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排序方式: 共有299条查询结果,搜索用时 15 毫秒
1.
The proteolytic activity produced by a Bacillus subtilis isolated from a hot spring was investigated. Maximum protease production was obtained after 38 h of fermentation. Effects of various carbon and nitrogen sources indicate the requirement of starch and bacteriological peptone to be the best inducers for maximum protease production. Requirement for phosphorus was very evident, and the protease was secreted over a wide range of pH 5-11. The partially purified enzyme was stable at 60 degrees C for 30 min. Calcium ions were effective in stabilizing the enzyme, especially at higher temperature. The enzyme was extremely salt tolerant and retained 100% activity in 5M NaCl over 96 h. The molecular weight of the purified enzymes as determined by SDS-PAGE was 28,000. The enzyme was completely inactivated by PMSF, but little affected by urea, sodium dodecyl sulfate, and sodium tripoly phosphate. 相似文献
2.
Bipolar illness may be characterized by dysregulation and dysfunction of biologically active ions and ion pumps, respectively. In an effort to examine whether purported physiologic abnormalities may have functional counterparts, nerve conduction velocities (NCVs) and H-reflex recovery were examined in 7 acutely manic, 11 euthymic bipolar, 13 remitted schizophrenic, and 6 normal control individuals. All electrophysiologic tests were clinically normal. However, euthymic bipolar patients had significantly slower NCVs than either manic or normal individuals. Percent decrement of H-reflex recovery was nonsignificantly increased in manic versus euthymic bipolar subjects. Data analysis suggests lithium was not responsible for these changes. These data indicate that different mood states in bipolar illness are associated with alterations in electroneurophysiologic function. 相似文献
3.
S.K. Marik D.V.H. Rao A. Bhatnagar R.C. Pant A.C. Tikku S. Sankar 《Nuclear Engineering and Design》2006,236(7-8):730-746
Cirus, a 40 MW t, vertical tank type research reactor, having wide range of research facilities, was commissioned in the year 1960. This research reactor, situated at Mumbai, India has been operated and utilized extensively for isotope production, material testing and neutron beam research for nearly four decades. With a view to assess the residual life of the reactor, detailed ageing studies were carried out during the early 1990s. Based on these studies, refurbishment of Cirus for its life extension was taken up. During refurbishment, additional safety features were incorporated in various systems to qualify them for the current safety standards. This paper gives the details of the operating experiences, utilization of the reactor along with methodologies followed for carrying out detailed ageing studies, refurbishment and safety upgradation for its life extension. 相似文献
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5.
C. -X. Ji Peter F. Ladwig Ronald D. Ott Y. Yang Joshua J. Yang Y. Austin Chang Eric S. Linville Jenny Gao Bharat B. Pant 《JOM Journal of the Minerals, Metals and Materials Society》2006,58(6):50-54
Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive
spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a
paramagnetic state rather than an antiferromagnetic phase with L10 structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation
from the asdeposited A1 face-centered-cubic phase to the antiferromagnetic L10 phase. The A1 to L10 metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation
enthalpy of −12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami
analysis. 相似文献
6.
Hongjun Song Jenna M. Rosano Yi Wang Charles J. Garson Balabhaskar Prabhakarpandian Kapil Pant George J. Klarmann Luis M. Alvarez Eva Lai 《Microfluidics and nanofluidics》2017,21(4):64
Stem cell enrichment plays a critical role in both research and clinical applications. The typical method for stem cell enrichment may use invasive processes and takes a long period of time. Spiral-shaped microfluidic devices, which combine lift and Dean drag forces to direct cells of different sizes into separate trajectories, can be used to noninvasively process samples at a rate of milliliters per minute. This paper presents a simple 2-loop spiral-shaped inertial microfluidic devices with the aid of sheath flow to enrich neural stem cells (NSCs), derived from induced pluripotent stem cells. NSCs and spontaneously differentiated non-neural cells were mixed and flowed through the spiral-shaped devices. Samples collected at the outlets were analyzed for purity and recovery. It was found that the device focused the NSCs into a narrow trajectory, which could then be collected in two out of the eight outlets. The device was tested at different flow rates and found that the most highly enriched fractions (2.1×) with NSCs recovery 93% were achieved at the flow rate (3 ml/min). Next, we extended our investigation from 2-loop design to 10-loop design to eliminate the use of sheath flow. NSCs were enriched to 2.5×, but only 38% of the NSCs were recovered from the most enriched fractions. Spiral-shaped microfluidic devices are capable of rapid, label-free enrichment of target stem cells, and have great potential in point-of-care tissue preparation. 相似文献
7.
Gaurang Pant Prakaipetch Punchaipetch M. J. Kim Robert M. Wallace Bruce E. Gnade 《Thin solid films》2004,460(1-2):242-246
Physical and electrical properties of hafnium silicon oxynitride (HfSixOyNz) dielectric films prepared by UV ozone oxidation of hafnium silicon nitride (HfSiN) followed by annealing to 450 °C are reported. Interfacial layer growth was minimized through room temperature deposition and subsequent ultraviolet/ozone oxidation. The capacitance–voltage (C–V) and current–voltage (I–V) characteristics of the as-deposited and annealed HfSixOyNz are presented. These 4 nm thick films have a dielectric constant of 8–9 with 12 at.% Hf composition, with a leakage current density of 3×10−5 A/cm2 at Vfb+1 V. The films have a breakdown field strength >10 MV/cm. 相似文献
8.
Cheng-Wei Lu Jing Fu Xiu-Fen Liu Wei-Wei Chen Ji-Long Hao Xiao-Lan Li Om Prakash Pant 《光:科学与应用(英文版)》2021,(11):2128-2142
This study is the first to explore the potential associations among allergic conjunctivitis (AC), air pollution, and meteorological conditions in Northeast Chin... 相似文献
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10.
B. K. Pant Vivek Arya B. S. Mann 《Journal of Materials Engineering and Performance》2012,21(6):1051-1055
This article deals with plasma ion-nitrocarburising and high power diode laser (HPDL) surface treatment of 13Cr4Ni and X10CrNiMoV1222 martensitic stainless steels to enhance their cavitation erosion resistance. These steels are commonly used in hydro turbines and boiler feed pumps. These treated steels have been evaluated for cavitation erosion resistance and it has been observed that the plasma ion-nitrocarburising process has significantly enhanced the cavitation erosion resistance as compared to untreated steel whereas HPDL-treated steels have shown marginal improvement. This is due to formation of high hardness nitrides during nitrocarburising and formation of moderate hardness martensitic phase due to rapid heating and cooling rates involved in HPDL treatment. The cavitation erosion and micro-hardness data of plasma ion-nitrocarburized as well as HPDL-treated steel samples and their comparison with hard deposits such as stellite and HVOF coating form the main part of the article. 相似文献