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Sample records for cells experimental study

  1. Analytical modelling and experimental studies of SIS tunnel solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheknane, Ali [Laboratoire de Valorisation des Energies Renouvelables et Environnements Agressifs, Universite Amar Telidji de Laghouat, BP 37G route de Ghardaia, Laghouat (03000) Algerie (Algeria)], E-mail: cheknanali@yahoo.com

    2009-06-07

    This paper presents an experimental and computational study of semiconductor-insulator-semiconductor (SIS) tunnel solar cells. A transparent and conductive film of thallium trioxide Tl{sub 2}O{sub 3} has been deposited by anodic oxidation onto an n-Si(1 0 0) face to realize the SIS tunnel solar cells based on Si/SiO{sub x}/Tl{sub 2}O{sub 3}. An efficiency of 8.77% has been obtained under an incident power density of 33 mW cm{sup -2} illumination condition. A PSPICE model is implemented. The calculated results show that the theoretical values are in good agreement with experimental data. Moreover, the simulation clearly demonstrates that the performance of the tested device can be significantly improved.

  2. Experimental and numerical studies of micro PEM fuel cell

    Institute of Scientific and Technical Information of China (English)

    Rong-Gui Peng; Chen-Chung Chung; Chiun-Hsun Chen

    2011-01-01

    A single micro proton exchange membrane fuel cell (PEMFC) has been produced using Micro-electromechanical systems (MEMS) technology with the active area of 2.5 cm2 and channel depth of about 500μm.A theoretical analysis is performed in this study for a novel MEMS-based design of a micro PEMFC.The model consists of the conservation equations of mass,momentum,species and electric current in a fully integrated finite-volume solver using the CFD-ACE+ commercial code.The polarization curves of simulation are well correlated with experimental data.Three-dimensional simulations are carried out to treat prediction and analysis of micro PEMFC temperature,current density and water distributions in two different fuel flow rates (15 cm3/min and 40 cm3/min).Simulation results show that temperature distribution within the micro PEMFC is affected by water distribution in the membrane and indicate that low and uniform temperature distribution in the membrane at low fuel flow rates leads to increased membrane water distribution and obtains superior micro PEMFC current density distribution under 0.4 V operating voltage.Model predictions are well within those known for experimentalmechanism phenomena.

  3. Experimental study of bioartificial liver with cultured human liver cells

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    AIM To establish an extracorporeal bioartificial liver support system (EBLSS) using cultured human liver cells and to study its support effect for fulminant hepatic failure (FHF).METHODS The liver support experiment of EBLSS consisting of aggregates cultured human liver cells, hollow fiber bioreactor, and circulation unit was carried out in dizhepatic dogs.RESULTS The viability of isolated hepatocytes and nonparenchymal liver cells reached 96%. These cells were successfully cultured as multicellular spheroids with synthetic technique. The typical morphological appearance was retained up to the end of the artificial liver experiment. Compared with the control dogs treated with EBLSS without liver cells, the survival time of artificial liver support dogs was significantly prolonged. The changes of blood pressure, heart rate and ECG were slow. Both serum ammonia and lactate levels were significantly lowered at the 3rd h and 5th h. In addition, a good viability of human liver cells was noted after 5 h experiment.CONCLUSION EBLSS playing a metabolic role of cultured human hepatocytes, is capable of compensating the function of the liver, and could provide effective artificial liver support and therapy for patients with FHF.

  4. Theoretical and Experimental Study of Plasmonic Polymer Solar Cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Adam, Jost; Madsen, Morten

    The organic bulk hetero-junction solar cell has remarkable advantages such as low cost, mechanical flexibility and simple process techniques. Recently, low-band gap photoactive materials have obtained a significant attention due to their potential to absorb a wider range of the solar spectrum...... to attain higher power conversion efficiencies. Many low-band gap photoactive materials, however, still show a relatively low external quantum efficiency of less than 60% [1]. One possible approach to improve the device performance is to increase the light absorption in the active layer. This may, amongst...... other approaches, be achieved by using nano- or micro-structures that trap light at specific wavelengths [2], or by using the localized surface plasmon resonance effect of metal nanoparticles in the devices. In this work, we theoretically studied planar polymer solar cell based on finite-difference time...

  5. [Experimental study on electrical impedance properties of human hepatoma cells].

    Science.gov (United States)

    Fang, Yun; Tang, Zhiyuan; Zhang, Qian; Zhao, Xin; Ma, Qing

    2014-10-01

    The AC impedance of human hepatoma SMMC-7721 cells were measured in our laboratory by Agilent 4294A impedance analyzer in the frequency range of 0.01-100 MHz. And then the effect of hematocrit on electrical impedance characteristics of hepatoma cells was observed by electrical impedance spectroscopy, Bode diagram, Nyquist diagram and Nichols diagram. The results showed that firstly, there is a frequency dependence, i.e., the increment of real part and the imaginary part of complex electrical impedance (δZ', δZ"), the increment of the amplitude modulus of complex electrical impedance (δ[Z *]) and phase angle (δθ) were all changed with the increasing frequency. Secondly, it showed cell volume fraction (CVF) dependence, i. e. , the increment of low-frequency limit (δZ'0, δ[Z*] 0), peak (δZ"(p), δθ(p)), area and radius (Nyquist diagram, Nichols diagram) were all increased along with the electric field frequency. Thirdly, there was the presence of two characteristic frequencies: the first characteristic frequency (f(c1)) and the second characteristic frequency (f(c2)), which were originated respectively in the polarization effects of two interfaces that the cell membrane and extracellular fluid, cell membrane and cytoplasm. A conclusion can be drawn that the electrical impedance spectroscopy is able to be used to observe the electrical characteristics of human hepatoma cells, and therefore this method can be used to investigate the electrophysiological mechanisms of liver cancer cells, and provide research tools and observation parameters, and it also has important theoretical value and potential applications for screening anticancer drugs. PMID:25764724

  6. Experimental Study on Apoptosis in Leukemia Cells Induced by Econazole

    Institute of Scientific and Technical Information of China (English)

    LIUFang; ZOUPing; ZHANGMin; WUYaohui; XIAOJuan

    2005-01-01

    Objective: To investigate apoptosis in monse leukemia cell (WEHI-3) induced by Econazole and its mechanisin. Methods: Apoptosis induced by Econazole was examined by flow cytometry. Free calcium ([Ca2+]i) was determined by Fura-2 fluorescein load technique. The protein was isolated from endoplasinic reticulum of WEHI-3 cells, and then the expression of caspase-12 and caspase-7 was detected by Western blot. Results: WEHI-3 cells exhibited typical change of apoptosis when they were treated by Econazole.[Ca2+]i was significantly higher in Econazole-treated group t han in control group. The expression of caspase-12 and caspase-7 was increased with the increase of Econazole concentration. Conclusion: Caspase-12 may play a key role in WEHI-3 apoptosis induced by Econazole.

  7. The Preliminary Experimental Study of Induced Differentiation of Embryonic Stem Cells into Corneal Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Ling Yu; Jian Ge; Zhichong Wang; Bing Huang; Keming Yu; Chongde Long; Xigu Chen

    2001-01-01

    Purpose:To study preliminarily induced differentiation of embryonic stem cells intocorneal epithelial cells in vitro.Methods: Murine embryonic stem cells were co-cultured with Rabbit limbal cornealepithelial cells in Transwell system to induce differentiation. Mophological andimmunohistochemical examination were implemented.Results: The induced cells from embryonic stem cells have an epithelial appearance.The cells formed a network and were confluent into film gradually after beingco-cultured with rabbit limbal corneal epithelial cells for 24 ~ 96 hours. The cells rangedmosaic structure and localized together with clear rim. Most of the cells showedpolygonal appearance. Transmission electron microscope showed lots of microvilli on thesurface of induced cells and tight junctions between them. These epithelial-like cellsexpressed the corneal epithelial cell specific marker cytokeratin3/cytokeratinl2.Conclusion: The potential mechanism of the differentiation of murine embryonic stemcells into corneal epithelial cells induced by limbal corneal epithelial cell-derivedinducing activity is to be further verified.

  8. Experimental study of current distribution in proton exchange membrane fuel cell : experimental setup and flow arrangement effect

    Energy Technology Data Exchange (ETDEWEB)

    Alaefour, I.; Jiao, K.; Al Shakhshir, S.; Li, X. [Waterloo Univ., ON (Canada). Dept. of Mechanical and Mechatronics Engineering; Karimi, G. [Shiraz Univ., Shiraz (Iran, Islamic Republic of)

    2010-07-01

    The proton exchange membrane fuel cell (PEMFC) is among the most promising zero-emission power sources for transportation applications. Many experimental and numerical studies have been devoted to understanding the current distribution in PEMFCs because it is essential to improve their reliability and durability. In this study, a special fuel cell with three parallel serpentine flow channels was designed and fabricated in-house in order to conduct in-situ mapping of the local current distribution over the electrode surface. An array of segmented current collectors was distributed on one of the bipolar plates. The local current density distribution along the serpentine flow channels was investigated for various flow configurations, including co-flow, cross-flow, and counter-flow arrangements. All the experimental results for the local density distribution were conducted under identical operating conditions. The current distribution along the flow channels with different vertical-horizontal cell was also examined. The study showed that the counter flow arrangement for the anode and cathode stream yields the most uniform distribution for the current density, whereas, co-flow arrangement results in a considerable variations in the current density from the cathode stream inlet to the cathode exit. Cell orientation can also influence the cell performance and the current distribution considerably. 24 refs., 2 tabs., 9 figs.

  9. Experimental and Computer Modelling Studies of Metastability of Amorphous Silicon Based Solar Cells

    OpenAIRE

    Munyeme, Geoffrey

    2003-01-01

    We present a combination of experimental and computer modelling studies of the light induced degradation in the performance of amorphous silicon based single junction solar cells. Of particular interest in this study is the degradation kinetics of different types of amorphous silicon single junction solar cells and the role of dangling bond states in mediating or driving the degradation mechanism. The approach taken in this study has enabled has to examine how light induced degradation is aff...

  10. Experimental and Computer Modelling Studies of Metastability of Amorphous Silicon Based Solar Cells

    NARCIS (Netherlands)

    Munyeme, Geoffrey

    2003-01-01

    We present a combination of experimental and computer modelling studies of the light induced degradation in the performance of amorphous silicon based single junction solar cells. Of particular interest in this study is the degradation kinetics of different types of amorphous silicon single junction

  11. A Well-Controlled Experimental System to Study Interactions of Cytotoxic T Lymphocytes with Tumor Cells.

    Science.gov (United States)

    Neubert, Natalie J; Soneson, Charlotte; Barras, David; Baumgaertner, Petra; Rimoldi, Donata; Delorenzi, Mauro; Fuertes Marraco, Silvia A; Speiser, Daniel E

    2016-01-01

    While T cell-based immunotherapies are steadily improving, there are still many patients who progress, despite T cell-infiltrated tumors. Emerging evidence suggests that T cells themselves may provoke immune escape of cancer cells. Here, we describe a well-controlled co-culture system for studying the dynamic T cell - cancer cell interplay, using human melanoma as a model. We explain starting material, controls, and culture parameters to establish reproducible and comparable cultures with highly heterogeneous tumor cells. Low passage melanoma cell lines and melanoma-specific CD8+ T cell clones generated from patient blood were cultured together for up to 3 days. Living melanoma cells were isolated from the co-culture system by fluorescence-activated cell sorting. We demonstrate that the characterization of isolated melanoma cells is feasible using flow cytometry for protein expression analysis as well as an Agilent whole human genome microarray and the NanoString technology for differential gene expression analysis. In addition, we identify five genes (ALG12, GUSB, RPLP0, KRBA2, and ADAT2) that are stably expressed in melanoma cells independent of the presence of T cells or the T cell-derived cytokines IFNγ and TNFα. These genes are essential for correct normalization of gene expression data by NanoString. Further to the characterization of melanoma cells after exposure to CTLs, this experimental system might be suitable to answer a series of questions, including how the affinity of CTLs for their target antigen influences the melanoma cell response and whether CTL-induced gene expression changes in melanoma cells are reversible. Taken together, our human T cell - melanoma cell culture system is well suited to characterize immune-related mechanisms in cancer cells.

  12. Intercellular ultrafast Ca(2+) wave in vascular smooth muscle cells: numerical and experimental study.

    Science.gov (United States)

    Quijano, J C; Raynaud, F; Nguyen, D; Piacentini, N; Meister, J J

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca(2+) waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca(2+) wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca(2+) wave and it was suggested to be the result of the interplay between membrane potential and Ca(2+) dynamics which depended on influx of extracellular Ca(2+), cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca(2+) wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca(2+) wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca(2+) wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca(2+) waves in smooth muscle cells. PMID:27507785

  13. Intercellular ultrafast Ca2+ wave in vascular smooth muscle cells: numerical and experimental study

    Science.gov (United States)

    Quijano, J. C.; Raynaud, F.; Nguyen, D.; Piacentini, N.; Meister, J. J.

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca2+ waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca2+ wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca2+ wave and it was suggested to be the result of the interplay between membrane potential and Ca2+ dynamics which depended on influx of extracellular Ca2+, cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca2+ wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca2+ wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca2+ wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca2+ waves in smooth muscle cells. PMID:27507785

  14. Experimental studies

    International Nuclear Information System (INIS)

    Spectral fluence measurements in an adult phantom are reported. A NaI(Tl) probe was used in various locations within the phantom and pulse-height spectra were obtained for seven beam configurations and three generating potentials. Some typical spectra results are presented. A comparison of calculated dose to experimental measurements is presented

  15. Theoretical and experimental study of electroporation of red blood cells using MEMS technology

    KAUST Repository

    Deng, Peigang

    2010-01-01

    A theoretical and experimental study of electroporation (EP) of red blood cells (RBCs) was presented in this paper. With additional strain energy, an energy-based model of an electropore induced on a RBC\\'s membrane at different electric fields was proposed to predict the critical EP electric field strength. In addition, EP experiments with red blood cells at single-cell level was carried out on a micro EP chip. The measured critical EP electric field strengths are in agreement with the numerical predictions. ©2010 IEEE.

  16. Experimental Study and Comparison of Various Designs of Gas Flow Fields to PEM Fuel Cells and Cell Stack Performance

    OpenAIRE

    PeiwenLi

    2014-01-01

    In this study, a significant number of experimental tests to proton exchange membrane (PEM) fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells have an effective membrane area of 23.5 cm2. The results showed that the serpentine flow channel design is still ...

  17. Experimental and numerical study of proton exchange membrane fuel cell with spiral flow channels

    International Nuclear Information System (INIS)

    Highlights: ► Numerical and experimental study of the fuel cell with spiral channels is performed. ► Secondary vortices in cross section of the spiral channels are found. ► Enhancement in the performance of the fuel cell by the secondary vortices is discussed. ► The spiral channels also lead to a reduction in the pressure drop of the gas flow. -- Abstract: Numerical simulation of the performance of a proton exchange membrane fuel cell (PEMFC) with spiral channels is performed in this study. Experiments are also conducted to verify the numerical predictions. The spiral channel pattern produces secondary vortices which lead to enhancement in heat and mass transfer in the curved channels and appreciably improves the performance of the fuel cell. In addition, the spiral channels may also lead to a reduction in the pressure drop of the gas flow through the fuel cell. When the sizes of the outlet channels are designed to be smaller than those of the inlet channels, water flooding in the catalyst layers can be further improved. In the present study, the spiral channel pattern consists of five inlet channels and five outlet channels. Radius and area of the active zone are 28.2 mm and 2500 mm2, respectively. A comparison between the spiral and the serpentine channels shows that the average current density with the former is higher than that with the latter by 11.9%. It is found that numerical predictions are in close agreement with the experimental results.

  18. Structural determinants of resveratrol for cell proliferation inhibition potency: experimental and docking studies of new analogs.

    Science.gov (United States)

    Mazué, Frédéric; Colin, Didier; Gobbo, Jessica; Wegner, Maria; Rescifina, Antonio; Spatafora, Carmela; Fasseur, Dominique; Delmas, Dominique; Meunier, Philippe; Tringali, Corrado; Latruffe, Norbert

    2010-07-01

    Resveratrol is the subject of intense research because of the abundance of this compound in the human diet and as one of the most valuable natural chemopreventive agents. Further advances require new resveratrol analogs be used to identify the structural determinants of resveratrol for the inhibition potency of cell proliferation by comparing experimental and docking studies. Therefore, we synthesized new trans/(E)- and cis/(Z)-resveratrol - analogs not reported to date - by modifying the hydroxylation pattern of resveratrol and a double bond geometry. We included them in a larger panel of 14 molecules, including (Z)-3,5,4'-trimethoxystilbene, the most powerful molecule that is used as reference. Using a docking model complementary to experimental studies on the proliferation inhibition of the human colorectal tumor SW480 cell line, we show that methylation is the determinant substitution in inhibition efficacy, but only in molecules bearing a Z configuration. Most of the synthetic methylated derivatives (E or Z) stop mitosis at the M phase and lead to polyploid cells, while (E)-resveratrol inhibits cells at the S phase. Docking studies show that almost all of the docked structures of (Z)-polymethoxy isomers, but not most of the (E)-polymethoxy isomers substantially overlap the docked structure of combretastatin A-4, taken as reference ligand at the colchicine-tubulin binding site. PMID:20395019

  19. Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

    OpenAIRE

    Yong-Song Chen; Sheng-Miao Lin; Boe-Shong Hong

    2013-01-01

    A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investig...

  20. Chemo-radionuclide therapy for thyroid cancer. Initial experimental study with cultured cells

    Energy Technology Data Exchange (ETDEWEB)

    Misaki, Takashi; Iwata, Masahiro; Iida, Yasuhiro; Kasagi, Kanji; Konishi, Junji [Kyoto Univ. (Japan). Graduate School of Medicine

    2002-09-01

    Radioiodine therapy has long been used for distant metastases of thyroid cancer. Although partially effective in most cases, it can render a complete cure only in a limited number of patients. One way to enhance its efficacy would be to combine it with antineoplastic agents. Here we describe an initial in vitro evaluation with 4 thyroid cancer cell lines. Cells were sparsely seeded in microtiter plates and allowed to grow for 2 days; then they were exposed to sublethal concentrations of cisplatin (CDDP), doxorubicin (Dox), or 5-fluorouracil (5-FU), followed by treatment with I-131 for 48 hr. Cell survival was measured with a commercial kit based on the colorimetry of succinate dehydrogenase activity. Chemotherapeutic drugs exerted similar concentration-dependent cytotoxic effects in all 4 cell lines. The doses necessary to reduce the surviving fraction to half of the control were about 3 {mu}g/ml for CDDP, 0.3 {mu}g/ml for Dox, and 3 {mu}g/ml for 5-FU (when used continuously for 48 hours). On the other hand, sensitivity to I-131 irradiation differed among the lines; same doses (7.4-14.8 MBq/ml) caused the greatest damage in FRO cells, a modest effect in NPA and WRO, and only minimal change in B-CPAP. The combined effect was most demonstrable in wells treated with Dox and radioiodine, whereas the addition of CDDP or 5-FU had marginal or insignificant merit, respectively. In FRO cells, half-lethal doses of the above mentioned CDDP, Dox, and 5-FU, when used together with 14.8 MBq/ml I-131, reduced cell survival to 54.5%, 29.4% and 33.4%, respectively, vs. 60.2% with radioiodine alone. In vitro, clinical concentrations of Dox can accelerate the killing of thyroid cancer cells by radioiodine. These favorable experimental results warrant future studies to evaluate whether this new bidisciplinary approach is clinically relevant and feasible. (author)

  1. Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Yong-Song Chen

    2013-12-01

    Full Text Available A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investigated at two different selected output voltages of the DC/DC converter in the battery line. The power sharing of each power source and efficiency are also analyzed and discussed. Experimental results show that the battery can compensate for the shortage of supplied power for the load demand during the start-up and acceleration. The lowest operating voltage of the fuel cell stack is limited by the regulated output voltage of the DC/DC converter. The major power loss in the hybrid power system is attributed to the diodes. The power train efficiency can be improved by lowering the ratio of forward voltage drop of the diode to the operating voltage of the fuel cell stack.

  2. An experimental platform for studying growth and invasiveness of tumor cells within teratomas derived from human embryonic stem cells

    OpenAIRE

    Tzukerman, Maty; Rosenberg, Tzur; Ravel, Yael; Reiter, Irena; Coleman, Raymond; Skorecki, Karl

    2003-01-01

    There is currently no available experimental system wherein human cancer cells can be grown in the context of a mixed population of normal differentiated human cells for testing biological aspects of cancer cell growth (e.g., tumor cell invasion and angiogenesis) or response to anti-cancer therapies. When implanted into immunocompromised mice, human embryonic stem cells develop teratomas containing complex structures comprising differentiated cell types representing the major germ line-derive...

  3. Experimental and Theoretical Studies of the Structures and Interactions of Vancomycin Antibiotics with Cell Wall Analogues

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhibo; Vorpagel, Erich R.; Laskin, Julia

    2008-10-01

    Surface-induced dissociation (SID) of the singly protonated complex of vancomycin antibiotic with cell wall peptide analogue (Nα,Nε-diacetyl-L-Lys-D-Ala-D-Ala) was studied using a 6 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS) specially configured for SID experiments. The binding energy between the vancomycin and the peptide was obtained from the RRKM modeling of the time- and energy resolved fragmentation efficiency curves (TFECs) of the precursor ion and its fragments. Electronic structure calculations of the geometries, proton affinities and binding energies were performed for several model systems including vancomycin (V), vancomycin aglycon (VA), Nα,Nε-diacetyl-L-Lys-D-Ala-D-Ala, and non-covalent complexes of VA with N-acetyl-D-Ala-D-Ala and Nα,Nε-diacetyl-L-Lys-D-Ala-D-Ala at the B3LYP/6-31G(d) level of theory. Comparison between the experimental and computational results suggests that the most probable structure of the complex observed in our experiments corresponds to the neutral peptide bound to the vancomycin protonated at the secondary amino group of the N-methyl-leucine residue. The experimental binding energy of 30.9 ± 1.8 kcal/mol is in good agreement with the binding energy of 29.3 ± 2.5 kcal/mol calculated for the model system representing the preferred structure of the complex.

  4. Modeling and Experimental Study of PEM Fuel Cell Transient Response for Automotive Applications

    Institute of Scientific and Technical Information of China (English)

    HUA Jianfeng; XU Liangfei; LIN Xinfan; LU Languang; OUYANG Minggao

    2009-01-01

    This paper presents an analysis of the dynamic response of a low pressure proton exchange membrane (PEM) fuel cell stack to step changes in load, which are characteristic of automotive fuel cell system applications. The goal is a better understanding of the electrical and electrochemical processes when accounting for the characteristic cell voltage response during transients. The analysis and experiment are based on a low pressure 5 kW proton exchange membrane fuel cell (PEMFC) stack, which is similar to those used in several of Tsinghua's fuel cell buses. The experimental results provide an effective improvement reference for the power train control scheme of the fuel cell buses in Olympic demonstration in Beijing 2008.

  5. Modeling and experimental studies to optimize the performance of a hydrogen - bromine fuel cell

    Science.gov (United States)

    Yarlagadda, Venkata Raviteja

    The regenerative Hydrogen-Bromine (H2-Br 2) fuel cells are considered to be one of the viable systems for large scale energy storage because of their high energy conversion efficiency, flexible operation, highly reversible reactions and low capital cost. The preliminary performance of a H2-Br2 fuel cell using both conventional as well as novel materials (Nafion and electrospun composite membranes along with platinum and rhodium sulfide electrocatalysts) was discussed. A maximum power density of 0.65 W/cm2 was obtained with a thicker Br 2 electrode (780 mum) and cell temperature of 45°C. The active area and wetting characteristics of Br2 electrodes were improved upon by either pre-treating with HBr or boiling them in de-ionized water. On the other hand, similar or better performances were obtained using dual fiber electrospun composite membranes (maximum power densities of 0.61 W/cm2 and 0.45 W/cm2 obtained with 25 mum and 65 mum electrospun membranes at 45°C) versus using Nafion membranes (maximum power densities of 0.52 W/cm 2 and 0.41 W/cm2 obtained with Nafion 212 and Nafion 115 membranes at 45°C). The rhodium sulfide (RhxSy) electrocatalyst proved to be more stable in the presence of HBr/Br2 than pure Pt. However, the H2 oxidation activity on RhxS y was quite low compared to that of Pt. In conclusion, a stable H 2 electrocatalyst that can match the hydrogen oxidation activity obtained with Pt and a membrane with low Br2/Br- permeability are essential to prolong the lifetime of a H2-Br2 fuel cell. A 1D mathematical model was developed to serve as a theoretical guiding tool for the experimental studies. The impact of convective and diffusive transport and kinetic rate on the performance of a H2-Br2 fuel cell is shown in this study. Of the two flow designs (flow-by and flow-through) incorporated in this study, the flow-through design demonstrated better performance, which can be attributed to the dominant convective transport inside the porous electrode. Both

  6. Experimental study of a fuel cell power train for road transport application

    Science.gov (United States)

    Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

    The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

  7. FEM simulations and experimental studies of the temperature field in a large diamond crystal growth cell

    Institute of Scientific and Technical Information of China (English)

    Li Zhan-Chang; Jia Xiao-Peng; Huang Guo-Feng; Hu Mei-Hua; Li Yong; Yan Bing-Min; Ma Hong-An

    2013-01-01

    We investigate the temperature field variation in the growth region of a diamond crystal in a sealed cell during the whole process of crystal growth by using the temperature gradient method (TGM) at high pressure and high temperature (HPHT).We employ both the finite element method (FEM) and in situ experiments.Simulation results show that the temperature in the center area of the growth cell continues to decrease during the process of large diamond crystal growth.These results are in good agreement with our experimental data,which demonstrates that the finite element model can successfully predict the temperature field variations in the growth cell.The FEM simulation will be useful to grow larger high-quality diamond crystal by using the TGM.Furthermore,this method will be helpful in designing better cells and improving the growth process of gem-quality diamond crystal.

  8. FEM simulations and experimental studies of the temperature field in a large diamond crystal growth cell

    International Nuclear Information System (INIS)

    We investigate the temperature field variation in the growth region of a diamond crystal in a sealed cell during the whole process of crystal growth by using the temperature gradient method (TGM) at high pressure and high temperature (HPHT). We employ both the finite element method (FEM) and in situ experiments. Simulation results show that the temperature in the center area of the growth cell continues to decrease during the process of large diamond crystal growth. These results are in good agreement with our experimental data, which demonstrates that the finite element model can successfully predict the temperature field variations in the growth cell. The FEM simulation will be useful to grow larger high-quality diamond crystal by using the TGM. Furthermore, this method will be helpful in designing better cells and improving the growth process of gem-quality diamond crystal. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  9. Experimental Study of Entropy Production in Cells under Alternating Electric Field

    Science.gov (United States)

    Ding, Chang-Jiang; Luo, Liao-Fu

    2012-08-01

    We put forward a new method for measuring the entropy production in the living cell. It involves heating the sample by alternating the electric field and recording the outward heat flow. The entropy production in a normal cell MCF10A and a cancerous cell MDA-MB-231 were measured and compared. The results show that the method is effective for the entropy measurement of a living organism. The scaled electro-induced entropy production rate (SEEP) of MDA-MB-231 monotonically increases with the electric field strength at 5-40 V/cm. While that of MCF10A changes non-monotonically and there exists a peak at 5-30 V/cm. The electro-induced entropy production ratio (EEPR) is smaller than 1 in a large range of field strengths, from 5 to 25 V/cm, which reveals that under 5-25 V/cm electric field exposure, the direction of the entropy flow may be changed from normal tissue to cancerous cells. We present a facile and effective strategy for experimentally investigating the thermodynamic properties of the cell and give a deeper insight into the physical difference between normal and cancerous cells under electric field exposure.

  10. Mitochondria-Rich Cells as Experimental Model in Studies of Epithelial Chloride Channels

    DEFF Research Database (Denmark)

    Willumsen, Niels J.; Amstrup, Jan; Møbjerg, Nadja;

    2002-01-01

    The mitochondria-rich (mr) cell of amphibian skin epithelium is differentiated as a highly specialised pathway for passive transepithelial transport of chloride. The apical membrane of mr cells expresses several types of Cl- channels, of which the function of only two types has been studied...

  11. [Advances in the experimental study of the use of mesenchy- mal stem cells for the treatment of inhalation injury].

    Science.gov (United States)

    Feng, Zhu; Guanghua, Guo

    2015-06-01

    Inhalation injury seriously threatens the survival and quality of life in burn and trauma patients. So far there is no breakthrough in the treatment of inhalation injury. A significant advance has been witnessed in the experimental study of the use of stem cells in the treatment of lung injury in recent years. In this paper, according to the results of our study in the systemic transplantation of bone marrow mesenchymal stem cells for the treatment of inhalation injury, the effect of mesenchymal stem cells on anti-inflammatory process and repair of lung tissues in inhalation injury, and its possible mechanisms are reviewed.

  12. A study on decontamination and decommissioning of experimental DUPIC equipment at PIEF 9405 hot cell

    International Nuclear Information System (INIS)

    The characterization experiment for powder and sintered fuel had been performed using about 1 kg-U spent PWR fuel at No. 9405 hot-cell in PIEF(Post Irradiated Experiment Facility) since early in 1999. Currently, The experiments in PIEF have been completed. It is supposed to dismantle and decontaminate the installed equipment by the end of year 2000. Since all of DUPIC equipment in hot-cell are contaminated by high radioactive material, the decontamination and dismantlement must br performed remotely by M/S manipulator. During the radioactive waste packing and transportation, the reduction method of radiation exposure has to be considered. Firstly, This report describes the basic plan for dismantlement/decontamination of the characterization equipment(power and sintered fuel). And methods of measurement/packing/ transportation, method of dismantlement/decontamination of the experimental apparatus and the reduction method of radiation dose exposure, etc. are explained in order

  13. Experimental Study on the Radiosensitivity and Chemosensitivity of A-431 Cell Line

    International Nuclear Information System (INIS)

    The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. Human epidermoid carcinoma A-431 cell line were irradiated by 2, 4, 6, 8, 10 Gy at a dose rate of 210 cGy/min using 60Co Irradiator ALDORADO 8 and then were exposed to bleomycin or cisplatin at concentration of 2 μg/ml for 1 hour. The viable cells were determined for each radiation dose and/or each drug at the 4th day and cell surviving curves were obtained using semiautomated MTT assay. The surviving fraction after irradiation of 2 Gy was 0.99, and there was not significant difference of surviving fraction in comparison with the control group on A-431 cell line (p>0.05). But there were significant differences of surviving fractions at doses of 4, 6, 8, 10 Gy in comparison with the control group (p0.05).

  14. Experimental and numerical studies of local current mapping on a PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Hwnag, J.J. [Department of Environment and Energy, National University of Tainan, Tainan 700 (China); Chang, W.R. [Department of Landscape Architecture, Chung-Hua University, Hsinchu 300 (China); Peng, R.G. [Department of Mechanical Engineering, National Chiao Tong University, Hsinchu 300 (China); Chen, P.Y. [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 300 (China); Su, A. [Department of Mechanical Engineering and Fuel Cell Center, Yuan Ze University, Taoyuan (China)

    2008-10-15

    Local current distribution on a PEM fuel cell has been mapped experimentally by using a special-designed single cell fixture. It is composed of a composite cathodic flow-field plate, a membrane electrode assembly (MEA) and a stainless-steel anodic flow-field plate. An array of 16 individual conductive segments was distributed on the composite plate. A self-made MEA is in direct contact with the segmented current collectors. Regional-averaged current through each segment is determined by using the Hall-effect sensor. To ensure the data reliability, a comparison of polarization curves was made between the composite flow-field plate and the conventional flow-field plate. Then, the effects of flow-field patterns, dew points of the cathodic feedings and cathodic stoichiometrics on the local current distribution were examined. The transient variation of the local current distribution on the cathode under supersaturated conditions was further visualized to illustrate the flooding phenomena in different flow patterns. This technique developed by the present work has contributed to knowledge and understanding the local current distributions in a PEM fuel cell that is helpful in designing the fuel-cell components. (author)

  15. An experimental study on the radiosensitivity and chemosensitivity of MG-63 cell line

    International Nuclear Information System (INIS)

    The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. For this study, cell surviving curves were obtained for human osteosarcoma MG-63 cell line using semiautomated MTT ass ay. 2, 4, 6, 8, 10 Gy were irradiated at a dose rate of 210 cGy/min using 60Co Irradiator ALDORADO 8. After irradiation, MG- 63 cell lines (3X104 cells/ml) were exposed to bleomycin and cisplatin at concentration of 0.2, 2, 20 μg/ml for 1 hour respectively. The viable cells were determined for each radiation dose and/or each concentration of drug. And they were compared to control values. The obtained results were as follows: 1. There was significant difference of surviving fraction at 4, 6, 8, 10 Gy on MG-63 cell line (p<0.05). 2. There was significant difference of cytotoxicity of bleomycin or cisplatin at all concentration of 0.2, 2, 20 μg/ml (p<0.05) on mg-63 cell line. The cytotoxicity of cisplatin was more effective than bleomycin at concentration after irradiation of 2 Gy on MG-63 cell line. 3. there was significant difference of cytotoxicity of bleomycin or cisplatin at all concentration after irradiation of Gy on MG-63 cell line. 4. There was significant difference of cytotoxicity of bloeomycin or cisplatin at concentration of 20 μg/ml after irradiation than that of irradiation alone (p<0.01). but there was no significant difference of cytotoxicity of bleomycin at concentration of 20 μg/ml after irradiation of 10 Gy than that of irradiation alone.

  16. Experimental study of piperlongumine inducing apoptosis of human breast adenoma MDA-MB-231 cells

    Institute of Scientific and Technical Information of China (English)

    Zhifeng Yao; Jianxin Yao; Xia He; Zhanfeng Li; Yongbiao Liu

    2013-01-01

    Objective: The aim of the study was to investigate the apoptosis induced by piperlongumine on human breast adenoma MDA-MB-231 cells and the mechanism involved. Methods: Human breast adenoma MDA-MB-231 cells line was cultured in vitro. The inhibitory effect of piperlongumine on the proliferation of human breast adenoma MDA-MB-231 cells was measured by CCK-8 assay. Distribution of cell cycle was analyzed by flow cytometry. The apoptosis rates of MDA-MB- 231 cells were measured using Annexin V/PI staining. The flow cytometry with the probe of DCFH-DA was used to detect the intracellular reactive oxygen species levels. Western blot was used to explore the protein expression of Bcl-2 and Bax. Results: The CCK-8 assay showed that piperlongumine had an inhibiting effect on the proliferation of MDA-MB-231 cells in a concentration- and time-dependent manner. MDA-MB-231 cells were markedly arrested at G0/G1 phase after treatment of piperlongumine. Piperlongumine induced apoptosis of MDA-MB-231 cells obviously. The level of intracellular reactive oxygen species was increased in a dose-dependent manner. The antioxidant N-acetyl-L-cystein inhibited the apoptosis of cells and the level of intracellular reactive oxygen species was also decreased. By Western blot analysis, we found the expression of Bax was up-regulated whereas that of Bcl-2 was down-regulated in a concentration-dependent manner. Conclusion: Piperlongumine possesses a significant function for inhibiting proliferation, arresting cells at G0/G1 phase and inducing apoptosis of MDA-MB-231 cells, which seems to be associated with the increased generation of intracellular reactive oxygen species as well as the down-regulation of Bcl-2 and up-regulation of Bax.

  17. Natural dye extracted from karkadah and its application in dye-sensitized solar cells: experimental and density functional theory study.

    Science.gov (United States)

    Reda, S M; Soliman, K A

    2016-02-01

    This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100  mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed. PMID:26836089

  18. The effect of spiritual healing on in vitro tumour cell proliferation and viability - an experimental study

    DEFF Research Database (Denmark)

    Zachariae, R.; Hojgaard, L.; Zachariae, C.;

    2005-01-01

    ), and a nonadherent mouse B-lymphoid cell line (HB-94). Analyses of variance (ANOVAs) revealed no significant main or dose-related effects of spiritual healing compared to controls for either of the two cell lines or any of the assays (P-values between 0.09 and 0.96). When comparing healing and control across all......Alternative treatments such as spiritual healing and prayer are increasingly popular, especially among patients with life-threatening diseases such as cancer. According to theories of spiritual healing, this intervention is thought to influence living cells and organisms independently...... of the recipient's conscious awareness of the healer's intention. The aim of this study was to test the hypothesis that spiritual healing will reduce proliferation and viability of two cancer cell lines in vitro. Three controlled experiments were conducted with three different healers and randomised allocation...

  19. Toward new fuel cell support materials: a theoretical and experimental study of nitrogen-doped graphene.

    Science.gov (United States)

    Seo, Min Ho; Choi, Sung Mook; Lim, Eun Ja; Kwon, In Hye; Seo, Joon Kyo; Noh, Seung Hyo; Kim, Won Bae; Han, Byungchan

    2014-09-01

    Nano-scale Pt particles are often reported to be more electrochemically active and stable in a fuel cell if properly displaced on support materials; however, the factors that affect their activity and stability are not well understood. We applied first-principles calculations and experimental measurements to well-defined model systems of N-doped graphene supports (N-GNS) to reveal the fundamental mechanisms that control the catalytic properties and structural integrity of nano-scale Pt particles. DFT calculations predict thermodynamic and electrochemical interactions between N-GNS and Pt nanoparticles in the methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR). Moreover, the dissolution potentials of the Pt nanoparticles supported on GNS and N-GNS catalysts are calculated under acidic conditions. Our results provide insight into the design of new support materials for enhanced catalytic efficiency and long-term stability.

  20. [Dynamics of osteogenesis associated with inoculation of autologous stromal cells from rat adipose tissue (experimental-morphological study)].

    Science.gov (United States)

    Grigoryan, A S; Orlov, A A; Saburina, I N; Zurina, I M; Sysoev, S D

    2015-01-01

    Experiment was evaluated on 40 male Wistar rats. On the experimental model of mandible injury, bone autologous graft from tibia was placed on the surface of mandible (host bone). In the main experimental group, consisting of 20 animals, autologous rat adipose-derived stromal cells (ADSCs) were inoculated in space between autograph and host bones. ADSCs were not inoculated in the group of comparison. In experimental group with inoculated cells, the formation of a new fibroreticular bone structures in space between autograph and host bone was observed. These structures further underwent secondary reorganization and differentiation during the process of remodeling. As a result of the conducted study it was shown that in the experimental group by the day 180, statistically significant reduction of the area occupied by an immature fibroreticular bone took place. The reported phenomenon could be explained as a result of decline of the number of active cells in the population of inoculated ADSC, which is in consent with theory of limited cell division number due to telomeres shortening, described by Hayflick L. and Moorhead P.S. (1961). PMID:26571800

  1. Experimental study of retinoic acid on improving iodide uptake in MCF-7 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    FU Hong-Liang; WU Jing-Chuan; DU Xue-Liang; LI Jia-Ning; WU Zhen; ZOU Ren-Jian

    2005-01-01

    The study aims to investigate the effect of retinoic acid on the iodide uptake of MCF-7 cells and its mechanism. The iodide uptake and expression of hNIS(human sodium/iodide symporter)mRNA in the breast cancer MCF-7 cells were compared individually before and after the intervention of all-trans retinoic acid (ATRA) with the iodide uptake assay and RT-PCR. The following results are obtained: (1) when treated with all-trans retinoic acid in the concentration of 1.0 μmol/L, the capacity of iodide uptake of MCF-7 cells reached about 1.5 times of the basal state; (2) 12 h after the intervention of 1.0 μmol/L ATRA, the hNISmRNA expression of the MCF-7 cells reached maximum. The study shows that all-trans retinoic acid has the effect to improve the iodide uptake of the MCF-7 cells and this effect may result from its up-regulation of the hNISmRNA expression.

  2. An experimental study on astrocytes promoting production of neural stem cells derived from mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-feng; FANG Feng; FU Jin-rong; DONG Yong-sui; YE Du-yun; SHU Sai-nan; ZHEN Hong; LI Ge

    2005-01-01

    Background The production of neural stem cells (NSCs) derived from embryonic stem (ES) cells was usually very low according to previous studies, which was a major obstacle for meeting the needs of clinical application. This study aimed at investigating whether astrocytes could promote production of NSCs derived from ES cells in vitro.Methods Mouse ES cells line-D3 was used to differentiate into NSCs with astrocytes as inducing stromal cells by means of three-stage differentiation procedure. Another group without astrocytes served as control. The totipotency of ES cells was identified by observation of cells' morphology and formation of teratoma in severe combined immunodeficiency disease (SCID) mice. The quantity and purity of NSCs derived from ES cells were analyzed using clonogenic assay, immunohistochemical staining and flow cytometry assay. The plasticity of NSCs was detected by differentiating test. Octamer-binding transcription factor 4 (Oct-4) and nestin, the specific marker genes of ES cells and NSCs respectively, were detected continuously using reverse transcription-polymerase chain reaction (RT-PCR) method to monitor the process of cell differentiation. Results The ES cells of D3 line could maintain the ability of differentiating into cellular derivations of all three primary germ layers after continuous passage culture. At the end of two-stage of inducing process, 23.2±3.5 neurospheres per plate formed in astrocyte-induced group and only 0.8±0.3 per plate in the control group (clonogenic assay, P<0.01), and the ratio of nestin positive cells was (50.2±2.8)% in astrocyte-induced group and only (1.4±0.5)% in the control group (flow cytometry, P<0.01). With the induction undergoing, the expression of Oct-4 gradually decreased and then disappeared, while the expression of nestin was increased step by step, and the ratio of nestin positive cells was up to 91.4% by the three-stage differentiation. The nestin positive cells could be further induced into

  3. Experimental study of proton exchange membrane fuel cell; Estudo experimental de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Luis Evelio Garcia; Oliveira, Amir Antonio Martins [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], e-mail: evelio@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    Here we present a thermodynamic and chemical kinetic analysis of the methane steam reforming for production of 5 kw of electrical power in a PEM fuel cell. The equilibrium analysis is based on the method of element potentials to find the state of minimum Gibbs free energy for the system and provides the equilibrium concentration of the reforming products. The objective of this analysis is to obtain the range of reforming temperature, pressure and steam-methane molar ratio that results in maximum hydrogen production subjected to low carbon monoxide production and negligible coke formation. The thermal analysis provides the heat transfer rates associated with the individual processes of steam production, gas-phase superheating and reforming necessary to produce 5 kw of electrical power in a PEM fuel cell and allows for the calculation of thermal efficiencies. Then, the chemical reaction pathways for hydrogen production in steam reforming are discussed and the available chemical, adsorption and equilibrium constants are analyzed in terms of thermodynamic consistency. This analysis provides the framework for the reactor sizing and for establishing the adequate operation conditions. (author)

  4. Semi-industrial experimental study on bauxite separation using a cell-column integration process

    Science.gov (United States)

    Zhang, Ning-ning; Zhou, Chang-chun; Cong, Long-fei; Cao, Wen-long; Zhou, You

    2016-01-01

    The cyclonic-static micro-bubble flotation column (FCSMC) is a highly efficient mineral processing equipment. In this study, a cell-column (FCSMC) integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis. The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon (A/S) mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of "fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns". Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-column integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

  5. EXPERIMENTAL STUDY ON APOPTOSIS OF GASTRIC CANCER CELLS INDUCED BY TRICHOSANTHIN

    Institute of Scientific and Technical Information of China (English)

    张曙; 胡梅洁; 吴裕圻; 吴云林

    2001-01-01

    Objective To investigate whether the apoptosis is involved in the mechanism of cytotoxicity of trichosanthin to gastric cancer cells. Methods Morphologic studies and TUNEL stainning were used to explore qualitatively and quantitatively the apoptotic status of gastric cancer cells before and after treatment with trichosanthin. Results In the experiment in vitro , when gastric cancer cells SGC-7901 were treated by trichosanthin (0.1μg /ml , 36h ), some typical apoptotic morphologic changes occured. A significant increase of apoptotic index ( AI ) was from (3.78±1.11 )%, (3.98±1.12)% and (3.85±1.08)% at 36, 42, 48h to (11.30 ±2.33)%, (10.22±2.00)% and (11.18±1.85)%, respectively ( P <0.01 ). In the experiment in vivo , nude mice with SGC-7901 xenografted tumor were treated by trichosanthin (0.3mg· kg-1·d-1 ,× 5d, intraperitoneal injection ), some typical apoptotic morphologic changes were observed. These apoptotic cells were limited only in xenografted tumor. AI increased significantly from (4.95±1.94 )% to (8.75± 1.38)%, (P<0.01). Conclusion The apoptosis would be involved in the mechanism of cytotoxicity of trichosanthin to gastric cancer cells.

  6. MATHEMATICAL MODELING AND NUMERICAL STUDY OF THE HYDRODYNAMICS OF THE EXPERIMENTAL ELECTROCHEMICAL CELL WITH ROTATING DISK MEMBRANE

    Directory of Open Access Journals (Sweden)

    Kovalenko A. V.

    2013-12-01

    Full Text Available This article investigates hydrodynamic of experimental electrochemical cell with rotating disk in the cation exchange membrane. We have also investigated the flow in open, with the free surface of the solution and in hermetically closed cells. The main regularities of the hydrodynamics of the experimental cell at its real size were set

  7. Pharmacokinetics of intravitreal glial cell line-derived neurotrophic factor: experimental studies in pigs

    DEFF Research Database (Denmark)

    Ejstrup, Rasmus; Kiilgaard, J F; Tucker, B A;

    2010-01-01

    The purpose of this study was to establish the intravitreal (ITV) pharmacokinetics of glial cell line-derived neurotrophic factor (GDNF) and observe possible complications after ITV injection. Twenty Danish landrace pigs and 34 eyes were included in the study; 30 were injected with 100 ng of GDNF......, two controls were injected without GDNF, and two received no injection. At post-injection time points of 1, 2, 3, 6 hours (h), 1, 2, 4 or 7 days (d) eyes were enucleated and the ITV concentration of GDNF (cGDNF) was determined by enzyme-linked immunosorbent assay, and activity was tested using...... a retinal ganglion cell line (RGC5) bioassay. Indirect ophthalmoscopy, intraocular pressure assessment, and fundus photography were performed before enucleation. There was initial variability in the cGDNF, but after 24h GDNF was cleared in a monoexponential fashion with a half-life of 37 h (CL 33-43 h...

  8. Glucose and lipid metabolism in insulin resistance : an experimental study in fat cells

    OpenAIRE

    Burén, Jonas

    2003-01-01

    Type 2 diabetes is usually caused by a combination of pancreatic β-cell failure and insulin resistance in target tissues like liver, muscle and fat. Insulin resistance is characterised by an impaired effect of insulin to reduce hepatic glucose production and to promote glucose uptake in peripheral tissues. The focus of this study was to further elucidate cellular mechanisms for insulin resistance that may be of relevance for type 2 diabetes in humans. We used rat and human adipocytes as an es...

  9. Effect of neurotransmitters and bone marrow cells for neuronal regeneration in iatrogenic spinal cord injury: An experimental study

    OpenAIRE

    John P; Paulose C; Sreekanth R

    2010-01-01

    Background: Spinal cord trauma is a major health problem with associated physical, social, economic and psychological sequelae. Despite many advances in research and treatment modalities, the pathophysiology of spinal cord injury remains unclear, and morbidity and mortality among these patients remain high. This experimental study investigates the regenerative cell proliferation effects of bone marrow supplemented with neurotransmitters combinations in the regeneration of spinal cord injury ...

  10. Analytical and Experimental Studies of the Degradation in Hydrogenated Amorphous Silicon Solar Cells and Materials.

    Science.gov (United States)

    Yeung, Ping Fai

    1995-01-01

    An improved understanding of a-Si:H pin solar cells stability was obtained by studying light induced degradation in a-Si:H films and in devices. The current -voltage characteristics and the quantum efficiencies of a-Si:H pin solar cells were measured as a function of intrinsic layer thickness, bias light intensity and degradation condition. Photoconductivity measurements on device quality intrinsic a-Si:H thin film materials showed that the majority carrier (electron) mutau product degraded from 3times 10^{-7}rm cm ^2/V to 2times 10^{ -7}rm cm^2/V after 6 minutes of 50-Suns light illumination. Using a dual beam technique with steady white light and modulated monochromatic light, a degradation profile was detected in the degraded materials. These results suggest that inhomogeneous degradation may be important to understanding the stability of a-Si:H pin solar cells. An analytical model was developed for degradation in a-Si:H pin solar cells based on inhomogeneous degradation, which was used to explain the 'blue-dip' effect observed in the quantum efficiencies of degraded cells. A new method was developed to investigate the minority carrier (hole) diffusion length in device quality a-Si:H films as a function of degradation. This method uses the Schottky barrier structure to establish a depletion region, which can be controlled by the applied voltage and the bias light intensity. Modulated blue light is used to generate electron hole pairs near the ohmic contacts, and the holes diffuse across the neutral region to be collected. The modulated current is related to the diffusion length of the holes due to this current limiting hole transport. Comparing the results of this new technique to that of the Photocarrier Grating method, the electron drift mobility was found to degrade from rm 2.5cm^2/Vs to rm 0.15cm^2/Vs after 6 minutes of 50-Suns degradation.

  11. Laminar flow in radial flow cell with small aspect ratios: Numerical and experimental study

    DEFF Research Database (Denmark)

    Detry, J. G.; Deroanne, C.; Sindic, M.;

    2009-01-01

    be applied for experiments performed at higher Reynolds numbers. The present study is a numerical analysis of the radial axisymmetrical flow for aspect ratios of 0.125, 0.25, 0.5 and 1 with inlet pipe Reynolds numbers varying from 0 to 2000, aiming at computing the wall shear stress distribution at any...... distance from the center. The simulations provided a thorough description of the complex flow pattern encountered close to the inlet section, which were validated for the laminar regime by dye injection. A total of up to four recirculation zones were identified in both numerical and experimental......Studies on the effect of wall shear stress on soil and biofilm attachment and removal from a surface are one of the many applications of radial axisymmetrical flow. The particular nature of this flow allows taking advantage of a wide range of wall shear Stress applied at the analyzed surface...

  12. Theoretical and experimental studies of water injection scroll compressor in automotive fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Yuanyang Zhao; Liansheng Li; Huagen Wu; Pengcheng Shu [Xian Jiaotong University (China). School of Energy and Power Engineering

    2005-06-01

    A water injection scroll compressor to supply clean compressed air to an automotive fuel cell system is researched. The water is used as both the lubricant and coolant in the compressor. A thermodynamic model of the water injection scroll compressor considering leakage and heat exchange for use with an automotive fuel cell system was developed using the conservation of energy and mass equations and the equation of state. The results show that the scroll compressor has nearly isothermal compression when injecting water in it. Increasing the compressor rotation speed increases the discharge loss and the volumetric efficiency of the scroll compressor. The difference between the calculated power and the isothermal power increases as the compressor rotation speed rises, which means the efficiency of the compressor decreases. Increasing the flow rate of water injected increases the indicated isothermal efficiency and decreases the discharge temperature. Under the condition studied, the mass flow rate of water has the greatest effect on the discharge temperature. (author)

  13. Experimental Study of Polymer Electrolyte Membrane Fuel Cell Performance Under Low Operating Temperatures

    International Nuclear Information System (INIS)

    In this study, the performance characteristics of a polymer electrolyte membrane fuel cell (PEMFC) were investigated at low operating temperatures under steady-state and dynamic conditions. The performance of the PEMFC was analyzed according to the external humidifying rate and air stoichiometry. The ohmic resistance was also investigated using EIS tests. At the operating temperature of 35 ℃, voltage fluctuation occurred to a greater degree compared to that at 45 ℃. Therefore, it was found that the air stoichiometry should be higher than 2.5 for the stable operation of the fuel cell. In addition, the relative humidity of the reactant gases should be higher than 60 to reduce the ohmic resistance

  14. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψm) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  15. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Viitanen, Matti [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Department of Geriatrics, Turku City Hospital and University of Turku, Turku (Finland); Sundström, Erik [Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Baumann, Marc [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Poyhonen, Minna [Department of Clinical Genetics, Helsinki University Hospital, HUSLAB, Helsinki (Finland); Tikka, Saara [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Behbahani, Homira, E-mail: homira.behbahani@ki.se [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Karolinska Institutet Alzheimer' s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden)

    2013-02-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ{sub m}) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  16. The experimental study of genetic engineering human neural stem cells mediated by lentivirus to express multigene

    Institute of Scientific and Technical Information of China (English)

    CAI Pei-qiang; TANG Xun; LIN Yue-qiu; Oudega Martin; SUN Guang-yun; XU Lin; YANG Yun-kang; ZHOU Tian-hua

    2006-01-01

    Objective:To explore the feasibility to construct genetic engineering human neural stem cells (hNSCs)mediated by lentivirus to express multigene in order to provide a graft source for further studies of spinal cord injury (SCI).Methods: Human neural stem cells from the brain cortex of human abortus were isolated and cultured, then gene was modified by lentivirus to express both green fluorescence protein (GFP) and rat neurotrophin-3(NT-3); the transgenic expression was detected by the methods of fluorescence microscope, dorsal root ganglion of fetal rats and slot blot.Results: Genetic engineering hNSCs were successfully constructed. All of the genetic engineering hNSCs which expressed bright green fluorescence were observed under the fluorescence microscope. The conditioned medium of transgenic hNSCs could induce neurite flourishing outgrowth from dorsal root ganglion (DRG). The genetic engineering hNSCs expressed high level NT-3 which could be detected by using slot blot.Conclusions: Genetic engineering hNSCs mediated by lentivirus can be constructed to express multigene successfully.

  17. Experimental Study of Nonequilibrium Electrodeposition of Nanostructures on Copper and Nickel for Photochemical Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Rajesh K. Shanmugam

    2011-01-01

    Full Text Available To increase the performance of photochemical fuel cells, nonequilibrium electrodeposition has been performed on Cu and Ni to make photosensitive anodes. Processing parameters including electrolyte concentration, and electrode potential were studied using cyclic voltammetry. Scanning electron microscopy (SEM and X-ray Spectroscopy (EDS were performed to understand the formation of the nanostructures during the nonequilibrium deposition of copper fractals. An increase in the deposition rate was observed with the increase in electrolyte concentration (from 0.05 M to 1.0 M. Similar trend was found when the cathode potential was decreased from −0.5 V to −4.5 V. The effect of substrate material was also examined. Porous fractal structures on copper were achieved, while the deposited material showed high density of surface cracks on nickel. The fractal structures deposited on copper electrode with the increased surface area were converted into copper oxide by oxidation in air. Such oxide samples were made into anodes for photochemical fuel cell application. We demonstrated that an increase in the magnitude of open circuit output voltage is associated with the increase in the fractal surface area under the ultraviolet irradiation test conditions. However, the electrodeposited fractals on nickel showed very limited increase in the magnitude of open circuit voltage.

  18. Experimental Study on Treatment of Glioma by Embyonic Neural Stem Cell Transplnation in Rats

    Institute of Scientific and Technical Information of China (English)

    LUO Jie; ZHANG Li; TU Hanjun; HU Juntao; LI Xinjian; LI Dongsheng; LEI Ting

    2007-01-01

    The neural stem cells in Wistar rats were cultured in vitro, purified, and transplanted into C6 glioma model in order to observe their biological characters and provide a basic foundation for treatment of neurological diseases by neural stem cell transplantation. The cells at hippocampal area from gestation 15-day rats were cultured in vitro, and frozen and preserved in liquid nitrogen. C6 tu-mor-bearing models (n=25) and neural stem cells transplantation models (n=35) were established.When the tumor grew to 3 to 4 weeks,5 rats in each group were randomly selected for MRI examina-tion. At different intervals, the rats were perfused and sampled for HE staining, GFAP and BrdU im-munohistochemical staining. The results showed that after resuscitation of neural stem cells at 1-4 passages, the cell viability was 40%-63% with the difference being not significant. The cells could proliferate, passage, and most cells transplanted into glioma model survived. The mean survival time in neural stem cell transplantation group and control was 4.28 and 3.88 weeks respectively, and the average tumor size in the former was smaller than in the latter. It was concluded that embryonic neu- ral stem cells in rats could proliferate and differentiate, and after resuscitation the biological charac- teristic and viability of the cells were not influenced. Neural stem cells had inhibitory effects on the growth of glioma cells and could prolong the survival of rat model.

  19. From cell culture to population enquiry: Experimental, clinical and epidemiological studies on restenosis post coronary intervention

    NARCIS (Netherlands)

    A.G. Violaris (Andonis)

    1998-01-01

    textabstractPercutaneous coronary intervention is widely used in the treatment of coronaty artery disease but currently limited by restenosis in a proportion of cases. We investigated the restenosis problem using complimentary experimental, clinical and epidemiological approaches.

  20. EXPERIMENTAL STUDY ON PLASTICITY OF PROLIFERATED NEURAL STEM CELLS IN ADULT RATS AFTER CEREBRAL INFARCTION

    Institute of Scientific and Technical Information of China (English)

    Bo Zhang; Ren-zhi Wang; Zhi-gang Lian; Yang Song; Yong Yao

    2006-01-01

    Objective To investigate whether there is endogenous neural stem cell proliferation and whether these proliferated neural stem cells represent neural plasticity in the adult rats after cerebral infarction.Methods Cerebral infarction models of rats were established and the dynamic expression of bromodeoxyuridine (BrdU), BrdU/polysialylated neural cell adhesion molecule (PSA-NCAM) were determined by immunohistochemistry and immunofluorescence staining. BrdU was used to mark dividing neural stem cells. PSA-NCAM was used to mark the plasticity of neural stem cells.Results Compared with controls, the number of BrdU-positive cells in the subventricular zone (SVZ) and hippocampus increased significantly at 1st day after cerebral infarction (P<0.05), reached maximum at 7th day, decreased markedly at 14th day, but it was still elevated compared with that of the controls (P<0.05). The number of BrdU-labeled with PSA-NCAM-positive cells increased significantly at 7th day (P<0.05 ), reached maximum at 14th day,markedly decreased at 28th day, but it was still elevated compared with that of the controls (P<0.05). It was equal to 60% of the number of BrdU-positive cells in the same period.Conclusion Cerebral infarction may stimulate the proliferation of endogenous neural stem cells in situ and most proliferated neural stem cells represent neural plasticity.

  1. An experimental and theoretical approach to the study of the photoacoustic signal produced by cancer cells

    Directory of Open Access Journals (Sweden)

    Rafael Pérez Solano

    2012-03-01

    Full Text Available The distinctive spectral absorption characteristics of cancer cells make photoacoustic techniques useful for detection in vitro and in vivo. Here we report on our evaluation of the photoacoustic signal produced by a series of monolayers of different cell lines in vitro. Only the melanoma cell line HS936 produced a detectable photoacoustic signal in which amplitude was dependent on the number of cells. This finding appears to be related to the amount of melanin available in these cells. Other cell lines (i.e. HL60, SK-Mel-1, T47D, Hela, HT29 and PC12 exhibited values similar to a precursor of melanin (tyrosinase, but failed to produce sufficient melanin to generate a photoacoustic signal that could be distinguished from background noise. To better understand this phenomenon, we determined a formula for the time-domain photoacoustic wave equation for a monolayer of cells in a non-viscous fluid on the thermoelastic regime. The theoretical results showed that the amplitude and profile of the photoacoustic signal generated by a cell monolayer depended upon the number and distribution of the cells and the location of the point of detection. These findings help to provide a better understanding of the factors involved in the generation of a photoacoustic signal produced by different cells in vitro and in vivo.

  2. Suitability of polyelectrolyte shells modified with fullerene derivate for immunoisolation of cells. Experimental study.

    Science.gov (United States)

    Borkowska, M; Godlewska, E; Antosiak-Iwańska, M; Kinasiewicz, J; Strawski, M; Szklarczyk, M; Granicka, L H

    2012-12-01

    The polymeric permiselective membranes application for immunoisolation of cells separating the transplanted cells from the host immunological system may eliminate immunosuppressive therapy during transplantation. The suitability of polyelectrolyte modified nanocoatings for immunoisolation of cells was assessed. The polymeric shells modified with incorporated fullerene derivate were applied for encapsulation of human T-lymphocyte cell line Jurkat or rat pancreatic islets of Langerhans using layer-by-layer technique. Hydroxylated fullerene was incorporated to the polyelectrolyte shell for hydrophility increase as well as for layer stability improvement. Evaluation with AFM, FTIR, fluorescence microscopy confirmed the nanocoating presence on the encapsulated cells. It was observed that polylysine-polyethyleneimine membrane with incorporated fullerenol allowed for encapsulated cells functioning in vitro. Membrane conformation applied for encapsulation of pancreatic rat islets allowed for glucose level decline during xenotransplantation into mice. The elaborated nanocoating may be recommended as the possible alternative to the space consuming microencapsulation for biomedical purposes. PMID:23029999

  3. Individual cell motility studied by time-lapse video recording: influence of experimental conditions

    DEFF Research Database (Denmark)

    Hartmann-Petersen, R; Walmod, P S; Berezin, A;

    2000-01-01

    BACKGROUND: Eukaryotic cell motility plays a key role during development, wound healing, and tumour invasion. Computer-assisted image analysis now makes it a realistic task to quantify individual cell motility of a large number of cells. However, the influence of culture conditions before...... and during measurements has not been investigated systematically. METHODS: We have evaluated intraassay and interassay variations in determinations of cellular speed of fibroblastoid L929 cells and investigated the effects of a series of physical and biological parameters on the motile behavior of this cell...... line. Cellular morphology and organization of filamentous actin were assessed by means of phase-contrast and confocal laser scanning microscopy and compared to the corresponding motility data. RESULTS: Cell dissociation procedure, seeding density, time of cultivation, and substrate concentration were...

  4. Improvement of Thymopoiesis after Hematopoietic Stem Cell Transplantation by Cytokines: Translational studies in experimental animal models

    NARCIS (Netherlands)

    E-J. Wils (Evert-Jan)

    2011-01-01

    textabstractAllogeneic hematopoietic stem cell transplantation (AlloHSCT) is a powerful treatment modality that is frequently applied as part of treatment of hematological malignancies, aplastic anemia and inborn errors of hematopoietic progenitor cells. A major drawback of alloHSCT is the treatment

  5. THE EXPERIMENTAL STUDY ON THE CELL APOPTOSIS AND EXPRESSION OF BCL-2 PROTEIN IN INTRACEREBRAL HEMORRHAGE IN MODEL OF RATS

    Institute of Scientific and Technical Information of China (English)

    Bao Gang; Guo Ning; Zhang Zhonglin; Chen Wei; Bao Dehu

    2006-01-01

    Otjective To study whether there is the apoptosis of neural cells and the expressionof Bcl-2 protein in intracerebral hemorrhage (ICH) in model of rats, for the further understanding the mechanism of the delayed damage of the neural cells around the hematoma after ICH. Methods Fifty SD rats were randomly divided into 5 groups, ten in each. With the Group A as the control, the rest 40 were used to set up intracerebral hemorrhage model. The brains were taken out at 12th, 24th, 48th and 72th hours, respectively. Apoptosis cells were detected with terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and the expression of Bcl-2 protein was detected with immunochemical stainging methed (SP). Results In the control group, no apoptosis cells and Bcl-2protein were detected. In rest groups, the apoptosis cells and Bcl-2 protein were expressed in different degree.Apoptosis rates verified and corresponded with the time after ICH, with the peak at 48th -72th hour after hemorrhage.The peak rate of apoptosis cells was (24. 50± 2.69)% and Bcl-2 protein expression was (20. 76 ± 1.97)% . There was significant difference between the experimental groups and control (P<0.05), and no linear relationship between the apoptosis rate and the expression of Bcl-2 protein. Conclusion Apoptosis may be an important factor in the secondary trauma of ICH. There is a time leg after hemorrhage. All this is instructive to clinical treatment in time. Bcl-2 protein keeps increasing in a certain time after hemorrhage, but not synchronize with the cell apoptosis. This indicates that bcl-2 has the effect to reduce the apoptosis of neural cells.

  6. Experimental Study of Rat Beta Islet Cells Cultured under Simulated Microgravity Conditions

    Institute of Scientific and Technical Information of China (English)

    ChunSONG; Xiu-QingDUAN; XiLI; Li-OuHAN; PingXU; Chun-FangSONG:; Lian-HongJIN

    2004-01-01

    To observe the effects of simulated microgravity on beta islet cell culture, we have compared the survival rates and the insulin levels of the isolated rat islet cells cultured at micro- and normal gravity conditions. The survival rates of the cells cultured were determined by acridine orange-propidium iodide double-staining on day 3,7 and 14. The morphology of the cells was observed by electron microscopy.Insulin levels were measured by radio immuno assays. Our results show that the cell number cultured underthe microgravity condition is significantly higher than that under the routine condition (P<0.01). Some tubular structure shown by transmission electron microscopy, possibly for the transport of nutrients, were formed intercellularly in the microgravity cultured group on day 7. There were also abundant secretion particles and mitochondria in the cytoplasm of the cells. Scanning electron microscopy showed that there were holes formed between each islet, possibly connecting with the nutrient transport tubules. The microgravity cultured group also has higher insulin levels in the media as compared with the control group (P<0.01). Our results indicate that microgravity cultivation of islet cells has advantages over the routine culture methods.

  7. Experimental Study of Rat Beta Islet Cells Cultured under Simulated Microgravity Conditions

    Institute of Scientific and Technical Information of China (English)

    Chun SONG; Xiu-Qing DUAN; Xi LI; Li-Ou HAN; Ping XU; Chun-Fang SONG; Lian-Hong JIN

    2004-01-01

    To observe the effects of simulated microgravity on beta islet cell culture, we have compared the survival rates and the insulin levels of the isolated rat islet cells cultured at micro- and normal gravity conditions. The survival rates of the cells cultured were determined by acridine orange-propidium iodide double-staining on day 3, 7 and 14. The morphology of the cells was observed by electron microscopy.Insulin levels were measured by radio immuno assays. Our results show that the cell number cultured under the microgravity condition is significantly higher than that under the routine condition (P<0.01). Some tubular structure shown by transmission electron microscopy, possibly for the transport of nutrients, were formed intercellularly in the microgravity cultured group on day 7. There were also abundant secretion particles and mitochondria in the cytoplasm of the cells. Scanning electron microscopy showed that there were holes formed between each islet, possibly connecting with the nutrient transport tubules. The microgravity cultured group also has higher insulin levels in the media as compared with the control group(P<0.01). Our results indicate that microgravity cultivation of islet cells has advantages over the routine culture methods.

  8. An experimental and computational study of solid oxide fuel cell electrodes

    Science.gov (United States)

    Shah, Megna Narendra

    2011-12-01

    Composite nano-LSCF-GDC cathodes were sythesized using an infiltration method achieving polarization resistances as low as 0.2 Ocm 2 at 600°C. Instead of firing both the LSCF and GDC phase in one step, as is done conventionally, the processing of each phase was separate, allowing for individual control to optimize the microstructure of each phase. It was found that firing the GDC scaffold at 1100°C followed by infiltrating LSCF and firing at 800°C yielded optimal performance. The resulting microstructure was a sub-micron scale GDC matrix covered with a nano-scaled LSCF particle network. It was also found that up to 12 vol% LSCF (the highest loading tested), the performance of the cathodes continually improved. A simple model relating the performance of the cathodes to the surface area of the LSCF, electrocatalyst phase showed good agreement with experimental results without the use of fitting parameters at 600°C. Based on the knowledge that the surface area of the LSCF directly impacts the performance, coarsening was then assumed to be the primary degradation mechanism of the cathode. An accelerated testing method was developed, where the cathodes were aged at high temperatures (650--850°C), and impedance measurements were taken at 600°C. This data was fit to a power-law model for coarsening of a 3D particle on a 2D surface. The fit was very good indicating that coarsening was in fact responsible for the decrease in performance. SEM images in the same location after various aging treatments also showed a loss of surface area in the LSCF phase. An activation energy range was found from fitting the power-law model, and predicted degradation over 40,000h was between 39--74%. Finally, a dual infiltration of both LSCF and GDC into a GDC matrix showed decreased degradation, likely because the GDC particles were acting to pin the LSCF and slow the coarsening. Additionally, a phase field model was developed to describe the growth and coarsening of electrocatalyst

  9. Experimental Study on the Inhibitory Effects of Verapamil on the Proliferation of Meningiomas Cells

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian; ZHANG Hongtao; WANG Heping

    2007-01-01

    In order to investigate the effects of verapamil on the proliferation of meningiomas cells in vitro and in vivo, the cultured meningiomas cells were cultured with verapamil at different concentrations for 24 h and the inhibitory effects of verapamii on cell proliferation were observed by MTT method. The meningiomas model was established by implanting the newly removed tumor fragments into the nude mice subcutaneously. The nude mice with tumors were divided into two groups: verapamil-treated group and control group. Tumor volumes were measured and after 12 weeks the tumors were taken out and examined histologically. The expression of proliferating cell nuclear antigen (PCNA) in the tumors was detected by using immunohistochemistry. It was found that verapamil could inhibit the growth of cultured meningiomas cells in a concentration-dependant manner. The inhibitory effect could be observed in the concentration of 1 μmol/L verapamil and the most obvious effects appeared in the concentration of 100 μmol/L. Tumor volume in the verapamiltreated group was obviously smaller than that in the control group (211.40±5.50 vs 163.94±3.62, P<0.01) and theexpression of PCNA was also lower (1.52±0.24 vs 2.86±0.53, P<0.05). Tumor inhibition rate was about 22.45%. It was suggested that verapamil could inhibit the proliferation and growth of meningiomas cells in vitro and in vivo.

  10. Experimental Study on the Cryopreservation of LLC-PK1 Epithelial Cells with Hypoxic UW Solution

    Institute of Scientific and Technical Information of China (English)

    WAN Chidan; WANG Chunyou; LIU Tao; WANG Hongbo; YANG Zhiyong

    2007-01-01

    The effects of oxygen partial pressure on cryopreservation of the cells with organ preservation solution were explored. Hypoxic UW solution was made by purging the UW solution with argon. The pig proximal tubule epithelial cells (LLC-PK1 cells) were cryopreserved in hypoxic UW solution (Ar-UW group) or standard UW solution (UW group) at 4℃ for 48 h. Trypan blue staining and LDH detection were performed to evaluate the injury of the cells. The results showed that the oxygen partial pressure in Ar-UW group was significantly declined from 242±6 mmHg to 83±10 mmHg. After cryopreservation at 4℃ for 48 h, LDH leakage rate and Trypan blue-stained rate in Ar-UW group were (11.3±3.4)% and (10.5±4.7)%, respectively, which were significantly lower than in UW group [(49.5±6.9)% and (47.6±9.3)% respectively, both P<0.01]. It was concluded that lower oxygen partial pressure of UW solution was more beneficial to the cryopreservation of LLC.

  11. Biomass-powered Solid Oxide Fuel Cells: Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  12. The Efficacy of Mesenchymal Stem Cell Transplantation in Caustic Esophagus Injury: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Murat Kantarcioglu

    2014-01-01

    Full Text Available Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10. Group 2, membrane labeled MSCs-treated rats (n: 20. Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET imaging (n: 10. Group 4, sham operated (n: 10. Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

  13. Experimental studies on ultralow frequency pulsed gradient magnetic field inducing apoptosis of cancer cell and inhibiting growth of cancer cell

    Institute of Scientific and Technical Information of China (English)

    曾繁清; 郑从义; 张新晨; 李宗山; 李朝阳; 王川婴; 张新松; 黄晓玲; 张沪生

    2002-01-01

    The morphology characteristics of cell apoptosis of the malignant tumour cells in magnetic field-treated mouse was observed for the first time. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums(ER) expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. Apoptosis of cancer cells was detected by terminal deoxynucleotidyl transferase mediated in situ nick end labeling(TUNEL). It was found that the number of apoptosis cancer cells of the sample treated by the magnetic field is more than that of the control sample. The growth of malignant tumour in mice was inhibited and the ability of immune cell to dissolve cancer cells was improved by ultralow frequency(ULF) pulsed gradient magnetic field; the nuclei DNA contents decreased, indicating that magnetic field can block DNA replication and inhibit mitosis of cancer cells. It was suggested that magnetic field could inhibit the metabolism of cancer cell, lower its malignancy, and restrain its rapid and heteromorphic growth. Since ULF pulsed gradient magnetic field can induce apoptosis of cancer cells and inhibit the growth of malignant tumour, it could be used as a new method to treat cancer.

  14. Experimental study and modelling of degradation phenomena in HTPEM fuel cell stacks for use in CHP systems

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl

    2009-01-01

    Degradation phenomena in HTPEM fuel cells for use in CHP systems were investigated experimentally and by modelling. It was found that the two main degradation mechanisms in HTPEM fuel cells are carbon corrosion and Pt agglomeration. On basis of this conclusion a mechanistic model, describing the...

  15. Experimental study and modeling of degradation phenomena in HTPEM fuel cell stacks for use in CHP systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Andreasen, Søren Juhl; Rasmussen, Peder Lund;

    2009-01-01

    Degradation phenomena in HTPEM fuel cells for use in CHP systems were investigated experimentally and by modeling. It was found that the two main degradation mechanisms in HTPEM fuel cells are carbon corrosion and Pt agglomeration. On basis of this conclusion a mechanistic model, describing the...

  16. Effect of neurotransmitters and bone marrow cells for neuronal regeneration in iatrogenic spinal cord injury: An experimental study

    Directory of Open Access Journals (Sweden)

    John P

    2010-01-01

    Full Text Available Background: Spinal cord trauma is a major health problem with associated physical, social, economic and psychological sequelae. Despite many advances in research and treatment modalities, the pathophysiology of spinal cord injury remains unclear, and morbidity and mortality among these patients remain high. This experimental study investigates the regenerative cell proliferation effects of bone marrow supplemented with neurotransmitters combinations in the regeneration of spinal cord injury Materials and Methods: Ethical Committee Clearance was obtained for animal study. All animal care and procedures were in accordance with the CPCSEA and National Institute of Health guidelines. Thirty Wistar rats with monoplegia following surgical hemitransection of the spinal cord were used for the study. Half of them were randomly selected as the test group and the rest as the control group. Spinal cord injury model of Wistar rats in the test group were treated by infusing a combination of neurotransmitters and bone marrow at the site of injury using a special polythene tube and reservoir for 21 days. In the control group of rats with monoplegia, normal saline was infused at the site of injury for 21 days. The observations are recorded along with results. Results: The monoplegia in the test group of rats recovered significantly (P value < 0.01 with supplementation of the bone marrow cells and neurotransmitters combination. In the control group of rats, there was no recovery. The reward-seeking locomotor test and sensory recovery test confirmed recovery from spinal cord injury in the test group with significance. Conclusions: The neurotransmitters and bone marrow combination was responsible for functional recovery in the test group of rats with experimental spinal cord injury We believe that the combination of neurotransmitters along with bone marrow may be a scope of future research in patients with spinal cord injury.

  17. Experimental study of an endothelial progenitor cell coated stent in transjugular intrahepatic portosystemic shunt

    International Nuclear Information System (INIS)

    Objective: To evaluate the efficacy of a self-expandable metal stent coated with autologous endothelial progenitor cells (EPCs) for prevention of restenosis in transjugular intrahepatic portosystemic shunt (TIPS) in a swine model. Methods: EPCs were coated on the metal stents using fibrin gel before TIPS procedure. TIPS was performed in 15 young adult pigs, using an autologous EPC-seeded stent (treatment group, n=9) or a conventional bare metal stent (control group, n=6). All pigs were sacrificed at 2 weeks after TIPS procedure. Portography was performed immediately before the euthanasia. Gross and microscopic pathological exams and immunohistochemical exams of the TIPS track specimens were performed. Fisher test and t test were used to analyse the data. Results: TIPS was performed successfully in all the 15 swine. On day 14 of follow-up, direct portography and necropsy demonstrated that 5 shunts remained patent, 2 shunts stenosed, and the remaining 2 shunts occluded in the treatment group (n=9); while 5 shunts were occluded and one shunt was stenotic in the control group (n=6). The patency rate was 56% vs 0 (P=0.03) between the two groups. Histological analyses showed a greater pseudo-intimal hyperplasia in the TIPS track of the control group than that of the treatment group (pseudointimal thickness at hepatic vein, hepatic parenchyma and portal vein site was (1.2±0.4), (1.3±0.5), (1.5±0.4) mm vs (1.0±0.6), (0.9±0.5), (1.0±0.4) mm respectively (P<0.05). Conclusion: The EPC-coated metal stent is feasibly constructed in vitro and improves the patency in TIPS in a porcine model. (authors)

  18. Experimental study of cell reversal of a high temperature polymer electrolyte membrane fuel cell caused by H2 starvation

    DEFF Research Database (Denmark)

    Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    regions, decreasing along the flow channel direction, becoming the lowest in the downstream regions. In addition, the CO2 and even the O2 can be detected in the anode exhaust under fuel starvation conditions, confirming the occurring of carbon corrosion and water electrolysis reactions. With lower H2...... stoichiometry and higher current load, the cell voltage decrease rate is higher and the cell reversal is more severe. Higher CO2 concentration in anode exhaust is measured under these conditions, suggesting the degradation is more severe....

  19. OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Hector Colonmer; Prabhu Ganesan; Nalini Subramanian; Dr. Bala Haran; Dr. Ralph E. White; Dr. Branko N. Popov

    2002-09-01

    phase homogeneous model was developed to simulate the performance of the molten carbonate fuel cell cathode and the complete fuel cell. The homogeneous model is based on volume averaging of different variables in the three phases over a small volume element. This approach can be used to model porous electrodes as it represents the real system much better than the conventional agglomerate model. Using the homogeneous model the polarization characteristics of the MCFC cathode and fuel cell were studied under different operating conditions. Both the cathode and the full cell model give good fits to the experimental data.

  20. An experimental study of preventing and treating acute radioactive enteritis with human umbilical cord mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Rui Wang; Wei Yuan; Qiang Zhao; Peng Song; Ji Yue; Shi-De Lin; Ting-Bao Zhao

    2013-01-01

    Objective:To test the curative effect of human umbilical cord-derived mesenchymal stem cells on rat acute radioactive enteritis and thus to provide clinical therapeutic basis for radiation sickness.Methods:Human umbilical cord-derived mesenchymal stem cells were cultivatedin vitro and the model of acute radioactive enteritis of rats was established.Then, the umbilical cord mesenchymal stem cells were injected into the rats via tail vein.Visual and histopathological changes of the experimental rats were observed.Results:After the injection, the rats in the prevention group and treatment group had remarkably better survival status than those in the control group.The histological observations revealed that the former also had better intestinal mucosa structure, more regenerative cells and stronger proliferation activity than the latter.Conclusions:Human umbilical cord-derived mesenchymal stem cells have a definite therapeutic effect on acute radioactive enteritis in rats.

  1. An experimental study on the change of the radiosensitivity of several tumor cell lines and primary cultured gingi cal fibrobrast

    International Nuclear Information System (INIS)

    Radiation sensitivity data was generated for two human cancer cell lines (KB, RPMI 2650) and human primary gingival fibroblast was tested three times using a viable cell number counting with a hemocytometer, MTT (3-[4,5-dimethylthiazol 2-yl]-2,5-dipheny tetrazolium bromide) assay, and LDH (Lactate dehydrogenase) assay. Single irradiation of 2, 4, 6, 10, 15, 20 Gy were applied to the tumor cell lines and the primary cultured gingical fibroblast. The two fractions of 4 Gy an d 10 Gy were separated with a 4 hour time interval. The irradiation was done with 241.5 cGy/min dose rate using 137 Cs MK cell irradiator at room temperature. The obtained results were as followed : 1. There was significantly different viable cell numbers as the amount of radiation dose on the tested cells were cell number counted with a hemocytometer, In fractions, there were more viable cells remaining. 2. Phase-contrast microscopically, radiation-induced morphologic changes were pronounced on the tumor cells, however, almost no differences on the gingival fibroblast. 3. There was significantly different absorbance at 2 Gy on RPMI 2650, 4 Gy on KB and GF in MTT assay. In fractions, the absorbance was significantly higher on KB. 4. The level of extracellular LDH activity in the experimental group was significantly higher in the 2-4 Gy than the control group. 5. The total level of extracellular and intracellular LDH activity was decreased as increased amounts of radiation dose was applied.

  2. Experimental study on MyoD gene induced differentiation of bone marrow mesenchymal stem cells into myoblasts in vitro

    Institute of Scientific and Technical Information of China (English)

    张勇; 邹仲敏; 郭朝华; 周进明; 王劲; 范文辉; 罗成基; 程天民

    2003-01-01

    Objective: To explore the possibility of the transfection of MyoD gene induced bone marrow mesenchymal stem cells (MSCs) to differentiate into myoblasts in vitro.Methods: The eukaryotic expression plasmid vector pIRES2-EGFP-MyoD was transfected into MSCs with lipotransfection method, and the positive cells were selected by G418; The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was identified by sequencing; The reporter gene enhanced green fluorescence protein (EFGP) was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods was used to examine the expressions of MyoD, myogenin, myosin, myoglobin and desmin in the differentiated cells.The ultrastructure changes of the cells before and after transfection were observed with electron microscopy.Results: The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was as same in sequence as that from Genbank; Green fluorescence was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods indicated that MyoD, myogenin, myosin, myoglobin and desmin were expressed in the transfected cells; The transfected cells showed the morphological characteristics of mature cells with filaments in their cytoplasm.Conclusion: MyoD gene can induce cultured MSCs to successfully differentiate into myoblasts, probably providing an experimental foundation for trauma repair.

  3. Experimental study on the 300W class planar type solid oxide fuel cell stack: Investigation for appropriate fuel provision control and the transient capability of the cell performance

    International Nuclear Information System (INIS)

    The present paper reports the experimental study on the dynamic behavior of a solid oxide fuel cell (SOFC). The cell stack consists of planar type cells with standard power output 300W. A Major subject of the present study is characterization of the transient response to the electric current change, assuming load-following operation. The present studies particularly focus on fuel provision control to the load change. Optimized fuel provision improves power generation efficiency. However, the capability of SOFC must be restricted by a few operative parameters. Fuel utilization factor, which is defined as the ratio of the consumed fuel to the supplied fuel is adopted for a reference in the control scheme. The fuel flow rate was regulated to keep the fuel utilization at 50%, 60% and 70% during the current ramping. Lower voltage was observed with the higher fuel utilization, but achieved efficiency was higher. The appropriate mass flow control is required not to violate the voltage transient behavior. Appropriate fuel flow manipulation can contribute to moderate the overshoot on the voltage that may appear to the current change. The overshoot on the voltage response resulted from the gradual temperature behavior in the SOFC stack module.

  4. [Experimental studies on the bioeffects of pulsed ultrasound to the cultured mammalian cell in vitro (author's transl)].

    Science.gov (United States)

    Tsuzaki, T

    1981-12-01

    Cultured cell originated from human amniotic epithelium was sonicated in 2 HMz pulsed ultrasound at various intensities for 30-60 min. Cell suspending medium on sonication was either phosphate buffered saline solution or Eagle's MEM containing calf serum of 20%. On the evaluation of cell growth suppression, relative growth ratios, the growth ratios in sonicated groups to control groups were calculated on 2, 4 and 7 days after sonication. Regression analysis between these relative growth ratios and spatial average-temporal peak intensities on 4 and 7 days after sonication showed linear correlation. Cell growth suppression threshold in the period was 246 or 240 mW/cm2 in spatial peak-temporal average value respectively. On the other hand, intensity measurements in experimental acoustic field by steel ball method showed that spatial peak values were about 2-5 times as large as spatial average values, and beam width in acoustic field (1.7 cm) was a little broader than the inner diameter of the cell suspending tube (1.2 cm). Cell growth suppression disappeared by elevation of viscosity in the cell suspending medium, and reappeared by the prolongation of sonication time or the increment of temporal peak value. PMID:7338663

  5. Experimental Study of Plasmid TGF-β1 DNA Gene Transfer with Lipofectamine into Rabbit Corneal Epithelial Cells In Vitro

    Institute of Scientific and Technical Information of China (English)

    黄琼; 胡燕华; 姜发纲; 陈宏

    2002-01-01

    To investigate whether the TGF-β1 plasmid DNA carried by lipofectamine could be introduced into cultured rabbit corneal epithelial cells, specific expression of the plasmid pMAM TGF-β1in the cultured corneal epithelial cells was studied. Two days after 12 h of transfection of pMAMTGF-β1 mediated by lipofectamine into the cultured corneal epithelial cells, the TGF-β1 protein expression specific for pMAMTGF-β1 in the cells was detected by means of immunohistochemical staining and the positive rate was 23. 37 %. The results suggested that foreign plasmid DNA could be effectively delivered into cultured rabbit corneal epithelial cells by means of lipofectamine, and this will provide a promising method of studying TGF-β1 on the mechanism of physiology and pathology concerned with corneal epithelial cells.

  6. Experimental studies of vircator

    Energy Technology Data Exchange (ETDEWEB)

    Xie Wenkai; Qian Guangdi; Meng Lin; Liu Shenggang [Univ. of Electronic Science and Technology of China, Chengdu, Sichuan (China). Inst. of High Energy Electronics

    1995-11-01

    An experimental device of special high impedance, low beam current vircator is designed by means of the pulse-line electronic beam accelerator at UESTC according to the principle of virtual cathode microwave oscillator. A gradient varying region is linked between the drift tube and the diode in order to reducing the impedance of the diode. A strong pulse longitudinal magnetic field is applied, on the diode-drift region. A special plate-cathode mesh-anode, structure is applied, there are annular grooves with 2. 5mm spaced and 60{degree} on the cathode. Numerical analysis of the experimental system is performed. The operation modes and output power of signal are determined. The output power in X-band is greater than 27Mw, and the efficiency is above 1.0%.

  7. Experimental Study of the Differentiation of Mesenchymal stem Cells (MSCs) after Indirect Co-culture with Ligament Fibroblasts

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Xiong WANG; Huai-Qing CHEN

    2005-01-01

    @@ 1 Introduction Today tissue engineering is known to be a new technique which, based on biological and physical manipulations on cells, aims at the regeneration and reconstruction of tissues or organs in vitro. To construct active ligament tissue by this technique, the following three key points should be considered: choice of cells, scaffold, and the mechanical conditions in vitro. But the studies on ligament cell biology are still in an early stage[1].

  8. Experimental study on the adhesion, migration and three-dimensional growth of Schwann cells on absorbable biological materials

    Institute of Scientific and Technical Information of China (English)

    王光林; 林卫; 杨志明; 裴福兴; 刘雷

    2003-01-01

    Objective: To study the adhesion, migration and three-dimentional growth of Schwann cells on PLA (polylactic acid) nonspinning fibre cloth and polyglycolic/polylactic acid (PLGA) fibres.Methods: Schwann cells/ECM gel solution and PLA nonspinning fibre cloth and PLGA fibres pretreated by collagen, polylysine and ECM were co-cultured. Then the migration and three-dimensional growth of Schwann cells on the fibres were observed under phase contrast microscope and laser scanning confocal microscope.Conclusions: ECM gel can facilitate the adhesion, growth and migration of Schwann cells on the seteroframe. It is a good integrating material for tissue engineering bioartificial nerve.

  9. Experimental study of atorvastatin regulation of HL-60 leukemia cell apoptosis through PI3K/AKT/mTOR

    Institute of Scientific and Technical Information of China (English)

    Lin Mei

    2016-01-01

    Objective:To study the regulatory effect of atorvastatin on HL-60 leukemia cell apoptosis through PI3K/AKT/mTOR. Methods:HL-60 leukemia cells were cultured and processed with different doses of atorvastatin, and then cell apoptosis as well as PI3K, AKT and mTOR expression levels were detected;cells were processed with PI3K, AKT and mTOR inhibitors Wortmannin, Perifosine and Rapamycin, and then cell apoptosis was detected. Results:Different doses of atorvastatin processing could increase the numbers of early apoptotic cells and apoptotic-like necrotic cells, and decrease mRNA contents of PI3K, AKT and mTOR in dose-dependent and time-dependent manner;PI3K, AKT and mTOR inhibitors Wortmannin, Perifosine and Rapamycin processing could increase the numbers of early apoptotic cells and apoptotic-like necrotic cells, and up-regulate the expression of apoptosis genes FasL, Bax, Caspase-3 and Caspase-9. Conclusion:Atorvastatin can induce HL-60 leukemia cell apoptosis through inhibiting PI3K/AKT/mTOR signaling pathway.

  10. Optimization of the output of a solar cell per theoretical and experimental study of the models to one and two exponential

    Directory of Open Access Journals (Sweden)

    Benyoucef B.

    2012-06-01

    Full Text Available The production of electricity based on the conversion of the sunlight by photovoltaic cells containing crystalline silicon is the way most used on the technological and industrial level Consequently, the development of the terrestrial applications for the energy production requires high-output cells and low cost.The aim of our work is to present a comparative study between both theoretical and experimental models of a solar cell based silicon type PHYWE (connecting four cells in series of 80 mm diameter to improve photovoltaic performance.This study led to the determination of the parameters of the cell starting from the current-voltage characteristic, the influence of luminous flow on this characteristic as well as the effect of the incidental photons on the solar cell. We justify the interest to use the model with two exponential for the optimization of the output by underlining the insufficiency of the model to one exponential.

  11. Experimental and theoretical study of hydrodynamic cell lysing of cancer cells in a high-throughput Circular Multi-Channel Microfiltration device

    KAUST Repository

    Ma, W.

    2013-04-01

    Microfiltration is an important microfluidic technique suitable for enrichment and isolation of cells. However, cell lysing could occur due to hydrodynamic damage that may be detrimental for medical diagnostics. Therefore, we conducted a systematic study of hydrodynamic cell lysing in a high-throughput Circular Multi-Channel Microfiltration (CMCM) device integrated with a polycarbonate membrane. HeLa cells (cervical cancer cells) were driven into the CMCM at different flow rates. The viability of the cells in the CMCM was examined by fluorescence microscopy using Acridine Orange (AO)/Ethidium Bromide (EB) as a marker for viable/dead cells. A simple analytical cell viability model was derived and a 3D numerical model was constructed to examine the correlation of between cell lysing and applied shear stress under varying flow rate and Reynolds number. The measured cell viability as a function of the shear stress was consistent with theoretical and numerical predictions when accounting for cell size distribution. © 2013 IEEE.

  12. Electrochemical impedance spectroscopy investigations of a microelectrode behavior in a thin-layer cell: Experimental and theoretical studies.

    Science.gov (United States)

    Gabrielli, C; Keddam, M; Portail, N; Rousseau, P; Takenouti, H; Vivier, V

    2006-10-19

    Electrochemical impedance spectroscopy experiments were performed on a microdisk electrode in a thin-layer cell using a scanning electrochemical microscope for controlling the cell geometry. Experimental data showed that when the thin-layer thickness diminished, an additional low-frequency response appeared. It was ascribed to the radial diffusion of the electroactive species and was strongly dependent on the thin-layer dimensions (both thickness and diameter). Moreover, the numerical simulation of the impedance diagrams by finite element method calculations confirmed this behavior. An equivalent circuit based on a Randles-type circuit was proposed. Thus, the diffusion was described by introducing two electrical elements: one for the spherical diffusion and the other for the radial contribution. A nonlinear Simplex algorithm was used, and this circuit was shown to fit the impedance diagrams with a good accuracy. PMID:17034233

  13. Solid Oxide Fuel Cell Experimental Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Solid Oxide Fuel Cell Experimental Laboratory in Morgantown, WV, gives researchers access to models and simulations that predict how solid oxide fuel cells...

  14. Experimental and analytical studies for the validation of HTR-VGD and primary cell passive decay heat removal. Supplement. Calculations

    International Nuclear Information System (INIS)

    The alternative concept for a modular HTR-reactor design by Siempelkamp, Krefeld, using a prestressed cast iron vessel (VGD) combined with a cast iron/concrete module for the primary cell with integrated passive decay heat removal system was fully qualified with respect to operational and accidental thermal loads. The main emphasis was to confirm and validate the passive decay heat removal capability. An experimental facility (INWA) was designed, instrumented and operated with an appropriate electrical heating system simulating steady-state operational and transient accidental thermal loads. The experiments were accompanied by extensive computations concerning the combination of conductive, radiative and convective energy transport mechanisms in the different components of the VGD/primary cell structures, as well as elastic-plastic stress analyses of the VGD. In addition, a spectrum of potential alternatives for passive energy removed options have been parametrically examined. The experimental data clearly demonstrate that the proposed Siempelkamp-design is able to passively and safely remove the decay heat for operational and accidental conditions without invalidating technological important thermal limits. This also holds in case of failures of both the natural convection system and ultimate heat sink by outside concrete water film cooling. (orig./HP)

  15. Experimental Study of the Differentiation of Mesenchymal stem Cells ( MSCs) after Indirect Co-culture with Ligament Fibroblasts

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionToday tissue engineering is known to be a new technique which, based on biological and physical manipulations on cells, aims at the regeneration and reconstruction of tissues or organs in vitro. To construct active ligament tissue by this technique, the following three key points should be considered: choice of cells, scaffold, and the mechanical conditions in vitro. But the studies on ligament cell biology are still in an early stage~([1]).In this basic research, we aimed mainly at using the ...

  16. The effect of spiritual healing on in vitro tumour cell proliferation and viability--an experimental study

    DEFF Research Database (Denmark)

    Zachariae, R; Højgaard, L; Zachariae, C;

    2005-01-01

    ), and a nonadherent mouse B-lymphoid cell line (HB-94). Analyses of variance (ANOVAs) revealed no significant main or dose-related effects of spiritual healing compared to controls for either of the two cell lines or any of the assays (P-values between 0.09 and 0.96). When comparing healing and control across all......Alternative treatments such as spiritual healing and prayer are increasingly popular, especially among patients with life-threatening diseases such as cancer. According to theories of spiritual healing, this intervention is thought to influence living cells and organisms independently...... of the recipient's conscious awareness of the healer's intention. The aim of this study was to test the hypothesis that spiritual healing will reduce proliferation and viability of two cancer cell lines in vitro. Three controlled experiments were conducted with three different healers and randomised allocation...

  17. Transplantation of autologous bone marrow stem cells via hepatic artery for the treatment of acute hepatic injury: an experimental study in rabbits

    International Nuclear Information System (INIS)

    Objective: To evaluate the transplantation of autologous bone marrow stem cells via hepatic artery in treating acute hepatic injury in experimental rabbit models and to clarify the synergistic effect of hepatocyte growth-promoting factor (pHGF) in stem cell transplantation therapy for liver injury. Methods Acute hepatic injury models were established in 15 experimental rabbits by daily subcutaneous injection of CCl4 olive oil solution with the dose of 0.8 ml/kg for 4 days in succession. The experimental rabbits were randomly and equally divided into three groups: study group A (stem cell transplant, n = 5), study group B (stem cell transplant + pFHG, n = 5), and control group (n = 5). Bone marrow of 5 ml was drawn from the tibia in all rabbits of both study groups, from which bone marrow stem cells were isolated by using density gradient centrifugation, and 5 ml cellular suspension was prepared. Under fluoroscopic guidance, catheterization through the femoral artery was performed and the cellular suspension was infused into the liver via the hepatic artery. Only injection of saline was carried out in the rabbits of control group. For the rabbits in group B, pFHG (2.0 mg/kg) was administered intravenously every other day for 20 days. At 2, 4 and 8 weeks after stem cell transplantation, hepatic function was determined. Eight weeks after the transplantation all the rabbits were sacrificed and the liver specimens were collected and sent for pathological examination. Results After stem cell transplantation, the hepatic function was gradually improved.Eight weeks after the transplantation, the activity of AST, ALT and the content of ALB, TBIL were significantly lower than that before the procedure, while the content of GOLB was markedly increased in all rabbits. In addition, the difference in the above parameters between three groups was statistically significant (P < 0.05). Pathologically, the hepatocyte degeneration and the fiberous hyperplasia in the study groups were

  18. Comparison of cell counting methods in rodent pulmonary toxicity studies: automated and manual protocols and considerations for experimental design.

    Science.gov (United States)

    Zeidler-Erdely, Patti C; Antonini, James M; Meighan, Terence G; Young, Shih-Houng; Eye, Tracy J; Hammer, Mary Ann; Erdely, Aaron

    2016-08-01

    Pulmonary toxicity studies often use bronchoalveolar lavage (BAL) to investigate potential adverse lung responses to a particulate exposure. The BAL cellular fraction is counted, using automated (i.e. Coulter Counter®), flow cytometry or manual (i.e. hemocytometer) methods, to determine inflammatory cell influx. The goal of the study was to compare the different counting methods to determine which is optimal for examining BAL cell influx after exposure by inhalation or intratracheal instillation (ITI) to different particles with varying inherent pulmonary toxicities in both rat and mouse models. General findings indicate that total BAL cell counts using the automated and manual methods tended to agree after inhalation or ITI exposure to particle samples that are relatively nontoxic or at later time points after exposure to a pneumotoxic particle when the response resolves. However, when the initial lung inflammation and cytotoxicity was high after exposure to a pneumotoxic particle, significant differences were observed when comparing cell counts from the automated, flow cytometry and manual methods. When using total BAL cell count for differential calculations from the automated method, depending on the cell diameter size range cutoff, the data suggest that the number of lung polymorphonuclear leukocytes (PMN) varies. Importantly, the automated counts, regardless of the size cutoff, still indicated a greater number of total lung PMN when compared with the manual method, which agreed more closely with flow cytometry. The results suggest that either the manual method or flow cytometry would be better suited for BAL studies where cytotoxicity is an unknown variable. PMID:27251196

  19. Immobilized Kluyveromyces marxianus cells in carboxymethyl cellulose for production of ethanol from cheese whey: experimental and kinetic studies.

    Science.gov (United States)

    Roohina, Fatemeh; Mohammadi, Maedeh; Najafpour, Ghasem D

    2016-09-01

    Cheese whey fermentation to ethanol using immobilized Kluyveromyces marxianus cells was investigated in batch and continuous operation. In batch fermentation, the yeast cells were immobilized in carboxymethyl cellulose (CMC) polymer and also synthesized graft copolymer of CMC with N-vinyl-2-pyrrolidone, denoted as CMC-g-PVP, and the efficiency of the two developed cell entrapped beads for lactose fermentation to ethanol was examined. The yeast cells immobilized in CMC-g-PVP performed slightly better than CMC with ethanol production yields of 0.52 and 0.49 g ethanol/g lactose, respectively. The effect of supplementation of cheese whey with lactose (42, 70, 100 and 150 g/l) on fermentative performance of K. marxianus immobilized in CMC beads was considered and the results were used for kinetic studies. The first order reaction model was suitable to describe the kinetics of substrate utilization and modified Gompertz model was quite successful to predict the ethanol production. For continuous ethanol fermentation, a packed-bed immobilized cell reactor (ICR) was operated at several hydraulic retention times; HRTs of 11, 15 and 30 h. At the HRT of 30 h, the ethanol production yield using CMC beads was 0.49 g/g which implies that 91.07 % of the theoretical yield was achieved. PMID:27126500

  20. Experimental study of hydrogen kinetics from agroindustrial by-product: optimal conditions for production and fuel cell feeding

    Energy Technology Data Exchange (ETDEWEB)

    Perego, P.; Fabiano, B.; Ponzano, G.P.; Palazzi, E. [Univ. Genoa, Inst. of Chemical and Process Engineering ``G.B. Bonino`` (Italy)

    1998-09-01

    One of the best and cleanest systems to produce electric energy is represented by fuel cells, whose natural fuel is hydrogen. In this paper, the production of hydrogen rich biogas is studied. This process contributes to create a system for biomass recovery, which eliminates organic pollutants and produces energy with high efficiency without atmospheric emissions. The study has been based on Escherichia coli and Enterobacter aerogenes strains. The research deals with batch reactors and verification of optimal conditions of hydrogen production. The realization of the optimal working conditions would conduce to the realization of a reactor suitable to feed a stack of the above mentioned fuel cells. In view of industrial applications, some different ways have been considered to greatly enhance the process performance, in terms of rate of hydrogen production, efficiency of hydrogen utilization and/or biosynthesis of valuable subproducts. (orig.)

  1. Experimental study on the self-humidification effect in proton exchange membrane fuel cells containing double gas diffusion backing layer

    International Nuclear Information System (INIS)

    Highlights: • Investigated self-humidification effect of structurally modified GDBLs in PEMFCs. • One conventional and two modified GDLs were prepared. • Structural design of the GDBLs significantly affected self-humidification. • Stacking was found to have negligible effect on self-humidification. • It can be applied readily to self-humidified PEMFCs. - Abstract: Adequate hydration of the membrane is required to ensure high proton conductivity in proton exchange membrane fuel cells (PEMFCs), which, in turn, is required for achieving high cell performances. While external humidifiers are typically used to humidify the supplied air in conventional systems, their use increases the complexity, weight, volume, and parasitic power loss in fuel cell systems, rendering them unviable in some systems, particularly for portable applications. In this study, the structure of a gas diffusion backing layer (GDBL) was modified to enhance the self-humidification effect in PEMFCs. Three types of GDLs were prepared for the experiments: a conventional GDL (GDL-A with uniform single GDBL) and two modified GDLs (GDL-A′B with uniform double GDBL and GDL-A′C with heterogeneous double GDBLs). In order to evaluate the effect of stacking and structural design on the self-humidification characteristics, some characteristics of the GDLs such as contact angle, resistance, and vapor permeation rate were measured. The electrochemical performances of the fuel cells were also measured at various relative humidity (RH) and stoichiometric ratio (SR) conditions. The results showed that stacking had a negligible effect, whereas the structural design of the GDBL had a significant effect on self-humidification. The self-humidification effect and the cell performance were improved significantly in the structurally modified GDBL. In addition, considering the actual field conditions and the results of the present study, it was concluded that the structural modifications made to the GDBL would

  2. Experimental study of liquid-immersion III–V multi-junction solar cells with dimethyl silicon oil under high concentrations

    International Nuclear Information System (INIS)

    Highlights: • Electrical performance of MJ solar cells immersed by silicon oil was studied under 500×. • Theoretical cell photocurrent losses caused by silicon oil absorption were estimated. • Cell performance changes operated in silicon oil (1.0–30.0 mm) were analyzed. • Critical silicon oil thickness on top of MJ solar cells was estimated to be 6.3 mm. - Abstract: In order to better apply direct liquid-immersion cooling (LIC) method in temperature control of solar cells in high concentrating photovoltaic (CPV) systems, electrical characteristics of GaInP/GaInAs/Ge triple-junction solar cells immersed in dimethyl silicon oil of 1.0–30.0 mm thickness were studied experimentally under 500 suns and 25 °C. Theoretical photocurrent losses caused by spectrum transmittance decrease from spectral absorption of silicon oil were estimated for three series sub-cells, and an in-depth analysis of the electrical performances changes of the operated cell in silicon oil was performed. Compared with cell performances without liquid-immersion, the conversion efficiency and the maximum output power of the immersed solar cell in silicon oil of 1.0 mm thickness has increased from 39.567% and 19.556 W to 40.572% and 20.083 W respectively. However, the cell electrical performances decrease with increasing silicon oil thickness in the range of 1.0–30.0 mm, and the efficiency and the maximum output power of the cell have become less than those without liquid-immersion when the silicon oil thickness exceeds 6.3 mm

  3. Comparative experimental studies into radioimmunoscintigraphy using radioactive antibodies in animals with HeLa cell carcinomas and Yoshida sarcomas

    International Nuclear Information System (INIS)

    TPA-positive and TPA-negative tumour-bearing animal systems (HeLa cell carcinomas in RNU rats and Yoshida sarcomas in Wistar rats) were examined to show that the method of scanning can well be used to visualise tumour tissue. In this connection, further attempts were made to shed light on the specifity of immunoscintigraphy in the search for tumour tissue. 125-Iodine-anti-TPA was found to be a specific carcinoma-seeking substance. The amount of antibodies accumulating in the tumour was multiplied by previous intravenous treatment of test animals with unspecific immunoglobulin. In control studies using 125-iodine-immunoglobulin the site of the carcinomatous tissue could not be determined with sufficient diagnostic accuracy. It was found that the discriminating power of radioimmunoscintigraphy using 125-iodine-anti-TPA is quite unrelated to an increased circulation in the proliferating carcinomatous tissue. For the detection of TPA in HeLa cell carcinomas anti-TPA PAP stains were prepared. Radionuclide studies using 125-iodine-anti-TPA were also useful in the visualisation of the Yoshida sarcoma, even though this scores negative on TPA. Here, the amounts of radioactivity accumulating in the tumour were smaller than with the HeLa cell carcinoma. Moreover, peak levels were measured after no less than one day, as compared to the five days required for HeLa cell tumours to reach maximum levels. This finding would appear to provide presumptive evidence that there are other, unspecific mechanisms of tumour selectivity. (orig/MG)

  4. An experimental study of Au removal from solution by non-metabolizing bacterial cells and their exudates

    Science.gov (United States)

    Kenney, Janice P. L.; Song, Zhen; Bunker, Bruce A.; Fein, Jeremy B.

    2012-06-01

    In this study, we examine the initial interactions between aqueous Au(III)-hydroxide-chloride aqueous complexes and bacteria by measuring the effects of non-metabolizing cells on the speciation and distribution of Au. We conducted batch Au(III) removal experiments, measuring the kinetics and pH dependence of Au removal, and tracking valence state transformations and binding environments using XANES spectroscopy. These experiments were conducted using non-metabolizing cells of Bacillus subtilis or Pseudomonas putida suspended in a 5 ppm Au(III)-(hydroxide)-chloride starting solution of 0.1 M NaClO4 to buffer ionic strength. Both bacterial species removed greater than 85% of the Au from solution after 2 h of exposure time below approximately pH 5. Above pH 5, the extent of Au removed from solution decreased with increasing pH, with less than approximately 10% removal of Au from solution above pH 7.5. Kinetics experiments indicated that the Au removal with both bacterial species was rapid at pH 3, and slowed with increasing pH. Reversibility experiments demonstrated that (1) once the Au was removed from solution, adjusting 35 the pH alone did not remobilize the Au into solution and (2) the presence of cysteine in solution in the reversibility experiments caused Au to desorb, suggesting that the Au was not internalized within the bacterial cells. Our results suggest that Au removal occurs as a two-step pH-dependent adsorption reduction process. The speciation of the aqueous Au and the bacterial surface appears to control the rate of Au removal from solution. Under low pH conditions, the cell walls are only weakly negatively charged and aqueous Au complexes adsorb readily and rapidly. With increasing pH, the cell wall becomes more negatively charged, slowing adsorption significantly. The XANES data demonstrate that the reduction of Au(III) by bacterial exudates is slower and less extensive than the reduction observed in the bacteria-bearing systems, and we conclude that

  5. Experimental studies of electron capture

    International Nuclear Information System (INIS)

    This thesis discusses the main results of recent experimental studies of electron capture in asymmetric collisions. Most of the results have been published, but the thesis also contains yet unpublished data, or data presented only in unrefereed conference proceedings. The thesis aims at giving a coherent discussion of the understanding of the experimental results, based first on simple qualitative considerations and subsequently on quantitative comparisons with the best theoretical calculations currently available. (Auth.)

  6. Experimental study on the effect and mechanism of action of active immunization with elemene combo-tumor cell vaccine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Elemene is a new anticancer drug isolated from a Chinese traditional medicine Curcuma aromatica. In previous work, we discovered that tumor cell vaccine (TCV) treated with oleum Curcuma aromatica or elemene could induce significant immunoprophylactic effect against a variety of aminal tumor strains and the method of preparation of elemene combo-TCV(EC-TCV) already got China's inventive patent. In this paper we further studied the active immunotherapeutic effect and the possible cellular/molecular mechanisms of EC-TCV immunization. The results were as follows:(1) EC-TCV immunization showed significant therapeutic effects (P<0.05) against murine Ca761 syngeneic mammary carcinoma (H-2k) and HCa-F allogeneic hepatic carcinoma (H-2-) models; (2) The spleen cells of Hca-F EC-TCV immunized mice displayed higher cytotoxicity and IL-12 level while the secretion of IL-10 was decreased (P<0.05); (3) Similar to heat shock, elemene(E), mitomycin C(MMC) and glutaraldehyde (G) could act alone as stressor, and induce significant changes of the expression of membrane heat shock proteins(HSP70 or/and HSP90) on L615 leukemia and HCa-F hepatoma cells and the EC-TCVs (E+MMC+G treated in combination) showed the highest level of membrane HSPs expression (P<0.05 or P<0.01 );(4) The HSP70-peptide complex isolated from HCa-F EC-TCV through ADP-agarose affinity chromatographic system could induce active immunoprotection against lethal dose challenge of HCa-F hepatic cancer cell but could not protect against the cross challenge of lethal dose of L615 leukemia. The results indicated that the immunoprotective effect of EC-TCV was in some extent tumor-specific, MHC-nonrestricted, and HSPs might play an important role in its molecular mechanisms.

  7. EXPERIMENTAL STUDY OF THE DIFFERENTIATION HPV16 SUBGENES-IMMORTALIZED HUMAN ENDOCERVICAL CELLS INDUCED BY ALL-TRANS-RETINOIC ACID

    Institute of Scientific and Technical Information of China (English)

    LI Yi-ming; ZHAO Yong; LIN Xiao

    2005-01-01

    Objective: To investigate the differentiation-inducing effects of all-trans-retinoic (ATRA) to HPV16 subgenesimmortalized human endocervical cells (H8 cell) in vitro. Methods: HPV16 subgenes-immortalized human endocervical cells(H8 cells) were cultured in vitro. After treated with ATRA, the proliferation of immortalized human endocervical cells was measured by MTT assay; morphological changes were observed using M and TEM; cell cycle was analyzed by FCM;expression of Ki67 was tested using immunocytochemistry and the activity of telomerase was tested using PCR-ELISA.Results: ATRA could inhibit proliferation of H8 cells significantly and induce their morphodifferentiation. According to FCM, H8 cells accumulated in G1 phase and expression of Ki67 and activity of telomerase reduced significantly after treatment with ATRA. Conclusion: ATRA could induce the differentiation of H8 cell line obviously, which might be achieved by inhibiting proliferation, blocking cell cycle, and reducing activity of telomerase.

  8. Semantic-Oriented Sentiment Classification for Chinese Product Reviews: An Experimental Study of Book and Cell Phone Reviews

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Sentiment classification is an automatic opinion classification method to classify the product reviews on web into positive or negative opinions to help consumers or sellers to understand the opinions and evaluations from existing customers. Semantic-oriented approach is one of the recent developments in sentiment classification. Up to now, most research of sentiment classification is on English reviews,and little work has been done on Chinese reviews using sentiment classification. The detailed techniques used in English review cannot be applied directly to Chinese reviews due to the different characteristics between these two languages. This study modified and improved the semantic-oriented approach to a 6-step process for Chinese review, focusing on the modification and improvement on the text segmentation and reference words pairs (RWPs) identification. Two experiments were conducted on book reviews and cell phone reviews. The results show that the performances of the proposed approach are comparable to those of the existing English reviews classification studies.

  9. Effect of solvent and additives on the open-circuit voltage of ZnO-based dye-sensitized solar cells: a combined theoretical and experimental study.

    Science.gov (United States)

    Le Bahers, Tangui; Labat, Frédéric; Pauporté, Thierry; Ciofini, Ilaria

    2010-11-28

    We have investigated the role of electrolyte composition, in terms of solvent and additive, on the open-circuit voltage (V(oc)) of ZnO-based dye-sensitized solar cells (DSSCs) using a combined experimental and theoretical approach. Calculations based on density functional theory (DFT) have been performed in order to describe the geometries and adsorption energies of various adsorbed solvents (nitromethane, acetonitrile and dimethylformamide) and p-tert-butylpyridine (TBP) (modeled by methylpyridine) on the ZnO (100) surface using a periodic approach. The densities of states (DOS) have been calculated and the energy position of the conduction band edge (CBE) has been evaluated for the different molecules adsorbed. The effect of the electrolyte composition on the standard redox potential of the iodide/triiodide redox couple has been experimentally determined. These two data values (CBE and standard redox potential) allowed us to determine the dependence of V(oc) on the electrolyte composition. The variations determined using this method were in good agreement with the measured V(oc) for cells made of electrodeposited ZnO films sensitized using D149 (indoline) dye. As in the case of TiO(2)-based cells, a correlation of V(oc) with the donor number of the adsorbed species was found. The present study clearly points out that both the CBE energy and the redox potential variation are important for explaining the experimentally observed changes in the V(oc) of DSSCs. PMID:20949189

  10. In vitro and in vivo studies on antitumor effects of gossypol on human stomach adenocarcinoma (AGS) cell line and MNNG induced experimental gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gunassekaran, G.R., E-mail: gunassekaran@yahoo.co.in [Department of Medical Biochemistry, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, Tamil Nadu (India); Kalpana Deepa Priya, D.; Gayathri, R.; Sakthisekaran, D. [Department of Medical Biochemistry, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, Tamil Nadu (India)

    2011-08-12

    Highlights: {yields} Gossypol is a well known polyphenolic compound used for anticancer studies but we are the first to report that gossypol has antitumor effect on MNNG induced gastric cancer in experimental animal models. {yields} Our study shows that gossypol inhibits the proliferation of AGS (human gastric adenocarcinoma) cell line. {yields} In animal models, gossypol extends the survival of cancer bearing animals and also protects the cells from carcinogenic effect. {yields} So we suggest that gossypol would be a potential chemotherapeutic and chemopreventive agent for gastric cancer. -- Abstract: The present study has evaluated the chemopreventive effects of gossypol on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and on human gastric adenocarcinoma (AGS) cell line. Gossypol, C{sub 30}H{sub 30}O{sub 8}, is a polyphenolic compound that has anti proliferative effect and induces apoptosis in various cancer cells. The aim of this work was to delineate in vivo and in vitro anti-initiating mechanisms of orally administered gossypol in target (stomach) tissues and in human gastric adenocarcinoma (AGS) cell line. In vitro results prove that gossypol has potent cytotoxic effect and inhibit the proliferation of adenocarcinoma (AGS) cell line. In vivo results prove gossypol to be successful in prolonging the survival of MNNG induced cancer bearing animals and in delaying the onset of tumor in animals administrated with gossypol and MNNG simultaneously. Examination of the target (stomach) tissues in sacrificed experimental animals shows that administration of gossypol significantly reduces the level of tumor marker enzyme (carcino embryonic antigen) and pepsin. The level of Nucleic acid contents (DNA and RNA) significantly reduces, and the membrane damage of glycoprotein subsides, in the target tissues of cancer bearing animals, with the administration of gossypol. These data suggest that gossypol may create a beneficial effect in

  11. Diphtheria Toxin/Human B-Cell Activating Factor Fusion Protein Kills Human Acute Lymphoblastic Leukemia BALL-1 Cells: An Experimental Study

    Institute of Scientific and Technical Information of China (English)

    Xin-pu Gao; Zheng-min Liu; Yu-lian Jiao; Bin Cui; Yue-ting Zhu; Jie Zhang; Lai-cheng Wang; Yue-ran Zhao

    2012-01-01

    Objective:This study aimed to express a fusion protein of diphtheria toxin and human B ceil-activating factor (DT388sBAFF) in Escherichia coli (E.coli) and investigate its activity in human B-lineage acute lymphoblastic leukemia 1 cells (BALL-1).Methods:A fragment of DT388sBAFF fusion gene was separated from plasmid pUC57-DT388sBAFF digested with Nde Ⅰ and Xho Ⅰ,and inserted into the expression vector pcold Ⅱ digested with the same enzymes.Recombinants were screened by the colony polymerase chain reaction (PCR) and restriction map.The recombinant expression vector was transformed into BL21 and its expression was induced by isopropyl β-D-1-thiogalactopyranoside (IPTG).The recombinant protein was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot,and then purified by Ni2+-NTA affinity chromatography.The expression level of B cell-activating factor receptor (BAFF-R) on BALL-1 cells was assessed by real-time PCR.The receptor binding capacity of recombinant protein was determined by cell fluorescent assay.The specific cytotoxicity of recombinant protein on BALL-1 cells was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay.Results:The expression level of recombinant protein was 50% of total bacterial proteins in E.coli,and the recombinant protein could bind to BAFF-R-positive BALL-1 cells and thereby produce a cytotoxic effect on the cells.Conclusion:The fusion protein expression vector DT388sBAFF was successfully constructed and the recombinant protein with selective cytotoxicity against BALL-1 cells was obtained,providing foundation for further study of the therapy of human B-lineage acute lymphoblastic leukemia.

  12. EXPERIMENTAL STUDY ON THERMOCAPILLARY CONVECTION

    Institute of Scientific and Technical Information of China (English)

    束继祖

    2003-01-01

    In the present paper, the experimental studies on thermocapillary convection are reviewed. The author's interest is mainly focused on the onset of oscillatory thermocapillary convection,the features of oscillatory flow pattern, and the critical Marangoni number related with temperature and free surface oscillation. The coordinated measurement in a microgravity environment of a drop shaft is also addressed.

  13. Further Studies on Antioxidant Potential and Protection of Pancreatic β-Cells by Embelia ribes in Experimental Diabetes

    Directory of Open Access Journals (Sweden)

    Uma Bhandari

    2007-01-01

    Full Text Available This study was designed to examine the antioxidant defense by ethanolic extract of Embelia ribes on streptozotocin-(40 mg/kg, intravenously, single-injection induced diabetes in Wistar rats. Forty days of oral feeding the extract (100 mg/kg and 200 mg/kg to diabetic rats resulted in significant (P<.01 decrease in blood glucose, blood glycosylated haemoglobin, serum lactate dehydrogenase, creatine kinase, and increase in blood glutathione levels as compared to pathogenic diabetic rats. Further, the extract also significantly (P<.01 decreased the pancreatic thiobarbituric acid-reactive substances (TBARS levels and significantly (P<.01 increased the superoxide dismutase, catalase, and glutathione levels as compared to above levels in pancreatic tissue of pathogenic diabetic rats. The islets were shrunken in diabetic rats in comparison to normal rats. In the drug-treated diabetic rats, there was expansion of islets. The results of test drug were comparable to gliclazide (25 mg/kg, daily, a standard antihyperglycemic agent. The study concludes that Embelia ribes enhances the antioxidant defense against reactive oxygen species produced under hyperglycemic condition and this protects β-cells against loss, and exhibit antidiabetic property.

  14. Technological study of experimental proton exchange polymer membrane fuel cells; Estudo tecnologico de celulas a combustivel experimentais a membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Thais Aranha de Barros

    2004-07-01

    Experimental studies to achieve an optimized behavior of a unit PEM-fuel cell with an active area of 25cm{sup 2} were carried out. Polarization curves, surface response methodology and regression methodology were used for the analysis. The different methodologies identified the interactions between the parameters that were studied. These parameters were, humidifying temperature, fuel cell operating temperature and the flows of hydrogen and oxygen. MEAs were produced by the spray and hot pressing hybrid method, developed at IPEN. The studies were done with these MEAs and equivalent commercial ones. The MEAs producing method used induced an important variation on the quantity of platinum in the electrodes. This fact has showed to have a great influence in the results. The optimized values were: oxygen flow from 30 to 35% of consume (70 to 65% of excess), fuel cell operating temperature from 60 to 62 deg C and 0.41 mg of platinum in the electrodes. The hydrogen flows and the humidifying temperature have not showed a major influence in the fuel cell behavior, in the studied variable range. (author)

  15. An experimental and simulation study of novel channel designs for open-cathode high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Thomas, Sobi; Bates, Alex; Park, Sam;

    2016-01-01

    for oxidant and coolant supply, which reduces the overall size of the stack, power losses, and results in a lower system volume. In the present study, we present unique designs for an open-cathode system which offers uniform temperature distribution with a minimum temperature gradient and a uniform flow...... distribution through each cell. Design studies were carried out to increase power density. An experimental and simulation approach was carried out to design the novel open-cathode system. Two unique parallel serpentine flow designs were developed to yield a low pressure drop and uniform flow distribution, one......A minimum balance of plant (BOP) is desired for an open-cathode high temperature polymer electrolyte membrane (HTPEM) fuel cell to ensure low parasitic losses and a compact design. The advantage of an open-cathode system is the elimination of the coolant plate and incorporation of a blower...

  16. Experimental Study on Hysucat Vessels

    Institute of Scientific and Technical Information of China (English)

    M.S.Seif; M.Askari

    2004-01-01

    The paper contains the results of an experimental study on a planing catamaran. The aim of this study is resistance reduction with application of foils. Experiments are performed in different conditions and the results are compared with each other. The foils are used in different configurations and it is concluded that unsuitable design may result in larger resistance. But, it is also shown that, for a good design, the resistance may be reduced considerably.

  17. Theoretical and Experimental Investigation of Thermodynamics and Kinetics of Thiol-Michael Addition Reactions: A Case Study of Reversible Fluorescent Probes for Glutathione Imaging in Single Cells.

    Science.gov (United States)

    Chen, Jianwei; Jiang, Xiqian; Carroll, Shaina L; Huang, Jia; Wang, Jin

    2015-12-18

    Density functional theory (DFT) was applied to study the thermodynamics and kinetics of reversible thiol-Michael addition reactions. M06-2X/6-31G(d) with the SMD solvation model can reliably predict the Gibbs free energy changes (ΔG) of thiol-Michael addition reactions with an error of less than 1 kcal·mol(-1) compared with the experimental benchmarks. Taking advantage of this computational model, the first reversible reaction-based fluorescent probe was developed that can monitor the changes in glutathione levels in single living cells.

  18. The Experimental Study of Constructing Tissue Engineered Bone by Compounding Zinc-sintered Bovine Cancellous Bone with Marrow Stromal Cells

    Institute of Scientific and Technical Information of China (English)

    ZHENG Qi-xin; HAO Jie; GUO Xiao-dong; LIU Su-nan; Wu Yong-chao; YAN Yu-hua

    2004-01-01

    To study the osteogenic ability of tissue-engineered bone constructed by compounding zinc-sin-tered bovine cancellous bone with rabbit marrow stromal cells ( MSCs ) in vivo, the zinc- sintered bovine cancellousbone of beta-tricalcium phosphate (TCP) type was prepared by sintering the fresh calf cancellous bone twice andthen loading it with zinc-ion. The rabbit MSCs were cultured, induced and seeded onto the zinc- sintered bovine can-cellous bones. The tissue-engineered bones were then implanted into the rabbits' bock muscles. The newly formedbone tissues were observed by histological methods and the areas of new osseous tissues were measured at the end ofthe 4 th and 8 th week. The zinc-sintered bovine cancellous bones alone were implanted on the other side as control.The osteogenic activity of MSCs was identified by alkaline phosphatase (ALP) staining and calcification nod chi-nalizarin staining. At the end of 4th week, a small amount of new bone tissues was observed. At the end of 8thweek, there were many newly formed bone mature tissues. Moreover, the area of the latter was significantly largerthan that of the former( P<0.01), while in the control group there was no new bone formation. The tissue-engi-neered bone, which was constructed by combining zinc-sintered bovine cancellous bone with MSCs, has satisfactoryosteogenic capabilities in vivo.

  19. Composing Experimental Environment of PRIDE Argon cell

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Seonho; Jang, Yongkuk; Cho, Il Je [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In PRIDE depleted Uranium feed material and a depleted Uranium mixed with some surrogate material are used for performing engineering scale Pyroprocessing. PRIDE has to maintain inert atmosphere because of the characteristic of Electrolytic Reduction technology, Electro refining technology, Electrowinning technology. The impurity concentration of the Argon cell has to be under 50 ppm(Oxygen, moisture). Atmospheric pressure changes and temperature changes can affect the Argon cell's impurity concentration. In this paper, how to compose the Argon cell impurity concentration under 50 ppm to make the exact optimal experimental environment(Oxygen, moisture) will be introduced. Composing the exact optimal experimental environment by supplying Argon gas have been introduced in this paper. Continuously supplying Argon gas which is heavier than the Oxygen through the bottom of the Argon cell the oxygen eventually discharged through the high vent fan and lower the impurity concentration of Oxygen.

  20. THE EXPERIMENTAL STUDY ON THE CELL APOPTOSIS AND EXPRESSION OF BCL-2 PROTEIN IN INTRACEREBRAL HEMORRHAGE IN MODEL OF RATS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Intra-cerebral hemorrhage is a common clinicaldisease,with a high mortality and morbidity.So itis one of the clinical hot topics.It has been foundinrecent years that there is a close relationship bet weenthe cell apoptosis and the course or prognosis of in-tra-cerebral hemorrhage.Bcl-2,as the apoptosis-adjusted gene,plays ani mportant role in the courseof cell apoptosis,but the mechanis min the cell ap-optosis in intra-cerebral hemorrhage remains un-clear.In this experi ment,with the model buildingof the in...

  1. Experimental Study of 103Pd Stent Affecting Dynamic Equilibrium Between Proliferation and Apoptosis of Vascular Smooth Muscle Cells

    Institute of Scientific and Technical Information of China (English)

    Liu Yingmei; Fu Yuewu; Wei Yulin; Wu Wei

    2006-01-01

    Objectives By observing γ radioactive 103Pd stent affecting the proliferation and apoptosis of vascular smooth muscle cells (VSMCs) to explore the mechanism of radioactive stent preventing in-stent restenosis. Methods Fifty male New Zealand rabbits were randomized into stent group and 103Pd stent group. Control group was set up. The materials were harvested on 3, 7, 14, 28, 56 days after operation and the following investigations were carried out, including pathomorphology, immunohistochemistry, apoptosis (TUNEL) and in situs hybridization studies. Results ①The severity of the stenosis in 103Pd stent group was less than that of stent group.It was the most obvious on 56th day (P < 0.01).②The expression of PCNA of 103Pd stent group was lower than that of stent group on 3 to 28 days. It was the most obvious on 7th day, 16.35%±0.79% vs 24.36%±0.55% (P< 0.01 ). ③TUNEL method showed that the 103Pd stent group had much more apoptosis of VSMCs than that of stent group. The highest rate of apoptosis appeared on day 7, 14.72%±0.53% vs 12.42%±1.13% (P<0.01). ④ By calculating the ratio of PCNA/apoptosis (P:A), a much lower ratio was seen in 103Pd-stent group than that of stent group at 3 to 28 days. There was significant statistic difference between two groups (P<0.05). ⑤For bcl-2/bax ratio, the result in 103Pd-stent group was lower than that of stent group at 3 to 28 days. It had significant statistic difference (P < 0.05). Conclusions γ radioactive stent can inhibit the proliferation and accelerate apoptosis of injured media VSMCs. Also it can decrease the ratio of proliferation to apoptosis and relieve the severity of restenosis.

  2. Illumination angle and layer thickness influence on the photo current generation in organic solar cells: A combined simulative and experimental study

    Directory of Open Access Journals (Sweden)

    Jan Mescher

    2015-07-01

    Full Text Available In most future organic photovoltaic applications, such as fixed roof installations, facade or clothing integration, the solar cells will face the sun under varying angles. By a combined simulative and experimental study, we investigate the mutual interdependencies of the angle of light incidence, the absorber layer thickness and the photon harvesting efficiency within a typical organic photovoltaic device. For thin absorber layers, we find a steady decrease of the effective photocurrent towards increasing angles. For 90-140 nm thick absorber layers, however, we observe an effective photocurrent enhancement, exhibiting a maximum yield at angles of incidence of about 50°. Both effects mainly originate from the angle-dependent spatial broadening of the optical interference pattern inside the solar cell and a shift of the absorption maximum away from the metal electrode.

  3. Illumination angle and layer thickness influence on the photo current generation in organic solar cells: A combined simulative and experimental study

    International Nuclear Information System (INIS)

    In most future organic photovoltaic applications, such as fixed roof installations, facade or clothing integration, the solar cells will face the sun under varying angles. By a combined simulative and experimental study, we investigate the mutual interdependencies of the angle of light incidence, the absorber layer thickness and the photon harvesting efficiency within a typical organic photovoltaic device. For thin absorber layers, we find a steady decrease of the effective photocurrent towards increasing angles. For 90-140 nm thick absorber layers, however, we observe an effective photocurrent enhancement, exhibiting a maximum yield at angles of incidence of about 50°. Both effects mainly originate from the angle-dependent spatial broadening of the optical interference pattern inside the solar cell and a shift of the absorption maximum away from the metal electrode

  4. Experimental study of MSCs promoting haploid hematopoietic stem cell transplantation in treatment for mice with acute radiation syndrome

    International Nuclear Information System (INIS)

    Objective: To investigate the mechanism of mesenchymal stem cells in enhancing the effects of haploid matched bone marrow cells transplantation in mice with acute radiation syndrome (ARS). Methods: The survival of mice infused with different levels of MSCs and bone marrow cells after 8 Gy TBI were examined. BALB/c female mice irradiated with 8 Gy of 60Co γ-rays were randomly divided into two groups, MSCs group, infused with MSCs of female CB6F1 mice labeled with cm-DiI and bone marrow monocytes of male CB6F1, Control group, only infused with bone marrow monocytes. Peripheral blood counts, T-lymphocyte subpopulation of peripheral, blood cells, the sty-gene chimerism of bone marrow of the receiptors, the distribution of MSCs in the receiptors, the occurrence time of cGVHD, pathologic variety of medulla were observed. Results: MSCs improved the survival of mice after 8 TBI, but 1.5 x 108/kg of MSCs increased the mortality of irradiated mice. In comparison with the control group, leukocytes and plastocytes recovered rapidly in MSCs group. Megacaryocytes in sternum marrows grew lastly in MSC group. The percent of CD3 and CD4 positive cells in the MSCs group were higher than those in control post-transplantation. The sty-gene chimerism of bone marrow of the receiptors was higher in the MSCs group than that in the control at 30 d. The MSCs were distributed in intestine, thymus, bone marrow, liver, heart of the receiptors at 30 d. The cGVHD occurrence was 30 d later in MSCs group than that of the control. Conclusions: MSCs could improve stem cell engraftment, enhance T-lymphocyte and plastocytes recovery, delay occurrence of cGVHD, repair injured organs and increase survivals. It is indicated that MSCs can enhance the treatment effects of haploid hematopoietic stem cells transplant for ARS. (authors)

  5. The Experimental Study of the Performance of Nano-Thin Polyelectrolyte Shell for Dental Pulp Stem Cells Immobilization.

    Science.gov (United States)

    Grzeczkowicz, A; Granicka, L H; Maciejewska, I; Strawski, M; Szklarczyk, M; Borkowska, M

    2015-12-01

    Carious is the most frequent disease of mineralized dental tissues which might result in dental pulp inflammation and mortality. In such cases an endodontic treatment is the only option to prolong tooth functioning in the oral cavity; however, in the cases of severe pulpitis, especially when complicated with periodontal tissue inflammation, the endodontic treatment might not be enough to protect against tooth loss. Thus, keeping the dental pulp viable and/or possibility of the reconstruction of a viable dental pulp complex, appears to become a critical factor for carious and/or pulp inflammation treatment. The nowadays technologies, which allow handling dental pulp stem cells (DPSC), seem to bring us closer to the usage of dental stem cells for tooth tissues reconstruction. Thus, DPSC immobilized within nano-thin polymeric shells, allowing for a diffusion of produced factors and separation from bacteria, may be considered as a cover system supporting technology of dental pulp reconstruction. The DPSC were immobilized using a layer-by-layer technique within nano-thin polymeric shells constructed and modified by nanostructure involvement to ensure the layers stability and integrity as well as separation from bacterial cells. The cytotoxity of the material used for membrane production was assessed on the model of adherent cells. The performance of DPSC nano-coating was assessed in vitro. Membrane coatings showed no cytotoxicity on the immobilized cells. The presence of coating shell was confirmed with flow cytometry, atomic force microscopy and visualized with fluorescent microscopy. The transfer of immobilized DPSC within the membrane system ensuring cells integrity, viability and protection from bacteria should be considered as an alternative method for dental tissues transportation and regeneration. PMID:26682375

  6. Cell Culture Microfluidic Biochips: Experimental Throughput Maximization

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan;

    2011-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory, integrating all necessary functionalities on-chip in order to perform biochemical applications. Researchers have started to propose computer-aided design tools for the synthesis of such biochips. Our foc...... metaheuristic for experimental design generation for the cell culture microfluidic biochips, and we have evaluated our approach using multiple experimental setups....... in this paper is on the optimization of how a biochemical application is performed on a biochip. In this paper, we consider cell culture biochips, where several cell colonies are exposed to soluble compounds and monitored in real-time to determine the right combination of factors that leads to the desired...

  7. Experimental study on inhibitory effect of bridgy duct of hepatic artery on apoptosis of liver and bile duct cells

    Institute of Scientific and Technical Information of China (English)

    Hongwei Lu; Yiming Li; Hong Ji; Jinkai Xu

    2006-01-01

    Objective: To investigate whether the method of bridgy duct established between the recipient's spleen artery and the donor's gastroduodenal artery could inhibit the apoptosis of liver and bile duct cells caused by hepatic artery ischemia.Methods: Twenty-four mongrel dogs from Xi'an area were used to establish simplified models of dog orthotopic liver transplantation and divided into three groups randomly: HAI group (hepatic artery ischemia group),BBB group (bypassing the blood by a bridgy duct) and control group. After cold perfusion, The samples were collected from liver and bile duct in each group at different time and fixed in glutaraldehyde and 4% polyformaldehyde respectively. At last, the apoptosis of liver and bile duct cells were observed and the apoptotic indexes were calculated. Results: Two hours after cold perfusion, apoptotic phenomenon was common in HAI group, rare in BBB group, while no apoptotic phenomenon was observed in control group. TUNEL staining showed that there was no significant difference in apoptotic index among the three groups immediately after cold perfusion. However, with time going, the apoptotic cells were increased in three groups, and the difference in apoptotic index was significant among three groups (P < 0.01 ). Conclusion: Bridgy duct of hepatic artery can inhibit the apoptosis of liver and bile duct cells caused by HAI significantly.

  8. Experimental study of vortex diffusers

    Energy Technology Data Exchange (ETDEWEB)

    Shakerin, S.; Miller, P.L. [National Renewable Energy Lab., Golden, CO (United States)

    1995-11-01

    This report documents experimental research performed on vortex diffusers used in ventilation and air-conditioning systems. The main objectives of the research were (1) to study the flow characteristics of isothermal jets issuing from vortex diffusers, (2) to compare the vortex diffuser`s performance with that of a conventional diffuser, and (3) to prepare a report that disseminates the results to the designers of ventilation and air-conditioning systems. The researchers considered three diffusers: a conventional round ceiling diffuser and two different styles of vortex diffusers. Overall, the vortex diffusers create slightly more induction of ambient air in comparison to the conventional diffuser.

  9. Experimental study on terahertz radiation

    Institute of Scientific and Technical Information of China (English)

    Liying Lang(郎利影); Qirong Xing(邢岐荣); Shuxin Li(李术新); Fanglin Mao(毛方林); Lu Chai(柴路); Qingyue Wang(王清月)

    2004-01-01

    In this letter, we describe a coherent subpicosecond terahertz (THz) spectroscopy system based on nonresonant optical rectification for the generation of THz radiation. We studied the two-photon absorption (TPA) of ZnTe induced by femtosecond laser pulses via THz generation, and its influence on the generation of THz radiation. Experimental results demonstrated that the intensity of pump beam against TPA must be traded off to get an optimum generation of THz radiation. As an example, we measured absorption spectrum of water vapor by time-domain spectroscopy (TDS) in the frequency range from 0.5 to 2.5 THzwith a high overall accuracy.

  10. Numerical and Experimental Study on the Development of Electric Sensor as for Measurement of Red Blood Cell Deformability in Microchannels

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Nakabe

    2012-08-01

    Full Text Available A microsensor that can continuously measure the deformability of a single red blood cell (RBC in its microchannels using microelectrodes is described in this paper. The time series of the electric resistance is measured using an AC current vs. voltage method as the RBC passes between counter-electrode-type micro-membrane sensors attached to the bottom wall of the microchannel. The RBC is deformed by the shear flow created in the microchannel; the degree of deformation depends on the elastic modulus of the RBC. The resistance distribution, which is unique to the shape of the RBC, is analyzed to obtain the deformability of each cell. First, a numerical simulation of the electric field around the electrodes and RBC is carried out to evaluate the influences of the RBC height position, channel height, distance between the electrodes, electrode width, and RBC shape on the sensor sensitivity. Then, a microsensor was designed and fabricated on the basis of the numerical results. Resistance measurement was carried out using samples of normal RBCs and rigidified (Ca2+-A23186 treated RBCs. Visualization measurement of the cells’ behavior was carried out using a high-speed camera, and the results were compared with those obtained above to evaluate the performance of the sensor.

  11. Experimental study of the factors governing the Staebler-Wronski photodegradation effect in a-Si:H solar cells. Final technical report, July 7, 1994--January 15, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Han, D [Univ. of North Carolina, Chapel Hill, NC (United States)

    1998-05-01

    This report describes continuing studies on electroluminescence (EL), field profile, and hydrogen microstructure by the University of North Carolina, Chapel Hill, during the third year and the extension period. Based on systematic studies of the EL, the authors developed a complete model to explain the unique features of the EL as dispersive-transport-controlled, non-geminate recombinant processes. This model can explain the main features of the EL, not only in hydrogenated amorphous silicon (a-Si:H), but also in other types of trap-rich materials. By employing the forward current and EL temperature-dependence studies, information of both the localized tail states and the deep defect states in real solar-cell structures were obtained concomitantly, which is crucial for the device performance. The authors measured the internal electric field profile in p-i-n and n-i-p cells by a null-current method; they studied the structure of the hydrogen clusters in hot-wire a-Si:H films, both theoretically and experimentally, and show a clear evidence of improved structural order in hot-wire a-Si:H, which is an important factor leading to more stable materials. To link the film microstructure to the metastability, the authors also started the film stress measurements.

  12. The Russian drug glyciphon, a representative of organophosphorus epoxides, for the treatment of basal cell carcinoma – clinical and experimental studies

    Directory of Open Access Journals (Sweden)

    L. N. Zalyalyutdinova

    2015-01-01

    Full Text Available The review deals with the results of clinical and experimental studies of the original Russian drug glyciphon used to treat basal cell carcinoma (BCC. Glyciphon is diglycidyl ether of methylphosphonic acid, which has been synthesized at the A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center, Russian Academy of Sciences, belongs to a class of organophosphors epoxides. The drug has been experimentally tested by Kazan scientists who revealed the selectivity of its antiblastoma activity, relatively low toxicity, and high safety when it was used long. The antiproliferatve activity of glyciphon in inhibiting DNA synthesis, retarding all mitotic phases, and blocking the entry of cells into S and M phases plays an important role in its mechanism of antiblastoma action. Glyciphon ointment 30 % is effective in the treatment of primary BCC (solitary tumors and polyneoplasms and its recurrences after radiation and surgery in the absence of a side skin resorption effect. It may be successfully used to treat BCC that are refractory to radiotherapy and surgical dissection and to detect latent foci of multiple BCC. The ointment is registered as an agent for the treatment of Stage I squamous cell carcinoma, as well as basaliomas (including recurrences after surgery and radiotherapy, Bowen,s disease, senile keratosis. Glyciphon is manufactured by OAO “Tatchempharmpreparaty” (Kazan (as 30 % ointment from the substance made by the affiliate of the A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center, Russian Academy of Sciences.

  13. Further Studies on Antioxidant Potential and Protection of Pancreatic β-Cells by Embelia ribes in Experimental Diabetes

    OpenAIRE

    Uma Bhandari; Neeti Jain; Pillai, K. K.

    2007-01-01

    This study was designed to examine the antioxidant defense by ethanolic extract of Embelia ribes on streptozotocin-(40 mg/kg, intravenously, single-injection) induced diabetes in Wistar rats. Forty days of oral feeding the extract (100 mg/kg and 200 mg/kg) to diabetic rats resulted in significant (P < .01) decrease in blood glucose, blood glycosylated haemoglobin, serum lactate dehydrogenase, creatine kinase, and increase in blood glutathione levels as compared to pathogenic diabetic rats. Fu...

  14. Numerical and experimental studies of mechanisms underlying the effect of pulsed broadband terahertz radiation on nerve cells

    Energy Technology Data Exchange (ETDEWEB)

    Duka, M V; Dvoretskaya, L N; Babelkin, N S; Khodzitskii, M K; Chivilikhin, S A; Smolyanskaya, O A [St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg (Russian Federation)

    2014-08-31

    We have studied the mechanisms underlying the effect of pulsed broadband terahertz radiation on the growth of neurites of sensory ganglia using a comparative analysis of measured reflection spectra of ganglion neurites (in the frequency range 0.1 – 2.0 THz) and spectra obtained by numerical simulation with CST Microwave Studio. The observed changes are shown to be mainly due to pulse energy absorption in the ganglion neurites. Of particular interest are the observed single resonance frequencies related to resonance size effects, which can be used to irradiate ganglia in order to activate their growth. (laser biophotonics)

  15. Differentiation of human umbilical cord Wharton’s jelly derived mesenchymal stem cells into sweat gland-like cells under special microenvironment:an experimental study

    Directory of Open Access Journals (Sweden)

    Yong-an XU

    2011-03-01

    Full Text Available Objective To identify the potentiality of human umbilical cord Wharton’s jelly derived mesenchymal stem cells(hUCWJ-MSCs differentiated into sweat gland-like cells under the cultivation of sweat gland-induction medium.Methods Sweat gland cells were harvested from normal skin by digesting with collagenase typeⅡ,heat-shocked and then the supernatants of medium were collected.The sweat gland-induction medium was prepared at 10% volume fraction.hUCWJ-MSCs were harvested by enzyme digestion,and the cell phenotypes were analyzed by flow cytometry(FCM.Alkaline phosphatase(ALP and Oil red-O staining were then performed after culturing in osteogenic and adipogenic induction medium for 2-3 weeks respectively.The hUCWJ-MSCs were cultured in sweat gland-induction medium for 3 weeks,the changes of cell morphology were observed with inverted microscope;the cells cultured for 1,2 and 3 weeks were harvested,and the expression of sweat gland markers(CEA,CK14 and CK19 were determined by immunohistochemistry and FCM,the expression of sweat gland development gene(EDA was determined by RT-PCR.Results The normal sweat gland cells exhibited clonal growth with a flagstone appearance,while the hUCWJ-MSCs showed spindle and myofibroblast-like phenotype,and the positive rate of CD44,CD105,CD34 and CEA detected by FCM was 97.37%,96.26%,0.56% and 0.52%,respectively.After cultured in osteogenic and adipogenic induction medium for 2-3 weeks,the hUCWJ-MSCs were induced into adipocytes of Oil red-O positive staining and osteocytes of ALP positive staining,respectively.After cultured in sweat gland-induction medium for 3 weeks,sweat gland-like structures were found,and sweat gland markers CEA,CK14 and CK19 were positive in differentiated hUCWJ-MSCs when detected by immunohistochemistry,the positive rate detected by FCM was 54.37%,60.25% and 62.13%,respectively.RT-PCR analysis revealed a high level expression of gene EDA in differentiated hUCWJ-MSCs.Conclusion The h

  16. Experimental depletion of different renal interstitial cell populations

    International Nuclear Information System (INIS)

    To define different populations of renal interstitial cells and investigate some aspects of their function, we studied the kidneys of normal rats and rats with hereditary diabetes insipidus (DI, Brattleboro) after experimental manipulations expected to alter the number of interstitial cells. DI rats showed an almost complete loss of interstitial cells in their renal papillae after treatment with a high dose of vasopressin. In spite of the lack of interstitial cells, the animals concentrated their urine to the same extent as vasopressin-treated normal rats, indicating that the renomedullary interstitial cells do not have an important function in concentrating the urine. The interstitial cells returned nearly to normal within 1 week off vasopressin treatment, suggesting a rapid turnover rate of these cells. To further distinguish different populations of interstitial cells, we studied the distribution of class II MHC antigen expression in the kidneys of normal and bone-marrow depleted Wistar rats. Normal rats had abundant class II antigen-positive interstitial cells in the renal cortex and outer medulla, but not in the inner medulla (papilla). Six days after 1000 rad whole body irradiation, the stainable cells were almost completely lost, but electron microscopic morphometry showed a virtually unchanged volume density of interstitial cells in the cortex and outer medulla, as well as the inner medulla. Thus, irradiation abolished the expression of the class II antigen but caused no significant depletion of interstitial cells

  17. Influence of the Charge State on the Structures and Interactions of Vancomycin Antibiotics with Cell-Wall Analogue Peptides: Experimental and Theoretical Studies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhibo; Vorpagel, Erich R.; Laskin, Julia

    2009-02-16

    In this study we examined the effect of the charge state on the energetics and dynamics of dissociation of the non-covalent complex between the vancomycin and the cell wall peptide analogue Nα,Nε-diacetyl-L-Lys-D-Ala-D-Ala (V-Ac2KDADA). The binding energies between the vancomycin and the peptide were obtained from the RRKM modeling of the time- and energy resolved surface-induced dissociation (SID) experiments. Our results demonstrate that the stability of the complex toward fragmentation increases in the order: [V+Ac2KDADA+H]+2 < [V+Ac2KDADA+H]+ < [V+Ac2KDADA-H]-. Dissociation of the singly protonated and singly deprotonated complex is characterized by very large entropy effects indicating substantial increase in the conformational flexibility of the resulting products. The experimental threshold energies of 1.75 eV and 1.34 eV obtained for the [V+Ac2KDADA-H]- and [V+Ac2KDADA+H]+ , respectively, are in excellent agreement with the results of density functional theory (DFT) calculations. The increased stability of the deprotonated complex observed experimentally is attributed to the presence of three charged sites in the deprotonated complex as compared to only one charged site in the singly protonated complex. The low binding energy of 0.93 eV obtained for the doubly protonated complex suggests that this ion is destabilized by Coulomb repulsion between the singly protonated vancomycin and the singly protonated peptide comprising the complex.

  18. Experimental study of oxidative DNA damage

    DEFF Research Database (Denmark)

    Loft, S; Deng, Xiaohong; Tuo, J;

    1998-01-01

    of dative DNA damage and tumour formation. In principle the level of oxidative DNA damage in an organ or cell may be studied by measurement of modified bases in extracted DNA by immunohistochemical visualisation, and from assays of strand breakage before and after treatment with repair enzymes. However......Animal experiments allow the study of oxidative DNA damage in target organs and the elucidation of dose-response relationships of carcinogenic and other harmful chemicals and conditions as well as the study of interactions of several factors. So far the effects of more than 50 different chemical...... to induce oxidative DNA damage in experimental animals. The hepatocarcinogen 2-nitropropane induces up to 10-fold increases in 8-oxodG levels in rat liver DNA. The level of 8-oxodG is also increased in kidneys and bone marrow but not in the testis. By means of 2-nitropropane we have shown correspondence...

  19. Effect of sesamin against cytokine production from influenza type A H1N1-induced peripheral blood mononuclear cells: computational and experimental studies.

    Science.gov (United States)

    Fanhchaksai, Kanda; Kodchakorn, Kanchanok; Pothacharoen, Peraphan; Kongtawelert, Prachya

    2016-01-01

    In 2009, swine flu (H1N1) had spread significantly to levels that threatened pandemic influenza. There have been many treatments that have arisen for patients since the WHO first reported the disease. Although some progress in controlling influenza has taken place during the last few years, the disease is not yet under control. The development of new and less expensive anti-influenza drugs is still needed. Here, we show that sesamin from the seeds of the Thai medicinal plant Sesamum indicum has anti-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs) induced by 2009 influenza virus type A H1N1. In this study, the combinatorial screening method combined with the computational approach was applied to investigate the new molecular binding structures of sesamin against the 2009 influenza virus type A H1N1 (p09N1) crystallized structure. Experimental methods were applied to propose the mechanisms of sesamin against cytokine production from H1N1-induced human PBMC model. The molecular dynamics simulation of sesamin binding with the p09N1 crystallized structure showed new molecular binding structures at ARG118, ILE222, ARG224, and TYR406, and it has been proposed that sesamin could potentially be used to produce anti-H1N1 compounds. Furthermore, the mechanisms of sesamin against cytokine production from influenza type A H1N1-induced PBMCs by ELISA and signaling transduction showed that sesamin exhibits the ability to inhibit proinflammatory cytokines, IL-1β and TNF-α, and to enhance the activity of the immune cell cytokine IL-2 via downregulating the phosphorylated JNK, p38, and ERK1/2 MAPK signaling pathways. This information might very well be useful in the prevention and treatment of immune-induced inflammatory disorders. PMID:26424131

  20. Effect of sesamin against cytokine production from influenza type A H1N1-induced peripheral blood mononuclear cells: computational and experimental studies.

    Science.gov (United States)

    Fanhchaksai, Kanda; Kodchakorn, Kanchanok; Pothacharoen, Peraphan; Kongtawelert, Prachya

    2016-01-01

    In 2009, swine flu (H1N1) had spread significantly to levels that threatened pandemic influenza. There have been many treatments that have arisen for patients since the WHO first reported the disease. Although some progress in controlling influenza has taken place during the last few years, the disease is not yet under control. The development of new and less expensive anti-influenza drugs is still needed. Here, we show that sesamin from the seeds of the Thai medicinal plant Sesamum indicum has anti-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs) induced by 2009 influenza virus type A H1N1. In this study, the combinatorial screening method combined with the computational approach was applied to investigate the new molecular binding structures of sesamin against the 2009 influenza virus type A H1N1 (p09N1) crystallized structure. Experimental methods were applied to propose the mechanisms of sesamin against cytokine production from H1N1-induced human PBMC model. The molecular dynamics simulation of sesamin binding with the p09N1 crystallized structure showed new molecular binding structures at ARG118, ILE222, ARG224, and TYR406, and it has been proposed that sesamin could potentially be used to produce anti-H1N1 compounds. Furthermore, the mechanisms of sesamin against cytokine production from influenza type A H1N1-induced PBMCs by ELISA and signaling transduction showed that sesamin exhibits the ability to inhibit proinflammatory cytokines, IL-1β and TNF-α, and to enhance the activity of the immune cell cytokine IL-2 via downregulating the phosphorylated JNK, p38, and ERK1/2 MAPK signaling pathways. This information might very well be useful in the prevention and treatment of immune-induced inflammatory disorders.

  1. Photovoltaic plants: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Fato, I.; Lazzarin, R.

    A photovoltaic unit, designed at the University of Bari and already in operation, is described as well as the methodology followed to measure the main characteristic parameters of its operation. The experimental results, compared with those obtained by applying semi-empirical calculations, suggest that load intermittence should be taken into account by introducing a parameter (N) into the calculation, and that intervention of the solar section control device should be considered.

  2. Experimental models to study cholangiocyte biology

    Institute of Scientific and Technical Information of China (English)

    Pamela S. Tietz; Xian-Ming Chen; Ai-Yu Gong; Robert C. Huebert; Anatoliy Masyuk; Tatyana Masyuk; Patrick L. Splinter; Nicholas F. LaRusso

    2002-01-01

    Cholangiocytes-the epithelial cells which line the bileducts-are increasingly recognized as importanttransporting epithelia actively involved in the absorptionand secretion of water, ions, and solutes. Thisrecognition is due in part to the recent development ofnew experimental models. New biologic concepts haveemerged including the identification and topography ofreceptors and flux proteins on the apical and/orbasolateral membrane which are involved in the molecularmechanisms of ductal bile secretion. Individually isolatedand/or perfused bile duct units from livers of rats andmice serve as new, physiologically relevant in vitromodels to study cholangiocyte transport. Biliary treedimensions and novel insights into anatomic remodeling ofproliferating bile ducts have emerged from three-dimensional reconstruction using CT scanning andsophisticated software. Moreover, new pathologicconcepts have arisen regarding the interaction ofcholangiocytes with pathogens such as Cryptosporidiumparvum. These concepts and associated methodologiesmay provide the framework to develop new therapies for the cholangiopathies, a group of important hepatobiliarydiseases in which cholangiocytes are the target cell.Tietz PS, Chen XM, Gong AY, Huebert RC, Masyuk A, MasyukT, Splinter PL, LaRusso NF. Experimental models to studycoholangiocyte biology.

  3. Estudio experimental sobre la utilización de células madre humanas en la terapia de los defectos periodontales: resultados preliminares Experimental study on the use of human stem cell therapy in periodontal defects: Preliminary results

    Directory of Open Access Journals (Sweden)

    F. Carini

    2011-08-01

    ón, con el fin de recrear la correcta anatomía estructural del periodonto perdido. Después de una fase de expansión celular, estas células se introducen en una estructura biomimética (andamios en colágeno, y se inducen a la diferenciación en sentido osteogénico. El producto final que consta de andamios y células mesenquimales diferenciadas en sentido osteoblástico, se instala por último en el defecto alveolar periodontal. La experimentación se basa en la posibilidad de utilizar células madre mesenquimales autólogas a partir de la médula ósea humana. La finalidad es la de estimular la regeneración de PDL cerca de la pared radicular y la formación de hueso nuevo sobre el PDL, beneficiándose de las técnicas de regeneración-reconstrucción ósea, de manera que se recree la correcta anatomía periodontal. Los resultados presentados en este trabajo conciernen el primer paciente tratado con esta metodología y afectarán los estudios siguientes para la prueba con una cobertura más amplia.Destruction of periodontal ligament and alveolar ridge rerorption caused by periodontal disease is the leading cause of tooth loss in adults. Therapy of advanced periodontal disease leads for a total recovery of the structure lost by the inability to regenerate the pristine correct anatomy system. The aim of this study is to assess the potential use of mesenchymal stem cells (MSCs in the regeneration of original periodontal structure. This study is an experimental phase 1 approved by the Italian Institute of Health on a limited number of patients; main objective will be to assess the biocompatibility and toxicity in vivo of differentiated mesenchymal stem cells into osteoblast sense, supported by biomimetic collagen scaffolds in patients with severe periodontal disease. The protocol describes transplantation of mesenchymal stem cells derived from samples of percutaneous bone marrow aspirate. The bone marrow cells are manipulated ex vivo to isolate mesenchymal stem cell

  4. Experimental study of MWEDM technology

    Institute of Scientific and Technical Information of China (English)

    DI Shi-chun; HUANG Rui-ning; CHI Guan-xin; ZHAO Wan-sheng

    2005-01-01

    This work deals with an experimental investigation of the machining characteristics of Micro Wire Electrical Discharge Machining (MWEDM). The MWEDM process consists of only one cutting operation varying with machining conditions. Experimental results show that the peak current and pulse duration have an obvious influence on surface roughness and machining time, and they also have an optimum value for the highest cutting speed. The servo reference voltage influences the surface roughness and machining time as well. In particular,the surface characteristics of work-pieces and a micro wire electrode were analyzed in detail too. Utilizing a micro wire electrode with diameter 30μm, MWEDM can machine a micro slot 38μm wide, which proves that the discharge gap can be controlled not more than 4μm. It can also machine micro gears respectively with a module 40μm, thickness 1mm, and a module 100μm, thickness 3.5mm. All kinds of micro shaped holes and complex micro parts can be easily machined as well.

  5. Evaluation of early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffold. An experimental study in Wistar rats.

    LENUS (Irish Health Repository)

    Alhag, Mohamed

    2011-03-01

    Tissue engineering using cell-seeded biodegradable scaffolds offers a new bone regenerative approach that might circumvent many of the limitations of current therapeutic modalities. The aim of this experiment was to study the early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds.

  6. T cells in multiple sclerosis and experimental autoimmune encephalomyelitis.

    LENUS (Irish Health Repository)

    Fletcher, J M

    2012-02-01

    Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS), which involves autoimmune responses to myelin antigens. Studies in experimental autoimmune encephalomyelitis (EAE), an animal model for MS, have provided convincing evidence that T cells specific for self-antigens mediate pathology in these diseases. Until recently, T helper type 1 (Th1) cells were thought to be the main effector T cells responsible for the autoimmune inflammation. However more recent studies have highlighted an important pathogenic role for CD4(+) T cells that secrete interleukin (IL)-17, termed Th17, but also IL-17-secreting gammadelta T cells in EAE as well as other autoimmune and chronic inflammatory conditions. This has prompted intensive study of the induction, function and regulation of IL-17-producing T cells in MS and EAE. In this paper, we review the contribution of Th1, Th17, gammadelta, CD8(+) and regulatory T cells as well as the possible development of new therapeutic approaches for MS based on manipulating these T cell subtypes.

  7. CREATIVE DISCLOSURE: AN EXPERIMENTAL STUDY

    OpenAIRE

    Cuzdriorean Dan Dacian; Vladu Alina Beattrice

    2012-01-01

    This empirical study extends the study conducted by Vladu, Grosanu and Cuzdriorean (2012) and reached similar conclusions. This particular research was conducted with the scope of assessing the impact of: positive bias, persuasive language, creative visual manipulation and performance comparisons over the unsophisticated users of accounting opinion. We have chosen this particular category since retail investors have been identified as relying on the information provided in corporate annual re...

  8. Comparison of Numerical and Experimental Studies for Flow-Field Optimization Based on Under-Rib Convection in Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Nguyen Duy Vinh

    2016-10-01

    Full Text Available The flow-field design based on under-rib convection plays an important role in enhancing the performance of polymer electrolyte membrane fuel cells (PEMFCs because it ensures the uniform distribution of the reacting gas and the facilitation of water. This research focused on developing suitable configurations of the anode and cathode bipolar plates to enhance the fuel cell performance based on under-rib convection. The work here evaluated the effects of flow-field designs, including a serpentine flow field with sub channel and by pass and a conventional serpentine flow-field on single-cell performance. Both the experiment and computer simulation indicated that the serpentine flow field with sub channel and by pass (SFFSB configuration enables more effective utilization of the electrocatalysts since it improves reactant transformation rate from the channel to the catalyst layer, thereby dramatically improving the fuel cell performance. The simulation and experimental results indicated that the power densities are increased by up to 16.74% and 18.21%, respectively, when applying suitable flow-field configurations to the anode and cathode bipolar plates. The findings in this are the foundation for enhancing efficient PEMFCs based on flow field design.

  9. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  10. CREATIVE DISCLOSURE: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Cuzdriorean Dan Dacian

    2012-07-01

    Full Text Available This empirical study extends the study conducted by Vladu, Grosanu and Cuzdriorean (2012 and reached similar conclusions. This particular research was conducted with the scope of assessing the impact of: positive bias, persuasive language, creative visual manipulation and performance comparisons over the unsophisticated users of accounting opinion. We have chosen this particular category since retail investors have been identified as relying on the information provided in corporate annual reports for decision making (Wills, 2008. Based on their relative inexperience and limited knowledge of these investors it is plausible that they can be mislead easily comparing to more sophisticated users of accounting information, as financial analysts. The main argument for conducting such a research is the fact that little research was conducted so far and the effects of creative disclosure on investment decision cannot be assessed so far. Based on this, we conducted a laboratory experiment where participants where provided with an informational set of financial data and required to make an investment decision. Our results document that the users perceptions is strongly affected by creative disclosure, contradictory with previous results documented in the literature, that their opinion cannot be influenced since they relay mostly on numerical information and less on the narrative segments of the financial statements. Even if our sample compressed few participants, we consider the results conclusive. A further research can extend the sample and test if our research hypothesis can be validated. Another possible spring of research can deal with the assessing of the opinion of the users of accounting information that are not considered unsophisticated, as financial analysts.

  11. Experimental study of ozone synthesis

    International Nuclear Information System (INIS)

    A silent discharge ozonizer has been constructed with a design that enables the study of ozone concentration behaviour as a function of different parameters when oxygen used as a working gas. The behaviour of ozone concentration as a function of discharge current density has four characteristic regions. The concentration is enhanced by more than threefold whenever gas pressure is reduced by a factor of two. The flow rate of the working gas is a more effective parameter on ozone concentration than the gas pressure. When the flow rate is kept constant, and the pressure is decreased by 100%, the ozone concentration increases by only 10%. On the other hand, when the flow rate is decreased by 13%, the ozone concentration increases by 200%, whenever the gas pressure is kept constant. The concentration is nearly doubled when the gap space is increased by four times under the same conditions. The length of the discharge region, the thickness and the dielectric constant of the insulating materials are found to have a considerable effect on the generated ozone concentration. Also, the ozone concentration is ten times less when air is used instead of oxygen as a working gas. A maximum efficiency of 185 g/kWh, is obtained for the present system

  12. Computational Fluid Dynamics and Experimental Study of Lock-in Phenomenon in Vortex-Induced Motions of a Cell-Truss Spar

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; YANG Jian-min; L(U) Hai-ning

    2009-01-01

    Spar platforms could be subject to vortex-induced-motions (VIM) in certain current conditions. Lock-in is a phenomenon which occurs in a range of reduced velocities in VIM. In this paper, a new concept of spar platform called cell-truss spar is studied using both computational fluid dynamics (CFD) and model test to investigate the VIM of the spar under different reduced velocities. The unique configuration of the cell-truss spar is carefully considered, and the unsteady flow around the spar is calculated and visualized in CFD simulations. A physical model with a scale ratio of 1:100 of the cell-truss spar is fabricated, and model tests are carried out in the current-generating ocean engineering basin. Many important parameters in VIM of the cell-truss spar are obtained, the occurrence of lock-in phenomenon is successfully simulated, and the mechanism and rules of lock-in are analyzed.

  13. Biomechanics of epithelial cell islands analyzed by modeling and experimentation

    CERN Document Server

    Coburn, Luke; Noppe, Adrian; Caldwell, Benjamin J; Moussa, Elliott; Yap, Chloe; Priya, Rashmi; Lobaskin, Vladimir; Roberts, Anthony P; Yap, Alpha S; Neufeld, Zoltan; Gomez, Guillermo A

    2016-01-01

    We generated a new computational approach to analyze the biomechanics of epithelial cell islands that combines both vertex and contact-inhibition-of-locomotion models to include both cell-cell and cell-substrate adhesion. Examination of the distribution of cell protrusions (adhesion to the substrate) in the model predicted high order profiles of cell organization that agree with those previously seen experimentally. Cells acquired an asymmetric distribution of protrusions (and traction forces) that decreased when moving from the edge to the island center. Our in silico analysis also showed that tension on cell-cell junctions (and monolayer stress) is not homogeneous across the island. Instead it is higher at the island center and scales up with island size, which we confirmed experimentally using laser ablation assays and immunofluorescence. Moreover, our approach has the minimal elements necessary to reproduce mechanical crosstalk between both cell-cell and cell substrate adhesion systems. We found that an i...

  14. Dye- and quantum dot-sensitized solar cells based on nanostructured wide-bandgap semiconductors via an integrated experimental and modeling study

    Science.gov (United States)

    Xin, Xukai

    Dye-sensitized solar cells (DSSCs) and quantum dot-sensitized solar cells (QDSSCs) are two promising alternative, cost-effective concepts for solar-to-electric energy conversion that have been offered to challenge conventional Si solar cells over the past decade. The configuration of a DSSC or a QDSSC consists of sintered TiO2 nanoparticle films, ruthenium-based dyes or quantum dots (QDs) (i.e., sensitizers), and electrolytes. Upon the absorption of photons, the dyes or QDs generate excitons (i.e., electron-hole pairs). Subsequently, the electrons inject into the TiO2 photoanode to generate photocurrent; scavenged by a redox couple, holes transport to the cathode. The overall power conversion efficiency (PCE) of a DSSC or QDSSC is dictated by the light harvest efficiency, quantum yield for charge injection, and charge collection efficiency at the electrodes. The goal of our research is to understand the fundamental physics and performance of DSSCs and QDSSCs with improved PCE at the low cost based on rational engineering of TiO2 nanostructures, sensitizers, and electrodes through an integrated experimental and modeling study. In this presentation, I will discuss three aspects that I have accomplished over the last several years. (1) Effects of surface treatment and structural modification of photoanode on the performance of DSSCs. First, our research indicates that the surface treatment with both TiCl4 and oxygen plasma yields the most efficient dye-sensitized TiO2-nanoparticle solar cells. A maximum PCE is achieved with a 21 microm thick TiO2 film; the PCE further increases to 8.35% after TiCl4 and O 2 plasma treatments, compared to the untreated TiO2 ( PCE = 3.86%). Second, we used a layer of TiO2 nanoparticle film coated on the FTO glass, and a bilayer of TiO2nanoparticle/freestanding TiO2 nanotube film deposited on the FTO glass as photoanodes. The J˜V parameter analysis acquired by equivalent circuit model simulation reveals that nanotubular structures are

  15. Experimental Studies of Selected Aqueous Electrochemical Systems Relevant for Materials Processing in the Fabrications of Microelectronic Components and Direct Alcohol Fuel Cells

    Science.gov (United States)

    Shi, Xingzhao

    A broad range of electrochemical techniques are employed in this dissertation to investigate a selected set of aqueous electrochemical systems that are relevant for materials processing in the fabrication of microelectronic devices and direct alcohol fuel cells. In terms of technical applications, this work covers three main experimental systems: (i) chemical mechanical planarization (CMP), (ii) electro-less nickel deposition, and (iii) direct alkaline glycerol fuel cells. The first two areas are related to electronic device fabrications and the third topic is related to cost-effective energy conversion. The common electrochemical aspect of these different systems is that, in all these cases the active material characteristics are governed by complex (often multi-step) reactions occurring at metal-liquid (aqueous) interfaces. Electro-analytical techniques are ideally suited for studying the detailed mechanisms of such reactions, and the present investigation is largely focused on developing adequate analytical strategies for probing these reaction mechanisms. In the fabrication of integrated circuits, certain steps of materials processing involve CMP of Al deposited on thin layers of diffusion barrier materials like Ta/TaN, Co, or Ti/TiN. A specific example of this situation is found in the processing of replacement metal gates used for high-k/metal-gate transistors. Since the commonly used barrier materials are nobler than Al, the Al interface in contact with the barrier can become prone to galvanic corrosion in the wet CMP environment. Using model systems of coupon electrodes and two specific barrier metals, Ta and Co, the electrochemical factors responsible for these corrosion effects are investigated here in a moderately acidic (pH = 4.0) abrasive-free solution. The techniques of cyclic voltammetry and impedance spectroscopy are combined with strategic measurements of galvanic currents and open circuit potentials (OCPs). L-ascorbic acid (AA) is employed as a

  16. Valproic acid, an inhibitor of class I histone deacetylases, reverses acquired Erlotinib-resistance of lung adenocarcinoma cells: a Connectivity Mapping analysis and an experimental study.

    Science.gov (United States)

    Zhuo, Wenlei; Zhang, Liang; Zhu, Yi; Xie, Qichao; Zhu, Bo; Chen, Zhengtang

    2015-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) have been used as a powerful targeting therapeutic agent for treatment of lung adenocarcinoma for years. Nevertheless, the efficacy of TKI was hampered by the appearance of acquired TKI-resistance. In the present study, we aimed to search, predict, and screen the agents that can overcome the acquired TKI-resistance of lung adenocarcinoma by using the expression profiles of differentially expressed genes (DEGs) and Connectivity map (CMAP). The profiles of DEGs were obtained by searching GEO microarray database, and then, they were submitted to CMAP for analysis in order to predict and screen the agent that might reverse the TKI-resistance of lung cancer cells. Next, the effects of the selected agent on TKI-resistant cancer cells were tested and the possible signaling pathways were also evaluated. As a result, valproic acid (VPA) was selected. Then, we used a low-concentration of VPA that has little effect on the cell growth for analysis. Interestingly, the results showed that treatment with a combination of VPA and Erlotinib significantly led to a decrease in cell viability and an increase in cell apoptosis for TKI-resistant HCC827-ER cells, relative to those treated with VPA or Erlotinib alone. Further experiments confirmed that inhibition of MAPK and AKT might be involved in this process. Analyzing the DEGs through the CMAP is a good strategy for exploitation of anti-tumor agents. VPA might markedly increase the sensitivity of TKI-resistant lung adenocarcinoma cells to Erlotinib, thus reversing the acquired TKI-resistance of cancer cells and raising VPA as a potential agent for TKI-resistant lung cancer therapy. PMID:26328250

  17. Photosensitization of experimental hepatocellular carcinoma with protoporphyrin synthesized from administered δaminolevulinic acid. Studies with cultured cells and implanted tumors

    International Nuclear Information System (INIS)

    Background/Aims: Photodynamic therapy using porphyrins or related compounds and laser light is an investigational treatment for neoplasms. The aim of this study was to establish whether this might be applicable for hepatocellular carcinoma using protoporphyrin synthesized in the tissue from administered δ-aminolevulinic acid. Methods: We measured porphyrin accumulation in normal rat hepatocytes and Morris hepatoma cells in culture, and in subcutaneously implanted hepatomas and other tissues of the rat after administration of δ-aminolevulinic acid, and assessed cell and tissue damage after application of laser light. Results: Porphyrin accumulation after δ-aminolevulinic acid was added to the medium was greater and continued to increase for a longer period of time in hepatoma cells than in hepatocytes (1337±42 vs 513±31 fluorescence units/cell at 8 h, means±SE, p<0.001). After intraperitoneal injection of δaminolevulinic acid to rats with subcutaneously growing hepatomas, porphyrin content in tumor and liver was similar at 4 h but was higher in tumor at 6 h. Laser light caused necrosis of normal and malignant liver cells in culture and subcutaneous hepatomas in vivo. Conclusions: We conclude from these in vitro and in vivo studies that porphyrin accumulation after administration of δaminolevulinic acid in this hepatoma is substantial and time dependent, and delivery of laser light locally can cause tumor photosensitization and necrosis. (au) 41 refs

  18. Protein kinase D regulates cell death pathways in experimental pancreatitis

    Directory of Open Access Journals (Sweden)

    Jingzhen eYuan

    2012-03-01

    Full Text Available Inflammation and acinar cell necrosis are two major pathological responses of acute pancreatitis, a serious disorder with no current therapies directed to its molecular pathogenesis. Serine/threonine protein kinase D family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple physiological and pathophysiological effects. We recently reported that PKD/PKD1, the predominant PKD isoform expressed in rat pancreatic acinar cells, mediates early events of pancreatitis including NF-kappaB activation and inappropriate intracellular digestive enzyme activation. In current studies, we investigated the role and mechanisms of PKD/PKD1 in the regulation of necrosis in pancreatic acinar cells by using two novel small molecule PKD inhibitors CID755673 and CRT0066101 and molecular approaches in in vitro and in vivo experimental models of acute pancreatitis. Our results demonstrated that both CID755673 and CRT0066101 are PKD-specific inhibitors and that PKD/PKD1 inhibition by either the chemical inhibitors or specific PKD/PKD1 siRNAs attenuated necrosis while promoting apoptosis induced by pathological doses of cholecystokinin-octapeptide (CCK in pancreatic acinar cells. Conversely, upregulation of PKD expression in pancreatic acinar cells increased necrosis and decreased apoptosis. We further showed that PKD/PKD1 regulated several key cell death signals including inhibitors of apoptotic proteins (IAPs, caspases, receptor-interacting protein kinase 1 (RIP1 to promote necrosis. PKD/PKD1 inhibition by CID755673 significantly ameliorated necrosis and severity of pancreatitis in an in vivo experimental model of acute pancreatitis. Thus, our studies indicate that PKD/PKD1 is a key mediator of necrosis in acute pancreatitis and that PKD/PKD1 may represent a potential therapeutic target in acute pancreatitis.

  19. 人胃癌原代细胞的甲硫氨酸依赖性研究%Experimental studies on methionine dependence of human primary gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    曹伟新; 欧敬民; 尹浩然; 朱正纲; 燕敏

    2001-01-01

    目的:探索人胃癌和胃粘膜上皮原代细胞在体外不含甲硫氨酸(Met)而含同型半胱氨酸(Hcy)培养基(Met-Hcy+)中能否正常生长及是否存在Met依赖性。 方法: 将新鲜人胃癌及胃粘膜组织制成单细胞悬液,分别置于Met-Hcy+和Met+Hcy-培养基中培养,利用细胞计数和流式细胞分选仪检测各组细胞增殖状态。 结果:人胃癌原代细胞在Met-Hcy+培养基中生长受抑,表现为细胞总数减少,G0、G1期细胞比例下降,S期细胞比例升高。胃粘膜细胞在Met-Hcy+培养基中生长正常,细胞总数及细胞周期比例未受影响。 结论:人胃癌原代细胞在体外培养中表现出Met依赖性,而胃粘膜细胞则未见类似现象。%Objectives:To study the methionine dependence (Met-dependence) ofhuman primary gastric cancer cells in vitro when Met in the culture medicine was replaced by its precussor homocysteine(Hcy). Methods:Fresh and sterile gaotric cancer samples and normal gastric mucosa were managed into single-cell suspension and were cultured in the Met-Hcy+ and Met+ Hcy- medium separately.proliferation of these cells in the two different culture media was examined by cell counter and flow cytometry (FCM). Results:In the Met+Hcy- medium,the growth of primary gastric cancer cells was inhibited,manifesting that the percentage of G0G1 tumor cells decreased and that of the S phase increased signiflcantly.However,normal gastric mucosal cells grew well and their cell cycles had no change. Conclusions:Human primary gastric cancer cells are Met-dependent in vitro whereas normal gastric mucosal cells have no similar results.

  20. Experimental study and mechanism analysis on bioeffects by nanosecond electromagnetic pulses

    Institute of Scientific and Technical Information of China (English)

    王保义; 杨杰斌; 郭庆功; 徐润民; 刘长军; 张弘; 邹方东; 王子淑

    1997-01-01

    The athermal bioeffects caused by nanosecond electromagnetic pulses with body cells was studied by using a broad band transverse EM-wave cell (BTEM CELL). The experimental system and preliminary mechanism analysis were presented.

  1. Experimental study of the nucleon spin structure

    International Nuclear Information System (INIS)

    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.)

  2. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.

    1996-05-07

    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.).

  3. Experimental investigation of fuel cell dynamic response and control

    Science.gov (United States)

    Williams, Keith A.; Keith, Warren T.; Marcel, Michael J.; Haskew, Timothy A.; Shepard, W. Steve; Todd, Beth A.

    An experimental study of the dynamic response of a commercial fuel cell system is presented in this work. The primary goal of the research is an examination of the feasibility for using fuel cells in a load-following mode for vehicular applications, where load-following implies that the fuel cell system provides the power necessary for transient responses without the use of additional energy storage elements, such as batteries or super-capacitors. The dynamic response of fuel cell systems used in the load-following mode may have implications for safe and efficient operation of vehicles. To that end, a DC-DC converter was used to port the power output of the fuel cell to a resistive load using a pulse-width-modulating circuit. Frequency responses of the system were evaluated at a variety of DC offsets and AC amplitudes of the PWM duty cycle from 1 out to 400 Hz. Open-loop transient responses are then evaluated using transitions from 10% to 90% duty cycle levels, followed by dwells at the 90% level and then transitions back to the 10% level. A classical proportional-integral controller was then developed and used to close the loop around the system, with the result that the fuel cell system was driven to track the same transient. The controller was then used to drive the fuel cell system according to a reference power signal, which was a scaled-down copy of the simulated power output from an internal combustion engine powering a conventional automobile through the Federal Urban Driving Schedule (FUDS). The results showed that the fuel cell system is capable of tracking transient signals with sufficient fidelity such that it should be applicable for use in a load-following mode for vehicular applications. The results also highlight important issues that must be addressed in considering vehicular applications of fuel cells, such as the power conditioning circuit efficiency and the effect of stack heating on the system response.

  4. Experimental Study of Mouse Cytomegalovirus Infected Mice

    Institute of Scientific and Technical Information of China (English)

    崔雯; 董永绥; 方峰

    2002-01-01

    Summary: In order to investigate the human cytomegalovirus (HCMV) infection, the mouse cytomegalovirus (MCMV) infected mice were experimentally studied. 6 to 8 week old female BALB/C mice with immunosuppression were selected to undergo the MCMV inoculations: intracranial inoculation and peritoneal inoculation. MCMV of the infected mice in various organs and tissues were detected by using β-gal staining and in situ nucleic acid hybridization assay. The pathological changes were observed in HE staining paraffin-embedded sections. It was found that all the MCMV infected mice showed the retardation of growth and development, and feather looseness. Both intracranial inoculation of 104 PFU viruses or peritoneal inoculation of 106 PFU viruses resulted in the pathological changes, to some extent, of various organs and tissues in the mice. The pathological changes in liver were consistent with the amount of β-gal staining positive cells, indicating the liver lesions were mainly caused by viral proliferation. It was also found that the viruses in the immunosuppressed mice subjected to intracranial inoculation could spread to whole body organs, while the viruses in the immunosuppressed mice subjected to intrapeitoneal inoculation couldn't spread to the brain, suggesting blood-brain barrier could prevent the virus from spreading to the brain.

  5. EXPERIMENTAL STUDY ON VISCOELASTIC PROPERTIES OF HEPATOCELLULAR CARCINOMA CELLS%肝癌细胞粘弹性的实验研究

    Institute of Scientific and Technical Information of China (English)

    张钢; 龙勉; 吴泽志

    2001-01-01

    作者用微管吸吮技术测定了肝癌细胞的粘弹性, 并进一步研究了秋水仙素和细胞松驰素D对其影响。结果表明,肝癌细胞弹性系数较肝细胞高,秋水仙素作用后使肝癌细胞与肝细胞的粘弹性以不同的效应方式和强度发生变化,细胞松驰素D则使两种细胞粘弹性均呈现相似的下降趋势。上述结果反映了癌细胞在骨架结构和机能上的变化,这种变化可能对癌细胞浸润和转移有影响。%The viscoelastic properties of hepatocellular carcinoma (HCC) cells were measured by means of micropipette aspiration technique. Further,the authors studied the changes in viscoelastic coefficients by treating with colchicine and cytochalasin D. The results showed that the elastic coefficients of HCC cells were obviously higher than the corresponding value of hepatocytes. By treating with colchicine, the effects on viscoelastic properties of HCC cells were obviously different in ways and extents from those on viscoelastic properties of hepatocytes.,but the viscoelastic properties of hepatocytes by treated with cytochalasin D had the same trend of decreasing as those of HCC cells. These results represent the change in cytoskeleton structure and function among hepatocytes and HCC cells, this change might affect tumor cells invasion and metastasis.

  6. Experimental and theoretical study of possible correlation between the electrochemistry of canthin-6-one and the anti-proliferative activity against human cancer stem cells

    Science.gov (United States)

    Cebrián-Torrejón, G.; Doménech-Carbó, A.; Scotti, M. T.; Fournet, A.; Figadère, B.; Poupon, E.

    2015-12-01

    This work presents an approach to study the performance of novel targets able to overcome cancer stem cell chemoresistance, based on the voltammetric data for microparticulate films of natural or synthetic alkaloids from the canthin-6-one series. A comparison of this voltammetric technique with conventional solution phase electrochemistry suggests the differences in the anti-proliferative activity of canthin-6-ones could be tentatively correlated to their different capacity to generate semiquinone radical anions. These data also match theoretical calculations.

  7. Experimental study on cultivation and purification of bone marrow-derived mesenchymal stem cells and its co-culture with chitosan porous scaffolds in vitro

    Directory of Open Access Journals (Sweden)

    Feng YAN

    2014-12-01

    Full Text Available Background As commonly used scaffold material in tissue engineering, chitosan has many advantages, such as strong biodegradability, low antigenicity, good biocompatibility and no pyrogen reaction. This study aims to isolate, cultivate and purify Sprague-Dawley (SD rat bone marrow-derived mesenchymal stem cells (BMSCs, and to observe the growth of BMSCs when co-cultured with self-made chitosan porous scaffold in vitro and to test the biocompatibility of this tissue engineering scaffold, so as to lay the foundation for promoting nerve regeneration of transplant treatment.  Methods Three-week-old healthy male SD rats were used in this study, and BMSCs were isolated and purified through bone marrow adherent culture method. The surface markers of BMSCs at Passage 3 were detected and identified by flow cytometry (FCM and the BMSCs were three?dimensionally cultured in vitro on chitosan porous scaffolds produced by freeze-drying method. Ethanol alternative method was used to detect the chitosan scaffold porosity. Scanning electron microscope was used to explore the internal structure of the scaffold, measure the size of its aperture, and observe the morphology and development of the cells within the scaffold. Methyl thiazolyl tetrazolium (MTT method was used to determine the cells' proliferation.  Results The cultured BMSCs were uniform and similiar to fibrous arrangement, and mixed cells reduced obviously. The identification result of FCM showed the CD29 positive rate was 98.49% and CD45RA positive rate was only 0.85%. The chitosan scaffold had an interlinked, uniform similar three-dimensional porous structure and its aperture porosity was 90%. Some cells stretched out pseudopod and infiltrated into the porous structure of scaffold, even fusing with them. The BMSCs were seeded in the scaffold successfully. The chitosan scaffold had no obvious effect on BMSCs' proliferation. Conclusions Chitosan porous scaffolds have good structural character and

  8. Experimental hepatology applied to stem cells.

    Science.gov (United States)

    Burra, P; Tomat, S; Villa, E; Gasbarrini, A; Costa, A N; Conconi, M T; Forbes, S J; Farinati, F; Cozzi, E; Alison, M R; Russo, F P

    2008-01-01

    Transplantation is an accepted treatment today for many people suffering from organ failure. More and more patients are referred for transplant surgery, and the waiting lists are growing longer because not enough organs and tissues are donated for transplantation. This has led to several potentially viable alternatives being considered, including bio-artificial support devices, the transplantation of mature cells or stem/progenitor cells and the potential transplantation of xenogenic organs and cells [Burra P, Samuel D, Wendon J, Pietrangelo A, Gupta S. Strategies for liver support: from stem cells to xenotransplantation. J Hepatol 2004;41:1050-9]. Numerous investigators around the world are engaged in these investigations and the pace of discovery has begun to accelerate in recent years. To take stock of the achievements of recent years, the AISF sponsored a Single-Topic Conference, held in Padua on 26-27 May, 2006, with the participation of many leading investigators from various parts of Italy and Europe. This present paper summarizes the content of the Conference. Different issues were analysed, from the biology of stem cells to the possible use of gene therapy. The speakers were clinicians and scientists interested in diseases not only of the liver but also of other organs such as the kidney or heart. The fact that numerous specialties were represented helped the audience to understand the stem cell research area from different standpoints, and what research has achieved so far.

  9. Roscovitine suppresses CD4+ T cells and T cell-mediated experimental uveitis.

    Directory of Open Access Journals (Sweden)

    Zili Zhang

    Full Text Available BACKGROUND: T cells are essential for the development of uveitis and other autoimmune diseases. After initial activation, CD4+ lymphocytes express the co-stimulatory molecule OX40 that plays an important role in T cell proliferation. Cyclin dependent kinase 2 (CdK2 plays a pivotal role in the cell cycle transition from G1 to S phase. In addition, recent research has implicated CdK2 in T cell activation. Thus, we sought to test the immunosuppressive effect of roscovitine, a potent CdK2 inhibitor, on CD4+ T cell activation, proliferation, and function. DESIGN AND METHODS: Mouse CD4+ T cells were activated by anti-CD3 and anti-CD28 antibodies. The expression of OX40, CD44, and CdK2 were analyzed by flow cytometry. In addition, cell cycle progression and apoptosis of control and roscovitine-treated T lymphocytes were measured by BrdU incorporation and annexin V assay, respectively. Furthermore, the immunoregulatory effect of roscovitine was evaluated in both ovalbumin-induced uveitis and experimental autoimmune uveitis (EAU models. RESULTS: In this study, we found that T cell activation induced OX40 expression. Cell cycle analysis showed that more CD4+OX40+ cells entered S phase than OX40- T cells. Concurrently, CD4+OX40+ cells had a higher level of CdK2 expression. Roscovitine treatment blocked activated CD4+ cells from entering S phase. In addition, roscovitine not only reduced the viability of CD4+ lymphocytes but also suppressed T cell activation and cytokine production. Finally, roscovitine significantly attenuated the severity of T cell-dependent, OX40-enhanced uveitis. CONCLUSION: These results implicate CdK2 in OX40-augmented T cell response and expansion. Furthermore, this study suggests that roscovitine is a novel, promising, therapeutic agent for treating T cell-mediated diseases such as uveitis.

  10. Experimental radiation carcinogenesis is studies at NIRS

    International Nuclear Information System (INIS)

    Experimental radiation carcinogenesis studies conducted during the past decade at NIRS are briefly reviewed. They include the following: 1) Age dependency of susceptibility to radiation carcinogenesis. 2) Radiation-induced myeloid leukemia. 3) Mechanism of fractionated X-irradiation (FX) induced thymic lymphomas. 4) Significance of radiation-induced immunosuppression in radiation carcinogenesis in vivo. 5) Other ongoing studies. (author)

  11. Experimental study of tile grout material behavior

    OpenAIRE

    Kumpová, I. (Ivana); Kloiber, M. (Michal); Ševčík, R. (Radek); Kytýř, D. (Daniel)

    2014-01-01

    Study provides preliminary results of experimental study of tile grout material behavior. Experiments were performed with the use of microCT, three point bending test and methods for chemical analysis. It was proven that material behave very elastic and the suitability of the combination of used methods.

  12. An experimental study of the dynamic behavior of a 2 kW proton exchange membrane fuel cell stack under various loading conditions

    International Nuclear Information System (INIS)

    The dynamic behavior of the PEM (proton exchange membrane) fuel cell stack has great effect on the safety and effective operation of its applications. In this paper, a self-designed bulb-array is used to simulate the various loading conditions and study the dynamic behavior of a 2 kW PEM fuel cell stack. An evaluation index, including oscillation rate, pressure variation and dynamic resistance factor, is used to analyze the transient response of the PEM fuel cell stack. It is observed that the stack current increases about 8.6%, and the Oscillation rate decreases more rapidly after activation. In the step-up load stage, the oscillation rate and the dynamic resistance decrease more rapidly as the external load increases. Due to the periodic anodic purge process, a periodic voltage fluctuation can be seen. In addition, when the stack works in the open-loop state (working without the external load), the transient response of the stack current is significantly affected by the hydrogen humidity and the charge double-layer. - Highlights: • The working time of open-loop state significantly affects the transient response. • Oscillation rate decreases faster as the external load increases. • Dynamic resistance factor decreases as the external load increases. • The periodic anodic purge process leads to a slight periodic oscillation of voltage

  13. EXPERIMENTAL STUDY ON THE CORNEAL ENDOTHELIUM OF TRAUMATIC CATARACT

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    The cell morphology of corneal endothelium in 84 mice with experimental traumatic cataract was investigated with stained corneal buttons. In the experimental group, the boundaries between adjacent corneal endothelial cells were significantly distorted, some cell boundaries manifested degenerative changes that led to coalescence of the cells. The mean density and mean area of endothelial cells of the controls showed significant difference from those of the experimental group during the 12 weeks of observ...

  14. Experimental Study on Allograft of Rabbit Adipose-derived Stem Cells Transplantation%兔异体脂肪干细胞移植的实验研究

    Institute of Scientific and Technical Information of China (English)

    杨涛; 杨勇; 刘斌; 李龙; 令狐大科; 刘彦普

    2013-01-01

    Objective: To establish an animal model for the injectable allo-transplantation fat tissue transplantation and to investigate the morphological and immunologic changes of rejection after ear allo-transplantation in rabbit. Methods: 30 healthy New Zealand white rabbits were divided into three groups randomly. The autologous adipose granule (AG) were implanted in the ears of the rabbits as the experiment group A(N=6). The autologous adipose granule (AG) combined with platelet-rich fibrin(PRF) were implanted in ears as the experiment group B(N=6). The autologous adipose granule(AG) combined with autologous adipose-derived stem cells(ADSCs)were implanted in ears as the experiment group C(N=6). The autologous adipose granule(AG) combined with platelet-rich fibrin(PRF) and autologous adipose-derived stem cells(ADSCs) were implanted in the ears were the control group D(N=6). The autologous adipose granule (AG) combined with platelet-rich fibrin (PRF) and allo-transplantation adipose-derived stem cells (ADSCs) were implanted in the ears were the control group E(N=6).At month 1,3 and 6 after transplantation, the level of CD4/CD8 in lymph cells and IL-2, IL-4 in plasma of the rabbits were examined. Results: At 1,3and 6 months after surgery, the differences of the two groups D, E and group A, B, C were statistical significant (P 0.05). Conclusion: The autologous adipose granule (AG) combined with platelet-rich fibrin (PRF) and autologous adipose-derived stem cells (ADSCs) can improve the survival rate of transplanted fat tissue and provide experimental basis for clinical fat allo-transplantation.%目的:建立一种可注射异体脂肪移植模型,观察兔异体脂肪干细胞(adipose-derived stem cells,ADSCs)复合自体脂肪颗粒(adipose granule,AG)和富血小板纤维蛋白(platelet-rich fibrin,PRF)移植后的形态学和免疫学的变化,为临床异体脂肪干细胞移植提供一种实验依据.方法:取30只健康新西兰家兔,随机分成5组:A组,(N=6),

  15. Sudden Termination Auctions—An Experimental Study

    NARCIS (Netherlands)

    Füllbrunn, S.C.; Sadrieh, A.

    2012-01-01

    The design of online markets has become a major issue due to the capability of operators to implement almost any set of market rules overnight. With this study we contribute to the literature of auction market design by presenting a theoretical and experimental analysis of sudden termination auction

  16. EBTS:DESIGN AND EXPERIMENTAL STUDY.

    Energy Technology Data Exchange (ETDEWEB)

    PIKIN,A.; ALESSI,J.; BEEBE,E.; KPONOU,A.; PRELEC,K.; KUZNETSOV,G.; TIUNOV,M.

    2000-11-06

    Experimental study of the BNL Electron Beam Test Stand (EBTS), which is a prototype of the Relativistic Heavy Ion Collider (RHIC) Electron Beam Ion Source (EBIS), is currently underway. The basic physics and engineering aspects of a high current EBIS implemented in EBTS are outlined and construction of its main systems is presented. Efficient transmission of a 10 A electron beam through the ion trap has been achieved. Experimental results on generation of multiply charged ions with both continuous gas and external ion injection confirm stable operation of the ion trap.

  17. Experimental study of negative capacitance in LEDs

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-feng; WANG Jun; ZHU Chuan-yun; CONG Hong-xia; CHEN Yong; WANG Cun-da

    2005-01-01

    The experimental study on negative capacitance(NC) of various light-emitting diodes(LEDs) is presented.Experimental result shows that all LEDs display the NC phenomenon.The voltage modulated electroluminescence(VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence.The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar: NC phenomenon is more obvious with higher voltage or lower frequency.

  18. Characterization of normal and cancer stem cells: One experimental paradigm for two kinds of stem cells

    OpenAIRE

    Mayol, Jean-François; Loeuillet, Corinne; Hérodin, Francis; Wion, Didier

    2009-01-01

    The characterization of normal stem cells and cancer stem cells uses the same paradigm. These cells are isolated by a Fluorescent-Activated Cell Sorting step and their stemness is assayed following implantation into animals. However, differences exist between these two kinds of stem cells. Therefore, the translation of the experimental procedures used for normal stem cell isolation into the cancer stem cell research field is a potential source of artefacts. In addition, normal stem cell thera...

  19. Experimental and Modelling Studies of Biomass Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Ka Leung Lam; Adetoyese Olajire Oyedu~; Chi Wai Hui

    2012-01-01

    The analysis on the feedstock pyrolysis characteristic and the impacts of process parameters on pyrolysis outcomes can assist in the designing, operating and optimizing pyrolysis processes. This work aims to utilize both experimental and modelling approaches to perform the analysis on three biomass feedstocks--wood sawdust, bamboo shred and Jatropha Curcas seed cake residue, and to provide insights for the design_and operation of pyro-lysis processes. For the experimental part, the study investigated the effect of heating rate, final pyrolysis tempera- ture and sample size on pyrolysis using common thermal analysis techniques. For the modelling part, a transient mathematical model that integrates the feedstock characteristic from the experimental study was used to simulate the pyrolysis progress of selected biomass feedstock particles for reactor scenarios. The model composes of several sub-models that describe pyrolysis kinetic and heat flow, particle heat transfer, particle shrinking and reactor opera-tion. With better understanding of the effects of process conditions and feedstock characteristics on pyrolysis through both experimental and modelling studies, this work discusses on the considerations of and interrelation between feedstock size, pyrolysis energy usage, processing time and product quality for the design and operation of pyrolysis processes.

  20. Money, Happiness, and Aspirations: An Experimental Study

    OpenAIRE

    Michael McBride

    2007-01-01

    The past decade has witnessed an explosion of interest in the scientific study of happiness. Economists, in particular, find that happiness increases in income but decreases in income aspirations, and this work prompts examination of how aspirations form and adapt over time. This paper presents results from the first experimental study of how multiple factors -- past payments, social comparisons, and expectations -- influence aspiration formation and reported satisfaction. I find that expecta...

  1. Experimental Characterization and Modeling of PEM Fuel Cells

    DEFF Research Database (Denmark)

    Jespersen, Jesper Lebæk

    Fuel cells are strong candidates to become the power sources of the 21th century. Despite, being close to mass market entry for several years, fuel cells still are still only found in prototypes and very few commercial products. The reason for this is that fuel cells currently suffer from too high...... production prices and too short life times, in relation to market requirements. The focus of this thesis has been to develop experimental techniques, that can aid in the development of making fuel cells cheaper and more durable. The overall purpose of the experiments conducted in this project, is to provide...... fundamental knowledge of the transport and electrochemical processes of PEM fuel cells and to provide methods for obtaining high quality data for PEM fuel cell simulation model validation. In this thesis three different areas of experimental characterization techniques was investigated, they include: Stack...

  2. Vaccination against Experimental Allergic Encephalomyelitis with T Cell Receptor Peptides

    Science.gov (United States)

    Howell, Mark D.; Winters, Steven T.; Olee, Tsaiwei; Powell, Henry C.; Carlo, Dennis J.; Brostoff, Steven W.

    1989-11-01

    Experimental allergic encephalomyelitis (EAE) is an autoimmune disease of the central nervous system mediated by CD4+ T cells reactive with myelin basic protein (MBP). Rats were rendered resistant to the induction of EAE by vaccination with synthetic peptides corresponding to idiotypic determinants of the β chain VDJ region and Jα regions of the T cell receptor (TCR) that are conserved among encephalitogenic T cells. These findings demonstrate the utility of TCR peptide vaccination for modulating the activity of autoreactive T cells and represent a general therapeutic approach for T cell--mediated pathogenesis.

  3. Design study of blanket structure for tokamak experimental fusion reactor

    International Nuclear Information System (INIS)

    Design study of the blanket structure for JAERI Experimental Fusion Reactor (JXFR) has been carried out. Studied here were fabrication and testing of the blanket structure (blanket cells, blanket rings, piping and blanket modules), assembly and disassembly of the blanket module, and monitering and testing technique. Problems in design and fabrication of the blanket structure could be revealed. Research and development problems for the future were also disclosed. (author)

  4. What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

    KAUST Repository

    Brett, Daniel J. L.

    2010-08-20

    Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an \\'experimental functional map\\' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models. © 2010 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim.

  5. Mesenchymal stem cells differentially modulate effector CD8+ T cell subsets and exacerbate experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Glenn, Justin D; Smith, Matthew D; Calabresi, Peter A; Whartenby, Katharine A

    2014-10-01

    Mesenchymal stem cells (MSC) have emerged as a promising candidate for inflammatory suppression and disease amelioration, especially of neuro-inflammatory diseases such as multiple sclerosis (MS). Auto-reactive CD4+ and CD8+ T cells acquire pathogenic IFNγ-producing- (Type I) and IL-17A-producing- (Type 17) effector phenotypes in MS and its animal model experimental autoimmune encephalomyelitis (EAE). Although MSC have been extensively demonstrated to suppress pathogenic effector CD4+ T cells and CD4+ T cell-mediated EAE, surprisingly few studies have addressed their modulation of effector CD8+ T cells represented in MS or their impact on CD8+ T cell-mediated EAE. We find that MSC differentially modulate CD8+ T cell development depending on effector T cell subtype. MSC drive activated low-IFNγ producers toward an enhanced high-IFNγ Tc1-like phenotype but strongly inhibit the production of IL-17A and Tc17 polarization in vitro. These observations are underscored by differential MSC modulation of T cell activation, proliferation, and signature transcription factor up-regulation. In addition, effector CD8+ T cells co-cultured with MSC exhibited increased production of IL-2, a molecule known to enhance IFNγ, yet suppress IL-17A, production. Based on these in vitro effects on CD8+ T cells, we next evaluated their impact on the severity of EAE. To better evaluate CD8+ T cells, we immunized mice with MOG37-50 , which is a CD8-targeted epitope. Our results revealed a worsening of disease, consistent with their in vitro stimulation of Tc1 cells. These findings highlight the emerging duality of MSC in immune modulation and provide implications for their future use in immune-related diseases. PMID:24911892

  6. Pulsed total dose damage effect experimental study on EPROM

    International Nuclear Information System (INIS)

    Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

  7. Oxidovanadium(IV/V) complexes as new redox mediators in dye-sensitized solar cells: a combined experimental and theoretical study.

    Science.gov (United States)

    Apostolopoulou, Andigoni; Vlasiou, Manolis; Tziouris, Petros A; Tsiafoulis, Constantinos; Tsipis, Athanassios C; Rehder, Dieter; Kabanos, Themistoklis A; Keramidas, Anastasios D; Stathatos, Elias

    2015-04-20

    Corrosiveness is one of the main drawbacks of using the iodide/triiodide redox couple in dye-sensitized solar cells (DSSCs). Alternative redox couples including transition metal complexes have been investigated where surprisingly high efficiencies for the conversion of solar to electrical energy have been achieved. In this paper, we examined the development of a DSSC using an electrolyte based on square pyramidal oxidovanadium(IV/V) complexes. The oxidovanadium(IV) complex (Ph4P)2[V(IV)O(hybeb)] was combined with its oxidized analogue (Ph4P)[V(V)O(hybeb)] {where hybeb(4-) is the tetradentate diamidodiphenolate ligand [1-(2-hydroxybenzamido)-2-(2-pyridinecarboxamido)benzenato}and applied as a redox couple in the electrolyte of DSSCs. The complexes exhibit large electron exchange and transfer rates, which are evident from electron paramagnetic resonance spectroscopy and electrochemistry, rendering the oxidovanadium(IV/V) compounds suitable for redox mediators in DSSCs. The very large self-exchange rate constant offered an insight into the mechanism of the exchange reaction most likely mediated through an outer-sphere exchange mechanism. The [V(IV)O(hybeb)](2-)/[V(V)O(hybeb)](-) redox potential and the energy of highest occupied molecular orbital (HOMO) of the sensitizing dye N719 and the HOMO of [V(IV)O(hybeb)](2-) were calculated by means of density functional theory electronic structure calculation methods. The complexes were applied as a new redox mediator in DSSCs, while the cell performance was studied in terms of the concentration of the reduced and oxidized form of the complexes. These studies were performed with the commercial Ru-based sensitizer N719 absorbed on a TiO2 semiconducting film in the DSSC. Maximum energy conversion efficiencies of 2% at simulated solar light (AM 1.5; 1000 W m(-2)) with an open circuit voltage of 660 mV, a short-circuit current of 5.2 mA cm(-2), and a fill factor of 0.58 were recorded without the presence of any additives in the

  8. Experimental Studies of Artificial Conscious Systems

    Institute of Scientific and Technical Information of China (English)

    蔡义发

    1995-01-01

    Human consciousness is the most interesting and mysterious phenomenon in the world.In this paper,the results of the computational study and simulation of the conscious behaviour,such as the learning of language and image patterns,traditional conditioning,association,imagination and dream,have been presented.Based on these results,an experimental conscious systekm-CONSCITRON,has been developed.Further discussion on development of artificial conscious systems is also provided.

  9. [Experimental study of pinostrobine oxime biotransformation].

    Science.gov (United States)

    Sariev, A K; Abaimov, D A; Tankevich, M V; Prokhorov, D I; Adekenov, S M; Arystan, L I; Seĭfulla, R D

    2014-01-01

    We have experimentally studied pathways of elimination of an oximized derivative of phytoflavonoid pinostrobine by HPLC/mass spectrometry. Four potential metabolites of pinostrobine oxime have been found and there was an attempt to determine their molecular structures on the basis of their fragmentation under positive electrospray ionization conditions. It is established that pinostrobine oxime is removed from the organism mainly unchanged and also in the form of glucuronated derivative. PMID:25335390

  10. Theoretical and experimental studies of elementary particles

    International Nuclear Information System (INIS)

    This report discusses: Fixed target experimentation at Fermilab; the D-zero collider experiment at Fermilab; deep inelastic lepton nucleon scattering; non-accelerator experiments and non-linear QED; the AMY experiment at TRISTAN and other activities at KEK; the collider detector at Fermilab; laser switched linac; preparations for experiments at the SSC; search for massive stable particles; and the Advanced Study Institute on techniques and concepts of high energy physics

  11. The ultrastructural changes in the liver cells induced by high doses of Benzodiazepine Tranquilizing drugs: An experimental transmission electron microscopic study on male guinea pigs

    International Nuclear Information System (INIS)

    Benzodiazepines are tranquilizing psychotropic drugs. Unfortunately, despite their therapeutic benefits, they are illegally consumed in high doses by some addicts to reach a sedative, exhilarative and euphoria state similar to that produced by narcotic substances. The present study, using transmission electron microscope on male guinea pigs, aims to investigate the potential ultrastructural changes in the liver cells induced by the high doses of Benzodiazepines. Animals in three treated groups administrated a daily combined dose consisted of (10mg Alprazolam with 10mg Diazepam/day/animal) for three different treatment periods: 7, 15, and 25 days. The ultrastructural examination of the hepatocytes of the animals treated for 15 days showed limited changes in the form of marginal heterochromatine accompanied with marginal nucleoli enlargement. On the other hand, severe ultrastructural damages are observed in the animals treated for 25 days, which appeared in the following various patterns: fatty degeneration of the hepatocytes as indicated by the accumulation of large number of lipid droplets in the cytoplasm, marked nuclear atrophy in some necrotic hepatocytes, massive nuclear degeneration in other hepatocytes, mitochondrial damages in the form of cristea destruction accompanied with abnormal oval shape, massive lysis of the cytoplasmic organelles with severe plasma membrane rupture. In conclusion, the observed ultrastructural damages in the present study may refer to the potential hepatotoxic effects of the high dose of Benzodiazepins. It is recommended that much more official restrictions should be applied on the pharmacies sector to prevent any illegal selling of these drugs in order to prevent abusers from obtaining them, as unfortunately in some developing countries the illegal selling of these drugs is known to occur due to the absence of official control. (author)

  12. Experimental model for collagen estimation in cell culture Modelo experimental para avaliação do colágeno em cultura de células

    OpenAIRE

    Sidney Mamoru Keira; Lydia Masako Ferreira; Alfredo Gragnani; Ivone da Silva Duarte; José Barbosa

    2004-01-01

    In the study of Plastic Surgery, cell culture may be used at experimental level in researches concerning biosynthesis functions of skin cells such as fibroblasts, keratinocytes, adipocytes, chondrocytes and osteocytes. The present study reports an experimental model for estimation of collagen in cell cultures using chromogenic precipitation reaction with an especific dye (Sirius Red).Dentro do estudo da Cirurgia Plástica, a cultura de células pode ser utilizada em experimentos relativos às fu...

  13. The Experimental and Clinical Study on the Effect of Curcumin on Cell Cycle Proteins and Regulating Proteins of Apoptosis in Acute Myelogenous Leukemia

    Institute of Scientific and Technical Information of China (English)

    陈燕; 吴裕丹; 何静; 陈文娟

    2002-01-01

    Summary: To investigate whether the Bcl-2 gene family is involved in modulating mechanism ofapoptosis and change of cell cycle protein induced by curcumin in acute myeloid leukemia HL-60cell line and primary acute myelogenous leukemic cells, the Bcl-2 family member Mcl-l, Bax andBak and cell cycle proteins including P27kipl, P21wafl, cyclin D3 and pRbp- were selected and their ex-pression detected by SABC immuno-histochemical stain method. The attitude of sub-G1 peak inDNA histogram was determined by FCM. The TUNEL positive cell percentage was identified byterminal deoxynucleotidyl transferase ( TdT )-mediated Biotin dUNP end labeling technique. Itwas found that when HL-60 cells were treated with 25 μmol/L curcumin for 24 h, the expressionlevel of Mcl-1 was down-regulated, but that of Bax and Bak up-regulated time-dependently. Therewas significant difference in the expression level of Mcl-1, Bax and Bak between the curcumin-treated groups and control group (P<0. 05-0. 01). At the same time, curcumin had no effect onprogress of cell cycle in primaty acute myelogenous leukemia at newly diagnosis, but could in-crease the peak of Sub-G1 (P<0. 05), and down-regulate the expression of Mcl-1 and up-regulatethe expression of Bax and Bak with the difference being statistically significant. The expression ofP27kipl, P21wafl and pRbp- were elevated and that of cyclin D3 decreased in the presence of curcumin.These findings suggested that the Bcl-2 gene family indeed participated in the regulatory process ofapoptosisinduced by curcumin in HL-60 cells and AML cells. Curcumin can induce apoptosis ofprimary acute myelogenous leukemic cells and disturb cell cycle progression of HL-60 cells. Themechanism appeared to be mediated by perturbing Go/G1 phases checkpoints which associated withup-regulation of P27kipl, P21wafl and pRbp- expression, and down-regulation of cyclin D3.

  14. Fully Bayesian Experimental Design for Pharmacokinetic Studies

    Directory of Open Access Journals (Sweden)

    Elizabeth G. Ryan

    2015-03-01

    Full Text Available Utility functions in Bayesian experimental design are usually based on the posterior distribution. When the posterior is found by simulation, it must be sampled from for each future dataset drawn from the prior predictive distribution. Many thousands of posterior distributions are often required. A popular technique in the Bayesian experimental design literature, which rapidly obtains samples from the posterior, is importance sampling, using the prior as the importance distribution. However, importance sampling from the prior will tend to break down if there is a reasonable number of experimental observations. In this paper, we explore the use of Laplace approximations in the design setting to overcome this drawback. Furthermore, we consider using the Laplace approximation to form the importance distribution to obtain a more efficient importance distribution than the prior. The methodology is motivated by a pharmacokinetic study, which investigates the effect of extracorporeal membrane oxygenation on the pharmacokinetics of antibiotics in sheep. The design problem is to find 10 near optimal plasma sampling times that produce precise estimates of pharmacokinetic model parameters/measures of interest. We consider several different utility functions of interest in these studies, which involve the posterior distribution of parameter functions.

  15. Experimental study on partial coherence source

    CERN Document Server

    Zhao Xue Qing; Yuan Xiao; LiuJingRu; Wang Long Hua; Tang Ying; Huang, Kerson

    2002-01-01

    Partial coherence source is a key part in the laser system using echelon-free introduced spatial incoherence beam smoothing technique. Different kinds of partial coherence sources have been studied experimentally for improving the uniformity of laser intensity distribution. It is found that the source produced by excimer laser scattering on the surface of a teflon plate is ideal. The properties of this kind of source are studied. As a result, the uniformity of source beam intensity distribution, the beam spatial coherence and energy transfer efficiency of the source are obtained

  16. Core seismic study on experimental VHTR

    International Nuclear Information System (INIS)

    The experimental Very High Temperature Reactor (VHTR) core consists of about 1700 blocks (fuel blocks, replaceable reflectors, permanent reflectors, and core support blocks) and other structures surrounding the blocks. A major research and development effort was initiated in 1975 to study the dynamic response of the experimental VHTR core arrangement to seismic excitation. First, a VHTR core seismic test program was prepared. Next, basic tests and analysis were carried out according to the program. Tests and apparatus and test results are described for one-column and one-region tests, vertical two-dimensional test, and horizontal two-dimensional test. Many data on the response characteristics of columns and the effect of the side support stiffness on the core vibration characteristics were derived from the basic tests

  17. Activation of Pancreatic Stellate Cells in Human and Experimental Pancreatic Fibrosis

    OpenAIRE

    Haber, Paul S; Keogh, Gregory W.; Apte, Minoti V.; Moran, Corey S.; Stewart, Nancy L.; Crawford, Darrell H.G.; Pirola, Romano C.; McCaughan, Geoffrey W.; Ramm, Grant A; Wilson, Jeremy S.

    1999-01-01

    The mechanisms of pancreatic fibrosis are poorly understood. In the liver, stellate cells play an important role in fibrogenesis. Similar cells have recently been isolated from the pancreas and are termed pancreatic stellate cells. The aim of this study was to determine whether pancreatic stellate cell activation occurs during experimental and human pancreatic fibrosis. Pancreatic fibrosis was induced in rats (n = 24) by infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duc...

  18. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2011-07-01

    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  19. Erythropoietin in Myocardial Infarction: Experimental Evidence and Clinical Studies

    OpenAIRE

    Andreas Stein; Ilka Ott

    2011-01-01

    Erythropoietin produced mainly in the kidney is the main regulator of erythropoiesis. Experimental studies identified additional, non-haematopoietic, protective effects during myocardial ischemia and reperfusion due to inhibition of apoptosis, stimulation of vasculogenesis and progenitor cell mobilisation. Based on these findings, five prospective, randomised, clinical trials have been performed. A short term regimen of erythropoietin was applied during PCI in patients with STEMI up to a cumu...

  20. Mesenchymal stem cells in the treatment of inflammatoryand autoimmune diseases in experimental animal models

    Institute of Scientific and Technical Information of China (English)

    Matthew W Klinker; Cheng-Hong Wei

    2015-01-01

    Multipotent mesenchymal stromal cells [also known asmesenchymal stem cells (MSCs)] are currently beingstudied as a cell-based treatment for inflammatorydisorders. Experimental animal models of humanimmune-mediated diseases have been instrumental inestablishing their immunosuppressive properties. Inthis review, we summarize recent studies examiningthe effectiveness of MSCs as immunotherapy in severalwidely-studied animal models, including type 1 diabetes,experimental autoimmune arthritis, experimentalautoimmune encephalomyelitis, inflammatory boweldisease, graft-vs -host disease, and systemic lupuserythematosus. In addition, we discuss mechanismsidentified by which MSCs mediate immune suppressionin specific disease models, and potential sources offunctional variability of MSCs between studies.

  1. The Cell Nucleus in Physiological and Experimentally Induced Hypometabolism

    Science.gov (United States)

    Malatesta, M.

    The main problem for manned space mission is, at present, represented by the mass penalty associated to the human presence. An efficient approach could be the induction of a hypometabolic stasis in the astronauts, thus drastically reducing the physical and psychological requirements of the crew. On the other hand, in the wild, a reduction in resource consumptions physiologi- cally occurs in certain animals which periodically enter hibernation, a hypometabolic state in which both the energy need and energy offer are kept at a minimum. During the last twelve years, we have been studying different tissues of hibernating dormice, with the aim of analyzing their features during the euthermia -hibernation-arousal cycle as well as getting insight into the mechanisms allowing adaptation to hypometabolism. We paid particular attention to the cell nucleus, as it is the site of chief metabolic functions, such as DNA replication and RNA transcription. Our observations revealed no significant modification in the basic features of cell nuclei during hibernation; however, the cell nuclei of hibernating dormice showed unusual nuclear bodies containing molecules involved in RNA pathways. Therefore, we supposed that they could represent storage/assembly sites of several factors for processing some RNA which could be slowly synthesised during hibernation and rapidly and abundantly released in early arousal in order to meet the increased metabolic needs of the cell. The nucleolus also underwent structural and molecular modifications during hibernation, maybe to continue important nucleolar functions, or, alternatively, permit a most efficient reactivation upon arousal. On the basis of the observations made in vivo , we recently tried to experimentally induce a reversible hypometabolic state in in vitro models, using cell lines derived from hibernating and non-hibernating species. By administering the synthetic opioid DADLE, we could significantly reduce both RNA transcrip- tion and

  2. Continuous game dynamics: an experimental study.

    Energy Technology Data Exchange (ETDEWEB)

    Patelli, P. (Palolo); Sato, Yuzuru

    2004-01-01

    In this paper we study an experiment with human agents strategically interacting in a game characterized by continuous time and continuous strategy space. The research is focused in studying the agents interaction dynamic under different experimental settings. The agents play a two person game that is an extension of the classic Cournot duopoly. Having agents making decision continuously allows us to track the temporal structure of strategy evolution very precisely. We can follow the agents continuous behavior evolution avoiding the data under-sampling. To our knowledge this is the first attempt to approach experimentally the continuous time decision making. We also emphasize that the focus of our work is not the Cournot model but rather the more general problem of studying the agents strategic interaction dynamic in continuous space time. Flaming the problem as the well studied Cournot Duopoly would be a good starting point. In economics dynamics studies the oligopoly model literature in both discrete and continuous time is one of the richest. There is also a vast literature in experimental economics about repeated games in general and more specifically in duopoly/oligopoly models. Cox and Walker studied whether subjects can learn to play the Cournot Duopoly strategies comparing the experimental results with the theoretical prediction of learning models. The Cox Walker experiment differs from our settings because it is in discrete time and is an evolutionary dynamics framework through a random matching mechanism of the experimental subjects. From the theoretical perspective many works have been focused in studying the Cournot model in a dynamical settings. Okuguchi and Szidarovsky formulated a continuous time version of the Cournot Oligopoly with multiproduct firms. They analyzed the stability of the equilibrium and proved that it is stable, under certain conditions, independently from the value of the adjustments. Chiarella and Khomin extended this analysis to

  3. Experimental and thermodynamic approach on proton exchange membrane fuel cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Miansari, Me. [Islamic Azad University Ghaemshahr, P.O. Box 163, Ghaemshahr (Iran); Sedighi, K.; Alizadeh, E.; Miansari, Mo. [Department of Mechanical Engineering, Noushirvani University of Technology, P.O. Box 484, Babol (Iran); Amidpour, M. [Department of Mechanical Engineering, K.N. Toosi University, Box 15875-4416, Tehran (Iran)

    2009-05-15

    The present work is employed in two sections. Firstly the effect of different parameters such as pressure, temperature and anode and cathode channel depth on the performance of the proton exchange membrane (PEM) fuel cell was experimentally studied. The experimental result shows a good accuracy compared to other works. Secondly a semi-empirical model of the PEM fuel cell has been developed. This model was used to study the effect of different operating conditions such as temperature, pressure and air stoichiometry on the exergy efficiencies and irreversibilities of the cell. The results show that the predicted polarization curves are in good agreement with the experimental data and a high performance was observed at the channel depth of 1.5 mm for the anode and 1 mm for the cathode. Furthermore the results show that increase in the operating temperature and pressure can enhance the cell performance, exergy efficiencies and reduce irreversibilities of the cell. (author)

  4. Experimental and thermodynamic approach on proton exchange membrane fuel cell performance

    Science.gov (United States)

    Miansari, Me.; Sedighi, K.; Amidpour, M.; Alizadeh, E.; Miansari, Mo.

    The present work is employed in two sections. Firstly the effect of different parameters such as pressure, temperature and anode and cathode channel depth on the performance of the proton exchange membrane (PEM) fuel cell was experimentally studied. The experimental result shows a good accuracy compared to other works. Secondly a semi-empirical model of the PEM fuel cell has been developed. This model was used to study the effect of different operating conditions such as temperature, pressure and air stoichiometry on the exergy efficiencies and irreversibilities of the cell. The results show that the predicted polarization curves are in good agreement with the experimental data and a high performance was observed at the channel depth of 1.5 mm for the anode and 1 mm for the cathode. Furthermore the results show that increase in the operating temperature and pressure can enhance the cell performance, exergy efficiencies and reduce irreversibilities of the cell.

  5. Leveraging the Experimental Method to Inform Solar Cell Design

    Science.gov (United States)

    Rose, Mary Annette; Ribblett, Jason W.; Hershberger, Heather Nicole

    2010-01-01

    In this article, the underlying logic of experimentation is exemplified within the context of a photoelectrical experiment for students taking a high school engineering, technology, or chemistry class. Students assume the role of photochemists as they plan, fabricate, and experiment with a solar cell made of copper and an aqueous solution of…

  6. Transfer of experimental allergic encephalomyelitis to bone marrow chimeras. Endothelial cells are not a restricting element

    International Nuclear Information System (INIS)

    The adoptive transfer of clinical and histopathologic signs of experimental allergic encephalomyelitis (EAE) requires MHC compatibility between cell donor and cell recipient. The results of adoptive transfer studies using F1 to parent bone marrow chimeras as recipients of parental-derived BP-sensitive spleen cells indicate that this restriction is not expressed at the level of the endothelial cell but is confined to the cells of bone marrow derivation. Furthermore, these results indicate that the development of EAE is not dependent on the activity of MHC-restricted cytotoxic cells

  7. 胶质瘤细胞系摄取BPA的实验研究%Experimental study on BPA uptake of glioma cell lines

    Institute of Scientific and Technical Information of China (English)

    杨磊; 赵葵; 王潇; 隋丽; 孔福全; 郝小娟; 郑洁莹; 马南茹; 崔素珍; 刘权卫

    2012-01-01

    Objective: to evaluate the incorporation of BPA by glioma cell lines, and to observe its relationship with the temperature and the concentration of BPA. Methods; C6, U251 and rat astrocyte cells were incubated in a culture medium, in which ' B concentration was 20, 40, 60, 80, 100 μg/mL for 24 h. Boron concentration in the cells was measured induced couple plasma-atomic emission spectroscopy (ICP-AES). C6 cells were pre-incu-bated for 24 h with different boron concentrations in growth medium. Then the mediums were changed to boron-free ones, and boron content was assessed after 1, 2, 3 h. Results; The content of the 10B in cells was increasing with the increasing concentration of BPA, and the boron concentration ratios of glioma cells to astrocyte are 2. 2. The BPA efflux is slower at the lower temperature. Conclusion; BPA has a selectivity for glioma cells, and the results of the efflux assay confirm the temperature dependence of the BPA transport out of the cells.%目的:探讨BPA(2,2-双(4-羟基苯基)丙烷,Bisphenol A)浓度和温度对胶质瘤细胞系摄取和析出10B的影响.方法:将C6和U251两种胶质瘤细胞系,及大鼠正常脑胶质细胞培养在含不同浓度BPA(10B浓度分别为20、40、60、80、100 μg/mL)的培养基中24h后,采用感应耦合等离子体原子发射光谱(ICP-AES)法测定细胞内硼的含量;将C6细胞培养在含不同浓度BPA的培养基中培养24h后,更换为不含10B培养基,在不同温度条件(4、25、37℃)下继续培养,并分别于换液后的1、2、3h,用ICP-AES方法检测细胞内的硼含量.结果:细胞内硼浓度随培养基中BPA浓度的增加而增高,胶质瘤细胞内10B浓度约为正常胶质细胞的2.2倍;温度越高,细胞内硼析出速度越快.结论:BPA对胶质瘤细胞系具有一定亲和力;细胞对10B的析出速率具有温度依赖性.

  8. Laparoscopic ureterocalicostomy in pigs - experimental study

    Directory of Open Access Journals (Sweden)

    Paulo Fernando de Oliveira Caldas

    2015-07-01

    Full Text Available This study aimed to evaluated laparoscopic ureterocalicostomy as treatment of experimental ureteropelvic junction (UPJ obstruction in pigs. Ten male Large White pigs weighting approximately 28.4 (±1.43 kg were used in the current study. The UPJ obstruction was created laparoscopically by double-clipping of the left ureter. After 14 days the animals underwent laparoscopic ureterocalicostomy f The animals were sacrificed for subsequent retrograde pyelography in order to assess the anastomotic patency on the 28th day. The laparoscopic procedure for experimental obstruction of UPJ was successfully performed in all animals, as well as the laparoscopic ureterocalicostomy. There was intestinal iatrogenic injury in one animal. Satisfactory UPJ patency was noted in 75% of the animals. There was no stenosis of the proximal anastomosis between the ureter and the lower pole of the kidney in 37.5%, mild stenosis in 37.5% and severe stenosis in 25% of the animals. The laparoscopic approach for reestablishment he urinary flow by ureterocalicostomy was feasible in the porcine model. The ascending pyelography revealed satisfactory results of the laparoscopic ureterocalicostomy

  9. An Experimental Study on Effects of Distilled White-ginseng Herbal Acupuncture on A549 human ephithelial lung cancer cell in vitro and implanted Sarcoma-180 in vivo

    OpenAIRE

    Jong-Seong We; Ki-Rok Kwon; Hee-Soo Park

    2004-01-01

    Objectives : In order to investigate effects and immune improvement of distilled white-ginseng herbal extract, expression of Cox-1, Cox-2, and mRNA of Bcl-2 and Bax were analyzed in A549 cell in vivo. Survival time and expression of cytokine mRNA were measured for the mice with Sarcoma-180 induced abdominal cancer. Methods : Balb/c mouse was treated with distilled white-ginseng Herbal Acupuncture at Wisu(BL21) and Chung-wan(CV12) to investigate anti-cancer effects and immune response. R...

  10. An Experimental Study on Effects of Distilled Red-ginseng Herbal Acupuncture on A549 human ephithelial lung cancer cell in vitro and implanted Sarcoma-180

    OpenAIRE

    Seung Hwan Won; Ki-Rok, Kwon; Sun-Gu, Lee

    2004-01-01

    Objectives : In order to investigate effects and immune improvement of distilled red-ginseng herbal Acupuncture, expression of Cox-1, Cox-2, and mRNA of Bcl-2 and Bax were analyzed in A549 cell in vivo. Survival time and expression of cytokine mRNA were measured for the mice with Sarcoma-180 induced abdominal cancer. Methods : Balb/c mouse was treated with distilled red-ginseng Herbal Acupuncture at Wisu(BL21) and Chung- wan(CV12) to investigate anti-cancer effects and immune response. ...

  11. Assessment of re-distribution and efficacy of stem cell transplantation in different heart status after acute myocardial infarction by MRI: an experimental study

    International Nuclear Information System (INIS)

    Objective: To evaluate the efficacy of MRI for assessment of re-distribution of bone marrow mesenchymal stem cells injected intramyocardially in main organs (heart, liver, spleen and kidney) under different heart status (beating or arresting) in a porcine model. Methods: Bone marrow-derived mesenchymal stem cells were obtained from the male swine and labeled with iron oxide during culture. Acute myocardial infarction was created in female swine, one week later, the survivors were randomly divided into 4 groups. Cardiopulmonary bypass was set up to arrest the heart, and then labeled cells (1 × 108) were intramyocardially injected into the border of the infracted myocardium in group 1 (n=6). The same volume of cells was grafted into the beating heart in group 2 (n=6). In group 3 and 4, saline was injected into either the arresting or beating myocardium. Three days later, re-distribution of stem cells and cardiac function were assessed by T2* WI and cine MRI, respectively. All animals were sacrificed for histology and real-time quantitative polymerase chain reaction (RT-PCR) of sex-determining region on Y-chromosome (SRY) investigation. The ANOVA and t test was used for statistics. Results: The left ventricular end- diastolic volume (LVEDV) before transplantation for group 1-4 were: (56.8±5.3), (54.8±6.8), (57.4±4.3) and (56.8±2.8) ml, and after transplantation for group 1-4 were: (65.2±5.2), (63.2± 3.7), (60.2±4.7) and (62.2±4.4) ml. The left ventricular end-systolic volume (LVESV) before transplantation for group 1-4 were : (33.5±7.6), (32.3±5.3), (33.5±3.6) and (32.7±4.6) ml, and after transplantation for group 1-4 were: (37.3±5.6), (36.3±6.9), (34.3±5.4) and (36.3± 8.1) ml. The left ventricular EF values (LVEF) before transplantation for group 1-4 were: (42.3± 7.2)%, (41.7±6.8)%, (41.8±8.6)% and (42.7±7.7)%, and after transplantation for group 1- 4 were: (44.5±8.7)%, (43.1±7.4)%, (42.8±5.6)% and (43.3±8.4)%. The myocardial infarction area

  12. Morfologia das células intersticiais de ovários policísticos de ratas: um estudo experimental Morphology of the interstitial cells of rat polycystic ovaries: an experimental study

    Directory of Open Access Journals (Sweden)

    Leonardo Augusto Lombardi

    2012-07-01

    Full Text Available OBJETIVOS: Avaliar a histomorfometria das células intersticiais dos ovários, bem como analisar a concentração sanguínea de esteroides sexuais de ratas portadoras de ovários policísticos induzidos pela luz contínua. MÉTODOS: Vinte ratas foram divididas em dois grupos: ratas na fase de estro (GCtrl e ratas portadoras de ovários policísticos induzidos pela iluminação contínua (GOP. Os animais do GCtrl permaneceram com período de luz das 7:00 s 19:00 horas, e os animais do GOP, com iluminação contínua (400 Lux, durante um período de 60 dias. Ao final desse período todos os animais foram anestesiados, foi coletado o sangue, para determinação dos níveis séricos de estradiol (E2, progesterona (P4 e testosterona (T, seguido da retirada dos ovários que foram fixados em formol a 10% e processados para inclusão em parafina. Cortes histológicos com 5 µm corados pela hematoxilina e eosina foram utilizados para análise histomorfométrica. As análises morfológicas, contagem de cistos, determinação da concentração e do volume nuclear das células intersticiais foram realizadas com o auxílio de microscópio de luz adaptado a uma câmera de alta resolução (AxioCam, cujas imagens foram transmitidas e analisadas em computador com software AxioVision Rel 4.8 (Carl Zeiss. Os dados obtidos foram submetidos ao teste t de Student (pGCtrl=73,2±6,5; pGCtrl=80,6±3,9; pGOP=4,2±1,5; pGCtrl=63,6±16,5; pGCtrl=6,9±3,2; pPURPOSES: To evaluate the histomorphometry of ovarian interstitial cells, as well as the blood sex steroid concentrations of female rats with polycystic ovaries induced by continuous light. METHODS: Twenty female rats were divided into two groups: Control Group - in the estrous phase (CtrlG, and a group of rats with polycystic ovaries induced by continuous illumination (POG. CtrlG animals were maintained on a light period from 07:00 a.m. to 07:00 p.m., and POG animals with continuous illumination (400 Lux for 60 days

  13. Experimental study on low pressure flow instability

    International Nuclear Information System (INIS)

    The experiment was performed on the test loop (HRTL-5), which simulates the geometry and system design of the 5 MW reactor. The flow behavior for a wide range of inlet subcooling, in which the flow undergoes from single phase to two phase, is described in a natural circulation system at low pressure (p = 0.1, 0.24 MPa). Several kinds of flow instability, e.g. subcooled boiling instability, subcooled boiling induced flashing instability, pure flashing instability as well as flashing coupled density wave instability and high frequency flow oscillation, are investigated. The mechanism of flashing and flashing concerned flow instability, which has never been studied well in this field, is especially interpreted. The experimental results show that, firstly, for a low pressure natural circulation system the two phase flow is unstable in most of inlet subcooling conditions, the two phase stable flow can only be reached at very low inlet subcooling; secondly, at high inlet subcooling the flow instability is dominated by subcooled boiling in the heated section, and at middle inlet subcooling is dominated by void flashing in the adiabatic long riser; thirdly, in two phase stable flow region the condition for boiling out of the core, namely, single phase flow in the heated section, two phase flow in the riser due to vapor flashing, can be realized. The experimental results are very important for the design and accident analysis of the vessel and swimming pool type natural circulation nuclear heating reactor. (7 refs., 10 figs., 1 tab.)

  14. Experimental Study on Unconfined Vapor Cloud Explosion

    Institute of Scientific and Technical Information of China (English)

    毕明树; ABULITI; Abudula

    2003-01-01

    An experimental system was setup to study the pressure field of unconfined vapor cloud explosions.The semi-spherical vapor clouds were formed by slotted 0.02mm polyethylene film.In the Center of the cloud was an ignition electrode that met ISO6164"Explosion protection System" and NFPA68 "Guide for Venting of Deflagrations". A data-acquisition system,with dymame responding time less than 0.001s with 0.5% accuracy,recorded the pressure-time diagram of acetylene-air mixture explosion with stoichiometrical ratio.The initial cloud diameters varied from 60cm to 300cm.Based on the analysis of experimental data,the quantitative relationship is obtained for the cloud explosion pressure,the cloud radius and the distance from ignition point .Present results provide a useful way to evaluate the building damage caused by unconfined vapor cloud explosions and to determine the indispensable explosion grade in the application of multi-energy model.

  15. Experimental Study onMalignant Transformation of Human Bronchial Epithelial CellsInduced by Glycidyl Methacrylate and Analysis on its Methylation

    Institute of Scientific and Technical Information of China (English)

    WANG An Na; WANG Quan Kai; YANG Min; HU Jie; DONG Lin; andXU Jian Ning

    2014-01-01

    ObjectiveTo establish the model of human bronchial epithelial cells(16HBE) malignant transformation induced by glycidyl methacrylate(GMA)and define the different methylation genes at different stages. MethodsDNA was extracted at different 16HBE malignant phasesandchanges of genes DNA methylation atdifferent stages weredetectedusing Methylation chip of‘NimbleGen HG18 CpG Promoter Microarray Methylation’. Methylation-specific PCR (MSP) was usedto observe the methylation status ofsome genes, and then compared with the control groups. ResultsThe resultshowed that GMA induced 16HBE morphorlogical transformation at the dose of 8µg/mL, and cell exposed to GMA had 1374 genes in protophase, 825 genes inmetaphase, 1149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not inmetaphase and anaphase; 272 genes in metaphase but not inprotophase and anaphase; 683 genes in anaphase but not inmetaphase and protophase; 73 genes inprotophase andmetaphase but not in anaphase; 67 genes in protophase and anaphase but not inmetaphase; 59 genes inmetaphase and anaphase but not in protophase. ConclusionThe pattern of DNA methylation could change in the process of 16HBEinduced by GMA.

  16. Experimental study on therapeutic effect of in vivo expression of Cell I-Hep II recombinant polypeptide of fibronectin on murine H22 hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Gui-Mei Zhang; Yan Yang; Bo Huang; Hui Xiao; Dong Li; Zuo-Hua Feng

    2003-01-01

    AIM: To investigate the inhibitory effect of in vivo expression of expressing plasmid pCH510 of recombinant fibronectin polypeptide (CH50) on hepatocellular carcinoma and the improved therapeutic effect of pCH510 in combination with chemotherapeutic agents and Hsp70-H22 hepatocarcinoma antigen peptide on tumor.METHODS: Mice were inoculated with H22 hepatocarcinoma ceils. The chemotactic effect of the expression of plasmid pCH510 on immunocytes was observed after in vivo transfection, tissue slicing and HE staining. Inhibitory effect of transfection with pCH510 on murine tumor originated from different inoculative doses was observed. The inhibitory effect of immediate transfection with pCH510after chemotherapy on tumor was compared with that of transfection 5 days after chemotherapy. The change of function and amount of mouse peritoneal macrophages and the peripheral blood immunocytes resulted from administration of chemotherapeutic agents were detected. The peptides mixture was prepared from H22hepatocarcinoma cells. pCH510 + Hsp70-H22 antigen peptides were injected into tumor-bearing mice with or without chemotherapy, to observe the inhibitory effects on tumor.RESULTS: At the tumor tissue site injected with pCH510,there were a great number of immunocytes which mainly were macrophages, lymphocytes and neutrophils.Transfection of plasmid pCH510 inhibited significantly the murine tumor induced by different inoculative doses. The inhibitory effect was negatively correlated with the inoculative dose. The therapeutic effect was not improved by immediate transfection with pCH510 after chemotherapy, but was significantly improved by transfection with pCH510 5 days after chemotherapy. Chemotherapeutic agent decreased the number of immunocytes and suppressed their activation in vivo. After injection of drug, the amount of immunocytes was the lowest from d 1 to d 3 and returned to normal level on the 10th day. Transfection with plasmid pCH510 alone could inhibit tumor

  17. Endostar combined with cryoablation for subcutaneous xenografted tumor model of lung adenocarcinoma cell line A549 in BALB/c nude mice: an experimental study

    International Nuclear Information System (INIS)

    Objective: To investigate the inhibitory effect of Endostar combined with cryoablation on Lung adenocarcinoma cell line A549 in BALB/c nude mice, and to discuss its interaction mechanisms. Methods: The lung adenocarcinoma A549 model in BALB/c nude mice were established. When the largest diameter of tumor reached 1.0 cm, a total of 24 mice were randomly and equally divided into 4 groups: control group, Endostar group, cryoablation group and cryoablation plus Endostar group. The largest diameter and the vertical diameter of the tumors were measured at different points of time after treatment. At the 21st day, the mice were sacrificed and the tumors were removed and the rate of tumor cell apoptosis, the microvessel density (MVD) and the expression level of vascular endothelial growth factor (VEGF) were determined by using immunohistochemistry method. The results were statistically analyzed. Results: The tumor growth velocity of the control group, Endostar group, cryoablation group and cryoablation plus Endostar group was (2.36.68±51.23)%, (220.02±30.61)%, (159.46±29.33)% and (103.34±25.50)%, respectively (P<0.01). The rate of apoptosis of the four groups was (21.67±2.34)%, (22.17±1.47)%, (38.33±1.37)% and (49.17±1.72)%, respectively (P<0.01). The MVD and the expression levels of VEGF of the cryoablation plus Endostar group were significantly lower than those of the other three groups (P<0.01). Statistical analysis revealed that a positive correlation existed between the express of VEGF and MVD. Conclusion: Endostar can obviously enhance the therapeutic efficacy of cryoablation on lung adenocarcinoma A549 in BALB/c nude mice. The underlying mechanisms may be the Endostar-inhibited angiogenesis through down-regulating the expression of VEGF, and the cooperative effect of Endostar and cryoablation on the promotion of tumor cell apoptosis. (authors)

  18. 大鼠骨髓基质细胞培养的实验研究%Experimental Study and Identification of Rat Bone Marrow Stromal Cell Culture

    Institute of Scientific and Technical Information of China (English)

    张昕

    2010-01-01

    目的 探讨利用骨髓基质细胞体外培养获得神经干细胞的方法及应用.方法 体外培养大鼠骨髓基质细胞;免疫组化检测;流式细胞仪检测.结果 加BME的骨髓基质细胞大量分裂,形成大量的细胞分裂球,传到4代时,90%以上的细胞表达Nestin阳性.结论 BME对骨髓基质细胞有明显的促分裂作用,应用此种方法可获得神经干细胞(Neural stem cell,NSC).

  19. [Brackets and friction in orthodontics: experimental study].

    Science.gov (United States)

    Ben Rejeb Jdir, Saloua; Tobji, Samir; Turki, Wiem; Dallel, Ines; Khedher, Nedra; Ben Amor, Adel

    2015-09-01

    Many authors have been involved in developing brackets in order to improve the quality, stability, speed and efficiency of orthodontic treatment. In order to reduce friction between bracket and archwire, new therapeutic approaches have been devised based on novel technologies. Among these innovative techniques, self-ligating brackets are increasingly popular. SLBs can be classified into several categories according to their mode of action and their materials. We performed an experimental study to compare the friction forces generated during the sliding of orthodontic archwires made from various alloys through conventional and self-ligating brackets. Results show the favorable influence of SLBs, compared to conventional systems using elastomeric or metal ligatures, on the level of friction, particularly when shape-memory Ni-Ti archwires are used. PMID:26370596

  20. Experimental studies on ozonation of ethylenethiourea

    Institute of Scientific and Technical Information of China (English)

    Xinyu Dong; Junwang Meng; Bo Yang; Yang Zhang; Jie Gan; Xi Shu; Jinian Shu

    2011-01-01

    The experimental study on ozonation of ethylenethiourea (ETU) is conducted. The reaction of gas-phase ETU with 0.63 × l06 mol/L ozone is carried out in a 200-L reaction chamber. The secondary organic aerosol (SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size (SMPS). The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days. The ozonation of dry ETU particles, ETU-contained water droplets and ETU aqueous solution is investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUVATOFMS). The formation of 2-imidazoline is observed in the ozonation of dry ETU particles and ETU-contained water droplets. The formation of 2-imidazoline and ethylenerea is observed in the ozonation of ETU aqueous solution.

  1. Experimental Study on Scours Downstream of Floodgates

    Institute of Scientific and Technical Information of China (English)

    张玮; 陈锡林; 徐金环; 李国臣; 王志谦

    2000-01-01

    The river reach downstream of a floodgate at the estuary of the Xinyihe River is about 1.3km long, and the riverbed is composed of clotty clay. In the experiment, soil samples are taken from the construction site, and the incipient velocity is determined in a laboratory flume, and it is used to design the scour model and to select model sand material. The experimental results show that scours below the floodgate is unavoidable due to large discharge and low tidal level. Scours is caused by two factors: the rapid flow passing though the floodgate and the water drop near the river mouth during low tide, and the scour below the floodgate is more critical to the structural design. It is suggested that anti-scour walls should be used instead of riprap. The ideas and methods adopted in the experiment can be used as reference in the study on river scour under similar conditions.

  2. Cognitive network structure: an experimental study

    CERN Document Server

    Guazzini, Andrea; Bagnoli, Franco; Carletti, Timoteo; Grotto, Rosapia Lauro

    2012-01-01

    In this paper we present first experimental results about a small group of people exchanging private and public messages in a virtual community. Our goal is the study of the cognitive network that emerges during a chat seance. We used the Derrida coefficient and the triangle structure under the working assumption that moods and perceived mutual affinity can produce results complementary to a full semantic analysis. The most outstanding outcome is the difference between the network obtained considering publicly exchanged messages and the one considering only privately exchanged messages: in the former case, the network is very homogeneous, in the sense that each individual interacts in the same way with all the participants, whilst in the latter the interactions among different agents are very heterogeneous, and are based on "the enemy of my enemy is my friend" strategy. Finally a recent characterization of the triangular cliques has been considered in order to describe the intimate structure of the network. E...

  3. [Endodontics in horses. An experimental study].

    Science.gov (United States)

    Garcia, F; Sanromán, F; Llorens, M P

    1990-04-01

    A total of 44 experimental endodontic treatments were performed in incisors of eight horses of different ages. Four different endodontic pastes were used: Cloropercha, AH26 De Trey, Eugenol-Endometasone, and Universal N2. Gutta-percha points were also included in the last two treatments. Access to the pulp cavity of incisors was gained through their vestibular and occlusal faces. Holes drilled in vestibular faces were sealed with composite and those drilled in occlusal faces were sealed with Amalgama. Animals were observed during eighteen months at least after endodontics. Radiographic controls were done just after surgery and before slaughtering. Treated incisors and alveoli were studied histopathologically. During the experiment all animals were in good condition. They ate apparently without trouble, and neither clinical nor radiological signs were present.

  4. Lipid peroxidation in experimental uveitis: sequential studies.

    Science.gov (United States)

    Goto, H; Wu, G S; Chen, F; Kristeva, M; Sevanian, A; Rao, N A

    1992-06-01

    Previously we have detected the occurrence of retinal lipid peroxidation initiated by phagocyte-derived oxygen radicals in experimental autoimmune uveitis (EAU). In the current studies, the confirmation of inflammation-mediated lipid peroxidation was proceeded further to include measurement of multiple parameters, including conjugated dienes, ketodienes, thiobarbituric acid reactive substances and fluorescent chromolipids. The assay for myeloperoxidase, a measure for the number of polymorphonuclear leukocytes in the inflammatory sites was also carried out. The levels of all these parameters were followed through the course of EAU development. The sequential evaluation of histologic changes using both light and electron microscopy was also carried out and the results were correlated with lipid peroxidation indices. These data suggest that the retinal lipid peroxidation plays a causative role in the subsequent retinal degeneration.

  5. Simulation and Experimental Studies on Composite Beams

    Directory of Open Access Journals (Sweden)

    M. Abhinay

    2014-09-01

    Full Text Available A composite beam a one dimensional structure or a rod all of them are sectional dimensions in which width and height are much smaller in comparison to the structure. In structural applications longer beams are more frequently used. In this work a composite beam is manufactured with glass and epoxy combination. And stress analysis is carried out using derived analytical expressions. This research work carried out will enable to determine the beam strength due to bending loads. The importance of fiber reinforcement in the manufacturing of the beam is studied in terms of bending strength of the beam. Mat lab codes are generated to implement analytical equations of the composite beam. The analytical results are validated by performing experiments on composite beams. In this investigation, two different composite beams have been tested and compared the experimental results with the analytical results.

  6. Pancreatic and pulmonary mast cells activation during experimental acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Inmaculada; Lopez-Font; Sabrina; Gea-Sorlí; Enrique; de-Madaria; Luis; M; Gutiérrez; Miguel; Pérez-Mateo; Daniel; Closa

    2010-01-01

    AIM:To study the activation of pancreatic and pulmonary mast cells and the effect of mast cell inhibition on the activation of peritoneal and alveolar macrophages during acute pancreatitis.METHODS:Pancreatitis was induced by intraductal infusion of 5% sodium taurodeoxycholate in rats.The mast cell inhibitor cromolyn was administered intraperitoneally(i.p.) 30 min before pancreatitis induction.The pancreatic and pulmonary tissue damage was evaluated histologically and mast cells and their state of activation...

  7. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut

    1997-12-31

    This thesis studies the separation of gas mixtures in a reflux condenser. also called a dephlegmator. Reflux condensation is separation of a gas mixture, in reflux flow with condensing liquid, under continuous heat removal. A numerical model of a dephlegmator for binary mixtures was developed. The model may readily be extended to multi-component mixtures, as the solution method is based on a matrix solver. Separation of a binary mixture in a reflux condenser test rig is demonstrated. The test facility contains a single-tube test section that was designed and built as part of the project. Test mixtures of propane and n-butane were used, and a total of 15 experiments are reported. Limited degree of separation was achieved due to limited heat transfer area and narrow boiling point range of the test mixture. The numerical model reproduces the experimental data within reasonable accuracy. Deviation between calculated and measured properties is less than 6% of the measured temperature and less than 5% of the measured flow rate. The model is based on mechanistic models of physical processes and is not calibrated or tuned to fit the experimental data. The numerical model is applied to a number of separation processes. These case studies show that the required heat transfer area increases rapidly with increments in top product composition (light component). Flooding limits the amount of reflux liquid. The dephlegmator is suitable for separation of feed mixtures that are rich in light components. The gliding temperature in the dephlegmation process enables utilization of top product as refrigerant, with subsequent energy saving as a result. 61 refs., 50 figs., 34 tabs.

  8. Studies of experimental bladder tumors, 3

    International Nuclear Information System (INIS)

    Enzymatologic, histochemical and histologic investigations were performed on the effects of SLA, a β-glucoronidase inhibitor, and Linaic irradiation in an experimental BBN bladder tumor of rats. Bladder tumors were macroscopically thumb-head size in the cases with no treatment of with SLA application, but were shrunk by roentgen irradiation. The number of the rats with reduced tumor was respectively 3 in the group with roentgen irradiation. S-LDH activity of the cancer-carrying animals was markedly elevated as compared with that of the normal rat. SLA application caused no change in S-LDH activity of cancer-carrying animals, but roentgen irradiation resulted in a marked decrease in S-LDH activity of the similar animals with bladder tumors. The level of this decrease was dependent on the dosage of one time irradiation; no change was observed by 200, 300 and 500 rad, little decrease was seen by 750 rad, and marked decrease was observed after 1,000 and 1,500 rad radiation. Histological observation of the effects of irradiation could be summarized as follows. Histological changes were seen in the cases of macroscopic shrinkage by 3,000 rad irradiation. In this group, an individual variation was noticed not only macroscopically but microscopically. One time irradiation of 200, 300 and 500 rad resulted in no histological change, but that of 750, 1,000, and 1,500 rad caused a slight, but not marked, histological change. Tissue distribution of β-glucuronidase was examined by means of Naphthol-AS-BI-glucuronide method in the group without any treatment and the group with SLA administration. β-glucuronidase activity was noticed in the epithelial cells and interstitial stroma of the tumor tissue, but the effect of SLA on β-glucuronidase activity was not observed histochemically. (author)

  9. An experimental study of nerve bypass graft

    Institute of Scientific and Technical Information of China (English)

    XU Jie; LI Xue-shi

    2008-01-01

    Objective: To study the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity. Methods: A sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained. Results: Nerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s±5.83 m/s vs. 54.88 m/s±4.79m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself. Conclusion: Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

  10. An Experimental Study on Effects of Distilled White-ginseng Herbal Acupuncture on A549 human ephithelial lung cancer cell in vitro and implanted Sarcoma-180 in vivo

    Directory of Open Access Journals (Sweden)

    Jong-Seong We

    2004-12-01

    Full Text Available Objectives : In order to investigate effects and immune improvement of distilled white-ginseng herbal extract, expression of Cox-1, Cox-2, and mRNA of Bcl-2 and Bax were analyzed in A549 cell in vivo. Survival time and expression of cytokine mRNA were measured for the mice with Sarcoma-180 induced abdominal cancer. Methods : Balb/c mouse was treated with distilled white-ginseng Herbal Acupuncture at Wisu(BL21 and Chung-wan(CV12 to investigate anti-cancer effects and immune response. Results : 1. For expression of mRNA of Cox-1 using RT-PCR, the control group and the experiment groups show significant increase. For Cox-2, both experiment groups and the normal group showed significant decrease. For Bcl-2, experiment groups showed slight decrease compared to the control group. For Bax, no significant changes were shown between the control group and experiment groups. 2.For survival time, all of experiment groups didn't show significant differences. 3.For IL-2 productivity using Flow cytometry, experiment group I didn't show any significance, For IL-4, all of experiment groups showed slight decrease compared to the control group. 4. For IL-2 productivity using ELISA, experiment groupI showed slight decrease compared to the control group, experiment group II didn't show any significance. 5.For expression of cytokine mRNA using RT-PCR, significant increase of IL-2 and IL-4 were witnessed in the experiment groupI compared to the control group. Significant decrease of IL-10 was shown in all of experiment groups compared to the control group. Conclusion : According to the results, we can expect that distilled white-ginseng Herbal Acupuncture may be further effects in anti-cancer and immune improvement if increasing concentration.

  11. An Experimental Study on Effects of Distilled Red-ginseng Herbal Acupuncture on A549 human ephithelial lung cancer cell in vitro and implanted Sarcoma-180

    Directory of Open Access Journals (Sweden)

    Seung Hwan Won

    2004-06-01

    Full Text Available Objectives : In order to investigate effects and immune improvement of distilled red-ginseng herbal Acupuncture, expression of Cox-1, Cox-2, and mRNA of Bcl-2 and Bax were analyzed in A549 cell in vivo. Survival time and expression of cytokine mRNA were measured for the mice with Sarcoma-180 induced abdominal cancer. Methods : Balb/c mouse was treated with distilled red-ginseng Herbal Acupuncture at Wisu(BL21 and Chung- wan(CV12 to investigate anti-cancer effects and immune response. Results : 1. For expression of mRNA of Cox-1 using RT-PCR, the control group and the experiment groups didn't show significant differences. For Cox-2, both experiment groups and the normal group showed significant decrease. 2.For expression of mRNA of Bcl-2 using RT-PCR, experiment groups showed slight decrease compared to the control group. For Bax, no significant changes were shown between the control group and experiment groups. 3.For survival time, all of experiment groups showed 11.1 % increase compared to the control group. 4. For IL-2 and IL-4 productivity using Flow cytometry, all of experiment groups didn't show any significance. 5.For IL-2 productivity using ELISA, all of experiment groups didn't show any significance. 6.For expression of cytokine mRNA using RT-PCR, significant increase of IL-2 and IL-4 were witnessed in the experiment group II compared to the control group. Significant increase of IL-10 was shown in all of experiment groups compared to the control group. Conclusion : According to the results, we can expect that distilled red-ginseng Herbal Acupuncture may be further effects in anti-cancer and immune improvement if increasing concentration.

  12. Optogenetic cell control in experimental models of neurological disorders.

    Science.gov (United States)

    Tønnesen, Jan

    2013-10-15

    The complexity of the brain, in which different neuronal cell types are interspersed and complexly interconnected, has posed a major obstacle in identifying pathophysiological mechanisms underlying prevalent neurological disorders. This is largely based in the inability of classical experimental approaches to target defined neural populations at sufficient temporal and spatial resolution. As a consequence, effective clinical therapies for prevalent neurological disorders are largely lacking. Recently developed optogenetic probes are genetically expressed photosensitive ion channels and pumps that in principal overcome these limitations. Optogenetic probes allow millisecond resolution functional control over selected optogenetically transduced neuronal populations targeted based on promoter activity. This optical cell control scheme has already been applied to answer fundamental questions pertaining to neurological disorders by allowing researchers to experimentally intercept, or induce, pathophysiological neuronal signaling activity in a highly controlled manner. Offering high temporal resolution control over neural activity at high cellular specificity, optogenetic tools constitute a game changer in research aiming at understanding pathophysiological signaling mechanisms in neurological disorders and in developing therapeutic strategies to correct these. In this regard, recent experimental work has provided new insights in underlying mechanisms, as well as preliminary proof-of-principle for optogenetic therapies, of several neurological disorders, including Parkinson's disease, epilepsy and progressive blindness. This review synthesizes experimental work where optogenetic tools have been applied to explore pathologic neural network activity in models of neurological disorders. PMID:23871610

  13. Theoretical and Experimental Studies of Radiative Shocks

    Science.gov (United States)

    Michaut, C.; Vinci, T.; Boireau, L.; Koenig, M.; Bouquet, S.; Benuzzi-Mounaix, A.; Osaki, N.; Herpe, G.; Falize, E.; Loupias, B.; Atzeni, S.

    2007-01-01

    This paper deals with the radiative shock from both theoretical and numerical points of view. It is based on the whole experimental results obtained at Laboratoire d'Utilisation des Lasers Intenses (LULI, École Polytechnique). Radiative shocks are high-Mach number shocks with a strong coupling between radiation and hydrodynamics which leads to a structure governed by a radiative precursor. These shocks are involved in various astrophysical systems: stellar accretion shocks, pulsating stars, interaction between supernovae and the interstellar medium. In laboratory, these radiative shocks are generated using high power lasers. New diagnostics have been implemented to study the geometrical shape of the shock and the front shock density. Data were obtained varying initial conditions for different laser intensities and temperature. The modeling of these phenomena is mainly performed through numerical simulations (1D and 2D) and analytical studies. We exhibit results obtained from several radiative hydrodynamics codes. As a result, it is possible to discuss about the influence of the geometry and physical parameters introduced in the 1D and 2D models.

  14. Imaging retinal ganglion cells: enabling experimental technology for clinical application.

    Science.gov (United States)

    Smith, Corey A; Chauhan, Balwantray C

    2015-01-01

    Recent advances in clinical ophthalmic imaging have enhanced patient care. However, the ability to differentiate retinal neurons, such as retinal ganglion cells (RGCs), would advance many areas within ophthalmology, including the screening and monitoring of glaucoma and other optic neuropathies. Imaging at the single cell level would take diagnostics to the next level. Experimental methods have provided techniques and insight into imaging RGCs, however no method has yet to be translated to clinical application. This review provides an overview of the importance of non-invasive imaging of RGCs and the clinically relevant capabilities. In addition, we report on experimental data from wild-type mice that received an in vivo intravitreal injection of a neuronal tracer that labelled RGCs, which in turn were monitored for up to 100 days post-injection with confocal scanning laser ophthalmoscopy. We were able to demonstrate efficient and consistent RGC labelling with this delivery method and discuss the issue of cell specificity. This type of experimental work is important in progressing towards clinically applicable methods for monitoring loss of RGCs in glaucoma and other optic neuropathies. We discuss the challenges to translating these findings to clinical application and how this method of tracking RGCs in vivo could provide valuable structural and functional information to clinicians. PMID:25448921

  15. SD大鼠骨髓基质干细胞体外诱导成骨分化实验研究%Experimental study of SD rats bone marrow stromal cells induced into osteoblasts in vitro

    Institute of Scientific and Technical Information of China (English)

    曾铁功; 赵晋英; 黄泽智

    2013-01-01

    目的 探讨SD大鼠骨髓基质干细胞(BMSCs)在体外诱导分化为成骨细胞的实验条件及方法.方法 无菌取SD大鼠股骨骨髓,用全骨髓贴壁法体外培养纯化BMSCs,分为实验组和对照组.实验组采用第3代细胞经含地塞米松、β-甘油磷酸钠和维生素C的成骨诱导液进行诱导,对照组不加诱导液.采用MTT法绘制细胞生长曲线,BCIP/NBT试剂行碱性磷酸酶(ALP)染色,茜素红染色观察钙结节.结果 与对照组比较,实验组大鼠BMSCs经成骨诱导液诱导后,细胞生长缓慢并向成骨细胞发展;实验组ALP染色阳性率为88.34%±8.65%,对照组为28.14%±5.38%,P<0.01;实验组茜素红染色第13天可见橘红色的阳性钙结节,对照组几乎为无色.结论 SD大鼠BMSCs经诱导在体外可稳定地定向分化为成骨细胞.%Objective To study the osteogenic methods and cultural conditions of the SD rats bone marrow stromal cells (BMSCs) induced into osteoblasts in vitro.Methods After obtaining abacterial bone marrow from SD rats femur,the BMSCs were separated and purified by using of whole bone marrow adherent method.Then they were divided into two groups:the experimental group and the control group.In the experimental group,the passage cells of the third generation were cultured in the osteogenic induction medium including dexamethasone,β-sodium glycerophosphate and vitamin C.The growth curve of cultural cells was drawn by MTT colorimetric method.The alkaline phosphatase (ALP) staining of cultural cells was conducted by BCIP/NBT.Calcium tubercle was stained with alizarin bordeaux.The two groups were compared.Results Compared with the control group,the growth velocity of BMSCs cultured in osteogenic induction medium in the experimental group was obviously lower than that in the control group,and BMSCs developed into osteoblasts.The ALP positive rate in the experimental group was 88.34% ±8.65%,and the control group was 28.14% ±5.38% (P<0

  16. Curcumin ameliorates experimental autoimmune myasthenia gravis by diverse immune cells.

    Science.gov (United States)

    Wang, Shan; Li, Heng; Zhang, Min; Yue, Long-Tao; Wang, Cong-Cong; Zhang, Peng; Liu, Ying; Duan, Rui-Sheng

    2016-07-28

    Curcumin is a traditional Asian medicine with diverse immunomodulatory properties used therapeutically in the treatment of many autoimmune diseases. However, the effects of curcumin on myasthenia gravis (MG) remain undefined. Here we investigated the effects and potential mechanisms of curcumin in experimental autoimmune myasthenia gravis (EAMG). Our results demonstrated that curcumin ameliorated the clinical scores of EAMG, suppressed the expression of T cell co-stimulatory molecules (CD80 and CD86) and MHC class II, down-regulated the levels of pro-inflammatory cytokines (IL-17, IFN-γ and TNF-α) and up-regulated the levels of the anti-inflammatory cytokine IL-10, shifted the balance from Th1/Th17 toward Th2/Treg, and increased the numbers of NKR-P1(+) cells (natural killer cell receptor protein 1 positive cells, including NK and NKT cells). Moreover, the administration of curcumin promoted the differentiation of B cells into a subset of B10 cells, increased the anti-R97-166 peptide IgG1 levels and decreased the relative affinity indexes of anti-R97-116 peptide IgG. In summary, curcumin effectively ameliorate EAMG, indicating that curcumin may be a potential candidate therapeutic agent for MG. PMID:27181511

  17. Experimental Study of Gas Hydrate Dynamics

    Science.gov (United States)

    Fandino, O.; Ruffine, L.

    2011-12-01

    Important quantities of methane and other gases are trapped below the seafloor and in the permafrost by an ice-like solid, called gas hydrates or clathrate hydrates. The latter is formed when water is mixing with different gases at high pressures and low temperatures. Due to a their possible use as a source of energy [1] or the problematic related to flow assurance failure in pipelines [2] the understanding of their processes of formation/destabilisation of these structures becomes a goal for many laboratories research as well as industries. In this work we present an experimental study on the stochastic behaviour of hydrate formation from a bulk phase. The method used here for the experiments was to repeat several time the same hydrate formation procedure and to notice the different from one experiment to another. A variable-volume type high-pressure apparatus with two sapphire windows was used. This device, already presented by Ruffine et al.[3], allows us to perform both kinetics and phase equilibrium measurements. Three initial pressure conditions were considered here, 5.0 MPa, 7.5 MPa and 10.0 MPa. Hydrates have been formed, then allowed to dissociate by stepwise heating. The memory effect has also been investigated after complete dissociation. It turned out that, although the thermodynamics conditions of formation and/or destabilization were reproducible. An attempt to determine the influence of pressure on the nucleation induction time will be discussed. References 1. Sum, A. K.; Koh, C. A.; Sloan, E. D., Clathrate Hydrates: From Laboratory Science to Engineering Practice. Industrial & Engineering Chemistry Research 2009, 48, 7457-7465. 2. Sloan, E. D., A changing hydrate paradigm-from apprehension to avoidance to risk management. Fluid Phase Equilibria 2005, 228, 67-74. 3. Ruffine, L.; Donval, J. P.; Charlou, J. L.; Cremière, A.; Zehnder, B. H., Experimental study of gas hydrate formation and destabilisation using a novel high-pressure apparatus. Marine

  18. Experimental Study of Olivine-rich Troctolites

    Science.gov (United States)

    Mu, S.; Faul, U.

    2014-12-01

    This experimental study is designed to complement field observations of olivine-rich troctolites in ophiolites and from mid-ocean ridges. The olivine-rich troctolites are characterized by high volume proportion of olivine with interstitial plagioclase and clinopyroxene. Typically the clinopyroxene occurs in the form of few large, poikilitic grains. The primary purpose of this study is to investigate the effects of cooling process on the geometry of the interstitial phases (clinopyroxene and plagioclase). Experiments are conducted in a piston cylinder apparatus by first annealing olivine plus a basaltic melt with a composition designed to be in equilibrium with four phases at ~ 1 GPa and 1250ºC. Initially, we anneal the olivine-basalt aggregates at 1350 °C and 0.7 GPa for one week to produce a steady state microstructure. At this temperature only olivine and minor opx are present as crystalline phases. We then cool the samples over two weeks below their solidus temperature, following different protocols. The post-run samples are sectioned, polished, and imaged at high resolution and analyzed by using a field emission SEM. Initial observations show that under certain conditions clinopyroxene nucleates distributed throughout the aggregate at many sites, forming relatively small, rounded to near euhedral grains. Under certain conditions few cpx grains nucleate and grow with a poikilitic shape, partially or fully enclosing olivine grains, as is observed in natural samples. As for partially molten aggregates quenched form the annealing temperature, the microstructure will be characterized by tracing phase boundaries on screen by using ImageJ software. The geometry of the interstitial phases will be quantified by determining the grain boundary wetness, in this case the ratio of the length of polyphase to single phase (olivine-olivine) boundaries. Compositional data will also be used to study the change in major element compositions before and after the cooling process.

  19. The experimental studies of thermoacoustic cooler.

    Science.gov (United States)

    Sakamoto, Shin-ichi; Watanabe, Yoshiaki

    2004-04-01

    The experimental studies of thermoacoustic cooler consisting of acoustic loop-tube were carried out. The loop-tube was filled with the mixture of air and helium gas or air at atmospheric pressure. The dimensions of the loop-tube were 3.3 m of length, 44 mm of inner diameter and 4 mm of thickness. A pair of stacks (stack 1 and stack 2) which were sandwiched between two heat exchangers was placed symmetrically in the loop-tube. Stack 1 was employed as a prime mover and stack 2 as a heat pump. The self-sustained sound generated by the thermoacoustic effect and the cooling phenomena at the stack 2 were observed. The distribution of the sound pressures and the waveforms in the loop-tube were measured, and the frequency component of the self-sustained sound was investigated at the starting phase. The fundamental frequency component was confirmed and it was developing as the sound pressure increasing. The higher harmonics frequency components were generated and they were also developing. PMID:15047261

  20. Experimental study of finite Larmor radius effects

    International Nuclear Information System (INIS)

    Linear Z-pinches in Ar, Kr, Xe, N2, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 1015/cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 μsec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 μF, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption

  1. Contact freezing: a review of experimental studies

    Directory of Open Access Journals (Sweden)

    L. A. Ladino Moreno

    2013-10-01

    Full Text Available This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complete theory that describes contact freezing and how the energy barrier has to be overcome to nucleate an ice crystal by contact freezing. Experiments on contact freezing conducted using the cold plate technique indicate that it can initiate ice formation at warmer temperatures than immersion freezing. Additionally, a qualitative difference in the freezing temperatures between contact and immersion freezing has been found using different instrumentation and different ice nuclei. There is a lack of data on collision rates in most of the reported data, which inhibits a quantitative calculation of the freezing efficiencies. Thus, new or modified instrumentation to study contact nucleation in the laboratory and in the field are needed to identify the conditions at which contact nucleation could occur in the atmosphere. Important questions concerning contact freezing and its potential role for ice cloud formation and climate are also summarized.

  2. Bone and parathyroid inhibitory effects of S-2(3-aminopropylamino)ethylphosphorothioic acid. Studies in experimental animals and cultured bone cells

    International Nuclear Information System (INIS)

    S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR 2721) is a radio- and chemoprotective agent which produces hypocalcemia in humans. Intravenous injection of 30 mg/kg WR 2721 in rats and 15 mg/kg in dogs lowers serum calcium by 19 and 25%, respectively. Hypocalcemia in dogs is associated with a fall in serum immunoreactive parathyroid hormone (PTH), which suggests that the mechanism of its hypocalcemic effect is acute hypoparathyroidism. Despite this effect on PTH, in eight chronically parathyroidectomized rats on a low phosphate diet, WR 2721 reduced serum calcium from 9.4 to 7.7 mg/dl at 3 h. Furthermore, in dogs rendered hypercalcemic by continuous infusion of PTH, WR 2721 reduced serum calcium from 11.0 to 10.6 mg/dl. To determine whether WR 2721 causes hypocalcemia by enhancing the exit of calcium from the circulation or inhibiting its entry, the drug was infused 3 h after administration of 45Ca to rats. WR 2721 did not significantly increase the rate of disappearance of 45Ca from the circulation even though serum calcium fell by 19%. In incubations with fetal rat long bone labeled in utero with 45Ca, 10(-3) M WR 2721 inhibited PTH-stimulated, but not base-line release of 45Ca. Bone resorption by primary culture of chick osteoclasts was inhibited by WR 2721 at concentrations as low as 10(-4) M in the absence of hormonal stimulation. These studies suggest that WR 2721 lowers serum calcium predominantly by blocking calcium release from bone. This acute hypocalcemic effect is at least in part independent of its effect on the parathyroid glands, and is most likely a direct effect of the agent on bone resorption

  3. Experimental and Numerical Study of Damaged Cantilever

    DEFF Research Database (Denmark)

    Rytter, A.; Krawczuk, M.; Kirkegaard, Poul Henning

    2000-01-01

    of the results from experimental and numerical tests with hollow section cantileves containing fatigue cracks. Two different finite-element (FE) models have been used to estimate the modal parameters numerically. The first FE model consists of beam elements. The second FE model consists of traditional...... rectangular shell elements and one rectangular shell element with a transverse, internal, open crack. The analytical results from the numerical models are compared with data obtained from experimental tests. The numerical models give good agreements with the experimental data. The beam model takes...

  4. Learning, forecasting and optimizing : An experimental study

    NARCIS (Netherlands)

    Bao, Te; Duffy, John; Hommes, Cars

    2013-01-01

    Rational Expectations (RE) models have two crucial dimensions: (i) agents on average correctly forecast future prices given all available information, and (ii) given expectations, agents solve optimization problems and these solutions in turn determine actual price realizations. Experimental tests o

  5. Learning, forecasting and optimizing: an experimental study

    NARCIS (Netherlands)

    T. Bao; J. Duffy; C. Hommes

    2011-01-01

    Rational Expectations (RE) models have two crucial dimensions: 1) agents correctly forecast future prices given all available information, and 2) given expectations, agents solve optimization problems and these solutions in turn determine actual price realizations. Experimental testing of such model

  6. Learning, forecasting and optimizing: an experimental study

    NARCIS (Netherlands)

    T. Bao; J. Duffy; C. Hommes

    2013-01-01

    Rational Expectations (RE) models have two crucial dimensions: (i) agents on average correctly forecast future prices given all available information, and (ii) given expectations, agents solve optimization problems and these solutions in turn determine actual price realizations. Experimental tests o

  7. Evapotranspiration studies for protective barriers: Experimental plans

    International Nuclear Information System (INIS)

    This document describes a general theory and experimental plans for predicting evapotranspiration in support of the Protective Barrier Program. Evapotranspiration is the combined loss of water from plants and soil surfaces to the atmosphere. 45 refs., 1 fig., 4 tabs

  8. Experimental and computational studies of nanofluids

    Science.gov (United States)

    Vajjha, Ravikanth S.

    The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al2O3), copper oxide (CuO) and silicon dioxide (SiO2) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number

  9. Experimental Study of Yishou Tiaozhi Tablet(

    Institute of Scientific and Technical Information of China (English)

    ZHONG; Yi

    2001-01-01

    [1]XU SY. Screening method on lowering lipid drug and inhibiting arteriosclerosis drug. Pharmacological Experimental Methodology. Beijing: The People's Health Publishing House, 1985∶781-783.[2]LI YL. Assay of alkali hydrolytic decomposition method on serum HYP determination. Clinical Journal of Decimology 1988;6(2)∶69-71.[3]LI ZJ, HAN CS, WANG JX. Practical Radioimmunology. Beijing: The Scientific Technological Archive Publishing House, 1989∶198-221.[4]GAO YC. Effect of Yixing decoction on rats' serum lipid level in hyperlipidemia and its mechanism. Academic Journal of Traditional Chinese Medicine 1990;(5)∶53-56.[5]Manninen V, Tenkanen L. Lipid alteration and decline in the incidence of coronary heart disease in the Helsinki Heart Study. JAMA 1988;260∶641-651.[6]HUANG JG, translated. The atherosclerous lipid marker. Fascicle of Cardiovascular Disease in Journal of Foreign Medicine 1987;14(1)∶4-9.[7]YANG RX. Lp(a) and atherosclerosis. Journal of Progression on Cardiovascular Disease 1994;15(4)∶221-223.[8]Colin J, Schwartz MD. A modern view of atherogenesis. Am J Cardio 1993;71∶9B-14B.[9]LIN XQ. Exploration on relationship between HYP and atherosclerosis in hyperlipidemia. Journal of Chinese Circulation 1993;8(3)∶160-163.[10].CHEN SH. Hyperlipidemia and platelet high response. Fascicle of Cardiovascular Disease in Journal of Foreign Medicine 1989;16(5)∶257-262.

  10. Creativity and the homospatial process. Experimental studies.

    Science.gov (United States)

    Rothenberg, A

    1988-09-01

    Through empirical studies involving intensive and extensive interviewing of outstanding creative persons in literature, visual art, and science, a specific creative cognitive operation involving complex mental imagery was identified. This operation has been designated the "homospatial process" and defined as actively conceiving two or more discrete entities occupying the same space, a conception leading to the articulation of new identities. Four experimental assessments involving exposure to stimuli designed to evoke the homospatial process have been carried out with groups of talented persons as follows: (1) 43 writers produced short poetic metaphors in response to 10 different pairs of slide stimuli. Subjects were randomly assigned to view the pairs either superimposed upon one another, and thereby appearing to occupy the same spatial location, or separated and side by side on the screen as a control condition. (2) 46 writers were similarly divided and exposed for a shortened period of time to the same stimuli in order to encourage mental elaboration in the creation of poetic metaphors. (3) Drawings were created by 43 artists separated into a group exposed to three superimposed images and a control group exposed to the same component images side by side. (4) 39 artists were separated into a group exposed to three superimposed images and a control group exposed to the same images constructed into a single-image figure-ground display. Findings were that, in all four experiments, subjects' productions in response to the superimposed visual stimuli were rated significantly higher in creativity, by independent experts, than productions in response to the control condition. Therefore, the externalized representations of the homospatial process facilitated both literary and artistic creativity.

  11. Experimental techniques for single cell and single molecule biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Lim, C.T. [Nano Biomechanics Laboratory, Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)]. E-mail: ctlim@nus.edu.sg; Zhou, E.H. [Nano Biomechanics Laboratory, Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Li, A. [Nano Biomechanics Laboratory, Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Vedula, S.R.K. [Nano Biomechanics Laboratory, Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Fu, H.X. [Nano Biomechanics Laboratory, Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)

    2006-09-15

    Stresses and strains that act on the human body can arise either from external physical forces or internal physiological environmental conditions. These biophysical interactions can occur not only at the musculoskeletal but also cellular and molecular levels and can determine the health and function of the human body. Here, we seek to investigate the structure-property-function relationship of cells and biomolecules so as to understand their important physiological functions as well as establish possible connections to human diseases. With the recent advancements in cell and molecular biology, biophysics and nanotechnology, several innovative and state-of-the-art experimental techniques and equipment have been developed to probe the structural and mechanical properties of biostructures from the micro- down to picoscale. Some of these experimental techniques include the optical or laser trap method, micropipette aspiration, step-pressure technique, atomic force microscopy and molecular force spectroscopy. In this article, we will review the basic principles and usage of these techniques to conduct single cell and single molecule biomechanics research.

  12. Retrievable IVC Square Stent Filter: Experimental Study

    International Nuclear Information System (INIS)

    experimental and eventual clinical studies with a commercially manufactured SSF

  13. Grb2 Is Important for T Cell Development, Th Cell Differentiation, and Induction of Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Radtke, Daniel; Lacher, Sonja M; Szumilas, Nadine; Sandrock, Lena; Ackermann, Jochen; Nitschke, Lars; Zinser, Elisabeth

    2016-04-01

    The small adaptor protein growth factor receptor-bound protein 2 (Grb2) modulates and integrates signals from receptors on cellular surfaces in inner signaling pathways. In murine T cells, Grb2 is crucial for amplification of TCR signaling. T cell-specific Grb2(fl/fl) Lckcre(tg) Grb2-deficient mice show reduced T cell numbers due to impaired negative and positive selection. In this study, we found that T cell numbers in Grb2(fl/fl) CD4cre(tg) mice were normal in the thymus and were only slightly affected in the periphery. Ex vivo analysis of CD4(+) Th cell populations revealed an increased amount of Th1 cells within the CD4(+) population of Grb2(fl/fl) CD4cre(tg) mice. Additionally, Grb2-deficient T cells showed a greater potential to differentiate into Th17 cells in vitro. To test whether these changes in Th cell differentiation potential rendered Grb2(fl/fl) CD4cre(tg) mice more prone to inflammatory diseases, we used the murine Th1 cell- and Th17 cell-driven model of experimental autoimmune encephalomyelitis (EAE). In contrast to our expectations, Grb2(fl/fl) CD4cre(tg) mice developed a milder form of EAE. The impaired EAE disease can be explained by the reduced proliferation rate of Grb2-deficient CD4(+) T cells upon stimulation with IL-2 or upon activation by allogeneic dendritic cells, because the activation of T cells by dendritic cells and the subsequent T cell proliferation are known to be crucial factors for the induction of EAE. In summary, Grb2-deficient T cells show defects in T cell development, increased Th1 and Th17 cell differentiation capacities, and impaired proliferation after activation by dendritic cells, which likely reduce the clinical symptoms of EAE.

  14. Computatonal and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, M.D.; Long, M.B. [Yale Univ., New Haven, CT (United States)

    1993-12-01

    This research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in counterflow, cylindrical and coflowing axisymmetric configurations. The authors have pursued both computational and experimental aspects of the research in parallel. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the one and two-dimensional nonlinear boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. In particular, spontaneous Raman scattering and laser induced fluorescence were used to measure the temperature, major and minor species profiles.

  15. Immune Cells and Molecular Networks in Experimentally Induced Pulpitis.

    Science.gov (United States)

    Renard, E; Gaudin, A; Bienvenu, G; Amiaud, J; Farges, J C; Cuturi, M C; Moreau, A; Alliot-Licht, B

    2016-02-01

    Dental pulp is a dynamic tissue able to resist external irritation during tooth decay by using immunocompetent cells involved in innate and adaptive responses. To better understand the immune response of pulp toward gram-negative bacteria, we analyzed biological mediators and immunocompetent cells in rat incisor pulp experimentally inflamed by either lipopolysaccharide (LPS) or saline solution (phosphate-buffered saline [PBS]). Untreated teeth were used as control. Expression of pro- and anti-inflammatory cytokines, chemokine ligands, growth factors, and enzymes were evaluated at the transcript level, and the recruitment of the different leukocytes in pulp was measured by fluorescence-activated cell-sorting analysis after 3 h, 9 h, and 3 d post-PBS or post-LPS treatment. After 3 d, injured rat incisors showed pulp wound healing and production of reparative dentin in both LPS and PBS conditions, testifying to the reversible pulpitis status of this model. IL6, IL1-β, TNF-α, CCL2, CXCL1, CXCL2, MMP9, and iNOS gene expression were significantly upregulated after 3 h of LPS stimulation as compared with PBS. The immunoregulatory cytokine IL10 was also upregulated after 3 h, suggesting that LPS stimulates not only inflammation but also immunoregulation. Fluorescence-activated cell-sorting analysis revealed a significant, rapid, and transient increase in leukocyte levels 9 h after PBS and LPS stimulation. The quantity of dendritic cells was significantly upregulated with LPS versus PBS. Interestingly, we identified a myeloid-derived suppressor cell-enriched cell population in noninjured rodent incisor dental pulp. The percentage of this population, known to regulate immune response, was higher 9 h after inflammation triggered with PBS and LPS as compared with the control. Taken together, these data offer a better understanding of the mechanisms involved in the regulation of dental pulp immunity that may be elicited by gram-negative bacteria. PMID:26472753

  16. Experimental Study of Effect of Low Power Laser on Telomere Length of Cells%低功率激光对细胞端粒DNA长度影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    黄玲; 吴智辉; 莫华

    2013-01-01

    To investigate the effect of low power helium neon laser (He-Ne laser) on the telomere length of human fetal lung diploid fibroblast (2BS) cell,we used the laser (λ=632.8nm,P=2mW) to treat the young 2BS cells.Cell growth and proliferation was observed through MTT method after treating with low power laser.The relative telomere length of 2BS cells was detected by fluorescence real-time quantitative PCR (q-PCR).The results showed that the cells of the treated groups grew better than the untreated groups.The telomere DNA length of the old 2BS cells,treated by low power He-Ne laser when they were young,was longer than that of untreated group.The results of the present study indicated that the low power He-Ne laser might decrease shortening rate of telomere and delay the aging of cells.Therefore,this study provides the experimental basis for us to further investigate the effect of low power laser on cell aging at the gene level.%本研究目的是探讨低功率氦氖激光对人胚肺二倍体成纤维(2BS)细胞端粒DNA长度的影响.低功率氦氖激光(波长632.8 nm,功率2 mW可调)对年轻2BS细胞进行照射处理,采用四甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞生长和增殖的变化,采用实时荧光定量聚合酶链式反应(q-PCR)方法检测细胞端粒DNA相对长度.结果表明,激光照射组细胞生长趋势均优于非激光照射组(P<0.05);2BS细胞在年轻时经激光照射后传代至老年时的端粒长度较对照组的老年细胞端粒长度长(P<0.05).研究结果提示,经适当激光照射后,细胞端粒DNA因衰老而变短的趋势得到减缓.本研究从基因水平为探讨低功率激光延缓细胞衰老的激光生物效应提供实验依据.

  17. EXPERIMENTAL STUDIES ON FELDSPAR ORE CONCENTRATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of Fe2O3-elimination experiments were conducted on feldspar samples from Tangshan Stone-powder Plant. These experimental methods include scrubbing desliming, flotation, rod milling and high gradient magnetic separation. Some technical factors of feldspar concentration and a new technological flow-sheet of ceramics raw material concentration were put forward.

  18. Blast mitigation experimental and numerical studies

    CERN Document Server

    2013-01-01

    Presents experimental methods of material and structural response to dynamic blast loads Includes computational analysis of material and structural response to dynamic blast loads Offers mitigation measures for structures in various environments Relates lab experiments to larger field tests Features more than 150 illustrations

  19. Standardization of experimental parameters for LLLT studies

    Science.gov (United States)

    Magrini, Taciana D.; Santos, Arnaldo R., Jr.; da Silva Martinho, Herculano

    2012-03-01

    The aim of this work was to create and do characterization of a setup for irradiation of cultured cells with laser light in which light intensity is homogeneous and to create a method for calculating what exactly the quantity of light used in the irradiation is. The characterization was done by evaluating intensity distributions and by evaluation of irradiated in vitro cell viability with different configurations of the apparatus.

  20. Remyelination of the Corpus Callosum by Olfactory Ensheathing Cell in an Experimental Model of Multiple Sclerosis

    OpenAIRE

    Mohammad Azimi Alamouti; Mehrdad Bakhtiyari; Fatemeh Moradi; Tahmineh Mokhtari; Azim Hedayatpour; Fariba Zafari; Mohammad Barbarestani

    2015-01-01

    Multiple Sclerosis (MS) causes loss of the myelin sheath, which leads to loss of neurons. Regeneration of myelin sheath stimulates axon regeneration and neurons’ survival. In this study, olfactory ensheathing cell (OEC) transplantation is investigated to restore myelin sheath in an experimental model of MS in male mice.OECs were isolated from the olfactory mucosa of seven-day-old infant rats and cultured. Then, cells were evaluated and approved by flow cytometry by p75 and GFAP markers. A tot...

  1. Different Roles of Mast Cells in Obesity and Diabetes: Lessons from Experimental Animals and Humans

    OpenAIRE

    Shi, Michael A.; Shi, Guo-Ping

    2012-01-01

    Mast cells (MCs) play an important role in allergic hyperresponsiveness and in defending microorganism infections. Recent studies of experimental animals and humans have suggested that MCs participate in obesity and diabetes. MC distribution and activities in adipose tissues may vary, depending on the locations of different adipose tissues. In addition to releasing inflammatory mediators to affect adipose tissue extracellular matrix remodeling and to promote inflammatory cell recruitment and ...

  2. Experimental and numerical study on scratching test

    OpenAIRE

    Öpöz, Tahsin; Chen, Xun

    2013-01-01

    This paper presents recent investigation of the material removal mechanism in single grit grinding test. Single grit scratches were generated experimentally by using CBN grit on En24T steel and compared with numerical simulation by using finite element modelling (FEM). The material removal mechanism was observed along the scratch length to understand the effectiveness of ploughing and cutting mechanism throughout the scratch. Experiments showed that cutting is efficient at first half of the s...

  3. Experimental study of single span railway bridges

    OpenAIRE

    Rigueiro, Constança; Rebelo, C.; Silva, L. Simões da

    2007-01-01

    The main purpose of this paper is to present some results concerning the investigation that has been done by the authors regarding the dynamic response of small to médium span railway bridges using response acceleration data colleted during the measurements carried out on single span bridges on the railway track Linz-Wels, in Austria. Using output-only methods in this experimental program, it was possible to have an estimation of the igenfrequencies, mode shapes and the corresponding viscous ...

  4. Testing for Team Spirit - An Experimental Study

    OpenAIRE

    Rupert Sausgruber

    2005-01-01

    It is often suggested that team spirit counteracts free-riding. Testing for team spirit with field data is difficult, however, due to an inherent identification problem. In this paper test for team spirit experimentally. In a team work task we vary subjects' information about relative team performance while we leave unchanged the structure of explicit incentives. We find that subjects contribute more to their team's project when teams observe each others' performance. We attribute this result...

  5. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  6. Experimental and numerical studies on standing surface acoustic wave microfluidics.

    Science.gov (United States)

    Mao, Zhangming; Xie, Yuliang; Guo, Feng; Ren, Liqiang; Huang, Po-Hsun; Chen, Yuchao; Rufo, Joseph; Costanzo, Francesco; Huang, Tony Jun

    2016-02-01

    Standing surface acoustic waves (SSAW) are commonly used in microfluidics to manipulate cells and other micro/nano particles. However, except for a simple one-dimensional (1D) harmonic standing waves (HSW) model, a practical model that can predict particle behaviour in SSAW microfluidics is still lacking. Herein, we established a two-dimensional (2D) SSAW microfluidic model based on the basic theory in acoustophoresis and our previous modelling strategy to predict the acoustophoresis of microparticles in SSAW microfluidics. This 2D SSAW microfluidic model considers the effects of boundary vibrations, channel materials, and channel dimensions on the acoustic propagation; as an experimental validation, the acoustophoresis of microparticles under continuous flow through narrow channels made of PDMS and silicon was studied. The experimentally observed motion of the microparticles matched well with the numerical predictions, while the 1D HSW model failed to predict many of the experimental observations. Particularly, the 1D HSW model cannot account for particle aggregation on the sidewall in PDMS channels, which is well explained by our 2D SSAW microfluidic model. Our model can be used for device design and optimization in SSAW microfluidics. PMID:26698361

  7. Experimental studies of coaxial plasma gun current

    International Nuclear Information System (INIS)

    In this investigation of a coaxial plasma gun, plasma sheath currents and related behavior are examined. Plasma behavior in the gun affects gun characteristics. Plasma gun applications are determined by the plasma behavior. The AFWL PUFF capacitor bank (72 μF, 29 nH, 120 kV) drives the plasma gun using a deuterium fill gas. The gas breakdown site is isolated from the dielectric/vacuum interface in the AFWL system. Two gas values deliver gas in the system. The first delivers gas from the gun breech and the second optional valve delivers gas to the gun muzzle. Currents and voltages are measured by Rogowski coils, B probes and capacitive voltage probes. A O-D slug model is used to predict the current, inductance, gun voltage and plasma sheath velocity. The slug model assumes the sheath transits the gun with all mass in the sheath. In the snowplow mode, the plasma sheath is thin with a sharp current rise and drop. Our system operated in a transition mode between the snowplow and deflagration modes with early snowplow behavior and late deflagration behavior. Neutrons are produced in a plasma pinch at the gun muzzle, indicating snowplow behavior. The slug theory models overall gun behavior to experimental accuracy. Experimental results are compared to four theories for plasma sheath velocities: the Alfven collisionally limited model, the Rosenbluth model, the Fishbine saturated model and a single particle drift model. Experimental velocities vary from 105 to 106 m/s. Only the single particle drift and the slug model calculations are of the right magnitude (8 x 105 m/s). The Fishbine and the Rosenbluth models predict slower velocities (2 x 105 m/s). The Alfven model is not applicable to this system

  8. Numerical and experimental calibration of calorimetric sample cell dedicated to nuclear heating measurements

    International Nuclear Information System (INIS)

    Online nuclear measurements inside experimental channels of MTRs are needed for experimental works (to design set-ups) and for numerical works (input data) in order to better understanding complex phenomena occurring during the accelerated ageing of materials and the irradiation of nuclear fuel. In this paper we focus only on one kind of measurements: nuclear heating performed by means of a radiometric calorimeter. The aims of numerical and experimental works are firstly to optimize the sensor response for new energy deposit ranges and then to miniaturize this sensor for JHR irradiation conditions A first calorimeter, developed previously by the CEA, is studied. It corresponds to a graphite differential calorimeter divided into two twin cells (a reference cell, and a sample one). It is used with a non adiabatic mode or heat flow mode. Experimental calibration of the sample cell is presented. In that case, energy deposit is simulated by Joule effect and the sample cell is inserted into a bath at a regulated temperature and controlled flow. The response of the sensor is shown versus electrical power imposed for two flow regimes (intensive or moderated forced convection). These experimental results are compared to numerical works and improvements are discussed. (authors)

  9. Experimental Studies of Ferromagnetism in Topological Insulators

    Science.gov (United States)

    Checkelsky, Joseph

    2014-03-01

    Breaking of time reversal symmetry has proven to be an incisive method for experimentally drawing out the exotic nature of topological insulators. In particular, the introduction of magnetic dopants in to three dimensional topological insulators has led to the realization of theoretically predicted novel types of ferromagnetic order and a quantized version of the anomalous Hall effect. Here, I will present recent work on the synthesis and measurement of bulk and thin film topological insulators doped with 3 d transition metals. I will discuss the ferromagnetic order that arises in various systems and the associated electrical transport response of the surface modes.

  10. Adult Stem Cell as New Advanced Therapy for Experimental Neuropathic Pain Treatment

    Directory of Open Access Journals (Sweden)

    Silvia Franchi

    2014-01-01

    Full Text Available Neuropathic pain (NP is a highly invalidating disease resulting as consequence of a lesion or disease affecting the somatosensory system. All the pharmacological treatments today in use give a long lasting pain relief only in a limited percentage of patients before pain reappears making NP an incurable disease. New approaches are therefore needed and research is testing stem cell usage. Several papers have been written on experimental neuropathic pain treatment using stem cells of different origin and species to treat experimental NP. The original idea was based on the capacity of stem cell to offer a totipotent cellular source for replacing injured neural cells and for delivering trophic factors to lesion site; soon the researchers agreed that the capacity of stem cells to contrast NP was not dependent upon their regenerative effect but was mostly linked to a bidirectional interaction between the stem cell and damaged microenvironment resident cells. In this paper we review the preclinical studies produced in the last years assessing the effects induced by several stem cells in different models of neuropathic pain. The overall positive results obtained on pain remission by using stem cells that are safe, of easy isolation, and which may allow an autologous transplant in patients may be encouraging for moving from bench to bedside, although there are several issues that still need to be solved.

  11. Feasibility study of the AOSTA experimental campaign

    Science.gov (United States)

    Carta, M.; Blaise, P.; Bethaz, C.; Boccia, F.; Fabrizio, V.; Geslot, B.; Grossi, A.; Gruel, A.

    2016-03-01

    The reduction of the nuclear waste is one of the most important nuclear issues. The high radiotoxicity of the spent fuel is due to plutonium and some minor actinides (MAs) such as neptunium, americium and curium, above all. One way to reduce their hazard is to destroy by fission MAs in appropriate nuclear reactors. To allow the MAs destruction an important effort have been done on the nuclear data due to the poor knowledge in this field. In the framework of one of the NEA Expert Group on Integral Experiments for Minor Actinide Management an analysis of the feasibility of MAs irradiation campaign in the TAPIRO fast research reactor is carried out. This paper provides preliminary results obtained by calculations modelling the irradiation, in different TAPIRO irradiation channels, of some CEA samples coming from the French experimental campaign OSMOSE, loaded with different contents of MAs, in order to access, through particular peak spectrometry, to their capture cross section. On the basis of neutron transport calculation results, obtained by both deterministic and Monte Carlo methods, an estimate of the irradiated samples counting levels from the AOSTA (Activation of OSMOSE Samples in TAPIRO) experimental campaign is provided.

  12. Experimental studies of Generalized Parton Distributions

    Science.gov (United States)

    Niccolai, Silvia

    2015-12-01

    Generalized Parton Distributions (GPDs) are nowadays the object of an intense effort of research, in the perspective of understanding nucleon structure. They describe the correlations between the longitudinal momentum and the transverse spatial position of the partons inside the nucleon and they can give access to the contribution of the orbital momentum of the quarks to the nucleon spin. Deeply Virtual Compton scattering (DVCS), the electroproduction on the nucleon, at the quark level, of a real photon, is the process more directly interpretable in terms of GPDs of the nucleon. Depending on the target nucleon (proton or neutron) and on the DVCS observable extracted (cross-sections, target- or beam-spin asymmetries, etc.), different sensitivity to the various GPDs for each quark flavor can be exploited. This article is focused on recent promising results, obtained at Jefferson Lab, on cross-sections and asymmetries for DVCS, and their link to GPDs. These data open the way to a “tomographic” representation of the structure of the nucleon, allowing the extraction of transverse-space densities of the quarks at fixed longitudinal momentum. The extensive experimental program to measure GPDs at Jefferson Lab with the 12 GeV-upgraded electron accelerator and the complementary detectors that will be housed in three experimental Halls (A, B and C), will also be presented.

  13. A Experimental Study of Viscous Vortex Rings.

    Science.gov (United States)

    Dziedzic, Mauricio

    Motivated by the role played by vortex rings in the process of turbulent mixing, the work is focused on the problem of stability and viscous decay of a single vortex ring. A new classification is proposed for vortex rings which is based on extensive hot-wire measurements of velocity in the ring core and wake and flow visualization. Vortex rings can be classified as laminar, wavy, turbulence-producing, and turbulent. Prediction of vortex ring type is shown to be possible based on the vortex ring Reynolds number. Linear growth rates of ring diameter with time are observed for all types of vortex rings, with different growth rates occurring for laminar and turbulent vortex rings. Data on the viscous decay of vortex rings are used to provide experimental confirmation of the accuracy of Saffman's equation for the velocity of propagation of a vortex ring. Experimental data indicate that instability of the vortex ring strongly depends on the mode of generation and can be delayed by properly adjusting the generation parameters. A systematic review of the literature on vortex-ring interactions is presented in the form of an appendix, which helps identify areas in which further research may be fruitful.

  14. Feasibility study of the AOSTA experimental campaign

    Directory of Open Access Journals (Sweden)

    Carta M.

    2016-01-01

    Full Text Available The reduction of the nuclear waste is one of the most important nuclear issues. The high radiotoxicity of the spent fuel is due to plutonium and some minor actinides (MAs such as neptunium, americium and curium, above all. One way to reduce their hazard is to destroy by fission MAs in appropriate nuclear reactors. To allow the MAs destruction an important effort have been done on the nuclear data due to the poor knowledge in this field. In the framework of one of the NEA Expert Group on Integral Experiments for Minor Actinide Management an analysis of the feasibility of MAs irradiation campaign in the TAPIRO fast research reactor is carried out. This paper provides preliminary results obtained by calculations modelling the irradiation, in different TAPIRO irradiation channels, of some CEA samples coming from the French experimental campaign OSMOSE, loaded with different contents of MAs, in order to access, through particular peak spectrometry, to their capture cross section. On the basis of neutron transport calculation results, obtained by both deterministic and Monte Carlo methods, an estimate of the irradiated samples counting levels from the AOSTA (Activation of OSMOSE Samples in TAPIRO experimental campaign is provided.

  15. Experimental design and analysis for accelerated degradation tests with Li-ion cells.

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, Daniel Harvey; Thomas, Edward Victor; Jungst, Rudolph George; Roth, Emanuel Peter

    2003-08-01

    This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The proposed experimental protocol involves a series of accelerated degradation experiments. Through the acquisition of degradation data over time specified by the experimental protocol, an unambiguous assessment of the effects of accelerating factors (e.g., temperature and state of charge) on various measures of the health of a cell (e.g., power fade and capacity fade) will result. In order to assess cell lifetime, it is necessary to develop a model that accurately predicts degradation over a range of the experimental factors. In general, it is difficult to specify an appropriate model form without some preliminary analysis of the data. Nevertheless, assuming that the aging phenomenon relates to a chemical reaction with simple first-order rate kinetics, a data analysis protocol is also provided to construct a useful model that relates performance degradation to the levels of the accelerating factors. This model can then be used to make an accurate assessment of the average cell lifetime. The proposed experimental and data analysis protocols are illustrated with a case study involving the effects of accelerated aging on the power output from Gen-2 cells. For this case study, inadequacies of the simple first-order kinetics model were observed. However, a more complex model allowing for the effects of two concurrent mechanisms provided an accurate representation of the experimental data.

  16. Central muscarinic cholinergic activation alters interaction between splenic dendritic cell and CD4+CD25- T cells in experimental colitis.

    Directory of Open Access Journals (Sweden)

    Peris Munyaka

    Full Text Available BACKGROUND: The cholinergic anti-inflammatory pathway (CAP is based on vagus nerve (VN activity that regulates macrophage and dendritic cell responses in the spleen through alpha-7 nicotinic acetylcholine receptor (a7nAChR signaling. Inflammatory bowel disease (IBD patients present dysautonomia with decreased vagus nerve activity, dendritic cell and T cell over-activation. The aim of this study was to investigate whether central activation of the CAP alters the function of dendritic cells (DCs and sequential CD4+/CD25-T cell activation in the context of experimental colitis. METHODS: The dinitrobenzene sulfonic acid model of experimental colitis in C57BL/6 mice was used. Central, intracerebroventricular infusion of the M1 muscarinic acetylcholine receptor agonist McN-A-343 was used to activate CAP and vagus nerve and/or splenic nerve transection were performed. In addition, the role of α7nAChR signaling and the NF-kB pathway was studied. Serum amyloid protein (SAP-A, colonic tissue cytokines, IL-12p70 and IL-23 in isolated splenic DCs, and cytokines levels in DC-CD4+CD25-T cell co-culture were determined. RESULTS: McN-A-343 treatment reduced colonic inflammation associated with decreased pro-inflammatory Th1/Th17 colonic and splenic cytokine secretion. Splenic DCs cytokine release was modulated through α7nAChR and the NF-kB signaling pathways. Cholinergic activation resulted in decreased CD4+CD25-T cell priming. The anti-inflammatory efficacy of central cholinergic activation was abolished in mice with vagotomy or splenic neurectomy. CONCLUSIONS: Suppression of splenic immune cell activation and altered interaction between DCs and T cells are important aspects of the beneficial effect of brain activation of the CAP in experimental colitis. These findings may lead to improved therapeutic strategies in the treatment of IBD.

  17. Modelling and experimental evaluation of parallel connected lithium ion cells for an electric vehicle battery system

    Science.gov (United States)

    Bruen, Thomas; Marco, James

    2016-04-01

    Variations in cell properties are unavoidable and can be caused by manufacturing tolerances and usage conditions. As a result of this, cells connected in series may have different voltages and states of charge that limit the energy and power capability of the complete battery pack. Methods of removing this energy imbalance have been extensively reported within literature. However, there has been little discussion around the effect that such variation has when cells are connected electrically in parallel. This work aims to explore the impact of connecting cells, with varied properties, in parallel and the issues regarding energy imbalance and battery management that may arise. This has been achieved through analysing experimental data and a validated model. The main results from this study highlight that significant differences in current flow can occur between cells within a parallel stack that will affect how the cells age and the temperature distribution within the battery assembly.

  18. Experimental Study of Pollutant Transfer within Dwellings

    CERN Document Server

    Koffi, Juslin; Allard, Francis; Husaunndee, Ahmad

    2010-01-01

    A mechanical ventilation principle used in French residential buildings was tested in the experimental house of the CSTB research centre. The experiments dealt with pollutant removal efficiency of this ventilation principle, mainly with air tightness and the influence of internal doors. Tracer gas constant injection method was used to simulate the pollution source in the living room. SF6 concentrations were measured in several rooms. The results showed that the air flow routes were in agreement with the theory as long as internal doors were closed. When doors were open, the air pattern was disturbed a lot; a great quantity of the emitted pollutant was measured in the bedrooms. Besides, stack effect promotes the pollutant moving towards the bedrooms under higher indoor-outdoor air temperature differences. In addition, the results showed that if the opening of the bedroom window increases the air change rate, it does not guarantee a good indoor air quality.

  19. Experimental study of external fuel vaporization

    Science.gov (United States)

    Szetela, E. J.; Tevelde, J. A.

    1982-01-01

    The fuel properties used in the design of a flash vaporization system for aircraft gas turbine engines were evaluated in experiments using a flowing system to determine critical temperature and pressure, boiling points, dew points, heat transfer coefficients, deposit formation rates, and deposit removal. Three fuels were included in the experiments: Jet-A, an experimental referree broad specification fuel, and a premium No. 2 diesel fuel. Engine conditions representing a NASA Energy Efficient Engine at sea-level take-off, cruise, and idle were simulated in the vaporization system and it was found that single phase flow was maintained in the heat exchanger and downstream of the throttle. Deposits encountered in the heat exchanger represented a thermal resistance as high as 1300 sq M K/watt and a deposit formation rate over 1000 gC/sq cm hr.

  20. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    The experimental high energy physics program is directed toward the execution of experiments that probe the basic constituents of matter and the forces between them. These experiments are carried out at national and international accelerator facilities. At the current time, we are primarily concentrating on the following projects: Direct photon production in hadronic reactions; production of hybrid mesons in the nuclear Coulomb field; the D-Zero experiment at the Tevatron collider; deep inelastic neutrino- and electron-nucleon scattering at FNAL and SLAC; nonlinear QED at critical field strengths at SLAC; the experiments at KEK (AMY, 17keV neutrino); the CDF experiment at the Tevatron collider; and SSC-related detector R ampersand D on scintillating tile- and diamond-based calorimetry and microstrip tracking detectors

  1. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    The experimental high energy physics program is directed toward the execution of experiments that probe the basic constituents of matter and the forces between them. These experiments are carried out at national and international accelerator facilities. At the current time, we are primarily concentrating on the following projects: Direct photon production in hadronic reactions (Fermilab E706); Production of hybrid mesons in the nuclear Coulomb field; The D-Zero experiment at the Tevatron collider; Deep inelastic neutrino- and electron-nucleon scattering at FNAL and SLAC; Nonlinear QED at critical field strengths at SLAC; The Experiments at KEK (AMY, 17keV neutrino); The CDF experiment at the Tevatron collider; and SSC-related detector R ampersand D on scintillating tile- and diamond-based calorimetry and microstrip tracking detectors

  2. Experimental Study of the Sampled Labyrinth Chaos

    Directory of Open Access Journals (Sweden)

    J. Petrzela

    2011-12-01

    Full Text Available In this paper, some new numerical as well as experimental results connected with the so-called labyrinth chaos are presented. This very unusual chaotic motion can be generated by mathematical model involving the scalar goniometrical functions which makes a three-dimensional autonomous dynamical system strongly nonlinear. Final circuitry implementation with analog core and digital parts can be used for modeling Brownian motion. From the viewpoint of generating chaotic motion by some electronic circuit, first step is to solve problems associated with the two-port nonlinear transfer functions synthesis. In the case of labyrinth chaos the finite dynamical range of the input variables introduced by the used active elements usually limits the performance greatly, similarly as it holds for the multi-grid spiral attractors. This paper shows an elegant way how to remove these obstacles by using uni-versal multiple-port with internal digital signal processing.

  3. Computational and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, Mitchell [Yale Univ., New Haven, CT (United States)

    2015-05-29

    During the past three years, our research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in coflowing axisymmetric configurations. We have pursued both computational and experimental aspects of the research in parallel on both steady-state and time-dependent systems. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the steady-state and time-dependent boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. Previously, spontaneous Raman scattering, chemiluminescence, and laser-induced fluorescence were used to measure the temperature, major and minor species profiles. Particle image velocimetry (PIV) has been used to investigate velocity distributions and for calibration of time-varying flames. Laser-induced incandescence (LII) with an extinction calibration was used to determine soot volume fractions, while soot surface temperatures were measured with three-color optical pyrometry using a color digital camera. A blackbody calibration of the camera allows for determination of soot volume fraction as well, which can be compared with the LII measurements. More recently, we have concentrated on a detailed characterization of soot using a variety of techniques including time-resolved LII (TiRe-LII) for soot primary particles sizes, multi-angle light scattering (MALS) for soot radius of gyration, and spectrally-resolved line of sight attenuation (spec-LOSA). Combining the information from all of these soot measurements can be used to determine the soot optical properties, which are observed to vary significantly depending on spatial location and fuel dilution. Our goal has been to obtain a more fundamental understanding of the important fluid dynamic and chemical interactions in

  4. Structural analysis and experimental characterization of cylindrical lithium-ion battery cells subject to lateral impact

    Science.gov (United States)

    Avdeev, Ilya; Gilaki, Mehdi

    2014-12-01

    We report on modeling mechanical response of cylindrical lithium-ion battery cells that are commonly used in automotive applications when subjected to impact testing. The developed homogenized model that accurately captures mechanical response of a cell to lateral crash is reported. The proposed model was validated using static and dynamic experimental testing. Highly nonlinear mechanical deformations of the cells were captured experimentally using a high-speed camera and later characterized through computer tomography. Numerically, we have investigated the feasibility of using explicit finite element code for accurate modeling of impact on one cell, so it can be used for an entire battery pack that consists of hundreds or thousands of cells. In this study, we have developed and compared two homogenization methods for the jellyroll in a cylindrical lithium-ion battery cell. Homogenization was conducted in a lateral/radial direction. Based on the results of the homogenization, the material model utilizing crushable foam constitutive behavior was then developed for simulations. Experimental results showed a very good agreement with simulations, thus validating the proposed approach and giving us confidence to move forward with the crush simulations of an entire battery pack. Zones of potential electric shortages were determined based on the experiments and simulations.

  5. The complement inhibitor FUT-175 suppresses T cell autoreactivity in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Li, Qing; Nacion, Kristine; Bu, Hong; Lin, Feng

    2009-08-01

    Several recent studies have shown that interacting antigen presenting cells and/or T cells produced complement activation products C5a and C3a, are integrally involved in T-cell activation, and promote the generation of myelin oligodendrocyte glycoprotein (MOG(35-55))-specific interferon-gamma and interleukin-17-producing T cells in experimental autoimmune encephalomyelitis, a rodent model of multiple sclerosis. In this study, we tested whether FUT-175, a clinical pharmaceutical that has been shown to inhibit the formation of C3/C5 convertases, can attenuate myelin-specific T-cell responses, as well as disease severity in experimental autoimmune encephalomyelitis. In vitro, FUT-175 inhibited local C5a/C3a production by antigen presenting cell-T-cell complexes and attenuated MOG(35-55)-specific Th1 and Th17 responses with little nonspecific cytotoxicity. In vivo administration of FUT-175 delayed experimental autoimmune encephalomyelitis disease onset, lowered clinical scores, decreased central nervous system inflammation, and reduced demyelination. The FUT-175-treated mice exhibited decreased numbers of MOG(35-55)-specific interferon-gamma- and interleukin-17-producing T cells. In addition, results from the FUT-175 treatment of naive recipients of adoptively transferred splenocytes from MOG(35-55)-immunized mice suggested that the effect of FUT-175 was on MOG-specific cellular responses and not on anti-MOG antibodies. These results argue that complement regulators, which inhibit C5a/C3a production, may have therapeutic efficacy in multiple sclerosis and in other clinical conditions in which T cells drive disease pathogenesis. PMID:19608865

  6. Experimental studies of lower hybrid wave propagation

    International Nuclear Information System (INIS)

    Experimental measurements of the dispersion and damping of externally excited lower hybrid waves are presented. A multiple-ring slow-wave antenna, having 2π/k/sub z/ = 23 cm, is used to excite these waves in the Princeton L3 or L4 linear devices (B = 0.5 -- 2.8 kG uniform to +- 1 percent for 1.6 m, n approximately 1010, T/sub e/ approximately 3-5 eV, T/sub i/ less than or equal to 0.1 eV, He gas, plasma diameter approximately 10 cm). The waves are localized in a spatial wave packet that propagates into the plasma along a conical trajectory which makes a small angle with respect to the confining magnetic field. Measurements of the dependence of wavelength on frequency are in good agreement with the cold plasma dispersion relation. Measured values of the wave damping are in good agreement with Landau damping by the combination of the main body of the electron distribution and a approximately 30 percent high energy (T/sub e/ approximately 15-30 eV) electron tail

  7. Experimental studies of a drumlike silencer.

    Science.gov (United States)

    Choy, Y S; Huang, Lixi

    2002-11-01

    The theoretical finding of the broadband performance of a reactive silencer is validated experimentally. The silencer consists of two highly stretched membranes lining part of the duct and backed by two long and shallow cavities. The test rig was built with a small square duct of 5 cm in dimension, and each cavity is 5 cm deep and 25 cm long. Two types of metal foils, stainless steel and copper, were used, and the lowest membrane-to-air mass ratio was 1.3. A transmission loss in excess of 10 dB was achieved over more than one octave band. For one configuration close to the optimal parameters, the predicted ratio of the frequency band limits is 2.47, while the experiment gave 2.35. Three spectral peaks were found in the stopband, as predicted, but the peaks were broader than prediction, indicating the presence of significant sound energy dissipation mechanisms. Comparison with theoretical simulation shows that the cavity damping dominates over membrane friction. Tests using heavier membranes and membrane with different levels of tension also agree with predictions. Issues of practical implementation of the concept as a flow-through silencer are also addressed.

  8. Experimental study on HVAC sound parameters

    Science.gov (United States)

    Bujoreanu, C.; Benchea, M.

    2016-08-01

    HVAC system represent major source of buildings internal noise and therefore they are designed to provide a human acoustic comfort besides the thermal and air quality requirements. The paper experimentally investigates three types of commercial air handler units (AHU) with different ducts cross-section sizes and inlet-outlet configuration. The measurements are performed in an anechoic room. The measurements are carried out at different fan's speeds, ranging the power-charge from 30-100% while the duct air flow is slowly adjusted from full open to full closed, between 0-500 Pa. The sound pressure levels of the radiant units are rated using NR curves. Also, the supply and the outdoor ducts sound levels are compared in order to point the frequencies where the noise must be reduced. Third-octave band analysis of random noise of an air handling unit from a HVAC system is realized, using measurement procedures that agrees the requirements of the ISO 3744:2011 and ISO 5136:2010 standards. The comparatively results highlight the effects of the geometry, air flow pressure and power-charging dependencies upon the sound level. This is the start for a noise reduction strategy.

  9. Experimental studies of bone mechanoadaptation: bridging in vitro and in vivo studies with multiscale systems.

    Science.gov (United States)

    Brown, Genevieve N; Sattler, Rachel L; Guo, X Edward

    2016-02-01

    Despite advancements in technology and science over the last century, the mechanisms underlying Wolff's law-bone structure adaptation in response to physical stimuli-remain poorly understood, limiting the ability to effectively treat and prevent skeletal diseases. A challenge to overcome in the study of the underlying mechanisms of this principle is the multiscale nature of mechanoadaptation. While there exist in silico systems that are capable of studying across these scales, experimental studies are typically limited to interpretation at a single dimension or time point. For instance, studies of single-cell responses to defined physical stimuli offer only a limited prediction of the whole bone response, while overlapping pathways or compensatory mechanisms complicate the ability to isolate critical targets in a whole animal model. Thus, there exists a need to develop experimental systems capable of bridging traditional experimental approaches and informing existing multiscale theoretical models. The purpose of this article is to review the process of mechanoadaptation and inherent challenges in studying its underlying mechanisms, discuss the limitations of traditional experimental systems in capturing the many facets of this process and highlight three multiscale experimental systems which bridge traditional approaches and cover relatively understudied time and length scales in bone adaptation. PMID:26855756

  10. [Experimental study on chemotherapy of acute glanders].

    Science.gov (United States)

    Iliukhin, V I; Rotov, K A; Senina, T V; Snatenkov, E A; Tikhonov, S N; Plekhanova, N G; Kulikova, A S; Shubnikova, E V; Korol', E V; Nekhezina, M O

    2012-01-01

    Glanders is a zoonotic infection inducing acute forms of the disease (pneumonia, sepsis) in humans and animals under certain conditions, which even with the use of modern chemotherapy have unfavourable prognosis. Insufficient of efficacy of antibiotics with in vitro low MIC for planktonic bacterial suspension of Burkholderia mallei in chemotherapy of acute forms of glanders was due to the capacity of the pathogen for intracellular survival and formation of biofilms. Under such conditions the susceptibility of B. mallei to antibiotics lowered by several orders of magnitude. Chemotherapy of the glanders acute forms in animals usually provided only an increase of the lifespan, while among the survivors there was recorded a high relapse rate. More favourable outcomes were observed with the use of in vitro effective antibiotics in the form of clathrate compounds or especially liposomal forms. In the experiments with golden hamsters the survival rate reached 100% in 1000 Dlm infection even with the treatment onset by meropenem liposomal form 48 hours after the infection. Chemotherapeutics in the liposomal form significantly lowered resistance of B. mallei in both the experiments with a suspension of planktonic organisms and the use of bacteria interned in eukaryotic cells (Tetrahymena pyriformis).

  11. Molecular biology of breast cancer metastasis: Clinical implications of experimental studies on metastatic inefficiency

    International Nuclear Information System (INIS)

    Recent technological advances have led to an increasing ability to detect isolated tumour cells and groups of tumour cells in patients' blood, lymph nodes or bone marrow. However, the clinical significance of these cells is unclear. Should they be considered as evidence of metastasis, necessitating aggressive treatment, or are they in some cases unrelated to clinical outcome? Quantitative experimental studies on the basic biology of metastatic inefficiency are providing clues that may help in understanding the significance of these cells. This understanding will be of use in guiding clinical studies to assess the significance of isolated tumour cells and micrometastases in cancer patients

  12. Cell survival studies for moving targets

    International Nuclear Information System (INIS)

    More than 330 patients with static tumors have been treated at GSI with a scanned C-12 beam. For targets that are subject to respiratory motion, treatment is not yet possible because target motion and scanning motion interfere. GSI is developing a motion compensation system to compensate target motion by adaptation of each individual Bragg peak position. Within this project, the GSI treatment planning software TRiP was extended to calculate physical dose distributions in the presence of motion. These motion extensions were experimentally validated. Recently we included the calculation of cell survival for moving targets. To validate the software, a program of experimental studies with biological samples has been started. In a first set of experiments, living cell cultures were placed on a periodically moving table and irradiated with and without motion compensation. Results are compared to reference cell cultures that were static during standard irradiations. Furthermore, measured cell survival distributions are compared to calculated distributions for all irradiation schemes

  13. Growth hormone and retinal ganglion cell function: QNR/D cells as an experimental model.

    Science.gov (United States)

    Martínez-Moreno, Carlos; Andres, Alexis; Giterman, Daniel; Karpinski, Edward; Harvey, Steve

    2014-01-01

    Retinal ganglion cells (RGCs) have been shown to be sites of growth hormone (GH) production and GH action in the embryonic (embryo day 7, ED7) chick neural retina. Primary RGC cell cultures were previously used to determine autocrine or paracrine actions of GH in the retina, but the antibody used in their immunopanning (anti-Thy-1) is no longer available. We have therefore characterized an immortalized neural retina (QNR/D) cell line derived from ED7 embryonic quail as a replacement experimental model. These cells express the GH gene and have GH receptor (GHR)-immunoreactivity. They are also immunoreactive for RGC markers (islet-1, calretinin, RA4) and neural fibers (neurofilament, GAP 43, vimentin) and they express the genes for Thy-1, neurotrophin 3 (NTF3), neuritin 1 (NRN1) and brn3 (POU4F). These cells are also electrically active and therefore resemble the RGCs in the neural retina. They are also similarly responsive to exogenous GH, which induces overexpression of the neurotrophin 3 and insulin-like growth factor (IGF) 1 genes and stimulates cell survival, as in the chick embryo neural retina. QNR/D cells are therefore a useful experimental model to assess the actions of GH in retinal function. PMID:24239556

  14. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini

    2011-01-01

    Active magnetic regenerative (AMR) systems are being investigated because they represent a potentially attractive alternative to vapor compression technology. The performance of these systems is dependent on the heat transfer and pressure drop performance of the regenerator geometry. Therefore...... this article studies the effects of regenerator geometry on performance for flat plate regenerators. This paper investigates methods of improving the performance of flat plate regenerators for use in AMR systems and studies how manufacturing variation affects regenerator performance. In order to eliminate...

  15. Transdifferentiation of pancreatic α-cells into insulinsecreting cells: From experimental models to underlying mechanisms

    Institute of Scientific and Technical Information of China (English)

    Jieli; Lu; Rami; Jaafer; Rémy; Bonnavion; Philippe; Bertolino; Chang-Xian; Zhang

    2014-01-01

    Pancreatic insulin-secreting β-cells are essential regulators of glucose metabolism. New strategies are cur-rently being investigated to create insulin-producing β cells to replace deficient β cells, including the differentiation of either stem or progenitor cells, and the newly uncovered transdifferentiation of mature non-β islet cell types. However, in order to correctly drive any cell to adopt a new β-cell fate, a better understanding of the in vivo mechanisms involved in the plasticity and biology of islet cells is urgently required. Here, we review the recent studies reporting the phenomenon of transdifferentiation of α cells into β cells by focusing on the major candidates and contexts revealed to be involved in adult β-cell regeneration through this process. The possible underlying mechanisms of transdifferentiation and the interactions between several key factors involved in the process are also addressed. We propose that it is of importance to further study the molecular and cellular mechanisms underlying α- to β-cell transdifferentiation, in order to make β-cell regeneration from α cells a relevant and realizable strategy for developing cell-replacement therapy.

  16. Changes of G cells and D cells in the antral mucosa in rat experimental gastric ulcer

    Institute of Scientific and Technical Information of China (English)

    SUN Feng-peng; SONG Yu-gang; CHENG Wei; ZHAO Tong

    2002-01-01

    Objective: To investigate the association of changes in G and D cells in the antral mucosa with the production of gastrin and somatostatin during gastric ulcer and the healing process. Methods: Experimental gastric ulcer was induced with acetic acid in 42 Wistar rats and another 7 normal rats served as control.Changes in the production of gastrin and somatostatin in the plasma, gastric fluid and the antral tissues of the rats were measured by radio immunoassay, and the number and distribution of G and D cells were respectively determined by immunochemistry and Quantimet500 image analysis system. Results: In rats with gastric ulcer, the gastrin levels in the plasma, gastric fluid and the antral tissues increased while somatostatin levels were reduced, which were corrected in the healing process. Immunochemistry demonstrated the increase in the number of G cells in the antral tissues with decrease in D cell number, and the area covered by both cells shrank. The G cell to D cell number and area ratios were both decreased after the onset of the ulcer and returned to the normal when the healing process took place. Conclusion: Secretion of gastrin by G cells increases and that of somatostatin by D cells declines during gastric ulcer in rats, and imbalance of G and D cells may be restponsible for gastrointestinal dysfunction.

  17. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin

    2012-10-04

    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  18. Experimental and Theoretical Studies on Biologically Active Lanthanide (III) Complexes

    Science.gov (United States)

    Kostova, I.; Trendafilova, N.; Georgieva, I.; Rastogi, V. K.; Kiefer, W.

    2008-11-01

    The complexation ability and the binding mode of the ligand coumarin-3-carboxylic acid (HCCA) to La(III), Ce(III), Nd(III), Sm(III), Gd(III) and Dy(III) lanthanide ions (Ln(III)) are elucidated at experimental and theoretical level. The complexes were characterized using elemental analysis, DTA and TGA data as well as 1H NMR and 13C NMR spectra. FTIR and Raman spectroscopic techniques as well as DFT quantum chemical calculations were used for characterization of the binding mode and the structures of lanthanide(III) complexes of HCCA. The metal—ligand binding mode is predicted through molecular modeling and energy estimation of different Ln—CCA structures using B3LYP/6-31G(d) method combined with a large quasi-relativistic effective core potential for lanthanide ion. The energies obtained predict bidentate coordination of CCA- to Ln(III) ions through the carbonylic oxygen and the carboxylic oxygen. Detailed vibrational analysis of HCCA, CCA- and Ln(III) complexes based on both calculated and experimental frequencies confirms the suggested metal—ligand binding mode. The natural bonding analysis predicts strongly ionic character of the Ln(III)-CCA bonding in the- complexes studied. With the relatively resistant tumor cell line K-562 we obtained very interesting in-vitro results which are in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.

  19. Experimental study on dynamic gas adsorption

    Institute of Scientific and Technical Information of China (English)

    Qin Yueping; Wang Yaru; Yang Xiaobin; Liu Wei; Luo Wei

    2012-01-01

    In order to predict the actual adsorption amount as gas adsorption reaches the equilibrium,this research designed a dynamic gas adsorption experiment under constant temperature and pressure,and also studied the isopiestic adsorption characteristics of coal samples with same quality but different sizes.Through the experiment,the study found the adsorption-time changing relationships under different pressures of four different size samples.After regression analysis,we obtained the functional relationship between adsorption and time.According to this,the research resulted in the actual adsorption amount when gas adsorption reaches the equilibrium.In addition,the current study obtained the relationship between adsorption and pressure as well as the effect of the coal size to the adsorption rate.These results have great theoretical and practical significance for the prediction of gas amount in coal seam and gas adsorption process.

  20. Experimental studies of actinides in molten salts

    International Nuclear Information System (INIS)

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs

  1. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  2. Experimental Studies on Glass Fiber Concrete

    Directory of Open Access Journals (Sweden)

    J.D.Chaitanya kumar

    2016-06-01

    Full Text Available Concrete is one of the most widely recognized development material for the most part delivered by utilizing locally accessible ingredients. The development of concrete has brought about the essential need for additives both chemical and mineral to improve the performance of concrete. Hence varieties of admixtures such as fly ash, coconut fibre have been used so far. Hence an attempt has been made in the present investigation to study the behaviour of glass fibre in concrete. The present trend in concrete technology is towards increasing the strength and durability of concrete to meet the demands of the modern construction. The main aim of the study is to study the effect of glass fibre in the concrete. Glass fibre has the high tensile strength and fire resistant properties thus reducing the loss of damage during fire accidents. The addition of these fibres into concrete can dramatically increase the compressive strength, tensile strength and split tensile strength of the concrete. In this study, tests have done for the concrete with glass fibre of 0.5%, 1%, 2% and 3% of cement by adding as an admixture

  3. Experimental studies and CFD simulations of conical spouted bed hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.

    2008-07-01

    This thesis involved both experimental research and mathematical modelling of the hydrodynamics of conical spouted beds. Although conical spouted beds are commonly used for drying suspensions, solutions and pasty materials, they can also be used for catalytic partial oxidation of methane to synthesis gas, coal gasification and liquefaction, and pyrolysis of sawdust. Pressure transducers and static pressure probes were used in the experimental studies to investigate the evolution of the internal spout and the local static pressure distribution. Optical fibre probes were used to measure axial particle velocity profiles and voidage profiles. The gas mixing behaviour inside a conical spouted bed was examined using a step trace injection technique in which helium was used as the tracer and thermal conductivity cells were used as the detectors. For the mathematical modelling, a stream-tube model based on the bed structure inside a conical spouted bed was proposed to simulate partial spouting states. An adjustable parameter was introduced into the model to enable total pressure drop prediction under different operating conditions, and to estimate axial superficial gas velocity profiles and gauge pressure profiles. A mathematical model based on characteristics of conical spouted beds and FLUENT software was also developed and validated using measured experimental data. The proposed CFD model can simulate both stable spouting and partial spouting states, with an adjustable solids-phase source term. The effect of all possible factors on simulation results were investigated, including the fluid inlet profile, solid bulk viscosity, frictional viscosity, restitution coefficient, exchange coefficient, and solid phase source term. In addition to simulating the gas mixing behaviours inside a conical spouted bed, the new CFD model simulated cylindrical packed beds and cylindrical fluidized beds in one code package.

  4. Antigen-presenting cells transfected with Hsp65 messenger RNA fail to treat experimental tuberculosis

    International Nuclear Information System (INIS)

    In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis

  5. Antigen-presenting cells transfected with Hsp65 messenger RNA fail to treat experimental tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, C.D.; Trombone, A.P.F.; Lorenzi, J.C.C.; Almeida, L.P.; Gembre, A.F.; Padilha, E. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Ramos, S.G. [Departamento de Patologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Silva, C.L.; Coelho-Castelo, A.A.M. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-09-21

    In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis.

  6. [Histoautoradiographic study of the heart in experimental myocardial ischemia].

    Science.gov (United States)

    Makhova, A N; Shliapnikov, V N

    1979-01-01

    Autoradiographic examinations of the heart muscle in experimental myocardial necroses using 3H-thymidine, revealed a high DNA synthesis in the connective tissue cells in the zone of necrosis in the acute period of infarction and its subsequent decrease. Deviations from this regularity were observed when relapses of necrosis developed. The activation of DNA synthesis occurred to a lesser extent in stromal cells of the periinfarction and remote zones of the heart. Muscle cells incorporated 3H-thymidine extremely rarely. When myocardial infarction was combined with aterosclerosis, relapses of necrosis occurred frequently, and morphological changes in many arteries and veins were accompanied by 3H-thymidine incorporation into the nuclei of the endothelium, smooth cells and adventitial cells. Inhibition of DNA synthesis in connective tissue cells of various heart zones was observed in cases of combined myocardial infarction and aterosclerosis and hypertension.

  7. Experimental study on a simplified crossflow turbine

    Directory of Open Access Journals (Sweden)

    Chiyembekezo S. Kaunda, Cuthbert Z. Kimambo, Torbjorn K. Nielsen

    2014-01-01

    Full Text Available The main aim of the study is to enhance the design of a Crossflow turbine, as an appropriate technology for small-scale power generation. This study evaluates the performance of a simplified Crossflow turbine at conditions other than the ‘best efficiency point’. It also explores the ‘reaction’ behavior of the Crossflow turbine as well as characterizes the torque transfer in the two stages of the turbine. The experiments were conducted on a physical simplified Crossflow turbine model using the test facilities in the Waterpower Laboratory at the Norwegian University of Science and Technology. The results show that the maximum turbine efficiency is 79%, achieved at a head of 5m and reduced speed of 13.4; making it a low speed turbine. This turbine efficiency compares well with some reported efficiency values. The result also show that the turbine is efficient when it operates with a degree of reaction and this is achieved at large valve openings; validating observations that the Crossflow turbine is not a pure impulse turbine. Performance evaluation outside the best efficiency point shows that the efficiency decreases with increase in head above the best efficiency head. The turbine efficiency is not sensitive to flow variations: except at a head of 3m, at all tested heads, 25% of the flow at best efficiency point still generates efficiency of above 50%. Torque characterization shows that the second stage plays a significant role in torque transfer, especially when at large valve openings. Therefore, design efforts must also look at how the flow inside the runner interior space can be controlled so that the jet enters the second stage with optimum flow angles. The use of strain gauge to characterize the torque produced using momentum principle as employed in this study presents an additional opportunity to analyze the trends in the torque transfer.

  8. Experimental study of relative, turbulent diffusion

    DEFF Research Database (Denmark)

    Mann, J.; Ott, Søren; Andersen, J.S.

    1999-01-01

    The purpose is to study relative turbulent diffusion under controlled, reproducible conditions in the laboratory in order to estimate the constant C in Richardson-Obukhov's law. We get C #approx# 0.4 -- 0.6. We furthermore measure the distance-neighbourfunction, which is the probability density...... system with two computers each equipped with a frame grabber card. In the search for the best experimentalmethods we have revised the concept of local homogeneity and derived a law for the velocity--acceleration structure function. A second by-product of this effort is a relatively simple derivation...

  9. The experimental study of effect of exosomes derived from breast cancer cell line on human umbilical vein endothelial cells%乳腺癌细胞exosomes对人脐静脉内皮作用的实验研究

    Institute of Scientific and Technical Information of China (English)

    谢莹珊; 沈宜; 隆霜; 孙迪; 姜蓉; 陈黎

    2011-01-01

    Objective:To observe the effect of exosomes derived from MDA- MB- 231 cell line on proliferation, immigration and capillary- like tube formation of Human Umbilical Vein Endothelial cells. Method: Exosomes were puried by serial ultracentrifugation and sugar density ultracentrifugation, MTT assay was used to observe the effect of exosomes on proliferation of HUVECs;HUVECs were treated with exosomes for 24 h,the change of cell migration was detected by Transwell chamber method. The capillary-like tube formations by HUVECs were observed. Result: MTT result showed that the concentration range of exosomes significantly increased HUVECs proliferation in a concentration - and time - dependent manner ( P < 0.01 ); It may significantly enhance the migration of HUVECs after treated with 200 μ/ml exosomes for 24 h ( P < 0.01 ) , and may significantly promoted the capability of capillary - like tube formation of HUVECs ( P < 0.05 ) Conclusion: Exosomes derived from MDA - MB - 231 cell line significantly increased HUVECs proliferation in a concentration - and time - dependent manner and it may promote the migration and the capability of capillary - like tube formation of HUVECs.%目的:观察人乳腺癌细胞株MDA-MB-231细胞源exosomes对人脐静脉内皮细胞株(HUVECs)增殖、迁移能力及血管样结构形成的影响.方法:超速离心及密度梯度离心法提取exosomes;MTT法检测MDA-MB-231细胞源exosomes对HUVECs增殖的影响;Transwell小室法检测HUVECs与exosomes混合培养24h后迁移能力的影响;观察HUVECs与exosomes混合培养24h后管腔样结构形成变化.结果:各浓度exosomes均具有促进HUVECs细胞增殖作用,且以时间剂量依赖性促进HUVEC细胞增殖(P

  10. Experimental Study of Fractal Image Compression Algorithm

    Directory of Open Access Journals (Sweden)

    Chetan R. Dudhagara

    2012-08-01

    Full Text Available Image compression applications have been increasing in recent years. Fractal compression is a lossy compression method for digital images, based on fractals. The method is best suited for textures and natural images, relying on the fact that parts of an image often resemble other parts of the same image. In this paper, a study on fractal-based image compression and fixed-size partitioning will be made, analyzed for performance and compared with a standard frequency domain based image compression standard, JPEG. Sample images will be used to perform compression and decompression. Performance metrics such as compression ratio, compression time and decompression time will be measured in JPEG cases. Also the phenomenon of resolution/scale independence will be studied and described with examples. Fractal algorithms convert these parts into mathematical data called "fractal codes" which are used to recreate the encoded image. Fractal encoding is a mathematical process used to encode bitmaps containing a real-world image as a set of mathematical data that describes the fractal properties of the image. Fractal encoding relies on the fact that all natural, and most artificial, objects contain redundant information in the form of similar, repeating patterns called fractals.

  11. Acrolein and embryogenesis: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Chhibber, G.; Cilani, S.H.

    1986-01-01

    The effects of acrolein were studied on the chick embryos of 48 and 72 hr of incubation. Acrolein was dissolved in physiological saline and injected into the air sacs of the eggs at doses ranging from 0.001 to 0.1 mg per egg. The controls received and equal amount of saline only (0.1 ml per egg). All the embryos including controls were examined at Day 13. In all, 600 eggs were utilized for this investigation. At 48 hr incubation, the percentage survival ranged from 80 to 0 as the dosage of acrolein was increased. Embryonic mortality following 72 hr incubation did not increase significantly at any dose level. Gross malformations such as short and twisted limbs, everted viscera, microphthalmia, short and twisted neck, and hemorrhage over the body were observed. The frequency and the types of gross abnormalities did not vary much in the 48- or 72-hr-treated groups. The incidence of malformation in the controls was low. The results of this study indicates that acrolein is embryotoxic at higher doses and moderately teratogenic to chick embryogenesis.

  12. Tomato Lycopene and Lung Cancer Prevention: From Experimental to Human Studies

    OpenAIRE

    Assunta Catalano; Rossella E. Simone; Paola Palozza; Maria Cristina Mele

    2011-01-01

    Increasing evidence suggests that tomato lycopene may be preventive against the formation and the development of lung cancer. Experimental studies demonstrated that lycopene may inhibit the growth of several cultured lung cancer cells and prevent lung tumorigenesis in animal models through various mechanisms, including a modulation of redox status, cell cycle arrest and/or apoptosis induction, a regulation of growth factor signaling, changes in cell growth-related enzymes, an enhancement of g...

  13. Experimental Studies of Dynamics at Solid Surfaces

    Science.gov (United States)

    Germer, Thomas Avery

    1992-01-01

    Measurements of thermal and photoinduced processes on metal surfaces point to the importance of transient intermediate species in the understanding of dynamics. Experiments were performed using photoinduced desorption (PID), thermal desorption spectroscopy (TDS), high-resolution and time -resolved electron-energy-loss spectroscopy (HREELS and TREELS), and femtosecond multiphoton photoemission spectroscopy. The thermal and photoinduced reactions of Mo(CO)_6 adsorbed on Rh(100) were studied to better understand energy transfer between a photoexcited molecule and a metal surface. The Mo(CO)_6 partially dissociated upon adsorption, allowing a comparison to be made between Mo(CO)_6 adsorbed on the fragment-covered surface and a more ordered CO-covered surface. The energy transfer rate was found to be larger on the fragment-covered surface. The thermal reaction of hydrogen gas with oxygen adsorbed on Pt(111) was studied with TREELS between 130 and 160 K, observing the modes associated with hydroxyl adsorbed on the surface as a function of time while the sample, preadsorbed with atomic oxygen, was exposed to hydrogen gas. In coordination between Monte Carlo calculations and kinetic simulations, a model was developed whereby the reaction to form hydroxyl occurred between a molecular hydrogen precursor and oxygen at island boundaries. The photoinduced reaction of adsorbed atomic hydrogen and molecular oxygen to form hydroxyl and water on Pt(111) was studied in order to understand the reactivity of the hot oxygen atoms produced by photodissociation of molecular oxygen. The final products of the two oxygen -hydrogen reactions were the same. A measurement was made of the cross section for NO photodesorption from Pt(111) at 90 K. All of these experiments pointed to a need to make transient measurements on the ultrashort time scale in order to develop a more microscopic understanding of the dynamical processes that are occurring. As a result, a novel time-of-flight analyzer was

  14. Experimental study on the adiabatic shear bands

    International Nuclear Information System (INIS)

    Four martensitic steels (Z50CDV5 steel, 28CND8 steel, 35NCDV16 steel and 4340 steel) with different hardness between 190 and 600 Hsub(B) (Brinell hardness), have been studied by means of dynamic compressive tests on split Hopkinson pressure bar. Microscopic observations show that the fracture are associated to the development of adiabatic shear bands (except 4340 steel with 190 Hsub(B) hardness). By means of tests for which the deformation is stopped at predetermined levels, the measurement of shear and hardness inside the band and the matrix indicates the chronology of this phenomenon: first the localization of shear, followed by the formation of adiabatic shear band and ultimatly crack initiation and propagation. These results correlated with few simulations by finite elements have permitted to suggest two mecanisms of deformation leading to the formation of adiabatic shear bands in this specific test

  15. Experimental study of diffuse auroral precipitations

    International Nuclear Information System (INIS)

    First chapter is devoted to low energy electron precipitation in the evening sector of the auroral magnetosphere, during quiet and disturbed magnetic periods. Four subjects are studied in detail: the latitude distribution of the varied auroral forms and their relations to external magnetosphere; the time coefficients related to precipitations, the form and the dynamic of the diffuse precipitation equatorial frontier; the precipitation effect on the ionosphere concentration. The last part of the chapter shows that the plasma convection in the magnetosphere, associated to wave-particle interactions near the equatorial accounts for the principal characteristics of the evening sector diffuse electronic precipitations. The second chapter deals with subauroral precipitations of low energy ions, after the magnetospheric substorms, in the high latitude regions of the morning sector

  16. Patterns of power communication: an experimental study

    Directory of Open Access Journals (Sweden)

    Kali Prasad

    1958-07-01

    Full Text Available "Communication in one form or others is the basis of all social interaction. This paper deals with a particular aspect of communication namely, the effect of power and authority on the communication patterns that are set up between individuals. In such situation usually a power differential exists between the individuals as in the case of an employer and an employee, and this is responsible for setting up different attitudes in the mind of the people. The aim of the experiment described here is to study the reactions in individuals to expression of praise and hostility. The main finding is that those who are in power e.g. the employers are not so susceptible to praise as those who are subordinate to them. Also, a superior power person is less disturbed by hostile act of a subordinate than vice versa.

  17. Experimental study on phase perception in speech

    Institute of Scientific and Technical Information of China (English)

    BU Fanliang; CHEN Yanpu

    2003-01-01

    As the human ear is dull to the phase in speech, little attention has been paid tophase information in speech coding. In fact, the speech perceptual quality may be degeneratedif the phase distortion is very large. The perceptual effect of the STFT (Short time Fouriertransform) phase spectrum is studied by auditory subjective hearing tests. Three main con-clusions are (1) If the phase information is neglected completely, the subjective quality of thereconstructed speech may be very poor; (2) Whether the neglected phase is in low frequencyband or high frequency band, the difference from the original speech can be perceived by ear;(3) It is very difficult for the human ear to perceive the difference of speech quality betweenoriginal speech and reconstructed speech while the phase quantization step size is shorter thanπ/7.

  18. Experimental Studies of Top Quark Production

    CERN Document Server

    Wagner-Kuhr, Jeannine

    2016-01-01

    In this review article three promising aspects of top quark production are discussed: the charge asymmetry in top quark pair production, the search for resonant top quark pair production, and electroweak single top quark production. First, an overview of the theoretical predictions of top quark pair and single top quark production is given. Then, for each topic the general analysis strategy and improvements are exemplarily explained using selected analyses and are put into the context of the global status at the beginning of LHC Run II and progress in this field. The example analyses discussed in more detail in this article use data from the LHC experiment CMS and for the charge asymmetry studies also data from the Tevatron experiment CDF have been used.

  19. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge

    2011-10-01

    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  20. Experimental and clinical studies with intraoperative radiotherapy

    International Nuclear Information System (INIS)

    Studies of normal tissue tolerance to intraoperative radiotherapy were done upon 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from zero to 5,000 rads. Results of studies indicated that intact aorta and vena cava tolerate up to 5,000 rads without loss of structural integrity. Ureteral fibrosis and stenosis develop at doses of 3,000 rads or more. Arterial anastomoses heal after doses of 4,500 rads, but fibrosis can lead to occlusion. Intestinal suture lines heal after doses of 4,500 rads. Bile duct fibrosis and stenosis develop at doses of 2,000 rads or more. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed upon 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional postoperative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in four of 20 patients. Postoperative complications occurred in four of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 months. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved

  1. A Simplified Experimental Scheme for the Study of Mitosis.

    Science.gov (United States)

    Gill, John

    1980-01-01

    A procedure is described for providing preparations of dividing cells from root apical meristems, requiring only inexpensive equipment and minimal experimental skill, and using 8-Hydroxyquinoline and Toluidene-blue as a chromosome stain. The method has been sucessfully tested in schools and yields permanent preparations of adequate quality for…

  2. Experimental Study on Hydrocarbon Fuel Thermal Stability

    Institute of Scientific and Technical Information of China (English)

    J.S.Chin; A.H.Lefebvre

    1992-01-01

    The-thermal stability characteristics of kerosine-type fuels are examined using a heated-tube apparatus which allows independent control of fuel pressure,fuel temperature,tube-wall temperature and fuel flow rate.This method is identified simply as a "constant wall temperature method”,It is different from a previous widely used method ,which is identified as a “Constant heat flux method”,It is a single-pass system.Rate of deposition on the tube walls are measured by weighing the test tube before and after each test.For a fuel temperature of 250℃,it is found that deposition rates increease continuously with increase in tubewall temperature.This finding contradicts the results of previous studies which had led to the conclusion that deposition rates increase with increase in wall temperature up to a certain value(around 650K) beyond which any further increase in wall temperature causes the rate of deposition to decline.The present results show clearly that the constant wall temperature method is more suitable for assessing the thermal stability of gas turbine fuels.

  3. Experimental study of high beta toroidal plasmas

    International Nuclear Information System (INIS)

    Experiments on the Wisconsin Levitated Toroidal Octupole have produced a wide range of stable high β plasmas with β significantly above single fluid MHD theory predictions. A stable β approx. 8% plasma, twice the fluid limit, is obtained with 5 rho/sub i/ approx. L/sub n/ and tau/sub β/ approx. = 6000 tau/sub Alfven/ = 600 μsec. The enhanced stability is explained with a kinetic treatment that includes the effect of finite ion gyroradius which couples the ballooning mode to an ion drift wave. In a more collisional, large gyroradius (2 rho/sub i/ approx. L/sub n/) regime, a stable β approx. 35% plasma is obtained with a decay time of 1000 Alfven times. Measurement of the equilibrium magnetic field in this regime indicates that the diamagnetic current density is five times smaller than predicted by ideal MHD, probably due to ion gyroviscosity. Particle transport is anomalous and ranges from agreement with the classical diffusion rate at the highest beta, lowest field plasma (B/sub P/ = 200 G), to thirteen times the classical rate in a β=11%, high field plasma (B/sub P/ = 860 G) where the level of enhancement increase with magnetic field. Fluctuations in density, electrostatic potential, and magnetic field have been studied in plasmas with β from 0.1% to 40%

  4. Experimental Studies of Electrothermal Plasma Gun

    International Nuclear Information System (INIS)

    The aim of the present work is to study the capillary plasma discharge dynamics and characteristics. The capillary plasma device is a new technology for producing high density plasma after ablating the capillary wall using a pulsed electric power. An Electrothermal Plasma Gun (ETG) is composed of a capillary discharge tube made of Teflon operated with simple RLC circuit. The device called Electrothermal Gun (ETG) which is composed of 4 capacitors (70 μF, 10 kV, 1.28 μH) connected in parallel to a plasma source by means of one high power supply. The gun was operated in open air at discharge energies between 35 J - 3.5 kJ according to charging voltage. The work presented in this thesis covers the following items, 1- Measurements of the basic parameters and characterizations of the pretest results of the electrical circuits and capillary plasma discharge using Rogowski coil, voltage probe and Photomultiplier. 2- Material processing including (physics of the surface modifications, the morphology of the surface by using Scanning Electron Microscope (SEM) at different conditions, compositions of the materials by using X-ray Fluorescence (XRF), Micro hardness test and material particle deposition.

  5. Experimental thermochemical study of two chlorodinitroaniline isomers

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro da Silva, Manuel A.V., E-mail: risilva@fc.up.p [Centro de Investigacao em Quimica, Department of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687 P-4169-007 (Portugal); Ribeiro da Silva, Maria D.M.C.; Santos, Ana Filipa L.O.M.; Ferreira, Ana I.M.C. Lobo; Galvao, Tiago L.P. [Centro de Investigacao em Quimica, Department of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687 P-4169-007 (Portugal)

    2010-04-15

    The standard (p{sup 0}=0.1MPa) molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, were derived from the combination of the values of the standard molar enthalpies of formation, in the crystalline phase, and of the standard molar enthalpies of sublimation, at the same temperature. The standard molar enthalpies of formation, in the crystalline phase, were derived from the standard massic energies of combustion, in oxygen, measured by rotating-bomb combustion calorimetry. The standard molar enthalpies of sublimation were calculated, by the application of the Clausius-Clapeyron equation, to the vapour pressures at several temperatures, measured by Knudsen effusion technique. The values of the standard molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, are discussed in terms of enthalpic increments, and the enthalpy of isomerization between the two compounds is compared with the same parameter for two isomers of chloronitroaniline, studied in previous works.

  6. EXPERIMENTAL STUDY OF MINIMUM IGNITION TEMPERATURE

    Directory of Open Access Journals (Sweden)

    Igor WACHTER

    2015-12-01

    Full Text Available The aim of this scientific paper is an analysis of the minimum ignition temperature of dust layer and the minimum ignition temperatures of dust clouds. It could be used to identify the threats in industrial production and civil engineering, on which a layer of combustible dust could occure. Research was performed on spent coffee grounds. Tests were performed according to EN 50281-2-1:2002 Methods for determining the minimum ignition temperatures of dust (Method A. Objective of method A is to determine the minimum temperature at which ignition or decomposition of dust occurs during thermal straining on a hot plate at a constant temperature. The highest minimum smouldering and carbonating temperature of spent coffee grounds for 5 mm high layer was determined at the interval from 280 °C to 310 °C during 600 seconds. Method B is used to determine the minimum ignition temperature of a dust cloud. Minimum ignition temperature of studied dust was determined to 470 °C (air pressure – 50 kPa, sample weight 0.3 g.

  7. An experimental study of radiation pneumonitis

    International Nuclear Information System (INIS)

    The study was undertaken to evaluate the radiological and microscopic findings of radiation penumonitis. All 50 rats, which were used for the experiment, received a single dose of 2,000 rads of radiation on right lung using 60Co teletherapy. Chest teleroentgenograms were checked weekly for 13 weeks and microscopic examinations of irradiated lung were performed monthly after irradiation. The results obtained are summarized as follows. 1. In roentgenologic examination, radiation pneumonitis began to appear 4 weeks after irradiation and progressed with time intervals and began to resolve after 11 weeks. 2. Chest roentgenologic findings were pneumonic consolidation, atelectasis, and pleural effusion of irradiated right lung with compensatory hyper-inflation of left lung. 3. In the microscopic examination, pneumonitis appeared 2 weeks after irradiation and progressed with time intervals and began to resolve after 8 weeks. 4. The microscopic findings were fibrin deposit in alveoli and increased cellularity, vascular thickening, edema and congestion. After septal fibrosis and hyperplasia of bronchial mucosa, suggesting early regenerative change of radiation fibrosis, were noted 12 weeks after irradiation

  8. Markets and morals: an experimental survey study.

    Science.gov (United States)

    Elias, Julio J; Lacetera, Nicola; Macis, Mario

    2015-01-01

    Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A) Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B) Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent) religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We relate these

  9. Markets and Morals: An Experimental Survey Study

    Science.gov (United States)

    Elias, Julio J.; Lacetera, Nicola; Macis, Mario

    2015-01-01

    Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another “repugnant” transaction, indoor prostitution, to address two questions: (A) Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B) Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the “commercialization” of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent) religiosity of the respondent—in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We relate

  10. Markets and morals: an experimental survey study.

    Directory of Open Access Journals (Sweden)

    Julio J Elias

    Full Text Available Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We

  11. Uremic pruritus. Clinical and experimental studies.

    Science.gov (United States)

    Ståhle-Bäckdahl, M

    1989-01-01

    The aim of the study was to investigate clinical aspects of pruritus in maintenance hemodialysis patients and to evaluate factors of putative pathogenic importance. 60-65% of the patients in a maintenance hemodialysis program during a two-year period suffered from itching. Patients with pruritus tended to have been on dialysis treatment longer than those without pruritus (p = 0.05), otherwise there was no difference in clinical data or routine laboratory tests. Measurement of itch intensity continuously over one week in 28 patients using a computerized method showed that itching peaked at night after two days without dialysis, was relatively high during treatment and lowest during the day following dialysis. Our results suggest that the accumulation of pruritogens between dialysis sessions influences the intensity of itching. Most patients had "dry" skin. Recording of the stratum corneum water content by measurement of electrical capacitance, in 31 patients (19 with pruritus) and 12 controls, disclosed no significant difference between dialysis patients and controls, but a tendency that pruritic patients had a lower water content than the other subjects. In different body areas, there was a positive correlation in all groups between the clinical estimation of xerosis and hydration. Serum concentrations of parathyroid hormone (PTH) were significantly higher in dialysis patients with pruritus than in those without, but there was no correlation between the degree of symptoms and the PTH level. Indirect immunohistochemistry revealed no immunoreactivity for different parts of the PTH molecule in skin biopsies from uremic patients. Intradermal injections of PTH fragments did not evoke itching or other cutaneous reactions in patients or controls. Our results do not support PTH as a peripheral mediator of uremic itching. Flare reactions induced by intradermal histamine injections were significantly smaller in 26 dialysis patients (18 with pruritus) than in 9 healthy

  12. Experimental study on ice-temperature storage and permeability characteristics of kidney epidermis cells%冰温保存肾表皮细胞及其渗透特性的实验研究

    Institute of Scientific and Technical Information of China (English)

    梁飞; 诸凯; 王雅博

    2014-01-01

    In this study,experiments were performed to determine the permeability characteristics of kidney epidermis cells at various temperatures and different osmotic pressures using microscopy image analysis,including osmotically inactive volume,membrane permeability of water,and membrane permeability of CPA. The mean volume at isotonic solution was Viso=2472.58μm3;the history of cell volume change conformed to Boyle van’t Hoff relationship. The experimental data then were fitted to a straight line by the linear least square method and extrapolated by linear regression to determine osmotically inactive volume Vb=0.22Viso. Permeability response to hypertonic CPA solution was observed. Membrane permeability of water (Lp) and membrane permeability of CPA (Ps) and its activation energy(Ea) in dimethyl sulfoxide (DMSO),ethylene glycol(EG) and glycerinum (GLY) solution were determined by using two-parameter transport model;Based on the survival rate data generated in ice-temperature and normal temperature storage,the optimal preservation temperature for kidney epidermis cells was obtained. Ice-temperature storage has bright application prospect in cryo-preservation.%以肾表皮细胞为研究对象,利用显微镜图像分析方法,研究了其在不同温度、不同渗透压下的渗透特性,其中包括细胞的非渗透体积、细胞膜对水和低温保护剂的渗透系数等。结果表明,在等渗溶液中,细胞的平均等渗体积Viso=2472.58μm3;细胞体积随溶液渗透压的变化规律符合Boyle van’t Hoff 关系式,利用最小二乘法对实验数据进行线性拟合处理,得到非渗透体积 Vb=0.22Viso;观察细胞在高渗低温保护剂溶液中的渗透响应,利用两参数模型,得到了不同温度下在二甲基亚砜、乙二醇、甘油溶液中肾表皮细胞对水的渗透系数(Lp)、对低温保护剂的渗透系数(Ps)及活化能(Ea);通过对细胞在冰温和常温下进行保存,测量

  13. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  14. Experimental Limitations Using Reprogrammed Cells for Hematopoietic Differentiation

    Directory of Open Access Journals (Sweden)

    Katharina Seiler

    2011-01-01

    Full Text Available We review here our experiences with the in vitro reprogramming of somatic cells to induced pluripotent stem cells (iPSC and subsequent in vitro development of hematopoietic cells from these iPSC and from embryonic stem cells (ESC. While, in principle, the in vitro reprogramming and subsequent differentiation can generate hematopoietic cell from any somatic cells, it is evident that many of the steps in this process need to be significantly improved before it can be applied to human cells and used in clinical settings of hematopoietic stem cell (HSC transplantations.

  15. Ageing choroid plexus and experimental models: morphometrical study

    International Nuclear Information System (INIS)

    Morphometric parameters of the light and dark rat choroid plexus epithelial cells were studied during development, after hypokinesia and low doses of ionizing radiation. Morphometric investigations were performed on semi-thin sections by using a point-counting (625 test points) method, performed with combined greed in the ocular of the light microscope for linear and planimetric estimations. Morphometric investigations in the present study and literature data provide further evidence that light and dark choroid plexus epithelial cells finish their differentiation on 30 days postnatum. The cell area of the dark epithelial cells is smaller than the cell area of the light cells and its difference retains up to 22 months. The relative part of the dark cells increases during ontogenesis and at 13 months it is larger than the relative part of the light cells. Morphometric changes of the epithelial cells during development suggest that dark and light cells are modulations of the same basic cells with possible functional differentiation starting from 17 days postconception and continue to 22 months. Morphometric changes of the light and dark epithelial cells during hypokinesia and low doses of ionizing radiation are different for light and dark cells and they depend on the kind of influence. They may be related with differences in the functional activity of the light and dark epithelial cells, specific for the applied extremum influence. (author)

  16. An experimental electronic model for a neuronal cell

    International Nuclear Information System (INIS)

    Over the last two decades, the study of information transmission in living beings has acquired great relevance, because it regulates and conducts the functioning of all of the organs in the body. In information transmission pathways, the neuron plays an important role in that it receives, transmits, and processes electrical signals from different parts of the human body; these signals are transmitted as electrical impulses called action potentials, and they transmit information from one neuron to another. In this work, and with the aim of developing experiments for teaching biological processes, we implemented an electronic circuit of the neuron cell device and its mathematical model based on piecewise linear functions. (paper)

  17. Experimental determination of optimal clamping torque for AB-PEM Fuel cell

    Directory of Open Access Journals (Sweden)

    Noor Ul Hassan

    2016-04-01

    Full Text Available Polymer electrolyte Membrane (PEM fuel cell is an electrochemical device producing electricity by the reaction of hydrogen and oxygen without combustion. PEM fuel cell stack is provided with an appropriate clamping torque to prevent leakage of reactant gases and to minimize the contact resistance between gas diffusion media (GDL and bipolar plates. GDL porous structure and gas permeability is directly affected by the compaction pressure which, consequently, drastically change the fuel cell performance. Various efforts were made to determine the optimal compaction pressure and pressure distributions through simulations and experimentation. Lower compaction pressure results in increase of contact resistance and also chances of leakage. On the other hand, higher compaction pressure decreases the contact resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers, consequently, lowering cell performance. The optimal cell performance is related to the gasket thickness and compression pressure on GDL. Every stack has a unique assembly pressure due to differences in fuel cell components material and stack design. Therefore, there is still need to determine the optimal torque value for getting the optimal cell performance. This study has been carried out in continuation of deve­lopment of Air breathing PEM fuel cell for small Unmanned Aerial Vehicle (UAV application. Compaction pressure at minimum contact resistance was determined and clamping torque value was calcu­la­ted accordingly. Single cell performance tests were performed at five different clamping torque values i.e 0.5, 1.0, 1.5, 2.0 and 2.5 N m, for achieving optimal cell per­formance. Clamping pressure distribution tests were also performed at these torque values to verify uniform pressure distribution at optimal torque value. Experimental and theoretical results were compared for making inferences about optimal cell perfor­man­ce. A

  18. 肾纤维囊为载体培养角膜内皮细胞的实验研究%Experimental studies on kidney fiber capsule as Carriers for Cultivating Corneal endothelial cells

    Institute of Scientific and Technical Information of China (English)

    唐光霞; 陈建苏; 徐锦堂

    2011-01-01

    Objective To investigate the feasibility of kidney fiber capsule as carriers for cultivating corneal endothelial cells and study the characteristics of the cultured cells. Methods Amplified corneal endothelial cells were seeded on culture plates or kidney fiber capsule,and cultured in vitro. Growths of endothelial cells on culture plates and kidney fiber capsule were identified with inverted microscope, immuno-fluorescence, HE staining and scanning electron microscopy. Results The results indicated that corneal endothelial cells attached firmly on the surface of kidney fiber capsule , and grew quickly. Endothelial cells showed polygon or hexagon morphology. Cells could keep the instinct morphology and function after several passage, and cells could be cultured for a long time. Growth and proliferation of cells on culture plate were poor. Conclusion Corneal endothelial cells on kidney fiber capsule grow well and with obvious cell morphology. This study provides a simple and efficient way for the cells cultured in vitro.%目的 探索以脱细胞的肾纤维囊作为载体培养角膜内皮细胞并研究角膜内皮细胞特性.方法 将培养扩增的角膜内皮细胞分别接种到培养板和肾纤维囊上进行体外培养,采用倒置显微镜、免疫荧光、HE染色和扫描电镜的方法进行检测,观察角膜内皮细胞在培养板和肾纤维囊上的生长情况.结果 角膜内皮细胞在肾纤维囊上快速贴壁生长并增殖,细胞形态为多角形或六边形,多次传代后细胞仍维持原有的形态和功能,细胞能长期培养.在培养板上培养的角膜内皮细胞贴壁生长和增殖情况稍差.结论 角膜内皮细胞在脱细胞的肾纤维囊载体上生长良好,细胞形态结构明显.本研究为角膜内皮细胞的体外培养提供了简单和高效的方法.

  19. Pathological study of experimental infection with Enterococcus faecalis in quails

    Directory of Open Access Journals (Sweden)

    M. G. Al-hamdany

    2013-06-01

    Full Text Available This study was carried to isolate and identificate of Enterococcus. faecalis from small intestine and cecum of quails by culturing on differential and selective media. The concentration of E. faecalis suspension was fixed for experimental infection. Quails divided randomly into four groups, the first group considered as control group, the other groups injected with 0.5 ml of bacterial suspension as following: second group 1X108 CFU, the third group injected with 1X109 CFU, and the forth group injected with 1X1010 CFU. The clinical signs and pathological changes of heart, liver and kidney were observed at 3, 7, 14 and 21 days after infection. The results showed identification of E. faecalis after culturing and isolation of it. The gross lesions represented by opacity of pericardium, heart hypertrophy and liver infarction, histopathological lesions include beginning of endocarditis, severe fatty changes with localized recent thrombus and severe necrosis in liver, and cell swelling of epithelium lining renal tubules and apoptosis in kidney. The histopathological changes were more severe at 3 and 7 days post infection. This study concludes that quails have a strong defense and immune mechanism despite the appearance of pathological changes with high concentrations of bacterial suspension which cause death in other animals such as mice and rats, also E.faecalis possesses the ability to induce apoptosis.

  20. BIOLOGICAL EFFECTS OF PULSED SHORT WAVE TREATMENT. AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Dogaru Gabriela

    2015-02-01

    Full Text Available Pulsed short waves are short electromagnetic waves emitted as intermittent trains with a fixed duration, separated by free intervals of variable duration. The biological effects of pulsed short waves could be explained according to most of the authors by an activation of cellular enzymatic reactions, a stimulation of energy metabolism, a stimulation of liver function, of adrenal gland function and of the reticulocyte system, changes in cell permeability, by an increase of peripheral blood flow through the enhancement of local vascularization. This research aimed to investigate the biological effects of exposure to pulsed short waves at different doses on the adrenal glands of experimental animals, by structural and ultrastructural studies. The study included 35 animals assigned to 4 groups. Group I included 10 experimental animals exposed to radiation at a dose of 1/80 impulses/sec, group II, 10 animals exposed to a dose of 4/400 impulses/sec, group III, 10 animals exposed to a dose of 6/600 impulses/sec, for 10 min/day, and the control group consisted of 5 unexposed animals. Structural and ultrastructural changes of adrenal glands induced by the dose of 4/400 impulses/sec, compared to the unexposed control group and the dose of 1/80 impulses/sec, include an intensification of protein synthesis processes, an enhancement of energy metabolism in providing the energy required for an increased production of hormones, an intensification of collagen fiber synthesis processes in the capsule, necessary for healing. It was demonstrated that this dose induced an intensification of hormone synthesis and secretion, a stimulation of adrenal function. At the dose of 6/600 cycles/sec, a slight diminution of hormone synthesis and secretion activity was found, which was not below the limits existing in the unexposed control group, but was comparable to group II. This dose is probably too strong for experimental animals, inducing them a state of stress. The

  1. Estrogen induces multiple regulatory B cell subtypes and promotes M2 microglia and neuroprotection during experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Benedek, Gil; Zhang, Jun; Bodhankar, Sheetal; Nguyen, Ha; Kent, Gail; Jordan, Kelley; Manning, Dustin; Vandenbark, Arthur A; Offner, Halina

    2016-04-15

    Sex hormones promote immunoregulatory effects on multiple sclerosis. The current study evaluated estrogen effects on regulatory B cells and resident CNS microglia during experimental autoimmune encephalomyelitis (EAE). Herein, we demonstrate an estrogen-dependent induction of multiple regulatory B cell markers indicative of IL-10 dependent as well as IFN-γ dependent pathways. Moreover, although estrogen pretreatment of EAE mice inhibited the infiltration of pro-inflammatory cells into the CNS, it enhanced the frequency of regulatory B cells and M2 microglia. Our study suggests that estrogen has a broad effect on the development of regulatory B cells during EAE, which in turn could promote neuroprotection.

  2. 先天性巨结肠患儿肠神经干细胞培养的实验研究%Experimental study of culturing enteric neural stem cells from gut in children with Hirschsprung's disease

    Institute of Scientific and Technical Information of China (English)

    胡书奇; 岳雷; 夏肇波; 朱利斌; 李仲荣

    2015-01-01

    目的 探索从人类先天性巨结肠患儿的扩张段肠管提取肠神经干细胞的可行性,为进一步开展先天性巨结肠的神经干细胞自体移植治疗研究提供依据.方法 利用1例先天性巨结肠手术切除的扩张段肠管,进行酶消化后,制成单细胞悬液,经体外培养形成神经球,并通过CCK8法检测肠神经干细胞在24 h、48 h、72 h、96 h、120 h和144 h六个时间点的OD值,绘制生长曲线,记录增殖情况,通过Nestin、GFAP和TUJ-1细胞免疫荧光化学染色对肠神经干细胞及其分化而来的神经元和神经胶质细胞进行鉴定.结果 来自扩张段肠管的单细胞悬液通过原代体外培养10d,可见神经球形成;肠神经球随时间逐渐变大,CCK8法观察肠神经干细胞的OD值随时间而逐渐增高;形成的神经球可以继续传代,经细胞免疫荧光化学染色为Nestin染色阳性,并可分化为神经胶质细胞(GFAP染色阳性)和神经元细胞(TUJ-1染色阳性).结论 能从人类先天性巨结肠患儿的扩张段肠管提取具有自我更新能力的肠神经干细胞,可用于先天性巨结肠的神经干细胞自体移植治疗研究.%Objective To explore the possibility of isolating and culturing in vitro enteric neural stem cells from gut in children with Hirschsprung’s disease (HD) and provide experimental rationales for treating HD with neural stem cell transplantation.Methods Human gut samples were obtained from one child aged 1 l months after pull-through surgery due to HD.After enzyme digestion, single cell suspensions were isolated from postnatal human myenteric plexus.The cells were seeded into serum-free medium and generated neurospherelike bodies in vitro.Cell proliferation was observed by the curve of optic density (OD) from CCK8 test at the timepoints of 24, 48, 72, 96, 120 and 144h and growth curve diagram plotted.And neurospheres and differentiated cells with immunofluorescent staining of nestin were identified by neuron

  3. Advances in Experimental Studies on Treatment of Psoriasis by Traditional Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    张洪儒; 瞿幸

    2002-01-01

    @@ Psoriasis is a chronic and recurrent dermatosis marked by excessive hyperplasia of epidermal cells. The cause and pathogenesis are unknown. In the last few years, traditional Chinese medicine (TCM) has manifested its strength in treating psoriasis. In order to delve into the mechanism governing the TCM treatment of psoriasis, some clinical and experimental studies were carried out. The following is a review of the advance of the studies since the 1990's.Effects on Proliferation and Differentiation of Keratinocytes (Epithelial Cells)

  4. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Lavelle, John; Kofoed, Jens Peter

    This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010.......This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010....

  5. Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells Intoxicação experimental por Senecio brasiliensis em bovinos: estudo quantitativo e semi-quantitativo da matrix extracelular e de células sinusoidais do fígado

    Directory of Open Access Journals (Sweden)

    Márcia Bersane A.M. Torres

    2008-01-01

    Full Text Available Extracellular matrix plays an important role in chronic hepatic lesions and has been studied in experimental intoxication models. However in cattle, studies on chronic disease have focused on the hepatocellular damage and extracellular matrix (ECM changes are usually overlooked. There are no specific studies on the hepatic ECM in either normal or chronically damaged bovine liver. Thus an experimental model of hepatic toxicity model using Senecio brasiliensis poisoned calves was designed. Senecio brasiliensis contains pyrrolizidine alkaloids which cause either acute or chronic progressive dose dependent liver damage. Five calves were orally fed with 0.38g of dry leaves of S. brasiliensis/kg/day for 24 days. Liver needle biopsy specimens were obtained every 15 days for 60 days. Clinical signs of digestive complications appeared at 3rd week. One calf died on 45th day and four were evaluated up to 60th day. Biopsy samples were processed for routine light microscopy, immuno-histochemistry and transmission electron microscopy. From 30th day on progressive liver damage characterized by hepatocellular ballooning, necrosis, apoptosis and megalocytosis, centrilobular, pericellular and portal fibrosis were seen by light microscopy. Quantitative and semi-quantitative measurements of hepatic ECM components were performed before and after the onset of lesions. Morphometric analysis of total collagen and elastic fiber system was conducted. Total collagen and I and III collagen types progressively increased in throughout the liver of affected calves. Changes in location, amount and disposition of the elastic fiber system were also observed. Then numbers of Kupffer cells were significantly increased at 30th day and total numbers of sinusoidal cells were significantly increased at 45th and 60th days. Liver damage was progressive and irreversible even after the exposure to the plant was discontinued. Severe fibrotic lesions occurred mainly in portal tracts

  6. Experimental study on the deformation of erythrocytes under optically trapping and stretching

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.P. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave., Singapore 639798 (Singapore); Li Chuan [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave., Singapore 639798 (Singapore)]. E-mail: mcli@ntu.edu.sg; Lai, A.C.K. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave., Singapore 639798 (Singapore)

    2006-05-15

    The mechanical behavior of erythrocytes is studied experimentally and numerically. In the experiment, prepared silica microbeads are attached to the surface of spherically swollen erythrocytes (red blood cells, RBCs) at room temperature (25 deg. C). The cells are then stretched by single laser beam via the microbeads. The relation of deformation and stretching force is quantitatively assessed by the image processing of digital pictures. Meanwhile, a physical model for an axisymmetric cell is introduced to study its deformation by different level of stretching force. By comparing the experimental and numerical data, stiffness of the cell membrane can be determined and the optimal values are found to agree with other studies by different techniques such as micropipette aspiration or high frequency electric field.

  7. HSP70 mediates survival in apoptotic cells-Boolean network prediction and experimental validation.

    Science.gov (United States)

    Vasaikar, Suhas V; Ghosh, Sourish; Narain, Priyam; Basu, Anirban; Gomes, James

    2015-01-01

    Neuronal stress or injury results in the activation of proteins, which regulate the balance between survival and apoptosis. However, the complex mechanism of cell signaling involving cell death and survival, activated in response to cellular stress is not yet completely understood. To bring more clarity about these mechanisms, a Boolean network was constructed that represented the apoptotic pathway in neuronal cells. FasL and neurotrophic growth factor (NGF) were considered as inputs in the absence and presence of heat shock proteins known to shift the balance toward survival by rescuing pro-apoptotic cells. The probabilities of survival, DNA repair and apoptosis as cellular fates, in the presence of either the growth factor or FasL, revealed a survival bias encoded in the network. Boolean predictions tested by measuring the mRNA level of caspase-3, caspase-8, and BAX in neuronal Neuro2a (N2a) cell line with NGF and FasL as external input, showed positive correlation with the observed experimental results for survival and apoptotic states. It was observed that HSP70 contributed more toward rescuing cells from apoptosis in comparison to HSP27, HSP40, and HSP90. Overexpression of HSP70 in N2a transfected cells showed reversal of cellular fate from FasL-induced apoptosis to survival. Further, the pro-survival role of the proteins BCL2, IAP, cFLIP, and NFκB determined by vertex perturbation analysis was experimentally validated through protein inhibition experiments using EM20-25, Embelin and Wedelolactone, which resulted in 1.27-, 1.26-, and 1.46-fold increase in apoptosis of N2a cells. The existence of a one-to-one correspondence between cellular fates and attractor states shows that Boolean networks may be employed with confidence in qualitative analytical studies of biological networks.

  8. Experimental study of bone marrow stromal cell sheet on the construction of tissue-engineered bone%应用骨髓基质细胞片层构建组织工程骨的实验研究

    Institute of Scientific and Technical Information of China (English)

    王玲玲; 李宁毅; 樊功为; 卜令学; 袁荣涛; 高振华; 邢士超

    2011-01-01

    Objective To invesligale the effecl of bone marrow slromal cell sheet on the conslruclion of tissue-engineered bone in dogs. Methods Bone marrow slromal cells ( BMSCs) were isolaled from iliac bone of dogs with the melhod of density gradienl cenlrifu galion in vitro. Demineralized bone malrix( DBM) were prepared from homologuous bone. DBM was composiled wilh recombination hu man bone morphogenelic prolein-2( rhBMP-2). BMSCs induced by osleogenic DMEM al passage 3 were incubaled in the lemperalure responsive culture dish to make the BMSCs cell sheel. BMSCs cell sheel combined wilh DBM/rhBMP-2/BMSCs was implanted around the vessels of lattisimus dorsi muscle on the left side in the experiment group, and DBM/rhBMP-2/BMSCs without BMSCs cell sheet was implanted around the vessels of lattisimus dorsi muscle on the right side in the control group. 8,12,16 weeks after operation, the bone formation was investigated by histological observation. Results Osteogenesis result was experimental group > control group. Newly formed bone tissue in two groups were significantly different( P < 0. 05). 16 weeks after operation, a large number of lamellar bone and haversian system formed in experimental group,with red bone marrow in the bone marrow cavity. Lamellar bone formed in control group without haversian system and red bone marrow. Conclusions BMSCs cell sheet could promote the formation of tissue-engineered bone with dense lamellar bone and haversian system.%目的 探讨犬骨髓基质细胞(bone marrow stromal cells,BMSCs)片层在构建组织工程骨中的价值.方法 抽取犬髂骨骨髓,采用密度梯度离心法分离犬骨髓基质细胞(BMSCs).制备犬同种异体脱钙骨基质(dermineralized bone matrix,DBM).将人重组骨形态发生蛋白-2(recombination human bone morphogenetic protein-2,rhBMP-2)复合到DBM上.将经成骨诱导的第3代细胞接种于温度反应性培养皿中,制备BMSCs细胞片层.用得到的BMSCs细胞片层包裹DBM/rhBMP-2

  9. Regulatory T cell induction during Plasmodium chabaudi infection modifies the clinical course of experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Alessandro S Farias

    Full Text Available BACKGROUND: Experimental autoimmune encephalomyelitis (EAE is used as an animal model for human multiple sclerosis (MS, which is an inflammatory demyelinating autoimmune disease of the central nervous system characterized by activation of Th1 and/or Th17 cells. Human autoimmune diseases can be either exacerbated or suppressed by infectious agents. Recent studies have shown that regulatory T cells play a crucial role in the escape mechanism of Plasmodium spp. both in humans and in experimental models. These cells suppress the Th1 response against the parasite and prevent its elimination. Regulatory T cells have been largely associated with protection or amelioration in several autoimmune diseases, mainly by their capacity to suppress proinflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we verified that CD4(+CD25(+ regulatory T cells (T regs generated during malaria infection (6 days after EAE induction interfere with the evolution of EAE. We observed a positive correlation between the reduction of EAE clinical symptoms and an increase of parasitemia levels. Suppression of the disease was also accompanied by a decrease in the expression of IL-17 and IFN-γ and increases in the expression of IL-10 and TGF-β1 relative to EAE control mice. The adoptive transfer of CD4(+CD25(+ cells from P. chabaudi-infected mice reduced the clinical evolution of EAE, confirming the role of these T regs. CONCLUSIONS/SIGNIFICANCE: These data corroborate previous findings showing that infections interfere with the prevalence and evolution of autoimmune diseases by inducing regulatory T cells, which regulate EAE in an apparently non-specific manner.

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

    Science.gov (United States)

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

    2016-12-01

    We investigated a bacterial sample preparation procedure for single-cell studies. In the present study, we examined whether single bacterial cells obtained via 10-fold dilution followed a theoretical Poisson distribution. Four serotypes of Salmonella enterica, three serotypes of enterohaemorrhagic Escherichia coli and one serotype of Listeria monocytogenes were used as sample bacteria. An inoculum of each serotype was prepared via a 10-fold dilution series to obtain bacterial cell counts with mean values of one or two. To determine whether the experimentally obtained bacterial cell counts follow a theoretical Poisson distribution, a likelihood ratio test between the experimentally obtained cell counts and Poisson distribution which parameter estimated by maximum likelihood estimation (MLE) was conducted. The bacterial cell counts of each serotype sufficiently followed a Poisson distribution. Furthermore, to examine the validity of the parameters of Poisson distribution from experimentally obtained bacterial cell counts, we compared these with the parameters of a Poisson distribution that were estimated using random number generation via computer simulation. The Poisson distribution parameters experimentally obtained from bacterial cell counts were within the range of the parameters estimated using a computer simulation. These results demonstrate that the bacterial cell counts of each serotype obtained via 10-fold dilution followed a Poisson distribution. The fact that the frequency of bacterial cell counts follows a Poisson distribution at low number would be applied to some single-cell studies with a few bacterial cells. In particular, the procedure presented in this study enables us to develop an inactivation model at the single-cell level that can estimate the variability of survival bacterial numbers during the bacterial death process. PMID:27554145

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

    Science.gov (United States)

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

    2016-12-01

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

  12. Experimental Methodology used by Cell Cultures Laboratory from INRMFB to assess the therapeutic effect of natural factors

    OpenAIRE

    Munteanu Constantin; Munteanu Diana

    2010-01-01

    The experimental study design on cell cultures allows the direct biological evaluation at the cellular level, of the therapeutic effect that natural factors can play over the organism.Techniques for obtaining cell cultures requires a complex and laborious task that starts from live tissue sampling, continuous with isolation of cells and their preparation for sowing a culture plate. This preparation involves mechanical and enzymatic action from the researcher on biological material. Derived ce...

  13. Experimental investigations and modeling of direct internal reforming of biogases in tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lanzini, A.; Leone, P.; Pieroni, M.; Santarelli, M. [Dipartimento di Energetica, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10129, Torino (Italy); Beretta, D.; Ginocchio, S. [Centro Ricerca e Sviluppo, Edison S.p.a, Via La Pira 2, IT-10028 Trofarello, Torino (Italy)

    2011-10-15

    Biogas-fed Solid Oxide Fuel Cell (SOFC) systems can be considered as interesting integrated systems in the framework of distributed power generation. In particular, bio-methane and bio-hydrogen produced from anaerobic digestion of organic wastes represent renewable carbon-neutral fuels for high efficiency electrochemical generators. With such non-conventional mixtures fed to the anode of the SOFC, the interest lies in understanding the multi-physics phenomena there occurring and optimizing the geometric and operation parameters of the SOFC, while avoiding operating and fuel conditions that can lead to or accelerate degradation processes. In this study, an anode-supported (Ni-YSZ) tubular SOFC was considered; the tubular geometry enables a relatively easy separation of the air and fuel reactants and it allows one to evaluate the temperature field of the fuel gas inside the tube, which is strictly related to the electrochemical and heterogeneous chemical reactions occurring within the anode volume. The experiments have been designed to analyze the behavior of the cell under different load and fuel utilization (FU) conditions, providing efficiency maps for both fuels. The experimental results were used to validate a multi-physics model of the tubular cell. The model showed to be in good agreement with the experimental data, and was used to study the sensitive of some selected geometrical parameters modification over the cell performances. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Experimental Cosserat elasticity in open-cell polymer foam

    Science.gov (United States)

    Rueger, Zach; Lakes, Roderic S.

    2016-01-01

    Reticulated open-cell polymer foams exhibit substantial size effects in torsion and bending: slender specimens are more rigid than anticipated via classical elasticity. Such size effects are predicted by Cosserat (micropolar) elasticity, which allows points to rotate as well as translate and incorporates distributed moments (couple stresses). The Cosserat characteristic length is larger than the cell size. The Cosserat coupling coefficient is larger than in dense closed-cell foams and approaches 1 for foam with 0.4 mm cells.

  15. 毛乳头细胞促进组织工程皮肤血管化的实验研究%EXPERIMENTAL STUDY ON DERMAL PAPILLARY CELLS IMPROVING VASCULARIZATION OF TISSUE ENGINEERED SKIN SUBSTITUTES

    Institute of Scientific and Technical Information of China (English)

    刘坡; 祁少海; 舒斌; 谢举临; 徐盈斌; 刘旭盛

    2012-01-01

    Objective To investigate the impact of dermal papillary cells on vascularization of tissue engineered skin substitutes consisting of epidermal stem cells and allogeneic acellular dermal matrix. Methods Human foreskins from routine circumcisions were collected to separate epidermal cells by using dispase with trypsogen. Collagen type IV was used to isolate epidermal stem cells from the 2nd and 3rd passage keratinocytes. Dermal papilla was isolated by the digestion method of collagenase I from fetus scalp and cultured in routine fibroblast medium. Tissue engineered skin substitutes were reconstructed by seeding epidermal stem cells on the papillary side of allogeneic acellular dermis with (the experimental group) or without (the control group) seeding dermal papillary cells on the reticular side. The two kinds of composite skin substitutes were employed to cover skin defects (1 cm×1 cm in size) on the back of the BALB/C-nu nude mice (n=30). The grafting survival rate was recorded 2 weeks after grafting. HE staining and immunohistochemistry method were employed to determine the expression of CD31 and calculate the microvessel density at 2 and 4 weeks after grafting. Results Those adhesion cells by collagen type IV coexpressed Keratin 19 and β1 integrin, indicating that the cells were epidermal stem cells. The cultivated dermal papillary cells were identified by expressing high levels of a-smooth muscle actin. The grafting survival rate was significantly higher in experimental group (28/30, 93.3%), than that in control group (24/30, 80.0%). HE staining showed that the epithelial layer in experimental group was 12-layered with large epithelial cells in the grafted composite skin, and that the epithelial layer in control group was 4-6-layered with small epithelial cells. At 2 and 4 weeks after grafting, the microvessel density was (38.56 ± 2.49)/mm2 and (49.12 ± 2.39)/mm2 in experimental group and was (25.16 ± 3.73)/mm2 and (36.26 ± 3.24)/mm2 in control group

  16. Numerical and experimental study of the effects of the electrical resistance and diffusivity under clamping pressure on the performance of a metallic gas-diffusion layer in polymer electrolyte fuel cells

    Science.gov (United States)

    Tanaka, Shiro; Bradfield, Warwick W.; Legrand, Cloe; Malan, Arnaud G.

    2016-10-01

    The performance of a perforated metal-sheet gas-diffusion layer incorporated with a microporous layer in a fuel cell is evaluated with fine-pitch channel/land designs for the gas flow field on a bipolar plate. The combination of metal-sheet gas-diffusion layer and microporous layer exhibits significant performance without a large flooding effect. When comparing the performance with wider and narrower land cases, the land width affects the performance. To investigate the roles of the microporous layer, land width, etc. in the fuel cell with the metal-sheet gas-diffusion layer, a single-phase, isothermal, and multi-physics simulation is developed and coupled with electrical, mechanical, electrochemical and fluid dynamics factors. The simulated current-voltage performance is then compared to the experimentally measure performance. These are shown to be in good agreement apart for very high current-density cases i.e. greater than 1.5 A cm-2. This is due the flooding effect predominantly appearing. It is further demonstrated that the microporous layer serves as the key component in facilitating gas diffusion and for preventing flooding. Furthermore, the pressure is found to have a strong impact on the performance, affecting the gas diffusion and electric resistance around the microporous layer.

  17. Intraperitoneal Infusion of Mesenchymal Stem/Stromal Cells Prevents Experimental Autoimmune Uveitis in Mice

    Directory of Open Access Journals (Sweden)

    Joo Youn Oh

    2014-01-01

    Full Text Available Autoimmune uveitis is one of the leading causes of blindness. We here investigated whether intraperitoneal administration of human mesenchymal stem/stromal cells (hMSCs might prevent development of experimental autoimmune uveitis (EAU in mice. Time course study showed that the number of IFN-γ- or IL-17-expressing CD4+ T cells was increased in draining lymph nodes (DLNs on the postimmunization day 7 and decreased thereafter. The retinal structure was severely disrupted on day 21. An intraperitoneal injection of hMSCs at the time of immunization protected the retina from damage and suppressed the levels of proinflammatory cytokines in the eye. Analysis of DLNs on day 7 showed that hMSCs decreased the number of Th1 and Th17 cells. The hMSCs did not reduce the levels of IL-1β, IL-6, IL-12, and IL-23 which are the cytokines that drive Th1/Th17 differentiation. Also, hMSCs did not induce CD4+CD25+Foxp3+ cells. However, hMSCs increased the level of an immunoregulatory cytokine IL-10 and the population of IL-10-expressing B220+CD19+ cells. Together, data demonstrate that hMSCs attenuate EAU by suppressing Th1/Th17 cells and induce IL-10-expressing B220+CD19+ cells. Our results support suggestions that hMSCs may offer a therapy for autoimmune diseases mediated by Th1/Th17 responses.

  18. The Contribution of Immune and Glial Cell Types in Experimental Autoimmune Encephalomyelitis and Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Samuel S. Duffy

    2014-01-01

    Full Text Available Multiple sclerosis (MS is a chronic inflammatory disease of the central nervous system characterised by widespread areas of focal demyelination. Its aetiology and pathogenesis remain unclear despite substantial insights gained through studies of animal models, most notably experimental autoimmune encephalomyelitis (EAE. MS is widely believed to be immune-mediated and pathologically attributable to myelin-specific autoreactive CD4+ T cells. In recent years, MS research has expanded beyond its focus on CD4+ T cells to recognise the contributions of multiple immune and glial cell types to the development, progression, and amelioration of the disease. This review summarises evidence of T and B lymphocyte, natural killer cell, macrophage/microglial, astrocytic, and oligodendroglial involvement in both EAE and MS and the intercommunication and influence of each cell subset in the inflammatory process. Despite important advances in the understanding of the involvement of these cell types in MS, many questions still remain regarding the various subsets within each cell population and their exact contribution to different stages of the disease.

  19. Mouse CD11b+Gr-1+ myeloid cells can promote Th17 cell differentiation and experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Yi, Huanfa; Guo, Chunqing; Yu, Xiaofei; Zuo, Daming; Wang, Xiang-Yang

    2012-11-01

    Myeloid-derived suppressor cells (MDSCs) have been a focus of recent study on tumor-mediated immune suppression. However, its role in Th17 cell differentiation and the pathogenesis of autoimmune diseases (e.g., multiple sclerosis) has not been determined. We show in this study that development of experimental autoimmune encephalomyelitis (EAE) in mice is associated with a profound expansion of CD11b(+)Gr-1(+) MDSCs, which display efficient T cell inhibitory functions in vitro. Unexpectedly, these MDSCs enhance the differentiation of naive CD4(+) T cell precursors into Th17 cells in a highly efficient manner under Th17-polarizing conditions, as indicated by significantly increased number of Th17 cells, elevation of IL-17A production, and upregulation of the orphan nuclear receptor RORA and RORC. Mechanistic studies show that IL-1β represents a major mediator of MDSC-facilitated Th17 differentiation, which depends on the IL-1 receptor on CD4(+) T cells but not MDSCs. Selective depletion of MDSCs using gemcitabine results in a marked reduction in the severity of EAE (e.g., decreased clinical scores and myelin injury), which correlates with reduced Th17 cells and inflammatory cytokines (IL-17A and IL-1β) in the lymphoid tissues and spinal cord. Adoptive transfer of MDSCs after gemcitabine treatment restores EAE disease progression. Together, we demonstrate for the first time, to our knowledge, that excessive and prolonged presence of MDSCs can drive a Th17 response and consequently contributes to the pathogenesis of EAE. These new findings provide unique insights into the pleiotropic functions of MDSCs and may help explain the failure of immunosuppressive MDSCs to control Th17/IL-17-dependent autoimmune disorders.

  20. Experimental study on the characteristics of semiconductor opening switch

    CERN Document Server

    Su Jian Cang; Ding Yong Zhong; Song Zhi Min; Ding Zhen Jie; Liu Guo Zhi

    2002-01-01

    An experimental set-up is developed to measure the characteristics of semiconductor opening switch (SOS). The parameters, such as interruption impedance, current int eruption time, voltage gain, pulse duration and energy transfer efficiency, are studied experimentally. The experimental results show that forward pumping time and reverse pumping time are important parameters for semiconductor opening switches. The influences of forward pumping time and reverse pumping time on interruption time, voltage gain, and energy transfer efficiency are obtained. In the interruption process, the impedance variation is divided into three phases: that is rapid increasing phase, slow change phase and completely interruption phase

  1. The false memory syndrome: Experimental studies and comparison to confabulations

    OpenAIRE

    Mendez, M F; Fras, I.A.

    2010-01-01

    False memories, or recollections that are factually incorrect but strongly believed, remain a source of confusion for both psychiatrists and neurologists. We propose model for false memories based on recent experimental investigations, particularly when analyzed in comparison to confabulations, which are the equivalent of false memories from neurological disease. Studies using the Deese/Roedinger–McDermott experimental paradigm indicate that false memories are associated with the need for com...

  2. Proliferative response of mouse spermatogonial stem cells after irradiation: a quantitative model analysis of experimental data

    International Nuclear Information System (INIS)

    The testes of CDF1 mice were irradiated with single doses of X-rays ranging from 2-16 Gy. The number of haploid cells in the testis at different times after irradiation (42-350 days) was determined by one-parameter flow cytometry both for irradiated animals and for age-matched controls. Based on literature data on the kinetics of the spermatogenesis in mice, a mathematical model of the (hierarchical) germ tissue was developed. Using this model, the processes of radiation-induced cell loss and subsequent recovery were simulated and free parameters of the model were estimated by fitting the model prediction to the experimental data. One of the aims of the study was to investigate the kinetic behaviour of spermatogonial stem cells and the corresponding control mechanisms. (author)

  3. Liquid Fluoride Salt Experimentation Using a Small Natural Circulation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoder Jr, Graydon L [ORNL; Heatherly, Dennis Wayne [ORNL; Williams, David F [ORNL; Elkassabgi, Yousri M. [Texas A& M University, Kingsville; Caja, Joseph [Electrochemical Systems, Inc.; Caja, Mario [ORNL; Jordan, John [Texas A& M University, Kingsville; Salinas, Roberto [Texas A& M University, Kingsville

    2014-04-01

    A small molten fluoride salt experiment has been constructed and tested to develop experimental techniques for application in liquid fluoride salt systems. There were five major objectives in developing this test apparatus: Allow visual observation of the salt during testing (how can lighting be introduced, how can pictures be taken, what can be seen) Determine if IR photography can be used to examine components submerged in the salt Determine if the experimental configuration provides salt velocity sufficient for collection of corrosion data for future experimentation Determine if a laser Doppler velocimeter can be used to quantify salt velocities. Acquire natural circulation heat transfer data in fluoride salt at temperatures up to 700oC All of these objectives were successfully achieved during testing with the exception of the fourth: acquiring velocity data using the laser Doppler velocimeter. This paper describes the experiment and experimental techniques used, and presents data taken during natural circulation testing.

  4. Cell death during the postnatal morphogenesis of the normal rabbit kidney and in experimental renal polycystosis.

    Science.gov (United States)

    García-Porrero, J A; Ojeda, J L; Hurlé, J M

    1978-01-01

    We have studied, by means of optic and electron microscopy, the normal and abnormal cell death that takes place during the postnatal morphogenesis of rabbit kidney, and in the experimental renal polycystosis produced by methylprednisolone acetate. In the normal kidney intertubular cell death can be observed during the first 20 days of the postnatal development. However, cell death in the normal metanephric blastema is a very rare event. In the polycystic kidney numerous dead cells can be seen between the third and forty eighth days after injection. The topography and morphology of the dead cells depend on the stage in the evolution of the disease. In the 'stage of renal immaturity', dying and dead cells are present in the nephrogenic tissue, in the dilating collecting tubules and in the intertubular spaces. In this stage the cellular pathology is essentially nuclear. In the stage of tubular cysts, the dead cells are mostly located in the walls of cysts, with some dead cells, but mostly cellular debris in their lumina. At this stage the cellular pathology is basically cytoplasmic. The dead cells are eventually digested by what appear to be phagocytes of tubular epithelial origin. It is suggested that cell death is an important factor in the evolution of the lesions of renal polycystosis induced by corticosteroids, and probably in the initiation of the pathological process as well. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 PMID:670065

  5. Activation of endogenous neural stem cells in experimental intracerebral hemorrhagic rat brains

    Institute of Scientific and Technical Information of China (English)

    唐涛; 黎杏群; 武衡; 罗杰坤; 张花先; 罗团连

    2004-01-01

    Background Many researchers suggest that adult mammalian central nervous system (CNS) is incapable of completing self-repair or regeneration. And there are accumulating lines of evidence which suggest that endogenous neural stem cells (NSCs) are activated in many pathological conditions, including stroke in the past decades, which might partly account for rehabilitation afterwards. In this study, we investigated whether there was endogenous neural stem cell activation in intracerebral hemorrhagic (ICH) rat brains.Methods After ICH induction by stereotactical injection of collagenase type Ⅶ into globus pallidus, 5-Bromo-2 Deoxyuridine (BrdU) was administered intraperitoneally to label newborn cells. Immunohistochemical method was used to detect Nestin, a marker for neural stem cells, and BrdU.Results Nestin-positive or BrdU-Labeled cells were predominantly located at 2 sites: basal ganglion around hemotoma, ependyma and nearby subventricular zone (SVZ). No positive cells for the 2 markers were found in the 2 sites of normal control group and sham group, as well as in non-leisoned parenchyma, both hippocampi and olfactory bulbs in the 4 groups. Nestin+ cells presented 4 types of morphology, and BrdU+ nucleus were polymorphologic. Postive cell counting around hemotoma showed that at day 2, Nestin+ cells were seen around hemotoma in model group , the number of which increased at day 4, day 7(P<0.01), peaked at day 14(P<0.05), and reduced significantly by day 28(P<0.01).Conclusion Endogenous neural stem cells were activated in experimental intracerebral hemorrhagic rat brains.

  6. Experimental Methodology used by Cell Cultures Laboratory from INRMFB to assess the therapeutic effect of natural factors

    Directory of Open Access Journals (Sweden)

    Munteanu Constantin

    2010-11-01

    Full Text Available The experimental study design on cell cultures allows the direct biological evaluation at the cellular level, of the therapeutic effect that natural factors can play over the organism.Techniques for obtaining cell cultures requires a complex and laborious task that starts from live tissue sampling, continuous with isolation of cells and their preparation for sowing a culture plate. This preparation involves mechanical and enzymatic action from the researcher on biological material. Derived cell cultures are monitored morphologically by high-performance inverted biological microscope, with video camera for image acquisition. In the final stage, the cells are scraped, and through biochemical and molecular techniques, the therapeutic efficiency hypothesis of the investigated natural factor is verified experimentally. The cell cultures can be crioconservated in special containers with liquid nitrogen.

  7. Islet-like cell aggregates generated from human adipose tissue derived stem cells ameliorate experimental diabetes in mice.

    Directory of Open Access Journals (Sweden)

    Vikash Chandra

    Full Text Available BACKGROUND: Type 1 Diabetes Mellitus is caused by auto immune destruction of insulin producing beta cells in the pancreas. Currently available treatments include transplantation of isolated islets from donor pancreas to the patient. However, this method is limited by inadequate means of immuno-suppression to prevent islet rejection and importantly, limited supply of islets for transplantation. Autologous adult stem cells are now considered for cell replacement therapy in diabetes as it has the potential to generate neo-islets which are genetically part of the treated individual. Adopting methods of islet encapsulation in immuno-isolatory devices would eliminate the need for immuno-suppressants. METHODOLOGY/PRINCIPAL FINDINGS: In the present study we explore the potential of human adipose tissue derived adult stem cells (h-ASCs to differentiate into functional islet like cell aggregates (ICAs. Our stage specific differentiation protocol permit the conversion of mesodermic h-ASCs to definitive endoderm (Hnf3β, TCF2 and Sox17 and to PDX1, Ngn3, NeuroD, Pax4 positive pancreatic endoderm which further matures in vitro to secrete insulin. These ICAs are shown to produce human C-peptide in a glucose dependent manner exhibiting in-vitro functionality. Transplantation of mature ICAs, packed in immuno-isolatory biocompatible capsules to STZ induced diabetic mice restored near normoglycemia within 3-4 weeks. The detection of human C-peptide, 1155±165 pM in blood serum of experimental mice demonstrate the efficacy of our differentiation approach. CONCLUSIONS: h-ASC is an ideal population of personal stem cells for cell replacement therapy, given that they are abundant, easily available and autologous in origin. Our findings present evidence that h-ASCs could be induced to differentiate into physiologically competent functional islet like cell aggregates, which may provide as a source of alternative islets for cell replacement therapy in type 1 diabetes.

  8. Experimental study on the culture and transplantation of limbal epithelium cells of rabbit%兔角膜缘上皮细胞培养与移植的实验研究

    Institute of Scientific and Technical Information of China (English)

    罗廷浩

    2012-01-01

    OBJECTIVE To study the treatment of autotransplantation on rabbit limbal stem cells lack by cultured limbal epithelium cells cultured on gelatin. METHODS Limbal epithelium cells had been cultured on gelatin in DMEM/HamF12 medium for one week, and cultured limbal epithelium cell had been marked with 'HTDR for one day, then limbal epithelium cells and gelatin were transplanted on the limbal and scleral of the rabbit model with lack of corneal stem cells by autotransplantation. The corneal changes were observed by a slillamp every day, the corneal pathological changes and 3HTDR content were examined. RESULTS Rabbit limbal epithelium cells continued to proliferate, differentiate and form multiple cell layers on gelatin. After autotransplantation with cultured epithelium cells and gelatin the rabbit epithelium showed corneal phenotype and progressive decrease of vascularity and stromal infiltration in the limbal and peripheral zone. Pathological examination verified that the limbal and peripheral corneal epithelium was composed of multilayer cells; the neu-vascularization was reduced and stromal inflammatory cells were decreased. The limbal content 3HTDR by isotope radioisotope was examined four weeks after operation. CONCLUSIONS Transplantation with cultured limbal epithelium cells could restore the composition of corneal epithelial cell, decrease neo-vascularization, maintain the function of limbal cellular barrier and provide better condition for later keratoplasty.%目的 观察以明胶为裁体培养的角膜缘上皮细胞移植治疗兔角膜缘干细胞缺乏症的疗效.方法 切除实验兔角膜缘组织并用NaOH处理制作角膜缘干细胞缺乏动物模型,切除的角膜缘上皮细胞在铺有明胶裁体的细胞培养板上培养5d后(角膜上皮细胞移植术前24 h)用3H胸腺嘧啶核苷标记,于模型动物上行角膜缘上皮细胞移植术,术后观察角膜修复情况,并做病理学检查及同位素检测.结果 1.细胞培养:兔角

  9. Climatology Applied To Architecture: An Experimental Investigation about Internal Temperatures Distribution at Two Test Cells

    Directory of Open Access Journals (Sweden)

    Grace Tibério Cardoso

    2016-04-01

    Full Text Available Data were analyzed en relative spatial distribution of the internal surface temperature (IST and internal air temperature or dry bulb (TBS, in two different test cells, for a typical experimental day under the influence of tropical mass. The main goal of this research is to provide guidelines to collect temperature data experimentally since there is not an appropriate standard to guide this methodological procedure in buildings. The data series of dry bulb temperature and internal surface temperatures were measured in a test cell with a green roof and the other with conventional ceramic roof by thermocouples installed at predetermined locations. The data of solar radiation and the main climatic variables were recorded by the automatic weather station at the Center of Science Engineering Applied to the Environment (CCEAMA, School of Engineering of São Carlos (EESC-USP. The results led to the conclusion that the distribution of the internal surface temperature is almost uniform in the two test cells, but in relation to the dry bulb temperature there is a small vertical temperature gradient in the conventional cell. This work will contribute significantly to future studies in the area of human comfort and environmental suitability of buildings

  10. Study on the Renal Anemia: Experimental Study in Acute Renal Anemia

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Zo Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1969-09-15

    The double tracer study on erythrokinetics was carried out experimentally with radioactive iron({sup 59}Fe) and chromium ({sup 51}Cr) in rabbits. The 0.1% cantharidin solution and 1% pot. perchlomate solution was given subcutaneously to 20 rabbits respectively. 3 and 6 days after injection, the blood chemistry, urine examination, ferrokinetics and apparent half survival time of RBC were ({sup 51}Cr T-1/2) determined. Following were the results: 1) Red blood cell hematocrit and hemoglobin values were moderately reduced and B.U.N. and serum creatinine values were slightly increased in the cantharidin group, while B.U.N. and serum creatinine values were within normal limits in the pot. perchlomate group. Reticulocyte values were slightly increased in the cantharidin group, while was normal range in the pot. perchlomate group. 2) Blood chemistry finding was not significant statistically in both experimental groups, but serum iron value was moderately reduced in both group. 3) Plasma volume was unchanged in both group, but red cell volume and whole blood volume were slightly reduced in both groups. 4) Results of ferrokinetics were as follows: i) The plasma iron disappearance rate was delayed in both groups. Plasma iron turnover rate, red cell iron utilization and red cell iron turnover rate were decreased in both groups, and then red cell iron turnover rate was more decreased than plasma iron turnover rate in both groups. Circulating red cell iron was slightly increased in cantharidin group and red cell iron concentration was within normal range in both groups. ii) P.I.T.R.-R.C.I.T. value moderately increased in the cantharidin group and slightly increased in the pot. perchlomate group. Reticulocyte index, red cell iron turnover index, plasma iron turnover index and effective erythropoiesis index were wholly reduced in both groups. iii) The red cell life span was slightly shortened in the cantharidin group while was within normal range in pot. perchlomate group. The

  11. An experimental study into the bilinear oscillator close to grazing

    Energy Technology Data Exchange (ETDEWEB)

    Ing, J; Pavlovskaia, E; Wiercigroch, M [Centre for Applied Dynamics Research, Department of Engineering, King' s College, University of Aberdeen, Aberdeen, AB24 3UE (United Kingdom)], E-mail: j.ing@abdn.ac.uk

    2008-02-15

    A linear oscillator undergoing impact with a secondary support is studied experimentally. Smooth as well as nonsmooth bifurcations are observed. The bifurcations are explained with help from simulations based on mapping solutions between locally smooth subspaces. Experimental stability studies are also presented, justifying the normal form maps used to show the response close to grazing for systems with and without prestress of the secondary spring. The high degree of correspondence lends support to the modelling approach, and the highly complicated response justifies continued study of this system.

  12. An experimental study into the bilinear oscillator close to grazing

    International Nuclear Information System (INIS)

    A linear oscillator undergoing impact with a secondary support is studied experimentally. Smooth as well as nonsmooth bifurcations are observed. The bifurcations are explained with help from simulations based on mapping solutions between locally smooth subspaces. Experimental stability studies are also presented, justifying the normal form maps used to show the response close to grazing for systems with and without prestress of the secondary spring. The high degree of correspondence lends support to the modelling approach, and the highly complicated response justifies continued study of this system

  13. An experimental study into the bilinear oscillator close to grazing

    Science.gov (United States)

    Ing, J.; Pavlovskaia, E.; Wiercigroch, M.

    2008-02-01

    A linear oscillator undergoing impact with a secondary support is studied experimentally. Smooth as well as nonsmooth bifurcations are observed. The bifurcations are explained with help from simulations based on mapping solutions between locally smooth subspaces. Experimental stability studies are also presented, justifying the normal form maps used to show the response close to grazing for systems with and without prestress of the secondary spring. The high degree of correspondence lends support to the modelling approach, and the highly complicated response justifies continued study of this system.

  14. Cancer stem cell: fundamental experimental pathological concepts and updates.

    Science.gov (United States)

    Islam, Farhadul; Qiao, Bin; Smith, Robert A; Gopalan, Vinod; Lam, Alfred K-Y

    2015-04-01

    Cancer stem cells (CSCs) are a subset of cancer cells which play a key role in predicting the biological aggressiveness of cancer due to its ability of self-renewal and multi-lineage differentiation (stemness). The CSC model is a dynamic one with a functional subpopulation of cancer cells rather than a stable cell population responsible for tumour regeneration. Hypotheses regarding the origins of CSCs include (1) malignant transformation of normal stem cells; (2) mature cancer cell de-differentiation with epithelial-mesenchymal transition and (3) induced pluripotent cancer cells. Surprisingly, the cancer stem cell hypothesis originated in the late nineteenth century and the existence of haematopoietic stem cells was demonstrated a century later, demonstrating that the concept was possible. In the last decade, CSCs have been identified and isolated in different cancers. The hallmark traits of CSCs include their heterogeneity, interaction with microenvironments and plasticity. Understanding these basic concepts of CSCs is important for translational applications using CSCs in the management of patients with cancer. PMID:25659759

  15. Co-evolution of conventions and networks : an experimental study

    NARCIS (Netherlands)

    Corten, R.; Buskens, V.W.

    2010-01-01

    We study the emergence of conventions in dynamic networks experimentally. Conventions are modeled in terms of coordination games in which actors can choose both their behavior and their interaction partners. We study how macro-level outcomes of the process in terms of Pareto-efficiency and heterogen

  16. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles

    2001-01-01

    The diagnostic difficulties, variability in outcome and the heterogeinity of the problem of orthopaedic infections stimulated the author to a study of the literature, and several clinical and experimental studies. The diagnosis prosthesis-related infection can only be reached with an acceptable d

  17. Ideas for Hypertensive Experimental Study Prevented and Treated by TCM

    Institute of Scientific and Technical Information of China (English)

    王振涛

    2004-01-01

    Hypertensive experimental studies prevented and treated by TCM are matured relevant studies of western medicine for reference, such as the hypotensive effect and elucidating its therapeutic mechanism. Comprehension in all literatures, most simple herbs and compound recipes show functions such as: Adjustment of renin-angiotensin-aldosterone system (RAAS), like angiotensin converting enzyme inhibitor (ACEI);

  18. Ideas for Hypertensive Experimental Study Prevented and Treated by TCM

    Institute of Scientific and Technical Information of China (English)

    王振涛

    2004-01-01

    @@ Hypertensive experimental studies prevented and treated by TCM are matured relevant studies of western medicine for reference,such as the hypotensive effect and elucidating its therapeutic mechanism.Comprehension in all literatures, most simple herbs and compound recipes show functions such as: Adjustment of renin-angiotensin-aldosterone system (RAAS), like angiotensin converting enzyme inhibitor (ACEI);

  19. Experimental Studies on Electronic Portfolios in Turkey: A Literature Review

    Science.gov (United States)

    Alan, Selahattin; Sünbül, Ali Murat

    2015-01-01

    In this study, a literature review was conducted about an individual's selected efforts, products stored in electronic format, and electronic portfolios that reflect the development and capacity of multimedia systems. In this context, relevant experimental studies performed in Turkey are collected to show e-portfolio application forms, their…

  20. Experimental investigation of air relative humidity (RH) cycling tests on MEA/cell aging in PEMFC. Pt. II. Study of low RH cycling test with air RH at 62%/0%

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.T.; Chatillon, Y.; Bonnet, C.; Lapicque, F. [Laboratoire Reactions et Genie des Procedes, CNRS-Nancy University, Nancy (France); Leclerc, S. [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, CNRS-Nancy University, Vandoeuvre-les-Nancy (France); Hinaje, M.; Rael, S. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Nancy University, Vandoeuvre-les-Nancy (France)

    2012-06-15

    The effect of low relative humidity (RH) cycling (RH{sub C} 62%/0%) on the degradation mechanisms of a single proton exchange membrane fuel cell (5 x 5 cm{sup 2}) was investigated and compared to a cell operated at constant humidification (RH{sub C} = 62%). The overall cell performance loss was near 33 {mu}V h{sup -1}, which is greater than the voltage decay under constant RH condition near 3 {mu}V h{sup -1}. The electroactive surface was reduced but to an acceptable level. Impedance spectroscopy revealed that the ohmic and charge transfer resistances were reduced by the likely improved hydration of the ionomeric layer at the catalyst due to hydrogen crossover. This was so important that H{sub 2} starvation was finally responsible for the collapse of the cell after 650 h. Transmission electron microscopy showed occurrence of various phenomena, e.g., bubbles and pinholes formation in the membrane due to local overheat from hydrogen combustion at the cathode, and thickness reduction of catalytic layers. The water up take obtained by {sup 1}H NMR within the membrane electrode assembly (MEA) after low RH cycling reduced by 24% compared to a fresh MEA. Observations are also compared to those obtained at high RH cycling (RH{sub C} 62%/100%) presented in Part I of this study [1]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. The Emerging Roles of Gamma–Delta T Cells in Tissue Inflammation in Experimental Autoimmune Encephalomyelitis

    Science.gov (United States)

    Malik, Sakshi; Want, Muzamil Yaqub; Awasthi, Amit

    2016-01-01

    γδ (gamma–delta) T cells, a small population of unconventional T cells, have been found in central nervous system lesions of multiple sclerosis (MS) patients, but their function in disease activity is not clearly understood. Previous studies in experimental autoimmune encephalomyelitis (EAE) were inconsistent in identifying their specific roles in suppressing or promoting disease pathogenesis. Emerging advancements in the biology of γδ T cells especially in the context of their being the major initial producers of IL-17, suggested their crucial role in pathogenesis of EAE. In addition, γδ T cells express high levels of IL-23R and IL-1R, which further enhance their effector functions in the pathogenesis of EAE. Nonetheless, activated heterogeneous γδ T cells display functional dichotomy, which is crucial in determining the outcomes of tissue inflammation in EAE. In this review, we discussed recent advances in understanding the biology of γδ T cells in tissue inflammation as well as their roles in suppressing or promoting the development of EAE. PMID:26858718

  2. Cell proliferation during fractionated radiation in two experimental tumors

    International Nuclear Information System (INIS)

    Tumor cell proliferation kinetics after irradiation have been studied using the method of bromodeoxyuridine incorporation and flow cytometry. Labelling indices were obtained after single and multiple fractions of radiation in a mouse fibrosarcoma (FSa-II) and human squamous carcinoma (FADU) growing in nude mice. For 8 mm tumors mean L.I was 17.5 +- 2.6% and 21.5 + 3.2%, respectively. Both tumors showed a similar response to single dose of irradiation (10 and 20 Gy) with initial depression of labelling index and then a rapid increase after 3 days in the FSa-II tumors (mean L.I 24%) and 5 days in the FADU tumors (mean L.I 27%). During fractionated treatment, labelling index was dependent on dose per fraction (2.5-18 Gy) time interval between fractions and time of analysis. Tumors were biopsied during course of fractionated treatment to see if labelling index would act as a predictor of response. No significant difference could be determined between individual tumors that had received the same dose per fraction. However a labelling index the same or higher than control values were associated with lack of tumor control. Controlled tumors showed a significant depression of labelling index (rho<0.05)

  3. Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

    Directory of Open Access Journals (Sweden)

    Zi-Jie Chien

    2013-01-01

    Full Text Available This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2 as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines.

  4. Experimental Studies on Turbulence Kinetic Energy in Confined Vortex Flows

    Institute of Scientific and Technical Information of China (English)

    L.Yan; G.H.Vatistas; 等

    2000-01-01

    Turbulence kinetic energies in confined vortex flows have been studied.The studies were based on the experiments performed in a vortex chamber,In the experiments,a Laser Doppler Anemometry(LDA) was used to perform flow measurements inside the vortex chamber,which provided the data for the kinetic energy analysis.The studies concentrated on the influences of the contraction ratio and the inlet air flow rate on the kinetic energy,and analyzed the characteristics of the kinetic energy in the confined vortex flows,including the distributions of the tangential component,radial component and total turbulence kinetic energy,In the paper,both the experimental techniques and the experimental results were presented.Based on a similarity analyis and the experimental data,an empirical scaling formula was proposed so that the tangential component of the turbulence kinetic energy was dependent only on the parameter of the contraction ratio.

  5. Morphology of the epithelial cells and expression of androgen receptor in rat prostate dorsal lobe in experimental hyperprolactinemia.

    OpenAIRE

    Marcin Wylot; Wojciech Głabowski; Maria Laszczyńska; Sylwia Słuczanowska-Głabowska

    2006-01-01

    The effect of hyperprolactinemia on the prostate has not been well investigated. Since androgens play an important role in prostate development, growth and function, the goal of the present study was to estimate the influence of hyperprolactinemia on expression of the androgen receptor (AR) in rat epithelial cells of prostate dorsal lobe and on morphology of these cells. Studies were performed on sexually mature male Wistar rats. The experimental group rats received metoclopramide (MCP) intra...

  6. Stochastic modeling and experimental analysis of phenotypic switching and survival of cancer cells under stress

    Science.gov (United States)

    Zamani Dahaj, Seyed Alireza; Kumar, Niraj; Sundaram, Bala; Celli, Jonathan; Kulkarni, Rahul

    The phenotypic heterogeneity of cancer cells is critical to their survival under stress. A significant contribution to heterogeneity of cancer calls derives from the epithelial-mesenchymal transition (EMT), a conserved cellular program that is crucial for embryonic development. Several studies have investigated the role of EMT in growth of early stage tumors into invasive malignancies. Also, EMT has been closely associated with the acquisition of chemoresistance properties in cancer cells. Motivated by these studies, we analyze multi-phenotype stochastic models of the evolution of cancers cell populations under stress. We derive analytical results for time-dependent probability distributions that provide insights into the competing rates underlying phenotypic switching (e.g. during EMT) and the corresponding survival of cancer cells. Experimentally, we evaluate these model-based predictions by imaging human pancreatic cancer cell lines grown with and without cytotoxic agents and measure growth kinetics, survival, morphological changes and (terminal evaluation of) biomarkers with associated epithelial and mesenchymal phenotypes. The results derived suggest approaches for distinguishing between adaptation and selection scenarios for survival in the presence of external stresses.

  7. Experimental study of interband and intraband crosstalk in WDM networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The impacts of interband and intraband crosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.

  8. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V

    1984-01-01

    Diffusion in Liquids: A Theoretical and Experimental Study aims to discuss the principles, applications, and advances in the field of diffusion, thermal diffusion, and thermal conduction in liquid systems. The book covers topics such as the principles of non-equilibrium thermodynamics; diffusion in binary and multicompetent systems; and experimental methods of studying diffusion processes in liquids. Also covered in the book are topics such as the theoretical interpretations of diffusion coefficients; hydrodynamic and kinetic theories; and diffusion in electrolyte systems. The text is recommen

  9. Analytical and Experimental Study of Residual Stresses in CFRP

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available Fiber Bragg Grating sensors (FBGs have been utilized in various engineering and photoelectric fields because of their good environment tolerance. In this research, residual stresses of carbon fiber reinforced polymer composites (CFRP were studied using both experimental and analytical approach. The FBGs were embedded inside middle layers of CFRP to study the formation of residual stress during curing process. Finite element analysis was performed using ABAQUS software to simulate the CFRP curing process. Both experimental and simulation results showed that the residual stress appeared during cooling process and the residual stresses could be released when the CFRP was machined to a different shape.

  10. 人胚胎干细胞来源的肝细胞小鼠移植的实验研究%An experimental study on human embryonic stem cell-derived hepatocytes transplantation into liver decompensated mice

    Institute of Scientific and Technical Information of China (English)

    梁道明; 张毅; 罗敏; 段永庆; 周粼; 王华

    2015-01-01

    Objective To study the ability of human embryonic stem cells to integrate into mouse liver and to repair chronic liver injury of the recipient.Methods On day 1,day-7 and day-15 after human embryonic stem cells were induced to differentiate into hepatocyte-like cells and were transplanted into mice with chronic liver failure,liver histopathology,liver function,liver tissue regeneration and mature hepatocytes of mice were tested respectively.Results Hepatic tissue pathology of mice significantly improved after transplantation and necrotic foci diminished,hemorrhage and congestion of hepatic cells relieved,and liver function improved.It was observed that human embryonic stem cells survived,proliferated,integrated with host liver,and differentiated into mature hepatocytes.Conclusions Human embryonic stem cells xenotransplanted into mice can participated liver tissue regeneration to some extent,and differentiated into functional liver cells.%目的 将人胚胎干细胞诱导分化成的肝细胞移植入小鼠模型,探讨其细胞整合到肝脏的能力,并观察对肝脏细胞损害的修复作用.方法 将人胚胎于细胞诱导分化成的肝样细胞移植入慢性肝功能衰竭小鼠体内l、7、15 d后,检测小鼠的肝脏病理组织学、肝功能以及分化肝细胞参与受体肝组织的再生及分化为成熟的肝细胞的情况.结果 移植后肝脏组织病理变化明显改善,表现为肝细胞以变性和炎性细胞浸润为主,坏死灶小、充血以及出血现象减轻;同时肝功能好转.分离到的人胚胎干细胞可在肝受损小鼠体内存活,增殖,整合,并能分化为成熟的肝细胞.结论 将人胚胎干细胞移植入小鼠体内后参与受体肝组织的再生,并能分化成功能性的肝细胞.

  11. Cinnamon extract suppresses experimental colitis through modulation of antigen-presenting cells

    Institute of Scientific and Technical Information of China (English)

    Ho-Keun Kwon; Zee Yong Park; Sin-Hyeog Im; Ji-Sun Hwang; Choong-Gu Lee; Jae-Seon So; Anupama Sahoo; Chang-Rok Im; Won Kyung Jeon; Byoung Seob Ko; Sung Haeng Lee

    2011-01-01

    AIM:To investigate the anti-inflammatory effects of cinnamon extract and elucidate its mechanisms for targeting the function of antigen presenting cells. METHODS:Cinnamon extract was used to treat murine macrophage cell line (Raw 264.7),mouse primary antigen-presenting cells (APCs,MHCII+) and CD11c+ dendritic cells to analyze the effects of cinnamon extract on APC function.The mechanisms of action of cinnamon extract on APCs were investigated by analyzing cytokine production,and expression of MHC antigens and co-stimulatory molecules by quantitative real-time PCR and flow cytometry.In addition,the effect of cinnamon extract on antigen presentation capacity and APC-dependent T-cell differentiation were analyzed by [H3]-thymidine incorporation and cytokine analysis,respectively. To confirm the anti-inflammatory effects of cinnamon extract in vivo ,cinnamon or PBS was orally administered to mice for 20 d followed by induction of experimental colitis with 2,4,6 trinitrobenzenesulfonic acid.The protective effects of cinnamon extract against experimental colitis were measured by checking clinical symptoms,histological analysis and cytokine expression profiles in inflamed tissue. RESULTS:Treatment with cinnamon extract inhibited maturation of MHCII+ APCs or CD11c+ dendritic cells (DCs) by suppressing expression of co-stimulatory molecules (B7.1,B7.2,ICOS-L),MHCII and cyclooxygenase (COX)-2.Cinnamon extract induced regulatory DCs (rDCs) that produce low levels of pro-inflammatory cytokines [interleukin (IL)-1β,IL-6,IL-12,interferon (IFN)-γ and tumor necrosis factor (TNF)-α] while expressing high levels of immunoregulatory cytokines (IL-10 and transforming growth factor-β).In addition, rDCs generated by cinnamon extract inhibited APC-dependent T-cell proliferation,and converted CD4+ T cells into IL-10high CD4+ T cells.Furthermore,oral administration of cinnamon extract inhibited development and progression of intestinal colitis by inhibiting expression of COX-2 and pro

  12. Theoretical and experimental investigation of 'grating' type photovoltaic cells

    Science.gov (United States)

    Loferski, J. J.; Crisman, E. E.; Armitage, W.; Chen, L. Y.

    1974-01-01

    The fabrication procedure and properties of 'grating' cells made by forming a fine grating pattern of aluminum alloyed into n-silicon wafers are described. The finest grating lines achieved in the cells described were 5 microns; the smallest spacing was about 15 microns. The best temperature for alloying was found to be about 600 C, a bit above the Si-Al eutectic temperature (576 C). The short-circuit current obtained from the best of these cells exposed to 100 mW/sq cm of (simulated air mass zero) illumination was at least equal to that obtained from conventional diffused cells, but their open-circuit voltage was lower. Their quantum yield was strongly blue-shifted; it was flat from 4000 to 8500 A.

  13. RC Columns Strengthened with Novel CFRP Systems: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Annalisa Napoli

    2015-10-01

    Full Text Available This paper presents an experimental study undertaken to investigate the seismic behavior of full scale square (300 mm × 300 mm reinforced concrete (RC columns strengthened with novel systems employing carbon fiber-reinforced polymers (CFRP wraps. Experimental tests were carried out by subjecting specimens to a constant axial load and a cyclically reversed horizontal force applied in displacement control. Results have allowed for investigating the influence of the used strengthening systems on the specimens’ performance in terms of flexural strength and ductility as well as on the exhibited failure modes. The effectiveness of the studied techniques is also evaluated by comparing the performance of tested specimens with that of companion columns strengthened with alternative CFRP systems investigated in a previous experimental campaign.

  14. Experimental studies of electron-phonon interactions in gallium nitride

    OpenAIRE

    Stanton, Nicola Marie

    2001-01-01

    This thesis presents an experimental investigation of the electron-phonon interaction in GaN. Bulk epilayers, grown by MBE, and AIGaN/GaN heterostructures, grown by MOCVD, have been studied. The energy relaxation rate for hot electrons has been measured over a wide range of temperatures, allowing both acoustic and optic phonon emission to be studied in GaN epilayers. Direct phonon measurements, both studying the emission and absorption processes, have been performed. Detection of phonons e...

  15. Computational and Experimental Study of an Industrial Centrifugal Compressor Volute

    Institute of Scientific and Technical Information of China (English)

    HarriPitkanen; HannuEsa; 等

    2000-01-01

    A centrifugal compressor with a vaneless diffuser was studied experimentally and numericallly.The main target of the study was to analyze the volute flow.Two different volute geometries was studied.The numerical solution was done by using a steady-state RANS code at both design and off-design conditions.Both calculated and measured pressure and velocity distributions are presented.

  16. Experimental study of bulk storage ignition by hot points

    OpenAIRE

    Janes, Agnès; Carson, Douglas

    2013-01-01

    International audience An experimental study of ignition risk due to hot points in the storage of bulk materials is required to ensure fire safety. Many parameters are involved in this phenomenon: nature of the material, storage volume and temperature, type and size of hot point, etc. The aim of this study is to determine critical ignition temperatures of hot spots embedded in powder materials for different conditions and with several types of hot points. Materials selected for this study ...

  17. An experimental study of the elastic theory for granular flows

    Science.gov (United States)

    Guo, Tongtong; Campbell, Charles S.

    2016-08-01

    This paper reports annular shear cell measurements granular flows with an eye towards experimentally confirming the flow regimes laid out in the elastic theory of granular flow. Tests were carried out on four different kinds of plastic spherical particles under both constant volume flows and constant applied stress flows. In particular, observations were made of the new regime in that model, the elastic-inertial regime, and the predicted transitions between the elastic-inertial and both the elastic-quasistatic and pure inertial regimes.

  18. Melanoma stem cells in experimental melanoma are killed by radioimmunotherapy

    International Nuclear Information System (INIS)

    Introduction: In spite of recently approved B-RAF inhibitors and immunomodulating antibodies, metastatic melanoma has poor prognosis and novel treatments are needed. Melanoma stem cells (MSC) have been implicated in the resistance of this tumor to chemotherapy. Recently we demonstrated in a Phase I clinical trial in patients with metastatic melanoma that radioimmunotherapy (RIT) with 188-Rhenium(188Re)-6D2 antibody to melanin was a safe and effective modality. Here we investigated the interaction of MSC with RIT as a possible mechanism for RIT efficacy. Methods: Mice bearing A2058 melanoma xenografts were treated with either 1.5 mCi 188Re-6D2 antibody, saline, unlabeled 6D2 antibody or 188Re-labeled non-specific IgM. Results: On Day 28 post-treatment the tumor size in the RIT group was 4-times less than in controls (P < 0.001). The tumors were analyzed by immunohistochemistry and FACS for two MSC markers — chemoresistance mediator ABCB5 and H3K4 demethylase JARID1B. There were no significant differences between RIT and control groups in percentage of ABCB5 or JARID1B-positive cells in the tumor population. Our results demonstrate that unlike chemotherapy, which kills tumor cells but leaves behind MSC leading to recurrence, RIT kills MSC at the same rate as the rest of tumor cells. Conclusions: These results have two main implications for melanoma treatment and possibly other cancers. First, the susceptibility of ABCB5 + and JARID1B + cells to RIT in melanoma might be indicative of their susceptibility to antibody-targeted radiation in other cancers where they are present as well. Second, specifically targeting cancer stem cells with radiolabeled antibodies to ABCB5 or JARID1B might help to completely eradicate cancer stem cells in various cancers

  19. Experimental study on adipose tissue engineering with human adipose-derived stem cells and adipose tissue extracellular matrix scaffold%人细胞外基质支架联合脂肪干细胞构建脂肪组织

    Institute of Scientific and Technical Information of China (English)

    察鹏飞; 高建华; 陈阳; 鲁峰

    2012-01-01

    目的 探讨人脂肪组织细胞外基质(ECM)支架联合人脂肪来源干细胞(ADSCs)构建工程化脂肪组织的可行性.方法 以酶消化法从人抽脂术抽吸物脂质部分获取人ADSCs,体外进行多向分化诱导鉴定,并行DiI荧光标记.从抽脂术的脂质部分分离提取人脂肪组织细胞外基质,经过低温冻干、粉碎、灭菌等处理,制备成粉末状,电镜扫描观察表面特征并将其与ADSCs进行黏附实验,探讨其作为支架材料的可行性.收集人ADSCs,以2×109/L的细胞密度与提取的细胞外基质支架复合后移植于裸鼠背部皮下,同鼠对侧背部皮下移植ECM支架和细胞培养液作为对照,每侧移植0.5 ml,共6只实验鼠.8周后取材,称量标本湿重.取出的标本行苏木素-伊红(HE)染色和油红O染色进行定性判断,分析人脂肪组织ECM支架联合人ADSCs构建工程化脂肪组织的能力.结果 从脂肪组织中分离得到人ADSCs和ECM支架.ADSCs在相应的诱导环境下能够分化成为脂肪细胞、骨细胞和软骨细胞.ECM支架电镜扫描和大体观察具有疏松、多孔的结构特征,适合ADSCs的黏附生长.ADSCs与支架相容性良好,黏附率达(89.87±2.59)%,细胞在支架表面可充分伸展生长.体内移植8周后,实验组和对照组都能够形成新生物,湿重比较实验组较对照组重(P<0.05).经HE切片及油红O染色均证实实验组形成成熟的脂肪组织,对照组不能形成脂肪组织.结论 人脂肪组织ECM支架联合人ADSCs在体内能够成功构建成熟的脂肪组织,8周后支架并无明显吸收.%Objective To explore the possibility of building tissue-engineered adipose tissue with human adipose-derived stem cells (ADSCs) and adipose tissue extracellular matrix (ECM) scaffold,and provide experimental basis for clinical application of tissue-engineered adipose tissue for the repair of soft tissue defects.Methods ADSCs were isolated from adipose tissue by liposuction with the

  20. Experimental Study on a Rotor for WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study of the power conversion capabilities of one single rotor of the WEPTOS wave energy converter. The investigation focuses mainly on defining the optimal weight distribution in the rotor in order to improve the hydraulic performance through...

  1. Experimental study of the breakdown phase in coaxial plasma guns

    International Nuclear Information System (INIS)

    The problem of the dielectric breakdown of gases and its relevance in plasma devices is discussed, and preliminary results of an experimental study upon the spatial location and time evolution of the breakdown phase in a plasma focus device are given

  2. SMS as a Learning Tool: An Experimental Study

    Science.gov (United States)

    Plana, Mar Gutiérrez-Colon; Torrano, Pere Gallardo; Grova, M. Elisa

    2012-01-01

    The aim of this experimental study was to find out the potential of using mobile phones in teaching English as a foreign language (EFL), specifically the use of Short Message Service (SMS) as a support tool in the EFL class. The research questions formulated for this project are the following: (1) Is using SMS messages via a mobile phone an…

  3. MODEL METHODS FOR THE ANALYSIS OF MESOCOSM EXPERIMENTAL STUDIES

    NARCIS (Netherlands)

    BRINKMAN, AG; PHILIPPART, CJM; ZUUR, AF

    1995-01-01

    The response of experimental ecosystem dynamics to varying nutrient loads was studied by analysing oxygen time-series. Time-series had been continuously recorded, and the data were analysed on a daily basis using a computer model which describes basic oxygen processes. The resulting sets of producti

  4. Real versus Simulated Mobile Phone Exposures in Experimental Studies

    Directory of Open Access Journals (Sweden)

    Dimitris J. Panagopoulos

    2015-01-01

    Full Text Available We examined whether exposures to mobile phone radiation in biological/clinical experiments should be performed with real-life Electromagnetic Fields (EMFs emitted by commercially available mobile phone handsets, instead of simulated EMFs emitted by generators or test phones. Real mobile phone emissions are constantly and unpredictably varying and thus are very different from simulated emissions which employ fixed parameters and no variability. This variability is an important parameter that makes real emissions more bioactive. Living organisms seem to have decreased defense against environmental stressors of high variability. While experimental studies employing simulated EMF-emissions present a strong inconsistency among their results with less than 50% of them reporting effects, studies employing real mobile phone exposures demonstrate an almost 100% consistency in showing adverse effects. This consistency is in agreement with studies showing association with brain tumors, symptoms of unwellness, and declines in animal populations. Average dosimetry in studies with real emissions can be reliable with increased number of field measurements, and variation in experimental outcomes due to exposure variability becomes less significant with increased number of experimental replications. We conclude that, in order for experimental findings to reflect reality, it is crucially important that exposures be performed by commercially available mobile phone handsets.

  5. Can Facebook Make Students Remember? An Experimental Study from Japan

    Science.gov (United States)

    Acar, Adam

    2014-01-01

    This study experimentally manipulated the way students submit their assignments and tested the number of new words that are learned in each condition. The results showed that students who submitted their assignments through Facebook learned as much as those who submitted their assignment in a traditional way. In the light of these findings, we can…

  6. Theoretical and experimental studies of a plasma- and particle accelerator

    International Nuclear Information System (INIS)

    Using the combination of a coaxial plasma accelerator with a compression coil a dense and fast plasma flow can be produced and applied for gas-dynamical acceleration of particles. The theoretical and experimental studies presented here contribute to a better understanding of the acceleration process and to the operational application of the system as a micrometeor simulator. (orig.)

  7. Chemometric Optimization Studies in Catalysis Employing High-Throughput Experimentation

    NARCIS (Netherlands)

    Pereira, S.R.M.

    2008-01-01

    The main topic of this thesis is the investigation of the synergies between High-Throughput Experimentation (HTE) and Chemometric Optimization methodologies in Catalysis research and of the use of such methodologies to maximize the advantages of using HTE methods. Several case studies were analysed

  8. Theoretical and Experimental Study of Time Reversal in Cubic Crystals

    Institute of Scientific and Technical Information of China (English)

    陆铭慧; 张碧星; 汪承灏

    2004-01-01

    The self-adaptive focusing of the time reversal in anisotropic media is studied theoretically and experimentally. It is conducted for the compressional wave field in the cubic crystal silicon. The experimental result is in agreement with our theoretical analysis. The focusing gain and the displacement distributions of the time reversal field are analysed in detail. It is shown that the waves from different elements of the transducer array arrive at the original place of the source simultaneously after the time reversal operation. The waveform distortions caused by the velocity anisotropy can automatically be compensated for after the time reversal processing.

  9. Single-Molecule Studies in Live Cells

    Science.gov (United States)

    Yu, Ji

    2016-05-01

    Live-cell single-molecule experiments are now widely used to study complex biological processes such as signal transduction, self-assembly, active trafficking, and gene regulation. These experiments' increased popularity results in part from rapid methodological developments that have significantly lowered the technical barriers to performing them. Another important advance is the development of novel statistical algorithms, which, by modeling the stochastic behaviors of single molecules, can be used to extract systemic parameters describing the in vivo biochemistry or super-resolution localization of biological molecules within their physiological environment. This review discusses recent advances in experimental and computational strategies for live-cell single-molecule studies, as well as a selected subset of biological studies that have utilized these new technologies.

  10. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  11. Experimental study of affinity of endothelial outgrowth cells cultured on aligned plla nanofibrous scaffolds%纳米化左旋聚乳酸有序膜的细胞亲和性研究

    Institute of Scientific and Technical Information of China (English)

    卢辉俊; 冯章启; 顾忠泽; 刘长建

    2009-01-01

    目的 制备具有较好细胞亲和性、利于内皮生长晕细胞(EOCs))黏附增殖的纳米左旋聚乳酸有序膜,为构建组织工程血管材料提供理论依据.方法 改性后纳米纤维膜与细胞复合培养,观察细胞与材料牛物亲和性.结果 纳米纤维孔径在300~400 nm,孔隙率>90%.有序和超级有序膜组吸光度,4值与无序膜、单纯细胞组差异有显著统计学意义(P<0.05).无序膜细胞生长较散在、杂乱;有序及超级有序纤维膜有利于细胞沿纤维定向附着、增殖.结论 EOCs是理想的组织工程血管种子细胞来源.有序及超级有序膜是一种理想的组织工程血管材料.%Objective Tissue engineering holds great promise in providing vascular grafts as substitutes for damaged small-di-ameter blood vessels. Two of the key factors in vascular tissue engineering are biocompatible scaffolds that mimic the effects of extra-cellular matrix and the source of seeding cells. To study the cellular affinity and adhesion and proliferation of endothelial outgrowth cells (EOCs) obtained from rabbit peripheral blood cultured with the aligned synthetic poly-L-lactic acid(PLLA) nanofibers in vitro so as to provide a solid foundation for future vascular tissue engineering involving both PLLA and EOCs. Methods The random, aligned and super-aligned PLLA nanofibers were prepared by an insulated high-speed roller collector covered with parallel steel sticks rotating at 0 rpm, 1000 rpm and 2500 rpm, respectively. Finally, the electorspun PLLA nanofibers were modified by hypothermy plasma and type Ⅰ collagen was coated onto the materials physically. The resulting rabbit peripheral blood mononuclear cell (PBMC) were collect-ed and resuspended in endothelial basal medium (EBM-2) supplemented with EBM-2-SingleQuots, which were continually cultured with complete EBM-2 medium for 3 weeks. To confirm EOC generation during culturing, morphological changes of adherent cells were visualized with Olympus

  12. Experimental and numerical study of open-air active cooling

    Science.gov (United States)

    Al-Fifi, Salman Amsari

    The topic of my thesis is Experimental and Numerical Study of Open Air Active Cooling. The present research is intended to investigate experimentally and Numerically the effectiveness of cooling large open areas like stadiums, shopping malls, national gardens, amusement parks, zoos, transportation facilities and government facilities or even in buildings outdoor gardens and patios. Our cooling systems are simple cooling fans with different diameters and a mist system. This type of cooling systems has been chosen among the others to guarantee less energy consumption, which will make it the most favorable and applicable for cooling such places mentioned above. In the experiments, the main focus is to study the temperature domain as a function of different fan diameters aerodynamically similar in different heights till we come up with an empirical relationship that can determine the temperature domain for different fan diameters and for different heights of these fans. The experimental part has two stages. The first stage is devoted to investigate the maximum range of airspeed and profile for three different fan diameters and for different heights without mist, while the second stage is devoted to investigate the maximum range of temperature and profile for the three different diameter fans and for different heights with mist. The computational study is devoted to built an experimentally verified mathematical model to be used in the design and optimization of water mist cooling systems, and to compare the mathematical results to the experimental results and to get an insight of how to apply such evaporative mist cooling for different places for different conditions. In this study, numerical solution is presented based on experimental conditions, such dry bulb temperature, wet bulb temperature, relative humidity, operating pressure and fan airspeed. In the computational study, all experimental conditions are kept the same for the three fans except the fan airspeed

  13. An experimental and numerical study of water jet cleaning process

    CERN Document Server

    Guha, Anirban; Balachandar, Ram

    2010-01-01

    In this paper, we have experimentally, numerically and theoretically investigated the water jet cleaning process. Very high speed water jets (~80-200 m/s) are used in such cleaning operations. These jets diffuse in the surrounding atmosphere by the process of air entrainment and this contributes to the spreading of the jet and subsequent decay of pressure. Estimation of this pressure decay and subsequent placement of the cleaning object is of paramount importance in manufacturing and material processing industries. Also, the pressure distribution on the cleaning surface needs to be assessed in order to understand and optimize the material removal process. Experimental study is performed to understand the pressure characteristics. A Semi-empirical model for capturing the air entrainment has been added to the commercial CFD package FLUENT. The simulation results are validated against ours as well as previous experimental findings. The numerical results have shown that the optimal stand-off distance in cleaning ...

  14. Mechanical properties of jennite: A theoretical and experimental study

    International Nuclear Information System (INIS)

    The objective of this study is to determine the mechanical properties of jennite. To date, several hypotheses have been proposed to predict the structural properties of jennite. For the first time as reported herein, the isothermal bulk modulus of jennite was measured experimentally. Synchrotron-based high-pressure x-ray diffraction experiments were performed to observe the variation of lattice parameters under pressure. First-principles calculations were applied to compare with the experimental results and predict additional structural properties. Accurately measured isothermal bulk modulus herein (K0 = 64(2) GPa) and the statistical assessment on experimental and theoretical results suggest reliable mechanical properties of shear and Young's modulus, Poisson's ratio, and elastic tensor coefficients. Determination of these fundamental structural properties is the first step toward greater understanding of calcium–silicate–hydrate, as well as provides a sound foundation for forthcoming atomic level simulations

  15. Mechanical properties of jennite: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Juhyuk, E-mail: juhyuk.moon@stonybrook.edu [Civil Engineering Program, Department of Mechanical Engineering, Stony Brook University, NY 11794 (United States); Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Monteiro, Paulo J.M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-05-15

    The objective of this study is to determine the mechanical properties of jennite. To date, several hypotheses have been proposed to predict the structural properties of jennite. For the first time as reported herein, the isothermal bulk modulus of jennite was measured experimentally. Synchrotron-based high-pressure x-ray diffraction experiments were performed to observe the variation of lattice parameters under pressure. First-principles calculations were applied to compare with the experimental results and predict additional structural properties. Accurately measured isothermal bulk modulus herein (K{sub 0} = 64(2) GPa) and the statistical assessment on experimental and theoretical results suggest reliable mechanical properties of shear and Young's modulus, Poisson's ratio, and elastic tensor coefficients. Determination of these fundamental structural properties is the first step toward greater understanding of calcium–silicate–hydrate, as well as provides a sound foundation for forthcoming atomic level simulations.

  16. Experimental study on CHF enhancement of plate by ultrasonic

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Hun; Kweon, Young Chel [Sunmoon Univ., Asan (Korea, Republic of); Jeong, Ji Hwan [Chonan College of Foreign Studies, Chonan (Korea, Republic of)

    2003-07-01

    Augmentation of CHF by ultrasonic is experimentally studied under subcooling pool boiling condition. Experiment is carried out for downward-facing plate with and without the ultrasonic. The working fluid is distilled water. Experimental apparatus is composed of a bath, power supply, test section, ultrasonic generator, DAQ system. Experiment is performed with the subcooling temperature of 5 .deg. C, 20 .deg. C, 40 .deg. C and the inclined angle of 0 .deg., 10 .deg., 20 .deg., 45 .deg., 90 .deg.. From the experimental results, it is found that ultrasonic effect enhances CHF of the downward-facing plate. As increasing the degree of subcooling, the rate of CHF increase is enhanced. As increasing the inclined angle, the rate of CHF increase decreases. Also, we can see that the heat transfer mechanism of CHF augmentation is closely connected with the dynamic behavior of bubble generation and departure.

  17. Experimental models used for the study of antihepatotoxic agents

    Institute of Scientific and Technical Information of China (English)

    Feroz Ahmad; Nahida Tabassum

    2012-01-01

    Both in vitro and in vivo liver models have been developed in the past years to study the hepatoprotective agents. These systems measure the ability of the test drug to prevent or cure liver toxicity (induced by various hepatotoxins) in experimental animals. In in vitro models fresh hepatocytes are treated with hepatotoxin and the effect of the test drug on the same is evaluated. In in vivo models, a toxic dose or repeated doses of a known hepatotoxin are administered to induce liver damage in experimental animals. The test substance is administered along with, prior to and/or after the toxin treatment. Various chemical agents normally used to induce hepatotoxicty in experimental animals for the evaluation of hepatoprotective agents include carbon tetrachloride, paracetamol, Acrylamide, adriamycin, alcohol, antitubercular drugs etc. The present article explains the mechanism of action of various hepatotoxic chemical/drugs, their dosage and route of administration.

  18. 二甲双胍抗肿瘤血管及抑制胃癌细胞生长的实验研究%Experimental study of Metformin for inhibiting tumor angiogenesis and gastric cancer cell growth

    Institute of Scientific and Technical Information of China (English)

    童陈琦; 王维; 梁斌鑫

    2015-01-01

    目的:探讨二甲双胍对肿瘤血管及胃癌细胞生长的抑制作用。方法利用人脐静脉血管内皮细胞(HU-VEC)细胞划痕试验、Transwell侵袭实验、Matrigel血管状结构形成实验,研究二甲双胍对血管内皮细胞侵袭、迁移及血管状结构形成的影响,且运用流式细胞仪检测二甲双胍对血管内皮生长因子(VEGF)表达的影响;利用胃癌细胞BGC823的MTT实验、苏木精凋亡染色、Annexin-吁细胞凋亡实验、定量PCR凋亡因子检测实验,研究二甲双胍对胃癌细胞增殖、凋亡的影响。结果二甲双胍能够明显抑制HUVEC的迁移、侵袭、血管状结构形成,并且明显减少细胞VEGF的表达;二甲双胍对胃癌BGC823细胞的增殖有明显的抑制作用,且具有浓度依赖性,其中最大抑制率为68.80%,半抑制浓度(IC50)为(11.97±1.84)mmol/L;二甲双胍可以诱导胃癌BGC823细胞凋亡,具有浓度依赖性,10 mmol/L二甲双胍组凋亡比例接近60%;二甲双胍组BGC823细胞的Bcl-2 mRNA减少,而AMP-Kα1、Bax、Bad mRNA的表达增加。结论二甲双胍能够抑制肿瘤血管形成和胃癌细胞增殖,并诱导胃癌细胞凋亡,发挥抗胃癌细胞生长作用。%Objective To investigate the inhibiting effect of Metformin on the tumor angiogenesis and gastric cancer cell growth. Methods The cell scratch test, Transwell invasion assay and Matrigel vascular structure formation experi-ment of human umbilical vein endothelial cells (HUVEC) were used to study the effect of Metformin on vascular en-dothelial cell migration, invasion and the vascular structure formation, and the influence of Metformin on VEGF ex-pression was illuminated by flow cytometry; then MTT assay, hematoxylin apoptosis of dyeing, Annexin-Ⅴ apoptosis and quantitative PCR detection for apoptosis factors of gastric cancer BGC823 cells were conducted to research the ef-fect of Metformin on gastric cancer cell proliferation and apoptosis

  19. Experimental study of curved guide tubes for pellet injection

    International Nuclear Information System (INIS)

    The use of curved guide tubes for transporting frozen hydrogen pellets offers great flexibility for pellet injection into plasma devices. While this technique has been previously employed, an increased interest in its applicability has been generated with the recent ASDEX Upgrade experimental data for magnetic high-field side (HFS) pellet injection. In these innovative experiments, the pellet penetration appeared to be significantly deeper than for the standard magnetic low-field side injection scheme, along with corresponding greater fueling efficiencies. Thus, some of the major experimental fusion devices are planning experiments with HFS pellet injection. Because of the complex geometries of experimental fusion devices, installations with multiple curved guide tube sections will be required for HFS pellet injection. To more thoroughly understand and document the capability of curved guide tubes, an experimental study is under way at the Oak Ridge National Laboratory (ORNL). In particular, configurations and pellet parameters applicable for the DIII-D tokamak and the International Thermonuclear Experimental Reactor (ITER) were simulated in laboratory experiments. Initial test results with nominal 2.7- and 10-mm-diam deuterium pellets are presented and discussed

  20. Cell cycle regulation and apoptotic cell death in experimental colon carcinogenesis: intervening with cyclooxygenase-2 inhibitors.

    Science.gov (United States)

    Saini, Manpreet Kaur; Sanyal, Sankar Nath

    2015-01-01

    Relative imbalance in the pathways regulating cell cycle, cell proliferation, or cell death marks a prerequisite for neoplasm. C-phycocyanin, a biliprotein from Spirulina platensis and a selective COX-2 inhibitor along with piroxicam, a traditional nonsteroidal antiinflammatory drug was used to investigate the role of cell cycle regulatory proteins and proinflammatory transcription factor NFκB in 1,2-dimethylhydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis. Cell cycle regulators [cyclin D1, cyclin E, cyclin dependent kinase 2 (CDK2), CDK4, and p53], NFκB (p65) pathway, and proliferating cell nuclear antigen (PCNA) were evaluated by gene and protein expression, whereas apoptosis was studied by terminal deoxynucleotidyl transferase dUTP nick end labeling and apoptotic bleb assay. Molecular docking of ligand protein interaction was done to validate the in vivo results. Cyclin D1, cyclin E, CDK2, and CDK4 were overexpressed in DMH, whereas piroxicam and c-phycocyanin promoted the cell cycle arrest by downregulating them. Both drugs mediated apoptosis through p53 activation. Piroxicam and c-phycocyanin also stimulated antiproliferation by restraining PCNA expression and reduced cell survival via inhibiting NFκB (p65) pathway. Molecular docking revealed that phycocyanobilin (a chromophore of c-phycocyanin) interact with DNA binding site of NFκB. Inhibition of cyclin/CDK complex by piroxicam and c-phycocyanin affects the expression of p53 in colon cancer followed by downregulation of NFκB and PCNA levels, thus substantiating the antineoplastic role of these agents. PMID:25825916

  1. A Combined Molecular Dynamics and Experimental Study of Doped Polypyrrole

    OpenAIRE

    Fonner, John M.; Schmidt, Christine E; Ren, Pengyu

    2010-01-01

    Polypyrrole (PPy) is a biocompatible, electrically conductive polymer that has great potential for battery, sensor, and neural implant applications. Its amorphous structure and insolubility, however, limit the experimental techniques available to study its structure and properties at the atomic level. Previous theoretical studies of PPy in bulk are also scarce. Using ab initio calculations, we have constructed a molecular mechanics force field of chloride-doped PPy (PPyCl) and undoped PPy. Th...

  2. Experimental Studies of Cold Roll Bonded Aluminum Alloys

    OpenAIRE

    Lauvdal, Steinar

    2011-01-01

    This master’s thesis is based on experimental studies of the parameters influencing cold roll bonding (CRB) of the aluminum alloys AA1200 and AA3103,in the work hardened and annealed condition. The effect on the bond strength from the preparations parameters as degreasing agent, scratch brushing and exposure time for oxide growth is investigated in comparison to former studies. Further the effect of rolling speed and effect from contributing factors from the different testing methods is ...

  3. An Experimental Study on Hypothyroid Using Rotation Forest

    OpenAIRE

    Sheetal Gaikwad; Nitin Pise

    2014-01-01

    This paper majorly focuses on hypothyroid medical diseases caused by underactive thyroid glands. The dataset used for the study on hypothyroid is taken from UCI repository. Classification of this thyroid disease is a considerable task. An experimental study is carried out using rotation forest using features selection methods to achieve better accuracy. An important step to gain good accuracy is a pre- processing step, thus here two feature selection techniques are used. A filter method, Corr...

  4. Design and experimental studies of a novel circularly polarized antenna

    OpenAIRE

    Zhang Hai; Zhang Wei Guo; Ge Yue He

    2016-01-01

    A circularly polarized antenna with patches on the top is studied in this paper. The antenna is composed of two printed dipoles and four radiation patches which are loaded on top of the dipoles. The antenna is fed by microstrip balum in the middle of dielectric slab. And the balum is connected to a Wilkinson power divider which owns 90 degree phase shift. Numerical simulations of proposed antenna are performed using the 3D electromagnetic simulation software HFSS. The experimental studies of ...

  5. Vortex formation behind movable leaflet: experimental and numerical studies

    OpenAIRE

    Vukicevic, Marija

    2011-01-01

    Fluid structure interaction (FSI) is one of fundamental phenomena encountered everywhere in nature or in industrial systems as well as one of the most studied and the most challenging topics in the fluid mechanics. Its research presents the core objective of this dissertation, along with experimental study of artificial heart devices. Better understanding of FSI could turn the still unexploited phenomenon into a powerful tool for resolving wealthy of multi-physics problems. Recently computati...

  6. Experimental Studies on Thermal and Electrical Properties of Platinum Nanofilms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xing; ZHANG Qing-Guang; CAO Bing-Yang; FUJII Motoo; TAKAHASHI Koji; IKUTA Tatsuya

    2006-01-01

    @@ We experimentally studied the in-plane thermal and electrical properties of a suspended platinum nanofilm in thickness of 15 nm. The measured results show that the in-plane thermal conductivity, the electrical conductivity and the resistance-temperature coefficient of the studied nanofilm are much less than those of the bulk material,while the Lorenz number is greater than the bulk value.

  7. 骨髓间充质干细胞移植治疗脑出血大鼠的实验研究%Experimental study of bone mesenchymal stem cells transplantation for intracerebral hemorrhage in rats

    Institute of Scientific and Technical Information of China (English)

    徐德才; 张少军; 娄飞云; 姜之全; 韩易

    2014-01-01

    目的:探讨骨髓间充质干细胞移植对脑出血大鼠的行为和血肿周围神经细胞凋亡的影响。方法全骨髓贴壁法分离培养大鼠骨髓间充质干细胞,使用立体定向纹状体注入胶原酶法制作大鼠脑出血模型。 SD大鼠30只,随机分为对照组和移植组(各15只),对照组制作脑出血模型,不移植;移植组制作脑出血模型并于造模后48h经立体定向脑内注射1×105个干细胞,并于移植后1d、3d、5d、7d、14d进行神经功能缺损评分,对照组在相应时间点同样评分,各组再根据时间的不同随机分成五个亚组(每组3只),在相应时间点处死大鼠行免疫组织化学法检测细胞凋亡。结果在移植后1 d、3 d,两组大鼠评分及血肿周围脑组织内凋亡细胞的数量均较高,两组之间无显著性差异。在移植后第5 d、7 d,两组大鼠评分及血肿周围脑组织内凋亡细胞的数量开始下降,移植组下降幅度大于对照组,两组之间差异显著。移植后14 d,两组之间无显著性差异。结论骨髓间充质干细胞移植可明显促进大鼠脑出血后神经功能的恢复,其机制可能与下调血肿周围神经细胞凋亡有关。%Objective To explore the effect of the behavioral test and neurological cell apoptosis on transplantation of bone mesenchymal stem cells (BMSCs) for experimental intracerebral hemorrhage (ICH) in rats.Methods BMSCs were isolated and cultured using the whole bone marrow adherent method.A rat model of ICH was established by stereotaxical injection of collagenase Ⅰinto the right caudate nucleus .30 Sprague-Dawley ( SD ) rats were randomly divided into control group ( 15 ) and transplantation group (15).The control group were injected with collagenaseⅠonly,the transplant-ation group were transfused with BMSCs (1 ×105/rat) at 48 hours after surgery .On 1,3,5,7,14 days afer transplantation neurological function tests were performed among

  8. STUDY OF CNS EFFECTS OF MACROLIDE ANTIBIOTICS: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Deshmukh

    2013-02-01

    Full Text Available ABSTRACT: Macrolides are an old, well established class of an tibacterial agents which play an important role in the management of infectious dise ases. The present study was undertaken to study the CNS effects of some of the macrolides ant ibiotics namely erythromycin, clarithromycin, azithromycin and roxithromycin in r ats. 30 healthy adult albino rats of either sex of Haffkine’s strain weighing 100-200g were use d for the study. Each group consists of six animals. Various tests were used for screening of drugs on CNS activity. Amongst the macrolides namely erythromycin claritromycin, azith romycin and roxithromycin, only roxithromycin showed CNS depressant activity in rat s. Similarly only roxithromycin and azithromycin showed anti-inflammatory property.

  9. Diversification and senescence of Foxp3+ regulatory T cells during experimental autoimmune encephalomyelitis

    OpenAIRE

    Tauro, Sharyn; Nguyen, Phuong; Li, Bofeng; Geiger, Terrence L.

    2013-01-01

    The fate of Foxp3+ regulatory T cells (Treg) responding during autoimmunity is not well defined. We observed a marked elevation in KLRG1+ CNS-infiltrating Treg in experimental autoimmune encephalomyelitis (EAE), and assessed their origin and properties. KLRG1+ Treg showed increased activation marker expression, Foxp3 and CD25 levels, and more rapid cell cycling than KLRG1− cells. KLRG1− Treg converted into KLRG1+ cells and this was increased in the context of autoimmune inflammation. Conversi...

  10. Secretome Analysis of Lipid-Induced Insulin Resistance in Skeletal Muscle Cells by a Combined Experimental and Bioinformatics Workflow

    DEFF Research Database (Denmark)

    Deshmukh, Atul S; Cox, Juergen; Jensen, Lars Juhl;

    2015-01-01

    , in principle, allows an unbiased and comprehensive analysis of cellular secretomes; however, the distinction of bona fide secreted proteins from proteins released upon lysis of a small fraction of dying cells remains challenging. Here we applied highly sensitive MS and streamlined bioinformatics to analyze......-resistant conditions. Our study demonstrates an efficient combined experimental and bioinformatics workflow to identify putative secreted proteins from insulin-resistant skeletal muscle cells, which could easily be adapted to other cellular models....

  11. Experimental model for collagen estimation in cell culture Modelo experimental para avaliação do colágeno em cultura de células

    Directory of Open Access Journals (Sweden)

    Sidney Mamoru Keira

    2004-12-01

    Full Text Available In the study of Plastic Surgery, cell culture may be used at experimental level in researches concerning biosynthesis functions of skin cells such as fibroblasts, keratinocytes, adipocytes, chondrocytes and osteocytes. The present study reports an experimental model for estimation of collagen in cell cultures using chromogenic precipitation reaction with an especific dye (Sirius Red.Dentro do estudo da Cirurgia Plástica, a cultura de células pode ser utilizada em experimentos relativos às funções de biossíntese de células relacionadas com a pele tais como fibroblastos, queratinócitos, adipócitos, condrócitos e osteócitos. O presente estudo relata modelo experimental para a mensuração estimada do colágeno em cultura de células utilizando-se uma reação de precipitação cromogênica com um corante específico (Sirius Red.

  12. Epidermal cell proliferation in guinea pigs with experimental dermatophytosis

    International Nuclear Information System (INIS)

    To elucidate the mechanisms underlying the self-healing process of experimental dermatophytosis produced in guinea pigs by an occlusive method with Trichophyton mentagrophytes, epidermal proliferative activity was evaluated by the in vivo tritiated thymidine-labeling technique performed at various intervals after the first and second infections. Determination of labeling indices disclosed that an increased epidermal proliferation correlated well with the severity of inflammatory changes, i.e., a peak activity was noted after 10 days in primary infection and at 2 days in reinfection, respectively, and was followed by subsequent spontaneous lesion clearance after 10 days. Application of a heat-killed spore suspension produced inflammatory changes with enhanced epidermopoiesis, similar to those induced by reinoculation of living spores, only in immune animals. The present results indicate that the dermatitic changes occurring in experimental dermatophytosis increase epidermopoiesis which facilitates elimination of the fungus from the stratum corneum and that host immune activity, particularly contact sensitivity to fungal antigen, exerts a crucial role to induce these changes

  13. Salmon cartilage proteoglycan suppresses mouse experimental colitis through induction of Foxp3{sup +} regulatory T cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, Toshihito [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan); Department of Digestive Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Sashinami, Hiroshi [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan); Sato, Fuyuki; Kijima, Hiroshi [Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Ishiguro, Yoh; Fukuda, Shinsaku [Department of Digestive Internal Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Yoshihara, Shuichi [Department of Glycomedicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Hakamada, Ken-Ichi [Department of Digestive Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562 (Japan); Nakane, Akio, E-mail: a27k03n0@cc.hirosaki-u.ac.jp [Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562 (Japan)

    2010-11-12

    Research highlights: {yields} Salmon proteoglycan suppresses IL-10{sup -/-} cell transfer-induced colitis progression. {yields} Salmon proteoglycan suppresses Th1- and Th17-related factors in colitis mice. {yields} Salmon proteoglycan enhances Foxp3 expression. -- Abstract: Proteoglycans (PGs) are complex glycohydrates which are widely distributed in extracellular matrix (ECM). PGs are involved in the construction of ECM, cell proliferation and differentiation. ECM components are involved in transduction of proinflammatory responses, but it is still unknown whether PGs are involved in inflammatory response. In this study, we investigated the effect of PG extracted from salmon cartilage on the progression of experimental colitis-induced in severe combined immunodeficiency mice by cell transfer from interleukin-10 (IL-10){sup -/-} mice. IL-10{sup -/-} cell-transferred mice showed weight loss, colon shortening and histological appearance of mild colitis. Daily oral administration of PG attenuated the clinical progression of colitis in a dose-dependent manner. Colitis-induced mice showed the elevated expression of IFN-{gamma}, IL-12, TNF-{alpha}, IL-21, IL-23p19, IL-6, IL-17A and retinoic acid-related orphan receptor {gamma}t (ROR{gamma}t) in lamina propria mononuclear cells (LPMCs) and oral administration of PG suppressed the expression of these factors. Conversely, expression of Foxp3 that induces CD4{sup +}CD25{sup +} regulatory T cells in LPMCs was enhanced by PG administration. These findings suggested that salmon PG attenuated the progression of colitis due to suppression of inflammatory response by enhancement of regulatory T cell induction.

  14. Experimental and Theoretical Study on Pyrolysis of Isopsoralen

    Institute of Scientific and Technical Information of China (English)

    Jiu-zhong Yang; Feng Zhang; Liang-yuan Jia; Li-dong Zhang; Fei Qi; Hai-yan Fan; Ji-bao Cai

    2012-01-01

    The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure.The pyrolysis products were detected at different photon energies,the ratios of products to precursor were measured at various pyrolysis temperatures.The experimental results demonstrate that the main pyrolysis products are primary CO and sequential CO elimination products (C10H6O2 and C9H6O).The decomposition channels of isopsoralen were also studied by the density functional theory,then rate constants for competing pathways were calculated by the transition state theory.The dominant decomposition channels of isopsoralen and the molecular structures for corresponding products were identified bv combined experimental and theoretical studies.

  15. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  16. Pancreatic acinar cells-derived cyclophilin A promotes pancreatic damage by activating NF-κB pathway in experimental pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ge [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Wan, Rong [Department of Gastroenterology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Hu, Yanling [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Ni, Jianbo [Department of Gastroenterology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Yin, Guojian; Xing, Miao [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Shen, Jie [Department of Gastroenterology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Tang, Maochun [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Chen, Congying [Department of Gastroenterology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Fan, Yuting; Xiao, Wenqin; Zhao, Yan [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Wang, Xingpeng, E-mail: wangxingpeng@hotmail.com [Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai (China); Department of Gastroenterology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); and others

    2014-01-31

    Highlights: • CypA is upregulated in experimental pancreatitis. • CCK induces expression and release of CypA in acinar cell in vitro. • rCypA aggravates CCK-induced acinar cell death and inflammatory cytokine production. • rCypA activates the NF-κB pathway in acinar cells in vitro. - Abstract: Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway.

  17. Pancreatic acinar cells-derived cyclophilin A promotes pancreatic damage by activating NF-κB pathway in experimental pancreatitis

    International Nuclear Information System (INIS)

    Highlights: • CypA is upregulated in experimental pancreatitis. • CCK induces expression and release of CypA in acinar cell in vitro. • rCypA aggravates CCK-induced acinar cell death and inflammatory cytokine production. • rCypA activates the NF-κB pathway in acinar cells in vitro. - Abstract: Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway

  18. Modulation of experimental T cell autoimmunity in the nervous system with emphasis on nasal tolerance

    OpenAIRE

    Bai, Xue-Feng

    1998-01-01

    MODULATION OF EXPERIMENTAL T CELL AUTOIMMUNITY IN THE NERVOUSSYSTEM WITH EMPHASIS ON NASAL TOLERANCE Xue-Feng Bai Doctoral thesis from Division of Neurology, Department of ClinicalNeuroscience and Family Medicine, Karolinska Institute, Huddinge University Hospital,Stockholm, Sweden Experimental autoimmune neuritis (EAN) and encephalomyelitis (EAE) are animalmodels of Guillian-Barre syndrome (GBS) and multiple sclerosis (MS), representinghuman demyelinating diseases ...

  19. Experimental study of elementary collection efficiency of aerosols by spray: Design of the experimental device

    Energy Technology Data Exchange (ETDEWEB)

    Ducret, D.; Vendel, J.; Garrec. S.L.

    1995-02-01

    The safety of a nuclear power plant containment building, in which pressure and temperature could increase because of a overheating reactor accident, can be achieved by spraying water drops. The spray reduces the pressure and the temperature levels by condensation of steam on cold water drops. The more stringent thermodynamic conditions are a pressure of 5.10{sup 5} Pa (due to steam emission) and a temperature of 413 K. Moreover its energy dissipation function, the spray leads to the washout of fission product particles emitted in the reactor building atmosphere. The present study includes a large program devoted to the evaluation of realistic washout rates. The aim of this work is to develop experiments in order to determine the collection efficiency of aerosols by a single drop. To do this, the experimental device has to be designed with fundamental criteria:-Thermodynamic conditions have to be representative of post-accident atmosphere. Thermodynamic equilibrium has to be attained between the water drops and the gaseous phase. Thermophoretic, diffusiophoretic and mechanical effects have to be studied independently. Operating conditions have to be homogenous and constant during each experiment. This paper presents the design of the experimental device. In practice, the consequences on the design of each of the criteria given previously and the necessity of being representative of the real conditions will be described.

  20. Dependence of radiation effects in the progeny of the fist and second generation on stages of the development of germ cell of both parents at the time of irradiation: Experimental studies

    International Nuclear Information System (INIS)

    Studies of 35199 offspring of Wistar rats showed that after irradiation of both parents (P) with doses of 0.25-4 Gy the manifestation of radiation effects in the descendants of the first (F1) and second (F2) generations in ontogenesis depended upon radiation dose and the stage of development of P germ cells at the moment of radiation exposure. After irradiation of the matured oocytes, spermatidis and spermatozoids the consequences for FI are mainly determined by a female or their aggravation takes place. After irradiation of the maturing oocytes, spermatocytes and spermatogonia the effects for F1 are mainly determined by the male. The death of F1 occurs chiefly in embryogenesis and F2 in early postnatal ontogenesis. It is more marked by the father's line (the descendants of F1 males and intact females) than by mother's line (the descendants of F1 females and intact males). (author)

  1. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Marmy, C.A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M. [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  2. Experimental Study of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study on the power conversion capabilities and structural loads of the WEPTOS wave energy converter. The investigation focuses mainly at identifying the performance of the WEPTOS prototype in a wide range of production wave states and at the moo......This report presents the results of an experimental study on the power conversion capabilities and structural loads of the WEPTOS wave energy converter. The investigation focuses mainly at identifying the performance of the WEPTOS prototype in a wide range of production wave states...... has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors. The client was participating during all the preparation and tests in the laboratory, and was represented by Tommy Larsen. The laboratory...

  3. An Experimental Study of a Pulsed Electromagnetic Plasma Accelerator

    Science.gov (United States)

    Thio, Y. C. Francis; Eskridge, Richard; Lee, Mike; Smith, James; Martin, Adam; Markusic, Tom E.; Cassibry, Jason T.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Experiments are being performed on the NASA Marshall Space Flight Center (MSFC) pulsed electromagnetic plasma accelerator (PEPA-0). Data produced from the experiments provide an opportunity to further understand the plasma dynamics in these thrusters via detailed computational modeling. The detailed and accurate understanding of the plasma dynamics in these devices holds the key towards extending their capabilities in a number of applications, including their applications as high power (greater than 1 MW) thrusters, and their use for producing high-velocity, uniform plasma jets for experimental purposes. For this study, the 2-D MHD modeling code, MACH2, is used to provide detailed interpretation of the experimental data. At the same time, a 0-D physics model of the plasma initial phase is developed to guide our 2-D modeling studies.

  4. Experimental Vibration Study on the Healthy and Delaminated Composite Plates

    International Nuclear Information System (INIS)

    Vibration based damage, in particular delamination detection, in the composite structures is an active research area. The present study is also on the dynamics of the composite plates with and without delamination based on the experimental study. The test plate made of E-glass fibre and epoxy resins has been used here. A piezo-electric shaker has been used to excite the composite plate and the acceleration responses were measured using the number of accelerometers. The dynamics of the delaminated composite plates were then compared with a healthy composite plate when the vibration experiments have been conducted at the lower modes. The paper will discuss the observations made on the measured vibration responses from both the healthy and the delaminated plates and the possibility of the delamination detection from the experimental vibration data.

  5. Experimental and analytical studies on pedestrian induced footbridge vibrations

    DEFF Research Database (Denmark)

    Gudmundsson, Gudmundur Valur; Ingólfsson, Einar Thór; Einarsson, Baldvin;

    2007-01-01

    This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic characteri......This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic...... models describing human-induced vibrations on structures in current literature and standards are explained, both for a single person walking or running and crowd loading. The measured vertical acceleration induced by single pedestrians was compared against the predictions and it was found that all...

  6. Comprehensive experimental study of scrap steel reinforcement bars

    International Nuclear Information System (INIS)

    Test results of comprehensive experimental investigations carried out in terms of tensile properties, merit no., Brinell Hardness, impact strength, ability to bend and rebend, torsional strength, chemical composition, microstructure. Also, a theoretical study based on statistical/reliability analysis and Finite Element simulation are presented for a very large number of steel bar samples manufactured from various types of steel scrap purchased from different cities of Pakistan and produced by a substantial number of manufacturers. This experimental study is mainly aimed at determining the suitability of these steel bars as reinforcement for R.C.C. construction, particularly due to complaints of users regarding sub-standard quality and reluctance of manufacturers to follow the prescriptions of PSI for standardization under Certification and Marks Ordinance, 1961. The results showed a wide variation of almost all the properties implying that they would not be suitable for important projects or the situations where dynamic forces such as those due to earthquake etc. are expected. (author)

  7. Study on the Genetic Experimental Method for the Induction of Micronucleus from Garlic Root Tip Cells with Coichicine%秋水仙素诱导大蒜微核的遗传学实验方法研究

    Institute of Scientific and Technical Information of China (English)

    徐秀芳; 张海洋; 于淑池

    2012-01-01

    [目的]比较不同浓度的秋水仙素和不同处理时间对诱导大蒜根尖细胞产生徽核情况的影响,为实验教学的微核试验提供一个取材方便、实验结果明显、稳定性好的方法.[方法]分别用0.05%、0.10%、0.20%的秋水仙素处理大蒜根尖24和36 h,计算微核率,据此评价大蒜对秋水仙素的敏感度和秋水仙素诱导微核的效果.[结果]0.05%、0.10%、0.20%的秋水仙素处理大蒜根尖24和36 h后,均能产生微核,且浓度越高,处理时间越长,微核率越高,同时产生的双微核与多微核细胞越多.[结论]秋水仙素和大蒜根尖是微核测试试验的理想材料组合.%[ Objective ] The aim was to compare the induction of micronucleus from garlic root tip cells with different concentrations of eolchi-cine and under different treatment durations, so as to supply a method with easy access to materials, clear and stable experimental results for the micronucleus experiment. [ Method ] The garlic root tips were treated respectively with 0.05% , 0.10% and 0.20% colchicine for 24 and 36 h, the rate of micronucieus was calculated to evaluate the sensitivity of garlic to colchicine and the colchicine-induced results of micronucleus. [ Result] Micronucleus was produced from all treatments, the higher the concentration of colchicine and the longer the treatment process, the higher the micronucleus rate and the more the double micronucleus and multi-micronucleus. [ Conclusion ] Colchicine and garlic root tip were the best materials for micronucleus experiment.

  8. An experimental study for the Cross Domain Author Profiling classification

    OpenAIRE

    Garciarena Ucelay, María José; Villegas, María Paula; Cagnina, Leticia; ERRECALDE, MARCELO LUIS

    2015-01-01

    Author Profiling is the task of predicting characteristics of the author of a text, such as age, gender, personality, native language, etc. This is a task of growing importance due to the potential applications in security, crime detection and marketing, among others. An interesting point is to study the robustness of a classifier when it is trained with a dataset and tested with others containing different characteristics. Commonly this is called cross domain experimentation. Although differ...

  9. Experimental studies toward the characterization of Inmetro's circulating water channel

    Science.gov (United States)

    Santos, A. M.; Alho, A. T. P.; Garcia, D. A.; Farias, M. H.; Massari, P. L.; Silva, V. V. S.

    2016-07-01

    Circulating water channels are facilities which can be used for conducting environmental, metrological and engineering studies. The Brazilian National Institute of Metrology-INMETRO has a water channel of innovative design, and the present work deals with the prior experimental investigation of its hydrodynamics performance. By using the optical technique PIV - Particle Image Velocimetry, under certain conditions, the velocity profile behavior in a region inside the channel was analyzed in order to evaluate the scope of applicability of such bench.

  10. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Weisz, A.

    This report presents the results of an experimental study of the wave energy converting abilities of the Langlee wave energy converter (WEC). It focused mainly on evaluating the power generating capabilities of the device, including investigations of the following issues: Scaling ratiosPTO loading...... different instruments was deployed to measure and record data. Tests were performed at scales of 1:30 and 1:20 based on the realized reference wave states....

  11. EXPERIMENTAL STUDIES ON UTILIZATION OF MURRUM AS HARD SHOULDER MATERIAL

    OpenAIRE

    PRADEEP MULEY; Dr. P.K. JAIN,; RAJEEV JAIN,

    2010-01-01

    Murrum is widely used material for the construction of pavement shoulders. Sometimes the available murrum may not satisfy the requirement of CBR and hence need to be modified. The locally available granular material like sand and/ or the crusher dust may be mixed to the soil to obtain the desired characteristics. The paperdiscusses results of the experimental study in which the quality of local murrum has been improved by adding stone dust. The index properties, compaction characteristics and...

  12. Emotional suppression in chronic fatigue syndrome (CFS): Experimental study

    OpenAIRE

    Rimes, Katharine Amber.; Ashcroft, Joanna Caroline; Bryan, Lauren; Chalder, Trudie

    2016-01-01

    Objective: Emotional processing differences in chronic fatigue syndrome (CFS) have been reported but have rarely been investigated experimentally. This study used self-report, observer ratings, and electrodermal responses to test hypotheses about emotion suppression and autonomic reactivity.Methods: Eighty adults with CFS and 80 healthy controls (HC) watched a distressing film clip. Half of each group were instructed to suppress their emotions and half were told to express their feelings as t...

  13. EXPERIMENTAL STUDIES OF MITIGATION MATERIALS FOR BLAST INDUCED TBI

    OpenAIRE

    Young, Laurence Retman; Goel, Rahul; Christou, George Alexander; Son, S. F.; Alley, M. D.

    2009-01-01

    The objective of this experimental study is to compare the effects of various materials obstructing the flow of a blast wave and the ability of the given material to reduce the damage caused by the blast. Several methods of energy transfer in blast wave flows are known or expected including: material interfaces with impedance mismatches, density changes in a given material, internal shearing, and particle fracture. The theory applied to this research is that the greatest energy transfer withi...

  14. An experimental study of a pin-fin heat exchanger

    OpenAIRE

    Ramthun, David L.

    2003-01-01

    Approved for public release; distribution is unlimited A detailed experimental study has been carried out on the heat transfer and pressure drop characteristics of a compact heat exchanger with pin fins. A modular wind-tunnel with a rectangular cross-section duct-flow area was constructed that would accommodate the heat exchanger test section with varying pin designs. The flow in the tunnel was achieved through a suction-type blower, and a leading entrance length section was added to achie...

  15. Experimental and Theoretical Studies of a Low Nox Swirl Burner

    OpenAIRE

    Spangelo, Øystein

    2004-01-01

    Nitrogen oxides emitted to the atmosphere can cause health problems for humans and environmental problems such as acid rain and global warming. The main part of the world energy consumption involves combustion; hence nitrogen oxide abatement in combustion is an important research field. Formation and reduction of NOx in combustion and the current regulations on NOx emissions are reviewed.A novel low NOx swirl stabilized gas burner concept, the Swirl Burner, has been studied experimentally, th...

  16. Respecifying lab ethnography an ethnomethodological study of experimental physics

    CERN Document Server

    Sormani, Philippe

    2014-01-01

    Respecifying Lab Ethnography delivers the first ethnomethodological study of current experimental physics in action, describing the disciplinary orientation of lab work and exploring the discipline in its social order, formal stringency and skilful performance - in situ and in vivo. In bringing together two major strands of ethnomethodological inquiry, reflexive ethnography and video analysis, which have hitherto existed in parallel, Respecifying Lab Ethnography introduces a practice-based video analysis. In doing so, the book recasts conventional distinctions to shed fresh light on methodolog

  17. Experimental study on natural convection boiling burnout in an annulus

    International Nuclear Information System (INIS)

    An experimental study was performed on burnout heat flux at low flow rates for low pressure steam-water upward flow in an annulus. The data indicated that a premature burnout occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that burnout heat flux observed can be well reproduced by a non-dimensional correlation derived from the previously obtained criterion for flow regime transition. (author)

  18. Experimental and analytical studies of high heat flux components for fusion experimental reactor

    International Nuclear Information System (INIS)

    In this report, the experimental and analytical results concerning the development of plasma facing components of ITER are described. With respect to developing high heat removal structures for the divertor plates, an externally-finned swirl tube was developed based on the results of critical heat flux (CHF) experiments on various tube structures. As the result, the burnout heat flux, which also indicates incident CHF, of 41 ± 1 MW/m2 was achieved in the externally-finned swirl tube. The applicability of existing CHF correlations based on uniform heating conditions was evaluated by comparing the CHF experimental data with the smooth and the externally-finned tubes under one-sided heating condition. As the results, experimentally determined CHF data for straight tube show good agreement, for the externally-finned tube, no existing correlations are available for prediction of the CHF. With respect to the evaluation of the bonds between carbon-based material and heat sink metal, results of brazing tests were compared with the analytical results by three dimensional model with temperature-dependent thermal and mechanical properties. Analytical results showed that residual stresses from brazing can be estimated by the analytical three directional stress values instead of the equivalent stress value applied. In the analytical study on the separatrix sweeping for effectively reducing surface heat fluxes on the divertor plate, thermal response of the divertor plate has been analyzed under ITER relevant heat flux conditions and has been tested. As the result, it has been demonstrated that application of the sweeping technique is very effective for improvement in the power handling capability of the divertor plate and that the divertor mock-up has withstood a large number of additional cyclic heat loads. (J.P.N.) 62 refs

  19. Clinical and Experimental Study on Treatment of Psoriasis Maculata by Leyin(乐银)

    Institute of Scientific and Technical Information of China (English)

    杨洪浦; 胡人杰; 齐云; 徐丽敏; 乔树芳

    2002-01-01

    Objective:To observe the therapeutic effect of Leyin (乐银, LY) in treating psoriasis mac-ulata (PM) and its effects on cellular immunity and vaginal epithelial cell mitosis in experimental mice.Methods: In this clinical study, 260 out-patients of PM were randomly divided into the observed group (n= 160) and the control group (n= 100), who were treated with oral intake of LY and Yinxieling granuleup study was also conducted on them. In the experimental study, delayed allergic model mice were treatedwith immunosuppressor (cyclophosphamide) and LY separately to observe the effects on their immunefunction and inhibition of vaginal epithelial cell proliferation. Results: In the observed group, 8 patients(5%) were cured, 32 (20%) basically cured, 48 (30%) markedly improved, 48 (30%) improved and 24(15 %) unchanged, the total effective rate being 85 %, while in the control group, the corresponding num-bers were 4, 8, 14, 38, 36 and 64% respectively, with the comparison of the total effective rate betweenthe two groups showing significant difference(P<0. 01). Adverse reactions were not found in the study.Experimental study showed that LY could enhance the immune function of mice and had a certain inhibito-ry effect on vaginal epithelial cell proliferation. Conclusion: LY could treat PM effectively and shows im-mune enhancing and anti-mitosis effect in mice.

  20. Oxygen sensing in neuroendocrine cells and other cell types: pheochromocytoma (PC12) cells as an experimental model.

    Science.gov (United States)

    Spicer, Zachary; Millhorn, David E

    2003-01-01

    A steady supply of oxygen is an absolute requirement for mammalian cells to maintain normal cellular functions. To answer the challenge that oxygen deprivation represents, mammals have evolved specialized cell types that can sense changes in oxygen tension and alter gene expression to enhance oxygen delivery to hypoxic areas. These oxygensensing cells are rare and difficult to study in vivo. As a result, pheochromocytoma (PC12) cells have become a vital in vitro model system for deciphering the molecular events that confer the hypoxia-resistant and oxygen-sensing phenotypes. Research over the last few years has revealed that the hypoxia response in PC12 cells involves the interactions of several signal transduction pathways (Ca2+/calmodulin-dependent kinases, Akt, SAPKs, and MAPKs) and transcription factors (HIFs, CREB, and c-fos/junB). This review summarizes the current understanding of the role these signal transduction pathways and transcription factors play in determining the hypoxic response. PMID:14739486

  1. Cell-Based Approaches in Periodontal Regeneration: A Systematic Review and Meta-Analysis of Periodontal Defect Models in Animal Experimental Work

    NARCIS (Netherlands)

    Yan, X.Z.; Yang, F.; Jansen, J.A.; Vries, R.B.M. de; Beucken, J.J.J.P van den

    2015-01-01

    Various cell types have been assessed for experimental periodontal tissue regeneration in a variety of animal models. Nonetheless, the efficacy of cell-based approaches for periodontal regeneration is still controversial. Therefore, the purpose of this study was to systematically review cell-based a

  2. Peribiliary Glands as a Niche of Extrapancreatic Precursors Yielding Insulin-Producing Cells in Experimental and Human Diabetes.

    Science.gov (United States)

    Carpino, Guido; Puca, Rosa; Cardinale, Vincenzo; Renzi, Anastasia; Scafetta, Gaia; Nevi, Lorenzo; Rossi, Massimo; Berloco, Pasquale B; Ginanni Corradini, Stefano; Reid, Lola M; Maroder, Marella; Gaudio, Eugenio; Alvaro, Domenico

    2016-05-01

    Peribiliary glands (PBGs) are niches in the biliary tree and containing heterogeneous endodermal stem/progenitors cells that can differentiate, in vitro and in vivo, toward pancreatic islets. The aim of this study was to evaluate, in experimental and human diabetes, proliferation of cells in PBGs and differentiation of the biliary tree stem/progenitor cells (BTSCs) toward insulin-producing cells. Diabetes was generated in mice by intraperitoneal injection of a single dose of 200 mg/kg (N = 12) or 120 mg/kg (N = 12) of streptozotocin. Liver, pancreas, and extrahepatic biliary trees were en bloc dissected and examined. Cells in PBGs proliferated in experimental diabetes, and their proliferation was greatest in the PBGs of the hepatopancreatic ampulla, and inversely correlated with the pancreatic islet area. In rodents, the cell proliferation in PBGs was characterized by the expansion of Sox9-positive stem/progenitor cells that gave rise to insulin-producing cells. Insulin-producing cells were located mostly in PBGs in the portion of the biliary tree closest to the duodenum, and their appearance was associated with upregulation of MafA and Gli1 gene expression. In patients with type 2 diabetes, PBGs at the level of the hepatopancreatic ampulla contained cells showing signs of proliferation and pancreatic fate commitment. In vitro, high glucose concentrations induced the differentiation of human BTSCs cultures toward pancreatic beta cell fates. The cells in PBGs respond to diabetes with proliferation and differentiation towards insulin-producing cells indicating that PBG niches may rescue pancreatic islet impairment in diabetes. These findings offer important implications for the pathophysiology and complications of this disease. Stem Cells 2016;34:1332-1342. PMID:26850087

  3. Experimental Study of Effect of Perfluorohexyloctane to Retina

    Institute of Scientific and Technical Information of China (English)

    Chunfang Li; Xiaoyan Ding; Lin Lu; Guanguang Feng; Huling Zheng

    2002-01-01

    Objective: To investigate the effect of perfluorohexvloctane to the retina of rabbit eyes.Methods: Perfluoroh-exyloctane (experimental group) or BSS(control group) intovitreous cavities of fifteen vitrectomized New Zealand white rabbits. A slit-lampbiomicroscope and an indirect ophthalmoscope were used to examine all the eyes pre- andpostoperation. Histopathological examination was performed after the rabbits weresacrificed. Results:Perfluorohexyloctane was injected into the vitreous cavity forming a single largeclear globe. No retinal detachment and cataract were found. The edema of outer plexiformlayer was significant, and then get thin, inner nuclear layer and ganglion cell bodies hada darker cytop: lasm and nucleoplasm. Conclusions: Perfluorohexyloctane in vitreous cavity had significant side effects on retinaAs a silicone solvent, it should be removed out completely after injection. We don′trecommend to use it as a new intraocular temponade.

  4. Spent Fuel Transportation Package Performance Study - Experimental Design Challenges

    International Nuclear Information System (INIS)

    Numerous studies of spent nuclear fuel transportation accident risks have been performed since the late seventies that considered shipping container design and performance. Based in part on these studies, NRC has concluded that the level of protection provided by spent nuclear fuel transportation package designs under accident conditions is adequate. [1] Furthermore, actual spent nuclear fuel transport experience showcase a safety record that is exceptional and unparalleled when compared to other hazardous materials transportation shipments. There has never been a known or suspected release of the radioactive contents from an NRC-certified spent nuclear fuel cask as a result of a transportation accident. In 1999 the United States Nuclear Regulatory Commission (NRC) initiated a study, the Package Performance Study, to demonstrate the performance of spent fuel and spent fuel packages during severe transportation accidents. NRC is not studying or testing its current regulations, a s the rigorous regulatory accident conditions specified in 10 CFR Part 71 are adequate to ensure safe packaging and use. As part of this study, NRC currently plans on using detailed modeling followed by experimental testing to increase public confidence in the safety of spent nuclear fuel shipments. One of the aspects of this confirmatory research study is the commitment to solicit and consider public comment during the scoping phase and experimental design planning phase of this research

  5. Directing experimental biology: a case study in mitochondrial biogenesis.

    Directory of Open Access Journals (Sweden)

    Matthew A Hibbs

    2009-03-01

    Full Text Available Computational approaches have promised to organize collections of functional genomics data into testable predictions of gene and protein involvement in biological processes and pathways. However, few such predictions have been experimentally validated on a large scale, leaving many bioinformatic methods unproven and underutilized in the biology community. Further, it remains unclear what biological concerns should be taken into account when using computational methods to drive real-world experimental efforts. To investigate these concerns and to establish the utility of computational predictions of gene function, we experimentally tested hundreds of predictions generated from an ensemble of three complementary methods for the process of mitochondrial organization and biogenesis in Saccharomyces cerevisiae. The biological data with respect to the mitochondria are presented in a companion manuscript published in PLoS Genetics (doi:10.1371/journal.pgen.1000407. Here we analyze and explore the results of this study that are broadly applicable for computationalists applying gene function prediction techniques, including a new experimental comparison with 48 genes representing the genomic background. Our study leads to several conclusions that are important to consider when driving laboratory investigations using computational prediction approaches. While most genes in yeast are already known to participate in at least one biological process, we confirm that genes with known functions can still be strong candidates for annotation of additional gene functions. We find that different analysis techniques and different underlying data can both greatly affect the types of functional predictions produced by computational methods. This diversity allows an ensemble of techniques to substantially broaden the biological scope and breadth of predictions. We also find that performing prediction and validation steps iteratively allows us to more completely

  6. Advanced Cell Development and Degradation Studies

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; C. M. Stoots; J. S. Herring; R. C. O' Brien; K. G. Condie; M. Sohal; G. K. Housley; J. J. Hartvigsen; D. Larsen; G. Tao; B. Yildiz; V. Sharma; P. Singh; N. Petigny; T. L. Cable

    2010-09-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. From 2003 – 2009, this work was sponsored by the DOE Nuclear Hydrogen Initiative (NHI). Starting in 2010, the HTE research program has been sponsored by the Next Generation Nuclear Plant (NGNP) program. HTSE research priorities in FY10 are centered on understanding and reducing cell and stack performance degradation to an acceptable level to advance the technology readiness level of HTSE and to justify further large-scale demonstration activities. This report provides a summary of our FY10 experimental program, which has been focused on advanced cell and stack development and degradation studies. Advanced cell and stack development activities are under way at five technology partners: MSRI, Versa Power, Ceramatec, NASA Glenn, and St. Gobain. Performance evaluation of the advanced technology cells and stacks has been performed by the technology partners, by MIT and the University of Connecticut and at the INL HTE Laboratory. Summaries of these development activities and test results are presented.

  7. Tubular engraftment and myofibroblast differentiation of recipient-derived cells after experimental kidney transplantation

    NARCIS (Netherlands)

    Broekema, Martine; Harmsen, Martin C.; Koerts, Jasper A.; Van Kooten, Theo G.; Navis, Gerjan; Van Luyn, Marja J. A.; Popa, Eliane R.

    2007-01-01

    Background. In human renal allografts, recipient-derived cells engrafted in various kidney substructures, have been detected in the long term after transplantation. Here we investigated tubular engraftment and myofibroblast differentiation of recipient-derived cells at short term after experimental

  8. Cerebral transplantation of encapsulated mesenchymal stem cells improves cellular pathology after experimental traumatic brain injury

    DEFF Research Database (Denmark)

    Heile, Anna M B; Wallrapp, Christine; Klinge, Petra M;

    2009-01-01

    PURPOSE: "Naked" human mesenchymal stem cells (MSC) are neuro-protective in experimental brain injury (TBI). In a controlled cortical impact (CCI) rat model, we investigated whether encapsulated MSC (eMSC) act similarly, and whether efficacy is augmented using cells transfected to produce the neu...

  9. Mesenchymal stem cells abrogate experimental asthma by altering dendritic cell function.

    Science.gov (United States)

    Zeng, Shao-Lin; Wang, Li-Hui; Li, Ping; Wang, Wei; Yang, Jiong

    2015-08-01

    Mesenchymal stem cells (MSCs) have been investigated in the treatment of numerous autoimmune diseases. However, the immune properties of MSCs on the development of asthma have remained to be fully elucidated. Airway dendritic cells (DCs) have an important role in the pathogenesis of allergic asthma, and disrupting their function may be a novel therapeutic approach. The present study used a mouse model of asthma to demonstrate that transplantation of MSCs suppressed features of asthma by targeting the function of lung myeloid DCs. MSCs suppressed the maturation and migration of lung DCs to the mediastinal lymph nodes, and thereby reducing the allergen-specific T helper type 2 (Th2) response in the nodes. In addition, MSC-treated DCs were less potent in activating naive and effector Th2 cells and the capacity of producing chemokine (C-C motif) ligand 17 (CCL17) and CCL22, which are chemokines attracting Th2 cells, to the airways was reduced. These results supported that MSCs may be used as a potential treatment for asthma. PMID:25936350

  10. Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

    Science.gov (United States)

    Nguyen, Gia Luong Huu

    Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the

  11. 病毒灭活血浆对人γδT细胞功能影响的实验研究%Experimental study of virus inactivated plasma for human γδT cell function influence

    Institute of Scientific and Technical Information of China (English)

    姚仁南; 陈玲; 陈娜云; 刘军权; 周忠海; 陈复兴; 孙阳

    2012-01-01

    Objective To study the influence of virus inactivated plasma for human γδT cell growth and function. Methods The isopentenyl pyrophosphate assay were used to amplify human peripheral blood γδT cells in vitro. The γδT cells were cultured with 10 % virus inactivated plasma and 10 % fresh frozen plasma,the amplification factors were detected at culture before,after 5 days and 10 days; The flow cytometry were detected cell surface markers,Granzyme B,perform and CD107a of γδT cultured after 10 days. Results The 10 % fresh frozen plasma and virus inactivated plasma on human γδT cells cultured by amplification at 10 days,which were increased from 3.12 % to 80.46 % and 81.18 %,5 days and 10 days of cell proliferation multiples were 11.65 ± 211,38.21 ± 157 and 11.77 ± 2.13,37.11 ± 1.81,respectively. The expression of CD107a,perform and Granzyme B were 90.54 % ± 1.99 % ,23.47 % ± 3.18 %,35.47 % ± 2.42 % and 90.22 % ± 2.21 %,22.58 % ± 3.41 %,34.63 % ± 2.22 %,respectively. There was no statistically significant difference between 2 groups (P > 0.05). Conclusion It is demonstrated that the virus inactivated plasma in certain concentration of human γδT cell growth and proliferation,Granzyme B,perform and CD107a expression and fresh frozen plasma have no obvious difference.%目的 探讨病毒灭活血浆对人γδT细胞生长和功能的影响.方法 取人外周血γδT细胞,用异戊烯焦磷酸法体外扩增.用10%病毒灭活血浆和10%新鲜冰冻血浆分别培养γδT细胞,分别检测培养前、培养5d和10d后的扩增倍数;用流式细胞术分别检测培养10d后的γδT细胞表面标记,即颗粒酶B、穿孔素和CD107a的表达等.结果 10%新鲜冰冻血浆和10%病毒灭活血浆对人γδT细胞培养10d时,由扩增前的3.12%增加到80.46%和81.18%,5d和10d的细胞增殖倍数分别为11.65±2.11、38.21±1.57和11.77±2.13、37.11±1.81,CD107a、穿孔素、颗粒酶B含量表达分别为90.54%±1.99

  12. A Combined Molecular Dynamics and Experimental Study of Doped Polypyrrole.

    Science.gov (United States)

    Fonner, John M; Schmidt, Christine E; Ren, Pengyu

    2010-10-01

    Polypyrrole (PPy) is a biocompatible, electrically conductive polymer that has great potential for battery, sensor, and neural implant applications. Its amorphous structure and insolubility, however, limit the experimental techniques available to study its structure and properties at the atomic level. Previous theoretical studies of PPy in bulk are also scarce. Using ab initio calculations, we have constructed a molecular mechanics force field of chloride-doped PPy (PPyCl) and undoped PPy. This model has been designed to integrate into the OPLS force field, and parameters are available for the Gromacs and TINKER software packages. Molecular dynamics (MD) simulations of bulk PPy and PPyCl have been performed using this force field, and the effects of chain packing and electrostatic scaling on the bulk polymer density have been investigated. The density of flotation of PPyCl films has been measured experimentally. Amorphous X-ray diffraction of PPyCl was obtained and correlated with atomic structures sampled from MD simulations. The force field reported here is foundational for bridging the gap between experimental measurements and theoretical calculations for PPy based materials. PMID:21052521

  13. Thermodynamic assessment and experimental study of Mg–Gd alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hampl, M. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Blawert, C.; Silva Campos, M.R.; Hort, N.; Peng, Q.; Kainer, K.U. [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Magnesium Innovation Centre, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Schmid-Fetzer, R., E-mail: schmid-fetzer@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2013-12-25

    Highlights: •Solid solubity of Gd in (Mg) experimentally studied. •Consistent thermodynamic calculation of Mg–Gd phase diagram developed. •Vapor pressure and enthalpy of formation data analyzed by Calphad method. •Three error sources identified in earlier approximate enthalpy derivation. •Claimed systematic trends in enthalpies of formation disputed. -- Abstract: The solid solubility of Gd in (Mg) is studied experimentally using microstructure, chemical and EDX analysis on permanent mould chill cast samples which were annealed for 1–14 days at 300–550 °C. Based on those key data and all the critically assessed experimental phase equilibrium and thermodynamic data of the Mg–Gd system two Calphad-type thermodynamic descriptions are developed. This provides calculated phase diagrams, and an inherent inconsistency between the vapor pressure data and the Mg-rich phase diagram is indicated. A previous misperception of “experimental” enthalpy of formation data of binary Gd{sub x}Mg{sub y} intermetallic compounds is also revealed. The assumption of systematic trends in these key thermodynamic data for the series of rare earth elements R = (La, Ce, Pr, Nd, Sm, Gd) is scrutinized.

  14. Game theory and experimental games the study of strategic interaction

    CERN Document Server

    Colman, Andrew M

    1982-01-01

    Game Theory and Experimental Games: The Study of Strategic Interaction is a critical survey of the essential ideas of game theory and the findings of empirical research on strategic interaction. Some experiments using lifelike simulations of familiar kinds of strategic interactions are presented, and applications of game theory to the study of voting, the theory of evolution, and moral philosophy are discussed.Comprised of 13 chapters, this volume begins with an informal definition of game theory and an outline of the types of social situations to which it applies. Games of skill, games of cha

  15. Experimental Study on the WavePiston Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Angelelli, E.

    This report presents the results of an experimental study of the power performance of the WavePiston wave energy converter. It focuses mainly on evaluating the power generating capabilities of the device and the effect of the following issues: Scaling ratios PTO loading Wave height and wave period...... dependency Oblique incoming waves Distance between plates During the study, the model supplied by the client, WavePiston, has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors....

  16. On the proper study design applicable to experimental balneology

    Science.gov (United States)

    Varga, Csaba

    2016-08-01

    The simple message of this paper is that it is the high time to reevaluate the strategies and optimize the efforts for investigation of thermal (spa) waters. Several articles trying to clear mode of action of medicinal waters have been published up to now. Almost all studies apply the unproven hypothesis, namely the inorganic ingredients are in close connection with healing effects of bathing. Change of paradigm would be highly necessary in this field taking into consideration the presence of several biologically active organic substances in these waters. A successful design for experimental mechanistic studies is approved.

  17. Red emitting NLOphoric 3-styryl coumarins: Experimental and computational studies

    Science.gov (United States)

    Tathe, Abhinav B.; Sekar, Nagaiyan

    2016-01-01

    The coumarin molecules are versatile fluorophores and can be modified synthetically to give desired properties. The molecules studied have 4-cyano group as an assistance to original chromophore and imparts a red shift. These coumarins were expected to show good non-linear optical (NLO) properties. The experimental and theoretical methods were employed to determine their NLO properties. Directional components of hyperpolarizabilities were calculated and showed a variation according to the placement of electron pulling groups. Studied molecules show a very high (494-794 times of urea) total first order hyperpolarizability. The NLO properties of the molecules were found to be solvent dependant.

  18. Experimental study of hydronic panels system and its environment

    International Nuclear Information System (INIS)

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  19. Experimental and theoretical studies on visible light attenuation in water

    CERN Document Server

    Simpson, A; Cho, H J; Liu, H

    2014-01-01

    In this study we describe lab experiments on determining the above water reflectance Rrs coefficient, and the water attenuation coefficient Kd for fresh water. Different types of screens (totally absorbent, gray, etc.) were submerged in water (0-0.6 m) and illuminated from outside. The spectral density of the water leaving radiance was measured for different depths. The results were ran by a code which took into account the geometry of the incident irradiation, the geometry of the screen under water, and boundary conditions at the water surface provided by the radiation transfer theory. From the experimental data and our model we obtain the spectral distribution of the attenuation coefficient for fresh water and compared it with other data in literature. These experiments, performed in the Nonlinear Wave Lab at ERAU# represent just a preliminary calibration of the experimental protocol. More tests with water of different degrees of turbidity, and possibly wave filed at the water surface are in progress and wi...

  20. Experimental Study of Sediment Incipience Under Complex Flows

    Institute of Scientific and Technical Information of China (English)

    LIU Chunrong; DENG Liying; HUANG Zhenhua; HUHE Aode

    2008-01-01

    Sediment incipience under flows passing a backward-facing step was studied. A series of experiments were conducted to measure scouring depth, probability of sediment incipience, and instantaneous flow velocity field downstream of a backward-facing step. Instantaneous flow velocity fields were measured by using Particle Image Velocimetry (PIV), and an image processing method for determining probability of sediment incipience was employed to analyze the experimental data.The experimental results showed that the probability of sediment incipience was the highest near the reattachment point, even though the near-wall instantaneous flow velocity and the Reynolds stress were both much higher further downstream of the backward-facing step. The possible mechanisms are discussed for the sediment incipience near the reattachment point.

  1. Experimental Studies on Combustion Characteristics of Mixed Municipal Solid Waste

    Institute of Scientific and Technical Information of China (English)

    Fan Jiang; Zhonggang Pan; Shi Liu; Haigang Wang

    2003-01-01

    In our country, municipal solid wastes (MSW) are always burnt in their original forms and only a few pretreatments are taken. Therefore it is vital to study the combustion characteristics of mixed waste. In this paper,thermogravimetric analysis and a lab scale fluidized bed facility were used as experimental means. The data in two different experimental systems were introduced and compared. It took MSW 3~3.5 rain to burn out in FB, but in thermogravimetric analyzer, the time is 20~25 min. It can be concluded that, in general, the behavior of a mixture of waste in TGA can be expressed by simple combination of individual components of the waste mixtures.Only minor deviations from the rule were observed. Yet, in Fluidized Bed, it was found that, for some mixtures,there was interference among the components during fluidized bed combustion.

  2. Experimental and analytical studies on aseismic design of ventilation ducts

    International Nuclear Information System (INIS)

    For seismic resistant design of the ventilation ducts, it is the most popular and convenient way to idealize duct as a simple beam model and to compute maximum support spacing which makes duct rigid enough. However, few practical data are available to assume the precise stiffness of thinwalled duct on which accurate prediction of dynamic properties depends essentially. In this paper, the experimental study including the vibration tests and the static load tests with regard to two full scale duct models is described and a comparison between experimental and analytical results on the dynamic properties, the deflections and the stress distributions is discussed. Also, the mode of failure of the ducts due to vertically applied static load with negative internal pressure is observed. (orig.)

  3. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

  4. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: nestorfonseca5@hotmail.co [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  5. Experimental and theoretical study on THz spectrum artesunate

    Science.gov (United States)

    Zhang, Ai-Bing; Kong, Ling-Gao; Wang, Shi-Jin; Li, Lei; Zheng, Xiang-Zhi

    2008-10-01

    Artesunate is a very effective drug to treat malaria. They are studied experimentally by Terahertz (THz) time-domain spectroscopy (THz-TDS), and the characteristic absorption spectra are obtained in the range of 0.2 to 2.6 THz. The vibrational frequencies are calculated using the density functional theory (DFT). Theoretical results show that 0.71, 1.94 and 2.46 THz are significant agreement with the experimental results in 0.87, 1.82 and 2.46THz, and identification of vibrational modes are given. The calculated results further confirm that the characteristic frequencies come from the collective vibrational modes. The results suggest that the use of the THz-TDS technique can be an effective way to inspect for Chinese medicine.

  6. Experimental study of effect of stenosis geometry on flow parameters

    Directory of Open Access Journals (Sweden)

    Veselý Ondřej

    2015-01-01

    Full Text Available A stenosis is a narrowing in a tubular organ or structure. In medicine, vessel stenosis poses health risks for people. In this work, experimental investigations of pressure loss coefficient for varying stenosis eccentricity and shape were performed. Five models of different geometry were studied; all models were stenosis of 75 % area reduction. The flow conditions approximate physiological flow. The measuring range of Reynolds number was from 130 to 2730, measured values of pressure loss coefficient were from 12 to 20. The steady experimental results indicated that static pressure loss coefficient is affected by the shape of stenosis, but it was affected more significantly by the eccentricity. Visualization experiments have been performed in Polycarbonate models.

  7. Design and Experimental Study on Spinning Solid Rocket Motor

    Science.gov (United States)

    Xue, Heng; Jiang, Chunlan; Wang, Zaicheng

    The study on spinning solid rocket motor (SRM) which used as power plant of twice throwing structure of aerial submunition was introduced. This kind of SRM which with the structure of tangential multi-nozzle consists of a combustion chamber, propellant charge, 4 tangential nozzles, ignition device, etc. Grain design, structure design and prediction of interior ballistic performance were described, and problem which need mainly considered in design were analyzed comprehensively. Finally, in order to research working performance of the SRM, measure pressure-time curve and its speed, static test and dynamic test were conducted respectively. And then calculated values and experimental data were compared and analyzed. The results indicate that the designed motor operates normally, and the stable performance of interior ballistic meet demands. And experimental results have the guidance meaning for the pre-research design of SRM.

  8. New experimental studies of the production of 44Ti

    Science.gov (United States)

    Robertson, Daniel; Collon, Philippe; Goerres, Joachim; Wiescher, Michael; Becker, Hans Werner

    2009-10-01

    The main production reaction of 44Ti observed in core collapse supernovae is the 40Ca(α,γ)44Ti reaction. A number of different experimental studies have been performed over the last years to determine the stellar reaction rate. These measurements were based on in-beam gamma spectroscopy techniques, accelerator mass spectrometer (AMS) techniques, and inverse reaction techniques with a recoil separator for separating and detecting the reaction products. The experimental results showed drastic differences. New experiments have been performed at the DTL Bochum and at the NSL Notre Dame using gamma spectroscopy and AMS techniques, respectively to investigate the reaction and the present discrepancies in the predictions. The results of the experiments will be presented and the impact on the reaction rate will be discussed.

  9. Experimental and modeling study of the oxidation of xylenes

    CERN Document Server

    Battin-Leclerc, F; Glaude, P A; Belmekki, N; Battin-Leclerc, Fr\\'{e}d\\'{e}rique; Bounaceur, Roda; Glaude, Pierre-Alexandre; Belmekki, Najib

    2006-01-01

    This paper describes an experimental and modeling study of the oxidation of the three isomers of xylene (ortho-, meta- and para-xylenes). For each compound, ignition delay times of hydrocarbon-oxygen-argon mixtures with fuel equivalence ratios from 0.5 to 2 were measured behind reflected shock waves for temperatures from 1330 to 1800 K and pressures from 6.7 to 9 bar. The results show a similar reactivity for the three isomers. A detailed kinetic mechanism has been proposed, which reproduces our experimental results, as well as some literature data obtained in a plug flow reactor at 1155 K showing a clear difference of reactivity between the three isomers of xylene. The main reaction paths have been determined by sensitivity and flux analyses and have allowed the differences of reactivity to be explained.

  10. Experimental and theoretical study of metal combustion in oxygen flows

    CERN Document Server

    El-Rabii, Hazem; Muller, Maryse

    2016-01-01

    The effects of oxygen flow speed and pressure on the iron and mild steel combustion are investigated experimentally and theoretically. The studied specimens are vertical cylindrical rods subjected to an axial oxygen flow and ignited at the upper end by laser irradiation. Three main stages of the combustion process have been identified experimentally: (1) Induction period, during which the rod is heated until an intensive metal oxidation begins at its upper end; (2) Static combustion, during which a laminar liquid "cap" slowly grows on the upper rod end; and, after the liquid cap detachment from the sample, (3) Dynamic combustion, which is characterized by a rapid metal consumption and turbulent liquid motions. An analytical description of these stages is given. In particular, a model of the dynamic combustion is constructed based on the turbulent oxygen transport through the liquid metal-oxide flow. This model yields a simple expression for the fraction of metal burned in the process, and allows one to calcul...

  11. Experimental study of critical flow of water at supercritical pressure

    Institute of Scientific and Technical Information of China (English)

    Yuzhou CHEN; Chunsheng YANG; Shuming ZHANG; Minfu ZHAO; Kaiwen DU; Xu CHENG

    2009-01-01

    Experimental studies of the critical flow of water were conducted under steady-state conditions with a nozzle 1.41mm in diameter and 4.35 mm in length, covering the inlet pressure range of 22.1-26.8 MPa and inlet temperature range of 38^74°C. The parametric trend of the flow rate was investigated, and the experimental data were compared with the predictions of the homogeneous equilibrium model, the Bernoulli correlation, and the models used in the reactor safety analysis code RELAP5/ MOD3.3. It is concluded that in the near or beyond pseudo-critical region, thermal-dynamic equilibrium is dominant, and at a lower temperature, choking does not occur. The onset of the choking condition is not predicted reasonably by the RELAP5 code.

  12. An experimental study on recovering heat from domestic drain water

    Science.gov (United States)

    Ramadan, Mohamad; Al Shaer, Ali; Haddad, Ahmad; Khaled, Mahmoud

    2016-07-01

    This paper concerns an experimental study on a system of heat recovery applied to domestic drain water pipes. The concept suggested consists of using the heat still present in the drain water as a preheating/heating source to the cold water supply of the building. To proceed, an appropriate experimental setup is developed and a coil heat exchanger is used as heat transfer device in the recovery system. Several scenarios are simulated and corresponding parameters are recorded and analyzed. It was shown that the suggested recovery concept can considerably preheat the cold water supply and then decrease the energy consumption. Particularly, up to 8.6 kW of heat were recovered when the cold water supply is initially at 3 °C.

  13. Experimental study on autologous of rabbit adipose - derived stem cells transplantation%兔脂肪干细胞增强脂肪移植效果的实验研究

    Institute of Scientific and Technical Information of China (English)

    杨涛; 杨勇; 王艳; 胡晓光

    2014-01-01

    Objective:To establish an animal model for the injectable transPlantation fat tissue transPlantation and to investigate the morPhological changes of rejection after ear transPlantation in rabbit. Methods:All 24 healthy New Zealand white rabbits were divided into four grouPs randomly. The autologous adiPose granule(AG)were imPlanted in the ears of the rabbits as the exPeriment grouP A(n = 6). The autologous adiPose granule(AG)combined with Platelet - rich fibrin(PRF)were imPlanted in ears as the exPeriment grouP B(n = 6). The autologous adiPose gran-ule(AG)combined with autologous adiPose - derived stem cells(ADSCs)were imPlanted in ears as the exPeriment grouP C(n = 6). The autologous adiPose granule(AG)combined with Platelet - rich fibrin(PRF)and autologous adiPose - derived stem cells(ADSCs)were imPlanted in the ears were the control grouP D(n = 6). At month 1,3 and 6 after transPlantation,the survival rates of transPlanted ears,eE staining,rabbit ears light transmission exPeri-ments were Performed. Results:At month 1,3 and 6 after transPlantation,the survival rates of transPlanted ears,eE staining,rabbit ears light transmission exPeriments,the differences of the grouP D and grouP A,B,C were statistical significant(P ﹤ 0. 05). Conclusion:The adiPose granule(AG)combined with Platelet - rich fibrin(PRF)and adi-Pose - derived stem cells(ADSCs)can imProve the survival rate of transPlanted fat tissue and Provide exPerimental basis for clinical fat transPlantation.%目的:建立兔耳脂肪移植模型,观察兔脂肪干细胞( adiPose - derived stem cells,ADSCs)复合脂肪颗粒(adiPose granule,AG)和富血小板纤维蛋白(Platelet - rich fibrin,PRF)移植后的形态学变化,为临床脂肪干细胞移植提供实验依据。方法:以健康新西兰家兔为实验动物,共取24只,随机分成4组(n =6):A 组移植物为 AG;B 组 AG + PRF;C 组 AG + ADSCs;D 组 AG + PRF + ADSCs。在术后1、3、6个月,用 B

  14. Combustion behaviour of pulverised wood - Numerical and experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Lixin Tao [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-05-01

    This report presents the experimental results achieved in an on-going project financed by STEM (Energimyndigheten) within the research program 'Gasification and combustion of solid fuels', during the first phase of the project (2001-03-05 to 2002-03-05). The project is a collaboration project between LTH and TPS on combined numerical modelling/experimental investigation on combustion of pulverised wood. Particularly TPS carry out the experimental investigation in a laboratory vertical furnace. During the project, the experimental rig has been developed. The experimental furnace has an inner diameter of 0.25 m and a height of 4 m. A pulverised wood flame is established using an axial burner that is installed on the top of the furnace. Experimental study on a selected pulverised wood with determined size distribution and anisotropy character has been carried out in this furnace. During the experiment, the wall temperatures of the furnace were continuously measured using 8 thermocouples of type K that are installed on the wall with a spacing about 0.5 m. The gas temperatures in the furnace were monitored using 5 fixed suction pyrometers that are placed along the centre of the furnace. At the bottom of the furnace, a fixed gas-sampling probe was installed. The flue gas concentrations were continuously monitored with on-line gas analysers. The extent of combustion was measured through the analysis of sampled gaseous products and condensable solid products. A movable liquid quench probe was used to carry out the gas and solid sampling through a number of sampling holes that are opened along the furnace wall. The quench liquor used is an alkaline water solution containing a small amount of a detergent to dissolve HCN and tar. The quench liquor and solid samples were separated and collected in a knockout pot. The gas was filtered and passed through two bubblers with acidic solution to collect NH{sub 3}. The gas concentrations were then analysed with on-line gas

  15. Experimental researches on treatment of end-stage nephropathy with stem cells transplantation

    International Nuclear Information System (INIS)

    Stem cell possesses the capability of self-regeneration and multidirectional differentiation. Although renal transplantation being the best way for the treatment of end-stage nephropathy, the shortage of donor kidney arouses the treatment with transplantation of stem cells taking emphasis in recent years. The process and mechanism of this therapy are complicated and the authors review in detail the experimental research advancement on stem cells engraftment for the treatment. The correlative interventional technology is also evaluated. (authors)

  16. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky

    2008-11-01

    Full Text Available Joel E Bialosky1*, Adam T Hirsh2,3, Michael E Robinson2,3, Steven Z George1,3*1Department of Physical Therapy; 2Department of Clinical and Health Psychology; 3Center for Pain Research and Behavioral Health, University of Florida, Gainesville, Florida, USAAbstract: Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT. Outcome measures of pain tolerance and pain intensity were recorded. No change was noted in catastrophizing immediately following the CPT (F(1,84 = 0.10, p = 0.75, partial η2 < 0.01 independent of group assignment (F(4,84 = 0.78, p = 0.54, partial η2 = 0.04. Pain tolerance (F(4 = 0.67, p = 0.62, partial η2 = 0.03 and pain intensity (F(4 = 0.73, p = 0.58, partial η2 = 0.03 did not differ by group. This study suggests catastrophizing may be difficult to manipulate through experimental pain procedures and repetition of specific catastrophizing statements was not sufficient to change levels of catastrophizing. Additionally, pain tolerance and pain intensity did not differ by group assignment. This study has implications for future studies attempting to experimentally manipulate pain catastrophizing.Keywords: pain, catastrophizing, experimental, cold pressor task, pain catastrophizing scale

  17. The Role of T cell PPAR γ in mice with experimental inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Hontecillas Raquel

    2010-06-01

    Full Text Available Abstract Background Peroxisome proliferator-activated receptor γ (PPAR γ is a nuclear receptor whose activation has been shown to modulate macrophage and T cell-mediated inflammation. The objective of this study was to investigate the mechanisms by which the deletion of PPAR γ in T cells modulates immune cell distribution and colonic gene expression and the severity of experimental IBD. Methods PPAR γ flfl; CD4 Cre+ (CD4cre or Cre- (WT mice were challenged with 2.5% dextran sodium sulfate in their drinking water for 0, 2, or 7 days. Mice were scored on disease severity both clinically and histopathologically. Flow cytometry was used to assess lymphocyte and macrophage populations in the blood, spleen, and mesenteric lymph nodes (MLN. Global gene expression in colonic mucosa was profiled using Affymetrix microarrays. Results The deficiency of PPAR γ in T cells accelerated the onset of disease and body weight loss. Examination of colon histopathology revealed significantly greater epithelial erosion, leukocyte infiltration, and mucosal thickening in the CD4cre mice on day 7. CD4cre mice had more CD8+ T cells than WT mice and fewer CD4+FoxP3+ regulatory T cells (Treg and IL10+CD4+ T cells in blood and MLN, respectively. Transcriptomic profiling revealed around 3000 genes being transcriptionally altered as a result of DSS challenge in CD4cre mice. These included up-regulated mRNA expression of adhesion molecules, proinflammatory cytokines interleukin-6 (IL-6 and IL-1β, and suppressor of cytokine signaling 3 (SOCS-3 on day 7. Gene set enrichment analysis (GSEA showed that the ribosome and Krebs cycle pathways were downregulated while the apoptosis pathway was upregulated in colons of mice lacking PPAR γ in T cells. Conclusions The expression of PPAR γ in T cells is involved in preventing gut inflammation by regulating colonic expression of adhesion molecules and inflammatory mediators at later stages of disease while favoring the recruitment

  18. Experimental study of rat mesenchymal stem cells transfected with Sonic Hedgehog gene%Shh基因转染大鼠骨髓间充质干细胞的可行性

    Institute of Scientific and Technical Information of China (English)

    吴晓明; 唐滔; 杨进福; 谭志平; 张伟

    2012-01-01

    Objective To evaluate the feasibility of genetic modification of mesenchymal stem cells (MSC) with Sonic Hedgehog(Shh) gene.Methods The pcDNA3.l-Shh eukaryotic expression plasmid was constructed and its correctness evaluated by the restriction enzyme analysis and sequencing. MSC were isolated from Wistar rats by density gradient centrifugation and purified,transfected with pcDNA3.1-Shh,blank plasmid pcDNA3.1 ( - ) or pmaxGFP respectively by NucleofectorTM.The protein expression of Shh in MSC was detected by Western blot after 48 hours.Results Correct construction of pcDNA3.1-Shh was identified by the methods of restriction enzyme analysis and nucleotide sequence determination. The expression of green fluorescent protein (GFP) could be observed by fluorescence microscopy after 48 hours.The expression of Shh gene was detected by Western blot.But the MSC transfected with empty plasmid expression was not detected.Conclusions Recombinant Eukaryotic expression plasmid pcDNA3.1-Shh is successfully detected in rat MSC.It may provide experimental rationales for the future gene therapy.%目的 探讨Sonic Hedgehog(Shh)基因有效转染大鼠骨髓间充质干细胞(BMSC)的可行性.方法 构建pcDNA3.1-Shh真核表达质粒,酶切和测序鉴定.密度梯度离心-贴壁培养法获取Wistar大鼠BMSC,电击穿孔法将pcDNA3.1-Shh、pcDNA3.1(一)空质粒和pmaxGFP报告质粒转染进BMSC,48 h后Western印迹法检测Shh基因的表达情况.结果 酶切和测序结果证实pcDNA3.1-Shh正确性.转染48 h后,荧光显微镜可观察到绿色荧光蛋白(GFP)的表达,有40%以上的细胞发出绿色荧光.Western印迹法检测证实有Shh基因表达,而转染pcDNA3.1(一)空质粒的BBMSC未检测到表达.结论 重组真核表达质粒pcDNA3.1-Shh转染大鼠BMSC后能有效表达Shh基因,为进一步Shh基因与细胞联合治疗大鼠心肌缺血模型提供了实验依据.

  19. Effects of ionizing radiation on bone cell differentiation in an experimental murine bone cell model

    Science.gov (United States)

    Baumstark-Khan, Christa; Lau, Patrick; Hellweg, Christine; Reitz, Guenther

    During long-term space travel astronauts are exposed to a complex mixture of different radiation types under conditions of dramatically reduced weight-bearing activity. It has been validated that astronauts loose a considerable amount of bone mass at a rate up to one to two percent each month in space. Therapeutic doses of ionizing radiation cause bone damage and increase fracture risks after treatment for head-and-neck cancer and in pelvic irradiation. For low radiation doses, the possibility of a disturbed healing potential of bone was described. Radiation induced damage has been discussed to inflict mainly on immature and healing bone. Little is known about radiation effects on bone remodelling and even less on the combined action of microgravity and radiation. Bone remodelling is a life-long process performed by balanced action of cells from the osteoblast and osteoclast lineages. While osteoblasts differentiate either into bone-lining cells or into osteocytes and play a crucial role in bone matrix synthesis, osteoclasts are responsible for bone resorption. We hypothesize that the balance between bone matrix assembly by osteocytes and bone degradation by osteoclasts is modulated by microgravity as well as by ionizing radiation. To address this, a cell model consisting of murine cell lines with the potential to differentiate into bone-forming osteoblasts (OCT-1, MC3T3-E1 S24, and MC3T3-E1 S4) was used for studying radiation response after exposure to simulated components of cosmic radiation. Cells were exposed to graded doses of 150 kV X-rays, α particles (0.525 MeV/u, 160 keV/µm; PTB, Braunschweig, Germany) and accelerated heavy ions (75 MeV/u carbon, 29 keV/µm; 95 MeV/u argon, 230 keV/µm; GANIL, Caen, France). Cell survival was measured as colony forming ability; cell cycle progression was analyzed via fluorescence-activated cell scanning (FACS) by measurement of the content of propidium iodide-stained DNA, DNA damage was visualized by γH2AX

  20. Experimental Studies of the Effects of Anode Composition and Process Parameters on Anode Slime Adhesion and Cathode Copper Purity by Performing Copper Electrorefining in a Pilot-Scale Cell

    Science.gov (United States)

    Zeng, Weizhi; Wang, Shijie; Free, Michael L.

    2016-06-01

    Copper electrorefining tests were conducted in a pilot-scale cell under commercial tankhouse environment to study the effects of anode compositions, current density, cathode blank width, and flow rate on anode slime behavior and cathode copper purity. Three different types of anodes (high, mid, and low impurity levels) were used in the tests and were analyzed under SEM/EDS. The harvested copper cathodes were weighed and analyzed for impurities concentrations using DC Arc. The adhered slimes and released slimes were collected, weighed, and analyzed for compositions using ICP. It was shown that the lead-to-arsenic ratio in the anodes affects the sintering and coalescence of slime particles. High current density condition can improve anode slime adhesion and cathode purity by intensifying slime particles' coalescence and dissolving part of the particles. Wide cathode blanks can raise the anodic current densities significantly and result in massive release of large slime particle aggregates, which are not likely to contaminate the cathode copper. Low flow rate can cause anode passivation and increase local temperatures in front of the anode, which leads to very intense sintering and coalescence of slime particles. The results and analyses of the tests present potential solutions for industrial copper electrorefining process.