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Sample records for high cell numbers

  1. High-throughput quantitative analysis with cell growth kinetic curves for low copy number mutant cells.

    Science.gov (United States)

    Xing, James Z; Gabos, Stephan; Huang, Biao; Pan, Tianhong; Huang, Min; Chen, Jie

    2012-10-01

    The mutation rate in cells induced by environmental genotoxic hazards is very low and difficult to detect using traditional cell counting assays. The established genetic toxicity tests currently recognized by regulatory authorities, such as conventional Ames and hypoxanthine guanine phosphoribosyl-transferase (HPRT) assays, are not well suited for higher-throughput screening as they require large amounts of test compounds and are very time consuming. In this study, we developed a novel cell-based assay for quantitative analysis of low numbers of cell copies with HPRT mutation induced by an environmental mutagen. The HPRT gene mutant cells induced by the mutagen were selected by 6-thioguanine (6-TG) and the cell's kinetic growth curve monitored by a real-time cell electronic sensor (RT-CES) system. When a threshold is set at a certain cell index (CI) level, samples with different initial mutant cell copies take different amounts of time in order for their growth (or CI accumulation) to cross this threshold. The more cells that are initially seeded in the test well, the faster the cell accumulation and therefore the shorter the time required to cross this threshold. Therefore, the culture time period required to cross the threshold of each sample corresponds to the original number of cells in the sample. A mutant cell growth time threshold (MT) value of each sample can be calculated to predict the number of original mutant cells. For mutagenesis determination, the RT-CES assay displayed an equal sensitivity (p > 0.05) and coefficients of variation values with good correlation to conventional HPRT mutagenic assays. Most importantly, the RT-CES mutation assay has a higher throughput than conventional cellular assays.

  2. High fat feeding affects the number of GPR120 cells and enteroendocrine cells in the mouse stomach

    Directory of Open Access Journals (Sweden)

    Patricia eWidmayer

    2015-02-01

    Full Text Available Long-term intake of dietary fat is supposed to be associated with adaptive reactions of the organism and it is assumptive that this is particularly true for fat responsive epithelial cells in the mucosa of the gastrointestinal tract. Recent studies suggest that epithelial cells expressing the receptor for medium and long chain fatty acids, GPR120 (FFAR4, may operate as fat sensors. Changes in expression level and/or cell density are supposed to be accompanied with a consumption of high fat (HF diet. To assess whether feeding a HF diet might impact on the expression of fatty acid receptors or the number of lipid sensing cells as well as enteroendocrine cell populations, gastric tissue samples of non-obese and obese mice were compared using a real time PCR and immunohistochemical approach. In this study, we have identified GPR120 cells in the corpus region of the mouse stomach which appeared to be brush cells. Monitoring the effect of HF diet on the expression of GPR120 revealed that after 3 weeks and 6 months the level of mRNA for GPR120 in the tissue was significantly increased which coincided with and probably reflected a significant increase in the number of GPR120 positive cells in the corpus region; in contrast, within the antrum region, the number of GPR120 cells decreased. Furthermore, dietary fat intake also led to changes in the number of enteroendocrine cells producing either ghrelin or gastrin. After 3 weeks and even more pronounced after 6 months the number of ghrelin cells and gastrin cells was significantly increased. These results imply that a HF diet leads to significant changes in the cellular repertoire of the stomach mucosa. Whether these changes are a consequence of the direct exposure to high fat in the luminal content or a physiological response to the high level of fat in the body remains elusive.

  3. High fat feeding affects the number of GPR120 cells and enteroendocrine cells in the mouse stomach.

    Science.gov (United States)

    Widmayer, Patricia; Goldschmid, Hannah; Henkel, Helena; Küper, Markus; Königsrainer, Alfred; Breer, Heinz

    2015-01-01

    Long-term intake of dietary fat is supposed to be associated with adaptive reactions of the organism and it is assumptive that this is particularly true for fat responsive epithelial cells in the mucosa of the gastrointestinal tract. Recent studies suggest that epithelial cells expressing the receptor for medium and long chain fatty acids, GPR120 (FFAR4), may operate as fat sensors. Changes in expression level and/or cell density are supposed to be accompanied with a consumption of high fat (HF) diet. To assess whether feeding a HF diet might impact on the expression of fatty acid receptors or the number of lipid sensing cells as well as enteroendocrine cell populations, gastric tissue samples of non-obese and obese mice were compared using a real time PCR and immunohistochemical approach. In this study, we have identified GPR120 cells in the corpus region of the mouse stomach which appeared to be brush cells. Monitoring the effect of HF diet on the expression of GPR120 revealed that after 3 weeks and 6 months the level of mRNA for GPR120 in the tissue was significantly increased which coincided with and probably reflected a significant increase in the number of GPR120 positive cells in the corpus region; in contrast, within the antrum region, the number of GPR120 cells decreased. Furthermore, dietary fat intake also led to changes in the number of enteroendocrine cells producing either ghrelin or gastrin. After 3 weeks and even more pronounced after 6 months the number of ghrelin cells and gastrin cells was significantly increased. These results imply that a HF diet leads to significant changes in the cellular repertoire of the stomach mucosa. Whether these changes are a consequence of the direct exposure to HF in the luminal content or a physiological response to the high level of fat in the body remains elusive.

  4. Increased recombinant protein production owing to expanded opportunities for vector integration in high chromosome number Chinese hamster ovary cells.

    Science.gov (United States)

    Yamano, Noriko; Takahashi, Mai; Ali Haghparast, Seyed Mohammad; Onitsuka, Masayoshi; Kumamoto, Toshitaka; Frank, Jana; Omasa, Takeshi

    2016-08-01

    Chromosomal instability is a characteristic of Chinese hamster ovary (CHO) cells. Cultures of these cells gradually develop heterogeneity even if established from a single cell clone. We isolated cells containing different numbers of chromosomes from a CHO-DG44-based human granulocyte-macrophage colony stimulating factor (hGM-CSF)-producing cell line and found that high chromosome number cells showed higher hGM-CSF productivity. Therefore, we focused on the relationship between chromosome aneuploidy of CHO cells and high recombinant protein-producing cell lines. Distribution and stability of chromosomes were examined in CHO-DG44 cells, and two cell lines expressing different numbers of chromosomes were isolated from the original CHO-DG44 cell line to investigate the effect of aneuploid cells on recombinant protein production. Both cell lines were stably transfected with a vector that expresses immunoglobulin G3 (IgG3), and specific antibody production rates were compared. Cells containing more than 30 chromosomes had higher specific antibody production rates than those with normal chromosome number. Single cell analysis of enhanced green fluorescent protein (Egfp)-gene transfected cells revealed that increased GFP expression was relative to the number of gene integration sites rather than the difference in chromosome numbers or vector locations. Our results suggest that CHO cells with high numbers of chromosomes contain more sites for vector integration, a characteristic that could be advantageous in biopharmaceutical production.

  5. A simple high-content cell cycle assay reveals frequent discrepancies between cell number and ATP and MTS proliferation assays.

    Directory of Open Access Journals (Sweden)

    Grace Ka Yan Chan

    Full Text Available In order to efficiently characterize both antiproliferative potency and mechanism of action of small molecules targeting the cell cycle, we developed a high-throughput image-based assay to determine cell number and cell cycle phase distribution. Using this we profiled the effects of experimental and approved anti-cancer agents with a range mechanisms of action on a set of cell lines, comparing direct cell counting versus two metabolism-based cell viability/proliferation assay formats, ATP-dependent bioluminescence, MTS (3-(4,5-dimethylthiazol-2-yl-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl-2H-tetrazolium reduction, and a whole-well DNA-binding dye fluorescence assay. We show that, depending on compound mechanisms of action, the metabolism-based proxy assays are frequently prone to 1 significant underestimation of compound potency and efficacy, and 2 non-monotonic dose-response curves due to concentration-dependent phenotypic 'switching'. In particular, potency and efficacy of DNA synthesis-targeting agents such as gemcitabine and etoposide could be profoundly underestimated by ATP and MTS-reduction assays. In the same image-based assay we showed that drug-induced increases in ATP content were associated with increased cell size and proportionate increases in mitochondrial content and respiratory flux concomitant with cell cycle arrest. Therefore, differences in compound mechanism of action and cell line-specific responses can yield significantly misleading results when using ATP or tetrazolium-reduction assays as a proxy for cell number when screening compounds for antiproliferative activity or profiling panels of cell lines for drug sensitivity.

  6. High Glucose-Induced Oxidative Stress Increases the Copy Number of Mitochondrial DNA in Human Mesangial Cells

    Directory of Open Access Journals (Sweden)

    Ghada Al-Kafaji

    2013-01-01

    Full Text Available Oxidative damage to mitochondrial DNA (mtDNA has been linked to the pathogenicity of diabetic nephropathy. We tested the hypothesis that mtDNA copy number may be increased in human mesangial cells in response to high glucose-induced reactive oxygen species (ROS to compensate for damaged mtDNA. The effect of manganese superoxide dismutase mimetic (MnTBAP on glucose-induced mtDNA copy number was also examined. The copy number of mtDNA was determined by real-time PCR in human mesangial cells cultured in 5 mM glucose, 25 mM glucose, and mannitol (osmotic control, as well as in cells cultured in 25 mM glucose in the presence and absence of 200 μM MnTBAP. Intracellular ROS was assessed by confocal microscopy and flow cytometry in human mesangial cells. The copy number of mtDNA was significantly increased when human mesangial cells were incubated with 25 mM glucose compared to 5 mM glucose and mannitol. In addition, 25 mM glucose rapidly generated ROS in the cells, which was not detected in 5 mM glucose. Furthermore, mtDNA copy number was significantly decreased and maintained to normal following treatment of cells with 25 mM glucose and MnTBAP compared to 25 mM glucose alone. Inclusion of MnTBAP during 25 mM glucose incubation inhibited mitochondrial superoxide in human mesangial cells. Increased mtDNA copy number in human mesangial cells by high glucose could contribute to increased mitochondrial superoxide, and prevention of mtDNA copy number could have potential in retarding the development of diabetic nephropathy.

  7. Higher numbers of memory B-cells and Th2-cytokine skewing in high responders to hepatitis B vaccination.

    Science.gov (United States)

    Doedée, A M C M; Kannegieter, N; Öztürk, K; van Loveren, H; Janssen, R; Buisman, A M

    2016-04-27

    In the present study, differences in hepatitis B surface antigen (HBsAg)-specific memory B-cell responses between low and high responders to hepatitis B vaccine (HepB), based on levels of antibodies against HBsAg (anti-HBs), were determined. In addition, HBsAg specific T-cell responses between high (anti-HBs level >20,000 IU/L) and low (anti-HBs level Numbers of HBsAg-specific B-cells, plasma immunoglobulin G (Ig) levels, and T-cell cytokine concentrations were measured in low and high responders directly before and one month after the second booster vaccination. In advance, an Enzyme-linked Immunosorbent Spot (ELISpot) Assay was optimized for the determination of HBsAg-specific B-cell responses. The number of HBsAg-specific B-cells was significantly higher (pnumbers of HBsAg-specific B-cells were significantly correlated (RS=0.66, psignificant correlation (RS=0.6975, p=0.007) between the IL-13 levels and the plasma IgG levels post-booster was found. Subsequently, the IL-13 level in the high-responder group post-booster was significantly higher compared to the low-responder group. Since activation of the B-cell response after vaccination is induced by Th2 cells and IL-13 is produced by these cells, we conclude that the difference in HBsAg-specific Th2 cells is involved in determining the differences in anti-HBs level and memory B-cell numbers between low and high responders.

  8. Tumor infiltrating lymphocytes in melanoma comprise high numbers of T-cell clonotypes that are lost during in vitro culture

    DEFF Research Database (Denmark)

    thor Straten, P; Kirkin, A F; Siim, E;

    2000-01-01

    -associated peptide epitopes. Cultured TIL have been studied in order to unveil characteristics of TIL and the interactions of TIL and melanoma cells. Whether in vitro cultured TIL mirrors the in situ situation has, however, been questioned. In the present study we have taken advantage of T-cell receptor clonotype...... mapping methodology to conduct a full and detailed analysis of the T-cell clonotypes in melanoma lesions and in corresponding lines of TIL established in vitro. All melanoma lesions and the corresponding TIL cultures comprised high numbers of T-cell clonotypes, typically in the range of 40 to more than 60...... that in situ T-cell clonotypes in melanoma are not readily expanded in vitro and that the majority of T-cell clonotypes present in cultured TIL are not present in situ....

  9. Webcam-based flow cytometer using wide-field imaging for low cell number detection at high throughput.

    Science.gov (United States)

    Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

    2014-09-07

    Here we describe a novel low-cost flow cytometer based on a webcam capable of low cell number detection in a large volume which may overcome the limitations of current flow cytometry. Several key elements have been combined to yield both high throughput and high sensitivity. The first element is a commercially available webcam capable of 187 frames per second video capture at a resolution of 320 × 240 pixels. The second element in this design is a 1 W 450 nm laser module for area-excitation, which combined with the webcam allows for rapid interrogation of a flow field. The final element is a 2D flow-cell which overcomes the flow limitation of hydrodynamic focusing and allows for higher sample throughput in a wider flow field. This cell allows for the linear velocity of target cells to be lower than in a conventional "1D" hydrodynamic focusing flow-cells typically used in cytometry at similar volumetric flow rates. It also allows cells to be imaged at the full frame rate of the webcam. Using this webcam-based flow cytometer with wide-field imaging, it was confirmed that the detection of fluorescently tagged 5 μm polystyrene beads in "1D" hydrodynamic focusing flow-cells was not practical for low cell number detection due to streaking from the motion of the beads, which did not occur with the 2D flow-cell design. The sensitivity and throughput of this webcam-based flow cytometer was then investigated using THP-1 human monocytes stained with SYTO-9 florescent dye in the 2D flow-cell. The flow cytometer was found to be capable of detecting fluorescently tagged cells at concentrations as low as 1 cell per mL at flow rates of 500 μL min(-1) in buffer and in blood. The effectiveness of detection was concentration dependent: at 100 cells per mL 84% of the cells were detected compared to microscopy, 10 cells per mL 79% detected and 1 cell per mL 59% of the cells were detected. With the blood samples spiked to 100 cells per mL, the average concentration for all samples

  10. High-throughput single-cell analysis of low copy number β-galactosidase by a laboratory-built high-sensitivity flow cytometer.

    Science.gov (United States)

    Yang, Lingling; Huang, Tianxun; Zhu, Shaobin; Zhou, Yingxing; Jiang, Yunbin; Wang, Shuo; Chen, Yuqing; Wu, Lina; Yan, Xiaomei

    2013-10-15

    Single-cell analysis is vital in providing insights into the heterogeneity in molecular content and phenotypic characteristics of complex or clonal cell populations. As many essential proteins and most transcription factors are produced at a low copy number, analytical tools with superior sensitivity to enable the analysis of low abundance proteins in single cells are in high demand. β-galactosidase (β-gal) has been the standard cellular reporter for gene expression in both prokaryotic and eukaryotic cells. Here we report the development of a high-throughput method for the single-cell analysis of low copy number β-gal proteins using a laboratory-built high-sensitivity flow cytometer (HSFCM). Upon fluorescence staining with a fluorogenic substrate, quantitative measurements of the basal and near-basal expression of β-gal in single Escherichia coli BL21(DE3) cells were demonstrated. Statistical distribution can be determined quickly by analyzing thousands of individual cells in 1-2min, which reveals the heterogeneous expression pattern that is otherwise masked by the ensemble analysis. Combined with the quantitative fluorometric assay and the rapid bacterial enumeration by HSFCM, the β-gal expression distribution profile could be converted from arbitrary fluorescence units to protein copy numbers per cell. The sensitivity and speed of the HSFCM offers great capability in quantitative analysis of low abundance proteins in single cells, which would help gaining a deeper insight into the heterogeneity and fundamental biological processes in microbial populations.

  11. On the flow and thermal characteristics of high Reynolds numbers (2800-17000) dye cell: simulation and experiment

    CERN Document Server

    Mishra, G K; Prakash, O; Biswal, R; Dixit, S K; Nakhe, S V

    2014-01-01

    This paper presents computational and experimental studies on wavelength/frequency fluctuation characteristics of high pulse repetition rate (PRR: 18 kHz) dye laser pumped by frequency doubled Nd:YAG laser (532 nm). The temperature gradient in the dye solution is found to be responsible for wavelength fluctuations of the dye laser at low flow rates (2800number (ReT) and the range of eddy sizes present in the turbulent flow are found to be responsible for the fluctuations at high flow rates (8400cells for high PRR pumping.

  12. Prognostic impact of the number of viable circulating cells with high telomerase activity in gastric cancer patients: a prospective study.

    Science.gov (United States)

    Ito, Hiroaki; Inoue, Haruhiro; Kimura, Satoshi; Ohmori, Tohru; Ishikawa, Fumihiro; Gohda, Keigo; Sato, Jun

    2014-07-01

    The identification of circulating tumor cells (CTCs) in peripheral blood is a useful approach to estimate prognosis, monitor disease progression and measure treatment effects in several types of malignancies. We have previously used OBP-401, a telomerase-specific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein (GFP) gene. GFP-positive cells (GFP+ cells) were counted under a fluorescence microscope. Our results showed that the number of at least 7.735 µm in diameter GFP+ cells (L-GFP+ cells) in the peripheral blood was a significant marker of prognosis in gastric cancer patients. However, tumor cells undergoing epithelial-mesenchymal transition (EMT) have been reported to be smaller in size than cells without EMT features; thus, CTCs undergoing EMT may escape detection with this technique. Therefore, in this study, we analyzed the relationship between patient outcome and the number of GFP+ cells of any size. We obtained peripheral blood samples from 65 patients with gastric cancer. After infection of OBP-401, GFP+ cells were counted and measured. The relationship between the number of GFP+ cells and surgical outcome was analyzed. The median follow-up period of the surviving patients was 36 months. A significant difference in overall survival was found between patients with 0-5 and patients with ≥6 L-GFP+ cells. No clear relationship was established between the number of small-sized GFP+ cells and patient prognosis. The number of L-GFP+ cells was significantly related to overall survival in patients with gastric cancer. The detection of L-GFP+ cells using OBP-401 may be a useful prognostic marker in gastric cancer.

  13. Reverse-D-4F Increases the Number of Endothelial Progenitor Cells and Improves Endothelial Progenitor Cell Dysfunctions in High Fat Diet Mice.

    Science.gov (United States)

    Nana, Yang; Peng, Jiao; Jianlin, Zhang; Xiangjian, Zhang; Shutong, Yao; Enxin, Zhan; Bin, Li; Chuanlong, Zong; Hua, Tian; Yanhong, Si; Yunsai, Du; Shucun, Qin; Hui, Wang

    2015-01-01

    Although high density lipoprotein (HDL) improves the functions of endothelial progenitor cells (EPCs), the effect of HDL ApoAI mimetic peptide reverse-D-4F (Rev-D4F) on EPC mobilization and repair of EPC dysfunctions remains to be studied. In this study, we investigated the effects of Rev-D4F on peripheral blood cell subpopulations in C57 mice treated with a high fat diet and the mechanism of Rev-D4F in improving the function of EPCs impaired by tumor necrosis factor-α (TNF-α). The high fat diet significantly decreased the number of EPCs, EPC migratory functions, and the percentage of lymphocytes in the white blood cells. However, it significantly increased the number of white blood cells, the percentage of monocytes in the white blood cells, and the level of vascular endothelial growth factor (VEGF) and TNF-α in the plasma. Rev-D4F clearly inhibited the effect of the high fat diet on the quantification of peripheral blood cell subpopulations and cytokine levels, and increased stromal cell derived factor 1α (SDF-1α) in the plasma. We provided in vitro evidence that TNF-α impaired EPC proliferation, migration, and tube formation through inactive AKT and eNOS, which was restored by Rev-D4F treatment. In contrast, both the PI3-kinase (PI3K) inhibitor (LY294002) and AKT inhibitor (perifosine) obviously inhibited the restoration of Rev-4F on EPCs impaired by TNF-α. Our results suggested that Rev-D4F increases the quantity of endothelial progenitor cells through increasing the SDF-1α levels and decreasing the TNF-α level of peripheral blood in high fat diet-induced C57BL/6J mice, and restores TNF-α induced dysfunctions of EPCs partly through stimulating the PI3K/AKT signal pathway.

  14. Quasiperpendicular high Mach number Shocks

    CERN Document Server

    Sulaiman, A H; Dougherty, M K; Burgess, D; Fujimoto, M; Hospodarsky, G B

    2015-01-01

    Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\\tau}c, where {\\tau}c is the ion gyroperio...

  15. Neocortical glial cell numbers in human brains

    DEFF Research Database (Denmark)

    Pelvig, D.P.; Pakkenberg, H.; Stark, A.K.

    2008-01-01

    and neurons and counting were done in each of the four lobes. The study showed that the different subpopulations of glial cells behave differently as a function of age; the number of oligodendrocytes showed a significant 27% decrease over adult life and a strong correlation to the total number of neurons...... while the total astrocyte number is constant through life; finally males have a 28% higher number of neocortical glial cells and a 19% higher neocortical neuron number than females. The overall total number of neocortical neurons and glial cells was 49.3 billion in females and 65.2 billion in males......, a difference of 24% with a high biological variance. These numbers can serve as reference values in quantitative studies of the human neocortex. (C) 2007 Elsevier Inc. All rights reserved Udgivelsesdato: 2008/11...

  16. High dosage of monosodium glutamate causes deficits of the motor coordination and the number of cerebellar Purkinje cells of rats.

    Science.gov (United States)

    Prastiwi, D; Djunaidi, A; Partadiredja, G

    2015-11-01

    Monosodium glutamate (MSG) has been widely used throughout the world as a flavoring agent of food. However, MSG at certain dosages is also thought to cause damage to many organs, including cerebellum. This study aimed at investigating the effects of different doses of MSG on the motor coordination and the number of Purkinje cells of the cerebellum of Wistar rats. A total of 24 male rats aged 4 to 5 weeks were divided into four groups, namely, control (C), T2.5, T3, and T3.5 groups, which received intraperitoneal injection of 0.9% sodium chloride solution, 2.5 mg/g body weight (bw) of MSG, 3.0 mg/g bw of MSG, and 3.5 mg/g bw of MSG, respectively, for 10 consecutive days. The motor coordination of the rats was examined prior and subsequent to the treatment. The number of cerebellar Purkinje cells was estimated using physical fractionator method. It has been found that the administration of MSG at a dosage of 3.5 mg/g bw, but not at lower dosages, caused a significant decrease of motor coordination and the estimated total number of Purkinje cells of rats. There was also a significant correlation between motor coordination and the total number of Purkinje cells.

  17. Generation of a High Number of Healthy Erythroid Cells from Gene-Edited Pyruvate Kinase Deficiency Patient-Specific Induced Pluripotent Stem Cells

    Science.gov (United States)

    Garate, Zita; Quintana-Bustamante, Oscar; Crane, Ana M.; Olivier, Emmanuel; Poirot, Laurent; Galetto, Roman; Kosinski, Penelope; Hill, Collin; Kung, Charles; Agirre, Xabi; Orman, Israel; Cerrato, Laura; Alberquilla, Omaira; Rodriguez-Fornes, Fatima; Fusaki, Noemi; Garcia-Sanchez, Felix; Maia, Tabita M.; Ribeiro, Maria L.; Sevilla, Julian; Prosper, Felipe; Jin, Shengfang; Mountford, Joanne; Guenechea, Guillermo; Gouble, Agnes; Bueren, Juan A.; Davis, Brian R.; Segovia, Jose C.

    2015-01-01

    Summary Pyruvate kinase deficiency (PKD) is a rare erythroid metabolic disease caused by mutations in the PKLR gene. Erythrocytes from PKD patients show an energetic imbalance causing chronic non-spherocytic hemolytic anemia, as pyruvate kinase defects impair ATP production in erythrocytes. We generated PKD induced pluripotent stem cells (PKDiPSCs) from peripheral blood mononuclear cells (PB-MNCs) of PKD patients by non-integrative Sendai viral vectors. PKDiPSCs were gene edited to integrate a partial codon-optimized R-type pyruvate kinase cDNA in the second intron of the PKLR gene by TALEN-mediated homologous recombination (HR). Notably, we found allele specificity of HR led by the presence of a single-nucleotide polymorphism. High numbers of erythroid cells derived from gene-edited PKDiPSCs showed correction of the energetic imbalance, providing an approach to correct metabolic erythroid diseases and demonstrating the practicality of this approach to generate the large cell numbers required for comprehensive biochemical and metabolic erythroid analyses. PMID:26549847

  18. Generation of a High Number of Healthy Erythroid Cells from Gene-Edited Pyruvate Kinase Deficiency Patient-Specific Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Zita Garate

    2015-12-01

    Full Text Available Pyruvate kinase deficiency (PKD is a rare erythroid metabolic disease caused by mutations in the PKLR gene. Erythrocytes from PKD patients show an energetic imbalance causing chronic non-spherocytic hemolytic anemia, as pyruvate kinase defects impair ATP production in erythrocytes. We generated PKD induced pluripotent stem cells (PKDiPSCs from peripheral blood mononuclear cells (PB-MNCs of PKD patients by non-integrative Sendai viral vectors. PKDiPSCs were gene edited to integrate a partial codon-optimized R-type pyruvate kinase cDNA in the second intron of the PKLR gene by TALEN-mediated homologous recombination (HR. Notably, we found allele specificity of HR led by the presence of a single-nucleotide polymorphism. High numbers of erythroid cells derived from gene-edited PKDiPSCs showed correction of the energetic imbalance, providing an approach to correct metabolic erythroid diseases and demonstrating the practicality of this approach to generate the large cell numbers required for comprehensive biochemical and metabolic erythroid analyses.

  19. Generation of a High Number of Healthy Erythroid Cells from Gene-Edited Pyruvate Kinase Deficiency Patient-Specific Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Garate, Zita; Quintana-Bustamante, Oscar; Crane, Ana M; Olivier, Emmanuel; Poirot, Laurent; Galetto, Roman; Kosinski, Penelope; Hill, Collin; Kung, Charles; Agirre, Xabi; Orman, Israel; Cerrato, Laura; Alberquilla, Omaira; Rodriguez-Fornes, Fatima; Fusaki, Noemi; Garcia-Sanchez, Felix; Maia, Tabita M; Ribeiro, Maria L; Sevilla, Julian; Prosper, Felipe; Jin, Shengfang; Mountford, Joanne; Guenechea, Guillermo; Gouble, Agnes; Bueren, Juan A; Davis, Brian R; Segovia, Jose C

    2015-12-08

    Pyruvate kinase deficiency (PKD) is a rare erythroid metabolic disease caused by mutations in the PKLR gene. Erythrocytes from PKD patients show an energetic imbalance causing chronic non-spherocytic hemolytic anemia, as pyruvate kinase defects impair ATP production in erythrocytes. We generated PKD induced pluripotent stem cells (PKDiPSCs) from peripheral blood mononuclear cells (PB-MNCs) of PKD patients by non-integrative Sendai viral vectors. PKDiPSCs were gene edited to integrate a partial codon-optimized R-type pyruvate kinase cDNA in the second intron of the PKLR gene by TALEN-mediated homologous recombination (HR). Notably, we found allele specificity of HR led by the presence of a single-nucleotide polymorphism. High numbers of erythroid cells derived from gene-edited PKDiPSCs showed correction of the energetic imbalance, providing an approach to correct metabolic erythroid diseases and demonstrating the practicality of this approach to generate the large cell numbers required for comprehensive biochemical and metabolic erythroid analyses.

  20. A high number of IgG4-positive cells in gastric cancer tissue is associated with tumor progression and poor prognosis.

    Science.gov (United States)

    Miyatani, Kozo; Saito, Hiroaki; Murakami, Yuki; Watanabe, Joji; Kuroda, Hirohiko; Matsunaga, Tomoyuki; Fukumoto, Yoji; Osaki, Tomohiro; Nakayama, Yuji; Umekita, Yoshihisa; Ikeguchi, Masahide

    2016-05-01

    IgG4-related disease is a newly defined disease characterized by elevated serum IgG4 levels and infiltration of affected organs by IgG4-positive plasma cells. Recently, increased IgG4 levels were reported to be closely related with malignancy. To assess the relationship between IgG4 and the progression of gastric cancer, we immunohistochemically stained in this study gastric cancer tissue samples for IgG4-positive cells using an anti-IgG4 antibody. In addition, pre- and postoperative serum concentrations of IgG4 were measured, using an enzyme-linked immunosorbent assay. In gastric cancer samples, the number of CD138-positive plasma cells was significantly lower and the number of IgG4-positive cells significantly higher than in non-cancerous gastric mucosa. The number of IgG4-positive cells was significantly correlated with gross tumor appearance, tumor depth, lymph node metastasis, venous invasion, and lymphatic invasion. Prognosis was significantly poorer in patients with a high number of IgG4-positive cells than in those with a low number. Multivariate analysis indicated that both the number of IgG4-positive cells and the depth of tumor invasion were independently prognostic of survival. In conclusion, in gastric cancer, the number of IgG4-positive cells is increased and this is closely associated with gastric cancer progression.

  1. Quasiperpendicular High Mach Number Shocks

    Science.gov (United States)

    Sulaiman, A. H.; Masters, A.; Dougherty, M. K.; Burgess, D.; Fujimoto, M.; Hospodarsky, G. B.

    2015-09-01

    Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (MA ) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ˜0.3 τc , where τc is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA , a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

  2. High Population Density of Juvenile Chum Salmon Decreased the Number and Sizes of Growth Hormone Cells in the Pituitary

    OpenAIRE

    Salam, Md. Abdus; Ota, Yuki; Ando, Hironori; Fukuwaka, Masa-aki; Kaeriyama, Masahide; Urano, Akihisa

    1999-01-01

    Juveniles of chum salmon (Oncorhynchus keta) held at high population density were apparently smaller than those held at medium and low population densities. The effects of high population density on pituitary growth hormone (GH) cells in juvenile chum salmon were examined using immunocytochemical and in situ hybridization techniques. The ratio of GH-immunoreactive (ir) area to the whole pituitary was almost constant in all of the high, medium and low population density groups, although the nu...

  3. High modal number and triple trisomies are highly correlated favorable factors in childhood B-cell precursor high hyperdiploid acute lymphoblastic leukemia treated according to the NOPHO ALL 1992/2000 protocols

    DEFF Research Database (Denmark)

    Paulsson, Kajsa Maria; Forestier, Erik; Andersen, Mette K

    2013-01-01

    23), or t(12;21). The median age of patients with "classic" high hyperdiploidy was lower than that of patients with translocation-positive high hyperdiploidy (P53/55 (P=0.020/0.024). In multivariate analyses, modal number and triple trisomies were significantly associated with superior event......-free survival in separate analyses with age and white blood cell counts. When including both modal numbers and triple trisomies, only low white blood cell counts were significantly associated with superior event-free survival (P=0.009). We conclude that high modal chromosome numbers and triple trisomies...

  4. High Chromosome Number in hematological cancer cell lines is a Negative Predictor of Response to the inhibition of Aurora B and C by GSK1070916

    Directory of Open Access Journals (Sweden)

    Hardwicke Mary

    2011-07-01

    Full Text Available Abstract Background Aurora kinases play critical roles in mitosis and are being evaluated as therapeutic targets in cancer. GSK1070916 is a potent, selective, ATP competitive inhibitor of Aurora kinase B and C. Translation of predictive biomarkers to the clinic can benefit patients by identifying the tumors that are more likely to respond to therapies, especially novel inhibitors such as GSK1070916. Methods 59 Hematological cancer-derived cell lines were used as models for response where in vitro sensitivity to GSK1070916 was based on both time and degree of cell death. The response data was analyzed along with karyotype, transcriptomics and somatic mutation profiles to determine predictors of response. Results 20 cell lines were sensitive and 39 were resistant to treatment with GSK1070916. High chromosome number was more prevalent in resistant cell lines (p-value = 0.0098, Fisher Exact Test. Greater resistance was also found in cell lines harboring polyploid subpopulations (p-value = 0.00014, Unpaired t-test. A review of NOTCH1 mutations in T-ALL cell lines showed an association between NOTCH1 mutation status and chromosome number (p-value = 0.0066, Fisher Exact Test. Conclusions High chromosome number associated with resistance to the inhibition of Aurora B and C suggests cells with a mechanism to bypass the high ploidy checkpoint are resistant to GSK1070916. High chromosome number, a hallmark trait of many late stage hematological malignancies, varies in prevalence among hematological malignancy subtypes. The high frequency and relative ease of measurement make high chromosome number a viable negative predictive marker for GSK1070916.

  5. Intraepithelial macrophage infiltration is related to a high number of regulatory T cells and promotes a progressive course of HPV-induced vulvar neoplasia.

    Science.gov (United States)

    van Esch, Edith M G; van Poelgeest, Mariette I E; Trimbos, J Baptist M Z; Fleuren, Gert Jan; Jordanova, Ekaterina S; van der Burg, Sjoerd H

    2015-02-15

    Human papilloma virus (HPV)-induced usual-type vulvar intraepithelial neoplasia (uVIN) is infiltrated by myeloid cells but the type and role of these cells is unclear. We used triple immunofluorescent confocal microscopy to locate, identify and quantify myeloid cells based on their staining pattern for CD14, CD33 and CD163 in a cohort of 43 primary and 20 recurrent uVIN lesions, 21 carcinomas and 26 normal vulvar tissues. The progressive course of uVIN is characterized by an increase in both intraepithelial and stromal mature M1 and M2 macrophages. While the M2 macrophages outnumber M1 macrophages in healthy controls and uVIN, they are matched in number by M1 macrophages in cancer. Importantly, uVIN patients with a dense intraepithelial infiltration with mature CD14+ macrophages (irrespective of M1 or M2 type) displayed approximately a six times higher risk to develop a recurrence and a high number of these cells constituted an independent prognostic factor for recurrence. In addition, a dense intraepithelial CD14+ cell infiltration was associated with high numbers of intraepithelial CD4+ Tregs and low numbers of stromal CD8+TIM3+ T cells. Patients with low numbers of intraepithelial CD14+ cells and high numbers of stromal CD8+TIM3+ cells showed the best recurrence-free survival. These data clearly show the importance of the local immune response in HPV-induced vulvar neoplasia and may be of help in predicting the prognosis of patients or their response to immunotherapy.

  6. Increased number of cancer cells in bronchial washing fluid detected by combining conventional cytology and high-resolution flow cytometry.

    Science.gov (United States)

    Cicconetti, F; Teodori, L; Persiani, M; Di Tondo, U; Alò, P; Marci, A; Brun, S; Göhde, W

    1997-01-01

    The present study was performed to improve early lung cancer diagnosis in bronchial washing fluid, thereby increasing the diagnostic sensitivity of bronchoscopy by means of high-resolution flow cytometry (FC). We combined dual-parameter DNA/protein FC and conventional cytology in bronchial washing fluid samples from 112 patients with neoplastic and non-neoplastic lung diseases and found 43% of histologically confirmed tumor cases to be cytologically positive; 63% of the tumor samples were aneuploid, 52% of the aneuploid cases were cytologically positive and 48% were negative. In the negative cases, FC was an independent diagnostic factor. In 32% of the cases, FC also failed to detect abnormalities. However, the combination of both techniques increased the sensitivity in detecting neoplastic cells to 73%. Furthermore, simultaneous DNA/protein analysis allowed the recognition of aneuploid cell lines not detectable by single DNA measurement. Identification of aneuploid subpopulations by dual-parameter analysis in cytologically negative one-parameter FC "diploid" samples assumes an important diagnostic value. Dual-parameter DNA/protein FC is a valuable technique that increases the diagnostic yield of bronchoscopy with no risk for the patient and a low additional cost.

  7. Increased cycling cell numbers and stem cell associated proteins as potential biomarkers for high grade human papillomavirus+ve pre-neoplastic cervical disease.

    Directory of Open Access Journals (Sweden)

    Maurice Canham

    Full Text Available High risk (oncogenic human papillomavirus (HPV infection causes cervical cancer. Infections are common but most clear naturally. Persistent infection can progress to cancer. Pre-neoplastic disease (cervical intraepithelial neoplasia/CIN is classified by histology (CIN1-3 according to severity. Cervical abnormalities are screened for by cytology and/or detection of high risk HPV but both methods are imperfect for prediction of which women need treatment. There is a need to understand the host virus interactions that lead to different disease outcomes and to develop biomarker tests for accurate triage of infected women. As cancer is increasingly presumed to develop from proliferative, tumour initiating, cancer stem cells (CSCs, and as other oncogenic viruses induce stem cell associated gene expression, we evaluated whether presence of mRNA (detected by qRT-PCR or proteins (detected by flow cytometry and antibody based proteomic microarray from stem cell associated genes and/or increased cell proliferation (detected by flow cytometry could be detected in well-characterised, routinely collected cervical samples from high risk HPV+ve women. Both cytology and histology results were available for most samples with moderate to high grade abnormality. We found that stem cell associated proteins including human chorionic gonadotropin, the oncogene TP63 and the transcription factor SOX2 were upregulated in samples from women with CIN3 and that the stem cell related, cell surface, protein podocalyxin was detectable on cells in samples from a subset of women with CIN3. SOX2, TP63 and human gonadotrophin mRNAs were upregulated in high grade disease. Immunohistochemistry showed that SOX2 and TP63 proteins clearly delineated tumour cells in invasive squamous cervical cancer. Samples from women with CIN3 showed increased proliferating cells. We believe that these markers may be of use to develop triage tests for women with high grade cervical abnormality to

  8. High numbers of IL-2-producing CD8+ T cells during viral infection: correlation with stable memory development

    DEFF Research Database (Denmark)

    Kristensen, Nanna Ny; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2002-01-01

    that IL-2-producing cells appear slightly delayed compared with the majority of IFN-gamma producing cells, and the relative frequency of the IL-2-producing subset increases with transition into the memory phase. In contrast to acute immunizing infection, few IL-2-producing cells are generated during......Using infections with lymphocytic choriomeningitis virus (LCMV) and vesicular stomatitis virus in mice as model systems, we have investigated the ability of antigen-primed CD8+ T cells generated in the context of viral infections to produce IL-2. Our results indicate that acute immunizing infection...

  9. Tumor infiltrating lymphocytes in melanoma comprise high numbers of T-cell clonotypes that are lost during in vitro culture

    DEFF Research Database (Denmark)

    thor Straten, P; Kirkin, A F; Siim, E

    2000-01-01

    Melanoma is generally accepted as being an antigenic tumor capable of eliciting T-cell responses that, however, in most cases are inadequate to control tumor growth. Tumor-infiltrating lymphocytes (TIL) in melanoma lesions comprise clonotypic T cells, indicating the in situ recognition of melanoma......-associated peptide epitopes. Cultured TIL have been studied in order to unveil characteristics of TIL and the interactions of TIL and melanoma cells. Whether in vitro cultured TIL mirrors the in situ situation has, however, been questioned. In the present study we have taken advantage of T-cell receptor clonotype...

  10. High-Throughput Platform for Patient-Derived, Small Cell Number, Three-Dimensional Ovarian Cancer Spheroids

    Science.gov (United States)

    2014-09-01

    different ratios (1:1, 1:3 and 1:6) with 50 cells/drop in 10% bovine serum containing medium. Phase micrographs shown on day 4. Tight sphere...medium is composed of 50/50 v/v DMEM/F12, 0.5X ITS, 1.5X Antibiotics /Antimycotics, 5ng/ml bFGF, 5ng/ml EGF, and 1X NEAA. Scale bar = 100µm. 21...hanging drop plate. Serum free medium is composed of 50/50 v/v DMEM/F12, 0.5X ITS, 1.5X Antibiotics /Antimycotics, 5ng/ml bFGF, 5ng/ml EGF, and 1X NEAA

  11. High Atom Number in Microsized Atom Traps

    Science.gov (United States)

    2015-12-14

    Final Performance Report on ONR Grant N00014-12-1-0608 High atom number in microsized atom traps for the period 15 May 2012 through 14 September...TYPE Final Technical Report 3. DATES COVERED (From - To) 05/15/2012-09/14/2012 4. TITLE AND SUBTITLE High atom number in microsized atom traps...forces for implementing a small-footprint, large-number atom -chip instrument. Bichromatic forces rely on absorption and stimulated emission to produce

  12. On quark number susceptibilities at high temperatures

    CERN Document Server

    Bazavov, A; Hegde, P; Karsch, F; Miao, C; Mukherjee, Swagato; Petreczky, P; Schmidt, C; Velytsky, A

    2013-01-01

    We calculated second and fourth order quark number susceptibilities for 2+1 flavor QCD in the high temperature region using two improved staggered fermion formulations. The calculations are performed at several lattice spacing and we show that in the continuum limit the two formulations give consistent results. We compare our continuum extrapolated results on quark number susceptibilities with recent weak coupling calculations, and find that these cannot simultaneously explain the lattice results for second and fourth order quark number susceptibilities.

  13. Depletion of Regulatory T Cells Induces High Numbers of Dendritic Cells and Unmasks a Subset of Anti-Tumour CD8+CD11c+ PD-1lo Effector T Cells.

    Directory of Open Access Journals (Sweden)

    Nicolas Goudin

    Full Text Available Natural regulatory T (Treg cells interfere with multiple functions, which are crucial for the development of strong anti-tumour responses. In a model of 4T1 mammary carcinoma, depletion of CD25+Tregs results in tumour regression in Balb/c mice, but the mechanisms underlying this process are not fully understood. Here, we show that partial Treg depletion leads to the generation of a particular effector CD8 T cell subset expressing CD11c and low level of PD-1 in tumour draining lymph nodes. These cells have the capacity to migrate into the tumour, to kill DCs, and to locally regulate the anti-tumour response. These events are concordant with a substantial increase in CD11b+ resident dendritic cells (DCs subsets in draining lymph nodes followed by CD8+ DCs. These results indicate that Treg depletion leads to tumour regression by unmasking an increase of DC subsets as a part of a program that optimizes the microenvironment by orchestrating the activation, amplification, and migration of high numbers of fully differentiated CD8+CD11c+PD1lo effector T cells to the tumour sites. They also indicate that a critical pattern of DC subsets correlates with the evolution of the anti-tumour response and provide a template for Treg depletion and DC-based therapy.

  14. BioNumbers--the database of key numbers in molecular and cell biology.

    Science.gov (United States)

    Milo, Ron; Jorgensen, Paul; Moran, Uri; Weber, Griffin; Springer, Michael

    2010-01-01

    BioNumbers (http://www.bionumbers.hms.harvard.edu) is a database of key numbers in molecular and cell biology--the quantitative properties of biological systems of interest to computational, systems and molecular cell biologists. Contents of the database range from cell sizes to metabolite concentrations, from reaction rates to generation times, from genome sizes to the number of mitochondria in a cell. While always of importance to biologists, having numbers in hand is becoming increasingly critical for experimenting, modeling, and analyzing biological systems. BioNumbers was motivated by an appreciation of how long it can take to find even the simplest number in the vast biological literature. All numbers are taken directly from a literature source and that reference is provided with the number. BioNumbers is designed to be highly searchable and queries can be performed by keywords or browsed by menus. BioNumbers is a collaborative community platform where registered users can add content and make comments on existing data. All new entries and commentary are curated to maintain high quality. Here we describe the database characteristics and implementation, demonstrate its use, and discuss future directions for its development.

  15. High Rayleigh number convection numerical experiments

    Science.gov (United States)

    Verzicco, Roberto

    2002-03-01

    Numerical experiments on the flow developing in a cylindrical cell of aspect ratio Γ = 1/2 heated from below and cooled from above, are conducted for Rayleigh numbers (Ra) ranging from 2 x 10^6 up to 2 x 10^11. The aim of the present study is to numerically replicate the experiments by Roche et al. (2001) and Niemela et al. (2000) performed using gaseous helium close to the critical point as working fluid (Pr = 0.7). The numerical simulation permitted us to generate a large data base which was validated by the experimental results and, on the other hand, provided physical insights which are missed by the experimental approaches usually limited to pointwise temperature and global heat exchange measurements. Attention is focussed on the presence of large-scale structures whose characterization is important owing to the introduction of constant `winds' sweeping the plates and generating viscous and thermal boundary layers. The analysis of instantaneous snapshots clearly indicates that the topology of the recirculating large scale structures is quite different with respect to what is commonly observed in Γ = 1 cells where a unique large scale recirculation structure completely fills the fluid volume (e.g. Verzicco & Camussi, 1999). It is shown that a transition occurs at about Ra = 10^9; at lower Ra the flow is characterized by the presence of two counter-rotating toroidal rings attached to the horizontal plates. At larger Ra, in contrast, the most intense structure consists of two counter-rotating rolls of unitary aspect ratio. The two types of flow, which co-exists in the range 10^9 < Ra < 10^10, determine different properties of both the thermal and the viscous boundary layers. Indeed, even if the limited range of Ra analyzed in the present simulation does not allow the presence of a transition to be clearly observed in the Nu vs Ra diagram, the proposed scenario is confirmed by the direct analysis of the boundary layer thicknesses and of the kinetic energy and

  16. Chaotic behaviour of high Mach number flows

    Science.gov (United States)

    Varvoglis, H.; Ghosh, S.

    1985-01-01

    The stability of the super-Alfvenic flow of a two-fluid plasma model with respect to the Mach number and the angle between the flow direction and the magnetic field is investigated. It is found that, in general, a large scale chaotic region develops around the initial equilibrium of the laminar flow when the Mach number exceeds a certain threshold value. After reaching a maximum the size of this region begins shrinking and goes to zero as the Mach number tends to infinity. As a result high Mach number flows in time independent astrophysical plasmas may lead to the formation of 'quasi-shocks' in the presence of little or no dissipation.

  17. Use of ubiquitous, highly heterozygous copy number variants and digital droplet polymerase chain reaction to monitor chimerism after allogeneic haematopoietic stem cell transplantation.

    Science.gov (United States)

    Whitlam, John B; Ling, Ling; Swain, Michael; Harrington, Tom; Mirochnik, Oksana; Brooks, Ian; Cronin, Sara; Challis, Jackie; Petrovic, Vida; Bruno, Damien L; Mechinaud, Francoise; Conyers, Rachel; Slater, Howard

    2017-01-29

    Chimerism analysis has an important role in the management of allogeneic hematopoietic stem cell transplantation. It informs response to disease relapse, graft rejection, and graft-versus-host disease. We have developed a method for chimerism analysis using ubiquitous copy number variation (CNV), which has the benefit of a "negative background" against which multiple independent informative markers are quantified using digital droplet polymerase chain reaction. A panel of up to 38 CNV markers with homozygous deletion frequencies of approximately 0.4-0.6 were used. Sensitivity, precision, reproducibility, and informativity were assessed. CNV chimerism results were compared against established fluorescence in situ hybridization, single nucleotide polymorphism, and short tandem repeat-based methods with excellent correlation. Using 30 ng of input DNA per well, the limit of detection was 0.05% chimerism and the limit of quantification was 0.5% chimerism. High informativity was seen with a median of four informative markers detectable per individual in 39 recipients and 43 donor genomes studied. The strength of this approach was exemplified in a multiple donor case involving four genomes (three related). The precision, sensitivity, and informativity of this approach recommend it for use in clinical practice.

  18. Achieving high performance non-fullerene organic solar cells through tuning the numbers of electron deficient building blocks of molecular acceptors

    Science.gov (United States)

    Yang, Lei; Chen, Yusheng; Chen, Shangshang; Dong, Tao; Deng, Wei; Lv, Lei; Yang, Saina; Yan, He; Huang, Hui

    2016-08-01

    Two analogous dimer and tetramer compounds, SF-PDI2 and SF-PDI4, were designed, theoretically calculated, synthesized, and developed as electron acceptors for organic solar cells. The effects of the number of the electron deficient building blocks on the optical absorption, energy levels, charge transport, morphology, crystallinity, and photovoltaic performance of the molecules were investigated. In combination with two different donors, PTB7-Th and PffBT4T-2OD, the results showed that increasing the numbers of PDI building blocks is beneficial to photovoltaic performance and leads to efficiency over 5%.

  19. Binary droplet collision at high Weber number.

    Science.gov (United States)

    Pan, Kuo-Long; Chou, Ping-Chung; Tseng, Yu-Jen

    2009-09-01

    By using the techniques developed for generating high-speed droplets, we have systematically investigated binary droplet collision when the Weber number (We) was increased from the range usually tested in previous studies on the order of 10 to a much larger value of about 5100 for water (a droplet at 23 m/s with a diameter of 0.7 mm). Various liquids were also used to explore the effects of viscosity and surface tension. Specifically, beyond the well-known regimes at moderate We's, which exhibited coalescence, separation, and separation followed by satellite droplets, we found different behaviors showing a fingering lamella, separation after fingering, breakup of outer fingers, and prompt splattering into multiple secondary droplets as We was increased. The critical Weber numbers that mark the boundaries between these impact regimes are identified. The specific impact behaviors, such as fingering and prompt splattering or splashing, share essential similarity with those also observed in droplet-surface impacts, whereas substantial variations in the transition boundaries may result from the disparity of the boundary conditions at impacts. To compare the outcomes of both types of collisions, a simple model based on energy conservation was carried out to predict the maximum diameter of an expanding liquid disk for a binary droplet collision. The results oppose the dominance of viscous drag, as proposed by previous studies, as the main deceleration force to effect a Rayleigh-Taylor instability and ensuing periphery fingers, which may further lead to the formations of satellite droplets.

  20. Pair separation in high Reynolds number turbulence

    CERN Document Server

    Bourgoin, M O; Xu, H; Joergensen, J B; Bodenschatz, E; Bourgoin, Mickael; Ouellette, Nicholas T.; Xu, Haitao; Joergensen, Jacob B.; Bodenschatz, Eberhard

    2005-01-01

    The separation of two nearby particles in a turbulent flow is fundamental in our everyday lives. Turbulent mixing is important everywhere from mundane applications like stirring milk into a cup of tea to technological processes such as the mixing of chemicals in reactors, combustion engines, or jet turbines. Environmental problems such as the spread of pollutants or bioagents in the atmosphere and oceans are fundamentally turbulent mixing processes. Even biological organisms use it to survive in marine ecosystems. Despite intense scientific inquiry, however, no convincing agreement has been found with the Richardson and Batchelor two-particle dispersion predictions over a wide range of timescales. Here we report measurements in a laboratory water flow at very high turbulence intensities (Taylor microscale Reynolds numbers of R_lambda = 690 and 815) that show excellent agreement with a refinement of Batchelor's prediction. We find that even for large initial spatial separations Batchelor scaling is fulfilled. ...

  1. Mixing in High Schmidt Number Turbulent Jets.

    Science.gov (United States)

    Miller, Paul Lewis

    This thesis is an experimental investigation of the passive scalar (species concentration) field in the far-field of round, axisymmetric, high Schmidt number (liquid phase), turbulent jets issuing into a quiescent reservoir, by means of a quantitative laser-induced fluorescence technique. Single -point concentration measurements are made on the jet centerline, at axial locations from 100 to 305 nozzle diameters downstream, and Reynolds numbers of 3,000 to 102,000, yielding data with a resolved temporal dynamic range up to 2.5 times 10^5, and capturing as many as 504 large-scale structure passages. Long-time statistics of the jet concentration are found to converge slowly. Between 100 and 300 large-scale structure passages are required to reduce the uncertainty in the mean to 1%, or so. The behavior of the jet varies with Reynolds number. The centerline concentration pdf's become taller and narrower with increasing Re, and the normalized concentration variances correspondingly decrease with Re. The concentration power spectra also evolve with Re. The behavior of the spectral slopes is examined. No constant -1 (Batchelor) spectral slope range is present. Rather, in the viscous region, the power spectra exhibit log-normal behavior, over a range of scales exceeding a factor of 40, in some cases. The frequency of the beginning of this log-normal range scales like Re^{3/4} (Kolmogorov scaling). Mixing in the far-field is found to be susceptible to initial conditions. Disturbances in the jet plenum fluid and near the nozzle exit strongly influence the scalar variance, with larger disturbances causing larger variances, i.e., less homogeneous mixing. The plenum/nozzle geometry also influences the variance. These effects of initial conditions persist for hundreds of diameters from the nozzle exit, over hundreds of large scales. Mixing in these jets differs from gas-phase, order unity Sc, jet mixing. At low to moderate Re, the higher Sc jet is less well mixed. The difference

  2. High speed optical quantum random number generation.

    Science.gov (United States)

    Fürst, Martin; Weier, Henning; Nauerth, Sebastian; Marangon, Davide G; Kurtsiefer, Christian; Weinfurter, Harald

    2010-06-07

    We present a fully integrated, ready-for-use quantum random number generator (QRNG) whose stochastic model is based on the randomness of detecting single photons in attenuated light. We show that often annoying deadtime effects associated with photomultiplier tubes (PMT) can be utilized to avoid postprocessing for bias or correlations. The random numbers directly delivered to a PC, generated at a rate of up to 50 Mbit/s, clearly pass all tests relevant for (physical) random number generators.

  3. Random Number Generation for High Performance Computing

    Science.gov (United States)

    2015-01-01

    TOTAL: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Discipline Robin Schulze 0.43 0.43 1 Names of Post Doctorates Names of Faculty Supported...Agent, or Firm- Meyertons, Hood , Kivlin, Kowert & Goetze!, P.C.; Eric B. Meyertons (57) ABSTRACT A method of assessing parallel random number...Meyertons, Hood , Kivlin, Kowert & Goetzel, P.C. P.O. Box 398 Austin, TX 78767-0398 Ph: (512) 853-8800 PATENT 5660-14400

  4. Number theory meets high energy physics

    Science.gov (United States)

    Todorov, Ivan

    2017-03-01

    Feynman amplitudes in perturbative quantum field theory are being expressed in terms of an algebra of functions, extending the familiar logarithms, and associated numbers— periods. The study of these functions (including hyperlogarithms) and numbers (like the multiple zeta values), that dates back to Leibniz and Euler, has attracted anew the interest of algebraic geometers and number theorists during the last decades. The two originally independent developments are recently coming together in an unlikely collaboration between particle physics and what were regarded as the most abstruse branches of mathematics.

  5. High numbers of differentiated effector CD4 T cells are found in patients with cancer and correlate with clinical response after neoadjuvant therapy of breast cancer.

    Science.gov (United States)

    Péguillet, Isabelle; Milder, Maud; Louis, Delphine; Vincent-Salomon, Anne; Dorval, Thierry; Piperno-Neumann, Sophie; Scholl, Suzy M; Lantz, Olivier

    2014-04-15

    CD4(+) T cells influence tumor immunity in complex ways that are not fully understood. In this study, we characterized a population of human differentiated effector CD4(+) T cells that is defined by low levels of the interleukin (IL)-2 and IL-7 receptors (CD25(-)CD127(-)). We found that this cell population expands in patients with various types of cancer, including breast cancer, to represent 2% to 20% of total CD4(+) blood T lymphocytes as compared with only 0.2% to 2% in healthy individuals. Notably, these CD25(-)CD127(-)CD4 T cells expressed effector markers such as CD244 and CD11b with low levels of CD27, contrasting with the memory phenotype dominating this population in healthy individuals. These cells did not cycle in patients, nor did they secrete IL-10 or IL-17, but instead displayed cytotoxic features. Moreover, they encompassed oligoclonal expansions paralleling an expansion of effector CD8(+) T cells that included tumor antigen-specific T cells. During neoadjuvant chemotherapy in patients with breast cancer, we found that the increase in CD25(-)CD127(-) CD4(+) T cells correlated with tumor regression. This observation suggested that CD4(+) T cells included tumor antigen-specific cells, which may be generated by or participate in tumor regressions during chemotherapy. In summary, our results lend support to the hypothesis that CD4(+) T cells are involved in human antitumor responses.

  6. Suppression of lymphocyte proliferation by marijuana components is related to cell number and cell source

    Energy Technology Data Exchange (ETDEWEB)

    Klein, T.; Pross, S.; Newton, C.; Friedman, H.

    1986-03-05

    Conflicting reports have appeared concerning the effect of marijuana components on immune responsiveness. The authors have observed that the effect of cannabinoids on lymphocyte proliferation varied with both the concentration of the drug and the mitogen used. They now report that at a constant concentration of drug, the cannabinoid effect varied from no effect to suppression depending upon the number of cells in culture and the organ source of the cells. Dispersed cell suspensions of mouse lymph node, spleen, and thymus were prepared and cultured at varying cell numbers with either delta-9-tetrahydrocannabinol or 11-hydroxy-delta-9-tetrahydrocannabinol and various mitogens. Lymphocyte proliferation was analyzed by /sup 3/H-thymidine incorporation. T-lymphocyte mitogen responses in cultures containing high cell numbers were unaffected by the cannabinoids but as cell numbers were reduced a suppression of the response was observed. Furthermore, thymus cells were considerably more susceptible to cannabinoid suppression than cells from either lymph node or spleen. These results suggest that certain lymphocyte subpopulations are more sensitive to cannabinoid suppression and that in addition to drug concentration other variables such as cell number and cell source must be considered when analyzing cannabinoid effects.

  7. Dual-use conversion of a high-Mach-number jet engine test cell for industrial gas turbine low-emission combustor development

    Energy Technology Data Exchange (ETDEWEB)

    Pillsbury, P.W.; Ryan, W.R. [Westinghouse Electric Corp., Orlando, FL (United States); Moore, J.R. [Sverdrup Technology, Inc., Arnold AFB, TN (United States). AEDC Group

    1997-01-01

    With the recent trend of reducing US military expenditures, it has become desirable to develop dual use of certain Department of Defense facilities. These efforts have a commercial purpose, while still retaining a military benefit. The goals of these efforts are to make US business more competitive in world markets, to develop the technology to solve pressing national problems, and to maintain intact the necessary talent pool and equipment for possible military needs. In a recent initiative described in this paper, test cell equipment at the Arnold Engineering Development Center, Arnold AFB, Tennessee, was modified and expanded to allow development by the Westinghouse Electric Corporation of low-emission combustors for heavy-duty gas turbines for commercial power generation.

  8. High Prandtl number effect on Rayleigh-Bénard convection heat transfer at high Rayleigh number

    Science.gov (United States)

    Ma, Li; Li, Jing; Ji, Shui; Chang, Huajian

    2017-02-01

    This paper represents results of the Rayleigh-Bénard convection heat transfer in silicon oil confined by two horizontal plates, heated from below, and cooled from above. The Prandtl numbers considered as 100-10,000 corresponding to three types of silicon oil. The experiments covered a range of Rayleigh numbers from 2.14·109 to 2.27·1013. The data points that the Nusselt number dependents on the Rayleigh number, which is asymptotic to a 0.248 power. Furthermore, the experiment results can fit the data in low Rayleigh number well.

  9. Bone marrow B cell precursor number after allogeneic stem cell transplantation and GVHD development.

    Science.gov (United States)

    Fedoriw, Yuri; Samulski, T Danielle; Deal, Allison M; Dunphy, Cherie H; Sharf, Andrew; Shea, Thomas C; Serody, Jonathan S; Sarantopoulos, Stefanie

    2012-06-01

    Patients without chronic graft-versus-host disease (cGVHD) have robust B cell reconstitution and are able to maintain B cell homeostasis after allogeneic hematopoietic stem cell transplantation (HSCT). To determine whether B lymphopoiesis differs before cGVHD develops, we examined bone marrow (BM) biopsies for terminal deoxynucleotidyl transferase (TdT) and PAX5 immunostaining early post-HSCT at day 30 when all patients have been shown to have high B cell activating factor (BAFF) levels. We found significantly greater numbers of BM B cell precursors in patients who did not develop cGVHD compared with those who developed cGVHD (median = 44 vs 2 cells/high powered field [hpf]; respectively; P < .001). Importantly, a significant increase in precursor B cells was maintained when patients receiving high-dose steroid therapy were excluded (median = 49 vs 20 cells/hpf; P = .017). Thus, we demonstrate the association of BM B cell production capacity in human GVHD development. Increased BM precursor B cell number may serve to predict good clinical outcome after HSCT. Copyright © 2012 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  10. Increased mast cell numbers in a calcaneal tendon overuse model.

    Science.gov (United States)

    Pingel, J; Wienecke, J; Kongsgaard, M; Behzad, H; Abraham, T; Langberg, H; Scott, A

    2013-12-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats were divided in two groups: running group (n = 12); sedentary control group (n = 12). The running-group was exposed to the HIUR exercise protocol for 7 weeks. The calcaneal tendons of both hind limbs were dissected. The right tendon was used for histologic analysis using Bonar score, immunohistochemistry, and second harmonic generation microscopy (SHGM). The left tendon was used for quantitative polymerase chain reaction (qPCR) analysis. An increased tendon cell density in the runners were observed compared to the controls (P = 0.05). Further, the intensity of immunostaining of protein kinase B, P = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further that these changes are associated with an increased mast cell density.

  11. An open label phase II study evaluating first-line EGFR tyrosine kinase inhibitor erlotinib in non-small cell lung cancer patients with tumors showing high EGFR gene copy number

    Science.gov (United States)

    Kowalczyk, Anna; Suszko-Kazarnowicz, Malgorzata; Duchnowska, Renata; Szczesna, Aleksandra; Ratajska, Magdalena; Sowa, Aleksander; Limon, Janusz; Biernat, Wojciech; Burzykowski, Tomasz; Jassem, Jacek; Dziadziuszko, Rafal

    2017-01-01

    Background First-line treatment with epidermal growth factor receptor (EGFR) inhibitors in NSCLC is effective in patients with activating EGFR mutations. The activity of erlotinib in patients harboring high EGFR gene copy number has been considered debatable. Patients and Methods A multicenter, open-label, single-arm phase II clinical trial was performed to test the efficacy of erlotinib in the first-line treatment of NSCLC patients harboring high EGFR gene copy number defined as =4 copies in =40% of cells. Findings Between December 2007 and April 2011, tumor samples from 149 subjects were screened for EGFR gene copy number by fluorescence in-situ hybridization (FISH), Out of 49 patients with positive EGFR FISH test, 45 were treated with erlotinib. Median PFS in the intent-to-treat population was 3.3 months (95%CI: 1.83.9 months), and median overall survival was 7.9 months (95% CI: 5.112.6 months). Toxicity profile of erlotinib was consistent with its known safety profile. The trial was stopped prematurely at 63% of originally planned sample size due to accumulating evidence that EGFR gene copy number should not be used to select NSCLC patients to first-line therapy with EGFR TKI. Data on erlotinib efficacy according to EGFR, KRAS and BRAF mutations are additionally presented. Interpretation This trial argues against using high gene copy number for selection of NSCLC patients to first-line therapy with EGFR TKIs. The study adds to the discussion on efficacy of other targeted agents in patients with target gene amplified tumors. PMID:27924059

  12. Limitations and possibilities of low cell number ChIP-seq

    Directory of Open Access Journals (Sweden)

    Gilfillan Gregor D

    2012-11-01

    Full Text Available Abstract Background Chromatin immunoprecipitation coupled with high-throughput DNA sequencing (ChIP-seq offers high resolution, genome-wide analysis of DNA-protein interactions. However, current standard methods require abundant starting material in the range of 1–20 million cells per immunoprecipitation, and remain a bottleneck to the acquisition of biologically relevant epigenetic data. Using a ChIP-seq protocol optimised for low cell numbers (down to 100,000 cells / IP, we examined the performance of the ChIP-seq technique on a series of decreasing cell numbers. Results We present an enhanced native ChIP-seq method tailored to low cell numbers that represents a 200-fold reduction in input requirements over existing protocols. The protocol was tested over a range of starting cell numbers covering three orders of magnitude, enabling determination of the lower limit of the technique. At low input cell numbers, increased levels of unmapped and duplicate reads reduce the number of unique reads generated, and can drive up sequencing costs and affect sensitivity if ChIP is attempted from too few cells. Conclusions The optimised method presented here considerably reduces the input requirements for performing native ChIP-seq. It extends the applicability of the technique to isolated primary cells and rare cell populations (e.g. biobank samples, stem cells, and in many cases will alleviate the need for cell culture and any associated alteration of epigenetic marks. However, this study highlights a challenge inherent to ChIP-seq from low cell numbers: as cell input numbers fall, levels of unmapped sequence reads and PCR-generated duplicate reads rise. We discuss a number of solutions to overcome the effects of reducing cell number that may aid further improvements to ChIP performance.

  13. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  14. Genomic Control of Retinal Cell Number: Challenges, Protocol, and Results.

    Science.gov (United States)

    Keeley, Patrick W; Whitney, Irene E; Reese, Benjamin E

    2017-01-01

    This chapter considers some of the challenges in obtaining accurate and consistent estimates of neuronal population size in the mouse retina, in order to identify the genetic control of cell number through QTL mapping and candidate gene analysis. We first discuss a variety of best practices for analyzing large numbers of recombinant inbred strains of mice over the course of a year in order to amass a satisfactory dataset for QTL mapping. We then consider the relative merits of using average cell density versus estimated total cell number as the target trait to be assessed, and why estimates of heritability may differ for these two traits when studying the retina in whole-mount preparations. Using our dataset on cell number for 12 different retinal cell types across the AXB/BXA recombinant inbred strain set as an example, we briefly review the QTL identified and their relationship to one another. Finally, we discuss our strategies for parsing QTL in order to identify prospective candidate genes, and how those candidates may in turn be dissected to identify causal regulatory or coding variants. By identifying the genetic determinants of nerve cell number in this fashion, we can then explore their roles in modulating developmental processes that underlie the formation of the retinal architecture.

  15. Towards a high-speed quantum random number generator

    Science.gov (United States)

    Stucki, Damien; Burri, Samuel; Charbon, Edoardo; Chunnilall, Christopher; Meneghetti, Alessio; Regazzoni, Francesco

    2013-10-01

    Randomness is of fundamental importance in various fields, such as cryptography, numerical simulations, or the gaming industry. Quantum physics, which is fundamentally probabilistic, is the best option for a physical random number generator. In this article, we will present the work carried out in various projects in the context of the development of a commercial and certified high speed random number generator.

  16. U.S. Opioid Prescriptions Fall, But Numbers Still High

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_167050.html U.S. Opioid Prescriptions Fall, But Numbers Still High: CDC And ... THURSDAY, July 6, 2017 (HealthDay News) -- Prescriptions for opioid painkillers have dropped since 2010 in the United ...

  17. Promoting Number Theory in High Schools or Birthday Problem and Number Theory

    Science.gov (United States)

    Srinivasan, V. K.

    2010-01-01

    The author introduces the birthday problem in this article. This can amuse willing members of any birthday party. This problem can also be used as the motivational first day lecture in number theory for the gifted students in high schools or in community colleges or in undergraduate classes in colleges.

  18. Promoting number theory in high schools or birthday problem and number theory

    Science.gov (United States)

    Srinivasan, V. K.

    2010-04-01

    The author introduces the birthday problem in this article. This can amuse willing members of any birthday party. This problem can also be used as the motivational first day lecture in number theory for the gifted students in high schools or in community colleges or in undergraduate classes in colleges.

  19. Mast cell numbers in normal and glaucomatous canine eyes.

    Science.gov (United States)

    Louden, C; Render, J A; Carlton, W W

    1990-05-01

    Numbers of mast cells in the cornea, sclera, choroid, ciliary body, iris, and retina of sections of globes from 35 clinically normal dogs and 34 dogs with secondary glaucoma was determined. Fixed globes were trimmed along a vertical midsagittal plane and embedded in paraffin. Tissue sections, approximately 6 microns thick, were stained with toluidine blue for identification of mast cells. In normal globes, most of the mast cells were observed in the anterior portion of the uvea, and fewer mast cells were seen in the choroid and sclera. Mast cells were not observed in the retina and were seldom observed in the cornea of dogs with or without glaucoma. In sections of glaucomatous globes, mast cells were distributed evenly in the uvea and sclera, and fewer mast cells were present than in normal globes, regardless of the cause of glaucoma.

  20. Sertoli cells maintain Leydig cell number and peritubular myoid cell activity in the adult mouse testis.

    Directory of Open Access Journals (Sweden)

    Diane Rebourcet

    Full Text Available The Sertoli cells are critical regulators of testis differentiation and development. In the adult, however, their known function is restricted largely to maintenance of spermatogenesis. To determine whether the Sertoli cells regulate other aspects of adult testis biology we have used a novel transgenic mouse model in which Amh-Cre induces expression of the receptor for Diphtheria toxin (iDTR specifically within Sertoli cells. This causes controlled, cell-specific and acute ablation of the Sertoli cell population in the adult animal following Diphtheria toxin injection. Results show that Sertoli cell ablation leads to rapid loss of all germ cell populations. In addition, adult Leydig cell numbers decline by 75% with the remaining cells concentrated around the rete and in the sub-capsular region. In the absence of Sertoli cells, peritubular myoid cell activity is reduced but the cells retain an ability to exclude immune cells from the seminiferous tubules. These data demonstrate that, in addition to support of spermatogenesis, Sertoli cells are required in the adult testis both for retention of the normal adult Leydig cell population and for support of normal peritubular myoid cell function. This has implications for our understanding of male reproductive disorders and wider androgen-related conditions affecting male health.

  1. Genome wide copy number analysis of single cells

    Science.gov (United States)

    Baslan, Timour; Kendall, Jude; Rodgers, Linda; Cox, Hilary; Riggs, Mike; Stepansky, Asya; Troge, Jennifer; Ravi, Kandasamy; Esposito, Diane; Lakshmi, B.; Wigler, Michael; Navin, Nicholas; Hicks, James

    2016-01-01

    Summary Copy number variation (CNV) is increasingly recognized as an important contributor to phenotypic variation in health and disease. Most methods for determining CNV rely on admixtures of cells, where information regarding genetic heterogeneity is lost. Here, we present a protocol that allows for the genome wide copy number analysis of single nuclei isolated from mixed populations of cells. Single nucleus sequencing (SNS), combines flow sorting of single nuclei based on DNA content, whole genome amplification (WGA), followed by next generation sequencing to quantize genomic intervals in a genome wide manner. Multiplexing of single cells is discussed. Additionally, we outline informatic approaches that correct for biases inherent in the WGA procedure and allow for accurate determination of copy number profiles. All together, the protocol takes ~3 days from flow cytometry to sequence-ready DNA libraries. PMID:22555242

  2. The evolution of per-cell organelle number

    Directory of Open Access Journals (Sweden)

    Logan W. Cole

    2016-08-01

    Full Text Available Organelles with their own distinct genomes, such as plastids and mitochondria, are found in most eukaryotic cells. As these organelles and their host cells have evolved, the partitioning of metabolic processes and the encoding of interacting gene products have created an obligate codependence. This relationship has played a role in shaping the number of organelles in cells through evolution. Factors such as stochastic evolutionary forces acting on genes involved in organelle biogenesis, organelle-nuclear gene interactions, and physical limitations may, to varying degrees, dictate the selective constraint that per-cell organelle number is under. In particular, coordination between nuclear and organellar gene expression may be important in maintaining gene product stoichiometry, which may have a significant role in constraining the evolution of this trait.

  3. Simulating High Reynolds Number Flow by Lattice Boltzmann Method

    Institute of Scientific and Technical Information of China (English)

    KANG Xiu-Ying; LIU Da-He; ZHOU Jing; JIN Yong-Juan

    2005-01-01

    @@ A two-dimensional channel flow with different Reynolds numbers is tested by using the lattice Boltzmann method under different pressure and velocity boundary conditions. The results show that the simulation error increases,and the pressure and the flow rate become unstable under a high Reynolds number. To improve the simulation precision under a high Reynolds number, the number of fluid nodes should be enlarged. For a higher Reynoldsnumber flow, the velocity boundary with an approximately parabolic velocity profile is found to be more adaptive.Blood flow in an artery with cosine shape symmetrical narrowing is then simulated under a velocity boundary condition. Its velocity, pressure and wall shear stress distributions are consistent with previous studies.

  4. August Passenger and Cargo Numbers Set New Highs

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Passenger and cargo numbers set new highs in August, the second consecutive month that both areas of operation at Dragonair posted record figures. The airline flew 444,498 passengers in August to record its third consecutive monthly record. The number was 7.7%higher than in July, with travel in both months driven by holiday traffic. August 15 saw a new daily mark set, with 17,220passengers carried on the day.

  5. Numerical simulation of LBGK model for high Reynolds number flow

    Institute of Scientific and Technical Information of China (English)

    Zhou Xiao-Yang; Shi Bao-Chang; Wang Neng-Chao

    2004-01-01

    A principle of selecting relaxation parameter was proposed to observe the limit computational capability of the incompressible LBGK models developed by Guo ZL (Guo model) and He SY (He model) for high Reynolds number flow.To the two-dimensional driven cavity flow problem, the highest Reynolds numbers covered by Guo and He models are in the range 58000-52900 and 28000-29000, respectively, at 0.3 Mach number and 1/256 lattice space. The simulation results also show that the Guo model has stronger robustness due to its higher accuracy.

  6. Materials for high-temperature fuel cells

    CERN Document Server

    Jiang, San Ping; Lu, Max

    2013-01-01

    There are a large number of books available on fuel cells; however, the majority are on specific types of fuel cells such as solid oxide fuel cells, proton exchange membrane fuel cells, or on specific technical aspects of fuel cells, e.g., the system or stack engineering. Thus, there is a need for a book focused on materials requirements in fuel cells. Key Materials in High-Temperature Fuel Cells is a concise source of the most important and key materials and catalysts in high-temperature fuel cells with emphasis on the most important solid oxide fuel cells. A related book will cover key mater

  7. Do bacterial cell numbers follow a theoretical Poisson distribution? Comparison of experimentally obtained numbers of single cells with random number generation via computer simulation.

    Science.gov (United States)

    Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso; Koseki, Shigenobu

    2016-12-01

    We investigated a bacterial sample preparation procedure for single-cell studies. In the present study, we examined whether single bacterial cells obtained via 10-fold dilution followed a theoretical Poisson distribution. Four serotypes of Salmonella enterica, three serotypes of enterohaemorrhagic Escherichia coli and one serotype of Listeria monocytogenes were used as sample bacteria. An inoculum of each serotype was prepared via a 10-fold dilution series to obtain bacterial cell counts with mean values of one or two. To determine whether the experimentally obtained bacterial cell counts follow a theoretical Poisson distribution, a likelihood ratio test between the experimentally obtained cell counts and Poisson distribution which parameter estimated by maximum likelihood estimation (MLE) was conducted. The bacterial cell counts of each serotype sufficiently followed a Poisson distribution. Furthermore, to examine the validity of the parameters of Poisson distribution from experimentally obtained bacterial cell counts, we compared these with the parameters of a Poisson distribution that were estimated using random number generation via computer simulation. The Poisson distribution parameters experimentally obtained from bacterial cell counts were within the range of the parameters estimated using a computer simulation. These results demonstrate that the bacterial cell counts of each serotype obtained via 10-fold dilution followed a Poisson distribution. The fact that the frequency of bacterial cell counts follows a Poisson distribution at low number would be applied to some single-cell studies with a few bacterial cells. In particular, the procedure presented in this study enables us to develop an inactivation model at the single-cell level that can estimate the variability of survival bacterial numbers during the bacterial death process.

  8. High-Cycle-Life Lithium Cell

    Science.gov (United States)

    Yen, S. P. S.; Carter, B.; Shen, D.; Somoano, R.

    1985-01-01

    Lithium-anode electrochemical cell offers increased number of charge/ discharge cycles. Cell uses components selected for compatibility with electrolyte solvent: These materials are wettable and chemically stable. Low vapor pressure and high electrochemical stability of solvent improve cell packaging, handling, and safety. Cell operates at modest temperatures - less than 100 degrees C - and is well suited to automotive, communications, and other applications.

  9. Glucocorticoids decrease Treg cell numbers in lungs of allergic mice.

    Science.gov (United States)

    Olsen, P C; Kitoko, J Z; Ferreira, T P; de-Azevedo, C T; Arantes, A C; Martins, Μ A

    2015-01-15

    Glucocorticoids have been the hallmark anti-inflammatory drug used to treat asthma. It has been shown that glucocorticoids ameliorate asthma by increasing numbers and activity of Tregs, in contrast recent data show that glucocorticoid might have an opposite effect on Treg cells from normal mice. Since Tregs are target cells that act on the resolution of asthma, the aim of this study was to elucidate the effect of glucocorticoid treatment on lung Tregs in mouse models of asthma. Allergen challenged mice were treated with either oral dexamethasone or nebulized budesonide. Broncoalveolar lavage and airway hyperresponsiveness were evaluated after allergenic challenge. Lung, thymic and lymph node cells were phenotyped on Treg through flow cytometry. Lung cytokine secretion was detected by ELISA. Although dexamethasone inhibited airway inflammation and hyperresponsiveness, improving resolution, we have found that both dexamethasone and budesonide induce a reduction of Treg numbers on lungs and lymphoid organs of allergen challenged mice. The reduction of lung Treg levels was independent of mice strain or type of allergen challenge. Our study also indicates that both glucocorticoids do not increase Treg activity through production of IL-10. Glucocorticoid systemic or localized treatment induced thymic atrophy. Taken together, our results demonstrate that glucocorticoids decrease Treg numbers and activity in different asthma mouse models, probably by reducing thymic production of T cells. Therefore, it is possible that glucocorticoids do not have beneficial effects on lung populations of Treg cells from asthmatic patients.

  10. The structure of the velocity and passive scalar fields in high Reynolds number and high Peclet number grid turbulence

    Science.gov (United States)

    Mydlarski, Laurent Bernard

    1998-10-01

    Turbulence theories are generally posed for isotropic turbulence in the limit of infinite turbulent Reynolds and Peclet numbers. Until now, it has been impossible to satisfy these constraints simultaneously in either experiments or simulations. By use of an active grid, devised by Makita, nearly isotropic turbulence with large turbulent Reynolds and Peclet numbers is generated. Turbulent Reynolds numbers based on the Taylor microscale, Rλ, in excess of 700 are achieved. The evolution of the velocity and passive scalar fields from low to high Reynolds and Peclet numbers is studied by generating turbulent fields in wind tunnels. The measurements are made by hot-wire anemometry and cold- wire thermometry. The passive scalar (generated by a mean scalar gradient) is temperature in air. The velocity field shows significant variation with Reynolds number. The slope of the inertial subrange is a function of Reynolds number and is noticeably below the Kolmogorov value of 5/3 for Rλconvective scaling range for the scalar (with slope close to 5/3) is observed for all Peclet numbers. The effects of the internal intermittency of the scalar are present at all Peclet numbers. The scalar field exhibits some (Peclet-number- independent) violations of local isotropy in the direction of the imposed gradient for odd-ordered statistics. The understanding of the 'ramp-cliff' structures (to which this anisotropy is attributed) is extended by describing it in terms of three-point statistics-the most fundamental order at which the odd- ordered statistics can be examined.

  11. Impact of High Mathematics Education on the Number Sense

    Science.gov (United States)

    Castronovo, Julie; Göbel, Silke M.

    2012-01-01

    In adult number processing two mechanisms are commonly used: approximate estimation of quantity and exact calculation. While the former relies on the approximate number sense (ANS) which we share with animals and preverbal infants, the latter has been proposed to rely on an exact number system (ENS) which develops later in life following the acquisition of symbolic number knowledge. The current study investigated the influence of high level math education on the ANS and the ENS. Our results showed that the precision of non-symbolic quantity representation was not significantly altered by high level math education. However, performance in a symbolic number comparison task as well as the ability to map accurately between symbolic and non-symbolic quantities was significantly better the higher mathematics achievement. Our findings suggest that high level math education in adults shows little influence on their ANS, but it seems to be associated with a better anchored ENS and better mapping abilities between ENS and ANS. PMID:22558077

  12. Effects of a diet high in fish oil (MaxEPA) on the formation of micronucleated erythrocytes in blood and on the number of atypical acinar cell foci induced in rat pancreas by Azaserine

    NARCIS (Netherlands)

    Appel, M.J.; Woutersen, R.A.

    2004-01-01

    The present study was performed to investigate the influence of fish oil on the genotoxic effects of azaserine, using the formation of micronucleated erythrocytes as a measure for the degree of initiating potency and the number and size of putative preneoplastic pancreatic atypical acinar cell foci

  13. High Red Blood Cell Count

    Science.gov (United States)

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  14. Wire-number effects on high-power annular z-pinches and some characteristics at high wire number

    Energy Technology Data Exchange (ETDEWEB)

    SANFORD,THOMAS W. L.

    2000-05-23

    Characteristics of annular wire-array z-pinches as a function of wire number and at high wire number are reviewed. The data, taken primarily using aluminum wires on Saturn are comprehensive. The experiments have provided important insights into the features of wire-array dynamics critical for high x-ray power generation, and have initiated a renaissance in z-pinches when high numbers of wires are used. In this regime, for example, radiation environments characteristic of those encountered during the early pulses required for indirect-drive ICF ignition on the NIF have been produced in hohlraums driven by x-rays from a z-pinch, and are commented on here.

  15. Decrease in immune activation in HIV-infected patients treated with highly active antiretroviral therapy correlates with the function of hematopoietic progenitor cells and the number of naive CD4+ cells

    DEFF Research Database (Denmark)

    Nielsen, S D; Sørensen, T U; Ersbøll, A K;

    2000-01-01

    determined. During the study period, the naive CD4+ count and the cloning efficiency increased significantly. Immune activation was found in HIV-infected patients and decreased during HAART. The level of immune activation correlated negatively with both the naive CD4+ count and the function of progenitor...... cells. A negative correlation was found between apoptosis and the naive CD4+ count. Alterations in cytokine production during HAART or correlation between cytokine production and the naive CD4+ count or the cloning efficiency of progenitor cells were not detected. In conclusion, immune activation in HIV...

  16. Evolution vs the number of gene copies per primitive cell.

    Science.gov (United States)

    Koch, A L

    1984-01-01

    Computer simulations are presented of the rate at which an advantageous mutant would displace the prototype in a replicating system without an accurate segregation mechanism. If the number of gene copies in the system is indefinitely large, Darwinian evolution is essentially stopped because there is no coupling of phenotype with genotype, i.e., there is no growth advantage to the advantageous gene relative to the prototype and therefore no "survival of the fittest." The inhibition of evolution due to a number of gene copies less than 100 would have been not insurmountable. Although the presence of multiple copies would have allowed replacement by an advantageous mutant, it provided a way for the primitive cell to conserve less immediately useful genes that could evolve into different or more effective genes. This possibility was lost as accurate segregation mechanisms evolved and cells with few copies of each gene, such as modern procaryotes, arose.

  17. High cetane number paraffinic diesel fuels and emission reduction

    Energy Technology Data Exchange (ETDEWEB)

    Larmi, M.; Tilli, A.; Kaario, O.; Gong, Y.; Antila, E.; Sarjovaara, T.; Hillamo, H.; Hakkinen, K.; Lehto, K. [Helsinki Univ. of Technology, Helsinki (Finland); Brink, A. [Aalborg Univ., Aalborg (Finland); Aakko, P. [Saksa VTT, Espoo (Finland)

    2009-07-01

    This presentation discussed high cetane number (CN) paraffinic diesel fuels and emission reduction. The presentation outlined the synthetic and renewable fuels to be studied, including high CN paraffinic diesel fuels like hydrotreated vegetable oil (HVO) and FT-diesel fuel; high CN paraffinic diesel fuels with high concentration of oxygenates; biogas/NPG and dual fuel combustion in future projects; and neat oxygenates like dimethyl ether in future projects. Fatty acid methyl ester biodiesel and diesel fuel were used as reference fuels. The project objectives were to obtain a significant reduction of carbon dioxide, nitrogen oxide and particulate matter emissions of 70 per cent without drawbacks in efficiency or power output. The presentation also described combustion implementation; milestones at Aalto University School of Science and Technology (TKK); resources at TKK; the main research engine; LEO with EHVA; a literature study on previous research; fuel properties; HVO properties, density; high cetane number in the literature; and high CN effects. Previous studies that were discussed included direct comparisons with no calibrations; heavy duty engine performance; potential with engine calibration; exhaust gas recirculation; and room for new research. In general, standard test runs have been carried out with existing engines without considering the special properties of the fuels. tabs., figs.

  18. [An adenosine triphosphate bioluminescence assay for detecting the number of living cells].

    Science.gov (United States)

    Liu, S; Peng, Z; Wang, H; Lou, J; He, B; Tang, Q; Qiu, D

    2000-06-01

    The method for detecting the number of living cells was studied. Using an adenosine triphosphate (ATP) bioluminescence assay, the present authors reported a perfect linear relationship between lg ATP concentrations and lg luminescence counts (r = 0.9963) as well as a relationship between lg number of cells and lg ATP luminescence counts (r = 0.9922). The detectable cells ranged from 10(2) to 10(6) cells/ml, the coefficients of variation 1-3%. This method is simple, accurate and sensitive and has a high reproducibility.

  19. Turbulence measurements in high Reynolds number boundary layers

    Science.gov (United States)

    Vallikivi, Margit; Smits, Alexander

    2013-11-01

    Measurements are conducted in zero pressure gradient turbulent boundary layers for Reynolds numbers from Reθ = 9,000 to 225,000. The experiments were performed in the High Reynolds number Test Facility (HRTF) at Princeton University, which uses compressed air as the working fluid. Nano-Scale Thermal Anemometry Probes (NSTAPs) are used to acquire data with very high spatial and temporal precision. These new data are used to study the scaling behavior of the streamwise velocity fluctuations in the boundary layer and make comparisons with the scaling of other wall-bounded turbulent flows. Supported under ONR Grant N00014-09-1-0263 (program manager Ron Joslin) and NSF Grant CBET-1064257 (program manager Henning Winter).

  20. Distribution of plasmoids in high-Lundquist-number magnetic reconnection.

    Science.gov (United States)

    Huang, Yi-Min; Bhattacharjee, A

    2012-12-28

    The distribution function f(ψ) of magnetic flux ψ in plasmoids formed in high-Lundquist-number current sheets is studied by means of an analytic phenomenological model and direct numerical simulations. The distribution function is shown to follow a power law f(ψ)∼ψ(-1), which differs from other recent theoretical predictions. Physical explanations are given for the discrepant predictions of other theoretical models.

  1. An optimised direct lysis method for gene expression studies on low cell numbers.

    Science.gov (United States)

    Le, Anh Viet-Phuong; Huang, Dexing; Blick, Tony; Thompson, Erik W; Dobrovic, Alexander

    2015-08-05

    There is increasing interest in gene expression analysis of either single cells or limited numbers of cells. One such application is the analysis of harvested circulating tumour cells (CTCs), which are often present in very low numbers. A highly efficient protocol for RNA extraction, which involves a minimal number of steps to avoid RNA loss, is essential for low input cell numbers. We compared several lysis solutions that enable reverse transcription (RT) to be performed directly on the cell lysate, offering a simple rapid approach to minimise RNA loss for RT. The lysis solutions were assessed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in low cell numbers isolated from four breast cancer cell lines. We found that a lysis solution containing both the non-ionic detergent (IGEPAL CA-630, chemically equivalent to Nonidet P-40 or NP-40) and bovine serum albumin (BSA) gave the best RT-qPCR yield. This direct lysis to reverse transcription protocol outperformed a column-based extraction method using a commercial kit. This study demonstrates a simple, reliable, time- and cost-effective method that can be widely used in any situation where RNA needs to be prepared from low to very low cell numbers.

  2. Tracking the Invasion of Small Numbers of Cells in Paper-Based Assays with Quantitative PCR.

    Science.gov (United States)

    Truong, Andrew S; Lochbaum, Christian A; Boyce, Matthew W; Lockett, Matthew R

    2015-11-17

    Paper-based scaffolds are an attractive material for culturing mammalian cells in a three-dimensional environment. There are a number of previously published studies, which utilize these scaffolds to generate models of aortic valves, cardiac ischemia and reperfusion, and solid tumors. These models have largely relied on fluorescence imaging and microscopy to quantify cells in the scaffolds. We present here a polymerase chain reaction (PCR)-based method, capable of quantifying multiple cell types in a single culture with the aid of DNA barcodes: unique sequences of DNA introduced to the genome of individual cells or cell types through lentiviral transduction. PCR-based methods are highly specific and are amenable to high-throughput and multiplexed analyses. To validate this method, we engineered two different breast cancer lines to constitutively express either a green or red fluorescent protein. These cells lines allowed us to directly compare the ability of fluorescence imaging (of the fluorescent proteins) and qPCR (of the unique DNA sequences of the fluorescent proteins) to quantify known numbers of cells in the paper based-scaffolds. We also used both methods to quantify the distribution of these breast cell lines in homotypic and heterotypic invasion assays. In the paper-based invasion assays, a single sheet of paper containing cells suspended in a hydrogel was sandwiched between sheets of paper containing only hydrogel. The stack was incubated, and the cells invaded the adjacent layers. The individual sheets of the invasion assay were then destacked and the number of cells in each layer quantified. Our results show both methods can accurately detect cell populations of greater than 500 cells. The qPCR method can repeatedly and accurately detect as few as 50 cells, allowing small populations of highly invasive cells to be detected and differentiated from other cell types.

  3. Increased mast cell numbers in a calcaneal tendon overuse model

    DEFF Research Database (Denmark)

    Pingel, Jessica; Wienecke, Jacob; Kongsgaard Madsen, Mads

    2013-01-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar ra...

  4. Vortex Tubes in Turbulence Velocity Fields at High Reynolds Numbers

    CERN Document Server

    Mouri, H

    2008-01-01

    The elementary structures of turbulence, i.e., vortex tubes, are studied using velocity data obtained in laboratory experiments for boundary layers and duct flows at microscale Reynolds numbers 332-1934. While past experimental studies focused on intense vortex tubes, the present study focuses on all vortex tubes with various intensities. We obtain the mean velocity profile. The radius scales with the Kolmogorov length. The circulation velocity scales with the Kolmogorov velocity, in contrast to the case of intense vortex tubes alone where the circulation velocity scales with the rms velocity fluctuation. Since these scaling laws are independent of the configuration for turbulence production, they appear to be universal at high Reynolds numbers.

  5. Shear-driven dynamo waves at high magnetic Reynolds number.

    Science.gov (United States)

    Tobias, S M; Cattaneo, F

    2013-05-23

    Astrophysical magnetic fields often display remarkable organization, despite being generated by dynamo action driven by turbulent flows at high conductivity. An example is the eleven-year solar cycle, which shows spatial coherence over the entire solar surface. The difficulty in understanding the emergence of this large-scale organization is that whereas at low conductivity (measured by the magnetic Reynolds number, Rm) dynamo fields are well organized, at high Rm their structure is dominated by rapidly varying small-scale fluctuations. This arises because the smallest scales have the highest rate of strain, and can amplify magnetic field most efficiently. Therefore most of the effort to find flows whose large-scale dynamo properties persist at high Rm has been frustrated. Here we report high-resolution simulations of a dynamo that can generate organized fields at high Rm; indeed, the generation mechanism, which involves the interaction between helical flows and shear, only becomes effective at large Rm. The shear does not enhance generation at large scales, as is commonly thought; instead it reduces generation at small scales. The solution consists of propagating dynamo waves, whose existence was postulated more than 60 years ago and which have since been used to model the solar cycle.

  6. Passage number of porcine embryonic germ cells affects epigenetic status and blastocyst rate following somatic cell nuclear transfer.

    Science.gov (United States)

    Li, Juan; Gao, Yu; Petkov, Stoyan; Purup, Stig; Hyttel, Poul; Callesen, Henrik

    2014-06-10

    Epigenetic instability of donor cells due to long-term in vitro culture may influence the success rate of subsequent somatic cell nuclear transfer (SCNT). Therefore, the present study was designed (1) to investigate the epigenetic changes after prolonged culture in vitro of porcine embryonic germ (EG) cells, including differences in expression levels of both DNA methylation and demethylation-related genes and catalyses of histone modifications, and (2) to assess the efficiency of SCNT using EG cells from different passages. Results showed that genes either associated with DNA demethylation including DNMTs and TET1 or genes related to histone acetylation including HDACs were highly expressed in EG cells at higher passages when compared to EG cells at lower passages. In addition, the expression level of H3K27me3 functional methylase EZH2 increased while no changes were observed on H3K27me3 demethylase JMJD3 in relation to passage number. Moreover, the expression levels of both the H3K4me3 methylase MLL1 and the H3K4me3 demethylase RBP2 were increased at high passages. By using lower passage (numbers 3-5) EG cells as donor cells, the SCNT efficiency was significantly lower compared with use of fetal fibroblast donor cells. However, similar blastocyst rates were achieved when using higher passage (numbers 9-12) EG cells as donor cells. In conclusion, the present study suggests that the epigenetic status of EG cells change with increasing passage numbers, and that higher passage number EG cells are better primed for SCNT.

  7. DSMC Simulation of High Mach Number Taylor-Couette Flow

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The main focus of this work is to characterise the Taylor-Couette flow of an ideal gas between two coaxial cylinders at Mach number Ma = (U_w /√{ kbT_w / m }) in the range 0.01 Boltzmann constant. The cylindrical surfaces are specified as being diffusely reflecting with the thermal accommodation coefficient equal to one. In the present analysis of high Mach number compressible Taylor-Couette flow using DSMC method, wall slip in the temperature and the velocities are found to be significant. Slip occurs because the temperature/velocity of the molecules incident on the wall could be very different from that of the wall, even though the temperature/velocity of the reflected molecules is equal to that of the wall. Due to the high surface speed of the inner cylinder, significant heating of the gas is taking place. The gas temperature increases until the heat transfer to the surface equals the work done in moving the surface. The highest temperature is obtained near the moving surface of the inner cylinder at a radius of about (1.26 r_1).

  8. NucleoCounter—An efficient technique for the determination of cell number and viability in animal cell culture processes

    OpenAIRE

    Shah, Dimpalkumar; Naciri, Mariam; Clee, Paul; Al-Rubeai, Mohamed

    2006-01-01

    The NucleoCounter is a novel, portable cell counting device based on the principle of fluorescence microscopy. The present work establishes its use with animal cells and checks its reliability, consistency and accuracy in comparison with other cytometric techniques. The main advantages of this technique are its ability to handle a large number of samples with a high degree of precision and its simplicity and specificity in detecting viable cells quantitatively in a heterogeneous culture. The ...

  9. NucleoCounter—An efficient technique for the determination of cell number and viability in animal cell culture processes

    OpenAIRE

    Shah, Dimpalkumar; Naciri, Mariam; Clee, Paul; Al-Rubeai, Mohamed

    2006-01-01

    The NucleoCounter is a novel, portable cell counting device based on the principle of fluorescence microscopy. The present work establishes its use with animal cells and checks its reliability, consistency and accuracy in comparison with other cytometric techniques. The main advantages of this technique are its ability to handle a large number of samples with a high degree of precision and its simplicity and specificity in detecting viable cells quantitatively in a heterogeneous culture. The ...

  10. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...... temperature allows for utilization of the excess heat for fuel processing. Moreover, it provides an excellent CO tolerance of several percent, and the system needs no purification of hydrogen from a reformer. Continuous service for over 6 months at 150°C has been demonstrated....

  11. High Reynolds number magnetohydrodynamic turbulence using a Lagrangian model.

    Science.gov (United States)

    Graham, J Pietarila; Mininni, P D; Pouquet, A

    2011-07-01

    With the help of a model of magnetohydrodynamic (MHD) turbulence tested previously, we explore high Reynolds number regimes up to equivalent resolutions of 6000(3) grid points in the absence of forcing and with no imposed uniform magnetic field. For the given initial condition chosen here, with equal kinetic and magnetic energy, the flow ends up being dominated by the magnetic field, and the dynamics leads to an isotropic Iroshnikov-Kraichnan energy spectrum. However, the locally anisotropic magnetic field fluctuations perpendicular to the local mean field follow a Kolmogorov law. We find that the ratio of the eddy turnover time to the Alfvén time increases with wave number, contrary to the so-called critical balance hypothesis. Residual energy and helicity spectra are also considered; the role played by the conservation of magnetic helicity is studied, and scaling laws are found for the magnetic helicity and residual helicity spectra. We put these results in the context of the dynamics of a globally isotropic MHD flow that is locally anisotropic because of the influence of the strong large-scale magnetic field, leading to a partial equilibration between kinetic and magnetic modes for the energy and the helicity.

  12. Hysteresis phenomenon of hypersonic inlet at high Mach number

    Science.gov (United States)

    Jiao, Xiaoliang; Chang, Juntao; Wang, Zhongqi; Yu, Daren

    2016-11-01

    When the hypersonic inlet works at a Mach number higher than the design value, the hypersonic inlet is started with a regular reflection of the external compression shock at the cowl, whereas a Mach reflection will result in the shock propagating forwards to cause a shock detachment at the cowl lip, which is called "local unstart of inlet". As there are two operation modes of hypersonic inlet at high Mach number, the mode transition may occur with the operation condition of hypersonic inlet changing. A cowl-angle-variation-induced hysteresis and a downstream-pressure-variation-induced hysteresis in the hypersonic inlet start↔local unstart transition are obtained by viscous numerical simulations in this paper. The interaction of the external compression shock and boundary layer on the cowl plays a key role in the hysteresis phenomenon. Affected by the transition of external compression shock reflection at the cowl and the transition between separated and attached flow on the cowl, a hysteresis exists in the hypersonic inlet start↔local unstart transition. The hysteresis makes the operation of a hypersonic inlet very difficult to control. In order to avoid hysteresis phenomenon and keep the hypersonic inlet operating in a started mode, the control route should never pass through the local unstarted boundary.

  13. [Number, viability, and diversity of the filterable forms of prokaryotes in sphagnous high-moor peat].

    Science.gov (United States)

    Lysak, L V; Lapygina, E V; Kadulin, M S; Konova, I A

    2014-01-01

    The number, potential viability, and taxonomic diversity (at the level of phylum) of the filterable forms of prokaryotes (FFP) are estimated in the main genetic horizons of high-moor peat. It was shown that the number of FFP reached 500 million cells in 1 g, i.e., up to 5% of the general size bacteria. The portion of viable cells among FFP (93-98%) was higher than that for the general size bacteria (60-68%). FISH-analysis (fluorescence in situ hybridization) showed that FFP contained the same phylogenetic groups as the population of general size bacteria (domain Archea and phylum Actinobacteria, Cytophaga, and Proteobacteria of the domain Bacteria).

  14. Turbomachinery for Low-to-High Mach Number Flight

    Science.gov (United States)

    Tan, Choon S.; Shah, Parthiv N.

    2004-01-01

    The thrust capability of turbojet cycles is reduced at high flight Mach number (3+) by the increase in inlet stagnation temperature. The 'hot section' temperature limit imposed by materials technology sets the maximum heat addition and, hence, sets the maximum flight Mach number of the operating envelope. Compressor pre-cooling, either via a heat exchanger or mass-injection, has been suggested as a means to reduce compressor inlet temperature and increase mass flow capability, thereby increasing thrust. To date, however, no research has looked at compressor cooling (i.e., using a compressor both to perform work on the gas path air and extract heat from it simultaneously). We wish to assess the feasibility of this novel concept for use in low-to-high Mach number flight. The results to-date show that an axial compressor with cooling: (1) relieves choking in rear stages (hence opening up operability), (2) yields higher-pressure ratio and (3) yields higher efficiency for a given corrected speed and mass flow. The performance benefit is driven: (i) at the blade passage level, by a decrease in the total pressure reduction coefficient and an increase in the flow turning; and (ii) by the reduction in temperature that results in less work required for a given pressure ratio. The latter is a thermodynamic effect. As an example, calculations were performed for an eight-stage compressor with an adiabatic design pressure ratio of 5. By defining non-dimensional cooling as the percentage of compressor inlet stagnation enthalpy removed by a heat sink, the model shows that a non-dimensional cooling of percent in each blade row of the first two stages can increase the compressor pressure ratio by as much as 10-20 percent. Maximum corrected mass flow at a given corrected speed may increase by as much as 5 percent. In addition, efficiency may increase by as much as 5 points. A framework for characterizing and generating the performance map for a cooled compressor has been developed

  15. Bio-electrospraying and droplet-based microfluidics: control of cell numbers within living residues

    Energy Technology Data Exchange (ETDEWEB)

    Hong Jongin; DeMello, Andrew J [Nanostructured Materials and Devices Group, Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Jayasinghe, Suwan N, E-mail: a.demello@imperial.ac.u, E-mail: s.jayasinghe@ucl.ac.u [BioPhysics Group, Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2010-04-15

    Bio-electrospraying (BES) has demonstrated great promise as a rapidly evolving strategy for tissue engineering and regenerative biology/medicine. Since its discovery in 2005, many studies have confirmed that cells (immortalized, primary and stem cells) and whole organisms (Danio rerio, Xenopus tropicalis, Caenorhabditis elegans to Drosophila) remain viable post-bio-electrospraying. Although this bio-protocol has achieved much, it suffers from one crucial problem, namely the ability to precisely control the number of cells within droplets and or encapsulations. If overcome, BES has the potential to become a high-efficiency biotechnique for controlled cell encapsulation, a technique most useful for a wide range of applications in biology and medicine ranging from the forming of three-dimensional cultures to an approach for treating diseases such as type I diabetes. In this communication, we address this issue by demonstrating the coupling of BES with droplet-based microfluidics for controlling live cell numbers within droplets and residues. (communication)

  16. Efficient analysis of a small number of cancer cells at the single-cell level using an electroactive double-well array.

    Science.gov (United States)

    Kim, Soo Hyeon; Fujii, Teruo

    2016-07-01

    Analysis of the intracellular materials of a small number of cancer cells at the single-cell level is important to improve our understanding of cellular heterogeneity in rare cells. To analyze an extremely small number of cancer cells (less than hundreds of cells), an efficient system is required in order to analyze target cells with minimal sample loss. Here, we present a novel approach utilizing an advanced electroactive double-well array (EdWA) for on-chip analysis of a small number of cancer cells at the single-cell level with minimal loss of target cells. The EdWA consisted of cell-sized trap-wells for deterministic single-cell trapping using dielectrophoresis and high aspect ratio reaction-wells for confining the cell lysates extracted by lysing trapped single cells via electroporation. We demonstrated a highly efficient single-cell arraying (a cell capture efficiency of 96 ± 3%) by trapping diluted human prostate cancer cells (PC3 cells). On-chip single-cell analysis was performed by measuring the intracellular β-galactosidase (β-gal) activity after lysing the trapped single cells inside a tightly enclosed EdWA in the presence of a fluorogenic enzyme substrate. The PC3 cells showed large cell-to-cell variations in β-gal activity although they were cultured under the same conditions in a culture dish. This simple and effective system has great potential for high throughput single-cell analysis of rare cells.

  17. Lumley decomposition of turbulent boundary layer at high Reynolds numbers

    Science.gov (United States)

    Tutkun, Murat; George, William K.

    2017-02-01

    The decomposition proposed by Lumley in 1966 is applied to a high Reynolds number turbulent boundary layer. The experimental database was created by a hot-wire rake of 143 probes in the Laboratoire de Mécanique de Lille wind tunnel. The Reynolds numbers based on momentum thickness (Reθ) are 9800 and 19 100. Three-dimensional decomposition is performed, namely, proper orthogonal decomposition (POD) in the inhomogeneous and bounded wall-normal direction, Fourier decomposition in the homogeneous spanwise direction, and Fourier decomposition in time. The first POD modes in both cases carry nearly 50% of turbulence kinetic energy when the energy is integrated over Fourier dimensions. The eigenspectra always peak near zero frequency and most of the large scale, energy carrying features are found at the low end of the spectra. The spanwise Fourier mode which has the largest amount of energy is the first spanwise mode and its symmetrical pair. Pre-multiplied eigenspectra have only one distinct peak and it matches the secondary peak observed in the log-layer of pre-multiplied velocity spectra. Energy carrying modes obtained from the POD scale with outer scaling parameters. Full or partial reconstruction of turbulent velocity signal based only on energetic modes or non-energetic modes revealed the behaviour of urms in distinct regions across the boundary layer. When urms is based on energetic reconstruction, there exists (a) an exponential decay from near wall to log-layer, (b) a constant layer through the log-layer, and (c) another exponential decay in the outer region. The non-energetic reconstruction reveals that urms has (a) an exponential decay from the near-wall to the end of log-layer and (b) a constant layer in the outer region. Scaling of urms using the outer parameters is best when both energetic and non-energetic profiles are combined.

  18. High accuracy semidefinite programming bounds for kissing numbers

    NARCIS (Netherlands)

    Mittelmann, H.D.; Vallentin, F.

    2009-01-01

    The kissing number in n-dimensional Euclidean space is the maximal number of non-overlapping unit spheres which simultaneously can touch a central unit sphere. Bachoc and Vallentin developed a method to find upper bounds for the kissing number based on semidefinite programming. This paper is a repor

  19. High accuracy semidefinite programming bounds for kissing numbers

    NARCIS (Netherlands)

    H.D. Mittelmann; F. Vallentin (Frank)

    2010-01-01

    htmlabstractThe kissing number in n-dimensional Euclidean space is the maximal number of non-overlapping unit spheres which simultaneously can touch a central unit sphere. Bachoc and Vallentin developed a method to find upper bounds for the kissing number based on semidefinite programming. This

  20. High accuracy semidefinite programming bounds for kissing numbers

    NARCIS (Netherlands)

    H.D. Mittelmann; F. Vallentin (Frank)

    2009-01-01

    htmlabstractThe kissing number in n-dimensional Euclidean space is the maximal number of non-overlapping unit spheres which simultaneously can touch a central unit sphere. Bachoc and Vallentin developed a method to find upper bounds for the kissing number based on semidefinite programming. This

  1. Stereological estimation of total cell numbers in the young human utricular macula

    DEFF Research Database (Denmark)

    Severinsen, Stig Avall; Sørensen, Mads Sølvsten; Kirkegaard, Mette

    2010-01-01

    Abstract Conclusion: There is no change in the total cell population and hair cell:supporting cell ratio in the human utricular macula from gestational week 16 and onwards, whereas the lower hair cell:supporting cell ratio and lower total number of cells in the youngest specimens indicate....... The optical fractionator was used to estimate the total number of cells in the utricular macula. Results: The total cell number was found to be 143 000 in subjects older than gestational week 16. The number of hair cells and supporting cells did not change between the 16th gestational week and 15 years...... and was 36 000 and 107 000, respectively. In the youngest specimen (10th and 12th gestational week) there was a statistically significant lower total number of cells (62 000) and a lower hair cell:supporting cell ratio, resulting in a mean number of 13 000 hair cells and 49 000 supporting cells....

  2. The Relationship between Cell Number, Division Behavior and Developmental Potential of Cleavage Stage Human Embryos: A Time-Lapse Study.

    Science.gov (United States)

    Kong, Xiangyi; Yang, Shuting; Gong, Fei; Lu, Changfu; Zhang, Shuoping; Lu, Guangxiu; Lin, Ge

    2016-01-01

    Day 3 cleavage embryo transfer is routine in many assisted reproductive technology centers today. Embryos are usually selected according to cell number, cell symmetry and fragmentation for transfer. Many studies have showed the relationship between cell number and embryo developmental potential. However, there is limited understanding of embryo division behavior and their association with embryo cell number and developmental potential. A retrospective and observational study was conducted to investigate how different division behaviors affect cell number and developmental potential of day 3 embryos by time-lapse imaging. Based on cell number at day 3, the embryos (from 104 IVF/intracytoplasmic sperm injection (ICSI) treatment cycles, n = 799) were classified as follows: less than 5 cells (10C; n = 42). Division behavior, morphokinetic parameters and blastocyst formation rate were analyzed in 5 groups of day 3 embryos with different cell numbers. In 10C embryos increased compared to 7-8C embryos (45.8%, 33.3% vs. 11.1%, respectively). In ≥5C embryos, FR and DC significantly reduced developmental potential, whereas division behaviors. In NB embryos, the blastocyst formation rate increased with cell number from 7.4% (10C). In NB embryos, the cell cycle elongation or shortening was the main cause for abnormally low or high cell number, respectively. After excluding embryos with abnormal division behaviors, the developmental potential, implantation rate and live birth rate of day 3 embryos increased with cell number.

  3. Statistics of High Atwood Number Turbulent Mixing Layers

    Science.gov (United States)

    Baltzer, Jon; Livescu, Daniel

    2015-11-01

    The statistical properties of incompressible shear-driven planar mixing layers between two miscible streams of fluids with different densities are investigated by means of Direct Numerical Simulations. The simulations begin from a thin interface perturbed by a thin broadband random disturbance, and the mixing layers are allowed to develop to self-similar states. The temporal simulations are performed in unprecedented domain sizes, with grid sizes up to 6144 x 2048 x 1536, which allows turbulent structures to grow and merge naturally. This allows the flow to reach states far-removed from the initial disturbances, thereby enabling high-quality statistics to be obtained for higher moments, pdfs, and other quantities critical to developing closure models. A wide range of Atwood numbers are explored, ranging from nearly constant density to At=0.87. The consequences of increasing the density contrast are investigated for global quantities, such as growth rates, and asymmetries that form in statistical profiles. Additional simulations in smaller domains are performed to study the effects of domain size.

  4. Interaction of two high Reynolds number axisymmetric turbulent wakes

    Science.gov (United States)

    Obligado, M.; Klein, S.; Vassilicos, J. C.

    2015-11-01

    With the recent discovery of non-equilibrium high Reynolds number scalings in the wake of axisymmetric plates (Nedic et al., PRL, 2013), it has become of importance to develop an experimental technique that permits to easily discriminate between different wake scalings. We propose an experimental setup that tests the presence of non-equilibrium turbulence using the streamwise variation of velocity fluctuations between two bluff bodies facing a flow. We have studied two different sets of plates (one with regular and another with irregular peripheries) with Hot-Wire Anemometry in a wind tunnel. By acquiring streamwise profiles for different plate separations and identifying the wake interaction length for each separation it is possible to estimate the streamwise evolution of the single wake width. From this evolution it is also possible to deduce the turbulence dissipation scalings. This work generalizes previous studies on the interaction of plane wakes (see Gomes-Fernandes et al., JFM, 2012) to include axisymmetric wakes. We find that the wake interaction length proposed in this cited work and a constant anisotropy assumption can be used to collapse the streamwise developments of the first three moments.

  5. Universal decay of high Reynolds number Taylor-Couette turbulence

    CERN Document Server

    Verschoof, Ruben A; van der Veen, Roeland C A; Sun, Chao; Lohse, Detlef

    2015-01-01

    We study the decay of high-Reynolds number Taylor-Couette turbulence, i.e. the turbulent flow between two coaxial rotating cylinders. To do so, the rotation of the inner cylinder ($Re_i = 2 \\cdot 10^6$, the outer cylinder is at rest) was suddenly stopped. Using a combination of laser Doppler anemometry and particle image velocimetry measurements, six decay decades of the kinetic energy could be captured. First, in the absence of cylinder rotation, the flow-velocity during the decay does not develop any height dependence in contrast to the well-known Taylor vortex state. Next, the radial profile of the azimuthal velocity is found to be self-similar, i.e. when normalizing it with the mean velocity, it is universal. Nonetheless, the decay of this wall-bounded inhomogeneous turbulent flow does not follow a strict power law as for decaying turbulent homogeneous isotropic flows, but it is faster, due to the strong viscous drag applied by the bounding walls. We theoretically describe the decay in a quantitative way ...

  6. Regulatory T cell number in multiple sclerosis patients: A meta-analysis.

    Science.gov (United States)

    Noori-Zadeh, Ali; Mesbah-Namin, Seyed Alireza; Bistoon-Beigloo, Sara; Bakhtiyari, Salar; Abbaszadeh, Hojjat-Allah; Darabi, Shahram; Rajabibazl, Masoumeh; Abdanipour, Alireza

    2016-01-01

    Regulatory T cells (Treg cells), defined as CD4(+) CD25(+) FoxP3(+) T cells by expression of CD4, high-affinity IL-2 receptor and the transcription factor, forkhead box P3 (FoxP3). They play a pivotal role in protecting individuals from autoimmunity and a growing body of evidence suggests their role in the prevention of multiple sclerosis development. However, there are discrepancies about the type of defect in the Treg cells of multiple sclerosis patients and especially whether the Treg number alteration could be contributed to multiple sclerosis pathogenesis. Indeed, whether low number of Treg cells can be a risk factor contributing to multiple sclerosis pathogenesis is the matter of debate and there is not any comprehensive agreement on it. Thus, the objective of this systematic review and meta-analysis was to precisely quantify the nature and magnitude of the association between Treg cell number and the risk ratio/odds ratio (OR) of multiple sclerosis in the case-control studies. Hence, medical databases of Embase, PubMed/Medline, PubMed, PubMed Central and SCOPUS were searched for empirical papers using "Regulatory T cell frequency", "Treg frequency" in combination with "multiple sclerosis". In the case-control studies, papers were reviewed for inclusion/exclusion criteria and 8 publications were included. Under random-effect model meta-analysis the data showed that the frequency of Treg cells was not a risk factor in multiple sclerosis using current laboratory methods.

  7. Performance of PEM fuel cells stack as affected by number of cell and gas flow-rate

    Science.gov (United States)

    Syampurwadi, A.; Onggo, H.; Indriyati; Yudianti, R.

    2017-03-01

    The proton exchange membrane fuel cell (PEMFC) is a promising technology as an alternative green energy due to its high power density, low operating temperatures, low local emissions, quiet operation and fast start up-shutdown. In order to apply fuel cell as portable power supply, the performance investigation of small number of cells is needed. In this study, PEMFC stacks consisting of 1, 3, 5 and 7-cells with an active area of 25 cm2 per cell have been designed and developed. Their was evaluated in variation of gas flow rate. The membrane electrode assembly (MEA) was prepared by hot-pressing commercial gas diffusion electrodes (Pt loading 0.5 mg/cm2) on pre-treated Nafion 117 membrane. The stacks were constructed using bipolar plates in serpentine pattern and Z-type gas flow configuration. The experimental results were presented as polarization and power output curves which show the effects of varying number of cells and H2/O2 flow-rates on the PEMFC performance. The experimental results showed that not only number of cells and gas flow-rates affected the fuel cells performance, but also the operating temperature as a result of electrochemistry reaction inside the cell.

  8. Enhancing yields of low and single copy number plasmid DNAs from Escherichia coli cells.

    Science.gov (United States)

    Wood, Whitney N; Smith, Kyle D; Ream, Jennifer A; Kevin Lewis, L

    2017-02-01

    Many plasmids used for gene cloning and heterologous protein expression in Escherichia coli cells are low copy number or single copy number plasmids. The extraction of these types of plasmids from small bacterial cell cultures produces low DNA yields. In this study, we have quantitated yields of low copy and single copy number plasmid DNAs after growth of cells in four widely used broths (SB, SOC, TB, and 2xYT) and compared results to those obtained with LB, the most common E. coli cell growth medium. TB (terrific broth) consistently generated the greatest amount of plasmid DNA, in agreement with its ability to produce higher cell titers. The superiority of TB was primarily due to its high levels of yeast extract (24g/L) and was independent of glycerol, a unique component of this broth. Interestingly, simply preparing LB with similarly high levels of yeast extract (LB24 broth) resulted in plasmid yields that were equivalent to those of TB. By contrast, increasing ampicillin concentration to enhance plasmid retention did not improve plasmid DNA recovery. These experiments demonstrate that yields of low and single copy number plasmid DNAs from minipreps can be strongly enhanced using simple and inexpensive media. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Helicon waves in uniform plasmas. II. High m numbers

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2015-09-15

    Helicons are whistler modes with azimuthal wave numbers. They have been studied in solids and plasmas where boundaries play a role. The present work shows that very similar modes exist in unbounded gaseous plasmas. Instead of boundaries, the antenna properties determine the topology of the wave packets. The simplest antenna is a magnetic loop which excites m = 0 or m = 1 helicons depending on whether the dipole moment is aligned parallel or perpendicular to the ambient background magnetic field B{sub 0}. While these low order helicons have been described by J. M. Urrutia and R. L. Stenzel [“Helicon modes in uniform plasmas. I. Low m modes,” Phys. Plasmas 22, 092111 (2015)], the present work focuses on high order modes up to m = 8. These are excited by antenna arrays forming magnetic multipoles. Their wave magnetic field has been measured in space and time in a large and uniform laboratory plasma free of boundary effects. The observed wave topology exhibits m pairs of unique field line spirals which may have inspired the name “helicon” to this mode. All field lines converge into these nested spirals which propagate like corkscrews along B{sub 0}. The field lines near the axis of helicons are perpendicular to B{sub 0} and circularly polarized as in parallel whistlers. Helical antennas couple to these transverse fields but not to the spiral fields of helicons. Using a circular antenna array of phased m = 0 loops, right or left rotating or non-rotating multipole antenna fields are generated. They excite m < 0 and m > 0 modes, showing that the plasma supports both modes equally well. The poor excitation of m < 0 modes is a characteristic of loops with dipole moment across B{sub 0}. The radiation efficiency of multipole antennas has been found to decrease with m.

  10. Dissipation in dynamos at low and high magnetic Prandtl numbers

    CERN Document Server

    Brandenburg, A

    2010-01-01

    Using simulations of helically driven turbulence, it is shown that the ratio of kinetic to magnetic energy dissipation scales with the magnetic Prandtl number in power law fashion with an exponent of approximately 0.6. Over six orders of magnitude in the magnetic Prandtl number the magnetic field is found to be sustained by large-scale dynamo action of alpha-squared type. This work extends a similar finding for small magnetic Prandtl numbers to the regime of large magnetic Prandtl numbers. At large magnetic Prandtl numbers, most of the energy is dissipated viscously, lowering thus the amount of magnetic energy dissipation, which means that simulations can be performed at magnetic Reynolds numbers that are large compared to the usual limits imposed by a given resolution. This is analogous to an earlier finding that at small magnetic Prandtl numbers, most of the energy is dissipated resistively, lowering the amount of kinetic energy dissipation, so simulations can then be performed at much larger fluid Reynolds...

  11. Accurate determination of plasmid copy number of flow-sorted cells using droplet digital PCR.

    Science.gov (United States)

    Jahn, Michael; Vorpahl, Carsten; Türkowsky, Dominique; Lindmeyer, Martin; Bühler, Bruno; Harms, Hauke; Müller, Susann

    2014-06-17

    Many biotechnological processes rely on the expression of a plasmid-based target gene. A constant and sufficient number of plasmids per cell is desired for efficient protein production. To date, only a few methods for the determination of plasmid copy number (PCN) are available, and most of them average the PCN of total populations disregarding heterogeneous distributions. Here, we utilize the highly precise quantification of DNA molecules by droplet digital PCR (ddPCR) and combine it with cell sorting using flow cytometry. A duplex PCR assay was set up requiring only 1000 sorted cells for precise determination of PCN. The robustness of this method was proven by thorough optimization of cell sorting, cell disruption, and PCR conditions. When non plasmid-harboring cells of Pseudomonas putida KT2440 were spiked with different dilutions of the expression plasmid pA-EGFP_B, a PCN from 1 to 64 could be accurately detected. As a proof of principle, induced cultures of P. putida KT2440 producing an EGFP-fused model protein by means of the plasmid pA-EGFP_B were investigated by flow cytometry and showed two distinct subpopulations, fluorescent and nonfluorescent cells. These two subpopulations were sorted for PCN determination with ddPCR. A remarkably diverging plasmid distribution was found within the population, with nonfluorescent cells showing a much lower PCN (≤1) than fluorescent cells (PCN of up to 5) under standard conditions.

  12. Does the number of irradiated cells influence the spatial distribution of bystander effects?

    Science.gov (United States)

    Belchior, A; Balásházy, I; Monteiro Gil, O; Vaz, P; Almeida, P

    2014-12-01

    There is growing evidence that the radiation effects at low doses are not adequately described by a simple linear extrapolation from high doses, due, among others, to bystander effects. Though several studies have been published on this topic, the explanation of the mechanisms describing the bystander effects remains unclear. This study aims at understanding how the bystander signals are or can be propagated in the cell culture, namely if the number of irradiated cells influences the bystander response. An A549 cell line was exposed to several doses of α-particles, being the bystander response quantified in two non-irradiated areas. The radius of irradiated areas differs by a factor of 2, and the non-irradiated areas were optimally designed to have the same number of cells. Our results show evidence for bystander effects occurring in cells far away from the irradiated ones, meaning that bystander signals can easily spread throughout the cell culture. Additionally, our study highlights that the damage caused by radiation on the surrounding of irradiated areas could be different according to the number of irradiated cells, i.e., for the same dose value; the overall cellular damage could be different.

  13. The effect of cell passage number on osteogenic and adipogenic characteristics of D1 cells.

    Science.gov (United States)

    Kwist, K; Bridges, W C; Burg, K J L

    2016-08-01

    Cell line passage number is an important consideration when designing an experiment. At higher passages, it is generally understood that cell health begins to decline and, when this occurs, the result can be variable data. However, there are no specific guidelines regarding optimal passage range, and this information is dependent on cell type. To explore these variabilities, low passage D1 cells were thawed (passage 3) and passaged serially until a much higher number (passage 34). Samples were taken every five passages and analyzed for alkaline phosphatase and triglyceride; also, the gene expression of both adipogenic and osteogenic markers was tested. The results indicate that the growth rate of these cells did slow down after passage 30. However, expression of the osteogenic characteristics seemed to cycle, with the highest levels seen at passage 4 and 24. The adipocyte expression levels remained the same throughout the study.

  14. The total chromatic number of regular graphs of high degree

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The total chromatic number χT (G) of a graph G is the minimum number of colors needed to color the edges and the vertices of G so that incident or adjacent elements have distinct colors. We show that if G is a regular graph and d(G) 32 |V (G)| + 263 , where d(G) denotes the degree of a vertex in G, then χT (G) d(G) + 2.

  15. Vortex Shedding from Tapered Cylinders at high Reynolds Numbers

    DEFF Research Database (Denmark)

    Johansson, Jens; Andersen, Michael Styrk; Christensen, Silas Sverre

    2015-01-01

    percent for strakes of circular cross section. The present paper argues that this height can be reduced for structures where the critical wind velocity for vortex shedding is in the Supercritical Reynolds number regime. The present investigations are aimed for suppressing VIV on offshore wind turbine......^5 (Supercritical). Results indicate that circular strakes with a diameter corresponding to 3 percent of the structures mean diameter can be used to efficiently reduce VIV in the Supercritical Reynolds number regime....

  16. Resolving high Reynolds numbers in SPH simulations of subsonic turbulence

    CERN Document Server

    Price, Daniel J

    2011-01-01

    Accounting for the Reynolds number is critical in numerical simulations of turbulence, particularly for subsonic flow. For Smoothed Particle Hydrodynamics (SPH) with constant artificial viscosity coefficient alpha, it is shown that the effective Reynolds number in the absence of explicit physical viscosity terms scales linearly with the Mach number - compared to mesh schemes, where the effective Reynolds number is largely independent of the flow velocity. As a result, SPH simulations with alpha=1 will have low Reynolds numbers in the subsonic regime compared to mesh codes, which may be insufficient to resolve turbulent flow. This explains the failure of Bauer and Springel (2011, arXiv:1109.4413v1) to find agreement between the moving-mesh code AREPO and the GADGET SPH code on simulations of driven, subsonic (v ~ 0.3 c_s) turbulence appropriate to the intergalactic/intracluster medium, where it was alleged that SPH is somehow fundamentally incapable of producing a Kolmogorov-like turbulent cascade. We show tha...

  17. Concomitant high gene copy number and protein overexpression of IGF1R and EGFR negatively affect disease-free survival of surgically resected non-small-cell-lung cancer patients

    Science.gov (United States)

    Flacco, A.; Bianconi, F.; Ragusa, M.; Vannucci, J.; Bellezza, G.; Chiari, R.; Minotti, V.; Pistola, L.; Tofanetti, F. R.; Siggillino, A.; Baldelli, E.; Sidoni, A.; Daddi, N.; Puma, F.; Varella-Garcia, M.; Crinò, L.

    2014-01-01

    Background Insulin-like growth factor 1 receptor (IGF1R) represents a novel molecular target in non-small-cell-lung cancer (NSCLC). IGF1R and epidermal growth factor receptor (EGFR) activation are essential to mediate tumor cell survival, proliferation, and invasion. This study investigates the prognostic role of IGF1R and EGFR in surgically resected NSCLC. Materials and methods IGF1R and EGFR copy number gain (CNG) were tested by fluorescence in situ hybridization (FISH) and protein expression by immunohistochemistry (IHC) in 125 stage I–II–IIIA NSCLC patients. Results Fourty-six tumors (40.3 %) were IGF1R FISH-positive (FISH+), and 76 (67.2 %) were EGFR FISH+. Tumors with concomitant IGF1R/EGFR FISH+ were observed in 34 cases (30.1 %). IGF1R and EGFR FISH+ were associated with SCC histology (p = 0.01 and p = 0.04, respectively). IGF1R and EGFR protein over-expression (IHC+) were detected in 45 (36.0 %) and 69 (55.2 %) cases, respectively. Tumors with concomitant IGF1R/EGFR IHC+ were detected in 31 (24.8 %) patients. IGF1R/EGFR FISH+ and IGF1R/EGFR IHC+ were significantly associated (χ2 = 4.02, p = 0.04). Patients with IGF1R/EGFR FISH+ and IGF1R/EGFR IHC+ were associated with shorter disease-free survival (DFS) (p = 0.05 and p = 0.05, respectively). Patients with concomitant IGF1R/EGFR FISH+/IHC+ had a worse DFS and overall survival (p = 0.005 and p = 0.01, respectively). The multivariate model confirmed that IGF1R/EGFR FISH+/IHC+ (hazard ratio (HR), 4.08; p = 0.01) and tumor stage (II–III vs I) (HR, 4.77; p = 0.003) were significantly associated with worse DFS. Conclusions IGF1R/EGFR FISH+ correlates with IGF1R/EGFR IHC+. IGF1R/EGFR FISH+/IHC+ is an independent negative prognostic factor for DFS in early NSCLC. These features may have important implications for future anti-IGF1R therapeutic approaches. PMID:23314677

  18. Gene expression profiling and gene copy-number changes in malignant mesothelioma cell lines.

    Science.gov (United States)

    Zanazzi, Claudia; Hersmus, Remko; Veltman, Imke M; Gillis, Ad J M; van Drunen, Ellen; Beverloo, H Berna; Hegmans, Joost P J J; Verweij, Marielle; Lambrecht, Bart N; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2007-10-01

    Malignant mesothelioma (MM) is an asbestos-induced tumor that acquires aneuploid DNA content during the tumorigenic process. We used instable MM cell lines as an in vitro model to study the impact of DNA copy-number changes on gene expression profiling, in the course of their chromosomal redistribution process. Two MM cell lines, PMR-MM2 (early passages of in vitro culture) and PMR-MM7 (both early and late passages of in vitro culture), were cytogenetically characterized. Genomic gains and losses were precisely defined using microarray-based comparative genomic hybridization (array-CGH), and minimal overlapping analysis led to the identification of the common unbalanced genomic regions. Using the U133Plus 2.0 Affymetrix gene chip array, we analyzed PMR-MM7 early and late passages for genome-wide gene expression, and correlated the differentially expressed genes with copy-number changes. The presence of a high number of genetic imbalances occurring from early to late culture steps reflected the tendency of MM cells toward genomic instability. The selection of specific chromosomal abnormalities observed during subsequent cultures demonstrated the spontaneous evolution of the cancer cells in an in vitro environment. MM cell lines were characterized by copy-number changes associated with the TP53 apoptotic pathway already present at the first steps of in vitro culture. Prolonged culture led to acquisition of additional chromosomal copy-number changes associated with dysregulation of genes involved in cell adhesion, regulation of mitotic cell cycle, signal transduction, carbohydrate metabolism, motor activity, glycosaminoglycan biosynthesis, protein binding activity, lipid transport, ATP synthesis, and methyltransferase activity.

  19. Crossover from High to Low Reynolds Number Turbulence

    NARCIS (Netherlands)

    Lohse, Detlef

    1994-01-01

    The Taylor-Reynolds and Reynolds number (Re lambda and Re) dependence of the dimensionless energy dissipation rate c epsilon = epsilon L / u31,rms is derived for statistically stationary isotropic turbulence, employing the results of a variable range mean field theory. Here epsilon is the energy di

  20. High-Reynolds Number Taylor-Couette Turbulence

    NARCIS (Netherlands)

    Grossmann, Siegfried; Lohse, Detlef; Sun, Chao

    2016-01-01

    Taylor-Couette flow, the flow between two coaxial co- or counter-rotating cylinders, is one of the paradigmatic systems in the physics of fluids. The (dimensionless) control parameters are the Reynolds numbers of the inner and outer cylinders, the ratio of the cylinder radii, and the aspect ratio. O

  1. Mutagenic Effects of a Single and an Exact Number of α Particles in Mammalian Cells

    Science.gov (United States)

    Hei, Tom K.; Wu, Li-Jun; Liu, Su-Xian; Vannais, Diane; Waldren, Charles A.; Randers-Pehrson, Gerhard

    1997-04-01

    One of the main uncertainties in risk estimation for environmental radon exposure using lung cancer data from underground miners is the extrapolation from high- to low-dose exposure where multiple traversal is extremely rare. The biological effects of a single α particle are currently unknown. Using the recently available microbeam source at the Radiological Research Accelerator Facility at Columbia University, we examined the frequencies and molecular spectrum of S1- mutants induced in human--hamster hybrid (AL) cells by either a single or an exact number of α particles. Exponentially growing cells were stained briefly with a nontoxic concentration of Hoechst dye for image analysis, and the location of individual cells was computer-monitored. The nucleus of each cell was irradiated with either 1,2,4, or 8 α particles at a linear energy transfer of 90 keV/μ m consistent with the energy spectrum of domestic radon exposure. Although single-particle traversal was only slightly cytotoxic to AL cells (survival fraction ≈ 0.82), it was highly mutagenic, and the induced mutant fraction averaged 110 mutants per 105 survivors. In addition, both toxicity and mutant induction were dose-dependent. Multiplex PCR analysis of mutant DNA showed that the proportion of mutants with multilocus deletions increased with the number of particle traversals. These data provide direct evidence that a single α particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.

  2. Dynamic changes in mouse hematopoietic stem cell numbers during aging

    NARCIS (Netherlands)

    de Haan, G; Van Zant, G

    1999-01-01

    To address the fundamental question of whether or not stem cell populations age, we performed quantitative measurements of the cycling status and frequency of hematopoietic stem cells in long-lived C57BL/6 (B6) and short-lived DBA/2 (DBA) mice at different developmental and aging stages. The frequen

  3. High Reynolds number liquid layer flow with flexible walls

    Indian Academy of Sciences (India)

    J S B Gajjar

    2015-05-01

    The stability of liquid layer flow over an inclined flexible wall is studied using asymptotic methods based on the assumption that the Reynolds number is large. The flexible wall behaviour is described by a spring-plate model, and parameters chosen so that the wall flexibility affects the governing boundary layer problem. For the case of a rigid wall, the problem reverts to one studied by Gajjar. Asymptotic analysis of the governing equations leads to the triple-deck equations governing the interaction between the wall layer and the free-surface. The linearised and other solution properties of these set of equations are discussed.

  4. Azimuthal Magnetorotational Instability at low and high magnetic Prandtl numbers

    CERN Document Server

    Guseva, A; Willis, A P; Avila, M

    2016-01-01

    The magnetorotational instability (MRI) is considered to be one of the most powerful sources of turbulence in hydrodynamically stable quasi-Keplerian flows, such as those governing accretion disk flows. Although the linear stability of these flows with applied external magnetic field has been studied for decades, the influence of the instability on the outward angular momentum transport, necessary for the accretion of the disk, is still not well known. In this work we model Keplerian rotation with Taylor-Couette flow and imposed azimuthal magnetic field using both linear and nonlinear approaches. We present scalings of instability with Hartmann and Reynolds numbers via linear analysis and direct numerical simulations (DNS) for the two magnetic Prandtl numbers of $1.4 \\cdot 10^{-6}$ and $1$. Inside of the instability domains modes with different axial wavenumbers dominate, resulting in sub-domains of instabilities, which appear different for each $Pm$. The DNS show the emergence of 1- and 2-frequency spatio-te...

  5. High Reynolds number rough-wall turbulent boundary layers

    Science.gov (United States)

    Squire, Dougal; Morrill-Winter, Caleb; Schultz, Michael; Hutchins, Nicholas; Klewicki, Joseph; Marusic, Ivan

    2015-11-01

    In his review of turbulent flows over rough-walls, Jimenez (2004) concludes that there are gaps in the current database of relevant experiments. The author calls for measurements in which δ / k and k+ are both large--low blockage, fully-rough flow--and where δ / k is large and k+ is small--low blockage, transitionally-rough flow--to help clarify ongoing questions regarding the physics of rough-wall-bounded flows. The present contribution details results from a large set of measurements carried out above sandpaper in the Melbourne Wind Tunnel. The campaign spans 45 rough-wall measurements using single and multiple-wire hot-wire anemometry sensors and particle image velocimetry. A floating element drag balance is employed to obtain the rough-wall skin friction force. The data span 20 number range of 2800 < Reτ < 30000 , targeting areas in the parameter space identified by Jimenez (2004) as being sparsely populated by pre-existing data. Smooth-wall data are also obtained across a similar Reynolds number range to enable comparison of smooth- and rough-wall structural features. Generally, the data indicate similarity in the outer-layer of smooth- and fully-rough wall-bounded flows.

  6. Design of a High-Reynolds Number Recirculating Water Tunnel

    Science.gov (United States)

    Daniel, Libin; Elbing, Brian

    2014-11-01

    An experimental fluid mechanics laboratory focused on turbulent boundary layers, drag reduction techniques, multiphase flows and fluid-structure interactions has recently been established at Oklahoma State University. This laboratory has three primary components; (1) a recirculating water tunnel, (2) a multiphase pipe flow loop, and (3) a multi-scale flow visualization system. The design of the water tunnel is the focus of this talk. The criteria used for the water tunnel design was that it had to produce a momentum-thickness based Reynolds number in excess of 104, negligible flow acceleration due to boundary layer growth, maximize optical access for use of the flow visualization system, and minimize inlet flow non-uniformity. This Reynolds number was targeted to bridge the gap between typical university/commercial water tunnels (103) and the world's largest water tunnel facilities (105) . These objectives were achieved with a 152 mm (6-inch) square test section that is 1 m long and has a maximum flow speed of 10 m/s. The flow non-uniformity was mitigated with the use of a tandem honeycomb configuration, a settling chamber and an 8.5:1 contraction. The design process that produced this final design will be presented along with its current status.

  7. Estimation of absolute microglial cell numbers in mouse fascia dentata using unbiased and efficient stereological cell counting principles.

    Science.gov (United States)

    Wirenfeldt, Martin; Dalmau, Ishar; Finsen, Bente

    2003-11-01

    Stereology offers a set of unbiased principles to obtain precise estimates of total cell numbers in a defined region. In terms of microglia, which in the traumatized and diseased CNS is an extremely dynamic cell population, the strength of stereology is that the resultant estimate is unaffected by shrinkage or expansion of the tissue. The optical fractionator technique is very efficient but requires relatively thick sections (e.g., > or =20 microm after coverslipping) and the unequivocal identification of labeled cells throughout the section thickness. We have adapted our protocol for Mac-1 immunohistochemical visualization of microglial cells in thick (70 microm) vibratome sections for stereological counting within the murine hippocampus, and we have compared the staining results with other selective microglial markers: the histochemical demonstration of nucleotide diphosphatase (NDPase) activity and the tomato lectin histochemistry. The protocol gives sections of high quality with a final mean section thickness of >20 microm (h=22.3 microm +/- 0.64 microm), and with excellent rendition of Mac-1+ microglia through the entire height of the section. The NDPase staining gives an excellent visualization of microglia, although with this thickness, the intensity of the staining is too high to distinguish single cells. Lectin histochemistry does not visualize microglia throughout the section and, accordingly, is not suited for the optical fractionator. The mean total number of Mac-1+ microglial cells in the unilateral dentate gyrus of the normal young adult male C57BL/6 mouse was estimated to be 12,300 (coefficient of variation (CV)=0.13) with a mean coefficient of error (CE) of 0.06. The perspective of estimating microglial cell numbers using stereology is to establish a solid basis for studying the dynamics of the microglial cell population in the developing and in the injured, diseased and normal adult CNS.

  8. Binary tree models of high-Reynolds-number turbulence

    Science.gov (United States)

    Aurell, Erik; Dormy, Emmanuel; Frick, Peter

    1997-08-01

    We consider hierarchical models for turbulence, that are simple generalizations of the standard Gledzer-Ohkitani-Yamada shell models (E. B. Gledzer, Dokl, Akad. Nauk SSSR 209, 5 (1973) [Sov. Phys. Dokl. 18, 216 (1973)]; M. Yamada and K. Ohkitani, J. Phys. Soc. Jpn. 56, 4210 (1987)). The density of degrees of freedom is constant in wave-number space. Looking only at this behavior and at the quadratic invariants in the inviscid unforced limit, the models can be thought of as systems living naturally in one spatial dimension, but being qualitatively similar to hydrodynamics in two (2D) and three dimensions. We investigated cascade phenomena and intermittency in the different cases. We observed and studied a forward cascade of enstrophy in the 2D case.

  9. Convection in an ideal gas at high Rayleigh numbers.

    Science.gov (United States)

    Tilgner, A

    2011-08-01

    Numerical simulations of convection in a layer filled with ideal gas are presented. The control parameters are chosen such that there is a significant variation of density of the gas in going from the bottom to the top of the layer. The relations between the Rayleigh, Peclet, and Nusselt numbers depend on the density stratification. It is proposed to use a data reduction which accounts for the variable density by introducing into the scaling laws an effective density. The relevant density is the geometric mean of the maximum and minimum densities in the layer. A good fit to the data is then obtained with power laws with the same exponent as for fluids in the Boussinesq limit. Two relations connect the top and bottom boundary layers: The kinetic energy densities computed from free fall velocities are equal at the top and bottom, and the products of free fall velocities and maximum horizontal velocities are equal for both boundaries.

  10. Effects of viscoelasticity in the high Reynolds number cylinder wake

    KAUST Repository

    Richter, David

    2012-01-16

    At Re = 3900, Newtonian flow past a circular cylinder exhibits a wake and detached shear layers which have transitioned to turbulence. It is the goal of the present study to investigate the effects which viscoelasticity has on this state and to identify the mechanisms responsible for wake stabilization. It is found through numerical simulations (employing the FENE-P rheological model) that viscoelasticity greatly reduces the amount of turbulence in the wake, reverting it back to a state which qualitatively appears similar to the Newtonian mode B instability which occurs at lower Re. By focusing on the separated shear layers, it is found that viscoelasticity suppresses the formation of the Kelvin-Helmholtz instability which dominates for Newtonian flows, consistent with previous studies of viscoelastic free shear layers. Through this shear layer stabilization, the viscoelastic far wake is then subject to the same instability mechanisms which dominate for Newtonian flows, but at far lower Reynolds numbers. © Copyright Cambridge University Press 2012.

  11. Quasi-static magnetohydrodynamic turbulence at high Reynolds number

    CERN Document Server

    Favier, B F N; Cambon, C; Delache, A; Bos, W J T

    2011-01-01

    We analyse the anisotropy of homogeneous turbulence in an electrically conducting fluid submitted to a uniform magnetic field, for low magnetic Reynolds number, in the quasi- static approximation. We interpret disagreeing previous predictions between linearized theory and simulations: in the linear limit, the kinetic energy of transverse velocity components, normal to the magnetic field, decays faster than the kinetic energy of the axial component, along the magnetic field (Moffatt (1967)); whereas many numerical studies predict a final state characterised by dominant energy of transverse velocity components. We investigate the corresponding nonlinear phenomenon using Direct Numerical Simulations of freely-decaying turbulence, and a two-point statistical spectral closure based on the Eddy Damped Quasi-Normal Markovian model. The transition from the three-dimensional turbulent flow to a "two-and-a-half-dimensional" flow (Montgomery & Turner (1982)) is a result of the combined effects of short-time linear J...

  12. Numerical simulation of high Reynolds number bubble motion

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, J.B. [Clarkson Univ., Potsdam, NY (United States)

    1995-12-31

    This paper presents the results of numerical simulations of bubble motion. All the results are for single bubbles in unbounded fluids. The liquid phase is quiescent except for the motion created by the bubble, which is axisymmetric. The main focus of the paper is on bubbles that are of order 1 mm in diameter in water. Of particular interest is the effect of surfactant molecules on bubble motion. Results for the {open_quotes}insoluble surfactant{close_quotes} model will be presented. These results extend research by other investigators to finite Reynolds numbers. The results indicate that, by assuming complete coverage of the bubble surface, one obtains good agreement with experimental observations of bubble motion in tap water. The effect of surfactant concentration on the separation angle is discussed.

  13. On the Number of Galaxies at High Redshift

    Directory of Open Access Journals (Sweden)

    Lorenzo Zaninetti

    2015-09-01

    Full Text Available The number of galaxies at a given flux as a function of the redshift, z, is derived when the z-distance relation is non-standard. In order to compare different models, the same formalism is also applied to the standard cosmology. The observed luminosity function for galaxies of the zCOSMOS catalog at different redshifts is modeled by a new luminosity function for galaxies, which is derived by the truncated beta probability density function. Three astronomical tests, which are the photometric maximum as a function of the redshift for a fixed flux, the mean value of the redshift for a fixed flux, and the luminosity function for galaxies as a function of the redshift, compare the theoretical values of the standard and non-standard model with the observed value. The tests are performed on the FORS Deep Field (FDF catalog up to redshift z = 1.5 and on the zCOSMOS catalog extending beyond z = 4. These three tests show minimal differences between the standard and the non-standard models.

  14. High-resolution copy number arrays in cancer and the problem of normal genome copy number variation.

    Science.gov (United States)

    Gorringe, Kylie L; Campbell, Ian G

    2008-11-01

    High-resolution techniques for analysis of genome copy number (CN) enable the analysis of complex cancer somatic genetics. However, the analysis of these data is difficult, and failure to consider a number of issues in depth may result in false leads or unnecessary rejection of true positives. First, segmental duplications may falsely generate CN breakpoints in aneuploid samples. Second, even when tumor data were each normalized to matching lymphocyte DNA, we still observed copy number polymorphisms masquerading as somatic alterations due to allelic imbalance. We investigated a number of different solutions and determined that evaluating matching normal DNA, or at least using locally derived normal baseline data, were preferable to relying on current online databases because of poor cross-platform compatibility and the likelihood of excluding genuine small somatic alterations.

  15. Plasmoid Instability in High-Lundquist-Number Magnetic Reconnection

    CERN Document Server

    Huang, Yi-Min

    2013-01-01

    Our understanding of magnetic reconnection in resistive magnetohydrodynamics has gone through a fundamental change in recent years. The conventional wisdom is that magnetic reconnection mediated by resistivity is slow in laminar high Lundquist ($S$) plasmas, constrained by the scaling of the reconnection rate predicted by Sweet-Parker theory. However, recent studies have shown that when $S$ exceeds a critical value $\\sim10^{4}$, the Sweet-Parker current sheet is unstable to a super-Alfv\\'enic plasmoid instability, with a linear growth rate that scales as $S^{1/4}$. In the fully developed statistical steady state of two-dimensional resistive magnetohydrodynamic simulations, the normalized average reconnection rate is approximately 0.01, nearly independent of $S$, and the distribution function $f(\\psi)$ of plasmoid magnetic flux $\\psi$ follows a power law $f(\\psi)\\sim\\psi^{-1}$. When Hall effects are included, the plasmoid instability may trigger onset of Hall reconnection even when the conventional criterion f...

  16. Podocyte Number in Children and Adults: Associations with Glomerular Size and Numbers of Other Glomerular Resident Cells.

    Science.gov (United States)

    Puelles, Victor G; Douglas-Denton, Rebecca N; Cullen-McEwen, Luise A; Li, Jinhua; Hughson, Michael D; Hoy, Wendy E; Kerr, Peter G; Bertram, John F

    2015-09-01

    Increases in glomerular size occur with normal body growth and in many pathologic conditions. In this study, we determined associations between glomerular size and numbers of glomerular resident cells, with a particular focus on podocytes. Kidneys from 16 male Caucasian-Americans without overt renal disease, including 4 children (≤3 years old) to define baseline values of early life and 12 adults (≥18 years old), were collected at autopsy in Jackson, Mississippi. We used a combination of immunohistochemistry, confocal microscopy, and design-based stereology to estimate individual glomerular volume (IGV) and numbers of podocytes, nonepithelial cells (NECs; tuft cells other than podocytes), and parietal epithelial cells (PECs). Podocyte density was calculated. Data are reported as medians and interquartile ranges (IQRs). Glomeruli from children were small and contained 452 podocytes (IQR=335-502), 389 NECs (IQR=265-498), and 146 PECs (IQR=111-206). Adult glomeruli contained significantly more cells than glomeruli from children, including 558 podocytes (IQR=431-746; Pnumber of podocytes in large glomeruli does not match the increase in glomerular size observed in adults, resulting in relative podocyte depletion. This may render hypertrophic glomeruli susceptible to pathology.

  17. Barret's adenocarcinomas resemble adenocarcinomas of the gastric cardia in terms of chromosomal copy number changes, but relate to squamous cell carcinomas of the distal oesophagus with respect to the presence of high-level amplifications

    NARCIS (Netherlands)

    M.M. Weiss (Marjan); E.J. Kuipers (Ernst); M.A.J.A. Hermsen (Mario); N.C.T. Grieken (Nicole); G.J.A. Offerhaus (Johan); J.P.A. Baak (Jan); S.G.M. Meuwissen; C.J.L.M. Meijer (Chris)

    2003-01-01

    textabstractThree different cancers predominantly occur at the gastro-oesophageal junction: squamous cell carcinomas of the distal oesophagus, adenocarcinomas of the distal oesophagus (Barrett's carcinomas), and adenocarcinomas of the gastric cardia. The aim of the present study was to investigate

  18. The number of fetal nephron progenitor cells limits ureteric branching and adult nephron endowment.

    Science.gov (United States)

    Cebrian, Cristina; Asai, Naoya; D'Agati, Vivette; Costantini, Frank

    2014-04-10

    Nephrons, the functional units of the kidney, develop from progenitor cells (cap mesenchyme [CM]) surrounding the epithelial ureteric bud (UB) tips. Reciprocal signaling between UB and CM induces nephrogenesis and UB branching. Although low nephron number is implicated in hypertension and renal disease, the mechanisms that determine nephron number are obscure. To test the importance of nephron progenitor cell number, we genetically ablated 40% of these cells, asking whether this would limit kidney size and nephron number or whether compensatory mechanisms would allow the developing organ to recover. The reduction in CM cell number decreased the rate of branching, which in turn allowed the number of CM cells per UB tip to normalize, revealing a self-correction mechanism. However, the retarded UB branching impaired kidney growth, leaving a permanent nephron deficit. Thus, the number of fetal nephron progenitor cells is an important determinant of nephron endowment, largely via its effect on UB branching.

  19. An Approach to Determining the Optimal Cell Number of Manufacturing Cell Formation

    Directory of Open Access Journals (Sweden)

    Jianwei Wang

    2013-04-01

    Full Text Available An approach to determining the optimal cell number of manufacturing cell formation is presented. Firstly, the difference of weighting exponent, cluster center and metrics how to have an impact upon the clustering results and membership function are studied. Secondly, a method to determine the optimal m value is given. Two-order partial derivative of the objective function for FCM is calculated, and the variational weighting exponent m is obtained that can prevent the parameter from being the unique value and play an important role in the process of fuzzy clustering. Moreover, in order to avoid a single validity index can not assess correctly, partition coefficient (PC, classification entropy (CE, Fukuyama and Sugeno (FS and Xie and Beni (XB are considered as multi-performance indexes to evaluate the cluster validity, and then an optimal number c is chosen based on these validity measures. Finally, test exampls are given to illustrate the validity of the proposed approach.

  20. Plasmoid instability in high-Lundquist-number magnetic reconnectiona)

    Science.gov (United States)

    Huang, Yi-Min; Bhattacharjee, A.

    2013-05-01

    Our understanding of magnetic reconnection in resistive magnetohydrodynamics has gone through a fundamental change in recent years. The conventional wisdom is that magnetic reconnection mediated by resistivity is slow in laminar high Lundquist (S) plasmas, constrained by the scaling of the reconnection rate predicted by Sweet-Parker theory. However, recent studies have shown that when S exceeds a critical value ˜104, the Sweet-Parker current sheet is unstable to a super-Alfvénic plasmoid instability, with a linear growth rate that scales as S1/4. In the fully developed statistical steady state of two-dimensional resistive magnetohydrodynamic simulations, the normalized average reconnection rate is approximately 0.01, nearly independent of S, and the distribution function f(ψ) of plasmoid magnetic flux ψ follows a power law f(ψ)˜ψ-1. When Hall effects are included, the plasmoid instability may trigger onset of Hall reconnection even when the conventional criterion for onset is not satisfied. The rich variety of possible reconnection dynamics is organized in the framework of a phase diagram.

  1. Microglial numbers attain adult levels after undergoing a rapid decrease in cell number in the third postnatal week.

    Science.gov (United States)

    Nikodemova, Maria; Kimyon, Rebecca S; De, Ishani; Small, Alissa L; Collier, Lara S; Watters, Jyoti J

    2015-01-15

    During postnatal development, microglia, CNS resident innate immune cells, are essential for synaptic pruning, neuronal apoptosis and remodeling. During this period microglia undergo morphological and phenotypic transformations; however, little is known about how microglial number and density is regulated during postnatal CNS development. We found that after an initial increase during the first 14 postnatal days, microglial numbers in mouse brain began declining in the third postnatal week and were reduced by 50% by 6weeks of age; these "adult" levels were maintained until at least 9months of age. Microglial CD11b levels increased, whereas CD45 and ER-MP58 declined between P10 and adulthood, consistent with a maturing microglial phenotype. Our data indicate that both increased microglial apoptosis and a decreased proliferative capacity contribute to the developmental reduction in microglial numbers. We found no correlation between developmental reductions in microglial numbers and brain mRNA levels of Cd200, Cx3Cl1, M-Csf or Il-34. We tested the ability of M-Csf-overexpression, a key growth factor promoting microglial proliferation and survival, to prevent microglial loss in the third postnatal week. Mice overexpressing M-Csf in astrocytes had higher numbers of microglia at all ages tested. However, the developmental decline in microglial numbers still occurred, suggesting that chronically elevated M-CSF is unable to overcome the developmental decrease in microglial numbers. Whereas the identity of the factor(s) regulating microglial number and density during development remains to be determined, it is likely that microglia respond to a "maturation" signal since the reduction in microglial numbers coincides with CNS maturation.

  2. High-Resolution Analysis of Gene Copy Number Alterations in Human Prostate Cancer Using CGH on cDNA Microarrays: Impact of Copy Number on Gene Expression

    Directory of Open Access Journals (Sweden)

    Maija Wolf

    2004-05-01

    Full Text Available Identification of target genes for genetic rearrangements in prostate cancer and the impact of copy number changes on gene expression are currently not well understood. Here, we applied high-resolution comparative genomic hybridization (CGH on cDNA microarrays for analysis of prostate cancer cell lines. CGH microarrays identified most of the alterations detected by classical chromosomal CGH, as well as a number of previously unreported alterations. Specific recurrent regions of gain (28 and loss (18 were found, their boundaries defined with sub-megabasepair accuracy. The most common changes included copy number decreases at 13% and gains at iq and 5p. Refined mapping identified several sites, such as at 13q (33-44, 49-51, 74-76 Mbp from the p-telomere, which matched with minimal regions of loss seen in extensive loss of heterozygosity mapping studies of large numbers of tumors. Previously unreported recurrent changes were found at 2p, 2q, 3p, 17q (losses, at 3q, 5p, 6p (gains. Integration of genomic and transcriptomic data revealed the role of individual candidate target genes for genomic alterations as well as a highly significant (P < .0001 overall association between copy number levels and the percentage of differentially expressed genes. Across the genome, the overall impact of copy number on gene expression levels was, to a large extent, attributable to low-level gains and losses of copy number, corresponding to common deletions and gains of often large chromosomal regions.

  3. Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.

    Science.gov (United States)

    Hauswirth, Alexander W; Almeida, Julia; Nieto, Wendy G; Teodosio, Cristina; Rodriguez-Caballero, Arancha; Romero, Alfonso; López, Antonio; Fernandez-Navarro, Paulino; Vega, Tomas; Perez-Andres, Martin; Valent, Peter; Jäger, Ulrich; Orfao, Alberto

    2012-07-01

    Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.Little is known about the distribution of normal lymphoid cells and their subsets in the peripheral blood (PB) of subjects with monoclonal B-cell lymphocytosis (MBL). In our study, we compared the absolute number of PB lymphoid cells and their subpopulations in 95 MBL cases with normal lymphocyte counts vs. 617 age-/sex-matched non-MBL healthy subjects (controls), using highly sensitive flow cytometry. MBL cases showed significantly reduced numbers of normal circulating B-cells, at the expense of immature and naive B-cells; in addition, CD4+CD8+ double-positive T-cells and CD8+ T-cells were significantly lower and higher vs. controls, respectively. Moreover, most normal B-cell subsets were significantly decreased in PB at >1% MBL-counts, vs. "low-count" MBL cases, and lower amounts of immature/naive B-cells were detected in biclonal (particularly in cases with coexisting CLL-like- and non-CLL-like B-cell clones) vs. monoclonal MBL subjects. In summary, our results show imbalanced (reduced) absolute numbers of recently produced normal circulating B-cells (e.g., immature and naıve B-cells) in MBL, which becomes more pronounced as the MBL cell count increases.

  4. Mutagenic effects of a single and an exact number of alpha particles in mammalian cells

    Science.gov (United States)

    Hei, T. K.; Wu, L. J.; Liu, S. X.; Vannais, D.; Waldren, C. A.; Randers-Pehrson, G.

    1997-01-01

    One of the main uncertainties in risk estimation for environmental radon exposure using lung cancer data from underground miners is the extrapolation from high- to low-dose exposure where multiple traversal is extremely rare. The biological effects of a single alpha particle are currently unknown. Using the recently available microbeam source at the Radiological Research Accelerator Facility at Columbia University, we examined the frequencies and molecular spectrum of S1- mutants induced in human-hamster hybrid (A(L)) cells by either a single or an exact number of alpha particles. Exponentially growing cells were stained briefly with a nontoxic concentration of Hoechst dye for image analysis, and the location of individual cells was computer-monitored. The nucleus of each cell was irradiated with either 1,2,4, or 8 alpha particles at a linear energy transfer of 90 keV/microm consistent with the energy spectrum of domestic radon exposure. Although single-particle traversal was only slightly cytotoxic to A(L) cells (survival fraction approximately 0.82), it was highly mutagenic, and the induced mutant fraction averaged 110 mutants per 10(5) survivors. In addition, both toxicity and mutant induction were dose-dependent. Multiplex PCR analysis of mutant DNA showed that the proportion of mutants with multilocus deletions increased with the number of particle traversals. These data provide direct evidence that a single a particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.

  5. Lineage extrinsic and intrinsic control of immunoregulatory cell numbers by SHIP.

    Science.gov (United States)

    Collazo, Michelle M; Paraiso, Kim H T; Park, Mi-Young; Hazen, Amy L; Kerr, William G

    2012-07-01

    We previously showed that germline or induced SHIP deficiency expands immuno-regulatory cell numbers in T lymphoid and myeloid lineages. We postulated these increases could be interrelated. Here, we show that myeloid-specific ablation of SHIP leads to the expansion of both myeloid-derived suppressor cell (MDSC) and regulatory T (Treg) cell numbers, indicating SHIP-dependent control of Treg-cell numbers by a myeloid cell type. Conversely, T-lineage specific ablation of SHIP leads to expansion of Treg-cell numbers, but not expansion of the MDSC compartment, indicating SHIP also has a lineage intrinsic role in limiting Treg-cell numbers. However, the SHIP-deficient myeloid cell that promotes MDSC and Treg-cell expansion is not an MDSC as they lack SHIP protein expression. Thus, regulation of MDSC numbers in vivo must be controlled in a cell-extrinsic fashion by another myeloid cell type. We had previously shown that G-CSF levels are profoundly increased in SHIP(-/-) mice, suggesting this myelopoietic growth factor could promote MDSC expansion in a cell-extrinsic fashion. Consistent with this hypothesis, we find that G-CSF is required for expansion of the MDSC splenic compartment in mice rendered SHIP-deficient as adults. Thus, SHIP controls MDSC numbers, in part, by limiting production of the myelopoietic growth factor G-CSF.

  6. Idd13 is involved in determining immunoregulatory DN T-cell number in NOD mice.

    Science.gov (United States)

    Dugas, V; Liston, A; Hillhouse, E E; Collin, R; Chabot-Roy, G; Pelletier, A-N; Beauchamp, C; Hardy, K; Lesage, S

    2014-03-01

    Immunoregulatory T cells have been identified as key modulators of peripheral tolerance and participate in preventing autoimmune diseases. CD4(-)CD8(-) (double negative, DN) T cells compose one of these immunoregulatory T-cell subsets, where the injection of DN T cells confers protection from autoimmune diabetes progression. Interestingly, genetic loci defining the function and number of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) coincide with at least some autoimmune disease susceptibility loci. Herein, we investigate the impact of major insulin-dependent diabetes (Idd) loci in defining the number of DN T cells. We demonstrate that although Idd3, Idd5 and Idd9 loci do not regulate DN T-cell number, NOD mice congenic for diabetes resistance alleles at the Idd13 locus show a partial restoration in DN T-cell number. Moreover, competitive and non-competitive bone marrow chimera experiments reveal that DN T-cell number is defined by a bone marrow-intrinsic, but DN T-cell-extrinsic, factor. This suggests that non-autonomous candidate genes define DN T-cell number in secondary lymphoid organs. Together, our results show that the regulation of DN T-cell number in NOD mice is at least partially conferred by alleles at the Idd13 locus.

  7. Measuring Absolute RNA Copy Numbers at High Temporal Resolution Reveals Transcriptome Kinetics in Development

    Directory of Open Access Journals (Sweden)

    Nick D.L. Owens

    2016-01-01

    Full Text Available Transcript regulation is essential for cell function, and misregulation can lead to disease. Despite technologies to survey the transcriptome, we lack a comprehensive understanding of transcript kinetics, which limits quantitative biology. This is an acute challenge in embryonic development, where rapid changes in gene expression dictate cell fate decisions. By ultra-high-frequency sampling of Xenopus embryos and absolute normalization of sequence reads, we present smooth gene expression trajectories in absolute transcript numbers. During a developmental period approximating the first 8 weeks of human gestation, transcript kinetics vary by eight orders of magnitude. Ordering genes by expression dynamics, we find that “temporal synexpression” predicts common gene function. Remarkably, a single parameter, the characteristic timescale, can classify transcript kinetics globally and distinguish genes regulating development from those involved in cellular metabolism. Overall, our analysis provides unprecedented insight into the reorganization of maternal and embryonic transcripts and redefines our ability to perform quantitative biology.

  8. The Optical Fractionator Technique to Estimate Cell Numbers in a Rat Model of Electroconvulsive Therapy.

    Science.gov (United States)

    Olesen, Mikkel Vestergaard; Needham, Esther Kjær; Pakkenberg, Bente

    2017-07-09

    Stereological methods are designed to describe quantitative parameters without making assumptions about size, shape, orientation and distribution of cells or structures. These methods have been revolutionary for quantitative analysis of the mammalian brain, in which volumetric cell populations are too high to count manually, and stereology is now the technique of choice whenever estimates of three-dimensional quantities need to be extracted from measurements on two-dimensional sections. All stereological methods are in principle unbiased; however, they rely on proper knowledge about the structure of interest and the characteristics of the tissue. Stereology is based on Systematic Uniformly Random Sampling (SURS), with adjustment of sampling to the most efficient level in respect to precision, providing reliable, quantitative information about the whole structure of interest. Here we present the optical fractionator in conjunction with BrdU immunohistochemistry to estimate the production and survival of newly-formed neurons in the granule cell layer (including the sub-granular zone) of the rat hippocampus following electroconvulsive stimulation, which is among the most potent stimulators of neurogenesis. The optical fractionator technique is designed to provide estimates of the total number of cells from thick sections sampled from the full structure. Thick sections provide the opportunity to observe cells in their full 3-D extent and thus, allow for easy and robust cell classification based on morphological criteria. When correctly implemented, the sensitivity and efficiency of the optical fractionator provides accurate estimates with a fixed and predetermined precision.

  9. Effect of passage number on cellular response to DNA-damaging agents: Cell survival and gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Chang-Liu, C.M.; Woloschak, G.E. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology

    1997-08-01

    The effect of different passage numbers on plating efficiency, doubling time, cell growth, and radiation sensitivity was assessed in Syrian hamster embryo (SHE) cells. Changes in gene expression after UV or {gamma}-ray irradiation at different passage numbers were also examined. The SHE cells were maintained in culture medium for up to 64 passages. Cells were exposed to {sup 60}Co {gamma} rays or 254-nm UV radiation. Differential display of cDNAs and northern blots were used for the study of gene expression. With increasing passage number, SHE cells demonstrated decreased doubling time, increased plating efficiency, and a decreased yield in the number of cells per plate. Between passages 41 and 48 a crisis period was evident during which time cell growth in high serum was no longer optimal, and serum concentrations were reduced to maintain cell growth. Sensitivity to ionizing radiation was no different between early- and intermediate-passage cells. However, after UV exposure at low passages (passage 3), confluent cells were more sensitive to the killing effects of UV than were log-phase cells. At intermediate passages (passages 43, 48), confluent cells were slightly more radioresistant than were log-phase cells. By passage 64, however, both confluent and log-phase cells showed similar patterns of UV sensitivity. Expression of {gamma}-actin, PCNA, and p53 transcripts did not change following UV exposure. p53 mRNA was induced following {gamma}-ray exposure of the intermediate (passage 45) epithelial cells. The observed differences in radiation sensitivity associated with increasing passage number may be influenced by radiation-induced gene expression. The authors are conducted experiments to identify these genes.

  10. Optimization, Application, and Interpretation of Lactate Dehydrogenase Measurements in Microwell Determination of Cell Number and Toxicity

    NARCIS (Netherlands)

    Wolterbeek, H.T.; Van der Meer, A.J.G.M.

    2005-01-01

    The lactate dehydrogenase (LDH) assay was addressed for its sensitivity, disturbances by foaming, and cell number and size. Cells were from a U-251 MG grade IV human glioblastoma brain tumor cell line used in 100-µl well volumes. Cells were counted by microscopy and Coulter counting; assays were LDH

  11. Pten Regulates Retinal Amacrine Cell Number by Modulating Akt, Tgfβ, and Erk Signaling.

    Science.gov (United States)

    Tachibana, Nobuhiko; Cantrup, Robert; Dixit, Rajiv; Touahri, Yacine; Kaushik, Gaurav; Zinyk, Dawn; Daftarian, Narsis; Biernaskie, Jeff; McFarlane, Sarah; Schuurmans, Carol

    2016-09-07

    All tissues are genetically programmed to acquire an optimal size that is defined by total cell number and individual cellular dimensions. The retina contains stereotyped proportions of one glial and six neuronal cell types that are generated in overlapping waves. How multipotent retinal progenitors know when to switch from making one cell type to the next so that appropriate numbers of each cell type are generated is poorly understood. Pten is a phosphatase that controls progenitor cell proliferation and differentiation in several lineages. Here, using a conditional loss-of-function strategy, we found that Pten regulates retinal cell division and is required to produce the full complement of rod photoreceptors and amacrine cells in mouse. We focused on amacrine cell number control, identifying three downstream Pten effector pathways. First, phosphoinositide 3-kinase/Akt signaling is hyperactivated in Pten conditional knock-out (cKO) retinas, and misexpression of constitutively active Akt (Akt-CA) in retinal explants phenocopies the reduction in amacrine cell production observed in Pten cKOs. Second, Akt-CA activates Tgfβ signaling in retinal explants, which is a negative feedback pathway for amacrine cell production. Accordingly, Tgfβ signaling is elevated in Pten cKO retinas, and epistatic analyses placed Pten downstream of TgfβRII in amacrine cell number control. Finally, Pten regulates Raf/Mek/Erk signaling levels to promote the differentiation of all amacrine cell subtypes, which are each reduced in number in Pten cKOs. Pten is thus a positive regulator of amacrine cell production, acting via multiple downstream pathways, highlighting its diverse actions as a mediator of cell number control. Despite the importance of size for optimal organ function, how individual cell types are generated in correct proportions is poorly understood. There are several ways to control cell number, including readouts of organ function (e.g., secreted hormones reach functional

  12. Genotyping Single Nucleotide Polymorphisms and Copy Number Variability of the FCGRs Expressed on NK Cells.

    Science.gov (United States)

    Erbe, Amy K; Wang, Wei; Gallenberger, Mikayla; Hank, Jacquelyn A; Sondel, Paul M

    2016-01-01

    Natural killer (NK) cells are one of the main effector immune cells involved in antibody-dependent cell-mediated cytotoxicity (ADCC). Upon recognition of cell-bound IgG antibodies, which occurs through Fc gamma receptors (FCGRs) expressed on the cell surface of NK cells, NK cells become activated and lyse target tumor or infected cells. The FCGRs, FCGR3A and FCGR2C, expressed on the surface of NK cells have single nucleotide polymorphisms (SNPs) that result in differential activity of NK cells. In addition to SNP genetic variation within each of these genes, the FCGRs are subject to copy number variation (CNV), which leads to variable protein expression levels on the cell surface. Studies have found that FCGR genotype for FCGR3A and FCGR2C is associated with variation in the response to immunotherapy.Due to high sequence homology within FCGR3 and FCGR2 families, there are difficulties associated with genotyping these specific receptors related to cross-amplification of non-targeted FCGRs. To improve specificity for both FCGR3A and FCGR2C, Rnase-H (RH) primers were designed to amplify specifically FCGR3A (while not co-amplifying FCGR3B) and FCGR2C (while not co-amplifying FCGR2B). In addition, fluorescently labeled locked nucleic acid (LNA) probes provide additional precision for determination of the SNPs within both FCGR3A and FCGR2C. For CNV determination, separate fluorescently labeled probes for FCGR3A, and for FCGR2C, can be used with the same RH primers for each gene. These probes can be combined in the same well with control primers/probe for a known diploid gene and used to calculate the copy number of both FCGR3A and FCGR2C. Here we provide new detailed methodology that allows for the specific amplification of these FCGRs in a single PCR reaction, allowing for genotyping of both the SNPs and CNVs using real-time PCR.

  13. High Performance Perovskite Solar Cells.

    Science.gov (United States)

    Tong, Xin; Lin, Feng; Wu, Jiang; Wang, Zhiming M

    2016-05-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long-term stable all-solid-state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost-effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole-transporting materials (HTMs) and electron-transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  14. Reduced mtDNA copy number increases the sensitivity of tumor cells to chemotherapeutic drugs.

    Science.gov (United States)

    Mei, H; Sun, S; Bai, Y; Chen, Y; Chai, R; Li, H

    2015-04-02

    Many cancer drugs are toxic to cells by activating apoptotic pathways. Previous studies have shown that mitochondria have key roles in apoptosis in mammalian cells, but the role of mitochondrial DNA (mtDNA) copy number variation in the pathogenesis of tumor cell apoptosis remains largely unknown. We used the HEp-2, HNE2, and A549 tumor cell lines to explore the relationship between mtDNA copy number variation and cell apoptosis. We first induced apoptosis in three tumor cell lines and one normal adult human skin fibroblast cell line (HSF) with cisplatin (DDP) or doxorubicin (DOX) treatment and found that the mtDNA copy number significantly increased in apoptotic tumor cells, but not in HSF cells. We then downregulated the mtDNA copy number by transfection with shRNA-TFAM plasmids or treatment with ethidium bromide and found that the sensitivity of tumor cells to DDP or DOX was significantly increased. Furthermore, we observed that levels of reactive oxygen species (ROS) increased significantly in tumor cells with lower mtDNA copy numbers, and this might be related to a low level of antioxidant gene expression. Finally, we rescued the increase of ROS in tumor cells with lipoic acid or N-acetyl-L-cysteine and found that the apoptosis rate decreased. Our studies suggest that the increase of mtDNA copy number is a self-protective mechanism of tumor cells to prevent apoptosis and that reduced mtDNA copy number increases ROS levels in tumor cells, increases the tumor cells' sensitivity to chemotherapeutic drugs, and increases the rate of apoptosis. This research provides evidence that mtDNA copy number variation might be a promising new therapeutic target for the clinical treatment of tumors.

  15. Reduced mtDNA copy number increases the sensitivity of tumor cells to chemotherapeutic drugs

    Science.gov (United States)

    Mei, H; Sun, S; Bai, Y; Chen, Y; Chai, R; Li, H

    2015-01-01

    Many cancer drugs are toxic to cells by activating apoptotic pathways. Previous studies have shown that mitochondria have key roles in apoptosis in mammalian cells, but the role of mitochondrial DNA (mtDNA) copy number variation in the pathogenesis of tumor cell apoptosis remains largely unknown. We used the HEp-2, HNE2, and A549 tumor cell lines to explore the relationship between mtDNA copy number variation and cell apoptosis. We first induced apoptosis in three tumor cell lines and one normal adult human skin fibroblast cell line (HSF) with cisplatin (DDP) or doxorubicin (DOX) treatment and found that the mtDNA copy number significantly increased in apoptotic tumor cells, but not in HSF cells. We then downregulated the mtDNA copy number by transfection with shRNA-TFAM plasmids or treatment with ethidium bromide and found that the sensitivity of tumor cells to DDP or DOX was significantly increased. Furthermore, we observed that levels of reactive oxygen species (ROS) increased significantly in tumor cells with lower mtDNA copy numbers, and this might be related to a low level of antioxidant gene expression. Finally, we rescued the increase of ROS in tumor cells with lipoic acid or N-acetyl-L-cysteine and found that the apoptosis rate decreased. Our studies suggest that the increase of mtDNA copy number is a self-protective mechanism of tumor cells to prevent apoptosis and that reduced mtDNA copy number increases ROS levels in tumor cells, increases the tumor cells' sensitivity to chemotherapeutic drugs, and increases the rate of apoptosis. This research provides evidence that mtDNA copy number variation might be a promising new therapeutic target for the clinical treatment of tumors. PMID:25837486

  16. Reduced iNKT cells numbers in type 1 diabetes patients and their first-degree relatives.

    Science.gov (United States)

    Beristain-Covarrubias, Nonantzin; Canche-Pool, Elsy; Gomez-Diaz, Rita; Sanchez-Torres, Luvia E; Ortiz-Navarrete, Vianney

    2015-12-01

    Type 1 diabetes (T1D) is an autoimmune disease that is characterized by the specific destruction of insulin-producing pancreatic β cells. Invariant natural killer T (iNKT) cells have been associated with development of T1D. Class I MHC-restricted T cell-associated molecule (CRTAM) is expressed on activated iNKT, CD8(+), and CD4(+) T cells, and it is associated with the pro-inflammatory profiles of these cells. Crtam gene expression in CD3(+) lymphocytes from non-obese diabetic (NOD) mice is associated with T1D onset. However, expression of CRTAM on T cells from patients with T1D has not yet been evaluated. We compared iNKT cell (CD3(+)Vα24(+)Vβ11(+)) numbers and CRTAM expression in a Mexican population with recent-onset T1D and their first-degree relatives with control families. Remarkably, we found lower iNKT cell numbers in T1D families, and we identified two iNKT cell populations in some of the families. One iNKT cell population expressed high iTCR levels (iNKT(hi)), whereas another expressed low levels (iNKT(lo)) and also expressed CRTAM. These findings support a probable genetic determinant of iNKT cell numbers and a possible role for these cells in T1D development. This study also suggests that CRTAM identifies recently activated iNKT lymphocytes.

  17. Estimation of the total number of mast cells in the human umbilical cord. A methodological study

    DEFF Research Database (Denmark)

    Engberg Damsgaard, T M; Windelborg Nielsen, B; Sørensen, Flemming Brandt

    1992-01-01

    The aim of the present study was to estimate the total number of mast cells in the human umbilical cord. Using 50 microns-thick paraffin sections, made from a systematic random sample of umbilical cord, the total number of mast cells per cord was estimated using a combination of the optical...... disector and fractionated sampling. The mast cell of the human umbilical cord was found in Wharton's jelly, most frequently in close proximity to the three blood vessels. No consistent pattern of variation in mast cell numbers from the fetal end of the umbilical cord towards the placenta was seen....... The total number of mast cells found in the umbilical cord was 5,200,000 (median), range 2,800,000-16,800,000 (n = 7), that is 156,000 mast cells per gram umbilical cord (median), range 48,000-267,000. Thus, the umbilical cord constitutes an adequate source of mast cells for further investigation...

  18. Opposing Shear-Induced Forces Dominate Inertial Focusing in Curved Channels and High Reynolds Numbers

    CERN Document Server

    Keinan, Eliezer; Nahmias, Yaakov

    2015-01-01

    Inertial focusing is the migration of particles in fluid toward equilibrium, where current theory predicts that shear-induced and wall-induced lift forces are balanced. First reported in 1961, this Segre-Silberberg effect is particularly useful for microfluidic isolation of cells and particles. Interestingly, recent work demonstrated particle focusing at high Reynolds numbers that cannot be explained by current theory. In this work, we show that non-monotonous velocity profiles, such as those developed in curved channels, create peripheral velocity maxima around which opposing shear-induced forces dominate over wall effects. Similarly, entry effects amplified in high Reynolds flow produce an equivalent trapping mechanism in short, straight channels. This new focusing mechanism in the developing flow regime enables a 10-fold miniaturization of inertial focusing devices, while our model corrects long-standing misconceptions about the nature of mechanical forces governing inertial focusing in curved channels.

  19. Experimental Investigation of Turbulence-Chemistry Interaction in High-Reynolds-Number Turbulent Partially Premixed Flames

    Science.gov (United States)

    2016-06-23

    AFRL-AFOSR-VA-TR-2016-0277 Experimental Investigation of Turbulence- Chemistry Interaction in High-Reynolds-Number Turbulent Partially Premixed...4. TITLE AND SUBTITLE [U] Experimental investigation of turbulence- chemistry interaction in high-Reynolds-number 5a. CONTRACT NUMBER turbulent...flames. Mixture fraction is an important variable in understanding and modeling turbulent mixing and turbulence- chemistry interaction, two key

  20. Assessment of satellite cell number and activity status in human skeletal muscle biopsies

    DEFF Research Database (Denmark)

    Mackey, Abigail; Kjaer, Michael; Charifi, Nadia;

    2009-01-01

    The primary aim of our study was to validate the assessment of myonuclear and satellite cell number in biopsies from human skeletal muscle. We found that 25 type I and 25 type II fibers are sufficient to estimate the mean number of myonuclei per fiber. In contrast, the assessment of satellite cells...

  1. Experimental investigation of acoustic streaming in a cylindrical wave guide up to high streaming Reynolds numbers.

    Science.gov (United States)

    Reyt, Ida; Bailliet, Hélène; Valière, Jean-Christophe

    2014-01-01

    Measurements of streaming velocity are performed by means of Laser Doppler Velocimetry and Particle Image Velociimetry in an experimental apparatus consisting of a cylindrical waveguide having one loudspeaker at each end for high intensity sound levels. The case of high nonlinear Reynolds number ReNL is particularly investigated. The variation of axial streaming velocity with respect to the axial and to the transverse coordinates are compared to available Rayleigh streaming theory. As expected, the measured streaming velocity agrees well with the Rayleigh streaming theory for small ReNL but deviates significantly from such predictions for high ReNL. When the nonlinear Reynolds number is increased, the outer centerline axial streaming velocity gets distorted towards the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes. This kind of behavior is followed by outer streaming cells only and measurements in the near wall region show that inner streaming vortices are less affected by this substantial evolution of fast streaming pattern. Measurements of the transient evolution of streaming velocity provide an additional insight into the evolution of fast streaming.

  2. Parallel WGA and WTA for Comparative Genome and Transcriptome NGS Analysis Using Tiny Cell Numbers.

    Science.gov (United States)

    Korfhage, Christian; Fricke, Evelyn; Meier, Andreas

    2015-07-01

    Genomic DNA determines how and when the transcriptome is changed by a trigger or environmental change and how cellular metabolism is influenced. Comparative genome and transcriptome analysis of the same cell sample links a defined genome with all changes in the bases, structure, or numbers of the transcriptome. However, comparative genome and transcriptome analysis using next-generation sequencing (NGS) or real-time PCR is often limited by the small amount of sample available. In mammals, the amount of DNA and RNA in a single cell is ∼10 picograms, but deep analysis of the genome and transcriptome currently requires several hundred nanograms of nucleic acids for library preparation for NGS sequencing. Consequently, accurate whole-genome amplification (WGA) and whole-transcriptome amplification (WTA) is required for such quantitative analysis. This unit describes how the genome and the transcriptome of a tiny number of cells can be amplified in a highly parallel and comparable process. Protocols for quality control of amplified DNA and application of amplified DNA for NGS are included.

  3. Revised Estimates for the Number of Human and Bacteria Cells in the Body.

    Science.gov (United States)

    Sender, Ron; Fuchs, Shai; Milo, Ron

    2016-08-01

    Reported values in the literature on the number of cells in the body differ by orders of magnitude and are very seldom supported by any measurements or calculations. Here, we integrate the most up-to-date information on the number of human and bacterial cells in the body. We estimate the total number of bacteria in the 70 kg "reference man" to be 3.8·1013. For human cells, we identify the dominant role of the hematopoietic lineage to the total count (≈90%) and revise past estimates to 3.0·1013 human cells. Our analysis also updates the widely-cited 10:1 ratio, showing that the number of bacteria in the body is actually of the same order as the number of human cells, and their total mass is about 0.2 kg.

  4. T-cell number and subtype influence the disease course of primary chronic lymphocytic leukaemia xenografts in alymphoid mice

    Directory of Open Access Journals (Sweden)

    Ceri E. Oldreive

    2015-11-01

    Full Text Available Chronic lymphocytic leukaemia (CLL cells require microenvironmental support for their proliferation. This can be recapitulated in highly immunocompromised hosts in the presence of T cells and other supporting cells. Current primary CLL xenograft models suffer from limited duration of tumour cell engraftment coupled with gradual T-cell outgrowth. Thus, a greater understanding of the interaction between CLL and T cells could improve their utility. In this study, using two distinct mouse xenograft models, we investigated whether xenografts recapitulate CLL biology, including natural environmental interactions with B-cell receptors and T cells, and whether manipulation of autologous T cells can expand the duration of CLL engraftment. We observed that primary CLL xenografts recapitulated both the tumour phenotype and T-cell repertoire observed in patients and that engraftment was significantly shorter for progressive tumours. A reduction in the number of patient T cells that were injected into the mice to 2-5% of the initial number or specific depletion of CD8+ cells extended the limited xenograft duration of progressive cases to that characteristic of indolent disease. We conclude that manipulation of T cells can enhance current CLL xenograft models and thus expand their utility for investigation of tumour biology and pre-clinical drug assessment.

  5. Prediction and control of number of cells in microdroplets by stochastic modeling

    OpenAIRE

    Ceyhan, Elvan; Xu, Feng; Gürkan, Umut Atakan; Emre, Almet Emrehan; Turalı, Emine Sümeyra; El Assal, Rami; Açıkgenc, Ali; Wu, Chung-an Max; Demirci, Utkan

    2012-01-01

    Manipulation and encapsulation of cells in microdroplets has found many applications in various fields such as clinical diagnostics, pharmaceutical research, and regenerative medicine. The control over the number of cells in individual droplets is important especially for microfluidic and bioprinting applications. There is a growing need for modeling approaches that enable control over a number of cells within individual droplets. In this study, we developed statistical models based on negati...

  6. Passage number affects the pluripotency of mouse embryonic stem cells as judged by tetraploid embryo aggregation.

    Science.gov (United States)

    Li, Xiang-Yun; Jia, Qing; Di, Ke-Qian; Gao, Shu-Min; Wen, Xiao-Hui; Zhou, Rong-Yan; Wei, Wei; Wang, Li-Ze

    2007-03-01

    The aim of this study was to determine whether the number of passages affected the developmental pluripotency of embryonic stem (ES) cells as measured by the attainment of adult fertile mice derived from embryonic stem (ES) cell/tetraploid embryo complementation. Thirty-six newborns were produced by the aggregation of tetraploid embryos and hybrid ES cells after various numbers of passages. These newborns were entirely derived from ES cells as judged by microsatellite DNA, coat-color phenotype, and germline transmission. Although 15 survived to adulthood, 17 died of respiratory failure, and four were eaten by their foster mother. From the 15 mice that reached adulthood and that could reproduce, none arose from ES cells at passage level 15 or more. All 15 arose from cells at passages 3-11. Our results demonstrate that the number of passages affects the developmental pluripotency of ES cells.

  7. Changes in ocular mast cell numbers and histamine distribution during experimental autoimmune uveitis.

    Science.gov (United States)

    Lee, C H; Lang, L S; Orr, E L

    1993-01-01

    Choroidal mast cells have been implicated in experimental autoimmune uveitis (EAU), an ocular inflammatory disease induced by S-antigen. Our data confirm that choroidal mast cell numbers decrease with clinical onset of S-antigen-induced EAU in Lewis rats, and establish that the decrease is statistically significant. In addition, we find that the numbers of limbal mast cells also decrease during S-antigen-induced EAU, and that this decrease occurs earlier in the course of the disease than that observed for choroidal mast cells. Activation and degranulation of mast cells, as evidenced by decreases in mast cell number, result in the synthesis and/or release of large quantities of mast cell mediators, such as histamine. Histamine levels in EAU were found to change significantly, decreasing in the anterior portion of the eye and increasing in the choroid and retina, in concert with changes in mast cell number over the course of EAU. Mast cell mediators may actively contribute to the pathogenesis of EAU through direct enhancement of the inflammation, by stimulation of other elements of the immune system, and/or through facilitation of the blood-retinal barrier breakdown that occurs in EAU. Overall, these results add to the evidence for a mast cell role in EAU, and, in addition, show that the mast cell involvement in EAU includes the mast cells of the limbus.

  8. Numerical analyses of high Reynolds number flow of high pressure fuel gas through rough pipes

    Energy Technology Data Exchange (ETDEWEB)

    Cadorin, Margherita; Morini, Mirko; Pinelli, Michele [ENDIF - Engineering Department in Ferrara, University of Ferrara, Via Saragat, 1 - 44122 Ferrara (Italy)

    2010-07-15

    In this paper, a CFD commercial code is used to evaluate the pressure drop through pipes in a stream of high pressure gas. Both hexahedral and tetrahedral grids are considered. Preliminarily, a grid sensitivity analysis is carried out by comparing CFD results with analytical results. Each grid is characterized by a different number and thickness of layers in order to investigate the behavior of the grid with respect to the boundary layer. Then, the model is validated by using a literature test case, in which high pressure gas flow through a rough pipe is experimentally studied. Moreover, various equations of state (i.e., constant properties, Ideal Gas and Redlich-Kwong equations) and boundary conditions (e.g., pressure, mass flow, etc.) are taken into consideration and compared. Finally, the model is used to extrapolate the behavior of gaseous fuels (i.e., natural gas, biogas and hydrogen-methane mixture) flowing at high pressure through pipes of different roughness. The analyses show that the radial depth of the prism layers on pipe wall has to be controlled to allow the correct resolution of the boundary layer. Moreover, the results highlight that the first element height of the prism layer should be high enough to avoid inconsistencies in the rough model application. At the same time, the grid used for calculations does not strongly influence the numerical results and hence tune of the first element height to perfectly fit the roughness is not always justified. The final analysis on the different gaseous fuels put into evidence the capability of the CFD analysis to determine the energy performance of fuel transportation in gas pipeline. (author)

  9. Gene expression analysis on small numbers of invasive cells collected by chemotaxis from primary mammary tumors of the mouse

    Directory of Open Access Journals (Sweden)

    Segall Jeffrey E

    2003-08-01

    Full Text Available Abstract Background cDNA microarrays have the potential to identify the genes involved in invasion and metastasis. However, when used with whole tumor tissue, the results average the expression patterns of different cell types. We have combined chemotaxis-based cell collection of the invasive subpopulation of cells within the primary tumor with array-based gene expression analysis to identify the genes necessary for the process of carcinoma cell invasion. Results Invasive cells were collected from live primary tumors using microneedles containing chemotactic growth factors to mimic chemotactic signals thought to be present in the primary tumor. When used with mammary tumors of rats and mice, carcinoma cells and macrophages constitute the invasive cell population. Microbeads conjugated with monoclonal anti-CD11b (Mac-1α antibodies were used to separate macrophages from carcinoma cells. We utilized PCR-based cDNA amplification from small number of cells and compared it to the quality and complexity of conventionally generated cDNA to determine if amplified cDNA could be used with fidelity for array analysis of this cell population. These techniques showed a very high level of correlation indicating that the PCR based amplification technique yields a cDNA population that resembles, with high fidelity, the original template population present in the small number of cells used to prepare the cDNA for use with the chip. Conclusions The specific collection of invasive cells from a primary tumor and the analysis of gene expression in these cells are is now possible. By further comparing the gene expression patterns of cells collected by invasion into microneedles with that of carcinoma cells obtained from the whole primary tumor, the blood, and whole metastatic tumors, genes that contribute to the invasive process in carcinoma cells may be identified.

  10. Three counting methods agree on cell and neuron number in chimpanzee primary visual cortex

    Directory of Open Access Journals (Sweden)

    Daniel James Miller

    2014-05-01

    Full Text Available Determining the cellular composition of specific brain regions is crucial to our understanding of the function of neurobiological systems. It is therefore useful to identify the extent to which different methods agree when estimating the same properties of brain circuitry. In this study, we estimated the number of neuronal and non-neuronal cells in the primary visual cortex (area 17 or V1 of both hemispheres from a single chimpanzee. Specifically, we processed samples distributed across V1 of the right hemisphere after cortex was flattened into a sheet using two variations of the isotropic fractionator cell and neuron counting method. We processed the left hemisphere as serial brain slices for stereological investigation. The goal of this study was to evaluate the agreement between these methods in the most direct manner possible by comparing estimates of cell density across one brain region of interest in a single individual. In our hands, these methods produced similar estimates of the total cellular population (approximately 1 billion as well as the number of neurons (approximately 675 million in chimpanzee V1, providing evidence that both techniques estimate the same parameters of interest. In addition, our results indicate the strengths of each distinct tissue preparation procedure, highlighting the importance of attention to anatomical detail. In summary, we found that the isotropic fractionator and the stereological optical fractionator produced concordant estimates of the cellular composition of V1, and that this result supports the conclusion that chimpanzees conform to the primate pattern of exceptionally high packing density in V1. Ultimately, our data suggest that investigators can optimize their experimental approach by using any of these counting methods to obtain reliable cell and neuron counts.

  11. Abnormal number cell division of human thyroid anaplastic carcinoma cell line, SW 1736

    Directory of Open Access Journals (Sweden)

    Keiichi Ikeda

    2015-12-01

    Full Text Available Cell division, during which a mother cell usually divides into two daughter cells during one cell cycle, is the most important physiological event of cell biology. We observed one-to-four cell division during imaging of live SW1736 human thyroid anaplastic carcinoma cells transfected with a plasmid expressing the hybrid protein of green fluorescent protein and histone 2B (plasmid eGFP-H2B. Analysis of the images revealed a mother cell divided into four daughter cells. And one of the abnormally divided daughter cells subsequently formed a dinucleate cell.

  12. Relationship between the number of cells surrounding oocytes and energy states of oocytes.

    Science.gov (United States)

    Munakata, Yasuhisa; Ichinose, Tomoya; Ogawa, Kaori; Itami, Nobuhiko; Tasaki, Hidetaka; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

    2016-10-15

    Lipid content, ATP content, and histone acetylation are thought to reflect the energy state of cells. In addition, the energy state closely associates with growth and developmental ability of oocytes. Oocyte growth is accompanied by active proliferation of the surrounding granulosa cells (GCs), and GCs play a key role in the provision of energy substrates to the oocytes. In the present study, we first examined the relationship among the average number of GCs per follicle, the average number of cumulus cells (CCs) per oocyte, and the average lipid content in oocytes that developed in vivo within individual donor gilts. Second, we validated the relationship between the number of cells surrounding oocytes and the energy states of oocytes by using an IVC system of oocyte granulosa cell complexes (OGCs) derived from early antral follicles. We collected cumulus cells and oocyte complexes (COCs) from antral follicles (3-5 mm in diameter) and found that average lipid content in oocytes significantly correlated with the average number of both GCs/follicle and CCs/oocyte (P cell number of OGCs, as well as the lipid content, ATP content, and acetylation level of H4K12 in oocytes grown in vitro. In addition, glucose consumption by OGCs was calculated from the sample media collected at Days 13 and 14. The lipid content of oocytes grown in vitro, significantly correlated with the number of cells surrounding the oocytes (P number of cells surrounding the oocytes (P number of cells surrounding the oocytes, and glucose uptake by OGCs is crucial for lipid content and ATP content, and H4K12 acetylation in oocytes.

  13. Effect of passage number on electrophoretic mobility distributions of cultured human embryonic kidney cells

    Science.gov (United States)

    Kunze, M. E.

    1985-01-01

    A systematic investigation was undertaken to characterize population shifts that occur in cultured human embryonic kidney cells as a function of passage number in vitro after original explantation. This approach to cell population shift analysis follows the suggestion of Mehreshi, Klein and Revesz that perturbed cell populations can be characterized by electrophoretic mobility distributions if they contain subpopulations with different electrophoretic mobilities. It was shown that this is the case with early passage cultured human embryo cells.

  14. Particle size- and number-dependent delivery to cells by layered double hydroxide nanoparticles.

    Science.gov (United States)

    Dong, Haiyan; Parekh, Harendra S; Xu, Zhi Ping

    2015-01-01

    It is well known that delivery efficiency to cells is highly dependent on particle size and the administered dose. However, there is a marked discrepancy in many reports, mainly due to the inconsistency in assessment of various parameters. In this particular research, we designed experiments using layered double hydroxide nanoparticles (LDH NPs) to specifically elucidate the effect of particle size, dose and dye loading manner on cellular uptake. Using the number of LDH NPs taken up by HCT-116 cells as the indicator of delivery efficiency, we found that (1) the size of sheet-like LDH in the range of 40-100 nm did not significantly affect their cellular uptake; (2) cellular uptake of 40 and 100 nm LDH NPs was increased proportionally to the number concentration below a critical value, but remained relatively constant beyond the critical value; and (3) the effect of the dye loading manner is mainly dependent on the loading capacity or yield. In particular, the loading capacity is determined by the NP specific surface area. This research may be extended to a larger size range to examine the size effect, but suggests that it is necessary to set up a protocol to evaluate the effects of NP's physicochemical properties on the cellular delivery efficiency.

  15. Shot number estimation for EB direct writing for logic LSI utilizing character-build standard-cell layout technique

    Science.gov (United States)

    Kajiya, Yoshihiko; Nakamura, Akihiro; Yoshikawa, Masaya; Fujino, Takeshi

    2006-05-01

    Electron Beam direct writing (EBDW) technology is the most cost-effective lithography tool for small-volume logic-LSI fabrication. The EB exposure time will be greatly reduced by applying character-projection (CP) aperture. But the applicable number of CP aperture is limited to 25-400 depending upon EB lithography apparatus. The cell-based logic LSIs are composed of standard-cells (SCs) whose number is 400-1000. Therefore, it is impossible to implement all SCs as CP apertures, because the SCs are placed to 4-directions in general. We had proposed the new technique named 'Character-Build (CB) standard-cell', and demonstrate the most of the combination-logic SCs can be composed by only 17 CP apertures. In this paper, not only combination-logic SCs but also sequential-logic SCs are considered. The number of EB-shots and the chip-area are estimated for some sample circuits. Compared to the simply-limited SCs, The EB shot number is 30-40% reduced by using proposed CB standard-cell, when the CP aperture numbers are 20-30. Moreover, CB standard-cell was advantageous in the module area. Considering 2-directional placement of SCs, the combination of the EB apparatus with 50-100 CP apertures and the CB standard-cell technique may be the best method for high-speed EB direct-writing.

  16. Reduced numbers of Sertoli, germ, and spermatogonial stem cells in impaired spermatogenesis.

    Science.gov (United States)

    Hentrich, Anna; Wolter, Martin; Szardening-Kirchner, Carolin; Lüers, Georg H; Bergmann, Martin; Kliesch, Sabine; Konrad, Lutz

    2011-10-01

    A key step in the investigation of male infertility is the appropriate classification of impaired spermatogenesis. In this study, we precisely identified Sertoli and distinct germ-cell types in the rat, the mouse, and in the human testis. As a proof of principle, we studied testis biopsy samples from azoospermic patients with defined spermatogenic defects. Remarkably, we found that already the numbers of Sertoli cells, spermatogonia and a subset of spermatogonia including stem cells are significantly reduced in patients with maturation arrest at the level of primary spermatocytes (n=33) compared with patients with histologically normal spermatogenesis (n=33). In patients with hypospermatogenesis (n=44) a significant reduction of spermatogonial cell numbers was observed. The numbers of primary and diplotene spermatocytes were reduced by 84%. However, the strongest reduction (96%) was revealed in the numbers of spermatids in patients with maturation arrest. In contrast, patients with hypospermatogenesis showed only modestly reduced numbers of spermatocytes and spermatids compared with normal spermatogenesis. No correlation was found with age or obstruction. For a detailed analysis of the patients, we distinguished between 'pool of founder cells'-related deficiencies (reduced numbers of Sertoli cells, spermatogonia, and spermatogonial stem cells) and 'meiotic' deficiencies (reduced numbers of spermatocytes, meiotic divisions, and spermatids). Interestingly, patients with maturation arrest showed meiotic deficiencies (36%), while the majority additionally demonstrated deficiencies in the founder pool (58%). In contrast, patients with normal spermatogenesis most often had no deficiencies at all (45%) or founder pool-related deficiencies (33%) but an apparently normal meiosis. This is the first report showing that many infertile patients face besides meiotic defects the problem of reduced numbers of Sertoli cells, spermatogonia, and spermatogonial stem cells.

  17. Proteomic changes resulting from gene copy number variations in cancer cells.

    Directory of Open Access Journals (Sweden)

    Tamar Geiger

    2010-09-01

    Full Text Available Along the transformation process, cells accumulate DNA aberrations, including mutations, translocations, amplifications, and deletions. Despite numerous studies, the overall effects of amplifications and deletions on the end point of gene expression--the level of proteins--is generally unknown. Here we use large-scale and high-resolution proteomics combined with gene copy number analysis to investigate in a global manner to what extent these genomic changes have a proteomic output and therefore the ability to affect cellular transformation. We accurately measure expression levels of 6,735 proteins and directly compare them to the gene copy number. We find that the average effect of these alterations on the protein expression is only a few percent. Nevertheless, by using a novel algorithm, we find the combined impact that many of these regional chromosomal aberrations have at the protein level. We show that proteins encoded by amplified oncogenes are often overexpressed, while adjacent amplified genes, which presumably do not promote growth and survival, are attenuated. Furthermore, regulation of biological processes and molecular complexes is independent of general copy number changes. By connecting the primary genome alteration to their proteomic consequences, this approach helps to interpret the data from large-scale cancer genomics efforts.

  18. Particle-in-cell simulations of particle energization from low Mach number fast mode shocks

    CERN Document Server

    Park, Jaehong; Blackman, Eric G; Ren, Chuang; Siller, Robert

    2012-01-01

    Astrophysical shocks are often studied in the high Mach number limit but weakly compressive fast shocks can occur in magnetic reconnection outflows and are considered to be a site of particle energization in solar flares. Here we study the microphysics of such perpendicular, low Mach number collisionless shocks using two-dimensional particle-in-cell (PIC) simulations with a reduced ion/electron mass ratio and employ a moving wall boundary method for initial generation of the shock. This moving wall method allows for more control of the shock speed, smaller simulation box sizes, and longer simulation times than the commonly used fixed wall, reflection method of shock formation. Our results, which are independent of the shock formation method, reveal the prevalence shock drift acceleration (SDA) of both electron and ions in a purely perpendicular shock with Alfv\\'en Mach number $M_A=6.8$ and ratio of thermal to magnetic pressure $\\beta=8$. We determine the respective minimum energies required for electrons and ...

  19. The number of fetal cells in maternal blood is associated to exercise and fetal gender

    DEFF Research Database (Denmark)

    Schlütter, Jacob Mørup; Kirkegaard, Ida; Christensen, Connie Britta;

    were then stained with a cocktail of fetal cell-specific antibodies, identified and counted. Results: Participants carrying male fetuses had higher median number of fcmbs per 30 mL blood than those carrying female fetuses (5 vs. 3, p=0.004). Exercise within 3 hours (1.5 vs. 4, p=0.02) and 24 hours (2......Introduction: We have established a robust method to specifically identify and isolate a placental fetal cell in maternal blood (fcmbs) at a gestational age of 12 weeks. The concentration of these cells, however, varies considerably among pregnant women (median 3 fcmbs/30 mL blood, range 0...... activity was obtained by a questionnaire and a structured interview. The number of fcmbs was assessed in 30 mL blood processed by a proprietary method developed in-house. Fetal cells in the blood, binding to fetal cell specific antibodies, were initially isolated by magnetic cell sorting. The fetal cells...

  20. miR-129-3p controls centrosome number in metastatic prostate cancer cells by repressing CP110.

    Science.gov (United States)

    Bijnsdorp, Irene V; Hodzic, Jasmina; Lagerweij, Tonny; Westerman, Bart; Krijgsman, Oscar; Broeke, Jurjen; Verweij, Frederik; Nilsson, R Jonas A; Rozendaal, Lawrence; van Beusechem, Victor W; van Moorselaar, Jeroen A; Wurdinger, Thomas; Geldof, Albert A

    2016-03-29

    The centrosome plays a key role in cancer invasion and metastasis. However, it is unclear how abnormal centrosome numbers are regulated when prostate cancer (PCa) cells become metastatic. CP110 was previously described for its contribution of centrosome amplification (CA) and early development of aggressive cell behaviour. However its regulation in metastatic cells remains unclear. Here we identified miR-129-3p as a novel metastatic microRNA. CP110 was identified as its target protein. In PCa cells that have metastatic capacity, CP110 expression was repressed by miR-129-3p. High miR-129-3p expression levels increased cell invasion, while increasing CP110 levels decreased cell invasion. Overexpression of CP110 in metastatic PCa cells resulted in a decrease in the number of metastasis. In tissues of PCa patients, low CP110 and high miR-129-3p expression levels correlated with metastasis, but not with the expression of genes related to EMT. Furthermore, overexpression of CP110 in metastatic PCa cells resulted in excessive-CA (E-CA), and a change in F-actin distribution which is in agreement with their reduced metastatic capacity. Our data demonstrate that miR-129-3p functions as a CA gatekeeper in metastatic PCa cells by maintaining pro-metastatic centrosome amplification (CA) and preventing anti-metastatic E-CA.

  1. Physical skill training increases the number of surviving new cells in the adult hippocampus.

    Directory of Open Access Journals (Sweden)

    Daniel M Curlik

    Full Text Available The dentate gyrus is a major site of plasticity in the adult brain, giving rise to thousands of new neurons every day, through the process of adult neurogenesis. Although the majority of these cells die within two weeks of their birth, they can be rescued from death by various forms of learning. Successful acquisition of select types of associative and spatial memories increases the number of these cells that survive. Here, we investigated the possibility that an entirely different form of learning, physical skill learning, could rescue new hippocampal cells from death. To test this possibility, rats were trained with a physically-demanding and technically-difficult version of a rotarod procedure. Acquisition of the physical skill greatly increased the number of new hippocampal cells that survived. The number of surviving cells positively correlated with performance on the task. Only animals that successfully mastered the task retained the cells that would have otherwise died. Animals that failed to learn, and those that did not learn well did not retain any more cells than those that were untrained. Importantly, acute voluntary exercise in activity wheels did not increase the number of surviving cells. These data suggest that acquisition of a physical skill can increase the number of surviving hippocampal cells. Moreover, learning an easier version of the task did not increase cell survival. These results are consistent with previous reports revealing that learning only rescues new neurons from death when acquisition is sufficiently difficult to achieve. Finally, complete hippocampal lesions did not disrupt acquisition of this physical skill. Therefore, physical skill training that does not depend on the hippocampus can effectively increase the number of surviving cells in the adult hippocampus, the vast majority of which become mature neurons.

  2. Physical skill training increases the number of surviving new cells in the adult hippocampus.

    Science.gov (United States)

    Curlik, Daniel M; Maeng, Lisa Y; Agarwal, Prateek R; Shors, Tracey J

    2013-01-01

    The dentate gyrus is a major site of plasticity in the adult brain, giving rise to thousands of new neurons every day, through the process of adult neurogenesis. Although the majority of these cells die within two weeks of their birth, they can be rescued from death by various forms of learning. Successful acquisition of select types of associative and spatial memories increases the number of these cells that survive. Here, we investigated the possibility that an entirely different form of learning, physical skill learning, could rescue new hippocampal cells from death. To test this possibility, rats were trained with a physically-demanding and technically-difficult version of a rotarod procedure. Acquisition of the physical skill greatly increased the number of new hippocampal cells that survived. The number of surviving cells positively correlated with performance on the task. Only animals that successfully mastered the task retained the cells that would have otherwise died. Animals that failed to learn, and those that did not learn well did not retain any more cells than those that were untrained. Importantly, acute voluntary exercise in activity wheels did not increase the number of surviving cells. These data suggest that acquisition of a physical skill can increase the number of surviving hippocampal cells. Moreover, learning an easier version of the task did not increase cell survival. These results are consistent with previous reports revealing that learning only rescues new neurons from death when acquisition is sufficiently difficult to achieve. Finally, complete hippocampal lesions did not disrupt acquisition of this physical skill. Therefore, physical skill training that does not depend on the hippocampus can effectively increase the number of surviving cells in the adult hippocampus, the vast majority of which become mature neurons.

  3. Helicobacter pylori strains vary cell shape and flagellum number to maintain robust motility in viscous environments.

    Science.gov (United States)

    Martínez, Laura E; Hardcastle, Joseph M; Wang, Jeffrey; Pincus, Zachary; Tsang, Jennifer; Hoover, Timothy R; Bansil, Rama; Salama, Nina R

    2016-01-01

    The helical shape of the human stomach pathogen Helicobacter pylori has been suggested to provide mechanical advantage for penetrating the viscous stomach mucus layer. Using single-cell tracking and quantitative morphology analysis, we document marked variation in cell body helical parameters and flagellum number among H. pylori strains leading to distinct and broad speed distributions in broth and viscous gastric mucin media. These distributions reflect both temporal variation in swimming speed and morphologic variation within the population. Isogenic mutants with straight-rod morphology showed 7-21% reduction in speed and a lower fraction of motile bacteria. Mutational perturbation of flagellum number revealed a 19% increase in speed with 4 versus 3 median flagellum number. Resistive force theory modeling incorporating variation of both cell shape and flagellum number predicts qualitative speed differences of 10-30% among strains. However, quantitative comparisons suggest resistive force theory underestimates the influence of cell body shape on speed for helical shaped bacteria.

  4. Changing Numbers of Neuronal and Non-Neuronal Cells Underlie Postnatal Brain Growth in the Rat

    National Research Council Canada - National Science Library

    Fabiana Bandeira; Roberto Lent; Suzana Herculano-Houzel; Jon H. Kaas

    2009-01-01

    .... To test this hypothesis, here we investigate quantitatively the postnatal changes in the total number of neuronal and non-neuronal cells in the developing rat brain, and examine how these changes...

  5. T-cell triggering thresholds are modulated by the number of antigen within individual T-cell receptor clusters

    Energy Technology Data Exchange (ETDEWEB)

    Manz, Boryana N. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Univ. of California, Berkeley, CA (United States); Jackson, Bryan L. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Petit, Rebecca S. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dustin, Michael L. [New York School of Medicine, New York, NY (United States); Groves, Jay [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-05-31

    T cells react to extremely small numbers of activating agonist peptides. Spatial organization of T-cell receptors (TCR) and their peptide-major histocompatibility complex (pMHC) ligands into microclusters is correlated with T-cell activation. In this study, we have designed an experimental strategy that enables control over the number of agonist peptides per TCR cluster, without altering the total number engaged by the cell. Supported membranes, partitioned with grids of barriers to lateral mobility, provide an effective way of limiting the total number of pMHC ligands that may be assembled within a single TCR cluster. Observations directly reveal that restriction of pMHC content within individual TCR clusters can decrease T-cell sensitivity for triggering initial calcium flux at fixed total pMHC density. Further analysis suggests that triggering thresholds are determined by the number of activating ligands available to individual TCR clusters, not by the total number encountered by the cell. Results from a series of experiments in which the overall agonist density and the maximum number of agonist per TCR cluster are independently varied in primary T cells indicate that the most probable minimal triggering unit for calcium signaling is at least four pMHC in a single cluster for this system. In conclusion, this threshold is unchanged by inclusion of coagonist pMHC, but costimulation of CD28 by CD80 can modulate the threshold lower.

  6. Human obesity reduces the number of hepatic leptin receptor (ob-R) expressing NK cells.

    Science.gov (United States)

    Lautenbach, Anne; Breitmeier, Dirk; Kuhlmann, Susanne; Nave, Heike

    2011-01-01

    In the industrialized world, obesity is an increasing socioeconomic health problem. Obese subjects have a higher risk of developing several types of cancer. NK cells are an integral component of the innate immune system, able to destruct tumor cells. The adipokine leptin plays a crucial role in the development of obesity and its related diseases. Peripheral leptin signaling is modulated by the liver. The aim of this study was to evaluate the number of hepatic NK cells (CD56+) and the number of leptin-receptor positive (Ob-R+) cells in the livers of five normal-weight and five obese humans. Livers were removed during autopsy and accurately defined sections were stained immunohistochemically and CD56+, Ob-R+, and double-positive cells were quantified. Results revealed a dramatic reduction of NK cells and Ob-R-expressing NK cells in the livers of obese individuals. The present study demonstrates, for the first time, body-weight-dependent numbers of hepatic NK cells. This supports the hypothesis of obesity-associated alterations of immune cell numbers in different human organs.

  7. Visceral adipose inflammation in obesity is associated with critical alterations in tregulatory cell numbers.

    Directory of Open Access Journals (Sweden)

    Jeffrey Deiuliis

    Full Text Available BACKGROUND: The development of insulin resistance (IR in mouse models of obesity and type 2 diabetes mellitus (DM is characterized by progressive accumulation of inflammatory macrophages and subpopulations of T cells in the visceral adipose. Regulatory T cells (Tregs may play a critical role in modulating tissue inflammation via their interactions with both adaptive and innate immune mechanisms. We hypothesized that an imbalance in Tregs is a critical determinant of adipose inflammation and investigated the role of Tregs in IR/obesity through coordinated studies in mice and humans. METHODS AND FINDINGS: Foxp3-green fluorescent protein (GFP "knock-in" mice were randomized to a high-fat diet intervention for a duration of 12 weeks to induce DIO/IR. Morbidly obese humans without overt type 2 DM (n = 13 and lean controls (n = 7 were recruited prospectively for assessment of visceral adipose inflammation. DIO resulted in increased CD3(+CD4(+, and CD3(+CD8(+ cells in visceral adipose with a striking decrease in visceral adipose Tregs. Treg numbers in visceral adipose inversely correlated with CD11b(+CD11c(+ adipose tissue macrophages (ATMs. Splenic Treg numbers were increased with up-regulation of homing receptors CXCR3 and CCR7 and marker of activation CD44. In-vitro differentiation assays showed an inhibition of Treg differentiation in response to conditioned media from inflammatory macrophages. Human visceral adipose in morbid obesity was characterized by an increase in CD11c(+ ATMs and a decrease in foxp3 expression. CONCLUSIONS: Our experiments indicate that obesity in mice and humans results in adipose Treg depletion. These changes appear to occur via reduced local differentiation rather than impaired homing. Our findings implicate a role for Tregs as determinants of adipose inflammation.

  8. Number Density of Mast Cells in the Primo Nodes of Rats.

    Science.gov (United States)

    Gil, HyunJi; Bae, Kyoung-Hee; Kim, LiJung; Kim, SungChul; Soh, Kwang-Sup

    2015-12-01

    Mast cells (MCs) play a major role in allergic reactions. Surprisingly, the acupuncture points have a higher density of MCs compared with nonacupoints in the skin, which is consistent with the augmentation of the immune function by acupuncture treatment. We hypothesized that the primo vascular system (PVS), which was proposed as the anatomical structure of the acupuncture points and meridians, should have a high density of MCs. In order to test that hypothesis, we investigated the primo nodes isolated from the surfaces of internal organs, such as the liver, the small and the large intestines, and the bladder. The harvested primo nodes were stained with toluidine blue, and the MCs were easily recognized by their red-purple stains and their characteristic granules. The results showed a high density of MCs in the primo nodes and confirmed the hypothesis. The MCs were uniformly distributed in the nodes. The relative concentration of the MCs with respect to other cells was ∼15%. We divided the sizes of the primo nodes into three classes: large, medium, and small. The number density and the relative concentration of MCs did not show a size-dependence. The current work suggests that the PVS may participate in the immune response to allergic inflammation, which closely involves MCs.

  9. Sexual activity increases the number of newborn cells in the accessory olfactory bulb of male rats.

    Directory of Open Access Journals (Sweden)

    Wendy ePortillo

    2012-07-01

    Full Text Available In rodents, sexual behavior depends on the adequate detection of sexually relevant stimuli. The olfactory bulb (OB is a region of the adult mammalian brain undergoing constant cell renewal by continuous integration of new granular and periglomerular neurons in the accessory (AOB and main (MOB olfactory bulbs. The proliferation, migration, survival, maturation, and integration of these new cells to the OB depend on the stimulus that the subjects received. We have previously shown that 15 days after females control (paced the sexual interaction an increase in the number of cells is observed in the AOB. No changes are observed in the number of cells when females are not allowed to control the sexual interaction. In the present study we investigated if in male rats sexual behavior increases the number of new cells in the OB. Male rats were divided in five groups: 1 males that did not receive any sexual stimulation, 2 males that were exposed to female odors, 3 males that mated for 1 h and could not pace their sexual interaction, 4 males that paced their sexual interaction and ejaculated 1 time and 5 males that paced their sexual interaction and ejaculated 3 times. All males received three injections of the DNA synthesis marker bromodeoxyuridine at 1h intervals, starting 1h before the beginning of the behavioral test. Fifteen days later, males were sacrificed and the brains were processed to identify new cells and to evaluate if they differentiated into neurons. The number of newborn cells increased in the granular cell layer (also known as the internal cell layer of the AOB in males that ejaculated one or three times controlling (paced the rate of the sexual interaction. Some of these new cells were identified as neurons. In contrast, no significant differences were found in the mitral cell layer (also known as the external cell layer and glomerular cell layer of the AOB. In addition, no significant differences were found between groups in the MOB in

  10. GDF11 modulates NGN3+ islet progenitor cell number and promotes beta-cell differentiation in pancreas development.

    Science.gov (United States)

    Harmon, Erin B; Apelqvist, Asa A; Smart, Nora G; Gu, Xueying; Osborne, Douglas H; Kim, Seung K

    2004-12-01

    Identification of endogenous signals that regulate expansion and maturation of organ-specific progenitor cells is a major goal in studies of organ development. Here we provide evidence that growth differentiation factor 11 (GDF11), a member of the TGF-beta ligand family, governs the number and maturation of islet progenitor cells in mouse pancreas development. Gdf11 is expressed in embryonic pancreatic epithelium during formation of islet progenitor cells that express neurogenin 3. Mice deficient for Gdf11 harbor increased numbers of NGN3+ cells, revealing that GDF11 negatively regulates production of islet progenitor cells. Despite a marked expansion of these NGN3+ islet progenitors, mice lacking Gdf11 have reduced beta-cell numbers and evidence of arrested beta-cell development, indicating that GDF11 is also required for beta-cell maturation. Similar precursor and islet cell phenotypes are observed in mice deficient for SMAD2, an intracellular signaling factor activated by TGF-beta signals. Our data suggest that Gdf11 and Smad2 regulate islet cell differentiation in parallel to the Notch pathway, which previously has been shown to control development of NGN3+ cells. Thus, our studies reveal mechanisms by which GDF11 regulates the production and maturation of islet progenitor cells in pancreas development.

  11. Irrecoverable pressure loss coefficients for two out-of-plane piping elbows at high Reynolds number

    Energy Technology Data Exchange (ETDEWEB)

    Coffield, R.D.; Hammond, R.B.; McKeown, P.T.

    1999-02-08

    Pressure drops of multiple piping elbows were experimentally determined for high Reynolds number flows. The testing described has been performed in order to reduce uncertainties in the currently used methods for predicting irrecoverable pressure losses and also to provide a qualification database for computational fluid dynamics (CFD) computer codes. The earlier high Reynolds number correlations had been based on extrapolations over several orders of magnitude in Reynolds number from where the original database existed. Recent single elbow test data shows about a factor of two lower elbow pressure loss coefficient (at 40x 106 Reynolds number) than those from current correlations. This single piping elbow data has been extended in this study to a multiple elbow configuration of two elbows that are 90o out-of-plane relative to each other. The effects of separation distance and Reynolds number have been correlated and presented in a form that can be used for design application. Contrary to earlier extrapolations from low Reynolds numbers (Re c 1.0x 106), a strong Reynolds number dependence was found to exist. The combination of the high Reynolds number single elbow data with the multiple elbow interaction effects measured in this study shows that earlier design correlations are conservative by significant margins at high Reynolds numbers. Qualification of CFD predictions with this new high Reynolds number database will help guide the need for additional high Reynolds number testing of other piping configurations. The study also included velocity measurements at several positions downstream of the first and second test elbows using an ultrasonic flowmeter. Reasonable agreement after the first test elbow was found relative to flow fields that are known to exist from low Reynolds number visual tests and also from CFD predictions. This data should help to qualify CFD predictions of the three-dimensional flow stream downstream of the second test elbow.

  12. Dermal papilla cell number specifies hair size, shape and cycling and its reduction causes follicular decline.

    Science.gov (United States)

    Chi, Woo; Wu, Eleanor; Morgan, Bruce A

    2013-04-01

    Although the hair shaft is derived from the progeny of keratinocyte stem cells in the follicular epithelium, the growth and differentiation of follicular keratinocytes is guided by a specialized mesenchymal population, the dermal papilla (DP), that is embedded in the hair bulb. Here we show that the number of DP cells in the follicle correlates with the size and shape of the hair produced in the mouse pelage. The same stem cell pool gives rise to hairs of different sizes or types in successive hair cycles, and this shift is accompanied by a corresponding change in DP cell number. Using a mouse model that allows selective ablation of DP cells in vivo, we show that DP cell number dictates the size and shape of the hair. Furthermore, we confirm the hypothesis that the DP plays a crucial role in activating stem cells to initiate the formation of a new hair shaft. When DP cell number falls below a critical threshold, hair follicles with a normal keratinocyte compartment fail to generate new hairs. However, neighbouring follicles with a few more DP cells can re-enter the growth phase, and those that do exploit an intrinsic mechanism to restore both DP cell number and normal hair growth. These results demonstrate that the mesenchymal niche directs stem and progenitor cell behaviour to initiate regeneration and specify hair morphology. Degeneration of the DP population in mice leads to the types of hair thinning and loss observed during human aging, and the results reported here suggest novel approaches to reversing hair loss.

  13. Cell-free DNA copy number variations in plasma from colorectal cancer patients.

    Science.gov (United States)

    Li, Jian; Dittmar, Rachel L; Xia, Shu; Zhang, Huijuan; Du, Meijun; Huang, Chiang-Ching; Druliner, Brooke R; Boardman, Lisa; Wang, Liang

    2017-08-01

    To evaluate the clinical utility of cell-free DNA (cfDNA), we performed whole-genome sequencing to systematically examine plasma cfDNA copy number variations (CNVs) in a cohort of patients with colorectal cancer (CRC, n = 80), polyps (n = 20), and healthy controls (n = 35). We initially compared cfDNA yield in 20 paired serum-plasma samples and observed significantly higher cfDNA concentration in serum (median = 81.20 ng, range 7.18-500 ng·mL(-1) ) than in plasma (median = 5.09 ng, range 3.76-62.8 ng·mL(-1) ) (P copy number analysis showed common CNVs in multiple chromosomal regions, including amplifications on 1q, 8q, and 5q and deletions on 1p, 4q, 8p, 17p, 18q, and 22q. Copy number changes were also evident in genes critical to the cell cycle, DNA repair, and WNT signaling pathways. To evaluate whether cumulative copy number changes were associated with tumor stages, we calculated plasma genomic abnormality in colon cancer (PGA-C) score by summing the most significant CNVs. The PGA-C score showed predictive performance with an area under the curve from 0.54 to 0.84 for CRC stages I-IV. Locus-specific copy number analysis identified nine genomic regions where CNVs were significantly associated with survival in stage III-IV CRC patients. A multivariate model using six of nine genomic regions demonstrated a significant association of high-risk score with shorter survival (HR = 5.33, 95% CI = 6.76-94.44, P < 0.0001). Our study demonstrates the importance of using plasma (rather than serum) to test tumor-related genomic variations. Plasma cfDNA-based tests can capture tumor-specific genetic changes and may provide a measurable classifier for assessing clinical outcomes in advanced CRC patients. © 2017 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

  14. Mast cell numbers in airway smooth muscle and PC(20)AMP in asthma and COPD

    NARCIS (Netherlands)

    Liesker, J. J. W.; ten Hacken, N. H. T.; Rutgers, S. R.; Zeinstra-Smith, M.; Postma, D. S.; Timens, W.

    2007-01-01

    Introduction: Most patients with asthma and many patients with COPD show bronchial hyperresponsiveness to adenosine (BHRAMP). BHRAMP may be caused by release of mast cell histamine, which induces smooth muscle contraction. Aim of the study: To evaluate whether mast cell numbers in airway smooth musc

  15. Estimation of the total number of mast cells in the human umbilical cord. A methodological study.

    Science.gov (United States)

    Engberg Damsgaard, T M; Windelborg Nielsen, B; Sørensen, F B; Henriques, U; Schiøtz, P O

    1992-09-01

    The aim of the present study was to estimate the total number of mast cells in the human umbilical cord. Using 50 microns-thick paraffin sections, made from a systematic random sample of umbilical cord, the total number of mast cells per cord was estimated using a combination of the optical disector and fractionated sampling. The mast cell of the human umbilical cord was found in Wharton's jelly, most frequently in close proximity to the three blood vessels. No consistent pattern of variation in mast cell numbers from the fetal end of the umbilical cord towards the placenta was seen. The total number of mast cells found in the umbilical cord was 5,200,000 (median), range 2,800,000-16,800,000 (n = 7), that is 156,000 mast cells per gram umbilical cord (median), range 48,000-267,000. Thus, the umbilical cord constitutes an adequate source of mast cells for further investigation of these cells in the newborn, e.g. for describing their functional and secretory characteristics and possible clinical relevance in relation to the development of allergic, inflammatory and immunological diseases in infancy and childhood.

  16. Providing cell phone numbers and email addresses to Patients: the physician's perspective

    Directory of Open Access Journals (Sweden)

    Freud Tamar

    2011-03-01

    Full Text Available Abstract Background The provision of cell phone numbers and email addresses enhances the accessibility of medical consultations, but can add to the burden of physicians' routine clinical practice and affect their free time. The objective was to assess the attitudes of physicians to providing their telephone number or email address to patients. Methods Primary care physicians in the southern region of Israel completed a structured questionnaire that related to the study objective. Results The study population included 120 primary care physicians with a mean age of 41.2 ± 8.5, 88 of them women (73.3%. Physicians preferred to provide their cell phone number rather than their email address (P = 0.0007. They preferred to answer their cell phones only during the daytime and at predetermined times, but would answer email most hours of the day, including weekends and holidays (P = 0.001. More physicians (79.7% would have preferred allotted time for email communication than allotted time for cell phone communication (50%. However, they felt that email communication was more likely to lead to miscommunication than telephone calls (P = 0.0001. There were no differences between male and female physicians on the provision of cell phone numbers or email addresses to patients. Older physicians were more prepared to provide cell phone numbers that younger ones (P = 0.039. Conclusions The attitude of participating physicians was to provide their cell phone number or email address to some of their patients, but most of them preferred to give out their cell phone number.

  17. Large Eddy Simulations of Kelvin Helmholtz instabilities at high Reynolds number stratified flows

    Science.gov (United States)

    Brown, Dana; Goodman, Lou; Raessi, Mehdi

    2015-11-01

    Simulations of Kelvin Helmholtz Instabilities (KHI) at high Reynolds numbers are performed using the Large Eddy Simulation technique. Reynolds numbers up to 100,000 are achieved using our model. The resulting data set is used to examine the effect of Reynolds number on various statistics, including dissipation flux coefficient, turbulent kinetic energy budget, and Thorpe length scale. It is shown that KHI are qualitatively different at high Re, up to and including the onset of vortex pairing and billow collapse and quantitatively different afterward. The effect of Richardson number is also examined. The results are discussed as they apply to ocean experiments.

  18. Macronuclear Actin copy number variations in single cells of different Pseudokeronopsis (Alveolata, Ciliophora) populations.

    Science.gov (United States)

    Huang, Lijuan; Lu, Xuefen; Zhu, Changyu; Lin, Xiaofeng; Yi, Zhenzhen

    2017-06-01

    Macronuclear chromosomes of ciliates, especially those of Spirotrichea, Armophorea and Phyllopharyngea, are extensively fragmented and their copy numbers vary significantly. A recent study suggested that parental RNA molecules regulate macronuclear copy number in offspring cells after conjugation. However, variations in patterns of macronuclear copy number during vegetative growth are not clear. Previous studies have reported macronuclear copy numbers of population averages, potentially masking individual variation. In the present investigation, we studied copy number variations among closely related species of Pseudokeronopsis and among individual cells during vegetative growth. We found that macronuclear copy numbers of Actin I, II in our Pseudokeronopsis populations are in the same range as in other spirotrichean species, but no close relationship is detected among morphologically related Pseudokeronopsis species. Copy numbers of three cells within each Pseudokeronopsis population range from 1.01 to 4.55 fold, suggesting that stochastic influences copy number during vegetative growth. Furthermore, the absence of a relationship between macronuclear copy numbers of Actin I and Actin II within Pseudokeronopsis is consistent with the fact that these genes are located on different gene-sized macronuclear chromosomes. Additionally, Actin II might have disappeared in P. carnea during evolution within the Actin gene family. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Insulin demand regulates β cell number via the unfolded protein response.

    Science.gov (United States)

    Sharma, Rohit B; O'Donnell, Amy C; Stamateris, Rachel E; Ha, Binh; McCloskey, Karen M; Reynolds, Paul R; Arvan, Peter; Alonso, Laura C

    2015-10-01

    Although stem cell populations mediate regeneration of rapid turnover tissues, such as skin, blood, and gut, a stem cell reservoir has not been identified for some slower turnover tissues, such as the pancreatic islet. Despite lacking identifiable stem cells, murine pancreatic β cell number expands in response to an increase in insulin demand. Lineage tracing shows that new β cells are generated from proliferation of mature, differentiated β cells; however, the mechanism by which these mature cells sense systemic insulin demand and initiate a proliferative response remains unknown. Here, we identified the β cell unfolded protein response (UPR), which senses insulin production, as a regulator of β cell proliferation. Using genetic and physiologic models, we determined that among the population of β cells, those with an active UPR are more likely to proliferate. Moreover, subthreshold endoplasmic reticulum stress (ER stress) drove insulin demand-induced β cell proliferation, through activation of ATF6. We also confirmed that the UPR regulates proliferation of human β cells, suggesting that therapeutic UPR modulation has potential to expand β cell mass in people at risk for diabetes. Together, this work defines a stem cell-independent model of tissue homeostasis, in which differentiated secretory cells use the UPR sensor to adapt organ size to meet demand.

  20. High-Quality Random Number Generation Software for High-Performance Computing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Random number (RN) generation is the key software component that permits random sampling. Software for parallel RN generation (RNG) should be based on RNGs that are...

  1. Copy Number Variation Analysis by Array Analysis of Single Cells Following Whole Genome Amplification.

    Science.gov (United States)

    Dimitriadou, Eftychia; Zamani Esteki, Masoud; Vermeesch, Joris Robert

    2015-01-01

    Whole genome amplification is required to ensure the availability of sufficient material for copy number variation analysis of a genome deriving from an individual cell. Here, we describe the protocols we use for copy number variation analysis of non-fixed single cells by array-based approaches following single-cell isolation and whole genome amplification. We are focusing on two alternative protocols, an isothermal and a PCR-based whole genome amplification method, followed by either comparative genome hybridization (aCGH) or SNP array analysis, respectively.

  2. High numbers of heat-loving bacteria found in cold Arctic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2009-09-15

    This article reported on a study of subzero sediments in the Arctic Ocean off the Norwegian island of Spitsbergen where scientists from the University of Calgary detected high numbers of thermophilic bacteria. The spores may offer an opportunity to trace seepages of fluids from hot sub-seafloor habitats and potentially indicate undiscovered offshore petroleum reservoirs. The Arctic spores that appear to have been transported from deeper hot spots were revived during experimental incubations at 40 to 60 degrees Celsius. Ongoing surveys are expected to identify the source, or sources, of these misplaced microbes. Since these bacteria are anaerobic, their high abundance and steady supply into the sediments indicate they are coming from a large oxygen-free habitat. One possible source may be a deep pressurized oil reservoir from which upward-leaking hydrocarbons carry bacteria into overlying seawater. Another source could be related to fluid circulation through warm ocean crust at spreading ridges. The thermophiles may get carried out of the abyssal hot spots by ocean currents that disperse them to the cold sediments. The spores also offer insight for understanding how biodiversity is maintained by the passive dispersal of small cells over large distances.

  3. Cyclin D3 coordinates the cell cycle during differentiation to regulate erythrocyte size and number.

    Science.gov (United States)

    Sankaran, Vijay G; Ludwig, Leif S; Sicinska, Ewa; Xu, Jian; Bauer, Daniel E; Eng, Jennifer C; Patterson, Heide Christine; Metcalf, Ryan A; Natkunam, Yasodha; Orkin, Stuart H; Sicinski, Piotr; Lander, Eric S; Lodish, Harvey F

    2012-09-15

    Genome-wide association studies (GWASs) have identified a genetic variant of moderate effect size at 6p21.1 associated with erythrocyte traits in humans. We show that this variant affects an erythroid-specific enhancer of CCND3. A Ccnd3 knockout mouse phenocopies these erythroid phenotypes, with a dramatic increase in erythrocyte size and a concomitant decrease in erythrocyte number. By examining human and mouse primary erythroid cells, we demonstrate that the CCND3 gene product cyclin D3 regulates the number of cell divisions that erythroid precursors undergo during terminal differentiation, thereby controlling erythrocyte size and number. We illustrate how cell type-specific specialization can occur for general cell cycle components-a finding resulting from the biological follow-up of unbiased human genetic studies.

  4. Data on the number and frequency of scientific literature citations for established medulloblastoma cell lines

    Directory of Open Access Journals (Sweden)

    D.P. Ivanov

    2016-12-01

    Full Text Available This article collates information about the number of scientific articles mentioning each of the established medulloblastoma cell lines, derived through a systematic search of Web of Science, Scopus and Google Scholar in 2016. The data for each cell line have been presented as raw number of citations, percentage share of the total citations for each search engine and as an average percentage between the three search engines. In order to correct for the time since each cell line has been in use, the raw citation data have also been divided by the number of years since the derivation of each cell line. This is a supporting article for a review of in vitro models of medulloblastoma published in “in vitro models of medulloblastoma: choosing the right tool for the job” (D.P. Ivanov, D.A. Walker, B. Coyle, A.M. Grabowska, 2016 [1].

  5. Zac1 functions through TGFβII to negatively regulate cell number in the developing retina

    Directory of Open Access Journals (Sweden)

    Götz Magdalena

    2007-06-01

    Full Text Available Abstract Background Organs are programmed to acquire a particular size during development, but the regulatory mechanisms that dictate when dividing progenitor cells should permanently exit the cell cycle and stop producing additional daughter cells are poorly understood. In differentiated tissues, tumor suppressor genes maintain a constant cell number and intact tissue architecture by controlling proliferation, apoptosis and cell dispersal. Here we report a similar role for two tumor suppressor genes, the Zac1 zinc finger transcription factor and that encoding the cytokine TGFβII, in the developing retina. Results Using loss and gain-of-function approaches, we show that Zac1 is an essential negative regulator of retinal size. Zac1 mutants develop hypercellular retinae due to increased progenitor cell proliferation and reduced apoptosis at late developmental stages. Consequently, supernumerary rod photoreceptors and amacrine cells are generated, the latter of which form an ectopic cellular layer, while other retinal cells are present in their normal number and location. Strikingly, Zac1 functions as a direct negative regulator of a rod fate, while acting cell non-autonomously to modulate amacrine cell number. We implicate TGFβII, another tumor suppressor and cytokine, as a Zac1-dependent amacrine cell negative feedback signal. TGFβII and phospho-Smad2/3, its downstream effector, are expressed at reduced levels in Zac1 mutant retinae, and exogenous TGFβII relieves the mutant amacrine cell phenotype. Moreover, treatment of wild-type retinae with a soluble TGFβ inhibitor and TGFβ receptor II (TGFβRII conditional mutants generate excess amacrine cells, phenocopying the Zac1 mutant phenotype. Conclusion We show here that Zac1 has an essential role in cell number control during retinal development, akin to its role in tumor surveillance in mature tissues. Furthermore, we demonstrate that Zac1 employs a novel cell non-autonomous strategy to

  6. High quality copy number and genotype data from FFPE samples using Molecular Inversion Probe (MIP) microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuker; Carlton, Victoria E.H.; Karlin-Neumann, George; Sapolsky, Ronald; Zhang, Li; Moorhead, Martin; Wang, Zhigang C.; Richardson, Andrea L.; Warren, Robert; Walther, Axel; Bondy, Melissa; Sahin, Aysegul; Krahe, Ralf; Tuna, Musaffe; Thompson, Patricia A.; Spellman, Paul T.; Gray, Joe W.; Mills, Gordon B.; Faham, Malek

    2009-02-24

    A major challenge facing DNA copy number (CN) studies of tumors is that most banked samples with extensive clinical follow-up information are Formalin-Fixed Paraffin Embedded (FFPE). DNA from FFPE samples generally underperforms or suffers high failure rates compared to fresh frozen samples because of DNA degradation and cross-linking during FFPE fixation and processing. As FFPE protocols may vary widely between labs and samples may be stored for decades at room temperature, an ideal FFPE CN technology should work on diverse sample sets. Molecular Inversion Probe (MIP) technology has been applied successfully to obtain high quality CN and genotype data from cell line and frozen tumor DNA. Since the MIP probes require only a small ({approx}40 bp) target binding site, we reasoned they may be well suited to assess degraded FFPE DNA. We assessed CN with a MIP panel of 50,000 markers in 93 FFPE tumor samples from 7 diverse collections. For 38 FFPE samples from three collections we were also able to asses CN in matched fresh frozen tumor tissue. Using an input of 37 ng genomic DNA, we generated high quality CN data with MIP technology in 88% of FFPE samples from seven diverse collections. When matched fresh frozen tissue was available, the performance of FFPE DNA was comparable to that of DNA obtained from matched frozen tumor (genotype concordance averaged 99.9%), with only a modest loss in performance in FFPE. MIP technology can be used to generate high quality CN and genotype data in FFPE as well as fresh frozen samples.

  7. EGFR expression and copy number changes in low T-stage oral squamous cell carcinomas.

    Science.gov (United States)

    Rössle, Matthias; Weber, Claudia S; Züllig, Lena; Graf, Nicole; Jochum, Wolfram; Stöckli, Sandro J; Moch, Holger; Huber, Gerhard F

    2013-08-01

    EGFR-directed therapies are used to treat patients with advanced head and neck squamous cell carcinoma (SCC). As it is still unclear whether or not EGFR amplification represents an early or late event in head and neck SCC progression, we aimed to determine the frequency of abnormalities of EGFR protein and gene copy numbers in early oral SCC. A tissue microarray of cancer tissue from 120 patients with pT1/2 oral SCC was constructed. We investigated EGFR protein expression by immunohistochemistry. EGFR gene copy enumeration was performed using fluorescence in-situ hybridization (FISH) and the novel automated silver in-situ hybridization (SISH) technology. Of early oral SCC, 19.3% showed high, 57.1% moderate and 23.6% low EGFR expression. EGFR amplification/polysomy was identified in 8% and 9% of cases by FISH and SISH, respectively. EGFR-SISH had a high concordance with EGFR-FISH (kappa value = 1.0), and both methods showed high conformity with EGFR immunohistochemistry (P = 0.001 and P = 0.006, respectively). No correlation was found of EGFR protein expression or gene amplification status with pT or pN stage. Only a small subgroup of early oral SCC is characterized by EGFR amplification, which can be identified reliably using EGFR-SISH technology. This finding suggests that EGFR gene amplification mostly occurs in advanced stages of oral SCC. © 2013 John Wiley & Sons Ltd.

  8. Long-term administration of valacyclovir reduces the number of Epstein-Barr virus (EBV)-infected B cells but not the number of EBV DNA copies per B cell in healthy volunteers.

    Science.gov (United States)

    Hoshino, Yo; Katano, Harutaka; Zou, Ping; Hohman, Patricia; Marques, Adriana; Tyring, Stephen K; Follmann, Dean; Cohen, Jeffrey I

    2009-11-01

    Epstein-Barr virus (EBV) establishes a latent infection in B cells in the blood, and the latent EBV load in healthy individuals is generally stable over time, maintaining a "set point." It is unknown if the EBV load changes after long-term antiviral therapy in healthy individuals. We treated volunteers with either valacyclovir (valaciclovir) or no antiviral therapy for 1 year and measured the amount of EBV DNA in B cells every 3 months with a novel, highly sensitive assay. The number of EBV-infected B cells decreased in subjects receiving valacyclovir (half-life of 11 months; P = 0.02) but not in controls (half-life of 31 years; P = 0.86). The difference in the slopes of the lines for the number of EBV-infected B cells over time for the valacyclovir group versus the control group approached significance (P = 0.054). In contrast, the number of EBV DNA copies per B cell remained unchanged in both groups (P = 0.62 and P = 0.92 for the control and valacyclovir groups, respectively). Valacyclovir reduces the frequency of EBV-infected B cells when administered over a long period and, in theory, might allow eradication of EBV from the body if reinfection does not occur.

  9. Changes of number of cells expressing proliferation and progenitor cell markers with age in rabbit intervertebral discs

    Institute of Scientific and Technical Information of China (English)

    Miersalijiang Yasen; Qinming Fei; William C Hutton; Jian Zhang; Jian Dong; Xiaoxing Jiang; Feng Zhang

    2013-01-01

    Basic knowledge about the normal regeneration process within the intervertebral disc (IVD) is important to the understanding of the underlying biology.The presence of progenitor and stem cells in IVD has been verified.However,changes of number of progenitor and stem cells with age are still unknown.In this study,changes of cell proliferation and progenitor cell markers with age in IVD cells from rabbits of two different ages were investigated using flow cytometry,immunohistochemistry,real-time polymerase chain reaction,and western blot analysis.Proliferating cell nuclear antigen (PCNA) was chosen as a marker for proliferation,and Notch1,Jagged1,C-KIT,CD166 were chosen as stem/progenitor cell markers.Cell cycle analysis showed that cell number in the G2/M phase of the young rabbits was significantly higher than that of mature rabbits.Immunohistochemical staining demonstrated the expression of PCNA,C-KIT,CD166,Notch1,and Jagged1 in both young and mature annulus fibrosus (AF).Protein expressions of these cell markers in the young rabbits were all significantly higher than those in the mature rabbits.The expression levels of PCNA,CD166,C-KIT,Jagged1 were significantly higher in the AF,and PCNA,C-KIT in the nucleus pulposus from young rabbits than those from the mature rabbits.These findings demonstrated that both proliferation and progenitor cells exist in rabbit IVDs and the number of cells expressing proliferation and progenitor cell markers decreases with age in the rabbit IVD cells.Methods that are designed to maintain the endogenous progenitor cells and stimulate their proliferation could be successful in preventing or inhibiting degenerative disc disease.

  10. An increased number of mast cells in the sclerae of alloxan-diabetic mice.

    Science.gov (United States)

    Jansson, L; Naeser, P

    1987-04-01

    The number of mast cells in the sclerae and retinae has been investigated in alloxan-diabetic mice, in obese-hyperglycaemic mice and in non-diabetic, lean control animals. In contrast to the alloxan-diabetic mice the obese-hyperglycaemic animals have increased circulating inulin levels. In the sclerae of alloxan-diabetic mice the number of mast cells was significantly (P less than 0.05) increased. No increase in mast cell content could be observed in the sclerae of the obese-hyperglycaemic mice. No mast cells could be observed in the retina in any of the experimental groups. It is concluded that lack of insulin may be of importance for the accumulation of mast cells in the sclerae of mice with hyperglycaemia.

  11. Pretreatment T lymphocyte numbers are contributing to the prognostic significance of absolute lymphocyte numbers in B-cell non-Hodgkins lymphomas.

    Science.gov (United States)

    Gergely, Lajos; Váncsa, Andrea; Miltényi, Zsófia; Simon, Zsófia; Baráth, Sándor; Illés, Árpád

    2011-06-01

    Targeted immuno-chemotherapy resulted in greatly improved survival of B cell lymphoma patients. Several prognostic markers are investigated, amongst them the pretreatment absolute lymphocyte numbers. We investigated lymphocyte subpopulations and correlated this data with prognosis of patients. 88 patients (mean age: 56 years, 18-88, median follow up 32 months) with B cell lymphomas were investigated. There were 51 DLBCL, 16 Follicular NHL, 4 MALT, 7 Marginal Zone NHL, 10 Small lymphocytic cases were investigated. Our data showed that overall survival was statistically significant up to the 0.9 G/l absolute lymphocyte numbers as dividers between the subgroups. The CD19+ B cell numbers, or the CD56+/CD3- NK cell numbers did not represent any significant differences between subgroups. However CD3+, CD4+ and CD8+ T cells were differentiating statistically significant subgroups. Pretreatment CD3+ cell number less than 700/ul and CD8+ cell number less than 200/ul were corresponding with significantly inferior overall survival. These could be verified in the bad prognostic IPI group as well. Our data further support the importance of pretreatment lymphocyte numbers and highlight CD3+ and CD8+ lymphocytes to be the key factors in predicting outcome.

  12. The number of cell types, information content, and the evolution of complex multicellularity

    Directory of Open Access Journals (Sweden)

    Karl J. Niklas

    2014-12-01

    Full Text Available The number of different cell types (NCT characterizing an organism is often used to quantify organismic complexity. This method results in the tautology that more complex organisms have a larger number of different kinds of cells, and that organisms with more different kinds of cells are more complex. This circular reasoning can be avoided (and simultaneously tested when NCT is plotted against different measures of organismic information content (e.g., genome or proteome size. This approach is illustrated by plotting the NCT of representative diatoms, green and brown algae, land plants, invertebrates, and vertebrates against data for genome size (number of base-pairs, proteome size (number of amino acids, and proteome functional versatility (number of intrinsically disordered protein domains or residues. Statistical analyses of these data indicate that increases in NCT fail to keep pace with increases in genome size, but exceed a one-to-one scaling relationship with increasing proteome size and with increasing numbers of intrinsically disordered protein residues. We interpret these trends to indicate that comparatively small increases in proteome (and not genome size are associated with disproportionate increases in NCT, and that proteins with intrinsically disordered domains enhance cell type diversity and thus contribute to the evolution of complex multicellularity.

  13. Modulation of Mitochondrial DNA Copy Number to Induce Hepatocytic Differentiation of Human Amniotic Epithelial Cells.

    Science.gov (United States)

    Vaghjiani, Vijesh; Cain, Jason E; Lee, William; Vaithilingam, Vijayaganapathy; Tuch, Bernard E; St John, Justin C

    2017-09-05

    Mitochondrial deoxyribonucleic acid (mtDNA) copy number is tightly regulated during pluripotency and differentiation. There is increased demand of cellular adenosine triphosphate (ATP) during differentiation for energy-intensive cell types such as hepatocytes and neurons to meet the cell's functional requirements. During hepatocyte differentiation, mtDNA copy number should be synchronously increased to generate sufficient ATP through oxidative phosphorylation. Unlike bone marrow mesenchymal cells, mtDNA copy number failed to increase by 28 days of differentiation of human amniotic epithelial cells (hAEC) into hepatocyte-like cells (HLC) despite their expression of some end-stage hepatic markers. This was due to higher levels of DNA methylation at exon 2 of POLGA, the mtDNA-specific replication factor. Treatment with a DNA demethylation agent, 5-azacytidine, resulted in increased mtDNA copy number, reduced DNA methylation at exon 2 of POLGA, and reduced hepatic gene expression. Depletion of mtDNA followed by subsequent differentiation did not increase mtDNA copy number, but reduced DNA methylation at exon 2 of POLGA and increased expression of hepatic and pluripotency genes. We encapsulated hAEC in barium alginate microcapsules and subsequently differentiated them into HLC. Encapsulation resulted in no net increase of mtDNA copy number but a significant reduction in DNA methylation of POLGA. RNAseq analysis showed that differentiated HLC express hepatocyte-specific genes but also increased expression of inflammatory interferon genes. Differentiation in encapsulated cells showed suppression of inflammatory genes as well as increased expression of genes associated with hepatocyte function pathways and networks. This study demonstrates that an increase in classical hepatic gene expression can be achieved in HLC through encapsulation, although they fail to effectively regulate mtDNA copy number.

  14. Analysis of Syetem Reliability in Manufacturing Cell Based on Triangular Fuzzy Number

    Institute of Scientific and Technical Information of China (English)

    ZHANG Caibo; HAN Botang; SUN Changsen; XU Chunjie

    2006-01-01

    Due to lacking of test-data and field-data in reliability research during the design stage of manufacturing cell system. The degree of manufacturing cell system reliability research is increased. In order to deal with the deficient data and the uncertainty occurred from analysis and judgment, the paper discussed a method for studying reliability of manufacturing cell system through the analysis of fuzzy fault tree, which was based on triangular fuzzy number. At last, calculation case indicated that it would have great significance for ascertaining reliability index, maintenance and establishing keeping strategy towards manufacturing cell system.

  15. Frozen cord blood hematopoietic stem cells differentiate into higher numbers of functional natural killer cells in vitro than mobilized hematopoietic stem cells or freshly isolated cord blood hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Martha Luevano

    Full Text Available Adoptive natural killer (NK cell therapy relies on the acquisition of large numbers of NK cells that are cytotoxic but not exhausted. NK cell differentiation from hematopoietic stem cells (HSC has become an alluring option for NK cell therapy, with umbilical cord blood (UCB and mobilized peripheral blood (PBCD34(+ being the most accessible HSC sources as collection procedures are less invasive. In this study we compared the capacity of frozen or freshly isolated UCB hematopoietic stem cells (CBCD34(+ and frozen PBCD34(+ to generate NK cells in vitro. By modifying a previously published protocol, we showed that frozen CBCD34(+ cultures generated higher NK cell numbers without loss of function compared to fresh CBCD34(+ cultures. NK cells generated from CBCD34(+ and PBCD34(+ expressed low levels of killer-cell immunoglobulin-like receptors but high levels of activating receptors and of the myeloid marker CD33. However, blocking studies showed that CD33 expression did not impact on the functions of the generated cells. CBCD34(+-NK cells exhibited increased capacity to secrete IFN-γ and kill K562 in vitro and in vivo as compared to PBCD34(+-NK cells. Moreover, K562 killing by the generated NK cells could be further enhanced by IL-12 stimulation. Our data indicate that the use of frozen CBCD34(+ for the production of NK cells in vitro results in higher cell numbers than PBCD34(+, without jeopardizing their functionality, rendering them suitable for NK cell immunotherapy. The results presented here provide an optimal strategy to generate NK cells in vitro for immunotherapy that exhibit enhanced effector function when compared to alternate sources of HSC.

  16. Frozen cord blood hematopoietic stem cells differentiate into higher numbers of functional natural killer cells in vitro than mobilized hematopoietic stem cells or freshly isolated cord blood hematopoietic stem cells.

    Science.gov (United States)

    Luevano, Martha; Domogala, Anna; Blundell, Michael; Jackson, Nicola; Pedroza-Pacheco, Isabela; Derniame, Sophie; Escobedo-Cousin, Michelle; Querol, Sergio; Thrasher, Adrian; Madrigal, Alejandro; Saudemont, Aurore

    2014-01-01

    Adoptive natural killer (NK) cell therapy relies on the acquisition of large numbers of NK cells that are cytotoxic but not exhausted. NK cell differentiation from hematopoietic stem cells (HSC) has become an alluring option for NK cell therapy, with umbilical cord blood (UCB) and mobilized peripheral blood (PBCD34(+)) being the most accessible HSC sources as collection procedures are less invasive. In this study we compared the capacity of frozen or freshly isolated UCB hematopoietic stem cells (CBCD34(+)) and frozen PBCD34(+) to generate NK cells in vitro. By modifying a previously published protocol, we showed that frozen CBCD34(+) cultures generated higher NK cell numbers without loss of function compared to fresh CBCD34(+) cultures. NK cells generated from CBCD34(+) and PBCD34(+) expressed low levels of killer-cell immunoglobulin-like receptors but high levels of activating receptors and of the myeloid marker CD33. However, blocking studies showed that CD33 expression did not impact on the functions of the generated cells. CBCD34(+)-NK cells exhibited increased capacity to secrete IFN-γ and kill K562 in vitro and in vivo as compared to PBCD34(+)-NK cells. Moreover, K562 killing by the generated NK cells could be further enhanced by IL-12 stimulation. Our data indicate that the use of frozen CBCD34(+) for the production of NK cells in vitro results in higher cell numbers than PBCD34(+), without jeopardizing their functionality, rendering them suitable for NK cell immunotherapy. The results presented here provide an optimal strategy to generate NK cells in vitro for immunotherapy that exhibit enhanced effector function when compared to alternate sources of HSC.

  17. [Increase in the number of cancer stem cells after exposure to low-LET radiation].

    Science.gov (United States)

    Zamulaeva, I A; Matchuk, O N; Selivanova, E I; Andreev, V G; Lipunov, N M; Makarenko, S A; Zhavoronkov, L P; Saenko, A S

    2014-01-01

    Radioresistance of cancer stem cells (CSCs) is regarded as one of the possible causes of cancer recurrence after radiotherapy. Since the regularities and mechanisms of radiation effects on this population of cells have not been sufficiently studied, the aim of this work is to elucidate the changes in the CSC number after γ-irradiation in stable cultures of tumor cells in vitro and tumor tissue in vivo (in the course of radiation therapy of patients with cancers of the upper respiratory tract). CSCs were identified in the cell lines B16, MCF-7, HeLa by the ability to exclude the fluorescent dye Hoechst 33342 (SP method) 48-72 h after irradiation at the doses of 1-20 Gy and in biopsy material by immunophenotype CD44+CD24(-/low) before and 24 h after irradiation at the total dose of 10 Gy. The essential differences in the response of CSCs and other cancer cells were found after exposure to low-LET radiation. The absolute number of CSCs increased after a single exposure at the doses ranging from 1 to 5-10 Gy in different cell cultures, but a further dose increase maintained the current number of CSCs or decreased it. At the same time, the number of non CSCs significantly decreased with increasing doses of radiation exposure, as expected. Fractionated irradiation in vivo at a total dose of 10 Gy increased the relative amount of CSCs in most patients. The registered changes are an integral indicator of cell death, cell division delay immediately after irradiation, proliferation at a later time, possible dedifferentiation of non CSCs, etc. The exact contribution of each of them to the radiation-induced increase of the CSCs number is of considerable interest and requires further research.

  18. Expansion of Endothelial Progenitor Cells in High Density Dot Culture of Rat Bone Marrow Cells

    Science.gov (United States)

    Wang, Ling; Kretlow, James D.; Zhou, Guangdong; Cao, Yilin; Liu, Wei; Zhang, Wen Jie

    2014-01-01

    In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2×105 cells/cm2) by seeding total 9×105 cells into six high density dots or cultured in regular density (1.6×104 cells/cm2) with the same total number of cells. Flow cytometric analyses of the cells cultured for 15 days showed that high density cells exhibited smaller cell size and higher levels of marker expression related to EPCs when compared to regular density cultured cells. Functionally, these cells exhibited strong angiogenic potentials with better tubal formation in vitro and potent rescue of mouse ischemic limbs in vivo with their integration into neo-capillary structure. Global gene chip and ELISA analyses revealed up-regulated gene expression of adhesion molecules and enhanced protein release of pro-angiogenic growth factors in high density cultured cells. In summary, high density cell culture promotes expansion of bone marrow contained EPCs that are able to enhance tissue angiogenesis via paracrine growth factors and direct differentiation into endothelial cells. PMID:25254487

  19. The small GTPase Cdc42 modulates the number of exocytosis-competent dense-core vesicles in PC12 cells

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Mai [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Kitaguchi, Tetsuya [Cell Signaling Group, Waseda Bioscience Research Institute in Singapore (WABOIS), Waseda University, 11 Biopolis Way, 05-01/02 Helios, Singapore 138667 (Singapore); Numano, Rika [The Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tennpaku-cho, Toyohashi, Aichi 441-8580 (Japan); Ikematsu, Kazuya [Forensic Pathology and Science, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kakeyama, Masaki [Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Murata, Masayuki; Sato, Ken [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Tsuboi, Takashi, E-mail: takatsuboi@bio.c.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer Regulation of exocytosis by Rho GTPase Cdc42. Black-Right-Pointing-Pointer Cdc42 increases the number of fusion events from newly recruited vesicles. Black-Right-Pointing-Pointer Cdc42 increases the number of exocytosis-competent dense-core vesicles. -- Abstract: Although the small GTPase Rho family Cdc42 has been shown to facilitate exocytosis through increasing the amount of hormones released, the precise mechanisms regulating the quantity of hormones released on exocytosis are not well understood. Here we show by live cell imaging analysis under TIRF microscope and immunocytochemical analysis under confocal microscope that Cdc42 modulated the number of fusion events and the number of dense-core vesicles produced in the cells. Overexpression of a wild-type or constitutively-active form of Cdc42 strongly facilitated high-KCl-induced exocytosis from the newly recruited plasma membrane vesicles in PC12 cells. By contrast, a dominant-negative form of Cdc42 inhibited exocytosis from both the newly recruited and previously docked plasma membrane vesicles. The number of intracellular dense-core vesicles was increased by the overexpression of both a wild-type and constitutively-active form of Cdc42. Consistently, activation of Cdc42 by overexpression of Tuba, a Golgi-associated guanine nucleotide exchange factor for Cdc42 increased the number of intracellular dense-core vesicles, whereas inhibition of Cdc42 by overexpression of the Cdc42/Rac interactive binding domain of neuronal Wiskott-Aldrich syndrome protein decreased the number of them. These findings suggest that Cdc42 facilitates exocytosis by modulating both the number of exocytosis-competent dense-core vesicles and the production of dense-core vesicles in PC12 cells.

  20. Real time demonstration of high bitrate quantum random number generation with coherent laser light

    CERN Document Server

    Symul, T; Lam, P K; 10.1063/1.3597793

    2011-01-01

    We present a random number generation scheme that uses broadband measurements of the vacuum field contained in the radio-frequency sidebands of a single-mode laser. Even though the measurements may contain technical noise, we show that suitable algorithms can transform the digitized photocurrents into a string of random numbers that can be made arbitrarily correlated with a subset of the quantum fluctuations (high quantum correlation regime) or arbitrarily immune to environmental fluctuations (high environmental immunity). We demonstrate up to 2 Gbps of real time random number generation that were verified using standard randomness tests.

  1. STAT3 is a critical cell-intrinsic regulator of human unconventional T cell numbers and function.

    Science.gov (United States)

    Wilson, Robert P; Ives, Megan L; Rao, Geetha; Lau, Anthony; Payne, Kathryn; Kobayashi, Masao; Arkwright, Peter D; Peake, Jane; Wong, Melanie; Adelstein, Stephen; Smart, Joanne M; French, Martyn A; Fulcher, David A; Picard, Capucine; Bustamante, Jacinta; Boisson-Dupuis, Stephanie; Gray, Paul; Stepensky, Polina; Warnatz, Klaus; Freeman, Alexandra F; Rossjohn, Jamie; McCluskey, James; Holland, Steven M; Casanova, Jean-Laurent; Uzel, Gulbu; Ma, Cindy S; Tangye, Stuart G; Deenick, Elissa K

    2015-06-01

    Unconventional T cells such as γδ T cells, natural killer T cells (NKT cells) and mucosal-associated invariant T cells (MAIT cells) are a major component of the immune system; however, the cytokine signaling pathways that control their development and function in humans are unknown. Primary immunodeficiencies caused by single gene mutations provide a unique opportunity to investigate the role of specific molecules in regulating human lymphocyte development and function. We found that individuals with loss-of-function mutations in STAT3 had reduced numbers of peripheral blood MAIT and NKT but not γδ T cells. Analysis of STAT3 mosaic individuals revealed that this effect was cell intrinsic. Surprisingly, the residual STAT3-deficient MAIT cells expressed normal levels of the transcription factor RORγt. Despite this, they displayed a deficiency in secretion of IL-17A and IL-17F, but were able to secrete normal levels of cytokines such as IFNγ and TNF. The deficiency in MAIT and NKT cells in STAT3-deficient patients was mirrored by loss-of-function mutations in IL12RB1 and IL21R, respectively. Thus, these results reveal for the first time the essential role of STAT3 signaling downstream of IL-23R and IL-21R in controlling human MAIT and NKT cell numbers. © 2015 Wilson et al.

  2. STAT3 is a critical cell-intrinsic regulator of human unconventional T cell numbers and function

    Science.gov (United States)

    Wilson, Robert P.; Ives, Megan L.; Rao, Geetha; Lau, Anthony; Payne, Kathryn; Kobayashi, Masao; Arkwright, Peter D.; Peake, Jane; Wong, Melanie; Adelstein, Stephen; Smart, Joanne M.; French, Martyn A.; Fulcher, David A.; Picard, Capucine; Bustamante, Jacinta; Boisson-Dupuis, Stephanie; Gray, Paul; Stepensky, Polina; Warnatz, Klaus; Freeman, Alexandra F.; Rossjohn, Jamie; McCluskey, James; Holland, Steven M.; Casanova, Jean-Laurent; Uzel, Gulbu; Ma, Cindy S.

    2015-01-01

    Unconventional T cells such as γδ T cells, natural killer T cells (NKT cells) and mucosal-associated invariant T cells (MAIT cells) are a major component of the immune system; however, the cytokine signaling pathways that control their development and function in humans are unknown. Primary immunodeficiencies caused by single gene mutations provide a unique opportunity to investigate the role of specific molecules in regulating human lymphocyte development and function. We found that individuals with loss-of-function mutations in STAT3 had reduced numbers of peripheral blood MAIT and NKT but not γδ T cells. Analysis of STAT3 mosaic individuals revealed that this effect was cell intrinsic. Surprisingly, the residual STAT3-deficient MAIT cells expressed normal levels of the transcription factor RORγt. Despite this, they displayed a deficiency in secretion of IL-17A and IL-17F, but were able to secrete normal levels of cytokines such as IFNγ and TNF. The deficiency in MAIT and NKT cells in STAT3-deficient patients was mirrored by loss-of-function mutations in IL12RB1 and IL21R, respectively. Thus, these results reveal for the first time the essential role of STAT3 signaling downstream of IL-23R and IL-21R in controlling human MAIT and NKT cell numbers. PMID:25941256

  3. Genome-wide copy number profiling of mouse neural stem cells during differentiation

    Directory of Open Access Journals (Sweden)

    U. Fischer

    2015-09-01

    Full Text Available There is growing evidence that gene amplifications were present in neural stem and progenitor cells during differentiation. We used array-CGH to discover copy number changes including gene amplifications and deletions during differentiation of mouse neural stem cells using TGF-ß and FCS for differentiation induction. Array data were deposited in GEO (Gene Expression Omnibus, NCBI under accession number GSE35523. Here, we describe in detail the cell culture features and our TaqMan qPCR-experiments to validate the array-CGH analysis. Interpretation of array-CGH experiments regarding gene amplifications in mouse and further detailed analysis of amplified chromosome regions associated with these experiments were published by Fischer and colleagues in Oncotarget (Fischer et al., 2015. We provide additional information on deleted chromosome regions during differentiation and give an impressive overview on copy number changes during differentiation induction at a time line.

  4. Genome-wide copy number profiling to detect gene amplifications in neural progenitor cells

    Directory of Open Access Journals (Sweden)

    U. Fischer

    2014-12-01

    Full Text Available DNA sequence amplification occurs at defined stages during normal development in amphibians and flies and seems to be restricted in humans to drug-resistant and tumor cells only. We used array-CGH to discover copy number changes including gene amplifications and deletions during differentiation of human neural progenitor cells. Here, we describe cell culture features, DNA extraction, and comparative genomic hybridization (CGH analysis tailored towards the identification of genomic copy number changes. Further detailed analysis of amplified chromosome regions associated with this experiment, was published by Fischer and colleagues in PLOS One in 2012 (Fischer et al., 2012. We provide detailed information on deleted chromosome regions during differentiation and give an overview on copy number changes during differentiation induction for two representative chromosome regions.

  5. Generation and Evolution of High-Mach-Number Laser-Driven Magnetized Collisionless Shocks in the Laboratory

    Science.gov (United States)

    Schaeffer, D. B.; Fox, W.; Haberberger, D.; Fiksel, G.; Bhattacharjee, A.; Barnak, D. H.; Hu, S. X.; Germaschewski, K.

    2017-07-01

    We present the first laboratory generation of high-Mach-number magnetized collisionless shocks created through the interaction of an expanding laser-driven plasma with a magnetized ambient plasma. Time-resolved, two-dimensional imaging of plasma density and magnetic fields shows the formation and evolution of a supercritical shock propagating at magnetosonic Mach number Mms≈12 . Particle-in-cell simulations constrained by experimental data further detail the shock formation and separate dynamics of the multi-ion-species ambient plasma. The results show that the shocks form on time scales as fast as one gyroperiod, aided by the efficient coupling of energy, and the generation of a magnetic barrier between the piston and ambient ions. The development of this experimental platform complements present remote sensing and spacecraft observations, and opens the way for controlled laboratory investigations of high-Mach number collisionless shocks, including the mechanisms and efficiency of particle acceleration.

  6. DSMC simulations of leading edge flat-plate boundary layer flows at high Mach number

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The flow over a 2D leading-edge flat plate is studied at Mach number Ma = (Uinf /√{kBTinf / m }) in the range Boltzmann constant. The variation of streamwise velocity, temperature, number-density, and mean free path along the wall normal direction away from the plate surface is studied. The qualitative nature of the streamwise velocity at high Mach number is similar to those in the incompressible limit (parabolic profile). However, there are important differences. The amplitudes of the streamwise velocity increase as the Mach number increases and turned into a more flatter profile near the wall. There is significant velocity and temperature slip at the surface of the plate, and the slip increases as the Mach number is increased. It is interesting to note that for the highest Mach numbers considered here, the streamwise velocity at the wall exceeds the sound speed, and the flow is supersonic throughout the flow domain.

  7. Quantification of effective exoelectrogens by most probable number (MPN) in a microbial fuel cell.

    Science.gov (United States)

    Heidrich, Elizabeth S; Curtis, Thomas P; Woodcock, Stephen; Dolfing, Jan

    2016-10-01

    The objective of this work was to quantify the number of exoelectrogens in wastewater capable of producing current in a microbial fuel cell by adapting the classical most probable number (MPN) methodology using current production as end point. Inoculating a series of microbial fuel cells with various dilutions of domestic wastewater and with acetate as test substrate yielded an apparent number of exoelectrogens of 17perml. Using current as a proxy for activity the apparent exoelectrogen growth rate was 0.03h(-1). With starch or wastewater as more complex test substrates similar apparent growth rates were obtained, but the apparent MPN based numbers of exoelectrogens in wastewater were significantly lower, probably because in contrast to acetate, complex substrates require complex food chains to deliver the electrons to the electrodes. Consequently, the apparent MPN is a function of the combined probabilities of members of the food chain being present.

  8. Is Ultra-High Reynolds Number Necessary for Comprehensive Log Scaling in a Turbulent Boundary Layer?

    CERN Document Server

    Dixit, Shivsai Ajit

    2015-01-01

    Experiments in an extraordinary turbulent boundary layer called the sink flow, displaying a perfect streamwise invariance, show a wide extent of logarithmic scaling for moments of streamwise velocity up to order 12, even at moderate Reynolds numbers. This is in striking contrast to canonical constant-pressure turbulent boundary layers that show such comprehensive log scaling only at ultra-high Reynolds numbers. This suggests that for comprehensive log scaling, ultra-high-Reynolds-number is not a necessary condition; while specific details of the sink flow are special, the relevance to general turbulent boundary layers is that the sink flow underscores the importance of the streamwise invariance condition that needs to be met in a general flow for obtaining log scaling. Indeed, a simple theory shows that, for log scaling in the inertial sublayer, the invariance of dimensionless mean velocity and higher-order moments along a mean streamline is a necessary and sufficient condition. Ultra-high Reynolds number pri...

  9. Multiscale structures of resistive magnetic reconnection at high magnetic Reynolds numbers

    Science.gov (United States)

    Miyoshi, Takahiro; Kusano, Kanya

    Magnetic reconnection is the most important process of explosive phenomena in space plasmas. The magnetic Reynolds number for the space plasmas are extremely high in general since those plasmas are thought to be collisionless or semi-collisional. However, magnetic reconnection rate becomes low as magnetic Reynolds number increases within the framework of a stationary resistive MHD model. Thus, modern models of magnetic reconnection often include kinetic effects such as the Hall effect to explain realistic explosive magnetic reconnection. It is thought, on the other hand, that the MHD approximation is valid for the plasmas within a very wide range of scales since the scale gap between the macro-and micro-scale is quite large, e.g., in the solar corona, the ratio of the macro to micro will be more than 107 . Such multiscale structures of MHD with wide range of scales, however, have not been clarified so far. Therefore, in this paper, resistive magnetic reconnection at high magnetic Reynolds numbers are investigated using very high-resolution MHD simulations. Simulation results show that the magnetic energy at high magnetic Reynolds numbers is explosively released, while that at not-so-high magnetic Reynolds numbers is steadily dissipated. In the case of high magnetic Reynolds numbers, multiple small scale plasmoids are intermittently created and ejected via secondary tearing modes in a nonlinearly developed thin current sheet. It is revealed that a secondary plasmoid is not only accelerated up to a local magnetosonic speed toward the down-stream region but also perturbs the up-stream region. Thus, complicated multiscale structures appear around the magnetic field reversal layer. Perspective for the high-resolution simulation of extremely high magnetic Reynolds numbers will be also discussed.

  10. Physical exercise decreases the number of fetal cells in maternal blood

    DEFF Research Database (Denmark)

    Schlütter, Jacob Mørup; Kirkegaard, Ida; Christensen, Connie Britta;

    liability company). Fetal cells in the blood, bound to fetal cell specific markers, were initially isolated by magnetic cell sorting, then stained with a cocktail of intracellular antibodies, identified and counted. Information about 6 variables reflecting the physical activity of the participants......Physical exercise decreases the number of fetal cells in maternal blood J. M. Schlütter1, I. Kirkegaard1, B. Christensen2, S. Kølvraa3, N. Uldbjerg1 1. Department of Gynecology and Obstetrics, Aarhus University Hospital, Skejby, Aarhus N, Denmark. 2. FCMB ApS, Vejle, Denmark. 3. Department...... of Clinical Genetics, Vejle Hospital, Vejle, Denmark Objectives We have established a robust method to specifically identify and isolate a subgroup of fetal cells in maternal blood (fcmb) at a gestational age of 12 weeks. The concentration of these cells, however, varies considerably among pregnant women...

  11. Automatic Quantification of the Number of Intracellular Compartments in Arabidopsis thaliana Root Cells

    Science.gov (United States)

    Bayle, Vincent; Platre, Matthieu Pierre; Jaillais, Yvon

    2017-01-01

    In the era of quantitative biology, it is increasingly required to quantify confocal microscopy images. If possible, quantification should be performed in an automatic way, in order to avoid bias from the experimenter, to allow the quantification of a large number of samples, and to increase reproducibility between laboratories. In this protocol, we describe procedures for automatic counting of the number of intracellular compartments in Arabidopsis root cells, which can be used for example to study endocytosis or secretory trafficking pathways and to compare membrane organization between different genotypes or treatments. While developed for Arabidopsis roots, this method can be used on other tissues, cell types and plant species. PMID:28255574

  12. Three-tier regulation of cell number plasticity by neurotrophins and Tolls in Drosophila

    Science.gov (United States)

    Phizacklea, Mark; Gay, Nicholas J.

    2017-01-01

    Cell number plasticity is coupled to circuitry in the nervous system, adjusting cell mass to functional requirements. In mammals, this is achieved by neurotrophin (NT) ligands, which promote cell survival via their Trk and p75NTR receptors and cell death via p75NTR and Sortilin. Drosophila NTs (DNTs) bind Toll receptors instead to promote neuronal survival, but whether they can also regulate cell death is unknown. In this study, we show that DNTs and Tolls can switch from promoting cell survival to death in the central nervous system (CNS) via a three-tier mechanism. First, DNT cleavage patterns result in alternative signaling outcomes. Second, different Tolls can preferentially promote cell survival or death. Third, distinct adaptors downstream of Tolls can drive either apoptosis or cell survival. Toll-6 promotes cell survival via MyD88–NF-κB and cell death via Wek-Sarm-JNK. The distribution of adaptors changes in space and time and may segregate to distinct neural circuits. This novel mechanism for CNS cell plasticity may operate in wider contexts. PMID:28373203

  13. Arabidopsis thaliana leaves with altered chloroplast numbers and chloroplast movement exhibit impaired adjustments to both low and high light.

    Science.gov (United States)

    Königer, Martina; Delamaide, Joy A; Marlow, Elizabeth D; Harris, Gary C

    2008-01-01

    The effects of chloroplast number and size on the capacity for blue light-dependent chloroplast movement, the ability to increase light absorption under low light, and the susceptibility to photoinhibition were investigated in Arabidopsis thaliana. Leaves of wild-type and chloroplast number mutants with mean chloroplast numbers ranging from 120 to two per mesophyll cell were analysed. Chloroplast movement was monitored as changes in light transmission through the leaves. Light transmission was used as an indicator of the ability of leaves to optimize light absorption. The ability of leaves to deal with 3 h of high light stress at 10 degrees C and their capacity to recover in low light was determined by measuring photochemical efficiencies of PSII using chlorophyll a fluorescence. Chloroplast movement was comparable in leaves ranging in chloroplast numbers from 120 to 30 per mesophyll cell: the final light transmission levels after exposure to 0.1 (accumulation response) and 100 micromol photons m(-2) s(-1) (avoidance response) were indistinguishable, the chloroplasts responded quickly to small increases in light intensity and the kinetics of movement were similar. However, when chloroplast numbers per mesophyll cell decreased to 18 or below, the accumulation response was significantly reduced. The avoidance response was only impaired in mutants with nine or fewer chloroplasts, both in terms of final transmission levels and the speed of movement. Only mutants lacking both blue light receptors (phot1/phot2) or those with drastically reduced chloroplast numbers and severely impacted avoidance responses showed a reduced ability to recover from high light stress.

  14. Changes in mast cell number and stem cell factor expression in human skin after radiotherapy for breast cancer.

    Science.gov (United States)

    Westbury, Charlotte B; Freeman, Alex; Rashid, Mohammed; Pearson, Ann; Yarnold, John R; Short, Susan C

    2014-05-01

    Mast cells are involved in the pathogenesis of radiation fibrosis and may be a therapeutic target. The mechanism of increased mast cell number in relation to acute and late tissue responses in human skin was investigated. Punch biopsies of skin 1 and 15-18 months after breast radiotherapy and a contralateral control biopsy were collected. Mast cells were quantified by immunohistochemistry using the markers c-Kit and tryptase. Stem cell factor (SCF) and collagen-1 expression was analysed by qRT-PCR. Clinical photographic scores were performed at post-surgical baseline and 18 months and 5 years post-radiotherapy. Primary human dermal microvascular endothelial cell (HDMEC) cultures were exposed to 2Gy ionising radiation and p53 and SCF expression was analysed by Western blotting and ELISA. Dermal mast cell numbers were increased at 1 (p=0.047) and 18 months (p=0.040) using c-Kit, and at 18 months (p=0.024) using tryptase immunostaining. Collagen-1 mRNA in skin was increased at 1 month (p=0.047) and 18 months (p=0.032) and SCF mRNA increased at 1 month (p=0.003). None of 16 cases scored had a change in photographic appearance at 5 years, compared to baseline. SCF expression was not increased in HDMECs irradiated in vitro. Increased mast cell number was associated with up-regulated collagen-1 expression in human skin at early and late time points. This increase could be secondary to elevated SCF expression at 1 month after radiotherapy. Although mast cells accumulate around blood vessels, no endothelial cell secretion of SCF was seen after in vitro irradiation. Modification of mast cell number and collagen-1 expression may be observed in skin at 1 and 18 months after radiotherapy in breast cancer patients with no change in photographic breast appearance at 5 years. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Testosterone replacement therapy can increase circulating endothelial progenitor cell number in men with late onset hypogonadism.

    Science.gov (United States)

    Liao, C-H; Wu, Y-N; Lin, F-Y; Tsai, W-K; Liu, S-P; Chiang, H-S

    2013-07-01

    Circulating endothelial progenitor cells (EPCs) are bone marrow-derived cells required for endothelial repair. A low EPC number can be considered as an independent predictor of endothelial dysfunction and future cardiovascular events. Recent evidence shows that patients with hypogonadal symptoms without other confounding risk factors have a low number of circulating progenitor cells (PCs) and EPCs, thus highlighting the role of testosterone in the proliferation and differentiation of EPCs. Here, we investigate if testosterone replacement therapy (TRT) can increase circulating EPC number in men with late onset hypogonadism. Forty-six men (age range, 40-73 years; mean age, 58.3 years) with hypogonadal symptoms were recruited, and 29 men with serum total testosterone (TT) levels less than 350 ng/dL received TRT using transdermal testosterone gel (Androgel; 1% testosterone at 5 g/day) for 12 months. Circulating EPC numbers (per 100 000 monocytes) were calculated using flow cytometry. There was no significant association between serum TT levels and the number of circulating EPCs before TRT. Compared with the number of mean circulating EPCs at baseline (9.5 ± 6.2), the number was significantly higher after 3 months (16.6 ± 11.1, p = 0.027), 6 months (20.3 ± 15.3, p = 0.006) and 12 months (27.2 ± 15.5, p = 0.017) of TRT. Thus, we conclude that serum TT levels before TRT are not significantly associated with the number of circulating EPCs in men with late onset hypogonadism. However, TRT can increase the number of circulating EPCs, which implies the benefit of TRT on endothelial function in hypogonadal men.

  16. Multigrid solution of the convection-diffusion equation with high-Reynolds number

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun [George Washington Univ., Washington, DC (United States)

    1996-12-31

    A fourth-order compact finite difference scheme is employed with the multigrid technique to solve the variable coefficient convection-diffusion equation with high-Reynolds number. Scaled inter-grid transfer operators and potential on vectorization and parallelization are discussed. The high-order multigrid method is unconditionally stable and produces solution of 4th-order accuracy. Numerical experiments are included.

  17. Spectroscopic diagnostics of superthermal electrons with high-number harmonic EC radiation in tokamak reactor plasmas

    Directory of Open Access Journals (Sweden)

    Minashin P.V.

    2015-01-01

    Full Text Available A method of spectroscopic diagnostics of the average perpendicular-to-magnetic-field momentum of the superthermal component of the electron velocity distribution (EVD, based on the high-number-harmonic electron cyclotron (EC radiation, is suggested for nuclear fusion-reactor plasmas under condition of a strong auxiliary heating (e.g. in tokamak DEMO, a next step after tokamak ITER. The method is based on solving an inverse problem for reconstruction of the EVD in parallel and perpendicular-to-magnetic-field components of electron momentum at high and moderate energies responsible for the emission of the high-number-harmonic EC radiation.

  18. The small-scale dynamo: Breaking universality at high Mach numbers

    CERN Document Server

    Schleicher, Dominik R G; Federrath, Christoph; Bovino, Stefano; Schmidt, Wolfram

    2013-01-01

    (Abridged) The small-scale dynamo may play a substantial role in magnetizing the Universe under a large range of conditions, including subsonic turbulence at low Mach numbers, highly supersonic turbulence at high Mach numbers and a large range of magnetic Prandtl numbers Pm, i.e. the ratio of kinetic viscosity to magnetic resistivity. Low Mach numbers may in particular lead to the well-known, incompressible Kolmogorov turbulence, while for high Mach numbers, we are in the highly compressible regime, thus close to Burgers turbulence. In this study, we explore whether in this large range of conditions, a universal behavior can be expected. Our starting point are previous investigations in the kinematic regime. Here, analytic studies based on the Kazantsev model have shown that the behavior of the dynamo depends significantly on Pm and the type of turbulence, and numerical simulations indicate a strong dependence of the growth rate on the Mach number of the flow. Once the magnetic field saturates on the current ...

  19. Adrenal adenomas: relationship between histologic lipid-rich cells and CT attenuation number

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takayuki E-mail: yamataka@rad.med.tohoku.ac.jp; Ishibashi, Tadashi; Saito, Haruo; Matsuhashi, Toshio; Majima, Kazuhiro; Tsuda, Masashi; Takahashi, Shoki; Moriya, Takuya

    2003-11-01

    Objective: To evaluate the relationship between lipid-rich cells of the adrenal adenoma and precontrast computed tomographic (CT) attenuation numbers in three clinical groups. Materials and Methods: Thirty-five surgically resected adrenal adenomas were used. The clinical diagnoses of the patients included 13 cases of primary aldosteronism, 15 cases of Cushing's syndrome, and 7 non-functioning tumors. The number of lipid-rich clear cells was counted using a microscopic eyepiece grid that contained 100 squares. The results were expressed as the percentages of lipid-rich areas. Results: There was a strong inverse linear relationship between the percentage of lipid-rich cells and the precontrast CT attenuation number (R{sup 2}=0.724, P<0.0001). There were significantly more lipid-rich cells in the primary aldosteronism and non-functioning tumor cases compared to cases of Cushing's syndrome (P=0.007 and 0.015, respectively). The CT attenuation numbers of the primary aldosteronism cases were significantly lower than those of Cushing's syndrome (P=0.0052). Furthermore, the CT attenuation numbers of the non-functioning tumor cases were lower than those of Cushing's syndrome cases. Conclusion: We showed that adrenal adenomas in primary aldosteronism and non-functioning tumors contain significantly more lipid-rich cells than those in Cushing's syndrome. They also showed significantly lower attenuation than that in Cushing's syndrome on CT scans. Our results suggest that precontrast CT attenuation numbers may be helpful in the differentiation of adenomas from non-adenomatous lesions, which include malignancies.

  20. The association between DRESS and the diminished numbers of peripheral B lymphocytes and natural killer cells.

    Science.gov (United States)

    Yazicioglu, Mehtap; Elmas, Reyhan; Turgut, Burhan; Genchallac, Tugba

    2012-05-01

    Drug reaction with eosinophilia and systemic symptoms (DRESS) is a drug-induced, severe multiorgan system reaction whose exact pathogenesis remains unknown. This study aimed at evaluating specific changes in peripheral blood lymphocyte subtypes associated with DRESS during antibiotic treatment. We analyzed six patients with DRESS. A complete blood count and peripheral blood lymphocytes immunophenotyping were carried out at symptom onset and at follow-up visits. Acute-phase reactants and liver enzymes were measured in all patients. Other tests - viral serology, serum immunoglobulin levels, and skin tests were performed when possible. B-cell counts were low in all patients at the onset of DRESS, and natural killer (NK) cells were low in all cases except one. During recovery, B-cell numbers were within a normal range in five patients. In one, there was even a 10-fold increase in B-cell counts, although the level was mildly low after 3 months. NK-cell numbers were within a normal range in three patients. The mean numbers of B cells and NK cells were significantly higher in the second samples compared to the values on admission. Serum IgA and IgM levels were low in one patient. The drug provocation test was positive with cefotaxime in one patient. Viral serology, performed on five patients, was negative. A decrease in B-cell and NK-cell counts was the most consistent finding associated with the onset of antibiotic-induced DRESS in our patients. This immunologic alteration might be a useful predictor of DRESS development.

  1. Mitochondrial DNA copy number is regulated by DNA methylation and demethylation of POLGA in stem and cancer cells and their differentiated progeny.

    Science.gov (United States)

    Lee, W; Johnson, J; Gough, D J; Donoghue, J; Cagnone, G L M; Vaghjiani, V; Brown, K A; Johns, T G; St John, J C

    2015-02-26

    Mitochondrial DNA (mtDNA) copy number is strictly regulated during differentiation so that cells with a high requirement for ATP generated through oxidative phosphorylation have high mtDNA copy number, whereas those with a low requirement have few copies. Using immunoprecipitation of DNA methylation on 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC), which distinguish between de novo DNA methylation and demethylation, respectively, we set out to determine whether DNA methylation at exon 2 of the human mtDNA-specific polymerase (DNA polymerase gamma A (POLGA)) regulates cell-specific mtDNA copy number in highly proliferative and terminally differentiated cells. Highly proliferative cancer and pluripotent and multipotent cells possessed low mtDNA copy number and were highly methylated at exon 2 of POLGA in contrast to post-mitotic cells. Unlike neural stem cells, cancer cells were unable to differentiate and remained extensively DNA methylated at exon 2 of POLGA. However, mtDNA depletion of cancer cells reduced DNA methylation at exon 2 of POLGA as they replenished mtDNA to form tumours in mice. Glioblastoma cells treated with the DNA demethylation agent 5-azacytidine over 28 days of astrocyte-induced differentiation demethylated exon 2 of POLGA leading to increased mtDNA copy number and expression of the astrocyte endpoint marker glial fibrillary acidic protein (GFAP). However, the demethylation agent vitamin C (VitC) was unable to sustain increased mtDNA copy number and differentiation, as was the case when VitC was withdrawn after short-term treatment. These data demonstrate that DNA demethylation of POLGA is an essential regulator of mtDNA copy number and cellular fate and that cancer cells are only able to modulate DNA methylation of POLGA and mtDNA copy number in the presence of a DNA demethylation agent that inhibits de novo methyltransferase 1 activity.

  2. Estimation Prospects of the Source Number Density of Ultra-high-energy Cosmic Rays

    OpenAIRE

    Takami, Hajime; Sato, Katsuhiko

    2007-01-01

    We discuss the possibility of accurately estimating the source number density of ultra-high-energy cosmic rays (UHECRs) using small-scale anisotropy in their arrival distribution. The arrival distribution has information on their source and source distribution. We calculate the propagation of UHE protons in a structured extragalactic magnetic field (EGMF) and simulate their arrival distribution at the Earth using our previously developed method. The source number density that can best reprodu...

  3. Mechanical properties of cancer cells depend on number of passages: Atomic force microscopy indentation study

    Science.gov (United States)

    Dokukin, Maxim E.; Guz, Natalia V.; Sokolov, Igor

    2017-08-01

    Here we investigate one of the key questions in cell biology, if the properties of cell lines depend on the number of passages in-vitro. It is generally assumed that the change of cell properties (phenotypic drift) is insignificant when the number of passages is low (<10) the changes were reported for passages higher than 30-40. We used quantitative indentation models to extract information on the elastic modulus of the cell body and parameters of the pericellular brush layer from indentation force curves, which are recorded by means of atomic force microscopy (AFM). Using this method, we tested the change of the cell properties of human cancer breast epithelial cell line, MCF-7 (ATCC® HTB-22™), within the passages between 2 and 10. In contrast to the previous expectations, we observed a substantial transient change of the elastic modulus of the cell body during the first four passages (up to 4 times). The changes in the parameters of the pericellular coat were less dramatic (up to 2 times) but still statistically significant.

  4. Number and importance of somatic cells in goat’s milk

    Directory of Open Access Journals (Sweden)

    Lidija Kozačinski

    2001-04-01

    Full Text Available Goat’s milk samples were examined on mastitis using stable procedure (California-mastitis test. 427 of the examined milk samples (46.82% had positive reaction from 1 to 3 while other 485 samples (53.18% had negative reaction on the mastitis test, indicating that no illness of mammary gland occurred. Number of somatic cells, counted using “Fossomatic” counter, was 1.3x106/ml average. By comparing the results of mastitis-test evaluation (CMT with the number of somatic cells and findings of mastitis agents in milk showed that higher number of somatic cells is not the only indication of goat’s mammary gland illness. Mastitis-test is method that can exclude inflammation of goat’s mammary gland, but every positive reaction should be confirmed or eliminate with bacteriological examination. Based on the results of this research, it has been shown that the limit for somatic cells number in goat's milk can be over 1 000 000/ml.

  5. Cigarette smoking during early pregnancy reduces the number of embryonic germ and somatic cells

    DEFF Research Database (Denmark)

    Mamsen, Linn; Lutterodt, M C; Andersen, Elisabeth Anne Wreford

    2010-01-01

    BACKGROUND: Cigarette smoking during pregnancy is associated with negative reproductive consequences for male fetuses in adult life such as reduced testicular volume and sperm concentration. The present study evaluates the number of germ and somatic cells present in human embryonic first-trimeste......BACKGROUND: Cigarette smoking during pregnancy is associated with negative reproductive consequences for male fetuses in adult life such as reduced testicular volume and sperm concentration. The present study evaluates the number of germ and somatic cells present in human embryonic first...... confounders such as alcohol and coffee consumption (P = 0.002). The number of germ cells in embryonic gonads, irrespective of gender, was also significantly reduced by 41% (95% CI 58-19%, P = 0.001) in exposed versus non-exposed embryonic gonads. CONCLUSIONS: Prenatal exposure to maternal cigarette smoke...... reduces the number of germ and somatic cells in embryonic male and female gonads. This effect may have long-term consequences on the future fertility of exposed offspring. These findings may provide one potential cause of the reduced fertility observed during recent years....

  6. Reduced cell number in the neocortical part of the human fetal brain in Down syndrome

    DEFF Research Database (Denmark)

    Larsen, K.B.; Laursen, H.; Graem, N.

    2008-01-01

    Mental retardation is seen in all individuals with Down syndrome (DS) and different brain abnormalities are reported. The aim of this study was to investigate if mental retardation at least in part is a result of a lower cell number in the neocortical part of the human fetal forebrain. We therefore...

  7. Transfection of small numbers of human endothelial cells by electroporation and synthetic amphiphiles

    NARCIS (Netherlands)

    van Leeuwen, E B; van der Veen, A Y; Hoekstra, D; Engberts, J B; Halie, M R; van der Meer, J; Ruiters, M H

    1999-01-01

    OBJECTIVES: This study compared the efficiency of electroporation and synthetic amphiphiles. (SAINT-2pp/DOPE) in transfecting small numbers of human endothelial cells. METHODS AND RESULTS: Optimal transfection conditions were tested and appeared to be 400 V and 960 microF for electroporation and a 1

  8. Stereological estimation of total cell numbers in the human cerebral and cerebellar cortex

    DEFF Research Database (Denmark)

    Walløe, Solveig; Pakkenberg, Bente; Fabricius, Katrine

    2014-01-01

    Our knowledge of the relationship between brain structure and cognitive function is still limited. Human brains and individual cortical areas vary considerably in size and shape. Studies of brain cell numbers have historically been based on biased methods, which did not always result in correct e...

  9. Active Control of Flow Separation on a High-Lift System with Slotted Flap at High Reynolds Number

    Science.gov (United States)

    Khodadoust, Abdollah; Washburn, Anthony

    2007-01-01

    The NASA Energy Efficient Transport (EET) airfoil was tested at NASA Langley's Low- Turbulence Pressure Tunnel (LTPT) to assess the effectiveness of distributed Active Flow Control (AFC) concepts on a high-lift system at flight scale Reynolds numbers for a medium-sized transport. The test results indicate presence of strong Reynolds number effects on the high-lift system with the AFC operational, implying the importance of flight-scale testing for implementation of such systems during design of future flight vehicles with AFC. This paper describes the wind tunnel test results obtained at the LTPT for the EET high-lift system for various AFC concepts examined on this airfoil.

  10. Role of the Number of Microtubules in Chromosome Segregation during Cell Division

    CERN Document Server

    Bertalan, Zsolt; La Porta, Caterina A M; Zapperi, Stefano

    2015-01-01

    Faithful segregation of genetic material during cell division requires alignment of chromosomes between two spindle poles and attachment of their kinetochores to each of the poles. Failure of these complex dynamical processes leads to chromosomal instability (CIN), a characteristic feature of several diseases including cancer. While a multitude of biological factors regulating chromosome congression and bi-orientation have been identified, it is still unclear how they are integrated so that coherent chromosome motion emerges from a large collection of random and deterministic processes. Here we address this issue by a three dimensional computational model of motor-driven chromosome congression and bi-orientation during mitosis. Our model reveals that successful cell division requires control of the total number of microtubules: if this number is too small bi-orientation fails, while if it is too large not all the chromosomes are able to congress. The optimal number of microtubules predicted by our model compa...

  11. Heat transfer for falling film evaporation of industrially relevant fluids up to very high Prandtl numbers

    Science.gov (United States)

    Gourdon, Mathias; Karlsson, Erik; Innings, Fredrik; Jongsma, Alfred; Vamling, Lennart

    2016-02-01

    In many industrial applications, falling film evaporation is an attractive technique for solvent removal due to high heat transfer and low residence times. Examples are the powder production in the dairy industry and in kraft pulp production process to remove water from so called black liquor. Common for both applications is that the fluids exhibit high viscosities in industrial practice. In this paper, results from experimental studies on both black liquor and a dairy product are reported for Prandtl numbers up to 800. The results are compared with several existing correlation in literature, and the need for a modified correlation is recognized especially to cover higher Prandtl-numbers. The following correlation for the turbulent flow region with 3 literature data from one additional study on two other fluids (propylene glycol and cyclohexanol) with fairly high Prandtl-numbers, from 40 to 58 and from 45 to 155 respectively and the agreement was within ±40 %.

  12. Measuring ATP Concentration in a Small Number of Murine Hematopoietic Stem Cells.

    Science.gov (United States)

    Szade, Krzysztof; Zukowska, Monika; Jozkowicz, Alicja; Dulak, Jozef

    2016-01-01

    The metabolism of quiescent adult stem cells differs from the metabolism of differentiated cells. The metabolic processes are tightly regulated and their alterations disturb function of stem cells. One of the indicators of metabolic status of cells is the ATP level. While the method of measuring the ATP levels has been known for many years, estimating ATP levels in small population of defined stem cells isolated directly from the tissue has remained challenging. Here, we show our method of measuring the ATP levels in hematopoietic stem cells sorted from murine bone marrow. We used magnetic sorting as well as cell sorter and adopted the commonly used bioluminescence-based detection kits in described protocol. Our strategy allows to measure ATP levels in 1000 highly purified HSC.

  13. Stratification of clear cell renal cell carcinoma (ccRCC) genomes by gene-directed copy number alteration (CNA) analysis.

    Science.gov (United States)

    Thiesen, H-J; Steinbeck, F; Maruschke, M; Koczan, D; Ziems, B; Hakenberg, O W

    2017-01-01

    Tumorigenic processes are understood to be driven by epi-/genetic and genomic alterations from single point mutations to chromosomal alterations such as insertions and deletions of nucleotides up to gains and losses of large chromosomal fragments including products of chromosomal rearrangements e.g. fusion genes and proteins. Overall comparisons of copy number alterations (CNAs) presented in 48 clear cell renal cell carcinoma (ccRCC) genomes resulted in ratios of gene losses versus gene gains between 26 ccRCC Fuhrman malignancy grades G1 (ratio 1.25) and 20 G3 (ratio 0.58). Gene losses and gains of 15762 CNA genes were mapped to 795 chromosomal cytoband loci including 280 KEGG pathways. CNAs were classified according to their contribution to Fuhrman tumour gradings G1 and G3. Gene gains and losses turned out to be highly structured processes in ccRCC genomes enabling the subclassification and stratification of ccRCC tumours in a genome-wide manner. CNAs of ccRCC seem to start with common tumour related gene losses flanked by CNAs specifying Fuhrman grade G1 losses and CNA gains favouring grade G3 tumours. The appearance of recurrent CNA signatures implies the presence of causal mechanisms most likely implicated in the pathogenesis and disease-outcome of ccRCC tumours distinguishing lower from higher malignant tumours. The diagnostic quality of initial 201 genes (108 genes supporting G1 and 93 genes G3 phenotypes) has been successfully validated on published Swiss data (GSE19949) leading to a restricted CNA gene set of 171 CNA genes of which 85 genes favour Fuhrman grade G1 and 86 genes Fuhrman grade G3. Regarding these gene sets overall survival decreased with the number of G3 related gene losses plus G3 related gene gains. CNA gene sets presented define an entry to a gene-directed and pathway-related functional understanding of ongoing copy number alterations within and between individual ccRCC tumours leading to CNA genes of prognostic and predictive value.

  14. Prospectus: towards the development of high-fidelity models of wall turbulence at large Reynolds number

    Science.gov (United States)

    Klewicki, J. C.; Chini, G. P.; Gibson, J. F.

    2017-01-01

    Recent and on-going advances in mathematical methods and analysis techniques, coupled with the experimental and computational capacity to capture detailed flow structure at increasingly large Reynolds numbers, afford an unprecedented opportunity to develop realistic models of high Reynolds number turbulent wall-flow dynamics. A distinctive attribute of this new generation of models is their grounding in the Navier–Stokes equations. By adhering to this challenging constraint, high-fidelity models ultimately can be developed that not only predict flow properties at high Reynolds numbers, but that possess a mathematical structure that faithfully captures the underlying flow physics. These first-principles models are needed, for example, to reliably manipulate flow behaviours at extreme Reynolds numbers. This theme issue of Philosophical Transactions of the Royal Society A provides a selection of contributions from the community of researchers who are working towards the development of such models. Broadly speaking, the research topics represented herein report on dynamical structure, mechanisms and transport; scale interactions and self-similarity; model reductions that restrict nonlinear interactions; and modern asymptotic theories. In this prospectus, the challenges associated with modelling turbulent wall-flows at large Reynolds numbers are briefly outlined, and the connections between the contributing papers are highlighted. This article is part of the themed issue ‘Toward the development of high-fidelity models of wall turbulence at large Reynolds number’. PMID:28167585

  15. Quadruplex MAPH: improvement of throughput in high-resolution copy number screening

    Directory of Open Access Journals (Sweden)

    Walker Susan

    2009-09-01

    Full Text Available Abstract Background Copy number variation (CNV in the human genome is recognised as a widespread and important source of human genetic variation. Now the challenge is to screen for these CNVs at high resolution in a reliable, accurate and cost-effective way. Results Multiplex Amplifiable Probe Hybridisation (MAPH is a sensitive, high-resolution technology appropriate for screening for CNVs in a defined region, for a targeted population. We have developed MAPH to a highly multiplexed format ("QuadMAPH" that allows the user a four-fold increase in the number of loci tested simultaneously. We have used this method to analyse a genomic region of 210 kb, including the MSH2 gene and 120 kb of flanking DNA. We show that the QuadMAPH probes report copy number with equivalent accuracy to simplex MAPH, reliably demonstrating diploid copy number in control samples and accurately detecting deletions in Hereditary Non-Polyposis Colorectal Cancer (HNPCC samples. Conclusion QuadMAPH is an accurate, high-resolution method that allows targeted screening of large numbers of subjects without the expense of genome-wide approaches. Whilst we have applied this technique to a region of the human genome, it is equally applicable to the genomes of other organisms.

  16. Estimation of immune cell densities in immune cell conglomerates: an approach for high-throughput quantification.

    Directory of Open Access Journals (Sweden)

    Niels Halama

    Full Text Available BACKGROUND: Determining the correct number of positive immune cells in immunohistological sections of colorectal cancer and other tumor entities is emerging as an important clinical predictor and therapy selector for an individual patient. This task is usually obstructed by cell conglomerates of various sizes. We here show that at least in colorectal cancer the inclusion of immune cell conglomerates is indispensable for estimating reliable patient cell counts. Integrating virtual microscopy and image processing principally allows the high-throughput evaluation of complete tissue slides. METHODOLOGY/PRINCIPAL FINDINGS: For such large-scale systems we demonstrate a robust quantitative image processing algorithm for the reproducible quantification of cell conglomerates on CD3 positive T cells in colorectal cancer. While isolated cells (28 to 80 microm(2 are counted directly, the number of cells contained in a conglomerate is estimated by dividing the area of the conglomerate in thin tissues sections (< or =6 microm by the median area covered by an isolated T cell which we determined as 58 microm(2. We applied our algorithm to large numbers of CD3 positive T cell conglomerates and compared the results to cell counts obtained manually by two independent observers. While especially for high cell counts, the manual counting showed a deviation of up to 400 cells/mm(2 (41% variation, algorithm-determined T cell numbers generally lay in between the manually observed cell numbers but with perfect reproducibility. CONCLUSION: In summary, we recommend our approach as an objective and robust strategy for quantifying immune cell densities in immunohistological sections which can be directly implemented into automated full slide image processing systems.

  17. Dispersive nature of high mach number collisionless plasma shocks: Poynting flux of oblique whistler waves.

    Science.gov (United States)

    Sundkvist, David; Krasnoselskikh, V; Bale, S D; Schwartz, S J; Soucek, J; Mozer, F

    2012-01-13

    Whistler wave trains are observed in the foot region of high Mach number quasiperpendicular shocks. The waves are oblique with respect to the ambient magnetic field as well as the shock normal. The Poynting flux of the waves is directed upstream in the shock normal frame starting from the ramp of the shock. This suggests that the waves are an integral part of the shock structure with the dispersive shock as the source of the waves. These observations lead to the conclusion that the shock ramp structure of supercritical high Mach number shocks is formed as a balance of dispersion and nonlinearity.

  18. The effects of nozzle geometry on waterjet breakup at high Reynolds numbers

    Energy Technology Data Exchange (ETDEWEB)

    Vahedi Tafreshi, H.; Pourdeyhimi, B. [Nonwovens Cooperative Research Center, North Carolina State University, NC 27695-8301, Raleigh (United States)

    2003-10-01

    Waterjet breakup is traditionally considered to follow the Ohnesorge classification. In this classification, high Reynolds number waterjets are considered to atomize quickly after discharge. By generating a constricted waterjet where the water flow stays detached all the way through the nozzle, we have observed the first wind-induced breakup mode at high Reynolds numbers. Such a peculiar behavior, however, was not observed in non-constricted waterjets. Our results indicate that, constricted jets do not follow the Ohnesorge classification, in contrast to the non-constricted waterjets. We discuss the impact of nozzle geometry on the characteristics of waterjets and support our discussion by numerical simulations. (orig.)

  19. Association of activating KIR copy number variation of NK cells with containment of SIV replication in rhesus monkeys.

    Directory of Open Access Journals (Sweden)

    Ina Hellmann

    2011-12-01

    Full Text Available While the contribution of CD8⁺ cytotoxic T lymphocytes to early containment of HIV-1 spread is well established, a role for NK cells in controlling HIV-1 replication during primary infection has been uncertain. The highly polymorphic family of KIR molecules expressed on NK cells can inhibit or activate these effector cells and might therefore modulate their activity against HIV-1-infected cells. In the present study, we investigated copy number variation in KIR3DH loci encoding the only activating KIR receptor family in rhesus monkeys and its effect on simian immunodeficiency virus (SIV replication during primary infection in rhesus monkeys. We observed an association between copy numbers of KIR3DH genes and control of SIV replication in Mamu-A*01⁻ rhesus monkeys that express restrictive TRIM5 alleles. These findings provide further evidence for an association between NK cells and the early containment of SIV replication, and underscore the potential importance of activating KIRs in stimulating NK cell responses to control SIV spread.

  20. Qualification of a Method to Calculate the Irrecoverable Pressure Loss in High Reynolds Number Piping Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sigg, K. C.; Coffield, R. D.

    2002-09-01

    High Reynolds number test data has recently been reported for both single and multiple piping elbow design configurations at earlier ASME Fluid Engineering Division conferences. The data of these studies ranged up to a Reynolds number of 42 x 10[sup]6 which is significantly greater than that used to establish design correlations before the data was available. Many of the accepted design correlations, based on the lower Reynolds number data, date back as much as fifty years. The new data shows that these earlier correlations are extremely conservative for high Reynolds number applications. Based on the recent high Reynolds number information a new recommended method has been developed for calculating irrecoverable pressure loses in piping systems for design considerations such as establishing pump sizing requirements. This paper describes the recommended design approach and additional testing that has been performed as part of the qualification of the method. This qualification testing determined the irrecoverable pressure loss of a piping configuration that would typify a limiting piping section in a complicated piping network, i.e., multiple, tightly coupled, out-of-plane elbows in series under high Reynolds number flow conditions. The overall pressure loss measurements were then compared to predictions, which used the new methodology to assure that conservative estimates for the pressure loss (of the type used for pump sizing) were obtained. The recommended design methodology, the qualification testing and the comparison between the predictions and the test data are presented. A major conclusion of this study is that the recommended method for calculating irrecoverable pressure loss in piping systems is conservative yet significantly lower than predicted by early design correlations that were based on the extrapolation of low Reynolds number test data.

  1. ITER-W monoblocks under high pulse number transient heat loads at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Loewenhoff, Th., E-mail: T.Loewenhoff@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Linke, J., E-mail: J.Linke@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Pintsuk, G., E-mail: G.Pintsuk@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Pitts, R.A., E-mail: Richard.Pitts@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul-Lez-Durance (France); Riccardi, B., E-mail: Bruno.Riccardi@f4e.europa.eu [Fusion for Energy Joint Undertaking, Josep Pla No. 2 – T B3 7/01, Barcelona 08019 (Spain)

    2015-08-15

    In the context of using a full-tungsten (W) divertor for ITER, thermal shock resistance has become even more important as an issue that may potentially influence the long term performance. To address this issue a unique series of experiments has been performed on ITER-W monoblock mock ups in three EU high heat flux facilities: GLADIS (neutral beam), JUDITH 2 (electron beam) and Magnum-PSI (plasma beam). This paper discusses the JUDITH 2 experiments. Two different base temperatures, 1200 °C and 1500 °C, were chosen superimposed by ∼18,000/100,000 transient events (Δt = 0.48 ms) of 0.2 and 0.6 GW/m{sup 2}. Results showed a stronger surface deterioration at higher base temperature, quantified by an increase in roughening. This is intensified if the same test is done after preloading (exposure to high temperature without transients), especially at higher base temperature when the material recrystallizes.

  2. High-order lattice Boltzmann models for wall-bounded flows at finite Knudsen numbers.

    Science.gov (United States)

    Feuchter, C; Schleifenbaum, W

    2016-07-01

    We analyze a large number of high-order discrete velocity models for solving the Boltzmann-Bhatnagar-Gross-Krook equation for finite Knudsen number flows. Using the Chapman-Enskog formalism, we prove for isothermal flows a relation identifying the resolved flow regimes for low Mach numbers. Although high-order lattice Boltzmann models recover flow regimes beyond the Navier-Stokes level, we observe for several models significant deviations from reference results. We found this to be caused by their inability to recover the Maxwell boundary condition exactly. By using supplementary conditions for the gas-surface interaction it is shown how to systematically generate discrete velocity models of any order with the inherent ability to fulfill the diffuse Maxwell boundary condition accurately. Both high-order quadratures and an exact representation of the boundary condition turn out to be crucial for achieving reliable results. For Poiseuille flow, we can reproduce the mass flow and slip velocity up to the Knudsen number of 1. Moreover, for small Knudsen numbers, the Knudsen layer behavior is recovered.

  3. Prospectus: towards the development of high-fidelity models of wall turbulence at large Reynolds number

    Science.gov (United States)

    Klewicki, J. C.; Chini, G. P.; Gibson, J. F.

    2017-03-01

    Recent and on-going advances in mathematical methods and analysis techniques, coupled with the experimental and computational capacity to capture detailed flow structure at increasingly large Reynolds numbers, afford an unprecedented opportunity to develop realistic models of high Reynolds number turbulent wall-flow dynamics. A distinctive attribute of this new generation of models is their grounding in the Navier-Stokes equations. By adhering to this challenging constraint, high-fidelity models ultimately can be developed that not only predict flow properties at high Reynolds numbers, but that possess a mathematical structure that faithfully captures the underlying flow physics. These first-principles models are needed, for example, to reliably manipulate flow behaviours at extreme Reynolds numbers. This theme issue of Philosophical Transactions of the Royal Society A provides a selection of contributions from the community of researchers who are working towards the development of such models. Broadly speaking, the research topics represented herein report on dynamical structure, mechanisms and transport; scale interactions and self-similarity; model reductions that restrict nonlinear interactions; and modern asymptotic theories. In this prospectus, the challenges associated with modelling turbulent wall-flows at large Reynolds numbers are briefly outlined, and the connections between the contributing papers are highlighted.

  4. Splenectomy alters distribution and turnover but not numbers or protective capacity of de novo generated memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Marie eKim

    2014-11-01

    Full Text Available The spleen is a highly compartmentalized lymphoid organ that allows for efficient antigen presentation and activation of immune responses. Additionally, the spleen itself functions to remove senescent red blood cells, filter bacteria, and sequester platelets. Splenectomy, commonly performed after blunt force trauma or splenomegaly, has been shown to increase risk of certain bacterial and parasitic infections years after removal of the spleen. Although previous studies report defects in memory B cells and IgM titers in splenectomized patients, the effect of splenectomy on CD8 T cell responses and memory CD8 T cell function remains ill defined. Using TCR-transgenic P14 cells, we demonstrate that homeostatic proliferation and representation of pathogen-specific memory CD8 T cells in the blood are enhanced in splenectomized compared to sham surgery mice. Surprisingly, despite the enhanced turnover, splenectomized mice displayed no changes in total memory CD8 T cell numbers nor impaired protection against lethal dose challenge with Listeria monocytogenes. Thus, our data suggest that memory CD8 T cell maintenance and function remain intact in the absence of the spleen.

  5. Convective heat transport in stratified atmospheres at low and high Mach number

    CERN Document Server

    Anders, Evan H

    2016-01-01

    Convection in astrophysical systems is stratified and often occurs at high Rayleigh number (Ra) and low Mach number (Ma). Here we study stratified convection in the context of plane-parallel, polytropically stratified atmospheres. We hold the density stratification ($n_{\\rho}$) and Prandtl number (Pr) constant while varying Ma and Ra to determine the behavior of the Nusselt number (Nu), which quantifies the efficiency of convective heat transport. As Ra increases and $\\text{Ma} \\rightarrow 1$, a scaling of Nu $\\propto$ Ra$^{0.45}$ is observed. As Ra increases to a regime where Ma $\\geq 1$, this scaling gives way to a weaker Nu $\\propto$ Ra$^{0.19}$. In the regime of Ma $\\ll 1$, a consistent Nu $\\propto$ Ra$^{0.31}$ is retrieved, reminiscent of the Nu $\\propto$ Ra$^{2/7}$ seen in Rayleigh-B\\'{e}nard convection.

  6. High Reynolds Number Studies in the Wake of a Submarine Model

    Science.gov (United States)

    Jimenez, Juan; Reynolds, Ryan; Smits, Alexander

    2005-11-01

    Results are presented from submarine wake studies conducted in Princeton University's High Reynolds Number Test Facility (HRTF). Compressed air is used as a working fluid enabling Reynolds numbers based on length of up to 10^8, about 1/5 of full scale. Measurements at Reynolds numbers up to 3 x10^6 have been completed, and show that, for the model condition without fins, the wake mean velocity was self-similar at locations 6 and 9 diameters downstream. Also, PIV at Reynolds numbers near 10^4 showed that when the yaw angle was varied the sail-tip and sail-hull junction vortices increased in magnitude emphasizing the importance of fully understanding the flow characteristics of a maneuvering submarine.

  7. Decreased Number of Circulating Endothelial Progenitor Cells (CD133+/KDR+) in Patients with Psoriatic Arthritis.

    Science.gov (United States)

    Batycka-Baran, Aleksandra; Paprocka, Maria; Baran, Wojciech; Szepietowski, Jacek C

    2016-08-23

    Cardiovascular diseases are a major cause of mortality in patients with psoriatic arthritis (PsA), but the precise mechanism of increased cardiovascular risk is unknown. Endothelial dysfunction plays a crucial role in the development of atherosclerosis. Circulating endothelial progenitor cells (CEPCs) contribute to endothelial regeneration and their level may be affected by chronic inflammation. The aim of this study was to evaluate the number of CEPCs in patients with PsA (n = 24) compared with controls (n = 26). CEPCs were identified as CD133+/ KDR+ cells in peripheral blood, using flow cytometry. A significantly decreased number of CEPCs was observed in patients with PsA (p number of these cells was significantly, inversely correlated with the severity of skin and joint involvement (Psoriasis Area and Severity Index (PASI), DAS28) and the level of C-reactive protein. We hypothesize that the reduced number of CEPCs may indicate and contribute to the increased cardiovascular risk in patients with PsA.

  8. Abnormalities in centrosome number in human embryos and embryonic stem cells.

    Science.gov (United States)

    Gu, Yi-Fan; OuYang, Qi; Dai, Can; Lu, Chang-Fu; Lin, Ge; Gong, Fei; Lu, Guang-Xiu

    2016-05-01

    Chromosomal abnormalities are common in human embryos. Previous studies have suggested links between centrosome number and chromosome abnormalities, but information regarding abnormalities in centrosome number in human embryos is limited. We analyzed abnormalities in centrosome number in human embryos and embryonic stem cells (hESCs). Following normal fertilization, supernumerary centrosomes were present at rates of 7.3% in two-pronucleus (2PN)-stage zygotes and 6.5% in first-cleavage zygotes. Supernumerary centrosomes were also detected in 24.4% of blastomeres from 60% of embryos derived from 2PN zygotes. Conversely, in mono- (1PN) and tri-pronucleus (3PN) zygotes, the frequency of abnormal centrosome number increased substantially at first cleavage. Rates in blastomeres of Day-3 embryos, however, were about the same between embryos derived from 1PN and 2PN zygotes, whereas abnormalities in centrosome number were higher in those from 3PN zygotes. By comparison, the rate of abnormal centrosome numbers in hESCs was 1.5-11.2%. Thus, abnormalities in centrosome number existed in human zygotes and cleaved embryos-especially those resulting from aberrant fertilization-but the frequency of such abnormalities was lower in hESCs derived from these embryos. These findings identify a source of the chromosomal instability in human embryos and hESCs, and highlight new safety issues for human assisted reproductive technology. Mol. Reprod. Dev. 83: 392-404, 2016. © 2016 Wiley Periodicals, Inc.

  9. Mitochondrial DNA copy number variation as a potential predictor of renal cell carcinoma.

    Science.gov (United States)

    Elsayed, Eman T; Hashad, Mohamed M; Elgohary, Iman E

    2017-07-24

    Peripheral blood mitochondrial DNA (mtDNA) copy number alteration has been suggested as a risk factor for several types of cancer. The aim of the present study was to assess the role of peripheral blood mtDNA copy number variation as a noninvasive biomarker in the prediction and early detection of renal cell carcinoma (RCC) in a cohort of Egyptian patients. Quantitative real-time polymerase chain reaction (qPCR) was used to measure peripheral blood mtDNA copy numbers in 57 patients with newly diagnosed, early-stage localized RCC and 60 age- and sex-matched healthy individuals as a control group. Median mtDNA copy number was significantly higher in RCC cases than in controls (166 vs. 91, pcopy number was associated with an 18-fold increased risk of RCC (95% confidence interval: 5.065-63.9). On receiver operating characteristic curve analysis, it was found that mtDNA could distinguish between RCC patients and healthy controls, with 86% sensitivity, 80% specificity, 80.3% positive predictive value and 85.7% negative predictive value at a cutoff value of 108.5. Our results showed that increased peripheral blood mtDNA copy number was associated with increased risk of RCC. Therefore, RCC might be considered as part of a range of potential tumors in cases with elevated blood mtDNA copy number.

  10. Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers.

    Science.gov (United States)

    Waterstrat, Amanda; Rector, Kyle; Geiger, Hartmut; Liang, Ying

    2016-08-09

    Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis.

  11. Unsteady Numerical Simulation of Flow around 2-D Circular Cylinder for High Reynolds Numbers

    Institute of Scientific and Technical Information of China (English)

    Yanhui Ai; Dakui Feng; Hengkui Ye; Lin Li

    2013-01-01

    In this paper,2-D computational analyses were conducted for unsteady high Reynolds number flows around a smooth circular cylinder in the supercritical and upper-transition flow regimes,i.e.8.21×104<Re<l.54×106.The calculations were performed by means of solving the 2-D Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with a k-ε turbulence model.The calculated results,produced flow structure drag and lift coefficients,as well as Strouhal numbers.The findings were in good agreement with previous published data,which also supplied us with a good understanding of the flow across cylinders of different high Reynolds numbers.Meanwhile,an effective measure was presented to control the lift force on a cylinder,which points the way to decrease the vortex induced vibration of marine structure in future.

  12. Highly efficient light management for perovskite solar cells

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  13. Highly efficient light management for perovskite solar cells

    CERN Document Server

    Wang, Dong-Lin; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2015-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  14. Highly efficient light management for perovskite solar cells.

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-06

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  15. Subsurface Signature of the Internal Wave Field Radiated by Submerged High Reynolds Number Stratified Wakes

    Science.gov (United States)

    2014-05-26

    parametric subharmonic instability. 15. SUBJECT TERMS Stratified turbulent wakes, high Reynolds numbers, internal waves, nonlinear effects, harmonics, mean...beam and the potential for parametric subharmonic instability. In all these efforts, a uniform linear stratification was considered. A subset of our...found for all simulated waves. c) For sufficiently high-amplitude beams, a parametric subharmonic instability is observed after a long enough time

  16. Diagonal and off-diagonal quark number susceptibilities at high temperatures

    CERN Document Server

    Ding, H -T; Ohno, H; Petreczky, P; Schadler, H -P

    2015-01-01

    We present continuum extrapolated lattice QCD results for up to fourth order diagonal and off-diagonal quark number susceptibilities in the high temperature region of 300-700 MeV. Lattice QCD calculations are performed using 2+1 flavors of highly improved staggered quarks with nearly physical quark masses and at four different lattice spacings. Comparisons of our results with recent weak coupling perturbative calculations yield reasonably good agreements for the entire temperature range.

  17. Toward accurate high-throughput SNP genotyping in the presence of inherited copy number variation

    Directory of Open Access Journals (Sweden)

    Aldred Micheala A

    2007-07-01

    Full Text Available Abstract Background The recent discovery of widespread copy number variation in humans has forced a shift away from the assumption of two copies per locus per cell throughout the autosomal genome. In particular, a SNP site can no longer always be accurately assigned one of three genotypes in an individual. In the presence of copy number variability, the individual may theoretically harbor any number of copies of each of the two SNP alleles. Results To address this issue, we have developed a method to infer a "generalized genotype" from raw SNP microarray data. Here we apply our approach to data from 48 individuals and uncover thousands of aberrant SNPs, most in regions that were previously unreported as copy number variants. We show that our allele-specific copy numbers follow Mendelian inheritance patterns that would be obscured in the absence of SNP allele information. The interplay between duplication and point mutation in our data shed light on the relative frequencies of these events in human history, showing that at least some of the duplication events were recurrent. Conclusion This new multi-allelic view of SNPs has a complicated role in disease association studies, and further work will be necessary in order to accurately assess its importance. Software to perform generalized genotyping from SNP array data is freely available online 1.

  18. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    Science.gov (United States)

    Petersen, Ann M; Earp, Nathanial C; Redmond, Mandy E; Postlethwait, John H; von Hippel, Frank A; Buck, C Loren; Cresko, William A

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  19. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    Directory of Open Access Journals (Sweden)

    Ann M Petersen

    Full Text Available Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf. We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  20. Self-similar decay of high Reynolds number Taylor-Couette turbulence

    NARCIS (Netherlands)

    Verschoof, R.A.; Huisman, S.G.; Veen, van der R.C.A.; Sun, C.; Lohse, D.

    2016-01-01

    We study the decay of high-Reynolds-number Taylor-Couette turbulence, i.e., the turbulent flow between two coaxial rotating cylinders. To do so, the rotation of the inner cylinder (Re i =2×10 6 , the outer cylinder is at rest) is stopped within 12 s, thus fully removing the energy input to the syst

  1. Construction of thiostrepton-inducible, high-copy-number expression vectors for use in Streptomyces spp.

    NARCIS (Netherlands)

    Takano, Eriko; White, Janet; Thompson, Charles J.; Bibb, Mervyn J.

    1995-01-01

    A high-copy-number plasmid expression vector (pIJ6021) was constructed that contains a thiostrepton-inducible promoter, PtipA, from Streptomyces lividans 66. The promoter and ribosome-binding site of tipA lie immediately upstream from a multiple cloning site (MCS) which begins with a NdeI site (5'-C

  2. A comparative study of near-wall turbulence in high and low Reynolds number boundary layers

    Science.gov (United States)

    Metzger, M. M.; Klewicki, J. C.

    2001-03-01

    The present study explores the effects of Reynolds number, over three orders of magnitude, in the viscous wall region of a turbulent boundary layer. Complementary experiments were conducted both in the boundary layer wind tunnel at the University of Utah and in the atmospheric surface layer which flows over the salt flats of the Great Salt Lake Desert in western Utah. The Reynolds numbers, based on momentum deficit thickness, of the two flows were Rθ=2×103 and Rθ≈5×106, respectively. High-resolution velocity measurements were obtained from a five-element vertical rake of hot-wires spanning the buffer region. In both the low and high Rθ flows, the length of the hot-wires measured less than 6 viscous units. To facilitate reliable comparisons, both the laboratory and field experiments employed the same instrumentation and procedures. Data indicate that, even in the immediate vicinity of the surface, strong influences from low-frequency motions at high Rθ produce noticeable Reynolds number differences in the streamwise velocity and velocity gradient statistics. In particular, the peak value in the root mean square streamwise velocity profile, when normalized by viscous scales, was found to exhibit a logarithmic dependence on Reynolds number. The mean streamwise velocity profile, on the other hand, appears to be essentially independent of Reynolds number. Spectra and spatial correlation data suggest that low-frequency motions at high Reynolds number engender intensified local convection velocities which affect the structure of both the velocity and velocity gradient fields. Implications for turbulent production mechanisms and coherent motions in the buffer layer are discussed.

  3. Dynamic unified RANS-LES simulations of high Reynolds number separated flows

    Science.gov (United States)

    Mokhtarpoor, Reza; Heinz, Stefan; Stoellinger, Michael

    2016-09-01

    The development of hybrid RANS-LES methods is seen to be a very promising approach to enable efficient simulations of high Reynolds number turbulent flows involving flow separation. To contribute to further advances, we present a new, theoretically well based, dynamic hybrid RANS-LES method, referred to as DLUM. It is applied to a high Reynolds number flow involving both attached and separated flow regimes: a periodic hill flow is simulated at a Reynolds number of 37 000. Its performance is compared to pure LES, pure RANS, other hybrid RANS-LES (given by DLUM modifications), and experimental observations. It is shown that the use of this computational method offers huge cost reductions (which scale with Re/200, Re refers to the Reynolds number) of very high Reynolds number flow simulations compared to LES, it is much more accurate than RANS, and more accurate than LES, which is not fully resolved. In particular, this conclusion does also apply to the comparison of DLUM and pure LES simulations on rather coarse grids, which are often simply required to deal with simulations of very high Reynolds number flows: the DLUM provides mean velocity fields which are hardly affected by the grid, whereas LES velocity fields reveal significant shortcomings. We identified the reason for the superior performance of our new dynamic hybrid RANS-LES method compared to LES: it is the model's ability to respond to a changing resolution with adequate turbulent viscosity changes by ensuring simultaneously a physically correct turbulence length scale specification under the presence of interacting RANS and LES modes.

  4. Asymptotic of the number of cells visited by the planar Lorentz gas

    OpenAIRE

    Pene, Francoise

    2007-01-01

    We are interested in the planar Lorentz gas with finite horizon. Its recurrence comes from a criteria of Conze and Scmidt. Another way to prove its recurrence is given by Szasz and Varju. Total ergodicity follows from these results. In this paper we answer a question of Szasz about the asymptotic behaviour of the number of visited cells when the time goes to infinity. It is not more difficult to study the asymptotic of the number of obstacles hit by the particle when the time goes to infinity...

  5. Reduced number of peripheral natural killer cells in schizophrenia but not in bipolar disorder.

    Science.gov (United States)

    Karpiński, Paweł; Frydecka, Dorota; Sąsiadek, Maria M; Misiak, Błażej

    2016-05-01

    Overwhelming evidence indicates that subthreshold inflammatory state might be implicated in the pathophysiology of schizophrenia (SCZ) and bipolar disorder (BPD). It has been reported that both groups of patients might be characterized by abnormal lymphocyte counts. However, little is known about alterations in lymphocyte proportions that may differentiate SCZ and BPD patients. Therefore, in this study we investigated blood cell proportions quantified by means of microarray expression deconvolution using publicly available data from SCZ and BPD patients. We found significantly lower counts of natural killer (NK) cells in drug-naïve and medicated SCZ patients compared to healthy controls across all datasets. In one dataset from SCZ patients, there were no significant differences in the number of NK cells between acutely relapsed and remitted SCZ patients. No significant difference in the number of NK cells between BPD patients and healthy controls was observed in all datasets. Our results indicate that SCZ patients, but not BPD patients, might be characterized by reduced counts of NK cells. Future studies looking at lymphocyte counts in SCZ should combine the analysis of data obtained using computational deconvolution and flow cytometry techniques.

  6. Genomic copy number variation associated with clinical outcome in canine cutaneous mast cell tumors

    DEFF Research Database (Denmark)

    Jark, Paulo C; Mundin, Deborah B P; de Carvalho, Marcio

    2017-01-01

    from Group ST>12 and six from Group STGenomic DNA was extracted, and aCGH was performed using Agilent Canine Genome CGH Microarray 4×180 (ID-252 552 - Agilent, USA). Data analysis was carried out using Nexus program version 5.0 (Biodiscovery, USA). The group ST>12 presented 11±3.3 CNVs, while...... in DNA isolated from tumor cells by array comparative genomic hybridization (aCGH). The aim of this study was to compare copy number variations (CNVs) in cutaneous mast cell tumors of dogs that survived less than six (ST12months (ST>12) from the date of diagnosis. Ten animals were used: four...

  7. Cell biology in neuroscience: Architects in neural circuit design: glia control neuron numbers and connectivity.

    Science.gov (United States)

    Corty, Megan M; Freeman, Marc R

    2013-11-11

    Glia serve many important functions in the mature nervous system. In addition, these diverse cells have emerged as essential participants in nearly all aspects of neural development. Improved techniques to study neurons in the absence of glia, and to visualize and manipulate glia in vivo, have greatly expanded our knowledge of glial biology and neuron-glia interactions during development. Exciting studies in the last decade have begun to identify the cellular and molecular mechanisms by which glia exert control over neuronal circuit formation. Recent findings illustrate the importance of glial cells in shaping the nervous system by controlling the number and connectivity of neurons.

  8. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    Science.gov (United States)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  9. Location of tumor affects local and distant immune cell type and number.

    Science.gov (United States)

    Hensel, Jonathan A; Khattar, Vinayak; Ashton, Reading; Lee, Carnellia; Siegal, Gene P; Ponnazhagan, Selvarangan

    2017-03-01

    Tumors comprise heterogeneous populations of cells, including immune infiltrates that polarize during growth and metastasis. Our preclinical studies on breast cancer (BCa) identified functional differences in myeloid-derived suppressor cells based on tumor microenvironment (TME), prompting variations in host immune response to tumor growth, and dissemination based on tissue type. In order to understand if such variations existed among other immune cells, and if such alteration occurs in response to tumor growth at the primary site or due to bone dissemination, we characterized immune cells, examining localized growth and in the tibia. In addition, immune cells from the spleen were examined from animals of both tumor locations by flow cytometry. The study demonstrates that location of tumor, and not simply the tumor itself, has a definitive role in regulating immune effectors. Among all immune cells characterized, macrophages were decreased and myeloid dendritic cell were increased in both tumor locations. This difference was more evident in subcutaneous tumors. Additionally, spleens from mice with subcutaneous tumors contained greater increases in both macrophages and myeloid dendritic cells than in mice with bone tumors. Furthermore, in subcutaneous tumors there was an increase in CD4(+) and CD8(+) T-cell numbers, which was also observed in their spleens. These data indicate that alterations in tumor-reactive immune cells are more pronounced at the primary site, and exert a similar change at the major secondary lymphoid organ than in the bone TME. These findings could provide translational insight into designing therapeutic strategies that account for location of metastatic foci.

  10. Location of tumor affects local and distant immune cell type and number

    Science.gov (United States)

    Hensel, Jonathan A.; Khattar, Vinayak; Ashton, Reading; Lee, Carnellia; Siegal, Gene P.

    2017-01-01

    Abstract Introduction Tumors comprise heterogeneous populations of cells, including immune infiltrates that polarize during growth and metastasis. Our preclinical studies on breast cancer (BCa) identified functional differences in myeloid‐derived suppressor cells based on tumor microenvironment (TME), prompting variations in host immune response to tumor growth, and dissemination based on tissue type. Methods In order to understand if such variations existed among other immune cells, and if such alteration occurs in response to tumor growth at the primary site or due to bone dissemination, we characterized immune cells, examining localized growth and in the tibia. In addition, immune cells from the spleen were examined from animals of both tumor locations by flow cytometry. Results The study demonstrates that location of tumor, and not simply the tumor itself, has a definitive role in regulating immune effectors. Among all immune cells characterized, macrophages were decreased and myeloid dendritic cell were increased in both tumor locations. This difference was more evident in subcutaneous tumors. Additionally, spleens from mice with subcutaneous tumors contained greater increases in both macrophages and myeloid dendritic cells than in mice with bone tumors. Furthermore, in subcutaneous tumors there was an increase in CD4+ and CD8+ T‐cell numbers, which was also observed in their spleens. Conclusions These data indicate that alterations in tumor‐reactive immune cells are more pronounced at the primary site, and exert a similar change at the major secondary lymphoid organ than in the bone TME. These findings could provide translational insight into designing therapeutic strategies that account for location of metastatic foci. PMID:28250928

  11. Large scale dynamics in a turbulent compressible rotor/stator cavity flow at high Reynolds number

    Science.gov (United States)

    Lachize, C.; Verhille, G.; Le Gal, P.

    2016-08-01

    This paper reports an experimental investigation of a turbulent flow confined within a rotor/stator cavity of aspect ratio close to unity at high Reynolds number. The experiments have been driven by changing both the rotation rate of the disk and the thermodynamical properties of the working fluid. This fluid is sulfur hexafluoride (SF6) whose physical properties are adjusted by imposing the operating temperature and the absolute pressure in a pressurized vessel, especially near the critical point of SF6 reached for T c = 45.58 ◦C, P c = 37.55 bar. This original set-up allows to obtain Reynolds numbers as high as 2 × 107 together with compressibility effects as the Mach number can reach 0.5. Pressure measurements reveal that the resulting fully turbulent flow shows both a direct and an inverse cascade as observed in rotating turbulence and in accordance with Kraichnan conjecture for 2D-turbulence. The spectra are however dominated by low-frequency peaks, which are subharmonics of the rotating disk frequency, involving large scale structures at small azimuthal wavenumbers. These modes appear for a Reynolds number around 105 and experience a transition at a critical Reynolds number Re c ≈ 106. Moreover they show an unexpected nonlinear behavior that we understand with the help of a low dimensional amplitude equations.

  12. Large-eddy simulation of high-Schmidt number mass transfer in a turbulent channel flow

    Science.gov (United States)

    Calmet, Isabelle; Magnaudet, Jacques

    1997-02-01

    Mass transfer through the solid boundary of a turbulent channel flow is analyzed by means of large-eddy simulation (LES) for Schmidt numbers Sc=1, 100, and 200. For that purpose the subgrid stresses and fluxes are closed using the Dynamic Mixed Model proposed by Zang et al. [Phys. Fluids A 5, 3186 (1993)]. At each Schmidt number the mass transfer coefficient given by the LES is found to be in very good quantitative agreement with that measured in the experiments. At high Schmidt number this coefficient behaves like Sc-2/3, as predicted by standard theory and observed in most experiments. The main statistical characteristics of the fluctuating concentration field are analyzed in connection with the well-documented statistics of the turbulent motions. It is observed that concentration fluctuations have a significant intensity throughout the channel at Sc=1 while they are negligible out of the wall region at Sc=200. The maximum intensity of these fluctuations depends on both the Schmidt and Reynolds numbers and is especially influenced by the intensity of the velocity fluctuations present in the buffer layer of the concentration field. At Sc=1, strong similarities are observed between the various terms contributing to the turbulent kinetic energy budget and their counterpart in the budget of the variance of concentration fluctuations. At high Schmidt number, the latter budget is much more influenced by the small turbulent structures subsisting in the viscous sublayer. The instantaneous correlation between the spatial characteristics of the concentration field and those of the velocity field is clearly demonstrated by the presence of low- and high-concentration streaks close to the wall. The geometrical characteristics of these structures are found to be highly Sc dependent. In particular their spanwise wavelength is identical to that of the streamwise velocity streaks at Sc=1 while it is reduced by half at Sc=200. Analysis of the co-spectra between concentration and

  13. Design and installation of a high Reynolds number recirculating water tunnel

    Science.gov (United States)

    Daniel, Libin

    The High-Reynolds Number Fluid Mechanics Laboratory has recently been established at Oklahoma State University (OSU). The three primary components of the laboratory are 1) a recirculating water tunnel, 2) a multiphase pipe flow facility, and 3) a multi-scale flow visualization system. This thesis focuses on the design and fabrication of the water tunnel, which will be used for high-Reynolds number turbulent boundary layer research. Two main design criteria for the water tunnel were to achieve a momentum thickness based Reynolds number in excess of 104 and to have high optical access to the flow surfaces in the test section. This is being achieved with a 1 m. long test section and a maximum flow speed of 10 m/s. This Reynolds number was targeted to bridge the gap between typical university water tunnels (103) and the world's largest water tunnel facilities (105). The water tunnel is powered by a 150 hp motor and a 4500 gpm capacity centrifugal pump. The water tunnel is designed for a maximum operating pressure of 40 psi. This will make the facility a low cost option to perform high-Reynolds number aerodynamic and hydrodynamic tests. Improved flow imaging capability is a major advantage to liquid based fluid facilities because of the increased density for seeding and reduced field-of-view for equivalent Reynolds number. The laboratory's state-of-the-art flow visualization system can be used for time-resolved and phase averaged stereo- particle-image-velocimetry (sPIV), laser-induced-fluorescence, and high-speed imaging. Design provisions are also made to allow a multi-phase loop to share the pump and motor configuration of this water tunnel facility. The major design decisions that went into the design of the water tunnel facility are discussed. The design considerations that were taken into account for the test section, flow conditioning sections and the entire flow loop are discussed in greater detail. The final configuration and the technical drawings of the water

  14. Inhibition of Notch signaling reduces the number of surviving Dclk1+ reserve crypt epithelial stem cells following radiation injury.

    Science.gov (United States)

    Qu, Dongfeng; May, Randal; Sureban, Sripathi M; Weygant, Nathaniel; Chandrakesan, Parthasarathy; Ali, Naushad; Li, Linheng; Barrett, Terrence; Houchen, Courtney W

    2014-03-01

    We have previously reported that doublecortin-like kinase 1 (Dclk1) is a putative intestinal stem cell (ISC) marker. In this report, we evaluated the use of Dclk1 as a marker of surviving ISCs in response to treatment with high-dose total body irradiation (TBI). Both apoptotic and mitotic Dclk1(+) cells were observed 24 h post-TBI associated with a corresponding loss of intestinal crypts observed at 84 h post-TBI. Although the Notch signaling pathway plays an important role in regulating proliferation and lineage commitment within the intestine, its role in ISC function in response to severe genotoxic injury is not yet fully understood. We employed the microcolony assay to functionally assess the effects of Notch inhibition with difluorophenacetyl-l-alanyl-S-phenylglycine t-butyl ester (DAPT) on intestinal crypt stem cell survival following severe (>8 Gy) radiation injury. Following treatment with DAPT, we observed a nearly 50% reduction in the number of surviving Dclk1(+) crypt epithelial cells at 24 h after TBI and similar reduction in the number of surviving small intestinal crypts at 84 h. These data indicate that inhibition of Notch signaling decreases ISC survival following radiation injury, suggesting that the Notch signaling pathway plays an important role in ISC-mediated crypt regeneration. These results also suggest that crypt epithelial cell Dclk1 expression can be used as one potential marker to evaluate the early survival of ISCs following severe radiation injury.

  15. Increased numbers of Foxp3-positive regulatory T cells in gastritis, peptic ulcer and gastric adenocarcinoma

    Science.gov (United States)

    Cheng, Hsin-Hung; Tseng, Guan-Ying; Yang, Hsiao-Bai; Wang, Hung-Jung; Lin, Hwai-Jeng; Wang, Wen-Ching

    2012-01-01

    AIM: To determine the number of regulatory T cells (Tregs) in gastric mucosa of patients with gastritis, peptic ulcers and gastric cancer. METHODS: This study was a retrospective analysis of gastric antrum biopsy specimens from healthy controls (n = 22) and patients with gastritis (n = 30), peptic ulcer (n = 83), or gastric cancer (n = 32). Expression of CD4, CD25 and Foxp3 was determined by immunohistochemistry in three consecutive sections per sample. RESULTS: Compared with healthy controls, there was an increased number of CD25+ and Foxp3+ cells in patients with gastritis (P = 0.004 and P = 0.008), peptic ulcer (P gastritis (P gastritis and peptic ulcer groups. PMID:22228968

  16. High copy number of mitochondrial DNA predicts poor prognosis in patients with advanced stage colon cancer.

    Science.gov (United States)

    Wang, Yun; He, Shuixiang; Zhu, Xingmei; Qiao, Wei; Zhang, Juan

    2016-12-23

    The aim of this investigation was to determine whether alterations in mitochondrial DNA (mtDNA) copy number in colon cancer were associated with clinicopathological parameters and postsurgical outcome. By quantitative real-time PCR assay, the mtDNA copy number was detected in a cohort of colon cancer and matched adjacent colon tissues (n = 162). The majority of patients had higher mtDNA content in colon cancer tissues than matched adjacent colon tissues. Moreover, high mtDNA content in tumor tissues was associated with larger tumor size, higher serum CEA level, advanced TNM stage, vascular emboli, and liver metastases. Further survival curve analysis showed that high mtDNA content was related to the worst survival in patients with colon cancer at advanced TNM stage. High mtDNA content is a potential effective factor of poor prognosis in patients with advanced stage colon cancer.

  17. Two-dimensional lattice Boltzmann model for compressible flows with high Mach number

    Science.gov (United States)

    Gan, Yanbiao; Xu, Aiguo; Zhang, Guangcai; Yu, Xijun; Li, Yingjun

    2008-03-01

    In this paper we present an improved lattice Boltzmann model for compressible Navier-Stokes system with high Mach number. The model is composed of three components: (i) the discrete-velocity-model by M. Watari and M. Tsutahara [Phys. Rev. E 67 (2003) 036306], (ii) a modified Lax-Wendroff finite difference scheme where reasonable dissipation and dispersion are naturally included, (iii) artificial viscosity. The improved model is convenient to compromise the high accuracy and stability. The included dispersion term can effectively reduce the numerical oscillation at discontinuity. The added artificial viscosity helps the scheme to satisfy the von Neumann stability condition. Shock tubes and shock reflections are used to validate the new scheme. In our numerical tests the Mach numbers are successfully increased up to 20 or higher. The flexibility of the new model makes it suitable for tracking shock waves with high accuracy and for investigating nonlinear nonequilibrium complex systems.

  18. All-optical random number generation using highly nonlinear fibers by numerical simulation

    Science.gov (United States)

    Wang, Juanfen; Liang, Junqiang; Li, Pu; Yang, Lingzhen; Wang, Yuncai

    2014-06-01

    A new scheme of all-optical random number generation based on the nonlinear effects in highly nonlinear fibers (HNLF) is proposed. The scheme is comprised of ultra-wide band chaotic entropy source, all-optical sampler, all-optical comparator and all-optical exclusive-or (XOR), which are mainly realized by four-wave mixing (FWM) and cross-phase modulation (XPM) in highly nonlinear fibers. And we achieve 10 Gbit/s random numbers through numerically simulating all the processes. The entire operations are completed in the all-optical domain, which may overcome the bottleneck problem of electronic devices, and apply directly in high-speed all-optical communication network.

  19. Two-dimensional energy spectra in a high Reynolds number turbulent boundary layer

    Science.gov (United States)

    Chandran, Dileep; Baidya, Rio; Monty, Jason; Marusic, Ivan

    2016-11-01

    The current study measures the two-dimensional (2D) spectra of streamwise velocity component (u) in a high Reynolds number turbulent boundary layer for the first time. A 2D spectra shows the contribution of streamwise (λx) and spanwise (λy) length scales to the streamwise variance at a given wall height (z). 2D spectra could be a better tool to analyse spectral scaling laws as it is devoid of energy aliasing errors that could be present in one-dimensional spectra. A novel method is used to calculate the 2D spectra from the 2D correlation of u which is obtained by measuring velocity time series at various spanwise locations using hot-wire anemometry. At low Reynolds number, the shape of the 2D spectra at a constant energy level shows λy √{ zλx } behaviour at larger scales which is in agreement with the literature. However, at high Reynolds number, it is observed that the square-root relationship gradually transforms into a linear relationship (λy λx) which could be caused by the large packets of eddies whose length grows proportionately to the growth of its width. Additionally, we will show that this linear relationship observed at high Reynolds number is consistent with attached eddy predictions. The authors gratefully acknowledge the support from the Australian Research Council.

  20. Stereological estimation of total cell numbers in the human cerebral and cerebellar cortex

    OpenAIRE

    Walløe, Solveig; Pakkenberg, Bente; Fabricius, Katrine

    2014-01-01

    Our knowledge of the relationship between brain structure and cognitive function is still limited. Human brains and individual cortical areas vary considerably in size and shape. Studies of brain cell numbers have historically been based on biased methods, which did not always result in correct estimates and were often very time-consuming. Within the last 20–30 years, it has become possible to rely on more advanced and unbiased methods. These methods have provided us with information about fe...

  1. The foetal distress decreases the number of stem cells in umbilical cord blood

    OpenAIRE

    Pafumi, Carlo; PALUMBO, M A; LEANZA, V; TEODORO, M C; COCO, L; RISOLETI, E VI; VIZZINI S; Belvedere, G.; ZARBO, G

    2010-01-01

    The authors evaluated the blood volume of foetal blood remaining in the placenta after giving birth with the foetal distress and after a physiological delivery While the amount of blood collected did non differ between groups, the number of CD34 cells was grater in the physiological may be the foetal distress during labour leads to a shift of blood from the placenta to the foetal circulation compartment.

  2. Magnus effects at high angles of attack and critical Reynolds numbers

    Science.gov (United States)

    Seginer, A.; Ringel, M.

    1983-01-01

    The Magnus force and moment experienced by a yawed, spinning cylinder were studied experimentally in low speed and subsonic flows at high angles of attack and critical Reynolds numbers. Flow-field visualization aided in describing a flow model that divides the Magnus phenomenon into a subcritical region, where reverse Magnus loads are experienced, and a supercritical region where these loads are not encountered. The roles of the spin rate, angle of attack, and crossflow Reynolds number in determining the boundaries of the subcritical region and the variations of the Magnus loads were studied.

  3. A TAILORED FINITE POINT METHOD FOR THE HELMHOLTZ EQUATION WITH HIGH WAVE NUMBERS IN HETEROGENEOUS MEDIUM

    Institute of Scientific and Technical Information of China (English)

    Houde Han; Zhongyi Huang

    2008-01-01

    In this paper, we propose a tailored-finite-point method for the numerical simulation of the Helmholtz equation with high wave numbers in heterogeneous medium. Our finite point method has been tailored to some particular properties of the problem, which allows us to obtain approximate solutions with the same behaviors as that of the exact solution very naturally. Especially, when the coefficients are piecewise constant, we can get the exact solution with only one point in each subdomain. Our finite-point method has uniformly convergent rate with respect to wave number k in L2-norm.

  4. Significance of the Formal Quantum Number in the Highly Excited Vibration of the DCN Molecule

    Institute of Scientific and Technical Information of China (English)

    郑敦胜; 吴国祯

    2002-01-01

    For the eigenstates of the highly excited vibration of the simple molecule DCN with two stretching modes, a classical approach in a multi-dimensional coset phase space is employed to show that the formal quantum numbers are related to regular or 1east "irregular" trajectories, with zero or least Lyapunov exponents, and are always located in the inner regions of the phase space. This property reflects that they are the approximate constants of motion. It is also demonstrated that formal quantum numbers correspond to the significant phase space density.

  5. GPR30 decreases cardiac chymase/angiotensin II by inhibiting local mast cell number

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhuo [Department of Anesthesiology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27159-1009 (United States); Department of Cardiology, Jinan Central Hospital, Affiliated with Shandong University, 105 Jiefang Road, Jinan, 250013 (China); Wang, Hao; Lin, Marina [Department of Anesthesiology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27159-1009 (United States); Groban, Leanne, E-mail: lgroban@wakehealth.edu [Department of Anesthesiology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27159-1009 (United States); Hypertension and Vascular Disease Center, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157 (United States); Office of Women in Medicine and Science, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157 (United States)

    2015-03-27

    Chronic activation of the novel estrogen receptor GPR30 by its agonist G1 mitigates the adverse effects of estrogen (E2) loss on cardiac structure and function. Using the ovariectomized (OVX) mRen2.Lewis rat, an E2-sensitive model of diastolic dysfunction, we found that E2 status is inversely correlated with local cardiac angiotensin II (Ang II) levels, likely via Ang I/chymase-mediated production. Since chymase is released from cardiac mast cells during stress (e.g., volume/pressure overload, inflammation), we hypothesized that GPR30-related cardioprotection after E2 loss might occur through its opposing actions on cardiac mast cell proliferation and chymase production. Using real-time quantitative PCR, immunohistochemistry, and immunoblot analysis, we found mast cell number, chymase expression, and cardiac Ang II levels were significantly increased in the hearts of OVX-compared to ovary-intact mRen2.Lewis rats and the GPR30 agonist G1 (50 mg/kg/day, s.c.) administered for 2 weeks limited the adverse effects of estrogen loss. In vitro studies revealed that GPR30 receptors are expressed in the RBL-2H3 mast cell line and G1 inhibits serum-induced cell proliferation in a dose-dependent manner, as determined by cell counting, BrdU incorporation assay, and Ki-67 staining. Using specific antagonists to estrogen receptors, blockage of GPR30, but not ERα or ERβ, attenuated the inhibitory effects of estrogen on BrdU incorporation in RBL-2H3 cells. Further study of the mechanism underlying the effect on cell proliferation showed that G1 inhibits cyclin-dependent kinase 1 (CDK1) mRNA and protein expression in RBL-2H3 cells in a dose-dependent manner. - Highlights: • GPR30 activation limits mast cell number in hearts from OVX mRen2.Lewis rats. • GPR30 activation decreases cardiac chymase/angiotensin II after estrogen loss. • GPR30 activation inhibits RBL-2H3 mast cell proliferation and CDK1 expression.

  6. 3 TUNNELS IN THE ENGINE RESEARCH BUILDING ERB - IN CELL CE-26 VARIABLE REYNOLDS NUMBER SUPERSONIC NO

    Science.gov (United States)

    1956-01-01

    3 TUNNELS IN THE ENGINE RESEARCH BUILDING ERB - IN CELL CE-26 VARIABLE REYNOLDS NUMBER SUPERSONIC NOZZLE - CELL CE-4 6X6 INCH MACH NUMBER 2.96 SUPERSONIC AIRPLANE - CELL 1-NW 1X1 FOOT MACH 3.12 SUPERSONIC TUNNEL

  7. Cumulative number of cell divisions as a meaningful timescale for adaptive laboratory evolution of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Dae-Hee Lee

    Full Text Available Adaptive laboratory evolution (ALE under controlled conditions has become a valuable approach for the study of the genetic and biochemical basis for microbial adaptation under a given selection pressure. Conventionally, the timescale in ALE experiments has been set in terms of number of generations. As mutations are believed to occur primarily during cell division in growing cultures, the cumulative number of cell divisions (CCD would be an alternative way to set the timescale for ALE. Here we show that in short-term ALE (up to 40-50 days, Escherichia coli, under growth rate selection pressure, was found to undergo approximately 10(11.2 total cumulative cell divisions in the population to produce a new stable growth phenotype that results from 2 to 8 mutations. Continuous exposure to a low level of the mutagen N-methyl-N'-nitro-N-nitrosoguanidine was found to accelerate this timescale and led to a superior growth rate phenotype with a much larger number of mutations as determined with whole-genome sequencing. These results would be useful for the fundamental kinetics of the ALE process in designing ALE experiments and provide a basis for its quantitative description.

  8. Nkx genes regulate heart tube extension and exert differential effects on ventricular and atrial cell number.

    Science.gov (United States)

    Targoff, Kimara L; Schell, Thomas; Yelon, Deborah

    2008-10-15

    Heart formation is a complex morphogenetic process, and perturbations in cardiac morphogenesis lead to congenital heart disease. NKX2-5 is a key causative gene associated with cardiac birth defects, presumably because of its essential roles during the early steps of cardiogenesis. Previous studies in model organisms implicate NKX2-5 homologs in numerous processes, including cardiac progenitor specification, progenitor proliferation, and chamber morphogenesis. By inhibiting function of the zebrafish NKX2-5 homologs, nkx2.5 and nkx2.7, we show that nkx genes are essential to establish the original dimensions of the linear heart tube. The nkx-deficient heart tube fails to elongate normally: its ventricular portion is atypically short and wide, and its atrial portion is disorganized and sprawling. This atrial phenotype is associated with a surplus of atrial cardiomyocytes, whereas ventricular cell number is normal at this stage. However, ventricular cell number is decreased in nkx-deficient embryos later in development, when cardiac chambers are emerging. Thus, we conclude that nkx genes regulate heart tube extension and exert differential effects on ventricular and atrial cell number. Our data suggest that morphogenetic errors could originate during early stages of heart tube assembly in patients with NKX2-5 mutations.

  9. Temperature and number evolution of cold cesium atoms inside a wall-coated glass cell

    Institute of Scientific and Technical Information of China (English)

    黄家强; 张建伟; 王时光; 王力军

    2015-01-01

    We report an experimental study on the temperature and number evolution of cold cesium atoms diffusively cooled inside a wall-coated glass cell by measuring the absorption profile of the 62S1/2 (F=4)→62P3/2(F0=5) transition line with a weak probe laser in the evolution process. We found that the temperature of the cold atoms first gradually decreases from 16 mK to 9 mK, and then rapidly increases. The number of cold atoms first declines slowly from 2.1 × 109 to 3.7 × 108 and then falls drastically. A theoretical model for the number evolution is built and includes the instantaneous temperature of the cold atoms and a fraction p, which represents the part of cold cesium atoms elastically reflected by the coated cell wall. The theory is overall in good agreement with the experimental result, and a nonzero value is obtained for the fraction p, which indicates that the cold cesium atoms are not all heated to the ambient temperature by a single collision with the coated cell wall. These results can provide helpful insight for precision measurements based on diffuse laser cooling.

  10. Effects of hypergravity on the development of cell number and asymmetry in fish brain nuclei

    Science.gov (United States)

    Anken, R. H.; Werner, K.; Rahmann, H.

    Larval cichlid fish ( Oreochromis mossambicus) siblings were subjected to 3g hypergravity (hg) and total darkness for 21 days during development and subsequently processed for conventional histology. Further siblings reared at 1g and alternating light/dark (12h:12h) conditions served as contros. Cell number counts of the visual Nucleus isthmi (Ni) versus the vestibular Nucleus magnocellularis (Nm) revealed that in experimental animals total cell number was decreased in the Ni, possibly due to retarded growth as a result of the lack of visual input whereas no effect was observed in the Nm. Calculating the percentual asymmetry in cell number (i.e., right vs. the left side of the brain), no effects of hg/darkness were seen in the Ni, whereas asymmetry was slightly increased in the Nm. Since the asymmetry of inner ear otoliths is decreased under hg, this finding may indicate efferent vestibular action of the CNS on the level of the Nm by means of a feedback mechanism.

  11. Turbulent convection experiment at high Rayleigh number to support CAP1400 IVR strategy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Li, E-mail: mali@snptrd.com [State Nuclear Hua Qing(Beijing) Nuclear Power Technology R& D Centre Co., Ltd, Building A, State Nuclear Power Research Institute, Future Science & Technology Park, Changping Dist., Beijing 102209 (China); Li, Jing, E-mail: lijing@snptrd.com [State Nuclear Hua Qing(Beijing) Nuclear Power Technology R& D Centre Co., Ltd, Building A, State Nuclear Power Research Institute, Future Science & Technology Park, Changping Dist., Beijing 102209 (China); Ji, Shui, E-mail: jishui@snptrd.com [State Nuclear Hua Qing(Beijing) Nuclear Power Technology R& D Centre Co., Ltd, Building A, State Nuclear Power Research Institute, Future Science & Technology Park, Changping Dist., Beijing 102209 (China); Chang, Huajian, E-mail: changhuajian@snptrd.com [State Nuclear Hua Qing(Beijing) Nuclear Power Technology R& D Centre Co., Ltd, Building A, State Nuclear Power Research Institute, Future Science & Technology Park, Changping Dist., Beijing 102209 (China); Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2015-10-15

    Highlights: • The facility reached high Ra number at 10{sup 12} of CAP1400 working condition. • The fitting formula Nu = 0.085 × Ra{sup 0.315} was established to calculate the heat flux in the metal layer at high Ra for the CAP1400. • The coupling method can accurately and safely predict the heat flow distribution of metal layer in high Ra number conditions. • The experiment results will predict the relationship between axial and radial heat transfer well. - Abstract: The characteristics of the heat transfer and the calculation of heat flux in metal layer are both the critical problems for in-vessel retention (IVR) strategy. Turbulent convection occurs in the metal layer when the Rayleigh number (Ra) becomes sufficient high. The Globe–Dropkin (G–D) correlation (Globe and Dropkin, 1959) and Chu–Churchill (C–C) correlation (Churchill and Chu, 1975) have been widely used to calculate the heat flux in the metal layer, where the valid range of the Ra is from 1.5 × 10{sup 5} to 6.8 × 10{sup 8} in G–D correlation and less than 10{sup 12} in C–C correlation. However, with the increase of reactor power, both the Rayleigh number and the rate of heat transfer below the bottom of metal layer of the molten pool will increase, and in this case the Rayleigh number even can reach 10{sup 11} for the China Advanced Passive Plant CAP1400. Accordingly, the G–D correlation is not suitable for the CAP1400. Therefore, our experiment purposes are to establish the appropriate correlation at high Ra for the CAP1400 and predict the axial and radial distribution of the heat transfer in the metal layer with the heat transfer behavior of metal layer experiment (HELM) facility. The experiments are divided into two parts. Each part concerns 39 runs and 47 experimental conditions. Its corresponding results are obtained at middle Prandtl number (Pr = 7 for water) and the Nusselt number is found to be proportional to Ra{sup 0.315} in the range 3.93 × 10{sup 8} < Ra < 3.57

  12. Numerical simulations of high Knudsen number gas flows and microchannel electrokinetic liquid flows

    Science.gov (United States)

    Yan, Fang

    Low pressure and microchannel gas flows are characterized by high Knudsen numbers. Liquid flows in microchannels are characterized by non-conventional driving potentials like electrokinetic forces. The main thrust of the dissertation is to investigate these two different kinds of flows in gases and liquids respectively. High Knudsen number (Kn) gas flows were characterized by 'rarified' or 'microscale' behavior. Because of significant non-continuum effect, traditional CFD techniques are often inaccurate for analyzing high Kn number gas flows. The direct simulation Monte Carlo (DSMC) method offers an alternative to traditional CFD which retains its validity in slip and transition flow regimes. To validate the DSMC code, comparisons of simulation results with theoretical analysis and experimental data are made. The DSMC method was first applied to compute low pressure, high Kn flow fields in partially heated two dimensional channels. The effects of varying pressure, inlet flow and gas transport properties (Kn, Reynolds number, Re and the Prandtl number, Pr respectively) on the wall heat transfer (Nusselt number, Nu) were examined. The DSMC method was employed to explore mixing gas flows in two dimensional microchannels. Mixing of two gas streams (H2 and O2) was considered within a microchannel. The effect of the inlet-outlet pressure difference, the pressure ratio of the incoming streams and the accommodation coefficient of the solid wall on mixing length were all examined. Parallelization of a three-dimensional DSMC code was implemented using OpenMP procedure on a shared memory multi-processor computer. The parallel code was used to simulate 3D high Kn number Couette flow and the flow characteristics are found to be very different from their continuum counterparts. A mathematical model describing electrokinetically driven mass transport phenomena in microfabricated chip devices will also be presented. The model accounts for the principal physical phenomena affecting

  13. Enumeration of high numbers of bacteria using hydrophobic grid-membrane filters.

    Science.gov (United States)

    Sharpe, A N; Michaud, G L

    1975-10-01

    Printing a wax grid on a conventional membrane filter yields a device functioning as a most probable number apparatus (MPN), used at a single dilution but with a very large number of growth compartments (e.g., 3,650). By restraining the lateral spread and confluence of colonies, the hydrophobic grid-membrane filter (HGMF) allows growth- or colony-forming units (GU) to be resolved at levels far above those which produce an uncountable lawn on a conventional membrane filter. It also eliminates the size variation of normal bacterial colonies. As a result, the HGMF can give more accurate estimates of the concentration of GU. The method by which grid-cell count observations can be used to obtain MPN estimates of the number of GUs is described, and estimates obtained using the MPN method on the HGMF are compared with those resulting from conventional colony count procedures on membrane filters. A linear relation was observed between MPNGU and the number of GUs, at levels up to 30,000 GUs, for pure cultures of bacteria and for samples of natural waters. The HGMF has great potential for reducing the labor required in quantitative microbiology, since it allows, with one filter, enumeration of microorganisms over a very large concentration range and therefore reduces the need to make dilutions.

  14. High Efficiency Polymer Solar Cells Technologies

    Institute of Scientific and Technical Information of China (English)

    Abdrhman M G; LI Hang-quan; ZHANG Li-ye; ZHOU Bing

    2006-01-01

    The conjugated polymer-based solar cell is one of the most promising devices in search of sustainable, renewable energy sources in last decade. It is the youngest field in organic solar cell research and also is certainly the fastest growing one at the moment. In addition, the key factor for polymer-based solar cells with high-efficiency is to invent new materials. Organic solar cell has attracted significant researches and commercial interest due to its low cost in fabrication and flexibility in applications. However, they suffer from relatively low conversion efficiency. The summarization of the significance and concept of high efficiency polymer solar cell technologies are presented.

  15. Robust simulations of viscoelastic flows at high Weissenberg numbers with the streamfunction/log-conformation formulation

    DEFF Research Database (Denmark)

    Comminal, Raphaël; Spangenberg, Jon; Hattel, Jesper Henri

    2015-01-01

    A new streamfunction/log-conformation formulation of incompressible viscoelastic flows is presented. The log-conformation representation guaranties the positive-definiteness of the conformation tensor and obviates the high Weissenberg number problem. The streamfunction is defined as a vector...... potential of the velocity field, and provides a pressureless formulation of the conservation laws, which automatically enforces the incompressibility. The resulting numerical method is free from velocity-pressure decoupling errors, and can achieve stable calculations for large Courant numbers, which improve...... the robustness and the efficiency of the solver. The two-dimensional flow of an Oldroyd-B fluid inside the lid-driven cavity is simulated for a large range of Weissenberg numbers. The numerical results demonstrate the second-order accuracy of our scheme, and our solutions are in good agreement with the available...

  16. High quantum-efficiency photon-number-resolving detector for photonic on-chip information processing

    CERN Document Server

    Calkins, Brice; Lita, Adriana E; Metcalf, Benjamin J; Kolthammer, W Steven; Linares, Antia Lamas; Spring, Justin B; Humphreys, Peter C; Mirin, Richard P; Gates, James C; Smith, Peter G R; Walmsley, Ian A; Gerrits, Thomas; Nam, Sae Woo

    2013-01-01

    The integrated optical circuit is a promising architecture for the realization of complex quantum optical states and information networks. One element that is required for many of these applications is a high-efficiency photon detector capable of photon-number discrimination. We present an integrated photonic system in the telecom band at 1550 nm based on UV-written silica-on-silicon waveguides and modified transition-edge sensors capable of number resolution and over 40% efficiency. Exploiting the mode transmission failure of these devices, we multiplex three detectors in series to demonstrate a combined 79% +/- 2% detection efficiency with a single pass, and 88% +/- 3% at the operating wavelength of an on-chip terminal reflection grating. Furthermore, our optical measurements clearly demonstrate no significant unexplained loss in this system due to scattering or reflections. This waveguide and detector design therefore allows the placement of number-resolving single-photon detectors of predictable efficienc...

  17. Noise-free high-efficiency photon-number-resolving detectors

    CERN Document Server

    Rosenberg, D; Miller, A J; Nam, S W; Rosenberg, Danna; Lita, Adriana E.; Miller, Aaron J.; Nam, Sae Woo

    2005-01-01

    High-efficiency optical detectors that can determine the number of photons in a pulse of monochromatic light have applications in a variety of physics studies, including post-selection-based entanglement protocols for linear optics quantum computing and experiments that simultaneously close the detection and communication loopholes of Bell's inequalities. Here we report on our demonstration of fiber-coupled, noise-free, photon-number-resolving transition-edge sensors with 88% efficiency at 1550 nm. The efficiency of these sensors could be made even higher at any wavelength in the visible and near-infrared spectrum without resulting in a higher dark-count rate or degraded photon-number resolution.

  18. On the high rank $\\pi/3$ and $2\\pi/3$-congruent number elliptic curves

    CERN Document Server

    Janfada, A S

    2011-01-01

    In this article, we try to find high rank elliptic curves in the family $E_{n,\\theta}$ defined over $\\mathbb Q$ by the equation $y^2=x^3+2snx-(r^2-s^2)n^2x$, where $0 < \\theta < \\pi$, $\\cos(\\theta) = s/r$ is rational with $0\\leq |s| number problem as a generalization of the classical congruent number problem. We consider two special cases $\\theta=\\pi/3$ and $\\theta=2\\pi/3$. Then by searching in a certain known family of $\\theta$-congruent numbers and using Mestre-Nagao sum as a sieving tool, we find some square free integers $n$ such that $E_{n, \\theta}(\\mathbb Q)$ has Mordell-Weil rank up to 7 in the first case and 6 in the second case.

  19. On the motion of non-spherical particles at high Reynolds number

    DEFF Research Database (Denmark)

    Mandø, Matthias; Rosendahl, Lasse

    2010-01-01

    This paper contains a critical review of available methodology for dealing with the motion of non-spherical particles at higher Reynolds numbers in the Eulerian- Lagrangian methodology for dispersed flow. First, an account of the various attempts to classify the various shapes and the efforts...... motion it is necessary to account for the non-coincidence between the center of pressure and center of gravity which is a direct consequence of the inertial pressure forces associated with particles at high Reynolds number flow. Extensions for non-spherical particles at higher Reynolds numbers are far...... in between and usually based on semi-heuristic approaches utilizing concepts from airfoil theory such as profile lift. Even for regular particles there seems to be a long way before a complete theory can be formulated. For irregular particles with small aspect ratio, where the secondary motion...

  20. The shock tube as a device for testing transonic airfoils at high Reynolds numbers

    Science.gov (United States)

    Cook, W. J.; Presley, L. L.; Chapman, G. T.

    1978-01-01

    A performance analysis of gas-driven shock tubes shows that transonic airfoil flows with chord Reynolds numbers in the range of 100 million can be generated behind the primary shock in a large shock tube. A study of flow over simple airfoils has been carried out at low and intermediate Reynolds numbers to assess the testing technique. Results obtained from schlieren photos and airfoil pressure measurements show that steady transonic flows similar to those observed for the airfoils in wind tunnels can be generated within the available testing time in a shock tube with either properly-contoured test section walls or a properly-designed slotted-wall test section. The study indicates that the shock tube is a useful facility for studying two-dimensional high Reynolds number transonic airfoil flows.

  1. Neutral pion number fluctuations at high multiplicity in pp-interactions at 50 GeV

    Directory of Open Access Journals (Sweden)

    Popov V. V.

    2012-12-01

    Full Text Available The results of E-190 experiment (project Thermalization with 50 GeV proton beam irradiation of SVD-2 setup are presented. MC simulation has shown the linear dependence of number of photons detected in electromagnetic calorimeter and the average number of neutral pions. Multiplicity distribution of neutral pion, N0, for total number of particles in the event, Ntot = Nch + N0, are obtained with corrections on the setup acceptance, triggering and efficiency of the event reconstruction. The scaled variance of neutral pion fluctuations, ω = D/ , versus total multiplicity is measured. The fluctuations increase at Ntot > 18. According to quantum statistics models this behavior can indicate a pion condensate formation in the high pion multiplicity system. This effect has been observed for the first time.

  2. A robust approach to the generation of high-quality random numbers

    Science.gov (United States)

    Bisadi, Zahra; Fontana, Giorgio; Moser, Enrico; Pucker, Georg; Pavesi, Lorenzo

    2016-10-01

    A random number generation approach comprising a silicon nanocrystals LED (Si-NCs LED), silicon single photon avalanche photodiode (Si SPAD) and a field-programmable gate array (FPGA) is introduced. The Si-NCs LED is the source of entropy with photon emission in the visible range detectable by silicon detectors allowing the fabrication of an all-silicon-based device. The proposed quantum random number generator (QRNG) is robust against variations of the internal and external parameters such as aging of the components, changing temperature, the ambient interferences and the silicon detector artifacts. The raw data show high quality of randomness and passed all the statistical tests in National Institute of Standards and Technology (NIST) tests suite without the application of a post-processing algorithm. The efficiency of random number generation is 4-bits per detected photon.

  3. Regularized characteristic boundary conditions for the Lattice-Boltzmann methods at high Reynolds number flows

    Science.gov (United States)

    Wissocq, Gauthier; Gourdain, Nicolas; Malaspinas, Orestis; Eyssartier, Alexandre

    2017-02-01

    This paper reports the investigations done to adapt the Characteristic Boundary Conditions (CBC) to the Lattice-Boltzmann formalism for high Reynolds number applications. Three CBC formalisms are implemented and tested in an open source LBM code: the baseline local one-dimension inviscid (BL-LODI) approach, its extension including the effects of the transverse terms (CBC-2D) and a local streamline approach in which the problem is reformulated in the incident wave framework (LS-LODI). Then all implementations of the CBC methods are tested for a variety of test cases, ranging from canonical problems (such as 2D plane and spherical waves and 2D vortices) to a 2D NACA profile at high Reynolds number (Re =105), representative of aeronautic applications. The LS-LODI approach provides the best results for pure acoustics waves (plane and spherical waves). However, it is not well suited to the outflow of a convected vortex for which the CBC-2D associated with a relaxation on density and transverse waves provides the best results. As regards numerical stability, a regularized adaptation is necessary to simulate high Reynolds number flows. The so-called regularized FD (Finite Difference) adaptation, a modified regularized approach where the off-equilibrium part of the stress tensor is computed thanks to a finite difference scheme, is the only tested adaptation that can handle the high Reynolds computation.

  4. Introducing a nano-scale crossed hot-wire for high Reynolds number measurements

    Science.gov (United States)

    Fan, Yuyang; Fu, Matthew; Hultmark, Marcus

    2016-11-01

    Hot-wire anemometry is commonly used for high Reynolds number flow measurements, mainly because of its continuous signal and high bandwidth. However, measuring two components of velocity in high Reynolds number wall-bounded flows has proven to be quite challenging with conventional crossed hot-wires, especially close to the wall, due to insufficient resolution and obstruction from the probe. The Nano-Scale Thermal Anemometry Probe (NSTAP) is a miniature hot-wire that drastically increased the spatial and temporal resolutions for single-component measurements by using a nano-scale platinum wire. Applying a novel combining method and reconfiguration of the NSTAP design, we created a sensor (x-NSTAP) that is capable of two-component velocity measurements with a sensing volume of approximately 50 × 50 × 50 μ m, providing spatial and temporal resolutions similar to the single component NSTAP. The x-NSTAP is deployed in the Superpipe facility for accurate measurements of the Reynolds stresses at very high Reynolds numbers. Supported under NSF Grant CBET-1510100 (program manager Dimitrios Papavassiliou).

  5. The Dynamics of Very High Alfvén Mach Number Shocks in Space Plasmas

    Science.gov (United States)

    Sundberg, Torbjörn; Burgess, David; Scholer, Manfred; Masters, Adam; Sulaiman, Ali H.

    2017-02-01

    Astrophysical shocks, such as planetary bow shocks or supernova remnant shocks, are often in the high or very-high Mach number regime, and the structure of such shocks is crucial for understanding particle acceleration and plasma heating, as well inherently interesting. Recent magnetic field observations at Saturn’s bow shock, for Alfvén Mach numbers greater than about 25, have provided evidence for periodic non-stationarity, although the details of the ion- and electron-scale processes remain unclear due to limited plasma data. High-resolution, multi-spacecraft data are available for the terrestrial bow shock, but here the very high Mach number regime is only attained on extremely rare occasions. Here we present magnetic field and particle data from three such quasi-perpendicular shock crossings observed by the four-spacecraft Cluster mission. Although both ion reflection and the shock profile are modulated at the upstream ion gyroperiod timescale, the dominant wave growth in the foot takes place at sub-proton length scales and is consistent with being driven by the ion Weibel instability. The observed large-scale behavior depends strongly on cross-scale coupling between ion and electron processes, with ion reflection never fully suppressed, and this suggests a model of the shock dynamics that is in conflict with previous models of non-stationarity. Thus, the observations offer insight into the conditions prevalent in many inaccessible astrophysical environments, and provide important constraints for acceleration processes at such shocks.

  6. A distortion of very-high-redshift galaxy number counts by gravitational lensing.

    Science.gov (United States)

    Wyithe, J Stuart B; Yan, Haojing; Windhorst, Rogier A; Mao, Shude

    2011-01-13

    The observed number counts of high-redshift galaxy candidates have been used to build up a statistical description of star-forming activity at redshift z ≳ 7, when galaxies reionized the Universe. Standard models predict that a high incidence of gravitational lensing will probably distort measurements of flux and number of these earliest galaxies. The raw probability of this happening has been estimated to be ∼0.5 per cent (refs 11, 12), but can be larger owing to observational biases. Here we report that gravitational lensing is likely to dominate the observed properties of galaxies with redshifts of z ≳ 12, when the instrumental limiting magnitude is expected to be brighter than the characteristic magnitude of the galaxy sample. The number counts could be modified by an order of magnitude, with most galaxies being part of multiply imaged systems, located less than 1 arcsec from brighter foreground galaxies at z ≈ 2. This lens-induced association of high-redshift and foreground galaxies has perhaps already been observed among a sample of galaxy candidates identified at z ≈ 10.6. Future surveys will need to be designed to account for a significant gravitational lensing bias in high-redshift galaxy samples.

  7. Methyl jasmonate affects morphology, number and activity of endoplasmic reticulum bodies in Raphanus sativus root cells.

    Science.gov (United States)

    Gotté, Maxime; Ghosh, Rajgourab; Bernard, Sophie; Nguema-Ona, Eric; Vicré-Gibouin, Maïté; Hara-Nishimura, Ikuko; Driouich, Azeddine

    2015-01-01

    The endoplasmic reticulum (ER) bodies are ER-derived structures that are found in Brassicaceae species and thought to play a role in defense. Here, we have investigated the occurrence, distribution and function of ER bodies in root cells of Raphanus sativus using a combination of microscopic and biochemical methods. We have also assessed the response of ER bodies to methyl jasmonate (MeJA), a phytohormone that mediates plant defense against wounding and pathogens. Our results show that (i) ER bodies do occur in different root cell types from the root cap region to the differentiation zone; (ii) they do accumulate a PYK10-like protein similar to the major marker protein of ER bodies that is involved in defense in Arabidopsis thaliana; and (iii) treatment of root cells with MeJA causes a significant increase in the number of ER bodies and the activity of β-glucosidases. More importantly, MeJA was found to induce the formation of very long ER bodies that results from the fusion of small ones, a phenomenon that has not been reported in any other study so far. These findings demonstrate that MeJA impacts the number and morphology of functional ER bodies and stimulates ER body enzyme activities, probably to participate in defense responses of radish root. They also suggest that these structures may provide a defensive system specific to root cells.

  8. Somatic copy number mosaicism in human skin revealed by induced pluripotent stem cells.

    Science.gov (United States)

    Abyzov, Alexej; Mariani, Jessica; Palejev, Dean; Zhang, Ying; Haney, Michael Seamus; Tomasini, Livia; Ferrandino, Anthony F; Rosenberg Belmaker, Lior A; Szekely, Anna; Wilson, Michael; Kocabas, Arif; Calixto, Nathaniel E; Grigorenko, Elena L; Huttner, Anita; Chawarska, Katarzyna; Weissman, Sherman; Urban, Alexander Eckehart; Gerstein, Mark; Vaccarino, Flora M

    2012-12-20

    Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) has been suspected of causing de novo copy number variation. To explore this issue, here we perform a whole-genome and transcriptome analysis of 20 human iPSC lines derived from the primary skin fibroblasts of seven individuals using next-generation sequencing. We find that, on average, an iPSC line manifests two copy number variants (CNVs) not apparent in the fibroblasts from which the iPSC was derived. Using PCR and digital droplet PCR, we show that at least 50% of those CNVs are present as low-frequency somatic genomic variants in parental fibroblasts (that is, the fibroblasts from which each corresponding human iPSC line is derived), and are manifested in iPSC lines owing to their clonal origin. Hence, reprogramming does not necessarily lead to de novo CNVs in iPSCs, because most of the line-manifested CNVs reflect somatic mosaicism in the human skin. Moreover, our findings demonstrate that clonal expansion, and iPSC lines in particular, can be used as a discovery tool to reliably detect low-frequency CNVs in the tissue of origin. Overall, we estimate that approximately 30% of the fibroblast cells have somatic CNVs in their genomes, suggesting widespread somatic mosaicism in the human body. Our study paves the way to understanding the fundamental question of the extent to which cells of the human body normally acquire structural alterations in their DNA post-zygotically.

  9. Neural androgen receptor overexpression affects cell number in the spinal nucleus of the bulbocavernosus.

    Science.gov (United States)

    Coome, L A; Swift-Gallant, A; Ramzan, F; Melhuish Beaupre, L; Brkic, T; Monks, D A

    2017-09-01

    The spinal nucleus of the bulbocavernosus (SNB) is a sexually dimorphic neuromuscular system in which the masculinisation of cell number is assumed to depend on the action of perinatal androgen in non-neural targets, whereas the masculinisation of cell size is assumed to depend primarily on the action of adult androgen on SNB cells themselves. To test these hypotheses, we characterised the SNB of Cre/loxP transgenic mice that overexpress androgen receptor (AR) throughout the body (CMV-AR) or in neural tissue only (Nestin-AR). Additionally, we examined the effects of androgen manipulation in male mutants and wild-type (WT) controls. We reproduced the expected sex differences in both motoneurone number and size, as well as the expected adult androgen dependence of SNB size. We found effects of genotype such that both Nestin-AR and CMV-AR have more SNB motoneurones than WT littermates and also that CMV-AR females have larger SNB motoneurones than Nes-AR or WT females. These results raise the possibility that AR can act in neurones and/or glia to rescue SNB motoneurones, as well as on non-neural AR to increase SNB cell size. © 2017 British Society for Neuroendocrinology.

  10. Effects of donor fibroblast cell type and transferred cloned embryo number on the efficiency of pig cloning.

    Science.gov (United States)

    Li, Zicong; Shi, Junsong; Liu, Dewu; Zhou, Rong; Zeng, Haiyu; Zhou, Xiu; Mai, Ranbiao; Zeng, Shaofen; Luo, Lvhua; Yu, Wanxian; Zhang, Shouquan; Wu, Zhenfang

    2013-02-01

    significantly higher birth rate of healthy clones (0.5009% vs. 0.3362% and 0.2433%) than that resulting from P,D,L,Y-AFBs and P,D,L,Y-FFBs. This suggests that using LW-AFBs as donor cells results in a higher cloning efficiency in pigs, compared with the other two donor fibroblast cell types. The birth rate of healthy clones was significantly improved when the number of transferred cloned embryos was increased from 150-199 to 200-450 per recipient. However, increase of the number of transferred embryos from 200-249 to 250-450 per surrogate did not change the birth rate of healthy clones. This suggests that transfer of excessive (250-450) cloned embryos to an individual surrogate is not necessary for increasing the cloning efficiency in pigs, and the relatively optimal number of reconstructed embryos transferred to individual recipient is 200-249. Furthermore, our results indicated that the numbers of total born clones, clones born alive, and clones born healthy per litter have a significantly high positive correlation with each other. The present study provides useful information for improving SCNT efficiency in pigs.

  11. Measurements of Molecular Mixing in a High Schmidt Number Rayleigh-Taylor Mixing Layer

    Energy Technology Data Exchange (ETDEWEB)

    Mueschke, N J; Schilling, O; Youngs, D L; Andrews, M

    2007-12-03

    Molecular mixing measurements are performed for a high Schmidt number (Sc {approx} 10{sup 3}), small Atwood number (A {approx} 7.5 x 10{sup -4}) buoyancy-driven turbulent Rayleigh-Taylor mixing layer in a water channel facility. Salt was added to the top stream to create the desired density difference. The degree of molecular mixing was measured as a function of time by monitoring a diffusion-limited chemical reaction between the two fluid streams. The pH of each stream was modified by the addition of acid or alkali such that a local neutralization reaction occurred as the two fluids molecularly mixed. The progress of this neutralization reaction was tracked by the addition of phenolphthalein - a pH-sensitive chemical indicator - to the acidic stream. Accurately calibrated backlit optical techniques were used to measure the average concentration of the colored chemical indicator. Comparisons of chemical product formation for pre-transitional buoyancy- and shear-driven mixing layers are given. It is also shown that experiments performed at different equivalence ratios (acid/alkali concentration) can be combined to obtain a mathematical relationship between the colored product formed and the density variance. This relationship was used to obtain high-fidelity, quantitative measures of the degree of molecular mixing which are independent of probe resolution constraints. The dependence of such mixing parameters on the Schmidt and Reynolds numbers is examined by comparing the current Sc {approx} 10{sup 3} measurements with Sc = 0.7 gas-phase and Pr = 7 liquid-phase measurements. This comparison indicates that the Schmidt number has a large effect on the bulk quantity of mixed fluid at small Reynolds numbers Re{sub h} < 10{sup 3}. At late times, all mixing parameters indicated a greater degree of molecular mixing and a decreased Schmidt number dependence. Implications for the development and quantitative assessment of turbulent transport and mixing models appropriate for

  12. Selective Rapid Eye Movement Sleep Deprivation Affects Cell Size and Number in Kitten Locus Coeruleus

    Directory of Open Access Journals (Sweden)

    James P Shaffery

    2012-05-01

    Full Text Available Cells in the locus coeruleus (LC constitute the sole source of norepinephrine (NE in the brain, and change their discharge rates according to vigilance state. In addition to its well established role in vigilance, NE affects synaptic plasticity in the postnatal critical period (CP of development. One form of CP synaptic plasticity affected by NE results from monocular occlusion, which leads to physiological and cytoarchitectural alterations in central visual areas. Selective suppression of rapid eye movement sleep (REMS in the CP kitten enhances the central effects of monocular occlusion. The mechanisms responsible for heightened cortical plasticity following REMS deprivation (REMSD remain undetermined. One possible mediator of an increase in plasticity is continuous NE outflow, which presumably persists during extended periods of REMSD. Tyrosine hydroxylase (TH is the rate-limiting enzyme in the synthesis of NE and serves as a marker for NE-producing cells. We selectively suppressed REMS in kittens for one week during the CP. The number and size of LC cells expressing immunoreactivity to tyrosine hydroxylase (TH-ir was assessed in age-matched REMS-deprived (RD-, treatment-control (TXC-, and home cage-reared (HCC animals. Sleep amounts and slow wave activity (SWA were also examined relative to baseline. Time spent in REMS during the study was lower in RD compared to TXC animals, and RD kittens increased SWA delta power in the latter half of the REMSD period. The estimated total number of TH-ir cells in LC was significantly lower in the RD- than in the TXC kittens and numerically lower than in HCC animals. The size of LC cells expressing TH-ir was greatest in the HCC group. They were significantly larger than the cells in the RD kittens. These data are consistent with a possible reduction in NE in forebrain areas, including visual cortex, caused by one week of REMSD.

  13. High rate, high reliability Li/SO2 cells

    Science.gov (United States)

    Chireau, R.

    1982-03-01

    The use of the lithium/sulfur dioxide system for aerospace applications is discussed. The high rate density in the system is compared to some primary systems: mercury zinc, silver zinc, and magnesium oxide. Estimates are provided of the storage life and shelf life of typical lithium sulfur batteries. The design of lithium cells is presented and criteria are given for improving the output of cells in order to achieve high rate and high reliability.

  14. PUFKEY: A High-Security and High-Throughput Hardware True Random Number Generator for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dongfang Li

    2015-10-01

    Full Text Available Random number generators (RNG play an important role in many sensor network systems and applications, such as those requiring secure and robust communications. In this paper, we develop a high-security and high-throughput hardware true random number generator, called PUFKEY, which consists of two kinds of physical unclonable function (PUF elements. Combined with a conditioning algorithm, true random seeds are extracted from the noise on the start-up pattern of SRAM memories. These true random seeds contain full entropy. Then, the true random seeds are used as the input for a non-deterministic hardware RNG to generate a stream of true random bits with a throughput as high as 803 Mbps. The experimental results show that the bitstream generated by the proposed PUFKEY can pass all standard national institute of standards and technology (NIST randomness tests and is resilient to a wide range of security attacks.

  15. Effects of excitation around jet preferred mode Strouhal number in high-speed jets

    Science.gov (United States)

    Kuo, Ching-Wen; Cluts, Jordan; Samimy, Mo

    2017-04-01

    It has been widely reported in the literature that the jet preferred mode Strouhal number varies over a large range of 0.2-0.6, depending upon the facility where the measurement is made as well as the measurement techniques and the location in the jet plume where the measurement is taken. This study investigates this wide variation and potential explanations for it. Active flow control is used to show that the jet is receptive to excitation over a large range of Strouhal numbers and azimuthal modes. The wide variation in the preferred mode Strouhal number is shown to be tightly linked to the evolution, spacing, and scale of the coherent flow structures, which dominate the jet shear layer's development. The low-end of the range is determined by the minimum Strouhal number at which structures begin to interact with one another in the jet plume. Below this range, structures have no significant effect on the plume's statistical properties. For Strouhal numbers at the high-end of the range, the development of coherent flow structures shifts upstream toward the nozzle exit and the structures disintegrate earlier in the jet plume. The earlier development and disintegration prevent these structures from strongly impacting the entire flowfield. The results imply that upstream perturbations in the flow present in various facilities could be responsible for the variations in the measured jet preferred mode Strouhal number. Experimental results from schlieren imaging and near- and far-field microphone measurements are used to investigate the preferred mode Strouhal number across this range.

  16. Novel Antioxidant Tripeptide "ACQ" Can Prevent UV-Induced Cell Death and Preserve the Number of Epidermal Stem Cells.

    Science.gov (United States)

    Choi, Hye-Ryung; Shin, Jung-Won; Na, Jung-Im; Nam, Kyung-Mi; Lee, Hyun-Sun; Park, Kyoung-Chan

    2015-01-01

    We found that tripeptide "ACQ: alanine-cysteine-glutamine" has significant DPPH scavenging activity compared to that of glutathione. Antioxidant effects of ACQ were tested in in vitro and in vivo models. When treated with H2O2, mock treated fibroblasts and keratinocytes showed strong staining by H2DCFA. But, ACQ showed good protective effects against hydrogen peroxide treatment. When mice were fed for 2 or 4 weeks, similar protective effects were observed. In the control group, epidermis was severely damaged by UV irradiation and apoptotic keratinocytes were observed. There were also numerous TUNEL positive cells. But in the ACQ group, epidermis became thicker and there was no sign of severe damage. Interestingly, the number of p63 cells was also higher in ACQ fed mice. To confirm the stem cell rescuing effects of ACQ, three-dimensional skin samples were constructed. Results showed that ACQ increased the expression of integrin α6 and the number of p63 positive cells. These findings showed that ACQ has good antioxidant activity and may increase stem cell activities by the regulation of integrin α6.

  17. High-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding

    Science.gov (United States)

    Lai, Hong; Orgun, Mehmet A.; Pieprzyk, Josef; Li, Jing; Luo, Mingxing; Xiao, Jinghua; Xiao, Fuyuan

    2016-08-01

    We propose an approach that achieves high-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding. In particular, we encode a key with the Chebyshev-map values corresponding to Lucas numbers and then use k-Chebyshev maps to achieve consecutive and flexible key expansion and apply the pre-shared classical information between Alice and Bob and fountain codes for privacy amplification to solve the security of the exchange of classical information via the classical channel. Consequently, our high-capacity protocol does not have the limitations imposed by orbital angular momentum and down-conversion bandwidths, and it meets the requirements for longer distances and lower error rates simultaneously.

  18. Particle-based simulations of steady-state mass transport at high P\\'eclet numbers

    CERN Document Server

    Müller, Thomas; Rajah, Luke; Cohen, Samuel I A; Yates, Emma V; Vendruscolo, Michele; Dobson, Chrisopher M; Knowles, Tuomas P J

    2015-01-01

    Conventional approaches for simulating steady-state distributions of particles under diffusive and advective transport at high P\\'eclet numbers involve solving the diffusion and advection equations in at least two dimensions. Here, we present an alternative computational strategy by combining a particle-based rather than a field-based approach with the initialisation of particles in proportion to their flux. This method allows accurate prediction of the steady state and is applicable even at high P\\'eclet numbers where traditional particle-based Monte-Carlo methods starting from randomly initialised particle distributions fail. We demonstrate that generating a flux of particles according to a predetermined density and velocity distribution at a single fixed time and initial location allows for accurate simulation of mass transport under flow. Specifically, upon initialisation in proportion to their flux, these particles are propagated individually and detected by summing up their Monte-Carlo trajectories in p...

  19. High-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding

    Science.gov (United States)

    Lai, Hong; Orgun, Mehmet A.; Pieprzyk, Josef; Li, Jing; Luo, Mingxing; Xiao, Jinghua; Xiao, Fuyuan

    2016-11-01

    We propose an approach that achieves high-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding. In particular, we encode a key with the Chebyshev-map values corresponding to Lucas numbers and then use k-Chebyshev maps to achieve consecutive and flexible key expansion and apply the pre-shared classical information between Alice and Bob and fountain codes for privacy amplification to solve the security of the exchange of classical information via the classical channel. Consequently, our high-capacity protocol does not have the limitations imposed by orbital angular momentum and down-conversion bandwidths, and it meets the requirements for longer distances and lower error rates simultaneously.

  20. I 5683 you: dialing phone numbers on cell phones activates key-concordant concepts.

    Science.gov (United States)

    Topolinski, Sascha

    2011-03-01

    When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages). In Experiment 1, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In Experiment 2, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). In Experiment 3, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word.

  1. The Simulation of High Reynolds Number Cavity Flow Based on Fractional Volumetric Lattice Boltzmann Method

    Institute of Scientific and Technical Information of China (English)

    HAN Shan-ling; ZHU Ping; LIN Zhong-qin

    2005-01-01

    The fractional volumetric lattice Boltzmann method with much better stability was used to simulate two dimensional cavity flows. Because the effective viscosity was reduced by the fraction factor, it is very effective forsimulating high Reynolds number flows. Simulations were carried out on a uniform grids system. The stream lines and the velocity profiles obtained from the simulations agree well with the standard lattice Boltzmann method simulations. Comparisons of detailed flow patterns with other studies via location of vortex centers are also satisfactory.

  2. High-Reynolds Number Viscous Flow Simulations on Embedded-Boundary CartesianGrids

    Science.gov (United States)

    2016-05-05

    term goal of this research is to develop algorithms to simulate high Reynolds number turbulent flow in complicated geometries using embedded boundary...Spalding’s formula of matching the pro- files actually computed in the flow field by the Spalart-Allmaras turbulence model. In particular the profiles ...turbu- lent viscosity to be computed, see e.g. the profiles in the bottom row of Fig. 4. The streamwise velocity and especially the turbulent viscosity

  3. Axisymmetric instability of the Poiseuille-Couette flow between concentric cylinders at high Reynolds numbers

    Science.gov (United States)

    Savenkov, I. V.

    2015-02-01

    For the pressure-driven flow in an annular channel with a wall moving in the axial direction, its linear instability with respect to axisymmetric perturbations at high Reynolds numbers is investigated within the framework of the triple-deck theory. When the gap between the cylinders is sufficiently small (as compared to the radii of the cylinders), it is shown that the perturbations can split into two wave packets, the first of which grows faster and moves at a higher velocity.

  4. Note: A high Mach number arc-driven shock tube for turbulence studies.

    Science.gov (United States)

    Titus, J B; Alexander, A B; Johnson, J A

    2013-04-01

    A high Mach arc-driven shock tube has been built at the Center for Plasma Science and Technology of Florida A&M University to study shock waves. A larger apparatus with higher voltage was built to study more stable shock waves and subsequent plasmas. Initial measurements of the apparatus conclude that the desired Mach numbers can be reached using only two-thirds the maximum possible energy that the circuit can provide.

  5. Assessing Model Assumptions for Turbulent Premixed Combustion at High Karlovitz Number

    Science.gov (United States)

    2015-09-03

    flames in the high-Karlovitz regime are characterized and modeled using Direct Numerical Simulations ( DNS ) with detailed chemistry. To enable the present...Simulations, detailed chemistry 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON...information. 15. SUBJECT TERMS. Key words or phrases identifying major concepts in the report. 16. SECURITY CLASSIFICATION. Enter security classification

  6. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-08-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (~45% in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  7. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-08-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (~45%) in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  8. A stereological analysis of NPY, POMC, Orexin, GFAP astrocyte, and Iba1 microglia cell number and volume in diet-induced obese male mice.

    Science.gov (United States)

    Lemus, Moyra B; Bayliss, Jacqueline A; Lockie, Sarah H; Santos, Vanessa V; Reichenbach, Alex; Stark, Romana; Andrews, Zane B

    2015-05-01

    The hypothalamic arcuate nucleus (ARC) contains 2 key neural populations, neuropeptide Y (NPY) and proopiomelanocortin (POMC), and, together with orexin neurons in the lateral hypothalamus, plays an integral role in energy homeostasis. However, no studies have examined total neuronal number and volume after high-fat diet (HFD) exposure using sophisticated stereology. We used design-based stereology to estimate NPY and POMC neuronal number and volume, as well as glial fibrillary acidic protein (astrocyte marker) and ionized calcium-binding adapter molecule 1 (microglia marker) cell number in the ARC; as well as orexin neurons in the lateral hypothalamus. Stereological analysis indicated approximately 8000 NPY and approximately 9000 POMC neurons in the ARC, and approximately 7500 orexin neurons in the lateral hypothalamus. HFD exposure did not affect total neuronal number in any population. However, HFD significantly increased average NPY cell volume and affected NPY and POMC cell volume distribution. HFD reduced orexin cell volume but had a bimodal effect on volume distribution with increased cells at relatively small volumes and decreased cells with relatively large volumes. ARC glial fibrillary acidic protein cells increased after 2 months on a HFD, although no significant difference after 6 months on chow diet or HFD was observed. No differences in ARC ionized calcium-binding adapter molecule 1 cell number were observed in any group. Thus, HFD affects ARC NPY or POMC neuronal cell volume number not cell number. Our results demonstrate the importance of stereology to perform robust unbiased analysis of cell number and volume. These data should be an empirical baseline reference to which future studies are compared.

  9. [Effects on blood cell numbers and cytokines of dermal application rocket kerosene in mice].

    Science.gov (United States)

    Xu, Bingxin; Wang, Jianying; Liu, Zhiguo; Li, Chenglin; Yang, Heming; Lou, Xiaotong; Li, Jianzhong; Cui, Yan

    2015-09-01

    To detect the number of cells and the level of IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-γ and IL-17 cytokines in the peripheral blood of mice exposed to rocket kerosene by skin. ICR mice were randomly divided into the normal control group and RK experimental group (400 µl×1 group). RK undiluted fuel were applied directly to the dorsal skin of the mice. In control groups were treated with sesame oil (SO). the number of blood cells were detected by automatic blood cell counter and the level of IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-γ and IL-17 cytokines in serum were detected by using flow cytometry and BD CBA Flex set kit. Compared with the normal group, WBC and LYM had a decreasing tendency 2 h and decreased significantly 6 h, 12 h and 1 d after RK exposure (P<0.05). They increased significantly 7 d after RK exposure (P<0.05). Compared with the normal group, the level of IL-6 increased significantly 2 h, 6 h, 12 h,1 d and 3 d (P<0.05). The level of TNF-α increased significantly 2h, 3d, 5d and 7d (P<0.05). The level of IL-10 increased significantly 2 h, 6 h, 3 d, 5 d and 7 d (P<0.05). The level of IFN-γ increased significantly 6 h and 3 d (P< 0.05). The level of IL-17 significantly increased 3 d, 5 d and 7d (P<0.05). RK can change the number of immune cells, causing the immune cytokine changes in mice after RK cutaneous exposure.

  10. A microfluidic chip for highly efficient cell capturing and pairing.

    Science.gov (United States)

    Cui, Shaoyan; Liu, Yaoping; Wang, Wei; Sun, Yan; Fan, Yubo

    2011-09-01

    This paper examined the feasibility of a microfluidics chip for cell capturing and pairing with a high efficiency. The chip was fabricated by the polydimethylsiloxane-based soft-lithography technique and contained two suction duct arrays set in parallel on both sides of a main microchannel. Cells were captured and paired by activating two sets of suction ducts one by one with the help of syringe pumps along with switching the cell suspensions inside the main microchannel correspondingly. The effects of suction flow rate and the dimensions of suction channels on the cell capturing and pairing efficiency were characterized. The present chip was capable of creating 1024 pairs of two different cell populations in parallel. The preliminary experimental results showed that the cell capturing efficiency was 100% and the pairing one was 88% with an optimal suction rate of 5 μl/min in the chip in the 2 μm-sized suction duct chip. The cell viability after capture inside the microfluidic device was 90.0 ± 5.3%. With this cell capturing and pairing chip, interaction between cells in a single pair mode can be studied. The ability to create cell pairs has a number of biological applications for cell fusion, cell-cell interaction studies, and cell toxicity screening.

  11. Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-05-01

    The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up to 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.

  12. Tomo-PIV Measurement of High Reynolds Number Dissipation Scale Structures

    Science.gov (United States)

    Worth, Nicholas; Nickels, Timothy

    2008-11-01

    Understanding the sources of dissipative intermittency in high Reynolds number turbulence is of significant interest, especially given the increasing affordability of LES. Coherent dissipation scale structures have been identified in numerous numerical and experiment investigations, although the latter are typically restricted by the need for accurate resolution of extremely small fast motions. These investigations are therefore often limited to one-dimensional measurements, making the study of these 3D structures and their relationship to the dissipation field difficult. The current investigation employs a very large water mixing tank (2m in diameter), which uses counter-rotating impellors to generate high Reynolds number turbulence (Rλ 1000) that is close to isotropic and homogeneous. The large scale of the tank brings the smallest scales within the resolution of Tomo-PIV, allowing full 3D realization of these structures. This unique experimental setup presents a number of challenges, which include: seeding density limitations imposed by optical attenuation through the tank; demanding light sheet intensity requirements; and the extremely high computational cost of Tomographic reconstruction for the thousands of velocity fields required for statistical analysis. Initial results will be presented along with future plans for measurement refinement.

  13. High-Energy String Scattering Amplitudes and Signless Stirling Number Identity

    Directory of Open Access Journals (Sweden)

    Jen-Chi Lee

    2012-07-01

    Full Text Available We give a complete proof of a set of identities (7 proposed recently from calculation of high-energy string scattering amplitudes. These identities allow one to extract ratios among high-energy string scattering amplitudes in the fixed angle regime from high-energy amplitudes in the Regge regime. The proof is based on a signless Stirling number identity in combinatorial theory. The results are valid for arbitrary real values L rather than only for L=0,1 proved previously. The identities for non-integer real value L were recently shown to be realized in high-energy compactified string scattering amplitudes [He S., Lee J.C., Yang Y., arXiv:1012.3158]. The parameter L is related to the mass level of an excited string state and can take non-integer values for Kaluza-Klein modes.

  14. Mitochondrial DNA copy number in peripheral blood cells declines with age and is associated with general health among elderly.

    Science.gov (United States)

    Mengel-From, Jonas; Thinggaard, Mikael; Dalgård, Christine; Kyvik, Kirsten Ohm; Christensen, Kaare; Christiansen, Lene

    2014-09-01

    The role of the mitochondria in disease, general health and aging has drawn much attention over the years. Several attempts have been made to describe how the numbers of mitochondria correlate with age, although with inconclusive results. In this study, the relative quantity of mitochondrial DNA compared to nuclear DNA, i.e. the mitochondrial DNA copy number, was measured by PCR technology and used as a proxy for the content of mitochondria copies. In 1,067 Danish twins and singletons (18-93 years of age), with the majority being elderly individuals, the estimated mean mitochondrial DNA copy number in peripheral blood cells was similar for those 18-48 years of age [mean relative mtDNA content: 61.0; 95 % CI (52.1; 69.9)], but declined by -0.54 mtDNA 95 % CI (-0.63; -0.45) every year for those older than approximately 50 years of age. However, the longitudinal, yearly decline within an individual was more than twice as steep as observed in the cross-sectional analysis [decline of mtDNA content: -1.27; 95 % CI (-1.71; -0.82)]. Subjects with low mitochondrial DNA copy number had poorer outcomes in terms of cognitive performance, physical strength, self-rated health, and higher all-cause mortality than subjects with high mitochondrial DNA copy number, also when age was controlled for. The copy number mortality association can contribute to the smaller decline in a cross-sectional sample of the population compared to the individual, longitudinal decline. This study suggests that high mitochondrial DNA copy number in blood is associated with better health and survival among elderly.

  15. Vitamin D Status in Rheumatoid Arthritis: Inflammation, Arterial Stiffness and Circulating Progenitor Cell Number.

    Directory of Open Access Journals (Sweden)

    Alberto Lo Gullo

    Full Text Available Suboptimal vitamin D status was recently acknowledged as an independent predictor of cardiovascular diseases and all-cause mortality in several clinical settings, and its serum levels are commonly reduced in Rheumatoid Arthritis (RA. Patients affected by RA present accelerated atherosclerosis and increased cardiovascular morbidity and mortality with respect to the general population. In RA, it has been reported an impairment of the number and the activity of circulating proangiogenic haematopoietic cells (PHCs, including CD34+, that may play a role in endothelial homeostasis. The purpose of the study is to investigate the association between vitamin D levels and PHCs, inflammatory markers, and arterial stiffening in patients with RA.CD34+ cells were isolated from 27 RA patients and 41 controls. Vitamin D levels, C-reactive protein (CRP, fibrinogen, pulse wave velocity (PWV, and carotid intima-media thickness (cIMT were also evaluated. CD34+ count and vitamin D levels were lower in RA patients as compared to controls, while fibrinogen, CRP, PWV and cIMT were higher in RA patients. CD34+ cell number appeared to be associated with vitamin D levels, and negatively correlated to fibrinogen and early atherosclerosis markers (PWV and cIMT; vitamin D levels appear also to be inversely associated to fibrinogen.RA patients with moderate disease activity presented with low vitamin D levels, low CD34+ cell count, increased PWV and cIMT; we found that vitamin D deficiency is associated to CD34+ cell reduction in peripheral blood, and with fibrinogen levels. This suggests that vitamin D might contribute to endothelial homeostasis in patients with RA.

  16. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    The large scale integration of renewable energy sources requires suitable energy storage systems to balance energy production and demand in the electrical grid. Bidirectional fuel cells are an attractive technology for energy storage systems due to the high energy density of fuel. Compared...... entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies...... to traditional unidirectional fuel cell, bidirectional fuel cells have increased operating voltage and current ranges. These characteristics increase the stresses on dc-dc and dc-ac converters in the electrical system, which require proper design and advanced optimization. This work is part of the PhD project...

  17. Reduced satellite cell number in situ in muscular contractures from children with cerebral palsy.

    Science.gov (United States)

    Dayanidhi, Sudarshan; Dykstra, Peter B; Lyubasyuk, Vera; McKay, Bryon R; Chambers, Henry G; Lieber, Richard L

    2015-07-01

    Satellite cells (SC) are quiescent adult muscle stem cells critical for postnatal development. Children with cerebral palsy have impaired muscular growth and develop contractures. While flow cytometry previously demonstrated a reduced SC population, extracellular matrix abnormalities may influence the cell isolation methods used, systematically isolating fewer cells from CP muscle and creating a biased result. Consequently, the purpose of this study was to use immunohistochemistry on serial muscle sections to quantify SC in situ. Serial cross-sections from human gracilis muscle biopsies (n = 11) were labeled with fluorescent antibodies for Pax7 (SC transcriptional marker), laminin (basal lamina), and 4',6-diamidino-2-phenylindole (nuclei). Fluorescence microscopy under high magnification was used to identify SC based on labeling and location. Mean SC/100 myofibers was reduced by ∼70% (p muscle growth and apparent decreased responsiveness of CP muscle to exercise. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  18. LIFT FORCE ON ROTATING SPHERE AT LOW REYNOLDS NUMBERS AND HIGH ROTATIONAL SPEEDS

    Institute of Scientific and Technical Information of China (English)

    由长福; 祁海鹰; 徐旭常

    2003-01-01

    The lift force on an isolated rotating sphere in a uniform flow was investigated by means of a three-dimensional numerical simulation for low Reynolds numbers (based on the sphere diameter) (Re < 68.4) and high dimensionless rotational speeds (Γ< 5). The Navier-Stokes equations in Cartesian coordinate system were solved using a finite volume formulation based on SIMPLE procedure. The accuracy of the numerical simulation was tested through a comparison with available theoretical, numerical and experimental results at low Reynolds numbers, and it was found that they were in close agreement under the above mentioned ranges of the Reynolds number and rotational speed. From a detailed computation of the flow field around a rotational sphere in extended ranges of the Reynolds number and rotational speed, the results show that, with increasing the rotational speed or decreasing the Reynolds number, the lift coefficient increases. An empirical equation more accurate than those obtained by previous studies was obtained to describe both effects of the rotational speed and Reynolds number on the lift force on a sphere. It was found in calculations that the drag coefficient is not significantly affected by the rotation of the sphere. The ratio of the lift force to the drag force, both of which act on a sphere in a uniform flow at the same time, was investigated. For a small spherical particle such as one of about 100μm in diameter, even if the rotational speed reaches about 106 revolutions per minute, the lift force can be neglected as compared with the drag force.

  19. Human Traumatic Brain Injury Results in Oligodendrocyte Death and Increases the Number of Oligodendrocyte Progenitor Cells.

    Science.gov (United States)

    Flygt, Johanna; Gumucio, Astrid; Ingelsson, Martin; Skoglund, Karin; Holm, Jonatan; Alafuzoff, Irina; Marklund, Niklas

    2016-06-01

    Oligodendrocyte (OL) death may contribute to white matter pathology, a common cause of network dysfunction and persistent cognitive problems in patients with traumatic brain injury (TBI). Oligodendrocyte progenitor cells (OPCs) persist throughout the adult CNS and may replace dead OLs. OL death and OPCs were analyzed by immunohistochemistry of human brain tissue samples, surgically removed due to life-threatening contusions and/or focal brain swelling at 60.6 ± 75 hours (range 4-192 hours) postinjury in 10 severe TBI patients (age 51.7 ± 18.5 years). Control brain tissue was obtained postmortem from 5 age-matched patients without CNS disorders. TUNEL and CC1 co-labeling was used to analyze apoptotic OLs, which were increased in injured brain tissue (p number of single-labeled Olig2, A2B5, NG2, and PDGFR-α-positive cells, numbers of Olig2 and A2B5 co-labeled cells were increased in TBI samples (p < 0.05); this was inversely correlated with time from injury to surgery (r = -0.8, p < 0.05). These results indicate that severe focal human TBI results in OL death and increases in OPCs postinjury, which may influence white matter function following TBI.

  20. High resolution measurement of DUF1220 domain copy number from whole genome sequence data.

    Science.gov (United States)

    Astling, David P; Heft, Ilea E; Jones, Kenneth L; Sikela, James M

    2017-08-14

    DUF1220 protein domains found primarily in Neuroblastoma BreakPoint Family (NBPF) genes show the greatest human lineage-specific increase in copy number of any coding region in the genome. There are 302 haploid copies of DUF1220 in hg38 (~160 of which are human-specific) and the majority of these can be divided into 6 different subtypes (referred to as clades). Copy number changes of specific DUF1220 clades have been associated in a dose-dependent manner with brain size variation (both evolutionarily and within the human population), cognitive aptitude, autism severity, and schizophrenia severity. However, no published methods can directly measure copies of DUF1220 with high accuracy and no method can distinguish between domains within a clade. Here we describe a novel method for measuring copies of DUF1220 domains and the NBPF genes in which they are found from whole genome sequence data. We have characterized the effect that various sequencing and alignment parameters and strategies have on the accuracy and precision of the method and defined the parameters that lead to optimal DUF1220 copy number measurement and resolution. We show that copy number estimates obtained using our read depth approach are highly correlated with those generated by ddPCR for three representative DUF1220 clades. By simulation, we demonstrate that our method provides sufficient resolution to analyze DUF1220 copy number variation at three levels: (1) DUF1220 clade copy number within individual genes and groups of genes (gene-specific clade groups) (2) genome wide DUF1220 clade copies and (3) gene copy number for DUF1220-encoding genes. To our knowledge, this is the first method to accurately measure copies of all six DUF1220 clades and the first method to provide gene specific resolution of these clades. This allows one to discriminate among the ~300 haploid human DUF1220 copies to an extent not possible with any other method. The result is a greatly enhanced capability to analyze the

  1. Mitochondrial DNA Copy Number in Peripheral Blood Cells and Risk of Developing Breast Cancer.

    Science.gov (United States)

    Lemnrau, Alina; Brook, Mark N; Fletcher, Olivia; Coulson, Penny; Tomczyk, Katarzyna; Jones, Michael; Ashworth, Alan; Swerdlow, Anthony; Orr, Nick; Garcia-Closas, Montserrat

    2015-07-15

    Increased mitochondrial DNA (mtDNA) copy number in peripheral blood cells (PBC) has been associated with the risk of developing several tumor types. Here we evaluate sources of variation of this biomarker and its association with breast cancer risk in a prospective cohort study. mtDNA copy number was measured using quantitative real-time PCR on PBC DNA samples from participants in the UK-based Breakthrough Generations Study. Temporal and assay variation was evaluated in a serial study of 91 women, with two blood samples collected approximately 6-years apart. Then, associations with breast cancer risk factors and risk were evaluated in 1,108 cases and 1,099 controls using a nested case-control design. In the serial study, mtDNA copy number showed low assay variation but large temporal variation [assay intraclass correlation coefficient (ICC), 79.3%-87.9%; temporal ICC, 38.3%). Higher mtDNA copy number was significantly associated with younger age at blood collection, being premenopausal, having an older age at menopause, and never taking HRT, both in cases and controls. Based on measurements in a single blood sample taken on average 6 years before diagnosis, higher mtDNA copy number was associated with increased breast cancer risk [OR (95% CI) for highest versus lowest quartile, 1.37 (1.02-1.83); P trend = 0.007]. In conclusion, mtDNA copy number is associated with breast cancer risk and represents a promising biomarker for risk assessment. The relatively large temporal variation should be taken into account in future analyses.

  2. EXAMINATION OF NUMBERS OF STUDENTS APPLIED TO FINE ARTS HIGH SCHOOL: A PESSIMISTIC VIEW

    Directory of Open Access Journals (Sweden)

    Cahit AKSU

    2014-11-01

    Full Text Available This study, aiming to examine student quantities applied to Fine Arts high School according to various variables was implemented with General Scanning Technic among Scanning Model and documentary scanning from Descriptive Researches. When we examine applications made to Fine Arts High School Music Departments Special Talent Exams in 2014-2015 Semester we see that less than 30 applications were made to 45% of departments having 30 students quota and because significant numbers of students didn’t apply to necessitate making exams and nearly half of these departments couldn’t get qualified and quantified students and in general in talent exams 71% of Music Departments of Fine Arts High Schools couldn’t fill their student quotas, even in the second placement special talent exam made for 2014-2015 semester 22 GSL Music Departments couldn’t reach their student qouota and when examine this year’s applications to Music Departments of Fine Arts High Schools with the last year’s rate number of applications decreased between 3-70% and schools with such decrease were equal to 60% of study sampling. This situation gives important messages and implies that: success rate of students graduating from these schools will decrease year by year and this fact will reflect to higher education institutions giving professional music education.

  3. Vortex Clusters and Their Time Evolution in High- Reynolds-Number Turbulence

    Science.gov (United States)

    Ishihara, Takashi; Uno, Atsuya; Morishita, Koji; Yokokawa, Mitsuo; Kaneda, Yukio

    2016-11-01

    Time series data (with a time interval of 4τη) obtained by high-resolution direct numerical simulations (DNSs) of forced incompressible turbulence in a periodic box, with a maximum of 122883 grid points and Taylor micro-scale Reynolds numbers Rλ up to 2300, are used to study the vortex dynamics in high Reynolds number (Re) turbulent flows. Here τη is the Kolmogorov time scale. A visualization method to handle such large-scale data was developed for this study. In the high Re turbulence generated by the DNS, we observed the dynamics of tube-like vortex clusters of various sizes, which are constructed by strong micro vortices. For example, we observed the generation of the tube-like clusters of various sizes and the processes of their merging and breakdown. We also observed layer-like vortex clusters of the order of the integral length scale forming shear layers in the high Re turbulence. This research used computational resources of the K computer and other computers of the HPCI system provided by the AICS and the ITC of Nagoya University through the HPCI System Research Project (Project ID:hp150174, hp160102).

  4. High throughput single-cell and multiple-cell micro-encapsulation.

    Science.gov (United States)

    Lagus, Todd P; Edd, Jon F

    2012-06-15

    Microfluidic encapsulation methods have been previously utilized to capture cells in picoliter-scale aqueous, monodisperse drops, providing confinement from a bulk fluid environment with applications in high throughput screening, cytometry, and mass spectrometry. We describe a method to not only encapsulate single cells, but to repeatedly capture a set number of cells (here we demonstrate one- and two-cell encapsulation) to study both isolation and the interactions between cells in groups of controlled sizes. By combining drop generation techniques with cell and particle ordering, we demonstrate controlled encapsulation of cell-sized particles for efficient, continuous encapsulation. Using an aqueous particle suspension and immiscible fluorocarbon oil, we generate aqueous drops in oil with a flow focusing nozzle. The aqueous flow rate is sufficiently high to create ordering of particles which reach the nozzle at integer multiple frequencies of the drop generation frequency, encapsulating a controlled number of cells in each drop. For representative results, 9.9 μm polystyrene particles are used as cell surrogates. This study shows a single-particle encapsulation efficiency P(k=1) of 83.7% and a double-particle encapsulation efficiency P(k=2) of 79.5% as compared to their respective Poisson efficiencies of 39.3% and 33.3%, respectively. The effect of consistent cell and particle concentration is demonstrated to be of major importance for efficient encapsulation, and dripping to jetting transitions are also addressed. Continuous media aqueous cell suspensions share a common fluid environment which allows cells to interact in parallel and also homogenizes the effects of specific cells in measurements from the media. High-throughput encapsulation of cells into picoliter-scale drops confines the samples to protect drops from cross-contamination, enable a measure of cellular diversity within samples, prevent dilution of reagents and expressed biomarkers, and amplify

  5. RESEARCHES REGARDING THE SOMATIC CELLS NUMBER FROM RAW MILK USED IN TELEMEA CHEESE TECHNOLOGICAL PROCESS

    Directory of Open Access Journals (Sweden)

    ANDRA SULER

    2013-12-01

    Full Text Available It is known that by milk production hygiene must be assure: milk microbiological security, increase the sensorial and nutritive properties, increase term of availability and consumption. The milk hygienic national strategies involved: raw material risk contamination avoiding and reducing as can is possible and the microorganisms destroying or stopping development of those. In this paper it is presented the results of somatic cells number determination by raw milk used in Telemea cheese technological processes within 5 research stations. Determinations were effectuated on 2 series with 57 samples each of them, prelevated in reception phase in summer and winter seasons.

  6. Large-scale magnetic fields at high Reynolds numbers in magnetohydrodynamic simulations.

    Science.gov (United States)

    Hotta, H; Rempel, M; Yokoyama, T

    2016-03-25

    The 11-year solar magnetic cycle shows a high degree of coherence in spite of the turbulent nature of the solar convection zone. It has been found in recent high-resolution magnetohydrodynamics simulations that the maintenance of a large-scale coherent magnetic field is difficult with small viscosity and magnetic diffusivity (≲10 (12) square centimenters per second). We reproduced previous findings that indicate a reduction of the energy in the large-scale magnetic field for lower diffusivities and demonstrate the recovery of the global-scale magnetic field using unprecedentedly high resolution. We found an efficient small-scale dynamo that suppresses small-scale flows, which mimics the properties of large diffusivity. As a result, the global-scale magnetic field is maintained even in the regime of small diffusivities-that is, large Reynolds numbers.

  7. High-Density Physical Random Number Generator Using Spin Signals in Multidomain Ferromagnetic Layer

    Directory of Open Access Journals (Sweden)

    Sungwoo Chun

    2015-01-01

    Full Text Available A high-density random number generator (RNG based on spin signals in a multidomain ferromagnetic layer in a magnetic tunnel junction (MTJ is proposed and fabricated. Unlike conventional spin-based RNGs, the proposed method does not require one to control an applied current, leading to a time delay in the system. RNG demonstrations are performed at room temperature. The randomness of the bit sequences generated by the proposed RNG is verified using the FIPS 140-2 statistical test suite provided by the NIST. The test results validate the effectiveness of the proposed RNGs. Our results suggest that we can obtain high-density, ultrafast RNGs if we can achieve high integration on the chip.

  8. Experimental investigation of late time Rayleigh-Taylor mixing at high Atwood number

    Science.gov (United States)

    Suchandra, Prasoon; Mikhaeil, Mark; Ranjan, Devesh

    2016-11-01

    Dynamics of late time, high Reynolds number (Re >20000) Rayleigh-Taylor (RT) mixing is studied using statistically steady experiments performed in a multi-layer gas tunnel. The density ratio of air and air-Helium mixture used in the present experiment results in an Atwood number 0.73. Three types of diagnostics - back-lit visualization, hot-wire anemometry and stereo particle image velocimetry (S-PIV) - are employed to obtain mixing width, velocity and density fields, with S-PIV employed for the first time for such experimental conditions. Velocity and density statistics, and their correlations (u', v', w',ρ' ,ρ'v') are presented. Calculations of probability density functions (p.d.f.s) and energy spectra are made to provide further insight into the flow physics. Energy budget of the flow is also discussed.

  9. High Throughput Pseudorandom Number Generator Based on Variable Argument Unified Hyperchaos

    Directory of Open Access Journals (Sweden)

    Kaiyu Wang

    2014-01-01

    Full Text Available This paper presents a new multioutput and high throughput pseudorandom number generator. The scheme is to make the homogenized Logistic chaotic sequence as unified hyperchaotic system parameter. So the unified hyperchaos can transfer in different chaotic systems and the output can be more complex with the changing of homogenized Logistic chaotic output. Through processing the unified hyperchaotic 4-way outputs, the output will be extended to 26 channels. In addition, the generated pseudorandom sequences have all passed NIST SP800-22 standard test and DIEHARD test. The system is designed in Verilog HDL and experimentally verified on a Xilinx Spartan 6 FPGA for a maximum throughput of 16.91 Gbits/s for the native chaotic output and 13.49 Gbits/s for the resulting pseudorandom number generators.

  10. High-speed quantum-random number generation by continuous measurement of arrival time of photons

    Science.gov (United States)

    Yan, Qiurong; Zhao, Baosheng; Hua, Zhang; Liao, Qinghong; Yang, Hao

    2015-07-01

    We demonstrate a novel high speed and multi-bit optical quantum random number generator by continuously measuring arrival time of photons with a common starting point. To obtain the unbiased and post-processing free random bits, the measured photon arrival time is converted into the sum of integral multiple of a fixed period and a phase time. Theoretical and experimental results show that the phase time is an independent and uniform random variable. A random bit extraction method by encoding the phase time is proposed. An experimental setup has been built and the unbiased random bit generation rate could reach 128 Mb/s, with random bit generation efficiency of 8 bits per detected photon. The random numbers passed all tests in the statistical test suite.

  11. Anatomy of a laminar starting thermal plume at high Prandtl number

    Science.gov (United States)

    Davaille, Anne; Limare, Angela; Touitou, Floriane; Kumagai, Ichiro; Vatteville, Judith

    2011-02-01

    We present an experimental study of the dynamics of a plume generated from a small heat source in a high Prandtl number fluid with a strongly temperature-dependent viscosity. The velocity field was determined with particle image velocimetry, while the temperature field was measured using differential interferometry and thermochromic liquid crystals. The combination of these different techniques run simultaneously allows us to identify the different stages of plume development, and to compare the positions of key-features of the velocity field (centers of rotation, maximum vorticity locations, stagnation points) respective to the plume thermal anomaly, for Prandtl numbers greater than 103. We further show that the thermal structure of the plume stem is well predicted by the constant viscosity model of Batchelor (Q J R Met Soc 80: 339-358, 1954) for viscosity ratios up to 50.

  12. Hierarchy of kissing numbers for exceptional Lie symmetry groups in high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    El Naschie, M.S. [Donghua University, Shanghai (China); Department of Physics University of Alexandria, Alexandria (Egypt)], E-mail: Chaossf@aol.com

    2008-01-15

    We are constructing a hierarchy of kissing numbers representing singular contact points of hyper-spheres in exceptional Lie symmetry groups lattice arrangement embedded in the 26 dimensional bosonic strings spacetime. That way we find a total number of points and dimensions equal to 548. This is 52 more than the order of E{sub 8}E{sub 8} of heterotic string theory and leads to the prediction of 69 elementary particles at an energy scale under 1 T. In other words, our mathematical model predicts nine more particles than what is currently experimentally known to exist in the standard model of high energy physics namely only 60. The result is thus in full agreement with all our previous theoretical findings.

  13. Inhibitory Smads and bone morphogenetic protein (BMP) modulate anterior photoreceptor cell number during planarian eye regeneration.

    Science.gov (United States)

    González-Sastre, Alejandro; Molina, Ma Dolores; Saló, Emili

    2012-01-01

    Planarians represent an excellent model to study the processes of body axis and organ re-specification during regeneration. Previous studies have revealed a conserved role for the bone morphogenetic protein (BMP) pathway and its intracellular mediators Smad1/5/8 and Smad4 in planarian dorsoventral (DV) axis re-establishment. In an attempt to gain further insight into the role of this signalling pathway in planarians, we have isolated and functionally characte-rized the inhibitory Smads (I-Smads) in Schmidtea mediterranea. Two I-Smad homologues have been identified: Smed-smad6/7-1 and Smed-smad6/7-2. Expression of smad6/7-1 was detected in the parenchyma, while smad6/7-2 was found to be ex-pressed in the central nervous system and the eyes. Neither single smad6/7-1 and smad6/7-2 nor double smad6/7-1,-2 silencing gave rise to any apparent disruption of the DV axis. However, both regenerating and intact smad6/7-2 (RNAi) planarians showed defects in eye morphogenesis and displayed small, rounded eyes that lacked the anterior subpopulation of photoreceptor cells. The number of pigment cells was also reduced in these animals at later stages of regeneration. In contrast, after low doses of Smed-bmp(RNAi), planarians regenerated larger eyes in which the anterior subpopulation of photoreceptor cells was expanded. Our results suggest that Smed-smad6/7-2 and Smed-bmp control the re-specification and maintenance of anterior photoreceptor cell number in S. mediterranea.

  14. Genomic Copy Number Dictates a Gene-Independent Cell Response to CRISPR/Cas9 Targeting | Office of Cancer Genomics

    Science.gov (United States)

    The CRISPR/Cas9 system enables genome editing and somatic cell genetic screens in mammalian cells. We performed genome-scale loss-of-function screens in 33 cancer cell lines to identify genes essential for proliferation/survival and found a strong correlation between increased gene copy number and decreased cell viability after genome editing. Within regions of copy-number gain, CRISPR/Cas9 targeting of both expressed and unexpressed genes, as well as intergenic loci, led to significantly decreased cell proliferation through induction of a G2 cell-cycle arrest.

  15. A novel high reliability CMOS SRAM cell

    Institute of Scientific and Technical Information of China (English)

    Xie Chengmin; Wang Zhongfang; Wu Longsheng; Liu Youbao

    2011-01-01

    A novel 8T single-event-upset (SEU) hardened and high static noise margin (SNM) SRAM cell is proposed.By adding one transistor paralleled with each access transistor,the drive capability of pull-up PMOS is greater than that of the conventional cell and the read access transistors are weaker than that of the conventional cell.So the hold,read SNM and critical charge increase greatly.The simulation results show that the critical charge is almost three times larger than that of the conventional 6T cell by appropriately sizing the pull-up transistors.The hold and read SNM of the new cell increase by 72% and 141.7%,respectively,compared to the 6T design,but it has a 54% area overhead and read performance penalty.According to these features,this novel cell suits high reliability applications,such as aerospace and military.

  16. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rader, D.J.; Benson, D.A.

    1995-05-01

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 {mu}m and a geometric standard deviation, {sigma}{sub g} of about 2; the CMD was found to increase and {sigma}{sub g} decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 {mu}m and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented.

  17. Time resolved, near wall PIV measurements in a high Reynolds number turbulent pipe flow

    Science.gov (United States)

    Willert, C.; Soria, J.; Stanislas, M.; Amili, O.; Bellani, G.; Cuvier, C.; Eisfelder, M.; Fiorini, T.; Graf, N.; Klinner, J.

    2016-11-01

    We report on near wall measurements of a turbulent pipe flow at shear Reynolds numbers up to Reτ = 40000 acquired in the CICLoPE facility near Bologna, Italy. With 900 mm diameter and 110 m length the facility offers a well-established turbulent flow with viscous length scales ranging from y+ = 85 μ m at Reτ = 5000 to y+ = 11 μ m at Reτ = 40000 . These length scales can be resolved with a high-speed PIV camera at image magnification near unity. For the measurement the light of a high-speed, double-pulse laser is focused into a 300 μ m thin light sheet that is introduced radially into the pipe. The light scattered by 1 μ m water-glycerol droplet seeding is observed from the side by the camera via a thin high-aspect ratio mirror with a field of view covering 20mm in wall-normal and 5mm in stream-wise direction. Statistically converged velocity profiles could be achieved using 70000 samples per sequence acquired at low laser repetition rates (100Hz). Higher sampling rates of 10 kHz provide temporally coherent data from which frequency spectra can be derived. Preliminary analysis of the data shows a well resolved inner peak that grows with increasing Reynolds number. (Project funding through EuHIT - www.euhit.org)

  18. Turbulent Flow Physics and Noise in High Reynolds Number Compressible Jets

    Science.gov (United States)

    Glauser, Mark

    2016-11-01

    In this talk I will present a snapshot of our ongoing research in high Reynolds number turbulent compressible jets. The high speed axisymmetric jet work (Mach 0.6 - 1.1) has been jointly performed with Spectral Energies LLC through AFRL support and involves 10 kHz and large window PIV data extracted from the near field jet plume, simultaneously sampled with near field pressure and far field noise. We have learned from the simultaneously sampled 10 kHz PIV near field plume and far field noise data, using POD/OID and Wavelet filtering, that there are certain "loud" velocity modes that have low averaged turbulent kinetic energy content but strongly correlate with the far field noise. From the large window PIV data obtained at Mach 1.0 and 1.1, specific POD modes were found to contain important physics of the problem. For example, the large-scale structure of the jet, shock-related fluctuations, and turbulent mixing regions of the flow were isolated through POD. By computing cross correlations, particular POD modes were found to be related to particular noise spectra. I will conclude with a description of our complex nozzle work which uses the multi-stream supersonic single expansion rectangular nozzle (SERN) recently installed in our large anechoic chamber at SU. This work is funded from both AFOSR (joint with OSU with a primary focus on flow physics) and Spectral Energies LLC (via AFRL funds with a focus on noise). Particular emphasis will be on insight gained into this complex 3D flow field (and its relationship to the far field noise) from applications of POD, Wavelet filtering and DMD to various numerical (LES) and experimental (PIV, high speed schlieren, near and far field pressure) data sets, at a core nozzle Mach number of 1.6 and a second stream Mach number of 1.0.

  19. Fetal Gender and Several Cytokines Are Associated with the Number of Fetal Cells in Maternal Blood - An Observational Study

    DEFF Research Database (Denmark)

    Schlütter, Jacob Mørup; Kirkegaard, Ida; Petersen, Olav Bjørn

    2014-01-01

    and subsequent identification. RESULTS: Participants carrying male fetuses had a higher median number of fetal cells in maternal blood than those carrying female fetuses (5 vs. 3, p = 0.04). Certain cytokines (RANTES, IL-2 and IL-5) were significantly associated with the number of fetal cells in maternal blood...

  20. Achieving High Performance Perovskite Solar Cells

    Science.gov (United States)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  1. Genetic basis for developmental homeostasis of germline stem cell niche number: a network of Tramtrack-Group nuclear BTB factors.

    Directory of Open Access Journals (Sweden)

    Mathieu Bartoletti

    Full Text Available The potential to produce new cells during adult life depends on the number of stem cell niches and the capacity of stem cells to divide, and is therefore under the control of programs ensuring developmental homeostasis. However, it remains generally unknown how the number of stem cell niches is controlled. In the insect ovary, each germline stem cell (GSC niche is embedded in a functional unit called an ovariole. The number of ovarioles, and thus the number of GSC niches, varies widely among species. In Drosophila, morphogenesis of ovarioles starts in larvae with the formation of terminal filaments (TFs, each made of 8-10 cells that pile up and sort in stacks. TFs constitute organizers of individual germline stem cell niches during larval and early pupal development. In the Drosophila melanogaster subgroup, the number of ovarioles varies interspecifically from 8 to 20. Here we show that pipsqueak, Trithorax-like, batman and the bric-à-brac (bab locus, all encoding nuclear BTB/POZ factors of the Tramtrack Group, are involved in limiting the number of ovarioles in D. melanogaster. At least two different processes are differentially perturbed by reducing the function of these genes. We found that when the bab dose is reduced, sorting of TF cells into TFs was affected such that each TF contains fewer cells and more TFs are formed. In contrast, psq mutants exhibited a greater number of TF cells per ovary, with a normal number of cells per TF, thereby leading to formation of more TFs per ovary than in the wild type. Our results indicate that two parallel genetic pathways under the control of a network of nuclear BTB factors are combined in order to negatively control the number of germline stem cell niches.

  2. Genetic basis for developmental homeostasis of germline stem cell niche number: a network of Tramtrack-Group nuclear BTB factors.

    Science.gov (United States)

    Bartoletti, Mathieu; Rubin, Thomas; Chalvet, Fabienne; Netter, Sophie; Dos Santos, Nicolas; Poisot, Emilie; Paces-Fessy, Mélanie; Cumenal, Delphine; Peronnet, Frédérique; Pret, Anne-Marie; Théodore, Laurent

    2012-01-01

    The potential to produce new cells during adult life depends on the number of stem cell niches and the capacity of stem cells to divide, and is therefore under the control of programs ensuring developmental homeostasis. However, it remains generally unknown how the number of stem cell niches is controlled. In the insect ovary, each germline stem cell (GSC) niche is embedded in a functional unit called an ovariole. The number of ovarioles, and thus the number of GSC niches, varies widely among species. In Drosophila, morphogenesis of ovarioles starts in larvae with the formation of terminal filaments (TFs), each made of 8-10 cells that pile up and sort in stacks. TFs constitute organizers of individual germline stem cell niches during larval and early pupal development. In the Drosophila melanogaster subgroup, the number of ovarioles varies interspecifically from 8 to 20. Here we show that pipsqueak, Trithorax-like, batman and the bric-à-brac (bab) locus, all encoding nuclear BTB/POZ factors of the Tramtrack Group, are involved in limiting the number of ovarioles in D. melanogaster. At least two different processes are differentially perturbed by reducing the function of these genes. We found that when the bab dose is reduced, sorting of TF cells into TFs was affected such that each TF contains fewer cells and more TFs are formed. In contrast, psq mutants exhibited a greater number of TF cells per ovary, with a normal number of cells per TF, thereby leading to formation of more TFs per ovary than in the wild type. Our results indicate that two parallel genetic pathways under the control of a network of nuclear BTB factors are combined in order to negatively control the number of germline stem cell niches.

  3. MYC and Human Telomerase Gene (TERC) Copy Number Gain in Early-stage Non–small Cell Lung Cancer

    Science.gov (United States)

    Flacco, Antonella; Ludovini, Vienna; Bianconi, Fortunato; Ragusa, Mark; Bellezza, Guido; Tofanetti, Francesca R.; Pistola, Lorenza; Siggillino, Annamaria; Vannucci, Jacopo; Cagini, Lucio; Sidoni, Angelo; Puma, Francesco; Varella-Garcia, Marileila; Crinò, Lucio

    2015-01-01

    Objectives We investigated the frequency of MYC and TERC increased gene copy number (GCN) in early-stage non–small cell lung cancer (NSCLC) and evaluated the correlation of these genomic imbalances with clinicopathologic parameters and outcome. Materials and Methods Tumor tissues were obtained from 113 resected NSCLCs. MYC and TERC GCNs were tested by fluorescence in situ hybridization (FISH) according to the University of Colorado Cancer Center (UCCC) criteria and based on the receiver operating characteristic (ROC) classification. Results When UCCC criteria were applied, 41 (36%) cases for MYC and 41 (36%) cases for TERC were considered FISH-positive. MYC and TERC concurrent FISH-positive was observed in 12 cases (11%): 2 (17%) cases with gene amplification and 10 (83%) with high polysomy. By using the ROC analysis, high MYC (mean ≥2.83 copies/cell) and TERC (mean ≥2.65 copies/cell) GCNs were observed in 60 (53.1%) cases and 58 (51.3%) cases, respectively. High TERC GCN was associated with squamous cell carcinoma (SCC) histology (P = 0.001). In univariate analysis, increased MYC GCN was associated with shorter overall survival (P = 0.032 [UCCC criteria] or P = 0.02 [ROC classification]), whereas high TERC GCN showed no association. In multivariate analysis including stage and age, high MYC GCN remained significantly associated with worse overall survival using both the UCCC criteria (P = 0.02) and the ROC classification (P = 0.008). Conclusions Our results confirm MYC as frequently amplified in early-stage NSCLC and increased MYC GCN as a strong predictor of worse survival. Increased TERC GCN does not have prognostic impact but has strong association with squamous histology. PMID:25806711

  4. Turbulent Transport at High Reynolds Numbers in an Inertial Confinement Fusion Context

    Science.gov (United States)

    2014-09-01

    of Turbulent Mixing ,” Phys. Scr ., T142, p. 014014. Fig. 4 Turbulent transport as a fraction of total transport plotted versus Re for each of four...Diffusion in Turbulent Mixing ,” Phys. Scr ., T142, p. 014062. [9] George, E., Glimm, J., Grove, J. W., Li, X.-L., Liu, Y.-J., Xu, Z.-L., and Zhao, N., 2003...ABSTRACT Turbulent Transport at High Reynolds Numbers in an Inertial Confinement Fusion Context Report Title Mix is a critical input to hydro

  5. Effects of external environment on thermocapillary convection of high prandtl number fluid

    Directory of Open Access Journals (Sweden)

    Liang Ruquan

    2016-01-01

    Full Text Available Numerical simulations have been carried out to investigate the influence of external environment on thermocapillary convection in high Prandtl number (Pr=68 liquid. The geometric model of physical problem is that the the liquid bridge surrounded by ambient air under zero or ground gravity. The interface velocity, temperature, heat flux and flow pattern in the liquid bridge are presented and discussed under different conditions by changing the external environment. The buoyancy convection produces a symmetrical vortex in the liquid bridge. The ambient air affects the distributions of the temperature velocity and heat flux on the interface by changing the thermocapillary convection.

  6. Planar multijunction high voltage solar cells

    Science.gov (United States)

    Evans, J. C., Jr.; Chai, A. T.; Goradia, C.

    1980-01-01

    Technical considerations, preliminary results, and fabrication details are discussed for a family of high-voltage planar multi-junction (PMJ) solar cells which combine the attractive features of planar cells with conventional or interdigitated back contacts and the vertical multijunction (VMJ) solar cell. The PMJ solar cell is internally divided into many voltage-generating regions, called unit cells, which are internally connected in series. The key to obtaining reasonable performance from this device was the separation of top surface field regions over each active unit cell. Using existing solar cell fabricating methods, output voltages in excess of 20 volts per linear centimeter are possible. Analysis of the new device is complex, and numerous geometries are being studied which should provide substantial benefits in both normal sunlight usage as well as with concentrators.

  7. The total number of Leydig and Sertoli cells in the testes of men across various age groups - a stereological study.

    Science.gov (United States)

    Petersen, Peter M; Seierøe, Karina; Pakkenberg, Bente

    2015-02-01

    The aim of this study was to estimate the total number of Sertoli and Leydig cells in testes from male subjects across the human lifespan, using an optimized stereological method for cell-counting. In comparison with many other organs, estimation of the total cell numbers in the testes is particularly sensitive to methodological problems. Therefore, using the optical fractionator technique and a sampling design specifically optimized for human testes, we estimated the total number of Sertoli and Leydig cells in the testes from 26 post mortem male subjects ranging in age from 16 to 80 years. The mean unilateral total number of Sertoli cells was 407 × 10(6) [range: 86 × 10(6) to 665 × 10(6) , coefficient of variation (CV) = 0.33], and the mean unilateral total number of Leydig cells was 99 × 10(6) (range: 47 × 10(6) to 245 × 10(6) , CV = 0.48). There was a significant decline in the number of Sertoli cells with age; no such decline was found for Leydig cells. Quantitative stereological analysis of post mortem tissue may help understand the influence of age or disease on the number of human testicular cells.

  8. Serial Measurements of Apoptotic Cell Numbers Provide Better Acceptance Criterion for PBMC Quality than a Single Measurement Prior to the T Cell Assay

    Directory of Open Access Journals (Sweden)

    Marie Wunsch

    2015-01-01

    Full Text Available As soon as Peripheral Blood Mononuclear Cells (PBMC are isolated from whole blood, some cells begin dying. The rate of apoptotic cell death is increased when PBMC are shipped, cryopreserved, or stored under suboptimal conditions. Apoptotic cells secrete cytokines that suppress inflammation while promoting phagocytosis. Increased numbers of apoptotic cells in PBMC may modulate T cell functions in antigen-triggered T cell assays. We assessed the effect of apoptotic bystander cells on a T cell ELISPOT assay by selectively inducing B cell apoptosis using α-CD20 mAbs. The presence of large numbers of apoptotic B cells did not affect T cell functionality. In contrast, when PBMC were stored under unfavorable conditions, leading to damage and apoptosis in the T cells as well as bystander cells, T cell functionality was greatly impaired. We observed that measuring the number of apoptotic cells before plating the PBMC into an ELISPOT assay did not reflect the extent of PBMC injury, but measuring apoptotic cell frequencies at the end of the assay did. Our data suggest that measuring the numbers of apoptotic cells prior to and post T cell assays may provide more stringent PBMC quality acceptance criteria than measurements done only prior to the start of the assay.

  9. Curling dynamics of naturally curved ribbons from high to low Reynolds numbers

    Science.gov (United States)

    Albarran Arriagada, Octavio; Massiera, Gladys; Abkarian, Manouk

    2012-11-01

    Curling deformation of thin elastic sheets appears in numerous structures in nature, such as membranes of red blood cells, epithelial tissues or green algae colonies to cite just a few examples. However, despite its ubiquity, the dynamics of curling propagation in a naturally curved material remains still poorly investigated. Here, we present a coupled experimental and theoretical study of the dynamical curling deformation of naturally curved ribbons. Using thermoplastic and metallic ribbons molded on cylinders of different radii, we tune separately the natural curvature and the geometry to study curling dynamics in air, water and in viscous oils, thus spanning a wide range of Reynolds numbers. Our theoretical and experimental approaches separate the role of elasticity, gravity and hydrodynamic dissipation from inertia and emphasize the fundamental differences between the curling of a naturally curved ribbon and a rod described by the classical Elastica. Our work shows evidence for the propagation of a single instability front, selected by a local buckling condition. We show that depending on gravity, and both the Reynolds and the Cauchy numbers, the curling speed and shape are modified by the large scale drag and the local lubrication forces. This work was supported by the French Ministry of Research, the CNRS Physics-Chemistry-Biology Interdisciplinary Pro- gram, the University Montpellier 2 Interdisciplinary Program and the Region Languedoc-Roussillon.

  10. Cell number and transfection volume dependent peptide nucleic acid antisense activity by cationic delivery methods

    DEFF Research Database (Denmark)

    Llovera Nadal, Laia; Berthold, Peter; Nielsen, Peter E

    2012-01-01

    Efficient intracellular delivery is essential for high activity of nucleic acids based therapeutics, including antisense agents. Several strategies have been developed and practically all rely on auxiliary transfection reagents such as cationic lipids, cationic polymers and cell penetrating...... peptides as complexing agents and carriers of the nucleic acids. However, uptake mechanisms remain rather poorly understood, and protocols always require optimization of transfection parameters. Considering that cationic transfection complexes bind to and thus may up-concentrate on the cell surface, we...... have now quantitatively compared the cellular activity (in the pLuc705 HeLa cell splice correction system) of PNA antisense oligomers using lipoplex delivery of cholesterol- and bisphosphonate-PNA conjugates, polyplex delivery via a PNA-polyethyleneimine conjugate and CPP delivery via a PNA...

  11. High Lithium Transference Number Electrolytes via Creation of 3-Dimensional, Charged, Nanoporous Networks from Dense Functionalized Nanoparticle Composites

    KAUST Repository

    Schaefer, Jennifer L.

    2013-03-26

    High lithium transference number, tLi+, electrolytes are desired for use in both lithium-ion and lithium metal rechargeable battery technologies. Historically, low tLi+ electrolytes have hindered device performance by allowing ion concentration gradients within the cell, leading to high internal resistances that ultimately limit cell lifetime, charging rates, and energy density. Herein, we report on the synthesis and electrochemical features of electrolytes based on nanoparticle salts designed to provide high tLi+. The salts are created by cofunctionalization of metal oxide nanoparticles with neutral organic ligands and tethered lithium salts. When dispersed in a conducting fluid such as tetraglyme, they spontaneously form a charged, nanoporous network of particles at moderate nanoparticle loadings. Modification of the tethered anion chemistry from -SO3 - to -SO3BF3 - is shown to enhance ionic conductivity of the electrolytes by facilitating ion pair dissociation. At a particle volume fraction of 0.15, the electrolyte exists as a self-supported, nanoporous gel with an optimum ionic conductivity of 10 -4 S/cm at room temperature. Galvanostatic polarization measurements on symmetric lithium metal cells containing the electrolyte show that the cell short circuit time, tSC, is inversely proportional to the square of the applied current density tSC ∼ J-2, consistent with previously predicted results for traditional polymer-in-salt electrolytes with low tLi+. Our findings suggest that electrolytes with tLi+ ≈ 1 and good ion-pair dissociation delay lithium dendrite nucleation and may lead to improved lithium plating in rechargeable batteries with metallic lithium anodes. © 2013 American Chemical Society.

  12. The correlation of reproduction-related gene expression with germ cell number in DM and PLL gilts.

    Science.gov (United States)

    Hu, Yan-Biao; Pan, Zeng-Xiang; Xu, Dan; Xu, Yin-Xue; Liu, Hong-Lin; Huang, Rui-Hua; Hu, Zhi-Gang

    2006-09-01

    In this study, the ovarian germ cell number was counted in 3-week-old Duroc x Meishan (DM, n=30) and PIC x (Landrace x Large White) (PLL, n=53) gilts, and the mRNA expression levels of four reproduction-related genes were investigated by quantitative RT-PCR. Correlation of germ cell number with the expression level of these genes was analyzed. Results showed that the germ cell number of DM was significantly higher than that of PLL gilts (PPLL gilts (P=0.269). No significant correlation existed between germ cell number and ovarian weight in the two gilt groups (R=0.335, P=0.07; R=0.119, P=0.398, respectively). A significant correlation was found between the germ cell number and expression level of ESR and IGF1R mRNA in DM gilts (R=0.648, PPLL gilts (R=0.435, PPLL gilts.

  13. Efficient high speed communications over electrical powerlines for a large number of users

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.; Tripathi, K.; Latchman, H.A. [Florida Univ., Gainesville, FL (United States). Dept. of Electrical and Computer Engineering

    2007-07-01

    Affordable broadband Internet communication is currently available for residential use via cable modem and other forms of digital subscriber lines (DSL). Powerline communication (PLC) systems were never considered seriously for communications due to their low speed and high development cost. However, due to technological advances PLCs are now spreading to local area networks and broadband over power line systems. This paper presented a newly proposed modification to the standard HomePlug 1.0 MAC protocol to make it a constant contention window-based scheme. The HomePlug 1.0 was developed based on orthogonal frequency division multiplexing (OFDM) and carrier sense multiple access with collision avoidance (CSMA/CA). It is currently the most commonly used technology of power line communications, supporting a transmission rate of up to 14 Mbps on the power line. However, the throughput performance of this original scheme becomes critical when the number of users increases. For that reason, a constant contention window based medium access control protocol algorithm of HomePlug 1.0 was proposed under the assumption that the number of active stations is known. An analytical framework based on Markov Chains was developed in order to model this modified protocol under saturation conditions. Modeling results accurately matched the actual performance of the system. This paper revealed that the performance can be improved significantly if the variables were parameterized in terms of the number of active stations. 15 refs., 1 tab., 6 figs.

  14. DNS/LES Simulations of Separated Flows at High Reynolds Numbers

    Science.gov (United States)

    Balakumar, P.

    2015-01-01

    Direct numerical simulations (DNS) and large-eddy simulations (LES) simulations of flow through a periodic channel with a constriction are performed using the dynamic Smagorinsky model at two Reynolds numbers of 2800 and 10595. The LES equations are solved using higher order compact schemes. DNS are performed for the lower Reynolds number case using a fine grid and the data are used to validate the LES results obtained with a coarse and a medium size grid. LES simulations are also performed for the higher Reynolds number case using a coarse and a medium size grid. The results are compared with an existing reference data set. The DNS and LES results agreed well with the reference data. Reynolds stresses, sub-grid eddy viscosity, and the budgets for the turbulent kinetic energy are also presented. It is found that the turbulent fluctuations in the normal and spanwise directions have the same magnitude. The turbulent kinetic energy budget shows that the production peaks near the separation point region and the production to dissipation ratio is very high on the order of five in this region. It is also observed that the production is balanced by the advection, diffusion, and dissipation in the shear layer region. The dominant term is the turbulent diffusion that is about two times the molecular dissipation.

  15. Change and Significance of Mitochondrial DNA Copy Number in Esophageal Squamous Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Zongwen Liu; Zhihua Zhao; Qiumin Zhao; Shenglei Li; Dongling Gao; Xia Pang; Kuisheng Chen; Yunhan Zhang

    2007-01-01

    OBJECTIVE To compare the differences of mitochondrial DNA (mtDNA)copies among the tissues of esophageal squamous cell carcinoma (ESCC),para-neoplastic tissue and normal mucous membrane of the esophagus,and to study the relationship between the mtDNA and the occurrence and development of esophageal squamous cell carcinoma.METHODS The mtDNA copies of 42 specimens with the ESCC,paraneoplastic mucous tissue and normal mucous membrane of the esophagus were determined using real-time fluorescence quantitative PCR.The mtDNA was analyzed using agarose gel electrophoresis.RESULTS The mtDNA from all of the tissues (42/42) from the ESCC,para-neoplastic tissue and normal esophageal mucous membranes was analyzed.showing thal there were an average mtDNA copy number of 27.1894x106 μg DNA.9.4102x106 μg DNA and 5.9347x106 μg DNA,from the respective tissues.There were significant differences (F=27.83,P<0.05) in mtDNA copy number among the three.A positive band was shown at 403 bp after qel electrophoresis of the PCR products.and the lane where the ESCC mtDNA located was rather bright.which was in accordance with the result of the real-time PCR determination.CONCLUSION An increase in the mtDNA copy number is related to the occurrence and development of ESCC.

  16. Increased number and frequency of group 3 innate lymphoid cells in nonlesional psoriatic skin

    DEFF Research Database (Denmark)

    Dyring-Andersen, B; Geisler, Carsten; Agerbeck, C

    2014-01-01

    patients with psoriasis compared with healthy skin and skin from patients with contact allergy to nickel. Furthermore, skin ILCs expressed high levels of the natural killer receptor NKG2D. NKG2D binds to stress-induced ligands, including major histocompatibility complex class I-related chain A, which we......BACKGROUND: Psoriasis is a common immune-mediated inflammatory disease that affects the skin and joints. The interleukin (IL)-23/IL-17A axis and IL-22 play key roles in the pathogenesis of psoriasis. IL-23-responsive innate lymphoid cells (ILCs) with a high capacity to produce IL-17 and/or IL-22....... METHODS: Skin biopsies were taken from healthy skin, nonlesional and lesional psoriatic skin, and nickel- and petrolatum-exposed skin from patients with contact allergy to nickel, and lymphocytes were isolated. The cells were stained and characterized by flow cytometry. Cytokine and ligand mRNA expression...

  17. Stability of High Rayleigh-Number Equilibrium Solutions of the Darcy-Oberbeck-Boussinesq Equations

    Science.gov (United States)

    Wen, Baole; Corson, Lindsey; Chini, Gregory

    2013-11-01

    There has been significant renewed interest in dissolution-driven convection in porous layers owing to the potential impact of this process on carbon dioxide storage in terrestrial aquifers. In this talk, we present some numerically-exact equilibrium solutions to the porous medium convection problem in small laterally-periodic domains at high Rayleigh number Ra . The ``uni-cellular'' equilibrium solutions first found by Corson and Chini (2011) by solving the steady Darcy-Oberbeck-Boussinesq equations are recovered and, in the interior (i.e. away from upper and lower boundary layers), are shown to have the same horizontal-mean structure as the ``heat-exchanger'' solutions identified by Hewitt et al. (2012). Secondary stability analysis of the steady solutions is performed, and implications for high-Ra porous medium convection are discussed. Funding from NSF Award 0928098 is gratefully acknowledged.

  18. High Reynolds Number Effects on Multi-Hole Probes and Hot Wire Anemometers

    Science.gov (United States)

    Ramachandran, N.; Smith, A.; Gerry, G.; Kauffman, W.

    1995-01-01

    The paper reports on the results from an experimental investigation of the response of multi-hole and hot wire probes at high flow Reynolds numbers (Re approx. 10(exp 6)). The limited results available in literature for 5-hole probes are restricted to Re approx. 10(exp 4). The experiment aims to investigate the probe response (in terms of dimensionless pressure ratios, characterizing pitch, and yaw angles and the total and static pressures) at high Re values and to gauge their effect on the calculated velocity vector. Hot wire calibrations were also undertaken with a parametric variation of the flow pressure, velocity and temperature. Different correction and calibration schemes are sought to be tested against the acquired data set. The data is in the analysis stage at the present time. The test provided good benchmark quality data that can be used to test future calibration and testing methods.

  19. Baryon Number, Strangeness and Electric Charge Fluctuations in QCD at High Temperature

    CERN Document Server

    Cheng, M; Jung, C; Karsch, F; Kaczmarek, O; Laermann, E; Mawhinney, R D; Miao, C; Petreczky, P; Schmidt, C; Söldner, W

    2008-01-01

    We analyze baryon number, strangeness and electric charge fluctuations as well as their correlations in QCD at high temperature. We present results obtained from lattice calculations performed with an improved staggered fermion action (p4-action) at two values of the lattice cut-off with almost physical up and down quark masses and a physical value for the strange quark mass. We compare these results, with an ideal quark gas at high temperature and a hadron resonance gas model at low temperature. We find that fluctuations and correlations are well described by the former already for temperatures about 1.5 times the transition temperature. At low temperature qualitative features of the lattice results are well described by a hadron resonance gas model. Higher order cumulants, which become increasingly sensitive to the light pions, however show deviations from a resonance gas in the vicinity of the transition temperature.

  20. Electron acceleration in a nonrelativistic shock with very high Alfv\\'en Mach number

    CERN Document Server

    Matsumoto, Y; Hoshino, M

    2013-01-01

    Electron acceleration associated with various plasma kinetic instabilities in a nonrelativistic, very-high-Alfv\\'en Mach-number ($M_A \\sim 45$) shock is revealed by means of a two-dimensional fully kinetic PIC simulation. Electromagnetic (ion Weibel) and electrostatic (ion-acoustic and Buneman) instabilities are strongly activated at the same time in different regions of the two-dimensional shock structure. Relativistic electrons are quickly produced predominantly by the shock surfing mechanism with the Buneman instability at the leading edge of the foot. The energy spectrum has a high-energy tail exceeding the upstream ion kinetic energy accompanying the main thermal population. This gives a favorable condition for the ion acoustic instability at the shock front, which in turn results in additional energization. The large-amplitude ion Weibel instability generates current sheets in the foot, implying another dissipation mechanism via magnetic reconnection in a three-dimensional shock structure in the very-hi...

  1. Dexamethasone Regulates Macrophage and Cd4+Cd25+ Cell Numbers in the Chicken Spleen

    Directory of Open Access Journals (Sweden)

    AS Calefi

    2016-03-01

    Full Text Available Abstract Dexamethasone (DEX is a corticoid hormone that is experimentally used to mimic the effects of increased levels of endogenous corticosterone observed during the stress response. Currently, stress is considered one of the major predisposing factors for diseases in the poultry industry. The aim of this study was to analyze the effects of DEX and/or of a 20-fold coccidial vaccine dose on leukocyte phenotypes in the spleen and cecal tonsils of chickens. Twenty specific-pathogen-free (SPF Leghorn chickens were divided into four groups: a non-treated group (NT, a DEX-treated group (Dex, a vaccinated group (V and a DEX-treated+vaccinated group (Dex+V. On experimental day (ED 42, each bird in the vaccinated groups received a anti-coccidial vaccine. DEX was injected in the birds of the Dex and Dex+V groups (0.9 mg/kg onED42 and ED45. The immunophenotyping was performed by flow cytometry analysis of splenocytes and cecal tonsils cells onED48. DEX treatment per se was unable to change CD4+CD8+, CD4+CD8+ and CD4-CD8+ populations with TCRgd or CD28 in the spleen, or macrophages and T lymphocytes in the cecal tonsils. V group birds presented higher numbers of splenic macrophages compared with those measured in the Dex+V group. The number of CD4+CD25+ cells in the spleen of birds of the V group was higher than those measured in the other experimental groups. Our data suggest that CD4+CD25+ cells and macrophages might be influenced by DEX treatment in spleen, but not in the cecal tonsils of chickens inoculated with Eimeria.

  2. The high Reynolds number flow through an axial-flow pump

    Science.gov (United States)

    Zierke, W. C.; Straka, W. A.; Taylor, P. D.

    1993-11-01

    The high Reynolds number pump (HIREP) facility at ARL Penn State has been used to perform a low-speed, large-scale experiment of the incompressible flow of water through a two-blade-row turbomachine. HIREP can involve blade chord Reynolds numbers as high as 6,000,000 and can accommodate a variety of instrumentation in both a stationary and a rotating frame of reference. The objectives of this experiment were as follows: to provide a database for comparison with three-dimensional, viscous (turbulent) flow computations; to evaluate the engineering models; and to improve our physical understanding of many of the phenomena involved in this complex flow field. The experimental results include a large quantity of data acquired throughout HIREP. A five-hole probe survey of the inlet flow 37.0 percent chord upstream of the inlet guide vane (IGV) leading edge is sufficient to give information for the inflow boundary conditions, while some static-pressure information is available to help establish an outflow boundary condition.

  3. Specularly reflected He sup 2+ at high Mach number quasi-parallel shocks

    Energy Technology Data Exchange (ETDEWEB)

    Fuselier, S.A.; Lennartsson, O.W. (Lockheed Palo Alto Research Lab., CA (United States)); Thomsen, M.F. (Los Alamos National Lab., NM (United States)); Russell, C.T. (Univ. of California, Los Angeles (United States))

    1990-04-01

    Upstream from the Earth's quasi-parallel bow shock, the Lockheed Plasma Composition Experiment on ISEE 1 often observes two types of suprathermal He{sup 2+} distributions. Always present to some degree is an energetic (several keV/eto 17.4 keV/e, the maximum energy of the detector) diffuse He{sup 2+} distribution. Sometimes, apparently when the Alfven Mach number, M{sub A}, is high enough and the spacecraft is near the shock (within a few minutes of a crossing), a second type of suprathermal He{sup 2+} distribution is also observed. This nongyrotropic, gyrating He{sup 2+} distribution has velocity components parallel and perpendicular to the magnetic field that are consistent with near-specular reflection of a portion of the incident solar wind He{sup 2+} distribution off the shock. Specularly reflected and diffuse proton distributions are associated with these gyrating He{sup 2+} distributions. The presence of these gyrating He{sup 2+} distributions suggests that specular reflection is controlled primarily by magnetic forces in high Mach number quasi-parallel shocks and that these distributions may be a seed population for more energetic diffuse He{sup 2+} distributions.

  4. The effect of high frequency sound on Culicoides numbers collected with suction light traps

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2012-04-01

    Full Text Available Culicoides midges (Diptera: Ceratopogonidae, are involved in the transmission of various pathogens that cause important diseases of livestock worldwide. The use of insect repellents to reduce the attack rate of these insects on livestock could play an important role as part of an integrated control programme against diseases transmitted by these midges. The objective of this study was to determine whether high frequency sound has any repellent effect on Culicoides midges. The number of midges collected with 220 V Onderstepoort white light traps fitted with electronic mosquito repellents (EMRs, emitting 5-20 KHz multi-frequency sound waves, was compared with that of two untreated traps. Treatments were rotated in two replicates of a 4 x 4 randomised Latin square design. Although fewer midges were collected in the two traps fitted with EMRs, the average number collected over eight consecutive nights was not significantly different. The EMRs also had no influence on any of the physiological groups of Culicoides imicola Kieffer or the species composition of the Culicoides population as determined with light traps. The results indicate that high frequency sound has no repellent effect on Culicoides midges. There is therefore no evidence to support their promotion or use in the protection of animals against pathogens transmitted by Culicoides midges.

  5. Cardiovascular and Renal Effects of High Salt Diet in GDNF+/- Mice with Low Nephron Number

    Directory of Open Access Journals (Sweden)

    Julia Schlote

    2013-09-01

    Full Text Available Aims: To test the suggested association of low nephron number and later development of renal and cardiovascular disease we investigated the effects of high sodium diet in heterozygous GDNF+/- mice. Methods: Aged wild type and GDNF+/- mice were grouped together according to high sodium (HS, 4% or low sodium (LS, 0.03% diet for 4 weeks. The heart, the aorta and the kidneys were processed for morphometric and stereological evaluations and TaqMan PCR. Results: On HS GDNF+/- mice showed significantly higher drinking volume and urine production than wt and mean arterial blood pressure tended to be higher. Heart weight was higher in GDNF+/- than in wt, but the difference was only significant for LS. HS significantly increased cardiac interstitial tissue in GDNF+/-, but not in wt. On LS GDNF+/- mice had significantly larger glomeruli than wt and HS led to an additional two fold increase of glomerular area compared to LS. On electron microscopy glomerular damage after HS was seen in GDNF+/-, but not in wt. Dietary salt intake modulated renal IL-10 gene expression in GDNF+/-. Conclusion: In the setting of 30% lower nephron number HS diet favoured maladaptive changes of the kidney as well as of the cardiovascular system.

  6. Three-dimensional effects on airfoil measurements at high Reynolds numbers

    Science.gov (United States)

    Kiefer, Janik; Miller, Mark; Hultmark, Marcus; Hansen, Martin

    2016-11-01

    Blade Element Momentum codes (BEM) are widely used in the wind turbine industry to determine a turbine's operational range and its limits. Empirical two-dimensional airfoil data serve as the primary and fundamental input to the BEM code. Consequently, the results of BEM simulations are strongly dependent on the accuracy of these data. In this presentation, an experimental study is described in which airfoils of different aspect ratios were tested at identical Reynolds numbers. A high-pressure wind tunnel facility is used to achieve large Reynolds numbers of Rec = 3 ×106 , even with small chord lengths. This methodology enables testing of very high aspect ratio airfoils to characterize 3-D effects on the lift and drag data. The tests were performed over a large range of angles of attack, which is especially important for wind turbines. The effect of varying aspect ratio on the aerodynamic characteristics of the airfoil is discussed with emphasis on the outcome of a BEM simulation. The project was partially funded by NSF CBET-1435254 (program manager Dr. Gregory Rorrer).

  7. Numerical investigation of the high Reynolds number 3D flow field generated by a self-propelling manta ray

    Science.gov (United States)

    Pederzani, Jean-Noel; Haj-Hariri, Hossein

    2012-11-01

    An embedded-boundary (or cut-cell) method for complex geometry with moving boundaries is used to solve the three dimensional Navier-Stokes equation around a self-propelling manta swimming at moderately high Reynolds numbers. The motion of the ray is prescribed using a kinematic model fitted to actual biological data. The dependence of thrust production mechanism on Strouhal and Reynolds numbers is investigated. The vortex core structures are accurately plotted and a correlation between wake structures and propulsive performance is established. This insight is critical in understanding the key flow features that a bio-inspired autonomous vehicle should reproduce in order to swim efficiently. The solution method is implemented, on a block-structured Cartesian grid using a cut-cell approach enabling the code to correctly evaluate the wall shear-stress, a key feature necessary at higher Reynolds. To enhance computational efficiency, a parallel adaptive mesh refinement technique is used. The present method is validated against published experimental results. Supported by ONR MURI.

  8. Very High Efficiency Solar Cell Modules

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

    2009-01-01

    The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

  9. Effects of pegylated G-CSF on immune cell number and function in patients with gynecological malignancies

    Directory of Open Access Journals (Sweden)

    De Cristofaro Raimondo

    2010-11-01

    Full Text Available Abstract Background Pegylated granulocyte colony-stimulating factor (G-CSF; pegfilgrastim is a longer-acting form of G-CSF, whose effects on dendritic cell (DC and regulatory T cell (Treg mobilization, and on the in vivo and ex vivo release of immune modulating cytokines remain unexplored. Methods Twelve patients with gynecological cancers received carboplatin/paclitaxel chemotherapy and single-dose pegfilgrastim as prophylaxis of febrile neutropenia. Peripheral blood was collected prior to pegfilgrastim administration (day 0 and on days +7, +11 and +21, to quantify immunoregulatory cytokines and to assess type 1 DC (DC1, type 2 DC (DC2 and Treg cell mobilization. In vitro-differentiated, monocyte-derived DC were used to investigate endocytic activity, expression of DC maturation antigens and ability to activate allogeneic T-cell proliferation. Results Pegfilgrastim increased the frequency of circulating DC1 and DC2 precursors. In contrast, CD4+FoxP3+ bona fide Treg cells were unchanged compared with baseline. Serum levels of hepatocyte growth factor and interleukin (IL-12p40, but not transforming growth factor-β1 or immune suppressive kynurenines, significantly increased after pegfilgrastim administration. Interestingly, pegfilgrastim fostered in vitro monocytic secretion of IL-12p40 and IL-12p70 when compared with unconjugated G-CSF. Finally, DC populations differentiated in vitro after clinical provision of pegfilgrastim were phenotypically mature, possessed low endocytic activity, and incited a robust T-cell proliferative response. Conclusions Pegfilgrastim induced significant changes in immune cell number and function. The enhancement of monocytic IL-12 secretion portends favorable implications for pegfilgrastim administration to patients with cancer, a clinical context where the induction of immune deviation would be highly undesirable.

  10. Immune enhancing effects of Echinacea purpurea root extract by reducing regulatory T cell number and function.

    Science.gov (United States)

    Kim, Hyung-Ran; Oh, Sei-Kwan; Lim, Woosung; Lee, Hyeon Kook; Moon, Byung-In; Seoh, Ju-Young

    2014-04-01

    Echinacea purpurea preparations (EPs) have been traditionally used for the treatment of various infections and also for wound healing. Accumulating evidence suggests their immunostimulatory effects. Regulatory T cells (Tregs) are known to play a key role in immune regulation in vivo. However, there have been no reports so far on the effects of EP on the frequency or function of Tregs in vivo. Therefore, in the present study, we investigated the quantitative and functional changes in Tregs by in vivo administration with EP. The frequencies of CD4+FoxP3+ and CD4+CD25+ Tregs in the spleens of BALB/c mice administered with EP for 3 weeks were investigated by flow cytometry. The suppressive function of CD4CD25+ Tregs in association with the proliferative activity of CD4+CD25 effector T cells (Teffs) and the feeder function of CD4 antigen-presenting cells (APCs) were analyzed by carboxyfluorescein succinimidyl ester-dilution assay. The results showed a lowered frequency of CD4+FoxP3+ and CD4+CD25+ Tregs and attenuated suppressive function of CD4+CD25+ Tregs, while the feeder function of APCs was enhanced in the EP-administered mice. On the other hand, the proliferative activity of Teffs was not significantly different in the EP-administered mice. The results suggest that decreased number and function of Tregs, in association with the enhanced feeder function of APCs, may contribute to the enhancement of immune function by EP.

  11. Hydrodynamic Cell Trapping for High Throughput Single-Cell Applications

    Directory of Open Access Journals (Sweden)

    Amin Abbaszadeh Banaeiyan

    2013-12-01

    Full Text Available The possibility to conduct complete cell assays under a precisely controlled environment while consuming minor amounts of chemicals and precious drugs have made microfluidics an interesting candidate for quantitative single-cell studies. Here, we present an application-specific microfluidic device, cellcomb, capable of conducting high-throughput single-cell experiments. The system employs pure hydrodynamic forces for easy cell trapping and is readily fabricated in polydimethylsiloxane (PDMS using soft lithography techniques. The cell-trapping array consists of V-shaped pockets designed to accommodate up to six Saccharomyces cerevisiae (yeast cells with the average diameter of 4 μm. We used this platform to monitor the impact of flow rate modulation on the arsenite (As(III uptake in yeast. Redistribution of a green fluorescent protein (GFP-tagged version of the heat shock protein Hsp104 was followed over time as read out. Results showed a clear reverse correlation between the arsenite uptake and three different adjusted low = 25 nL min−1, moderate = 50 nL min−1, and high = 100 nL min−1 flow rates. We consider the presented device as the first building block of a future integrated application-specific cell-trapping array that can be used to conduct complete single cell experiments on different cell types.

  12. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  13. Label-free determination of the number of biomolecules attached to cells by measurement of the cell's electrophoretic mobility in a microchannel.

    Directory of Open Access Journals (Sweden)

    Atsushi Aki

    Full Text Available We developed a label-free method for a determination of the number of biomolecules attached to individual cells by measuring the electrophoretic mobility of the cells in a microchannel. The surface of a biological cell, which is dispersed in aqueous solution, is normally electrically charged and the charge quantity at the cell's surface is slightly changed once antibody molecules are attached to the cell, based on which we detect the attachment of antibody molecules to the surface of individual red blood cells by electrophoretic mobility measurement. We also analyzed the number of antibody molecules attached to the cell's surface using a flow cytometer. We found that there is a clear correlation between the number of antibody molecules attached to the individual cells and the electrophoretic mobility of the cells. The present technique may well be utilized not only in the field of cell biology but also in the medical and pharmaceutical industries.

  14. EFFECT OF LIPOSOMAL CLODRONATE-DEPENDENT DEPLETION OF PROFESSIONAL ANTIGEN PRESENTING CELLS ON NUMBERS AND PHENOTYPE OF CANINE CD4+CD25+FOXP3+ REGULATORY T CELLS.

    Science.gov (United States)

    Weaver, Kriston F; Stokes, John V; Gunnoe, Sagen A; Follows, Joyce S; Shafer, Lydia; Ammari, Mais G; Archer, Todd M; Thomason, John M; Mackin, Andrew J; Pinchuk, Lesya M

    2014-06-09

    Regulatory T cells (Tregs) are known to control autoreactivity during and subsequent to the development of the peripheral immune system. Professional antigen presenting cells (APCs), dendritic cells (DCs) and monocytes, have an important role in inducing Tregs. For the first time, this study evaluated proportions and phenotypes of Tregs in canine peripheral blood depleted of professional APCs, utilizing liposomal clodronate (LC) and multicolor flow cytometry analysis. Our results demonstrate that LC exposure promoted short term decreases followed by significant increases in the proportions or absolute numbers of CD4(+)CD25(+)FOXP3(+) Tregs in dogs. In general, the LC-dependent Treg fluctuations were similar to the changes in the levels of CD14(+) monocytes in Walker hounds. However, the proportions of monocytes showed more dramatic changes compared to the proportions of Tregs that were visually unchanged after LC treatment over the study period. At the same time, absolute Treg numbers showed, similarly to the levels of CD14(+) monocytes, significant compensatory gains as well as the recovery during the normalization period. We confirm the previous data that CD4(+) T cells with the highest CD25 expression were highly enriched for FOXP3. Furthermore, for the first time, we report that CD4(+)CD25(low)FOXP3(+) is the major regulatory T cell subset affected by LC exposure. The increases within the lowest CD25 expressers of CD4(+)FOXP3(+) cells together with compensatory gains in the proportion of CD14(+) monocytes during compensatory and normalization periods suggest the possible direct or indirect roles of monocytes in active recruitment and generation of Tregs from naïve CD4(+) T cells.

  15. High night temperatures during grain number determination reduce wheat and barley grain yield: a field study.

    Science.gov (United States)

    García, Guillermo A; Dreccer, M Fernanda; Miralles, Daniel J; Serrago, Román A

    2015-11-01

    Warm nights are a widespread predicted feature of climate change. This study investigated the impact of high night temperatures during the critical period for grain yield determination in wheat and barley crops under field conditions, assessing the effects on development, growth and partitioning crop-level processes driving grain number per unit area (GN). Experiments combined: (i) two contrasting radiation and temperature environments: late sowing in 2011 and early sowing in 2013, (ii) two well-adapted crops with similar phenology: bread wheat and two-row malting barley and (iii) two temperature regimes: ambient and high night temperatures. The night temperature increase (ca. 3.9 °C in both crops and growing seasons) was achieved using purpose-built heating chambers placed on the crop at 19:000 hours and removed at 7:00 hours every day from the third detectable stem node to 10 days post-flowering. Across growing seasons and crops, the average minimum temperature during the critical period ranged from 11.2 to 17.2 °C. Wheat and barley grain yield were similarly reduced under warm nights (ca. 7% °C(-1) ), due to GN reductions (ca. 6% °C(-1) ) linked to a lower number of spikes per m(2) . An accelerated development under high night temperatures led to a shorter critical period duration, reducing solar radiation capture with negative consequences for biomass production, GN and therefore, grain yield. The information generated could be used as a starting point to design management and/or breeding strategies to improve crop adaptation facing climate change.

  16. Changes in Foxp3-Positive Regulatory T Cell Number in the Intestine of Dogs With Idiopathic Inflammatory Bowel Disease and Intestinal Lymphoma.

    Science.gov (United States)

    Maeda, S; Ohno, K; Fujiwara-Igarashi, A; Uchida, K; Tsujimoto, H

    2016-01-01

    Although regulatory T cells (Tregs) play an integral role in immunologic tolerance and the maintenance of intestinal homeostasis, their involvement in canine gastrointestinal diseases, including idiopathic inflammatory bowel disease (IBD) and intestinal lymphoma, remains unclear. Here we show altered numbers of forkhead box P3 (Foxp3)-positive Tregs in the intestine of dogs with IBD and intestinal lymphoma. IBD was diagnosed in 48 dogs; small cell intestinal lymphoma was diagnosed in 46 dogs; large cell intestinal lymphoma was diagnosed in 30 dogs; and 25 healthy beagles were used as normal controls. Foxp3-positive Tregs in the duodenal mucosa were examined by immunohistochemistry and immunofluorescence. Duodenal expression of interleukin-10 mRNA was quantified by real-time reverse transcription polymerase chain reaction. The number of Foxp3-positive lamina propria cells and the expression of interleukin-10 mRNA were significantly lower in dogs with IBD than in healthy dogs and dogs with intestinal lymphoma. The number of Foxp3-positive intraepithelial cells was higher in dogs with small cell intestinal lymphoma. Some large cell intestinal lymphoma cases had high numbers of Foxp3-positive cells, but the increase was not statistically significant. Double-labeling immunofluorescence showed that CD3-positive granzyme B-negative helper T cells expressed Foxp3. In small cell intestinal lymphoma cases, the overall survival of dogs with a high Treg density was significantly worse than that of dogs with a normal Treg density. These results suggest that a change in the number of Foxp3-positive Tregs contributes to the pathogenesis of canine IBD and intestinal lymphoma by disrupting mucosal tolerance and suppressing antitumor immunity, respectively.

  17. The effect of spirulina gel on fibroblast cell number after wound healing

    Directory of Open Access Journals (Sweden)

    Fitria Rahmitasari

    2011-12-01

    Full Text Available Background: Wound healing treatment after tooth extraction should be an important consideration due to mouth discomfort and pain. Spirulina (blue green algae consists of C-phycocyanin, b–carotenoids, vitamin E, zinc, some other trace elements and natural phytochemical which are believed to act as antioxidant and takes part in wound healing process. Purpose: The purpose of this study was to examine the effect of spirulina gel on fibroblast cell number after wound healing process. Methods: Twenty eight males guinea pig are devided into four group, 7 guinea pig each. They are control group and treatment group which is given 0%, 3%, 6%, and 12% spirulina gel. After tooth extraction, histopathological evaluation was done to count fibroblast cell. The data was analyzed by One-Way ANOVA and Tukey HSD. Results: The research has proven the relation between the increased growth of fibroblast cell and spirulina gel application. The higher the doses, the more cell growth. Hence, there has been significant different (p < 0.05 among groups. Conclusion: Spirulina gel increases the number of fibroblast in wound after tooth extraction and 12% spirulina gel has the most potential ability.Latar Belakang: Proses penyembuhan luka pasca pencabutan gigi merupakan salah satu hal yang penting karena akan menimbulkan rasa nyeri dan tidak nyaman dalam rongga mulut. Spirulina (Blue green Algae mengandung C-phycocyanin, b-carotenoids, vitamin E, seng, beberapa trace elemen lainnya, dan phytochemical alami yang terbukti dapat berperan sebagai antioksidan dalam proses penyembuhan luka. Tujuan: Tujuan dari penelitian ini adalah untuk mengetahui efek pemberian gel spirulina terhadap jumlah sel fibroblas pada proses penyembuhan luka pasca pencabutan gigi. Metode: Dua puluh delapan ekor guinea pig jantan dibagi dalam 7 kelompok, masing-masing terdiri dari 4 ekor. Kelompok tersebut adalah kelompok kontrol dan kelompok perlakuan yang diberikan gel spirulina dengan konsentrasi 0

  18. Effect of Salinity on the Composition, Number and Size of Epidermal Cells along the Mature Blade of Wheat Leaves

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Salinity inhibits leaf growth in association with changes in cell size. The objective of this study was to determine the spatial distributions of the composition, number and dimensions of epidermal cells in the mature blades of leaf four of wheat seedlings under saline conditions. Plants were grown in loamy soil either with or without 120 mmol/L NaCl in a growth chamber, and harvested after leaf four was fully developed. The results of the spatial distribution analyses of width along the blade showed that salinity not only reduced the width of the leaf blade, but that it also altered the distribution pattern of blade width along the leaf axis. The reduction in the final size of the leaf blade was associated with a reduction in the total number of epidermal cells and in their widths and lengths. This study also revealed the spatial effects of salinity on the blade and epidermal cell dimensions along the leaf axis. In particular, salinity inhibited the total cell number for interstomatal, sister and elongated cells, implying that cell division in wheat leaves is inhibited by salinity. However, the lengths of interstomatal cells were not affected by salinity (unlike those for the sister and elongated cells), suggesting the relative contributions of cell length and numbers to the reduction in the final length of the blade under salinity is dependent on cell type.

  19. Perinatal exposure to bisphenol a increases adult mammary gland progesterone response and cell number.

    Science.gov (United States)

    Ayyanan, Ayyakkannu; Laribi, Ouahiba; Schuepbach-Mallepell, Sonia; Schrick, Christina; Gutierrez, Maria; Tanos, Tamara; Lefebvre, Gregory; Rougemont, Jacques; Yalcin-Ozuysal, Ozden; Brisken, Cathrin

    2011-11-01

    Bisphenol A [BPA, 2,2,-bis (hydroxyphenyl) propane] is one of the highest-volume chemicals produced worldwide. It is detected in body fluids of more than 90% of the human population. Originally synthesized as an estrogenic compound, it is currently utilized to manufacture food and beverage containers resulting in uptake with food and drinks. There is concern that exposure to low doses of BPA, defined as less than or equal to 5 mg/kg body weight /d, may have developmental effects on various hormone-responsive organs including the mammary gland. Here, we asked whether perinatal exposure to a range of low doses of BPA is sufficient to alter mammary gland hormone response later on in life, with a possible impact on breast cancer risk. To mimic human exposure, we added BPA to the drinking water of C57/Bl6 breeding pairs. Analysis of the mammary glands of their daughters at puberty showed that estrogen-dependent transcriptional events were perturbed and the number of terminal end buds, estrogen-induced proliferative structures, was altered in a dose-dependent fashion. Importantly, adult females showed an increase in mammary epithelial cell numbers comparable to that seen in females exposed to diethylbestrol, a compound exposure to which was previously linked to increased breast cancer risk. Molecularly, the mRNAs encoding Wnt-4 and receptor activator of nuclear factor κB ligand, two key mediators of hormone function implicated in control of mammary stem cell proliferation and carcinogenesis, showed increased induction by progesterone in the mammary tissue of exposed mice. Thus, perinatal exposure to environmentally relevant doses of BPA alters long-term hormone response that may increase the propensity to develop breast cancer.

  20. Circulating dendritic cell number and intracellular TNF-α production in women with type 2 diabetes.

    Science.gov (United States)

    Blank, Sally E; Johnson, Emily Carolyn; Weeks, Debra K; Wysham, Carol H

    2012-12-01

    Human dendritic cell (DC) subsets perform specialized functions for surveillance against bacterial and viral infections essential for the management of type 2 diabetes (T2D). Production of tumor necrosis factor-alpha (TNF-α) by DCs acts in autocrine fashion to regulate DC maturation and promotes the inflammatory response. This study was designed to compare circulating DC number and intracellular TNF-α production between post-menopausal women with T2D and healthy women. Blood samples were obtained (n = 21/group) and examined for plasma glucose and TNF-α concentrations, and dendritic cell subset immunophenotype (plasmacytoid, pDC, CD85k(ILT-3)(+)CD123(+)CD16(-)CD14(-) and myeloid, mDC, CD85k(ILT-3)(+)CD33(+)CD123(dim to neg)CD16(-)CD14(dim to neg)). Intracellular production of TNF-α was determined in unstimulated and stimulated DCs. Women with T2D had significantly (P TNF-α concentrations when compared to healthy women. Women with T2D having poor glycemic control (T2D Poor Control, HbA1c ≥ 7%) had fewer circulating pDCs than women with T2D having good glycemic control (T2D Good Control, HbA1c TNF-α in stimulated pDCs. Intracellular production of TNF-α in pDCs was significantly greater in healthy vs. T2D Poor Control (P production of TNF-α did not differ between groups. These findings indicate that TNF-α production by pDCs was reduced in women with T2D and circulating number of pDCs was associated with glycemic control.

  1. Heat transparent high intensity high efficiency solar cell

    Science.gov (United States)

    Evans, J. C., Jr. (Inventor)

    1982-01-01

    An improved solar cell design is described. A surface of each solar cell has a plurality of grooves. Each groove has a vertical face and a slanted face that is covered by a reflecting metal. Light rays are reflected from the slanted face through the vertical face where they traverse a photovoltaic junction. As the light rays travel to the slanted face of an adjacent groove, they again traverse the junction. The underside of the reflecting coating directs the light rays toward the opposite surface of solar cell as they traverse the junction again. When the light rays travel through the solar cell and reach the saw toothed grooves on the under side, the process of reflection and repeatedly traversing the junction again takes place. The light rays ultimately emerge from the solar cell. These solar cells are particularly useful at very high levels of insolation because the infrared or heat radiation passes through the cells without being appreciably absorbed to heat the cell.

  2. Apparatus for measuring pressure-driven transport through channels at high Knudsen numbers

    Science.gov (United States)

    Karakitsiou, S.; Holst, B.; Hoffmann, A. C.

    2016-12-01

    The pressure-driven gas flow through micro- and nano-porous structures is particularly interesting for innovative technologies such as microelectromechanical and nano-mechanical-electrical systems. The classical continuum assumption breaks down for rarefied flow through channels with a characteristic dimension comparable to the mean free path of the gas. Theories based on molecular interactions have been formulated to predict the flow at high Knudsen numbers. Measuring rarefied gas flow experimentally is a challenge since only a few studies have been able to determine flowrates in the molecular flow regime. Here we present the design of an experimental apparatus, which can be used to measure the flow of gases through nano- and microscale channels in the flow regimes where molecular effects are critical. The equations used to design the apparatus are given, focusing on the slip and transition flow regimes (together sometimes called "Intermediate flow regime"). A channel with a diameter of 325 μm ± 5μm and a length of 2 mm was tested experimentally with the apparatus for a wide range of Knudsen numbers (10-2 < Kn < 1 × 105) demonstrating its suitability through the slip and transition regime (2.23 × 10-2 < Kn < 2.26).

  3. Finite volume simulation of 2-D steady square lid driven cavity flow at high reynolds numbers

    Directory of Open Access Journals (Sweden)

    K. Yapici

    2013-12-01

    Full Text Available In this work, computer simulation results of steady incompressible flow in a 2-D square lid-driven cavity up to Reynolds number (Re 65000 are presented and compared with those of earlier studies. The governing flow equations are solved by using the finite volume approach. Quadratic upstream interpolation for convective kinematics (QUICK is used for the approximation of the convective terms in the flow equations. In the implementation of QUICK, the deferred correction technique is adopted. A non-uniform staggered grid arrangement of 768x768 is employed to discretize the flow geometry. Algebraic forms of the coupled flow equations are then solved through the iterative SIMPLE (Semi-Implicit Method for Pressure-Linked Equation algorithm. The outlined computational methodology allows one to meet the main objective of this work, which is to address the computational convergence and wiggled flow problems encountered at high Reynolds and Peclet (Pe numbers. Furthermore, after Re > 25000 additional vortexes appear at the bottom left and right corners that have not been observed in earlier studies.

  4. Assessment of an Euler-Interacting Boundary Layer Method Using High Reynolds Number Transonic Flight Data

    Science.gov (United States)

    Bonhaus, Daryl L.; Maddalon, Dal V.

    1998-01-01

    Flight-measured high Reynolds number turbulent-flow pressure distributions on a transport wing in transonic flow are compared to unstructured-grid calculations to assess the predictive ability of a three-dimensional Euler code (USM3D) coupled to an interacting boundary layer module. The two experimental pressure distributions selected for comparative analysis with the calculations are complex and turbulent but typical of an advanced technology laminar flow wing. An advancing front method (VGRID) was used to generate several tetrahedral grids for each test case. Initial calculations left considerable room for improvement in accuracy. Studies were then made of experimental errors, transition location, viscous effects, nacelle flow modeling, number and placement of spanwise boundary layer stations, and grid resolution. The most significant improvements in the accuracy of the calculations were gained by improvement of the nacelle flow model and by refinement of the computational grid. Final calculations yield results in close agreement with the experiment. Indications are that further grid refinement would produce additional improvement but would require more computer memory than is available. The appendix data compare the experimental attachment line location with calculations for different grid sizes. Good agreement is obtained between the experimental and calculated attachment line locations.

  5. Fractal properties of isovelocity surfaces in high Reynolds number laboratory shear flows

    Science.gov (United States)

    Praskovsky, Alexander A.; Foss, John F.; Kleis, Stanley J.; Karyakin, Mikhail Yu.

    1993-08-01

    The fractal properties of isovelocity surfaces are studied in three high Reynolds number (Rλ≊2.0×102-3.2×103) laboratory shear flows using the standard box-counting method. The fractal dimension D=-d(log Nr)/d(log r) was estimated within the range of box sizes r from several Kolmogorov scales up to several integral scales (Nr is the number of boxes with size r required to cover the line intersection of an isovelocity surface). The inertial subrange was of particular interest in this investigation. Measurements were carried out for external intermittency factors γ≊0.6-1.0. The data were processed using threshold levels U±2.5u' (U and u' denote mean and rms values of longitudinal velocity). Over the parameters studied, no wide range of constant fractal dimension was found. On the other hand, the accuracy of constant fractal dimension approximation with D≊0.4 over the inertial subranges was shown to be similar to that of the Kolmogorov [Dokl. Akad. Nauk SSSR 30, 301 (1941)] ``two-thirds law.''

  6. Improvements of a nano-scale crossed hot-wire for high Reynolds number measurements

    Science.gov (United States)

    Fan, Yuyang; Hultmark, Marcus

    2015-11-01

    Hot-wire anemometry, despite its limited spatial and temporal resolution, is still the preferred tool for high Reynolds number flow measurements, mainly due to the continuous signal. To address the resolution issues, the Nano-Scale Thermal Anemometry Probe (NSTAP) was developed at Princeton University. The NSTAP has a sensing volume more than one order of magnitude smaller than conventional hot-wires, and it has displayed superior performance. However, the NSTAP can only measure a single component of the velocity. Using a novel combining method, a probe that enables two-component velocity measurements has been created (the x-NSTAP). The measurement volume is approximately 50 × 50 × 50 μ m, more than one order of magnitude smaller in all directions compared to conventional crossed hot-wires. The x-NSTAP has been further improved to allow more accurate measurements with the help of flow visualization using a scaled model but matching Reynolds number. Results from turbulent flow measurements with the new x-NSTAP are also presented. Supported under NSF grant CBET-1510100 (program manager Dimitrios Papavassiliou).

  7. Longitudinal and transverse structure functions in high Reynolds-number magneto-hydrodynamic turbulence

    CERN Document Server

    Friedrich, J; Schäfer, T; Grauer, R

    2016-01-01

    We investigate the scaling behavior of longitudinal and transverse structure functions in homogeneous and isotropic magneto-hydrodynamic (MHD) turbulence by means of an exact hierarchy of structure function equations as well as by direct numerical simulations of two- and three-dimensional MHD turbulence. In particular, rescaling relations between longitudinal and transverse structure functions are derived and utilized in order to compare different scaling behavior in the inertial range. It is found that there are no substantial differences between longitudinal and transverse structure functions in MHD turbulence. This finding stands in contrast to the case of hydrodynamic turbulence which shows persistent differences even at high Reynolds numbers. We propose a physical picture that is based on an effective reduction of pressure contributions due to local regions of same magnitude and alignment of velocity and magnetic field fluctuations. Finally, our findings underline the importance of the pressure term for ...

  8. Particle-number conserving analysis of the high-spin structure of $^{159}$Ho

    CERN Document Server

    Zhang, Zhen-Hua

    2016-01-01

    The high-spin rotational bands in odd-$Z$ nuclei $^{159}$Ho ($Z=67$) are investigated using the cranked shell model with the pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments and their variations with the rotational frequency $\\hbar\\omega$ are reproduced very well by the calculations. The splitting between the signature partners of the yrast band $7/2^-[523]$ is discussed and the splitting of the excited band $7/2^+[404]$ above $\\hbar\\omega \\sim 0.30$~MeV is predicted due to the level crossing with $1/2^+[411]$. The calculated $B(E2)$ transition probabilities are also suggested for future experiments.

  9. Double large field stereoscopic PIV in a high Reynolds number turbulent boundary layer

    Science.gov (United States)

    Coudert, S.; Foucaut, J. M.; Kostas, J.; Stanislas, M.; Braud, P.; Fourment, C.; Delville, J.; Tutkun, M.; Mehdi, F.; Johansson, P.; George, W. K.

    2011-01-01

    An experiment on a flat plate turbulent boundary layer at high Reynolds number has been carried out in the Laboratoire de Mecanique de Lille (LML, UMR CNRS 8107) wind tunnel. This experiment was performed jointly with LEA (UMR CNRS 6609) in Poitiers (France) and Chalmers University of Technology (Sweden), in the frame of the WALLTURB European project. The simultaneous recording of 143 hot wires in one transverse plane and of two perpendicular stereoscopic PIV fields was performed successfully. The first SPIV plane is 1 cm upstream of the hot wire rake and the second is both orthogonal to the first one and to the wall. The first PIV results show a blockage effect which based on both statistical results (i.e. mean, RMS and spatial correlation) and a potential model does not seem to affect the turbulence organization.

  10. Dissipative particle dynamics of diffusion-NMR requires high Schmidt-numbers

    Science.gov (United States)

    Azhar, Mueed; Greiner, Andreas; Korvink, Jan G.; Kauzlarić, David

    2016-06-01

    We present an efficient mesoscale model to simulate the diffusion measurement with nuclear magnetic resonance (NMR). On the level of mesoscopic thermal motion of fluid particles, we couple the Bloch equations with dissipative particle dynamics (DPD). Thereby we establish a physically consistent scaling relation between the diffusion constant measured for DPD-particles and the diffusion constant of a real fluid. The latter is based on a splitting into a centre-of-mass contribution represented by DPD, and an internal contribution which is not resolved in the DPD-level of description. As a consequence, simulating the centre-of-mass contribution with DPD requires high Schmidt numbers. After a verification for fundamental pulse sequences, we apply the NMR-DPD method to NMR diffusion measurements of anisotropic fluids, and of fluids restricted by walls of microfluidic channels. For the latter, the free diffusion and the localisation regime are considered.

  11. Physical state & copy number of high risk human papillomavirus type 16 DNA in progression of cervical cancer

    Directory of Open Access Journals (Sweden)

    Shirish Shukla

    2014-01-01

    Full Text Available Background & objectives: High-risk human papilloma virus (HR-HPV infection and its integration in host genome is a key event in malignant transformation of cervical cells. HPV16 being a dominant HR-HPV type, we undertook this study to analyze if viral load and physical state of the virus correlated with each other in the absence of other confounding variables and examined their potential as predictors of progressive cervical lesions. Methods: Both, viral load and integration status of HPV16 were determined by real time URR PCR and estimation of E2:E6 ratio in a total of 130 PGMY-RLB -confirmed, monotypic HPV16-infected cervical DNA samples from biopsies of cytology-confirmed low grade (LSIL, 30 and high grade (HSIL, 30, and invasive carcinoma, (squamous cell carcinoma SCC, 70 cases. Results: Investigation of DNA samples revealed a gradual increase in HPV16 viral load over several magnitudes and increased frequency of integration from LSIL to HSIL and HSIL to invasive cancer in relation to the severity of lesions in monotypic HPV16-infected cervical tissues. In a substantial number of precancer (11/60 and cancer cases (29/70, HPV16 was detected in concomitant mixed form. The concomitant form of HPV16 genome carried significantly higher viral load. Interpretation & conclusions: Overall, viral load and integration increased with disease severity and could be useful biomarkers in disease progression, at least, in HPV16-infected cervical pre-cancer and cancer lesions.

  12. High initial amplitude and high Mach number effects on the evolution of the single-mode Richtmyer-Meshkov instability.

    Science.gov (United States)

    Rikanati, A; Oron, D; Sadot, O; Shvarts, D

    2003-02-01

    Effects of high-Mach numbers and high initial amplitudes on the evolution of the single-mode Richtmyer-Meshkov shock-wave induced hydrodynamic instability are studied using theoretical models, experiments, and numerical simulations. Two regimes in which there is a significant deviation from the linear dependence of the initial velocity on the initial perturbation amplitude are defined and characterized. In one, the observed reduction of the initial velocity is primarily due to large initial amplitudes. This effect is accurately modeled by a vorticity deposition model, quantifying both the effect of the initial perturbation amplitude and the exact shape of the interface. In the other, the reduction is dominated by the proximity of the shock wave to the interface. This effect is modeled by a modified incompressible model where the shock wave is mimicked by a moving bounding wall. These results are supplemented with high initial amplitude Mach 1.2 shock-tube experiments, enabling separation of the two effects. It is shown that in most of the previous experiments, the observed reduction is predominantly due to the effect of high initial amplitudes.

  13. Mitigation of naphthenate related production upsets in high TAN (Total Acid Number) crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Ostojic, Nik [Maersk Oil, Copenhagen (Denmark); Vijn, Pieter; Reiners, Robert [Champion Technologies Europe BV, Delden (Netherlands)

    2012-07-01

    This paper describes a strategy for prediction, evaluation and mitigation of calcium naphthenate related production problems. Developing fields with acidic crude in the North Sea, West Africa, Bohai Bay (China) and Brazil is becoming more common in recent years. The high acid crude contains a considerable amount of naphthenic acids, typically having a Total Acid Number (TAN) higher than 0.5 mg KOH/g. Formation of either hard type 'calcium naphthenate precipitates' or soft type 'sodium carboxylate/emulsions' during crude oil production can lead to severe flow assurance and separation problems. In severe cases this may lead to production shutdowns to clean-up the equipment. A number of different naphthenate mitigation approaches have been published but no one particular approach is considered to be the most efficient as it depends significantly on the particular field conditions. Initially, this problem was addressed by deploying large volumes of (usually organic) acid, but more recently high efficiency low dose naphthenate inhibitors have been introduced. For predicting naphthenate scaling potential, methods were developed to determine the concentration of 1230 Dalton naphthenic tetra acid (ARN acids) in either deposit or crude oil and this information can be used to locate and potentially isolate the problem to a certain reservoir. Also, methods were developed to design suitable low dose naphthenate inhibitors. As these inhibitors are field tested, monitoring is required to ensure the product is performing most efficiently. In cases of tight emulsions however, this is less difficult as the oil dehydration and water quality is affected instantly. Methods were developed to allow monitoring of the calcium naphthenate deposition in field trails, thus allow trending and evaluation of the chemicals performance. After detailed analyses and discussions of the developed methods, a North Sea case history is presented reviewing several years of treating

  14. The variational multiscale element free Galerkin method for MHD flows at high Hartmann numbers

    Science.gov (United States)

    Zhang, Lin; Ouyang, Jie; Zhang, Xiaohua

    2013-04-01

    The aim of the paper is the development of an efficient numerical algorithm for the solution of magnetohydrodynamics (MHD) flow problems with either fully insulating walls or partially insulating and partially conducting walls. Toward this, we first extend the influence domain of the shape function for the element free Galerkin (EFG) method to have arbitrary shape. When the influence factor approaches 1, we find that the EFG shape function almost has the Delta property at the node (i.e. the value of the EFG shape function of the node is nearly equal to 1 at the position of this node) as well as the property of slices in the influence domain of the node (i.e. the EFG shape function in the influence domain of the node is nearly constructed by different functions defined in different slices). Therefore, for MHD flow problems at high Hartmann numbers we follow the idea of the variational multiscale finite element method (VMFEM) to combine the EFG method with the variational multiscale (VM) method, namely the variational multiscale element free Galerkin (VMEFG) method is proposed. Subsequently, in order to validate the proposed method, we compare the obtained approximate solutions with the exact solutions for some problems where such exact solutions are known. Finally, several benchmark problems of MHD flows are simulated and the numerical results indicate that the VMEFG method is stable at moderate and high values of Hartmann number. Another important feature of this method is that the stabilization parameter has appeared naturally via the solution of the fine scale problem. Meanwhile, because this proposed method is a type of meshless method, it can avoid the need for meshing, a very demanding task for complicated geometry problems.

  15. The Spectral Amplitude of Stellar Convection and Its Scaling in the High-Rayleigh-number Regime

    Science.gov (United States)

    Featherstone, Nicholas A.; Hindman, Bradley W.

    2016-02-01

    Convection plays a central role in the dynamics of any stellar interior, and yet its operation remains largely hidden from direct observation. As a result, much of our understanding concerning stellar convection necessarily derives from theoretical and computational models. The Sun is, however, exceptional in that regard. The wealth of observational data afforded by its proximity provides a unique test bed for comparing convection models against observations. When such comparisons are carried out, surprising inconsistencies between those models and observations become apparent. Both photospheric and helioseismic measurements suggest that convection simulations may overestimate convective flow speeds on large spatial scales. Moreover, many solar convection simulations have difficulty reproducing the observed solar differential rotation owing to this apparent overestimation. We present a series of three-dimensional stellar convection simulations designed to examine how the amplitude and spectral distribution of convective flows are established within a star’s interior. While these simulations are nonmagnetic and nonrotating in nature, they demonstrate two robust phenomena. When run with sufficiently high Rayleigh number, the integrated kinetic energy of the convection becomes effectively independent of thermal diffusion, but the spectral distribution of that kinetic energy remains sensitive to both of these quantities. A simulation that has converged to a diffusion-independent value of kinetic energy will divide that energy between spatial scales such that low-wavenumber power is overestimated and high-wavenumber power is underestimated relative to a comparable system possessing higher Rayleigh number. We discuss the implications of these results in light of the current inconsistencies between models and observations.

  16. Genome-wide copy number profiling of single cells in S-phase reveals DNA-replication domains.

    Science.gov (United States)

    Van der Aa, Niels; Cheng, Jiqiu; Mateiu, Ligia; Zamani Esteki, Masoud; Kumar, Parveen; Dimitriadou, Eftychia; Vanneste, Evelyne; Moreau, Yves; Vermeesch, Joris Robert; Voet, Thierry

    2013-04-01

    Single-cell genomics is revolutionizing basic genome research and clinical genetic diagnosis. However, none of the current research or clinical methods for single-cell analysis distinguishes between the analysis of a cell in G1-, S- or G2/M-phase of the cell cycle. Here, we demonstrate by means of array comparative genomic hybridization that charting the DNA copy number landscape of a cell in S-phase requires conceptually different approaches to that of a cell in G1- or G2/M-phase. Remarkably, despite single-cell whole-genome amplification artifacts, the log2 intensity ratios of single S-phase cells oscillate according to early and late replication domains, which in turn leads to the detection of significantly more DNA imbalances when compared with a cell in G1- or G2/M-phase. Although these DNA imbalances may, on the one hand, be falsely interpreted as genuine structural aberrations in the S-phase cell's copy number profile and hence lead to misdiagnosis, on the other hand, the ability to detect replication domains genome wide in one cell has important applications in DNA-replication research. Genome-wide cell-type-specific early and late replicating domains have been identified by analyses of DNA from populations of cells, but cell-to-cell differences in DNA replication may be important in genome stability, disease aetiology and various other cellular processes.

  17. The effects of phototherapy on the numbers of circulating natural killer cells and T lymphocytes in psoriasis.

    LENUS (Irish Health Repository)

    Tobin, A M

    2009-04-01

    The innate immune system is believed to be important in the pathogenesis of psoriasis and natural killer (NK) have been found in increased numbers in psoriatic plaques. Alterations in the numbers of NK cells in peripheral blood have been reported. We investigated the effect of phototherapy on levels of peripheral NK cells and lymphocytes in patients with psoriasis. In nine patients whom we followed before, during and after narrowband ultraviolet B (UVB) treatment there were no differences in the numbers of circulating lymphocytes, lymphocyte subsets or cells expressing NK markers and controls. Treatment with narrowband UVB did, however, significantly lower circulating CD4 counts which gradually recovered posttreatment.

  18. Arabidopsis thaliana leaves with altered chloroplast numbers and chloroplast movement exhibit impaired adjustments to both low and high light

    OpenAIRE

    Königer, Martina; Delamaide, Joy A.; Marlow, Elizabeth D.; Harris, Gary C.

    2008-01-01

    The effects of chloroplast number and size on the capacity for blue light-dependent chloroplast movement, the ability to increase light absorption under low light, and the susceptibility to photoinhibition were investigated in Arabidopsis thaliana. Leaves of wild-type and chloroplast number mutants with mean chloroplast numbers ranging from 120 to two per mesophyll cell were analysed. Chloroplast movement was monitored as changes in light transmission through the leaves. Light transmission wa...

  19. Increased numbers of mast cells in the hyperplastic buccal mucosa of the zinc-deficient rat.

    Science.gov (United States)

    Kreavich, M E; Meyer, J; Waterhouse, J P

    1981-02-01

    Six weanling male Sprague Dawley rats were fed a diet containing 0.4 ppm Zn and seven were fed an identical diet except for 40 ppm Zn. After 4 weeks, specimens of buccal mucosa in the region facing the molar teeth were removed. Paraffin sections, cut at 6 micron, were stained with toluidine blue, and tracings made of five sections per animal, spaced no less than 60 micron apart. Counts of mast cells of five sections length of section were made in a superficial zone of the lamina propria of 50 micron width and a deeper zone of 250 micron width. The average number of mast cells, per mm in the subepithelial zone of the experimental animals was 15.4, the range 9.2-33.1. The control average was 4.0; the range was 2.9-5.3. No increase was found in the deeper zone. The epithelium was parakeratotic and its thickness was increased two-fold. In the peripheral portion of the section, cellular and keratin layers were evenly increased in thickness, but in the central portion a disproportionate, nearly four-fold increase occurred in the keratin layer and a lesser increase in the cellular layer.

  20. Neonatal handling reduces the number of cells in the medial preoptic area of female rats.

    Science.gov (United States)

    Camozzato, Tatiane S C; Winkelmann-Duarte, Elisa C; Padilha, Camila B; Miguel, Sandro P R; Bonzanini, Laisa; Anselmo-Franci, Janete A; Fernandes, Marilda C; Lucion, Aldo B

    2009-01-09

    Early-life events may induce alterations in neuronal function in adulthood. A crucial aspect in studying long-lasting effects induced by environmental interventions imposed to the animal several weeks before is finding a stable change that could be causally related to the phenotype observed in adulthood. In order to explain an adult trait, it seems necessary to look back to early life and establish a temporal line between events. The neonatal handling procedure is an experimental tool to analyze the long-lasting impact of early-life events. Aside from the neuroendocrine response to stress, neonatal handling also alters the functionality of the hypothalamus-pituitary-gonad (HPG) axis. Reductions in ovulation and surge of the luteinizing hormone (LH) on the proestrous day were shown in female rats. Considering the importance of the medial preoptic area (MPA) for the control of ovulation, the present study aimed to verify the effects of neonatal handling on the numerical density and cell size in the MPA in 11-day-old and 90-day-old female rats. Cellular proliferation was also assessed using BrdU (5-bromo-2'-deoxyuridine) in 11-day-old pups. Results showed that neonatal handling induces a stable reduction in the number of cells and in the size of the cell soma, which were lower in handled females than in nonhandled ones at both ages. Cellular proliferation in the MPA was also reduced 24 h after the last manipulation. The repeated mother-infant disruption imposed by the handling procedure "lesioned" the MPA. The dysfunction in the ovulation mechanisms induced by the handling procedure could be related to that neuronal loss. The study also illustrates the impact of an environmental intervention on the development of the brain.

  1. High Reynolds number flows about bodies of revolution with application to submarines and torpedoes

    Science.gov (United States)

    Jimenez, Juan M.

    x 106, which seem to have collapsed. The sail wake experiments demonstrated the significance of the sail tip vortex when the submarine is at a nonzero yaw angle. As the yaw angle is increased the circulation of the sail tip vortex increases. As the yaw angle is further increased the boundary layer separates from the sail with an overall drop in circulation. A similar phenomenon is observed for the junction vortex with the exception that when the yaw angle is further increased to 17 degrees the circulation continues to increase at a slower rate. Also, the circulation values for the sail tip vortex are about an order of magnitude larger than those of the junction vortex. The effects of the support on the wake development are similar to the effects introduced by the sail on a submarine wake (except for the absence of the tip flow). The presence of the support affects the flow differently for different Reynolds numbers emphasizing the importance of high Reynolds number studies to better understand submarine flows.

  2. High Throughput Method to Quantify Anterior-Posterior Polarity of T-Cells and Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Susan J. Marriott

    2011-11-01

    Full Text Available The virologic synapse (VS, which is formed between a virus-infected and uninfected cell, plays a central role in the transmission of certain viruses, such as HIV and HTLV-1. During VS formation, HTLV-1-infected T-cells polarize cellular and viral proteins toward the uninfected T-cell. This polarization resembles anterior-posterior cell polarity induced by immunological synapse (IS formation, which is more extensively characterized than VS formation and occurs when a T-cell interacts with an antigen-presenting cell. One measure of cell polarity induced by both IS or VS formation is the repositioning of the microtubule organizing center (MTOC relative to the contact point with the interacting cell. Here we describe an automated, high throughput system to score repositioning of the MTOC and thereby cell polarity establishment. The method rapidly and accurately calculates the angle between the MTOC and the IS for thousands of cells. We also show that the system can be adapted to score anterior-posterior polarity establishment of epithelial cells. This general approach represents a significant advancement over manual cell polarity scoring, which is subject to experimenter bias and requires more time and effort to evaluate large numbers of cells.

  3. Methodologies for high efficiency perovskite solar cells.

    Science.gov (United States)

    Park, Nam-Gyu

    2016-01-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  4. Methodologies for high efficiency perovskite solar cells

    Science.gov (United States)

    Park, Nam-Gyu

    2016-06-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  5. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... (RDE) and (ii) a gas diffusion electrode (GDE) setup designed for experiments in conc. H3PO4. The pressurized cell is demonstrated by tests on polycrystalline platinum electrodes up to 150 ºC. Functionality of the RDE system is proved studying the oxygen reduction reaction (ORR) at temperatures up...... to 140 ºC and oxygen pressures up to ~100 bar at room temperature. The GDE cell is successfully tested at 130 ºC by means of direct oxidation of methanol and ethanol, respectively. In the second part of the thesis, the emphasis is put on the ORR in H3PO4 with particular focus on the mass transport...

  6. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  7. Class-switched marginal zone B cells in spleen have relatively low numbers of somatic mutations

    NARCIS (Netherlands)

    Hendricks, Jacobus; Visser, Annie; Dammers, Peter M.; Burgerhof, Johannes G. M.; Bos, Nicolaas A.; Kroese, Frans G. M.

    2011-01-01

    The vast majority of rodent splenic marginal zone (MZ)-B cells are naive IgM(+) cells. A small fraction of these MZ-B cells carry mutated V-genes, and represent IgM(+) memory MZ-B cells. Here we reveal further heterogeneity of B cells with a MZ-B cell phenotype, by providing evidence for the existen

  8. Correlations between Photovoltaic Characteristics, Adsorption Number, and Regeneration Kinetics in Dye-Sensitized Solar Cells Revealed by Scanning Photocurrent Microscopy.

    Science.gov (United States)

    Mitsui, Masaaki; Kawano, Yuya; Mori, Kyosuke; Wakabayashi, Naoto

    2015-06-30

    Newly developed simultaneous scanning photocurrent and luminescence microscopy was applied to ruthenium-based dye-sensitized solar cells (DSCs) comprising a cover glass photoanode with a 100 nm thick TiO2 layer. Using this, we have investigated the lateral variations of several parameters of these DSCs under short-circuit conditions. Simultaneous measurement of photocurrent and luminescence images for the same area of the DSC demonstrated submicrometric lateral resolution of our photocurrent microscopy, which is approximately 10 times better than the resolution of photocurrent microscopy used in past studies. The photovoltaic parameters, such as short-circuit current density, open-circuit voltage, and charge-collection efficiency, were thus evaluated for local (or submicrometric) regions of the DSCs. Furthermore, the photocurrent saturation behavior of the DSCs was examined as a function of the excitation rate and analyzed on the basis of a three-state kinetic model. This protocol allowed for quantification of the dye-adsorption number and dye-regeneration rate constant for any local area of the DSCs. Consequently, the correlations between the dye adsorption number, photovoltaic parameters, and regeneration rate constant, which are difficult to address through examination of the entire cell, were revealed by the "zoom-in" approach utilizing this high-resolution photocurrent microscopy.

  9. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number.

    Science.gov (United States)

    Li, Huchen; Torres-Garcia, Jesus; Latrasse, David; Benhamed, Moussa; Schilderink, Stefan; Zhou, Wenkun; Kulikova, Olga; Hirt, Heribert; Bisseling, Ton

    2017-08-30

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodelling factors have been implicated in regulating the switch from stem cells to transit-amplifying cells. Here we show that two Arabidopsis thaliana paralogs encoding plant-specific histone deacetylases, HDT1 and HDT2, regulate a second switch from transit-amplifying cells to expanding cells. Knockdown of HDT½ (hdt1,2i) results in an earlier switch and causes a reduced RM cell number. Our data show that HDT½ negatively regulate the acetylation level of the C19-GIBBERELLIN 2-OXIDASE 2 (GA2ox2) locus and repress the expression of GA2ox2 in the RM and elongation zone. Overexpression of GA2ox2 in the RM phenocopies the hdt1,2i phenotype. Conversely, knockout of GA2ox2 partially rescues the root growth defect of hdt1,2i. These results suggest that by repressing the expression of GA2ox2, HDT½ likely fine-tune gibberellin metabolism and they are crucial for regulating the switch from cell division to expansion to determine RM cell number. We propose that HDT½ function as part of a mechanism that modulates root growth in response to environmental factors. © 2017 American Society of Plant Biologists. All rights reserved.

  10. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number

    KAUST Repository

    Li, Huchen

    2017-08-31

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodelling factors have been implicated in regulating the switch from stem cells to transit-amplifying cells. Here we show that two Arabidopsis thaliana paralogs encoding plant-specific histone deacetylases, HDT1 and HDT2, regulate a second switch from transit-amplifying cells to expanding cells. Knockdown of HDT½ (hdt1,2i) results in an earlier switch and causes a reduced RM cell number. Our data show that HDT½ negatively regulate the acetylation level of the C19-GIBBERELLIN 2-OXIDASE 2 (GA2ox2) locus and repress the expression of GA2ox2 in the RM and elongation zone. Overexpression of GA2ox2 in the RM phenocopies the hdt1,2i phenotype. Conversely, knockout of GA2ox2 partially rescues the root growth defect of hdt1,2i. These results suggest that by repressing the expression of GA2ox2, HDT½ likely fine-tune gibberellin metabolism and they are crucial for regulating the switch from cell division to expansion to determine RM cell number. We propose that HDT½ function as part of a mechanism that modulates root growth in response to environmental factors.

  11. Distinct population of highly malignant cells in a head and neck squamous cell carcinoma cell line established by xenograft model

    Directory of Open Access Journals (Sweden)

    Jan Chia-Ing

    2009-11-01

    Full Text Available Abstract The progression and metastasis of solid tumors, including head and neck squamous cell carcinoma (HNSCC, have been related to the behavior of a small subpopulation of cancer stem cells. Here, we have established a highly malignant HNSCC cell line, SASVO3, from primary tumors using three sequential rounds of xenotransplantation. SASVO3 possesses enhanced tumorigenic ability both in vitro and in vivo. Moreover, SASVO3 exhibits properties of cancer stem cells, including that increased the abilities of sphere-forming, the number of side population cells, the potential of transplanted tumor growth and elevated expression of the stem cell marker Bmi1. Injection of SASVO3 into the tail vein of nude mice resulted in lung metastases. These results are consistent with the postulate that the malignant and/or metastasis potential of HNSCC cells may reside in a stem-like subpopulation.

  12. High-flux solar furnace processing of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R.; Landry, M.D.; Menna, P.; Bingham, C.E.; Lewandowski, A.; Ciszek, T.F. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-06-10

    We used a 10-kW, high-flux solar furnace (HFSF) to diffuse the front-surface n{sup +}-p junction and the back-surface p-p{sup +} junction of single-crystal silicon solar cells in one processing step. We found that all of these HFSF-processed cells have better conversion efficiencies than control cells of identical structures fabricated by conventional furnace diffusion methods. We also used the HFSF to crystallize a-Si:H thin films on glass, to texture crystalline silicon surfaces, to deposit gold contacts on silicon wafers, and to getter impurities from metallurgical grade silicon. HFSF processing offers several advantages over conventional furnace processing: (1) it provides a cold-wall process, which reduces contamination; (2) temperature versus time profiles can be precisely controlled; (3) wavelength, intensity, and spatial distribution of the incident solar flux can be controlled and changed rapidly; (4) a number of high-temperature processing steps can be performed simultaneously; and (5) combined quantum and thermal effects may benefit overall cell performance. We conclude that HFSF processing of silicon solar cells has the potential to improve cell efficiency, reduce cell fabrication costs, and also be an environmentally friendly manufacturing method. We have also demonstrated that the HFSF can be used to achieve solid-phase crystallization of a-Si:H at very high speed

  13. Experimental container shape dependence and heat transport scaling of Rayleigh-Bénard convection of high-Prandtl-number fluids

    Science.gov (United States)

    Johnston, Stephen; Fonda, Enrico; Sreenivasan, Katepalli R.; Ranjan, Devesh

    2016-11-01

    Both experiments and simulations on Rayleigh-Bénard convection with fluids of Prandtl numbers 5 and below have shown that the container shape influences the flow structure. Here, we investigate similar dependences of convection of fluids with Prandtl numbers of up to 104. The convection cells have aspect ratio of order unity, and we use cubic and cylindrical shapes. Visual analysis using a noninvasive photochromic dye technique indicates the distinct large-scale flow patterns in both square and cylindrical test cells. The stability of these flow patterns is explored. Also presented are results on the Nusselt-Rayleigh scaling for moderate Rayleigh numbers.

  14. Analysis of the high Reynolds number 2D tests on a wind turbine airfoil performed at two different wind tunnels

    Science.gov (United States)

    Pires, O.; Munduate, X.; Ceyhan, O.; Jacobs, M.; Madsen, J.; Schepers, J. G.

    2016-09-01

    2D wind tunnel tests at high Reynolds numbers have been done within the EU FP7 AVATAR project (Advanced Aerodynamic Tools of lArge Rotors) on the DU00-W-212 airfoil and at two different test facilities: the DNW High Pressure Wind Tunnel in Gottingen (HDG) and the LM Wind Power in-house wind tunnel. Two conditions of Reynolds numbers have been performed in both tests: 3 and 6 million. The Mach number and turbulence intensity values are similar in both wind tunnels at the 3 million Reynolds number test, while they are significantly different at 6 million Reynolds number. The paper presents a comparison of the data obtained from the two wind tunnels, showing good repeatability at 3 million Reynolds number and differences at 6 million Reynolds number that are consistent with the different Mach number and turbulence intensity values.

  15. Wall-modeled large-eddy simulation of transonic airfoil buffet at high Reynolds number

    Science.gov (United States)

    Fukushima, Yuma; Kawai, Soshi

    2016-11-01

    In this study, we conduct the wall-modeled large-eddy simulation (LES) of transonic buffet phenomena over the OAT15A supercritical airfoil at high Reynolds number. The transonic airfoil buffet involves shock-turbulent boundary layer interactions and shock vibration associated with the flow separation downstream of the shock wave. The wall-modeled LES developed by Kawai and Larsson PoF (2012) is tuned on the K supercomputer for high-fidelity simulation. We first show the capability of the present wall-modeled LES on the transonic airfoil buffet phenomena and then investigate the detailed flow physics of unsteadiness of shock waves and separated boundary layer interaction phenomena. We also focus on the sustaining mechanism of the buffet phenomena, including the source of the pressure waves propagated from the trailing edge and the interactions between the shock wave and the generated sound waves. This work was supported in part by MEXT as a social and scientific priority issue to be tackled by using post-K computer. Computer resources of the K computer was provided by the RIKEN Advanced Institute for Computational Science (Project ID: hp150254).

  16. Radiative properties of high wire number tungsten arrays with implosion times up to 250 ns

    Science.gov (United States)

    Deeney, C.; Coverdale, C. A.; Douglas, M. R.; Struve, K. W.; Spielman, R. B.; Stygar, W. A.; Peterson, D. L.; Roderick, N. F.; Haines, M. G.; Beg, F. N.; Ruiz-Camacho, J.

    1999-09-01

    High wire number, 25-mm-diameter tungsten wire arrays have been imploded on the 8-MA Saturn generator [R. B. Spielman et al., AIP Conference Proceeding 195, 3 (American Institute of Physics, Woodbury, NY 1989)], operating in a long-pulse mode. By varying the mass of the arrays from 710 to 6140 μg/cm, implosion times of 130-250 ns have been obtained with implosion velocities of 50-25 cm/μs, respectively. These Z-pinch implosions produced plasmas with millimeter diameters that radiated 600-800 kJ of x-rays, with powers of 20-49 TW; the corresponding pulsewidths were 19-7.5 ns, with risetimes ranging from 6.5 to 4.0 ns. These powers and pulsewidths are similar to those achieved with 50-ns implosion times on Saturn. Two-dimensional, radiation-magnetohydrodynamic calculations indicate that the imploding shells in these long implosion time experiments are comparable in width to those in the short-pulse cases. This can be due to lower initial perturbations. A heuristic wire array model suggests that the reduced perturbations, in the long-pulse cases, may be due to the individual wire merger occurring well before the acceleration of the shell. The experiments and modeling suggest that 150-200 ns implosion time Z-pinches could be employed for high-power, x-ray source applications.

  17. Extending the restricted nonlinear model for wall-turbulence to high Reynolds numbers

    Science.gov (United States)

    Bretheim, Joel; Meneveau, Charles; Gayme, Dennice

    2016-11-01

    The restricted nonlinear (RNL) model for wall-turbulence is motivated by the long-observed streamwise-coherent structures that play an important role in these flows. The RNL equations, derived by restricting the convective term in the Navier-Stokes equations, provide a computationally efficient approach due to fewer degrees of freedom in the underlying dynamics. Recent simulations of the RNL system have been conducted for turbulent channel flows at low Reynolds numbers (Re), yielding insights into the dynamical mechanisms and statistics of wall-turbulence. Despite the computational advantages of the RNL system, simulations at high Re remain out-of-reach. We present a new Large Eddy Simulation (LES) framework for the RNL system, enabling its use in engineering applications at high Re such as turbulent flows through wind farms. Initial results demonstrate that, as observed at moderate Re, restricting the range of streamwise varying structures present in the simulation (i.e., limiting the band of x Fourier components or kx modes) significantly affects the accuracy of the statistics. Our results show that only a few well-chosen kx modes lead to RNL turbulence with accurate statistics, including the mean profile and the well-known inner and outer peaks in energy spectra. This work is supported by NSF (WindInspire OISE-1243482).

  18. DNA copy number changes in high-grade malignant peripheral nerve sheath tumors by array CGH

    Directory of Open Access Journals (Sweden)

    Bjerkehagen Bodil

    2008-06-01

    Full Text Available Abstract Background Malignant peripheral nerve sheath tumors (MPNSTs are rare and highly aggressive soft tissue tumors showing complex chromosomal aberrations. In order to identify recurrent chromosomal regions of gain and loss, and thereby novel gene targets of potential importance for MPNST development and/or progression, we have analyzed DNA copy number changes in seven high-grade MPNSTs using microarray-based comparative genomic hybridization (array CGH. Results Considerable more gains than losses were observed, and the most frequent minimal recurrent regions of gain included 1q24.1-q24.2, 1q24.3-q25.1, 8p23.1-p12, 9q34.11-q34.13 and 17q23.2-q25.3, all gained in five of seven samples. The 17q23.2-q25.3 region was gained in all five patients with poor outcome and not in the two patients with disease-free survival. cDNA microarray analysis and quantitative real-time reverse transcription PCR were used to investigate expression of genes located within these regions. The gene lysyl oxidase-like 2 (LOXL2 was identified as a candidate target for the 8p23.1-p12 gain. Within 17q, the genes topoisomerase II-α (TOP2A, ets variant gene 4 (E1A enhancer binding protein, E1AF (ETV4 and baculoviral IAP repeat-containing 5 (survivin (BIRC5 showed increased expression in all samples compared to two benign tumors. Increased expression of these genes has previously been associated with poor survival in other malignancies, and for TOP2A, in MPNSTs as well. In addition, we have analyzed the expression of five micro RNAs located within the 17q23.2-q25.3 region, but none of them showed high expression levels compared to the benign tumors. Conclusion Our study shows the potential of using DNA copy number changes obtained by array CGH to predict the prognosis of MPNST patients. Although no clear correlations between the expression level and patient outcome were observed, the genes TOP2A, ETV4 and BIRC5 are interesting candidate targets for the 17q gain associated

  19. Heterozygous deletion at the RLN1 locus in a family with testicular germ cell cancer identified by integrating copy number variation data with phenome and interactome information

    DEFF Research Database (Denmark)

    Edsgard, Stefan Daniel; Scheel, M.; Hansen, Niclas Tue

    2011-01-01

    To search for disease‐related copy number variations (CNVs) in families with a high frequency of germ cell tumours (GCT), we analysed 16 individuals from four families by array comparative genomic hybridization (aCGH) and applied an integrative systems biology algorithm that prioritizes risk...

  20. Behaviour of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}-cathodes at high cycle numbers

    Energy Technology Data Exchange (ETDEWEB)

    Nikolowski, K.; Bramnik, N.N.; Ehrenberg, H.; Fuess, H. [Institute for Materials Science, Darmstadt University of Technology, Petersenstr. 23, D-64287 Darmstadt (Germany); Baehtz, C. [HASYLAB/DESY, Notkestr. 85, D-22607 Hamburg (Germany)

    2007-12-06

    In situ synchrotron diffraction experiments were performed to study the behaviour of the cathode material LiNi{sub 0.8}Co{sub 0.2}O{sub 2} at high cycle numbers. The battery-cell was cycled 140 times between 4.2 and 2.7 V. The initial cycle and several cycles at proceeded degradation of the cell were investigated. In between the cell was cycled ex situ. The evolution of the lattice parameters during cycling was determined for the different stages of degradation by means of Rietveld refinement. Comparing the initial cycle of the cell with the higher cycle numbers, the mechanism of lithium insertion/extraction does not change significantly. But, the range in which the lattice parameters change during one cycle becomes smaller. This can be attributed to interface layer formation and to slightly less lithium exchange in the same voltage window. (author)

  1. Genome-wide copy number profiling using high-density SNP array in chickens.

    Science.gov (United States)

    Yi, G; Qu, L; Chen, S; Xu, G; Yang, N

    2015-04-01

    Phenotypic diversity is a direct consequence resulting mainly from the impact of underlying genetic variation, and recent studies have shown that copy number variation (CNV) is emerging as an important contributor to both phenotypic variability and disease susceptibility. Herein, we performed a genome-wide CNV scan in 96 chickens from 12 diversified breeds, benefiting from the high-density Affymetrix 600 K SNP arrays. We identified a total of 231 autosomal CNV regions (CNVRs) encompassing 5.41 Mb of the chicken genome and corresponding to 0.59% of the autosomal sequence. The length of these CNVRs ranged from 2.6 to 586.2 kb with an average of 23.4 kb, including 130 gain, 93 loss and eight both gain and loss events. These CNVRs, especially deletions, had lower GC content and were located particularly in gene deserts. In particular, 102 CNVRs harbored 128 chicken genes, most of which were enriched in immune responses. We obtained 221 autosomal CNVRs after converting probe coordinates to Galgal3, and comparative analysis with previous studies illustrated that 153 of these CNVRs were regarded as novel events. Furthermore, qPCR assays were designed for 11 novel CNVRs, and eight (72.73%) were validated successfully. In this study, we demonstrated that the high-density 600 K SNP array can capture CNVs with higher efficiency and accuracy and highlighted the necessity of integrating multiple technologies and algorithms. Our findings provide a pioneering exploration of chicken CNVs based on a high-density SNP array, which contributes to a more comprehensive understanding of genetic variation in the chicken genome and is beneficial to unearthing potential CNVs underlying important traits of chickens. © 2015 Stichting International Foundation for Animal Genetics.

  2. Ground Boundary Conditions for Thermal Convection Over Horizontal Surfaces at High Rayleigh Numbers

    Science.gov (United States)

    Hanjalić, K.; Hrebtov, M.

    2016-07-01

    We present "wall functions" for treating the ground boundary conditions in the computation of thermal convection over horizontal surfaces at high Rayleigh numbers using coarse numerical grids. The functions are formulated for an algebraic-flux model closed by transport equations for the turbulence kinetic energy, its dissipation rate and scalar variance, but could also be applied to other turbulence models. The three-equation algebraic-flux model, solved in a T-RANS mode ("Transient" Reynolds-averaged Navier-Stokes, based on triple decomposition), was shown earlier to reproduce well a number of generic buoyancy-driven flows over heated surfaces, albeit by integrating equations up to the wall. Here we show that by using a set of wall functions satisfactory results are found for the ensemble-averaged properties even on a very coarse computational grid. This is illustrated by the computations of the time evolution of a penetrative mixed layer and Rayleigh-Bénard (open-ended, 4:4:1 domain) convection, using 10 × 10 × 100 and 10 × 10 × 20 grids, compared also with finer grids (e.g. 60 × 60 × 100), as well as with one-dimensional treatment using 1 × 1 × 100 and 1 × 1 × 20 nodes. The approach is deemed functional for simulations of a convective boundary layer and mesoscale atmospheric flows, and pollutant transport over realistic complex hilly terrain with heat islands, urban and natural canopies, for diurnal cycles, or subjected to other time and space variations in ground conditions and stratification.

  3. On the wave number 2 eastward propagating quasi 2 day wave at middle and high latitudes

    Science.gov (United States)

    Gu, Sheng-Yang; Liu, Han-Li; Pedatella, N. M.; Dou, Xiankang; Liu, Yu

    2017-04-01

    The temperature and wind data sets from the ensemble data assimilation version of the Whole Atmosphere Community Climate Model + Data Assimilation Research Testbed (WACCM + DART) developed at the National Center for Atmospheric Research (NCAR) are utilized to study the seasonal variability of the eastward quasi 2 day wave (QTDW) with zonal wave number 2 (E2) during 2007. The aliasing ratio of E2 from wave number 3 (W3) in the synoptic WACCM data set is a constant value of 4 × 10-6% due to its uniform sampling pattern, whereas the aliasing is latitudinally dependent if the WACCM fields are sampled asynoptically based on the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) sampling. The aliasing ratio based on SABER sampling is 75% at 40°S during late January, where and when W3 peaks. The analysis of the synoptic WACCM data set shows that the E2 is in fact a winter phenomenon, which peaks in the stratosphere and lower mesosphere at high latitudes. In the austral winter period, the amplitudes of E2 can reach 10 K, 20 m/s, and 30 m/s for temperature, zonal, and meridional winds, respectively. In the boreal winter period, the wave perturbations are only one third as strong as those in austral winter. Diagnostic analysis also shows that the mean flow instabilities in the winter upper mesosphere polar region provide sources for the amplification of E2. This is different from the westward QTDWs, whose amplifications are related to the summer easterly jet. In addition, the E2 also peaks at lower altitude than the westward modes.

  4. Hybrid RANS/LES method for high Reynolds numbers, applied to atmospheric flow over complex terrain

    DEFF Research Database (Denmark)

    Bechmann, Andreas; Sørensen, Niels N.; Johansen, Jeppe

    2007-01-01

      The use of Large-Eddy Simulation (LES) to predict wall-bounded flows has presently been limited to low Reynolds number flows. Since the number of computational grid points required to resolve the near-wall turbulent structures increase rapidly with Reynolds number, LES has been unattainable for...

  5. The effect of ileal interposition surgery on enteroendocrine cell numbers in the UC Davis type 2 diabetes mellitus rat

    DEFF Research Database (Denmark)

    Hansen, Carl Frederik; Vassiliadis, Efstathios; Vrang, Niels

    2014-01-01

    To investigate the short-term effect of ileal interposition (IT) surgery on gut morphology and enteroendocrine cell numbers in the pre-diabetic UC Davis type 2 diabetes mellitus (UCD-T2DM) rat.......To investigate the short-term effect of ileal interposition (IT) surgery on gut morphology and enteroendocrine cell numbers in the pre-diabetic UC Davis type 2 diabetes mellitus (UCD-T2DM) rat....

  6. Enhanced presence of NGF and mast cells number in nasal cavity after autologous stimulation: relation with sensorineural hearing deficit.

    Science.gov (United States)

    Salvinelli, F; Frari, V; Rocco, M L; Rosso, P; Aloe, L

    2015-01-01

    Nerve growth factor (NGF) is a neurotrophin which promote and regulate the survival of neurons in the peripheral nervous system. We aimed to evaluate the nasal NGF expressions of mast cells in healthy patients after stimulation with sterilized isotonic solution delivered at high pressure. The first part of the study was made with 21 voluntary individuals. The middle third of the inferior turbinate epithelial cells on the right nostril was scraped using a sterile curette and indicated as (pre), than a spray of sterilized isotonic solution at high pressure on the left nostril was delivered and 25 minutes later a similar stimulation was delivered on the same nostril. The stimulation was made with a specific spray. The middle third of the inferior turbinate epithelial cells on the left nostril was scraped using a sterile curette and indicated as (post). Forced nasal stress induced by local delivery of high pressure physiological solution causes an increase in the number of mast cells and enhances level of NGF in the nasal fluid compared to the control subjects. So based on the first part of our study, since NGF is universally known as effective in protection and repairing of neural cells damage, we started the second part and gave a treatment on the same patients, to increase NGF levels with a six months daily therapy and observed the variations in Sensorineural Hearing Loss (SNHL) and tinnitus intensity from the beginning to the end of the therapy. All patients received sterilized isotonic solution at high pressure (pression emission level: PEL): 7 g/sec for 0.5 sec (emission time: ET) in both nostrils. 25 minutes later a similar stimulation was delivered twice a day. The control group (21 pts) received normal therapy with betahistine dihydrochloride 16 mg twice a day. Upon acuphenometry, there was a lower intensity of tinnitus and the improvement was signaled by the patients. Patients with SNHL treated with conventional therapy had a slight worsening, while the

  7. Histone Deacetylase Inhibitors Reduce the Number of Herpes Simplex Virus-1 Genomes Initiating Expression in Individual Cells

    Science.gov (United States)

    Shapira, Lev; Ralph, Maya; Tomer, Enosh; Cohen, Shai; Kobiler, Oren

    2016-01-01

    Although many viral particles can enter a single cell, the number of viral genomes per cell that establish infection is limited. However, mechanisms underlying this restriction were not explored in depth. For herpesviruses, one of the possible mechanisms suggested is chromatinization and silencing of the incoming genomes. To test this hypothesis, we followed infection with three herpes simplex virus 1 (HSV-1) fluorescence expressing recombinants in the presence or absence of histone deacetylases inhibitors (HDACi’s). Unexpectedly, a lower number of viral genomes initiated expression in the presence of these inhibitors. This phenomenon was observed using several HDACi: Trichostatin A (TSA), Suberohydroxamic Acid, Valporic Acid, and Suberoylanilide Hydroxamic Acid. We found that HDACi presence did not change the progeny outcome from the infected cells but did alter the kinetic of the gene expression from the viral genomes. Different cell types (HFF, Vero, and U2OS), which vary in their capability to activate intrinsic and innate immunity, show a cell specific basal average number of viral genomes establishing infection. Importantly, in all cell types, treatment with TSA reduced the number of viral genomes. ND10 nuclear bodies are known to interact with the incoming herpes genomes and repress viral replication. The viral immediate early protein, ICP0, is known to disassemble the ND10 bodies and to induce degradation of some of the host proteins in these domains. HDACi treated cells expressed higher levels of some of the host ND10 proteins (promyelocytic leukemia and ATRX), which may explain the lower number of viral genomes initiating expression per cell. Corroborating this hypothesis, infection with three HSV-1 recombinants carrying a deletion in the gene coding for ICP0, show a reduction in the number of genomes being expressed in U2OS cells. We suggest that alterations in the levels of host proteins involved in intrinsic antiviral defense may result in

  8. Histone deacetylase inhibitors reduce the number of herpes simplex virus-1 genomes initiating expression in individual cells

    Directory of Open Access Journals (Sweden)

    Lev Shapira

    2016-12-01

    Full Text Available Although many viral particles can enter a single cell, the number of viral genomes per cell that establish infection is limited. However, mechanisms underlying this restriction were not explored in depth. For herpesviruses, one of the possible mechanisms suggested is chromatinization and silencing of the incoming genomes. To test this hypothesis, we followed infection with three herpes simplex virus 1 (HSV-1 fluorescence-expressing recombinants in the presence or absence of histone deacetylases inhibitors (HDACi’s. Unexpectedly, a lower number of viral genomes initiated expression in the presence of these inhibitors. This phenomenon was observed using several HDACi: Trichostatin A (TSA, Suberohydroxamic Acid (SBX, Valporic Acid (VPA and Suberoylanilide Hydoxamic Acid (SAHA. We found that HDACi presence did not change the progeny outcome from the infected cells but did alter the kinetic of the gene expression from the viral genomes. Different cell types (HFF, Vero and U2OS, which vary in their capability to activate intrinsic and innate immunity, show a cell specific basal average number of viral genomes establishing infection. Importantly, in all cell types, treatment with TSA reduced the number of viral genomes. ND10 nuclear bodies are known to interact with the incoming herpes genomes and repress viral replication. The viral immediate early protein, ICP0, is known to disassemble the ND10 bodies and to induce degradation of some of the host proteins in these domains. HDACi treated cells expressed higher levels of some of the host ND10 proteins (PML and ATRX, which may explain the lower number of viral genomes initiating expression per cell. Corroborating this hypothesis, infection with three HSV-1 recombinants carrying a deletion in the gene coding for ICP0, show a reduction in the number of genomes being expressed in U2OS cells. We suggest that alterations in the levels of host proteins involved in intrinsic antiviral defense may result in

  9. Carbon-Nanotubes-Supported Pd Nanoparticles for Alcohol Oxidations in Fuel Cells: Effect of Number of Nanotube Walls on Activity.

    Science.gov (United States)

    Zhang, Jin; Lu, Shanfu; Xiang, Yan; Shen, Pei Kang; Liu, Jian; Jiang, San Ping

    2015-09-07

    Carbon nanotubes (CNTs) are well known electrocatalyst supports due to their high electrical conductivity, structural stability, and high surface area. Here, we demonstrate that the number of inner tubes or walls of CNTs also have a significant promotion effect on the activity of supported Pd nanoparticles (NPs) for alcohol oxidation reactions of direct alcohol fuel cells (DAFCs). Pd NPs with similar particle size (2.1-2.8 nm) were uniformly assembled on CNTs with different number of walls. The results indicate that Pd NPs supported on triple-walled CNTs (TWNTs) have the highest mass activity and stability for methanol, ethanol, and ethylene glycol oxidation reactions, as compared to Pd NPs supported on single-walled and multi-walled CNTs. Such a specific promotion effect of TWNTs on the electrocatalytic activity of Pd NPs is not related to the contribution of metal impurities in CNTs, oxygen-functional groups of CNTs or surface area of CNTs and Pd NPs. A facile charge transfer mechanism via electron tunneling between the outer wall and inner tubes of CNTs under electrochemical driving force is proposed for the significant promotion effect of TWNTs for the alcohol oxidation reactions in alkaline solutions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The total number of Leydig and Sertoli cells in the testes of men across various age groups - a stereological study

    DEFF Research Database (Denmark)

    Petersen, Peter M; Seierøe, Karina; Pakkenberg, Bente

    2015-01-01

    The aim of this study was to estimate the total number of Sertoli and Leydig cells in testes from male subjects across the human lifespan, using an optimized stereological method for cell-counting. In comparison with many other organs, estimation of the total cell numbers in the testes...... is particularly sensitive to methodological problems. Therefore, using the optical fractionator technique and a sampling design specifically optimized for human testes, we estimated the total number of Sertoli and Leydig cells in the testes from 26 post mortem male subjects ranging in age from 16 to 80 years....... The mean unilateral total number of Sertoli cells was 407 × 10(6) [range: 86 × 10(6) to 665 × 10(6) , coefficient of variation (CV) = 0.33], and the mean unilateral total number of Leydig cells was 99 × 10(6) (range: 47 × 10(6) to 245 × 10(6) , CV = 0.48). There was a significant decline in the number...

  11. Western blot analysis of a limited number of cells: a valuable adjunct to proteome analysis of paraffin wax-embedded, alcohol-fixed tissue after laser capture microdissection.

    Science.gov (United States)

    Martinet, Wim; Abbeloos, Vanessa; Van Acker, Nathalie; De Meyer, Guido R Y; Herman, Arnold G; Kockx, Mark M

    2004-03-01

    In recent years, laser capture microdissection (LCM) has been used successfully to obtain distinct populations of cells for subsequent molecular analysis. Because of the limited sample availability and the absence of in vitro amplification steps for proteins, the use of LCM for proteome analysis largely depends on highly sensitive protein detection methods. In this study, a western blot protocol was developed and validated for the detection of beta-actin and the moderately expressed cell death protein caspase-3 in small numbers of cells. Initially, cultured human U937 monocytes and whole sections of paraffin wax-embedded, alcohol-fixed human tonsils were used to optimize protein electrophoresis and western blotting conditions. High-performance NuPAGE Bis-Tris gels in combination with high-quality transfer membranes, optimized antibody concentrations, and a sensitive chemiluminescent substrate provided a strong signal for beta-actin with approximately 500 U937 cells. In the same way, procaspase-3 could be identified with approximately 1000 cells. Similar results were obtained with germinal centre cells that were procured from paraffin wax-embedded, alcohol-fixed human tonsils by LCM. Treatment of U937 cells with etoposide rapidly induced cell death and allowed the detection of active caspase-3 with approximately 2500 cells (0.8 pg of protein). The findings of this study suggest that western blotting is a valuable adjunct to proteome analysis of LCM procured cells.

  12. Clonal Expansion of Lgr5-Positive Cells from Mammalian Cochlea and High-Purity Generation of Sensory Hair Cells

    Directory of Open Access Journals (Sweden)

    Will J. McLean

    2017-02-01

    Full Text Available Death of cochlear hair cells, which do not regenerate, is a cause of hearing loss in a high percentage of the population. Currently, no approach exists to obtain large numbers of cochlear hair cells. Here, using a small-molecule approach, we show significant expansion (>2,000-fold of cochlear supporting cells expressing and maintaining Lgr5, an epithelial stem cell marker, in response to stimulation of Wnt signaling by a GSK3β inhibitor and transcriptional activation by a histone deacetylase inhibitor. The Lgr5-expressing cells differentiate into hair cells in high yield. From a single mouse cochlea, we obtained over 11,500 hair cells, compared to less than 200 in the absence of induction. The newly generated hair cells have bundles and molecular machinery for transduction, synapse formation, and specialized hair cell activity. Targeting supporting cells capable of proliferation and cochlear hair cell replacement could lead to the discovery of hearing loss treatments.

  13. Multiplexed labeling system for high-throughput cell sorting.

    Science.gov (United States)

    Shin, Seung Won; Park, Kyung Soo; Song, In Hyun; Shin, Woo Jung; Kim, Byung Woo; Kim, Dong-Ik; Um, Soong Ho

    2016-09-01

    Flow cytometry and fluorescence activated cell sorting techniques were designed to realize configurable classification and separation of target cells. A number of cell phenotypes with different functionalities have recently been revealed. Before simultaneous selective capture of cells, it is desirable to label different samples with the corresponding dyes in a multiplexing manner to allow for a single analysis. However, few methods to obtain multiple fluorescent colors for various cell types have been developed. Even when restricted laser sources are employed, a small number of color codes can be expressed simultaneously. In this study, we demonstrate the ability to manifest DNA nanostructure-based multifluorescent colors formed by a complex of dyes. Highly precise self-assembly of fluorescent dye-conjugated oligonucleotides gives anisotropic DNA nanostructures, Y- and tree-shaped DNA (Y-DNA and T-DNA, respectively), which may be used as platforms for fluorescent codes. As a proof of concept, we have demonstrated seven different fluorescent codes with only two different fluorescent dyes using T-DNA. This method provides maximum efficiency for current flow cytometry. We are confident that this system will provide highly efficient multiplexed fluorescent detection for bioanalysis compared with one-to-one fluorescent correspondence for specific marker detection.

  14. High Temperature PEM Fuel Cells and Organic Fuels

    DEFF Research Database (Denmark)

    Vassiliev, Anton

    such an opportunity. Some knowledge about the electrooxidation of DME is available, together with its limited use in low temperature PEM fuel cells, where the low temperature poses an obstacle in the form of phase separation in the fuel supply, making the cells less effective and reducing the amount of power...... harvested from the cells. This is completely avoided at the elevated temperatures with the additional benefit of increased kinetics. In the presented work an experimental setup for testing direct dimethyl ether high temperature fuel cells is described, proposing a novel design of an evaporator for a burst...... evaporated liquid stream supply to either of the electrodes. A large number of MEAs with different component compositions have been prepared and tested in different conditions using the constructed setups to obtain a basic understanding of the nature of direct DME HT-PEM FC, to map the processes occurring...

  15. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... of dissolved oxygen. A potential step method (hydrodynamic chronocoulometry) is evaluated for simultaneous measurement of diffusivity and solubility of oxygen by means of RDE. Finally, the ORR tests are extended to conc. H3PO4 at more relevant working temperatures and under increased oxygen pressure. Direct...... of platinumphosphoric acid. At room temperature, a relative slow ORR hindering process is active, which requires using a fast method (cyclic voltammetry with high scan rate / hydrodynamic chronocoulometry) to accurately measure the diffusion limited currents, and thus, oxygen diffusivity and solubility. In conc. H3PO4...

  16. Estimating the number of hematopoietic or lymphoid stem cells giving rise to clonal chromosome aberrations in blood T lymphocytes.

    Science.gov (United States)

    Nakano, M; Kodama, Y; Ohtaki, K; Itoh, M; Awa, A A; Cologne, J; Kusunoki, Y; Nakamura, N

    2004-03-01

    Quantifying the proliferative capacity of long-term hematopoietic stem cells in humans is important for bone marrow transplantation and gene therapy. Obtaining appropriate data is difficult, however, because the experimental tools are limited. We hypothesized that tracking clonal descendants originating from hematopoietic stem cells would be possible if we used clonal chromosome aberrations as unique tags of individual hematopoietic stem cells in vivo. Using FISH, we screened 500 blood T lymphocytes from each of 513 atomic bomb survivors and detected 96 clones composed of at least three cells with identical aberrations. The number of clones was inversely related to their population size, which we interpreted to mean that the progenitor cells were heterogeneous in the number of progeny that they could produce. The absolute number of progenitor cells contributing to the formation of the observed clones was estimated as about two in an unexposed individual. Further, scrutiny of ten clones revealed that lymphocyte clones could originate roughly equally from hematopoietic stem cells or from mature T lymphocytes, thereby suggesting that the estimated two progenitor cells are shared as one hematopoietic stem cell and one mature T cell. Our model predicts that one out of ten people bears a non- aberrant clone comprising >10% of the total lymphocytes, which indicates that clonal expansions are common and probably are not health-threatening.

  17. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  18. Using Computational Fluid Dynamics and Experiments to Design Sweeping Jets for High Reynolds Number Cruise Configurations

    Science.gov (United States)

    Jones, Gregory S.; Milholen, William E., II; Fell, Jared S.; Webb, Sandy R.; Cagle, C. Mark

    2016-01-01

    The application of a sweeping jet actuator to a circulation control system was initiated by a risk reduction series of experiments to optimize the authority of a single sweeping jet actuator. The sweeping jet design was integrated into the existing Fundamental Aerodynamic Subsonic Transonic- Modular Active Control (FAST-MAC) model by replacing the steady blowing system with an array of thirty-nine sweeping jet cartridges. A constant slot height to wing chord ratio was similar to the steady blowing configuration resulting in each actuator having a unique in size for the sweeping jet configuration. While this paper will describe the scaling and optimization of the actuators for future high Reynolds number applications, the major focus of this effort was to target the transonic flight regime by increasing the amplitude authority of the actuator. This was accomplished by modifying the diffuser of the sweeping jet actuator, and this paper highlights twelve different diffuser designs. The experimental portion of this work was completed in the NASA Langley National Transonic Facility.

  19. Triple-deck analysis of transonic high Reynolds number flow through slender channels.

    Science.gov (United States)

    Kluwick, A; Kornfeld, M

    2014-07-28

    In this work, laminar transonic weakly three-dimensional flows at high Reynolds numbers in slender channels, as found in microsupersonic nozzles and turbomachines of micro-electro-mechanical systems, are considered. The channel height is taken so small that the viscous wall layers forming at the channel walls start to interact strongly rather than weakly with the inviscid core flow and, therefore, the classical boundary layer approach fails. The resulting viscous-inviscid interaction problem is formulated using matched asymptotic expansions and found to be governed by a triple-deck structure. As a consequence, the properties of the predominantly inviscid core region and the viscous wall layers have to be calculated simultaneously in the interaction region. Weakly three-dimensional effects caused by surface roughness, upstream propagating flow perturbations, boundary layer separation as well as bifurcating solutions are discussed. Representative results for subsonic as well as supersonic conditions are presented, and the importance of these flow phenomena in technical applications as, for example, a means to reduce shock losses through the use of deformed geometry is addressed.

  20. High Reynolds number rough wall turbulent boundary layer experiments using Braille surfaces

    Science.gov (United States)

    Harris, Michael; Monty, Jason; Nova, Todd; Allen, James; Chong, Min

    2007-11-01

    This paper details smooth, transitional and fully rough turbulent boundary layer experiments in the New Mexico State high Reynolds number rough wall wind tunnel. The initial surface tested was generated with a Braille printer and consisted of an uniform array of Braille points. The average point height being 0.5mm, the spacing between the points in the span was 0.5mm and the surface consisted of span wise rows separated by 4mm. The wavelength to peak ratio was 8:1. The boundary layer thickness at the measurement location was 190mm giving a large separation of roughness height to layer thickness. The maximum friction velocity was uτ=1.5m/s at Rex=3.8 x10^7. Results for the skin friction co-efficient show that this surface follows a Nikuradse type inflectional curve and that Townsends outer layer similarity hypothesis is valid for rough wall flows with a large separation of scales. Mean flow and turbulence statistics will be presented.

  1. Dynamic non-equilibrium wall-modeling for large eddy simulation at high Reynolds numbers

    Science.gov (United States)

    Kawai, Soshi; Larsson, Johan

    2013-01-01

    A dynamic non-equilibrium wall-model for large-eddy simulation at arbitrarily high Reynolds numbers is proposed and validated on equilibrium boundary layers and a non-equilibrium shock/boundary-layer interaction problem. The proposed method builds on the prior non-equilibrium wall-models of Balaras et al. [AIAA J. 34, 1111-1119 (1996)], 10.2514/3.13200 and Wang and Moin [Phys. Fluids 14, 2043-2051 (2002)], 10.1063/1.1476668: the failure of these wall-models to accurately predict the skin friction in equilibrium boundary layers is shown and analyzed, and an improved wall-model that solves this issue is proposed. The improvement stems directly from reasoning about how the turbulence length scale changes with wall distance in the inertial sublayer, the grid resolution, and the resolution-characteristics of numerical methods. The proposed model yields accurate resolved turbulence, both in terms of structure and statistics for both the equilibrium and non-equilibrium flows without the use of ad hoc corrections. Crucially, the model accurately predicts the skin friction, something that existing non-equilibrium wall-models fail to do robustly.

  2. Linear drag law for high-Reynolds-number flow past an oscillating body

    Science.gov (United States)

    Agre, Natalie; Childress, Stephen; Zhang, Jun; Ristroph, Leif

    2016-07-01

    An object immersed in a fast flow typically experiences fluid forces that increase with the square of speed. Here we explore how this high-Reynolds-number force-speed relationship is affected by unsteady motions of a body. Experiments on disks that are driven to oscillate while progressing through air reveal two distinct regimes: a conventional quadratic relationship for slow oscillations and an anomalous scaling for fast flapping in which the time-averaged drag increases linearly with flow speed. In the linear regime, flow visualization shows that a pair of counterrotating vortices is shed with each oscillation and a model that views a train of such dipoles as a momentum jet reproduces the linearity. We also show that appropriate scaling variables collapse the experimental data from both regimes and for different oscillatory motions into a single drag-speed relationship. These results could provide insight into the aerodynamic resistance incurred by oscillating wings in flight and they suggest that vibrations can be an effective means to actively control the drag on an object.

  3. Time evolution of atmospheric particle number concentration during high-intensity pyrotechnic events

    Science.gov (United States)

    Crespo, Javier; Yubero, Eduardo; Nicolás, Jose F.; Caballero, Sandra; Galindo, Nuria

    2014-10-01

    The Mascletàs are high-intensity pyrotechnic events, typical of eastern Spanish festivals, in which thousands of firecrackers are burnt at ground level in an intense, short-time (festival in Alicante (southeastern Spain). Peak concentrations and dilution times observed throughout the Mascletàs have been compared to those measured when conventional aerial fireworks were launched 2 km away from the monitoring site. The impact of the Mascletàs on the total number concentration of particles larger than 0.3 μm was higher (maximum ˜2·104 cm-3) than that of fireworks (maximum ˜2·103 cm-3). The effect of fireworks depended on whether the dominant meteorological conditions favoured the transport of the plume to the measurement location. However, the time required for particle concentrations to return to background levels is longer and more variable for firework displays (minutes to hours) than for the Mascletàs (<25 min).

  4. Structure Functions in Wall-bounded Flows at High Reynolds Number