全文获取类型
收费全文 | 1914篇 |
免费 | 116篇 |
国内免费 | 1篇 |
出版年
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 17篇 |
2018年 | 15篇 |
2017年 | 21篇 |
2016年 | 21篇 |
2015年 | 40篇 |
2014年 | 45篇 |
2013年 | 113篇 |
2012年 | 102篇 |
2011年 | 108篇 |
2010年 | 52篇 |
2009年 | 57篇 |
2008年 | 94篇 |
2007年 | 91篇 |
2006年 | 89篇 |
2005年 | 91篇 |
2004年 | 74篇 |
2003年 | 103篇 |
2002年 | 76篇 |
2001年 | 80篇 |
2000年 | 83篇 |
1999年 | 71篇 |
1998年 | 25篇 |
1997年 | 20篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 6篇 |
1992年 | 47篇 |
1991年 | 32篇 |
1990年 | 37篇 |
1989年 | 40篇 |
1988年 | 30篇 |
1987年 | 36篇 |
1986年 | 39篇 |
1985年 | 29篇 |
1984年 | 25篇 |
1983年 | 18篇 |
1982年 | 18篇 |
1981年 | 10篇 |
1979年 | 14篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1970年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有2031条查询结果,搜索用时 31 毫秒
121.
Eight chloroplast markers were developed from Japanese and snow camellia (Camellia japonica and C. rusticana). Six markers were based on mononucleotide repeats, while the other two resulted from indels of larger units. Polymorphisms were screened using 15 individuals from all over the Japanese archipelago, including C. japonica, C. japonica var. macrocarpa, C. japonica var. hozanensis, and C. rusticana. Polymorphisms within a single population were searched in 22 and 26 individuals of C. japonica and C. rusticana, respectively. The number of alleles per locus ranged from two to three, resulting in eight haplotypes, two of which were specific to C. rusticana. No polymorphisms were detected within a single population for both C. japonica and C. rusticana. The eight markers developed in the present study will be useful for analyzing the genetic diversity and tracing maternal origins of Japanese and snow camellias. 相似文献
122.
Akash Chandela Taeko Watanabe Kenji Yamagishi Yoshihito Ueno 《Bioorganic & medicinal chemistry》2019,27(7):1341-1349
With the aim to create a small interfering RNA (siRNA) with enhanced activity and resistance to nuclease degradation, we synthesized and evaluated the properties of the following siRNAs containing haloalkyl β-d-ribofuranosides at their 3′-dangling ends: 2,2,2-trifluoroethyl β-d-ribofuranoside, 2,2,2-trichloroethyl β-d-ribofuranoside and 2,2,2-tribromoethyl β-d-ribofuranoside. The gene silencing activities of the modified siRNAs were investigated through a dual luciferase reporter assay using HeLa cells. The highest silencing activity was observed for the trichloroethyl analog modified siRNA, which was closely followed by the trifluoroethyl and tribromoethyl analogs. The modified siRNAs were found to show increased binding affinity towards the Piwi-Argonaute-Zwille (PAZ) domain protein based on computational analysis and an experimental study. Furthermore, the RNAs modified with the analogs at their 3′-ends exhibited improved resistance to hydrolysis by a 3′-exonuclease. 相似文献
123.
Fukasawa A Nagashima T Aoyama T Fukuda N Matsuda H Ueno T Sugiyama H Nagase H Matsumoto Y 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,859(2):272-275
A simple and sensitive high-performance liquid chromatography (HPLC) method utilizing UV detection was developed for the determination of plasma pyrrole (Py)-imidazole (Im) polyamides in rats and applied to the pharmacokinetic study of compounds. After deproteinization of plasma with methanol, Py-Im polyamides were analyzed with a reversed-phase TSK-GEL ODS-80TM (4.6 mmx15.0 cm TOSOH Co., Japan) column maintained at 40 degrees C. The mobile phase solvent A was 0.1% acetic acid and the solvent B was HPLC-grade acetonitrile (0-10 min, A: 100-20%, B: 0-80% linear gradient; 10-15 min, A: 40%, B: 60%). The flow rate was 1.0 ml/min. The detection wavelength was set at 310 nm. The method was used to determine the plasma concentration time profiles of Py-Im polyamides after intravenous injection. 相似文献
124.
Hiroyuki Nakamura Jong-Dae Lee Manabu Ueno Yusuke Miyajima Hyun Seung Ban 《NanoBioTechnology》2007,3(2):135-145
High accumulation and selective delivery of boron into tumor tissues are the most important requirements to achieve efficient
neutron capture therapy of cancers. We focused on liposomal boron delivery system to achieve a large amount of boron delivery
to tumor. We succeeded in the synthesis of the double-tailed boron cluster lipids 4a–c and 5a–c, which has a B12H11S-moiety as a hydrophilic function, by S-alkylation of B12H11SH with bromoacetyl and chloroacetocarbamate derivatives of diacylglycerols. Size distribution of liposomes prepared from
the boron cluster lipid 4b, dimyristoylphosphatidylcholine, polyethyleneglycol-conjugated distearoylphosphatidylethanolamine, and cholesterol was determined
as 100 nm in diameter by an electrophoretic light scattering spectrophotometer. Calcein-encapsulation experiments revealed
that these boronated liposomes are stable at 37 °C in fetal bovine serum solution for 24 h. 相似文献
125.
Akari Nitta Kazuya Hori Isei Tanida Ayumi Igarashi Yasuyo Deyama Takashi Ueno Eiki Kominami Manabu Sugai Koji Aoki 《Biochemical and biophysical research communications》2019,508(2):521-526
Autophagy, a system for the bulk degradation of intracellular components, is essential for homeostasis and the healthy physiology and development of cells and tissues. Its deregulation is associated with human disease. Thus, methods to modulate autophagic activity are critical for analysis of its role in mammalian cells and tissues. Here we report a method to inhibit autophagy using a mutant variant of the protein ATG7, a ubiquitin E1-like enzyme essential for autophagosome formation. During autophagy, ATG7 activates the conjugation of LC3 (ATG8) with phosphatidylethanolamine (PE) and ATG12 with ATG5. Human ATG7 interactions with LC3 or ATG12 require a thioester bond involving the ATG7 cysteine residue at position 572. We generated TetOff cells expressing mutant ATG7 protein carrying a serine substitution of this critical cysteine residue (ATG7C572S). Because ATG7C572S forms stable intermediate complexes with LC3 or ATG12, its expression resulted in a strong blockage of the ATG-conjugation system and suppression of autophagosome formation. Consequently, ATG7C572S mutant protein can be used as an inhibitor of autophagy. 相似文献
126.
Nagao Ryo Ueno Yoshifumi Akita Fusamichi Suzuki Takehiro Dohmae Naoshi Akimoto Seiji Shen Jian-Ren 《Photosynthesis research》2019,140(2):141-149
Photosynthesis Research - Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom... 相似文献
127.
Sakamoto Kazunori Ogiwara Natsuko Kaji Tomomitsu Sugimoto Yurie Ueno Mitsuru Sonoda Masatoshi Matsui Akihiro Ishida Junko Tanaka Maho Totoki Yasushi Shinozaki Kazuo Seki Motoaki 《Journal of plant research》2019,132(4):541-568
Journal of Plant Research - Soybean (Glycine max) roots establish associations with nodule-inducing rhizobia and arbuscular mycorrhizal (AM) fungi. Both rhizobia and AM fungi have been shown to... 相似文献
128.
The ATP hydrolysis mechanism of myosin was studied using quantum chemical (QM) and molecular dynamics calculations. The initial model compound for QM calculations was constructed on the basis of the energy-minimized structure of the myosin(S1dc)-ATP complex, which was determined by molecular mechanics calculations. The result of QM calculations suggested that the ATP hydrolysis mechanism of myosin consists of a single elementary reaction in which a water molecule nucleophilically attacked gamma-phosphorus of ATP. In addition, we performed molecular dynamics simulations of the initial and final states of the ATP hydrolysis reaction, that is, the myosin-ATP and myosin-ADP.Pi complexes. These calculations revealed roles of several amino acid residues (Lys185, Thr186, Ser237, Arg238, and Glu459) in the ATPase pocket. Lys185 maintains the conformation of beta- and gamma-phosphate groups of ATP by forming the hydrogen bonds. Thr186 and Ser237 are coordinated to a Mg(2+) ion, which interacts with the phosphates of ATP and therefore contributes to the stabilization of the ATP structure. Arg238 and Glu459, which consisted of the gate of the ATPase pocket, retain the water molecule acting on the hydrolysis at the appropriate position for initiating the hydrolysis. 相似文献
129.
130.
Tanida I Tanida-Miyake E Ueno T Kominami E 《The Journal of biological chemistry》2001,276(3):1701-1706
Autophagy is a process that involves the bulk degradation of cytoplasmic components by the lysosomal/vacuolar system. In the yeast, Saccharomyces cerevisiae, an autophagosome is formed in the cytosol. The outer membrane of the autophagosome is fused with the vacuole, releasing the inner membrane structure, an autophagic body, into the vacuole. The autophagic body is subsequently degraded by vacuolar hydrolases. Taking advantage of yeast genetics, apg (autophagy-defective) mutants were isolated that are defective in terms of formation of autophagic bodies under nutrient starvation conditions. One of the APG gene products, Apg12p, is covalently attached to Apg5p via the C-terminal Gly of Apg12p as in the case of ubiquitylation, and this conjugation is essential for autophagy. Apg7p is a novel E1 enzyme essential for the Apg12p-conjugation system. In mammalian cells, the human Apg12p homolog (hApg12p) also conjugates with the human Apg5p homolog. In this study, the unique characteristics of hApg7p are shown. A two-hybrid experiment indicated that hApg12p interacts with hApg7p. Site-directed mutagenesis revealed that Cys(572) of hApg7p is an authentic active site cysteine residue essential for the formation of the hApg7p.hApg12p intermediate. Overexpression of hApg7p enhances the formation of the hApg5p.hApg12p conjugate, indicating that hApg7p is an E1-like enzyme essential for the hApg12p conjugation system. Cross-linking experiments and glycerol-gradient centrifugation analysis showed that the mammalian Apg7p homolog forms a homodimer as in yeast Apg7p. Each of three human Apg8p counterparts, i.e. the Golgi-associated ATPase enhancer of 16 kDa, GABA(A) receptor-associated protein, and microtubule-associated protein light chain 3, coimmunoprecipitates with hApg7p and conjugates with mutant hApg7p(C572S) to form a stable intermediate via an ester bond. These results indicate that hApg7p is an authentic protein-activating enzyme for hApg12p and the three Apg8p homologs. 相似文献