全文获取类型
收费全文 | 1337篇 |
免费 | 168篇 |
专业分类
1505篇 |
出版年
2022年 | 10篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 21篇 |
2015年 | 37篇 |
2014年 | 44篇 |
2013年 | 53篇 |
2012年 | 61篇 |
2011年 | 81篇 |
2010年 | 46篇 |
2009年 | 38篇 |
2008年 | 53篇 |
2007年 | 53篇 |
2006年 | 67篇 |
2005年 | 61篇 |
2004年 | 53篇 |
2003年 | 59篇 |
2002年 | 54篇 |
2001年 | 43篇 |
2000年 | 36篇 |
1999年 | 39篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 31篇 |
1991年 | 31篇 |
1990年 | 25篇 |
1989年 | 33篇 |
1988年 | 25篇 |
1987年 | 17篇 |
1986年 | 23篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 19篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 15篇 |
1979年 | 22篇 |
1978年 | 16篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1974年 | 12篇 |
1973年 | 11篇 |
1972年 | 7篇 |
1970年 | 12篇 |
排序方式: 共有1505条查询结果,搜索用时 0 毫秒
41.
James F. Harwood Roger I. Vargas James R. Carey 《Entomologia Experimentalis et Applicata》2013,147(1):73-81
Injuries frequently accumulate with age in nature. Despite the commonality of injury and the resulting impairment, there are limited experimental data for the effects of impairment on life history trade‐offs between reproduction and survival in insects. We tested the effects of artificial injury and the resulting impairment on the reproductive costs and behavior of male medflies, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Treatment flies were impaired by amputating tarsomere segments 2–5 from the right foreleg at either eclosion or age 22 days. The effect of impairment and age on the cost of reproduction was tested by varying the timing of female availability among the treatments. Courtship behavior and copulation rates were observed hourly from age 2–5 days to determine the effects of impairment on reproductive behavior. Female access combined with the impairment reduced the life expectancy of males more than the impairment alone, whereas the health effect of amputation was influenced by age. Conversely, the risk of death due to impairment was not influenced by the males' mating status prior to amputation. The males' copulation success was reduced due to impairment, whereas courtship behavior was not affected. Impairment does not reduce the males' impulse to mate, but decreases the females' receptivity to copulation, while also increasing the cost of each successful mating. Overall, minor impairment lowers the reproductive success of males and reduces longevity. 相似文献
42.
Yuzuru Sanemitsu Norio Kurihara Minoru Nakajima G. E. McCasland L. F. Johnson L. C. Carey 《Bioscience, biotechnology, and biochemistry》2013,77(5):845-857
Two diastereomers of 6-bromo-1, 2, 3, 4, 5-pentachlorocyclohexane were synthesized from the dl (36/45)-diastereomer of 3, 4, 5, 6-tetrachlorocyclohexene (α-BTC) and the dl (346/5)-diastereomer (γ-BTC) by several stepwise routes. Both of these new products were shown to have the configuration of lindane by NMR studies at 300 MHz and by the synthetic routes. Three diastereomers of 6-bromo-3, 4, 5-trichlorocyclohexene were also prepared and the configurations determined partly by means of 300 MHz NMR. 相似文献
43.
44.
Linda M. Delahanty Thomas A. Wadden Pamela J. Goodwin Catherine M. Alfano Cynthia A. Thomson Melinda L. Irwin Marian L. Neuhouser Tracy E. Crane Elizabeth Frank Patricia A. Spears Bonnie P. Gillis Dawn L. Hershman Electra D. Paskett Judith Hopkins Vanessa Bernstein Vered Stearns Julia White Clifford Hudis Eric P. Winer Lisa A. Carey Ann H. Partridge Jennifer A. Ligibel 《Obesity (Silver Spring, Md.)》2022,30(1):28-38
45.
46.
47.
48.
Wittenburg H Lyons MA Li R Kurtz U Wang X Mössner J Churchill GA Carey MC Paigen B 《Journal of lipid research》2006,47(8):1780-1790
To identify additional loci that influence lipoprotein cholesterol levels, we performed quantitative trait locus (QTL) mapping in offspring of PERA/EiJxI/LnJ and PERA/EiJxDBA/2J intercrosses and in a combined data set from both crosses after 8 weeks of consumption of a high fat-diet. Most QTLs identified were concordant with homologous chromosomal regions that were associated with lipoprotein levels in human studies. We detected significant new loci for HDL cholesterol levels on chromosome (Chr) 5 (Hdlq34) and for non-HDL cholesterol levels on Chrs 15 (Nhdlq9) and 16 (Nhdlq10). In addition, the analysis of combined data sets identified a QTL for HDL cholesterol on Chr 17 that was shared between both crosses; lower HDL cholesterol levels were conferred by strain PERA. This QTL colocalized with a shared QTL for cholesterol gallstone formation detected in the same crosses. Haplotype analysis narrowed this QTL, and sequencing of the candidate genes Abcg5 and Abcg8 confirmed shared alleles in strains I/LnJ and DBA/2J that differed from the alleles in strain PERA/EiJ. In conclusion, our analysis furthers the knowledge of genetic determinants of lipoprotein cholesterol levels in inbred mice and substantiates the hypothesis that polymorphisms of Abcg5/Abcg8 contribute to individual variation in both plasma HDL cholesterol levels and susceptibility to cholesterol gallstone formation. 相似文献
49.
Mitchell N. Sarkies Lauren M. Robins Megan Jepson Cylie M. Williams Nicholas F. Taylor Lisa OBrien Jenny Martin Anne Bardoel Meg E. Morris Leeanne M. Carey Anne E. Holland Katrina M. Long Terry P. Haines 《PLoS medicine》2021,18(10)
BackgroundImplementing evidence into clinical practice is a key focus of healthcare improvements to reduce unwarranted variation. Dissemination of evidence-based recommendations and knowledge brokering have emerged as potential strategies to achieve evidence implementation by influencing resource allocation decisions. The aim of this study was to determine the effectiveness of these two research implementation strategies to facilitate evidence-informed healthcare management decisions for the provision of inpatient weekend allied health services.Methods and findingsThis multicentre, single-blinded (data collection and analysis), three-group parallel cluster randomised controlled trial with concealed allocation was conducted in Australian and New Zealand hospitals between February 2018 and January 2020. Clustering and randomisation took place at the organisation level where weekend allied health staffing decisions were made (e.g., network of hospitals or single hospital). Hospital wards were nested within these decision-making structures. Three conditions were compared over a 12-month period: (1) usual practice waitlist control; (2) dissemination of written evidence-based practice recommendations; and (3) access to a webinar-based knowledge broker in addition to the recommendations. The primary outcome was the alignment of weekend allied health provision with practice recommendations at the cluster and ward levels, addressing the adoption, penetration, and fidelity to the recommendations. The secondary outcome was mean hospital length of stay at the ward level. Outcomes were collected at baseline and 12 months later. A total of 45 clusters (n = 833 wards) were randomised to either control (n = 15), recommendation (n = 16), or knowledge broker (n = 14) conditions. Four (9%) did not provide follow-up data, and no adverse events were recorded. No significant effect was found with either implementation strategy for the primary outcome at the cluster level (recommendation versus control β 18.11 [95% CI −8,721.81 to 8,758.02] p = 0.997; knowledge broker versus control β 1.24 [95% CI −6,992.60 to 6,995.07] p = 1.000; recommendation versus knowledge broker β −9.12 [95% CI −3,878.39 to 3,860.16] p = 0.996) or ward level (recommendation versus control β 0.01 [95% CI 0.74 to 0.75] p = 0.983; knowledge broker versus control β −0.12 [95% CI −0.54 to 0.30] p = 0.581; recommendation versus knowledge broker β −0.19 [−1.04 to 0.65] p = 0.651). There was no significant effect between strategies for the secondary outcome at ward level (recommendation versus control β 2.19 [95% CI −1.36 to 5.74] p = 0.219; knowledge broker versus control β −0.55 [95% CI −1.16 to 0.06] p = 0.075; recommendation versus knowledge broker β −3.75 [95% CI −8.33 to 0.82] p = 0.102). None of the control or knowledge broker clusters transitioned to partial or full alignment with the recommendations. Three (20%) of the clusters who only received the written recommendations transitioned from nonalignment to partial alignment. Limitations include underpowering at the cluster level sample due to the grouping of multiple geographically distinct hospitals to avoid contamination.ConclusionsOwing to a lack of power at the cluster level, this trial was unable to identify a difference between the knowledge broker strategy and dissemination of recommendations compared with usual practice for the promotion of evidence-informed resource allocation to inpatient weekend allied health services. Future research is needed to determine the interactions between different implementation strategies and healthcare contexts when translating evidence into healthcare practice.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12618000029291.In a cluster randomized controlled implementation trial, Dr. Mitchell N Sarkies and colleagues examine the effectiveness of knowledge brokering and recommendation dissemination in influencing healthcare resource allocation decisions in Australia and New Zealand. 相似文献
50.
RPPAML/RIMS: A metadata format and an information management system for reverse phase protein arrays
Romesh Stanislaus Mark Carey Helena F Deus Kevin Coombes Bryan T Hennessy Gordon B Mills Jonas S Almeida 《BMC bioinformatics》2008,9(1):555