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Bioresorbable magnesium-based alloys containing strontium doped nanohydroxyapatite promotes bone healing in critical sized bone defect in rat femur shaft

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Journal of Magnesium and Alloys 2023年第1期11卷 270-286页

作者： Shazia Shaikh Irfan Qayoom R.Sarvesha ashok Kumar Department of Biological Sciences and Bioengineering Indian Institute of Technology KanpurKanpur 208016India Centre for Environmental Science and Engineering Indian Institute of Technology KanpurKanpur 208016India Department of Materials Science and Engineering Indian Institute of Technology KanpurKanpur 208016India Center for Nanosciences Indian Institute of Technology KanpurKanpur 208016India The Mehta Family Centre for Engineering in Medicine Indian Institute of Technology KanpurKanpur 208016India

Magnesium-based biomaterials have been in extensive research for orthopedic applications for decades due to their optimal mechanical features and osteopromotive nature;nevertheless,rapid degradation restricts their clinical *** this study,pristine magnesium was purified(P-Mg)using a melt self-purification approach and reinforced using indigenously synthesized nanohydroxyapatite(HAP,0.6 wt.%)and strontium substituted nanohydroxyapatite(SrHAP,0.6 wt.%)using a low-cost stir assisted squeeze casting method to control their degradation *** electron back-scattered diffraction(EBSD)and X-ray diffraction(XRD)examinations,all casted materials were carefully evaluated for microstructure and phase *** characteristics,in vitro degradation,and in vitro biocompatibility with murine pre-osteoblasts were also tested on the fabricated *** in vivo examination of bone formation,osteointegration,and degradation rate,the magnesium-based alloys were fabricated as small cylindrical pins with a diameter of 2.7 mm and a height of 2 *** pins were implanted in a critical-sized defect in a rat femur shaft(2.7 mm diameter and 2 mm depth)for 8 weeks and evaluated by microCT and histological evaluation for bone growth and *** compared to P-Mg and P-MgHAP,micro-CT and histological analyses revealed that the P-MgSrHAP group had the highest bone formation towards the periphery of the implant and hence maximum *** the removed pins from the bone defect were analyzed using GIXRD,they displayed hydroxyapatite peaks that were consistent with *** P-Mg,P-MgHAP,and P-MgSrHAP 8 weeks after implantation,in vivo degradation rates derived from micro-CT were around 0.6 mm/year,0.5 mm/year,and 0.1 mm/year,***,P-MgSrHAP possesses the requisite degradation rate as well as sufficient mechanical and biological properties,indicating that it has the potential to be used in the development/fabrication of bi

关键词： Magnesium purification Reinforcement Degradation rate Nanocement Bone regeneration

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Interplay between genome organization and epigenomic alterations of pericentromeric DNA in cancer

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Journal of Genetics and Genomics 2021年第3期48卷 184-197页

作者： Subhadip Kundu M.D.Ray ashok Sharma Laboratory of Chromatin and Cancer Epigenetics Department of BiochemistryAll India Institute of Medical SciencesAnsari NagarNew Delhi 110029India Department of Surgical Oncology IRCHAll India Institute of Medical SciencesAnsari NagarNew Delhi 110029India

In eukaryotic genome biology,the genomic organization inside the three-dimensional(3D)nucleus is highly complex,and whether this organization governs gene expression is poorly *** lamina(NL)is a filamentous meshwork of proteins present at the lining of inner nuclear membrane that serves as an anchoring platform for genome *** chromatin domains termed as lamina-associated domains(LADs),play a major role in silencing genes at the nuclear *** interaction of the NL and genome is dynamic and ***,many genes change their positions during developmental processes or under disease conditions such as cancer,to activate certain sorts of genes and/or silence *** heterochromatin(PCH)is mostly in the silenced region within the genome,which localizes at the nuclear *** show that several genes located at the PCH are aberrantly expressed in *** interesting question is that despite being localized in the pericentromeric region,how these genes still manage to overcome pericentromeric *** epigenetic mechanisms control the expression of the pericentromeric region,recent studies about genome organization and genome-nuclear lamina interaction have shed light on a new aspect of pericentromeric gene regulation through a complex and coordinated interplay between epigenomic remodeling and genomic organization in Cancer.

关键词： LADs Pericentromere Heterochromatin Gene regulation Epigenetics Cancer Genome organization

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Fourth Derivative Spectrophotometric Method for the Determination of Fungicide Maneb Using Sodium Molybdate

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American Journal of Analytical Chemistry 2011年第2期2卷 158-163页

作者： Manpreet Kaur ashok Kumar Malik Baldev singh 不详

A highly sensitive fourth derivative spectrophotometric method is presented for the residue analysis of ethylenebis dithiocarbamate fungicide Maneb. The fungicide maneb forms a blue complex with sodium molybdate on heating which is studied spectrophotometrically. The method has been successfully applied to maneb determination in wheat grains and soft drinks with high recoveries. The analytical sensitivity of the present method has been found to be 0.0011 μg/mL.

关键词： Derivative Spectrophotometry Maneb Sodium Molybdate

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Emerging molecules,tools,technology,and future of surgical knife in gastroenterology

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World Journal of Gastrointestinal Surgery 2024年第4期16卷 988-998页

作者： ashok Kumar Anirudh Goyal Department of Surgical Gastroenterology Sanjay Gandhi Post Graduate Institute of Medical SciencesLucknow 226014Uttar PradeshIndia

The 21^(st) century has started with several innovations in the medical sciences,with wide applications in health care *** development has taken in the field of medicines(newer drugs/molecules),various tools and technology which has completely changed the patient management including abdominal *** for abdominal diseases has moved from maximally invasive to minimally invasive(laparoscopic and robotic)*** of the newer medicines have its impact on need for surgical *** article focuses on the development of these emerging molecules,tools,and technology and their impact on present surgical form and its future effects on the surgical intervention in gastroenterological diseases.

关键词： Newer molecules Tools and technology Gastroenterology Future of surgical knife

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Synthesis and spectroscopic investigations of trivalent europium- doped Z_(2)Si_(3)O_(8)(Z = Mg, Ca and Sr) nanophosphors for display applications

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Rare Metals 2021年第9期40卷 2610-2617页

作者： Suman Sheoran Kuldeep singh Vijeta Tanwar Sitender singh Anura Samantilleke Devender singh Department of Chemistry Maharshi Dayanand UniversityRohtak 124001India Centro de Fisica Universidade of MinhoBraga 4710057Portugal

To explore the silicate lattice-based nanophosphors, a series of Eu3+-doped Z_(2)Si_(3)O_(8)(Z = Mg, Ca and Sr) materials were prepared by sol–gel procedure. The metal nitrates and silica powder were used as precursor components for the synthesis of these luminescent materials. Photoluminescence(PL) emission spectra, powder X-ray diffraction(PXRD), energy-dispersive X-ray spectroscopy(EDS), Fourier transform infrared spectroscopy(FTIR) and transmission electron microscopy(TEM)spectroscopic techniques were applied for the characterization of the fabricated materials. Three peaks were observed at 589, 613 and 650–652 nm corresponding to ^(5)D_(0)→^(7)F_(1-3) transition in PL emission spectra. Upon395 nm excitation and at 0.03 mol Eu3+, these nanophosphors displayed optimum photoluminescence with the most intense peak analogous to ^(5)D_(0)→^(7)F_(2)transition of dopant ion. The as-prepared phosphor materials were re-heated at1050 and 1150 ℃ to observe the consequences of higher temperatures on the emission intensity and crystal *** analysis confirmed that all the synthesized materials were of crystalline nature, and the crystallinity was observed to be improved by increasing the temperature. In the FTIR spectrum, peaks at 483 and 610 cm^(-1) proved the existence of SiO_(4)group in Ca_(2)Si_(3)O_(8), and the peak centered at 417 cm^(-1) confirmed the presence of MgO6 octahedral in Mg_(2)Si_(3)O_(8) materials. TEM images were used to determine the particle size(13–35 nm) and to study the threedimensional structure of nanophosphor materials. The experimental studies indicate that these materials may be promising as red-emitting nanophosphors for white lightemitting diodes.

关键词： Z_(2)Si_(3)O_(8) Nanophosphors Sol–gel Photoluminescence Crystalline

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Fractionally Delayed Kalman Filter

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 169-177页

作者： Abhinoy Kumar singh Discipline of Electrical Engineering Indian Institute of Technology Indore

The conventional Kalman filter is based on the assumption of non-delayed measurements. Several modifications appear to address this problem, but they are constrained by two crucial assumptions: 1) the delay is an integer multiple of the sampling interval, and 2) a stochastic model representing the relationship between delayed measurements and a sequence of possible non-delayed measurements is known. Practical problems often fail to satisfy these assumptions, leading to poor estimation accuracy and frequent track-failure. This paper introduces a new variant of the Kalman filter, which is free from the stochastic model requirement and addresses the problem of fractional *** proposed algorithm fixes the maximum delay(problem specific), which can be tuned by the practitioners for varying delay possibilities. A sequence of hypothetically defined intermediate instants characterizes fractional delays while maximum likelihood based delay identification could preclude the stochastic model requirement. Fractional delay realization could help in improving estimation accuracy. Moreover, precluding the need of a stochastic model could enhance the practical applicability. A comparative analysis with ordinary Kalman filter shows the high estimation accuracy of the proposed method in the presence of delay.

关键词： Gaussian likelihood Kalman filter optimal Kalman gain randomly delayed measurements

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Transposon-based genetic diversity assessment in wild and cultivated barley

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The Crop Journal 2017年第4期5卷 296-304页

作者： Surinder singh Prabhjot singh Nandha Jaswinder singh Department of Plant Science McGill University 21111 Lakeshore Road Sainte-Anne-de-Bellevue Quebec H9X 3V9 Canada Department of Plant Sciences University of Saskatchewan 51 campus drive Saskatoon SK S7N 5A8 Canada

Transposable element-based molecular markers can be utilized to investigate genetic diversity and to create genetic linkage *** this study,Class I and class II transposons were employed to obtain a comparative account of genetic diversity between wild and cultivated barley *** types of PCR-based techniques were used:IMP(Inter MITE Polymorphism),IRAP(Inter-Retrotransposon Amplified Polymorphism)and REMAP(Retrotransposon-Microsatellite Amplified Polymorphism).Specific primer pairs for IMP,IRAP,and REMAP detected a total of 200 bands with an average of 20 bands per *** mean polymorphic information content(PIC)and discrimination power(D)values in all 47 genotypes from these three types of transposon-based polymorphisms were 0.910 and0.935,*** Pair Group Method with Arithmetic mean(UPGMA)-based cluster analysis classified all 47 genotypes,both wild and cultivated,into separate groups consistent with their geographical *** followed by chromosome location of polymorphic bands enables precise gene introgression from wild gene pool to cultivated *** highly polymorphic nature of these marker systems makes them suitable for use in varietal identification and MAS-based breeding programs in barley and other cereals.

关键词： IMP REMAP IRAP Polymorphic information content (PIC) Discrimination power (D)

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Major Development Under Gaussian Filtering Since Unscented Kalman Filter

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1308-1325页

作者： Abhinoy Kumar singh IEEE Department of Electrical Engineering Indian Institute of Technology Indore

Filtering is a recursive estimation of hidden states of a dynamic system from noisy *** problems appear in several branches of science and technology,ranging from target tracking to biomedical monitoring.A commonly practiced approach of filtering with nonlinear systems is Gaussian *** early Gaussian filters used a derivative-based implementation,and suffered from several drawbacks,such as the smoothness requirements of system models and poor stability.A derivative-free numerical approximation-based Gaussian filter,named the unscented Kalman filter(UKF),was introduced in the nineties,which offered several advantages over the derivativebased Gaussian *** the proposition of UKF,derivativefree Gaussian filtering has been a highly active research *** paper reviews significant developments made under Gaussian filtering since the proposition of *** review is particularly focused on three categories of developments:i)advancing the numerical approximation methods;ii)modifying the conventional Gaussian approach to further improve the filtering performance;and iii)constrained filtering to address the problem of discrete-time formulation of process *** review highlights the computational aspect of recent developments in all three *** performance of various filters are analyzed by simulating them with real-life target tracking problems.

关键词： Bayesian framework cubature rule-based filtering Gaussian filters Gaussian sum and square-root filtering nonlinear filtering quadrature rule-based filtering unscented transformation

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STOCHASTIC SYNCHRONIZATION OF CIRCADIAN RHYTHMS

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Journal of Systems Science & Complexity 2010年第5期23卷 978-988页

作者： RajKumar Brojen singh Vikram singh Ram RAMASWAMY Centre for Interdisciplinary Research in Basic Sciences Jamia Milia Islamia New Delhi 110025 India Center for Computational Biology and Bioinformatics School of Information Technology Jawaharlal Nehru University New Delhi 110067 India Center for Computational Biology and Bioinformatics School of Information Technology and School of Physical Sciences Jawaharlal Nehru University New Delhi 110067 India

Models of circadian genetic oscillators involving interlinked feedback processes in molecular level genetic networks in Drosophila melanogaster and Neurospora crassa are studied, and mechanisms whereby synchronization can arise in an assembly of cells are examined. The individual subcellular circadian oscillatory processes are stochastic in nature due to the small numbers of molecules that are involved, and are subject to large fluctuations. The authors investigate and present the simulations of the stochastic dynamics of ensembles of clock-regulating proteins in different nuclei that communicate via ancillary small molecules, environmental parameters, additive cellular noise, or through diffusive processes. The results show that the emergence of collective oscillations is a macroscopic observable which has its origins in the microscopic coupling between distinct cellular oscillators.

关键词： Coupling stochastic dynamics synchrony.

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Assay method for quality control and stability studies of a new antimalarial agent (CDRI 99/411)

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Journal of Pharmaceutical Analysis 2013年第5期3卷 335-340页

作者： Kiran Khandelwal Shakti Deep Pachauri Sofa Zaidi Pankaj Dwivedi ashok Kumar Sharma Chandan singh Anil Kumar Dwivedi Division of Pharmaceutics CSIR-Central Drug Research Institute Division of Medicinal and Process Chemistry CSIR-Central Drug Research Institute

CDRI compound no. 99/411 is a potent 1,2,4-trioxane antimalarial candidate drug under development at our Institute. An HPLC method for determination of CDRI 99/411 with its starting material and intermediates has been developed and validated for in process quality control and stability studies. The analytical performance parameters such as linearity, precision, accuracy, specificity, limit of detection （LOD） and lower limit of quantification （LLOQ） were determined according to International Conference on Harmonization ICH Q2（R1） guidelines. HPLC separation was achieved on a RP-select B Lichrosphere~ column （250 mm x 4 ram, 5 lam, Merck） using water containing 0.1% glacial acetic acid and acetonitrile as the mobile phase in a gradient elution. The eluents were monitored by a photo diode array detector at 245 and 275 nm. Based on signal to noise ratio of 3 and 10 the LOD of CDRI 99/411 was 0.55 μg/mL, while the LLOQ was 1.05 μg/mL. The calibration curves were linear in the range of 1.05- 68 μg/mL. Precision of the method was determined by inter- and intra-assay variations within the acceptable range.

关键词： HPLC Trioxane Process quality control Stability

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