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学前语言教育的新取向:重视儿童学业语言的发展 被引量:31
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作者 周兢 陈思 +1 位作者 Catherine snow Paola Uccelli 《学前教育研究》 CSSCI 北大核心 2014年第6期39-44,共6页
目前国际语言与教育的研究特别关注儿童学业语言的发展和教育。学业语言是儿童语言发展过程中所学习运用的一种特别的语言能力。学业语言是一种可以通过口头语言进行交流,但是具有书面语言特征的语言。学前阶段儿童的学业语言发展具有... 目前国际语言与教育的研究特别关注儿童学业语言的发展和教育。学业语言是儿童语言发展过程中所学习运用的一种特别的语言能力。学业语言是一种可以通过口头语言进行交流,但是具有书面语言特征的语言。学前阶段儿童的学业语言发展具有自身的年龄特点。幼教工作者应该认识到阅读是通向儿童学业语言成长的重要途径;应在阅读基础上或者围绕某个学习内容开展拓展性讨论;应关注说明性讲述活动,帮助学前儿童系统使用学业语言进行表达。 展开更多
关键词 语言学习 学业语言 语言教育
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学业语言:教育必须重视的学习者语言能力构建 被引量:17
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作者 周兢 陈思 +1 位作者 Catherine snow Paola Uccelli 《全球教育展望》 CSSCI 北大核心 2013年第12期75-81,共7页
本文综合和归纳了国际范围近年来对学业语言这一热点话题研究和探索的最新进展,讨论了学业语言的发展与儿童阅读、其他学科的学业水平之间的关系、阐述了学业语言概念的核心内涵、儿童学业语言能力的发展变化规律,以及教育者应如何在实... 本文综合和归纳了国际范围近年来对学业语言这一热点话题研究和探索的最新进展,讨论了学业语言的发展与儿童阅读、其他学科的学业水平之间的关系、阐述了学业语言概念的核心内涵、儿童学业语言能力的发展变化规律,以及教育者应如何在实际的学科教学中渗透学业语言的概念,帮助儿童学业语言获得进步。 展开更多
关键词 学业语言 读写发展 语言教育
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砷对NIH 3T3细胞谷胱甘肽水平、相关酶活性及其基因表达的影响 被引量:8
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作者 胡宇 金喜梅 +1 位作者 王国荃 snow Elizabeth T 《环境与职业医学》 CAS 北大核心 2003年第6期396-402,共7页
[目的]探讨急性、慢性砷暴露对小鼠成纤维细胞 (NIH3T3细胞 )氧化还原状态的影响 ,进而探讨其对细胞谷胱甘肽 (GSH)水平、相关酶活性及其基因表达的影响。[方法]将经过不同浓度砷处理的细胞 ,抽提细胞总蛋白。采用经过改进的Clark法测... [目的]探讨急性、慢性砷暴露对小鼠成纤维细胞 (NIH3T3细胞 )氧化还原状态的影响 ,进而探讨其对细胞谷胱甘肽 (GSH)水平、相关酶活性及其基因表达的影响。[方法]将经过不同浓度砷处理的细胞 ,抽提细胞总蛋白。采用经过改进的Clark法测定细胞中谷胱甘肽 ;采用Thomas法测定谷胱甘肽还原酶 (GR)活性 ;使用分光光度法测定谷胱甘肽与1 氯 2 ,4 二硝基苯 (CDNB)的结合以确定谷胱甘肽转移酶 (GST)活性。采用SDS聚丙烯酰胺凝胶电泳和固定化蛋白质的免疫学测定法测定血红素氧化酶 (HO 1)蛋白表达 ;采用RNA印迹法测定谷胱甘肽还原酶 (GR)和谷胱甘肽过氧化物酶(GSH Px)的基因表达。[结果]急性砷处理细胞在较低浓度范围可以引起GSH水平的增加 ;而当砷浓度高于25μmol/L时 ,GSH水平降低 ;在0.1和0.5 μmol/L慢性染毒之后细胞GSH水平明显降低。然而 ,在急性和慢性砷处理组GST和GR的活性均有升高 ,而在高浓度24h处理组则显著降低 ;GR的mRNA水平与GR的活性相一致 ,在急、慢性染毒组中均表现为GR的mRNA表达上调 ;砷可以引起血红素氧化酶 1(HO 1)蛋白水平的增加。急性、慢性砷处理均引起GSH Px mRNA表达下调。[结论]三价砷可以引起氧化应激、GSH水平改变、以及相关酶活性及其基因表达的改变 ,急性与慢性砷接触对GSH系统? 展开更多
关键词 谷胱甘肽 基因表达 酶活性 氧化还原状态 成纤维细胞 致病机制
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Endoscopic submucosal dissection vs endoscopic mucosal resection for colorectal polyps:A meta-analysis and metaregression with single arm analysis 被引量:9
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作者 Xiong Chang Lim Kameswara Rishi Yeshayahu Nistala +5 位作者 Cheng Han Ng snow Yunni Lin Darren Jun Hao Tan Khek-Yu Ho Choon-Seng Chong Mark Muthiah 《World Journal of Gastroenterology》 SCIE CAS 2021年第25期3925-3939,共15页
BACKGROUND Endoscopic submucosal dissection(ESD)has shown to be effective in management of colorectal neoplasm in the Asian countries,while its implementation in Western countries where endoscopic mucosal resection(EM... BACKGROUND Endoscopic submucosal dissection(ESD)has shown to be effective in management of colorectal neoplasm in the Asian countries,while its implementation in Western countries where endoscopic mucosal resection(EMR)is preferred is still debatable.AIM To compare the surgical,histological,and oncological outcomes between ESD and EMR in the treatment of colorectal polyps,with subgroup analysis comparing the efficacy of ESD and EMR between Japan and the rest of the world.METHODS Embase and Medline databases were searched from inception to October 2020 in accordance with PRISMA guidelines for studies comparing en bloc,complete resection,margin involvement,resection time,need for additional surgery,complications,and recurrence rate of ESD with EMR.RESULTS Of 281344 colorectal polyps from 21 studies were included.When compared to EMR,the pooled analysis revealed ESD was associated with higher en bloc and complete resection rate,and lower lateral margin involvement and recurrence.ESD led to increased procedural time,need for additional surgery,and perforation risk.No significant difference in bleeding risk was found between the two groups.Meta-regression analysis suggested only right colonic polyps correlated with an increased perforation risk in ESD.Confounders including polyp size and invasion depth did not significantly influence the en bloc and complete resection rate,bleeding risk and recurrence.In subgroup analysis,Japan performed better than the rest of the world in both ESD and EMR with perforation risk of 4%and 0.0002%,respectively,as compared to perforation risk of 8%and 1%,respectively,in reports coming from rest of the world.CONCLUSION ESD resulted in better resection outcomes and lower recurrence compared to EMR.With appropriate training,ESD is preferred over EMR as the first-line therapy for resection of colorectal polyps,without restricting to lesions greater than 20 mm and those with high suspicion of submucosal invasion. 展开更多
关键词 Endoscopic mucosal resection ENDOSCOPY Colonic polyps Colorectal neoplasm COLONOSCOPY
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Arthroscopic treatment options for irreparable rotator cuff tears of the shoulder 被引量:8
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作者 Cameron M Anley Samuel KL Chan Martyn snow 《World Journal of Orthopedics》 2014年第5期557-565,共9页
The management of patients with irreparable rotator cuff tears remains a challenge for orthopaedic surgeons with the final treatment option in many algorithms being either a reverse shoulder arthroplasty or a tendon t... The management of patients with irreparable rotator cuff tears remains a challenge for orthopaedic surgeons with the final treatment option in many algorithms being either a reverse shoulder arthroplasty or a tendon transfer. The long term results of these procedures are however still widely debated, especially in younger patients. A variety of arthroscopic treatment options have been proposed for patients with an irreparable rotator cuff tear without the presence of arthritis of the glenohumeral joint. These include a simple debridement with or without a biceps tenotomy, partial rotator cuff repair with or without an interval slide, tuberplasty, graft interposition of the rotator cuff, suprascapular nerve ablation, superior capsule reconstruction and insertion of a biodegradable spacer(Inspace) to depress the humeral head. These options should be considered as part of the treatment algorithm in patients with an irreparable rotator cuff and could be used as either as an interim procedure, delaying the need for more invasive surgery in the physiologically young and active, or as potential definitive procedures in the medically unfit.The aim of this review is to highlight and summarise arthroscopic procedures and the results thereof currently utilised in the management of these challenging patients. 展开更多
关键词 Irreparable ARTHROSCOPY ROTATOR CUFF Repair MASSIVE
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A one-dimensional heat transfer model of the Antarctic Ice Sheet and modeling of snow temperatures at Dome A, the summit of Antarctic Plateau 被引量:7
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作者 CHEN BaiLian1,3, ZHANG RenHe2, SUN ShuFen1, BIAN LinGen2, XIAO CunDe4,2 & ZHANG TingJun5 1 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 2 Chinese Academy of Meteorological Sciences, Beijing 100081, China +2 位作者 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 4 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 5 The National snow and Ice Data Center, University of Colorado, Boulder, CO 80309-0449, USA 《Science China Earth Sciences》 SCIE EI CAS 2010年第5期763-772,共10页
A vertical one-dimensional numerical model for heat transferring within the near-surface snow layer of the Antarctic Ice Sheet was developed based on simplified parameterizations of associated physical processes for t... A vertical one-dimensional numerical model for heat transferring within the near-surface snow layer of the Antarctic Ice Sheet was developed based on simplified parameterizations of associated physical processes for the atmosphere, radiation, and snow/ice systems. Using the meteorological data of an automatic weather station (AWS) at Dome A (80°22′S, 70°22′E), we applied the model to simulate the seasonal temperature variation within a depth of 20 m. Comparison of modeled results with observed snow temperatures at 4 measurement depths (0.1, 1, 3, 10 m) shows good agreement and consistent seasonal variations. The model results reveal the vertical temperature structure within the near-surface snow layer and its seasonal variance with more details than those by limited measurements. Analyses on the model outputs of the surface energy fluxes show that: 1) the surface energy balance at Dome A is characterized by the compensation between negative net radiation and the positive sensible fluxes, and 2) the sensible heat is on average transported from the atmosphere to the snow, and has an evident increase in spring. The results are considered well representative for the highest interior Antarctic Plateau. 展开更多
关键词 ANTARCTIC Ice Sheet NEAR-SURFACE layer energy transfer numerical model
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Proteoglycans: Road Signs for Neurite Outgrowth 被引量:6
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作者 Justin A.Beller Diane M.snow 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第4期343-355,共13页
Proteoglycans in the central nervous system play integral roles as "traffic signals" for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central n... Proteoglycans in the central nervous system play integral roles as "traffic signals" for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central nervous system. In this review, the structures of proteoglycans and the evidence suggesting their involvement in the response following spinal cord injury are presented. The review further describes the methods routinely used to determine the effect proteoglycans have on neurite outgrowth. The effects of proteoglycans on neurite outgrowth are not completely understood as there is disagreement on what component of the molecule is interacting with growing neurites and this ambiguity is chronicled in an historical context. Finally, the most recent findings suggesting possible receptors, interactions, and sulfation patterns that may be important in eliciting the effect of proteoglycans on neurite outgrowth are discussed. A greater understanding of the proteoglycan-neurite interaction is necessary for successfully promoting regeneration in the iniured central nervous system. 展开更多
关键词 chondroitin sulfate proteoglycans heparan sulfate proteoglycans GLYCOSAMINOGLYCANS protein core extracellular matrix neuronal growth cones axon outgrowth and regeneration spinalcord injury glial scar tissue culture
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感情里的安全感是谁给的
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作者 snow 《学习之友》 2024年第3期12-13,共2页
我一直是个没有安全感的人。小学四五年级时,我的同桌是我最好的朋友,我们无话不谈,连上厕所也要手拉手一起去。我一直以为,这份友谊只属于我们两个人。直到六年级我们被分到不同的班级后,我第一次对我们的关系产生了焦虑。因为我发现,... 我一直是个没有安全感的人。小学四五年级时,我的同桌是我最好的朋友,我们无话不谈,连上厕所也要手拉手一起去。我一直以为,这份友谊只属于我们两个人。直到六年级我们被分到不同的班级后,我第一次对我们的关系产生了焦虑。因为我发现,刚一开学,好朋友就已经和她的新同桌混熟了。每次看到她们并肩从我的教室门口经过的时候,我都会在座位上独自难过。 展开更多
关键词 手拉手 安全感 四五年级 小学 班级 同桌
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Three-dimensional perfused human in vitro model of nonalcoholic fatty liver disease 被引量:5
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作者 Tomasz Kostrzewski Terri Cornforth +4 位作者 Sophie A snow Larissa Ouro-Gnao Cliff Rowe Emma M Large David J Hughes 《World Journal of Gastroenterology》 SCIE CAS 2017年第2期204-215,共12页
AIM To develop a human in vitro model of non-alcoholic fatty liver disease(NAFLD), utilising primary hepatocytes cultured in a three-dimensional(3D) perfused platform. METHODS Fat and lean culture media were developed... AIM To develop a human in vitro model of non-alcoholic fatty liver disease(NAFLD), utilising primary hepatocytes cultured in a three-dimensional(3D) perfused platform. METHODS Fat and lean culture media were developed to directly investigate the effects of fat loading on primary hepatocytes cultured in a 3D perfused culture system. Oil Red O staining was used to measure fat loading in the hepatocytes and the consumption of free fatty acids(FFA) from culture medium was monitored. Hepatic functions, gene expression profiles and adipokine release were compared for cells cultured in fat and lean conditions. To determine if fat loading in the system could be modulated hepatocytes were treated with known anti-steatotic compounds. RESULTS Hepatocytes cultured in fat medium were found to accumulate three times more fat than lean cells and fat uptake was continuous over a 14-d culture. Fat loading of hepatocytes did not cause any hepatotoxicity and significantly increased albumin production. Numerous adipokines were expressed by fatty cells and genes associated with NAFLD and liver disease were upregulated including: Insulin-like growth factorbinding protein 1, fatty acid-binding protein 3 and CYP7A1. The metabolic activity of hepatocytes cultured in fatty conditions was found to be impaired and the activities of CYP3A4 and CYP2C9 were significantlyreduced, similar to observations made in NAFLD patients. The utility of the model for drug screening was demonstrated by measuring the effects of known antisteatotic compounds. Hepatocytes, cultured under fatty conditions and treated with metformin, had a reduced cellular fat content compared to untreated controls and consumed less FFA from cell culture medium.CONCLUSION The 3D in vitro NAFLD model recapitulates many features of clinical NAFLD and is an ideal tool for analysing the efficacy of anti-steatotic compounds. 展开更多
关键词 Non-alcoholic fatty liver disease Liver disease Three-dimensional cell culture Organ-on-chip Primary cell culture Fatty liver HEPATOCYTES
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Foregut bypass vs.restrictive bariatric procedures for nonalcoholic fatty liver disease:a meta-analysis of 3,355 individuals 被引量:1
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作者 Wen Hui Lim snow Yunni Lin +17 位作者 Cheng Han Ng Darren Jun Hao Tan Jieling Xiao Jie Ning Yong Phoebe Wen Lin Tay Nicholas Syn Yip Han Chin Kai En Chan Chin Meng Khoo Nicholas Chew Roger S.Y.Foo Asim Shabbir Eunice X.Tan Daniel Q.Huang Mazen Noureddin Arun J.Sanyal Mohammad Shadab Siddiqui Mark D.Muthiah 《Hepatobiliary Surgery and Nutrition》 SCIE 2023年第5期658-670,I0001-I0003,共16页
Background:Bariatric surgery represents an important treatment option for severely obese patients with nonalcoholic fatty liver disease(NAFLD).However,there remains inadequate data regarding the effects of different b... Background:Bariatric surgery represents an important treatment option for severely obese patients with nonalcoholic fatty liver disease(NAFLD).However,there remains inadequate data regarding the effects of different bariatric procedures on various NAFLD parameters,especially for histological outcomes.Thus,this meta-analysis aimed to compare the effects of restrictive bariatric procedures and foregut bypass on the metabolic,biochemical,and histological parameters for patients with NAFLD.Methods:Medline and Embase were searched for articles relating to bariatric procedures and NAFLD.Pairwise meta-analysis was conducted to compare efficacy of bariatric procedures pre-vs.post-procedure with subgroup analysis to further compare restrictive against foregut bypass procedures.Results:Thirty-one articles involving 3,355 patients who underwent restrictive bariatric procedures(n=1,460)and foregut bypass(n=1,895)were included.Both foregut bypass(P<0.01)and restrictive procedures(P=0.03)significantly increased odds of fibrosis resolution.Compared to restrictive procedures,foregut bypass resulted in a borderline non-significant decrease in fibrosis score(P=0.06)and significantly lower steatosis score(P<0.001).For metabolic parameters,foregut bypass significantly lowered body mass index(P=0.003)and low-density lipoprotein(P=0.008)compared to restrictive procedures.No significant differences were observed between both procedures for aspartate aminotransferase(P=0.17)and alkaline phosphatase(P=0.61).However,foregut bypass resulted in significantly lower gamma-glutamyl transferase than restrictive procedures(P=0.01)while restrictive procedures resulted in significantly lower alanine transaminase than foregut bypass(P=0.02).Conclusions:The significant histological and metabolic advantages and comparable improvements in biochemical outcomes support the choice of foregut bypass over restrictive bariatric procedures in NAFLD management. 展开更多
关键词 Bariatric surgery non-alcoholic fatty liver disease(NAFLD) obesity FIBROSIS ENDOSCOPY
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Enabling rapid X-ray CT characterisation for additive manufacturing using CAD models and deep learning-based reconstruction 被引量:1
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作者 Amirkoushyar Ziabari S.V.Venkatakrishnan +10 位作者 Zackary snow Aleksander Lisovich Michael Sprayberry Paul Brackman Curtis Frederick Pradeep Bhattad Sarah Graham Philip Bingham Ryan Dehoff Alex Plotkowski Vincent Paquit 《npj Computational Materials》 SCIE EI CSCD 2023年第1期1443-1452,共10页
Metal additive manufacturing(AM)offers flexibility and cost-effectiveness for printing complex parts but is limited to few alloys.Qualifying new alloys requires process parameter optimisation to produce consistent,hig... Metal additive manufacturing(AM)offers flexibility and cost-effectiveness for printing complex parts but is limited to few alloys.Qualifying new alloys requires process parameter optimisation to produce consistent,high-quality components.High-resolution X-ray computed tomography(XCT)has not been effective for this task due to artifacts,slow scan speed,and costs.We propose a deep learning-based approach for rapid XCT acquisition and reconstruction of metal AM parts,leveraging computer-aided design models and physics-based simulations of nonlinear interactions between X-ray radiation and metals.This significantly reduces beam hardening and common XCT artifacts.We demonstrate high-throughput characterisation of over a hundred AlCe alloy components,quantifying improvements in characterisation time and quality compared to high-resolution microscopy and pycnometry.Our approach facilitates investigating the impact of process parameters and their geometry dependence in metal AM. 展开更多
关键词 RAPID ALLOY CHARACTER
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Knee salvage procedures: The indications, techniques and outcomes of large osteochondral allografts 被引量:4
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作者 Karen Chui Lee Jeys Martyn snow 《World Journal of Orthopedics》 2015年第3期340-350,共11页
The overall incidence of osteochondral defect in the general population is estimated to be 15 to 30 per100000 people.These lesions can become symptomatic causing pain,swelling and decreased function of the knee,and ma... The overall incidence of osteochondral defect in the general population is estimated to be 15 to 30 per100000 people.These lesions can become symptomatic causing pain,swelling and decreased function of the knee,and may eventually progress to osteoarthritis.In the young and active population,partial or total knee arthroplasty(TKA)is rarely the treatment of choice due to risk of early failure.Osteochondral allograft transplantation has been demonstrated to be a safe and effective treatment of large osteochondral and chondral defects of the knee in appropriately selected patients.The treatment reduces pain,improves function and is a viable limb salvage procedure for patients,especially young and active patients for whom TKA is not recommended.Either large dowels generated with commercially available equipment or free hand shell allografts can be implanted in more posterior lesions.Current recommendations for fresh allografts stored at4C advise implantation within 21-28 d of procurement for optimum chondrocyte viability,following screening and testing protocols.Higher rates of successful allograft transplantation are observed in younger patients,unipolar lesions,normal or corrected malalignment,and defects that are treated within 12 mo of symptom onset.Patients with bipolar lesions,uncorrectable malalignment,advanced osteoarthritis,and those over40 tend to have less favourable outcomes. 展开更多
关键词 OSTEOCHONDRAL ALLOGRAFT KNEE SALVAGE Shell Dowel
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砷对人DNA连接酶影响的研究 被引量:2
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作者 胡宇 苏林 +1 位作者 Elithabeth T.snow 王国荃 《地方病通报》 2000年第1期7-10,共4页
采用纯化酶活性分析和人细胞体外培养方法 ,研究砷对人 DNA修复关键酶—— DNA连接酶活性的影响。结果表明 :纯化人 DNA连接酶 和 在毫摩尔水平三价砷和五价砷存在下 ,酶活性增加。与此不同的是 ,经过微摩尔砷处理的人细胞核提取物的 ... 采用纯化酶活性分析和人细胞体外培养方法 ,研究砷对人 DNA修复关键酶—— DNA连接酶活性的影响。结果表明 :纯化人 DNA连接酶 和 在毫摩尔水平三价砷和五价砷存在下 ,酶活性增加。与此不同的是 ,经过微摩尔砷处理的人细胞核提取物的 DNA连接酶的活性即可被显著抑制。未经染砷处理的细胞核提取物的 DNA连接酶活性与纯化酶对砷的敏感性没有显著区别。说明砷的毒性与砷对 DNA连接酶的作用没有直接联系。因此 ,砷的促突变和对 DNA’损伤后修复的抑制 ,可能并非直接抑制修复酶所致 ,可能与砷所引起的细胞内信号传递和基因表达的改变及通过转录水平或翻译修饰的调节有关。 展开更多
关键词 DNA连接酶 肿瘤
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爱对人的感觉
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作者 snow 《北方人》 2023年第9期34-36,共3页
12020年我领养了一只橘猫,给它取名叫芬达。芬达曾经是一只校园流浪猫,救助它的老师把它送来我家时,说它年龄.不详,目测在四岁左右。
关键词 流浪猫 人的感觉 老师
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泛青藏高原高寒植物多样性的形成与演化
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作者 丁文娜 星耀武 《植物科学学报》 CAS CSCD 北大核心 2023年第6期729-740,共12页
泛青藏高原地区拥有全球最丰富的高寒植物多样性,是生物多样性热点地区中的热点,也是研究地球环境演化与生物多样性演变过程的理想地区。该地区已经开展了大量谱系地理、生物地理学和进化生态学研究,对我们认识该地区的生物多样性演化... 泛青藏高原地区拥有全球最丰富的高寒植物多样性,是生物多样性热点地区中的热点,也是研究地球环境演化与生物多样性演变过程的理想地区。该地区已经开展了大量谱系地理、生物地理学和进化生态学研究,对我们认识该地区的生物多样性演化及其维持机制具有重要意义。随着对青藏高原各地块构造演化历史研究的加深,该地区的生物多样性研究已经逐步迈入到地质-气候-生物过程的交叉研究。本文分析了青藏高原及其周边地区地质构造演化的最新研究进展,区分了青藏高原腹地、喜马拉雅和横断山,然后从青藏-喜马拉雅-横断山地区高寒植物多样性的起源及演化节奏、高寒植物的成分来源和区系交流以及高寒植物多样化的驱动因素等3方面总结了该地区高寒植物多样性的演化历史。最后,我们进一步提出在洲际或全球尺度上探讨不同地区高寒植物多样性演化历史的异同和联系,以及对高寒植物适应性进化策略的研究,以期深入理解高寒植物多样性分布格局的成因及其维持机制。 展开更多
关键词 生物多样性 高寒植物 宏观演化 横断山
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砷诱导NIH3T3细胞转化模型的建立 被引量:2
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作者 胡宇 金喜梅 +1 位作者 王国荃 snow ET 《新疆医科大学学报》 CAS 2004年第1期1-5,共5页
目的 :为进行砷诱导细胞转化的分子机制研究建立砷诱导的细胞转化模型。方法:选择 NIH 3T3小鼠成纤维细胞作为研究对象。通过细胞砷毒性实验 ,分别选择 0 .1、0 .5μm ol/ L As( )作为诱导剂量染毒诱导 ,同时设立两个对照组同步进行培... 目的 :为进行砷诱导细胞转化的分子机制研究建立砷诱导的细胞转化模型。方法:选择 NIH 3T3小鼠成纤维细胞作为研究对象。通过细胞砷毒性实验 ,分别选择 0 .1、0 .5μm ol/ L As( )作为诱导剂量染毒诱导 ,同时设立两个对照组同步进行培养和传代。观察比较 As( )处理组和对照组细胞的形态、生物学生长特性、细胞砷毒性的变化 ,并进行半固定琼脂生长实验以确定细胞转化模型。结果 :NIH3T3细胞经 0 .1、0 .5 μm ol/ L As( ) 110d的长期低剂量诱导后发生了细胞生物学改变 ,主要表现为 :细胞呈复层生长 ,倍增时间明显缩短 ;细胞寿命由体外有限传代 (约 30代左右 )变为体外无限传代 ;0 .1μmol/ L As( )组细胞在半固体琼脂上生长并形成细胞集落。结论 :慢性低剂量砷暴露可以诱导细胞转化 ,该模型的建立及其相关实验技术条件的确立可应用于砷诱导细胞转化的有关分子机制的进一步研究。 展开更多
关键词 细胞转化 分子机制
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全球气候研究计划 (WCRP)中的气候与冰冻圈项目 (CliC) :冰冻圈与气候的优先研究领域 (英) 被引量:2
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作者 Roger G. Barry (National snow and Ice Data Center, University of Colorado, Boulder, CO, 80309-0449, USA) 《冰川冻土》 CSCD 北大核心 2002年第5期523-525,共3页
The cryosphere is an integral part of the global climate system, however, many aspects of the cryosphere have not been fully covered within WCRP. Issues relating to potential changes in the climate cryosphere system b... The cryosphere is an integral part of the global climate system, however, many aspects of the cryosphere have not been fully covered within WCRP. Issues relating to potential changes in the climate cryosphere system become more and more important in order to describes research and coordination initiatives required to integrate fully studies of impact and response of the cryosphere to climate change. The article also indicates the recent progress of CliC, and its future plan. 展开更多
关键词 全球气候研究计划 气候 冰冻圈
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Is colonic lavage a suitable alternative for left-sided colonic emergencies? 被引量:3
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作者 Hui Yu Tham Wen Hui Lim +6 位作者 Sneha Rajiv Jain Cheng Han Mg snow Yunni Lin Jie Ling Xiao Fung Joon Foo Kar Yong Wong Choon Seng Chong 《World Journal of Gastrointestinal Surgery》 SCIE 2021年第4期379-391,共13页
BACKGROUND The use of intra-operative colonic lavage(IOCL)with primary anastomosis remains controversial in the emergency left-sided large bowel pathologies,with alternatives including Hartmann’s procedure,manual dec... BACKGROUND The use of intra-operative colonic lavage(IOCL)with primary anastomosis remains controversial in the emergency left-sided large bowel pathologies,with alternatives including Hartmann’s procedure,manual decompression and subtotal colectomy.AIM To compare the peri-operative outcomes of IOCL to other procedures.METHODS Electronic databases were searched for articles employing IOCL from inception till July 13,2020.Odds ratio and weighted mean differences(WMD)were estimated for dichotomous and continuous outcomes respectively.Single-arm meta-analysis was conducted using DerSimonian and Laird random effects.RESULTS Of 28 studies were included in this meta-analysis,involving 1142 undergoing IOCL,and 634 other interventions.IOCL leads to comparable rates of wound infection when compared to Hartmann’s procedure,and anastomotic leak and wound infection when compared to manual decompression.There was a decreased length of hospital stay(WMD=-7.750;95%CI:-13.504 to-1.996;P=0.008)compared to manual decompression and an increased operating time.Single-arm meta-analysis found that overall mortality rates with IOCL was 4%(CI:0.03-0.05).Rates of anastomotic leak and wound infection were 3%(CI:0.02-0.04)and 12%(CI:0.09-0.16)respectively.CONCLUSION IOCL leads to similar rates of post-operative complications compared to other procedures.More extensive studies are needed to assess the outcomes of IOCL for emergency left-sided colonic surgeries. 展开更多
关键词 COLON Colonic irrigation Intra-operative colonic lavage ANASTOMOSIS Emergency surgery Colonic neoplasm
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氮素和磷素在草坪系统中的转化 被引量:2
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作者 James T.snow 肖飚 《国外畜牧学(草原与牧草)》 1995年第4期23-25,共3页
硝酸盐在草坪生态系统中的淋溶是变化无常的.影响硝酸盐淋溶的因素包括土壤类型,灌溉、降水、温度、氮肥的种类、用量及使用季节。着重研究了不同的草坪和气候区域中氮、磷化合物的转化。研究内容以氮的活动为主。 试验还没有完成,但目... 硝酸盐在草坪生态系统中的淋溶是变化无常的.影响硝酸盐淋溶的因素包括土壤类型,灌溉、降水、温度、氮肥的种类、用量及使用季节。着重研究了不同的草坪和气候区域中氮、磷化合物的转化。研究内容以氮的活动为主。 试验还没有完成,但目前获得的数据可以进行一些比较,其中包括所有项目中每年硝酸盐淋溶量的大体比较。不同气候区、不同土壤类型中硝酸盐的淋溶量比较。 展开更多
关键词 草坪 氮素 磷素 转化
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Commentary on:“Facilitating transparency in spinal cord injury studies using data standards and ontologies” 被引量:2
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作者 Diane M.snow 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第1期8-9,共2页
Commentary Most would agree that providing comprehensive detail in scientific reporting is critical for the development of mean- ingful therapies and treatments for diseases. Such stellar practices 1) allow for repro... Commentary Most would agree that providing comprehensive detail in scientific reporting is critical for the development of mean- ingful therapies and treatments for diseases. Such stellar practices 1) allow for reproduction of experiments to con- firm results, 2) promote thorough analyses of data, and 3) foster the incremental advancement of valid approaches. Unfortunately, most would also agree we have far to go to reach this vital goal (Hackam and Redelmeier, 2006; Prinz et al., 2011; Baker et al., 2014). 展开更多
关键词 data Commentary on Facilitating transparency in spinal cord injury studies using data standards and ontologies SCI
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