Search Results - (Author, Cooperation:V. Kapoor)

2016-03-05

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; CD4-Positive T-Lymphocytes/immunology/metabolism/*pathology ; CD8-Positive T-Lymphocytes/immunology/pathology ; *Carcinogenesis/immunology/pathology ; Carcinoma, Hepatocellular/*immunology/metabolism/*pathology ; Case-Control Studies ; Choline/metabolism ; Diet ; Disease Models, Animal ; Genes, myc ; Hepatocytes/metabolism/pathology ; Humans ; Linoleic Acid/metabolism ; Lipid Metabolism ; Liver/immunology/pathology ; Liver Neoplasms/*immunology/metabolism/*pathology ; Male ; Methionine/deficiency ; Mice ; Mice, Inbred C57BL ; Mitochondria/metabolism/pathology ; Non-alcoholic Fatty Liver Disease/*immunology/metabolism/pathology ; Oxidative Stress ; Reactive Oxygen Species/metabolism

2011-09-23

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Birds ; Chemoreceptor Cells/cytology/drug effects/*metabolism ; Cues ; Early Growth Response Protein 1/genetics/metabolism ; Female ; Gene Expression Regulation/drug effects ; Male ; Mammals ; Mice ; Pheromones/metabolism/pharmacology ; Predatory Behavior/physiology ; Receptors, Odorant/metabolism ; Sex Characteristics ; Species Specificity ; Vomeronasal Organ/drug effects/*physiology

1089-7550

AIP Digital Archive

Physics

Tl-Ca-Ba-Cu-O high-temperature superconducting thin films were deposited on lanthanum aluminate substrates, by rf magnetron sputtering and postannealing methods. A reproducible fabrication process with low-resistance metal contacts has been established for high-Tc and high-Jc TlCaBaCuO thin films after patterning using standard microelectronic photolithography and wet chemical etching techniques. Low-resistance gold contacts on TlCaBaCuO thin films were obtained by annealing in an oxygen flow of 1 l/min followed by a slow furnace cooling. Specific contact resistivity was approximately 10−10 Ω cm2 below 77 K. High transition temperatures as high as 100 K, and current density at zero magnetic field greater than 105 A/cm2 are routinely obtained in 0.3–0.5 μm TlCaBaCuO thin films. The morphology studies of the films using scanning electron microscopy show the correlation between Jc and the microstructure of the films. Films with featureless morphology have larger zero-field transport currents. The microwave properties of TlCaBaCuO thin films were investigated by designing, fabricating, and characterizing microstrip ring resonators with a fundamental resonance frequency of 12 GHz on 10-mil-thick lanthanum aluminate (LaAlO3) substrates. Ring resonators with a superconducting ground plane of 0.3 μm thickness and a gold ground plane of 1 μm thickness were fabricated and characterized in the temperature range of 60–95 K. Typical unloaded quality factors Q for the ring resonators at 12 GHz were above 1500 at 65 K, compared to an unloaded Q of 370 for a gold ring resonator. A surface resistance as low as 1.5 mΩ at 12 GHz and 77 K was obtained in 0.3 μm TlCaBaCuO thin films using the ring resonator Q measurements. Typical values of penetration depth at 0 K in the TlCaBaCuO thin films were determined to be between 7000 and 8000 A(ring) using the temperature variation of resonance frequency measurements.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

High-temperature superconducing Tl-Ca-Ba-Cu-O (TlCaBaCuO) thin films were fabricated by rf magnetron sputtering on strontium titanate (SrTiO3) substrates. Thin films of 0.5–0.7-μm thickness were deposited by pure argon sputtering from a single composite powder target of Tl2Ca2Ba2Cu3Ox at an rf power of 250 W and a pressure of 5 mTorr. As-deposited thin films were sintered and annealed in a thallium-rich ambient to obtain superconductivity with a zero resistance temperature (Tc0) at 107 K. X-ray diffraction results showed highly c-axis oriented films with Tl2Ca2Ba2Cu3Ox (2223) and Tl2Ca1Ba2Cu2Ox (2122) phases present. Auger electron spectroscopy survey and depth profiles were performed to determine the compositional uniformity and impurity contents of the thin films. X ray photoelectron spectroscopy high-resolution spectra were obtained at the surface, in the bulk, and near the interface with the substrate. Our XPS results support two possible mechanisms for the creation of holes in the TlCaBaCuO compound: (1) partial substitution of Ca2+ for Tl3+ and (2) charge transfer from Tl3+ to the CuO layers resulting in a valence of Tl between +3 and +1 states and the creation of holes in the CuO layers. In addition, a wet chemical etching process was developed for patterning the as-deposited TlCaBaCuO thin films. A 125-μm-wide line was formed using standard photolithography and wet chemical etching which, after heat treatments, showed superconductivity with a Tc0 of 80 K.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Electronic Resource

1077-3118

AIP Digital Archive

Physics

For the first time, fabrication of high-temperature superconducting Tl-Ca-Ba-Cu-O (TlCaBaCuO) thin films on LaAlO3 substrates is reported. TlCaBaCuO thin films were deposited by rf magnetron sputtering of a single composite powder target in a pure argon plasma. The films were sintered in an excess thallium ambient at 850 °C for 15 min followed by a 30 min oxygen annealing at 750 °C. Scanning electron microscopy and x-ray diffraction results showed the smooth and highly c-axis oriented nature of the thin films. The temperature dependence of resistance showed the onset of critical transition temperature (Tc) at 114 K, and zero resistance at 103 K.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Integrated circuit technology has been successfully applied to the design and fabrication of submicron metal-oxide-metal (MOM) tunneling diodes for application in far infrared (FIR) rectennas. The MOM diode and a stripline antenna to enhance collection of FIR radiation were integrated on a silicon substrate using state of the art microelectronic technology and were produced simultaneously. A nickel-oxide-gold MOM tunnel diode was made up of a 0.8-μm-wide nickel layer with approximately 22 A(ring) of a nickel-oxide tunnel barrier layer on top crossed by a 0.8-μm-wide gold layer resulting in a junction area of 0.64 μm2 . The antenna consisted of two 0.8-μm-wide and 6.6-μm-long parallel metal conductors, one nickel and the other gold, separated by a gap of 0.8 μm. The dc current-voltage characteristics of the MOM diode showed that the current dependence on voltage was linear about zero bias up to a bias of about 70 mV. Beyond 70 mV, the characteristics were very nonlinear. The average breakdown field was determined to be 6.6×106 V/cm for nickel-oxide film thicknesses ranging from 15 to 39 A(ring). The current stressing of the MOM diode produced charge trapping within the nickel-oxide layer. The maximum detection of a low level signal (10-mV ac) was determined to be at a dc voltage of 70 mV across the MOM diode using rectifier current sensitivity measurements. The rectified output signal due to a chopped 10.6-μm CO2 laser incident upon the rectenna device was found to increase with dc bias with a maximum value of 1000 nV for a junction bias of 100 mV at room temperature.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Integrated circuit technology has been successfully applied to the design and fabrication of 0.5×0.5-cm planar multijunction solar-cell chips. Each of these solar cells consisted of six voltage-generating unit cells monolithically connected in series and fabricated on a 75-μm-thick, p-type, single crystal, silicon substrate. A contact photolithic process employing five photomask levels together with a standard microelectronics batch-processing technique were used to construct the solar-cell chip. The open-circuit voltage increased rapidly with increasing illumination up to 5 AM1 suns where it began to saturate at the sum of the individual unit-cell voltages at a maximum of 3.0 V. A short-circuit current density per unit cell of 240 mA/cm2 was observed at 10 AM1 suns.

Electronic Resource

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The StatCap semiquantitative carbon dioxide detector was evaluated in an experimental setting. The monitor underread at progressively higher concentrations of carbon dioxide. During simulated rebreathing, progressive increases in inspired carbon dioxide resulted in the StatCap readings decreasing. It is recommended that the StatCap be used with caution in circumstances where rebreathing may occur, for example, during manual ventilation with an Ayre's T-piece.

Electronic Resource

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. Neuropeptide Y (NPY) is colocalised with noradrenaline in post-ganglionic sympathetic neurons. In order to examine the possibility that activation of the sympathetic nervous system might cause release of NPY into the plasma NPY levels were measured in 16 patients undergoing exercise tests for investigation of chest pain.2. Plasma NPY concentrations rose in 14 out of the 16 patients, and the mean level of plasma NPY increased from 335 (s.e.m. = 37) to 455 (s.e.m. = 41) pg/ml.3. Plasma noradrenaline and adrenaline levels increased four- and two-fold respectively.4. The increase in NPY correlated with the increase in noradrenaline, suggesting that NPY may be released with noradrenaline when sympathetic noradrenergic nerves are activated.

Electronic Resource

0304-4165

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0022-3697

EPR ; Mn^2^+ ; Superposition model ; zero-field splitting

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0022-1902

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Energy, Environment Protection, Nuclear Power Engineering

Electronic Resource

0167-8760

Attention ; Autism ; Dopamine ; Event-related potential ; Fenfluramine ; Homovanillic acid ; Noradrenaline ; Serotonin

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Psychology

Electronic Resource

0304-4165

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1436-2813

portal hypertension ; non-cirrhotic portal fibrosis ; splenomegaly ; splenorenal shunt ; caesarean section ; pregnancy

Springer Online Journal Archives 1860-2000

Medicine

Abstract A case of portal hypertension due to non-cirrhotic portal fibrosis in a pregnant woman is reported. The patient had a massive splenomegaly and hypersplenism. In anticipation of problems associated with portal hypertension in pregnancy, prophylactic splenorenal shunt was performed during the second trimester. The pregnancy progressed uneventfully until the 39th week when Caesarean section had to be performed for foetal distress. A healthy male child was delivered.

Electronic Resource

1432-2323

Springer Online Journal Archives 1860-2000

Medicine

Résumé Il est toujours possible de devoir convertir la cholécystectomie laparoscopique en cholécystectomie traditionnelle. Le but de cette étude a été de déterminer les facteurs prédictifs de conversion. Entre Octobre 1992-Avril 1994, 29 de 150 cholécystectomies par voie laparoscopique (19%) ont nécessité une conversion. Dix facteurs préopératoires ont été analysés rétrospectivement pour identifier des paramètres qui corrélaient de façon significative avec une conversion. Ces facteurs étaient l'âge, le sexe, la durée des symptômes, l'indexe de masse corporelle (BMI), une histoire d'ictère, une chirurgie abdominale antérieure, des facteurs médicaux associés, une masse palpable, les données de l'échographie et de la cholécystographie orale. Par analyse monofactorielle et régression multiple on a identifié les facteurs prédictifs de conversion suivants: le sexe masculin, les donnécs échographies montrant un épaississement de la paroi vésiculaire/contractée et one masse vésiculaire palpable.

Resumen La posibilidad de conversión a colecistectomía abierta (CA) stempre existe en el curso de una colecistectomía laparoscópica (CL). El presente estudio ha sido realizado con el objeto de identificar los factores que permitan predecir la conversión a CA. En el período octubre 1992-abril 1994, se intentó CL en 150 pacientes y se requirió conversión a CA en 29 (19%). Diez factores preoperatorios fueron analizados retrospectivamente para identificar parámetros de correlación significativa de conversión a CA. Los factores preoperatorios analizados fueron edad, sexo, duración de los síntomas, índice de masa corporal, historia de ictericia, cirugía abdominal previa, factores médicos de riesgo asociados, masa palpable en el examen clínico y hallazgos USG y OCG. El análisis univariable y de regresión múltiple identificó el sexo masculino, el hallazgo USG de una vesícula biliar contraida de paredes gruesas y una vesícula biliar palpable en el examen como factores preoperatorios significativos de predicción de conversión a CA.

Abstract The possibility of conversion to open cholecystectomy (OC) always exists while performing a laparoscopic cholecystectomy (LC). This study has been performed with the aim of identifying factors predicting conversion to OC. From October 1992-April 1994, LC was attempted in 150 patients and conversion to OC was required in 29 (19%) patients. Ten preoperative factors were analyzed retrospectively to identify parameters significantly correlating with conversion to OC. Preoperative factors analyzed were age, sex, duration of symptoms, BMI (Body Mass Index), past history of jaundice, previous abdominal surgery, associated medical risk factors, palpable lump on clinical examination, USG, and OCG findings. Univariate and multiple stepwise regression analysis identified male sex, USG finding of contracted/thick-walled gall bladder, and a palpable gall bladder lump on examination as significant preoperative factors predicting conversion to OC.

Electronic Resource