全文获取类型
收费全文 | 2215篇 |
免费 | 104篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 33篇 |
2020年 | 24篇 |
2019年 | 24篇 |
2018年 | 35篇 |
2017年 | 31篇 |
2016年 | 39篇 |
2015年 | 78篇 |
2014年 | 96篇 |
2013年 | 135篇 |
2012年 | 144篇 |
2011年 | 150篇 |
2010年 | 96篇 |
2009年 | 114篇 |
2008年 | 158篇 |
2007年 | 151篇 |
2006年 | 163篇 |
2005年 | 137篇 |
2004年 | 137篇 |
2003年 | 142篇 |
2002年 | 141篇 |
2001年 | 20篇 |
2000年 | 23篇 |
1999年 | 13篇 |
1998年 | 15篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 18篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有2319条查询结果,搜索用时 46 毫秒
991.
Cynthia Sung Yuan Wei Satoru Watanabe How Sung Lee Yok Moi Khoo Lu Fan Abhay P. S. Rathore Kitti Wing-Ki Chan Milly M. Choy Uma S. Kamaraj October M. Sessions Pauline Aw Paola F. de Sessions Bernett Lee John E. Connolly Martin L. Hibberd Dhanasekaran Vijaykrishna Limin Wijaya Eng Eong Ooi Jenny Guek-Hong Low Subhash G. Vasudevan 《PLoS neglected tropical diseases》2016,10(8)
992.
Yusuke Urushihara Koh Kawasumi Satoru Endo Kenichi Tanaka Yasuko Hirakawa Gohei Hayashi Tsutomu Sekine Yasushi Kino Yoshikazu Kuwahara Masatoshi Suzuki Motoi Fukumoto Hideaki Yamashiro Yasuyuki Abe Tomokazu Fukuda Hisashi Shinoda Emiko Isogai Toshiro Arai Manabu Fukumoto 《PloS one》2016,11(5)
The effect of the Fukushima Daiichi Nuclear Power Plant (FNPP) accident on humans and the environment is a global concern. We performed biochemical analyses of plasma from 49 Japanese Black cattle that were euthanized in the ex-evacuation zone set within a 20-km radius of FNPP. Among radionuclides attributable to the FNPP accident, germanium gamma-ray spectrometry detected photopeaks only from 134Cs and 137Cs (radiocesium) commonly in the organs and in soil examined. Radioactivity concentration of radiocesium was the highest in skeletal muscles. Assuming that the animal body was composed of only skeletal muscles, the median of internal dose rate from radiocesium was 12.5 μGy/day (ranging from 1.6 to 33.9 μGy/day). The median of external dose rate calculating from the place the cattle were caught was 18.8 μGy/day (6.0–133.4 μGy/day). The median of internal and external (total) dose rate of the individual cattle was 26.9 μGy/day (9.1–155.1 μGy/day). Plasma levels of malondialdehyde and superoxide dismutase activity were positively and glutathione peroxidase activity was negatively correlated with internal dose rate. Plasma alanine transaminase activity and percent activity of lactate dehydrogenase (LDH)-2, LDH-3 and LDH-4 were positively and LDH-1 was negatively correlated with both internal and total dose rate. These suggest that chronic exposure to low-dose rate of ionizing radiation induces slight stress resulting in modified plasma protein and enzyme levels. 相似文献
993.
994.
Hyperspectral imaging techniques for the characterization of Haematococcus pluvialis (Chlorophyceae)
A hyperspectral imaging camera was combined with a bright‐field microscope to investigate the intracellular distribution of pigments in cells of the green microalga Haematococcus pluvialis, a synonym for H. lacustris (Chlorophyceae). We applied multivariate curve resolution to the hyperspectral image data to estimate the pigment contents in culture and revealed that the predicted values were consistent with actual measurements obtained from extracted pigments. Because it was possible to estimate pigment contents in every pixel, the intracellular distribution of the pigments was investigated during various life‐cycle stages. Astaxanthin was localized specifically at the eyespot of zoospores in early culture stages. Then, it became widely distributed in cells, but subsequently localized differently than the chl. Integrated with our recently developed image‐processing program “HaematoCalMorph,” the hyperspectral imaging system was useful for monitoring intracellular distributions of pigments during culture as well as for studying cellular responses under various conditions. 相似文献
995.
Kyoko Shinzawa-Itoh Harunobu Shimomura Sachiko Yanagisawa Satoru Shimada Ryoko Takahashi Marika Oosaki Takashi Ogura Tomitake Tsukihara 《The Journal of biological chemistry》2016,291(8):4178-4184
To understand the roles of mitochondrial respiratory chain supercomplexes, methods for consistently separating and preparing supercomplexes must be established. To this end, we solubilized supercomplexes from bovine heart mitochondria with digitonin and then replaced digitonin with amphipol (A8–35), an amphiphilic polymer. Afterward, supercomplexes were separated from other complexes by sucrose density gradient centrifugation. Twenty-six grams of bovine myocardium yielded 3.2 mg of amphipol-stabilized supercomplex. The purified supercomplexes were analyzed based on their absorption spectra as well as Q10 (ubiquinone with ten isoprene units) and lipid assays. The supercomplex sample did not contain cytochrome c but did contain complexes I, III, and IV at a ratio of 1:2:1, 6 molecules of Q10, and 623 atoms of phosphorus. When cytochrome c was added, the supercomplex exhibited KCN-sensitive NADH oxidation; thus, the purified supercomplex was active. Reduced complex IV absorbs at 444 nm, so we measured the resonance Raman spectrum of the reduced amphipol-solubilized supercomplex and the mixture of amphipol-solubilized complexes I1, III2, and IV1 using an excitation wavelength of 441.6 nm, allowing measurement precision comparable with that obtained for complex IV alone. Use of the purified active sample provides insights into the effects of supercomplex formation. 相似文献
996.
Minoru Kubo Satoru Nakashima Satoru Yamaguchi Takashi Ogura Masao Mochizuki Jiyoung Kang Masaru Tateno Kyoko Shinzawa-Itoh Koji Kato Shinya Yoshikawa 《The Journal of biological chemistry》2013,288(42):30259-30269
X-ray structural and mutational analyses have shown that bovine heart cytochrome c oxidase (CcO) pumps protons electrostatically through a hydrogen bond network using net positive charges created upon oxidation of a heme iron (located near the hydrogen bond network) for O2 reduction. Pumping protons are transferred by mobile water molecules from the negative side of the mitochondrial inner membrane through a water channel into the hydrogen bond network. For blockage of spontaneous proton back-leak, the water channel is closed upon O2 binding to the second heme (heme a3) after complete collection of the pumping protons in the hydrogen bond network. For elucidation of the structural bases for the mechanism of the proton collection and timely closure of the water channel, conformational dynamics after photolysis of CO (an O2 analog)-bound CcO was examined using a newly developed time-resolved infrared system feasible for accurate detection of a single C=O stretch band of α-helices of CcO in H2O medium. The present results indicate that migration of CO from heme a3 to CuB in the O2 reduction site induces an intermediate state in which a bulge conformation at Ser-382 in a transmembrane helix is eliminated to open the water channel. The structural changes suggest that, using a conformational relay system, including CuB, O2, heme a3, and two helix turns extending to Ser-382, CuB induces the conformational changes of the water channel that stimulate the proton collection, and senses complete proton loading into the hydrogen bond network to trigger the timely channel closure by O2 transfer from CuB to heme a3. 相似文献
997.
Yoji Nakamura Naobumi Sasaki Masahiro Kobayashi Nobuhiko Ojima Motoshige Yasuike Yuya Shigenobu Masataka Satomi Yoshiya Fukuma Koji Shiwaku Atsumi Tsujimoto Takanori Kobayashi Ichiro Nakayama Fuminari Ito Kazuhiro Nakajima Motohiko Sano Tokio Wada Satoru Kuhara Kiyoshi Inouye Takashi Gojobori Kazuho Ikeo 《PloS one》2013,8(3)
Nori, a marine red alga, is one of the most profitable mariculture crops in the world. However, the biological properties of this macroalga are poorly understood at the molecular level. In this study, we determined the draft genome sequence of susabi-nori (Pyropia yezoensis) using next-generation sequencing platforms. For sequencing, thalli of P. yezoensis were washed to remove bacteria attached on the cell surface and enzymatically prepared as purified protoplasts. The assembled contig size of the P. yezoensis nuclear genome was approximately 43 megabases (Mb), which is an order of magnitude smaller than the previously estimated genome size. A total of 10,327 gene models were predicted and about 60% of the genes validated lack introns and the other genes have shorter introns compared to large-genome algae, which is consistent with the compact size of the P. yezoensis genome. A sequence homology search showed that 3,611 genes (35%) are functionally unknown and only 2,069 gene groups are in common with those of the unicellular red alga, Cyanidioschyzon merolae. As color trait determinants of red algae, light-harvesting genes involved in the phycobilisome were predicted from the P. yezoensis nuclear genome. In particular, we found a second homolog of phycobilisome-degradation gene, which is usually chloroplast-encoded, possibly providing a novel target for color fading of susabi-nori in aquaculture. These findings shed light on unexplained features of macroalgal genes and genomes, and suggest that the genome of P. yezoensis is a promising model genome of marine red algae. 相似文献
998.
Satoru Tamura Sho Inomata Makoto Ebine Takahisa Genji Izumi Iwakura Makoto Mukai Mitsuru Shoji Takeshi Sugai Minoru Ueda 《Bioorganic & medicinal chemistry letters》2013,23(1):188-193
In methods employing molecular probes to explore the targets of bioactive small molecules, long or rigid linker moieties are thought to be critical factors for efficient tagging of target protein. We previously reported the synthesis of a jasmonate glucoside probe with a highly rigid linker consisting of a triazoyl–phenyl (TAzP) moiety, and this probe demonstrated effective target tagging. Here we compare the TAzP probe with other rigid or flexible probes with respect to target tagging efficiency, hydrophobic parameters, aqueous solubility, and dihedral angles around the biaryl linkage by a combination of empirical and calculation methods. The rigid biaryl linkage of the TAzP probe has a skewed conformation that influences its aqueous solubility. Such features that include rigidness and good aqueous solubility resulted in highly efficient target tagging. These findings provide a promising guideline toward designing of better linkers for improving molecular probe performance. 相似文献
999.
Yoshishige Okazawa Mitsuo Namiki Satoru Yamashita Akira Matsuyama 《Bioscience, biotechnology, and biochemistry》2013,77(3):235-242
Aiming at the enhancement of total lethal effect of radiations, chemical agent actions on irradiated cells were investigated. It was found that the sensitivity of irradiated cells to NaCl was markedly increased by radiation. In other words, the over-all lethal effect of radiations on microorganisms was enhanced by the pre- or post-treatment with NaCl. Some microbiological aspects of radiation enhancement of NaCl sensitivity were described in this paper, connecting with the possible mechanism. The fact that this phenomenon of radiation enhancement was observed in the case of the cells which gave the one-hit type survival curve suggests that radiation damage responsible for this phenomenon is not restricted to biological targets. Further discussion and experimental evidences will be presented in the subsequent paper. 相似文献
1000.
A dielectric relaxation peak due to bound water of globule proteins in aqueous solution was observed at first by the use of a time domain reflectometry. This peak locates around 100 MHz as well as that of the aqueous DNA solution and the moist collagen, and has a relaxation strength in proportion to surface of the globule protein except for trypsin and pepsin of hydrolase. It is suggested that this peak is caused by orientation of bound water molecules on the protein surface. The number of bound water molecules estimated is in good agreement with that obtained by other method such as x-ray analysis. The solution exhibits another peak below 100 MHz, which is caused by the rotation of globule protein supplemented by migration of the counterion. Its relaxation time is completely proportional to the molecular weight of the protein. © 1994 John Wiley & Sons, Inc. 相似文献