全文获取类型
收费全文 | 1145篇 |
免费 | 46篇 |
出版年
2023年 | 10篇 |
2022年 | 10篇 |
2021年 | 15篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 28篇 |
2015年 | 43篇 |
2014年 | 44篇 |
2013年 | 78篇 |
2012年 | 74篇 |
2011年 | 61篇 |
2010年 | 49篇 |
2009年 | 45篇 |
2008年 | 57篇 |
2007年 | 58篇 |
2006年 | 42篇 |
2005年 | 44篇 |
2004年 | 43篇 |
2003年 | 42篇 |
2002年 | 45篇 |
2001年 | 22篇 |
2000年 | 40篇 |
1999年 | 39篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 11篇 |
1995年 | 15篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 17篇 |
1991年 | 25篇 |
1990年 | 15篇 |
1989年 | 18篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1986年 | 22篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
排序方式: 共有1191条查询结果,搜索用时 15 毫秒
921.
Phylogeographic analysis of the brown alga Cutleria multifida (Tilopteridales,Phaeophyceae) suggests a complicated introduction history
下载免费PDF全文
![点击此处可从《Phycological Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hiroshi Kawai Keita Kogishi Takeaki Hanyuda Shogo Arai C. Frederico Gurgel Wendy Nelson Alexandre Meinesz Kostas Tsiamis Akira F. Peters 《Phycological Research》2016,64(1):3-10
In depth genetic comparisons of populations of Cutleria multifida (Tilopteridales, Phaeophyceae) collected from Europe, the northwestern Pacific Ocean, Australia and New Zealand using the DNA sequences of four gene regions (the mitochondrial cox2 and cox3 genes, the intergeneric spacer region adjacent to cox3, and the open reading frame) suggested that the northwestern European and Japanese populations were considerably greater in terms of their genetic divergence than Mediterranean, Australian or New Zealand populations. The haplotypes of the populations in northwestern European (distribution range including the type locality, seven haplotypes) and Japanese populations (seven haplotypes) were unique except for one shared haplotype. There were weak but positive correlations between the geographical distance and the genetic divergence among northwestern European and Japanese populations. Moreover, both female and male gametophytes occurred in eight of the nine Japanese localities, suggesting Japanese populations showed normal sexual heteromorphic life history of the species. In light of these results, it appears that Japanese populations were native to the area despite earlier hypothesis. In contrast, Australian and New Zealand populations were composed of only one haplotype that is very close to those found in northwestern Europe and Japan, suggesting a recent introduction history from Europe (or from northeastern Asia via Europe) by ship transport to Australia and New Zealand. The Mediterranean populations included two haplotypes identical to those found in northwestern Europe and Japan, and it is suggestive of transoceanic introductions of some populations between Mediterranean and Japanese coasts. 相似文献
922.
Takahiko Mitsui Atsuko Araki Chihiro Miyashita Sachiko Ito Tamiko Ikeno Seiko Sasaki Takeya Kitta Kimihiko Moriya Kazutoshi Cho Keita Morioka Reiko Kishi Nobuo Shinohara Masayuki Takeda Katsuya Nonomura 《PloS one》2016,11(1)
Sexually dimorphic brain development and behavior are known to be influenced by sex hormones exposure in prenatal periods. On the other hand, second-to forth digit ratio (2D/4D) has been used as an indirect method to investigate the putative effects of prenatal exposure to androgen. In the present study, we herein investigated the relationship between gender-role play behavior and the second-to-fourth digit ratio (2D/4D), which has been used as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children. Among 4981 children who became 8 years old by November 2014 and were contactable for this survey by The Hokkaido Study of Environment and Children''s Health, 1631 (32.7%), who had data for 2D/4D and Pre-school Activities Inventory (PSAI) as well as data for the survey at baseline, were available for analysis. Parents sent reports of PSAI on the sex-typical characteristics, preferred toys, and play activities of children, and black and white photocopies of the left and right hand palms via mail. PSAI consisted of 12 masculine items and 12 feminine items, and a composite score was created by subtracting the feminine score from the masculine score, with higher scores representing masculine-typical behavior. While composite scores in PSAI were significantly higher in boys than in girls, 2D/4D was significantly lower in boys than in girls. Although the presence or absence of brothers or sisters affected the composite, masculine, and feminine scored of PSAI, a multivariate regression model revealed that 2D/4D negatively correlated with the composite scores of PSAI in boys, whereas no correlation was found in girls. Although 2D/4D negatively correlated with the masculine score in boys and girls, no correlation was observed between 2D/4D and the feminine score. In conclusion, although social factors, such as the existence of brother or sisters, affect dimorphic brain development and behavior in childhood, the present study revealed that the prenatal hormonal environment was an important factor influencing masculine-typical dimorphic brain development and behavior in school-aged children. 相似文献
923.
Hirofumi Nagayama Kounosuke Tomori Kanta Ohno Kayoko Takahashi Kakuya Ogahara Tatsunori Sawada Sei Uezu Ryutaro Nagatani Keita Yamauchi 《PloS one》2016,11(3)
Background
Care-home residents are mostly inactive, have little interaction with staff, and are dependent on staff to engage in daily occupations. We recently developed an iPad application called the Aid for Decision-making in Occupation Choice (ADOC) to promote shared decision-making in activities and occupation-based goal setting by choosing from illustrations describing daily activities. This study aimed to evaluate if interventions based on occupation-based goal setting using the ADOC could focus on meaningful activities to improve quality of life and independent activities of daily living, with greater cost-effectiveness than an impairment-based approach as well as to evaluate the feasibility of conducting a large cluster, randomized controlled trial.Method
In this single (assessor)-blind pilot cluster randomized controlled trial, the intervention group (ADOC group) received occupational therapy based on occupation-based goal setting using the ADOC, and the interventions were focused on meaningful occupations. The control group underwent an impairment-based approach focused on restoring capacities, without goal setting tools. In both groups, the 20-minute individualized intervention sessions were conducted twice a week for 4 months.Main Outcome Measures
Short Form-36 (SF-36) score, SF-6D utility score, quality adjusted life years (QALY), Barthel Index, and total care cost.Results
We randomized and analyzed 12 facilities (44 participants, 18.5% drop-out rate), with 6 facilities each allocated to the ADOC (n = 23) and control (n = 21) groups. After the 4-month intervention, the ADOC group had a significantly greater change in the BI score, with improved scores (P = 0.027, 95% CI 0.41 to 6.87, intracluster correlation coefficient = 0.14). No other outcome was significantly different. The incremental cost-effectiveness ratio, calculated using the change in BI score, was $63.1.Conclusion
The results suggest that occupational therapy using the ADOC for older residents might be effective and cost-effective. We also found that conducting an RCT in the occupational therapy setting is feasible.Trial Registration
UMIN Clinical Trials Registry UMIN000012994 相似文献924.
Caroline Bouchard Salomé Mollard Keita Suzuki Dominique Robert Louis Fortier 《Polar Biology》2016,39(6):1005-1022
The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener’s index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species. 相似文献
925.
Yoshiaki Masaki Keishi Yamamoto Takeshi Inde Keita Yoshida Atsuya Maruyama Tetsuya Nagata Jun Tanihata Shinichi Takeda Mitsuo Sekine Kohji Seio 《Bioorganic & medicinal chemistry letters》2019,29(2):160-163
The effect of 2′-O-(N-methylcarbamoyl)ethyl (MCE) modification on splice-switching oligonucleotides (SSO) was systematically evaluated. The incorporation of five MCE nucleotides at the 5′-termini of SSOs effectively improved the splice switching effect. In addition, the incorporation of 2′-O-(N-methylcarbamoylethyl)-5-methyl-2-thiouridine (s2TMCE), a duplex-stabilizing nucleotide with an MCE modification, into SSOs further improved splice switching. These SSOs may be useful for the treatment of genetic diseases associated with splicing errors. 相似文献
926.
Tatsuya Niwa Eri Uemura Yuki Matsuno Hideki Taguchi 《Protein science : a publication of the Protein Society》2019,28(7):1252-1261
Protein folding is an essential prerequisite for proteins to execute nearly all cellular functions. There is a growing demand for a simple and robust method to investigate protein folding on a large‐scale under the same conditions. We previously developed a global folding assay system, in which proteins translated using an Escherichia coli‐based cell‐free translation system are centrifuged to quantitate the supernatant fractions. Although the assay is based on the assumption that the supernatants contain the folded native states, the supernatants also include nonnative unstructured proteins. In general, proteases recognize and degrade unstructured proteins, and thus we used a protease to digest the unstructured regions to monitor the folding status. The addition of Lon protease during the translation of proteins unmasked subfractions, not only in the soluble fractions but also in the aggregation‐prone fractions. We translated ~90 E. coli proteins in the protease‐inclusion assay, in the absence and presence of chaperones. The folding assay, which sheds light on the molecular mechanisms underlying the aggregate formation and the chaperone effects, can be applied to a large‐scale analysis. 相似文献
927.
Kitazawa T Fukushima A Okugawa S Yanagimoto S Tsukada K Tatsuno K Koike K Kimura S Kishimoto T Shibasaki Y Ota Y 《Microbes and infection / Institut Pasteur》2007,9(12-13):1410-1414
Chlamydophila pneumoniae is known to be associated with atherosclerosis. Recent studies have reported that components of Chlamydophila pneumoniae (chlamydophilal antigens) induce foam cell formation in macrophages. However, the mechanism of foam cell formation induced by chlamydophilal antigens has yet to be elucidated. In this paper, we first found that mitogen-activated protein kinases including extracellular signal-regulated kinase, p38 and c-Jun NH2 terminal kinase are phosphorylated after stimulation by chlamydophilal antigens. We then showed that chlamydophilal antigens induce foam cell formation mainly via c-Jun NH2 terminal kinase. Finally, we demonstrated that foam cell formation and phosphorylation of mitogen-activated protein kinases induced by chlamydophilal antigens are mainly recognized through Toll-like receptor 2. These results collectively indicated that chlamydophilal antigens induce foam cell formation mainly via Toll-like receptor 2 and c-Jun NH2 terminal kinase. 相似文献
928.
Takaya A Kamio T Masuda M Mochizuki N Sawa H Sato M Nagashima K Mizutani A Matsuno A Kiyokawa E Matsuda M 《Molecular biology of the cell》2007,18(5):1850-1860
R-Ras is a Ras-family small GTPase that regulates various cellular functions such as apoptosis and cell adhesion. Here, we demonstrate a role of R-Ras in exocytosis. By the use of specific anti-R-Ras antibody, we found that R-Ras was enriched on both early and recycling endosomes in a wide range of cell lines. Using a fluorescence resonance energy transfer-based probe for R-Ras activity, R-Ras activity was found to be higher on endosomes than on the plasma membrane. This high R-Ras activity on the endosomes correlated with the accumulation of an R-Ras effector, the Rgl2/Rlf guanine nucleotide exchange factor for RalA, and also with high RalA activity. The essential role played by R-Ras in inducing high levels of RalA activity on the endosomes was evidenced by the short hairpin RNA (shRNA)-mediated suppression of R-Ras and by the expression of R-Ras GAP. In agreement with the reported role of RalA in exocytosis, the shRNA of either R-Ras or RalA was found to suppress calcium-triggered exocytosis in PC12 pheochromocytoma cells. These data revealed that R-Ras activates RalA on endosomes and that it thereby positively regulates exocytosis. 相似文献
929.
930.
Ogo N Oishi S Matsuno K Sawada J Fujii N Asai A 《Bioorganic & medicinal chemistry letters》2007,17(14):3921-3924
Inhibition of Eg5 represents a novel approach for the treatment of cancer. Here, we report the synthesis and structure-activity relationship of S-trityl-L-cysteine (STLC) derivatives as Eg5 inhibitors. Some of these derivatives such as 4f demonstrated enhanced inhibitory activity against Eg5 and induced mitotic arrest with characteristic monoastral spindles in HeLa cells. 相似文献