UK PubMed Central (United Kingdom)

PurposeA prolonged seizure, status epileptics (SE), is a potent stimulus for increased neurogenesis in the dentate gyrus of the hippocampus. Molecular mechanisms...Full Text Available

Wastenet

...Basic Information | Fuel Cells & Vehicles | US EPA This web page provides basic information on EPA's Fuel Cells & Vehicles web site ...including the chemical composition of fuel cell technology, how it works, descriptions of the various types of fuel cells , their availability and ... background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,increased engine efficiency,lower emissions,zero emissions,availablity,fuel cell types,diagram,Proton ...Exchange Membrane,PEM Basic Information | Fuel Cells & Vehicles | US EPA background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,...

British Library Electronic Table of Contents (United Kingdom)

The key factors of enzymatic lysis of cells are the interaction between the enzyme and the cell - catalytic and non-catalytic adsorption of enzyme on cell surface. Here, the studies of lysis of intact Escherichia coli cells by chicken egg white lysozyme were performed. It was found that the ionic strength has a dual effect onto the system. On the one hand, the desorption constant of the enzyme increases with the increase of the solution ionic strength, which results in a better enzyme performance. On the other hand, due to the higher osmosis, the cell lysis rate decreases with the increasing of ionic strength of the system. It was found that pH 8.6 and 30mM NaCl are optimal conditions for lysis of E. coli cells by lysozyme.

Energy Technology Data Exchange (ETDEWEB)

As concern regarding global environmental problems such as the greenhouse effect and acid rain has increased, so too has the demand for commercially viable solar cells as a clean energy source. Interest in amorphous silicon (a-Si) solar cells has been particularly high, due to their low cost. Technological developments in the field of a-Si solar cells are discussed from the viewpoints of fabrication process, materials, and cell structures. Various applications and systems that take advantage of the a-Si solar cell are then introduced. Finally, future prospects are mentioned

UK PubMed Central (United Kingdom)

Hematological deficiencies increase with aging leading to anemias, reduced hematopoietic stress responses and myelodysplasias. This study tested the hypothesis that side population hematopoietic...Full Text Available

UK PubMed Central (United Kingdom)

Vascular permeability factor (VPF) is an Mr 40-kD protein that has been purified from the conditioned medium of guinea pig line 10 tumor cells grown in vitro, and increases fluid permeability from blood...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundIncreasing evidence demonstrates that stem cells maintain their identities by a unique transcription network and chromatin structure. Opposing epigenetic modifications...Full Text Available

UK PubMed Central (United Kingdom)

In the body, vascular cells continuously interact with tissues that possess nanostructured surface features due to the presence of proteins (such as collagen and elastin) embedded in the vascular wall....Full Text Available

UK PubMed Central (United Kingdom)

IntroductionIn critically ill patients the relationship between the storage age of red blood cells (RBCs) transfused and outcomes are controversial. To determine if duration of RBC...Full Text Available

UK PubMed Central (United Kingdom)

Cells of the terrestrial plant species bromegrass (Bromus inermis L.) are not naturally adapted to withstand the hydrostatic pressures encountered in aquatic environments. However,...Full Text Available

International Nuclear Information System (INIS)

Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. ...

British Library Electronic Table of Contents (United Kingdom)

The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and dif...

British Library Electronic Table of Contents (United Kingdom)

Cyclooxygenase-2 (COX-2) content is increased in many types of tumor cells. We have investigated the mechanism by which resveratrol, a stilbene that is pro-apoptotic in many tumor cell lines, causes apoptosis in human head and neck squamous cell carcinoma UMSCC-22B cells by a mechanism involving cellular COX-2. UMSCC-22B cells treated with resveratrol for 24 h, with or without selected inhibitors, were examined: (1) for the presence of nuclear activated ERK1/2, p53 and COX-2, (2) for evidence of apoptosis, and (3) by chromatin immunoprecipitation to demonstrate p53 binding to the p21 promoter. Stilbene-induced apoptosis was concentration-dependent, and associated with ERK1/2 activation, serine-15 p53 phosphorylation and nuclear accumulation of these proteins. These effects were blocked by ...

Science.gov (United States)

We report for the first time a relationship between the Tpl-2/cot oncogene and Mouse Mammary Tumor Virus (MMTV) associated transformation of mammary gland cells. A sub-genomic library generated from a primary mammary gland tumor yielded a novel MMTV integration site which disrupted the Tpl-2/cot proto-oncogene between exons 7 and 8. Comparison of a cell line derived from normal mammary gland (comma-D) and a cell line established from an MMTV induced mammary tumor (GR) demonstrated similar rearrangements within Tpl-2/cot for the GR cells but not in the comma-D cells. These rearrangements in the cell line were accompanied by an increase in the level of Tpl-2/cot specific mRNA. This data suggests that Tpl-2/cot expression may be important in epithelial cell transformation or tumor progression. PMID:8934549

Energy Technology Data Exchange (ETDEWEB)

A rat hepatocyte cell line was shown previously to contain a nuclear pool of free heparan SO/sub 4/ (HS) chains which turns over rapidly. These cells were labeled with /sup 35/SO/sub 4//sup 2 -/ and the steady state levels of (/sup 35/SO/sub 4/)HS in the nucleus were measured under culture conditions chosen to give different cell doubling times (DT's). In each log phase culture growing at a constant rate, the level of nuclear HS did not change as the cell density increased. Rapidly dividing cells had levels of nuclear HS within the range of 30-42 pmol /sup 35/SO/sub 4/ in the nuclear HS/10/sup 6/ cells. However, in cultures with decreased DT's, there was a corresponding decrease in the level of nuclear HS below 30 pmol/10/sup 6/ cells that was proportional to the decrease in the DT. In contrast, when ...

Energy Technology Data Exchange (ETDEWEB)

Studies of various established human bladder and renal carcinoma cell lines cultured in vitro demonstrated the presence of specific, saturable, high affinity binding sites for /sup 125/I-labeled human interferon Beta ser IFN-beta ser). This recombinant produced interferon labeled with approximately one atom of /sup 125/I/molecule of IFN expressed minimal or no loss of antiviral activity. A single class of binding sites (1000-2000/cell) with an affinity constant of 10(10)-10(11) L/M was measured at 4 degrees C for cells exhibiting widely different sensitivity to the antiproliferative effect of IFN-beta ser. Major fluctuations in the binding of /sup 125/I-labeled IFN-beta ser to cellular receptors were observed during in vitro proliferation of four of five cell lines examined. A significant decrease (P less than 0.001) in specific binding was observed 48 h after cultures were established. ...

British Library Electronic Table of Contents (United Kingdom)

In several vertebrate classes, the M?ller glia are capable of de-differentiating, proliferating, and acquiring a progenitor-like state in response to acute retinal injury or in response to exogenous growth factors. Our previous study has shown that M?ller cells can be activated and de-differentiated into retinal progenitors during Royal College of Surgeons (RCS) rats' degeneration, although the limited proliferation cannot maintain retinal function. We now report that rat retinal stem cells (rSCs) transplanted into RCS rats slowed the progression of retinal morphological degeneration and prevented the functional disruption. Further, we found that retinal progenitor cells labeled with Chx10 were increased significantly after rSCs transplantation, and most of them are mainly from activated M...

Energy Technology Data Exchange (ETDEWEB)

The geometrical and chemical effects of cerium (Ce) addition to Ni-Cr anode electrode in molten carbonate fuel cells (MCFCs) were investigated by measuring the fractal dimensions and wettability of four types of anode electrode with Ce added up to 5 wt.%. In addition, their cell performances were investigated through a single cell operation test and their results were explained based on the wettability of the anode electrodes. The addition of Ce to the anode electrode increased the fractal dimensions and wettabilities of the electrodes. Despite the even larger electrical resistivity of Ce compared to that of Ni and Cr, the electrical resistances of the Ce-added anode electrodes were slightly increased with increasing level of Ce addition. This might be ascribed to the greater wettability of the Ce-added anode electrode that enhanced the cell ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Purpose: To describe the pattern of expression of the cyclin-dependent kinase inhibitors (CDKIs) p16, p21 and p27, and the cell cycle in SRA 01/04 cells relative to contact inhibition. Methods: SRA 01/04 cells were grown to overconfluence under normal conditions. At various phases of the cell growth, cells were assayed by flow cytometry and Western blotting for the expression of CDKIs. Results: Expression of p16 was detected from early logarithmic growth to stationary phases, during which the number of cells in G0/G1 increased from 46 to 69%. Expression of p21 was detected only during the overgrowth phase, when 60% of the cells were in G0/G1. Expression of p27 was not observed in SRA 01/04 cells. Conclusions: p16 expression was likely mediated by G0/G1 arrest to induce contact inh...

International Nuclear Information System (INIS)

CO poisoning is a major issue when reformate is used as a fuel in PEM fuel cells. Normally it is necessary to reduce the CO to very low levels (#approx#5 ppm) and CO tolerant catalysts, such as Pt-Ru, are often employed. As an alternative approach, we have studied the use of pulsed oxidation for the regeneration of CO poisoned cells. Results are presented for the regeneration of Pt and Pt-Ru anodes in a PEM fuel cell fed with CO concentrations as high as 10,000 ppm. The results show periodic removal of CO from the catalyst surface by pulsed oxidation can increase the average cell potential and increase overall efficiency. A method for enhancing the performance of a fuel cell stack using a microprocessor-based Fuel Cell Health Manager (FCHM) has been developed. The results of a cost/benefit analysis for the use of a FCHM ...

British Library Electronic Table of Contents (United Kingdom)

The present study was aimed at investigating effects of nickel (NiCl2) on secretion of testosterone (T), cell viability, ultrastructure and apoptosis in mouse Leydig cells. Testosterone release was measured after 48h of culture with 15.67, 31.25, 62.5, 125, 250, 500 and 1000mmol/L NiCl2 or without NiCl2 using radioimmunoassay. Cell viability was assessed by a MTT (metabolic activity assay). Quantification of apoptotic cells was performed using TUNEL assay and the ultrastructural changes were analyzed using transmission electron microscopy. The viability was decreased after addition of >=250mmol/L NiCl2. A concentration-dependent depression of T production was observed. The percentage of apoptotic cells was significantly increased only after addition of 125, 250 and 1000mmol/L NiCl2. After ...

British Library Electronic Table of Contents (United Kingdom)

ObjectivesTo assess the influence of epigallocatechin-3-gallate (EGCG) on the efficacy of ionizing radiation on prostate cancer cells because of the increased use of dietary interventions, especially by patients with prostate cancer. Radiotherapy is used to treat localized prostate cancer. Some people consume green tea (EGCG) as a chemopreventive agent against prostate cancer. Green tea can act as an antioxidant and induce superoxide dismutase enzymes, which could scavenge the free oxygen radicals generated by radiotherapy. MethodsProstate cancer cell line DU145 cells were treated with EGCG or radiotherapy, or both. Cell death was assessed using trypan blue cell counting, and apoptosis was confirmed by assessing poly (adenosine phosphate ribose) polymerase cleavage. The antioxidant potenti...

Energy Technology Data Exchange (ETDEWEB)

In this experiments, we established long-termed culture methods of bone marrow stromal cells for proliferation and differentiation of stem cells. And we selected some extracts which support maximal proliferation of stromal cells with this method. We conformed the synergic effects of herbal mixture extracts for stromal cell growth. The proliferation of stromal cells was increased rather by the addition of mixture extracts than by addition of single strain extract. In the previous and cooperative experiments, we selected complex extracts (Him-I, Him-II) which increased the number of nonadherent mononuclear cells. Different cytokine expression patterns were observed stromal cells cultured in the presence or absence of mixture extracts which support differentiation of nonadherent ...

Energy Technology Data Exchange (ETDEWEB)

Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical topographies on the cell ...

Scientific Electronic Library Online (English)

Abstract in english Cell death is preceded by severe disruption of inorganic ion homeostasis. Seconds to minutes after an injury, calcium, protons, sodium, potassium and chloride are exchanged between the cell and its environment. Simultaneously, ions are shifted between membrane compartments inside the cell, whereby mitochondria and endoplasmic reticulum play a crucial role. Depending of the type and severity of injury, two mutually exclusive metastable states can be reached, which predict (more) the final outcome. Cells characterized by large increases in cytosolic [Ca2+], [Na+]; and [Mg2+] swell and die by necrosis; alternatively, cells characterized by high [H+]and low [K+], with normal [Na+] and normal to moderate [Ca2+] increases die by apoptosis. The levels of these ions represent central determinants in signaling events leading to ...

British Library Electronic Table of Contents (United Kingdom)

A red basil cell line (T2b) rich in rosmarinic acid (RA) was selected for the stable production of anthocyanins (ACs) in the dark. Cell suspension cultures were subjected to mechanical stress through increased agitation (switch from 90 to 150rpm) to determine the relationship between AC and RA accumulation. Cell extracts were analyzed by HPLC and LC-MS, and the resulting data were processed with multivariate statistical analysis. MS and MS/MS spectra facilitated the putative annotation of several complex cyanidin-based ACs, which were esterified with coumaric acid and, in some cases, also with malonic acid. It was also possible to identify various RA-related molecules, some caffeic and coumaric acid derivatives and some flavanones. Mechanical stress increased the total AC and RA contents, ...

International Nuclear Information System (INIS)

The thiazolidinedione (TZD) or glitazone class of peroxisome proliferator-activated-#gamma# (PPAR-#gamma#) ligands not only induce adipocyte differentiation and increase insulin sensitivity, but also exert growth inhibitory effects on several carcinoma cell lines in vitro as well as in vivo. In the current study the in vitro effect of four PPAR-#gamma# agonists (ciglitazone, pioglitazone, troglitazone, rosiglitazone) on the cell growth of seven human neuroblastoma cell lines (Kelly, LAN-1, LAN-5, LS, IMR-32, SK-N-SH, SH-SY5Y) was investigated. Growth rates were assessed by a colorimetric XTT-based assay kit. Expression of PPAR-#gamma# protein was examined by immunohistochemistry and Western blot analysis. All glitazones inhibited in vitro growth and viability of the human neuroblastoma cell lines in a dose-dependent manner showing considerable effects only at high concentrations (10 ...

British Library Electronic Table of Contents (United Kingdom)

Abstract: The ability of melatonin as a potent antioxidant was used as a rationale for testing its antiapoptotic ability in normal cells. Recently, melatonin was shown to possess proapoptotic action by increasing reactive oxygen species in certain cancer cells. The modification of radiation-induced apoptosis by melatonin and the expression of apoptosis-associated upstream regulators were studied in normal mice splenocytes and Jurkat T leukemia cells. C57BL/6 mice were exposed to a single whole body X-ray radiation dose of 2 Gy with or without 250 mg/kg melatonin pretreatment. The Jurkat cells were divided into four groups of control, 1 mm melatonin alone, 4 Gy irradiation-only and melatonin pretreatment before irradiation. The highest level of apoptosis in the normal splenic white pulp was...

International Nuclear Information System (INIS)

Pregnant Swiss albino mice of 18 days post conception were exposed to 0.80 Gy, 0.40 Gy and 0.20 Gy of gamma rays from a Cobalt-60 source at different dose rates (.0584 Gy/min and .00091 Gy/min). Post irradiation variations in the cell population of crypts and villus of jejunum were studied in the F_1-generation at 1 day, 3 day and 1,2,4,6 and 12 weeks of post-partum age. In all the exposure groups at 1 day post-partum age, crypts show a decrease in total cells, mitotic figures and goblet cells on one hand and an increase in PNNC on the other hand in comparison to coeval controls. At this interval a decrease in the number of total cells as well as goblet cells/villus column was also noticeable. Dead cells which were prominently seen in crypts were totally absent in villi. The first signs of recovery can be observed on day 3 p.p. when total ...

International Nuclear Information System (INIS)

The p75 neurotrophin receptor (p75"N"T"R) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75"N"T"R retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (#DELTA#DD) dominant-negative antagonist of p75"N"T"R showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75"N"T"R-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the ...

Energy Technology Data Exchange (ETDEWEB)

Glycosaminoglycan synthesis was studied in cell populations of ultraviolet light-induced murine cutaneous fibrosarcoma cells under conditions of varying growth rates in vitro. After labeling with the precursors, /sup 3/H-glucosamine and /sup 35/SO/sub 4/, sulfated glycosaminoglycans recoverable by direct proteolysis of the culture monolayers increased approximately 5-fold on a per cell basis from sparsely populated, exponential cell cultures (greater than 85% of cells in S, G2, or M phases) to stationary cultures inhibited by high cell density (greater than 50% of cells in G1). Within this cell surface-associated material, the relative ratio of heparan sulfate to the chondroitin sulfates was approximately 60/40% under conditions of exponential growth; in the growth-arrested cultures, the reverse ...

UK PubMed Central (United Kingdom)

OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the...Full Text Available

UK PubMed Central (United Kingdom)

Strategies to combine aspirated marrow cells with scaffolds to treat connective tissue defects are gaining increasing clinical attention and use. In situations such as large defects where initial...Full Text Available

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

Some cases of autism spectrum disorder (ASD) have mutations in the lipid phosphatase, Pten (phosphatase and tensin homolog on chromosome 10). Tissue...Full Text Available

UK PubMed Central (United Kingdom)

Experience with visual objects leads to later improvements in identification speed and accuracy (“repetition priming”), but generally leads to reductions in neural activity in single-cell...Full Text Available

UK PubMed Central (United Kingdom)

Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of cellular aging. Mild stress-induced hormesis can be an effective way for reducing the accumulation of molecular...Full Text Available

UK PubMed Central (United Kingdom)

The photosynthetic activity of the green alga Scenedesmus quadricauda was investigated during synchronous growth in light/dark cycles. The rate of O₂ evolution increased...Full Text Available

UK PubMed Central (United Kingdom)

We report herein that trefoil factor 3 (TFF3) is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma. Forced expression of TFF3 in mammary carcinoma cells increased cell proliferation...Full Text Available

UK PubMed Central (United Kingdom)

We have shown that addition of exogenous delta-aminolaevulinic acid (ALA) to rat pancreatoma AR4-2J cells in culture leads to the increased production of porphobilinogen (PBG) and the accumulation of...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

One of the first technical applications of gene technology is reported here. The DNA of E. coli cells was rearranged such that these cells produce large quantities of the enzyme ..cap alpha..-galactosidase. This enzyme is used to split the trisaccharide, raffinose, which is formed during the production of sugar from sugar beet. By this means sugar yields can be increased and the energy required for sugar crystallisation reduced.

Energy Technology Data Exchange (ETDEWEB)

The number and type of stem cells in spleen and bone marrow of mice were determined after exposure to a single dose of 150 R on day 6, to a single dose of 500 R on day 6 or day 9 or to a fractionated dose of 150 R + 350 R on day 6 and 9. The stem cells were assayed on the basis of colony forming units (CFU) in spleen and of incorporation of iododeoxyuridine in spleen and bone marrow of lethally irradiated host mice. During the first month of life, the number of stem cells in non-irradiated mice increases markedly in bone marrow and slightly in spleen. Irradiation causes a long-lasting depression in stem cells, particularly in bone marrow and affecting preferentially erythropoietic precursor cells. Following a dose of only 150 R, the number of CFU in bone marrow is still below control levels 24 days later. An exposure to 500 R fractionated between day 6 and 9 has ...

Energy Technology Data Exchange (ETDEWEB)

Radioadapted chicken embryo cells (X-irradiation in ovo with 10 cGy at the 14th day of development with priming periods of 24 h) were treated in vitro by challenge doses of 14 different DNA- and/or chromatin-interactive agents, including X-rays. A decrease in the cellular damage, as measured by scheduled DNA synthesis, was only observed with X-irradiation. Sedimentation of nucleoids as well as viscosity of alkaline lysates from ethidium bromide (0.35-400 {mu}g/ml)-, vovobiocin (125-1800 {mu}g/ml)-, and hyperthermia (30 min at 43 and 45 )-treated cells suggest a higher tendency of radioadapted cells to undergo positive DNA supercoiling. When DNA from adapted and non-adapted chicken embryo cells was used as substrate, neither its digestion by DNase I nor the inhibition of DNase I activity by various DNA-interactive agents was changed in primed cells. From the previous investigations ...

Energy Technology Data Exchange (ETDEWEB)

Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625-5 x 10/sup -5/M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in dimished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into ...

Energy Technology Data Exchange (ETDEWEB)

An intensified integration of renewable energies and a more extensive use of combined heat and power lead to an increasingly decentralized power economy. Such an economy is characterized by the conversion of energy at the point of the energy demand and depending on the energy system, by the possibility of balancing the fluctuating supply of renewable energies. In the long run, there is no doubt that fuel cells will be part of such a sustainable and flexible energy concept. The scope of this dissertation includes an analysis of the flexibility of fuel cells in energy supply (1,5 kW{sub el}), an assessment of the potential to compensate for the fluctuating supply of wind energy by an aggregation of decentralized fuel cells and a participation as a contractor in the spot and balance energy markets. Therefore two fuel cells were monitored and tested in order to obtain their ...

International Nuclear Information System (INIS)

One rationale proposals to increase the efficiency of PDT is to combine photo-sensitization with other treatment modalities, including modulation of arachidonic acid metabolism. In combine treatment we examined the effects of 48 h and 24 h pre-treatment of cells with 5- lipoxygenase inhibitor MK-886 prior to photoactivation of hypericin on cell cycle distribution and DNA synthesis. All parameters were examined 24 hours after hypericin activation. Pre-treatment of HT-29 with 5-lipoxygenase inhibitor MK-886 followed by PDT resulted in most significant effects on cell cycle perturbations. Administration of MK-886 alone as well as combination of low doses MK-886 with hypericin induced S phase accumulation. Increasing of MK-886 concentration induced massive changes in the cell cycle progression. Pre-treatment of HT-29 cells with MK-886 alone (15 ...

Energy Technology Data Exchange (ETDEWEB)

Mobility reduction induced by the growth and metabolism of bacteria in high-permeability layers of heterogeneous reservoirs is an economically attractive technique to improve sweep efficiency. This paper describes an experimental study conducted in sandpacks using an injected bacterium to investigate the strength and stability of microbial plugs in porous media. Successful convective transport of bacteria is important for achieving sufficient initial bacteria distribution. The chemotactic and diffusive fluxes are probably not significant even under static conditions. Mobility reduction depends upon the initial cell concentrations and increase in cell mass. For single or multiple static or dynamic growth techniques, permeability reduction was approximately 70% of the original permeability. The stability of these microbial plugs to increases in pressure gradient and changes in cell ...

Energy Technology Data Exchange (ETDEWEB)

This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

British Library Electronic Table of Contents (United Kingdom)

Increasing evidence has been accumulated indicating the important role of epigenetic regulation in tumor genesis. Previously, we observed that the transfection of hepatitis C virus core (HCVc) protein led to malignant transformation in normal biliary cells, and that tumor suppressor gene RASSF1A was downregulated in many hilar cholangiocarcinoma patients by hypermethylation in the promoter region. In the present study, we found SET and MYND domain-containing protein 3 (SMYD3), a novel histone methyltransferase, was overexpressed in cholangiocarcinoma patients especially in those with HCV infection. Transfection of HCVc into hilar cholangiocarcinoma cell lines QBC939 and FRH0201 could upregulate the expression of SMYD3 and promote cell growth, which was consistent with the results of our cl...

Science.gov (United States)

The fuel cell control problem was studied. Attempts were made to control the output current of the fuel cell by starving it of hydrogen and oxygen. The motivation of this work was to increase efficiency by minimizing waste of fuel. The following findings were obtained: H2 starvation works better than O2 starvation; An optimal H2 to O2 ratio exists for combined H2&O2 starvation; The control scheme for H2&O2 starvation works well for 3 different disturbance tests and at 25 degrees C, 60 degrees C, and 80 degrees C; Fuel cell under reactant starvation is stable for at least 72 hrs.

Energy Technology Data Exchange (ETDEWEB)

In recent years, interest in the development of a polymer electrolyte fuel cell (PEFC) has considerably increased due to its advantages (e.g., high power density) compared with other fuel cell systems, and its potentials to become the power plant for the next generation, nonpolluting automobile engine. For large scale application of fuel cells, low platinum loading electrode structures are necessary. An electrode based on a highly porous carbonized polyacrylonitrile foam material with very low platinum loading ({approximately} 13 {micro}g/cm{sup 2}) was prepared. The performance of this electrode for oxygen reduction was evaluated and compared with bulk platinum and glassy carbon electrodes.

Energy Technology Data Exchange (ETDEWEB)

To identify radio-protective agent candidate among medicinal plants and to elucidate the mechanism of action of the candidate material by using modern biochemical and molecular biological methods, we screened radio-protective activity among 48 medicinal plants. Seven samples showed above 20% protective activities against oxidative cell damage: Euryale ferox, Glycyrrhiza uralensis, Salvia miltiorrhiza, Eucomia ulmoides, Paeonia suffruticosa, Spirodela polyrrhiza, and Nelumbo nucifera. We also screened for oxidative stress sensitizing activity among other 51 medicinal plants. Among those samples, 11 samples showed good sensitizing effect; Melia azedarach, Agastache rugosa, Catalpa ovata, Prunus persica, Sinomenium acutum, Pulsatilla koreana, Oldenlandia diffusa, Anthriscus sylvestris, Schizandra chinensis, Gleditsia sinensis, and Cridium officinale. We also reported the radio-protective effect of DTT. The treatment of DTT increased ...

International Nuclear Information System (INIS)

Methods: Systemic irradiation of neuroaxis is an essential part in the management of medulloblastoma, stPNET and intracranial germ cell tumors. The introduction of quality assurance programs in radiooncology assures a precise radiotherapy of target volumes and is a prerequisite to improve survival. Results: Hyperfractionated radiotherapy has the potential of increasing dose to tumor more safely without increasing the risk for late adverse effects. Pilot studies revealed excellent tumor control in medulloblastoma with acceptable acute toxicity and a long-term survival of up to 96%. In medulloblastoma stereotactic radiation techniques reveal an acceptable toxicity and promising results in tumor control in recurrent disease or as primary treatment. They are now part of future treatment protocols in case of persisting residual tumor. Radiotherapy alone in pure germinoma is continuously yielding high cure rates. In secreting ...

Energy Technology Data Exchange (ETDEWEB)

Irradiation with a single dose of 30 Grey on the basal regions of the lungs of Sprague-Dawley rats induced a peribronchial and alveolar inflammation. Infiltration of mast cells in the edematous alveolar interstitial tissue and also in the peribronchial tissue were characteristic features of the lesion. The appearance of mast cells was already seen 4 wk after irradiation and by weeks 6 to 8 there was a heavy infiltration. The staining properties suggested that they were connective tissue-type mast cells. The infiltration of mast cells was paralleled by an accumulation of hyaluronan (hyaluronic acid) in the alveolar interstitial tissue 6 and 8 wk after irradiation. The recovery of hyaluronan (HA) during bronchoalveolar lavage (BAL) of the lungs also increased at this time. Treatment with a mast cell secretagogue, compound 48/80, induced a distinct reduction of ...

Energy Technology Data Exchange (ETDEWEB)

The petroleum and petroleum products increase offer a real development opportunity to the alternative fuels. In the context of the french energy accounting increase, the energy independence notion incites the government to promote these new fuels. If the LPG seems declining because of the accident risks fear, the fuel cell is not for today. Near these two sectors what is the future of the biofuels and the natural gas vehicle or the electric cars? (A.L.B.)

Energy Technology Data Exchange (ETDEWEB)

Breast cancer progression is characterized by inappropriate cell growth. Normal cells cease growth after a limited number of cell divisions--a process called cellular senescence-while tumor cells may acquire the ability to proliferate indefinitely (immortality). Inappropriate expression of specific oncogenes in a key cellular signaling pathway (Ras, Raf) can promote tumorigenicity in immortal cells, while causing finite lifespan cells to undergo a rapid senescence-like arrest. We have studied when in the course of transformation of cultured human mammary epithelial cells (HMEC), the response to overexpressed oncogenic Raf changes from being tumor-suppressive to tumor enhancing, and what are the molecular underpinnings of this response. Our data indicate: (1) HMEC acquire the ability to maintain growth in the presence of oncogenic Raf not ...

Energy Technology Data Exchange (ETDEWEB)

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to 577MeV/nucleon incident Fe ions in vitro. ...

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Cell death in general can be a physiological process of cell number regulation in tissue, or it can be the result of exo or endogenous injuries, such a low-dose of radiation. Chicken B cell population in the bursa of Fabricius are very susceptible to PCD. Our present studies concern the development of radiation damage of chicken defence mechanisms. In 6 experiments pathogen free chicken were irradiated by gamma rays with the total doses of 0.25, 0.5, 1.0, 2.0 and 4.0 Gy. The induction of apoptosis was checked by Flow-cyto-meter 12 h after irradiation in bursa cell suspension. There is some increase in the number of induced apoptotic cells 12 h after irradiation at the dose 0.5-.4.0 Gy. There were no significant changes in the proportion of proliferating lymphocytes (G2 M), but cellularity decreased significantly at dose 2.0 and 4.0 Gy/12 h after irradiation. ...

International Nuclear Information System (INIS)

'Full text:' Deregulation, distributed generation, combined heat and power, renewables, fuel cells, hydrogen. Power companies are facing a rapidly evolving environment that is testing their ability to effectively deploy capital and earn profits. While recent deregulation trends have shifted the structure of power markets into separating generators from distributors, the improving economic value proposition offered by smaller scale distributed generation technologies - such as fuel cells - would seem to be a conflicting development. In this complex and changing environment, decisions based on the economic reality of the capital markets are likely to prevail. By examining the opportunity to enhance risk management offered by stationary fuel cells, particularly in CHP applications, we provide a context for the issues being discussed in today's sessions focusing on power companies and electric utilities. Our risk management ...

International Nuclear Information System (INIS)

Early effects of 100 Kilorads of X-rays on muscle cell membrane properties have been measured in sartorius muscles from Leptodactylus ocellatus. Threshold strength for rectangular current pulses increased 10% after irradiation, and action potential propagation velocity decreased 10%. Passive membrane parameters were calculated from potential responses to sub-threshold current pulses, assuming conventional cable theory. Specific membrane conductance increased to 18% after irradiation, membrane capacitance increased 14%, and length constant decreased 10% but membrane time constant was unchanged. Cell diameter decreased 5%, and resting membrane potential decreased 8%. Membrane parameters during an action potential were also evaluated by the phase-plane and current-voltage plot techniques. Irradiation significantly decreased the action potential amplitude, the excitation potential, and ...

International Nuclear Information System (INIS)

Many hormones elicit effects on target cells by stimulating the enzyme phospholipase-C, which catalyzes the hydrolysis of phosphoinositides to the intracellular second messengers diacylglycerol and inositol phosphates. The present study examined the roles of FSH and guanine nucleotide-binding proteins (G-proteins) in regulating the hydrolysis of phosphoinositides in Sertoli cells. Sertoli cell cultures prepared from 16- to 18-day-old rats were incubated for 24 h with myo-[2-3H] inositol to label endogenous phospholipids. Treatment of cells from 0.5-20 min with preparations of ovine FSH ranging in potency from 1-60 times that of NIH FSH S1 did not affect accumulation of inositol phosphates. Levels of total [3H]inositol phosphates [[3H]inositol mono-, di-, and triphosphates (IP, IP2, and IP3)] in FSH-treated cultures was 75-120% the levels in control cultures over the various time intervals studied. ...

Science.gov (United States)

Influenza virus infection during pregnancy has been implicated as one of cause of premature delivery, abortion and stillbirth. We have reported that cultured human fetal membrane chorion cells undergoing apoptosis by influenza virus infection secrete unidentified heat-stable monocyte differentiation-inducing (MDI) factors. In this study, cellular, biological and immunochemical characteristics of MDI factors were investigated using human monocytic leukemia THP-1 cells by nitroblue tetrazolium reduction and cell adhesion assays. The treatment of THP-1 cells with culture supernatants from the influenza virus-infected chorion cells induced the nitroblue tetrazolium reduction ability, which was inhibited by the addition of superoxide dismutase and diphenyleneiodonium chloride, an inhibitor for reduced nicotinamide adenine dinucleotide phosphate oxidase. The phenomenon was also observed ...

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Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for {sup 90}Y, {sup 177}Lu, {sup 103m}Rh and {sup 211}At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde{sub TCP=0.99}) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for {sup 103m}Rh and {sup 211}At, respectively. TCP for {sup 90}Y was not ...

Energy Technology Data Exchange (ETDEWEB)

The mechanisms of brown adipocyte proliferation and differentiation during cold acclimation (and/or adaptation to hyperphagia) have been studied by quantitative photonic radioautography. (/sup 3/H)thymidine was injected to warm-acclimated (25/sup 0/C) rats and to animals exposed to 5/sup 0/C for 2 days. Samples of interscapular brown adipose tissue were collected for quantitative analysis of mitotic frequencies at various periods of time (4 h-15 days) after the injection of (/sup 3/H)thymidine, the rats being maintained at the temperatures to which they were initially exposed. It was found that cold exposure for 2 days markedly enhanced mitotic activity in endothelial cells, interstitial cells, and brown preadipocytes rather than in fully differentiated brown adipocytes. The total tissue labeling index (percent of labeled nuclei) increased approx.70 times over control values. The authors now report that cellular labeling ...

Energy Technology Data Exchange (ETDEWEB)

The performance of a 6 kW proton exchange membrane (PEM) electrolyzer was modeled using a semiempirical equation. Total cell voltage was represented as a sum of the Nernst voltage, activation overpotential and ohmic overpotential. A temperature and pressure dependent Nernst potential, derived from thermodynamic principles, was used to model the 20 cell PEM electrolyzer stack. The importance of including the temperature dependence of various model components is clearly demonstrated. The reversible potential without the pressure effect decreases with increasing temperature in a linear fashion. The exchange current densities at both the electrodes and the membrane conductivity were the coefficients of the semiempirical equation. An experimental system designed around a 6 kW PEM electrolyzer was used to obtain the current-voltage characteristics at different stack temperatures. A nonlinear curve fitting method was employed to ...

British Library Electronic Table of Contents (United Kingdom)

Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding a3, a5 and b4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR a5 with a-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addit...

International Nuclear Information System (INIS)

Cigarette smoking is the major environmental risk factor for bladder cancer in humans. Aromatic amines, potent DNA-reactive bladder carcinogens present in cigarette smoke, contribute significantly. However, increased cell proliferation, caused by direct mitogenesis or in response to cytotoxicity, may also play a role since urothelial hyperplasia has been observed in human cigarette smokers. We examined the urothelial effects of cigarette smoke (whole body inhalation exposure (Teague) system) in female C57BL/6 mice at various times in two studies, including reversibility evaluations. In both studies, no urothelial hyperplasia was observed by light microscopy in any group. However, in study 1, the Ki-67 labeling index (LI) of the urothelium was significantly increased in the smoke exposed group compared to controls through 3 months, but was not present at 6, 9 or 12 months even with continued exposures. In the groups that ...

Energy Technology Data Exchange (ETDEWEB)

Although the majority of men presenting with non-seminomatous germ cell tumours (NSGCT) are cured, late relapse (occurring more than 2 years after obtaining a complete response to treatment) is increasingly recognized. The typical patterns of disease spread have been well-documented, but the findings at late relapse are more variable and less well-described. We discuss the phenomenon of late relapse, the characteristics of teratoma differentiated (TD), and the issue of long-term imaging surveillance of patients with NSGCT. The potential sites of late relapse of NSGCT and the associated spectrum of imaging appearances are illustrated.

British Library Electronic Table of Contents (United Kingdom)

Resistance and tolerance are two types of host defense mechanisms that increase fitness in response to fungi. Several genetic polymorphisms in pattern recognition receptors, most remarkably Toll-like receptors (TLRs), have been described to influence resistance and tolerance to aspergillosis in distinct clinical settings. TLRs on dendritic cells pivotally contribute in determining the balance between immunopathology and protective immunity to the fungus. Epithelial cells also contribute to this balance via selected TLRs converging on indoleamine-2,3-dioxygenase (IDO). Studies in experimental hematopoietic transplantation confirmed the dichotomy of pathways leading to resistance and tolerance to the fungus providing new insights on the relative contribution of the hematopoietic/nonhematopoi...

British Library Electronic Table of Contents (United Kingdom)

A new simple multi-well plate-based assay to determine monocyte differentiation-inducing activity was developed. It is based on the increase of macrophage adherence after the induction of monocyte differentiation. The assay was conducted using a human monocytic leukemia cell line, THP-1, treated with either 12-O-tetradecanoylphorbol 13-acetate or cytokines, such as tumor necrosis factor-? and interferon-?. This method is sensitive and easy to perform, especially in case of analyzing a large number of samples.

International Nuclear Information System (INIS)

Active oxygens produced by low-dose irradiation can induce the synthesis of proteins involved in the active oxygen reduction path and can activate the chemical self-defense mechanisms in vivo, which can alleviate the injuries caused by active oxygens themselves. The following findings suggests that it is not only by low-dose irradiation that can induce the responses described above but also by any physical and/or chemical stresses which can produce small amount of active oxygens in vivo. 1. X-irradiation with 0.5 Gy and/or water immersion and restraint induced heat shock protein (HSP)70 in rat stomach cells. HSP70 was also induced in adrenal cells by paraquat administration. 2. The SOD activity in pancreas of rat significantly increased by #gamma#-irradiation with 0.5 Gy. 0.5 Gy irradiation preceeding the alloxan administration significantly suppressed the increase in pancreatic lipid peroxides and in ...

Energy Technology Data Exchange (ETDEWEB)

Fetal nucleated cells within maternal blood represent a potential source of fetal genes obtainable by venipuncture. The authors used monoclonal antibody against the transferrin receptor (TIR) to identify nucleated erythrocytes in the peripheral blood of pregnant women. Candidate fetal cells from 19 pregnancies were isolated by flow sorting at 12 1/2-17 weeks gestation. The DNA in these cells was amplified for a 222-base-pair (bp) sequence present on the short arm of the Y chromosome as proof that the cells were derived from the fetus. The amplified DNA was compared with standardized DNA concentrations. In the case of the female fetus, DNA prepared from samples at 32 weeks of gestation and cord blood at delivery also showed the presence of the Y chromosomal sequence, suggesting Y sequence mosaicism or translocation. In 10/12 cases where the 222-bp band was absent, the fetuses were female. Thus, they were ...

International Nuclear Information System (INIS)

The cytotoxicity of 15-nm and 46-nm silica nanoparticles was investigated by using crystalline silica (Min-U-Sil 5) as a positive control in cultured human bronchoalveolar carcinoma-derived cells. Exposure to 15-nm or 46-nm SiO_2 nanoparticles for 48 h at dosage levels between 10 and 100 #mu#g/ml decreased cell viability in a dose-dependent manner. Both SiO_2 nanoparticles were more cytotoxic than Min-U-Sil 5; however, the cytotoxicities of 15-nm and 46-nm silica nanoparticles were not significantly different. The 15-nm SiO_2 nanoparticles were used to determine time-dependent cytotoxicity and oxidative stress responses. Cell viability decreased significantly as a function of both nanoparticle dosage (10-100 #mu#g/ml) and exposure time (24 h, 48 h, and 72 h). Indicators of oxidative stress and cytotoxicity, including total reactive oxygen species (ROS), glutathione, malondialdehyde, and lactate dehydrogenase, were ...

Science.gov (United States)

A 33-year-old male of proven fertility suffered six attacks of malaria while resident in an African country. For this he received anti-malarial drugs. Semen analysis performed after the fourth attack, and repeated during the following 2 years after his return to Israel, revealed severe oligozoospermia, necrozoospermia and occasionally even azoospermia. Immunological examination of the patient revealed an inverse ratio of T-cell subsets and mast cell degranulation in response to palludrin. Twenty-five months after the last attack of malaria a significant improvement was found in semen quality and there was an increase in the ratio of T-helper to T-suppressor cytotoxic cells. These observations indicate that although malaria and its treatment may affect spermatogenesis, recovery may be expected eventually. PMID:3500921

Energy Technology Data Exchange (ETDEWEB)

To study the regulation of adipose tissue lipoprotein lipase (LPL) in human adipocytes, omental adipose tissue was obtained from healthy subjects and digested in collagenase. The isolated adipocytes thus obtained were suspended in Medium 199 and cultured at 37 degrees C. Cell viability was demonstrated in adipocytes cultured for up to 72 h by constancy of cell number, cell size, trypan-blue exclusion, and specific /sup 125/I-insulin binding. In addition, chloroquine induced an increase in cell-associated /sup 125/I-insulin at 24, 48, and 72 h after preparation. Thus, isolated adipocytes retained their ability to bind, internalize, and degrade insulin. LPL was measured as activity secreted into the culture medium (CM), released from cells by heparin (HR), and extracted from cell digests. A broad range of heparin concentrations produced a ...

British Library Electronic Table of Contents (United Kingdom)

Dysregulation of intracellular Ca2+ homeostasis is associated with various pathological conditions and arrhythmogenesis of the heart. The objective of this study was to investigate the effects of an acute increase in intracellular Ca2+ concentration ([Ca2+]i) on the electrophysiology of ventricular myocytes by mimicking intracellular Ca2+ overload. The [Ca2+]i was clamped to either a controlled (65?100 nmol L?1) or increased (1 ?mol L?1) level. The transmembrane action potentials and ionic currents were recorded using whole-cell patch clamp techniques. We found that the acute increase in [Ca2+]i shortened the action potential duration, reduced the action potential amplitude, maximum depolarization velocity and resting membrane potential, caused delayed after-depolarizations (DADs), and tri...

British Library Electronic Table of Contents (United Kingdom)

Abstract Septins are highly conserved cytoskeletal GTP-binding proteins implicated in numerous cellular processes from apoptosis to vesicle trafficking. Septins have been associated with leukemia and solid tumor malignancies, including breast, ovarian, and prostate. We previously reported that high SEPT9_i1 expression in human mammary epithelial cell lines (HMECs) led to malignant cellular phenotypes such as increased cell proliferation, invasiveness, motility, and genomic instability. Our goal here was to better understand how SEPT9_i1 expression might contribute to genomic instability and malignant progression. First, we confirmed that even transient expression of SEPT9_i1 was sufficient to increase aneuploidy in HMECs. We then analyzed SEPT9_i1 by immunoprecipitation and immunofluoresce...

Science.gov (United States)

We hypothesize that the mushroom-derived active compound may be a potential strategy for increasing survival in response to influenza virus (H1N1) infection through the stimulation of host innate immune response. The validity of the hypothesis can be tested by immune response to influenza infection as seen through survival percentage, virus clearance, weight loss, natural killer cell cytotoxicity, Tumor Necrosis Factor-? (TNF-?) and Interferon-gamma (IFN-?) levels, lytic efficiency in the spleens of mice and inducible nitric oxide synthase mRNA expressions in RAW 264.7 murine macrophage cells. The hypothesis may improve people's quality of life, reduce the medical cost of our healthcare system and eliminate people's fears of influenza outbreak. PMID:21660092

International Nuclear Information System (INIS)

Exposures from most natural and artificial sources, with the exception of those from medical radiology, are received at average dose rates of only a few microsieverts a day. Such risks as may be caused by these exposures are most unlikely to be determined with precision directly by epidemiological studies of populations exposed at these low rates. They may, however, be reliably inferred from the observed risks of exposure to rather larger doses delivered at higher dose rates in the light of the increasing knowledge of the phenomena involved in the initial cellular damage, the extent to which such damage is incorrectly repaired, and the processes which intervene between the genetic or other harm to cells and the likelihood of its final expression in inherited abnormality, in cancer development, or in defective foetal or embryonic growth. Current studies are of great importance, therefore, in examining the circumstances in which coding sections ...

Energy Technology Data Exchange (ETDEWEB)

The importance of cellular dosimetry in both diagnostic and therapeutic nuclear medicine is becoming increasingly recognized. Experimental range-energy relations for electrons and alpha particles, along with derived geometric reduction factors, are used to calculate cellular absorbed fractions for these radiations. The resulting absorbed fractions are employed to calculate cellular S-values for several radionuclides. Cellular absorbed fractions for monoenergetic electron sources with energies ranging from 0.1 keV to 1 MeV, distributed uniformly in the source region, are calculated for several target {l_arrow} source combinations including cell{l_arrow}cell, cell{l_arrow}cell surface, nucleus{l_arrow}nucleus, nucleus {l_arrow}cytoplasm and nucleus {l_arrow}cell surface. Similar data are also provided for monoenergetic alpha particle sources with energies ranging from 3 to 10 MeV. S-values are also ...

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pT181 is a naturally-occurring 4437 basepair (bp) plasmid isolated from Staphylococcus aureus which encodes inducible resistance to tetracycline (Tc). The DNA sequence data has identified three open reading frames (ORFs). The largest ORF B, has been found to be responsible for the Tc resistance phenotype of pT181. Since most Tc resistance systems appear to be regulated by an effector protein and a repressor protein, several Bal 31 deletion mutants of pT181 were constructed and analyzed in an effort to identify the elements involved in Tc resistance. Two transcomplementing groups of mutants were identified within the tet gene. The mechanism of Tc resistance was studied by assaying the accumulation of (7-/sup 3/H) Tc by Tc sensitive cells, and uninduced and induced pT181-containing cells. A sharp decrease in accumulation of the drug after an initial increase was observed in Tc induced pT181-containing ...

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The effect of the heavy particle irradiation on cell survival is different from that of X-ray irradiation. In Japan, heavy particles will be applied to cancer patients in the near future. This study was performed to determine the effect that carbon particle irradiation exerts to human monolayer cells in vitro, in comparison with the effect of 200 kVp X-ray. Two human cell lines, HeLaS3 and RMUG, were used. The irradiation was carried out by the RIKEN ring cyclotron and 200 kVp X-ray. The experimental procedure is explained. Also split dose experiment was carried out by applying equally divided doses at intervals of 2 - 4 hours. The Bragg curve of 135 MeV/n carbon beam through the lucite plates with different thickness is given. Thus the different LETs were obtained. The survival curves for 200 kVp X-ray and the various LETs of carbon beam are shown. The curves became steeper, and Do values decreased with ...

UK PubMed Central (United Kingdom)

BackgroundAdipokines, e.g. TNFα, IL-6 and leptin increase insulin resistance, and consequent hyperinsulinaemia influences breast cancer progression. Beside its mitogenic...Full Text Available

International Nuclear Information System (INIS)

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like ...

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The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.

UK PubMed Central (United Kingdom)

A recent clinical trial of a T-cell-based AIDS vaccine delivered with recombinant adenovirus type 5 (rAd5) vectors showed no efficacy in lowering viral load and was associated with increased risk of...Full Text Available

UK PubMed Central (United Kingdom)

Type II diabetes mellitus (T2DM) is often accompanied by non-alcoholic steatohepatitis (NASH) and associated with hypercholesterolemia, i.e. increased levels of plasma low-density...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We investigated the effect of irradiation on the kinetic characteristics of amino acid and glucose transport, and the effect on the activity of the cell membrane-bound enzyme 5'-nucleotidase and on the receptor-mediated stimulation of cyclic adenosine monophosphate synthesis by prostaglandin E1. Irradiation inhibited the sodium-dependent amino acid transport by a reduced binding of the amino acid to the transport unit. The transport of glucose, which appeared to be a sodium-independent process, was temporarily stimulated by increased maximal velocity of the transport. No effect was found on the binding to the transport unit. Irradiation increased the 5'-nucleotidase activity and decreased the prostaglandin E1-stimulated cyclic adenosine monophosphate synthesis 48 h after exposure to 20 Gy. It is concluded that irradiation decreases sodium-dependent transport by impairment of the transport unit, does not ...

CERN Document Server

Heterogeneous base stations (e.g. picocells, microcells, femtocells and distributed antennas) will become increasingly essential for cellular network capacity and coverage. Up until now, little basic research has been done on the fundamentals of managing so much infrastructure -- much of it unplanned -- together with the carefully planned macro-cellular network. Inter-cell coordination is in principle an effective way of ensuring different infrastructure components behave in a way that increases, rather than decreases, the key quality of service (QoS) metrics. The success of such coordination depends heavily on how the overhead is shared, and the rate and delay of the overhead sharing. We develop a novel framework to quantify overhead signaling for inter-cell coordination, which is usually ignored in traditional 1-tier networks, and assumes even more importance in multi-tier heterogeneous cellular ...

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to ...

British Library Electronic Table of Contents (United Kingdom)

Cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) is provoked by injury to intrahepatic bile ducts and the progression of hepatic necrosis requires the procoagulant protein tissue factor (TF) and extrahepatic cells including neutrophils. Recent studies have shown that myeloid cell TF contributes to neutrophil activation. We tested the hypothesis that myeloid cell TF contributes to neutrophil activation in ANIT-treated mice. TF activity in liver homogenates increased significantly in TF^f^l^o^x^/^f^l^o^x mice treated with ANIT, but not in TF^f^l^o^x^/^f^l^o^x/LysMCre mice (TFD^M^y^e^l^o^i^d mice), which have reduced TF expression in monocytes/macrophages and neutrophils. Myeloid cell-specific TF deficiency did not alter expression of the chemokines KC or MIP-2 but redu...

International Nuclear Information System (INIS)

CBA/Ca mice were infected by either the intravenous or intraperitoneal route with Mycobacterium microti and the subsequent changes in local macrophage populations examined. Following infection, the number of macrophages increased and they showed greater expression of both MHC Class II molecules. This response was not dependent on viability of the mycobacteria, in contrast to reports with other microorganisms such as Listeria. Studies in sublethally irradiated mice indicated that persistent antigen could give rise to a response after a period of host recovery which was radiation dose dependent. This procedure also highlighted differences in the regulation of different murine class II antigens in vivo, as seen by delayed re-expression of I-E antigens. Macrophage accessory cell function, as assessed by an in vitro T cell proliferation assay, correlated with Ia expression after fixation, but not after indomethacin treatment; ...

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Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Sam68 (Src-associated protein in mitosis 68-kDa) is a multifunctional protein, known to govern cellular signal transduction, transcription, RNA metabolism, proliferation, apoptosis, and HIV-1 replication. Although intrinsic mechanisms that modulate Sam68 function are beginning to emerge, the regulatory events contributing to its expression remain elusive. We previously reported that heat shock protein-22 (Hsp22) antagonizes Sam68 function in rev-response element (RRE)-mediated gene expression. We now demonstrate that Sam68 levels correlate inversely with Hsp22 in a variety of cells, including U87, Jurkat, 293T, and U-937. In U87 glioblastoma cells, which contained high levels of Hsp22 than other cell lines tested, Hsp22 knockdown dramatically increased both Sam68 mRNA and protein,...

Energy Technology Data Exchange (ETDEWEB)

A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) assay that ...

British Library Electronic Table of Contents (United Kingdom)

Cyclothiazomycin B1 (CTB1) is an antifungal cyclic thiopeptide isolated from the culture broth of Streptomyces sp. HA 125-40. CTB1 inhibited the growth of several filamentous fungi including plant pathogens along with swelling of hyphae and spores. The antifungal activity of CTB1 was weakened by hyperosmotic conditions, and hyphae treated with CTB1 burst under hypoosmotic conditions, indicating increased cell wall fragility. CTB1-sensitive fungal species contain high levels of cell wall chitin and/or chitosan. Unlike nikkomycin Z, a competitive inhibitor of chitin synthase (CHS), CTB1 did not inhibit CHS activity. Although CTB1 inhibited CHS biosynthesis, the same result was also obtained with a non-specific proteins inhibitor, cycloheximide, which did not reduce cell wall rigidity. These ...

Energy Technology Data Exchange (ETDEWEB)

The authors have found that heat-inactivated serum (57/sup 0/C for 1 hour) from normal chickens reduces the proliferation of mitogen-stimulated chicken and murine splenocytes as well as some transformed mammalian lymphoblastoid cell lines. Greater than a 50% reduction in /sup 3/H-thymidine incorporation was observed when concanavalin A (Con A)-activated chicken splenocytes that were cultured in the presence of 10% autologous or heterologous serum were compared to mitogen-stimulated cells cultured in the absence of serum. Normal chicken serum (10%) also caused greater than 95% suppression of /sup 3/H-thymidine incorporation by bovine (EBL-1 and BL-3) and gibbon ape (MLA 144) transformed lymphoblastoid cell lines. The only cell line tested that was not inhibited by chicken serum was an IL-2-dependent, murine cell line. Chicken serum also inhibited both /sup 3/H-thymidine incorporation ...

Energy Technology Data Exchange (ETDEWEB)

The performance of two-cell planar solid oxide fuel cell stacks using coal syngas, with and without hydrogen sulfide (H{sub 2}S), was studied. All cells were tested at 850 C with a constant current load of 15.2 A (current density of 0.22 A cm{sup -2} per cell) and 30% fuel utilization. The H{sub 2}S injection immediately and significantly affected the power degradation of the stack system regardless of the carrier fuel. Results for the test with only H{sub 2} and N{sub 2} in the presence of H{sub 2}S (119-120 ppm) indicated that the power decay and area-specific resistance (ASR) degradation values were lower than those for the tests where simulated syngas containing CO and increased water content was used. The results indicate that contact points in the stack contributed to the power degradation of the system. Other factors, including contamination from the upstream fuel gas tubing, ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Iodine concentrates in gastric tissue and may act as an antioxidant for the stomach. We previously showed that self-reported goiter was associated with significantly increased risk of gastric noncardia adenocarcinoma (GNCA) and nonsignificantly increased risks of gastric cardia adenocarcinoma (GCA) and esophageal squamous cell carcinoma (ESCC) in a prospective case-cohort study in a high-risk population in China. Negatively correlated with iodine levels, serum thyroglobulin (Tg) is a more sensitive biomarker of iodine deficiency than goiter. Our study aimed to determine whether baseline serum Tg was also associated with development of GNCA, GCA and ESCC in the same cohort, the Linxian General Population Nutrition Intervention Trial. Sera from -200 subjects of each case type and 40...

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The processes of lung growth, injury, and repair are characterized by alterations in fibroblast synthesis and interstitial distribution of extracellular matrix components. Transforming growth factor beta (TGF-beta), which is postulated to play a role in modulating lung repair, alters the distribution of several matrix components such as collagen and fibronectin. We studied the effect of TGF-beta on the synthesis and distribution of the various glycosaminoglycans (GAGs) and whether these effects may explain its role in lung repair. Human diploid lung fibroblasts (IMR-90) were exposed to various concentrations of TGF-beta (0-5 nM) for variable periods of time (0-18 h). Newly synthesized GAGs were labeled with either (3H)glucosamine or (35S)sulfate. Individual GAGs were separated by size exclusion chromatography after serial enzymatic and chemical digestions and quantitated using scintillation counting. There was a dose-dependent increase in total GAG synthesis with ...

Energy Technology Data Exchange (ETDEWEB)

A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including icosapentanoic acid. Culture under high temperatures or normal pressure ...

British Library Electronic Table of Contents (United Kingdom)

Abstract The term -stem cell- most commonly refers to embryonic stem cells, particularly in the lay media; however, it also describes other cell types. A stem cell represents a cell of multi-lineage potential with the ability for self-renewal. It is now clear that the plasticity and immortality of a given stem cell will depend on what type of stem cell it is, whether an embryonic stem cell, a fetal-placental stem cell or an adult stem cell. Stem cells offer great promise as cell-based therapies for the future. With evolving technology, much of the socio-political debate regarding stem cells can now be avoided.

Science.gov (United States)

The role of intracellular Ca2+ (Ca2+i) on hematopoiesis was investigated in long term bone marrow cultures using cytokines and agonists of P2 receptors. Cytokines interleukin 3 and granulocyte/macrophage colony stimulator factor promoted a modest increase in Ca2+i concentration ([Ca2+]i) with activation of phospholipase Cgamma, MEK1/2, and Ca2+/calmodulin kinase II. Involvement of protein kinase C was restricted to stimulation with interleukin 3. In addition, these cytokines promoted proliferation (20 times) and an increase in the Gr-1(-)Mac-1+ population with participation of gap junctions (GJ). Nevertheless ATP, ADP, and UTP promoted a large increase in [Ca2+]i, moderate proliferation (6 times), a reduction in the primitive Gr-1(-)Mac-1(-)c-Kit+ population, and differentiation into macrophages without participation of GJ. It is likely that Ca2+i participates as a regulator of hematopoietic signaling: moderate ...

Energy Technology Data Exchange (ETDEWEB)

Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into byproducts having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that spark-decomposed SF/sub 6/ produces cell death, and the extent of cell killing increases with increasing spark energy. Chemical analysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and byproducts, but biological testing of individual or byproduct mixtures has indicated that these major decomposition products do not contribute, in a significant fashion, to the cell lethality seen in our assays. ...

International Nuclear Information System (INIS)

This study was performed to evaluate the diagnostic usefulness of double-phase Tc-99m MIBI parathyroid scintigraphy with single photon emission computed tomography (SPECT) in patients with hyperparathyroidism. We also evaluated the relationship between Tc-99m MIBI uptake and oxyphil cell contents in parathyroid glands. The subjects were 28 parathyroid glands of 10 patients who underwent Tc-99m MIBI parathyroid scintigraphy and parathyroidectomy for clinically suspected hyperparathyroidism. Early and delayed pinhole images were obtained at 15 minutes and 2 hours after injection of Tc-99m MIBI, and SPECT images were followed. The weight and oxyphil cell contents of parathyroid tissue were obtained from pathologic specimen, and the scintigraphic findings were compared with histopathology. In surgical histopathology, 6 parathyroid adenomas and 9 parathyroid hyperplasias were confirmed. The sensitivity, specificity, and positive predictive value of ...

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Two window layer materials, Al{sub 0.51}In{sub 0.49}P (E{sub g} = 2.3 eV) and Ga{sub 0.51}In{sub 0.49}P (E{sub g} = 1.88 eV) were compared for gas-source and solid-source MBE grown GaAs and Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} (E{sub g} = 1.55 eV) solar cells. Due to the wider band-gap of Al{sub 0.51}In{sub 0.49}P, the increased spectral response was observed for both GaAs and Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} material based solar cells. In the case of the GaAs cells, the short-circuit current density was observed to increase from 32.5 mA/cm{sup 2} to 34.4 mA/cm{sup 2} with the Al{sub 0.51}In{sub 0.49}P window layer at AM0. Similar improvement was observed for the Ga{sub 0.84}In{sub 0.16}As{sub 0.68}P{sub 0.32} solar cells.

Science.gov (United States)

Total potassium was assayed in 150 normal weight and obese females (cervical carcinoma-52, endometrial carcinoma-25 and breast cancer-73) by measurements of 40K spontaneous radiation in a low-background chamber. Control group included 30 healthy and 25 obese females. Computations of body cell and extracellular mass and fat were carried out on the basis of the said measurements. Extracellular fluid volume was measured in 38 patients by X-ray fluorescence method using sodium bromide. The results pointed to a body cell mass deficit matched by increased extracellular mass due to a higher fat level in patients with breast, endometrial and cervical carcinoma. The said correlation was particularly pronounced in obese patients. The beneficial effect of treatment was more often observed in patients with normal body weight. PMID:3739295

International Nuclear Information System (INIS)

Surface energy of III-V semiconductors ended by (110) clean surface and surface covered by atomic monolayer of aluminium, copper and sulfur has been calculated. We have used the Greens-function technique based on the scheme of linear muffin-tin orbitals in the atomic sphere approximation (LMTO-ASA) for the crystal potential and width the local density approximation (LDA) for electrons. Two types of coverage are considered: full monolayer with two additional atoms per two-dimensional unit cell and half monolayer with one additional atom per unit cell. Full monolayer of metallic atoms increases the surface energy. Cu atoms lead to greater destabilization than Al atoms. Sulfur atoms stabilize (110) surface for all considered compounds. (author)

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Investigations of cadmium toxicity to microorganisms are now more concerned with the interactions of cadmium with different environmental factors and other metals. The interactions are complex and have not been thoroughly studied yet. Metal interactions may assume the form of synergism characterized by increase in toxicity, but also of antagonism in which one metal reduces the toxicity of another. Apart from cadmium interactions with such toxic metals as mercury and lead, interactions of cadmium with the essential trace elements seem to be very interesting because it has been assumed that algal cells take up cadmium by the system transporting these elements. A previous study showed that cadmium transport into Stichococcus bacillaris cells was inhibited by Mn/sup 2 +/ ions. Thus, it can be supported that there exist some possibilities of using those ions antagonistic to cadmium as counterposition. Showing those possibilities ...

CERN Document Server

We have developed a simulation code with the techniques which enhance both spatial and time resolution of the PM method for which the spatial resolution is restricted by the spacing of structured mesh. The adaptive mesh refinement (AMR) technique subdivides the cells which satisfy the refinement criterion recursively. The hierarchical meshes are maintained by the special data structure and are modified in accordance with the change of particle distribution. In general, as the resolution of the simulation increases, its time step must be shortened and more computational time is required to complete the simulation. Since the AMR enhances the spatial resolution locally, we reduce the time step locally also, instead of shortening it globally. For this purpose we used a technique of hierarchical time steps (HTS) which changes the time step, from particle to particle, depending on the size of the cell in which particles reside. ...

British Library Electronic Table of Contents (United Kingdom)

The development of calcium sulfate dihydrate (gypsum) mineral scale in reverse osmosis (RO) membrane desalting was investigated by direct real-time observation of crystal growth. Gypsum scaling studies were conducted in a specially modified plate-and-frame reverse osmosis cell fitted with an optical window, with dark-field membrane lighting arrangement within the membrane cell to enhance crystal boundaries and allow recording of digital surface images magnified through an optical microscope. The evolution of the surface number density (SND) of gypsum crystals resembled a sigmoidal population growth process with an increasing rate of crystal formation at higher solution supersaturation (with respect to gypsum) at the membrane surface. The rate of formation of new crystals declined as the su...

British Library Electronic Table of Contents (United Kingdom)

In recent years, increased attention has been focused on the use of lasers in different fabrication steps of solar cells, in particular laser doping to form emitter and/or selective emitter. In this method the laser energy is used to melt silicon, allowing the diffusion of dopant atoms to occur in the liquid phase. The main advantage of this method is the localised nature of the laser beam, which melts and diffuses a limited area without heating the bulk, therefore reducing the possible degradation associated with high temperature processes. At the University of New South Wales a novel laser doping method was developed, which combines the formation of the selective emitter with a self-aligned metallisation pattern. Despite achieving high efficiencies, concerns arose regarding the adhesion ...

British Library Electronic Table of Contents (United Kingdom)

Heavily doped emitters with low saturation current density are of particular interest for selective emitter solar cells. These emitters can be obtained by laser doping through the phosphosilicate glass layer formed after thermal diffusion from POCl3 gas. The experimental results show that in contrast to purely POCl3 furnace-diffused emitters, the saturation current density of laser-doped emitters does not increase linearly as sheet resistance decreases, but rather features two distinct regimes. In one of these regimes, the saturation current density is found to decrease as the sheet resistance decreases, reaching values lower than those of furnace emitters. This peculiar behaviour was explained by both qualitative analysis and numerical simulations.

British Library Electronic Table of Contents (United Kingdom)

Research and bioethical policies are increasingly seen to facilitate, rather than to impede, scientific progress. Bioethical structures, nonetheless, often fail to account for or to shape the specific social surrounds in which scientific research is conducted. In Taiwan, a perceived shortage in human biological donations threatens to hamper stem cell research progress. This paper considers the stalled national biobank project and the lack of a reliable embryo supply for stem cell research, and suggests that one must look beyond regulatory structures in seeking explanations for such shortages. Specific aspects of Taiwan's democratization and social changes combine with problematic relations between patients and physicians to shape the terrain upon which human biologicals are given or withhe...

British Library Electronic Table of Contents (United Kingdom)

An appropriate mathematical model can help researchers to simulate, evaluate, and control a proton exchange membrane fuel cell (PEMFC) stack system. Because a PEMFC is a nonlinear and strongly coupled system, many assumptions and approximations are considered during modeling. Therefore, some differences are found between model results and the real performance of PEMFCs. To increase the precision of the models so that they can describe better the actual performance, optimization of PEMFC model parameters is essential. In this paper, an artificial bee swarm optimization algorithm, called ABSO, is proposed for optimizing the parameters of a steady-state PEMFC stack model suitable for electrical engineering applications. For studying the usefulness of the proposed algorithm, ABSO-based results...

Energy Technology Data Exchange (ETDEWEB)

ABSTRACT-Here we identify release of annexin A2 into the culture medium in response to low dose X-ray radiation exposure and establish functional linkages to an established paracrine factor-mediated anchorage-independent growth response. Using a standard bicameral coculture model, we observe that annexin A2 levels associated with non-irradiated neighboring cells seeded in the lower chamber (annexin A2 silenced [shRNA] JB6 cells) are increased upon coculture with irradiated (10-50 cGy) JB6 cells seeded in the upper chamber, relative to coculture with sham exposed JB6 cells seeded in the upper chamber, suggesting that annexin A2 released into the medium is capable of communicating in a paracrine fashion. Using a previously established coculture model, we observed that the paracrine factor-mediated anchorage-independent growth response to low dose X-ray radiation is markedly reduced ...

International Nuclear Information System (INIS)

An analogue of hGH isolated from plerocercoids of the tapeworm Spirometra mansonoides displaces ["1"2"5I]hGH from its receptors in rabbit, rat, and hamster liver membranes. Biologically, plerocercoid growth factor (PGF) is more similar to hGH than to other mammalian GH's but has not been shown to bond human cells. Receptors specific for hGH have been described on cultured human lymphocytes (IM-9). In this study, the authors compared the binding of PGF and hGH in IM-9 cells and in rabbit hepatic membranes. IM-9 lymphocytes (12 x 10"6 cells/tube) were incubated with ["1"2"5I]hGH and increasing concentrations of hGH (ng/ml) or PGF (serial dilutions) for 90 min at 30"0 C. Specific binding (B_0 - NSB) was determined for each dose of hGH or PGF and the binding curves were analyzed by logit-log regression. The results show that PGF displaced ["1"2"5I]hGH from human cells in a dose ...

Energy Technology Data Exchange (ETDEWEB)

Biosorption is presented as an alternative choice to traditional physicochemical means for removing toxic metals from groundwater and wastewaters. Removal of lead (Pb) from solutions was studied using Escherichia coli (parental) and Vitreoscilla hemoglobin (VHb)-expressing E. coli (transformed) cells. Pb biosorption was increased in bacterial hemoglobin-expressing E. coli cells grown in Luria broth B containing different concentrations of Pb{sup 2+}. The maximum Pb{sup 2+} biosorption of transformed and parental cells was determined to be 612 and 370 {mu}g Pb/g biomass, respectively. The inhibitory effect of Pb{sup 2+} on the parental strain was determined at 10 ppm. However, in transformed cells, Pb{sup 2+} was lethal at 100 ppm. The optimum aeration required for the transformed cells was lower than that for the parental strain on a growth yield basis. A linear ...

Energy Technology Data Exchange (ETDEWEB)

The hypothesis that accumulation against sizable chemical gradients of free (non-phosphorylated) 2-deoxy-D-glucose (2dGlc) in isolated rat adipocytes results from an intracellular compartmentation of free hexose was investigated. Cells exposed to 20 ..mu..g/ml digitonin for 10' demonstrated an increased plasma membrane permeability indexed by increased L-glucose entry rates and cellular (presumably cytosolic) protein and K/sup +/ loss. Functional integrity of intracellular organelles was indicated by the ability of the cells to support ATP-driven /sup 45/Ca/sup 2 +/-uptake. Equilibrium 3-O-methylglucose (3-O-MG, a non-accumulated hexose) levels were unaffected. These data suggest a specific permeabilizing action of digitonin at the plasma membrane having no effect on intracellular organelles or passively distributed solutes. Upon addition of digitonin, free 2dGlc fell from 66.5 +/- 8.9 to 7.4 ...

Energy Technology Data Exchange (ETDEWEB)

The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on grounds of economic efficiency and environmental quality. The fuel cell program is ...

Energy Technology Data Exchange (ETDEWEB)

Using a coplanar, end-mounted antenna as a baseline, various configuration trades were performed to select a preferred solid state concept. The increase in efficiency that could be realized by use of multi bandgap solar cells, either with klystron or solid state antenna was evaluated. Satellite configurations were developed to exploit the sandwich antenna concept wherein solar cells are located on one side of the antenna panel and solid state dc/RF converters on the other side. These concepts entailed various primary and secondary reflector arrangements for directing solar energy to the solar cell side of the antenna with higher concentration ratios than used on the coplanar configurations. Operations analysis included development of a satellite construction scenario, a concept for the SCB, a top-level satellite construction operation, construction operation, construction timelines and crew sizes, mass ...

Energy Technology Data Exchange (ETDEWEB)

On-board reforming of liquid fuels to hydrogen for use in proton exchange membrane (PEM) fuel cell electric vehicles (FCEVs) has been the subject of numerous investigations. In many respects, liquid fuels represent a more attractive method of carrying hydrogen than compressed hydrogen itself, promising greater vehicle range, shorter refilling times, increased safety, and perhaps most importantly, utilization of the current fuel distribution infrastructure. The drawbacks of on-board reformers include their inherent complexity [for example a POX reactor includes: a fuel vaporizer, a reformer, water-gas shift reactors, a preferential oxidation (PROX) unit for CO cleanup, heat exchangers for thermal integration, sensors and controls, etc.], weight, and expense relative to compressed H{sub 2}, as well as degraded fuel cell performance due to the presence of inert gases and impurities in the reformate. Partial oxidation (POX) of ...

Science.gov (United States)

Endoreduplication represents a cell cycle variant during which multiple rounds of DNA replication occur without subsequent chromosome separation and cytokinesis, resulting into a cellular increase of the DNA content. Although the DNA ploidy level of cells is controlled by external stimuli such as light, currently limited knowledge is available on how environmental signals regulate the endoreduplication cycle at the molecular level. Previously, we have demonstrated that the conversion from the mitotic cell cycle into an endoreduplication cycle is mediated by the atypical E2F transcription factor DEL1 that operates as a repressor of endocycle onset. Here, we identified DEL1 as a transcriptional target of the classical E2Fb and E2Fc transcription factors that antagonistically control DEL1 transcript levels through competition for a single E2F cis-acting binding site. Correspondingly with the reported ...

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Ependymal cells line the cerebral ventricles forming the interface that separates the cerebrospinal (CSF) and interstitial fluids (ISF). Extracellular molecules move between ependymal cells, whereas lipid soluble molecules pass both between and through cells. We measured the transfer of tritiated water (TOH) from CSF to blood across the ependymal and capillary interfaces by ventriculocisternal (VC) steady-state tissue clearance. Adult cats anesthetized with pentobarbital sodium underwent VC perfusion with the extracellular marker (/sup 14/C)sucrose and TOH added to the artificial CSF. Brain tissue was analyzed for depth of penetration of the isotopes into periventricular gray matter. We found that TOH distribution space was lower than expected from water content measurements, whereas sucrose space was normal. Using VC steady-state equations we calculated an ependymal permeability that was similar to the permeability of the ...

Energy Technology Data Exchange (ETDEWEB)

This invention relates to the production method of composite electrode substrate for fuel cell. An impermeable material is used for edge sealant. The sealant is put in the clearance between two electrodes consisting of porous carbon material via thermoplastic resin sheet, and heated while being pressed. This production method increases the adherence between the porous carbon bodies and reduces the contact resistivity at the joint interface. Consequently, it becomes possible to produce the composite electrode for fuel cell without separator, resulting in simplification of assembly work, weight reduction, and downsizing. The preferable porous carbon body is made from shrinkage-treated fiber. After sheet forming, the thermosetting resin is impregnated, and then it is burnt to carbonization. Or mixed sheet of rayon and acrylic fiber is laminated to be heated and pressed without impregnating the resin. The pressed resin is then ...

International Nuclear Information System (INIS)

Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active area is augmented. The SOFC stack efficiency can be maximized by reducing the steam generation while ...

International Nuclear Information System (INIS)

Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca"2"+ channel (SOCC)-mediated Ca"2"+ entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, ...

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3T3 - L1 cells can be induced to differentiate by exposing cell culture to a medium containing 3-isobutyl-1-methyl-xanthine together with insulin and dexamethasone. They have observed that oxalomalate (OMA) which inhibits aconitase thus blocking the citric cycle, also favours differentiation to adipocytes leading to fatty acids accumulation and increased synthesis of specific proteins. They compared the effects of 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone and OMA on the steady-state levels of mRNA of c / EBP, H-ferritin and aconitase / IRE-BP. OMA does not affect the steady-state mRNA amount of C / EBP, H-ferritin and aconitase / IRE-BP but the 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone mixture is able to induce a five-fold increase of mRNA levels for aconitase / IRE-BP. This is the first finding correlating iron metabolism to adipocyte differentiation. Further studies will clarify a ...

British Library Electronic Table of Contents (United Kingdom)

This study describes the role of "inflammatory" oxidized (Ox) phospholipids in regulation of rahU (PA0122) expression and biofilm formation in Pseudomonas aeruginosa (383) wild type (rahU+) and rahU mutant (rahU-) strains. Functional analysis of RahU protein from P. aeruginosa in presence of Ox-phospholipids show: (a) LysoPC modulates RahU gene/and protein expression in rahU+ cells; (b) rahU promoter activity is increased by lysoPC and inhibited by PAPC, Ox-PAPC and arachidonic acid; the latter inhibitory effect can be reversed by lysoPC, which was enzymatically derived from PAPC; (c) biofilm formation increased in rahU- cells as compared to rahU+; and (d) inhibition of rahU promoter activity by PAPC and AA (but not lysoPC) showed significantly augmented biofilm formation in rahU+ but not ...

British Library Electronic Table of Contents (United Kingdom)

Epidemiological studies have revealed that butyrate and 17?-estradiol (E2) may decrease the incidence of colorectal cancer (CRC). In peripheral tissue, E2 can be produced locally by 17?-hydroxysteroid dehydrogenase 1 (HSD17B1) estrone (E1) reduction. Using quantitative real-time polymerase chain reaction and western blotting analysis, we found that sodium butyrate significantly upregulates HSD17B1 long and short transcripts and protein levels in HT29 and SW707 CRC cells. Chromatin immunoprecipitation analysis showed that upregulation of these transcript levels correlated with an increase in binding of Polymerase II to proximal and distal promoters of HSD17B1. Moreover, we observed that upregulation of HSD17B1 protein levels was associated with increased conversion of E1 to E2 in HT29 and S...

Science.gov (United States)

The three mammalian transforming growth factor (TGF)-? isoforms (TGF-?1, TGF-?2, and TGF-?3) differ in their putative roles in radiation-induced fibrosis in intestine and other organs. Furthermore, tissue specificity of TGF-? action may result from temporal or spatial changes in production and/or activation. The present study examined shifts in the cell types expressing TGF-? mRNA relative to TGF-? immunoreactivity and histopathological injury during radiation enteropathy development. A 4-cm loop of rat small intestine was locally exposed to 0, 12, or 21-Gy single doses of x-irradiation. Sham-irradiated and irradiated intestine were procured 2 and 26 weeks after irradiation. Cells expressing the TGF-?1, TGF-?2, or TGF-?3 transcripts were identified by in situ hybridization with digoxigenin-labeled riboprobes. Intestinal wall TGF-? immunoreactivity was measured using computerized image analysis, and structural radiation injury was assessed by ...

British Library Electronic Table of Contents (United Kingdom)

Although cognitive performance in humans and experimental animals can be improved by administering omega-3 fatty acid docosahexaenoic acid (DHA), the neurochemical mechanisms underlying this effect remain uncertain. In general, nutrients or drugs that modify brain function or behavior do so by affecting synaptic transmission, usually by changing the quantities of particular neurotransmitters present within synaptic clefts or by acting directly on neurotransmitter receptors or signal-transduction molecules. We find that DHA also affects synaptic transmission in mammalian brain. Brain cells of gerbils or rats receiving this fatty acid manifest increased levels of phosphatides and of specific presynaptic or postsynaptic proteins. They also exhibit increased numbers of dendritic spines on post...

International Nuclear Information System (INIS)

Increased levels of epidermal growth factor receptor have been reported in a variety of tumors, including pulmonary squamous cell carcinomas in man. The purpose of this study was to determine if increased levels of epidermal growth factor (EGFR) were present in lung tumors from Beagle dogs that had been exposed to "2"3"9PuO_2- Using immunohistochemical techniques, sections from 17 lung tumors were examined for the presence of EGFR. Seven of the tumors were strongly positive for EGFR; the remainder of the tumors and the normal lung sections were negative. The positive immunostaining could not be correlated with the histologic phenotype of the tumors. Work is in progress to determine the level of EGFR in preneoplastic, proliferative epithelial foci in the Iung. (author)

British Library Electronic Table of Contents (United Kingdom)

Moso bamboo (Phyllostachys pubescens) is widely distributed in the acid soil region of Southern China, where great potential of aluminum (Al) toxicity exists. To evaluate the Al tolerance of Moso bamboo, seed germination and root elongation were compared with two rice cultivars, and physical and physiological damages were examined under various levels of Al stress. Results showed that Moso bamboo seed germination was inhibited when Al concentration increased to 500 ?M, and the median lethal concentration was 2,000??M. Comparatively, the rice seed germination was not inhibited even at a concentration of 2,000??M Al. Aluminum accumulated mainly in the cell wall of root apices, and entered into protoplasts as treating time prolonged and/or Al concentration increased, which resulted in apoptos...

Science.gov (United States)

Adolescent exposure to anabolic androgenic steroids (AAS) alters the development and activity of the glutamate neural system in the latero-anterior hypothalamus (LAH) in hamsters (Mesocricetus auratus); that is, an important neural component of the adolescent AAS-induced aggressive response. In this article, we used retrograde tracing to investigate glutamate-specific alterations in the connections between the LAH and several other nuclei implicated in adolescent AAS-induced aggression. Briefly, hamsters were treated with AAS or sesame-oil control during adolescence and then microinjected with retrograde tracer into the medial amygdala (MeA), lateral septum (LS), or bed nucleus of the stria terminalis (BNST). Brains were then processed for vesicular glutamate transporter 2 (VGLUT2) and examined for AAS-induced changes in the number VGLUT2 cells containing retrograde tracer (VGLUT2/tracer) within the LAH. It is interesting to note that while aggressive AAS-treated ...

Energy Technology Data Exchange (ETDEWEB)

The thermal modeling of electrochemical batteries is today an integral part of the design and validation operations of new products. The Li-ion pair allows to increase the power density of batteries but leads to higher heat fluxes during charging-output cycles. Thus, the thermal control has become more crucial and requires the use of modeling. SAFT and TSR companies are involved in this approach and use the ESACAP software. This paper presents this software which uses a nodal method for the modeling of the coupled thermal and electrical processes that take place inside elementary cells and batteries. (J.S.)

International Nuclear Information System (INIS)

A survey is presented of the consequences of the irradiation of the population with ionizing radiation. There is an increased incidence of leukemia in irradiated population groups. Among the inhabitants of Hiroshima and Nagasaki maximum death of leukemia was observed in the years 1951 to 1952. The results are summed up of the observation of carcinoma of the breast, lungs and bronchi, bones, and carcinoma of the thyroid. The effect of radiation on experimental animals is described. It was found that the scatter of the dependence of the incidence of various types of cancer on the dose equivalent apparently reflects differences in the biological mechanism of this incidence and that a proportional relationship cannot be expected between the primary damage of cells during irradiation and the actual manifestation of the disease. (E.S.).

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This study was conducted to investigate the decomposition of three {gamma}-irradiated antibiotics (e.g., tetracycline, sulfamethazine, and lincomycin) and to compare the toxic effects on Daphnia magna, Vibrio fischeri, and Pseudokirchneriella subcapitata. The median cell growth inhibition concentrations (IC{sub 50}) of tetracycline, lincomycin, and sulfamethazine for P. subcapitata dramatically increased (e.g., toxicity decreased) after radiolysis. The results demonstrated that {gamma}-radiation treatment was efficient to decompose antibiotics and thereby their toxicity on P. subcaptitata remarkably decreased due to reduced parent compounds.

Energy Technology Data Exchange (ETDEWEB)

Our major goal of our work has been to develop and use NMR techniques to study how methanogenic archaebacteria deal with osmotic stress with the hope of providing insights into increasing the salt tolerance of other cells. The project has three main sections: (i) in vivo studies of methanogens; (ii) use of {sup l3}C- and {sup l5}N- labeled potential precursors and in vitro analyses of specific label uptake for elucidation of osmolyte dynamics and biosynthetic pathways of osmolytes in these organisms, and isolation of key biosynthetic enzymes; and (iii) collaborative studies on identification of organic solutes in other methanogens.

Environmental Research Database

DescriptionBoth wild and aquaculture reared abalone, mussels and other shellfish of commercial importance as a food resource to man can be afflicted by poisoning if they feed on toxic species of small single-celled planktonic marine algae. If humans consume these shellfish that have become intoxicated by HAB's, illness or even death may occur. HAB's occur world-wide, but some regions are more severely affected than others. The incidence of HAB's also appear to be on the increase globally, perhaps because o [continued...

DEFF Research Database (Denmark)

Udgivelsesdato: 2002-Mar

Science.gov (United States)

PMID:21290990

Energy Technology Data Exchange (ETDEWEB)

In order to gain an overall picture of the genetic effects of an increased level of background radiation it is necessary to study the results of protracted exposures to embryonic and immature germ-cell stages as well as to stages found in the mature organism. For this purpose, litters produced by female mice, kept in a 10 or 20 rad/day /sup 60/Co ..gamma..-irradiation field, were kept in the same fields from conception until about 60 days later, having absorbed doses of 526 and 1078 rad respectively. Tests on exposed female offspring showed them to be sterile. Eight weeks after removal from the gamma field, mean testis masses of males in the 20 rad/day series were only half normal but those receiving 10 rad/day were little affected. Frequencies of translocations in spermatocytes at diakinesis/metaphase I were only slightly increased in the exposed series, differences not being significant. Estimated rates of translocation ...

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Callus cultures derived from pith tissue of Nicotiana tobacum were grown on two media either under continuous illumination or in complete darkness. The first medium limited greening ability of callus grown in the light (3 milligrams per liter naphthalene acetic acid, 0.3 milligram per liter 2-isopentenylaminopurine, Murashige and Skoog salts, and 2% sucrose). The second medium encouraged chlorophyll synthesis (greening) though not shoot formation (0.3 milligram per liter naphthalene acetic acid; 0.3 milligrams per liter 2-isopentylaminopurine). To measure intracellular concentrations, calli were grown for 15 days on these standard media containing (U-/sup 14/C)sucrose. The dry weight proportions of the calli (as a fraction of fresh weight) and many metabolite concentrations nearly doubled in light-grown cells compared to dark-grown cells and increase 30 to 40% on low-auxin media relative to high-auxin media. Glutamine ...

International Nuclear Information System (INIS)

Purpose: Previous data suggest that the PKC? catalytic V5 (PKC?-V5) heptapeptide (HEPT) (FEQFLDI) binds HSP27 and blocks HSP27-mediated radio- or chemoresistance. Here we investigated further the in vivo function of the PKC?-V5 HEPT. Methods and Materials: Labeling of HEPT with Cy5.5 or fluorescein isothiocyanate was performed to evaluate in vitro or in vivo distribution of HEPT. A clonogenic survival assay, flow cytometry, and Western blotting of cleaved caspase-3 were performed to determine in vitro sensitization effects of HEPT plus ionizing radiation (IR) versus IR alone or those of HEPT plus cisplatin(Cis) versus Cis alone. A nude mouse xenografting system was also applied to detect in vivo sensitizing effects of HEPT. Results: HEPT efficiently bound to HSP27 and showed sensitization after combined treatment with IR versus treatment with Cis alone in NCI-H1299 lung carcinoma cells, with higher HSP27 expression, which was similar to that of combined treatment ...

International Nuclear Information System (INIS)

Full text: DNA rearrangement events leading to chromosomal aberrations are central to ionizing radiation-induced cell death. Although DNA double-strand breaks are probably the lesion that initiates formation of chromosomal aberrations, little is understood about the molecular mechanisms that generate and modulate DNA rearrangement. Examination of the sequences that flank sites of DNA rearrangement may provide information regarding the processes and enzymes involved in rearrangement events. Accordingly, we developed a method using inverse PCR that allows the detection and sequencing of putative radiation-induced DNA rearrangements in defined regions of the human genome. The method can detect single copies of a rearrangement event that has occurred in a particular region of the genome and, therefore, DNA rearrangement detection does not require survival and continued multiplication of the affected cell. Ionizing radiation-induced DNA ...

Science.gov (United States)

The transcriptional silencing of some cell cycle inhibitors and tumor suppressors, such as p16 and retinoic acid receptor beta(2), by DNA hypermethylation at CpG islands is commonly found in human oral squamous carcinoma cells. We examined the effects of the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza; 0.25 mg/kg body weight), all-trans retinoic acid (RA; given at 100 microg/kg body weight and 1 mg/kg body weight), and the combination of 5-Aza and the low-dose RA on murine oral cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO) in a mouse model. All the drug treatments were done for 15 weeks after a 10-week 4-NQO treatment. Mice in all drug treatment groups showed decreases in the average numbers of neoplastic tongue lesions. The combination of 5-Aza and RA effectively attenuated tongue lesion severity. Although all drug treatments limited the increase in the percentage of ...

Energy Technology Data Exchange (ETDEWEB)

Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, advanced batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity measurements. Phase components of the samples are dependent on cobalt concentration and synthesis pO{sub 2}. Total conductivity increases ...

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Changes in the phosphate metabolism of the transplanted SCCVII (squamous cell carcinoma VII) tumor were studied before and after irradiation using in vivo [sup 31]P-magnetic resonance spectroscopy (MRS). Phosphocreatine (PCr), [gamma]-, [alpha]-, [beta]-ATP, inorganic phosphate (Pi), phosphomonoester (PME), and phosphodiester (PDE) were detected in [sup 31]P-MR spectra of tumor tissues. The curve fitting method was employed for calculating each peak of [sup 31]P-MR spectra (PCr, [beta]-ATP, Pi, PME, PDE). The values of PCr, PCr/Pi, [beta]-ATP/Pi and pH decreased in proportion to the growth of tumor, whereas that of Pi, PME and PDE increased. But the changes of [beta]-ATP were minimal in degree. Based on the fact that the ratio of PCr/Pi highly correlated with tumor volume and showed the most remarkable change among various parameters, it might be the useful index for the tumor growth. Because the phospholipid metabolite PME was detected in the ...

KoreaScience (Korea)

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CERN Document Server

Applied and fundamental aspects of plant cell, tissue, and organ culture

International Nuclear Information System (INIS)

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The ...

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Both increased cell proliferation and {open_quotes}altered{close_quotes}CYP gene expression are prominent phenomena associated with liver tumor promotion by nongenotoxic carcinogen treatment. BRDU-labeled parenchymal nuclei were observed primarily in the periportal area of groups of rats, independent of nongenotoxic carcinogen treatment. Treatment with each of the 5 nongenotoxic carcinogens resulted in profound alterations in CPY gene expression at both the transcriptional and translational levels. Expression of CYP1A1, 1A1/2, 3A1, 2B1/2, and 4A immunoproteins demonstrated nongenotoxic carcinogen-specific patterns in both magnitude and zonal distribution. In agreement with the CYP immunoprotein data, treatment with each of the five nongenotoxic carcinogens resulted in a unique composition of mRNAs of CYP2B1, 2B2, 2C6, 2C11, 3A1, 3A2, and 4A1, which were variably increased or decreased relative to the untreated control ...

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The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when /sup 125/I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, /sup 125/I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these ...

International Nuclear Information System (INIS)

Hepatic injury and regeneration of the liver are associated with activation of hepatic stellate cells (HSC). Fibroblast growth factors (FGFs) and their receptors are important regulators of repair in various tissues. HSC express FGFR3IIIc as well as FGFGR4 and different spliced FGFR1IIIc and FGFR2IIIc isoforms which differ in the presence or absence of the acid box and of the first Ig-like domain. Expression of FGF9, known to be capable to activate the HSC FGFR2/3-isoforms, was increased in HSC in liver slice cultures after exposition to carbon tetrachloride, as an acute liver injury model. FGF9 significantly stimulated 3-H thymidine incorporation of hepatocytes, but failed to induce DNA synthesis in HSC despite the fact that FGF9 induced a sustained activation of extracellular signal-related kinases (ERK) 1/2. FGF9 induced an increased phosphorylation of Tyr436 of the fibroblast growth factor receptor substrate (FRS) 2, ...

International Nuclear Information System (INIS)

The use of natural products in all over the world has been increased in Brazil as well as in other countries. Maytenus ilicifolia is commonly used in popular medicine. The labeling of red blood cells (RBC) with technetium-99m ("9"9"m Tc) have been for many studies in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is normally used. Here, we investigate if the extract of Maytenus ilicifolia is capable to alter the labeling of RBC and blood proteins with "9"9"m Tc. Blood samples were incubated with Maytenus ilicifolia. Stannous chloride solution and Tc-99m were. Blood was centrifuged and plasma (P) and blood cells (C) were isolated. Samples of P or C were precipitated with trichloroacetic acid, centrifuged and IF and IF were separated. The percentage of radioactivity (% ATI) in C, IF-P and IF-C was calculated. The %ATI in decreased in C from 93.6#+-#2.3 to 29.0#+-#2.7, on FI-P from ...

International Nuclear Information System (INIS)

In the use of doxorubicin and radiation for treatment of human malignant tumors in vivo, the relationship between treatment-induced apoptosis and Ki-67 labeling index was investigated. Four human tumor xenografts (ependymoblastoma, NNE; primitive neuroectodermal tumor, YKP; small cell lung carcinoma, GLS; glioblastoma, KYG) were transplanted under the skin of thigh of the nude mice (BALB/cA JcL-nu). The mice were given a single radiation dose of 1 Gy, or doxorubicin alone intraperitoneally at a dose of 8 mg/kg. After treatment, sections of tumor specimens were prepared from paraffin-embedded tissues. Hematoxylin and eosin staining, TUNEL staining, and immunohistochemical analysis of Ki-67 were performed. In NNE, apoptotic cells appeared most frequently after treatment compared with all other tumors, and the incidence of apoptosis in the radiation-treated group was much higher than in the doxorubicintreated group. As the incidence of apoptosis ...

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The rapid growth in the use of in vitro methods for nanoparticle toxicity assessment has proceeded with limited consideration of the unique kinetics of these materials in solution. Particles in general and nanoparticles specifically, diffuse, settle and agglomerate in cell culture media as a function of several systemic and particle factors: media density and viscosity, particle size, shape and density. Cellular dose then is also a function of these factors as they determine the rate of transport of nanoparticles to cells in culture. Here we develop and apply the principles of particokinetics and dosimetry in vitro and outline an approach for simulation of nanoparticle particokinetics in cell culture systems. We illustrate that where equal mass concentrations (?g/ml) imply equal doses for dissimilar materials, the corresponding particle number or surface area concentration doses differ by orders of magnitude. When rates of ...

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The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Two approaches have been adopted to get a stable cathode material. First approach is the use of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}, a commercially available lithium battery cathode material and the second is the use of tape cast electrodes prepared from cobalt coated nickel powders. The morphology and the structure of LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and tape cast Co coated nickel powder electrodes were ...

International Nuclear Information System (INIS)

The layered GdBa_0_._5Sr_0_._5Co_2O_5_+_#delta# (GBSC) perovskite oxides are synthesized by modified Pechini method and investigated as a novel cathode material for solid oxide fuel cells (SOFCs) based on a stable perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte. The fabricated single cells of NiO-BCZYZ/BCZYZ (#approx#20 #mu#m)/GBSC (#approx#20 #mu#m) were operated from 550 to 700 "oC with humidified hydrogen (#approx#5% H_2O) as fuel. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 "oC for 5 h, lower than that without zinc dopant about 150 "oC. An open circuit voltage of 1.009 V and a maximal power density of 0.35 W cm"-"2 were achieved at 700 "oC. The interfacial polarization resistance was as low as 1.46, 0.45, 0.25 and 0.15 #OMEGA# cm"2 at 550, 600, 650 and 700 "oC, respectively. The ratio of polarization resistance to total cell resistance decreased ...

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Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into channels filled with gas (stratified flow regime). The flow regimes of this system are visualized in plots of the pressure drop ...

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Energy storage can be a cost-effective component of hybrid remote power systems. Storage serves the special role of taking advantage of intermittent renewable power sources. Traditionally this role has been played by lead-acid batteries, which have high life-cycle costs and pose special disposal problems. Hydrogen or zinc-air storage technologies can reduce life-cycle costs and environmental impacts. Using projected data for advanced energy storage technologies, LLNL ran an optimization for a hypothetical Arctic community with a reasonable wind resource (average wind speed 8 m/s). These simulations showed the life-cycle annualized cost of the total energy system (electric plus space heating) might be reduced by nearly 40% simply by adding wind power to the diesel system. An additional 20 to 40% of the wind-diesel cost might be saved by adding hydrogen storage or zinc-air fuel cells to the system. Hydrogen produced by electrolysis of water using intermittent, ...

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This work presents the development of a streak camera 'jitter free' sweep unit synchronized on a femtosecond laser. This application of high voltage photoconductive switches ('High voltage Auston switch') yields subpicosecond resolution for accumulated images on streak camera on a few hundreds micro joule femtosecond laser. Two others applications of these photoconductive switches are studied: - ultrafast optical commutation by a Pockels cell directly driven by a photoconductive switch (rising edge < 100 ps and jitter < 2 ps), - laser pulse energy self-stabilization experimentally proving that driving a Pockels cell by a photoconductive switch can increase the stability of the laser pulse energy from 7 % to 0.7 % rms. Additionally, the application of the acoustic-optical programmable dispersive filter (Dazzler) to the self referenced spectral phase measurement is presented. ...

Science.gov (United States)

Primary adenocarcinomas of the urinary bladder are uncommon, and the molecular pathways are currently not well defined. In this study, we assessed the association between biologic markers and clinicopathologic characteristics in a cohort of 21 patients with primary urinary bladder adenocarcinoma. Immunohistochemical staining for cell cycle-specific markers, including p53, p21, p27, Ki-67, and cyclin E, were performed on sections of a tissue microarray construct. The tumors were high grade in 12 (57%) and pT2 or higher in 18 (86%); lymph nodes were involved in 6 cases (29%); and there was pathologic evidence of schistosomiasis in 14 (67%). The best prognostic combination of markers was combined alterations in p27 and Ki-67 and was associated with stage (P = .012), grade (P = .005), DNA ploidy (P = .005), and lymph node involvement (P = .04). Stage, lymph node involvement, combined alterations of p27 and Ki-67, and combined alterations of all 5 biomarkers were ...

British Library Electronic Table of Contents (United Kingdom)

The effects of gas diffusion layer's (GDL's) anisotropic bending stiffness on the degradation behavior of polymer electrolyte membrane fuel cells have been investigated under freezing conditions. We have prepared GDL sheet samples such that the higher stiffness direction of GDL roll is aligned with the major flow field direction of a metallic bipolar plate at angles of 0^o (parallel: '0^o GDL') and 90^o (perpendicular: '90^o GDL'). The I-V performances before and after 1000 temperature cycles between -10 and 1 ^oC of 90^o GDL stack are higher than those of 0^o GDL stack, and the voltages of 90^o GDL stack are decreased slower than those of 0^o GDL stack, indicating a higher durability of 90^o GDL stack. Furthermore, the values and increasing rates of high-frequency resistance of 90^o GDL s...

International Nuclear Information System (INIS)

To elucidate the mechanism of sunlight-induced skin damage, guinea pigs exposed to UV light (280-320 nm, UV B, 4J/cm"2) and a homogenate of the epidermis was examined by means of the thiobarbituric acid (TBA) test. Three hours after the exposure, TBA-malondialdehyde adducts had increased while glutathione reductase activity had decreased, indicating lipid peroxidation. To detect the initial species, spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to a suspension of illuminated epidermal cells (0.5 J/cm"2). An ESR signal obtained only with irradiation comprised a 1 : 2 : 2 : 1 quartet [a (N) =a (#beta#H) =1.49 mT] attributable to a spin adduct of hydroxyl radicals. These results suggest that sunlight exposure of skin may lead to hydroxyl radical generation and simultaneous lipid peroxidation. (author).

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A dense and supersaturated nitrogen layer with higher conductivity is obtained on the surface of austenitic stainless steel 304L by the low temperature plasma nitriding. The effect of plasma nitriding on the corrosion behavior and interfacial contact resistance (ICR) for the austenitic stainless steel 304L was investigated in 0.05M H{sub 2}SO{sub 4}+2ppm F{sup -} simulating proton exchange membrane fuel cell (PEMFC) environment using electrochemical and electric resistance measurements. The experiment results show that the stable passive film is formed after the potentiostatic polarization at the specified anodic or cathodic potentials under PEMFC operation condition, and the plasma nitriding improves slightly the corrosion resistance and decreases markedly the ICR of 304L. The ICR of the plasma nitrided 304L increases after the potentiostatic polarizations for 4h, and lower than 100m{omega}cm{sup 2} at the compaction force of 150Ncm{sup -2}. ...

International Nuclear Information System (INIS)

Although low-energy ion radiation has been proven to have a wide range of biological effects and led to fruitful achievements as a new mutagenic source for genetic modification, there still exist some disputes about its mutagenic mechanisms because of its short-penetrating property. In present research, Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability induced by irradiations of alpha particle (3.3MeV) and Low-energy-Argon ion (30 KeV). A pronounced effects of alpha particle irradiation to Arabidopsis thaliana seedlings and Argon ion irradiation to seeds on the somatic homologous recombination frequency (sHRF) were reported. The sHRFs increased 1.88-fold and 2.42-fold, respectively, which indicated that the short-penetrating radiation could effectively induce the plant genomic instability in either dry seeds or seedlings with active metabolism. The local alpha particle irradiation of root was performed. ...

Science.gov (United States)

To examine whether the neuroendocrine hormone norepinephrine may influence the production of the Shiga-like toxins (SLTs), several Escherichia coli O157:H7 clinical isolates were grown in the presence or absence of norepinephrine. An in vitro culture system consisting of low (<1500 colony-forming units/ml) initial concentrations of inocula into a serum-based medium was used to more closely approximate in vivo conditions. The growth of all isolates was increased several logs in the presence of norepinephrine, as compared with the growth in controls, during a 24-hour growth period. Controls included additional dextrose as well as the use of the norepinephrine metabolite normetanephrine, which contains one more methyl group than norepinephrine and hence would serve as a better energy source for growth if the effect were solely nutritionally mediated. During the 24 hours of growth, the production of cell-associated SLT-I on a protein-equivalent ...

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We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The accumulation studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The sorption efficiency toward Pu(VI) decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decreased total surface area and number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH ...

International Nuclear Information System (INIS)

The influence of serum, IGF-1 and TGF-#beta# on the differentiation of preadipocytes was examined in primary cultures of porcine adipose tissue cells. In serum-supplemented or serum-free, IGF-1 (1 and 10 nM) had no effect on total cell number. However, IGF-1 (10nM) increased adipocyte number only in serum-supplemented (1% pig serum) cultures, whereas TGF-#beta# (15 pm) reduced the adipocyte number in the presence and absence of IGF-1. Replication of preadipocytes was analyzed with a ["3H] thymidine assay. Preadipocyte proliferation (cpm in adipocyte fraction) was increased by IGF-1 (10nM) only in cultures containing pig serum. TGF-#beta# had no effect on preadipocyte proliferation specifically, but slightly increased total ["3H] thymidine incorporation in cultures with serum. Glycerol phosphate dehydrogenase (GPDH) specific activity was decreased by adding TGF-#beta# to serum-free ...

Science.gov (United States)

... Solar Cell Radiation Respinnse Near the Interface o~f fliffprerv- ... 5 4. CALCUTl-ATED SOLAR CELL RLSPONSE FOR VARIOUS BASE MATERIALS ...

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Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were ...