accretion-induced SNe Ia and the O/Ne–O/C zone of core-collapse SNe II

  12. Far-infrared radiation acutely increases nitric oxide production by increasing Ca{sup 2+} mobilization and Ca{sup 2+}/calmodulin-dependent protein kinase II-mediated phosphorylation of endothelial nitric oxide synthase at serine 1179

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung-Hyun; Lee, Sangmi [Department of Molecular Medicine and Ewha Medical Research Institute, Ewha Womans University Medical School, Seoul 158-710 (Korea, Republic of); Cho, Du-Hyong [Department of Neuroscience, School of Medicine, Konkuk University, Seoul 143-701 (Korea, Republic of); Park, Young Mi [Department of Molecular Medicine and Ewha Medical Research Institute, Ewha Womans University Medical School, Seoul 158-710 (Korea, Republic of); Kang, Duk-Hee [Division of Nephrology, Department of Internal Medicine, Ewha Womans University Medical School, Seoul 158-710 (Korea, Republic of); Jo, Inho, E-mail: inhojo@ewha.ac.kr [Department of Molecular Medicine and Ewha Medical Research Institute, Ewha Womans University Medical School, Seoul 158-710 (Korea, Republic of)

    2013-07-12

    Highlights: •Far-infrared (FIR) radiation increases eNOS-Ser{sup 1179} phosphorylation and NO production in BAEC. •CaMKII and PKA mediate FIR-stimulated increases in eNOS-Ser{sup 1179} phosphorylation. •FIR increases intracellular Ca{sup 2+} levels. •Thermo-sensitive TRPV Ca{sup 2+} channels are unlikely to be involved in the FIR-mediated eNOS-Ser{sup 1179} phosphorylation pathway. -- Abstract: Repeated thermal therapy manifested by far-infrared (FIR) radiation improves vascular function in both patients and mouse model with coronary heart disease, but its underlying mechanism is not fully understood. Using FIR as a thermal therapy agent, we investigate the molecular mechanism of its effect on endothelial nitric oxide synthase (eNOS) activity and NO production. FIR increased the phosphorylation of eNOS at serine 1179 (eNOS-Ser{sup 1179}) in a time-dependent manner (up to 40 min of FIR radiation) in bovine aortic endothelial cells (BAEC) without alterations in eNOS expression. This increase was accompanied by increases in NO production and intracellular Ca{sup 2+} levels. Treatment with KN-93, a selective inhibitor of Ca{sup 2+}/calmodulin-dependent protein kinase II (CaMKII) and H-89, a protein kinase A inhibitor, inhibited FIR radiation-stimulated eNOS-Ser{sup 1179} phosphorylation. FIR radiation itself also increased the temperature of culture medium. As transient receptors potential vanilloid (TRPV) ion channels are known to be temperature-sensitive calcium channels, we explore whether TRPV channels mediate these observed effects. Reverse transcription-PCR assay revealed two TRPV isoforms in BAEC, TRPV2 and TRPV4. Although ruthenium red, a pan-TRPV inhibitor, completely reversed the observed effect of FIR radiation, a partial attenuation (∼20%) was found in cells treated with Tranilast, TRPV2 inhibitor. However, ectopic expression of siRNA of TRPV2 showed no significant alteration in FIR radiation-stimulated eNOS-Ser{sup 1179} phosphorylation. This

  13. Angiotensin-2-mediated Ca2+ signaling in the retinal pigment epithelium: role of angiotensin-receptor-associated-protein and TRPV2 channel.

    Directory of Open Access Journals (Sweden)

    Rene Barro-Soria

    Full Text Available Angiotensin II (AngII receptor (ATR is involved in pathologic local events such as neovascularisation and inflammation including in the brain and retina. The retinal pigment epithelium (RPE expresses ATR in its AT1R form, angiotensin-receptor-associated protein (Atrap, and transient-receptor-potential channel-V2 (TRPV2. AT1R and Atrap co-localize to the basolateral membrane of the RPE, as shown by immunostaining. Stimulation of porcine RPE (pRPE cells by AngII results in biphasic increases in intracellular free Ca(2+inhibited by losartan. Xestospongin C (xest C and U-73122, blockers of IP3R and PLC respectively, reduced AngII-evoked Ca(2+response. RPE cells from Atrap(-/- mice showed smaller AngII-evoked Ca(2+peak (by 22% and loss of sustained Ca(2+elevation compared to wild-type. The TRPV channel activator cannabidiol (CBD at 15 µM stimulates intracellular Ca(2+-rise suggesting that porcine RPE cells express TRPV2 channels. Further evidence supporting the functional expression of TRPV2 channels comes from experiments in which 100 µM SKF96365 (a TRPV channel inhibitor reduced the cannabidiol-induced Ca(2+-rise. Application of SKF96365 or reduction of TRPV2 expression by siRNA reduced the sustained phase of AngII-mediated Ca(2+transients by 53%. Thus systemic AngII, an effector of the local renin-angiotensin system stimulates biphasic Ca(2+transients in the RPE by releasing Ca(2+from cytosolic IP3-dependent stores and activating ATR/Atrap and TRPV2 channels to generate a sustained Ca(2+elevation.

  14. Elementary properties of CaV1.3 Ca2+ channels expressed in mouse cochlear inner hair cells

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Lawrence, Neil D; Münkner, Stefan; Engel, Jutta; Knipper, Marlies; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2010-01-01

    Mammalian cochlear inner hair cells (IHCs) are specialized to process developmental signals during immature stages and sound stimuli in adult animals. These signals are conveyed onto auditory afferent nerve fibres. Neurotransmitter release at IHC ribbon synapses is controlled by L-type CaV1.3 Ca2+ channels, the biophysics of which are still unknown in native mammalian cells. We have investigated the localization and elementary properties of Ca2+ channels in immature mouse IHCs under near-physiological recording conditions. CaV1.3 Ca2+ channels at the cell pre-synaptic site co-localize with about half of the total number of ribbons present in immature IHCs. These channels activated at about −70 mV, showed a relatively short first latency and weak inactivation, which would allow IHCs to generate and accurately encode spontaneous Ca2+ action potential activity characteristic of these immature cells. The CaV1.3 Ca2+ channels showed a very low open probability (about 0.15 at −20 mV: near the peak of an action potential). Comparison of elementary and macroscopic Ca2+ currents indicated that very few Ca2+ channels are associated with each docked vesicle at IHC ribbon synapses. Finally, we found that the open probability of Ca2+ channels, but not their opening time, was voltage dependent. This finding provides a possible correlation between presynaptic Ca2+ channel properties and the characteristic frequency/amplitude of EPSCs in auditory afferent fibres. PMID:19917569

  15. Elementary properties of CaV1.3 Ca(2+) channels expressed in mouse cochlear inner hair cells.

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Lawrence, Neil D; Münkner, Stefan; Engel, Jutta; Knipper, Marlies; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2010-01-01

    Mammalian cochlear inner hair cells (IHCs) are specialized to process developmental signals during immature stages and sound stimuli in adult animals. These signals are conveyed onto auditory afferent nerve fibres. Neurotransmitter release at IHC ribbon synapses is controlled by L-type Ca(V)1.3 Ca(2+) channels, the biophysics of which are still unknown in native mammalian cells. We have investigated the localization and elementary properties of Ca(2+) channels in immature mouse IHCs under near-physiological recording conditions. Ca(V)1.3 Ca(2+) channels at the cell pre-synaptic site co-localize with about half of the total number of ribbons present in immature IHCs. These channels activated at about 70 mV, showed a relatively short first latency and weak inactivation, which would allow IHCs to generate and accurately encode spontaneous Ca(2+) action potential activity characteristic of these immature cells. The Ca(V)1.3 Ca(2+) channels showed a very low open probability (about 0.15 at 20 mV: near the peak of an action potential). Comparison of elementary and macroscopic Ca(2+) currents indicated that very few Ca(2+) channels are associated with each docked vesicle at IHC ribbon synapses. Finally, we found that the open probability of Ca(2+) channels, but not their opening time, was voltage dependent. This finding provides a possible correlation between presynaptic Ca(2+) channel properties and the characteristic frequency/amplitude of EPSCs in auditory afferent fibres.

  16. Transverse Oscillations in Slender Ca ii H Fibrils Observed with Sunrise/SuFI

    Energy Technology Data Exchange (ETDEWEB)

    Jafarzadeh, S. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Solanki, S. K.; Gafeira, R.; Noort, M. van; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L. [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Iniesta, J. C. del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apartado de Correos 3004, E-18080 Granada (Spain); Knölker, M. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Schmidt, W., E-mail: shahin.jafarzadeh@astro.uio.no [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany)

    2017-03-01

    We present observations of transverse oscillations in slender Ca ii H fibrils (SCFs) in the lower solar chromosphere. We use a 1 hr long time series of high- (spatial and temporal-) resolution seeing-free observations in a 1.1 Å wide passband covering the line core of Ca ii H 3969 Å from the second flight of the Sunrise balloon-borne solar observatory. The entire field of view, spanning the polarity inversion line of an active region close to the solar disk center, is covered with bright, thin, and very dynamic fine structures. Our analysis reveals the prevalence of transverse waves in SCFs with median amplitudes and periods on the order of 2.4 ± 0.8 km s{sup −1} and 83 ± 29 s, respectively (with standard deviations given as uncertainties). We find that the transverse waves often propagate along (parts of) the SCFs with median phase speeds of 9 ± 14 km s{sup −1}. While the propagation is only in one direction along the axis in some of the SCFs, propagating waves in both directions, as well as standing waves are also observed. The transverse oscillations are likely Alfvénic and are thought to be representative of magnetohydrodynamic kink waves. The wave propagation suggests that the rapid high-frequency transverse waves, often produced in the lower photosphere, can penetrate into the chromosphere with an estimated energy flux of ≈15 kW m{sup −2}. Characteristics of these waves differ from those reported for other fibrillar structures, which, however, were observed mainly in the upper solar chromosphere.

  17. Curcumin Attenuates Opioid Tolerance and Dependence by Inhibiting Ca2+/Calmodulin-Dependent Protein Kinase II α Activity

    Science.gov (United States)

    Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena

    2015-01-01

    Chronic use of opioid analgesics has been hindered by the development of opioid addiction and tolerance. We have reported that curcumin, a natural flavonoid from the rhizome of Curcuma longa, attenuated opioid tolerance, although the underlying mechanism remains unclear. In this study, we tested the hypothesis that curcumin may inhibit Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein kinase that has been previously proposed to be critical for opioid tolerance and dependence. In this study, we used state-of-the-art polymeric formulation technology to produce poly(lactic-co-glycolic acid) (PLGA)-curcumin nanoparticles (nanocurcumin) to overcome the drug’s poor solubility and bioavailability, which has made it extremely difficult for studying in vivo pharmacological actions of curcumin. We found that PLGA-curcumin nanoparticles reduced the dose requirement by 11- to 33-fold. Pretreatment with PLGA-curcumin (by mouth) prevented the development of opioid tolerance and dependence in a dose-dependent manner, with ED50 values of 3.9 and 3.2 mg/kg, respectively. PLGA-curcumin dose-dependently attenuated already-established opioid tolerance (ED50 = 12.6 mg/kg p.o.) and dependence (ED50 = 3.1 mg/kg p.o.). Curcumin or PLGA-curcumin did not produce antinociception by itself or affect morphine (1–10 mg/kg) antinociception. Moreover, we found that the behavioral effects of curcumin on opioid tolerance and dependence correlated with its inhibition of morphine-induced CaMKIIα activation in the brain. These results suggest that curcumin may attenuate opioid tolerance and dependence by suppressing CaMKIIα activity. PMID:25515789

  18. Electronic structures and magnetism of CaFeAsH and CaFeAsF

    International Nuclear Information System (INIS)

    Wang Guangtao; Shi Xianbiao; Liu Haipeng; Liu Qingbo

    2015-01-01

    We studied the electronic structures, magnetism, and Fermi surface (FS) nesting of CaFeAsH and CaFeAsF by first-principles calculations. In the nonmagnetic (NM) states, we found strong FS nesting, which induces magnetic instability and a spin density wave (SDW). Our calculations indicate that the ground state of CaFeAsH and CaFeAsF is the stripe antiferromagnetic state. The calculated bare susceptibility χ 0 (q) peaked at the M-point and was clearly suppressed and became slightly incommensurate with both electron doping and hole doping for both materials. (author)

  19. Ca 3d unoccupied states in Bi2Sr2CaCu2O8 investigated by Ca L2,3 x-ray-absorption near-edge structure

    International Nuclear Information System (INIS)

    Borg, A.; King, P.L.; Pianetta, P.; Lindau, I.; Mitzi, D.B.; Kapitulnik, A.; Soldatov, A.V.; Della Longa, S.; Bianconi, A.

    1992-01-01

    The high-resolution Ca L 2,3 x-ray-absorption near-edge-structure (XANES) spectrum of a Bi 2 Sr 2 CaCu 2 O 8 single crystal has been measured by use of a magnetic-projection x-ray microscope probing a surface area of 200x200 μm 2 . The Ca L 2,3 XANES spectrum is analyzed by performing a multiple-scattering XANES calculation in real space and comparing the results with the spectrum of CaF 2 . Good agreement between the calculated and experimental crystal-field splitting Δ f of the Ca 3d final states is found and the splitting is shown to be smaller by 0.5 eV than in the initial state. The Ca 3d partial density of states is found to be close to the Fermi level in the initial state. The Ca-O(in plane) distance is shown to be a critical parameter associated with the shift of the Ca 3d states relative to the Fermi level; in particular, we have studied the effect of the out-of-plane dimpling mode of the in-plane oxygen atoms O(in plane) that will move the Ca 3d states on or off the Fermi level. This mode can therefore play a role in modulating the charge transfer between the two CuO 2 planes separated by the Ca ions

  20. Ca 3d unoccupied states in Bi2Sr2CaCu2O8 investigated by Ca L2,3 x-ray-absorption near-edge structure

    Energy Technology Data Exchange (ETDEWEB)

    Borg, A; King, P L; Pianetta, P; Lindau, I; Mitzi, D B

    1992-01-01

    The high-resolution Ca L(2,3) x-ray-absorption near-edge-structure (XANES) spectrum of a Bi2Sr2CaCu2O8 single crystal has been measured by use of a magnetic-projection x-ray microscope probing a surface area of 200x200 micrometers square. The Ca L(2,3) XANES spectrum is analyzed by performing a multiple-scattering XANES calculation in real space and comparing the results with the spectrum of CaF2. Good agreement between the calculated and experimental crystal-field splitting Delta f of the Ca 3d final states is found and the splitting is shown to be smaller by 0.5 eV than in the initial state. The Ca 3d partial density of states is found to be close to the Fermi level in the initial state. The Ca-O (in plane) distance is shown to be a critical parameter associated with the shift of the Ca 3d states relative to the Fermi level; in particular, the authors have studied the effect of the out-of-plane dimpling mode of the in-plane oxygen atoms O(in plane) that will move the Ca 3d states on or off the Fermi level. This mode can therefore play a role in modulating the charge transfer between the two CuO2 planes separated by the Ca ions.

  1. Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models

    Science.gov (United States)

    Mejía, Luz María; Paytan, Adina; Eisenhauer, Anton; Böhm, Florian; Kolevica, Ana; Bolton, Clara; Méndez-Vicente, Ana; Abrevaya, Lorena; Isensee, Kirsten; Stoll, Heather

    2018-01-01

    Coccoliths comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri-Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ 44 / 40 Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation-desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation-desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation-desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested.

  2. Variations of brightness and Ca 2 emission of the xi Boo AB and HD 1835 dWarf G stars

    Energy Technology Data Exchange (ETDEWEB)

    Chuganov, P.F.

    1983-01-01

    75 photoelectric UBV-observations of xi Boo AB were obtained during 45 nights in 1980. Real light variations of several thousandths of magnitude are revealed. Moreover, the variations observed in two nights were resembling flares. Both recent and published data on HD 1835 together with Wilson's observations of H and K Ca II lines in the spectra of xi Boo A, xi Boo B and HD 1835 are used for the search of periodicities. The periodicities are present in variations of light and Ca II -emission. Periodicities are more prominent in light variations (periods are 10 days for xi Boo AB and 7.66 days for HD 1835). In H and K Ca II lines the duration of cycles is different but the basic period is the same as in light variations. Therefore, the basic period (interpreted as the period of star roration) can be revealed only from a very long run of H and K Ca II observations (approximately 150). Light variations of xi Boo AB are probably due to the A-component since the basic period of Ca II-variations in xi Boo A is approximately the same (10 days). The basic period of Ca II-variations in xi Boo B is considerably larger.

  3. Variations of brightness and Ca 2 emission of the xi Boo AB and HD 1835 dWarf G stars

    International Nuclear Information System (INIS)

    Chuganov, P.F.

    1983-01-01

    75 photoelectric UBV-observations of xi Boo AB were obtained during 45 nights in 1980. Real light variations of several thousandths of magnitude are revealed. Moreover, the variations observed in two nights were resembling flares. Both recent and published data on HD 1835 together with Wilson's observations of H and K Ca II lines in the spectra of xi Boo A, xi Boo B and HD 1835 are used for the search of periodicities. The periodicities are present in variations of light and Ca II -emission. Periodicities are more prominent in light variations (periods are 10 days for xi Boo AB and 7.66 days for HD 1835). In H and K Ca II lines the dura-- tion of cycles is different but the basic period is the same as in light variations. Therefore, the basic period (interpreted as the period of star roration) can be revealed only from a very long run of H and K Ca II observations (approximately 150). Light variations of xi Boo AB are probably due to the A-component since the basic period of Ca II-variations in xi Boo A is approximately the same (10 days). The basic period of Ca II-variations in xi Boo B is considerably larger;

  4. In-situ thermal analysis and macroscopical characterization of Mg-xCa and Mg-0.5Ca-xZn alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Bakhsheshi-Rad, Hamid Reza, E-mail: Rezabakhsheshi@gmail.com [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Idris, Mohd Hasbullah [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implants Technology Group, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Department of Biomechanics and Biomedical Materials, Faculty of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Lotfabadi, Amir Fereidouni [Department of Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Ourdjini, Ali [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2012-01-10

    Highlights: Black-Right-Pointing-Pointer The effect of Ca and Zn addition on Mg-Ca and Mg-Ca-Zn were investigated. Black-Right-Pointing-Pointer Ca and Zn addition decreased solid fraction at coherency point. Black-Right-Pointing-Pointer T{sub N}-T{sub DCP} increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn, respectively. Black-Right-Pointing-Pointer Three reactions were detected when Zn/Ca atomic ratio less than 1.25 in Mg-Ca-Zn. Black-Right-Pointing-Pointer A new peak Mg{sub 51}Zn{sub 20} was identified in Mg-0.5Ca-9Zn in addition of other peaks. - Abstract: This research described the identification phases by thermal analysis and microscopy inspection of Mg-xCa and Mg-0.5%Ca-xZn alloys that were solidified at slow cooling rate. Analysis of cooling curve after Ca addition shows the evolution of the Mg{sub 2}Ca intermetallic phase at around 520 Degree-Sign C in addition to {alpha}-Mg phase. First derivative curves of alloys after the addition of Zn to Mg-0.5Ca alloy reveals three peaks related to {alpha}-Mg, Mg{sub 2}Ca and Ca{sub 2}Mg{sub 6}Zn{sub 3} for alloys that have Zn/Ca atomic ratio less than 1.23. The peak of Mg{sub 2}Ca reaction on the first derivative curves disappeared for alloys containing Zn/Ca ratio more than 1.23. A new peak was also observed at 330 Degree-Sign C for Mg-0.5Ca-9Zn which was identified as Mg{sub 51}Zn{sub 20}. Solid fraction at coherency point decreased with increasing Ca and Zn elements. However, coherency time and difference between the nucleation and coherency temperatures (T{sub N}-T{sub DCP}) increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn systems.

  5. Synthesis of Al₂Ca Dispersoids by Powder Metallurgy Using a Mg-Al Alloy and CaO Particles.

    Science.gov (United States)

    Fujita, Junji; Umeda, Junko; Kondoh, Katsuyoshi

    2017-06-28

    The elemental mixture of Mg-6 wt %Al-1 wt %Zn-0.3 wt %Mn (AZ61B) alloy powder and CaO particles was consolidated by an equal-channel angular bulk mechanical alloying (ECABMA) process to form a composite precursor. Subsequently, the precursor was subjected to a heat treatment to synthesize fine Al₂Ca particles via a solid-state reaction between the Mg-Al matrix and CaO additives. Scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and electron probe micro-analysis on the precursor indicated that 4.7-at % Al atoms formed a supersaturated solid solution in the α-Mg matrix. Transmission electron microscopy-EDS and X-ray diffraction analyses on the AZ61B composite precursor with 10-vol % CaO particles obtained by heat treatment confirmed that CaO additives were thermally decomposed in the Mg-Al alloy, and the solid-soluted Ca atoms diffused along the α-Mg grain boundaries. Al atoms also diffused to the grain boundaries because of attraction to the Ca atoms resulting from a strong reactivity between Al and Ca. As a result, needle-like (Mg,Al)₂Ca intermetallics were formed as intermediate precipitates in the initial reaction stage during the heat treatment. Finally, the precipitates were transformed into spherical Al₂Ca particles by the substitution of Al atoms for Mg atoms in (Mg,Al)₂Ca after a long heat treatment.

  6. Impact of seawater [Ca2+] on the calcification and calcite Mg / Ca of Amphistegina lessonii

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G. J.; de Nooijer, L. J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  7. CaWRKY22 Acts as a Positive Regulator in Pepper Response to Ralstonia Solanacearum by Constituting Networks with CaWRKY6, CaWRKY27, CaWRKY40, and CaWRKY58

    OpenAIRE

    Ansar Hussain; Xia Li; Yahong Weng; Zhiqin Liu; Muhammad Furqan Ashraf; Ali Noman; Sheng Yang; Muhammad Ifnan; Shanshan Qiu; Yingjie Yang; Deyi Guan; Shuilin He

    2018-01-01

    The WRKY web, which is comprised of a subset of WRKY transcription factors (TFs), plays a crucial role in the regulation of plant immunity, however, the mode of organization and operation of this network remains obscure, especially in non-model plants such as pepper (Capsicum annuum). Herein, CaWRKY22, a member of a subgroup of IIe WRKY proteins from pepper, was functionally characterized in pepper immunity against Ralstonia Solanacearum. CaWRKY22 was found to target the nuclei, and its trans...

  8. Studies of highly ionized atoms using internal conversion: 197Au, 57Fe; electric monopole transitions in 40Ca, 42Ca, and 44Ca

    International Nuclear Information System (INIS)

    Ulrickson, M.A.

    1975-01-01

    By using heavy-ion reactions, highly ionized electronic states of atoms may be produced. The interaction between excited nuclear levels and the surrounding atomic electrons via internal conversion allows the nucleus to be used as a probe of the electronic structure of the highly ionized atoms. Studies of such atoms were undertaken for strongly internally converted nuclear levels in 197 Au and 57 Fe. The nuclear levels were Coulomb excited by using 16 O and 32 S beams. Simultaneous measurement of the lifetime of the 77-keV state of 197 Au in both neutral gold atoms and gold atoms with mean charge +10 resulted in a measured change in the internal conversion coefficient of Δalpha/alpha equals - 1.7 +- 3.0)10 -3 . This result is consistent with calculations using a Hartree-Fock--Slater program. Measurements of the electric monopole strengths for 0 + → 0 + transitions were undertaken to determine the amount of core-deformation in calcium nuclei. The E0 strengths for the decays of the 0 + states at 5.21 MeV in 40 C, 1.84 MeV in 42 Ca, and 1.88 MeV in 44 Ca were observed. The branching ratios for the subsequent E0 pair decays were measured by observing the coincident annihilation radiation from the e + member of the pair in coincidence with protons feeding the state in the cases of 42 Ca and 44 Ca, and by observing the actual coincident e + --e - pair together with protons feeding the state in the case of 40 Ca. The resulting E0 strengths (rho less than or equal to 0.06, rho = 0.34 +- 0.03, rho = 0.30 +- 0.10 for 40 Ca, 42 Ca, and 44 Ca respectively) agree with theoretical descriptions

  9. Preparation of 45 Ca (HDEHP)n and (C8H15O2)2 samples for liquid scintillation counting, compared to 45CaCl2 results

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Los Arcos Merino, J.M.; Grau Malonda, A.

    1994-01-01

    A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethyhexanoate calcium salt, labelled with ''45 Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators, Toluene, Toluene-alcohol, Dioxane-napthalhene, Hisafe II, Ultima-Gold and Instagel, and compared to results obtained from a commercial solution of ''45 CaCl 2

  10. THE HANLE AND ZEEMAN POLARIZATION SIGNALS OF THE SOLAR Ca II 8542 Å LINE

    Energy Technology Data Exchange (ETDEWEB)

    Štěpán, Jiri [Astronomical Institute ASCR, Fričova 298, 251 65 Ondřejov (Czech Republic); Bueno, Javier Trujillo [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2016-07-20

    We highlight the main results of a three-dimensional (3D) multilevel radiative transfer investigation about the solar disk-center polarization of the Ca ii 8542 Å line. First, through the use of a 3D model of the solar atmosphere, we investigate the linear polarization that occurs due to the atomic level polarization produced by the absorption and scattering of anisotropic radiation, taking into account the symmetry-breaking effects caused by its thermal, dynamic, and magnetic structure. Second, we study the contribution of the Zeeman effect to the linear and circular polarization. Finally, we show examples of the Stokes profiles produced by the joint action of the atomic level polarization and the Hanle and Zeeman effects. We find that the Zeeman effect tends to dominate the linear polarization signals only in the localized patches of opposite magnetic polarity, where the magnetic field is relatively strong and slightly inclined; outside such very localized patches, the linear polarization is often dominated by the contribution of atomic level polarization. We demonstrate that a correct modeling of this last contribution requires taking into account the symmetry-breaking effects caused by the thermal, dynamic, and magnetic structure of the solar atmosphere, and that in the 3D model used the Hanle effect in forward-scattering geometry (disk-center observation) mainly reduces the polarization corresponding to the zero-field case. We emphasize that, in general, a reliable modeling of the linear polarization in the Ca ii 8542 Å line requires taking into account the joint action of atomic level polarization and the Hanle and Zeeman effects.

  11. Structural and compositional characterization of synthetic (Ca,Sr)-tremolite and (Ca,Sr)-diopside solid solutions

    Science.gov (United States)

    Gottschalk, M.; Najorka, J.; Andrut, M.

    Tremolite (CaxSr1-x)2Mg5[Si8O22/(OH)2] and diopside (CaxSr1-x)Mg[Si2O6] solid solutions have been synthesized hydrothermally in equilibrium with a 1 molar (Ca,Sr)Cl2 aqueous solution at 750°C and 200 MPa. The solid run products have been investigated by optical, electron scanning and high resolution transmission electron microscopy, electron microprobe, X-ray-powder diffraction and Fourier-transform infrared spectroscopy. The synthesized (Ca,Sr)-tremolites are up to 2000 µm long and 30 µm wide, the (Ca,Sr)-diopsides are up to 150 µm long and 20 µm wide. In most runs the tremolites and diopsides are well ordered and chain multiplicity faults are rare. Nearly pure Sr-tremolite (tr0.02Sr-tr0.98) and Sr-diopside (di0.01Sr-di0.99) have been synthesized. A continuous solid solution series, i.e. complete substitution of Sr2+ for Ca2+ on M4-sites exists for (Ca,Sr)-tremolite. Total substitution of Sr2+ for Ca2+ on M2-sites can be assumed for (Ca,Sr)-diopsides. For (Ca,Sr)-tremolites the lattice parameters a, b and β are linear functions of composition and increase with Sr-content whereas c is constant. For the diopside series all 4 lattice parameters are a linear function of composition; a, b, c increase and β decreases with rising Sr-content. The unit cell volume for tremolite increases 3.47% from 906.68 Å3 for tremolite to 938.21 Å3 for Sr-tremolite. For diopside the unit cell volume increases 4.87 % from 439.91 Å3 for diopside to 461.30 Å3 for Sr-diopside. The observed splitting of the OH stretching band in tremolite is caused by different configurations of the next nearest neighbors (multi mode behavior). Resolved single bands can be attributed to the following configurations on the M4-sites: SrSr, SrCa, CaCa and CaMg. The peak positions of these 4 absorption bands are a linear function of composition. They are shifted to lower wavenumbers with increasing Sr-content. No absorption band due to the SrMg configuration on the M4-site is observed. This indicates

  12. Formation of CaB6 in the thermal decomposition of the hydrogen storage material Ca(BH4)2.

    Science.gov (United States)

    Sahle, Christoph J; Sternemann, Christian; Giacobbe, Carlotta; Yan, Yigang; Weis, Christopher; Harder, Manuel; Forov, Yury; Spiekermann, Georg; Tolan, Metin; Krisch, Michael; Remhof, Arndt

    2016-07-20

    Using a combination of high resolution X-ray powder diffraction and X-ray Raman scattering spectroscopy at the B K- and Ca L2,3-edges, we analyzed the reaction products of Ca(BH4)2 after annealing at 350 °C and 400 °C under vacuum conditions. We observed the formation of nanocrystalline/amorphous CaB6 mainly and found only small contributions from amorphous B for annealing times larger than 2 h. For short annealing times of 0.5 h at 400 °C we observed neither CaB12H12 nor CaB6. The results indicate a reaction pathway in which Ca(BH4)2 decomposes to B and CaH2 and finally reacts to form CaB6. These findings confirm the potential of using Ca(BH4)2 as a hydrogen storage medium and imply the desired cycling capabilities for achieving high-density hydrogen storage materials.

  13. Ca2+/Calmodulin-Dependent Protein Kinase Kinases (CaMKKs) Effects on AMP-Activated Protein Kinase (AMPK) Regulation of Chicken Sperm Functions.

    Science.gov (United States)

    Nguyen, Thi Mong Diep; Combarnous, Yves; Praud, Christophe; Duittoz, Anne; Blesbois, Elisabeth

    2016-01-01

    Sperm require high levels of energy to ensure motility and acrosome reaction (AR) accomplishment. The AMP-activated protein kinase (AMPK) has been demonstrated to be strongly involved in the control of these properties. We address here the question of the potential role of calcium mobilization on AMPK activation and function in chicken sperm through the Ca(2+)/calmodulin-dependent protein kinase kinases (CaMKKs) mediated pathway. The presence of CaMKKs and their substrates CaMKI and CaMKIV was evaluated by western-blotting and indirect immunofluorescence. Sperm were incubated in presence or absence of extracellular Ca(2+), or of CaMKKs inhibitor (STO-609). Phosphorylations of AMPK, CaMKI, and CaMKIV, as well as sperm functions were evaluated. We demonstrate the presence of both CaMKKs (α and β), CaMKI and CaMKIV in chicken sperm. CaMKKα and CaMKI were localized in the acrosome, the midpiece, and at much lower fluorescence in the flagellum, whereas CaMKKβ was mostly localized in the flagellum and much less in the midpiece and the acrosome. CaMKIV was only present in the flagellum. The presence of extracellular calcium induced an increase in kinases phosphorylation and sperm activity. STO-609 reduced AMPK phosphorylation in the presence of extracellular Ca(2+) but not in its absence. STO-609 did not affect CaMKIV phosphorylation but decreased CaMKI phosphorylation and this inhibition was quicker in the presence of extracellular Ca(2+) than in its absence. STO-609 efficiently inhibited sperm motility and AR, both in the presence and absence of extracellular Ca(2+). Our results show for the first time the presence of CaMKKs (α and β) and one of its substrate, CaMKI in different subcellular compartments in germ cells, as well as the changes in the AMPK regulation pathway, sperm motility and AR related to Ca(2+) entry in sperm through the Ca(2+)/CaM/CaMKKs/CaMKI pathway. The Ca(2+)/CaMKKs/AMPK pathway is activated only under conditions of extracellular Ca(2+) entry

  14. Ca2+/Calmodulin-Dependent Protein Kinase Kinases (CaMKKs Effects on AMP-Activated Protein Kinase (AMPK Regulation of Chicken Sperm Functions.

    Directory of Open Access Journals (Sweden)

    Thi Mong Diep Nguyen

    Full Text Available Sperm require high levels of energy to ensure motility and acrosome reaction (AR accomplishment. The AMP-activated protein kinase (AMPK has been demonstrated to be strongly involved in the control of these properties. We address here the question of the potential role of calcium mobilization on AMPK activation and function in chicken sperm through the Ca(2+/calmodulin-dependent protein kinase kinases (CaMKKs mediated pathway. The presence of CaMKKs and their substrates CaMKI and CaMKIV was evaluated by western-blotting and indirect immunofluorescence. Sperm were incubated in presence or absence of extracellular Ca(2+, or of CaMKKs inhibitor (STO-609. Phosphorylations of AMPK, CaMKI, and CaMKIV, as well as sperm functions were evaluated. We demonstrate the presence of both CaMKKs (α and β, CaMKI and CaMKIV in chicken sperm. CaMKKα and CaMKI were localized in the acrosome, the midpiece, and at much lower fluorescence in the flagellum, whereas CaMKKβ was mostly localized in the flagellum and much less in the midpiece and the acrosome. CaMKIV was only present in the flagellum. The presence of extracellular calcium induced an increase in kinases phosphorylation and sperm activity. STO-609 reduced AMPK phosphorylation in the presence of extracellular Ca(2+ but not in its absence. STO-609 did not affect CaMKIV phosphorylation but decreased CaMKI phosphorylation and this inhibition was quicker in the presence of extracellular Ca(2+ than in its absence. STO-609 efficiently inhibited sperm motility and AR, both in the presence and absence of extracellular Ca(2+. Our results show for the first time the presence of CaMKKs (α and β and one of its substrate, CaMKI in different subcellular compartments in germ cells, as well as the changes in the AMPK regulation pathway, sperm motility and AR related to Ca(2+ entry in sperm through the Ca(2+/CaM/CaMKKs/CaMKI pathway. The Ca(2+/CaMKKs/AMPK pathway is activated only under conditions of extracellular Ca(2

  15. Dynamic immobilization of simulated radionuclide 133Cs in soil by thermal treatment/vitrification with nanometallic Ca/CaO composites

    International Nuclear Information System (INIS)

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Simion, Cristian; Lee, Byeong Kyu

    2015-01-01

    Although direct radiation induced health impacts were considered benign, soil contamination with 137 Cs, due to its long-term radiological impact (30 years half-life) and its high biological availability is of a major concern in Japan in the aftermath of the Fukushima nuclear power plant disaster. Therefore 137 Cs reduction and immobilization in contaminated soil are recognized as important problems to be solved using suitable and effective technologies. One such thermal treatment/vitrification with nanometallic Ca/CaO amendments is a promising treatment for the ultimate immobilization of simulated radionuclide 133 Cs in soil, showing low leachability and zero evaporation. Immobilization efficiencies were 88%, 95% and 96% when the 133 Cs soil was treated at 1200 °C with activated carbon, fly ash and nanometallic Ca/CaO additives. In addition, the combination of nanometallic Ca/CaO and fly ash (1:1) enhanced the immobilization efficiency to 99%, while no evaporation of 133 Cs was observed. At lower temperatures (800 °C) the leachable fraction of Cs was only 6% (94% immobilization). Through the SEM–EDS analysis, decrease in the amount of Cs mass percent detectable on soil particle surface was observed after soil vitrified with nCa/CaO + FA. The 133 Cs soil was subjected to vitrified with nCa/CaO + FA peaks related to Ca, crystalline phases (CaCO 3 /Ca(OH) 2 ), wollastonite, pollucite and hematite appeared in addition to quartz, kaolinite and bentonite, which probably indicates that the main fraction of enclosed/bound materials includes Ca-associated complexes. Thus, the thermal treatment with the addition of nanometallic Ca/CaO and fly ash may be considered potentially applicable for the remediation of radioactive Cs contaminated soil at zero evaporation, relatively at low temperature. - Graphical abstract: SEM–EDS element maps of 133 Cs contaminated soil before and after thermal treatment at 1200 °C with different addictives. Color intensity for Cs is from 0

  16. Anti-tumor activity of self-charged (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles

    International Nuclear Information System (INIS)

    Lin, Cao; Cong, Wang; De'An, Pan; Jiexin, Cao; Ping, Che; Volinsky, Alex A.

    2012-01-01

    Non-stoichiometric (Eu,Ca):WO 3 and Eu:CaWO 4 nanoparticles with anti-tumor activity are synthesized in a sol-gel method by adding excessive Eu 3+ and Ca 2+ ions to tungsten oxide crystal structure. Colorimetric assay shows that 10 nm (Eu,Ca):WO 3 and Eu:CaWO 4 nanoparticles can effectively inhibit growth of mammary cancer cells without any harm to normal cells. Nanoparticles are characterized by X-ray diffraction, high resolution transmission electron microscopy and fluorescence optical spectrometry. Nanomaterials, insoluble in synthesized water, have complicated self-charging surfaces that trap mammary cancer cells. Surface self-charging effect is suggested as the inhibition mechanism. (author)

  17. PGC-1{alpha} accelerates cytosolic Ca{sup 2+} clearance without disturbing Ca{sup 2+} homeostasis in cardiac myocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Min, E-mail: chenminyx@gmail.com [Institute of Molecular Medicine, State Key Laboratory of Biomembrane and Membrane Biotechnology, Peking University, Beijing 100871 (China); Yunnan Centers for Diseases Prevention and Control, Kunming 650022 (China); Wang, Yanru [Institute of Molecular Medicine, State Key Laboratory of Biomembrane and Membrane Biotechnology, Peking University, Beijing 100871 (China); Qu, Aijuan [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2010-06-11

    Energy metabolism and Ca{sup 2+} handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1{alpha}) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1{alpha} in cardiac Ca{sup 2+} signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1{alpha} via adenoviral transduction. Our data shows that overexpressing PGC-1{alpha} improved myocyte contractility without increasing the amplitude of Ca{sup 2+} transients, suggesting that myofilament sensitivity to Ca{sup 2+} increased. Interestingly, the decay kinetics of global Ca{sup 2+} transients and Ca{sup 2+} waves accelerated in PGC-1{alpha}-expressing cells, but the decay rate of caffeine-elicited Ca{sup 2+} transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca{sup 2+}-ATPase (SERCA2a), but not Na{sup +}/Ca{sup 2+} exchange (NCX) contribute to PGC-1{alpha}-induced cytosolic Ca{sup 2+} clearance. Furthermore, PGC-1{alpha} induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1{alpha} did not disturb cardiac Ca{sup 2+} homeostasis, because SR Ca{sup 2+} load and the propensity for Ca{sup 2+} waves remained unchanged. These data suggest that PGC-1{alpha} can ameliorate cardiac Ca{sup 2+} cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1{alpha}-calcium handing pathway sheds new light on the role of PGC-1{alpha} in the therapy of cardiac diseases.

  18. A critical comparison of the current view of Ca signaling with the novel concept of F-actin-based Ca signaling.

    Science.gov (United States)

    Lange, Klaus; Gartzke, Joachim

    2006-01-01

    A detailed comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect - the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating vesicles derived from the endoplasmic/ sarcoplasmic reticulum, which are equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive Ca-release channels/receptors. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of F-actin subunits. Several prominent features of Ca signaling, which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. F-actin is the only known biological Ca-binding system that has been proven by in vitro experiments to work within the physiological range of Ca concentrations and the only system that meets all necessary conditions to function as receptor-operated Ca store and as a coupling device between the Ca store and the store-operated Ca influx pathway. The most important properties of Ca signaling, such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release, turn out to be systematic features of the new concept but remain unexplained by the classical vesicle storage hypothesis. A number of novel findings, specifically recent reports about direct effects of actin-specific toxins on Ca stores, have strengthened the new concept. The concept of F-actin-based Ca signaling combined with the notion of microvillar regulation of ion and substrate fluxes opens new aspects and far-reaching consequences, not only for cellular Ca signaling but also for various other cell functions, and represents an opportunity to connect several fields of cell physiology on the basis of a common mechanism.

  19. Study on Ca2+ antagonistic effect and mechanism of Chinese herbal drugs using 45Ca

    International Nuclear Information System (INIS)

    Yang Yuanyou; Liu Ning; Mo Shangwu; Qiu Mingfeng; Jin Jiannan; Liao Jiali

    2002-01-01

    The Ca 2+ antagonistic effect and mechanism of Chinese herbal drugs are studied by using 45 Ca. The results indicate that potential-dependent Ca 2+ channel (PDC) and receptor-operated Ca 2+ channel (ROC) in cell membranes of smooth muscle can be blocked by several Chinese herbal drugs, including as Crocus sativus L., Carthamus L., Di-ao-xin-xue-kang (DAXXG) and Ginkgo biloba L. leaves. Among them Crocus sativus L. has the strongest antagonistic effect on Ca 2+ channel, while Ginkgo biloba L. leaves has no obvious effect. The whole prescription and the other functional drugs have significant effect on ROC and PDC. The compositions extracted by hexane have the strongest antagonistic. The wrinkled giant hyssop have five active compositions and Pei-lan have two active compositions

  20. OVX1, macrophage-colony stimulating factor, and CA-125-II as tumor markers for epithelial ovarian carcinoma - A critical appraisal

    NARCIS (Netherlands)

    van Haaften-Day, C; Shen, Y; Xu, FJ; Yu, YH; Berchuck, A; Havrilesky, LJ; de Bruijn, HWA; van der Zee, AGJ; Bast, RC; Hacker, NF

    2001-01-01

    BACKGROUND. Ovarian carcinoma remains the leading cause of death from gynecologic malignancy in Australia, the Netherlands, and the United States. CA-125-II, the most widely used serum marker, has limited sensitivity and specificity for detecting small-volume, early-stage disease. Therefore, a panel

  1. Mg/Ca of Continental Ostracode Shells

    Science.gov (United States)

    Ito, E.; Forester, R. M.; Marco-Barba, J.; Mezquita, F.

    2007-12-01

    Marine ionic chemistry is thought to remain constant. This, together with the belief that marine calcifiers partition Mg/Ca in a systematic manner as functions of temperature (and Mg/Ca) of water forms the basis of the Mg/Ca thermometer. In continental settings both of these assumptions are usually not true. Continental waters contain a wide variety of solutes in absolute and relative ion concentrations. Hence, waters with identical Mg/Ca may have very different concentrations of Mg and Ca and very different anions. Here we use two examples to focus on the effects of ion chemistry on Mg/Ca partitioning in continental ostracode shells and we ignore the complexities of solute evolution, which can change Mg/Ca over timescales of minutes to millennia. Palacios-Fest and Dettman (2001) conducted a monthly study of ,Cypridopsis vidua at El Yeso Lake in Sonora, Mexico. They established a relation between temperature and average shell Mg/Ca using regression analyses on averaged data. When their Mg/Ca-temperature relation is applied to monthly ,C. vidua data from Page Pond near Cleveland, Ohio, water temperatures of -8 to -1°C are obtained. The observed Mg/Ca ranges for El Yeso Lake (0.31 to 0.46) and Page Pond (0.33 to 0.46) are similar, as are their specific conductivities (700 to 850μS for El Yeso Lake; 400 to 600μS for Page Pond). However, [Ca] is 140-260 mg/L for El Yeso, but only 70-90 mg/L for Page Pond. Page Pond data, in fact, shows a good temperature shell Mg/Ca relation for .C. vidua, but the relation is different from that at El Yeso. Hence, shell Mg/Ca is a multi-valued, family of curves function of temperature and Mg/Ca of water that depends on the [Mg] and [Ca] values in water and perhaps other factors. Our second example comes from sites near Valencia, Spain and involves shell data for ,Cyprideis torosa, an estuarine ostracode that is tolerant of a wide range of salinity and can live in continental waters as long as the carbonate alkalinity to Ca ratio is

  2. Is otolith microchemistry (Sr: Ca and Ba:Ca ratios useful to identify Mugil curema populations in the southeastern Caribbean Sea?

    Directory of Open Access Journals (Sweden)

    E. Avigliano

    Full Text Available Abstract The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela. The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method. Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State were significantly different from ratios in La Guardia (north of the State. A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area.

  3. Is otolith microchemistry (Sr: Ca and Ba:Ca ratios) useful to identify Mugil curema populations in the southeastern Caribbean Sea?

    Science.gov (United States)

    Avigliano, E; Callicó-Fortunato, R; Buitrago, J; Volpedo, A V

    2015-11-01

    The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios) to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela). The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method). Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State) were significantly different from ratios in La Guardia (north of the State). A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area.

  4. Menstrual Cycle Dependent Variability for Serum Tumor Markers CEA, AFP, CA 19-9, CA 125 and CA 15-3 in Healthy Women

    Directory of Open Access Journals (Sweden)

    Ayşe Binnur Erbağci

    1999-01-01

    Full Text Available Information on menstrual cycle dependent variation of tumor markers in healthy women is a subject of diagnostic efficiency and has an impact in elucidating the normal function of these markers. In this study midfollicular and midluteal concentrations of serum CEA, AFP, CA 19-9, CA 125, CA 15-3 and their relations with LH, FSH, prolactin, estradiol and progesterone were evaluated during ovulatory cycles in a group of 23 healthy female individuals. Samples were collected on the 7th and 21st day of the same menstrual cycle. Tumor marker and hormone concentrations were determined with chemiluminescence or electrochemiluminescence EIA methods. A significant phase-dependent difference was observed for CA 15-3, midluteal concentrations (mean ± SEM; 26.33 ± 1.56 U/ml higher than the midfollicular (mean ± SEM; 19.27 ± 1.49 U/ml concentrations (p < 0.001. But an obvious difference for other tumor markers investigated did not exist. Significant correlations of follicular and luteal CA 125 levels with body mass index of the subjects were observed (r:0.52, p < 0.05 and r:0.57, p < 0.005, respectively.

  5. Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4: Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra.

    Science.gov (United States)

    Marashdeh, Ali; Frankcombe, Terry J

    2008-06-21

    The dehydrogenation enthalpies of Ca(AlH(4))(2), CaAlH(5), and CaH(2)+6LiBH(4) have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski's direct method. The dehydrogenation of Ca(AlH(4))(2) is exothermic, indicating a metastable hydride. Calculations for CaAlH(5) including ZPE effects indicate that it is not stable enough for a hydrogen storage system operating near ambient conditions. The destabilized combination of LiBH(4) with CaH(2) is a promising system after ZPE-corrected enthalpy calculations. The calculations confirm that including ZPE effects in the harmonic approximation for the dehydrogenation of Ca(AlH(4))(2), CaAlH(5), and CaH(2)+6LiBH(4) has a significant effect on the calculated reaction enthalpy. The contribution of ZPE to the dehydrogenation enthalpies of Ca(AlH(4))(2) and CaAlH(5) calculated by the direct method phonon analysis was compared to that calculated by the frozen-phonon method. The crystal structure of CaAlH(5) is presented in the more useful standard setting of P2(1)c symmetry and the phonon density of states of CaAlH(5), significantly different to other common complex metal hydrides, is rationalized.

  6. Low temperature synthesis of CaZrO3 nanoceramics from CaCl2–NaCl molten eutectic salt

    Directory of Open Access Journals (Sweden)

    Rahman Fazli

    2015-06-01

    Full Text Available CaZrO3 nanoceramics were successfully synthesized at 700 C using the molten salt method, and the effects of processing parameters, such as temperature, holding time, and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, Na2CO3, and nano-ZrO2 were used as starting materials. On heating, CaCl2–NaCl molten eutectic salt provided a liquid medium for the reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 600C and that, after the temperature was increased to 1,000C, the amounts of CaZrO3 in the resultant powders increased with a concomitant decrease in CaCO3and ZrO2 contents. After washing with hot distilled water, the samples heated for 3 h at 700C were single-phase CaZrO3 with 90–95 nm particle size. Furthermore, the synthesized CaZrO3 particles retained the size and morphology of the ZrO2 powders which indicated that a template mechanism dominated the formation of CaZrO3 by molten-salt method.

  7. Ablation of CaV2.1 Voltage-Gated Ca2+ Channels in Mouse Forebrain Generates Multiple Cognitive Impairments

    Science.gov (United States)

    Mallmann, Robert Theodor; Elgueta, Claudio; Sleman, Faten; Castonguay, Jan; Wilmes, Thomas; van den Maagdenberg, Arn; Klugbauer, Norbert

    2013-01-01

    Voltage-gated CaV2.1 (P/Q-type) Ca2+ channels located at the presynaptic membrane are known to control a multitude of Ca2+-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic CaV2.1 mouse models. Global CaV2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of CaV2.1 Ca2+ channels for complex behaviour in adult mice. Consequently we established a forebrain specific CaV2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of CaV2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific CaV2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional CaV2.1 knock-out model that is most suitable for analysing the in vivo functions of CaV2.1 in the adult murine forebrain. PMID:24205277

  8. SERCA mutant E309Q binds two Ca ions but adopts a catalytically incompetent conformation

    DEFF Research Database (Denmark)

    Clausen, Johannes D.; Bublitz, Maike; Arnou, Bertrand

    2013-01-01

    The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) couples ATP hydrolysis to transport of Ca2+. This directed energy transfer requires cross-talk between the two Ca2+ sites and the phosphorylation site over 50 Å distance. We have addressed the mechano-structural basis for this intramolecular...... a shift of transmembrane segment M1 into an ‘up and kinked position’. This transition is impaired in the E309Q mutant, most likely due to a lack of charge neutralization and altered hydrogen binding capacities at Ca2+ site II....

  9. Capture reactions of 40Ca and 48Ca with targets of 197Au and 208Pb

    International Nuclear Information System (INIS)

    Stokstad, R.; Chan, Y.; Chavez, E.

    1988-03-01

    The reactions of 40 Ca and 48 Ca with targets of 197 Au and 208 Pb have been measured in the region from below the interaction barrier to about twice the barrier energy. The fission-like fragments were detected in a pair of position-sensitive, multi-wire proportional counters and were identified from measurements of position and time using two-body kinematics. In the region above the barrier the cross sections for capture are less than those given by the touching condition, indicating that an /open quotes/extra push/close quotes/ is required to induce capture. The observations for 40 Ca and 48 Ca show different fissilities for the onset of the extra push and indicate that charge equilibration may be an important factor governing capture reactions. Below the barrier the cross sections show an enhancement relative to the prediction for a one dimensional barrier. The enhancements are larger for 40 Ca than for 48 Ca (for both targets) and this is in qualitative agreement with predictions based on the coupling of the relative motion to low-lying collective states. Both above and below the barrier, we find that the change in the light partner, from 48 Ca to 40 Ca, has a larger effect on the cross sections than the change from 208 Pb to 197 Au, after correction for the change in the Coulomb barrier. 16 refs., 7 figs

  10. Formation Mechanism of CaS-Bearing Inclusions and the Rolling Deformation in Al-Killed, Low-Alloy Steel with Ca Treatment

    Science.gov (United States)

    Xu, Guang; Jiang, Zhouhua; Li, Yang

    2016-08-01

    The existing form of CaS inclusion in Ca-treated, Al-killed steel during secondary refining process was investigated with scanning electron microscopy and an energy-dispersive spectrometer (EDS). The results of 12 heats industrial tests showed that CaS has two kinds of precipitation forms. One form takes place by the direct reaction of Ca and S, and the other takes place by the reaction of CaO in calcium aluminates with dissolved Al and S in liquid steel. Thermodynamic research for different precipitation modes of CaS under different temperature was carried out. In particular, CaO-Al2O3-CaS isothermal section diagrams and component activities of calcium aluminates were calculated by the thermodynamic software FactSage. By thermodynamic calculation, a precipitation-area diagram of oxide-sulfide duplex inclusion was established by fixing the sulfur content. The quantity of CaS, which was precipitated in a reaction between [Al], [S] and (CaO), can be calculated and predicted based on the precipitation-area diagram of oxide-sulfide duplex inclusion. Electron probe microanalysis and EDS were used for observing rolling deformation of different types of CaS-bearing inclusions during the rolling process. Low modification of calcium aluminates wrapped by CaS has different degrees of harm to steel in the rolling process. A thick CaS layer can prevent some fragile calcium aluminates from being crushed during the rolling process. Some oxide-sulfide duplex inclusion contains little CaS performed better deformation during the rolling process, but when CaS in oxide-sulfide duplex inclusion becomes more, it will cause the whole inclusion to lose plastic yielding ability. The plastic deformation region of CaS-bearing inclusion in a CaO-Al2O3-CaS isothermal section diagram is confirmed.

  11. Solidification and Immobilization of Heavy metals in Soil using with nano-metallic Ca/CaO Dispersion Mixture

    Directory of Open Access Journals (Sweden)

    Mallampati S. R.

    2013-04-01

    Full Text Available In the present work, the use of nano-metallic calcium (Ca and calcium oxide (CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb in soil was investigated. With simple grinding, 85-90% of heavy metals immobilization could be achieved, while it could be enhanced to 98-100% by grinding with the addition of nano-metallic Ca/CaO dispersion mixture. By SEM-EDS elemental maps as well as semi-quantitative analysis observed that the amount of As, Cd, Cr and Pb measurable on soil particle surface decreases after nano-metallic Ca/CaO treatment. The leachable heavy metals concentrations were reduced, to the concentration lower than the Japan soil elution standard regulatory threshold, i. e., < 0.01 mg/l for As, Cd and Pb and 0.05mg/l for Cr. Whereas, the effect of soil moisture and pH on heavy metals immobilization was not much influenced. The results suggest that nano-metallic Ca/CaO mixture is suitable to be used for the gentle immobilization of heavy metals contaminated soil at normal moisture conditions.

  12. Mechanical and thermal-expansion characteristics of Ca10(PO46(OH2-Ca3(PO42 composites

    Directory of Open Access Journals (Sweden)

    Ruseska G.

    2006-01-01

    Full Text Available Three types of composites consisting of Ca10(PO46(OH2 and Ca3(PO42 with composition: 75% (wt Ca10(PO46(OH2: 25%(wt Ca3(PO42; 50%(wt Ca10(PO46(OH2: 50%(wtCa3(PO42 and 25 %(wt Ca10(PO46(OH2: 75%(wt Ca3(PO42 were the subject of our investigation. Sintered compacts were in thermal equilibrium, which was proved by the absence of hysteresis effect of the dependence ΔL/L=f(T during heating /cooling in the temperature interval 20-1000-200C. Sintered compacts with the previously mentioned composition possess 26-50% higher values of the E-modulus, G-modulus and K-modulus indicating the presence of a synergism effect. Several proposed model equations for predicting the thermal expansion coefficient in dependence of the thermal and elastic properties of the constitutive phases and their volume fractions, given by: Turner, Kerner, Tummala and Friedberg, Thomas and Taya, were used for making correlations between mechanical and thermal-expansion characteristics of the Ca10(PO46(OH2 - Ca3(PO42 composites. Application of the previously mentioned model equations to all kinds of composites leads to the conclusion that the experimentally obtained results for the thermal expansion coefficient are in an excellent agreement with the theoretical calculated values on account of the volume fraction of each constitutive phase and with all applied model equations, with a coefficient of correlation from 98.16-99.86 %.

  13. Regional and interspecific variation in Sr, Ca, and Sr/Ca ratios in avian eggshells from the USA.

    Science.gov (United States)

    Mora, Miguel A; Brattin, Bryan; Baxter, Catherine; Rivers, James W

    2011-08-01

    To examine regional variation in strontium (Sr), which at high concentrations may reduce eggshell quality, increase egg breakage and reproductive failure, we analyzed Sr, and calcium (Ca) concentrations and Sr/Ca ratios in eggshells from 20 avian species from California, Texas, Idaho, Kansas, and Michigan. In addition, we included data previously reported from Arizona to expand the regional comparisons and to better establish patterns of Sr, and Sr/Ca ratios in bird species across the United States. We found Sr concentrations varied significantly among regions, among species, and among foraging guilds; this variability is strongly influenced by the Sr/Ca ratios in surface water from locations close to the region where the eggshells were collected. Sr concentrations and Sr/Ca ratios were significantly higher in bird eggshells from the Volta wildlife region in the San Joaquin Valley, California and in various locales from Arizona. Sr concentrations and Sr/Ca ratios in bird eggshells from other locations in the USA were lower than those detected in these two regions. Among foraging guilds, invertivores had the highest Sr concentrations and Sr/Ca ratios and carnivores had the lowest. In general, the Sr/Ca ratio increased strongly with increasing Sr concentrations (R(2) = 0.99, P eggshells suggesting that these values could be determined from Sr/Ca ratios in water. Eggshell thickness was poorly correlated with Sr (R(2) = 0.03) but had a significant and positive correlation with Ca and was more properly correlated by a quadratic equation (R(2) = 0.50, Thickness = 2.13 - 0.02Ca - 3.07 * 10(-5)Ca(2)). Our study provides further evidence that Sr accumulates significantly in the avian eggshell, in some regions at concentrations which could be of concern for potential negative effects on reproduction. We suggest that when assessing the effects of metals on avian reproduction in regions with high Sr deposits in rock and soil, Sr concentrations in the eggshell also should be

  14. Cannabinoids disrupt memory encoding by functionally isolating hippocampal CA1 from CA3.

    Directory of Open Access Journals (Sweden)

    Roman A Sandler

    2017-07-01

    Full Text Available Much of the research on cannabinoids (CBs has focused on their effects at the molecular and synaptic level. However, the effects of CBs on the dynamics of neural circuits remains poorly understood. This study aims to disentangle the effects of CBs on the functional dynamics of the hippocampal Schaffer collateral synapse by using data-driven nonparametric modeling. Multi-unit activity was recorded from rats doing an working memory task in control sessions and under the influence of exogenously administered tetrahydrocannabinol (THC, the primary CB found in marijuana. It was found that THC left firing rate unaltered and only slightly reduced theta oscillations. Multivariate autoregressive models, estimated from spontaneous spiking activity, were then used to describe the dynamical transformation from CA3 to CA1. They revealed that THC served to functionally isolate CA1 from CA3 by reducing feedforward excitation and theta information flow. The functional isolation was compensated by increased feedback excitation within CA1, thus leading to unaltered firing rates. Finally, both of these effects were shown to be correlated with memory impairments in the working memory task. By elucidating the circuit mechanisms of CBs, these results help close the gap in knowledge between the cellular and behavioral effects of CBs.

  15. Analysis of full disc Ca II K spectroheliograms. I. Photometric calibration and centre-to-limb variation compensation

    Science.gov (United States)

    Chatzistergos, Theodosios; Ermolli, Ilaria; Solanki, Sami K.; Krivova, Natalie A.

    2018-01-01

    Context. Historical Ca II K spectroheliograms (SHG) are unique in representing long-term variations of the solar chromospheric magnetic field. They usually suffer from numerous problems and lack photometric calibration. Thus accurate processing of these data is required to get meaningful results from their analysis. Aims: In this paper we aim at developing an automatic processing and photometric calibration method that provides precise and consistent results when applied to historical SHG. Methods: The proposed method is based on the assumption that the centre-to-limb variation of the intensity in quiet Sun regions does not vary with time. We tested the accuracy of the proposed method on various sets of synthetic images that mimic problems encountered in historical observations. We also tested our approach on a large sample of images randomly extracted from seven different SHG archives. Results: The tests carried out on the synthetic data show that the maximum relative errors of the method are generally returns images that differ from the ideal ones by returns consistent results for images from different SHG archives. Conclusions: Our tests show that the proposed method is more accurate than other methods presented in the literature. Our method can also be applied to process images from photographic archives of solar observations at other wavelengths than Ca II K.

  16. Far-infrared radiation acutely increases nitric oxide production by increasing Ca(2+) mobilization and Ca(2+)/calmodulin-dependent protein kinase II-mediated phosphorylation of endothelial nitric oxide synthase at serine 1179.

    Science.gov (United States)

    Park, Jung-Hyun; Lee, Sangmi; Cho, Du-Hyong; Park, Young Mi; Kang, Duk-Hee; Jo, Inho

    2013-07-12

    Repeated thermal therapy manifested by far-infrared (FIR) radiation improves vascular function in both patients and mouse model with coronary heart disease, but its underlying mechanism is not fully understood. Using FIR as a thermal therapy agent, we investigate the molecular mechanism of its effect on endothelial nitric oxide synthase (eNOS) activity and NO production. FIR increased the phosphorylation of eNOS at serine 1179 (eNOS-Ser(1179)) in a time-dependent manner (up to 40min of FIR radiation) in bovine aortic endothelial cells (BAEC) without alterations in eNOS expression. This increase was accompanied by increases in NO production and intracellular Ca(2+) levels. Treatment with KN-93, a selective inhibitor of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and H-89, a protein kinase A inhibitor, inhibited FIR radiation-stimulated eNOS-Ser(1179) phosphorylation. FIR radiation itself also increased the temperature of culture medium. As transient receptors potential vanilloid (TRPV) ion channels are known to be temperature-sensitive calcium channels, we explore whether TRPV channels mediate these observed effects. Reverse transcription-PCR assay revealed two TRPV isoforms in BAEC, TRPV2 and TRPV4. Although ruthenium red, a pan-TRPV inhibitor, completely reversed the observed effect of FIR radiation, a partial attenuation (∼20%) was found in cells treated with Tranilast, TRPV2 inhibitor. However, ectopic expression of siRNA of TRPV2 showed no significant alteration in FIR radiation-stimulated eNOS-Ser(1179) phosphorylation. This study suggests that FIR radiation increases NO production via increasing CaMKII-mediated eNOS-Ser(1179) phosphorylation but TRPV channels may not be involved in this pathway. Our results may provide the molecular mechanism by which FIR radiation improves endothelial function. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Evidence for a modulation of neutral trehalase activity by Ca2+ and cAMP signaling pathways in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Souza A.C.

    2002-01-01

    Full Text Available Saccharomyces cerevisiae neutral trehalase (encoded by NTH1 is regulated by cAMP-dependent protein kinase (PKA and by an endogenous modulator protein. A yeast strain with knockouts of CMK1 and CMK2 genes (cmk1cmk2 and its isogenic control (CMK1CMK2 were used to investigate the role of CaM kinase II in the in vitro activation of neutral trehalase during growth on glucose. In the exponential growth phase, cmk1cmk2 cells exhibited basal trehalase activity and an activation ratio by PKA very similar to that found in CMK1CMK2 cells. At diauxie, even though both cells presented comparable basal trehalase activities, cmk1cmk2 cells showed reduced activation by PKA and lower total trehalase activity when compared to CMK1CMK2 cells. To determine if CaM kinase II regulates NTH1 expression or is involved in post-translational modulation of neutral trehalase activity, NTH1 promoter activity was evaluated using an NTH1-lacZ reporter gene. Similar ß-galactosidase activities were found for CMK1CMK2 and cmk1cmk2 cells, ruling out the role of CaM kinase II in NTH1 expression. Thus, CaM kinase II should act in concert with PKA on the activation of the cryptic form of neutral trehalase. A model for trehalase regulation by CaM kinase II is proposed whereby the target protein for Ca2+/CaM-dependent kinase II phosphorylation is not the neutral trehalase itself. The possible identity of this target protein with the recently identified trehalase-associated protein YLR270Wp is discussed.

  18. Significance of the tumor markers CA 125 and CA 15-3 in postoperative diagnosis of ovarian and breast cancer

    International Nuclear Information System (INIS)

    Johannsen, B.; Bartel, U.; Elling, D.

    1989-01-01

    In 271 patients with ovarian carcinoma, benign ovarian tumors, breast cancer, and two control groups, serum levels of CA 125, CA 15-3, CEA and, partly, CA 19-9 were determined immunoradiometrically. According to the results of the determination of CA 125 in the follow-up of ovarian carcinoma, CA 125 represents a useful marker for early detection of recurrences, especially in cases of diffuse carcinoma dissemination. In incomplete tumor debulking, postoperative CA 125 serum levels did not prove to be helpful except that a positive level renders invasive diagnostic investigation no longer necessary. Postoperative follow-up in breast cancer early reveals distant metastases, with very high levels in patients with bone metastases. By simultaneous measurement of CA 15-3 and CEA the sensitivity could be increased from 86% (CA 15-3 only) to 93%. (author)

  19. Multiple Ca2+ sensors in secretion

    DEFF Research Database (Denmark)

    Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev

    2011-01-01

    Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...

  20. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

    Directory of Open Access Journals (Sweden)

    P. S. Freitas

    2009-07-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves Pecten maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as the influence of shell organic content and/or crystal size and orientation, the latter reflecting conditions at the shell crystal-solution interface. In the mid and innermost regions of the P. maximus shell the lack of significant small-scale variation of Mg/Ca ratios, which is consistent with growth at constant temperature, suggest a potential application as a palaeotemperature proxy. Cross-growth band element/Ca ratio profiles in the interior of bivalve shells may provide more promising palaeo-environmental tools than sampling from the outer region of bivalve shells.

  1. Origins of mass-dependent and mass-independent Ca isotope variations in meteoritic components and meteorites

    Science.gov (United States)

    Bermingham, K. R.; Gussone, N.; Mezger, K.; Krause, J.

    2018-04-01

    The Ca isotope composition of meteorites and their components may vary due to mass-dependent and/or -independent isotope effects. In order to evaluate the origin of these effects, five amoeboid olivine aggregates (AOAs), three calcium aluminum inclusions (CAIs), five chondrules (C), a dark inclusion from Allende (CV3), two dark fragments from North West Africa 753 (NWA 753; R3.9), and a whole rock sample of Orgueil (CI1) were analyzed. This is the first coupled mass-dependent and -independent Ca isotope dataset to include AOAs, a dark inclusion, and dark fragments. Where sample masses permit, Ca isotope data are reported with corresponding petrographic analyses and rare earth element (REE) relative abundance patterns. The CAIs and AOAs are enriched in light Ca isotopes (δ44/40Ca -5.32 to +0.72, where δ44/40Ca is reported relative to SRM 915a). Samples CAI 5 and AOA 1 have anomalous Group II REE patterns. These REE and δ44/40Ca data suggest that the CAI 5 and AOA 1 compositions were set via kinetic isotope fractionation during condensation and evaporation. The remaining samples show mass-dependent Ca isotope variations which cluster between δ44/40Ca +0.53 and +1.59, some of which are coupled with unfractionated REE abundance patterns. These meteoritic components likely formed through the coaccretion of the evaporative residue and condensate following Group II CAI formation or their chemical and isotopic signatures were decoupled (e.g., via nebular or parent-body alteration). The whole rock sample of Orgueil has a δ44/40Ca +0.67 ± 0.18 which is in agreement with most published data. Parent-body alteration, terrestrial alteration, and variable sampling of Ca-rich meteoritic components can have an effect on δ44/40Ca compositions in whole rock meteorites. Samples AOA 1, CAI 5, C 2, and C 4 display mass-independent 48/44Ca anomalies (ε48/44Ca +6 to +12) which are resolved from the standard composition. Other samples measured for these effects (AOA 5, CAI 1, CAI 2

  2. Clinical value of multi-tumor markers detection with (CEA, CA19-9, CA72-4) for diagnosis of gastric malignancy

    International Nuclear Information System (INIS)

    Liu Yun; Li Jiangang

    2007-01-01

    Objective: To assess the clinical value of multi-tumor markers detection with (CEA, CA19-9, CA72-4) for diagnosis of gastric malignancy. Methods: Serum CEA, CA19-9, CA72-4 contents were measured with IRMA in 228 patients with gastric malignancies, 152 patients with benign gastric disorders and 200 controls. Results: The positive rates of single marker detection were all above 70% and that of CA72-4 was the highest (84.21%), next was CA19-9 (75.43%). Three tumor markers were all negative in only 4 cases (false negative rate was 1.75% ). So combined detection of 3 tumor markers could improve the positive rate to 98.25%. With combined determination of two markers, double positive rate for different sets of combinations was: 61.84% for CA72-4 + CA19-9, 51.31% for CA72-4 + CEA and 48.24% for CEA + CA19-9. Conclusion: It was suggested that for screening, CA72-4 was the first choice in single marker detections, and CA72-4 + CA19-9 was the first choice for combined detections of two markers. For follow-up, a combination of 2 markers with highest positive rate for the specific histopathologic type (i. e. carcinoma, leiomyosarcoma or lymphosarcoma) should be used throughout the study. (authors)

  3. H and K (Ca II) emissions as observed in coronal spectrum in the July 20, 1963 solar eclipse

    International Nuclear Information System (INIS)

    Cavallini, F.; Righini, A.

    1975-01-01

    From a detailed analysis of a coronal spectrum taken from a DC-8 jet airplane during the Eclipse of 20 July, 1963 a rough model of a coronal cold region (T approximately 10 5 K) has been obtained. The model explains the presence of the abnormal H and K (Ca II) emissions and the large amount of F corona present in the spectrum. (Auth.)

  4. Tongqiao Huoxue Decoction ameliorates learning and memory defects in rats with vascular dementia by up-regulating the Ca(2+)-CaMKII-CREB pathway.

    Science.gov (United States)

    Ge, Chao-Liang; Wang, Xin-Ming; Huang, Zhao-Gang; Xia, Quan; Wang, Ning; Xu, Du-Juan

    2015-11-01

    The present study was aimed at determining the effects of Tongqiao Huoxue Decoction (TQHXD) on the Ca(2+)-CaMKII-CREB pathway and the memory and learning capacities of rats with vascular dementia (VD). The rat VD model was established by using an improved bilateral carotid artery ligation method. The Morris water maze experiment was used to evaluate the ethology of the VD rats following treatments with TQHXD at 3.01, 6.02, and 12.04 g·kg(-1) per day for 31 days. At the end of experiment, the hippocampus were harvested and analyzed. Western blotting and RT-PCR were used to measure the expression levels of calmodulin-binding protein kinase II(CaMKII), protein kinase A(PKA), cAMP-response element binding protein(CREB), and three N-methyl-D-aspartic acid receptor subunits (NR1, NR2A, and NR2B). Our results revealed that TQHXD could alleviate the loss of learning abilities and increase the memory capacity (P < 0.05 and P < 0.01 vs the model group, respectively). The treatment with 6.02 and 12.04 g·kg(-1) of TQHXD significantly up-regulated the Ca(2+)-CaMKII-CREB pathway in the hippocampus. In conclusion, TQHXD showed therapeutic effects on a bilateral carotid artery ligation-induced vascular dementia model, through the up-regulation of calcium signalling pathways. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  5. Determination of Mo- and Ca-isotope ratios in Ca100MoO4 crystal for AMoRE-I experiment

    Science.gov (United States)

    Karki, S.; Aryal, P.; Kim, H. J.; Kim, Y. D.; Park, H. K.

    2018-01-01

    The first phase of the AMoRE (Advanced Mo-based Rare process Experiment) is to search for neutrinoless double-beta decay of 100Mo with calcium molybdate (Ca100MoO4) crystals enriched in 100Mo and depleted in 48Ca using a cryogenic technique at Yangyang underground laboratory in Korea. It is important to know 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal to estimate half-life of 100Mo decays and to 2 νββ background from 48Ca. We employed the ICP-MS (Inductive Coupled Plasma Mass Spectrometer) to measure 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal. The measured results for 100Mo- and 48Ca-isotope ratios in the crystal are (94 . 6 ± 2 . 8) % and (0 . 00211 ± 0 . 00006) %, respectively, where errors are included both statistical and systematic uncertainties.

  6. The destiny of Ca(2+) released by mitochondria.

    Science.gov (United States)

    Takeuchi, Ayako; Kim, Bongju; Matsuoka, Satoshi

    2015-01-01

    Mitochondrial Ca(2+) is known to regulate diverse cellular functions, for example energy production and cell death, by modulating mitochondrial dehydrogenases, inducing production of reactive oxygen species, and opening mitochondrial permeability transition pores. In addition to the action of Ca(2+) within mitochondria, Ca(2+) released from mitochondria is also important in a variety of cellular functions. In the last 5 years, the molecules responsible for mitochondrial Ca(2+) dynamics have been identified: a mitochondrial Ca(2+) uniporter (MCU), a mitochondrial Na(+)-Ca(2+) exchanger (NCLX), and a candidate for a mitochondrial H(+)-Ca(2+) exchanger (Letm1). In this review, we focus on the mitochondrial Ca(2+) release system, and discuss its physiological and pathophysiological significance. Accumulating evidence suggests that the mitochondrial Ca(2+) release system is not only crucial in maintaining mitochondrial Ca(2+) homeostasis but also participates in the Ca(2+) crosstalk between mitochondria and the plasma membrane and between mitochondria and the endoplasmic/sarcoplasmic reticulum.

  7. I. The properties of hot Ca-like fragments from the 40Ca+40Ca reaction at 35 AMeV

    International Nuclear Information System (INIS)

    Planeta, R.; Gawlikowicz, W.; Wieloch, A.

    2001-01-01

    The creation of hot Ca-like fragments was investigated in the 40 Ca + 40 Ca reaction at 35 AMeV. Using the AMPHORA 4π detector system, the primary projectile-like fragment was reconstructed and its properties were determined. Both primary and secondary distributions are compared with the predictions of a Monte Carlo code describing a heavy-ion collision as a two-step process. Some of the nucleons which are identified as participants in the first step are transferred in the second step to these final states, which correspond on the average to the maximum value of entropy (thermodynamic probability). The model allows for competition between mean-field effects and nucleon-nucleon interactions in the overlap zone of the interacting nuclei. The analysis presented here suggests a thermalized source picture of the decay of the projectile-like fragment. The validity of the reconstruction procedure for projectile-like fragments is discussed. (orig.)

  8. Reassigning the CaH+ 11Σ → 21Σ vibronic transition with CaD+

    Science.gov (United States)

    Condoluci, J.; Janardan, S.; Calvin, A. T.; Rugango, R.; Shu, G.; Sherrill, C. D.; Brown, K. R.

    2017-12-01

    We observe vibronic transitions in CaD+ between the 11Σ and 21Σ electronic states by resonance enhanced multiphoton photodissociation spectroscopy in a Coulomb crystal. The vibronic transitions are compared with previous measurements on CaH+. The result is a revised assignment of the CaH+ vibronic levels and a disagreement with multi-state-complete-active-space second-order perturbation theory theoretical calculations by approximately 700 cm-1. Updated high-level coupled-cluster calculations that include core-valence correlations reduce the disagreement between theory and experiment to 300 cm-1.

  9. Clinical Significance and Prognostic Value of CA72-4 Compared with CEA and CA19-9 in Patients with Gastric Cancer

    Directory of Open Access Journals (Sweden)

    M. Ychou

    2000-01-01

    Full Text Available Carcinoembryonic antigen (CEA and CA 19-9 are both widely used in the follow up of patients with gastrointestinal cancer. More recently another tumor marker, named CA 72-4 has been identified and characterized using two different monoclonal antibodies B72.3 and CC49. Several reports evaluated CA 72-4 as a serum tumor marker for gastric cancer and compared its clinical utility with that of CEA or CA 19-9; few reports concerned its prognostic value. In the present study, CA 72-4 is evaluated and compared with CEA and CA 19-9 in various populations of patients with gastric cancer and benign disease; for 52 patients with gastric adenocarcinoma and 57 patients without neoplastic disease CEA, CA 19-9 and CA 72-4 were evaluated before treatment. Sensitivity of the tumor markers CA 72-4, CA 19-9 and CEA at the recommended cut-off level in all 52 patients were 58%, 50% the sensitivity increased to 75%. of these markers, for non metastatic patients, multivariate analyses indicated that none of the markers were significant, when adjusted for gender and age (which were indicators of poor prognosis; patients with abnormal values of CA72-4 tended to have shorter survival than patients with normal values (p < 0.07. In the metastatic population, only high values of CA19-9 (p < 0.02 and gender (women (p < 0.03 were indicators of poor prognosis in univariate analysis; multivariate analysis revealed that both CA72-4 (p = 0.034 and CA19-9 p = 0.009, adjusted for gender were independent prognostic factors. However, CA72-4 lost significance (p = 0.41 when adjusted for CA19-9 and gender, indicating that CA19-9 provides more prognostic information than CA72-4.

  10. Semantic web data warehousing for caGrid.

    Science.gov (United States)

    McCusker, James P; Phillips, Joshua A; González Beltrán, Alejandra; Finkelstein, Anthony; Krauthammer, Michael

    2009-10-01

    The National Cancer Institute (NCI) is developing caGrid as a means for sharing cancer-related data and services. As more data sets become available on caGrid, we need effective ways of accessing and integrating this information. Although the data models exposed on caGrid are semantically well annotated, it is currently up to the caGrid client to infer relationships between the different models and their classes. In this paper, we present a Semantic Web-based data warehouse (Corvus) for creating relationships among caGrid models. This is accomplished through the transformation of semantically-annotated caBIG Unified Modeling Language (UML) information models into Web Ontology Language (OWL) ontologies that preserve those semantics. We demonstrate the validity of the approach by Semantic Extraction, Transformation and Loading (SETL) of data from two caGrid data sources, caTissue and caArray, as well as alignment and query of those sources in Corvus. We argue that semantic integration is necessary for integration of data from distributed web services and that Corvus is a useful way of accomplishing this. Our approach is generalizable and of broad utility to researchers facing similar integration challenges.

  11. CaV1.3 L-type Ca2+ channels modulate depression-like behaviour in mice independent of deaf phenotype.

    Science.gov (United States)

    Busquet, Perrine; Nguyen, Ngoc Khoi; Schmid, Eduard; Tanimoto, Naoyuki; Seeliger, Mathias W; Ben-Yosef, Tamar; Mizuno, Fengxia; Akopian, Abram; Striessnig, Jörg; Singewald, Nicolas

    2010-05-01

    Mounting evidence suggests that voltage-gated L-type Ca2+ channels can modulate affective behaviour. We therefore explored the role of CaV1.3 L-type Ca2+ channels in depression- and anxiety-like behaviours using CaV1.3-deficient mice (CaV1.3-/-). We showed that CaV1.3-/- mice displayed less immobility in the forced swim test as well as in the tail suspension test, indicating an antidepressant-like phenotype. Locomotor activity in the home cage or a novel open-field test was not influenced. In the elevated plus maze (EPM), CaV1.3-/- mice entered the open arms more frequently and spent more time there indicating an anxiolytic-like phenotype which was, however, not supported in the stress-induced hyperthermia test. By performing parallel experiments in Claudin 14 knockout mice (Cldn14-/-), which like CaV1.3-/- mice are congenitally deaf, an influence of deafness on the antidepressant-like phenotype could be ruled out. On the other hand, a similar EPM behaviour indicative of an anxiolytic phenotype was also found in the Cldn14-/- animals. Using electroretinography and visual behavioural tasks we demonstrated that at least in mice, CaV1.3 channels do not significantly contribute to visual function. However, marked morphological changes were revealed in synaptic ribbons in the outer plexiform layer of CaV1.3-/- retinas by immunohistochemistry suggesting a possible role of this channel type in structural plasticity at the ribbon synapse. Taken together, our findings indicate that CaV1.3 L-type Ca2+ channels modulate depression-like behaviour but are not essential for visual function. The findings raise the possibility that selective modulation of CaV1.3 channels could be a promising new therapeutic concept for the treatment of mood disorders.

  12. Neomysin inhibits Ca2+-stimulated phosphatidylinositol hydrolysis and protects cultured rat cardiomyocytes from Ca2+-dependent cell injury

    International Nuclear Information System (INIS)

    Babson, J.R.; Dougherty, J.M.

    1991-01-01

    Exposure of cultured rat cardiomyocytes to ionomycin and extracellular Ca 2+ leads to a rapid, sustained increase in intracellular free Ca 2+ as monitored by Ca 2+ -dependent phosphorylase a activation and to a subsequent loss of cardiomyocyte viability as determined by lactate dehydrogenase (LDH) leakage. The intracellular free Ca 2+ increase coincided with a rapid hydrolysis of phosphatidylinositol that preceded cell death. Phosphatidylinositol hydrolysis was monitored by the release of radiolabeled phosphoinositides from cardiomyocytes prelabeled with [2- 3 H]-myo-inositol. Neomycin, a known inhibitor of phospholipase C, inhibited the phosphatidylinositol hydrolysis and markedly reduced the extent of cell injury. Inhibitors of other Ca 2+ -activated processes, including intracellular proteases and phospholipase A 2 , had no effect on ionomycin-mediated cell injury. These data suggest that ionomycin-induced Ca 2+ -dependent cell injury in cultured cardiomyocytes may be due in part to the stimulation of phosphatidylinositol hydrolysis, presumably catalyzed by a Ca 2+ -dependent phospholipase C

  13. Theoretical basal Ca II fluxes for late-type stars: results from magnetic wave models with time-dependent ionization and multi-level radiation treatments

    Science.gov (United States)

    Fawzy, Diaa E.; Stȩpień, K.

    2018-03-01

    In the current study we present ab initio numerical computations of the generation and propagation of longitudinal waves in magnetic flux tubes embedded in the atmospheres of late-type stars. The interaction between convective turbulence and the magnetic structure is computed and the obtained longitudinal wave energy flux is used in a self-consistent manner to excite the small-scale magnetic flux tubes. In the current study we reduce the number of assumptions made in our previous studies by considering the full magnetic wave energy fluxes and spectra as well as time-dependent ionization (TDI) of hydrogen, employing multi-level Ca II atomic models, and taking into account departures from local thermodynamic equilibrium. Our models employ the recently confirmed value of the mixing-length parameter α=1.8. Regions with strong magnetic fields (magnetic filling factors of up to 50%) are also considered in the current study. The computed Ca II emission fluxes show a strong dependence on the magnetic filling factors, and the effect of time-dependent ionization (TDI) turns out to be very important in the atmospheres of late-type stars heated by acoustic and magnetic waves. The emitted Ca II fluxes with TDI included into the model are decreased by factors that range from 1.4 to 5.5 for G0V and M0V stars, respectively, compared to models that do not consider TDI. The results of our computations are compared with observations. Excellent agreement between the observed and predicted basal flux is obtained. The predicted trend of Ca II emission flux with magnetic filling factor and stellar surface temperature also agrees well with the observations but the calculated maximum fluxes for stars of different spectral types are about two times lower than observations. Though the longitudinal MHD waves considered here are important for chromosphere heating in high activity stars, additional heating mechanism(s) are apparently present.

  14. Assessment of diagnostic value of various tumors markers (CEA, CA199, CA50) for colorectal neoplasm with logistic regression and ROC curve

    International Nuclear Information System (INIS)

    Gu Ping; Huang Gang; Han Yuan

    2007-01-01

    Objective: To assess the diagnostic value of CEA, CA199 and CA50 for colorectal neoplasm by logistic regression and ROC curve. Methods: Serum CEA (with CLIA), CA199 (with ECLIA) and CA50 (with IRMA) levels were measured in 75 patients with colorectal cancer, 35 patients with benign colorectal disorders and 49 controls. The area under the ROC curve (AUC)s of CEA, CA199, CA50 from logistic regression results were compared. Results: In the cancer-benign disorder group, the AUC of CA50 was larger than the AUC of CA199. AUC of combined CEA, CA50 was largest: not only larger than any AUC of CEA, CA50, CA199 alone but also larger than the AUC of the combined three markers (0.875 vs 0.604). In cancer-control group, the AUC of combination of CEA, CA199 and CA50 was larger than any AUC of CEA, CA199 or CA50 alone. Both in the cancer-benign disorder group or cancer-control group, the AUC of CEA was larger than the AUC of CA199 or CA50. Conclusion: CEA is of definite value in the diagnosis of colorectal cancer. For differential diagnosis, the combination of CEA and CA50 can give more information, while the combination of three tumor markers is less helpful. As an advanced statistical method, logistic regression can improve the diagnostic sensitivity and specificity. (authors)

  15. Tumour associated antigen CA-50, CA-242 immunoradiometric assay (IRMA) in genitourinary malignancy and gastrointestinal carcinoma early diagnosis

    International Nuclear Information System (INIS)

    Chen Zhizhou.

    1992-04-01

    Tumour markers CA-50 and CA-242 were measured by immunometric assay (IRMA) to investigate their usefulness in the diagnosis of cancer of the pancreas, biliary tract, liver, breast, lung, gastrointestinal and genitourinary systems. The cutoff points, derived from studies on normal subjects and those with proven benign disease, were 20 u/ml and 12 u/ml for CA-50 and CA-242 respectively. Both markers were found to be generally useful with significant differences between malignant and non malignant disease. The highest positive rates, were found in cancers of the pancreas and gall bladder. The overall rate of false positives was low. It is concluded that measurements of CA-50 and CA-242 are useful in the detection of malignancy, particularly of the pancreas and biliary tract. 2 figs, 2 tabs

  16. Subcellular distribution of glycogen and decreased tetanic Ca2+ in fatigued single intact mouse muscle fibres

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Cheng, Arthur J; Ørtenblad, Niels

    2014-01-01

    In skeletal muscle fibres, glycogen has been shown to be stored at different subcellular locations: (i) between the myofibrils (intermyofibrillar); (ii) within the myofibrils (intramyofibrillar); and (iii) subsarcolemmal. Of these, intramyofibrillar glycogen has been implied as a critical regulator...... of sarcoplasmic reticulum Ca(2+) release. The aim of the present study was to test directly how the decrease in cytoplasmic free Ca(2+) ([Ca(2+)]i) during repeated tetanic contractions relates to the subcellular glycogen distribution. Single fibres of mouse flexor digitorum brevis muscles were fatigued with 70 Hz...... in tetanic [Ca(2+)]i, and hence force, is accompanied by major reductions in inter- and intramyofibrillar glycogen. The stronger correlation between decreased tetanic [Ca(2+)]i and reduced intramyofibrillar glycogen implies that sarcoplasmic reticulum Ca(2+) release critically depends on energy supply from...

  17. CaEDTA vs CaEDTA plus BAL to treat children with elevated blood lead levels.

    Science.gov (United States)

    O'Connor, M E

    1992-07-01

    The effectiveness of CaEDTA alone vs CaEDTA plus BAL was compared retrospectively in a group of 72 children with lead levels between 2.41 mumol/L (50 micrograms/dL) and 2.90 mumol/L (60 micrograms/dL). The children who received both drugs had higher median zinc protoporphyrin (ZnP) concentrations at the initiation of therapy than children who received CaEDTA alone (160 micrograms/dL vs 96 micrograms/dL, p less than .01). There was a significantly increased incidence of vomiting and abnormal liver-function test results in the children who received both drugs. The children who received CaEDTA alone had a greater percent mean fall in lead level at one to three weeks postchelation (30.5% vs 18.1%, p less than .05). Children who received both CaEDTA and BAL had a greater percent decrease in ZnP at four to eight months postchelation, but there was no difference in percent decrease in lead levels. Children who received both drugs also had a greater number of repeat courses of chelation by six months. The addition of BAL to CaEDTA for treatment of children with lead levels of 2.41 mumol/L (50 micrograms/dL) to 2.90 mumol/L (60 micrograms/dL) produced greater toxicity and does not seem to prevent repeat chelations within six months.

  18. Ca2+ pump and Ca2+/H+ antiporter in plasma membrane vesicles isolated by aqueous two-phase partitioning from corn leaves

    International Nuclear Information System (INIS)

    Kasai, M.; Muto, S.

    1990-01-01

    Plasma membrane vesicles, which are mostly right side-out, were isolated from corn leaves by aqueous two-phase partitioning method. Characteristics of Ca2+ transport were investigated after preparing inside-out vesicles by Triton X-100 treatment. 45Ca2+ transport was assayed by membrane filtration technique. Results showed that Ca2+ transport into the plasma membrane vesicles was Mg-ATP dependent. The active Ca2+ transport system had a high affinity for Ca2+(Km(Ca2+) = 0.4 microM) and ATP(Km(ATP) = 3.9 microM), and showed pH optimum at 7.5. ATP-dependent Ca2+ uptake in the plasma membrane vesicles was stimulated in the presence of Cl- or NO3-. Quenching of quinacrine fluorescence showed that these anions also induced H+ transport into the vesicles. The Ca2+ uptake stimulated by Cl- was dependent on the activity of H+ transport into the vesicles. However, carbonylcyanide m-chlorophenylhydrazone (CCCP) and VO4(3-) which is known to inhibit the H+ pump associated with the plasma membrane, canceled almost all of the Cl(-)-stimulated Ca2+ uptake. Furthermore, artificially imposed pH gradient (acid inside) caused Ca2+ uptake into the vesicles. These results suggest that the Cl(-)-stimulated Ca2+ uptake is caused by the efflux of H+ from the vesicles by the operation of Ca2+/H+ antiport system in the plasma membrane. In Cl(-)-free medium, H+ transport into the vesicles scarcely occurred and the addition of CCCP caused only a slight inhibition of the active Ca2+ uptake into the vesicles. These results suggest that two Ca2+ transport systems are operating in the plasma membrane from corn leaves, i.e., one is an ATP-dependent active Ca2+ transport system (Ca2+ pump) and the other is a Ca2+/H+ antiport system. Little difference in characteristics of Ca2+ transport was observed between the plasma membranes isolated from etiolated and green corn leaves

  19. CaWingz user's guide

    International Nuclear Information System (INIS)

    Cha, Ben-chin.

    1994-01-01

    This document assumes that you have read and understood the Wingz user's manuals. CaWingz is an external Wingz program which, when combined with a set of script files, provides easy-to-use EPICS channel access interface functions for Wingz users. The external function run allows Wingz user to invoke any Unix processor within caWingz. Few additional functions for accessing static database field and monitoring of value change event is available for EPICS users after release 3.11. The functions, script files, and usage are briefly described in this document. The script files supplied here serve as examples only. Users are responsible for generating their own spreadsheet and script files. CaWingz communicates with IOC through channel access function calls

  20. Excitation energy transfer to luminescence centers in M{sup II}MoO{sub 4} (M{sup II}=Ca, Sr, Zn, Pb) and Li{sub 2}MoO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Spassky, D.A., E-mail: deris2002@mail.ru [Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie Gory 1, bld.2, 119991 Moscow (Russian Federation); National University of Science and Technology (MISiS), Leninsky Prospekt 4, 119049 Moscow (Russian Federation); Kozlova, N.S. [National University of Science and Technology (MISiS), Leninsky Prospekt 4, 119049 Moscow (Russian Federation); Nagirnyi, V. [Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu (Estonia); Savon, A.E. [Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie Gory 1, bld.2, 119991 Moscow (Russian Federation); Hizhnyi, Yu.A.; Nedilko, S.G. [Taras Shevchenko National University of Kyiv, Volodymyrska str. 64/13, 01601 Kyiv (Ukraine)

    2017-06-15

    Based on the results of spectroscopy studies and electronic band structure calculations, the analysis of excitation energy transformation into luminescence is performed for a set of molybdates M{sup II}MoO{sub 4} (M{sup II}=Ca, Sr, Zn, Pb) and Li{sub 2}MoO{sub 4}. The bandgap energies were determined from comparison of experimental and calculated reflectivity spectra as 3.3 eV for PbMoO{sub 4}, 4.3 eV for ZnMoO{sub 4}, 4.4 eV for CaMoO{sub 4}, 4.7 eV for SrMoO{sub 4}, and 4.9 eV for Li{sub 2}MoO{sub 4}. It is shown that photoluminescence excitation spectra of these materials reveal the specific features of their conduction bands. The threshold of separated charge carriers’ creation is shown to be by 1.3–1.9 eV higher than the bandgap energy in CaMoO{sub 4}, SrMoO{sub 4} and ZnMoO{sub 4}. The effect is explained by the peculiarities of conduction band structure, namely to the presence of gap between the subbands of the conduction band and to the low mobility of electrons in the lower sub-band of the conduction band.

  1. Protein Kinase Cα and P-Type Ca2+ Channel CaV2.1 in Red Blood Cell Calcium Signalling

    Directory of Open Access Journals (Sweden)

    Lisa Wagner-Britz

    2013-06-01

    Full Text Available Background/Aims: Protein kinase Cα (PKCα is activated by an increase in cytosolic Ca2+ in red blood cells (RBCs. Previous work has suggested that PKCα directly stimulates the CaV2.1 channel, whereas other studies revealed that CaV2.1 is insensitive to activation by PKC. The aim of this study was to resolve this discrepancy. Methods: We performed experiments based on a single cell read-out of the intracellular Ca2+ concentration in terms of Fluo-4 fluorescence intensity and phosphatidylserine exposure to the external membrane leaflet. Measurement modalities included flow cytometry and live cell imaging. Results: Treatment of RBCs with phorbol 12-myristate 13-acetate (PMA led to two distinct populations of cells with an increase in intracellular Ca2+: a weak-responding and a strong-responding population. The EC50 of PMA for the number of cells with Ca2+ elevation was 2.7±1.2 µM; for phosphatidylserine exposure to the external membrane surface, it was 2.8±0.5 µM; and for RBC haemolysis, it was 2.9±0.5 µM. Using pharmacological manipulation with the CaV2.1 inhibitor ω-agatoxin TK and the broad protein kinase C inhibitor Gö6983, we are able to show that there are two independent PMA-activated Ca2+ entry processes: the first is independent of CaV2.1 and directly PKCα-activated, while the second is associated with a likely indirect activation of CaV2.1. Further studies using lysophosphatidic acid (LPA as a stimulation agent have provided additional evidence that PKCα and CaV2.1 are not directly interconnected in a signalling chain. Conclusion: Although we provide evidence for a lack of interaction between PKCα and CaV2.1 in RBCs, further studies are required to decipher the signalling relationship between LPA, PKCα and CaV2.1.

  2. Lysosomes shape Ins(1,4,5)P3-evoked Ca2+ signals by selectively sequestering Ca2+ released from the endoplasmic reticulum

    Science.gov (United States)

    López-Sanjurjo, Cristina I.; Tovey, Stephen C.; Prole, David L.; Taylor, Colin W.

    2013-01-01

    Summary Most intracellular Ca2+ signals result from opening of Ca2+ channels in the plasma membrane or endoplasmic reticulum (ER), and they are reversed by active transport across these membranes or by shuttling Ca2+ into mitochondria. Ca2+ channels in lysosomes contribute to endo-lysosomal trafficking and Ca2+ signalling, but the role of lysosomal Ca2+ uptake in Ca2+ signalling is unexplored. Inhibition of lysosomal Ca2+ uptake by dissipating the H+ gradient (using bafilomycin A1), perforating lysosomal membranes (using glycyl-L-phenylalanine 2-naphthylamide) or lysosome fusion (using vacuolin) increased the Ca2+ signals evoked by receptors that stimulate inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] formation. Bafilomycin A1 amplified the Ca2+ signals evoked by photolysis of caged Ins(1,4,5)P3 or by inhibition of ER Ca2+ pumps, and it slowed recovery from them. Ca2+ signals evoked by store-operated Ca2+ entry were unaffected by bafilomycin A1. Video-imaging with total internal reflection fluorescence microscopy revealed that lysosomes were motile and remained intimately associated with the ER. Close association of lysosomes with the ER allows them selectively to accumulate Ca2+ released by Ins(1,4,5)P3 receptors. PMID:23097044

  3. S-glutathionylation of troponin I (fast) increases contractile apparatus Ca2+ sensitivity in fast-twitch muscle fibres of rats and humans.

    Science.gov (United States)

    Mollica, J P; Dutka, T L; Merry, T L; Lamboley, C R; McConell, G K; McKenna, M J; Murphy, R M; Lamb, G D

    2012-03-15

    Oxidation can decrease or increase the Ca2+ sensitivity of the contractile apparatus in rodent fast-twitch (type II) skeletal muscle fibres, but the reactions and molecular targets involved are unknown. This study examined whether increased Ca2+ sensitivity is due to S-glutathionylation of particular cysteine residues. Skinned muscle fibres were directly activated in heavily buffered Ca2+ solutions to assess contractile apparatus Ca2+ sensitivity. Rat type II fibres were subjected to S-glutathionylation by successive treatments with 2,2′-dithiodipyridine (DTDP) and glutathione (GSH), and displayed a maximal increase in pCa50 (−log10 [Ca2+] at half-maximal force) of ∼0.24 pCa units, with little or no effect on maximum force or Hill coefficient. Partial similar effect was produced by exposure to oxidized gluthathione (GSSG, 10 mM) for 10 min at pH 7.1, and near-maximal effect by GSSG treatment at pH 8.5. None of these treatments significantly altered Ca2+ sensitivity in rat type I fibres. Western blotting showed that both the DTDP–GSH and GSSG–pH 8.5 treatments caused marked S-glutathionylation of the fast troponin I isoform (TnI(f)) present in type II fibres, but not of troponin C (TnC) or myosin light chain 2. Both the increased Ca2+ sensitivity and glutathionylation of TnI(f) were blocked by N-ethylmaleimide (NEM). S-nitrosoglutathione (GSNO) also increased Ca2+ sensitivity, but only in conditions where it caused S-glutathionylation of TnI(f). In human type II fibres from vastus lateralis muscle, DTDP–GSH treatment also caused similar increased Ca2+ sensitivity and S-glutathionylation of TnI(f). When the slow isoform of TnI in type I fibres of rat was partially substituted (∼30%) with TnI(f), DTDP–GSH treatment caused a significant increase in Ca2+ sensitivity (∼0.08 pCa units). TnIf in type II fibres from toad and chicken muscle lack Cys133 present in mammalian TnIf, and such fibres showed no change in Ca2+ sensitivity with DTDP–GSH nor any S

  4. Altered thalamocortical rhythmicity and connectivity in mice lacking CaV3.1 T-type Ca2+ channels in unconsciousness

    Science.gov (United States)

    Choi, Soonwook; Yu, Eunah; Lee, Seongwon; Llinás, Rodolfo R.

    2015-01-01

    In unconscious status (e.g., deep sleep and anesthetic unconsciousness) where cognitive functions are not generated there is still a significant level of brain activity present. Indeed, the electrophysiology of the unconscious brain is characterized by well-defined thalamocortical rhythmicity. Here we address the ionic basis for such thalamocortical rhythms during unconsciousness. In particular, we address the role of CaV3.1 T-type Ca2+ channels, which are richly expressed in thalamic neurons. Toward this aim, we examined the electrophysiological and behavioral phenotypes of mice lacking CaV3.1 channels (CaV3.1 knockout) during unconsciousness induced by ketamine or ethanol administration. Our findings indicate that CaV3.1 KO mice displayed attenuated low-frequency oscillations in thalamocortical loops, especially in the 1- to 4-Hz delta band, compared with control mice (CaV3.1 WT). Intriguingly, we also found that CaV3.1 KO mice exhibited augmented high-frequency oscillations during unconsciousness. In a behavioral measure of unconsciousness dynamics, CaV3.1 KO mice took longer to fall into the unconscious state than controls. In addition, such unconscious events had a shorter duration than those of control mice. The thalamocortical interaction level between mediodorsal thalamus and frontal cortex in CaV3.1 KO mice was significantly lower, especially for delta band oscillations, compared with that of CaV3.1 WT mice, during unconsciousness. These results suggest that the CaV3.1 channel is required for the generation of a given set of thalamocortical rhythms during unconsciousness. Further, that thalamocortical resonant neuronal activity supported by this channel is important for the control of vigilance states. PMID:26056284

  5. Ablation of Ca(V)2.1 voltage-gated Ca²⁺ channels in mouse forebrain generates multiple cognitive impairments.

    Science.gov (United States)

    Mallmann, Robert Theodor; Elgueta, Claudio; Sleman, Faten; Castonguay, Jan; Wilmes, Thomas; van den Maagdenberg, Arn; Klugbauer, Norbert

    2013-01-01

    Voltage-gated Ca(V)2.1 (P/Q-type) Ca²⁺ channels located at the presynaptic membrane are known to control a multitude of Ca²⁺-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic Ca(V)2.1 mouse models. Global Ca(V)2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of Ca(V)2.1 Ca²⁺ channels for complex behaviour in adult mice. Consequently we established a forebrain specific Ca(V)2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of Ca(V)2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific Ca(V)2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional Ca(V)2.1 knock-out model that is most suitable for analysing the in vivo functions of Ca(V)2.1 in the adult murine forebrain.

  6. Roles of EDTA washing and Ca{sup 2+} regulation on the restoration of anammox granules inhibited by copper(II)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zheng-Zhe; Cheng, Ya-Fei; Zhou, Yu-Huang; Buayi, Xiemuguli [Department of Environmental Science and Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou 310036 (China); Jin, Ren-Cun, E-mail: jrczju@aliyun.com [Department of Environmental Science and Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou 310036 (China)

    2016-01-15

    Highlights: • 80.5% of the Cu in anammox granules was introduced via adsorption. • Cu(II) internalized on/into AnAOB cells plays a crucial role in toxicity. • EDTA washing contributes to the detoxification of anammox granules. • Ca{sup 2+} can stimulate the re-growth of damaged anammox consortium. - Abstract: We investigated the feasibility of using ethylene diamine tetraacetic acid (EDTA) washing followed by Ca{sup 2+} enhancement for the recovery of anammox reactors inhibited by Cu(II). Kinetic experiments and batch activity assays were employed to determine the optimal concentration of EDTA and washing time; and the performance and physiological dynamics were tracked by continuous-flow monitoring to evaluate the long-term effects. The two-step desorption process revealed that the Cu in anammox granules was primarily introduced via adsorption (approximately, 80.5%), and the portion of Cu in the dispersible layer was predominant (accounting for 71.1%). Afterwards, the Cu internalized in the cells (approximately, 14.7%) could diffuse out of the cells and be gradually washed out of the reactor over the next 20 days. The Ca{sup 2+} addition that followed led to an accelerated nitrogen removal rate recovery slope (0.1491 kgN m{sup −3} d{sup −2}) and a normal biomass growth rate (0.054 d{sup −1}). The nitrogen removal rate returned to normal levels within 90 days and gradual improvements in granular characteristics were also achieved. Therefore, this study provides a new insight that externally removing the adsorbed heavy metals followed by internally repairing the metabolic system may represent an optimal restoration strategy for anammox consortium damaged by heavy metals.

  7. A model of cardiac ryanodine receptor gating predicts experimental Ca2+-dynamics and Ca2+-triggered arrhythmia in the long QT syndrome

    Science.gov (United States)

    Wilson, Dan; Ermentrout, Bard; Němec, Jan; Salama, Guy

    2017-09-01

    Abnormal Ca2+ handling is well-established as the trigger of cardiac arrhythmia in catecholaminergic polymorphic ventricular tachycardia and digoxin toxicity, but its role remains controversial in Torsade de Pointes (TdP), the arrhythmia associated with the long QT syndrome (LQTS). Recent experimental results show that early afterdepolarizations (EADs) that initiate TdP are caused by spontaneous (non-voltage-triggered) Ca2+ release from Ca2+-overloaded sarcoplasmic reticulum (SR) rather than the activation of the L-type Ca2+-channel window current. In bradycardia and long QT type 2 (LQT2), a second, non-voltage triggered cytosolic Ca2+ elevation increases gradually in amplitude, occurs before overt voltage instability, and then precedes the rise of EADs. Here, we used a modified Shannon-Puglisi-Bers model of rabbit ventricular myocytes to reproduce experimental Ca2+ dynamics in bradycardia and LQT2. Abnormal systolic Ca2+-oscillations and EADs caused by SR Ca2+-release are reproduced in a modified 0-dimensional model, where 3 gates in series control the ryanodine receptor (RyR2) conductance. Two gates control RyR2 activation and inactivation and sense cytosolic Ca2+ while a third gate senses luminal junctional SR Ca2+. The model predicts EADs in bradycardia and low extracellular [K+] and cessation of SR Ca2+-release terminate salvos of EADs. Ca2+-waves, systolic cell-synchronous Ca2+-release, and multifocal diastolic Ca2+ release seen in subcellular Ca2+-mapping experiments are observed in the 2-dimensional version of the model. These results support the role of SR Ca2+-overload, abnormal SR Ca2+-release, and the subsequent activation of the electrogenic Na+/Ca2+-exchanger as the mechanism of TdP. The model offers new insights into the genesis of cardiac arrhythmia and new therapeutic strategies.

  8. ORF Alignment: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available n CaO19.6989 [Candida albicans SC5314] ... Length = 94 ... Query: 11 ... VKNLPYNTSNSSLYEFFGKYGYINQIRINSSQPG...TCFIIYHNIKNAQRAAQDLNGVNFNG 70 ... VKNLPYNTSNSSLYEFFGKYGYINQIRINSSQPGTCFIIY...HNIKNAQRAAQDLNGVNFNG Sbjct: 1 ... VKNLPYNTSNSSLYEFFGKYGYINQIRINSSQPGTCFIIYHNIKNAQRAAQDLNGVNFNG 60 ...

  9. CA 19-9 and CA 125 as potential predictors of disease recurrence in resectable lung adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Sofi Isaksson

    Full Text Available Among patients who underwent primary surgery for non-small cell lung cancer (NSCLC, recurrent disease is frequent and cannot be accurately predicted solely from TNM stage and histopathological features. The aim of this study was to examine the association of tumor markers in pre-operative serum with recurrent disease.Blood samples were collected prior to lung cancer surgery from 107 patients with stage I-III lung adenocarcinoma surgically treated at Lund University hospital, Lund, Sweden, between 2005 and 2011. The serum tumor markers Carcinoembryonic antigen (CEA, Neuron-specific enolase (NSE, Cancer antigen 125 (CA 125, Human epididymis protein 4 (HE4 and Carbohydrate antigen (CA 19-9 were analyzed retrospectively and clinical follow-up data were collected from patient charts. Forty (37% patients were diagnosed with recurrent disease.Sixty-eight (64% patients had at least one elevated tumor marker prior to surgery. In analysis of disease-free survival (DFS, CA 125 and/or CA 19-9 were significantly associated with recurrent disease adjusted to stage and adjuvant treatment (hazard ratio 2.8, 95% confidence interval 1.4-5.7, p = 0.006.High pre-operative serum CA 19-9 and/or CA 125 might indicate an increased incidence of recurrent disease in resectable lung adenocarcinomas.

  10. The investigation of minoxidil-induced [Ca2+]i rises and non-Ca2+-triggered cell death in PC3 human prostate cancer cells.

    Science.gov (United States)

    Chen, I-Shu; Chou, Chiang-Ting; Liu, Yuan-Yuarn; Yu, Chia-Cheng; Liang, Wei-Zhe; Kuo, Chun-Chi; Shieh, Pochuen; Kuo, Daih-Huang; Chen, Fu-An; Jan, Chung-Ren

    2017-02-01

    Minoxidil is clinically used to prevent hair loss. However, its effect on Ca 2+ homeostasis in prostate cancer cells is unclear. This study explored the effect of minoxidil on cytosolic-free Ca 2+ levels ([Ca 2+ ] i ) and cell viability in PC3 human prostate cancer cells. Minoxidil at concentrations between 200 and 800 μM evoked [Ca 2+ ] i rises in a concentration-dependent manner. This Ca 2+ signal was inhibited by 60% by removal of extracellular Ca 2+ . Minoxidil-induced Ca 2+ influx was confirmed by Mn 2+ -induced quench of fura-2 fluorescence. Pre-treatment with the protein kinase C (PKC) inhibitor GF109203X, PKC activator phorbol 12-myristate 13 acetate (PMA), nifedipine and SKF96365 inhibited minoxidil-induced Ca 2+ signal in Ca 2+ containing medium by 60%. Treatment with the endoplasmic reticulum Ca 2+ pump inhibitor 2,5-ditert-butylhydroquinone (BHQ) in Ca 2+ -free medium abolished minoxidil-induced [Ca 2+ ] i rises. Conversely, treatment with minoxidil abolished BHQ-induced [Ca 2+ ] i rises. Inhibition of phospholipase C (PLC) with U73122 abolished minoxidil-evoked [Ca 2+ ] i rises. Overnight treatment with minoxidil killed cells at concentrations of 200-600 μM in a concentration-dependent fashion. Chelation of cytosolic Ca 2+ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM) did not prevent minoxidil's cytotoxicity. Together, in PC3 cells, minoxidil induced [Ca 2+ ] i rises that involved Ca 2+ entry through PKC-regulated store-operated Ca 2+ channels and PLC-dependent Ca 2+ release from the endoplasmic reticulum. Minoxidil-induced cytotoxicity in a Ca 2+ -independent manner.

  11. Diagnostic significance of tumor markers CEA, CA50 and CA19-9 for colorectal cancer

    International Nuclear Information System (INIS)

    Chen Yumei; Huang Gang

    2005-01-01

    Objective: To investigate the expression and diagnostic significance of three serum tumor markers (CEA, CA50, CA19-9) in patients with colorectal cancer, with special emphasis on their combined assay. Methods: Serum CEA, CA19-9 levels (with chemiluminescence immunoassay) and CA50 levels (with immunoradiometric assay) were determined in 94 patients with colorectal cancer, 20 patients with benign colorectal disorders and 37 controls. Results: The expressions of the serum tumor markers were significantly higher in patients with colorectal cancer than those in patients with benign colorectal disorders and controls (P<0.05). There was no significant difference between the levels in the latter two groups. CEA assay had the highest sensitivity (57.4%) and specificity (85.9%). Combined assay of the three could enhance both the sensitivity (62.7%) and specificity (96.5%). The serum levels of the markers were significantly higher in patients with colonic cancer than those in patients with rectal cancer (P<0.05). The levels were positively correlated with the size of the growth and stage of the disease. Serum tumor marker levels were also significantly higher in patients with metastasis (regional/distant) than those in patients without metastasis (P<0.05). Conclusion: Determination of serum CEA, CA50 and CA19-9 levels had definite value for the diagnosis and assessment of the pathology as well as biologic behavior colorectal cancer. Combined assay of the three could enhance the diagnostic sensitivity and specificity. (authors)

  12. Study on the diagnostic value of combined determination of serum CA125, CA199 and SIL-2R levels in patients with endometriosis

    International Nuclear Information System (INIS)

    Yang Jingxiu; Shi Shaohong; Wang Yuping; Xie Xueqin; Qin Jibao

    2005-01-01

    Objective: To investigate the diagnostic values of combined determination of serum CA125, CA199 and SIL-2R levels in patients with endometriosis. Methods: Serum CA125, CA199 were measured with RIA and SIL-2R levels with ELISA in 54 patients with endometriosis and 35 controls. Results: The serum levels of CA125, CA199 and SIL-2R in patients with endometriosis were significantly higher than those in controls (P<0.01). The sensitivity and speciality of CA125 for endometriosis was 70.2% and 80.4% respectively, the sensitivity and speciality of CA199 for endometriosis was 62.4% and 71.8% respectively, the sensitivity and speciality of SIL-2R was 89.5% and 60.2% respectively. The sensitivity of the combined determination of CA125, CA199 and SIL-2R for endometriosis was 86.8% being significantly higher than that of CA125 and CA199 respectively. Conclusion: Combined determination of the serum CA125, CA199 and SIL-2R levels in serum can increase the diagnostic sensitivity for endometriosis. (authors)

  13. Thermal neutrons thermoluminescence dosimetry using CaF2 + KBr e CaSO4: Dy + Br

    International Nuclear Information System (INIS)

    Leite, A.M.P.

    1979-01-01

    Cold-pressed samples of CaF 2 + KBr and CaSO 4 :Dy + KBr have been used in the thermal neutron detection by the thermoluminescence technique. The amount of 100 mg of the TL phosphor added to 80 mg of KBr showed to be the optimum mixture regarding sensitivity as well as the handling of the dosimeters. The detection is based on the self-irradiation of the phosphor by the Br isotopes activated by exposure to a neutron-gama field. The prompt dose and consequentely the gama contribution are erased by post-irradiation thermal annealing. A linear dependence has been found between the TL self-induced signal and the thermal neutron flux in the range 10 6 n.cm -2 .seg -1 -10 -12 n.cm -2 .seg -1 . The minimum detectable fluence has benn determined as 10 9 n.cm -2 and 10 6 n.cm -2 using pellets of CaF 2 + KBr and CaSO 4 :Dy + KBr, respectively. The main results suggest the use of CaSO 4 :Dy + KBr pellets and TL as a complementary technique for thermal neutron detection. (author) [pt

  14. Differentiation of Human Adipose Derived Stem Cells into Smooth Muscle Cells Is Modulated by CaMKIIγ

    Directory of Open Access Journals (Sweden)

    Kaisaier Aji

    2016-01-01

    Full Text Available The multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII is known to participate in maintenance and switches of smooth muscle cell (SMC phenotypes. However, which isoform of CaMKII is involved in differentiation of adult mesenchymal stem cells into contractile SMCs remains unclear. In the present study, we detected γ isoform of CaMKII in differentiation of human adipose derived stem cells (hASCs into SMCs that resulted from treatment with TGF-β1 and BMP4 in combination for 7 days. The results showed that CaMKIIγ increased gradually during differentiation of hASCs as determined by real-time PCR and western blot analysis. The siRNA-mediated knockdown of CaMKIIγ decreased the protein levels and transcriptional levels of smooth muscle contractile markers (a-SMA, SM22a, calponin, and SM-MHC, while CaMKIIγ overexpression increases the transcriptional and protein levels of smooth muscle contractile markers. These results suggested that γ isoform of CaMKII plays a significant role in smooth muscle differentiation of hASCs.

  15. CaMKII effects on inotropic but not lusitropic force frequency responses require phospholamban

    OpenAIRE

    Wu, Yiming; Luczak, Elizabeth D; Lee, Eun-Jeong; Hidalgo, Carlos; Yang, Jinying; Gao, Zhan; Li, Jingdong; Wehrens, Xander; Granzier, Henk; Anderson, Mark E

    2012-01-01

    Increasing heart rate enhances cardiac contractility (force frequency relationship, FFR) and accelerates cardiac relaxation (frequency-dependent acceleration of relaxation, FDAR). The positive FFR together with FDAR promotes rapid filling and ejection of blood from the left ventricle (LV) at higher heart rates. Recent studies indicate that the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII) is involved in regulating FFR and FDAR. We used isolated perfused mouse hearts to ...

  16. Glucagon releases Ca2+ from a FCCP-sensitive pool

    International Nuclear Information System (INIS)

    Kraus-Friedmann, N.

    1986-01-01

    The effects of physiological levels of glucagon on Ca 2+ efflux were examined in the perfused rat liver. Two methods were used to estimate Ca 2+ efflux: (1) prior labeling of the Ca 2+ pools with 45 Ca 2+ , and (2) measurement of perfusate Ca 2+ with atomic absorption. According to both methods, glucagon administration at the physiological level evoked Ca 2+ release. In order to identify the hormone-sensitive Ca 2+ pool, a method employed by several laboratories was used. In this method, mitochondrial Ca 2+ is released by FCCP, (carbonyl-cyanide 4 (trifluoro/methoxy) phenylhydrazone), a mitochondrial uncoupler. The effect of hormones on Ca 2+ release after such uncoupler administration is measured. A decreased release is taken as an indication that the pool is entirely or partially mitochondrial. FCCP released 90 +/- 29 nmoles Ca 2+ /gr wet liver. Glucagon (5 x 10 -9 M) released 107 +/- 45 nmoles Ca 2+ /gr wet liver before and 26 +/- 9 nmoles Ca 2+ /gr wet liver after FCCP. These data indicate that glucagon releases Ca 2+ mostly from the mitochondria

  17. IP3 stimulates CA++ efflux from fusogenic carrot protoplasts

    International Nuclear Information System (INIS)

    Rincon, M.; Boss, W.F.

    1986-01-01

    Polyphosphoinositide breakdown plays an important role in signal transduction in animal cells (Berridge and Irvine, 1984, Nature, 312:315). Upon stimulation, phospholipase C hydrolyzes phosphatidylinositol 4,5-bisphosphate to inositol 1,4,5-trisphosphate (IP 3 ) and diacylglycerol both of which act as cellular second messengers. IP 3 mobilizes Ca ++ from internal stores, hence the cytosolic free Ca ++ concentration increases and those physiological activities regulated by Ca ++ are stimulated. To test if plant cells also responded to IP 3 , Ca ++ efflux studies were done with fusogenic carrot protoplasts released in EGTA. The protoplasts were preloaded with 45 Ca ++ placed in a Ca ++ -free medium, and efflux determined as 45 Ca ++ loss from the protoplasts. IP 3 (10-20μM) caused enhanced 45 Ca ++ efflux and the response was sustained for at least 15 min. In plants, as in animals, the observed IP 3 -enhanced 45 Ca ++ efflux suggested that IP 3 released Ca ++ from internal stores, and the increased free cytosolic Ca ++ activated Ca ++ pumping mechanisms which restored the Ca ++ concentration in the cytosol to the normal level

  18. Ablation of Ca(V2.1 voltage-gated Ca²⁺ channels in mouse forebrain generates multiple cognitive impairments.

    Directory of Open Access Journals (Sweden)

    Robert Theodor Mallmann

    Full Text Available Voltage-gated Ca(V2.1 (P/Q-type Ca²⁺ channels located at the presynaptic membrane are known to control a multitude of Ca²⁺-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic Ca(V2.1 mouse models. Global Ca(V2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of Ca(V2.1 Ca²⁺ channels for complex behaviour in adult mice. Consequently we established a forebrain specific Ca(V2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of Ca(V2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific Ca(V2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional Ca(V2.1 knock-out model that is most suitable for analysing the in vivo functions of Ca(V2.1 in the adult murine forebrain.

  19. Cation-exchange antibody labeling for simultaneous electrochemical detection of tumor markers CA15-3 and CA19-9

    International Nuclear Information System (INIS)

    Wang, Guangjie; Qing, Yi; Shan, Jinlu; Jin, Feng; Wang, Dong; Yuan, Ruo

    2013-01-01

    We report on a new kind of non-covalent multi-label electrochemical immunoassay that was applied to simultaneously quantify the tumor markers CA15-3 and CA19-9. The method employs a nanohybrid composed of an ionomer and conductive titanium dioxide nanoparticles that act as a matrix support for the antibodies. The two antibodies (anti-CA153 and anti-CA199) were labeled (a) with a cobaltous dipyridine complex, and (b) with methylene blue. Labeling is based on cation-exchange interaction rather than on covalent conjugation. The redox potentials of the two labels are separated by an interval of 0.3 V. The resulting sandwich-type immunosensor was read out by differential pulse voltammetry. The potential sites and currents of the two redox probes reflect the concentration of the two analytes. The two analytes were determined with a detection limit of 1.6 U mL −1 for CA19-9, and of 0.3 U mL −1 for CA15-3 (author)

  20. CaMKII regulates contraction- but not insulin-induced glucose uptake in mouse skeletal muscle.

    Science.gov (United States)

    Witczak, Carol A; Jessen, Niels; Warro, Daniel M; Toyoda, Taro; Fujii, Nobuharu; Anderson, Mark E; Hirshman, Michael F; Goodyear, Laurie J

    2010-06-01

    Studies using chemical inhibitors have suggested that the Ca(2+)-sensitive serine/threonine kinase Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of both insulin- and contraction-stimulated glucose uptake in skeletal muscle. However, due to nonspecificity of these inhibitors, the specific role that CaMKII may play in the regulation of glucose uptake is not known. We sought to determine whether specific inhibition of CaMKII impairs insulin- and/or contraction-induced glucose uptake in mouse skeletal muscle. Expression vectors containing green fluorescent protein conjugated to a CaMKII inhibitory (KKALHRQEAVDCL) or control (KKALHAQERVDCL) peptide were transfected into tibialis anterior muscles by in vivo electroporation. After 1 wk, muscles were assessed for peptide expression, CaMK activity, insulin- and contraction-induced 2-[(3)H]deoxyglucose uptake, glycogen concentrations, and changes in intracellular signaling proteins. Expression of the CaMKII inhibitory peptide decreased muscle CaMK activity approximately 35% compared with control peptide. Insulin-induced glucose uptake was not changed in muscles expressing the inhibitory peptide. In contrast, expression of the inhibitory peptide significantly decreased contraction-induced muscle glucose uptake (approximately 30%). Contraction-induced decreases in muscle glycogen were not altered by the inhibitory peptide. The CaMKII inhibitory peptide did not alter expression of the glucose transporter GLUT4 and did not impair contraction-induced increases in the phosphorylation of AMP-activated protein kinase (Thr(172)) or TBC1D1/TBC1D4 on phospho-Akt substrate sites. These results demonstrate that CaMKII does not regulate insulin-stimulated glucose uptake in skeletal muscle. However, CaMKII plays a critical role in the regulation of contraction-induced glucose uptake in mouse skeletal muscle.

  1. Juvenile Hippocampal CA2 Region Expresses Aggrecan

    Directory of Open Access Journals (Sweden)

    Asako Noguchi

    2017-05-01

    Full Text Available Perineuronal nets (PNNs are distributed primarily around inhibitory interneurons in the hippocampus, such as parvalbumin-positive interneurons. PNNs are also present around excitatory neurons in some brain regions and prevent plasticity in these neurons. A recent study demonstrated that PNNs also exist around mouse hippocampal pyramidal cells, which are the principle type of excitatory neurons, in the CA2 subregion and modulate the excitability and plasticity of these neurons. However, the development of PNNs in the CA2 region during postnatal maturation was not fully investigated. This study found that a main component of PNNs, aggrecan, existed in the pyramidal cell layer of the putative CA2 subarea prior to the appearance of the CA2 region, which was defined by the CA2 marker protein regulator of G protein signaling 14 (RGS14. We also found that aggrecan immunoreactivity was more evident in the anterior sections of the CA2 area than the posterior sections, which suggests that the function of CA2 PNNs varies along the anterior-posterior axis.

  2. CaMKII effects on inotropic but not lusitropic force frequency responses require phospholamban

    Science.gov (United States)

    Wu, Yiming; Luczak, Elizabeth D; Lee, Eun-Jeong; Hidalgo, Carlos; Yang, Jinying; Gao, Zhan; Li, Jingdong; Wehrens, Xander; Granzier, Henk; Anderson, Mark E

    2014-01-01

    Increasing heart rate enhances cardiac contractility (force frequency relationship, FFR) and accelerates cardiac relaxation (frequency-dependent acceleration of relaxation, FDAR). The positive FFR together with FDAR promotes rapid filling and ejection of blood from the left ventricle (LV) at higher heart rates. Recent studies indicate that the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII) is involved in regulating FFR and FDAR. We used isolated perfused mouse hearts to study the mechanisms of FFR and FDAR in different genetic models, including transgenic myocardial CaMKII inhibition (AC3-I) and phosphalamban knockout (PLN−/−). When the rate was increased from 360 beats/min to 630 beats/min in wild type mouse hearts, the LV developed pressure (LVDP) and the maximum rate of increase in pressure (dP/dt max) increased by 37.6 ± 4.7% and 77.0 ± 8.1%, respectively. However, hearts from AC3-I littermates showed no increase of LVDP and a relatively modest (20.4 ± 3.9 %) increase in dP/dt max. PLN−/− hearts had a negative FFR, and myocardial AC3-I expression did not change the FFR in PLN−/− mice. PLN−/− mouse hearts did not exhibit FDAR, while PLN−/−mice with myocardial AC3-I expression showed further frequency dependent reductions in cardiac relaxation, suggesting CaMKII targets in addition to PLN were critical to myocardial relaxation. We incubated a constitutively active form of CaMKII with chemically-skinned myocardium and found that several myofilament proteins were phosphorylated by CaMKII. However, CaMKII did not affect myofilament calcium sensitivity. Our study shows that CaMKII plays an important role in modulating FFR and FDAR in murine hearts and suggest that PLN is a critical target for CaMKII effects on FFR, while CaMKII effects on FDAR partially require PLN-alternative targets. PMID:22796260

  3. Mucins CA 125, CA 19.9, CA 15.3 and TAG-72.3 as tumor markers in patients with lung cancer: comparison with CYFRA 21-1, CEA, SCC and NSE.

    Science.gov (United States)

    Molina, Rafael; Auge, Jose Maria; Escudero, Jose Miguel; Marrades, Ramon; Viñolas, Nuria; Carcereny, Emilio; Ramirez, Jose; Filella, Xavier

    2008-01-01

    Tumor marker serum levels were prospectively studied in 289 patients with suspected, but unconfirmed, lung cancer and in 513 patients with lung cancer [417 non-small cell lung cancer (NSCLC) patients and 96 small cell lung cancer (SCLC) patients]. In patients with benign disease, abnormal serum levels were found for the following tumor markers: CEA (in 6.6% of patients); CA 19.9 (6.2%); CA 125 (28.7%); NSE (0.7%); CYFRA (8.7%); TAG-72.3 (4.2%); SCC (3.5%), and CA 15.3 (3.5%). Excluding patients with renal failure or liver diseases, tumor marker specificity improved with abnormal levels in 0.5% for NSE, 0.9% for SCC, 2.8% for CEA, CA 15.3 and TAG-72.3, 3.8% for CA 19.9, 4.2% for CYFRA and 21.4% for CA 125. Excluding CA 125, one of the markers was abnormal in 15% of patients without malignancy. Tumor marker sensitivity was related to cancer histology and tumor extension. NSE had the highest sensitivity in SCLC and CYFRA and CEA in NSCLC. Significantly higher concentrations of CEA, SCC, CA 125, CA 15.3 and TAG-72.3 were found in NSCLC than in SCLC. Likewise, significantly higher CEA (p tumors. Using a combination of 3 tumor markers (CEA, CYFRA 21-1 in all histologies, SCC in squamous tumors and CA 15.3 in adenocarcinomas), a high sensitivity may be achieved in all histological types. Tumor markers may be useful in the histological differentiation of NSCLC and SCLC. Using specific criteria for the differentiation of SCLC and NSCLC, the sensitivity was 84.2 and 68.8%, the specificity was 93.8 and 99.7%, the positive predictive value was 98.3 and 98.5% and the negative predictive value was 57.7 and 93.3%, respectively. Copyright 2008 S. Karger AG, Basel.

  4. High temperature hydrogenation of CaC6

    International Nuclear Information System (INIS)

    Srinivas, G.; Howard, C.A.; Skipper, N.T.; Bennington, S.M.; Ellerby, M.

    2009-01-01

    The structure and superconducting properties of high temperature hydrogenated calcium-graphite intercalation compound, CaC 6 have been investigated using room temperature X-ray diffraction, and temperature and field dependence of magnetisation. It is found that the hydrogenation can only decompose the CaC 6 phase, and generate a mixture of CaH 2 and graphite as the final compound. The hydrogenation of CaC 6 also reveals a degradation of its superconducting properties. The experimental results are discussed in detail and it is found that the formation of stable CaH 2 and deintercalation are the main source for observed phase separation and suppression in superconductivity.

  5. On the densification and hydration of CaCO3 particles by Q-switched laser pulses in water

    Science.gov (United States)

    Lin, Peng-Wen; Wu, Chao-Hsien; Zheng, Yuyuan; Chen, Shuei-Yuan; Shen, Pouyan

    2013-09-01

    Calcite powders subjected to Q-switched laser pulses in water were characterized by X-ray/electron diffraction and optical spectroscopy to have a significant internal compressive stress (up to ca. 1.5 GPa) with accompanied transformation into defective calcite II and hydrates. The defective calcite II particles were (0 1 0), (0 0 1), (0 1¯ 1), (0 1 3) and (0 1¯ 3) faceted with 2×(0 2 0)II commensurate superstructure and tended to hydrate epitaxially as monohydrocalcite co-existing with ikaite (CaCO3·6H2O) with extensive cleavages and amorphous calcium carbonate with porous structure. The colloidal suspension containing the densified calcite polymorphs and hydrates showed two UV-visible absorptions corresponding to a minimum band gap of ca. 5 and 3 eV, respectively.

  6. Plasma membrane Ca2+-ATPase 4: interaction with constitutive nitric oxide synthases in human sperm and prostasomes which carry Ca2+/CaM-dependent serine kinase.

    Science.gov (United States)

    Andrews, Rachel E; Galileo, Deni S; Martin-DeLeon, Patricia A

    2015-11-01

    Deletion of the gene encoding the widely conserved plasma membrane calcium ATPase 4 (PMCA4), a major Ca(2+) efflux pump, leads to loss of sperm motility and male infertility in mice. PMCA4's partners in sperm and how its absence exerts its effect on fertility are unknown. We hypothesize that in sperm PMCA4 interacts with endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) which are rapidly activated by Ca(2+), and that these fertility-modulating proteins are present in prostasomes, which deliver them to sperm. We show that in human sperm PMCA4 is present on the acrosome, inner acrosomal membrane, posterior head, neck, midpiece and the proximal principal piece. PMCA4 localization showed inter- and intra-individual variation and was most abundant at the posterior head/neck junction, co-localizing with NOSs. Co-immunoprecipitations (Co-IP) revealed a close association of PMCA4 and the NOSs in Ca(2+) ionophore-treated sperm but much less so in uncapacitated untreated sperm. Fluorescence resonance energy transfer (FRET) showed a similar Ca(2+)-related association: PMCA4 and the NOSs are within 10 nm apart, and preferentially so in capacitated, compared with uncapacitated, sperm. FRET efficiencies varied, being significantly (P < 0.001) higher at high cytosolic Ca(2+) concentration ([Ca(2+)]c) in capacitated sperm than at low [Ca(2+)]c in uncapacitated sperm for the PMCA4-eNOS complex. These dynamic interactions were not seen for PMCA4-nNOS complexes, which had the highest FRET efficiencies. Further, along with Ca(2+)/CaM-dependent serine kinase (CASK), PMCA4 and the NOSs are present in the seminal plasma, specifically in prostasomes where Co-IP showed complexes similar to those in sperm. Finally, flow cytometry demonstrated that following co-incubation of sperm and seminal plasma, PMCA4 and the NOSs can be delivered in vitro to sperm via prostasomes. Our findings indicate that PMCA4 interacts simultaneously with the NOSs preferentially at

  7. Alpha-CaMKII plays a critical role in determining the aggressive behavior of human osteosarcoma.

    Science.gov (United States)

    Daft, Paul G; Yuan, Kaiyu; Warram, Jason M; Klein, Michael J; Siegal, Gene P; Zayzafoon, Majd

    2013-04-01

    Osteosarcoma is among the most frequently occurring primary bone tumors, primarily affecting adolescents and young adults. Despite improvements in osteosarcoma treatment, more specific molecular targets are needed as potential therapeutic options. One target of interest is α-Ca(2+)/calmodulin-dependent protein kinase II (α-CaMKII), a ubiquitous mediator of Ca(2+)-linked signaling, which has been shown to regulate tumor cell proliferation and differentiation. Here, we investigate the role of α-CaMKII in the growth and tumorigenicity of human osteosarcoma. We show that α-CaMKII is highly expressed in primary osteosarcoma tissue derived from 114 patients, and is expressed in varying levels in different human osteosarcoma (OS) cell lines [MG-63, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)/HOS, and 143B). To examine whether α-CaMKII regulates osteosarcoma tumorigenic properties, we genetically inhibited α-CaMKII in two osteosarcoma cell lines using two different α-CaMKII shRNAs delivered by lentiviral vectors and overexpressed α-CaMKII by retrovirus. The genetic deletion of α-CaMKII by short hairpin RNA (shRNA) in MG-63 and 143B cells resulted in decreased proliferation (50% and 41%), migration (22% and 25%), and invasion (95% and 90%), respectively. The overexpression of α-CaMKII in HOS cells resulted in increased proliferation (240%), migration (640%), and invasion (10,000%). Furthermore, α-CaMKII deletion in MG-63 cells significantly reduced tumor burden in vivo (65%), whereas α-CaMKII overexpression resulted in tumor formation in a previously nontumor forming osteosarcoma cell line (HOS). Our results suggest that α-CaMKII plays a critical role in determining the aggressive phenotype of osteosarcoma, and its inhibition could be an attractive therapeutic target to combat this devastating adolescent disease. ©2013 AACR.

  8. Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

    DEFF Research Database (Denmark)

    Cheon, Seon Ah; Bal, Jyotiranjan; Song, Yunkyoung

    2012-01-01

    p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal...... growth in this organism under non-hypha-inducing conditions, suggesting that CaLag1p is necessary for relaying signals to induce hypha-specific gene expression. Analysis of ceramide and sphingolipid composition revealed that CaLag1p predominantly synthesizes ceramides with C24:0/C26:0 fatty acid moieties...

  9. Assessment of the diagnostic value of combined determination of serum CA199 CA125 and CEA in patients with cancer of pancreas

    International Nuclear Information System (INIS)

    Wu Congshan; Liu Xugui

    2005-01-01

    Objective: To assess the diagnostic value of combined determination of serum CA199, CA125 and CEA for cancer of pancreas. Methods: Serum CA199, CA125 and CEA levels were detected with CLIA in 32 patients with cancer of pancreas and 36 controls. Results: Positive detection rate of CA199 in patients with cancer of pancreas was 90.6% (29/32). Positive rate for CA125 and CEA was 65.6% (21/32) and 46.9% (15/32) respectively. With combined determination of these 3 tumor markers, the positive rate was 96.9% (31/32). The mean content of serum CA199 after successful operation (32.5±8.4U/ml) was significantly lower than that before operation (840.2 ± 102.5U/ml) (P<0.01). Conclusion: Combined determination of CA199, CA125 and CEA would improve the detection rate of cancer of pancreas and post-operative changes of CA199 could be of prognostic value. (authors)

  10. Consideration of the band-gap tunability of BaSi2 by alloying with Ca or Sr based on the electronic structure calculations

    International Nuclear Information System (INIS)

    Imai, Yoji; Watanabe, Akio

    2007-01-01

    The electronic structures and total energies of BaSi 2 -SrSi 2 and BaSi 2 -CaSi 2 systems have been calculated using the first-principle pseudopotential method to clarify the band gap tunability of BaSi 2 by alloying with Sr or Ca. From an energetic consideration of the compounds where all the Ba I sites or all the Ba II sites of the BaSi 2 lattice are preferentially replaced by Sr or Ca, it is expected that the Ba I site will be preferentially replaced by Sr rather than the Ba II sites. Compounds where all the Ba II sites are replaced by Sr or all the Ba II or all the Ba I sites are replaced by Ca are energetically unfavorable compared to the undissolved system of BaSi 2 and SrSi 2 or CaSi 2 . The effect of the addition of Sr or Ca into the BaSi 2 lattice on the gap value is different depending on the replaced sites of Ba. The replacement of Ba I site by Sr will broaden the band gap of BaSi 2 , which is consistent with the observed results

  11. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.7258 >orf19.7258; Contig19-2507; 88880..89851; DDI1*; response to DNA alkyl...ation; MQLTISLDHSGDIISVDVPDSLCLEDFKAYLSAETGLEASVQVLKFNGRELVGNATLSELQIHDNDLLQLSKKQVA

  12. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.1278 >orf19.1278; Contig19-10104; complement(13162...4..>132028); ; conserved hypothetical protein; truncated protein IQNNKCSGCNLKLDFPVIHFKCKHSFHQKCLSTNLIATSTESS

  13. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.4711 >orf19.4711; Contig19-10212; complement(29836...7..>300616); ; acidic repetitive protein; truncated protein DRSDYNEEDNNDFTRKLNEIQSKESNHEDLAQSEVQEGQKDEPDSVNQ

  14. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available ruitment factor; MAKTRSKSAATAAATSPKASPTAAKVTKNKVTKPSTASPSKTTKTKAVKKTTTKKATPKKEEEEKK... Ca19AnnotatedDec2004aaSeq orf19.124 >orf19.124; Contig19-10035; 67601..68698; CIC1*; protease substrate rec

  15. Ca-Dependent Folding of Human Calumenin

    Science.gov (United States)

    Mazzorana, Marco; Hussain, Rohanah; Sorensen, Thomas

    2016-01-01

    Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range. PMID:26991433

  16. Oxidized CaMKII causes cardiac sinus node dysfunction in mice

    OpenAIRE

    Swaminathan, Paari Dominic; Purohit, Anil; Soni, Siddarth; Voigt, Niels; Singh, Madhu V.; Glukhov, Alexey V.; Gao, Zhan; He, B. Julie; Luczak, Elizabeth D.; Joiner, Mei-ling A.; Kutschke, William; Yang, Jinying; Donahue, J. Kevin; Weiss, Robert M.; Grumbach, Isabella M.

    2011-01-01

    Sinus node dysfunction (SND) is a major public health problem that is associated with sudden cardiac death and requires surgical implantation of artificial pacemakers. However, little is known about the molecular and cellular mechanisms that cause SND. Most SND occurs in the setting of heart failure and hypertension, conditions that are marked by elevated circulating angiotensin II (Ang II) and increased oxidant stress. Here, we show that oxidized calmodulin kinase II (ox-CaMKII) is a biomark...

  17. Ca isotope fractionation and Sr/Ca partitioning associated with anhydrite formation at mid-ocean ridge hydrothermal systems: An experimental approach

    Science.gov (United States)

    Syverson, D. D.; Scheuermann, P.; Pester, N. J.; Higgins, J. A.; Seyfried, W. E., Jr.

    2016-12-01

    The elemental and isotopic mass balance of Ca and Sr between seawater and basalt at mid-ocean ridge (MOR) hydrothermal systems is an integrated reflection of the various physiochemical processes, which induce chemical exchange, in the subseafloor. Specifically, the processes of anhydrite precipitation and recrystallization are recognized to be important controls on governing the Ca and Sr elemental and isotope compositions of high temperature vent fluids, however, few experimental data exist to constrain these geochemical effects. Thus, to better understand the associated Sr/Ca partitioning and Ca isotope fractionation and rate of exchange between anhydrite and dissolved constituents, anhydrite precipitation and recrystallization experiments were performed at 175, 250, and 350°C and 500 bar at chemical conditions indicative of active MOR hydrothermal systems. The experimental data suggest that upon entrainment of seawater into MOR hydrothermal systems, anhydrite will precipitate rapidly and discriminate against the heavy isotopes of Ca (Δ44/40Ca(Anh-Fluid) = -0.68 - -0.25 ‰), whereas Sr/Ca partitioning depends on the saturation state of the evolving hydrothermal fluid with respect to anhydrite at each PTX (KD(Anh-Fluid) = 1.24 - 0.55). Coupling experimental constraints with the temperature gradient inferred for high temperature MOR hydrothermal systems in the oceanic crust, data suggest that the Ca isotope and Sr elemental composition of anhydrite formed near the seafloor will be influenced by disequilibrium effects, while, at higher temperatures further into the oceanic crust, anhydrite will be representative of equilibrium Sr/Ca partitioning and Ca isotope fractionation conditions. These experimental observations are consistent with analyzed Sr/Ca and Ca isotope compositions of anhydrites and vent fluids sampled from modern MOR hydrothermal systems1,2 and can be used to further constrain the geochemical effects of hydrothermal circulation in the oceanic crust

  18. Usefulness of CA 130 kit based on IRMA

    International Nuclear Information System (INIS)

    Fujii, Takashi; Kimura, Yoshiko; Ata, Mariko; Miyagawa, Naoko; Iio, Atsushi; Hamamoto, Ken

    1988-01-01

    Immunoradiometric assay for CA 130 was fundamentally and clinically evaluated using a commercially available D-7111 kit. Incubation time was 4 hr with the present CA 133 kit as compared with 16 - 24 hr with conventional CA 125 kit. Laboratory performance of CA 130 kit was satisfactory for standard curve, reproducibility, and recovery test. There was well correlation between the present CA 130 kit and CA 125 kit (r = 0.931). The concentration of CA 130 in the serum was significantly higher in healthy women than men (17.3 +- 10.5 U/ml vs 9.6 +- 5.1 U/ml). Serum CA 130 levels tended to decrease with aging, regardless of sex. These levels were changeable with menstrual cycle ; i.e., these were significantly higher during menstrual phase (24.2 +- 9.0 U/ml) and significantly lower during ovulatory phase (10.9 +- 2.4 U/ml) and during menopause (12.1 +- 3.4 U/ml). Cut off serum CA 130 levels were defined as 20 U/ml for men and 38 U/ml for women. Positive rate for CA 130 was the highest in cases of ovarian cancer (80 %), followed by endometrial cancer (50 %), pancreatic cancer (47 %), benign ovarian tumor (44 %), and lung cancer (39 %). (Namekawa, K.)

  19. How informative are spatial CA3 representations established by the dentate gyrus?

    Directory of Open Access Journals (Sweden)

    Erika Cerasti

    2010-04-01

    Full Text Available In the mammalian hippocampus, the dentate gyrus (DG is characterized by sparse and powerful unidirectional projections to CA3 pyramidal cells, the so-called mossy fibers. Mossy fiber synapses appear to duplicate, in terms of the information they convey, what CA3 cells already receive from entorhinal cortex layer II cells, which project both to the dentate gyrus and to CA3. Computational models of episodic memory have hypothesized that the function of the mossy fibers is to enforce a new, well-separated pattern of activity onto CA3 cells, to represent a new memory, prevailing over the interference produced by the traces of older memories already stored on CA3 recurrent collateral connections. Can this hypothesis apply also to spatial representations, as described by recent neurophysiological recordings in rats? To address this issue quantitatively, we estimate the amount of information DG can impart on a new CA3 pattern of spatial activity, using both mathematical analysis and computer simulations of a simplified model. We confirm that, also in the spatial case, the observed sparse connectivity and level of activity are most appropriate for driving memory storage-and not to initiate retrieval. Surprisingly, the model also indicates that even when DG codes just for space, much of the information it passes on to CA3 acquires a non-spatial and episodic character, akin to that of a random number generator. It is suggested that further hippocampal processing is required to make full spatial use of DG inputs.

  20. Ca 125 and Ca 19-9: two cancer-associated sialylsaccharide antigens on a mucus glycoprotein from human milk.

    Science.gov (United States)

    Hanisch, F G; Uhlenbruck, G; Dienst, C; Stottrop, M; Hippauf, E

    1985-06-03

    The cancer-associated antigens Ca 125 and Ca 19-9 were demonstrated by radioimmunoassay to form structural units of a mucus glycoprotein in human milk taken from healthy women four days after parturition. The glycoprotein precipitated with the casein fraction at pH 4.6 and was completely absent in the whey as judged from Ca 19-9 assay. It could be effectively enriched by phenol-saline extraction from soluble milk proteins and further purified by gel filtration on Sephacryl S300 and Sephacryl S400. The active component with a bouyant density of 1.41 g/ml in isopycnic density gradient centrifugation (CsCl) shared common physico-chemical and chemical characteristics of mucus glycoproteins. Carbohydrates representing about 68% by weight were conjugated to protein by alkali-labile linkages, exclusively and were essentially free of D-mannose. Activities of Ca 125 and Ca 19-9 were both destroyed by treatment with periodate, mild alkali or neuraminidase suggesting the antigens are sialylated saccharides bound to protein by alkali-labile linkages. The fraction of monosialylated saccharide alditols isolated after reductive beta-elimination from the mucus glycoprotein was shown to inhibit monoclonal antibodies anti-(Ca 125) and anti-(Ca 19-9) in radioimmunoassay.

  1. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.3361 >orf19.3361; Contig19-10173; 157397..>158185;... YAT2*; carnitine acetyltransferase; gene family | truncated protein MSTYRFQETLEKLPIPDLVQTCNAYLEALKPLQTEQEHE

  2. Metabolic Regulation of CaMKII Protein and Caspases in Xenopus laevis Egg Extracts*

    Science.gov (United States)

    McCoy, Francis; Darbandi, Rashid; Chen, Si-Ing; Eckard, Laura; Dodd, Keela; Jones, Kelly; Baucum, Anthony J.; Gibbons, Jennifer A.; Lin, Sue-Hwa; Colbran, Roger J.; Nutt, Leta K.

    2013-01-01

    The metabolism of the Xenopus laevis egg provides a cell survival signal. We found previously that increased carbon flux from glucose-6-phosphate (G6P) through the pentose phosphate pathway in egg extracts maintains NADPH levels and calcium/calmodulin regulated protein kinase II (CaMKII) activity to phosphorylate caspase 2 and suppress cell death pathways. Here we show that the addition of G6P to oocyte extracts inhibits the dephosphorylation/inactivation of CaMKII bound to caspase 2 by protein phosphatase 1. Thus, G6P sustains the phosphorylation of caspase 2 by CaMKII at Ser-135, preventing the induction of caspase 2-mediated apoptotic pathways. These findings expand our understanding of oocyte biology and clarify mechanisms underlying the metabolic regulation of CaMKII and apoptosis. Furthermore, these findings suggest novel approaches to disrupt the suppressive effects of the abnormal metabolism on cell death pathways. PMID:23400775

  3. Glu¹⁰⁶ in the Orai1 pore contributes to fast Ca²⁺-dependent inactivation and pH dependence of Ca²⁺ release-activated Ca²⁺ (CRAC) current.

    Science.gov (United States)

    Scrimgeour, Nathan R; Wilson, David P; Rychkov, Grigori Y

    2012-01-15

    FCDI (fast Ca²⁺-dependent inactivation) is a mechanism that limits Ca²⁺ entry through Ca²⁺ channels, including CRAC (Ca²⁺ release-activated Ca²⁺) channels. This phenomenon occurs when the Ca²⁺ concentration rises beyond a certain level in the vicinity of the intracellular mouth of the channel pore. In CRAC channels, several regions of the pore-forming protein Orai1, and STIM1 (stromal interaction molecule 1), the sarcoplasmic/endoplasmic reticulum Ca²⁺ sensor that communicates the Ca²⁺ load of the intracellular stores to Orai1, have been shown to regulate fast Ca²⁺-dependent inactivation. Although significant advances in unravelling the mechanisms of CRAC channel gating have occurred, the mechanisms regulating fast Ca²⁺-dependent inactivation in this channel are not well understood. We have identified that a pore mutation, E106D Orai1, changes the kinetics and voltage dependence of the ICRAC (CRAC current), and the selectivity of the Ca²⁺-binding site that regulates fast Ca²⁺-dependent inactivation, whereas the V102I and E190Q mutants when expressed at appropriate ratios with STIM1 have fast Ca²⁺-dependent inactivation similar to that of WT (wild-type) Orai1. Unexpectedly, the E106D mutation also changes the pH dependence of ICRAC. Unlike WT ICRAC, E106D-mediated current is not inhibited at low pH, but instead the block of Na⁺ permeation through the E106D Orai1 pore by Ca²⁺ is diminished. These results suggest that Glu¹⁰⁶ inside the CRAC channel pore is involved in co-ordinating the Ca²⁺-binding site that mediates fast Ca²⁺-dependent inactivation.

  4. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.4748 >orf19.4748; Contig19-10215; complement(47336.....47731); MSL1*; U2 snRNA-associated protein; MPSTKRSSSTEYSHKDSKKKVKLDYVNLKPSQTLYVKNLNTKINKKILLHNLYLLFSAFGDIISINLQNGFAFIIFSNLNSATLALRNLKNQDFFDKPLVLNYAVKESKAISQEKQKLQDENDEEVMPSYE*

  5. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.2370 >orf19.2370; Contig19-10147; complement(50671..52716); DSL1*; retrogra...de ER-to-golgi transport; MPSIEQQLEDQELYLKDIEQNINKTLSKINKTTLENDNDFRKQFEEIPQDSNTTESN

  6. Absolute Ca Isotopic Measurement Using an Improved Double Spike Technique

    Directory of Open Access Journals (Sweden)

    Jason Jiun-San Shen

    2009-01-01

    Full Text Available A new vector analytical method has been developed in order to obtain the true isotopic composition of the 42Ca-48Ca double spike. This is achieved by using two different sample-spike mixtures combined with the double spike and natural Ca data. Be cause the natural sample (two mixtures and the spike should all lie on a single mixing line, we are able to con strain the true isotopic composition of our double spike using this new approach. Once the isotopic composition of the Ca double spike is established, we are able to obtain the true Ca isotopic composition of the NIST Ca standard SRM915a, 40Ca/44Ca = 46.537 ± 2 (2sm, n = 55, 42Ca/44Ca = 0.31031 ± 1, 43Ca/44Ca = 0.06474 ± 1, and 48Ca/44Ca = 0.08956 ± 1. De spite an off set of 1.3% in 40Ca/44Ca between our result and the previously re ported value (Russell et al. 1978, our data indicate an off set of 1.89__in 40Ca/44Ca between SRM915a and seawater, entirely consistent with the published results.

  7. Clinical value of preoperative serum CA 19-9 and CA 125 levels in predicting the resectability of hilar cholangiocarcinoma.

    Science.gov (United States)

    Hu, Hai-Jie; Mao, Hui; Tan, Yong-Qiong; Shrestha, Anuj; Ma, Wen-Jie; Yang, Qin; Wang, Jun-Ke; Cheng, Nan-Sheng; Li, Fu-Yu

    2016-01-01

    To examine the predictive value of tumor markers for evaluating tumor resectability in patients with hilar cholangiocarcinoma and to explore the prognostic effect of various preoperative factors on resectability in patients with potentially resectable tumors. Patients with potentially resectable tumors judged by radiologic examination were included. The receiver operating characteristic (ROC) analysis was conducted to evaluate serum carbohydrate antigenic determinant 19-9 (CA 19-9), carbohydrate antigen 125 (CA 125) and carcino embryonie antigen levels on tumor resectability. Univariate and multivariate logistic regression models were also conducted to analysis the correlation of preoperative factors with resectability. In patients with normal bilirubin levels, ROC curve analysis calculated the ideal CA 19-9 cut-off value of 203.96 U/ml in prediction of resectability, with a sensitivity of 83.7 %, specificity of 80 %, positive predictive value of 91.1 % and negative predictive value of 66.7 %. Meanwhile, the optimal cut-off value for CA 125 to predict resectability was 25.905 U/ml (sensitivity, 78.6 %; specificity, 67.5 %). In a multivariate logistic regression model, tumor size ≤3 cm (OR 4.149, 95 % CI 1.326-12.981, P = 0.015), preoperative CA 19-9 level ≤200 U/ml (OR 20.324, 95 % CI 6.509-63.467, P hilar cholangiocarcinoma. Preoperative CA 19-9 and CA 125 levels predict resectability in patients with radiological resectable hilar cholangiocarcinoma. Increased preoperative CA 19-9 levels and CA 125 levels are associated with poor resectability rate.

  8. Mitochondrial Ca2+ overload underlies Abeta oligomers neurotoxicity providing an unexpected mechanism of neuroprotection by NSAIDs.

    Directory of Open Access Journals (Sweden)

    Sara Sanz-Blasco

    Full Text Available Dysregulation of intracellular Ca(2+ homeostasis may underlie amyloid beta peptide (Abeta toxicity in Alzheimer's Disease (AD but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+ in neurons and promote mitochondrial Ca(2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+ overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i mitochondrial Ca(2+ overload underlies the neurotoxicity induced by Abeta oligomers and ii inhibition of mitochondrial Ca(2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.

  9. Mitochondrial Ca2+ overload underlies Abeta oligomers neurotoxicity providing an unexpected mechanism of neuroprotection by NSAIDs.

    Science.gov (United States)

    Sanz-Blasco, Sara; Valero, Ruth A; Rodríguez-Crespo, Ignacio; Villalobos, Carlos; Núñez, Lucía

    2008-07-23

    Dysregulation of intracellular Ca(2+) homeostasis may underlie amyloid beta peptide (Abeta) toxicity in Alzheimer's Disease (AD) but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42) oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+) in neurons and promote mitochondrial Ca(2+) overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+) overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs) including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+) overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i) mitochondrial Ca(2+) overload underlies the neurotoxicity induced by Abeta oligomers and ii) inhibition of mitochondrial Ca(2+) overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.

  10. Ca{sup 2+}/calmodulin-dependent protein kinase phosphatase (CaMKP/PPM1F) interacts with neurofilament L and inhibits its filament association

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Hana [Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521 (Japan); Katoh, Tsuyoshi [Department of Biochemistry, Asahikawa Medical University, Asahikawa, 078-8510 (Japan); Nakagawa, Ryoko; Ishihara, Yasuhiro [Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521 (Japan); Sueyoshi, Noriyuki; Kameshita, Isamu [Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795 (Japan); Taniguchi, Takanobu [Department of Biochemistry, Asahikawa Medical University, Asahikawa, 078-8510 (Japan); Hirano, Tetsuo; Yamazaki, Takeshi [Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521 (Japan); Ishida, Atsuhiko, E-mail: aishida@hiroshima-u.ac.jp [Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521 (Japan)

    2016-09-02

    Ca{sup 2+}/calmodulin-dependent protein kinase phosphatase (CaMKP/PPM1F) is a Ser/Thr phosphatase that belongs to the PPM family. Growing evidence suggests that PPM phosphatases including CaMKP act as a complex with other proteins to regulate cellular functions. In this study, using the two-dimensional far-western blotting technique with digoxigenin-labeled CaMKP as a probe, in conjunction with peptide mass fingerprinting analysis, we identified neurofilament L (NFL) as a CaMKP-binding protein in a Triton-insoluble fraction of rat brain. We confirmed binding of fluorescein-labeled CaMKP (F-CaMKP) to NFL in solution by fluorescence polarization. The analysis showed that the dissociation constant of F-CaMKP for NFL is 73 ± 17 nM (n = 3). Co-immunoprecipitation assay using a cytosolic fraction of NGF-differentiated PC12 cells showed that endogenous CaMKP and NFL form a complex in cells. Furthermore, the effect of CaMKP on self-assembly of NFL was examined. Electron microscopy revealed that CaMKP markedly prevented NFL from forming large filamentous aggregates, suggesting that CaMKP-binding to NFL inhibits its filament association. These findings may provide new insights into a novel mechanism for regulating network formation of neurofilaments during neuronal differentiation. - Highlights: • NFL was identified as a CaMKP-binding protein in an insoluble fraction of rat brain. • CaMKP bound to NFL in solution with a K{sub d} value of 73 ± 17 nM. • A CaMKP-NFL complex was found in NGF-differentiated PC12 cells. • CaMKP-binding to NFL inhibited its filament association. • CaMKP may regulate network formation of neurofilaments in neurons.

  11. Quantum mechanics/molecular mechanics simulation of the ligand vibrations of the water-oxidizing Mn4CaO5 cluster in photosystem II.

    Science.gov (United States)

    Nakamura, Shin; Noguchi, Takumi

    2016-10-11

    During photosynthesis, the light-driven oxidation of water performed by photosystem II (PSII) provides electrons necessary to fix CO 2 , in turn supporting life on Earth by liberating molecular oxygen. Recent high-resolution X-ray images of PSII show that the water-oxidizing center (WOC) is composed of an Mn 4 CaO 5 cluster with six carboxylate, one imidazole, and four water ligands. FTIR difference spectroscopy has shown significant structural changes of the WOC during the S-state cycle of water oxidation, especially within carboxylate groups. However, the roles that these carboxylate groups play in water oxidation as well as how they should be properly assigned in spectra are unresolved. In this study, we performed a normal mode analysis of the WOC using the quantum mechanics/molecular mechanics (QM/MM) method to simulate FTIR difference spectra on the S 1 to S 2 transition in the carboxylate stretching region. By evaluating WOC models with different oxidation and protonation states, we determined that models of high-oxidation states, Mn(III) 2 Mn(IV) 2 , satisfactorily reproduced experimental spectra from intact and Ca-depleted PSII compared with low-oxidation models. It is further suggested that the carboxylate groups bridging Ca and Mn ions within this center tune the reactivity of water ligands bound to Ca by shifting charge via their π conjugation.

  12. Determination of 40Ca and 48Ca matter densities by 600 MeV and 1 GeV proton elastic scattering

    International Nuclear Information System (INIS)

    Brissaud, I.; Campi, X.

    1979-02-01

    The 600MeV and 1GeV data of proton elastic scattering on 40 Ca and 48 Ca have been analyzed in the framework of the Glauber model. The matter distributions are extracted from the data in an approximately model-independent form based on a Fourier series expansion. A similar method is used to deduce directly the 48 Ca- 40 Ca neutron density difference

  13. Multifaceted Roles of ALG-2 in Ca2+-Regulated Membrane Trafficking

    Directory of Open Access Journals (Sweden)

    Masatoshi Maki

    2016-08-01

    Full Text Available ALG-2 (gene name: PDCD6 is a penta-EF-hand Ca2+-binding protein and interacts with a variety of proteins in a Ca2+-dependent fashion. ALG-2 recognizes different types of identified motifs in Pro-rich regions by using different hydrophobic pockets, but other unknown modes of binding are also used for non-Pro-rich proteins. Most ALG-2-interacting proteins associate directly or indirectly with the plasma membrane or organelle membranes involving the endosomal sorting complex required for transport (ESCRT system, coat protein complex II (COPII-dependent ER-to-Golgi vesicular transport, and signal transduction from membrane receptors to downstream players. Binding of ALG-2 to targets may induce conformational change of the proteins. The ALG-2 dimer may also function as a Ca2+-dependent adaptor to bridge different partners and connect the subnetwork of interacting proteins.

  14. CORRELATION OF {sup 48}Ca, {sup 50}Ti, AND {sup 138}La HETEROGENEITY IN THE ALLENDE REFRACTORY INCLUSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Chen, Jiang-Chang, E-mail: hart.chen@bristol.ac.uk [Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, ROC (China)

    2015-06-10

    Precise determinations of {sup 48}Ca anomalies in Allende calcium–aluminum-rich inclusions (CAIs) are reported in this work. There are endemic positive {sup 48}Ca/{sup 44}Ca anomalies in all analyzed CAIs after normalization to {sup 42}Ca/{sup 44}Ca, and it is clearly shown that there is no simple correlation between {sup 48}Ca/{sup 44}Ca and {sup 50}Ti/{sup 48}Ti anomalies, in agreement with Jungck et al. Compared to the {sup 48}Ca/{sup 44}Ca versus {sup 50}Ti/{sup 48}Ti correlation line defined by differentiated meteorites, reported by Chen et al., the CAIs plot to elevated {sup 50}Ti/{sup 48}Ti. Assuming the {sup 48}Ca/{sup 44}Ca anomalies of both CAIs and differentiated meteorites came from the same source, excess {sup 50}Ti anomalies in CAIs can be calculated by subtracting the part associated with {sup 48}Ca/{sup 44}Ca. These excesses show a linear correlation with {sup 138}La anomalies, a neutrino-process nuclide. According to current stellar nucleosynthetic models, we therefore suggest that the solar system {sup 48}Ca, {sup 50}Ti, and {sup 138}La isotopic variations are made of mixtures between grains condensed from ejecta of neutron-rich accretion-induced SNe Ia and the O/Ne–O/C zone of core-collapse SNe II.

  15. Performance Characteristics of CA 19-9 Radioimmunoassay and Clinical Significance of Serum CA 19-9 Assay in Patients with Malignancy

    International Nuclear Information System (INIS)

    Kim, Sang Eun; Shong, Young Kee; Cho, Bo Youn; Kim, Noe Kyeong; Koh, Chang Soon; Lee, Mun Ho; Hong, Seong Woon; Hong, Kee Suk

    1985-01-01

    To evaluate the performance characteristics of CA 19-9 radioimmunoassay and the clinical significance of serum CA 19-9 assay in patients with malignancy, serum. CA 19-9 levels were measured by radioimmunoassay using monoclonal antibody in 135 normal controls, 81 patients with various untreated malignancy, 9 patients of postoperative colon cancer without recurrence and 20 patients with benign gastrointestinal diseases, who visited Seoul National University Hospital from June, 1984 to March, 1985. The results were as follows; 1) The CA 19-9 radioimmunoassay was simple to perform and can be completed in one work day. And the between-assay reproducibility and the assay recovery were both excellent. 2) The mean serum CA 19-9 level in 135 normal controls was 8.4±4.2 U/mL. Normal upper limit of serum CA 19-9 was defined as 21.0 U/mL. 4 out of 135 (3.0%) normal controls showed elevated CA 19-9 levels above the normal upper limit. 3) One out of 20 (5.0%) patients with benign gastrointestinal diseases showed elevated serum CA 19-9 level above the normal upper limit. 4) In 81 patients with various untreated malignancy, 41 patients (50.6%) showed elevated serum CA 19-9 levels. 66.7% of 18 patients with colorectal cancer, 100% of 2 patients with pancreatic cancer, 100% of 3 patients with common bile duct cancer, 47.1% of 17 patients with stomach cancer, 28.6% of 28 patients with hepatoma and 60.0% of 5 gastrointestinal tract cancers showed elevated serum CA 19-9 levels. 5) The sensitivities of serum CA 19-9 related to respectability in colorectal and stomach cancer were 33.3% in resectable colorectal cancer, 83.3% in unresectable colorectal cancer, 41.7% in resectable stomach cancer, 60.0% in unresectable stomach cancer respectively. 6) The sensitivity of serum CA 19-9 in 9 patients of postoperative colorectal cancer without recurrence were 33.3% and significantly decreased compared with that of untreated colorectal cancer, 66.7% (p<0.05). 7) In Patients with colorectal cancer

  16. ORF Sequence: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.710 >orf19.710; Contig19-10065; complement(47186.....>47710); LSC2*; succinate-CoA ligase beta subunit; truncated protein | overlap LGFDDNASFRQEEVFSWRDPTQEDPQEAE

  17. Hydriding and dehydriding properties of CaSi

    International Nuclear Information System (INIS)

    Aoki, Masakazu; Ohba, Nobuko; Noritake, Tatsuo; Towata, Shin-ichi

    2005-01-01

    The hydriding and dehydriding properties of CaSi were investigated both theoretically and experimentally. First-principles calculations suggested that CaSiH n is thermodynamically stable. Experimentally, the p -c isotherms clearly demonstrated plateau pressures in a temperature range of 473-573 K and the maximum hydrogen content was 1.9 weight % (wt.%) under a hydrogen pressure of 9 MPa at 473 K. The structure of CaSiH n is different from those of ZrNi hydrides, although CaSi has the CrB-type structure as well as ZrNi

  18. Novel method of generation of Ca(HCO32 and CaCO3 aerosols and first determination of hygroscopic and cloud condensation nuclei activation properties

    Directory of Open Access Journals (Sweden)

    A. Trimborn

    2010-09-01

    Full Text Available Atmospheric mineral aerosols contain CaCO3 as a reactive component. A novel method to produce CaCO3 aerosol was developed by spraying Ca(HCO32 solution, which was generated from a CaCO3 suspension and CO2. By aerosol mass spectrometry the freshly sprayed and dried aerosol was characterized to consist of pure Ca(HCO32 which under annealing in a tube furnace transformed into CaCO3. Transmission Electron Microscopy demonstrated that the particles produced were spherical. The method was able to generate aerosol of sufficient concentration and proper size for the study of physiochemical properties and investigations of heterogeneous reactions of mineral aerosol. The dried Ca(HCO32 particles were somewhat more hygroscopic than CaCO3 particles. However, during humidification a restructuring took place and ∼2/3 of the Ca(HCO32 was transformed to CaCO3. The mixed Ca(HCO32/CaCO3(s particles were insoluble with a growth factor of 1.03 at 95% (hygroscopicity parameter κ=0.011±0.007 relative humidity. This compares to a corresponding growth factor of 1.01 for CaCO3(s (κ=0.0016±0.0004. Mass spectrometric composition analysis, restructuring, and insolubility of the mixed particles suggested that solid Ca(HCO32(s was observed. This would be in contrast to the current belief that Ca(HCO32(s is thermodynamically instable. The CCN activity of Ca(HCO32(s aerosol (κ≈0.15 is remarkably higher than that of CaCO3 aerosol (κ=0.0019±0.0007 and less than that of Ca(NO32. The noticeable but limited solubility of Ca(HCO32 of ≈0.01 mol/l explains limited hygroscopic growth and good CCN activity. Experiments in the Large Jülich Aerosol Chamber indicated that Ca(HCO32(s could exist for several hours under dry atmospheric conditions. However, it was likely buried in a protective layer of CaCO3(s. We conclude that Ca(HCO32 may be formed in the atmosphere in cloud droplets of activated mineral dust by reaction of CaCO3 with CO2 and H2O. The presence of Ca(HCO32 and

  19. Cardiac microvascular endothelial cells express a functional Ca+ -sensing receptor.

    Science.gov (United States)

    Berra Romani, Roberto; Raqeeb, Abdul; Laforenza, Umberto; Scaffino, Manuela Federica; Moccia, Francesco; Avelino-Cruz, Josè Everardo; Oldani, Amanda; Coltrini, Daniela; Milesi, Veronica; Taglietti, Vanni; Tanzi, Franco

    2009-01-01

    The mechanism whereby extracellular Ca(2+) exerts the endothelium-dependent control of vascular tone is still unclear. In this study, we assessed whether cardiac microvascular endothelial cells (CMEC) express a functional extracellular Ca(2+)-sensing receptor (CaSR) using a variety of techniques. CaSR mRNA was detected using RT-PCR, and CaSR protein was identified by immunocytochemical analysis. In order to assess the functionality of the receptor, CMEC were loaded with the Ca(2+)-sensitive fluorochrome, Fura-2/AM. A number of CaSR agonists, such as spermine, Gd(3+), La(3+) and neomycin, elicited a heterogeneous intracellular Ca(2+) signal, which was abolished by disruption of inositol 1,4,5-trisphosphate (InsP(3)) signaling and by depletion of intracellular stores with cyclopiazonic acid. The inhibition of the Na(+)/Ca(2+) exchanger upon substitution of extracellular Na(+) unmasked the Ca(2+) signal triggered by an increase in extracellular Ca(2+) levels. Finally, aromatic amino acids, which function as allosteric activators of CaSR, potentiated the Ca(2+) response to the CaSR agonist La(3+). These data provide evidence that CMEC express CaSR, which is able to respond to physiological agonists by mobilizing Ca(2+) from intracellular InsP(3)-sensitive stores. Copyright 2008 S. Karger AG, Basel.

  20. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    NARCIS (Netherlands)

    Eilers, W.; Gevers, W.; van Overbeek, D.; de Haan, A.; Jaspers, R.T.; Hilbers, P.A.; van Riel, A.C.R.; Flueck, M.

    2014-01-01

    We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII) contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its

  1. Transgenic up-regulation of alpha-CaMKII in forebrain leads to increased anxiety-like behaviors and aggression

    Directory of Open Access Journals (Sweden)

    Hasegawa Shunsuke

    2009-03-01

    Full Text Available Abstract Background Previous studies have demonstrated essential roles for alpha-calcium/calmodulin-dependent protein kinase II (alpha-CaMKII in learning, memory and long-term potentiation (LTP. However, previous studies have also shown that alpha-CaMKII (+/- heterozygous knockout mice display a dramatic decrease in anxiety-like and fearful behaviors, and an increase in defensive aggression. These findings indicated that alpha-CaMKII is important not only for learning and memory but also for emotional behaviors. In this study, to understand the roles of alpha-CaMKII in emotional behavior, we generated transgenic mice overexpressing alpha-CaMKII in the forebrain and analyzed their behavioral phenotypes. Results We generated transgenic mice overexpressing alpha-CaMKII in the forebrain under the control of the alpha-CaMKII promoter. In contrast to alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in anxiety-like behaviors in open field, elevated zero maze, light-dark transition and social interaction tests, and a decrease in locomotor activity in their home cages and novel environments; these phenotypes were the opposite to those observed in alpha-CaMKII (+/- heterozygous knockout mice. In addition, similarly with alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in aggression. However, in contrast to the increase in defensive aggression observed in alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in offensive aggression. Conclusion Up-regulation of alpha-CaMKII expression in the forebrain leads to an increase in anxiety-like behaviors and offensive aggression. From the comparisons with previous findings, we suggest that the expression levels of alpha-CaMKII are associated with the state of emotion; the expression level of alpha-CaMKII positively correlates with the anxiety state and strongly affects

  2. Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 : Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra

    NARCIS (Netherlands)

    Marashdeh, A.; Frankcombe, T.J.

    2008-01-01

    The dehydrogenation enthalpies of Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski’s direct method. The

  3. Structure, stability, and thermomechanical properties of Ca-substituted Pr2NiO4 + δ

    Science.gov (United States)

    Pikalova, E. Yu.; Medvedev, D. A.; Khasanov, A. F.

    2017-04-01

    Ca-substituted layered nickelates with a general Pr2- x Ca x NiO4 + δ composition ( x = 0-0.7, Δ x = 0.1) were prepared in the present work and their structural and physic-chemical properties were investigated in order to select the most optimal materials, which can be used as cathodes for solid oxide fuel cells. With an increase in Ca content in Pr2- x Ca x NiO4 + δ the following tendencies were observed: (i) a decrease in the concentration of nonstoichiometric oxygen (δ), (ii) a decrease in the unit cell parameters and volume, (iii) stabilization of the tetragonal structure, (iv) a decrease of the thermal expansion coefficients, and (v) enchancement of thermodynamic stability and compatibility with selected oxygen- and proton-conducting electrolytes. The Pr1.9Ca0.1NiO4 + δ material, having highest δ value, departs from the general "properties-composition" dependences ascertained. This indicates that oxygen non-stoichiometry has determining influence on the functional properties of layered nickelates.

  4. Basic and clinical evaluation of CA 130 RIA kit (D-7111) using two newly developed monoclonal antibodies. Comparison with CA 125 kit

    Energy Technology Data Exchange (ETDEWEB)

    Saga, Tsuneo; Endo, Keigo; Nakajima, Tetsuo and others

    1988-10-01

    The CA 130 RIA kit was developed with the use of two monoclonal antibodies, 130 - 22 and 145 - 9. Laboratory performance was satisfactory for precision, reproducibility, recovery, and dilution. Measurement values with CA 130 kit were almost consistent with those with CA 125 kit. Favorable standard curves were attained with smaller concentrations and shorter incubation time of CA 130 kit than those with CA 125 kit. There was less prozone phenomenon. When defining a cut-off serum level of CA 130 as 35 U/ml, false-positive rate was 0 % for healthy men and 4 % for healthy women, suggesting the involvement of menstrual cycle. Positive rate for CA 130 was 65 % for malignant ovarian tumor, 48 % for lung cancer, and 47 % for endometriosis. (Namekawa, K.).

  5. Break-up of Ca-montmorillonite particles by Na-montmorillonite

    International Nuclear Information System (INIS)

    Hedstroem, Magnus; Birgersson, Martin

    2012-01-01

    Document available in extended abstract form only. In the Swedish KBS-3 concept for a geological deep storage of spent nuclear fuel, bentonite of high montmorillonite content is proposed to serve as a buffer surrounding copper canisters containing the spent fuel. Montmorillonite has an exceptional affinity for water which results in the build-up of a swelling pressure when bentonite is placed in a confined volume. However, there is a concern that during and after a glaciation, meltwater of low ionic strength may cause the bentonite to swell extensively into fractures and turn into a sol that could be transported away by the seeping water. It is thus warranted to understand the behaviour of montmorillonite at aqueous condition of low ionic strength. Turbidity measurements were used to a large extent in previous work to follow the free swelling or settling process of montmorillonite in various aqueous solutions and thereby give information regarding sol formation. From theory we know that turbidity of a suspension is proportional to the particle concentration. However turbidity is also proportional to V p 2 where V p is the volume of the scattering particle. Thus the fact that turbidity of a Ca-montmorillonite suspension is higher than the turbidity of a Na- montmorillonite suspension of the same clay concentration indicates that Na-montmorillonite separate into smaller particles than Ca-montmorillonite. In this work we make use this size dependence to quantify the difference between Wyoming, Milos and Kutch montmorillonite in particular with respect to how mixed Ca/Na montmorillonite systems behave. Some Ca/Mg, Mg/Na and Na/K systems are also included for comparison. Figure 1 shows the final (stabilized) turbidity response of mixed Wy-Ca/Na montmorillonite as a function of the fraction of Ca 2+ in the clay. Starting material are suspensions of homo-ionic Wy-Ca and Wy-Na montmorillonite at a concentration of 1 g/l. The turbidity of the suspensions of the homo

  6. Sustained increase of spontaneous input and spike transfer in the CA3-CA1 pathway following long term potentiation in vivo

    Directory of Open Access Journals (Sweden)

    Oscar eHerreras

    2012-10-01

    Full Text Available Long term potentiation (LTP is commonly used to study synaptic plasticity but the associated changes in the spontaneous activity of individual neurons or the computational properties of neural networks in vivo remain largely unclear. The multisynaptic origin of spontaneous spikes makes difficult estimating the impact of a particular potentiated input. Accordingly, we adopted an approach that isolates pathway-specific postsynaptic activity from raw local field potentials (LFPs in the rat hippocampus in order to study the effects of LTP on ongoing spike transfer between cell pairs in the CA3-CA1 pathway. CA1 Schaffer-specific LFPs elicited by spontaneous clustered firing of CA3 pyramidal cells involved a regular succession of elementary micro-field-EPSPs (gamma-frequency that fired spikes in CA1 units. LTP increased the amplitude but not the frequency of these ongoing excitatory quanta. Also, the proportion of Schaffer-driven spikes in both CA1 pyramidal cells and interneurons increased in a cell-specific manner only in previously connected CA3-CA1 cell pairs, i.e., when the CA3 pyramidal cell had shown pre-LTP significant correlation with firing of a CA1 unit and potentiated spike-triggered average of Schaffer LFPs following LTP. Moreover, LTP produced subtle reorganization of presynaptic CA3 cell assemblies. These findings show effective enhancement of pathway specific ongoing activity which leads to increased spike transfer in potentiated segments of a network. These indicate that plastic phenomena induced by external protocols may intensify spontaneous information flow across specific channels as proposed in transsynaptic propagation of plasticity and synfire chain hypotheses that may be the substrate for different types of memory involving multiple brain structures.

  7. The hippocampal CA2 ensemble is sensitive to contextual change.

    Science.gov (United States)

    Wintzer, Marie E; Boehringer, Roman; Polygalov, Denis; McHugh, Thomas J

    2014-02-19

    Contextual learning involves associating cues with an environment and relating them to past experience. Previous data indicate functional specialization within the hippocampal circuit: the dentate gyrus (DG) is crucial for discriminating similar contexts, whereas CA3 is required for associative encoding and recall. Here, we used Arc/H1a catFISH imaging to address the contribution of the largely overlooked CA2 region to contextual learning by comparing ensemble codes across CA3, CA2, and CA1 in mice exposed to familiar, altered, and novel contexts. Further, to manipulate the quality of information arriving in CA2 we used two hippocampal mutant mouse lines, CA3-NR1 KOs and DG-NR1 KOs, that result in hippocampal CA3 neuronal activity that is uncoupled from the animal's sensory environment. Our data reveal largely coherent responses across the CA axis in control mice in purely novel or familiar contexts; however, in the mutant mice subject to these protocols the CA2 response becomes uncoupled from CA1 and CA3. Moreover, we show in wild-type mice that the CA2 ensemble is more sensitive than CA1 and CA3 to small changes in overall context. Our data suggest that CA2 may be tuned to remap in response to any conflict between stored and current experience.

  8. Control theory-based regulation of hippocampal CA1 nonlinear dynamics.

    Science.gov (United States)

    Hsiao, Min-Chi; Song, Dong; Berger, Theodore W

    2008-01-01

    We are developing a biomimetic electronic neural prosthesis to replace regions of the hippocampal brain area that have been damaged by disease or insult. Our previous study has shown that the VLSI implementation of a CA3 nonlinear dynamic model can functionally replace the CA3 subregion of the hippocampal slice. As a result, the propagation of temporal patterns of activity from DG-->VLSI-->CA1 reproduces the activity observed experimentally in the biological DG-->CA3-->CA1 circuit. In this project, we incorporate an open-loop controller to optimize the output (CA1) response. Specifically, we seek to optimize the stimulation signal to CA1 using a predictive dentate gyrus (DG)-CA1 nonlinear model (i.e., DG-CA1 trajectory model) and a CA1 input-output model (i.e., CA1 plant model), such that the ultimate CA1 response (i.e., desired output) can be first predicted by the DG-CA1 trajectory model and then transformed to the desired stimulation through the inversed CA1 plant model. Lastly, the desired CA1 output is evoked by the estimated optimal stimulation. This study will be the first stage of formulating an integrated modeling-control strategy for the hippocampal neural prosthetic system.

  9. High-pressure synthesis and structural, physical properties of CaIr1-xPtxO3 and CaIr1-xRhxO3

    Science.gov (United States)

    Hirai, S.; Bromiley, G. D.; Klemme, S.; Irifune, T.; Ohfuji, H.; Attfield, P.; Nishiyama, N.

    2010-12-01

    Since the discovery of the perovskite to post-perovskite transition in MgSiO3 in a laser-heated DAC, wide attention has been focussed on the post-perovskite phase of MgSiO3. This is because the post-perovskite phase is likely to play a key role in Earth’s lowermost mantle, and because the perovskite to post-perovskite transition can explain many features of the D” seismic discontinuity. While it is meaningful to conduct further studies of MgSiO3, the post-perovskite phase of MgSiO3 cannot be quenched to ambient pressure/temperature conditions. Thus, further studies must be conducted using analogue compounds of MgSiO3 post-perovskite, which are quenchable to ambient pressure/temperature conditions. The post-perovskite phase of MgSiO3 crystallizes in a layered structure with CaIrO3-structure. Therefore, it is useful to investigate compounds with CaIrO3-structure. There are only four quenchable oxides with CaIrO3-structure reported to date: CaIrO3, CaPtO3, CaRhO3 and CaRuO3. CaIrO3 can be synthesized at ambient pressure, whilst the other three oxides can only be obtained at high pressure/temperature conditions using a multi-anvil apparatus. Further studies on these materials have revealed structural phase transitions at high P-T and a metal-insulator transition by hole doping. In the case of CaIrO3, The post-perovskite phase of CaIrO3 synthesized at 2GPa, 1373K transforms into a perovskite phase at 2GPa, 1673K. In other words, the perovskite phase can be synthesized at temperatures higher than those needed for synthesizing the post-perovskite phase. This is also the case for CaRhO3 (6GPa, 1873K) and CaRuO3 (23GPa, 1343K), while CaPtO3 remained post-perovskite at higher temperatures. We have succeeded in synthesizing solid solutions between CaIrO3, CaPtO3 and CaRhO3. We have found the systematic change in structural and physical properties of post-perovskite oxides, with composition and P-T, which broadens the future opportunity for studying post-perovskite systems

  10. Properties of Ca2+ release induced by clofibric acid from the sarcoplasmic reticulum of mouse skeletal muscle fibres

    Science.gov (United States)

    Ikemoto, Takaaki; Endo, Makoto

    2001-01-01

    To characterize the effect of clofibric acid (Clof) on the Ca2+ release mechanism in the sarcoplasmic reticulum (SR) of skeletal muscle, we analysed the properties of Clof-induced Ca2+ release under various conditions using chemically skinned skeletal muscle fibres of the mouse.Clof (>0.5 mM) released Ca2+ from the SR under Ca2+-free conditions buffered with 10 mM EGTA (pCa >8).Co-application of ryanodine and Clof at pCa >8 but not ryanodine alone reduced the Ca2+ uptake capacity of the SR. Thus, Ca2+ release induced by Clof at pCa >8 must be a result of the activation of the ryanodine receptor (RyR).At pCa >8, (i) Clof-induced Ca2+ release was inhibited by adenosine monophosphate (AMP), (ii) the inhibitory effect of Mg2+ on the Clof-induced Ca2+ release was saturated at about 1 mM, and (iii) Clof-induced Ca2+ release was not inhibited by procaine (10 mM). These results indicate that Clof may activate the RyR-Ca2+ release channels in a manner different from Ca2+-induced Ca2+ release (CICR).In addition to this unique mode of opening, Clof also enhanced the CICR mode of opening of RyR-Ca2+ release channels.Apart from CICR, a high concentration of Ca2+ might also enhance the unique mode of opening by Clof.These results suggest that some features of Ca2+ release activated by Clof are similar to those of physiological Ca2+ release (PCR) in living muscle cells and raise the possibility that Clof may be useful in elucidating the mechanism of PCR in skeletal muscle. PMID:11606311

  11. A Strategy for Synthesizing CaZnOS:Eu{sup 2+} Phosphor and Comparison of Optical Properties with CaS:Eu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Zhongxian; Rong, Chunying; Zhou, Wenli; Zhang, Jilin; Li, Chengzhi; Yu, Liping; Liu, Shubin; Lian, Shixun, E-mail: shixunlian@gmail.com

    2014-01-15

    Graphical abstract: Pure-phase CaZnOS:Eu{sup 2+},Ce{sup 3+}phosphor with good chemical and thermal stability can be synthesized by co-doping with Ce{sup 3+} as deoxidizer rather than reduction atmosphere. The broad bluish-green excitation and broad red emission show it is a better phosphor than CaS:Eu{sup 2+} for white LED and for sunlight harvesting of plants. -- Highlights: • Pure-phase phosphor CaZnOS:Eu{sup 2+} was synthesized by co-doping with Ce{sup 3+} as deoxidizer. • Energy transfer mechanism from Ce{sup 3+} to Eu{sup 2+} in CaZnOS host is proposed. • CaZnOS:Eu{sup 2+}, Ce{sup 3+} phosphor has good chemical and thermal stability performance. • The similarities and differences between CaZnOS:Eu{sup 2+} and CaS:Eu{sup 2+} were analyzed. • The green excitation and red emission show superior solar harvesting for plants. -- Abstract: The red-emitting phosphor CaZnOS:Eu{sup 2+} was synthesized from CaCO{sub 3}, ZnS, Eu{sub 2}O{sub 3} and CeCl{sub 3} by controlling the sintering condition. It was found that Ce{sup 3+} ions can play a role of reductant to contribute to the formation of Eu{sup 2+} in CaZnOS matrix under inert protective atmosphere. While the gas flow changed to H{sub 2}/N{sub 2}, the product turned to CaS easily. XRD, photoluminescence spectra, UV–vis and IR absorption spectra were evaluated to investigate the origin of the distinctions of the optical properties and stabilities between the two divalent europium ions doped phosphors CaZnOS:Eu{sup 2+} and CaS:Eu{sup 2+}. The similarities and differences between them were analyzed.

  12. Effects of vitamin D metabolites on cellular Ca2+ and on Ca transport in primary cultures of bone cells.

    Science.gov (United States)

    Eilam, Y; Szydel, N; Harell, A

    1980-09-01

    Both 1,25-dihydroxycholecalciferol (1,25(OH)2D3) and 24,25-dihydroxycholecalciferol (24,25(OH)2D3) exerted direct effects on Ca2+ transport and accumulation in primary cultures of bone cells. The following changes were recorded. (1) A significant decrease in the amount of intracellular exchangeable Ca2+. (2) A marked increase in the rate constants of efflux from the 'slow'-turnover intracellular Ca pool. (3) A marked increase in the 'initial rate' of Ca influx into the cells. Thus, vitamin D metabolites caused an increase in the turnover of Ca2+ in bone cells and altered the steady-stae level of intracellular exchangeable Ca2+. Whereas the changes in the rate of efflux were abolished in the presence of inhibitors of protein synthesis, the increase in the rate of influx was not sensitive to these inhibitors. It is suggested that the changes in the two fluxes were mediated by different mechanisms and that the changes in influx were due to a direct effect of vitamin D metabolites on the cellular membranes.

  13. Modeling the Onset of Phase Separation in CaO-SiO2-CaCl2 Chlorine-Containing Silicate Glasses.

    Science.gov (United States)

    Swansbury, Laura A; Mountjoy, Gavin; Chen, Xiaojing; Karpukhina, Natalia; Hill, Robert

    2017-06-08

    The addition of chlorine into a bioactive glass composition is expected to reduce its abrasiveness and increase its bioactivity, which is important for dental applications such as toothpastes. There is a lack of information and understanding regarding the structural role of chlorine in chlorine-containing bioactive silicate glasses. This has prompted classical core-shell model molecular dynamics simulations of (50 - x/2)CaO-(50 - x/2)SiO 2 -xCaCl 2 glasses to be performed, where x ranges from x = 0.0 to 43.1 mol % CaCl 2 . These ternary glasses are advantageous for a fundamental study because they do not have additional network formers (e.g., phosphorus pentoxide) or modifiers (e.g., sodium) typically found in bioactive glass compositions. The (50 - x/2)CaO-(50 - x/2)SiO 2 -xCaCl 2 glasses were seen to become phase-separated around the x = 16.1 mol % CaCl 2 composition, and chlorine predominantly coordinated with calcium. These findings provide a solid foundation for further computational modeling work on more complex chlorine-containing bioactive glass compositions.

  14. caCORE: a common infrastructure for cancer informatics.

    Science.gov (United States)

    Covitz, Peter A; Hartel, Frank; Schaefer, Carl; De Coronado, Sherri; Fragoso, Gilberto; Sahni, Himanso; Gustafson, Scott; Buetow, Kenneth H

    2003-12-12

    Sites with substantive bioinformatics operations are challenged to build data processing and delivery infrastructure that provides reliable access and enables data integration. Locally generated data must be processed and stored such that relationships to external data sources can be presented. Consistency and comparability across data sets requires annotation with controlled vocabularies and, further, metadata standards for data representation. Programmatic access to the processed data should be supported to ensure the maximum possible value is extracted. Confronted with these challenges at the National Cancer Institute Center for Bioinformatics, we decided to develop a robust infrastructure for data management and integration that supports advanced biomedical applications. We have developed an interconnected set of software and services called caCORE. Enterprise Vocabulary Services (EVS) provide controlled vocabulary, dictionary and thesaurus services. The Cancer Data Standards Repository (caDSR) provides a metadata registry for common data elements. Cancer Bioinformatics Infrastructure Objects (caBIO) implements an object-oriented model of the biomedical domain and provides Java, Simple Object Access Protocol and HTTP-XML application programming interfaces. caCORE has been used to develop scientific applications that bring together data from distinct genomic and clinical science sources. caCORE downloads and web interfaces can be accessed from links on the caCORE web site (http://ncicb.nci.nih.gov/core). caBIO software is distributed under an open source license that permits unrestricted academic and commercial use. Vocabulary and metadata content in the EVS and caDSR, respectively, is similarly unrestricted, and is available through web applications and FTP downloads. http://ncicb.nci.nih.gov/core/publications contains links to the caBIO 1.0 class diagram and the caCORE 1.0 Technical Guide, which provide detailed information on the present caCORE architecture

  15. Clinical significance of determination of changes of serum CA153, CA125 and TSGF levels after operation in patients with breast cancer

    International Nuclear Information System (INIS)

    Zhou Jun; Wang Zhaoxin; Wang Yan; Wang Rui

    2007-01-01

    Objective: To study the clinical significance of changes serum CA153, CA125 and TSGF levels after operation in patients with breast cancer. Methods: Serum CA153, CA125 and TSGF (with RIA) and serum TSGF levels (with biochemistry method) were measured in 36 patients with breast cancer both before and after operation as well as in 35 controls. Results: Before operation, serum levels of serum CA153, CA125 and TSGF in the patients were significantly higher than those in the controls (P < 0.01 ). One month after operation, all the levels were approaching normal. Six months later, the levels in the patients without recurrence remained normal, however, the levels in the 4 patients with recurrence returned to those before operation again. Conclusion: Changes of serum CA153, CA125 and TSGF levels are closely related to the tumor burden and if levels were high after operation, may indicate the presence of recurrence. (authors)

  16. Caffeine-Induced Ca2+ Oscillations in Type I Horizontal Cells of the Carp Retina and the Contribution of the Store-Operated Ca2+ Entry Pathway

    Science.gov (United States)

    Lv, Ting; Gong, Hai-Qing; Liang, Pei-Ji

    2014-01-01

    The mechanisms of release, depletion, and refilling of endoplasmic reticulum (ER) Ca2+ were investigated in type I horizontal cells of the carp retina using a fluo-3-based Ca2+ imaging technique. Exogenous application of caffeine, a ryanodine receptor agonist, induced oscillatory intracellular free Ca2+ concentration ([Ca2+]i) responses in a duration- and concentration-dependent manner. In Ca2+-free Ringer’s solution, [Ca2+]i transients could also be induced by a brief caffeine application, whereas subsequent caffeine application induced no [Ca2+]i increase, which implied that extracellular Ca2+ was required for ER refilling, confirming the necessity of a Ca2+ influx pathway for ER refilling. Depletion of ER Ca2+ by thapsigargin triggered a Ca2+ influx which could be blocked by the store-operated channel inhibitor 2-APB, which proved the existence of the store-operated Ca2+ entry pathway. Taken together, these results suggested that after being depleted by caffeine, the ER was replenished by Ca2+ influx via store-operated channels. These results reveal the fine modulation of ER Ca2+ signaling, and the activation of the store-operated Ca2+ entry pathway guarantees the replenishment of the ER so that the cell can be ready for response to the subsequent stimulus. PMID:24918937

  17. Synaptotagmin-7 is a principal Ca2+ sensor for Ca2+ -induced glucagon exocytosis in pancreas

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wei, Shun-Hui; Hoang, Dong Nhut

    2009-01-01

    Hormones such as glucagon are secreted by Ca(2+)-induced exocytosis of large dense-core vesicles, but the mechanisms involved have only been partially elucidated. Studies of pancreatic beta-cells secreting insulin revealed that synaptotagmin-7 alone is not sufficient to mediate Ca(2+)-dependent i...

  18. Apo-states of calmodulin and CaBP1 control CaV1 voltage-gated calcium channel function through direct competition for the IQ domain

    Science.gov (United States)

    Findeisen, Felix; Rumpf, Christine; Minor, Daniel L.

    2013-01-01

    In neurons, binding of calmodulin (CaM) or calcium-binding protein 1 (CaBP1) to the CaV1 (L-type) voltage-gated calcium channel IQ domain endows the channel with diametrically opposed properties. CaM causes calcium-dependent inactivation (CDI) and limits calcium entry, whereas CaBP1 blocks CDI and allows sustained calcium influx. Here, we combine isothermal titration calorimetry (ITC) with cell-based functional measurements and mathematical modeling to show that these calcium sensors behave in a competitive manner that is explained quantitatively by their apo-state binding affinities for the IQ domain. This competition can be completely blocked by covalent tethering of CaM to the channel. Further, we show that Ca2+/CaM has a sub-picomolar affinity for the IQ domain that is achieved without drastic alteration of calcium binding properties. The observation that the apo-forms of CaM and CaBP1 compete with each other demonstrates a simple mechanism for direct modulation of CaV1 function and suggests a means by which excitable cells may dynamically tune CaV activity. PMID:23811053

  19. Apo states of calmodulin and CaBP1 control CaV1 voltage-gated calcium channel function through direct competition for the IQ domain.

    Science.gov (United States)

    Findeisen, Felix; Rumpf, Christine H; Minor, Daniel L

    2013-09-09

    In neurons, binding of calmodulin (CaM) or calcium-binding protein 1 (CaBP1) to the CaV1 (L-type) voltage-gated calcium channel IQ domain endows the channel with diametrically opposed properties. CaM causes calcium-dependent inactivation and limits calcium entry, whereas CaBP1 blocks calcium-dependent inactivation (CDI) and allows sustained calcium influx. Here, we combine isothermal titration calorimetry with cell-based functional measurements and mathematical modeling to show that these calcium sensors behave in a competitive manner that is explained quantitatively by their apo-state binding affinities for the IQ domain. This competition can be completely blocked by covalent tethering of CaM to the channel. Further, we show that Ca(2+)/CaM has a sub-picomolar affinity for the IQ domain that is achieved without drastic alteration of calcium-binding properties. The observation that the apo forms of CaM and CaBP1 compete with each other demonstrates a simple mechanism for direct modulation of CaV1 function and suggests a means by which excitable cells may dynamically tune CaV activity. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Dendrochronologically dated pine stumps document phase-wise bog expansion at a northwest German site between ca. 6700 and ca. 3400 BC

    Science.gov (United States)

    Maike Achterberg, Inke Elisabeth; Eckstein, Jan; Birkholz, Bernhard; Bauerochse, Andreas; Leuschner, Hanns Hubert

    2018-01-01

    The investigated northwest German mire site at Totes Moor is densely covered with subfossil pine stumps (Pinus sylvestris L.) from the fen-bog transition. This facilitates the spatio-temporal reconstruction of mire development, which is based on 212 in situ tree stumps in the case study presented here. Six dendrochronologically dated site chronologies together cover 2345 years between 6703 and 3403 BC. The gaps in between are 6 to 550 years long. Additionally, a floating chronology of 309 years, containing 30 trees, was radiocarbon-dated to the beginning of the 7th millennium cal BC. Peat-stratigraphical survey was carried out additionally, and elevations a.s.l. were determined at several locations. Tree dying-off phases, which indicate water level rise at the site, mostly in context of the local fen-bog transition, are evident for ca. 6600-6450, ca. 6350-5750, ca. 5300-4900, ca. 4700-4550, ca. 3900-3850, ca. 3700-3600, ca. 3500-3450 and ca. 3400 BC. The spatial distribution of the dated in situ trees illustrates the phase-wise expansion of raised bog over fen peat at the site. The documented bog expansion pulses likely correspond to climatic wet sifts.

  1. Efeitos de relações CaSO4/CaCO3 na mobilidade de nutrientes no solo e no crescimento do algodoeiro

    Directory of Open Access Journals (Sweden)

    A. A. Silva

    1998-09-01

    Full Text Available O experimento, realizado em casa de vegetação no Departamento de Ciência do Solo da Universidade Federal de Lavras, teve por objetivo estudar o efeito de diferentes relações de CaSO4/CaCO3, que simulam o uso de gesso e calcário, na movimentação de nutrientes no solo e no crescimento do algodoeiro, cultivar IAC-20. As proporções de CaSO4/CaCO3 utilizadas foram: 0/100, 25/75, 50/50, 75/25 e 100/0, com base em peso equivalente, além de um tratamento-testemunha, sem aplicação de CaSO4 e CaCO3. Observou-se acentuada movimentação de cálcio e de sulfato em profundidade, como íons acompanhantes, com o aumento da relação CaSO4/CaCO3. Para o N-NO3- e Mg2+, ao contrário do N-NH4+ e K+, observou-se um acúmulo em profundidade, com a elevação da relação CaSO4/CaCO3. Neste estudo, o gesso teve pouco ou nenhum efeito sobre a acidez e Al trocável presentes nas camadas subsuperficiais. A produção de matéria seca do algodoeiro foi reduzida com o aumento da relação CaSO4/CaCO3, porém, quando comparada à do tratamento-testemunha, a aplicação de gesso aumentou-a significativamente, atestando o potencial de uso do gesso agrícola.

  2. Synaptically evoked Ca2+ release from intracellular stores is not influenced by vesicular zinc in CA3 hippocampal pyramidal neurones.

    Science.gov (United States)

    Evstratova, Alesya; Tóth, Katalin

    2011-12-01

    The co-release of neuromodulatory substances in combination with classic neurotransmitters such as glutamate and GABA from individual presynaptic nerve terminals has the capacity to dramatically influence synaptic efficacy and plasticity. At hippocampal mossy fibre synapses vesicular zinc is suggested to serve as a cotransmitter capable of regulating calcium release from internal stores in postsynaptic CA3 pyramidal cells. Here we investigated this possibility using combined intracellular ratiometric calcium imaging and patch-clamp recording techniques. In acute hippocampal slices a brief train of mossy fibre stimulation produced a large, delayed postsynaptic Ca(2+) wave that was spatially restricted to the proximal apical dendrites of CA3 pyramidal cells within stratum lucidum. This calcium increase was sensitive to intracellularly applied heparin indicating reliance upon release from internal stores and was triggered by activation of both group I metabotropic glutamate and NMDA receptors. Importantly, treatment of slices with the membrane-impermeant zinc chelator CaEDTA did not influence the synaptically evoked postsynaptic Ca(2+) waves. Moreover, mossy fibre stimulus evoked postsynaptic Ca(2+) signals were not significantly different between wild-type and zinc transporter 3 (ZnT3) knock-out animals. Considered together our data do not support a role for vesicular zinc in regulating mossy fibre evoked Ca(2+) release from CA3 pyramidal cell internal stores.

  3. Combined detection of preoperative serum CEA, CA19-9 and CA242 improve prognostic prediction of surgically treated colorectal cancer patients.

    Science.gov (United States)

    Wang, Jingtao; Wang, Xiao; Yu, Fudong; Chen, Jian; Zhao, Senlin; Zhang, Dongyuan; Yu, Yang; Liu, Xisheng; Tang, Huamei; Peng, Zhihai

    2015-01-01

    We assessed the prognostic significance of preoperative serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 242 (CA242) levels in surgically treated colorectal cancer patients. The relationship of preoperative serum CEA, CA19-9 and CA242 levels with disease characteristics was investigated in 310 patients. Correlation between tumor markers was investigated using Pearson correlation test. Univariate and multivariate survival analyses were used to study the relationship between preoperative tumor markers and prognosis [disease free survival (DFS) and overall survival (OS)]. Kaplan-Meier analysis with log rank test was used to assess the impact of tumor marker levels on survival. Positive rate of preoperative serum CEA, CA19-9 and CA242 were 54.84%, 47.42% and 37.10%, respectively. High preoperative CEA level was associated with tumor size (P = 0.038), T stage (P tumor AJCC stage (P = 0.023). Preoperative CA242 positively correlated with CEA (P markers was of independent prognostic value in CRC (HR = 2.532, 95% CI: 1.400-4.579, P = 0.002 for OS; and HR = 2.366, 95% CI: 1.334-4.196, P = 0.003 for DFS). Combined detection of preoperative serum CEA, CA19-9 and CA242 is of independent prognostic value for management of CRC patients treated surgically.

  4. DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

    Science.gov (United States)

    Yang, Yu-Mi; Park, Soonhong; Ji, Hyewon; Kim, Tae-Im; Kim, Eung Kweon; Kang, Kyung Koo; Shin, Dong Min

    2014-04-01

    DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

  5. Age-dependent changes in diastolic Ca2+ and Na+ concentrations in dystrophic cardiomyopathy: Role of Ca2+ entry and IP3

    International Nuclear Information System (INIS)

    Mijares, Alfredo; Altamirano, Francisco; Kolster, Juan; Adams, José A.; López, José R.

    2014-01-01

    Highlights: • Age-dependent increase in [Ca 2+ ] d and [Na + ] d in mdx cardiomyocytes. • Gadolinium significantly reduced both [Ca 2+ ] d and [Na + ] d at all ages. • IP 3 -pathway inhibition reduced cations concentrations in dystrophic cardiomyocytes. - Abstract: Duchenne muscular dystrophy (DMD) is a lethal X-inherited disease caused by dystrophin deficiency. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with a dilated cardiomyopathy that leads to progressive heart failure at the end of the second decade. The aim of the present study was to characterize the diastolic Ca 2+ concentration ([Ca 2+ ] d ) and diastolic Na + concentration ([Na + ] d ) abnormalities in cardiomyocytes isolated from 3-, 6-, 9-, and 12-month old mdx mice using ion-selective microelectrodes. In addition, the contributions of gadolinium (Gd 3+ )-sensitive Ca 2+ entry and inositol triphosphate (IP 3 ) signaling pathways in abnormal [Ca 2+ ] d and [Na + ] d were investigated. Our results showed an age-dependent increase in both [Ca 2+ ] d and [Na + ] d in dystrophic cardiomyocytes compared to those isolated from age-matched wt mice. Gd 3+ treatment significantly reduced both [Ca 2+ ] d and [Na + ] d at all ages. In addition, blockade of the IP 3 -pathway with either U-73122 or xestospongin C significantly reduced ion concentrations in dystrophic cardiomyocytes. Co-treatment with U-73122 and Gd 3+ normalized both [Ca 2+ ] d and [Na + ] d at all ages in dystrophic cardiomyocytes. These data showed that loss of dystrophin in mdx cardiomyocytes produced an age-dependent intracellular Ca 2+ and Na + overload mediated at least in part by enhanced Ca 2+ entry through Gd 3+ sensitive transient receptor potential channels (TRPC), and by IP 3 receptors

  6. Molecular cloning of the large subunit of the high-Ca2+-requiring form of human Ca2+-activated neutral protease

    International Nuclear Information System (INIS)

    Imajoh, Shinobu; Aoki, Kazumasa; Ohno, Shigeo; Emori, Yasufumi; Kawasaki, Hiroshi; Sugihara, Hidemitsu; Suzuki, Koichi

    1988-01-01

    A nearly full-length cDNA clone for the large subunit of high-Ca 2+ -requiring Ca 2+ -activated neutral protease (mCANP) from human tissues has been isolated. The deduced protein, determined for the first time as an mCANP, has essentially the same structural features as those revealed previously for the large subunits of the low-Ca 2+ -requiring form (μCANP). Namely, the protein, comprising 700 amino acid residues, is characterized by four domains, containing a cysteine protease like domain and a Ca 2+ -binding domain. The overall amino acid sequence similarities of the mCANP large subunit with those of human μCANP and chicken CANP are 62% and 66%, respectively. These values are slightly lower than that observed between μCANP and chicken CANP (70%). Local sequence similarities vary with the domain, 73-78% in the cysteine protease like domain and 48-65% in the Ca 2+ -binding domain. These results suggest that CANPs with different Ca 2+ sensitivities share a common evolutionary origin and that their regulatory mechanisms are similar except for the Ca 2+ concentrations required for activation

  7. Effect of carbonation temperature on CO_2 adsorption capacity of CaO derived from micro/nanostructured aragonite CaCO_3

    International Nuclear Information System (INIS)

    Hlaing, Nwe Ni; Sreekantan, Srimala; Hinode, Hirofumi; Kurniawan, Winarto; Thant, Aye Aye; Othman, Radzali; Mohamed, Abdul Rahman; Salime, Chris

    2016-01-01

    Recent years, CaO-based synthetic materials have been attracted attention as potential adsorbents for CO_2 capture mainly due to their high CO_2 adsorption capacity. In this study, micro/nanostructured aragonite CaCO_3 was synthesized by a simple hydrothermal method with using polyacrylamide (PAM). The structural, morphological and thermal properties of the synthesized sample were investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and thermogravimetry analysis (TG-DTA). The XRD and FESEM results showed that the obtained sample was aragonite CaCO_3 with aggregated nanorods and microspheres composed of nanorods. A TG-DTA apparatus with Thermoplus 2 software was used to investigate the effect of carbonation temperature on the CO_2 adsorption capacity of CaO derived from aragonite CaCO_3 sample. At 300 °C, the sample reached the CO_2 adsorption capacity of 0.098 g-CO_2/g-adsorbent, whereas the sample achieved the highest capacity of 0.682 g-CO_2/g-adsorbent at 700 °C. The results showed that the carbonation temperature significantly influenced on the CO_2 adsorption capacity of the CaO derived from aragonite CaCO_3.

  8. Oxidative stress activates the TRPM2-Ca2+-CaMKII-ROS signaling loop to induce cell death in cancer cells.

    Science.gov (United States)

    Wang, Qian; Huang, Lihong; Yue, Jianbo

    2017-06-01

    High intracellular levels of reactive oxygen species (ROS) cause oxidative stress that results in numerous pathologies, including cell death. Transient potential receptor melastatin-2 (TRPM2), a Ca 2+ -permeable cation channel, is mainly activated by intracellular adenosine diphosphate ribose (ADPR) in response to oxidative stress. Here we studied the role and mechanisms of TRPM2-mediated Ca 2+ influx on oxidative stress-induced cell death in cancer cells. We found that oxidative stress activated the TRPM2-Ca 2+ -CaMKII cascade to inhibit early autophagy induction, which ultimately led to cell death in TRPM2 expressing cancer cells. On the other hand, TRPM2 knockdown switched cells from cell death to autophagy for survival in response to oxidative stress. Moreover, we found that oxidative stress activated the TRPM2-CaMKII cascade to further induce intracellular ROS production, which led to mitochondria fragmentation and loss of mitochondrial membrane potential. In summary, our data demonstrated that oxidative stress activates the TRPM2-Ca 2+ -CaMKII-ROS signal loop to inhibit autophagy and induce cell death. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Autophosphorylation of [alpha]CaMKII is Differentially Involved in New Learning and Unlearning Mechanisms of Memory Extinction

    Science.gov (United States)

    Kimura, Ryoichi; Silva, Alcino J.; Ohno, Masuo

    2008-01-01

    Accumulating evidence indicates the key role of [alpha]-calcium/calmodulin-dependent protein kinase II ([alpha]CaMKII) in synaptic plasticity and learning, but it remains unclear how this kinase participates in the processing of memory extinction. Here, we investigated the mechanism by which [alpha]CaMKII may mediate extinction by using…

  10. Serum CA 125, carcinoembryonic antigen, and CA 19-9 as tumor markers in borderline ovarian tumors

    NARCIS (Netherlands)

    Engelen, MJA; de Bruijn, HWA; Hollema, H; ten Koor, KA; Willemse, PHB; Aalders, JG; van der Zee, AGJ

    Objectives. The goals of this study were to analyze preoperative serum levels of CA 125, carcinoembryonic antigen (CEA), and CA 19-9 in patients with borderline ovarian tumors and to investigate if routine assessment of these markers in follow-up may lead to earlier detection of recurrence. Methods.

  11. Compound effect of CaCO3 and CaSO4·2H2O on the strength of steel slag: cement binding materials

    International Nuclear Information System (INIS)

    Qi, Liqian; Liu, Jiaxiang; Liu, Qian

    2016-01-01

    In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO 3 and CaSO 4 ·2H 2 O were added. This was done to study the compound effect of CaCO 3 and CaSO 4 ·2H 2 O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO 3 and CaSO 4 ·2H 2 O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO 3 and CaSO 4 ·2H 2 O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO 3 could accelerate the hydration of C 3 S. In addition, CaCO 3 was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO 4 ·2H 2 O could increase the number of AFt. The compound effect of CaCO 3 and CaSO 4 ·2H 2 O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior. (author)

  12. Radioimmunoassay studies of intestinal calcium-binding protein in the pig. II. The distribution of intestinal CaBP in pig tissues

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, B M; Kuttner, M; Willis, D M; Hitchman, A J.W.; Harrison, J E; Murray, T M [Toronto Univ., Ontario (Canada). Dept. of Medicine

    1975-12-01

    Using a specific radioimmunoassay for porcine intestinal calcium-binding protein (CaBP), we have measured the concentration of CaBP in the various tissues and organs of normal pigs. Intestinal CaBP was present in highest concentration in the upper small intestine, with lower concentrations in the distal small intestine. Intestinal CaBP was also found, in lower concentrations, in kidney, liver, thyroid, pancreas, and blood. In all other tissues, including parathyroid, bone, skeletal muscle, and brain, CaBP immunoreactivity was undetectable or less than in blood. The elution profile of calcium-binding activity and immunoreactivity from gel filtration analysis of kidney and parathyroid extracts suggest that the calcium-binding protein in the parathyroid gland, and the major calcium-binding protein(s) in the kidney, are chemically and immunochemically different from intestinal CaBP.

  13. Pathways for Energization of Ca in Mercury's Exosphere

    Science.gov (United States)

    Killen, Rosemary M.

    2015-01-01

    We investigate the possible pathways to produce the extreme energy observed in the calcium exosphere of Mercury. Any mechanism must explain the facts that Ca in Mercury's exosphere is extremely hot, that it is seen almost exclusively on the dawnside of the planet, and that its content varies seasonally, not sporadically. Simple diatomic molecules or their clusters are considered, focusing on calcium oxides while acknowledging that Ca sulfides may also be the precursor molecules. We first discuss impact vaporization to justify the assumption that CaO and Ca-oxide clusters are expected from impacts on Mercury. Then we discuss processes by which the atomic Ca is energized to a 70,000 K gas. The processes considered are (1) electron-impact dissociation of CaO molecules, (2) spontaneous dissociation of Ca-bearing molecules following impact vaporization, (3) shock-induced dissociative ionization, (4) photodissociation and (5) sputtering. We conclude that electron-impact dissociation cannot produce the required abundance of Ca, and sputtering cannot reproduce the observed spatial and temporal variation that is measured. Spontaneous dissociation is unlikely to result in the high energy that is seen. Of the two remaining processes, shock induced dissociative ionization produces the required energy and comes close to producing the required abundance, but rates are highly dependent on the incoming velocity distribution of the impactors. Photodissociation probably can produce the required abundance of Ca, but simulations show that photodissociation cannot reproduce the observed spatial distribution.

  14. Sr/Ca and Mg/Ca in Glycymeris glycymeris (Bivalvia) shells from the Iberian upwelling system: Ontogeny and environmental control

    Science.gov (United States)

    Freitas, Pedro; Richardson, Christopher; Chenery, Simon; Monteiro, Carlos; Butler, Paul; Reynolds, David; Scourse, James; Gaspar, Miguel

    2017-04-01

    Bivalve shells have a great potential as high-resolution geochemical proxy archives of marine environmental conditions. In addition, sclerochronology of long-lived bivalve species (e.g. Arctica islandica) provides a timeline of absolutely dated shell material for geochemical analysis that can extend into the past beyond the lifetime of single individuals through the use of replicated crossmatched centennial to millennial chronologies. However, the interpretation of such records remains extremely challenging and complex, with multiple environmental and biological processes affecting element incorporation in the shell (e.g. crystal fabrics, organic matrix, biomineralization mechanisms and physiological processes). As a result, the effective use of bivalve shell elemental/Ca ratios as palaeoenvironmental proxies has been limited, often to species-specific applications or applications restricted to particular environmental settings. The dog-cockle, Glycymeris glycymeris, is a relatively long-lived bivalve (up to 200 years) that occurs in coarse-grained subtidal sediments of coastal shelf seas of Europe and North West Africa. Glycymeris glycymeris shells provide a valuable, albeit not fully explored, archive to reconstruct past environmental variability in an area lacking sclerochronological studies due to the rarity of long-lived bivalves and lack of coral reefs. In this study, we evaluate the potential of Sr/Ca and Mg/Ca ratios in G. glycymeris shells as geochemical proxies of upwelling conditions in the Iberian Upwelling System, the northern section of the Canary Current Eastern Boundary Upwelling System. Sr/Ca and Mg/Ca generally co-varied significantly and a clear ontogenetic, non-environmental related change in Sr/Ca and Ba/Ca variability was observed. High Sr/Ca and Mg/Ca ratios in older shells (> 10 years old) were found to be associated with the occurrence of growth lines deposited during the winter reduction in shell growth. Nevertheless, Sr/Ca and Mg/Ca

  15. Automated analysis of calcium spiking profiles with CaSA software: two case studies from root-microbe symbioses.

    Science.gov (United States)

    Russo, Giulia; Spinella, Salvatore; Sciacca, Eva; Bonfante, Paola; Genre, Andrea

    2013-12-26

    Repeated oscillations in intracellular calcium (Ca2+) concentration, known as Ca2+ spiking signals, have been described in plants for a limited number of cellular responses to biotic or abiotic stimuli and most notably the common symbiotic signaling pathway (CSSP) which mediates the recognition by their plant hosts of two endosymbiotic microbes, arbuscular mycorrhizal (AM) fungi and nitrogen fixing rhizobia. The detailed analysis of the complexity and variability of the Ca2+ spiking patterns which have been revealed in recent studies requires both extensive datasets and sophisticated statistical tools. As a contribution, we have developed automated Ca2+ spiking analysis (CaSA) software that performs i) automated peak detection, ii) statistical analyses based on the detected peaks, iii) autocorrelation analysis of peak-to-peak intervals to highlight major traits in the spiking pattern.We have evaluated CaSA in two experimental studies. In the first, CaSA highlighted unpredicted differences in the spiking patterns induced in Medicago truncatula root epidermal cells by exudates of the AM fungus Gigaspora margarita as a function of the phosphate concentration in the growth medium of both host and fungus. In the second study we compared the spiking patterns triggered by either AM fungal or rhizobial symbiotic signals. CaSA revealed the existence of different patterns in signal periodicity, which are thought to contribute to the so-called Ca2+ signature. We therefore propose CaSA as a useful tool for characterizing oscillatory biological phenomena such as Ca2+ spiking.

  16. SNL/CA Environmental Management System Program Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Barbara L.

    2007-04-01

    The Sandia National Laboratories, California (SNL/CA) Environmental Management System (EMS) Program Manual documents the elements of the site EMS Program. The SNL/CA EMS Program conforms to the International Standard on Environmental Management Systems, ISO 14001:2004. Elements of the ISO standard overlap with those of Department of Energy (DOE) Order 450.1, thus SNL/CA's EMS program also meets the DOE requirements.

  17. Vibrational spectroscopic study of poldervaartite CaCa[SiO3(OH)(OH)

    Science.gov (United States)

    Frost, Ray L.; López, Andrés; Scholz, Ricardo; Lima, Rosa Malena Fernandes

    2015-02-01

    We have studied the mineral poldervaartite CaCa[SiO3(OH)(OH)] which forms a series with its manganese analogue olmiite CaMn[SiO3(OH)](OH) using a range of techniques including scanning electron microscopy, thermogravimetric analysis, Raman and infrared spectroscopy. Chemical analysis shows the mineral is reasonably pure and contains only calcium and manganese with low amounts of Al and F. Thermogravimetric analysis proves the mineral decomposes at 485 °C with a mass loss of 7.6% compared with the theoretical mass loss of 7.7%. A strong Raman band at 852 cm-1 is assigned to the SiO stretching vibration of the SiO3(OH) units. Two Raman bands at 914 and 953 cm-1 are attributed to the antisymmetric vibrations. Intense prominent peaks observed at 3487, 3502, 3509, 3521 and 3547 cm-1 are assigned to the OH stretching vibration of the SiO3(OH) units. The observation of multiple OH bands supports the concept of the non-equivalence of the OH units. Vibrational spectroscopy enables a detailed assessment of the molecular structure of poldervaartite.

  18. Regulation of the voltage-gated Ca2+ channel CaVα2δ-1 subunit expression by the transcription factor Egr-1.

    Science.gov (United States)

    González-Ramírez, Ricardo; Martínez-Hernández, Elizabeth; Sandoval, Alejandro; Gómez-Mora, Kimberly; Felix, Ricardo

    2018-04-23

    It is well known that the Ca V α 2 δ auxiliary subunit regulates the density of high voltage-activated Ca 2+ channels in the plasma membrane and that alterations in their functional expression might have implications in the pathophysiology of diverse human diseases such as neuropathic pain. However, little is known concerning the transcriptional regulation of this protein. We previously characterized the promoter of Ca V α 2 δ, and here we report its regulation by the transcription factor Egr-1. Using the neuroblastoma N1E-115 cells, we found that Egr-1 interacts specifically with its binding site in the promoter, affecting the transcriptional regulation of Ca V α 2 δ. Overexpression and knockdown analysis of Egr-1 showed significant changes in the transcriptional activity of the Ca V α 2 δ promoter. Egr-1 also regulated the expression of Ca V α 2 δ at the level of protein. Also, functional studies showed that Egr-1 knockdown significantly decreases Ca 2+ currents in dorsal root ganglion (DRG) neurons, while overexpression of the transcription factor increased Ca 2+ currents in the F11 cell line, a hybrid of DRG and N18TG2 neuroblastoma cells. Studying the effects of Egr-1 on the transcriptional expression of Ca V α 2 δ could help to understand the regulatory mechanisms of this protein in both health and disease. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Purinergic receptors stimulate Na+/Ca2+ exchange in pancreatic duct cells: possible role of proteins handling and transporting Ca2+

    DEFF Research Database (Denmark)

    Hansen, Mette R; Krabbe, Simon; Ankorina-Stark, Ieva

    2009-01-01

    ). Since NCX can also be connected with epithelial Ca(2+) transport, we also investigated expression of some Ca(2+)-handling/transporting proteins. Expression analysis revealed that pancreatic ducts of rat and human duct cell line CFPAC-1 (also PANC-1 and Capan-1) express the Na(+)/Ca(2+) exchanger (splice...

  20. Possibility of adjusting the photoluminescence spectrum of Ca scheelites to the emission spectrum of incandescent lamps: [ nCaWO4-(1- n)CaMoO4]: Eu3+ solid solutions

    Science.gov (United States)

    Bakovets, V. V.; Zolotova, E. S.; Antonova, O. V.; Korol'kov, I. V.; Yushina, I. V.

    2016-12-01

    The specific features of the photoluminescence of [ nCaWO4-(1- n)CaMoO4]:Eu3+ solid solutions with the scheelite structure are examined using X-ray phase analysis and photoluminescence, Raman scattering, and diffuse reflectance spectroscopy. The studied features are associated with a change in the long- and short-range orders of the crystal lattice upon variations in the composition of solutions in the range n = 0-1.0 (with a pitch of 0.2) at a concentration of red photoluminescence activator Eu3+ of 2 mol %. The mechanism of the modification of photoluminescence of solid solutions upon variations in their composition has been discussed. Anomalies in the variations in parameters of the crystal lattice, its short-range order, and luminescence spectra have been observed in the transition from pure compounds CaMoO4:Eu3+ and CaWO4:Eu3+ to solutions; the concentration of Eu3+ ions in the centrosymmetric localization increases (decreases) in the transition from the molybdate (tungstate). It has been demonstrated that the spectral radiant emittance of solid solution [0.4CaWO4-0.6CaMoO4]:Eu3+ (2 mol %) is the closest to that of an incandescent lamp.

  1. Novel Approach for the Remediation of Radioactive Cesium Contaminated Soil with nano-Fe/Ca/CaO Dispersion Mixture in Dry Condition

    Directory of Open Access Journals (Sweden)

    Mallampati S. R.

    2013-04-01

    Full Text Available Present study, first time we developed a nano-Fe/Ca/CaO dispersion mixture based remediation and volume reduction method of real radioactive cesium contaminated soils. After soil samples treated with 10wt% of nano-Fe/Ca/CaO dispersion mixtures, emitting radiation intensity was reduced from 4.00 μSv/h to 0.95 μSv/h in non-magnetic fraction soils. While, after treatment, about 30wt% magnetic and 70wt% nonmagnetic fraction soils were separated, and it’s condensed radioactive cesium concentration was about 80% and 20%, respectively. By this way, cesium contaminated soil volume can be reduced. These preliminary results appear to be very promising and the simple mixing with the addition of nano-Fe/Ca/CaO may be considered potentially applicable for the remediation and separation of radioactive Cs contaminated soil in dry conditions.

  2. Association of Plages with Sunspots: A Multi-Wavelength Study Using Kodaikanal Ca ii K and Greenwich Sunspot Area Data

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Sudip; Chatterjee, Subhamoy; Banerjee, Dipankar, E-mail: sudip@iiap.res.in [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India)

    2017-02-01

    Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 Å). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of plages are also similar to those of sunspots. Different area thresholdings on the “butterfly diagram” reveal that plages of area ≥4 arcmin{sup 2} are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.

  3. Simultaneous decontamination of cross-polluted soils with heavy metals and PCBs using a nano-metallic Ca/CaO dispersion mixture.

    Science.gov (United States)

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

    2014-01-01

    In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95-99% of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97%), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

  4. Calsequestrin content and SERCA determine normal and maximal Ca2+ storage levels in sarcoplasmic reticulum of fast- and slow-twitch fibres of rat.

    Science.gov (United States)

    Murphy, Robyn M; Larkins, Noni T; Mollica, Janelle P; Beard, Nicole A; Lamb, Graham D

    2009-01-15

    Whilst calsequestrin (CSQ) is widely recognized as the primary Ca2+ buffer in the sarcoplasmic reticulum (SR) in skeletal muscle fibres, its total buffering capacity and importance have come into question. This study quantified the absolute amount of CSQ isoform 1 (CSQ1, the primary isoform) present in rat extensor digitorum longus (EDL) and soleus fibres, and related this to their endogenous and maximal SR Ca2+ content. Using Western blotting, the entire constituents of minute samples of muscle homogenates or segments of individual muscle fibres were compared with known amounts of purified CSQ1. The fidelity of the analysis was proven by examining the relative signal intensity when mixing muscle samples and purified CSQ1. The CSQ1 contents of EDL fibres, almost exclusively type II fibres, and soleus type I fibres [SOL (I)] were, respectively, 36 +/- 2 and 10 +/- 1 micromol (l fibre volume)(-1), quantitatively accounting for the maximal SR Ca2+ content of each. Soleus type II [SOL (II)] fibres (approximately 20% of soleus fibres) had an intermediate amount of CSQ1. Every SOL (I) fibre examined also contained some CSQ isoform 2 (CSQ2), which was absent in every EDL and other type II fibre except for trace amounts in one case. Every EDL and other type II fibre had a high density of SERCA1, the fast-twitch muscle sarco(endo)plasmic reticulum Ca2+-ATPase isoform, whereas there was virtually no SERCA1 in any SOL (I) fibre. Maximal SR Ca2+ content measured in skinned fibres increased with CSQ1 content, and the ratio of endogenous to maximal Ca2+ content was inversely correlated with CSQ1 content. The relative SR Ca2+ content that could be maintained in resting cytoplasmic conditions was found to be much lower in EDL fibres than in SOL (I) fibres (approximately 20 versus >60%). Leakage of Ca2+ from the SR in EDL fibres could be substantially reduced with a SR Ca2+ pump blocker and increased by adding creatine to buffer cytoplasmic [ADP] at a higher level, both results

  5. Changes in functioning of rat submandibular salivary gland under streptozotocin-induced diabetes are associated with alterations of Ca2+ signaling and Ca2+ transporting pumps.

    Science.gov (United States)

    Fedirko, N V; Kruglikov, I A; Kopach, O V; Vats, J A; Kostyuk, P G; Voitenko, N V

    2006-03-01

    Xerostomia and pathological thirst are troublesome complications of diabetes mellitus associated with impaired functioning of salivary glands; however, their cellular mechanisms are not yet determined. Isolated acinar cells were loaded with Ca2+ indicators fura-2/AM for measuring cytosolic Ca2+ concentration ([Ca2+]i) or mag-fura-2/AM-inside the endoplasmic reticulum (ER). We found a dramatic decrease in pilocarpine-stimulated saliva flow, protein content and amylase activity in rats after 6 weeks of diabetes vs. healthy animals. This was accompanied with rise in resting [Ca2+]i and increased potency of acetylcholine (ACh) and carbachol (CCh) but not norepinephrine (NE) to induce [Ca2+]i transients in acinar cells from diabetic animals. However, [Ca2+]i transients mediated by Ca2+ release from ER stores (induced by application of either ACh, CCh, NE, or ionomycin in Ca2+-free extracellular medium) were decreased under diabetes. Application of inositol-1,4,5-trisphosphate led to smaller Ca2+ release from ER under the diabetes. Both plasmalemma and ER Ca2+-ATPases activity was reduced and the latter showed the increased affinity to ATP under the diabetes. We conclude that the diabetes caused impairment of salivary cells functions that, on the cellular level, associates with Ca2+ overload, increased Ca2+-mobilizing ability of muscarinic but not adrenergic receptors, decreased Ca2+-ATPases activity and ER Ca2+ content.

  6. Boron-purity-dependent Raman spectra of CaB6

    International Nuclear Information System (INIS)

    Song, M.; Yang, I. S.; Kim, J. Y.; Cho, B. K.

    2006-01-01

    We report significant differences in the Raman spectra of two different kinds of CaB 6 single crystals grown from boron with a purity of 99.9 % (3N) or 99.9999 % (6N). Our Raman spectra of CaB 6 (3N) show peaks around 781 (T 2g ), 1141 (E g ), and 1283 cm -1 (A 1g ), and they are very similar to previous Raman spectra of CaB 6 . The E g mode shows a characteristic double-peak feature due to an additional weak broad peak centered around 1158 cm -1 . However, the Raman spectra of CaB 6 (6N) show sharp peaks around 771 (T 2g ), 1137 (E g ), and 1266 cm -1 (A 1g ). The peak frequencies are down shifted as much as ∼17 cm -1 . In addition, no additional peak feature is observed for the E g mode so that the mode is symmetric in the case of CaB 6 (6N). The X-ray powder diffraction patterns for both CaB 6 (3N) and CaB 6 (6N) show that the lattice parameters are essentially the same. The majority of the impurity in the 99.9 %-pure (3N) boron is C. Thus, we doped CaB 6 (6N) with C, making Ca(B 0.995 C 0.005 ) 6 , and looked for differences in the Raman spectra. The Raman spectra of Ca(B 0.995 C 0.005 ) 6 are nearly identical to those of CaB 6 (6N), indicating that the differences between the Raman spectra of CaB 6 (3N) and CaB 6 (6N) are not due to a C impurity. The Raman results show that the presence of impurities, not the amount of them, is enough to trigger local symmetry breaking in CaB 6 . The broadening of T 2g , the additional E g2 mode and the asymmetry of A 1g in CaB 6 (3N) can be understood in terms of the symmetry of the arrangements of the boron octahedra lowered by local symmetry breaking.

  7. PLCζ Induced Ca2+ Oscillations in Mouse Eggs Involve a Positive Feedback Cycle of Ca2+ Induced InsP3 Formation From Cytoplasmic PIP2

    Science.gov (United States)

    Sanders, Jessica R.; Ashley, Bethany; Moon, Anna; Woolley, Thomas E.; Swann, Karl

    2018-01-01

    Egg activation at fertilization in mammalian eggs is caused by a series of transient increases in the cytosolic free Ca2+ concentration, referred to as Ca2+ oscillations. It is widely accepted that these Ca2+ oscillations are initiated by a sperm derived phospholipase C isoform, PLCζ that hydrolyses its substrate PIP2 to produce the Ca2+ releasing messenger InsP3. However, it is not clear whether PLCζ induced InsP3 formation is periodic or monotonic, and whether the PIP2 source for generating InsP3 from PLCζ is in the plasma membrane or the cytoplasm. In this study we have uncaged InsP3 at different points of the Ca2+ oscillation cycle to show that PLCζ causes Ca2+ oscillations by a mechanism which requires Ca2+ induced InsP3 formation. In contrast, incubation in Sr2+ media, which also induces Ca2+ oscillations in mouse eggs, sensitizes InsP3-induced Ca2+ release. We also show that the cytosolic level Ca2+ is a key factor in setting the frequency of Ca2+ oscillations since low concentrations of the Ca2+ pump inhibitor, thapsigargin, accelerates the frequency of PLCζ induced Ca2+ oscillations in eggs, even in Ca2+ free media. Given that Ca2+ induced InsP3 formation causes a rapid wave during each Ca2+ rise, we use a mathematical model to show that InsP3 generation, and hence PLCζ's substate PIP2, has to be finely distributed throughout the egg cytoplasm. Evidence for PIP2 distribution in vesicles throughout the egg cytoplasm is provided with a rhodamine-peptide probe, PBP10. The apparent level of PIP2 in such vesicles could be reduced by incubating eggs in the drug propranolol which also reversibly inhibited PLCζ induced, but not Sr2+ induced, Ca2+ oscillations. These data suggest that the cytosolic Ca2+ level, rather than Ca2+ store content, is a key variable in setting the pace of PLCζ induced Ca2+ oscillations in eggs, and they imply that InsP3 oscillates in synchrony with Ca2+ oscillations. Furthermore, they support the hypothesis that PLCζ and sperm

  8. Chronic Loss of CA2 Transmission Leads to Hippocampal Hyperexcitability.

    Science.gov (United States)

    Boehringer, Roman; Polygalov, Denis; Huang, Arthur J Y; Middleton, Steven J; Robert, Vincent; Wintzer, Marie E; Piskorowski, Rebecca A; Chevaleyre, Vivien; McHugh, Thomas J

    2017-05-03

    Hippocampal CA2 pyramidal cells project into both the neighboring CA1 and CA3 subfields, leaving them well positioned to influence network physiology and information processing for memory and space. While recent work has suggested unique roles for CA2, including encoding position during immobility and generating ripple oscillations, an interventional examination of the integrative functions of these connections has yet to be reported. Here we demonstrate that CA2 recruits feedforward inhibition in CA3 and that chronic genetically engineered shutdown of CA2-pyramidal-cell synaptic transmission consequently results in increased excitability of the recurrent CA3 network. In behaving mice, this led to spatially triggered episodes of network-wide hyperexcitability during exploration accompanied by the emergence of high-frequency discharges during rest. These findings reveal CA2 as a regulator of network processing in hippocampus and suggest that CA2-mediated inhibition in CA3 plays a key role in establishing the dynamic excitatory and inhibitory balance required for proper network function. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Value and significance of tumor markers as CEA, CA125, SCC-Ag, CA199 and CYFRA21-1 in the diagnosis of cervical cancer

    Directory of Open Access Journals (Sweden)

    Xiao-Juan Wang

    2017-09-01

    Full Text Available Objective: To investigate the value and significance of serum CEA, CA125, SCC-Ag, CA199 and CYFRA21-1 in the diagnosis of cervical cancer by comparing the detection of five serum markers. Methods: A total of 108 cases were divided into three groups, including 60 cervical cancerpatients and 20 cervical intraepithelial neoplasiain patients treated in our hospital from September 2015 to September 2016 and 28 healthy women. Radioimmunoassay was used to detect and compare the serum levels of CA125, CA199, CYFRA21-1 and ELISA method was used to detect and compare the serum levels of SCC-Ag, CEA. Results: (1 There was no statistically significant difference in the serum CEA, CA125, SCC-Ag, CA199, CYFRA21-1 levels between CIN group and control group. The serums CEA, CA125, SCC-Ag, CA199, CYFRA21-1 levels of cervical cancer patients were significantly higher than the other two groups. The differences were statistically significant. (2There were statistically significant differences in the serum CEA, CA125, SCC-Ag, CA199, CYFRA21-1 levels between different cervical pathological type groups.The serum CA125, CA199, CEA levels of cervical glandular cancer patients were significantly higher than the other two groups. The differences were statistically significant. The serum SCC-Ag, CYFRA21-1 levels of cervical squamous cancer patients were significantly higher than the other two groups. The differences were statistically significant. Conclusion: The serums CEA, CA125, SCC-Ag, CA199, CYFRA21-1 levels of cervical cancer patients were significantly higher than cervical intraepithelial neoplasiain patients and healthy women. The serum CA125, CA199, CEA levels of cervical glandular cancer patients were significantly higher and the serum SCC-Ag, CYFRA21-1 levels of cervical squamous cancer patients were significantly higher. The five tumor markers can be used in diagnosis of cervical cancer and they are also worthy in distinguishing cervical pathological types.

  10. Labeling the human skeleton with {sup 41}Ca to assess changes in bone calcium metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Denk, E.; Hurrell, R.F.; Walczyk, T. [Institute of Food Science and Nutrition, ETH Zurich, Laboratory of Human Nutrition, Zuerich (Switzerland); Hillegonds, D.; Vogel, J. [Lawrence Livermore National Laboratory, Center for Accelerator Mass Spectrometry, Livermore, CA (United States); Synal, A. [Paul Scherrer Institute/ETH Zurich, Laboratory of Particle Physics, Zuerich (Switzerland); Geppert, C.; Wendt, K. [Johannes Gutenberg University, Institute of Physics, Mainz (Germany); Fattinger, K. [University Hospital Bern, Department of General Internal Medicine, Inselspital, Bern (Switzerland); Hennessy, C.; Berglund, M. [Institute for Reference Materials and Measurements (IRMM), European Commission Joint Research Centre, Geel (Belgium)

    2006-11-15

    Bone research is limited by the methods available for detecting changes in bone metabolism. While dual X-ray absorptiometry is rather insensitive, biochemical markers are subject to significant intra-individual variation. In the study presented here, we evaluated the isotopic labeling of bone using {sup 41}Ca, a long-lived radiotracer, as an alternative approach. After successful labeling of the skeleton, changes in the systematics of urinary {sup 41}Ca excretion are expected to directly reflect changes in bone Ca metabolism. A minute amount of {sup 41}Ca (100 nCi) was administered orally to 22 postmenopausal women. Kinetics of tracer excretion were assessed by monitoring changes in urinary {sup 41}Ca/{sup 40}Ca isotope ratios up to 700 days post-dosing using accelerator mass spectrometry and resonance ionization mass spectrometry. Isotopic labeling of the skeleton was evaluated by two different approaches: (i) urinary {sup 41}Ca data were fitted to an established function consisting of an exponential term and a power law term for each individual; (ii) {sup 41}Ca data were analyzed by population pharmacokinetic (NONMEM) analysis to identify a compartmental model that describes urinary {sup 41}Ca tracer kinetics. A linear three-compartment model with a central compartment and two sequential peripheral compartments was found to best fit the {sup 41}Ca data. Fits based on the use of the combined exponential/power law function describing urinary tracer excretion showed substantially higher deviations between predicted and measured values than fits based on the compartmental modeling approach. By establishing the urinary {sup 41}Ca excretion pattern using data points up to day 500 and extrapolating these curves up to day 700, it was found that the calculated {sup 41}Ca/{sup 40}Ca isotope ratios in urine were significantly lower than the observed {sup 41}Ca/{sup 40}Ca isotope ratios for both techniques. Compartmental analysis can overcome this limitation. By identifying

  11. Production of CaWO{sub 4} crystals for direct dark matter search with CRESST

    Energy Technology Data Exchange (ETDEWEB)

    Muenster, Andrea [Physik-Department and Excellence Cluster Universe, Technische Universitaet Muenchen, D-85748 Garching (Germany); Collaboration: CRESST-Collaboration

    2016-07-01

    The direct dark matter search experiment CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) uses scintillating CaWO{sub 4} single crystals as targets for possible recoils of dark matter particles. Since several years these CaWO{sub 4} crystals are produced directly at the Technische Universitaet Muenchen (TUM) including the CaWO{sub 4} powder production from the raw materials CaCO{sub 3} and WO{sub 3}, the CaWO{sub 4} crystal growth via the Czochralski method as well as the after-growth treatment of the crystals. In the recently finished CRESST-II Phase 2 (2013-2015), 4 TUM-grown crystals were installed in the main cryostat for the first time. Showing one of the best radiopurities of all installed crystals combined with an excellent detector performance the analysis of the crystal TUM40 resulted in the best sensitivity for low-mass dark matter particles in 2014. For the upcoming CRESST-III phase 2 we aim for a further improvement in radiopurity by a factor of 100. First results of a chemical purification of the raw materials as well as future plans to reduce the intrinsic background via recrystallization are presented.

  12. The functional genome of CA1 and CA3 neurons under native conditions and in response to ischemia

    Directory of Open Access Journals (Sweden)

    Rossner Moritz

    2007-10-01

    Full Text Available Abstract Background The different physiological repertoire of CA3 and CA1 neurons in the hippocampus, as well as their differing behaviour after noxious stimuli are ultimately based upon differences in the expressed genome. We have compared CA3 and CA1 gene expression in the uninjured brain, and after cerebral ischemia using laser microdissection (LMD, RNA amplification, and array hybridization. Results Profiling in CA1 vs. CA3 under normoxic conditions detected more than 1000 differentially expressed genes that belong to different, physiologically relevant gene ontology groups in both cell types. The comparison of each region under normoxic and ischemic conditions revealed more than 5000 ischemia-regulated genes for each individual cell type. Surprisingly, there was a high co-regulation in both regions. In the ischemic state, only about 100 genes were found to be differentially expressed in CA3 and CA1. The majority of these genes were also different in the native state. A minority of interesting genes (e.g. inhibinbetaA displayed divergent expression preference under native and ischemic conditions with partially opposing directions of regulation in both cell types. Conclusion The differences found in two morphologically very similar cell types situated next to each other in the CNS are large providing a rational basis for physiological differences. Unexpectedly, the genomic response to ischemia is highly similar in these two neuron types, leading to a substantial attenuation of functional genomic differences in these two cell types. Also, the majority of changes that exist in the ischemic state are not generated de novo by the ischemic stimulus, but are preexistant from the genomic repertoire in the native situation. This unexpected influence of a strong noxious stimulus on cell-specific gene expression differences can be explained by the activation of a cell-type independent conserved gene-expression program. Our data generate both novel

  13. Electrolytic recovery of calcium from molten CaO-CaCl2 salt-mix

    International Nuclear Information System (INIS)

    Mishra, B.; Olson, D.L.

    1993-01-01

    Calciothermic reduction of plutonium oxide is an industrial process for producing plutonium metal. The process is carried out in a molten calcium chloride medium which has a significantly high solubility for calcium oxide. However, the CaO-CaCl 2 salt-mix is radioactively contaminated and can not be discarded as such. Fused salt electrolysis of a simulated mix has been carried out using graphite anode and steel cathode to produce calcium. The dissolved calcium in CaCl 2 salt can be used insitu to reduce plutonium oxide. The primary difficulty in obtaining a cathodic calcium deposit was the use of graphite anose which indirectly controls all the back-reactions in the cell through which the deposited calcium is lost. A porous ceramic sheath has been used to essentially keep the anodic and cathodic products separate. The porosity of the sheath has been optimized by measuring its diffusion coefficient as a function of temperature. The influence of a porous sheath on the cell potential has been also analyzed

  14. 45Ca2+movements induced by Ca2+chloride in isolated rat aorta under K+-free conditions

    NARCIS (Netherlands)

    Wermelskirchen, D.; Nebel, U.; Wirth, A.; Wilffert, B.

    1991-01-01

    Increasing the extracellular Ca2+concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtained further insight into the mechanisms of this contraction45Ca2+uptake measurements were carried out with isolated rat aorta. Increasing the

  15. CA-45(2+) MOVEMENTS INDUCED BY CA2+ CHLORIDE IN ISOLATED RAT AORTA UNDER K+-FREE CONDITIONS

    NARCIS (Netherlands)

    WERMELSKIRCHEN, D; NEBEL, U; WIRTH, A; WILFFERT, B

    1991-01-01

    Increasing the extracellular Ca2+ concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtain further insight into the mechanism of this contraction Ca-45(2+) uptake measurements were carried out with isolated rat aorta. Increasing

  16. Decay properties of exotic N ≅ 28 S and Cl nuclei and the 48Ca/46Ca abundance ratio

    International Nuclear Information System (INIS)

    Sorlin, O.; Guillemaud-Mueller, D.; Mueller, A.C.; Borrel, V.; Dogny, S.; Pougheon, F.; Anne, R.; Lewitowicz, M.; Saint-Laurent, M.G.; Borcea, C.; Fifield, L.K.; Bazin, D.; Thielemann, F.K.; Hillebrandt, W.

    1992-01-01

    Beta-decay half-lives and β-delayed neutron-emission probabilities of the very neutron-rich nuclei 44 S and 45-47 Cl have been measured. These isotopes, which lie at or close to the N=28 magic shell were produced in interactions of a 60 MeV/u 48 Ca beam from GANIL (Grand Accelerateur National d'Ions Lourds) with a 64 Ni target and were separated by the doubly achromatic spectrometer LISE (Ligne d'Ions Super Epluches). Their decay was studied by a β-n time correlation measurement. The results are compared to recent model predictions and indicate a rapid weakening of the N=28 shell effect below 48 20 Ca 28 . The nuclear structure effects reflected in the decay properties of the exotic S and Cl isotopes may be the clue for the astrophysical understanding of the unusual 48 Ca/ 46 Ca abundance ratio measured in the solar system as well as the Ca-Ti-Cr anomalies observed in EK-inclusions of the Allende meteorite

  17. The Cytoplasmic Carbonic Anhydrases βCA2 and βCA4 Are Required for Optimal Plant Growth at Low CO2.

    Science.gov (United States)

    DiMario, Robert J; Quebedeaux, Jennifer C; Longstreth, David J; Dassanayake, Maheshi; Hartman, Monica M; Moroney, James V

    2016-05-01

    Carbonic anhydrases (CAs) are zinc metalloenzymes that interconvert CO2 and HCO3 (-) In plants, both α- and β-type CAs are present. We hypothesize that cytoplasmic βCAs are required to modulate inorganic carbon forms needed in leaf cells for carbon-requiring reactions such as photosynthesis and amino acid biosynthesis. In this report, we present evidence that βCA2 and βCA4 are the two most abundant cytoplasmic CAs in Arabidopsis (Arabidopsis thaliana) leaves. Previously, βCA4 was reported to be localized to the plasma membrane, but here, we show that two forms of βCA4 are expressed in a tissue-specific manner and that the two proteins encoded by βCA4 localize to two different regions of the cell. Comparing transfer DNA knockout lines with wild-type plants, there was no reduction in the growth rates of the single mutants, βca2 and βca4 However, the growth rate of the double mutant, βcaca4, was reduced significantly when grown at 200 μL L(-1) CO2 The reduction in growth of the double mutant was not linked to a reduction in photosynthetic rate. The amino acid content of leaves from the double mutant showed marked reduction in aspartate when compared with the wild type and the single mutants. This suggests the cytoplasmic CAs play an important but not previously appreciated role in amino acid biosynthesis. © 2016 American Society of Plant Biologists. All Rights Reserved.

  18. Predictors of pretreatment CA125 at ovarian cancer diagnosis

    DEFF Research Database (Denmark)

    Babic, Ana; Cramer, Daniel W; Kelemen, Linda E

    2017-01-01

    PURPOSE: Cancer antigen 125 (CA125) is a glycoprotein expressed by epithelial cells of several normal tissue types and overexpressed by several epithelial cancers. Serum CA125 levels are mostly used as an aid in the diagnosis of ovarian cancer patients, to monitor response to treatment and detect...... in CA125 between studies and linear regression to estimate the association between epidemiologic factors and tumor characteristics and pretreatment CA125 levels. RESULTS: In age-adjusted models, older age, history of pregnancy, history of tubal ligation, family history of breast cancer, and family...... cancer recurrence. Besides tumor characteristics, CA125 levels are also influenced by several epidemiologic factors, such as age, parity, and oral contraceptive use. Identifying factors that influence CA125 levels in ovarian cancer patients could aid in the interpretation of CA125 values for individuals...

  19. (Solid + liquid) phase equilibria of (Ca(H2PO2)2 + CaCl2 + H2O) and (Ca(H2PO2)2 + NaH2PO2 + H2O) ternary systems at T = 323.15 K

    International Nuclear Information System (INIS)

    Cao, Hong-yu; Zhou, Huan; Bai, Xiao-qin; Ma, Ruo-xin; Tan, Li-na; Wang, Jun-min

    2016-01-01

    Graphical abstract: Solubility diagram of the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system at T = (323.15 and 298.15) K. - Highlights: • Phase diagrams of Ca 2+ -H 2 PO 2 − -Cl − -H 2 O, Ca 2+ -Na + -H 2 PO 2 − -H 2 O at 323.15 K were obtained. • Incompatible double salt of NaCa(H 2 PO 2 ) 3 in Ca 2+ -Na + -H 2 PO 2 − -H 2 O system was determined. • Density diagram of the corresponding liquid were simultaneously measured. - Abstract: Calcium hypophosphite has been widely used as an anti-corrosive agent, flame retardant, fertilizer, assistant for Ni electroless plating, and animal nutritional supplement. High purity calcium hypophosphite can be synthesized via the replacement reaction of sodium hypophosphite and calcium chloride. In this work, the (solid + liquid) phase equilibria of (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) and (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) ternary systems at T = 323.15 K were studied experimentally via the classical isothermal solubility equilibrium method, and the phase diagrams for these two systems were obtained. It was found that two solid salts of CaCl 2 ·2H 2 O and Ca(H 2 PO 2 ) 2 exist in the (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) system, and three salts of Ca(H 2 PO 2 ) 2 , NaH 2 PO 2 ·H 2 O and one incompatible double salt, NaCa(H 2 PO 2 ) 3 occur in the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system.

  20. High-pressure X-ray diffraction and Raman spectroscopy of CaFe2O4-type β-CaCr2O4

    Science.gov (United States)

    Zhai, Shuangmeng; Yin, Yuan; Shieh, Sean R.; Shan, Shuangming; Xue, Weihong; Wang, Ching-Pao; Yang, Ke; Higo, Yuji

    2016-04-01

    In situ high-pressure synchrotron X-ray diffraction and Raman spectroscopic studies of orthorhombic CaFe2O4-type β-CaCr2O4 chromite were carried out up to 16.2 and 32.0 GPa at room temperature using multi-anvil apparatus and diamond anvil cell, respectively. No phase transition was observed in this study. Fitting a third-order Birch-Murnaghan equation of state to the P-V data yields a zero-pressure volume of V 0 = 286.8(1) Å3, an isothermal bulk modulus of K 0 = 183(5) GPa and the first pressure derivative of isothermal bulk modulus K 0' = 4.1(8). Analyses of axial compressibilities show anisotropic elasticity for β-CaCr2O4 since the a-axis is more compressible than the b- and c-axis. Based on the obtained and previous results, the compressibility of several CaFe2O4-type phases was compared. The high-pressure Raman spectra of β-CaCr2O4 were analyzed to determine the pressure dependences and mode Grüneisen parameters of Raman-active bands. The thermal Grüneisen parameter of β-CaCr2O4 is determined to be 0.93(2), which is smaller than those of CaFe2O4-type CaAl2O4 and MgAl2O4.

  1. Phosphorylation of CaMKII in the rat dorsal raphe nucleus plays an important role in sleep-wake regulation.

    Science.gov (United States)

    Cui, Su-Ying; Li, Sheng-Jie; Cui, Xiang-Yu; Zhang, Xue-Qiong; Yu, Bin; Sheng, Zhao-Fu; Huang, Yuan-Li; Cao, Qing; Xu, Ya-Ping; Lin, Zhi-Ge; Yang, Guang; Song, Jin-Zhi; Ding, Hui; Wang, Zi-Jun; Zhang, Yong-He

    2016-02-01

    The Ca(2+) modulation in the dorsal raphe nucleus (DRN) plays an important role in sleep-wake regulation. Calmodulin-dependent kinase II (CaMKII) is an important signal-transducing molecule that is activated by Ca(2+) . This study investigated the effects of intracellular Ca(2+) /CaMKII signaling in the DRN on sleep-wake states in rats. Maximum and minimum CaMKII phosphorylation was detected at Zeitgeber time 21 (ZT 21; wakefulness state) and ZT 3 (sleep state), respectively, across the light-dark rhythm in the DRN in rats. Six-hour sleep deprivation significantly reduced CaMKII phosphorylation in the DRN. Microinjection of the CAMKII activation inhibitor KN-93 (5 or 10 nmol) into the DRN suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REM sleep (NREMS). Application of a high dose of KN-93 (10 nmol) increased slow-wave sleep (SWS) time, SWS bouts, the mean duration of SWS, the percentage of SWS relative to total sleep, and delta power density during NREMS. Microinjection of CaCl2 (50 nmol) in the DRN increased CaMKII phosphorylation and decreased NREMS, SWS, and REMS. KN-93 abolished the inhibitory effects of CaCl2 on NREMS, SWS, and REMS. These data indicate a novel wake-promoting and sleep-suppressing role for the Ca(2+) /CaMKII signaling pathway in DRN neurons. We propose that the intracellular Ca(2+) /CaMKII signaling in the dorsal raphe nucleus (DRN) plays wake-promoting and sleep-suppressing role in rats. Intra-DRN application of KN-93 (CaMKII activation inhibitor) suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REMS (NREMS). Intra-DRN application of CaCl2 attenuated REMS and NREMS. We think these findings should provide a novel cellular and molecular mechanism of sleep-wake regulation. © 2015 International Society for Neurochemistry.

  2. CA72-4 combined with CEA, CA125 and CAl9-9 improves the sensitivity for the early diagnosis of gastric cancer.

    Science.gov (United States)

    Yang, Ai-Ping; Liu, Jun; Lei, He-Yue; Zhang, Qun-Wei; Zhao, Long; Yang, Guo-Hui

    2014-11-01

    To determine whether the combination of tumor markers (CA72-4, CA125, CA19-9 and CEA) could increase the sensitivity and accuracy for in the diagnosis of gastric cancer (GC). This study is a retrospective analysis. A total of 426 patients, including 106 patients with GC, 149 patients with benign gastric diseases and 171 healthy people, who visited Zhejiang Xiaoshan Hospital from January 2011 to December 2013, were measured by serum markers, including CA72-4, CA125, CA19-9 and CEA. Statistical analyses including area under curve (AUC) of receiver operating characteristic (ROC) curve, and logistic regression analysis, were performed to evaluate the diagnostic value of these markers on GC. Serum levels of CA72-4, CEA, CA125 and CA19-9 were higher in the GC group than those in the benign gastric disease group and the healthy control group (PCEA, CA125 and CA19-9 at the recommended cut-off level for all patients were 33.0%, 25.5%, 31.1% and 38.7%, respectively. However, when all four markers were used in combination the sensitivity increased to 66.0%. But by using an optimal cut-off value, the sensitivities of all four markers for the diagnosis of GC were improved. Especially the sensitivity of CEA increased to 73.6% and the sensitivity of the combination of the tumor markers increased to 75.5%. The age and gender had no effects on the diagnostic value of these markers. With the help of optimal cut-off values based on ROC curve and logistic regression analysis, the combination of these markers could improve the sensitivity for the diagnosis of GC based on common serum tumor markers. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack.

    Science.gov (United States)

    Wong, Adrian; Black, Sandra E; Yiu, Stanley Y P; Au, Lisa W C; Lau, Alexander Y L; Soo, Yannie O Y; Chan, Anne Y Y; Leung, Thomas W H; Wong, Lawrence K S; Kwok, Timothy C Y; Cheung, Theodore C K; Leung, Kam-Tat; Lam, Bonnie Y K; Kwan, Joseph S K; Mok, Vincent C T

    2018-05-01

    The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy. Copyright © 2018 John Wiley & Sons, Ltd.

  4. ORF Alignment: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.6649; Contig19-10251; complement(36800..38461); BR...87398.1| ... TFIIB related subunit of TFIIIB (BRF1) [Candida ... albicans] pir||B55483 transcr...L Transcription factor IIIB 70 kDa ... subunit (TFIIIB) (B-related factor)

  5. ORF Alignment: Ca19AnnotatedDec2004aaSeq [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available Ca19AnnotatedDec2004aaSeq orf19.2029; Contig19-10139; 79190..80278; RFC5*; DNA replicationn factor C | lead...ing strand elongation mismatch repair ... (ATPase); >1a5t0 2 329 7 339 1e-22 ... gb|EAL00

  6. Can preoperative CEA and CA19-9 serum concentrations suggest metastatic disease in colorectal cancer patients?

    Science.gov (United States)

    Stojkovic Lalosevic, Milica; Stankovic, Sanja; Stojkovic, Mirjana; Markovic, Velimir; Dimitrijevic, Ivan; Lalosevic, Jovan; Petrovic, Jelena; Brankovic, Marija; Pavlovic Markovic, Aleksandra; Krivokapic, Zoran

    2017-01-01

    This study was designed to investigate the efficiency of preoperative serum carcinoembryonic antigen (CEA) and carbohydrate cancer antigen (CA19-9) levels for diagnosing synchronous liver metastases and lymph node in colorectal carcinoma (CRC) patients. A total of 300 patients with histologically diagnosed CRC were included in this study between May 2014 and March 2015. The data were obtained prospectively from patient's medical records: medical history, demographics, tumor location, differentiation (grade), depth of the tumor (T), lymph node metastases (N), distant metastases (M), lymphatics, venous and perineural invasion, and disease stage. Tumor markers were measured with an electrochemiluminescent assay and the reference value was 5ng/ml for CEA and for Ca19-9, 37u/ml. There was A high statistically significant difference in the levels of serum CEA and CA19-9 between different disease stages of CRC (PCEA (stage I 3.76±8.73; II 5.68±17.27, III 7.56±14.81, and IV 70.90±253.23) and CA 19-9 levels (stage I 9.65±11.03, II 9.83±11.09; III 19.58±36.91, and IV 228.9±985.38, respectively). The mean CEA and CA19-9 serum levels were significantly higher in patients with regional lymph nodes involvement (CEA 37.21±177.85 vs 4.79±9.90, CA19-9 119.51±687.71 VS 12.24±17.69, respectively, PCEA 86.56±277.65 vs. 5.98±12.98, and CA19-9 273.27±1073.46 vs. 4.98±3142, respectively, with PCEA and CA 19-9, 3.5 ng/mL and 7.5 U/mL, respectively. While, a cut-off value for the presence of synchronous liver metastases of these two markers was 3.5ng/mL AND 5.5 U/mL. Our study showed that tumor makers, CEA and CA19-9, can be used as diagnostic factors regarding the severity of CRC specifically to suggest metastatic disease in CRC.

  7. Hypothalamic CaMKKβ mediates glucagon anorectic effect and its diet-induced resistance

    Science.gov (United States)

    Quiñones, Mar; Al-Massadi, Omar; Gallego, Rosalía; Fernø, Johan; Diéguez, Carlos; López, Miguel; Nogueiras, Ruben

    2015-01-01

    Objective Glucagon receptor antagonists and humanized glucagon antibodies are currently studied as promising therapies for obesity and type II diabetes. Among its variety of actions, glucagon reduces food intake, but the molecular mechanisms mediating this effect as well as glucagon resistance are totally unknown. Methods Glucagon and adenoviral vectors were administered in specific hypothalamic nuclei of lean and diet-induced obese rats. The expression of neuropeptides controlling food intake was performed by in situ hybridization. The regulation of factors of the glucagon signaling pathway was assessed by western blot. Results The central injection of glucagon decreased feeding through a hypothalamic pathway involving protein kinase A (PKA)/Ca2+-calmodulin-dependent protein kinase kinase β (CaMKKβ)/AMP-activated protein kinase (AMPK)-dependent mechanism. More specifically, the central injection of glucagon increases PKA activity and reduces protein levels of CaMKKβ and its downstream target phosphorylated AMPK in the hypothalamic arcuate nucleus (ARC). Consistently, central glucagon significantly decreased AgRP expression. Inhibition of PKA and genetic activation of AMPK in the ARC blocked glucagon-induced anorexia in lean rats. Genetic down-regulation of glucagon receptors in the ARC stimulates fasting-induced hyperphagia. Although glucagon was unable to decrease food intake in DIO rats, glucagon sensitivity was restored after inactivation of CaMKKβ, specifically in the ARC. Thus, glucagon decreases food intake acutely via PKA/CaMKKβ/AMPK dependent pathways in the ARC, and CaMKKβ mediates its obesity-induced hypothalamic resistance. Conclusions This work reveals the molecular underpinnings by which glucagon controls feeding that may lead to a better understanding of disease states linked to anorexia and cachexia. PMID:26909312

  8. Intrinsic polarization changes and the H-alpha and CA II emission features in T-Tauri stars

    Science.gov (United States)

    Svatos, J.; Solc, M.

    1981-12-01

    On the basis of the correlation between polarization and emission features observed in certain T-Tauri stars, it is concluded that flaring effects associated with UV and/or X-ray irradiation and with increased magnetic field are responsible for the intrinsic polarization changes in T-Tauri stars. The correlation between emission Ca II lines and polarization degree both in Miras and T-Tau stars is thought to support the contention that the intrinsic polarization changes are due to the irradiation of silicate-like grains. In some T-Tau stars the increase in the magnetic field can be the principal agent causing the polarization increase due to the enhanced orientation of elongated grains.

  9. Inhibition of PaCaMKII-E isoform in the dorsal unpaired median neurosecretory cells of cockroach reduces nicotine- and clothianidin-induced currents.

    Science.gov (United States)

    List, Olivier; Calas-List, Delphine; Taillebois, Emiliane; Juchaux, Marjorie; Heuland, Emilie; Thany, Steeve H

    2014-08-01

    Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII), which transduces the signal into downstream effects. We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms, and only PaCaMKII-E isoform is specifically expressed in the dorsal unpaired median neurosecretory cells. In the present study, using antisense oligonucleotides, we demonstrated that PaCaMKII-E isoform inhibition reduced nicotine-induced currents through α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptor subtypes. Specifically, PaCaMKII-E isoform is sufficient to repress nicotinic current amplitudes as a result of its depression by antisense oligonucleotides. Similar results were found using the neonicotinoid insecticide clothianidin, which acted as a full agonist of dorsal unpaired median neuron nicotinic acetylcholine receptors. Clothianidin current amplitudes are strongly reduced under bath application of PaCaMKII-E antisense oligonucleotides but no significant results are found with α-bungarotoxin co-applied, demonstrating that CaMKII-E isoform affects nicotine currents through α-bungarotoxin-sensitive and -insensitive receptor subtypes whereas clothianidin currents are reduced via α-bungarotoxin-insensitive receptors. In addition, we found that intracellular calcium increase induced by nicotine and clothianidin were reduced by PaCaMKII-E antisense oligonucleotides, demonstrating that intracellular calcium increase induced by nicotine and clothianidin are affected by PaCaMKII-E inhibition. Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII). We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms and only PaCaMKII-E isoform was specifically expressed in the dorsal unpaired median neurosecretory cells. Here we show that specific inhibition of PaCaMKII-E isoform is

  10. Autonomous CaMKII Activity as a Drug Target for Histological and Functional Neuroprotection after Resuscitation from Cardiac Arrest

    Directory of Open Access Journals (Sweden)

    Guiying Deng

    2017-01-01

    Full Text Available The Ca2+/calmodulin-dependent protein kinase II (CaMKII is a major mediator of physiological glutamate signaling, but its role in pathological glutamate signaling (excitotoxicity remains less clear, with indications for both neuro-toxic and neuro-protective functions. Here, the role of CaMKII in ischemic injury is assessed utilizing our mouse model of cardiac arrest and cardiopulmonary resuscitation (CA/CPR. CaMKII inhibition (with tatCN21 or tatCN19o at clinically relevant time points (30 min after resuscitation greatly reduces neuronal injury. Importantly, CaMKII inhibition also works in combination with mild hypothermia, the current standard of care. The relevant drug target is specifically Ca2+-independent “autonomous” CaMKII activity generated by T286 autophosphorylation, as indicated by substantial reduction in injury in autonomy-incompetent T286A mutant mice. In addition to reducing cell death, tatCN19o also protects the surviving neurons from functional plasticity impairments and prevents behavioral learning deficits, even at extremely low doses (0.01 mg/kg, further highlighting the clinical potential of our findings.

  11. Chronic Ca2+ influx through voltage-dependent Ca2+ channels enhance delayed rectifier K+ currents via activating Src family tyrosine kinase in rat hippocampal neurons.

    Science.gov (United States)

    Yang, Yoon-Sil; Jeon, Sang-Chan; Kim, Dong-Kwan; Eun, Su-Yong; Jung, Sung-Cherl

    2017-03-01

    Excessive influx and the subsequent rapid cytosolic elevation of Ca 2+ in neurons is the major cause to induce hyperexcitability and irreversible cell damage although it is an essential ion for cellular signalings. Therefore, most neurons exhibit several cellular mechanisms to homeostatically regulate cytosolic Ca 2+ level in normal as well as pathological conditions. Delayed rectifier K + channels (I DR channels) play a role to suppress membrane excitability by inducing K + outflow in various conditions, indicating their potential role in preventing pathogenic conditions and cell damage under Ca 2+ -mediated excitotoxic conditions. In the present study, we electrophysiologically evaluated the response of I DR channels to hyperexcitable conditions induced by high Ca 2+ pretreatment (3.6 mM, for 24 hours) in cultured hippocampal neurons. In results, high Ca 2+ -treatment significantly increased the amplitude of I DR without changes of gating kinetics. Nimodipine but not APV blocked Ca 2+ -induced I DR enhancement, confirming that the change of I DR might be targeted by Ca 2+ influx through voltage-dependent Ca 2+ channels (VDCCs) rather than NMDA receptors (NMDARs). The VDCC-mediated I DR enhancement was not affected by either Ca 2+ -induced Ca 2+ release (CICR) or small conductance Ca 2+ -activated K + channels (SK channels). Furthermore, PP2 but not H89 completely abolished I DR enhancement under high Ca 2+ condition, indicating that the activation of Src family tyrosine kinases (SFKs) is required for Ca 2+ -mediated I DR enhancement. Thus, SFKs may be sensitive to excessive Ca 2+ influx through VDCCs and enhance I DR to activate a neuroprotective mechanism against Ca 2+ -mediated hyperexcitability in neurons.

  12. Line list for the ground state of CaF

    Science.gov (United States)

    Hou, Shilin; Bernath, Peter F.

    2018-05-01

    The molecular potential energy function and electronic dipole moment function for the ground state of CaF were studied with MRCI, ACPF, and RCCSD(T) ab initio calculations. The RCCSD(T) potential function reproduces the experimental vibrational intervals to within ∼2 cm-1. The RCCSD(T) dipole moment at the equilibrium internuclear separation agrees well with the experimental value. Over a wide range of internuclear separations, far beyond the range associated with the observed spectra, the ab initio dipole moment functions are similar and highly linear. An extended Morse oscillator (EMO) potential function was also obtained by fitting the observed lines of the laboratory vibration-rotation and pure rotation spectra of the 40CaF X2Σ+ ground state. The fitted potential reproduces the observed transitions (v ≤ 8, N ≤ 121, Δv = 0, 1) within their experimental uncertainties. With this EMO potential and the RCCSD(T) dipole moment function, line lists for 40CaF, 42CaF, 43CaF, 44CaF, 46CaF, and 48CaF were computed for v ≤ 10, N ≤ 121, Δv = 0-10. The calculated emission spectra are in good agreement with an observed laboratory spectrum of CaF at a sample temperature of 1873 K.

  13. Calcium in pollen-pistil interaction in 'Petunia hybrida Hat'. Pt. 3. Localization of Ca2+ ions and Ca2+-ATPase in pollinated pistil

    International Nuclear Information System (INIS)

    Bednarska, E.; Butowt, R.

    1995-01-01

    Studies were carried out of Ca 2+ and Ca 2+ -ATPase localization in pollinated (6 and 48 h after pollination) pistils of 'Petunia hybrida'. The results were confronted with Ca 2+ localization in mature pollen grain and in unpollinated pistil. It has been found that after pollination the number of Ca 2+ sequestered in the stigmal exudate and in the sporoderm of the pollen grain gets lower. That phenomenon was associated with the appearance of a large number of Sb/Ca precipitates in the submembrane cytoplasm of the germinating pollen. In the vacuolized pollen grain, i.e. grown into a pollen tube, there were only a few precipitates. In the pollen tube, Ca 2+ were found in the organelles of the tip cytoplasm and in the external pectin cell wall. Studies with the use of 45 Ca 2+ have revealed that the source of calcium ions incorporated into the pollen tube tip and its pectin wall is the transmitting tract of the style. In the transmitting tract overgrown with pollen tubes, Ca 2+ were localized in the intercellular matrix and in the transmitting cell. Sb/Ca precipitates occurred in the nuclei, around the secretary vesicles and on the plasmalemma in the transverse walls region. Elevated Ca 2+ level was found in degenerating cells (inhibited pollen tubes, transmitting cells, nucellar cells). The progressing degeneration process of the cells of the transmitting tract of the pollinated pistil was associated with a decrease in the activity of plasmalemma Ca 2+ -ATPase. (author). 30 refs, 19 figs

  14. Expression of activated PIK3CA in ovarian surface epithelium results in hyperplasia but not tumor formation.

    Directory of Open Access Journals (Sweden)

    Shun Liang

    Full Text Available The Phosphatidylinositol 3'-kinase is a key regulator in various cancer-associated signal transduction pathways. Genetic alterations of its catalytic subunit alpha, PIK3CA, have been identified in ovarian cancer. Our in vivo data suggests that PIK3CA activation is one of the early genetic events in ovarian cancer. However, its role in malignant transformation of ovarian surface epithelium (OSE is largely unclear.Using the Müllerian inhibiting substance type II receptor (MISIIR promoter, we generated transgenic mice that expressed activated PIK3CA in the Müllerian epithelium. Overexpression of PIK3CA in OSE induced remarkable hyperplasia, but was not able to malignantly transform OSE in vivo. The consistent result was also observed in primary cultured OSEs. Although enforced expression of PIK3CA could not induce OSE anchorage-independent growth, it significantly increased anchorage-independent growth of OSE transformed by mutant K-ras.While PIK3CA activation may not be able to initiate OSE transformation, we conclude that activation of PIK3CA may be an important molecular event contributing to the maintenance of OSE transformation initiated by oncogenes such as K-ras.

  15. Observation of forbidden (E2) lines in the ultraviolet spectra of Ca II, Sr II, and Ba II by inductively coupled plasma emission spectroscopy

    International Nuclear Information System (INIS)

    Doidge, Peter S.

    2013-01-01

    Forbidden (electric quadrupole, E2) transitions of the type ns 2 S 1/2 –nd 2 D 3/2 and ns 2 S 1/2 –nd 2 D 5/2 in the ultraviolet spectra of singly ionized Ca, Sr, and Ba (with n = 4, 5 or 6 for Ca, Sr, and Ba, respectively) have been observed in the emission spectrum of an inductively coupled argon plasma. Wavelengths and wavenumbers of the six lines are reported and the values are in good agreement with those expected from literature data for the energy levels involved. - Highlights: • Wavelengths measured using commercially available ICP emission spectrometer • First wavelength and wavenumber measurements of some E2 lines of Ba +, Ca +, Sr + • Evidence for small plasma shifts in the wavenumbers of Ba + and Sr +

  16. The Correlation between Serum and Peritoneal Fluid CA125 The Correlation between Serum and Peritoneal Fluid CA125

    Directory of Open Access Journals (Sweden)

    Saghar Salehpour

    2009-01-01

    Full Text Available Background: Despite a high prevalence of endometriosis, there still exist many challenges indiagnosing the disease. This study aims to evaluate non-invasive and practical diagnostic methodsby measuring serum and peritoneal fluid CA 125 levels in patients with endometriosis. A secondaryaim is to determine the correlation between these markers with the stage of disease as well as therelationship of the two markers with each other.Materials and Methods: This is a cross-sectional study of 60 women who underwent laparoscopyfor benign conditions. Based on laparoscopic findings and biopsy results, patients were divided to twogroups; one group included patients with pelvic endometriosis (35 patients and the second enrolledpatients free from endometriosis (25 patients. Serum and peritoneal fluid specimens were provided at thetime of laparoscopy and CA125 levels were then assessed by electrochemiluminescence immunoassay.Results: Mean serum and peritoneal fluid CA125 levels were significantly higher in women withendometriosis as compared to the control group (26.42 ± 24.34 IU/ml versus 12.64 ± 6.87 IU/mlin serum and 2203.54 + 993.19 IU/ml versus 1583.42 ± 912.51 IU/ml in peritoneal fluid, p<0.05.CA 125 levels also varied proportionally with the stage of endometriosis; but showed a significantdifference only in higher stages of the disease, both in serum and peritoneal fluid. We calculatedthe cut-off value suggesting a diagnosis of pelvic endometriosis as 14.70 IU/ml for serum and1286.5 IU/ml for peritoneal fluid CA125. A linear correlation between CA 125 levels in serum andperitoneal fluid in patients with pelvic endometriosis has also been observed.Conclusion: Serum and peritoneal fluid CA 125 levels are simple and non-surgical tools fordiagnosing and staging pelvic endometriosis. These markers are of greater diagnostic value inhigher stages of the disease.

  17. The value of clinical expression of CA series in malignancy diagnosis

    International Nuclear Information System (INIS)

    Wei Zhenyuan; Wang Jie

    2002-01-01

    Objective: To study the diagnosis of liver cancer, coloprocto-carcinoma, ovary cancer, pancreatic carcinoma, breast cancer, lung cancer and stomach cancer by labelling immunoassay of CA50, CA125, CA199 and CA153. Methods: The authors had measured the serum content of these tumor markers in 67 liver cancer, 88 coloprocto-carcinoma, 48 ovary cancer, 36 pancreatic carcinoma, 34 breast cancer, 128 lung cancer, 271 stomach cancer and 68 normal controls with labelling immunoassay (LIA). The mean coefficient of variation for intra and inter batch-assay of CA50, CA125, CA199 and CA153 were 3.7% and 8.1%, 4.8% and 10.1%, 7.6% and 12.3%, 8.1% and 10.4% respectively. The average recovery ratio was between 95% and 107%. Results: The levels of CA50 in stomach cancer and coloprocto-carcinoma were significantly higher than those in normal controls (p < 0.001). The levels of CA125 in ovary cancer and lung cancer were significantly higher than in normal controls (p < 0.001). The levels of CA199 in pancreatic carcinoma cancer was significantly higher than those in normal controls (p < 0.001). The levels of CA153 in breast cancer was significantly higher than those in normal controls (p < 0.001). The mean levels of CA50, CA125, CA199 and CA153 in 68 normal controls were 12.4 +- 3.9 U/ml, 14.3 +- 3.9 U/ml, 14.3 +- 10.5 U/ml, 10.0 +- 8.4 U/ml and 15.2 +- 7.5 U/ml respectively. Conclusion: In present study of 672 cases, CA50 measurement seems to be most useful for diagnosis of gastric and coloprocto-carcinoma, CA125 for ovarian cancer, CA199 for pancreatic cancer and CA153 for breast cancer (p < 0.001)

  18. Ion microprobe imaging of 44Ca-labeled mammalian chromosomes

    International Nuclear Information System (INIS)

    Levi-Setti, R.; Gavrilov, K.L.; Strissel, P.L.; Strick, R.

    2004-01-01

    In our previous investigation, we showed for the first time high-resolution analytical images of the cation composition of mammalian interphase and mitotic cells as well as of isolated metaphase chromosomes using the University of Chicago scanning ion microprobe (UC-SIM). In order to preserve the ionic integrity of the analyzed cells and prevent the well known occurrence of analytical artifacts due to the high diffusivity of cations in biological samples we used fast cryo-preservation methods (freeze-drying and freeze fracture), without any pre-fixations or washes. We identified the role of the cations in chromosome structure and maintenance using SIMS imaging and immunfluorescence methodologies. Importantly, we determined that the above cations are essential participants in chromosome condensation and maintenance of chromatin higher order structure, through their presumed function in DNA electrostatic neutralization and the direct interaction of Ca 2+ , in particular, with structural proteins. In addition, both Ca 2+ and Mg 2+ showed the same cell cycle regulation where during interphase both cations were enriched in the cytosol, particularly in organelles then at mitosis became specifically bound to chromatin. Our present research interest focuses on a more detailed analysis of the distribution of Ca 2+ throughout the different cell cycle stages, e.g. G1, G2 and mitosis. We have chosen the stable isotope 44 Ca as a tracer to follow Ca 2+ throughout the cell cycle. This nuclide occurs naturally in the ratio 44 Ca/ 40 Ca+ 44 Ca of 2.06%, so that incorporation at higher concentrations into chromatin or other cellular components should be easily detected by SIMS. Such incorporation can be obtained either by growing cells in a medium where ordinary Ca is replaced entirely by 44 Ca, or by replacing the cell culture medium with the 44 Ca medium for a gated time span (pulsing), after appropriate cell cycle stage synchronization. In this paper, we describe our

  19. Exploring B/Ca as a pH proxy in bivalves: relationships between Mytilus californianus B/Ca and environmental data from the northeast Pacific

    Directory of Open Access Journals (Sweden)

    N. Shimizu

    2011-09-01

    Full Text Available A distinct gap in our ability to understand changes in coastal biology that may be associated with recent ocean acidification is the paucity of directly measured ocean environmental parameters at coastal sites in recent decades. Thus, many researchers have turned to sclerochronological reconstructions of water chemistry to document the historical seawater environment. In this study, we explore the relationships between B/Ca and pH to test the feasibility of B/Ca measured on the ion probe as a pH proxy in the California mussel, Mytilus californianus. Heterogeneity in a range of ion microprobe standards is assessed, leading to reproducible B/Ca ratios at the 5% level. The B/Ca data exhibit large excursions during winter months, which are particularly pronounced during the severe winters of 2004–2005 and 2005–2006. Furthermore, B/Ca ratios are offset in different parts of the skeleton that calcified at the same time. We compare the M. californianus B/Ca record to directly measured environmental data during mussel growth from the period of 1999–2009 to examine whether seawater chemistry or temperature plays a role in controlling shell B/Ca. A suite of growth rate models based on measured temperature are compared to the B/Ca data to optimise the potential fit of B/Ca to pH. Despite sampling conditions that were well-suited to testing a pH control on B/Ca, including a close proximity to an environmental record, a distinct change in pH at the sampling locale, and a growth model designed to optimise the correlations between seawater pH and shell B/Ca, we do not see a strong correlations between pH and shell B/Ca (maximum coefficient of determination, r2, of 0.207. Instead, our data indicate a strong biological control on B/Ca as observed in some other carbonate-forming organisms.

  20. Complicaciones tardías en diabetes mellitus tipo 2 en el Hospital II Essalud - Cañete

    Directory of Open Access Journals (Sweden)

    Charlton Fernando Untiveros Mayorga

    2004-04-01

    Full Text Available Objetivo: Determinar las características clínicas y las complicaciones tardías en los pacientes con diabetes tipo 2 atendidos en los consultorios de medicina general y del Programa de Diabetes del Hospital II EsSALUD-Cañete. Material y Métodos: Se realizó un estudio descriptivo de serie de casos en el que se evaluaron 94 pacientes con diabetes tipo 2 elegidos aleatoriamente durante su control ambulatorio, realizándose una entrevista y evaluación clínica durante los meses de junio y julio del 2001. Resultados: La población de pacientes estudiada tuvo una edad promedio de 64.56 + 11.61. Cincuenta y tres pacientes eran mujeres (56.4%. El 68.1% de los pacientes recibían hipoglicemiantes orales y el 11.7% requerían del uso de insulina. Los transtornos lipídicos predominantes fueron la elevación del LDL-Colesterol y disminución del HDL-Colesterol. La retinopatía diabética (88.9% e hipertensión arterial (61.3% fueron las complicaciones más frecuentes. Vasculopatía periférica, neuropatía periférica y neuropatía autonómica fueron otras complicaciones crónicas frecuentes halladas en la población de estudio. Conclusiones: Las complicaciones cardiovasculares (micro y macrovasculares en la población de pacientes con diabetes tipo 2 atendidos ambulatoriamente en el Hospital II EsSALUD-Cañete fueron las más frecuentes. (Rev Med Hered 2004; 15:64-69.

  1. TRPV5, the gateway to Ca2+ homeostasis.

    NARCIS (Netherlands)

    Mensenkamp, A.R.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Ca2+ homeostasis in the body is tightly controlled, and is a balance between absorption in the intestine, excretion via the urine, and exchange from bone. Recently, the epithelial Ca2+ channel (TRPV5) has been identified as the gene responsible for the Ca2+ influx in epithelial cells of the renal

  2. Sodium-calcium exchanger and R-type Ca2+ channels mediate spontaneous [Ca2+](i) oscillations in magnocellular neurones of the rat supraoptic nucleus

    Czech Academy of Sciences Publication Activity Database

    Kortus, Štěpán; Srinivasan, Ch.; Forostyak, O.; Zápotocký, Martin; Ueta, Y.; Syková, E.; Chvátal, A.; Verkhratsky, A.; Dayanithi, G.

    2016-01-01

    Roč. 59, č. 6 (2016), s. 289-298 ISSN 0143-4160 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : magnocellular neurosecretory cells * voltage-gated Ca2+ channels * intracellular Ca2+ stores * Ca2+ imaging * Ca2+ oscillations Subject RIV: FH - Neurology Impact factor: 3.707, year: 2016

  3. Stapled Voltage-Gated Calcium Channel (CaV) α-Interaction Domain (AID) Peptides Act As Selective Protein-Protein Interaction Inhibitors of CaV Function.

    Science.gov (United States)

    Findeisen, Felix; Campiglio, Marta; Jo, Hyunil; Abderemane-Ali, Fayal; Rumpf, Christine H; Pope, Lianne; Rossen, Nathan D; Flucher, Bernhard E; DeGrado, William F; Minor, Daniel L

    2017-06-21

    For many voltage-gated ion channels (VGICs), creation of a properly functioning ion channel requires the formation of specific protein-protein interactions between the transmembrane pore-forming subunits and cystoplasmic accessory subunits. Despite the importance of such protein-protein interactions in VGIC function and assembly, their potential as sites for VGIC modulator development has been largely overlooked. Here, we develop meta-xylyl (m-xylyl) stapled peptides that target a prototypic VGIC high affinity protein-protein interaction, the interaction between the voltage-gated calcium channel (Ca V ) pore-forming subunit α-interaction domain (AID) and cytoplasmic β-subunit (Ca V β). We show using circular dichroism spectroscopy, X-ray crystallography, and isothermal titration calorimetry that the m-xylyl staples enhance AID helix formation are structurally compatible with native-like AID:Ca V β interactions and reduce the entropic penalty associated with AID binding to Ca V β. Importantly, electrophysiological studies reveal that stapled AID peptides act as effective inhibitors of the Ca V α 1 :Ca V β interaction that modulate Ca V function in an Ca V β isoform-selective manner. Together, our studies provide a proof-of-concept demonstration of the use of protein-protein interaction inhibitors to control VGIC function and point to strategies for improved AID-based Ca V modulator design.

  4. Preferential removal and immobilization of stable and radioactive cesium in contaminated fly ash with nanometallic Ca/CaO methanol suspension

    Energy Technology Data Exchange (ETDEWEB)

    Mallampati, Srinivasa Reddy, E-mail: srireddys@ulsan.ac.kr [Department of Civil and Environmental Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Mitoma, Yoshiharu, E-mail: mitomay@pu-hiroshima.ac.jp [Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara City, Hiroshima 727-0023 (Japan); Okuda, Tetsuji [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan); Sakita, Shogo [Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara City, Hiroshima 727-0023 (Japan); Simion, Cristian [Politehnica University of Bucharest, Department of Organic Chemistry, Bucharest 060042 (Romania)

    2014-08-30

    Graphical abstract: Schematic representation of possible mechanisms determining the Cs extraction and immobilization in fly ash during water, methanol or n-MCaS extraction. - Highlights: • nMCaS suspension for cesium extraction and immobilization in fly ash was developed. • Enhanced cesium immobilization was done by nanometallic Ca/CaO methanol suspension. • By SEM analysis the amount of cesium detectable on soil particle surface decreases. • Leachable cesium concentrations reduced, lower than the standard regulatory limit. • nMCaS unique and a highly potential amendment for the remediation of Cs. - Abstract: In this work, the capability of nanometallic Ca/CaO methanol suspension in removing and/or immobilizing stable ({sup 133}Cs) and radioactive cesium species ({sup 134}Cs and {sup 137}Cs) in contaminated fly ash was investigated. After a first methanol and second water washing yielded only 45% of {sup 133}Cs removal. While, after a first methanol washing, the second solvent with nanometallic Ca/CaO methanol suspension yielded simultaneous enhanced removal and immobilization about 99% of {sup 133}Cs. SEM-EDS analysis revealed that the mass percent of detectable {sup 133}Cs on the fly ash surface recorded a 100% decrease. When real radioactive cesium contaminated fly ash (containing an initial 14,040 Bq kg{sup −1134}Cs and {sup 137}Cs cumulated concentration) obtained from burning wastes from Fukushima were reduced to 3583 Bq kg{sup −1} after treatment with nanometallic Ca/CaO methanol suspension. Elution test conducted on the treated fly ash gave 100 Bq L{sup −1} total {sup 134}Cs and {sup 137}Cs concentrations in eluted solution. Furthermore, both ash content and eluted solution concentrations of {sup 134}Cs and {sup 137}Cs were much lower than the Japanese Ministry of the Environment regulatory limit of 8000 Bq kg{sup −1} and 150 Bq L{sup −1} respectively. The results of this study suggest that the nanometallic Ca/CaO methanol suspension is

  5. Ca2+ influx insensitive to organic Ca2+ entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

    NARCIS (Netherlands)

    Gouw, M. A.; Wilffert, B.; Wermelskirchen, D.; van Zwieten, P. A.

    1990-01-01

    We determined the contribution of intracellular Ca2+ to the noradrenaline (NA, 3 X 10(-5) mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+ release, we assumed that a Ca2+ influx component

  6. Capsicum annuum transcription factor WRKYa positively regulates defense response upon TMV infection and is a substrate of CaMK1 and CaMK2.

    Science.gov (United States)

    Huh, Sung Un; Lee, Gil-Je; Jung, Ji Hoon; Kim, Yunsik; Kim, Young Jin; Paek, Kyung-Hee

    2015-01-23

    Plants are constantly exposed to pathogens and environmental stresses. To minimize damage caused by these potentially harmful factors, plants respond by massive transcriptional reprogramming of various stress-related genes via major transcription factor families. One of the transcription factor families, WRKY, plays an important role in diverse stress response of plants and is often useful to generate genetically engineered crop plants. In this study, we carried out functional characterization of CaWRKYa encoding group I WRKY member, which is induced during hypersensitive response (HR) in hot pepper (Capsicum annuum) upon Tobacco mosaic virus (TMV) infection. CaWRKYa was involved in L-mediated resistance via transcriptional reprogramming of pathogenesis-related (PR) gene expression and affected HR upon TMV-P0 infection. CaWRKYa acts as a positive regulator of this defense system and could bind to the W-box of diverse PR genes promoters. Furthermore, we found Capsicum annuum mitogen-activated protein kinase 1 (CaMK1) and 2 (CaMK2) interacted with CaWRKYa and phosphorylated the SP clusters but not the MAPK docking (D)-domain of CaWRKYa. Thus, these results demonstrated that CaWRKYa was regulated by CaMK1 and CaMK2 at the posttranslational level in hot pepper.

  7. Inhibition of PKC-dependent extracellular Ca2+ entry contributes to the depression of contractile activity in long-term pressure-overloaded endothelium-denuded rat aortas

    International Nuclear Information System (INIS)

    Padilla, J.; López, R.M.; López, P.; Castillo, M.C.; Querejeta, E.; Ruiz, A.; Castillo, E.F.

    2014-01-01

    We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT 2 R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT 2 R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca 2+ -free medium or the subsequent tonic constrictions induced by the addition of Ca 2+ in the absence of agonists. Thus, the contractions induced by Ca 2+ release from intracellular stores and Ca 2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca 2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca 2+ . Neither levels of angiotensins nor of AT 2 R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca 2+ entry

  8. Control efficacy of Ca-containing foliar fertilizers on bitter pit in bagged 'Fuji' apple and effects on the Ca and N contents of apple fruits and leaves.

    Science.gov (United States)

    Yu, Xian-Mei; Wang, Jin-Zheng; Nie, Pei-Xian; Xue, Xaio-Min; Wang, Gui-Ping; An, Miao

    2018-04-20

    The preharvest application of Ca-containing foliar fertilizers can reduce bitter pit (BP) incidence in apples and improve fruit quality by increasing the Ca content and decreasing both the N content and the N/Ca ratio in fruits. In this study, we aimed to investigate the control efficacy of Ca-containing fertilizers on BP incidence and the effects on the Ca and N contents in bagged 'Fuji' apple by spraying the foliar fertilizer containing calcium chloride (CaCl 2 ), calcium nitrate [Ca(NO 3 ) 2 ] or calcium formate [Ca(HCOO) 2 ] at early stage [5 days after full bloom (DAFB) + 40 DAFB] and at late stage (80 DAFB + 125 DAFB). The BP incidences were reduced significantly with the reduce percentage of 43.2~73.0%, and the efficacy of spraying at early stage was significantly higher than that of spraying at late stage. The Ca content of bagged apple fruits was increased while the N content and N/Ca ratio were decreased after spraying Ca-containing foliar fertilizers, however, the Ca content, N content and N/Ca ratio of apple leaves were differentially influenced. The foliar fertilizer containing CaCl 2, Ca(NO 3 ) 2 or Ca(HCOO) 2 could be used at early stage to control BP in apple and improve the quality of bagged apple fruits. This article is protected by copyright. All rights reserved.

  9. Hierarchic stochastic modelling applied to intracellular Ca(2+ signals.

    Directory of Open Access Journals (Sweden)

    Gregor Moenke

    Full Text Available Important biological processes like cell signalling and gene expression have noisy components and are very complex at the same time. Mathematical analysis of such systems has often been limited to the study of isolated subsystems, or approximations are used that are difficult to justify. Here we extend a recently published method (Thurley and Falcke, PNAS 2011 which is formulated in observable system configurations instead of molecular transitions. This reduces the number of system states by several orders of magnitude and avoids fitting of kinetic parameters. The method is applied to Ca(2+ signalling. Ca(2+ is a ubiquitous second messenger transmitting information by stochastic sequences of concentration spikes, which arise by coupling of subcellular Ca(2+ release events (puffs. We derive analytical expressions for a mechanistic Ca(2+ model, based on recent data from live cell imaging, and calculate Ca(2+ spike statistics in dependence on cellular parameters like stimulus strength or number of Ca(2+ channels. The new approach substantiates a generic Ca(2+ model, which is a very convenient way to simulate Ca(2+ spike sequences with correct spiking statistics.

  10. Ca-Lignosulphonate and sclerotial viability of Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    MATTEO MONTANARI

    2012-01-01

    Full Text Available Lignosulphonates, low cost by-products of the pulping process, have shown suppressive effects against some diseases caused by soil-borne pathogens. In this study, the effect of 1.5% v/v calcium lignosulphonate (Ca-Ls amendment to two commercial potting mixes (peat + coconut fibres; PC; and municipal compost + peat + pumice; MCPP on the viability of Sclerotinia sclerotiorum sclerotia was investigated. Sclerotia were buried in the Ca-Ls amended substrates for 30 days. Non-amended PC and MCPP, sterile sand and sterile PC with and without Ca-Ls were used as controls. The viability of sclerotia recovered from PC and MCPP amended with Ca-Ls was reduced by 50 and 42% respectively compared to control treatments. Ca-Ls amendment decreased sclerotial viability by enhancing the activity of the indigenous mycoparasitic fungi, Fusarium oxysporum, Mucor spp. and Trichoderma spp. The biocontrol ability of Ca-Ls against sclerotia was due to the stimulation of microbial activity and is, therefore, strictly dependent on the microbial composition of the substrate.

  11. Pengaruh Kandungan Ca Pada Cao-zeolit Terhadap Kemampuan Adsorpsi Nitrogen

    OpenAIRE

    M Nasikin; Tania Surya Utami; Agustina TP Siahaan

    2002-01-01

    In industry, Ca zeolite is used as nitrogen selective adsorbent with the use of PSA (Pressure Swing Adsorption)/VSA (Vacuum Swing Adsorption) methods. Natural zeolite modified to be Cao-zeolite by ion exchange process using Ca(OH)2. Adsorption test was done on CaO-zeolite with different Ca concentration to understand how it's adsorption phenomena on oxygen and nitrogen. Adsorption test has been done for CaO-zeolite with Ca concentration = 0,682%, 0,849% and 1,244% to oxygen and nitrogen with ...

  12. A Common Ca2+-Driven Interdomain Module Governs Eukaryotic NCX Regulation

    Science.gov (United States)

    Giladi, Moshe; Sasson, Yehezkel; Fang, Xianyang; Hiller, Reuben; Buki, Tal; Wang, Yun-Xing; Hirsch, Joel A.; Khananshvili, Daniel

    2012-01-01

    Na+/Ca2+ exchanger (NCX) proteins mediate Ca2+-fluxes across the cell membrane to maintain Ca2+ homeostasis in many cell types. Eukaryotic NCX contains Ca2+-binding regulatory domains, CBD1 and CBD2. Ca2+ binding to a primary sensor (Ca3-Ca4 sites) on CBD1 activates mammalian NCXs, whereas CALX, a Drosophila NCX ortholog, displays an inhibitory response to regulatory Ca2+. To further elucidate the underlying regulatory mechanisms, we determined the 2.7 Å crystal structure of mammalian CBD12-E454K, a two-domain construct that retains wild-type properties. In conjunction with stopped-flow kinetics and SAXS (small-angle X-ray scattering) analyses of CBD12 mutants, we show that Ca2+ binding to Ca3-Ca4 sites tethers the domains via a network of interdomain salt-bridges. This Ca2+-driven interdomain switch controls slow dissociation of “occluded” Ca2+ from the primary sensor and thus dictates Ca2+ sensing dynamics. In the Ca2+-bound conformation, the interdomain angle of CBD12 is very similar in NCX and CALX, meaning that the interdomain distances cannot account for regulatory diversity in NCX and CALX. Since the two-domain interface is nearly identical among eukaryotic NCXs, including CALX, we suggest that the Ca2+-driven interdomain switch described here represents a general mechanism for initial conduction of regulatory signals in NCX variants. PMID:22768191

  13. Solid solubility of MgO in the calcium silicates of portland clinker. The effect of CaF2

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1992-03-01

    Full Text Available The solid solubility of MgO in the calcium silicates of portland clinker has been determined by XRD and XDS. The influence that the presence of CaF2 has on said solubility has also been verified. The solid solution limit of MgO in C3S at 1275 ºC lies at about 1.0% wt, where the triclinic form II stabilizes. The presence of CaF2 does not alter the maximum value of the MgO solubilized in that silicate, although there does take place the stabilization of the triclinic polymorph II at lower MgO contents (between 0.3 - 0.6% wt. The maximum amount of solubilized MgO in βC2 at 1.050 ºC lies around 0.5% wt. This value does not change by the presence of CaF2.Se ha determinado por DRX y EDX la solubilidad sólida del MgO en los silicatos cálcicos del clínker portland. Se ha comprobado, así mismo la influencia que sobre dicha solubilidad tiene la presencia de CaF2. El límite de disolución sólida del MgO en el C3S a 1.275º C se sitúa alrededor del 1,0% en peso, estabilizándose la forma triclínica II. La presencia de CaF2 no altera el valor máximo de MgO solubilizado en este silicato, aunque si se produce la estabilización del polimorfo triclínico II a contenidos menores de MgO (entre 0,3 – 0,6% en peso. La cantidad máxima de MgO solubilizado en e/ βC2S a 1.050 ºC se sitúa en torno al 0,5% en peso. Este valor no se ve modificado por la presencia de CaF2.

  14. Ca2+influx insensitive to organic Ca2+entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

    NARCIS (Netherlands)

    Gouw, M.A.M.; Wilffert, B.; Wermelskirchen, D.; Van Zwieten, P.A.

    1990-01-01

    We determined the contribution of intracellular Ca2+to the noradrenaline (NA, 3 x 10-5mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+release, we assumed that a Ca2+influx component contributes

  15. Modelling Ca2+ bound Troponin in Excitation Contraction Coupling

    Directory of Open Access Journals (Sweden)

    Henry G. Zot

    2016-09-01

    Full Text Available To explain disparate decay rates of cytosolic Ca2+ and structural changes in the thin filaments during a twitch, we model the time course of Ca2+ bound troponin (Tn resulting from the free Ca2+ transient of fast skeletal muscle. In fibers stretched beyond overlap, the decay of Ca2+ as measured by a change in fluo 3 fluorescence is significantly slower than the intensity decay of the meridional 1/38.5 nm-1 reflection of Tn; this is not simply explained by considering only the Ca2+ binding properties of Tn alone (Matsuo, T., Iwamoto, H., and Yagi, N. (2010. Biophys. J. 99, 193-200. We apply a comprehensive model that includes the known Ca2+ binding properties of Tn in the context of the thin filament with and without cycling crossbridges. Calculations based on the model predict that the transient of Ca2+ bound Tn correlates with either the fluo 3 time course in muscle with overlapping thin and thick filaments or the intensity of the meridional 1/38.5 nm-1 reflection in overstretched muscle. Hence, cycling crossbridges delay the dissociation of Ca2+ from Tn. Correlation with the fluo 3 fluorescence change is not causal given that the transient of Ca2+ bound Tn depends on sarcomere length, whereas the fluo-3 fluorescence change does not. Transient positions of tropomyosin calculated from the time course of Ca2+ bound Tn are in reasonable agreement with the transient of measured perturbations of the Tn repeat in overlap and non-overlap muscle preparations.

  16. Exchange stiffness of Ca-doped YIG

    Science.gov (United States)

    Avgin, I.; Huber, D. L.

    1994-05-01

    An effective medium theory for the zero-temperature exchange stiffness of uncompensated Ca-doped YIG is presented. The theory is based on the assumption that the effect of the Ca impurities is to produce strong, random ferromagnetic interactions between spins on the a and d sublattices. In the simplest version of the theory, a fraction, x, of the ad exchange integrals are large and positive, x being related to the Ca concentration. The stiffness is calculated as function of x for arbitrary perturbed ad exchange integral, Jxad. For Jxad≳(1/5)‖8Jaa+3Jdd‖, with Jaa and Jdd denoting the aa and dd exchange integrals, respectively, there is a critical concentration, Xc, such that when x≳Xc, the stiffness is complex. It is suggested that Xc delineates the region where there are significant departures from colinearity in the ground state of the Fe spins. Extension of the theory to a model where the Ca doping is assumed to generate Fe4+ ions on the tetrahedral sites is discussed. Possible experimental tests of the theory are mentioned.

  17. Benthic foraminiferal Mn / Ca ratios reflect microhabitat preferences

    Science.gov (United States)

    Koho, Karoliina A.; de Nooijer, Lennart J.; Fontanier, Christophe; Toyofuku, Takashi; Oguri, Kazumasa; Kitazato, Hiroshi; Reichart, Gert-Jan

    2017-06-01

    The Mn / Ca of calcium carbonate tests of living (rose-Bengal-stained) benthic foraminifera (Elphidium batialis, Uvigerina spp., Bolivina spissa, Nonionellina labradorica and Chilostomellina fimbriata) were determined in relation to pore water manganese (Mn) concentrations for the first time along a bottom water oxygen gradient across the continental slope along the NE Japan margin (western Pacific). The local bottom water oxygen (BWO) gradient differs from previous field study sites focusing on foraminiferal Mn / Ca and redox chemistry, therefore allowing further resolution of previously observed trends. The Mn / Ca ratios were analysed using laser ablation inductively coupled plasma-mass spectrometer (ICP-MS), allowing single-chamber determination of Mn / Ca. The incorporation of Mn into the carbonate tests reflects environmental conditions and is not influenced by ontogeny. The inter-species variability in Mn / Ca reflected foraminiferal in-sediment habitat preferences and associated pore water chemistry but also showed large interspecific differences in Mn partitioning. At each station, Mn / Ca ratios were always lower in the shallow infaunal E. batialis, occupying relatively oxygenated sediments, compared to intermediate infaunal species, Uvigerina spp. and B. spissa, which were typically found at greater depth, under more reducing conditions. The highest Mn / Ca was always recorded by the deep infaunal species N. labradorica and C. fimbriata. Our results suggest that although partitioning differs, Mn / Ca ratios in the intermediate infaunal taxa are promising tools for palaeoceanographic reconstructions as their microhabitat exposes them to higher variability in pore water Mn, thereby making them relatively sensitive recorders of redox conditions and/or bottom water oxygenation.

  18. Is tissue CA125 expression in epithelial ovarian adenocarcinoma heterogenic?

    DEFF Research Database (Denmark)

    Sparholt, Morten H; Høgdall, Claus K; Nedergaard, Lotte

    2013-01-01

    To evaluate if heterogeneity of tissue cancer antigen 125 (CA125) expression is present in epithelial serous adenocarcinomas. Furthermore, to investigate whether there is a correlation between levels of CA125 tissue expression, serum level of CA125, stage, and grade. A total of 10 patients...... diagnosed with serous ovarian adenocarcinomas were included. Preoperative blood samples were collected to determine serum CA125 levels. Tumor tissue from primary surgery was collected and processed for immunohistochemical analyses. CA125 was expressed in varying degrees in tumor tissues from all patients....... Mean tissue CA125 expression for each patient ranged from 36% to 98%. Intrapatient variations in tissue expression ranged from 10% to 90% point. No significant correlations between levels of CA125 tissue expression, serum level of CA125, stage, and grade were found. We found that the tissue expression...

  19. The value of combined tumor markers of CEA, CA19-9 and CA242 for diagnosis of patients with colorectal cancer

    International Nuclear Information System (INIS)

    Hu Hongyong; Tang Jianlin; Li Yuying; Gao Liuyan; Tang Xiuping

    2010-01-01

    Objective: To explore the clinical value of serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 242 (CA242) levels in patients with colorectal cancer using single item and multi-items determination. Methods: Serum levels of CEA, CA19-9 and CA242 were measured with chemiuminescent immunoassay (CLIA) and radioimmunoassay (RIA) in 89 cases of colorectal cancer patients and 50 cases of normal people. Results: The serum levels of this three tumor markers were significantly higher than those in the control group (t=3.97, 3.55 and 7.44, P 2 =30.552, 32.076, 18.365, 7.130 and 8.862, P<0.01). Combined determination of those three could enhance the sensitivity (85.39%) and accuracy (90.60%), but the specificity was decreased (88.00%). Conclusion: Determination of serum CEA, CA19-9 and CA242 levels are valuable for the diagnosis and evaluation of patients with colorectal cancer, and the diagnosis sensitivity can be enhanced with combined determinations. (authors)

  20. Cuento: Sangre de caña

    Directory of Open Access Journals (Sweden)

    Segundo Benjamín Corredor

    1967-09-01

    Full Text Available El viento se convertía en murmullo contra las hojas de los cañaverales y contra los techos semipelados del rancho. También menguaba el calor que maduraba los plantíos de caña y que hacía más efusiva la sangre de los moradores.

  1. Epigallocatechin-3-gallate increases intracellular [Ca2+] in U87 cells mainly by influx of extracellular Ca2+ and partly by release of intracellular stores.

    Science.gov (United States)

    Kim, Hee Jung; Yum, Keun Sang; Sung, Jong-Ho; Rhie, Duck-Joo; Kim, Myung-Jun; Min, Do Sik; Hahn, Sang June; Kim, Myung-Suk; Jo, Yang-Hyeok; Yoon, Shin Hee

    2004-02-01

    Green tea has been receiving considerable attention as a possible preventive agent against cancer and cardiovascular disease. Epigallocatechin-3-gallate (EGCG) is a major polyphenol component of green tea. Using digital calcium imaging and an assay for [3H]-inositol phosphates, we determined whether EGCG increases intracellular [Ca2+] ([Ca2+]i) in non-excitable human astrocytoma U87 cells. EGCG induced concentration-dependent increases in [Ca2+]i. The EGCG-induced [Ca2+]i increases were reduced to 20.9% of control by removal of extracellular Ca2+. The increases were also inhibited markedly by treatment with the non-specific Ca2+ channel inhibitors cobalt (3 mM) for 3 min and lanthanum (1 mM) for 5 min. The increases were not significantly inhibited by treatment for 10 min with the L-type Ca2+ channel blocker nifedipine (100 nM). Treatment with the inhibitor of endoplasmic reticulum Ca2+-ATPase thapsigargin (1 micro M) also significantly inhibited the EGCG-induced [Ca2+]i increases. Treatment for 15 min with the phospholipase C (PLC) inhibitor neomycin (300 micro M) attenuated the increases significantly, while the tyrosine kinase inhibitor genistein (30 micro M) had no effect. EGCG increased [3H]-inositol phosphates formation via PLC activation. Treatment for 10 min with mefenamic acid (100 micro M) and flufenamic acid (100 micro M), derivatives of diphenylamine-2-carboxylate, blocked the EGCG-induced [Ca2+]i increase in non-treated and thapsigargin-treated cells but indomethacin (100 micro M) did not affect the increases. Collectively, these data suggest that EGCG increases [Ca2+]i in non-excitable U87 cells mainly by eliciting influx of extracellular Ca2+ and partly by mobilizing intracellular Ca2+ stores by PLC activation. The EGCG-induced [Ca2+]i influx is mediated mainly through channels sensitive to diphenylamine-2-carboxylate derivatives.

  2. Long term potentiation, but not depression, in interlamellar hippocampus CA1.

    Science.gov (United States)

    Sun, Duk-Gyu; Kang, Hyeri; Tetteh, Hannah; Su, Junfeng; Lee, Jihwan; Park, Sung-Won; He, Jufang; Jo, Jihoon; Yang, Sungchil; Yang, Sunggu

    2018-03-26

    Synaptic plasticity in the lamellar CA3 to CA1 circuitry has been extensively studied while interlamellar CA1 to CA1 connections have not yet received much attention. One of our earlier studies demonstrated that axons of CA1 pyramidal neurons project to neighboring CA1 neurons, implicating information transfer along a longitudinal interlamellar network. Still, it remains unclear whether long-term synaptic plasticity is present within this longitudinal CA1 network. Here, we investigate long-term synaptic plasticity between CA1 pyramidal cells, using in vitro and in vivo extracellular recordings and 3D holography glutamate uncaging. We found that the CA1-CA1 network exhibits NMDA receptor-dependent long-term potentiation (LTP) without direction or layer selectivity. By contrast, we find no significant long-term depression (LTD) under various LTD induction protocols. These results implicate unique synaptic properties in the longitudinal projection suggesting that the interlamellar CA1 network could be a promising structure for hippocampus-related information processing and brain diseases.

  3. Rapid recycling of Ca2+ between IP3-sensitive stores and lysosomes.

    Directory of Open Access Journals (Sweden)

    Cristina I López Sanjurjo

    Full Text Available Inositol 1,4,5-trisphosphate (IP3 evokes release of Ca2+ from the endoplasmic reticulum (ER, but the resulting Ca2+ signals are shaped by interactions with additional intracellular organelles. Bafilomycin A1, which prevents lysosomal Ca2+ uptake by inhibiting H+ pumping into lysosomes, increased the amplitude of the initial Ca2+ signals evoked by carbachol in human embryonic kidney (HEK cells. Carbachol alone and carbachol in combination with parathyroid hormone (PTH evoke Ca2+ release from distinct IP3-sensitive Ca2+ stores in HEK cells stably expressing human type 1 PTH receptors. Bafilomycin A1 similarly exaggerated the Ca2+ signals evoked by carbachol or carbachol with PTH, indicating that Ca2+ released from distinct IP3-sensitive Ca2+ stores is sequestered by lysosomes. The Ca2+ signals resulting from store-operated Ca2+ entry, whether evoked by thapsigargin or carbachol, were unaffected by bafilomycin A1. Using Gd3+ (1 mM to inhibit both Ca2+ entry and Ca2+ extrusion, HEK cells were repetitively stimulated with carbachol to assess the effectiveness of Ca2+ recycling to the ER after IP3-evoked Ca2+ release. Blocking lysosomal Ca2+ uptake with bafilomycin A1 increased the amplitude of each carbachol-evoked Ca2+ signal without affecting the rate of Ca2+ recycling to the ER. This suggests that Ca2+ accumulated by lysosomes is rapidly returned to the ER. We conclude that lysosomes rapidly, reversibly and selectively accumulate the Ca2+ released by IP3 receptors residing within distinct Ca2+ stores, but not the Ca2+ entering cells via receptor-regulated, store-operated Ca2+ entry pathways.

  4. Rapid recycling of Ca2+ between IP3-sensitive stores and lysosomes.

    Science.gov (United States)

    López Sanjurjo, Cristina I; Tovey, Stephen C; Taylor, Colin W

    2014-01-01

    Inositol 1,4,5-trisphosphate (IP3) evokes release of Ca2+ from the endoplasmic reticulum (ER), but the resulting Ca2+ signals are shaped by interactions with additional intracellular organelles. Bafilomycin A1, which prevents lysosomal Ca2+ uptake by inhibiting H+ pumping into lysosomes, increased the amplitude of the initial Ca2+ signals evoked by carbachol in human embryonic kidney (HEK) cells. Carbachol alone and carbachol in combination with parathyroid hormone (PTH) evoke Ca2+ release from distinct IP3-sensitive Ca2+ stores in HEK cells stably expressing human type 1 PTH receptors. Bafilomycin A1 similarly exaggerated the Ca2+ signals evoked by carbachol or carbachol with PTH, indicating that Ca2+ released from distinct IP3-sensitive Ca2+ stores is sequestered by lysosomes. The Ca2+ signals resulting from store-operated Ca2+ entry, whether evoked by thapsigargin or carbachol, were unaffected by bafilomycin A1. Using Gd3+ (1 mM) to inhibit both Ca2+ entry and Ca2+ extrusion, HEK cells were repetitively stimulated with carbachol to assess the effectiveness of Ca2+ recycling to the ER after IP3-evoked Ca2+ release. Blocking lysosomal Ca2+ uptake with bafilomycin A1 increased the amplitude of each carbachol-evoked Ca2+ signal without affecting the rate of Ca2+ recycling to the ER. This suggests that Ca2+ accumulated by lysosomes is rapidly returned to the ER. We conclude that lysosomes rapidly, reversibly and selectively accumulate the Ca2+ released by IP3 receptors residing within distinct Ca2+ stores, but not the Ca2+ entering cells via receptor-regulated, store-operated Ca2+ entry pathways.

  5. Ultrastructural and immunohistochemical localization of plasma membrane Ca2+-ATPase 4 in Ca2+-transporting epithelia

    DEFF Research Database (Denmark)

    Alexander, R Todd; Beggs, Megan R; Zamani, Reza

    2015-01-01

    role in transcellular Ca(2+) flux and investigated the localization and regulation of Pmca4 in Ca(2+)-transporting epithelia. Using antibodies directed specifically against Pmca4, we found it expressed only in the smooth muscle layer of mouse and human intestine, while pan-specific Pmca antibodies...... the cortical thick ascending limbs, macula densa, and early distal tubules as well as smooth muscle layers surrounding renal vessels. In human kidney, a similar pattern of distribution was observed, with highest PMCA4 expression in NCC positive tubules. Electron microscopy demonstrated Pmca4 localization...... in distal nephron cells at both the basolateral membrane and intracellular perinuclear compartments, but not submembranous vesicles, suggesting rapid trafficking to the plasma membrane is unlikely to occur in vivo. Pmca4 expression was not altered by perturbations in Ca(2+) balance, pointing...

  6. Water-bearing, high-pressure Ca-silicates

    Science.gov (United States)

    Németh, Péter; Leinenweber, Kurt; Ohfuji, Hiroaki; Groy, Thomas; Domanik, Kenneth J.; Kovács, István J.; Kovács, Judit S.; Buseck, Peter R.

    2017-07-01

    Water-bearing minerals provide fundamental knowledge regarding the water budget of the mantle and are geophysically significant through their influence on the rheological and seismic properties of Earth's interior. Here we investigate the CaO-SiO2-H2O system at 17 GPa and 1773 K, corresponding to mantle transition-zone condition, report new high-pressure (HP) water-bearing Ca-silicates and reveal the structural complexity of these phases. We document the HP polymorph of hartrurite (Ca3SiO5), post-hartrurite, which is tetragonal with space group P4/ncc, a = 6.820 (5), c = 10.243 (8) Å, V = 476.4 (8) Å3, and Z = 4, and is isostructural with Sr3SiO5. Post-hartrurite occurs in hydrous and anhydrous forms and coexists with larnite (Ca2SiO4), which we find also has a hydrous counterpart. Si is 4-coordinated in both post-hartrurite and larnite. In their hydrous forms, H substitutes for Si (4H for each Si; hydrogrossular substitution). Fourier transform infrared (FTIR) spectroscopy shows broad hydroxyl absorption bands at ∼3550 cm-1 and at 3500-3550 cm-1 for hydrous post-hartrurite and hydrous larnite, respectively. Hydrous post-hartrurite has a defect composition of Ca2.663Si0.826O5H1.370 (5.84 weight % H2O) according to electron-probe microanalysis (EPMA), and the Si deficiency relative to Ca is also observed in the single-crystal data. Hydrous larnite has average composition of Ca1.924Si0.851O4H0.748 (4.06 weight % H2O) according to EPMA, and it is in agreement with the Si occupancy obtained using X-ray data collected on a single crystal. Superlattice reflections occur in electron-diffraction patterns of the hydrous larnite and could indicate crystallographic ordering of the hydroxyl groups and their associated cation defects. Although textural and EPMA-based compositional evidence suggests that hydrous perovskite may occur in high-Ca-containing (or low silica-activity) systems, the FTIR measurement does not show a well-defined hydroxyl absorption band for this

  7. Photonucleon reactions in 40Ca at intermediate energies

    International Nuclear Information System (INIS)

    Adler, J.-O.; Bulow, B.; Jonsson, G.G.; Lindgren, K.

    1976-01-01

    The yields of the reactions 40 Ca(γ,n) 39 Ca* and 40 Ca(γ,p) 39 K* to the first three excited states have been measured for bremsstrahlung with end-point energies in the region 100-750 MeV. The C 2 S values for the first excited state were deduced from the pion photoproduction contribution to the measured yields. (Auth.)

  8. 6/sup +/ isomer state in /sup 46/Ca

    Energy Technology Data Exchange (ETDEWEB)

    Bizzeti, P G; Maurenzig, P R; Poggi, G [Florence Univ. (Italy). Istituto di Fisica; Lo Bianco, G [Milan Univ. (Italy). Istituto di Fisica

    1975-01-11

    The decay of the expected isomer, obtained from the reaction /sup 48/Ca(p,p2n)/sup 46/Ca, has been observed as a delayed activity after bombardment of a 97.2% enriched /sup 48/CaC0/sub 3/ target with 35 MeV protons. The experimental apparatus used at AUF cyclotron of Milan is described. Data are reported and discussed.

  9. Trivial topological phase of CaAgP and the topological nodal-line transition in CaAg (P1 -xA sx)

    Science.gov (United States)

    Xu, N.; Qian, Y. T.; Wu, Q. S.; Autès, G.; Matt, C. E.; Lv, B. Q.; Yao, M. Y.; Strocov, V. N.; Pomjakushina, E.; Conder, K.; Plumb, N. C.; Radovic, M.; Yazyev, O. V.; Qian, T.; Ding, H.; Mesot, J.; Shi, M.

    2018-04-01

    By performing angle-resolved photoemission spectroscopy and first-principles calculations, we address the topological phase of CaAgP and investigate the topological phase transition in CaAg (P1 -xA sx) . We reveal that in CaAgP, the bulk band gap and surface states with a large bandwidth are topologically trivial, in agreement with hybrid density functional theory calculations. The calculations also indicate that application of "negative" hydrostatic pressure can transform trivial semiconducting CaAgP into an ideal topological nodal-line semimetal phase. The topological transition can be realized by partial isovalent P/As substitution at x =0.38 .

  10. Structure determinations for Ca3Ti2O7, Ca4Ti3O10, Ca3.6Sr0.4Ti3O10 and a refinement of Sr3Ti2O7

    International Nuclear Information System (INIS)

    Elcombe, M.M.; Kisi, E.H.; Hawkins, K.D.; White, T.J.; Goodman, P.; Matheson, S.

    1991-01-01

    The structures of the orthorhombic Ruddlesden-Popper (A n+1 B n X 3n+1 ) phases Ca 3 Ti 2 O 7 (n=2) refined from neutron powder diffraction data at λ=1.893 A. They consist of coherent intergrowths of perovskite (CaTiO 3 ) blocks, n TiO 6 octahedra thick, with single layers of CaO having a distorted NaCl configuration. TiO 6 octahedra are tilted and distorted in a very similar fashion to those in CaTiO 3 (n=∞). This fact was used to determine the space groups of the layered structures. Convergent-beam electron diffraction patterns are best matched by calculations in the above space groups which are thus confirmed. Octahedral tilt angles increase slightly in the sequence n=2, 3, ∞. Strontium addition reduces the octahedral tilt angles because of preferential substitution of Sr on the Ca sites within the perovskite blocks of Ca 4 Ti 3 O 10 . The algorithm used to produce starting models for structure refinements is thought to be generally applicable to Ruddlesden-Popper and possibly other layered perovskite structures. It furnishes the predictions: (a) all n-even compounds in the Ca n+1 Ti n O 3n+1 series will have space group Ccm2 1 , (b) all n-odd compounds in this series will have space group Pcab, (c) all A n+1 B n X 3n+1 series for which the n=∞ end member (ABX 3 ) is isostructural with CaTiO 3 will be isostructural with the compounds reported above (e.g. Ca n+1 Zr n O 3n+1 ). (orig./WL)

  11. Punta Pitt Stable Isotope and Ion Data (delta 18O, delta 13C, Cd/Ca, Mn/Ca) for 1936 to 1982.5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File contains data presented by Shen et al. (1992a). Table includes d18O, d13C, Cd/Ca, Mn/Ca, and Ba/Ca data from a 2m coral head and, for comparison, SST records...

  12. caGrid 1.0: a Grid enterprise architecture for cancer research.

    Science.gov (United States)

    Oster, Scott; Langella, Stephen; Hastings, Shannon; Ervin, David; Madduri, Ravi; Kurc, Tahsin; Siebenlist, Frank; Covitz, Peter; Shanbhag, Krishnakant; Foster, Ian; Saltz, Joel

    2007-10-11

    caGrid is the core Grid architecture of the NCI-sponsored cancer Biomedical Informatics Grid (caBIG) program. The current release, caGrid version 1.0, is developed as the production Grid software infrastructure of caBIG. Based on feedback from adopters of the previous version (caGrid 0.5), it has been significantly enhanced with new features and improvements to existing components. This paper presents an overview of caGrid 1.0, its main components, and enhancements over caGrid 0.5.

  13. Mg/Ca and Sr/Ca as novel geochemical proxies for understanding sediment transport processes within coral reefs

    Science.gov (United States)

    Gacutan, J.; Vila-Concejo, A.; Nothdurft, L. D.; Fellowes, T. E.; Cathey, H. E.; Opdyke, B. N.; Harris, D. L.; Hamylton, S.; Carvalho, R. C.; Byrne, M.; Webster, J. M.

    2017-10-01

    Sediment transport is a key driver of reef zonation and biodiversity, where an understanding of sediment dynamics gives insights into past reef processes and allows the prediction of geomorphic responses to changing environmental conditions. However, modal conditions within the back-reef seldom promote sediment transport, hence direct observation is inherently difficult. Large benthic foraminifera (LBF) have previously been employed as 'tracers' to infer sediment transport pathways on coral reefs, as their habitat is largely restricted to the algal flat and post-mortem, their calcium carbonate test is susceptible to sediment transport forces into the back-reef. Foraminiferal test abundance and post-depositional test alteration have been used as proxies for sediment transport, although the resolution of these measures becomes limited by low test abundance and the lack of variation within test alteration. Here we propose the novel use of elemental ratios as a proxy for sediment transport. Two species, Baculogypsina sphaerulata and Calcarina capricornia, were analysed using a taphonomic index within One Tree and Lady Musgrave reefs, Great Barrier Reef (Australia). Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine Mg/Ca and Sr/Ca and these ratios were compared with taphonomic data. Decreases in test Mg/Ca accompany increases in Sr/Ca in specimens from algal-flat to lagoonal samples in both species, mirroring trends indicated by taphonomic values, therefore indicating a relationship with test alteration. To delineate mechanisms driving changes in elemental ratios, back-scattered electron (BSE) images, elemental mapping and in situ quantitative spot analyses by electron microprobe microanalysis (EPMA) using wavelength dispersive X-ray spectrometers (WDS) were performed on un-altered algal flat and heavily abraded tests for both species. EPMA analyses reveal heterogeneity in Mg/Ca between spines and the test wall, implying the loss of

  14. The cumulative analgesic effect of repeated electroacupuncture involves synaptic remodeling in the hippocampal CA3 region☆

    Science.gov (United States)

    Xu, Qiuling; Liu, Tao; Chen, Shuping; Gao, Yonghui; Wang, Junying; Qiao, Lina; Liu, Junling

    2012-01-01

    In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanli (ST36) and Yanglingquan (GB34) once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold (paw withdrawal latency) was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptic cleft width and thinning of the postsynaptic density, and it significantly suppressed the down-regulation of intracellular calcium/calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. PMID:25657670

  15. Thermoluminescence properties of CaO powder obtained from chicken eggshells

    International Nuclear Information System (INIS)

    Nagabhushana, K.R.; Lokesha, H.S.; Satyanarayana Reddy, S.; Prakash, D.; Veerabhadraswamy, M.; Bhagyalakshmi, H.; Jayaramaiah, J.R.

    2017-01-01

    Eggshell wastage has created serious problem in disposal of the food processing industry which has been triggered the thoughts of researchers to use wasted eggshells as good source of calcium. In the present work, calcium oxide (CaO) has been synthesized by combustion process in furnace (F–CaO) and microwave oven (M–CaO) using the source of chicken eggshells. The obtained F–CaO and M–CaO are characterized by XRD, SEM with EDX and thermoluminescence (TL) technique. XRD pattern of both the samples show cubic phase with crystallite size 45–52 nm. TL glow curves are recorded for various gamma radiation dose (300–4000 Gy). Two TL glows, a small peak at 424 K and stronger peak at 597 K are observed. TL response of M–CaO is 2.67 times higher than F–CaO sample. TL kinetic parameters are calculated by computerized curve deconvolution analysis (CCDA) and discussed. - Highlights: • Calcium oxide powders have been synthesized using chicken egg shells as raw material. • Crystallite size was found to be 45–52 nm. • CaO derived from eggshells shows good thermoluminescence TL response. • TL response of the M–CaO is 2.67 times higher than the F–CaO sample.

  16. CaPiTo: protocol stacks for services

    DEFF Research Database (Denmark)

    Gao, Han; Nielson, Flemming; Nielson, Hanne Riis

    2011-01-01

    CaPiTo allows the modelling of service-oriented applications using process algebras at three levels of abstraction. The abstract level focuses on the key functionality of the services; the plug-in level shows how to obtain security using standardised protocol stacks; finally, the concrete level...... allows to consider how security is obtained using asymmetric and symmetric cryptographic primitives. The CaPiTo approach therefore caters for a variety of developers that need to cooperate on designing and implementing service-oriented applications. We show how to formally analyse CaPiTo specifications...

  17. Semiconductor-metal transition in CaMO3-CaTiO2 (M-Ru,Ir) systems

    International Nuclear Information System (INIS)

    Lazarev, V.B.; Shaplygin, I.S.

    1982-01-01

    Properties of CaRusub(x)Tisub(1-x)Osub(3) and CaIsub(2x)Tisub(1-x)Osub(3) solid solutions were studied in the whole range of concentrations by the methods of X-ray diffraction, electric conductivity and magnetic susceptibility. It was ascertained that the transition of semiconductor-metal type proceeded in the both families of solid solutions at x approximately 0.77 and 0.85 respectively and was accompanied by the change of structural type of solid solutions

  18. Preparation and Supercooling Modification of Salt Hydrate Phase Change Materials Based on CaCl₂·2H₂O/CaCl₂.

    Science.gov (United States)

    Xu, Xiaoxiao; Dong, Zhijun; Memon, Shazim Ali; Bao, Xiaohua; Cui, Hongzhi

    2017-06-23

    Salt hydrates have issues of supercooling when they are utilized as phase change materials (PCMs). In this research, a new method was adopted to prepare a salt hydrate PCM (based on a mixture of calcium chloride dihydrate and calcium chloride anhydrous) as a novel PCM system to reduce the supercooling phenomenon existing in CaCl₂·6H₂O. Six samples with different compositions of CaCl₂ were prepared. The relationship between the performance and the proportion of calcium chloride dihydrate (CaCl₂·2H₂O) and calcium chloride anhydrous (CaCl₂) was also investigated. The supercooling degree of the final PCM reduced with the increase in volume of CaCl₂·2H₂O during its preparation. The PCM obtained with 66.21 wt % CaCl₂·2H₂O reduced the supercooling degree by about 96.8%. All six samples, whose ratio of CaCl₂·2H₂O to (CaCl₂ plus CaCl₂·2H₂O) was 0%, 34.03%, 53.82%, 76.56%, 90.74%, and 100% respectively, showed relatively higher enthalpy (greater than 155.29 J/g), and have the possibility to be applied in buildings for thermal energy storage purposes. Hence, CaCl₂·2H₂O plays an important role in reducing supercooling and it can be helpful in adjusting the solidification enthalpy. Thereafter, the influence of adding different percentages of Nano-SiO₂ (0.1 wt %, 0.3 wt %, 0.5 wt %) in reducing the supercooling degree of some PCM samples was investigated. The test results showed that the supercooling of the salt hydrate PCM in Samples 6 and 5 reduced to 0.2 °C and 0.4 °C respectively. Finally, the effect of the different cooling conditions, including frozen storage (-20 °C) and cold storage (5 °C), that were used to prepare the salt hydrate PCM was considered. It was found that both cooling conditions are effective in reducing the supercooling degree of the salt hydrate PCM. With the synergistic action of the two materials, the performance and properties of the newly developed PCM systems were better especially in terms of reducing

  19. Aqueous solvation of Mg(ii) and Ca(ii): A Born-Oppenheimer molecular dynamics study of microhydrated gas phase clusters

    Science.gov (United States)

    León-Pimentel, C. I.; Amaro-Estrada, J. I.; Hernández-Cobos, J.; Saint-Martin, H.; Ramírez-Solís, A.

    2018-04-01

    The hydration features of [Mg(H2O)n ] 2 + and [Ca(H2O)n ] 2 + clusters with n = 3-6, 8, 18, and 27 were studied by means of Born-Oppenheimer molecular dynamics simulations at the B3LYP/6-31+G** level of theory. For both ions, it is energetically more favorable to have all water molecules in the first hydration shell when n ≤ 6, but stable lower coordination average structures with one water molecule not directly interacting with the ion were found for Mg2+ at room temperature, showing signatures of proton transfer events for the smaller cation but not for the larger one. A more rigid octahedral-type structure for Mg2+ than for Ca2+ was observed in all simulations, with no exchange of water molecules to the second hydration shell. Significant thermal effects on the average structure of clusters were found: while static optimizations lead to compact, spherically symmetric hydration geometries, the effects introduced by finite-temperature dynamics yield more prolate configurations. The calculated vibrational spectra are in agreement with infrared spectroscopy results. Previous studies proposed an increase in the coordination number (CN) from six to eight water molecules for [Ca(H2O)n ] 2 + clusters when n ≥ 12; however, in agreement with recent measurements of binding energies, no transition to a larger CN was found when n > 8. Moreover, the excellent agreement found between the calculated extended X-ray absorption fine structure spectroscopy spectra for the larger cluster and the experimental data of the aqueous solution supports a CN of six for Ca2+.

  20. Performance characteristics of CA 19-9 radioimmunoassay and clinical significance of serum CA 19-9 assay in patients with malignancy

    International Nuclear Information System (INIS)

    Kim, S.E.; Shong, Y.K.; Cho, B.Y.; Kim, N.K.; Koh, C.S.; Lee, M.H.; Hong, K.S.

    1985-01-01

    To evaluate the performance characteristics of CA 19-9 radioimmunoassay and the clinical significance of serum CA 19-9 assay in patients with malignancy, serum CA 19-9 levels were measured by radioimmunoassay using monoclonal antibody in 135 normal controls, 81 patients with various untreated malignancy, 9 patients of postoperative colon cancer without recurrence and 20 patients with benign gastrointestinal diseases, who visited Seoul National University Hospital from June, 1984 to March, 1985. (Author)

  1. Perovskite phases in the systems Asup(II)O-Usup(VI)O/sub 3/. 2. On the system A/sub 2/sup(II)Bsup(II)Usup(VI)O/sub 6/, with Asup(II), Bsup(II) = Ba, Sr, Ca

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, A J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1980-07-01

    Studies on the system A/sub 2/sup(II)Bsup(II)Usup(VI)O/sub 6/ with Asup(II), Bsup(II) = Ba, Sr, Ca or combinations of these have shown that the alkaline earth ions cannot substitute each other in all proportions. The perovskites were studied by X-ray diffraction and vibrational spectroscopic methods. The lattice vibration region of the far infrared spectra proved to be of particular value in providing information on the occupancy of the A and B sites. Analysis of the spectra shows that, in the majority of cases, contary to the geometrical predictions some of the larger alkaline earth ions occupy the six-coordinated B sites and some smaller ions the A positions. The number of ions that take in this A reversible B site-exchange can amount to 20%, but is normally smaller.

  2. [Endoplasmic-mitochondrial Ca(2+)-functional unit: dependence of respiration of secretory cells on activity of ryanodine- and IP3 - sensitive Ca(2+)-channels].

    Science.gov (United States)

    Velykopols'ka, O Iu; Man'ko, B O; Man'ko, V V

    2012-01-01

    Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.

  3. Burst activity and ultrafast activation kinetics of CaV1.3 Ca²⁺ channels support presynaptic activity in adult gerbil hair cell ribbon synapses.

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Holley, Matthew C; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2013-08-15

    Auditory information transfer to afferent neurons relies on precise triggering of neurotransmitter release at the inner hair cell (IHC) ribbon synapses by Ca²⁺ entry through CaV1.3 Ca²⁺ channels. Despite the crucial role of CaV1.3 Ca²⁺ channels in governing synaptic vesicle fusion, their elementary properties in adult mammals remain unknown. Using near-physiological recording conditions we investigated Ca²⁺ channel activity in adult gerbil IHCs. We found that Ca²⁺ channels are partially active at the IHC resting membrane potential (-60 mV). At -20 mV, the large majority (>70%) of Ca²⁺ channel first openings occurred with an estimated delay of about 50 μs in physiological conditions, with a mean open time of 0.5 ms. Similar to other ribbon synapses, Ca²⁺ channels in IHCs showed a low mean open probability (0.21 at -20 mV), but this increased significantly (up to 0.91) when Ca²⁺ channel activity switched to a bursting modality. We propose that IHC Ca²⁺ channels are sufficiently rapid to transmit fast signals of sound onset and support phase-locking. Short-latency Ca²⁺ channel opening coupled to multivesicular release would ensure precise and reliable signal transmission at the IHC ribbon synapse.

  4. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels.

    Directory of Open Access Journals (Sweden)

    Ana Laura Sanchez-Sandoval

    Full Text Available Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA and low-voltage (LVA activated calcium channels is around 30-40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.

  5. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels

    Science.gov (United States)

    Sanchez-Sandoval, Ana Laura; Herrera Carrillo, Zazil; Díaz Velásquez, Clara Estela; Delgadillo, Dulce María; Rivera, Heriberto Manuel

    2018-01-01

    Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30–40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers. PMID:29474447

  6. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels.

    Science.gov (United States)

    Sanchez-Sandoval, Ana Laura; Herrera Carrillo, Zazil; Díaz Velásquez, Clara Estela; Delgadillo, Dulce María; Rivera, Heriberto Manuel; Gomora, Juan Carlos

    2018-01-01

    Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30-40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.

  7. Raman study of CaDNA films as a function of water content and excess CaCl2 concentration: Stability of the B conformation.

    Science.gov (United States)

    Schwenker, Megan; Marlowe, Robert; Lee, Scott; Rupprecht, Allan

    2006-03-01

    Highly oriented, wet-spun films of CaDNA expand in the direction perpendicular to the helical axis as the hydration of the film is increased. CaDNA films with a high CaCl2 content show an unexpected shrinkage at a relative humidity of about 93%. We have performed Raman experiments on CaDNA films as a function of both water content and excess CaCl2 concentration in order to determine if this unexpected shrinkage might be related to a conformational transition of the DNA molecules. We find that the DNA molecules remain in the B conformation for all salt contents down to a relative humidity of 59%.

  8. EFFECT OF FERRITE PHASE ON THE FORMATION AND COEXISTENCE OF 3CaO.3Al₂O₃.CaSO₄ AND 3CaO.SiO₂ MINERALS

    Directory of Open Access Journals (Sweden)

    Xiaolei Lu

    2017-12-01

    Full Text Available The effect of ferrite on the formation and coexistence of 3CaO.3Al₂O₃.CaSO₄ (C₄A₃$ and 3CaO.SiO₂ (C3S was investigated in this paper. The results indicate that 20 % content of ferrite phase with the composition of C₂A0.5F0.5 can facilitate the coexistence of C₄A₃$ and C₃S solid solutions at 1350 ° C. There are other trace elements that incorporate into clinker minerals and form solid solutions. In addition, the dark and polygonal C₄A₃$ solid solution is not dissolved in liquid phase at 1350 ° C. It can promote the burnability of the raw mixes and provide a favorable condition for the formation of C₃S. However, it has an adverse effect on the coexistence of two clinker minerals with the changing of ferrite compositions. This will provide the important basis for the preparation of the calcium sulphoaluminate cement clinker containing C₃S.

  9. Effects of 45Ca on murine skeletal muscle. 1

    International Nuclear Information System (INIS)

    Asotra, K.; Katoch, S.S.; Krishan, K.; Malhotra, R.K.

    1983-01-01

    Adult Swiss albino mice weighing 16+-1 g were injected with 3.7x10 4 Bq and 7.4x10 4 Bq/g body weight of 45 Ca. Mice of both dose groups were autopsied on days 1, 3, 5, 7, 14 and 28 after 45 Ca administration. Diaphragm and gastrocnemius in the 45 Ca-treated and normal mice were analyzed for quantitation of glycogen as well as bioassay of phosphorylase and phosphohexose isomerase activities. Internal irradiation with the two doses of 45 Ca resulted in glycogen accumulation in both the muscles. 45 Ca-treated diaphragm showed greater radioresponse but a slower recovery than gastrocnemius with respect to glycogen accumulation. A decline in the rates of glycogenolysis and glycolysis indicated by decreased phosphorylase and phosphohexose isomerase activities appeared to be responsible for glycogen accumulation in skeletal muscle on account of 45 Ca treatment. (author)

  10. Observation of microstructure of hydrated Ca3SiO5

    International Nuclear Information System (INIS)

    Mori, Kazuhiro; Sato, Takashi; Fukunaga, Toshiharu; Oishi, Koji; Kimura, Katsuhiko; Iwase, Kenji; Sugiyama, Masaaki; Itoh, Keiji; Shikanai, Fumihito; Wuernisha, Tuerxun; Yonemura, Masao; Sulistyanintyas, Dyah; Tsukushi, Itaru; Takata, Shinich; Otomo, Toshiya; Kamiyma, Takashi; Kawai, Masayoshi

    2006-01-01

    Quasi-elastic neutron scattering experiments were carried out to evaluate the hydration rate of tricalcium silicate (Ca 3 SiO 5 ). Furthermore, in the early hydration period, a variation in surface roughness of Ca 3 SiO 5 was observed in nano-scale by the small-angle neutron scattering. From these results, it was found that the hydration rate of Ca 3 SiO 5 is suppressed when the surface of Ca 3 SiO 5 becomes rough through the creation of hydration products C-S-H gel and Ca(OH) 2 , and this roughness is associated with changes in the Ca 3 SiO 5 hydration rate

  11. Calcium Input Frequency, Duration and Amplitude Differentially Modulate the Relative Activation of Calcineurin and CaMKII

    Science.gov (United States)

    Li, Lu; Stefan, Melanie I.; Le Novère, Nicolas

    2012-01-01

    NMDA receptor dependent long-term potentiation (LTP) and long-term depression (LTD) are two prominent forms of synaptic plasticity, both of which are triggered by post-synaptic calcium elevation. To understand how calcium selectively stimulates two opposing processes, we developed a detailed computational model and performed simulations with different calcium input frequencies, amplitudes, and durations. We show that with a total amount of calcium ions kept constant, high frequencies of calcium pulses stimulate calmodulin more efficiently. Calcium input activates both calcineurin and Ca2+/calmodulin-dependent protein kinase II (CaMKII) at all frequencies, but increased frequencies shift the relative activation from calcineurin to CaMKII. Irrespective of amplitude and duration of the inputs, the total amount of calcium ions injected adjusts the sensitivity of the system to calcium input frequencies. At a given frequency, the quantity of CaMKII activated is proportional to the total amount of calcium. Thus, an input of a small amount of calcium at high frequencies can induce the same activation of CaMKII as a larger amount, at lower frequencies. Finally, the extent of activation of CaMKII signals with high calcium frequency is further controlled by other factors, including the availability of calmodulin, and by the potency of phosphatase inhibitors. PMID:22962589

  12. CaSO4: Dy + Teflon thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Campos, L.L.

    1986-01-01

    A pellet dosemeter of CaSO 4 : Dy + Teflon was developed at IPEN. CaSO 4 : Dy thermoluminescent phosphor, grown in the Dosimetric Materials Production Laboratory was chosen, due to its high sensitivity, ease of preparation and comparatively low cost. Pellets were produced by cold pressing and sintering a mixture of CaSO 4 : Dy and Teflon powders. Extensive work was done to study in detail all CaSO 4 : Dy pellets characteristics from the point of view of dosimetry with the purpose of introducing it in the routine use. A filter combination providing an energy independent response from 20 KeV to 1,25 MeV was obtained. The dosemeter consists of three pellets sealed between two thin plastic sheets and placed under plastic and lead filters. The combination of these tree filters allows the exposure as well as the energy determination of an unknown source. (Author) [pt

  13. Effect of carbonation temperature on CO{sub 2} adsorption capacity of CaO derived from micro/nanostructured aragonite CaCO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hlaing, Nwe Ni, E-mail: nwenihlaing76@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Sreekantan, Srimala, E-mail: srimala@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hinode, Hirofumi, E-mail: hinode@ide.titech.ac.jp; Kurniawan, Winarto, E-mail: Kurniawan.w.ab@m.titech.ac.jp [Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Thant, Aye Aye, E-mail: a2thant@gmail.com [Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Othman, Radzali, E-mail: radzali@utem.edu.my [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Malacca (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@eng.usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Salime, Chris, E-mail: chris.salim@surya.ac.id [Environmental Engineering, Surya University, Tangerang, 15810 Banten (Indonesia)

    2016-07-06

    Recent years, CaO-based synthetic materials have been attracted attention as potential adsorbents for CO{sub 2} capture mainly due to their high CO{sub 2} adsorption capacity. In this study, micro/nanostructured aragonite CaCO{sub 3} was synthesized by a simple hydrothermal method with using polyacrylamide (PAM). The structural, morphological and thermal properties of the synthesized sample were investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and thermogravimetry analysis (TG-DTA). The XRD and FESEM results showed that the obtained sample was aragonite CaCO{sub 3} with aggregated nanorods and microspheres composed of nanorods. A TG-DTA apparatus with Thermoplus 2 software was used to investigate the effect of carbonation temperature on the CO{sub 2} adsorption capacity of CaO derived from aragonite CaCO{sub 3} sample. At 300 °C, the sample reached the CO{sub 2} adsorption capacity of 0.098 g-CO{sub 2}/g-adsorbent, whereas the sample achieved the highest capacity of 0.682 g-CO{sub 2}/g-adsorbent at 700 °C. The results showed that the carbonation temperature significantly influenced on the CO{sub 2} adsorption capacity of the CaO derived from aragonite CaCO{sub 3}.

  14. CA72-4 e CEA no soro e no lavado peritonial de doentes com câncer gástrico CA72-4 and CEA in serum and peritoneal washing in gastric cancer

    Directory of Open Access Journals (Sweden)

    Sandra MANDORWSKI

    2002-03-01

    Full Text Available Racional - O tratamento e o prognóstico dos pacientes com câncer gástrico dependem, principalmente, do estádio clínico. Os marcadores tumorais séricos e do lavado peritonial podem auxiliar a avaliar o risco de recurrência da doença. Casuística e Métodos - Quarenta pacientes com câncer gástrico (11 estádio I ou II e 29 estádio III ou IV e 24 com doença benigna foram estudados prospectivamente. Todos os doentes foram submetidos a laparotomia. O sangue e o lavado peritonial foram colhidos durante o ato cirúrgico, antes da retirada do tumor, para determinação dos marcadores CEA e CA72-4. Resultados - Vinte e cinco por cento e 47,5% dos pacientes com câncer gástrico apresentam elevação dos níveis séricos de CEA e CA72-4. Através das curvas ROC definiram-se os valores de corte dos marcadores no lavado peritonial. Através destas curvas, observaram-se que 60% e 57,5% apresentavam CEA e CA72-4 elevado, respectivamente no grupo com câncer gástrico. Os valores de CEA e CA72-4 foram maiores nos pacientes estádios III e IV. No lavado peritonial, os níveis de CEA foram maiores nos doentes com tumores T3-4. Os valores de CA72-4 no lavado peritonial diferenciaram o grupo controle do grupo com câncer gástrico. Conclusão - O CA72-4 foi o marcador sérico mais sensível no diagnóstico de câncer gástrico. Entretanto, no lavado peritonial, o marcador mais sensível foi o CEA. Os valores de CEA foram superiores nos tumores que ultrapassam a serosa e inferiores nos tumores que se restringem a mucosa e muscular.Background - The treatment and the prognosis of gastric cancer patients depends mainly on clinical stage. Serum and peritoneal tumoral markers levels can be helpful to evaluate individual risk for recurrence. Aims - To evaluate the sensibility of the tumoral markers in the serum and in the peritoneal washing on diagnosis of gastric cancer. Patients and Methods - Forty patients with adenocarcinoma of the stomach (11 stage I or

  15. Dechlorination of hexachlorobenzene using ultrafine Ca-Fe composite oxides

    International Nuclear Information System (INIS)

    Ma Xiaodong; Zheng Minghui; Liu Wenbin; Qian Yong; Zhang Bing; Liu Wenxia

    2005-01-01

    Ca-Fe composite oxides with different Ca/Fe atomic ratios were synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy with elemental X-ray analysis (SEM-EDX) and inductively coupled plasma optical emission spectrometer (ICP-OES). Their dechlorination activities were evaluated using hexachlorobenzene (HCB) as a model compound. The results indicate that the dechlorination activity is related to the composition of metal oxides. Different compositions lead to the formation of different phases of Ca-Fe composite oxides. When Ca/Fe atomic ratio was 3.4, the dechlorination activity reached 97%, which was the highest in the dechlorination of HCB at 300 deg. C for 0.5 h. This may be related to the formation of Ca 2 Fe 2 O 5 phase and small agglomerate size of oxide crystal of about 1 μm. The effect of reaction time on HCB dechlorination and the pathway of dechlorination were investigated using the Ca-Fe composite oxide with the highest activity. It was found that hydrodechlorination took place in the destruction of HCB, the dechlorination efficiency is almost 100% after 2 h reaction. After reaction, quantitative measurement of chloride ion and qualitative analysis of CaCO 3 indicate besides hydrodechlorination, other degradation routes may be present. The mechanism of synergic dechlorination using Ca-Fe composite oxides was discussed

  16. CA V is present in rat kidney mitochondria

    International Nuclear Information System (INIS)

    Dodgson, S.J.; Contino, L.C.

    1987-01-01

    Guinea pig liver mitochondria contain the unique carbonic anhydrase isozyme, CA V. Prior to sacrifice, 15 rats and 15 guinea pigs were either fed normal lab chow (group 1), starved 48 hours (group 2) or fed normal lab chow and given to drink only water with added HCl, pH 2.5 (group 3). Mitochondria were prepared from excised livers and kidneys. CA V activity of disrupted mitochondria was measured by 18 O-mass spectrometric technique at pH 7.4, 37 0 C, 25 mM NaHCO 3 . Mass spectrometric CA assays with intact kidney mitochondria localize CA V activity to the matrix, as was found for liver mitochondria. It has been shown in hepatocytes prepared from starved guinea pigs and rats that inhibition of CA V results in decreased rate of gluconeogenesis from pyruvate. These present results are in line with the published observation that rat kidneys are much more gluconeogenic than guinea pig, and that this is increased by starvation and acidosis

  17. The CaO orange system in meteor spectra

    Science.gov (United States)

    Berezhnoy, A. A.; Borovička, J.; Santos, J.; Rivas-Silva, J. F.; Sandoval, L.; Stolyarov, A. V.; Palma, A.

    2018-02-01

    The CaO orange band system was simulated in the region 5900-6300 Å and compared with the experimentally observed spectra of Benešov bolide wake. The required vibronic Einstein emission coefficients were estimated by means of the experimental radiative lifetimes under the simplest Franck-Condon approximation. A moderate agreement was achieved, and the largest uncertainties come from modeling shape of FeO orange bands. Using a simple model the CaO column density in the wake of the Benešov bolide at the height of 29 km was estimated as (5 ± 2) × 1014 cm-2 by a comparison of the present CaO spectra with the AlO bands nicely observed at 4600-5200 Å in the same spectrum. The obtained CaO content is in a good agreement with the quenching model developed for the impact-produced cloud, although future theoretical and experimental studies of both CaO and FeO orange systems contribution would be needed to confirm these results.

  18. Ca2+ influx and efflux in animal cells in the presence of panax notoginseng extracts: investigated by using 45Ca as a radioactive tracer

    International Nuclear Information System (INIS)

    Yang Yuanyou; Liu Ning; Mo Shangwu; Liao Jiali; Xu Falun

    2010-01-01

    In this paper, the influence of extracts of Panax notoginseng on Ca 2+ influx and efflux in isolated rat visceral organs was investigated by using 45 Ca as a radioactive tracer. The results indicated that both extracts, the total flavonoids and total saponins of Panax notoginseng had significant influence on Ca 2+ influx and efflux in the isolated rat aorta, heart, and kidney, in those organs it could markedly block 45 Ca entering into cell and could facilitate efflux of intracellular Ca 2+ . Compared with the total flavonoids, total saponins had stronger role in the regulation of Ca 2+ influx and efflux. Also, regulation effects of Ca 2+ influx and efflux of the total saponins were compared with positive drug Verapamil, or even better. This implies that the total flavonoids and total saponins of Panax notoginseng have calcium antagonistic effect, and both may be the active ingredients in Panax notoginseng for coronary heart disease treatment. (authors)

  19. Filling the holes in the CaFe4As3 structure: Synthesis and magnetism of CaCo5As3

    Science.gov (United States)

    Rosa, P. F. S.; Scott, B. L.; Ronning, F.; Bauer, E. D.; Thompson, J. D.

    2017-07-01

    Here, we investigate single crystals of CaCo5As3 by means of single-crystal x-ray diffraction, microprobe, magnetic susceptibility, heat capacity, and pressure-dependent transport measurements. CaCo5As3 shares the same structure of CaFe4As3 with an additional Co atom filling a lattice vacancy and undergoes a magnetic transition at TM=16 K associated with a frustrated magnetic order. CaCo5As3 displays metallic behavior and its Sommerfeld coefficient (γ =70 mJ/mol K2) indicates a moderate enhancement of electron-electron correlations. Transport data under pressures to 2.5 GPa reveal a suppression of TM at a rate of -0.008 K/GPa. First-principles electronic structure calculations show a complex three-dimensional band structure and magnetic moments that depend on the local environment at each Co site. Our results are compared with previous data on CaFe4As3 and provide a scenario for a magnetically frustrated ground state in this family of compounds.

  20. YouthCaN 2001 / Sirje Janikson

    Index Scriptorium Estoniae

    Janikson, Sirje

    2001-01-01

    Aprillis 2001 toimus keskkonnateemaline õpilaskonverents YouthCaN 2001 Ameerika Loodusajaloo Muuseumis New Yorkìs. 35 seminarist ühe viis läbi Tartu Noorte Loodusmaja geoloogia ja keskkonnaringi esindus, tutvustati loodusmaja keskkonnaprojekte ja räägiti keskkonnaalaste veebilehtede koostamise kogemustest. YouthCaN (Youth Communicating and Networking) on rahvusvaheline noorte organisatsioon, mis vahendab kogemusi ja uusi ideid elukeskkonnast huvitatud noorte hulgas

  1. BiCaSrCuO superconductors

    International Nuclear Information System (INIS)

    Polvi, V.M.; Niemi, K.J.

    1989-01-01

    BiCaSrCuO and BiPbCaSrCuO powders have been synthesized. Different research methods (SEM,EDS,XRF,SRD,DTA) have been used to characterize the bulk specimen and wires. Resistance and current density measured as a function of temperature are reported. The ceramic products contained several phases. Lead containing specimen gave the best results and the synthesis was easily reproducible

  2. Collective flow in central Ca + Ca and Nb + Nb collisions

    International Nuclear Information System (INIS)

    Fai, G.; Csernai, L.P.; Kapusta, J.I.

    1986-01-01

    Questions related to the entropy, equation of state and collective flow of nuclear matter are important to the authors understanding of high energy nuclear collisions. Completion of the analysis of exclusive measurements on central Ca + Ca and Nb + Nb collisions triggered renewed interest in these problems. In order to address the results of exclusive measurements, however, the complex multifragment final states of high energy nuclear collisions need to be incorporated in a theoretical description. The microcanonical event generator model provides statistically generated complete events that can be compared to the exclusive data on an event-by-event basis. To describe the disassembly of hot nuclear matter the model uses an approximate scheme in which the available final states are populated according to their microcanonical weight in phase space. This statistical description is front-ended with simple geometric ideas to divide the collision system into subsystems and with a prescription to share energy and momentum among the subsystems. Any physical quantity of interest is in principle calculable in the model if sufficient statistics is accumulated

  3. Stochastic simulation of a single inositol 1,4,5-trisphosphate-sensitive Ca2+ channel reveals repetitive openings during 'blip-like' Ca2+ transients.

    Science.gov (United States)

    Swillens, S; Champeil, P; Combettes, L; Dupont, G

    1998-05-01

    Confocal microscope studies with fluorescent dyes of inositol 1,4,5-trisphosphate (InsP3)-induced intracellular Ca2+ mobilization recently established the existence of 'elementary' events, dependent on the activity of individual InsP3-sensitive Ca2+ channels. In the present work, we try by theoretical stochastic simulation to explain the smallest signals observed in those studies, which were referred to as Ca2+ 'blips' [Parker I., Yao Y. Ca2+ transients associated with openings of inositol trisphosphate-gated channels in Xenopus oocytes. J Physiol Lond 1996; 491: 663-668]. For this purpose, we assumed a simple molecular model for the InsP3-sensitive Ca2+ channel and defined a set of parameter values accounting for the results obtained in electrophysiological bilayer experiments [Bezprozvanny I., Watras J., Ehrlich B.E. Bell-shaped calcium-response curves of Ins(1,4,5)P3- and calcium-gated channels from endoplasmic reticulum of cerebellum. Nature 1991; 351: 751-754; Bezprozvanny I., Ehrlich B.E. Inositol (1,4,5)-trisphosphate (InsP3)-gated Ca channels from cerebellum: conduction properties for divalent cations and regulation by intraluminal calcium. J Gen Physiol 1994; 104: 821-856]. With a stochastic procedure which considered cytosolic Ca2+ diffusion explicitly, we then simulated the behaviour of a single channel, placed in a realistic physiological environment. An attractive result was that the simulated channel exhibited bursts of activity, arising from repetitive channel openings, which were responsible for transient rises in Ca2+ concentration and were reminiscent of the relatively long-duration experimental Ca2+ blips. The influence of the values chosen for the various parameters (affinity and diffusion coefficient of the buffers, luminal Ca2+ concentration) on the kinetic characteristics of these theoretical blips is analyzed.

  4. A close association of RyRs with highly dense clusters of Ca2+-activated Cl- channels underlies the activation of STICs by Ca2+ sparks in mouse airway smooth muscle.

    Science.gov (United States)

    Bao, Rongfeng; Lifshitz, Lawrence M; Tuft, Richard A; Bellvé, Karl; Fogarty, Kevin E; ZhuGe, Ronghua

    2008-07-01

    Ca(2+) sparks are highly localized, transient releases of Ca(2+) from sarcoplasmic reticulum through ryanodine receptors (RyRs). In smooth muscle, Ca(2+) sparks trigger spontaneous transient outward currents (STOCs) by opening nearby clusters of large-conductance Ca(2+)-activated K(+) channels, and also gate Ca(2+)-activated Cl(-) (Cl((Ca))) channels to induce spontaneous transient inward currents (STICs). While the molecular mechanisms underlying the activation of STOCs by Ca(2+) sparks is well understood, little information is available on how Ca(2+) sparks activate STICs. In the present study, we investigated the spatial organization of RyRs and Cl((Ca)) channels in spark sites in airway myocytes from mouse. Ca(2+) sparks and STICs were simultaneously recorded, respectively, with high-speed, widefield digital microscopy and whole-cell patch-clamp. An image-based approach was applied to measure the Ca(2+) current underlying a Ca(2+) spark (I(Ca(spark))), with an appropriate correction for endogenous fixed Ca(2+) buffer, which was characterized by flash photolysis of NPEGTA. We found that I(Ca(spark)) rises to a peak in 9 ms and decays with a single exponential with a time constant of 12 ms, suggesting that Ca(2+) sparks result from the nonsimultaneous opening and closure of multiple RyRs. The onset of the STIC lags the onset of the I(Ca(spark)) by less than 3 ms, and its rising phase matches the duration of the I(Ca(spark)). We further determined that Cl((Ca)) channels on average are exposed to a [Ca(2+)] of 2.4 microM or greater during Ca(2+) sparks. The area of the plasma membrane reaching this level is <600 nm in radius, as revealed by the spatiotemporal profile of [Ca(2+)] produced by a reaction-diffusion simulation with measured I(Ca(spark)). Finally we estimated that the number of Cl((Ca)) channels localized in Ca(2+) spark sites could account for all the Cl((Ca)) channels in the entire cell. Taken together these results lead us to propose a model in which

  5. Lowering glucose level elevates [Ca2+]i in hypothalamic arcuate nucleus NPY neurons through P/Q-type Ca2+ channel activation and GSK3β inhibition

    Science.gov (United States)

    Chen, Yu; Zhou, Jun; Xie, Na; Huang, Chao; Zhang, Jun-qi; Hu, Zhuang-li; Ni, Lan; Jin, You; Wang, Fang; Chen, Jian-guo; Long, Li-hong

    2012-01-01

    Aim: To identify the mechanisms underlying the elevation of intracellular Ca2+ level ([Ca2+]i) induced by lowering extracellular glucose in rat hypothalamic arcuate nucleus NPY neurons. Methods: Primary cultures of hypothalamic arcuate nucleus (ARC) neurons were prepared from Sprague-Dawley rats. NPY neurons were identified with immunocytochemical method. [Ca2+]i was measured using fura-2 AM. Ca2+ current was recorded using whole-cell patch clamp recording. AMPK and GSK3β levels were measured using Western blot assay. Results: Lowering glucose level in the medium (from 10 to 1 mmol/L) induced a transient elevation of [Ca2+]i in ARC neurons, but not in hippocampal and cortical neurons. The low-glucose induced elevation of [Ca2+]i in ARC neurons depended on extracellular Ca2+, and was blocked by P/Q-type Ca2+channel blocker ω-agatoxin TK (100 nmol/L), but not by L-type Ca2+ channel blocker nifedipine (10 μmol/L) or N-type Ca2+channel blocker ω-conotoxin GVIA (300 nmol/L). Lowering glucose level increased the peak amplitude of high voltage-activated Ca2+ current in ARC neurons. The low-glucose induced elevation of [Ca2+]i in ARC neurons was blocked by the AMPK inhibitor compound C (20 μmol/L), and enhanced by the GSK3β inhibitor LiCl (10 mmol/L). Moreover, lowering glucose level induced the phosphorylation of AMPK and GSK3β, which was inhibited by compound C (20 μmol/L). Conclusion: Lowering glucose level enhances the activity of P/Q type Ca2+channels and elevates [Ca2+]i level in hypothalamic arcuate nucleus neurons via inhibition of GSK3β. PMID:22504905

  6. Physiological studies in heterozygous calcium sensing receptor (CaSR gene-ablated mice confirm that the CaSR regulates calcitonin release in vivo

    Directory of Open Access Journals (Sweden)

    Kovacs Christopher S

    2004-04-01

    Full Text Available Abstract Background The calcium sensing receptor (CaSR regulates serum calcium by suppressing secretion of parathyroid hormone; it also regulates renal tubular calcium excretion. Inactivating mutations of CaSR raise serum calcium and reduce urine calcium excretion. Thyroid C-cells (which make calcitonin express CaSR and may, therefore, be regulated by it. Since calcium stimulates release of calcitonin, the higher blood calcium caused by inactivation of CaSR should increase serum calcitonin, unless CaSR mutations alter the responsiveness of calcitonin to calcium. To demonstrate regulatory effects of CaSR on calcitonin release, we studied calcitonin responsiveness to calcium in normal and CaSR heterozygous-ablated (Casr+/- mice. Casr+/- mice have hypercalcemia and hypocalciuria, and live normal life spans. Each mouse received either 500 μl of normal saline or one of two doses of elemental calcium (500 μmol/kg or 5 mmol/kg by intraperitoneal injection. Ionized calcium was measured at baseline and 10 minutes, and serum calcitonin was measured on the 10 minute sample. Results At baseline, Casr+/- mice had a higher blood calcium, and in response to the two doses of elemental calcium, had greater increments and peak levels of ionized calcium than their wild type littermates. Despite significantly higher ionized calcium levels, the calcitonin levels of Casr+/- mice were consistently lower than wild type at any ionized calcium level, indicating that the dose-response curve of calcitonin to increases in ionized calcium had been significantly blunted or shifted to the right in Casr+/- mice. Conclusions These results confirm that the CaSR is a physiological regulator of calcitonin; therefore, in response to increases in ionized calcium, the CaSR inhibits parathyroid hormone secretion and stimulates calcitonin secretion.

  7. Comparative Study of Electronic Structure and Magnetic Properties of Osmate Double Perovskites: Ca2FeOsO6 versus Ca2Co(Ni)OsO6

    Science.gov (United States)

    Samanta, Kartik; Saha-Dasgupta, Tanusri

    2018-04-01

    Employing density functional theory, we study the trend in the electronic and magnetic properties of 3d-5d double perovskites, upon varying the 3d element for a fixed choice of 5d element, namely Ca2BOsO6 (B = Fe/Co/Ni). While all three compounds are reported to be ferrimagnets, the magnetic transition temperature of Ca2FeOsO6 is reported to be 2-2.4 times larger than that of Ca2CoOsO6 or Ca2NiOsO6. Our first-principles study provides microscopic insight into this trend. This trend is found to be caused by the downward shift in the position of d level energies of the B site element with respect to that of the Os t2g level upon moving across the 3d series from Fe to Co and Ni. This in turn changes the nominal valence of the Os ion from 5+ in Ca2FeOsO6 to 6+ in Ca2CoOsO6 and Ca2NiOsO6, resulting in differing superexchange paths between Ca2FeOsO6 and Ca2Co(Ni)OsO6, and additionally enabling the hybridization-mechanism-driven magnetism in Ca2FeOsO6. These together significantly enhance the magnetic transition temperature in Ca2FeOsO6 compared with that in Ca2Co(Ni)OsO6.

  8. Effect of CaO addition on preparation of ferrotitanium from ilmenite by electrochemical reduction in CaCl_2−NaCl molten salt

    International Nuclear Information System (INIS)

    Xiong, Li; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Zhang, Qibo; Zhou, Zhongren; Zhang, Yadong; Ru, Juanjian

    2016-01-01

    Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl_2−NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol%CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. - Highlights: • Ferro-titanium was prepared from synthesized ilmenite in CaCl_2−NaCl molten salt. • CaO content has appreciable effect on the phase transformation of ilmenite reactant. • The optimized CaO content is 1 mol% which can significantly improve reaction rate. • The products are connected with each other to form strips as electrolysis time.

  9. NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells

    Science.gov (United States)

    West, William; Whitacre, Jay; DelCastillo, Linda

    2009-01-01

    Experiments and theoretical study have demonstrated the promise of all-solid-state, high-temperature electrochemical battery cells based on NiF2 as the active cathode material, CaF2 doped with NaF as the electrolyte material, and Ca as the active anode material. These and other all-solid-state cells have been investigated in a continuing effort to develop batteries for instruments that must operate in environments much hotter than can be withstood by ordinary commercially available batteries. Batteries of this type are needed for exploration of Venus (where the mean surface temperature is about 450 C), and could be used on Earth for such applications as measuring physical and chemical conditions in geothermal wells and oil wells. All-solid-state high-temperature power cells are sought as alternatives to other high-temperature power cells based, variously, on molten anodes and cathodes or molten eutectic salt electrolytes. Among the all-solid-state predecessors of the present NiF2/NaF:CaF2/Ca cells are those described in "Solid-State High-Temperature Power Cells" (NPO-44396), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 40. In those cells, the active cathode material is FeS2, the electrolyte material is a crystalline solid solution of equimolar amounts of Li3PO4 and LiSiO4, and the active anode material is Li contained within an alloy that remains solid in the intended high operational temperature range.

  10. Nuclear structure of 41Ca from inelastic proton scattering

    International Nuclear Information System (INIS)

    Vold, P.B.; Cline, D.; Voigt, M.J.A. de

    1977-01-01

    Angular distributions have been measured for inelastic and elastic scattering of 19 MeV protons on 40 41 Ca. A total of 89 levels were identified below 6.4 MeV in 41 Ca with an energy resolution of 12 keV. Inelastic transition strengths have been extracted using DWBA theory with a vibrational model form factor. These transition strengths correlate well with inelastic α-scattering and electromagnetic values. The quadrupole strengths are interpreted in terms of the coexistence model and imply that the excited-core admixture in the ground states of both 40 Ca and 41 Ca are approximately 5%. The octupole strengths in 41 Ca exhibits features characteristic of the weak coupling of an fsub(7/2) neutron to the lowest 3 - state in 40 Ca. The l = 5 strength exhibits a similar weak-coupling behavior. In both cases the microscopic structure appreciably reduces the transition strength for the highest spin member of the weak-coupling multiplets. (Auth.)

  11. Ca2+ transport and signalling in enamel cells

    Science.gov (United States)

    Nurbaeva, Meerim K.; Eckstein, Miriam; Feske, Stefan

    2016-01-01

    Abstract Dental enamel is one of the most remarkable examples of matrix‐mediated biomineralization. Enamel crystals form de novo in a rich extracellular environment in a stage‐dependent manner producing complex microstructural patterns that are visually stunning. This process is orchestrated by specialized epithelial cells known as ameloblasts which themselves undergo striking morphological changes, switching function from a secretory role to a cell primarily engaged in ionic transport. Ameloblasts are supported by a host of cell types which combined represent the enamel organ. Fully mineralized enamel is the hardest tissue found in vertebrates owing its properties partly to the unique mixture of ionic species represented and their highly organized assembly in the crystal lattice. Among the main elements found in enamel, Ca2+ is the most abundant ion, yet how ameloblasts modulate Ca2+ dynamics remains poorly known. This review describes previously proposed models for passive and active Ca2+ transport, the intracellular Ca2+ buffering systems expressed in ameloblasts and provides an up‐dated view of current models concerning Ca2+ influx and extrusion mechanisms, where most of the recent advances have been made. We also advance a new model for Ca2+ transport by the enamel organ. PMID:27510811

  12. 45Ca distribution and transport in saponin skinned vascular smooth muscle

    International Nuclear Information System (INIS)

    Stout, M.A.; Diecke, F.P.

    1983-01-01

    45 Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Ca sequestering system. 45 Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. 45 Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The 45 Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning

  13. Probing the internal calcification chemistry of O. universa using B/Ca

    Science.gov (United States)

    Holland, K.; Eggins, S.; Hoenisch, B.; Haynes, L.; Russell, A. D.

    2014-12-01

    The B/Ca, U/Ca ratio values of calcitic foraminifer shells are all influenced by seawater carbonate chemistry (seawater [B(OH)4-/HCO3-], [CO32-], and pH respectively), and as such are increasingly being used as proxies to reconstruct past changes in ocean inorganic carbon content, saturation state and pH. However, the behavior of these proxies is subject to modification by foraminifers' efforts to regulate the conditions under which they grow their shells. We have undertaken experiments on Orbulina universa that manipulate synthetic culture water DIC, pH and [Ca] in an effort to disentangle the biological versus environmental influences of seawater carbonate system and saturation state on B/Ca, U/Ca and Mg/Ca ratio into foraminiferal calcite. Experiments were designed to be able determine the extent to which foraminifers are able to modify the chemical composition of their (vacuolized?) internal calcification fluid, in particular by using B/Ca and U/Ca as sensors for calcification chemistry (i.e. internal [B(OH)4-/HCO3-] and [CO32-]) . We have used a high resolution LA-ICPMS depth profiling techniques to characterize the amplitude of B/Ca, U/Ca, Mg/Ca, and Sr/Ca ratio values across and the thickness (calcification rate) of diurnal bands that are developed in individual shells grown under different synthetic seawater compositions. Results indicate Orbulina universa modify the chemistry of their calcification fluid far from that of external seawater, but are not able to mitigate changes in external seawater. This most likely achieved through the interactive effects of internal pH manipulation and a carbon concentration mechanism. Our results are likely to have important implications for the interpretation of Mg/Ca, B/Ca and U/Ca as proxies seawater temperatures and carbonate system parameters.

  14. Calcium in pollen-pistil interaction in `Petunia hybrida Hat`. Pt. 3. Localization of Ca{sup 2+} ions and Ca{sup 2+}-ATPase in pollinated pistil

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, E.; Butowt, R. [Uniwersytet Mikolaja Kopernika, Torun (Poland)

    1995-12-31

    Studies were carried out of Ca{sup 2+} and Ca{sup 2+}-ATPase localization in pollinated (6 and 48 h after pollination) pistils of `Petunia hybrida`. The results were confronted with Ca{sup 2+} localization in mature pollen grain and in unpollinated pistil. It has been found that after pollination the number of Ca{sup 2+} sequestered in the stigmal exudate and in the sporoderm of the pollen grain gets lower. That phenomenon was associated with the appearance of a large number of Sb/Ca precipitates in the submembrane cytoplasm of the germinating pollen. In the vacuolized pollen grain, i.e. grown into a pollen tube, there were only a few precipitates. In the pollen tube, Ca{sup 2+} were found in the organelles of the tip cytoplasm and in the external pectin cell wall. Studies with the use of {sup 45}Ca{sup 2+} have revealed that the source of calcium ions incorporated into the pollen tube tip and its pectin wall is the transmitting tract of the style. In the transmitting tract overgrown with pollen tubes, Ca{sup 2+} were localized in the intercellular matrix and in the transmitting cell. Sb/Ca precipitates occurred in the nuclei, around the secretary vesicles and on the plasmalemma in the transverse walls region. Elevated Ca{sup 2+} level was found in degenerating cells (inhibited pollen tubes, transmitting cells, nucellar cells). The progressing degeneration process of the cells of the transmitting tract of the pollinated pistil was associated with a decrease in the activity of plasmalemma Ca{sup 2+}-ATPase. (author). 30 refs, 19 figs.

  15. Engineering Synthetic Proteins to Generate Ca2+ Signals in Mammalian Cells.

    Science.gov (United States)

    Qudrat, Anam; Truong, Kevin

    2017-03-17

    The versatility of Ca 2+ signals allows it to regulate diverse cellular processes such as migration, apoptosis, motility and exocytosis. In some receptors (e.g., VEGFR2), Ca 2+ signals are generated upon binding their ligand(s) (e.g., VEGF-A). Here, we employed a design strategy to engineer proteins that generate a Ca 2+ signal upon binding various extracellular stimuli by creating fusions of protein domains that oligomerize to the transmembrane domain and the cytoplasmic tail of the VEGFR2. To test the strategy, we created chimeric proteins that generate Ca 2+ signals upon stimulation with various extracellular stimuli (e.g., rapamycin, EDTA or extracellular free Ca 2+ ). By coupling these chimeric proteins that generate Ca 2+ signals with proteins that respond to Ca 2+ signals, we rewired, for example, dynamic cellular blebbing to increases in extracellular free Ca 2+ . Thus, using this design strategy, it is possible to engineer proteins to generate a Ca 2+ signal to rewire a wide range of extracellular stimuli to a wide range of Ca 2+ -activated processes.

  16. Electric giant resonances in sup 4 sup 0 Ca and sup 4 sup 8 Ca probed with electron and proton scattering coincidence experiments

    CERN Document Server

    Strauch, S

    1999-01-01

    Excitation and particle decay of electric giant resonances in sup 4 sup 0 Ca and sup 4 sup 8 Ca are studied with electron and proton beams. Recent results of a sup 4 sup 8 Ca(e,e'n) measurement performed at the S-DALINAC in Darmstadt with kinematics that selectively populate electric monopole, dipole and quadrupole excitations are presented. The extracted B(E1) strength distribution is in good agreement with photo nuclear data and the predictions of microscopic calculations. The summed B(E2+E0) strength distribution, however disagrees with the result of these calculations. The neutron emission of the giant dipole resonance in sup 4 sup 8 Ca shows a large fraction of direct decay to sup 4 sup 7 Ca hole states. In addition, isoscalar giant monopole resonance strength in sup 4 sup 0 Ca was extracted from (e,e'alpha sub 0) and (e,e'alpha sub 1) angular correlations. A study of the quadrupole strength in the alpha sub 0 decay channel of sup 4 sup 0 Ca with a (p,p'alpha) coincidence measurement reiterates the unsol...

  17. Ca2+-induced uncoupling of Aplysia bag cell neurons.

    Science.gov (United States)

    Dargaei, Zahra; Standage, Dominic; Groten, Christopher J; Blohm, Gunnar; Magoski, Neil S

    2015-02-01

    Electrical transmission is a dynamically regulated form of communication and key to synchronizing neuronal activity. The bag cell neurons of Aplysia are a group of electrically coupled neuroendocrine cells that initiate ovulation by secreting egg-laying hormone during a prolonged period of synchronous firing called the afterdischarge. Accompanying the afterdischarge is an increase in intracellular Ca2+ and the activation of protein kinase C (PKC). We used whole cell recording from paired cultured bag cell neurons to demonstrate that electrical coupling is regulated by both Ca2+ and PKC. Elevating Ca2+ with a train of voltage steps, mimicking the onset of the afterdischarge, decreased junctional current for up to 30 min. Inhibition was most effective when Ca2+ entry occurred in both neurons. Depletion of Ca2+ from the mitochondria, but not the endoplasmic reticulum, also attenuated the electrical synapse. Buffering Ca2+ with high intracellular EGTA or inhibiting calmodulin kinase prevented uncoupling. Furthermore, activating PKC produced a small but clear decrease in junctional current, while triggering both Ca2+ influx and PKC inhibited the electrical synapse to a greater extent than Ca2+ alone. Finally, the amplitude and time course of the postsynaptic electrotonic response were attenuated after Ca2+ influx. A mathematical model of electrically connected neurons showed that excessive coupling reduced recruitment of the cells to fire, whereas less coupling led to spiking of essentially all neurons. Thus a decrease in electrical synapses could promote the afterdischarge by ensuring prompt recovery of electrotonic potentials or making the neurons more responsive to current spreading through the network. Copyright © 2015 the American Physiological Society.

  18. CaMKII Requirement for in Vivo Insular Cortex LTP Maintenance and CTA Memory Persistence

    Directory of Open Access Journals (Sweden)

    Yectivani Juárez-Muñoz

    2017-11-01

    Full Text Available Calcium-calmodulin/dependent protein kinase II (CaMKII plays an essential role in LTP induction, but since it has the capacity to remain persistently activated even after the decay of external stimuli it has been proposed that it can also be necessary for LTP maintenance and therefore for memory persistence. It has been shown that basolateral amygdaloid nucleus (Bla stimulation induces long-term potentiation (LTP in the insular cortex (IC, a neocortical region implicated in the acquisition and retention of conditioned taste aversion (CTA. Our previous studies have demonstrated that induction of LTP in the Bla-IC pathway before CTA training increased the retention of this task. Although it is known that IC-LTP induction and CTA consolidation share similar molecular mechanisms, little is known about the molecular actors that underlie their maintenance. The purpose of the present study was to evaluate the role of CaMKII in the maintenance of in vivo Bla-IC LTP as well as in the persistence of CTA long-term memory (LTM. Our results show that acute microinfusion of myr-CaMKIINtide, a selective inhibitor of CaMKII, in the IC of adult rats during the late-phase of in vivo Bla-IC LTP blocked its maintenance. Moreover, the intracortical inhibition of CaMKII 24 h after CTA acquisition impairs CTA-LTM persistence. Together these results indicate that CaMKII is a central key component for the maintenance of neocortical synaptic plasticity as well as for persistence of CTA-LTM.

  19. Intracellular [Ca2+] and Vo2 after manipulation of the free-energy of the Na+/Ca(2+)-exchanger in isolated rat ventricular myocytes

    NARCIS (Netherlands)

    Fiolet, J. W.; Baartscheer, A.; Schumacher, C. A.

    1995-01-01

    We have investigated whether the Na+/Ca(2+)-exchanger has a functional regulatory role in the control of oxidative metabolism in suspensions of isolated rat ventricular myocytes. Therefore we simultaneously measured intracellular [Ca2+] ([Ca2+]i) with Indo-1 and respiratory rate (Vo2) after abrupt

  20. Study on the diagnostic values of changes of serum endometrium antibody (EMAb) and CA125 (CA125) levels in patients with endometriosis

    International Nuclear Information System (INIS)

    Yang Jingxiu; Shi Shaohong; Wang Yuping

    2005-01-01

    Objective: To explore the diagnostic values of changes of serum EMAb and CA125 levels in patients with endometriosis. Methods: Serum EMAb levels were measured with ELISA and CA125 levels with RIA in 54 patients with endometriosis and 35 controls. Results: Positive rate of serum EMAb was significantly higher in the patients with endometriosis than those in controls (P≤0.01). Serum CA125 levels were also significantly higher than those in controls (P<0.01). Conclusion: Combined detection of serum EMAb positive rate and CA125 levels was of diagnostic value in patients with endometriosis. (authors)

  1. Store-operated Ca2+ Entry Modulates the Expression of Enamel Genes.

    Science.gov (United States)

    Nurbaeva, M K; Eckstein, M; Snead, M L; Feske, S; Lacruz, R S

    2015-10-01

    Dental enamel formation is an intricate process tightly regulated by ameloblast cells. The correct spatiotemporal patterning of enamel matrix protein (EMP) expression is fundamental to orchestrate the formation of enamel crystals, which depend on a robust supply of Ca2+. In the extracellular milieu, Ca2+ -EMP interactions occur at different levels. Despite its recognized role in enamel development, the molecular machinery involved in Ca2+ homeostasis in ameloblasts remains poorly understood. A common mechanism for Ca2+ influx is store-operated Ca2+ entry (SOCE). We evaluated the possibility that Ca2+ influx in enamel cells might be mediated by SOCE and the Ca2+ release-activated Ca2+ (CRAC) channel, the prototypical SOCE channel. Using ameloblast-like LS8 cells, we demonstrate that these cells express Ca2+ -handling molecules and mediate Ca2+ influx through SOCE. As a rise in the cytosolic Ca2+ concentration is a versatile signal that can modulate gene expression, we assessed whether SOCE in enamel cells had any effect on the expression of EMPs. Our results demonstrate that stimulating LS8 cells or murine primary enamel organ cells with thapsigargin to activate SOCE leads to increased expression of Amelx, Ambn, Enam, Mmp20. This effect is reversed when cells are treated with a CRAC channel inhibitor. These data indicate that Ca2+ influx in LS8 cells and enamel organ cells is mediated by CRAC channels and that Ca2+ signals enhance the expression of EMPs. Ca2+ plays an important role not only in mineralizing dental enamel but also in regulating the expression of EMPs. © International & American Associations for Dental Research 2015.

  2. A process analysis of the CA3 subregion of the hippocampus

    Directory of Open Access Journals (Sweden)

    Raymond PIERRE Kesner

    2013-05-01

    Full Text Available AbstractFrom a behavioral perspective the CA3a,b subregion of the hippocampus plays an important role in the encoding of new spatial information within short-term memory with a duration of seconds and minutes. This can easily be observed in tasks that require rapid encoding, novelty detection, 1-trial short- term or working memory, and 1-trial cued recall primarily for spatial information. These are tasks that have been assumed to reflect the operations of episodic memory and require interactions between CA3a,b and the dentate gyrus via mossy fiber inputs into the CA3a,b. The CA3a,b is also important for encoding of spatial information requiring the acquisition of arbitrary and relational associations. All these tasks are assumed to operate within an autoassociative network function of the CA3 region. The CA3a,b also supports retrieval of short-term memory information based on a spatial pattern completion process. Based on afferent inputs into CA3a,b from the dentate gyrus (DG via mossy fibers and afferents from the entorhinal cortex into CA3a,b as well as reciprocal connections with the septum, CA3a,b can bias the process of encoding utilizing the operation of spatial pattern separation and the process of retrieval utilizing the operation of pattern completion. The CA3a,b also supports sequential processing of information in cooperation with CA1 based on the Schaffer collateral output from CA3a,b to CA1. The CA3c function is in part based on modulation of the DG in supporting pattern separation processes.

  3. Lattice Dynamics of fcc Ca

    DEFF Research Database (Denmark)

    Stassis, C.; Zaretsky, J.; Misemer, D. K.;

    1983-01-01

    A large single crystal of FCC Ca was grown and was used to study the lattice dynamics of this divalent metal by coherent inelastic neutron scattering. The phonon dispersion curves were measured, at room temperature, along the [ξ00], [ξξ0], [ξξξ], and [0ξ1] symmetry directions. The dispersion curves...... to the propagation of elastic waves. The frequencies of the T1[ξξ0] branch for ξ between approximately 0.5 and 0.8 are slightly above the velocity-of-sound line determined from the low-frequency measurements. Since a similar effect has been observed in FCC Yb, it is natural to assume that the anomalous dispersion...... bear a striking resemblance to those of FCC Yb, which is also a divalent metal with an electronic band structure similar to that of Ca. In particular, the shear moduli c44 and (c11-c 12)/2 differ by a factor of 3.4, which implies that FCC Ca (like FCC Yb) is very anisotropic with regard...

  4. Trace Element Partitioning Between low-Ca Pyroxene and Ultracalcic Liquids.

    Science.gov (United States)

    Pertermann, M.; Schmidt, M. W.; Pettke, T.

    2003-12-01

    Low-Ca pyroxene or pigeonite ( ˜0.25-0.35 Ca per formula unit, pfu) is an important residual phase during high temperature melting of refractory mantle (e.g., ankaramite formation). High-Ca cpx (>0.6-0.7 Ca pfu) may be residual to relatively low temperature melting of fertile mantle (MOR and OI), but the opx-cpx solvus narrows considerably at higher temperatures (>1330-1350° C), leading to coexisting opx and low-Ca cpx. Little is known about the trace element partitioning of such low-Ca cpx at upper mantle conditions. Our new partitioning experiments investigate the role of low-Ca cpx during melting of depleted peridotite. Nominally anhydrous experiments with graphite-lined Pt-capsules were conducted at 1.4 GPa and 1360-1370° C. The synthetic starting material is close in composition to an ultracalcic liquid saturated in opx+pigeonite+olivine+spinel. The experiments yielded assemblages of glass, low-Ca cpx, ol, and minor Cr-spinel; opx is absent. The low-Ca clinopyroxenes have 0.20 and 0.32 Ca pfu at 1370 and 1360° C, respectively, and tetrahedral Al of 0.046 and 0.067 pfu. The liquids have ˜50 wt% SiO2, ˜12.5 wt% CaO and CaO/Al2O3 of 1.44-1.54. Pyroxenes and glasses were analyzed for trace elements (La, Ce, Nd, Sm, Eu, Gd, Dy, Er Yb, Lu, Sc, Y, Sr, Zr, Hf, V, Cr, Mn, Co, Zn) by LA-ICP-MS using a 193 nm ArF excimer laser coupled to an Elan 6100 mass spectrometer. Ablation occurred in He, and ablation spot sizes were 15-30 μ m for minerals and 50 μ m for glasses. Trace element concentrations in pyroxenes were low for most 3+ and 4+ cations. This resulted in small mineral/melt partition coefficients (D-values), approximately an order of magnitude lower than those for high-Ca cpx associated with peridotite melting, thus making the low-Ca cpx partitioning behavior rather similar to the behavior of peridotitic opx. Cpx with 0.32 Ca pfu has slightly elevated D-values for 3+ cations when compared to the 0.20 Ca pfu cpx: DSc = 0.45, DY = 0.11, DSm = 0.054 and DYb

  5. Effect of total pressure on sulfur capture of Ca-ion exchanged coal; Kaatsu jokenka ni okeru Ca-tanjitan no datsuryu koka

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S.; Benjamin, G.; Abe, H.; Harano, A.; Takarada, T. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    In relation to coal gasification and combustion under high pressure as highly efficient coal utilization, the effect of total pressure and sintering on the SO2 capture ability of Ca-ion exchanged coal and other desulfurizing agents were studied. In experiment, specimens were filled into a small pressurized reactor to heat them under high-pressure N2 atmosphere. After the completion of combustion reaction of char at 850{degree}C, SO2, CO2 and CO gases were measured at an outlet while flowing SO2/N2. As the experimental result, all of the S content in Ca-ion exchanged coal was not absorbed by Ca content in coal during pyrolysis and combustion, resulting in discharge of 36% of the S content. Since Ca-ion exchanged coal is fast in combustion reaction, most of the S content was desulfurized by coal ash. The ash content yielded from Ca-ion exchanged coal was more excellent in SO2 capture ability than limestone even under higher pressure. In the case of CO2 partial pressure lower than equilibrium CO2 pressure for CaCO3 decomposition, the capture ability decreased with an increase in total pressure, while in higher CO2 partial pressure, it was improved. 1 ref., 7 figs., 2 tabs.

  6. Revising the Subsystem Nurse’s A-Phase-Silicocarnotite within the System Ca3(PO42–Ca2SiO4

    Directory of Open Access Journals (Sweden)

    Patricia Ros-Tárraga

    2016-04-01

    Full Text Available The subsystem Nurse’s A-phase-silicocarnotite within the system Ca3(PO42–Ca2SiO4 was conducted as a preliminary step toward obtaining new biomaterials with controlled microstructures. Phase composition of the resulting ceramics was studied by X-ray diffraction, differential thermal analysis, and scanning electron microscopy with attached wavelength dispersive spectroscopy. The results showed that the sub-system presents an invariant eutectoid point at 1366 ± 4 °C with a composition of 59.5 wt % Ca3(PO42 and 40.5 wt % Ca2SiO4, and typical eutectoid microstructure of lamellae morphology. These results are in disagreement with the previous reported data, which locate the invariant eutectoid point at 1250 ± 20 °C with a composition of 55 wt % Ca3(PO42 and 45 wt % Ca2SiO4. In addition, cell attachment testing showed that the new eutectoid material supported the mesenchymal stem cell adhesion and spreading, and the cells established close contact with the ceramic after 28 days of culture. These findings indicate that the new ceramic material with eutectoid microstructure of lamellae morphology possesses good bioactivity and biocompatibility and might be a promising bone implant material.

  7. Development of novel antibacterial active, HaCaT biocompatible and biodegradable CA-g-P(3HB-EC biocomposites with caffeic acid as a functional entity

    Directory of Open Access Journals (Sweden)

    H. M. N. Iqbal

    2015-09-01

    Full Text Available We have developed novel composites by grafting caffeic acid (CA onto the P(3HB-EC based material and laccase from Trametes versicolor was used for grafting purposes. The resulting composites were designated as CA-g-P(3HB-EC i.e., P(3HB-EC (control, 5CA-g-P(3HB-EC, 10CA-g-P(3HB-EC, 15CA-g-P(3HB-EC and 20CA-g-P(3HB-EC. FT-IR (Fourier-transform infrared spectroscopy was used to examine the functional and elemental groups of the control and laccase-assisted graft composites. Evidently, 15CA-g-P(3HB-EC composite exhibited resilient antibacterial activity against Gram-positive and Gram-negative bacterial strains. Moreover, a significant level of biocompatibility and biodegradability of the CA-g-P(3HB-EC composites was also achieved with the human keratinocytes-like HaCaT cells and soil burial evaluation, respectively. In conclusion, the newly developed novel composites with multi characteristics could well represent the new wave of biomaterials for medical applications, and more specifically have promising future in the infection free would dressings, burn and/or skin regeneration field due to their sophisticated characteristics.

  8. Ursodeoxycholic and deoxycholic acids: Differential effects on intestinal Ca(2+) uptake, apoptosis and autophagy of rat intestine.

    Science.gov (United States)

    Rodríguez, Valeria A; Rivoira, María A; Pérez, Adriana del V; Marchionatti, Ana M; Tolosa de Talamoni, Nori G

    2016-02-01

    The aim of this work was to study the effect of sodium deoxycholate (NaDOC) and ursodeoxycholic acid (UDCA) on Ca(2+) uptake by enterocytes and the underlying mechanisms. Rats were divided into four groups: a) controls, b) treated with NaDOC, c) treated with UDCA d) treated with NaDOC and UDCA. Ca(2+) uptake was studied in enterocytes with different degrees of maturation. Apoptosis, autophagy and NO content and iNOS protein expression were evaluated. NaDOC decreased and UDCA increased Ca(2+) uptake only in mature enterocytes. The enhancement of protein expression of Fas, FasL, caspase-8 and caspase-3 activity by NaDOC indicates triggering of the apoptotic extrinsic pathway, which was blocked by UDCA. NO content and iNOS protein expression were enhanced by NaDOC, and avoided by UDCA. The increment of acidic vesicular organelles and LC3 II produced by NaDOC was also prevented by UDCA. In conclusion, the inhibitory effects of NaDOC on intestinal Ca(2+) absorption occur by decreasing the Ca(2+) uptake by mature enterocytes. NaDOC triggers apoptosis and autophagy, in part as a result of nitrosative stress. In contrast, UDCA increases the Ca(2+) uptake by mature enterocytes, and in combination with NaDOC acts as an antiapoptotic and antiautophagic agent normalizing the transcellular Ca(2+) pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Simulating Urban Growth Using a Random Forest-Cellular Automata (RF-CA Model

    Directory of Open Access Journals (Sweden)

    Courage Kamusoko

    2015-04-01

    Full Text Available Sustainable urban planning and management require reliable land change models, which can be used to improve decision making. The objective of this study was to test a random forest-cellular automata (RF-CA model, which combines random forest (RF and cellular automata (CA models. The Kappa simulation (KSimulation, figure of merit, and components of agreement and disagreement statistics were used to validate the RF-CA model. Furthermore, the RF-CA model was compared with support vector machine cellular automata (SVM-CA and logistic regression cellular automata (LR-CA models. Results show that the RF-CA model outperformed the SVM-CA and LR-CA models. The RF-CA model had a Kappa simulation (KSimulation accuracy of 0.51 (with a figure of merit statistic of 47%, while SVM-CA and LR-CA models had a KSimulation accuracy of 0.39 and −0.22 (with figure of merit statistics of 39% and 6%, respectively. Generally, the RF-CA model was relatively accurate at allocating “non-built-up to built-up” changes as reflected by the correct “non-built-up to built-up” components of agreement of 15%. The performance of the RF-CA model was attributed to the relatively accurate RF transition potential maps. Therefore, this study highlights the potential of the RF-CA model for simulating urban growth.

  10. Targeting Cardiomyocyte Ca2+ Homeostasis in Heart Failure

    Science.gov (United States)

    Røe, Åsmund T.; Frisk, Michael; Louch, William E.

    2015-01-01

    Improved treatments for heart failure patients will require the development of novel therapeutic strategies that target basal disease mechanisms. Disrupted cardiomyocyte Ca2+ homeostasis is recognized as a major contributor to the heart failure phenotype, as it plays a key role in systolic and diastolic dysfunction, arrhythmogenesis, and hypertrophy and apoptosis signaling. In this review, we outline existing knowledge of the involvement of Ca2+ homeostasis in these deficits, and identify four promising targets for therapeutic intervention: the sarcoplasmic reticulum Ca2+ ATPase, the Na+-Ca2+ exchanger, the ryanodine receptor, and t-tubule structure. We discuss experimental data indicating the applicability of these targets that has led to recent and ongoing clinical trials, and suggest future therapeutic approaches. PMID:25483944

  11. PDGF-induced migration of synthetic vascular smooth muscle cells through c-Src-activated L-type Ca2+ channels with full-length CaV1.2 C-terminus.

    Science.gov (United States)

    Guo, Xiaoguang; Kashihara, Toshihide; Nakada, Tsutomu; Aoyama, Toshifumi; Yamada, Mitsuhiko

    2018-06-01

    In atherosclerosis, vascular smooth muscle cells (VSMC) migrate from the media toward the intima of the arteries in response to cytokines, such as platelet-derived growth factor (PDGF). However, molecular mechanism underlying the PDGF-induced migration of VSMCs remains unclear. The migration of rat aorta-derived synthetic VSMCs, A7r5, in response to PDGF was potently inhibited by a Ca V 1.2 channel inhibitor, nifedipine, and a Src family tyrosine kinase (SFK)/Abl inhibitor, bosutinib, in a less-than-additive manner. PDGF significantly increased Ca V 1.2 channel currents without altering Ca V 1.2 protein expression levels in A7r5 cells. This reaction was inhibited by C-terminal Src kinase, a selective inhibitor of SFKs. In contractile VSMCs, the C-terminus of Ca V 1.2 is proteolytically cleaved into proximal and distal C-termini (PCT and DCT, respectively). Clipped DCT is noncovalently reassociated with PCT to autoinhibit the channel activity. Conversely, in synthetic A7r5 cells, full-length Ca V 1.2 (Ca V 1.2FL) is expressed much more abundantly than truncated Ca V 1.2. In a heterologous expression system, c-Src activated Ca V 1.2 channels composed of Ca V 1.2FL but not truncated Ca V 1.2 (Ca V 1.2Δ1763) or Ca V 1.2Δ1763 plus clipped DCT. Further, c-Src enhanced the coupling efficiency between the voltage-sensing domain and activation gate of Ca V 1.2FL channels by phosphorylating Tyr1709 and Tyr1758 in PCT. Compared with Ca V 1.2Δ1763, c-Src could more efficiently bind to and phosphorylate Ca V 1.2FL irrespective of the presence or absence of clipped DCT. Therefore, in atherosclerotic lesions, phenotypic switching of VSMCs may facilitate pro-migratory effects of PDGF on VSMCs by suppressing posttranslational Ca V 1.2 modifications.

  12. Thermoluminescence properties of CaO powder obtained from chicken eggshells

    Science.gov (United States)

    Nagabhushana, K. R.; Lokesha, H. S.; Satyanarayana Reddy, S.; Prakash, D.; Veerabhadraswamy, M.; Bhagyalakshmi, H.; Jayaramaiah, J. R.

    2017-09-01

    Eggshell wastage has created serious problem in disposal of the food processing industry which has been triggered the thoughts of researchers to use wasted eggshells as good source of calcium. In the present work, calcium oxide (CaO) has been synthesized by combustion process in furnace (F-CaO) and microwave oven (M-CaO) using the source of chicken eggshells. The obtained F-CaO and M-CaO are characterized by XRD, SEM with EDX and thermoluminescence (TL) technique. XRD pattern of both the samples show cubic phase with crystallite size 45-52 nm. TL glow curves are recorded for various gamma radiation dose (300-4000 Gy). Two TL glows, a small peak at 424 K and stronger peak at 597 K are observed. TL response of M-CaO is 2.67 times higher than F-CaO sample. TL kinetic parameters are calculated by computerized curve deconvolution analysis (CCDA) and discussed.

  13. Compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O on the strength of steel slag: cement binding materials

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Liqian; Liu, Jiaxiang; Liu, Qian, E-mail: ljxpost@263.net [Beijing Key Laboratory of Electrochemical Process and Technology for Materials, The State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing (China)

    2016-03-15

    In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were added. This was done to study the compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO{sub 3} could accelerate the hydration of C{sub 3}S. In addition, CaCO{sub 3} was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO{sub 4}·2H{sub 2}O could increase the number of AFt. The compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior. (author)

  14. Reverse mode Na+/Ca2+ exchange mediated by STIM1 contributes to Ca2+ influx in airway smooth muscle following agonist stimulation

    Directory of Open Access Journals (Sweden)

    Fox Jane

    2010-12-01

    Full Text Available Abstract Background Agonist stimulation of airway smooth muscle (ASM results in IP3 mediated Ca2+ release from the sarcoplasmic reticulum followed by the activation of store operated and receptor operated non-selective cation channels. Activation of these non-selective channels also results in a Na+ influx. This localised increase in Na+ levels can potentially switch the Na+/Ca2+ exchanger into reverse mode and so result in a further influx of Ca2+. The aim of this study was to characterise the expression and physiological function of the Na+/Ca2+ exchanger in cultured human bronchial smooth muscle cells and determine its contribution to agonist induced Ca2+ influx into these cells. Methods The expression profile of NCX (which encodes the Na+/Ca2+ exchanger homologues in cultured human bronchial smooth muscle cells was determined by reverse transcriptase PCR. The functional activity of reverse mode NCX was investigated using a combination of whole cell patch clamp, intracellular Ca2+ measurements and porcine airway contractile analyses. KB-R7943 (an antagonist for reverse mode NCX and target specific siRNA were utilised as tools to inhibit NCX function. Results NCX1 protein was detected in cultured human bronchial smooth muscle cells (HBSMC cells and NCX1.3 was the only mRNA transcript variant detected. A combination of intracellular Na+ loading and addition of extracellular Ca2+ induced an outwardly rectifying current which was augmented following stimulation with histamine. This outwardly rectifying current was inhibited by 10 μM KB-R7943 (an antagonist of reverse mode NCX1 and was reduced in cells incubated with siRNA against NCX1. Interestingly, this outwardly rectifying current was also inhibited following knockdown of STIM1, suggesting for the first time a link between store operated cation entry and NCX1 activation. In addition, 10 μM KB-R7943 inhibited agonist induced changes in cytosolic Ca2+ and induced relaxation of porcine

  15. Density functional study of CaN monolayer on Si(001)

    Energy Technology Data Exchange (ETDEWEB)

    Saati asr, Maryam; Zahedifar, Maedeh; Hashemifar, S. Javad; Akbarzadeh, Hadi

    2016-01-01

    In this work, the first-principles computations are performed to study the structural and magnetic properties of CaN/Si(001) interface. Bulk CaN in the zinc-blende (ZB) structure is argued to be an ionic magnetic compound with a total spin moment of 1 μ{sub B} per formula unit, originated from the p electrons of N ions. Various interface configurations of a ZB CaN monolayer on Si (001) surface are investigated and the lowest energy and the highest spin polarized interfaces are extracted. Then the minimum energy path between the lowest energy and the highest spin polarized interfaces are calculated by using the nudged elastic band method and it is argued that both these systems are unstable toward a nonmagnetic interface with a rock–salt arrangement of Ca and N atoms. - Highlights: • Ab-initio studies are done on various structures of CaN monolayer on Si (001). • The lowest energy system was found to be the N-top configuration interface, while the highest spin polarization was observed in the Ca-hollow termination. • Both Ca-hollow and N-top are unstable toward a nonmagnetic rock–salt CaN monolayer on silicon surface. • Realization of a magnetic CaN/Si (001) interface likely requires some buffer layer on silicon surface, prior to the thin film deposition.

  16. Density functional study of CaN monolayer on Si(001)

    International Nuclear Information System (INIS)

    Saati asr, Maryam; Zahedifar, Maedeh; Hashemifar, S. Javad; Akbarzadeh, Hadi

    2016-01-01

    In this work, the first-principles computations are performed to study the structural and magnetic properties of CaN/Si(001) interface. Bulk CaN in the zinc-blende (ZB) structure is argued to be an ionic magnetic compound with a total spin moment of 1 μ_B per formula unit, originated from the p electrons of N ions. Various interface configurations of a ZB CaN monolayer on Si (001) surface are investigated and the lowest energy and the highest spin polarized interfaces are extracted. Then the minimum energy path between the lowest energy and the highest spin polarized interfaces are calculated by using the nudged elastic band method and it is argued that both these systems are unstable toward a nonmagnetic interface with a rock–salt arrangement of Ca and N atoms. - Highlights: • Ab-initio studies are done on various structures of CaN monolayer on Si (001). • The lowest energy system was found to be the N-top configuration interface, while the highest spin polarization was observed in the Ca-hollow termination. • Both Ca-hollow and N-top are unstable toward a nonmagnetic rock–salt CaN monolayer on silicon surface. • Realization of a magnetic CaN/Si (001) interface likely requires some buffer layer on silicon surface, prior to the thin film deposition.

  17. CaCO3-III and CaCO3-VI, high-pressure polymorphs of calcite: Possible host structures for carbon in the Earth's mantle

    Science.gov (United States)

    Merlini, M.; Hanfland, M.; Crichton, W. A.

    2012-06-01

    Calcite, CaCO3, undergoes several high pressure phase transitions. We report here the crystal structure determination of the CaCO3-III and CaCO3-VI high-pressure polymorphs obtained by single-crystal synchrotron X-ray diffraction. This new technical development at synchrotron beamlines currently affords the possibility of collecting single-crystal data suitable for structure determination in-situ at non-ambient conditions, even after multiphase transitions. CaCO3-III, observed in the pressure range 2.5-15 GPa, is triclinic, and it presents two closely related structural modifications, one, CaCO3-III, with 50 atoms in the unit cell [a=6.281(1) Å, b=7.507(2) Å, c=12.516(3) Å, α=93.76(2)°, β=98.95(2)°, γ=106.49(2)°, V=555.26(20) Å3 at 2.8 GPa], the second, CaCO3-IIIb, with 20 atoms [a=6.144(3) Å, b=6.3715(14) Å, c=6.3759(15) Å, α= 93.84(2)°, β=107.34(3)°, γ=107.16(3)°, V=224.33(13) Å3 at 3.1 GPa]. Different pressure-time experimental paths can stabilise one or the other polymorph. Both structures are characterised by the presence of non-coplanar CO3 groups. The densities of CaCO3-III (2.99 g/cm3 at 2.8 GPa) and CaCO3-IIIb (2.96 g/cm3 at 3.1 GPa) are lower than aragonite, in agreement with the currently accepted view of aragonite as the thermodynamically stable Ca-carbonate phase at these pressures. The presence of different cation sites, with variable volume and coordination number (7-9), suggests however that these structures have the potential to accommodate cations with different sizes without introducing major structural strain. Indeed, this structure can be adopted by natural Ca-rich carbonates, which often exhibit compositions deviating from pure calcite. Mg-calcites are found both in nature (Frezzotti et al., 2011) and in experimental syntheses at conditions corresponding to deep subduction environments (Poli et al., 2009). At these conditions, the low pressure rhombohedral calcite structure is most unlikely to be stable, and, at the same

  18. The effect of methylglyoxal-bis(guanylhydrazone) on mitochondrial Ca(2+) fluxes.

    Science.gov (United States)

    Salvi, Mauro; Toninello, Antonio

    2002-01-15

    Methylglyoxal-bis(guanylhydrazone) (MGBG) induces a dose-dependent inhibition of the electrophoretic Ca(2+) uptake by rat liver mitochondria (RLM) without affecting the electrical membrane potential. MGBG is also able to inhibit the electroneutral Ca(2+) release from mitochondria. These effects result in a progressive increase of Ca(2+) level in suspending medium indicating that Ca(2+) uptake is inhibited at higher extent than Ca(2+) efflux. Spermine instead, induces a lowering of external Ca(2+) concentration. This action is reversed by MGBG which again raises the external Ca(2+) concentration then in the absence of spermine, though at a lower extent. The mechanism of MGBG effects and their implications on energy metabolism are discussed.

  19. Synthesis and photoluminescence of Ca-(Sn,Ti)-Si-O compounds

    International Nuclear Information System (INIS)

    Abe, Shunsuke; Yamane, Hisanori; Yoshida, Hisashi

    2010-01-01

    The phase relation of the compounds prepared in the CaO-SnO 2 -SiO 2 system at 1673 K and in the CaO-TiO 2 -SiO 2 system at 1573 K was investigated in order to explore new Ti 4+ -activated stannate phosphors. Solid solutions of Ca(Sn 1-x Ti x )SiO 5 and Ca 3 (Sn 1-y Ti y )Si 2 O 9 were synthesized at x = 0-1.0 and y = 0-0.10, respectively, and their crystal structures were analyzed by powder X-ray diffraction. Photoluminescence of these solid solutions was observed in a broad range of a visible light wavelength region under ultraviolet (UV) light excitation. The peaks of the emission band of Ca(Sn 0.97 Ti 0.03 )SiO 5 and Ca 3 (Sn 0.925 Ti 0.075 )Si 2 O 9 were at 510 nm under excitation of 252 nm and at 534 nm under excitation of 258 nm, respectively. The absorption edges estimated by the diffuse reflectance spectra were at 300 nm (4.1 eV) for CaSnSiO 5 and at 270 nm (4.6 eV) for Ca 3 SnSi 2 O 9 , suggesting that the excitation levels in Ca(Sn 1-x Ti x )SiO 5 were above the band gap of the host, although the levels in Ca 3 (Sn 1-y Ti y )Si 2 O 9 were within the band gap and near the conduction band edge.

  20. Influence of a chinese crude drug on Ca2+ influx and efflux in rat visceral organs:Investigation and evaluation by 45Ca

    International Nuclear Information System (INIS)

    Yang Yuanyou; Liu Ning; Mo Zhengji; Xie Jianping; Liao Jiali; Mo Shangwu

    2006-01-01

    The influences of a Chinese crude drug, Herba Epimedii (HE), on Ca 2+ influx and efflux in the isolated rat aorta and some visceral organs were evaluated by using 45 Ca as a radioactive tracer. Additionally, its protective effect on myocardial ischemia was investigated in live animals. The results indicated that HE has significant influence on Ca 2+ influx and efflux in the isolated rat aorta, heart, and kidney, in that it can markedly block 45 Ca entering into cell and can facilitate efflux of intracellular Ca 2+ . However, among the three kinds of extracts from HE, the alkali extracts have the most obvious effect on calcium channels in visceral organs. Even if the alkali extracts are diluted by water for 10 times, the material still has a rather strong inhibition effect on calcium channels. Fortunately, the three kinds of extracts have favorable protective effect on myocardial ischemia induced by drugs or by the ligation of the coronary artery. This is consistent with the results about the Ca 2+ influx and efflux obtained by isotope tracer technique, and implies that the Chinese crude drug has attractive potential for the treatment of heart, cerebrovascular and other diseases

  1. Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase

    DEFF Research Database (Denmark)

    Thastrup, Ole; Cullen, P J; Drøbak, B K

    1990-01-01

    . This hypothesis is strongly supported by the demonstration that thapsigargin causes a rapid inhibition of the Ca2(+)-activated ATPase activity of rat liver microsomes, with an identical dose dependence to that seen in whole cell or isolated microsome Ca2+ discharge. The inhibition of the endoplasmic reticulum...

  2. Electron radiation damages to dicalcium (Ca{sub 2}SiO{sub 4}) and tricalcium (Ca{sub 3}SiO{sub 5}) orthosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Noirfontaine, Marie-Noëlle de; Dunstetter, Frédéric [Laboratoire des Solides Irradiés, UMR CNRS 7642, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau Cedex (France); Courtial, Mireille [Laboratoire des Solides Irradiés, UMR CNRS 7642, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau Cedex (France); Université d’Artois, 1230 Rue de l’Université, CS 20819, F-62408 Béthune (France); Signes-Frehel, Marcel [Laboratoire des Solides Irradiés, UMR CNRS 7642, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau Cedex (France); Wang, Guillaume [Laboratoire Matériaux et Phénomènes Quantiques, UMR CNRS 7162, Université Paris Diderot, F-75205 Paris Cedex 13 (France); Gorse - Pomonti, Dominique [Laboratoire des Solides Irradiés, UMR CNRS 7642, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau Cedex (France)

    2016-05-01

    Electron radiation damages to dicalcium silicate (Ca{sub 2}SiO{sub 4}) and tricalcium silicate (Ca{sub 3}SiO{sub 5}) are reported for the first time in this paper. With increasing flux, between 2.7 × 10{sup 17} and 2.2 × 10{sup 22} e{sup −} cm{sup −2} s{sup −1}, decomposition into nanodomains of crystalline CaO plus an amorphous silica rich phase is first observed for both silicates, then amorphization at higher flux always for both silicates, and finally hole drilling but only for Ca{sub 3}SiO{sub 5}. These structural modifications are accompanied by a net reduction of Ca content under the electron beam depending on the silicate species. These radiation effects occur for values of flux and dose larger than in previously studied orthosilicates (like olivines), and much larger than in all tectosilicates.

  3. Plasma membrane Ca2+-ATPase 4: interaction with constitutive nitric oxide synthases in human sperm and prostasomes which carry Ca2+/CaM-dependent serine kinase

    OpenAIRE

    Andrews, Rachel E.; Galileo, Deni S.; Martin-DeLeon, Patricia A.

    2015-01-01

    Deletion of the gene encoding the widely conserved plasma membrane calcium ATPase 4 (PMCA4), a major Ca2+ efflux pump, leads to loss of sperm motility and male infertility in mice. PMCA4's partners in sperm and how its absence exerts its effect on fertility are unknown. We hypothesize that in sperm PMCA4 interacts with endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) which are rapidly activated by Ca2+, and that these fertility-modulating proteins are present...

  4. Spontaneous release from mossy fiber terminals inhibits Ni2+-sensitive T-type Ca2+ channels of CA3 pyramidal neurons in the rat organotypic hippocampal slice.

    Science.gov (United States)

    Reid, Christopher A; Xu, Shenghong; Williams, David A

    2008-01-01

    Mossy fibers (axons arising from dentate granule cells) form large synaptic contacts exclusively onto the proximal apical dendrites of CA3 pyramidal neurons. They can generate large synaptic currents that occur in close proximity to the soma. These properties mean that active conductance in the proximal apical dendrite could have a disproportionate influence on CA3 pyramidal neuron excitability. Ni(2+)-sensitive T-type Ca(2+) channels are important modulators of dendritic excitability. Here, we use an optical approach to determine the contribution of Ni(2+) (100 microM)-sensitive Ca(2+) channels to action potential (AP) elicited Ca(2+) flux in the soma, proximal apical and distal apical dendrites. At resting membrane potentials Ni(2+)-sensitive Ca(2+) channels do not contribute to the Ca(2+) signal in the proximal apical dendrite, but do contribute in the other cell regions. Spontaneous release from mossy fiber terminals acting on 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)-sensitive postsynaptic channels underlies a tonic inhibition of Ni(2+)-sensitive channels. Chelating Zn(2+) with CaEDTA blocks CNQX-sensitive changes in Ca(2+) flux implicating a mechanistic role of this ion in T-type Ca(2+) channel block. To test if this inhibition influenced excitability, progressively larger depolarizing pulses were delivered to CA3 pyramidal neurons. CNQX significantly reduced the size of the depolarizing step required to generate APs and increased the absolute number of APs per depolarizing step. This change in AP firing was completely reversed by the addition of Ni(2+). This mechanism may reduce the impact of T-type Ca(2+) channels in a region where large synaptic events are common.

  5. A Close Association of RyRs with Highly Dense Clusters of Ca2+-activated Cl− Channels Underlies the Activation of STICs by Ca2+ Sparks in Mouse Airway Smooth Muscle

    Science.gov (United States)

    Bao, Rongfeng; Lifshitz, Lawrence M.; Tuft, Richard A.; Bellvé, Karl; Fogarty, Kevin E.; ZhuGe, Ronghua

    2008-01-01

    Ca2+ sparks are highly localized, transient releases of Ca2+ from sarcoplasmic reticulum through ryanodine receptors (RyRs). In smooth muscle, Ca2+ sparks trigger spontaneous transient outward currents (STOCs) by opening nearby clusters of large-conductance Ca2+-activated K+ channels, and also gate Ca2+-activated Cl− (Cl(Ca)) channels to induce spontaneous transient inward currents (STICs). While the molecular mechanisms underlying the activation of STOCs by Ca2+ sparks is well understood, little information is available on how Ca2+ sparks activate STICs. In the present study, we investigated the spatial organization of RyRs and Cl(Ca) channels in spark sites in airway myocytes from mouse. Ca2+ sparks and STICs were simultaneously recorded, respectively, with high-speed, widefield digital microscopy and whole-cell patch-clamp. An image-based approach was applied to measure the Ca2+ current underlying a Ca2+ spark (ICa(spark)), with an appropriate correction for endogenous fixed Ca2+ buffer, which was characterized by flash photolysis of NPEGTA. We found that ICa(spark) rises to a peak in 9 ms and decays with a single exponential with a time constant of 12 ms, suggesting that Ca2+ sparks result from the nonsimultaneous opening and closure of multiple RyRs. The onset of the STIC lags the onset of the ICa(spark) by less than 3 ms, and its rising phase matches the duration of the ICa(spark). We further determined that Cl(Ca) channels on average are exposed to a [Ca2+] of 2.4 μM or greater during Ca2+ sparks. The area of the plasma membrane reaching this level is <600 nm in radius, as revealed by the spatiotemporal profile of [Ca2+] produced by a reaction-diffusion simulation with measured ICa(spark). Finally we estimated that the number of Cl(Ca) channels localized in Ca2+ spark sites could account for all the Cl(Ca) channels in the entire cell. Taken together these results lead us to propose a model in which RyRs and Cl(Ca) channels in Ca2+ spark sites localize

  6. Where Water is Oxidized to Dioxygen: Structure of the Photosynthetic Mn4Ca Cluster from X-ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yano, Junko; Yachandra, Vittal K.

    2007-10-24

    Light-driven oxidation of water to dioxygen in plants, algae and cyanobacteria iscatalyzed within photosystem II (PS II) by a Mn4Ca cluster. Although the cluster has been studied by many different methods, the structure and the mechanism have remained elusive. X-ray absorption and emission spectroscopy and EXAFS studies have been particularly useful in probing the electronic and geometric structure, and the mechanism of the water oxidation reaction. Recent progress, reviewed here, includes polarized X-ray absorption spectroscopy measurements of PS II single crystals. Analysis of those results has constrained the Mn4Ca cluster geometry to a setof three similar high-resolution structures. The structure of the cluster from the present study is unlike either the 3.0 or 3.5 Angstrom-resolution X-ray structures or other previously proposed models. The differences between the models derived from X-rayspectroscopy and crystallography are predominantly because of damage to the Mn4Ca cluster by X-rays under the conditions used for structure determination by X-ray crystallography. X-ray spectroscopy studies are also used for studying the changes in the structure of the Mn4Ca catalytic center as it cycles through the five intermediate states known as the Si-states (i=0-4). The electronic structure of the Mn4Ca cluster has been studied more recently using resonant inelastic X-ray scattering spectroscopy (RIXS), in addition to the earlier X-ray absorption and emission spectroscopy methods. These studies are revealing that the assignment of formaloxidation states is overly simplistic. A more accurate description should consider the charge density on the Mn atoms that includes the covalency of the bonds and delocalization of the charge over the cluster. The geometric and electronic structure of the Mn4Ca cluster in the S-states derived from X-ray spectroscopy are leading to a detailed understanding of the mechanism of the O-O bond formation during the photosynthetic water

  7. Prenatal nicotine and maternal deprivation stress de-regulate the development of CA1, CA3, and dentate gyrus neurons in hippocampus of infant rats.

    Directory of Open Access Journals (Sweden)

    Hong Wang

    Full Text Available Adverse experiences by the developing fetus and in early childhood are associated with profound effects on learning, emotional behavior, and cognition as a whole. In this study we investigated the effects of prenatal nicotine exposure (NIC, postnatal maternal deprivation (MD or the combination of the two (NIC+MD to determine if hippocampal neuron development is modulated by exposure to drugs of abuse and/or stress. Growth of rat offspring exposed to MD alone or NIC+MD was repressed until after weaning. In CA1 but not CA3 of postnatal day 14 (P14 pups, MD increased pyramidal neurons, however, in dentate gyrus (DG, decreased granule neurons. NIC had no effect on neuron number in CA1, CA3 or DG. Unexpectedly, NIC plus MD combined caused a synergistic increase in the number of CA1 or CA3 neurons. Neuron density in CA regions was unaffected by treatment, but in the DG, granule neurons had a looser packing density after NIC, MD or NIC+MD exposure. When septotemporal axes were analyzed, the synergism of stress and drug exposure in CA1 and CA3 was associated with rostral, whereas MD effects were predominantly associated with caudal neurons. TUNEL labeling suggests no active apoptosis at P14, and doublecortin positive neurons and mossy fibers were diminished in NIC+MD relative to controls. The laterality of the effect of nicotine and/or maternal deprivation in right versus left hippocampus was also analyzed and found to be insiginificant. We report for the first time that early life stressors such as postnatal MD and prenatal NIC exposure, when combined, may exhibit synergistic consequences for CA1 and CA3 pyramidal neuron development, and a potential antagonistic influence on developing DG neurons. These results suggest that early stressors may modulate neurogenesis, apoptosis, or maturation of glutamatergic neurons in the hippocampus in a region-specific manner during critical periods of neurodevelopment.

  8. Effect of vanadate and of removal of extracellular Ca2+ and Na+ on tension development and 45Ca efflux in rat and frog myocardium

    DEFF Research Database (Denmark)

    Gesser, H; Bonefeld-Jørgensen, Eva Cecilie

    1983-01-01

    Vanadate in the range 0-5 mM has positive inotropic effects on myocardial strips of frog and to a lesser extent on those of rat. Inhibiting the sarcolemmal Na+, Ca2+ exchange by a solution free of Ca2+ and Na+ caused a drop in 45Ca efflux and a transient increase in resting tension. These effects...... were more expressed for the frog than for the rat myocardium, which suggests that the Na+ for Ca2+ exchange across the cell membrane is more important in the frog than in the rat myocardium. A subsequent addition of vanadate at 2 or 5 mM had no effect on 45Ca efflux, while it increased the resting...... tension. This increase was higher for the frog than for the rat myocardium. These results suggest that the inotropic effects of vanadate may be due to an effect on membrane-bound Ca2+-ATPase....

  9. SNL/CA Environmental Management System Program Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Barbara L.

    2005-09-01

    The Sandia National Laboratories, California (SNL/CA) Environmental Management System (EMS) Program Manual documents the elements of the site EMS Program. The SNL/CA EMS Program was developed in accordance with Department of Energy (DOE) Order 450.1 and incorporates the elements of the International Standard on Environmental Management Systems, ISO 14001.

  10. Electronic structure of Ca, Sr, and Ba under pressure.

    Science.gov (United States)

    Animalu, A. O. E.; Heine, V.; Vasvari, B.

    1967-01-01

    Electronic band structure calculations phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure

  11. Clinical value of single or combined IRMA of CEA, CA19-9, CA72-4 and MG-Ag in diagnosis of gastric cancer

    International Nuclear Information System (INIS)

    Li Jiangang; Chen Zhong; Liu Yun; Zhang Jun

    2002-01-01

    Four tumor markers CEA, CA19-9, CA72-4 and MG-Ag are chosen in diagnosis of gastric cancer and 228 cases are detected with single or combined methods in all. The results indicate that the positive rates of single detection are all above 70% and that of MG-Ag is the highest (90.4%). Combined detections of two tumor markers, as judged by double positivity, the positive rate of MG + CA72-4 is the highest (70.6%), next is MG + CA19-9 (64.6%). It is suggested that MG-Ag is the first choice in single detection, MG + CA72-4 group is the first choice in double combined detections and different tumor markers could be chosen according to historic type in follow-up patients

  12. High-pressure densified solid solutions of alkaline earth hexaborides (Ca/Sr, Ca/Ba, Sr/Ba) and their high-temperature thermoelectric properties

    International Nuclear Information System (INIS)

    Gürsoy, M.; Takeda, M.; Albert, B.

    2015-01-01

    Solid solutions of alkaline earth hexaborides were synthesized and densified by spark plasma sintering at 100 MPa. The high-temperature thermoelectric properties (Seebeck coefficients, electrical and thermal diffusivities, heat capacities) were measured between room temperature and 1073 K. CaB 6 , SrB 6 , BaB 6 and the ternary hexaborides Ca x Sr 1−x B 6 , Ca x Ba 1−x B 6 , Sr x Ba 1−x B 6 (x = 0.25, 0.5, 0.75) are n-type conducting compounds over the whole compositional and thermal ranges. The values of the figure of merit ZT for CaB 6 (ca. 0.3 at 1073 K) were found to be significantly increased compared to earlier investigations which is attributed to the densification process. - Highlights: • Solid solutions of alkaline earth hexaborides were synthesized. • High-temperature thermoelectric properties of mixed calcium borides are excellent. • Spark plasma source densification results in high ZT values. • Borides are rare-earth free and refractory materials

  13. Solvent-free synthesis and application of nano-Fe/Ca/CaO/[PO{sub 4}] composite for dual separation and immobilization of stable and radioactive cesium in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Mallampati, Srinivasa Reddy, E-mail: srireddys@ulsan.ac.kr [Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749 (Korea, Republic of); Mitoma, Yoshiharu, E-mail: mitomay@pu-hiroshima.ac.jp [Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho Shobara City, Hiroshima 727-0023 (Japan); Okuda, Tetsuji [Environmental Research and Management Center, Hiroshima University, 1-5-3 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513 (Japan); Simion, Cristian [Politehnica University of Bucharest, Department of Organic Chemistry, Bucharest 060042 (Romania); Lee, Byeong Kyu [Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749 (Korea, Republic of)

    2015-10-30

    Graphical abstract: A possible pathway for immobilization with the nano-Fe/Ca/CaO/[PO{sub 4}] treatment (a) {sup 133}Cs is adsorbed onto the soil particles, (b) Cs encapsulation through the formation of immobile salts, and (c) solid (small/finer or larger/aggregate) soil fraction separation. - Highlights: • Nano-Fe/Ca/CaO/[PO{sub 4}] composite for Cs immobilization in soil was developed. • Enhanced cesium separation and immobilization was done in dry condition. • By SEM analysis the amount of cesium detectable on soil particle surface decreases. • Leachable cesium concentrations reduced, lower than the standard regulatory limit. • Nano-Fe/Ca/CaO/[PO{sub 4}] a highly potential amendment for the remediation of Cs. - Abstract: This study assessed the synthesis and application of nano-Fe/Ca/CaO-based composite material for use as a separation and immobilizing treatment of dry soil contaminated by stable ({sup 133}Cs) and radioactive cesium species ({sup 134}Cs and {sup 137}Cs). After grinding with nano-Fe/CaO, nano-Fe/Ca/CaO, and nano-Fe/Ca/CaO/[PO{sub 4}], approximately 31, 25, and 22 wt% of magnetic fraction soil was separated. Their resultant {sup 133}Cs immobilization values were about 78, 81, and 100%, respectively. When real radioactive cesium contaminated soil obtained from Fukushima was treated with nano-Fe/Ca/CaO/[PO{sub 4}], approximately 27.3 wt% of magnetic and 72.75% of non-magnetic soil fractions were separated. The highest amount of entrapped {sup 134}Cs and {sup 137}Cs was found in the lowest weight of the magnetically separated soil fraction (i.e., 80% in 27.3% of treated soil). Results show that {sup 134}Cs and {sup 137}Cs either in the magnetic or non-magnetic soil fractions was 100% immobilized. The morphology and mineral phases of the nano-Fe/Ca/CaO/[PO{sub 4}] treated soil were characterized using SEM–EDS, EPMA, and XRD analysis. The EPMA and XRD patterns indicate that the main fraction of enclosed/bound materials on treated soil

  14. Biodiesel production from soybean and Jatropha oils by magnetic CaFe2O4–Ca2Fe2O5-based catalyst

    International Nuclear Information System (INIS)

    Xue, Bao-jin; Luo, Jia; Zhang, Fan; Fang, Zhen

    2014-01-01

    Heterogeneous CaFe 2 O 4 –Ca 2 Fe 2 O 5 -based catalyst with weak magnetism was prepared by co-precipitation and calcination. It was characterized by various techniques including X-ray diffraction, X-ray photoelectron spectroscopy and temperature programmed desorption method. Its active components were identified as mainly Ca–Fe composite oxides such as CaFe 2 O 4 for transesterification. The magnetism was further strengthened by reducing its component of Fe 2 O 3 to Fe 3 O 4 –Fe under H 2 atmosphere for better magnetic separation. Both catalysts were used for the catalytic transesterification of soybean and Jatropha oils to biodiesel. The highest biodiesel yields for soybean oil of 85.4% and 83.5% were obtained over the weak and strong magnetic catalysts, respectively under the optimized conditions (373 K, 30 min, 15/1 methanol/oil molar ratio and 4 wt% catalyst). The catalysts could be recycled three times. Biodiesel production from pretreated Jatropha oil was tested with the magnetic CaFe 2 O 4 –Ca 2 Fe 2 O 5 –Fe 3 O 4 –Fe catalyst, and 78.2% biodiesel yield was obtained. The magnetic CaFe 2 O 4 –Ca 2 Fe 2 O 5 -based catalyst shows a potential application for the green production of biodiesel. - Highlights: • Magnetic catalyst was prepared by co-precipitation, calcination and reduction. • The catalyst was composed of CaFe 2 O 4 –Ca 2 Fe 2 O 5 –Fe 3 O 4 –Fe. • Biodiesel yields of 83.5% and 78.2% were achieved for soybean and Jatropha oils. • The catalyst was easily separated by a magnet and used for three cycles

  15. Effect of CaO addition on preparation of ferrotitanium from ilmenite by electrochemical reduction in CaCl{sub 2}−NaCl molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Li [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Hua, Yixin, E-mail: yxhua@kmust.edu.cn [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Xu, Cunying; Li, Jian; Li, Yan; Zhang, Qibo; Zhou, Zhongren; Zhang, Yadong [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); State Key Lab of Complex Nonferrous Metal Resources Clean Utilization, Kunming 650093 (China); Ru, Juanjian [Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2016-08-15

    Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl{sub 2}−NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol%CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. - Highlights: • Ferro-titanium was prepared from synthesized ilmenite in CaCl{sub 2}−NaCl molten salt. • CaO content has appreciable effect on the phase transformation of ilmenite reactant. • The optimized CaO content is 1 mol% which can significantly improve reaction rate. • The products are connected with each other to form strips as electrolysis time.

  16. Internal Ca2+ mobilization and secretion in bovine adrenal chromaffin cells

    DEFF Research Database (Denmark)

    Cheek, T R; Thastrup, Ole

    1989-01-01

    and the sesquiterpene lactone thapsigargin (TG), which releases internal Ca2+ without concomitant breakdown of inositol lipids or protein kinase C activation, to examine the events which follow depletion of the releasable Ca2+ store in these cells. Monitoring [Ca2+]i using Fura-2 demonstrated that TG released Ca2+ from......-state that was dependent on the continual entry of extracellular Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)...

  17. Effect of the tether on the Mg(II), Ca(II), Cu(II) and Fe(III) stability constants and pM values of chelating agents related to EDDHA.

    Science.gov (United States)

    Sierra, Miguel A; Gómez-Gallego, Mar; Alcázar, Roberto; Lucena, Juan J; Yunta, Felipe; García-Marco, Sonia

    2004-11-07

    The effect of the length and the structure of the tether on the chelating ability of EDDHA-like chelates have not been established. In this work, PDDHA (propylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid), BDDHA (butylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid) and XDDHA (p-xylylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid) have been obtained and their chemical behaviour has been studied and compared with that of EDDHA following our methodology. The purity of the chelating agents, and their protonation, Ca(II), Mg(II), Fe(III) and Cu(II) stability constants and pM values have been determined. The stability constants and pM values indicate that EDDHA forms the most stable chelates followed by PDDHA. However, the differences among the pFe values are small when a nutrient solution is used, and in these conditions the XDDHA/Fe(III) chelate is the most stable. The results obtained in this work indicate that all the chelating agents studied can be used as iron chlorosis correctors and they can be applied to soil/plant systems.

  18. Ensemble place codes in hippocampus: CA1, CA3, and dentate gyrus place cells have multiple place fields in large environments.

    Directory of Open Access Journals (Sweden)

    Eunhye Park

    Full Text Available Previously we reported that the hippocampus place code must be an ensemble code because place cells in the CA1 region of hippocampus have multiple place fields in a more natural, larger-than-standard enclosure with stairs that permitted movements in 3-D. Here, we further investigated the nature of hippocampal place codes by characterizing the spatial firing properties of place cells in the CA1, CA3, and dentate gyrus (DG hippocampal subdivisions as rats foraged in a standard 76-cm cylinder as well as a larger-than-standard box (1.8 m×1.4 m that did not have stairs or any internal structure to permit movements in 3-D. The rats were trained to forage continuously for 1 hour using computer-controlled food delivery. We confirmed that most place cells have single place fields in the standard cylinder and that the positional firing pattern remapped between the cylinder and the large enclosure. Importantly, place cells in the CA1, CA3 and DG areas all characteristically had multiple place fields that were irregularly spaced, as we had reported previously for CA1. We conclude that multiple place fields are a fundamental characteristic of hippocampal place cells that simplifies to a single field in sufficiently small spaces. An ensemble place code is compatible with these observations, which contradict any dedicated coding scheme.

  19. Inhibition of the sarco/endoplasmic reticulum (ER) Ca2+-ATPase by thapsigargin analogs induces cell death via ER Ca2+ depletion and the unfolded protein response

    DEFF Research Database (Denmark)

    Sehgal, Pankaj; Szalai, Paula; Olesen, Claus

    2017-01-01

    Calcium (Ca2+) is a fundamental regulator of cell signaling and function. Thapsigargin (Tg) blocks the sarco/endoplasmic reticulum (ER) Ca2+-ATPase (SERCA), disrupts Ca2+ homeostasis, and causes cell death. However, the exact mechanisms whereby SERCA-inhibition induces cell death are incompletely...... extensive drainage of the ER Ca2+ stores. This Ca2+ depletion was followed by markedly reduced cell proliferation rates and morphological changes that developed over 2–4 days and culminated in cell death. Interestingly, these changes were not accompanied by bulk increases in cytosolic Ca2+ levels. Moreover...... and their detrimental effects on cell viability. Furthermore, caspase activation and cell death were associated with a sustained unfolded protein response (UPR). We conclude that ER Ca2+ drainage and sustained UPR activation are key for initiation of apoptosis at low concentrations of Tg and Tg analogs, whereas high...

  20. Formation and decay of hot nuclei in 40 Ca + ''40 Ca at 35 MeV/nucleon

    International Nuclear Information System (INIS)

    Planeta, R.; Gawlikowicz, W.; Grotowski, K.

    2000-01-01

    Properties of multifragmentation of 'hot sources' produced in the 40 Ca + 40 Ca reaction have been studied at a beam energy of 35 MeV/nucleon. Two signatures of prompt multifragmentation which make use of special features of particle emission from the 'freeze out volume' together with an analysis of the reduced relative velocity between pairs of intermediate mass fragments indicate the presence of a transition from the sequential decay to prompt multifragmentation at an excitation energy of about 3 MeV/nucleon. (authors)