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101.
Karthik H. Shankar 《General Relativity and Gravitation》2017,49(2):33
Gravitational collapse singularities are undesirable, yet inevitable to a large extent in General Relativity. When matter satisfying null energy condition (NEC) collapses to the extent a closed trapped surface is formed, a singularity is inevitable according to Penrose’s singularity theorem. Since positive mass vacuum solutions are generally black holes with trapped surfaces inside the event horizon, matter cannot collapse to an arbitrarily small size without generating a singularity. However, in modified theories of gravity where positive mass vacuum solutions are naked singularities with no trapped surfaces, it is reasonable to expect that matter can collapse to an arbitrarily small size without generating a singularity. Here we examine this possibility in the context of a modified theory of gravity with torsion in an extra dimension. We study singularity-free static shell solutions to evaluate the validity of NEC on the shell. We find that with sufficiently high pressure, matter can be collapsed to arbitrarily small size without violating NEC and without producing a singularity. 相似文献
102.
103.
104.
D. Karthik S. Ilavenil B. Kaleeswaran S. Sunil S. Ravikumar 《Applied biochemistry and biotechnology》2012,166(6):1507-1519
Despite tremendous advances in our understanding of the molecular basis of diabetes mellitus, substantial gaps still remain in our understanding of disease pathogenesis and in the development of effective strategies for early diagnosis and treatment. The proteomic approach has offered many opportunities and challenges in identifying new marker proteins and therapeutic targets, i.e., using 2D-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry. The differential protein expressions were analyzed in alloxan-induced diabetic rats treated with Cynodon dactylon leaf extract. The plant extract was administered for 15 days that resulted in a significant increase in plasma insulin and C-peptide levels. We have also identified four differentially expressed proteins from rat plasma. These four diabetes-associated proteins were broadly classified into three groups as per their function: (1) lipid metabolism-associated protein (Apo A-IV), (2) antioxidant activity-related proteins [preprohaptoglobin and heat shock proteins B8 (HspB8)], and (3) muscle function-related protein (TPM3). Apo A-IV, HspB8, and preprohaptoglobin may play a key role in the recovery of diabetes mellitus and also prevent the diabetes-associated complications such as prevention of oxidative stress due to free radical and free hemoglobin. These results show the value of proteomic approach in identifying the potential markers that may eventually serve as diagnostic markers or therapeutic targets. 相似文献
105.
Abstract–An extremely weak native light emission from rat liver nuclei was detected and studied using a highly sensitive single photon counting system. This emission is oxygen dependent and we attribute it to (per) oxidative processes. The effects of deuterium oxide and l,4-diazabicyclo-[2.2.2] octane on the light emission suggests the possible involvement of singlet oxygen. The kinetic features of the underlying reactions including biphasic response to both oxygen and temperature changes, could be clearly discerned. Further study of this light emission can serve as a useful adjunct to biochemical investigations of oxidative processes which play an important role in mutation, carcinogenesis and aging. 相似文献
106.
Adéla?Zemanová Olga?Semenova Ale??Kroupa Jan?V?e?t’álEmail author Karthik?Chandrasekaran Klaus W.?Richter Herbert?Ipser 《Monatshefte für Chemie / Chemical Monthly》2005,136(11):1931-1937
Summary. Phase equilibria in the Ag–In–Pd system were determined at 700°C based on experimental results for 21 alloys. A ternary compound
T1 (with the approximate composition AgInPd2) was identified by XRD analysis. These data were compared with the results of a CALPHAD-type prediction, based on binary
thermodynamic data only and a symmetrical Redlich–Kister–Muggianu model. The experimental results will serve as a basis for refined thermodynamic modeling of the different phases in this
ternary system. 相似文献
107.
G. N. K. Ramesh Bapu G. Devaraj J. Ayyapparaj 《Journal of Solid State Electrochemistry》1998,3(1):48-51
An alkaline non-cyanide zinc plating solution consisting of 10 g/l zinc oxide, 90 g/l sodium hydroxide and 1.5 g/l gelatine
was prepared . Using this solution, a smooth, uniform and fine-grained semi-bright deposit was obtained on mild steel sheets
over a wide range of current density and pH at 303 K. The plating bath had about 63% current efficiency and 25% throwing power
at 303 K and at pH 10. Caffeine and vanillin additions to this bath gave bright zinc deposits.
Received: 30 January 1998 / Accepted: 15 May 1998 相似文献
108.
A weighted norm inequality involving A1 weights is obtained at the natural exponent for gradients of solutions to quasilinear elliptic equations in Reifenberg flat domains. Certain gradient estimates in Lorentz–Morrey spaces below the natural exponent are also obtained as a consequence of our analysis. 相似文献
109.
Polymer containing chalcone moiety showed a cis–trans isomerism. Two novel acrylate monomers, 4‐[3‐(2,4‐dichloro‐phenyl)3‐oxoprop‐1‐en‐1‐yl]phenylacrylate (DCP) and 4‐(3‐(4‐((4‐(4‐(3‐(2,4‐dichlorophenyl)‐3‐oxoprop‐1‐en‐1‐yl)phenoxy)‐6‐((4‐nitrophenyl)amino)‐1,3,5‐triazin‐2‐yl)oxy)phenyl)‐3‐oxoprop‐1‐en‐1‐yl)phenyl acrylate (TCP) were synthesized and copolymer with acrylic acid. All the monomers and polymer were characterized by IR, NMR and UV techniques. The Mw of the DCP based polymer and TCP based polymer were 4000 and 10,000 g/mol respectively. DCP and TCP based polymer showed double stage and single stage decomposition respectively. The reactivity ratio of the polymers showed that the poly(DCP‐co‐AA) formed random polymerization whereas poly(TCP‐co‐AA) formed alternate copolymerization. The poly(TCP‐co‐AA) showed excellent photoisomerism whereas poly(DCP‐co‐AA) showed photocycloaddition reaction. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
110.
Stewart MJ Jothivasan VK Rowan AS Wagg J Hamilton CJ 《Organic & biomolecular chemistry》2008,6(2):385-390
A solid phase synthesis of des-myo-inositol mycothiol disulfide and its alpha-configured methyl- and benzyl-glycoside derivatives has been developed. Kinetic characterisation of these compounds has demonstrated their viability as alternative substrates for use in mycothiol disulfide reductase enzyme assays. 相似文献