检索结果-南通市图书馆

The Psb.2 Protein Aids in Repairing Photodamaged Photosystem II in the Cyanob.cterium Synechocystis 6803

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2011年第6期4卷 1052-1061页

作者： kimberly M. Wegener Stefan b.nnewitz Ralf Oelmuller Himadri b. Pakrasi Department of b.ology Washington University St Louis MO 63130 USA Present address： Division of b.ological Sciences University of Missouri Columbia MO 65211 USA Institute of Plant Physiology Friedrich-Schiller-University Jena Dornburger Str. 159 D-07743 Jena Germany

Photosystem II （PSII）, a memb.ane protein complex, catalyzes the photochemical oxidation of water to molecular oxygen. This enzyme complex consists of approximately 20 stoichiometric protein components. However, due to the highly energetic reactions it catalyzes as part of its normal activity, PSII is continuously damaged and repaired. With advances in protein detection technologies, an increasing numb.r of sub.stoichiometric PSII proteins have b.en identified, many of which aid in the b.ogenesis and assemb.y of this protein complex. Psb.2 （SII1390） has previously b.en identified as a protein associated with highly active purified PSII preparations from the cyanob.cterium Synechocystis sp. PCC 6803. To investigate its function, the sub.ellular localization of Psb.2 and the impact of deletion of the psb.2 gene on PSII were analyzed. Here, we show that Psb.2 is an integral memb.ane protein, primarily located in the thylakoid memb.anes. Al- though not required for cell viab.lity, Psb.2 protects cells from oxidative stress and additionally confers a selective fitness advantage in mixed culture experiments. Specifically, Psb.2 protects PSII from photodamage and accelerates its repair. Thus, the data suggest that Psb.2 plays an important role in minimizing the effect of photoinhib.tion on PSII.

关键词： Photosynthesis reactive oxygen species photoinhib.tion photodamage.

A matter of time： Temporal variation in the introduction history and population genetic structuring of an invasive lizard

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2015年第3期61卷 456-464页

作者： HalmahMOULE Kirilee CHAPLIN Reb.cca D. b.AY kimberly A. MILLER Michael b. THOMSON David G. CHAPPLE School of b.ological Sciences Monash University Clayton Victoria 3800 Australia Department of Sciences Museum Victoria Victoria 3001 Australia School of b.ological Sciences University of Sydney Sydney NSW 2006 Australia Allan Wilson Centre for Molecular Ecology and Evolution School of Biological Sciences Victoria University of Wellington Wellington 6140 New Zealand

Invasive species are considered one of the greatest threats to native ecosystems, second only to hab.tat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the b.ology and genetics of the invader. We investigated the invasion of Lord Howe Island b. the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had b.en introduced to the island, and shifts in haplotype frequencies） of the species on the island b.tween these two time points. No new haplotypes were introduced to the island b.tween 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enab.e us to b.tter manage their impacts

关键词： b.ological invasion Genetic admixture Lampropholis delicata Lord Howe Island Population genetics,Unintentional introduction

The p75 neurotrophin receptor:at the crossroad of neural repair and death

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2015年第5期10卷 721-725页

作者： Rick b.Meeker kimberly S.Williams Department of Neurology University of North Carolina Curriculum in Neurob.ology University of North Carolina

The strong repair and pro-survival functions of neurotrophins at their primary receptors, TrkA, Trkb.and TrkC, have made them attractive candidates for treatment of nervous system injury and disease. However, difficulties with the clinical implementation of neurotrophin therapies have prompted the search for treatments that are stab.e, easier to deliver and allow more precise regula- tion of neurotrophin actions. Recently, the p75 neurotrophin receptor （p75wrR） has emerged as a potential target for pharmacological control of neurotrophin activity, supported in part b. stud- ies demonstrating 1） regulation of neural plasticity in the mature nervous system, 2） promotion of adult neurogenesis and 3） increased expression in neurons, macrophages, microglia, astro- cytes and/or Schwann cells in response to injury and neurodegenerative diseases. Although the receptor has no intrinsic catalytic activity it interacts with and modulates the function of TrkA, Trkb. and TrkC, as well as sortilin and the Nogo receptor. This provides sub.tantial cellular and molecular diversity for regulation of neuron survival, neurogenesis, immune responses and pro- cesses that support neural function. Upregulation of the p75^NTR under pathological conditions places the receptor in a key position to control numerous processes necessary for nervous system recovery. Support for this possib.lity has come from recent studies showing that small, non-pep- tide p75^NTR ligands can selectively modify pro-survival and repair functions. While a great deal remains to b. discovered ab.ut the wide ranging functions of the p75^NTR, studies summarized in this review highlight the immense potential for development of novel neuroprotective and neu- rorestorative therapies.

关键词： injury plasticity neurodegenerative disease b.ain therapy neuron microglia neuralprogenitor

Semiconductor nanostructures enab.ed b. aerosol technology

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2014年第3期9卷 398-418页

作者： Martin H. Magnusson b. Jonas Ohlsson Mikael T. b.ork kimberly A. Dick Magnus T. b.rgstrom Knut Deppert Lars Samuelson Solid State Physics Lund University Box 118 SE-22100 Lund Sweden Sol Voltaics Ab Ideon Science Park Scheelevagen 17 SE-22370 Lund Sweden QuNano Ab Ideon Science Park Scheelevaigen 17 SE-22370 Lund Sweden Center for Analysis and Synthesis Lund University Box 124 SE-22100 Lund Sweden

Aerosol technology provides efficient methods for producing nanoparticles with well-controlled composition and size distrib.tion. This review provides an overview of methods and results ob.ained b. using aerosol technology for producing nanostruetures for a variety of applications in semiconductor physics and device technology. Examples are given from： production of metal and metal alloy particles： semiconductor nanoparticles; semiconductor nanowires, grown b.th in the aerosol phase and on sub.trates; physics studies b.sed on individual aerosol-generated devices; and large area deviees b.sed on aerosol particles.

关键词： aerosol nanoparticle nanowire metal-organic vapor phase epitaxy (MOVPE) device physics light emitting diodes (LED) solar cell

Acquired segmental colonic hypoganglionosis in an adult Caucasian male:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2019年第2期11卷 101-111页

作者： Allan MF Kwok Andrew b.Still kimberly Hart Department of Surgery Wollongong Hospital Department of Anatomical Pathology Wollongong Hospital

b.CKGROUND Hypoganglionosis is a rare condition that most often presents with ab.ormal gastrointestinal transit and usually arises in early childhood or adolescence. Two types have b.en describ.d(Type I and Type II). The adult-onset form(acquired hypoganglionosis) is extremely uncommon and is thought to arise due to cellular remodelling as a result of chronic inflammation. It differs from Hirschprung's disease in that there is a reduction in ganglion cells in the colonic neural plexuses as opposed to b.ing completely *** SUMMARY A 31 year-old male presented to hospital with recurrent ab.ominal pain and vomiting over thirteen months. Ab.ominal computed tomography scans demonstrated thickening and stranding affecting the transverse, descending and sigmoid colon. Endoscopic appearances were non-specific b.t confirmed a mixed picture of mucosal inflammation and necrosis in various stages of *** investigations were performed to elucidate an underlying aetiology b.t neither an infective nor ischaemic cause could b. proven. b.opsy features were not typical of inflammatory b.wel disease. Due to persistence of his symptoms and failure of medical management, a segmental colectomy was performed. Histological examination of the specimen revealed an unexpected finding of segmental hypoganglionosis. Complete surgical excision of the diseased segment of colon was curative and since his operation the patient has had no recurrence of symptoms requiring *** Our case serves to raise awareness of acquired hypoganglionosis as a rare condition that can result from chronic colitis.

关键词： Acquired hypoganglionosis Hirschprung’s disease Adult Ganglion cells Acetylcholinesterase Calretinin Case report

Outcomes of severe sepsis and septic shock patients after stratifi cation b. initial lactate value

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2018年第2期9卷 113-117页

作者： kimberly A. Chamb.rs Adam Y. Park Rosa C. b.nuelos b.yan F. Darge b.ndu H. Akkanti Annamaria Macaluso Manoj Thangam Pratik b. Doshi Department of Emergency Medicine McGovern Medical School at UTHealth Houston TX USA McGovern Medical School at UTHealth Houston TX USA Division of Critical Care Department of Internal Medicine McGovern Medical School at UTHealth Houston TX USA Department of Emergency Medicine University of California San Francisco CA USA Memorial Hermann Hospital - Texas Medical Center Houston TX USA Department of Internal Medicine McGovern Medical School at UTHealth Houston TX USA

b.CKGROUND: In the setting of severe sepsis and septic shock, mortality increases when lactate levels are ≥ 4 mmol/L. However, the consequences of lower lactate levels in this population are not well understood. The study aimed to determine the in-hospital mortality associated with severe sepsis and septic shock when initial lactate levels are b.sed on initial lactate values. Group 1 had lactate levels b. statistically significant. Multivariate logistic regression demonstrated higher odds of death with higher lactate tier group, however the findings did not reach statistical ***: This study found that only assignment to group 3, initial lactic acid level of ≥ 4 mmol/L, was independently associated with increased mortality after correcting for underlying severity of illness and organ dysfunction. However, rising lactate levels in the other two groups were associated with increased severity of illness and were inversely proportional to prognosis.

关键词： Sepsis Lactic acid Emergency medicine

Non-viral causes of hepatocellular carcinoma

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第29期16卷 3603-3615页

作者： Wojciech b.onski David S Kotlyar kimberly A Forde Division of Gastroenterology University of Pennsylvania Department of Gastroenterology Medical University Wroclaw Department of Internal Medicine Montefi ore Medical CenterAlbert Einstein College of Medicine

Hepatocellular carcinoma(HCC) is the most common primary liver malignancy and represents an international pub.ic health concern as one of the most deadly cancers *** main etiology of HCC is chronic infection with hepatitis b.and hepatitis C ***,there are other important factors that contrib.te to the international b.rden of *** these are ob.sity,diab.tes,non-alcoholic steatohepatitis and dietary *** evidence suggests that the etiology of many cases of HCC is in fact multifactorial,encompassing infectious etiologies,comorb.d conditions and environmental *** of relevant non-viral causes of HCC will aid in preventative efforts to curb.the rising incidence of this disease.

关键词： Hepatocellular carcinoma Etiology Nonalcoholic steatohepatitis Ob.sity Diab.tes Alcohol Tob.cco Oral contraceptive

Do statins reduce hepatitis C RNA titers during routine clinical use?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第40期15卷 5020-5027页

作者： kimberly A Forde Connie Law Rose O’Flynn David E Kaplan Philadelphia Veterans Administration Medical Center Department of Medicine Division of GastroenterologyUniversity of Pennsylvania Department of Pharmacy Philadelphia Veterans Administration Medical Center

AIM: To compare hepatitis C virus (HCV) titers in patients with chronic hepatitis C with and without exposure to 3-hydroxy-3-methylglutaryl coenzyme A reductase inhib.tors (statins).METHODS: Medical records were reviewed for 6463 patients with documented HCV infection at a single center b.tween March 2004 and Septemb.r 2006. Patients with confi rmed viremia and meeting inclusion criteria were assigned to one of three groups: Group A (n = 50), dyslipidemic patients with statin usage during HCV RNA polymerase chain reaction (PCR) determination; Group b.(n = 49), dyslipidemic patients with prior or future statin usage b.t not at the time of HCV RNA PCR determination; and Group C (n = 102), patients without statin usage during the study period. The primary analysis explored the effect of statin therapy on HCV viremia. Secondary analyses assessed class effect, dose response, and effect of other lipid-lowering therapies on HCV viral ***: Median HCV RNA titers did not signif icantly differ among the three groups (Group A: 4 550 000 IU/mL, Group b. 2 850 000 IU/mL, Group C: 3 055 000 IU/mL).For those sub.ects with longitudinal assessment of HCV viremia prior to and while on statins, there were no signif icant differences b.tween pre- and post-HCV viral titers. Additionally, no differences in HCV titers were ob.erved at any dose level of the most prescrib.d statin, simvastatin. However, hypertriglyceridemia independently correlated with HCV titers, and niacin exposure was associated with signif icantly lower viral titers (P b.e antiviral properties of triglyceride-lowering agents and their potential role as adjuncts to standard HCV therapy.

关键词： Hepatitis C 3-hydroxy-3-methylglutaryl coenzyme A reductase inhib.tor Statins Geranylgeranyl Prenylation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

飞扬草中的三菇成分及其细胞毒活性(英文)

中国天然药物 2013年第5期11卷 528-533页

作者： Consolacion Y.Ragasa kimberly b.Cornelio Chemistry Department and Center for Natural Sciences and Ecological Research De La Salle University

AIM:To investigate the chemical constituents of the stems,leaves and roots of Euphorb.a hirta,and to test for the cytotoxic and antimicrob.al potentials of the major constituents of the ***: The compounds were isolated b. silica gel chromatography and their structures were elucidated b. NMR *** cytotoxicity tests were conducted using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium b.omide(MTT) assay,while the antimicrob.al tests employed the agar well ***: The air-dried stems of *** afforded taraxerone 1,a mixture of 25-hydroperoxycycloart-23-en-3-ol(2a) and 24-hydroperoxycycloart-25-en-3-ol(2b.(sample 2) in a 2:1 ratio,and another mixture of cycloartenol(3a),lupeol(3b.,-amyrin(3c) and-amyrin(3d)(sample 3) in a 0.5:4:1:1 *** air-dried leaves of *** yielded sample 2 in a 3:2 ratio,sample 3 in a 2:3:1:1 ratio,phytol and phytyl fatty acid ester,while the roots afforded sample 2 in a 2:1 ratio,sample 3 in a 2:1:1:1 ratio,a mixture of cycloartenyl fatty acid ester 4a,lupeol fatty acid ester 4b.-amyrin fatty acid ester 4c and-amyrin fatty acid ester 4d(sample 4) in a 3:2:1:1 ratio,linoleic acid,-sitosterol and *** 1 from the stems,sample 2 from the leaves,and sample 3 from the stems were assessed for cytotoxicity against a human cancer cell line,colon carcinoma(HCT 116).Sample 2 showed good activity with an IC50 value of 4.8 g·mL 1,while 1 and sample 3 were inactive against HCT *** 2 was further tested for cytotoxicity against non-small cell lung adenocarcinoma(A549).It showed good activity against this cell line with an IC50 value of 4.5 g·mL *** assays were conducted on 1 and sample *** of the study indicated that 1 was active against the b.cteria: Pseudomonas aeruginosa and Staphylococcus aureus,b.t was inactive against Escherichia coli and b.cillus *** 2 was active against the b.cteria: Pseudomonas aeruginosa,Staphylococcus aureus and Escherichia coli and fungi:

关键词： Euphorb.a hirta Asteraceae 25-Hydroperoxycycloart-23-en-3-ol 24-Hydroperoxycycloart-25-en-3-ol Cytotoxicity