检索结果-南通市图书馆

Molecular Plant 2016年第3期9卷 428-436页

作者： J. Bohm S. Scherzer S. Shabala e. Krol e. Neher T.D. mueller R. Hedrich Julius-yon-Sachs Institute Department for Molecular Plant Physiology and Biophysics University of Wurzburg Julius-von-Sachs Platz 2 97082 Wurzburg Germany School of Land and Food University of Tasmania Hobart TAS 7001 Australia Zoology Department College of Science King Saud University PO Box 2455 Riyadh 11451 Saudi Arabia Department for Membrane Biophysics Max Planck Institute for Biophysical Chemistry 37077 Goettingen Germany

The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na^＋- and K^＋-permeable mutants function as ion channels rather than K^＋ transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na^＋-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.

关键词： sodium channel HKT1 Dionaea muscipula action potential glands sodium uptake

Capsule endoscopy in suspected small bowel Crohn's disease:economic impact of disease diagnosis and treatment

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45期15卷 5685-5692页

作者： jonathan A Leighton Ian M Gralnek Randel e Richner Michael J Lacey Frank J Papatheofanis Division of Gastroenterology and Hepatology Mayo Clinic ScottsdaleAZ 85259United States Rappaport Faculty of Medicine Technion-Israel Institute of Technology GI Outcomes Unit Departments of Gastroenterology and Ambulatory Care Services Rambam Health Care Campus The Neocure Group SherbornMA 01770 United States Division of Health Policy Departments of Radiology and Economics University of California San DiegoSan Diego CA 92103United States

AIM: To model clinical and economic benef its of capsule endoscopy (Ce) compared to ileo-colonoscopy and small bowel follow-through (SBFT) for evaluation of suspected Crohn’s disease (CD). MeTHODS: Using decision analytic modeling, total and yearly costs of diagnostic work-up for suspected CD were calculated, including procedure-related adverse events, hospitalizations, off ice visits, and medications. The model compared Ce to SBFT following ileo-colonoscopy and secondarily compared Ce to SBFT for initial evaluation. ReSULTS: Aggregate charges for newly diagnosed, medically managed patients are approximately $8295. Patients requiring aggressive medical management costs are $29 508; requiring hospitalization, $49 074. At sensitivity > 98.7% and specifi city of > 86.4%, Ce is less costly than SBFT. CONCLUSION: Costs of Ce for diagnostic evaluationof suspected CD is comparable to SBFT and may be used immediately following ileo-colonoscopy.

关键词：经济利益住院治疗诊断小肠内镜胶囊疾病管理费用

Investigating the impact of preoperative corneal astigmatism orientation on the postoperative spherical equivalent refraction following intraocular lens implantation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

eye and Vision 2018年第1期5卷 70-77页

作者： Richard N.McNeely Salissou Moutari eric Pazo jonathan e.Moore Cathedral eye Clinic 89-91 Academy StreetBelfastCounty Antrim BT12 LSNorthern IrelandUK Biomedical Sciences Research Institute University of UlsterColeraineNorthern IrelandUK School of Mathematics and Physics Queens University BelfastBelfastNorthern IrelandUK

Background:To investigate the impact of the orientation of preoperative corneal astigmatism on achieving the postoperative target refraction following monofocal intraocular lens(IOL)***:This study enrolled 339 eyes who had uneventful cataract surgery or refractive lens exchange(RLe)with subsequent monofocal IOL *** were initially categorized dependent upon axial length and then on the orientation of preoperative anterior corneal *** 1 had against-the-rule(ATR)anterior corneal astigmatism,group 2 had with-the-rule(WTR)anterior corneal astigmatism,and group 3 had oblique(OB)anterior corneal *** preoperative corneal astigmatism was determined by the IOLMaster(Carl Zeiss Meditec AG).Postoperative refraction was completed for all eyes,and the results were calculated and compared for the separate ***:In eyes with axial lengths greater than 22.0 mm and less than 25.0 mm there was a significant difference between the magnitude of preoperative corneal astigmatism between groups 2 and 3 with 0.827±0.376 D in group 2,and 0.677±0.387 D in group *** mean postoperative spherical equivalent(Se)prediction error was−0.132±0.475 D in group 1,0.026±0.497 D in group 2,and−0.130±0.477 D in group *** was a significant difference between groups 1 and *** was no significant difference in the magnitude of preoperative corneal astigmatism and postoperative Se prediction error between the anterior corneal astigmatism orientation groups in eyes with axial lengths of less than or equal to 22.0 mm and greater than or equal to 25.0 ***:The orientation of preoperative anterior corneal astigmatism significantly affected the postoperative biometry prediction error in eyes with astigmatism of 1.75 D or less in eyes with the axial length between 22.0 mm and 25.0 ***,the results were not clinically significant.

关键词： Biometry accuracy Prediction error Corneal astigmatism With-the-rule astigmatism Against-the-rule astigmatism Oblique astigmatism

矿石储量估算的地质统计学方法与一些传统方法的比较

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

矿业工程 1979年第1期 1-7+17页

作者： H.P.Knudsen Y.C.Kim e.mueller 宋彦琦

本文叙述了地质统计学的矿石储量估算方法与其他三种传统方法——多边形法、距离倒数平方法(IDS)以及同距离倒数平方法相类似的一种修正法(eLIP)的对比研究结果。用上述各种方法对亚利桑那州图克逊市附近的碧玛铜矿在同一个阶段中的各... 详细信息

本文叙述了地质统计学的矿石储量估算方法与其他三种传统方法——多边形法、距离倒数平方法(IDS)以及同距离倒数平方法相类似的一种修正法(eLIP)的对比研究结果。用上述各种方法对亚利桑那州图克逊市附近的碧玛铜矿在同一个阶段中的各块段的品位子测结果,检验了每种方法的精确度。从碧玛铜矿的对比结果表明:在予测块段品位和矿石总吨量方面,地质统计学方法与eLIP法或IDS法相比较不差土下,而多边形法则显然最差。但如果在块段模型中已经考虑并包含了矿体的地质因素,则上述所有方法都能获得较好的结果,对于已经在生产的矿山来说,选用eLIP法或IDS法可能是比较好的,因为这两种方法占用电子计算机的时间较少,可以显著地节省运算费用。对于一个勘探的矿区或新矿区来说,由于地质统计学方法能够给出估算值的置信限,因而选用这种方法就具有更多的优越。

关键词：平均差平均绝对变率矿石储量地质统计学品位修正法权数

The central role of stem cells in determining plant longevity variation

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Plant Communications 2023年第5期4卷 97-111页

作者： Omid Karami Bernd mueller-Roeber Arezoo Rahimi Plant Developmental Genetics Institute of Biology LeidenLeiden UniversitySylviusweg 722333 BE Leidenthe Netherlands University of Potsdam Institute of Biochemistry and BiologyKarl-Liebknecht-Straße 24–25Haus 2014476 PotsdamGermany Present address:Huygens-Kamerlingh Onnes Laboratory Leiden UniversityNiels Bohrweg 22333 CA Leidenthe Netherlands

Vascular plants display a huge variety of longevity patterns,from a few weeks for several annual species up to thousands of years for some perennial *** how longevity variation is structured has long been considered a fundamental aspect of the life sciences in view of evolution,species distribution,and adaptation to diverse *** animals,whose organs are typically formed during embryogenesis,vascular plants manage to extend their life by continuously producing new tissues and organs in apical and lateral directions via proliferation of stem cells located within specialized tissues called *** cells are the main source of plant *** in plant longevity is highly dependent on the activity and fate identity of stem *** developmental factors determine how stem cells contribute to variation in plant *** this review,we provide an overview of the genetic mechanisms,hormonal signaling,and environmental factors involved in controlling plant longevity through long-term maintenance of stem cell fate identity.

关键词： stem cells plant longevity annual plants perennial plants axillary meristems

equilibrium Segregation to Free Surface:Kinet ics and experiment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1999年第5期16卷 364-366页

作者：曹则贤 Ralf mueller 王恩哥聂玉昕 State Key Laboratory for Surface Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080 Department of Physics University Kaiserslautern67653 KaiserslauternGermany

Fick's first law is modified with an additional term df(x)/dx to describe the segregation phenomenon,f(x)is a local,analytical function related to the depth profile at *** thus can be determined experimentally by depth profiling *** starting in an initially homogeneous solid is described by an inhomogeneous diffusion equation on the half-infinite *** with and without formation of overlayer suggests different boundary *** solution for the Ansatz f(x)=as exp(-x/d_(s))is in perfect agreement with experimental results on sulphur segregation to the surface of *** from the detailed kinetics,activation energy can be inferred from the surface concentration evolution under different *** sulphur segregation in titanium,e_(act)=718 meV/atom.

关键词： technique. titanium sulphur

Alcoholic liver disease and hepatitis C:A frequently underestimated combination

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28期15卷 3462-3471页

作者： Sebastian mueller Gunda Millonig Helmut K Seitz Department of Medicine and Center for Alcohol Research Live Disease and Nutrition Salem Medical Center University of Heidelberg Zeppelinstraβe 11-33 69121 Heidelberg Germany

Alcoholic liver disease(ALD) and hepatitis C virus(HCV) infection represent, either alone or in combination, more than two thirds of all patients with liver disease in the Western *** review discusses the epidemiology and combined impact of ALD and HCV on the progres sion of liver *** and HCV affect the progres sion of liver disease to liver cirrhosis and hepatocellular carcinoma(HCC) in a synergistic ***, the risk for HCC increases f ive times with a daily alcohol con sumption of 80 g;in the presence of HCV it is increased 20fold, and a combination of both risk factors leads to a more than 100fold risk for HCC *** consumption also decreases the response to interferon treatment which is probably due to a lack of compliance than a direct effect on HCV *** molecu lar mechanisms are discussed that could explain the synergistic interaction of alcohol and HCV on disease *** include modulation of the immune response and apoptosis, increased oxidative stress via induction of CYP2e1 and the hepatic accumulation of ***, both HCV and alcohol independently cause hepatic iron accumulation in > 50% of patients probably due to suppression of the liversecreted systemic iron hormone hepcidin.A better understanding of hepcidin regulation could help in developing novel therapeutic approaches to treat the chronic disease in the *** now, it can be generally concluded that HCVinfect ed patients should abstain from alcohol and alcoholicsshould be encouraged to participate in detoxification programs.

关键词：丙型肝炎酒精性肝病

Toward the implementation of a universal angle-based optical indoor positioning system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2018年第2期11卷 116-127页

作者： Mark H. BeRGeN Ferdinand S. SCHAAL Richard KLUKAS Julian CHeNG jonathan e HOLZMAN Faculty of Applied Science University of British Columbia Kelowna BC V1V 1V7 Canada Technical University of Denmark Anker Engelunds Vej 1 Bygning 101A 2800 Kgs. Lyngby Denmark

There is an emerging market today for indoor positioning systems capable of working alongside global navigation satellite systems, such as the global positioning system, in indoor environments. Many systems have been proposed in the literature but all of them have fundamental flaws that hold them back from widescale implementation. We review angle-of-arrival （AOA） and angle-difference- of-arrival （ADOA） optical indoor positioning systems which have been proven to be robust, accurate, and easily implementable. We build an AOA/ADOA optical indoor positioning system out of a simple commercial high-speed camera and white light light emitting diodes （LeDs） which operate over a working area of 1 m3, and compare its performance to other indoor positioning methods. The AOA and ADOA systems achieve positioning with low errors of 1.2 and 3.7 cm, respectively.

关键词： angle-of-arrival (AOA) angle-difference-of-arrival (ADOA) indoor positioning optical positioning

Cytoplasmic dynein-2： from molecules to human diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Biology 2013年第1期8卷 119-126页

作者： Vidyalakshmi RAJAGOPALAN jonathan P. D'AMICO David e. WILKeS Department of Biological Sciences Indiana University South Bend South Bend IN 46634-7111 USA

The dynein motor protein family is involved in a wide variety of functions in eukaryotic cells. The axonemal dynein class and cytoplasmic dynein-1 subclass have been well characterized. However, the cytoplasmic dynein-2 subclass of the family has only recently begun to be understood. We describe the entire dynein family but focus on cytoplasmic dynein-2. Dynein-2 consists of a heavy, an intermediate, a light intermediate, and a light chain. The complex appears to function primarily as the retrograde motor for intraflagellar transport. This process is important for the formation and maintenance of cilia and flagella. Additionally, dynein-2 has roles in the control of ciliary length and in non-ciliary functions. Mutations in the human dynein-2 heavy chain lead to cilia-related diseases.

关键词： cilia dynein flagella intraflagellar transport microtubule

All-optical sampling of few-cycle infrared pulsesusing tunneling in a solid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2021年第6期9卷 929-936页

作者： YANGYANG LIU SHIMA GHOLAM-MIRZAeI JOHN e.BeeTAR jonathan NeSPeR AHMeD YOUSIF M.NRISIMHAMURTY MICHAeL CHINI Department of Physics University of Central FloridaOrlandoFlorida 32816USA CReOL The College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA

Recent developments in ultrafast laser technology have resulted in novel few-cycle sources in the *** characterizing the time-dependent intensities and electric field waveforms of such laser pulses is essential to their applications in strong-field physics and attosecond pulse generation,but this remains a ***,it was shown that tunnel ionization can provide an ultrafast temporal“gate”for characterizing highenergy few-cycle laser waveforms capable of ionizing ***,we show that tunneling and multiphoton excitation in a dielectric solid can provide a means to measure lower-energy and longer-wavelength pulses,and we apply the technique to characterize microjoule-level near-and mid-infrared *** method lends itself to both all-optical and on-chip detection of laser waveforms,as well as single-shot detection geometries.

关键词： optical tunneling cycle