Search Results - (Author, Cooperation:R. Mehra)

2018-01-16

Wiley-Blackwell

1388-9842

1879-0844

Medicine

2018-05-15

American Heart Association (AHA)

1524-4539

Medicine

Statements and Guidelines

2012-06-23

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Cell Proliferation ; Cells, Cultured ; Hepatocyte Nuclear Factor 3-alpha/genetics ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Orchiectomy ; Prostatic Neoplasms/*genetics/pathology ; Receptors, Androgen/metabolism ; Sequence Alignment ; Signal Transduction

2018-11-16

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1089-7550

AIP Digital Archive

Physics

Highly conducting and transparent aluminum-doped zinc oxide films were prepared on quartz and corning glass 7059 substrate by ablating the sintered ZnO target containing 2 wt % Al2O3 with a XeCl excimer laser (λ=308 nm). To grow the films, a repetition rate of 5 Hz and energy density of 1.5 J/cm2 was kept. The effect of substrate temperature from room temperature to 400 °C and oxygen pressure (0.1–5 mTorr) have been investigated by analyzing the optical and electrical properties of these films. The average transmittance was found to be in the range of 86%–92%, and a variable resistivity (ρ) 3.56×10−3–7.0×10−3 Ω cm have been obtained. The lowest resistivity was found to be 1.4×10−4 Ω cm at 300 °C in 1 mTorr of oxygen pressure. Structural changes in the films were also investigated by determining the full width at half maximum of (002) x-ray diffraction peak. These results show improvement in the crystallinity of films, which support our conductivity and transmittance data. The sharp decrease in the transmittance or sharp increase in reflectance near the plasma edge in the near-infrared range has been attributed to impurity scattering, which is Al doping in our films. © 2001 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

This paper reports on the p to n transition in Pb doped Se–In chalcogenide glasses. Measurements of thermoelectric power in the temperature range 300 K≤T≤315 K, dc conductivity in the temperature range 100≤T≤300 K, and optical band gap (Egopt) have been carried out for Se75In25−xPbx (x=0,5,10,15) samples. The p-n transition occurs with very low addition of Pb impurity (5 at. %). The conductivity and pre-exponential factor also change by five to six orders of magnitude with Pb doping. Results are explained on the basis of the formation of ionic Pb–Se bonds, instead of covalent bonds. Formation of ionic bonds disturbs the equilibrium between the charged defect states of Se–In glass and unpins the Fermi level and thus leads to n-type conduction in these glasses. © 1997 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The effect of In impurity on the dark and photoconductivity and the optical band gap of amorphous (Se0.7Te0.3)100−xInx has been studied. The activation energy ΔE and the pre-exponential factor σ0(0,T) which appear in the dc conductivity are found to increase with increasing In content. The photocurrent, as a function of illumination intensity and time of illumination, has been measured at around room temperature. The bimolecular recombination mechanism is found to be predominant at steady state in all the samples near room temperature. The nonexponential decay, after stopping the illumination, has been explained in terms of localized-localized recombination. The data have been analyzed in terms of the dispersive diffusion controlled recombination and monomolecular recombination is found to be dominant in the transient state. The optical band gap is found to decrease with increasing In content. This decrease has been explained on the basis of metallic bonding due to incorporation of In.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Thermoelectric power measurements have been made on macroporous (pore width 〉500 Å°) porous silicon samples prepared by an anodic dissolution technique. The sign of thermopower is found to be negative indicating that conduction takes place due to electrons in the conduction band. The conduction mechanism is found to be due to variable range hopping near the Fermi level for temperatures below 150 K. At higher temperatures the conduction is due to the tunneling of carriers in the localized states in the band edges. It was concluded that these localized states are formed because the nanocrystallites in porous silicon are randomly distributed in size and orientation leading to fluctuations in band gap. This results in the constitution of a disordered system on a macroscopic scale. © 1998 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The results of a combined study of the temperature variation of photoluminescence (PL) and dc conductivity from high optical-quality free-standing porous silicon films are presented. PL spectra of the samples have been studied in the range 10–300 K. Dc conductivity (σ) on these samples have been studied from 90 to 300 K in the voltage range 0.25–1.5 V. We attempt to understand the luminescence and transport data in terms of a recently proposed unified model. The conductivity (σ) exhibits a Berthlot-type temperature variation [≅exp(T/TB)]. The luminescence data can be explained in terms of a competition between an activated radiative process [≅ exp−(Tr/T)] and a Berthlot-type hopping process. The Berthlot temperature "TB" obtained independently from the transport and luminescence data are in approximate agreement. © 1998 American Institute of Physics.

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The results for the ac conductivity over temperature range (298–500 K) and frequency range (102–107 Hz) for the Ge-Sb-Se glasses with different compositions are presented. These glasses exhibit a strong temperature dependence of ac conductivity and of its frequency exponent s. The results are discussed in the light of the correlated barrier hopping model for ac conduction. All the features observed are interpreted by taking into account the contribution of both single polarons and bipolarons. It is shown that the single polarons dominate the hopping transport process in the measured temperature range. The effect of the addition of Sb is also discussed in terms of the present model. The energy levels and densities of the defect for Ge-Sb-Se glasses are deduced from the comparison between the theoretical and experimental results.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Evidence is presented for the potentiating role of corticosterone on axonal degeneration of serotonergic neurones during ageing. Aged rats, 24 months old, were implanted subcutaneously with 2 × 100 mg pellets of corticosterone. Serotonergic and cholinergic (ChAT- and NADPHd-positive) fibre degenerations in the anteroventral thalamic nucleus (AVT) were measured 2 months after corticosterone implantation. Numbers of immunoreactive serotonergic raphe and mesolimbic cholinergic neurones were also quantified. Basal plasma corticosterone and adrenocorticotropin (ACTH) concentrations were assayed at 2, 4, 6, and 8 weeks after implantation in the plasma and at 1, 2, 4 and 6 weeks in urine. The degree of serotonergic fibre aberrations in the AVT increased significantly after corticosterone exposure, while that of ChAT-positive and NADPHd-stained axon aberrations showed a modest but nonsignificant increase. A positive correlation between the magnitudes of serotonergic and cholinergic fibre aberrations appeared in the AVT, but only in the corticosterone-treated rats. The number of serotonin immunopositive neurones in the raphe nuclei after corticosterone decreased marginally, while that of mesopontine ChAT-positive neurones was not influenced. Measurements of basal plasma corticosterone and ACTH, as well as urine corticosterone, revealed that the steroid implantation increased the plasma corticosterone level for at least 4 weeks and decreased ACTH level for at least 6 weeks. By the week 8, the pituitary-adrenal function was apparently restored. However, at sacrifice, both the weight of adrenal glands and that of thymus remained reduced, indicating the long-lasting effects of corticosterone on target tissues. It is concluded that the raphe serotonergic neurones and their projecting fibres are sensitive to corticosterone excess in aged rats and become more vulnerable to degeneration processes than under normal ageing conditions. Cholinergic neurones of brainstem origin, which also express massive NADPHd activity, are more resistant against corticosterone, but their axon degeneration correlates to serotonergic fibre degeneration.

Electronic Resource

1365-2842

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

summary It is necessary to visualize and reconstruct tissue anatomic surfaces accurately for a variety of oral rehabilitation applications such as surface wear characterization and automated fabrication of dental restorations, accuracy of reproduction of impression and die materials, etc. In this investigation, a 3-D digitization and computer-graphic system was developed for surface characterization. The hardware consists of a profiler assembly for digitization in an MTS biomechanical test system with an artificial mouth, an IBM PS/2 computer model 70 for data processing and a Hewlett-Packard laser printer for hardcopy outputs. The software used includes a commercially available Surfer 3-D graphics package, a public domain data-fitting alignment software and an inhouse Pascal program for intercommunication plus some other limited tasks. Surfaces were digitized before and after rotation by angular displacement, the digital data were interpolated by Surfer to provide a data grid and the surfaces were computer graphically reconstructed: Misaligned surfaces were aligned by the data-fitting alignment software under different choices of parameters. The effect of different interpolation parameters (e.g. grid size, method of interpolation) and extent of rotation on the alignment accuracy was determined. The results indicate that improved alignment accuracy results from optimization of interpolation parameters and minimization of the initial misorientation between the digitized surfaces. The method provides important advantages for surface reconstruction and visualization, such as overlay of sequentially generated surfaces and accurate alignment of pairs of surfaces with small misalignment.

Electronic Resource

0304-3932

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Economics

Electronic Resource

0014-2921

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Economics

Electronic Resource

0022-0531

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Economics

Electronic Resource

0040-4020

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0304-3932

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Economics

Electronic Resource

1569-8041

allogeneic transplantation ; BEAM ; lymphoma

Springer Online Journal Archives 1860-2000

Medicine

Abstract Background: The combination of carmustine, etoposide, cytarabine and melphalan (BEAM) is an effective autologous transplantation preparative regimen for lymphoma and has little toxicity, but the feasibility and tolerance of BEAM as a preparative regimen for allogeneic transplantation has not been established. Patients and methods: Thirty adults with primary refractory or recurrent intermediate- or low-grade lymphoma were treated on a prospective phase II study with carmustine 300 mg/m2 i.v. day −6, etoposide 200 mg/m2 i.v. followed by cytarabine 200 mg/m2 i.v. twice daily days −5 to −2, melphalan 140 mg/m2 i.v. day −1, and marrow or blood stem cells from an HLA-identical donor on day 0. Tacrolimus and methotrexate were used to prevent graft-vs.-host disease (GVHD). Results: Median time from transplantation was 20 mos (range 6–32 months). Median maximal regimen-related toxicity grade was 2, and four patients (13%) had a grade 3–4 regimen-related toxicity. Two patients had idiopathic interstitial pneumonitis. One patient had primary graft failure, and a second had autologous reconstitution documented at three months posttransplant. Grades 2–4 acute GVHD occurred in 31%, grades 3–4 in 16%, and chronic GVHD in 54%. Day-100 survival was 70%. Twenty-three patients achieved a complete response. The two-year relapse rate was 23%, survival was 48%, and disease-free survival (DFS) was 42%. Conclusions: BEAM supports engraftment of allogeneic transplants and is a tolerable preparative regimen for allogeneic transplantation for lymphoma.

Electronic Resource