检索结果-南通市图书馆

Observation of a single protein by ultrafast X-ray diffraction

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第1期13卷 80-90页

作者： Tomas Ekeberg Dameli Assalauova johan Bielecki rebecca Boll Benedikt j.Daurer Lutz A.Eichacker Linda E.Franken Davide E.Galli Luca Gelisio Lars Gumprecht Laura H.gunn janos Hajdu robert Hartmann Dirk Hasse Alexandr Ignatenko jayanath Koliyadu Olena Kulyk ruslan Kurta Markus Kuster Wolfgang Lugmayr jannik Lübke Adrian P.Mancuso Tommaso Mazza Carl Nettelblad Yevheniy Ovcharenko Daniel E.rivas Max rose Amit K.Samanta Philipp Schmidt Egor Sobolev Nicusor Timneanu Sergey Usenko Daniel Westphal Tamme Wollweber Lena Worbs Paul Lourdu Xavier Hazem Yousef Kartik Ayyer Henry N.Chapman jonas A.Sellberg Carolin Seuring Ivan A.Vartanyants jochen Küpper Michael Meyer Filipe r.N.C.Maia Laboratory of Molecular Biophysics Department of Cell and Molecular BiologyUppsala UniversityHusargatan 3(Box 596)SE-75124 UppsalaSweden Deutsches Electronen-Synchrotron DESY Notkestrasse 8522607 HamburgGermany European XFEL Holzkoppel 422869 SchenefeldGermany Diamond Light Source Harwell Science&Innovation CampusDidcot OX110DEUK University of Stavanger Centre Organelle ResearchRichard-Johnsensgate 44021 StavangerNorway Leibniz Institute for Experimental Virology(HPI) Centre for Structural Systems BiologyNotkestraße 8522607 HamburgGermany Dipartimento di Fisica“Aldo Pontremoli” Universitàdegli Studi di Milanovia Celoria 1620133 MilanoItaly Center for Free-Electron Laser Science DESY22607 HamburgGermany Plant Biology Section School of Integrative Plant ScienceCornell UniversityIthacaNY 14853USA PNSensor GmbH Otto-Hahn-Ring 6D-81739 MünchenGermany Biomedical and X-ray Physics Department of Applied PhysicsAlbaNova University CenterKTH Royal Institute of TechnologySE-10691 StockholmSweden ELI Beamlines/IoP Institute of Physics AS Cr v.v.i.Na Slovance 218221 Prague 8Czech Republic Multi-User CryoEM Facility Centre for Structural Systems BiologyNotkestr.8522607 HamburgGermany University Medical Center Hamburg-Eppendorf(UKE) Martinistrasse 5220246 HamburgGermany The Hamburg Center for Ultrafast Imaging Universität HamburgLuruper Chaussee 14922761 HamburgGermany Department of Physics Universität HamburgLuruper Chaussee 14922761 HamburgGermany Department of Chemistry and Physics La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVIC 3086Australia Division of Scientific Computing Science for Life LaboratoryDepartment of Information TechnologyUppsala UniversityBox 337SE-75105 UppsalaSweden European Molecular Biology Laboratory c/o DESYNotkestrasse 8522607 HamburgGermany Department of Physics and Astronomy Uppsala UniversityBox 516SE-75120 UppsalaSweden Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 14922761 HamburgGe

The idea of using ultrashort X-ray pulses to obtain images of single proteins frozen in time has fascinated and inspired *** was one of the arguments for building X-ray free-electron *** to theory,the extremely intense pulses provide sufficient signal to dispense with using crystals as an amplifier,and the ultrashort pulse duration permits capturing the diffraction data before the sample inevitably *** was first demonstrated on biological samples a decade ago on the giant *** then,a large collaboration has been pushing the limit of the smallest sample that can be *** ability to capture snapshots on the timescale of atomic vibrations,while keeping the sample at room temperature,may allow probing the entire conformational phase space of *** we show the first observation of an X-ray diffraction pattern from a single protein,that of Escherichia coli GroEL which at 14 nm in diameter is the smallest biological sample ever imaged by X-rays,and demonstrate that the concept of diffraction before destruction extends to single *** the pattern,it is possible to determine the approximate orientation of the *** experiment demonstrates the feasibility of ultrafast imaging of single proteins,opening the way to single-molecule time-resolved studies on the femtosecond timescale.

关键词： smallest intense ultrafast

Complementary Phenotyping of Maize root System Architecture by root Pulling Force and X-ray Imaging

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Phenomics 2021年第1期3卷 298-309页

作者： M.r.Shao N.jiang M.Li A.Howard K.Lehner j.L.Mullen S.L.gunn j.K.McKay C.N.Topp Donald Danforth Plant Science Center Saint LouisMOUSA Department of Agricultural Biology Colorado State UniversityFort CollinsCOUSA

The root system is critical for the survival of nearly all land plants and a key target for improving abiotic stress tolerance,nutrient accumulation,and yield in crop *** many methods of root phenotyping exist,within field studies,one of the most popular methods is the extraction and measurement of the upper portion of the root system,known as the root crown,followed by trait quantification based on manual measurements or 2D ***,2D techniques are inherently limited by the information available from single points of ***,we used X-ray computed tomography to generate highly accurate 3D models of maize root crowns and created computational pipelines capable of measuring 71 features from each *** approach improves estimates of the genetic contribution to root system architecture and is refined enough to detect various changes in global root system architecture over developmental time as well as more subtle changes in root distributions as a result of environmental *** demonstrate that root pulling force,a high-throughput method of root extraction that provides an estimate of root mass,is associated with multiple 3D traits from our *** combined methodology can therefore be used to calibrate and interpret root pulling force measurements across a range of experimental contexts or scaled up as a stand-alone approach in large genetic studies of root system architecture.

关键词： root crown enough

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

松软粘土中浅层隧道周围地面的运动

地下空间与工程学报 1988年第1期 75-80页

作者： r.j.Mair,M.j.gunn,M.P.O’reilly,周成元助理研究员英国运输与道路研究实验室隧道及地下管道科英国Scott wilson Kirkpatrick股份公司主任四川省人防办公室助理总工程师英国剑桥大学工程系

对于松软粘土中建造浅层隧道时所引起的地面活动进行预测是工程师们面临的主要问题之一。已经用有限元和离心模型研究对隧道变形性能作了测定,并且根据十分明确的有效应力条件下得到的结果提出了一个新的预测地面活动的近似方法。

关键词：有限元分析法粘土土壤流失量中浅层离心模型试验周围

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

局灶性癫痫的心律失常:一个前瞻性长期研究

世界核心医学期刊文摘（神经病学分册） 2005年第5期1卷 8-9页

作者： rugg- gunn F.j. Simister r.j. Squirrell M P. j.S. Duncan 王英鹏 Natl. Soc. Epilepsy Dept. Clin. E. Institute of Neurology Univ ersity College London London United Kingdom

Background Patients with epilepsy are at risk of sudden unexpected death. Neu rogenic cardiac arrhythmias have been postulated as a cause. Electrocardiograms (ECG) can be monitored by use of an implantable loop recorder for up to 18 month s. We aimed to determine the frequency of cardiac arrhythmias in patients with r efractory focal seizures over an extended period. Methods 20 patients received a n implantable loop recorder at one hospital in the UK. Devices were programmed t o record automatically if bradycardia ( r min) or tachycardia ( > 1 40 beats per min) were detected. Additionally, in the event of a seizure, patien ts and relatives could initiate ECG recording with an external activator device. Data were analysed at regular intervals and correlated with seizure diaries. Fi ndings More than 220 000 patient hours were monitored over 24 months, during w hich ECGs were captured on implantable loop recorders in 377 seizures. One patie nt withdrew from the study. In 16 patients, median heart rate during habitual se izures exceeded 100 beats per min. Ictal bradycardia ( r min) was r are, occurring in eight (2 1% ) recorded events, in seven patients. Four pati ents (21% ) had bradycardia or periods of asystole with subsequent permanent pa cemaker insertion. Three of these four (16% of total) had potentially fatal as ystole. Interpretation Clinical characteristics of patients with peri ictal ca rdiac abnormalities are closely similar to those at greatest risk of sudden unex pected death in epilepsy. Asystole might underlie many of these deaths, which wo uld have important implications for the investigation of similar patients and af fect present cardiac pacing policies.

关键词：局灶性癫痫起博器心动过速心脏起搏植入式心动过缓中位心心搏神经源性设备启动

在线全文

学校读者我要写书评

暂无评论

肺PET图像的定量分析:挑战和机遇

中华核医学与分子影像杂志 2019年第11期39卷 698-704页

作者：陈聪霞(译) 李文婵(译) 郭悦(译) 姚稚明(审校者) Delphine L.Chen joseph Cheriyan Edwin r.Chilvers Gourab Choudhury Christopher Coello Martin Connell Marie Fisk Ashley M.Groves roger N.gunn Beverley F.Holman Brian F.Hutton Sarah Lee William MacNee Divya Mohan David Parr Deepak Subramanian ruth Tai-Singer Kris Thielemans Edwin j.r.van Beek Laurence Vass jeremy W.Wellen Ian Wilkinson Frederick j.Wilson 北京医院核医学科、国家老年医学中心 100730 Mallinckrodt Institute of radiology Washington University School of MedicineSt.LouisMissouri Department of Medicine University of CambridgeCambridgeUnited Kingdom Cambridge University Hospitals NHS Foundation Trust CambridgeUnited Kingdom Queen's Medical research Institute University of EdinburghEdinburghUnited Kingdom Imanova Ltd. London y United Kingdom Institute of Nuclear Medicine University College LondonLondonUnited Kingdom Department of Medicine Imperial College LondonLondonUnited Kingdom Medical Image Analysis Consultant LondonUnited Kingdom Clinical Discovery Respiratory Therapy Area UnitGlaxoSmithKline R&DKing of PrussiaPennsylvania University Hospitals Coventry and Warwickshire CoventryUnited Kingdom Derby Teaching Hospitals NHS Foundation Trust DerbyUnited Kingdom Worldwide research and Development PfizerInc.CambridgeMassachusetts Experimental Medicine Imaging GlaxoSmithKlineStevenageUnited Kingdom

数百万人受呼吸系统疾病的影响,导致巨大的全球性健康困扰。由于目前对导致呼吸系统疾病发展和进展的潜在机制认识不足,治疗选择仍然有限。为克服此局限和理解相关分子变化,将无创影像技术如PET和SPECT用于探索生物标志物,其中18F-脱氧... 详细信息

数百万人受呼吸系统疾病的影响,导致巨大的全球性健康困扰。由于目前对导致呼吸系统疾病发展和进展的潜在机制认识不足,治疗选择仍然有限。为克服此局限和理解相关分子变化,将无创影像技术如PET和SPECT用于探索生物标志物,其中18F-脱氧葡萄糖(FDG)PET显像的研究最多。由于肺内组织、气体、血液和水的构成比变异,定量分析肺的分子影像数据仍具挑战性。这些成分的比例随着肺部疾病的不同而不同,因此有不同的定量分析方法来显示这种变化,但迄今为止还没有开发出对数据标准化的方法。该文回顾了肺部疾病中18F-FDG PET定量分析方法的数据,聚焦于解释肺内成分变化的方法,解读衍生参数。分析的疾病包括急性呼吸窘迫综合征、慢性阻塞性肺疾病、肺间质性疾病如特发性肺纤维化。基于对既往文献、进行中的研究以及作者间讨论的回顾,作者提出了建议性的注意事项,以协助解读从这些方法及未来研究设计中衍生的参数。

关键词：肺肺部炎症分子成像正电子发射计算机断层显像

在线全文

学校读者我要写书评

暂无评论

局灶性癫痫全脑T2图证实存在潜在的异常

世界核心医学期刊文摘（神经病学分册） 2005年第6期1卷 45-45页

作者： rugg- gunn F.j. Boulby P.A. Symms M.r. j.S. Duncan 姚庆和 National Society for Epilepsy Gerrards Cross Bucks SL9 0RJ United Kingdom Prof.

Objectives: To examine the cerebral structure of 14 patients with partial seizures and acquired lesions, 20 patients with malformations of cortical development (MCDs), and 45 patients with partial seizures and normal conventional MrI using whole- brain T2 mapping and statistical parametric mapping (SPM). Methods: T2 maps were calculated, and individual patients were compared with a group of 30 control subjects using SPM. results: T2 mapping and objective voxel- by- voxel statistical comparison identified regions of increased T2 signal in all 14 patients with acquired nonprogressive cerebral lesions and partial seizures. In all of these, the areas of increased T2 signal concurred with abnormalities identified on visual inspection of conventional MrI. In 18 of 20 patients with MCDs, SPM detected regions of increased T2 signal, all of which corresponded to abnormalities identified on visual inspection of conventional MrI. In addition, in both groups, there were areas that were normal on conventional imaging, which demonstrated abnormal T2 signal. Voxel- by- voxel statistical analysis identified increased T2 signal in 23 of the 45 patients with cryptogenic focal epilepsy. In 20 of these, the areas of increased T2 signal concurred with epileptiform EEG abnormality and clinical seizure semiology. Group analysis of MrI- negative patients with electroclinical seizure onset localizing to the left and right temporal and left and right frontal regions revealed increased T2 signal within the white matter of each respective lobe. Conclusions: T2 mapping analyzed using statistical parametric mapping was sensitive in patients with malformations of cortical development and acquired cerebral damage. Increased T2 signal in individual and grouped MrInegative patients suggests that minor structural abnormalities exist in occult epileptogenic cerebral lesions.

关键词：局灶性癫痫 T2 信号增强临床发作非进展性脑损伤体素右颞叶谱分析法大脑结构

Three-dimensional visualization of planta clathrin-coated vesicles at ultrastructural resolution

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2022年第10期15卷 1533-1542页

作者： Alexander johnson Walter A.Kaufmann Christoph Sommer Tommaso Costanzo Dana A.Dahhan Sebastian Y.Bednarek jiri Friml Institute of Science and Technology Austria(ista) 3400KlosterneuburgAustria UW-Madison Department of Biochemistry433 Babcock Dr.MadisonWI 53706USA

Biological systems are the sum of their dynamic three-dimensional(3D)***,it is critical to study biological structures in 3D and at high resolution to gain insights into their physiological *** microscopy of metal replicas of unroofed cells and isolated organelles has been a key technique to visualize intracellular structures at nanometer ***,many of these methods require specialized equipment and personnel to complete ***,we present novel accessible methods to analyze biological structures in unroofed cells and biochemically isolated organelles in 3D and at nanometer resolution,focusing on Arabidopsis clathrin-coated vesicles(CCVs).While CCVs are essential trafficking organelles,their detailed structural information is lacking due to their poor preservation when observed via classical electron microscopy protocols ***,we establish a method to visualize CCVs in unroofed cells using scanning transmission electron microscopy tomography,providing sufficient resolution to define the clathrin coat ***,the samples are prepared directly on electron microscopy grids,removing the requirement to use extremely corrosive acids,thereby enabling the use of this method in any electron microscopy ***,we demonstrate that this standardized sample preparation allows the direct comparison of isolated CCV samples with those visualized in ***,to facilitate the high-throughput and robust screening of metal replicated samples,we provide a deep learning analysis method to screen the“pseudo 3D”morphologies of CCVs imaged with 2D ***,our work establishes accessible ways to examine the 3D structure of biological samples and provide novel insights into the structure of plant CCVs.

关键词： Arabidopsis thaliana clathrin-coated vesicles STEM tomography electron microscopy clathrin-mediated endocytosis