全文获取类型
收费全文 | 645篇 |
免费 | 86篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 29篇 |
2015年 | 32篇 |
2014年 | 37篇 |
2013年 | 33篇 |
2012年 | 49篇 |
2011年 | 39篇 |
2010年 | 29篇 |
2009年 | 27篇 |
2008年 | 23篇 |
2007年 | 29篇 |
2006年 | 27篇 |
2005年 | 18篇 |
2004年 | 20篇 |
2003年 | 23篇 |
2002年 | 22篇 |
2001年 | 27篇 |
2000年 | 22篇 |
1999年 | 20篇 |
1998年 | 17篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1972年 | 4篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有731条查询结果,搜索用时 625 毫秒
681.
682.
Kyran M. Staunton Donovan Leiva Alvaro Cruz Joelyn Goi Carlos Arisqueta Jianyi Liu Mark Desnoyer Paul Howell Francia Espinosa Azael Che Mendoza Stephan Karl Jacob E. Crawford Wei Xiang Pablo Manrique-Saide Nicole L. Achee John P. Grieco Scott A. Ritchie Thomas R. Burkot Nigel Snoad 《PLoS neglected tropical diseases》2021,15(2)
Aedes aegypti and Aedes albopictus vector dengue, chikungunya and Zika viruses. With both species expanding their global distributions at alarming rates, developing effective surveillance equipment is a continuing priority for public health researchers. Sound traps have been shown, in limited testing, to be highly species-specific when emitting a frequency corresponding to a female mosquito wingbeat. Determining male mosquito capture rates in sound traps based on lure frequencies in endemic settings is the next step for informed deployment of these surveillance tools. We field-evaluated Male Aedes Sound Traps (MASTs) set to either 450 Hz, 500 Hz, 550 Hz or 600 Hz for sampling Aedes aegypti and/or Aedes albopictus and compared catch rates to BG-Sentinel traps within Pacific (Madang, Papua New Guinea) and Latin American (Molas, Mexico and Orange Walk Town, Belize) locations. MASTs set to 450–550 Hz consistently caught male Ae. aegypti at rates comparable to BG-Sentinel traps in all locations. A peak in male Ae. albopictus captures in MASTs set at 550 Hz was observed, with the lowest mean abundance recorded in MASTs set to 450 Hz. While significantly higher abundances of male Culex were sampled in MASTs emitting lower relative frequencies in Molas, overall male Culex were captured in significantly lower abundances in the MASTs, relative to BG-Sentinel traps within all locations. Finally, significant differences in rates at which male Aedes and Culex were positively detected in trap-types per weekly collections were broadly consistent with trends in abundance data per trap-type. MASTs at 550 Hz effectively captured both male Ae. aegypti and Ae. albopictus while greatly reducing bycatch, especially male Culex, in locations where dengue transmission has occurred. This high species-specificity of the MAST not only reduces staff-time required to sort samples, but can also be exploited to develop an accurate smart-trap system—both outcomes potentially reducing public health program expenses. 相似文献
683.
684.
The effect of high doses of ethanol (2 and 4 g/kg) administered to rats in pre-ovulatory periods (18th hour of diestrus) was studied. Plasma levels of estradiol and progesterone were measured at 10 hours of oestrus and changes in the ovarian cycle and the number of mature follicles were recorded. Compared with the control group, the receptive phase of estrus of the treated animals was longer lasting over 2 to 3 days. There was also an increase in the number of mature follicles as well as an increase in the plasma level of estradiol on the morning of estrus. Progesterone values showed no significant variations. Ethanol administered at the 18th hour of diestrus inhibits ovulation but not follicle development and allows the maintenance of high levels of estrogens on the morning of estrus. As a result the keratinization of the vaginal epithelium and the estrus phase are prolonged by 2 or 3 days. 相似文献
685.
Glucose release activity in mantle tissue of Mytilus galloprovincialis was studied. Mantle tissue shows a basal glucose releasing activity. The external Ca2+ absence increases 2 to 3-fold the basal glucose release, and when A23187 (10 microM) was simultaneously present the release doubled that obtained in Ca2(+)-absence. EGTA (2 mM), chlorpromazine (200 microM) and lanthanum (3 mM) decreased the glucose release promoted by external Ca2+ absence. This and other data suggest that glucose release activity in mantle tissue might be controlled by Ca2+ ions. 相似文献
686.
687.
688.
William W. Driscoll Jennifer H. Wisecaver Jeremiah D. Hackett Noelle J. Espinosa Jared Padway Jessica E. Engers Jessica A. Bower 《Ecology letters》2023,26(5):677-691
Much of the evolutionary ecology of toxic algal blooms (TABs) remains unclear, including the role of algal toxins in the adaptive ‘strategies’ of TAB-forming species. Most eukaryotic TABs are caused by mixotrophs that augment autotrophy with organic nutrient sources, including competing algae (intraguild predation). We leverage the standing diversity of TABs formed by the toxic, invasive mixotroph Prymnesium parvum to identify cell-level behaviours involved in toxin-assisted predation using direct observations as well as comparisons between genetically distinct low- and high-toxicity isolates. Our results suggest that P. parvum toxins are primarily delivered at close range and promote subsequent prey capture/consumption. Surprisingly, we find opposite chemotactic preferences for organic (prey-derived) and inorganic nutrients between differentially toxic isolates, respectively, suggesting behavioural integration of toxicity and phagotrophy. Variation in toxicity may, therefore, reflect broader phenotypic integration of key traits that ultimately contribute to the remarkable flexibility, diversity, and success of invasive populations. 相似文献
689.
Sara E. Cannon Simon D. Donner Angela Liu Pedro C. González Espinosa Andrew H. Baird Julia K. Baum Andrew G. Bauman Maria Beger Cassandra E. Benkwitt Matthew J. Birt Yannick Chancerelle Joshua E. Cinner Nicole L. Crane Vianney Denis Martial Depczynski Nur Fadli Douglas Fenner Christopher J. Fulton Yimnang Golbuu Nicholas A. J. Graham James Guest Hugo B. Harrison Jean-Paul A. Hobbs Andrew S. Hoey Thomas H. Holmes Peter Houk Fraser A. Januchowski-Hartley Jamaluddin Jompa Chao-Yang Kuo Gino Valentino Limmon Yuting V. Lin Timothy R. McClanahan Dominic Muenzel Michelle J. Paddack Serge Planes Morgan S. Pratchett Ben Radford James Davis Reimer Zoe T. Richards Claire L. Ross John Rulmal Jr. Brigitte Sommer Gareth J. Williams Shaun K. Wilson 《Global Change Biology》2023,29(12):3318-3330
Scientists and managers rely on indicator taxa such as coral and macroalgal cover to evaluate the effects of human disturbance on coral reefs, often assuming a universally positive relationship between local human disturbance and macroalgae. Despite evidence that macroalgae respond to local stressors in diverse ways, there have been few efforts to evaluate relationships between specific macroalgae taxa and local human-driven disturbance. Using genus-level monitoring data from 1205 sites in the Indian and Pacific Oceans, we assess whether macroalgae percent cover correlates with local human disturbance while accounting for factors that could obscure or confound relationships. Assessing macroalgae at genus level revealed that no genera were positively correlated with all human disturbance metrics. Instead, we found relationships between the division or genera of algae and specific human disturbances that were not detectable when pooling taxa into a single functional category, which is common to many analyses. The convention to use percent cover of macroalgae as an indication of local human disturbance therefore likely obscures signatures of local anthropogenic threats to reefs. Our limited understanding of relationships between human disturbance, macroalgae taxa, and their responses to human disturbances impedes the ability to diagnose and respond appropriately to these threats. 相似文献
690.
Andrés F Flórez Daeui Park Jong Bhak Byoung-Chul Kim Allan Kuchinsky John H Morris Jairo Espinosa Carlos Muskus 《BMC bioinformatics》2010,11(1):484