DEFF Research Database (Denmark)

ATPase, endoplasmic reticulum, calcium, ischaemia

UK PubMed Central (United Kingdom)

Recent studies suggest that calcium influx via L-type calcium channels is necessary for psychostimulant-induced behavioral sensitization. In addition, chronic amphetamine upregulates subtype...Full Text Available

UK PubMed Central (United Kingdom)

Within the cardiac cell, the movements of calcium ions are tightly regulated by a number of regulatory proteins including pumps, and channels. The sarcoplasmic reticulum (SR) is in large part...Full Text Available

UK PubMed Central (United Kingdom)

Background:The cardiac sodium–calcium exchanger (NCX1) is a key sarcolemmal protein for the maintenance of calcium homeostasis in the heart. Since heart failure...Full Text Available

International Nuclear Information System (INIS)

In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca"2"+-ATPase activity and "4"5Ca uptake were determined in brain P_2 fraction. Toxaphene inhibited both Ca"2"+-ATPase activity and "4"5Ca"2"+ uptake and the inhibition was dose dependent. Both substrate and Ca"2"+ activation kinetics of Ca"2"+-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca"2"+-ATPase activity and Ca"2"+ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca"2"+-ATPase activity and Ca"2"+ uptake and restoration by calmodulin suggests that toxaphene may impair active calcium transport mechanisms by decreasing ...

UK PubMed Central (United Kingdom)

BackgroundCalcium signaling plays an important role in B lymphocyte survival and activation, and is critically dependent on the inositol-1,4,5-tris-phosphate-induced...Full Text Available

UK PubMed Central (United Kingdom)

The transport of serine into tobacco (Nicotiana tabacum L. var. Xanthi) cells grown in liquid medium was studied. Serine transport was maximal below pH 4.0. A time-dependent stimulation...Full Text Available

UK PubMed Central (United Kingdom)

Amyloid proteins constitute a chemically heterogeneous group of proteins, which share some biophysical and biological characteristics, the principal of which are the high propensity to acquire an incorrect...Full Text Available

UK PubMed Central (United Kingdom)

Phospholemman (PLM), a member of the FXYD family of regulators of ion transport, is a major sarcolemmal substrate for protein kinases A and C in cardiac and skeletal muscle. In the heart, PLM...Full Text Available

UK PubMed Central (United Kingdom)

Inhibition of large conductance calcium-activated potassium (BK_Ca) channels mediates, in part, oxygen sensing by carotid body type I cells. However, BK_Ca channels remain active...Full Text Available

UK PubMed Central (United Kingdom)

Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand...Full Text Available

UK PubMed Central (United Kingdom)

Benzodiazepine withdrawal anxiety is associated with potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract Although photosynthetic thermotolerance has been investigated extensively in cotton leaves, reports on the biochemical influence of the pistil in promoting fertilization thermostability are limited. To evaluate the effect of temperature, genotype, and exogenous calcium application on fertilization and pistil biochemistry in cotton, thermosensitive (cv. ST4554 B2RF) and thermotolerant (cv. VH260) plants were grown under control (30/20-C) or high-temperature (38/20-C) conditions during flowering, and exogenous CaCl2 was applied to flowers 1-day prior to anthesis. Measured pistil parameters included fertilization efficiency; protein concentration; glutathione reductase, superoxide dismutase (SOD) and NADPH oxidase activities; and ATP and calcium levels. Exogenous calcium had no effec...

International Nuclear Information System (INIS)

Statements about the dynamic processes of uptake, transport, and deposition of Ca and Mg in norway spruce and Scots pine are made in this paper. Concerning the storage of these elements it is shown that there are great differences in their functional importance in cell metabolism. There is evidence that the role of Mg in enzyme and protein metabolism is of far greater significance for the understanding of Mg-deficiency symptoms than its function as the central atom of the chlorophyll complexes. In regard to the transport and especially to the incorporation of Ca into the needles differences between species were evident, expressing the special status of pine among the gymnosperms. With increasing needle age an accumulation of Ca-oxalate crystals, which are physiologically inert, could be proved for the studied conifers. This was interpreted as a 'detoxication' from surplus Ca to hold constant the level of the physiologically ...

Energy Technology Data Exchange (ETDEWEB)

A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin (({sup 125}I)IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of ({sup 125}I)IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, ({sup 125}I)IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly ...

UK PubMed Central (United Kingdom)

The DUR3 gene, which encodes a component required for active transport of urea in Saccharomyces cerevisiae, has been isolated, and its sequence has been determined. The deduced DUR3 protein profile...Full Text Available

Science.gov (United States)

Calcium-activated chloride channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane ...

UK PubMed Central (United Kingdom)

We have isolated a 4.785 Da protein from the nacreous layer of the sea snail Haliotis laevigata (greenlip abalone) shell after demineralization with acetic acid. The sequence of 41...Full Text Available

International Nuclear Information System (INIS)

The present study was undertaken to determine the involvement of calcium-protein kinase C pathway in the mechanism of action of Escherichia coli heat stable enterotoxin (STa) apart from STa-induced activation of guanylate cyclase in human colonic carcinoma cell line COLO-205, which was used as a model cultured cell line to study the mechanism of action of E. coli STa. In response to E. coli STa, protein kinase C (PKC) activity was increased in a time-dependent manner with its physical translocation from cytosol to membrane. Inhibition of the PKC activity in membrane fraction and inhibition of its physical translocation in response to IP_3-mediated calcium release inhibitor dantrolene suggested the involvement of intracellular store depletion in the regulation of PKC activity. Among different PKC isoforms, predominant involvement of calcium-dependent protein kinase C (PKC#alpha#) was ...

DEFF Research Database (Denmark)

The aim of the present study was to test a mathematical model of the biochemical processes in the parathyroid glands responsible for the secretion of parathyroid hormone resulting from extracellular calcium reduction. A double exponential curve described the parathyroid hormone secretion induced by rapid lowering of blood-ionized calcium in humans with normal as well as abnormal parathyroid tissue. Our data show that it was possible to establish a simple mathematical model of the parathyroid hormone response to blood-ionized calcium lowering, sufficient to fit experimental data obtained from patients with abnormal and normal parathyroid tissue. The fitted parameters showed no significant differences between patients with insulin-dependent diabetes mellitus and controls. In primary hyperparathyroidism, the parathyroid hormone production and steady-state transport across the cell membrane were increased, ...

CERN Document Server

Proteins are polymers of amino acids. These macromolecules are synthesized by intracellular machines called {\\it ribosome}. Although, traditionally, the experimental investigation of protein synthesis has been an active area of research in molecular cell biology, important quantitative models of this phenomenon have been reported mostly in the research journals devoted to statistical physics and related interdisciplinary topics. From the perspective of a physicist, protein synthesis is a phenomenon of {\\it classical transport of interacting ribosomes on a messenger RNA (mRNA) template} that dictates the sequence of the amino acids on the protein. Here we bring this frontier area of contemporary research into the classroom by appropriate simplification of the models and methods. In particular, we develope a simple toy model and analyze it by some elementary techniques of ...

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE Controlling vascular tone involves K+ efflux through endothelial cell small- and intermediate-conductance calcium-activated potassium channels (KCa2.3 and KCa3.1, respectively). We investigated the expression of these channels in astrocytes and the possibility that, by a similar mechanism, they might contribute to neurovascular coupling. EXPERIMENTAL APPROACH Transgenic mice expressing enhanced green fluorescent protein (eGFP) in astrocytes were used to assess KCa2.3 and KCa3.1 expression by immunohistochemistry and RT-PCR. KCa currents in eGFP-positive astrocytes were determined in situ using whole-cell patch clamp electrophysiology. The contribution of KCa3.1 to neurovascular coupling was investigated in pharmacological experiments using electrical field stimulatio...

Science.gov (United States)

White spot syndrome virus (WSSV) is the causative agent of the white spot disease of shrimp. Penaeus monodon were captured from Muttukadu Estuary in Chennai, India, transported to the laboratory and maintained in an aerated system with continuous water circulation-biofiltration. WSSV-free P. monodon were challenged by feeding them only once with WSSV-infected tissues of P. monodon. Cumulative mortality (100%) of the infected individuals was determined. Tissues from infected and uninfected shrimp such as muscles, hepatopancreas, heart, gills and eye tissues (100mg of each) and haemolymph (50 microl) were subjected to SDS-PAGE. In infected muscle tissue, six newly expressed proteins were detected. In infected haemolymph, four new proteins and three intensely expressed high molecular weight proteins were observed. Three intensely expressed high molecular weight proteins were detected ...

UK PubMed Central (United Kingdom)

Klebsiella oxytoca can use nitrate and nitrite as sole nitrogen sources. The enzymes required for nitrate and nitrite assimilation are encoded by the nasFEDCBA operon....Full Text Available

UK PubMed Central (United Kingdom)

SpoIIIE is an FtsK-related protein that transports the forespore chromosome across the Bacillus subtilis sporulation septum. We use membrane photobleaching and protoplast assays to...Full Text Available

UK PubMed Central (United Kingdom)

DYF-13, originally identified in C. elegans within a collection of dye-filling chemosensory mutants, is one of several proteins that have been classified as putatively involved...Full Text Available

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The present study was designed to investigate, in more detail, the mechanism of lead transport by the gastrointestinal tract and particularly the similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined in 3-week-old white Leghorn cockerels, raised on a commercial diet or special diets, using an in vivo ligated loop procedure. The dose administered into the loop usually contained 0.5 ..mu..Ci /sup 203/Pb (and/or 0.1 ..mu..Ci /sup 47/Ca), 0.01 mM lead acetate (and/or 1 mM CaCl/sub 2/) in 0.5 ml of 0.15 M NaCl, pH 6.5. It was shown that lead is rapidly taken up by the intestinal tissue, and only slowly transferred into the circulation whereas calcium, also accumulated rapidly by the tissue, is rapidly released from the tissue in the serosal direction. The absorption processes of these cations show similar responses to various experimental conditions (low ...

Energy Technology Data Exchange (ETDEWEB)

Severe pitting corrosion occurred in a horizontal steel pipeline used to transport multiphase fluid, including water, oil, and natural gas, after 2 months of service. The pitting corrosion rate was up to 42 mm/year. Chemical analysis, X-ray diffractometry, and EDAX showed that the corrosion products mainly consisted of Fe9S8, FeCO3, and NaCl. Calcium containing inclusions were also found in the matrix of the steel, which may accelerate corrosion. The early failure was attributed to the high proportion of water, the slow flow velocity, and the use of unqualified material. (Author)

Science.gov (United States)

The GntR-like protein NorG has been shown to affect Staphylococcus aureus genes involved in the resistance to quinolones and ?-lactams, such as those encoding the NorB and AbcA transporters. To identify the target genes regulated by NorG, we carried out transcriptional profiling assays using S. aureus RN6390 and its isogenic norG::cat mutant. Our data showed that NorG positively affected the transcription of global regulators mgrA, arlS, and sarZ. The three putative drug efflux pump genes most positively affected by NorG were the NorB efflux pump (5.1-fold), the MmpL-like protein SACOL2566 (5.2-fold), and the BcrA-like drug transporter SACOL2525 (5.7-fold). The S. aureus predicted MmpL protein showed 53% homology with the MmpL lipid transporter of Mycobacterium tuberculosis, and the putative SACOL2525 protein showed 87% homology with the ...

Energy Technology Data Exchange (ETDEWEB)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of /sup 203/Pb and /sup 47/Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol (1,25(OH)/sub 2/D/sub 3/) as their only source of the vitamin, the absorption of both /sup 47/Ca and /sup 203/Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in /sup 47/Ca and /sup 203/Pb absorption and in CaBP synthesis when the animals were treated with ...

Energy Technology Data Exchange (ETDEWEB)

The effects of purified Helminthosporium maydis T (HmT) toxin on active Ca/sup 2 +/ transport into isolated mitochondria and microsomal vesicles were compared for a susceptible (T) and a resistant (N) strain of corn (Zea mays). ATP, malate, NADH, or succinate could drive /sup 45/Ca/sup 2 +/ transport into mitochondria of corn roots. Ca/sup 2 +/ uptake was dependent on the proton electrochemical gradient generated by the redox substrates or the reversible ATP synthetase, as oligomycin inhibited ATP-driven CA/sup 2 +/ uptake while KCN inhibited transport driven by the redox substrates. Purified native HmT toxin completely inhibited Ca/sup 2 +/ transport into T mitochondria at 5 to 10 nanograms per milliliter while transport into N mitochondria was decreased slightly by 100 nanograms per milliliter toxin. Malate-driven Ca/sup 2 +/ transport in T mitochondria was ...

Science.gov (United States)

Several examples of agonist-directed trafficking of receptor signalling at 5-HT2A and 5-HT2C receptors have been reported that involve independent downstream transduction pathways. We now report the functional selectivity of a series of chemically diverse agonists at human (h)5-HT2A, h5-HT2B and h5-HT2C-VSV by examining two related responses, the upstream activation of Gq/11 proteins in comparison with its associated cascade of calcium mobilisation. At the h5-HT2A receptor, d-lysergic acid diethylamide (LSD) and the antiparkinsonian agents lisuride, bromocriptine and pergolide exhibit a higher potency for Gq/11 activation than calcium release in contrast with all the other tested ligands such as 5-HT, mCPP and BW723C86, that show an opposite preference of signalling pathway. Comparable observations are made at h5-HT2B and h5-HT2C-VSV receptors, suggesting a similar mechanism of functional selectivity for the three serotonin ...

Scientific Electronic Library Online (English)

Abstract in english The tegument surface of the adult schistosome, bounded by a normal plasma membrane overlain by a secreted membranocalyx, holds the key to understanding how schistosomes evade host immune responses. Recent advances in mass spectrometry (MS), and the sequencing of the Schistosoma mansoni transcriptome/genome, have facilitated schistosome proteomics. We detached the tegument from the worm body and enriched its surface membranes by differential extraction, before subjecting t (more) he preparation to liquid chromatography-based proteomics to identify its constituents. The most exposed proteins on live worms were labelled with impearmeant biotinylation reagents, and we also developed methods to isolate the membranocalyx for analysis. We identified transporters for sugars, amino acids, inorganic ions and water, which confirm the importance of the tegument plasma membrane in nutrient acquisition and solute balance. Enzymes, ...

International Nuclear Information System (INIS)

The human erythrocyte (RBC) Rh blood group system consists of a complex of distinct integral membrane polypeptides with physical properties common to the aminophospholipid transporter responsible for the transbilayer movement of phosphatidylserine (PS) in RBC. To assess the involvement of Rh polypeptides in PS translocation, the aminophospholipid translocase was labeled with a photoactivatable PS analogue, "1"2"5I-azido-PS, and with an inhibitor of PS transport, "1"2"5I-labeled 2-(2-pyridyldithio)ethylamine. The ability of monoclonal Rh antibodies to immunoprecipitate the labeled transporter was determined. Immunoprecipitated Rh polypeptides were found to be labeled with the aminophospholipid translocase markers, suggesting that Rh proteins are involved in the transbilayer movement of PS.

UK PubMed Central (United Kingdom)

Non-alcoholic fatty liver disease is a serious health problem linked to obesity and type 2 diabetes. To investigate the biological outcome and therapeutic potential of hepatic fatty acid uptake inhibition,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Radiation inactivation and sedimentation equilibrium analysis were used to determine the functional and physical size of the chicken hepatic membrane receptor that binds N-acetylglucosamine-terminated glycoproteins. Purified plasma membranes from chicken liver were irradiated with high energy electrons and assayed for 125I-agalactoorosomucoid binding. Increasing the dose of ionizing radiation resulted in a monoexponential decay in binding activity due to a progressive loss of binding sites. The molecular mass of the chicken lectin, determined in situ by target analysis, was 69,000 +/- 9,000 Da. When the same irradiated membranes were solubilized in Brij 58 and assayed, the binding protein exhibited a target size of 62,000 +/- 4,000 Da; in Triton X-100, the functional size of the receptor was 85,000 +/- 10,000 Da. Sedimentation equilibrium measurements of the purified binding protein yielded a lower limit molecular weight of 79,000 +/- 7,000. ...

Energy Technology Data Exchange (ETDEWEB)

The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, ...

Energy Technology Data Exchange (ETDEWEB)

Sulfate attack of cement-based materials remains an important problem for the durability assessment of containers and disposal engineering barriers dedicated to the long-term storage of radioactive wastes since underground water which may reach these elements contains small quantities of sulfates (7-31 mmol/1). This work contributes to the study of sulfate-induced damage mechanisms, to their understanding and modelling. The experimental phases of this study aimed at the understanding of the different physico-chemical phenomena involved during an external sulfate attack at following their evolution and their impact on the transport and mechanical properties of the material. Leaching experiments in pure water and in a solution of sodium sulfate (with a sulfate content of 15 mmol/1), have been performed simultaneously on OPC paste (w/c 0,4)in order to allow a comparison of test results. The frequent analysis of the leachant has shown a consumption of sulfate ions by ...

UK PubMed Central (United Kingdom)

Cellular calcium transient alternans are beat-to-beat alternations in the peak cytosolic calcium concentration exhibited by cardiac cells during rapid electrical stimulation or under pathological conditions....Full Text Available

UK PubMed Central (United Kingdom)

Background and objectives: Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium.Design,...Full Text Available

International Nuclear Information System (INIS)

We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) ...

International Nuclear Information System (INIS)

3-["1"2"3I]Iodo-L-#alpha#-methyl tyrosine (["1"2"3I]IMT) scintigraphy of extracranial malignant tumors has been described, but little is known about the transport systems involved in ["1"2"3I]IMT uptake into extracranial tumor cells. Here, the precise kinetics of ["1"2"3I]IMT transport into human Ewing's sarcoma cells (VH-64) was determined. The apparent Michaelis constant was of high affinity value (K_m=41.7#+-#3.9 #mu#M) and maximum transport velocity amounted to V_m_a_x=20.7#+-#0.6 nmol#centre dot#mg protein"-"1#centre dot#10 min"-"1. Inhibition experiments revealed the predominance of ["1"2"3I]IMT uptake via sodium-independent system L.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

DEFF Research Database (Denmark)

Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain ...

International Nuclear Information System (INIS)

Nop25 is a putative RNA binding nucleolar protein associated with rRNA transcription. The present study was undertaken to determine the mechanism of Nop25 localization in the nucleolus. Deletion experiments of Nop25 amino acid sequence showed Nop25 to contain a nuclear targeting sequence in the N-terminal and a nucleolar targeting sequence in the C-terminal. By expressing derivative peptides from the C-terminal as GFP-fusion proteins in the cells, a lysine and arginine residue-enriched peptide (KRKHPRRAQDSTKKPPSATRTSKTQRRRR) allowed a GFP-fusion protein to be transported and fully retained in the nucleolus. When the peptide was fused with cMyc epitope and expressed in the cells, a cMyc epitope was then detected in the nucleolus. Nop25 did not localize in the nucleolus by deletion of the peptide from Nop25. Furthermore, deletion of a subdomain (KRKHPRRAQ) in the peptide or amino acid substitution of ...

Energy Technology Data Exchange (ETDEWEB)

The production and uses are described for extracellular microbial polysaccharides (generically called emulsans) and for a new class of extracellular microbial protein-associated lipopolysaccharides (collectively called alpha-emulsans) produced by Acinetobacter Sp. ATCC 31012, its mutants or recombinants. Also included are the deproteinized lipopolysaccharides (collectively called apoemulsans) obtained from such emulsans, as well as to the divalent metal, ammonium, and quaternary ammonium salts of such emulsans and apoemulsans. The materials can be used (1) in cleaning oil-contaminated vessels used to transport or store crude oil or petroleum fractions in such a manner that the residual oil may be recovered for fuel value or for refining and (2) in enhanced oil recovery.

Science.gov (United States)

An evaluation was made of possible hazardous working conditions at the ASARCO Globe facility, Denver, Colorado. The facility was involved in the recovery of cadmium from baghouse dust, a waste byproduct of nonferrous smelters. A medical study of kidney function was conducted in 45 current or former cadmium production workers; results were compared to those for 35 hospital workers. Kidney abnormalities were more common and more severe in the cadmium workers than in the hospital workers. Abnormalities of proximal tubular function included reduced reabsorption of beta-2-microglobulin, retinol binding protein, calcium and phosphate. Glomerular dysfunction was evidenced as elevated serum creatinine. As length of exposure to cadmium increased, changes became more apparent in workers. No reversal of the conditions was noted in workers who had ceased to be exposed to cadmium some time before the study. The authors conclude that occupational ...

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

A novel single-chain immunotoxin was constructed by combining a CD33-specific single chain Fv (scFv) antibody fragment with an engineered variant of Pseudomonas exotoxin A (ETA). The variant toxin carries the KDEL peptide at its C-terminus, a cellular peptide mediating improved retrograde transport to the endoplasmic reticulum. The purified recombinant fusion protein induced potent apoptosis of the human myeloid cell lines U937, HL-60 and THP-1. Up to 98% of U937 cells were eliminated after treatment for 72 h with a single dose of 500 ng/ml (c. 7 nmol/l). Killing was antigen-specific and occurred by apoptosis. A control protein, consisting of a CD19-specific scFv antibody fragment fused to the ETA-KDEL toxin, failed to induce death of the CD19-negative cell lines U937, HL-60 and THP-1. The CD33-ETA toxin also mediated apoptosis of fresh patient-derived acute myeloid leukaemia cells from bone marrow and peripheral blood. The ...

Science.gov (United States)

The insulin signaling pathway, involving protein kinase B (PKB) and mitogen-activated protein kinase (MAPK), mediates the biological response to insulin and several growth factors and cytokines. To investigate the correlation between glucose transporter (Glut) biosynthesis and the insulin signaling pathway activated by novel compounds of Liriope platyphylla (LP9M80-H), alterations in Glut and key protein expression in the insulin signaling pathway were analyzed in the liver and brain of ICR mice treated with LP9M80-H. An in vitro assay showed that the highest level of insulin concentration was observed in the LP9M80-H-treated group, followed by the LP-H, LP-M, LP-E, and LP9M80-C-treated groups. Therefore, LP9M80-H was selected for use in studying the detailed mechanism of the insulin signaling pathway in animal systems. In an in vivo experiment, LP9M80-H induced a significant increase in glucose levels ...

CERN Document Server

We have carried out studies on the rheological properties of regenerated silk fibroin (RSF) solution using video microscopy. The degummed silk from the Bombyx mori silkworm was used to prepare RSF solution by dissolving it in calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by tracking the position of an embedded micron-sized polystyrene bead within the RSF solution through video imaging. The time dependent mean squared displacement (MSD) of the bead in solution and hence, the complex shear modulus of this solution was calculated from the bead's position information. An optical tweezer was used to transport and locate the bead at any desired site within the micro-volume of the sample, to facilitate the subsequent free-bead video analysis. We present here the results of rheological measurements of the silk polymer network in solution over a frequency range, whose upper limit is the frame capture rate of our camera, at ...

Science.gov (United States)

Extracellular matrix (ECM) comprises a rich meshwork of proteins and proteoglycans, which not only contains biological cues for cell behavior, but is also a reservoir for binding growth factors and controlling their release. Here we aimed to create a suitable bony microenvironment with cell-derived ECM and biodegradable ?-tricalcium phosphate (?-TCP). More specifically, we investigated whether the ECM produced by bone marrow-derived mesenchymal stem cells (hBMSC) on a ?-TCP scaffold can bind bone morphogenetic protein-2 (BMP-2) and control its release in a sustained manner, and further examined the effect of ECM and the BMP-2 released from ECM on cell behaviors. The ECM was obtained through culturing the hBMSC on a ?-TCP porous scaffold and performing decellularization and sterilization. SEM, XPS, FTIR, and immunofluorescent staining results indicated the presence of ECM on the ?-TCP and the amount of ECM increased with the incubation time. ...

International Nuclear Information System (INIS)

2-Azido[#alpha#-"3"2P]adenosine diphosphate (2-azido[#alpha#-"3"2P]ADP) has been used to photolabel the ADP/ATP carrier in beef heart mitochondria. In reversible binding assays carried out in the dark, this photoprobe was found to inhibit ADP/ATP transport in beef heart mitochondria and to bind to two types of specific sites of the ADP/ATP carrier characterized by high-affinity binding (K/sub d/ = 20 #mu#M) and low-affinity binding (K/sub d/ = 400 #mu#M). In contrast, it was unable to bind to specific carrier sites in inverted submitochondrial particles. Upon photoirradiation of beef heart mitochondria in the presence of 2-azido[#alpha#-"3"2P]ADP, the ADP/ATP carrier was covalently labeled. After purification, the photolabeled carrier protein was cleaved chemically by acidolysis or cyanogen bromide and enzymatically with the Staphylococcus aureus V8 protease. In the ADP/ATP carrier protein, which is 297 amino acid residues ...

International Nuclear Information System (INIS)

The hypothesis that intracellular Ca"2"+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca"2"+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl_2 and the Ca"2"+ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl_2 from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 #mu#M quin-2 or quin-2 AM had no ...

UK PubMed Central (United Kingdom)

Skeletal muscle uses calcium as a second messenger to respond and adapt to environmental stimuli. Elevations in intracellular calcium levels activate calcineurin, a serine/threonine phosphatase, resulting...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundCalcium homeostasis is a known target of several environmental toxicants including lead and mercury.ObjectiveOur goal was to determine...Full Text Available

UK PubMed Central (United Kingdom)

Objectives To assess the effectiveness of calcium supplementation for improving bone mineral density in healthy children and to determine if any effect is modified by other factors and...Full Text Available

Science.gov (United States)

Names Ca+2; Serum calcium; Ca++ References Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Ausiello D, eds. Cecil...

UK PubMed Central (United Kingdom)

T-type calcium channels are responsible for generating low-threshold spikes that facilitate burst firing and neurotransmitter release in neurons. GnRH neurons exhibit burst firing, but the underlying...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Lectin is a generic name of sugar binding protein in living organisms. With an objective to clarify physiological functions of lectin in marine invertebrates and utilize it as a useful material in the bio-chemical industry, studies were carried out on the chemical structure, distribution in living organisms and structural changes of lectin. Lectin is involved with such physiological actions as immunity reactions, generation and differentiation, Ca fixation and symbiosis. Lectin is one of the main components of lymph fluid in shellfish and crustacean, and is a multi-functional polymer that is related with foreign substance recognition, Ca transport, and shell formation. Lectin of a certain kind shows strong actions to accelerate cell division. Organs and cells were cultivated for lectin producing organs and lectin producing cells to verify the production thereof. Elucidation was attempted in a molecular level on such physiological functions as ...

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The sucrose derivative 6'-deoxy-6'-(2-hydroxy-4-azido)benzamidosucrose (6'-HABS) was prepared from sucrose (via 6'-deoxy-6'-aminosucrose) and 4-amino-salicylic acid. 6'-HABS is a competitive inhibitor of sucrose influx into protoplasts from developing soybean cotyledons and of sucrose binding to membranes from the bacteria P. saccharophila. The Ki for inhibition in the soybean protoplasts was 75..mu..M. 6'-Deoxy-6'-(2-hydroxy-3-/sup 125/Iodo-4-azido)benzamidosucrose was prepared by lactoperoxidase iodination of 6'-HABS. Upon photolysis in the presence of membranes from P saccharophila, label from the photoprobe is incorporated into a sucrose inducible polypeptide of mass 84 KD in SDS-PAGE. The polypeptide is protected from labeling by the inclusion of sucrose in the photolysis mixture. Photolysis conditions which lead to specific labeling of the sucrose protectable polypeptide in bacterial membranes also ...

KoreaScience (Korea)

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Science.gov (United States)

... interactive surfaces and interfaces, and 3) the more complex a ... carbonate or calcium phosphate with a thin interface ... diameter) for nerve prosthesis. ...

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This patent describes a preflush fluid for preventing lost circulation during the cementing of a well, the fluid consisting essentially of: (a) water; (b) about 10 to about 30 percent by weight of water (% BWOW) cement; (c) about 5 to about 30% BWOW calcium sulfate selected from the group consisting of calcium sulfate hemihydrate, calcium sulfate dihydrate, and mixtures thereof; and (d) an alkali metal-containing quick-hardening accelerator.

International Nuclear Information System (INIS)

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

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When labeled cAMP is incubated with isolated mitochondria from rat liver, it penetrates not only through the outer membrane of the mitochondria but also into the mitoplasts, where it is accumulated chiefly in the matrix. Damage to the mitochondrial membrane by freezing-thawing promotes not an influx but an efflux of cAMP out of the mitoplasts. A substantial part of the labeled nucleotide in all the investigated submitochondrial fractions was identified as intact cAMP by the method of thin-layer chromatography. The transport of cAMP into the mitochondria can explain the activation of their functions by the hormones that activate cytoplasmic adenylate cyclase and by extramitochondrial (cytosol) cAMP, as well as the presence of cAMP-dependent protein kinase and cAMP-phosphodiesterase in the mitochondria.

CERN Document Server

Motivated by recent experiments on KIF1A, a representative member of single-headed kinesin motor proteins family, we develop a theoretical model of intra-cellular transport by mutually interacting molecular motors. The model explicitly accounts not only for the hydrolysis of ATP, but also for the ratchet mechanism which is believed to drive each individual KIF1A motor. We study the model by a combination of analytical and numerical techniques. A remarkable feature of this model is that all the parameters in it can be completely evaluated from experimental data. Our results in the dilute limit are in excellent quantitative agreement with the empirical data from single molecule experiments. In the high density regime the predictions of the model also agree qualitatively with the corresponding experimental observations. We derive a phase diagram that shows the influence of hydrolysis and Langmuir kinetics on the collective spatio-temporal ...

UK PubMed Central (United Kingdom)

The intracellular concentration of protein may be as high as 400 mg per ml; thus it seems inevitable that within the cell, numerous protein-protein contacts are constantly occurring. A basic biochemical...Full Text Available

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X-ray diffraction, infrared spectroscopy, thermal analysis, scanning electron microscopy, and particle size analysis were used to characterize the product of the thiosulfate process. It was found to consist of a mixture of a solid solution of calcium sulfate in calcium sulfite hemihydrate, calcium sulfate dihydrate, and calcium carbonate. Reactions taking place on heating the byproduct were identified in oxidizing and reducing atmospheres. Pure calcium sulfite hemihydrate as well as solid solutions of CaSO[sub 4] in CaSO[sub 3] [center dot] (1/2)H[sub 2]O with different sulfate concentrations were synthesized in the laboratory. Thermal analyses of pure solid solutions proved that the higher the sulfate content, the higher is the dehydration temperature. Accordingly, taking SO[sub 4][sup 2[minus

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The authors have localized and characterized 2-125I-iodomelatonin binding sites in the chicken brain using in vitro quantitative autoradiography. Binding sites were widely distributed throughout the chicken brain, predominantly in regions associated with the visual system. The specific binding of 2-125I-iodomelatonin to discrete chicken brain areas was found to be saturable, reversible, and of high affinity. The specific binding of 2-125I-iodomelatonin (75 pm) was quantitated for 40 identifiable brain regions. Eight brain regions were chosen for binding characterization and pharmacological analysis: optic tectum, Edinger-Westphal nucleus, oculomotor nucleus, nucleus rotundus, ventral supraoptic decussation, ventrolateral geniculate nucleus, neostriatum, and ectostriatum. These regions showed no rostral-caudal gradient in 2-125I-iodomelatonin specific binding, and saturation analysis revealed a single class of high-affinity sites with KD values in the range of 33-48 pM and receptor site ...

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Development of selective serotonin transporter (SERT) tracers for single-photon emission tomography (SPET) is important for studying the underlying pharmacology and interaction of specific serotonin reuptake site inhibitors, commonly used antidepressants, at the SERT sites in the human brain. In search of a new tracer for imaging SERT, IDAM (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol) was developed. In vitro characterization of IDAM was carried out with binding studies in cell lines and rat tissue homogenates. In vivo binding of [[sup 125]I]IDAM was evaluated in rats by comparing the uptakes in different brain regions through tissue dissections and ex vivo autoradiography. In vitro binding study showed that IDAM displayed an excellent affinity to SERT sites (K[sub i]=0.097 nM, using membrane preparations of LLC-PK[sub 1] cells expressing the specific transporter) and showed more than 1000-fold of selectivity for SERT over ...

UK PubMed Central (United Kingdom)

A large group of diseases, termed protein misfolding disorders, share the common feature of the accumulation of misfolded proteins. The possibility of a common mechanism underlying either the pathogenesis...Full Text Available

UK PubMed Central (United Kingdom)

CAAX proteins are widely involved in global cellular functions such as proliferation, differentiation, and carcinogenesis. As an important modulator of biological activity, signal transduction via protein...Full Text Available

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The goal of this work was to develop a process flow diagram to economically produce a clean-burning fuel from fine Illinois coal. To accomplish this, the process of pelletizing fine coal with calcium hydroxide, a sulfur capturing sorbent, was investigated. Carbonation, which is the reaction of calcium hydroxide with carbon dioxide (in the presence of moisture) to produce a bonding matrix of calcium carbonate, was investigated as a method for improving pellet quality and reducing binder costs. Proper moisture level is critical to allow the reaction to occur. If too much moisture is present in a pellet, the pore spaces are filled and carbon dioxide must diffuse through the water to reach the calcium hydroxide and react. This severely slows or stops the reaction. The ideal situation is when there is just enough moisture to coat the calcium hydroxide allowing for the reaction to ...

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Wet limestone scrubbing is once again becoming a popular technology for removal of sulfur dioxide (SO{sub 2}) from power plant emissions. Critical to the operation of wet limestone flue gas desulfurization (FGD) systems is accurate chemical analysis of scrubber solids. The analytical technique of thermogravimetry is ideal for this application, as the instrument can give precise readings of the principal scrubber solids components, calcium sulfite/sulfate hemihydrate, calcium sulfate dihydrate (gypsum), and unused calcium carbonate. The data provides plant chemists, engineers, and operators with information needed to fine-tune scrubber operation and detect process upsets. (orig.)

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PMID:20880255

KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

Vitamin D is now known to be of physiological importance outside of bone health and calcium homeostasis, and there is mounting evidence that it plays a beneficial role in the prevention and/or treatment...Full Text Available

UK PubMed Central (United Kingdom)

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The spontaneous precipitation of calcium sulfate in supersaturated solutions over the temperature range between 25.0 and 80.0 C was investigated by monitoring the solution specific conductivity during desupersaturation. From measurements of the induction times preceding the onset of precipitation the surface energy of the forming solid, identified as gypsum, was found between ca. 12 and 25 mJ/m{sup 2} for the temperature range between 80.0 and 25.0 C, respectively. Kinetics analysis showed that over 50 C it is possible that anhydrous calcium sulfate is forming as a transient phase converting into the more stable calcium sulfate dihydrate. The linear dependence of the rates of precipitation on the relative solution supersaturation suggested a mechanism according to which the growth units are integrated into the active sites of the supercritical nuclei by surface diffusion. According to the morphological examination of the ...

International Nuclear Information System (INIS)

... activation analysis aluminium 28 calcium 49 chlorine 38 cotton plants li-drifted

Science.gov (United States)

A control group of geese (Anser anser) on a normal calcium diet for egg laying poultry was compared to egg laying geese on a calcium deficient diet. The ultimate compressive strength and modulus of elasticity of femoral cortical bone from each group were determined by compressing right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The bending strength and bending modulus of elasticity of tibial cortical bone were determined by three point bend tests on rectangular prisms which were approximately 25 mm by 0.8 mm by 0.8 mm. Bone calcium content and eggshell calcium content were determined by atomic absorption spectrophotometry. Blood samples were analyzed for free calcium ion concentration. Histological observations included studies of cross-sectional microradiographs, examinations of cross sections stained by a modified Masson's technique, and a determination ...

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The reaction of the retinylidene Schiff base in bacteriorhodopsin (bR) to the water-soluble reagent hydroxylamine is enhanced by greater than 2 orders of magnitude under illumination. We have used this reaction as a probe for changes in Schiff base reactivity during the photocycle of wild-type bR and mutants defective in proton transport. We report here that under illumination at pH 6, the D85N mutant has a 20-fold lower rate and the D212N mutant has a greater than 4-fold higher rate for the light-dependent reaction with hydroxylamine compared with wild-type bR. In contrast, the reactivities of wild-type bR and the D96N and T46V mutants are similar. It has been previously shown that the D96N and T46V replacements have no significant effect on the kinetics of M formation but have dramatic effects on rate of the decay of M. We therefore conclude that the hydroxylamine reaction occurs before formation of the M intermediate. Most likely it occurs at the L stage of the ...

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Sheep red blood cells (SRBCs) were labelled with a concanavalin A-luminol-bovine serum albumin conjugate specific for the transmembrane anion transport protein (Band 3) and exposed to 2450-MHz continuous-wave microwave radiation at an average specific absorption rate of 91W/kg for 10 min. The temperature was held constant at 25, 37, 40, 42, or 45C with an airflow heat-exchange system. Following exposure to microwave or air heating, the decrease in residual base-activated chemiluminescence (CL) of the SRBCs was measured as an indication of infield oxidase activity. Air heating resulted in a significant decrease in residual CL at temperatures above 37C (74% decrease at 45C). Microwave radiation inhibited the decline in residual CL above 37C. At 45C the inhibition was 40%. The results suggest microwave radiation either reversibly altered the thermodynamics of oxygen binding to haemoglobin or failed to energize a significant portion of the ...

UK PubMed Central (United Kingdom)

Brushite (CaHPO₄·2H₂O) was considered to govern the formation of renal calculus of calcium phosphate origin. The degree of saturation of urine with respect to this phase...Full Text Available

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The role played by calcium sulfite in the flue gas desulfurization of lime/limestone scrubbers makes it desirable to work out its thermodynamic properties. A thermogravimetric apparatus was used to study the equilibria between calcium sulfite hemihydrate and calcium sulfite anhydrite under different conditions. Efforts were made to analyze the difficulties encountered in the dynamic approach to equilibration after calcium sulfate dihydrate failed in calibration of the apparatus. Finally, the kinetics and thermodynamics for the dissociation of calcium sulfite hemihydrate were examined. The confirmation of Engel-Brewer's correlation between the electronic configuration and crystal structure in metallic systems has long been pursued in this group by studying the Lewis-acid-base interactions. Tantalum-iridium alloys of different compositions were brought into equilibrium with ...

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CERN Document Server

Role of organic acids in promoting colloidal transport of mercury from mine tailings

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This paper presents a supernetwork equilibrium model integrating supply chain networks with a transport network, namely, a supply chain-transport supernetwork equilibrium model. The model takes into account the behaviour of freight carriers and transport network users to endogenously determine the transport costs generated in the supply chain networks. The interaction between transport network and supply chain networks can also be examined. Results of the numerical tests reveal that the improvement of transport network could enhance the efficiency of supply chain networks. The paper makes contributions to modelling of supply chain networks as well as to that of transport networks.

UK PubMed Central (United Kingdom)

Known vertebrate GATA proteins contain two zinc fingers and are required in development, whereas invertebrates express a class of essential proteins containing one GATA-type zinc finger. We isolated...Full Text Available

UK PubMed Central (United Kingdom)

Storage proteins are deposited into protein storage vacuoles (PSVs) during plant seed development and maturation and stably accumulate to high levels; subsequently, during germination the storage...Full Text Available

UK PubMed Central (United Kingdom)

The changes in protein species synthesized during early Drosophila embryogenesis were characterized by two-dimensional electrophoresis. Of the 261 proteins scored, 68 (26%) show dramatic changes in...Full Text Available

UK PubMed Central (United Kingdom)

A protein evolution strategy is described by which double-stranded DNA fragments encoding defined E. coli protein secondary structural elements (α-helices, β-strands...Full Text Available

UK PubMed Central (United Kingdom)

We have used the two-electrode voltage clamp technique and the patch clamp technique to investigate the regulation of ROMK1 channels by protein-tyrosine phosphatase (PTP) and protein-tyrosine...Full Text Available

UK PubMed Central (United Kingdom)

A heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)propionate, was synthesized. Its N-hydroxysuccinimide ester group reacts with amino groups and the 2-pyridyl disulphide structure reacts...Full Text Available

UK PubMed Central (United Kingdom)

Protein modifications such as phosphorylation are often studied by two-dimensional gel electrophoresis since the perturbation in the protein’s pI value is readily detected by this method....Full Text Available

UK PubMed Central (United Kingdom)

The Protein Data Bank in Europe (PDBe; pdbe.org) is actively involved in managing the international archive of biomacromolecular structure data as one of the partners in the Worldwide Protein Data Bank...Full Text Available

UK PubMed Central (United Kingdom)

The activity of Src-related protein-tyrosine kinases is repressed by the phosphorylation of a conserved carboxyl-terminal tyrosine by another cytoplasmic protein-tyrosine kinase termed p50csk. In this...Full Text Available

UK PubMed Central (United Kingdom)

In this study, we investigated on a systems level how complex protein interactions underlying cell polarity in yeast determine the dynamic association of proteins with the polar cortical domain (PCD)...Full Text Available

UK PubMed Central (United Kingdom)

Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available

UK PubMed Central (United Kingdom)

Ethylene rapidly and transiently up-regulates the activity of several monomeric GTP-binding proteins (monomeric G proteins) in leaves of Arabidopsis as determined by two-dimensional gel electrophoresis...Full Text Available

UK PubMed Central (United Kingdom)

Computer-assisted analysis revealed a striking sequence similarity between the putative 24-kDa protein (p24) encoded by open reading frame (ORF) 5 of beet yellows closterovirus and the coat protein...Full Text Available

UK PubMed Central (United Kingdom)

Tooth enamel biomineralization is mediated by enamel proteins synthesized by ameloblast cells. Two classes of proteins have been described: enamelins and amelogenins. In lower vertebrates the absence...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe fast growing Protein Data Bank contains the three-dimensional description of more than 45000 protein- and nucleic-acid structures today. The large majority of the data...Full Text Available

UK PubMed Central (United Kingdom)

Alpha-hemoglobin-stabilizing protein (AHSP) is an erythroid-specific protein that acts as a molecular chaperone for the free α chains of hemoglobin. Evidence strongly suggests...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Endogenous opioid peptides (EOP) are molecules affecting many biological functions influencing productive and reproductive performance. They increase in stress conditions and interact with specific opioidergic receptors (OR): delta, kappa and mu. Several studies in other animal species suggest that they can also affect sperm cell motility. In fish the ionic external environment modulates the increase of intracellular calcium ion that is required to activate sperm motility after spawning. In mammals OR are functionally associated to calcium channels and in fishes calcium is highly required for fish sperm activation. In this study the presence of OR on spermatozoa of two Perciform fish, the sharpsnout seabream (Diplodus puntazzo, family Sparidae) and the European sea bass (Dicentrarchus labr...

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This is a process for producing calcium sulfate dihydrate during desulfurization of stack gases from power station boilers, where the stack gases are introduced into a washing tower and are treated with a washing water suspension containing lime in the washing tower, where oxygen in the form of air or of air enriched in oxygen is also blown into the washing tower, and where the washing water suspension drawn off from the washing tower is fed back to the washing tower at a temperature of 45 to 50/sup 0/C in the circuit and at least part of the flow goes via a thickener and where calcium sulfate dihydrate slurry is drawn off from the thickener.

British Library Electronic Table of Contents (United Kingdom)

Mineral carbonation is based on the reaction of carbon dioxide with metal-oxide bearing minerals, usually containing magnesium or calcium silicate, to form hardly soluble carbonates and other solid byproducts. The concept is based on acceleration of the naturally occurring rock weathering process. In the present work the calcium silicate is present in the mineral, wollastonite. To accelerate the process and make it potentially useful for practical applications, mineral carbonation is conducted here using an indirect two-step route in which the reactive component (Ca^2^+ ions in considered case) is first extracted from the mineral matrix and afterwards carbonated. Two solid byproducts are formed in this process: silica in the extraction step and calcium carbonate in the carbonation step. In...

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To examine the hormonal regulation of the ATP-dependent Ca{sup 2+} pump in the kidneys, the ATP-dependent Ca{sup 2+} uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium ({sup 45}Ca{sup 2+}) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The V{sub max} of the Ca{sup 2+} pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca{sup 2+} pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca{sup 2+} pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca{sup 2+} pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats. (author).

International Nuclear Information System (INIS)

This paper describes stable strontium as composed of four stable isotopes ( Sr 88, Sr 87, Sr 86, and Sr 84), of which Sr 88 contributes more than 82% to its composition. Strontium exists in three crystalline, plymorphic forms; face-centered cubic alpha form, hexagonal beta form and body-centered cubic gamma form. Strontium occupies in many physicochemical aspects an intermediate position between calcium and barium, as does the solubility of strontium salts. As a result of its oxidation potential, strontium readily forms oxides, halides, and sulfide. The author proposes that the slight discrimination against strontium incorporation into bony tissues may be due to the difference in ionic potential (14%) between strontium and calcium. Ionic potential is an indicator of the strength of ionic bonds: strontium has a smaller ratio of ionic charge to ionic radius when compared with calcium.

British Library Electronic Table of Contents (United Kingdom)

Summary: Protein features are often displayed along the linear sequence of amino acids that make up that protein, but in reality these features occupy a position in the folded proteins 3D space. Mapping sequence features to known or predicted protein structures is useful when trying to deduce the function of those features and when evaluating sequence or structural predictions. To facilitate this goal, we developed PDBpaint, a simple tool that displays protein sequence features gathered from bioinformatics resources on top of protein structures, which are displayed in an interactive window (using the Jmol Java viewer). PDBpaint can be used either with existing protein structures or with novel structures provided by the user. The current version of PDBpaint allows the visualization of annot...

UK PubMed Central (United Kingdom)

We identify new organelles associated with the vacuolar system in plant cells. These organelles are defined biochemically by their internal content of three integral membrane proteins: a chimeric reporter...Full Text Available

Science.gov (United States)

Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein ...

UK PubMed Central (United Kingdom)

Transformed Drosophila Kc cell lines, resistant to methotrexate, an inhibitor of de novo purine and pyrimidine synthesis, have been obtained by calcium phosphate transfection of plasmids containing...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The crystallization of calcium sulfate from aqueous solutions with NaCl is both geological and industrial interest because NaCl is the dominant solute in natural brines and many industrial fluids. Induction periods for the nucleation of calcium sulfate dihydrate were experimentally determined as a function of supersaturation in NaCl solutions from 0 to 6 m at 25 C and in 3.0-m NaCl solutions at temperatures from 25 to 90 C. Using classic nucleation theory, the interfacial tension between gypsum and 3.0-m NaCl solution was estimated to be about 39 mJ/m[sup 2] at 25 C and increases with increasing temperature (to 63 mJ/m[sup 2] at 90 C). It was observed that the induction period decreases with increasing NaCl concentrations up to 3 m and then starts to increase slightly at a given temperature and saturation state. The electrolyte effect on nucleation was proportional to the enhanced solubility of calcium sulfate dihydrate in ...

UK PubMed Central (United Kingdom)

Secondary caries and restoration fracture remain the two most common problems in restorative dentistry. Release of fluoride ions (F) could be a substantial benefit because F could enrich neighboring...Full Text Available

UK PubMed Central (United Kingdom)

The resistance to destruction of spores of Bacillus subtilis var. niger occluded in crystals of calcium carbonate and exposed to ethylene oxide and moist and dry heat...Full Text Available

UK PubMed Central (United Kingdom)

Measurements were made of ⁴⁵Ca influx into isolated internodal cells of Chara corallina and also into internodal cells of intact plants. ⁴⁵Ca influx was closely...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid.

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In the framework of the feasibility study of radioactive waste disposal in deep geologic formations, a clay formation (named 'argilite de l'Est') has been selected in the Meuse-Haute Marne region (France) for the construction of an underground laboratory. The percolation of alkaline solutions through the argilite has been studied using column experiments with short residence times (30 min). These experiments simulate the leaching of a cement which could be used in the building materials of the laboratory. The alkaline solutions used are mono-cationic solutions of calcium, sodium and strontium. The behaviour of calcium is differentiated from the other cations. For all alkaline solutions (NaOH, Ca(OH){sub 2} or Sr(OH){sub 2}) chemical reactions consuming both hydroxide ions and their associated cations have been evidenced. These reactions are heterogenous reactions of surface adsorption by site ionization. The ...

UK PubMed Central (United Kingdom)

Edema factor (EF) and CyaA are calmodulin (CaM)-activated adenylyl cyclase exotoxins involved in the pathogenesis of anthrax and whooping cough, respectively. Using spectroscopic, enzyme kinetic and...Full Text Available

UK PubMed Central (United Kingdom)

Segments of the chick basilar papilla were isolated and maintained in culture medium. The sensory hair bundle of individual hair cells was observed with light microscopy and stimulated with a water...Full Text Available

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Taiheiyo coal deashed using acid treatment and loaded with potassium or calcium was hydro-cracked under gaseous phase to discuss effects of these metals on liquefaction reaction. In addition, the loaded coal was added with red mud catalyst to examine effects of the addition. The loaded potassium has a softening power, and particularly the potassium adsorbed into surface and micropores in the coal decomposes selectively HI-BS and BI-PS and generates gas and HS. On the other hand, potassium deposited on coal surface promotes direct gas production from the coal. Irrespective of its loading modes, calcium has a catalytic nature to produce HI-BS selectively. Calcium also acts to impede decomposition of HI-BS into HS. Adding red mud catalyst to potassium loaded coal increases the inversion rate and the liquefaction yield, and most of the increase is accounted for by HI -BS, and BI-PS. When red mud catalyst is added to ...

UK PubMed Central (United Kingdom)

The amount of phosphorus contained in food as food additives is currently increasing and a high intake of phosphorus can cause various diseases. To determine the effects of a prolonged high phosphorus...Full Text Available

UK PubMed Central (United Kingdom)

Human Factor VIII/von Willebrand factor, purified by calcium citrate-cellulose chromatography and 4% agarose gel filtration was subjected to sodium dodecyl sulfate gel electrophoresis on gels containing...Full Text Available

UK PubMed Central (United Kingdom)

Plants respond to a large variety of environmental signals, including changes in the gravity vector (gravistimulation). In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation...Full Text Available

International Nuclear Information System (INIS)

Laboratory testing at Combustion Engineering has indicated promise in controlling simulated steam generator tube denting through chemical neutralization. Testing was limited to on-line treatment, and two neutralizers have been evaluated: calcium hydroxide and boric acid. On-line treatment with calcium hydroxide successfully halted active denting whenever the bulk calcium concentration (in ppm) equaled or exceeded the bulk chloride concentration (in ppm). Calcium hydroxide also was effective as an alternative to ammonia as a pH controlling agent in two tests conducted without ingress of chloride. On-line treatment with boric acid consisted of a four-day soak at simulated low (approximately 30 percent) power with 50 ppm B followed by one month full-power operation with 10 ppm B. This treatment also halted denting. Nondestructive and destructive examination of test boilers gave no indication of adverse ...

UK PubMed Central (United Kingdom)

1. Digital imaging and photometry were used in conjunction with the fluorescent Ca2+ indicator, Fura-2, to examine intracellular Ca2+ signals produced by depolarization of single adrenal chromaffin...Full Text Available

UK PubMed Central (United Kingdom)

Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability,...Full Text Available

UK PubMed Central (United Kingdom)

Although previous intravascular ultrasound (IVUS) radiofrequency-based analysis data showed acceptable reproducibility for plaque composition, measurements are not easily obtained, particularly that...Full Text Available

Science.gov (United States)

isotherme, dans un courant d'azote ou sous vide entretenu. I t. Comptes Rendus Scientific Academy, Paris, Vol. 265 pyrolyse du carbonate de calcium, ...

Science.gov (United States)

The parathyroid endocrine glands, usually four in number and about the size of a split pea, lie on either side of the posterior aspect of the thyroid gland. Occasionally one or more of these structures are found in an aberrant position in the neck or even in the superior mediastinum. The parathyroid secretion, parathormone, regulates the level of serum calcium within sharply defined limits. Lack of parathormone, with lowering of the serum calcium, results in hyper-irritability of skeletal muscle, the clinical condition known as tetany. This is encountered following inadvertent removal or bruising of the parathyroid glands at thyroidectomy. PMID:21488463

Energy Technology Data Exchange (ETDEWEB)

Air pollution constraints continue to intensify, resulting in solid waste volume increases. An example of this is coal burning power plant flue gas desulfurization by scrubbing. The aqueous suspensions of calcium sulfate hemihydrate or calcium sulfate dihydrate will exceed 200 million tons annually by the year 2000. Disposal of these wastes can have massive environmental effects, due to physical instability and leaching to groundwater. One alternate disposal technique is sulfopozzolanic fixation, converting the FGD waste by addition of fine coal ash and an alkaline earth additive, into a monolithic mass. 6 refs., 17 figs., 3 tabs.

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Calcium sulfate dihydrate in large crystal form is produced by maintaining the circulation of the lime containing scrubbing solution in the desulfurization scrubbing of flue gases from a power plant boiler so that it has a residence time of 5 to 25 hours, preferably 15 hours. The crystals are moved by passing a portion of the recirculation through a thinner in which a sludge containing crystals with a mean particle size of which 90% is in excess of 100 microns is removed. This product can be dewatered and treated with sulfuric acid and steam to convert it to the alpha semihydrate and is free from sulfite.

Energy Technology Data Exchange (ETDEWEB)

A heat storage compostion comprises sodium sulfate decahydrate as main component, a supercooling inhibitor, and a solid-liquid separation inhibitor. The composition is characterized in that hydraulic calcium sulfate and/or calcium sulfate dihydrate is contained as the solid-liquid separation inhibitor in an amount of 2-15 wt% base on the whole weight of the composition, whereby the solid-liquid separation, i.e. the sedimentation of the anhydrous sodium sulfate during the phase transition, is effectively prevented and the long-term stability is improved. The long-term stabilty of the composition can be more improved by addition of a silcia series of thickener.

Energy Technology Data Exchange (ETDEWEB)

The Danish Ministry of Transportation has prepared a national plan of transportation, for the years until 2005. Official policy concerning land, maritime and air transport, personal and cargo transportation, investments and expenditures is outlined. Environmental impacts of energy consumption and air pollution abatement measures are considered. (EG)

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Short communication. 2 figs.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Biological cells of the nitrogen fixating bacteria Xanthobacter autotrophicus GZ 29 have been cultivated with 57-Fe, and from the nitrogenase of these cells the 57-Fe marked molybdenum-iron-protein is extracted. The Moessbauer spectra of this enzyme show that the structure of the iron cluster is similar to the structure in the molybdenum-iron-proteins of Azotobacter vinelandii, Klebsiella pneumoniae or Clostridium pasteurianum.

KoreaScience (Korea)

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British Library Electronic Table of Contents (United Kingdom)

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a sing...

UK PubMed Central (United Kingdom)

Alterations in mass transport patterns of low-density lipoproteins (LDL) and oxygen are known to cause atherosclerosis in larger arteries. We hypothesise that the species transport processes in coronary...Full Text Available

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Transport of negative ion beams through plasma is reviewed. The effect of space charge on beam stability and beam emittance is discussed. The approaches to the beam transport problem developed at Los Alamos, Berkeley, Oak Ridge and Culham Laboratory are intercompared. (AIP)

UK PubMed Central (United Kingdom)

Citrate transport via CitS of Klebsiella pneumoniae has been shown to depend on the presence of Na+. This transport system has been expressed in Escherichia coli, and uptake of citrate in E. coli membrane...Full Text Available

UK PubMed Central (United Kingdom)

Amino acid transport was studied in membrane vesicles of the thermophilic anaerobic bacterium Clostridium fervidus. Neutral, acidic, and basic as well as aromatic amino acids were transported at 40...Full Text Available

CERN Document Server

This paper shows that a well designed transport system has an embedded exchange value by serving as a market for potential exchange between consumers. Under suitable conditions, one can improve the welfare of consumers in the system simply by allowing some exchange of goods between consumers during transportation without incurring additional transportation costs. We propose an explicit valuation formula to measure this exchange value for a given compatible transport system. This value is always nonnegative and bounded from above. Criteria based on transport structures, preferences and prices are provided to determine the existence of a positive exchange value. Finally, we study a new optimal transport problem with an objective taking into account of both transportation cost and exchange value.

UK PubMed Central (United Kingdom)

BackgroundABCA3 transporter (ATP-binding cassette transporter of the A subfamily) is localized to the limiting...Full Text Available

Science.gov (United States)

... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... ...

International Nuclear Information System (INIS)

Ten Holstein steers (579 kg average body weight) were fed either alfalfa hay (12.2% crude protein) or a 90% concentrate diet to supply 14.2 or 25.2 Mcal ME respectively for a minimum of 28 days. Samples of rumen epithelial tissue were removed at slaughter from the anterior ventral sac, washed free of feed particles and transported to the laboratory in oxygenated Krebs-Ringer bicarbonate buffer (KRB; pH 7.4). Papillae were weighed (100-200 mg) in triplicate into flasks containing 3 ml KRB with 1 mM glutamine or 5 mM glucose and acetate (50 mM), propionate (25 mM), butyrate (15 mM), lactate (1 mM) and glucose (5 mM) or glutamine (1 mM) as competing substrates. A parallel set of flasks contained 1 or .5 #mu#Ci of [U-"1"4C]-glutamine or glucose respectively for "1"4CO_2 production. There were no interactions with dietary energy intake and substrate addition. Increasing the dietary energy intake increased (P < .01) rates of uptake, "1"4CO_2 ...

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A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted-basement membrane cultures. These cells remained non-invasive; however, unlike their non-malignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including squamous and basal characteristics, with ...

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Cell extracts of the thermophile Clostridium thermohydrosulfuricum catalyzed the phosphorylation by (..gamma..-/sup 32/P)ATP of several endogenous proteins with M/sub r/s between 13,000 and 100,000. Serine and tyrosine were the main acceptors. Distinct substrate proteins were found in the soluble (e.g., proteins p66, p63, and p53 of M/sub r/s 66,000, 63,000, and 53,000, respectively) and particulate (p76 and p30) fractions, both of which contained protein kinase and phosphatase activity. The soluble fraction suppressed the phosphorylation of particulate proteins and contained a protein kinase inhibitor. Phosphorylation of p53 was promoted by 10..mu..M fructose 1,6-bisphosphate or glucose 1,6-bisphosphate and suppressed by hexose monophosphates, whereas p30 and p13 were suppressed by 5 ..mu..M brain (but not spinach) calmodulin. Polyamines, including the odd ...

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Metagenomics projects based on shotgun sequencing of populations of micro-organisms yield insight into protein families. We used sequence similarity clustering to explore proteins with a comprehensive dataset consisting of sequences from available databases together with 6.12 million proteins predicted from an assembly of 7.7 million Global Ocean Sampling (GOS) sequences. The GOS dataset covers nearly all known prokaryotic protein families. A total of 3,995 medium- and large-sized clusters consisting of only GOS sequences are identified, out of which 1,700 have no detectable homology to known families. The GOS-only clusters contain a higher than expected proportion of sequences of viral origin, thus reflecting a poor sampling of viral diversity until now. Protein domain distributions in the GOS dataset and current protein databases show distinct biases. Several ...

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Red light stimulates germination in the spores of Onoclea sensibilis L. Phytochrome is confirmed to be the photoreceptor pigment in the germination response by demonstrating red-far-red photoreversibility. External Ca/sup 2 +/ is required for this response with a threshold at a submicromolar concentration. Red light stimulates an increase in the total concentration of intracellular calcium in the spores as determined by atomic absorption spectroscopy. Subsequent exposure to far-red light inhibits the red light-induced increase in intracellular calcium. The majority of the increase occurs 5 minutes after the onset of irradiation. The calcium-antagonist, La/sup 3 +/ inhibits both germination and the red light-induced increase in intracellular calcium. Using /sup 31/P-nuclear magnetic resonance spectroscopy, the author tested the hypothesis that a sustained increase in intracellular pH contributes to the ...

British Library Electronic Table of Contents (United Kingdom)

Cocoon sericin plays an important role in the reeling of silk and serves as a valuable biomaterial in the field of biomedicine, skincare, and food industries; however, knowledge about cocoon sericin proteins has been limited. For a comprehensive study on sericin, cocoons of eight varieties of silkworm of different geographic origin and with varied cocoon color were analyzed utilizing proteomics and bioinformatics approaches. The electrophoresis pattern demonstrated some common protein bands for all silkworm varieties and distinctive protein bands for some of those examined in the present study. The Ser2 protein, a new Ser3 protein, and four other novel sericin proteins were identified in cocoons for the first time. Products of both Ser1 and Ser3 genes appear to be ubiquitous in the cocoon ...

British Library Electronic Table of Contents (United Kingdom)

This study was conducted to investigate the antibacterial effect of BSAP-254 on Bacillus cereus with the induced stress proteins. The BSAP-254 is an antimicrobial peptide isolated from soybean-fermenting bacteria, Bacillus subtilis SC-8. It had a narrow spectrum of activity against B. cereus group. The growth inhibitory effect of BSAP-254 (50??g/mL) reduced the population of B. cereus from >108 to 104 colony-forming units per milliliter within 30?min. In B. cereus exposed to BSAP-254, 14 intracellular proteins were differentially expressed as determined by 2-DE coupled with MS. Of the differentially expressed proteins identified, the stress protein GroEL, which is heat shock protein, was induced in B. cereus exposed to antibacterial peptide.

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A method to deduce the 2 x 2 transport matrix for coupled heat and particle transport in Tokamaks is proposed. The method applies to perturbative experiments, and is based on a Fourier transform of the measured signals of temperature and density. By analyzing different linear combinations of temperature and density, the eigenvectors and eigenvalues of the transport matrix are determined. The method is tested for a number of illustrative cases using simulated data, and the sensitivity to noise on the signals is evaluated. (author).

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Short communication.

KoreaScience (Korea)

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Science.gov (United States)

... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... ...

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No abstract prepared.

Science.gov (United States)

PMID:12324492

Energy Technology Data Exchange (ETDEWEB)

The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior in aqueous ...

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The paper gives results of a study to identify active sites and surface functional groups that may contribute to the absorption of elemental mercury (Hg) by relatively inexpensive calcium (Ca)-based sorbents. The study investigated the formation of chlorine (Cl) sites in CA-based sorbents as well as their role and reactivity in the absorption of Hg. HCl-exposed calcium sulfate dihydrate (gypsum) exhibited a superior Hg sorption capability. Crystalline water molecules on the surface of the gypsum were confirmed to contribute indirectly to Hg uptake. These surface molecules may have absorbed HC1 through hydrogen bond formation between an oxygen atom of a crystalline water molecule and a hydrogen atom of an HCl molecule. Two adjacent, physically absorbed HCl molecules could then trap an Hg molecule through formation of a mercuric-chloride-like molecule. Significant correlations between Cl and Hg uptake by gypsum were noted.

International Nuclear Information System (INIS)

Denting studies have been undertaken in order to assess the influence of the most important parameters which could initiate corrosion of the carbon-steel occurring in the tube-tube support plate crevices of some PWR steam generators. Tests have been carried out in model boilers, feedwater being polluted with sea or river water. Specific effect of chloride or sulfate and influence of oxygen content, magnetite addition and pH value were investigated. In magnetite prepacked crevices, denting is obtained within 1000 hours for sea-water pollution of 0.3 ppm chloride at the blowdown. In neutral chloride or in river water denting is observed only with oxygen addition. Denting prevention is effective in the case of an on-line addition of phosphate, boric acid or calcium hydroxide. For denting stopping, boric acid or calcium hydroxide is efficient even with a high sea-water pollution. Soaks cannot stop denting if they are not followed by an on-line ...

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This project is part of PETC`s Advanced Power Systems Program, whose mission is to accelerate the commercialization of affordable, high- efficiency, low emission, coal-fueled electric generating technologies. A process concept - Clear Liquor Scrubbing with Anhydrite Production - was proposed and accepted by PETC as a Phase I project in its Mega-PRDA program. the project integrated three process operations - chloride control upstream of the flue gas desulfurization (FGD) system, a clear liquor process for enhanced SO{sub 2} removal performance, and production of anhydrite (anhydrous calcium sulfate) rather than calcium sulfite or gypsum (calcium sulfate dihydrate). The first step in the project was to perform batch and flow-through experiments in the laboratory to confirm theoretical calculations and preliminary laboratory results concerning anhydrite formation, these laboratory experiments were designed to prove that ...

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A method and an instrument for determining the total water content in a hydrocarbon fuel using an indicator composition, which includes calcium hydride and phenolphthaleyn, are developed. The essence of the method is fixing the presence of water with its interaction with the calcium hydride and subsequent indication of the formed Ca(OH)2 using the phenolphthallen. To make the indicator composition, a hygroscopic cotton, prewashed by rectified alcohol and dried for 30 minutes at 105 degrees, is impregnated by a 1 percent alcohol solution of phenolphthaleyn and is dried in the same conditions. Then the cotton is processed by a powder form calcium hydride (a layer thickness of 0.1 to 0.2 millimeters, and a granule size of less than or equal to 80 micromters). The indicator composition is placed in a glass tube (a diameter of 4 to 7 millimeters and a length of 80 to 100 millimeters), whose ends are sealed or filled with ...

Science.gov (United States)

In drug development, Caco-2 cells are often employed to study the influence of membrane transporters on drug permeability. The aim of the current study was to characterize permeability and kinetic parameters of selected organic anionic compounds in Caco-2 cells, and to investigate whether the Caco-2 cell line may be used as an overall model to predict interactions on multiple membrane transporters in the intestine. Taurocholic acid (TCA) and estrone-3-sulfate (E(1) S) were used as model substrates. Possible inhibitors studied were TCA, E(1) S, taurolithocholic acid, fluvastatin, and glipizide. The effects of these compounds on initial uptake, apparent permeability, and intracellular end-point accumulations of the probe substrates were studied. Both interactions on apical and basolateral influx transporters were observed. These interactions were proposed to be mediated mainly by the apical sodium-dependent bile acid ...

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Solenoid transport of high current, heavy ion beams is considered for several stages of a heavy ion fusion driver. In general this option is more efficient than magnetic quadrupole transport at sufficiently low kinetic energy and/or large e/m, and for this reason it has been employed in electron induction linacs. Ideally an ion beam would be transported in a state of Brillouin flow, i.e. cold in the transverse plane and spinning at one half the cyclotron frequency. The design of appropriate solenoids and the equilibrium and stability of transported ion beams are discussed. An outline of application to a fusion driver is also presented.

UK PubMed Central (United Kingdom)

Werner syndrome (WS) is characterized by premature onset of age-associated disorders and predisposition to cancer. The WS protein, WRN, encodes 3′ → 5′ DNA helicase and 3′...Full Text Available

UK PubMed Central (United Kingdom)

Effector proteins expressed in the esophageal gland cells of cyst nematodes are delivered into plant cells through a hollow, protrusible stylet. Although evidence indicates that effector proteins function...Full Text Available

UK PubMed Central (United Kingdom)

Amidination of aldolase, glyceraldehyde-3-phosphate dehydrogenase, tryptophan synthetase B protein, L-arabinose isomerase, and the catalytic subunit of E. coli aspartate transcarbamylase...Full Text Available

UK PubMed Central (United Kingdom)

The mini-chromosome maintenance proteins Mcm2–7 are essential for DNA replication. They are loaded onto replication origins during G1 phase of the cell cycle to form a pre-replication complex...Full Text Available

UK PubMed Central (United Kingdom)

Altered structure, and hence function, of cellular macromolecules caused by oxidation can contribute to loss of physiological function with age. Here, we tested whether the lifespan of bats, which generally...Full Text Available

UK PubMed Central (United Kingdom)

Previous studies have shown that salicylates and protein-calorie malnutrition independently compromise maturation and growth of infants. In the present study, pregnant rats were fed normal-and low-protein...Full Text Available

UK PubMed Central (United Kingdom)

Surfactant protein A (SP-A), first identified as a component of the lung surfactant system, is now recognized to be an important contributor to host defence mechanisms. SP-A can facilitate phagocytosis...Full Text Available

UK PubMed Central (United Kingdom)

The e.p.r. spectra of the Fe-proteins of nitrogenase from all sources studied have unusual features in that they have very anisotropic linewidths and low integrated intensities. These characteristics...Full Text Available