RESUMO
In this paper, we report the synthesis of highly conducting phosphorous doped hydrogenated nanocrystalline silicon (nc-Si:H) films at substantially low substrate temperature (200 degrees C) by hot-wire chemical vapor deposition (HW-CVD) method using pure silane (SiH4) and phosphine (PH3) gas mixture without hydrogen dilution. Structural, optical and electrical properties of these films were investigated as a function of PH3 gas-phase ratio. The characterization of these films by low-angle X-ray diffraction, Raman spectroscopy and atomic force microscopy revealed that, the incorporation of phosphorous in nc-Si:H induces an amorphization in the nc-Si:H film structure. Fourier transform infrared spectroscopy analysis indicates that hydrogen predominately incorporated in phosphorous doped n-type nc-Si:H films mainly in di-hydrogen species (Si-H2) and poly-hydrogen (Si-H2)n bonded species signifying that the films become porous, and micro-void rich. We have observed high band gap (1.97-2.37 eV) in the films, though the hydrogen content is low (< 1.4 at.%) over the entire range of PH3 gas-phase ratio studied. Under the optimum deposition conditions, phosphorous doped nc-Si:H films with high dark conductivity (sigma Dark -5.3 S/cm), low charge-carrier activation energy (E(act) - 132 meV) and high band gap (- 2.01 eV), low hydrogen content (- 0.74 at.%) were obtained at high deposition rate (12.9 angstroms/s).
Assuntos
Cristalização/métodos , Gases/química , Membranas Artificiais , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Fósforo/química , Silício/química , Condutividade Elétrica , Temperatura Alta , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
An investigative study was carried out in 340 cases of established pulmonary and presumed pleural tuberculosis for co-occurrence of HIV-1 infection in them. Confirmatory screening for HIV-1 was carried out with both ELISA (Vironostika) and Serodia commercial kits in all reactive samples on first screening. In all, 16 cases proved to be having HIV-1 coexistent infection with pulmonary tuberculosis. Their preliminary vital clinical observations and roentogenic finding are summarized and literature reviewed briefly.
PIP: In Marathwada region of Maharashtra State, India, clinicians obtained blood samples from 340 pulmonary and presumed pleural tuberculosis (TB) patients at the TB Wing of the Government Medical College Hospital in Aurangabad to determine the HIV seropositivity rate of the cases. All samples testing positive for an ELISA would undergo another ELISA to confirm the first ELISA's results. The ELISA commercial kits were Serodia and Vironostika. 16 cases tested positive for HIV by both ELISA tests. The sexual preference of all 16 cases was heterosexual. Males and 20-39 year olds were the predominant groups (12 vs. 4 for both groups). No case was younger than 20 years old. Six HIV-positive male TB patients had had multiple partners. Three of them also had genital ulcer disease, a cofactor facilitating HIV transmission. Six HIV-positive TB patients had a history of receiving streptomycin injections and 2 of them had also had multiple partners. 25% of HIV-positive TB patients had pleural effusion. 12 cases had TB clinical features (lower zone infiltration, hilar/mediastinal adenopathy, and diffuse infiltration without cavitation) associated with greater impairment of cell mediated immunity.
Assuntos
Soropositividade para HIV/epidemiologia , HIV-1/imunologia , Tuberculose Pulmonar/epidemiologia , Adulto , Distribuição por Idade , Feminino , Soropositividade para HIV/complicações , Soropositividade para HIV/patologia , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/patologiaRESUMO
Enzymology is a diagnostic indicator for myocardial infarction and diabetes in hypertension patients. Therefore the selection of methods for measurement of cardiac enzyme, Aspartate transaminase (AST), Creatine kinase(CK), and isoenzyme of creatine kinase (MB form), determine the effectiveness of antihypertension drug would provide the physician with diagnostic and prognostic clinical evidence.