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86% TMR at 4.2 K for Amorphous Magnetic-Tunnel-Junctions with Co_(60)Fe_(20)B_(20) as Free and Pinned Layers

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Journal of Materials Science & Technology 2005年第3期21卷 289-291页

作者： Rehana sharif State Key Laboratory of Magnetism Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Single barrier magnetic-tunnel-junctions (MTJs) with the layer structure of Ta(5)/Cu(30)/Ta(5)/Ni79Fe21(5)/Ir22 Mn78(12)/Co60Fe20B20(4)/Al(0.8)-oxide/Co60Fe20B20(4)/Cu(30)/Ta(5) [thickness unit: nm] using the amorphous Co60Fe20B20 alloy as free and pinned layers were micro-fabricated. The experimental investigations showed that the tunnel magnetoresistance (TMR) ratio and the resistance decrease with increasing dc bias voltage from 0 to 500 mV or with increasing temperature from 4.2 K to RT. A high TMR ratio of 86.2% at 4.2 K, which corresponds to the high spin polarization of Co60Fe20B20, 55%, was observed in the MTJs after annealing at 270℃ for 1 h. High TMR ratio of 53.1%, low junction resistance-area product RS of 3.56 kΩμm2, small coercivity HC of ≤4 Oe, and relatively large bias-voltage-at-half-maximum TMR with the value V1/2 of greater than 570 mV at RT have been achieved in such Co-Fe-B MTJs.

关键词： Tunnel magnetoresistance Magnetic tunnel junction Spin-polarization MRAM Co60Fe20B20

Neuroaxonal and cellular damage/protection by prostanoid receptor ligands,fatty acid derivatives and associated enzyme inhibitors

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Neural Regeneration Research 2023年第1期18卷 5-17页

作者： Najam A.sharif Department of Pharmaceutical Sciences College of Pharmacy and Health SciencesTexas Southern UniversityHoustonTXUSA Department of Pharmacology and Neuroscience University of North Texas Health Sciences CenterFort WorthTXUSA Department of Pharmacy Sciences School of Pharmacy and Health ProfessionsCreighton UniversityOmahaNEUSA Singapore Eye Research Institute(SERI) SingaporeSingapore Duke-NUS Medical School SingaporeSingapore Department of Surgery&Cancer Imperial College of Science and TechnologySt.Mary’s CampusLondonUK Global Alliances and External Research Ophthalmology Innovation CenterSanten Inc USAEmeryvilleCAUSA

Cellular and mitochondrial membrane phospholipids provide the substrate for synthesis and release of prostaglandins in response to certain chemical,mechanical,noxious and other *** D_(2),prostaglandin E_(2),prostaglandin F_(2)α,prostaglandin I_(2)and thromboxane-A_(2)interact with five major receptors(and their sub-types)to elicit specific downstream cellular and tissue *** general,prostaglandins have been associated with pain,inflammation,and edema when they are present at high local concentrations and involved on a chronic ***,in acute settings,certain endogenous and exogenous prostaglandins have beneficial effects ranging from mediating muscle contraction/relaxation,providing cellular protection,regulating sleep,and enhancing blood flow,to lowering intraocular pressure to prevent the development of glaucoma,a blinding *** classes of prostaglandins are implicated(or are considered beneficial)in certain central nervous system dysfunctions(e.g.,Alzheimer’s,Parkinson’s,and Huntington’s diseases;amyotrophic lateral sclerosis and multiple sclerosis;stroke,traumatic brain injuries and pain)and in ocular disorders(e.g.,ocular hypertension and glaucoma;allergy and inflammation;edematous retinal disorders).This review endeavors to address the physiological/pathological roles of prostaglandins in the central nervous system and ocular function in health and disease,and provides insights towards the therapeutic utility of some prostaglandin agonists and antagonists,polyunsaturated fatty acids,and cyclooxygenase inhibitors.

关键词： AL-8810 axon brain central nervous system cyclooxygenase inhibitors neuron neuroprotection ocular polyunsaturated fatty acids prostaglandins

Leber's congenital amaurosis and the role of gene therapy in congenital retinal disorders

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International Journal of Ophthalmology(English edition) 2017年第3期10卷 480-484页

作者： Walid sharif Zuhair sharif Department of Ophthalmology Birmingham & Midland Eye Centre City Hospital NHS Trust Birmingham B 18 7QH UK Institute of Ophthalmology University College London 11-43 Bath St London EC1V 9EL UK

Leber＇s congenital amaurosis（LCA）and recent gene therapy advancement for treating inherited retinopathies were extensive literature reviewed using MEDLINE,Pub Med and EMBASE. Adeno-associated viral vectors were the most utilised vectors for ocular gene therapy. Cone photoreceptor cells might use an alternate pathway which was not reliant of the retinal pigment epithelium（RPE）derived retinoid isomerohydrolase（RPE65）to access the 11-cis retinal dehydechromophore. Research efforts dedicated on the progression of a gene-based therapy for the treatment of LCA2. Such gene therapy approaches were extremely successful in canine,porcine and rodent LCA2 models. The recombinant AAV2.h RPE65v2 adenoassociated vector contained the RPE65 cDNA and was replication deficient. Its in vitro injection in target cells induced RPE65 protein production. The gene therapy trials that were so far conducted for inherited retinopathies have generated promising results. Phase I clinical trials to cure LCA and choroideremia demonstrated that adeno-associated viral vectors containing RPE genes and photoreceptors respectively,could be successfully administered to inherited retinopathy patients. A phase III trial is presently ongoing and if successful,it will lead the way to additional gene therapy attempts to cure monogenic,inherited retinopathies.

关键词： retina Leber's congenital amaurosis Leber's congenital amaurosis type 2 choroideremia achromatopsia cyclic nucleotide gated channel alpha 3 retinoid isomerohydrolase gene therapy

Glaucomatous optic neuropathy treatment options:the promise of novel therapeutics,techniques and tools to help preserve vision

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Neural Regeneration Research 2018年第7期13卷 1145-1150页

作者： Najam A.sharif Department of Global Alliances & External Research Global Ophthalmology Research & DevelopmentSanten Incorporated Department of Pharmaceutical Sciences Texas Southern University Department of Pharmacology and Neuroscience University of North Texas Health Sciences Center Department of Pharmacy Sciences Creighton University Department of Surgery & Cancer Imperial College of Science and TechnologySt.Mary's Campus

Peripheral vision loss followed by ＂tunnel vision＂ and eventual irreversible blindness is the fate of patients afflicted by various forms of glaucoma including primary open-angle glaucoma（POAG） and normotensive glaucoma（NTG）.These complex and heterogeneous diseases are characterized by extensive death of retinal ganglion cells（RGCs） accompanied by retraction and severance of their axonal connections to the brain and thus damage to and thinning of the optic *** patients suffering from this glaucomatous optic neuropathy（GON） first notice visual impairment when they have lost 〉 40% of their RGCs,early diagnosis is the key to retard the progression of *** intraocular pressure（IOP）,low cerebrospinal and/or low intracranial fluid pressure,advancing age,and ethnicity are major risk factors associated with ***,retinal vascular abnormalities and a high sensitivity of RGCs and optic nerve head components to neurotoxic,inflammatory,oxidative and mechanical insults also contribute to vision loss in POAG/*** treatment modalities for POAG and NTG involve lowering IOP using topical ocular drugs,combination drug products,and surgical *** recently approved multi-pharmacophoric drugs（e.g.,rho kinase inhibitor,Netarsudil;a drug conjugate,Latanoprostene Bunod） and novel aqueous humor drainage devices（i Stent and Cy Pass） are also gaining acceptance for treating POAG/*** and regenerative agents,coupled with electroceutical,mechanical support systems,stem cell transplantation and gene therapy are emerging therapeutics on the horizon to help combat *** latter techniques and approaches hope to rejuvenate RGCs and repair the optic nerve structures,thereby providing a gain of function of the visual system for the glaucoma patients.

关键词： glaucoma ocular hypertension glaucomatous optic neuropathy drainage device optic nerve degeneration retinal ganglion cells nerve regeneration neuroprotection

CO_x-Free Hydrogen and Carbon Nanofibers Produced from Direct Decomposition of Methane on Nickel-Based Catalysts

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Journal of Natural Gas Chemistry 2006年第4期15卷 253-258页

作者： Siang-Piao Chai sharif Hussein sharif Zein Abdul Rahman Mohamed School of Chemical Engineering Universiti Sains MalaysiaEngineering Campus Seri Ampangan14300 Nibong TebalSPS Penang Malaysia

Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, CuO, FeO, MnOx and MoO） in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiOx support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8：2 （w/w） since the highest yield of hydrogen was obtained over this catalyst.

关键词： methane decomposition hydrogen carbon nanofibers supported catalyst

Phantom Accretion onto the Schwarzschild de-Sitter Black Hole

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Chinese Physics Letters 2011年第9期28卷 34-37页

作者： M sharif G Abbas Department of Mathematics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

We deal with phantom energy accretion onto the Schwarzschild de-Sitter black *** energy flux conservation,relativistic Bernoulli equation and mass flux conservation equation are formulated to discuss the phantom *** discuss the conditions for critical *** is found that the mass of the black hole decreases due to phantom *** exist two critical points which lie in the exterior of horizons(black hole and cosmological horizons).The results for the phantom energy accretion onto the Schwarzschild black hole can be recovered by takingΛ→0.

关键词： accretion horizon black

Symmetries of Energy-Momentum Tensor： Some Basic Facts

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Communications in Theoretical Physics 2007年第5期47卷 829-834页

作者： M.sharif TariqIsmaeel Department of Mathematics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

It has been pointed out by Hall et al. [Gen. Rel. Gray. 28 （1996） 299.] that matter collineations can be defined by using three different methods. But there arises the question whether one studies matter collineations by using LεTab=0, or LεT^ab = 0 or LεT^b a=0. These alternative conditions are, of. course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition.

关键词： symmetries energy-momentum tensor

Anisotropic extensions of isotropic Finch–Skea metric in the charged modified gravity

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Communications in Theoretical Physics 2024年第9期76卷 118-140页

作者： Tayyab Naseer M sharif Department of Mathematics and Statistics The University of Lahore1-Km Defence RoadLahore 54000Pakistan

In this study,we explore the Finch–Skea perfect fluid solution and extend its domain to three distinct anisotropic interior models within the framework of the f(R,T)theory,incorporating the influence of an electromagnetic *** assume a static spherical spacetime initially coupled with an isotropic matter *** then introduce a Lagrangian corresponding to an additional gravitating source,taking into account its role in inducing pressure anisotropy within the original fluid *** deriving the field equations for the combined matter setup,we applied a radial component transformation,which yielded two distinct systems of *** addition,we consider a charged exterior spacetime to determine the three constants associated with the Finch–Skea solution at the *** findings suggest that under certain parametric choices,all three resulting models exhibited physical relevance within this modified theory.

关键词： anisotropy modified gravity gravitational decoupling

Static Axially Symmetric Models and Structure Scalars in Self-Interacting Brans–Dicke Gravity

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Communications in Theoretical Physics 2017年第7期67卷 39-48页

作者： M. sharif Rubab Manzoor Department of Mathematics University of the Punjab Quaid-e-Azam Campus Lahore-54590 Pakistan Department of Mathematics University of Management and Technology Johar Town Campus Lahore-54782 Pakistan

This paper investigates static axially symmetric models in self-interacting Brans-Dicke gravity. We discuss physically feasible sources of models, derive field equations as well as evolution equations from Bianchi identities and construct structure scalars. Using these scalars and evolution equations, the inhomogeneity factors of the system are evaluated. It is found that structure scalars related to double dual of Riemann tensor control the density inhomogeneity. Finally, we obtain exact solutions of homogenous isotropic and inhomogeneous anisotropic spheroid models. It turns out that homogenous solutions reduce to Schwarzschild type interior solutions for a spherical case. We conclude that homogenous models involve homogenous distribution of scalar field whereas inhomogeneous correspond to inhomogeneous sca/ar field.

关键词： self-interacting Brans Dicke Theory self-gravitating systems structure scalars Non-sphericalsources interior solutions