全文获取类型
收费全文 | 57850篇 |
免费 | 4593篇 |
国内免费 | 4502篇 |
专业分类
66945篇 |
出版年
2024年 | 142篇 |
2023年 | 789篇 |
2022年 | 1851篇 |
2021年 | 3044篇 |
2020年 | 2080篇 |
2019年 | 2501篇 |
2018年 | 2344篇 |
2017年 | 1805篇 |
2016年 | 2544篇 |
2015年 | 3627篇 |
2014年 | 4380篇 |
2013年 | 4436篇 |
2012年 | 5286篇 |
2011年 | 4762篇 |
2010年 | 2882篇 |
2009年 | 2598篇 |
2008年 | 2937篇 |
2007年 | 2634篇 |
2006年 | 2261篇 |
2005年 | 1886篇 |
2004年 | 1509篇 |
2003年 | 1420篇 |
2002年 | 1072篇 |
2001年 | 909篇 |
2000年 | 889篇 |
1999年 | 810篇 |
1998年 | 499篇 |
1997年 | 454篇 |
1996年 | 477篇 |
1995年 | 422篇 |
1994年 | 413篇 |
1993年 | 325篇 |
1992年 | 446篇 |
1991年 | 324篇 |
1990年 | 284篇 |
1989年 | 260篇 |
1988年 | 210篇 |
1987年 | 194篇 |
1986年 | 176篇 |
1985年 | 154篇 |
1984年 | 115篇 |
1983年 | 122篇 |
1982年 | 81篇 |
1981年 | 45篇 |
1980年 | 51篇 |
1979年 | 63篇 |
1976年 | 46篇 |
1974年 | 54篇 |
1973年 | 45篇 |
1972年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
Lisha Shen Guangbin Luo Yanhong Song Shuyi Song Yiwen Li Wenlong Yang Xin Li Jiazhu Sun Dongcheng Liu Aimin Zhang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(12):2745-2763
Key message
A comprehensive comparison of LMW-GS genes between Ae. tauschii and its progeny common wheat.Abstract
Low molecular weight glutenin subunits (LMW-GSs) are determinant of wheat flour processing quality. However, the LMW-GS gene composition in Aegilops tauschii, the wheat D genome progenitor, has not been comprehensively elucidated and the impact of allohexaploidization on the Glu-D3 locus remains elusive. In this work, using the LMW-GS gene molecular marker system and the full-length gene-cloning method, LMW-GS genes at the Glu-D3 loci of 218 Ae. tauschii and 173 common wheat (Triticum aestivum L.) were characterized. Each Ae. tauschii contained 11 LMW-GS genes, and the whole collection was divided into 25 haplotypes (AeH01–AeH25). The Glu-D3 locus in common wheat lacked the LMW-GS genes D3-417, D3-507 and D3-552, but shared eight genes of identical open reading frame (ORF) sequences when compared to that of Ae. tauschii. Therefore, the allohexaploidization induces deletions, but exerts no influence on LMW-GS gene coding sequences at the Glu-D3 locus. 92.17% Ae. tauschii had 7-9 LMW-GSs, more than the six subunits in common wheat. The haplotypes AeH16, AeH20 and AeH23 of Ae. tauschii ssp. strangulate distributed in southeastern Caspian Iran were the main putative D genome donor of common wheat. These results facilitate the utilization of the Ae. tauschii glutenin gene resources and the understanding of wheat evolution.973.
Trpm8 (melastatin-related transient receptor potential member 8), a member of the transient receptor potential (TRP) superfamily,
encoding a cation channel named TRPM8, has been shown to be a primary androgen-responsive gene and play an important role
in prostate physiology. To investigate the expression feature of TRPM8 in urogenital tract of male rats, and whether TRPM8
was also regulated by androgen receptor in these organs, male Sprague–Dawley rats were divided into three groups of 35 animals
as follows: sham-operated (SHAM), orchidectomized (ORX), orchidectomized plus DHT treatment (O + D). Organs in urogenital
tract, including kidney, prostate, seminal vesicle (SV), testis, epididymis and penis, were collected at different post-castration
periods. RT-PCR, real-time PCR and Western blotting were used to detect the expression of androgen receptor (AR) and trpm8
in these tissue. As a result, AR and trpm8 can be detected in all these organs at mRNA or/and protein level. The mRNA expression
of trpm8 in kidney, prostate, SV and penis decreased 24 or 72 h after castration and kept decreasing in a time-dependant manner.
However, treatment of dihydrotestosterone (DHT) could reverse the effect of surgical castration. Collectively, our data provide
evidence that TRPM8 and AR were expressed generally in urogenital tract of male rats, and in these organs, expression of trpm8
was regulated by serum androgen. 相似文献
974.
Wang B Zhang S Cui S Yang B Zhao Y Chen H Hao X Shen Q Zhou J 《Biotechnology letters》2012,34(1):19-28
Two new types of stable ternary complexes were formed by mixing chitosan with DOTAP/pDNA lipoplex and DOTAP with chitosan/pDNA
polyplex via non-covalent conjugation for the efficient delivery of plasmid DNA. They were characterized by atomic force microscopy,
gel retarding, and dynamic light scattering. The DOTAP/CTS/pDNA complexes were in compacted spheroids and irregular lump of
larger aggregates in structure, while the short rod- and toroid-like and donut shapes were found in CTS/DOTAP/pDNA complexes.
The transfection efficiency of the lipopolyplexes showed higher GFP gene expression than DOTAP/pDNA and CTS/pDNA controls
in Hep-2 and Hela cells, and luciferase gene expression 2–3-fold than DOTAP/pDNA control and 70–120-fold than CTS/pDNA control
in Hep-2 cells. The intracellular trafficking was examined by confocal laser scanning microscopy. Rapid pDNA delivery to the
nucleus enchanced by chitosan was achieved after 4 h transfection. 相似文献
975.
976.
Zhe Liu Kun Cao Zebin Liao Yuanyuan Chen Xiao Lei Qun Wei Cong Liu Xuejun Sun Yanyong Yang Jianming Cai Fu Gao 《Journal of cellular and molecular medicine》2020,24(7):3917-3930
Radiation protection on male testis is an important task for ionizing radiation-related workers or people who receive radiotherapy for tumours near the testicle. In recent years, Toll-like receptors (TLRs), especially TLR4, have been widely studied as a radiation protection target. In this study, we detected that a low-toxicity TLR4 agonist monophosphoryl lipid A (MPLA) produced obvious radiation protection effects on mice testis. We found that MPLA effectively alleviated testis structure damage and cell apoptosis induced by ionizing radiation (IR). However, as the expression abundance differs a lot in distinct cells and tissues, MPLA seemed not to directly activate TLR4 singling pathway in mice testis. Here, we demonstrated a brand new mechanism for MPLA producing radiation protection effects on testis. We observed a significant activation of TLR4 pathway in macrophages after MPLA stimulation and identified significant changes in macrophage-derived exosomes protein expression. We proved that after MPLA treatment, macrophage-derived exosomes played an important role in testis radiation protection, and specially, G-CSF and MIP-2 in exosomes are the core molecules in this protection effect. 相似文献
977.
Qingxia Fang Ting Liu Chenhuan Yu Xiuli Yang Yanfei Shao Jiana Shi Xiaolan Ye Xiaochun Zheng Jieping Yan Danfeng Xu Xiaozhou Zou 《Journal of cellular and molecular medicine》2020,24(6):3678-3691
The current study was designed to explore the role and underlying mechanism of lncRNA taurine up-regulated gene 1 (TUG1) in cardiac hypertrophy. Mice were treated by transverse aortic constriction (TAC) surgery to induce cardiac hypertrophy, and cardiomyocytes were treated by phenylephrine (PE) to induce hypertrophic phenotype. Haematoxylin-eosin (HE), wheat germ agglutinin (WGA) and immunofluorescence (IF) were used to examine morphological alterations. Real-time PCR, Western blots and IF staining were used to detect the expression of RNAs and proteins. Luciferase assay and RNA pull-down assay were used to verify the interaction. It is revealed that TUG1 was up-regulated in the hearts of mice treated by TAC surgery and in PE-induced cardiomyocytes. Functionally, overexpression of TUG1 alleviated cardiac hypertrophy both in vivo and in vitro. Mechanically, TUG1 sponged and sequestered miR-34a to increase the Dickkopf 1 (DKK1) level, which eventually inhibited the activation of Wnt/β-catenin signalling. In conclusion, the current study reported the protective role and regulatory mechanism of TUG1 in cardiac hypertrophy and suggested that TUG1 may serve as a novel molecular target for treating cardiac hypertrophy. 相似文献
978.
979.
Honghong Yang Yuanyuan Zhang Zhihai Wang Shixun Zhong Guohua Hu Wenqi Zuo 《Bioelectromagnetics》2020,41(3):219-229
To investigate the possible mechanisms for biological effects of 1,800 MHz mobile radiofrequency radiation (RFR), the radiation-specific absorption rate was applied at 2 and 4 W/kg, and the exposure mode was 5 min on and 10 min off (conversation mode). Exposure time was 24 h short-term exposure. Following exposure, to detect cell DNA damage, cell apoptosis, and reactive oxygen species (ROS) generation, the Comet assay test, flow cytometry, DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) staining, and a fluorescent probe were used, respectively. Our experiments revealed that mobile phone RFR did not cause DNA damage in marginal cells, and the rate of cell apoptosis did not increase (P > 0.05). However, the production of ROS in the 4 W/kg exposure group was greater than that in the control group (P < 0.05). In conclusion, these results suggest that mobile phone energy was insufficient to cause cell DNA damage and cell apoptosis following short-term exposure, but the cumulative effect of mobile phone radiation still requires further confirmation. Activation of the ROS system plays a significant role in the biological effects of RFR. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. 相似文献
980.