全文获取类型
收费全文 | 38759篇 |
免费 | 3512篇 |
国内免费 | 22篇 |
出版年
2023年 | 190篇 |
2022年 | 130篇 |
2021年 | 1013篇 |
2020年 | 559篇 |
2019年 | 720篇 |
2018年 | 854篇 |
2017年 | 693篇 |
2016年 | 1228篇 |
2015年 | 2037篇 |
2014年 | 2189篇 |
2013年 | 2467篇 |
2012年 | 3299篇 |
2011年 | 3314篇 |
2010年 | 2023篇 |
2009年 | 1660篇 |
2008年 | 2452篇 |
2007年 | 2391篇 |
2006年 | 2306篇 |
2005年 | 1948篇 |
2004年 | 1955篇 |
2003年 | 1724篇 |
2002年 | 1650篇 |
2001年 | 395篇 |
2000年 | 308篇 |
1999年 | 357篇 |
1998年 | 355篇 |
1997年 | 255篇 |
1996年 | 225篇 |
1995年 | 198篇 |
1994年 | 188篇 |
1993年 | 182篇 |
1992年 | 175篇 |
1991年 | 189篇 |
1990年 | 152篇 |
1989年 | 157篇 |
1988年 | 117篇 |
1987年 | 125篇 |
1986年 | 136篇 |
1985年 | 149篇 |
1984年 | 138篇 |
1983年 | 141篇 |
1982年 | 148篇 |
1981年 | 140篇 |
1980年 | 130篇 |
1979年 | 118篇 |
1978年 | 65篇 |
1977年 | 71篇 |
1976年 | 78篇 |
1975年 | 79篇 |
1974年 | 85篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Andrew C Smith 《BMJ (Clinical research ed.)》1981,283(6306):1596-1597
4.
Denise Risch Nicholas J. Gales Jason Gedamke Lars Kindermann Douglas P. Nowacek Andrew J. Read Ursula Siebert Ilse C. Van Opzeeland Sofie M. Van Parijs Ari S. Friedlaender 《Biology letters》2014,10(4)
For decades, the bio-duck sound has been recorded in the Southern Ocean, but the animal producing it has remained a mystery. Heard mainly during austral winter in the Southern Ocean, this ubiquitous sound has been recorded in Antarctic waters and contemporaneously off the Australian west coast. Here, we present conclusive evidence that the bio-duck sound is produced by Antarctic minke whales (Balaenoptera bonaerensis). We analysed data from multi-sensor acoustic recording tags that included intense bio-duck sounds as well as singular downsweeps that have previously been attributed to this species. This finding allows the interpretation of a wealth of long-term acoustic recordings for this previously acoustically concealed species, which will improve our understanding of the distribution, abundance and behaviour of Antarctic minke whales. This is critical information for a species that inhabits a difficult to access sea-ice environment that is changing rapidly in some regions and has been the subject of contentious lethal sampling efforts and ongoing international legal action. 相似文献
5.
Minh Thac Nguyen Ryan Denniston Hien Thi Thu Nguyen Tuan Anh Hoang Hana Ross Anthony D. So 《PloS one》2014,9(1)
Illicit trade carries the potential to magnify existing tobacco-related health care costs through increased availability of untaxed and inexpensive cigarettes. What is known with respect to the magnitude of illicit trade for Vietnam is produced primarily by the industry, and methodologies are typically opaque. Independent assessment of the illicit cigarette trade in Vietnam is vital to tobacco control policy. This paper measures the magnitude of illicit cigarette trade for Vietnam between 1998 and 2010 using two methods, discrepancies between legitimate domestic cigarette sales and domestic tobacco consumption estimated from surveys, and trade discrepancies as recorded by Vietnam and trade partners. The results indicate that Vietnam likely experienced net smuggling in during the period studied. With the inclusion of adjustments for survey respondent under-reporting, inward illicit trade likely occurred in three of the four years for which surveys were available. Discrepancies in trade records indicate that the value of smuggled cigarettes into Vietnam ranges from $100 million to $300 million between 2000 and 2010 and that these cigarettes primarily originate in Singapore, Hong Kong, Macao, Malaysia, and Australia. Notable differences in trends over time exist between the two methods, but by comparison, the industry estimates consistently place the magnitude of illicit trade at the upper bounds of what this study shows. The unavailability of annual, survey-based estimates of consumption may obscure the true, annual trend over time. Second, as surveys changed over time, estimates relying on them may be inconsistent with one another. Finally, these two methods measure different components of illicit trade, specifically consumption of illicit cigarettes regardless of origin and smuggling of cigarettes into a particular market. However, absent a gold standard, comparisons of different approaches to illicit trade measurement serve efforts to refine and improve measurement approaches and estimates. 相似文献
6.
7.
Benjamin C. Blum Weiwei Lin Matthew L. Lawton Qian Liu Julian Kwan Isabella Turcinovic Ryan Hekman Pingzhao Hu Andrew Emili 《Molecular & cellular proteomics : MCP》2022,21(1):100189
Metabolism is recognized as an important driver of cancer progression and other complex diseases, but global metabolite profiling remains a challenge. Protein expression profiling is often a poor proxy since existing pathway enrichment models provide an incomplete mapping between the proteome and metabolism. To overcome these gaps, we introduce multiomic metabolic enrichment network analysis (MOMENTA), an integrative multiomic data analysis framework for more accurately deducing metabolic pathway changes from proteomics data alone in a gene set analysis context by leveraging protein interaction networks to extend annotated metabolic models. We apply MOMENTA to proteomic data from diverse cancer cell lines and human tumors to demonstrate its utility at revealing variation in metabolic pathway activity across cancer types, which we verify using independent metabolomics measurements. The novel metabolic networks we uncover in breast cancer and other tumors are linked to clinical outcomes, underscoring the pathophysiological relevance of the findings. 相似文献
8.
Andrew Leask 《Journal of cell communication and signaling》2010,4(1):71-72
Connective tissue growth factor (CTGF/CCN2) is overexpressed in diabetes. Diabetic rats possess myocardial and cardiomyocyte
hypertrophy. In a recent report, Wang and colleagues (Am J Physiol Cell Physiol. 2009 Jul 22. [Epub ahead of print]) show
that CCN2 directly mediates cardiomyocyte hypertrophy as well as that induced by high glucose and fatty acid. CCN2 acted via
the TrkA receptor. These data are the subject of this commentary, and emphasize that CCN2 may be an excellent target for therapy
in diabetes. 相似文献
9.
10.
Andrew Bamji 《BMJ (Clinical research ed.)》1987,294(6574):772-773