全文获取类型
收费全文 | 6732篇 |
免费 | 555篇 |
国内免费 | 400篇 |
出版年
2024年 | 24篇 |
2023年 | 190篇 |
2022年 | 251篇 |
2021年 | 338篇 |
2020年 | 372篇 |
2019年 | 459篇 |
2018年 | 385篇 |
2017年 | 282篇 |
2016年 | 329篇 |
2015年 | 333篇 |
2014年 | 477篇 |
2013年 | 741篇 |
2012年 | 285篇 |
2011年 | 321篇 |
2010年 | 230篇 |
2009年 | 271篇 |
2008年 | 294篇 |
2007年 | 274篇 |
2006年 | 269篇 |
2005年 | 226篇 |
2004年 | 196篇 |
2003年 | 152篇 |
2002年 | 167篇 |
2001年 | 101篇 |
2000年 | 63篇 |
1999年 | 77篇 |
1998年 | 81篇 |
1997年 | 65篇 |
1996年 | 52篇 |
1995年 | 44篇 |
1994年 | 42篇 |
1993年 | 38篇 |
1992年 | 20篇 |
1991年 | 32篇 |
1990年 | 24篇 |
1989年 | 29篇 |
1988年 | 10篇 |
1987年 | 18篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 27篇 |
1983年 | 14篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1950年 | 1篇 |
排序方式: 共有7687条查询结果,搜索用时 500 毫秒
1.
In this work, incorporation of plasmid DNA, pre-complexed with PEI, into polyelectrolyte multilayers has been studied to further develop platforms for local gene delivery. Polyplex embedding in synthetic and naturally degradable architectures was efficient for transfection of human hepato-cellular carcinoma cells. 相似文献
2.
《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):837-839
Abstract Some diacid biodegradable synthesis of aziduthymidine (AZT) were synthesized and applied to production of about 60 different derivatives. 相似文献
3.
4.
5.
6.
Ulrich Weser Karl-Heinz Sellinger Edmund Lengfelder Walther Werner Joachim Strähle 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,631(2):232-245
The copper complex of indomethacin (1-(p-chlorobenzoyl)-5-methoxy-2-methyl-indole acetate), a common anti-inflammatory drug, was prepared and characterized. Crystal structure determination revealed the dimeric form of the 1:2 complex, namely Cu2(indomethacin)4 · L2, in the unit cell. Suprisingly, the copper-copper distance (263 pm) was very close to metallic copper (256 pm). The two coordination sites in the copper-copper axis can be readily replaced by superoxide. An intriguing similarity to Cu2(acetate)4 was seen.Due to the lipophilic nature of the indomethacin ligand, this copper complex reacted with superoxide in aprotic solvents. The superoxide dismutating activity was successfully demonstrated in Me2SO/water and acetonitrile/water mixtures using the nitro-blue tetrazolium assay and pulse radiolysis. The second-order rate constant of 6 · 109 M?1 · s?1 in strictly aqueous systems dropped only slightly to 1.1 · 109 M?1 · s?1 when aprotic solvents were used. This is the fastest rate constant ever observed for a copper-dependent dismutation of superoxide. The KO2-induced lipid peroxidation in both erythrocytes and liver microsomes was suppressed by 70% in the presence of 1 · 10?10 mol · ml?1 of Cu2(indomethacin)4. The inhibitory action dropped to 25% when Cu2Zn2superoxide dismutase was employed. The formation of copper · indomethacin in rat serum after administration of indomethacin was shown in vitro and in vivo. 相似文献
7.
Mahsa Zahiri Maryam Babaei Khalil Abnous Seyed Mohammad Taghdisi Mohammad Ramezani Mona Alibolandi 《Journal of cellular physiology》2020,235(2):1036-1050
In this study, the chemical features of dendritic mesoporous silica nanoparticles (DMSNs) provided the opportunity to design a nanostructure with the capability to intelligently transport the payload to the tumor cells. In this regard, doxorubicin (DOX)-encapsulated DMSNs was electrostatically surface-coated with polycarboxylic acid dextran (PCAD) to provide biocompatible dextran-capped DMSNs (PCAD-DMSN@DOX) with controlled pH-dependent drug release. Moreover, a RNA aptamer against a cancer stem cell (CSC) marker, CD133 was covalently attached to the carboxyl groups of DEX to produce a CD133-PCAD-DMSN@DOX. Then, the fabricated nanosystem was utilized to efficiently deliver DOX to CD133+ colorectal cancer cells (HT29). The in vitro evaluation in terms of cellular uptake and cytotoxicity demonstrated that the CD133-PCAD-DMSN@DOX specifically targets HT29 as a CD133 overexpressed cancer cells confirmed by flow cytometry and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. The potentially promising intelligent-targeted platform suggests that targeted dextran-capped DMSNs may find impressive application in cancer therapy. 相似文献
8.
9.
Reactive oxygen species (ROS) are involved in the pathophysiology of fulminant hepatic failure. Therefore, we developed polyethylene glycol-conjugated bovine serum albumin with multiple reduced thiols (PEG-BSA-SH) for the treatment of fulminant hepatic failure. As a long-circulating ROS scavenger, PEG-BSA-SH effectively scavenged highly reactive oxygen species and hydrogen peroxide in buffer solution. PEG-BSA-SH showed a long circulation time in the plasma after intravenous injection into mice. Fulminant hepatic failure was induced by intraperitoneal injection of lipopolysaccharide and d-galactosamine (LPS/d-GalN) into mice. The LPS/d-GalN-induced elevation of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels was significantly inhibited by a bolus intravenous injection of PEG-BSA-SH. Furthermore, the changes in hepatic lipid peroxide and hepatic blood flow were effectively suppressed by PEG-BSA-SH. In contrast, l-cysteine, glutathione, and dithiothreitol, three traditional reduced thiols, had no statistically significant effects on the serum levels of ALT or AST. These findings indicate that PEG-BSA-SH is a promising ROS scavenger and useful in the treatment of fulminant hepatic failure. 相似文献
10.
zge Karayel Francesca Tonelli Sebastian Virreira Winter Phillip E. Geyer Ying Fan Esther M. Sammler Dario R. Alessi Martin Steger Matthias Mann 《Molecular & cellular proteomics : MCP》2020,19(9):1546-1560
Highlights
- •MS-based clinical assay that accurately determines phospho Rab10 occupancy.
- •Stable isotope labeled phosphopeptide injected as a standard with endogenous tryptic phospho Rab peptide for accurate ratio determination.
- •Determination of pRab levels in neutrophils of Parkinson disease patients.
- •Relevance of pRab levels as marker of PD.