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Compression Molded Ultra High Molecular Weight Polyethylene-Hydroxyapatite-Aluminum Oxide-Carbon Nanotube Hybrid Composites for Hard Tissue Replacement

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Journal of Materials Science & Technology 2013年第6期29卷 514-522页

作者： Ankur Gupta Garima tripathi Debrupa Lahiri Kantesh Balani Department of Materials Science and Engineering Indian Institute of Technology KanpurKanpur 208016India Department of Mechanical and Materials Engineering.Florida International University MiamiFL 33174USA

Ultra high molecular weight polyethylene （UHMWPE） is widely used for articulating surfaces in total hip and knee replacements. In the present work, UHMWPE based polymer composites were synthesized by synergistic reinforcing of bioactive hydroxyapatite （HA）, bioinert aluminum oxide （Al2O3）, and carbon nanotubes （CNTs） using compression molding. Phase and microstructural analysis suggests retention of UHMWPE and reinforcing phases in the compression molded composites. Microstructural analysis elicited variation in densification due to the size effect of the reinforcing particles. The hybrid composites exhibited hardness, elastic modulus and toughness comparable to that of UHMWPE. The interfacial effect of reinforcement phases has evinced the effectiveness of Al2O3 over HA and CNT reinforcements, depicting synergistic enhancement in hardness and elastic modulus. Weak interfacial bonding of polymer matrix with HA and CNT requires utilization of coupling agents to achieve enhanced mechanical properties without deteriorating cytocompatible properties.

关键词： Compression molding Ultra high molecular weight polyethylene (UHMWPE) Hydroxyapatite Aluminum oxide (AI2O3) Carbon nanotubes (CNTs) Nanoindcntation

A review of TiO_2 nanoparticles

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Chinese Science Bulletin 2011年第16期56卷 1639-1657页

作者： GUPTA Shipra Mital tripathi Manoj University School of Basic and Applied Sciences Guru Gobind Singh Indraprastha UniversitySector 16C DwarkaDelhi 110075India

Climate change and the consumption of non-renewable resources are considered as the greatest problems facing *** of this,photocatalysis research has been rapidly ***2 nanoparticles have been extensively investigated for photocatalytic applications including the decomposition of organic compounds and production of H2 as a fuel using solar energy. This article reviews the structure and electronic properties of TiO2,compares TiO2 with other common semiconductors used for photocatalytic applications and clarifies the advantages of using TiO2 ***2 is considered close to an ideal semi- conductor for photocatalysis but possesses certain limitations such as poor absorption of visible radiation and rapid recombination of photogenerated electron/hole *** this review article,various methods used to enhance the photocatalytic characteristics of TiO2 including dye sensitization,doping,coupling and capping are *** and energy applications of TiO2, including photocatalytic treatment of wastewater,pesticide degradation and water splitting to produce hydrogen have been summarized.

关键词：纳米二氧化钛光催化特性审查不可再生资源催化应用可见光辐射光催化处理气候变化

Antioxidant and antiarthritic potential of berberine: In vitro and in vivo studies

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Chinese Herbal Medicines 2023年第4期15卷 549-555页

作者： Shweta Jain Shalini tripathi Pushpendra Kumar tripathi Sir Madanlal Institute of Pharmacy Etawah 206130India Rameshwaram Institute of Technology and Management Dr.A.P.J.Abdul Kalam Technical UniversityLucknow 226001India Institute of Pharmaceutical Sciences University of LucknowLucknow 226001India

Objective: To extract and isolate berberine from Berberis aristata(Berberidaceae). Isolated berberine was characterised using spectroscopy and its antioxidant and antiarthritic activity was ***: The berberine was isolated from B. aristata using microwave-assisted extraction(MAE) and characterised by a spectroscopic technique. The isolated berberine was evaluated for its antioxidant activity in DPPH, nitric oxide, and superoxide scavenging assays, while antiarthritic activity was evaluated in the complete freund’s adjuvant(CFA)-induced arthritis rat ***: The antioxidant activity of berberine revealed potent antioxidant activity in DPPH, nitric oxide,and superoxide scavenging assays. The in vivo antiarthritic activity of berberine in the CFA-induced arthritis rat model showed a significant reduction in paw diameter, arthritic score, and an increase in body weight. Furthermore, a concentration-dependent ameliorating action of berberine on haematological parameters was noticed. Proinfammatory biomarkers, including IL-6, IL-10, and TGF-b in serum were reported, and histopathology examination revealed that berberine decreased pannus formation, synovial hyperplasia, and bone erosion. Radiographic investigation showed soft tissue infammation, bone resorption and erosion, joint gap reduction, and substantial connective tissue expansion after treatment with ***: The ameliorating action on haematological parameters and proinfammatory biomarkers of berberine makes them a suitable remedy for the treatment of arthritis.

关键词： antioxidant antiarthritic activity berberine Berberis aristata DC microwave assistance

The novel hierarchical clustering approach using selforganizing map with optimum dimension selection

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Health Care Science

Health Care Science 2024年第2期3卷 88-100页

作者： Kshitij tripathi Department of Computer Applications The Maharaja SayajiRao University of BarodaVadodaraGujaratIndia

Introduction: Data clustering is an important field of machine learningthat has applicability in wide areas, like, business analysis, manufacturing,energy, healthcare, traveling, and logistics. A variety of clusteringapplications have already been developed. Data clustering approachesbased on self-organizing map (SOM) generally use the map dimensions (ofthe grid) ranging from 2 × 2 to 8 × 8 (4–64 neurons [microclusters])without any explicit reason for using the particular dimension, andtherefore optimized results are not obtained. These algorithms use somesecondary approaches to map these microclusters into the lowerdimension (actual number of clusters), like, 2, 3, or 4, as the case maybe, based on the optimum number of clusters in the specific data set. Thesecondary approach, observed in most of the works, is not SOM and is analgorithm, like, cut tree or the ***: In this work, the proposed approach will give an idea of how toselect the most optimal higher dimension of SOM for the given data set,and this dimension is again clustered into the lower actual *** and secondary, both utilize the SOM to cluster the data anddiscover that the weight matrix of the SOM is very meaningful. Theoptimized two-dimensional configuration of SOM is not the same forevery data set, and this work also tries to discover this ***: The adjusted randomized index obtained on the Iris, Wine,Wisconsin diagnostic breast cancer, New Thyroid, Seeds, A1, Imbalance,Dermatology, Ecoli, and Ionosphere is, respectively, 0.7173, 0.9134,0.7543, 0.8041, 0.7781, 0.8907, 0.8755, 0.7543, 0.5013, and 0.1728, whichoutperforms all other results available on the web and when no reductionof attributes is done in this ***: It is found that SOM is superior to or on par with otherclustering approaches, like, k-means or the other, and could be usedsuccessfully to cluster all types of data sets. Ten benchmark data sets fromdiverse domains like medical, biological

关键词： artificial neural network clustering self-organizing map

Investigation of Weakly Relativistic Ponderomotive Effects on Self-Focusing During Interaction of High Power Elliptical Laser Beam with Plasma

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Communications in Theoretical Physics 2017年第8期67卷 245-249页

作者： Keshav Walia Deepak tripathi Yachna Tyagi Department of Physics DAV University Jalandhar Department of Physics AIAS Amity University Noida

This paper presents an investigation of weakly relativistic ponderomotive effects on self-focusing during interaction of high power elliptical laser beam with plasma. The nonlinear differential equations for the beam width parameters of elliptical laser beam have set up by using Wentzal–Krammers–Brillouin(WKB) and paraxial approximations. These equations have been solved numerically by using fourth order Runge–Kutta method to study the variation of these beam width parameters against normalized distance of propagation. Effects of variation in laser beam intensity,plasma density and electron temperature on the beam width parameters are also analyzed.

关键词： self-focusing elliptical laser beam weakly relativistic ponderomotive effects plasma density elec-tron temperature

One-pot synthesis of silver nanocomposites from Achyranthes aspera:An eco-friendly larvicide against Aedes aegypti L.

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Asian Pacific Journal of Tropical Biomedicine 2020年第2期10卷 54-64页

作者： Aarti Sharma Pushplata tripathi Sarita Kumar Department of Life Sciences(SOS) Indira Gandhi National Open UniversityMaidan GarhiNew Delhi 110068India Department of Zoology Acharya Narendra Dev CollegeUniversity of DelhiKalkaJiNew Delhi 110019India

Objective:To formulate silver nanocomposites from Achyranthes aspera leaf extracts and evaluate its larvicidal activity against Aedes ***:The silver nanocomposites were synthesized from Achyranthes aspera leaf *** process was optimized and traced through UV-visible and photon correlation *** larvicidal potential of silver nanocomposites of Achyranthes aspera leaf extracts was assessed against the early fourth instars of Aedes aegypti and three non-target ***,the most effective and eco-safe nanocomposite was characterized by different biophysical techniques including scanning electron microscopy(SEM),energy dispersive X-ray(EDX)spectroscopy,transmission electron microscopy(TEM),X-ray diffraction(XRD)and Fourier transform-infrared spectroscopy(FT-IR).Results:The formulated silver nanocomposites exhibited efficient larvicidal efficacy against Aedes *** with silver nanocomposites formulated using different Ag NO3 concentrations(3,4,and 5 m M)revealed respective LC50 values of 37.570,6.262 and 1.041μg/m L;5.819,1.412 and 0.489μg/m L;and 5.519,1.302 and 0.267μg/m L after 24,48 and 72 *** silver nanocomposites with 4 m M Ag NO3 were selected for *** and TEM analysis revealed spherical,poly-dispersed structure with varied diameters of 1-25 *** XRD analysis established the crystalline and face-centred-cubic structure of silver nanocomposites with the maximum peak at a 2θvalue of 37.42°.The EDX pattern showed the presence of Ag,O and C in the nanocomposites in their order of weight%.The FT-IR displayed visibly distinct peaks in different ranges demonstrating the intricacy of silver *** addition,the lethal concentrations of silver nanocomposites of Achyranthes aspera leaf extracts against Aedes aegypti larvae were non-toxic to non-target organisms including Gambusia affinis,Daphnia magna and Moina ***:Silver nanocomposites synthesized with leaf extract of Achy

关键词： Achyranthes aspera Aedes aegypti Larvicidal Silver nanocomposites SEM-TEM EDX XRD FT-IR

Prospects for 3D bioprinting of organoids

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Bio-Design and Manufacturing 2021年第3期4卷 627-640页

作者： Preety Rawal Dinesh M.tripathi Seeram Ramakrishna Savneet Kaur Department of Molecular and Cellular Medicine Institute of Liver and Biliary Sciences(ILBS)D1Vasant KunjNew Delhi 110070India School of Biotechnology Gautam Buddha UniversityGreater NoidaIndia Department of Mechanical Engineering National University of SingaporeSingaporeSingapore

Three-dimensional(3D)organoids derived from pluripotent or adult tissue stem cells seem to possess excellent potential for studying development and disease mechanisms alongside having a myriad of applications in regenerative ***,lack of precise architectures and large-scale tissue sizes are some of the key limitations of current organoid technologies.3D bioprinting of organoids has recently emerged to address some of these *** this review,we discuss 3D bioprinting with respect to the use of bioinks and bioprinting methods and highlight recent studies that have shown success in bioprinting of stem cells and *** also summarize the use of several vascularization strategies for the bioprinted organoids,that are critical for a complex tissue *** fully realize the translational applications of organoids in disease modeling and regenerative medicine,these areas in 3D bioprinting need to be appropriately harnessed and channelized.

关键词： Three-dimensional bioprinting Bioink Organoid Microfluidics Extracellular matrix(ECM) Biomaterial

Comprehensive studies on dielectric properties of p-methoxy benzylidene p-decyl aniline with function of temperature and frequency in planar geometry: A potential nematic liquid crystal for display devices

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Chinese Physics B 2021年第6期30卷 329-333页

作者： Pankaj Kumar tripathi Kunwar Vikram Mithlesh Tiwari Ajay Shriram Department of Physics Lovely Professional UniversityPhagwara-144411PunjabIndia Department of Allied Science Graphic Era(Deemed to be university)Dehradun-248002 India Department of Physics and Electronics Dr.Ram Manohar Lohia Avadh UniversityAyodhya-224001U.P.India School of Computer Science&Information Technology Jain(Deemed-to-be-University)Bengaluru-560069KarnatakaIndia

The dielectric properties of the nematic mesophase, p-methoxy benzylidene p-decyl aniline(MBDA), measured in planar geometry with a function of frequency and temperature are investigated in detail. The complex dielectric permittivity(ε' and ε'') is also studied at a bias voltage of 10 V for planar aligned sample cell of nematic mesophase. The dielectric permittivity with bias voltage attains a higher(> 2 times) value than that without bias voltage at a temperature of 56℃,which is due to the fact that the linking group of nematic molecules is internally interacted with an applied bias *** is supported by observing an enhanced dielectric permittivity of nematic liquid crystal(LC) in the presence of bias voltage, which can be fully explained as the increasing of the corresponding dipole moment. The dielectric relaxation behaviors of nematic LC are also demonstrated for planar aligned sample cell. The remarkable results are observed that the relaxation frequency shifts into low frequency region with the increase of the bias voltage applied to the planar aligned sample cells. The dielectric relaxation spectra are fitted by Cole–Cole nonlinear curve fitting for nematic mesophase in order to determine the dielectric strength.

关键词： dielectric permittivity dielectric loss relaxation frequency nematic mesogen

Smoking under hypoxic conditions: a potent environmental risk factor for inflammatory and autoimmune diseases

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Military Medical Research 2018年第3期5卷 263-278页

作者： Md.Saddam Hussain Vishwas tripathi School of Biotechnology Gautam Buddha University

Autoimmune disease management presents a significant challenge to medical science. Environmental factors potentially increase the risk of developing inflammatory and autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and lupus. Among various environmental stresses, cigarette smoke and hypoxia have both been reported to lead to an enhanced risk of inflammatory and autoimmune diseases. In this review, we shed light on all reported mechanisms whereby cigarette smoke and a hypoxic environment can induce inflammatory and autoimmune diseases and discuss how hypoxic conditions influence the cigarette smoke-induced threat of inflammatory and autoimmune disease development. Cigarette smoke and hypoxia both lead to increased oxidative stress and production of reactive oxygen species and other free radicals, which have various effects including the generation of autoreactive pro-inflammatory T cells and autoantibodies, reductions in T regulatory(Treg) cell activity, and enhanced expression of pro-inflammatory mediators [e.g., interleukin-6(IL-6), interleukin-4(IL-4) and interleukin-8(IL-8)]. Accordingly, smoking and hypoxic environments may synergistically act as potent environmental risk factors for inflammatory and autoimmune diseases. To our knowledge, no studies have reported the direct association of cigarette smoke and hypoxic environments with the risk of developing inflammatory and autoimmune diseases. Future studies exploring the risk of autoimmune disease development in smokers at high altitudes, particularly military personnel and mountaineers who are not acclimatized to high-altitude regions, are required to obtain a better understanding of disease risk as well as its management.

关键词： Inflammatory and autoimmune diseases Cigarette smoke Hypobaric hypoxia Oxidative stress Epigenetic modifications Pro-inflammatory mediators Autoantibody