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Sample records for hot cell environment

  1. Effects of cold-damp and hot-damp environment on VEGF and IL-1 expression in joint cartilage cells in adjuvant arthritis in rats.

    Science.gov (United States)

    Bai, Yun-Jing; Jiang, De-xun; An, Na; Shen, Hong-bo; Hu, Yin-qi

    2012-06-01

    To study the effects of environmental factors on the degree of injury and expression of vascular endothelial growth factor (VEGF) and interleukin-1 (IL-1) in cartilage cells of the joint in a rat model of adjuvant arthritis (AA). SD rats aged 10 months were randomly divided into 4 groups that varied by temperature and humidity housing conditions and induction of AA: a control group, a model group, a cold-damp group, and a hot-damp group. All groups except the control group were induced with AA. After 4 w, VEGF and IL-1 expression in cartilage cells of ankle joints of hind limbs were observed. Mean area, optical density, and numbers of VEGF- and IL-1-positive cells in the model group, the cold-damp group, and the hot-damp group were significantly higher than that of the control group (all P damp group and the hot-damp group were significantly higher than that of the model group (all P damp group were significantly higher than that of the cold-damp group. Bone in the hot-damp and cold-damp groups was severely injured. Environmental factors such as high humidity combined with either high or low temperature increase the severity of damage and expression of VEGF and IL-1 in cartilage cells of joints in rats induced with AA.

  2. Sealed source dismantling hot cell - startup

    Energy Technology Data Exchange (ETDEWEB)

    Dellamano, Jose Claudio; Ferreira, Robson de Jesus, E-mail: jcdellam@ipen.br, E-mail: rojefer@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Rejeitos radioativos

    2013-07-01

    Sealed radioactive sources are widely used in many applications of nuclear technology and at the end of the useful life, most sources become radioactive waste. In Brazil, this waste is received by the Institutes of the National Nuclear Energy Commission and kept under centralized storage. The Waste Management Department at the Nuclear and Energy Research Institute is the main storage center, having received around 20,000 disused sources. A hot cell was designed and constructed to manage Co-60 spent sealed sources with activity up to 3.7 10{sup 1}0 Bq and other sources with equivalent activities. In the hot cell the sources are withdraw from their original shielding and transferred to a standard shielding for further disposal off. The original shielding disassembling is made outside the hot cell and after opening, it is transferred inside the hot cell and the sealed source is removed remotely. The source is checked in relation to external contamination and its activity is checked. After this, the source is positioned in the standard shielding located inside an overpack at the bottom of the hot cell. This paper describes some pre-operational tests carried out in it, that include: opening and closing doors and locks, checking of all electrical and pneumatic controls, the original shielding movement inside the hot-cell, dose rate measurements outside the hot-cell, insertion of the sealed sources inside the activity meter chamber, transferring the sealed source to the standard shielding, movement of the overpack with the standard shielding to outside of the hot-cell and plugging of the standard shielding. (author)

  3. WESF hot cells waste minimization criteria hot cells window seals evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Walterskirchen, K.M.

    1997-03-31

    WESF will decouple from B Plant in the near future. WESF is attempting to minimize the contaminated solid waste in their hot cells and utilize B Plant to receive the waste before decoupling. WESF wishes to determine the minimum amount of contaminated waste that must be removed in order to allow minimum maintenance of the hot cells when they are placed in ''laid-up'' configuration. The remaining waste should not cause unacceptable window seal deterioration for the remaining life of the hot cells. This report investigates and analyzes the seal conditions and hot cell history and concludes that WESF should remove existing point sources, replace cerium window seals in F-Cell and refurbish all leaded windows (except for A-Cell). Work should be accomplished as soon as possible and at least within the next three years.

  4. Impact of hot environment on colostrum and milk composition.

    Science.gov (United States)

    Bernabucci, U; Basiricò, L; Morera, P

    2013-11-03

    Under hot and warm environments productivity and reproduction efficiency of farm and wild animals are negatively affected. The negative effects of hot environments on animal health are responsible for the alteration of colostrum and milk production in term of quantity and quality. Colostrum and milk are nutrient-rich fluids secreted by the mammary gland of female mammals after giving birth and during growth and development of the young. Multiple factors influence the production and the composition of colostrum and milk, including species, breed, health status, feeding practices and environmental conditions. Colostrum and milk are not only a good source of macronutrients and micronutrients, but contains many biologically-active constituents. Colostrum and milk of various species differ widely in amounts and proportions of their principal constituents, especially comparing monogastric with ruminant animals because of the difference between their physiology and digestion. The interspecies variations in part reflect different adaptive strategies to environmental conditions and selective pressures of various species during the evolution. A limited number of studies documented the effects of hot condition on modification of colostrum and milk quality, in particular referred to nutrients and immunoglobulin composition, but no information are available on the effects of hot environment on nutraceutical properties and bioactive molecules content of colostrum and milk.

  5. Verification survey of buildings 200 hot cells

    Energy Technology Data Exchange (ETDEWEB)

    Sholeen, C.M.

    1996-03-01

    At the start of this D&D project, the decontamination goals were set at (1) reducing the stack emissions to 10% of the 1991 emissions; (2) reducing the exposure rate in each cell to < 1 mR/h; and (3) reducing the removable contamination to none detectable. Since the contamination can be fixed with paint, the other two goals were given priority. The estimate of the 1995 emissions from K-3 was 20% of the 1991 emissions estimate. However, the 1996 estimates are {approximately}9% of the 1991 emissions estimate. Since in 1991 the K-3 emissions were only 1/2% of the emissions from M-1, even the 20% reduction has little effect on the project reduction. The total emissions have been reduce to {approximately}2 1/4% of the 1991 emissions from the 5 hot cells that were decontaminated. The emissions and exposure rates are presented in Table I below. Cells A-1 and M-1 exceed the exposure rate criteria. For the other cells, the general exposure rate in the middle of the cell meets the criteria. However, near the prefilters, the exposure rates increase. Cell M-1 has extensive floor contamination that penetrated to a 6 inch depth. At 30 cm above the floor, the exposure rate through the lead blanket is 50 mR/h. A more detailed list of acceptance criteria were specified before the final verification survey. Table ii compares the maximum survey results on the wall or floor surface of each cell to these criteria. Cells M-1 and A-1 frequently fail to meet these criteria.

  6. Hot Cell Facility (HCF) Safety Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    MITCHELL,GERRY W.; LONGLEY,SUSAN W.; PHILBIN,JEFFREY S.; MAHN,JEFFREY A.; BERRY,DONALD T.; SCHWERS,NORMAN F.; VANDERBEEK,THOMAS E.; NAEGELI,ROBERT E.

    2000-11-01

    This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood of these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are described. Additionally, information which describes the safety management programs at SNL are described in ancillary chapters of the SAR.

  7. Multifunctional design of footwear for hot environment condition

    Science.gov (United States)

    Dragcevic, Z.; Vujasinovic, E.; Hursa Sajatovic, A.

    2017-10-01

    For some time design of a new product is not connected only with aesthetic, artistic appearance but moreover with functionality and engineering (from rightful selection of materials, construction, and technological concept to prototyping). One good example of this is design of multifunctional footwear as well as hiking footwear, footwear for soldiers, police officers, first responders etc. All mentioned kinds of footwear have lot of specific requirements to fulfil starting from maintaining and enhancing mobility to maximizing protection and eliminating or minimizing the risk for the wearer. Therefore, designing appropriate footwear represents a great challenge not only for designers but for engineers as well. Having that entire in mind few years ago, Faculty of Textile Technology University of Zagreb started the research with the aim to develop 21st century multifunctional footwear for e.g. military, police, first respondents or any special human forces for different weather environment. The paper presents how it was done in the case of boots for hot environment conditions

  8. Hot environments decrease exercise capacity and elevate multiple neurotransmitters.

    Science.gov (United States)

    Zhao, Jiexiu; Lai, Lili; Cheung, Stephen S; Cui, Shuqiang; An, Nan; Feng, Wenping; Lorenzo, Santiago

    2015-11-15

    This study aimed to test the hypothesis that different neurotransmitters and hormones are presented at exercise fatigue in hot temperatures with differing relative humidities (RH). Eight trained male athletes performed a graded maximum oxygen consumption (VO2max) test in five different environmental conditions, namely, 21°C/20% RH (Normal), 33°C/20% RH (Hot 20%), 33°C/40% RH (Hot 40%), 33°C/60% RH (Hot 60%), and 33°C/80% RH (Hot 80%). Blood samples were taken pre- and post-exercise and analyzed for noradrenaline (NA), adrenaline (ADR), dopamine (DA), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and prolactin (PRL). Weight and oral and skin temperatures were recorded pre- and post-exercise. Heart rate was continuously monitored throughout the exercise. Hot 20%, Hot 40%, and Hot 80% had lower VO2max levels compared with Normal (Pneurotransmitter level irrespective of the environmental conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Hot Corrosion Studies in Coal Fired Boiler Environment

    Directory of Open Access Journals (Sweden)

    Kamal Subhash

    2014-07-01

    Full Text Available Hot corrosion behaviour of the bare and D-gun coated superfer 800H exposed to low temperature super-heater zone of the coal fired boiler of Guru Nanak Dev Thermal Power Plant, Bathinda, Punjab, India. The specimens were hanged in the platen super-heater of coal fired boiler where the gas temperature was around 900 °C ±10 °C. Hot corrosion experiments were performed for 10 cycles, each cycle consisting of 100 hours exposure followed by 1 hour cooling at ambient temperature. Weight change measurements were done at the end of each cycle. The weight change data used for predicting hot corrosion behaviour of the coated alloys after the total exposure of 1000 hours. The different phases and their distribution in the hot corroded specimens were analysed with the help of FE-SEM/EDS and X-ray mapping.

  10. Design Report for ACP Hot Cell Rear Door

    Energy Technology Data Exchange (ETDEWEB)

    Ku, J. H.; Kwon, K. C.; Choung, W. M.; Cho, I. J.; Kook, D. H.; Lee, W. K.; You, G. S.; Lee, E. P.; Park, S. W

    2005-12-15

    A hot-cell facility was constructed at the IMEF building for the demonstrate ACP process. ACP hot-cell consists of process cell and maintenance cell, and each cell has rear door. Since this facility was constructed at basement floor, all process materials, equipment and radioactive materials are take in and out through the rear door. Also, this door can be an access route of workers for the maintenance works. Therefore ACP hot-cell rear doors must maintain the radiation shielding, sealing, mechanical and structural safety. This report presents design criteria, design contents of each part and driving part. It was confirmed that the rear doors sufficiently maintain the safety through the structural analysis and shielding analysis. Also, it was confirmed that the rear doors were constructed as designed by the gamma scanning test after the installation.

  11. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    OSCAR,DEBBY S.; WALKER,SHARON ANN; HUNTER,REGINA LEE; WALKER,CHERYL A.

    1999-12-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2.

  12. Hot plasma environment at Jupiter - Voyager 2 results

    Science.gov (United States)

    Krimigis, S. M.; Bostrom, C. O.; Keath, E. P.; Zwickl, R. D.; Carbary, J. F.; Armstrong, T. P.; Axford, W. I.; Fan, C. Y.; Gloeckler, G.; Lanzerotti, L. J.

    1979-01-01

    Preliminary results are reported from measurements made with the low-energy charged particle (LECP) instrument on Voyager 2 as it approached and traversed the Jovian magnetosphere. The primary objectives of the LECP instrument were to make measurements of the hot plasma (no less than about 20 keV and no less than about 28 keV for electrons and ions, respectively), to characterize the composition of the hot plasma and energetic-particle population, and to determine the particle flows and spatial distributions. In addition, the effects associated with the possible wake of Ganymede are discussed. Attention is given to inbound and outbound passes, along with Jovian plasma characteristics. The results suggest that the Jovian magnetosphere is confined by a plasma boundary rather than a conventional magnetopause. Inside the plasma boundary there exists a discontinuity at about 50-60 Jupiter radii, and the region inside this discontinuity is termed the 'inner plasmasphere'.

  13. Stress analysis for wall structure in mobile hot cell design

    Energy Technology Data Exchange (ETDEWEB)

    Bahrin, Muhammad Hannan, E-mail: hannan@nuclearmalaysia.gov.my; Rahman, Anwar Abdul, E-mail: anwar@nuclearmalaysia.gov.my; Hamzah, Mohd Arif, E-mail: arif@nuclearmalaysia.gov.my; Mamat, Mohd Rizal; Azman, Azraf; Hasan, Hasni [Prototype and Plant Development Centre, Technical Services Division, Malaysian Nuclear Agency (Malaysia)

    2016-01-22

    Malaysian Nuclear Agency is developing a Mobile Hot Cell (MHC) in order to handle and manage Spent High Activity Radioactive Sources (SHARS) such as teletherapy heads and irradiators. At present, there are only two units of MHC in the world, in South Africa and China. Malaysian Mobile Hot cell is developed by Malaysian Nuclear Agency with the assistance of IAEA expert, based on the design of South Africa and China, but with improved features. Stress analysis has been performed on the design in order to fulfil the safety requirement in operation of MHC. This paper discusses the loading analysis effect from the sand to the MHC wall structure.

  14. The hot plasma environment at Jupiter - Ulysses results

    Science.gov (United States)

    Lanzerotti, L. J.; Armstrong, T. P.; Gold, R. E.; Anderson, K. A.; Krimigis, S. M.; Lin, R. P.; Pick, M.; Roelof, E. C.; Sarris, E. T.; Simnett, G. M.

    1992-01-01

    Initial results obtained from measurements made by the HI-SCALE (heliosphere instrument for spectra, composition, and anisotropy at low energies) experiment are reported. Data revealed that the Jovian magnetosphere is very extended, with the day-side magnetopause located at about 105 Jupiter radii. The relative abundances of sulfur, oxygen, and sodium to helium decreased with the decreasing radial distance from the planet on the day-side, which suggests that the abundances of Jupiter-derived species are dependent on latitude. Intense fluxes of counter-streaming ions and electrons were discovered in the dusk-side, high-latitude region from the edge of the plasma sheet to the dusk-side magnetopause. These beams of ions and electrons appeared to be very tightly aligned with the magnetic field and to be superimposed on a time- and space variable isotropic hot plasma background. The current carried by measured hot plasma particles are about 1.6 x 10 exp -4 microamps per sq m.

  15. High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

    Directory of Open Access Journals (Sweden)

    Tian Qin

    Full Text Available BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE and sequence-based typing (SBT were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01. The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01. Legionella pneumophila was the most frequently isolated species (98.9%, and the isolated serogroups included serogroups 3 (25.3%, 6 (23.4%, 5 (19.2%, 1 (18.5%, 2 (10.2%, 8 (0.4%, 10 (0.8%, 9 (1.9% and 12 (0.4%. Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control

  16. High Prevalence, Genetic Diversity and Intracellular Growth Ability of Legionella in Hot Spring Environments

    Science.gov (United States)

    Zhou, Haijian; Wang, Huanxin; Xu, Ying; Zhao, Mingqiang; Guan, Hong; Li, Machao; Shao, Zhujun

    2013-01-01

    Background Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. Methods Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. Results Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (pLegionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (pLegionella pneumophila was the most frequently isolated species (98.9%), and the isolated serogroups included serogroups 3 (25.3%), 6 (23.4%), 5 (19.2%), 1 (18.5%), 2 (10.2%), 8 (0.4%), 10 (0.8%), 9 (1.9%) and 12 (0.4%). Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. Conclusions Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control and prevention strategies are

  17. Exercises in hot and humid environment caused liver injury in a rat model.

    Directory of Open Access Journals (Sweden)

    DongLiang Li

    Full Text Available To investigate injury pattern during intense exercises in hot and humid environment particularly on liver in a rat exertional heat stroke model.We randomly divided 30 rats into a control group (CG, a normal temperature (25±2°C, 60%±5% humidity exercise group (NTEG and a high temperature and high humidity (35±2°C, 80%±10% humidity exercising group (HTEG, each comprising 10 animals. The NTEG and HTEG rats were forced to run in a treadmill for 1 hour maximum at 20 rpm. We analyzed liver cells of all three groups with JC-1 dye and flow cytometry for apoptosis rates in addition to liver tissue 8 - hydroxy deoxyguanosine (8 - OhdG and blood serum IL-6, tumor necrosis factor alpha (TNF-α, alanine aminotransferase ALT, aspartate amino transferase (AST, serum creatinine (CREA, blood urea nitrogen (BUN, lactate dehydrogenase (LDH, creatine phosphate kinase (CK concentrations.Compared with NTEG rats, beside reduced exercise tolerance (60±5 vs. 15±3 minutes (p = 0.002 the 8-OhdG liver tissue concentrations were significantly higher (p = 0.040 in the HTEG rats. The HTEG developed more organ tissue damage and cellular fragmentations of liver cells. In both exercise groups TNF-α and IL-6 serum concentrations were enhanced significantly (p<0.001 being highest in the HTEG animals. Serum ALT, AST, LDH, CREA, BUN and CK concentrations were significantly enhance in both exercise groups.In our exertional heat stroke rat model, we found tissue damage particularly in livers during exercises in hot and humid environment that was related to inflammation, oxidative stress and apoptosis.

  18. [Diversity of crenarchaeota in terrestrial hot springs and their surrounding environments in Kamchatka, Russia].

    Science.gov (United States)

    Song, Zhaoqi; Wang, Li; Chen, Jinquan; Zhou, Enmin; Zhang, Chuanlun; Li, Wenjun

    2013-06-04

    Crenarchaeota is a major archaeal lineage in terrestrial hot springs and important in biogeochemical cycles of life-essential elements. In this study, we investigated the diversity of Crenarchaeota in hot springs and the surrounding environments in Kamchatka, Russia. In addition, we compared crenarchaeotal community structures in Kamchatka, Russia and Yunnan province, China. Crenarchaeal 16S rRNA gene clone libraries were constructed and the sequences and abundances of representational clone were obtained. Phylogenetic analysis was then performed and the community structures in different samples were compared. The high temperature spring Burlyashi Liza (BSL, 89 degrees C) comprised Thermoprotei. The moderate temperature spring TF Vent 2 (TFV, 49 degrees C) harbored unidentified Thermoprotei group, unidentified crenarchaeal group, HWCG-II (hot water crenarchaeotal group II), and Group1. 1b (one thaumarchaeotal subgroup). Most of sequences that obtained from surrounding environments ( Crenarchaeota in Kamchatka hot springs are somewhat different from those in Yunnan province. Terrestrial hot springs obviously affect the crenarchaeotal communities in surrounding environments. Temperature is the major factor controlling the community structure in terrestrial hot springs.

  19. Microbiology and geochemistry of Little Hot Creek, a hot spring environment in the Long Valley Caldera.

    Science.gov (United States)

    Vick, T J; Dodsworth, J A; Costa, K C; Shock, E L; Hedlund, B P

    2010-03-01

    A culture-independent community census was combined with chemical and thermodynamic analyses of three springs located within the Long Valley Caldera, Little Hot Creek (LHC) 1, 3, and 4. All three springs were approximately 80 degrees C, circumneutral, apparently anaerobic and had similar water chemistries. 16S rRNA gene libraries constructed from DNA isolated from spring sediment revealed moderately diverse but highly novel microbial communities. Over half of the phylotypes could not be grouped into known taxonomic classes. Bacterial libraries from LHC1 and LHC3 were predominantly species within the phyla Aquificae and Thermodesulfobacteria, while those from LHC4 were dominated by candidate phyla, including OP1 and OP9. Archaeal libraries from LHC3 contained large numbers of Archaeoglobales and Desulfurococcales, while LHC1 and LHC4 were dominated by Crenarchaeota unaffiliated with known orders. The heterogeneity in microbial populations could not easily be attributed to measurable differences in water chemistry, but may be determined by availability of trace amounts of oxygen to the spring sediments. Thermodynamic modeling predicted the most favorable reactions to be sulfur and nitrate respirations, yielding 40-70 kJ mol(-1) e(-) transferred; however, levels of oxygen at or below our detection limit could result in aerobic respirations yielding up to 100 kJ mol(-1) e(-) transferred. Important electron donors are predicted to be H(2), H(2)S, S(0), Fe(2+) and CH(4), all of which yield similar energies when coupled to a given electron acceptor. The results indicate that springs associated with the Long Valley Caldera contain microbial populations that show some similarities both to springs in Yellowstone and springs in the Great Basin.

  20. Microbial (per)chlorate reduction in hot subsurface environments

    NARCIS (Netherlands)

    Liebensteiner, M.

    2014-01-01

     

    The microbial reduction of chlorate and perchlorate has been known for long as a respiratory process of mesophilic bacteria that thrive in diverse environments such as soils, marine and freshwater sediments. Chlorate and perchlorate are found in nature deriving from anthropogenic and

  1. Pre-Pubertal Children and Exercise in Hot and Humid Environments: A Brief Review

    OpenAIRE

    Sinclair, Wade H.; Crowe, Melissa J.; Spinks, Warwick L.; Leicht, Anthony S.

    2007-01-01

    The ability of pre-pubertal children to regulate their body temperature under thermoneutral environments is similar to that of an adult albeit via differing routes. However, this ability is challenged when exposed to extreme environments. Thermoregulatory responses of pre-pubertal children differ from adults via adaptations that occur during growth and maturation and disadvantage children when exercising in hot and humid environments. When ambient temperatures exceed that of the skin, an infl...

  2. A CNC milling machine in NRG's Hot Cell Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Tjoa, G.L.; Thoor, C.M.E.; Boekhout, P.f. Van

    2001-07-01

    Preparations are in progress to install a new milling machine in the NRG's hot cells facility in the course of this year. The milling machine is CNC controlled and adapted for use in a hot cell environment. Special arrangements are made to comply for this purpose. Since a number of components are not fully resistant to radiation, the machine is wheeled allowing it to be removed from the hot cell if not needed. Some technical specifications from the various manufacturers will be discussed which finally lead to the selected supplier. Primary, this only concerns the flexibility of the total equipment to adapt for remote control and not the general technical aspects of the equipment. The machine will be used mainly to manufacture mechanical testing samples form irradiated materials, obtained from both welding experiments and other irradiated components. Special auxiliary tools are made for this purpose to facilitate the machining of the samples. Next the convenience to program the system for machining mechanical testing samples to meet the specified requirements is also important. Before installing the equipment in the hot cell a try out is performed to evaluate the system. (Author)

  3. Safety analysis report for Hot-Cell irradiated specimen cask

    Energy Technology Data Exchange (ETDEWEB)

    Ku, J. H.; Lee, J. C.; Seo, K. S.; Lee, D. W. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-03-01

    For the examination of spent fuels and radioactive materials by using scanning electron microscope, a irradiated specimen cask is needed to transport the specimen from the hot-cell to the shielded glove box in which the scanning electron microscope is installed. This cask should be easy to handle and transport, has safe to maintain the shielding safety of operators as well as the thermal and structural integrities under prescribed load conditions by the regulations as requirements. Also the cask should be assured that docked perfectly maintaining shielding integrity with the interfaces of hot-cell and shield glove box. Accordingly, the main features of cask were analyzed with functional capabilities, and the integrities of cask under required load conditions were evaluated. Therefore, it was verified that the cask is suitable to use at the outside transport as well as Post Irradiated Examination Facility in KAERI. 9 refs., 50 figs., 14 tabs. (Author)

  4. Heat exchange during encapsulation in a Chemical-Warfare Agent Protective Patient Wrap in four hot environments. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, L.A.; Kolka, M.A.; Allan, A.E.; Santee, W.R.

    1987-04-01

    The purpose of this study was to determine safe encapsulation time limits in four hot environments including a simulated solar heat load and thereby generate an equation predicting safe time limits for hot environments. Eight male subjects were studied during encapsulation in a Chemical Warfare Agent Protective Patient Wrap in each of four environments. Rectal temperature, mean skin temperature, mean body temperature air temperature and dew point temperature within the wrap and wrap temperature were measured every minute. Metabolic rate was measured during encapsulation by partitional calorimetry. The data shows that safe encapsulation time is severely limited in Hot/Dry and Hot/Wet environments when a solar heat load is included.

  5. Predicted Thermal Sensation Index for the Hot Environment in the Spinning Workshop

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    Rui-Liang Yang

    2015-01-01

    Full Text Available The spinning workshop is the most typical cotton textile workshop in the textile mill and is characterized by the feature of high temperature all the year. To effectively evaluate the general thermal sensation of the textile worker exposed to the hot environment in the spinning workshop, a new heat index named predicted thermal sensation (PTS index was proposed in this paper. The PTS index based on the heat balance equation can be derived by the empirical equations of air temperature and heat imbalance. A one-month-long continuous research was carried out to investigate the actual thermal condition and judge the validity of the PTS index. Actual workshop temperatures in the spinning workshop during the measuring period were all above 32°C, belonging to extreme hot environment. The calculated thermal sensation by the PTS index is very close to the actual thermal sensation, which means that the PTS index can accurately estimate the actual thermal sensation of the textile workers exposed to the hot environment in the spinning workshop. Compared to other indices, the PTS index can more effectively predict the mean thermal response of a large group of textile workers exposed to the hot environment in the spinning workshop.

  6. Animal Breeding Considerations for Improved Animal Performance in Hot Environments

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    J. W. Fuquay

    1996-01-01

    Full Text Available A variety of options are available for improved performance including altering genotype with genetic improvement of indigenous breeds through selective breeding; upgrading through crossbreeding of indigenous females with semen from genetically superior exotic males with a possible goal of developing a new breed; and introduction of new breeds through transfer of embryos from genetically superior exotic breeds into indigenous females or importation of exotic animals of the desired breeding. Each option has its advantages and disadvantages. The most rapid gains mightbe possible new environment can be a problem.  In the interest of adaptation and survival, systems that utilize the maternal influences of indigenous females are advantageous. In consideration of this maternal influences along with rate of improvement and potential for extensive improvement, both crossbreeding programs that use semen from genetically superior exotic males and those that involve transfer of genetically superior embryo survival and neonatal survival will affect management of any option chosen for genetic improvement but should be of less concern in programs that utilize indigenous females.

  7. The impact of silicon solar cell architecture and cell interconnection on energy yield in hot & sunny climates

    KAUST Repository

    Haschke, Jan

    2017-03-23

    Extensive knowledge of the dependence of solar cell and module performance on temperature and irradiance is essential for their optimal application in the field. Here we study such dependencies in the most common high-efficiency silicon solar cell architectures, including so-called Aluminum back-surface-field (BSF), passivated emitter and rear cell (PERC), passivated emitter rear totally diffused (PERT), and silicon heterojunction (SHJ) solar cells. We compare measured temperature coefficients (TC) of the different electrical parameters with values collected from commercial module data sheets. While similar TC values of the open-circuit voltage and the short circuit current density are obtained for cells and modules of a given technology, we systematically find that the TC under maximum power-point (MPP) conditions is lower in the modules. We attribute this discrepancy to additional series resistance in the modules from solar cell interconnections. This detrimental effect can be reduced by using a cell design that exhibits a high characteristic load resistance (defined by its voltage-over-current ratio at MPP), such as the SHJ architecture. We calculate the energy yield for moderate and hot climate conditions for each cell architecture, taking into account ohmic cell-to-module losses caused by cell interconnections. Our calculations allow us to conclude that maximizing energy production in hot and sunny environments requires not only a high open-circuit voltage, but also a minimal series-to-load-resistance ratio.

  8. Standard guide for general design considerations for hot cell equipment

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 Intent: 1.1.1 The intent of this guide is to provide general design and operating considerations for the safe and dependable operation of remotely operated hot cell equipment. Hot cell equipment is hardware used to handle, process, or analyze nuclear or radioactive material in a shielded room. The equipment is placed behind radiation shield walls and cannot be directly accessed by the operators or by maintenance personnel because of the radiation exposure hazards. Therefore, the equipment is operated remotely, either with or without the aid of viewing. 1.1.2 This guide may apply to equipment in other radioactive remotely operated facilities such as suited entry repair areas, canyons or caves, but does not apply to equipment used in commercial power reactors. 1.1.3 This guide does not apply to equipment used in gloveboxes. 1.2 Applicability: 1.2.1 This guide is intended for persons who are tasked with the planning, design, procurement, fabrication, installation, or testing of equipment used in rem...

  9. Effect of hot-dry environment on fiber-reinforced self-compacting concrete

    Science.gov (United States)

    Tioua, Tahar; Kriker, Abdelouahed; Salhi, Aimad; Barluenga, Gonzalo

    2016-07-01

    Drying shrinkage can be a major reason for the deterioration of concrete structures. Variation in ambient temperature and relative humidity cause changes in the properties of hardened concrete which can affect their mechanical and drying shrinkage characteristics. The present study investigated mechanical strength and particularly drying shrinkage properties of self-compacting concretes (SCC) reinforced with date palm fiber exposed to hot and dry environment. In this study a total of nine different fibers reinforced self compacting concrete (FRSCC) mixtures and one mixture without fiber were prepared. The volume fraction and the length of fibers reinforcement were 0.1-0.2-0.3% and 10-20-30 mm. It was observed that drying shrinkage lessened with adding low volumetric fraction and short length of fibers in curing condition (T = 20 °C and RH = 50 ± 5 %), but increased in hot and dry environment.

  10. Evaluation of Three Hydration Strategies in Detection Dogs Working in a Hot Environment

    Directory of Open Access Journals (Sweden)

    Cynthia M. Otto

    2017-10-01

    Full Text Available Physical activity in hot environments can increase the risk of heat stress or heat stroke in dogs. Heat tolerance is influenced by acclimatization to the environment, physical fitness, and hydration state. Three common strategies to promote hydration in working dogs are free access to water (W, oral electrolyte solutions (OESs, and administration of subcutaneous fluids (SQs. None of these methods have been compared for safety or efficacy in a working environment. In a cross-over design, seven vehicle-screening canines were randomly assigned to each of the three hydration strategies during working shifts at the Sarita, TX checkpoint. Physical, behavioral, and biochemical parameters were collected before, during, and after a work shift (mean 5.7 ± 0.8 h. Dogs were given 10 mL/kg oral W, 10 mL/kg chicken flavored OES, or 15 mL/kg of SQs initially followed by controlled access to W or OES. The dogs drank 15.61 ± 4.47 mL/kg/h of W and OES when in the OES group, compared to 7.04 ± 3.42 and 5.56 ± 4.40 mL of W, for the W and SQ groups, respectively. The median environmental temperature was 84.8°F (29.3°C. The median humidity was 70%. Based on mixed effects linear modeling, dogs in the OES and SQ groups had significantly higher total CO2, and lower packed cell volume and total plasma protein at the end of the day. Creatinine increased a small but significant amount in the SQ group and decreased in the OES group. Searching behaviors were independent of hydration strategy but highly related to the dog specific factors of sex, breed, and activity level. Under conditions of controlled activity in moderate heat and humidity, dogs accustomed to the work and the environment were more likely to increase fluid consumption and hydration when provided a flavored OES. Potential benefits of OES and SQ were indirect and no adverse effects were documented for any of the hydration strategies tested.

  11. PRE-PUBERTAL CHILDREN AND EXERCISE IN HOT AND HUMID ENVIRONMENTS: A BRIEF REVIEW

    Directory of Open Access Journals (Sweden)

    Wade H. Sinclair

    2007-12-01

    Full Text Available The ability of pre-pubertal children to regulate their body temperature under thermoneutral environments is similar to that of an adult albeit via differing routes. However, this ability is challenged when exposed to extreme environments. Thermoregulatory responses of pre-pubertal children differ from adults via adaptations that occur during growth and maturation and disadvantage children when exercising in hot and humid environments. When ambient temperatures exceed that of the skin, an influx of thermal energy from the environment increases thermal stress. When coupled with exercise, the increased thermal stress results in reduced physical performance and an increased risk of developing heat-related illness. Evidence suggesting the severity of heat-related illness is greater in pre-pubertal children than adults is inconclusive because age-related differences in thermoregulatory responses are attributed to either morphologic or functional changes. Additionally, the majority of research on pre-pubertal children exercising in the heat has been maturational or comparative studies with adults conducted in the near absence of convective cooling, complicating extrapolation to field-based environments. However, current consensus is that pre-pubertal children are disadvantaged when exercising in extreme temperatures and that care should be taken in preparing for and conducting sporting activities in hot and humid environments for pre-pubertal children

  12. Responses of distance runners and sprinters to exercise in a hot environment.

    Science.gov (United States)

    Irion, G L

    1987-10-01

    The responses of highly trained distance runners and track sprinters and age-matched untrained men were compared during bicycle ergometry in a 40 degree temperature-controlled environmental chamber. There were no differences among groups in rectal temperature following the 90 min exercise bout. Distance runners had a lower heart rate than either sprinters or untrained subjects. There was no difference in heart rate between sprinters and untrained subjects. Distance runners and sprinters had a much greater sweat rate than untrained subjects and dissipated a greater proportion of their total heat load by evaporation of sweat. Sprinters, however, had a lower sweat rate than distance runners in the hot environment and could only maintain as low a skin temperature as distance runners for 75 min of the 90 min session. Both aerobic training and anaerobic training confer some degree of protection from heat injury during exercise in a hot environment. However, sprinters have a higher heart rate and cannot sustain a low skin temperature as long as distance runners. Sprinters lost their advantage over untrained subjects in skin temperature after 75 min of exercise in a hot environment and did not have a lower heart rate than untrained subjects. Distance runners had a significantly lower heart rate and maintained a lower skin temperature than untrained subjects for the entire 90 min exercise bout.

  13. Environmental Assessment for decontaminating and decommissioning the General Atomics Hot Cell Facility. Final [report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This EA evaluates the proposed action to decontaminate and decommission GA`s hot cell facility in northern San Diego, CA. This facility has been used for DOE and commercial nuclear R&D for > 30 years. About 30,000 cubic feet of decontamination debris and up to 50,000 cubic feet of contaminated soil are to be removed. Low-level radioactive waste would be shipped for disposal. It was determined that the proposal does not constitute a major federal action significantly affecting the human environment according to NEPA; therefore, a finding of no significant impact is made, and an environmental impact statement is not required.

  14. Nonthermal sensory input and altered human thermoregulation: effects of visual information depicting hot or cold environments

    Science.gov (United States)

    Takakura, Jun'ya; Nishimura, Takayuki; Choi, Damee; Egashira, Yuka; Watanuki, Shigeki

    2015-10-01

    A recent study showed that thermoregulatory-like cardiovascular responses can be invoked simply by exposure to visual information, even though the thermal environments are neutral and unchanged. However, it was not clear how such responses affect actual human body temperature regulation. We investigated whether such visually invoked physiological responses can substantively affect human core body temperature in a thermally challenging cold environment. Participants comprised 13 graduate or undergraduate students viewing different video images containing hot, cold, or no scenery, while room temperature was gradually lowered from 28 to 16 °C over 80 min. Rectal temperature, mean skin temperature, core to skin temperature gradient, and oxygen consumption were measured during the experiment. Rectal temperature was significantly lower when hot video images were presented compared to when control video images were presented. Oxygen consumption was comparable among all video images, but core to skin temperature gradient was significantly lower when hot video images were presented. This result suggests that visual information, even in the absence of thermal energy, can affect human thermodynamics and core body temperature.

  15. Impact of Hot Environment on Fluid and Electrolyte Imbalance, Renal Damage, Hemolysis, and Immune Activation Postmarathon

    Directory of Open Access Journals (Sweden)

    Rodrigo Assunção Oliveira

    2017-01-01

    Full Text Available Previous studies have demonstrated the physiological changes induced by exercise exposure in hot environments. We investigated the hematological and oxidative changes and tissue damage induced by marathon race in different thermal conditions. Twenty-six male runners completed the São Paulo International Marathon both in hot environment (HE and in temperate environment (TE. Blood and urine samples were collected 1 day before, immediately after, 1 day after, and 3 days after the marathon to analyze the hematological parameters, electrolytes, markers of tissue damage, and oxidative status. In both environments, the marathon race promotes fluid and electrolyte imbalance, hemolysis, oxidative stress, immune activation, and tissue damage. The marathon runner’s performance was approximately 13.5% lower in HE compared to TE; however, in HE, our results demonstrated more pronounced fluid and electrolyte imbalance, renal damage, hemolysis, and immune activation. Moreover, oxidative stress induced by marathon in HE is presumed to be related to protein/purine oxidation instead of other oxidative sources. Fluid and electrolyte imbalance and protein/purine oxidation may be important factors responsible for hemolysis, renal damage, immune activation, and impaired performance after long-term exercise in HE. Nonetheless, we suggested that the impairment on performance in HE was not associated to the muscle damage and lipoperoxidation.

  16. Hot wire deposited hydrogenated amorphous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

  17. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Subcontracting for nuclear....225-70 Subcontracting for nuclear hot cell services. As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993) (a...

  18. Biological shielding test of hot cells with high active source 60Co (300 TBq)

    Science.gov (United States)

    Švrčula, P.; Zoul, D.; Zimina, M.; Petříčková, A.; Adamíková, T.; Schulc, M.; Srba, O.

    2017-11-01

    This article describes a method for testing of the efficiency of the biological shielding of the hot cell facility, which were constructed as a part of the project SUSEN. Ten hot cells and one semi-hot cell are present in the facility Radiochemistry II. The shielding is made from steel plates. In order to demonstrate sufficient efficiency of the biological shielding of the hot cells and a correspondence between measured and contractual values at selected points. The test was done using sealed high activity 60Co sources. The results are also used as a proof of the optimization of radiation protection for the workplace of this type. The results confirm significant optimization of radiation protection at the workplace. The dose received by a staff do not exceed one tens of annual limit during active service. Obtained results fulfill general requirements of radiation protection and will be used for further active service of hot cells facility.

  19. Exercise in a hot environment influences plasma anti-inflammatory and antioxidant status in well-trained athletes.

    Science.gov (United States)

    Sureda, Antoni; Mestre-Alfaro, Antonia; Banquells, Montserrat; Riera, Joan; Drobnic, Franchek; Camps, Jordi; Joven, Jorge; Tur, Josep A; Pons, Antoni

    2015-01-01

    Exercise in thermally stressful environmental conditions can enhance oxidative stress. We sought to measure the plasma antioxidant defenses and cytokine response together with oxidative damage post-exercise in a temperate versus a hot environment. The plasma concentrations of vasoactive endothelin-1 and vascular angiogenic growth factor were also evaluated. Male athletes (n=9) volunteered to participate. The athletes randomly performed two bouts of treadmill exercise of 45min at 75-80% of maximal oxygen uptake in a climatic-controlled chamber under two different conditions: temperate environment (10-12°C, 40-55% humidity) and hot, humid environment (30-32°C, 75-78% humidity). Venous blood samples were obtained immediately pre- and post-bout and on recovery after 2h. Serum glucose, malondialdehyde and lactate concentrations were significantly increased post-exercise in hot but maintained in the temperate environment; these post-exercise values were significantly higher after exercise in hot than in temperate. Urinary 8-hydroxy-2'-deoxyguanosine concentration, plasma phosphocreatine kinase and catalase activities, creatinine and monocyte chemoattractant protein-1, and interleukin-6 significantly increased post-exercise in hot but maintained in temperate environment. The post-exercise circulating values of antioxidant enzyme paraoxonase-1 and endothelin were significantly higher in the hot than in temperate environment. Exercise in a hot and humid environment resulted in mild hyperthermia with elevated perceived exertion and thermal stress. Hyperthermic environment induced hyperglycemia, lactatecidemia and more cellular and oxidative damage than exercise in a temperate environment but also induced a post-exercise antioxidant and anti-inflammatory response in plasma. These results suggest that environmental temperature needs to be taken into account when evaluating exercise-related oxidative stress and inflammation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. CESE: Cell Electrophysiology Simulation Environment.

    Science.gov (United States)

    Missan, Sergey; McDonald, Terence F

    2005-01-01

    Cell electrophysiology simulation environment (CESE) is an integrated environment for performing simulations with a variety of electrophysiological models that have Hodgkin-Huxley and Markovian formulations of ionic currents. CESE is written in Java 2 and is readily portable to a number of operating systems. CESE allows execution of single-cell models and modification and clamping of model parameters, as well as data visualisation and analysis using a consistent interface. Model creation for CESE is facilitated by an object-oriented approach and use of an extensive modelling framework. The Web-based model repository is available. CESE and the Web-based model repository are available at http://cese.sourceforge.net/.

  1. Working in a hot environment; perspiration loss; a drink for persons working under hot conditions, part 2

    Science.gov (United States)

    Glatzel, H.

    1978-01-01

    Losses of various nutrients through sweat of persons working under hot conditions were considered. On the basis of these considerations a supplemental drink was formulated consisting of 1 liter of water per hour containing salt, potassium chloride, iron, thiamine and ascorbic acid.

  2. Physiological reactions of men using microclimate cooling in hot humid environments

    Science.gov (United States)

    Rensburg, A. J. Van; Mitchell, D.; Walt, W. H. Van Der; Strydom, N. B.

    1972-01-01

    van Rensburg, A. J., Mitchell, D., van der Walt, W. H., and Strydom, N. B. (1972).Brit. J. industr. Med.,29, 387-393. Physiological reactions of men using microclimate cooling in hot humid environments. This paper describes the laboratory testing of a water-cooled vest and of a pre-frozen jacket on men working in hot humid environments. The work rate used in the tests was comparable with that of moderately hard industrial work. Three measures of strain were used, namely, rectal temperature, heart rate, and sweat rate. The tests showed that the water-cooled vest provided protection physiologically equivalent to removing the entire environmental heat stress, even at wet bulb temperatures of 33·9°C. The pre-frozen jackets provided better protection at 32·2°C wet bulb than at 33·9°C wet bulb. The garments have the potential to restore the loss in productivity caused by heat stress. Images PMID:4636660

  3. Comparison of techniques for the measurement of skin temperature during exercise in a hot, humid environment

    Directory of Open Access Journals (Sweden)

    Brian K McFarlin

    2014-10-01

    Full Text Available Exercising or working in a hot, humid environment can results in the onset of heat-related illness when an individual’s temperature is not carefully monitored. The purpose of the present study was to compare three techniques (data loggers, thermal imaging, and wired electrodes for the measurement of peripheral (bicep and central (abdominal skin temperature. Young men and women (N=30 were recruited to complete the present study. The three skin temperature measurements were made at 0 and every 10-min during 40-min (60% VO 2 max of cycling in a hot (39±2°C, humid (45±5% RH environment. Data was statistically analyzed using the Bland-Altman method and correlation analysis. For abdominal skin temperature, the Bland-Altman limits of agreement indicated that data loggers (1.5 were a better index of wired than was thermal imaging (3.5, For the bicep skin temperature the limits of agreement was similar between data loggers (1.9 and thermal (1.9, suggesting the both were suitable measurements. We also found that when skin temperature exceeded 35ºC, we observed progressively better prediction between data loggers, thermal imaging, and wired skin sensors. This report describes the potential for the use of data loggers and thermal imaging to be used as alternative measures of skin temperature in exercising, human subjects

  4. Mouth rinsing improves cycling endurance performance during Ramadan fasting in a hot humid environment.

    Science.gov (United States)

    Che Muhamed, Ahmad Munir; Mohamed, Nazirah Gulam; Ismail, Norjana; Aziz, Abdul Rashid; Singh, Rabindarjeet

    2014-04-01

    This study examined the effect of mouth rinsing during endurance cycling in a hot humid environment (32 °C and 75% relative humidity) on athletes in the Ramadan fasted state. Nine trained adolescent male cyclists completed 3 trials that consisted of a carbohydrate mouth-rinse (CMR), a placebo mouth-rinse (PMR), and a no-rinse (NOR) trial during the last 2 weeks of Ramadan. Each trial consisted of a preloading cycle at 65% peak rate of oxygen consumption for 30 min followed by a 10-km time trial (TT10 km) under hot humid condition. During the CMR and PMR trials, each cyclist rinsed his mouth with 25 mL of the solution for 5 s before expectorating the solution pre-exercise, after 5, 15, and 25 min of the preloading cycle, and 15 s prior to the start of TT10 km. Time to complete the TT10 km was significantly faster in the CMR and PMR trials compared with the NOR trial (12.9 ± 1.7 and 12.6 ± 1.7 vs. 16.8 ± 1.6 min, respectively; p benefits compared with a no-rinse condition on TT10 km performance in acute Ramadan fasted subjects during endurance cycling in a heat stress environment.

  5. Effect of physical training in cool and hot environments on +Gz acceleration tolerance in women

    Science.gov (United States)

    Brock, P. J.; Sciaraffa, D.; Greenleaf, J. E.

    1982-01-01

    Acceleration tolerance, plasma volume, and maximal oxygen uptake were measured in 15 healthy women before and after submaximal isotonic exercise training periods in cool and hot environments. The women were divided on the basis of age, maximal oxygen uptake, and +Gz tolerance into three groups: a group that exercised in heat (40.6 C), a group that exercised at a lower temperature (18.7 C), and a sedentary control group that functioned in the cool environment. There was no significant change in the +Gz tolerance in any group after training, and terminal heart rates were similar within each group. It is concluded that induction of moderate acclimation responses without increases in sweat rate or resting plasma volume has no influence on +Gz acceleration tolerance in women.

  6. Multiple genomic signatures of selection in goats and sheep indigenous to a hot arid environment

    Science.gov (United States)

    Kim, E-S; Elbeltagy, A R; Aboul-Naga, A M; Rischkowsky, B; Sayre, B; Mwacharo, J M; Rothschild, M F

    2016-01-01

    Goats and sheep are versatile domesticates that have been integrated into diverse environments and production systems. Natural and artificial selection have shaped the variation in the two species, but natural selection has played the major role among indigenous flocks. To investigate signals of natural selection, we analyzed genotype data generated using the caprine and ovine 50K SNP BeadChips from Barki goats and sheep that are indigenous to a hot arid environment in Egypt's Coastal Zone of the Western Desert. We identify several candidate regions under selection that spanned 119 genes. A majority of the genes were involved in multiple signaling and signal transduction pathways in a wide variety of cellular and biochemical processes. In particular, selection signatures spanning several genes that directly or indirectly influenced traits for adaptation to hot arid environments, such as thermo-tolerance (melanogenesis) (FGF2, GNAI3, PLCB1), body size and development (BMP2, BMP4, GJA3, GJB2), energy and digestive metabolism (MYH, TRHDE, ALDH1A3), and nervous and autoimmune response (GRIA1, IL2, IL7, IL21, IL1R1) were identified. We also identified eight common candidate genes under selection in the two species and a shared selection signature that spanned a conserved syntenic segment to bovine chromosome 12 on caprine and ovine chromosomes 12 and 10, respectively, providing, most likely, the evidence for selection in a common environment in two different but closely related species. Our study highlights the importance of indigenous livestock as model organisms for investigating selection sweeps and genome-wide association mapping. PMID:26555032

  7. Characterization report for Building 301 Hot Cell Facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    During the period from October, 1997, through March, 1998, ANL-E Health Physics conducted a pre-D and D characterization of Building 301, referred to as the Hot Cell Facility. While primary emphasis was placed on radiological evaluation, the presence of non-nuclear hazardous and toxic material was also included in the scope of the characterization. This is one of the early buildings on the ANL-E site, and was heavily used in the 1950`s and 1960`s for various nuclear reaction and reactor design studies. Some degree of cleanup and contamination fixation was done in the 1970`s, so that the building could be used with a minimum of risk of personnel contamination. Work records are largely nonexistent for the early history of the building, so that any assumptions about extent and type of contamination had to be kept very open in the survey planning process. The primary contaminant was found to be painted-over Cs-137 embedded in the concrete floors, although a variety of other nuclides consistent with the work said to have been performed were found in smaller quantities. Due to leaks and drips through the floor, a relatively modest amount of soil contamination was found in the service trench under the building, not penetrating deeply. Two contaminated, disconnected drain lines leaving the building could not be traced by site records, and remain a problem for remediation. The D and D Characterization Plan was fulfilled.

  8. Risk factors for heat illness among British soldiers in the hot Collective Training Environment.

    Science.gov (United States)

    Moore, Alice C; Stacey, M J; Bailey, K G H; Bunn, R J; Woods, D R; Haworth, K J; Brett, S J; Folkes, S E F

    2016-12-01

    Heat illness is a preventable disorder in military populations. Measures that protect vulnerable individuals and contribute to effective Immediate Treatment may reduce the impact of heat illness, but depend upon adequate understanding and awareness among Commanders and their troops. To assess risk factors for heat illness in British soldiers deployed to the hot Collective Training Environment (CTE) and to explore awareness of Immediate Treatment responses. An anonymous questionnaire was distributed to British soldiers deployed in the hot CTEs of Kenya and Canada. Responses were analysed to determine the prevalence of individual (Intrinsic) and Command-practice (Extrinsic) risk factors for heat illness and the self-reported awareness of key Immediate Treatment priorities (recognition, first aid and casualty evacuation). The prevalence of Intrinsic risk factors was relatively low in comparison with Extrinsic risk factors. The majority of respondents were aware of key Immediate Treatment responses. The most frequently reported factors in each domain were increased risk by body composition scoring, inadequate time for heat acclimatisation and insufficient briefing about casualty evacuation. Novel data on the distribution and scale of risk factors for heat illness are presented. A collective approach to risk reduction by the accumulation of 'marginal gains' is proposed for the UK military. This should focus on limiting Intrinsic risk factors before deployment, reducing Extrinsic factors during training and promoting timely Immediate Treatment responses within the hot CTE. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage

    Science.gov (United States)

    Limpert, Steven; Burke, Adam; Chen, I.-Ju; Anttu, Nicklas; Lehmann, Sebastian; Fahlvik, Sofia; Bremner, Stephen; Conibeer, Gavin; Thelander, Claes; Pistol, Mats-Erik; Linke, Heiner

    2017-10-01

    Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated ‘hot carriers’ before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

  10. Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage.

    Science.gov (United States)

    Limpert, Steven; Burke, Adam; Chen, I-Ju; Anttu, Nicklas; Lehmann, Sebastian; Fahlvik, Sofia; Bremner, Stephen; Conibeer, Gavin; Thelander, Claes; Pistol, Mats-Erik; Linke, Heiner

    2017-10-27

    Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated 'hot carriers' before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

  11. Standard practice for determining cracking susceptibility of metals exposed under stress to a hot salt environment

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1990-01-01

    1.1 This practice covers procedures for testing metals for embrittlement and cracking susceptibility when exposed under stress to a hot salt environment. This practice can be used for testing all metals for which service conditions dictate the need for such information. The test procedures described herein are generally applicable to all metal alloys; required adjustments in environmental variables (temperature, stress) to characterize a given materials system should be made. This practice describes the environmental conditions and degree of control required, and suggests means for obtaining this desired control. 1.2 This practice can be used both for alloy screening for determination of relative susceptibility to embrittlement and cracking, and for the determination of time-temperature-stress threshold levels for onset of embrittlement and cracking. However, certain specimen types are more suitable for each of these two types of characterizations. Note 1 This practice relates solely to the performance of ...

  12. Effects of solar radiation on endurance exercise capacity in a hot environment.

    Science.gov (United States)

    Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip; Maughan, Ronald J

    2016-04-01

    The present study investigated the effects of variations in solar radiation on endurance exercise capacity and thermoregulatory responses in a hot environment. Eight male volunteers performed four cycle exercise trials at 70 % maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50 % relative humidity. Volunteers were tested under four solar radiation conditions: 800, 500, 250 and 0 W/m(2). Exercise time to exhaustion was less on the 800 W/m(2) trial (23 ± 4 min) than on all the other trials (500 W/m(2) 30 ± 7 min; P 0.05). Mean skin temperature was higher on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P solar radiation increases.

  13. Oral administration of γ-aminobutyric acid affects heat production in a hot environment in resting humans

    Directory of Open Access Journals (Sweden)

    Miyazawa Taiki

    2012-02-01

    Full Text Available Abstract Background Central administration of γ-amino butyric acid (GABA induces lower body temperature in animals in hot ambient air. However, it is still unknown whether oral GABA administration affects temperature regulation at rest in a hot environment in humans. Therefore, in the present study, we specifically hypothesized that systemic administration of GABA in humans would induce hypothermia in a hot environment and that this response would be observed in association with decreased heat production. Methods Eight male participants drank a 200-ml sports drink with 1 g of GABA (trial G or without GABA (trial C, then rested for 30 minutes in a sitting position in a hot environment (ambient air temperature 33°C, relative humidity 50%. Results We found that changes in esophageal temperature from before drinking the sports drink were lower in trial G than in trial C (-0.046 ± 0.079°C vs 0.001 ± 0.063°C; P 2 vs 47 ± 8 W/m2; P Conclusions In this study, we have demonstrated that a single oral administration of GABA induced a larger decrease in body core temperature compared to a control condition during rest in a hot environment and that this response was concomitant with a decrease in total heat production.

  14. Heat strain evaluation of overt and covert body armour in a hot and humid environment.

    Science.gov (United States)

    Pyke, Andrew J; Costello, Joseph T; Stewart, Ian B

    2015-03-01

    The aim of this study was to elucidate the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. Eight healthy males walked on a treadmill for 120 min at 22% of their heart rate reserve in a climate chamber simulating 31 °C (60%RH) wearing either no armour (control), overt or covert PBA in addition to a security guard uniform, in a randomised controlled crossover design. No significant difference between conditions at the end of each trial was observed in core temperature, heart rate or skin temperature (P > 0.05). Covert PBA produced a significantly greater amount of body mass change (-1.81 ± 0.44%) compared to control (-1.07 ± 0.38%, P = 0.009) and overt conditions (-1.27 ± 0.44%, P = 0.025). Although a greater change in body mass was observed after the covert PBA trial; based on the physiological outcome measures recorded, the heat strain encountered while wearing lightweight, non-military overt or covert PBA was negligible compared to no PBA. The wearing of bullet proof vests or body armour is a requirement of personnel engaged in a wide range of occupations including police, security, customs and even journalists in theatres of war. This randomised controlled crossover study is the first to examine the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. We conclude that the heat strain encountered while wearing both overt and covert lightweight, non-military PBA was negligible compared to no PBA. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  15. Heat exchange during encapsulation in a chemical warfare agent protective patient wrap in four hot environments

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, L.A.; Kolka, M.A.; Allan, A.E.; Santee, W.R.

    1988-04-01

    Tolerable encapsulation time in a Chemical Warfare Agent Protective Patient Wrap (dry insulative value = 1.44 clo; permeability index = 0.25) was determined in four hot environments including a simulated solar heat load (1152 W.m-2) for eight males. Mean body temperature (Tb), evaporative heat loss (EHL), dry heat gain (R + C), metabolic rate (M), and net heat flow (Msk) were measured or calculated from the heat balance equation. The ambient temperature (Ta) ranged from 54.7 degrees C (I) to 35.7 degrees C (IV) and the relative humidity ranged from 17% (I) to 63% (IV). EHL ranged from 173.5 W.m-2 (IV) to 277.8 W.m-2 (I) at min 30 of encapsulation. R + C ranged from -129 W.m-2 (IV) to -230 W.m-2 (I) at that time and Tb averaged 37.6(+/- 0.3) degrees C (IV) and 38.1(+/- 0.2) degrees C (I). The average time of encapsulation ranged from 61.8(+/- 0.2) degrees C (I). The average time of encapsulation ranged from 61.8(+/- 13.2) min (IV) to 38.4(+/- 5.0) min (I). A multiple linear regression equation to predict tolerable encapsulation was developed. These data show that tolerable encapsulation is severely limited in hot environments which have a marked solar heat load. A preliminary study (n = 2) indicated that encapsulation time in 54.7 degrees C/17%rh could be extended by some 23 min by covering the WRAP with wetted towels, thereby decreasing body heat storage by enhancing EHL from the surface of the WRAP.

  16. Toward Understanding Prevalence of Airborne Microorganisms in a Hot-Arid Environment

    Directory of Open Access Journals (Sweden)

    Abdel Hameed A.A.

    2017-01-01

    Full Text Available This study aims to determine prevalence of microorganisms in the air state and those associated particulate matter (PM in a hot arid environment (Makkah city, Saudi Arabia in relation to time of the day, PM concentration and meteorological conditions during the period between July and September 2014. PM and black smoke samples were collected on cellulose nitrate membrane filters during the daytime (8.00 am - 20.00 pm and the nighttime (20.00 pm - 8.00 am. PMs, filters were eluted in buffer phosphate and aliquots were spread plated onto the surfaces of trypticase soya agar, malt extract agar, and starch casein agar media for counting bacteria, fungi and actinomycetes associated PM, respectively. Airborne microorganisms were collected using an Andersen two stage impactor sampler equipped with Petri plates containing the previously mentioned agar media. The Andersen two-stage viable cascade impactor sampler separates particles into coarse (≥8 µm and fine (≤8 µm size fractions. Airborne microorganisms were taken at three day time-scales: in the morning (8 am - 10 am, at the afternoon (13.00 pm - 16.00 pm and in the evening (22.00 pm - 1.00 am. The average concentrations of PM (149.5 µg/m3 and smoke (57.03 µg/m3 were higher in the daytime and nighttime, respectively. The greatest concentrations of microorganisms associated PM were found in the daytime, however the peak concentration of airborne microorganisms was found in the evening time. Fine microbial fraction constituted ~60% - 75.9% of the total microbial concentrations. Positive correlations were found between bacteria with PM concentration in the daytime and meteorological conditions at the nighttime. Temperature and relative humidity positively affected survivability of microorganisms associated PM at the nighttime and airborne fungi as well. This study helps understand distribution pattern of microorganisms in the atmosphere of a hot-arid environment.

  17. Mechanical behavior of ceramic composite hot-gas filters after exposure to severe environments

    Energy Technology Data Exchange (ETDEWEB)

    Pysher, D.J.; Weaver, B.L.; Smith, R.G. [Ceramic Technology Center, St. Paul, MN (United States)] [and others

    1995-08-01

    A novel type of hot-gas filter based on a ceramic fiber reinforced ceramic matrix has been developed, as reported at previous Fossil Energy Materials Conferences, through research activities at Oak Ridge National Laboratory (ORNL) and at the 3M Company. Simulated testing has been done at the Westinghouse Science and Technology Center. This filter technology has been extended to full size, 60 mm OD by 1.5 meter long candle filters and a commercially viable process for producing the filters has been developed filters are undergoing testing and demonstration use throughout the world for applications in pressurized fluidized-bed combustion (PFBC) and integrated gasification combined cycle (IGCC) plants. Demonstration tests of this ceramic composite filter along with other filters are in progress at the Tidd PFBC plant Mechanical tests were performed on the 3 M brand Ceramic Composite Candle Filter after exposure to various corrosive environments in order to assess its ability to function as a hot gas filter in coal-fired applications. Due to the different construction of ceramic composite filters and the thin composite wall versus the typical thick-walled monolithic filter, standard mechanical property tests had to be refined or modified to accurately determine the filters properties. These tests and filter property results will be described Longitudinal tensile and diametral O-ring compression tests were performed on as-produced candle filters as well as on filters which had been exposed to various environments. The exposures were for 1000 hrs at 850{degrees}C in wet air, in wet air containing Na{sub 2}CO{sub 3}, and in wet air containing NaCl. In addition, a filter which bad been coated with ash (Old Grimethorpe) was exposed to wet air at 850{degrees}C for 1000 hours.

  18. Clean hot water drilling for exploration of the Antarctic deep subglacial environment

    Science.gov (United States)

    Makinson, K.; Pearce, D.; Hodgson, D.; Bentley, M.; Smith, A.; Tranter, M.; Rose, M. C.; Ross, N.; Mowlem, M. C.; Parnell, J.; Siegert, M. J.

    2015-12-01

    Overlain by several kilometres of ice, the subglacial environments deep beneath the Antarctic Ice Sheet are regarded as extreme habitats for microbial life and repositories of important paleoclimate records. Of significant scientific interest, yet remaining largely unexplored, accessing and sampling these environments presents several challenges to existing drilling technologies. With over half of the ice sheet believed to be resting on a wet bed, much of it part of a hydrological drainage network, accessing of this environment must conform to international environmental contamination protocols. This makes hot water drilling the most viable option for clean, fast, access through thick ice. After two decades of planning, involving the development of drilling techniques for subglacial access, instrument design and logistics set up, significant progress has been made in attempts to directly access, measure, and sample subglacial lakes and sediments. Combining the experiences from the notable setbacks and successes, as well as recent field testing for this drilling technique, the most practical technical options and operational procedures for future clean entry into Subglacial Lake Ellsworth and other deep (>3000 m) access targets will be presented.

  19. Special Testing for Modules Deployed in Hot Use Environments - Are We Doing This in a Low-Cost Way?

    Energy Technology Data Exchange (ETDEWEB)

    Repins, Ingrid; Jordan, Dirk; Bosco, Nick; Flueckiger, Chris

    2016-09-12

    The proposed new IEC standard will address the test temperature requirements in IEC 61215 (module design), IEC 61730 (module safety), IEC 62790 (junction box safety) and IEC 62852 (connectors), and will provide guidelines to modify temperature limits in four existing standards to better describe module performance in hotter climates. This workshop includes four presentations: Special Testing for Modules Deployed in Hot Use Environments - Are We Doing This in a Low-Cost Way?, Experimental Evidence, Why the highest temperatures are the most stressful to PV modules during thermal cycling, and Safety Aspects for Modules Deployed in Hot Use Environments.

  20. DQO Summary Report for 324 and 327 Building Hot Cells D4 Project Waste Characterization

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Lee

    2006-02-06

    This data quality objective (DQO) summary report provides the results of the DQO process conducted for waste characterization activities for the 324 and 327 Building hot cells decommission, deactivate, decontaminate, and demolish activities. This DQO summary report addresses the systems and processes related to the hot cells, air locks, vaults, tanks, piping, basins, air plenums, air ducts, filters, an adjacent elements that have high dose rates, high contamination levels, and/or suspect transuranic waste, which will require nonstandard D4 techniques.

  1. Evaluating the Effectiveness of Cooling Vest in a Hot and Humid Environment.

    Science.gov (United States)

    Yi, Wen; Zhao, Yijie; Chan, Albert P C

    2017-05-01

    This study aims to evaluate the effectiveness of a newly designed hybrid cooling vest for construction workers in alleviating heat stress. Two types of cooling vests, namely, a commonly worn Vest A and a newly designed Vest B, were tested in a climatic chamber environment (34.0°C temperature, 60% relative humidity, and 0.4 m s-1 air velocity) using a sweating thermal manikin. Four test scenarios were included: fan off with no phase change materials (PCMs) (Fan-off), fan on with no PCMs (Fan-on), fan off with completely solidified PCMs (PCM + Fan-off), and fan on with completely solidified PCMs (PCM + Fan-on). Test results showed that Vests A and B provided a continuous cooling effect during the 3-h test. The average cooling power for the torso region of Vest B was 67 W, which was higher than that of Vest A (56 W). The addition of PCMs offered a cooling effect of approximately 60 min. Ventilation fans considerably improved the evaporative heat loss compared with the Fan-off condition. The newly designed hybrid cooling vest (Vest B) may be an effective means to reduce heat strain and enhance work performance in a hot and humid environment.

  2. Haptic shared control improves hot cell remote handling despite controller inaccuracies

    Energy Technology Data Exchange (ETDEWEB)

    Oosterhout, J. van, E-mail: J.vanOosterhout@differ.nl [Delft University of Technology, Faculty of 3mE, BioMechanical Engineering Department, Mekelweg 2, 2628 CD Delft (Netherlands); Abbink, D.A. [Delft University of Technology, Faculty of 3mE, BioMechanical Engineering Department, Mekelweg 2, 2628 CD Delft (Netherlands); Koning, J.F. [Heemskerk Innovative Technology B.V., Jonckerweg 12, 2201 DZ Noordwijk (Netherlands); Boessenkool, H. [FOM Institute DIFFER (Dutch Institute for Fundamental Energy Research), Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Wildenbeest, J.G.W. [Delft University of Technology, Faculty of 3mE, BioMechanical Engineering Department, Mekelweg 2, 2628 CD Delft (Netherlands); Heemskerk Innovative Technology B.V., Jonckerweg 12, 2201 DZ Noordwijk (Netherlands); Heemskerk, C.J.M. [Heemskerk Innovative Technology B.V., Jonckerweg 12, 2201 DZ Noordwijk (Netherlands)

    2013-10-15

    Highlights: Haptic shared control is generally based upon perfect environment information. A realistic implementation holds model errors with respect to the environment. Operators were aided with inaccurate guiding forces during a peg-in-hole task. The results showed that small guiding inaccuracies still aid the operator. -- Abstract: A promising solution to improve task performance in ITER hot cell remote handling is the use of haptic shared control. Haptic shared control can assist the human operator along a safe and optimal path with continuous guiding forces from an intelligent autonomous controller. Previous research tested such controllers with accurate knowledge of the environment (giving flawless guiding forces), while in a practical implementation guidance forces will sometimes be flawed due to inaccurate models or sensor information. This research investigated the effect of zero and small (7.5 mm) errors on task performance compared to normal (unguided) operation. In a human factors experiment subjects performed a three dimensional virtual reality peg-in-hole type task (30 mm diameter; 0.1 mm clearance), with and without potentially flawed haptic shared control. The results showed that the presence of guiding forces, despite of small guiding errors, still improved task performance with respect to unguided operations.

  3. Aandachtspunten voor een optimale voorbereiding: Inspanning in de warmte (Exercise in a hot environment: Strategies for an optimal preparation)

    NARCIS (Netherlands)

    Rietjens, G.J.W.M.; Arensbergen, W. van; Daanen, H.A.M.

    2004-01-01

    One of the underlying factors responsible for performance decrement during exercise in a hot environment appears to be an elevated core temperature. For this reason, strategies that minimise the rise in core temperature during exercise in the heat are likely to be effective in enhancing exercise

  4. Constant, cycling, hot and cold thermal environments: strong effects on mean viability but not on genetic estimates

    DEFF Research Database (Denmark)

    Ketola, Tarmo; Kellermann, Vanessa; Kristensen, Torsten Nygård

    2012-01-01

    It has frequently been suggested that trait heritabilities are environmentally sensitive, and there are genetic trade-offs between tolerating different environments such as hot and cold or constant and fluctuating temperatures. Future climate predictions suggest an increase in both temperatures...

  5. Advanced Manufacturing Technologies (AMT): Additive Manufactured Hot Fire Planning and Testing in GRC Cell 32 Project

    Science.gov (United States)

    Fikes, John C.

    2014-01-01

    The objective of this project is to hot fire test an additively manufactured thrust chamber assembly TCA (injector and thrust chamber). GRC will install the additively manufactured Inconel 625 injector, two additively manufactured (SLM) water cooled Cu-Cr thrust chamber barrels and one additively manufactured (SLM) water cooled Cu-Cr thrust chamber nozzle on the test stand in Cell 32 and perform hot fire testing of the integrated TCA.

  6. Ingestion of a Cold Temperature/Menthol Beverage Increases Outdoor Exercise Performance in a Hot, Humid Environment

    OpenAIRE

    Tran Trong, Than; Riera, Florence; Rinaldi, K?vin; Briki, Walid; Hue, Olivier

    2015-01-01

    Purpose A recent laboratory study demonstrated that the ingestion of a cold/menthol beverage improved exercise performance in a hot and humid environment during 20 km of all-out cycling. Therefore, the aim of this study was to determine whether the ingestion of cold water/ice-slurry with menthol would improve performance in hot and humid outdoor conditions. Methods Ten trained males completed three trials of five blocks consisting of 4-km cycling and 1.5-km running. During warm-up, every bloc...

  7. Shrinkage modeling of concrete reinforced by palm fibres in hot dry environments

    Science.gov (United States)

    Akchiche, Hamida; Kriker, Abdelouahed

    2017-02-01

    The cement materials, such as concrete and conventional mortar present very little resistance to traction and cracking, these hydraulic materials which induces large withdrawals on materials and cracks in structures. The hot dry environments such as: the Saharan regions of Algeria, Indeed, concrete structures in these regions are very fragile, and present high shrinkage. Strengthening of these materials by fibers can provide technical solutions for improving the mechanical performance. The aim of this study is firstly, to reduce the shrinkage of conventional concrete with its reinforcement with date palm fibers. In fact, Algeria has an extraordinary resources in natural fibers (from Palm, Abaca, Hemp) but without valorization in practical areas, especially in building materials. Secondly, to model the shrinkage behavior of concrete was reinforced by date palm fibers. In the literature, several models for still fiber concrete were founded but few are offers for natural fiber concretes. To do so, a still fiber concretes model of YOUNG - CHERN was used. According to the results, a reduction of shrinkage with reinforcement by date palm fibers was showed. A good ability of molding of shrinkage of date palm reinforced concrete with YOUNG - CHERN Modified model was obtained. In fact, a good correlation between experimental data and the model data was recorded.

  8. Hydration: special issues for playing football in warm and hot environments.

    Science.gov (United States)

    Shirreffs, S M

    2010-10-01

    The high metabolic rates and body temperatures sustained by football players during training and matches causes sweating--particularly when in warm or hot environments. There is limited published data on the effects of this sweat loss on football performance. The limited information available, together with knowledge of the effects of sweat loss in other sports with skill components as well as endurance and sprint components, suggests that the effects of sweating will be similar as in these other activities. Therefore, the generalization that, on average, a body mass reduction equivalent to 2% should be the acceptable limit of sweat losses seems reasonable. This magnitude and more, of sweat loss is a common occurrence for some players. Sodium is the main electrolyte lost in sweat but there is large variability in sodium losses between players. However, the extent of sodium losses in some players may be such that its replacement is warranted for these players. Although football is a team sport, the great individual variability in sweat and electrolyte losses of players in the same training session or match dictates that individual monitoring to determine individual water and electrolyte requirements should be an essential part of a player's nutrition strategy. © 2010 John Wiley & Sons A/S.

  9. Free Vibration of Fiber Composite Thin Shells in a Hot Environment

    Science.gov (United States)

    Gotsis, Pascal K.; Guptill, James D.

    1995-01-01

    Results are presented of parametric studies to assess the effects of various parameters on the free vibration behavior (natural frequencies) of (plus or minus theta)2, angle-ply fiber composite thin shells in a hot environment. These results were obtained by using a three-dimensional finite element structural analysis computer code. The fiber composite shell is assumed to be cylindrical and made from T-300 graphite fibers embedded in an intermediate-modulus high-strength matrix (IMHS). The residual stresses induced into the laminated structure during curing are taken into account. The following parameters are investigated: the length and the thickness of the shell, the fiber orientations, the fiber volume fraction, the temperature profile through the thickness of the laminate and the different ply thicknesses. Results obtained indicate that: the fiber orientations and the length of the laminated shell had significant effect on the natural frequencies. The fiber volume fraction, the laminate thickness and the temperature profile through the shell thickness had a weak effect on the natural frequencies. Finally, the laminates with different ply thicknesses had insignificant influence on the behavior of the vibrated laminated shell.

  10. Physiological Responses of Slow-Growing Chickens under Diurnally Cycling Temperature in a Hot Environment

    Directory of Open Access Journals (Sweden)

    T Mutibvu

    Full Text Available ABSTRACT Free-range chicken production has significantly increased in recent years and it often entails exposing birds to cyclic environmental conditions. The objective of the current study was to investigate the effect of bird strain and sex, and rearing system on the physiological responses of Potchefstroom Koekoek (PK, Ovambo (OV and Naked Neck (NN chickens reared in a hot environment. Body weight (BW, rectal temperature (RT, respiratory rate (RR and heart rate (HR were determined weekly for 4 weeks, in 3 slow-growing chicken strains under cyclic environmental conditions. A total of 288, 20-week old Potchefstroom Koekoek (PK, Ovambo (OV and Naked Neck (NN chickens were separated by sex and allocated to extensive and intensive rearing systems. Ambient temperature and relative humidity (RH were used to compute a temperature humidity index (THI. A Proc MIXED model was used to analyze fixed effects and a linear regression model was fitted to test the relationship between THI and response parameters. All factors studied influenced (p0.05 RT. Higher BW (p0.05. Week and rearing system affected (p>0.05 RR. THI showed significant correlation with RR and HR. THI was higher in intensive than extensive rearing. Physiological responses of PK, OV and NN are comparable under similar rearing conditions.

  11. Assessment of an active liquid cooling garment intended for use in a hot environment.

    Science.gov (United States)

    Bartkowiak, Grazyna; Dabrowska, Anna; Marszalek, Anna

    2017-01-01

    This paper discusses the construction of a designed active liquid cooling garment (LCG) that has been developed in order to reduce thermal discomfort of persons working in hot environments. It consists of clothing with a tube system distributing a cooling liquid, a sensor measuring the microclimate under the clothing, and a portable cooling unit with a module controlling the temperature of the cooling liquid depending on the microclimate temperature under the clothing. The LCG was validated through tests on volunteers in a climatic chamber at 30 °C, a relative humidity of 40%, and an air movement rate of 0.4 m/s. The obtained test results confirmed the beneficial effects of the cooling system used on mean weighted skin temperature, the physical parameters of the microclimate under the clothing, and the participants' subjective assessments, as well as confirmed that the functioning of the control system regulating liquid temperature in the LCG was correct. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Does living and working in a hot environment induce clinically relevant changes in immune function and voluntary force production capacity?

    Science.gov (United States)

    Knez, Wade; Girard, Olivier; Racinais, Sebastien; Walsh, Andrew; Gaoua, Nadia; Grantham, Justin

    2014-01-01

    This study investigated the effect of living (summer vs. winter) and working (morning vs. afternoon) in a hot environment on markers of immune function and forearm strength. Thirty-one healthy male gas field employees were screened before (between 05:30 and 07:00) and after their working day (between 15:30 and 17:00) during both seasons. Body core temperature and physical activity were recorded throughout the working days. The hot condition (i.e. summer) led a higher (p≤0.05) average body core temperature (~37.2 vs. ~37.4 °C) but reduced physical activity (-14.8%) during the work-shift. Our data showed an increase (p≤0.05) in lymphocyte and monocyte counts in the summer. Additionally, work-shift resulted in significant (p≤0.001) changes in leukocytes, lymphocytes and monocytes independently of the environment. Handgrip (p=0.069) and pinch (p=0.077) forces tended to be reduced from pre-to post-work, while only force produced during handgrip manoeuvres was significantly reduced (p≤0.05) during the hot compared to the temperate season. No interactions were observed between the environment and work-shift for any marker of immune function or forearm strength. In summary, working and living in hot conditions impact on markers of immune function and work capacity; however by self-regulating energy expenditure, immune markers remained in a healthy reference range.

  13. Standard guide for mechanical drive systems for remote operation in hot cell facilities

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 Intent: 1.1.1 The intent of this standard is to provide general guidelines for the design, selection, quality assurance, installation, operation, and maintenance of mechanical drive systems used in remote hot cell environments. The term mechanical drive systems used herein, encompasses all individual components used for imparting motion to equipment systems, subsystems, assemblies, and other components. It also includes complete positioning systems and individual units that provide motive power and any position indicators necessary to monitor the motion. 1.2 Applicability: 1.2.1 This standard is intended to be applicable to equipment used under one or more of the following conditions: 1.2.1.1 The materials handled or processed constitute a significant radiation hazard to man or to the environment. 1.2.1.2 The equipment will generally be used over a long-term life cycle (for example, in excess of two years), but equipment intended for use over a shorter life cycle is not excluded. 1.2.1.3 The ...

  14. Reversible electron-hole separation in a hot carrier solar cell

    Science.gov (United States)

    Linke, Heiner

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron-hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. To achieve this, we consider a highly selective energy filter such as a quantum dot embedded into a one-dimensional conductor. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. In addition this theoretical analysis, I will also report on first experimental results in a nanowire-based energy filter device. Ref: S Limpert, S Bremner, and H Linke, New J. Phys 17, 095004 (2015)

  15. 324 and 325 Building hot cell cleanout program: Decontamination of C-Cell

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Y.B.; Holton, L.K. Jr.

    1989-10-01

    During FY 1989 the decontamination of C-Cell of Hanford's 324 Building was completed as part of the 324 and 325 Building Hot Cell Cleanout Program sponsored by the DOE Nuclear Energy's Surplus Facilities Management Program. The decontamination effort was completed using a series of remote and contact decontamination techniques. Initial radiation readings in C-Cell averaged 50 rad/hr and were reduced remotely to less than 200 mrad/hr using an alkaline foam cleaner followed by a 5000-psi water flush. Contact decontamination was then permissible using ultra high-pressure water, at 36,000 psi, further reducing the average radiation level in the cell to less than 86 mrem/hr. The approach used in decontaminating C-Cell resulted in a savings in radiation exposure of 87% and a cost savings of 39% compared to a hands-on procedure used in A-Cell, 324 Building in 1987. The radiation dose and the costs to achieve a 244-fold reduction in radiation contamination were 1.65 mrem per ft{sup 2} and $96 per ft{sup 2} of cell surface area. 14 figs., 4 tabs.

  16. Decontamination of hot cells K-1, K-3, M-1, M-3, and A-1, M-Wing, Building 200: Project final report Argonne National Laboratory-East

    Energy Technology Data Exchange (ETDEWEB)

    Cheever, C.L.; Rose, R.W.

    1996-09-01

    The purpose of this project was to remove radioactively contaminated materials and equipment from the hot cells, to decontaminate the hot cells, and to dispose of the radioactive waste. The goal was to reduce stack releases of Rn-220 and to place the hot cells in an emptied, decontaminated condition with less than 10 {micro}Sv/h (1 mrem/h) general radiation background. The following actions were needed: organize and mobilize a decontamination team; prepare decontamination plans and procedures; perform safety analyses to ensure protection of the workers, public, and environment; remotely size-reduce, package, and remove radioactive materials and equipment for waste disposal; remotely decontaminate surfaces to reduce hot cell radiation background levels to allow personnel entries using supplied air and full protective suits; disassemble and package the remaining radioactive materials and equipment using hands-on techniques; decontaminate hot cell surfaces to remove loose radioactive contaminants and to attain a less than 10 {micro}Sv/h (1 mrem/h) general background level; document and dispose of the radioactive and mixed waste; and conduct a final radiological survey.

  17. Review of tritium confinement and atmosphere detritiation system in hot cells complex

    Energy Technology Data Exchange (ETDEWEB)

    Rizzello, Claudio [TESI Sas, Servizi di ingegneria per la chimica, la sicurezza e l' ambiente, Via Bolzano 28 00198, Roma (Italy); Borgognoni, Fabio; Pinna, Tonio [ENEA, Dip. Fusione Tecnologie e Presidio Nucleare, C.R. ENEA Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Tosti, Silvano [ENEA, Dip. Fusione Tecnologie e Presidio Nucleare, C.R. ENEA Frascati, Via E. Fermi 45, 00044 Frascati (Italy)], E-mail: tosti@frascati.enea.it

    2010-01-15

    The tritium confinement strategy adopted during the past years in the ITER hot cell building is compared to the safety requirements given by the standard ISO-17873 'Nuclear facilities - criteria for the design and operation of ventilation systems for nuclear installations other than nuclear reactors'. In fact, this is the reference safety guideline recommended by French licensing authorities. Several features of the considered design of the hot cell building are not in agreement with these guidelines. Main discrepancies concern the zoning of the hot cell complex, the flow rates of ventilation, and the possibility to recycle the room atmosphere and to detritiate the effluent air. These aspects are discussed together with some proposed modifications of the design.

  18. A cooling vest for working comfortably in a moderately hot environment.

    Science.gov (United States)

    Nishihara, Naoe; Tanabe, Shin-ichi; Hayama, Hirofumi; Komatsu, Masayoshi

    2002-01-01

    To alleviate worker's thermal discomfort in a moderately hot environment, a new cooling vest was designed and proposed in this paper. To investigate the effect of the cooling vest and to collect the knowledge for the design of comfortable cooling vest, subjective experiments were conducted. Two kinds of cooling vests, the new one and the commercially available one, were used for comparison. The new cooling vest had more insulation and its surface temperature was higher than the commercially available one. Experiments were performed in the climatic chamber where operative temperature was controlled at 30.2 degrees C and relative humidity was at 37% under still air. In addition, experiment without cooling vest was carried out as a control condition. The results obtained in these experiments were as follow: 1) By wearing both types of cooling vest, the whole body thermal sensation was closer to the neutral conditions than those without cooling vest. This effect was estimated to be equal to the 5.7 degrees C decrement of operative temperature. The subjects felt more comfortable with the cooling vest than without it. They felt more thermally acceptable than that without cooling vest. Wearing the cooling vest was useful to decrease the sweating sensation. 2) The local discomfort was observed when the local thermal sensation was "cool" approximately "cold" with the cooling vest. 3) The new cooling vest kept the skin temperature at chest at about 32.6 degrees C. On the other hand, by wearing the commercially available one, it lowered to about 31.1 degrees C. By wearing the new cooling vest, there was a tendency that local thermal sensation vote was higher and local comfort sensation vote was more comfortable than those of the condition wearing the commercially available one. It is important for the design of a comfortable cooling garment to prevent over-cool down from the body.

  19. Relevance of individual characteristics for thermoregulation during exercise in a hot-dry environment.

    Science.gov (United States)

    Coso, Juan Del; Hamouti, Nassim; Ortega, Juan F; Fernández-Elías, Valetín E; Mora-Rodríguez, Ricardo

    2011-09-01

    The aim of this study was to investigate the relevance of individual characteristics for thermoregulation during prolonged cycling in the heat. For this purpose, 28 subjects cycled for 60 min at 60% VO(2peak) in a hot-dry environment (36 ± 1°C; 25 ± 2% relative humidity, airflow 2.5 m/s). Subjects had a wide range of body mass (99-43 kg), body surface area (2.2-1.4 m(2)), body fatness (28-5%) and aerobic fitness level (VO(2peak) = 5.0-2.1 L/min). At rest and during exercise, rectal and mean skin temperatures were measured to calculate the increase in body temperature (ΔT (body)) during the trial. Net metabolic heat production (M (NET)) and potential heat loss (by means of evaporation, radiation and convection) were calculated. Although subjects exercised at the same relative intensity, ΔT (body) presented high between-subjects variability (range from 0.44 to 1.65°C). ΔT (body) correlated negatively with body mass (r = -0.49; P 0.05). ΔT (body) positively correlated with the body surface area/mass ratio (r = 0.46; P < 0.01) and the difference between M (NET) and potential heat loss (r = 0.56; P < 0.01). In conclusion, a large body size (mass and body surface area) is beneficial to reduce ΔT (body) during cycling exercise in the heat. However, subjects with higher absolute heat production (more aerobically fit) accumulate more heat because heat production may exceed potential heat loss (uncompensability).

  20. Hot topics in alkaline exchange membrane fuel cells

    Science.gov (United States)

    Serov, Alexey; Zenyuk, Iryna V.; Arges, Christopher G.; Chatenet, Marian

    2018-01-01

    The tremendous progress from the first discovery of fuel cell principles by Sir William Robert Grove in 1839 [1] and independent observation of electricity generated in electrochemical reaction of hydrogen and air by a Swiss scientist Christian F. Shoenbein [2] to the recent breakthroughs in the fuel cell field resulted in the appearance of this clean energy technology around us. Indeed, fuel cell technology undoubtedly has entered into our life with the first introduction of Toyota Mirai Fuel Cell Vehicle (FCV) by Toyota Motor Co. in December of 2014 [3,4]. This FCV is commercially available and can be purchased in several countries. However, its sticker price of 57,500 substantially limits the number of customers that can purchase it. There are numerous factors that contribute to the high cost of fuel cell stack, however the price of platinum and platinum alloys is the main contributor [5].

  1. Biophotonics sensor acclimatization to stem cells environment

    Science.gov (United States)

    Mohamad Shahimin, Mukhzeer

    2017-11-01

    The ability to discriminate, characterise and purify biological cells from heterogeneous population of cells is fundamental to numerous prognosis and diagnosis applications; often forming the basis for current and emerging clinical protocols in stem cell therapy. Current sorting approaches exploit differences in cell density, specific immunologic targets, or receptor-ligand interactions to isolate particular cells. Identification of novel properties by which different cell types may be discerned and of new ways for their selective manipulation are clearly fundamental components for improving sorting methodologies. Biophotonics sensor developed by our team are potentially capable of discriminating cells according to their refractive index (which is highly dependable on the organelles inside the cell), size (indicator to cell stage) and shape (in certain cases as an indicator to cell type). The sensor, which already discriminate particles efficiently, is modified to acclimatize into biological environment, especially for stem cell applications.

  2. Bioreactor Engineering of Stem Cell Environments

    Science.gov (United States)

    Tandon, Nina; Marolt, Darja; Cimetta, Elisa; Vunjak-Novakovic, Gordana

    2013-01-01

    Stem cells hold promise to revolutionize modern medicine by development of new therapies, disease models and drug screening systems. Standard cell culture systems have limited biological relevance because they do not recapitulate the complex 3-dimensional interactions and biophysical cues that characterize the in vivo environment. In this review, we discuss the current advances in engineering stem cell environments using novel biomaterials and bioreactor technologies. We also reflect on the challenges the field is currently facing with regard to translation of stem cell based therapies into the clinic. PMID:23531529

  3. The influence of a hot environment on parental cooperation of a ground-nesting shorebird, the Kentish plover Charadrius alexandrinus

    Directory of Open Access Journals (Sweden)

    Javed Salim

    2010-01-01

    Full Text Available Abstract Background Parental care often increases offspring survival, but is costly to the parents. A trade-off between the cost and benefit of care is expected, so that when care provisioning by both parents is essential for the success of young, for instance in extremely cold or hot environments, the parents should rear their young together. We investigated the latter hypothesis in a ground nesting shorebird, the Kentish plover Charadrius alexandrinus in an extremely hot environment, the Arabian Desert. Midday ground temperature was often above 50°C in our study site in Abu Dhabi (United Arab Emirates, thus leaving the eggs unattended even for a few minute risks overheating and death of embryos. Results Through the use of video surveillance systems we recorded incubation routines of male and female Kentish plovers at 28 nests over a full day (24 h. We show that ambient temperature had a significant influence on incubation behaviour of both sexes, and the relationships are often non-linear. Coordinated incubation between parents was particularly strong in midday with incubation shared approximately equally between the male and the female. The enhanced biparental incubation was due to males increasing their nest attendance with ambient temperature. Conclusions Our results suggest biparental care is essential during incubation in the Kentish plover in extremely hot environments. Shared incubation may also help the parents to cope with heat stress themselves: they can relieve each other frequently from incubation duties. We suggest that once the eggs have hatched the risks associated with hot temperature are reduced: the chicks become mobile, and they gradually develop thermoregulation. When biparental care of young is no longer essential one parent may desert the family. The relaxed demand of the offspring may contribute to the diverse breeding systems exhibited by many shorebirds.

  4. Haptic shared control improves hot cell remote handling despite controller inaccuracies

    NARCIS (Netherlands)

    van Oosterhout, J.; Abbink, D. A.; Koning, J. F.; Boessenkool, H.; Wildenbeest, J. G. W.; Heemskerk, C. J. M.

    2013-01-01

    A promising solution to improve task performance in ITER hot cell remote handling is the use of haptic shared control. Haptic shared control can assist the human operator along a safe and optimal path with continuous guiding forces from an intelligent autonomous controller. Previous research tested

  5. The hot cell laboratories for material investigations of the Institute for Safety Research

    Energy Technology Data Exchange (ETDEWEB)

    Viehrig, H.W.

    1998-10-01

    Special facilities for handling and testing of irradiated specimens are necessary, to perform the investigation of activated material. The Institute for Safety Research has two hot cell laboratories: - the preparation laboratory and - the materials testing laboratory. This report is intended to give an overview of the available facilities and developed techniques in the laboratories. (orig.)

  6. Deposition from Ultra-Low Volume Application of Public Health Insecticides in a Hot Desert Environment.

    Science.gov (United States)

    Fisher, Michael L; Hoel, David F; Farooq, Muhammad; Walker, Todd W

    2015-06-01

    Three insecticides commonly used for mosquito and sand fly control were applied 30 min to 3 h after sunset during June and July 2010, at Camp Buehring, Kuwait, to determine the relative quantity of pesticides to height and distance traveled in a hot desert environment. A BVA dilution oil was used for the control. Oil-based adulticides were sprayed using a truck-mounted Curtis DynaFog Maxi-Pro 4 ultra-low volume (ULV) sprayer. Malathion (Fyfanon ULV, 96% active ingredient [AI]), resmethrin (Scourge 4+12, 4% AI), pyrethrins (ULD BP-300, 3% AI), and BVA Spray 13 (100% refined petroleum distillate) were mixed with Uvitex optical brightener fluorescent dye and applied at 2 speeds on evenings when wind speed was less than 16.1 km/h (10 mph). Collection targets using biodegradable cotton ribbons (1 m×2.5 cm) were later read with a fluorometer to quantify the amount of insecticide deposited on targets set at heights of 15.2, 76.2, and 152.4 cm (6, 30, and 60 in.) and distances of 1.5, 6.1, 15.2, 30.5, 61.0, and 91.4 m (5, 20, 50, 100, 200, and 300 ft). Mean insecticide deposition across all distances was 31% on 76.2-cm targets and 49% on 152.4-cm targets, while 15.2-cm targets typically collected <20% of test spray. Mean ground temperatures were typically within 5°C of air temperatures at 152.4 cm and within 1 to 5°C of air at 15.2 cm or 76.2 cm. Collectively, mean insecticide deposition was 80% at or above 76.2 cm for all insecticides. This finding may explain in part why control of low-flying phlebotomine sand flies with ULV insecticides has been met with less than optimal success by US military forces deployed in the Middle East.

  7. Hot Cell Liners Category of Transuranic Waste Stored Below Ground within Area G

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Robert Wesley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hargis, Kenneth Marshall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-01

    A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreement between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP). This report summarizes available information on the origin, configuration, and composition of the waste containers within the Hot Cell Liners category; their physical and radiological characteristics; the results of the radioassays; and the justification to reclassify the five containers as LLW rather than TRU waste.

  8. Dendritic cell-based vaccine efficacy: aiming for hot spots

    Directory of Open Access Journals (Sweden)

    Gabriela Andrea Pizzurro

    2015-03-01

    Full Text Available Many approaches for cancer immunotherapy have targeted dendritic cells (DC, directly or indirectly, for the induction of antitumor immune responses. DC-based vaccines have been developed using a wide variety of ex vivo DC culture conditions, antigen source and loading strategies, maturation agents and routes of vaccination. Adjuvants are used to activate innate immune cells at the vaccine injection site, to promote antigen transport to the draining lymph nodes (LNs and to model adaptive immune responses. Despite years of effort, the effective induction of strong and durable antitumor T cell responses in vaccinated patients remains a challenge. The study of vaccine interactions with other immune cells in the LNs and, more recently, in the injection site has opened new doors for understanding antitumor effector T cell licensing and function. In this review, we will briefly discuss the relevant sites and up-to-date facts regarding possible targets for antitumor vaccine refinement. We will focus on the processes taking place at the injection site, adjuvant combinations and their role in DC-based vaccines LN homing and modeling vaccine-induced immune responses capable of controlling tumor growth and generating immune memory.

  9. Hot Corrosion of Inconel 625 Overlay Weld Cladding in Smelting Off-Gas Environment

    Science.gov (United States)

    Mohammadi Zahrani, E.; Alfantazi, A. M.

    2013-10-01

    Degradation mechanisms and hot corrosion behavior of weld overlay alloy 625 were studied. Phase structure, morphology, thermal behavior, and chemical composition of deposited salt mixture on the weld overlay were characterized utilizing XRD, SEM/EDX, DTA, and ICP/OES, respectively. Dilution level of Fe in the weldment, dendritic structure, and degradation mechanisms of the weld were investigated. A molten phase formed on the weld layer at the operating temperature range of the boiler, which led to the hot corrosion attack in the water wall and the ultimate failure. Open circuit potential and weight-loss measurements and potentiodynamic polarization were carried out to study the hot corrosion behavior of the weld in the simulated molten salt medium at 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). Internal oxidation and sulfidation plus pitting corrosion were identified as the main hot corrosion mechanisms in the weld and boiler tubes. The presence of a significant amount of Fe made the dendritic structure of the weld susceptible to preferential corrosion. Preferentially corroded (Mo, Nb)-depleted dendrite cores acted as potential sites for crack initiation from the surface layer. The penetration of the molten phase into the cracks accelerated the cracks' propagation mainly through the dendrite cores and further crack branching/widening.

  10. Electron-phonon energy transfer in hot-carrier solar cells

    OpenAIRE

    Luque López, Antonio; Martí Vega, Antonio

    2010-01-01

    Hot-carrier solar cells may yield very high efficiency if the heat transfer from electrons to phonons is low enough. In this paper we calculate this heat transfer for the two inelastic mechanisms known to limit the electric conductivity: the multi-valley scattering in non-polar semiconductors and the coupling of electrons to longitudinal optical phonons in polar semiconductors. Heat transfer is ruled by matrix elements deduced from electric conductivity measurements. The cell power extracted ...

  11. Hot Start to European Pluripotent Stem Cell Banking.

    Science.gov (United States)

    De Sousa, Paul A; Steeg, Rachel; Kreisel, Beate; Allsopp, Timothy E

    2017-07-01

    Achieving consistency in standards of access to and quality of human induced pluripotent stem cells has lagged behind their use. In Europe, a network of academic and industrial partners has been established to overcome this challenge. The experience reveals the devil in the detail of worthy ambitions informing future efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Hot gas flow cell for optical measurements on reactive gases

    DEFF Research Database (Denmark)

    Grosch, Helge; Fateev, Alexander; Nielsen, Karsten Lindorff

    2013-01-01

    was validated for high resolution measurements at temperatures of up to 800 K (527 degrees C) in the ultraviolet (UV) and infrared (IR) regions (190-20 000 nm). Verification of the gas temperature in the cell is provided by a thermocouple and emission/transmission measurements in the IR and UV regions. High......-resolution measurements are presented for the absorption cross-section of sulfur dioxide (SO2) in the UV range up to 773 K (500 degrees C)...

  13. Developments of Thermal Environment Techniques of Animal Housing in Hot Climate

    DEFF Research Database (Denmark)

    Zhang, Guoqiang; Bjerg, Bjarne Schmidt

    It is a challenge to create the satisfied indoor climate of farm animal housing in hot climate conditions by ventilation design and control. Facing to the global warming tendency, the challenge become event great. To overcome this challenge, an optimal indoor climate control system should be able...... cooling and ventilation techniques have been investigated and reported. In practices, however, different climate regions and farm animal species may request for different engineering solutions. To provide the fundamentals for an optimal design and control of ventilation system with feasible cooling...... approaches for hot climate farm animal housing, an overview of the available methods and techniques is given and potentials for integrations and optimizations of the methods are discussed....

  14. HotSense: a high temperature piezoelectric platform for sensing and monitoring in extreme environments (Conference Presentation)

    Science.gov (United States)

    Stevenson, Tim; Wines, Thomas; Martin, David; Vickers, William; Laws, Michael

    2016-04-01

    Effective monitoring of asset integrity subject to corrosion and erosion while minimizing the exposure of personnel to difficult and hazardous working environments has always been a major problem in many industries. One solution of this problem is permanently installed ultrasonic monitoring equipment which can continuously provide information on the rate of corrosion or cracking, even in the most severe environments and at extreme temperatures to prevent the need for shutdown. Here, a permanently installed 5 MHz ultrasonic monitoring system based on our HotSense® technology is designed and investigated. The system applicability for wall thickness, crack monitoring and weld inspection in high temperature environments is demonstrated through experimental studies on a range of Schedule 40 pipes at temperatures up to 350 °C continuously. The applicability for this technology to be distributed to Aerospace and Nuclear sectors are also explored and preliminary results discussed.

  15. Hot Soak

    OpenAIRE

    Goldwater, H.

    2005-01-01

    The DVD is documentation of Hot Soak, as performed at the Queen’s Hotel, Penzance, Cornwall in an en suite bathroom, for Tract: Live Art Festival, 2006, curated by Art Surgery/ Newlyn Art Gallery. Hot Soak was originally made for home, London, 2005. This piece marries an everyday environment (bathroom) with extraordinary materials (ice cubes/ dress bleeding red into water) creating the surreal. Sontag’s understanding of camp as a love of the unnatural, artifice and exaggeration, can be ci...

  16. Long-term perceptions of outdoor thermal environments in an elementary school in a hot-humid climate

    Science.gov (United States)

    Shih, Wen-Mei; Lin, Tzu-Ping; Tan, Ning-Xin; Liu, Mu-Hsien

    2017-09-01

    Previous studies on thermal comfort in school environments have focused more on indoor thermal environments than outdoor ones, thus providing a limited understanding of occupants' long-term thermal perceptions. Taiwan is located in a subtropical region, where it can be stiflingly hot outside in summer. This highlights the need to ensure proper thermal comfort on campus. In the present study, thermal environment parameters were measured and collected in several outdoor spaces of an elementary school in southern Taiwan. In addition, a questionnaire was used to explore occupants' long-term thermal perceptions of these spaces. During summer months, the physiological equivalent temperature (PET) of these outdoor spaces in over 60% of the daytime in summer between 10 a.m. and 4 p.m. was higher than 38 °C PET, indicating high heat stress. The results of occupants' long-term perceptions of the thermal comfort of these spaces suggested that dissatisfaction with thermal comfort was associated more with solar radiation than with wind speed. Finally, this study simulated a campus environment where more trees are planted and compared the thermal comfort indices before and after the simulation. The results indicated that this solution contributed to a decrease in the PET of these environments, thereby alleviating high heat stress. This study can inform the improvement of microclimates and thermal comfort during campus layout planning. Planting trees judiciously across a campus increases outdoor shades and creates outdoor spaces that are more comfortable and adaptable to hot weather conditions, thereby ensuring frequent use of these spaces.

  17. Chemical and biological properties of hot water extract from delipidated cells of Mycobacterium bovis strain BCG.

    Science.gov (United States)

    Sato, H; Yokosawa, A; Arai, H; Nagai, H; Kurita, K

    1976-09-01

    A water-soluble fraction was isolated from delipidated cells of Mycobacterium bovis strain BCG by extraction with hot water. Chemical analyses revealed that the above fraction presumably consisted of a peptidoglycan containing 5-10% of nucleic acids. When it was injected into guinea pigs with Freund's incomplete adjuvant plus egg white albumin as antigen, an increase of circulating antibody was observed as shown by the augmented titers of precipitin and hemagglutinin. The results of skin test and corneal reaction indicated that the fraction mentioned above induced delayed hypersensitivity to egg white albumin. Footpad reaction in mice demonstrated that the above fraction induced delayed hypersensitivity to sheep red blood cells. It was confirmed in addition that the adjuvant activity of this fraction was not due to the presence of nucleic acids. This adjuvant-active fraction was designated as HSA (hot-water soluble adjuvant.

  18. Development of maintenance equipment for nuclear material fabrication equipment in a highly active hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. J.; Yang, M. S.; Kim, K. H. and others

    2000-09-01

    This report presents the development of a maintenance system for a highly contaminated nuclear material handling equipment at a hot-cell. This maintenance system has mainly three subsystems - a gamma-radiation measurement module for detecting a gamma-radiation level and identifying its distribution in-situ, a dry-type decontamination device for cleaning up contaminated particles, and a maintenance chamber for isolating contaminated equipment. The mechanical design considerations, controller, capabilities and remote operation and manipulation of the maintenance system are described. Such subsystems developed were installed and tested in the IMEF (Irradiated Material Examination Facility) M6 hot-cell after mock-up tests and performed their specific tasks successfully.

  19. Evaluation of modular robot system for maintenance tasks in hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Pagala, Prithvi Sekhar, E-mail: ps.pagala@upm.es [Centre for Automation and Robotics UPM-CSIC (Spain); Ferre, Manuel, E-mail: m.ferre@upm.es [Centre for Automation and Robotics UPM-CSIC (Spain); Orona, Luis, E-mail: l.orona@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung (Germany)

    2014-10-15

    Highlights: •Modular robot deployment inside hot cell for remote manipulation evaluated. •Flexible and adaptable system for variety of tasks presented. •Uses in large workspaces and evolving requirements shown. -- Abstract: This work assesses the use of a modular robot system to perform maintenance and inspection tasks such as, remote flexible inspection, manipulation and cooperation with deployed systems inside the hot cell. A flexible modular solution for the inclusion in maintenance operations is presented. The proposed heterogeneous modular robotic system is evaluated using simulations of the prototype across selected robot configuration to perform tasks. Results obtained show the advantages and ability of the modular robot to perform the necessary tasks as well as its ability to adapt and evolve depending on the need. The simulation test case inside hot cell shows modular robot configuration, a two modular arm to perform tele-operation tasks in the workspace and a wheeled platform for inspection collaborating to perform tasks. The advantage of using re-configurable modular robot over conventional robot platforms is shown.

  20. Effect of hand cooling on body temperature, cardiovascular and perceptual responses during recumbent cycling in a hot environment.

    Science.gov (United States)

    Ruddock, Alan D; Tew, Garry A; Purvis, Alison J

    2017-07-01

    The purpose of this study was to quantify physiological and perceptual responses to hand immersion in water during recumbent cycling in a hot environment. Seven physically active males (body mass 79.8 ± 6.3 kg; stature 182 ± 5 cm; age 23 ± 3 years) immersed their hands in 8, 14 and 34°C water whilst cycling at an intensity (W) equivalent to 50% [Formula: see text]O2peak for 60 min in an environmental chamber (35°C, 50% relative humidity). 8 and 14°C water attenuated an increase in body temperature, and lowered cardiorespiratory and skin blood flow demands. These effects were considered to be practically beneficial (standardised effect size > 0.20). There was a tendency for 8 and 14°C to extend exercise duration versus 34°C (>7%). Heart rate, intestinal, mean skin and mean body temperature were less in 8°C compared to 14°C; these differences were considered practically beneficial. Augmented heat loss at the palm-water surface might enable cooler blood to return to the body and limit physiological strain. These findings provide a mechanistic basis for continuous hand cooling and indicate that endurance exercise in hot environments could be improved using this method. Future research should investigate its effectiveness during cycling and running performance.

  1. Case study of skin temperature and thermal perception in a hot outdoor environment.

    Science.gov (United States)

    Pantavou, Katerina; Chatzi, Evriklia; Theoharatos, George

    2014-08-01

    Focusing on the understanding and the estimation of the biometeorological conditions during summer in outdoor places, a field study was conducted in July 2010 in Athens, Greece over 6 days at three different sites: Syntagma Square, Ermou Street and Flisvos coast. Thermo-physiological measurements of five subjects were carried out from morning to evening for each site, simultaneously with meteorological measurements and subjective assessments of thermal sensation reported by questionnaires. The thermo-physiological variables measured were skin temperature, heat flux and metabolic heat production, while meteorological measurements included air temperature, relative humidity, wind speed, globe temperature, ground surface temperature and global radiation. The possible relation of skin temperature with the meteorological parameters was examined. Theoretical values of mean skin temperature and mean radiant temperature were estimated applying the MENEX model and were compared with the measured values. Two biometeorological indices, thermal sensation (TS) and heat load (HL)-were calculated in order to compare the predicted thermal sensation with the actual thermal vote. The theoretically estimated values of skin temperature were underestimated in relation to the measured values, while the theoretical model of mean radiant temperature was more sensitive to variations of solar radiation compared to the experimental values. TS index underestimated the thermal sensation of the five subjects when their thermal vote was 'hot' or 'very hot' and overestimated thermal sensation in the case of 'neutral'. The HL index predicted with greater accuracy thermal sensation tending to overestimate the thermal sensation of the subjects.

  2. Remarkable archaeal diversity detected in a Yellowstone National Park hot spring environment

    Energy Technology Data Exchange (ETDEWEB)

    Barns, S.M.; Fundyga, R.E.; Jeffries, M.W.; Pace, N.R. [Indiana Univ., Bloomington, IN (United States)

    1994-03-01

    Of the three primary phylogenetic domains - Archaea (archaebacteria), Bacteria (eubacteria), and Eucarya (eukaryotes) - Archaea is the least understood in terms of its diversity, physiologies, and ecological panorama. Although many species of Crenarchaeota have been isolated, they constitute a relatively tight-knit cluster of lineages in phylogenetic analyses of rRNA sequences. It seemed possible that this limited diversity is merely apparent and reflects only a failure to culture organisms, not their absence. The authors reported here phylogenetic characterization of many archaeal small subunit rRNA gene sequences obtained by polymerase chain reaction amplification of mixed population DNA extracted directly from sediment of a hot spring in Yellowstone National Park. This approach obviates the need for cultivation to identify organisms. The analyses document the existence not only of species belonging to well-characterized crenarchaeal genera or families but also of crenarchaeal species for which no close relatives have so far been found. The large number of distinct archaeal sequence types retrieved from this single hot spring was unexpected and demonstrates that Crenarchaeota is a much more diverse group than was previously suspected. The results have impact on concepts of the phylogenetic organization of Archaea.

  3. Study of the effects of gaseous environments on the hot corrosion of superalloy materials

    Science.gov (United States)

    Smeggil, J. G.; Bornstein, N. S.

    1980-01-01

    The effect of the gaseous corrodent NaCl on the high temperature oxidation and sodium sulfate induced hot corrosion behavior of alumina formers, chromia formers, and the superalloy B-1900 was examined. Isothermal experiments were conducted at 900 C and 1050 C in air in the presence and absence of NaCl vapors. Microstructural changes in oxide morphology and increased rates of oxidation were observed when NaCl(g) was present. It is hypothesized that the accelerated rates of oxidation are the result of removal of aluminum from the scale substrate interface and the weakening of the scale substrate bonds. The aluminum removed was redeposited on the surfaces in the form of alumina whiskers. For the superalloy B-1900, alumina whiskers are also formed, and the alloy oxidizes at catastrophic rates. In the case of Ni-25Cr alloy, NaCl vapors interact with the scale depleting it of chromium.

  4. Examination of fatigue development in elite soccer in a hot environment: a multi-experimental approach

    DEFF Research Database (Denmark)

    Mohr, Magni; Mujika, I.; Santisteban, J.

    2010-01-01

    The study examines fatigue in elite soccer played in hot conditions. High-profile soccer players (n=20) were studied during match play at ~31 °C. Repeated sprint and jump performances were assessed in rested state and after a game and activity profile was examined. Additionally, heart rate (HR......), blood lactate, muscle temperature and body mass changes were determined. Repeated sprint and jump performances were reduced (Pfatigue index in the repeated sprint test was 6.0±0.7% after the game compared with 1.7±1.0% at rest (P... half. Net fluid loss during the game was >2% of the body mass. Correlations were observed between net-fluid loss and repeated sprint test fatigue index after the game (r=0.73, P

  5. Conceptual design of the hot cell facility universal docking station at ITER

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, A., E-mail: alexis.dammann@iter.org [ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Benchikhoune, M.; Friconneau, J.P.; Ivanov, V. [ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Lemee, A. [SOGETI High Tech, 180 Rue Rene Descartes, 13851 Aix en Provence (France); Martins, J.P. [ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Tamassy, G. [SOGETI High Tech, 180 Rue Rene Descartes, 13851 Aix en Provence (France)

    2011-10-15

    Between main shutdowns of the ITER machine, in-vessel components and Iter Remote Maintenance System (IRMS) are transferred between the Tokamak complex and the Hot Cell Facility using different types of sealed casks. Transfer Casks have different physical interfaces with the Vacuum Vessel, which need to be the same at the docking stations of the HCF. It means that in-vessel components and IRMS are cleaned in the same cells, which is in fact not convenient. Furthermore, logistic studies showed that the use rate of the cells is very inhomogeneous. In order to have dedicated cell for decontamination of Remote Handling tools, in order to increase the operability efficiency and to removes the hot cell docking operation from the critical path, the concept of a universal docking station has been investigated. Based on an existing design, the work was focused on a review of requirements, the re-design and the integration within the HCF layout. The universal docking station has been proposed and is now integrated in HCF design.

  6. Ingestion of a cold temperature/menthol beverage increases outdoor exercise performance in a hot, humid environment.

    Science.gov (United States)

    Tran Trong, Than; Riera, Florence; Rinaldi, Kévin; Briki, Walid; Hue, Olivier

    2015-01-01

    A recent laboratory study demonstrated that the ingestion of a cold/menthol beverage improved exercise performance in a hot and humid environment during 20 km of all-out cycling. Therefore, the aim of this study was to determine whether the ingestion of cold water/ice-slurry with menthol would improve performance in hot and humid outdoor conditions. Ten trained males completed three trials of five blocks consisting of 4-km cycling and 1.5-km running. During warm-up, every block and recovery, the athletes drank 190 ml of aromatized (i.e., with 0.05 mL of menthol) beverage at three temperatures: Neutral (ambient temperature) (28.7°C±0. 5°C), Cold (3.1°C±0.6°C) or Ice-slurry (0.17°C±0.07°C). Trial time, core temperature (Tco), heart rate (HR), rate of perceived exertion (RPE), thermal sensation (TS) and thermal comfort (TC) were assessed. Ice-slurry/menthol increased performance by 6.2% and 3.3% compared with neutral water/menthol and cold water/menthol, respectively. No between-trial differences were noted for Tco, HR, RPE, TC and TS was lower with ice-slurry/menthol and cold water/menthol compared with neutral water/menthol. A low drink temperature combined with menthol lessens the performance decline in hot/humid outdoor conditions (i.e., compared with cold water alone). Performances were better with no difference in psycho-physiological stress (Tco, HR and RPE) between trials. The changes in perceptual parameters caused by absorbing a cold/menthol beverage reflect the psychological impact. The mechanism leading to these results seems to involve brain integration of signals from physiological and psychological sources.

  7. The effects of different air velocities on heat storage and body temperature in humans cycling in a hot, humid environment.

    Science.gov (United States)

    Saunders, A G; Dugas, J P; Tucker, R; Lambert, M I; Noakes, T D

    2005-03-01

    The purposes of this study were to determine (i) the effects of different facing air velocities on body temperature and heat storage during exercise in hot environmental conditions and (ii) the effects of ingesting fluids at two different rates on thermoregulation during exercise in hot conditions with higher air velocities. On five occasions nine subjects cycled for 2 h at 33.0 +/- 0.4 degrees C with a relative humidity of 59 +/- 3%. Air velocity was maintained at 0.2 km h(-1) (0 WS), 9.9 +/- 0.3 km h(-1) (10 WS), 33.3 +/-2.2 km h(-1) (100 WS) and 50.1 +/- 3.2 km h(-1) (150 WS) while subjects replaced 58.8 +/- 6.8% of sweat losses. In the fifth condition, air velocity was maintained at 33.7 +/- 2.2 km h(-1) and subjects replaced 80.0 +/- 6.8% of sweat losses (100.80 WS). Heat storage, body temperature and rating of perceived exertion were higher in 0 and 10 WS compared with all other conditions. There were no differences in any measured variable between 100 and 150 WS, or between 100 and 100.80 WS. Thus, the evaporative capacity of the environment is increased with higher air velocities, reducing heat storage and body temperature. At higher air velocities, a higher rate of fluid ingestion did not influence heat storage, body temperature or sweat rate. The finding of previous laboratory studies showing a beneficial effect of high rates of fluid ingestion on thermoregulation during exercise in hot, humid, windstill conditions cannot be extrapolated to out-of-doors exercise in which facing air velocities are seldom lower than the athlete's rate of forward progression.

  8. Ingestion of a cold temperature/menthol beverage increases outdoor exercise performance in a hot, humid environment.

    Directory of Open Access Journals (Sweden)

    Than Tran Trong

    Full Text Available A recent laboratory study demonstrated that the ingestion of a cold/menthol beverage improved exercise performance in a hot and humid environment during 20 km of all-out cycling. Therefore, the aim of this study was to determine whether the ingestion of cold water/ice-slurry with menthol would improve performance in hot and humid outdoor conditions.Ten trained males completed three trials of five blocks consisting of 4-km cycling and 1.5-km running. During warm-up, every block and recovery, the athletes drank 190 ml of aromatized (i.e., with 0.05 mL of menthol beverage at three temperatures: Neutral (ambient temperature (28.7°C±0. 5°C, Cold (3.1°C±0.6°C or Ice-slurry (0.17°C±0.07°C. Trial time, core temperature (Tco, heart rate (HR, rate of perceived exertion (RPE, thermal sensation (TS and thermal comfort (TC were assessed.Ice-slurry/menthol increased performance by 6.2% and 3.3% compared with neutral water/menthol and cold water/menthol, respectively. No between-trial differences were noted for Tco, HR, RPE, TC and TS was lower with ice-slurry/menthol and cold water/menthol compared with neutral water/menthol.A low drink temperature combined with menthol lessens the performance decline in hot/humid outdoor conditions (i.e., compared with cold water alone. Performances were better with no difference in psycho-physiological stress (Tco, HR and RPE between trials. The changes in perceptual parameters caused by absorbing a cold/menthol beverage reflect the psychological impact. The mechanism leading to these results seems to involve brain integration of signals from physiological and psychological sources.

  9. Applying outdoor environment to develop health, comfort, and energy saving in the office in hot-humid climate.

    Science.gov (United States)

    Chen, Rong; Sung, Wen-Pei; Chang, Hung-Chang; Chi, Yi-Rou

    2013-01-01

    A human life demand set to emerge in the future is the achievement of sustainability by maintaining a comfortable indoor environment without excessive reliance on energy-consuming air conditioners. The major research processes in this study are: (1) measuring indoor air quality and thermal comfort to evaluate the comfort of an indoor environment; (2) implementing questionnaire survey analysis to explore people's environmental self-perceptions and conducting a meta-analysis of the measurement results for air quality and physical aspects; and (3) constructing an indoor monitoring and management system. The experimental and analysis results of this research reveal that most of the office occupants preferred a cooler environment with a lower temperature. Additionally, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity and poor indoor air quality. Therefore, Variable Air Volume (VAV), two air intakes, and exhaust plant are installed to improve indoor environment. After improvement, a lower temperature (approximately 21.2-23.9°C) indirectly reduces humidity, thereby making the occupants comfortable. Increasing air velocity to 0.1~0.15 m/s, the carbon dioxide concentrations decrease below the requirement of the WHO. Ninety-five percent of the workers corresponded to the standard comfort zone after this improvement.

  10. Applying Outdoor Environment to Develop Health, Comfort, and Energy Saving in the Office in Hot-Humid Climate

    Science.gov (United States)

    Chen, Rong; Sung, Wen-Pei; Chang, Hung-Chang; Chi, Yi-Rou

    2013-01-01

    A human life demand set to emerge in the future is the achievement of sustainability by maintaining a comfortable indoor environment without excessive reliance on energy-consuming air conditioners. The major research processes in this study are: (1) measuring indoor air quality and thermal comfort to evaluate the comfort of an indoor environment; (2) implementing questionnaire survey analysis to explore people's environmental self-perceptions and conducting a meta-analysis of the measurement results for air quality and physical aspects; and (3) constructing an indoor monitoring and management system. The experimental and analysis results of this research reveal that most of the office occupants preferred a cooler environment with a lower temperature. Additionally, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity and poor indoor air quality. Therefore, Variable Air Volume (VAV), two air intakes, and exhaust plant are installed to improve indoor environment. After improvement, a lower temperature (approximately 21.2–23.9°C) indirectly reduces humidity, thereby making the occupants comfortable. Increasing air velocity to 0.1 ~ 0.15 m/s, the carbon dioxide concentrations decrease below the requirement of the WHO. Ninety-five percent of the workers corresponded to the standard comfort zone after this improvement. PMID:24311976

  11. Applying Outdoor Environment to Develop Health, Comfort, and Energy Saving in the Office in Hot-Humid Climate

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

    Full Text Available A human life demand set to emerge in the future is the achievement of sustainability by maintaining a comfortable indoor environment without excessive reliance on energy-consuming air conditioners. The major research processes in this study are: (1 measuring indoor air quality and thermal comfort to evaluate the comfort of an indoor environment; (2 implementing questionnaire survey analysis to explore people’s environmental self-perceptions and conducting a meta-analysis of the measurement results for air quality and physical aspects; and (3 constructing an indoor monitoring and management system. The experimental and analysis results of this research reveal that most of the office occupants preferred a cooler environment with a lower temperature. Additionally, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity and poor indoor air quality. Therefore, Variable Air Volume (VAV, two air intakes, and exhaust plant are installed to improve indoor environment. After improvement, a lower temperature (approximately 21.2–23.9°C indirectly reduces humidity, thereby making the occupants comfortable. Increasing air velocity to 0.1~0.15 m/s, the carbon dioxide concentrations decrease below the requirement of the WHO. Ninety-five percent of the workers corresponded to the standard comfort zone after this improvement.

  12. Structural Evolution of Molybdenum Carbides in Hot Aqueous Environments and Impact on Low-Temperature Hydroprocessing of Acetic Acid

    Directory of Open Access Journals (Sweden)

    Jae-Soon Choi

    2015-03-01

    Full Text Available We investigated the structural evolution of molybdenum carbides subjected to hot aqueous environments and their catalytic performance in low-temperature hydroprocessing of acetic acid. While bulk structures of Mo carbides were maintained after aging in hot liquid water, a portion of carbidic Mo sites were converted to oxidic sites. Water aging also induced changes to the non-carbidic carbon deposited during carbide synthesis and increased surface roughness, which in turn affected carbide pore volume and surface area. The extent of these structural changes was sensitive to the initial carbide structure and was lower under actual hydroprocessing conditions indicating the possibility of further improving the hydrothermal stability of Mo carbides by optimizing catalyst structure and operating conditions. Mo carbides were active in acetic acid conversion in the presence of liquid water, their activity being comparable to that of Ru/C. The results suggest that effective and inexpensive bio-oil hydroprocessing catalysts could be designed based on Mo carbides, although a more detailed understanding of the structure-performance relationships is needed, especially in upgrading of more complex reaction mixtures or real bio-oils.

  13. Thermal Influence of a Large Green Space on a Hot Urban Environment.

    Science.gov (United States)

    Sugawara, Hirofumi; Shimizu, Shogo; Takahashi, Hideo; Hagiwara, Shinsuke; Narita, Ken-Ichi; Mikami, Takehiko; Hirano, Tatsuki

    2016-01-01

    City-scale warming is becoming a serious problem in terms of human health. Urban green spaces are expected to act as a countermeasure for urban warming, and therefore better understanding of the micro-climate benefits of urban green is needed. This study quantified the thermal influence of a large green park in Tokyo, Japan on the surrounding urban area by collecting long-term measurements. Apparent variations in the temperature difference between the park and surrounding town were found at both the diurnal and seasonal scales. Advection by regional-scale wind and turbulent mixing transfers colder air from the park to urban areas in its vicinity. The extent of the park's thermal influence on the town was greater on the downwind side of the park (450 m) than on the upwind side (65 m). The extent was also greater in an area where the terrain slopes down toward the town. Even on calm nights, the extent of the thermal influence extended by the park breeze to an average of 200 m from the park boundary. The park breeze was characterized by its divergent flow in a horizontal plane, which was found to develop well in calm conditions late at night (regional scale wind green space tempered the hot summer nights on a city block scale. These findings can help urban planners in designing a heat-adapted city. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. The Thermochemical Degradation of Hot Section Materials for Gas Turbine Engines in Alternative-Fuel Combustion Environments

    Science.gov (United States)

    Montalbano, Timothy

    Gas turbine engines remain an integral part of providing the world's propulsion and power generation needs. The continued use of gas turbines requires increased temperature operation to reach higher efficiencies and the implementation of alternative fuels for a lower net-carbon footprint. This necessitates evaluation of the material coatings used to shield the hot section components of gas turbines in these new extreme environments in order to understand how material degradation mechanisms change. Recently, the US Navy has sought to reduce its use of fossil fuels by implementing a blended hydroprocessed renewable diesel (HRD) derived from algae in its fleet. To evaluate the material degradation in this alternative environment, metal alloys are exposed in a simulated combustion environment using this blended fuel or the traditional diesel-like fuel. Evaluation of the metal alloys showed the development of thick, porous scales with a large depletion of aluminum for the blend fuel test. A mechanism linking an increased solubility of the scale to the blend fuel test environment will be discussed. For power generation applications, Integrated Gasification Combined Cycle (IGCC) power plants can provide electricity with 45% efficiency and full carbon capture by using a synthetic gas (syngas) derived from coal, biomass, or another carbon feedstock. However, the combustion of syngas is known to cause high water vapor content levels in the exhaust stream with unknown material consequences. To evaluate the effect of increased humidity, air-plasma sprayed (APS), yttria-stabilized zirconia (YSZ) is thermally aged in an environment with and without humidity. An enhanced destabilization of the parent phase by humid aging is revealed by x-ray diffraction (XRD) and Raman spectroscopy. Microstructural analysis by transmission electron microscopy (TEM) and scanning-TEM (STEM) indicate an enhanced coarsening of the domain structure of the YSZ in the humid environment. The enhanced

  15. Hot-Wire Chemical Vapor Deposition Of Polycrystalline Silicon : From Gas Molecule To Solar Cell

    Science.gov (United States)

    van Veenendaal, P. A. T. T.

    2002-10-01

    Although the effort to investigate the use of renewable energy sources, such as wind and solar energy, has increased, their contribution to the total energy consumption remains insignificant. The conversion of solar energy into electricity through solar cells is one of the most promising techniques, but the use of these cells is limited by the high cost of electricity. The major contributions to these costs are the material and manufacturing costs. Over the past decades, the development of silicon based thin film solar cells has received much attention, because the fabrication costs are low. A promising material for use in thin film solar cells is polycrystalline silicon (poly-Si:H). A relatively new technique to deposit poly-Si:H is Hot-Wire Chemical Vapor Deposition (Hot-Wire CVD), in which the reactant gases are catalytically decomposed at the surface of a hot filament, mainly tungsten and tantalum. The main advantages of Hot-Wire CVD over PE-CVD are absence of ion bombardment, high deposition rate, low equipment cost and high gas utilization. This thesis deals with the full spectrum of deposition, characterization and application of poly-Si:H thin films, i.e. from gas molecule to solar cell. Studies on the decomposition of silane on the filament showed that the process is catalytic of nature and that silane is decomposed into Si and 4H. The dominant gas phase reaction is the reaction of Si and H with silane, resulting in SiH3, Si2H6, Si3H6 and H2SiSiH2. The film growth precursors are Si, SiH3 and Si2H4. Also, XPS results on used tantalum and tungsten filaments are discussed. The position dependent measurements show larger silicon contents at the ends of the tungsten filament, as compared to the middle, due to a lower filament temperature. This effect is insignificant for a tantalum filament. Deposition time dependent measurements show an increase in silicon content of the tungsten filament with time, while the silicon content on the tantalum filament saturates

  16. Hypertension is associated with greater heat exchange during exercise recovery in a hot environment

    Directory of Open Access Journals (Sweden)

    S. F. Fonseca

    2015-12-01

    Full Text Available Individuals with systemic arterial hypertension have a higher risk of heat-related complications. Thus, the aim of this study was to examine the thermoregulatory responses of hypertensive subjects during recovery from moderate-intensity exercise performed in the heat. A total of eight essential hypertensive (H and eight normotensive (N male subjects (age=46.5±1.3 and 45.6±1.4 years, body mass index=25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure=98.0±2.8 and 86.0±2.3 mmHg, respectively rested for 30 min, performed 1 h of treadmill exercise at 50% of maximal oxygen consumption, and rested for 1 h after exercise in an environmental chamber at 38°C and 60% relative humidity. Skin and core temperatures were measured to calculate heat exchange parameters. Mean arterial pressure was higher in the hypertensive than in the normotensive subjects throughout the experiment (P<0.05, unpaired t-test. The hypertensive subjects stored less heat (H=-24.23±3.99 W·m−2vs N=-13.63±2.24 W·m−2, P=0.03, unpaired t-test, experienced greater variations in body temperature (H=-0.62±0.05°C vsN=-0.35±0.12°C, P=0.03, unpaired t-test, and had more evaporated sweat (H=-106.1±4.59 W·m−2vs N=-91.15±3.24 W·m−2, P=0.01, unpaired t-test than the normotensive subjects during the period of recovery from exercise. In conclusion, essential hypertensive subjects showed greater sweat evaporation and increased heat dissipation and body cooling relative to normotensive subjects during recovery from moderate-intensity exercise performed in hot conditions.

  17. The Skyrme-TQRPA calculations of electron capture on hot nuclei in pre-supernova environment

    Energy Technology Data Exchange (ETDEWEB)

    Dzhioev, Alan A., E-mail: dzhioev@theor.jinr.ru; Vdovin, A. I., E-mail: vdovin@theor.jinr.ru [JINR, Bogoliubov Laboratory of Theoretical Physics (Russian Federation); Stoyanov, Ch., E-mail: stoyanov@inrne.bas.bg [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria)

    2016-11-15

    We combine the thermal QRPA approach with the Skyrme energy density functional theory (Skyrme–TQRPA) for modelling the process of electron capture on nuclei in supernova environment. For a sample nucleus, {sup 56}Fe, the Skyrme–TQRPA approach is applied to analyze thermal effects on the strength function of GT{sub +} transitions which dominate electron capture at E{sub e} ≤ 30 MeV. Several Skyrme interactions are used in order to verify the sensitivity of the obtained results to the Skyrme force parameters. Finite-temperature cross sections are calculated and the results are comparedwith those of the other model calculations.

  18. Strength and corrosion behavior of SiC - based ceramics in hot coal combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Breder, K.; Parten, R.J. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    As part of an effort to evaluate the use of advanced ceramics in a new generation of coal-fired power plants, four SiC-based ceramics have been exposed to corrosive coal slag in a laboratory furnace and two pilot scale combustors. Initial results indicate that the laboratory experiments are valuable additions to more expensive pilot plant experiments. The results show increased corrosive attack with increased temperature, and that only slight changes in temperature may significantly alter the degree of strength degradation due to corrosive attack. The present results are part of a larger experimental matrix evaluating the behavior of ceramics in the coal combustion environment.

  19. Investigation of the basic physics of high efficiency semiconductor hot carrier solar cell

    Science.gov (United States)

    Alfano, R. R.; Wang, W. B.; Mohaidat, J. M.; Cavicchia, M. A.; Raisky, O. Y.

    1995-01-01

    The main purpose of this research program is to investigate potential semiconductor materials and their multi-band-gap MQW (multiple quantum wells) structures for high efficiency solar cells for aerospace and commercial applications. The absorption and PL (photoluminescence) spectra, the carrier dynamics, and band structures have been investigated for semiconductors of InP, GaP, GaInP, and InGaAsP/InP MQW structures, and for semiconductors of GaAs and AlGaAs by previous measurements. The barrier potential design criteria for achieving maximum energy conversion efficiency, and the resonant tunneling time as a function of barrier width in high efficiency MQW solar cell structures have also been investigated in the first two years. Based on previous carrier dynamics measurements and the time-dependent short circuit current density calculations, an InAs/InGaAs - InGaAs/GaAs - GaAs/AlGaAs MQW solar cell structure with 15 bandgaps has been designed. The absorption and PL spectra in InGaAsP/InP bulk and MQW structures were measured at room temperature and 77 K with different pump wavelength and intensity, to search for resonant states that may affect the solar cell activities. Time-resolved IR absorption for InGaAsP/InP bulk and MQW structures has been measured by femtosecond visible-pump and IR-probe absorption spectroscopy. This, with the absorption and PL measurements, will be helpful to understand the basic physics and device performance in multi-bandgap InAs/InGaAs - InGaAs/InP - InP/InGaP MQW solar cells. In particular, the lifetime of the photoexcited hot electrons is an important parameter for the device operation of InGaAsP/InP MQW solar cells working in the resonant tunneling conditions. Lastly, time evolution of the hot electron relaxation in GaAs has been measured in the temperature range of 4 K through 288 K using femtosecond pump-IR-probe absorption technique. The temperature dependence of the hot electron relaxation time in the X valley has been measured.

  20. "His Native, Hot Country"1: Racial Science and Environment in Antebellum American Medical Thought.

    Science.gov (United States)

    Willoughby, Christopher D

    2017-07-01

    Relying on a close reading of more than 4,000 medicals student theses, this essay explores the evolving medical approaches to race and environment in the early national and antebellum United States and highlights the role that medical school pedagogy played in disseminating and elaborating racial theory. Specifically, it considers the influence of racial science on medical concepts of the relationship of bodies to climates. At their core, monogenesis-belief in a single, unified human race-and polygenesis-the belief that each race was created separately-were theories about the human body's connections to the natural world. As polygenesis became influential in Atlantic medical thought, physicians saw environmental treatments as a matter of matching bodies to their natural ecology. In the first decades of the nineteenth century, Atlantic physicians understood bodies and places as in constant states of flux. Through proper treatment, people and environments could suffer either degradation or improvement. Practitioners saw African Americans and whites as the same species with their differences being largely superficial and produced by climate. However, by the 1830s and 1840s medical students were learning that each race was inherently different and unalterable by time or temperature. In this paradigm, medical students articulated a vision of racial health rooted in organic relationships between bodies and climates. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Effectiveness of a newly designed construction uniform for heat strain attenuation in a hot and humid environment.

    Science.gov (United States)

    Yi, Wen; Chan, Albert P C; Wong, Francis K W; Wong, Del P

    2017-01-01

    This study aims to evaluate the effectiveness of a newly designed construction uniform in combating heat stress. Ten male volunteers performed treadmill running in a climatic chamber maintained at 34.5 °C temperature, 75% relative humidity, 0.3 m/s air velocity, and solar radiation of 450 W/m(2) that simulates typical summer working environment of construction sites in Hong Kong. The participants were tested while wearing two kinds of construction uniforms: a commonly worn uniform A, or a newly designed uniform B. It was found during exercise that Tc (38.34 ± 0.14 vs 38.45 ± 0.11 °C, p = 0.03), Tsk (36.01 ± 0.36 vs 36.27 ± 0.34 °C, p = 0.03), HR (162.7 ± 10.1 vs 172.5 ± 9.2 bpm, p construction uniform could reduce thermoregulatory and cardiovascular strain, and improve thermal comfort while exercising in a hot and humid environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Septic systems as hot-spots of pollutants in the environment: Fate and mass balance of micropollutants in septic drainfields.

    Science.gov (United States)

    Yang, Yun-Ya; Toor, Gurpal S; Wilson, P Chris; Williams, Clinton F

    2016-10-01

    Septic systems, a common type of onsite wastewater treatment systems, can be an important source of micropollutants in the environment. We investigated the fate and mass balance of 17 micropollutants, including wastewater markers, hormones, pharmaceuticals and personal care products (PPCPs) in the drainfield of a septic system. Drainfields were replicated in lysimeters (1.5m length, 0.9m width, 0.9m height) and managed similar to the field practice. In each lysimeter, a drip line dispersed 9L of septic tank effluent (STE) per day (equivalent to 32.29L/m(2) per day). Fourteen micropollutants in the STE and 12 in the leachate from drainfields were detected over eight months. Concentrations of most micropollutants in the leachate were low (85% of the added micropollutants except for sucralose were attenuated in the drainfield. We discovered that sorption was the key mechanism for retention of carbamazepine and partially for sulfamethoxazole, whereas microbial degradation likely attenuated acetaminophen in the drainfield. This data suggests that sorption and microbial degradation limited transport of micropollutants from the drainfields. However, the leaching of small amounts of micropollutants indicate that septic systems are hot-spots of micropollutants in the environment and a better understanding of micropollutants in septic systems is needed to protect groundwater quality. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Constant, cycling, hot and cold thermal environments: strong effects on mean viability but not on genetic estimates.

    Science.gov (United States)

    Ketola, T; Kellermann, V; Kristensen, T N; Loeschcke, V

    2012-06-01

    It has frequently been suggested that trait heritabilities are environmentally sensitive, and there are genetic trade-offs between tolerating different environments such as hot and cold or constant and fluctuating temperatures. Future climate predictions suggest an increase in both temperatures and their fluctuations. How species will respond to these changes is uncertain, particularly as there is a lack of studies which compare genetic performances in constant vs. fluctuating environments. In this study, we used a nested full-sib/half-sib breeding design to examine how the genetic variances and heritabilities of egg-to-adult viability differ at high and low temperatures with and without daily fluctuations in temperatures using Drosophila melanogaster as a model organism. Although egg-to-adult viability was clearly sensitive to developmental temperatures, heritabilities were not particularly sensitive to developmental temperatures. Moreover, we found that egg-to-adult viabilities at different developmental temperatures were positively correlated, suggesting a common genetic background for egg-to-adult viability at different temperatures. Finding both a uniform genetic background coupled with rather low heritabilities insensitive to temperatures, our results suggest evolutionary responses are unlikely to be limited by temperature effects on genetic parameters or negative genetic correlations, but by the direct effects of stressful temperatures on egg-to-adult viability accompanied with low heritabilities. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  4. Urine temperature as an index for the core temperature of industrial workers in hot or cold environments

    Science.gov (United States)

    Kawanami, Shoko; Horie, Seichi; Inoue, Jinro; Yamashita, Makiko

    2012-11-01

    Workers working in hot or cold environments are at risk for heat stroke and hypothermia. In Japan, 1718 people including 47 workers died of heat stroke in 2010 (Ministry of Health Labour and Welfare, Japan 2011). While the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation lists the abnormal core temperature of workers as a criterion for halting work, no method has been established for reliably measuring core temperatures at workplaces. ISO 9886 (Ergonomics-evaluation of thermal strain by physiological measurements. ISO copyright office, Geneva, pp 3-14; 2004) recognizes urine temperature as an index of core temperature only at normal temperature. In this study we ascertained whether or not urine temperature could serve as an index for core temperature at temperatures above and below the ISO range. We measured urine temperature of 31 subjects (29.8 ± 11.9 years) using a thermocouple sensor placed in the toilet bowl at ambient temperature settings of 40, 20, and 5˚C, and compared them with rectal temperature. At all ambient temperature settings, urine temperature correlated closely with rectal temperature exhibiting small mean bias. Urine temperature changed in a synchronized manner with rectal temperature at 40˚C. A Bland and Altman analysis showed that the limits of agreement (mean bias ± 2SD) between rectal and urine temperatures were -0.39 to +0.15˚C at 40˚C (95%CI -0.44 to +0.20˚C) and -0.79 to +0.29˚C at 5˚C (-0.89 to +0.39˚C). Hence, urine temperature as measured by the present method is a practical surrogate index for rectal temperature and represents a highly reliable biological monitoring index for assessing hot and cold stresses of workers at actual workplaces.

  5. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Andreasen, Søren Juhl; Berning, Torsten

    2016-01-01

    In order to better understand and more accurately measure the water balance in a proton exchange membrane fuel cell, our group has recently proposed to apply hot wire anemometry in the fuel cell's anode outlet. It was theoretically shown that the electrical signal obtained from the hot wire sensor...... can be directly converted into the fuel cell water balance. In this work an ex-situ experimental investigation is performed to examine the effect of the wire diameter and the outlet pipe diameter on the voltage signal. For a laboratory fuel cell where the mass flow rate the anode outlet is small......, it is found important to use a small output pipe diameter to obtain a sufficiently strong convection effect and hence clear voltage readings. Depending on the hot wire diameter and the inner pipe diameter, the resulting values for the exponent of the Reynolds number Re in the determination of the Nusselt...

  6. ENVIRONMENT PROTECTION THROUGH DETECTION OF HOT SPOTS USING THERMOGRAPHY IN COAL DEPOSITS BEFORE SELF IGNITION

    Directory of Open Access Journals (Sweden)

    Alina DINCĂ

    2009-12-01

    Full Text Available In this paper is presented a way to contribute to the environmental protection when it comes to coal which waits in big deposits to be burned for energy production. Because of certain parameters, in some places, the deposited coal could overheat and self ignite, thus loosing its caloric properties and even lead to fire. In this case the losses could be even higher, and the effect on the environment even worse. In order to prevent this self ignition to happen, an infrared camera can be mounted on a system, and the camera together with software which interprets the thermographic images, can alarm the personnel who is in charge with coal surveillance that the coal will ignite unless they take immediate measures. Also, there will be presented the limits we have found by now in the way of finalizing the application.

  7. Transcription-factor occupancy at HOT regions quantitatively predicts RNA polymerase recruitment in five human cell lines.

    KAUST Repository

    Foley, Joseph W

    2013-10-20

    BACKGROUND: High-occupancy target (HOT) regions are compact genome loci occupied by many different transcription factors (TFs). HOT regions were initially defined in invertebrate model organisms, and we here show that they are a ubiquitous feature of the human gene-regulation landscape. RESULTS: We identified HOT regions by a comprehensive analysis of ChIP-seq data from 96 DNA-associated proteins in 5 human cell lines. Most HOT regions co-localize with RNA polymerase II binding sites, but many are not near the promoters of annotated genes. At HOT promoters, TF occupancy is strongly predictive of transcription preinitiation complex recruitment and moderately predictive of initiating Pol II recruitment, but only weakly predictive of elongating Pol II and RNA transcript abundance. TF occupancy varies quantitatively within human HOT regions; we used this variation to discover novel associations between TFs. The sequence motif associated with any given TF\\'s direct DNA binding is somewhat predictive of its empirical occupancy, but a great deal of occupancy occurs at sites without the TF\\'s motif, implying indirect recruitment by another TF whose motif is present. CONCLUSIONS: Mammalian HOT regions are regulatory hubs that integrate the signals from diverse regulatory pathways to quantitatively tune the promoter for RNA polymerase II recruitment.

  8. Infrared characterization of hot spots in solar cells with high precision due to signal treatment processing

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, A.; Jouglar, J.; Mergui, M.; Jourlin, Y.; Bouille, A.; Vuillermoz, P.L.; Laugier, A. [Institute National des Sciences Appliquees, Laboratoire de Physique de la Matiere-UMR, Villeurbanne (France)

    1998-02-27

    In this paper we show how to improve greatly the resolution of IR thermography by using two different signal treatment methods: a static treatment and a dynamical treatment. This signal processing allows the study of 100 cm{sup 2} cells under low-forward or reverse-polarization conditions. Static and dynamical methods have both good resolutions: static has the advantage of being fast, and dynamical method does not need any reference image nor cooling system. We have shown that IR thermography is an interesting method for investigating shunts in solar cells. Thermal maps and I-V characterization of the hot spots show that the origin and the behavior of the shunts are varied and their influence on the efficiency is probably more important than what is usually thought

  9. Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC) - the Hot Start experience

    NARCIS (Netherlands)

    De Sousa, Paul A.; Steeg, Rachel; Wachter, Elisabeth; Bruce, Kevin; King, Jason; Hoeve, Marieke; Khadun, Shalinee; McConnachie, George; Holder, Julie; Kurtz, Andreas; Seltmann, Stefanie; Dewender, Johannes; Reimann, Sascha; Stacey, Glyn; O'Shea, Orla; Chapman, Charlotte; Healy, Lyn; Zimmermann, Heiko; Bolton, Bryan; Rawat, Trisha; Atkin, Isobel; Veiga, Anna; Kuebler, Bernd; Serano, Blanca Miranda; Saric, Tomo; Hescheler, Jürgen; Brüstle, Oliver; Peitz, Michael; Thiele, Cornelia; Geijsen, Niels; Holst, Bjørn; Clausen, Christian; Lako, Majlinda; Armstrong, Lyle; Gupta, Shailesh K.; Kvist, Alexander J.; Hicks, Ryan; Jonebring, Anna; Brolén, Gabriella; Ebneth, Andreas; Cabrera-Socorro, Alfredo; Foerch, Patrik; Geraerts, Martine; Stummann, Tina C.; Harmon, Shawn; George, Carol; Streeter, Ian; Clarke, Laura; Parkinson, Helen; Harrison, Peter W.; Faulconbridge, Adam; Cherubin, Luca; Burdett, Tony; Trigueros, Cesar; Patel, Minal J.; Lucas, Christa; Hardy, Barry; Predan, Rok; Dokler, Joh; Brajnik, Maja; Keminer, Oliver; Pless, Ole; Gribbon, Philip; Claussen, Carsten; Ringwald, Annette; Kreisel, Beate; Courtney, Aidan; Allsopp, Timothy E.

    2017-01-01

    A fast track “Hot Start” process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was

  10. Aandachtspunten voor een optimale voorbereiding : Inspanning in de warmte (Exercise in a hot environment: Points of special interest for an optimal preparation)

    NARCIS (Netherlands)

    Rietjens, G.J.W.M.; Arensbergen, W. van; Daanen, H.A.M.

    2004-01-01

    An elevated core temperature is one of the underlying factors responsible for a decrease of performance during exercise in a hot environment. Therefore, strategies that minimise the rise in core temperature during exercise in the heat are likely to be effective in enhancing exercise performance.

  11. Case series of mercury toxicity among children in a hot, closed environment.

    Science.gov (United States)

    Akyildiz, Basak Nur; Kondolot, Meda; Kurtoğlu, Selim; Konuşkan, Bahadir

    2012-03-01

    Mercury poisoning is much more prevalent in the general population than possibly many physicians realize. We present data on 26 pediatric cases with mercury intoxication from exposure to mercury by inhalation or skin contact as a result of a broken thermometer in a school laboratory. This is the largest pediatric series in Turkey. During a 3-month period, the study team observed the children for clinical symptoms, physical findings, and blood and mercury levels. Of all patients, 21 inhaled, 3 inhaled and touched the element, and 2 took the mercury home. Sixteen children were symptomatic at admission, although blood mercury levels in the symptomatic children were higher than those in asymptomatic children (P = 0.003). The urine mercury levels were not statistically different between the groups at the admission (P > 0.05). The exposure times were 3.5 and 2 hours for symptomatic and asymptomatic children, respectively (P = 0.003). The 2 children who took the mercury home had the highest blood mercury levels and the most prolonged exposure time. N-acetylcysteine and chelation treatments were started in 21 children who had symptoms of mercury intoxication and high mercury levels in their blood or urine. No adverse effects were observed during chelation therapy. Prompt removal of children from contaminated environments and proper decontamination or elimination of devices containing large amounts of mercury from schools are necessary to prevent serious complications caused by exposure to mercury.

  12. EFFECT OF THE VOLUME OF FLUID INGESTED ON URINE CONCENTRATING ABILITY DURING PROLONGED HEAVY EXERCISE IN A HOT ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Hidenori Otani

    2013-03-01

    Full Text Available This study examined the effect of the volume of fluid ingested on urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration. Seven healthy males performed 105 min of intermittent cycle exercise at 70% maximum oxygen uptake (32°C, 60% relative humidity while receiving no fluid ingestion (NF, voluntary fluid ingestion (VF, partial fluid ingestion equivalent to one-half of body mass loss (PF, and full fluid ingestion equivalent to body mass loss (FF. Fluid (5°C, 3.4% carbohydrate, 10.5 mmol·L-1 sodium was ingested just before commencing exercise and at 15, 33, 51, 69, and 87 min of exercise, and the total amount of fluid ingested in PF and FF was divided into six equal volumes. During exercise, body mass loss was 2.2 ± 0.2, 1.1 ± 0.5, 1.1 ± 0.2, and 0.1 ± 0.2% in NF, VF, PF, and FF, respectively, whereas total sweat loss was about 2% of body mass in each trial. Subjects in VF ingested 719 ± 240 ml of fluid during exercise; the volume of fluid ingested was 1.1 ± 0.4% of body mass. Creatinine clearance was significantly higher and free water clearance was significantly lower in FF than in NF during exercise. Urine flow rate during exercise decreased significantly in NF. There were significant decreases in creatinine and osmolar clearance and was a significant increase in free water clearance during exercise in NF and VF. Creatinine clearance decreased significantly and free water clearance increased significantly during exercise in PF. There was no statistical change in urinary indices of renal function during exercise in FF. The findings suggest that full fluid ingestion equivalent to body mass loss has attenuated the decline in urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration.

  13. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    SEIDEL CM; JAIN J; OWENS JW

    2009-02-23

    This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

  14. Can the PHS model (ISO7933) predict reasonable thermophysiological responses while wearing protective clothing in hot environments?

    Science.gov (United States)

    Wang, Faming; Kuklane, Kalev; Gao, Chuansi; Holmér, Ingvar

    2011-02-01

    In this paper, the prediction accuracy of the PHS (predicted heat strain) model on human physiological responses while wearing protective clothing ensembles was examined. Six human subjects (aged 29 ± 3 years) underwent three experimental trials in three different protective garments (clothing thermal insulation I(cl) ranges from 0.63 to 2.01 clo) in two hot environments (40 °C, relative humidities: 30% and 45%). The observed and predicted mean skin temperature, core body temperature and sweat rate were presented and statistically compared. A significant difference was found in the metabolic rate between FIRE (firefighting clothing) and HV (high visibility clothing) or MIL (military clothing) (p thermal insulations above 1.0 clo. The results showed that the PHS model generated unreliable predictions on body core temperature when human subjects wore thick protective clothing such as firefighting clothing (I(cl) > 1.0 clo). The predicted mean skin temperatures in three clothing ensembles HV, MIL and FIRE were also outside the expected limits. Thus, there is a need for further extension for the clothing insulation validation range of the PHS model. It is recommended that the PHS model should be amended and validated by individual algorithms, physical or physiological parameters, and further subject studies.

  15. Microbial and Metabolic Diversity of the Alkaline Hot Springs of Paoha Island: A Late Archean and Proterozoic Ocean Analogue Environment.

    Science.gov (United States)

    Foster, I. S.; Demirel, C.; Hyde, A.; Motamedi, S.; Frantz, C. M.; Stamps, B. W.; Nunn, H. S.; Oremland, R. S.; Rosen, M.; Miller, L. G.; Corsetti, F. A.; Spear, J. R.

    2016-12-01

    Paoha Island formed 450 years ago within Mono Lake, California, as a result of magmatic activity in the underlying Long Valley Caldera. Previous studies of Paoha Island hot springs focused on the presence of novel organisms adapted to high levels of arsenic (114-138 µM). However, the microbial community structure, relationship with Mono Lake, and preservation potential of these communities remains largely unexplored. Here, we present water chemistry, 16S and 18S rRNA gene sequences, and metagenomic data for spring water and biofilms sampled on a recently exposed mudflat along the shoreline of Paoha Island. Spring waters were hypoxic, alkaline, and saline, had variable temperature (39-70 °C near spring sources) and high concentrations of arsenic, sulfide and reduced organic compounds. Thermodynamic modeling based on spring water chemistry indicated that sulfide and methane oxidation were the most energetically favorable respiratory metabolisms. 16S rRNA gene sequencing revealed distinct communities in different biofilms: red biofilms were dominated by arsenite-oxidizing phototrophs within the Ectothiorhodospiraceae, while OTUs most closely related to the cyanobacterial genus Arthrospira were present in green biofilms, as well as a large proportion of sequences assigned to sulfur-oxidizing bacteria. Metagenomic analysis identified genes related to arsenic resistance, arsenic oxidation/reduction, sulfur oxidation and photosynthesis. Eukaryotic rRNA gene sequencing analyses revealed few detectable taxa in spring biofilms and waters compared to Mono Lake; springs receiving splash from the lake were dominated by the alga Picocystis. The co-occurrence of hypoxia, high pH, and close proximity of anoxygenic and oxygenic phototrophic mats makes this site a potential Archean/Proterozoic analogue environment, but suggests that similar environments if preserved in the rock record, may not preserve evidence for community dynamics or the existence of photosynthetic metabolisms.

  16. Spectroscopic study of a diffusion-bonded sapphire cell for hot metal vapors.

    Science.gov (United States)

    Sekiguchi, Naota; Sato, Takumi; Ishikawa, Kiyoshi; Hatakeyama, Atsushi

    2018-01-01

    Characteristics of a diffusion-bonded sapphire cell for optical experiments with hot metal vapors were investigated. The sapphire cell consisted of sapphire-crystal plates and a borosilicate-glass tube, which were bonded to each other by diffusion bonding without any binders or glues. The glass tube was attached to a vacuum manifold using the standard method applied in glass processing, filled with a small amount of Rb metal by chasing with a torch, and then sealed. The cell was baked at high temperatures, and optical experiments were then performed using rubidium atoms at room temperature. The sapphire cell was found to be vacuum tight, at least up to 350°C, and the sapphire walls remained clear over all temperatures. From the optical experiments, the generation of a background gas was indicated after baking at 200°C. The background gas pressure was low enough to avoid pressure broadening of absorption lines but high enough to cause velocity-changing collisions of Rb atoms. The generated gas pressure decreased at higher temperatures, probably due to chemical reactions.

  17. Hot-carrier solar cells using low-dimensional quantum structures

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Daiki; Kasamatsu, Naofumi; Harada, Yukihiro; Kita, Takashi [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-10-27

    We propose a high-conversion-efficiency solar cell (SC) utilizing the hot carrier (HC) population in an intermediate-band (IB) of a quantum dot superlattice (QDSL) structure. The bandgap of the host semiconductor in this device plays an important role as an energy-selective barrier for HCs in the QDSLs. According to theoretical calculation using the detailed balance model with an air mass 1.5 spectrum, the optimum IB energy is determined by a trade-off relation between the number of HCs with energy exceeding the conduction-band edge and the number of photons absorbed by the valence band−IB transition. Utilizing experimental data of HC temperature in InAs/GaAs QDSLs, the maximum conversion efficiency under maximum concentration (45 900 suns) has been demonstrated to increase by 12.6% as compared with that for a single-junction GaAs SC.

  18. HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Sell, D. A.; Baily, C. E.; Malewitz, T. J.; Medvedev, P. G.; Porter, D. L.; Hilton, B. A.

    2016-09-01

    A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium after the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.

  19. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Commercial Proton Exchange Membrane Fuel Cell Stack

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    2016-01-01

    and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel. Our research group...... is currently developing a novel technique to obtain an ad-hoc and real time electrical signal of the fuel cell water balance by employing hot wire anemometry. In this work, the hot wire sensor is placed in the anode outlet of a commercial air-cooled fuel cell stack by Ballard Power Systems, and the voltage......Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom backup units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce...

  20. Hot Cell Installation and Demonstration of the Severe Accident Test Station

    Energy Technology Data Exchange (ETDEWEB)

    Linton, Kory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Zachary M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yan, Yong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    A Severe Accident Test Station (SATS) capable of examining the oxidation kinetics and accident response of irradiated fuel and cladding materials for design basis accident (DBA) and beyond design basis accident (BDBA) scenarios has been successfully installed and demonstrated in the Irradiated Fuels Examination Laboratory (IFEL), a hot cell facility at Oak Ridge National Laboratory. The two test station modules provide various temperature profiles, steam, and the thermal shock conditions necessary for integral loss of coolant accident (LOCA) testing, defueled oxidation quench testing and high temperature BDBA testing. The installation of the SATS system restores the domestic capability to examine postulated and extended LOCA conditions on spent fuel and cladding and provides a platform for evaluation of advanced fuel and accident tolerant fuel (ATF) cladding concepts. This document reports on the successful in-cell demonstration testing of unirradiated Zircaloy-4. It also contains descriptions of the integral test facility capabilities, installation activities, and out-of-cell benchmark testing to calibrate and optimize the system.

  1. Tandem solar cells deposited using hot-wire chemical vapor deposition

    Science.gov (United States)

    van Veen, M. K.

    2003-05-01

    In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique are the high deposition rate, the low equipment costs, and the scalability. The main goal of this thesis is the optimization of the material properties of both hydrogenated amorphous silicon and microcrystalline silicon, so that these materials can be incorporated as the absorbing layers in tandem solar cells. Firstly, the influence of specific deposition parameters on the material quality of hydrogenated amorphous silicon was investigated. With the use of tantalum filaments, the deposition temperature could be decreased to moderate temperatures, while the (electronic) properties of the amorphous silicon were improved. However, at these low filament temperatures the silicide formation at the filaments was enhanced, resulting in a decrease in the deposition rate and a deterioration of the material quality over time. For extensive silicide formation, even epitaxial growth on crystalline wafers was observed. By preheating the filaments at elevated temperature before deposition, the influence of silicide formation could be minimized, which resulted in an improvement in the reproducibility of the material quality. Solar cells, in which the absorbing layer was made at moderate temperature, had high open-circuit voltages and high fill factors. The best n-i-p structured cell on plain stainless steel had an initial efficiency of 7.2 %. The incorporation of amorphous silicon in p-i-n structured cells with a textured front contact resulted in a higher short-circuit current density and a higher efficiency. Occasionally, many n-i-p structured cells showed shunting problems. The number of working cells was directly correlated to the age of the filaments. The presence of silicides on the

  2. Space Shuttle Main Engine Low Pressure Oxidizer Turbo-Pump Inducer Dynamic Environment Characterization through Water Model and Hot-Fire Testing

    Science.gov (United States)

    Arellano, Patrick; Patton, Marc; Schwartz, Alan; Stanton, David

    2006-01-01

    The Low Pressure Oxidizer Turbopump (LPOTP) inducer on the Block II configuration Space Shuttle Main Engine (SSME) experienced blade leading edge ripples during hot firing. This undesirable condition led to a minor redesign of the inducer blades. This resulted in the need to evaluate the performance and the dynamic environment of the redesign, relative to the current configuration, as part of the design acceptance process. Sub-scale water model tests of the two inducer configurations were performed, with emphasis on the dynamic environment due to cavitation induced vibrations. Water model tests were performed over a wide range of inlet flow coefficient and pressure conditions, representative of the scaled operating envelope of the Block II SSME, both in flight and in ground hot-fire tests, including all power levels. The water test hardware, facility set-up, type and placement of instrumentation, the scope of the test program, specific test objectives, data evaluation process and water test results that characterize and compare the two SSME LPOTP inducers are discussed. In addition, dynamic characteristics of the two water models were compared to hot fire data from specially instrumented ground tests. In general, good agreement between the water model and hot fire data was found, which confirms the value of water model testing for dynamic characterization of rocket engine turbomachinery.

  3. Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review

    Directory of Open Access Journals (Sweden)

    Keyne Charlot

    2017-06-01

    Full Text Available Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY, glucagon-like peptide 1 (GLP-1, and pancreatic polypeptide (PP levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected.

  4. Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review

    Science.gov (United States)

    Charlot, Keyne; Faure, Cécile; Antoine-Jonville, Sophie

    2017-01-01

    Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI) and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY), glucagon-like peptide 1 (GLP-1), and pancreatic polypeptide (PP) levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat) and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected. PMID:28604591

  5. Importance of Electrode Hot-Pressing Conditions for the Catalyst Performance of Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Larsen, Mikkel Juul

    2015-01-01

    The catalyst performance in a proton exchange membrane fuel cell (PEMFC) depends on not only the choice of materials, but also on the electrode structure and in particular on the interface between the components. In this work, we demonstrate that the hot-pressing conditions used during electrode...

  6. Hot-compress: A new postdeposition treatment for ZnO-based flexible dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haque Choudhury, Mohammad Shamimul, E-mail: shamimul129@gmail.com [Department of Frontier Material, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan); Department of Electrical and Electronic Engineering, International Islamic University Chittagong, b154/a, College Road, Chittagong 4203 (Bangladesh); Kishi, Naoki; Soga, Tetsuo [Department of Frontier Material, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan)

    2016-08-15

    Highlights: • A new postdeposition treatment named hot-compress is introduced. • Hot-compression gives homogeneous compact layer ZnO photoanode. • I-V and EIS analysis data confirms the efficacy of this method. • Charge transport resistance was reduced by the application of hot-compression. - Abstract: This article introduces a new postdeposition treatment named hot-compress for flexible zinc oxide–base dye-sensitized solar cells. This postdeposition treatment includes the application of compression pressure at an elevated temperature. The optimum compression pressure of 130 Ma at an optimum compression temperature of 70 °C heating gives better photovoltaic performance compared to the conventional cells. The aptness of this method was confirmed by investigating scanning electron microscopy image, X-ray diffraction, current-voltage and electrochemical impedance spectroscopy analysis of the prepared cells. Proper heating during compression lowers the charge transport resistance, longer the electron lifetime of the device. As a result, the overall power conversion efficiency of the device was improved about 45% compared to the conventional room temperature compressed cell.

  7. A new general and rapid method for investigating hot corrosion: preliminary tests on electrodes for molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, T.R. [Dept. of Chemistry, Univ. of Leeds, Leeds (United Kingdom); Volkovich, V.A. [Dept. of Rare Metals, Ural State Technical Univ. - UPI, Ekaterinburg (Russian Federation)

    2004-07-01

    With the increase and improvement in corrosion resistant alloys, coatings and surface treatments, the ability to test and predict their long-term behaviour to oxidation under hot corrosion conditions, within a reasonable time period, becomes diminished. Peroxide and superoxide ions are the most active oxidisers and we have established a means for generating them in significant concentrations in molten carbonates. This thus has the potential for enabling accelerated hot corrosion studies and we here describe the technique and report preliminary studies on the nickel and nickel oxide electrodes used in molten carbonate fuel cells. Further applications are expected to follow. (orig.)

  8. Peran Kecepatan Angin Terhadap Peningkatan Kenyamanan Termis Manusia Di Lingkungan Beriklim Tropis Lembab (the Role of Wind Velocity on Increasing Human Thermal Comfort in Hot and Humid Environment)

    OpenAIRE

    Sangkertadi, Sangkertadi

    2006-01-01

    The most important factors which influence the condition of thermal comfort are clothing, temperature, humidity, air velocity, and types of activities. In hot and humid climate, feeling of comfort are associated with sweating. Air velocity can cool building occupants by increasing convective and evaporative heat loses. This paper intends to explore the techniques for evaluating of thermal comfort especially with introduction of PMV and DISC scales for the tropical humid environment. The study...

  9. Radioprotective Effects of Sulfurcontaining Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells

    Directory of Open Access Journals (Sweden)

    Heidari A. H.

    2017-12-01

    Full Text Available Background: We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. Objective: The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. Method: Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed. Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy. 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. Results: A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/ PCEs+NCEs (P < 0.001 in sulfur-containing hot spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. Conclusion: The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.

  10. Closure of the concrete supercontainer in hot cell under thermal load

    Energy Technology Data Exchange (ETDEWEB)

    Craeye, Bart, E-mail: bart.craeye@artesis.b [Artesis Univerity College of Antwerp, Applied Engineering and Technology, Antwerp (Belgium); De Schutter, Geert [Magnel Laboratory for Concrete Research, Ghent University, Technologiepark-Zwijnaarde 904, 9052 Ghent (Belgium); Wacquier, William; Van Humbeeck, Hughes [ONDRAF/NIRAS, Belgian Agency for Radioactive Waste and Enriched Fissile Materials (Belgium); Van Cotthem, Alain [Tractebel Development Engineering, Consulting Company (Belgium); Areias, Lou [SCK.CEN, Belgian Nuclear Research Center (Belgium)

    2011-05-15

    Research highlights: We model the behaviour of the supercontainer for the disposal of high-level waste and spent fuel assemblies during fabrication at ground surface. We study the early-age cracking behaviour of the buffer and evaluate the crack creating mechanisms. In case accurate measures are taken, cracking of the buffer can be avoided. - Abstract: For the final disposal of long-lived, heat-emitting vitrified high-level waste (HLW) in a clayey host rock, an intensive study is conducted to investigate the early-age behaviour of concrete supercontainers. Self-compacting concrete (SCC) is taken as the reference concrete type as it facilitates the casting process in combination with an improved homogeneity compared to the traditional concrete compositions. A laboratory characterization program is conducted to obtain the relevant thermal, mechanical and maturity-related properties of the SCC. These obtained data are implemented into the material database of the finite element tool HEAT to study the behaviour of the concrete layers during the different construction stages of the supercontainer: (i) Stage 1: Fabrication of the concrete buffer inside a stainless steel envelope. No early-age cracking is expected in case accurate measures are taken to reduce the thermal gradient between the outer surface and the middle of the buffer, e.g. by providing insulation and excluding wind. (ii) Stages 2-4: Emplacement of the carbon steel overpack containing the HLW canisters, filling the remaining annular gap with cementitious filler and closure by fitting the lid under thermal load. The construction stages (2-4) for the closure of the supercontainer are executed in hot cell. In this study, the crack creating mechanism and the behaviour of the concrete supercontainer during these construction stages in hot cell are investigated. In case precautionary measures are taken, such as reducing the coefficient of thermal expansion (CTE) of the overpack, prolonging the preceding cooling

  11. Tandem solar cells deposited using hot-wire chemical vapor deposition

    NARCIS (Netherlands)

    Veen, M.K. van

    2003-01-01

    In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique

  12. Micropattern array with gradient size (µPAGS) plastic surfaces fabricated by PDMS (polydimethylsiloxane) mold-based hot embossing technique for investigation of cell-surface interaction.

    Science.gov (United States)

    Choi, Min Jin; Park, Ju Young; Cha, Kyoung Je; Rhie, Jong-Won; Cho, Dong-Woo; Kim, Dong Sung

    2012-12-01

    Recently, it was found that the variations of physical environment significantly affect cell behaviors including cell proliferation, migration and differentiation. Through a plastic surface with controlled mechanical properties such as stiffness, one can change the orientation and migration of cells in a particular direction, thereby determining cell behaviors. In this study, we demonstrate a polydimethylsiloxane (PDMS) mold-based hot embossing technique for rapid, simple and low-cost replication of polystyrene (PS) surfaces having micropatterns. The PDMS mold was fabricated by UV-photolithography followed by PDMS casting; the elastomeric properties of PDMS enabled us to obtain conformal contact of the PDMS mold to a PS surface and to create high transcription quality of micropatterns on the PS surface. Two different types of circular micropillar and microwell arrays were successfully replicated on the PS surfaces based on the suggested technique. The micropatterns were designed to have various diameters (2-150 µm), spacings (2-160 µm) and heights (1.4, 2.4, 8.2 and 14.9 µm), so as to generate the gradient of physical properties on the surface. Experimental parametric studies indicated that (1) the embossing temperature became a critical processing parameter as the aspect ratio of micropattern increased and (2) the PDMS mold-based hot embossing could successfully replicate micropatterns, even having an aspect ratio of 2.7 for micropattern diameter of 6 µm, with an optimal processing condition (embossing pressure and temperature of 0.4 MPa and 130 °C, respectively) in this study. We carried out cell experiments with adipose-derived stem cells on the replicated PS surface with the height of 1.4 µm to investigate cellular behaviors in response to the micropattern array with gradient size. Cellular experiment results showed that the micropillar-arrayed surface improved cell proliferation as compared with the microwell-arrayed surface. We could also estimate the

  13. Effect of thermal changes of mouth environment by hot and cold drinks on the temperature of implants

    Directory of Open Access Journals (Sweden)

    Mahmod Kazemi

    2013-10-01

    Full Text Available   Background and Aims: Thermal changes in the oral cavity can be transferred to the implants placed in bone and affect the prognosis of the treatments. Furthermore, some investigators proposed improvement of habitual consumption of hot or cold beverages. The aim of the present study was to measure the effect of temperature changes in the oral cavity following consumption of hot and cold drinks on the temperature of implant.   Materials and Methods: In this clinical trial, 3 eligible patients were selected. Two months after implant insertion, temperature of the implants was measured following the drinking of hot and cold beverages using a sensor connected to a thermometer. The thermal changes of the implants through the different time intervals were analyzed using Friedman non-parametric test.   Results: The implant temperatures were significantly increased in the time following drinking of the hot beverages (P=0.009. Furthermore, the implant temperature were statistically decreased in the time after drinking cold beverage (P=0.004. When drinking hot beverages, the maximum and minimum temperatures were 41.57 0 C and 36.77 0 C, respectively. The maximum and minimum temperatures of the implants were also 34.13 0 C and 26.83 0 C , respectively, when drinking cold beverages.   Conclusion: It seems that the temperatures noted in the implants in the current study cannot weaken the prognosis of implant restorations; however, habitual consumption of hot and cold beverages can lead to debilitating implant prognosis and therefore, should be given the necessary warnings to patients.

  14. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yasuhiko, E-mail: takeda@mosk.tytlabs.co.jp; Sugimoto, Noriaki [Toyota Central Research and Development Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan); Ichiki, Akihisa [Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Kusano, Yuya [Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Toyota Motor Corp., 1200 Mishuku, Susono, Shizuoka 410-1193 (Japan); Motohiro, Tomoyoshi [Toyota Central Research and Development Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan); Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2015-09-28

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  15. Development of Modified Ring Tensile Test Technique for Fuel Cladding in Hot Cell (II)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Sik; Ahn, S. B.; Oh, W. H.; Yoo, B. O.; Choo, Y. S

    2005-12-15

    The modified ring tensile test technique was proposed in order to evaluate mechanical properties of fuel cladding under hoop loading condition in hot cell. The hoop loading grip for the modified ring tensile test is designed such that a constant specimen curvature is maintained during deformation, and the gage section of ring specimen is located at the top of the half-cylinder({phi}8.08 mm). The interface between the outer surface of the half-cylinder and the inner surface of the ring specimen was lubricated by graphite lubricant(Molykote P37) in order to minimize the friction between this contact surface. The ring specimen design for ring tensile test is conducted to limit deformation within the gauge section and to maximize uniformity of strain distribution. The dimensions of the ring specimen are 5 mm in ring width, 3 mm in gage length, 2 mm in width of the gage section and 1 mm in radius of the shoulder part. The specially designed precision grinding machine was developed to machine the gage section at the ring segment with 5 mm in length, and the optimum machining conditions are determined. From the comparisons between the test results in this study and the other researcher's test results, we ensure that the proposed ring tensile test technique is suitable to evaluate the mechanical properties of fuel cladding in hoop direction quantitatively.

  16. An Applied Study on the Decontamination and Decommissioning of Hot Cell Facilities in the United States and Comparison with the Studsvik Facility for Solid and Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Geoff; Rusch, Chris [NAC International, Atlanta, GA (United States)

    2006-07-15

    have a tendency to assume optimal circumstances and tend not to account for potential changes of circumstances in, for example, the regulatory environment and requirements. It therefore may be prudent to review in general the cost allowances for efforts in this category. The estimate for decontamination and dismantling overall appears to be reasonable. Areas where additional costs could occur (e.g. hot cell concrete) have been identified in this report. Additional cost for waste disposal would be the main consequence if such contamination were found. One of the big differences between the plan and the outcome at HCF was the amount of dismantling waste that had to be disposed of as active waste. The HM facility appears to be in much better radiological condition overall than HCF but it cannot be discounted that surprises are found and/or regulatory requirements change regarding the dumping of waste. If an engineered solution (concrete cutting) were required to dismantle the hot cell, a substantial additional cost could apply. Following on from the above comments, the HM estimate does not include any significant allowance for characterisation/radiological mapping of the facility prior to designing and planning the decontamination and dismantling work. The development of an accurate picture before proceeding with the work normally is a prudent and beneficial step to take. An additional estimated cost of up to MSEK 3 could apply for such an exercise. The treatment of uncertainty in developing the HM cost estimate seems to have followed the pattern of other cost estimates analysed by NAC, whereby a round percentage number has been added to certain base estimates. As recommended in reference 4, a more focused approach based on identifying the main potential cost sensitivities and then dealing with them in a more individual manner would be preferable.

  17. Immunosuppressive Environment in Basal Cell Carcinoma

    DEFF Research Database (Denmark)

    Omland, Silje Haukali; Nielsen, Patricia S; Gjerdrum, Lise M R

    2016-01-01

    Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed...

  18. Hot Wire CVD for thin film triple junction cells and for ultrafast deposition of the SiN passivation layer on polycrystalline Si solar cells

    NARCIS (Netherlands)

    Schropp, R.E.I.; Franken, R.H.; Goldbach, H.D.; Houweling, Z.S.; Li, H. B. T.; Rath, J.K.; Schuttauf, J.A.; Stolk, R.L.; Verlaan, V.; van der Werf, C.H.M.

    2008-01-01

    We present recent progress on hot-wire deposited thin film solar cells and applications of silicon nitride. The cell efficiency reached for μc-Si:H n–i–p solar cells on textured Ag/ZnO presently is 8.5%, in line with the state-of-the-art level for μc-Si:H n–i–p's for any method of deposition. Such

  19. Exosomes surf on filopodia to enter cells at endocytic hot spots, traffic within endosomes, and are targeted to the ER.

    Science.gov (United States)

    Heusermann, Wolf; Hean, Justin; Trojer, Dominic; Steib, Emmanuelle; von Bueren, Stefan; Graff-Meyer, Alexandra; Genoud, Christel; Martin, Katrin; Pizzato, Nicolas; Voshol, Johannes; Morrissey, David V; Andaloussi, Samir E L; Wood, Matthew J; Meisner-Kober, Nicole C

    2016-04-25

    Exosomes are nanovesicles released by virtually all cells, which act as intercellular messengers by transfer of protein, lipid, and RNA cargo. Their quantitative efficiency, routes of cell uptake, and subcellular fate within recipient cells remain elusive. We quantitatively characterize exosome cell uptake, which saturates with dose and time and reaches near 100% transduction efficiency at picomolar concentrations. Highly reminiscent of pathogenic bacteria and viruses, exosomes are recruited as single vesicles to the cell body by surfing on filopodia as well as filopodia grabbing and pulling motions to reach endocytic hot spots at the filopodial base. After internalization, exosomes shuttle within endocytic vesicles to scan the endoplasmic reticulum before being sorted into the lysosome as their final intracellular destination. Our data quantify and explain the efficiency of exosome internalization by recipient cells, establish a new parallel between exosome and virus host cell interaction, and suggest unanticipated routes of subcellular cargo delivery. © 2016 Heusermann et al.

  20. Advanced Manufacturing Technologies (AMT): Additive Manufactured Hot Fire Planning and Testing in GRC Cell 32 Project

    Data.gov (United States)

    National Aeronautics and Space Administration — GRC and AR have identified the following roles and responsibilities necessary to accomplish the hot fire objective of this task.  AR will be responsible for...

  1. Modeling and characterization of double resonant tunneling diodes for application as energy selective contacts in hot carrier solar cells

    Science.gov (United States)

    Jehl, Zacharie; Suchet, Daniel; Julian, Anatole; Bernard, Cyril; Miyashita, Naoya; Gibelli, Francois; Okada, Yoshitaka; Guillemolles, Jean-Francois

    2017-02-01

    Double resonant tunneling barriers are considered for an application as energy selective contacts in hot carrier solar cells. Experimental symmetric and asymmetric double resonant tunneling barriers are realized by molecular beam epitaxy and characterized by temperature dependent current-voltage measurements. The negative differential resistance signal is enhanced for asymmetric heterostructures, and remains unchanged between low- and room-temperatures. Within Tsu-Esaki description of the tunnel current, this observation can be explained by the voltage dependence of the tunnel transmission amplitude, which presents a resonance under finite bias for asymmetric structures. This effect is notably discussed with respect to series resistance. Different parameters related to the electronic transmission of the structure and the influence of these parameters on the current voltage characteristic are investigated, bringing insights on critical processes to optimize in double resonant tunneling barriers applied to hot carrier solar cells.

  2. Crane system with remote actuation mechanism for use in argon compartment in ACPF hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Kwang, E-mail: leejk@kaeri.re.kr; Park, Byung-Suk; Yu, Seung-Nam; Kim, Kiho; Cho, Il-je

    2016-10-15

    Highlights: • Novel crane system with a remote actuation mechanism for feasible maintenance under limited space conditions is proposed. • Linear drive systems are implemented for accurate positioning. • Modular design concepts for easy maintenance are introduced. • The motion controller and the off-the-shelf camera controller are integrated to provide more efficient operation. - Abstract: The Advanced spent fuel Conditioning Process Facility (ACPF) at the Korea Atomic Energy Research Institute (KAERI) has recently been successfully renovated. One of the highlights of this renovation project was the installation of a small argon compartment within the atmospheric hot cell of the facility. Even though a crane system was considered necessary for the remote handling of the processing equipment inside the argon compartment, no suitable commercial cranes were available. This was because a limited amount of space had been reserved for the installation of the crane. Moreover, a master-slave manipulator (MSM), the only available means of maintenance of the crane, was unable to reach it in the limited workspace. To address the difficulties in the design of this crane, in this study, a remote actuation mechanism is devised where the mechanical and electrical parts of the crane system are separated, positioned far away from each other, and connected through power transmission shafts. This approach has two main advantages. First, the electrical parts can be placed inside the workspace of the MSM, hence allowing for remote maintenance. Second, the space occupied by the electrical parts and their cables, which are separate from the crane in the proposed design, can be considered and exploited in designing the mechanical parts of the crane. This enables the construction of a short, special crane in order to maximize the workspace. Furthermore, the mechanical parts for the MSM located outside the workspace are designed to possess a high safety margin to ensure durability

  3. Hot Fuel Examination Facility (HFEF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hot Fuel Examination Facility (HFEF) is one of the largest hot cells dedicated to radioactive materials research at Idaho National Laboratory (INL). The nation's...

  4. Ceramide-Enriched Membrane Domains in Red Blood Cells and the Mechanism ofSphingomyelinase-Induced Hot-Cold Hemolysis

    DEFF Research Database (Denmark)

    Montes, Ruth; Lopez, David; Sot, Jesus

    2008-01-01

    Hot-cold hemolysis is the phenomenon whereby red blood cells, preincubated at 37 °C in the presence of certain agents, undergo rapid hemolysis when transferred to 4 °C. The mechanism of this phenomenon is not understood. PlcHR2, a phospholipase C/sphingomyelinase from Pseudomonas aeruginosa......) but also in goat erythrocytes, which lack PC. However, in horse erythrocytes, with a large proportion of PC and almost no SM, hot-cold hemolysis induced by PlcHR2 is not observed. Fluorescence microscopy observations confirm the formation of ceramide-enriched domains as a result of PlcHR2 activity. After......-cold hemolysis. Differential scanning calorimetry of erytrocyte membranes treated with PlcHR2 demonstrates the presence of ceramide-rich domains that are rigid at 4 °C but fluid at 37 °C. Ceramidase treatment causes the disapperance of the calorimetric signal assigned to ceramide-rich domains. Finally...

  5. NASA's Bioreactor: Growing Cells in a Microgravity Environment. Educational Brief.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    This brief discusses growing cells in a microgravity environment for grades 9-12. Students are provided with plans for building a classroom bioreactor that can then be used with the included activity on seed growth in a microgravity environment. Additional experimental ideas are also suggested along with a history and background on microgravity…

  6. Slip-cast and hot-solution infiltrated porous yttria stabilized zirconia (YSZ) supported tubular fuel cells

    Science.gov (United States)

    Hanifi, Amir Reza; Paulson, Scott; Torabi, Alireza; Shinbine, Alyssa; Tucker, Michael C.; Birss, Viola; Etsell, Thomas H.; Sarkar, Partha

    2014-11-01

    Hot solution infiltration was investigated as a flexible and rapid method to incorporate anode and cathode components into fully sintered, porous ceramic tubular templates for use as solid oxide fuel cells (SOFC). Composed of either a porous 8 mol% yttria-stabilized zirconia (YSZ) or 5 wt% NiO-YSZ support structure, a thin Ni-YSZ anode functional layer and an outer ca. 10 μm dense YSZ electrolyte, closed end tubes were first hot solution (ca. 100 °C) infiltrated on the inside with NiO-SDC (Sm0.2Ce0.8O1.9) to serve as the anode. Cathodes were either LSM (nominally La0.8Sr0.2MnO3+δ) infiltrated into a thin porous YSZ layer on the outer electrolyte surface, or an LSCF-GDC composite (Gd0.1Ce0.9O1.95-La0.6Sr0.4Co0.2Fe0.8O3-δ) on a thin GDC buffer layer. Although hot solution infiltration of the Ni, Ce and Sm salts into the anode support structure did not result in complete penetration (with the Ni contents in the tube wall ranging between 4 and 10 vol.%), well-sealed full cells produced power densities as high as 275, 196 and 153 mW cm-2 at 800, 750 and 700 °C, respectively. Hot solution infiltration of active SOFC electrode materials is thus shown to be a very flexible approach for the evaluation of their performance.

  7. Employing Hot Wire Anemometry to Directly Measure the Water Balance in a Proton Exchange membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Hussain, Nabeel; Berning, Torsten

    2015-01-01

    Water management in proton exchange membrane fuel cells (PEMFC’s) remains a critical problem for their durability, cost, and performance. Because the anode side of this fuel cell has the tendency to become dehydrated, measuring the water balance can be an important diagnosis tool during fuel cell...... operation. The water balance indicates how much of the product water leaves at the anode side versus the cathode side. Previous methods of determining the fuel cell water balance often relied on condensing the water in the exhaust gas streams and weighing the accumulated mass which is a time consuming...... process that has limited accuracy. Currently, our group is developing a novel method to accurately determine the water balance in a PEMFC in real time by employing hot-wire anemometry. The amount of heat transferred from the wire to the anode exhaust stream can be translated into a voltage signal which...

  8. Submerged RadBall® deployments in Hanford Site hot cells containing 137CsCl capsules.

    Science.gov (United States)

    Farfán, Eduardo B; Coleman, J Rusty; Stanley, Steven; Adamovics, John; Oldham, Mark; Thomas, Andrew

    2012-07-01

    The overall objective of this study was to demonstrate that a new technology, known as RadBall®, could locate submerged radiological hazards. RadBall® is a novel, passive, radiation detection device that provides a 3-D visualization of radiation from areas where measurements have not been previously possible due to lack of access or extremely high radiation doses. This technology has been under development during recent years, and all of its previous tests have included dry deployments. This study involved, for the first time, underwater RadBall® deployments in hot cells containing 137CsCl capsules at the U.S. Department of Energy's Hanford Site. RadBall® can be used to characterize a contaminated room, hot cell, or glovebox by providing the locations of the radiation sources and hazards, identifying the radionuclides present within the cell, and determining the radiation sources' strength (e.g., intensities or dose rates). These parameters have been previously determined for dry deployments; however, only the location of radiation sources and hazards can be determined for an underwater RadBall® deployment. The results from this study include 3-D images representing the location of the radiation sources within the Hanford Site cells. Due to RadBall®'s unique deployability and non-electrical nature, this technology shows significant promise for future characterization of radiation hazards prior to and during the decommissioning of contaminated nuclear facilities.

  9. Cell survival in a simulated Mars environment

    Science.gov (United States)

    Todd, Paul; Kurk, Michael Andy; Boland, Eugene; Thomas, David

    2016-07-01

    The most ancient life forms on earth date back comfortably to the time when liquid water was believed to be abundant on Mars. These ancient life forms include cyanobacteria, contemporary autotrophic earth organisms believed to have descended from ancestors present as long as 3.5 billion years ago. Contemporary cyanobacteria have adapted to the earth environment's harshest conditions (long-term drying, high and low temperature), and, being autotrophic, they are among the most likely life forms to withstand space travel and the Mars environment. However, it is unlikely that humans would unwittingly contaminate a planetary spacecraft with these microbes. One the other hand, heterotrophic microbes that co-habit with humans are more likely spacecraft contaminants, as history attests. Indeed, soil samples from the Atacama desert have yielded colony-forming organisms resembling enteric bacteria. There is a need to understand the survivability of cyanobacteria (likely survivors, unlikely contaminants) and heterotrophic eubacteria (unlikely survivors, likely contaminants) under simulated planetary conditions. A 35-day test was performed in a commercial planetary simulation system (Techshot, Inc., Greenville, IN) in which the minimum night-time temperature was -80 C, the maximum daytime temperature was +26 C, the simulated day-night light cycle in earth hours was 12-on and 12-off, and the total pressure of the pure CO _{2} atmosphere was maintained below 11 mbar. Any water present was allowed to equilibrate with the changing temperature and pressure. The gas phase was sampled into a CR1-A low-pressure hygrometer (Buck Technologies, Boulder, CO), and dew/frost point was measured once every hour and recorded on a data logger, along with the varying temperature in the chamber, from which the partial pressure of water was calculated. According to measurements there was no liquid water present throughout the test except during the initial pump-down period when aqueous specimens

  10. Cells in fluidic environments are sensitive to flow frequency.

    Science.gov (United States)

    Balcells, Mercedes; Fernández Suárez, Marta; Vázquez, María; Edelman, Elazer R

    2005-07-01

    Virtually all cells accommodate to their mechanical environment. In particular, cells subject to flow respond to rapid changes in fluid shear stress (SS), cyclic stretch (CS), and pressure. Recent studies have focused on the effect of pulsatility on cellular behavior. Since cells of many different tissue beds are constantly exposed to fluid flows over a narrow range of frequencies, we hypothesized that an intrinsic flow frequency that is optimal for determining cell phenotype exists. We report here that cells from various tissue beds (bovine aortic endothelial cells (BAEC), rat small intestine epithelial cells (RSIEC), and rat lung epithelial cells (RLEC)) proliferate maximally when cultured in a perfusion bioreactor under pulsatile conditions at a specific frequency, independent of the applied SS. Vascular endothelial and pulmonary epithelial cell proliferation peaked under 1 Hz pulsatile flow. In contrast, proliferation of gastrointestinal cells, which in their physiological context are subject to no flow or higher wavelength signal, was maximum at 0.125 Hz or under no flow. Moreover, exposure of BAEC to pulsatile flow of varying frequency influenced their nitric oxide synthase activity and prostacyclin production, which reached maximum values at 1 Hz. Notably, the "optimal" frequencies for the cell types examined correspond to the physiologic operating range of the organs from where they were initially derived. These findings suggest that frequency, independent of shear, is an essential determinant of cell response in pulsatile environments. (c) 2004 Wiley-Liss, Inc.

  11. Hot cell examination on the surveillance capsule of SA 533 cl. 1 reactor pressure vessel (1st test report)

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Yong Sun; Jung, Y. H.; Yoo, B. O.; Baik, S. J.; Oh, W. H.; Soong, W. S.; Hong, K. P

    2000-08-01

    The post-irradiated examinations such as impact test, tensile test, composition analysis and etc. were conducted to monitor and to evaluate the radiation-induced changes, so called radiation embrittlement, in the mechanical properties of ferritic materials. Those data should be applied to confirm safety as well as reliability of reactor pressure vessel. The scopes and contents of hot cell examination on the surveillance capsule are as follows; - Capsule transportation, cutting, dismantling and classification - Shim block and Dosimeter cutting and dismantling - Impact test - Tensile test - Composition analysis by EPMA - SEM observation on the fractured surface - Hardness test - Radwaste treatment.

  12. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste...... in hot wire anemometry is the description of the Nusselt number as function of the Reynolds number and the Prandtl number, and in the current application it can be shown it is essential to employ a power-law equation instead of the commonly employed Churchill Bernstein equation. It will be shown...

  13. Identification of the hot-spot areas for sickle cell disease using cord blood screening at a district hospital: an Indian perspective

    OpenAIRE

    Dixit, Sujata; Sahu, Pushpansu; Kar, Shantanu Kumar; Negi, Sapna

    2015-01-01

    Sickle cell disease (SCD), a genetic disorder often reported late, can be identified early in life, and hot-spot areas may be identified to conduct genetic epidemiology studies. This study was undertaken to estimate prevalence and to identify hot spot area for SCD in Kalahandi district, by screening cord blood of neonates delivered at the district hospital as first-hand information. Kalahandi District Hospital selected for the study is predominated by tribal population with higher prevalence ...

  14. Pulvinus activity, leaf movement and leaf water-use efficiency of bush bean ( Phaseplus vulgaris L.) in a hot environment

    Science.gov (United States)

    Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2008-11-01

    Pulvinus activity of Phaseolus species in response to environmental stimuli plays an essential role in heliotropic leaf movement. The aims of this study were to monitor the continuous daily pulvinus movement and pulvinus temperature, and to evaluate the effects of leaf movements, on a hot day, on instantaneous leaf water-use efficiency (WUEi), leaf gas exchange, and leaf temperature. Potted plants of Phaseolus vulgaris L. var. Provider were grown in Chicot sandy loam soil under well-watered conditions in a greenhouse. When the second trifoliate leaf was completely extended, one plant was selected to measure pulvinus movement using a beta-ray gauging (BRG) meter with a point source of thallium-204 (204Tl). Leaf gas exchange measurements took place on similar leaflets of three plants at an air temperature interval of 33-42°C by a steady-state LI-6200 photosynthesis system. A copper-constantan thermocouple was used to monitor pulvinus temperature. Pulvinus bending followed the daily diurnal rhythm. Significant correlations were found between the leaf-incident angle and the stomatal conductance ( R 2 = 0.54; P photosynthesis rate ( R 2 = 0.84; P light intensity and air temperature and influenced leaf gas exchange.

  15. Effect of vitamin supplementation on lung injury and running performance in a hot, humid, and ozone-polluted environment.

    Science.gov (United States)

    Gomes, E C; Allgrove, J E; Florida-James, G; Stone, V

    2011-12-01

    In this study, the effect of vitamin C and E supplementation on lung injury and performance of runners were analyzed. Using a randomized, double-blinded, crossover design, nine runners participated in two experimental trials: a 2-week Vitamin trial (vitamin C = 500  mg/day + vitamin E = 100  IU/day) and a 2-week Placebo trial. At the end of each supplementation period the runners performed an 8-km time-trial run in a hot (31°C), humid (70% rh), and ozone-polluted (0.10  ppm O(3)) environmental chamber. Nasal lavage and blood samples were collected pre-, post-, and 6-h post-exercise to assess antioxidant status and CC16 as lung injury marker. Higher plasma (pre- and post-exercise) and nasal lavage (post-exercise) antioxidant concentration were found for the Vitamin trial. Nevertheless, this did not result in performance differences (Vitamin trial: 31:05  min; Placebo trial: 31:54  min; P = 0.075) even though significant positive correlations were found between antioxidant concentration and improvement in time to complete the run. CC16 was higher post-exercise in the Placebo trial (P < 0.01) in both plasma and nasal lavage. These findings suggest that antioxidant supplementation might help to decrease the lung injury response of runners when exercising in adverse conditions, but has little effect on performance. © 2011 John Wiley & Sons A/S.

  16. Our Environment in Hot Water: Comparing Water Heaters, A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Alison; McMahon, James; Masanet, Eric; Lutz, Jim

    2008-08-13

    Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union's Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory's Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

  17. The Multiparametric Effects of Hydrodynamic Environments on Stem Cell Culture

    Science.gov (United States)

    Kinney, Melissa A.; Sargent, Carolyn Y.

    2011-01-01

    Stem cells possess the unique capacity to differentiate into many clinically relevant somatic cell types, making them a promising cell source for tissue engineering applications and regenerative medicine therapies. However, in order for the therapeutic promise of stem cells to be fully realized, scalable approaches to efficiently direct differentiation must be developed. Traditionally, suspension culture systems are employed for the scale-up manufacturing of biologics via bioprocessing systems that heavily rely upon various types of bioreactors. However, in contrast to conventional bench-scale static cultures, large-scale suspension cultures impart complex hydrodynamic forces on cells and aggregates due to fluid mixing conditions. Stem cells are exquisitely sensitive to environmental perturbations, thus motivating the need for a more systematic understanding of the effects of hydrodynamic environments on stem cell expansion and differentiation. This article discusses the interdependent relationships between stem cell aggregation, metabolism, and phenotype in the context of hydrodynamic culture environments. Ultimately, an improved understanding of the multifactorial response of stem cells to mixed culture conditions will enable the design of bioreactors and bioprocessing systems for scalable directed differentiation approaches. PMID:21491967

  18. A shirt containing multistage phase change material and active cooling components was associated with increased exercise capacity in a hot, humid environment.

    Science.gov (United States)

    McFarlin, Brian K; Henning, Andrea L; Venable, Adam S; Williams, Randall R; Best Sampson, Jill N

    2016-08-01

    Recent advances in clothing design include the incorporation of phase change materials (PCM) and other active cooling components (ACC) to provide better body heat dissipation. The purpose of this study was to determine the effect of wearing a shirt containing multistage PCM/ACC on exercise capacity at low (5.0), moderate-high (7.5) and extreme (9.0) levels of the physiological strain index (PSI). Fourteen individuals tested two shirts (control vs. cooling) during 45-min of interval running in a hot, humid (35 ± 1 °C; 55 ± 6% RH) environment. The cooling shirt resulted in an 8% improvement in exercise capacity at a PSI of 7.5 (p phase change material and active cooling components.

  19. Effect of Palm Cooling with Negative Pressure on Heat Balance During Exercise in a Hot, Dry Environment

    Science.gov (United States)

    2006-11-15

    conditions until their core temperature (pill or rectal) reached 38.5oC. A venous blood sample (5 mL) was obtained from an antecubital vein...Aviat. Space Environ. Med. 71:939-945, 2000. Livingstone SD, RW Nolan, SW Cattroll. Heat loss caused by immersing the hands in water. Aviat... Space Environ. Med. 60:1166-1171, 1989. McNair, P. M., Lorr, M. & Droppleman, L. F. POMS manual (2nd ed.). San Diego: San Diego Educational and

  20. Surveillance and radiological protection in the Hot Cell laboratory; Vigilancia y proteccion radiologica en el Laboratorio de Celdas Calientes

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, J.M.; Torre, J. De la; Garcia C, M.A. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    The Hot Cells Laboratory (LCC) located in the National Institute of Nuclear Research are an installation that was designed for the management at distance of 10,000 Curies of Co-60 or other radioactive materials with different values in activity. The management of such materials in the installation, implies to analyze and to determine the doses that the POE will receive as well as the implementation of protection measures and appropriate radiological safety so that is completed the specified by the ALARA concept. In this work it is carried out an evaluation of the doses to receive for the POE when managing radionuclides with maximum activities that can be allowed in function of the current conditions of the cells and an evaluation of results is made with the program of surveillance and radiological protection implemented for the development of the works that carried out in the installation. (Author)

  1. Hot laboratory in Saclay. Equipment and radio-metallurgy technique of the hot lab in Saclay. Description of hot cell for handling of plutonium salts. Installation of an hot cell; Laboratoire a tres haute activite de Saclay. Equipement et techniques radiometallurgiques du laboratoire a haute activite de Saclay. Description de cellules pour manipulation de sels de plutonium. Amenagement d'une cellule du laboratoire de haute activite

    Energy Technology Data Exchange (ETDEWEB)

    Bazire, R.; Blin, J.; Cherel, G.; Duvaux, Y.; Cherel, G.; Mustelier, J.P.; Bussy, P.; Gondal, G.; Bloch, J.; Faugeras, P.; Raggenbass, A.; Raggenbass, P.; Fufresne, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    Describes the conception and installation of the hot laboratory in Saclay (CEA, France). The construction ended in 1958. The main aim of this laboratory is to examine fuel rods of EL2 and EL3 as well as nuclear fuel studies. It is placed in between both reactors. In a first part, the functioning and specifications of the hot lab are given. The different hot cells are described with details of the ventilation and filtration system as well as the waste material and effluents disposal. The different safety measures are explained: description of the radiation protection, decontamination room and personnel monitoring. The remote handling equipment is composed of cutting and welding machine controlled with manipulators. Periscopes are used for sight control of the operation. In a second part, it describes the equipment of the hot lab. The unit for an accurate measurement of the density of irradiated uranium is equipped with an high precision balance and a thermostat. The equipment used for the working of irradiated uranium is described and the time length of each operation is given. There is also an installation for metallographic studies which is equipped with a manipulation bench for polishing and cleaning surfaces and a metallographic microscope. X-ray examination of uranium pellets will also be made and results will be compared with those of metallography. The last part describes the hot cells used for the manipulation of plutonium salts. The plutonium comes from the reprocessing plant and arrived as a nitric solution. Thus these cells are used to study the preparation of plutonium fluorides from nitric solution. The successive operations needed are explained: filtration, decontamination and extraction with TBP, purification on ion exchangers and finally formation of the plutonium fluorides. Particular attention has been given to the description of the specifications of the different gloveboxes and remote handling equipment used in the different reaction steps and

  2. Identification of novel esterase-active enzymes from hot environments by use of the host bacterium Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Benedikt eLeis

    2015-04-01

    Full Text Available Functional metagenomic screening strategies, which are independent of known sequence information, can lead to the identification of truly novel genes and enzymes. Since E. coli has been used exhaustively for this purpose as a host, it is important to establish alternative expression hosts and to use them for functional metagenomic screening for new enzymes. In this study we show that Thermus thermophilus HB27 is an excellent screening host and can be used as an alternative provider of truly novel biocatalysts. In a previous study we constructed the mutant strain BL03 that was no longer able to grow on defined minimal medium supplemented with tributyrin as the sole carbon source and could be used as a host to screen for metagenomic DNA fragments that could complement growth on tributyrin. Several thousand single fosmid clones from thermophilic metagenomic libraries from heated compost and hot spring water samples were subjected to a comparative screening for esterase activity in both T. thermophilus strain BL03 and E. coli EPI300. We scored a greater number of active clones in the thermophilic bacterium than in the mesophilic E. coli. From all clones functionally screened in E. coli, only two thermostable α/β-fold hydrolase enzymes with high amino acid sequence similarity to already characterized enzymes were identifiable. In contrast, five further fosmids were found that conferred lipolytic activities in T. thermophilus. Four open reading frames (ORFs were found which did not share significant similarity to known esterase enzymes. Two of the genes were expressed in both hosts and the novel thermophilic esterases, which based on their primary structures could not be assigned to known esterase or lipase families, were purified and preliminarily characterized. Our work underscores the benefit of using additional screening hosts other than E. coli for the identification of novel biocatalysts with industrial relevance.

  3. Mechanisms for fast cell migration in complex environments.

    Science.gov (United States)

    Vargas, Pablo; Barbier, Lucie; Sáez, Pablo José; Piel, Matthieu

    2017-10-01

    Cell migration depends on a combination of the cell's intrinsic capacity to move and the proper interpretation of external cues. This multistep process enables leukocytes to travel long distances in organs in just a few hours. This fast migration is partly due to the leukocytes' high level of plasticity, which helps them to adapt to a changing environment. Here, we review recent progress in understanding the mechanisms used by leukocytes to move rapidly and efficiently in intricate anatomical landscapes. We shall focus on specific cytoskeletal rearrangements used by neutrophils and dendritic cells to migrate within confined environments. Lastly, we will describe the properties that facilitate the rapid migration of leukocyte in complex tissue geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Tumor Cells and Micro-environment in Brain Metastases

    Directory of Open Access Journals (Sweden)

    Wen ZHONG

    2016-09-01

    Full Text Available Improvements in survival and quality of life of patients with lung cancer had been achieved due to the progression of early diagnosis and precision medicine at recent years, however, until now, treatments targeted at lesions in central nervous system are far from satisfying, thus threatening livelihood of patients involved. After all, in the issue of prophylaxis and therapeutics of brain metastases, it is crucial to learn about the biological behavior of tumor cells in brain metastases and its mechanism underlying, and the hypothesis ”seed and soil”, that is, tumor cells would generate series of adaptive changes to fit in the new environment, is liable to help explain this process well. In this assay, we reviewed documents concerning tumor cells, brain micro-environments and their interactions in brain metastases, aiming to provide novel insight into the treatments of brain metastases.

  5. Hot Flashes

    Science.gov (United States)

    ... Risk factors Not all women who go through menopause have hot flashes, and it's not clear why some women do have them. Factors that may increase your risk include: Smoking. Women who smoke are more likely to get hot flashes. Obesity. A high body mass index (BMI) is associated ...

  6. Hot flushes

    African Journals Online (AJOL)

    without thermoregulatory homeostatic mechanisms, such as sweating, being triggered. Small fluctuations in core body. Abstract. Vasomotor symptoms, such as hot flushes and night sweats, are considered to be the cardinal symptoms of menopause, and are experienced by most women. The physiology of hot flushes is not ...

  7. An Overt Chemical Protective Garment Reduces Thermal Strain Compared with a Covert Garment in Warm-Wet but Not Hot-Dry Environments

    Directory of Open Access Journals (Sweden)

    Matthew J. Maley

    2017-11-01

    exertion did not differ between garments at trial cessation (P > 0.05.Conclusion: Those dressed in OVERT experienced lower thermal strain and longer work tolerance times compared with COVERT in a warm-wet environment. However, COVERT may be an optimal choice in a hot-dry environment. These findings have practical implications for those making decisions on the choice of CBRN ensemble to be used during work.

  8. Modelling of a solid oxide fuel cell CHP system coupled with a hot water storage tank for a single household

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Zhao, Yingru; Yang, Wenyuan

    2015-01-01

    In this paper a solid oxide fuel cell (SOFC) system for cogeneration of heat and power integrated with a stratified heat storage tank is studied. The use of a storage tank with thermal stratification allows one to increase the annual operating hours of CHP: heat can be produced when the request...... that in the case of syngas, due to larger system heat output, a larger tank volume was required in order to accumulate unused heat over the night. The detailed description of the tank model will be useful to energy system modelers when sizing hot water tanks. Problem formulation is reported also using a Matlab...... is low (for instance during the night), taking advantage of thermal stratification to increases the heat recovery performance. A model of the SOFC system is presented to estimate the energy required to meet the average electric energy demand of the residence. Two fuels are considered, namely syngas...

  9. Optimized Packing Density of Large CZTS Nanoparticles Synthesized by Hot-injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    the organic ligands by an antimony salt; however the efficiency is 1.4% for a cell annealed in Se-atmosphere. In our work, we try to limit the carbon amount in the film by synthesizing larger nanoparticles. The bigger the particles are the smaller surface-to-volume ratio they have, which might decrease......, but to maintain good control of the nanocrystal formation during the synthesis, it is necessary to have organic ligands on the surface of the particles. These ligands are often long alkyl chains that potentially limit the quality of the film and degrade its electronic properties. For nanocrystal solution...... the amount of ligands necessary to stabilize the particles in solution. Today, CZTS nanoparticles synthesized through the so-called hot-injection method vary between 2 nm and 60 nm in diameter. In our group, we have synthesized particles larger than 200 nm. Transmission electron microscopy (TEM) allows us...

  10. Performance of a solid oxide fuel cell CHP system coupled with a hot water storage tank for single household

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Zhao, Yingru; Yang, Wenyuan

    2014-01-01

    In this paper a solid oxide fuel cell (SOFC) system for cogeneration of heat and power integrated with a stratified heat storage tank is studied. Thermal stratification in the tank increases the heat recovery performance as it allows existence of a temperature gradient with the benefit...... of delivering hot water for the household and returning the coldest fluid back to SOFC heat recovery heat-exchanger. A model of the SOFC system is developed to determine the energy required to meet the hourly average electric load of the residence. The model evaluates the amount of heat generated and the amount...... of heat used for thermal loads of the residence. Two fuels are considered, namely syngas and natural gas. The tank model considers the temperature gradients over the tank height. The results of the numerical simulation is used to size the SOFC system and storage heat tank to provide energy for a small...

  11. Prediction of Hot Spots at Myeloid Cell Leukemia-1-Inhibitors Interface using Energy Estimation and Alanine Scanning Mutagenesis.

    Science.gov (United States)

    Marimuthu, Parthiban; Singaravelu, Kalaimathy

    2018-01-18

    Myeloid cell leukemia 1 (Mcl1) is an anti-apoptotic protein that plays central role in apoptosis regulation. Also, Mcl1 has the potency to resist apoptotic cues resulting in up-regulation and cancer cell protection. A molecular probe that has the potential to specifically target Mcl1, and thereby provoke its down-regulatory activity is very essential. The aim of the current study is to probe the internal conformational dynamics of protein motions and potential binding mechanism in response to a series of picomolar range Mcl1 inhibitors using explicit-solvent molecular dynamics (MD) simulations. Subsequently, the domain cross-correlation and principal component analysis was performed on the snapshots obtained from the MD simulations. Our results showed significant differences in the internal conformational dynamics of Mcl1 w.r.t binding affinity values of inhibitors. Further, the binding free energy estimation -using three different samples- was performed on the MD simulations, which revealed the predicted energies (ΔGmmgbsa) were in good correlation with the experimental values (ΔGexpt). Also, the energies obtained using all sampling models were efficiently ranked. Subsequently, the decomposition energy analysis highlighted the major energy-contributing residues at the Mcl1 binding pocket. Computational alanine scanning performed on high energy-contributing residues predicted the hot spot residues. The dihedral angle analysis using MD snapshots on the predicted hot spot residue exhibited consistency in side chain conformational motion that ultimately led to contribute strong binding affinity values. The findings from the present study might provide valuable guidelines for the design of novel Mcl1 inhibitors that might significantly improve the specificity for new-generation chemotherapeutic agents.

  12. The Effect of Various Hot Environments on Physiological Responses and Information Processing Performance Following Firefighting Activities in a Smoke-Diving Room

    Directory of Open Access Journals (Sweden)

    Rasoul Hemmatjo

    2017-12-01

    Full Text Available Background: Fire service workers often implement multiple duties in the emergency conditions, with such duties being mostly conducted in various ambient temperatures. Methods: The aim of the current study was to assess the firefighters' physiological responses, information processing, and working memory prior to and following simulated firefighting activities in three different hot environments. Seventeen healthy male firefighters performed simulated firefighting tasks in three separate conditions, namely (1 low heat (LH; 29–31°C, 55–60% relative humidity, (2 moderate heat (MH; 32–34°C, 55–60% relative humidity, and (3 severe heat (SH; 35–37°C, 55–60% relative humidity. It took about 45–50 minutes for each firefighter to finish all defined firefighting activities and the paced auditory serial addition test (PASAT. Results: At the end of all the three experimental conditions, heart rate (HR and tympanic temperature (TT increased, while PASAT scores as a measure of information processing performance decreased relative to baseline. HR and TT were significantly higher at the end of the experiment in the SH (159.41±4.25 beats/min; 38.22±0.10°C compared with the MH (156.59±3.77 beats/min; 38.20±0.10°C and LH (154.24±4.67 beats/min; 38.17±0.10°C conditions (p0.05. Nonetheless, there was a measurable difference in PASAT scores between LH and SH (p<0.05. Conclusion: These consequences demonstrate that ambient temperature is effective in raising the physiological responses following firefighting activities. It is therefore argued that further increase of ambient temperature can impact firefighters' information processing and working memory during firefighting activity. Keywords: firefighting, hot environment, information processing, physiological responses, working memory

  13. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell for a pre-humidified hydrogen stream

    DEFF Research Database (Denmark)

    Berning, Torsten; Shakhshir, Saher Al

    2016-01-01

    In a recent publication it has been shown how the water balance in a proton exchange membrane fuel cell can be determined employing hot wire anemometry. The hot wire sensor has to be placed into the anode outlet pipe of the operating fuel cell, and the voltage signal E that is read from the sensor....... Finally, it will be shown how previously developed dew point diagrams for the anode side in a fuel cell can be corrected for a humidified hydrogen inlet stream....... has to be divided by a pre-determined voltage signal E0 that has been obtained for a stream of dry hydrogen where the molar flow rate corresponds to a total current I of the fuel cell stack and a stoichiometric flow ratio, ξ. Because the last two properties are usually continuously known in fuel cell...

  14. Temperature Measurement Inside Protective Headgear: Comparison With Core Temperatures and Indicators of Physiological Strain During Exercise in a Hot Environment.

    Science.gov (United States)

    Mitchell, Joel B; Goldston, Kelly R; Adams, Amy N; Crisp, Kelli M; Franklin, Brian B; Kreutzer, Andreas; Montalvo, Diego X; Turner, Marcell G; Phillips, Melody D

    2015-01-01

    Non-invasive temperature monitoring with a sensor inside protective headgear may be effective in detecting temperatures that are associated with heat illness. The purpose was to establish the relationship between in-hardhat temperatures (Tih) and core temperature (Tc) as measured by rectal (Tre) and esophageal (Tes) probes. Thirty males (age 24.57 ± 4.32 yrs.) completed two trials: continuous submaximal exercise (CSE) and a series of high intensity 30-s sprints (HIE) with a one-minute rest between each. Exercise in both conditions was in a 36(°)C environment (40% RH) while wearing a standard hardhat with sensors mounted on the forehead that were monitored remotely. Exercise continued until voluntary termination or until Tc reached 39.5(°)C. Temperatures, heart rate, cardiorespiratory, and perceptual responses were monitored throughout. A physiological strain index (PSI) was calculated from Tc and HR. The final temperatures in the CSE condition were 38.77 ± 0.41, 38.90 ± 0.49 and 39.29 ± 0.58(°)C and in the HIE condition, final temperatures were 38.76 ± 0.37, 38.91 ± 0.47, and 39.19 ± 0.57 f (o)C for Tih, Tre, and Tes, respectively. The PSI in CSE was 9.62 ± 062, 9.18 ± 1.11, and 10.04 ± 1.05, and in the HIE condition 9.67 ± 068, 9.29 ± 0.99. and 9.86 ± 1.02 based on Tih, Tre and Tes, respectively. The general agreement between the Tih and other temperature measures along with the consistency as indicated by a low coefficient of variation (approx. 1%) in the recordings of the Tih sensors at the point of termination suggest that this device, or similar devices, may have application as a warning system for impending heat-related problems.

  15. Viscum Album Var Hot Water Extract Mediates Anti-cancer Effects through G1 Phase Cell Cycle Arrest in SK-Hep1 Human Hepatocarcinoma cells.

    Science.gov (United States)

    dela Cruz, Joseph Flores; Kim, Yeon Soo; Lumbera, Wenchie Marie Lara; Hwang, Seong Gu

    2015-01-01

    Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400 ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells.

  16. Longevity and efficacy of bifenthrin treatment on desert-pattern US military camouflage netting against mosquitoes in a hot-arid environment.

    Science.gov (United States)

    Britch, Seth C; Linthicum, Kenneth J; Wynn, Willard W; Aldridge, Robert L; Walker, Todd W; Farooq, Muhammad; Dunford, James C; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Wittie, Jeremy; White, Gregory

    2011-09-01

    The current Department of Defense pest management system does not provide adequate protection from arthropod disease vectors to personnel deployed in support of US military operations. We hypothesized that military camouflage netting, ubiquitous around living and working areas in current US military operations in Africa and the Middle East, treated with a residual pesticide such as bifenthrin may reduce the presence of biting insects and improve the military pest management system. In this study, we examined the longevity and efficacy of bifenthrin applied to camouflage netting material at the maximum label rate of 0.03 liter formulation (7.9% AI) per 92.9 m2 against field populations of mosquitoes in southern California in a hot-arid environment similar to regions of Iraq, Afghanistan, and the Horn of Africa. We showed that bifenthrin treatment of camouflage netting was effective at reducing mosquito populations, predominantly Psorophora columbiae and Aedes vexans, by an average of up to 46% for 56 days, and could cause as much as 40% mortality in Culex quinquefasciatus in laboratory bioassays for nearly 2 months postapplication. These population reductions could translate to commensurate reductions in risk of exposure to mosquito-borne pathogens, and could potentially be effective against sand flies and filth flies.

  17. PERAN KECEPATAN ANGIN TERHADAP PENINGKATAN KENYAMANAN TERMIS MANUSIA DI LINGKUNGAN BERIKLIM TROPIS LEMBAB (The Role of Wind Velocity on Increasing Human Thermal Comfort in Hot and Humid Environment

    Directory of Open Access Journals (Sweden)

    Sangkertadi Sangkertadi

    2006-07-01

    Full Text Available ABSTRAK Faktor utama yang mempengaruhi persepsi kenyamanan termis pada manusia adalah : pakaian, suhu, kelembaban dan kecepatan udara sekitar, serta jenis aktivitasnya. Di daerah beriklim panas dan lembab, rasa tidak nyaman berkaitan erat dengan keluarnya keringat. Angin dengan debit dan kecepatan tertentu dapat difungsikan untuk mendinginkan penghuni bangunan melalui proses evaporasi keringat dan proses perpindahan kalor secara konvektif. Tulisan ini menyajikan pendalaman tentang teknik mengevaluasi tingkat kenyamanan termis manusia di daerah beriklim tropis lembab khususnya dengan menggunakan skala DISC dan PMV. Studi ini difokuskan pada pengaruh kecepatan angin untuk meningkatkan kenyamanan termis manusia. Metode yang dipakai adalah simulasi numerik dengan menggunakan sejumlah persamaan praktis untuk penghitungan kenyamanan termis.   ABSTRACT The most important factors which influence the condition of thermal comfort are clothing, temperature, humidity, air velocity, and types of activities. In hot and humid climate, feeling of comfort are associated with sweating. Air velocity can cool building occupants by increasing convective and evaporative heat loses. This paper intends to explore the techniques for evaluating of thermal comfort especially with introduction of PMV and DISC scales for the tropical humid environment. The study is focused on the influence of air velocity to the scale number of both DSC and PMV. A simple numerical simulation with some of empirical correlations are used to estimate the index of thermal comfort

  18. Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC) - the Hot Start experience.

    Science.gov (United States)

    De Sousa, Paul A; Steeg, Rachel; Wachter, Elisabeth; Bruce, Kevin; King, Jason; Hoeve, Marieke; Khadun, Shalinee; McConnachie, George; Holder, Julie; Kurtz, Andreas; Seltmann, Stefanie; Dewender, Johannes; Reimann, Sascha; Stacey, Glyn; O'Shea, Orla; Chapman, Charlotte; Healy, Lyn; Zimmermann, Heiko; Bolton, Bryan; Rawat, Trisha; Atkin, Isobel; Veiga, Anna; Kuebler, Bernd; Serano, Blanca Miranda; Saric, Tomo; Hescheler, Jürgen; Brüstle, Oliver; Peitz, Michael; Thiele, Cornelia; Geijsen, Niels; Holst, Bjørn; Clausen, Christian; Lako, Majlinda; Armstrong, Lyle; Gupta, Shailesh K; Kvist, Alexander J; Hicks, Ryan; Jonebring, Anna; Brolén, Gabriella; Ebneth, Andreas; Cabrera-Socorro, Alfredo; Foerch, Patrik; Geraerts, Martine; Stummann, Tina C; Harmon, Shawn; George, Carol; Streeter, Ian; Clarke, Laura; Parkinson, Helen; Harrison, Peter W; Faulconbridge, Adam; Cherubin, Luca; Burdett, Tony; Trigueros, Cesar; Patel, Minal J; Lucas, Christa; Hardy, Barry; Predan, Rok; Dokler, Joh; Brajnik, Maja; Keminer, Oliver; Pless, Ole; Gribbon, Philip; Claussen, Carsten; Ringwald, Annette; Kreisel, Beate; Courtney, Aidan; Allsopp, Timothy E

    2017-04-01

    A fast track "Hot Start" process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was surveyed to arrive at harmonised and publically accessible Standard Operations Procedures (SOPs) for tissue procurement, bio-sample tracking, iPSC expansion, cryopreservation, qualification and distribution to the research community. These were implemented to create a quality managed foundational collection of lines and associated data made available for distribution. Here we report on the successful outcome of this experience and work flow for banking and facilitating access to an otherwise disparate European resource, with lessons to benefit the international research community. ETOC: The report focuses on the EBiSC experience of rapidly establishing an operational capacity to procure, bank and distribute a foundational collection of established hiPSC lines. It validates the feasibility and defines the challenges of harnessing and integrating the capability and productivity of centres across Europe using commonly available resources currently in the field. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Dose levels in the hot cells area ININ; Niveles de dosis en el area de celdas calientes-ININ

    Energy Technology Data Exchange (ETDEWEB)

    Torre, J. De la; Ramirez, J.M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Solis, M.L. [UAEM, Toluca, Estado de Mexico (Mexico)]. E-mail: jto@nuclear.inin.mx

    2004-07-01

    The Laboratory of Hot Cells (LCC) located in the National Institute of Nuclear Research (ININ) is an institution, it is an area where radioactive material is managed with different activity values, in function of its original design for 10,000 curies of Co-60. Managing this materials in the installation, it implies to measure and to analyze the dose levels that the POE will receive as well as the implementation of appropriate measures of radiological protection and radiological safety, so that that is completed settled down by the concept ALARA. In this work they are carried out mensurations of the levels of the dose to receive for the POE when managing radionuclides with maximum activities that can be allowed in function of the current conditions of the cells and an evaluation of the obtained results is made comparing them with the effective international norms as well as the application of the program of surveillance and radiological protection implemented for the development of the works that are carry out in the installation. (Author)

  20. Improvement of the efficiency of triple junction n–i–p solar cells with hot-wire CVD proto- and microcrystalline silicon absorber layers

    NARCIS (Netherlands)

    Stolk, R.L.; Li, H. B. T.; Franken, R.H.; Schuttauf, J.A.; van der Werf, C.H.M.; Rath, J.K.; Schropp, R.E.I.

    2008-01-01

    Hot-wire chemical vapour deposition (HWCVD) was applied for the deposition of intrinsic protocrystalline (proto-Si:H) and microcrystalline silicon (μc-Si:H) absorber layers in thin film solar cells. For a single junction μc-Si:H n–i–p cell on a Ag/ZnO textured back reflector (TBR) with a 2.0 μm

  1. Early stage hot spot analysis through standard cell base random pattern generation

    Science.gov (United States)

    Jeon, Joong-Won; Song, Jaewan; Kim, Jeong-Lim; Park, Seongyul; Yang, Seung-Hune; Lee, Sooryong; Kang, Hokyu; Madkour, Kareem; ElManhawy, Wael; Lee, SeungJo; Kwan, Joe

    2017-04-01

    Due to limited availability of DRC clean patterns during the process and RET recipe development, OPC recipes are not tested with high pattern coverage. Various kinds of pattern can help OPC engineer to detect sensitive patterns to lithographic effects. Random pattern generation is needed to secure robust OPC recipe. However, simple random patterns without considering real product layout style can't cover patterning hotspot in production levels. It is not effective to use them for OPC optimization thus it is important to generate random patterns similar to real product patterns. This paper presents a strategy for generating random patterns based on design architecture information and preventing hotspot in early process development stage through a tool called Layout Schema Generator (LSG). Using LSG, we generate standard cell based on random patterns reflecting real design cell structure - fin pitch, gate pitch and cell height. The output standard cells from LSG are applied to an analysis methodology to assess their hotspot severity by assigning a score according to their optical image parameters - NILS, MEEF, %PV band and thus potential hotspots can be defined by determining their ranking. This flow is demonstrated on Samsung 7nm technology optimizing OPC recipe and early enough in the process avoiding using problematic patterns.

  2. Hot wire CVD deposition of nanocrystalline silicon solar cells on rough substrates

    NARCIS (Netherlands)

    Li, H. B. T.; van der Werf, C.H.M.; Rath, J.K.; Schropp, R.E.I.

    2009-01-01

    In silicon thin film solar cell technology, frequently rough or textured substrates are used to scatter the light and enhance its absorption. The important issue of the influence of substrate roughness on silicon nanocrystal growth has been investigated through a series of nc-Si:H single junction

  3. Hot-Wire Chemical Vapor Deposition Of Polycrystalline Silicon : From Gas Molecule To Solar Cell

    NARCIS (Netherlands)

    Veenendaal, P.A.T.T. van

    2002-01-01

    Although the effort to investigate the use of renewable energy sources, such as wind and solar energy, has increased, their contribution to the total energy consumption remains insignificant. The conversion of solar energy into electricity through solar cells is one of the most promising techniques,

  4. Effect of protection against hot climate on growth performance, physiological response and endocrine profile of growing lambs under semi-arid tropical environment.

    Science.gov (United States)

    De, Kalyan; Kumar, Davendra; Singh, Anoop Kumar; Kumar, Kamal; Sahoo, Artabandhu; Naqvi, Syed Mohammed Khursheed

    2017-08-01

    In the hot semi-arid tropical region, extreme summer is a major constraint in sheep production. The growth performance of growing lambs is impaired during the summer. Therefore, the present study was conducted to assess the effect of protection against hot climate on growth performance, physiological response, and endocrine profile of growing lambs under semi-arid tropical environment. All the data in the experiment were presented as mean ± SE. Thirty Malpura lambs with the age of 122.7 ± 6.05 days and body weight of 19.52 ± 0.42 kg were allotted into three groups, viz. G1 (control, lambs kept in open area under tree shade), G2 (lambs kept in conventional asbestos-roofed shed), and G3 (lambs kept in designed shed). The allotment was based on their initial body weight so that the mean body weight of each group was similar. In all three types of protection, lambs were provided with sufficient space to move and social interaction. In asbestos-roofed shed (G2), all the four sides from ground to the roof were fenced with strong galvanized iron chain link. But in G3, all the four sides were constructed in a manner that there was 0.13 m air space between inner and outer solid brick columns of the wall up to 1.37 m height, and rest up to the roof was fenced with bamboo splint net. The air space between the two columns of the wall was filled with sand, and it was kept in moist condition by continuous water drips which provide extra evaporative cooling. The designed shed was basically constructed with bamboo. Tree shade was assured under the natural shades of large trees. The shaded area was protected by wire fences. The experiment was conducted for 45 days during very high temperature (May-June). The lambs were provided with ad libitum green fodder, dry roughage, 300 g concentrate, and ad libitum drinking water. The respiration rate at morning and afternoon, pulse rate at morning and afternoon and rectal temperature at afternoon was significantly (P  0

  5. [Cell-host-parasite interactions: biodiversity, pathogenesis, environment].

    Science.gov (United States)

    Villena, I; Aubert, D; Pinon, J-M

    2006-03-01

    The apicomplexan Toxoplasma gondii, an obligate intracellular parasite, can infect humans and a wide range of vertebrates leading to toxoplasmosis. This generally benign affection can causes severe life-threatening disease, particularly in immunocompromised patients and in children with congenital toxoplasmosis. Our research team works on cell-host-parasite interactions by studying biodiversity, pathogenic mechanisms and environment. We search to identify prognostic factors of disease and markers of resistance. This project is an integral part of our Research Institute (IFR53) which receives support from the Toxoplasma Biological Resource Center for constituting a bank of well characterized toxoplasma isolates for genotyping, clinical and epidemiological data. The involvement of metalloproteinases implicated during monocytic cell invasion and identification of ABC transporter proteins in T. gondii, factors implicated in resistance, need to be explored.

  6. Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

    Science.gov (United States)

    Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

    In addition to the several extreme environments on Earth, Space can be considered as just another exceptional environment with a unique mixture of stress factors comprising UV radiation, vacuum, desiccation, temperature, ionizing radiation and microgravity. Life that processes in these environments can depend on the life forms and their state of living. The question is whether there are different strategies for individual microorganisms compared to communities of the same organisms to cope with the different factors of their surroundings. Comparative studies of the survi-val of these communities called biofilms and planktonic cell samples of Deinococcus geothermalis stand at the focal point of the presented investigations. A biofilm is a structured community of microorganisms that live encapsulated in a matrix of extracellular polymeric substances on a surface. Microorganisms living in a biofilm usually have significantly different properties to cooperate than individually living microorganisms of the same species. An advantage of the biofilm is increased resistance to various chemical and physical effects, while the dense extracellular matrix and the outer layer of the cells protect the interior of the microbial consortium. The space experiment BOSS (Biofilm organisms surfing Space) as part the ESA experimental unit EXPOSE R-2 with a planned launch date in July 2014 will be subsequently mounted on the Russian Svesda module outside the ISS. An international team of scientists coordinated by Dr. P. Rettberg will investigate the hypothesis whether microorganisms organized as biofilm outmatch the same microorganisms exposed individually in the long-term survival of the harsh environmental conditions as they occur in space and on Mars. Another protective function in the samples could be dust par-ticles for instance Mars regolith simulant contained inside the biofilms or mixed with the planktonic cells, as additional shelter especially against the extraterrestrial UV

  7. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    microscopy (SEM) as well as other surface characterization techniques. Our first photovoltaic device consisting of soda lime glass/Mo/CZTS/CdS/ZnO has been built from doctor blading of approx. 20 nm Cu2ZnSnS4 NPs in octanethiol, and annealed in Se-atmosphere. It had an efficiency of 1.4%.......The kesterite material, Cu2ZnSn(SxSe1-x)4 (CZTS), shows great promise as the absorber layer for future thin film solar cells. Solution processing allows for comparatively fast and inexpensive fabrication, and holds the record efficiency in the kesterite family. However, for nanoparticle (NP...

  8. Late-Onset Metastasis of Renal Cell Carcinoma into a Hot Thyroid Nodule: An Uncommon Finding Not to Be Overlooked

    Directory of Open Access Journals (Sweden)

    Luca Foppiani

    2015-01-01

    Full Text Available We report the case of a 74-year-old man with a four-year history of right nephrectomy for clear cell renal carcinoma (CCRC who was diagnosed with hyperthyroidism. On ultrasound (US, a 5 cm solid isohypoechoic nodule with intranodular vascularization was found in the left thyroid lobe. The nodule was deemed autonomous on T99mc thyroid scan. Methimazole was started and serum thyroid hormone levels quickly normalized; euthyroidism was maintained with a very low dosage of antithyroid drug. Over time, compressive symptoms and local pain occurred and US revealed growth of the nodule. Total thyroidectomy was performed and the combined histological and immunohistochemical evaluation deemed the nodule compatible with metastasis of CCRC; on 2-year follow-up, no tumor relapse was ascertained. In patients with a history of cancer, a thyroid nodule, even if hyperfunctioning, must be suspected of being a metastasis and investigated. Hot nodules, which are largely benign, may be vulnerable to metastatic colonization owing to their rich vascularization. In these cases, surgery may be curative.

  9. Hot spots

    National Research Council Canada - National Science Library

    Nia, Amir M; Gassanov, Natig; Er, Fikret

    2014-01-01

    ..., several reddened skin lesions were observed. The obvious ''hot spots'' were located on both sides in the groin and above the bladder, with extension to the genital region, compli- cating the ability to catheterize the patient (Figure 1). The rest of the body surface was not affected, and no infectious source for the skin lesions was evident. After suc...

  10. Behaviour of Endothelial Cells in a Tridimensional In Vitro Environment

    Directory of Open Access Journals (Sweden)

    Raif Eren Ayata

    2015-01-01

    Full Text Available Angiogenesis is a fundamental process in healing, tumor growth, and a variety of medical conditions. For this reason, in vitro angiogenesis is an area of interest for researchers. Additionally, in vitro angiogenesis is important for the survival of prevascularized tissue-engineering models. The aim of this study was to observe the self-tubular organization behaviour of endothelial cells in the self-assembly method. In this study, bilayered and dermal substitutes were prepared using the self-assembly method. Histological, immunostaining, and biochemical tests were performed. The behavioural dynamics of endothelial cells in this biological environment of supportive cells were observed, as were the steps of the in vitro angiogenic cascade with self-organizing capillary-like structures formation. The epidermal component of the substitutes was seen to promote network expansion and density. It also increased the quantity of angiogenic factors (VEGF and Ang-1 without increasing the proinflammatory factor (IL-8. In addition, the increased MMP activity contributed to matrix degradation, which facilitated capillary formation.

  11. Evaluation of the Shielding Performance for the Hot-cell built in 100-MeV Isotope Beam-line of KOMAC

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Min; Park, Sung Kyun; Min, Yi Sub; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This study describes the structure of the hot-cell constructed in KOMAC for radioisotope production and evaluates the shielding performance for the hot-cell via the radiation shielding ability test. Korea multi-purpose accelerator complex (KOMAC) is currently operating 20-MeV and 100-MeV beam-line one by on. Additional 100-MeV beam-line and target room (TR101) are planned for the purpose of the radioisotope production in this year. The initial goal of the radioisotope production is to produce the radioactive isotopes, Sr-82 or Cu-67, used widely for the diagnosis and treatment of the cancer. In order to produce these radioisotopes mentioned, the proton beam with the energy between 70-MeV and 100- MeV at a beam current of 300 μA is irradiated into a solid target made of ZnO or RbCl. After the irradiation of the proton beam during approximately 100 hours, the radioisotope Sr-82 with the radioactivity amount of about 3.8 Ci or the Cu-67 with the amount of about 2.7 Ci will be produced. Radioisotopes produced though this process should be conveyed from the TR101 target room to the PR101 processing room and then in order to be delivered into the place for the next process step, a hot-cell is necessary. Result of the shielding performance evaluation of the hot-cell for producing radioisotopes shows the necessity of the shield reinforcement using lead material at side of the lead glass window.

  12. HOT 2017

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    HOT er en kvalitativ undersøgelse, der hvert år diskuterer og undersøger en lille udvalgt skare af danskkyndige fagpersoners bud på, hvad de er optagede af på literacyområdet her og nu – altså hvilke emner, de vil vurdere som aktuelle at forholde sig til i deres nuværende praksis....

  13. Natural radionuclides in the environment. A contribution for the localization and characterization of natural hot particles in solid samples; Natuerliche Radionuklide in der Umwelt. Ein Beitrag zur Lokalisierung und Charakterisierung natuerlicher Heisser Teilchen in festen Proben

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, A.

    2006-07-01

    In the present thesis appearance, spreading, origin, and mineralogical properties of natural hot particles are studied and the radioecological relevance of these particles judged. For this first relevent quaestions on radioactivity in the environment and on hot particles are theoretically treated. In the following detailedly the method of the autoradiography and solid-state track detectors is considered, which make possible to quote the precise position, the number and distribution of radioactive particles on the cutting area or surface of a sample. Basing on these methodical considerations by laboratory experiments determined track pattern formations of alpha emitters are documentated and interpreted. Starting from the knowledge obtained from this in the further part of the thesis a detection technique is developed, by means of which it is possible, to determine and mark the position of natural hot particles in sold samples. Thereafter follows a description of the electron-microscopical studies for the identification of the localized natural hot particles. Using the developed detection technique, as well as the electron-microscopical methods, a broad spectrum of samples - anthropogeneous depositions (industrial residues, industry products, by-products) and natural depositions (rocks, sediments, minerals) - is studied.

  14. Technical Development of Gamma Scanning for Irradiated Fuel Rod after Upgrade of System in Hot-cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, Hee Moon; Baik, Seung Je; Yoo, Byung Ok; Choo, Yong Sun

    2007-06-15

    Non-destructive test system was installed at hot-cell(M1) in IMEF(Irradiated Materials Examination Facility) more than 10 years ago for the diametric measurement and gamma scanning of fuel rod. But this system must be needed to be remodeled for the effective operations. In 2006, the system was upgraded for 3 months. The collimator bench can be movable with horizontal direction(x-direction) by motorized system for sectional gamma scanning and 3-dimensional tomography of fuel rod. So, gamma scanning for fuel rod can be detectable by x, y and rotation directions. It may be possible to obtain the radioactivities with radial and axial directions of pellet. This system is good for the series experiments with several positions. Operation of fuel bench and gamma detection program were linked each other by new program tools. It can control detection and bench moving automatically when gamma inspection of fuel rod is carried out with axial or radial positions. Some of electronic parts were added in PLC panel, and operating panel was re-designed for the remote control. To operate the fuel bench by computer, AD converter and some I/O cards were installed in computer. All of software were developed in Windows-XP system instead of DOS system. Control programs were made by visual-C language. After upgrade of system, DUPIC fuel which was irradiated in HANARO research reactor was detected by gamma scanning. The results were good and operation of gamma scanning showed reduced inspection time and easy control of data on series of detection with axial positions. With consideration of ECT(Eddy Current Test) installation, the computer program and hardware were set up as well. But ECT is not installed yet, so we have to check abnormal situation of program and hardware system. It is planned to install ECT in 2007.

  15. Glioblastoma-Initiating Cells: Relationship with Neural Stem Cells and the Micro-Environment

    Energy Technology Data Exchange (ETDEWEB)

    Goffart, Nicolas [Laboratory of Developmental Neurobiology, GIGA-Neurosciences Research Center, University of Liège, Liège 4000 (Belgium); Kroonen, Jérôme [Human Genetics, CHU and University of Liège, Liège 4000 (Belgium); The T& P Bohnenn Laboratory for Neuro-Oncology, Department of Neurology and Neurosurgery, UMC Utrecht, Utrecht 3556 (Netherlands); Rogister, Bernard, E-mail: Bernard.Register@ulg.ac.be [Laboratory of Developmental Neurobiology, GIGA-Neurosciences Research Center, University of Liège, Liège 4000 (Belgium); Department of Neurology, CHU and University of Liège, Liège 4000 (Belgium); GIGA-Development, Stem Cells and Regenerative Medicine, University of Liège, Liège 4000 (Belgium)

    2013-08-14

    Glioblastoma multiforme (GBM, WHO grade IV) is the most common and lethal subtype of primary brain tumor with a median overall survival of 15 months from the time of diagnosis. The presence in GBM of a cancer population displaying neural stem cell (NSC) properties as well as tumor-initiating abilities and resistance to current therapies suggests that these glioblastoma-initiating cells (GICs) play a central role in tumor development and are closely related to NSCs. However, it is nowadays still unclear whether GICs derive from NSCs, neural progenitor cells or differentiated cells such as astrocytes or oligodendrocytes. On the other hand, NSCs are located in specific regions of the adult brain called neurogenic niches that have been shown to control critical stem cell properties, to nourish NSCs and to support their self-renewal. This “seed-and-soil” relationship has also been adapted to cancer stem cell research as GICs also require a specific micro-environment to maintain their “stem cell” properties. In this review, we will discuss the controversies surrounding the origin and the identification of GBM stem cells and highlight the micro-environment impact on their biology.

  16. Glioblastoma-Initiating Cells: Relationship with Neural Stem Cells and the Micro-Environment

    Directory of Open Access Journals (Sweden)

    Nicolas Goffart

    2013-08-01

    Full Text Available Glioblastoma multiforme (GBM, WHO grade IV is the most common and lethal subtype of primary brain tumor with a median overall survival of 15 months from the time of diagnosis. The presence in GBM of a cancer population displaying neural stem cell (NSC properties as well as tumor-initiating abilities and resistance to current therapies suggests that these glioblastoma-initiating cells (GICs play a central role in tumor development and are closely related to NSCs. However, it is nowadays still unclear whether GICs derive from NSCs, neural progenitor cells or differentiated cells such as astrocytes or oligodendrocytes. On the other hand, NSCs are located in specific regions of the adult brain called neurogenic niches that have been shown to control critical stem cell properties, to nourish NSCs and to support their self-renewal. This “seed-and-soil” relationship has also been adapted to cancer stem cell research as GICs also require a specific micro-environment to maintain their “stem cell” properties. In this review, we will discuss the controversies surrounding the origin and the identification of GBM stem cells and highlight the micro-environment impact on their biology.

  17. Anti-proliferative effects of Salacia reticulata leaves hot-water extract on interleukin-1β-activated cells derived from the synovium of rheumatoid arthritis model mice.

    Science.gov (United States)

    Sekiguchi, Yuusuke; Mano, Hiroshi; Nakatani, Sachie; Shimizu, Jun; Kobata, Kenji; Wada, Masahiro

    2012-04-26

    Salacia reticulata (SR) is a plant native to Sri Lanka. In ayurvedic medicine, SR bark preparations, taken orally, are considered effective in the treatment of rheumatism and diabetes. We investigated the ability of SR leaves (SRL) to inhibit in vitro the interleukin-1β (IL-1β)-activated proliferation of synoviocyte-like cells derived from rheumatoid arthritis model mice. Inflammatory synovial tissues were harvested from type II collagen antibody-induced arthritic mice. From these tissues, a synoviocyte-like cell line was established and named MTS-C H7. To determine whether SRL can suppress cell proliferation and gene expression in MTS-C H7 cells, fractionation of the SRL hot-water extract was performed by high-performance liquid chromatography (HPLC), liquid-liquid extraction, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and protease digestion.The 50% inhibitory concentration of the SRL hot-water extract against MTS-C H7 cells proliferation was ~850 μg/mL. Treatment with a low dose (25 μg dry matter per millilitre) of the extract inhibited IL-1β-induced cell proliferation and suppressed the expression of the matrix metalloproteinase (MMP) genes in MTS-C H7 cells. Various polyphenolic fractions obtained from HPLC and the fractions from liquid-liquid extraction did not affect cell proliferation. Only the residual water sample from liquid-liquid extraction significantly affected cell proliferation and the expression of MMP genes. The results of SDS-PAGE and protease digestion experiment showed that low molecular weight proteins present in SRL inhibited the IL-1β-activated cell proliferation. We surmised that the residual water fraction of the SRL extract was involved in the inhibition of IL-1β-activated cell proliferation and regulation of mRNA expression in MTS-C H7 cells. In addition, we believe that the active ingredients in the extract are low molecular weight proteins.

  18. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  19. Fluid mechanics, cell distribution, and environment in CellCube bioreactors.

    Science.gov (United States)

    Auniņs, John G; Bader, Brett; Caola, Anthony; Griffiths, Janet; Katz, Maayan; Licari, Peter; Ram, Kripa; Ranucci, Colette S; Zhou, Weichang

    2003-01-01

    Cultivation of MRC-5 cells and attenuated hepatitis A virus (HAV) for the production of VAQTA, an inactivated HAV vaccine (1), is performed in the CellCube reactor, a laminar flow fixed-bed bioreactor with an unusual diamond-shaped, diverging-converging flow geometry. These disposable bioreactors have found some popularity for the production of cells and gene therapy vectors at intermediate scales of operation (2, 3). Early testing of the CellCube revealed that the fluid mechanical environment played a significant role in nonuniform cell distribution patterns generated during the cell growth phase. Specifically, the reactor geometry and manufacturing artifacts, in combination with certain inoculum practices and circulation flow rates, can create cell growth behavior that is not simply explained. Via experimentation and computational fluid dynamics simulations we can account for practically all of the observed cell growth behavior, which appears to be due to a complex mixture of flow distribution, particle deposition under gravity, fluid shear, and possibly nutritional microenvironment.

  20. A hot water extract of Curcuma longa inhibits adhesion molecule protein expression and monocyte adhesion to TNF-α-stimulated human endothelial cells.

    Science.gov (United States)

    Kawasaki, Kengo; Muroyama, Koutarou; Yamamoto, Norio; Murosaki, Shinji

    2015-01-01

    The recruitment of arterial leukocytes to endothelial cells is an important step in the progression of various inflammatory diseases. Therefore, its modulation is thought to be a prospective target for the prevention or treatment of such diseases. Adhesion molecules on endothelial cells are induced by proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), and contribute to the recruitment of leukocytes. In the present study, we investigated the effect of hot water extract of Curcuma longa (WEC) on the protein expression of adhesion molecules, monocyte adhesion induced by TNF-α in human umbilical vascular endothelial cells (HUVECs). Treatment of HUVECs with WEC significantly suppressed both TNF-α-induced protein expression of adhesion molecules and monocyte adhesion. WEC also suppressed phosphorylation and degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) induced by TNF-α in HUVECs, suggesting that WEC inhibits the NF-κB signaling pathway.

  1. Aerodynamic and acoustic environment of a highly supersonic hot jet; Environnement aerodynamique et acoustique d'un jet chaud et fortement supersonique

    Energy Technology Data Exchange (ETDEWEB)

    Varnier, J.; Gely, D. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), Dept. DSNA, 92 - Chatillon (France); Foulon, H. [CEAT, 86 - Poitiers (France)

    2001-07-01

    In the context of the spatial launchers, the prediction of noise radiated by highly supersonic hot jets is generally made from empirical methods. More recently, simulation methods based on computational fluid dynamics have been developed. In the two cases, in order to specify the parameters of the computer codes, it is necessary to know the actual aerodynamic and acoustic data of the flow. In the MARTEL facilities of CNES, ONERA has carried out tests with a 1200 m/s hot jet, free or impinging on a large plate. Acoustic near field and aerodynamic configuration of the free jet and of the wall jet have been characterized by measurements. Particularly, the supersonic core length and the location of the sound power peak on the jet axis have been determined. Other measurements, made with anemometers and wind cocks in the vicinity of the jet and of the plate, have allowed to characterize the drive of the ambient air by the jet. (authors)

  2. Anti-proliferative effects of Salacia reticulata leaves hot-water extract on interleukin-1β-activated cells derived from the synovium of rheumatoid arthritis model mice

    Directory of Open Access Journals (Sweden)

    Sekiguchi Yuusuke

    2012-04-01

    Full Text Available Abstract Background Salacia reticulata (SR is a plant native to Sri Lanka. In ayurvedic medicine, SR bark preparations, taken orally, are considered effective in the treatment of rheumatism and diabetes. We investigated the ability of SR leaves (SRL to inhibit in vitro the interleukin-1β (IL-1β-activated proliferation of synoviocyte-like cells derived from rheumatoid arthritis model mice. Findings Inflammatory synovial tissues were harvested from type II collagen antibody-induced arthritic mice. From these tissues, a synoviocyte-like cell line was established and named MTS-C H7. To determine whether SRL can suppress cell proliferation and gene expression in MTS-C H7 cells, fractionation of the SRL hot-water extract was performed by high-performance liquid chromatography (HPLC, liquid-liquid extraction, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE, and protease digestion. The 50% inhibitory concentration of the SRL hot-water extract against MTS-C H7 cells proliferation was ~850 μg/mL. Treatment with a low dose (25 μg dry matter per millilitre of the extract inhibited IL-1β-induced cell proliferation and suppressed the expression of the matrix metalloproteinase (MMP genes in MTS-C H7 cells. Various polyphenolic fractions obtained from HPLC and the fractions from liquid-liquid extraction did not affect cell proliferation. Only the residual water sample from liquid-liquid extraction significantly affected cell proliferation and the expression of MMP genes. The results of SDS-PAGE and protease digestion experiment showed that low molecular weight proteins present in SRL inhibited the IL-1β-activated cell proliferation. Conclusions We surmised that the residual water fraction of the SRL extract was involved in the inhibition of IL-1β-activated cell proliferation and regulation of mRNA expression in MTS-C H7 cells. In addition, we believe that the active ingredients in the extract are low molecular weight proteins.

  3. Redox environment in stem and differentiated cells: A quantitative approach

    Directory of Open Access Journals (Sweden)

    O.G. Lyublinskaya

    2017-08-01

    Full Text Available Stem cells are believed to maintain a specific intracellular redox status through a combination of enhanced removal capacity and limited production of ROS. In the present study, we challenge this assumption by developing a quantitative approach for the analysis of the pro- and antioxidant ability of human embryonic stem cells in comparison with their differentiated descendants, as well as adult stem and non-stem cells. Our measurements showed that embryonic stem cells are characterized by low ROS level, low rate of extracellular hydrogen peroxide removal and low threshold for peroxide-induced cytotoxicity. However, biochemical normalization of these parameters to cell volume/protein leads to matching of normalized values in stem and differentiated cells and shows that tested in the present study cells (human embryonic stem cells and their fibroblast-like progenies, adult mesenchymal stem cells, lymphocytes, HeLa maintain similar intracellular redox status. Based on these observations, we propose to use ROS concentration averaged over the cell volume instead of ROS level as a measure of intracellular redox balance. We show that attempts to use ROS level for comparative analysis of redox status of morphologically different cells could lead to false conclusions. Methods for the assessment of ROS concentration based on flow cytometry analysis with the use of H2DCFDA dye and HyPer, genetically encoded probe for hydrogen peroxide, are discussed.

  4. Hot food and beverage consumption and the risk of esophageal squamous cell carcinoma: A case-control study in a northwest area in China.

    Science.gov (United States)

    Tai, Wei-Ping; Nie, Guo-Ji; Chen, Meng-Jie; Yaz, Tajigul Yiminni; Guli, Arzi; Wuxur, Arzigul; Huang, Qing-Qing; Lin, Zhi-Gang; Wu, Jing

    2017-12-01

    This study was trying to investigate the association of hot food and beverage consumption and the risk of esophageal squamous cell carcinoma in Hotan, a northwest area of China with high risk of esophageal squmous cell carcinoma. A population-based case-control study was designed. For the study, 167 patients diagnosed with esophageal squamous cell carcinoma were selected from Hotan during 2014 to 2015, and 167 community-based controls were selected from the same area, matched with age and sex. Information involved of temperature of food and beverage intake was obtained by face-to-face interview. Logistic regression analyses were performed to investigate the association between temperature of food and beverage intake and the risk of esophageal squamous cell carcinoma. The temperature of the food and beverage consumed by the esophageal squamous cell carcinoma patients was significantly higher than the controls. High temperature of tea, water, and food intake significantly increased the risk of esophageal squamous cell carcinoma by more than 2-fold, with adjusted odds ratio 2.23 (1.45-2.90), 2.13 (1.53-2.66), and 2.98 (1.89-4.12). Intake of food and beverage with high temperature was positively associated with the incidence of esophageal squamous cell carcinoma in Northwestern China. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  5. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  6. Study of structural and electronic environments of hydrogenated amorphous silicon carbonitride (a-SiCN:H) films deposited by hot wire chemical vapor deposition

    Science.gov (United States)

    Swain, Bibhu P.; Hwang, Nong M.

    2008-06-01

    Hydrogenated amorphous silicon carbon nitride (a-SiCN:H) thin films were deposited by hot wire chemical vapor deposition (HWCVD) using SiH 4, CH 4, NH 3 and H 2 as precursors. The effects of the H 2 dilution on structural and chemical bonding of a-SiCN:H has been investigated by Raman and X-ray photoelectron spectroscopy (XPS). Increasing the H 2 flow rate in the precursor gas more carbon is introduced into the a-SiCN:H network resulting in decrease of silicon content in the film from 41 at.% to 28.8 at.% and sp 2 carbon cluster increases when H 2 flow rate is increased from 0 to 20 sccm.

  7. Study of structural and electronic environments of hydrogenated amorphous silicon carbonitride (a-SiCN:H) films deposited by hot wire chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Swain, Bibhu P. [National Research Laboratory of Charged Nanoparticles, School of Materials Science and Engineering, Seoul National University, Seoul (Korea, Republic of)], E-mail: swain@snu.ac.kr; Hwang, Nong M. [National Research Laboratory of Charged Nanoparticles, School of Materials Science and Engineering, Seoul National University, Seoul (Korea, Republic of)

    2008-06-30

    Hydrogenated amorphous silicon carbon nitride (a-SiCN:H) thin films were deposited by hot wire chemical vapor deposition (HWCVD) using SiH{sub 4}, CH{sub 4}, NH{sub 3} and H{sub 2} as precursors. The effects of the H{sub 2} dilution on structural and chemical bonding of a-SiCN:H has been investigated by Raman and X-ray photoelectron spectroscopy (XPS). Increasing the H{sub 2} flow rate in the precursor gas more carbon is introduced into the a-SiCN:H network resulting in decrease of silicon content in the film from 41 at.% to 28.8 at.% and sp{sup 2} carbon cluster increases when H{sub 2} flow rate is increased from 0 to 20 sccm.

  8. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  9. β-Adrenergic blockade does not impair the skin blood flow sensitivity to local heating in burned and nonburned skin under neutral and hot environments in children.

    Science.gov (United States)

    Rivas, Eric; McEntire, Serina J; Herndon, David N; Mlcak, Ronald P; Suman, Oscar E

    2017-05-01

    We tested the hypothesis that propranolol, a drug given to burn patients to reduce hypermetabolism/cardiac stress, may inhibit heat dissipation by changing the sensitivity of skin blood flow (SkBF) to local heating under neutral and hot conditions. In a randomized double-blind study, a placebo was given to eight burned children, while propranolol was given to 13 burned children with similar characteristics (mean±SD: 11.9±3 years, 147±20 cm, 45±23 kg, 56±12% Total body surface area burned). Nonburned children (n=13, 11.4±3 years, 152±15 cm, 52±13 kg) served as healthy controls. A progressive local heating protocol characterized SkBF responses in burned and unburned skin and nonburned control skin under the two environmental conditions (23 and 34°C) via laser Doppler flowmetry. Resting SkBF was greater in burned and unburned skin compared to the nonburned control (main effect: skin, Pburned; 38±36 unburned vs 9±8 control %SkBFmax ). No difference was found for maximal SkBF capacity to local heating between groups. Additionally, dose-response curves for the sensitivity of SkBF to local heating were not different among burned or unburned skin, and nonburned control skin (EC50 , P>.05) under either condition. Therapeutic propranolol does not negatively affect SkBF under neutral or hot environmental conditions and further compromise temperature regulation in burned children. © 2017 John Wiley & Sons Ltd.

  10. Stability of artemisinin in aqueous environments : Impact on its cytotoxic action to Ehrlich ascites tumour cells

    NARCIS (Netherlands)

    Beekman, A.C; Woerdenbag, H.J.; van Uden, W; Pras, N.; Konings, A.WT; Wikström, H.V

    1997-01-01

    We have recently shown artemisinin to be cytotoxic against Ehrlich ascites tumour cells. The aim of this study was to investigate the stability of this compound in the aqueous environment of the in-vitro Ehrlich ascites tumour cell system (RPMI 1640 cell culture medium supplemented with 10% foetal

  11. Student Perceptions of the Cell Biology Laboratory Learning Environment in Four Undergraduate Science Courses in Spain

    Science.gov (United States)

    De Juan, Joaquin; Pérez-Cañaveras, Rosa M.; Segovia, Yolanda; Girela, Jose Luis; Martínez-Ruiz, Noemi; Romero-Rameta, Alejandro; Gómez-Torres, Maria José; Vizcaya-Moreno, M. Flores

    2016-01-01

    Cell biology is an academic discipline that organises and coordinates the learning of the structure, function and molecular composition of cells in some undergraduate biomedical programs. Besides course content and teaching methodologies, the laboratory environment is considered a key element in the teaching of and learning of cell biology. The…

  12. Oxidized alginate hydrogels as niche environments for corneal epithelial cells

    Science.gov (United States)

    Wright, Bernice; De Bank, Paul A; Luetchford, Kim A; Acosta, Fernando R; Connon, Che J

    2014-01-01

    Chemical and biochemical modification of hydrogels is one strategy to create physiological constructs that maintain cell function. The aim of this study was to apply oxidised alginate hydrogels as a basis for development of a biomimetic niche for limbal epithelial stem cells that may be applied to treating corneal dysfunction. The stem phenotype of bovine limbal epithelial cells (LEC) and the viability of corneal epithelial cells (CEC) were examined in oxidised alginate gels containing collagen IV over a 3-day culture period. Oxidation increased cell viability (P ≤ 0.05) and this improved further with addition of collagen IV (P ≤ 0.01). Oxidised gels presented larger internal pores (diameter: 0.2–0.8 µm) than unmodified gels (pore diameter: 0.05–0.1 µm) and were significantly less stiff (P ≤ 0.001), indicating that an increase in pore size and a decrease in stiffness contributed to improved cell viability. The diffusion of collagen IV from oxidised alginate gels was similar to that of unmodified gels suggesting that oxidation may not affect the retention of extracellular matrix proteins in alginate gels. These data demonstrate that oxidised alginate gels containing corneal extracellular matrix proteins can influence corneal epithelial cell function in a manner that may impact beneficially on corneal wound healing therapy. © 2013 The Authors. Journal of Biomedical Materials Research Part A Published byWiley Periodicals, Inc. Part A: 102A: 3393–3400, 2014. PMID:24142706

  13. Nanoarchaeota, Their Sulfolobales Host, and Nanoarchaeota Virus Distribution across Yellowstone National Park Hot Springs.

    Science.gov (United States)

    Munson-McGee, Jacob H; Field, Erin K; Bateson, Mary; Rooney, Colleen; Stepanauskas, Ramunas; Young, Mark J

    2015-11-01

    Nanoarchaeota are obligate symbionts with reduced genomes first described from marine thermal vent environments. Here, both community metagenomics and single-cell analysis revealed the presence of Nanoarchaeota in high-temperature (∼90°C), acidic (pH ≈ 2.5 to 3.0) hot springs in Yellowstone National Park (YNP) (United States). Single-cell genome analysis of two cells resulted in two nearly identical genomes, with an estimated full length of 650 kbp. Genome comparison showed that these two cells are more closely related to the recently proposed Nanobsidianus stetteri from a more neutral YNP hot spring than to the marine Nanoarchaeum equitans. Single-cell and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) analysis of environmental hot spring samples identified the host of the YNP Nanoarchaeota as a Sulfolobales species known to inhabit the hot springs. Furthermore, we demonstrate that Nanoarchaeota are widespread in acidic to near neutral hot springs in YNP. An integrated viral sequence was also found within one Nanoarchaeota single-cell genome and further analysis of the purified viral fraction from environmental samples indicates that this is likely a virus replicating within the YNP Nanoarchaeota. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Identification of the hot-spot areas for sickle cell disease using cord blood screening at a district hospital: an Indian perspective.

    Science.gov (United States)

    Dixit, Sujata; Sahu, Pushpansu; Kar, Shantanu Kumar; Negi, Sapna

    2015-10-01

    Sickle cell disease (SCD), a genetic disorder often reported late, can be identified early in life, and hot-spot areas may be identified to conduct genetic epidemiology studies. This study was undertaken to estimate prevalence and to identify hot spot area for SCD in Kalahandi district, by screening cord blood of neonates delivered at the district hospital as first-hand information. Kalahandi District Hospital selected for the study is predominated by tribal population with higher prevalence of SCD as compared to other parts of Odisha. Cord blood screening of SCD was carried out on 761 newborn samples of which 13 were screened to be homozygous for SCD. Information on area of parent's residence was also collected. Madanpur Rampur area was found to be with the highest prevalence of SCD (10.52 %) and the gene distribution did not follow Hardy-Weinberg Equation indicating un-natural selection. The approach of conducting neonatal screening in a district hospital for identification of SCD is feasible and appropriate for prioritizing area for the implementation of large-scale screening and planning control measures thereof.

  15. Mechanically dynamic PDMS substrates to investigate changing cell environments.

    Science.gov (United States)

    Yeh, Yi-Cheun; Corbin, Elise A; Caliari, Steven R; Ouyang, Liu; Vega, Sebastián L; Truitt, Rachel; Han, Lin; Margulies, Kenneth B; Burdick, Jason A

    2017-11-01

    Mechanics of the extracellular matrix (ECM) play a pivotal role in governing cell behavior, such as cell spreading and differentiation. ECM mechanics have been recapitulated primarily in elastic hydrogels, including with dynamic properties to mimic complex behaviors (e.g., fibrosis); however, these dynamic hydrogels fail to introduce the viscoelastic nature of many tissues. Here, we developed a two-step crosslinking strategy to first form (via platinum-catalyzed crosslinking) networks of polydimethylsiloxane (PDMS) and then to increase PDMS crosslinking (via thiol-ene click reaction) in a temporally-controlled manner. This photoinitiated reaction increased the compressive modulus of PDMS up to 10-fold within minutes and was conducted under cytocompatible conditions. With stiffening, cells displayed increased spreading, changing from ∼1300 to 1900 μm(2) and from ∼2700 to 4600 μm(2) for fibroblasts and mesenchymal stem cells, respectively. In addition, higher myofibroblast activation (from ∼2 to 20%) for cardiac fibroblasts was observed with increasing PDMS substrate stiffness. These results indicate a cellular response to changes in PDMS substrate mechanics, along with a demonstration of a mechanically dynamic and photoresponsive PDMS substrate platform to model the dynamic behavior of ECM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Investigation of the basic physics of high efficiency semiconductor hot carrier solar cell. Annual status report, 31 May 1994-30 May 1995

    Energy Technology Data Exchange (ETDEWEB)

    Alfano, R.R.; Wang, W.B.; Mohaidat, J.M.; Cavicchia, M.A.; Raisky, O.Y.

    1995-05-01

    The main purpose of this research program is to investigate potential semiconductor materials and their multi-band-gap MQW (multiple quantum wells) structures for high efficiency solar cells for aerospace and commercial applications. The absorption and PL (photoluminescence) spectra, the carrier dynamics, and band structures have been investigated for semiconductors of InP, GaP, GaInP, and InGaAsP/InP MQW structures, and for semiconductors of GaAs and AlGaAs by previous measurements. The barrier potential design criteria for achieving maximum energy conversion efficiency, and the resonant tunneling time as a function of barrier width in high efficiency MQW solar cell structures have also been investigated in the first two years. Based on previous carrier dynamics measurements and the time-dependent short circuit current density calculations, an InAs/InGaAs - InGaAs/GaAs - GaAs/AlGaAs MQW solar cell structure with 15 bandgaps has been designed. The absorption and PL spectra in InGaAsP/InP bulk and MQW structures were measured at room temperature and 77 K with different pump wavelength and intensity, to search for resonant states that may affect the solar cell activities. Time-resolved IR absorption for InGaAsP/InP bulk and MQW structures has been measured by femtosecond visible-pump and IR-probe absorption spectroscopy. This, with the absorption and PL measurements, will be helpful to understand the basic physics and device performance in multi-bandgap InAs/InGaAs - InGaAs/InP - InP/InGaP MQW solar cells. In particular, the lifetime of the photoexcited hot electrons is an important parameter for the device operation of InGaAsP/InP MQW solar cells working in the resonant tunneling conditions. Lastly, time evolution of the hot electron relaxation in GaAs has been measured in the temperature range of 4 K through 288 K using femtosecond pump-IR-probe absorption technique.

  17. Hot air treatment reduces postharvest decay and delays softening of cherry tomato by regulating gene expression and activities of cell wall-degrading enzymes.

    Science.gov (United States)

    Wei, Yingying; Zhou, Dandan; Wang, Zhenjie; Tu, Sicong; Shao, Xingfeng; Peng, Jing; Pan, Leiqing; Tu, Kang

    2017-09-25

    Fruit softening facilitates pathogen infection and postharvest decay, leading to the reduction of shelf-life. Hot air (HA) treatment at 38 °C for 12 h is effective in reducing postharvest disease and chilling injury of tomato fruit. To explore the effect and mechanism of HA treatment on reducing postharvest decay and softening of cherry tomato, fruit at the mature green stage were treated with HA and then stored at 20 °C for 15 days. Changes in natural decay incidence, firmness, cell wall compositions, activities and gene expression of cell wall-degrading enzymes of cherry tomatoes were assessed. HA treatment reduced natural decay incidence, postponed the firmness decline, inhibited the respiration rate and ethylene production, and retarded pectin solubilization and cellulose degradation of cherry tomatoes. Enzymatic activities and gene expression of pectin methylesterase, polygalacturonase, cellulase and β-galactosidase were inhibited by HA treatment. In addition, the gene expression of LeEXP1 was reduced, while LeEXT was up-regulated after HA treatment. Our findings suggested that HA treatment could inhibit cell wall degradation and postpone softening of cherry tomatoes by regulating gene expression and activities of cell wall-degrading enzymes, resulting in the reduction of postharvest decay. This article is protected by copyright. All rights reserved.

  18. TRUEX hot demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlain, D.B.; Leonard, R.A.; Hoh, J.C.; Gay, E.C.; Kalina, D.G.; Vandegrift, G.F.

    1990-04-01

    In FY 1987, a program was initiated to demonstrate technology for recovering transuranic (TRU) elements from defense wastes. This hot demonstration was to be carried out with solution from the dissolution of irradiated fuels. This recovery would be accomplished with both PUREX and TRUEX solvent extraction processes. Work planned for this program included preparation of a shielded-cell facility for the receipt and storage of spent fuel from commercial power reactors, dissolution of this fuel, operation of a PUREX process to produce specific feeds for the TRUEX process, operation of a TRUEX process to remove residual actinide elements from PUREX process raffinates, and processing and disposal of waste and product streams. This report documents the work completed in planning and starting up this program. It is meant to serve as a guide for anyone planning similar demonstrations of TRUEX or other solvent extraction processing in a shielded-cell facility.

  19. Not so nuanced: Reply to the comments of Gaskill and Garner on 'Not so hot: Optimal housing temperatures for mice to mimic the environment of humans'

    NARCIS (Netherlands)

    Speakman, J.; Keijer, J.

    2014-01-01

    Under a Creative Commons license Dear Editors, We welcome the comments of Gaskill and Garner [1] on our previous paper, which concerned the optimal temperatures at which mice should be housed to best mimic the ambient environment routinely experienced by humans [2]. We are glad that they agree, from

  20. A Mathematical Model of Collective Cell Migration in a Three-Dimensional, Heterogeneous Environment

    Science.gov (United States)

    Stonko, David P.; Manning, Lathiena; Starz-Gaiano, Michelle; Peercy, Bradford E.

    2015-01-01

    Cell migration is essential in animal development, homeostasis, and disease progression, but many questions remain unanswered about how this process is controlled. While many kinds of individual cell movements have been characterized, less effort has been directed towards understanding how clusters of cells migrate collectively through heterogeneous, cellular environments. To explore this, we have focused on the migration of the border cells during Drosophila egg development. In this case, a cluster of different cell types coalesce and traverse as a group between large cells, called nurse cells, in the center of the egg chamber. We have developed a new model for this collective cell migration based on the forces of adhesion, repulsion, migration and stochastic fluctuation to generate the movement of discrete cells. We implement the model using Identical Math Cells, or IMCs. IMCs can each represent one biological cell of the system, or can be aggregated using increased adhesion forces to model the dynamics of larger biological cells. The domain of interest is filled with IMCs, each assigned specific biophysical properties to mimic a diversity of cell types. Using this system, we have successfully simulated the migration of the border cell cluster through an environment filled with larger cells, which represent nurse cells. Interestingly, our simulations suggest that the forces utilized in this model are sufficient to produce behaviors of the cluster that are observed in vivo, such as rotation. Our framework was developed to capture a heterogeneous cell population, and our implementation strategy allows for diverse, but precise, initial position specification over a three- dimensional domain. Therefore, we believe that this model will be useful for not only examining aspects of Drosophila oogenesis, but also for modeling other two or three-dimensional systems that have multiple cell types and where investigating the forces between cells is of interest. PMID:25875645

  1. A mathematical model of collective cell migration in a three-dimensional, heterogeneous environment.

    Directory of Open Access Journals (Sweden)

    David P Stonko

    Full Text Available Cell migration is essential in animal development, homeostasis, and disease progression, but many questions remain unanswered about how this process is controlled. While many kinds of individual cell movements have been characterized, less effort has been directed towards understanding how clusters of cells migrate collectively through heterogeneous, cellular environments. To explore this, we have focused on the migration of the border cells during Drosophila egg development. In this case, a cluster of different cell types coalesce and traverse as a group between large cells, called nurse cells, in the center of the egg chamber. We have developed a new model for this collective cell migration based on the forces of adhesion, repulsion, migration and stochastic fluctuation to generate the movement of discrete cells. We implement the model using Identical Math Cells, or IMCs. IMCs can each represent one biological cell of the system, or can be aggregated using increased adhesion forces to model the dynamics of larger biological cells. The domain of interest is filled with IMCs, each assigned specific biophysical properties to mimic a diversity of cell types. Using this system, we have successfully simulated the migration of the border cell cluster through an environment filled with larger cells, which represent nurse cells. Interestingly, our simulations suggest that the forces utilized in this model are sufficient to produce behaviors of the cluster that are observed in vivo, such as rotation. Our framework was developed to capture a heterogeneous cell population, and our implementation strategy allows for diverse, but precise, initial position specification over a three- dimensional domain. Therefore, we believe that this model will be useful for not only examining aspects of Drosophila oogenesis, but also for modeling other two or three-dimensional systems that have multiple cell types and where investigating the forces between cells is of

  2. Effects of Precooling with Cold Water Ingestion on Thermoregulatory Response of Obese Men during Moderate Intensity Exercise in Hot and Humid Environment.

    Science.gov (United States)

    Tasing, Piyachate; Kulaputana, Onanong; Sanguanrungsirikul, Sompol; Kaikaew, Kasiphak

    2016-02-01

    1) To determine rectal temperature (Tre) and fluid loss (FL) of obese men (OM) compared to non-obese men (NM) during exercise in cool conditions (CC) and hot and humid conditions (HC), and 2) to investigate the effects of cold water (CW; 0.5 ± 0.5°C) ingestion before exercise in HC in OM MATERIAL AND METHOD: Twelve OM and 12 NM completed 2 treadmill exercise sessions, in CC and HC, in a randomized order Each session was performed for 30 minutes at 45-50% of heart rate reserve with a 5-minute warm up and 5-minute cool down. There were no differences in Tre in response to exercise between OM and NM both in CC (OM 37.77 ± 0.08°C, NM 37.68 ± 0.08°C; p = 0.463) and in HC (OM 37.82 ± 0.06°C, NM 37.85 ± 0.06°C; p = 0.725). Heart rate, perceived exertion and thermal sensations were not significantly different between OM and NM. However, compared to NM, fluid loss (FL) was approximately 160 mL greater in OM (OM 443.33 ± 98.65 mL, NM 283.33 ± 108.15 mL; p ≤ 0.001) in CC, and was 194 mL greater (OM 632.50 ± 126.57 mL, NM 438.33 ± 126.62 mL; p ≤ 0.001) in HC. In HC, the 12 OM performed additional 2 bouts of exercise, with CW vs. ambient temperature water (AW; 30.5 ± 0.5°C) ingestions prior to the start of exercise. Precooling with CW ingestion, compared to AW ingestion, showed no significant difference in Tre but CW was able to reduce FL (CW 646.67 ± 139.82 mL, AW 735 ± 126.95 mL; p = 0.010). OM may continuously exercise about 30 minutes at moderate intensity in HC without the increase of Tre to dangerous levels. However, OM should drink approximately 200 mL more water in HC and 160 mL more water in CC than NM. Precooling with CW ingestion is a good method of reducing risk of exertional heat illnesses in obese individuals during exercise in HC, as it decreases the amount of FL induced by exercise.

  3. In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments.

    Science.gov (United States)

    Marsh, Leigh; Copley, Jonathan T; Tyler, Paul A; Thatje, Sven

    2015-07-01

    Few species of reptant decapod crustaceans thrive in the cold-stenothermal waters of the Southern Ocean. However, abundant populations of a new species of anomuran crab, Kiwa tyleri, occur at hydrothermal vent fields on the East Scotia Ridge. As a result of local thermal conditions at the vents, these crabs are not restricted by the physiological limits that otherwise exclude reptant decapods south of the polar front. We reveal the adult life history of this species by piecing together variation in microdistribution, body size frequency, sex ratio, and ovarian and embryonic development, which indicates a pattern in the distribution of female Kiwaidae in relation to their reproductive development. High-density 'Kiwa' assemblages observed in close proximity to sources of vent fluids are constrained by the thermal limit of elevated temperatures and the availability of resources for chemosynthetic nutrition. Although adult Kiwaidae depend on epibiotic chemosynthetic bacteria for nutrition, females move offsite after extrusion of their eggs to protect brooding embryos from the chemically harsh, thermally fluctuating vent environment. Consequently, brooding females in the periphery of the vent field are in turn restricted by low-temperature physiological boundaries of the deep-water Southern Ocean environment. Females have a high reproductive investment in few, large, yolky eggs, facilitating full lecithotrophy, with the release of larvae prolonged, and asynchronous. After embryos are released, larvae are reliant on locating isolated active areas of hydrothermal flow in order to settle and survive as chemosynthetic adults. Where the cold water restricts the ability of all adult stages to migrate over long distances, these low temperatures may facilitate the larvae in the location of vent sites by extending the larval development period through hypometabolism. These differential life-history adaptations to contrasting thermal environments lead to a disjunct life history

  4. Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

    Science.gov (United States)

    2013-01-01

    Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74) and control (CON, n = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (p  0.05 vs. CON pre-stage). Asymptomatic hyponatraemia (runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations. PMID:23320854

  5. Evaluating the behaviour of different thermal indices by investigating various outdoor urban environments in the hot dry city of Damascus, Syria.

    Science.gov (United States)

    Yahia, Moohammed Wasim; Johansson, Erik

    2013-07-01

    Consideration of urban microclimate and thermal comfort is an absolute neccessity in urban development, and a set of guidelines for every type of climate must be elaborated. However, to develop guidelines, thermal comfort ranges need to be defined. The aim of this study was to evaluate the behaviour of different thermal indices by investigating different thermal environments in Damascus during summer and winter. A second aim was to define the lower and upper limits of the thermal comfort range for some of these indices. The study was based on comprehensive micrometeorological measurements combined with questionnaires. It was found that the thermal conditions of different outdoor environments vary considerably. In general, Old Damascus, with its deep canyons, is more comfortable in summer than modern Damascus where there is a lack of shade. Conversely, residential areas and parks in modern Damascus are more comfortable in winter due to more solar access. The neutral temperatures of both the physiologically equivalent temperature (PET) and the outdoor standard effective temperature (OUT_SET*) were found to be lower in summer than in winter. At 80 % acceptability, the study defined the lower comfort limit in winter to 21.0 °C and the upper limit in summer to 31.3 °C for PET. For OUT_SET*, the corresponding lower and upper limits were 27.6 °C and 31.3 °C respectively. OUT_SET* showed a better correlation with the thermal sensation votes than PET. The study also highlighted the influence of culture and traditions on people's clothing as well as the influence of air conditioning on physical adaptation.

  6. The aged nonhematopoietic environment impairs natural killer cell maturation and function

    Science.gov (United States)

    Shehata, Hesham M; Hoebe, Kasper; Chougnet, Claire A

    2015-01-01

    Natural killer (NK) cells are critical in eliminating tumors and viral infections, both of which occur at a high incidence in the elderly. Previous studies showed that aged NK cells are less cytotoxic and exhibit impaired maturation compared to young NK cells. We evaluated whether extrinsic or intrinsic factors were responsible for the impaired maturation and function of NK cells in aging and whether impaired maturation correlated with functional hyporesponsiveness. We confirmed that aged mice have a significant decrease in the frequency of mature NK cells in all lymphoid organs. Impaired NK cell maturation in aged mice correlated with a reduced capacity to eliminate allogeneic and B16 tumor targets in vivo. This could be explained by impaired degranulation, particularly by mature NK cells of aged mice. Consistent with impaired aged NK cell maturation, expression of T-bet and Eomes, which regulate NK cell functional maturation, was significantly decreased in aged bone marrow (BM) NK cells. Mixed BM chimeras revealed that the nonhematopoietic environment was a key determinant of NK cell maturation and T-bet and Eomes expression. In mixed BM chimeras, NK cells derived from both young or aged BM cells adopted an ‘aged’ phenotype in an aged host, that is, were hyporesponsive to stimuli in vitro, while adopting a ‘young’ phenotype following transfer in young hosts. Overall, our data suggest that the aged nonhematopoietic environment is responsible for the impaired maturation and function of NK cells. Defining these nonhematopoietic factors could have important implications for improving NK cell function in the elderly. PMID:25677698

  7. The seed and the soil: optimizing stem cells and their environment for tissue regeneration.

    Science.gov (United States)

    Hyun, Jeong S; Montoro, Daniel T; Lo, David D; Flynn, Ryan A; Wong, Victor; Chung, Michael Thomas; Longaker, Michael T; Wan, Derrick C

    2013-02-01

    The potential for stem cells to serve as cellular building blocks for reconstruction of complex defects has prompted significant enthusiasm in the field of regenerative medicine. Clinical application, however, is still limited, as implantation of cells into hostile wound environments may greatly hinder their tissue forming capacity. To circumvent this obstacle, novel approaches have been developed to manipulate both the stem cell itself and its surrounding environmental niche. By understanding this paradigm of seed and soil optimization, innovative strategies may thus be developed to harness the true promise of stem cells for tissue regeneration.

  8. Cell-host, LINE and environment: Three players in search of a balance.

    Science.gov (United States)

    Del Re, Brunella; Giorgi, Gianfranco

    2013-01-01

    Long interspersed nuclear elements -1 (LINEs, L1s) are retroelements occupying almost 17% of the human genome. L1 retrotransposition can cause deleterious effects on the host-cell and it is generally inhibited by suppressive mechanisms, but it can occur in some specific cells during early development as well as in some tumor cells and in the presence of several environmental factors. In a recent publication we reported that extremely low frequency pulsed magnetic field can affect L1 retrotransposition in neuroblastoma cells. In this commentary we discuss the interaction between environment and L1 activity in the light of the new emerging paradigm of host-LINE relationship.

  9. Applying hot wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell - Part 1

    DEFF Research Database (Denmark)

    Berning, Torsten; Al Shakhshir, Saher

    2015-01-01

    In order to accurately determine the water balance of a proton exchange membrane fuel cell it has recently been suggested to employ constant temperature anemometry (CTA), a frequently used method to measure the velocity of a fluid stream. CTA relies on convective heat transfer around a heated wire...... the equations required to calculate the heat transfer coefficient and the resulting voltage signal as function of the fuel cell water balance. The most critical and least understood part is the determination of the Nusselt number to calculate the heat transfer between the wire and the gas stream. Different...... for all current densities. Therefore, only one curve-fit equation will be required. The voltage curve E0 is an arbitrary calibration curve, and this can be conveniently chosen to be the voltage signal for a dry hydrogen stream at a given temperature and various flow rates which can be easily measured....

  10. Patterns of DNA damage response in intracranial germ cell tumors versus glioblastomas reflect cell of origin rather than brain environment

    DEFF Research Database (Denmark)

    Bartkova, Jirina; Hoei-Hansen, Christina E; Krizova, Katerina

    2014-01-01

    The DNA damage response (DDR) machinery becomes commonly activated in response to oncogenes and during early stages of development of solid malignancies, with an exception of testicular germ cell tumors (TGCTs). The active DDR signaling evokes cell death or senescence but this anti-tumor barrier...... cell tumors (PIGCTs), to address the roles of cell-intrinsic factors including cell of origin, versus local tissue environment, in the constitutive DDR activation in vivo. Immunohistochemical analysis of 7 biomarkers on a series of 21 PIGCTs (germinomas and other subtypes), 20 normal brain specimens......, there were no clear aberrations in the ATM-Chk2-p53 pathway components among the PIGCT cohort; iii) Subsets of PIGCTs showed unusual cytosolic localization of Chk2 and/or ATM. Collectively, these results show that PIGCTs mimic the DDR activation patterns of their gonadal germ cell tumor counterparts, rather...

  11. Enriched environment induces higher CNPase positive cells in aged rat hippocampus.

    Science.gov (United States)

    Zhao, Yuan-Yu; Shi, Xiao-Yan; Zhang, Lei; Wu, Hong; Chao, Feng-Lei; Huang, Chun-Xia; Gao, Yuan; Qiu, Xuan; Chen, Lin; Lu, Wei; Tang, Yong

    2013-10-25

    It had been reported that enriched environment was beneficial for the brain cognition and for the neurons and synapses in hippocampus. Previous study reported that the oligodendrocyte density in hippocampus was increased when the rats were reared in the enriched environment from weaning to adulthood. However, biological conclusions based on density were difficult to interpret because the changes in density could be due to an alteration of total quantity and/or an alteration in the reference volume. In the present study, we used unbiased stereological methods to investigate the effect of enriched environment on the total number of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) positive cells in CA1 and dentate gyrus (DG) of the hippocampus in aged rats. Our results indicated that there was significant difference in the total numbers of CNPase positive cells in both CA1 and DG between enriched environment group and standard environment group. The present study provided the first evidence for the protective effects of enriched environment on the CNPase positive cells in aged hippocampus. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Surface enhanced Raman spectroscopy measurements of MCF7 cells adhesion in confined micro-environments

    KAUST Repository

    De Vitis, Stefania

    2015-05-01

    Undoubtedly cells can perceive the external environment, not only from a biochemical point of view with the related signalling pathways, but also from a physical and topographical perspective. In this sense controlled three dimensional micro-structures as well as patterns at the nano-scale can affect and guide the cell evolution and proliferation, due to the fact that the surrounding environment is no longer isotropic (like the flat surfaces of standard cell culturing) but possesses well defined symmetries and anisotropies. In this work regular arrays of silicon micro-pillars with hexagonal arrangement are used as culturing substrates for MCF-7 breast cancer cells. The characteristic size and spacing of the pillars are tens of microns, comparable with MCF-7 cell dimensions and then well suited to induce acceptable external stimuli. It is shown that these cells strongly modify their morphology for adapting themselves to the micro-structured landscape, by means of protrusions from the main body of the cell. Scanning electron microscopy along with both Raman micro-spectroscopy and surface enhanced Raman spectroscopy are used for topographical and biochemical studies of the new cell arrangement. We have revealed that single MCF-7 cells exploit their capability to produce invadopodia, usually generated to invade the neighboring tissue in metastatic activity, for spanning and growing across separate pillars. © 2015 Elsevier Ltd.

  13. The effect of the muscle environment on the regenerative capacity of human skeletal muscle stem cells.

    Science.gov (United States)

    Meng, Jinhong; Bencze, Maximilien; Asfahani, Rowan; Muntoni, Francesco; Morgan, Jennifer E

    2015-01-01

    Muscle stem cell transplantation is a possible treatment for muscular dystrophy. In addition to the intrinsic properties of the stem cells, the local and systemic environment plays an important role in determining the fate of the grafted cells. We therefore investigated the effect of modulating the host muscle environment in different ways (irradiation or cryoinjury or a combination of irradiation and cryoinjury) in two immunodeficient mouse strains (mdx nude and recombinase-activating gene (Rag)2-/γ chain-/C5-) on the regenerative capacity of two types of human skeletal muscle-derived stem cell (pericytes and CD133+ cells). Human skeletal muscle-derived pericytes or CD133+ cells were transplanted into muscles of either mdx nude or recombinase-activating gene (Rag)2-/γ chain-/C5- host mice. Host muscles were modulated prior to donor cell transplantation by either irradiation, or cryoinjury, or a combination of irradiation and cryoinjury. Muscles were analysed four weeks after transplantation, by staining transverse cryostat sections of grafted muscles with antibodies to human lamin A/C, human spectrin, laminin and Pax 7. The number of nuclei and muscle fibres of donor origin and the number of satellite cells of both host and donor origin were quantified. Within both host strains transplanted intra-muscularly with both donor cell types, there were significantly more nuclei and muscle fibres of donor origin in host muscles that had been modulated by cryoinjury, or irradiation+cryoinjury, than by irradiation alone. Irradiation has no additive effects in further enhancing the transplantation efficiency than cryodamage. Donor pericytes did not give rise to satellite cells. However, using CD133+ cells as donor cells, there were significantly more nuclei, muscle fibres, as well as satellite cells of donor origin in Rag2-/γ chain-/C5- mice than mdx nude mice, when the muscles were injured by either cryodamage or irradiation+cryodamage. Rag2-/γ chain-/C5- mice are a

  14. Impact of enriched environment on murine T cell differentiation and gene expression profile

    Directory of Open Access Journals (Sweden)

    Lorenza Rattazzi

    2016-09-01

    Full Text Available T cells are known to be plastic and to change their phenotype according to the cellular and biochemical milieu they are embedded in. In this study we transposed this concept at a macroscopic level assessing whether changes in the environmental housing conditions of C57/BL6 mice would influence the phenotype and function of T cells. Our study shows that exposure to two weeks in an enriched environment does not impact the T cell repertoire in vivo and causes no changes in the early TCR-driven activation events of these cells. Surprisingly, however, T cells from enriched mice showed a unique T helper effector-cell phenotype upon differentiation in vitro. This was featured by a significant reduction in their ability to produce IFN-γ and by an increased release of IL-10 and IL-17. Microarray analysis of these cells also revealed a unique gene fingerprint with key signaling pathways involved in autoimmunity being modulated. Together our results provide first evidence for a specific effect of enriched environment on T cell differentiation and its associated changes in gene expression profile. In addition, our study sheds new light on the possible mechanisms by which changes in environmental factors can significantly influence the immune response of the host and favor the resolution of the inflammatory response.

  15. Pro-inflammatory effector Th cells transmigrate through anti-inflammatory environments into the murine fetus.

    Science.gov (United States)

    Wienecke, J; Hebel, K; Hegel, K J; Pierau, M; Brune, T; Reinhold, D; Pethe, A; Brunner-Weinzierl, M C

    2012-01-01

    The presence of maternal DNA or even maternal cells within the offspring (microchimerism) has been reported for many fetal tissues, including the liver, heart, and spleen. Microchimerism is believed to be involved in the pathogenesis of autoimmune diseases; however, the cellular origin of this phenomenon remains unknown. Here, we determined whether differentiated T lymphocytes could transmigrate through the immunosuppressive environment of the placenta to reach the fetus. In vitro-differentiated effector/memory Th1 and Th17 cells from OVA₃₂₃₋₃₃₉-specific TCR(tg) T cells of OT-II mice were adoptively transferred (i.v.) into the tail veins of pregnant Ly5.1 mice at d15 and d19 of gestation. Mice were then sacrificed 40 h after adoptive cell transfer. Using radioactive labeling of T cells with sodium chromate [Cr⁵¹] prior to adoptive transfer, we observed that homing of pro-inflammatory Th cells was equally efficient in both pregnant and non-pregnant mice. Transmigration of Th1- and Th17-like cells through the highly immunosuppressive environment of the placenta into the fetus was significantly enhanced in experimental mice compared to control mice (P cells accumulated in the placenta. Finally, we found that treatment with Pertussis Toxin resulted in a 3-fold increase in the transmigration of effector Th17 cells into the fetus (P cells were injected into syngeneic mothers, almost all of the fetuses analyzed exhibited radioactivity, suggesting that transmigration of effector T cells occurs frequently. Our results suggest the possibility of novel roles for these maternal effector cells in the pathogenesis or reduction of disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment

    Science.gov (United States)

    Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

    2016-06-01

    The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased ( P muscle at 28, 35, and 42 days, while it increased ( P muscle, the Gln supplementation increased ( P muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.

  17. The effect of fibrillar matrix architecture on tumor cell invasion of physically challenging environments.

    Science.gov (United States)

    Guzman, Asja; Ziperstein, Michelle J; Kaufman, Laura J

    2014-08-01

    Local invasion by and dissemination of cancer cells from a primary tumor are key initial steps of metastasis, the most lethal aspect of cancer. To study these processes in vitro, the invasion of cells from multicellular breast cancer aggregates embedded in three-dimensional (3D) extracellular matrix culture systems was studied. This work showed that in 3D fibrillar environments composed of collagen I, pore size--not the viscoelastic properties of the matrix--was the biophysical characteristic controlling breast cancer cell invasion efficiency. Furthermore, it was shown that fibrillar matrix architecture is a crucial factor that allows for efficient 3D invasion. In a 3D non-fibrillar environment composed of basement membrane extract (BME), invasion efficiency was greatly diminished, the mesenchymal individual mode of 3D invasion was abolished, and establishment of cell polarity and protrusions was compromised. These effects were seen even though the BME matrix has invasion permissive viscoelasticity and suitable adhesion ligands. The altered and limited invasive behavior observed in BME was rescued through introduction of fibrillar collagen into the non-fibrillar matrix. The biophysical cues of fibrillar collagen facilitated efficient invasion of sterically disadvantageous environments through assisting cell polarization and formation of stable cell protrusions. Finally, we suggest the composite matrices employed in this study consisting of fibrillar collagen I and BME in either a liquid-like or gelled state are suitable for a wide range of 3D cell studies, as these matrices combine fibrillar features that require cells to deploy integrin-dependent mechanotransduction machinery and a tunable non-fibrillar component that may require cells to adopt alternative migratory modes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Evaluation of simulated microgravity environments induced by diamagnetic levitation of plant cell suspension cultures

    NARCIS (Netherlands)

    Kamal, K.Y.; Herranz, R.; van Loon, J.J.W.A.; Christianen, P.C.M.; Medina, F.J.

    2016-01-01

    Ground-Based Facilities (GBF) are essetial tools to understand the physical and biological effects of the absence of gravity and they are necessary to prepare and complement space experiments. It has been shown previously that a real microgravity environment induces the dissociation of cell

  19. Detecting infrared luminescence and non-chemical signaling of living cells: single cell mid-IR spectroscopy in cryogenic environments

    Science.gov (United States)

    Pereverzev, Sergey

    2017-02-01

    Many life-relevant interaction energies are in IR range, and it is reasonable to believe that some biochemical reactions inside cells can results in emission of IR photons. Cells can use this emission for non-chemical and non-electrical signaling. Detecting weak infrared radiation from live cells is complicated because of strong thermal radiation background and absorption of radiation by tissues. A microfluidic device with live cells inside a vacuum cryogenic environment should suppress this background, and thereby permit observation of live cell auto-luminescence or signaling in the IR regime. One can make IR-transparent windows not emitting in this range, so only the cell and a small amount of liquid around it will emit infrared radiation. Currently mid-IR spectroscopy of single cells requires the use of a synchrotron source to measure absorption or reflection spectra. Decreasing of thermal radiation background will allow absorption and reflection spectroscopy of cells without using synchrotron light. Moreover, cell auto-luminescence can be directly measured. The complete absence of thermal background radiation for cryogenically cooled samples allows the use IR photon-sensitive detectors and obtaining single molecule sensitivity in IR photo-luminescence measurements. Due to low photon energies, photo-luminescence measurements will be non-distractive for pressures samples. The technique described here is based upon US patent 9366574.

  20. The formation of cognitive maps of adjacent environments: evidence from the head direction cell system.

    Science.gov (United States)

    Dudchenko, Paul A; Zinyuk, Larissa E

    2005-12-01

    In 2 experiments the authors tested whether the head direction (HD) cell system underlies a sense of direction maintained across environments. In Experiment 1, HD neurons failed to maintain their firing directions across T mazes in adjacent environments but rather reoriented to the T maze within each environment. Such reorientation suggests that familiar landmarks override an internal directional sense, so in Experiment 2 the authors recorded HD neurons as rats walked between novel and familiar "rooms" of a 4-chamber apparatus. In novel rooms, HD neurons maintained the firing direction of the preceding environment. However, in familiar rooms, HD neuron firing directions shifted to agree with the landmarks therein. With repeated experience, a homogeneous representation of all rooms developed in a subset of the rats. Copyright (c) 2006 APA, all rights reserved.

  1. Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

    Directory of Open Access Journals (Sweden)

    Costa Ricardo JS

    2013-01-01

    Full Text Available Abstract Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C; simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74 and control (CON, n = 12 through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM, hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD: total daily 7.7 (1.5 L/day, during running 732 (183 ml/h and sodium (total daily 3.9 (1.3 g/day, during running 270 (151 mg/L ingestion did not differ between stages in UER (p vs. CON. Exercise-induced BM loss was 2.4 (1.2% (p p > 0.05 vs. CON pre-stage. Asymptomatic hyponatraemia (n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p p  Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.

  2. Probing cell structure by controlling the mechanical environment with cell-substrate interactions.

    Science.gov (United States)

    Cheng, Chao-Min; Steward, Robert L; LeDuc, Philip R

    2009-01-19

    Recent results demonstrate the exquisite sensitivity of cell morphology and structure to mechanical stimulation. Mechanical stimulation is often coupled with cell-substrate interactions that can, in turn, influence molecular response and determine cellular fates including apoptosis, proliferation, and differentiation. To understand these effects as they specifically relate to compressive mechanical stimulation and topographic control, we developed a microfabricated system to grow cells on polydimethylsiloxane (PDMS) microchannel surfaces where we maintained compression stimulation. We also probed cellular response following compressive mechanical stimulation to PDMS substrates of varying stiffness. In these instances, we examined cytoskeletal and morphologic changes in living cells attached to our substrate following the application of localized compressive stimulation. We found that the overall morphology and cell structure, including the actin cytoskeleton, oriented in the direction of the compressive strain applied and along the topographic microchannels. Furthermore by comparing topographic response to material stiffness, we found a 40% increase in cell area for cells cultured on the microchannels versus softer PDMS as well as a decreased cell area of 30% when using softer PDMS over unmodified PDMS. These findings have implications for research in a diversity of fields including cell-material interactions, mechanotransduction, and tissue engineering.

  3. Cell-derived micro-environment helps dental pulp stem cells promote dental pulp regeneration.

    Science.gov (United States)

    Zhang, Xuexin; Li, Hui; Sun, Jingjing; Luo, Xiangyou; Yang, Hefeng; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

    2017-10-01

    The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture. DPM promoted the replication of DPSCs and exhibited retention of their mineralization. Then, the DPM-based culture strategy under odontogenic culture medium was further investigated, and the mineralization-related markers showed that DPSCs were regulated towards odontogenic differentiation. Dental pulp-like tissue with well-arranged ECM was harvested after a 2-month subcutaneous implantation in nude mice with DPM application. Additionally, DPSCs cultured on the plastic culture surface showed the up-regulation of mineralization makers in vitro, but there was a disorder in matrix formation and mineralization when the cells were cultured in vivo. DPM-based cultivation could serve as a cell niche and modulate DPSC behaviour, and this method also provided an alternative to harvest tissue-specific ECM and provided a strategy for ECM-cell interaction. © 2017 John Wiley & Sons Ltd.

  4. Automated analysis of cell-matrix adhesions in 2D and 3D environments.

    Science.gov (United States)

    Broussard, Joshua A; Diggins, Nicole L; Hummel, Stephen; Georgescu, Walter; Quaranta, Vito; Webb, Donna J

    2015-01-29

    Cell-matrix adhesions are of great interest because of their contribution to numerous biological processes, including cell migration, differentiation, proliferation, survival, tissue morphogenesis, wound healing, and tumorigenesis. Adhesions are dynamic structures that are classically defined on two-dimensional (2D) substrates, though the need to analyze adhesions in more physiologic three-dimensional (3D) environments is being increasingly recognized. However, progress has been greatly hampered by the lack of available tools to analyze adhesions in 3D environments. To address this need, we have developed a platform for the automated analysis, segmentation, and tracking of adhesions (PAASTA) based on an open source MATLAB framework, CellAnimation. PAASTA enables the rapid analysis of adhesion dynamics and many other adhesion characteristics, such as lifetime, size, and location, in 3D environments and on traditional 2D substrates. We manually validate PAASTA and utilize it to quantify rate constants for adhesion assembly and disassembly as well as adhesion lifetime and size in 3D matrices. PAASTA will be a valuable tool for characterizing adhesions and for deciphering the molecular mechanisms that regulate adhesion dynamics in 3D environments.

  5. TWRS tank waste pretreatment process development hot test siting report

    Energy Technology Data Exchange (ETDEWEB)

    Howden, G.F.; Banning, D.L.; Dodd, D.A.; Smith, D.A.; Stevens, P.F. [Westinghouse Hanford Co., Richland, WA (United States); Hansen, R.I.; Reynolds, B.A. [Pacific Northwest Lab., Richland, WA (United States)

    1995-02-01

    This report is the sixth in a series that have assessed the hot testing requirements for TWRS pretreatment process development and identified the hot testing support requirements. This report, based on the previous work, identifies specific hot test work packages, matches those packages to specific hot cell facilities, and provides recommendations of specific facilities to be employed for the pretreatment hot test work. Also identified are serious limitations in the tank waste sample retrieval and handling infrastructure. Recommendations are provided for staged development of 500 mL, 3 L, 25 L and 4000 L sample recovery systems and specific actions to provide those capabilities.

  6. Attenuated AMPA receptor expression allows glioblastoma cell survival in glutamate-rich environment.

    Directory of Open Access Journals (Sweden)

    Dannis G van Vuurden

    Full Text Available BACKGROUND: Glioblastoma multiforme (GBM cells secrete large amounts of glutamate that can trigger AMPA-type glutamate receptors (AMPARs. This commonly results in Na(+ and Ca(2+-permeability and thereby in excitotoxic cell death of the surrounding neurons. Here we investigated how the GBM cells themselves survive in a glutamate-rich environment. METHODS AND FINDINGS: In silico analysis of published reports shows down-regulation of all ionotropic glutamate receptors in GBM as compared to normal brain. In vitro, in all GBM samples tested, mRNA expression of AMPAR subunit GluR1, 2 and 4 was relatively low compared to adult and fetal total brain mRNA and adult cerebellum mRNA. These findings were in line with primary GBM samples, in which protein expression patterns were down-regulated as compared to the normal tissue. Furthermore, mislocalized expression of these receptors was found. Sequence analysis of GluR2 RNA in primary and established GBM cell lines showed that the GluR2 subunit was found to be partly unedited. CONCLUSIONS: Together with the lack of functional effect of AMPAR inhibition by NBQX our results suggest that down-regulation and afunctionality of AMPARs, enable GBM cells to survive in a high glutamate environment without going into excitotoxic cell death themselves. It can be speculated that specific AMPA receptor inhibitors may protect normal neurons against the high glutamate microenvironment of GBM tumors.

  7. Thermoregulatory responses of goats in hot environments

    Science.gov (United States)

    Maia, Alex Sandro Campos; da Silva, Roberto Gomes; Nascimento, Sheila Tavares; Nascimento, Carolina Cardoso Nagib; Pedroza, Heloisa Paula; Domingos, Herica Girlane Tertulino

    2015-08-01

    Notwithstanding the solar radiation is recognized as a detrimental factor to the thermal balance and responses of animals on the range in tropical conditions, studies on the amount of thermal radiation absorbed by goats therein associated with data on their production and heat exchange are still lacking. Metabolic heat production and the heat exchange of goats in the sun and in the shade were measured simultaneously, aiming to observe its thermal equilibrium. The results showed that black goats absorb twice as much as the white goats under intense solar radiation (higher than 800 W m-2). This observation leads to a higher surface temperature of black goats, but it must not be seen as a disadvantage, because they increase their sensible heat flow in the coat-air interface, especially the convection heat flow at high wind speeds. In the shade, no difference between the coat colours was observed and both presented a lower absorption of heat and a lower sensible heat flow gain. When solar radiation levels increases from 300 to 1000 W m-2, we observed an increase of the heat losses through latent flow in both respiratory and cutaneous surface. Cutaneous evaporation was responsible for almost 90 % of the latent heat losses, independently of the coat colour. Goats decrease the metabolic heat production under solar radiation levels up to 800 W m-2, and increase in levels higher than this, because there is an increase of the respiratory rate and of the respiratory flow, but the fractions of consumed oxygen and produced carbon dioxide are maintained stable. The respiratory rate of black goats was higher than the white ones, under 300 W m-2 (55 and 45 resp min-1) and 1000 W m-2 (120 and 95 resp min-1, respectively). It was concluded that shade or any protection against solar radiation levels above 800 Wm-2 is critical to guarantee goat's thermal equilibrium. Strategies concerning the grazing period in accordance with the time of the day alone are not appropriate, because the levels of radiation depend on the latitude of the location.

  8. Heat stress protection in abnormally hot environments.

    CSIR Research Space (South Africa)

    Schutte, PC

    1994-11-01

    Full Text Available operational protocol for emergency work where environmental heat loads exceed the upper limits for routine work. In this respect ‘routine work’ includes all practices and procedures specifically covered by COMRO User Guide no 22 of 1991....

  9. Robustness of Visual Place Cells in Dynamic Indoor and Outdoor Environment

    Directory of Open Access Journals (Sweden)

    C. Giovannangeli

    2006-06-01

    Full Text Available In this paper, a model of visual place cells (PCs based on precise neurobiological data is presented. The robustness of the model in real indoor and outdoor environments is tested. Results show that the interplay between neurobiological modelling and robotic experiments can promote the understanding of the neural structures and the achievement of robust robot navigation algorithms. Short Term Memory (STM, soft competition and sparse coding are important for both landmark identification and computation of PC activities. The extension of the paradigm to outdoor environments has confirmed the robustness of the vision-based model and pointed to improvements in order to further foster its performance.

  10. Interaction of dental pulp stem cells with Biodentine and MTA after exposure to different environments.

    Science.gov (United States)

    Agrafioti, Anastasia; Taraslia, Vasiliki; Chrepa, Vanessa; Lymperi, Stefania; Panopoulos, Panos; Anastasiadou, Ema; Kontakiotis, Evangelos G

    2016-01-01

    The aim of the present study was to evaluate and compare the cytotoxic effects of Biodentine and MTA on dental pulp stem cells (DPSCs) and to assess cell viability and adherence after material exposure to an acidic environment. DPSCs were cultured either alone or in contact with either: Biodentine; MTA set for 1 hour; or MTA set for 24 hours. After 4 and 7 days, cell viability was measured using the MTT assay. Biodentine and MTA were also prepared and packed into standardized bovine dentin disks and divided into three groups according to the storage media (n=6/group): freshly mixed materials without storage medium (Group A); materials stored in saline (Group B); materials stored in citric acid buffered at pH 5.4 (Group C). After 24 hours, DPSCs were introduced in the wells and cell adherence, viability, and cellular morphology were observed via confocal microscopy after three days of culture. Cell viability was analyzed using repeated-measures analysis of variance test with Tukey's post hoc tests (α=0.05). Biodentine expressed significantly higher cell viability compared with all other groups after 4 days, with no differences after 7 days. Notably, cell viability was significantly greater in 24-hour set MTA compared with 1-hour set MTA and control groups after 7 days. Material exposure to an acidic environment showed an increase in cell adherence and viability in both groups. Biodentine induced a significantly accelerated cell proliferation compared with MTA. Setting of these materials in the presence of citric acid enhanced DPSC viability and adherence.

  11. Interaction of dental pulp stem cells with Biodentine and MTA after exposure to different environments

    Directory of Open Access Journals (Sweden)

    Anastasia Agrafioti

    Full Text Available ABSTRACT Objective: The aim of the present study was to evaluate and compare the cytotoxic effects of Biodentine and MTA on dental pulp stem cells (DPSCs and to assess cell viability and adherence after material exposure to an acidic environment. Material and Methods: DPSCs were cultured either alone or in contact with either: Biodentine; MTA set for 1 hour; or MTA set for 24 hours. After 4 and 7 days, cell viability was measured using the MTT assay. Biodentine and MTA were also prepared and packed into standardized bovine dentin disks and divided into three groups according to the storage media (n=6/group: freshly mixed materials without storage medium (Group A; materials stored in saline (Group B; materials stored in citric acid buffered at pH 5.4 (Group C. After 24 hours, DPSCs were introduced in the wells and cell adherence, viability, and cellular morphology were observed via confocal microscopy after three days of culture. Cell viability was analyzed using repeated-measures analysis of variance test with Tukey's post hoc tests (α=0.05. Results: Biodentine expressed significantly higher cell viability compared with all other groups after 4 days, with no differences after 7 days. Notably, cell viability was significantly greater in 24-hour set MTA compared with 1-hour set MTA and control groups after 7 days. Material exposure to an acidic environment showed an increase in cell adherence and viability in both groups. Conclusions: Biodentine induced a significantly accelerated cell proliferation compared with MTA. Setting of these materials in the presence of citric acid enhanced DPSC viability and adherence.

  12. Glioblastoma-Initiating Cells: Relationship with Neural Stem Cells and the Micro-Environment

    OpenAIRE

    Goffart, Nicolas; KROONEN, Jérôme

    2013-01-01

    Glioblastoma multiforme (GBM, WHO grade IV) is the most common and lethal subtype of primary brain tumor with a median overall survival of 15 months from the time of diagnosis. The presence in GBM of a cancer population displaying neural stem cell (NSC) properties as well as tumor-initiating abilities and resistance to current therapies suggests that these glioblastoma-initiating cells (GICs) play a central role in tumor development and are closely related to NSCs. However, it is nowadays sti...

  13. The aged lymphoid tissue environment fails to support naïve T cell homeostasis

    Science.gov (United States)

    Becklund, Bryan R.; Purton, Jared F.; Ramsey, Chris; Favre, Stéphanie; Vogt, Tobias K.; Martin, Christopher E.; Spasova, Darina S.; Sarkisyan, Gor; LeRoy, Eric; Tan, Joyce T.; Wahlus, Heidi; Bondi-Boyd, Brea; Luther, Sanjiv A.; Surh, Charles D.

    2016-01-01

    Aging is associated with a gradual loss of naïve T cells and a reciprocal increase in the proportion of memory T cells. While reduced thymic output is important, age-dependent changes in factors supporting naïve T cells homeostasis may also be involved. Indeed, we noted a dramatic decrease in the ability of aged mice to support survival and homeostatic proliferation of naïve T cells. The defect was not due to a reduction in IL-7 expression, but from a combination of changes in the secondary lymphoid environment that impaired naïve T cell entry and access to key survival factors. We observed an age-related shift in the expression of homing chemokines and structural deterioration of the stromal network in T cell zones. Treatment with IL-7/mAb complexes can restore naïve T cell homeostatic proliferation in aged mice. Our data suggests that homeostatic mechanisms that support the naïve T cell pool deteriorate with age. PMID:27480406

  14. Influence of the environment and phototoxicity of the live cell imaging system at IMP microbeam facility

    Science.gov (United States)

    Liu, Wenjing; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Wei, Junzhe; Chen, Hao; Li, Yaning; Zhao, Jing; Li, Xiaoyue

    2017-08-01

    To investigate the spatiotemporal dynamics of DNA damage and repair after the ion irradiation, an online live cell imaging system has been established based on the microbeam facility at Institute of Modern Physics (IMP). The system could provide a sterile and physiological environment by making use of heating plate and live cell imaging solution. The phototoxicity was investigated through the evaluation of DNA repair protein XRCC1 foci formed in HT1080-RFP cells during the imaging exposure. The intensity of the foci induced by phototoxicity was much lower compared with that of the foci induced by heavy ion hits. The results showed that although spontaneous foci were formed due to RFP exposure during live cell imaging, they had little impact on the analysis of the recruitment kinetics of XRCC1 in the foci induced by the ion irradiation.

  15. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Matthew R. June; John L. Hurley; Mark W. Johnson

    1999-04-01

    Iron aluminide hot gas filters have been developed using powder metallurgy techniques to form seamless cylinders. Three alloys were short-term corrosion tested in simulated IGCC atmospheres with temperatures between 925 F and 1200 F with hydrogen sulfide concentrations ranging from 783 ppm{sub v} to 78,300 ppm{sub v}. Long-term testing was conducted for 1500 hours at 925 F with 78,300 ppm{sub v}. The FAS and FAL alloys were found to be corrosion resistant in the simulated environments. The FAS alloy has been commercialized.

  16. Enhancement of hybridoma formation, clonability and cell proliferation in a nanoparticle-doped aqueous environment

    Directory of Open Access Journals (Sweden)

    Karnieli Ohad

    2008-01-01

    Full Text Available Abstract Background The isolation and production of human monoclonal antibodies is becoming an increasingly important pursuit as biopharmaceutical companies migrate their drug pipelines away from small organic molecules. As such, optimization of monoclonal antibody technologies is important, as this is becoming the new rate-limiting step for discovery and development of new pharmaceuticals. The major limitations of this system are the efficiency of isolating hybridoma clones, the process of stabilizing these clones and optimization of hybridoma cell secretion, especially for large-scale production. Many previous studies have demonstrated how perturbations in the aqueous environment can impact upon cell biology. In particular, radio frequency (RF irradiation of solutions can have dramatic effects on behavior of solutions, cells and in particular membrane proteins, although this effect decays following removal of the RF. Recently, it was shown that nanoparticle doping of RF irradiated water (NPD water produced a stabilized aqueous medium that maintained the characteristic properties of RF irradiated water for extended periods of time. Therefore, the ordering effect in water of the RF irradiation can now be studied in systems that required prolonged periods for analysis, such as eukaryotic cell culture. Since the formation of hybridoma cells involves the formation of a new membrane, a process that is affected by the surrounding aqueous environment, we tested these nanoparticle doped aqueous media formulations on hybridoma cell production. Results In this study, we tested the entire process of isolation and production of human monoclonal antibodies in NPD water as a means for further enhancing human monoclonal antibody isolation and production. Our results indicate an overall enhancement of hybridoma yield, viability, clonability and secretion. Furthermore, we have demonstrated that immortal cells proliferate faster whereas primary human fibroblasts

  17. Evaporação cutânea e respiratória em ovinos sob altas temperaturas ambientes Cutaneous and respiratory evaporation rates of sheep in hot environments

    Directory of Open Access Journals (Sweden)

    Roberto Gomes da Silva

    2003-12-01

    Full Text Available Dez ovinos da raça Corriedale foram avaliados para as taxas de evaporação respiratória (E R e cutânea (E C. Cada animal foi observado até 10 vezes, sob diferentes condições de temperatura (21,1 a 41,9ºC e pressão parcial de vapor do ar (1,53 a 3,01 kPa, usando um método gravimétrico para determinar a perda de água. As médias totais foram 0,7599±0,0094 g.h-1.kg-1 para E R e 1,3029±0,0591 g.h-1.kg-1 para E C. A evaporação cutânea foi considerada como um fator importante de termólise para ovinos em ambientes quentes. São discutidos os efeitos do sexo, da espessura do velo e da temperatura e umidade do ar.Ten adult Corriedale sheep were evaluated for respiratory (E R and cutaneous (E C evaporation rates. The animals were observed about 10 times each by recording changes in their live weigth with high-sensitiviy strain gauges, under different conditions of air temperature (21.1 to 41.9ºC and partial vapour pressure (1.53 to 3.01 kPa. Average evaporation rates were 0.7599±0.0094 g.h-1.kg-1 for E R and 1.3029±0.0591 g.h-1.kg-1 for E C. Cutaneous evaporation was considered as an important heat loss mechanism for sheep in hot environments. There were discussed the effects of sex, fleece thickness, air temperature, and air humidity.

  18. Response of Human Prostate Cancer Cells to Mitoxantrone Treatment in Simulated Microgravity Environment

    Science.gov (United States)

    Zhang, Ye; Edwards, Christopher; Wu, Honglu

    2011-01-01

    This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulation of cells in response to antineoplastic agents, we cultured LNCaP cells for 96 hr either in a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as a control. 24 hr after the culture started, mitoxantrone was introduced to the cells at a final concentration of 1 M. The mitoxantrone treatment lasted 72 hr and then the cells were collected for various measurements. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not show significant differences in cell viability, growth rate, or cell cycle distribution. However, in response to mitoxantrone (1uM), a significant proportion of bioreactor cultured cells (30%) was arrested at G2 phase and a significant number of these cells were apoptotic in comparison to their static controls. The expressions of 84 oxidative stress related genes were analyzed using Qiagen PCR array to identify the possible mechanism underlying the altered responses of bioreactor culture cells to mitoxantrone. Nine out of 84 genes showed higher expression at four hour post mitoxantrone treatment in cells cultured at rotating condition compared to those at static. Taken together, the results reported here indicate that simulated microgravity may alter the responses of LNCaP cells to mitoxantrone treatment. The alteration of oxidative stress pathways

  19. Hot-pressed geopolymer

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mohammad; Maheri, Mahmoud R.

    2017-01-01

    /FA, duration of hot-pressing and sodium concentration are studied. Together with detailed experimental studies, our results reveal that the most dominant factor is the induced pressure. The main results indicated that the highest compressive strength of the geopolymer (134 MPa) could be obtained by employing...... the hot pressing, temperature and duration of 41.4 MPa, 350 °C and 20 min, respectively. The microstructure of the hot-pressed specimens showed more developed geopolymer matrix compared with conventional ones leading to higher compressive strength in much shortest time. The improved mechanical properties...

  20. KFC Server: interactive forecasting of protein interaction hot spots.

    Science.gov (United States)

    Darnell, Steven J; LeGault, Laura; Mitchell, Julie C

    2008-07-01

    The KFC Server is a web-based implementation of the KFC (Knowledge-based FADE and Contacts) model-a machine learning approach for the prediction of binding hot spots, or the subset of residues that account for most of a protein interface's; binding free energy. The server facilitates the automated analysis of a user submitted protein-protein or protein-DNA interface and the visualization of its hot spot predictions. For each residue in the interface, the KFC Server characterizes its local structural environment, compares that environment to the environments of experimentally determined hot spots and predicts if the interface residue is a hot spot. After the computational analysis, the user can visualize the results using an interactive job viewer able to quickly highlight predicted hot spots and surrounding structural features within the protein structure. The KFC Server is accessible at http://kfc.mitchell-lab.org.

  1. China's 'Hot Money' Problems

    National Research Council Canada - National Science Library

    Martin, Michael F; Morrison, Wayne M

    2008-01-01

    .... The recent large inflow of financial capital into China, commonly referred to as "hot money," has led some economists to warn that such flows may have a destabilizing effect on China's economy...

  2. Hot Weather Tips

    Science.gov (United States)

    ... hot, heavy meals and don’t use the oven. Monitor medications: Find out if the person’s medications ... nia.nih.gov Photo: By High Contrast (Own work) [CC BY 3.0 de ( http://creativecommons.org/ ...

  3. Effects of internal and external environment on health and well-being: from cell to society.

    Science.gov (United States)

    Tomljenović, Andrea

    2014-03-01

    Stem cell fate in cell culture depends on the composition of the culturing media. Every single cell in an organism is influenced by its microenvironment and surrounding cells. Biology, psychology, emotions, spirit, energy, lifestyle, culture, economic and political influences, social interactions in family, work, living area and the possibilities to expresses oneself and live full life with a sense of well-being have influence on people appearances. Disease is as much social as biological. It is a reaction of an organism to unbalancing changes in the internal environment caused by the changes in the external environment and/or by the structural and functional failures or unfortunate legacies. Health gradient in the society depends on the every day circumstances in which people live and work. The health of the population is an insight into the society. The problem facing medicine in the complex society of today cannot be resolved without the aid of social sciences, as cultural, social, ecological and mental processes affect physiological responses and health outcomes. Anthropology could be a bridge between biomedicine and social sciences and influence strategies in public health to prevent rather than cure and in education for fulfillment in life and improvement of society.

  4. Vocational options for those with sickle cell trait: questions about hypoxemia and the industrial environment

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, J.M.

    Many patients have parents and siblings who possess the sickle cell trait and who often require not only genetic counseling, but also information about their own health. Some have been informed that they cannot pursue careers in aviation. Some have been told that they are at special risk for the hypoxemic effects of heavy exertion, especially the exertion associated with sports. A few believe that certain elements of the industrial environment are unusually hazardous to them. An examination of the literature reveals little evidence in support of any of these beliefs. Most, if not all, unfavorable reports are clouded by faults of various kinds. All of them are of anecdotal type, based on small numbers of cases; the evidence offered is circumstantial. On the other hand, experiments designed to test the susceptibility of those with sickle cell trait have yielded favorable results. Studies of large populations indicate that those with the trait have normal health and normal life expectancy. There are almost as many favorable anecdotal reports as there are negative ones. We must conclude that people with sickle cell trait are just as tolerant to aviation and industrial environments as those who are homozygous for hemoglobin A. Also, there are strong indications that those with sickle cell trait are not endangered by heavy physical exertion, including the exertion of athletic competition.

  5. Early effects of altered gravity environments on plant cell growth and cell proliferation: characterization of morphofunctional nucleolar types in an Arabidopsis cell culture system

    NARCIS (Netherlands)

    Manzano, A.I.; Herranz, R.; Manzano, A.; van Loon, J.J.W.A.; Medina, F.J.

    Changes in the cell growth rate of an in vitro cellular system in Arabidopsis thaliana induced by short exposure to an altered gravity environment have been estimated by a novel approach. The method consisted of defining three structural nucleolar types which are easy and reliable indicators of the

  6. Acidic environment leads to ROS-induced MAPK signaling in cancer cells.

    Directory of Open Access Journals (Sweden)

    Anne Riemann

    Full Text Available Tumor micromilieu often shows pronounced acidosis forcing cells to adapt their phenotype towards enhanced tumorigenesis induced by altered cellular signalling and transcriptional regulation. In the presents study mechanisms and potential consequences of the crosstalk between extra- and intracellular pH (pH(e, pH(i and mitogen-activated-protein-kinases (ERK1/2, p38 was analyzed. Data were obtained mainly in AT1 R-3327 prostate carcinoma cells, but the principle importance was confirmed in 5 other cell types. Extracellular acidosis leads to a rapid and sustained decrease of pH(i in parallel to p38 phosphorylation in all cell types and to ERK1/2 phosphorylation in 3 of 6 cell types. Furthermore, p38 phosphorylation was elicited by sole intracellular lactacidosis at normal pH(e. Inhibition of ERK1/2 phosphorylation during acidosis led to necrotic cell death. No evidence for the involvement of the kinases c-SRC, PKC, PKA, PI3K or EGFR nor changes in cell volume in acidosis-induced MAPK activation was obtained. However, our data reveal that acidosis enhances the formation of reactive oxygen species (ROS, probably originating from mitochondria, which subsequently trigger MAPK phosphorylation. Scavenging of ROS prevented acidosis-induced MAPK phosphorylation whereas addition of H(2O(2 enhanced it. Finally, acidosis increased phosphorylation of the transcription factor CREB via p38, leading to increased transcriptional activity of a CRE-reporter even 24 h after switching the cells back to a normal environmental milieu. Thus, an acidic tumor microenvironment can induce a longer lasting p38-CREB-medited change in the transcriptional program, which may maintain the altered phenotype even when the cells leave the tumor environment.

  7. Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

    KAUST Repository

    Abdallah, Amir

    2017-09-22

    We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell\\'s configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.

  8. Programmatic access to logical models in the Cell Collective modeling environment via a REST API.

    Science.gov (United States)

    Kowal, Bryan M; Schreier, Travis R; Dauer, Joseph T; Helikar, Tomáš

    2016-01-01

    Cell Collective (www.cellcollective.org) is a web-based interactive environment for constructing, simulating and analyzing logical models of biological systems. Herein, we present a Web service to access models, annotations, and simulation data in the Cell Collective platform through the Representational State Transfer (REST) Application Programming Interface (API). The REST API provides a convenient method for obtaining Cell Collective data through almost any programming language. To ensure easy processing of the retrieved data, the request output from the API is available in a standard JSON format. The Cell Collective REST API is freely available at http://thecellcollective.org/tccapi. All public models in Cell Collective are available through the REST API. For users interested in creating and accessing their own models through the REST API first need to create an account in Cell Collective (http://thecellcollective.org). thelikar2@unl.edu. Technical user documentation: https://goo.gl/U52GWo. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Evaluation of materials for bipolar plates in simulated PEM fuel-cell cathodic environments

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, S.V.; Belmonte, M.R.; Moron, L.E.; Torres, J.; Orozco, G. [Centro de Investigacion y Desarrollo Technologico en Electroquimica S.C. Parcque Sanfandila, Queretaro (Mexico); Perez-Quiroz, J.T. [Mexican Transport Inst., Queretaro (Mexico); Cortes, M. A. [Mexican Petroleum Inst., Mexico City (Mexico)

    2008-04-15

    The bipolar plates in proton exchange membrane fuel cells (PEMFC) are exposed to an oxidizing environment on the cathodic side, and therefore are susceptible to corrosion. Corrosion resistant materials are needed for the bipolar plates in order to improve the lifespan of fuel cells. This article described a study in which a molybdenum (Mo) coating was deposited over austenitic stainless steel 316 and carbon steel as substrates in order to evaluate the resulting surfaces with respect to their corrosion resistance in simulated anodic and cathodic PEMFC environments. The molybdenum oxide films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. The article presented the experiment and discussed the results of the corrosion behaviour of coated stainless steel. In general, the electrochemical characterization of bare materials and coated steel consisted of slow potentiodynamic polarization curves followed by a constant potential polarization test. The test medium was 0.5M sulfuric acid with additional introduction of oxygen to simulate the cathodic environment. All tests were performed at ambient temperature and at 50 degrees Celsius. The potentiostat used was a Gamry instrument. It was concluded that it is possible to deposit Mo-oxides on steel without using another alloying metal. The preferred substrate for corrosion prevention was found to be an alloy with high chromium content. 24 refs., 4 figs.

  10. Ergonomic Optimization of a Manufacturing System Work Cell in a Virtual Environment

    Directory of Open Access Journals (Sweden)

    F. Caputo

    2006-01-01

    Full Text Available The paper deals with the development of a methodology for studying, in a virtual environment, the ergonomics of a work cell in an automotive manufacturing system. The methodology is based on the use of digital human models and virtual reality techniques in order to simulate, in a virtual environment, human performances during the execution of assembly operations. The objective is to define the optimum combination of those geometry features that influence human postures during assembly operation in a work cell. In the demanding global marketplace, ensuring that human factors are comprehensively addressed is becoming an increasingly important aspect of design. Manufacturers have to design work cells that conform to all relevant Health and Safety standards. The proposed methodology can assist the designer to evaluate the performance of workers in a workplace before it has been realized. The paper presents an analysis of a case study proposed by COMAU, a global supplier of industrial automation systems for the automotive manufacturing sector and a global provider of full maintenance services. The study and all the virtual simulations have been carried out in the Virtual Reality Laboratory of the Competence Regional Center for the qualification of transportation systems (CRdC “Trasporti” - www.centrodicompetenzatrasporti.unina. it, which was founded by the Campania region with the aim of delivering advanced services and introducing new technologies into local companies operating in the field of transport. 

  11. Systematic analysis of embryonic stem cell differentiation in hydrodynamic environments with controlled embryoid body size

    Science.gov (United States)

    Kinney, Melissa A.; Saeed, Rabbia; McDevitt, Todd C.

    2015-01-01

    The sensitivity of stem cells to environmental perturbations has prompted many studies which aim to characterize the influence of mechanical factors on stem cell morphogenesis and differentiation. Hydrodynamic cultures, often employed for large scale bioprocessing applications, impart complex fluid shear and transport profiles, and influence cell fate as a result of changes in media mixing conditions. However, previous studies of hydrodynamic cultures have been limited in their ability to distinguish confounding factors that may affect differentiation, including modulation of embryoid body size in response to changes in the hydrodynamic environment. In this study, we demonstrate the ability to control and maintain embryoid body (EB) size using a combination of forced aggregation formation and rotary orbital suspension culture, in order to assess the impact of hydrodynamic cultures on ESC differentiation, independent of EB size. Size-controlled EBs maintained at different rotary orbital speeds exhibited similar morphological features and gene expression profiles, consistent with ESC differentiation. The similar differentiation of ESCs across a range of hydrodynamic conditions suggests that controlling EB formation and resultant size may be important for scalable bioprocessing applications, in order to standardize EB morphogenesis. However, perturbations in the hydrodynamic environment also led to subtle changes in differentiation toward certain lineages, including temporal modulation of gene expression, as well changes in the relative efficiencies of differentiated phenotypes, thereby highlighting important tissue engineering principles that should be considered for implementation in bioreactor design, as well as for directed ESC differentiation. PMID:22609810

  12. Human mesenchymal stem cells creating an immunosuppressive environment and promote breast cancer in mice

    Science.gov (United States)

    Ljujic, Biljana; Milovanovic, Marija; Volarevic, Vladislav; Murray, Bridgid; Bugarski, Diana; Przyborski, Stefan; Arsenijevic, Nebojsa; Lukic, Miodrag L.; Stojkovic, Miodrag

    2013-01-01

    Human mesenchymal stem cells (hMSC) can home to tumor sites and promote tumor growth. The effects of hMSC on tumor growth are controversial and involvement of hMSC in tumor immunology has not been adequately addressed. Therefore, we investigated whether injection of hMSC affects tumor appearance, growth and metastasis, and anti-tumor immunity in an experimental animal model of metastatic breast cancer. Injection of hMSC in BALB/c mice bearing mammary carcinoma promoted tumor growth and metastasis, which was accompanied by lower cytotoxic activity of splenocytes, NK cells and CD8+ T cells in vitro. Tumor-bearing mice that received hMSC had significantly lower percentages of CD3+NKp46+ NKT-like, higher percentages of CD4+Foxp3+ T cells, increased serum levels of Th2 and decreased serum levels of Th1 cytokines, and significantly higher number of CD4+ cells expressing IL-10. These results demonstrate that immunosuppressive environment created by hMSC promoted breast tumor growth and metastasis in mice. PMID:23892388

  13. Electrochemical performance and transport properties of a Nafion membrane in a hydrogen-bromine cell environment

    Science.gov (United States)

    Baldwin, Richard S.

    1987-01-01

    The overall energy conversion efficiency of a hydrogen-bromine energy storage system is highly dependent upon the characteristics and performance of the ion-exchange membrane utilized as a half-cell separator. The electrochemical performance and transport properties of a duPont Nafion membrane in an aqueous HBr-Br2 environment were investigated. Membrane conductivity data are presented as a function of HBr concentration and temperature for the determination of ohmic voltage losses across the membrane in an operational cell. Diffusion-controlled bromine permeation rates and permeabilities are presented as functions of solution composition and temperature. Relationships between the degree of membrane hydration and the membrane transport characteristics are discussed. The solution chemistry of an operational hydrogen-bromine cell undergoing charge from 45% HBr to 5% HBr is discussed, and, based upon the experimentally observed bromine permeation behavior, predicted cell coulombic losses due to bromine diffusion through the membrane are presented as a function of the cell state-of-charge.

  14. Endolithic microbial life in hot and cold deserts

    Science.gov (United States)

    Friedmann, E. I.

    1980-01-01

    Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

  15. Multijunction Solar Cell Efficiencies: Effect of Spectral Window, Optical Environment and Radiative Coupling

    Science.gov (United States)

    2014-09-04

    the optical bandgap because nonradiative recombination has been minimized with advanced growth processes.6,9 The optical environment of a solar cell...caltech.edu bMaterials Science Division Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA cDepartment of Physics, King...c4ee01060d Received 3rd April 2014 Accepted 15th July 2014 DOI: 10.1039/c4ee01060d www.rsc.org/ees Broader context Even with the recent advances in

  16. Impact of fetal and neonatal environment on beta cell function and development of diabetes

    DEFF Research Database (Denmark)

    Nielsen, Jens H; Haase, Tobias N; Jaksch, Caroline

    2014-01-01

    The global epidemic of diabetes is a serious threat against health and healthcare expenses. Although genetics is important it does not explain the dramatic increase in incidence, which must involve environmental factors. Two decades ago the concept of the thrifty phenotype was introduced, stating...... that the intrauterine environment during pregnancy has an impact on the gene expression that may persist until adulthood and cause metabolic diseases like obesity and type 2 diabetes. As the pancreatic beta cells are crucial in the regulation of metabolism this article will describe the influence of normal pregnancy...... on the beta cells in both the mother and the fetus and how various conditions like diabetes, obesity, overnutrition and undernutrition during and after pregnancy may influence the ability of the offspring to adapt to changes in insulin demand later in life. The influence of environmental factors including...

  17. Elucidating the Beneficial Effect of Corncob Acid Hydrolysate Environment on Lipid Fermentation of Trichosporon dermatis by Method of Cell Biology.

    Science.gov (United States)

    Huang, Chao; Wang, Can; Xiong, Lian; Chen, Xue-Fang; Lin, Xiao-Qing; Qi, Gao-Xiang; Shi, Si-Lan; Wang, Bo; Chen, Xin-De

    2016-04-01

    In present study, the beneficial effect of corncob acid hydrolysate environment on lipid fermentation of Trichosporon dermatis was elucidated by method of cell biology (mainly using flow cytometry and microscope) for the first time. Propidium iodide (PI) and rhodamine 123 (Rh123) staining showed that corncob acid hydrolysate environment was favorable for the cell membrane integrity and mitochondrial membrane potential of T. dermatis and thus made its lipid fermentation more efficient. Nile red (NR) staining showed that corncob acid hydrolysate environment made the lipid accumulation of T. dermatis slower, but this influence was not serious. Moreover, the cell morphology of T. dermatis elongated in the corncob acid hydrolysate, but the cell morphology changed as elliptical-like during fermentation. Overall, this work offers one simple and effective method to evaluate the influence of lignocellulosic hydrolysates environment on lipid fermentation.

  18. IR Hot Wave

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  19. Solar-powered hot-water system

    Science.gov (United States)

    Collins, E. R.

    1979-01-01

    Hot-water system requires no external power except solar energy. System is completely self-controlling. It includes solar-powered pump, solar-thermally and hydrothermally operated valves, and storage tank filled with open-celled foam, to maintain thermal stratification in stored water.

  20. Extracting hot carriers from photoexcited semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  1. Regional Cellular Environment Shapes Phenotypic Variations of Hippocampal and Neocortical Chandelier Cells.

    Science.gov (United States)

    Ishino, Yugo; Yetman, Michael J; Sossi, Serena M; Steinecke, André; Hayano, Yasufumi; Taniguchi, Hiroki

    2017-10-11

    Different cortical regions processing distinct information, such as the hippocampus and the neocortex, share common cellular components and circuit motifs but form unique networks by modifying these cardinal units. Cortical circuits include diverse types of GABAergic interneurons (INs) that shape activity of excitatory principal neurons (PNs). Canonical IN types conserved across distinct cortical regions have been defined by their morphological, electrophysiological, and neurochemical properties. However, it remains largely unknown whether canonical IN types undergo specific modifications in distinct cortical regions and display "regional variants." It is also poorly understood whether such phenotypic variations are shaped by early specification or regional cellular environment. The chandelier cell (ChC) is a highly stereotyped IN type that innervates axon initial segments of PNs and thus serves as a good model with which to address this issue. Here, we show that Cadherin-6 (Cdh6), a homophilic cell adhesion molecule, is a reliable marker of ChCs and Cdh6-CreER mice (both sexes) provide genetic access to hippocampal ChCs (h-ChCs). We demonstrate that, compared with neocortical ChCs (nc-ChCs), h-ChCs cover twice as much area and innervate twice as many PNs. Interestingly, a subclass of h-ChCs exhibits calretinin (CR) expression, which is not found in nc-ChCs. Furthermore, we find that h-ChCs appear to be born earlier than nc-ChCs. Surprisingly, despite the difference in temporal origins, ChCs display host-region-dependent axonal/synaptic organization and CR expression when transplanted heterotopically. These results suggest that local cellular environment plays a critical role in shaping terminal phenotypes of regional IN variants in the hippocampus and the neocortex. SIGNIFICANCE STATEMENT Canonical interneuron (IN) types conserved across distinct cortical regions such as the hippocampus and the neocortex are defined by morphology, physiology, and gene expression

  2. TRUEX hot demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlain, D.B.; Leonard, R.A.; Hoh, J.C.; Gay, E.C.; Kalina, D.G.; Vandegrift, G.F.

    1990-04-01

    In FY 1987, a program was initiated to demonstrate technology for recovering transuranic (TRU) elements from defense wastes. This hot demonstration was to be carried out with solution from the dissolution of irradiated fuels. This recovery would be accomplished with both PUREX and TRUEX solvent extraction processes. Work planned for this program included preparation of a shielded-cell facility for the receipt and storage of spent fuel from commercial power reactors, dissolution of this fuel, operation of a PUREX process to produce specific feeds for the TRUEX process, operation of a TRUEX process to remove residual actinide elements from PUREX process raffinates, and processing and disposal of waste and product streams. This report documents the work completed in planning and starting up this program. It is meant to serve as a guide for anyone planning similar demonstrations of TRUEX or other solvent extraction processing in a shielded-cell facility.

  3. Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

    Science.gov (United States)

    Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

    2012-03-01

    Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion. Copyright © 2011 AlphaMed Press.

  4. Bacillus cereus cell response upon exposure to acid environment: towards the identification of potential biomarkers

    Directory of Open Access Journals (Sweden)

    Noémie eDESRIAC

    2013-10-01

    Full Text Available Microorganisms are able to adapt to different environments and evolve rapidly, allowing them to cope with their new environments. Such adaptive response and associated protections towards other lethal stresses, is a crucial survival strategy for a wide spectrum of microorganisms, including food spoilage bacteria, pathogens and organisms used in functional food applications. The growing demand for minimal processed food yields to an increasing use of combination of hurdles or mild preservation factors in the food industry. A commonly used hurdle is low pH which allows the decrease in bacterial growth rate but also the inactivation of pathogens or spoilage microorganisms. Bacillus cereus is a well-known food-borne pathogen leading to economical and safety issues in food industry. Because survival mechanisms implemented will allow bacteria to cope with environmental changes, it is important to provide understanding of B. cereus stress response. Thus this review deals with the adaptive traits of B. cereus cells facing to acid stress conditions. The acid stress response of B. cereus could be divided into four groups (i general stress response (ii pH homeostasis, (iii metabolic modifications and alkali production and (iv secondary oxidative stress response. This current knowledge may be useful to understand how B. cereus cells may cope to acid environment such as encountered in food products and thus to find some molecular biomarkers of the bacterial behaviour. These biomarkers could be furthermore used to develop new microbial behaviour prediction tools which can provide insights into underlying molecular physiological states which govern the behaviour of microorganisms and thus opening the avenue toward the detection of stress adaptive behaviour at an early stage and the control of stress-induced resistance throughout the food chain.

  5. A high parasite density environment induces transcriptional changes and cell death in Plasmodium falciparum blood stages.

    Science.gov (United States)

    Chou, Evelyn S; Abidi, Sabia Z; Teye, Marian; Leliwa-Sytek, Aleksandra; Rask, Thomas S; Cobbold, Simon A; Tonkin-Hill, Gerry Q; Subramaniam, Krishanthi S; Sexton, Anna E; Creek, Darren J; Daily, Johanna P; Duffy, Michael F; Day, Karen P

    2017-12-27

    Transient regulation of Plasmodium numbers below the density that induces fever has been observed in chronic malaria infections in humans. This species transcending control cannot be explained by immunity alone. Using an in vitro system we have observed density dependent regulation of malaria population size as a mechanism to possibly explain these in vivo observations. Specifically, Plasmodium falciparum blood stages from a high but not low-density environment exhibited unique phenotypic changes during the late trophozoite (LT) and schizont stages of the intraerythrocytic cycle. These included in order of appearance: failure of schizonts to mature and merozoites to replicate, apoptotic-like morphological changes including shrinking, loss of mitochondrial membrane potential, and blebbing with eventual release of aberrant parasites from infected erythrocytes. This unique death phenotype was triggered in a stage-specific manner by sensing of a high-density culture environment. Conditions of glucose starvation, nutrient depletion, and high lactate could not induce the phenotype. A high-density culture environment induced rapid global changes in the parasite transcriptome including differential expression of genes involved in cell remodeling, clonal antigenic variation, metabolism, and cell death pathways including an apoptosis-associated metacaspase gene. This transcriptional profile was also characterized by concomitant expression of asexual and sexual stage-specific genes. The data show strong evidence to support our hypothesis that density sensing exists in P. falciparum. They indicate that an apoptotic-like mechanism may play a role in P. falciparum density regulation, which, as in yeast, has features quite distinguishable from mammalian apoptosis. Gene expression data are available in the GEO databases under the accession number GSE91188. © 2017 Federation of European Biochemical Societies.

  6. Cost-benefit analysis of the mechanisms that enable migrating cells to sustain motility upon changes in matrix environments.

    Science.gov (United States)

    Tozluoglu, Melda; Mao, Yanlan; Bates, Paul A; Sahai, Erik

    2015-05-06

    Cells can move through extracellular environments with varying geometries and adhesive properties. Adaptation to these differences is achieved by switching between different modes of motility, including lamellipod-driven and blebbing motility. Further, cells can modulate their level of adhesion to the extracellular matrix (ECM) depending on both the level of force applied to the adhesions and cell intrinsic biochemical properties. We have constructed a computational model of cell motility to investigate how motile cells transition between extracellular environments with varying surface continuity, confinement and adhesion. Changes in migration strategy are an emergent property of cells as the ECM geometry and adhesion changes. The transition into confined environments with discontinuous ECM fibres is sufficient to induce shifts from lamellipod-based to blebbing motility, while changes in confinement alone within a continuous geometry are not. The geometry of the ECM facilitates plasticity, by inducing shifts where the cell has high marginal gain from a mode change, and conserving persistency where the cell can continue movement regardless of the motility mode. This regulation of cell motility is independent of global changes in cytoskeletal properties, but requires locally higher linkage between the actin network and the plasma membrane at the cell rear, and changes in internal cell pressure. In addition to matrix geometry, we consider how cells might transition between ECM of different adhesiveness. We find that this requires positive feedback between the forces cells apply on the adhesion points, and the strength of the cell-ECM adhesions on those sites. This positive feedback leads to the emergence of a small number of highly adhesive cores, similar to focal adhesions. While the range of ECM adhesion levels the cell can invade is expanded with this feedback mechanism; the velocities are lowered for conditions where the positive feedback is not vital. Thus

  7. Hydrogel Environment Supports Cell Culture Expansion of a Grade IV Astrocytoma.

    Science.gov (United States)

    Jogalekar, Manasi P; Cooper, Leigh G; Serrano, Elba E

    2017-09-01

    Malignant astrocytomas are aggressive cancers of glial origin that can develop into invasive brain tumors. The disease has poor prognosis and high recurrence rate. Astrocytoma cell lines of human origin are an important tool in the experimental pathway from bench to bedside because they afford a convenient intermediate system for in vitro analysis of brain cancer pathogenesis and treatment options. We undertook the current study to determine whether hydrogel culture methods could be adapted to support the growth of astrocytoma cell lines, thereby facilitating a system that may be biologically more similar to in vivo tumor tissue. Our experimental protocols enabled maintenance of Grade IV astrocytoma cell lines in conventional monolayer culture and in the extracellular matrix hydrogel, Geltrex™. Light and fluorescence microscopy showed that hydrogel environments promoted cellular reorganization from dispersed cells into multilayered aggregates. Transmission electron microscopy revealed the prevalence of autophagy and nuclear membrane distortions in both culture systems. Analysis of microarray Gene Expression Omnibus (GEO) DataSets highlighted expression of genes implicated in pathways for cancer progression and autophagy. A pilot quantitative polymerase chain reaction (qPCR) analysis of the autophagic biomarkers, Beclin 1 (BECN1) and microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B), with two reference genes (beta actin, ACTB; glyceraldehyde 3-phosphate dehydrogenase, GAPDH), uncovered a relative increase of BECN1 and LC3B in hydrogel cultures of astrocytoma as compared to the monolayer. Taken together, results establish that ultrastructural and molecular characteristics of autophagy are features of this astrocytoma cell line, and that hydrogel culture systems can afford novel opportunities for in vitro studies of glioma.

  8. Adverse early life environment increases hippocampal microglia abundance in conjunction with decreased neural stem cells in juvenile mice.

    Science.gov (United States)

    Cohen, Susan; Ke, Xingrao; Liu, Qiuli; Fu, Qi; Majnik, Amber; Lane, Robert

    2016-12-01

    Adverse maternal lifestyle resulting in adverse early life environment (AELE) increases risks for neuropsychiatric disorders in offspring. Neuropsychiatric disorders are associated with impaired neurogenesis and neuro-inflammation in the hippocampus (HP). Microglia are neuro-inflammatory cells in the brain that regulate neurogenesis via toll-like receptors (TLR). TLR-9 is implicated in neurogenesis inhibition and is responsible for stress-related inflammatory responses. We hypothesized that AELE would increase microglia cell count and increase TLR-9 expression in juvenile mouse HP. These increases in microglia cell count and TLR-9 expression would be associated with decrease neural stem cell count and neuronal cell count. We developed a mouse model of AELE combining Western diet and a stress environment. Stress environment consisted of random change from embryonic day 13 (E13) to E17 as well as static change in maternal environment from E13 to postnatal day 21(P21). At P21, we measured hippocampal cell numbers of microglia, neural stem cell and neuron, as well as hippocampal TLR-9 expression. AELE significantly increased total microglia number and TLR-9 expression in the hippocampus. Concurrently, AELE significantly decreased neural stem cell and neuronal numbers. AELE increased the neuro-inflammatory cellular response in the juvenile HP. We speculate that increased neuro-inflammatory responses may contribute to impaired neurogenesis seen in this model. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

  9. Experience with hot catchpots

    Energy Technology Data Exchange (ETDEWEB)

    1945-02-02

    The first part of this report was actually a letter regarding the question, ''could the hot circulating pump be omitted when processing pitch at 700 atm.'' It had been stated that the hot circulation pump could be omitted if the quantity of cold letdown was correspondingly increased. The latest experiences with the catchpot at Poelitz showed the following. When running pitch, tar, or petroleum in the liquid-phase stalls, frequent trouble with the hot catchpot was encountered due to the coking. This coking was caused by irregular letdown yield, which could not be avoided due to small temperature fluctuations in the stall. This caused interruption of the uniform flow in the hot catchpot and the deposition of the solids contained in the letdown, largely catalyst solids, due to the asphalt content. Coking of the product was initiated by this concentration of catalyst solids. A perforated double jacket was inserted in the conical part of the catchpot through which about 3000 m/sup 3/ per hour of cold gas was blown in continuously. By this agitation and cooling in the lowest part of the catchpot, catalyst deposits were prevented from forming and the product received a continuous added supply of hydrogen. Another letter was given discussing the same question and an alternate solution. This second letter described Welheim's design for the hot catchpot. It featured introduction of 5000 to 6000 m/sup 3//hr of cold circulating gas into the lower part of the catchpot, and withdrawal of letdown from a point above the gas inlet. The advantages were continued agitation and cooling of the sludge and constant retention of some cold sludge in the catchpot (which evened out throughput and content fluctuations)

  10. The postischemic environment differentially impacts teratoma or tumor formation after transplantation of human embryonic stem cell-derived neural progenitors

    DEFF Research Database (Denmark)

    Seminatore, Christine; Polentes, Jerome; Ellman, Ditte

    2010-01-01

    Risk of tumorigenesis is a major obstacle to human embryonic and induced pluripotent stem cell therapy. Likely linked to the stage of differentiation of the cells at the time of implantation, formation of teratoma/tumors can also be influenced by factors released by the host tissue. We have...... analyzed the relative effects of the stage of differentiation and the postischemic environment on the formation of adverse structures by transplanted human embryonic stem cell-derived neural progenitors....

  11. Metamaterial perfect absorber based hot electron photodetection.

    Science.gov (United States)

    Li, Wei; Valentine, Jason

    2014-06-11

    While the nonradiative decay of surface plasmons was once thought to be only a parasitic process that limits the performance of plasmonic devices, it has recently been shown that it can be harnessed in the form of hot electrons for use in photocatalysis, photovoltaics, and photodetectors. Unfortunately, the quantum efficiency of hot electron devices remains low due to poor electron injection and in some cases low optical absorption. Here, we demonstrate how metamaterial perfect absorbers can be used to achieve near-unity optical absorption using ultrathin plasmonic nanostructures with thicknesses of 15 nm, smaller than the hot electron diffusion length. By integrating the metamaterial with a silicon substrate, we experimentally demonstrate a broadband and omnidirectional hot electron photodetector with a photoresponsivity that is among the highest yet reported. We also show how the spectral bandwidth and polarization-sensitivity can be manipulated through engineering the geometry of the metamaterial unit cell. These perfect absorber photodetectors could open a pathway for enhancing hot electron based photovoltaic, sensing, and photocatalysis systems.

  12. The hot chocolate effect

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Frank S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)

    1982-05-01

    The "hot chocolate effect" was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the ten percent accuracy of the experiments.

  13. Diversity of Crenarchaeota in terrestrial hot springs in Tengchong, China.

    Science.gov (United States)

    Song, Zhao-Qi; Chen, Jing-Quan; Jiang, Hong-Chen; Zhou, En-Min; Tang, Shu-Kun; Zhi, Xiao-Yang; Zhang, Li-Xin; Zhang, Chuan-Lun L; Li, Wen-Jun

    2010-05-01

    Diversity of Crenarchaeota was investigated in eight terrestrial hot springs (pH 2.8-7.7; temperature 44-96 degrees C) located in Tengchong, China, using 16S rRNA gene phylogenetic analysis. A total of 826 crenarchaeotal clones were sequenced and a total of 47 operational taxonomic units (OTUs) were identified. Most (93%) of the identified OTUs were closely related (89-99%) to those retrieved from hot springs and other thermal environments. Our data showed that temperature may predominate over pH in affecting crenarchaeotal diversity in Tengchong hot springs. Crenarchaeotal diversity in moderate-temperature (59-77 degrees C) hot springs was the highest, indicating that the moderately hot-temperature springs may provide optimal conditions for speciation of Crenarchaeota.

  14. Slow hot carrier cooling in cesium lead iodide perovskites

    Science.gov (United States)

    Shen, Qing; Ripolles, Teresa S.; Even, Jacky; Ogomi, Yuhei; Nishinaka, Koji; Izuishi, Takuya; Nakazawa, Naoki; Zhang, Yaohong; Ding, Chao; Liu, Feng; Toyoda, Taro; Yoshino, Kenji; Minemoto, Takashi; Katayama, Kenji; Hayase, Shuzi

    2017-10-01

    Lead halide perovskites are attracting a great deal of interest for optoelectronic applications such as solar cells, LEDs, and lasers because of their unique properties. In solar cells, heat dissipation by hot carriers results in a major energy loss channel responsible for the Shockley-Queisser efficiency limit. Hot carrier solar cells offer the possibility to overcome this limit and achieve energy conversion efficiency as high as 66% by extracting hot carriers. Therefore, fundamental studies on hot carrier relaxation dynamics in lead halide perovskites are important. Here, we elucidated the hot carrier cooling dynamics in all-inorganic cesium lead iodide (CsPbI3) perovskite using transient absorption spectroscopy. We observe that the hot carrier cooling rate in CsPbI3 decreases as the fluence of the pump light increases and the cooling is as slow as a few 10 ps when the photoexcited carrier density is 7 × 1018 cm-3, which is attributed to phonon bottleneck for high photoexcited carrier densities. Our findings suggest that CsPbI3 has a potential for hot carrier solar cell applications.

  15. Investigating the Influence of Extracellular Matrix and Glycolytic Metabolism on Muscle Stem Cell Migration on Their Native Fiber Environment

    Directory of Open Access Journals (Sweden)

    Gaia Butera

    2015-07-01

    Full Text Available The composition of the extracellular matrix (ECM of skeletal muscle fibers is a unique environment that supports the regenerative capacity of satellite cells; the resident stem cell population. The impact of environment has great bearing on key properties permitting satellite cells to carry out tissue repair. In this study, we have investigated the influence of the ECM and glycolytic metabolism on satellite cell emergence and migration—two early processes required for muscle repair. Our results show that both influence the rate at which satellite cells emerge from the sub-basal lamina position and their rate of migration. These studies highlight the necessity of performing analysis of satellite behavior on their native substrate and will inform on the production of artificial scaffolds intended for medical uses.

  16. Steering acoustically propelled nanowire motors toward cells in a biologically compatible environment using magnetic fields.

    Science.gov (United States)

    Ahmed, Suzanne; Wang, Wei; Mair, Lamar O; Fraleigh, Robert D; Li, Sixing; Castro, Luz Angelica; Hoyos, Mauricio; Huang, Tony Jun; Mallouk, Thomas E

    2013-12-31

    The recent discovery of fuel-free propulsion of nanomotors using acoustic energy has provided a new avenue for using nanomotors in biocompatible media. Crucial to the application of nanomotors in biosensing and biomedical applications is the ability to remotely control and steer them toward targets of interest, such as specific cells and tissues. We demonstrate in vitro magnetic steering of acoustically powered nanorod motors in a biologically compatible environment. Steering was accomplished by incorporating (40 ± 5) nm thick nickel stripes into the electrochemically grown nanowires. An external magnetic field of 40-45 mT was used to orient the motors, which were acoustically propelled along their long axes. In the absence of a magnetic field, (300 ± 30) nm diameter, (4.3 ± 0.2) μm long nanowires with (40 ± 5) nm thick magnetic stripes exhibit the same self-acoustophoretic behavior, including pattern formation into concentric nanowire circles, aligned spinning chains, and autonomous axial motion, as their non-magnetic counterparts. In a magnetic field, these wires and their paths are oriented as evidenced by their relatively linear trajectories. Coordinated motion of multiple motors and targeting of individual motors toward HeLa cells with micrometer-level precision was demonstrated.

  17. Blood vessel tortuosity selects against evolution of aggressive tumor cells in confined tissue environments: A modeling approach.

    Directory of Open Access Journals (Sweden)

    András Szabó

    2017-07-01

    Full Text Available Cancer is a disease of cellular regulation, often initiated by genetic mutation within cells, and leading to a heterogeneous cell population within tissues. In the competition for nutrients and growth space within the tumors the phenotype of each cell determines its success. Selection in this process is imposed by both the microenvironment (neighboring cells, extracellular matrix, and diffusing substances, and the whole of the organism through for example the blood supply. In this view, the development of tumor cells is in close interaction with their increasingly changing environment: the more cells can change, the more their environment will change. Furthermore, instabilities are also introduced on the organism level: blood supply can be blocked by increased tissue pressure or the tortuosity of the tumor-neovascular vessels. This coupling between cell, microenvironment, and organism results in behavior that is hard to predict. Here we introduce a cell-based computational model to study the effect of blood flow obstruction on the micro-evolution of cells within a cancerous tissue. We demonstrate that stages of tumor development emerge naturally, without the need for sequential mutation of specific genes. Secondly, we show that instabilities in blood supply can impact the overall development of tumors and lead to the extinction of the dominant aggressive phenotype, showing a clear distinction between the fitness at the cell level and survival of the population. This provides new insights into potential side effects of recent tumor vasculature normalization approaches.

  18. Analysis and validation center for ITER RH maintenance scenarios in a virtual environment

    Energy Technology Data Exchange (ETDEWEB)

    Elzendoorn, B.S.Q., E-mail: B.S.Q.Elzendoorn@rijnhuizen.nl [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster and ITER-NL, PO Box 1207, 3430 BE, Nieuwegein (Netherlands); Baar, M. de [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster and ITER-NL, PO Box 1207, 3430 BE, Nieuwegein (Netherlands); Hamilton, D. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance Cedex (France); Heemskerk, C.J.M. [Heemskerk Innovative Technology, Sassenheim (Netherlands); Koning, J.F.; Ronden, D.M.S. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster and ITER-NL, PO Box 1207, 3430 BE, Nieuwegein (Netherlands)

    2012-03-15

    A facility for detailed simulation of maintenance processes in the ITER Hot Cell Facility (HCF) has been taken into operation. The facility mimics the Remote Handling (RH) work-cells as are presently foreseen. Novel virtual reality (VR) technology, extended with a physics engine is used to create a realistic setting in which a team of Remote Handling (RH) operators can interact with a virtual Hot Cell environment. The physics engine is used to emulate the Hot Cell behavior and to provide tactile feed-back of the (virtual) slave. Multi-operator maintenance scenarios can be developed and tested in virtual reality. Complex interactions between the RH operators and the HCF control system software will be tested. Task performance will be quantified and operational resource consumption will be estimated.

  19. Analysis of space environment damage to solar cell assemblies from LDEF experiment A0171-GSFC test plate

    Science.gov (United States)

    Hill, David C.; Rose, M. Frank

    1994-09-01

    The results of the postflight analysis of the solar cell assemblies from the LDEF (Long Duration Exposure facility) experiment A0171 is provided in this NASA sponsored research project. The following data on this research are provided as follows: (1) solar cell description, including, substrate composition and thickness, crystal orientation, anti-reflective coating composition and thickness; (2) preflight characteristics of the solar cell assemblies with respect to current and voltage; and (3) post-flight characteristics of the solar cell assemblies with respect to voltage and current. These solar cell assemblies are part of the Goddard Space Flight Center test plate which was designed to test the space environment effects (radiation, atomic oxygen, thermal cycling, meteoroid and debris) on conductively coated solar cell coversheets, various electrical bond materials, solar cell performance, and other material properties where feasible.

  20. Mining Hot Springs for Biodiversity and Novel Enzymes

    DEFF Research Database (Denmark)

    Islin, Sóley Ruth

    The existence of microbial life at extreme environments, such as hot springs, has been known for a few decades. The remarkable ability of microorganisms to withstand the extreme conditions of their habitats, has astounded scientist and pushed the limits of what was considered possible. Thermophilic...... the biodiversity within the environment. By comparing several metagenomic data sets from hot spring from around the world, we could analyze community structures of cellular microorganisms as well as the biodiversity of viral sequences. We found that crenarchaeal viruses are dominant in these environments...

  1. Advances in hot gas filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.

    The past decade has seen the introduction of new filter media specifically designed for 'hot-gas' filtration. These media are available as woven or knitted fabrics and as non-wovens, i.e. needled felts. Needlefelted fabrics have proven so highly successful in the dedusting of hot gases that they are widely used nowadays in this new and necessary technology. Hot-gas filtration offers advantages in, for example, the saving or recycling of energy, the elimination of the cooling process, and the short-circuiting of process steps. This paper gives a survey of the types of textile fibres available for hot-gas filtration from the more recently developed organic fibres to refractory fibres. It describes, compares and contrasts their salient properties and lists the uses to which they may be put. It concentrates on such fibres which are generally referred to as 'high performance materials', since they are expected to provide satisfactory performance under extreme conditions of temperature, chemical environment and mechanical stress. It touches on filtration theory governing the collection mechanism. 9 refs., 7 figs., 3 tabs.

  2. Computerized morphometric analysis of human leukemic and lymphomatous cells in various histological environments of central nervous system.

    Science.gov (United States)

    Nowacki, P; Zdziarska, B; Grzelec, H

    1999-01-01

    The leukemic and lymphomatous cells appear within the central nervous system (CNS) in 5 different environments: in CNS vessels, perivascular spaces, meninges, nervous tissue and in CNS hemorrhages. A computerized analysis of geometric and densitometric parameters of neoplastic cells in these compartments were done for better recognition of penetration and spreading of leukemia and lymphoma within the CNS. A post-mortem neuropathological investigations were carried out on 16 patients deceased due to acute myeloblastic leukemias (M1, M2), blastic phase of chronic myelogenous leukemia, lymphoblastic lymphoma and acute lymphoblastic leukemia. Following nuclear parameters of neoplastic cells were analyzed: area, "form factor", mean, minimal and maximal density. An evident differentiation of nuclear parameters within the CNS environments was found. The nuclei within the perivascular spaces and especially in CNS hemorrhages were significantly shrunken and dense (p < 0.01), but not evidently deformed. The intracerebral infiltrates appeared to be most differentiated group (p < 0.01). Morphometric values of leukemic and lymphomatous cells show regressive changes of neoplastic cells within the CNS perivascular spaces, nervous tissue and in CNS hemorrhages. These changes depend on unfavorable factors in the mentioned CNS environments, and also on time of cell persistence in these regions. Meninges were found to be the only CNS structure facilitating the survival and proliferation of leukemic and lymphomatous cells.

  3. Aerial ULV application of permethrin against adult mosquitoes in an extreme hot-arid zone

    Science.gov (United States)

    Aerial ULV insecticide application is an established strategy for adult mosquito control in tropical, hot-humid, or temperate environments. However, not enough is known regarding the efficacy of aerial applications in hot-arid environments similar to those encountered by US military personnel, where...

  4. Low-cost personal cooling in hot humid offices

    DEFF Research Database (Denmark)

    Gunnarsen, Lars Bo; Santos, A.

    This report presents a low cost solution to avoid heat stress in a hot and humid environment based on a solar powered drying of supply air. The air drying facilities and a validation of the benefits through comprehensive human exposure studies are described. The study represents an example...... of applied participative research performed in a developing country. The report may be used as a background for the improvement of the indoor climate in poor, hot and humid regions without increased use of electricity....

  5. [Labor environment and heatstroke].

    Science.gov (United States)

    Nagata, Isao

    2012-06-01

    The Ministry of Health, Labour and Welfare and the Heatstroke STUDY 2008 & 2010 regarding the characteristics of laborers who suffered and died from heatstroke demonstrated the involvement of more laborers who worked in construction, from July to August and at around 3 p.m. Also, more laborers who worked at around 11 a.m. got heatstroke, and there were more laborers who died from it within 1 week from starting to work. The results showed that the heat environment and the time and period when laborers started to be exposed to a hot environment adversely effect the development of heatstroke and subsequent heatstroke-related death. It is important to estimate and take measures against a hot environment and to make time to be acclimated to a hot environment.

  6. Cell pairing ratio controlled micro-environment with valve-less electrolytic isolation

    KAUST Repository

    Chen, Yu-Chih

    2012-01-01

    We present a ratio controlled cell-to-cell interaction chip using valve-less isolation. We incorporated electrolysis in a microfluidic channel. In each microfluidic chamber, we loaded two types of different cells at various pairing ratios. More than 80% of the microchambers were successfully loaded with a specific target pairing ratio. For the proof of concept, we have demonstrated the cell-to-cell interaction between prostate cancer cells and muscle stem cells can be controlled by cell pairing ratios through growth factor secretion. The experimental data shows that sealing of microenvironment by air generated from electrolysis does not affect cell viability and cell interaction assay results. © 2012 IEEE.

  7. Navigation of a car-like mobile robot using a decomposition of the environment in convex cells

    Energy Technology Data Exchange (ETDEWEB)

    Vasseur, H.A.; Pin, F.G. (Oak Ridge National Lab., TN (USA)); Taylor, J.R. (Oak Ridge Y-12 Plant, TN (USA))

    1990-01-01

    Due to their kinematics, car-like mobile robots cannot follow an arbitrary path. Besides obstacle avoidance, the path planning problem for such platforms has to satisfy two additional constraints: a lower bounded radius of turn, and a non holonomic constraint. When the robot is not circular, precise maneuvering always implies working in the configuration space of the vehicle. Due to the complexity of the problem, the planning of a path involves computer intensive methods, and rarely allows for real time applications. However, in a convex polygonal cell, maneuvering can be completely handled within geometric reasoning. In this simplified environment, joining two configurations may require maneuvers only at the beginning and at the end of the trajectory. The method consists of computing the possible maneuvers either starting from the initial configuration, or arriving at the final configuration. Just a few boundary configurations have to be checked to avoid collision. Maneuvers related to the initial configuration and to the final configuration can be connected by a straight trajectory because of the convexity of the cell, which allows precise maneuvering computation, without using the whole configuration space. We describe a general environment by means of a graph connecting overlapping convex cells. To find a path between two configurations, the graph is searched in order to list the cells that have to be traversed. Then, intermediate configurations are computed inside the intersection of two adjacent cells. Finally, the trajectories generated inside each cell are assembled to produce global collision free paths in complex environments. 9 refs., 10 figs.

  8. Optimized temperature control system integrated into a micro direct methanol fuel cell for extreme environments

    Science.gov (United States)

    Zhang, Qian; Wang, Xiaohong; Zhu, Yiming; Zhou, Yan'an; Qiu, Xinping; Liu, Litian

    This paper reports a micro direct methanol fuel cell (μDMFC) integrated with a heater and a temperature sensor to realize temperature control. A thermal model for the μDMFC is set up based on heat transfer and emission mechanisms. Several patterns of the heater are designed and simulated to produce a more uniform temperature profile. The μDMFC with optimized temperature control system, which has better temperature distribution, is fabricated by using MEMS technologies, assembled with polydimethylsiloxane (PDMS) material and polymethylmethacrylate (PMMA) holders, and characterized in two methods, one with different currents applied and another with different methanol velocities. A μDMFC integrated with the heater of different pattern and another one with aluminum holders, are assembled and tested also to verify the heating effect and temperature maintaining of packaging material. This work would make it possible for a μDMFC to enhance the performance by adjusting to an optimal temperature and employ in extreme environments, such as severe winter, polar region, outer space, desert and deep sea area.

  9. Hot skull: Malignant or feminine

    Energy Technology Data Exchange (ETDEWEB)

    Roos, J.C.; Isslet, J.W. van; Buul, M.M.C. van; Oei, H.Y.; Rijk, P.P. van

    1987-07-01

    Diffusely increased uptake in the calvarium on bone scintigraphy (a hot skull) is often present in patients with bone metastases and metabolic diseases. Excluding these known facts the prevalence of the hot skull and its relation with malignancy and, more specifically, with breast carcinoma have been studied in 673 patients. In women, the hot skull is clearly related to malignancy and to a lesser extent to breast carcinoma. However, another remarkable feature of the hot skull is its predominance in women in general (compared to men) and, therefore, the data suggest that the hot skull can also represent a normal variant of the female skull. We conclude that the hot skull has no clinical value in screening protocols.

  10. Enriched environment increases the total number of CNPase positive cells in the corpus callosum of middle-aged rats.

    Science.gov (United States)

    Zhao, Yuan-Yu; Shi, Xiao-Yan; Qiu, Xuan; Zhang, Lei; Lu, Wei; Yang, Shu; Li, Chen; Cheng, Guo-Hua; Yang, Zheng-Wei; Tang, Yong

    2011-01-01

    It had been reported that enriched environment was beneficial for the brain cognition, neurons and synapses in cortex and hippocampus. With diffusion tensor imaging (DTI), several studies recently found the trained-induced larger corpus callosum. However, the effect of enriched environment on the oligodendrocytes in corpus callosum has not been explored with the unbiased stereological methods. In current study, the effect of enriched environment on the total number of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) positive cells in middle-aged rat corpus callosum was investigated by means of immunohistochemical techniques and the unbiased stereological methods. We found that, when compared to standard rats, the spatial learning capacity of enriched-environment rats was significantly increased. The total number of the CNPase positive cells in the corpus callosum of enriched-environment middle-aged rats was significantly increased when compared to standard rats. The present study provided, to the best of our knowledge, the first evidence of environmental enrichment-induced increases in the total number of CNPase positive cells in the corpus callosum of middle-aged rats.

  11. Hot, Dry and Cloudy

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Hot, Dry and Cloudy This artist's concept shows a cloudy Jupiter-like planet that orbits very close to its fiery hot star. NASA's Spitzer Space Telescope was recently used to capture spectra, or molecular fingerprints, of two 'hot Jupiter' worlds like the one depicted here. This is the first time a spectrum has ever been obtained for an exoplanet, or a planet beyond our solar system. The ground-breaking observations were made with Spitzer's spectrograph, which pries apart infrared light into its basic wavelengths, revealing the 'fingerprints' of molecules imprinted inside. Spitzer studied two planets, HD 209458b and HD 189733b, both of which were found, surprisingly, to have no water in the tops of their atmospheres. The results suggest that the hot planets are socked in with dry, high clouds, which are obscuring water that lies underneath. In addition, HD209458b showed hints of silicates, suggesting that the high clouds on that planet contain very fine sand-like particles. Capturing the spectra from the two hot-Jupiter planets was no easy feat. The planets cannot be distinguished from their stars and instead appear to telescopes as single blurs of light. One way to get around this is through what is known as the secondary eclipse technique. In this method, changes in the total light from a so-called transiting planet system are measured as a planet is eclipsed by its star, vanishing from our Earthly point of view. The dip in observed light can then be attributed to the planet alone. This technique, first used by Spitzer in 2005 to directly detect the light from an exoplanet, currently only works at infrared wavelengths, where the differences in brightness between the planet and star are less, and the planet's light is easier to pick out. For example, if the experiment had been done in visible light, the total light from the system would appear to be unchanged, even as the planet

  12. Study on the Preparation Process and Influential Factors of Large Area Environment-friendly Molten Carbonate Fuel Cell Matrix

    Science.gov (United States)

    Zhang, Ruiyun; Xu, Shisen; Cheng, Jian; Wang, Hongjian; Ren, Yongqiang

    2017-07-01

    Low-cost and high-performance matrix materials used in mass production of molten carbonate fuel cell (MCFC) were prepared by automatic casting machine with α-LiAlO2 powder material synthesized by gel-solid method, and distilled water as solvent. The single cell was assembled for generating test, and the good performance of the matrix was verified. The paper analyzed the factors affecting aqueous tape casting matrix preparation, such as solvent content, dispersant content, milling time, blade height and casting machine running speed, providing a solid basis for the mass production of large area environment-friendly matrix used in molten carbonate fuel cell.

  13. Adaptation of ovarian cancer cells to the peritoneal environment: Multiple mechanisms of the developmental patterning gene HOXA9.

    Science.gov (United States)

    Ko, Song Yi; Naora, Honami

    2014-11-13

    The lethality of ovarian cancer stems from its propensity to involve the peritoneal cavity. However, the mechanisms that enable ovarian cancer cells to readily adapt to the peritoneal environment are not well understood. Here, we describe our recent studies in which we identified the mechanisms by which the transcription factor encoded by the patterning gene HOXA9 promotes the aggressive behavior of ovarian cancer. Firstly, we identified that HOXA9 promotes ovarian tumor growth and angiogenesis by activating the gene encoding transforming growth factor-β2 (TGF-β2), which in turn stimulates peritoneal fibroblasts and mesenchymal stem cells to acquire features of cancer-associated fibroblasts. Secondly, by inducing TGF-β2 and chemokine (C-C motif) ligand 2, HOXA9 stimulates peritoneal macrophages to acquire an immunosuppressive phenotype. Thirdly, HOXA9 stimulates attachment of ovarian cancer cells to peritoneal mesothelial cells by inducing expression of P-cadherin. By inducing P-cadherin, HOXA9 also enables floating cancer cells in the peritoneal cavity to form aggregates and escape anoikis. Together, our studies demonstrate that HOXA9 enables ovarian cancer cells to adapt to the peritoneal environment and 'educates' different types of stromal cells to become permissive for tumor growth. Our studies provide new insights into the regulation of tumor-stroma interactions in ovarian cancer and implicate several key effector molecules as candidate therapeutic targets.

  14. Aβ and inflammatory stimulus activate diverse signaling pathways in monocytic cells: implications in retaining phagocytosis in Aβ-laden environment

    Directory of Open Access Journals (Sweden)

    Ekaterina Savchenko

    2016-12-01

    Full Text Available Background Accumulation of amyloid β (Aβ is one of the main hallmarks of Alzheimer’s disease (AD. The enhancement of Aβ clearance may provide therapeutic means to restrict AD pathology. The cellular responses to different forms of Aβ in monocytic cells are poorly known. We aimed to study whether different forms of Aβ induce inflammatory responses in monocytic phagocytes and how Aβ may affect monocytic cell survival and function to retain phagocytosis in Aβ-laden environment. Methods Monocytic cells were differentiated from bone marrow hematopoietic stem cells in the presence of macrophage-colony stimulating factor. Monocytic cells were stimulated with synthetic Aβ42 and intracellular calcium responses were recorded with calcium imaging. The formation of reactive oxygen species, secretion of cytokines and cell viability were also assessed. Finally, monocytic cells were introduced to native Aβ deposits ex vivo and the cellular responses in terms of cell viability, pro-inflammatory activation and phagocytosis were determined. The ability of monocytic cells to phagocytose Aβ plaques was determined after intrahippocampal transplantation in vivo.Results Freshly solubilized Aβ induced calcium oscillations, which persisted after removal of the stimulus. After few hours of aggregation, Aβ was not able to induce oscillations in monocytic cells. Instead, lipopolysaccharide (LPS induced calcium responses divergent from Aβ-induced response. Furthermore, while LPS induced massive production of pro-inflammatory cytokines, neither synthetic Aβ species nor native Aβ deposits were able to induce pro-inflammatory activation of monocytic cells, contrary to primary microglia. Finally, monocytic cells retained their viability in the presence of Aβ and exhibited phagocytic activity towards native fibrillar Aβ deposits and congophilic Aβ plaques.Conclusions Monocytic cells carry diverse cellular responses to Aβ and inflammatory stimulus LPS. Even

  15. NaviCell: a web-based environment for navigation, curation and maintenance of large molecular interaction maps.

    Science.gov (United States)

    Kuperstein, Inna; Cohen, David P A; Pook, Stuart; Viara, Eric; Calzone, Laurence; Barillot, Emmanuel; Zinovyev, Andrei

    2013-10-07

    Molecular biology knowledge can be formalized and systematically represented in a computer-readable form as a comprehensive map of molecular interactions. There exist an increasing number of maps of molecular interactions containing detailed and step-wise description of various cell mechanisms. It is difficult to explore these large maps, to organize discussion of their content and to maintain them. Several efforts were recently made to combine these capabilities together in one environment, and NaviCell is one of them. NaviCell is a web-based environment for exploiting large maps of molecular interactions, created in CellDesigner, allowing their easy exploration, curation and maintenance. It is characterized by a combination of three essential features: (1) efficient map browsing based on Google Maps; (2) semantic zooming for viewing different levels of details or of abstraction of the map and (3) integrated web-based blog for collecting community feedback. NaviCell can be easily used by experts in the field of molecular biology for studying molecular entities of interest in the context of signaling pathways and crosstalk between pathways within a global signaling network. NaviCell allows both exploration of detailed molecular mechanisms represented on the map and a more abstract view of the map up to a top-level modular representation. NaviCell greatly facilitates curation, maintenance and updating the comprehensive maps of molecular interactions in an interactive and user-friendly fashion due to an imbedded blogging system. NaviCell provides user-friendly exploration of large-scale maps of molecular interactions, thanks to Google Maps and WordPress interfaces, with which many users are already familiar. Semantic zooming which is used for navigating geographical maps is adopted for molecular maps in NaviCell, making any level of visualization readable. In addition, NaviCell provides a framework for community-based curation of maps.

  16. The preparation, characterization, and application of environment-friendly monoclonal antibodies for human blood cell.

    Science.gov (United States)

    Zhou, Chenjie; Gao, Xuechao; He, Shixiang; Gao, Xiaoling; Zhuang, Jialin; Huang, Lirong; Guo, Hengchang

    2017-03-01

    Monoclonal anti-human blood group A (51A8) and B (63B6) antibody reagents were prepared using the serum-free technique. The aims of this research were to characterize the serum-free reagents and prove their reliabilities in routine use. Experiments including antigen-antibody agglutination testing, stability testing, SDS-PAGE, protein and IgM quantification, flow cytometry, and variable domain sequencing were performed to characterize the anti-A (51A8) and anti-B (63B6) reagents. Over 12 000 samples were tested using these reagents as routine blood grouping reagents. Serum-free anti-A (51A8) and anti-B (63B6) reagents were stable in longitudinal and accelerated testing, and their high purity was shown in SDS-PAGE and IgM quantification. These reagents have high specificity to red blood cells in serologic agglutination testing and flow cytometric analysis. A1 and A2 subgroup antigens can be distinguished clearly by patterns of flow cytometric histograms. No discrepancy was found in clinical trials of 12 000 samples. To reduce the risk of being affected by any animal additives, a serum-free culture system was applied to get mass-production of monoclonal anti-A/B antibodies. The high specificity and the high purity of the reagents were verified by the lab experiments. Lab research and clinical trial showed that serum-free monoclonal anti-A (51A8) and anti-B (63B6) reagents meet the requirements of routine blood grouping reagents. Moreover, these reagents featured ultra-high purity that is missing in other commercial counterparts, and therefore are recommended as more environment-friendly reagents.

  17. Three dimensional Particle-in-Cell (PIC) simulations of the 67P environment

    Science.gov (United States)

    Divin, Andrey; Deca, Jan; Henri, Pierre; Horanyi, Mihaly; Markidis, Stefano; Lapenta, Giovanni; Olshevsky, Vyacheslav; Eriksson, Anders

    2017-04-01

    ESA's Rosetta orbiter spacecraft escorted comet 67P/Churyumov-Gerasimenko for two years, carrying 21 scientific instruments. Five of those were dedicated to plasma measurements. The mission revealed for the first time, and in unprecedented detail, the fascinating evolution of a comet and its interaction with our Sun as it races along its 6.45yr elliptical orbit around the Sun. Using a self-consistent 3-D fully kinetic electromagnetic particle-in-cell approach, we focus on the global cometary environment and, in particular, on the collisionless electron-kinetic interaction. We include cometary ions and electrons produced by the ionization of the outgassing cometary atmosphere in addition to the solar wind ion and electron plasma flow. We approximate mass-loading of the cold cometary ion and electron populations using a 1/r relation with distance to the comet with a total neutral production rate of Q = 1026 s-1. Our simulation results disentangle for the first time the kinetic ion and electron dynamics of the solar wind interaction with a weakly outgassing comet. The simulated global structure of the solar wind-comet interaction confirms the results reported in hybrid simulations of the induced cometary magnetosphere. Moreover, we show that cometary and solar wind electrons neutralize the solar wind protons and cometary ions, respectively, in the region of influence around the comet, representing to first order a four-fluid behavior. The electron energy distribution close to the comet is shown to be a mix of cometary and solar wind electrons that appear as, respectively, a thermal and a suprathermal components. Analyzing ion and electron energy distribution functions, and comparing with plasma measurements from ESA's Rosetta mission to comet 67P/Churyumov-Gerasimenko, we conclude that a detailed kinetic treatment of the electron dynamics is critical to fully capture the complex physics of mass-loading plasmas.

  18. Enriching the Housing Environment for Mice Enhances Their NK Cell Antitumor Immunity via Sympathetic Nerve-Dependent Regulation of NKG2D and CCR5.

    Science.gov (United States)

    Song, Yanfang; Gan, Yu; Wang, Qing; Meng, Zihong; Li, Guohua; Shen, Yuling; Wu, Yufeng; Li, Peiying; Yao, Ming; Gu, Jianren; Tu, Hong

    2017-04-01

    Mice housed in an enriched environment display a tumor-resistant phenotype due to eustress stimulation. However, the mechanisms underlying enriched environment-induced protection against cancers remain largely unexplained. In this study, we observed a significant antitumor effect induced by enriched environment in murine pancreatic cancer and lung cancer models. This effect remained intact in T/B lymphocyte-deficient Rag1 -/- mice, but was nearly eliminated in natural killer (NK) cell-deficient Beige mice or in antibody-mediated NK-cell-depleted mice, suggesting a predominant role of NK cells in enriched environment-induced tumor inhibition. Exposure to enriched environment enhanced NK-cell activity against tumors and promoted tumoral infiltration of NK cells. Enriched environment increased the expression levels of CCR5 and NKG2D (KLRK1) in NK cells; blocking their function effectively blunted the enriched environment-induced enhancement of tumoral infiltration and cytotoxic activity of NK cells. Moreover, blockade of β-adrenergic signaling or chemical sympathectomy abolished the effects of enriched environment on NK cells and attenuated the antitumor effect of enriched environment. Taken together, our results provide new insight into the mechanism by which eustress exerts a beneficial effect against cancer. Cancer Res; 77(7); 1611-22. ©2017 AACR . ©2017 American Association for Cancer Research.

  19. Software Simulation of Hot Tearing

    DEFF Research Database (Denmark)

    Andersen, S.; Hansen, P.N.; Hattel, Jesper Henri

    1999-01-01

    . With this additional information, the criteria can, for the first time, be used to their full potential.The purpose of this paper is to first give an introduction to a stress/strain simulation procedure that can be used in any foundry. Then, some results how to predict the hot cracking tendency in a casting are shown......The brittleness of a solidifying alloy in a temperature range near the solidus temperature has been recognised since the fifties as the mechanism responsible for hot tearing. Due to this brittlenes, the metal will crack under even small amounts of strain in that temperature range. We see these hot...... the solidification rate and the strain rate of the hot tear prone areas. But, until recently it was only possible to simulate the solidification rate, so that the criteria could not be used effectively.Today, with new software developments, it is possible to also simulate the strain rate in the hot tear prone areas...

  20. Superoxide triggers an acid burst in Saccharomyces cerevisiae to condition the environment of glucose-starved cells.

    Science.gov (United States)

    Baron, J Allen; Laws, Kaitlin M; Chen, Janice S; Culotta, Valeria C

    2013-02-15

    Although yeast cells grown in abundant glucose tend to acidify their extracellular environment, they raise the pH of the environment when starved for glucose or when grown strictly with non-fermentable carbon sources. Following prolonged periods in this alkaline phase, Saccharomyces cerevisiae cells will switch to producing acid. The mechanisms and rationale for this "acid burst" were unknown. Herein we provide strong evidence for the role of mitochondrial superoxide in initiating the acid burst. Yeast mutants lacking the mitochondrial matrix superoxide dismutase (SOD2) enzyme, but not the cytosolic Cu,Zn-SOD1 enzyme, exhibited marked acceleration in production of acid on non-fermentable carbon sources. Acid production is also dramatically enhanced by the superoxide-producing agent, paraquat. Conversely, the acid burst is eliminated by boosting cellular levels of Mn-antioxidant mimics of SOD. We demonstrate that the acid burst is dependent on the mitochondrial aldehyde dehydrogenase Ald4p. Our data are consistent with a model in which mitochondrial superoxide damage to Fe-S enzymes in the tricarboxylic acid (TCA) cycle leads to acetate buildup by Ald4p. The resultant expulsion of acetate into the extracellular environment can provide a new carbon source to glucose-starved cells and enhance growth of yeast. By triggering production of organic acids, mitochondrial superoxide has the potential to promote cell population growth under nutrient depravation stress.

  1. The acute environment, rather than T cell subset pre-commitment, regulates expression of the human T cell cytokine amphiregulin.

    Directory of Open Access Journals (Sweden)

    Yilin Qi

    Full Text Available Cytokine expression patterns of T cells can be regulated by pre-commitment to stable effector phenotypes, further modification of moderately stable phenotypes, and quantitative changes in cytokine production in response to acute signals. We showed previously that the epidermal growth factor family member Amphiregulin is expressed by T cell receptor-activated mouse CD4 T cells, particularly Th2 cells, and helps eliminate helminth infection. Here we report a detailed analysis of the regulation of Amphiregulin expression by human T cell subsets. Signaling through the T cell receptor induced Amphiregulin expression by most or all T cell subsets in human peripheral blood, including naive and memory CD4 and CD8 T cells, Th1 and Th2 in vitro T cell lines, and subsets of memory CD4 T cells expressing several different chemokine receptors and cytokines. In these different T cell types, Amphiregulin synthesis was inhibited by an antagonist of protein kinase A, a downstream component of the cAMP signaling pathway, and enhanced by ligands that increased cAMP or directly activated protein kinase A. Prostaglandin E2 and adenosine, natural ligands that stimulate adenylyl cyclase activity, also enhanced Amphiregulin synthesis while reducing synthesis of most other cytokines. Thus, in contrast to mouse T cells, Amphiregulin synthesis by human T cells is regulated more by acute signals than pre-commitment of T cells to a particular cytokine pattern. This may be appropriate for a cytokine more involved in repair than attack functions during most inflammatory responses.

  2. Hot Spot Mutation in TP53 (R248Q Causes Oncogenic Gain-of-Function Phenotypes in a Breast Cancer Cell Line Derived from an African American patient

    Directory of Open Access Journals (Sweden)

    Nataly Shtraizent

    2015-12-01

    Full Text Available African American (AA breast cancer patients often have triple negative breast cancer (TNBC that contains mutations in the TP53 gene. The point mutations at amino acid residues R273 and R248 both result in oncogenic gain-of-function (GOF phenotypes. Expression of mutant p53 (mtp53 R273H associates with increased cell elasticity, survival under serum deprivation conditions, and increased Poly (ADP ribose polymerase 1 (PARP1 on the chromatin in the AA-derived TNBC breast cancer cell line MDA-MB-468. We hypothesized that GOF mtp53 R248Q expression could stimulate a similar phenotype in the AA-derived TNBC cell line HCC70. To test this hypothesis we depleted the R248Q protein in the HCC70 cell line using shRNA-mediated knockdown. Using impedance-based real-time analysis we correlated the expression of mtp53 R248Q with increased cell deformability. We also documented that depletion of mtp53 R248Q increased PARP1 in the cytoplasm and decreased PARP1 on the chromatin. We conclude that in the AA-derived TNBC HCC70 cells mtp53 R248Q expression results in a causative tumor associated phenotype. This study supports using the biological markers of high expression of mtp53 R273H or R248Q as additional diagnostics for TNBC resistant subtypes often found in the AA community. Each mtp53 protein must be considered separately and this work adds R248Q to the increasing list of p53 mutations that can be used for diagnostics and drug targeting. Here we report that when R248Q mtp53 proteins are expressed in TNBC, then targeting the gain-of-function pathways may improve treatment efficacy.

  3. Hot Spot Cosmic Accelerators

    Science.gov (United States)

    2002-11-01

    length of more than 3 million light-years, or no less than one-and-a-half times the distance from the Milky Way to the Andromeda galaxy, this structure is indeed gigantic. The region where the jets collide with the intergalactic medium are known as " hot spots ". Superposing the intensity contours of the radio emission from the southern "hot spot" on a near-infrared J-band (wavelength 1.25 µm) VLT ISAAC image ("b") shows three distinct emitting areas; they are even better visible on the I-band (0.9 µm) FORS1 image ("c"). This emission is obviously associated with the shock front visible on the radio image. This is one of the first times it has been possible to obtain an optical/near-IR image of synchrotron emission from such an intergalactic shock and, thanks to the sensitivity and image sharpness of the VLT, the most detailed view of its kind so far . The central area (with the strongest emission) is where the plasma jet from the galaxy centre hits the intergalactic medium. The light from the two other "knots", some 10 - 15,000 light-years away from the central "hot spot", is also interpreted as synchrotron emission. However, in view of the large distance, the astronomers are convinced that it must be caused by electrons accelerated in secondary processes at those sites . The new images thus confirm that electrons are being continuously accelerated in these "knots" - hence called "cosmic accelerators" - far from the galaxy and the main jets, and in nearly empty space. The exact physical circumstances of this effect are not well known and will be the subject of further investigations. The present VLT-images of the "hot spots" near 3C 445 may not have the same public appeal as some of those beautiful images that have been produced by the same instruments during the past years. But they are not less valuable - their unusual importance is of a different kind, as they now herald the advent of fundamentally new insights into the mysteries of this class of remote and active

  4. Archaeal diversity in Icelandic hot springs

    DEFF Research Database (Denmark)

    Kvist, Thomas; Ahring, Birgitte Kiær; Westermann, Peter

    2007-01-01

    of Archaea by analysis of amplified 16S rRNA genes. In addition to the three solfataras and the neutral hot spring, 10 soil samples in transects of the soil adjacent to the solfataras were analysed using terminal restriction fragment length polymorphism (t-RFLP). The sequence data from the clone libraries...... in combination with 14 t-RFLP profiles revealed a high abundance of clones clustering together with sequences from the nonthermophilic I.1b group of Crenarchaeota. The archaeal diversity in one solfatara was high; 26 different RFLP patterns were found using double digestion of the PCR products with restriction......Whole-cell density gradient extractions from three solfataras (pH 2.5) ranging in temperature from 81 to 90 degrees C and one neutral hot spring (81 degrees C, pH 7) from the thermal active area of Hveragerethi (Iceland) were analysed for genetic diversity and local geographical variation...

  5. Really Hot Stars

    Science.gov (United States)

    2003-04-01

    Spectacular VLT Photos Unveil Mysterious Nebulae Summary Quite a few of the most beautiful objects in the Universe are still shrouded in mystery. Even though most of the nebulae of gas and dust in our vicinity are now rather well understood, there are some which continue to puzzle astronomers. This is the case of a small number of unusual nebulae that appear to be the subject of strong heating - in astronomical terminology, they present an amazingly "high degree of excitation". This is because they contain significant amounts of ions, i.e., atoms that have lost one or more of their electrons. Depending on the atoms involved and the number of electrons lost, this process bears witness to the strength of the radiation or to the impact of energetic particles. But what are the sources of that excitation? Could it be energetic stars or perhaps some kind of exotic objects inside these nebulae? How do these peculiar objects fit into the current picture of universal evolution? New observations of a number of such unusual nebulae have recently been obtained with the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). In a dedicated search for the origin of their individual characteristics, a team of astronomers - mostly from the Institute of Astrophysics & Geophysics in Liège (Belgium) [1] - have secured the first detailed, highly revealing images of four highly ionized nebulae in the Magellanic Clouds, two small satellite galaxies of our home galaxy, the Milky Way, only a few hundred thousand light-years away. In three nebulae, they succeeded in identifying the sources of energetic radiation and to eludicate their exceptional properties: some of the hottest, most massive stars ever seen, some of which are double. With masses of more than 20 times that of the Sun and surface temperatures above 90 000 degrees, these stars are truly extreme. PR Photo 09a/03: Nebula around the hot star AB7 in the SMC. PR Photo 09b/03: Nebula near the hot Wolf-Rayet star BAT99

  6. Preliminary report for the license of a hot cell that will be use in the technology development for the obtention of Mo-99; Informe preliminar para la licencia de una celda caliente que se utilizara en el desarrollo de la tecnologia para la obtencion de Mo-99

    Energy Technology Data Exchange (ETDEWEB)

    Fucugauchi, L.A.; Millan S, S.; Lopez M, A.E.; Lopez C, R; Sanchez M, V.; Reynoso V, R.; Vera, A

    1991-05-15

    A preliminary report for the license of a hot cell that will be used in the development of the technology for the obtaining of Mo-99 is presented. The following topics are also included: objective of the project, technical description, description of the prototype cell, handling of radioactive wastes, lists of equipment that will be used, risk analysis, curricula, quality assurance plan and an annex with the report on handling of radioactive wastes presented to the PAGD-IAEA. (Author)

  7. Observational signatures of hot-star magnetospheres

    Science.gov (United States)

    Oksala, Mary E.

    2017-11-01

    Magnetic fields play an important role in shaping the circumstellar environment of hot, massive stars. Observational diagnostics give clues to the presence of magnetism across the entire electromagnetic spectrum. Infrared features can show more complex structure, indicating they may probe deeper opacities than optical features. Optical and infrared features mimic each other, with identical blue and red peak variations and identical peak velocity of material. These comparisons indicate the location of the infrared and optical emitting material is similar. Longer wavelength diagnostics are currently being developed and tested. IR spectroscopy is a viable tool to detect magnetic candidates in the Galactic center and star forming regions.

  8. Hot-Dipped Metal Films as Epitaxial Substrates

    Science.gov (United States)

    Shlichta, P. J.

    1985-01-01

    Multistep process forms semiconductor devices on macrocrystalline films of cadmium or zinc. Solar-cell fabrication processes use hot-dipped macrocrystalline films on low-cost sheet-metal base as substrates for epitaxy. Epitaxial layers formed by variety of methods of alternative sequence paths. Solar cells made economically by forming desired surface substance directly on metal film by chemical reactions.

  9. Hot Hydrogen Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    W. David Swank

    2007-02-01

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISp. This quantity is proportional to the square root of the propellant’s absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500°C hydrogen flowing at 1500 liters per minute. The facility is intended to test non-uranium containing materials and therefore is particularly suited for testing potential cladding and coating materials. In this first installment the facility is described. Automated Data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  10. Neptune's 'Hot' South Pole

    Science.gov (United States)

    2007-01-01

    These thermal images show a 'hot' south pole on the planet Neptune. These warmer temperatures provide an avenue for methane to escape out of the deep atmosphere. The images were obtained with the Very Large Telescope in Chile, using an imager/spectrometer for mid-infrared wavelengths on Sept. 1 and 2, 2006. The telescope is operated by the European Organization for Astronomical Research in the Southern Hemisphere (known as ESO). Scientists say Neptune's south pole is 'hotter' than anywhere else on the planet by about 10 degrees Celsius (50 degrees Fahrenheit). The average temperature on Neptune is about minus 200 degrees Celsius (minus 392 degrees Fahrenheit). The upper left image samples temperatures near the top of Neptune's troposphere (near 100 millibar pressure, which is one-tenth the Earth atmospheric pressure at sea level). The hottest temperatures are indicated at the lower part of the image, at Neptune's south pole (see the graphic at the upper right). The lower two images, taken 6.3 hours apart, sample temperatures at higher altitudes in Neptune's stratosphere. They do show generally warmer temperatures near, but not at, the south pole. They also show a distinct warm area which can be seen in the lower left image and rotated completely around the back of the planet and returned to the earth-facing hemisphere in the lower right image.

  11. Solutions for Hot Situations

    Science.gov (United States)

    2003-01-01

    From the company that brought the world an integral heating and cooling food service system after originally developing it for NASA's Apollo Program, comes yet another orbital offshoot: a product that can be as thin as paper and as strong as steel. Nextel Ceramic Textiles and Composites from 3M Company offer space-age protection and innovative solutions for hot situations, ranging from NASA to NASCAR. With superior thermal protection, Nextel fabrics, tape, and sleevings outperform other high temperature textiles such as aramids, carbon, glass, and quartz, permitting engineers and manufacturers to handle applications up to 2,500 F (1,371 C). The stiffness and strength of Nextel Continuous Ceramic Fibers make them a great match for improving the rigidity of aluminum in metal matrix composites. Moreover, the fibers demonstrate low shrinkage at operating temperatures, which allow for the manufacturing of a dimensionally stable product. These novel fibers also offer excellent chemical resistance, low thermal conductivity, thermal shock resistance, low porosity, and unique electrical properties.

  12. Environment dictates dependence on mitochondrial complex I for NAD+ and aspartate production and determines cancer cell sensitivity to metformin

    OpenAIRE

    Gui, Dan Y.; Sullivan, Lucas B.; Luengo, Alba; Hosios, Aaron M.; Bush, Lauren N.; Gitego, Nadege; Davidson, Shawn M.; Freinkman, Elizaveta; Thomas, Craig J.; Vander Heiden, Matthew G.

    2016-01-01

    Metformin use is associated with reduced cancer mortality, but how metformin impacts cancer outcomes is controversial. While metformin can act cell autonomously to inhibit tumor growth, the doses of metformin that inhibit proliferation in tissue culture are much higher than what has been described in vivo. Here, we show that environment drastically alters sensitivity to metformin and other complex I inhibitors. We find that complex I supports proliferation by regenerating NAD+, and metformin’...

  13. Anti-proliferative effects of Salacia reticulata leaves hot-water extract on interleukin-1β-activated cells derived from the synovium of rheumatoid arthritis model mice

    OpenAIRE

    Sekiguchi Yuusuke; Mano Hiroshi; Nakatani Sachie; Shimizu Jun; Kobata Kenji; Wada Masahiro

    2012-01-01

    Abstract Background Salacia reticulata (SR) is a plant native to Sri Lanka. In ayurvedic medicine, SR bark preparations, taken orally, are considered effective in the treatment of rheumatism and diabetes. We investigated the ability of SR leaves (SRL) to inhibit in vitro the interleukin-1β (IL-1β)-activated proliferation of synoviocyte-like cells derived from rheumatoid arthritis model mice. Findings Inflammatory synovial tissues were harvested from type II collagen antibody-induced arthritic...

  14. Effect of microgravity environment on cell wall regeneration, cell divisions, growth, and differentiation of plants from protoplasts (7-IML-1)

    Science.gov (United States)

    Rasmussen, Ole

    1992-01-01

    The primary goal of this project is to investigate if microgravity has any influence on growth and differentiation of protoplasts. Formation of new cell walls on rapeseed protoplasts takes place within the first 24 hours after isolation. Cell division can be observed after 2-4 days and formation of cell aggregates after 5-7 days. Therefore, it is possible during the 7 day IML-1 Mission to investigate if cell wall formation, cell division, and cell differentiation are influenced by microgravity. Protoplasts of rapeseeds and carrot will be prepared shortly before launch and injected into 0.6 ml polyethylene bags. Eight bags are placed in an aluminum block inside the ESA Type 1 container. The containers are placed at 4 C in PTCU's and transferred to orbiter mid-deck. At 4 C all cell processes are slowed down, including cell wall formation. Latest access to the shuttle will be 12 hours before launch. In orbit the containers will be transferred from the PTC box to the 22 C Biorack incubator. The installation of a 1 g centrifuge in Biorack will make it possible to distinguish between effects of near weightlessness and effects caused by cosmic radiation and other space flight factors including vibrations. Parallel control experiments will be carried out on the ground. Other aspects of the experiment are discussed.

  15. Targeting cholesterol in a liquid-disordered environment by theonellamides modulates cell membrane order and cell shape.

    Science.gov (United States)

    Arita, Yuko; Nishimura, Shinichi; Ishitsuka, Reiko; Kishimoto, Takuma; Ikenouchi, Junichi; Ishii, Kumiko; Umeda, Masato; Matsunaga, Shigeki; Kobayashi, Toshihide; Yoshida, Minoru

    2015-05-21

    Roles of lipids in the cell membrane are poorly understood. This is partially due to the lack of methodologies, for example, tool chemicals that bind to specific membrane lipids and modulate membrane function. Theonellamides (TNMs), marine sponge-derived peptides, recognize 3β-hydroxysterols in lipid membranes and induce major morphological changes in cultured mammalian cells through as yet unknown mechanisms. Here, we show that TNMs recognize cholesterol-containing liquid-disordered domains and induce phase separation in model lipid membranes. Modulation of membrane order was also observed in living cells following treatment with TNM-A, in which cells shrank considerably in a cholesterol-, cytoskeleton-, and energy-dependent manner. These findings present a previously unrecognized mode of action of membrane-targeting natural products. Meanwhile, we demonstrated the importance of membrane order, which is maintained by cholesterol, for proper cell morphogenesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Proteomic signature of arabidopsis cell cultures exposed to magnetically induced hyper- and microgravity environments

    NARCIS (Netherlands)

    Herranz, R.; Manzano, A.I.; van Loon, J.J.W.A.; Christianen, P.C.M.; Medina, F.J.

    2013-01-01

    Earth-based microgravity simulation techniques are required due to space research constraints. Using diamagnetic levitation, we exposed Arabidopsis thaliana in vitro callus cultures to environments with different levels of effective gravity and magnetic field strengths (B) simultaneously. The

  17. The inhibitory influence of adipose tissue-derived mesenchymal stem cell environment and Wnt antagonism on breast tumour cell lines.

    Science.gov (United States)

    Visweswaran, Malini; Arfuso, Frank; Dilley, Rodney J; Newsholme, Philip; Dharmarajan, Arun

    2018-02-01

    Tumours exhibit a heterogeneous mix of cell types that reciprocally regulate their growth in the tumour stroma, considerably affecting the progression of the disease. Both adipose-derived mesenchymal stem cells and Wnt signalling pathway are vital in driving breast tumour growth. Hence, we examined the effect of secreted factors released by adipose-derived mesenchymal stem cells, and further explored the anti-tumour property of the Wnt antagonist secreted frizzled-related protein 4 (sFRP4) on MCF-7 and MDA-MB-231 breast tumour cells. We observed that conditioned medium and extracellular matrix derived from adipose-derived mesenchymal stem cells inhibited tumour viability. The inhibitory effect of the conditioned medium was retained within its low molecular weight and non-protein component. The conditioned medium also induced apoptosis accompanied by a decrease in the mitochondrial membrane potential in tumour cells, Furthermore, it downregulated the protein expression of active β-catenin and Cyclin D1, which are major target proteins of the Wnt signalling pathway, and reduced the expression of anti-apoptotic protein Bcl-xL. The combination of conditioned medium and sFRP4 further potentiated the effects, depending on the tumour cell line and experimental assay. We conclude that factors derived from conditioned medium of adipose-derived mesenchymal stem cells and sFRP4 significantly decreased the tumour cell viability and migration rates (MCF-7), accompanied with an enhanced apoptotic activity through inhibition of canonical Wnt signalling. Besides giving an insight to possible paracrine interactions and influence of signalling pathways, reflective of a breast tumour microenvironment, this study emphasises the utilization of cell free-secreted factors and Wnt antagonists to improve conventional anti-cancer strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Hot workability of magnesium alloys

    Science.gov (United States)

    Mwembela, Aaron Absalom

    For the alloy AZ91 (Mg-9.OAl-0.7Zn-0.13Mn) die cast specimens were subjected to torsion testing at 150, 180, 240, 300, 420 and 450°C at 0.05 0.5 and 5.0 s--1 The as-cast specimens exhibited hot shortness at 360°C and above; however in that domain, after prior thermomechanical processing (TMP) at 300°C, they showed much improved properties (which were reported along with as-cast properties at 300°C and below). For AZ31-Mn (Mg-3.2Al-1-1Zn-0.34Mn), AZ31 (Mg-2-8Al-0-88Zn-0.01Mn), AZ63 (Mg-5-5Al-2.7Zn-0.34Mn) and ZK60 (Mg-5.7Zn-0.65Zr-O-O1A]), the specimens were subjected to hot torsion testing in the range 180 to 450°C and 0.01, 0.1, and 1.0 s--1. In the temperature range below 300°C flow curves rise to a peak with failure occurring immediately thereafter. Above 300°C the flow curves exhibited a peak and a gradual decline towards steady state. The temperature and strain rate dependence of the strength is described by a sinh-Arrhenius equation with QHW between 125 and 144 kJ/mol; this indicates control by climb in comparison with creep in the range 200--400°C. The alloy strength and activation energy declined in the order AZ63, AZ31-Mn AZ91, AZ31 and ZK60, while ductility increased with decreasing strength. In working of Mg alloys from 150 to 450°C, the flow curves harden to a peak and work soften to a steady state regime above 300°C. At temperatures below 300°C, twinning is observed initially to bring grains into more suitable slip orientations. At high T a substructure develops due to basal and prismatic slip, Forming cells of augmented misorientation first near the grain boundaries and later towards the grain cores. Near the peak, new grains appear along the old boundaries (mantle) as a result of dynamic recrystallization DRX but not in the core of the initial grains. As T rises, the new grains are larger and the mantle broader, enhanced DRX results in higher ductility. At intermediate T, shear bands form through alignment of mantle zones resulting in

  19. Underground Adaptation to a hostile environment: Acute Myeloid Leukemia vs. Natural Killer cells

    Directory of Open Access Journals (Sweden)

    Nicolas eDulphy

    2016-03-01

    Full Text Available Acute myeloid leukemia (AML is a heterogeneous group of malignancies which incidence increases with age. The disease affects the differentiation of hematopoietic stem or precursor cells in the bone marrow and can be related to abnormal cytogenetic and/or specific mutational patterns. AML blasts can be sensitive to natural killer (NK cell anti-tumor response. However, NK cells are frequently defective in AML patients leading to tumor escape. NK cell defects affect not only the expression of the activating NK receptors, including the Natural Cytotoxicity Receptors (NCR, the NK group 2, member D (NKG2D and the DNAX accessory molecule-1 (DNAM-1, but also cytotoxicity and IFN-g release. Such perturbations in NK cell physiology could be related to the adaptation of the AML to the immune pressure and more generally to patient's clinical features. Various mechanisms are potentially involved in the inhibition of NK-cell functions in AML including defects in the normal lymphopoiesis, reduced expression of activating receptors through cell-to-cell contacts, and production of immunosuppressive soluble agents by leukemic blasts. Therefore, the continuous cross-talk between AML and NK cells participates to the leukemia immune escape and eventually to patient's relapse. Methods to restore or stimulate NK cells seem to be attractive strategies to treat patients once the complete remission is achieved. Moreover, our capacity in stimulating the NK cell functions could lead to the development of preemptive strategies to eliminate leukemia-initiating cells before the emergence of the disease in elderly individuals presenting pre-leukemic mutations in hematopoietic stem cells.

  20. Perinuclear Arp2/3-driven actin polymerization enables nuclear deformation to facilitate cell migration through complex environments.

    Science.gov (United States)

    Thiam, Hawa-Racine; Vargas, Pablo; Carpi, Nicolas; Crespo, Carolina Lage; Raab, Matthew; Terriac, Emmanuel; King, Megan C; Jacobelli, Jordan; Alberts, Arthur S; Stradal, Theresia; Lennon-Dumenil, Ana-Maria; Piel, Matthieu

    2016-03-15

    Cell migration has two opposite faces: although necessary for physiological processes such as immune responses, it can also have detrimental effects by enabling metastatic cells to invade new organs. In vivo, migration occurs in complex environments and often requires a high cellular deformability, a property limited by the cell nucleus. Here we show that dendritic cells, the sentinels of the immune system, possess a mechanism to pass through micrometric constrictions. This mechanism is based on a rapid Arp2/3-dependent actin nucleation around the nucleus that disrupts the nuclear lamina, the main structure limiting nuclear deformability. The cells' requirement for Arp2/3 to pass through constrictions can be relieved when nuclear stiffness is decreased by suppressing lamin A/C expression. We propose a new role for Arp2/3 in three-dimensional cell migration, allowing fast-moving cells such as leukocytes to rapidly and efficiently migrate through narrow gaps, a process probably important for their function.

  1. Dynamically analyzing cell interactions in biological environments using multiagent social learning framework.

    Science.gov (United States)

    Zhang, Chengwei; Li, Xiaohong; Li, Shuxin; Feng, Zhiyong

    2017-09-20

    Biological environment is uncertain and its dynamic is similar to the multiagent environment, thus the research results of the multiagent system area can provide valuable insights to the understanding of biology and are of great significance for the study of biology. Learning in a multiagent environment is highly dynamic since the environment is not stationary anymore and each agent's behavior changes adaptively in response to other coexisting learners, and vice versa. The dynamics becomes more unpredictable when we move from fixed-agent interaction environments to multiagent social learning framework. Analytical understanding of the underlying dynamics is important and challenging. In this work, we present a social learning framework with homogeneous learners (e.g., Policy Hill Climbing (PHC) learners), and model the behavior of players in the social learning framework as a hybrid dynamical system. By analyzing the dynamical system, we obtain some conditions about convergence or non-convergence. We experimentally verify the predictive power of our model using a number of representative games. Experimental results confirm the theoretical analysis. Under multiagent social learning framework, we modeled the behavior of agent in biologic environment, and theoretically analyzed the dynamics of the model. We present some sufficient conditions about convergence or non-convergence and prove them theoretically. It can be used to predict the convergence of the system.

  2. Space experiment "Rad Gene"-report 1; p53-Dependent gene expression in human cultured cells exposed to space environment

    Science.gov (United States)

    Takahashi, Akihisa; Ohnishi, Takeo; Suzuki, Hiromi; Omori, Katsunori; Seki, Masaya; Hashizume, Toko; Shimazu, Toru; Ishioka, Noriaki

    The space environment contains two major biologically significant influences: space radiations and microgravity. A p53 tumor suppressor protein plays a role as a guardian of the genome through the activity of p53-centered signal transduction pathways. The aim of this study was to clarify the biological effects of space radiations, microgravity and a space environment on the gene and protein expression of p53-dependent regulated genes. Space experiments were performed with two human cultured lymphoblastoid cell lines: one cells line (TSCE5) bears a wild-type p53 gene status, and another cells line (WTK1) bears a mutated p53 gene status. Un-der one gravity or microgravity condition, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station (ISS) for 8 days without experiencing the stress during launching and landing because the cells were frozen during these periods. Ground control samples also were cultured for 8 days in the CBEF on the ground during the same periods as space flight. Gene and protein expression was analyzed by using DNA chip (a 44k whole human genome microarray, Agilent Technologies Inc.) and protein chip (PanoramaTM Ab MicroArray, Sigma-Aldrich Co.), respectively. In addition, we analyzed the gene expression in cultured cells after space flight during 133 days with frozen condition. We report the results and discussion from the viewpoint of the functions of the up-regulated and down-regulated genes after an exposure to space radiations and/or microgravity. The initial goal of this space experiment was completely achieved. It is expected that data from this type of work will be helpful in designing physical protection from the deleterious effects of space radiations during long term stays in space.

  3. Effect of Chronic Exposure to Acidic Environment on Radiosensitivity of Gliosarcoma Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sora; Kim, Eunhee [Seoul National Univ., Seoul (Korea, Republic of)

    2014-05-15

    In this study, the chronic exposure of cells to acid culture medium, prior or posterior to irradiation, has been investigated for its effect on clonogenic cell survival. Unconventional high-dose radiation therapy, such as SRS, SBRT and MRT, may cause severe vascular damage in tumors, thereby a number of tumor cells facing chronic hypoxia and thus acidosis. According to our observation, gliosarcoma cells become more vulnerable to radiation damage by chronic exposure to acidic condition before irradiation. The longer the preirradiation exposure is, the more vulnerable to radiation damage the cells become. However, the repair of PLD by post-irradiation exposure to acid medium is efficient enough to eliminate the difference in number of the cells carrying PLDs due to different durations of preirradiation exposure to acidic condition.

  4. Influence of nanostructural environment and fluid flow on osteoblast-like cell behavior: a model for cell-mechanics studies.

    Science.gov (United States)

    Prodanov, L; Semeins, C M; van Loon, J J W A; te Riet, J; Jansen, J A; Klein-Nulend, J; Walboomers, X F

    2013-05-01

    Introducing nanoroughness on various biomaterials has been shown to profoundly effect cell-material interactions. Similarly, physical forces act on a diverse array of cells and tissues. Particularly in bone, the tissue experiences compressive or tensile forces resulting in fluid shear stress. The current study aimed to develop an experimental setup for bone cell behavior, combining a nanometrically grooved substrate (200 nm wide, 50 nm deep) mimicking the collagen fibrils of the extracellular matrix, with mechanical stimulation by pulsatile fluid flow (PFF). MC3T3-E1 osteoblast-like cells were assessed for morphology, expression of genes involved in cell attachment and osteoblastogenesis and nitric oxide (NO) release. The results showed that both nanotexture and PFF did affect cellular morphology. Cells aligned on nanotexture substrate in a direction parallel to the groove orientation. PFF at a magnitude of 0.7 Pa was sufficient to induce alignment of cells on a smooth surface in a direction perpendicular to the applied flow. When environmental cues texture and flow were interacting, PFF of 1.4 Pa applied parallel to the nanogrooves initiated significant cellular realignment. PFF increased NO synthesis 15-fold in cells attached to both smooth and nanotextured substrates. Increased collagen and alkaline phosphatase mRNA expression was observed on the nanotextured substrate, but not on the smooth substrate. Furthermore, vinculin and bone sialoprotein were up-regulated after 1 h of PFF stimulation. In conclusion, the data show that interstitial fluid forces and structural cues mimicking extracellular matrix contribute to the final bone cell morphology and behavior, which might have potential application in tissue engineering. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Towards an understanding of hot carrier cooling mechanisms in multiple quantum wells

    Science.gov (United States)

    Conibeer, Gavin; Zhang, Yi; Bremner, Stephen P.; Shrestha, Santosh

    2017-09-01

    Multiple quantum wells have been shown significantly reduced hot carrier cooling rates compared to bulk material and are thus a promising candidate for hot carrier solar cell absorbers. However, the mechanism(s) by which hot carrier cooling is restricted is not clear. A systematic study of carrier cooling rates in GaAs/AlAs multiple quantum wells (MQWs) with either varying barrier thickness or varying well thickness is presented in this paper. These allow an investigation as to whether the mechanisms of either a modification in hot carrier diffusion or a localisation of phonons emitted by hot carriers are primarily responsible for reduced carrier cooling rates. With the conclusion that for the structures investigated the situation is rather more complex with both carrier mobility to modify hot carrier diffusion, different diffusion rates for electrons and holes and reflection and localisation of phonons to enhance phonon bottleneck all playing their parts in modulating phonon reabsorption and hot carrier behaviour.

  6. Modular SiGe 130 nm Cell Library for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA space missions utilizing application-specific integrated circuits (ASICs) under extreme conditions have a critical need for high performance analog cell...

  7. Hot semiworks Redox studies

    Energy Technology Data Exchange (ETDEWEB)

    Evans, T.F.; Tomlinson, R.E.

    1954-01-27

    The separations Hot Semiworks at the Hanford Atomic Products Operation was built in order to: (1) develop optimum conditions for the economic operation of the Redox and TBP plants, (2) procure engineering design data which would allow the specification of process equipment required for new processes such as Purex, (3) provide facilities for the study of future process and engineering problems on a semiworks scale employing radioactive process solutions, and (4) provide facilities for immediate trouble shooting for urgent separations plant problems. The initial operation of this facility was designed to develop conditions for the economic operation of the Redox Plant. These studies, covering a period from November, 1952 to October, 1953, are described in this report. The Redox process is used at Hanford for the separation of uranium and plutonium from fission products and from each other. The basis of the process is the preferential extraction of uranium and plutonium nitrates from an aqueous phase of high salting strength into an organic solvent (methyl isobutyl ketone) to effect the separation from fission products. This operation is conducted continuously in columns, packed with Raschig rings, through which the phases are passed counter-currently. Uranium and plutonium are separated by converting the plutonium to a lower valence state, in which form it is preferentially extracted back into an aqueous phase of high salting strength in a second column. Uranium is then returned to an aqueous phase of low salting strength in a third column. The products are further decontaminated in similar additional cycles. A detailed description of the process is given in the Redox Technical Manual.

  8. The decay of hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

  9. Do scientists trace hot topics?

    CERN Document Server

    Wei, Tian; Wu, Chensheng; Yan, XiaoYong; Fan, Ying; Di, Zengru; Wu, Jinshan

    2013-01-01

    Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects.

  10. 40 CFR 406.80 - Applicability; description of the hot cereal subcategory.

    Science.gov (United States)

    2010-07-01

    ... cereal subcategory. 406.80 Section 406.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Hot Cereal Subcategory § 406.80 Applicability; description of the hot cereal subcategory. The provisions of this subpart are...

  11. 40 CFR 420.70 - Applicability; description of the hot forming subcategory.

    Science.gov (United States)

    2010-07-01

    ... resulting from hot forming operations conducted in primary, section, flat, and pipe and tube mills. ... forming subcategory. 420.70 Section 420.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Hot Forming...

  12. Hot tub lung: an intriguing diffuse parenchymal lung disease ...

    African Journals Online (AJOL)

    Hot Tub Lung(HTL) is a perplexing pulmonary disease attributed to the Mycobacterium Avium-intracellulare Complex (MAC). MAC is a ubiquitous atypical mycobacterium present in moist environment, and is not considered pathogenic, without the predisposing conditions like immunosuppression. However, HTL is a unique ...

  13. Low-cost personal cooling in hot humid offices

    DEFF Research Database (Denmark)

    Gunnarsen, Lars Bo; Santos, A.

    This report presents a low cost solution to avoid heat stress in a hot and humid environment based on a solar powered drying of supply air. The air drying facilities and a validation of the benefits through comprehensive human exposure studies are described. The study represents an example of app...

  14. Low-cost personal cooling in hot humid offices

    DEFF Research Database (Denmark)

    Gunnarsen, Lars Bo; Santos, A.

    This report presents a low cost solution to avoid heat stress in a hot and humid environment based on a solar powered drying of supply air. The air drying facilities and a validation of the benefits through comprehensive human exposure studies are described. The study represents an example...

  15. Simultaneous characterization of pancreatic stellate cells and other pancreatic components within three-dimensional tissue environment during chronic pancreatitis

    Science.gov (United States)

    Hu, Wenyan; Fu, Ling

    2013-05-01

    Pancreatic stellate cells (PSCs) and other pancreatic components that play a critical role in exocrine pancreatic diseases are generally identified separately by conventional studies, which provide indirect links between these components. Here, nonlinear optical microscopy was evaluated for simultaneous characterization of these components within a three-dimensional (3-D) tissue environment, primarily based on multichannel detection of intrinsic optical emissions and cell morphology. Fresh rat pancreatic tissues harvested at 1 day, 7 days, and 28 days after induction of chronic pancreatitis were imaged, respectively. PSCs, inflammatory cells, blood vessels, and collagen fibers were identified simultaneously. The PSCs at day 1 of chronic pancreatitis showed significant enlargement compared with those in normal pancreas (ppancreatic components coincidently within 3-D pancreatic tissues. It is a prospect for intravital observation of dynamic events under natural physiological conditions, and might help uncover the key mechanisms of exocrine pancreatic diseases, leading to more effective treatments.

  16. Role of Iron in the Preservation of Phototrophic Cells: An Example from a Modern Thermophilic Community at Chocolate Pots Hot Springs in Yellowstone National Park, USA

    Science.gov (United States)

    Parenteau, M. N.; Cady, S. L.; Jahnke, L. L.; Pierson, B. K.

    2006-12-01

    Banded Iron Formations (BIFs) are widespread Precambrian sedimentary deposits, the least metamorphosed of which often contain hematite and magnetite among the major oxide mineral species. Hypotheses developed to explain the origin of BIFs differ with regard to the mechanisms by which Fe2+ would have been oxidized to mixed ferric (Fe3+) mineral assemblages. The classical scenario is that oxidation occurred biotically, albeit indirectly, as a result of the photosynthetic production of oxygen by cyanobacteria. It has also been suggested that Fe2+ oxidation could have occurred by abiotic photochemical oxidation or by direct oxidation via the metabolism of anoxygenic phototrophs and chemolithotrophs. Our prior investigation of a modern iron-depositing thermal spring using microelectrodes indicates that cyanobacterial microbial mats have a significant physiological impact on Fe2+ oxidation via photosynthetic oxygen production and CO2 fixation. Recent compound-specific stable carbon isotope analyses of lipid biomarkers by our group reveals that anoxygenic phototrophs (e.g., Chloroflexus) do not oxidize Fe2+, but that they grow photoheterotrophically utilizing the cyanobacterial photosynthate. Evidence for a microbial role in the deposition of BIFs has been sought in the occurrence of microfossils in these structures. Microfossils are typically found preserved in the chert layers of BIFs. Though it has been argued that iron does not preserve cells well, our conventional TEM examination of iron-mineralized cyanobacterial cells has led us to hypothesize that iron can preserve the cellular fidelity of at least one phototroph and generate carbonaceous microfossils via permineralization. We have also used high resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) to characterize the microfossils and iron oxides located within and on the outside of such cells. Our extensive set of investigations with regard to deciphering the role of

  17. Proinflammatory Cytokine Environments Can Drive Interleukin-17 Overexpression by γ/δ T Cells in Systemic Juvenile Idiopathic Arthritis.

    Science.gov (United States)

    Kessel, Christoph; Lippitz, Katrin; Weinhage, Toni; Hinze, Claas; Wittkowski, Helmut; Holzinger, Dirk; Fall, Ndate; Grom, Alexei A; Gruen, Niklas; Foell, Dirk

    2017-07-01

    Systemic-onset juvenile idiopathic arthritis (JIA) is speculated to follow a biphasic course, with an initial systemic disease phase driven by innate immune mechanisms and interleukin-1β (IL-1β) as a key cytokine and a second chronic arthritic phase that may be dominated by adaptive immunity and cytokines such as IL-17A. Although a recent mouse model points to a critical role of IL-17-expressing γ/δ T cells in disease pathology, in humans, both the prevalence of IL-17 and the role of IL-17-producing cells are still unclear. Serum samples from systemic JIA patients and healthy pediatric controls were analyzed for the levels of IL-17A and related cytokines. Whole blood samples were studied for cellular expression of IL-17 and interferon-γ (IFNγ). CD4+ and γ/δ T cells isolated from the patients and controls were assayed for cytokine secretion in different culture systems. IL-17A was prevalent in sera from patients with active systemic JIA, while both ex vivo and in vitro experiments revealed that γ/δ T cells overexpressed this cytokine. This was not seen with CD4+ T cells, which expressed strikingly low levels of IFNγ. Therapeutic IL-1 blockade was associated with partial normalization of both cytokine expression phenotypes. Furthermore, culturing healthy donor γ/δ T cells in serum from systemic JIA patients or in medium spiked with IL-1β, IL-18, and S100A12 induced IL-17 overexpression at levels similar to those observed in the patients' cells. A systemic JIA cytokine environment may prime γ/δ T cells in particular for IL-17A overexpression. Thus, our observations in systemic JIA patients strongly support a pathophysiologic role of these cells, as proposed by the recent murine model. © 2017, American College of Rheumatology.

  18. High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals.

    Science.gov (United States)

    Mao, Xiaoli; Zhou, Ru; Zhang, Shouwei; Ding, Liping; Wan, Lei; Qin, Shengxian; Chen, Zhesheng; Xu, Jinzhang; Miao, Shiding

    2016-01-13

    An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs.

  19. Influence of air contaminants on planar, self-breathing hydrogen PEM fuel cells in an outdoor environment

    Science.gov (United States)

    Biesdorf, Johannes; Zamel, Nada; Kurz, Timo

    2014-02-01

    In this study, the effects of air contaminants on the operation of air-breathing fuel cells in an outdoor environment are investigated. For this purpose, a unique testing platform, which allows continuous operation of 30 cells at different locations, was developed. Three of these testing platforms were placed at different sites in Freiburg im Breisgau, Germany, with high variances of weather and pollution patterns. These locations range from a highly polluted place next to a busy highway to a location with virtually pure air at an altitude of 1205 m. The fuel cells were tested at all sites for over 4500 h in continuous operation. The degradation of the cells due to air pollutants was measured as a voltage decrease for three different operation loads and membranes from two different manufactures. As the temperature of the fuel cells has not been regulated, the irreversible degradation of the cell voltages could not be isolated from the dominant influence of the temperature in the raw data. With the use of the measured data, the impact of real mixtures of air contaminants was observed to be mainly reversible.

  20. The Prevalence of STIV c92-Like Proteins in Acidic Thermal Environments

    Directory of Open Access Journals (Sweden)

    Jamie C. Snyder

    2011-01-01

    Full Text Available A new type of viral-induced lysis system has recently been discovered for two unrelated archaeal viruses, STIV and SIRV2. Prior to the lysis of the infected host cell, unique pyramid-like lysis structures are formed on the cell surface by the protrusion of the underlying cell membrane through the overlying external S-layer. It is through these pyramid structures that assembled virions are released during lysis. The STIV viral protein c92 is responsible for the formation of these lysis structures. We searched for c92-like proteins in viral sequences present in multiple viral and cellular metagenomic libraries from Yellowstone National Park acidic hot spring environments. Phylogenetic analysis of these proteins demonstrates that, although c92-like proteins are detected in these environments, some are quite divergent and may represent new viral families. We hypothesize that this new viral lysis system is common within diverse archaeal viral populations found within acidic hot springs.

  1. Kelley Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Longyear, A.B. (ed.)

    1980-06-01

    The proposed core activity in the Kelly Hot Spring Agricultural Center is a nominal 1200 sow swine raising complex. The swine raising is to be a totally confined operation for producing premium pork in controlled environment facilities that utilize geothermal energy. The complex will include a feedmill for producing the various feed formulae required for the animals from breeding through gestation, farrowing, nursery, growing and finishing. The market animals are shipped live by truck to slaughter in Modesto, California. A complete waste management facility will include manure collection from all raising areas, transport via a water flush sysem to methane (biogas) generators, manure separation, settling ponds and disposition of the surplus agricultural quality water. The design is based upon the best commercial practices in confined swine raising in the US today. The most unique feature of the facility is the utilization of geothermal hot water for space heating and process energy throughout the complex.

  2. Cell-Based Sensor System Using L6 Cells for Broad Band Continuous Pollutant Monitoring in Aquatic Environments

    Directory of Open Access Journals (Sweden)

    Evamaria Stütz

    2012-03-01

    Full Text Available Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism, oxygen consumption (respiration and impedance (morphology of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water was tested with monolayers of L6 cells (rat myoblasts. The cytotoxicity or cellular effects induced by inorganic ions (Ni2+ and Cu2+ can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity.

  3. Cell-based sensor system using L6 cells for broad band continuous pollutant monitoring in aquatic environments.

    Science.gov (United States)

    Kubisch, Rebekka; Bohrn, Ulrich; Fleischer, Maximilian; Stütz, Evamaria

    2012-01-01

    Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism), oxygen consumption (respiration) and impedance (morphology) of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water) was tested with monolayers of L6 cells (rat myoblasts). The cytotoxicity or cellular effects induced by inorganic ions (Ni(2+) and Cu(2+)) can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity.

  4. Click-crosslinkable and photodegradable gelatin hydrogels for cytocompatible optical cell manipulation in natural environment

    Science.gov (United States)

    Tamura, Masato; Yanagawa, Fumiki; Sugiura, Shinji; Takagi, Toshiyuki; Sumaru, Kimio; Kanamori, Toshiyuki

    2015-01-01

    This paper describes the generation of “click-crosslinkable“ and “photodegaradable“ gelatin hydrogels from the reaction between dibenzocycloctyl-terminated photoclevable tetra-arm polyethylene glycol and azide-modified gelatin. The hydrogels were formed in 30 min through the click-crosslinking reaction. The micropatterned features in the hydrogels were created by micropatterned light irradiation; the minimum resolution of micropatterning was 10-μm widths for line patterns and 20-μm diameters for circle patterns. Cells were successfully encapsulated in the hydrogels without any loss of viability across a wide concentration range of crosslinker. In contrast, an activated-ester-type photocleavable crosslinker, which we previously used to prepare photodegradable gelatin hydrogels, induced a decrease in cell viability at crosslinker concentrations greater than 1.8 mM. We also observed morphology alteration and better growth of cancer cells in the click-crosslinked photodegradable gelatin hydrogels that included matrigel than in the absence of matrigel. We also demonstrated micropatterning of the hydrogels encapsulating cells and optical cell separation. Both of the cells that remained in the non-irradiated area and the cells collected from the irradiated area maintained their viability. PMID:26450015

  5. Activation, homing, and role of the mesenchymal stem cells in the inflammatory environment

    Directory of Open Access Journals (Sweden)

    Zachar L

    2016-12-01

    Full Text Available Lukáš Zachar, Darina Bačenková, Ján Rosocha Associated Tissue Bank of Faculty of Medicine of P. J. Šafárik University and University Hospital of L. Pasteur, Košice, Slovak Republic Abstract: Human mesenchymal stem cells (MSCs are considered to be a promising source of cells in regenerative medicine. They have large potential to differentiate into various tissue-specific populations and may be isolated from diverse tissues in desired quantities. As cells of potential autologous origin, they allow recipients to avoid the alloantigen responses. They also have the ability to create immunomodulatory microenvironment, and thus help to minimize organ damage caused by the inflammation and cells activated by the immune system. Our knowledge about the reparative, regenerative, and immunomodulatory properties of MSCs is advancing. At present, there is a very comprehensible idea on how MSCs affect the immune system, particularly in relation to the tissue and organ damage on immunological basis. Hitherto a number of effective mechanisms have been described by which MSCs influence the immune responses. These mechanisms include a secretion of soluble bioactive agents, an induction of regulatory T cells, modulation of tolerogenic dendritic cells, as well as induction of anergy and apoptosis. MSCs are thus able to influence both innate and adaptive immune responses. Soluble factors that are released into local microenvironment with their subsequent paracrine effects are keys to the activation. As a result, activated MSCs contribute to the restoration of damaged tissues or organs through various mechanisms facilitating reparative and regenerative processes as well as through immunomodulation itself and differentiation into the cells of the target tissue. Keywords: stem cells, migration, bioactive factors, immunomodulatory microenvironment, regulatory T cells, tissue regeneration 

  6. Neptune's Wandering Hot Pole

    Science.gov (United States)

    Orton, Glenn; Fletcher, Leigh; Yanamandra-Fisher, Padma; Geballe, Tom; Hammel, Heidi; Fujiyoshi, Takuya; Encrenaz, Therese; Hofstadter, Mark; Mousis, Olivier; Fuse, Tetsuharu

    2010-05-01

    Images of stratospheric emission from Neptune obtained in 2006 at ESO's Very Large Telescope (Orton et al., 2007, A&A 473, L5) revealed a near-polar hot spot near 70 deg. S latitude that was detectable in different filters sampling both methane (~7-micron) and ethane (~12-micron) emission from Neptune's stratosphere. Such a feature was not present in 2003 Keck and 2005 Gemini North observations: these showed only a general warming trend towards Neptune's pole that was longitudinally homogeneous. Because of the paucity of longitudinal sampling in the 2003, 2005 and 2006 images, it was not clear whether the failure to see this phenomenon in 2003 and 2005 was simply the result of insufficient longitudinal sampling or whether the phenomenon was truly variable in time. To unravel these two possibilities, we proposed for time on large telescopes that were capable of resolving Neptune at these wavelengths. We were granted time at Gemini South in 2007 using T-Recs, Subaru time in 2008 using the COMICS instrument and VLT time in 2008 and 2009 using VISIR. Two serendipitous T-Recs images of Neptune were also obtained in 2007 using a broad-band N (8-14 micron) filter, whose radiance is dominated by 12-micron ethane emission, and whose primary purpose was navigation of N-band spectroscopy. The feature was re-observed (i) in 2007 in the T-Recs N-band filter and (ii) in 2008 with COMICS in a 12.5-micron image. Unfortunately, none of the telescope time granted was sufficient to sample all longitudes over the 12-hour period of this latitude, and so no definitive separation of the two possibilities was obtained. However, considering the ensemble of images as a random sample of longitudes, it is likely that the phenomenon is ephemeral in time, as it was observed only twice among 9 independent observing epochs. We will continue to request observations to sample all longitudes systematically, but our current sample argues that the phenomenon is truly ephemera, because we most likely

  7. Phase boundary of hot dense fluid hydrogen.

    Science.gov (United States)

    Ohta, Kenji; Ichimaru, Kota; Einaga, Mari; Kawaguchi, Sho; Shimizu, Katsuya; Matsuoka, Takahiro; Hirao, Naohisa; Ohishi, Yasuo

    2015-11-09

    We investigated the phase transformation of hot dense fluid hydrogen using static high-pressure laser-heating experiments in a laser-heated diamond anvil cell. The results show anomalies in the heating efficiency that are likely to be attributed to the phase transition from a diatomic to monoatomic fluid hydrogen (plasma phase transition) in the pressure range between 82 and 106 GPa. This study imposes tighter constraints on the location of the hydrogen plasma phase transition boundary and suggests higher critical point than that predicted by the theoretical calculations.

  8. Research study on high energy radiation effect and environment solar cell degradation methods

    Science.gov (United States)

    Horne, W. E.; Wilkinson, M. C.

    1974-01-01

    The most detailed and comprehensively verified analytical model was used to evaluate the effects of simplifying assumptions on the accuracy of predictions made by the external damage coefficient method. It was found that the most serious discrepancies were present in heavily damaged cells, particularly proton damaged cells, in which a gradient in damage across the cell existed. In general, it was found that the current damage coefficient method tends to underestimate damage at high fluences. An exception to this rule was thick cover-slipped cells experiencing heavy degradation due to omnidirectional electrons. In such cases, the damage coefficient method overestimates the damage. Comparisons of degradation predictions made by the two methods and measured flight data confirmed the above findings.

  9. 29 CFR 1915.14 - Hot work.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment § 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed in...

  10. Symbiosis in cell evolution: Life and its environment on the early earth

    Science.gov (United States)

    Margulis, L.

    1981-01-01

    The book treats cell evolution from the viewpoint of the serial endosymbiosis theory of the origin of organelles. Following a brief outline of the symbiotic theory, which holds that eukaryotes evolved by the association of free-living bacteria with a host prokaryote, the diversity of life is considered, and five kingdoms of organisms are distinguished: the prokaryotic Monera and the eukaryotic Protoctista, Animalia, Fungi and Plantae. Symbiotic and traditional direct filiation theories of cell evolution are compared. Recent observations of cell structure and biochemistry are reviewed in relation to early cell evolution, with attention given to the geological context for the origin of eukaryotic cells, the origin of major bacterial anaerobic pathways, the relationship between aerobic metabolism and atmospheric oxygen, criteria for distinguishing symbiotic organelles from those that originated by differentiation, and the major classes of eukaryotic organelles: mitochondria, cilia, microtubules, the mitotic and meiotic apparatuses, and pastids. Cell evolution during the Phanerozoic is also discussed with emphasis on the effects of life on the biosphere

  11. Controlling micro- and nano-environment of tumor and stem cells for novel research and therapy of brain cancer

    Science.gov (United States)

    Smith, Christopher Lloyd

    The use of modern technologies in cancer research has engendered a great deal of excitement. Many of these advanced approaches involve in-depth mathematical analyses of the inner working of cells, via genomic and proteomic analyses. However these techniques may not be ideal for the study of complex cell phenotypes and behaviors. This dissertation explores cancer and potential therapies through phenotypic analysis of cell behaviors, an alternative approach. We employ this experimental framework to study brain cancer (glioma), a particularly formidable example of this diverse ailment. Through the application of micro- and nanotechnology, we carefully control the surrounding environments of cells to understand their responses to various cues and to manipulate their behaviors. Subsequently we obtain clinically relevant information that allows better understanding of glioma, and enhancement of potential therapies. We first aim to address brain tumor dispersal, through analysis of cell migration. Utilizing nanometer-scale topographic models of the extracellular matrix, we study the migratory response of glioma cells to various stimuli in vitro. Second, we implement knowledge gained from these investigations to define characteristics of tumor progression in patients, and to develop treatments inhibiting cell migration. Next we use microfluidic and nanotopographic models to study the behaviors of stem cells in vitro. Here we attempt to improve their abilities to deliver therapeutic proteins to cancer, an innovative treatment approach. We analyze the multi-step process by which adipose-derived stem cells naturally home to tumor sites, and identify numerous environmental perturbations to enhance this behavior. Finally, we attempt to demonstrate that these cell culture-based manipulations can enhance the localization of adipose stem cells to glioma in vivo using animal models. Throughout this work we utilize environmental cues to analyze and induce particular behaviors in

  12. Permeabilidade a quente de refratários para revestimento de cubas eletrolíticas Hot permeability of refractories for aluminum electrolytic cells lining at high temperatures

    Directory of Open Access Journals (Sweden)

    D. Y. Miyaji

    2007-03-01

    Full Text Available Na indústria do alumínio primário, um dos principais responsáveis pela deterioração do revestimento refratário nas cubas de redução eletrolítica é o ataque por banho criolítico com alta concentração de NaF, que penetra e reage com o refratário podendo, em condições extremas, causar a parada prematura de operação da cuba e grandes prejuízos econômicos. Baseando-se nos mais recentes estudos de caracterização de refratários para cubas, uma boa correlação tem sido encontrada entre a resistência à corrosão e a permeabilidade, a qual é calculada pela equação de Forchheimer para a obtenção das constantes k1 Darciana (efeito viscoso e k2 não Darciana (efeito inercial. Entretanto, na maioria das situações, as medidas da permeabilidade têm sido efetuadas à temperatura ambiente, embora o refratário em uso esteja a superior temperatura. Este trabalho visa avaliar como esta permeabilidade se altera em temperaturas de até 700 ºC buscando, assim, uma melhor correlação dos resultados com as condições reais de operação. Pretende-se também, investigar essa propriedade em refratários empregados no revestimento de cadinhos para o transporte de alumínio líquido, com o intuito de verificar a aplicabilidade da permeametria como uma ferramenta de caracterização desses materiais cujo interesse de aplicação e desenvolvimento tem sido cada vez maior.In the aluminium primary industry, one of the main causes for electrolytic cells lining deterioration is the chemical attack by high NaF content cryolitic bath, that penetrates and reacts with the refractory, shortening the cell’s service life and resulting great economic losses. Based on the most recent studies on characterization of alumino-silicate refractories for aluminum cell linings, a good correlation has been found between its chemical attack by molten fluorides and the permeability, which is calculated by Forchheimer’s equation in order to obtain the Darcian

  13. Environment Dictates Dependence on Mitochondrial Complex I for NAD+ and Aspartate Production and Determines Cancer Cell Sensitivity to Metformin.

    Science.gov (United States)

    Gui, Dan Y; Sullivan, Lucas B; Luengo, Alba; Hosios, Aaron M; Bush, Lauren N; Gitego, Nadege; Davidson, Shawn M; Freinkman, Elizaveta; Thomas, Craig J; Vander Heiden, Matthew G

    2016-11-08

    Metformin use is associated with reduced cancer mortality, but how metformin impacts cancer outcomes is controversial. Although metformin can act on cells autonomously to inhibit tumor growth, the doses of metformin that inhibit proliferation in tissue culture are much higher than what has been described in vivo. Here, we show that the environment drastically alters sensitivity to metformin and other complex I inhibitors. We find that complex I supports proliferation by regenerating nicotinamide adenine dinucleotide (NAD)+, and metformin's anti-proliferative effect is due to loss of NAD+/NADH homeostasis and inhibition of aspartate biosynthesis. However, complex I is only one of many inputs that determines the cellular NAD+/NADH ratio, and dependency on complex I is dictated by the activity of other pathways that affect NAD+ regeneration and aspartate levels. This suggests that cancer drug sensitivity and resistance are not intrinsic properties of cancer cells, and demonstrates that the environment can dictate sensitivity to therapies that impact cell metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Effects of Coix seed oil on human retinal capillary endothelial cells proliferation and VEGF expression in high glucose environment

    Directory of Open Access Journals (Sweden)

    Min Li

    2014-12-01

    Full Text Available AIM: To study the effects of different concentrations of Coix seed oil on human retinal capillary endothelial cells(HRCECsproliferation and vascular endothelial growth factor(VEGFexpression in high glucose environment.METHODS: HRCECs extracted from human fresher eyeball and cultured in vitro, and ultimately used in the experiment were the growth of 3rd~4th cells, the experimental were divided into blank control group, low glucose control group, high glucose control group, high glucose +(50μL/mL, 100μL/mL, 200μL/mLdifferent concentrations Coix seed oil group. Detecting the multiplication of HRCECs by MTT, the immunocytochemical method was employed to detect the each group HRCECs of VEGF expression.RESULTS:MTT assay results showed that: different concentrations of coix seed oil acted at HRCECs for 48h, inhibition of cell proliferation was significant difference compared with high glucose control group(PP>0.05. Immunocytochemical assay showed that: 50μL/mL, 100μL/mL, 200μL/mL Coix seed oil acted at HRCECs 48h, the expression of VEGF decreased significantly compared with the high glucose control group(PPCONCLUSION:Coix seed oil can inhibit the HRCECs proliferation and suppress the VEGF expression in high glucose environment.

  15. Bone marrow-derived cells and tumor growth : Contribution of bone marrow-derived cells to tumor micro-environments with special focus on mesenchymal stem cells

    NARCIS (Netherlands)

    Roorda, Berber D.; ter Elst, Arja; Kamps, Willem A.; de Bont, Eveline S. J. M.

    Research has provided evidence that tumor growth depends on the interaction of tumor cells with stromal cells, as already suggested in 1889 by Paget. Experimental and clinical studies have revealed that tumor stromal cells can be derived from bone marrow (BM)-derived progenitor cells, such as

  16. How molecular motors work in the crowded environment of living cells: coexistence and efficiency of normal and anomalous transport.

    Directory of Open Access Journals (Sweden)

    Igor Goychuk

    Full Text Available Recent experiments reveal both passive subdiffusion of various nanoparticles and anomalous active transport of such particles by molecular motors in the molecularly crowded environment of living biological cells. Passive and active microrheology reveals that the origin of this anomalous dynamics is due to the viscoelasticity of the intracellular fluid. How do molecular motors perform in such a highly viscous, dissipative environment? Can we explain the observed co-existence of the anomalous transport of relatively large particles of 100 to 500 nm in size by kinesin motors with the normal transport of smaller particles by the same molecular motors? What is the efficiency of molecular motors in the anomalous transport regime? Here we answer these seemingly conflicting questions and consistently explain experimental findings in a generalization of the well-known continuous diffusion model for molecular motors with two conformational states in which viscoelastic effects are included.

  17. The effects of Hot Pepper Extract and Capsaicin on Adipocyte Metabolism

    Directory of Open Access Journals (Sweden)

    Ching Sheng, Chu

    2008-03-01

    Full Text Available Objectives : The purpose of this study is to investigate the effects of hot pepper extract and capsaicin on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3 days in the absence or presence of hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖. The effects of hot pepper extract and capsaicin on adipogenesis were examined by measuring GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖ for 3 hrs. The effects of hot pepper extract and capsaicin on lipolysis were examined by measuring free glycerol released. Fat tissue from pig skin was injected with hot pepper extract or capsaicinCFP ranging from 0.1 to 10㎎/㎖ to examine the effects of hot pepper extract and capsaicin on histological changes under light microscopy. Results : The following results were obtained from present study on adipogenesis of preadipocytes, lipolysis of adipocytes and histological changes in fat tissue. 1. Hot pepper extract and capsaicin inhibited adipogenic differentiation at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenesis than hot pepper extract. 2. Hot pepper extract and capsaicin decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenic differentiation than hot pepper extract. 3. Hot pepper extract and capsaicin increased glycerol release at the concentration of 0.1㎎/㎖. There was no difference in lipolytic activity between hot pepper extract and

  18. Study of scale formation on AISI 316L in simulated solid oxide fuel cell bi-polar environments

    Energy Technology Data Exchange (ETDEWEB)

    Ziomek-Moroz, M.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Bullard, Sophie J.; Singh (PNNL), P.; Windisch, C.F., Jr. (PNNL)

    2004-01-01

    Significant progress made towards reducing the operating temperature of solid oxide fuel cells (SOFC) from {approx}1000 C to {approx}600 C is expected to permit the use of metallic materials with substantial cost reduction. One of the components in a SOFC stack to be made of metallic materials is a bipolar separator, also called an interconnect. It provides electrical connection between individual cells and serves as a gas separator to prevent mixing of the fuel and air. At operating temperature, the material selected for interconnects should possess good chemical and mechanical stability in complex fuel and oxidant gaseous environments, good electrical conductivity, and a coefficient of thermal expansion (CTE) that matches that of the cathode, anode, and electrolyte components. Cr2O3 scale-forming alloys appear to be the most promising candidates. There appears to be a mechanism whereby the environment on the fuel side of a stainless steel interconnect changes the corrosion behavior of the metal on the air side. The corrosion behavior of 316L stainless steel simultaneously exposed to air on one side and H2+3%H2O on the other at 907 K was studied using X-ray diffraction (XRD) and Raman spectroscopy. The electrical property of the investigated material was determined in terms of area-specific resistance (ASR). The chemical and electrical properties of 316L exposed to a dual environment of air/ (H2+H2O) were compared to those of 316L exposed to a single environment of air/air.

  19. Metastatic Growth from Dormant Cells Induced by a Col-I Enriched Fibrotic Environment

    Science.gov (United States)

    Barkan, Dalit; El Touny, Lara H.; Michalowski, Aleksandra M.; Smith, Jane Ann; Chu, Isabel; Davis, Anne Sally; Webster, Joshua D.; Hoover, Shelley; Simpson, R. Mark; Gauldie, Jack; Green, Jeffrey E.

    2010-01-01

    Breast cancer that recurs as metastatic disease many years after primary tumor resection and adjuvant therapy appears to arise from tumor cells that disseminated early in the course of disease but did not develop into clinically apparent lesions. These long-term surviving, disseminated tumor cells maintain a state of dormancy, but may be triggered to proliferate through largely unknown factors. We now demonstrate that the induction of fibrosis, associated with deposition of type I collagen (Col-I) in the in vivo metastatic microenvironment, induces dormant D2.0R cells to form proliferative metastatic lesions through β1-integrin signaling. In vitro studies using a 3D culture system modeling dormancy demonstrated that Col-I induces quiescent D2.0R cells to proliferate through β1-integrin activation of SRC and FAK, leading to ERK-dependent myosin light chain (MLC) phosphorylation by myosin light chain kinase (MLCK) and actin stress fiber formation. Blocking β1-integrin, Src, ERK or MLCK by shRNA or pharmacologic approaches inhibited Col-I-induced activation of this signaling cascade, cytoskeletal reorganization and proliferation. These findings demonstrate that fibrosis with type I collagen enrichment at the metastatic site may be a critical determinant of cytoskeletal reorganization in dormant tumor cells leading to their transition from dormancy to metastatic growth. Thus, inhibiting Col-I production, its interaction with β1-integrin and downstream signaling of β1-integrin may be important strategies for preventing or treating recurrent metastatic disease. PMID:20570886

  20. Hot Jupiter Magnetospheres

    Science.gov (United States)

    Trammell, George B.; Arras, Phil; Li, Zhi-Yun

    2011-02-01

    The upper atmospheres of close-in gas giant exoplanets ("hot Jupiters") are subjected to intense heating and tidal forces from their parent stars. The atomic (H) and ionized (H+) hydrogen layers are sufficiently rarefied that magnetic pressure may dominate gas pressure for expected planetary magnetic field strength. We examine the structure of the magnetosphere using a 3D isothermal magnetohydrodynamic model that includes a static "dead zone" near the magnetic equator containing gas confined by the magnetic field, a "wind zone" outside the magnetic equator in which thermal pressure gradients and the magneto-centrifugal-tidal effect give rise to a transonic outflow, and a region near the poles where sufficiently strong tidal forces may suppress transonic outflow. Using dipole field geometry, we estimate the size of the dead zone to be several to tens of planetary radii for a range of parameters. Tides decrease the size of the dead zone, while allowing the gas density to increase outward where the effective gravity is outward. In the wind zone, the rapid decrease of density beyond the sonic point leads to smaller densities relative to the neighboring dead zone, which is in hydrostatic equilibrium. To understand the appropriate base conditions for the 3D isothermal model, we compute a simple 1D thermal model in which photoelectric heating from the stellar Lyman continuum is balanced by collisionally excited Lyα cooling. This 1D model exhibits a H layer with temperature T ~= 5000-10,000 K down to a pressure P ~ 10-100 nbar. Using the 3D isothermal model, we compute maps of the H column density as well as the Lyα transmission spectra for parameters appropriate for HD 209458b. Line-integrated transit depths sime5%-10% can be achieved for the above base conditions, in agreement with the results of Koskinen et al. A deep, warm H layer results in a higher mass-loss rate relative to that for a more shallow layer, roughly in proportion to the base pressure. Strong magnetic

  1. Service life estimation of liquid silicone rubber seals in polymer electrolyte membrane fuel cell environment

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Tong; Van Zee, J.W. [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Lin, C.-W. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University (China); Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Chien, C.H. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University (China); Chao, Y.J. [Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2011-02-01

    Polymer electrolyte membrane fuel cell (PEMFC) is a promising power source for many applications such as automobiles. Sealing around the perimeter of the cell is required to prevent the gases/liquids inside the cell from leaking and polymers are usually used for the seal or gasket materials. They in general possess the viscoelastic property which induces stress relaxation of the material under constant strain. The stress relaxation behavior of liquid silicone rubber, a type of polymer used as seals in PEMFCs, is studied in this work. A Prony series is used to predict the compression stress relaxation curve at different strain levels. Applying the time-temperature superposition, master curves are generated and used for predicting the service life of this material as seals in PEMFCs. The estimated lives in water and in air are compared. (author)

  2. Service life estimation of liquid silicone rubber seals in polymer electrolyte membrane fuel cell environment

    Science.gov (United States)

    Cui, Tong; Lin, C.-W.; Chien, C. H.; Chao, Y. J.; Van Zee, J. W.

    Polymer electrolyte membrane fuel cell (PEMFC) is a promising power source for many applications such as automobiles. Sealing around the perimeter of the cell is required to prevent the gases/liquids inside the cell from leaking and polymers are usually used for the seal or gasket materials. They in general possess the viscoelastic property which induces stress relaxation of the material under constant strain. The stress relaxation behavior of liquid silicone rubber, a type of polymer used as seals in PEMFCs, is studied in this work. A Prony series is used to predict the compression stress relaxation curve at different strain levels. Applying the time-temperature superposition, master curves are generated and used for predicting the service life of this material as seals in PEMFCs. The estimated lives in water and in air are compared.

  3. Per-energy capacity and handoff strategies in macro-femto cells environment

    KAUST Repository

    Leon, Jaime

    2012-04-01

    The effect of smaller cells being placed in a heterogenous network can improve the way energy is spent in a system. Handoff strategies, bandwidth allocation and path loss calculations in different scenarios show how this is possible as the size of the cell is decreased. As a result, users can experience the same or better capacities while maximising the capacity per unit energy spent. The per-energy capacity metric is introduced as a suitable handoff strategy that considers the energy spent as an important criterion. © 2012 IEEE.

  4. Water outlet control mechanism for fuel cell system operation in variable gravity environments

    Science.gov (United States)

    Vasquez, Arturo (Inventor); McCurdy, Kerri L. (Inventor); Bradley, Karla F. (Inventor)

    2007-01-01

    A self-regulated water separator provides centrifugal separation of fuel cell product water from oxidant gas. The system uses the flow energy of the fuel cell's two-phase water and oxidant flow stream and a regulated ejector or other reactant circulation pump providing the two-phase fluid flow. The system further uses a means of controlling the water outlet flow rate away from the water separator that uses both the ejector's or reactant pump's supply pressure and a compressibility sensor to provide overall control of separated water flow either back to the separator or away from the separator.

  5. Construction of an external electrode for determination of electrochemical corrosion potential in normal operational conditions of an BWR type reactor for hot cells; Construccion de un electrodo externo para determinacion del potencial de corrosion electroquimico en condiciones normales de operacion de un reactor tipo BWR para celdas calientes

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar T, J.A.; Rivera M, H.; Hernandez C, R. [Departamento de Sintesis y Caracterizacion de Materiales, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    The behavior of the corrosion processes at high temperature requires of external devices that being capable to resist a temperature of 288 Centigrade and a pressure of 80 Kg/cm{sup 2}, to give stable and reproducible results of some variable and resisting physically and chemically the radiation. The external electrode of Ag/AgCl fulfils all the requirements in the determination of the electrochemical corrosion potential under normal operational conditions of a BWR type reactor in hot cells. (Author)

  6. Nickel Hydrogen Cell Positive-Electrode Studies: Cobalt Segregation in Reducing Environments,

    Science.gov (United States)

    1987-05-22

    Encyclopedia of Chemical Electrode Potentials, Plenum Press, New York, 1982. 8. M. Pourbaix, Atlas of Electrochemical Equilibria in Aqueous Solutions...such conditions, it is possible that chemical or electrochemical reactions that are normally thought not to occur in battery cells can occur with...diffraction, ESCA (electron spectroscopy for chemical analysis), SEM (scanning electron microscopy), and EVS ( electrochemical - -voltage spectroscopy). S6

  7. Synchronization ability of coupled cell-cycle oscillators in changing environments

    Science.gov (United States)

    2012-01-01

    Background The biochemical oscillator that controls periodic events during the Xenopus embryonic cell cycle is centered on the activity of CDKs, and the cell cycle is driven by a protein circuit that is centered on the cyclin-dependent protein kinase CDK1 and the anaphase-promoting complex (APC). Many studies have been conducted to confirm that the interactions in the cell cycle can produce oscillations and predict behaviors such as synchronization, but much less is known about how the various elaborations and collective behavior of the basic oscillators can affect the robustness of the system. Therefore, in this study, we investigate and model a multi-cell system of the Xenopus embryonic cell cycle oscillators that are coupled through a common complex protein, and then analyze their synchronization ability under four different external stimuli, including a constant input signal, a square-wave periodic signal, a sinusoidal signal and a noise signal. Results Through bifurcation analysis and numerical simulations, we obtain synchronization intervals of the sensitive parameters in the individual oscillator and the coupling parameters in the coupled oscillators. Then, we analyze the effects of these parameters on the synchronization period and amplitude, and find interesting phenomena, e.g., there are two synchronization intervals with activation coefficient in the Hill function of the activated CDK1 that activates the Plk1, and different synchronization intervals have distinct influences on the synchronization period and amplitude. To quantify the speediness and robustness of the synchronization, we use two quantities, the synchronization time and the robustness index, to evaluate the synchronization ability. More interestingly, we find that the coupled system has an optimal signal strength that maximizes the synchronization index under different external stimuli. Simulation results also show that the ability and robustness of the synchronization for the square

  8. Rheum emodin inhibits enterovirus 71 viral replication and affects the host cell cycle environment.

    Science.gov (United States)

    Zhong, Ting; Zhang, Li-Ying; Wang, Zeng-Yan; Wang, Yue; Song, Feng-Mei; Zhang, Ya-Hong; Yu, Jing-Hua

    2017-03-01

    Human enterovirus 71 (EV71) is the primary causative agent of recent large-scale outbreaks of hand, foot, and mouth disease (HFMD) in Asia. Currently, there are no drugs available for the prevention and treatment of HFMD. In this study, we compared the anti-EV71 activities of three natural compounds, rheum emodin, artemisinin and astragaloside extracted from Chinese herbs Chinese rhubarb, Artemisia carvifolia and Astragalus, respectively, which have been traditionally used for the treatment and prevention of epidemic diseases. Human lung fibroblast cell line MRC5 was mock-infected or infected with EV71, and treated with drugs. The cytotoxicity of the drugs was detected with MTT assay. The cytopathic effects such as cell death and condensed nuclei were morphologically observed. The VP1-coding sequence required for EV71 genome replication was assayed with qRT-PCR. Viral protein expression was analyzed with Western blotting. Viral TCID50 was determined to evaluate EV71 virulence. Flow cytometry analysis of propidium iodide staining was performed to analyze the cell cycle distribution of MRC5 cells. Rheum emodin (29.6 μmol/L) effectively protected MRC5 cells from EV71-induced cytopathic effects, which resulted from the inhibiting viral replication: rheum emodin treatment decreased viral genomic levels by 5.34-fold, viral protein expression by less than 30-fold and EV71 virulence by 0.33107-fold. The fact that inhibition of rheum emodin on viral virulence was much stronger than its effects on genomic levels and viral protein expression suggested that rheum emodin inhibited viral maturation. Furthermore, rheum emodin treatment markedly diminished cell cycle arrest at S phase in MRC5 cells, which was induced by EV71 infection and favored the viral replication. In contrast, neither astragaloside (50 μmol/L) nor artemisinin (50 μmol/L) showed similar anti-EV71 activities. Among the three natural compounds tested, rheum emodin effectively suppressed EV71 viral replication

  9. Stimulating Fracture Healing in Ischemic Environments: Does Oxygen Direct Stem Cell Fate during Fracture Healing?

    Science.gov (United States)

    Miclau, Katherine R.; Brazina, Sloane A.; Bahney, Chelsea S.; Hankenson, Kurt D.; Hunt, Thomas K.; Marcucio, Ralph S.; Miclau, Theodore

    2017-01-01

    Bone fractures represent an enormous societal and economic burden as one of the most prevalent causes of disability worldwide. Each year, nearly 15 million people are affected by fractures in the United States alone. Data indicate that the blood supply is critical for fracture healing; as data indicate that concomitant bone and vascular injury are major risk factors for non-union. However, the various role(s) that the vasculature plays remains speculative. Fracture stabilization dictates stem cell fate choices during repair. In stabilized fractures stem cells differentiate directly into osteoblasts and heal the injury by intramembranous ossification. In contrast, in non-stable fractures stem cells differentiate into chondrocytes and the bone heals through endochondral ossification, where a cartilage template transforms into bone as the chondrocytes transform into osteoblasts. One suggested role of the vasculature has been to participate in the stem cell fate decisions due to delivery of oxygen. In stable fractures, the blood vessels are thought to remain intact and promote osteogenesis, while in non-stable fractures, continual disruption of the vasculature creates hypoxia that favors formation of cartilage, which is avascular. However, recent data suggests that non-stable fractures are more vascularized than stable fractures, that oxygen does not appear associated with differentiation of stem cells into chondrocytes and osteoblasts, that cartilage is not hypoxic, and that oxygen, not sustained hypoxia, is required for angiogenesis. These unexpected results, which contrast other published studies, are indicative of the need to better understand the complex, spatio-temporal regulation of vascularization and oxygenation in fracture healing. This work has also revealed that oxygen, along with the promotion of angiogenesis, may be novel adjuvants that can stimulate healing in select patient populations. PMID:28523266

  10. Application of Fluorescence Lifetime Imaging (FLIM) to Measure Intracellular Environments in a Single Cell.

    Science.gov (United States)

    Nakabayashi, Takakazu; Awasthi, Kamlesh; Ohta, Nobuhiro

    2017-01-01

    Fluorescence lifetime imaging (FLIM) has now been used in many bioscience fields, which comes from the quantification of fluorescence lifetime. The procedure for obtaining lifetime images is very similar to that used in fluorescence microscopy. However, obtaining reliable lifetime images requires an understanding of the theory of fluorescence lifetime, principle of FLIM systems, and evaluation procedure of intracellular environments. In this chapter, the materials, methods, and notes on FLIM measurements have been described, in conjunction with a brief explanation of the background of FLIM.

  11. Promethus Hot Leg Piping Concept

    Energy Technology Data Exchange (ETDEWEB)

    AM Girbik; PA Dilorenzo

    2006-01-24

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  12. Unexplored diversity and conservation potential of neotropical hot caves.

    Science.gov (United States)

    Ladle, Richard J; Firmino, João V L; Malhado, Ana C M; Rodríguez-Durán, Armando

    2012-12-01

    The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot-cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat-generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism. ©2012 Society for Conservation Biology.

  13. Quenching tank: Accidental drowning in hot quenching oil.

    Science.gov (United States)

    Mugadlimath, Anand B; Sane, Mandar Ramchandra; Zine, Kailash U; Hiremath, Rekha M

    2017-06-01

    We describe an unusual case of drowning in fluid other than water in an industrial setting. A 26-year-old man was working in an industry which performs surface treatment of mechanical steel parts with quenching oil. He fell into the quenching oil (which was hot due to immersion of red hot metal parts), and as he was working alone in the particular section, there was a fatal outcome. A medico-legal autopsy was performed. The causes of death were found to be multiple, with the association of drowning, extensive superficial burns and asphyxia due to laryngeal oedema. To our knowledge, it is the first report of drowning in hot quenching oil, and only nine previous observations of drowning in industrial environments have been reported in the international literature. Even though rare, these kinds of accidental deaths can be prevented in dangerous industries with proper precautions and strict adherence to standard operating procedures.

  14. Analysis of handoff strategies in macro-femto cells environment based on per-energy capacity

    KAUST Repository

    Leon, Jaime

    2012-01-01

    Placing smaller cells in a heterogeneous network can be beneficial in terms of energy because better capacities can be obtained for a given energy constraint. These type of deployments not only highlight the need for appropriate metrics to evaluate how well energy is being spent, but also raise important issues that need to be taken into account when analysing the overall use of energy. In this study, handoff strategies, bandwidth allocation and path loss calculations in different scenarios, illustrate how energy can be consumed in a more efficient way when cell size is decreased. As a result, users can experience higher capacities while spending less energy, depending whether they handoff or not, increasing the overall performance of the network. © 2012 The Institution of Engineering and Technology.

  15. Microbial fuel cells in saline and hypersaline environments: Advancements, challenges and future perspectives.

    Science.gov (United States)

    Grattieri, Matteo; Minteer, Shelley D

    2017-12-09

    This review is aimed to report the possibility to utilize microbial fuel cells for the treatment of saline and hypersaline solutions. An introduction to the issues related with the biological treatment of saline and hypersaline wastewater is reported, discussing the limitation that characterizes classical aerobic and anaerobic digestions. The microbial fuel cell (MFC) technology, and the possibility to be applied in the presence of high salinity, is discussed before reviewing the most recent advancements in the development of MFCs operating in saline and hypersaline conditions, with their different and interesting applications. Specifically, the research performed in the last 5years will be the main focus of this review. Finally, the future perspectives for this technology, together with the most urgent research needs, are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 3D Local in vivo Environment (LivE imaging for single cell protein analysis of bone tissue

    Directory of Open Access Journals (Sweden)

    Taylor Carly

    2016-09-01

    Full Text Available The molecular processes behind pathological bone remodelling seen in diseases such as osteoporosis are unclear. However, a recently developed methodological platform known as Local in vivo Environment (LivE imaging has been used to link cellular expression data to the local remodelling and mechanical environment in 2D sections of bone tissue. The method therefore can be used to give insight into which proteins are important for pathological bone remodelling. However, the cells within bone tissue exist as a 3D network. Therefore extension of LivE to accommodate 3D data may provide additional physiologically relevant information that is not possible to determine using 2D analysis alone. This will have implications for the further understanding of the cellular basis that underlies bone diseases such as osteoporosis. Here the LivE imaging technique is expanded to incorporate data from cells in a three dimensional manner via a serial sectioning technique. The methodological steps involved in the LivE imaging approach are defined and the optimisation steps performed are explained in detail.

  17. Hot conditioning equipment conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  18. Femtosecond Cooling of Hot Electrons in CdSe Quantum-Well Platelets

    NARCIS (Netherlands)

    Sippel, Philipp; Albrecht, Wiebke; van der Bok, Johanna C.; Moes, Relinde; Hannappel, Thomas; Eichberger, Rainer; Vanmaekelbergh, Daniel

    Semiconductor quantum wells are ubiquitous in high-performance optoelectronic devices such as solar cells and lasers. Understanding and controlling of the (hot) carrier dynamics is essential to optimize their performance. Here, we study hot electron cooling in colloidal CdSe quantum-well

  19. More Authors, More Institutions, and More Funding Sources: Hot Papers in Biology from 1991 to 1993.

    Science.gov (United States)

    Haiqi, Zhang

    1997-01-01

    A bibliometric study analyzed the authorship of biology periodicals, "Nature,""Science," and "Cell" from 1991 to 1993. The source data consisted of "hot papers" in biology and a sample of articles from the three periodicals. Results showed that the hot papers have more authors and participating institutions, and that funding sources are related to…

  20. Direct measurement of local dissolved oxygen concentration spatial profiles in a cell culture environment.

    Science.gov (United States)

    Kagawa, Yuki; Matsuura, Katsuhisa; Shimizu, Tatsuya; Tsuneda, Satoshi

    2015-06-01

    Controlling local dissolved oxygen concentration (DO) in media is critical for cell or tissue cultures. Various biomaterials and culture methods have been developed to modulate DO. Direct measurement of local DO in cultures has not been validated as a method to test DO modulation. In the present study we developed a DO measurement system equipped with a Clark-type oxygen microelectrode manipulated with 1 μm precision in three-dimensional space to explore potential applications for tissue engineering. By determining the microelectrode tip position precisely against the bottom plane of culture dishes with rat or human cardiac cells in static monolayer culture, we successfully obtained spatial distributions of DO in the medium. Theoretical quantitative predictions fit the obtained data well. Based on analyses of the variance between samples, we found the data reflected "local" oxygen consumption in the vicinity of the microelectrode and the detection of temporal changes in oxygen consumption rates of cultured cells was limited by the diffusion rate of oxygen in the medium. This oxygen measuring system monitors local oxygen consumption and production with high spatial resolution, and can potentially be used with recently developed oxygen modulating biomaterials to design microenvironments and non-invasively monitor local DO dynamics during culture. © 2015 Wiley Periodicals, Inc.

  1. Genes Contributing to Porphyromonas gingivalis Fitness in Abscess and Epithelial Cell Colonization Environments

    Science.gov (United States)

    Miller, Daniel P.; Hutcherson, Justin A.; Wang, Yan; Nowakowska, Zuzanna M.; Potempa, Jan; Yoder-Himes, Deborah R.; Scott, David A.; Whiteley, Marvin; Lamont, Richard J.

    2017-01-01

    Porphyromonas gingivalis is an important cause of serious periodontal diseases, and is emerging as a pathogen in several systemic conditions including some forms of cancer. Initial colonization by P. gingivalis involves interaction with gingival epithelial cells, and the organism can also access host tissues and spread haematogenously. To better understand the mechanisms underlying these properties, we utilized a highly saturated transposon insertion library of P. gingivalis, and assessed the fitness of mutants during epithelial cell colonization and survival in a murine abscess model by high-throughput sequencing (Tn-Seq). Transposon insertions in many genes previously suspected as contributing to virulence showed significant fitness defects in both screening assays. In addition, a number of genes not previously associated with P. gingivalis virulence were identified as important for fitness. We further examined fitness defects of four such genes by generating defined mutations. Genes encoding a carbamoyl phosphate synthetase, a replication-associated recombination protein, a nitrosative stress responsive HcpR transcription regulator, and RNase Z, a zinc phosphodiesterase, showed a fitness phenotype in epithelial cell colonization and in a competitive abscess infection. This study verifies the importance of several well-characterized putative virulence factors of P. gingivalis and identifies novel fitness determinants of the organism. PMID:28900609

  2. Optimizing Immobilized Enzyme Performance in Cell-Free Environments to Produce Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Belfort, Georges [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering; Grimaldi, Joseph J. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemical and Biological Engineering

    2015-01-27

    Limitations on biofuel production using cell culture (Escherichia coli, Clostridium, Saccharomyces cerevisiae, brown microalgae, blue-green algae and others) include low product (alcohol) concentrations (≤0.2 vol%) due to feedback inhibition, instability of cells, and lack of economical product recovery processes. To overcome these challenges, an alternate simplified biofuel production scheme was tested based on a cell-free immobilized enzyme system. Using this cell free system, we were able to obtain about 2.6 times higher concentrations of iso-butanol using our non-optimized system as compared with live cell systems. This process involved two steps: (i) converts acid to aldehyde using keto-acid decarboxylase (KdcA), and (ii) produces alcohol from aldehyde using alcohol dehydrogenase (ADH) with a cofactor (NADH) conversion from inexpensive formate using a third enzyme, formate dehydrogenase (FDH). To increase stability and conversion efficiency with easy separations, the first two enzymes were immobilized onto methacrylate resin. Fusion proteins of labile KdcA (fKdcA) were expressed to stabilize the covalently immobilized KdcA. Covalently immobilized ADH exhibited long-term stability and efficient conversion of aldehyde to alcohol over multiple batch cycles without fusions. High conversion rates and low protein leaching were achieved by covalent immobilization of enzymes on methacrylate resin. The complete reaction scheme was demonstrated by immobilizing both ADH and fKdcA and using FDH free in solution. The new system without in situ removal of isobutanol achieved a 55% conversion of ketoisovaleric acid to isobutanol at a concentration of 0.5 % (v/v). Further increases in titer will require continuous removal of the isobutanol using our novel brush membrane system that exhibits a 1.5 fold increase in the separation factor of isobutanol from water versus that obtained for commercial silicone rubber membranes. These bio-inspired brush membranes are based on the

  3. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Directory of Open Access Journals (Sweden)

    Jingyan Liang

    Full Text Available Hot spring or hot spa bathing (Onsen is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds.

  4. Slow cooling and highly efficient extraction of hot carriers in colloidal perovskite nanocrystals.

    Science.gov (United States)

    Li, Mingjie; Bhaumik, Saikat; Goh, Teck Wee; Kumar, Muduli Subas; Yantara, Natalia; Grätzel, Michael; Mhaisalkar, Subodh; Mathews, Nripan; Sum, Tze Chien

    2017-02-08

    Hot-carrier solar cells can overcome the Schottky-Queisser limit by harvesting excess energy from hot carriers. Inorganic semiconductor nanocrystals are considered prime candidates. However, hot-carrier harvesting is compromised by competitive relaxation pathways (for example, intraband Auger process and defects) that overwhelm their phonon bottlenecks. Here we show colloidal halide perovskite nanocrystals transcend these limitations and exhibit around two orders slower hot-carrier cooling times and around four times larger hot-carrier temperatures than their bulk-film counterparts. Under low pump excitation, hot-carrier cooling mediated by a phonon bottleneck is surprisingly slower in smaller nanocrystals (contrasting with conventional nanocrystals). At high pump fluence, Auger heating dominates hot-carrier cooling, which is slower in larger nanocrystals (hitherto unobserved in conventional nanocrystals). Importantly, we demonstrate efficient room temperature hot-electrons extraction (up to ∼83%) by an energy-selective electron acceptor layer within 1 ps from surface-treated perovskite NCs thin films. These insights enable fresh approaches for extremely thin absorber and concentrator-type hot-carrier solar cells.

  5. Getting into hot water Problematizing hot water service demand: The case of Old Cairo

    Science.gov (United States)

    Culhane, Thomas Henry

    This dissertation analyzes hot water demand and service infrastructure in two neighboring but culturally distinct communities of the urban poor in the inner-city area of central Cairo. The communities are the Historic Islamic Cairo neighborhood of Darb Al Ahmar at the foot of Al-Azhar park, and the Zurayib neighborhood of Manshiyat Nasser where the Coptic Zabaleen Recyclers live. The study focuses on the demand side of the hot water issue and involves consideration of built-environment infrastructures providing piped water, electricity, bottled gas, sewage, and the support structures (wiring and plumbing) for consumer durables (appliances such as hot water heaters, stoves, refrigerators, air conditioners) as well as water pumps and water storage tanks. The study asks the questions "How do poor communities in Cairo value hot water" and "How do cost, infrastructure and cultural preferences affect which attributes of hot water service are most highly preferred?". To answer these questions household surveys based primarily on the World Bank LSMS modules were administered by professional survey teams from Darb Al Ahmar's Aga Khan Trust for Culture and the Zabaleen's local NGO "Spirit of Youth" in their adjacent conununities in and surrounding historic Cairo. In total 463 valid surveys were collected, (231 from Darb Al Ahmar, 232 from the Zabaleen). The surveys included a contingent valuation question to explore Willingness to Pay for improved hot water service; the surveys queried household assets as proxies for income. The dissertation's findings reveal that one quarter of the residents of Darb Al Ahmar and two-thirds of the residents of Manshiyet Nasser's Zabaleen lack conventional water heating service. Instead they employ various types of stoves and self-built contraptions to heat water, usually incurring considerable risk and opportunity costs. However the thesis explores the notion that this is rational "satisficing" behavior; despite the shortcomings of such self

  6. A Network Model to Explore the Effect of the Micro-environment on Endothelial Cell Behavior during Angiogenesis

    Directory of Open Access Journals (Sweden)

    Nathan Weinstein

    2017-11-01

    Full Text Available Angiogenesis is an important adaptation mechanism of the blood vessels to the changing requirements of the body during development, aging, and wound healing. Angiogenesis allows existing blood vessels to form new connections or to reabsorb existing ones. Blood vessels are composed of a layer of endothelial cells (ECs covered by one or more layers of mural cells (smooth muscle cells or pericytes. We constructed a computational Boolean model of the molecular regulatory network involved in the control of angiogenesis. Our model includes the ANG/TIE, HIF, AMPK/mTOR, VEGF, IGF, FGF, PLCγ/Calcium, PI3K/AKT, NO, NOTCH, and WNT signaling pathways, as well as the mechanosensory components of the cytoskeleton. The dynamical behavior of our model recovers the patterns of molecular activation observed in Phalanx, Tip, and Stalk ECs. Furthermore, our model is able to describe the modulation of EC behavior due to extracellular micro-environments, as well as the effect due to loss- and gain-of-function mutations. These properties make our model a suitable platform for the understanding of the molecular mechanisms underlying some pathologies. For example, it is possible to follow the changes in the activation patterns caused by mutations that promote Tip EC behavior and inhibit Phalanx EC behavior, that lead to the conditions associated with retinal vascular disorders and tumor vascularization. Moreover, the model describes how mutations that promote Phalanx EC behavior are associated with the development of arteriovenous and venous malformations. These results suggest that the network model that we propose has the potential to be used in the study of how the modulation of the EC extracellular micro-environment may improve the outcome of vascular disease treatments.

  7. Effect of solvent environment on colloidal-quantum-dot solar-cell manufacturability and performance

    KAUST Repository

    Kirmani, Ahmad R.

    2014-06-04

    The absorbing layer in state-of-the-art colloidal quantum-dot solar cells is fabricated using a tedious layer-by-layer process repeated ten times. It is now shown that methanol, a common exchange solvent, is the main culprit, as extended exposure leaches off the surface halide passivant, creating carrier trap states. Use of a high-dipole-moment aprotic solvent eliminates this problem and is shown to produce state-of-the-art devices in far fewer steps. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Swarm Rat Chondrosarcoma Cells as an in vivo model: Lung Colonization and Effects of Tissue Environment on Tumor Growth

    Science.gov (United States)

    Morcuende, Jose A.; Stevens, Jeff W.; Scheetz, Todd E.; de Fatima Bonaldoc, Maria; Casavant, Thomas L.; Otero, Jesse E.; Soares, Marcelo B.

    2012-01-01

    Swarm rat chondrosarcoma cells have been used extensively for biochemical studies of extra-cellular matrix metabolism in cartilage. However, these cells also possess tumor-like behavior in vivo and are useful in investigation of chondrosarcoma biology. the current study was designed to develop a metastatic model using swarm rat chondrosarcoma cells, and to assess the effect of tissue-environment on tumor behavior in vivo. Tumors were implanted subcutaneously or into bone, and animals were assessed radiographically and microscopically for tumor growth and metastasis. The subcutaneous tumor grew to an average mass of 35 g, while tumor implanted into bone grew 75 mg. Transplantation of the cells into the bone led to extensive bone remodeling with invasion of the medullary cavity and destruction of the bone cortex. Light microscopy demonstrated no significant differences in the number of mitoses, cellular atypia or extracellular matrix staining between the two sites of tumor implantation. Interestingly, lung colonization was observed in none of the animals in the subcutaneous tumor injection group, while tumors colonized the lungs in 95% of the rats with tumor injected into bone. Analysis of cDNA libraries from subcutaneous and bone-transplanted tumors demonstrated a complex and diverse array of expressed transcripts, and there were significant differences in gene expression between tumors at different sites. The results of this study suggest swarm rat chondrosarcoma is a model that resembles human chondrosarcoma mimicking its ability to infiltrate and remodel local bone and to colonize the lungs. Furthermore, the interaction between host-tissue and tumor cells plays a major role in the tumor behavior in this model. Identifying these interactions will lead to further understanding of chondrosarcoma and contribute to therapeutic targets in the future. PMID:23576921

  9. Experimental Results of Thin-Film Photovoltaic Cells in a Low Density LEO Plasma Environment: Ground Tests

    Science.gov (United States)

    Galofaro, Joel T.; Vayner, Boris V.

    2006-01-01

    Plasma ground testing results, conducted at the Glenn Research Center (GRC) National Plasma Interaction (N-PI) Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory (AFRL) under the CYGNUS Space Science Technology Experiment (SSTE-4) Program. The current ground tests are aimed at characterizing the performance and survivability of thin film technologies in the harsh low earth orbital space environment where they will be flown. Measurements of parasitic current loss, charging/dielectric breakdown of cover-slide coatings and arcing threshold tests are performed for each individual cell. These measurements are followed by a series of experiments designed to test for catastrophic arc failure mechanisms. A special type of power supply, called a solar array simulator (SAS) with adjustable voltage and current limits on the supply s output, is employed to bias two adjacent cells at a predetermined voltage and current. The bias voltage is incrementally ramped up until a sustained arc results. Sustained arcs are precursors to catastrophic arc failure where the arc current rises to a maximum value for long timescales often ranging between 30 to 100 sec times. Normal arcs by comparison, are short lived events with a timescale between 10 to 30 sec. Sustained arcs lead to pyrolization with extreme cell damage and have been shown to cause the loss of entire array strings in solar arrays. The collected data will be used to evaluate the suitability of thin-film photovoltaic technologies for future space operations.

  10. Hot-spots in tapwaterleidingen

    NARCIS (Netherlands)

    Wolferen, J. van; Sluis, S.M. van der

    2002-01-01

    ln opdracht van de VNI is een aantal berekeningen uitgevoerd voor het vaststellen van aanvullende richtlijnen in verband met hot-spots in tapwaterleidingen. Hierbij is deels voortgebouwd op berekeningen die reeds eerder in opdracht van Novem zijn uitgevoerd t.b.v. ISSO publicatie 55.1, Handleiding

  11. Hot Corrosion in Gas Turbines.

    Science.gov (United States)

    1983-04-27

    in hot corrosion under some circumstances, because its role seems to be principally through reduction of NagSO, or erosion by pyrolytic graphite...same morphology could be produced either by spray -coating with NaxSO, or by diffusing NIS into the cut- edge region under argon at temperature and then

  12. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  13. Analysis of Dowlink Macro-Femto Cells Environment Based on Per-Energy Capacity

    KAUST Repository

    León, Jaime

    2012-05-01

    Placing smaller cells in a heterogeneous cellular network can be beneficial in terms of energy because better capacities can be obtained for a given energy constraint. These type of deployments not only highlight the need for appropriate metrics to evaluate how well energy is being spent, but also raise important issues that need to be taken into account when analysing the overall use of energy. In this work, handoff strategies, bandwidth allocation, and path loss models in different scenarios, illustrate how energy can be consumed in a more efficient way when cell size is decreased. A handoff strategy based on per-energy capacity is studied in order to give priority to a more energy efficient handoff option. Energy can also be spent more adequately if the transmit power is adjusted as a function of interference. As a result, users can experience higher capacities while spending less energy, depending whether they handoff or not, increasing the overall performance of the network in terms of energy efficiency.

  14. Stem Cell Enrichment with Selectin Receptors: Mimicking the pH Environment of Trauma

    Directory of Open Access Journals (Sweden)

    Michael R. King

    2013-09-01

    Full Text Available The isolation of hematopoietic stem and progenitor cells (HSPCs is critical for transplantation therapy and HSPC research, however current isolation techniques can be prohibitively expensive, time-consuming, and produce variable results. Selectin-coated microtubes have shown promise in rapidly isolating HSPCs from human bone marrow, but further purification of HSPCs remains a challenge. Herein, a biomimetic device for HSPC isolation is presented to mimic the acidic vascular microenvironment during trauma, which can enhance the binding frequency between L-selectin and its counter-receptor PSGL-1 and HSPCs. Under acidic pH conditions, L-selectin coated microtubes enhanced CD34+ HSPC adhesion, as evidenced by decreased cell rolling velocity and increased rolling flux. Dynamic light scattering was utilized as a novel sensor to confirm an L-selectin conformational change under acidic conditions, as previously predicted by molecular dynamics. These results suggest that mimicking the acidic conditions of trauma can induce a conformational extension of L-selectin, which can be utilized for flow-based, clinical isolation of HSPCs.

  15. Metastasis Suppressor Genes: At the Interface Between the Environment and Tumor Cell Growth

    Science.gov (United States)

    Hurst, Douglas R.; Welch, Danny R.

    2013-01-01

    The molecular mechanisms and genetic programs required for cancer metastasis are sometimes overlapping, but components are clearly distinct from those promoting growth of a primary tumor. Every sequential, rate-limiting step in the sequence of events leading to metastasis requires coordinated expression of multiple genes, necessary signaling events, and favorable environmental conditions or the ability to escape negative selection pressures. Metastasis suppressors are molecules that inhibit the process of metastasis without preventing growth of the primary tumor. The cellular processes regulated by metastasis suppressors are diverse and function at every step in the metastatic cascade. As we gain knowledge into the molecular mechanisms of metastasis suppressors and cofactors with which they interact, we learn more about the process, including appreciation that some are potential targets for therapy of metastasis, the most lethal aspect of cancer. Until now, metastasis suppressors have been described largely by their function. With greater appreciation of their biochemical mechanisms of action, the importance of context is increasingly recognized especially since tumor cells exist in myriad microenvironments. In this review, we assemble the evidence that selected molecules are indeed suppressors of metastasis, collate the data defining the biochemical mechanisms of action, and glean insights regarding how metastasis suppressors regulate tumor cell communication to–from microenvironments. PMID:21199781

  16. New fixed-point mini-cell to investigate thermocouple drift in a high-temperature environment under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, M.; Vlahovic, L.; Rondinella, V.V. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe, (Germany); Sadli, M.; Failleau, G. [Laboratoire Commun de Metrologie, LNE-Cnam, Saint-Denis, (France); Fuetterer, M.; Lapetite, J.M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten, (Netherlands); Fourrez, S. [Thermocoax, 8 rue du pre neuf, F-61100 St Georges des Groseillers, (France)

    2015-07-01

    Temperature measurements in the nuclear field require a high degree of reliability and accuracy. Despite their sheathed form, thermocouples subjected to nuclear radiations undergo changes due to radiation damage and transmutation that lead to significant EMF drift during long-term fuel irradiation experiment. For the purpose of a High Temperature Reactor fuel irradiation to take place in the High Flux Reactor Petten, a dedicated fixed-point cell was jointly developed by LNE-Cnam and JRC-IET. The developed cell to be housed in the irradiation rig was tailor made to quantify the thermocouple drift during the irradiation (about two year duration) and withstand high temperature (in the range 950 deg. C - 1100 deg. C) in the presence of contaminated helium in a graphite environment. Considering the different levels of temperature achieved in the irradiation facility and the large palette of thermocouple types aimed at surveying the HTR fuel pebble during the qualification test both copper (1084.62 deg. C) and gold (1064.18 deg. C) fixed-point materials were considered. The aim of this paper is to first describe the fixed-point mini-cell designed to be embedded in the reactor rig and to discuss the preliminary results achieved during some out of pile tests as much as some robustness tests representative of the reactor scram scenarios. (authors)

  17. [Application of Whole-cell Biosensor ADP1_pWHlux for Acute Toxicity Detection in Water Environment].

    Science.gov (United States)

    Tang, Hui; Song, Yi-zhi; Jiang, Bo; Chen, Guang-yu; Jia, Jian-li; Zhang, Xu; Li, Guang-he

    2015-10-01

    A whole-cell biosensor acinetobacter ADP1_pWHlux was constructed by genetic engineering for detecting acute toxicity, so as to overcome the harsh application conditions when detecting acute toxicity using natural luminescent bacteria or whole-cell biosensor constructed by model microorganisms as the host cell. Detection methods, detection sensitivity and detection range of acinetobacter ADP1_pWHlux were studied. The results showed that the luminescence of ADP1_pWHlux was inhibited by acute poison, poison dose and inhibition of luminescence exhibit dose-response relationship. ADPL_pWHlux was respond to 4 mg x L(-1) HgCl2 within 5 min. The detection limit for HgCl2 was 0.04 mg x L(-1). The detectable effects for indicators of Be2+, Ba2+, Cu2+, Ni2+ in standards for drinking water quality were obvious. The detection range of Be2+, Ba2+, Cu2+ were 0.025-250 mg x L(-1), the detection range of Ni2+, was 0.0025-250 mg x L(-1), the detection limit of Pb2+, BrO3(-) , ClO2(-) were 0.002 5 mg x L(-1), the detection limit of ClO3(-) was 0.025 mg x L(-1). The whole-cell biosensor ADPl_pWHlux detection method has been applied to evaluate acute toxicity in water environment of Qinghe river in Beijing, indicating the established method can be used to detect contaminated water samples.

  18. OUT Success Stories: Solar Hot Water Technology

    Energy Technology Data Exchange (ETDEWEB)

    Clyne, R.

    2000-08-31

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  19. OUT Success Stories: Solar Hot Water Technology

    Science.gov (United States)

    Clyne, R.

    2000-08-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  20. Iron losses during desulphurisation of hot metal

    OpenAIRE

    Magnelöv, Marianne

    2014-01-01

    After injection of calcium carbide and magnesium during desulphurisation of hot metal, the slag is normally solid and contains large amounts of iron. Besides the enclosed iron droplets in the slag, drawn-off hot metal during slag skimming also accounts for iron losses during desulphurisation of hot metal. Iron losses during hot metal desulphurisation using both calcium carbide (mono-injection), and calcium carbide and magnesium (co-injection), have been studied by large-scale investigations o...

  1. The genome of th17 cell-inducing segmented filamentous bacteria reveals extensive auxotrophy and adaptations to the intestinal environment.

    Science.gov (United States)

    Sczesnak, Andrew; Segata, Nicola; Qin, Xiang; Gevers, Dirk; Petrosino, Joseph F; Huttenhower, Curtis; Littman, Dan R; Ivanov, Ivaylo I

    2011-09-15

    Perturbations of the composition of the symbiotic intestinal microbiota can have profound consequences for host metabolism and immunity. In mice, segmented filamentous bacteria (SFB) direct the accumulation of potentially proinflammatory Th17 cells in the intestinal lamina propria. We present the genome sequence of SFB isolated from monocolonized mice, which classifies SFB phylogenetically as a unique member of Clostridiales with a highly reduced genome. Annotation analysis demonstrates that SFB depend on their environment for amino acids and essential nutrients and may utilize host and dietary glycans for carbon, nitrogen, and energy. Comparative analyses reveal that SFB are functionally related to members of the genus Clostridium and several pathogenic or commensal "minimal" genera, including Finegoldia, Mycoplasma, Borrelia, and Phytoplasma. However, SFB are functionally distinct from all 1200 examined genomes, indicating a gene complement representing biology relatively unique to their role as a gut commensal closely tied to host metabolism and immunity. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Proton transport and the water environment in nafion fuel cell membranes and AOT reverse micelles.

    Science.gov (United States)

    Spry, D B; Goun, A; Glusac, K; Moilanen, David E; Fayer, M D

    2007-07-04

    The properties of confined water and diffusive proton-transfer kinetics in the nanoscopic water channels of Nafion fuel cell membranes at various hydration levels are compared to water in a series of well-characterized AOT reverse micelles with known water nanopool sizes using the photoacid pyranine as a molecular probe. The side chains of Nafion are terminated by sulfonate groups with sodium counterions that are arrayed along the water channels. AOT has sulfonate head groups with sodium counterions that form the interface with the reverse micelle's water nanopool. The extent of excited-state deprotonation is observed by steady-state fluorescence measurements. Proton-transfer kinetics and orientational relaxation are measured by time-dependent fluorescence using time-correlated single photon counting. The time dependence of deprotonation is related to diffusive proton transport away from the photoacid. The fluorescence reflecting the long time scale proton transport has an approximately t-0.8 power law decay in contrast to bulk water, which has a t-3/2 power law. For a given hydration level of Nafion, the excited-state proton transfer and the orientational relaxation are similar to those observed for a related size AOT water nanopool. The effective size of the Nafion water channels at various hydration levels are estimated by the known size of the AOT reverse micelles that display the corresponding proton-transfer kinetics and orientational relaxation.

  3. Differentiation and Distribution of Marrow Stem Cells in Flex-Flow Environments Demonstrate Support of the Valvular Phenotype.

    Directory of Open Access Journals (Sweden)

    Sasmita Rath

    Full Text Available For treatment of critical heart valve diseases, prosthetic valves perform fairly well in most adults; however, for pediatric patients, there is the added requirement that the replacement valve grows with the child, thus extremely limiting current treatment options. Tissue engineered heart valves (TEHV, such as those derived from autologous bone marrow stem cells (BMSCs, have the potential to recapitulate native valve architecture and accommodate somatic growth. However, a fundamental pre-cursor in promoting directed integration with native tissues rather than random, uncontrolled growth requires an understanding of BMSC mechanobiological responses to valve-relevant mechanical environments. Here, we report on the responses of human BMSC-seeded polymer constructs to the valve-relevant stress states of: (i steady flow alone, (ii cyclic flexure alone, and (iii the combination of cyclic flexure and steady flow (flex-flow. BMSCs were seeded onto a PGA: PLLA polymer scaffold and cultured in static culture for 8 days. Subsequently, the aforementioned mechanical conditions, (groups consisting of steady flow alone-850ml/min, cyclic flexure alone-1 Hz, and flex-flow-850ml/min and 1 Hz were applied for an additional two weeks. We found samples from the flex-flow group exhibited a valve-like distribution of cells that expressed endothelial (preference to the surfaces and myofibroblast (preference to the intermediate region phenotypes. We interpret that this was likely due to the presence of both appreciable fluid-induced shear stress magnitudes and oscillatory shear stresses, which were concomitantly imparted onto the samples. These results indicate that flex-flow mechanical environments support directed in vitro differentiation of BMSCs uniquely towards a heart valve phenotype, as evident by cellular distribution and expression of specific gene markers. A priori guidance of BMSC-derived, engineered tissue growth under flex-flow conditions may serve to

  4. Uncertainty and innovation: Understanding the role of cell-based manufacturing facilities in shaping regulatory and commercialization environments.

    Science.gov (United States)

    Isasi, Rosario; Rahimzadeh, Vasiliki; Charlebois, Kathleen

    2016-12-01

    The purpose of this qualitative study is to elucidate stakeholder perceptions of, and institutional practices related to cell-based therapies and products (CTP) regulation and commercialization in Canada. The development of reproducible, safe and effective CTPs is predicated on regulatory and commercialization environments that enable innovation. Manufacturing processes constitute a critical step for CTP development in this regard. The road from CTP manufacturing to translation in the clinic, however, has yet to be paved. This study aims to fill an empirical gap in the literature by exploring how CTP manufacturing facilities navigate Canadian regulatory and commercialization environments, which together drive the translation of novel CTPs from bench to bedside. Using the multi-level model of practice-driven institutional change proposed by Smets et al., we demonstrate how CTP manufacturing practices are governed by established standards, yet meaningfully shape higher-order regulatory and commercial norms in CTP research and development. We identify four key themes that undergird such processes of innovation: 1) managing regulatory uncertainty, which stems from an inability to classify CTPs within existing regulatory categories for approval and commercialization purposes; 2) building a 'business case' whereby a CTP's market potential is determined in large part by proving its safety and effectiveness; 3) standardizing manufacturing procedures that mobilize CTPs from a research and development phase to a commercialization one; and 4) networking between researchers and regulators to develop responsible commercialization processes that reflect the uniqueness of CTPs as distinct from other biologics and medical devices.

  5. Influence of dynamic flow environment on nanoparticle-protein corona: From protein patterns to uptake in cancer cells.

    Science.gov (United States)

    Palchetti, Sara; Pozzi, Daniela; Capriotti, Anna Laura; Barbera, Giorgia La; Chiozzi, Riccardo Zenezini; Digiacomo, Luca; Peruzzi, Giovanna; Caracciolo, Giulio; Laganà, Aldo

    2017-05-01

    The fast growing use of nanoparticles (NPs) in biotechnology and biomedicine raises concerns about human health and the environment. When introduced in physiological milieus, NPs adsorb biomolecules (especially proteins) forming the so-called protein corona (PC). As it is the PC that mostly interacts with biological systems, it represents a major element of the NPs' biological identity with impact on nanotoxicology, nanosafety and targeted delivery of nanomedicines. To date, NP-protein interactions have been largely investigated in vitro, but this condition is far from mimicking the dynamic nature of physiological environments. Here we investigate the effect of shear stress on PC by exposing lipid NPs with different surface chemistry (either unmodified and PEGylated) to circulating fetal bovine serum (FBS). PC formed upon in vitro incubation was used as a reference. We demonstrate that PC is significantly influenced by exposure to dynamic flow and that changes in PC composition are dependent on both exposure time and NP's surface chemistry. Notably, alterations induced by dynamic flow affected cellular uptake of lipid NPs in both human cervical cancer (HeLa) and human breast adenocarcinoma (MCF7) cell lines. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Heat inactivation of wine spoilage yeast Dekkera bruxellensis by hot water treatment

    National Research Council Canada - National Science Library

    Fabrizio, V; Vigentini, I; Parisi, N; Picozzi, C; Compagno, C; Foschino, R

    2015-01-01

    .... The thermal inactivation of D. bruxellensis cells by hot water treatment proves to be efficacious and easy to perform, provided that the holding time at the killing temperature takes into account the filling time of the vessel...

  7. Sex Differences in Acclimation to a Hot-Dry Environment,

    Science.gov (United States)

    1980-01-01

    and Goldman, R. F., 1980, Physiological responses of men and women to humid and dry heat. Journal of Appplied Physiology: 49, (in press). Taylor, H. L...regard to experimental risk and gave their written informed consent. The physical characteristics of subjects are summarized in Table 1. All...preacclimation conditions were relatively similar for both sexes. The two major differences in terms of physical characteristics between males and females

  8. Efficacy of Nutritional Ergogenic Aids in Hot Environments

    Science.gov (United States)

    2010-01-01

    rbohydratcs (C HO), to fuel high training volumes (American College of Sports Medicine, 2009). Beyond a alorically adequatc diet rich in CHO, cndurance...1387. Ferreira, G.M., Guerra, G.c. and Guerra, RO. (2005) Eff~t of caffeine in che performance of cyclists under high thermal risk. [article in...ofApplitd Physiology9 1, 2017-2023. Pandolf, K.B. (1979) Effects of physical training and cardiorespiratory fitness on exercise-he:.l,T [Olerance: recent

  9. Aerobic Performance is Degraded, Despite Modest Hypothermia, In Hot Environments

    Science.gov (United States)

    2010-01-01

    the time trial. Volunteers performed three to four familiarization trials to reduce training and learning effects, as all volunteers were novice... cyclists (13). These sessions mimicked exper- imental trials in every way, except they took place outside the environmental chamber at room temperature...completed, volunteers were provided with feedback on their perfor- mance as motivation to improve with each subsequent training bout. During the 2-wk

  10. Effects of hot environments on bone growth in rats

    African Journals Online (AJOL)

    minants. However, physiological effects of high tem- perature on body growth are not well defined. ... and water intake, bone and serum mineral contents using an atomic absorption spectrophotometer, bone re- ... contents and Acp-ase activities were lower in lot (2) than. 1. (24°C; ad lib.) 3. (24°C; restricted). 2. (WC; ad lib.).

  11. Effects of hot environments on bone growth in rats

    African Journals Online (AJOL)

    using an atomic absorption spectrophotometer, bone re- modelling enzymes using a spectrophotometer and some hormone concentrations in serum using radio-immuno assay methods. Results and Discussion. Body mass, bone mass, bone length, alkaline phosphatase. (Alp-ase) and acid phosphatase (Acp-ase) activities ...

  12. The risk of thermal stress regarding hot environments in industries

    OpenAIRE

    Morgado, Mariana; Talaia, Mário; Teixeira, Leonor

    2015-01-01

    O desconforto térmico é uma causa de insatisfação no trabalho fortemente associada a riscos de acidentes de trabalho. É neste contexto que o presente trabalho se insere, tendo como objetivo, através de índices térmicos, a identificação do padrão térmico dos espaços em estudo e dos postos de trabalho com maior risco a stress térmico, bem como ao conhecimento das sensações térmicas dos trabalhadores. O Departamento de Higiene e Segurança das indústrias estudadas valorizou os resultados para cri...

  13. Anxiogenic CO2 Stimulus Elicits Exacerbated Hot Flash-like Responses in a Rat Menopause Model and Hot Flashes in Menopausal Women

    Science.gov (United States)

    Federici, Lauren M.; Roth, Sarah Dorsey; Krier, Connie; Fitz, Stephanie D.; Skaar, Todd; Shekhar, Anantha; Carpenter, Janet S.; Johnson, Philip L.

    2016-01-01

    Objective Since longitudinal studies determined that anxiety is a strong risk factor for hot flashes, we hypothesized that an anxiogenic stimulus that signals air hunger (hypercapnic, normoxic gas) would trigger an exacerbated hot flash-associated increase in tail skin temperature (TST) in a rat ovariectomy (OVEX) model of surgical menopause and hot flashes in symptomatic menopausal women. We also assessed TST responses in OVEX serotonin transporter (SERT)+/− rats that models a common polymorphism that is associated with increased climacteric symptoms in menopausal women and increases in anxiety traits. Methods OVEX and sham-OVEX rats (initial experiment) and wildtype and SERT+/− OVEX rats (subsequent experiment) were exposed to a 5 min infusion of 20%CO2 normoxic gas while measuring TST. Menopausal women were given brief 20% and 35%CO2 challenges, and hot flashes were self-reported and objectively verified. Results Compared to controls, OVEX rats had exacerbated increases in TST, and SERT+/− OVEX rats had prolonged TST increases following CO2. Most women reported mild/moderate hot flashes after CO2 challenges, and the hot flash severity to CO2 was positively correlated with daily hot flash frequency. Conclusions The studies demonstrate that this anxiogenic stimulus is capable of inducing cutaneous vasomotor responses in OVEX rats, and eliciting hot flashes in menopausal women. In rats, the severity of the response was mediated by loss of ovarian function and increased anxiety traits (SERT+/−), and, in women, by daily hot flash frequency. These findings may provide insights into anxiety related triggers and genetic risk factors for hot flashes in thermoneutral environments. PMID:27465717

  14. Anxiogenic CO2 stimulus elicits exacerbated hot flash-like responses in a rat menopause model and hot flashes in postmenopausal women.

    Science.gov (United States)

    Federici, Lauren M; Roth, Sarah Dorsey; Krier, Connie; Fitz, Stephanie D; Skaar, Todd; Shekhar, Anantha; Carpenter, Janet S; Johnson, Philip L

    2016-11-01

    As longitudinal studies determined that anxiety is a strong risk factor for hot flashes, we hypothesized that an anxiogenic stimulus that signals air hunger (hypercapnic, normoxic gas) would trigger an exacerbated hot flash-associated increase in tail skin temperature (TST) in a rat ovariectomy (OVEX) model of surgical menopause and hot flashes in symptomatic postmenopausal women. We also assessed TST responses in OVEX serotonin transporter (SERT) rats that models a common polymorphism that is associated with increased climacteric symptoms in postmenopausal women and increases in anxiety traits. OVEX and sham-OVEX rats (initial experiment) and wildtype and SERT OVEX rats (subsequent experiment) were exposed to a 5-minute infusion of 20% carbon dioxide (CO2) normoxic gas while measuring TST. Postmenopausal women were given brief 20% and 35% CO2 challenges, and hot flashes were self-reported and objectively verified. Compared to controls, OVEX rats had exacerbated increases in TST, and SERT OVEX rats had prolonged TST increases following CO2. Most women reported mild/moderate hot flashes after CO2 challenges, and the hot flash severity to CO2 was positively correlated with daily hot flash frequency. The studies demonstrate that this anxiogenic stimulus is capable of inducing cutaneous vasomotor responses in OVEX rats, and eliciting hot flashes in postmenopausal women. In rats, the severity of the response was mediated by loss of ovarian function and increased anxiety traits (SERT), and, in women, by daily hot flash frequency. These findings may provide insights into anxiety-related triggers and genetic risk factors for hot flashes in thermoneutral environments.

  15. The Role of Water Occlusion for the Definition of a Protein Binding Hot-Spot.

    Science.gov (United States)

    Moreira, Irina S

    2015-01-01

    Biological systems rely on the establishment of interactions between biomolecules, which take place in the aqueous environment of the cell. It was already demonstrated that a small set of residues at the interface, Hot-Spots(HS), contributes significantly to the binding free energy. However, these energetic determinants of affinity and specificity are still not fully understood. Moreover, the contribution of water to their HS character is also poorly characterized. In this review, we have focused on the structural data available that support the occlusion of HS from solvent, and therefore the "O-ring theory"not only on protein-protein but also on protein-DNA complexes. We also emphasized the use of Solvent Accessible Surface Area (SASA) features in a variety of machine-learning approaches that aim to detect binding HS.

  16. The impact of enriched environment and transplantation of murine cortical embryonic stem cells on recovery from controlled cortical contusion injury.

    Science.gov (United States)

    Peruzzaro, Sarah T; Gallagher, Jonathan; Dunkerson, Jacob; Fluharty, Sarah; Mudd, David; Hoane, Michael R; Smith, Jeffrey S

    2013-01-01

    The effectiveness of embryonic stem cell (eSC) therapy has been explored in many models of neurological disease and several research groups have shown that eSC treatment leads to improved outcomes in pre-clinical models of traumatic brain injury (TBI). Though functional recovery occurs, few surviving eSCs appear to develop neuronal characteristics; instead the majority of the surviving eSC express glial phenotypes. Additionally, researchers have shown that enriching the post-surgical environment of the subject promotes functional recovery following TBI. The purpose of the current project was to determine if post-surgical environmental enrichment (EE) impacts the survival, migration, and integration of eSCs in a rodent model of TBI and if the presence of these cells lead to improved outcomes. In the current study, the medial frontal cortex (MFC) of rats was injured using a controlled cortical impact (CCI) device. Immediately following injury the rats were placed into either EE or standard environment (SE) housing and then seven days post-injury rats received either murine cortical eSC or media. Behavioral testing consisted of the Morris water maze (MWM), Barnes Maze (BM), and Rotarod tasks (RR). On the MWM task, TBI/eSC/EE animals performed as well as the Sham/SE and Sham/EE groups. The TBI/eSC/SE, TBI/Media/EE, and TBI/Media/SE groups were impaired compared to the controls. By the end of training on the BM there were no differences between the Sham, TBI/Media/EE, and TBI/eSC/EE groups. On the RR task all animals placed in the EE performed equally well and significantly better than their SE housed counterparts. By the end of training on the RR task, the TBI/eSC/EE group performed as well as the sham counterparts, and though not significant they also surpassed the performance of the injured animals that received enrichment or eSC treatment alone. Combing therapeutic strategies with enriching the post-injury environment is likely to be an important addition to

  17. A rapid live-cell ELISA for characterizing antibodies against cell surface antigens of Chlamydomonas reinhardtii and its use in isolating algae from natural environments with related cell wall components.

    Science.gov (United States)

    Jiang, Wenzhi; Cossey, Sarah; Rosenberg, Julian N; Oyler, George A; Olson, Bradley J S C; Weeks, Donald P

    2014-09-25

    Cell walls are essential for most bacteria, archaea, fungi, algae and land plants to provide shape, structural integrity and protection from numerous biotic and abiotic environmental factors. In the case of eukaryotic algae, relatively little is known of the composition, structure or mechanisms of assembly of cell walls in individual species or between species and how these differences enable algae to inhabit a great diversity of environments. In this paper we describe the use of camelid antibody fragments (VHHs) and a streamlined ELISA assay as powerful new tools for obtaining mono-specific reagents for detecting individual algal cell wall components and for isolating algae that share a particular cell surface component. To develop new microalgal bioprospecting tools to aid in the search of environmental samples for algae that share similar cell wall and cell surface components, we have produced single-chain camelid antibodies raised against cell surface components of the single-cell alga, Chlamydomonas reinhardtii. We have cloned the variable-region domains (VHHs) from the camelid heavy-chain-only antibodies and overproduced tagged versions of these monoclonal-like antibodies in E. coli. Using these VHHs, we have developed an accurate, facile, low cost ELISA that uses live cells as a source of antigens in their native conformation and that requires less than 90 minutes to perform. This ELISA technique was demonstrated to be as accurate as standard ELISAs that employ proteins from cell lysates and that generally require >24 hours to complete. Among the cloned VHHs, VHH B11, exhibited the highest affinity (EC50 algae sharing cell surface components with C. reinhardtii in water samples from natural environments. In addition, mCherry-tagged VHH B11 was used along with fluorescence activated cell sorting (FACS) to select individual axenic isolates of presumed wild relatives of C. reinhardtii and other Chlorphyceae from the same environmental samples. Camelid antibody

  18. Degradation of graphene coated copper in simulated proton exchange membrane fuel cell environment: Electrochemical impedance spectroscopy study

    Science.gov (United States)

    Ren, Y. J.; Anisur, M. R.; Qiu, W.; He, J. J.; Al-Saadi, S.; Singh Raman, R. K.

    2017-09-01

    Metallic materials are most suitable for bipolar plates of proton exchange membrane fuel cell (PEMFC) because they possess the required mechanical strength, durability, gas impermeability, acceptable cost and are suitable for mass production. However, metallic bipolar plates are prone to corrosion or they can passivate under PEMFC environment and interrupt the fuel cell operation. Therefore, it is highly attractive to develop corrosion resistance coating that is also highly conductive. Graphene fits these criteria. Graphene coating is developed on copper by chemical vapor deposition (CVD) with an aim to improving corrosion resistance of copper under PEMFC condition. The Raman Spectroscopy shows the graphene coating to be multilayered. The electrochemical degradation of graphene coated copper is investigated by electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 solution at room temperature. After exposure to the electrolyte for up to 720 h, the charge transfer resistance (Rt) of the graphene coated copper is ∼3 times greater than that of the bare copper, indicating graphene coatings could improve the corrosion resistance of copper bipolar plates.

  19. The critical relation between chemical stability of cations and water in anion exchange membrane fuel cells environment

    Science.gov (United States)

    Dekel, Dario R.; Willdorf, Sapir; Ash, Uri; Amar, Michal; Pusara, Srdjan; Dhara, Shubhendu; Srebnik, Simcha; Diesendruck, Charles E.

    2018-01-01

    Anion exchange membrane fuel cells can potentially revolutionize energy storage and delivery; however, their commercial development is hampered by a significant technological impedance: the chemical decomposition of the anion exchange membranes during operation. The hydroxide anions, while transported from the cathode to the anode, attack the positively charged functional groups in the polymer membrane, neutralizing it and suppressing its anion-conducting capability. In recent years, several new quaternary ammonium salts have been proposed to address this challenge, but while they perform well in ex-situ chemical studies, their performance is very limited in real fuel cell studies. Here, we use experimental work, corroborated by molecular dynamics modeling to show that water concentration in the environment of the hydroxide anion, as well as temperature, significantly impact its reactivity. We compare different quaternary ammonium salts that have been previously studied and test their stabilities in the presence of relatively low hydroxide concentration in the presence of different amounts of solvating water molecules, as well as different temperatures. Remarkably, with the right amount of water and at low enough temperatures, even quaternary ammonium salts which are considered "unstable", present significantly improved lifetime.

  20. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    1998-12-22

    Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the filter elements in these systems will have to be made of ceramic materials to withstand goal service temperatures of 1600 F or higher. Recent demonstration projects and pilot plant tests have indicated that the current generation of ceramic hot gas filters (cross-flow and candle configurations) are failing prematurely. Two of the most promising materials that have been extensively evaluated are clay-bonded silicon carbide and alumina-mullite porous monoliths. These candidates, however, have been found to suffer progressive thermal shock fatigue damage, as a result of rapid cooling/heating cycles. Such temperature changes occur when the hot filters are back-pulsed with cooler gas to clean them, or in process upset conditions, where even larger gas temperature changes may occur quickly and unpredictably. In addition, the clay-bonded silicon carbide materials are susceptible to chemical attack of the glassy binder phase that holds the SiC particles together, resulting in softening, strength loss, creep, and eventual failure.

  1. A case of familial hot tub lung

    Directory of Open Access Journals (Sweden)

    Yoshihiro Kitahara

    2016-01-01

    Full Text Available Hot tub lung is a lung disease caused by Mycobacterium avium complex. We report the first case of familial hot tub lung appearing simultaneously in a husband and wife. Our case supports the consideration that hot tub lung is a hypersensitivity pneumonitis rather than an infectious lung disease. It also suggests that the state of hot tub lung changes seasonally depending on temperature variations, in a manner similar to summer-type hypersensitivity pneumonitis. This case demonstrates similarities between hot tub lung and summer-type hypersensitivity pneumonitis in regards to familial occurrence and seasonal changes in the disease state.

  2. Exercise-related complications in sickle cell trait.

    Science.gov (United States)

    Tripette, Julien; Hardy-Dessources, Marie-Dominique; Romana, Marc; Hue, Olivier; Diaw, Mor; Samb, Abdoulaye; Diop, Saliou; Connes, Philippe

    2013-01-01

    This review presents the epidemiological data regarding the exercise-related complication in exercising sickle cell trait carriers, and focuses on the different potential mechanisms that could be involved in these adverse events, such as hemorheological alterations, inflammation, vascular adhesion of circulating blood cells, oxidative stress and impaired nitric oxide metabolism. We also discuss the effects of different modulating factors such as vascular function, environment (hot temperature), hydration status, physical fitness, exercise intensity and genetic factors.

  3. Cell and Tissue Organization in the Circulatory and Ventilatory Systems Volume 1 Signaling in Cell Organization, Fate, and Activity, Part A Cell Structure and Environment

    CERN Document Server

    Thiriet, Marc

    2011-01-01

    The volumes in this authoritative series present a multidisciplinary approach to modeling and simulation of flows in the cardiovascular and ventilatory systems, especially multiscale modeling and coupled simulations. The cardiovascular and respiratory systems are tightly coupled, as their primary function is to supply oxygen to and remove carbon dioxide from the body's cells. Because physiological conduits have deformable and reactive walls, macroscopic flow behavior and prediction must be coupled to nano- and microscopic events in a corrector scheme of regulated mechanisms. Therefore, investigation of flows of blood and air in physiological conduits requires an understanding of the biology, chemistry, and physics of these systems together with the mathematical tools to describe their functioning.  The present volume is devoted to cellular events that allow adaptation to environmental conditions, particularly mechanotransduction. It begins with cell organization and a survey of cell types in the vasculatur...

  4. Phototrophy in Mildly Acidic Hot Spring Ecosystems

    Science.gov (United States)

    Fecteau, K.; Boyd, E. S.; Shock, E.

    2014-12-01

    Microbial light-driven reduction of carbon in continental hydrothermal ecosystems is restricted to environments at temperatures less than 73 °C. In circumneutral and alkaline systems bacterial phototrophs (cyanobacteria and anoxygenic phototrophs) are suggested to be principally responsible for this activity whereas algal (i.e., eukaryotic) phototrophs are thought to be responsible for this activity in acidic systems. In Yellowstone National Park numerous examples of phototrophic microbial communities exist at high and low pH, while hot springs with intermediate pH (values 3-5) are rare and commonly dilute. It is thought that the transition from algal photosynthesis to bacterial photosynthesis occurs within this pH range. To test this hypothesis, we sequenced bacterial and eukaryal small subunit ribosomal RNA genes, analyzed pigments, and performed comprehensive geochemical measurements from 12 hot springs within this pH realm. At all sites, the largest phototrophic population was either comprised of Cyanobacteria or affiliated with the algal order Cyanidiales, which are ubiquitous in acidic springs, yet abundant sequences of both lineages were present in 8 of the 12 sites. Nevertheless, some of these samples exceeded the known temperature limit of the algae (56 °C), suggesting that these populations are dead or inactive. Indeed, one site yielded evidence for a large Cyanidiales population as the only phototrophs present, yet an experiment at the time of sampling failed to demonstrate light-driven carbon fixation, and analysis of extracted pigments showed a large amount of the chlorophyll degradation product pheophorbide a and very little intact chlorophyll, indicating photosynthesis occurred at this site when conditions were different. Our observations illustrate the dynamic nature of these systems that may be transiently conducive to photosynthesis, which may open niches for phototrophs of both domains and likely played a role in the evolution of photosynthesis.

  5. Urban Outdoor Thermal Comfort of The Hot-Humid Region

    Directory of Open Access Journals (Sweden)

    Abu Bakar A.

    2016-01-01

    Full Text Available The study on outdoor comfort is becoming popular due to the fact that the thermoregulatory model is seen as inadequate in explaining outdoor thermal comfort conditions. Hot-humid region can be said as experiencing a critical environmental condition because of its constantly high temperature and humidity throughout the year. Thus, this study focus on the assessment of thermal comfort of outdoor urban spaces in Kuala Lumpur, Malaysia (3° 9’N and 101° 44’E. Survey on human response towards outdoor thermal comfort in hot-humid climate of Kuala Lumpur, Malaysia was carried out during day time between 0900h to 1800h along with measurement of environmental parameters such as air temperature (°C, wind velocity (m/s, radiant temperature (°C, relative humidity (% and solar radiation (lux. A total of 123 samples were involved in this study which took place within four sites around Kuala Lumpur. Survey results were then correlated with the environmental parameters to further develop the comfort zone for hot-humid outdoor environment specifically for Kuala Lumpur and, generally, for hot-humid regions.

  6. Kelly Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center preliminary design. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Longyear, A.B. (ed.)

    1980-08-01

    A Phase 1 Preliminary Design, Construction Planning and Economic Analysis has been conducted for the Kelly Hot Spring Agricultural Center in Modoc County, California. The core activity is a 1360 breeding sow, swine raising complex that utilizes direct heat energy from the Kelly Hot Spring geothermal resource. The swine is to be a totally confined operation for producing premium pork in controlled-environment facilities. The complex contains a feed mill, swine raising buildings and a complete waste management facility that produces methane gas to be delivered to a utility company for the production of electricity. The complex produces 6.7 million pounds of live pork (29,353 animals) shipped to slaughter per year; 105,000 cu. ft. of scrubbed methane per day; and fertilizer. Total effluent is less than 200 gpm of agricultural quality-water with full odor control. The methane production rate made possible with geothermal direct heat is equivalent to at least 400 kw continuous. Sale of the methane on a co-generation basis is being discussed with the utility company. The use of geothermal direct heat energy in the complex displaces nearly 350,000 gallons of fuel oil per year. Generation of the biogas displaces an additional 300,000 gallons of fuel oil per year.

  7. Clone libraries and single cell genome amplification reveal extended diversity of uncultivated magnetotactic bacteria from marine and freshwater environments.

    Science.gov (United States)

    Kolinko, Sebastian; Wanner, Gerhard; Katzmann, Emanuel; Kiemer, Felizitas; Fuchs, Bernhard M; Schüler, Dirk

    2013-05-01

    Magnetotactic bacteria (MTB), which orient along the earth's magnetic field using magnetosomes, are ubiquitous and abundant in marine and freshwater environments. Previous phylogenetic analysis of diverse MTB has been limited to few cultured species and the most abundant and conspicuous members of natural populations, which were assigned to various lineages of the Proteobacteria, the Nitrospirae phylum as well as the candidate division OP3. However, their known phylogenetic diversity still not matches the large morphological and ultrastructural variability of uncultured MTB found in environmental communities. Here, we used analysis of 16S rRNA gene clone libraries in combination with microsorting and whole-genome amplification to systematically address the entire diversity of uncultured MTB from two different habitats. This approach revealed extensive and novel diversity of MTB within the freshwater and marine sediment samples. In total, single-cell analysis identified eight different phylotypes, which were only partly represented in the clone libraries, and which could be unambiguously assigned to their respective morphotypes. Identified MTB belonged to the Alphaproteobacteria (seven species) and the Nitrospirae phylum (two species). End-sequencing of a small insert library created from WGA-derived DNA of a novel conspicuous magnetotactic vibrio identified genes with highest similarity to two cultivated MTB as well as to other phylogenetic groups. In conclusion, the combination of metagenomic cloning and single cell sorting represents a powerful approach to recover maximum bacterial diversity including low-abundant magnetotactic phylotypes from environmental samples and also provides access to genomic analysis of uncultivated MTB. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. Taurolidine antiadhesive properties on interaction with E. coli; its transformation in biological environment and interaction with bacteria cell wall.

    Directory of Open Access Journals (Sweden)

    Francesco Caruso

    Full Text Available The taurine amino-acid derivative, taurolidine, bis-(1,1-dioxoperhydro-1,2,4-thiabiazinyl-4methane, shows broad antibacterial action against gram-positive and gram-negative bacteria, mycobacteria and some clinically relevant fungi. It inhibits, in vitro, the adherence of Escherichia coli and Staphylococcus aureus to human epithelial and fibroblast cells. Taurolidine is unstable in aqueous solution and breaks down into derivatives which are thought to be responsible for the biological activity. To understand the taurolidine antibacterial mechanism of action, we provide the experimental single crystal X-ray diffraction results together with theoretical methods to characterize the hydrolysis/decomposition reactions of taurolidine. The crystal structure features two independent molecules linked through intermolecular H-bonds with one of them somewhat positively charged. Taurolidine in a biological environment exists in equilibrium with taurultam derivatives and this is described theoretically as a 2-step process without an energy barrier: formation of cationic taurolidine followed by a nucleophilic attack of O(hydroxyl on the exocyclic C(methylene. A concerted mechanism describes the further hydrolysis of the taurolidine derivative methylol-taurultam. The interaction of methylol-taurultam with the diaminopimelic NH(2 group in the E. coli bacteria cell wall (peptidoglycan has a negative DeltaG value (-38.2 kcal/mol but a high energy barrier (45.8 kcal/mol suggesting no reactivity. On the contrary, taurolidine docking into E. coli fimbriae protein, responsible for bacteria adhesion to the bladder epithelium, shows it has higher affinity than mannose (the natural substrate, whereas methylol-taurultam and taurultam are less tightly bound. Since taurolidine is readily available because it is administered in high doses after peritonitis surgery, it may successfully compete with mannose explaining its effectiveness against bacterial infections at

  9. Taurolidine antiadhesive properties on interaction with E. coli; its transformation in biological environment and interaction with bacteria cell wall.

    Science.gov (United States)

    Caruso, Francesco; Darnowski, James W; Opazo, Cristian; Goldberg, Alexander; Kishore, Nina; Agoston, Elin S; Rossi, Miriam

    2010-01-28

    The taurine amino-acid derivative, taurolidine, bis-(1,1-dioxoperhydro-1,2,4-thiabiazinyl-4)methane, shows broad antibacterial action against gram-positive and gram-negative bacteria, mycobacteria and some clinically relevant fungi. It inhibits, in vitro, the adherence of Escherichia coli and Staphylococcus aureus to human epithelial and fibroblast cells. Taurolidine is unstable in aqueous solution and breaks down into derivatives which are thought to be responsible for the biological activity. To understand the taurolidine antibacterial mechanism of action, we provide the experimental single crystal X-ray diffraction results together with theoretical methods to characterize the hydrolysis/decomposition reactions of taurolidine. The crystal structure features two independent molecules linked through intermolecular H-bonds with one of them somewhat positively charged. Taurolidine in a biological environment exists in equilibrium with taurultam derivatives and this is described theoretically as a 2-step process without an energy barrier: formation of cationic taurolidine followed by a nucleophilic attack of O(hydroxyl) on the exocyclic C(methylene). A concerted mechanism describes the further hydrolysis of the taurolidine derivative methylol-taurultam. The interaction of methylol-taurultam with the diaminopimelic NH(2) group in the E. coli bacteria cell wall (peptidoglycan) has a negative DeltaG value (-38.2 kcal/mol) but a high energy barrier (45.8 kcal/mol) suggesting no reactivity. On the contrary, taurolidine docking into E. coli fimbriae protein, responsible for bacteria adhesion to the bladder epithelium, shows it has higher affinity than mannose (the natural substrate), whereas methylol-taurultam and taurultam are less tightly bound. Since taurolidine is readily available because it is administered in high doses after peritonitis surgery, it may successfully compete with mannose explaining its effectiveness against bacterial infections at laparoscopic lesions.

  10. Economics of Hot Water Dipping

    OpenAIRE

    P., Maxin; K., Klopp

    2004-01-01

    Hot water dipping is an appropriate method to protect apples against spoilage caused by gloeosporium rot. Tests on the varieties Topaz and Ingrid Marie at the OVB Jork (Germany) have demonstrated an effective reduction of spoilage from between 80% and 92% in charges by an infection rate of 40%. The result of an intensive R&D process between 2002 and 2003 is the development of a praxis-tested big box (300 kg) dipping station. With the first Bio Dipping systems now on the mark...

  11. Hot moons and cool stars

    Directory of Open Access Journals (Sweden)

    Heller René

    2013-04-01

    Full Text Available The exquisite photometric precision of the Kepler space telescope now puts the detection of extrasolar moons at the horizon. Here, we firstly review observational and analytical techniques that have recently been proposed to find exomoons. Secondly, we discuss the prospects of characterizing potentially habitable extrasolar satellites. With moons being much more numerous than planets in the solar system and with most exoplanets found in the stellar habitable zone being gas giants, habitable moons could be as abundant as habitable planets. However, satellites orbiting planets in the habitable zones of cool stars will encounter strong tidal heating and likely appear as hot moons.

  12. Hot Flow Anomalies at Venus

    Science.gov (United States)

    Collinson, G. A.; Sibeck, David Gary; Boardsen, Scott A.; Moore, Tom; Barabash, S.; Masters, A.; Shane, N.; Slavin, J.A.; Coates, A.J.; Zhang, T. L.; hide

    2012-01-01

    We present a multi-instrument study of a hot flow anomaly (HFA) observed by the Venus Express spacecraft in the Venusian foreshock, on 22 March 2008, incorporating both Venus Express Magnetometer and Analyzer of Space Plasmas and Energetic Atoms (ASPERA) plasma observations. Centered on an interplanetary magnetic field discontinuity with inward convective motional electric fields on both sides, with a decreased core field strength, ion observations consistent with a flow deflection, and bounded by compressive heated edges, the properties of this event are consistent with those of HFAs observed at other planets within the solar system.

  13. POLI: Polarised hot neutron diffractometer

    Directory of Open Access Journals (Sweden)

    Vladimir Hutanu

    2015-08-01

    Full Text Available POLI, which is operated by the Institute of Crystallography, RWTH Aachen University in cooperation with JCNS, Forschungszentrum Jülich, is a versatile two axes single crystal diffractometer with broad field of applications. Mostly dedicated to the investigation of magnetic structures in single crystals using neutron spin polarisation, POLI is also used for classical structural investigations under extreme conditions. High intensity hot neutrons flux makes it attractive also for the other applications like study of parity violations phenomena in nuclear physics or BNCT (boron neutron-capture therapy in medicine.

  14. Hot demonstration of proposed commercial nuclide removal technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This task covers the development and operation of an experimental test unit located in a Building 4501 hot cell within Building 4501 at Oak Ridge National Laboratory (ORNL). This equipment is designed to test radionuclides removal technologies under continuous operatoin on actual ORNL Melton Valley Storage Tank (MVST) supernatant, Savannah River high-level waste supernatant, and Hanford supernatant. The latter two may be simulated by adding the appropriate chemicals and/or nuclides to the MVST supernatant.

  15. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  16. 'Hot' cognition in major depressive disorder

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W; Carvalho, Andre F

    2014-01-01

    Major depressive disorder (MDD) is associated with significant cognitive dysfunction in both 'hot' (i.e. emotion-laden) and 'cold' (non-emotional) domains. Here we review evidence pertaining to 'hot' cognitive changes in MDD. This systematic review searched the PubMed and PsycInfo computerized......-limbic network with hyper-activity in limbic and ventral prefrontal regions paired with hypo-activity of dorsal prefrontal regions subserve these abnormalities. A cross-talk of 'hot' and 'cold' cognition disturbances in MDD occurs. Disturbances in 'hot cognition' may also contribute to the perpetuation...

  17. Development of scientific and technological basis for the fabrication of thin film solar cells on the basis of a-Si:H and {mu}c-Si:H using the 'hot-wire' deposition technique. Final report; Entwicklung wissenschaftlicher und technischer Grundlagen fuer die Herstellung von Duennschichtsolarzellen auf der Basis des a-Si:H und {mu}c-Si:H mit der 'Hot-Wire'-Depositionstechnik. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, B.

    2002-01-22

    Two new deposition systems were realized enabling the entire and respectively, large area deposition of a-Si:H based solar cells using the so called 'hot-wire' (HW) CVD. The deposition conditions for appropriate n- and p-doped a-Si:H and {mu}c-Si:H layers have been developed. For the first time in the world a-Si:H based pin solar cells were entirely deposited by the HWCVD method. A maximum initial conversion efficiency of {eta}{sub initial}=8.9% was obtained. After the development of a suitable p/n-tunnel/recombination junction pin-pin tandem structures with a-Si:H absorbers could be entirely fabricated by the HWCVD for the first time in the world, too. A conversion efficiency of {eta}=7% was measured for the tandem cell, after some structural degradation took place. In general, the stability of the HWCVD solar cells is not satisfactory, what could be attributed to a structural instability of the HWCVD-p-layers. For the first time we have deposited nip solar cells on stainless steel substrates entirely by HWCVD ({eta}{sub initial}>6%). The incorporation of {mu}c-Si:H absorber layers by HWCVD or ECWR-PECVD into pin solar cells was not successfull until now. Large area deposition of a-Si:H films has been performed in a simple vacuum vessel. Under consideration of appropriate filament and gas supply geometry as well as simulation calculations a good electronic quality and a film thickness uniformity of {delta}d={+-}2.5% of the material was obtained. i-layers for small area solar cells on an area of 20 x 20 cm{sup 2} have been deposited which could be completed to solar cells with very uniform conversion efficiencies of {eta}{sub initial} = 6,1{+-}0.2%. This result represents a proof of concept for the large area deposition of a-Si:H based solar cells using the HWCVD. Also for the first time the HWCVD was used for the deposition of emitter layers on c-Si-wafers to realize hetero solar cells. Hetero solar cells with amorphous, microcrystalline and epitaxial n

  18. HotSpot Wizard: a web server for identification of hot spots in protein engineering

    National Research Council Canada - National Science Library

    Pavelka, Antonin; Chovancova, Eva; Damborsky, Jiri

    2009-01-01

    HotSpot Wizard is a web server for automatic identification of 'hot spots' for engineering of substrate specificity, activity or enantioselectivity of enzymes and for annotation of protein structures...

  19. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests

  20. Hot Carrier-Based Near-Field Thermophotovoltaic Energy Conversion.

    Science.gov (United States)

    St-Gelais, Raphael; Bhatt, Gaurang Ravindra; Zhu, Linxiao; Fan, Shanhui; Lipson, Michal

    2017-03-28

    Near-field thermophotovoltaics (NFTPV) is a promising approach for direct conversion of heat to electrical power. This technology relies on the drastic enhancement of radiative heat transfer (compared to conventional blackbody radiation) that occurs when objects at different temperatures are brought to deep subwavelength distances (typically conversion of heat to electricity with a greater efficiency than using current solid-state technologies (e.g., thermoelectric generators). One of the main challenges in the development of this technology, however, is its incompatibility with conventional silicon PV cells. Thermal radiation is weak at frequencies larger than the ∼1.1 eV bandgap of silicon, such that PV cells with lower excitation energies (typically 0.4-0.6 eV) are required for NFTPV. Using low bandgap III-V semiconductors to circumvent this limitation, as proposed in most theoretical works, is challenging and therefore has never been achieved experimentally. In this work, we show that hot carrier PV cells based on Schottky junctions between silicon and metallic films could provide an attractive solution for achieving high efficiency NFTPV electricity generation. Hot carrier science is currently an important field of research and several approaches are investigated for increasing the quantum efficiency (QE) of hot carrier generation beyond conventional Fowler model predictions. If the Fowler limit can indeed be overcome, we show that hot carrier-based NFTPV systems-after optimization of their thermal radiation spectrum-could allow electricity generation with up to 10-30% conversion efficiencies and 10-500 W/cm 2 generated power densities (at 900-1500 K temperatures). We also discuss how the unique properties of thermal radiation in the extreme near-field are especially well suited for investigating recently proposed approaches for high QE hot carrier junctions. We therefore expect our work to be of interest for the field of hot carrier science and-by relying

  1. Growth factors in multiple myeloma: a comprehensive analysis of their expression in tumor cells and bone marrow environment using Affymetrix microarrays

    Directory of Open Access Journals (Sweden)

    Meißner Tobias

    2010-05-01

    Full Text Available Abstract Background Multiple myeloma (MM is characterized by a strong dependence of the tumor cells on their microenvironment, which produces growth factors supporting survival and proliferation of myeloma cells (MMC. In the past few years, many myeloma growth factors (MGF have been described in the literature. However, their relative importance and the nature of the cells producing MGF remain unidentified for many of them. Methods We have analysed the expression of 51 MGF and 36 MGF receptors (MGFR using Affymetrix microarrays throughout normal plasma cell differentiation, in MMC and in cells from the bone marrow (BM microenvironment (CD14, CD3, polymorphonuclear neutrophils, stromal cells and osteoclasts. Results 4/51 MGF and 9/36 MGF-receptors genes were significantly overexpressed in plasmablasts (PPC and BM plasma cell (BMPC compared to B cells whereas 11 MGF and 11 MGFR genes were overexpressed in BMPC compared to PPC. 3 MGF genes (AREG, NRG3, Wnt5A and none of the receptors were significantly overexpressed in MMC versus BMPC. Furthermore, 3/51 MGF genes were overexpressed in MMC compared to the the BM microenvironment whereas 22/51 MGF genes were overexpressed in one environment subpopulation compared to MMC. Conclusions Two major messages arise from this analysis 1 The majority of MGF genes is expressed by the bone marrow environment. 2 Several MGF and their receptors are overexpressed throughout normal plasma cell differentiation. This study provides an extensive and comparative analysis of MGF expression in plasma cell differentiation and in MM and gives new insights in the understanding of intercellular communication signals in MM.

  2. Hot Jupiters around young stars

    Science.gov (United States)

    Yu, L. F.; Donati, J.-F.

    2017-12-01

    This conference paper presents the results of the MaTYSSE (Magnetic Topologies of Young Stars and the Survival of massive close-in Exoplanets) observation programme, regarding the search for giant exoplanets around weak-line T Tauri stars (wTTS), as of early 2017. The discoveries of two hot Jupiters (hJs), around V830 Tau and TAP 26, sun-like stars of respectively ˜2 Myr and ˜17 Myr, are summarized here. Both exoplanets seem to have undergone type-II migration (planet-disc interaction leading the orbit to narrow around the host) based on their low orbital eccentricity. The methods which were used are given more focus in the paper Stellar activity filtering methods for the detection of exoplanets in the present book.

  3. Hot spots of mutualistic networks.

    Science.gov (United States)

    Gilarranz, Luis J; Sabatino, Malena; Aizen, Marcelo A; Bascompte, Jordi

    2015-03-01

    Incorporating interactions into a biogeographical framework may serve to understand how interactions and the services they provide are distributed in space. We begin by simulating the spatiotemporal dynamics of realistic mutualistic networks inhabiting spatial networks of habitat patches. We proceed by comparing the predicted patterns with the empirical results of a set of pollination networks in isolated hills of the Argentinian Pampas. We first find that one needs to sample up to five times as much area to record interactions as would be needed to sample the same proportion of species. Secondly, we find that peripheral patches have fewer interactions and harbour less nested networks - therefore potentially less resilient communities - compared to central patches. Our results highlight the important role played by the structure of dispersal routes on the spatial distribution of community patterns. This may help to understand the formation of biodiversity hot spots. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  4. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  5. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-02-26

    This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes a description of a device developed to harden a filter cake on a filter element so that the element and cake can subsequently be encapsulated in epoxy and studied in detail. This report also reviews the status of the HGCU data base of ash and char characteristics. Task 1 plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF), encapsulation of an intact filter cake from the PSDF, and completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter consisted of hoop tensile and axial compressive stress-strain responses of McDermott ceramic composite and hoop tensile testing of Techniweave candle filters as-manufactured and after exposure to the gasification environment.

  6. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  7. Sickle Cell Crisis (For Teens)

    Science.gov (United States)

    ... Plan Hot Topics Flu Facts Arrhythmias Abuse Sickle Cell Crisis (Pain Crisis) KidsHealth > For Teens > Sickle Cell ... drepanocíticas (Crisis de dolor) What Is a Sickle Cell Crisis? Sickle cell disease changes the shape of ...

  8. 'Hot' cognition in major depressive disorder

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W; Carvalho, Andre F

    2014-01-01

    Major depressive disorder (MDD) is associated with significant cognitive dysfunction in both 'hot' (i.e. emotion-laden) and 'cold' (non-emotional) domains. Here we review evidence pertaining to 'hot' cognitive changes in MDD. This systematic review searched the PubMed and PsycInfo computerized...

  9. Hot Blade Cuttings for the Building Industries

    DEFF Research Database (Denmark)

    Brander, David; Bærentzen, Jakob Andreas; Evgrafov, Anton

    2016-01-01

    . The project aims to reduce the amount of manual labour as well as production time by applying robots to cut expanded polystyrene (EPS) moulds for the concrete to form doubly curved surfaces. The scheme is based upon the so-called Hot Wire or Hot Blade technology where the surfaces are essentially swept out...

  10. Variational Theory of Hot Dense Matter

    Science.gov (United States)

    Mukherjee, Abhishek

    2009-01-01

    We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

  11. DEMONSTRATING INTEGRATED PEST MANAGEMENT OF HOT PEPPERS

    Science.gov (United States)

    We studied the effects of organic and synthetic chemical fertilizers on crop growth, yield and associated insect pests for two varieties of hot pepper, Capsicum chinense Jacquin (Solanaceae): “Scotch Bonnet” and “Caribbean Red” in north Florida. Hot peppers were grown under three treatments: poultr...

  12. Solar Energy for Space Heating & Hot Water.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  13. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  14. Hot Tub Rash (Pseudomonas Dermatitis/Folliculitis)

    Science.gov (United States)

    ... name=”commit” type=”submit” value=”Submit” /> Healthy Water Home Rashes Language: English (US) Español (Spanish) Recommend on ... scrubbing and cleaning? Replacement of the hot tub water filter according to manufacturer’s recommendations? Replacement of hot tub ...

  15. Hot Spot Removal System: System description

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

  16. The Hot Hand Belief and Framing Effects

    Science.gov (United States)

    MacMahon, Clare; Köppen, Jörn; Raab, Markus

    2014-01-01

    Purpose: Recent evidence of the hot hand in sport--where success breeds success in a positive recency of successful shots, for instance--indicates that this pattern does not actually exist. Yet the belief persists. We used 2 studies to explore the effects of framing on the hot hand belief in sport. We looked at the effect of sport experience and…

  17. Hot-dry-rock feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    1981-08-01

    The hot-dry-rock project tasks are covered as follows: hot-dry-rock reservoir; generation facilities; water resources; transmission requirements; environmental issues; government and community institutional factors; leasing, ownership and management of facilities; regulations, permits, and laws; and financial considerations. (MHR)

  18. Desulphurization of hot metal and nickel pig iron using waste materials from the aluminum industry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.D.; McLean, A. [Toronto Univ., ON (Canada). Dept. of Materials Science and Engineering; Hasegawa, M.; Iwase, M. [Kyoto Univ., Kyoto (Japan). Dept. of Energy Science and Technology, Ferrous Metallurgy Research Group; Ren, M.L.; Zhang, D.F. [China Aluminum Co. Ltd., Shandong (China)

    2009-07-01

    The aluminium and steel industries are both energy-intensive and have significant impacts on the environment. The desulphurization of hot metal and nickel pig iron using waste materials from the aluminium industry was evaluated in this study. A simple processing technique using dross and white mud was developed to desulphurize hot metals. Waste materials with a high oxide content were combined with an aluminium instant reduction method and then used for hot metal desulphurization. The presence of nickel in the hot metals showed a negative effect on the desulphurization process as the nickel reduced carbon solubility in an iron-based metal solution. It was concluded that the use of waste slags and solids residuals from the aluminium industry within the steel industry will reduce the disposal of waste and provide significant economic benefits to both industries. 6 refs., 2 tabs., 12 figs.

  19. Hot corrosion of TD nickel and TD nickel chromium in a high velocity gas stream.

    Science.gov (United States)

    Sanders, W. A.; Probst, H. B.

    1971-01-01

    Results of cyclical tests of TD nickel (2% thoria-dispersed nickel) and TD nickel chromium (2% thoria-dispersed nickel-20% chromium alloy) 1.5 mm (60 mil) sheet specimens for susceptibility to hot corrosion in a Mach 0.5 gas stream of Jet A-1 fuel combustion products containing 2 ppm sea salt. Tests as long as 500 one-hour cycles between room temperature and specimen hot zone temperatures of 899 C (1650 F), 982 C (1800 F), and 1149 C (2100 F) were performed. Evidence of hot corrosion was found for both materials in the 899 C (1650 F) and 982 C (1800 F) tests, but not at 1149 C (2100 F). It was concluded that because of high metal thickness losses neither alloy in sheet form is suitable for long-time engine application in a <