全文获取类型
收费全文 | 142篇 |
免费 | 18篇 |
国内免费 | 3篇 |
专业分类
163篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 12篇 |
2013年 | 21篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有163条查询结果,搜索用时 15 毫秒
111.
112.
《Biotechnic & histochemistry》2013,88(6):363-366
Wood material that is to be used for observation of starch content may be stored many months in several plant material fixatives, formalin-acetic-alcohol, formalin-propionic-alcohol, tertiary butyl alcohol, ethyl alcohol, and 5 and 10% aqueous formalin without any apparent deleterious effect on the starch granules Storage of wood in aqueous formalin solutions of 15% and higher concentrations caused starch granules to break down and disperse forming a coagulated mass, in which it was impossible to see the individual grains. 相似文献
113.
目的 长非编码RNA(lncRNAs)参与多种重要的生物学过程并与各种人类疾病密切相关,因此,lncRNA-疾病关联预测研究有助于疾病的诊断、治疗和在分子水平理解人类疾病的发生发展机制。目前,大多数lncRNA-疾病关联预测方法倾向于浅层整合lncRNA和疾病的相关信息,忽略网络拓扑结构中的深层嵌入特征;另外通过随机选取lncRNA-疾病非关联对构建负样本训练集合,影响预测方法的鲁棒性。方法 本文提出一种基于网络嵌入的NELDA方法,预测潜在的lncRNA-疾病关联关系。NELDA首先利用lncRNA 表达谱、疾病本体论和已知的lncRNA-疾病关联关系,构建lncRNA相似性网络、疾病相似性网络和lncRNA-疾病关联网络。然后,通过设计4个深度自编码器分别从lncRNA/疾病的相似性网络、lncRNA-疾病关联网络学习lncRNA和疾病的低维网络嵌入特征。串联lncRNA和疾病的相似性网络嵌入特征及lncRNA和疾病的关联网络嵌入特征,分别输入两个支持向量机分类器预测lncRNA-疾病关联。最后,采用加权融合策略融合两个支持向量机分类器的预测结果,给出lncRNA-疾病关联关系的最终预测结果。另外,根据已知的lncRNA-疾病关联对和疾病语义相似性,设计一种负样本选取策略构建可信度相对较高的lncRNA-疾病非关联对样本集,用以改善分类器的鲁棒性,该策略通过设计一种打分函数为每对lncRNA-疾病进行打分,选取得分较低的lncRNA-疾病对作为lncRNA-疾病非关联对样本(即负样本)。结果 十折交叉验证实验结果表明:NELDA能够有效预测lncRNA-疾病关联关系,其AUC达到0.982 7,比现有LDASR和 LDNFSGB方法分别提高了0.062 7和0.020 7。另外,负样本选取策略与决策级加权融合策略能够有效改善NELDA预测性能。胃癌和乳腺癌案例研究中,29/40(72.5%)预测的与胃癌和乳腺癌关联lncRNAs,在近期文献和公共数据库中能够发现相关的支撑证据。结论 这些实验结果表明,NELDA是一种有效的lncRNA-疾病关联关系预测方法,具有挖掘潜在lncRNA-疾病关联关系的能力。 相似文献
114.
为了制备包埋率高、稳定性好的火麻仁油微胶囊,拓展其在食品领域的应用范围,以火麻仁油为芯材、单双脂肪酸甘油酯为乳化剂、酪蛋白酸钠为壁材、固体玉米糖浆为填充剂、柠檬酸钠为缓冲盐、抗坏血酸棕榈酸钠为抗氧化剂,通过喷雾干燥法制备60%载油率的火麻仁油微胶囊,以微胶囊包埋率为响应值,在单因素实验的基础上,以干物浓度、进风温度、出风温度为实验因素,采用Box-Behnken响应面分析法进行优化。随后通过扫描电镜观察火麻仁油微胶囊表面形态结构,以确定包埋效果。并利用油脂氧化分析仪检测火麻仁油微胶囊的氧化稳定性。研究确定微胶囊的最佳工艺条件为:干物浓度42%、进风温度168 ℃、出风温度74 ℃,在此条件下制备得到的火麻仁油微胶囊包埋率可达92.15%。通过扫描电镜观察到火麻仁油微胶囊表面圆滑无裂痕,表明火麻仁油微胶囊包埋效果比较理想。经油脂氧化分析仪测定,与对照组(火麻仁油)相比,试验组(火麻仁油微胶囊)的氧化诱导期时间较长,能够达到30 h以上,说明通过对火麻仁油进行微胶囊包埋可以较大程度地提高油脂的稳定性。研究结果为火麻仁油在食品工业领域的开发和应用提供了理论支持。 相似文献
115.
Meiling Zhou Yumei Yuan Zishu Lin Bin Zhang Wenluo Qin Yongqiang Liu Cong Yang Qi Wang Hong Zhang 《Journal of cellular and molecular medicine》2021,25(8):3816-3828
Ageing population is a tough task worldwide, and the aggravating trend of ageing population in China brings enormous pressure to healthcare system. Chinese acupuncture has shown definite anti-ageing effect as arthralgia relief, movement improvement, energy increase and immunity enhancement; however, the mechanisms underlying are far away from illumination. Increasing literature has highlighted the role of alterations in mitochondrial function as a potential central regulator in ageing biology; mitophagy plays a critical role in mitochondrial quality control. In the present study, we demonstrated that acupoint catgut embedding treatment ameliorated ageing-related alterations in appearance, muscle function and spatial memory in rats, reduced degenerated cells in hippocampus, and maintained relatively normal structures in the hippocampus tissue and neurons. These changes were proved to be associated with the regulation of mitochondrial function and autophagic activity. Furthermore, we investigated part of the molecular mechanisms and demonstrated that the PINK1 other than PINK1–Parkin signalling pathway involved in the effects of acupoint catgut embedding, and the imbalancement between mitochondrial fusion and fission and stimulation of mitochondrial biogenesis may aggravate or compensate for impaired mitochondria. The factors act downstream PINK, and the interaction between them for mitochondrial homeostasis in this process remains to be identified. 相似文献
116.
切开复位内固定治疗高能量胫骨平台骨折 总被引:5,自引:0,他引:5
目的:探讨高能量胫骨平台骨折的治疗方法。方法:回顾性分析我院自1996年1月-2002年12月收治高能量伤所致胫骨平台骨折患者38例.骨折按Schatzker分类:Ⅳ型骨折11例;V型骨折18例;Ⅵ型骨折9例,均采用了切开复位,T型和L型钢板固定治疗。结果:35例获得随访,平均随访4.5月(6—29月)。功能评价采用Mechant评分标准,优良率为80%。结论:手术治疗高能量胫骨平台骨折必须着重于早期正确处理软组织损伤、骨折的解剖复位、坚强的内固定。 相似文献
117.
Studies seeking to determine the effects of gait retraining through biofeedback on peak tibial acceleration (PTA) assume that this biometric trait is a valid measure of impact loading that is reliable both within and between sessions. However, reliability and validity data were lacking for axial and resultant PTAs along the speed range of over-ground endurance running. A wearable system was developed to continuously measure 3D tibial acceleration and to detect PTAs in real-time. Thirteen rearfoot runners ran at 2.55, 3.20 and 5.10 m·s−1 over an instrumented runway in two sessions with re-attachment of the system. Intraclass correlation coefficients (ICCs) were used to determine within-session reliability. Repeatability was evaluated by paired T-tests and ICCs. Concerning validity, axial and resultant PTAs were correlated to the peak vertical impact loading rate (LR) of the ground reaction force. Additionally, speed should affect impact loading magnitude. Hence, magnitudes were compared across speeds by RM-ANOVA. Within a session, ICCs were over 0.90 and reasonable for clinical measurements. Between sessions, the magnitudes remained statistically similar with ICCs ranging from 0.50 to 0.59 for axial PTA and from 0.53 to 0.81 for resultant PTA. Peak accelerations of the lower leg segment correlated to LR with larger coefficients for axial PTA (r range: 0.64–0.84) than for the resultant PTA per speed condition. The magnitude of each impact measure increased with speed. These data suggest that PTAs registered per stand-alone system can be useful during level, over-ground, rearfoot running to evaluate impact loading in the time domain when force platforms are unavailable in studies with repeated measurements. 相似文献
118.
1IntroductionForaphysicssyStem,onemayonlyobtainapieceOfiofo~ionabbotitSd~edPaces.In~cases,oneorat~SeveralvariableSoftheSyStemismeaSUledasthesyStemevolvesinaclodoftime.ExamplesarethemeaSuredtetnperatUle,blabsP~ofahumanthey;concentrationsof~entsinachendcalreaction,componentsofthevelvetyOfthefluidincertaindirectionSandthefluctuationOfthePriceinasacmarket.AllthesemeasureddatapresentasatIme~esxl,xZ,'.,xj,inwhichthesuhiindexpreSentSthetimeSampledregUlarlybyatimenitedr.Thequestionhereishow… 相似文献
119.
Rezvan Karami Seyede Maryam Mesbah Namini Nahid Kamelipour Tavoos Rahmani-Cherati Taha Roodbar Shojaei 《Preparative biochemistry & biotechnology》2016,46(6):559-566
Organophosphorus (OP) compounds are one of the most hazardous chemicals used as insecticides/pesticide in agricultural practices. A large variety of OP compounds are hydrolyzed by organophosphorus hydrolases (OPH; EC 3.1.8.1). Therefore, OPHs are among the most suitable candidates that could be used in designing enzyme-based sensors for detecting OP compounds. In this work, a novel nanobiosensor for the detection of paraoxon was designed and fabricated. More specifically, OPH was covalently embedded onto chitosan and the enzyme–chitosan bioconjugate was then immobilized on negatively charged gold nanoparticles (AuNPs) electrostatically. The enzyme was immobilized on AuNPs without chitosan as well, to compare the two systems in terms of detection limit and enzyme stability under different pH and temperature conditions. Coumarin 1, a competitive inhibitor of the enzyme, was used as a fluorogenic probe. The emission of coumarin 1 was effectively quenched by the immobilized Au-NPs when bound to the developed nanobioconjugates. However, in the presence of paraoxon, coumarin 1 left the nanobioconjugate, leading to enhanced fluorescence intensity. Moreover, compared to the immobilized enzyme without chitosan, the chitosan-immobilized enzyme was found to possess decreased Km value by more than 50%, and increased Vmax and Kcat values by around 15% and 74%, respectively. Higher stability within a wider range of pH (2–12) and temperature (25–90°C) was also achieved. The method worked in the 0 to 1050?nM concentration ranges, and had a detection limit as low as 5?×?10?11 M. 相似文献
120.
A Plastic Embedding Technique for Analyzing Fluorescent Dextran-Amine Labelled Neuronal Profiles 总被引:1,自引:0,他引:1
A plastic embedding technique employing fluorescently labelled dextran-amines is described. After application of tracer to cut nerves and appropriate transport time, animals were fixed in paraformaldehyde. Subsequently their brains were dissected, heads and brains were dehydrated, embedded in methacrylate and sectioned serially on a rotary microtome. Plastic sections allow high resolution of single neuron profiles and complete serial reconstruction of un-distorted sections, including embryos with large amounts of yolk. In conjunction with whole mount analysis and double labelling, this technique can accurately reveal the spatial relationships of nerve components throughout development. 相似文献