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Negative corrections to black hole entropy from string theory

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 71-76页

作者： Liang Ma yi pang Hong Lu Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

We report for the first time that in heterotic string compactified on 4-torus or equivalently IIA string compactified on K3,the leading α′corrections to the rotating black string entropy at fixed conserved charges can be negative.This further implies that the correction to the mass of extremal rotating string is positive,opposite to the standard expectation from the weak gravity conjecture.Our result suggests that the validity of positivity of entropy shift due to higher order operators depends on other factors omitted previously in the effective field theory analysis.

关键词： supergravities higher-derivative corrections effective theories black holes quantum gravity string theory

Dysregulation of neurogenesis by neuroinflammation:key differences in neurodevelopmental and neurological disorders

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Neural Regeneration Research 2017年第3期12卷 366-371页

作者： Lir-Wan Fan yi pang ackson MSUSA

Embryonic neurogenesis is the process of generating neurons,the functional units of the brain.Because of its sensitivity to adverse intrauterine environment such as infection,dysregulation of this process has emerged as a key mechanism underlying many neurodevelopmental disorders such as autism spectrum disorders（ASD）.Adult neurogenesis,although is restricted to a few neurogenic niches,plays pivotal roles in brain plasticity and repair.Increasing evidence suggests that impairments in adult neurogenesis are involved in major neurodegenerative disorders such as Alzheimer＇s disease.A hallmark feature of these brain disorders is neuroinflammation,which can either promote or inhibit neurogenesis depending upon the context of brain microenvironment.In this review paper,we present evidence from both experimental and human studies to show a complex picture of relationship between these two events,and discussed potential factors contributing to different or even opposing actions of neuroinflammation on neurogenesis in neurodevelopmental and neurological disorders.

关键词： microglia neurodegeneration autism embryonic neurogenesis adult neurogenesis cytokine aging

Degenerate black rings in D=5 minimal supergravity

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Science China(Physics,Mechanics & Astronomy) 2021年第11期64卷 44-56页

作者： Shi-Fa Guo Hong Lu yi pang Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China

We consider both gauged and ungauged minimal supergravities in five dimensions and analyse the charged rotating solutions with two equal angular momenta J.When the electric charge Q∼J^(2/3) with some specific coefficient,we find new extremal black objects emerge that are asymptotic to either Minkowski or global AdS spacetimes and can be best described as degenerate black rings.Their near-horizon geometry is locally AdS3×S^(2),where the periodic U(1)fibre coordinate in S 3 untwists and collapses to be the degenerate part of the AdS3 horizon.It turns out that there are two branches of extremal rotating black holes,starting as the extremal RN black holes of the same mass,but opposite charges.With the increasing of the angular momentum,they will join to become the same degenerate black ring,where the Gibbs free energies however are not continuous at the joining.For the same Q(J)relation,we find that there is in addition a rotating soliton whose mass is smaller than that of the degenerate black ring.

关键词： supergravity higher-dimensional gravity black holes black rings thermodynamics

Strategies for myelin regeneration: lessons learned from development

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Neural Regeneration Research 2014年第14期9卷 1347-1350页

作者： Abhay Bhatt Lir-Wan Fan yi pang Department of Pediatrics Division of Newborn MedicineUniversity of Mississippi Medical CenteracksonMSUSA

Myelin regeneration is indispensably important for patients suffering from several central nervous system （CNS） disorders such as multiple sclerosis （MS） and spinal cord injury （SCI）, because it is not only essential for restoring neurophysiology, but also protects denuded axons for secondary degeneration. Understanding the cellular and molecular mechanisms underlying remyelination is critical for the development of remyelination-specific therapeutic approaches. As remyelination shares certain common mechanisms with developmental myelination, knowledge from study of developmental myelination contributes greatly to emerging myelin regeneration therapies, best evidenced as the recently developed human anti-Nogo receptor interacting protein-1 （LINGO-1） monoclonal antibodies to treat MS patients in clinical trials.

关键词： oligodendrocyte myelination microglia multiple sclerosis white matter damage spinalcord injury

Rapid transport of insulin to the brain following intranasal administration in rats

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Neural Regeneration Research 2019年第6期14卷 1046-1051页

作者： Lir-Wan Fan Kathleen Carter Abhay Bhatt yi pang Department of Pediatrics University of Mississippi Medical Center

We previously reported that intranasal insulin protects substantia nigra dopaminergic neurons against6-hydroxydopamine neurotoxicity in rats. This study aimed to assess insulin pharmacokinetics in the rat brain following intranasal application. Recombinant human insulin(rh-Ins) or phosphate buffer solution was administered to both nostrils of rats. Animals were sacrificed at 15 minutes, 1, 2, and 6 hours to determine insulin levels in different brain regions by an ultrasensitive, human-specific enzyme-linked immunosorbent assay kit. For fluorescence tracing study, rats were administered with intranasal florescence-tagged insulin(Alex546-Ins), and brains were fixed at 10 and 30 minutes to prepare sagittal sections.rh-Ins was detected in all brain regions examined except the cerebral cortex. The highest levels were detected in the brainstem, followed by the cerebellum, substantia nigra/ventral tegmental area, olfactory bulb,striatum, hippocampus, and thalamus/hypothalamus. Insulin levels reached a peak at 15 minutes and then declined gradually overtime, but remained significantly higher than baseline levels at 6 hours in most regions.Consistently, widespread Alex546-Ins-binding cells were detected in the brain at 10 and 30 minutes, with the olfactory bulb and brainstem showing the highest while the cerebral cortex showing lowest fluorescence signals. Double-immunostaining showed that Alex546-Ins-bindings were primarily co-localized with neuronal nuclei-positive neurons. In the subtantia nigra, phospho-Akt was found to be activated in a subset of Alex546-Ins and tyrosine hydroxylase double-labeled cells, suggesting activation of the Akt/PI3 K pathway in these dopaminergic neurons. Data from this study suggest that intranasal insulin could effectively reach deep brain structures including the nigrostriatal pathways, where it binds to dopaminergic neurons and activates intracellular cell survival signaling. This study was approved by the Institutional Animal Care Committee at the University of Mississippi Medical Cent

关键词： dopaminergic neurons striatum substantia nigra brainstem olfactory bulb glia trigeminal nerve pharmacokinetics axonal transport pAkt

Traumatic brain injury induced by exposure to blast overpressure via ear canal

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Neural Regeneration Research 2022年第1期17卷 115-121页

作者： Yang Ou Brad AClifton Jinghui Li David Sandlin Na Li Li Wu Chunming Zhang Tianwen Chen Jun Huang Yue Yu Jerome Allison Fan Fan Richard JRoman James Shaffery Wu Zhou yi pang Hong Zhu Departmant of Otolaryngology and Head Neck Surgery Department of Neurobiology and Anatomical Sciences MD Program School of Medicine Graduate Program in Neuroscience Department of Pediatrics Department of Pharmacology and Toxicology Department of Psychiatry and Human Behavior University of Mississippi Medical CenterJacksonMSUSA Kunming Medical University KunmingYunnan ProvinceChina Department of Otolaryngology First Affiliated HospitalShanxi Medical UniversityTaiyuanShanxi ProvinceChina

Exposure to explosive shockwave often leads to blast-induced traumatic brain injury in military and civilian populations.Unprotected ears are most often damaged following exposure to blasts.Although there is an association between tympanic membrane perforation and TBI in blast exposure victims,little is known about how and to what extent blast energy is transmitted to the central nervous system via the external ear canal.The present study investigated whether exposure to blasts directed through the ear canal causes brain injury in LongEvans rats.Animals were exposed to a single blast(0–30 pounds per square inch(psi))through the ear canal,and brain injury was evaluated by histological and behavioral outcomes at multiple time-points.Blast exposure not only caused tympanic membrane perforation but also produced substantial neuropathological changes in the brain,including increased expression of c-Fos,induction of a profound chronic neuroinflammatory response,and apoptosis of neurons.The blast-induced injury was not limited only to the brainstem most proximal to the source of the blast,but also affected the forebrain including the hippocampus,amygdala and the habenula,which are all involved in cognitive functions.Indeed,the animals exhibited long-term neurological deficits,including signs of anxiety in open field tests 2 months following blast exposure,and impaired learning and memory in an 8-arm maze 12 months following blast exposure.These results suggest that the unprotected ear canal provides a locus for blast waves to cause TBI.This study was approved by the Institutional Animal Care and Use Committee at the University of Mississippi Medical Center(Animal protocol#0932 E,approval date:September 30,2016 and 0932 F,approval date:September 27,2019).

关键词： anxiety blast ear ear protection learning memory microglia neuroinflammation neuron rat traumatic brain injury

Clinical evaluation of surgery-induced astigmatism in cataract surgery using 2.2 mm or 1.8 mm clear corneal micro-incisions

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International Journal of Ophthalmology(English edition) 2017年第1期10卷 68-71页

作者： Jun Yang Xiu Wang Hong Zhang yi pang Rui-Hua Wei Comea&Refractive surgery Tianjin Medical University Eye HospitalTianjin 300384China Cataract Surgery Tianjin Medical University Eye HospitalTianjin 300384China Associate Dean for Research Illinois College of Optometry3241 SMichigan AveChicagoIL 60616USA

AIM： To evaluate corneal astigmatism after phacoemulsification using 2.2 mm or 1.8 mm clear corneal micro-incisions and its effects on visual function.METHODS： Sixty cases （60 eyes） with cataract were randomly divided into groups A （n=30） and B （n=30） respectively underwent 2.2 mm and 1.8 mm clear corneal tunnel incision phacoemulsification combined with folding intraocular lens implantation from the time direction of 11：00. On day 1 and at 1, 4, and 6wk after operation, patients’ vision was measured and both the corneal curvature and corneal thickness （CT） were recorded using Pentacam.RESULTS： The measured surgery-induced astigmatism （SIA） in both groups A and B peaked on day 1 after operation, and then gradually decreased and eventually stabilized in week 4. No statistically significant difference was found in corneal astigmatism between two groups （P〉0.05）. The measured corneal astigmatism at 4wk and 6wk postoperatively were 0.28±0.09 D and 0.27±0.10 D for groups A and 0.27±0.09 D and 0.25±0.10 D for groups B without statistically significant difference （P〉0.05）. In addition, no significant differences in visual acuity and CT were found between groups A and B before or after operation.CONCLUSION： Both 2.2 mm and 1.8 mm micro-incision cataract surgeries result in relatively small SIA with no difference in visual function and corneal astigmatism between two surgery approaches. Thus, the two types of surgical systems are safe and efficient for cataract treatment, by which satisfactory uncorrected visual acuity can be regained early postoperatively.

关键词： surgery-induced astigmatism corneal astig-matism phacoemulsification

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设计流速对管道灌溉系统年费用的影响

节水灌溉 2024年第2期 83-87,104页

作者：庞懿元汤攀李红梁琪赵晶江苏大学流体机械工程技术研究中心江苏镇江212013

管道输水灌溉作为智慧农业的重要组成部分,高昂的建设和运行费用限制了其推广。在水头损失、灌溉时长和管径选择的约束下,建立了灌溉年费用优化模型,在2.0~5.0 m/s的流速区间内,以步长0.1 m/s进行年费用优化,探究设计流速对灌溉年费用... 详细信息

管道输水灌溉作为智慧农业的重要组成部分,高昂的建设和运行费用限制了其推广。在水头损失、灌溉时长和管径选择的约束下,建立了灌溉年费用优化模型,在2.0~5.0 m/s的流速区间内,以步长0.1 m/s进行年费用优化,探究设计流速对灌溉年费用的影响。另外,针对传统遗传算法收敛不稳定的情况,对算法进行了结构调整,舍弃交叉算子的同时设计了双重选择算子和并行变异算子,提高了算法的鲁棒性。结果表明,在2.0~2.7 m/s的设计流速区间内,灌溉年费用随着设计流速的增加而逐渐降低,灌溉费用节约率可达7.2%;而当流速大于2.7 m/s时,进一步提高流速约束对灌溉年费用并没有实质性影响。上述结论为设计流速的选择提供了理论参考,对降低灌溉费用具有积极效果。

关键词：管道灌溉设计流速管网费用运行能耗遗传算法

基于GIS的和静县—轮台县重要区域崩塌易发性评价

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西部探矿工程 2024年第4期36卷 1-5,9页

作者：陈君庞义杰新疆地矿局第三地质大队新疆库尔勒841000

针对新疆轮台县—和静县地质灾害重要区域地质构造运动复杂、崩塌灾害频发的现象。在高精度遥感数据解译、InSAR变形监测的基础上,辅以无人机三维倾斜摄影、物探、钻探、山地工程、试验等工作手段对新疆轮台县—和静县重要区域崩塌灾害... 详细信息

针对新疆轮台县—和静县地质灾害重要区域地质构造运动复杂、崩塌灾害频发的现象。在高精度遥感数据解译、InSAR变形监测的基础上,辅以无人机三维倾斜摄影、物探、钻探、山地工程、试验等工作手段对新疆轮台县—和静县重要区域崩塌灾害进行了1∶1万精度调查,在对区内崩塌灾害的形成机理及成灾模式进行分析后,选取了距断裂距离、距水系距离、距道路距离、工程岩组、坡向、坡度和高程等7个影响因子作为评价因子,利用Arcgis空间分析功能对7个因子进行相关性分析,最终选取距断裂距离、距道路距离、工程岩组、坡向、坡度和高程等6个相互独立的因子作为评价指标,并选取栅格单元作为基础评价单元对其进行信息量计算,构建信息量模型对研究区崩塌灾害的易发性进行评价与区划。结果表明:高易发区占地面积约3612.97km^(2),占21.06%;中易发区面积约5109.70km^(2),占29.78%;低易发区面积约4909.44km^(2),占28.61%;非易发区面积约3525.35km^(2),占20.55%。评价结果与野外调查基本吻合,可为研究区的防灾减灾管理、国土空间规划和用途管制、新农村和重点工程规划建设服务等提供基础依据。

关键词：崩塌影响因素评价指标信息量易发性评价