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Tidal force effects and bound orbits in null naked singularity spacetime

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Chinese physics C 2024年第11期48卷 193-202页

作者： Siddharth Madan parth Bambhaniya p.d.patel institute of applied sciences Charusat UniversityAnand-388421GujaratIndia International Centre for Space and Cosmology School of Arts and SciencesAhmedabad UniversityAhmedabad 380009GujaratIndia

Naked singularities form during the gravitational collapse of inhomogeneous matter *** final nature of the singularity depends on the initial conditions of the matter properties and types of matter *** naked singularities can also be divided into two types:null-like and timelike *** spacelike singularity of the Schwarzschild black hole can be distinguished from the null and timelike naked singularity *** light of this,we investigate the precession of timelike bound orbits in the null naked singularity spacetime,as well as tidal force effects and geodesic deviation *** a result,we find that the orbital precession of the timelike bound orbits in null naked singularity spacetime could be distinguished from the Schwarzschild precession *** radial component of the tidal force has an intriguing profile,whereas the angular component has a profile that is comparable to that of a Schwarzschild black hole *** geodesic deviation equation is then solved numerically,yielding results that resemble Schwarzschild black *** characteristic features can then be used to discern among these singularities.

关键词： black hole naked singularity tidal force bound orbits

Cosmic acceleration with bulk viscosity in an anisotropic f(R, Lm) background

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Communications in Theoretical physics 2023年第7期75卷 103-112页

作者： Raja Solanki Bina patel Lakhan V Jaybhaye p K Sahoo department of Mathematics Birla Institute of Technology and Science-PilaniHyderabad CampusHyderabad-500078India department of Mathematical sciences P.D.Patel Institute of Applied SciencesCharotar University of Science and Technology(CHARUSAT)ChangaAnand 388421GujaratIndia

In this article,we investigate the observed cosmic acceleration in the framework of a cosmological f(R,Lm)model dominated by bulk viscous matter in an anisotropic *** consider the locally rotationally symmetric Bianchi type I metric and derive the Friedmann equations that drive the gravitational interactions in f((R,Lm)***,we assume the functional form f(R,Lm)=R/2+Lαm,where a is a free model parameter,and then find the exact solutions of field equations corresponding to our viscous matter dominated *** incorporate the updated H(z)data and the pantheon data to acquire the best-fit values of parameters of our model by utilizing theχ2 minimization technique along with the Markov Chain Monte Carlo random sampling ***,we present the behavior of physical parameters that describe the Universe’s evolution phase,such as density,effective pressure and EoS parameters,skewness parameter,and the statefinder diagnostic *** find that the energy density indicates expected positive behavior,whereas the negative behavior of bulk viscous pressure contributes to the Universe’s *** effective EoS parameter favors the accelerating phase of the Universe’s ***,the skewness parameter shows the anisotropic nature of spacetime during the entire evolution phase of the ***,from the statefinder diagnostic test,we found that our cosmological f(R,Lm)model lies in the quintessence region,and it behaves like a de-Sitter universe in the far *** analyze different energy conditions in order to test the consistency of the obtained *** find that all energy conditions except strong energy condition(SEC)show positive behavior,while the violation of SEC favors the recently observed acceleration with the transition from decelerated to an accelerated epoch of the Universe’s expansion in the recent past.

关键词： LRS Bianchi type I metric f(R Lm)gravity bulk viscosity skewness parameter equation of state parameter statefinder parameter

Enhanced Antibacterial Activity of Bifunctional Fe_(3)O_(4)-Ag Core-Shell Nanostructures

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Nano Research 2009年第12期2卷 955-965页

作者： Bhupendra Chudasama Anjana K.Vala Nidhi Andhariya R.V.Upadhyay R.V.Mehta department of applied physics S.V.National Institute of TechnologySurat 395007India department of physics Bhavnagar UniversityBhavnagar 364022India p.d.patel institute of applied sciences Charotar University of Science and TechnologyEducation campusChanga 388421India

We describe a simple one-pot thermal decomposition method for the production of a stable colloidal suspension of narrowly dispersed superparamagnetic Fe_(3)O_(4)-Ag core-shell *** biocompatible nanostructures are highly toxic to *** activity studies were carried out on both Gram negative(Escherichia coli and proteus vulgaris)and Gram positive(Bacillus megaterium and Staphylococcus aureus)bacterial *** have been made to understand the underlying molecular mechanism of such antibacterial *** effect of the core-shell nanostructures on Gram negative strains was found to be better than that observed for silver *** minimum inhibitory concentration(MIC)values of these nanostructures were found to be considerably lower than those of commercially available *** attribute this enhanced antibacterial effect of the nanostructures to their stability as a colloid in the medium,which modulates the phosphotyrosine profile of the bacterial proteins and arrests bacterial *** also demonstrate that these core-shell nanostructures can be removed from the medium by means of an external magnetic field which provides a mechanism to prevent uncontrolled waste disposal of these potentially hazardous nanostructures.

关键词： Core-shell nanostructure antimicrobial activity minimum inhibitory concentration phase transfer

dendritic macromolecules as nano-scale drug carriers:phase solubility,in vitro drug release,hemolysis and cytotoxicity study

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Asian Journal of pharmaceutical sciences 2015年第4期10卷 306-313页

作者： pravinkumar M.patel Rinkesh patel devang Wadia Rajni M.patel Industrial Chemistry department V.P.&R.P.T.P.Science CollegeAffiliated to Sardar Patel UniversityVallabh VidhyanagarGujaratIndia Nirlife Healthcare division Nirma LimitedAhmedabadGujaratIndia p.d.patel institute of pure and applied sciences Charusat UniversityChangaGujaratIndia

potential of nanoscale triazine based dendritic macromolecules G1,G2 and G3 as solubility enhancers of drug was *** of pH,concentration and generation of synthesized dendritic macromolecules on solubility of ketoprofen was studied.G3 dendrimer was further exploited as carrier for sustained *** was encapsulated by inclusion complex method and also characterized by Flourier Transform Infrared *** release study of ketoprofen from ketoprofen loaded dendrimer was carried out and compared with free *** potential and Cytotoxicity assay using A-549 lung cancer cell lines revealed that synthesized triazine based dendritic macromolecules having more potential that commercially available pAMAM dendrimer.

关键词： Triazine based dendrimer Ketoprofen drug carrier Cytotoxicity Hemolysis

Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

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Neural Regeneration Research 2025年第6期20卷 1721-1734页

作者： Xirong Xu Shoumin Xuan Shuai Chen dan Liu Qian Xiao Jie Tu Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological diseases Shenzhen-Hong Kong Institute of Brain ScienceShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina CAS Key Laboratory of Brain Connectome and Manipulation Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina Guangdong provincial Key Laboratory of Brain Connectome and Behavior the Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina University of Chinese of Academy of sciences BeijingChina Faculty of Life and Health sciences Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with ***, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1d promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal *** knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was ob

关键词： anxiety astrocytes basolateral amygdala behavior dihydrokainic acid excitatory amino acid transporter 2 fiber photometry glutamate LdN-212320 transporter

A new horizon for neuroscience:terahertz biotechnology in brain research

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Neural Regeneration Research 2025年第2期20卷 309-325页

作者： Zhengping pu Yu Wu Zhongjie Zhu Hongwei Zhao donghong Cui Shanghai Key Laboratory of psychotic disorders Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina department of psychiatry Kangci Hospital of JiaxingTongxiangZhejiang ProvinceChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina Key Laboratory of Interfacial physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of ScienceShanghaiChina National Facility for protein Science in Shanghai Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina

Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain *** this article,we review the development of terahertz biotechnology and its applications in the field of *** evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin *** vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric *** the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic ***,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical *** review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.

关键词： biological effect brain neuron neuropsychiatry neuroscience non-thermal effect terahertz imaging terahertz radiation terahertz spectroscopy terahertz technology

Tale of mitochondria and mitochondria-associated ER membrane in patient-derived neuronal models of Wolfram syndrome

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Neural Regeneration Research 2025年第9期20卷 2587-2588页

作者： Laetitia Aubry Timothy Barrett Sovan Sarkar I-STEM CECSCorbeil-EssonnesFrance Universitéparis-Saclay Universitéd’EvryINSERMI-STEMUMR861Corbeil-EssonnesFrance institute of Cancer and Genomic sciences Institute of Biomedical ResearchCollege of Medical and Dental SciencesUniversity of BirminghamEdgbastonBirminghamUK department of Endocrinology Birmingham Women’s and Children’s HospitalSteelhouse LaneBirminghamUK

Mitochondria and mitochondria-associated endoplasmic reticulum membrane in neurodegenerative diseases:Mitochondria generate most of the chemical energy needed to power the biochemical reactions of cells,and thus are often referred to as the"powerhouse"of the ***,this organelle is also involved in a pleth,ora of different cellular functions such as calcium(Ca^(2+))homeostasis,apoptosis,oxidative stress,and several metabolic pathways including oxidative phosphorylation,tricarboxylic acid cycle,andβ-oxidation of fatty acids.

关键词： oxidative cycle carboxylic

Einstein probe discovery of Ep240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda Zhang Weimin Yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin dai Jingwei Hu Shumei Jia Chichuan Jin dongyue Li paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng Wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang Yonghe Zhang Jie An david Buckley Alexis Coleiro Bertrand Cordier Liming dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan p.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen Wu Xuefeng Wu dong Xu Yanjun Xu Suijian Xue Yongquan Xue Zijian Zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng dai dongwei Fan Ju Guan dawei Han dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu pan Xin pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu National Astronomical Observatories Chinese Academy of sciences School of Astronomy and Space sciences University of Chinese Academy of sciences Key Laboratory of particle Astrophysics institute of High Energy physics Chinese Academy of sciences institute of Space sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max planck institute for Extraterrestrial physics Innovation Academy for Microsatellites Chinese Academy of sciences department of physics University of Hong Kong School of physics and Astronomy University of Leicester School of physics and Astronomy Sun Yat-sen University department of physics Anhui Normal University Shanghai institute of Technical physics Chinese Academy of sciences physics department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas department of physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory department of Astronomy University of Cape Town department of physics University of the Free State Université paris Cité CNRS Astroparticule et Cosmologie Université paris Cité CEA paris-Saclay IRFU/dAp-AIM department of Astronomy Guangzhou University Cosmic dawn Center (dAWN) Niels Bohr institute University of Copenhagen department of physics and Astronomy Rutgers the State University of New Jersey institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC department of Astronomy School of physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney institute for Astronomy School of physics The University of Sydney department of Astronomy Xiamen University institute for Frontiers in Astronomy and Astrophysics Beijing Normal University department of Astronomy University of Science and Technology School of Astronomy and Space sciences University of Science and Technology of China institute of deep Space sciences deep Space Exploration Laboratory department of Astronomy School of physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

We report the discovery of a peculiar X-ray transient,Ep240408a,by Einstein probe （Ep） and follow-up studies made with Ep,Swift,NICER,GRONd,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board Ep on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by Ep/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous Ep observations,an unusual timescale in the range of 7-23 d is found for Ep240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of Ep240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of Ep240408a thus remains an *** suggest that Ep240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~probe}}$

Feasibility of Solar Tracking System for pV panel in Sunbelt Region

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Journal of Modern power Systems and Clean Energy 2021年第2期9卷 395-403页

作者： Soulayman Soulayman Mohamad Hamoud Mohamad-Amir Hababa Wassim Sabbagh the department of applied physics Higher Institute for Applied Sciences and TechnologyDamascusP O Box 31983Syria

In the study of the feasibility of solar tracking systems for crystalline silicon photovoltaic(pV)panels in hot and cold regions,it is argued recently that a tracking system is not necessary for sunbelt countries owing to the overheating that results from excessive exposure to solar *** conclusion has been formulated based on a mathematical model,which in turn is based on the assumption that the pV module temperature can be calculated using an empirical relation of this temperature to ambient temperature,available solar irradiance,and nominal operation cell temperature(NOCT).To support this conclusion,it is claimed that the mathematical model is validated ***,this assumption is vague and widely used in the *** objective of the present work is to reevaluate the above-mentioned assumption and to discuss the results deriving from *** is shown experimentally in the present work that the above-mentioned assumption overestimates the pV module *** a solar irradiance of 900 W/m2,ambient temperature of 25℃,and wind speed of 5 m/s,the measured pV module temperature is lower than the value calculated based on the mentioned assumption by 29.26%.

关键词： photovoltaic(pV)module temperature wind speed influence pV module efficiency experimental verification damascus clear-sky conditions