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Sample records for beta rays biological effects

  1. Indirect radio-chemo-beta therapy: a targeted approach to increase biological efficiency of x-rays based on energy.

    Science.gov (United States)

    Oktaria, Sianne; Corde, Stéphanie; Lerch, Michael L F; Konstantinov, Konstantin; Rosenfeld, Anatoly B; Tehei, Moeava

    2015-10-21

    Despite the use of multimodal treatments incorporating surgery, chemotherapy and radiotherapy, local control of gliomas remains a major challenge. The potential of a new treatment approach called indirect radio-chemo-beta therapy using the synergy created by combining methotrexate (MTX) with bromodeoxyuridine (BrUdR) under optimum energy x-ray irradiation is assessed. 9L rat gliosarcoma cells pre-treated with 0.01 μM MTX and/or 10 μM BrUdR were irradiated in vitro with 50 kVp, 125 kVp, 250 kVp, 6 MV and 10 MV x-rays. The cytotoxicity was assessed using clonogenic survival as the radiobiological endpoint. The photon energy with maximum effect was determined using radiation sensitization enhancement factors at 10% clonogenic survival (SER10%). The cell cycle distribution was investigated using flow cytometric analysis with propidium iodide staining. Incorporation of BrUdR in the DNA was detected by the fluorescence of labelled anti-BrUdR antibodies. The radiation sensitization enhancement exhibits energy dependence with a maximum of 2.3 at 125 kVp for the combined drug treated cells. At this energy, the shape of the clonogenic survival curve of the pharmacological agents treated cells changes substantially. This change is interpreted as an increased lethality of the local radiation environment and is attributed to supplemented inhibition of DNA repair. Radiation induced chemo-beta therapy was demonstrated in vitro by the targeted activation of combined pharmacological agents with optimized energy tuning of x-ray beams on 9 L cells. Our results show that this is a highly effective form of chemo-radiation therapy.

  2. Effect on pancreatic beta cells and nerve cells by low let x-ray

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwang Hun [Dept. of Nuclear Medicine, Kyungbuk National University Hospital, Daegu (Korea, Republic of); Kim, Kgu Hwan [Dept. of Radiological Technology, Daegu health College, Daegu (Korea, Republic of)

    2014-03-15

    Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia condition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

  3. {beta}-ray irradiation effects in RbBr: Eu crystals

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco B, J.M.; Rodriguez M, R.; Perez S, R. [Universidad de Sonora, 83190 hermosillo, Sonora (Mexico)

    2006-07-01

    Defects induced by {beta}-ray irradiation in RbBr: Eu{sup 2+} crystals doped with a high concentration of Eu{sup 2+} ions are studied by means of optical absorption (OA), thermoluminescence (TL), and optically stimulated TL (OSTL). The fading, dose, and optical bleaching effects on the TL glow curves of room temperature irradiated samples has been analyzed. OA indicates that irradiation of samples at room temperature induce the formation of F but not F{sub z} centers. The TL glow curves show peaks at 267, 303, and 403 K. The 267 K glow peak disappear in less than 1 s under blue light or infrared radiation photo bleaching. A high sensitivity to the ionizing radiation has been observed. These results confirm that this material is an efficient phosphor. (Author)

  4. The biological effect and medical functions of the Infrared Rays

    Institute of Scientific and Technical Information of China (English)

    PANG Xiao-feng

    2001-01-01

    The quantum vibrational energy-spectra including high excited states of the protein molecules have been calculated by new theory of bio-energy transport along the protein molecules and its dynamic equation, discrete nonlinear Schrodinger equation, appropriate to the protein molecules on the basis of the level of molecular structure. This energy-spectra obtained are basically consistent with the experimental values by infrared absorption and radiated measurement of person's hands and laser-Raman spectrum from metabolically active E. Coli.. From this energy-spectra we know that the infrared lights with (1-3)x1000nm and (5-7)x1000nm wavelength can be absorbed by the protein molecules in the living systems.In accordance with the non-linear theory of the bio-energy transport we know that the energy of the infrared light absorbed by the proteins can result in vibrations of amide-I in amino acids and can facilitate the bio-energy transport along the protein molecular chains from one place to other for the growth of living bodies. This processe is non-thermal. This is just non-thermal effect of the infrared lights. According to the mechanism we explained further the medical functions of the infrared lights absorbed.

  5. Biological Effects of Gamma-Ray Bursts: Critical distances for severe damage on the biota

    CERN Document Server

    Galante, D; Galante, Douglas; Horvath, Jorge Ernesto

    2005-01-01

    We present in this work a unified, quantitative synthesis of analytical and numerical calculations of the effects caused on an Earth-like planet by a Gamma-Ray Burst (GRB), considering atmospheric and biological implications. The main effects of the illumination by a GRB are classified in four distinct ones and analyzed separately, namely the direct gamma radiation transmission, UV flash, ozone layer depletion and cosmic rays. The effectiveness of each of these effects is compared and lethal distances for significant biological damage are given for each one. We find that the first three effects have potential to cause global environmental changes and biospheric damages, even if the source is located at great distances (perhaps up to ~ 100 kpc). Instead, cosmic rays would only be a serious threat for very close sources. As a concrete example of a recorded similar event, the effects of the giant flare from SGR1806-20 of Dec 27, 2004 could cause on the biosphere are addressed. In spite of not belonging to the so...

  6. Calculation of {beta}-ray spectra. Odd-odd nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Takahiro [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1996-05-01

    In order to study {beta}-ray of atomic nucleus, it is natural to consider {beta}-ray data fundamental and important. In a recent experiment, Rudstam measured {beta}-ray spectra from short term nuclear fission product species in 1990. It is an important check point in theoretical study on {beta}-ray to investigate if these experimental data can be reproduced by any theoretical calculation. As there are several spectrum studies of {beta}-ray through decay heat for its various properties due to the general theory of the {beta}-decay, little descriptions can be found. In even such studies, spectra under high excitation state of daughter species difficult to measure and apt to short experimental results were treated with combination spectra composed of experimental and calculated values such as substitution of a part of the general theory with calculated value. In this paper, the {beta} spectra supposed by only the general theory was reported without using such data combination in order to confirm effectiveness of the theory. In particular, this report was described mainly on the results using recent modification of odd-odd nucleus species. (G.K.)

  7. Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends

    Science.gov (United States)

    Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

    2011-01-01

    X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

  8. High energy beta rays and vectors of Bilharzia and Fasciola

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, J.J.; Akpa, T.C.; Dim, L.A.; Ogunsusi, R.

    1988-01-01

    Preliminary investigations of the effects of high energy beta rays on Lymnea natalensis, the snail vector of Schistosoma haematobium have been conducted. Results show that in both stream and tap water, about 70% of the snails die when irradiated for up to 18 hours using a 15m Ci Sr-90 beta source. The rest of the snails die without further irradiation in 24 hours. It may then be possible to control the vectors of Bilharzia and Fasciola by using both the direct and indirect effects of high energy betas.

  9. The effect of the beta-emitting yttrium-90 citrate on the dose-response of dicentric chromosomes in human lymphocytes: a basis for biological dosimetry after radiosynoviorthesis.

    Science.gov (United States)

    Schmid, E; Selbach, H-J; Voth, M; Pinkert, J; Gildehaus, F J; Klett, R; Haney, M

    2006-07-01

    The production of dicentric chromosomes in human lymphocytes by beta-particles of yttrium-90 (Y-90) was studied in vitro to provide a basis of biological dosimetry after radiosynoviorthesis (RSO) of persistent synovitis by intra-articular administration of yttrium-90 citrate colloid. Since the injected colloid may leak into the lymphatic drainage exposing other parts of the body to radiation, the measurement of biological damage induced by beta-particles of Y-90 is important for the assessment of radiation risk to the patients. A linear dose-response relationship (alpha = 0.0229 +/- 0.0028 dicentric chromosomes per cell per gray) was found over the dose range of 0.2176-2.176 Gy. The absorbed doses were calculated for exposure of blood samples to Y-90 activities from 40 to 400 kBq using both Monte Carlo simulation and an analytical model. The maximum low-dose RBE, the RBE(M) which is equivalent to the ratio of the alpha coefficients of the dose-response curves, is well in line with published results obtained earlier for irradiation of blood of the same donor with heavily filtered 220 kV X-rays (3.35 mm copper), but half of the RBE(M) relative to weakly filtered 220 kV X-rays. Therefore, it can be concluded that for estimating an absorbed dose during RSO by the technique of biological dosimetry, in vitro and in vivo data for the same radiation quality are necessary.

  10. Effect of irradiation (gamma rays) on the biology of Eimeria tenella oocysts

    Energy Technology Data Exchange (ETDEWEB)

    Bajwa, R.S.; Gill, B.S.

    1977-01-01

    Effect of gamma rays on the biology of the progeny of the irradiated Eimeria tenella oocysts was investigated. The parent inoculum of sporulated oocysts was exposed to 5 to 60 kR (gamma rays). These oocysts were fed to chicks. The oocysts voided by the chicks were collected and sporulated. The sporulation rate, pathogenicity, immunogenicity and reproduction potential of these oocysts--the progeny of the irradiated oocysts--were compared with those of the unirradiated oocysts. It was observed that increase of irradiation dose caused progressive decrease in the pathogenicity of the oocyst suspension. The oocysts exposed to 30 and 40 kR produced only mild infections whereas those exposed to 50 kR and above were noninfective. No difference in pathogenicity, immunogenicity and reproduction potential of unirradiated oocysts and the oocysts progeny of the irradiated oocysts was seen. It was concluded, therefore, that the effect of irradiation was limited to the inoculum exposed to it, and was not transmissible to the progeny of the irradiated oocysts.

  11. Gamma rays as an effective tool for removing undesirable color without adverse changes in biological activities of red beet extracts

    Science.gov (United States)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung-Woo; Lee, In Chul; Chung, Byung Yeoup

    2012-08-01

    The ethanolic extracts of red beet (Beta vulgaris L.) hairy root were used to investigate the removal of color and improvement of biological activity for enhanced industrial applications. The extracts were exposed to gamma rays ranging from 2.5 to 30 kGy. The red beet hairy root is composed of two major red-colorants, betanin and isobetanin. Gamma ray radiation at 5 kGy remarkably reduced the levels of the major colorants by 94% and the reddish color was eliminated by doses greater than 10 kGy. Color removal was likely due to the gamma ray radiolysis of ethanol. Although details on the mechanism responsible for the decay of the chromophore have not been entirely determined, our results suggest that the free radicals that are produced during this process are capable of destroying the chromophore group in isobetanin, thus bleaching the substrate solution. In spite of the degradation of the major colorants, the biological activities of constituents of the extract such as DPPH radical scavenging and tyrosinase inhibition were negligibly affected by the gamma ray radiation up to 20 kGy. The antioxidant activity was 92.7% in control samples and 90.0-92.0% in irradiated samples (2.5-20 kGy), and a slight decrease to 87.5% was observed for gamma ray radiation at 30 kGy. In addition, tyrosinase inhibition activity has also the same pattern; the activity is slightly increased from 50.7% of control to 49.1-52.8% of irradiated samples (2.5-20 kGy) with a 46.8% at 30 kGy.

  12. Scintillation spectroscopy for beta ray dose measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vapirev, E.I.; Jordanov, T.; Amin, S.; Stoilov, N.; Georgieva, K. [Sofia Univ. (Bulgaria). Fizicheski Fakultet

    1996-11-01

    Two methods have been developed and tested for the measurement of beta ray dose with a scintillation probe. According to the first method the energy absorbed in plastic filters is calculated from the difference between the energy E of the incident and filtered beta spectrum with an expression of the type E {approx} c{Sigma}iN(i)/{Delta}m, where c is a calibration constant (keV per channel), i is the channel number, N(i) is the detected beta spectrum, and {Delta}m is the filter thickness. According to the second `dE/dx` method the energy deposited in the surface layer of the scintillator is calculated by E {approx} c{Sigma}dE/dx(i)N(i), where dE/dx is the specific energy loss for tissue-equivalent media. The methods were tested for the cases of normally incident electrons and surface contamination. The scintillation probe used is stillbene and the test sources are thin {sup 90}Sr/{sup 90}Y and {sup 137}Cs. The results are close to the expected doses as calculated by Monte Carlo simulations. (Author).

  13. Effect of Stacking Faults on the X-Ray Diffraction Profiles of Beta-SiC Powders

    Science.gov (United States)

    Pujar, Vijay V.; Cawley, James D.; Levine, Stanley R. (Technical Monitor)

    1995-01-01

    X-ray diffraction patterns or beta-SiC (3C or the cubic polytype or sic) powders often exhibit an additional peak at d = 0.266 nm, high background intensity around the (111) peak, and relative intensities for peaks which differ from those predicted from the crystal structure. Computer simulations were used to show that all these features are due to stacking faults in the powders and not due to the presence of other polytypes in the powders. Such simulations allow diffraction patterns to be generated for different types, frequencies, and spatial distribution or faults. Comparison of the simulation results to the XRD data indicates that the B-SiC particles consist either of heavily faulted clusters distributed irregularly between regions that have only occasional faults or twins, or the powders consist of two types of particles with different populations of faults: those with a high density of faults and those with only twins or occasional faults. Additional information is necessary to determine which description is correct. However, the simulation results can be used to rule out certain fault configurations.

  14. Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2); [beta]-ray counting

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Tadashi; Furuta, Masakazu; Shibata, Setsuko; Matsunami, Tadao; Ito, Norio; Mizohata, Akira; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1994-02-01

    In order to check radioactivity of beta-emmitters produced by ([gamma], n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2[pi] gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the [beta]-activities were detected. From the amount of observed radioactivities of [beta]-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from [sup 40]K contained in the samples and, hence, its biological effects should be negligible. (author).

  15. Backscatter radiation at tissue-titanium interfaces; Biological effects from diagnostic 65 kVp X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Rosengren, B. (Department of Radiation Sciences, Uppsala University (Sweden) Dept. of Oncology, University Hospital, Bergen (Norway)); Wulff, L. (Dept. of Oral and Maxillofacial Surgery, Central Hospital, Boden (Sweden)); Carlsson, E. (Department of Radiation Sciences, Uppsala University (Sweden)); Carlsson, J. (Department of Radiation Sciences, Uppsala University (Sweden)); Strid, K.G. (Dept. of Handicap Research, Goeteborg Univ. (Sweden)); Montelius, A. (Dept. of Hospital Physics, University Hospital, Uppsala (Sweden))

    1993-01-01

    The induced secondary electrons from a metal surface by diagnostic X-rays are thought to contribute to cell damage near the tissue-metal boundaries of metal implants. Titanium implants are becoming increasingly more popular for tissue reconstructions and it is rather often desirable to take radiographs of the operated area. In this study we compared the biological effects of radiation on cultured mammalian test cells grown on titanium plates with the radiation effects on cells that were grown on plastic control plates. In order to study the acute radiation effects on cell growth it was necessary to work with rather high radiation doses (0.7-5 Gy). Photon energies, suitable for diagnostic radiography in odontology, 65 kV, were applied. We found that the cells grown on titanium plates were, in terms of the applied dose in the surrounding culture medium, more sensitive to the irradiations than the cells growing on plastic plates. The survival curve for the cells on titanium had a steeper slope, showed no shoulder in the low-dose region and looked like curves normally obtained for high LET radiation. It was not possible to resolve to what degree the titanium-dependent changes were due to an increased dose near the titanium surface or to a change in the radiobiological effectiveness. Although there was a significant decrease in cellular survival near the metal, postoperative intraoral radiography after titanium implantations need not be excluded. The maximal doses given in odontological X-ray examinations are less than 1 mGy and, if the results in this study are applied, the biological effects near the titanium implant will correspond to biological effects in soft tissue of doses less than 20 mGy which is lower than the doses that give acute effects. The risk of acute healing disturbances are significant only at much higher radiation doses. (orig.).

  16. OPTIMAL BETA-RAY SHIELDING THICKNESSES FOR DIFFERENT THERAPEUTIC RADIONUCLIDES AND SHIELDING MATERIALS.

    Science.gov (United States)

    Cho, Yong In; Kim, Ja Mee; Kim, Jung Hoon

    2016-04-06

    To better understand the distribution of deposited energy of beta and gamma rays according to changes in shielding materials and thicknesses when radionuclides are used for therapeutic nuclear medicine, a simulation was conducted. The results showed that due to the physical characteristics of each therapeutic radionuclide, the thicknesses of shielding materials at which beta-ray shielding takes place varied. Additional analysis of the shielding of gamma ray was conducted for radionuclides that emit both beta and gamma rays simultaneously with results showing shielding effects proportional to the atomic number and density of the shielding materials. Also, analysis of bremsstrahlung emission after beta-ray interactions in the simulation revealed that the occurrence of bremsstrahlung was relatively lower than theoretically calculated and varied depending on different radionuclides.

  17. Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic and Biogeochemical Effects

    CERN Document Server

    Thomas, B C; Jackman, C H; Laird, C M; Medvedev, M V; Stolarski, R S; Gehrels, N; Cannizzo, J K; Hogan, D P; Ejzak, L M; Thomas, Brian C.; Melott, Adrian L.; Jackman, Charles H.; Laird, Claude M.; Medvedev, Mikhail V.; Stolarski, Richard S.; Gehrels, Neil; Cannizzo, John K.; Hogan, Daniel P.; Ejzak, Larissa M.

    2005-01-01

    Gamma-Ray Bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to $\\mathrm{NO_2}$ opacity, and deposition of nitrates through rainout of $\\mathrm{HNO_3}$. For the ``typical'' nearest burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 years after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. We find DNA damage of up to 16 times the normal annual global average, well above lethal levels for simple life forms such as phytopl...

  18. X-ray microtomography in biology

    CERN Document Server

    Mizutani, Ryuta

    2016-01-01

    Progress in high-resolution x-ray microtomography has provided us with a practical approach to determining three-dimensional (3D) structures of opaque samples at micrometer to submicrometer resolution. In this review, we give an introduction to hard x-ray microtomography and its application to the visualization of 3D structures of biological soft tissues. Practical aspects of sample preparation, handling, data collection, 3D reconstruction, and structure analysis are described. Furthermore, different sample contrasting methods are approached in detail. Examples of microtomographic studies are overviewed to present an outline of biological applications of x-ray microtomography. We also provide perspectives of biological microtomography as the convergence of sciences in x-ray optics, biology, and structural analysis.

  19. Effects of indirect actions and oxygen on relative biological effectiveness: estimate of DSB induction and conversion induced by gamma rays and helium ions.

    Science.gov (United States)

    Tsai, Ju-Ying; Chen, Fang-Hsin; Hsieh, Tsung-Yu; Hsiao, Ya-Yun

    2015-07-01

    Clustered DNA damage other than double-strand breaks (DSBs) can be detrimental to cells and can lead to mutagenesis or cell death. In addition to DSBs induced by ionizing radiation, misrepair of non-DSB clustered damage contributes extra DSBs converted from DNA misrepair via pathways for base excision repair and nucleotide excision repair. This study aimed to quantify the relative biological effectiveness (RBE) when DSB induction and conversion from non-DSB clustered damage misrepair were used as biological endpoints. The results showed that both linear energy transfer (LET) and indirect action had a strong impact on the yields for DSB induction and conversion. RBE values for DSB induction and maximum DSB conversion of helium ions (LET = 120 keV/μm) to (60)Co gamma rays were 3.0 and 3.2, respectively. These RBE values increased to 5.8 and 5.6 in the absence of interference of indirect action initiated by addition of 2-M dimethylsulfoxide. DSB conversion was ∼1-4% of the total non-DSB damage due to gamma rays, which was lower than the 10% estimate by experimental measurement. Five to twenty percent of total non-DSB damage due to helium ions was converted into DSBs. Hence, it may be possible to increase the yields of DSBs in cancerous cells through DNA repair pathways, ultimately enhancing cell killing.

  20. X-ray scattering signatures of {beta}-thalassemia

    Energy Technology Data Exchange (ETDEWEB)

    Desouky, Omar S. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT) (Egypt); Elshemey, Wael M. [Biophysics Department, Faculty of Science, Cairo University (Egypt)], E-mail: waelelshemey@yahoo.com; Selim, Nabila S. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT) (Egypt)

    2009-08-11

    X-ray scattering from lyophilized proteins or protein-rich samples is characterized by the presence of two characteristic broad peaks at scattering angles equivalent to momentum transfer values of 0.27 and 0.6 nm{sup -1}, respectively. These peaks arise from the interference of coherently scattered photons. Once the conformation of a protein is changed, these two peaks reflect such change with considerable sensitivity. The present work examines the possibility of characterizing the most common cause of hemolytic anaemia in Egypt and many Mediterranean countries; {beta}-thalassemia, from its X-ray scattering profile. This disease emerges from a genetic defect causing reduced rate in the synthesis of one of the globin chains that make up hemoglobin. As a result, structurally abnormal hemoglobin molecules are formed. In order to detect such molecular disorder, hemoglobin samples of {beta}-thalassemia patients are collected, lyophilized and measured using a conventional X-ray diffractometer. Results show significant differences in the X-ray scattering profiles of most of the diseased samples compared to control. The shape of the first scattering peak at 0.27 nm{sup -1}, in addition to the relative intensity of the first to the second scattering peaks, provides the most reliable signs of abnormality in diseased samples. The results are interpreted and confirmed with the aid of Fourier Transform Infrared (FTIR) spectroscopy of normal and thalassemia samples.

  1. Breakthrough disease during interferon-[beta] therapy in MS: No signs of impaired biologic response

    DEFF Research Database (Denmark)

    Hesse, D; Krakauer, M; Lund, H;

    2010-01-01

    Disease activity is highly variable in patients with multiple sclerosis (MS), both untreated and during interferon (IFN)-beta therapy. Breakthrough disease is often regarded as treatment failure; however, apart from neutralizing antibodies (NAbs), no blood biomarkers have been established...... as reliable indicators of treatment response, despite substantial, biologically measurable effects. We studied the biologic response to treatment in a cohort of NAb-negative patients to test whether difference in responsiveness could segregate patients with and without breakthrough disease during therapy....

  2. Comparison of DSB effects of the beta particles of iodine-131 and 6 MV X-ray at a dose of 2 Gy in the presence of 2-Methoxyestradiol, IUdR, and TPT in glioblastoma spheroids

    Science.gov (United States)

    Neshasteh-Riz, Ali; Eyvazzadeh, Nazila; Koosha, Fereshteh; Cheraghi, Susan

    2017-02-01

    Glioblastoma is one of the lethal brain tumors and one of the resistant tumors against radiotherapy. Multiple treatment methods and different types of radiation and Radiosensitizers drugs have been combined to optimize the efficacy of radiotherapy. Radiosensitizers are employed to reinforce tumor cell killing and have much fewer effects on the normal tissue. Inducing DNA double strand break in tumoral cells is a major goal of radiation sensitivity. In this study, the level of DNA double strand break in glioblastoma spheroids irradiated by 2 Gy beta particles of iodine-131 and 6 MV X-rays in the presence of 2-Methoxyestradiol (2ME2), iodo-deoxy-uridine (IUdR) and Topotecan (TPT) was measured using the PicoGreen method. Spheroids of the U87MG cell line were cultured to reach a 300 μm diameter. In the phase one of the study, the spheroids were treated in four groups individually, including 2 Gy of iodine-131, TPT+iodine-131, IUdR+iodine-131, IUdR+2ME2+iodine-131. In the next phase, the cells were treated with 2 Gy of 6 MV X-ray, TPT+6 MV X-ray, IUdR+6 MV X-ray, TPT+IUdR+6 MV X-ray. DSB lesions were measured by the Pico Green assay. The amount of DSB lesions in groups irradiated with iodine-131 individually was greater than the group irradiated with 6 MV X-ray (p0.05). The level of DNA double strand breaks in cells irradiated with Iodine-131 was higher than cells irradiated with 6 MV X-ray at the same dose and Topotecan had a positive effect on inducing the damage. The role of 2ME2+IUdR in increasing the damage caused by beta particles of iodine-131 was not significant. Iodine-131 could lead to major DSB damage than 6 MV X-ray at the same dose due to its cross fire effect and spatial distribution of energy in different angels. This study showed that a combination of chemotherapy and iodine-131 had better efficacy than radiotherapy with 6 MV X-ray in the treatment of glioblastoma.

  3. Reproductive biology of cuckoo ray Leucoraja naevus.

    Science.gov (United States)

    Maia, C; Erzini, K; Serra-Pereira, B; Figueiredo, I

    2012-09-01

    The present study is the first to provide data on the reproductive biology of cuckoo ray Leucoraja naevus in Portuguese continental waters. No difference in size at maturity was detected between sexes, which was estimated as 56 cm total length. Spawning occurs all year round, but maximum activity was during winter months. Maximum fecundity is c. 63 eggs female(-1) year(-1). Encapsulated eggs are released in batches, nine in total with a mean number of seven extruded eggs in each batch.

  4. Comparison of the biological effectiveness of 45 MeV C-ions and γ-rays in inducing early and late effects in normal human primary fibroblasts

    Science.gov (United States)

    Fratini, E.; Balduzzi, M.; Antonelli, F.; Sorrentino, E.; Esposito, G.; Cuttone, G.; Romano, F.; Dini, V.; Simone, G.; Belli, M.; Campa, A.; Tabocchini, M. A.

    2013-07-01

    Investigation of the mechanisms underlying the biological effects induced by densely ionizing radiation has relevant implications in both radiation protection and therapy. In particular, the possible advantages of hadrontherapy with respect to conventional radiotherapy in terms of high conformal tumor treatment and sparing of healthy tissues are well known. Further improvements are limited by lack of radiobiological knowledge, particularly about the specific cellular response to the damage induced by particles of potential interest for tumor treatment. This study compares early and late effects induced in AG01522 normal human primary fibroblasts by γ-rays and C-ions having E ˜ 45 MeV/u at the cell entrance, corresponding to LET (in water) ˜ 49 keV/μm. Different end points have been investigated, namely: cell killing and lethal mutation, evaluated as early and delayed reproductive cell death, respectively; chromosome damage, as measured by micronuclei induction (MN); DNA damage, in terms of DSB induction and repair, as measured by the H2AX phosphorylation/dephosphorylation kinetics. Linear dose-response relationships were found for cell killing and induction of lethal mutations, with RBEs of about 1.3 and 1.6 respectively, indicating that the presence of genomic instability is greater in the progeny of C-ions irradiated cells. H2AX phosphorylation/dephosphorylation kinetics have shown a maximum foci number at 30 min after irradiation, higher for γ-rays than for C-ions. However, in the first 12 h the fraction of residual γ-H2AX foci was higher for C-ions irradiated cells, indicating a lower removal rate, possibly related to multiple/more complex damage along the particle track, with respect to the sparse lesions produced by γ-rays. MN induction, observed after 72 h from irradiation, was also greater for C-ions. Overall, these data indicate a more severe DNA damage induced by 45 MeV/u C-ions with respect to γ-rays, likely responsible of an increased cellular

  5. Comparison of the biological effectiveness of 45 MeV C-ions and {gamma}-rays in inducing early and late effects in normal human primary fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Fratini, E. [Centro studi e ricerche e museo storico della fisica E. Fermi, Roma (Italy); Balduzzi, M. [ENEA, Roma, Italy and INFN, Sezione Roma1-Gruppo Collegato Sanita, Roma (Italy); Antonelli, F.; Sorrentino, E.; Esposito, G. [Istituto Superiore di Sanita, Roma, Italy and INFN, Sezione Roma1-Gruppo Collegato Sanita, Roma (Italy); Cuttone, G.; Romano, F. [INFN-LNS, Catania (Italy); Dini, V.; Simone, G.; Campa, A.; Tabocchini, M. A. [stituto Superiore di Sanita, Roma, Italy and INFN, Sezione Roma1-Gruppo Collegato Sanita, Roma (Italy); Belli, M. [INFN, Sezione Roma1-Gruppo Collegato Sanita, Roma (Italy)

    2013-07-18

    Investigation of the mechanisms underlying the biological effects induced by densely ionizing radiation has relevant implications in both radiation protection and therapy. In particular, the possible advantages of hadrontherapy with respect to conventional radiotherapy in terms of high conformal tumor treatment and sparing of healthy tissues are well known. Further improvements are limited by lack of radiobiological knowledge, particularly about the specific cellular response to the damage induced by particles of potential interest for tumor treatment. This study compares early and late effects induced in AG01522 normal human primary fibroblasts by {gamma}-rays and C-ions having E {approx} 45 MeV/u at the cell entrance, corresponding to LET (in water) {approx} 49 keV/{mu}m. Different end points have been investigated, namely: cell killing and lethal mutation, evaluated as early and delayed reproductive cell death, respectively; chromosome damage, as measured by micronuclei induction (MN); DNA damage, in terms of DSB induction and repair, as measured by the H2AX phosphorylation/dephosphorylation kinetics. Linear dose-response relationships were found for cell killing and induction of lethal mutations, with RBEs of about 1.3 and 1.6 respectively, indicating that the presence of genomic instability is greater in the progeny of C-ions irradiated cells. H2AX phosphorylation/dephosphorylation kinetics have shown a maximum foci number at 30 min after irradiation, higher for {gamma}-rays than for C-ions. However, in the first 12 h the fraction of residual {gamma}-H2AX foci was higher for C-ions irradiated cells, indicating a lower removal rate, possibly related to multiple/more complex damage along the particle track, with respect to the sparse lesions produced by {gamma}-rays. MN induction, observed after 72 h from irradiation, was also greater for C-ions. Overall, these data indicate a more severe DNA damage induced by 45 MeV/u C-ions with respect to {gamma}-rays, likely

  6. Cu K-edge X-ray Absorption Spectroscopy Reveals Differential Copper Coordimation Within Amyloid-beta Oligomers Compared to Amyloid-beta Monomers

    Energy Technology Data Exchange (ETDEWEB)

    J Shearer; P Callan; T Tran; V Szalai

    2011-12-31

    The fatal neurodegenerative disorder Alzheimer's disease (AD) has been linked to the formation of soluble neurotoxic oligomers of amyloid-{beta} (A{beta}) peptides. These peptides have high affinities for copper cations. Despite their potential importance in AD neurodegeneration few studies have focused on probing the Cu{sup 2+/1+} coordination environment within A{beta} oligomers. Herein we present a Cu K-edge X-ray absorption spectroscopic study probing the copper-coordination environment within oligomers of A{beta}(42) (sequence: DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA). We find that the Cu{sup 2+} cation is contained within a square planar mixed N/O ligand environment within A{beta}(42) oligomers, which is similar to the copper coordination environment of the monomeric forms of {l_brace}Cu{sup II}A{beta}(40){r_brace} and {l_brace}Cu{sup II}A{beta}(16){r_brace}. Reduction of the Cu{sup 2+} cation within the A{beta}(42) oligomers to Cu{sup 1+} yields a highly dioxygen sensitive copper-species that contains Cu{sup 1+} in a tetrahedral coordination geometry. This can be contrasted with monomers of {l_brace}Cu{sup I}A{beta}(40){r_brace} and {l_brace}Cu{sup I}A{beta}(16){r_brace}, which contain copper in a dioxygen inert linear bis-histidine ligand environment [Shearer and Szalai, J. Am. Chem. Soc., 2008, 130, 17826]. The biological implications of these findings are discussed.

  7. Structural and biological mimicry of protein surface recognition by [alpha/beta]-peptide foldamers

    Energy Technology Data Exchange (ETDEWEB)

    Horne, W. Seth; Johnson, Lisa M.; Ketas, Thomas J.; Klasse, Per Johan; Lu, Min; Moore, John P.; Gellman, Samuel H.; (Cornell); (UW)

    2009-10-05

    Unnatural oligomers that can mimic protein surfaces offer a potentially useful strategy for blocking biomedically important protein-protein interactions. Here we evaluate an approach based on combining {alpha}- and {beta}-amino acid residues in the context of a polypeptide sequence from the HIV protein gp41, which represents an excellent testbed because of the wealth of available structural and biological information. We show that {alpha}/{beta}-peptides can mimic structural and functional properties of a critical gp41 subunit. Physical studies in solution, crystallographic data, and results from cell-fusion and virus-infectivity assays collectively indicate that the gp41-mimetic {alpha}/{beta}-peptides effectively block HIV-cell fusion via a mechanism comparable to that of gp41-derived {alpha}-peptides. An optimized {alpha}/{beta}-peptide is far less susceptible to proteolytic degradation than is an analogous {alpha}-peptide. Our findings show how a two-stage design approach, in which sequence-based {alpha} {yields} {beta} replacements are followed by site-specific backbone rigidification, can lead to physical and biological mimicry of a natural biorecognition process.

  8. Differential Superiority of Heavy Charged-Particle Irradiation to X-Rays: Studies on Biological Effectiveness and Side Effect Mechanisms in Multicellular Tumor and Normal Tissue Models.

    Science.gov (United States)

    Walenta, Stefan; Mueller-Klieser, Wolfgang

    2016-01-01

    This review is focused on the radiobiology of carbon ions compared to X-rays using multicellular models of tumors and normal mucosa. The first part summarizes basic radiobiological effects, as observed in cancer cells. The second, more clinically oriented part of the review, deals with radiation-induced cell migration and mucositis. Multicellular spheroids from V79 hamster cells were irradiated with X-rays or carbon ions under ambient or restricted oxygen supply conditions. Reliable oxygen enhancement ratios could be derived to be 2.9, 2.8, and 1.4 for irradiation with photons, (12)C(+6) in the plateau region, and (12)C(+6) in the Bragg peak, respectively. Similarly, a relative biological effectiveness of 4.3 and 2.1 for ambient pO2 and hypoxia was obtained, respectively. The high effectiveness of carbon ions was reflected by an enhanced accumulation of cells in G2/M and a dose-dependent massive induction of apoptosis. These data clearly show that heavy charged particles are more efficient in sterilizing tumor cells than conventional irradiation even under hypoxic conditions. Clinically relevant doses (3 Gy) of X-rays induced an increase in migratory activity of U87 but not of LN229 or HCT116 tumor cells. Such an increase in cell motility following irradiation in situ could be the source of recurrence. In contrast, carbon ion treatment was associated with a dose-dependent decrease in migration with all cell lines and under all conditions investigated. The radiation-induced loss of cell motility was correlated, in most cases, with corresponding changes in β1 integrin expression. The photon-induced increase in cell migration was paralleled by an elevated phosphorylation status of the epidermal growth factor receptor and AKT-ERK1/2 pathway. Such a hyperphosphorylation did not occur during (12)C(+6) irradiation under all conditions registered. Comparing the gene toxicity of X-rays with that of particles using the γH2AX technique in organotypic cultures of the oral

  9. Calculation of Bremsstrahlung energy spectrum induced by beta ray

    CERN Document Server

    Fukano, S

    2003-01-01

    Bremsstrahlung energy spectra induced by beta ray from radionuclides sup 3 H, sup 6 sup 3 Ni, sup 1 sup 4 C, sup 1 sup 4 sup 7 Pm, sup 9 sup 0 Sr, sup 3 sup 2 P and sup 9 sup 0 Y are calculated by using numerical data of radiation yield published by Berger et. al. and compared with those obtained from classical approximate expressions of Wu and Segre. The results for sup 3 H, sup 6 sup 3 Ni, sup 1 sup 4 C and sup 1 sup 4 sup 7 Pm are in good agreement with those from Segre's, while spectra from such as sup 3 sup 2 P and sup 9 sup 0 Y are similar to those obtained by using Wu's expression. The result for sup 9 sup 0 Sr is in fair agreement with those from Wu's and Segre's.

  10. Beta decay and the origins of biological chirality - Experimental results

    Science.gov (United States)

    Gidley, D. W.; Rich, A.; Van House, J.; Zitzewitz, P. W.

    1982-01-01

    Preliminary experimental results are presented of an investigation of the possible role of preferential radiolysis by electrons emitted in the beta decay of radionuclides, a parity-nonconserving process, in the universal causation of the optical activity of biological compounds. Experiments were designed to measure the asymmetry in the production of triplet positronium upon the bombardment of an amino acid powder target by a collimated beam of positrons as positron helicity or target chirality is reversed. No asymmetry down to a level of 0.0007 is found in experiments on the D and L forms of cystine and tryptophan, indicating an asymmetry in positronium formation cross section of less than 0.01, while an asymmetry of 0.0031 is found for leucine, corresponding to a formation cross section asymmetry of about 0.04

  11. Crystallochemical study of amides derived from 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid by X-ray diffraction; Estudo cristaloquimico de amidas derivadas do acido 6{alpha}, 7{beta}-di- hidroxivouacapan-17 {beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Marcello Cardoso; Prado Gambardella, Maria Teresa do [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Dept. de Quimica e Fisica Molecular

    1995-12-31

    Abstract. The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti inflammatory and analgesic properties. The purpose of this work is the characterization of amides derived from DVA, in order to understand the relationship between Chemical Structure and Biological Activity of Vouacapanes. The structures of DVA derivatives will be solved by single-crystal X-ray diffraction. (author) 15 refs., 2 figs.

  12. Crystallochemical study of esters derived from 6{alpha}, 7{beta}-diidroxivouacapan-17{beta}-oic acid by x-ray diffraction; Estudo cristaloquimico de esteres derivados do acido 6{alpha}, 6{beta}-di-hidroxivouacapan-17{beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Abrahao Junior, Odonirio [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica

    1995-12-31

    The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti-inflammatory and analgesic properties. The purpose of this work is the characterisation by x-ray single crystal diffraction technique of esters derived from DVA, to understand the relationship between chemical structure and biological activity of vouacapanes. (author) 15 refs.

  13. The origins of radiotherapy: discovery of biological effects of X-rays by Freund in 1897, Kienböck's crucial experiments in 1900, and still it is the dose.

    Science.gov (United States)

    Widder, Joachim

    2014-07-01

    The discovery of X-rays by Wilhelm Conrad Röntgen (1845-1923) was triggered by pursuing an anomalous phenomenon: arousal of fluorescence at a distance from tubes in which cathode rays were elicited, a phenomenon which suggested the existence of a new kind of ray other than cathode rays. The discovery of biological effects of these X-rays by Leopold Freund (1868-1943) was triggered by pursuit of the purportedly useless phenomenon of epilation and dermatitis ensuing from X-ray-diagnostic experiments that others had reported. The crucial experiments performed by Robert Kienböck (1871-1953) entailed the proof that X-ray-dose, not electric phenomena, was the active agent of biological effects ensuing when illuminating the skin using Röntgen tubes. For both the discovery of X-rays and the discovery of their biological effectiveness, priority did not matter, but understanding the physical and medico-biological significance of phenomena that others had ignored as a nuisance. Present discussions about the clinical relevance of improving the dose distribution including protons and other charged particles resemble those around 1900 to a certain degree.

  14. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  15. Differential superiority of heavy charged-particle irradiation to x-rays: Studies on biological effectivenes and side effect mechanisms in multicellular tumor and normal tissue models

    Directory of Open Access Journals (Sweden)

    Stefan eWalenta

    2016-02-01

    Full Text Available This review is focused on the radiobiology of carbon ions compared to x-rays using multicellular models of tumors and normal mucosa. The first part summarizes basic radiobiological effects, as observed in cancer cells. The second, more clinically oriented part of the review deals with radiation-induced cell migration and mucositis.Multicellular spheroids (MCS from V79 hamster cells were irradiated with x-rays or carbon ions under ambient or restricted oxygen supply conditions. Oxygen enhancement ratios (OER were 2.9, 2.8, and 1.4 for irradiation with photons, 12C+6 in the plateau region, and 12C+6 in the Bragg peak, respectively. A relative biological effectiveness (RBE of 4.3 and 2.1 for ambient pO2 and hypoxia was obtained, respectively. The high effectiveness of carbon ions was reflected by an enhanced accumulation of cells in G2/M, and a dose-dependent massive induction of apoptosis. Clinically relevant doses (3 Gy of x-rays induced an increase in migratory activity of U87 but not of LN229 or HCT116 tumor cells. Such an increase in cell motility following irradiation in situ could be the source of recurrence. In contrast, carbon ion treatment was associated with a dose-dependent decrease in migration with all cell lines and under all conditions investigated. The radiation-induced loss of cell motility was correlated, in most cases, with corresponding changes in 1 integrin expression. Unlike with particles, the photon-induced increase in cell migration was paralleled by an elevated phosphorylation status of the epidermal growth factor receptor (EGFR and AKT-ERK1/2 pathway. Comparing the gene toxicity of x-rays with that of particles using the gamma-H2AX technique in organotypic cultures of the oral mucosa, the superior effectiveness of heavy ions was confirmed by a two-fold higher number of foci per nucleus. Pro-inflammatory signs, however, were similar for both treatment modalities, e. g., the activation of NFkappaB, and the release of IL

  16. Effect of pre-exposure to beta rays of tritium on some biochemical parameters measured in organs of rats subsequently irradiated with fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Petcu, I.; Moisoi, N.; Savu, D.; Constantinescu, B. [Dept. of Health and Environmental Physics, Horia Hulubei Inst. of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

    2002-07-01

    The experiment examined biological responses produced by combined sequential exposure to low-level tritium contamination, followed by challenging irradiation with fast neutrons. Modifications of endogenous antioxidant potential of different organs in rats were discussed in relation to tissue radiosensitivity. Rats pre-contaminated to 7 cGy and 35 cGy have been additionally irradiated to 1 Gy with fast neutrons. Lipid peroxide level was determined in liver, kidney, small intestine, spleen, bone marrow, and plasma. Reduced glutathione (GSH) level and glucose-6-phosphate dehydrogenase (G6PDH) activity were determined in erythrocytes. An in vitro thymidine uptake assay was performed in isolated bone marrow cells. The lipid peroxide level decreased significantly only in liver and kidney from rats pre-exposed to 35 cGy. For small intestine and spleen, tissues of comparatively higher radiosensitivity, no induced radioprotection was observed, as reflected in the homeostasis of the lipid peroxides. The same behavior was observed in bone marrow, the most radiosensitive tissue studied. However, the bone marrow thymidine-incorporation assay revealed a possible adaptive-type reaction in rats pre-exposed to 35 cGy. We conclude that for radiosensitive tissues pre-exposure to chronic low doses of low linear energy transfer (LET) irradiation has no protective effect on their antioxidant status, whereas a protective effect is observed in radioresistent tissues. (author)

  17. The depth-dependence of the biological effectiveness of 60Co gamma rays in a large absorber determined by dicentric chromosomes in human lymphocytes.

    Science.gov (United States)

    Schmid, Ernst; Roos, Hartmut; Kramer, Hans-Michael

    2008-01-01

    Radiobiological evidence is shown concerning a significant depth-dependence of the maximum relative biological effectiveness at limiting low doses (RBE(M)) of (60)Co gamma rays in a cubic polymethylmethacrylate (PMMA) phantom of 30 cm edge length. Using the dose-response curve for the dicentric data in human lymphocytes obtained in the present experiment at a depth of 20 cm, together with the comprehensive and consistent data set determined earlier at smaller depths of the PMMA phantom, there is an increase in the RBE(M) value by a factor of 2.18 +/- 1.25 at a depth of 20 cm relative to 1 cm in the phantom. All the dicentric data are based on identical exposure durations and irradiation temperatures as well as identical culture and evaluation conditions, with blood from the same donor.

  18. Microdosimetric analysis confirms similar biological effectiveness of external exposure to gamma-rays and internal exposure to 137Cs, 134Cs, and 131I.

    Science.gov (United States)

    Sato, Tatsuhiko; Manabe, Kentaro; Hamada, Nobuyuki

    2014-01-01

    The risk of internal exposure to 137Cs, 134Cs, and 131I is of great public concern after the accident at the Fukushima-Daiichi nuclear power plant. The relative biological effectiveness (RBE, defined herein as effectiveness of internal exposure relative to the external exposure to γ-rays) is occasionally believed to be much greater than unity due to insufficient discussions on the difference of their microdosimetric profiles. We therefore performed a Monte Carlo particle transport simulation in ideally aligned cell systems to calculate the probability densities of absorbed doses in subcellular and intranuclear scales for internal exposures to electrons emitted from 137Cs, 134Cs, and 131I, as well as the external exposure to 662 keV photons. The RBE due to the inhomogeneous radioactive isotope (RI) distribution in subcellular structures and the high ionization density around the particle trajectories was then derived from the calculated microdosimetric probability density. The RBE for the bystander effect was also estimated from the probability density, considering its non-linear dose response. The RBE due to the high ionization density and that for the bystander effect were very close to 1, because the microdosimetric probability densities were nearly identical between the internal exposures and the external exposure from the 662 keV photons. On the other hand, the RBE due to the RI inhomogeneity largely depended on the intranuclear RI concentration and cell size, but their maximum possible RBE was only 1.04 even under conservative assumptions. Thus, it can be concluded from the microdosimetric viewpoint that the risk from internal exposures to 137Cs, 134Cs, and 131I should be nearly equivalent to that of external exposure to γ-rays at the same absorbed dose level, as suggested in the current recommendations of the International Commission on Radiological Protection.

  19. A glimpse of structural biology through X-ray crystallography.

    Science.gov (United States)

    Shi, Yigong

    2014-11-20

    Since determination of the myoglobin structure in 1957, X-ray crystallography, as the anchoring tool of structural biology, has played an instrumental role in deciphering the secrets of life. Knowledge gained through X-ray crystallography has fundamentally advanced our views on cellular processes and greatly facilitated development of modern medicine. In this brief narrative, I describe my personal understanding of the evolution of structural biology through X-ray crystallography-using as examples mechanistic understanding of protein kinases and integral membrane proteins-and comment on the impact of technological development and outlook of X-ray crystallography.

  20. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice.

    Science.gov (United States)

    Johnson, J R; Myers, D K; Jackson, J S; Dunford, D W; Gragtmans, N J; Wyatt, H M; Jones, A R; Percy, D H

    1995-10-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.

  1. Pile-up corrections for high-precision superallowed {beta} decay half-life measurements via {gamma}-ray photopeak counting

    Energy Technology Data Exchange (ETDEWEB)

    Grinyer, G.F. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada)], E-mail: ggrinyer@physics.uoguelph.ca; Svensson, C.E.; Andreoiu, C. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Andreyev, A.N. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Austin, R.A.E. [Department of Astronomy and Physics, St. Mary' s University, Halifax, NS, B3H 3C3 (Canada); Ball, G.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Bandyopadhyay, D. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Chakrawarthy, R.S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Finlay, P. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Garrett, P.E. [Department of Physics, University of Guelph, Guelph, Ont, Canada N1G 2W1 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Hackman, G. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Hyland, B. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Kulp, W.D. [School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 0430 (United States); Leach, K.G. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Leslie, J.R. [Department of Physics, Queen' s University, Kingston, Ont., K7L 3N6 (Canada); Morton, A.C.; Pearson, C.J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Phillips, A.A. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada); Sarazin, F. [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States); Schumaker, M.A. [Department of Physics, University of Guelph, Guelph, Ont, N1G 2W1 (Canada)] (and others)

    2007-09-11

    A general technique that corrects {gamma}-ray gated {beta} decay-curve data for detector pulse pile-up is presented. The method includes corrections for non-zero time-resolution and energy-threshold effects in addition to a special treatment of saturating events due to cosmic rays. This technique is verified through a Monte Carlo simulation and experimental data using radioactive beams of {sup 26}Na implanted at the center of the 8{pi}{gamma}-ray spectrometer at the ISAC facility at TRIUMF in Vancouver, Canada. The {beta}-decay half-life of {sup 26}Na obtained from counting 1809-keV {gamma}-ray photopeaks emitted by the daughter {sup 26}Mg was determined to be T{sub 1/2}=1.07167{+-}0.00055s following a 27{sigma} correction for detector pulse pile-up. This result is in excellent agreement with the result of a previous measurement that employed direct {beta} counting and demonstrates the feasibility of high-precision {beta}-decay half-life measurements through the use of high-purity germanium {gamma}-ray detectors. The technique presented here, while motivated by superallowed-Fermi {beta} decay studies, is general and can be used for all half-life determinations (e.g. {alpha}-, {beta}-, X-ray, fission) in which a {gamma}-ray photopeak is used to select the decays of a particular isotope.

  2. Establishment of Korea-Russia bilateral research collaboration for studies on biological effects of cosmic ray and space radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Juwoon; Kim, Dongho; Choi, Jongil; Song, Beomseok; Kim, Jaekyung; Kang, Oilhyun; Lee, Yoonjong; Kim, Jinhong; Jo, Minho

    2011-04-15

    {Omicron} KAERI-IBMP joint workshop on countermeasure and application researches to space environments - Sharing of state-of-the-art researches on space radiobiology using bio-satellites (BION-M1, Photon-soil) and ISS module (Bio-risk) was conducted - Sharing and discussion of state-of-the-art researches on dosimetry of space radiation and its affect on organisms were conducted. {Omicron} Making a contract on KAERI-IBMP Joint Research using Bio-risk module - Contract on KAERI-IBMP Joint Research to evaluate effect of space environment (microgravity and space radiation) on fermentative fungi (Aspergillus oryzae), Algae (Nostoc sp.), and plant seeds (rice, Arabidopsis thaliana, Brachypodium distachyon) was made in November, 2010. {Omicron} Discussion on new Joint Researches on evaluation of space radiation on organisms - Final step on Bion-M projects in terms of evaluation of physiological changes of lactic acid bacteria consumed by Mouse - Discussing new joint research on evaluation of physiological changes of primate by space radiation {Omicron} Establishment and management of the practical working group to invite a branch office of the IBMP in Korea - The system and the working group to implement cooperating researches between KAERI-IBMP on space radiation were established.

  3. Development of continuous monitor for multiple beta-ray nuclides in liquid radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Uk Won; Seon, G. I.; Kong, G. N.; Chin, H.; Park, J. H.; Yuk, I. S.; Han, W. Y. [Korea Astronomy and Space Science Institute, Taejon (Korea, Republic of)

    2001-03-15

    Continuous monitor system of multiple beta-ray nuclides was designed conceptually while keeping the optimization and the automation in mind. The conincidence MCA was designed to maintain, repair and upgrade with ease. DSP was adopted to realize hardware function using software and to miniaturize the coincidence Multi Channel Analyzer (MCA). The MCA system showed 99% background rejection rate, and was applied well to gamma-ray system using {sup 60}C0. An algorithm using least square method was developed for simultaneous radioassay of multiple beta-ray nuclides. The algorithm was tested using the simulation and was applied to experimental data. The results show that the algorithm is suitable to continous monitor system of multiple beta-ray nuclides.

  4. Volume Effects in Discrete beta functions

    CERN Document Server

    Liu, Yuzhi; Zou, Haiyuan

    2011-01-01

    We calculate discrete beta functions corresponding to the two-lattice matching for the 2D O(N) models and Dyson's hierarchical model. We describe and explain finite-size effects such as the appearance of a nontrivial infrared fixed point that goes to infinity at infinite volume or the merging of an infrared and an ultraviolet fixed point. We present extensions of the RG flows to the complex coupling plane. We discuss the possibility of constructing a continuous beta function from the discrete one by using functional conjugation methods. We briefly discuss the relevance of these findings for the search of nontrivial fixed points in multiflavor lattice gauge theory models.

  5. Graphite mixed magnesium borate TL dosemeters for beta ray dosimetry

    DEFF Research Database (Denmark)

    Prokic, M; Christensen, Poul

    1984-01-01

    Sintered MgB4O7:Dy dosemeters with graphite contents from 1 to 10% were investigated for application for personnel dosimetry. Data are given on dose response, dose threshold, reproducibility, beta energy response and fading. Furthermore, results from practical field experiments are presented...

  6. Identification of new pancreatic beta cell targets for in vivo imaging by a systems biology approach.

    Science.gov (United States)

    Bouckenooghe, Thomas; Flamez, Daisy; Ortis, Fernanda; Goldman, Serge; Eizirik, Decio L

    2010-05-01

    Systems biology is an emergent field that aims to understand biological systems at system-level. The increasing power of genome sequencing techniques and ranges of other molecular biology techniques is enabling the accumulation of in-depth knowledge of biological systems. This growing information, properly quantified, analysed and presented, will eventually allow the establishment of a system-based cartography of different cellular populations within the organism, and of their interactions at the tissue and organ levels. It will also allow the identification of specific markers of individual cell types. Systems biology approaches to discover diagnostic markers may have an important role in diabetes. There are presently no reliable ways to quantify beta cell mass (BCM) in vivo, which hampers the understanding of the pathogenesis and natural history of diabetes, and the development of novel therapies to preserve BCM. To solve this problem, novel and specific beta cell biomarkers must be identified to enable adequate in vivo imaging by methods such as Positron Emission Tomography (PET). The ideal biomarker should allow measurements by a minimally invasive technology enabling repeated examinations over time, should identify the early stages of decreased BCM, and should provide information on progression of beta cell loss and eventual responses to agents aiming to arrest or revert beta cell loss in diabetes. The present review briefly describes the "state-of-the-art" in the field, and then proposes a step-by-step systems biology approach for the identification and initial testing of novel candidates for beta cell imaging.

  7. {beta}-Ray angular distribution from purely nuclear spin aligned {sup 20}F

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomo, T., E-mail: nagatomo@riken.jp [RIKEN Nishina Center (Japan); Matsuta, K. [Osaka University (Japan); Minamisono, K. [NSCL/MSU (United States); Sumikama, T. [Tokyo University of Science (Japan); Mihara, M. [Osaka University (Japan); Ozawa, A.; Tagishi, Y. [University of Tsukuba (Japan); Ogura, M.; Matsumiya, R.; Fukuda, M. [Osaka University (Japan); Yamaguchi, M.; Yasuno, T.; Ohta, H.; Hashizume, Y. [University of Tsukuba (Japan); Fujiwara, H. [Osaka University (Japan); Chiba, A. [University of Tsukuba (Japan); Minamisono, T. [Fukui University of Technology (Japan)

    2007-11-15

    The alignment correlation term in the {beta}-ray angular distribution from purely nuclear spin aligned {sup 20}F has been measured to test the G-parity conservation law which is one of the fundamental symmetries in the weak nucleon current. We utilized the hyperfine interaction of {sup 20}F in an MgF{sub 2} single crystal and successfully created the pure alignment from the polarization by means of the spin manipulation technique based on the {beta}-NMR method.

  8. Beta-ray angular distributions of spin aligned {sup 8}Li and {sup 8}B

    Energy Technology Data Exchange (ETDEWEB)

    Sumikama, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Iwakoshi, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Nagatomo, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Ogura, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Nakashima, Y. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Fujiwara, H. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Matsuta, K. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Minamisono, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Mihara, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Fukuda, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Minamisono, K. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Yamaguchi, T. [Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany)

    2004-12-27

    The alignment correlation terms in the {beta}-ray angular distributions from spin aligned {sup 8}Li and {sup 8}B have been measured precisely. The difference of these terms between the mirror pair is compared with the prediction. As a result, the G-parity violating induced tensor term is found to be small. The significant contribution from the second-forbidden matrix elements is shown by comparing with the {beta}-{alpha} correlation coefficients.

  9. Quantum Effects in Biology

    Science.gov (United States)

    Mohseni, Masoud; Omar, Yasser; Engel, Gregory S.; Plenio, Martin B.

    2014-08-01

    List of contributors; Preface; Part I. Introduction: 1. Quantum biology: introduction Graham R. Fleming and Gregory D. Scholes; 2. Open quantum system approaches to biological systems Alireza Shabani, Masoud Mohseni, Seogjoo Jang, Akihito Ishizaki, Martin Plenio, Patrick Rebentrost, Alàn Aspuru-Guzik, Jianshu Cao, Seth Lloyd and Robert Silbey; 3. Generalized Förster resonance energy transfer Seogjoo Jang, Hoda Hossein-Nejad and Gregory D. Scholes; 4. Multidimensional electronic spectroscopy Tomáš Mančal; Part II. Quantum Effects in Bacterial Photosynthetic Energy Transfer: 5. Structure, function, and quantum dynamics of pigment protein complexes Ioan Kosztin and Klaus Schulten; 6. Direct observation of quantum coherence Gregory S. Engel; 7. Environment-assisted quantum transport Masoud Mohseni, Alàn Aspuru-Guzik, Patrick Rebentrost, Alireza Shabani, Seth Lloyd, Susana F. Huelga and Martin B. Plenio; Part III. Quantum Effects in Higher Organisms and Applications: 8. Excitation energy transfer in higher plants Elisabet Romero, Vladimir I. Novoderezhkin and Rienk van Grondelle; 9. Electron transfer in proteins Spiros S. Skourtis; 10. A chemical compass for bird navigation Ilia A. Solov'yov, Thorsten Ritz, Klaus Schulten and Peter J. Hore; 11. Quantum biology of retinal Klaus Schulten and Shigehiko Hayashi; 12. Quantum vibrational effects on sense of smell A. M. Stoneham, L. Turin, J. C. Brookes and A. P. Horsfield; 13. A perspective on possible manifestations of entanglement in biological systems Hans J. Briegel and Sandu Popescu; 14. Design and applications of bio-inspired quantum materials Mohan Sarovar, Dörthe M. Eisele and K. Birgitta Whaley; 15. Coherent excitons in carbon nanotubes Leonas Valkunas and Darius Abramavicius; Glossary; References; Index.

  10. Biological applications of cryo-soft X-ray tomography.

    Science.gov (United States)

    Duke, E; Dent, K; Razi, M; Collinson, L M

    2014-08-01

    X-rays are used for imaging many different types of biological specimen, ranging from live organisms to the individual cells and proteins from which they are made. The level of detail achieved as a result of the imaging varies depending on both the sample and the technique used. One of the most recent technical developments in X-ray imaging is that of the soft X-ray microscope, designed to allow the internal structure of individual biological cells to be explored. With a field of view of ∼10-20 × ∼10-20 μm, a penetration depth of ∼10 μm and a resolution of ∼40 nm(3), the soft X-ray microscope neatly fits between the imaging capabilities of light and electron microscopes.

  11. Applied Developmental Biology: Making Human Pancreatic Beta Cells for Diabetics.

    Science.gov (United States)

    Melton, Douglas A

    2016-01-01

    Understanding the genes and signaling pathways that determine the differentiation and fate of a cell is a central goal of developmental biology. Using that information to gain mastery over the fates of cells presents new approaches to cell transplantation and drug discovery for human diseases including diabetes.

  12. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.R. [Battelle Pacific Northwest Labs., Health Protection Branch, Health Div., Richland, WA (United States); Myers, D.K.; Jackson, J.S.; Dunford, D.W.; Gragtmans, N.J.; Wyatt, H.M.; Jones, A.R. [Atomic Energy of Canada Limited, Chalk River, Ontairo (Canada); Percy, D.H. [Univ. of Guelph, Ontario Veterinary College, Guelph, Ontario (Canada)

    1995-07-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium {beta} rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium 13 rays compared to X rays ranged from 1.0 {+-} 0.5 to 1.3 {+-} 0.3. A best estimate of the RBE for this experiment was about 1.2 {+-} 0.3. A w{sub R} value of 1 would thus appear to be more appropriate than a W{sub R} of 2 for tritium {beta} rays. (author)

  13. High-dose dosimetry of beta rays using blue beryl dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Lucas S. do, E-mail: lsatiro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Watanabe, Shigueo; Bittencour, Jose F., E-mail: Lacifid@if.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica. Departamento de Fisica Nuclear

    2015-07-01

    High dose radiation is widely used in industrial applications as sterilization of medical products, improvement of materials properties, color enhancement of jewelry stones, etc. The radiation dosimetry of high doses is quite important for these applications. In this work we have investigated the usage of blue beryl crystal also known as aquamarine in high dose dosimetry of beta rays. Some works have shown that silicate minerals exhibit a good Thermoluminescent response when irradiated up to 2000 kGy of gamma rays. Here, we have produced small beryl pellets of approximately 5 mm in diameter and 3 mm thickness to measure high doses of beta rays produced at an electron accelerator at IPEN. Twelve beryl dosimeters were made and six of them were irradiated from 10kGy up to 100 kGy. The technique used to create a calibration curve was the thermoluminescence using the glow peak at 310°C. (author)

  14. Field measurements of beta ray energy spectra in CANDU nuclear generating stations

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Physics); Hirning, C.R. (Ontario Hydro, Whitby, ON (Canada)); Yuen, P.S.; Aikens, M.S. (AECL Research, Chalk River, ON (Canada). Chalk River Labs.)

    1994-01-01

    Field measurements of beta ray energy spectra have been carried out at various locations in CANDU nuclear generating stations operated by Ontario Hydro. The beta ray energy spectrometer consists of a 5 cm diameter x 2 cm thick BC-404 plastic scintillator situated behind a 100 [mu]m thick, totally depleted, silicon detector. Photon events are rejected by requiring a coincidence between the two detectors. The spectrometer is capable of measuring electron energies from 125 keV to 3.5 MeV. Beta ray energy spectra have been measured for uncontaminated and contaminated fueling machine components, fueling machine swipes and a reactor containment vault. The degree of protection afforded by various articles of protective clothing has also been investigated for the various fueling machine components. Monte Carlo calculations have been used to estimate beta factors for 100 mg.cm[sup -2] and 240 mg.cm[sup -2] LiF-TLD chips, which are used as 'skin-and 'extremity' dosemeters in the Ontario Hydro Radiation Dosimetry Programme. (Author).

  15. The Secret XUV Lives of Cepheids: FUV/X-ray Observations of Polaris and beta Dor

    CERN Document Server

    Engle, Scott G; DePasquale, Joseph; Evans, Nancy

    2009-01-01

    We report on the surprising recent discovery of strong FUV emissions in two bright, nearby Classical Cepheids from analyses of FUSE archival observations and one of our own approved observations just prior to the failure of the satellite. Polaris and beta Dor are currently the only two Cepheids to have been observed with FUSE, and beta Dor is the only one to have multiple spectra. Both Cepheids show strong C III (977A, 1176A) and O VI (1032A, 1038A) emissions, indicative of 50,000-500,000 K plasma, well above the photospheric temperatures of the stars. More remarkably, beta Dor displays variability in the FUV emission strengths which appears to be correlated to its 9.84-d pulsation period. This phenomenon has never before been observed in Cepheids. The FUV studies are presented along with our recent Chandra/XMM X-ray observations of Polaris and beta Dor, in which X-ray detections were found for both stars (as well as for the prototype Classical Cepheid, delta Cep). Further X-ray observations have been propose...

  16. Total Absorption Gamma-Ray Spectroscopy of 87Br, 88Br and 94Rb Beta-Delayed Neutron Emitters

    CERN Document Server

    Valencia, E; Algora, A; Agramunt, J; Rubio, B; Rice, S; Gelletly, W; Regan, P; Zakari-Issoufou, A -A; Fallot, M; Porta, A; Rissanen, J; Eronen, T; Aysto, J; Batist, L; Bowry, M; Bui, V M; Caballero-Folch, R; Cano-Ott, D; Elomaa, V -V; Estevez, E; Farrelly, G F; Garcia, A R; Gomez-Hornillos, B; Gorlychev, V; Hakala, J; Jordan, M D; Jokinen, A; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Moore, I; Penttila, H; Podolyak, Zs; Reponen, M; Sonnenschein, V; Sonzogni, A A

    2016-01-01

    We investigate the decay of 87Br, 88Br and 94Rb using total absorption gamma-ray spectroscopy. These important fission products are beta-delayed neutron emitters. Our data show considerable gamma-intensity, so far unobserved in high-resolution gamma-ray spectroscopy, from states at high excitation energy. We also find significant differences with the beta intensity that can be deduced from existing measurements of the beta spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the range 1 to 100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for gamma emission from neutron unbound s...

  17. The origins of radiotherapy : Discovery of biological effects of X-rays by Freund in 1897, Kienbock's crucial experiments in 1900, and still it is the dose

    NARCIS (Netherlands)

    Widder, Joachim

    2014-01-01

    The discovery of X-rays by Wilhelm Conrad Rontgen (1845-1923) was triggered by pursuing an anomalous phenomenon: arousal of fluorescence at a distance from tubes in which cathode rays were elicited, a phenomenon which suggested the existence of a new kind of ray other than cathode rays. The discover

  18. Self-assembly of a novel beta-In2S3 nanostructure exhibiting strong quantum confinement effects.

    Science.gov (United States)

    Zhang, Wu; Ma, Dekun; Huang, Zhen; Tang, Qun; Xie, Qin; Qian, Yitai

    2005-05-01

    The 3D beta-In2S3 flowerlike architecture assembled from nanoflakes was prepared via a novel complex-precursor assisted (CPA) solvothermal route. The as-prepared beta-In2S3 powder was characterized by X-ray diffraction pattern (XRD), X-ray photoelectron spectra (XPS), transition electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), ultraviolet-visible light (UV-vis) spectra, and photoluminescence spectrum. The novel 3D beta-In2S3 nanostructure exhibit a strong quantum confinement effect. FT-IR spectra were used to investigate the coordinative chemical effect in the complex. A possible mechanism was discussed.

  19. Dopaminergic and beta-adrenergic effects on gastric antral motility

    DEFF Research Database (Denmark)

    Bech, K; Hovendal, C P; Gottrup, F

    1984-01-01

    of bethanechol or pentagastrin inducing motor activity patterns as in the phase III of the MMC and the digestive state respectively. The stimulated antral motility was dose-dependently inhibited by dopamine. The effect was significantly blocked by specifically acting dopaminergic blockers, while alpha- and beta......-adrenergic blockers were without any significant effects. Dose-response experiments with bethanechol and dopamine showed inhibition of a non-competitive type. Isoprenaline was used alone and in conjunction with selective blockade of beta 1- and beta 2-receptors during infusion of bethanechol which induces a pattern...... similar to phase III in the migrating myoelectric complex. The stimulated antral motility was dose-dependently inhibited by isoprenaline. The effect could be significantly blocked by propranolol (beta 1 + beta 2-adrenoceptor blocker) and by using in conjunction the beta 1-adrenoceptor blocker practolol...

  20. Enhanced Gamma-Ray Emission from Neutron Unbound States Populated in Beta Decay

    CERN Document Server

    Tain, J L; Algora, A; Agramunt, J; Rubio, B; Rice, S; Gelletly, W; Regan, P; Zakari-Issoufou, A -A; Fallot, M; Porta, A; Rissanen, J; Eronen, T; Aysto, J; Batist, L; Bowry, M; Bui, V M; Caballero-Folch, R; Cano-Ott, D; Elomaa, V -V; Estevez, E; Farrelly, G F; Garcia, A R; Gomez-Hornillos, B; Gorlychev, V; Hakala, J; Jordan, M D; Jokinen, A; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Moore, I; Penttila, H; Podolyak, Zs; Reponen, M; Sonnenschein, V; Sonzogni, A A

    2015-01-01

    Total absorption spectroscopy was used to investigate the beta-decay intensity to states above the neutron separation energy followed by gamma-ray emission in 87,88Br and 94Rb. Accurate results were obtained thanks to a careful control of systematic errors. An unexpectedly large gamma intensity was observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The gamma branching as a function of excitation energy was compared to Hauser-Feshbach model calculations. For 87Br and 88Br the gamma branching reaches 57% and 20% respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich 94Rb the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper c...

  1. Searches for Active and Sterile Neutrinos in Beta-Ray Spectra

    CERN Document Server

    Dragoun, Otokar

    2015-01-01

    Although neutrinos are probably the most abundant particles of the universe their mass is yet unknown. The oscillation experiments proved that at least one of the neutrino mass states is heavier than 0.05 eV. Strongly model dependent interpretations of cosmological observations yielded for the sum of the neutrino mass states the values between 0.12 and 1.7 eV. The almost model independent analyses of measured tritium \\b{eta}- spectra provided the upper limit of the effective electron neutrino mass of 2 eV. The upcoming KATRIN experiment aims to achieve ten times higher sensitivity. In this review, we try to summarize the experience of two generations of \\b{eta}-ray spectroscopists who improved the limit of the neutrino mass by three orders of magnitude. We describe important steps in the development of radioactive sources and electron spectrometers, and recapitulate the lessons from now disproved claims for the neutrino of 30 eV mass and the 17 keV neutrino with an admixture larger than 0.07 %. We also pay at...

  2. Measurements of beta ray spectra in CANDU nuclear generating stations using a silicon detector coincidence telescope

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S.; Weizman, Y. [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Physics; Hirning, C.R. [Ontario Hydro, Whitby, ON (Canada). Health Physics Dept.

    1996-12-31

    The measurement of beta ray spectra at various work locations inside nuclear generating stations operated by Ontario Hydro is described. The measurements were carried out using an advanced coincidence telescope spectrometer using silicon detectors only. The spectrometer is capable of measuring electron energies over the range 60 keV- 2500 keV with close to 100% coincidence efficiency. Photon rejection is carried out by requiring a coincidence between either two or three silicon detectors. Monte Carlo calculations were then used to estimate beta correction factors for the LiF:Mg,Ti elements used in the Ontario Hydro thermoluminescence dosemeters. Averaging over all the measured beta correction factors for the `skin` chip (100 mg.cm{sup -2}) results in a value of 2.73 {+-} 0.77 and for the extremity dosemeter (240 mg.cm{sup -2}) an average value of 4.42 {+-} 1.17 is obtained. These values are 57% and 120% greater, respectively, than the current values used by Ontario Hydro. In addition, beta correction factors for nine representative spectra were calculated for 40 mg.cm{sup -2} chips and 20 mg.cm{sup -2} chips and the results demonstrate the benefits of decreased dosemeter thickness. The average value of the beta correction factor, as well as the spread in the beta correction factor, decreases dramatically from 4.8 {+-} 2.1 (240 mg.cm{sup -2}) to 1.29 ``1.2`` +-`` 0.1 (20 mg.cm{sup -2}). (author).

  3. Quantum Effects in Biological Systems

    CERN Document Server

    2016-01-01

    Since the last decade the study of quantum mechanical phenomena in biological systems has become a vibrant field of research. Initially sparked by evidence of quantum effects in energy transport that is instrumental for photosynthesis, quantum biology asks the question of how methods and models from quantum theory can help us to understand fundamental mechanisms in living organisms. This approach entails a paradigm change challenging the related disciplines: The successful framework of quantum theory is taken out of its low-temperature, microscopic regimes and applied to hot and dense macroscopic environments, thereby extending the toolbox of biology and biochemistry at the same time. The Quantum Effects in Biological Systems conference is a platform for researchers from biology, chemistry and physics to present and discuss the latest developments in the field of quantum biology. After meetings in Lisbon (2009), Harvard (2010), Ulm (2011), Berkeley (2012), Vienna (2013), Singapore (2014) and Florence (2015),...

  4. Early and continuing effects of combined alpha and beta irradiation of the lung:

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Hahn, F.F.; Snipes, M.B.; Newton, G.J.; Eidson, A.F.; Mauderly, J.L.; Boecker, B.B.

    1988-03-01

    This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality from radiation pneumonitis and pulmonary fibrosis within 18 months. Both models were found to adequately predict the experimental observations after combined chronic alpha and beta irradiation of the lung. A relative biological effectiveness of approximately 7 was obtained for /sup 238/Pu alpha radiation compared to /sup 147/Pm beta radiation for both pulmonary functional morbidity and lethality from radiation pneumonitis and pulmonary fibrosis. 12 refs., 16 figs., 11 tabs.

  5. Effects of calcium impurity on phase relationship, ionic conductivity and microstructure of Na$^{+}$-$\\beta/beta"$-alumina solid electrolyte

    Indian Academy of Sciences (India)

    SUNG-TAE LEE; DAE-HAN LEE; SANG-MIN LEE; SANG-SOO HAN; SANG-HYUNG LEE; SUNG-KI LIM

    2016-06-01

    Ca-doped Na$^{+}$-$\\beta/beta"$-alumina was synthesized using a solid-state reaction. The changes in the properties of Na$^{+}$-$\\beta/beta"$-alumina resulting from the presence of Ca impurity were studied. Ca (0–5 wt%) was added to the respective samples, which were then sintered. The specimens were characterized using X-ray diffraction, scanningelectron microscopy, densimetry and impedance analysis. In the sintered specimens, the $\\beta"$-alumina phase fraction decreased as Ca content increased, whereas the relative sintered density increased. The surface morphology of Cadoped Na$^{+}$-$\\beta/beta"$-alumina specimens showed a Ca-rich layer, which was the main cause of increase in the specificresistance.

  6. Conformation, molecular packing and field effect mobility of regioregular beta,beta'-dihexylsexithiophiophene

    DEFF Research Database (Denmark)

    Kiriy, N.; Kiriy, A.; Bocharova, V.

    2004-01-01

    by the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique was found to be Sigmamu(min) = 3.9 x 10(-3) cm(2) V-1 s(-1), which is comparable with the PR-TRMC mobility found for alpha,omega-DH6T. The field-effect mobility (FEM) of beta,beta'-DH6T was found to be on the order of 10(-5) cm(2......) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...

  7. Biological Effectiveness of Antiproton Annihilation

    DEFF Research Database (Denmark)

    Maggiore, C.; Agazaryan, N.; Bassler, N.;

    2004-01-01

    from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The background, description, and status...

  8. Characteristic X-rays induced by electrons and positrons from {beta}-emitting radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chesta, M.A.; Mainardi, R.T. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5010 Cordoba (Argentina); Plivelic, T.S. [Consejo de Investigaciones Cientificas y Tecnicas (CONICET), 1033 Buenos Aires (Argentina)

    1998-11-01

    We have investigated the use of energetic electrons and positrons from low intensity {sup 90}Sr and {sup 22}Na radioactive sources respectively to produce characteristic radiation and compare the emission efficiencies of each kind of particle. A new proposed experimental set-up for radioisotope-excited X-ray fluorescence analysis is of the transparent source type and provides at least a ten-time increase in the intensity of characteristic X-rays emitted by the sample as compared to a standard radioactive source arrangement. Theoretically derived expressions for {beta}-particle penetration, transport and emission processes in a sample are presented, and experimental results of absolute characteristic X-ray yields induced by electrons and positrons from 31 pure chemical elements, from titanium to lead, have been included. The advantages of energetic {beta}-particles in comparison with other radiation sources are also discussed, in fact, a remarkable feature observed being that radiation yield changes by less than an order of magnitude across the whole range of the target atomic numbers herein considered. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Fast x-ray fluorescence microtomography of hydrated biological samples.

    Directory of Open Access Journals (Sweden)

    Enzo Lombi

    Full Text Available Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples.

  10. Effect of heating rate on temperature of titanium alloy (. cap alpha. +. beta. ). -->. beta. transformaton

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, V.N.; Ivasishin, O.M.; Markovskij, P.E. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)

    1985-01-01

    The effect of doping of two-phase titaniums alloys and morphology of initial structure on the Tsub(t) temperature shift value of (..cap alpha..+..beta..)..--> beta.. transformation depending on heating rate is investigated. It has been found that the Tsub(t) shift occurs in the strictly determined temperature range depending on chemical alloy composition. The Tsub(t) shift is directly proportional to the Ksub(..beta..) coefficient applied as a quantitative alloying characteristic as well as a dimensional factor equal either to the plate thickness or the ..cap alpha..-phase globule diameter depending on the type of initial structure. In the limits of this temperature range the (..cap alpha..+..beta..)..--> beta..-transformation occurs completely according to the diffusion mechanism. The critical heating rate at which maximum permissible Tsub(t) value is attained and above which its stabilization is observed is determined by the same parameters - the alloy doping degree characterized by the Ksub(..beta..) coefficient and the ..cap alpha..-phase crystal dimensions in the initial structure.

  11. Biological Effects of Acoustic Cavitation

    Science.gov (United States)

    2007-11-02

    rectified diffusion. 56 III. STABLE CAVITATION A. Introduction There are manv areas associated with the biological effects of ultrasound in which the...used said as cavitation indicators. Further, if clinical ultrasound systems are found to be inducing cavitation , either stable or transient, it will...O BIOLOGICAL EFFECTS OF ACOUSTIC CAVITATION by Lawrence A. Crum -- Physical Acoustics Research Laboratory Department of Physics and Astronomy ’ CTE

  12. Alignment correlation term in the {beta}-ray angular distribution from spin aligned {sup 20}Na

    Energy Technology Data Exchange (ETDEWEB)

    Minamisono, K. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B. C., V6T 2A3 (Canada); Matsuta, K. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Minamisono, T. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Levy, C.D.P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B. C., V6T 2A3 (Canada); Nagatomo, T. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Ogura, M. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Sumikama, T. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Behr, J.A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B. C., V6T 2A3 (Canada); Jackson, K.P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B. C., V6T 2A3 (Canada); Fujiwara, H. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Mihara, M. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan); Fukuda, M. [Department of Physics, Osaka University, Toyonaka 560-0043, Osaka (Japan)

    2004-12-27

    The alignment correlation term in the {beta}-ray angular distribution from nuclear-spin aligned {sup 20}Na(I{sup {pi}} = 2{sup +}, T{sub 1/2} = 449.7 ms) has been measured for the first time. A large enhancement of the time component d in the main axial vector current was preliminarily obtained and the higher order matrices j{sub 2} and j{sub 3} were also evaluated. In order to extract very small G-parity violating induced tensor term, the alignment correlation term of the mirror partner {sup 20}F have to be measured.

  13. High-pressure X-ray diffraction studies on {beta}-Ni(OH){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Garg, Nandini; Karmakar, S.; Sharma, S.M.Surinder M.; Busseto, E.; Sikka, S.K

    2004-06-15

    Using in situ X-ray diffraction, we have investigated the high-pressure behavior of {beta}-Ni(OH){sub 2} upto 10 GPa. No phase transformation was observed in this pressure range. Our studies show that the diffraction peaks show inherent broadening on increase of pressure. This suggests that H-lattice may be already disordered at ambient conditions and further increase in pressure may increase the lattice disorder as observed in Co(OH){sub 2} (Phys. Rev. B 66 (2002) 134301)

  14. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)

    2011-07-01

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  15. Modeling the Production of Beta-Delayed Gamma Rays for the Detection of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Hall, J M; Pruet, J A; Brown, D A; Descalle, M; Hedstrom, G W; Prussin, S G

    2005-02-14

    The objective of this LDRD project was to develop one or more models for the production of {beta}-delayed {gamma} rays following neutron-induced fission of a special nuclear material (SNM) and to define a standardized formatting scheme which will allow them to be incorporated into some of the modern, general-purpose Monte Carlo transport codes currently being used to simulate inspection techniques proposed for detecting fissionable material hidden in sea-going cargo containers. In this report, we will describe a Monte Carlo model for {beta}-delayed {gamma}-ray emission following the fission of SNM that can accommodate arbitrary time-dependent fission rates and photon collection histories. The model involves direct sampling of the independent fission yield distributions of the system, the branching ratios for decay of individual fission products and spectral distributions representing photon emission from each fission product and for each decay mode. While computationally intensive, it will be shown that this model can provide reasonably detailed estimates of the spectra that would be recorded by an arbitrary spectrometer and may prove quite useful in assessing the quality of evaluated data libraries and identifying gaps in the libraries. The accuracy of the model will be illustrated by comparing calculated and experimental spectra from the decay of short-lived fission products following the reactions {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f). For general-purpose transport calculations, where a detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may not be necessary, it will be shown that a simple parameterization of the {gamma}-ray source function can be defined which provides high-quality average spectral distributions that should suffice for calculations describing photons being transported through thick attenuating media. Finally, a proposal for ENDF-compatible formats that describe each of the models and

  16. Measurements of beta ray spectra inside nuclear generating stations using a silicon detector coincidence telescope: skin dose beta correction factors for TL elements

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S.; Weizmann, Y. [Ben Gurion University of the Negev (Israel); Hirning, C.R. [Ontario Hydro, Whitby (Canada). Health Physics

    1996-10-01

    The measurement of beta ray spectra at various work locations inside nuclear generating stations operated by Ontario Hydro is described. The measurements were carried out using an advanced coincidence telescope spectrometer using silicon detectors only. The spectrometer is capable of measuring electron energies over the range 70-2500 keV with close to 100% efficiency. Over 40 beta ray spectra were measured at various work locations in three nuclear generating stations. Photon rejection is carried out by requiring a coincidence between either two or three detectors. Monte Carlo calculations were then used to estimate beta correction factors for the LiF:Mg,Ti elements used in the Ontario Hydro thermoluminescence dosemeters. Averaging over all the measured beta correction factors for the `skin chip (100 mg. cm{sup -2}) results in a value of 2.73 {+-} 0.77 and for the extremity dosemeter (240 mg.cm{sup -2}) an average value of 4.42 {+-} 1.17 is obtained. These values are 57% and 120% greater, respectively, than the current values used by Ontario Hydro. In addition, beta correction factors for nine representative spectra were calculated for 40 mg.cm{sup -2} and 20 mg.cm{sup -2} chips, and the results demonstrate the benefits of decreased dosemeter thickness. The average value of the beta correction factor, as well as the spread in the beta correction factor, decreases dramatically from 4.80 {+-} 2.1 (240 mg.cm{sup -2}) to 1.29 {+-} 0.1 (20mg.cm{sup -2}). (Author).

  17. Gallium Arsenide detectors for X-ray and electron (beta particle) spectroscopy

    Science.gov (United States)

    Lioliou, G.; Barnett, A. M.

    2016-11-01

    Results characterizing GaAs p+-i-n+ mesa photodiodes with a 10 μm i layer for their spectral response under illumination of X-rays and beta particles are presented. A total of 22 devices, having diameters of 200 μm and 400 μm, were electrically characterized at room temperature. All devices showed comparable characteristics with a measured leakage current ranging from 4 nA/cm2 to 67 nA/cm2 at an internal electric field of 50 kV/cm. Their unintentionally doped i layers were found to be almost fully depleted at 0 V due to their low doping density. 55Fe X-ray spectra were obtained using one 200 μm diameter device and one 400 μm diameter device. The best energy resolution (FWHM at 5.9 keV) achieved was 625 eV using the 200 μm and 740 eV using the 400 μm diameter device, respectively. Noise analysis showed that the limiting factor for the energy resolution of the system was the dielectric noise; if this noise was eliminated by better design of the front end of the readout electronics, the achievable resolution would be 250 eV. 63Ni beta particle spectra obtained using the 200 μm diameter device showed the potential utility of these detectors for electron and beta particle detection. The development of semiconductor electron spectrometers is important particularly for space plasma physics; such devices may find use in future space missions to study the plasma environment of Jupiter and Europa and the predicted electron impact excitation of water vapor plumes from Europa hypothesized as a result of recent Hubble Space Telescope (HST) UV observations.

  18. Monte Carlo calculations of monoenergetic electron depth dose distributions in LiF chips: Skin dose correction factors for beta rays

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S. [Ben Gurion Univ. of the Negev, Beersheva (Israel); Hirning, C.R. [Ontario Hydro, Whitby (Canada); Yuen, P.; Wong, P. [Chalk River Labs., Ontario (Canada)

    1994-10-01

    Monte Carlo calculations have been carried out for monoenergetic electrons from 0.1 to 4 MeV irradiating LiF chips in both perpendicular and isotropic geometry. This enabled the calculation of skin dose correction factors (beta factors) for typical beta energy spectra as measured with a beta-ray spectrometer at CANDU nuclear generating stations. The correction factors were estimated by averaging the depth dose distributions for the monoenergetic electrons over the experimentally measured beta-ray spectra. The calculations illustrate the large uncertainty in beta factors arising from the unknown angular distribution of the beta-ray radiation field and uncertainties in the shape of the beta-ray spectra below 500 keV. 28 refs., 8 figs., 2 tabs.

  19. Biological effects of electromagnetic fields.

    Science.gov (United States)

    Macrì, M. A.; Di Luzio, Sr.; Di Luzio, S.

    2002-01-01

    Nowadays, concerns about hazards from electromagnetic fields represent an alarming source for human lives in technologically developed countries. We are surrounded by electromagnetic fields everywhere we spend our working hours, rest or recreational activities. The aim of this review is to summarize the biological effects due to these fields arising from power and transmission lines, electrical cable splices, electronic devices inside our homes and work-places, distribution networks and associated devices such as cellular telephones and wireless communication tower, etc. Special care has been reserved to study the biological effects of electromagnetic fields on cell lines of the mammalian immune system about which our research group has been working for several years.

  20. The catalytic role of beta effect in barotropization processes

    CERN Document Server

    Venaille, Antoine; Griffies, S M

    2012-01-01

    The vertical structure of freely evolving, continuously stratified, quasi-geostrophic flow is investigated. We predict the final state organization, and in particular its vertical structure, using statistical mechanics and these predictions are tested against numerical simulations. The key role played by conservation laws in each layer, including the fine-grained enstrophy, is discussed. In general, the conservation laws, and in particular that enstrophy is conserved layer-wise, prevent complete barotropization, i.e., the tendency to reach the gravest vertical mode. The peculiar role of the $\\beta$-effect, i.e. of the existence of planetary vorticity gradients, is discussed. In particular, it is shown that increasing $\\beta$ increases the tendency toward barotropization through turbulent stirring. The effectiveness of barotropisation may be partly parameterized using the Rhines scale $2\\pi E_{0}^{1/4}/\\beta^{1/2}$. As this parameter decreases (beta increases) then barotropization can progress further, because...

  1. Effects of amphetamine and beta-endorphin fragments on maze performance in rats

    NARCIS (Netherlands)

    Bohus, B; de Boer, S.F.

    1990-01-01

    Fragments of beta-endorphin and amphetamine cause similar effects in some tests of maze behavior in rats. The present study served to compare the influence of amphetamine and two beta-endorphin fragments [beta-endorphin (beta E)-(2-9) and beta E-(2-16)] on maze behavior in more detail. In Experiment

  2. Coulomb effects in Fermi {beta} decay of {sup 74}Rb

    Energy Technology Data Exchange (ETDEWEB)

    Oinonen, M. [CERN, EP Div., Geneva (Switzerland)

    2003-07-01

    Coulomb effects in the {beta} decay of {sup 74}Rb have been studied at ISOLDE. The observation of the non-analog feeding in the {beta} decay allows for an estimation of the Coulomb mixing parameter {delta}{sub IM}{sup 1}. The analysis of the total Coulomb correction {delta}{sub C} is still hampered by the uncertainty in the decay energy. (orig.)

  3. X-ray lithography and small-angle X-ray scattering: a combination of techniques merging biology and materials science.

    Science.gov (United States)

    Marmiroli, B; Amenitsch, H

    2012-10-01

    The advent of micro/nanotechnology has blurred the border between biology and materials science. Miniaturization of chemical and biological assays, performed by use of micro/nanofluidics, requires both careful selection of the methods of fabrication and the development of materials designed for specific applications. This, in turn, increases the need for interdisciplinary combination of suitable microfabrication and characterisation techniques. In this review, the advantages of combining X-ray lithography, as fabrication technique, with small-angle X-ray scattering measurements will be discussed. X-ray lithography enables the limitations of small-angle X-ray scattering, specifically time resolution and sample environment, to be overcome. Small-angle X-ray scattering, on the other hand, enables investigation and, consequently, adjustment of the nanostructural morphology of microstructures and materials fabricated by X-ray lithography. Moreover, the effect of X-ray irradiation on novel materials can be determined by use of small-angle X-ray scattering. The combination of top-down and bottom-up methods to develop new functional materials and structures with potential in biology will be reported.

  4. Biological effectiveness of antiproton annihilation

    CERN Document Server

    Holzscheiter, Michael H.; Bassler, Niels; Beyer, Gerd; De Marco, John J.; Doser, Michael; Ichioka, Toshiyasu; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Møller, Søren Pape; Petersen, Jorgen; Smathers, James B.; Skarsgard, Lloyd D.; Solberg, Timothy D.; Uggerhøj, Ulrik I.; Withers, H.Rodney; Vranjes, Sanja; Wong, Michelle; Wouters, Bradly G.

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in “biological dose” in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current status of the experiment are given.

  5. Biological effectiveness of antiproton annihilation

    DEFF Research Database (Denmark)

    Holzscheiter, M.H.; Agazaryan, N.; Bassler, Niels;

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct...... measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current...

  6. Isoflavones: estrogenic activity, biological effect and bioavailability.

    Science.gov (United States)

    Vitale, Daniela Cristina; Piazza, Cateno; Melilli, Barbara; Drago, Filippo; Salomone, Salvatore

    2013-03-01

    Isoflavones are phytoestrogens with potent estrogenic activity; genistein, daidzein and glycitein are the most active isoflavones found in soy beans. Phytoestrogens have similarity in structure with the human female hormone 17-β-estradiol, which can bind to both alpha and beta estrogen receptors, and mimic the action of estrogens on target organs, thereby exerting many health benefits when used in some hormone-dependent diseases. Numerous clinical studies claim benefits of genistein and daidzein in chemoprevention of breast and prostate cancer, cardiovascular disease and osteoporosis as well as in relieving postmenopausal symptoms. The ability of isoflavones to prevent cancer and other chronic diseases largely depends on pharmacokinetic properties of these compounds, in particular absorption and distribution to the target tissue. The chemical form in which isoflavones occur is important because it influences their bioavailability and, therefore, their biological activity. Glucose-conjugated isoflavones are highly polar, water-soluble compounds. They are hardly absorbed by the intestinal epithelium and have weaker biological activities than the corresponding aglycone. Different microbial families of colon can transform glycosylated isoflavones into aglycones. Clinical studies show important differences between the aglycone and conjugated forms of genistein and daidzein. The evaluation of isoflavone metabolism and bioavailability is crucial to understanding their biological effects. Lipid-based formulations such as drug incorporation into oils, emulsions and self-microemulsifying formulations have been introduced to increase bioavailability. Complexation with cyclodextrin also represent a valid method to improve the physicochemical characteristics of these substances in order to be absorbed and distributed to target tissues. We review and discuss pharmacokinetic issues that critically influence the biological activity of isoflavones.

  7. Fabrication and biological characteristics of beta-tricalcium phosphate porous ceramic scaffolds reinforced with calcium phosphate glass.

    Science.gov (United States)

    Cai, S; Xu, G H; Yu, X Z; Zhang, W J; Xiao, Z Y; Yao, K D

    2009-01-01

    The fabrication process, compressive strength and biocompatibility of porous beta-tricalcium phosphate (beta-TCP) ceramic scaffolds reinforced with 45P(2)O(5)-22CaO-25Na(2)O-8MgO bioglass (beta-TCP/BG) were investigated for their suitability as bone engineering materials. Porous beta-TCP/BG scaffolds with macropore sizes of 200-500 muicrom were prepared by coating porous polyurethane template with beta-TCP/BG slurry. The beta-TCP/BG scaffolds showed interconnected porous structures and exhibited enhanced mechanical properties to those pure beta-TCP scaffolds. In order to assess the effects of chemical composition of this bioglass on the behavior of osteoblasts cultured in vitro, porous scaffolds were immersed in simulated body fluid (SBF) for 2 weeks, and original specimens (without soaked in SBF) seeded with MC3T3-E1 were cultured for the same period. The ability of inducing apatite crystals in simulated body fluid and the attachment of osteoblasts were examined. Results suggest that apatite agglomerates are formed on the surface of the beta-TCP/BG scaffolds and its Ca/P molar ratio is approximately 1.42. Controlling the crystallization from the beta-TCP/BG matrix could influence the releasing speed of inorganic ions and further adjust the microenvironment of the solution around the beta-TCP/BG, which could improve the interaction between osteoblasts and the scaffolds.

  8. An effective method to accurately calculate the phase space factors for $\\beta^- \\beta^-$ decay

    CERN Document Server

    Neacsu, Andrei

    2015-01-01

    Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates, and for the analysis of the associated electron angular and energy distributions. We present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.

  9. Effects of added ZnTCP on mechanical and biological properties of apatite cement

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, K.; Suzuki, K. [Okayama Univ. Dental School (Japan). Dept. of Biomaterials; Miyamoto, Y.; Toh, T.; Yuasa, T.; Nagayama, M. [Tokushima Univ. (Japan). First Dept. of Oral and Maxillofacial Surgery; Ito, A. [National Inst. for Advanced Interdisciplinary Research, MITT, Ibaragi (Japan)

    2001-07-01

    Effects of added Zn doped {beta}-tricalcium phosphate (ZnTCP) on mechanical and biological properties of apatite cement (AC) was studied. Powder X-ray diffractometer revealed that ZnTCP shows no reactivity with AC. The mechanical strength of AC decreased increasing amounts of added ZnTCP. We observed no effect on the setting time of AC when the amount of ZnTCP was 10% or less. Proliferation of the osteoblastic cells was significantly increased on the surface of AC containing 5% ZnTCP when compared with that containing no ZnTCP. In contrast, proliferation of the cells decreased on the surface of AC containing 10% ZnTCP when compared with that free from ZnTCP; indicating cytotoxity. We concluded therefore, that addition of ZnTCP to AC might be useful to enhance the osteoconductivity of AC when release of Zn{sup 2+} can be carefully regulated. (orig.)

  10. Energy-Dispersive X-Ray Diffraction Studies of the Texture in Cold-Rolled Alpha-Beta Brass

    DEFF Research Database (Denmark)

    Szpunar, J.; Gerward, L.

    1980-01-01

    It is shown that energy-dispersive X-ray diffraction can be used for simultaneous measurement of several pole figures and that the accuracy is sufficient for the determination of the crystallite orientation distribution. The method is applied to the study of the texture in Cu-43 wt % Zn duplex...... alpha-beta brass rolled to 80% reduction....

  11. Decavanadate effects in biological systems.

    Science.gov (United States)

    Aureliano, Manuel; Gândara, Ricardo M C

    2005-05-01

    Vanadium biological studies often disregarded the formation of decameric vanadate species known to interact, in vitro, with high-affinity with many proteins such as myosin and sarcoplasmic reticulum calcium pump and also to inhibit these biochemical systems involved in energy transduction. Moreover, very few in vivo animal studies involving vanadium consider the contribution of decavanadate to vanadium biological effects. Recently, it has been shown that an acute exposure to decavanadate but not to other vanadate oligomers induced oxidative stress and a different fate in vanadium intracellular accumulation. Several markers of oxidative stress analyzed on hepatic and cardiac tissue were monitored after in vivo effect of an acute exposure (12, 24 h and 7 days), to a sub-lethal concentration (5 mM; 1 mg/kg) of two vanadium solutions ("metavanadate" and "decavanadate"). It was observed that "decavanadate" promote different effects than other vanadate oligomers in catalase activity, glutathione content, lipid peroxidation, mitochondrial superoxide anion production and vanadium accumulation, whereas both solutions seem to equally depress reactive oxygen species (ROS) production as well as total intracellular reducing power. Vanadium is accumulated in mitochondria in particular when "decavanadate" is administered. These recent findings, that are now summarized, point out the decameric vanadate species contributions to in vivo and in vitro effects induced by vanadium in biological systems.

  12. Methylprednisolone does not restore biological response in multiple sclerosis patients with neutralizing antibodies against interferon-beta

    DEFF Research Database (Denmark)

    Frederiksen, J L; Sorensen, P S; Hesse, D;

    2009-01-01

    BACKGROUND AND PURPOSE: Neutralizing antibodies (NAbs) appearing during treatment with Interferon-beta (IFN-beta) reduce or abolish bioactivity and therapeutic efficacy. Initial combination therapy with methylprednisolone (MP) may reduce the frequency of NAb positive patients. We hypothesized...... that MP treatment might also reduce NAb levels and re-establish IFN-beta bioactivity in patients already NAb+, who discontinue IFN-beta therapy. METHODS: In a 6-month open-label trial, we compared monthly high-dose pulsed MP treatment in 38 Nab positive patients with 35 NAb+, MP-untreated control patients...... discontinuing any therapy or switching to glatiramer acetate. All patients were NAb+ with an absent in vivo response to IFN-beta. NAbs were measured using a cytopathic effect assay and expressed as neutralizing capacity (NC) in percentage of added IFN-beta. Bioactivity was expressed as in vivo Myxovirus...

  13. The effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients

    Directory of Open Access Journals (Sweden)

    Soleiman Mahjoub

    2007-12-01

    Full Text Available BACKGROUND: Thalassemia is the most common hereditary disease in the world. Thalassemic erythrocytes are exposed to higher oxidative stress and lipid peroxidation. The aim of this study was to investigate the effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients.
    METHODS: A prospective double-blind, placebo-controlled study of the effect of beta-carotene and vitamin E on lipid peroxidation in erythrocytes membranes was performed on 120 beta-thalassemia major patients in four groups. The patients were supplemented for 4 weeks as follows: group 1 with beta-carotene (13 mg/day, group 2 with vitamin E (550 mg/day, group 3 with beta-carotene plus vitamin E and group 4 with placebo. We prepared all capsules for 4 roups in the same shape and color. Measurements of serum beta-carotene and vitamin E were performed by high performance
    liquid chromatography. After preparation of ghost cells from blood specimens, malondialdehyde (MDA was determined as index of lipid peroxidation in erythrocytes membranes before and after treatment. RESULTS: The levels of serum beta-carotene and vitamin E were significantly lower and MDA concentrations in erythrocytes membranes were significantly higher in beta-thalassemia patients compared to controls (P<0.001. In groups that treated with vitamin supplements for 4-weeks, lipid peroxidation rates were significantly reduced after treatment (P<0.001, but in placebo group there was not significant difference (P>0.05.
    CONCLUSIONS: Our findings provide evidence that an oral treatment with beta-carotene and vitamin E can significantly reduce lipid peroxidation of erythrocytes membranes and could be useful in management of beta-thalassemia major patients. KEYWORDS: Beta-thalassemia major, beta-carotene, vitamin E, malondialdehyde, lipid peroxidation.

  14. Reproductive biology of the smooth butterfly ray Gymnura micrura.

    Science.gov (United States)

    Yokota, L; Goitein, R; Gianeti, M D; Lessa, R T P

    2012-09-01

    This study provides the first detailed information on the reproductive biology of the smooth butterfly ray Gymnura micrura. A total of 905 individuals were sampled, 377 of which were used for the reproductive study. Juveniles accounted for 75% of the sample, but all life cycle stages were present in the study area. The disc width at which 50% were mature (W(D50))was estimated at 269 and 405 mm for males and females, respectively. The W(D50V) (based on the onset of vitellogenesis) was estimated at 359 mm. Uterine fecundity (mean ±s.d. = 3·8 ± 1·3; range: 1-6) was positively correlated with female size. A 3564% gain in mean wet mass was observed from egg to full-term embryo in utero. Size at birth ranged from 135 to 175 mm W(D) (19·5 to 55·0 g), with a mean of 165·1 mm W(D) (43·3 g). The embryo sex ratio was not significantly different from 1:1. The ovaries of pregnant females were undergoing vitellogenesis during gestation, with females ready to ovulate soon after parturition. Gymnura micrura may have an asynchronous reproductive cycle, with females reproducing continuously throughout the year.

  15. Biological radiation dose from secondary particles in a Milky Way gamma-ray burst

    Science.gov (United States)

    Atri, Dimitra; Melott, Adrian L.; Karam, Andrew

    2014-07-01

    Gamma-ray bursts (GRBs) are a class of highly energetic explosions emitting radiation in a very short timescale of a few seconds and with a very narrow opening angle. Although, all GRBs observed so far are extragalactic in origin, there is a high probability of a GRB of galactic origin beaming towards the Earth in the past ~0.5 Gyr. We define the level of catastrophic damage to the biosphere as approximation 100 kJ m-2, based on Thomas et al. (2005a, b). Using results in Melott & Thomas (2011), we estimate the probability of the Earth receiving this fluence from a GRB of any type, as 87% during the last 500 Myr. Such an intense burst of gamma rays would ionize the atmosphere and deplete the ozone (O3) layer. With depleted O3, there will be an increased flux of Solar UVB on the Earth's surface with potentially harmful biological effects. In addition to the atmospheric damage, secondary particles produced by gamma ray-induced showers will reach the surface. Among all secondary particles, muons dominate the ground-level secondary particle flux (99% of the total number of particles) and are potentially of biological significance. Using the Monte Carlo simulation code CORSIKA, we modelled the air showers produced by gamma-ray primaries up to 100 GeV. We found that the number of muons produced by the electromagnetic component of hypothetical galactic GRBs significantly increases the total muon flux. However, since the muon production efficiency is extremely low for photon energies below 100 GeV, and because GRBs radiate strongly for only a very short time, we find that the biological radiation dose from secondary muons is negligible. The main mechanism of biological damage from GRBs is through Solar UVB irradiation from the loss of O3 in the upper atmosphere.

  16. Simultaneous biological removal of endosulfan (alpha+beta) and nitrates from drinking waters using wheat straw as substrate.

    Science.gov (United States)

    Aslan, Sükrü; Türkman, Ayşen

    2004-06-01

    Nitrate and endosulfan (alpha+beta) removal was studied in an upflow biological denitrification reactor packed with wheat straw as carbon source and support particles for microorganisms. While almost complete nitrate elimination and between 65% and 70% endosulfan (alpha+beta) elimination occurred when the temperature was higher than 20 degrees C; below that value, nitrate removal efficiency decreased to about 10%. Nitrate, dissolved organic carbon (DOC), and endosulfan (alpha+beta) removal efficiencies decreased considerably at 1500 microg/l endosulfan concentration in the batch experiments. Although a high removal efficiency was observed for endosulfan (alpha+beta) and nitrate in the biological denitrification continuous reactor, the effluent water could not be used for drinking purpose because of the unacceptable levels of endosulfan (alpha+beta), colour and dissolved organic content. During the continuous study, 23.4% of the initial weight of wheat straw was lost and 24 g was consumed per gram of nitrogen removed. The results of the continuous study showed that 21.3% of the endosulfan removal was achieved by adsorption onto the wheat straw and 68.2% of the endosulfan removal occurred by biological activity and the remaining portion was detected in the effluent water.

  17. Crystallization and Preliminary X-ray analysis of Human Recombinant Acid beta-glucocerebrosidase, a treatment for Gaucher's Disease

    Science.gov (United States)

    Roeber, Dana F.; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl - O - beta-D - glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme(R) (Genzyme Corporation, Cambridge, MA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is commercially available for the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. We report the crystallization and the initial diffraction analysis of Cerezyme(R). The crystals are C-centered orthorhombic, with unit-cell parameters of a = 285.0 A, b = 110.2 A, and c = 91.7 A. A 99.9 A complete data set has been collected to 2.75 A with an R(sub sym) of 8.8 %.

  18. Crystallization and preliminary X-ray analysis of recombinant human acid beta-glucocerebrosidase, a treatment for Gaucher's disease

    Science.gov (United States)

    Roeber, Dana; Achari, Aniruddha; Manavalan, Partha; Edmunds, Tim; Scott, David L.

    2003-01-01

    Acid beta-glucocerebrosidase (N-acylsphingosyl-1-O-beta-D-glucoside:glucohydrolase) is a lysosomal glycoprotein that catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide. Inadequate levels of this enzyme underly the pathophysiology of Gaucher's disease. Cerezyme (Genzyme Corporation, Cambridge, MA, USA) is a partially deglycosylated form of recombinant human acid beta-glucocerebrosidase that is used in the treatment of Gaucher patients. Although acid beta-glucocerebrosidase belongs to a large family of glycosidases, relatively little is known regarding its structural biology. Here, the crystallization and the initial diffraction analysis of Cerezyme are reported. The crystals are C-centered orthorhombic, with unit-cell parameters a = 285.0, b = 110.2, c = 91.7 A. A 99.9% complete data set has been collected to 2.75 A with an R(sym) of 8.8%.

  19. Biological radiation dose from secondary particles in a Milky Way gamma ray burst

    CERN Document Server

    Atri, Dimitra; Karam, Andrew

    2013-01-01

    Gamma ray bursts (GBRs) are a class of highly energetic explosions emitting radiation in a very short timescale of a few seconds and with a very narrow opening angle. Although, all GRBs observed so far are extragalactic in origin, there is a high probability of a GRB of galactic origin beaming towards the Earth in the past ~ 0.5 Gyr. Such an intense burst of gamma rays would ionize the atmosphere and deplete the ozone layer. With depleted ozone, there will be an increased flux of solar UVB on the Earth\\~Os surface with harmful biological effects. In addition to the atmospheric damage, secondary particles produced by gamma ray-induced showers will reach the surface. Amongst all secondary particles, muons dominate the ground-level secondary particle flux (99% of the total number of particles) and are potentially of biological significance. Using the Monte Carlo simulation code CORSIKA, we modeled the air showers produced by gamma ray primaries up to 100 GeV. We found that the number of muons produced by hypothe...

  20. 远红外线与空气负离子生物学效应及其临床应用%Far infrared ray and negative air ion biological effects and clinical application

    Institute of Scientific and Technical Information of China (English)

    温文

    2014-01-01

    文章从远红外线和空气负离子的基本概念和特征入手,分析了远红外线和空气负离子的生物学效应,并对国内外的相关临床应用做了一定的蔬理,认为远红外线主要的功效是消炎止痛、促进组织再生与修复、消毒灭菌和抑制肿瘤等;而空气负离子对呼吸系统、循环系统和神经系统疾病均有明显的疗效。%In this paper, from the basic concept and characteristics of far infrared and negative ion air start, analyzed the biological effect of far infrared and negative ion air, and related clinical application at home and abroad to do a certain sort, think the efficacy of far infrared ray is mainly anti-inflammatory pain, promoting tissue regeneration and repair, sterilizing and inhibiting tumor; while the negative air ions on the respiratory system, there is a significant effects diseases of the circulatory system and nervous system.

  1. BETAview: a digital {beta}-imaging system for dynamic studies of biological phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bertolucci, E.; Conti, M.; Mettivier, G.; Montesi, M.C. E-mail: montesi@na.infn.it; Russo, P

    2002-02-01

    We present a digital autoradiography (DAR) system, named BETAview, based on semiconductor pixel detectors and a single particle counting chip, for quantitative analysis of {beta}-emitting radioactive tracers in biological samples. The system is able to perform a real time monitoring of time-dependent biological phenomena. BETAview could be equipped either with GaAs or with Si semiconductor pixellated detectors. In this paper, we describe the results obtained with an assembly based on a Si detector, 300 {mu}m thick, segmented into 64x64 170 {mu}m size square pixels. The detector is bump-bonded to the low threshold, single particle counting chip named Medipix1, developed by a CERN-based European collaboration. The sensitive area is about 1 cm{sup 2}. Studies of background noise and detection efficiency have been performed. Moreover, time-resolved cellular uptake studies with radiolabelled molecules have been monitored. Specifically, we have followed in vivo and in real time, the [{sup 14}C]L-leucine amino acid uptake by eggs of Octopus vulgaris confirming the preliminary results of a previous paper. This opens the field of biomolecular kynetic studies with this new class of semiconductor DAR systems, whose evolution (using the Medipix2 chip, 256x256 pixels, 55 {mu}m pixel size) is soon to come.

  2. Measurements of $L_{31}, L_{3}\\alpha, L_{3}\\beta, L_{2}\\beta, L_{2} \\gamma, L_{1}\\beta, L_{1}\\gamma, L_{\\beta}, L_{\\gamma}, L_{1x}, L_{2x}$ and $L_{3x}$ X-ray production cross sections and L subshell fluorescence

    CERN Document Server

    Ertugrul, M

    2001-01-01

    The L/sub 3l/, L/sub 3 alpha /, L/sub 3 beta /, L/sub 2 beta /, L/sub 2 gamma /, L/sub 1 beta /, L/sub 1 gamma /, L/sub beta /, L/sub gamma /, L/sub 1x/, L/sub 2x/ and L/sub 3x/ X-ray production cross sections in Re, W and Ta have been measured using the 59.5 keV incident photon energy. The measurements were performed using an Am-241 radioisotope as the photon source and a Si(Li) detector. The L X-rays are resolved with a new analytical method. The obtained L/sub l/, L/sub alpha /, L /sub 3 beta /, L/sub 2 beta /, L/sub 2 gamma /, L/sub 1 beta /, L/sub 1 gamma /, L/sub beta /, L/sub gamma /, L/sub 1x/, L/sub 2x/ and L /sub 3x/ X-rays are compared with the theoretical calculations using the most reliable theoretical values of L/sub i/ (i=1, 2, 3) subshell photoionization cross sections, fluorescence yields, X-ray emission rates and Coster-Kronig transition probabilities. The results in the present paper are found to be in good agreement with the calculated values. (23 refs).

  3. Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

    Directory of Open Access Journals (Sweden)

    Ramadhan Hardani Putra

    2017-02-01

    Full Text Available Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv, treatment group 1 (with a radiation of 0.08 mSv, and treatment group 2 (with a radiation of 0.16 mSv. These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

  4. A beta-ray spectrometer based on a two-or three silicon detector coincidence telescope

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S. [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Physics; Weizman, Y. [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Physics; Hirning, C.R. [Health Physics Dept., Ontario Hydro, Whitby (Canada)

    1995-03-11

    This report describes the operation of a beta-ray energy spectrometer based on a silicon detector telescope using two or three elements. The front detector is a planar, totally-depleted, silicon surface barrier detector that is 97 {mu}m thick, the back detector is a room-temperature, lithium compensated, silicon detector that is 5000 {mu}m thick, and the intermediate detector is similar to the front detector but 72 {mu}m thick and intended to be used only in intense photon fields. The three detectors are mounted in a light-tight aluminum housing. The capability of the spectrometer to reject photons is based upon the fact that the incident photon will have a small probability of simultaneously losing detectable energy in two detectors, and an even smaller probability of losing detectable energy in all three detectors. Electrons will, however, almost always record measurable events in either the front two or all three detectors. A coincidence requirement between the detectors thus rejects photon induced events. With a 97 {mu}m thick detector the lower energy coincidence threshold is approximately 110 keV. With an ultra-thin 40 {mu}m thick front detector, and operated at 15 C, the spectrometer is capable of detecting even 60-70 keV electrons with a coincidence efficiency of 60%. The spectrometer has been used to measure beta radiation fields in CANDU reactor working environments, and the spectral information is intended to support dose algorithms for the LiF TLD chips used in the Ontario Hydro dosimetry program. (orig.).

  5. Quantum Effects in Biological Systems

    Science.gov (United States)

    Roy, Sisir

    2014-07-01

    The debates about the trivial and non-trivial effects in biological systems have drawn much attention during the last decade or so. What might these non-trivial sorts of quantum effects be? There is no consensus so far among the physicists and biologists regarding the meaning of "non-trivial quantum effects". However, there is no doubt about the implications of the challenging research into quantum effects relevant to biology such as coherent excitations of biomolecules and photosynthesis, quantum tunneling of protons, van der Waals forces, ultrafast dynamics through conical intersections, and phonon-assisted electron tunneling as the basis for our sense of smell, environment assisted transport of ions and entanglement in ion channels, role of quantum vacuum in consciousness. Several authors have discussed the non-trivial quantum effects and classified them into four broad categories: (a) Quantum life principle; (b) Quantum computing in the brain; (c) Quantum computing in genetics; and (d) Quantum consciousness. First, I will review the above developments. I will then discuss in detail the ion transport in the ion channel and the relevance of quantum theory in brain function. The ion transport in the ion channel plays a key role in information processing by the brain.

  6. Paradigm Shift in Radiation Biology/Radiation Oncology-Exploitation of the "H₂O₂ Effect" for Radiotherapy Using Low-LET (Linear Energy Transfer) Radiation such as X-rays and High-Energy Electrons.

    Science.gov (United States)

    Ogawa, Yasuhiro

    2016-02-25

    Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA), which is the critical target, as described in "Radiobiology for the Radiologist", by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer) radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the "hydrogen peroxide (H₂O₂) effect", which I propose in this review article for the first time. The mechanism of lymphocyte death via the H₂O₂ effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells) might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H₂O₂ effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H₂O₂, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H₂O₂ effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this

  7. TGF-beta1 release from biodegradable polymer microparticles: its effects on marrow stromal osteoblast function

    Science.gov (United States)

    Lu, L.; Yaszemski, M. J.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    BACKGROUND: Controlled release of transforming growth factor-beta1 (TGF-beta1) to a bone defect may be beneficial for the induction of a bone regeneration cascade. The objectives of this work were to assess the feasibility of using biodegradable polymer microparticles as carriers for controlled TGF-beta1 delivery and the effects of released TGF-beta1 on the proliferation and differentiation of marrow stromal cells in vitro. METHODS: Recombinant human TGF-beta1 was incorporated into microparticles of blends of poly(DL-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG). Fluorescein isothiocynate-labeled bovine serum albumin (FITC-BSA) was co-encapsulated as a porogen. The effects of PEG content (0, 1, or 5% by weight [wt%]) and buffer pH (3, 5, or 7.4) on the protein release kinetics and the degradation of PLGA were determined in vitro for as long as 28 days. Rat marrow stromal cells were seeded on a biodegradable poly(propylene fumarate) (PPF) substrate. The dose response and biological activity of released TGF-beta1 was determined after 3 days in culture. The effects of TGF-beta1 released from PLGA/PEG microparticles on marrow stromal cell proliferation and osteoblastic differentiation were assessed during a 21-day period. RESULTS: TGF-beta1 was encapsulated along with FITC-BSA into PLGA/PEG blend microparticles and released in a multiphasic fashion including an initial burst for as long as 28 days in vitro. Increasing the initial PEG content resulted in a decreased cumulative mass of released proteins. Aggregation of FITC-BSA occurred at lower buffer pH, which led to decreased release rates of both proteins. The degradation of PLGA was increased at higher PEG content and significantly accelerated at acidic pH conditions. Rat marrow stromal cells cultured on PPF substrates showed a dose response to TGF-beta1 released from the microparticles similar to that of added TGF-beta1, indicating that the activity of TGF-beta1 was retained during microparticle

  8. Development of beta-tricalcium phosphate/sol-gel derived bioactive glass composites: physical, mechanical, and in vitro biological evaluations.

    Science.gov (United States)

    Hesaraki, Saeed; Safari, Mojgan; Shokrgozar, Mohammad Ali

    2009-10-01

    In this study, composites of beta-tricalcium phosphate (beta-TCP) and sol gel derived bioactive glass (10, 25, and 40 wt %) based on the SiO(2)-CaO-MgO-P(2)O(5) system were prepared and sintered at 1000-1200 degrees C. The mechanical properties were investigated by measuring bending strength, Vickers hardness and fracture toughness. Structural properties were evaluated by XRD and SEM analysis, and the biological properties were studied by soaking the samples in simulated body fluid (SBF) and in contact with osteoblastic cell for viability assay. When the samples were sintered at 1200 degrees C, the mechanical strength increased, up to 34%, by increasing the amount of bioactive glass phase. In contrast, it decreased when the samples were sintered at 1000 and 1100 degrees C. The results showed that the strength could be improved up to 56% when more firing period was used. Incorporation of the bioactive glass phase into beta-TCP increased the microhardness but did not significantly change the fracture toughness. Phase analysis revealed that beta-TCP or magnesium-substituted beta-TCP was the main crystalline phase of the composites beside some calcium silicate crystallized in the bioactive glass phase. Plenty precipitation of calcium phosphate layer onto the surfaces of the beta-TCP/bioactive glass composites soaked in SBF indicated superior bioactivity of these materials compared to pure beta-TCP without any precipitation. The ability of beta-TCP/bioactive glass composites to support the growth of human osteoblastic cells was considerably better than that of pure beta-TCP. These results may be used to indicate which compositions and processing conditions can provide appropriate materials for hard tissue regeneration.

  9. Counting efficiency for radionuclides decaying by beta and gamma-ray emission; Calculo de la eficiencia de recuento de nucleidos que experimentan desintegracion beta y desexcitacion gamma simple

    Energy Technology Data Exchange (ETDEWEB)

    Grau, A.; Garcia-Torano, E.

    1988-07-01

    In this paper, counting efficiency vs figure of merit for beta and gamma-ray emitters has been computed. It is assumed that the decay scheme has only a gamma level and the beta-ray emission may be coincident with the gamma-rays or the internal-conversion electrons. The radionuclides tabulated are: 20 {sub 0}, 20{sub p}, 28{sub A}l, 35{sub p}, 41{sub A}r, 42{sub K}, 47{sub S}e, 62{sub F}e, 66{sub C}u, 81{sub G}e, 86{sub B}b, 108{sub R}u, 112{sub p}d, 121{sub S}n(Ni), 122{sub I}n, 129{sub I}, 141{sub C}e 171{sub T}m, 194{sub O}s, 2O3{sub H}g, 205{sub H}g, 210{sub p}b, 225{sub R}a, 142{sub p}r, 151{sub S}m, 244{sub A}m(m). It has been assumed that the liquid is a toluene based scintillator solution in standard glass vials containing 10 cm''3. (Author) 8 refs.

  10. Effects of the perfusion of beta-, beta2-, or beta3-adrenergic agonists or epinephrine on in situ adipose tissue lipolysis measured by microdialysis in underfed ewes.

    Science.gov (United States)

    Ferlay, A; Charret, C; Galitzky, J; Berlan, M; Chilliard, Y

    2001-02-01

    The effects of isoproterenol (ISO, a non-selective beta-agonist), terbutaline (TER, a selective beta2-agonist), CL316243 (CL, a selective beta3-agonist), and epinephrine (EPI, beta- and alpha2-agonist) on in situ lipolytic response of s.c. adipose tissue were investigated in vivo, using a microdialysis method to measure glycerol release, in 12 adult nonlactating and ovariectomized, underfed Lacaune ewes. All the adrenergic compounds were perfused for 120 min at 10(-6), 10(-5), and 10(-4) M. They had no lipolytic effect at 10(-6) M. Isoproterenol and EPI at 10(-5) and 10(-4) M enhanced, in the same way, maximal response and area under the concentration curve (AUC) of dialysate glycerol, thus suggesting that involvement of alpha2-adrenoceptors in the control of in situ lipolysis is of minor importance in underfed ewes. Terbutaline had only a slight lipolytic effect at 10(-5) M. This low effect could be due to a lower affinity of TER than of ISO for the beta2-adrenoceptors. The beta3-agonist, CL, had no lipolytic effect whatever the concentration perfused. Further studies are needed to prove the putative presence of beta3-adrenoceptors and their possible role in the ovine adipose tissue.

  11. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    Science.gov (United States)

    Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

    2012-04-01

    The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  12. Effect of fluoroquinolones on mitochondrial function in pancreatic beta cells.

    Science.gov (United States)

    Ghaly, Hany; Jörns, Anne; Rustenbeck, Ingo

    2014-02-14

    Hyper- and hypoglycaemias are known side effects of fluoroquinolone antibiotics, resulting in a number of fatalities. Fluoroquinolone-induced hypoglycaemias are due to stimulated insulin release by the inhibition of the KATP channel activity of the beta cell. Recently, it was found that fluoroquinolones were much less effective on metabolically intact beta cells than on open cell preparations. Thus the intracellular effects of gatifloxacin, moxifloxacin and ciprofloxacin were investigated by measuring NAD(P)H- and FAD-autofluorescence, the mitochondrial membrane potential, and the adenine nucleotide content of isolated pancreatic islets and beta cells. 100 μM of moxifloxacin abolished the NAD(P)H increase elicited by 20mM glucose, while gatifloxacin diminished it and ciprofloxacin had no significant effect. This pattern was also seen with islets from SUR1 Ko mice, which have no functional KATP channels. Moxifloxacin also diminished the glucose-induced decrease of FAD-fluorescence, which reflects the intramitochondrial production of reducing equivalents. Moxifloxacin, but not ciprofloxacin or gatifloxacin significantly reduced the effect of 20mM glucose on the ATP/ADP ratio. The mitochondrial hyperpolarization caused by 20mM glucose was partially antagonized by moxifloxacin, but not by ciprofloxacin or gatifloxacin. Ultrastructural analyses after 20 h tissue culture showed that all three compounds (at 10 and 100 μM) diminished the number of insulin secretory granules and that gatifloxacin and ciprofloxacin, but not moxifloxacin induced fission/fusion configurations of the beta cell mitochondria. In conclusion, fluoroquinolones affect the function of the mitochondria in pancreatic beta cells which may diminish the insulinotropic effect of KATP channel closure and contribute to the hyperglycaemic episodes.

  13. A beta ray spectrometer based on a two-, or three-element silicon detector coincidence telescope

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S.; Weizman, Y. [Ben-Gurion Univ. of the Negev, Beersheba (Israel). Dept. of Physics; Hirning, C.R. [Ontario Hydro, Whitby, ON (Canada). Health Physics Dept.

    1995-12-31

    The operation of a beta ray energy spectrometer based on a two-or three-element silicon detector telescope is described. The front detector (A) is a thin, totally depleted, silicon surface barrier detector either 40 {mu}m, 72 {mu}m or 98 {mu}m thick. The back detector (C) is a Li compensated silicon detector, 5000 {mu}m thick. An additional thin detector can be inserted between these two detectors when additional photon rejection capability is required in intense photon fields. The capability of the spectrometer to reject photons is based on the fact that incident photons will have a small probability of simultaneously losing detectable energy in two detectors and an even smaller probability of losing detectable energy in all three detectors. Electrons, however, above a low energy threshold, will always record simultaneous, events in all three detectors. The spectrometer is capable of measuring electron energies from a lower energy coincidence threshold of 70 keV with 60% efficiency increasing to 100% efficiency in the energy region between 150 keV and 2.5 MeV. (Author).

  14. Understanding the influence of MgO and SrO binary doping on the mechanical and biological properties of beta-TCP ceramics.

    Science.gov (United States)

    Banerjee, Shashwat S; Tarafder, Solaiman; Davies, Neal M; Bandyopadhyay, Amit; Bose, Susmita

    2010-10-01

    The objective of this study was to evaluate the influence of MgO and SrO doping on the mechanical and biological properties of beta-tricalcium phosphate (beta-TCP). beta-TCP was doped with two different binary compositions, 0.25 and 1.0wt.% SrO along with 1.0wt.% MgO. MgO and SrO doping increased the beta phase stability at a sintering temperature of 1250 degrees C and marginally decreased the compressive strength of beta-TCP. An in vitro cell-material interaction study, using human fetal osteoblast cells (hFOB), indicated that doped beta-TCP was non-toxic, and MgO/SrO dopants improved cell attachment and growth. beta-TCP implants doped with 1.0wt.% MgO and 1.0wt.% SrO showed good in vivo biocompatibility when tested in male Sprague-Dawley rats for 16 weeks. Histomorphology analysis indicated that MgO/SrO-doped beta-TCP promoted more osteogenesis than pure beta-TCP. In vivo osteocalcin and type I collagen assay also revealed faster bone formation in rats with doped beta-TCP implant compared to rats with pure beta-TCP implant. Low Ca(2+) concentration in the urine of rats with doped beta-TCP implant confirmed slower degradation of MgO/SrO-doped beta-TCP than pure beta-TCP.

  15. Thermoluminescence properties of undoped and Tb{sup 3+} and Ce{sup 3+} doped YAG nanophosphor under UV-, X- and {beta}-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, E. de la [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37150 (Mexico)]. E-mail: elder@foton.cio.mx; Rodriguez, R.A. [Universidad de Guadalajara, CULAGOS, Lagos de Moreno, Jal. 47460 (Mexico); Melendrez, R. [Centro de Investigacion en Fisica, Universidad de Sonora, P.O. Box 5-088, Hermosillo, Sonora 83190 (Mexico); Salas, P. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, C.P. 07730 Mexico, D.F (Mexico); Diaz-Torres, L.A. [Centro de Investigaciones en Optica, A.P. 1-948, Leon, Gto. 37150 (Mexico); Barboza-Flores, M. [Centro de Investigacion en Fisica, Universidad de Sonora, P.O. Box 5-088, Hermosillo, Sonora 83190 (Mexico)]. E-mail: mbarboza@cajeme.cifus.uson.mx

    2007-02-15

    The thermoluminescence (TL) properties of undoped, Ce{sup 3+} and Tb{sup 3+} doped Y{sub 3}Al{sub 5}O{sub 12} (YAG) nanocrystals under UV-, X- and {beta}-rays irradiation is reported. The TL signal of undoped and doped samples indicates a high sensitivity to UV-, X- and {beta}-ray irradiation. The introduction of the doping ions induces changes in the trapping processes and the TL efficiency. The results show that both undoped and doped YAG nanocrystalline phosphor present good TL efficiency as well as good dose response which qualify them as a potential UV-, X- and {beta}-ray dosimeter. A linear response under X-ray irradiation is observed for low doses level in the 0.02-1.02 {mu}Gy range and for relatively high doses level of {beta}-ray irradiation in the range from 10 to 600 Gy.

  16. Biological markers of amyloid beta-related mechanisms in Alzheimer's disease.

    LENUS (Irish Health Repository)

    Hampel, Harald

    2010-06-01

    Recent research progress has given detailed knowledge on the molecular pathogenesis of Alzheimer\\'s disease (AD), which has been translated into an intense, ongoing development of disease-modifying treatments. Most new drug candidates are targeted on inhibiting amyloid beta (Abeta) production and aggregation. In drug development, it is important to co-develop biomarkers for Abeta-related mechanisms to enable early diagnosis and patient stratification in clinical trials, and to serve as tools to identify and monitor the biochemical effect of the drug directly in patients. Biomarkers are also requested by regulatory authorities to serve as safety measurements. Molecular aberrations in the AD brain are reflected in the cerebrospinal fluid (CSF). Core CSF biomarkers include Abeta isoforms (Abeta40\\/Abeta42), soluble APP isoforms, Abeta oligomers and beta-site APP-cleaving enzyme 1 (BACE1). This article reviews recent research advances on core candidate CSF and plasma Abeta-related biomarkers, and gives a conceptual review on how to implement biomarkers in clinical trials in AD.

  17. Biological markers of amyloid beta-related mechanisms in Alzheimer's disease.

    LENUS (Irish Health Repository)

    Hampel, Harald

    2012-02-01

    Recent research progress has given detailed knowledge on the molecular pathogenesis of Alzheimer\\'s disease (AD), which has been translated into an intense, ongoing development of disease-modifying treatments. Most new drug candidates are targeted on inhibiting amyloid beta (Abeta) production and aggregation. In drug development, it is important to co-develop biomarkers for Abeta-related mechanisms to enable early diagnosis and patient stratification in clinical trials, and to serve as tools to identify and monitor the biochemical effect of the drug directly in patients. Biomarkers are also requested by regulatory authorities to serve as safety measurements. Molecular aberrations in the AD brain are reflected in the cerebrospinal fluid (CSF). Core CSF biomarkers include Abeta isoforms (Abeta40\\/Abeta42), soluble APP isoforms, Abeta oligomers and beta-site APP-cleaving enzyme 1 (BACE1). This article reviews recent research advances on core candidate CSF and plasma Abeta-related biomarkers, and gives a conceptual review on how to implement biomarkers in clinical trials in AD.

  18. Purification, crystallization and preliminary X-ray diffraction of wild-type and mutant recombinant human transforming growth factor beta-induced protein (TGFBIp).

    Science.gov (United States)

    Runager, Kasper; García-Castellanos, Raquel; Valnickova, Zuzana; Kristensen, Torsten; Nielsen, Niels Chr; Klintworth, Gordon K; Gomis-Rüth, F Xavier; Enghild, Jan J

    2009-03-01

    Transforming growth factor beta-induced protein (TGFBIp) has been linked to several corneal dystrophies as certain point mutations in the protein may give rise to a progressive accumulation of insoluble protein material in the human cornea. Little is known about the biological functions of this extracellular protein, which is expressed in various tissues throughout the human body. However, it has been found to interact with a number of extracellular matrix macromolecules such as collagens and proteoglycans. Structural information about TGFBIp might prove to be a valuable tool in the elucidation of its function and its role in corneal dystrophies caused by mutations in the TGFBI gene. A simple method for the purification of wild-type and mutant forms of recombinant human TGFBIp from human cells under native conditions is presented here. Moreover, the crystallization and preliminary X-ray analysis of TGFBIp are reported.

  19. [Biological effect of wood dust].

    Science.gov (United States)

    Maciejewska, A; Wojtczak, J; Bielichowska-Cybula, G; Domańska, A; Dutkiewicz, J; Mołocznik, A

    1993-01-01

    The biological effect of exposure to wood dust depends on its composition and the content of microorganisms which are an inherent element of the dust. The irritant and allergic effects of wood dust have been recognised for a long time. The allergic effect is caused by the wood dust of subtropical trees, e.g. western red cedar (Thuja plicata), redwood (Sequoia sempervirens), obeche (Triplochiton scleroxylon), cocabolla (Dalbergia retusa) and others. Trees growing in the European climate such as: larch (Larix), walnut (Juglans regia), oak (Quercus), beech (Fagus), pine (Pinus) cause a little less pronounced allergic effect. Occupational exposure to irritative or allergic wood dust may lead to bronchial asthma, rhinitis, alveolitis allergica, DDTS (Organic dust toxic syndrome), bronchitis, allergic dermatitis, conjunctivitis. An increased risk of adenocarcinoma of the sinonasal cavity is an important and serious problem associated with occupational exposure to wood dust. Adenocarcinoma constitutes about half of the total number of cancers induced by wood dust. An increased incidence of the squamous cell cancers can also be observed. The highest risk of cancer applies to workers of the furniture industry, particularly those dealing with machine wood processing, cabinet making and carpentry. The cancer of the upper respiratory tract develops after exposure to many kinds of wood dust. However, the wood dust of oak and beech seems to be most carcinogenic. It is assumed that exposure to wood dust can cause an increased incidence of other cancers, especially lung cancer and Hodgkin's disease. The adverse effects of microorganisms, mainly mould fungi and their metabolic products are manifested by alveolitis allergica and ODTS. These microorganisms can induce aspergillomycosis, bronchial asthma, rhinitis and allergic dermatitis.

  20. X-ray absorption spectroscopy in biological systems. Opportunities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Bovenkamp, Gudrun Lisa

    2013-05-15

    X-ray absorption spectroscopy has become more important for applications in the material sciences, geology, environmental science and biology, specifically in the field of molecular biology. The scope of this thesis is to add more experimental evidence in order to show how applicable X-ray absorption near edge structure (XANES) is to biology. Two biological systems were investigated, at the molecular level, lead uptake in plants and the effect of silver on bacteria. This investigation also included an analysis of the sensitivity of Pb L{sub 3}- and Ag L{sub 3}-XANES spectra with regard to their chemical environment. It was shown that Pb L{sub 3}- and Ag L{sub 3}-XANES spectra are sensitive to an environment with at least differences in the second coordination shell. The non-destructive and element specific properties of XANES are the key advantages that were very important for this investigation. However, in both projects the adequate selection of reference compounds, which required in some cases a chemical synthesis, was the critical factor to determine the chemical speciation and, finally, possible uptake and storage mechanisms for plants and antibacterial mechanisms of silver. The chemical environment of Pb in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel mountains in Germany was determined using both solid compounds and aqueous solutions of different ionic strength, which simulate the plant environment. The results can be interpreted in such a way that lead is sorbed on the surface of cell walls. Silver bonding as reaction with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli bacteria was determined using inorganic silver compounds and synthesized silver amino acids. Silver binds to sulfur, amine and carboxyl groups in amino acids.

  1. X-ray phase contrast imaging of biological specimens with tabletop synchrotron radiation

    CERN Document Server

    Kneip, S; Dollar, F; Bloom, M S; Chvykov, V; Kalintchenko, G; Krushelnick, K; Maksimchuk, A; Mangles, S P D; Matsuoka, T; Najmudin, Z; Palmer, C A J; Schreiber, J; Schumaker, W; Thomas, A G R; Yanovsky, V

    2011-01-01

    Since their discovery in 1896, x-rays have had a profound impact on science, medicine and technology. Here we show that the x-rays from a novel tabletop source of bright coherent synchrotron radiation can be applied to phase contrast imaging of biological specimens, yielding superior image quality and avoiding the need for scarce or expensive conventional sources.

  2. Biological effects of drilling wastes

    Energy Technology Data Exchange (ETDEWEB)

    Cranford, P. J. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2000-07-01

    An argument is made for the point of view that economic realities require that a sustainable fishery must co-exist with the offshore petroleum industry, and therefore to sustain the fishery comprehensive studies are needed to identify and minimize the impact of operational drilling wastes on fishery resources. Moreover, laboratory and field studies indicate that operational drilling platforms impact on fisheries at great distances, therefore studies should not be limited to the immediate vicinity of drilling sites. Studies on long-term exposure of resident organisms to low level contaminants and the chronic lethal and sublethal biological effects of production drilling wastes must be conducted under environmentally relevant conditions to ensure the validity of the results. Studies at the Bedford Institute of Oceanography on sea scallops (Placopecten magellanicus) shows them to be highly sensitive to impacts from drilling wastes. Results of these studies, integrated with toxicity data and information on the distribution and transport of drilling wastes have been used by regulatory agencies and industrial interests to develop scientifically sound and justifiable regulations. They also led to the development of practical, sensitive and cost-effective technologies that use resident resource species to detect environmental impacts at offshore production sites. 1 fig.

  3. Beta radiation effects in sup 1 sup 3 sup 7 Cs-substituted pollucite

    CERN Document Server

    Hess, N J; Conradson, S D; Weber, W J

    2000-01-01

    The effect of high-energy beta radiation on the long-range and local structure of sup 1 sup 3 sup 7 Cs-substituted CsAlSi sub 2 O sub 6 (pollucite) was studied by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques at the Cs K-edge. Analysis of the XRD pattern of pollucite with an absorbed dose of 10 sup 1 sup 8 beta decays/g using Rietveld analysis indicates a 0.5-1% volume expansion of the tetrahedral structure as measured at 50 K and a minor displacement of the Cs cation toward the face of one of the six-membered rings. Analysis of the real-space pair-distribution function obtained from Fourier transformation of the diffraction pattern indicates significant correlated movement of the (Si,Al)-O pairs and large static disorder between Cs-O pairs. Analysis of the Cs K-edge XAS revealed substantial contributions from the Cs atomic X-ray absorption. This likely results from the exceedingly long Cs-O bond distances in the pollucite structure, which diminish the fine structure of the XAS os...

  4. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.

    Science.gov (United States)

    Ogura, Toshihiko

    2009-08-01

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  5. Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

    DEFF Research Database (Denmark)

    Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

    1976-01-01

    Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

  6. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Susan Zappala

    Full Text Available X-ray Computed Tomography (CT is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy. However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored.

  7. Reflection Imaging X-Ray Laser Microscope (RIXRALM) and its biological applications. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, S.

    1998-07-01

    The main stimulus for the development of the proposed microscope (RIXRALM) is the possibility to view the surface and near surface structure of biological materials, such as cell membranes at much higher resolution than an optical (confocal) microscope. Although the prediction resolution of RIXRALM was lower than a Scanning Electron Microscope (SEM), the possibility to obtain images of cells (membranes) in a more natural, hydrated state and, in many cases, without staining, made the idea of a reflection X-ray microscope very attractive. The specimen can be in an H{sub 2}O saturated He atmosphere at atmospheric pressure. As the image can be obtained quickly (nsec exposure, occurring within seconds of insertion into such an environment), the cell surface can be seen in a state which is very close to its natural condition. Besides, the short exposure time eliminates the effect of motional blurring on the images. Their X-ray reflection microscope fit well in the very large gap in the size of biological objects studied in light microscopy (sub-micron size) and electron microscope (down to a few nanometers size).

  8. Detrimental effects of beta-blockers in COPD - A concern for nonselective beta-blockers

    NARCIS (Netherlands)

    van der Woude, HJ; Zaagsma, J; Postma, DS; Winter, TH; van Hulst, M; Aalbers, R

    2005-01-01

    Introduction: beta-Blockers are known to worsen FEV1 and airway hyperresponsiveness (AHR) in patients with asthma. Both characteristics determine the outcome of COPD, a disease with frequent cardiac comorbidity requiring beta-blocker treatment. Design: A double-blind, placebo-controlled, randomized,

  9. Beta-defensin-2 protein is a serum biomarker for disease activity in psoriasis and reaches biologically relevant concentrations in lesional skin.

    Directory of Open Access Journals (Sweden)

    Patrick A M Jansen

    Full Text Available BACKGROUND: Previous studies have extensively documented antimicrobial and chemotactic activities of beta-defensins. Human beta-defensin-2 (hBD-2 is strongly expressed in lesional psoriatic epidermis, and recently we have shown that high beta-defensin genomic copy number is associated with psoriasis susceptibility. It is not known, however, if biologically and pathophysiologically relevant concentrations of hBD-2 protein are present in vivo, which could support an antimicrobial and proinflammatory role of beta-defensins in lesional psoriatic epidermis. METHODOLOGY/PRINCIPAL FINDINGS: We found that systemic levels of hBD-2 showed a weak but significant correlation with beta defensin copy number in healthy controls but not in psoriasis patients with active disease. In psoriasis patients but not in atopic dermatitis patients, we found high systemic hBD-2 levels that strongly correlated with disease activity as assessed by the PASI score. Our findings suggest that systemic levels in psoriasis are largely determined by secretion from involved skin and not by genomic copy number. Modelling of the in vivo epidermal hBD-2 concentration based on the secretion rate in a reconstructed skin model for psoriatic epidermis provides evidence that epidermal hBD-2 levels in vivo are probably well above the concentrations required for in vitro antimicrobial and chemokine-like effects. CONCLUSIONS/SIGNIFICANCE: Serum hBD-2 appears to be a useful surrogate marker for disease activity in psoriasis. The discrepancy between hBD-2 levels in psoriasis and atopic dermatitis could explain the well known differences in infection rate between these two diseases.

  10. Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy.

    Science.gov (United States)

    Ogura, Toshihiko

    2010-01-01

    Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si(3)N(4)) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si(3)N(4) film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes.

  11. Application of X-ray synchrotron microscopy instrumentation in biology

    Energy Technology Data Exchange (ETDEWEB)

    Gasperini, F. M. [Medical Science Program, Fluminense Federal Univ., Niteroi (Brazil); Pereira, G. R. [Dept. of Metallurgical and Materials Engineering, Federal Univ. of Rio de Janeiro (Brazil); Granjeiro, J. M. [Molecular and Cell Biology Dept., Fluminense Federal Univ., Niteroi, Rio de Janeiro (Brazil); Calasans-Maia, M. D. [Oral Surgery Dept., Fluminense Federal Univ., Niteroi, Rio de Janeiro (Brazil); Rossi, A. M. [Biomaterials Laboratory, Brazilian Center of Physics Research, Rio de Janeiro (Brazil); Perez, C. A. [Brazilian Synchrotron Laboratory, Campinas, Sao Paulo (Brazil); Lopes, R. T.; Lima, I. [Nuclear Engineering Laboratory, Federal Univ. of Rio de Janeiro (Brazil)

    2011-07-01

    X-ray micro-fluorescence imaging technique has been used as a significant tool in order to investigate minerals contents in some kinds of materials. The aim of this study was to evaluate the elemental distribution of calcium and zinc in bone substitute materials (nano-hydroxyapatite spheres) and cortical bones through X-Ray Micro-fluorescence analysis with the increment of Synchrotron Radiation in order to evaluate the characteristics of the newly formed bone and its interface, the preexisting bone and biomaterials by the arrangement of collagen fibers and its birefringence. The elemental mapping was carried out at Brazilian Synchrotron Light Laboratory, Campinas - Sao Paulo, Brazil working at D09-XRF beam line. Based on this study, the results suggest that hydroxyapatite-based biomaterials are biocompatible, promote osteo-conduction and favored bone repair. (authors)

  12. X-ray structural analysis of the photolysis products of glycinate and. beta. -alaninate cobalt(III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Polynova, T.N.; Chuklanova, E.B.; Kramarenko, F.G.; Porai-Koshits, M.A.; Poznyak, A.L.; Pavlovskii, V.I.; Stel-mashok, V.E.

    1987-04-01

    The authors were recently able to isolate in crystalline form the intermediate products in the photolysis of various mixed glycinate Co(III) complexes, and have also lately isolated the intermediate products of the photolysis of analogous complexes containing longer chain anions, such as of amino-3-propionate and amino-4-butyrate. In order to determine the structures of these products it is necessary to analyze them by x-ray crystallography. In this paper they describe the structures of two compounds which contain cationic complexes isolated from UV irradiation (lambda = 254 nm) of aqueous solutions of (Coen/sub 2/(..beta..-ala))/sup 2 +/ and Codipy/sub 2/(gly))/sup 2 +/, respectively (en = ethylenediamine, dipy = 2,2'-dipyridine, gly = glycinate, and ..beta..-ala = alaninate). In both cases, the coordinates of all of the atoms, including hydrogen atoms, were determined.

  13. Study on the Biological Effect of Bougainvillea Induced by Co60-γ Ray%Co60-γ射线诱变宝巾(Bougainvillea)的生物学效应研究

    Institute of Scientific and Technical Information of China (English)

    陈庭; 范雅文; 刘伟

    2012-01-01

    研究宝巾品种辐射处理后VM1代的生物学效应,为宝巾的辐射育种提供理论依据.以宝巾(B.Glabra)和毛宝巾(B.Spectabilis)为材料,通过不同剂量水平的Co60-γ射线处理,研究辐射剂量与其存活率、变异率的相关性,观察记录不同剂量下诱变株的生长表现,总结主要的变异性状类型.结果表明:在一定剂量Co60-γ射线范围内,辐射剂量和宝巾品种存活率呈负相关,和变异率呈正相关;毛宝巾的剂量敏感区域在50~150 Gy,而宝巾的剂量敏感区域可能在150~200 Gy,毛宝巾的辐射敏感性要高于宝巾;建立了毛宝巾剂量与存活率的线性回归方程:y=-0.409 8x+85.176,R2 =0.989 8,并由此计算毛宝巾的半致死剂量(LD50)为86 Gy;VM1代出现的各类叶变异性状主要为叶卷曲、叶残缺、叶皱缩、黄化叶等.%This paper studied the biological effect in VM1 generation of Bougainvillea varieties treated by Co60-γ ray and provided the theoretical reference for Bougainvillea irradiation breeding. The correlations of the dose and survival was studied,as well as variation rates by different dosage levels of Co60-γ ray with B. glabra and B. spectabilis. The growth performance for the variants was observed and recorded,and then the variation character types were generalized. The results showed that there is a negative correlation between dose and survival, but a positive between dose and variation rates. The radio sensitivity for B. spectabilis is superior to B. glabra. The regression equations were built with dose and survival for B. spectabilis: y= -0. 409 8x + 85. 176,R2=0. 989 8,calculating the half a lethal dose:86 Gy. In VM1 the leaf variations mainly were characterized by curly leaf,leaf deformity and leaf shrinkage,yellowing leaf,etc.

  14. Scorpion beta-toxins and voltage-gated sodium channels: interactions and effects.

    Science.gov (United States)

    Pedraza Escalona, Martha; Possani, Lourival D

    2013-01-01

    Scorpion beta-toxins (beta-ScTxs) modify the activity of voltage-gated sodium (Nav) channels, thereby producing neurotoxic effects in diverse organisms. For this reason, beta-ScTxs are essential tools not only for discriminating among different channel sub-types but also for studying the mechanisms of channel gating and the structure-function relationship involved in this process. This review considers both the structural and the functional implications of the beta-ScTxs after they bind to their receptor sites, in accord with their classification into a) anti-mammalian beta-ScTxs, b) anti-insect selective excitatory beta-ScTxs, c) anti-insect selective depressant beta-ScTxs and d) beta-ScTxs active on both insect and mammals Nav channels. Additionally, the molecular mechanism of toxin action by the "voltage sensor trapping" model is discussed, and the systemic effects produced by these toxins are reviewed.

  15. Gyrokinetic studies of the effect of beta on drift-wave stability in NCSX

    CERN Document Server

    Baumgaertel, J A; Mikkelsen, D R; Nunami, M; Xanthopoulos, P

    2012-01-01

    The gyrokinetic turbulence code GS2 was used to investigate the effects of plasma beta on linear, collisionless ion temperature gradient (ITG) modes and trapped electron modes (TEM) in National Compact Stellarator Experiment (NCSX) geometry. Plasma beta affects stability in two ways: through the equilibrium and through magnetic fluctuations. The first was studied here by comparing ITG and TEM stability in two NCSX equilibria of differing beta values, revealing that the high beta equilibrium was marginally more stable than the low beta equilibrium in the adiabatic-electron ITG mode case. However, the high beta case had a lower kinetic-electron ITG mode critical gradient. Electrostatic and electromagnetic ITG and TEM mode growth rate dependencies on temperature gradient and density gradient were qualitatively similar. The second beta effect is demonstrated via electromagnetic ITG growth rates' dependency on GS2's beta input parameter. A linear benchmark with gyrokinetic codes GENE and GKV-X is also presented.

  16. Biological dose estimation for accidental supra-high dose gamma-ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y., E-mail: yingchen29@yahoo.com.cn [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China); Yan, X.K. [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China); Department of Radiation Safety, Beijing Institute of Nuclear and Chemical Safety, 14 Guan-cun, Dongcheng District, Beijing 100077 (China); Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K. [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China)

    2011-09-15

    To correctly estimate the biological dose of victims accidentally exposed to a very high dose of {sup 60}Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of {sup 60}Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0{sup -3}D{sup 2}. Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy {gamma}-irradiation from a supra-high dose {sup 60}Co gamma-ray accident.

  17. Effects of Shielding on Gamma Rays

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-13

    The interaction of gamma rays with matter results in an effect we call attenuation (i.e. ‘shielding’). Attenuation can dramatically alter the appearance of a spectrum. Attenuating materials may actually create features in a spectrum via x-ray fluorescence

  18. The research of biological effects induced by C-arm X ray acute scan%C形臂X光机急性扫描诱导的生物效应研究

    Institute of Scientific and Technical Information of China (English)

    杨博; 高宇巍; 杨澄; 李宏伟

    2014-01-01

    Objective To investigate the biological effects induced by C-arm X ray acute scan in mice.Methods 60 healthy male BALB/c mice were randomly divided into control group,single,four,eight and twelve times of C-arm X ray scan; there were 12 mice in each group.The mice were administered with different frequency of whole-body C-arm X ray scan; After 24 h of scan,malondialdehyde (MDA) and superoxide dismutase(SOD) were detected;Enzyme Linked Immuno Sorbent Assay (ELISA) was used to detect the level of IL-4 and IFN-γin serum.The apoptosis level of peripheral lymphocytes and bone marrow cells was analyzed by flow cytometry.Results Compared with control,more than eight times of scan increased MDA level by 2.39 and 3.49,but more than four times of scan decreased SOD level in thyroid by 19.23%,25.80% and 27.95%.More than four times of scan decreased the level of IFN-γ and IL-4 in the serum by 14.71% and 22.60%,22.99% and 44.05%,31.70% and 44.43%,but no influence on the ratio of IFN-γ/IL-4 was observed.More than eight and twelve times of scan increased apoptosis level in peripheral lymphocytes and bone marrow cells by 1.68,2.40 and 2.02.Conclusion Whith Multiple scan C-arm X ray changed oxidative level and immunological response.In addition,apoptosis was initiated to maintain genome stability.%目的 探讨研究C形臂X光机急性扫描对小鼠机体功能的影响.方法 健康雄性BALB/c小鼠60只随机分为对照组、单次、四次、八次和十二次扫描组,每组12只.对照组小鼠不扫描,其余组用C形臂X光机对小鼠进行全身扫描.在照射后24小时,采用生物化学方法检测小鼠甲状腺组织中超氧化物歧化酶(SOD)和丙二醛(MDA)的水平;采用酶联免疫吸附试验(ELISA)检测血清中IL-4和IFN-γ的变化;流式细胞仪检测各照射组小鼠外周血淋巴细胞和骨髓细胞的凋亡水平.结果 与对照组比较,小鼠甲状腺组织中的MDA水平在八次以上扫描后分别升高了2.39、3

  19. Spin-polarized x-ray emission of 3d transition-metal ions : A comparison via K alpha and K beta detection

    NARCIS (Netherlands)

    Wang, Xin; deGroot, F.M.F.; Cramer, SP

    1997-01-01

    This paper demonstrates that spin-polarized x-ray-excitation spectra can be obtained using K alpha emission as well as K beta lines. A spin-polarized analysis of K alpha x-ray emission and the excitation spectra by K alpha detection on a Ni compound is reported. A systematic analysis of the first-ro

  20. URODYNAMIC EFFECTS OF BETA-ADRENOBLOCKERS: NEBIVOLOL ADVANTAGES

    Directory of Open Access Journals (Sweden)

    M. P. Savenkov

    2008-01-01

    Full Text Available Aim. To compare urodynamic effects of beta-blockers with different selectivity (propranolol, metoprolol, nebivolol in patients with arterial hypertension (HT and concomitant benign prostatic hyperplasia (BPH.Material and methods. 32 patients (aged 67,5 y.o. in average with HT of 1-2 stages were involved in the study. All patients had BPH (prostate volume >40 sm3 , increase of residual urine volume with moderate or severe low urinary tract symptoms (IPSS 8-25 and reduction of maximum urine flow rate to 5-13 ml/s. The urodynamic effect of beta-blockers was estimated by changes of urination frequency and uroflowmetry indices after single taking and 14-day therapy.Results. Propranolol and metoprolol led to aggravation of urination disorders. Nebivolol resulted in soft urodilating and urostimulating effects. It led to urination improvement and reduced a risk of urodynamic disorders.Conclusion. Urodynamic effects of cardiovascular drugs should be considered by practitioners especially in treatment of elderly patients.

  1. Precise nuclear moments of {sup 13}B and the {beta}-ray angular distribution

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomo, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Matsuta, K. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Akutsu, K. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Iwakoshi, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Nakashima, Y. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Sumikama, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Ogura, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Mihara, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Fujiwara, H. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kumashiro, S. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Minamisono, K. [TRIUMF, Vancouver, B.C., V6T 2A3 (Canada); Minamisono, T. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Fukuda, M. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Miyake, M. [Cyclotron RI Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Momota, S. [Kochi University of Technology, Tosayamada, Kochi 782-8502 (Japan); Nojiri, Y. [Kochi University of Technology, Tosayamada, Kochi 782-8502 (Japan); Kitagawa, A. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan); Sasaki, M. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan); Torikoshi, M. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan); Kanazawa, M. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan); Suda, M. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan); Sato, S. [National Institute of Radiological Sciences, Inage, Chiba 263-0024 (Japan)] [and others

    2004-12-27

    The nuclear moments of {sup 13}B(I{sup {pi}} = 3/2{sup -}, T{sub 1/2} = 17.36ms) have been re-measured precisely in order to establish the spin manipulation technique for the study of the alignment correlation term in mass system A = 13. From the {beta}-NMR on {sup 13}B in Pt, the magnetic moment was determined as |{mu}({sup 13}B)| = 3.1778(5){mu}{sub N}. From the {beta}-NQR on {sup 13}B in TiO{sub 2}, the Q moment has been determined as |Q({sup 13}B)| = 36.6(8)mb. We have measured the alignment correlation term {alpha}{sub E} for {sup 13}B {beta} decay for the first time and obtained a preliminary result as {alpha}{sub -}({sup 13}B) = 0.15(12)%/MeV.

  2. Correlation Effects in Biological Networks

    Directory of Open Access Journals (Sweden)

    A.A. Bagdasaryan

    2012-06-01

    Full Text Available Review of the complex network theory is presented and classification of such networks in accordance with the main statistical characteristics is considered. For the adjacency matrix of a real neural network the shortest distances for each pair of nodes as well as the node degree distribution and cluster coefficients are calculated. Comparison of the main statistical parameters with the random network is performed, and based on this, the conclusions about the correlation phenomena in biological system are made.

  3. WHOLE CELL TOMOGRAPHY/MOLECULAR BIOLOGY/STRUCTURAL BIOLOGY: Affordable x-ray microscopy with nanoscale resolution

    Energy Technology Data Exchange (ETDEWEB)

    Evans, James E.; Blackborow, Paul; Horne, Stephen J.; Gelb, Jeff

    2013-03-01

    Biological research spans 10 orders of magnitude from angstroms to meters. While electron microscopy can reveal structural details at most of these spatial length scales, transmission electron tomography only reliably reconstructs three-dimensional (3-D) volumes of cellular material with a spatial resolution between 1-5 nm from samples less than 500 nm thick1. Most biological cells are 2-30 times thicker than this threshold, which means that a cell must be cut into consecutive slices with each slice reconstructed individually in order to approximate the contextual information of the entire cell. Fortunately, due to a larger penetration depth2, X-ray computed tomography bypasses the need to physically section a cell and enables imaging of intact cells and tissues on the micrometer or larger scale with tens to hundreds of nanometer spatial resolution. While the technique of soft x-ray microscopy has been extensively developed in synchrotron facilities, advancements in laboratory x-ray source designs now increase its accessibility by supporting commercial systems suitable for a standard laboratory. In this paper, we highlight a new commercial compact cryogenic soft x-ray microscope designed for a standard laboratory setting and explore its capabilities for mesoscopic investigations of intact prokaryotic and eukaryotic cells.

  4. Proton-Induced X-ray Emission (PIXE) Analysis and DNA-chain Break study in rat hepatocarcinogenesis: A possible chemopreventive role by combined supplementation of vanadium and beta-carotene

    OpenAIRE

    2005-01-01

    Abstract Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE) analysis was studied during a necrogenic dose (200 mg/kg of body weight) of Diethyl Nitrosamine (DENA) induced rat liver carcinogenesis. Morphological and histopathological changes were observed as an end point biomarker. Supplementation of vanadium (0.5 ppm ad libitum) in drinking water and beta-carotene in the basal diet (120 mg/Kg of body weight) were performed four ...

  5. Boundary electron and beta dosimetry-quantification of the effects of dissimilar media on absorbed dose

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, J.C.

    1991-01-01

    This work quantifies the changes effected in electron absorbed dose to a soft-tissue equivalent medium when part of this medium is replaced by a material that is not soft-tissue equivalent. That is, heterogeneous dosimetry is addressed. Radionuclides which emit beta particles are the electron sources of primary interest. They are used in brachytherapy and in nuclear medicine: for example, beta-ray applicators made with strontium-90 are employed in certain ophthalmic treatments and iodine-131 is used to test thyroid function. More recent medical procedures under development and which involve beta radionuclides include radiommunotherapy and radiation synovectomy; the first is a cancer modality and the second deals with the treatment of rheumatoid arthritis. In addition, the possibility of skin surface contamination exists whenever there is handling of radioactive material. Determination of absorbed doses in the examples of the preceding paragraph requires considering boundaries of interfaces. Whilst the Monte Carlo method can be applied to boundary calculations, for routine work such as in clinical situations, or in other circumstances where doses need to be determined quickly, analytical dosimetry would be invaluable. Unfortunately, few analytical methods for boundary beta dosimetry exist. Furthermore, the accuracy of results from both Monte Carlo and analytical methods had to be assessed. Although restricted to one radionuclide, phosphorus-32, the experimental data obtained in this work serve several purposes, one of which is to provide standards against which calculated results can be tested. The experimental data may be useful in developing analytical boundary dosimetry methodology. The first application of the experimental data is demonstrated. Results from two Monte Carlo codes and two analytical methods are compared with experimental data. Monte Carlo results compare satisfactory with experimental results for the boundaries considered.

  6. Sulfonated dyes attenuate the toxic effects of beta-amyloid in a structure-specific fashion.

    Science.gov (United States)

    Pollack, S J; Sadler, I I; Hawtin, S R; Tailor, V J; Shearman, M S

    1995-09-15

    We recently reported that several sulfate-containing glycosaminoglycans, a class of compounds associated with the beta-amyloid plaques of Alzheimer's disease, attenuate the toxic effects of beta-amyloid fragments beta 25-35 and beta 1-40. The amyloid-binding sulfonated dye Congo Red was shown to have a similar effect. Using two clonal cell lines, we now demonstrate that several sulfonated dyes attenuate beta-amyloid toxicity and that the protective effect appears specific for compounds whose sulfonate groups can interact with the beta-pleated structure of aggregated amyloid. These results suggest that by binding beta-amyloid these compounds may prevent toxic interactions of the peptide with cells.

  7. Astrophysical and Biological Implications of $\\gamma$-Ray Burst Properties

    CERN Document Server

    Scalo, J M; Scalo, John

    1999-01-01

    Combining results from Schmidt (1999) for the local cosmic rate and mean peakluminosity of gamma-ray bursts (GRBs) with recent work on the history of thecosmic star formation rate, we provide estimates for the local GRB rate perunit blue luminosity in galaxies. These values are used to examine a number ofphenomena with the following conclusions: 1) The ratio of supernova rate to GRBrate is so large that it is difficult to maintain that more than a smallfraction of neutron star or black hole-forming events produced GRBs, evenallowing for generous collimation; 2) The GRB rate is so small that it isimpossible to use these events to account for the majority of large HI holesobserved in our own and other galaxies; the expected number of holes is muchsmaller than observed; 3) Modeling the GRB events in the Milky Way as a spatialPoisson process and allowing for modest enhancement in the star formation ratedue to birth in a spiral arm, we find that the probability that the solarsystem was exposed to a fluence large e...

  8. Cytokines and beta-cell biology: from concept to clinical translation

    DEFF Research Database (Denmark)

    Donath, M.Y.; Storling, J.; Berchtold, L.A.;

    2007-01-01

    The tale of cytokines and the beta-cell is a long story, starting with in vitro discovery in 1984, evolving via descriptive and phenomenological studies to detailed mapping of the signalling pathways, gene- and protein expression patterns, molecular and biochemical effector mechanisms to in vivo...

  9. Heteroaryl Chalcones: Design, Synthesis, X-ray Crystal Structures and Biological Evaluation

    OpenAIRE

    2013-01-01

    Chalcone derivatives have attracted increasing attention due to their numerous pharmacological activities. Changes in their structures have displayed high degree of diversity that has proven to result in a broad spectrum of biological activities. The present study highlights the synthesis of some halogen substituted chalcones 3(a–i) containing the 5-chlorothiophene moiety, their X-ray crystal structures and the evaluation of possible biological activities such as antibacterial, antifungal and...

  10. X-ray Absorption Measurements on Nickel Cathode of Sodium-beta Alumina batteries: Fe-Ni-CI Chemical Associations

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Mark E.; Alvine, Kyle J.; Fulton, John L.; Lemmon, John P.; Lu, Xiaochuan; Webb-Robertson, Bobbie-Jo M.; Heald, Steve M.; Balasubramanian, Mahalingam; Mortensen, Devon R.; Seidler, Gerald T.; Hess, Nancy J.

    2014-02-01

    Sections of Na-Al-NiCl2 cathodes from sodium-beta alumina ZEBRA batteries have been characterized with X-ray fluorescence mapping, and XANES measurements to probe the microstructure, elemental correlation, and chemical speciation after voltage cycling. Cycling was performed under identical load conditions at either 240 or 280 °C operating temperature and subsequently quenched in either the charged or discharged state. X-ray fluorescence mapping and XANES measurements were made adjacent to the current collector and β"-Al2O3 solid electrolyte interfaces to detect possible gradients in chemical properties across the cathode. An FeS additive, introduced during battery synthesis, was found to be present as either Fe metal or an Fe(II) chloride in all cathode samples. X-ray fluorescence mapping reveals an operating temperature and charge-state dependent spatial correlation between Fe, Ni, and Cl concentration. XANES measurements indicate that both Ni and Fe are chemically reactive and shift between metallic and chloride phases in the charged and discharged states, respectively. However the percentage of chemically active Ni and Fe is significantly less in the cell operated at lower temperature. Additionally, the cathode appeared chemically homogeneous at the scale of our X-ray measurements.

  11. Tritium $\\beta$-decay in pionless effective field theory

    CERN Document Server

    De-Leon, Hilla; Gazit, Doron

    2016-01-01

    We calculate the $\\beta$-decay of tritium, i.e., of its $^3$H nucleus (triton), at next-to-leading order in pionless effective field theory. At this order a low-energy parameter $L_{1A}$ enters the calculation that is also relevant for a high-accuracy prediction of the solar proton-proton fusion rate. We show proper renormalization of our perturbative calculation by an analysis of the residual cutoff dependence in observables. We find that next-to-leading order corrections contribute about $1\\%$ to the triton decay Gamow-Teller strength. We show that these conclusions are insensitive to different arrangements of the effective range expansion. We use these to fix $L_{1A}$ to high accuracy, and provide reliable theoretical and experimental uncertainty estimates.

  12. Fundamental research on a cerenkov radiation sensor based on optical glass for detecting beta-rays

    Science.gov (United States)

    Kim, Jae Seok; Jang, Kyoung Won; Shin, Sang Hun; Jeon, Dayeong; Hong, Seunghan; Sim, Hyeok In; Kim, Seon Geun; Yoo, Wook Jae; Lee, Bongsoo; Moon, Joo Hyun; Park, Byung Gi

    2015-01-01

    In this study, a Cerenkov radiation sensor for detecting low-energy beta-particles was fabricated using various Cerenkov radiators such as an aerogel and CaF2-, SiO2-, and Al2O3-based optical glasses. Because the Cerenkov threshold energy (CTE) is determined by the refractive index of the Cerenkov radiator, the intensity of Cerenkov radiation varies according to the refractive indices of the Cerenkov radiators. Therefore, we measured the intensities of Cerenkov radiation induced by beta-particles generated from a radioactive isotope as a function of the refractive indices of the Cerenkov radiators. Also, the electron fluxes were calculated for various Cerenkov radiators by using a Monte Carlo N-Particle extended transport code (MCNPX) to determine the relationship between the intensities of the Cerenkov radiation and the electron fluxes.

  13. A novel biological activity of praziquantel requiring voltage-operated Ca2+ channel beta subunits: subversion of flatworm regenerative polarity.

    Directory of Open Access Journals (Sweden)

    Taisaku Nogi

    Full Text Available BACKGROUND: Approximately 200 million people worldwide harbour parasitic flatworm infections that cause schistosomiasis. A single drug-praziquantel (PZQ-has served as the mainstay pharmacotherapy for schistosome infections since the 1980s. However, the relevant in vivo target(s of praziquantel remain undefined. METHODS AND FINDINGS: Here, we provide fresh perspective on the molecular basis of praziquantel efficacy in vivo consequent to the discovery of a remarkable action of PZQ on regeneration in a species of free-living flatworm (Dugesia japonica. Specifically, PZQ caused a robust (100% penetrance and complete duplication of the entire anterior-posterior axis during flatworm regeneration to yield two-headed organisms with duplicated, integrated central nervous and organ systems. Exploiting this phenotype as a readout for proteins impacting praziquantel efficacy, we demonstrate that PZQ-evoked bipolarity was selectively ablated by in vivo RNAi of voltage-operated calcium channel (VOCC beta subunits, but not by knockdown of a VOCC alpha subunit. At higher doses of PZQ, knockdown of VOCC beta subunits also conferred resistance to PZQ in lethality assays. CONCLUSIONS: This study identifies a new biological activity of the antischistosomal drug praziquantel on regenerative polarity in a species of free-living flatworm. Ablation of the bipolar regenerative phenotype evoked by PZQ via in vivo RNAi of VOCC beta subunits provides the first genetic evidence implicating a molecular target crucial for in vivo PZQ activity and supports the 'VOCC hypothesis' of PZQ efficacy. Further, in terms of regenerative biology and Ca(2+ signaling, these data highlight a novel role for voltage-operated Ca(2+ entry in regulating in vivo stem cell differentiation and regenerative patterning.

  14. {beta}-ray Angular Distribution from Purely Nuclear Spin Aligned {sup 20}Na

    Energy Technology Data Exchange (ETDEWEB)

    Minamisono, K., E-mail: minamiso@nscl.msu.edu [NSCL/MSU (United States); Matsuta, K.; Minamisono, T. [Osaka University, Department of Physics (Japan); Levy, C. D. P. [TRIUMF (Canada); Nagatomo, T.; Ogura, M. [Osaka University, Department of Physics (Japan); Sumikama, T. [RIKEN (Japan); Behr, J. A.; Jackson, K. P. [TRIUMF (Canada); Fujiwara, H.; Mihara, M.; Fukuda, M. [Osaka University, Department of Physics (Japan)

    2004-12-15

    The alignment correlation term in the {beta}-decay angular distribution from purely nuclear spin aligned {sup 20}Na has been measured for the first time. The final objective is to test the G parity symmetry, one of the fundamental symmetry in the weak nucleon current. For artificial creation of the alignment, the knowledge of the hyperfine interaction of {sup 20}Na implanted in a single-crystal ZnO was utilized.

  15. Atualizações sobre beta-hidroxi-beta-metilbutirato: suplementação e efeitos sobre o catabolismo de proteínas New findings on beta-hydroxy-beta-methylbutyirate: supplementation and effects on the protein catabolism

    Directory of Open Access Journals (Sweden)

    Everson Araújo Nunes

    2008-04-01

    Full Text Available O beta-hidroxi-beta-metilbutirato, metabólito do aminoácido leucina, vem sendo utilizado como suplemento alimentar, em situações específicas, com o intuito de aumentar ou manter a massa isenta de gordura. Os relatos dos efeitos do beta-hidroxi-beta-metilbutirato em estudos recentes fizeram crescer as expectativas sobre sua utilização em casos patológicos. Também foram demonstrados melhores resultados, quando da sua ingestão, no treinamento de força em indivíduos iniciantes e em idosos. Em humanos o beta-hidroxi-beta-metilbutirato tem sido usado como agente anti-catabólico, e em modelos animais foi demonstrado ser eficaz em inibir a atividade de vias proteolíticas em células musculares de indivíduos caquéticos in vitro e in vivo. Os mecanismos participantes desses processos envolvem: a inibição da atividade do sistema ubiquitina proteossoma ATP-dependente, a inibição de vias de sinalização com participação da proteína quinase C-alfa e a diminuição da concentração citoplasmática do fator nuclear - kappa B livre, eventos relacionados ao decréscimo da proteólise em células musculares.The leucine metabolite beta-hydroxy-beta-methylbutyrate has been used as a nutritional supplement in specific situations to prevent losing or to increase lean mass. Recent studies showed interesting results of beta-hydroxy-beta-methylbutyrate supplementation in certain disease states. Better results have also been demonstrated when it is taken by starters or old individuals doing strength training. In humans, beta-hydroxy-beta-methylbutyrate has been used as an anticatabolic agent and in animal models it has been demonstrated to be effective in inhibiting the activity of the proteolytic pathways in muscle cells of extremely weak individuals in vivo and in vitro. The mechanisms that participate in this process involve: inhibition of the ATP-ubiquitin-proteasome pathway, inhibition of the signalization pathways involving protein kinase C

  16. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    Science.gov (United States)

    Yusuf, M.; Zhang, F.; Chen, B.; Bhartiya, A.; Cunnea, K.; Wagner, U.; Cacho-Nerin, F.; Schwenke, J.; Robinson, I. K.

    2017-01-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors’ first ptychographic reconstructions using X-rays.

  17. Procedures for cryogenic X-ray ptychographic imaging of biological samples.

    Science.gov (United States)

    Yusuf, M; Zhang, F; Chen, B; Bhartiya, A; Cunnea, K; Wagner, U; Cacho-Nerin, F; Schwenke, J; Robinson, I K

    2017-03-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  18. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    Directory of Open Access Journals (Sweden)

    M. Yusuf

    2017-03-01

    Full Text Available Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  19. Improved vacuum evaporation unit for beryllium coating for biological X-ray microanalysis.

    Science.gov (United States)

    Marshall, A T; Carde, D; Kent, M

    1985-09-01

    An improved vacuum evaporator is described for coating frozen-hydrated biological samples with beryllium for X-ray microanalysis. The evaporator permits repeated coatings without bringing the main chamber to atmospheric pressure and ambient temperature. The use of a glass sleeve in the evaporation chamber facilitates cleaning.

  20. Is the treatment effect of IFN-beta restored after the disappearance of neutralizing antibodies?

    DEFF Research Database (Denmark)

    Sorensen, P S; Koch-Henriksen, Nils; Flachs, Esben Meulengracht

    2008-01-01

    OBJECTIVE: To establish whether multiple sclerosis (MS) patients, who have lost the therapeutic effect of interferon-beta (IFN-beta) owing to neutralizing antibodies (NAbs) and subsequently revert from a NAb-positive to a NAb-negative state under continued IFN-beta-1b therapy, regain clinical...... effect after reversion. BACKGROUND: Several studies have shown that a significant proportion of patients treated with IFN-beta develop NAbs that hamper or abolish the therapeutic effect of IFN-beta. However, some patients, who become NAb-positive under treatment with IFN-beta-1b, may revert to a NAb......-positive. A patient was defined as NAb-positive after two consecutive blood tests separated by at least 6 months. Reversion to a NAb-negative state required at least two consecutive negative tests. To allow for the confounding effect of time we employed a mixed Poisson model. RESULTS: Patients who had been NAb...

  1. Two-dimensional imaging detectors for structural biology with X-ray lasers.

    Science.gov (United States)

    Denes, Peter

    2014-07-17

    Our ability to harness the advances in microelectronics over the past decade(s) for X-ray detection has resulted in significant improvements in the state of the art. Biology with X-ray free-electron lasers present daunting detector challenges: all of the photons arrive at the same time, and individual high peak power pulses must be read out shot-by-shot. Direct X-ray detection in silicon pixel detectors--monolithic or hybrid--are the standard for XFELs today. For structural biology, improvements are needed for today's 10-100 Hz XFELs, and further improvements are required for tomorrow's 10+ kHz XFELs. This article will discuss detector challenges, why they arise and ways to overcome them, along with the current state of the art.

  2. High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W. Jr. [Univ. of California, San Francisco, CA (United States)]|[Univ. of California, Davis, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States); Rothman, S.S. [Univ. of California, San Francisco, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1997-02-01

    High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

  3. Monte Carlo Models for the Production of beta-delayed Gamma Rays Following Fission of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J; Prussin, S; Descalle, M; Hall, J

    2004-02-03

    A Monte Carlo method for the estimation of {beta}-delayed {gamma}-ray spectra following fission is described that can accommodate an arbitrary time-dependent fission rate and photon collection history. The method invokes direct sampling of the independent fission yield distributions of the fissioning system, the branching ratios for decay of individual fission products and the spectral distributions for photon emission for each decay mode. Though computationally intensive, the method can provide a detailed estimate of the spectrum that would be recorded by an arbitrary spectrometer, and can prove useful in assessing the quality of evaluated data libraries, for identifying gaps in these libraries, etc. The method is illustrated by a first comparison of calculated and experimental spectra from decay of short-lived fission products following the reactions {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f). For general purpose transport calculations, where detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may be unnecessary, it is shown that an accurate and simple parameterization of a {gamma}-ray source function can be obtained. These parametrizations should provide high-quality average spectral distributions that should prove useful in calculations describing photons escaping from thick attenuating media.

  4. Proton-Induced X-ray Emission (PIXE Analysis and DNA-chain Break study in rat hepatocarcinogenesis: A possible chemopreventive role by combined supplementation of vanadium and beta-carotene

    Directory of Open Access Journals (Sweden)

    Kanjilal NB

    2005-05-01

    Full Text Available Abstract Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE analysis was studied during a necrogenic dose (200 mg/kg of body weight of Diethyl Nitrosamine (DENA induced rat liver carcinogenesis. Morphological and histopathological changes were observed as an end point biomarker. Supplementation of vanadium (0.5 ppm ad libitum in drinking water and beta-carotene in the basal diet (120 mg/Kg of body weight were performed four weeks before DENA treatment and continued till the end of the experiment (16 weeks. PIXE analysis revealed the restoration of near normal value of zinc, copper, and iron, which were substantially altered when compared to carcinogen treated groups. Supplementation of both vanadium and beta-carotene four weeks before DENA injection was found to offer significant (64.73%, P

  5. The long term effects of {sup 137}Cs {gamma}-rays and tritiated water on induction on teratogenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Shuneki [Hiroshima Univ., Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)

    2003-07-01

    The purpose of the present study is to evaluate the teratogenesis caused by {sup 137}Cs {gamma}-rays radiation and tritiated water (tritium {beta}-rays, HTO) in rats under long-term exposures. Many congenital anomalies are caused by environmental factors, and it is likely that this assessment of teratogenesis will be very important in the future. Pregnant Donryu strain rats were irradiated with {sup 137}Cs {gamma}-rays on days 9-18 of gestation. The animals were sacrificed on day 18 of gestation and the contents of each uterine horn were examined. The numbers of surviving, dead and resorbed fetuses were recorded. The surviving fetuses were examined for external and visceral malformations. Also given here is a measure of the relative biological effectiveness (RBE) of tritiated water (HTO) compared to that for {sup 137}Cs {gamma}-rays regarding the induction of developmental anomalies such as neurocristopathy in pregnant Donryu rats. Radiation exposures were approximately 0, 1, 2, 3, 4, 5 and 6 Gy for both tritiated water and {sup 137}Cs {gamma}-rays. Teratogenesis was dose dependent for both radiation groups. Our studies show that {sup 137}Cs {gamma}-rays and HTO irradiation induce similar malformations of the cardiovascular, respiratory and skeletal systems in rat fetuses. However, a number of fetuses exhibiting growth retardation, general edema, persistent atrioventricular canal, eye defects, microcephaly and craniofacial defects following maternal exposure to HTO. These include hypoplasia of the pulmonary trunk (tetralogy of Fallot), DORV, ventricular septal defect, right aortic arch, coarctation of the aorta, aberrant right subclavian artery, hypoplasia of the thymus, craniofacial anomalies, hypoplasia or incomplete lungs and trachea, as well as limb and tail malformations in HTO syndrome. These results are similar to those found in human DiGeorge syndrome, which are considered pharyngeal arch syndromes related to a cephalic neutrocristopathy. A best estimation

  6. New Scientific Pearl about Biologic Effect of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. A. Alamdaran

    2008-01-01

    Full Text Available Soon after the discovery of X-ray by Rontgen in 1895, it became evident that radiation can cause some somatic damage to tissues. The hazards of X-ray exposure were clearly known when many large hospitals had radiology departments. The greatest increased in knowledge about X-ray risks had accrued from the dropping of the two atomic bombs in Japan in 1945 and some other atomic accident. For example, among the Japanese bomb survivors from Hiroshima and Nagasaki, there have been about 400 extra cancer deaths. These were the origin of radiology personnel and people fear from radiation exposure and resistant in against simple X-ray exam (radiophobia. However, new scientific data on the effects radiation on survivors, especially about biologic effect of ionizing rays, background radiation exposure, amount of endogenous radiation, hormosis phenomenon and comparison radiation risk with other risk over lifetime are still being continuously revised and risk estimates updated. Fundamentally, this risk is much"nlower than whatever already estimated and it is insignificant in diagnostic domain. Better perception of physician from these instances help to prevent of false radiophobia and to make proper use of diagnostic and therapeutic advantages of ionizing beam.

  7. Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-[beta]-lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, N.; Toney, J.H.; Fitzgerald, P.M.D. (Merck)

    2010-07-20

    The CphA metallo-{beta}-lactamase from Aeromonas hydrophilia has been expressed, purified and crystallized by the hanging-drop vapor-diffusion method using ammonium sulfate as the precipitant. The crystals exhibit orthorhombic symmetry (P2{sub 1}2{sub 1}2), with unit-cell parameters a = 40.75, b = 42.05, c = 128.88 {angstrom}. There is one monomer in the asymmetric unit and the solvent content is estimated to be 44% by volume. A data set extending to 1.8 {angstrom} has been measured.

  8. Fourth-generation X-ray sources: some possible applications to biology.

    Science.gov (United States)

    Doniach, S

    2000-05-01

    The term 'fourth generation X-ray sources' has come to mean X-ray free-electron lasers which use multi-GeV electron beams from linear accelerators to generate X-rays by self-amplified stimulated emission when fired into long undulators. Properties of the radiation expected from such sources are reviewed briefly and two possible applications of the resulting pulsed highly collimated X-radiation to problems in biology are discussed: use of X-ray photon correlation spectroscopy to measure time correlations of atoms in protein crystals, and use of Mössbauer radiation extracted from the photon beams by resonant Bragg diffraction from (57)Fe-containing crystals, for MAD phasing of very large unit-cell biomolecular crystals and possibly for photon echo measurements.

  9. Synthesis, molecular structure (X-ray and DFT), and solution behavior of titanium 4-Acyl-5-pyrazolonates. Correlations with related antitumor beta-diketonato derivatives.

    Science.gov (United States)

    Caruso, Francesco; Pettinari, Claudio; Marchetti, Fabio; Natanti, Paolo; Phillips, Christine; Tanski, Joseph; Rossi, Miriam

    2007-09-03

    Previously reported structure-activity relationships have shown two features for effective antitumor activity of titanium beta-diketone complexes: (a) ligand asymmetry and (b) the presence of planar substitutents on the ligand. Mono- and dinuclear derivatives, studied with diffraction and DFT methods show that (a) is consistent with different Ti-O(beta-diketonato) bond lengths, which are longer than Ti-O(oxo) and Ti-O(alkoxy) ones. pi-pi features observed in dinuclear derivatives correlate with strong reactivity of related complexes with DNA and support DNA intercalation by such planar groups, in agreement with (b). Large variation for Ti-O bond lengths and Ti-O-C bond angles in the ethoxy moiety is associated with the titanium withdrawing effect and oxygen bonding s character; it is confirmed through exploration of the Cambridge crystallographic database. This ethoxy geometrical flexibility also suggests versatile accommodation in protein pockets and/or other biological targets. Electrospray ionization mass spectrometry (ESI-MS) spectra show formation of di- and trinuclear Ti-4-acyl-5-pyrazolonato cationic oligomers. Hydrolysis/oligomerization is also described by NMR results.

  10. Effects of Gamma Ray Bursts in Earth Biosphere

    CERN Document Server

    Martin, Osmel; Guimaraes, Mayrene; Penate, Liuba; Horvath, Jorge; Galante, Douglas

    2009-01-01

    We continue former work on the modeling of potential effects of Gamma Ray Bursts on Phanerozoic Earth. We focus on global biospheric effects of ozone depletion and show a first modeling of the spectral reduction of light by NO2 formed in the stratosphere. We also illustrate the current complexities involved in the prediction of how terrestrial ecosystems would respond to this kind of burst. We conclude that more biological field and laboratory data are needed to reach even moderate accuracy in this modeling

  11. Effect of Beta-Carotene on Oxidative Stress and Expression of Cardiac Connexin 43

    Energy Technology Data Exchange (ETDEWEB)

    Novo, Rosangela; Azevedo, Paula S.; Minicucci, Marcos F.; Zornoff, Leonardo A. M., E-mail: lzornoff@fmb.unesp.br; Paiva, Sergio A. R. [Faculdade de Medicina de Botucatu - Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Botucatu, SP (Brazil)

    2013-09-15

    Intervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown. Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts. Wistar rats, weighing approximately 100 g, were allocated in two groups: Control Group (n = 30), that received the diet routinely used in our laboratory, and Beta-Carotene Group (n = 28), which received beta-carotene (in crystal form, added and mixed to the diet) at a dose of 500 mg of beta carotene/kg of diet. The animals received the treatment until they reached 200-250g, when they were sacrificed. Samples of blood, liver and heart were collected to perform Western blotting and immunohistochemistry for connexin 43; morphometric studies, dosages of beta carotene by high performance liquid chromatography as well as reduced glutathione, oxidized glutathione and lipids hydroperoxides were performed by biochemical analysis. Beta-carotene was detected only in the liver of Beta-Carotene Group animals (288 ± 94.7 μg/kg). Levels of reduced/ oxidized glutathione were higher in the liver and heart of Beta-Carotene Group animals (liver - Control Group: 42.60 ± 1.62; liver - Beta-Carotene Group: 57.40 ± 5.90; p = 0.04; heart: - Control Group: 117.40 ± 1.01; heart - Beta-Carotene Group: 121.81 ± 1.32 nmol/mg protein; p = 0.03). The content of total connexin 43 was larger in Beta-Carotene Group. Beta-carotene demonstrated a positive effect, characterized by the increase of intercellular communication and improvement of anti-oxidizing defense system. In this model, mechanism does not explain the increased mortality rate observed with the beta-carotene supplementation in clinical studies.

  12. Comparative effects of three beta blockers (atenolol, metoprolol, and propranolol) on survival after acute myocardial infarction.

    Science.gov (United States)

    Gottlieb, S S; McCarter, R J

    2001-04-01

    The beneficial impact of beta blockade after an acute myocardial infarction (AMI) is clear, but beta-adrenergic blockers differ in multiple characteristics, including lipophilicity and selectivity. The impact of these factors on the effects of beta blockade is unknown. We therefore compared the effects of different beta blockers on mortality after AMI. Charts of 201,752 patients with AMI were abstracted by the Cooperative Cardiovascular Project, a quality assurance program sponsored by the Health Care Financing Administration. Of the 69,338 patients prescribed beta blockers, we compared mortality of patients receiving different beta-adrenergic blockers using the Cox proportional-hazards model accounting for multiple factors that might influence survival. The mortality rates of the 2 selective agents, metoprolol and atenolol, were virtually identical (13.5% and 13.4% 2-year mortality, respectively). Compared with metoprolol, patients discharged on propranolol had a slightly increased mortality (15.9% 2-year mortality), which may be related to undetected differences at baseline. Survival with all of the drugs was superior to the 23.9% 2-year mortality seen in patients not receiving beta blockers. Beta blockade overall was associated with a 40% improvement in survival. Although the use of beta blockade after AMI has major prognostic importance, the present study suggests that the specific beta blocker chosen will have little influence on mortality.

  13. Acid-beta-glycerophosphatase reaction products in the central nervous system mitochondria following x-ray irradiation.

    Science.gov (United States)

    Roizin, L; Orlovskaja, D; Liu, J C; Carsten, A L

    1975-06-01

    A survey of the literature to date on the enzyme histochemistry of intracellular organelles has not yielded any reference to the presence of acid phosphatase reaction products in the mammalian mitochondria of the central nervous system. A combination of Gomori's acid phosphatase mehtod, however, with standard electron microscopy has disclosed the presence of enzyme reaction products in the mitochondria of the central nervous system of rats from 2 hr to 22 weeks after x-ray irradiation, as well as in a cerebral biopsy performed on a patient affected by Huntington's chorea. No enzyme reaction products, on the other hand, were observed in serial sections that had been incubated in substrates either containing sodium fluoride or lacking in beta-glycerophosphate. The abnormal mitochondrial enzyme reaction (chemical lesion) is considered to be the consequenco of the pathologic process affecting the ultrastructural-chemical organization of the organelle.

  14. Proliferative Effect of sTRAIL on Mouse Pancreatic Beta Cells

    Directory of Open Access Journals (Sweden)

    Sevim Kahraman

    2014-09-01

    Full Text Available Beta cell loss/impairment of function appears as a significant problem in both type 1 and type 2 diabetes. TRAIL (TNF-related apoptosis-inducing ligand was recently correlated with both types of diabetes with a proposed protective effect. TRAIL was also shown to promote survival and proliferation in different cells such as vascular smooth muscle cells and human vascular endothelial cells. Recently, TRAIL was claimed to protect pancreatic beta cells against cytokine-related harm. We hypothesized a proliferative effect for TRAIL on beta cells, and used Min6 mouse pancreatic beta cell line to test our hypothesis.

  15. INS-gene mutations: from genetics and beta cell biology to clinical disease.

    Science.gov (United States)

    Liu, Ming; Sun, Jinhong; Cui, Jinqiu; Chen, Wei; Guo, Huan; Barbetti, Fabrizio; Arvan, Peter

    2015-04-01

    A growing list of insulin gene mutations causing a new form of monogenic diabetes has drawn increasing attention over the past seven years. The mutations have been identified in the untranslated regions of the insulin gene as well as the coding sequence of preproinsulin including within the signal peptide, insulin B-chain, C-peptide, insulin A-chain, and the proteolytic cleavage sites both for signal peptidase and the prohormone convertases. These mutations affect a variety of different steps of insulin biosynthesis in pancreatic beta cells. Importantly, although many of these mutations cause proinsulin misfolding with early onset autosomal dominant diabetes, some of the mutant alleles appear to engage different cellular and molecular mechanisms that underlie beta cell failure and diabetes. In this article, we review the most recent advances in the field and discuss challenges as well as potential strategies to prevent/delay the development and progression of autosomal dominant diabetes caused by INS-gene mutations. It is worth noting that although diabetes caused by INS gene mutations is rare, increasing evidence suggests that defects in the pathway of insulin biosynthesis may also be involved in the progression of more common types of diabetes. Collectively, the (pre)proinsulin mutants provide insightful molecular models to better understand the pathogenesis of all forms of diabetes in which preproinsulin processing defects, proinsulin misfolding, and ER stress are involved.

  16. Biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G. [SENES Oak Ridge Inc., Oak Ridge, TN (United States); Theodorakis, C.W.; Shugart, L.R. [Oak Ridge National Lab., Oak Ridge, TN (United States). Environmental Sciences Division

    1996-12-31

    Natural populations have always been exposed to background levels of ionizing radiation; however, with the event of the nuclear age, studies about the effects of higher-than-background levels of ionizing radiation on individuals or populations of organisms became important. Originally, concern was focused on survival after large, acute radiation doses, and numerous studies document the somatic and genetic effects of acute ionizing radiation. However, there is a growing realization that chronic long-term exposure to higher-than-background levels of environmental radiation is more likely than is large acute exposure. Less than 10% of the literature on ionizing radiation effects deals with chronic long-term effects, and very few studies involve natural populations. In 1977, mosquito fish, Gambusia affinis, were experimentally introduced into a 0,45 ha, decommissioned, radioactive waste pond where the measured dose at the sediment-water interface was 1,150 rad/year. One year later, the fecundity of the population had not changed significantly. Eighteen years later, studies of the fish showed an inverse correlation between DNA strand breakage and fecundity in the contaminated pond. More recent studies have provided evidence that genetic diversity of the fish has increased in the contaminated site. These fish also have a greater prevalence of certain DNA banding patterns. Individuals displaying these banding patterns have a higher fecundity and lower degree of DNA strand breakage than individuals with less common banding patterns. Gambusia affinis has apparently adapted to the high background radiation, successfully surviving for approximately 50 generations. 31 refs, 5 figs.

  17. Angular dependence of Ll, L $\\alpha$ , L $\\beta$ and L $\\gamma$ X-ray differential and fluorescence cross-sections for Er, Ta, W, Au, Hg and Tl

    CERN Document Server

    Demir, L; Kurucu, Y; Karabulut, A; Sahin, Y; 10.1016/S0969-806X(02)00501-7

    2003-01-01

    Ll, L alpha , L beta and L gamma X-ray differential cross-sections, fluorescence cross-sections and L/sub i/-subshell ( sigma /sub L1/, sigma /sub L2/, and sigma /sub L3/) fluorescence cross-sections were measured for Er, Ta, W, Au, Hg, and Tl at an excitation energy of 59.6 keV using a Si(Li) detector. The differential cross-sections for these elements have been measured at different angles varying from 54 degrees to 153 degrees at intervals of 9 degrees . The Ll and L alpha groups in the L X-ray lines are found to be spatially anisotropic, while those in the L beta and L gamma peaks are isotropic. Experimental and theoretical values of L X-ray fluorescence cross- sections and L/sub i/-subshell X-ray fluorescence cross-sections were compared. (20 refs).

  18. Application of X-ray fluorescence analytical techniques in phytoremediation and plant biology studies

    Science.gov (United States)

    Nečemer, Marijan; Kump, Peter; Ščančar, Janez; Jaćimović, Radojko; Simčič, Jurij; Pelicon, Primož; Budnar, Miloš; Jeran, Zvonka; Pongrac, Paula; Regvar, Marjana; Vogel-Mikuš, Katarina

    2008-11-01

    Phytoremediation is an emerging technology that employs the use of higher plants for the clean-up of contaminated environments. Progress in the field is however handicapped by limited knowledge of the biological processes involved in plant metal uptake, translocation, tolerance and plant-microbe-soil interactions; therefore a better understanding of the basic biological mechanisms involved in plant/microbe/soil/contaminant interactions would allow further optimization of phytoremediation technologies. In view of the needs of global environmental protection, it is important that in phytoremediation and plant biology studies the analytical procedures for elemental determination in plant tissues and soil should be fast and cheap, with simple sample preparation, and of adequate accuracy and reproducibility. The aim of this study was therefore to present the main characteristics, sample preparation protocols and applications of X-ray fluorescence-based analytical techniques (energy dispersive X-ray fluorescence spectrometry—EDXRF, total reflection X-ray fluorescence spectrometry—TXRF and micro-proton induced X-ray emission—micro-PIXE). Element concentrations in plant leaves from metal polluted and non-polluted sites, as well as standard reference materials, were analyzed by the mentioned techniques, and additionally by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS). The results were compared and critically evaluated in order to assess the performance and capability of X-ray fluorescence-based techniques in phytoremediation and plant biology studies. It is the EDXRF, which is recommended as suitable to be used in the analyses of a large number of samples, because it is multi-elemental, requires only simple preparation of sample material, and it is analytically comparable to the most frequently used instrumental chemical techniques. The TXRF is compatible to FAAS in sample preparation, but relative to AAS it is fast

  19. The Effect of Beta Adrenergic Blockade on Ratings of Perceived Exertion.

    Science.gov (United States)

    1984-01-01

    more favorable approach to this form of therapy can be taken by those who have ques- tioned the efficacy of using beta blockers and exercise training...also consider the effects of beta blockers on exercise prescrip- .tion. Current guidelines by the American College of Sports V% % Z..w .. - L i V % 3...differences between cardioselective and nonselective beta blockers were evaluated. RPE has been described as a useful indicator nf the relative physiological

  20. Absolute neutrino masses physics beyond SM, double beta decay and cosmic rays

    CERN Document Server

    Päs, H; P\\"as, Heinrich; Weiler, Thomas J.

    2002-01-01

    Absolute neutrino masses provide a key to physics beyond the standard model. We discuss the impact of absolute neutrinos masses on physics beyond the standard model, the experimental possibilities to determine absolute neutrinos masses, and the intriguing connection with the Z-burst model for extreme-energy cosmic rays.

  1. Phase Sensitive X-Ray Diffraction Imaging of Defects in Biological Macromolecular Crystals

    Science.gov (United States)

    Hu, Z. W.; Lai, B.; Chu, Y. S.; Cai, Z.; Mancini, D. C.; Thomas, B. R.; Chernov, A. A.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Characterization of defects and/or disorder in biological macromolecular crystals presents much greater challenges than in conventional small-molecule crystals. The lack of sufficient contrast of defects is often a limiting factor in x-ray diffraction topography of protein crystals. This has seriously hampered efforts to understand mechanisms and origins of formation of imperfections, and the role of defects as essential entities in the bulk of macromolecular crystals. In this report, we employ a phase sensitive x-ray diffraction imaging approach for augmenting the contrast of defects in protein crystals.

  2. In vitro study of intracellular IL-1beta production and beta1 integrins expression in stimulated chondrocytes--effect of rhein.

    Science.gov (United States)

    Gigant-Huselstein, C; Dumas, D; Payan, E; Muller, S; Bensoussan, D; Netter, P; Stoltz, J F

    2002-01-01

    The purpose of the present study was to investigate the intracellular IL-1beta production and beta1 integrins (alpha4/beta1 and alpha5/beta1) expression on chondrocytes. Chondroytes monolayer (human chondrosarcoma cell line HEM-C55) were incubated for 12, 24 and 48 hours in the presence of Tumor Necrosis Factor-alpha (TNF-alpha, Sigma, France) or recombinant human IL-1alpha (rh-IL1alpha, Becton Dickinson, France). After direct immunolabelling, cells were either analyzed on FACScan flow cytometer (Becton Dickinson, France), or observed under an epi-fluorescence inverted microscope equipped with the CellScan EPR optical scanning acquisition system (IPLab-Scanalytics, USA). We found that the IL-1beta mean fluorescence intensity in flow cytometry and in 3D microscopy was increased in the presence of TNF-alpha or rh-IL-1alpha, and alpha4/beta1 or alpha5/beta1 expression was higher on stimulated cells than on control cells. On the other hand, we have evaluated the in vitro effects of rhein (10(-5) M, Negma, France), an active metabolite of diacerein, on the intracellular IL-1beta and beta1 integrins expressed by stimulated or no-stimulated chondrocytes. The results indicated that rhein leads to a reduction of IL-1beta synthesis whereas a weak decrease of beta1 integrins receptors expression is observed. From this study, it seems that rhein partially reduce cytokine-induced intracellular IL-1beta production, and it has a weak action on alpha4/beta1 or alpha5/beta1 receptors.

  3. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  4. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  5. Advances in the biological effects of terahertz wave radiation

    Institute of Scientific and Technical Information of China (English)

    Li Zhao; Yan-Hui Hao; Rui-Yun Peng

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  6. Biological Effect of Magnetic Field in Mice

    Institute of Scientific and Technical Information of China (English)

    Zhao-Wei ZENG

    2005-01-01

    Objective: To study the biological effect of magnetic field in mice bodies. Method: With a piece of permanent magnet embeded in mice bodies beside the femoral artery and vein to measure the electrophoretic velocity(um/s). Result: The magnetic field in mice bodies on the experiment group that the electrophoretic velocity is faster more than control and free group.Conclusion:The magnetic field in animal's body can raise the negative electric charges on the surface of erythrocyte to improve the microcirculation, this is the biological effect of magnetic field.

  7. Islet Stellate Cells Isolated from Fibrotic Islet of Goto-Kakizaki Rats Affect Biological Behavior of Beta-Cell

    Directory of Open Access Journals (Sweden)

    Feng-Fei Li

    2016-01-01

    Full Text Available We previously isolated islet stellate cells (ISCs from healthy Wistar rat islets. In the present study, we isolated “already primed by diabetic environment” ISCs from islets of Goto-Kakizaki rats, determined the gene profile of these cells, and assessed the effects of these ISCs on beta-cell function and survival. We detected gene expression of ISCs by digital gene expression. INS-1 cell proliferation, apoptosis, and insulin production were measured after being treated with ISCs supernatant (SN. We observed the similar expression pattern of ISCs and PSCs, but 1067 differentially expressed genes. Insulin production in INS-1 cells cultured with ISC-SN was significantly reduced. The 5-ethynyl-2′-deoxyuridine-positive INS-1 cells treated with ISC-SN were decreased. Propidium iodide- (PI- positive INS-1 cells were 2.6-fold higher than those in control groups. Caspase-3 activity was increased. In conclusion, ISCs presented in fibrotic islet of GK rats might be special PSCs, which impaired beta-cell function and proliferation and increased beta-cell apoptosis.

  8. Thermodynamic study on the effects of beta-cyclodextrin inclusion with berberine.

    Science.gov (United States)

    Yu, Jun-Sheng; Wei, Fang-Di; Gao, Wei; Zhao, Chang-Chun

    2002-01-15

    The fluorescence enhancement of berberine (Berb) as a result of complex with beta-cyclodextrin (beta-CD) is investigated. The association constants of alpha-CD and beta-CD with Berb are 60 and 137 M(-1) at 20 degrees C in pH 7.20 aqueous solution. Effects of temperature on the forming inclusion complexes of beta-CD with Berb have been examined through using fluorescence titration. Enthalpy and entropy values calculated from fluorescence data are -33.7 kJ mol(-1) and 74.3 J x mol(-1) K(-1) respectively. It was found that the dielectric constant of beta-CD cavity is about 24 in a rough analogy with absolute alcohol. These results suggest that the extrusion of 'high energy water' molecules from the cavity of beta-CD and hydrophobic interaction upon the inclusion complex formation are the main forces of the inclusion reaction. Effect of pH on the association of beta-CD with Berb was also studied. Mechanism of the inclusion of beta-CD with Berb is further studied by absorption and NMR measurements. Results show that beta-CD forms a 1:1 inclusion complex with Berb.

  9. Biological effects of electric fields: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, L.E.; Phillips, R.D.

    1983-11-01

    An overview of the literature suggests tha electric-field exposure is an environmental agent/influence of relatively low potential toxicity to biological systems. Generally, many of the biological effects which have been reported are quite subtle and differences between exposed and unexposed subjects may be masked by normal biological variations. However, several recent reports indicate possibly more serious consequences from chronic exposure, emphasizing the need for more research in epidemiology and laboratory experiments. This paper presents a cursory overview of investigations on the biological consequences of exposure to ELF electromagnetic fields. Three important topics are discussed, including: 1) the general methodology of exposure experiments, including those elements which are critical for definitive studies in biological systems; 2) a brief discussion of epidemiological and clinical studies conducted to date; and 3) a somewhat more extensive examination of animal experiments representing major areas of investigation (behavior, biological rhythms, nervous and endocrine systems, bone growth and repair, cardiovascular system and blood chemistry, immunology, reproduction, growth and development mortality and pathology, cellular and membrane studies, and mutagenesis). A discussion of current concepts, possible mechanisms and future directions of research is presented. 110 references.

  10. Biological effectiveness of neutrons: Research needs

    Energy Technology Data Exchange (ETDEWEB)

    Casarett, G.W.; Braby, L.A.; Broerse, J.J.; Elkind, M.M.; Goodhead, D.T.; Oleinick, N.L.

    1994-02-01

    The goal of this report was to provide a conceptual plan for a research program that would provide a basis for determining more precisely the biological effectiveness of neutron radiation with emphasis on endpoints relevant to the protection of human health. This report presents the findings of the experts for seven particular categories of scientific information on neutron biological effectiveness. Chapter 2 examines the radiobiological mechanisms underlying the assumptions used to estimate human risk from neutrons and other radiations. Chapter 3 discusses the qualitative and quantitative models used to organize and evaluate experimental observations and to provide extrapolations where direct observations cannot be made. Chapter 4 discusses the physical principles governing the interaction of radiation with biological systems and the importance of accurate dosimetry in evaluating radiation risk and reducing the uncertainty in the biological data. Chapter 5 deals with the chemical and molecular changes underlying cellular responses and the LET dependence of these changes. Chapter 6, in turn, discusses those cellular and genetic changes which lead to mutation or neoplastic transformation. Chapters 7 and 8 examine deterministic and stochastic effects, respectively, and the data required for the prediction of such effects at different organizational levels and for the extrapolation from experimental results in animals to risks for man. Gaps and uncertainties in this data are examined relative to data required for establishing radiation protection standards for neutrons and procedures for the effective and safe use of neutron and other high-LET radiation therapy.

  11. Biological X-ray Microanalysis: The Past, Present Practices, and Future Prospects.

    Science.gov (United States)

    Echlin, Patrick

    2001-03-01

    Abrief description is given of the events surrounding the development of biological X-ray microanalysis during the last 30 years, with particular emphasis on the contribution made by research workers in Cambridge, UK. There then follows a broad review of some applications of biological X-ray microanalysis. A more detailed consideration is given to the main thrust of current procedures and applications that are, for convenience, considered as four different kinds of samples. Thin frozen dried sections which are analyzed at ambient temperatures in a transmission electron microscope (TEM); semithin frozen dried sections which are analyzed at low temperature in a scanning transmission electron microscope (STEM); thick frozen hydrated sections which are analyzed at low temperature in a scanning electron microscope (SEM), and bulk samples which are analyzed at low temperature in the same type of instrument. A brief outline is given of the advantages and disadvantages of performing low-voltage, low-temperature X-ray microanalysis on frozen hydrated bulk biological material. The article concludes with a consideration of alternative approaches to in situ analysis using either high-energy beams or visible and near-visible photons.

  12. Tritium $\\beta$-decay in chiral effective field theory

    CERN Document Server

    Baroni, A; Kievsky, A; Marcucci, L E; Schiavilla, R; Viviani, M

    2016-01-01

    We evaluate the Fermi and Gamow-Teller (GT) matrix elements in tritium \\beta-decay by including in the charge-changing weak current the corrections up to one loop recently derived in nuclear chiral effective field theory (\\chi EFT). The trinucleon wave functions are obtained from hyperspherical-harmonics solutions of the Schrodinger equation with two- and three-nucleon potentials corresponding to either \\chi EFT (the N3LO/N2LO combination) or meson-exchange phenomenology (the AV18/UIX combination). We find that contributions due to loop corrections in the axial current are, in relative terms, as large as (and in some cases, dominate) those from one-pion exchange, which nominally occur at lower order in the power counting. We also provide values for the low-energy constants multiplying the contact axial current and three-nucleon potential, required to reproduce the experimental GT matrix element and trinucleon binding energies in the N3LO/N2LO and AV18/UIX calculations.

  13. Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gumí-Audenis, B. [ESRF, The European Synchrotron, Grenoble (France); Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Carlà, F. [ESRF, The European Synchrotron, Grenoble (France); Vitorino, M. V. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Panzarella, A. [ESRF, The European Synchrotron, Grenoble (France); Porcar, L. [Institut Laue-Langevin, Grenoble (France); Boilot, M. [ORTEC, Marseille (France); Guerber, S. [CEA, LETI Grenoble (France); Bernard, P. [ESRF, The European Synchrotron, Grenoble (France); Rodrigues, M. S. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Sanz, F.; Giannotti, M. I. [Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Costa, L., E-mail: luca.costa@esrf.fr [ESRF, The European Synchrotron, Grenoble (France)

    2015-09-30

    The performance of a custom atomic force microscope for grazing-incidence X-ray experiments on hydrated soft and biological samples is presented. A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions.

  14. de Haas-van Alphen Effect, LMTO Bandstructure and Fermi Surface of beta-AuMg

    DEFF Research Database (Denmark)

    Dunsworth, A. E.; Jan, J. -P.; Skriver, Hans Lomholt

    1979-01-01

    The de Haas-van Alphen effect has been measured in the ordered alloy beta '-AuMg. The relativistic LMTO bandstructure has been calculated and predicts a Fermi surface in good agreement with experiment. Both bandstructure and Fermi surface are similar in those of other beta brasses with the same...

  15. de Haas-van Alphen Effect, LMTO Bandstructure and Fermi Surface of beta-AgMg

    DEFF Research Database (Denmark)

    Dunsworth, A. E.; Jan, J. - P.; Skriver, Hans Lomholt

    1978-01-01

    The de Haas-van Alphen effect has been measured in the ordered alloy beta '-AgMg. The relativistic LMTO bandstructure has been calculated, and predicts a Fermi surface in good agreement with experiment. Both bandstructure and Fermi surface are similar to those of other beta brasses with the same...

  16. Chronic beta-blocker treatment in patients with advanced heart failure - Effects on neurohormones

    NARCIS (Netherlands)

    Teisman, ACH; van Veldhuisen, DJ; Boomsma, F; de Kam, PJ; Pinto, YM; de Zeeuw, D; van Gilst, WH

    2000-01-01

    Background: To date, the use of beta-blockers in treating patients with chronic heart failure gains support, this since several large clinical trials reported reduced mortality after chronic beta-blockade. Part of these beneficial effects may result from inhibition of deleterious neurohormone activa

  17. Metabolic effects of beta2-agonists in relation to exercise performance

    DEFF Research Database (Denmark)

    Kalsen, Anders

    2015-01-01

    Beta2-agonists are frequently used in the treatment of asthma and exercise-induced bronchoconstriction in elite athletes. However, aside from a bronchodilatory effect, beta2-agonists have also been shown to improve exercise performance, which makes these substances subjected to misuse by elite...

  18. Effect of Addition of Cereal Based Beta-glucan on Technological and Functional Properties of Foods

    Directory of Open Access Journals (Sweden)

    Nihal Şimşekli

    2015-01-01

    Full Text Available Nowadays usage of dietary fibers in foods has been increasing duo to revealing of health benefits. Beta-glucans found especially in oats and barley, are polysaccharide and source of water-soluble dietary fiber. Positive effects of beta-glucans like healing coronary-heart disease, lowering blood cholesterol level, balancing blood sugar level and preventing obesity, made beta-glucans widespread functional food components for producing various foods. In addition to beneficial physiological effects of beta-glucans, they texturize, gelatinize, emulsify and stabilize the foods. They increase viscosity, replace fat and enhance rheological properties in cereal, meat and dairy products. They are also used to produce packing material depending on their mechanical properties and molecular weights. In this review, effects of addition of cereal based beta-glucans on technological and functional properties of various foods are revealed based on previous studies.

  19. Boundary Electron and Beta Dosimetry-Quantification of the Effects of Dissimilar Media on Absorbed Dose

    Science.gov (United States)

    Nunes, Josane C.

    1991-02-01

    This work quantifies the changes effected in electron absorbed dose to a soft-tissue equivalent medium when part of this medium is replaced by a material that is not soft -tissue equivalent. That is, heterogeneous dosimetry is addressed. Radionuclides which emit beta particles are the electron sources of primary interest. They are used in brachytherapy and in nuclear medicine: for example, beta -ray applicators made with strontium-90 are employed in certain ophthalmic treatments and iodine-131 is used to test thyroid function. More recent medical procedures under development and which involve beta radionuclides include radioimmunotherapy and radiation synovectomy; the first is a cancer modality and the second deals with the treatment of rheumatoid arthritis. In addition, the possibility of skin surface contamination exists whenever there is handling of radioactive material. Determination of absorbed doses in the examples of the preceding paragraph requires considering boundaries of interfaces. Whilst the Monte Carlo method can be applied to boundary calculations, for routine work such as in clinical situations, or in other circumstances where doses need to be determined quickly, analytical dosimetry would be invaluable. Unfortunately, few analytical methods for boundary beta dosimetry exist. Furthermore, the accuracy of results from both Monte Carlo and analytical methods has to be assessed. Although restricted to one radionuclide, phosphorus -32, the experimental data obtained in this work serve several purposes, one of which is to provide standards against which calculated results can be tested. The experimental data also contribute to the relatively sparse set of published boundary dosimetry data. At the same time, they may be useful in developing analytical boundary dosimetry methodology. The first application of the experimental data is demonstrated. Results from two Monte Carlo codes and two analytical methods, which were developed elsewhere, are compared

  20. Effect of beta-cyclodextrin nanocavity confinement on the photophysics of robinetin.

    Science.gov (United States)

    Banerjee, Anwesha; Basu, Kaushik; Sengupta, Pradeep K

    2007-12-14

    We have studied the confinement of robinetin, a therapeutically active plant flavonol, in cyclodextrin (CDx) nanocavities, using steady state and time resolved fluorescence spectroscopy. Enhanced tautomer emission (arising from excited state intramolecular proton transfer (ESIPT)) as well as dramatically blue shifted (approximately 10 nm in beta-CDx and approximately 33 nm in SHP beta-CDx) normal fluorescence observed upon addition of the beta-CDxs indicate that robinetin readily enters the doughnut-shaped hydrophobic cavity of beta-CDx where the chromone moiety is well shielded from external hydrogen bonding perturbations. Detailed analyses of the fluorescence data (emission profile, anisotropy, decay times) indicate that robinetin forms 1:1 inclusion complexes with both natural and chemically modified beta-cyclodextrins (beta-CDx and SHP beta-CDx) with affinity constant values K=195+/-17 M(-1) and 1055+/-48 M(-1) respectively, indicating the prospective utility of SHP beta-CDx in particular as an effective drug carrier. Unlike beta-CDxs, alpha-CDxs do not form inclusion complexes with robinetin. To further characterize the robinetin/beta-CDxs complexes, circular dichroism (CD) spectroscopic studies have been performed, which reveal that incorporation of robinetin molecules in the chiral environment of the beta-CDxs strongly affects the electronic transitions of robinetin leading to the occurrence of positive induced circular dichroism (ICD) bands in the near ultra-violet (UV) region. Molecular mechanics calculations show that the inclusion complex with the chromone ring inserted into the beta-CDx cavity is most favorable, in agreement with our spectroscopic data.

  1. Studies of the $\\beta$-decay of Kr and Sr nuclei on and near the N=Z line with a Total Absorption $\\gamma$-ray Spectrometer

    CERN Multimedia

    2002-01-01

    It is proposed to measure the Gamow-Teller strength distribution in the decays of $^{71-75}$Kr and $^{75,76}$Sr using a Total Absorption Gamma-ray Spectrometer (TAGS) based on a large NaI(TI) detector. The $\\gamma$-rays emitted in these decays will be detected in the TAGS in coincidence with positrons and X-rays from electron capture. Measurements of $\\beta$-delayed particles will also be performed in coincidence with the TAGS. Comparison with theoretical calculations based on the mean field approach, Tamm-Dancoff and QRPA method should allow a determination of the shapes of the ground states of these nuclei.

  2. Differential effects of irradiation with carbon ions and x-rays on macrophage function.

    Science.gov (United States)

    Conrad, Sandro; Ritter, Sylvia; Fournier, Claudia; Nixdorff, Kathryn

    2009-05-01

    Macrophages are potent elicitors of inflammatory reactions that can play both positive and negative roles in radiotherapy. While several studies have investigated the effects of X-rays or gamma-rays on macrophages, virtually no work has been done on the responses of these cells to irradiation with carbon ions. Investigations into the effects of carbon ion irradiation are of particular interest in light of the fact that this type of radiation is being used increasingly for cancer therapy. In the present investigation we compared the effects of 250 kV X-rays with those of 9.8 MeV/u carbon ions on RAW 264.7 macrophages over a wide range of radiation doses. Macrophage functions including vitality, phagocytic activity, production of the proinflammatory cytokines IL-1beta and TNFalpha and production of nitric oxide (NO) were measured. In comparison to lymphocytes and fibroblasts, macrophages showed only a small decrease in vitality after irradiation with either X-rays or carbon ions. Proinflammatory cytokines and NO were induced in macrophages by LPS but not by irradiation alone. X-rays or carbon ions had little modulating effect on LPS-induced TNFalpha production. However, LPS-induced NO increased in a dose dependent manner up to 6-fold after carbon ion irradiation, while X-ray irradiation did not have this effect. Carbon ion irradiation mediated a concomitant decrease in IL-1beta production. Carbon ions also had a greater effect than X-rays in enhancing the phagocytic activity of macrophages. These results underscore the greater potential of carbon ion irradiation with regard to radiobiological effectiveness.

  3. Metal location and thickness in a multilayered sheet by measuring K{alpha}/K{beta}, L{alpha}/L{beta} and L{alpha}/L{gamma} X-ray ratios

    Energy Technology Data Exchange (ETDEWEB)

    Cesareo, Roberto [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy)], E-mail: cesareo@uniss.it; Rizzutto, Marcia A. [Instituto de Fisica, Universidade de Sao Paulo, CEP 0558-090, Sao Paulo (Brazil)], E-mail: rizzutto@dfn.if.usp.br; Brunetti, Antonio [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy)], E-mail: brunetti@uniss.it; Rao, Donepudi V. [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy); Dept. of Physics, SIR CRR Autonomous College, Eluru, AP (India)], E-mail: donepudi_venkateswararao@rediffmail.com

    2009-09-01

    When a multilayered material is analyzed by means of energy-dispersive X-ray fluorescence analysis, then the X-ray ratios of K{alpha}/K{beta}, or L{alpha}/L{beta} and L{alpha}/L{gamma}, for an element in the multilayered material, depend on the composition and thickness of the layer in which the element is situated, and on the composition and thickness of the superimposed layer (or layers). Multilayered samples are common in archaeometry, for example, in the case of pigment layers in paintings, or in the case of gilded or silvered alloys. The latter situation is examined in detail in the present paper, with a specific reference to pre-Columbian alloys from various museums in the north of Peru.

  4. Synthesis, X-ray Structure, Spectroscopic Characterization, and Theoretical Prediction of the Structure and Electronic Spectrum of Eu(btfa)(3).bipy and an Assessment of the Effect of Fluorine as a beta-Diketone Substituent on the Ligand-Metal Energy Transfer Process.

    Science.gov (United States)

    Batista, Hélcio J.; de Andrade, Antônio V. M.; Longo, Ricardo L.; Simas, Alfredo M.; de Sá, Gilberto F.; Ito, Nao K.; Thompson, Larry C.

    1998-07-13

    The 2,2'-dipyridyl adducts of two europium beta-diketonate complexes, Eu(btfa)(3).bipy [btfa = 4,4,4-trifluoro-1-phenyl-2,4-butanedione, bipy = 2,2'-dipyridyl] and Eu(bzac)(3).bipy [bzac = 1-phenyl-2,4-butanedione], have been prepared. The crystal structure of the former with chemical formula EuC(40)H(26)O(6)N(2)F(9) has been solved by single-crystal X-ray diffraction methods. The complex crystallizes in the monoclinic space group P2(1)/n with a = 11.122(5) Å, b = 22.860(8) Å, c = 15.870(6) Å, beta = 102.62(3)(o), V = 3937(5) Å(3), and Z = 4. A single, eight-coordinate environment, which approximates a square antiprism, is found for the europium(III). The UV absorption spectra of both complexes were obtained from ethanol solutions and, in the case of Eu(btfa)(3).bipy, from a thin film. In both cases the absorption spectra are reasonably well predicted by the INDO/S-CI method using, for Eu(btfa)(3).bipy, both the X-ray data and that obtained through the SMLC/AM1 method as input geometry and, for Eu(bzac)(3).bipy, that obtained through the SMLC/AM1 method. There is a blue shift of the calculated spectra relative to the solution spectra and a slightly larger blue shift compared to the spectrum of the thin film. Both complexes are luminescent under near-UV excitation, and the spectra are in accord with the existence of a single emitting site in each. The increased quantum yield in the fluorinated complex is correlated with a decrease in the bipy-europium(III) distance, a closer match of the lowest ligand-centered triplet state (that level which is primarily responsible for the energy transfer from the ligands to the europium(III)), and the lower vibrational energy of the C-F bonds relative to the C-H bonds. In the fluorinated complex the calculations show that the lowest triplet level is primarily localized on the 2,2'-dipyridyl whereas in the nonfluorinated complex this is the second lowest triplet level.

  5. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Oliver; Weinhardt, L.; Blum, M.; Welgand, M.; Umbach, E.; Bar, M.; Heske, C.; Denlinger, J.; Chuang, Y.-D.; McKinney, W.; Hussain, Z.; Gullikson, E.; Jones, M.; Batson, P.; Nelles, B.; Follath, R.

    2009-06-11

    We present a variable line-space grating spectrometer for soft s-rays that coverst the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite is slitless design, such a resolving power can be achieved for a source spot as large as (30 x 3000) micrometers squared, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scatters (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken with 10 min.

  6. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Oliver; Weinhardt, L.; Blum, M.; Weigand, M.; Umbach, E.; Bar, M.; Heske, Clemens; Denlinger, Jonathan; Chuang, Y.-D.; McKinney, Wayne; Hussain, Zahid; Gullikson, Eric; Jones, M.; Batson, Phil; Nelles, B.; Follath, R.

    2009-03-09

    We present a variable line-space grating spectrometer for soft x-rays that covers the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite its slitless design, such a resolving power can be achieved for a source spot as large as 30x3000 mu m2, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scattering (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken within 10 min.

  7. II. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1948-05-24

    With the completion of the 184 inch cyclotron in Berkeley and the successful construction of a deflector system, it was possible to bring the 190 Mev deuteron and the 380 Mev alpha beams out into the air and to begin a study of the effects of high-energy deuteron beams by direct irradiation of biological specimens. The direct biological use of deuteron beams was attempted earlier in Berkeley by Marshak, MacLeish, and Walker in 1940. These and other investigators have been aware for some time of the potential usefulness of high energy particle beams for radio-biological studies and their suitability for biological investigations. R.R. Wilson advanced the idea of using fast proton beams to deliver radiation and intervening tissues. R.E. Zirkle pointed out that such particle beams may be focused or screened until a cross-section of the beam is small enough to study effects of irradiation under the microscope on single cells or on parts of single cells. This article gives an overview of the radiological use of high energy deuteron beams, including the following topics: potential uses of high energy particle beams; experiments on the physical properties of the beam; lethal effect of the deuteron beam on mice.

  8. Membrane protein structural biology using X-ray free electron lasers.

    Science.gov (United States)

    Neutze, Richard; Brändén, Gisela; Schertler, Gebhard F X

    2015-08-01

    Membrane protein structural biology has benefitted tremendously from access to micro-focus crystallography at synchrotron radiation sources. X-ray free electron lasers (XFELs) are linear accelerator driven X-ray sources that deliver a jump in peak X-ray brilliance of nine orders of magnitude and represent a disruptive technology with potential to dramatically change the field. Membrane proteins were amongst the first macromolecules to be studied with XFEL radiation and include proof-of-principle demonstrations of serial femtosecond crystallography (SFX), the observation that XFEL data can deliver damage free crystallographic structures, initial experiments towards recording structural information from 2D arrays of membrane proteins, and time-resolved SFX, time-resolved wide angle X-ray scattering and time-resolved X-ray emission spectroscopy studies. Conversely, serial crystallography methods are now being applied using synchrotron radiation. We believe that a context dependent choice of synchrotron or XFEL radiation will accelerate progress towards novel insights in understanding membrane protein structure and dynamics.

  9. [Biological effects of electromagnetic fields (author's transl)].

    Science.gov (United States)

    Bernhardt, J

    1979-08-01

    This résumé deals with thermal and nonthermal effects of electromagnetic fields on man. In consideration of two aspects a limitation is necessary. Firstly, there will be discussed only direct and immediate influences on biological cells and tissues, secondly, the treatment is limited to such phenomena, for which biophysical aproximations, based on experimental data, could be developed. Hazards for the human being may occur only by thermal effects within the microwave range. Regarding frequencies below approximately 30 kHz, excitation processes cannot be excluded in exceptional cases. Thermal effects are predominant, between 30 kHz and 100 kHz, before excitations can appear. Furthermore, by comparing the electrically and magnetically induced currents with the naturally flowing currents in man caused by the brain's and heart's electrical activity, a "lower boundaryline" was estimated. Regarding electric or magnetic field strengths undercutting this boundary-line, direct effects on the central nervous system may be excluded; other mechanisms should be responsible for demonstrated biological effects. The paper closes referring to some reports--presently discussed--on experimental findings of biological effects, which are observed as a result of the influence of electromagnetic fields of small field strengths.

  10. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    Science.gov (United States)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  11. The Biological Effects of Bilirubin Photoisomers.

    Science.gov (United States)

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

    2016-01-01

    Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

  12. Effects of short-hairpin RNA-inhibited {beta}-catenin expression on the growth of human multiple myeloma cells in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wenqing, E-mail: liangwenqing_1234@126.com [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Yang, Chengwei [Department of Spinal Surgery, Lanzhou General Hospital, Lanzhou Military Area Command, 333 Nanbinhe Road, Lanzhou 730050 (China); Qian, Yu [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Fu, Qiang, E-mail: chyygklwq@hotmail.com [Department of Orthopaedics, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer {beta}-Catenin expression were markedly down-regulated by CTNNB1 shRNA. Black-Right-Pointing-Pointer CTNNB1 shRNA could inhibit the proliferation of RPMI8226 cells. Black-Right-Pointing-Pointer Significantly profound apoptotic cell death in CTNNB1 shRNA cells. Black-Right-Pointing-Pointer In vivo, CTNNB1 silence led to a growth inhibition of myeloma growth. Black-Right-Pointing-Pointer c-myc and {beta}-catenin in the expression cells of cleaved caspase-3 were increased. -- Abstract: Multiple myeloma (MM) is thrombogenic as a consequence of multiple hemostatic effects. Overexpression of {beta}-catenin has been observed in several types of malignant tumors, including MM. However, the relationship between {beta}-catenin expression and MM remains unclear. In the present study, RNA interference was used to inhibit {beta}-catenin expression in RPMI8226 cells. RT-PCR and Western blotting analyses showed that {beta}-catenin mRNA and protein expression were markedly down-regulated by CTNNB1 shRNA. Western blotting showed that the protein levels of cyclin D1 and glutamine synthetase were downregulated and supported the transcriptional regulatory function of {beta}-catenin. The MTT assay showed that CTNNB1 shRNA could have significant inhibitory effects on the proliferation of RPMI8226 cells. The TOPflash reporter assay demonstrated significant downregulation after CTNNB1 shRNA transfection in RPMI8226 cells. Flow cytometric analyses also showed significantly profound apoptosis in CTNNB1 shRNA cells. We found CTNNB1 silence led to growth inhibition of MM growth in vivo. Immunohistochemical analyses showed that c-myc and {beta}-catenin were reduced in CTNNB1 shRNA tumor tissues, but that expression of cleaved caspase-3 was increased. These results show that {beta}-catenin could be a new therapeutic agent that targets the biology of MM cells.

  13. Effects of ultrasound on Transforming Growth Factor-beta genes in bone cells

    Directory of Open Access Journals (Sweden)

    J Harle

    2005-12-01

    Full Text Available Therapeutic ultrasound (US is a widely used form of biophysical stimulation that is increasingly applied to promote fracture healing. Transforming growth factor-beta (TGF-beta, which is encoded by three related but different genes, is known to play a major part in bone growth and repair. However, the effects of US on the expression of the TGF-beta genes and the physical acoustic mechanisms involved in initiating changes in gene expression in vitro, are not yet known. The present study demonstrates that US had a differential effect on these TGF-beta isoforms in a human osteoblast cell line, with the highest dose eliciting the most pronounced up-regulation of both TGF-beta1 and TGF-beta3 at 1 hour after treatment and thereafter declining. In contrast, US had no effect on TGF-beta2 expression. Fluid streaming rather than thermal effects or cavitation was found to be the most likely explanation for the gene responses observed in vitro.

  14. Direct analysis of biological samples by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Lue M, Marco P. [Unidad de Analisis Instrumental, Departamento de Quimica y Suelos, Decanato de Agronomia, Universidad Centro-occidental Lisandro Alvarado, Apartado Postal 4076, Cabudare 3023 (Venezuela)]. E-mail: luemerumarco@yahoo.es; Hernandez-Caraballo, Edwin A. [Instituto Venezolano-Andino para la Investigacion Quimica (IVAIQUIM), Facultad de Ciencias, Universidad de los Andes, Merida 5101 (Venezuela)

    2004-08-31

    The technique of total reflection X-ray fluorescence (TXRF) is well suited for the direct analysis of biological samples due to the low matrix interferences and simultaneous multi-element nature. Nevertheless, biological organic samples are frequently analysed after digestion procedures. The direct determination of analytes requires shorter analysis time, low reactive consumption and simplifies the whole analysis process. On the other hand, the biological/clinical samples are often available in minimal amounts and routine studies require the analysis of large number of samples. To overcome the difficulties associated with the analysis of organic samples, particularly of solid ones, different procedures of sample preparation and calibration to approach the direct analysis have been evaluated: (1) slurry sampling, (2) Compton peak standardization, (3) in situ microwave digestion, (4) in situ chemical modification and (5) direct analysis with internal standardization. Examples of analytical methods developed by our research group are discussed. Some of them have not been previously published, illustrating alternative strategies for coping with various problems that may be encountered in the direct analysis by total reflection X-ray fluorescence spectrometry.

  15. Effects of New Gravitational Interactions on Neutrinoless Double $\\beta$ Decay

    CERN Document Server

    Klapdor-Kleingrothaus, H V; Sarkar, U

    2000-01-01

    It has recently been proposed that violations of Lorentz invariance orviolations of the equivalence principle can be constrained from thenon-observation of neutrinoless double beta decay. We generalize this analysisto all possible new gravitational interactions and discuss briefly theconstraints for different cases.

  16. Central effects of beta-endorphins on glucose homeostasis in the conscious dog

    Energy Technology Data Exchange (ETDEWEB)

    Radosevich, P.M.; Lacy, D.B.; Brown, L.L.; Williams, P.E.; Abumrad, N.N.

    1989-02-01

    The effects of centrally administered beta-endorphins on glucose homeostasis in the conscious dog were studied. Intracerebroventricular administration of beta-endorphin (0.2 mg/h) caused a 70% increase in plasma glucose. The mechanism of the hyperglycemia was twofold: there was an early increase in glucose production and a late inhibition of glucose clearance. These changes are explained by marked increases in plasma epinephrine (30-fold) and norepinephrine (6-fold) that occurred during infusion of beta-endorphin. Central administration of beta-endorphin also resulted in increased levels of adrenocorticotropic hormone and cortisol. In addition there was an increase in plasma insulin but no increase in plasma glucagon. Intravenous administration of beta-endorphin did not alter glucose homeostasis. Intracerebroventricular administration of acetylated beta-endorphin did not perturb glucose kinetics or any of the hormones that changed during infusion of the unacetylated peptide. We conclude that beta-endorphin acts centrally to cause hyperglycemia by stimulating sympathetic outflow and the pituitary-adrenal axis. Acetylation of beta-endorphin abolishes the in vivo activity of the peptide.

  17. Effects of beta-glucan addition to a probiotic containing yogurt.

    Science.gov (United States)

    Vasiljevic, T; Kealy, T; Mishra, V K

    2007-09-01

    This study investigated the effects of addition of beta-glucan from 2 different cereal sources (oat and barley) on growth and metabolic activity of Bifidobacterium animalis ssp. lactis (Bb-12) as determined by plating on a selective medium in yogurt during prolonged cold storage. These yogurt batches were compared to unsupplemented and inulin supplemented controls. All batches were also assessed for syneresis. Oat beta-glucan addition resulted in improved probiotic viability and stability comparable to that of inulin. It also enhanced lactic and propionic acid production. The barley beta-glucan addition suppressed proteolytic activity more than that from oat. These improvements were hindered by greater syneresis caused likely by thermodynamic incompatibility. Small amplitude oscillatory measurements of acidified model mixture of beta-glucan/skim milk solids showed formation of casein gel within the beta-glucan network. Binary mixtures of beta-glucan and skim milk solids had apparent pseudoplastic and non-Newtonian behavior governed mainly by beta-glucan contribution. Above critical concentrations, the mixtures underwent phase separation with the lower phase rich in protein. The phase diagram also showed that the addition of beta-glucan may be possible at or below 0.24 w/w%.

  18. Mechanistic Effects of Calcitriol in Cancer Biology

    Directory of Open Access Journals (Sweden)

    Lorenza Díaz

    2015-06-01

    Full Text Available Besides its classical biological effects on calcium and phosphorus homeostasis, calcitriol, the active vitamin D metabolite, has a broad variety of actions including anticancer effects that are mediated either transcriptionally and/or via non-genomic pathways. In the context of cancer, calcitriol regulates the cell cycle, induces apoptosis, promotes cell differentiation and acts as anti-inflammatory factor within the tumor microenvironment. In this review, we address the different mechanisms of action involved in the antineoplastic effects of calcitriol.

  19. Characterization of GLP-1 effects on beta-cell function after meal ingestion in humans

    DEFF Research Database (Denmark)

    Ahrén, Bo; Holst, Jens Juul; Mari, Andrea

    2003-01-01

    OBJECTIVE: Glucagon-like peptide 1 (GLP-1) is an incretin that augments insulin secretion after meal intake and is developed for treatment of type 2 diabetes. As a novel therapeutic agent, characteristics of its beta-cell effects are important to establish. Previously, beta-cell effects of GLP-1...... overnight were served a breakfast (450 kcal) with intravenous infusion of saline or synthetic GLP-1 (0.75 pmol x kg(-1) x min(-1)), and beta-cell function was evaluated by estimating the relationship between glucose concentration and insulin secretion (calculated by deconvolution of C-peptide data). RESULTS...

  20. Effects of interleukin-1 beta on thyrotropin secretion and thyroid hormone uptake in cultured rat anterior pituitary cells

    NARCIS (Netherlands)

    F.W.J.S. Wassen (Frank); E.P.C.M. Moerings (Ellis); H. van Toor (Hans); E.A. de Vrey (Evelyn); G. Hennemann; M.E. Everts (Maria)

    1996-01-01

    textabstractThe effects of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha) on basal and TRH-induced TSH release, and the effects of IL-1 beta on the uptake of [125I]T3 and [125I]T4 and on nuclear binding of [125I]T3 were examined. Furthermore,

  1. 75 FR 4877 - In the Matter of Beta Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective...

    Science.gov (United States)

    2010-01-29

    ... Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective Immediately) I Beta Gamma Nuclear Radiology (BGNR) (Licensee) is the holder of medical License No. 52-25542-01, issued by the...

  2. Intergrown new zeolite beta polymorphs with interconnected 12-ring channels solved by combining electron crystallography and single-crystal X-ray diffraction

    KAUST Repository

    Yu, Zhengbao

    2012-10-09

    Two new polymorphs of zeolite beta, denoted as SU-78A and SU-78B, were synthesized by employing dicyclohexylammonium hydroxides as organic structure-directing agents. The structure was solved by combining transmission electron microscopy and single-crystal X-ray diffraction. SU-78 is an intergrowth of SU-78A and SU-78B and contains interconnected 12-ring channels in three directions. The two polymorphs are built from the same building layer, similar to that for the zeolite beta family. The layer stacking in SU-78, however, is different from those in zeolite beta polymorph A, B, and C, showing new zeolite framework topologies. SU-78 is thermally stable up to 600 °C. © 2012 American Chemical Society.

  3. Expression, purification, crystallization, and preliminary X-ray crystallographic analysis of OXA-17, an extended-spectrum {beta}-lactamase conferring severe antibiotic resistance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H., E-mail: msgjhlee@mju.ac.kr; Sohn, S. G., E-mail: sgsohn@mju.ac.kr; Jung, H. I., E-mail: jhinumber1@hanmail.net; An, Y. J., E-mail: anyj0120@hanmail.net; Lee, S. H., E-mail: sangheelee@mju.ac.kr [Myongji University, Drug Resistance Proteomics Laboratory, Department of Biological Sciences (Korea, Republic of)

    2013-07-15

    OXA-17, an extended-spectrum {beta}-lactamase (ESBL) conferring severe antibiotic resistance, hydrolytically inactivates {beta}-lactam antibiotics, inducing a lack of eradication of pathogenic bacteria by oxyimino {beta}-lactams and not helping hospital infection control. Thus, the enzyme is a potential target for developing antimicrobial agents against pathogens producing ESBLs. OXA-17 was purified and crystallized at 298 K. X-ray diffraction data from OXA-17 crystal have been collected to 1.85 A resolution using synchrotron radiation. The crystal of OXA-17 belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 48.37, b = 101.12, and c = 126.07 A. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 54.6%.

  4. Determining the Effect of Aluminum Oxide Nanoparticles on the Aggregation of Amyloid-Beta in Transgenic Caenorhabditis elegans

    Science.gov (United States)

    Patel, Suhag; Matticks, John; Howell, Carina

    2014-03-01

    The cause of Alzheimer's disease has been linked partially to genetic factors but the predicted environmental components have yet to be determined. In Alzheimer's, accumulation of amyloid-beta protein in the brain forms plaques resulting in neurodegeneration and loss of mental functions. It has been postulated that aluminum influences the aggregation of amyloid-beta. To test this hypothesis, transgenic Caenorhabditis elegans, CL2120, was used as a model organism to observe neurodegeneration in nematodes exposed to aluminum oxide nanoparticles. Behavioral testing, fluorescent staining, and fluorescence microscopy were used to test the effects of aggregation of amyloid-beta in the nervous systems of effected nematodes exposed to aluminum oxide nanoparticles. Energy-dispersive x-ray spectroscopy was used to quantify the total concentration of aluminum oxide that the worms were exposed to during the experiment. Exposure of transgenic and wild type worms to a concentration of 4 mg mL-1 aluminum oxide showed a decrease in the sinusoidal motion, as well as an infirmity of transgenic worms when compared to control worms. These results support the hypothesis that aluminum may play a role in neurodegeneration in C. elegans, and may influence and increase the progression of Alzheimer's disease. This work was supported by National Science Foundation grants DUE-1058829, DMR-0923047 DUE-0806660 and Lock Haven FPDC grants.

  5. 4D x-ray phase contrast tomography for repeatable motion of biological samples

    Science.gov (United States)

    Hoshino, Masato; Uesugi, Kentaro; Yagi, Naoto

    2016-09-01

    X-ray phase contrast tomography based on a grating interferometer was applied to fast and dynamic measurements of biological samples. To achieve this, the scanning procedure in the tomographic scan was improved. A triangle-shaped voltage signal from a waveform generator to a Piezo stage was used for the fast phase stepping in the grating interferometer. In addition, an optical fiber coupled x-ray scientific CMOS camera was used to achieve fast and highly efficient image acquisitions. These optimizations made it possible to perform an x-ray phase contrast tomographic measurement within an 8 min scan with density resolution of 2.4 mg/cm3. A maximum volume size of 13 × 13 × 6 mm3 was obtained with a single tomographic measurement with a voxel size of 6.5 μm. The scanning procedure using the triangle wave was applied to four-dimensional measurements in which highly sensitive three-dimensional x-ray imaging and a time-resolved dynamic measurement of biological samples were combined. A fresh tendon in the tail of a rat was measured under a uniaxial stretching and releasing condition. To maintain the freshness of the sample during four-dimensional phase contrast tomography, the temperature of the bathing liquid of the sample was kept below 10° using a simple cooling system. The time-resolved deformation of the tendon and each fascicle was measured with a temporal resolution of 5.7 Hz. Evaluations of cross-sectional area size, length of the axis, and mass density in the fascicle during a stretching process provided a basis for quantitative analysis of the deformation of tendon fascicle.

  6. Barbiturate bearing aroylhydrazine derivatives: Synthesis, NMR investigations, single crystal X-ray studies and biological activity

    Science.gov (United States)

    Giziroglu, Emrah; Sarikurkcu, Cengiz; Aygün, Muhittin; Basbulbul, Gamze; Soyleyici, H. Can; Firinci, Erkan; Kirkan, Bulent; Alkis, Ayse; Saylica, Tayfur; Biyik, Halil

    2016-03-01

    A series of barbituric acid aroylhydrazine derivatives have been prepared from their corresponding 1,3-dimethyl-5-acetyl barbituric acid and aroylhydrazines. All compounds have been fully characterized by using FT-IR, multinuclear NMR (1H, 13C) and Mass (MS) spectrometry. We also describe the X-ray crystal structure of 3a, which crystallizes in the monoclinic P21/n space group. The crystal structure is stabilized with infinite linear chains of dimeric units. Furthermore, all compounds were investigated for their tyrosinase inhibition, antioxidative and antimicrobial activies. The results from biological activity assays have shown that all of compounds have excellent antioxidant, significant tyrosinase inhibition and moderate antimicrobial activity.

  7. Heteroaryl Chalcones: Design, Synthesis, X-ray Crystal Structures and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2013-10-01

    Full Text Available Chalcone derivatives have attracted increasing attention due to their numerous pharmacological activities. Changes in their structures have displayed high degree of diversity that has proven to result in a broad spectrum of biological activities. The present study highlights the synthesis of some halogen substituted chalcones 3(a–i containing the 5-chlorothiophene moiety, their X-ray crystal structures and the evaluation of possible biological activities such as antibacterial, antifungal and reducing power abilities. The results indicate the tested compounds show a varied range of inhibition values against all the tested microbial strains. Compound 3c with a p-fluoro substituent on the phenyl ring exhibits elevated antimicrobial activity, whereas the compounds 3e and 3f displayed the least antimicrobial activities. The compounds 3d, 3e, 3f and 3i showed good ferric and cupric reducing abilities, and the compounds 3b and 3c showed the weakest reducing power in the series.

  8. Heteroaryl chalcones: design, synthesis, X-ray crystal structures and biological evaluation.

    Science.gov (United States)

    Kumar, C S Chidan; Loh, Wan-Sin; Ooi, Chin Wei; Quah, Ching Kheng; Fun, Hoong-Kun

    2013-10-15

    Chalcone derivatives have attracted increasing attention due to their numerous pharmacological activities. Changes in their structures have displayed high degree of diversity that has proven to result in a broad spectrum of biological activities. The present study highlights the synthesis of some halogen substituted chalcones 3(a-i) containing the 5-chlorothiophene moiety, their X-ray crystal structures and the evaluation of possible biological activities such as antibacterial, antifungal and reducing power abilities. The results indicate the tested compounds show a varied range of inhibition values against all the tested microbial strains. Compound 3c with a p-fluoro substituent on the phenyl ring exhibits elevated antimicrobial activity, whereas the compounds 3e and 3f displayed the least antimicrobial activities. The compounds 3d, 3e, 3f and 3i showed good ferric and cupric reducing abilities, and the compounds 3b and 3c showed the weakest reducing power in the series.

  9. Digital X-ray camera for quality evaluation three-dimensional topographic reconstruction of single crystals of biological macromolecules

    Science.gov (United States)

    Borgstahl, Gloria (Inventor); Lovelace, Jeff (Inventor); Snell, Edward Holmes (Inventor); Bellamy, Henry (Inventor)

    2008-01-01

    The present invention provides a digital topography imaging system for determining the crystalline structure of a biological macromolecule, wherein the system employs a charge coupled device (CCD) camera with antiblooming circuitry to directly convert x-ray signals to electrical signals without the use of phosphor and measures reflection profiles from the x-ray emitting source after x-rays are passed through a sample. Methods for using said system are also provided.

  10. New opportunities with VUV and soft-X-ray free electron lasers: Biological systems

    Science.gov (United States)

    Austin, Robert; Krishana, Kapeeleshwar

    2007-11-01

    Biology is deeply influenced by the structure of biomolecules, the dynamics of biomolecules, the way that biomolecules interact with each other, and how the cellular architecture is influenced by the structure and dynamics of the molecular components. At its most fundamental level, the length scale of these structures and dynamics of primary biological components is on the 1-100 nm length scale. Although there are ingenious optical techniques that reach into that length domain, they involve highly specific and robust optical probes and averaging techniques to find the standard deviation of the mean, greatly limiting our ability to observe the real-time dynamics of cell components at a fundamental level. It is now clear that unraveling the response of cells to ionizing radiation is critical for understanding many fundamental problems in biology, from aging to apoptosis (programmed cell death) to the origins of cancer. Since a cell is spatially highly heterogeneous, simply irradiating cells results in the activation of many different biological pathways. The high brightness of a coherent X-ray/VUV light source would allow irradiating cell components with 100 nm or better spatial resolution, which would be a major step forward in unraveling the response of cells to genomic and component damage.

  11. New opportunities with VUV and soft-X-ray free electron lasers: Biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Austin, Robert [Department of Physics, Princeton University (United States)], E-mail: austin@Princeton.EDU; Krishana, Kapeeleshwar [Malvern Instruments Inc., Southborough, MA 01772 (United States)

    2007-11-11

    Biology is deeply influenced by the structure of biomolecules, the dynamics of biomolecules, the way that biomolecules interact with each other, and how the cellular architecture is influenced by the structure and dynamics of the molecular components. At its most fundamental level, the length scale of these structures and dynamics of primary biological components is on the 1-100 nm length scale. Although there are ingenious optical techniques that reach into that length domain, they involve highly specific and robust optical probes and averaging techniques to find the standard deviation of the mean, greatly limiting our ability to observe the real-time dynamics of cell components at a fundamental level. It is now clear that unraveling the response of cells to ionizing radiation is critical for understanding many fundamental problems in biology, from aging to apoptosis (programmed cell death) to the origins of cancer. Since a cell is spatially highly heterogeneous, simply irradiating cells results in the activation of many different biological pathways. The high brightness of a coherent X-ray/VUV light source would allow irradiating cell components with 100 nm or better spatial resolution, which would be a major step forward in unraveling the response of cells to genomic and component damage.

  12. Distortion of pulse height spectra due to absorbers in the measurement of low-energy beta-rays with a silicon detector

    CERN Document Server

    Yamamoto, H; Norimura, T; Katase, A

    2002-01-01

    In measurement of beta-rays from sup 1 sup 4 C with a silicon semiconductor detector, pulse height spectra are observed to change by insertion of absorbers between the source and the detector. An obvious broad peak appears in the spectra by the insertion. An increase in the absorber thickness reduces the peak height, and shifts the peak position to the higher energy side in the spectra. On the other hand, the increase in the distance between the source and the absorber also reduces the peak height, but does not move the position of the peak. The absorption curve derived from these results shows its particular shape corresponding to the respective position of the absorber. Therefore, the distortion of the pulse height spectrum for low-energy beta-rays depends not only on the thickness of the absorber but also on its position between the source and the detector. (author)

  13. Effect of Gamma-Ray Beaming on the Fluxes of Gamma-Ray Pulsars

    Institute of Scientific and Technical Information of China (English)

    JIANG Ze-Jun; ZHANG Li

    2005-01-01

    @@ We study the effect ofγ-ray beaming on γ-ray emission of the pulsars in a self-sustained outer gap model. In this model, averaged γ-ray flux is a function of period, magnetic field, magnetic inclination angle and solid angle of γ-ray beaming for a γ-ray pulsar. We generate a sample of γ-ray pulsars with their ages less than 106 years by using the Monte Carlo method, and then study the γ-ray beaming effect. The comparison of distributions of periods, magnetic fields, distances, γ-ray energy fluxes and period derivatives of the simulated γ-ray pulsars with those of observed γ-ray pulsars by the detector EGRET shows that γ-ray beaming has an important role on the detection ofγ-ray pulsars. Furthermore, possible γ-ray pulsars observed by the detector GLAST are predicted.PACS: 97. 60. Gb, 95. 85. Pw, 97. 10. Yp

  14. X-ray Absorption Spectroscopy and Coherent X-ray Diffraction Imaging for Time-Resolved Investigation of the Biological Complexes: Computer Modelling towards the XFEL Experiment

    Science.gov (United States)

    Bugaev, A. L.; Guda, A. A.; Yefanov, O. M.; Lorenz, U.; Soldatov, A. V.; Vartanyants, I. A.

    2016-05-01

    The development of the next generation synchrotron radiation sources - free electron lasers - is approaching to become an effective tool for the time-resolved experiments aimed to solve actual problems in various fields such as chemistry’ biology’ medicine’ etc. In order to demonstrate’ how these experiments may be performed for the real systems to obtain information at the atomic and macromolecular levels’ we have performed a molecular dynamics computer simulation combined with quantum chemistry calculations for the human phosphoglycerate kinase enzyme with Mg containing substrate. The simulated structures were used to calculate coherent X-ray diffraction patterns’ reflecting the conformational state of the enzyme, and Mg K-edge X-ray absorption spectra, which depend on the local structure of the substrate. These two techniques give complementary information making such an approach highly effective for time-resolved investigation of various biological complexes, such as metalloproteins or enzymes with metal-containing substrate, to obtain information about both metal-containing active site or substrate and the atomic structure of each conformation.

  15. Development of single shot soft x-ray contact microscopy system for nano-scale dynamics measurement of living biological specimen

    Science.gov (United States)

    Kishimoto, Maki; Kado, Masataka; Ishino, Masahiko; Tamotsu, Satoshi; Yasuda, Keiko; Shinohara, Kunio

    2012-07-01

    We have been developing a picosecond single shot soft x-ray contact microscopy system for observing the nanometer-scale inner structure of the living biological specimen in a hydrated condition. The microscopy system consists of an intense IR pump laser system for generating laser-induced plasma as a soft x-ray source and x-ray microscope chamber. The pump laser system employs OPCPA (Optical Parametric Chirped Pulse Amplification) technique to obtain a high contrast pump laser pulse, and we can generate water-window x-rays effectively by combining it to an ultra-thin metal target. The x-ray microscope chamber is composed of a vacuum chamber, a focusing lens, a metal film target, an in-vacuum type sample holder. The pump laser pulse is focused on the metal film target with a focusing lens. The soft x-rays from the laser-induced plasma illuminates bio-specimens on the PMMA photo resist set in the in-vacuum sample holder. The photo resist is developed and the x-ray transmission image recorded on the photo resist is read out by AFM. We took x-ray images of hydrated Leydig cells from mouse testicle and demonstrated that the developed x-ray microscopy system has a spatial resolution of about 100 nm.

  16. The Biological Effects of Bilirubin Photoisomers.

    Directory of Open Access Journals (Sweden)

    Jana Jasprova

    Full Text Available Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC, and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it; and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf. Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

  17. Probing Cosmic Distance Duality Relation with Sunyaev-Zeldovich Effect, X-rays Observations and Supernovae Ia

    CERN Document Server

    Holanda, R F L; Ribeiro, M B

    2011-01-01

    Measurements of Sunyaev-Zeldovich effect and X-ray combined with the validity of the distance-duality relation can determine the angular diameter distances from galaxy clusters. This sort of combination enable us to probe the galaxy cluster physics or even to test the validity of the distance-duality relation based on two different approaches. Firstly, the possible galaxy cluster morphologies are constrained by assuming the strict validity of the distance-duality relation in the LCDM framework. Secondly, by adopting a cosmological-model-independent test, we confront directly the angular diameters from galaxy clusters with two Supernovae Ia (SNe Ia) sub-samples (carefully chosen to coincide with cluster positions). In our analysis we consider three galaxy clusters samples whose difference lies in the underlying assumptions used to describe the clusters: (i) isothermal elliptical beta model, (ii) isothermal spherical beta model, and (iii) non-isothermal spherical double beta model. The elliptical beta model pro...

  18. Status of international benchmark experiment for effective delayed neutron fraction ({beta}eff)

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, S.; Sakurai, T.; Mukaiyama, T. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To improve the prediction accuracy of the {beta}eff, the program of the international benchmark experiment (Beta Effect Reactor Experiment for a New International Collaborative Evaluation: BERNICE) was planned. This program composed of two parts; BERNICE-MASURCA and BERNICE-FCA. The former one was carried out in the fast critical facility MASURCA of CEA, FRANCE between 1993 and 1994. The latter one started in the FCA, JAERI in 1995 and still is going. In these benchmark experiments, various experimental techniques have been applied for in-pile measurements of the {beta}eff. The accuracy of the measurements was better than 3%. (author)

  19. Cross-beta spine architecture of fibrils formed by the amyloidogenic segment NFGSVQFV of medin from solid-state NMR and X-ray fiber diffraction measurements.

    Science.gov (United States)

    Madine, Jillian; Copland, Alastair; Serpell, Louise C; Middleton, David A

    2009-04-14

    Over 30 polypeptides are known to assemble into highly ordered fibrils associated with pathological disorders known collectively as amyloidoses. Structural studies of short model peptides are beginning to reveal trends in the types of molecular interactions that drive aggregation and stabilize the packing of beta-sheet layers within fibrillar assemblies. This work investigates the molecular architecture of fibrils formed by the peptide AMed42-49 representing residues 42-49 of the 50 amino acid polypeptide medin associated with aortic medial amyloid, the most common form of senile localized amyloid. The peptide aggregates within 2 days to form bundles of microcrystalline-like needles displaying a high degree of order. Fibrils were prepared from peptides containing up to 23 13C labels, and the solid-state nuclear magnetic resonance (SSNMR) method rotational resonance (RR) was used to determine constraints on the distances between selective atomic sites within fibrils. The constraints are consistent with unbroken beta-strands hydrogen bonded in a parallel in-register arrangement within beta-sheets. Further RR measurements identify close (>6.5 A) contacts between residues F43 and V46 and between S45 and V46, which can only occur between beta-sheet layers and which are consistent with two principal models of beta-sheet arrangements. X-ray fiber diffraction from partially aligned fibrils revealed the classical amyloid diffraction pattern, and comparison of patterns calculated from model coordinates with experimental data allowed determination of a consistent molecular model.

  20. Crystal architecture and conformational properties of the inclusion complex, neohesperidin dihydrochalcone-cyclomaltoheptaose (beta-cyclodextrin), by X-ray diffraction.

    Science.gov (United States)

    Malpezzi, Luciana; Fronza, Giovanni; Fuganti, Claudio; Mele, Andrea; Brückner, Sergio

    2004-08-23

    The crystal structure of the host-guest noncovalent complex of cyclomaltoheptaose (beta-cyclodextrin, betaCD) with the O-diglycosyl flavonoid neohesperidin dihydrochalcone [(3,5-dihydroxy-4-(3-hydroxy-4-methoxyhydrocinnamoyl)phenyl-2-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside, NDC] has been determined from single-crystal X-ray diffraction data collected at low temperature (130 K), using synchrotron radiation. The crystal data are as follows: a =15.125(5), b =30.523(5), c =41.332(5) Angstroms, orthorhombic, space group C222(1). The structure contains 19 molecules of water, of which 11 appeared well positioned, whereas 9 are disordered over 23-positions. The betaCD-NDC complex is characterized by one aromatic part of NDC deeply inserted into the hydrophobic cavity of the betaCD through the primary OH rim, and it is present in the crystal as a dimer. The dimeric units, formed by head-to-head assemblies of CD molecules, each with its guest, are self-assembled in columns. The stability of the columns is provided by host-guest and guest-guest attractive interactions, thus showing a key role of the guest molecules in the crystal architecture. The guest conformation in the complex is different from that reported in the literature for uncomplexed NDC. The host-induced conformational changes on NDC provide the optimum geometry requirements for the assembly of the dimeric units.

  1. The satellites and hypersatellites of L{alpha}{sub 12} and L{beta}{sub 1} x-ray transitions in zirconium excited by oxygen and neon ions

    Energy Technology Data Exchange (ETDEWEB)

    Czarnota, M; Pajek, M; Banas, D [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Dousse, J-Cl; Berset, M; Mauron, O; Maillard, Y-P; Raboud, P A; Hoszowska, J [Department of Physics, University of Fribourg, CH-1700 Fribourg (Switzerland); Polasik, M; Slabkowska, K [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Chmielewska, D; Rzadkiewicz, J; Sujkowski, Z, E-mail: marcin@ujk.kielce.p [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)

    2009-11-01

    The interpretation of L-shell satellites and hypersatellites for L{alpha}{sub 1,2} (L{sub 3{yields}}M{sub 4,5}) and L{beta}{sub 1} (L{sub 2{yields}}M{sub 4}) x-ray transitions in zirconium multiply ionized by oxygen and neon ions is reported. The x-ray spectra were measured with a high-resolution von Hamos spectrometer and interpreted in terms the relativistic multi-configuration Dirac-Fock (MCDF) calculations. The ionization probabilities of L- and M-shell derived from the data are compared with the predictions of the semiclassical approximation (SCA) calculations.

  2. Method for photo-altering a biological system to improve biological effect

    Science.gov (United States)

    Hill, Richard A.; Doiron, Daniel R.; Crean, David H.

    2000-08-01

    Photodynamic therapy is a new adjunctive therapy for filtration surgery that does not use chemotherapy agents or radiation, but uses pharmacologically-active sensitizing compounds to produce a titratable, localized, transient, post operative avascular conjunctiva. A photosensitizing agent in a biological system is selectively activated by delivering the photosensitive agent to the biological system and laser activating only a spatially selected portion of the delivered photosensitive agent. The activated portion of the photosensitive agent reacts with the biological system to obtain a predetermined biological effect. As a result, an improved spatial disposition and effectuation of the biological effect by the photosensitive agent in the biological system is achieved.

  3. Effects of transforming growth factor-beta on long-term human cord blood monocyte cultures

    Energy Technology Data Exchange (ETDEWEB)

    Orcel, P.; Bielakoff, J.; De Vernejoul, M.C. (INSERM U18, Hopital Lariboisiere, Paris (France))

    1990-02-01

    Transforming growth factor-beta (TGF-beta) modulates growth and differentiation in many cell types and is abundant in bone matrix. We recently showed that human cord blood monocytes cultured in the presence of 1,25(OH)2D3 acquire some features of osteoclast precursors. Since TGF-beta has been shown to influence bone resorption in organ culture, we have studied the effect of TGF-beta (1-1,000 pg/ml) on cord blood monocyte cultures. These cells were cultured on plastic substrate during 3 weeks in the presence of 20% horse serum and 10(-9) M 1,25(OH)2D3. TGF-beta, from a concentration of 10 pg/ml in the culture medium, decreased in a dose dependent manner the formation of multinucleated cells. At a concentration of TGF-beta of 1 ng/ml, the multinucleated cells were reduced to 2.1% +/- 0.3%, compared to 19.3% +/- 1.5% in control cultures. TGF-beta inhibited in a dose-dependent manner the proliferation of cord blood monocytes as assessed by 3H-thymidine incorporation at 7 and 14 days of culture. The fusion index was also decreased by 3 weeks of treatment with TGF-beta. Indomethacin did not reverse the inhibitory effects of TGF-beta. The expression of the osteoclastic phenotype was assessed using two different antibodies: 23C6, a monoclonal antibody directed against the vitronectin receptor, which is highly expressed by osteoclasts but not by adult monocytes, and an antibody to HLA-DR, which is not present on osteoclast. TGF-beta decreased the expression of HLA-DR and increased in a dose-dependent manner the proportion of 23C6-labeled cells; these results suggest that TGF-beta could modulate a differentiation effect to the osteoclastic phenotype. However, when cord blood monocytes were cultured on devitalized rat calvariae prelabeled with 45Ca, TGF-beta did not induce any 45Ca release from bone cultured with monocytes.

  4. Effect of mixing rate on Beta-carotene production and extraction by dunaliella salina in two-phase bioreactors

    NARCIS (Netherlands)

    Hejazi, M.; Andrysiewicz, E.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    beta-Carotene has many applications in the food, cosmetic, and pharmaceutical industries; Dunaliella salina is currently the main source for natural beta-carotene. We have investigated the effect of mixing rate and whether it leads to the facilitated release of beta-carotene from the cells of Dunali

  5. Effects of ORP150 on appearance and function of pancreatic beta cells following acute necrotizing pancreatitis.

    Science.gov (United States)

    Deng, Wen-Hong; Chen, Chen; Wang, Wei-Xing; Yu, Jia; Li, Jin-You; Liu, Lei

    2011-06-15

    Pancreatic beta cells produce and release insulin, which decreases the blood glucose level. Endoplasmic reticulum stress caused pancreatic beta cell dysfunction and death in acute necrotizing pancreatitis (ANP). The 150kD oxygen-regulated protein (ORP150) took part in the process of endoplasmic reticulum stress. This study investigated the effect of ORP150 on appearance and function of pancreatic beta cells in ANP. Acute necrotizing pancreatitis relied on retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. The severity of ANP was estimated by serum amylase, secretory phospholipase A(2,) and pancreatic histopathology. The changes in appearance and function of pancreatic beta cells were detected by light and electron microscopy and the levels of serum glucose, insulin, and C-peptide. ORP150 expression was studied using western blot and immunohistochemisty assay. The expression of ORP150 mainly appeared on pancreatic beta cells and decreased gradually during the pathogenesis of ANP. The results of light and electron microscopy indicated pancreatic beta cell dysfunction and death, concomitant with elevation of serum glucose, insulin, and C-peptide in ANP. These results imply a probable role of ORP150 in the changes in appearance and function of pancreatic beta cells following acute necrotizing pancreatitis, through the pathway of endoplasmic reticulum stress.

  6. Pancreatic Beta Cell G-Protein Coupled Receptors and Second Messenger Interactions: A Systems Biology Computational Analysis.

    Science.gov (United States)

    Fridlyand, Leonid E; Philipson, Louis H

    2016-01-01

    Insulin secretory in pancreatic beta-cells responses to nutrient stimuli and hormonal modulators include multiple messengers and signaling pathways with complex interdependencies. Here we present a computational model that incorporates recent data on glucose metabolism, plasma membrane potential, G-protein-coupled-receptors (GPCR), cytoplasmic and endoplasmic reticulum calcium dynamics, cAMP and phospholipase C pathways that regulate interactions between second messengers in pancreatic beta-cells. The values of key model parameters were inferred from published experimental data. The model gives a reasonable fit to important aspects of experimentally measured metabolic and second messenger concentrations and provides a framework for analyzing the role of metabolic, hormones and neurotransmitters changes on insulin secretion. Our analysis of the dynamic data provides support for the hypothesis that activation of Ca2+-dependent adenylyl cyclases play a critical role in modulating the effects of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and catecholamines. The regulatory properties of adenylyl cyclase isoforms determine fluctuations in cytoplasmic cAMP concentration and reveal a synergistic action of glucose, GLP-1 and GIP on insulin secretion. On the other hand, the regulatory properties of phospholipase C isoforms determine the interaction of glucose, acetylcholine and free fatty acids (FFA) (that act through the FFA receptors) on insulin secretion. We found that a combination of GPCR agonists activating different messenger pathways can stimulate insulin secretion more effectively than a combination of GPCR agonists for a single pathway. This analysis also suggests that the activators of GLP-1, GIP and FFA receptors may have a relatively low risk of hypoglycemia in fasting conditions whereas an activator of muscarinic receptors can increase this risk. This computational analysis demonstrates that study of second messenger

  7. Effect of different beta blockers on penile vascular velocities in hypertensive males

    OpenAIRE

    Samer Malak Botros; Ahmed Mohamed Hussein; Ahmed Shawky Elserafy

    2015-01-01

    Background: Beta blockers are very commonly used as antihypertensive medications in young active individuals. This class has been accused of erectile dysfunction in patients taking them. Problems with erectile function can raise a concern in the treatment of hypertension and may influence the choice of treatment regimens and decisions to discontinue drugs. Aim: The aim was to assess the effect of different beta blockers: nebivolol, atenolol, bisoprolol, and carvedilol on the penile arteria...

  8. Environmental effects of inclusion complexation between methylated beta-cyclodextrin and diclofop-methyl.

    Science.gov (United States)

    Cai, Xiyun; Liu, Weiping; Chen, Shengwen

    2005-08-24

    Diclofop-methyl (DM) is a broad-spectrum herbicide but often shows a reduced biological activity against the target grasses due to its poor water solubility and slow translocation within plant tissues. Randomly methylated beta-cyclodextrin (MCD) is an effective inclusion complexation agent and, as a potential formulation additive, may thus improve the behavior of DM. We evaluated the complexing role of MCD by measuring the solubility and soil sorption of DM as a function of MCD concentration, as well as the dissolution rates of DM-MCD complexes. The complex was also extensively characterized by UV, fluorescence, Fourier transform infrared, nuclear magnetic resonance, and differential scanning calorimetry techniques. The apparent solubility of DM linearly increased with MCD concentration, indicating the formation of a 1:1 complex. In contrast, diclofop was not complexed by MCD. The DM-MCD complex appeared to have formed within the hydrophobic cavity of MCD. With the measured stability constant of 4740 L mol(-)(1), the complex was apparently stable, which resulted in DM resistant to hydrolysis, and hence the ratio of DM to the sum of DM and diclofop increased toward unity with increasing MCD concentration. The DM-MCD complex also quickly dissolved to a maximum within 5 min, due presumably to the hydrophilicity of MCD. The sorption of DM by soil was significantly reduced in the presence of MCD. All the results suggest that MCD may effectively improve the availability of DM to pests and for bioremediation.

  9. Spatial resolution of electron probe X-ray microanalysis on sections of organic (biological) material

    Energy Technology Data Exchange (ETDEWEB)

    Krefting, E.-R.; Felsmann, M.; Recker, A.; Feja, B.; Hoehling, H.J.; Reichelt, R. [Institut fuer Medizinische Physik und Biophysik, Westfaelische Wilhelms-Universitaet, Robert-Koch-Str. 31, 48149 Muenster (Germany); Reimer, L. [Physikalisches Institut, Westfaelische Wilhelms-Universitaet, Wilhelm-Klm-Str. 10, 48149 Muenster (Germany)

    1999-05-01

    A locally enhanced element concentration influences the result of an X-ray microanalysis at a neighbouring position. This influence was investigated for the first time systematically in organic (biological) material using sections of epoxy resin (thickness 0.5-2.5 {mu}m) containing a layer of pure gold. Wavelength and energy dispersive spectrometers were applied to analyse the X-rays generated by 15-35 keV electrons. Characteristic X-rays could be detected up to distances of several {mu}m from the gold layer. For example, for a 2.4 {mu}m thick section and 35 keV electrons the measured apparent gold concentration was above 0.1% (weight% per dry mass) at a distance of 10 {mu}m. Thus, the lateral resolution may be not better than a multiple of the section thickness. The apparent gold concentration at a given distance is proportional to the specimen thickness and increases with increasing electron energy. Monte Carlo simulations confirm the experimental results. The influence of a local enrichment depends on the particular specimen properties (e.g. thickness, density, mean atomic number), the electron energy, and the geometry of the detector with respect to the specimen. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Structural biology at the European X-ray free-electron laser facility.

    Science.gov (United States)

    Altarelli, Massimo; Mancuso, Adrian P

    2014-07-17

    The European X-ray free-electron laser (XFEL) facility, under construction in the Hamburg region, will provide high-peak brilliance (greater than 10(33) photons s(-1) mm(-2) mrad(-2) per 0.1% BW), ultrashort pulses (approx. 10 fs) of X-rays, with a high repetition rate (up to 27 000 pulses s(-1)) from 2016 onwards. The main features of this exceptional X-ray source, and the instrumentation developments necessary to exploit them fully, for application to a variety of scientific disciplines, are briefly summarized. In the case of structural biology, that has a central role in the scientific case of this new facility, the instruments and ancillary laboratories that are being planned and built within the baseline programme of the European XFEL and by consortia of users are also discussed. It is expected that the unique features of the source and the advanced features of the instrumentation will allow operation modes with more efficient use of sample materials, faster acquisition times, and conditions better approaching feasibility of single molecule imaging.

  11. Study of the irradiation effects on thorium phosphate diphosphate ({beta}-TPD): consequences on its chemical durability; Etude des effets d'irradiation sur le phosphate diphosphate de thorium ({beta}-PDT): consequences sur la durabilite chimique

    Energy Technology Data Exchange (ETDEWEB)

    Tamain, C

    2005-12-15

    Since Thorium Phosphate Diphosphate (beta-TPD) can be considered as a potential host matrix for long-term storage in underground repository, it is necessary to study the irradiation effects on the structure of this ceramics and the consequences on its chemical durability. Sintered samples of beta-TPD and of associated solid solutions of beta-TUPD were irradiated under ion beams and then altered in aqueous solutions. Depending on the electronic LET value, beta-TPD can be completely or partly amorphized. Furthermore, the ability of recrystallization of the amorphous material by thermal annealing was also demonstrated. Some leaching tests, realized on these irradiated samples, have shown a significant effect of the amorphous fraction on the normalized dissolution rate which was increased by a factor of 10 from the crystallized to the fully amorphized material. Correlatively, the amorphous fraction also modified the delay to reach the saturation conditions associated to the thermodynamic equilibria involved. On the other hand, it exhibited no influence neither on other kinetic parameters, such as activation energy of the dissolution process or partial order related to the proton concentration, nor on the nature of the neo-formed phase formed at the saturation of the leachate and identified as Thorium Phosphate Hydrogeno-Phosphate Hydrate (TPHPH). Beta-TUPD samples were also irradiated by gamma and alpha rays during leaching tests to study the effects of radiolysis in the leaching medium on the normalized leaching rate. It appeared that the radiolytic species occurring in the dissolution mechanism were unstable, disappearing quickly when stopping the irradiation. (author)

  12. Pressure effect on paramagnet {beta}-US{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)], E-mail: ikeda.shugo@jaea.go.jp; Sakai, H.; Matsuda, T.D.; Tateiwa, N.; Nakamura, A.; Yamamoto, E. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Aoki, D.; Homma, Y.; Shiokawa, Y. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Hedo, M.; Uwatoko, Y.; Haga, Y. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Ounki, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2008-04-01

    Single crystals of paramagnetic semiconductor {beta}-US{sub 2} with the orthorhombic (Pnma) crystal structure were grown by chemical transport method. We measured the electrical resistivity {rho} under high pressure, and magnetization. With increasing pressure, the temperature dependence of {rho} approaches to semimetallic behavior and a kink anomaly appears at T{sub a}. T{sub a} shifts to higher temperature with increasing pressure. From the comparison with ferromagnetic semimetal UTeS having the same crystal structure, it seems that T{sub a} is a ferromagnetic transition.

  13. Expression and characterization of recombinant single-chain salmon class I MHC fused with beta2-microglobulin with biological activity

    DEFF Research Database (Denmark)

    Zhao, Heng; Stet, René J M; Skjødt, Karsten;

    2008-01-01

    Heterodimeric class I major histocompatibility complex (MHC) molecules consist of a putative 45-kDa heavy chain and a 12-kDa beta2-microglobulin (beta2m) light chain. The knowledge about MHC genes in Atlantic salmon accumulated during the last decade has allowed us to generate soluble and stable ...

  14. Purification and biochemical characterization of the complete structure of a proteolytically modified beta-2-microglobulin with biological activity

    DEFF Research Database (Denmark)

    Nissen, Mogens Holst; Thim, L; Christensen, M

    1987-01-01

    A modified form of beta-2-microglobulin (beta-2-m) has previously been described to be present in serum from patients suffering from autoimmune diseases, acquired immune deficiency syndrome and small-cell lung cancer [Plesner, T. and Wiik, A. (1979) Scand. J. Immunol. 9, 247-254; Bhalla et al. (1...

  15. Three-Dimensional X-ray Observation of Atmospheric Biological Samples by Linear-Array Scanning-Electron Generation X-ray Microscope System

    Science.gov (United States)

    Ogura, Toshihiko

    2011-01-01

    Recently, we developed a soft X-ray microscope called the scanning-electron generation X-ray microscope (SGXM), which consists of a simple X-ray detection system that detects X-rays emitted from the interaction between a scanning electron beam (EB) and the thin film of the sample mount. We present herein a three-dimensional (3D) X-ray detection system that is based on the SGXM technology and designed for studying atmospheric biological samples. This 3D X-ray detection system contains a linear X-ray photodiode (PD) array. The specimens are placed under a CuZn-coated Si3N4 thin film, which is attached to an atmospheric sample holder. Multiple tilt X-ray images of the samples are detected simultaneously by the linear array of X-ray PDs, and the 3D structure is calculated by a new 3D reconstruction method that uses a simulated-annealing algorithm. The resulting 3D models clearly reveal the inner structure of the bacterium. In addition, the proposed method can easily be used for diverse samples in a broad range of scientific fields. PMID:21731770

  16. Three-dimensional X-ray observation of atmospheric biological samples by linear-array scanning-electron generation X-ray microscope system.

    Science.gov (United States)

    Ogura, Toshihiko

    2011-01-01

    Recently, we developed a soft X-ray microscope called the scanning-electron generation X-ray microscope (SGXM), which consists of a simple X-ray detection system that detects X-rays emitted from the interaction between a scanning electron beam (EB) and the thin film of the sample mount. We present herein a three-dimensional (3D) X-ray detection system that is based on the SGXM technology and designed for studying atmospheric biological samples. This 3D X-ray detection system contains a linear X-ray photodiode (PD) array. The specimens are placed under a CuZn-coated Si₃N₄ thin film, which is attached to an atmospheric sample holder. Multiple tilt X-ray images of the samples are detected simultaneously by the linear array of X-ray PDs, and the 3D structure is calculated by a new 3D reconstruction method that uses a simulated-annealing algorithm. The resulting 3D models clearly reveal the inner structure of the bacterium. In addition, the proposed method can easily be used for diverse samples in a broad range of scientific fields.

  17. Three-dimensional X-ray observation of atmospheric biological samples by linear-array scanning-electron generation X-ray microscope system.

    Directory of Open Access Journals (Sweden)

    Toshihiko Ogura

    Full Text Available Recently, we developed a soft X-ray microscope called the scanning-electron generation X-ray microscope (SGXM, which consists of a simple X-ray detection system that detects X-rays emitted from the interaction between a scanning electron beam (EB and the thin film of the sample mount. We present herein a three-dimensional (3D X-ray detection system that is based on the SGXM technology and designed for studying atmospheric biological samples. This 3D X-ray detection system contains a linear X-ray photodiode (PD array. The specimens are placed under a CuZn-coated Si₃N₄ thin film, which is attached to an atmospheric sample holder. Multiple tilt X-ray images of the samples are detected simultaneously by the linear array of X-ray PDs, and the 3D structure is calculated by a new 3D reconstruction method that uses a simulated-annealing algorithm. The resulting 3D models clearly reveal the inner structure of the bacterium. In addition, the proposed method can easily be used for diverse samples in a broad range of scientific fields.

  18. The effects of glucagon-like peptide-1 on the beta cell

    DEFF Research Database (Denmark)

    Vilsbøll, Tina

    2009-01-01

    Type 2 diabetes is a progressive disease characterized by insulin resistance and impaired beta-cell function. Treatments that prevent further beta-cell decline are therefore essential for the management of type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is known...... to stimulate glucose-dependent insulin secretion. Furthermore, GLP-1 appears to have multiple positive effects on beta cells. However, GLP-1 is rapidly degraded by dipeptidyl peptidase-4 (DPP-4), which limits the clinical relevance of GLP-1 for the treatment of type 2 diabetes. Two main classes of GLP-1-based...... therapies have now been developed: DPP-4 inhibitors and GLP-1 receptor agonists. Liraglutide and exenatide are examples of GLP-1 receptor agonists that have been developed to mimic the insulinotropic characteristics of endogenous GLP-1. Both have demonstrated improved beta-cell function in patients...

  19. Effects of chronic delta-9-THC treatment on cardiac beta-adrenoceptors in rats

    Energy Technology Data Exchange (ETDEWEB)

    Evans, E.B.; Seifen, E.; Kennedy, R.H.; Kafiluddi, R.; Paule, M.G.; Scallet, A.C.; Ali, S.F.; Slikker, W. Jr.

    1987-10-01

    This study was designed to determine if chronic treatment with delta-9-tetrahydrocannabinol (THC) alters cardiac beta-adrenoceptors in the rat. Following daily oral administration of 10 or 20 mg/kg THC or an equivalent volume of control solvent for 90 days, rats were sacrificed, and sarcolemmal membranes were prepared from ventricular myocardium. Beta-adrenoceptor density and binding affinity estimated with (-)(/sup 3/H)dihydroalprenolol; a beta-adrenergic antagonist, were not significantly affected by treatment with THC when compared to vehicle controls. These results suggest that the tolerance to cardiovascular effects of THC which develops during chronic exposure in the rat is not associated with alterations in cardiac beta-adrenoceptors as monitored by radiolabeled antagonist binding.

  20. Effect of beta-cyclodextrin on aroma release and flavor perception.

    Science.gov (United States)

    Kant, Avinash; Linforth, Robert S T; Hort, Joanne; Taylor, Andrew J

    2004-04-07

    Binding and release of volatile compounds to and from beta-cyclodextrin were measured in model aqueous systems using static equilibrium headspace and dynamic headspace dilution. Beta-cyclodextrin decreased the static equilibrium headspace for some volatiles (e.g., ethyl octanoate and decanone) due to binding, but dilution studies demonstrated that binding was readily reversible. Dynamic release of hydrophobic volatile compounds was similar to that observed from emulsions. When beta-cyclodextrin was added to fat free yogurt, the release of a commercial lemon flavoring was modified and was similar to release from a regular fat yogurt. Sensory difference testing confirmed the release results. The data demonstrate that beta-cyclodextrin can be used to modify flavor delivery in both model and real systems; the effects in the latter are sensorially significant.

  1. Effects of transforming growth factor beta, tumor necrosis factor alpha, interferon gamma and LIF-HILDA on the proliferation of acute myeloid leukemia cells.

    Science.gov (United States)

    Kerangueven, F; Sempere, C; Tabilio, A; Mannoni, P

    1990-01-01

    A group of polypeptide factors that regulate cell growth and differentiation has been tested for their biological activities on the growth and differentiation of leukemic cells isolated from patients with Acute Myeloid Leukemias (AML). The effects of Transforming Growth Factor beta 1 (TGF beta), Tumor Necrosis Factor alpha (TNF alpha), Interferon gamma (IFN gamma) and LIF-HILDA were compared on leukemic cells cultured in vitro for seven days. Spontaneously growing leukemic cells were selected in order to study either inhibition or enhancement of proliferation induced by these factors. Only TGF beta 1 was found to induce a clear inhibition of leukemic proliferation in all cases tested. Recombinant TNF alpha and IFN gamma were found to induce either inhibition or enhancement of the proliferation on separate specimens. Under the conditions of culture, it was not possible to document any effect of LIF-HILDA. Cell differentiation and cell maturation were documented studying the modulation of cell surface antigens. TGF beta did not modify antigen expression on the cells surviving after 3 days in culture. Both TNF alpha and IFN gamma were found to enhance the expression of adhesion molecules and to a lesser extent, the expression of some lineage associated antigens. No effect of LIF-HILDA on antigen modulation was documented in the cases tested. These data confirm that TGF beta is by itself a potent inhibitor of the myeloid leukemia cells proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Interferons beta have vasoconstrictive and procoagulant effects: a woman who developed livedo reticularis and Raynaud phenomenon in association with interferon beta treatment for multiple sclerosis.

    Science.gov (United States)

    Rot, Uroš; Ledinek, Alenka Horvat

    2013-12-01

    A 31-year-old woman with MS developed livedo reticularis and secondary Raynaud phenomenon 2.5 years after introduction of interferon beta-1b. The symptoms disappeared after withdrawal of the drug. Livedo reticularis and Raynaud phenomenon as well as pulmonary arterial hypertension, venous sinus thrombosis, pulmonary embolism and renal thrombotic microangiopathy have all been described in association with interferon beta therapy. These complications strongly suggest that type I interferons have vasoconstrictive and procoagulant effects with potentially serious systemic complications.

  3. Alpha and beta adrenergic effects on metabolism in contracting, perfused muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Galbo, H

    1982-01-01

    The role of alpha- and beta-adrenergic receptor stimulation for the effect of epinephrine on muscle glycogenolysis, glucose- and oxygen uptake and muscle performance was studied in the perfused rat hindquarter at rest and during electrical stimulation (60 contractions/min). Adrenergic stimulation...... was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect...... of alpha-adrenergic receptors and had a positive inotropic effect during contractions which was abolished by alpha- as well as by beta-adrenergic blockade. The results indicate that epinephrine has profound effects on contracting muscle, and that these effects are elicited through different combinations...

  4. BIOLOGICAL EFFECTS ON THE SOURCE OF GEONEUTRINOS

    DEFF Research Database (Denmark)

    Sleep, Norman H.; Bird, Dennis K.; Rosing, Minik T.

    2013-01-01

    Detection of antineutrinos from U and Th series decay within the Earth (geoneutrinos) constrains the absolute abundance of these elements. Marine detectors will measure the ratio over the mantle beneath the site and provide spatial averaging. The measured mantle Th/U may well be significantly below...... its bulk earth value of similar to 4; Pb isotope measurements on mantle-derived rocks yield low Th/U values, effectively averaged over geological time. The physics of the modern biological process is complicated, but the net effect is that much of the U in the mantle comes from subducted marine......, these elements behave similarly in the absence of life, where the elements occur as U(IV) and Th(IV), which do not significantly fractionate during igneous processes. Neither do they fractionate during weathering, as they are essentially insoluble in water in surface environments. Th(IV) and U(IV) remain...

  5. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, Amanda K. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Raha, Sandeep [Department of Pediatrics, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Holloway, Alison C., E-mail: hollow@mcmaster.ca [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada)

    2012-11-15

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  6. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    Energy Technology Data Exchange (ETDEWEB)

    Anzai, Jun, E-mail: anzai_jun@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nozaki, Takenori, E-mail: tnozaki@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Toshie, E-mail: nagayasu_toshie@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Terashima, Akio, E-mail: terashima_akio@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Asano, Taiji, E-mail: asano_taiji@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Murakami, Shinya, E-mail: ipshinya@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  7. Finite beta and compressibility effects on stability of resistive modes in toroidal geometry

    Energy Technology Data Exchange (ETDEWEB)

    Leboeuf, J.-N.G. [Oak Ridge National Lab., TN (United States); Kurita, Gen-ichi

    1998-03-01

    Linear resistive stability results obtained from the toroidal magnetohydrodynamic codes FAR developed at the Oak Ridge National Laboratory in United States of America and AEOLUS developed at the Japan Atomic Energy Research Institute are compared for carefully constructed benchmark profiles and parameters. These are unstable to a tearing mode with toroidal mode number n=1. The eigenvalues and eigenfunctions calculated with both codes are in close agreement and show that the effect of compressibility is weak for these modes. The effect of finite plasma beta is considered, and the eigenvalues calculated by the FAR and AEOLUS codes also show good agreement. It is shown that the finite beta has a stabilizing effect on the toroidal tearing mode, but that the compressibility also has little effect on finite beta tearing modes. (author)

  8. Effect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers.

    Science.gov (United States)

    Chung, Weiliang; Shaw, Greg; Anderson, Megan E; Pyne, David B; Saunders, Philo U; Bishop, David J; Burke, Louise M

    2012-10-09

    Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD) were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter) or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships) and after (international or national selection meet) supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ± 0.8%, mean, ± 90% confidence limits) of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (-1.3%; ± 1.0%), there was an unclear effect at ten weeks (-0.2%; ± 1.5%) and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  9. Effect of 10 Week Beta-Alanine Supplementation on Competition and Training Performance in Elite Swimmers

    Directory of Open Access Journals (Sweden)

    Louise M. Burke

    2012-10-01

    Full Text Available Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships and after (international or national selection meet supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ±0.8%, mean, ±90% confidence limits of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (−1.3%; ±1.0%, there was an unclear effect at ten weeks (−0.2%; ±1.5% and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  10. Effects of beta blockade on sudden cardiac death during acute myocardial infarction and the postinfarction period.

    Science.gov (United States)

    Hjalmarson, A

    1997-11-13

    About half of all deaths after myocardial infarction (MI) are sudden cardiac deaths. Most of these are thought to be due to ventricular fibrillation (VF). A number of interventions and many different antiarrhythmic agents have been investigated, but so far only beta-blocker therapy has been found to produce significant reductions in the risk of sudden cardiac death after MI. Reductions in total mortality and sudden cardiac death were first reported in 1981 in 3 placebo-controlled studies, the Norwegian Timolol Study, the American Beta-Blocker Heart Attack Trial (BHAT), and the Göteborg Metoprolol Trial. A few years later, two very large trials, the Metoprolol in Acute Myocardial Infarction (MIAMI) study and the First International Study of Infarct Survival (ISIS-1), which included 6,000 and 16,000 patients, respectively, showed that beta-blocker therapy could reduce mortality within the first 2 weeks after onset of MI. Data from 24 postinfarction studies with long-term follow-up show an average 20% mortality reduction over 2 years. Pooled results of 28 short-term, randomized, placebo-controlled trials in which beta blockers were given intravenously shortly after onset of MI indicate an average 13% mortality reduction within 2 weeks. In the 16 studies in which the sudden cardiac death rate was reported, the beneficial effect of beta blockade was even more marked: a 34% average reduction of risk. Not all studies with beta blockers, however, have demonstrated a significant reduction in the incidence of sudden cardiac death. Such an effect has been clearly demonstrated only for the more lipophilic beta blockers (timolol, metoprolol, and propranolol). Two of these lipophilic beta blockers, metoprolol and propranolol, have also been shown to prevent VF after MI in clinical studies. Based on observations from animal experiments, it has been proposed that beta blockers with a high degree of lipophilicity penetrate the brain and thereby maintain high vagal tone during

  11. Cosmic ray effects in microcalorimeter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Stahle, C.K. E-mail: cak@lheapop.gsfc.nasa.gov; Boyce, K.R.; Brown, G.V.; Cottam, J.; Figueroa-Feliciano, E.; Galeazzi, M.; Kelley, R.L.; McCammon, D.; Porter, F.S.; Szymkowiak, A.E.; Tillotson, W.A

    2004-03-11

    We have identified signals resulting from cosmic rays and environmental gamma rays depositing energy in the pixels and in the silicon frame of the Astro-E2/X-Ray Spectrometer microcalorimeter array. Coincidences between pixels and between the array and an anti-coincidence detector determined the nature of the events. Pulse shapes and amplitudes from the cosmic ray events helped refine the thermal model of the array chip. We discuss how future arrays can be optimized either for the greatest background rejection or for the highest source count rates.

  12. The effects of pomegranate seed extract and beta-sitosterol on rat uterine contractions.

    Science.gov (United States)

    Promprom, Wilawan; Kupittayanant, Pakanit; Indrapichate, Korakod; Wray, Susan; Kupittayanant, Sajeera

    2010-03-01

    The aim of this study was to investigate the effects of pomegranate (Punica granatum L., Punicaceae) seed extract on uterine contractility. Pomegranate seeds were methanolic extracted and their constituents analyzed using gas chromatography and mass spectrometry. Isometric force was measured in strips of longitudinal rat myometrium and the effects of pomegranate seed extract studied. We found beta-sitosterol to be the main constituent of the extract (16%) and its effects were also investigated. Pomegranate seed extract and beta-sitosterol increased spontaneous contractions in a concentration-dependent manner with a maximum effect at 250 mg/100 mL and 1 mg/100 mL, respectively. The amplitude and frequency of the phasic contraction were significantly increased along with basal tension. The effects of pomegranate seed extract were very similar to those of beta-sitosterol. Force produced in the presence of pomegranate seed extract was abolished by the inhibition of L-type calcium channels or myosin light chain kinase (MLCK). Contractions were not potentiated by pomegranate extract following the inhibition of K channels or inhibition of the sarcoplasmic reticulum calcium ATPase (SERCA). The actions of beta-sitosterol and the extract were not blocked by the estrogen receptor blocker, fulvestrant. We conclude that pomegranate seed extract is a potent stimulator of phasic activity in rat uterus. Our data suggest that the uterotonic effect is due to nonestrogenic effects of beta-sitosterol acting to inhibit K channels and SERCA and thereby increasing contraction via calcium entry on L-type calcium channels and MLCK. We suggest that pomegranate extract and beta-sitosterol may be a useful uterine stimulant.

  13. Synchrotron-based X-ray fluorescence, imaging and elemental mapping from biological samples

    Indian Academy of Sciences (India)

    D V Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G E Gigante

    2011-02-01

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of ∼ 10 m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a `step-and-repeat’ mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  14. Synchrotron-based X-ray fluorescence imaging and elemental mapping from biological samples

    Energy Technology Data Exchange (ETDEWEB)

    D Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G Gigante

    2011-12-31

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of {approx}10 {mu}m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  15. Biological effects of space radiation and development of effective countermeasures

    Science.gov (United States)

    Kennedy, Ann R.

    2014-04-01

    As part of a program to assess the adverse biological effects expected from astronauts' exposure to space radiation, numerous different biological effects relating to astronauts' health have been evaluated. There has been major focus recently on the assessment of risks related to exposure to solar particle event (SPE) radiation. The effects related to various types of space radiation exposure that have been evaluated are: gene expression changes (primarily associated with programmed cell death and extracellular matrix (ECM) remodeling), oxidative stress, gastrointestinal tract bacterial translocation and immune system activation, peripheral hematopoietic cell counts, emesis, blood coagulation, skin, behavior/fatigue (including social exploration, submaximal exercise treadmill and spontaneous locomotor activity), heart functions, alterations in biological endpoints related to astronauts' vision problems (lumbar puncture/intracranial pressure, ocular ultrasound and histopathology studies), and survival, as well as long-term effects such as cancer and cataract development. A number of different countermeasures have been identified that can potentially mitigate or prevent the adverse biological effects resulting from exposure to space radiation.

  16. Enoxaparin treatment administered at both early and late stages of amyloid beta deposition improves cognition of APPswe/PS1dE9 mice with differential effects on brain A beta levels.

    NARCIS (Netherlands)

    Timmer, N.M.; Dijk, L. van; Zee, C.E.E.M. van der; Kiliaan, A.J.; Waal, R.M.W. de; Verbeek, M.M.

    2010-01-01

    Enoxaparin (Enox), a low molecular weight heparin, has been shown to lower brain amyloid beta (A beta) load in a mouse model for Alzheimer's disease. However, the effect of Enox on cognition was not studied. Therefore, we examined the effect of peripheral Enox treatment on cognition and brain A beta

  17. Biological implications of high-energy cosmic ray induced muon flux in the extragalactic shock model

    CERN Document Server

    Atri, Dimitra

    2011-01-01

    A ~ 62 My periodicity in fossil biodiversity has been observed in independent studies of paleobiology databases going back 542 My. The period and phase of this biodiversity cycle coincides with the motion of our solar system in the galactic disk that oscillates perpendicular to the galactic plane with an amplitude of about 70 parsecs and a period of 63.6 My. Our Galaxy is falling toward the Virgo cluster due to its gravitational pull, forming a galactic shock at the north end of our galaxy due to this motion, capable of accelerating particles and exposing our galaxy's northern side to a higher flux of cosmic rays. These high-energy particles strike the Earth's atmosphere initiating extensive air showers, ionizing the atmosphere by producing charged secondary particles. Secondary particles such as muons produced as a result of nuclear interactions are able to reach the ground, enhancing the biological radiation dose, causing DNA damage and increasing mutation rates, which can have serious biological implicatio...

  18. Effect of Oral Beta-Hydroxy-Beta-Methylbutyrate (HMB Supplementation on Physical Performance in Healthy Old Women Over 65 Years: An Open Label Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Linda Berton

    Full Text Available Although older people are particularly liable to sarcopenia, limited research is available on beta-hydroxy-beta-methylbutyrate (HMB supplementation in this population, particularly in healthy subjects. In this parallel-group, randomized, controlled, open-label trial, we aimed to evaluate whether an oral supplement containing 1.5 g of calcium HMB for 8 weeks could improve physical performance and muscle strength parameters in a group of community-dwelling healthy older women. Eighty healthy women attending a twice-weekly mild fitness program were divided into two equal groups of 40, and 32 of the treated women and 33 control completed the study. We considered a change in the Short Physical Performance Battery (SPPB score as the primary outcome and changes in the peak torque (PT isometric and isokinetic strength of the lower limbs, 6-minute walking test (6MWT, handgrip strength and endurance as secondary outcomes. Body composition was assessed with dual-energy X-ray absorptiometry (DXA and peripheral quantitative computerized tomography (pQCT. The mean difference between the two groups on pre-post change were finally calculated (delta for each outcome. After 8 weeks, there were no significant differences between the groups’ SPPB, handgrip strength or DXA parameters. The group treated with HMB scored significantly better than the control group for PT isokinetic flexion (delta = 1.56±1.56 Nm; p = 0.03 and extension (delta = 3.32±2.61 Nm; p = 0.03, PT isometric strength (delta = 9.74±3.90 Nm; p = 0.02, 6MWT (delta = 7.67±8.29 m; p = 0.04, handgrip endurance (delta = 21.41±16.28 s; p = 0.02, and muscle density assessed with pQCT. No serious adverse effects were reported in either group. In conclusion, a nutritional supplement containing 1.5 g of calcium HMB for 8 weeks in healthy elderly women had no significant effects on SPPB, but did significantly improve several muscle strength and physical performance parameters.ClinicalTrials.gov NCT

  19. Effect of. beta. -endorphin on catecholamine levels in rat hypothalamus and cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V.N.; Valueva, G.V.; Markov, V.V.; Luchitskii, E.V.

    1986-10-01

    The authors studied the effect of beta-endorphin on catecholamine concentrations in the hypothalmus and cerebral cortex in rats, as a contribution to the explanation of the mechanism of action of this peptide on certain pituitary trophic functions. Concentrations of dopamine, noradrenalin, and adrenalin were determined by a radioenzymatic method. A Mark 3 scintillation system was used for radiometric investigation of the samples. The results of these experiments indicate that beta-endorphin has a marked effect on brain catecholamine levels mainly in the hypothalamus.

  20. Radon exposure of the skin: I. Biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Charles, M W [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2007-09-15

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range {approx}66 {mu}m) and Po-214 (6 MeV, range {approx}44 {mu}m). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 {mu}m. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the

  1. The modulatory effect of adaptive deep brain stimulation on beta bursts in Parkinson's disease.

    Science.gov (United States)

    Tinkhauser, Gerd; Pogosyan, Alek; Little, Simon; Beudel, Martijn; Herz, Damian M; Tan, Huiling; Brown, Peter

    2017-02-13

    Adaptive deep brain stimulation uses feedback about the state of neural circuits to control stimulation rather than delivering fixed stimulation all the time, as currently performed. In patients with Parkinson's disease, elevations in beta activity (13-35 Hz) in the subthalamic nucleus have been demonstrated to correlate with clinical impairment and have provided the basis for feedback control in trials of adaptive deep brain stimulation. These pilot studies have suggested that adaptive deep brain stimulation may potentially be more effective, efficient and selective than conventional deep brain stimulation, implying mechanistic differences between the two approaches. Here we test the hypothesis that such differences arise through differential effects on the temporal dynamics of beta activity. The latter is not constantly increased in Parkinson's disease, but comes in bursts of different durations and amplitudes. We demonstrate that the amplitude of beta activity in the subthalamic nucleus increases in proportion to burst duration, consistent with progressively increasing synchronization. Effective adaptive deep brain stimulation truncated long beta bursts shifting the distribution of burst duration away from long duration with large amplitude towards short duration, lower amplitude bursts. Critically, bursts with shorter duration are negatively and bursts with longer duration positively correlated with the motor impairment off stimulation. Conventional deep brain stimulation did not change the distribution of burst durations. Although both adaptive and conventional deep brain stimulation suppressed mean beta activity amplitude compared to the unstimulated state, this was achieved by a selective effect on burst duration during adaptive deep brain stimulation, whereas conventional deep brain stimulation globally suppressed beta activity. We posit that the relatively selective effect of adaptive deep brain stimulation provides a rationale for why this approach could

  2. Bioassay for neutron-dose estimations of three patients in the JCO criticality accident in Tokai-mura by measuring beta-ray emitters.

    Science.gov (United States)

    Takeda, H; Miyamoto, K; Yukawa, M; Nishimura, Y; Watanabe, Y; Kim, H S; Fuma, S; Kuroda, N; Kouno, F; Joshima, H; Hirama, T; Akashi, M

    2001-09-01

    The measurement of beta-emitters in biological samples (hair, urine and bone) from three patients in the JCO criticality accident was performed to assess the neutron dose to individuals. The result of the measurements of 32P in hair and urine collected immediately after the accident showed that sufficient 32P activities had been induced in the hair by fast neutrons and in the urine by thermal neutrons to know the severity of the exposure to the individuals and to the position. From the measurement of 32P and 45Ca in bone from various anatomical parts of two patients who died 82 and 210 days after the accident, it was suggested that the distribution of the induced beta-emitters activities could prove the position and posture of the patients at the moment of exposure.

  3. Effect of Nɛ-carboxymethyllysine on oxidative stress and the glutathione system in beta cells

    Directory of Open Access Journals (Sweden)

    Daniëlle M.P.H.J. Boesten

    2014-01-01

    Full Text Available One of the pathways involved in the pathogenesis of diabetic complications is the formation of excessive levels of advanced glycation end (AGE products. Nɛ-carboxymethyllysine (CML is one of the best-characterized AGEs. Because little is known about the effects of AGEs on pancreatic beta cells, we investigated the effect of CML on human pancreatic cells and determined the activity and gene expression of glutathione system components. CML at a concentration of 0.5 mM induced cell death in human pancreatic beta cells, which was accompanied by increased intracellular oxidative stress. No changes in the gene expression of the receptor for AGEs (RAGE were found, although an increase in the level of a target cytokine of RAGE after CML exposure was observed. Additionally we found that CML lowered the levels of GSH and affected the activity and expression of other components of the glutathione system. These changes indicate that the cells are even more vulnerable for oxidative stress after exposure to CML. Since beta cells are low in antioxidant enzymes and repair for oxidized DNA, CML, but most likely also other AGEs, accelerates beta cell dysfunction and increases beta cell death during chronic hyperglycemia.

  4. Effects of thyroid hormone on. beta. -adrenergic responsiveness of aging cardiovascular systems

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, G.; Hashimoto, K.; Hoffman, B.B.

    1987-03-01

    The authors have compared the effects of ..beta..-adrenergic stimulation on the heart and peripheral vasculature of young (2-mo-old) and older (12-mo-old) rats both in the presence and absence of triiodothyronine (T/sub 3/)-induced hyperthyroidism. The hemodynamic consequences of T/sub 3/ treatment were less prominent in the aged hyperthyroid rats compared with young hyperthyroid rats (both in intact and pithed rats). There was a decrease in sensitivity of chronotropic responsiveness to isoproterenol in older pithed rats, which was apparently reversed by T/sub 3/ treatment. The number and affinity of myocardial ..beta..-adrenergic receptor sites measured by (/sup 125/I)cyanopindolol were not significantly different in young and older control rats; also, ..beta..-receptor density increased to a similar extent in both young and older T/sub 3/-treated rats. The ability of isoproterenol to relax mesenteric arterial rings, markedly blunted in older rats, was partially restored by T/sub 3/ treatment without their being any change in isoproterenol-mediated relaxation in the arterial preparation from young rats. The number and affinity of the ..beta..-adrenergic receptors measured in the mesenteric arteries was unaffected by either aging or T/sub 3/ treatment. The data suggest that effects of thyroid hormone and age-related alterations of cardiovascular responsiveness to ..beta..-adrenergic stimulation are interrelated in a complex fashion with a net result that the hyperkinetic cardiovascular manifestations in hyperthyroidism are attenuated in the older animals.

  5. Investigation of the effect of beta source and phosphors on photovoltaic cells

    Science.gov (United States)

    Yürük, Reyyan Kavak; Tütüncüler, Hayriye

    2017-02-01

    In this study, conversion of kinetic energy from the decay of a radioactive isotope to electricity is investigated by using the direct and the indirect conversion methods. In this context, simple nuclear battery models are designed. Analysis for the effect of low-activity radiation from Pm147 and Sr90 beta sources on photovoltaic Si solar cell is presented. Beta radioluminescence nuclear battery models consist of a beta source, a phosphor layer and a solar cell. Phosphor layers with different mass thicknesses are prepared from ZnS:CuCl and SrAl2O4:Eu2+,Dy3+ phosphors. Both the influence of beta sources and the phosphor layers on battery performance is analyzed separately. Effect of beta sources, phosphors are observed on solar cell by measuring the short circuit current and open circuit voltage. The efficiency of the battery models is determined with the obtained results. Furthermore, short circuit current values are analyzed at various times during the irradiation.

  6. Small and Wide Angle X-ray Scattering studies of biological macromolecules in solution.

    Science.gov (United States)

    Liu, Li; Boldon, Lauren; Urquhart, Melissa; Wang, Xiangyu

    2013-01-08

    In this paper, Small and Wide Angle X-ray Scattering (SWAXS) analysis of macromolecules is demonstrated through experimentation. SWAXS is a technique where X-rays are elastically scattered by an inhomogeneous sample in the nm-range at small angles (typically 0.1 - 5°) and wide angles (typically > 5°). This technique provides information about the shape, size, and distribution of macromolecules, characteristic distances of partially ordered materials, pore sizes, and surface-to-volume ratio. Small Angle X-ray Scattering (SAXS) is capable of delivering structural information of macromolecules between 1 and 200 nm, whereas Wide Angle X-ray Scattering (WAXS) can resolve even smaller Bragg spacing of samples between 0.33 nm and 0.49 nm based on the specific system setup and detector. The spacing is determined from Bragg's law and is dependent on the wavelength and incident angle. In a SWAXS experiment, the materials can be solid or liquid and may contain solid, liquid or gaseous domains (so-called particles) of the same or another material in any combination. SWAXS applications are very broad and include colloids of all types: metals, composites, cement, oil, polymers, plastics, proteins, foods, and pharmaceuticals. For solid samples, the thickness is limited to approximately 5 mm. Usage of a lab-based SWAXS instrument is detailed in this paper. With the available software (e.g., GNOM-ATSAS 2.3 package by D. Svergun EMBL-Hamburg and EasySWAXS software) for the SWAXS system, an experiment can be conducted to determine certain parameters of interest for the given sample. One example of a biological macromolecule experiment is the analysis of 2 wt% lysozyme in a water-based aqueous buffer which can be chosen and prepared through numerous methods. The preparation of the sample follows the guidelines below in the Preparation of the Sample section. Through SWAXS experimentation, important structural parameters of lysozyme, e.g. the radius of gyration, can be analyzed.

  7. The effects of Tai Chi practice on intermuscular beta coherence and the rubber hand illusion

    Directory of Open Access Journals (Sweden)

    Catherine eKerr

    2016-02-01

    Full Text Available Tai Chi (TC is a slow-motion contemplative exercise that is associated with improvements in sensorimotor measures, including decreased force variability, enhanced tactile acuity, and improved proprioception, especially in elderly populations. Here, we carried out two studies evaluating the effect of TC practice on measures associated with sensorimotor processing. In study 1, we evaluated TC’s effects on an oscillatory parameter associated with motor function, beta rhythm (15-30 Hz coherence, focusing specifically on beta rhythm intermuscular coherence (IMC, which is tightly coupled to beta corticomuscular coherence (CMC. We utilized electromyography (EMG to compare beta IMC in older TC practitioners with age-matched controls, as well as novices with advanced TC practitioners. Given previous findings of elevated, maladaptive beta coherence in older subjects, we hypothesized that increased TC practice would be associated with a monotonic decrease in beta IMC, but rather discovered that novice practitioners manifested higher beta IMC than both controls and advanced practitioners, forming an inverted U-shaped practice curve. This finding suggests that TC practice elicits complex changes in sensory and motor processes over the developmental lifespan of TC training. In study 2, we focused on somatosensory (e.g., tactile and proprioceptive responses to the Rubber Hand Illusion (RHI in a middle-aged TC group, assessing whether responses to the illusion became dampened with greater cumulative practice. As hypothesized, TC practice was associated with decreased likelihood to misattribute tactile stimulation during the RHI to the rubber hand, although there was no effect of TC practice on measures of proprioception or on subjective reports of ownership. These studies provide preliminary evidence that TC practice modulates beta network coherence in a non-linear fashion, perhaps as a result of the focus on not only efferent motor but also afferent sensory

  8. Late effects from whole body irradiation and protection by chemical and biological agents. A review

    Energy Technology Data Exchange (ETDEWEB)

    Maisin, J.R. [Catholic Univ. of Louvain, Brussels (Belgium); Gerber, G.B.

    2000-07-01

    This review described studies attempting to reduce damage of exposure to ionizing radiation with an application of chemical or biological agents by illustrating authors' data to point out which possibilities such protectors might hold in future. Authors described their studies on mice exposed to a single or fractionated dose of X-rays at the Belgian Atomic Center at Mol. Mice were irradiated with 250 kV of X-rays at a dose rate of 1 Gy/min or underwent the fractionated irradiation of 1-week intervals with total dose of 2-25 Gy. Before irradiation, some animals were given glutathione, mercaptoethylamine, cystein, serotonine-creatine, 2{beta}-aminoethylisothiuronium, and other agents, alone or as a mixture. Results indicated that radioprotectors reduced many specific late diseases to different degrees together with protection against tumor induction which other investigators had shown. Future prospects were considered for ideal radioprotectors and searches for new radioprotectors and for combination of biological agents (e.g., cytokines with polysaccharides or prostaglandins) were described. (K.H.)

  9. The biologically effective dose in inhalation nanotoxicology.

    Science.gov (United States)

    Donaldson, Ken; Schinwald, Anja; Murphy, Fiona; Cho, Wan-Seob; Duffin, Rodger; Tran, Lang; Poland, Craig

    2013-03-19

    In all branches of toxicology, the biologically effective dose (BED) is the fraction of the total dose of a toxin that actually drives any toxic effect. Knowledge of the BED has a number of applications including in building structure-activity relationships, the selection of metrics, the design of safe particles, and the determination of when a nanoparticle (NP) can be considered to be "new" for regulatory purposes. In particle toxicology, we define the BED as "the entity within any dose of particles in tissue that drives a critical pathophysiogically relevant form of toxicity (e.g., oxidative stress, inflammation, genotoxicity, or proliferation) or a process that leads to it." In conventional chemical toxicology, researchers generally use the mass as the metric to describe dose (such as mass per unit tissue or cells in culture) because of its convenience. Concentration, calculated from mass, may also figure in any description of dose. In the case of a nanoparticle dose, researchers use either the mass or the surface area. The mass of nanoparticles is not the only driver of their activity: the surfaces of insoluble particles interact with biological systems, and soluble nanoparticles can release factors that interact with these systems. Nanoparticle shape can modify activity. In this Account, we describe the current knowledge of the BED as it pertains to different NP types. Soluble toxins released by NPs represent one potential indicator of BED for wholly or partially soluble NPs composed of copper or zinc. Rapid dissolution of these NPs into their toxic ions in the acidic environment of the macrophage phagolysosome causes those ions to accumulate, which leads to lysosome destabilization and inflammation. In contrast, soluble NPs that release low toxicity ions, such as magnesium oxide NPs, are not inflammogenic. For insoluble NPs, ζ potential can serve as a BED measurement because the exposure of the particle surface to the acidic milieu of the phagolysosome and

  10. Effects of modified {beta}-cyclodextrin on thermal stability and conformation of lysozyme

    Energy Technology Data Exchange (ETDEWEB)

    Kamiyama, Tadashi, E-mail: kamiyama@chem.kindai.ac.jp [Department of Chemistry, School of Science and Engineering, Kinki University, Kowakae 3-4-1, Higashi-Osaka, Osaka 577-8502 (Japan); Satoh, Megumi; Tateishi, Takahiro; Nojiri, Tomoaki; Takeuchi, Daisuke; Kimura, Takayoshi [Department of Chemistry, School of Science and Engineering, Kinki University, Kowakae 3-4-1, Higashi-Osaka, Osaka 577-8502 (Japan)

    2012-03-20

    Highlights: Black-Right-Pointing-Pointer Effects of cyclodextrin on stability and conformation of lysozyme were clarified. Black-Right-Pointing-Pointer The CD influences the hydrophobic interaction of lysozyme by the inclusion. Black-Right-Pointing-Pointer The CD relatively destabilized the folded state by stabilizing the unfolded state. Black-Right-Pointing-Pointer The destabilization depends on the concentration and the substituent of CD. Black-Right-Pointing-Pointer The conformation of lysozyme was more spread at unfolded state by inclusion of CD. - Abstract: Effects of cyclic oligosaccharide cyclodextrin (CD) on stability and conformation of lysozyme were clarified thermodynamically and rheologically by DSC, viscosity, and circular dichroism measurements. The modified {beta}-CD relatively destabilized the folded state of lysozyme by stabilizing the unfolded state due to inclusion of hydrophobic part into the hydrophobic interior of CD. The order of higher destabilization effect was acetyl-{beta}-CD > methyl-{beta}-CD > hydroxypropyl-{beta}-CD. Apparent number of bound CD to unfolded state for methyl-, hydroxypropyl-, and acetyl-{beta}-CD is 6.7 {+-} 0.7, 4.2 {+-} 1.1, and 18.6 {+-} 4.3 and the binding constant is 5.5 {+-} 0.8, 6.7 {+-} 2.4, and 4.4 {+-} 1.2 L mol{sup -1}, respectively. The viscosity for unfolded state was increased with an increase in the each modified {beta}-CD concentration, suggesting that the inclusion of CD on a part of hydrophobic core at unfolded state leads to break the hydrophobic core, then lysozyme would be more spread structure. The substituent of CD can accelerate instability by directly breaking hydrogen bond and/or can restrain instability by increase in hydrophobic interaction. The fact that the each modified CDs has different destabilization effect shows a possibility to control the stability of protein by the substitution of CD.

  11. Cell Biology of Thiazide Bone Effects

    Science.gov (United States)

    Gamba, Gerardo; Riccardi, Daniela

    2008-09-01

    The thiazide-sensitive Na+:Cl- cotransporter (NCC) is the major pathway for salt reabsorption in the mammalian kidney. The activity of NCC is not only related to salt metabolism, but also to calcium and magnesium homeostasis due to the inverse relationship between NCC activity and calcium reabsorption. Hence, the thiazide-type diuretics that specifically block NCC have been used for years, not only for treatment of hypertension and edematous disease, but also for the management of renal stone disease. Epidemiological studies have shown that chronic thiazide treatment is associated with higher bone mineral density and reduced risk of bone fractures, which can only partly be explained in terms of their effects on the kidney. In this regard, we have recently shown that NCC is expressed in bone cells and that inhibition of NCC in bone, either by thiazides or by reduction of NCC protein with specific siRNA, is associated with increased mineralization in vitro. These observations open a field of study to begin to understand the cell biology of the beneficial effects of thiazides in bone.

  12. [Effect of synthetic cyclopentane beta,beta'-triketones on amino acid metabolism in roots of buckwheat (Fagopyrum esculentum Moench.) seedlings].

    Science.gov (United States)

    Demina, E A; Tishchenko, L Ia; Shestak, O P; Novikov, V L; Anisimov, M M

    2009-01-01

    Germination of buckwheat seeds in solutions of synthetic mono- and tricyclic cyclopentane-containing beta,beta'-triketones of various concentrations was accompanied by inhibition of seedling root growth and changes in the contents of glutamate, gamma-aminobutyric acid, proline, glutamine, and alanine. The monocyclic triketone also affected the amount of isoleucine. It is likely that the increase in proline content is a nonspecific response significant for enhancing stress tolerance in seedlings.

  13. The effects of plasma beta and anisotropy instabilities on the dynamics of reconnecting magnetic fields in the heliosheath

    CERN Document Server

    Schoeffler, K M; Swisdak, M

    2011-01-01

    The plasma {\\beta} (the ratio of the plasma pressure to the magnetic pressure) of a system can have a large effect on its dynamics as high {\\beta} enhances the effects of pressure anisotropies. We investigate the effects of {\\beta} in a system of stacked current sheets that break up into magnetic islands due to magnetic reconnection. We find significant differences between {\\beta} 1. At low {\\beta} growing magnetic islands are modestly elongated and become round as contraction releases magnetic stress and reduces magnetic energy. At high {\\beta} the increase of the parallel pressure in contracting islands causes saturation of modestly elongated islands as island cores approach the marginal firehose condition. Only highly elongated islands reach finite size. The kinking associated with the Weibel and firehose instabilities prevents full contraction of these islands, leading to a final state of highly elongated islands in which further reconnection is suppressed. The results are directly relevant to reconnecti...

  14. Potential antifertility agents. 6. Synthesis and biological activities of optical isomers of 4 beta-(p-methozyphenyl)-2 beta-methylcyclohexane-alpha-carboxylic acid and related compounds.

    Science.gov (United States)

    Crenshaw, R R; Jenks, T A; Luke, G M; Bialy, G

    1974-12-01

    The optical isomers of the title compound were synthesized and the biological potencies of the two enantiomers were compared. There was essentially no difference in their hypocholesterolemic activities, as had been predicted, and little or no difference between their uterotropic potencies. The approximately equal uterotropic activities seen with the enantiomers is explained in terms of stereochemical requirements at the receptor level for an estrogenic response. A working model of an estrogenic receptor is proposed. An accompanying paper provides support for the proposed model.

  15. Biological effect and tumor risk of diagnostic x-rays. The ''war of the theories''; Biologische Wirkung und Tumorrisiko diagnostischer Roentgenstrahlen. Der ''Krieg der Modelle''

    Energy Technology Data Exchange (ETDEWEB)

    Selzer, E.; Hebar, A. [Medizinische Universitaet Wien, Abteilung fuer Strahlenbiologie, Klinik fuer Strahlentherapie, Wien (Austria)

    2012-10-15

    Since the introduction of ionizing radiation as a treatment and diagnostic tool in humans, scientists have been trying to estimate its side effects and potential health risks. There is now ample evidence for the principal existence of a direct relationship between higher doses and the risks of side effects. Most of the uncertainties lie in the field of low-dose effects especially with respect to the risk of cancer induction. Low-dose effects are usually of relevance in diagnostic medicine while high-dose radiation effects are typically observed after radiotherapeutic treatment for cancer or after nuclear accidents. The current state of the ''war of theories'' may be summarized as follows: one group of scientists and health regulatory officials favors the hypothesis that there is no threshold dose, i.e. the linear-no-threshold hypothesis (LNT) of radiation which can be regarded as safe. On the contrary, the critics of this hypothesis suggest that the risks of doses below 50 mSv are not measurable or even of clinical relevance and are not adequately described by a linear dose-response relationship. The aim of this article is to summarize the major unresolved issues in this field. Arguments are presented why the validity of the LNT model in the low-dose range should be regarded as at least inconsistent and is thus questionable. (orig.) [German] Seit der Einfuehrung ionisierender Strahlen als ein Mittel zur Behandlung und Diagnose beim Menschen haben Wissenschaftler versucht, ihre Nebenwirkungen und potenziellen Risiken fuer die Gesundheit einzuschaetzen. Es gibt nun ausreichende Evidenz fuer das grundsaetzliche Vorliegen einer direkten Beziehung zwischen hoeheren Dosen und Nebenwirkungsrisiken. Die meisten Unsicherheiten liegen auf dem Gebiet der Niedrigdosisforschung v. a. im Hinblick auf das Risiko der Induktion von Krebs. Niedrigdosiseffekte sind ueblicherweise von Bedeutung in der diagnostischen Medizin, waehrend Hochdosisbestrahlungseffekte

  16. Crystallization and preliminary X-ray analysis of beta-alanine synthase from the yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Dobritzsch, D.; Gojkovic, Zoran; Andersen, Birgit

    2003-01-01

    In eukaryotes and some bacteria, the third step of reductive pyrimidine catabolism is catalyzed by beta-alanine synthase (EC 3.5.1.6). Crystals of the recombinant enzyme from the yeast Saccharomyces kluyveri were obtained using sodium citrate as a precipitant. The crystals belong to space group P2......(1) (unit-cell parameters a=117.2, b=77.1, c=225.5 Angstrom, beta=95.0degrees) and contain four homodimers per asymmetric unit. Data were collected to 2.7 Angstrom resolution. Introduction of heavy atoms into the crystal lattice induced a different set of unit-cell parameters (a=61.0, b=77.9, c=110.......1 Angstrom, beta=97.2degrees) in the same space group P2(1), with only one homodimer per asymmetric unit....

  17. What Makes Biology Learning Difficult and Effective: Students' Views

    Science.gov (United States)

    Cimer, Atilla

    2012-01-01

    The present study aims to determine the biological topics that students have difficulties learning, the reasons why secondary school students have difficulties in learning biology, and ways to improve the effectiveness of students' biology learning. For these purposes, a self-administered questionnaire including three open-ended questions was…

  18. Current status of the studies of biological objects by the time-resolved X-ray diffraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Aul' chenko, V.M. [Budker Institute of Nuclear Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation); Bukin, M.A. [Budker Institute of Nuclear Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation); Vazina, A.A. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino (Russian Federation); Gadzhiev, A.M. [Karaev Institute of Physiology, National Academy of Sciences of Azerbaijan, AzNas, 2, Sharifzade str., Baku, AZ1100 Azerbaijan (Azerbaijan)]. E-mail: agadzhiev@bakinter.net; Korneev, B.N. [Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino (Russian Federation); Sergienko, P.M. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino (Russian Federation); Titov, V.M. [Budker Institute of Nuclear Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation); Tolochko, B.P. [Institute of Solid State Chemistry and Mechanochemistry, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation); Sheromov, M.A. [Budker Institute of Nuclear Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2005-05-01

    The methodological and technical aspects of the biological objects study by the time-resolved X-ray diffraction technique are described with reference to muscle contraction. The results of relevant investigations into the structural dynamics of a living muscle during its contraction are presented.

  19. Antiteratogenic Effects of beta-Carotene in Cultured Mouse Embryos Exposed to Nicotine

    OpenAIRE

    C. Lin; Yon, J. M.; Jung, A.Y.; Lee, J. G.; Jung, K. Y.; Lee, B.J.; Yun, Y.W.; Nam, S Y

    2013-01-01

    After maternal intake, nicotine crosses the placental barrier and causes severe embryonic disorders and fetal death. In this study, we investigated whether beta -carotene has a beneficial effect against nicotine-induced teratogenesis in mouse embryos (embryonic day 8.5) cultured for 48 h in a whole embryo culture system. Embryos exposed to nicotine (1 mM) exhibited severe morphological anomalies and apoptotic cell death, as well as increased levels of TNF- alpha , IL-1 beta , and caspase 3 mR...

  20. Adsorption and displacement effects in the gas-chromatography of metal beta-diketonates.

    Science.gov (United States)

    Uden, P C; Jenkins, C R

    1969-07-01

    A detailed study of the gas chromatography of the aluminium(III), chromium(III) and iron(III) beta-diketonates has shown that their elution and separation characteristics arise from a number of adsorptive effects. Conditions of optimal peak shape for individual compounds are established by varying Chromatographie parameters, and the adsorption of one metal chelate on a column and its subsequent displacement by another chelate are investigated. The chromatography of iron(III) beta-diketonates is seen to be further complicated by gradual elution of a portion of the chelate before the rest of the sample.

  1. The Effects of Tai Chi Practice on Intermuscular Beta Coherence and the Rubber Hand Illusion.

    Science.gov (United States)

    Kerr, Catherine E; Agrawal, Uday; Nayak, Sandeep

    2016-01-01

    Tai Chi (TC) is a slow-motion contemplative exercise that is associated with improvements in sensorimotor measures, including decreased force variability, enhanced tactile acuity, and improved proprioception, especially in elderly populations. Here, we carried out two studies evaluating the effect of TC practice on measures associated with sensorimotor processing. In study 1, we evaluated TC's effects on an oscillatory parameter associated with motor function, beta rhythm (15-30 Hz) coherence, focusing specifically on beta rhythm intermuscular coherence (IMC), which is tightly coupled to beta corticomuscular coherence (CMC). We utilized electromyography (EMG) to compare beta IMC in older TC practitioners with age-matched controls, as well as novices with advanced TC practitioners. Given previous findings of elevated, maladaptive beta coherence in older subjects, we hypothesized that increased TC practice would be associated with a monotonic decrease in beta IMC, but rather discovered that novice practitioners manifested higher beta IMC than both controls and advanced practitioners, forming an inverted U-shaped practice curve. This finding suggests that TC practice elicits complex changes in sensory and motor processes over the developmental lifespan of TC training. In study 2, we focused on somatosensory (e.g., tactile and proprioceptive) responses to the rubber hand illusion (RHI) in a middle-aged TC group, assessing whether responses to the illusion became dampened with greater cumulative practice. As hypothesized, TC practice was associated with decreased likelihood to misattribute tactile stimulation during the RHI to the rubber hand, although there was no effect of TC practice on measures of proprioception or on subjective reports of ownership. These studies provide preliminary evidence that TC practice both modulates beta network coherence in a non-linear fashion, perhaps as a result of the focus on not only efferent motor but also afferent sensory activity

  2. Evaluation of some selected vaccines and other biological products irradiated by gamma rays, electron beams and X-rays

    Science.gov (United States)

    May, J. C.; Rey, L.; Lee, Chi-Jen

    2002-03-01

    Molecular sizing potency results are presented for irradiated samples of one lot of Haemophilus b conjugate vaccine, pneumococcal polysaccharide type 6B and typhoid vi polysaccharide vaccine. The samples were irradiated (25 kGy) by gamma rays, electron beams and X-rays. IgG and IgM antibody response in mice test results (ELISA) are given for the Hib conjugate vaccine irradiated at 0°C or frozen in liquid nitrogen.

  3. Evaluation of some selected vaccines and other biological products irradiated by gamma rays, electron beams and X-rays

    Energy Technology Data Exchange (ETDEWEB)

    May, J.C. E-mail: may@cber.fda.gov; Rey, L.; Lee, C.-J

    2002-03-01

    Molecular sizing potency results are presented for irradiated samples of one lot of Haemophilus b conjugate vaccine, pneumococcal polysaccharide type 6B and typhoid vi polysaccharide vaccine. The samples were irradiated (25 kGy) by gamma rays, electron beams and X-rays. IgG and IgM antibody response in mice test results (ELISA) are given for the Hib conjugate vaccine irradiated at 0 deg. C or frozen in liquid nitrogen.

  4. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements.

    Science.gov (United States)

    Pina, S; Vieira, S I; Rego, P; Torres, P M C; da Cruz e Silva, O A B; da Cruz e Silva, E F; Ferreira, J M F

    2010-09-07

    The core aim of this study was to investigate zinc (Zn)- and zinc and strontium (ZnSr)-containing brushite-forming beta-tricalcium phosphate (TCP) cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line) as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP) activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS) as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  5. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements

    Directory of Open Access Journals (Sweden)

    S Pina

    2010-09-01

    Full Text Available The core aim of this study was to investigate zinc (Zn- and zinc and strontium (ZnSr-containing brushite-forming beta-tricalcium phosphate (TCP cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS® as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  6. Antiteratogenic Effects of beta-Carotene in Cultured Mouse Embryos Exposed to Nicotine

    NARCIS (Netherlands)

    Lin, C.; Yon, J.M.; Jung, A.Y.; Lee, J.G.; Jung, K.Y.; Lee, B.J.; Yun, Y.W.; Nam, S.Y.

    2013-01-01

    After maternal intake, nicotine crosses the placental barrier and causes severe embryonic disorders and fetal death. In this study, we investigated whether beta -carotene has a beneficial effect against nicotine-induced teratogenesis in mouse embryos (embryonic day 8.5) cultured for 48 h in a whole

  7. X-ray phase microtomography with a single grating for high-throughput investigations of biological tissue.

    Science.gov (United States)

    Zdora, Marie-Christine; Vila-Comamala, Joan; Schulz, Georg; Khimchenko, Anna; Hipp, Alexander; Cook, Andrew C; Dilg, Daniel; David, Christian; Grünzweig, Christian; Rau, Christoph; Thibault, Pierre; Zanette, Irene

    2017-02-01

    The high-throughput 3D visualisation of biological specimens is essential for studying diseases and developmental disorders. It requires imaging methods that deliver high-contrast, high-resolution volumetric information at short sample preparation and acquisition times. Here we show that X-ray phase-contrast tomography using a single grating can provide a powerful alternative to commonly employed techniques, such as high-resolution episcopic microscopy (HREM). We present the phase tomography of a mouse embryo in paraffin obtained with an X-ray single-grating interferometer at I13-2 Beamline at Diamond Light Source and discuss the results in comparison with HREM measurements. The excellent contrast and quantitative density information achieved non-destructively and without staining using a simple, robust setup make X-ray single-grating interferometry an optimum candidate for high-throughput imaging of biological specimens as an alternative for existing methods like HREM.

  8. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  9. Biological Effects on the Source of Geoneutrinos

    Science.gov (United States)

    Sleep, Norman H.; Bird, Dennis K.; Rosing, Minik T.

    2013-11-01

    Detection of antineutrinos from U and Th series decay within the Earth (geoneutrinos) constrains the absolute abundance of these elements. Marine detectors will measure the ratio over the mantle beneath the site and provide spatial averaging. The measured mantle Th/U may well be significantly below its bulk earth value of 4; Pb isotope measurements on mantle-derived rocks yield low Th/U values, effectively averaged over geological time. The physics of the modern biological process is complicated, but the net effect is that much of the U in the mantle comes from subducted marine sediments and subducted upper oceanic crust. That is, U subducts preferentially relative to Th. Oxygen ultimately from photosynthesis oxidizes U(IV) to U(VI), which is soluble during weathering and sediment transport. Dissolved U(VI) reacts with FeO in the oceanic crust and organic carbon within sediments to become immobile U(IV). These deep marine rocks are preferentially subducted relative to Th(IV)-bearing continental margin rocks. Ferric iron from anoxygenic photosynthesis and oxygen in local oases likely mobilized some U during the Archean Era when there was very little O2 in the air. Conversely, these elements behave similarly in the absence of life, where the elements occur as U(IV) and Th(IV), which do not significantly fractionate during igneous processes. Neither do they fractionate during weathering, as they are essentially insoluble in water in surface environments. Th(IV) and U(IV) remain in solid clay-sized material. Overall, geoneutrino data constrain the masses of mantle chemical and isotopic domains recognized by studies of mantle-derived rocks and show the extent of recycling into the mantle over geological time.

  10. Effect of environmental estrogens on IL-1beta promoter activity in a macrophage cell line.

    Science.gov (United States)

    Ruh, M F; Bi, Y; Cox, L; Berk, D; Howlett, A C; Bellone, C J

    1998-10-01

    Environmental estrogens or estrogen disrupters have recently received a great deal of attention because of their potential health impact on reproductive tissues. Few, if any, studies have been made on the impact of these compounds on the immune system. We sought to determine the activities of various environmental estrogens on the modulation of the interleukin-1beta (IL-1beta) gene in a model monocytic cell line, hER + IL-1beta-CAT+. This cell line stably transfected with the human estrogen receptor, and an IL-1beta promoter construct fused to the CAT reporter gene allows us to monitor the effect of estrogenic compounds on IL-1beta promoter activity. 17beta-estradiol (E2) markedly enhanced lipopolysaccharide- (LPS) induced IL-1beta promoter-driven CAT activity in a dose-dependent manner. The mycotoxins alpha-zearalenol and zearalenone both exhibited full agonist activity, but at lower potencies, with EC50 values of 1.8 and 54 nM, respectively, compared with E2 at 0.5 nM. In addition, genistein was a very low-potency agonist, having an EC50 of 1.5 microM. Similar to the E2 response, the slope factors for alpha-zearalenol, zearalenone, and genistein were close to 3.0, suggesting positive cooperativity in the estrogenic response. The activity of the mycotoxins appeared to be mediated through the estrogen receptor, since both the antiestrogens H1285 and ICI 182,780 effectively inhibited their agonist activity in a dose-dependent manner. Representative environmental estrogenic compounds both from plant and industrial sources were also tested. Unlike the mycoestrogens, none of the compounds, with the exception of genistein, synergized with LPS to enhance IL-1beta promoter activity. When tested for antiestrogenic activity, the industrial compound 4-octylphenol was able to antagonize the response to E2; however, the response was three orders of magnitude less potent than H 1285. Naringenin, a plant flavonoid, showed little or no ability to antagonize the response to E2

  11. Effects of transforming growth factor-[beta] and budesonide on mitogen-activated protein kinase activation and apoptosis in airway epithelial cells.

    Science.gov (United States)

    Pelaia, Girolamo; Cuda, Giovanni; Vatrella, Alessandro; Fratto, Donatella; Grembiale, Rosa D; Tagliaferri, Pierosandro; Maselli, Rosario; Costanzo, Francesco S; Marsico, Serafino A

    2003-07-01

    Airway epithelial cells play a central role in the inflammatory, apoptotic, and remodeling processes associated with asthma. Within this context, a key function is exerted by transforming growth factor-beta (TGF-beta), whose biological effects are mediated at least in part by mitogen-activated protein kinases (MAPKs). The aim of our study was to investigate, in primary cultures of human bronchial epithelial cells (HBEC), the effects of TGF-beta (10 ng/ml) on both MAPK activation and apoptosis, in the presence or absence of a pretreatment with budesonide (10-8 M). MAPK activation was detected by Western blotting, using anti-phospho-MAPK monoclonal antibodies, which specifically recognize the phosphorylated, active forms of these enzymes. Apoptosis was assayed by caspase-3 activation and fluorescence microscopy, using annexin-V (An-V) and propidium iodide (PI) as markers of cell death. Our results show that TGF-beta induced a marked ( reverse similar 9-fold) increase in p38 MAPK phosphorylation, and also dramatically enhanced cell death, which was completely prevented by specific MAPK inhibitors. Both MAPK activation and apoptosis were effectively inhibited by budesonide (BUD), thereby suggesting that the powerful antiapoptotic action of inhaled glucocorticoids may be very important for their protective role against epithelial injury, which represents a key pathogenic event in asthma.

  12. Synthesis and biological activity of beta-glucuronyl carbamate-based prodrugs of paclitaxel as potential candidates for ADEPT

    NARCIS (Netherlands)

    deBont, DBA; Leenders, RGG; Haisma, HJ; vanderMeulenMuileman, [No Value; Scheeren, HW

    1997-01-01

    The syntheses of prodrugs of paclitaxel, which can be used in ADEPT in order to target paclitaxel towards tumor cells, are described. The prodrugs 1 and 2a,b consist of a spacer molecule connected via a carbamate linkage to a beta-glucuronic acid. The spacer molecule is also connected via an ester l

  13. Synthesis and biological evaluation of potent {alpha}{sub v}{beta}{sub 3}-integrin receptor antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, Ingrid [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands) and Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht (Netherlands)]. E-mail: i.dijkgraaf@nucmed.umcn.nl; Kruijtzer, John A.W. [Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht (Netherlands); Frielink, Cathelijne [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Soede, Annemieke C. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Hilbers, Hans W. [Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht (Netherlands); Oyen, Wim J.G. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Corstens, Frans H.M. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Liskamp, Rob M.J. [Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht (Netherlands); Boerman, Otto C. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands)

    2006-11-15

    Introduction: {alpha}{sub v}{beta}{sub 3} Integrin is expressed in sprouting endothelial cells in growing tumors, whereas it is absent in quiescent blood vessels. In addition, various tumor cell types express {alpha}{sub v}{beta}{sub 3} integrin. {alpha}{sub v}{beta}{sub 3} Integrin, a transmembrane heterodimeric protein, binds to the arginine-glycine-aspartic acid (RGD) amino acid sequence of extracellular matrix proteins such as vitronectin and plays a pivotal role in invasion, proliferation and metastasis. Due to the selective expression of {alpha}{sub v}{beta}{sub 3} integrin in tumors, radiolabeled RGD peptides and peptidomimetics are attractive candidates for tumor targeting. Methods: A cyclic RGD peptide, a peptoid-peptide hybrid, an all-peptoid and a peptidomimetic compound were synthesized, conjugated with 1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA) and radiolabeled with {sup 111}In. Their in vitro and in vivo {alpha}{sub v}{beta}{sub 3}-binding characteristics were determined. Results: IC{sub 5} values were 236 nM for DOTA-E-c(RGDfK), 219 nM for DOTA-peptidomimetic, >10 mM for DOTA-all-peptoid and 9.25 mM for the peptoid-peptide hybrid DOTA-E-c(nRGDfK). {sup 111}In-labeled compounds, except for [{sup 111}In]DOTA-all-peptoid, showed specific uptake in human {alpha}{sub v}{beta}{sub 3}-expressing tumors xenografted in athymic mice. Tumor uptake for [{sup 111}In]DOTA-E-c(RGDfK) was 1.73{+-}0.4% ID/g (2 h postinjection) and that of [{sup 111}In]DOTA-peptidomimetic was 2.04{+-}0.3% ID/g. Tumor uptake for the peptoid-peptide hybrid [{sup 111}In]DOTA-E-c(nRGDfK) was markedly lower (0.45{+-}0.07% ID/g). The all-peptoid [{sup 111}In]DOTA-E-c(nRGnDnFnK) did not show specific uptake in tumors (0.11{+-}0.04% ID/g). Conclusions: The peptidomimetic compound and the cyclic RGD peptide have a high affinity for {alpha}{sub v}{beta}{sub 3} integrin, and these compounds have better tumor-targeting characteristics than the

  14. Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Jose D.S.; Franca, Elvis J.; Magalhaes, Marcelo R.L.; Almeida, Marcio E.S.; Hazin, Clovis A., E-mail: dan-paiva@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: maensoal@yahoo.com.br, E-mail: chazin@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

  15. Gamma ray bursts, neutron star quakes, and the Casimir effect

    CERN Document Server

    Carlson, C; Pérez-Mercader, J; Carlson, C; Goldman, T; Perez-Mercader, J

    1994-01-01

    We propose that the dynamic Casimir effect is a mechanism that converts the energy of neutron starquakes into \\gamma--rays. This mechanism efficiently produces photons from electromagnetic Casimir energy released by the rapid motion of a dielectric medium into a vacuum. Estimates based on the cutoff energy of the gamma ray bursts and the volume involved in a starquake indicate that the total gamma ray energy emission is consonant with observational requirements.

  16. Breeding biology of muscovy duck (Cairina moschata) under natural incubation: the use of the weibull function and a beta-binomial model to predict nest hatchability

    Science.gov (United States)

    Harun; Draisma; Frankena; Veeneklaas; Van Kampen M

    1999-05-07

    In this paper we tested the Weibull function and beta-binomial distribution to analyse and predict nest hatchability, using empirical data on hatchability in Muscovy duck (Cairina moschata) eggs under natural incubation (932 successfully incubated nests and 11 822 eggs). The estimated parameters of the Weibull function and beta-binomial model were compared with the logistic regression analysis. The maximum likelihood estimation of the parameters was used to quantify simultaneously the influence of the nesting behaviour and the duration of the reproduction cycle on hatchability. The estimated parameters showed that the hatchability was not affected in natural dump nests, but in artificial dump nests and in nests with non-term eggs the hatchability was reduced by 10 and 25%, respectively. Similar results were obtained using logistic regression. Both models provided a satisfactory description of the observed data set, but the beta-binomial model proved to have more parameters with practical and biological meaningful interpretations, because this model is able to quantify and incorporate the unexplained variation in a single parameter theta (which is a variance measure). Copyright 1999 Academic Press.

  17. [Various aspects of IL-1 biological activity. II. IL-1 beta in diseases and the Central Nervous System].

    Science.gov (United States)

    Wieczorek, Marek

    2009-01-01

    Precise understanding of the mechanisms of reciprocal relations between the nervous and the immune systems, has been the subject of numerous studies for the recent two decades. These mechanisms are significant, particularly at the stage of early response to bacterial, parasite, or viral infections. They are also essential from the medical point of view, as they may help in the development of the new methods of treatment of infectious diseases, and also may provide better methods to neutralize possible side effects of the therapy. As it is commonly understood, both forms of IL-1 (alpha and beta), play an important role as a signaling molecules in these mechanisms. Regardless of the route of administration, they cause to the activation of the brain neurotransmitters, and the hypothalamo-pituitary-adrenal-axis (HPA). The HPA response induced by activity of the immune system is a normal, physiological phenomenon with essential meaning. It gives the negative feedback where glucocorticoids, released from the adrenal cortex, inhibit activity of the immune system, and by this reduce the probability of the over-stimulation of this system and its self-aggression. Therefore, precise recognition of the mechanism which is the indicator of influence of cytokines on the brain and also leads to initiate that response has a significant scientific and practical meaning. Also, the two mechanisms are probably the most important, and under appropriate conditions could complement each other. These are enzymatic and neural ways by which immune system influences the brain. The former predicts, that Il-1 influences the tissue, stimulating them to the synthesis, via the cyclooxygenases (COX) activation, and release molecules such as prostaglandines (especially PGE2), which have the ability to penetrate the brain barrier. The latter assumes that IL-1, directly or indirectly, can influence the peripheral nerves (the most important is probably the vagus nerve), which afferent sensory endings

  18. Thymosin beta 4 induces hair growth via stem cell migration and differentiation.

    Science.gov (United States)

    Philp, Deborah; St-Surin, Sharleen; Cha, Hee-Jae; Moon, Hye-Sung; Kleinman, Hynda K; Elkin, Michael

    2007-09-01

    Thymosin beta 4 is a small 43-amino-acid molecule that has multiple biological activities, including promotion of cell migration angiogenesis, cell survival, protease production, and wound healing. We have found that thymosin beta 4 promotes hair growth in various rat and mice models including a transgenic thymosin beta 4 overexpressing mouse. We have also determined the mechanism by which thymosin beta 4 acts to promote hair growth by examining its effects on follicle stem cell growth, migration, differentiation, and protease production.

  19. Effects of beta-blockers on heart failure with preserved ejection fraction: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Feng Liu

    Full Text Available BACKGROUND: Effects of beta-blockers on the prognosis of the heart failure patients with preserved ejection fraction (HFpEF remain controversial. The aim of this meta-analysis was to determine the impact of beta-blockers on mortality and hospitalization in the patients with HFpEF. METHODS: A search of MEDLINE, EMBASE, and the Cochrane Library databases from 2005 to June 2013 was conducted. Clinical studies reporting outcomes of mortality and/or hospitalization for patients with HFpEF (EF ≥ 40%, being assigned to beta-blockers treatment and non-beta-blockers control group were included. RESULTS: A total of 12 clinical studies (2 randomized controlled trials and 10 observational studies involving 21,206 HFpEF patients were included for this meta-analysis. The pooled analysis demonstrated that beta-blocker exposure was associated with a 9% reduction in relative risk for all-cause mortality in patients with HFpEF (95% CI: 0.87 - 0.95; P < 0.001. Whereas, the all-cause hospitalization, HF hospitalization and composite outcomes (mortality and hospitalization were not affected by this treatment (P=0.26, P=0.97, and P=0.88 respectively. CONCLUSIONS: The beta-blockers treatment for the patients with HFpEF was associated with a lower risk of all-cause mortality, but not with a lower risk of hospitalization. These finding were mainly obtained from observational studies, and further investigations are needed to make an assertion.

  20. Towards tender X-rays with Zernike phase-contrast imaging of biological samples at 50 nm resolution.

    Science.gov (United States)

    Vartiainen, Ismo; Warmer, Martin; Goeries, Dennis; Herker, Eva; Reimer, Rudolph; David, Christian; Meents, Alke

    2014-07-01

    X-ray microscopy is a commonly used method especially in material science application, where the large penetration depth of X-rays is necessary for three-dimensional structural studies of thick specimens with high-Z elements. In this paper it is shown that full-field X-ray microscopy at 6.2 keV can be utilized for imaging of biological specimens with high resolution. A full-field Zernike phase-contrast microscope based on diffractive optics is used to study lipid droplet formation in hepatoma cells. It is shown that the contrast of the images is comparable with that of electron microscopy, and even better contrast at tender X-ray energies between 2.5 keV and 4 keV is expected.

  1. SIX2 Effects on Wilms Tumor Biology

    Directory of Open Access Journals (Sweden)

    Janene Pierce

    2014-12-01

    Full Text Available Wilms tumor (WT blastema retains gene expression profiles characteristic of the multipotent nephron progenitor pool, or cap mesenchyme (CM, in the developing kidney. As a result, WT blastema and the CM are believed to represent contextual analogues of one another. Sine oculis homeobox 2 (SIX2 is a transcription factor expressed specifically in the CM, provides a critical mechanism for CM self-renewal, and remains persistently active in WT blastema, although its purpose in this childhood malignancy remains unclear. We hypothesized that SIX2, analogous to its function in development, confers a survival pathway to blastema, the putative WT stem cell. To test its functional significance in WT biology, wild-type SIX2 was overexpressed in the human WT cell line, WiT49. After validating this model, SIX2 effects on anchorage-independent growth, proliferation, invasiveness, canonical WNT pathway signaling, and gene expression of specific WNT pathway participants were evaluated. Relative to controls, WiT49 cells overexpressing SIX2 showed significantly enhanced anchorage-independent growth and early-passage proliferation representing surrogates of cell survival. Interestingly, overexpression of SIX2 generally repressed TCF/LEF-dependent canonical WNT signaling, which activates and coordinates both differentiation and stem pathways, but significantly heightened canonical WNT signaling through the survivin promoter, a mechanism that exclusively maintains the stem state. In summary, when overexpressed in a human WT cell line, SIX2 enhances cell survival and appears to shift the balance in WNT/β-catenin signaling away from a differentiation path and toward a stem cell survival path.

  2. The effect of the creatine analogue beta-guanidinopropionic acid on energy metabolism: a systematic review.

    Directory of Open Access Journals (Sweden)

    Inge Oudman

    Full Text Available BACKGROUND: Creatine kinase plays a key role in cellular energy transport. The enzyme transfers high-energy phosphoryl groups from mitochondria to subcellular sites of ATP hydrolysis, where it buffers ADP concentration by catalyzing the reversible transfer of the high-energy phosphate moiety (P between creatine and ADP. Cellular creatine uptake is competitively inhibited by beta-guanidinopropionic acid. This substance is marked as safe for human use, but the effects are unclear. Therefore, we systematically reviewed the effect of beta-guanidinopropionic acid on energy metabolism and function of tissues with high energy demands. METHODS: We performed a systematic review and searched the electronic databases Pubmed, EMBASE, the Cochrane Library, and LILACS from their inception through March 2011. Furthermore, we searched the internet and explored references from textbooks and reviews. RESULTS: After applying the inclusion criteria, we retrieved 131 publications, mainly considering the effect of chronic oral administration of beta-guanidinopropionic acid (0.5 to 3.5% on skeletal muscle, the cardiovascular system, and brain tissue in animals. Beta-guanidinopropionic acid decreased intracellular creatine and phosphocreatine in all tissues studied. In skeletal muscle, this effect induced a shift from glycolytic to oxidative metabolism, increased cellular glucose uptake and increased fatigue tolerance. In heart tissue this shift to mitochondrial metabolism was less pronounced. Myocardial contractility was modestly reduced, including a decreased ventricular developed pressure, albeit with unchanged cardiac output. In brain tissue adaptations in energy metabolism resulted in enhanced ATP stability and survival during hypoxia. CONCLUSION: Chronic beta-guanidinopropionic acid increases fatigue tolerance of skeletal muscle and survival during ischaemia in animal studies, with modestly reduced myocardial contractility. Because it is marked as safe for human

  3. Effect of Ionizing Beta Radiation on the Mechanical Properties of Poly(ethylene under Thermal Stress

    Directory of Open Access Journals (Sweden)

    Bednarik Martin

    2016-01-01

    Full Text Available It was found in this study, that ionizing beta radiation has a positive effect on the mechanical properties of poly(ethylene. In recent years, there have been increasing requirements for quality and cost effectiveness of manufactured products in all areas of industrial production. These requirements are best met with the polymeric materials, which have many advantages in comparison to traditional materials. The main advantages of polymer materials are especially in their ease of processability, availability, and price of the raw materials. Radiation crosslinking is one of the ways to give the conventional plastics mechanical, thermal, and chemical properties of expensive and highly resistant construction polymers. Several types of ionizing radiation are used for crosslinking of polymers. Each of them has special characteristics. Electron beta and photon gamma radiation are used the most frequently. The great advantage is that the crosslinking occurs after the manufacturing process at normal temperature and pressure. The main purpose of this paper has been to determine the effect of ionizing beta radiation on the tensile modulus, strength and elongation of low and high density polyethylene (LDPE and HDPE. These properties were examined in dependence on the dosage of the ionizing beta radiation (non-irradiated samples and those irradiated by dosage 99 kGy were compared and on the test temperature. Radiation cross-linking of LDPE and HDPE results in increased tensile strength and modulus, and decreased of elongation. The measured results indicate that ionizing beta radiation treatment is effective tool for improvement of mechanical properties of LDPE and HDPE under thermal stress.

  4. A comparison of observation-level random effect and Beta-Binomial models for modelling overdispersion in Binomial data in ecology & evolution

    Directory of Open Access Journals (Sweden)

    Xavier A. Harrison

    2015-07-01

    Full Text Available Overdispersion is a common feature of models of biological data, but researchers often fail to model the excess variation driving the overdispersion, resulting in biased parameter estimates and standard errors. Quantifying and modeling overdispersion when it is present is therefore critical for robust biological inference. One means to account for overdispersion is to add an observation-level random effect (OLRE to a model, where each data point receives a unique level of a random effect that can absorb the extra-parametric variation in the data. Although some studies have investigated the utility of OLRE to model overdispersion in Poisson count data, studies doing so for Binomial proportion data are scarce. Here I use a simulation approach to investigate the ability of both OLRE models and Beta-Binomial models to recover unbiased parameter estimates in mixed effects models of Binomial data under various degrees of overdispersion. In addition, as ecologists often fit random intercept terms to models when the random effect sample size is low (<5 levels, I investigate the performance of both model types under a range of random effect sample sizes when overdispersion is present. Simulation results revealed that the efficacy of OLRE depends on the process that generated the overdispersion; OLRE failed to cope with overdispersion generated from a Beta-Binomial mixture model, leading to biased slope and intercept estimates, but performed well for overdispersion generated by adding random noise to the linear predictor. Comparison of parameter estimates from an OLRE model with those from its corresponding Beta-Binomial model readily identified when OLRE were performing poorly due to disagreement between effect sizes, and this strategy should be employed whenever OLRE are used for Binomial data to assess their reliability. Beta-Binomial models performed well across all contexts, but showed a tendency to underestimate effect sizes when modelling non-Beta

  5. Effects of glycine, beta-alanine and diazepam upon morphine-tolerant-dependent mice.

    Science.gov (United States)

    Contreras, E; Tamayo, L

    1980-05-01

    The effects in mice of glycine, beta-alanine and diazepam on the analgesic response to morphine, on the intensity of tolerance and on the physical dependence on the analgesic have been examined. The two amino acids increased the analgesic response to morphine in a dose-related manner. However, both compounds were ineffective in the analgesic test (hot plate) when administered without morphine. Diazepam was ineffective in the analgesic test and it did not alter morphine analgesia, except when administered in a high dose which decreased and analgesic response. Glycine, either in single or repeated doses, did not modify tolerance to morphine, whereas beta-alanine induced a dose-related partial antagonism, which promptly reached a plateau. Diazepam induced a small decrease in the intensity of tolerance to the analgesic. The abstinence syndrome to morphine, induced by naloxone administration to primed mice, was reduced by single doses of glycine or beta-alanine. Diazepam behaved as a weak inhibitor of the abstinence syndrome when administered at a high dose. The potentiation of morphine analgesia and the antagonism of the abstinence syndrome induced by the amino acids may be related to their hyperpolarizing action in the c.n. system. The effects of beta-alanine on morphine tolerance cannot be explained by the same mechanism.

  6. Fast sausage modes in magnetic tubes with continuous transverse profiles: effects of a finite plasma beta

    CERN Document Server

    Chen, Shao-Xia; Xiong, Ming; Yu, Hui; Guo, Ming-Zhe

    2016-01-01

    While standing fast sausage modes in flare loops are often invoked to interpret quasi-periodic pulsations (QPPs) in solar flares, it is unclear as to how they are influenced by the combined effects of a continuous transverse structuring and a finite internal plasma beta ($\\beta_{\\rm i}$). We derive a generic dispersion relation (DR) governing linear sausage waves in straight magnetic tubes for which plasma pressure is not negligible and the density and temperature inhomogeneities of essentially arbitrary form take place in a layer of arbitrary width. Focusing on fast modes, we find that $\\beta_{\\rm i}$ only weakly influences $k_{\\rm c}$, the critical longitudinal wavenumber separating the leaky from trapped modes. Likewise, for both trapped and leaky modes, the periods $P$ in units of the transverse fast time depend only weakly on $\\beta_{\\rm i}$, which is compatible with the fact that the effective wavevectors of fast sausage modes are largely perpendicular to the background magnetic field. However, a weak $...

  7. Probiotic effects of beta-glucuronidase on the peach-potato aphid Myzus persicae (Aphididae).

    Science.gov (United States)

    Cherqui, A; Alla, S; Saguez, J; Doury, G; Sangwan-Norreel, B S; Giordanengo, P

    2003-12-01

    beta-glucuronidase (GUS) is a reporter protein commonly expressed in transgenic plants allowing the visualization of the transformed individuals. In our recent work, we showed that consumption of transformed potato plants expressing this GUS enzyme improves performance of the phloem feeding aphid Myzus persicae. Those results led us to the conclusion that the expression of GUS in potato plants might be responsible for the probiotic effect measured in feeding aphids. In the present paper, artificial diets were used to provide active GUS (10 and 500 microg ml(-1)), inactivated heated GUS (500 microg ml(-1)), glucuronic acid (10, 100 and 500 microg ml(-1)), and bovine serum albumin (500 microg ml(-1)) to M. persicae. Our results reveal that these chemicals provided as food intake might influence the biological parameters of this aphid. Experiments showed a probiotic effect of 500 microg ml(-1) GUS diet, resulting in reduced larval mortality, and increased adult reproduction period and fecundity, which led to an increased population growth potential (r(m)=0.17+/-0.01 versus r(m)=0.12+/-0.03 for aphids fed on control diet). A lower amount of added GUS led to fewer variations, biological parameters being only slightly altered (r(m)=0.14+/-0.03). Statistically similar alterations of the biological parameters were obtained when comparing aphids fed on the diet added with inactivated GUS or the non-structural bovine serum albumin protein (r(m)=0.15+/-0.02 and 0.14+/-0.03, respectively). Feeding assays conducted with glucuronic acid supplemented diets enhanced longevity and nymph production of the adult aphids and reduced larval mortality, resulting in r(m)=0.15+/-0.02 for the highest dose (500 microg ml(-1)). Although 100 microg ml(-1) glucuronate diet did not induce any effect on M. persicae (r(m)=0.12+/-0.03), aphids fed on 10 microg ml(-1) glucuronate diet exhibited unexpected reduced demographic parameters (r(m)=0.10+/-0.03). Immuno-histological analysis showed GUS

  8. Particle induced X-ray emission and ion dose distribution in a biological micro-beam: Geant4 Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Syed Bilal, E-mail: ahmadsb@mcmaster.ca [TAB-104D, Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada); Thompson, Jeroen E., E-mail: Jeroen.thompson@gmail.com [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada); McNeill, Fiona E., E-mail: fmcneill@mcmaster.ca [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada); Byun, Soo Hyun, E-mail: soohyun@mcmaster.ca [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada); Prestwich, William V., E-mail: prestwic@mcmaster.ca [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada)

    2013-01-15

    The goal of a microbeam is to deliver a highly localized and small dose to the biological medium. This can be achieved by using a set of collimators that confine the charged particle beam to a very small spatial area of the order of microns in diameter. By using a system that combines an appropriate beam detection method that signals to a beam shut-down mechanism, a predetermined and counted number of energetic particles can be delivered to targeted biological cells. Since the shutter and the collimators block a significant proportion of the beam, there is a probability of the production of low energy X-rays and secondary electrons through interactions with the beam. There is little information in the biological microbeam literature on potential X-ray production. We therefore used Monte Carlo simulations to investigate the potential production of particle-induced X-rays and secondary electrons in the collimation system (which is predominantly made of tungsten) and the subsequent possible effects on the total absorbed dose delivered to the biological medium. We found, through the simulation, no evidence of the escape of X-rays or secondary electrons from the collimation system for proton energies up to 3 MeV as we found that the thickness of the collimators is sufficient to reabsorb all of the generated low energy X-rays and secondary electrons. However, if the proton energy exceeds 3 MeV our simulations suggest that 10 keV X-rays can escape the collimator and expose the overlying layer of cells and medium. If the proton energy is further increased to 4.5 MeV or beyond, the collimator can become a significant source of 10 keV and 59 keV X-rays. These additional radiation fields could have effects on cells and these results should be verified through experimental measurement. We suggest that researchers using biological microbeams at higher energies need to be aware that cells may be exposed to a mixed LET radiation field and be careful in their interpretation of

  9. Efeito da suplementação de beta-caroteno na pressão arterial de ratos Effect of beta-carotene supplementation on the blood pressure of rats

    Directory of Open Access Journals (Sweden)

    Giselle Santos de Oliveira

    2007-02-01

    detect possible toxic effects or interaction between nutrients and analysis of biological parameters; systolic blood pressure was measured by plethysmography twice a week on alternate days; after the supplementation period, animals were killed and their livers weighed by the Scherle method. RESULTS: Administration of beta-carotene did not alter the animals' biological parameters or cause any toxic effects. Regarding systolic blood pressure, both lineages showed significant results (p<0.05, with the highest dose presenting the best results. The average liver weight was 7.25 (3.2 standard-deviation grams, and the relationship between the average liver weight and body weight was 0.0192 for the hypertensive group. CONCLUSION: Beta-carotene supplementation was effective in controlling and preventing hypertension in rats. The relationship between liver weight and body weight was normal.

  10. Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 beta-xylosidase from Geobacillus thermoleovorans IT-08

    NARCIS (Netherlands)

    Rohman, Ali; van Oosterwijk, Niels; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W.; Puspaningsih, Ni Nyoman Tri

    2007-01-01

    The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-beta-xylanase and beta-xylosidase. beta-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-beta-xylanase into xylose monomers. The beta-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of

  11. Phosphate and HEPES buffers potently affect the fibrillation and oligomerization mechanism of Alzheimer's A{beta} peptide

    Energy Technology Data Exchange (ETDEWEB)

    Garvey, Megan; Tepper, Katharina [Max-Planck-Forschungsstelle fuer Enzymologie der Proteinfaltung, Weinbergweg 22, D-06120 Halle (Saale) (Germany); Haupt, Caroline [Institute fuer Physik, Biophysik, Martin-Luther Universitaet Halle-Wittenberg, Betty-Heimann-Str. 7, D-06120 Halle (Saale) (Germany); Knuepfer, Uwe [Leibniz-Institute for Infection Biology and Natural Product Research, Beutenbergstr. 11a, D-07745 Jena (Germany); Klement, Karolin; Meinhardt, Jessica [Leibniz-Institute for Age Research (FLI), Beutenbergstr. 11, D-07745 Jena (Germany); Horn, Uwe [Leibniz-Institute for Infection Biology and Natural Product Research, Beutenbergstr. 11a, D-07745 Jena (Germany); Balbach, Jochen [Institute fuer Physik, Biophysik, Martin-Luther Universitaet Halle-Wittenberg, Betty-Heimann-Str. 7, D-06120 Halle (Saale) (Germany); Faendrich, Marcus, E-mail: fandrich@enzyme-halle.mpg.de [Max-Planck-Forschungsstelle fuer Enzymologie der Proteinfaltung, Weinbergweg 22, D-06120 Halle (Saale) (Germany); Bio zentrum, Martin-Luther Universitaet Halle-Wittenberg, Weinbergweg 22, D-06120 Halle (Saale) (Germany)

    2011-06-10

    Highlights: {yields} Sodium phosphate buffer accelerated A{beta}(1-40) nucleation relative to HEPES. {yields} A{beta}(1-40) fibrils formed in the two buffers show only minor structural differences. {yields} NMR revealed that A{beta}(1-40) histidine residues mediate buffer dependent changes. -- Abstract: The oligomerization of A{beta} peptide into amyloid fibrils is a hallmark of Alzheimer's disease. Due to its biological relevance, phosphate is the most commonly used buffer system for studying the formation of A{beta} and other amyloid fibrils. Investigation into the characteristics and formation of amyloid fibrils frequently relies upon material formed in vitro, predominantly in phosphate buffers. Herein, we examine the effects on the fibrillation and oligomerization mechanism of A{beta} peptide that occur due solely to the influence of phosphate buffer. We reveal that significant differences in amyloid fibrillation are observed due to fibrillation being initiated in phosphate or HEPES buffer (at physiological pH and temperature). Except for the differing buffer ions, all experimental parameters were kept constant. Fibril formation was assessed using fluorescently monitored kinetic studies, microscopy, X-ray fiber diffraction and infrared and nuclear magnetic resonance spectroscopies. Based on this set up, we herein reveal profound effects on the mechanism and speed of A{beta} fibrillation. The three histidine residues at positions 6, 13 and 14 of A{beta}(1-40) are instrumental in these mechanistic changes. We conclude that buffer plays a more significant role in fibril formation than has been generally acknowledged.

  12. Synchrotron radiation X-ray microfluorescence techniques and biological applications

    Indian Academy of Sciences (India)

    R T Lopes; I Lima; G R Pereira; C A Perez

    2011-02-01

    Synchrotron X-ray imaging systems with fluorescence techniques was developed for biomedical researches in Brazilian Synchrotron Laboratory. An X-ray fluorescence microtomography system was implemented to analyse human prostate and breast samples and an X-ray microfluorescence system was implemented to study bone sites of human and animal samples with and without bone disorders.

  13. Effect of extracellular pH on recombinant alpha1beta2gamma2 and alpha1beta2 GABAA receptors.

    Science.gov (United States)

    Mercik, Katarzyna; Pytel, Maria; Cherubini, Enrico; Mozrzymas, Jerzy W

    2006-08-01

    Recently, we have reported that extracellular protons allosterically modulated neuronal GABA(A) receptors [Mozrzymas, J.W., Zarnowska, E.D., Pytel, M., Mercik, K., 2003a. Modulation of GABA(A) receptors by hydrogen ions reveals synaptic GABA transient and a crucial role of desensitiztion process. Journal of Neuroscience 23, 7981-7992]. However, GABAARs in neurons are heterogeneous and the effect of hydrogen ions depends on the receptor subtype. In particular, gamma2 subunit sets the receptor sensibility to several modulators including protons. However, the mechanisms whereby protons modulate gamma2-containing and gamma2-free GABAARs have not been fully elucidated. To this end, current responses to ultrafast GABA applications were recorded for alpha1beta2gamma2 and alpha1beta2 receptors at different pH values. For both receptor types, increase in pH induced a decrease in amplitudes of currents elicited by saturating [GABA] but this effect was stronger for alpha1beta2 receptors. In the case of alpha1beta2gamma2 receptors, protons strongly affected the current time course due to a down regulation of binding and desensitization rates. This effect was qualitatively similar to that described in neurons. Protons strongly influenced the amplitude of alpha1beta2 receptor-mediated currents but the effect on their kinetics was weak suggesting a predominant direct non-competitive inhibition with a minor allosteric modulation. In conclusion, we provide evidence that extracellular protons strongly affect GABAA receptors and that, depending on the presence of the gamma2 subunit, the modulatory mechanisms show profound quantitative and qualitative differences.

  14. PGC-1alpha and PGC-1beta have both similar and distinct effects on myofiber switching toward an oxidative phenotype

    DEFF Research Database (Denmark)

    Mortensen, Ole Hartvig; Frandsen, Lis; Schjerling, Peter

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma coactivator-1alpha and -1beta (PGC-1alpha and PGC-1beta) were overexpressed by adenovirus-mediated gene transfer in cultures of primary rat skeletal muscle cells derived from neonatal myoblasts. Effects on muscle fiber type transition and metabolism...

  15. Effects of Individualized Assignments on Biology Achievement.

    Science.gov (United States)

    Kremer, Philip L.

    1983-01-01

    Compared detailed (favoring field dependence and induction) and nondetailed (favoring field dependence and deduction) assignments on biology achievement of grade 10 male students (N=95) over a seven-month period. Detailed assignments, employing pictorial and verbal block diagrams and high structure, significantly enhanced learning among some…

  16. The Biological Effects of Nonionizing Radiation.

    Science.gov (United States)

    1981-12-29

    surrounding C-12-81 normal tissues. According to N.W. Bleehan, this was the method used by Hippocrates , with the aid of a hot iron. Hippocrates , by the way, is...temporal pattern of desired increases of tempera - ture in the body; (2) the biological consequences of doing this must be established and evaluated

  17. Technology Rich Biology Labs: Effects of Misconceptions.

    Science.gov (United States)

    Kuech, Robert; Zogg, Gregory; Zeeman, Stephan; Johnson, Mark

    This paper describes a study conducted on the lab sections of the general biology course for non-science majors at the University of New England, and reports findings of student misconceptions about photosynthesis and the mass/carbon uptake during plant growth. The current study placed high technology analytic tools in the hands of introductory…

  18. Effects of 17beta-trenbolone in male eelpout Zoarces viviparus exposed to ethinylestradiol.

    Science.gov (United States)

    Velasco-Santamaría, Yohana M; Madsen, Steffen S; Bjerregaard, Poul; Korsgaard, Bodil

    2010-01-01

    To evaluate the interaction between 17beta-trenbolone (TB) and 17alpha-ethinylestradiol (EE2), male eelpout, Zoarces viviparus, was exposed for 21 days (April to May 2008) to 5 ng l(-1) EE2 and 5 or 20 ng l(-1) TB, separately or in combination in a flow-through SW system. The effects on hepatosomatic (HSI) and gonadosomatic index (GSI), plasma vitellogenin (Vtg) concentration, gonadal histology, hepatic and testicular Vtg mRNA and estrogen receptor (ERalpha) mRNA expression were investigated. No effects on HSI were observed. A significant decrease was observed in the GSI of all males exposed to EE2 (300-fold), hepatic Vtg mRNA (>450-fold), and ERalpha mRNA (>100-fold) when compared to controls. This study shows that lower concentrations of 17beta-trenbolone are unable to counteract the EE2 estrogenic effects when the exposure is simultaneous.

  19. The Effect of Adjuvants on Penetration of beta-cypermethrin Through the Epidermis of Cabbage Leaf

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; ZHANG Li-ta; ZHENG Fei-neng; CHEN Fu-liang; LIANG Wen-ping

    2002-01-01

    The effects of three types of adjuvant (mineral oil, higher aliphatic acid and nonionic surfactant) on the penetration of beta-cypermethrin through the cabbage leaf surface were studied. The results showed that the penetration was positively correlated with both the concentration of adjuvant and the time after application, in a given range of treatment. A synergistic effect of two types of adjuvant on the penetration was found. Some physical properties of emulsions were determined. The change of the structures of the cabbage leaf surface by these adjuvants was observed from photomicrographs. The mechanism concerned with the effect of these adjuvants on the penetration of beta-cypermethrin through the cabbage leaf surface was tentatively discussed.

  20. Dual aminergic regulation of central beta adrenoceptors. Effect of atypical antidepressants and 5-hydroxytryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Manier, D.H.; Gillespie, D.D.; Sulser, F.

    1989-06-01

    Nonlinear regression analysis of agonist competition binding curves reveals that the (/sup 3/H)-dihydroalprenolol-labeled receptor population with low affinity for isoproterenol is increased by p-chlorophenylalanine (PCPA) and this increase is abolished by 5-hydroxytryptophan (5-HTP) in vivo. Desipramine (DMI) decreased the beta adrenoceptor population with high agonist affinity to the same degree in PCPA-treated animals as in control animals, thus explaining the reported discrepancy between beta adrenoceptor number and responsiveness of the beta adrenoceptor-coupled adenylate cyclase system. Mianserin also selectively reduced the beta adrenoceptor population with high agonist affinity in membrane preparations of normal animals, whereas fluoxetine selectively abolished the upregulation of the low affinity sites in reserpinized animals and had no effect on either receptor population from brain of normal animals. The results emphasize the importance of nonlinear regression analysis of agonist competition binding for the interpretation of drug action and encourage the pursuit of the molecular neurobiology of the serotonin (5-HT)/norepinephrine (NE) link in brain.

  1. Effectiveness of interferon-beta and temozolomide combination therapy against temozolomide-refractory recurrent anaplastic astrocytoma

    Directory of Open Access Journals (Sweden)

    Arai Hajime

    2007-08-01

    Full Text Available Abstract Background Malignant gliomas recur even after extensive surgery and chemo-radiotherapy. Although a relatively novel chemotherapeutic agent, temozolomide (TMZ, has demonstrated promising activity against recurrent glioma, the effects last only a few months and drug resistance develops thereafter in most cases. Induction of O6-methylguanine-DNA methyltransferase (MGMT in tumors is considered to be responsible for resistance to TMZ. Interferon-beta has been reported to suppress MGMT in an experimental glioma model. Here we report a patient with TMZ-refractory anaplastic astrocytoma (AA who was treated successfully with a combination of interferon-beta and TMZ. Case presentation A patient with recurrent AA after radiation-chemotherapy and stereotactic radiotherapy was treated with TMZ. After 6 cycles, the tumor became refractory to TMZ, and the patient was treated with interferon-beta at 3 × 106 international units/body, followed by 5 consecutive days of 200 mg/m2 TMZ in cycles of 28 days. After the second cycle the tumor decreased in size by 50% (PR. The tumor showed further shrinkage after 8 months and the patient's KPS improved from 70% to 100%. The immunohistochemical study of the initial tumor specimen confirmed positive MGMT protein expression. Conclusion It is considered that interferon-beta pre-administration increased the TMZ sensitivity of the glioma, which had been refractory to TMZ monotherapy.

  2. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-beta signaling during mammary tumorigenesis.

    Science.gov (United States)

    Tian, Maozhen; Schiemann, William P

    2010-04-01

    The molecular mechanisms that enable cyclooxygenase-2 (COX-2) and its mediator prostaglandin E2 (PGE2) to inhibit transforming growth factor-beta (TGF-beta) signaling during mammary tumorigenesis remain unknown. We show here that TGF-beta selectively stimulated the expression of the PGE2 receptor EP2, which increased normal and malignant mammary epithelial cell (MEC) invasion, anchorage-independent growth, and resistance to TGF-beta-induced cytostasis. Mechanistically, elevated EP2 expression in normal MECs inhibited the coupling of TGF-beta to Smad2/3 activation and plasminogen activator inhibitor-1 (PAI1) expression, while EP2 deficiency in these same MECs augmented Smad2/3 activation and PAI expression stimulated by TGF-beta. Along these lines, engineering malignant MECs to lack EP2 expression prevented their growth in soft agar, restored their cytostatic response to TGF-beta, decreased their invasiveness in response to TGF-beta, and potentiated their activation of Smad2/3 and expression of PAI stimulated by TGF-beta. More important, we show that COX-2 or EP2 deficiency both significantly decreased the growth, angiogenesis, and pulmonary metastasis of mammary tumors produced in mice. Collectively, this investigation establishes EP2 as a potent mediator of the anti-TGF-beta activities elicited by COX-2/PGE2 in normal and malignant MECs. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the oncogenic activities of TGF-beta during mammary tumorigenesis.-Tian, M., Schiemann, W. P. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-beta signaling during mammary tumorigenesis.

  3. Effect of Conversion Efficiency on Gamma-Ray Burst Energy

    Institute of Scientific and Technical Information of China (English)

    Lei Xu; Zi-Gao Dai

    2004-01-01

    Beaming effect makes it possible that gamma-ray bursts have a standard energy,but the gamma-ray energy release is sensitive to some parameters.Our attention is focused on the effect of the gamma ray conversion efficiency(ηγ),which may range between 0.01 and 0.9,and which probably has a random value for different GRBs under certain conditions.Making use of the afterglow data from the literature,we carried out a complete correction to the conical opening angle formula.Within the framework of the conical jet model,we ran a simple Monte Carlo simulation for random values of ηγ,and found that the gamma-ray energy release is narrowly clustered,whether we use a constant value of ηγ or random values for different gamma-ray bursts.

  4. Specimen preparation for cryogenic coherent X-ray diffraction imaging of biological cells and cellular organelles by using the X-ray free-electron laser at SACLA.

    Science.gov (United States)

    Kobayashi, Amane; Sekiguchi, Yuki; Oroguchi, Tomotaka; Okajima, Koji; Fukuda, Asahi; Oide, Mao; Yamamoto, Masaki; Nakasako, Masayoshi

    2016-07-01

    Coherent X-ray diffraction imaging (CXDI) allows internal structures of biological cells and cellular organelles to be analyzed. CXDI experiments have been conducted at 66 K for frozen-hydrated biological specimens at the SPring-8 Angstrom Compact Free-Electron Laser facility (SACLA). In these cryogenic CXDI experiments using X-ray free-electron laser (XFEL) pulses, specimen particles dispersed on thin membranes of specimen disks are transferred into the vacuum chamber of a diffraction apparatus. Because focused single XFEL pulses destroy specimen particles at the atomic level, diffraction patterns are collected through raster scanning the specimen disks to provide fresh specimen particles in the irradiation area. The efficiency of diffraction data collection in cryogenic experiments depends on the quality of the prepared specimens. Here, detailed procedures for preparing frozen-hydrated biological specimens, particularly thin membranes and devices developed in our laboratory, are reported. In addition, the quality of the frozen-hydrated specimens are evaluated by analyzing the characteristics of the collected diffraction patterns. Based on the experimental results, the internal structures of the frozen-hydrated specimens and the future development for efficient diffraction data collection are discussed.

  5. Biological effectiveness of neutron irradiation on animals and man

    Energy Technology Data Exchange (ETDEWEB)

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, /sup 252/Cf-fission, and 15 MeV neutrons, compared with that by /sup 60/Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use.

  6. X-ray diffraction radiation in conditions of Cherenkov effect

    NARCIS (Netherlands)

    Tishchenko, A. A.; Potylitsyn, A. P.; Strikhanov, M. N.

    2006-01-01

    X-ray diffraction radiation from ultra-relativistic electrons moving near an absorbing target is considered. The emission yield is found to increase significantly in conditions of Cherenkov effect. (c) 2006 Elsevier B.V. All rights reserved.

  7. Contribution of alpha4beta1 integrin to the antiallergic effect of levocabastine.

    Science.gov (United States)

    Qasem, Ahmed R; Bucolo, Claudio; Baiula, Monica; Spartà, Antonino; Govoni, Paolo; Bedini, Andrea; Fascì, Domenico; Spampinato, Santi

    2008-09-15

    Levocabastine is an antiallergic drug acting as a histamine H1-receptor antagonist. In allergic conjunctivitis (AC), it may also antagonize up-regulation of the intercellular adhesion molecule-1 (ICAM-1) expressed on epithelial conjunctival cells. However, little is known about its effects on eosinophils, important effector cells in AC. The adhesion molecule integrin alpha(4)beta(1) is expressed in eosinophils; it interacts with the vascular cell adhesion molecule-1 (VCAM-1) and fibronectin (FN) in vascular endothelial cells and contributes to eosinophil activation and infiltration in AC. This study provides evidence that in a scintillation proximity assay levocabastine (IC(50) 406 microM), but not the first-generation antihistamine chlorpheniramine, displaced (125)I-FN binding to human integrin alpha(4)beta(1) and, in flow cytometry analysis, levocabastine antagonized the binding of a primary antibody to integrin alpha(4) expressed on the Jurkat cell surface. Levocabastine, but not chlorpheniramine, binds the alpha(4)beta(1) integrin and prevents eosinophil adhesion to VCAM-1, FN or human umbilical vascular endothelial cells (HUVEC) in vitro. Similarly, levocabastine affects alpha(L)beta(2)/ICAM-1-mediated adhesion of Jurkat cells. In a model of AC levocabastine eye drops reduced the clinical aspects of the late-phase reaction and the conjunctival expression of alpha(4)beta(1) integrin by reducing infiltrated eosinophils. We propose that blockade of integrin-mediated cell adhesion might be a target of the antiallergic action of levocabastine and may play a role in preventing eosinophil adhesion and infiltration in AC.

  8. Landau level-superfluid modified factor and effective X/$\\gamma$-ray coefficient of a magnetar

    CERN Document Server

    Gao, Z F; Wang, N; Chou, C K; Huo, W S

    2013-01-01

    As soon as the energy of electrons near the Fermi surface are higher than $Q$, the threshold energy of inverse $\\beta-$ decay, the electron capture process will dominate. The resulting high-energy neutrons will destroy anisotropic ${}^3P_2$ neutron superfluid Cooper pairs. By colliding with the neutrons produced in the process $n+ (n\\uparrow n\\downarrow)\\longrightarrow n+ n+ n$, the kinetic energy of the outgoing neutrons will be transformed into thermal energy. The transformed thermal energy would transported from the star interior to the star surface by conduction, then would be transformed into radiation energy as soft X-rays and gamma-rays. After a highly efficient modulation within the pulsar magnetosphere, the surface thermal emission (mainly soft X/$\\gamma$-ray emission) has been shaped into a spectrum with the observed characteristics of magnetars. By introducing two important parameters: Landau level-superfluid modified factor and effective X/$\\gamma$-ray coefficient, we numerically simulate the proc...

  9. Overexpression of estrogen receptor beta alleviates the toxic effects of beta-amyloid protein on PC12 cells via non-hormonal ligands

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Lihui Si; Xiaoxi Li; Weiguo Deng; Haimiao Yang; Yuyan Yang; Yan Fu

    2012-01-01

    After binding to the estrogen receptor, estrogen can alleviate the toxic effects of beta-amyloid protein, and thereby exert a therapeutic effect on Alzheimer's disease patients. Estrogen can increase the incidence of breast carcinoma and endometrial cancer in post-menopausal women, so it is not suitable for clinical treatment of Alzheimer's disease. There is recent evidence that the estrogen receptor can exert its neuroprotective effects without estrogen dependence. Real-time quantitative PCR and flow cytometry results showed that, compared with non-transfected PC12 cells, adenovirus-mediated estrogen receptor β gene-transfected PC12 cells exhibited lower expression of tumor necrosis factor α and interleukin 1β under stimulation with beta-amyloid protein and stronger protection from apoptosis. The Akt-specific inhibitor Abi-2 decreased the anti-inflammatory and anti-apoptotic effects of estrogen receptor β gene-transfection. These findings suggest that overexpression of estrogen receptor β can alleviate the toxic effect of beta-amyloid protein on PC12 cells, without estrogen dependence. The Akt pathway is one of the potential means for the anti-inflammatory and anti-apoptotic effects of the estrogen receptor.

  10. Relative biological effectiveness for photons: implication of complex DNA double-strand breaks as critical lesions

    Science.gov (United States)

    Liang, Ying; Fu, Qibin; Wang, Xudong; Liu, Feng; Yang, Gen; Luo, Chunxiong; Ouyang, Qi; Wang, Yugang

    2017-03-01

    Current knowledge in radiobiology ascribes the adverse biological effects of ionizing radiation primarily to the induction of DNA double-strand breaks (DSBs), which is supposed to be potentially lethal and may be converted to lethal damage due to misrepair. Soft and ultrasoft x-rays have been found to bear elevated biological effectiveness for cell killing compared with conventional x-rays or 60Co γ-rays. This phenomenon is qualitatively interpreted as the increased level of DSB induction for low energy photons, however, a thorough quantitative reasoning is lacking. Here, we systematically compared the relative biological effectiveness (RBE) with relative DSB induction for photons from several hundreds of eV up to MeV. Although there is an approximate two-fold increase in the yields of DSB for low energy photons found in our calculation and a large number of experimental measurements, it is far from enough to account for the three- to four-fold increase in RBE. Further theoretical investigations show that DSB complexity (additional single-strand breaks and base damage within 10 base pairs) increases notably for low energy photons, which largely reconciles the discrepancy between RBE and DSB induction. Our theoretical results are in line with accumulating experimental evidence that complex DSBs are refractory to repair machinery and may contribute predominantly to the formation of lethal damage.

  11. Radiation chemical effects of X-rays on liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holroyd, R.A.; Preses, J.M.

    1998-11-01

    This review describes some of the chemical changes induced by photoelectrons which are released in liquids when X-rays are absorbed. Both experimental studies and theory are discussed. In part 1, the basic processes occurring upon absorption of X-rays are described. Parts 2 and 3 deal with hydrocarbon liquids; in part 2 the ion yields, including effects at K-edges, and in part 3, the yields of excited states. Part 4 discusses chemical effects of X-rays in aqueous solutions. The authors end with a summary of future needs and directions.

  12. Historical agriculture alters the effects of fire on understory plant beta diversity.

    Science.gov (United States)

    Mattingly, W Brett; Orrock, John L; Collins, Cathy D; Brudvig, Lars A; Damschen, Ellen I; Veldman, Joseph W; Walker, Joan L

    2015-02-01

    Land-use legacies are known to shape the diversity and distribution of plant communities, but we lack an understanding of whether historical land use influences community responses to contemporary disturbances. Because human-modified landscapes often bear a history of multiple land-use activities, this contingency can challenge our understanding of land-use impacts on plant diversity. We address this contingency by evaluating how beta diversity (the spatial variability of species composition), an important component of regional biodiversity, is shaped by interactions between historical agriculture and prescribed fire, two prominent disturbances that are often coincident in terrestrial ecosystems. At three study locations spanning 450 km in the southeastern United States, we surveyed longleaf pine woodland understory plant communities across 232 remnant and post-agricultural sites with differing prescribed fire regimes. Our results demonstrate that agricultural legacies are a strong predictor of beta diversity, but the direction of this land-use effect differed among the three study locations. Further, although beta diversity increased with prescribed fire frequency at each study location, this effect was influenced by agricultural land-use history, such that positive fire effects were only documented among sites that lacked a history of agriculture at two of our three study locations. Our study not only highlights the role of historical agriculture in shaping beta diversity in a fire-maintained ecosystem but also illustrates how this effect can be contingent upon fire regime and geographic location. We suggest that interactions among historical and contemporary land-use activities may help to explain dissimilarities in plant communities among sites in human-dominated landscapes.

  13. Increased glucocorticoid sensitivity in pancreatic beta-cells : Effects on glucose metabolism and insulin release

    OpenAIRE

    Davani, Behrous

    2003-01-01

    Type 2 diabetes mellitus (T2DM) is characterized by three pathological alterations: (1) insulin resistance in peripheral tissues, (2) increased hepatic glucose production and (3) impaired insulin secretion from the pancreatic beta-cells. Glucocorticoids (GCs) exert profound effects on glucose homeostasis. They decrease glucose uptake and increase hepatic glucose production. In addition, they may directly inhibit insulin release. The main aim of this thesis was to investigate...

  14. Effects of. beta. -cyclodextrin on the luminescence of para amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, J.H.; Walker, R.G. (Royal Military Coll. of Science, Shrivenham (UK))

    1981-05-11

    Beta-cyclodextrin has been added to para amino benzoic acid (PABA) and luminescence changes observed for the PABA anion. The intensity of fluorescence was increased upon complexation of the PABA at 298 K due to the prevention of collisional deactivation of the PABA, but at 77 K the fluorescence was reduced due to the increase of vibrational deactivation modes available to the complex relative to the free PABA. The luminescence effects were interpreted as inclusion complexation of the PABA anion.

  15. The effective exponent gamma(Q) and the slope of the beta function

    CERN Document Server

    Stevenson, P M

    2016-01-01

    The slope of the beta function at a fixed point is commonly thought to be RG invariant and to be the critical exponent gamma* that governs the approach of any physical quantity R to its fixed-point limit: R*-R proportional to Q^gamma*. Chyla has shown that this is not quite true. Here we define a proper RG invariant, the "effective exponent" gamma(Q), whose fixed-point limit is the true gamma*.

  16. Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

    Science.gov (United States)

    Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

    2015-01-01

    In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

  17. Effect of beta-adrenergic stimulants on cytotoxicity of mitomycin C in HeLa cells.

    Science.gov (United States)

    Miyamoto, K; Sanae, F; Iwasaki, M; Koshiura, R

    1982-12-01

    Effects of several autonomic agents on the cytotoxicity of mitomycin C in HeLa cells were studied. When beta-adrenergic stimulants such as isoproterenol, epinephrine, terbutaline and turobuterol were added at concentrations over 10(-14) M 15 to 60 min before mitomycin C, the colony-forming ability of HeLa cells was significantly inhibited more than by mitomycin C alone. The action of isoproterenol and epinephrine on the colony-forming ability of the cells was abolished by propranolol. The intracellular cyclic AMP level of HeLa cells reached the peak of about two-fold the basal level at 30 min after the addition of 10(-8) M isoproterenol. In combination with mitomycin C, the high level of intracellular cyclic AMP induced by isoproterenol was maintained for a significantly longer period in comparison with that by isoproterenol alone, while mitomycin C alone caused essentially no change in the cyclic AMP level. The pretreatment with dibutyryl cyclic AMP also enhanced the effect of mitomycin C. From these findings, it is strongly suggested that the synergistic effect of beta-adrenergic stimulants on the cytotoxicity of mitomycin C is mediated via stimulation of the beta-adrenoceptors of HeLa cells which elevates the intracellular cyclic AMP for a long time in combination with mitomycin C.

  18. Effect of pathogenic mutations on the structure and dynamics of Alzheimer's A beta 42-amyloid oligomers.

    Science.gov (United States)

    Kassler, Kristin; Horn, Anselm H C; Sticht, Heinrich

    2010-05-01

    Converging lines of evidence suggest that soluble A beta-amyloid oligomers play a pivotal role in the pathogenesis of Alzheimer's disease, and present direct effectors of synaptic and cognitive dysfunction. Three pathological E22-A beta-amyloid point mutants (E22G, E22K, E22Q) and the deletion mutant E22 Delta exhibit an enhanced tendency to form prefibrillar aggregates. The present study assessed the effect of these four mutations using molecular dynamics simulations and subsequent structural and energetic analyses. Our data shows that E22 plays a unique role in wild type A beta, since it has a destabilising effect on the oligomer structure due to electrostatic repulsion between adjacent E22 side chains. Mutations in which E22 is replaced by an uncharged residue result in higher oligomer stability. This effect is also observed to a lesser extent for the E22K mutation and is consistent with its lower pathogenicity compared to other mutants. Interestingly, deletion of E22 does not destroy the amyloid fold but is compensated by local changes in the backbone geometry that allow the preservation of a structurally important salt bridge. The finding that all mutant oligomers investigated exhibit higher internal stability than the wild type offers an explanation for the experimentally observed enhanced oligomer formation and stability.

  19. Gamma rays and bleomycin nick DNA and reverse the DNase I sensitivity of beta-globin gene chromatin in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Villeponteau, B.; Martinson, H.G.

    1987-05-01

    The active beta-globin genes in chicken erythrocytes, like all active genes, reside in large chromatin domains which are preferentially sensitive to digestion by DNase I. We have recently proposed that the special structure of chromatin in active domains is maintained by torsional stress in the DNA. This hypothesis predicts that nicking of the DNA within any such chromosomal domain in vivo will relax the DNA and lead to loss of the special DNase I-sensitive state. Here we have tested this prediction by using gamma irradiation and bleomycin treatment to cleave DNA within intact chicken embryo erythrocytes. Both treatments cause reversal of DNase I sensitivity. Moreover, reversal occurs at approximately one nick per 150 kilobase pairs for both agents despite their entirely unrelated modes of cell penetration and DNA attack. These results suggest that the domain of DNase I sensitivity surrounding the beta-globin genes comprises 150 kilobase pairs of chromatin under torsional stress and that a single DNA nick in this region is sufficient to reverse the DNase I sensitivity throughout the entire domain.

  20. Beta射线技术在颗粒物中的应用研究%Study on the Application of Beta-ray Technology in Particulate Matter

    Institute of Scientific and Technical Information of China (English)

    于哲; 农永光; 郭炜; 赵文峰; 胡刚

    2014-01-01

    This paper analyzes the Beta-ray technology and obtains a technology which can be used for technical ambient air PM2.5 continuous monitoring. This technology is tested under different conditions, and the applicability and technical limitations of this technology is known through the data obtained.%本文通过对于Beta射线技术的分析得到一种可以用于环境空气颗粒物PM2.5连续监测过程的技术,并对该技术在不同条件下进行测试,通过所得到的数据得出该技术的适用性和技术局限性。

  1. Sulfur K{beta} x-ray emission from carbonyl sulfide: Variations with polarization and excitation energy at the S K threshold

    Energy Technology Data Exchange (ETDEWEB)

    Miyano, K.E. [Department of Physics, Brooklyn College, Brooklyn, New York 11210 (United States); Arp, U. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Southworth, S.H. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Meehan, T.E.; Walsh, T.R.; Larkins, F.P. [School of Chemistry, The University of Melbourne, Parkville, (Australia) 3052

    1998-04-01

    Sulfur K{beta} x-ray-emission spectra from carbonyl sulfide have been measured with resonant excitation at the sulfur K absorption threshold and compared with results of self-consistent field and singles-doubles configuration-interaction calculations. For excitation to the strong 4{pi} absorption resonance, a splitting of the main emission peak is interpreted in terms of influence of the 4{pi} electron on the final valence-hole states. The polarization selectivity of the emission spectrometer was used to distinguish emission polarized parallel versus perpendicular with respect to the polarization of the excitation radiation. The observed polarization dependence is consistent with the molecular symmetries of the calculated intermediate and final states. {copyright} {ital 1998} {ital The American Physical Society}

  2. Rapid effects of phytoestrogens on human colonic smooth muscle are mediated by oestrogen receptor beta.

    LENUS (Irish Health Repository)

    Hogan, A M

    2012-02-01

    Epidemiological studies have correlated consumption of dietary phytoestrogens with beneficial effects on colon, breast and prostate cancers. Genomic and non-genomic mechanisms are responsible for anti-carcinogenic effects but, until now, the effect on human colon was assumed to be passive and remote. No direct effect on human colonic smooth muscle has previously been described. Institutional research board approval was granted. Histologically normal colon was obtained from the proximal resection margin of colorectal carcinoma specimens. Circular smooth muscle strips were microdissected and suspended under 1g of tension in organ baths containing oxygenated Krebs solution at 37 degrees C. After an equilibration period, tissues were exposed to diarylpropionitrile (DPN) (ER beta agonist) and 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) (ER alpha agonist) or to the synthetic phytoestrogen compounds genistein (n=8), daidzein (n=8), fisetin (n=8) and quercetin (n=8) in the presence or absence of fulvestrant (oestrogen receptor antagonist). Mechanism of action was investigated by inhibition of downstream pathways. The cholinergic agonist carbachol was used to induce contractile activity. Tension was recorded isometrically. Phytoestrogens inhibit carbachol-induced colonic contractility. In keeping with a non-genomic, rapid onset direct action, the effect was within minutes, reversible and similar to previously described actions of 17 beta oestradiol. No effect was seen in the presence of fulvestrant indicating receptor modulation. While the DPN exerted inhibitory effects, PPT did not. The effect appears to be reliant on a p38\\/mitogen activated protein kinase mediated induction of nitric oxide production in colonic smooth muscle. The present data set provides the first description of a direct effect of genistein, daidzein, fisetin and quercetin on human colonic smooth muscle. The presence of ER in colonic smooth muscle has been functionally proven and the beta

  3. Non-Thermal Effects Mobile Phones at Biological Objects

    OpenAIRE

    Ladislav Balogh

    2003-01-01

    The article deals with non-thermal effects of mobile phones on biological objects. Even though these effects are observed for longer period, there are not so far unequivocal results on obtained biological and biophysical results in this field. Biologicaleffects of electromagnetic field (EMF) depend on its character, its duration as well as on features of organism. As the receptors offield are not known (e.g. inputs of EMF into organism), its effects are judged only by non-specific reaction of...

  4. Feasibility of photoelectron sources for testing the energy scale stablity of the KATRIN beta-ray spectrometer

    CERN Document Server

    Dragoun, O; Kaspar, J; Bonn, J; Kovalik, A; Otten, E W; Venos, D; Weinheimer, Ch

    2010-01-01

    Photoabsorption of nuclear gamma-rays in thin metallic convertors was examined with the aim to produce monoenergetic photoelectrons of kinetic energy around 18.6 keV and natural width of about 1 eV. Calculations were carried out for commercial photon sources of 241Am (1.1 GBq) and 119mSn (0.5 GBq) irradiating Co and Ti convertors. Photoelectrons ejected by 241Am gamma- and X-rays from Co convertors of various thickness were measured with two electrostatic spectrometers.

  5. Resistive MHD studies of high-beta tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, V.E.; Hicks, H.R.; Holmes, J.A.; Carreras, B.A.; Garcia, L.

    1982-02-01

    Numerical calculations have been performed to study the magnetohydrodynamic (MHD) activity in high-beta tokamaks such as ISX-B. These initial value calculations have been built on earlier low-beta techniques, but the beta effects create several new numerical issues. These issues are discussed and resolved. In addition to time-stepping modules, our system of computer codes includes equilibrium solvers (used to provide an initial condition) and output modules, such as a magnetic field line follower and an x-ray diagnostic code. The transition from current-driven modes at low beta to predominantly pressure-driven modes at high beta is described. The nonlinear studies yield x-ray emissivity plots which are compared with experiment.

  6. Resistive MHD studies of high-. beta. -tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, V.E.; Carreras, B.A.; Hicks, H.R.; Holmes, J.A.; Garcia, L.

    1981-01-01

    Numerical calculations have been performed to study the MHD activity in high-..beta.. tokamaks such as ISX-B. These initial value calculations built on earlier low ..beta.. techniques, but the ..beta.. effects create several new numerical issues. These issues are discussed and resolved. In addition to time-stepping modules, our system of computer codes includes equilibrium solvers (used to provide an initial condition) and output modules, such as a magnetic field line follower and an X-ray diagnostic code. The transition from current driven modes at low ..beta.. to predominantly pressure driven modes at high ..beta.. is described. The nonlinear studies yield X-ray emissivity plots which are compared with experiment.

  7. Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging

    Science.gov (United States)

    Serpell, Christopher J.; Rutte, Reida N.; Geraki, Kalotina; Pach, Elzbieta; Martincic, Markus; Kierkowicz, Magdalena; de Munari, Sonia; Wals, Kim; Raj, Ritu; Ballesteros, Belén; Tobias, Gerard; Anthony, Daniel C.; Davis, Benjamin G.

    2016-10-01

    The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular `blueprint' this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as `contrast agents' if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging.

  8. Integral validation of the effective beta parameter for the MOX reactors and incinerators; Validation integrale des estimations du parametre beta effectif pour les reacteurs Mox et incinerateurs

    Energy Technology Data Exchange (ETDEWEB)

    Zammit-Averlant, V

    1998-11-19

    {beta}{sub eff}, which represents the effective delayed neutron fraction, is an important parameter for the reactor nominal working as well as for studies of its behaviour in accidental situation. In order to improve the safety of nuclear reactors, we propose here to validate its calculation by using the ERANOS code with ERALIB1 library and by taking into account all the fission process physics through the {nu} energy dependence. To validate the quality of this calculation formalism, we calculated uncertainties as precisely as possible. The experimental values of {beta}{sub eff}, as well their uncertainties, have also been re-evaluated for consistency, because these `experimental` values actually contain a calculated component. We therefore obtained an entirely coherent set of calculated and measured {beta}{sub eff}. The comparative study of the calculated and measured values pointed out that the JEF2.2 {nu}{sub d} are already sufficient because the (E-C)/C are inferior to 3 % in average and in their uncertainly bars. The experimental uncertainties, even if lightly superior to those previously edited, remain inferior to the uncertainties of the calculated values. This allowed us to fit {nu}{sub d} with {beta}{sub eff}. This adjustment has brought an additional improvement on the recommendations of the {nu}{sub d} average values, for the classical scheme (thermal energy, fast energy) and for the new scheme which explains the {nu}{sub d} energy dependence. {beta}{sub eff}, for MOX or UOX fuel assemblies in thermal or fast configurations, can therefore be obtained with an uncertainty due to the nuclear data of about 2.0 %. (author) 110 refs.

  9. Production and action of transforming growth factor-beta in human osteoblast cultures: dependence on cell differentiation and modulation by calcitriol

    DEFF Research Database (Denmark)

    Kassem, M; Kveiborg, Marie; Eriksen, E F

    2000-01-01

    Transforming growth factor beta (TGF-beta) plays an important role in skeletal remodelling. However, few studies have examined its effects on cultured human osteoblasts. Our aim is to characterise the biological effects of TGF-beta1 on human osteoblasts and to examine the interaction between TGF-...

  10. Effects of meal size and composition on incretin, alpha-cell, and beta-cell responses

    DEFF Research Database (Denmark)

    Rijkelijkhuizen, Josina M; McQuarrie, Kelly; Girman, Cynthia J

    2009-01-01

    of beta-cell function and incremental areas under the curve of glucose, insulin, C-peptide, glucagon, GLP-1, and GIP were calculated. Mixed models and Friedman tests were used to test for differences in meal responses. The large CH-rich meal and fat-rich meal resulted in a slightly larger insulin response......The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) regulate postprandial insulin release from the beta-cells. We investigated the effects of 3 standardized meals with different caloric and nutritional content in terms of postprandial glucose......, insulin, glucagon, and incretin responses. In a randomized crossover study, 18 subjects with type 2 diabetes mellitus and 6 healthy volunteers underwent three 4-hour meal tolerance tests (small carbohydrate [CH]-rich meal, large CH-rich meal, and fat-rich meal). Non-model-based and model-based estimates...

  11. Configurational Variations and Finite-Beta Effects on Neoclassical Viscosities and Flows in Stellarators

    Science.gov (United States)

    Breyfogle, M.; Marine, T.; Ware, A. S.; Spong, D. A.

    2008-11-01

    The impact of magnetic geometry on neoclassical flows and viscosities for the Helically Symmetric Experiment (HSX) is investigated using the PENTA code [1,2]. Specifically, two topics are investigated: (1) finite-beta effects and (2) configurational variations. The PENTA code is used to calculate flows in HSX with the vacuum magnetic geometry and with finite-beta magnetic surfaces from the VMEC equilibrium code. This is done for the standard quasi-helically symmetric configuration of HSX, a symmetry-breaking mirror configuration and a hill configuration. The impact of these changes in the magnetic geometry on neoclassical viscosities and flows in HSX will be discussed.[0pt] [1] D. A. Spong, Phys. Plasmas 12, 056114 (2005). [0pt] [2] D. A. Spong, Fusion Sci. Technology 50, 343 (2006).

  12. Effects of putrescine, cadaverine, spermine, spermidine and beta-phenylethylamine on cultured bovine mammary epithelial cells

    DEFF Research Database (Denmark)

    Fusi, Eleonora; Baldi, Antonella; Cheli, Federica;

    2008-01-01

    A bovine mammary epithelial cell line (BME-UV1) and three-dimensional collagen primary bovine organoids were used to evaluate the effects of cadaverine, putrescine, spermine, spermicline and beta-phenylethylamine on mammary epithelial cells. Each biogenic amine was diluted in several concentrations...... (0-50 mM in BME-UV1 and 0-4 mM in primary bovine organoids) in the appropriate saline solution for the cell culture considered. In order to determine the activity of each compound tritiated thymidine incorporation was used. At low concentrations, all amines induced cell proliferation in both cultures....... In BME-UV1, spermine significantly inhibited cell proliferation (Pamines inhibited at higher concentrations (50mM). In primary bovine organoids, beta-phenylethylamine significantly (Pamines...

  13. The effect of interferon-beta on black holes in patients with multiple sclerosis.

    Science.gov (United States)

    Bagnato, Francesca; Evangelou, Iordanis E; Gallo, Antonio; Gaindh, Deeya; Yao, Karen

    2007-07-01

    Multiple sclerosis (MS) is an immunological disorder of the CNS. Linked to an initial transient inflammation as the result of blood-brain barrier leakage, the disease progresses into a neurodegenerative phase. MRI is the most powerful paraclinical tool for diagnosing and monitoring MS. Although contrast enhancing lesions are the visible events of blood-brain barrier breakdown, accumulation of hypointense lesions, namely black holes, are recognised as irreversible axonal loss. IFN-beta is administered as a first-line drug in MS patients. However, whether the effect of IFN-beta extends beyond just prevention of blood-brain barrier leakage and further prevents the formation of black holes or promotes their recovery once formed, is not yet understood.

  14. The effect of beta blockade on stress-induced cognitive dysfunction in adolescents.

    Science.gov (United States)

    Faigel, H C

    1991-07-01

    Test anxiety is severely disabling to students whose fear of examinations causes cognitive dysfunction that paralyzes their thinking the way stage fright impairs actors ability to act. In studies using subjective evaluations among actors and musicians, beta-blockade relieved stage fright and has been used informally to treat test anxiety in students without objective measures of effectiveness. The Scholastic Aptitude Test (SAT) was chosen as an objective test instrument to confirm the effect of beta-blockade on test anxiety and performance. Thirty-two high school students who had already taken the SAT before enrolling in this study and who had stress-induced cognitive dysfunction on exams were given 40 mg of propranolol one hour before they retook those tests. Mean SAT scores with beta-blockade were 130 points higher than on the initial SAT done before entering the study without medication (p = less than .01). A single dose of propranolol immediately before the SAT permitted improved performance in students prone to cognitive dysfunction due to test anxiety.

  15. In situ microfluidic dialysis for biological small-angle X-ray scattering

    DEFF Research Database (Denmark)

    Skou, Magda; Skou, Soren; Jensen, Thomas Glasdam;

    2014-01-01

    Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented for sim...

  16. Experimental Study on Soft X-ray Contact Microscopy for Biological Specimens

    Institute of Scientific and Technical Information of China (English)

    XIE Honglan; GAO Hongyi; JIANG Shiping; CHEN Jianwen; LU Peixiang; XU Zhizhan

    2002-01-01

    Using Hefei Synchrotron radiation as X-ray source and photoresist PMMA as recording medium, soft X-ray contact microscopic imaging experiment on hydrated leaf epidermal cells of a kind of dicotyledon is performed and its latent image is read out by a light microscope. Several main factors degrading the resolution of the image are discussed in detail.

  17. Effect of biologic therapy on radiological progression in rheumatoid arthritis: what does it add to methotrexate?

    Directory of Open Access Journals (Sweden)

    Jones G

    2012-07-01

    Full Text Available Graeme Jones, Erica Darian-Smith, Michael Kwok, Tania WinzenbergMenzies Research Institute, University of Tasmania, Tasmania, AustraliaAbstract: There have been substantial advances in the treatment of rheumatoid arthritis in recent years. Traditional disease-modifying antirheumatic drugs (DMARDs have been shown to have small effects on the progression of radiographic damage. This quantitative overview summarizes the evidence for biologic DMARDS and radiographic damage either alone or in combination with methotrexate. Two outcomes were used (standardized mean difference and odds of progression. A total of 21 trials were identified of which 18 had useable data. For biologic monotherapy, tocilizumab, adalimumab, and etanercept were significantly better than methotrexate, with tocilizumab ranking first in both outcomes while golimumab was ineffective in both outcomes. For a biologic in combination with methotrexate compared with methotrexate alone, most therapies studied (etanercept, adalimumab, infliximab, certolizumab, tocilizumab, and rituximab were effective at slowing X-ray progression using either outcome, with infliximab ranking first in both outcomes. The exceptions to this were golimumab (no effect on standardized mean difference and abatacept (no effect on odds of progression. This effect was additional to methotrexate; thus, the overall benefit is moderate to large in magnitude, which is clearly of major clinical significance for sufferers of rheumatoid arthritis and supports the use of biologic DMARDs in those with a poor disease prognosis.Keywords: rheumatoid, trials, meta-analysis, radiographs, biologic, disease-modifying antirheumatic drugs, DMARDs

  18. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  19. Effect of {beta}{sub 1} adrenergic receptor blockade on myocardial blood flow and vasodilatory capacity

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher, M.; Czernin, J.; Sun, K. [Univ. of California, Los Angeles, CA (United States)] [and others

    1997-03-01

    The {beta}{sub 1} receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of {beta}{sub 1} receptor blockade on hyperemic MBF is unknown. To evaluate the effect of selective {beta}{sub 1} receptor blockade on MBF at rest and during dipyridamole induced hyperemia, 10 healthy volunteers (8 men, 2 women, mean age 24 {+-} 5 yr) were studied using {sup 13}N-ammonia PET (two-compartment model) under control conditions and again during metoprolol (50 mg orally 12 hr and 1 hr before the study). The resting rate pressure product (6628 {+-} 504 versus 5225 {+-} 807) and heart rate (63 {+-} 6-54 {plus_minus} 5 bpm) declined during metoprolol (p < 0.05). Similarly, heart rate and rate pressure product declined from the baseline dipyridamole study to dipyridamole plus metoprolol (p < 0.05). Resting MBF declined in proportion to cardiac work by approximately 20% from 0.61 {+-} 0.09-0.51 {+-} 0.10 ml/g/min (p < 0.05). In contrast, hyperemic MBF increased when metoprolol was added to dipyridamole (1.86 {plus_minus} 0.27 {+-} 0.45 ml/g/min; p<0.05). The decrease in resting MBF together with the increase in hyperemic MBF resulted in a significant increase in the myocardial flow reserve during metoprolol (3.14 {+-} 0.80-4.61 {+-} 0.68; p<0.01). The {beta}{sub 1} receptor blockade increases coronary vasodilatory capacity and myocardial flow reserve. However, the mechanisms accounting for this finding remain uncertain. 32 refs., 2 figs., 2 tabs.

  20. Effects of Vitamin E and Zinc Supplementation on Antioxidants in Beta-Thalassemia Major Patients

    Directory of Open Access Journals (Sweden)

    Abbasali Keshtkar

    2011-03-01

    Full Text Available Objective:In beta thalassemic patients, tissue damage occurs due to oxidative stress and it happens because of the accumulation of iron in the body. This study was conducted to determine the effect of zinc and vitamin E supplementation on antioxidant status in beta-thalassemic major patients. Methods:This double blind randomized clinical trial was carried out on 120 beta thalassemic patients older than 18 years. Patients were randomly categorized in four groups. Zinc (50mg/day and vitamin E (400mg/day supplements were administered for former and latter group, respectively. In the third group both supplements were administered in similar doses. The fourth (control group received no supplement. The effect of supplementations on serum zinc and vitamin E, superoxide dismutase (SOD, glutathione peroxidase (GPX, total antioxidant capacity (TAC and body mass index (BMI were measured at the beginning and the end of the study. Findings:Serum zinc levels in group 1 and 3 were significantly increased (P<0.007 and P<0.005, respectively. Serum vitamin E levels in group 2 and 3 were also increased significantly (P<0.001. Mean GPX activity in group1, 2 and 3 decreased significantly (P<0.015, P<0.032 and P<0.029, respectively. Mean SOD activity and TAC did not show significant change after supplementation. BMI had significant increase in all treated groups (P<0.001. Conclusion:Our results suggest that beta thalassemic patients have enhanced oxidative stress and administration of selective antioxidants may preclude oxidative damage.

  1. Effects of Vitamin E and Zinc Supplementation on Antioxidants in Beta thalassemia major Patients

    Science.gov (United States)

    Rashidi, Mohammadreza; Aboomardani, Maryam; Rafraf, Maryam; Arefhosseini, Seyed-Rafie; Keshtkar, Abbasali; Joshaghani, Hamidreza

    2011-01-01

    Objective In beta thalassemic patients, tissue damage occurs due to oxidative stress and it happens because of the accumulation of iron in the body. This study was conducted to determine the effect of zinc and vitamin E supplementation on antioxidant status in beta-thalassemic major patients. Methods This double blind randomized clinical trial was carried out on 120 beta thalassemic patients older than 18 years. Patients were randomly categorized in four groups. Zinc (50mg/day) and vitamin E (400mg/day) supplements were administered for former and latter group, respectively. In the third group both supplements were administered in similar doses. The fourth (control) group received no supplement. The effect of supplementations on serum zinc and vitamin E, superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (TAC) and body mass index (BMI) were measured at the beginning and the end of the study. Findings Serum zinc levels in group 1 and 3 were significantly increased (P<0.007 and P<0.005, respectively). Serum vitamin E levels in group 2 and 3 were also increased significantly (P<0.001). Mean GPX activity in group1, 2 and 3 decreased significantly (P<0.015, P<0.032 and P<0.029, respectively). Mean SOD activity and TAC did not show significant change after supplementation. BMI had significant increase in all treated groups (P<0.001). Conclusion Our results suggest that beta thalassemic patients have enhanced oxidative stress and administration of selective antioxidants may preclude oxidative damage. PMID:23056757

  2. Effect of natural {beta}-carotene supplementation in children exposed to radiation from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Amotz, A. [Israel Oceanographic and Limnological Research, Haifa (Israel); Yatziv, S. [Pediatric Department, Hadassah University Hospital, Jerusalem (Israel); Sela, M. [Maxillary-Facial Rehabilitation, Hadassah University Hospital, Jerusalem (Israel); Greenberg, S.; Rachmilevich, B.; Shwarzman, M.; Weshler, Z. [Sharett Institute of Oncology, Hadassah University Hospital, Jerusalem (Israel)

    1998-10-01

    Attempts were made to evaluate 709 children (324 boys and 385 girls) who had been exposed long-term to different doses of radiation during and after the Chernobyl accident and had moved to Israel between 1990 and 1994. Upon arrival, all of them underwent a check-up for most common clinical disorders and were then divided into three groups according to their residences (distance from the reactor) and the level of irradiation exposure: no radiation, <5 Ci/m{sup 2}, and >5 Ci/m{sup 2}, respectively. Blood serum analyses for total carotenoids, retinol, {alpha}-tocopherol and oxidized conjugated dienes in 262 of the children showed increased HPLC levels of conjugated dienes, indicating increased levels of oxidation of in vivo blood lipids in children from the contaminated areas. The levels were higher in girls than in boys. Some 57 boys and 42 girls were given a basal diet with a diurnal supplementation of 40 mg natural 9-cis and all-trans equal isomer mixture {beta}-carotene in a capsulated powder form of the alga Dunaliella bardawil, for a period of 3 months. Blood serum analyses were regularly conducted before supplementation to determine the baseline effect of radiation exposure to the children, after 1 and 3 months of natural {beta}-carotene supplementation. After supplementation, the levels of the oxidized conjugated dienes decreased in the children`s sera without any significant changes in the level of total carotenoids, retinol or {alpha}-tocopherol. Other common blood biochemicals were within the normal range for all tests and no statistical differences before or after supplementation of {beta}-carotene were noted. High pressure liquid chromatography (HPLC) analyses for carotenoids in the blood detected mainly oxycarotenoids, and to a lesser extent, all-trans {beta}-carotene, {alpha}-carotene, but not 9-cis {beta}-carotene. The results suggest that irradiation increases the susceptibility of lipids to oxidation in the Chernobyl children and that natural {beta

  3. Effects of beta-blockade on atrial and atrioventricular nodal refractoriness, and atrial fibrillatory rate during atrial fibrillation in pigs

    NARCIS (Netherlands)

    van den Berg, MP; van de Ven, LLM; Witting, W; Crijns, JGM; Haaksma, J; Bel, KJ; de Langen, CDJ; Lie, KI

    1997-01-01

    Despite their widespread use in atrial fibrillation, the effects of beta-adrenoceptor blockers on atrial and atrioventricular (AV) nodal refractoriness, and atrial fibrillatory rate during atrial fibrillation have been incompletely characterised. In particular, it is unknown whether additional sodiu

  4. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  5. Iron diminishes the in vitro biological effect of vanadium.

    Science.gov (United States)

    Mechanistic pathways underlying inflammatory injury following exposures to vanadium-containing compounds are not defined. We tested the postulate that the in vitro biological effect of vanadium results from its impact on iron homeostasis. Human bronchial epithelial (HBE) cells ex...

  6. Critical appraisal: dental amalgam update--part II: biological effects.

    Science.gov (United States)

    Wahl, Michael J; Swift, Edward J

    2013-12-01

    Dental amalgam restorations have been controversial for over 150 years. In Part I of this Critical Appraisal, the clinical efficacy of dental amalgam was updated. Here in Part II, the biological effects of dental amalgam are addressed.

  7. Hormesis [Biological Effects of Low Level Exposures (Belle)] and Dermatology

    OpenAIRE

    Thong, Haw-Yueh; Maibach, Howard I.

    2008-01-01

    Hormesis, or biological effects of low level exposures (BELLE), is characterized by nonmonotonic dose response which is biphasic, displaying opposite effects at low and high dose. Its occurrence has been documented across a broad range of biological models and diverse type of exposure. Since hormesis appears to be a relatively common phenomenon in many areas, the objective of this review is to explore its occurrence related to dermatology and its public health and risk assessment implication....

  8. Biological effects of exposure to magnetic resonance imaging: an overview

    OpenAIRE

    Formica Domenico; Silvestri Sergio

    2004-01-01

    Abstract The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to a...

  9. Effect of cosmic ray/X-ray ionization on supermassive black hole formation

    CERN Document Server

    Inayoshi, Kohei

    2011-01-01

    We study effects of external ionization by cosmic rays (CRs) and X-rays on the thermal evolution of primordial clouds under strong far-ultraviolet (FUV) radiation. A strong FUV radiation dissociates H2 and quenches its cooling. Even in such an environment, a massive cloud with Tvir>10^4 K can contract isothermally at 8000 K by Lyman alpha cooling. This cloud collapses monolithically without fragmentation, and a supermassive star (>10^5 Msun) is believed to form at the center, which eventually evolves to a supermassive black hole (SMBH). However, candidates of FUV sources, including star-forming galaxies, are probably sources of strong CRs and X-rays, as well. We find that the external ionization promotes H2 production and elevates the threshold FUV intensity Jcr needed for the SMBH formation for CR energy density U_CR>10^-14 erg/cm^3 or X-ray intensity J_X>10^-24 erg/s/cm^2/sr/Hz at 1 keV. The critical FUV flux increases in proportion to U_CR^{1/2} (J_X^{1/2}) in the high CR (X-ray, respectively) limit. With ...

  10. Biological Effects of the Great Oxidation Event

    Science.gov (United States)

    Schopf, J.

    2012-12-01

    Fossil evidence of photoautotrophy, documented in Precambrian sediments by stromatolites, stromatolitic microfossils, and carbon isotopic data consistent with autotrophic CO2-fixation, extends to ~3,500 Ma. Such data, however, are insufficient to establish the time of origin of O2-producing (cyanobacterial) photosynthesis from its anoxygenic, photosynthetic bacterial, evolutionary precursor. The oldest (Paleoarchean) stromatolites may have been formed by anoxygenic photoautotrophs, rather than the cyanobacteria that dominate Proterozoic and modern stromatolites. Unlike the cyanobacteria of Proterozoic microbial assemblages, the filamentous and coccoidal microfossils of Archean deposits may represent remnants of non-O2-producing prokaryotes. And although the chemistry of Archean organic matter shows it to be biogenic, its carbon isotopic composition is insufficient to differentiate between oxygenic and anoxygenic sources. Though it is well established that Earth's ecosystem has been based on autotrophy since its early stages and that O2-producing photosynthesis evolved earlier, perhaps much earlier, than the increase of atmospheric oxygen in the ~2,450 and ~2,320 Ma Great Oxidation Event (GOE), the time of origin of oxygenic photoautotrophy has yet to be established. Recent findings suggest that Earth's ecosystem responded more or less immediately to the GOE. The increase of atmospheric oxygen markedly affected ocean water chemistry, most notably by increasing the availability of biologically usable oxygen (which enabled the development of obligate aerobes, such as eukaryotes), and of nitrate, sulfate and hydrogen sulfide (the increase of H2S being a result of microbial reduction of sulfate), the three reactants that power the anaerobic basis of sulfur-cycling microbial sulfuretums. Fossil evidence of the earliest eukaryotes (widely accepted to date from ~1800 Ma and, arguably, ~2200 Ma) fit this scenario, but the most telling example of life's response to the GOE

  11. Can {alpha}-tocopherol and {beta}-carotene supplementation reduce adverse radiation effects on salivary glands?

    Energy Technology Data Exchange (ETDEWEB)

    Funegaard, U.; Johansson, I.; Ericson, T. [Umeaa Univ. (Sweden). Dept. of Cariology; Malmer, B.; Henriksson, R. [Umeaa Univ. (Sweden). Dept. of Oncology

    1995-12-31

    In this study, we evaluated whether supplementation with antioxidant vitamins can reduce the adverse effects of irradiation on the salivary glands in the rat. Four groups of adult Sprague-Dawley rats were given a basic diet providing 0.6 mg {alpha}-tocopherol and no {beta}-carotene per day. In two groups the basic diet was supplemented with 3.4 mg {alpha}-tocopherol and 6 mg {beta}-carotene per day from 14 days before irradiation until 12 days after complete irradiation. One group of rats given basic diet and one group given supplemented diet were irradiated with 7 Gy daily for five consecutive days. Isoproterenol and pilocarpine-stimulated whole saliva was collected from all rats 2, 4 and 26 weeks after irradiation. Vitamin-supplemented irradiated rats had higher secretion rates on all three occasions compared with those of irradiated rats given basic diet. The changes in saliva composition seen in irradiated rats were less accentuated in vitamin-supplemented, irradiated rats. The proportions of acinar cells were significantly decreased both in parotid and submandibular glands 26 weeks after irradiation. Supplementation with {alpha}-tocopherol and {beta}-carotene did not alter the morphology of the glands. (author).

  12. [Central effects of five beta-adrenergic receptor blockers in healthy volunteers: a quantitative EEG study].

    Science.gov (United States)

    Sabot, C; Pechadre, J C; Beudin, P; Lauxerois, M; Trolese, J F; Kantelip, J P; Ducher, J L; Gibert, J

    1989-03-01

    The effects of five beta blockers on the central nervous system of healthy subjects was studied by computerized EEG analysis. All subjects underwent continuous recording with a Holter magnetic type recorder during the experimental period. For 10 consecutive days, five groups of subjects received alternately placebo and the beta blockers acebutolol 600 mg, carteolol 20 mg, metoprolol 200 mg, pindolol 30 mg and sotalol 320 mg. EEG recordings (C4/P4, P4/02 and C3/P3, P3/01) lasting 5 min were made between 8.30 and 9.30 a.m. Subjects were at rest with eyes closed and there was no vigilance control. The signal was recorded on a magnetic tape recorder and then processed by Nicolet MED 80 system. Comparisons of absolute and relative powers and of average frequencies were then made between the different sequences and groups. The possible correlations between the changes observed in the power spectrum and the clinical, pharmacological and pharmacokinetic specific properties of each beta blocker are discussed.

  13. Differential effects of ongoing EEG beta and theta power on memory formation

    Science.gov (United States)

    Scholz, Sebastian; Schneider, Signe Luisa

    2017-01-01

    Recently, elevated ongoing pre-stimulus beta power (13–17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13–17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3–7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information. PMID:28192459

  14. Low immunogenicity but reduced bioavailability of an interferon beta-1a biosimilar compared with its biological parent: results of MATRIX, a cross-sectional, multicenter phase 4 study

    Directory of Open Access Journals (Sweden)

    Cuevas C

    2015-09-01

    Full Text Available Carlos Cuevas,1 Florian Deisenhammer,2 Xiaojun You,3 Mariano Scolnik,4 Regine Buffels,3 Bjørn Sperling,3 Francisco Flores-Ramírez,5 Miguel Macías-Islas,6 Sergio Sauri-Suárez7 On behalf of the MATRIX Investigator Group 1Specialty Hospital, Department of Neurology, National Medical Center Siglo XXI, Mexican Institute of Social Security, Mexico City, Mexico; 2Department of Neurology, University of Innsbruck, Innsbruck, Austria; 3Biogen, Cambridge, MA, USA; 4Biogen, Argentina, Buenos Aires, Argentina; 5Department of Internal Medicine–Neurology, Hospital Regional ISSSTE Monterrey, Monterrey, 6University Center for Health Sciences, University of Guadalajara, Guadalajara, 7Internal Medicine/Department of Neurology, National Medical Center, Mexico City, Mexico Abstract: MATRIX (Measuring neutralizing Antibodies in patients TReated with Interferon beta-1a IM in MeXico was primarily a cross-sectional phase 4 study of patients with relapsing multiple sclerosis (RMS that evaluated neutralizing antibody (NAb frequency in Mexican and Colombian patients treated with intramuscular interferon (IFN beta-1a in the form of Avonex® or the biosimilar drug Jumtab®. A secondary long-term retrospective observational evaluation of safety, tolerability, and relapses was also performed for patients in each arm of the study. In the cross-sectional portion of the study, patients with multiple sclerosis who had been treated with once-weekly Avonex (n=36 or Jumtab (n=29 self-injections as their first and only disease-modifying therapy for 1–3 years were retrospectively identified. The primary and secondary endpoints were proportion of patients with NAb levels >100 tenfold reduction units (TRU and >20 TRU. The biological response to IFN beta-1a injections was assessed by change in serum neopterin levels and by pre- versus post-dose concentration difference. Safety, tolerability, and relapse-related information were also retrospectively assessed. No patients developed

  15. Lack of effect of beta-blocker on flat dose response to thiazide in hypertension: efficacy of low dose thiazide combined with beta-blocker.

    OpenAIRE

    1983-01-01

    Increasing the dose of a thiazide diuretic used alone in patients with essential hypertension has little further effect on blood pressure but increases the deleterious metabolic consequences of the diuretic. The effect of a beta-blocker on this flat dose response is not known. In two randomised crossover studies the effect of 12.5 mg, 25 mg, and 50 mg hydrochlorothiazide combined with 400 mg acebutolol was assessed. The mean fall in supine blood pressure was about 15% and was the same whateve...

  16. Antidiuretic effect of ritodrine with and without beta-adrenergic blockade.

    Science.gov (United States)

    Gerritse, R; Pinas, I M; Reuwer, P J; Haspels, A A; Charbon, G A; Beijer, H J

    1985-11-01

    Dose-related effects of ritodrine and ritodrine combined with metoprolol on urinary excretion rate were studied in anesthetized dogs. Urine production was abruptly reduced after a total dose of 4 micrograms.kg-1 of ritodrine. This effect could not be antagonized by metoprolol, although the ritodrine-induced decrease of mean arterial pressure and renal arterial blood flow was significantly inhibited. The possible role of fluid retention during tocolytic treatment, even with beta-adrenergic blockade, in the etiology of pulmonary edema is discussed with a review on recent literature.

  17. Effect of beta-blocker therapy on functional status in patients with heart failure--a meta-analysis

    DEFF Research Database (Denmark)

    Abdulla, Jawdat; Køber, Lars; Christensen, Erik

    2005-01-01

    BACKGROUND: The results of randomised control trials (RCTs) evaluating the effect of beta-blockers on functional status in patients with chronic heart failure are conflicting. AIM: To perform a systematic review and meta-analysis of RCTs evaluating the effect of beta-blockers on New York Heart...... Association (NYHA) classification and exercise tolerance in chronic heart failure. METHODS AND RESULTS: We selected 28 RCTs evaluating beta-blocker versus placebo in addition to ACE inhibitor therapy. Combined results of 23 RCTs showed that beta-blockers improved NYHA class by at least one class with odds...... ratio (OR) 1.80 (1.33-2.43) pbeta-blockers had no significant effect...

  18. Simulation on the molecular radiosensitization effect of gold nanoparticles in cells irradiated by x-rays.

    Science.gov (United States)

    Xie, W Z; Friedland, W; Li, W B; Li, C Y; Oeh, U; Qiu, R; Li, J L; Hoeschen, C

    2015-08-21

    Abundant studies have focused on the radiosensitization effect of gold nanoparticles (GNPs) in the cellular environment with x-ray irradiation. To better understand the physical foundation and to initially study the molecular radiosensitization effect within the nucleus, a simple cell model with detailed DNA structure in the central nucleus was set up and complemented with different distributions of single and multiple GNPs in this work. With the biophysical Monte Carlo simulation code PARTRAC, the radiosensitization effects on both physical quantities and primary biological responses (DNA strand breaks) were simulated. The ratios of results under situations with GNPs compared to those without GNPs were defined as the enhancement factors (EFs). The simulation results show that the presence of GNP can cause a notable enhancement effect on the energy deposition within a few micrometers from the border of GNP. The greatest upshot appears around the border and is mostly dominated by Auger electrons. The enhancement effect on the DNA strand breakage becomes smaller because of the DNA distribution inside the nucleus, and the corresponding EFs are between 1 and 1.5. In the present simulation, multiple GNPs on the nucleus surface, the 60 kVp x-ray spectrum and the diameter of 100 nm are relatively more effective conditions for both physical and biological radiosensitization effects. These results preliminarily indicate that GNP can be a good radiosensitizer in x-ray radiotherapy. Nevertheless, further biological responses (repair process, cell survival, etc) need to be studied to give more accurate evaluation and practical proposal on GNP's application in clinical treatment.

  19. Hydrothermal Aging Effects on Fe/SSZ-13 and Fe/Beta NH3–SCR Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng; Szanyi, János; Wang, Yilin; Schwenzer, Birgit; Kollár, Márton; Peden, Charles H. F.

    2016-05-05

    Cu/SSZ-13 has been successfully commercialized as a diesel engine exhaust aftertreatment SCR catalyst in the past few years. This catalyst, however, displays undesirable NH3-SCR selectivity at elevated reaction temperature (≥ 350 C) after hydrothermal aging. Fe/zeolites, despite the fact that most of them degrade beyond tolerance after hydrothermal aging at temperatures ≥ 650 C, typically maintain good SCR selectivities. In recent years, Fe/beta has been identified as one of the more robust Fe/zeolites for use in NH3-SCR, where activity maintains even after hydrothermal aging at 750 C. Very recently, we, for the first time, synthesized and tested NH3-SCR performance for fresh and hydrothermally aged Fe/SSZ-13 catalysts. This study demonstrated that Fe/SSZ-13 is also a promising robust SCR catalyst, especially for high-temperature applications. In the present study, we compare catalytic performance between Fe/SSZ-13 and Fe/beta with similar Fe loadings and Si/Al ratios. Special attention is paid to effects from hydrothermal aging, aiming to understanding similarities and differences between these two catalysts. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Program for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  20. Submillimeter nuclear medical imaging with a Compton Camera using triple coincidences of collinear \\beta+ annihilation photons and \\gamma-rays

    CERN Document Server

    Lang, C; Thirolf, P G; Zoglauer, A

    2012-01-01

    Modern PET systems reach a spatial resolution of 3-10 mm. A disadvantage of this technique is the diffusion of the positron before its decay with a typical range of ca. 1 mm (depending on its energy). This motion and Compton scattering of the 511 keV photons within the patient limit the performance of PET. We present a nuclear medical imaging technique, able to reach submillimeter spatial resolution in 3 dimensions with a reduced activity application compared to conventional PET. This 'gamma-PET' technique draws on specific positron sources simultaneously emitting an additional photon with the \\beta+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to test the feasibility of this technique, Monte-Carlo simulations and image reconstruction has been performed. The spatial resolution amounts to 0.2 mm (FWHM) in each direction, surpassing the performance of conventional PET by about...

  1. Stimulatory effect of Crocus sativus (saffron) on beta2-adrenoceptors of guinea pig tracheal chains.

    Science.gov (United States)

    Nemati, H; Boskabady, M H; Ahmadzadef Vostakolaei, H

    2008-12-01

    To study the mechanism(s) of the relaxant effects of Crocus sativus (Iridaceae), the stimulatory effect of aqueous-ethanolic extracts of this plant and one of its constituent, safranal was examined on beta-adrenoceptors in tracheal chains of guinea pigs. The beta(2)-adrenergic stimulatory was tested by performing the cumulative concentration-response curves of isoprenaline-induced relaxation of pre-contracted isolated guinea pig tracheal chains. The studied solutions were included two concentrations of aqueous-ethanolic extract from Crocus sativus (0.1 and 0.2g%), safranal (1.25 and 2.5 microg), 10nM propranolol, and saline. The study was done in two different conditions including: non-incubated (group 1, n=9) and incubated tissues with 1 microM chlorpheniramine (group 2, n=6). The results showed clear leftward shifts in isoprenaline curves obtained in the presence of only higher concentration of the extract in group 1 and its both concentrations in group 2 compared with that of saline. The EC(50) (the effective concentration of isoprenaline, causing 50% of maximum response) obtained in the presence of both concentrations of the extract (0.17+/-0.06 and 0.12+/-0.02) and safranal (0.22+/-0.05 and 0.22+/-0.05) in group 1 and only in the presence of two concentrations of the extract (1.16+/-0.31 and 0.68+/-0.21) in group 2 was significantly lower compared to saline (1.00+/-0.22 and 4.06+/-1.04 for groups 1 and 2, respectively) (pCrocus sativus on beta(2)-adrenoceptors which is partially due to its constituent, safranal. A possible inhibitory effect of the plant on histamine (H(1)) receptors was also suggested.

  2. Effect of cosmic ray on global high cloud from MODIS

    Science.gov (United States)

    Kim, H.-S.; Choi, Y.-S.

    2012-04-01

    than low and middle clouds. Considering the correlations with dependence on regions, a physical cloud process regarding to cosmic ray may not be universal perhaps due to anonymous factors affecting the cloud amount. However, our synthetic conclusion is that the amount of global high cloud increases with increased cosmic ray. This implies that infrared warming effect due to increased high cloud may be intensified when more cosmic ray comes in.

  3. Crystallization and preliminary X-ray diffraction analysis of the Fab fragment of WO2, an antibody specific for the A[beta] peptides associated with Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Wun, Kwok S.; Miles, Luke A.; Crespi, Gabriela A.N.; Wycherley, Kaye; Ascher, David B.; Barnham, Kevin J.; Cappai, Roberto; Beyreuther, Konrad; Masters, Colin L.; Parker, Michael W.; McKinstry, William J. (SVIMR-A); (HeidelbergU); (WEHI); (Melbourne)

    2008-05-28

    The murine monoclonal antibody WO2 specifically binds the N-terminal region of the amyloid {beta} peptide (A{beta}) associated with Alzheimer's disease. This region of A{beta} has been shown to be the immunodominant B-cell epitope of the peptide and hence is considered to be a basis for the development of immunotherapeutic strategies against this prevalent cause of dementia. Structural studies have been undertaken in order to characterize the molecular basis for antibody recognition of this important epitope. Here, details of the crystallization and X-ray analysis of the Fab fragment of the unliganded WO2 antibody in two crystal forms and of the complexes that it forms with the truncated Az{beta} peptides A{beta}{sub 1-16} and A{beta}{sub 1-28} are presented. These crystals were all obtained using the hanging-drop vapour-diffusion method at 295 K. Crystals of WO2 Fab were grown in polyethylene glycol solutions containing ZnSO{sub 4}; they belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} and diffracted to 1.6 {angstrom} resolution. The complexes of WO2 Fab with either A{beta}{sub 1-16} or A{beta}{sub 1-28} were cocrystallized from polyethylene glycol solutions. These two complex crystals grew in the same space group, P2{sub 1}2{sub 1}2{sub 1}, and diffracted to 1.6 {angstrom} resolution. A second crystal form of WO2 Fab was grown in the presence of the sparingly soluble A{beta}{sub 1-42} in PEG 550 MME. This second form belonged to space group P2{sub 1} and diffracted to 1.9 {angstrom} resolution.

  4. Differential effect on serum neopterin and serum beta 2-microglobulin is induced by treatment in Pneumocystis carinii pneumonia

    DEFF Research Database (Denmark)

    Benfield, T L; Schattenkerk, J K; Hofmann, B

    1994-01-01

    Forty-three human immunodeficiency virus-infected patients with Pneumocystis carinii pneumonia (PCP) were enrolled in a study of adjunctive corticosteroid treatment for 10 days versus placebo, in addition to antimicrobial treatment. Levels of neopterin and beta 2-microglobulin (beta 2M) were......% and approximately 30%, respectively, and returned to baseline after discontinuation of corticosteroid treatment. Antimicrobial treatment alone did not affect either neopterin or beta 2M in healthy controls. Results indicate that treatment has a differential effect on the immune response: increased macrophage...... activation leading to neopterin production and decreased production of beta 2M by lymphocytes. Further, addition of corticosteroids modified and decreased this immune activation and may explain the earlier demonstrated beneficial effect of corticosteroids in PCP treatment....

  5. Involvement of PLC-beta3 in the effect of morphine on memory retrieval in passive avoidance task.

    Science.gov (United States)

    Bianchi, E; Lehmann, D; Vivoli, E; Norcini, M; Ghelardini, C

    2010-06-01

    Phospholipase C (PLC) is one signalling effector enzyme whose activity is directly modulated by opioids. Several physiological studies have implicated PLC-linked pathways in in-vivo pain regulation and opioid tolerance. Co-administration of PLC-beta(2/3) activity blocker M119 with morphine resulted in a dramatic increase in morphine-induced amnesic effect in mice, proving a role for beta subunit of PLC enzyme in these processes. Administration of morphine to mice at amnesic dose increased PLC-beta(3) activity, with respect to basal value, in the membrane-soluble material from anterior cortex and hippocampal formation in brain areas. PLC-beta(3) appears to be simultaneously implicated in both analgesic and amnesic effects induced by administration of morphine to mice suggesting a commonality in the molecular mechanisms of morphine-induced analgesia and memory impairment.

  6. Effect of beta-adrenergic blockade on elevated arterial compliance and low systemic vascular resistance in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    2001-01-01

    with beta-blockers, but the effect of this treatment on arterial compliance has not been investigated. The aim of the present study was therefore to assess the effects of propranolol on the arterial compliance of patients with cirrhosis. METHODS: Twenty patients with cirrhosis underwent a haemodynamic......) of 17.8 mmHg, and responded to beta-blocker treatment with a significant reduction in the HVPG (-16%; P beta-adrenergic blockade (1.27 versus 1.29 ml/mmHg, +2%, ns), whereas...... with beta-blockers increases small vessel (arteriolar) vascular tone towards the normal level, but does not affect the elevated compliance of the larger arteries in patients with cirrhosis....

  7. Beta Thalassemia

    Science.gov (United States)

    Beta thalassemia is found in people of Mediterranean, Middle Eastern, African, South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin genes found on chromosomes ...

  8. A mini X-ray generator as an alternative to a 90Sr/90Y beta source in luminescence dating

    DEFF Research Database (Denmark)

    Andersen, C.E.; Bøtter-Jensen, L.; Murray, A.S.

    2003-01-01

    We have carried out an investigation to test whether mini X-ray generators are a suitable alternative to radioactive sources in luminescence dating. The study has mainly been motivated by the need for high dose rates (similar to 1 Gy/s) to make dating of older samples using regeneration protocols...... more practical. Furthermore, X-ray generators are more suited for field work and work in countries where regulations restrict the use of radioactive sources. The system tested here (a 50 kV I mA Varian VF-50J tube with tungsten target and a matched Spellman high-voltage power supply) was found...... to provide: (i) excellent linearity between tube current (as set by the user on the control computer) and dose rate, (ii) a wide dynamic range: 2-30 mGy/s at 10 kV and 10-2000 mGy/s at 50 kV, (iii) short-term stability better than 0.2%, and (iv) a highly uniform irradiation of the sample area. Tests...

  9. Effects of beta-hydroxybutyrate and isoproterenol on lipolysis in isolated adipocytes from periparturient dairy cows and cows with clinical ketosis

    NARCIS (Netherlands)

    van der Drift, S. G. A.; Everts, R. R.; Houweling, M.; van Leengoed, L. A. M. G.; Stegeman, J. A.; Tielens, A. G. M.; Jorritsma, R.

    2013-01-01

    An in vitro model was used to investigate effects of beta-hydroxybutyrate and isoproterenol (beta-adrenergic receptor agonist) on lipolysis in isolated adipocytes from late pregnant and recently calved dairy cows (n = 5) and cows with clinical ketosis (n =3). Incubation with 3.0 mmol/L beta-hydroxyb

  10. The Effect of the Arg389Gly Beta-1 Adrenoceptor Polymorphism on Plasma Renin Activity and Heart Rate and the Genotype-Dependent Response to Metoprolol Treatment

    DEFF Research Database (Denmark)

    Petersen, Morten; Andersen, Jon T; Jimenez-Solem, Espen

    2012-01-01

    A gene-drug interaction has been indicated between beta-1 selective beta-blockers and the Arg389Gly polymorphism (rs1801253) in the adrenergic beta-1 receptor gene (ADRB1). We studied the effect of the ADRB1 Arg389Gly polymorphism on plasma renin activity (PRA) and heart rate (HR) and the genotype...

  11. Mechanism of the genetic mutagenesis effects of far infrared ray laser

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ling-yun; XU Lin; ZHANG Can-bang; WU Guang-min; LI Ling; WEN Chuan-jing; YANG Ji-sheng

    2005-01-01

    We have analyzed the order-disordering variance due to resonance effect and the nonlinear behavior of far infrared ray laser (FIRL)-biological system interaction.The analytic results show that the interaction between the living biological system and FIRL can produce resonance excitation effect,and so the original high ordered state of the system can be destroyed and thus the conformation variation in the system can be produced under further action of the laser.In addition,we have analyzed the nonlinear properties of the FIRL bio-molecule interaction and explained the mutagenesis effects of FIRL.The theoretic analysis is consistent with the results of FIRL mutagenesis breeding test.

  12. Effect of beta blockade on single photon emission computed tomographic (SPECT) thallium-201 images in patients with coronary disease

    Energy Technology Data Exchange (ETDEWEB)

    Narahara, K.A.; Thompson, C.J.; Hazen, J.F.; Brizendine, M.; Mena, I.

    1989-05-01

    We evaluated the effect of beta blockers on thallium-201 (Tl-201) single photon emission computed tomographic (SPECT) imaging in 12 patients with coronary disease using an automated computer algorithm. Maximal exercise heart rate and blood pressure were reduced and exercise time was increased with beta blockers. Estimated stress defect size decreased from 47 +/- 36.3 gm during placebo treatment to 32 +/- 27.1 gm during beta blocker therapy (-32%; p less than 0.01). The placebo treatment redistribution defect was estimated to be 28 +/- 29.8 gm. It fell to 15 +/- 23.3 gm with beta blockade (-46%; p less than 0.005). All patients had a stress Tl-201 defect during placebo treatment and eight had redistribution defects consistent with residual scar. During beta blocker therapy, 2 of 12 patients had normal stress-redistribution studies and only five patients had redistribution defects. Beta blockade can reduce exercise and redistribution Tl-201 SPECT defect size significantly while simultaneously increasing exercise time and reducing angina. Beta blockers may unmask or may eliminate evidence of redistribution. Tl-201 SPECT imaging may be useful in defining the reduction in ischemia produced by cardiac drugs.

  13. Fast Sausage Modes in Magnetic Tubes with Continuous Transverse Profiles: Effects of a Finite Plasma Beta

    Science.gov (United States)

    Chen, Shao-Xia; Li, Bo; Xiong, Ming; Yu, Hui; Guo, Ming-Zhe

    2016-12-01

    While standing fast sausage modes in flare loops are often invoked to interpret quasi-periodic pulsations (QPPs) in solar flares, it is unclear as to how they are influenced by the combined effects of a continuous transverse structuring and a finite internal plasma beta ({β }{{i}}). We derive a generic dispersion relation governing linear sausage waves in straight magnetic tubes for which plasma pressure is not negligible, and the density and temperature inhomogeneities of essentially arbitrary form take place in a layer of arbitrary width. Focusing on fast modes, we find that {β }{{i}} only weakly influences {k}{{c}}, the critical longitudinal wavenumber separating the leaky from trapped modes. Likewise, for both trapped and leaky modes, the periods P in units of the transverse fast time depend only weakly on {β }{{i}}, which is compatible with the fact that the effective wave vectors of fast sausage modes are largely perpendicular to the background magnetic field. However, a weak {β }{{i}} dependence of the damping times τ is seen only when the length-to-radius ratio L/R is ∼50% larger than some critical value π /({k}{{c}}R), which itself rather sensitively depends on the density contrast, profile steepness, as well as on how the transverse structuring is described. In the context of QPPs, we conclude that the much simpler zero-beta theory can be employed for trapped modes, as long as one sees the deduced internal Alfvén speed as actually being the fast speed. In contrast, effects due to a finite beta in flare loops should be considered when leaky modes are exploited.

  14. Leukocyte redistribution: effects of beta blockers in patients with chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Stephan von Haehling

    Full Text Available BACKGROUND: Overproduction of pro-inflammatory cytokines is a well established factor in the progression of chronic heart failure (CHF. Changes in cellular immunity have not been widely studied, and the impact of standard medication is uncertain. Here we investigate whether a leukocyte redistribution occurs in CHF and whether this effect is influenced by beta-blocker therapy. METHODOLOGY: We prospectively studied 75 patients with systolic CHF (age: 68+/-11 years, left ventricular ejection fraction 32+/-11%, New York Heart Association class 2.5+/-0.7 and 20 age-matched healthy control subjects (age: 63+/-10 years. We measured the response of cells to endotoxin exposure in vitro, analysed subsets of lymphocytes using flow cytometry, and assessed plasma levels of the pro-inflammatory markers interleukin 1, 6, tumor necrosis factor-alpha, and soluble tumor necrosis factor receptors 1 and 2. PRINCIPAL FINDINGS: While no differences in the number of leukocytes were noted between patients with CHF and healthy controls, we detected relative lymphopenia in patients with CHF (p<0.001 vs. control, mostly driven by reductions in T helper cells and B cells (both p<0.05. The number of neutrophils was increased (p<0.01. These effects were pronounced in patients who were beta-blocker naïve (32% of all patients with CHF. Increased plasma levels of soluble tumor necrosis receptor-1 correlated with the relative number of lymphocyte subsets. CONCLUSIONS: In patients with CHF, we detected a redistribution of leukocyte subsets, i.e. an increase in neutrophils with relative lymphopenia. These effects were pronounced in patients who were beta-blocker naïve. The underlying mechanism remains to be elucidated.

  15. Negative effect of 17-beta-estradiol on growth parameters of goldifsh (Carassius auratus)

    Institute of Scientific and Technical Information of China (English)

    Reza Tarkhani; Mohammad Reza Imanpoor; Mohammad Forouhar Vajargah; Sayede Amene Hossain

    2015-01-01

    Objective:To evaluate the effects of 17-beta-estradiol on growth factors of goldfish (Carassius auratus). Methods:To perform the test, 17-beta-estradiol was given 3 months period to fish at different doses as followed: control group, Group 1: 10 mg/kg food, Group 2: 25 mg/kg food and Group 3: 50 mg/kg food. For this purpose, a solution of hormone in pure ethanol used to spray on food. Feeding was done 3 times daily as an appetite. Comparing the mean values measured for length and weight usingANOVA. Results:Indicated with increase length and weight, the effects of the hormone get more distinct, so that with increase concentration of hormone, reduce weight and length. Conclusions: Estradiol along with testosterone and progesterone regulates final stages of oocyte maturation and ovulation. Various studies have proven the different concentrations of this hormone has different effects on the growth of different fishes. The aim of this study was to assess the effects of this hormone on growth factors ofCarassius auratus.

  16. Monounsaturated fatty acids prevent the deleterious effects of palmitate and high glucose on human pancreatic beta-cell turnover and function

    OpenAIRE

    Maedler, Kathrin; Oberholzer, José; Bucher, Pascal Alain Robert; Spinas, Giatgen A.; Donath, Marc

    2003-01-01

    Glucotoxicity and lipotoxicity contribute to the impaired beta-cell function observed in type 2 diabetes. Here we examine the effect of saturated and monounsaturated fatty acids at different glucose concentrations on human beta-cell turnover and secretory function. Exposure of cultured human islets to saturated fatty acid and/or to an elevated glucose concentration for 4 days increased beta-cell DNA fragmentation and decreased beta-cell proliferation. In contrast, the monounsaturated palmitol...

  17. Analysis of MIR-18 results for physical and biological dosimetry: radiation shielding effectiveness in LEO

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Williams, J. R.; Dicello, J. F.

    2000-01-01

    We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio will increase for exposures to internal organs. Two biological response models are used to compare to the Mir biodosimetry for chromosome aberration in lymphocyte cells; a track-structure model and the linear-quadratic model with linear energy transfer (LET) dependent weighting coefficients. These models are fit to in vitro data for aberration formation in human lymphocytes by photons and charged particles. Both models are found to be in reasonable agreement with data for aberrations in lymphocytes of Mir crew members: however there are differences between the use of LET dependent weighting factors and track structure models for assigning radiation quality factors. The major difference in the models is the increased effectiveness predicted by the track model for low charge and energy ions with LET near 10 keV/micrometers. The results of our calculations indicate that aluminum shielding, although providing important mitigation of the effects of trapped radiation, provides no protective effect from the galactic cosmic rays (GCR) in low-earth orbit (LEO) using either equivalent dose or the number of chromosome aberrations as a measure until about 100 g/cm 2 of material is used.

  18. X-ray versus gamma irradiation effects on polymers

    Energy Technology Data Exchange (ETDEWEB)

    Croonenborghs, B. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium); Smith, M.A. [Sterigenics International, 10811 Withers Cove Park Drive, Charlotte, NC 28278 (United States); Strain, P. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium)], E-mail: pstrain@eu.sterigenics.com

    2007-11-15

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to {sup 60}Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  19. Effects of beta interferon on human fibroblasts at different population doubling levels. Proliferation, cell volume, thymidine uptake, and DNA synthesis

    OpenAIRE

    1984-01-01

    Cellular aging had no effect on the ability of beta interferon to increase cell volume and population doubling time in 76-109 cells, a line of human skin fibroblasts. However, DNA synthesis in cells at high population doubling levels (PDL 55-70) was inhibited after 72 h of beta interferon treatment (1,000 U/ml) while no inhibition of DNA synthesis was observed in cells at middle population doubling levels (PDL 30-40).

  20. Effect of clavulanic acid on the activities of ten beta-lactam agents against members of the Bacteroides fragilis group.

    Science.gov (United States)

    Lamothe, F; Auger, F; Lacroix, J M

    1984-01-01

    Clavulanic acid reduced the MICs of amoxicillin, carbencillin , cefamandole, cefotaxime, ceftazidime, ceftizoxime, cephalothin, and penicillin G, but not of cefoxitin or moxalactam, against 77 isolates of the Bacteroides fragilis group, all rapidly beta-lactamase positive by the nitrocefin slide test. It had no effect on the susceptibilities of eight Bacteroides distasonis strains that were slowly beta-lactamase positive (18 h of incubation). PMID:6732233

  1. Biological Dosimetry of X-rays by micronuclei study; Dosimetria Biologica de rayos-X mediante el estudio de micronucleos

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, E.; Silva, A.; Navlet, J.

    1991-07-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical an cytogenetics data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable, in this case, the study of micronuclei in peripheral blood lymphocytes citokinetics blocked can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using micronuclei assay for X-rays at 250 kVp, 43,79 rads/min and temperature 37 degree centigree has been produced. Experimental data is fitted to model Y=C+ {alpha}D+BD''2 where Y is the number of micronuclei per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 24 refs.

  2. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    DEFF Research Database (Denmark)

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen

    2002-01-01

    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway....... Furthermore, using Northern blot analysis it was shown that SOCS-3 can completely inhibit GH-induced insulin production in these cells. Finally, 5-bromodeoxyuridine incorporation followed by fluorescence-activated cell sorting analysis showed that SOCS-3 inhibits GH-induced proliferation of INS-1 cells...

  3. The effects of moderate drinking and abstinence on serum and urinary beta-hexosaminidase levels.

    Science.gov (United States)

    Kärkkäinen, P; Jokelainen, K; Roine, R; Suokas, A; Salaspuro, M

    1990-02-01

    The effects of moderate alcohol intake on serum (SHEX)- and urinary beta-hexosaminidase (UHEX) were studied in ten healthy volunteers, who ingested 60 g of 100% ethanol daily for 10 days. The drinking period was preceded and followed by an abstinence period. Moderate drinking and abstinence were rapidly and significantly reflected on SHEX, while UHEX levels did not change significantly during the study. Gramma-glutamyl transpeptidase (GGT), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) decreased during the first abstinence period (P less than 0.05), but stayed thereafter at a constant level. It is concluded that SHEX may better reflect recent alcohol consumption than UHEX, GGT, ASAT or ALAT.

  4. Biological response to ionizing radiation in mouse embryo fibroblasts with a targeted disruption of the DNA polymerase beta gene.

    Science.gov (United States)

    Miura, M; Watanabe, H; Okochi, K; Sasaki, T; Shibuya, H

    2000-06-01

    Base excision repair (BER) is carried out by two distinct pathways in mammalian cells, one dependent on DNA polymerase beta (Polb) and the other on proliferating cell nuclear antigen (Pcna). We studied whether the Polb-dependent pathway plays an important role in BER in vivo after exposure to ionizing radiation. For this purpose, we used mouse embryo fibroblasts derived from wild-type and Polb gene knockout littermates. Both cell lines had essentially the same clonogenic cell survival and low levels of apoptosis as determined by a colony formation assay and by a change in mitochondrial membrane potential, respectively. No significant cleavage of protein kinase C delta (Pkcd) in vivo, which is a substrate for caspase 3, was detected, and intact Pkcd was retained in both cell lines for at least 72 h after irradiation. Similar significant increases in caspase 3-like activities as measured by Asp-Glu-Val-Asp (DEVD) cleaving activity in vitro were observed in both cell lines after irradiation. Radiation induced cell cycle arrest in the form of a G(2)-phase block, and G(2)/M-phase fractions reached a peak approximately 10 h after irradiation and decreased thereafter with a similar time course in both cell lines. Similar levels of chromatin-bound Pcna were observed immediately after irradiation in non-S-phase cells of both cell lines and disappeared by 4 h after irradiation. We conclude that the deficiency in Polb does not have a significant influence on the radiation responses of these cells. Together with evidence accumulated in vitro, these results strongly support the idea that the Pcna-dependent pathway predominantly acts in BER of radiation-induced DNA damage in vivo.

  5. Biological effects of fruit and vegetables

    DEFF Research Database (Denmark)

    Dragsted, L. O.; Krath, B.; Ravn-Haren, Gitte;

    2006-01-01

    , providing 600hairspg fruit and vegetables/d or in the controls a carbohydrate-rich drink to balance energy intake. Surrogate markers of oxidative damage to DNA, protein and lipids, enzymic defence and lipid metabolism were determined in blood and urine. It was found that a high intake of fruit......A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidants......, enzyme inducers, apoptosis inducers etc. In human intervention studies the dose levels achieved tend to be lower than the levels found to be effective in animals and sampling from target organs is often not possible. A controlled dietary human intervention study was performed with forty-three volunteers...

  6. Biological and therapeutical effects of Radon

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P. [Institute of Physiologie and Balneologie, University of Innsbruck (Austria)

    1998-12-31

    In spas with a somewhat elevated Radon{sup 222} (Rn) activity (between 300 and 3000 Bq/l), the empirical medicine ended - in all parts of the world - with the same list of indications. It mainly includes the more painful rheumatic diseases such as deformation or degeneration of the joints and non bacterial inflammation of muscles, tendons or joints; Morbus Bechterew and other diseases of the vertebral column like spondylosis, spondylarthrosis or osteochondrosis. While informer times these effects were seldom documented in an objective manner, in recent years several prospective randomized double-blind studies proved the pain reducing efficacy of Radon therapy in patients with cervical pain syndromes, with chronic polyarthritis or with Morbus Bechterew. Studies in experimental animal models have accumulated remarkable data in organs, tissue and cultured cells that provide a rationale to explain the observed effects of Radon therapy in patients. (author)

  7. Palytoxin and Analogs: Biological and Ecological Effects

    Directory of Open Access Journals (Sweden)

    Vítor Ramos

    2010-06-01

    Full Text Available Palytoxin (PTX is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems.

  8. Effectiveness of beta-blocker therapy in daily practice patients with advanced chronic heart failure; is there an effect-modification by age?

    NARCIS (Netherlands)

    Dobre, D.; deJongste, M.J.L.; Lucas, C.; Cleuren, G.; van Veldhuisen, D.J.; Ranchor, A.V.; Haaijer-Ruskamp, F.

    2007-01-01

    Aims The effects of beta-blockers in daily practice patients with advanced chronic heart failure (CHF) and a broad range of ejection fraction (EF) are not well established. We aimed to assess, first, the association between beta-blocker prescription at discharge and mortality in a cohort of patients

  9. Construction of a tissue engineered intervertebral disc with high biological activity using an allogeneic intervertebral disc supplemented with transfected nucleus pulposus cells expressing exogenous dopamine beta-hydroxylase.

    Science.gov (United States)

    Bai, M; Wang, Y H; Yin, H P; Li, S W

    2015-09-09

    This study addressed the in vitro construction and biological activity of tissue engineered intervertebral discs with exogenous human dopamine beta-hydroxylase (DBH) nucleus pulposus cells. pSNAV2.0-DBH expression plasmids were utilized to enhance the survival rates of intervertebral disc tissue cells. Various concentrations of transfected nucleus pulposus cells were injected into the discs, and DBH mRNA expression was determined using polymerase chain reaction amplification. Polysaccharide content and total collagen protein content in the engineered disc nucleus pulposus tissue were determined. The visible fluorescence intensities of the 1 x 10(5) and 1 x 10(6) groups vs the 1 x 10(4) group were significantly increased (P 0.05) at 7 days after injection. DBH mRNA expression could be detected in the all but the EGFP control group at 14 days culture. No significant difference was observed in the protein content between the 1 x 10(4) and the control groups at various times, while the protein content was significantly higher in the 1 x 10(5) vs the control and the 1 x 10(4) groups at 7-, 14-, and 21-day cultures. These results demonstrate that a tissue engineered intervertebral disc with high biological activity can be constructed by utilizing allogeneic intervertebral discs stored in liquid nitrogen and a 1 x 10(5) transfected nucleus pulposus cell complex with in vitro culture for 14 days. This model can be used in animal experiments to study the biological activity of the engineered discs.

  10. Linking exposure to environmental pollutants with biological effects

    DEFF Research Database (Denmark)

    Sørensen, Mette; Autrup, Herman; Møller, Peter

    2003-01-01

    Exposure to ambient air pollution has been associated with cancer. Ambient air contains a complex mixture of toxics, including particulate matter (PM) and benzene. Carcinogenic effects of PM may relate both to the content of PAH and to oxidative DNA damage generated by transition metals, benzene......, metabolism and inflammation. By means of personal monitoring and biomarkers of internal dose, biologically effective dose and susceptibility, it should be possible to characterize individual exposure and identify air pollution sources with relevant biological effects. In a series of studies, individual......, biological effects of air pollutants appear mainly related to oxidative stress via personal exposure and not to urban background levels. Future developments include personal time-resolved monitors for exposure to ultrafine PM and PM(2.5,) use of GPS, as well as genomics and proteomics based biomarkers....

  11. Interleukin-1 beta induced transient diabetes mellitus in rats. A model of the initial events in the pathogenesis of insulin-dependent diabetes mellitus?

    DEFF Research Database (Denmark)

    Reimers, J I

    1998-01-01

    , compared to the effects of IL-1 beta on rat beta cell function. Finally, this review discussed the effects of IL-1 beta on human beta cells in vitro, and the clinical relevance of these experiments, with special reference to a clinical trial with the aim of preventing IDDM in man. The pharmacokinetic...... parameters of the absorption and biological activity of IL-1 beta after peripheral injection. Injections of rhIL-1 beta to normal, non-diabetes prone rats induced initial beta cell stimulation followed by inhibition, in accordance with in vitro data. Furthermore, induction of peripheral insulin resistance...... edema and microvillous processes on the beta cells, which might be early evidence of apoptosis. The diabetes mellitus-like state was not aggravated if the daily injections were continued beyond 5 days. Daily injections of rhIL-1 beta for 2 to 4 weeks induced formation of blocking IL-1 beta...

  12. 反义转化生长因子β1抑制兔耳增生性瘢痕的生物学作用%Biological effect of antisense transforming growth factor beta 1 in inhibiting hyperplastic scar of rabbit's ears

    Institute of Scientific and Technical Information of China (English)

    罗梅; 姬永忠; 汤晓琴

    2006-01-01

    原纤维,但到第6,7周时胶原纤维蓝染变浅并且纤细(宽度为3~5 μm),排列整齐有序.③原位杂交显示转化生长因子β1 mRNA、Ⅰ型胶原mRNA、Ⅲ型胶原mRNA阳性细胞表达率明显降低.结论:反义转化生长因子β1能抑制兔耳增生性瘢痕的增殖过程,使瘢痕组织纤维化程度明显减轻.局部注射裸DNA治疗瘢痕的给药途径是可行的.%BACKGROUND: Nowadays, it is thought that transforming growth factorβ (TGFβ) is closely related with cicatrization. TGFβ that is a key active molecule can affect each phase of cicatrization. Theoretically, to inhibit the biological effect of TGF β can reduce cicatrization.OBJECTIVE: To explore the inhibitive effect of antisense TGF β1 deoxy-oligonucleotide on generation of cicatricle in intention of animal models with hyperplastic scars and observe the effective route of administration of using antisense TGF β1.DESIGN: Own control and animal study.SETTING: Department of Plastic Surgery, Anning Hospital of General Hospital, Lanzhou Military Area Command of Chinese PLAMATERIALS: The experiment was performed at the laboratory of anatomy,Lanzhou Medical College from September 2002 to July 2003. Totally 20flap-eared Japanese rabbits were selected.METHODS: Blood vessels could be seen in ventral surface of each rabbits' ear getting out of the way along long axis to establish two 1.0 cm×2.5 cm oblong full-thickness cutaneous deficiency raw surfaces that interval for 1.5 cm, to the surface of cartilage, totally 80, so asto establish ventral surface of rabbits' ear models with hyperplastic scars. After epithelizatio of raw surfaces of rabbits' ear (20 days, averagely), 5μL(1 g/L) antisense TGF β1 deoxy-oligonucleotide was closely injected into local endepidermis of each raw surface of left ear of each rabbit with microinjector, which was regarded as TGF β1 group. 5 μL saline was injected into each raw surface of right ears, which was regarded as saline control group. After injection for3

  13. Thermal X-ray composites as an effect of projection

    CERN Document Server

    Petruk, O

    2000-01-01

    The new possibility to explain the nature of the thermal X-ray composites as projection effect of 2- or 3-dimensional shell-like supernova remnants (SNRs) evolved in a nonuniform medium is proposed. X-ray and radio morphologies as well as basic theoretical features of such an SNR and surrounding medium are considered. It is shown that the theoretical properties of the shell-like SNR evolved at the edge of molecular cloud with gradient of ambient density along the line of sight correspond to observed properties of the thermal X-ray composites very well. So, at least a part of the objects from the class may be interpreted in the frame of the considered effect.

  14. Late effects of X-ray treatment of warts

    Energy Technology Data Exchange (ETDEWEB)

    Veien, N.K.; Norholm, A.; Hattel, T.; Justesen, O.

    1982-04-01

    Five to 22 years after warts on hands and feet were treated by X ray, 1122 patients with a total of 3675 warts were re-examined. X-Ray therapy had been given as one dose of 3000 r using 29 kV with a 0.3-mm Al filter; 19% of the warts had been given two treatments. Sequelae were seen in 4.8% of the sites where warts had been given one X-ray treatment and in 12.2% of the sites after two treatments. These side effects include hyperkeratosis in the pressure areas of palms and soles and atrophy primarily in areas with a thin cutis. There was no evidence of malignant transformation in any treatment site, and there were no deep-seated side effects such as ostitis or tendinitis.

  15. Transforming growth factor beta 1 prevents cytokine-mediated inhibitory effects and induction of nitric oxide synthase in the RINm5F insulin-containing beta-cell line.

    Science.gov (United States)

    Mabley, J G; Cunningham, J M; John, N; Di Matteo, M A; Green, I C

    1997-12-01

    The aim of this study was to examine if the growth factor, transforming growth factor beta 1 (TGF beta 1), could prevent induction of nitric oxide synthase and cytokine-mediated inhibitory effects in the insulin-containing, clonal beta cell line RINm5F. Treatment of RINm5F cells for 24 h with interleukin-1 beta (IL-1 beta) (100 pM) induced expression of nitric oxide synthase and inhibited glyceraldehyde-stimulated insulin secretion. Combinations of IL-1 beta (100 pM), tumour necrosis factor-alpha (100 pM) and interferon-gamma (100 pM) reduced RINm5F cell viability (determined by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium (MTT) reduction assay) and de novo protein synthesis, as measured by incorporation of radiolabelled amino acids into perchloric acid-precipitable protein. Pretreatment of RINm5F cells with TGF beta 1 (10 pM) for 18 or 24 h, prior to the addition of either IL-1 beta or combined cytokines, prevented cytokine-induced inhibition of insulin secretion, protein synthesis and the loss of cell viability. TGF beta 1 pretreatment inhibited cytokine-induced expression and activity of nitric oxide synthase in RINm5F cells as determined by Western blotting and by cytosolic conversion of radiolabelled arginine into labelled citrulline and nitric oxide. Chemically generated superoxide also induced expression of nitric oxide synthase possibly due to direct activation of the nuclear transcription factor NF kappa B, an effect prevented by both an antioxidant and TGF beta 1 pretreatment. In conclusion, the mechanism of action of TGF beta 1 in blocking cytokine inhibitory effects was by preventing induction of nitric oxide synthase.

  16. Multi-Scale Model of Galactic Cosmic Ray Effects on the Hippocampus

    Science.gov (United States)

    Cucinotta, Francis

    An important concern for risk assessment from galactic cosmic ray (GCR) exposures is impacts to the central nervous systems including changes in cognition, and associations with increased risk of Alzheimer’s disease (AD). AD, which affects about 50 percent of the population above age 80-yr, is a degenerative disease that worsens with time after initial onset leading to death, and has no known cure. AD is difficult to detect at early stages, and the small number of epidemiology studies that have considered the possibility have not identified an association with low dose radiation. However, experimental studies in transgenic mice suggest the possibility exits. We discuss modeling approaches to consider mechanisms whereby GCR would accelerate the occurrence of AD to earlier ages. Biomarkers of AD include Amyloid beta plaques, and neurofibrillary tangles (NFT) made up of aggregates of the hyper-phosphorylated form of the micro-tubule associated, tau protein. Related markers include synaptic degeneration, dendritic spine loss, and neuronal cell loss through apoptosis. GCR may affect these processes by causing oxidative stress, aberrant signaling following DNA damage, and chronic neuro-inflammation. Cell types considered in multi-scale models are neurons, astrocytes, and microglia. We developed biochemical and cell kinetics models of DNA damage signaling related to glycogen synthase kinase-3 beta and neuro-inflammation, and considered approaches to develop computer simulations of GCR induced cell interactions and their relationships to Amyloid beta plaques and NFTs. Comparison of model results to experimental data for the age specific development of plaques in transgenic mice and predictions of space radiation effects will be discussed.

  17. Biological effects of stellar collapse neutrinos

    CERN Document Server

    Collar, J I

    1996-01-01

    Massive stars in their final stages of collapse radiate most of their binding energy in the form of MeV neutrinos. The recoil atoms that they produce in elastic scattering off nuclei in organic tissue create a radiation damage which is highly effective in the production of irreparable DNA harm, leading to cellular mutation, neoplasia and oncogenesis. Using a conventional model of the galaxy and of the collapse mechanism, the periodicity of nearby stellar collapses and the radiation dose are calculated. The possible contribution of this process to the paleontological record of mass extinctions is examined.

  18. Effect of chronic metoprolol and coronary occlusion (CO) on cardiac beta receptor density in cats

    Energy Technology Data Exchange (ETDEWEB)

    Lathers, C.M.; Spivey, W.H.; Levin, R.M.

    1986-03-05

    The effect of metoprolol (M) on beta receptor density (BRD) was examined. M (5 mg/kg, p.o., b.i.d.) was given for 2 and 8 wks prior to CO of the left anterior descending artery (LAD) at its origin. BRD, determined by binding of /sup 3/H-dihydroalprenol, was examined in the myocardium (LA = left atrium, RA = right atrium, LV1 = proximal LAD distribution, LV = 2 distal LAD distribution, LV3 = posterior left ventricle, RV = right ventricle, and S = septum. A 2 factor ANOVA followed by simple effect and Newman-Keuls post hoc tests revealed that M produced no effect in BRD in LA, RA, LV2, or S. M increased BRD in LV1, LV3, and RV after 2 wk when compared to no M. In addition, BRD in LV3 and RV were also greater at 2 wk than after 8 wk M. The data indicate that there are regional differences in the beta adrenergic receptor densities among the areas of the heart and within the left ventricle. Chronic dosing with M produced increased BRD in only some of the areas of the heart. These differences may be related to functional differences in the various areas of the heart after CO.

  19. Beta-ecdysone has bone protective but no estrogenic effects in ovariectomized rats.

    Science.gov (United States)

    Seidlova-Wuttke, Dana; Christel, David; Kapur, Priya; Nguyen, Ba Tiep; Jarry, Hubertus; Wuttke, Wolfgang

    2010-09-01

    Estrogens exert beneficial effects in the bone. Their chronic use however bares several risks. Therefore intensive search for non-estrogenic, bone protective compounds is going on. We observed that an extract of Tinospora cordifolia has antiosteoporotic effects and identified 20-OH-Ecdysone (beta-Ecdysone=Ecd) as a possible candidate for this action. Ovariectomized (ovx) rats were treated orally over 3 months with no Ecd (control) or 18, 57 or 121 mg Ecd/day/animal. Estradiol-17beta benzoate (E2) 159 microg/day/animal) fed animals served as positive controls. Bone mineral density (BMD) of tibia was measured by quantitative computer tomography, serum Osteocalcin and CrossLaps were measured in a ligand binding assay. Utilizing an estrogen receptor (ER) containing cytosolic extract of porcine uteri the capability of Ecd to bind to ER was tested. Ecd did not bind to ER. BMD was reduced by more than 50% in the control. In the Ecd animals BMD was dose dependently higher. Serum CrossLaps was lower in the Ecd and E2 group while serum Osteocalcin levels were decreased in the E2 but increased in the Ecd fed animals. Ecd has an antiosteoporotic effect which does not involve activation of ER.

  20. Highly effective recognition of carbohydrates by phenanthroline-based receptors: alpha- versus beta-anomer binding preference.

    Science.gov (United States)

    Mazik, Monika; Hartmann, Andrè; Jones, Peter G

    2009-09-14

    (1)H NMR spectroscopic titrations in competitive and non-competitive media, as well as binding studies in two-phase systems, such as phase transfer of sugars from aqueous into organic solvents and dissolution of solid carbohydrates in apolar media revealed both highly effective recognition of neutral carbohydrates and interesting binding preferences of an acyclic phenanthroline-based receptor 1. Compared to the previously described acyclic receptors, compound 1 displays significantly higher binding affinities, the rare capability to extract sugars from water into non-polar organic solutions and alpha- versus beta-anomer binding preference in the recognition of glycosides, which differs from those observed for other receptor systems. X-ray crystallographic investigations revealed the presence of water molecules in the binding pocket of 1 that are engaged in the formation of hydrogen-bonding motifs similar to those suggested by molecular modelling for the sugar OH groups in the receptor-sugar complexes. The molecular modelling calculations, synthesis, crystal structure and binding properties of 1 are described and compared with those of the previously described receptors.

  1. PED/PEA-15 induces autophagy and mediates TGF-beta1 effect on muscle cell differentiation.

    Science.gov (United States)

    Iovino, S; Oriente, F; Botta, G; Cabaro, S; Iovane, V; Paciello, O; Viggiano, D; Perruolo, G; Formisano, P; Beguinot, F

    2012-07-01

    TGF-beta1 has been shown to induce autophagy in certain cells but whether and how this action is exerted in muscle and whether this activity relates to TGF-beta1 control of muscle cell differentiation remains unknown. Here, we show that expression of the autophagy-promoting protein phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15) progressively declines during L6 and C2C12 skeletal muscle cell differentiation. PED/PEA-15 underwent rapid induction upon TGF-beta1 exposure of L6 and C2C12 myoblasts, accompanied by impaired differentiation into mature myotubes. TGF-beta1 also induced autophagy in the L6 and C2C12 cells through a PP2A/FoxO1-mediated mechanism. Both the TGF-beta1 effect on differentiation and that on autophagy were blocked by specific PED/PEA-15 ShRNAs. Myoblasts stably overexpressing PED/PEA-15 did not differentiate and showed markedly enhanced autophagy. In these same cells, the autophagy inhibitor 3-methyladenine rescued TGF-beta1 effect on both autophagy and myogenesis, indicating that PED/PEA-15 mediates TGF-beta1 effects in muscle. Muscles from transgenic mice overexpressing PED/PEA-15 featured a significant number of atrophic fibers, accompanied by increased light chain 3 (LC3)II to LC3I ratio and reduced PP2A/FoxO1 phosphorylation. Interestingly, these mice showed significantly impaired locomotor activity compared with their non-transgenic littermates. TGF-beta1 causes transcriptional upregulation of the autophagy-promoting gene PED/PEA-15, which in turn is capable to induce atrophic responses in skeletal muscle in vivo.

  2. Effect of resveratrol and beta-sitosterol in combination on reactive oxygen species and prostaglandin release by PC-3 cells.

    Science.gov (United States)

    Awad, Atif B; Burr, Andrew T; Fink, Carol S

    2005-03-01

    The objective of this project was to identify some possible mechanisms by which two common phytochemicals, resveratrol and beta-sitosterol, inhibit the growth of human prostate cancer PC-3 cells. These mechanisms include the effect of the phytochemicals on apoptosis, cell cycle progression, prostaglandin synthesis and the production of reactive oxygen species (ROS). Prostaglandins have been known to play a role in regulating cell growth and apoptosis. PC-3 cells were supplemented with 50 microM resveratrol or 16 microM beta-sitosterol alone or in combination for up to 5 days. Phytochemical supplementation resulted in inhibition in cell growth. beta-Sitosterol was more potent than resveratrol and the combination of the two resulted in greater inhibition than supplementation with either alone. Long-term supplementation with resveratrol or beta-sitosterol elevated basal prostaglandin release but beta-sitosterol was much more potent than resveratrol in this regard. beta-Sitosterol was more effective than resveratrol in inducing apoptosis and the combination had an intermediate effect after 1 day of supplementation. Cells supplemented with resveratrol were arrested at the G1 phase and at the G2/M phase in the case of beta-sitosterol while the combination resulted in cell arrest at the two phases of the cell cycle. beta-Sitosterol increased ROS production while resveratrol decreased ROS production. The combination of the two phytochemicals resulted in an intermediate level of ROS. The observed changes in prostaglandin levels and ROS production by these two phytochemicals may suggest their mediation in the growth inhibition. The reduction in ROS level and increase by resveratrol supplementation in PC-3 cells reflects the antioxidant properties of resveratrol. It was concluded that these phytochemicals may induce the inhibition of tumor growth by stimulating apoptosis and arresting cells at different locations in the cell cycle and the mechanism may involve alterations in

  3. Effect of interleukin-1beta gene functional polymorphism on dorsolateral prefrontal cortex activity in schizophrenic patients.

    Science.gov (United States)

    Papiol, Sergi; Molina, Vicente; Rosa, Araceli; Sanz, Javier; Palomo, Tomás; Fañanás, Lourdes

    2007-12-05

    Hypoactivity of the dorsolateral prefrontal cortex (DLPFC) during cognitive tasks is among the most consistent findings in schizophrenia. The biological factors contributing to this hypofrontality are only partially known. Previous reports have shown the influence of genes mapped to IL-1 cluster (i) in the risk to develop schizophrenia and (ii) on brain morphological abnormalities in these patients. Moreover, Interleukin-1beta (IL-1beta), encoded by IL-1B gene (IL-1 cluster, chromosome 2q13) has a key role in dopaminergic differentiation and dendrite growth in developing cortical neurons. The authors explored the role of a genetic functional polymorphism at IL-1B gene in relation to DLPFC activity. DLPFC (left and right) metabolic activity was measured in a sample of 19 DSM-IV diagnosed schizophrenic patients of Spanish origin using a procedure based on MRI/PET image fusion. During PET studies, subjects performed a contingent Continuous Performance Test aiming to activate DLPFC. Functional promoter polymorphism -511 C/T (rs16944) of IL-1B gene was genotyped in these patients. Those patients who were allele 2 (-511 T) carriers showed a lower metabolic activity in the left DLPFC with respect to patients homozygous for allele 1 (-511 C) (U = 16, z = -2.32, P = 0.02). Our results suggest that hypofrontality reported in some schizophrenic patients might be explained, at least in part, by this functional polymorphism at IL-1B gene. Genetic variants with influence on brain functionality may account for the neurocognitive heterogeneity observed in schizophrenic patients.

  4. Nanosilver – Harmful effects of biological activity

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2014-12-01

    Full Text Available Nanosilver, also identified as colloidal silver, has been known and used for ages to combat diseases or prolong food freshness. It usually occurs in the form of a suspension consisting of particles of size < 100 nm. Due to its specific properties, silver nanoparticles are used in many technologies to produce medical devices, textiles, conductive materials or photovoltaic cells. The growing popularity of nanosilver applications increases the number of people occupationally exposed to this substance. Potential exposure routes for silver nanoparticles are through dermal, oral and inhalation pathways. Silver nanoparticles may be absorbed through the lungs, intestine, and through the skin into circulation and thus may reach such organs as the liver, kidney, spleen, brain, heart and testes. Nanosilver may cause mild eyes and skin irritations. It can also act as a mild skin allergen. Inhalation of silver nanoparticles mainly affects the lungs and liver. It has been demonstrated that silver nanoparticles may be genotoxic to mammalian cells. There are some alarming reports on the adverse effects of silver nanoparticles on reproduction of experimental animals. Exposure to silver nanoparticles may exert a neurotoxic effect and affect cognitive functions, causing the impairment of short-term and working memory. Maximum admissible concentration (MAC for the inhalable fraction of silver of 0.05 mg/m3 is currently binding in Poland. In light of toxicological studies of silver nanoparticles it seems reasonable to update the hygiene standards for silver with nanoparticles as a separate fraction. Med Pr 2014;65(6:831–845

  5. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwoińska, Jolanta; Gremba, Jerzy; Gałdzińska-Calik, Barbara; Wójcik-Piotrowicz, Karolina; Thor, Piotr J

    2015-01-01

    Exposure to artificial radio frequency electromagnetic fields (EMFs) has increased significantly in recent decades. Therefore, there is a growing scientific and social interest in its influence on health, even upon exposure significantly below the applicable standards. The intensity of electromagnetic radiation in human environment is increasing and currently reaches astronomical levels that had never before experienced on our planet. The most influential process of EMF impact on living organisms, is its direct tissue penetration. The current established standards of exposure to EMFs in Poland and in the rest of the world are based on the thermal effect. It is well known that weak EMF could cause all sorts of dramatic non-thermal effects in body cells, tissues and organs. The observed symptoms are hardly to assign to other environmental factors occurring simultaneously in the human environment. Although, there are still ongoing discussions on non-thermal effects of EMF influence, on May 31, 2011--International Agency for Research on Cancer (IARC)--Agenda of World Health Organization (WHO) has classified radio electromagnetic fields, to a category 2B as potentially carcinogenic. Electromagnetic fields can be dangerous not only because of the risk of cancer, but also other health problems, including electromagnetic hypersensitivity (EHS). Electromagnetic hypersensitivity (EHS) is a phenomenon characterized by the appearance of symptoms after exposure of people to electromagnetic fields, generated by EHS is characterized as a syndrome with a broad spectrum of non-specific multiple organ symptoms including both acute and chronic inflammatory processes located mainly in the skin and nervous systems, as well as in respiratory, cardiovascular systems, and musculoskeletal system. WHO does not consider the EHS as a disease-- defined on the basis of medical diagnosis and symptoms associated with any known syndrome. The symptoms may be associated with a single source of EMF

  6. Biological effect of radiation on human

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae [and others

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved.

  7. Effects of finite-{beta} and radial electric fields on neoclassical transport in the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, R.; Nakajima, N.; Sugama, H.; Okamoto, M.; Ogawa, Y.

    1997-01-01

    Effects of finite-{beta} and radial electric fields on the neoclassical transport in the Large Helical Device are investigated with the DKES (Drift Kinetic Equation Solver) code. In the finite-{beta} configuration, even orbits of deeply trapped particles deviate significantly from magnetic flux surfaces. Thus, neoclassical ripple transport coefficients in the finite-{beta} configuration are several times larger than those in the vacuum configuration under the same condition of temperatures and radial electric fields. When the plasma temperature is several keV, a bifurcation of the electric fields appears under the ambipolarity condition, and sufficient large radial electric fields can be generated. As a result, the ExB drift rectifies orbits of particles and improves significantly the transport coefficients in the finite-{beta} configuration. (author)

  8. Marked effect of beta-lactoglobulin polymorphism on the ratio of casein to total protein in milk.

    Science.gov (United States)

    Lundén, A; Nilsson, M; Janson, L

    1997-11-01

    The relationship between genetic variants for milk protein and the composition of milk was analyzed on 4475 repeated milk samples from individual cows; 371 dairy cows of the Swedish Red and White breed and 204 cows of the Swedish Holstein breed were used. The registrations included percentages of casein, protein, fat, and lactose in combination with milk yield and SCC. The genotype of individual cows for alpha(s1)-CN, beta-CN, kappa-CN, and beta-LG was determined by alkaline and acidic PAGE. A mixed animal model was used for the analysis; beta-LG and aggregate casein genotypes were included simultaneously as separate fixed effects in the statistical model. The results suggest a positive additive effect of the beta-LG B allele on casein content and on the ratio of casein to total protein. For the latter trait, the beta-LG genotype accounted for a relatively large part of the phenotypic variance, corresponding to a reduction in residual variance of 11% when included in the model. The corresponding value for casein content was 0.5%. The lack of unfavorable associations between milk protein variants and the traits included in this study makes the beta-LG gene an obvious candidate when the breeding objective is improved conversion of milk protein into cheese.

  9. Protective effect of niacinamide on interleukin-1beta-induced annulus fibrosus type II collagen degeneration in vitro.

    Science.gov (United States)

    Duan, Deyu; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiong, Xiaoqian

    2007-02-01

    The protective effect of niacinamide on interleukin-1beta (IL-1beta)-induced annulus fibrosus (AF) type II collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebral disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type II collagen degneration group (IL-1beta) and treatment group (niacinamide+IL-1beta). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type II collagen immunohistochemical examination, and type II collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type II collagen degeneration group (Pniacinamide could effectively inhibit IL-1beta stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1beta-caused destruction and synthesis inhibition of type II collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  10. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  11. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  12. The effects of beta-blockers on dobutamine-atropine stress echocardiography: early protocol versus standard protocol

    Directory of Open Access Journals (Sweden)

    Weitzel Luis H

    2006-07-01

    Full Text Available Abstract Background To study the effects of Beta-blockers during Dobutamine Stress Echocardiography (DSE comparing the hemodynamic benefits of an early administration of atropine in patients taking or not Beta-blockers. Methods One hundred and twenty-one patients were submitted to dobutamine stress echocardiography for the investigation of myocardial ischemia. The administration of atropine was randomized into two groups: A or B (early protocol when atropine was administered at 10 and 20 mcg/kg/min of dobutamine, respectively and C (standard protocol with atropine at 40 mcg/kg/min of dobutamine. Analysis of the effects of Beta-blockers was done regarding the behavior pattern of heart rate and blood pressure, test time, number of conclusive and inconclusive (negative sub-maximum test results, total doses of atropine and dobutamine, and general complications. Results Beta-blocked patients who received early atropine (Group A&B had a significantly lower double product (p = 0.008, a higher mean test time (p = 0.010 and required a higher dose of atropine (p = 0.0005 when compared to the patients in this group who were not Beta-blocked. The same findings occurred in the standard protocol (Group C, however the early administration of atropine reduced test time both in the presence and absence of this therapy (p = 0.0001. The patients with Beta-blockers in Group A&B had a lower rate of inconclusive tests (26% compared to those in Group C (40%. Complications were similar in both groups. Conclusion The chronotropic response during dobutamine stress echocardiography was significantly reduced with the use of Beta-blockers. The early administration of atropine optimized the hemodynamic response, reduced test time in patients with or without Beta-blockers and reduced the number of inconclusive tests in the early protocol.

  13. Effect of sterilization on the properties of CDHA-OCP-beta-TCP biomaterial

    Directory of Open Access Journals (Sweden)

    Loreley Morejón-Alonso

    2007-03-01

    Full Text Available The effect of the method of sterilization on the physical, chemical and mechanical properties of a new bone repairing material was studied. The material was obtained by thermal hydrolysis of beta-tricalcium phosphate/orthophosphoric acid cement and was composed of calcium deficient hydroxyapatite, octacalcium phosphate (OCP, and beta-tricalcium phosphate. Partial decomposition of the OCP was observed after sterilization for the three methods. Decomposition increased to the following sequence of sterilization methods: ethylene oxide; autoclaving; dry oven. On the other hand, mechanical strength decreased with regard to non sterilized material in the sterilization sequence: ethylene oxide; dry oven; autoclaving. The compressive strength was 8.5 ± 1.0; 9.0 ± 1.2; 8.2 ± 0.8 and 6.5 ± 1.0 MPa, whereas diametral tensile strength was 2.1 ± 0.3; 2.5 ± 0.1; 1.9 ± 0.9 and 1.6 ± 0.3 for the material sterilized by ethylene oxide, dry oven, and autoclaving, respectively. Several compositional and microstuctural changes were detected after dry heat and autoclave sterilization. Ethylene oxide sterilization had lesser effect on the chemical composition and strength than dry heat and autoclaving.

  14. High-resolution metallic magnetic calorimeters for {beta}-spectroscopy on {sup 187}rhenium and position resolved X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Porst, Jan-Patrick

    2011-02-01

    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for {beta}-endpoint spectroscopy on {sup 187}rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 {mu}s could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than {delta}E{sub FWHM}<5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

  15. Thermodynamic Effect of Platinum Addition to beta-NiAl: An Initial Investigation

    Science.gov (United States)

    2005-01-01

    An initial investigation was conducted to determine the effect of platinum addition on the activities of aluminum and nickel in beta-NiAl(Pt) over the temperature range 1354 to 1692 K. These measurements were made with a multiple effusion-cell configured mass spectrometer (multi-cell KEMS). The results of this study show that Pt additions act to decreased alpha(Al) and increased the alpha(Ni) in beta-NiAl(Pt) for constant X(sub Ni)/X(sub Al) approx. = 1.13, while at constant X(sub Al) the affect of Pt on Al is greatly reduced. The measured partial enthalpies of mixing indicate Al-atoms have a strong self interaction while Ni- and Pt-atoms in have similar interactions with Al-atoms. Conversely the binding of Ni-atoms in beta-NiAl decreases with Pt addition independent of Al concentration. These initial results prove the technique can be applied to the Ni-Al-Pt system but more activity measurements are required to fully understand the thermodynamics of this system and how Pt additions improved the scaling behavior of nickel-based superalloys. In addition, with the choice of a suitable oxide material for the effusion-cell, the "closed" isothermal nature of the effusion-cell allows the direct investigation of an alloy-oxide equilibrium which resembles the "local-equilibrium" description of the metal-scale interface observed during high temperature oxidation. It is proposed that with an Al(l) + Al2O3(s) experimental reference state together with the route measurement of the relative partial-pressures of Al(g) and Al2O(g) allows the activities of O and Al2O3 to be determined along with the activities of Ni and Al. These measurements provide a direct method of investigating the thermodynamics of the metal-scale interface of a TGO-scale.

  16. Cosmic rays and space weather: effects on global climate change

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2012-01-01

    Full Text Available We consider possible effects of cosmic rays and some other space factors on the Earth's climate change. It is well known that the system of internal and external factors formatting the climate is very unstable; decreasing planetary temperature leads to an increase of snow surface, and decrease of the total solar energy input into the system decreases the planetary temperature even more, etc. From this it follows that even energetically small factors may have a big influence on climate change. In our opinion, the most important of these factors are cosmic rays and cosmic dust through their influence on clouds, and thus, on climate.

  17. Third eye, the biological effects; 3. oeil, les effets biologiques

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-02-01

    The discovery of a third kind of photo-receptor cell in the human eye has permitted to better understand the biological effects of lighting, not only on the vision, but also on some nervous processes, like emotion, mood, stress, biological clock, etc.. This additional dimension has led the engineers of Philips Lighting company to launch a new indoor lighting concept named 'Carpe Diem'. This concept adapts both the illuminance and the color of a lighting system according to the type of work and to the expected stimulating effect. (J.S.)

  18. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  19. Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

    Directory of Open Access Journals (Sweden)

    Hess Rex A

    2006-10-01

    Full Text Available Abstract Background Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol, once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. Methods To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. Results Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. Conclusion This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has

  20. Towards an integrative structural biology approach: combining Cryo-TEM, X-ray crystallography, and NMR.

    Science.gov (United States)

    Lengyel, Jeffrey; Hnath, Eric; Storms, Marc; Wohlfarth, Thomas

    2014-09-01

    Cryo-transmission electron microscopy (Cryo-TEM) and particularly single particle analysis is rapidly becoming the premier method for determining the three-dimensional structure of protein complexes, and viruses. In the last several years there have been dramatic technological improvements in Cryo-TEM, such as advancements in automation and use of improved detectors, as well as improved image processing techniques. While Cryo-TEM was once thought of as a low resolution structural technique, the method is currently capable of generating nearly atomic resolution structures on a routine basis. Moreover, the combination of Cryo-TEM and other methods such as X-ray crystallography, nuclear magnetic resonance spectroscopy, and molecular dynamics modeling are allowing researchers to address scientific questions previously thought intractable. Future technological developments are widely believed to further enhance the method and it is not inconceivable that Cryo-TEM could become as routine as X-ray crystallography for protein structure determination.

  1. Spatial genetic structure in Beta vulgaris subsp. maritima and Beta macrocarpa reveals the effect of contrasting mating system, influence of marine currents, and footprints of postglacial recolonization routes.

    Science.gov (United States)

    Leys, Marie; Petit, Eric J; El-Bahloul, Yasmina; Liso, Camille; Fournet, Sylvain; Arnaud, Jean-François

    2014-05-01

    Understanding the factors that contribute to population genetic divergence across a species' range is a long-standing goal in evolutionary biology and ecological genetics. We examined the relative importance of historical and ecological features in shaping the present-day spatial patterns of genetic structure in two related plant species, Beta vulgaris subsp. maritima and Beta macrocarpa. Using nuclear and mitochondrial markers, we surveyed 93 populations from Brittany (France) to Morocco - the southern limit of their species' range distribution. Whereas B. macrocarpa showed a genotypic structure and a high level of genetic differentiation indicative of selfing, the population genetic structure of B. vulgaris subsp. maritima was consistent with an outcrossing mating system. We further showed (1) a strong geographic clustering in coastal B. vulgaris subsp. maritima populations that highlighted the influence of marine currents in shaping different lineages and (2) a peculiar genetic structure of inland B. vulgaris subsp. maritima populations that could indicate the admixture of distinct evolutionary lineages and recent expansions associated with anthropogenic disturbances. Spatial patterns of nuclear diversity and differentiation also supported a stepwise recolonization of Europe from Atlantic-Mediterranean refugia after the last glacial period, with leading-edge expansions. However, cytoplasmic diversity was not impacted by postglacial recolonization: stochastic long-distance seed dispersal mediated by major oceanic currents may mitigate the common patterns of reduced cytoplasmic diversity observed for edge populations. Overall, the patterns we documented here challenge the general view of reduced genetic diversity at the edge of a species' range distribution and provide clues for understanding how life-history and major geographic features interact to shape the distribution of genetic diversity.

  2. Status and Performance of New Silicon Stripixel Detector for the PHENIX Experiment at RHIC Beta Source, Cosmic-rays and Proton Beam at 120 GeV

    CERN Document Server

    Nouicer, Rachid

    2009-01-01

    We are constructing a Silicon Vertex Tracker detector (VTX) for the PHENIX experiment at RHIC. Our main motivation is to enable measurements of heavy flavor production (charm and beauty) in p+p, p+d and A+A collisions. Such data will illuminate the properties of the matter created in high-energy heavy-ion collisions. The measurements also will reveal the distribution of gluons in protons from p+p collisions. The VTX detector consists of four layers of barrel detectors and covers |eta|< 1.2, and almost a 2pi in azimuth. The inner two silicon barrels consist of silicon pixel sensors; their technology accords with that of the ALICE1LHCB sensor-readout hybrid. The outer two barrels are silicon stripixel detectors with a new "spiral" design, and a single-sided sensor with 2-dimensional (X, U) readout. In this paper, we describe the silicon stripixel detector and discuss its performance, including its response to electrons from a beta source (90Sr), muons from cosmic-rays, and a 120 GeV proton beam. The results ...

  3. A bench-top K X-ray fluorescence system for quantitative measurement of gold nanoparticles for biological sample diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, K., E-mail: k.ricketts@ucl.ac.uk [Division of Surgery and Interventional Sciences, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF (United Kingdom); Guazzoni, C.; Castoldi, A. [Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano and INFN, Sezione di Milano P.za Leonardo da Vinci, 32-20133 Milano (Italy); Royle, G. [Department of Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WC1E 6BT (United Kingdom)

    2016-04-21

    Gold nanoparticles can be targeted to biomarkers to give functional information on a range of tumour characteristics. X-ray fluorescence (XRF) techniques offer potential quantitative measurement of the distribution of such heavy metal nanoparticles. Biologists are developing 3D tissue engineered cellular models on the centimetre scale to optimise targeting techniques of nanoparticles to a range of tumour characteristics. Here we present a high energy bench-top K-X-ray fluorescence system designed for sensitivity to bulk measurement of gold nanoparticle concentration for intended use in such thick biological samples. Previous work has demonstrated use of a L-XRF system in measuring gold concentrations but being a low energy technique it is restricted to thin samples or superficial tumours. The presented system comprised a high purity germanium detector and filtered tungsten X-ray source, capable of quantitative measurement of gold nanoparticle concentration of thicker samples. The developed system achieved a measured detection limit of between 0.2 and 0.6 mgAu/ml, meeting specifications of biologists and being approximately one order of magnitude better than the detection limit of alternative K-XRF nanoparticle detection techniques. The scatter-corrected K-XRF signal of gold was linear with GNP concentrations down to the detection limit, thus demonstrating potential in GNP concentration quantification. The K-XRF system demonstrated between 5 and 9 times less sensitivity than a previous L-XRF bench-top system, due to a fundamental limitation of lower photoelectric interaction probabilities at higher K-edge energies. Importantly, the K-XRF technique is however less affected by overlying thickness, and so offers future potential in interrogating thick biological samples.

  4. Small angle X-ray and neutron scattering from solutions of biological macromolecules

    CERN Document Server

    Svergun, Dmitri I; May, Roland P; Timmins, Peter A

    2013-01-01

    In this book, following the presentation of the basics of scattering from isotropic macromolecular solutions, modern instrumentation, experimental practice and advanced analysis techniques are explained. Advantages of X-rays (rapid data collection, small sample volumes) and of neutrons (contrast variation by hydrogen/deuterium exchange) are specifically highlighted. Examples of applications of the technique to different macromolecular systems are considered with specific emphasis on the synergistic use of SAXS/SANS with other structural, biophysical and computational techniques.

  5. [Long-term effects of combined therapy in patients with beta-thalassemia major].

    Science.gov (United States)

    Bagnulo, S; Giannini, A M; Moscatelli, F; Stragapede, L; Acquafredda, A; Dammacco, A

    1998-01-01

    We evaluated therapy complications in 19 beta-thalassemia major patients (mean age from 3 years/5 months and 1 years/6 months) who were followed at II Pediatric Department-University of Bari. 3 out of 19 patients underwent allogenic BMT from matched related donor; 2 out of 19 underwent splenectomy. All of them were receiving hypertransfusion therapy and continuous chelation with DFO. In all patients we performed physical examination, laboratory assays, cardiac and endocrinologic function tests, serum HBV-HCV-HIV antibodies, otoscopy and audiometric test, fundus oculi, skeletal x-ray. 1 out of 19 patients, who was under 15, had a slight dilatation of left ventricle and arythmia. All patients were HBsAb positive. 4/19 patients were HCV Ab positive (ELISA test) with an increase in ALT-AST serum levels since at least 6 months. In 3 of them we assessed RIBA test, always positive. 3 of them underwent liver biopsy (1 iron overload 2 chronic active hepatitis). All patients were HIV Ab negative. 4/15 patients revealed low GH levels after Arginina test. 13 pre-pubescent patients had normal results with GNRH test but lower results after FSH test. 1 pubescent patient had gonadotropic hypophyseal deficit. 4 patients had subclinic hypothiroidism. We couldn't find any sequelas in bone-eyes-ears. Hypertransfusion therapy, chelation, profilaxis of infections improved length and quality of life in thalassemic patients. Hypogonadotropic hypogonadism remains a serious sequela and we think it needs to be treated.

  6. Effect of water on self-assembled tubules in {beta}-sitosterol + {gamma}-oryzanol-based organogels

    Energy Technology Data Exchange (ETDEWEB)

    Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen, E-mail: ruud-den.adel@unilever.co [Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, NL-3133 AT Vlaardingen (Netherlands)

    2010-10-01

    Mixtures of {beta}-sitosterol and {gamma}-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. {beta}-Sitosterol and {gamma}-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of {beta}-sitosterol + {gamma}-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of {beta}-sitosterol + {gamma}-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2{+-}0.1 nm, wall thickness 0.8{+-}0.2 nm).

  7. Plasma effects in electromagnetic field interaction with biological tissue

    Science.gov (United States)

    Sharma, R. P.; Batra, Karuna; Excell, Peter S.

    2011-02-01

    Theoretical analysis is presented of the nonlinear behavior of charge carriers in biological tissue under the influence of varying low-intensity electromagnetic (EM) field. The interaction occurs because of the nonlinear force arising due to the gradient of the EM field intensity acting on free electrons in the conduction band of proteins in metabolically active biological cell membrane receptors leading to a redistribution of charge carriers. Field dependence of the resulting dielectric constant is investigated by a suitable modification to include an additional electronic contribution term to the three-term Debye model. The exogenous EM field propagating in this nonlinear cellular medium satisfies the nonlinear Schrödinger equation and can be affected significantly. Resulting field effect can be substantially augmented and effective rectification/demodulation can occur. Possible implications of this modification on biological processes in white and grey matter are discussed.

  8. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Yuki; Nakasako, Masayoshi [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Kanagawa 223-8522 (Japan); RIKEN Harima Institute/SPring-8, 1-1-1 Kouto, Mikaduki, Sayo, Hyogo 679-5148 (Japan)

    2012-05-15

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  9. Few active mechanisms of the neutrinoless double beta-decay and effective mass of Majorana neutrinos

    CERN Document Server

    Simkovic, Fedor; Faessler, Amand

    2010-01-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay (0nbb-decay). By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, assuming the observation of the 0nbb-decay in three different nuclei, e.g., 76Ge, 100Mo and 130Te, and just three lepton number violating mechanisms (light and heavy neutrino mass mechanisms as well as R-parity breaking SUSY mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, assuming evidence of the 0nbb-decay of 76Ge, the effective neutrino Majorana mass |m_bb| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium beta-decay ex...

  10. Effects of cytostatic drugs on plasma level and renal excretion of beta-acetyldigoxin.

    Science.gov (United States)

    Kuhlmann, J; Zilly, W; Wilke, J

    1981-10-01

    Mucosal defects decrease digoxin absorption in patients with malabsorption syndromes. Since the intestinal mucosa can be damaged by cytostatic drugs, we investigated their effects on digoxin plasma levels and urinary digoxin excretion. In six patients with malignant lymphoma who received 0.8 mg beta-acetyldigoxin before and 24 hr after treatment with a combination of cyclophosphamide, oncovin, procarbazine, and prednisone (COPP) or cyclophosphamide, oncovin, and prednisone (COP), plasma digoxin concentrations were measured 0 to 8 hr after the dose and areas under the plasma concentration-time curves were calculated. In 15 patients on 0.3 mg of beta-acetyldigoxin daily, plasma glycoside concentrations and renal excretion were measured daily before and after COPP, COP, cyclophosphamide, oncovin, cytosine-arabinosine, and prednisone (COAP), or adriamycin, bleomycin, and prednisone (ABP) treatment schemes. The diminished steady-state glycoside plasma concentrations and daily renal glycoside excretion during the 24 to 168 hr after the cytostatic drug established reversible impairment of digoxin absorption. The delayed time to peak after a single dose of digoxin during cytostatic drug therapy shows that extent and rate of digoxin absorption are reduced. To maintain adequate control of digoxin therapy in patients treated with cytostatic drugs, plasma levels should be monitored.

  11. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints

    Science.gov (United States)

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B.; George, Kerry A.; Cucinotta, Francis A.

    2016-01-01

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE’s using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE’s are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE’s against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed. PMID:27111667

  12. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints.

    Directory of Open Access Journals (Sweden)

    Eliedonna Cacao

    Full Text Available The biological effects of high charge and energy (HZE particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE's using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE's are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10 are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE's against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed.

  13. Does TGF Beta Suppressing Effect of Simvastatin Lead to Protection Against Surgical Adhesion Band Formation?

    Directory of Open Access Journals (Sweden)

    Sayed Shahabuddin Hoseini

    2008-05-01

    Full Text Available Intra-abdominal adhesions are the most common cause of small bowel obstruction. Infertility in women and chronic abdominal-pelvic pain are the other problems of adhesiogenesis which impose a great economic burden on the population health. On the other hand, increased levels of transforming growth factor beta1 (TGF-β are shown to play a role in formation of adhesion bands and can impair peritoneal fibrinolysis. Moreover, simvastatin, an immunomodulator agent, can down-regulate TGF-β. Although it is shown in previous studies that simvastatin antagonizes the interaction between TGF-β and connective tissue growth factor (CTGF, no human study exists on the effect of simvastatin on surgical adhesion band formation. We hypothesize that simvastatin, through its effect on reducing the level of TGF-β, may be useful in preventing adhesion band formation after surgical procedures. Surely, this hypothesis should be assessed in several experimental and clinical trials.

  14. Quantification of Randomly-methylated-{beta}-cyclodextrin effect on liposome: An ESR study

    Energy Technology Data Exchange (ETDEWEB)

    Grammenos, A., E-mail: A.Grammenos@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, Institute of Physics, B5, University of Liege, Sart-Tilman, B-4000 Liege (Belgium); Bahri, M.A.; Guelluy, P.H. [Laboratory of Biomedical Spectroscopy, Department of Physics, Institute of Physics, B5, University of Liege, Sart-Tilman, B-4000 Liege (Belgium); Piel, G. [Laboratory of Pharmaceutical Technology, Department of Pharmacy, CHU, B36, University of Liege, 1 Av. de l' Hopital, B-4000 Liege (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, Institute of Physics, B5, University of Liege, Sart-Tilman, B-4000 Liege (Belgium)

    2009-12-04

    In the present work, the effect of Randomly-methylated-{beta}-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-{alpha} phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance (ESR) technique. The ability of Rameb to extract membrane cholesterol was demonstrated. For the first time, the percentage of cholesterol extracted by Rameb from cholesterol doped DMPC bilayer was monitored and quantified throughout a wide Rameb concentration range. The effect of cholesterol on the inner part of the membrane was also investigated using 16-doxyl stearic acid spin label (16-DSA). 16-DSA seems to explore two different membrane domains and report their respective microviscosities. ESR experiments also establish that the presence of 30% of cholesterol in DMPC liposomes suppresses the jump in membrane fluidity at lipids phase-transition temperature (23.9 {sup o}C).

  15. Experimental studies of the early effects of inhaled beta-emitting radionuclides for nuclear accident risk assessment: Phase 2 report

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Hahn, F.F.; Newton, G.J.; Snipes, M.B.; Damon, E.G.; Mauderly, J.L.; Boecker, B.B.; Gray, D.H.

    1987-11-01

    This report summarizes a series of experiments concerning the effect of linear energy transfer and temporal radiation dose pattern to the lung from inhaled beta-emitting radionuclides. The results were used to test the validity of a hazard-function mathematical model for predicting death from radiation pneumonitis. Both morbidity and mortality within 18 months after exposure were examined in rats exposed to beta-emitting radionuclides, giving brief or protracted irradiation of the lung or having weak or strong beta emissions. Protraction of the radiation dose to the lung from a half-time in the lung of less than three days to a half-time with a long-term component of about 150 days has a sparing effect. The median lethal dose for the protracted irradiation is about 1.7 times the median lethal dose for the brief irradiation. Low energy beta emissions from /sup 147/Pm have a similar effectiveness in producing lethal injury as high energy beta emissions from /sup 90/Sr. Changes in three parameters of morbidity were measured: body weight, hematology and pulmonary function; only changes in pulmonary function correlated well with pulmonary radiation injury. The doses of radiation required to produce impaired function, however, were not significantly different from those that produced death. The hazard-function model for predicting death from radiation pneumonitis, which was developed from previously obtained data for inhalation exposures of dogs to beta-emitting radionuclides, adequately predicted the median lethal doses for rats receiving one of several different beta dose rate patterns to the lung, thus strengthening the validity of the mathematical model. 23 refs., 41 figs., 12 tabs.

  16. Synthesis and biological screening of a combinatorial library of beta-chlorovinyl chalcones as anticancer, anti-inflammatory and antimicrobial agents.

    Science.gov (United States)

    Bandgar, Babasaheb P; Gawande, Shrikant S

    2010-03-01

    A combinatorial library of beta-chlorovinyl chalcones (4) were synthesized by Claisen-Schmidt condensation reaction. Catalytic reaction of substituted 3-chloro-3-phenyl-propenal (2) and 1-(2,4-dimethoxy-phenyl)-ethanone or 1-(4-methoxy-phenyl)-ethanone (3) in alkaline conditions furnished the target compound 5-chloro-1-(2,4-dimethoxy-phenyl)-5-phenyl-penta-2,4-dien-1-one (4). The synthesized compounds were screened for their biological activity viz. anticancer, anti-inflammatory and antimicrobial activities. Synthesized compounds 4g and 4h revealed promising anti-inflammatory activity (66-67% TNF-alpha and 95-97% IL-6 inhibitory activity at 10 microM). Cytotoxicity of the compounds checked using CCK-8 cell lines and found to be nontoxic to slightly toxic. Furthermore, the anticancer activity (30-40%) was shown by compounds 4d, 4e, 4h and 4b at 10 microM concentrations against ACHN followed by Calu 1, Panc1, HCT116 and H460 cell lines. Some of the compounds 4d, 4e, 4a, 4i and 4b revealed promising antimicrobial activity at MIC 50-100 microg/mL against selected pathogenic bacteria and fungi.

  17. Industrial Catalysis%Effects of beta nucleating agent on mechanical properties of polypropylene

    Institute of Scientific and Technical Information of China (English)

    马丽; 王文燕; 张怀志; 侯雅丽

    2016-01-01

    通过在抗冲聚丙烯基础树脂中添加自主研制的酰胺型高效β成核剂,在升高聚丙烯耐热温度的同时有效提高聚丙烯树脂EPS30 R的冲击强度,研究酰胺型β成核剂PA-01、TMB-5和FB-1添加量对聚丙烯树脂EPS30 R力学性能的影响,通过微观形态分析增韧的内在原因,并考察成核剂对聚丙烯树脂EPS30 R的成核效果。结果表明,添加β成核剂后,聚丙烯的力学性能明显改善,且β成核剂诱导聚丙烯的成核效果较好。%By adding self-developed high-efficiency amide β nucleating agents into impact polypropylene base resin,the heat resistance temperature of polypropylene was improved and meanwhile the impact strength of polypropylene resin EPS30R was also effectively improved. The effects of the amounts of amideβnucleating agents PA-01 ,TMB-5 and FB-1 on the mechanical properties of polypropylene resin EPS30 R were researched by microscopic morphological analysis of toughening internal causes. The influence of nucleating agent on nucleating effect of polypropylene resin EPS30R was also investigated. The results showed that after adding beta nucleating agent,the mechanical properties of polypropylene were improved obviously,and nucleating effect of polypropylene induced by beta nucleating agent was better.

  18. Effect of polymorphic variants of GH, Pit-1, and beta-LG genes on milk production of Holstein cows.

    Science.gov (United States)

    Heidari, M; Azari, M A; Hasani, S; Khanahmadi, A; Zerehdaran, S

    2012-04-01

    Effect of polymorphic variants of growth hormone (GH), beta-lactoglobulin (beta-LG), and Pit-1 genes on milk yield was analyzed in a Holstein herd. Genotypes of the cows for these genes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Allele frequencies were 0.884 and 0.116 for L and V variants of GH, 0.170 and 0.830 for A and B variants of Pit-1, and 0.529 and 0.471 for A and B variants of beta-LG, respectively. GLM procedure of SAS software was used to test the effects of these genes on milk yield. Results indicated significant effects of these genes on milk yield (P LG gene, milk yield of animals with AA genotype was more than BB genotype (P LG (AA) were superior compared to heterozygote genotypes, whereas, the heterozygote genotype of Pit-1 gene (AB) was desirable.

  19. Antiremodeling effects on the left ventricle during beta-blockade with metoprolol in the treatment of chronic heart failure

    DEFF Research Database (Denmark)

    Grønning, Bjørn Aaris; Nilsson, J C; Sondergaard, Lars

    2000-01-01

    index remained unchanged, whereas LV mass index decreased in both groups (175 g/m2 to 160 g/m2 in the placebo group [p = 0.005] and 179 g/m2 to 164 g/m2 in the metoprolol CR/XL group [p = 0.011). CONCLUSIONS: This study is the first randomized study to demonstrate that the beta1-blocker metoprolol CR......OBJECTIVES: The purpose of the study was to investigate the effects of beta1-blockade on left ventricular (LV) size and function for patients with chronic heart failure. BACKGROUND: Large-scale trials have shown that a marked decrease in mortality can be obtained by treatment of chronic heart...... failure with beta-adrenergic blocking agents. Possible mechanisms behind this effect remain yet to be fully elucidated, and previous studies have presented insignificant results regarding suspected LV antiremodeling effects. METHODS: In this randomized, placebo-controlled and double-blind substudy...

  20. Challenges in Analyzing the Biological Effects of Resveratrol

    DEFF Research Database (Denmark)

    Erdogan, Cihan Süleyman; Vang, Ole

    2016-01-01

    The suggested health effects (e.g., disease prevention) of dietary bioactive compounds such as resveratrol are challenging to prove in comparison to man-made drugs developed for therapeutic purposes. Dietary bioactive compounds have multiple cellular targets and therefore have a variety of biolog...

  1. Computer Simulations to Study Diffraction Effects of Stacking Faults in Beta-SiC: II. Experimental Verification. 2; Experimental Verification

    Science.gov (United States)

    Pujar, Vijay V.; Cawley, James D.; Levine, S. (Technical Monitor)

    2000-01-01

    Earlier results from computer simulation studies suggest a correlation between the spatial distribution of stacking errors in the Beta-SiC structure and features observed in X-ray diffraction patterns of the material. Reported here are experimental results obtained from two types of nominally Beta-SiC specimens, which yield distinct XRD data. These samples were analyzed using high resolution transmission electron microscopy (HRTEM) and the stacking error distribution was directly determined. The HRTEM results compare well to those deduced by matching the XRD data with simulated spectra, confirming the hypothesis that the XRD data is indicative not only of the presence and density of stacking errors, but also that it can yield information regarding their distribution. In addition, the stacking error population in both specimens is related to their synthesis conditions and it appears that it is similar to the relation developed by others to explain the formation of the corresponding polytypes.

  2. Biological Effect of Ultraviolet Photocatalysis on Nanoscale Titanium with a Focus on Physicochemical Mechanism.

    Science.gov (United States)

    Wu, Jingyi; Zhou, Lei; Ding, Xianglong; Gao, Yan; Liu, Xiangning

    2015-09-15

    Physicochemical properties, regulated by various surface modifications, influence the biological performance of materials. The interaction between surface charge and biomolecules is key to understanding the mechanism of surface-tissue integration. The objective of this study was to evaluate the biological response to a nanoscale titanium surface after ultraviolet (UVC, λ = 250 ± 20 nm) irradiation and to analyze the effects via a physicochemical mechanism. The surface characteristics were evaluated by field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, surface profilometry, and contact angle assay. In addition, we applied the zeta-potential, a direct method to measure the electrostatic charge on UV-treated and UV-untreated titanium nanotube surfaces. The effect of the Ti surface after UV treatment on the biological process was determined by analyzing bovine serum albumin (BSA) adsorption and osteoblast-like MG-63 early adhesion, morphology, cytoskeletal arrangement, proliferation, and focal adhesion. Compared to an anodized titanium nanotube coating, UV irradiation altered the contact angles on the control surface from 51.5° to 6.2° without changing the surface topography or roughness. Furthermore, titanium nanotubes after UV treatment showed a significant reduction in the content of acidic hydroxyl groups and held less negative charge than the anodized coating. With regard to the biological response, along with an enhanced capability to adsorb BSA, osteoblasts exhibited higher colonization and viability on the UV-treated material. The results suggest that UV treatment enhances the biocompatibility by reducing the electrostatic repulsion between biomaterials and biomolecules.

  3. Adaptation hypothesis of biological effectiveness of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kudritsky, Yu.K.; Georgievsky, A.B.; Karpov, V.I.

    1993-12-31

    The adoptation hypothesis of biological effectiveness of ionizing radiations is based on the recognition of the invariability of general biological laws for radiobiology and on the comprehension of life evolution regularities and axiomatic principles of environment and biota unity. The ionizing radiation factor is essential for life which could not exist beyond the radiation field. The possibility of future development of the adaptation hypothesis serves as a basis for it`s transformation into the theoretical foundation of radiobiology. This report discusses the aspects of the adaptation theory.

  4. Effects of beetroot (Beta vulgaris) preparations on the Maillard reaction products in milk and meat-protein model systems

    NARCIS (Netherlands)

    Rackauskienea, I.; Pukalskas, A.; Rimantas Venskutonis, P.; Fiore, A.M.; Troise, A.D.; Fogliano, V.

    2015-01-01

    The effects of beetroots (Beta vulgaris) on the formation of Maillard reaction (MR) products possessing health, nutritional and sensory implications were studied. The effect of dried beetroot juice on the formation of Ne-(carboxymethyl)lysine (CML) and Ne-(2-furoylmethyl)-L-lysine (furosine) was det

  5. The effect of beta-turn structure on the permeation of peptides across monolayers of bovine brain microvessel endothelial cells

    DEFF Research Database (Denmark)

    Sorensen, M; Steenberg, B; Knipp, G T;

    1997-01-01

    PURPOSE: To investigate the effects of the beta-turn structure of a peptide on its permeation via the paracellular and transcellular routes across cultured bovine brain microvessel endothelial cell (BBMEC) monolayers, an in vitro model of the blood-brain barrier (BBB). METHODS: The effective...

  6. Effect of gamma radiation on the content {beta}-carotene and volatile compounds of cantaloupe melon

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Stefania P. de; Cardozo, Monique; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: keila@ime.eb.br, E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME - Instituto Militar de Engenharia, RJ (Brazil)

    2011-07-01

    The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs{sub 137} source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in {beta}-carotene. Both total content of carotenoids and specific {beta}-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and {alpha} -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 k

  7. Mechanical loading prevents the stimulating effect of IL-1{beta} on osteocyte-modulated osteoclastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Rishikesh N.; Bakker, Astrid D.; Everts, Vincent [Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Amsterdam (Netherlands); Klein-Nulend, Jenneke, E-mail: j.kleinnulend@acta.nl [Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Amsterdam (Netherlands)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Osteocyte incubation with IL-1{beta} stimulated osteocyte-modulated osteoclastogenesis. Black-Right-Pointing-Pointer Conditioned medium from IL-1{beta}-treated osteocytes increased osteoclastogenesis. Black-Right-Pointing-Pointer IL-1{beta} upregulated RANKL and downregulated OPG gene expression by osteocytes. Black-Right-Pointing-Pointer CYR61 is upregulated in mechanically stimulated osteocytes. Black-Right-Pointing-Pointer Mechanical loading of osteocytes may abolish IL-1{beta}-induced osteoclastogenesis. -- Abstract: Inflammatory diseases such as rheumatoid arthritis are often accompanied by higher plasma and synovial fluid levels of interleukin-1{beta} (IL-1{beta}), and by increased bone resorption. Since osteocytes are known to regulate bone resorption in response to changes in mechanical stimuli, we investigated whether IL-1{beta} affects osteocyte-modulated osteoclastogenesis in the presence or absence of mechanical loading of osteocytes. MLO-Y4 osteocytes were pre-incubated with IL-1{beta} (0.1-1 ng/ml) for 24 h. Cells were either or not subjected to mechanical loading by 1 h pulsating fluid flow (PFF; 0.7 {+-} 0.3 Pa, 5 Hz) in the presence of IL-1{beta} (0.1-1 ng/ml). Conditioned medium was collected after 1 h PFF or static cultures. Subsequently mouse bone marrow cells were seeded on top of the IL-1{beta}-treated osteocytes to determine osteoclastogenesis. Conditioned medium from mechanically loaded or static IL-1{beta}-treated osteocytes was added to co-cultures of untreated osteocytes and mouse bone marrow cells. Gene expression of cysteine-rich protein 61 (CYR61/CCN1), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) by osteocytes was determined immediately after PFF. Incubation of osteocytes with IL-1{beta}, as well as conditioned medium from static IL-1{beta}-treated osteocytes increased the formation of osteoclasts. However, conditioned medium from mechanically loaded IL

  8. Heterogeneity of chromosome damage in [beta]-thalassaemia traits. An evaluation of spontaneous and [gamma]-ray-induced micronuclei and chromosome aberrations in lymphocytes in vitro after G[sub 0] and G[sub 2] phase irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaja, A.P.; Sharma, N.K. (Bhabha Atomic Research Centre, Bombay (India). Molecular Biology and Agriculture Div.)

    1994-07-01

    This study is an attempt to evaluate the chromosomal radiosensitivity of [beta]-thalassaemia traits compared with healthy individuals from the general population, necessitated by the fact that [beta]-thalassaemia trait is present in 1-17% of different population groups in India and the chances of encountering them in radiation and chemical related industries do exist. Spontaneous chromosome aberration frequencies in peripheral blood lymphocytes from [beta]-thalassaemia traits were found to be in the normal range, whereas significantly higher frequencies of micronuclei (MN) were observed in thalassaemia traits. Based on MN frequency at 2 Gy, [beta]-thalassaemia traits fall into two distinct categories. A hypersensitive group with significant increase in radiation-induced MN over the control group, and a second group with MN frequency slightly above normal individuals. Even when compared with the fitted data at 2 Gy obtained from the pooled results of extensive dose-response investigations from 0.5-5 Gy [gamma]-rays with normal donors for MN, dicentrics and total aberrations, the difference between the means of MN frequencies in [beta]-thalassaemia traits and normals is significant. (author).

  9. Effects of pituitary beta-endorphin secretagogues on the concentration of beta-endorphin in rat cerebrospinal fluid : evidence for a role of vasopressin in the regulation of brain beta-endorphin release

    NARCIS (Netherlands)

    Barna, I; Sweep, C G; Veldhuis, H D; Wiegant, V M; De Wied, D

    1990-01-01

    The concentration of beta-endorphin-immunoreactivity (beta E-IR) in cerebrospinal fluid (CSF) and plasma of rats was determined following intracerebroventricular (ICV) treatment of conscious animals with substances known to stimulate the release of beta E and other pro-opiomelanocortin (POMC)-derive

  10. The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study

    OpenAIRE

    Wilson, Jacob M; Ryan P. Lowery; Joy, Jordan M; Andersen, J. C.; Wilson, Stephanie M C; Stout, Jeffrey R; Duncan, Nevine; Fuller, John C; Baier, Shawn M.; Naimo, Marshall A.; Rathmacher, John

    2014-01-01

    Introduction Studies utilizing beta-hydroxy-beta-methylbutyrate (HMB) supplementation in trained populations are limited. No long-term studies utilizing HMB free acid (HMB-FA) have been conducted. Therefore, we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy, body composition, strength, and power in trained individuals. We also determined the effects of HMB-FA on muscle damage and performance during an overreaching cycle. Methods A three-phase dou...

  11. Effect of gamma-irradiation on the whitening activity of {beta}-glucan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Sung, Nak Yun; Jung, Pil Moon; Choi, Jong Il; Kim, Jin Kyu; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Byun, Eui Hong [Chungnam Naitonal University, Daejeon (Korea, Republic of)

    2010-09-15

    This study evaluated the change in whitening activity of {beta}-glucan by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 10 kGy irradiated {beta}-glucan. Melanin synthesis of irradiated {beta}-glucan was measured from B16BL6 melanoma cell line treated with {alpha}-melanin stimulating hormone. Melanin synthesis was increased in the {alpha}-melanin stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated {beta}-glucan treated with {alpha}-melanin stimulating hormone. These results indicate that gamma irradiated {beta}-glucan may elevate the whitening activity. Therefore, gamma-irradiated {beta}-glucan could be used for nutraceutical foods in cosmetic industry.

  12. Assessment of beta-emitter radionuclides in biological samples using liquid scintillation counting. Application to the study of internal doses in molecular and cellular biology techniques; Evaluacion en muestras biologicas de radionucleidos emisores beta mediante espectrometria de centelleo en fase liquida. Aplicaciones al estudio de dosis internas en tecnicas de investigacion de biologia molecular y celular

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, I.; Delgado, A.; Navarro, T.; Macias, M. T.

    2007-07-01

    The radioisotopic techniques used in Molecular and Cellular Biology involve external and internal irradiation risk. It is necessary to control the possible internal contamination associated to the development of these techniques. The internal contamination risk can be due to physical and chemical properties of the labelled compounds, aerosols generated during the performance technique. The aim of this work was to estimate the possible intake of specific beta emitters during the technique development and to propose the required criterions to perform Individual Monitoring. The most representative radioisotopic techniques were selected attending their potential risk of internal contamination. Techniques were analysed applying IAEA methodology according to the used activity in each technique. It was necessary to identify the worker groups that would require individual monitoring on the base of their specific risk. Different measurement procedures were applied to study the possible intake in group risk and more than 160 persons were measured by in vitro bioassay. (Author) 96 refs.

  13. Effect of biologic agents on radiographic progression of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Gabriel J Tobón

    2010-08-01

    Full Text Available Gabriel J Tobón1, Alain Saraux1,2, Valérie Devauchelle-Pensec1,21Immunology Laboratory, Morvan Hospital, Université de Bretagne Occidentale, Brest, France; 2Rheumatology Unit, Hôpital de la Cavale Blanche, CHU Brest, FranceAbstract: The treatment of rheumatoid arthritis (RA has benefited over the last few years from the introduction of biologic agents whose development was based on new insights into the immunological factors involved in the pathogenesis of RA and the development of joint damage. These biological agents have been proven effective in RA patients with inadequate responses to synthetic disease-modifying antirheumatic drugs (DMARDs. Preventing joint damage is now the primary goal of RA treatment, and guidelines exist for the follow-up of joint abnormalities. Most biologic agents produced high clinical and radiological response rates in patients with established or recent-onset RA. Thus, for the first time, obtaining a remission is a reasonable treatment goal in RA patients. Factors that are crucial to joint damage control are: early initiation of DMARDs, use of intensive treatments including biological agents, and close monitoring of clinical disease activity and radiographic progression. However, some patients remain unresponsive to all available treatments and continue to experience joint damage progression. A major objective now is to identify patients at high risk for severe joint damage, in order to tailor the treatment regimen to their specific needs.Keywords: rheumatoid arthritis, radiographic progression, biologics

  14. Diagram X-ray emission spectra of a hollow atom: the Kh alpha1,2 and Kh beta1,3 hypersatellites of Fe.

    Science.gov (United States)

    Diamant, R; Huotari, S; Hämäläinen, K; Sharon, R; Kao, C C; Deutsch, M

    2003-11-07

    High-resolution Fe K(h) beta(1,3) and K(h) alpha(1,2) hypersatellite spectra were measured, using monochromatized synchrotron radiation photoexcitation. The lines' energies, splitting, excitation thresholds, and the K(h) alpha(1)/K(h) alpha(2) intensity ratio were derived with high accuracy. Having both spectra, not hitherto available for any atom with high resolution, allows separating out the energy shifts of the outer levels caused by a K shell spectator vacancy. Comparison with ab initio relativistic multiconfigurational Dirac-Fock calculations reveals that while the influence of relativity and QED effects is mostly accounted for, discrepancies remain in the lines' intensity ratio, which sensitively measures the intermediacy of the coupling. Similar discrepancies, of unknown origin, are found in the energy shifts of the outer levels due to the final-state K shell spectator vacancy.

  15. Relativistic Effects on Reflection X-ray Spectra of AGN

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Khee-Gan; /University Coll. London; Fuerst, Steven V.; /KIPAC, Menlo Park; Brandwardi-Raymond, Graziella; Wu, Kinwah; Crowley, Oliver; /University Coll. London

    2007-01-05

    We have calculated the reflection component of the X-ray spectra of active galactic nuclei (AGN) and shown that they can be significantly modified by the relativistic motion of the accretion flow and various gravitational effects of the central black hole. The absorption edges in the reflection spectra suffer severe energy shifts and smearing. The degree of distortion depends on the system parameters, and the dependence is stronger for some parameters such as the inner radius of the accretion disk and the disk viewing inclination angles. The relativistic effects are significant and are observable. Improper treatment of the reflection component of the X-ray continuum in spectral fittings will give rise to spurious line-like features, which will mimic the fluorescent emission lines and mask the relativistic signatures of the lines.

  16. Predictive modeling of nanomaterial exposure effects in biological systems

    Directory of Open Access Journals (Sweden)

    Liu X

    2013-09-01

    Full Text Available Xiong Liu,1 Kaizhi Tang,1 Stacey Harper,2 Bryan Harper,2 Jeffery A Steevens,3 Roger Xu1 1Intelligent Automation, Inc., Rockville, MD, USA; 2Department of Environmental and Molecular Toxicology, School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, USA; 3ERDC Environmental Laboratory, Vicksburg, MS, USA Background: Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential hazards resulting from the application of engineered nanomaterials. Methods: We generated an experimental dataset on the toxic effects experienced by embryonic zebrafish due to exposure to nanomaterials. Several nanomaterials were studied, such as metal nanoparticles, dendrimer, metal oxide, and polymeric materials. The embryonic zebrafish metric (EZ Metric was used as a screening-level measurement representative of adverse effects. Using the dataset, we developed a data mining approach to model the toxic endpoints and the overall biological impact of nanomaterials. Data mining techniques, such as numerical prediction, can assist analysts in developing risk assessment models for nanomaterials. Results: We found several important attributes that contribute to the 24 hours post-fertilization (hpf mortality, such as dosage concentration, shell composition, and surface charge. These findings concur with previous studies on nanomaterial toxicity using embryonic zebrafish. We conducted case studies on modeling the overall effect/impact of nanomaterials and the specific toxic endpoints such as mortality, delayed development, and morphological malformations. The results show that we can achieve high prediction accuracy for certain biological effects, such as 24 hpf mortality, 120 hpf mortality, and 120 hpf heart malformation. The results also show that the weighting scheme for individual biological effects has a significant influence on modeling the overall impact of

  17. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together