全文获取类型
收费全文 | 3302篇 |
免费 | 195篇 |
出版年
2022年 | 5篇 |
2021年 | 42篇 |
2020年 | 25篇 |
2019年 | 24篇 |
2018年 | 47篇 |
2017年 | 47篇 |
2016年 | 58篇 |
2015年 | 107篇 |
2014年 | 132篇 |
2013年 | 200篇 |
2012年 | 204篇 |
2011年 | 227篇 |
2010年 | 147篇 |
2009年 | 145篇 |
2008年 | 224篇 |
2007年 | 228篇 |
2006年 | 191篇 |
2005年 | 180篇 |
2004年 | 190篇 |
2003年 | 193篇 |
2002年 | 207篇 |
2001年 | 56篇 |
2000年 | 51篇 |
1999年 | 56篇 |
1998年 | 41篇 |
1997年 | 31篇 |
1996年 | 24篇 |
1995年 | 31篇 |
1994年 | 27篇 |
1993年 | 41篇 |
1992年 | 22篇 |
1991年 | 35篇 |
1990年 | 26篇 |
1989年 | 25篇 |
1988年 | 19篇 |
1987年 | 23篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 12篇 |
1982年 | 15篇 |
1981年 | 6篇 |
1980年 | 16篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 9篇 |
1974年 | 5篇 |
1973年 | 4篇 |
排序方式: 共有3497条查询结果,搜索用时 46 毫秒
31.
32.
Tohru Tanigawa Rei Shibata Kazuhisa Kondo Nobuyuki Katahira Takahiro Kambara Yoko Inoue Hiroshi Nonoyama Yuichiro Horibe Hiromi Ueda Toyoaki Murohara 《PloS one》2015,10(9)
Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress. 相似文献
33.
Edward E. Nishizawa William L. Miller Robert R. Gorman Gordon L. Bundy Jan Svensson Mats Hamberg 《Prostaglandins & other lipid mediators》1975,9(1)
Prostaglandin D2 was found to be a potent inhibitor of platelet aggregation. Aggregation of human platelets by ADP, collagen and prostaglandin G2 was inhibited more strongly by PGD2 than by PGE1. Although ADP-induced aggregation of rabbit platelets was inhibited more strongly by PGE1 than by PGD2 the latter prostaglandin gave a more long-lasting inhibitory effect on platelet aggregation following intravenous or oral administration. These results coupled with the finding that PGD2 has less hypotensive effects on the cardiovascular system than PGE1 suggest the possible use of PGD2 as an antithrombotic agent. 相似文献
34.
Contribution of central versus sweat gland mechanisms to the seasonal change of sweating function in young sedentary males and females 总被引:1,自引:0,他引:1
Yumiko Taniguchi Junichi Sugenoya Naoki Nishimura Satoshi Iwase Takaaki Matsumoto Yuuki Shimizu Yoko Inukai Maki Sato 《International journal of biometeorology》2011,55(2):203-212
In summer and winter, young, sedentary male (N = 5) and female (N = 7) subjects were exposed to heat in a climate chamber in which ambient temperature (Ta) was raised continuously from 30
to 42°C at a rate of 0.1°C min−1 at a relative humidity of 40%. Sweat rates (SR) were measured continuously on forearm, chest and forehead together with tympanic
temperature (Tty), mean skin temperature ( [`T] s ) \left( {\overline {\hbox{T}} {\hbox{s}}} \right) and mean body temperature ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) . The rate of sweat expulsions (Fsw) was obtained as an indicator of central sudomotor activity. Tty and ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) were significantly lower during summer compared with winter in males; SR was not significantly different between summer and
winter in males, but was significantly higher during summer in females; SR during winter was higher in males compared with
females. The regression line relating Fsw to ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) shifted significantly from winter to summer in males and females, but the magnitude of the shift was not significantly different
between the two subject groups. The regression line relating SR to Fsw was steepened significantly from winter to summer in
males and females, and the change in the slope was significantly greater in females than in males. Females showed a lower
slope in winter and a similar slope in summer compared to males. It was concluded that sweating function was improved during
summer mediated by central sudomotor and sweat gland mechanisms in males and females, and, although the change of sweat gland
function from winter to summer was greater in females as compared with males, the level of increased sweat gland function
during summer was similar between the two subject groups. 相似文献
35.
Ryuichi Ono Yoko Kuroki Mie Naruse Masayuki Ishii Sawa Iwasaki Atsushi Toyoda Asao Fujiyama Geoff Shaw Marilyn B. Renfree Tomoko Kaneko-Ishino Fumitoshi Ishino 《DNA research》2011,18(4):211-219
In humans and mice, there are 11 genes derived from sushi-ichi related retrotransposons, some of which are known to play essential roles in placental development. Interestingly, this family of retrotransposons was thought to exist only in eutherian mammals, indicating their significant contributions to the eutherian evolution, but at least one, PEG10, is conserved between marsupials and eutherians. Here we report a novel sushi-ichi retrotransposon-derived gene, SIRH12, in the tammar wallaby, an Australian marsupial species of the kangaroo family. SIRH12 encodes a protein highly homologous to the sushi-ichi retrotransposon Gag protein in the tammar wallaby, while SIRH12 in the South American short-tailed grey opossum is a pseudogene degenerated by accumulation of multiple nonsense mutations. This suggests that SIRH12 retrotransposition occurred only in the marsupial lineage but acquired and retained some as yet unidentified novel function, at least in the lineage of the tammar wallaby. 相似文献
36.
37.
Yuji Kawaguchi Shinya Fukumoto Masaaki Inaba Hidenori Koyama Tetsuo Shoji Shigeichi Shoji Yoshiki Nishizawa 《Obesity (Silver Spring, Md.)》2011,19(2):276-282
Our aim was to investigate the significance of neck circumference (NC) on the presence and severity of obstructive sleep apnea (OSA) syndrome independent of visceral fat (VF) obesity. A total of 219 subjects with suspected OSA underwent a complete polysomnography (PSG) study, along with the measurement of NC, and total body fat (TF) and VF levels (VFLs) measured by bioelectrical impedance analysis. We proposed NC divided by height (NC/H) as the simple index for height‐corrected NC in Japanese subjects. NC/H exhibited a significantly stronger correlation than NC per se with BMI (r = 0.781 vs. 0.675, P = 0.0178), TF (r = 0.531 vs. 0.156, P < 0.0001), and VF (r = 0.819 vs. 0.731, P = 0.0203), indicating that NC/H is a better indicator of visceral obesity than NC per se. Interestingly, despite the strong correlation between NC/H and VFL, VFL was significantly associated with the apnea‐hypopnea index (AHI) ≥5, ≥15, and ≥30, but not with ≥40 or ≥50, whereas NC/H was significantly associated with higher AHI values, i.e., AHI ≥50 but not with lower AHI value. Furthermore, multiple regression analyses revealed that VFL and NC/H were independently associated with the square root of AHI (AHI0.5) levels in obese and nonobese patients, respectively. In conclusion, NC is associated with the severity of OSA independently of visceral obesity, especially in nonobese patients. 相似文献
38.
Yoko Nishimura Taisuke Ohtsuka Kohei Yoshiyama Daisuke Nakai Fujiyoshi Shibahara Masayoshi Maehata 《Ecological Research》2011,26(3):615-626
Effects of fish predation propagate through aquatic food webs, where the classical grazing food chain and microbial loop are
interwoven by trophic interactions. The overall impact on aquatic food webs is further complicated because fish may also exert
bottom-up controls through nutrient regeneration. Yet, we still have limited information about cascading effects among fish,
zooplankton, phytoplankton, and microbes. In this study, we performed a mesocosm experiment to evaluate effects of fish introduction
on plankton communities. Six plots were set in factorial combination with fish introduction and rice straw plowing in a paddy
field, and the experiment was continued for 4 weeks. Introduction of fish significantly increased chlorophyll a concentrations in smaller size fractions (<15 μm) and abundances of filamentous bacteria (>5 μm in length) and heterotrophic
nanoflagellates in 3–15 μm fraction. Microbes in 0.8–3 μm fraction showed increasing but not significant trends in response
to fish introduction. These results indicate cascading effects of fish predation operating via two pathways, one through grazing
food chain and the other through microbial food web. Phytoplankton community compositions shifted in similar fashion in all
plots until 1 week after fish introduction, and then diverged between plots with and without fish thereafter. Bottom-up effects
of fish introduction were suggested by increases of total chlorophyll a and inedible phytoplankton species in response to fish introduction. This study provides an example of how fish predation
regulates biomass and structure of phytoplankton and microbial communities. 相似文献
39.
Iara Augusta Orsi Adalton Garcia Junior Camilo Andrés Villabona Flávio Henrique Carriço Nogueira Fernandes Isabel Yoko Ito 《Gerodontology》2011,28(4):253-257
doi: 10.1111/j.1741‐2358.2010.00400.x Evaluation of the efficacy of chemical disinfectants for disinfection of heat‐polymerised acrylic resin Objective: This study evaluated the efficacy of disinfectants on the internal aspect of heat‐polymerised acrylic resin contaminated with microbial strains. Background: Dentures absorb oral fluids and become contaminated by different microorganisms. Methods: Two hundred and fifty rectangular specimens were made of heat‐polymerised acrylic resin, and then divided into five groups corresponding to the microbial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, S. mutans and Enterococcus faecalis). After contamination, the specimens were immersed in 1 and 2% sodium hypochlorite and 2% glutaraldehyde for periods of 5, 10 and 15 min. The specimens were placed into tubes containing different broths and incubated at 35°C and then visually analysed. Turbidity in the medium indicated microbial growth. The Fisher’s exact test was used in the analysis of the results. Results: The strain E. faecalis was the most resistant to the disinfectant solutions, and among them, glutaraldehyde was more effective than 2 and 1% hypochlorite for disinfection for 5 min; in the 10‐min period there were no differences between the disinfectants. In 15 min of immersion, 1% hypochlorite and glutaraldehyde were more effective than 2% hypochlorite. Conclusions: Disinfection for 10 min with 1% hypochlorite and glutaraldehyde is effective in disinfecting the internal aspect of heat‐polymerised acrylic resin. 相似文献
40.
Alison Shapcott Heather James Laura Simmons Yoko Shimizu Lauren Gardiner David Rabehevitra Rokiman Letsara Stuart Cable John Dransfield William J. Baker Mijoro Rakotoarinivo 《Ecology and evolution》2020,10(6):3120-3137
Madagascar is home to 208 indigenous palm species, almost all of them endemic and >80% of which are endangered. We undertook complete population census and sampling for genetic analysis of a relatively recently discovered giant fan palm, the Critically Endangered Tahina spectablis in 2008 and 2016. Our 2016 study included newly discovered populations and added to our genetic study. We incorporated these new populations into species distribution niche model (SDM) and projected these onto maps of the region. We developed population matrix models based on observed demographic data to model population change and predict the species vulnerability to extinction by undertaking population viability analysis (PVA). We investigated the potential conservation value of reintroduced planted populations within the species potential suitable habitat. We found that the population studied in 2008 had grown in size due to seedling regeneration but had declined in the number of reproductively mature plants, and we were able to estimate that the species reproduces and dies after approximately 70 years. Our models suggest that if the habitat where it resides continues to be protected the species is unlikely to go extinct due to inherent population decline and that it will likely experience significant population growth after approximately 80 years due to the reproductive and life cycle attributes of the species. The newly discovered populations contain more genetic diversity than the first discovered southern population which is genetically depauperate. The species appears to demonstrate a pattern of dispersal leading to isolated founder plants which may eventually lead to population development depending on local establishment opportunities. The conservation efforts currently put in place including the reintroduction of plants within the species potential suitable habitat if maintained are thought likely to enable the species to sustain itself but it remains vulnerable to anthropogenic impacts. 相似文献