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Understanding DC Partial Discharge:recent Progress,Challenges,and Outlooks

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CSEE Journal of Power and Energy Systems 2022年第3期8卷 894-909页

作者： Chuanyang Li Tohid Shahsavarian Mohamadreza Arab Baferani Kerry davis Yang Cao Di Zhang Electrical and Computer Engineering University of Connecticut371 Fairfield WayStorrsCT 06269USA Naval Postgraduate School MontereyCA 93943USA

As a non-destructive local gas breakdown phenomenon within a surface or bulk cavity surrounded by insulation,partial discharge(PD)contains important information which can be used to evaluate and diagnose electrical insulation *** this paper,distinctive characteristics of PD for DC versus AC are reviewed.A summary of experimental studies on DC PD in different insulation coordinations is presented,including PD in gaseous insulating media,PD in solid insulating media and PD in liquid insulating *** and some thoughts based on existing studies are provided,and challenges and suggestions for future studies are *** paper can serve as a guide reference for readers to learn the background and state-of-the-art of DC PD *** importantly,it is hopeful that this study can inspire novel ideas for further advancing fundamental research of DC PD mechanisms and PD mitigation methods.

关键词： Charge injection DC power systems partial discharges surface charging

Case studies of earthquake-induced effects on concrete channels

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Earthquake Science 2010年第1期23卷 63-69页

作者： Craig A davis Jianping Hu Jean-Pierre Bardet Los angeles Department of Water andPower Los Angeles CA 90012 USA Civil and Environmental Engineering Department University of Southern California Los Angeles CA 90089 USA

Case studies are presented for two concrete lined channels shaken by strong ground motions during the 1994 Northridge earthquake, the high speed channel （HSC） and bypass channel （BC）, on the Los angeles Department of Water and Power＇s Van Norman Complex. Performances of these two channels as they pass through different subsurface materials identify several important seismic aspects and the critical role of geotechnical earthquake engineering in assessing channel behaviors. Preliminary evaluations using detailed mapping of channel cracks, permanent ground movements, subsurface profiles, and nearby strong ground motion recordings from the 1994 earthquake show that the channel liners may have been damaged from both transient motions and permanent ground movements. Damage from permanent ground deformations is obvious by observation; therefore simplified analyses are presented only for transient movements. Site specific transient response analyses are performed to provide an initial assessment of the differing effects from transient and permanent ground movements on HSC and BC liner damage. These case studies are helpful for introducing the potential for lifeline damage from transient movements within zones of permanent ground movement, a concept not well understood in the earthquake engineering community

关键词： concrete channel ground motion ground deformation transient movement lifeline

Incidence and outcomes of intracerebral haemorrhage with mechanical compression hydrocephalus

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Stroke & Vascular Neurology 2021年第3期6卷 328-336页

作者： Bryce Owen Omar Akbik Michel Torbey Herbert davis Andrew P Carlson School of Medicine University of New Mexico School of MedicineAlbuquerqueNew MexicoUSA Neurosurgery University of New MexicoAlbuquerqueNew MexicoUSA Neurology University of New MexicoAlbuquerqueNew MexicoUSA Division of Epidemiology Biostatisticsand Preventive MedicineUniversity of New MexicoAlbuquerqueNew MexicoUSA

Introduction Intracerebral haemorrhage(ICH)within deep structures adjacent to the third ventricle is associated with worse outcomes when compared with lobar ICH due to the critical role of deep nuclei in normal neurological *** evidence suggests another contributing factor to poor outcome is obstruction of cerebrospinal fluid outflow by clot burden causing mechanical compression of the third *** authors reviewed the incidence and outcomes of mechanical compression ICH in order to identify this high-risk group which may potentially benefit from minimally invasive *** Patients with spontaneous,non-traumatic,supratentorial ICH were identified retrospectively over a 30-month *** imaging was reviewed to assess location of the ICH,volume of the ICH,presence of hydrocephalus requiring external ventricular drain(EVD)placement,and time to clearing of the third *** was then categorised as due to‘primarily intraventricular haemorrhage(IVH)’,‘primarily mechanical compression’or‘mixed’.Functional outcomes at discharge were assessed using the modified rankin Score(mrS).results 287 patients met inclusion criteria,of which 39(13.5%)patients developed hydrocephalus that required *** patients had significantly higher mrS at discharge(p≤0.001)when compared with the non-EVD *** location was associated with lower odds of poor outcome compared with thalamic location(Or 0.107-0.560).Mechanical compression hydrocephalus was associated with poor outcome when compared with the primary IVH hydrocephalus subgroup(p=0.037)as well as longer time to clearing of the third ventricle(p=0.006).Conclusions Mechanical obstruction requiring EVD occurs in approximately(21/287)7.3%of all patients with spontaneous supratentorial *** is unknown if the worse morbidity in these subjects is purely related to damage to deep structures surrounding the third ventricle or if secondary damage from hydrocephalus could be mitigated with tar

关键词： hydrocephalus damage primarily

Enhanced singlet oxygen generation by hybrid Mn-doped nanocomposites for selective photo-oxidation of benzylic alcohols

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Nano research 2020年第6期13卷 1668-1676页

作者： Zhi-Jun Li Shuya Li Andrew Hunter davis Elan Hofman Gyu Leem Weiwei Zheng Department of Chemistry Syracuse UniversitySyracuseNY13244USA Department of Chemistry State University of New York College of Environmental Science and ForestrySyracuseNY13210USA The Michael M.Szwarc Polymer research Institute SyracuseNY13210USA

Transition-metal ions doped nanocrystals(NCs),specifically Mn-doped NCs,hold great potential in the field of photocatalysis,especially,to improve photocatalytic performance for singlet oxygen(1O2)***,we report the design of a novel Mn-doped NC-based nanocomposites,specifically,silica-coated Mn-doped CdS/ZnS NCs decorated with Pt NCs(denoted as Mn-NCs@SiO2-Pt),which enhance photocatalytic 1O2 *** to the long-lived Mn excited state(on the order of ms),the energy-transfer between Mn-NCs and molecular oxygen is facilitated with the assistance of the Pt NCs adhered to the Mn-NC@SiO2 ***,the Mn-NCs@SiO2-Pt composites,integrate the advantages of Mn-doped NCs,a protective silica layer,and Pt NCs to exhibit excellent catalytic activity and selectivity for the selective oxidation of primary benzylic alcohols to aldehydes through an 1O2 engaged oxidation process under visible-light *** work paves the way for enhancing catalytic performance via facilitated energy transfer relaxation by utilizing the long-lived excited-state of Mn2+dopant ions in nanocomposites.

关键词： doped nanocrystals energy transfer photocatalysis singlet oxygen selective oxidation

Electrical stimulation and denervated muscles after spinal cord injury

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Neural regeneration research 2020年第8期15卷 1397-1407页

作者： Subhalakshmi Chandrasekaran John davis Ines Bersch Gary Goldberg Ashraf S.Gorgey Spinal Cord Injury and Disorders Hunter Holmes McGuire VA Medical CenterRichmondVAUSA Swiss Paraplegic Centre NottwilSwitzerland Institute of Clinical Sciences Department of Orthopedics at the University of GothenburgGothenburgSweden Department of Physical Medicine and rehabilitation Virginia Commonwealth UniversityRichmondVAUSA Electrodiagnostic Center Hunter Holmes McGuire VA Medical CenterRichmondVAUSA

Spinal cord injury(SCI)population with injury below T10 or injury to the cauda equina region is characterized by denervated muscles,extensive muscle atrophy,infiltration of intramuscular fat and formation of fibrous *** morphological changes may put individuals with SCI at higher risk for developing other diseases such as various cardiovascular diseases,diabetes,obesity and ***,there is no available rehabilitation intervention to rescue the muscles or restore muscle size in SCI individuals with lower motor neuron ***,hereby,performed a review of the available evidence that supports the use of electrical stimulation in restoration of denervated muscle following *** pulse width stimulation(LPWS)technique is an upcoming method of stimulating denervated *** primary objective is to explore the best stimulation paradigms(stimulation parameters,stimulation technique and stimulation wave)to achieve restoration of the denervated *** parameters,such as the pulse duration,need to be 100–1000 times longer than in innervated muscles to achieve desirable excitability and *** use of electrical stimulation in animal and human models induces muscle *** in animal models indicate that electrical stimulation,with a combination of exercise and pharmacological interventions,have proven to be effective in improving various aspects like relative muscle weight,muscle cross sectional area,number of myelinated regenerated fibers,and restoring some level of muscle *** studies have shown similar outcomes,identifying the use of LPWS as an effective strategy in increasing muscle cross sectional area,the size of muscle fibers,and improving muscle ***,displaying promise is an effective future stimulation *** summary,LPWS is a novel stimulation technique for denervated muscles in humans with *** studies on LPWS of denervated muscles will help in translating

关键词： denervation DXA electrical stimulation LMN injury LPWS MrI spinal cord injury stimulation parameters

Targeting of elevated cell surface phosphatidylserine with saposin C-dioleoylphosphatidylserine nanodrug as individual or combination therapy for pancreatic cancer

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World Journal of Gastrointestinal Oncology 2021年第6期13卷 550-559页

作者： Harold W davis Ahmet Kaynak Subrahmanya D Vallabhapurapu Xiaoyang Qi Division of Hematology/Oncology Department of Internal MedicineUniversity of Cincinnati College of MedicineBrain Tumor Center at UC Neuroscience InstituteCincinnatiOH 45267United States Department of Biomedical Engineering College of Engineering and Applied ScienceUniversity of CincinnatiCincinnatiOH 45221United States

Pancreatic cancer is one of the deadliest of cancers with a five-year survival of roughly 8%.Current therapies are:surgery,radiation and *** is curative only if the cancer is caught very early,which is rare,and the latter two modalities are only marginally effective and have significant side *** have developed a nanosome comprised of the lysosomal protein,saposin C(SapC)and the acidic phospholipid,dioleoylphosphatidylserine(DOPS).In the acidic tumor microenvironment,this molecule,SapC-DOPS,targets the phosphatidylserine cancer-biomarker which is predominantly elevated on the surface of cancer ***,SapC-DOPS can selectively target pancreatic tumors and ***,SapC-DOPS has exhibited an impressive safety profile with only a few minor side effects in both preclinical experiments and in phase I clinical *** the dismal outcomes for pancreatic cancer there is an urgent need for better treatments and SapC-DOPS is a good candidate for addition to the oncologist’s toolbox.

关键词： Pancreatic cancer Saposin C Dioleoylphosphatidylserine Phosphatidylserine-targeted therapy Chemotherapy radiation

Differential regulation of protein synthesis in skeletal muscle and liver of neonatal pigs by leucine through an mTOrC1-dependent pathway

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Journal of Animal Science and Biotechnology 2012年第1期3卷 32-41页

作者： Agus Suryawan Hanh V Nguyen rosemarie D Almonaci Teresa A davis Department of Pediatrics Baylor College of Medicine United States Department of Agriculture/Agriculture Research Service Children's Nutrition Research Center 1100 Bates Street Houston TX 77030 USA

Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine＇s action in vivo is not well understood. In this study, we investigated the effect of leucine infusion on protein synthesis in skeletal muscle and liver of neonatal pigs. To evaluate the mode of action of leucine, we used rapamycin, an inhibitor of mammalian target of rapamycin （mTOr） complex-1 （mTOrC1）. Overnight-fasted 7-day-old piglets were treated with rapamycin for 1 hour and then infused with leucine （400 μmol·kg^-1·h^-1） for 1 hour. Leucine infusion increased the rate of protein synthesis, and ribosomal protein S6 kinase 1 （S6K1） and eukaryotic initiation factor （elF） 4E-binding protein-1 （4E-BP1） phosphorylation in gastrocnemius and masseter muscles （P 〈 0.05）, but not in the liver. The leucine-induced stimulation of protein synthesis and S6K1 and 4E-BP1 phosphorylation were completely blocked by rapamycin, suggesting that leucine action is by an mTOrC1-dependent mechanism. Neither leucine nor rapamycin had any effect on the activation of the upstream mTQrC1 regulators, AMP-activated protein kinase and protein kinase B, in skeletal muscle or liver. The activation of elF2α and elongation factor 2 was not affected by leucine or rapamycin, indicating that these two pathways are not limiting steps of leucine-induced protein synthesis. These results suggest that leucine stimulates muscle protein synthesis in neonatal pigs by inducing the activation of mTOrC1 and its downstream pathway leading to mrNA translation.

关键词： leucine mTOrC1 neonatal pigs rapamycin skeletal muscle

Host plant selection of Chrysolina clathrata （Coleoptera： Chrysomelidae） from Mpumalanga, South Africa

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Insect Science 2009年第1期16卷 81-88页

作者： robert S. Boyd Micheal A. davis Michael A. Wall Kevin Balkwill Department of Biological Sciences Auburn University Auburn Alabama Department of Biological Sciences University of Southern Mississippi Hattiesburg Mississippi Entomology Department San Diego Natural History Museum San Diego California USA C.E. Moss Herbarium School of Animal and Plant Sciences University of the Witwatersrand Private Bag 3 WITS 2050 Johannesburg South Africa

Hyperaccumulated elements such as Ni may defend plants against some natural enemies whereas other enemies may circumvent this defense. The Ni hyperaccumulator Berkheya coddii roessler （Asteraceae） is a host plant species for Chrysolina clathrata （Clark）, which suffers no apparent harm by consuming its leaf tissue. Beetle specimens collected from B. coddii had a whole body Ni concentration of 260μg/g dry weight, despite consuming leaf material containing 15 100μg Ni/g. Two experiments were conducted with adults of this beetle species： a no-choice experiment and a choice experiment. In the nochoice experiment we offered beetles foliage of one of four speeies ofBerkheya： B. coddii, B. rehmannii Thell. var. rogersiana Thell., B. echinacea （Harv.） O. Hoffm. ex Burtt Davey, and B. insignis （Harv.） Thell. The two former species are Ni hyperaccumulators （defined as having leafNi concentration 〉 1 000 μg/g） whereas the latter have low Ni levels （〈 200 μg/g） in their leaves. Masses of beetles were monitored for 6 days. Choice experiments used growing stem tips from the same Berkheya species, placed into Petri dishes with five Chrysolina beetles in each, and the amount of feeding damage caused on each of the four species was recorded. Beetles in the no-choice experiment gained mass when offered B. coddii, maintained mass on leaves of the other Ni hyperaccumulator （B. rehmannii var. rogersiana）, and lost mass when offered non-hyperaccumulator leaves. In the choice test, beetles strongly preferred B. coddii to other Berkheya species. We conclude that C. clathrata may be host-specific on B. coddii.

关键词： Berkheya coddii bioaccumulation heavy metals host plant specialist nickel

The Dayingzi detachment fault system in Liaodong Peninsula and its regional tectonic significance

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Science China Earth Sciences 2011年第10期54卷 1469-1483页

作者： SHEN Liang LIU JunLai HU Ling JI Mo GUAN HuiMei Gregory A davis State Key Laboratory of Geological Processes and Mineral resources China University ofGeosciences Beijing 100083 China China National Offshore Oil Corporation research Institute Beijing 100027 China Institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China Department of Earth Sciences University of Southern California Los Angeles CA90089-0740 USA

Large scale lithosphere thinning is an important characteristic of the destruction of the North China Craton （NCC） during the late Mesozoic. A series of extensional structures were developed under extensional setting, among which is the Dayingzi detachment fault system （DFS）. The DFS is constituted by three parts, volcano-sedimentary basins at the hanging wall, the Dayingzi-Huanghuadian detachment fault zone, and Paleoproterozoic metamorphic rock series and Mesozoic plutons at the footwall. In the section across the detachment fault zone, there is a sequence of tectonites including fault gouge, microbreccia, cataclastic-mylonites, mylonites, and gneissic biotite monzonite granite. Microstructural characteristics of tectonites and electron backscatter diffraction （EBSD） patterns of quartz indicate that the rocks from the footwall experienced a process from upper greenschist facies to lower greenschist facies. SHrIMP and LA-ICP MS U-Pb dating of zircons from the volcanic rocks in the basins, the tectonic evolution of the DFS is summarized as follows： 1） regional extension started at 135.0±1.2 Ma ago, when the detachment fault cut through the middle crust. Faulting induced the upwelling of magma and eruption of volcanic rocks and deformed a series of medium-acid volcanic rocks; 2） after 135.0±1.2 Ma, a large scale detachment faulting was active cross-cutting the mid-upper crust. The western margin of Jurassic and Triassic granite was ductilly and brittly sheared; besides, the Cretaceous volcanoedimentary rocks were tilted when the master fault approached the surface; 3） at around 127±1 Ma, the detachment fault stopped its activity and was intruded by the unsheared Cretaceous granite near Chaoyang. Comparison with the Liaonan metamorphic core complex （MCC） and other extensional structures in Liaodong Peninsula led to a general trend of including three zones in the Peninsula： MCC zone, detachment fault systems （DFS） zone, and half graben zone. MCC commonly cuts through t

关键词： Liaodong Peninsula detachment fault system Cretaceous extension lithosphere thinning North China Craton