检索结果-南通市图书馆

Functional Analysis of Semi-conserved Transit Peptide Motifs and Mechanistic Implications in Precursor Targeting and Recognition

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2016年第9期9卷 1286-1301页

作者： Kristen Holbrook Chitra Subramanian Prakitchai Chotewutmontri L. Evan Reddick Sarah Wright Huixia Zhang Lily Moncrief Barry d. bruce department of Biochemistry Cellular and Molecular Biology Graduate Program in Plant Physiology and Genetics Graduate School of Genome Science and Technology department of Botany department of BotanyUniversity of Tennessee Knoxville TN 37996 USA Present address: department of Infectious disease St. Jude Children's Research Hospital Memphis TN 38105 USA Present address: Institute of Molecular Biology University of Oregon Eugene OR 97403 USA present address: department of Microbiology University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390 USA Present address: Albert R. Mann Library Cornell University Ithaca NY 14850 USA present address: U.S. Food and drug Administration 10903 New Hampshire Avenue Silver Spring MD 20993 USA

Over 95% of plastid proteins are nuclear-encoded as their precursors containing an N-terminal extension known as the transit peptide （TP）. Although highly variable, TPs direct the precursors through a conserved, posttranslational mechanism involving translocons in the outer （TOC） and inner envelope （TOC）. The organelle import specificity is mediated by one or more components of the Toc complex. However, the high TP diversity creates a paradox on how the sequences can be specifically recognized. An emerging model of TP design is that they contain multiple loosely conserved motifs that are recognized at different steps in the targeting and transport process. Bioinformatics has demonstrated that many TPs contain semiconserved physicochemical motifs, termed FGLK. In order to characterize FGLK motifs in TP recognition and import, we have analyzed two well-studied TPs from the precursor of RuBisCO small subunit （SStp） and ferredoxin （Fdtp）. Both SStp and Fdtp contain two FGLK motifs. Analysis of large set mutations （-85） in these two motifs using in vitro, in organello, and in vivo approaches support a model in which the FGLK domains mediate interaction with TOC34 and possibly other TOC components. In vivo import analysis suggests that multiple FGLK motifs are functionally redundant. Furthermore, we discuss how FGLK motifs are required for efficient precursor protein import and how these elements may permit a convergent function of this highly variable class of targeting sequences.

关键词： chloroplast biology protein translocation Toc34 transit peptide cell biology

A convolutional neural network for defect classification in Bragg coherent X-ray diffraction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1026-1033页

作者： bruce Lim Ewen Bellec Maxime dupraz Steven Leake Andrea Resta Alessandro Coati Michael Sprung Ehud Almog Eugen Rabkin Tobias Schulli Marie-Ingrid Richard Grenoble INP-Phelma Univ.Grenoble AlpesGrenobleFrance ESRF-The European Synchrotron GrenobleFrance CEA Grenoble IRIGMEMNRSUniv.Grenoble AlpesGrenobleFrance Synchrotron SOLEIL L’Orme des MerisiersGif-sur-YvetteFrance deutsches Elektronen-Synchrotron(dESY) HamburgGermany department of Materials Science and Engineering Technion-Israel Institute of TechnologyHaifaIsrael

Coherent diffraction imaging enables the imaging of individual defects,such as dislocations or stacking faults,in *** defects and their surrounding elastic strain fields have a critical influence on the macroscopic properties and functionality of ***,their identification in Bragg coherent diffraction imaging remains a challenge and requires significant data *** ability to identify defects from the diffraction pattern alone would be a significant advantage when targeting specific defect types and accelerates experiment design and ***,we exploit a computational tool based on a three-dimensional(3d)parametric atomistic model and a convolutional neural network to predict dislocations in a crystal from its 3d coherent diffraction *** diffraction patterns from several thousands of relaxed atomistic configurations of nanocrystals are used to train the neural network and to predict the presence or absence of dislocations as well as their type(screw or edge).Our study paves the way for defect-recognition in 3d coherent diffraction patterns for material science.

关键词： materials coherent defect

Taming the Fire of Nephrotoxic Botanicals

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 Traditional Chinese Medicine 2019年第3期5卷 151-168页

作者： Francesca Holden Vanisha Amin dominic Kuek Jeffrey BKopp bruce MHendry Qi-He Xu department of Renal Medicine Centre for Integrative Chinese MedicineSchool of Immunology and Microbial SciencesFaculty of Life Sciences and MedicineKing’s College LondonWestern Education Centre GKT School of Medical Education Faculty of Life Sciences and MedicineKing’s College LondonLondonUnited Kingdom Kidney disease Section NIDDKNational Institutes of HealthBethesdaMDUSA

Criteria for diagnosing nephropathy and urothelial neoplasms induced by botanicals containing aristolochic acids(AAs) are well established. Highlights of recent research on AAs include mechanisms of AA intrarenal transport and metabolism and vigorous debate on whether AAs may also cause liver cancers. Many other botanicals may also cause renal injury, but a generalized framework for diagnosing botanical-induced kidney injury(BIKI) is lacking. Based on what we have learnt about the wide spectrum of phenotypes of BIKI attributed to AAs and a recently published standardized phenotypic framework of drug-induced kidney disease, we propose that BIKI may be categorized into six phenotypes(acute kidney injury, tubular dysfunction, glomerular disorders, nephrolithiasis, chronic kidney disease, and neoplasms) and four mechanistic types(A, predictable;B, idiosyncratic;C, chronic;and d, delayed). We call for international cooperation assembling a task force to develop, refine, and regularly appraise an online BIKI database, documenting botanical use, phenotypes, mechanisms, and levels of evidence. Once established, such a database may be linked with electronic patient records and pharmacovigilance channels to generate alerts, guide clinical decision-making, direct future research, and support evidence-based regulation of herbal medicines and education of healthcare professionals and the public. Finally, to prevent BIKI, we propose that a proactive approach integrating the triad of botanicals, users, and stakeholders will be needed.

关键词： Adverse effects database herbal kidney mechanisms phenotypes prevention

维普期刊数据库

Radiation Use Efficiency of Cotton in Contrasting Environments

在线全文

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2012年第5期3卷 649-654页

作者： Evangelos d. Gonias derrick M. Oosterhuis Androniki C. Bibi bruce A. Roberts department of Crop Soil and Environmental Sciences University of Arkansas Fayetteville USA Plant Science department California State University Fresno USA

Crop growth and yield varies among locations due to differences in environmental parameters, such as temperature, relative humidity, solar radiation and vapor pressure deficit. Previous research has shown that increasing vapor pressure deficit has a negative effect on radiation use efficiency of many crops. In this study, the radiation use efficiency of cot-ton (Gossypium hirsutum L.) grown in two contrasting production environments, Arkansas and California, was evaluated for two years, in 2006 and 2007. Temperature, relative humidity, vapor pressure deficit and photosyntheti-cally active radiation were recorded at both locations. Although the crop in California accumulated more dry matter during the period of the study, the radiation use efficiency was found to be lower compared to Arkansas. Radiation use efficiency for the Arkansas and California locations was estimated at 2.060 and 1.518 g?MJ–1 of intercepted photosynthetically active radiation, respectively. The higher productivity observed in California can be attributed to larger amounts of incident and intercepted radiation in this location. Radiation use efficiency of cotton was estimated to decrease with increasing vapor pressure deficit by a slope of –0.47 g?MJ–1?kPa–1.

关键词： dry Matter Environment Gossypium hirsutum L. Light Interception Radiation Use Efficiency Vapor Pressure deficit

Evaluation of utility in shoulder pathology:Correlating the American Shoulder and Elbow Surgeons and Constant scores to the EuroQoL

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 Orthopedics 2012年第3期3卷 20-24页

作者： Blaine T Bafus Richard E Hughes bruce S Miller James E Carpenter department of Orthopaedic Surgery Cleveland Clinic Foundation Cleveland OH 44115-2325 United States department of Orthopaedic Surgery University of Michigan Ann Arbor MI 48109-2200 United States

AIM: To study whether health utility scores can be derived from shoulder-specific ***: Authors investigated two questions:(1) do the American Shoulder and Elbow Surgeons(ASES) score and the Constant score correlate with the EuroQo L(EQ-5d), a measure of health utility?(2) can the ASES and Constant scores be obtained from a complete study sample without bias? Thirty subjects with various shoulder diagnoses completed ASES, Constant, and EQ-5d instruments. Pearson correlations were calculated to assess the associations between EQ-5d score and ASES and Constant ***: The correlation between EQ-5d score and ASES score was 0.60(P d and Constant scores(P del containing ASES score, Constant score, age, and gender failed to adequately predict EQ-5d. Moreover, 25% of patients meeting the inclusion criteria did not complete the ASES questionnaire because they did not feel that specific questions, such as "do usual sport-list" and "throw ball overhand," applied to ***: Authors' results do not support the use of the ASES and Constant scores in predicting EuroQ ol health utility values. However, the Constant score was more suitable for this patient population because all patients were able to complete it.

关键词： Utility EuroQoL American Shoulder and Elbow Surgeons score Constant score Shoulder Outcomes

Assessment of mixture toxicity of Cu,Cd and a photooxidized PAH phenanthrenequinone to Vibrio fischeri

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Assessment of mixture toxicity of Cu,Cd and a photooxidized ...

Long-lived kimberlite magmatism in the Central Saskatchewan area（central North America） recorded by zircon megacrysts from the Fort à la Corne field

河南省植保学会第八次、河南省昆虫学会第七次、河南省植病学会第二次会员代表大会暨学术讨论会

作者： Mark A.Lampi d.George dixon bruce M.Greenberg department of Biology University of Waterloo Waterloo Ontario N2L 3B8 Canada department of Biology University of Waterloo Waterloo Ontario N2L 3B8 Canada department of Biology University of Waterloo Waterloo Ontario N2L 3B8 Canada

Transition metals and polycyclic aromatic hydrocarbons (PAHs) are co-contaminants at many sites. Contaminants in mixtures are known to interact with biological systems in ways that can greatly alter the toxicity of individual compounds. The toxicity (alone and in mixture) of Cu (a redox-active metal), Cd (a non-redox active metal) and phenanthrenequinone (PHQ) (a redox-active oxygenated PAH) were examined using the bioluminescent bacterium Vibrio fischeri. The co-toxicity of Cu/PHQ depend on their mixture ratio. different interaction types (synergistism, antagonism, and additive) were observed in different combinations. The interaction types change from antagonism at a low Cu/PHQ ratio (1/4) to additive at intermediate Cu/PHQ ratio (2/3) to synergistic at higher Cu/PHQ ratios (3/2 and 4/1). In contrast to Cu/PHQ, the co-toxicity of Cd/PHQ did not change at different mixture ratios. The interaction types basically are additive. ROS-mediated toxic mechanisms of Cu, Cd and PHQ have been well established with several organisms using 2',7'-dichlorofluorescin diacetate (dCF ***) and Amplex Red fluorescence. Enhanced ROS production was observed in V. fischeri treated with the individual chemicals and their mixtures, suggesting alone and mixture toxicity of Cu, Cd and PHQ to V. fischeri involve ROS mechanisms. This study shows that not only the chemical mixtures, but also the mixture ratios can alter individual chemical toxicity and should be taken into account in risk assessment.

关键词： Mixture toxicity Copper Cadmium phenanthrenequinone (PHQ) Reactive oxygen species Vibrio fischeri polycyclic aromatic hydrocarbons (PAHs)

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Long-lived kimberlite magmatism in the Central Saskatchewan ...

第八届全国成矿理论与找矿方法学术讨论会

作者：舒巧 d.Graham Pearson bruce A.Kjargaard Greg Read Institute of Geochemistry Chinese Academy of Sciences dept. of Earth and Atmospheric Sciences University of Alberta Geological Survey of Canada

＜正＞Zircon megacrysts from kimberlites appear to have a direct relationship to the magmatic activity that lead to the eruption of their host kimberlites because i)they yield kimberlite eruption ages（davis,1977）and ii)their trace element patterns and contents significantly differ from crustal zircons,most significantly by the absence of a negative Eu anomaly（Belousova et al.,2002）.These are also the features of a large suite of zircon megacrysts separated during ore-body evaluation from the kimberlites of Fortàla Corne,central Saskatchewan that erupt

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

阅读训练对儿童早期字词意识发展的作用

心理科学 2002年第6期25卷 672-675页

作者：徐芬 bruce Homer Kang Lee 北京师范大学认知科学与学习教育部重点实验室北京100875 New York University Queen’s University

该研究探讨了幼儿园中、大班及小学一、二年级儿童在完成字 /词意识任务上的年龄差异以及阅读训练对字 /词意识发展的影响。实验结果表明 :(1) 5岁儿童的字词意识尚处于不断的发展之中。 6岁及 7岁儿童的字意识发展已经达到了成熟水平 ... 详细信息

该研究探讨了幼儿园中、大班及小学一、二年级儿童在完成字 /词意识任务上的年龄差异以及阅读训练对字 /词意识发展的影响。实验结果表明 :(1) 5岁儿童的字词意识尚处于不断的发展之中。 6岁及 7岁儿童的字意识发展已经达到了成熟水平 ;但他们的词意识正处于不断的发展之中。 (2 )初级的阅读训练促进了5岁儿童字意识的发展 ,但对词意识的发展没有影响。 (3)小学语文教学对 6岁儿童的口头任务没有影响 ,但显著地促进了圈词任务成绩的提高。

关键词：阅读训练儿童早期字词意识作用词意识字意识发展元语言意识

维普期刊数据库

在线全文

学校读者我要写书评

暂无评论

袖珍设备电池稳压器设计考虑

电子设计技术 1994年第10期 39-40+43-45页

作者： bruce d.Moore

使用四节硷性AA电池构成稳压器作为袖珍电子设备的电源,不仅应该能调节,而且也具备效率高、补偿电流和体积小等功能, 从而引出了各种稳压器结构的设计,供设计人员选择。

关键词：稳压器四节电源输入电压电池组峰值电流