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Acta Pharmaceutica Sinica B 2016年第6期6卷 600-613页

作者： vijay sharma Kamla Pathak Department of Pharmaceutics Rajiv Academy for Pharmacy

The present research aimed to improve the dissolution rate and bioavailability of curcumin using the potential of liquisolid technology. Twelve drug-loaded liquisolid systems (LS-1 to LS-12) were prepared using different vehicles (PEG 200, PEG 400 and Tween 80) and curcumin concentrations in vehicle (40%, 50%, 60% and 70%, w/w). The carrier [microcrystalline cellulose (MCC) PH102] to coat (Aerosil®) ratio was 20 in all formulations. The systems were screened for pre-compression properties before being compressed to liquisolid tablets (LT-1 to LT-12). Post compression tests and in vitro dissolution of LTs were conducted and the results compared with those obtained for a directly compressed tablet (DCT) made of curcumin, MCC PH102 and Aerosil®. LTs exhibited higher cumulative drug release (CDR) than the DCT and the optimum formulation, LT-9 (made using Tween 80), was studied by powder XRD, DSC, SEM and FTIR. Ex-vivo permeation of curcumin from LT-9 through goat gastrointestinal mucosa was significantly (P50) of LT-9 towards NCL 87 cancer cells was 40.2 µmol/L substantiating its anticancer efficacy. Accelerated stability studies revealed insignificant effects of temperature and humidity on LT-9. In summary, solubility enhancement of curcumin in LTs produced significant improvements in its permeation and bioavailability.

关键词： Liquisolid tablet Powder solution technology Curcumin Hydrogen bond formation Cytotoxicity Gastric permeation Bioavailability Pharmacokinetics

VLSI scaling methods and low power CMOS buffer circuit

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Journal of Semiconductors 2013年第9期34卷 92-99页

作者： vijay Kumar sharma Manisha Pattanaik Department of Information Technology ABV-Indian Institute of Information Technology & Management

Device scaling is an important part of the very large scale integration （VLSI） design to boost up the success path of VLSI industry, which results in denser and faster integration of the devices. As technology node moves towards the very deep submicron region, leakage current and circuit reliability become the key issues. Both are increasing with the new technology generation and affecting the performance of the overall logic circuit. The VLSI designers must keep the balance in power dissipation and the circuit＇s performance with scaling of the devices. In this paper, different scaling methods are studied first. These scaling methods are used to identify the effects of those scaling methods on the power dissipation and propagation delay of the CMOS buffer circuit. For mitigating the power dissipation in scaled devices, we have proposed a reliable leakage reduction low power transmission gate （LPTG） approach and tested it on complementary metal oxide semiconductor （CMOS） buffer circuit. All simulation results are taken on HSPICE tool with Berkeley predictive technology model （BPTM） BSIM4 bulk CMOS files. The LPTG CMOS buffer reduces 95.16% power dissipation with 84.20% improvement in figure of merit at 32 nm technology node. Various process, voltage and temperature variations are analyzed for proving the robustness of the proposed approach. Leakage current uncertainty decreases from 0.91 to 0.43 in the CMOS buffer circuit that causes large circuit reliability.

关键词： LPTG buffer power dissipation propagation delay scaling nanoscale CMOS figure of merit

Codimension-2 bifurcation in a discrete predator-prey system with constant yield predator harvesting

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International Journal of Biomathematics 2023年第5期16卷 165-191页

作者： Anuraj Singh vijay Shankar sharma ABV-Indian Institute of Information Technology and Management Gwalior Madhya PradeshIndia

This work investigates the bifurcation analysis in a discrete-time Leslie-Gower predatorprey model with constant yield predator *** stability analysis for the fixed points of the discretized model is shown *** this study,the model undergoes codimension-1 bifurcation such as fold bifurcation(limit point),flip bifurcation(perioddoubling)and Neimark-Sacker bifurcation at a positive fixed ***,the model exhibits codimension-2 bifurcations,including Bogdanov-Takens bifurcation and generalized fip bifurcation at the fixed *** each bifurcation,by using the critical normal form coefficient method,various critical states are *** validate our analytical findings,the bifurcation curves of fixed points are drawn by using *** system exhibits interesting rich dynamics including limit cycles and ***,it has been shown that the predator harvesting may control the chaos in the system.

关键词： Flip bifurcation Neimark-Sacker bifurcation generalized fip bifurcation Bogdanov-Takens bifurcation harvesting

Inclusion of Finite Permeability on Design and Optimization of an Electromagnetic Undulator

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Chinese Physics Letters 2014年第3期31卷 55-57页

作者： vijay Huse Geetanjali sharma Swati Mishra G. Mishra School of Physics Devi Ahilya University Indore 452001 (M.P.) India

We derive an alternate analytical expression for the optimum dimensions of an electromagnetic undulator with a finite permeability lamination core. The analytical expressions are compared with earlier results under an... 详细信息

关键词： Laminating

DWT-SVD Based Image Steganography Using Threshold Value Encryption Method

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Computers, Materials & Continua 2022年第8期72卷 3299-3312页

作者： Jyoti Khandelwal vijay Kumar sharma Dilbag Singh Atef Zaguia School of Computing and Information Technology(SCIT) Manipal University JaipurJaipur302004India School of Electrical Engineering and Computer Science Gwangju Institute of Science and TechnologyGwangju61005Korea Department of Computer Science College of Computers and Information Technology Taif University11099Saudi Arabia

Digital image steganography technique based on hiding the secret data behind of cover image in such a way that it is not detected by the human visual *** paper presents an image scrambling method that is very useful for grayscale secret *** this method,the secret image decomposes in three parts based on the pixel’s threshold *** division of the color image into three parts is very easy based on the color channel but in the grayscale image,it is difficult to *** proposed image scrambling method is implemented in image steganography using discrete wavelet transform(DWT),singular value decomposition(SVD),and sorting *** is no visual difference between the stego image and the cover *** extracted secret image is also similar to the original secret *** proposed algorithm outcome is compared with the existed image steganography *** comparative results show the strength of the proposed technique.

关键词： Image steganography threshold value sorting discrete wave transformation singular value decomposition color band division permutation

Improved thermoelectric property of cation-substituted CaMnO_3

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Chinese Physics B 2015年第9期24卷 542-547页

作者： Pradeep Kumar Subhash C.Kashyap vijay Kumar sharma H.C.Gupta Department of Physics Shyam Lal CollegeUniversity of Delhi Department of Physics Indian Institute of Technology Delhi

Single-phase pristine and cation-substituted calcium manganite（Ca1-xBixMn1-yVyO3-δ） polycrystalline samples were synthesized by the solid state reaction technique. Their thermoelectric properties were measured by a set up that was designed and assembled in the laboratory. The Ca1-x BixMn1-yVyO3-δsample with x = y = 0.04 has shown a power factor（S^2σ） of 176 μW/m/K^2 at 423 K, which is nearly two orders of magnitude higher than that of the pristine sample（2.1 μW/m/K2）. The power factor of the substituted oxide remains almost temperature independent as the Seebeck coefficient increases monotonically with temperature, along with the simultaneous decrease in electrical resistivity which is attributed to enhanced electron density due to co-doping of bismuth and vanadium and grain boundary scattering. These cation-substituted calcium manganites can be used as a potential candidate for an n-type leg in a thermoelectric generator（module）.

关键词： thermoelectric materials solid state reaction Seebeck coefficient power factor

Extent of mismatch between the period of circadian clocks and light/dark cycles determines time-to-emergence in fruit flies

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Insect Science 2015年第4期22卷 569-577页

作者： Pankaj Yadav Deepak Choudhury Madhumala K. Sadanandappa vijay Kumar sharma Chronobiology Laboratory Evolutionary and Organismal Biology Unit Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore 560064 Kamataka India

Circadian clocks time developmental stages of fruit flies Drosophila melanogaster, while light/dark （LD） cycles delimit emergence of adults, conceding only during the ＂allowed gate.＂ Previous studies have revealed that time-to-emergence can be altered by mutations in the core clock gene period （per）, or by altering the length of LD cycles. Since this evidence came from studies on genetically manipulated flies, or on flies maintained under LD cycles with limited range of periods, inferences that can be drawn are limited. Moreover, the extent of shortening or lengthening of time-to-emergence re- mains yet unknown. In order to pursue this further, we assayed time-to-emergence of D. rnelanogaster under 12 different LD cycles as well as in constant light （LL） and constant dark conditions （DD）. Time-to-emergence in flies occurred earlier under LL than in LD cycles and DD. Among the LD cycles, time-to-emergence occurred earlier under T4-T8, followed by T36-T48, and then T12-T32, suggesting that egg-to-emergence duration in flies becomes shorter when the length of LD cycles deviates from 24 h, bearing a strong positive and a marginally negative correlation with day length, for values shorter and longer than 24 h, respectively. These results suggest that the extent of mismatch between the period of circadian clocks and environmental cycles determines the time-to-emergence in Drosophila.

关键词： circadian Drosophila light/dark regimes period time-to-emergence

Role of early life exposure and environment on neurodegeneration: implications on brain disorders

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Translational Neurodegeneration 2014年第1期3卷 53-66页

作者： Shweta Modgil Debomoy K Lahiri vijay L sharma Akshay Anand Department of Neurology Neuroscience Research LabPost Graduate Institute of Medical Education and Research#3036Research Block-B160012 ChandigarhIndia Department of Zoology Panjab UniversityChandigarhIndia Department of Psychiatry Institute of Psychiatric ResearchIndiana University Medical Center IndianapolisIndianapolisUSA

Neurodegenerative diseases such as Alzheimer’s disease(AD),Parkinson’s disease(PD),Amyotrophic lateral sclerosis(ALS)and retinal degeneration have been studied extensively and varying molecular mechanisms have been proposed for onset of such *** genetic analysis of these diseases has also been described,yet the mechanisms governing the extent of vulnerability to such diseases remains *** studies have,therefore,focused on the role of environmental exposure in progression of such diseases especially in the context of prenatal and postnatal life,explaining how molecular mechanisms mediate epigenetic changes leading to degenerative *** review summarizes both the animal and human studies describing various environmental stimuli to which an individual or an animal is exposed during in-utero and postnatal period and mechanisms that promote *** SNPs mediating gene environment interaction are also ***,preventive and therapeutic strategies are suggested for effective intervention.

关键词： Aging Metals Epigenetics LEARn Methylation Pesticides

High-efficiency CdTe/CdS core/shell nanocrystals in water enabled by photo-induced colloidal hetero-epitaxy of CdS shelling at room temperature

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Nano Research 2015年第7期8卷 2317-2328页

作者： Hakimeh Zare Maziar Marandi Somayeh Fardindoost vijay Kumar sharma Aydan Yeltik Omid Akhavan Hilmi Volkan Demir Nima Taghavinia Institute for Nanoscience and Nanotechnology Shafif University of Technology Tehran 14588 Iran Department of Physics Faculty of Sciences Arak University Arak 38156-8-8349 Iran Department of Physics Department of Electrical and Electronics Engineering and UNAM-Institute of Materials Science and Nanotechnology Bilkent University Ankara Turkey Luminous Center of Excellence for Semiconductor Lighting and Displays Microelectronics Division School of Electrical and Electronics Engineering and Physics and Applied Physics Division School of Physical and Mathematical Sciences Nanyang Technological University Singapore 639798 Singapore Physics Department ShafifUniversity of Technology Tehran 14588 Iran

We report high-efficiency CdTe/CdS core/shell nanocrystals synthesized in water by epitaxially growing CdS shells on aqueous CdTe cores at room temperature, enabled by the controlled release of S species under low-intensity ultraviolet （UV） light illumination. The resulting photo-induced dissociation of S2O2- ions conveniently triggers the formation of critical two-dimensional CdS epitaxy on the CdTe surface at room temperature, as opposed to initiating the growth of individual CdS core-only nanocrystals. This controlled colloidal hetero-epitaxy leads to a substantial increase in the photoluminescence （PL） quantum yield （QY） of the shelled nanocrystals in water （reaching 64%）. With a systematic set of studies, the maximum PL QY is found to be almost independent of the illuminating UV intensity, while the shell formation kinetics required for reaching the maximum QY linearly depends on the illuminating UV intensity. A stability study of the QD films in air at various temperatures shows highly improved thermal stability of the shelled QDs （up to 120 ℃ in ambient air）. These results indicate that the proposed aqueous CdTe/CdS core/shell nanocrystals hold great promise for applications requiring efficiency and stability.

关键词： CdTe/CDs,core/shell nanocrystal thermal stability photochemical

Parallel effects of β-adrenoceptor blockade on cardiac function and fatty acid oxidation in the diabetic heart: Confronting the maze

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World Journal of Cardiology 2011年第9期3卷 281-302页

作者： vijay sharma John H McNeill Faculty of Pharmaceutical Sciences University of British Columbia Vancouver British Columbia BMJ Evidence Centre BMJ Group BMA House Tavistock Square London WC1H 9JR United Kingdom Department of Pathology Aberdeen Medical School Buildings Aberdeen Royal Infirmary

Diabetic cardiomyopathy is a disease process in which diabetes produces a direct and continuous myocardial insult even in the absence of ischemic, hypertensive or valvular disease. The β-blocking agents bisoprolol, carvedilol and metoprolol have been shown in large-scale randomized controlled trials to reduce heart failure mortality. In this review, we summarize the results of our studies investigating the effects of β-blocking agents on cardiac function and metabolism in diabetic heart failure, and the complex inter-related mechanisms involved. Metoprolol inhibits fatty acid oxidation at the mitochondrial level but does not prevent lipotoxicity; its benefi cial effects are more likely to be due to prosurvival effects of chronic treatment. These studies have expanded our understanding of the range of effects produced by β-adrenergic blockade and showhow interconnected the signaling pathways of function and metabolism are in the heart. Although our initial hypothesis that inhibition of fatty acid oxidation would be a key mechanism of action was disproved, unexpected results led us to some intriguing regulatory mechanisms of cardiac metabolism. The fi rst was upstream stimulatory factor-2-mediated repression of transcriptional master regulator PGC-1α, most likely occurring as a consequence of the improved function; it is unclear whether this effect is unique to β-blockers, although repression of carnitine palmitoyltransferase (CPT)-1 has not been reported with other drugs which improve function. The second was the identif ication of a range of covalent modifications which can regulate CPT-1 directly, mediated by a signalome at the level of the mitochondria. We also identif ied an important interaction between β-adrenergic signaling and caveolins, which may be a key mechanism of action of β-adrenergic blockade. Our experience with this labyrinthine signaling web illustrates that initial hypotheses and anticipat-ed directions do not have to be right in order to open up

关键词： Diabetes Heart failure β-blockers Cardiac metabolism Fatty acid oxidation