全文获取类型
收费全文 | 2210篇 |
免费 | 169篇 |
国内免费 | 180篇 |
出版年
2024年 | 5篇 |
2023年 | 27篇 |
2022年 | 43篇 |
2021年 | 94篇 |
2020年 | 87篇 |
2019年 | 95篇 |
2018年 | 68篇 |
2017年 | 65篇 |
2016年 | 89篇 |
2015年 | 132篇 |
2014年 | 155篇 |
2013年 | 176篇 |
2012年 | 210篇 |
2011年 | 181篇 |
2010年 | 133篇 |
2009年 | 112篇 |
2008年 | 145篇 |
2007年 | 88篇 |
2006年 | 82篇 |
2005年 | 78篇 |
2004年 | 63篇 |
2003年 | 48篇 |
2002年 | 51篇 |
2001年 | 36篇 |
2000年 | 38篇 |
1999年 | 41篇 |
1998年 | 18篇 |
1997年 | 12篇 |
1996年 | 14篇 |
1995年 | 22篇 |
1994年 | 18篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 16篇 |
1988年 | 16篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有2559条查询结果,搜索用时 15 毫秒
41.
Katarína Šoltys Matej Planý Paola Biocca Valentina Vianello Mária Bučková Andrea Puškárová Maria Carla Sclocchi Piero Colaizzi Marina Bicchieri Domenico Pangallo Flavia Pinzari 《Environmental microbiology》2020,22(4):1517-1534
A multidisciplinary approach was carried out in order to study the biodeterioration and the associated microbiome of a XVIII Century wax seal coloured with minium. A small wax seal fragment was observed by scanning electron microscopy combined with energy dispersive spectroscopy in non-destructive mode. The same object was analysed by Raman and Fourier-transform infrared spectroscopy. The identification of the microbiota growing on the seal was performed with both a culture-dependent strategy, combined with hydrolytic assays, and high-throughput sequencing using the MinION platform. The whole bacterial 16S rRNA gene and the fungal markers ITS and 28S rRNA were targeted. It was observed that the carnauba wax coloured with lead tetroxide (minium) was covered by a biofilm consisting of a network of filaments and other structures of microbial origin. The culture-dependent and culture-independent investigations showed the presence of a complex microbiota composed mainly by fungal members, which demonstrated interesting properties related to lipids and lead processing. The formation of lead soaps and secondary biogenic minerals was also described. 相似文献
42.
43.
Luming Zhuang Fei Peng Yuanyuan Huang Wenzhe Li Jiuhong Huang Yunqiang Chu Pu Ren Ying Sun Yan Zhang Elleen Xue Xiaowei Guo Xiafeng Shen Lei Xue 《Aging cell》2020,19(2)
Dysregulation of autophagy is associated with the neurodegenerative processes in Alzheimer's disease (AD), yet it remains controversial whether autophagy is a cause or consequence of AD. We have previously expressed the full‐length human APP in Drosophila and established a fly AD model that exhibits multiple AD‐like symptoms. Here we report that depletion of CHIP effectively palliated APP‐induced pathological symptoms, including morphological, behavioral, and cognitive defects. Mechanistically, CHIP is required for APP‐induced autophagy dysfunction, which promotes Aβ production via increased expression of BACE and Psn. Our findings suggest that aberrant autophagy is not only a consequence of abnormal APP activity, but also contributes to dysregulated APP metabolism and subsequent AD pathogenesis. 相似文献
44.
45.
46.
Wei Chen Daofeng Zheng Tong Mou Junliang Pu Jiangwen Dai Zuotian Huang 《Bioscience, biotechnology, and biochemistry》2020,84(6):1176-1182
ABSTRACTLiver damage induced by ischemia/reperfusion (I/R) remains a primary issue in multiple hepatic surgeries. Innate immune-mediated inflammatory responses during the reperfusion stage aggravate the injury. Nevertheless, the detailed mechanism of hepatic I/R has not been fully clarified yet. Our research focuses on the role of Transducin-like enhancer of split-1 (Tle1) in the liver I/R injury and the relation between Tle1 and Nucleotide-binding oligomerization domain 2 (NOD2). To answer these questions, we constructed mouse models of I/R and cell models of hypoxia/reoxygenation (H/R). We found decreased Tle1 accompanied by increased NOD2 during reperfusion. Mice pro-injected with Tle1-siRNA emerged aggravated liver dysfunction. Repression of Tle1 had a significant impact on NOD2 and downstream NF-κB signaling in vitro. However, alteration of NOD2 failed to affect the expression of Tle1. To conclude, our study demonstrates that Tle1 shelters the liver from I/R injury through suppression of NOD2-dependent NF-κB activation and subsequent inflammatory responses. 相似文献
47.
48.
Kuang Cheng-Hao Zhao Xiao-Fang Yang Ke Zhang Zhi-Peng Ding Li Pu Zhi-En Ma Jian Jiang Qian-Tao Chen Guo-Yue Wang Ji-Rui Wei Yu-Ming Zheng You-Liang Li Wei 《Physiology and Molecular Biology of Plants》2020,26(6):1295-1307
Physiology and Molecular Biology of Plants - The spike traits of wheat can directly affect yield. F2 and F2:3 lines derived from the cross of the multi-spikelet female 10-A and the uni-spikelet... 相似文献
49.
抗原纯净度是口蹄疫 (Foot-and-mouth disease,FMD) 灭活疫苗质量检验的一项重要内容,一般采用疫苗2–3次免疫动物后,检测非结构蛋白 (Non-structural protein,NSP) 抗体是否阳转,判断疫苗抗原的纯净度。文中旨在建立定量检测FMD灭活疫苗抗原中NSP 3AB含量的ELISA方法,为疫苗质量控制提供参考方法。利用口蹄疫病毒 (Foot-and-mouth disease virus,FMDV) NSP 3A单克隆抗体和辣根过氧化物酶 (Horseradish peroxidase,HRP) 标记的3B单克隆抗体,建立定量检测NSP 3AB含量的双抗体夹心ELISA检测方法。采用原核表达并纯化的3AB蛋白作为标准品,标准品系列稀释,绘制标准曲线,以标准品与未加抗原的阴性对照吸光值 (OD) 的比值大于2.0的标准品最低浓度为最低检测限。标准品浓度介于4.7–600.0 ng/mL之间时,测得的OD值与浓度呈线性相关,回归曲线呈直线,相关系数R2=0.99,确定最低检测限为4.7 ng/mL。检测12份未纯化灭活抗原中3AB蛋白含量介于9.3–200.0 ng/mL之间;而纯化后的病毒抗原中3AB蛋白残留量低于最低检测限;33份来自不同厂家的成品疫苗抗原中9份疫苗抗原3AB蛋白含量在9.0–74.0 ng/mL之间,其余24份疫苗抗原中3AB蛋白残留量低于最低检测限。检测3AB蛋白含量的双抗体夹心ELISA方法能够特异、敏感地检测疫苗抗原中的3AB蛋白含量,为疫苗质量控制与纯净度检验提供了一种可供选择的检测方法。 相似文献
50.
不同除草剂的田间杂草防效及对糜子生长发育的影响 总被引:1,自引:0,他引:1
筛选糜子适宜除草剂来防范农田药害,是糜子高效安全生产和改善生态环境亟待解决的关键问题。本研究以粳性糜子品种‘榆糜2号'为材料,探究22种除草剂对糜子田间杂草的防除效果及对糜子生长发育的影响。结果表明: 1)喷施土壤封闭型除草剂谷友、丁草胺、莠去津、苄嘧·丙草胺和茎叶型除草剂苯唑·二甲钠、阔世玛、藤净、陶氏·优先、阔菲后,基本无药害作用,糜子幼苗生长正常,其余除草剂均对糜子有不同程度的药害影响;2)参试的22种除草剂在糜子田中对杂草均表现出一定的防除效果,总体而言,土壤封闭型除草剂的杂草防效相对优于茎叶型除草剂,但所有参试除草剂对糜子株高、功能叶片叶绿素含量、单株穗重均造成不同程度的影响;3)与人工除草相比,参试除草剂均导致糜子产量有不同程度的下降;但与不除草对照相比,部分除草剂有明显的增产增效作用。土壤封闭型除草剂中,谷友、丁草胺、莠去津、苄嘧·丙草胺的杂草防效较好,较不除草对照增产60%以上;茎叶型除草剂中,阔世玛、苯唑·二甲钠的杂草防效较好,较不除草对照增产50%以上。因此,在糜子出苗前可用38%莠去津或44%单嘧磺隆进行土壤封闭处理,或在出苗后喷施茎叶型除草剂3.6%二磺·甲碘隆或55%苯唑·二甲钠,农田杂草防效较好,且对糜子生长发育的负面影响较小。 相似文献