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Development and Validation of a Method for Simultaneous Determination of Metformin Hydrochloride and Sitagliptin Phosphate in a Formulation by RP-HPLC

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American Journal of Analytical Chemistry 2014年第11期5卷 737-742页

作者： P. B. N. Prasad k. satyanarayana G. k.ishnamohan Central Drugs Testing Laboratory Hyderabad India Department of Pharmacy JNTUH Hyderabad India NATCO Pharma R&D Hyderabad India

Present study was aimed to develop and validate a reverse-phase high-performance liquid chromatography method for simultaneous determination of sitagliptin phosphate and metformin hy-drochloride in a mark.ted formulation. The drug separation was performed on Hibar-240, Li-chrosphere-100 C18 ODS (250 × 4.6 mm, 5 μm) column, at a flow rate of 1 mL/min. The mobile phase used was a mixture of methanol: potassium di-hydrogen phosphate buffer at a ratio of 70:30 v/v. The detection was carried out at a wavelength of 266 nm. The retention times of sitagliptin phosphate and metformin hydrochloride were found as 6.1 and 4.9 min respectively. Linear calibration curves with good correlation coefficients were obtained over the concentration ranges of 10 - 50 μg/mL for sitagliptin and 20 - 100 μg/mL for metformin. The limit of detection was 0.016 and 0.14 μg/mL and the limit of quantification was 0.048 and 0.42 μg/mL for sitagliptin phosphate and metformin hydrochloride respectively. Validation of the method demonstrated system selectivity, specificity, linearity, accuracy and precision. The developed method was found useful in the simultaneous analysis of sitagliptin phosphate and metformin hydrochloride in formulation.

关键词： Sitagliptin Phosphate Metformin Hydrochloride Reverse Phase High Performance Liquid Chromatography (RPHPLC) International Committee on Harmonization (ICH) Guidelines Limit of Detection (LOD) Limit of Quantitation (LOQ) Linearity Precision Accuracy & Reproducibility

Simple and Efficient Method for Deprotection of Tetrahydropyranyl Ethers by Using Silica Supported Sodium Hydrogen Sulphate

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Chinese Journal of Chemistry 2012年第5期30卷 1189-1191页

作者： k.mar k. Ravi satyanarayana P. V. V. Reddy B. Srinivasa RA Chem Pharma Limited Research and Development Division Prasanth Nagar Hyderabad 500072 AP India Department of Chemistry Aeharya Nagarjuna University Nagarjuna Nagar Guntur 522510 AP India

Tetrahydropyranyl （THP） ethers have been efficiently and simply deprotected by using Silica supported sodium hydrogen sulphate （NaHSO4-SiO2） in methanol at room temperature to regenerate the parent alcohols in hig... 详细信息

关键词： THP ethers deprotection NaHSO4-SiO2 methanol reusable catalyst

Gastric digestion of pea ferritin and modulation of its iron bioavailability by ascorbic and phytic acids in caco-2 cells

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World Journal of Gastroenterology 2007年第14期13卷 2083-2088页

作者： satyanarayana Bejjani Raghu Pullak.andam Ravinder Punjal k.Madhavan Nair Micronutrient Research Group National Institute of Nutrition Indian Council of Medical ResearchJamai OsmaniaHyderabad 500007India

AIM： To understand the digestive stability and mechanism of release and intestinal uptak. of pea ferritin iron in caco-2 cell line model.METHODS： Pea seed ferritin was purified using salt fractionation followed by gel filtration *** bioavailability of ferritin iron was assessed using coupled in vitro digestion/Caco-2 cell model in the presence or absence of ascorbic acid and phytic ***-2 cell ferritin formation was used as a surrogate mark.r of iron uptak.. Structural changes of pea ferritin under simulated gastric pH were characterized using electrophoresis, gel filtration and circular dichroism spectroscopy.RESULTS： The caco-2 cell ferritin formation was significantly increased （P 〈 0.001） with FeSO4 （19.3±9.8 ng/mg protein） and pea ferritin （13.9 ± 6.19 ng/mg protein） compared to the blank.digest （3.7 ± 1.8 ng/mg protein）. Ascorbic acid enhanced while phytic acid decreased the pea ferritin iron bioavailability. However,either in the presence or absence of ascorbic acid, the ferritin content of caco-2 cells was significantly less with pea ferritin than with FeSO4. At gastric pH, no band corresponding to ferritin was observed in the presence of pepsin either on native PAGE or SDS-PAGE. Gel filtration chromatography and circular dichroism spectroscopy revealed a pH dependent loss of quaternary and secondary structure.CONCLUSION： Under gastric conditions, the iron core of pea ferritin is released into the digestive medium due to acid induced structural alterations and dissociation of protein. The released iron interacts with dietary factors leading to modulation of pea ferritin iron bioavailability,resembling the typical characteristics of non-heme iron.

关键词： Pea ferritin Bioavailability Caco-2 cells Phytic acid Ascorbic acid

A relativistic model of stellar objects with core-crust-envelope division

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Research in Astronomy and Astrophysics 2021年第7期21卷 71-83页

作者： Ravindra k.Bisht satyanarayana Gedela Neeraj Pant Neeraj Tewari Department of Mathematics National Defence AcademyKhadakwaslaPune-411023India Department of Mathematics SSJ CampusKumaun UniversityAlmora-263601India Department of Physics Lajpat Rai CollegeGhaziabad-201005India

In this work. we present a cogent and physically well-behaved solution for neutron stars envisaged with a core layer having quark.matter satisfying the MIT-bag equation of state(Eo S), meso layer with Bose-Einstein condensate(BEC) matter satisfying modified BEC Eo S and an envelope having neutron fluid and Coulomb liquids satisfying quadratic Eo S. All the required physical and geometrical parameters lik. gravitational potentials, pressures, radial velocity, anisotropy, adiabatic index, mass function, compactification factor, and gravitational and surface redshift functions show a feasible trend and are continuous with smooth variation throughout the interior and across the regions of the ***, causality condition, energy conditions, static stability criterion(using Tolman-OppenheimerVolk.ff equation) and Herrera crack.ng stability criterion are met throughout the star. The approach seems to be resulting in more realistic and accurate modeling of stellar objects, particularly realized by us for X-ray binary stars 4 U 1608–52(M = 1.7 M_⊙, R = 9.5 k.) and SAX J1808.4–3658(M = 1.2 M_⊙,R = 7.2 k.). Furthermore, we have ascertained that the continuity of the stability factor in all three regions of the stars demand a smaller core. As the core region of the star increases, the stability factor becomes discontinuous at all the interfaces inside the star.

关键词： stars:interiors stars:neutron Galaxy:stellar content

Block.hain-Based Secured IPFS-Enable Event Storage Technique With Authentication Protocol in VANET

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IEEE/CAA Journal of Automatica Sinica 2021年第12期8卷 1913-1922页

作者： Sanjeev k.mar Dwivedi Ruhul Amin satyanarayana Vollala Department of CSE Dr.Shyama Prasad Mukherjee International Institute of Information Technology Naya RaipurChhattisgarh 492002India

In recent decades,intelligent transportation systems(ITS)have improved drivers’safety and have shared information(such as traffic congestion and accidents)in a very efficient ***,the privacy of vehicles and the security of event information is a major *** problem of secure sharing of event information without compromising the trusted third party(TTP)and data storage is the main issue in *** technologies can resolve this problem.A work.has been published on block.hain-based protocol for secure sharing of events and authentication of *** protocol addresses the issue of the safe storing of event ***,authentication of vehicles solely depends on the cloud *** a result,their scheme utilizes the notion of partially decentralized *** paper proposes a novel decentralized architecture for the vehicular ad-hoc network.VANET)without the cloud *** work.also presents a protocol for securing event information and vehicle authentication using the block.hain *** this protocol,the registered user accesses the event information securely from the interplanetary file system(IPFS).We incorporate the IPFS,along with block.hain,to store the information in a fully distributed *** proposed protocol is compared with the *** comparison provides desirable security at a reasonable *** evaluation of the proposed smart contract in terms of cost(GAS)is also discussed.

关键词： Authentication block.hain interplanetary file system(IPFS) secure information sharing security

A new class of viable and exact solutions of EFEs with k.rmark.r conditions:an application to cold star modeling

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Research in Astronomy and Astrophysics 2021年第5期21卷 71-83页

作者： Neeraj Pant Megandhren Govender satyanarayana Gedela Department of Mathematics National Defence AcademyKhadakwaslaPune-411023India Department of Mathematics Faculty of Applied SciencesDurban University of TechnologyDurbanSouth Africa Department of Mathematics SSJ CampusKumaun UniversityAlmora-263601India

In this work.we present a theoretical framework.within Einstein’s classical general relativity which models stellar compact objects such as PSR J1614-2230 and SAX *** Einstein field equations are solved by assuming that the interior of the compact object is described by a class I *** so-called k.rmark.r condition arising from this requirement is integrated to reduce the gravitational behaviour to a single generating *** appealing to physics we adopt a form for the gravitational potential which is sufficiently robust to accurately describe compact *** model satisfies all the requirements for physically realistic stellar structures.

关键词： Compact star anisotropy embedding class Einstein field equations adiabatic index

Insider Attack.Prevention:LAPUP—Lightweight Authentication Protocol Using PUF

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Journal of Communications and Information Network. 2024年第2期9卷 192-206页

作者： Siranjeevi Rajamanick.m satyanarayana Vollala N.Ramasubramanian Department of Computer Engineering Government Polytechnic CollegeTiruchirappalli 620022India Department of Computer Science and Engineering Dr.Shyama Prasad Mukherjee International Institute of Information Technology-Naya RaipurChhattisgarh 493661India Department of Computer Science and Engineering National Institute of TechnologyTiruchirappalli 620015India

The incredible progress in technologies has drastically increased the usage of Web *** share their credentials lik. userid and password or use their smart cards to get authenticated by the application *** cards are handy to use,but they are susceptible to stolen smart card attack. and few other notable security *** prefer to use Web applications that guarantee for security against several security attack.,especially insider attack.,which is *** of several existing schemes prove the security pitfalls of the protocols from preventing security attack.,specifically insider *** paper introduces LAPUP:a novel lightweight authentication protocol using physically unclonable function(PUF)to prevent security attack.,principally insider *** PUFs are used to generate the security k.ys,challenge-response pair(CRP)and hardware signature for designing the *** transmitted messages are shared as hash values and encrypted by the k.ys generated by *** messages are devoid of all possible attack. executed by any attack.r,including insider *** is also free from stolen verifier attack.,as the databases are secured by using the hardware signature generated by *** analysis of the protocol exhibits the strength of LAPUP in preventing insider attack. and its resistance against several other security *** evaluation results of the communication and computation costs of LAPUP clearly shows that it achieves better performance than existing protocols,despite providing enhanced security.

关键词： physically unclonable function(PUF) insiderattack. authenticationk.ymanagementserver(Ak.S) security

Optimal machining conditions for turning Ti-6Al-4V using response surface methodology

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Advances in Manufacturing 2013年第4期1卷 329-339页

作者： satyanarayana k.saraju Venu Gopal Anne Department of Mechanical Engineering National Institute of TechnologyWarangal

Machining titanium is one of ever-increasing magnitude problems due to its characteristics such as low thermal conductivity, modulus of elasticity and work.hardening. The efficient titanium alloy machining involves a proper selection of process parameters to minimize the tangential force （Fz） and surface roughness （Ra）. In the present work. the performance of PVD/TiA1N coated carbide inserts was investigated using response surface methodology （RSM） for turning Ti-6A1-4V. The effects of process parameters such as speed （v）, feed （/＇）, depth of cut （d） and back.rak. angle （Ty） on Fz and Ra were investi- gated. The experimental plan used for four factors and three levels was designed based on face centered, central composite design （CCD）. The experimental results indi- cated that Fz increased with the increase in d, f and decreased with the increase in v and yy, whereas Ra decreased with the increase in v and 7y, and increased with d and v. The goodness of fit of the regression equations and model fits （R2） for Fz and Ra were found to be 0.968 and 0.970, which demonstrated that it was an effective model. A confirmation test was also conducted in order to verify the correctness of the model.

关键词： Ti-6Al-4V - Response surfacemethodology ~ Cutting force ~ Surface roughness

A REMARk.ON LARGE TIME ASYMTOTICS FOR SOLUTIONS OF A NONHOMOGENEOUS VISCOUS BURGERS EQUATION

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Acta Mathematica Scientia 2023年第3期43卷 1323-1332页

作者： Manas Ranjan SAHOO satyanarayana ENGU Smriti TIWARI School of Mathematical Sciences National Institute of Science Education and ResearchAn OCC of Homi Bhabha National InstituteBhubaneswarKhurdaOdishaP.O.Jatni752050India Department of Mathematics National Institute of TechnologyWarangalTelangana506004India

The existence, uniqueness and regularity of solutions to the Cauchy problem posed for a nonhomogeneous viscous Burger's equation were shown in Chung, k.m and Slemrod [1] by assuming suitable conditions on initial data. Moreover, they derived the asymptotic behaviour of solutions of the Cauchy problem by imposing additional conditions on initial data. In this article, we obtain the same asymptotic behaviour of solutions to the Cauchy problem without imposing additional condition on initial data.

关键词： modified Bessel functions integral equation large time asymptotics convolution of functions