全文获取类型
收费全文 | 4640篇 |
免费 | 477篇 |
国内免费 | 4篇 |
出版年
2023年 | 11篇 |
2022年 | 30篇 |
2021年 | 76篇 |
2020年 | 46篇 |
2019年 | 41篇 |
2018年 | 68篇 |
2017年 | 52篇 |
2016年 | 99篇 |
2015年 | 172篇 |
2014年 | 185篇 |
2013年 | 234篇 |
2012年 | 325篇 |
2011年 | 332篇 |
2010年 | 199篇 |
2009年 | 204篇 |
2008年 | 290篇 |
2007年 | 289篇 |
2006年 | 242篇 |
2005年 | 257篇 |
2004年 | 230篇 |
2003年 | 210篇 |
2002年 | 196篇 |
2001年 | 91篇 |
2000年 | 117篇 |
1999年 | 94篇 |
1998年 | 65篇 |
1997年 | 65篇 |
1996年 | 49篇 |
1995年 | 63篇 |
1994年 | 42篇 |
1993年 | 47篇 |
1992年 | 59篇 |
1991年 | 69篇 |
1990年 | 55篇 |
1989年 | 44篇 |
1988年 | 52篇 |
1987年 | 53篇 |
1986年 | 39篇 |
1985年 | 37篇 |
1984年 | 28篇 |
1983年 | 16篇 |
1982年 | 23篇 |
1981年 | 17篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 19篇 |
1977年 | 11篇 |
1975年 | 16篇 |
1974年 | 18篇 |
1973年 | 10篇 |
排序方式: 共有5121条查询结果,搜索用时 15 毫秒
1.
Sebastián Moran Miguel Vizoso Anna Martinez-Cardús Antonio Gomez Xavier Matías-Guiu Sebastián M Chiavenna Andrés G Fernandez Manel Esteller 《Epigenetics》2014,9(6):829-833
A formalin-fixed paraffin-embedded (FFPE) sample usually yields highly degraded DNA, which limits the use of techniques requiring high-quality DNA, such as Infinium Methylation microarrays. To overcome this restriction, we have applied an FFPE restoration procedure consisting of DNA repair and ligation processes in a set of paired fresh-frozen (FF) and FFPE samples. We validated the FFPE results in comparison with matched FF samples, enabling us to use FFPE samples on the Infinium HumanMethylation450 Methylation array. 相似文献
2.
Condon Tom Hakim Abbas Moran Antonio B. Zenteno Blumstein Daniel T. 《Journal of Ethology》2021,39(1):89-96
Journal of Ethology - Animals emit predator-elicited calls in response to potential predation threats. These vocalizations induce a variety of anti-predator behaviors in conspecific receivers... 相似文献
3.
A crown-of-thorns starfish control program was conducted at Grub Reef (central Great Barrier Reef) in an area (0.64 km2) which encompassed 53 individual patch reefs. During a two week period, 15 divers injected 3175 starfish with copper sulphate. The program was considered unsuccessful. Although starfish abundance had declined significantly after the control efforts, biological surveys indicated that a relatively large number of starfish remained. The surveys also indicated a general decline in the number of starfish along the reef perimeter, outside the control area. The total cost of the control program was $35 per starfish. These results have important implications for the implementation of future control programs and highlight the need to undertake before and after biological surveys to assess the effectiveness of the control efforts. 相似文献
4.
E. Cortés A.A. Kirk J.A. Goolsby P.J. Moran A.E. Racelis M.A. Marcos-García 《Biocontrol Science and Technology》2011,21(11):1369-1373
Arundo donax L. (Poaceae) is native to Mediterranean Europe and invasive in the Rio Grande Basin of North America. Rhizomes from nine sites in France and Spain infested with a candidate control agent, the armoured scale Rhizaspidiotus donacis (Hemiptera: Diaspididae) weighed 50% less than those from nine sites without scale. 相似文献
5.
Mary H. Moran 《American anthropologist》1998,100(1):235-236
Wives and Warriors: Women and the Military in the United States and Canada. Laurie Weinstein and Christie C. White. eds. Westport, CT: Bergin and Garvey, 1997. 252 pp. 相似文献
6.
Rocío García-Pérez Beatriz Revilla-Nuin Carlos M. Martínez Angel Bernabé-García Alberto Baroja Mazo Pascual Parrilla Paricio 《PloS one》2015,10(12)
Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage hepatectomy technique which can be associated with a hypertrophic stimulus on the future liver remnant (FLR) stronger than other techniques–such as portal vein ligation (PVL). However, the reason of such hypertrophy is still unclear, but it is suggested that liver transection combined with portal vein ligation (ALPPS) during the first stage of this technique may play a key role. The aim of this study is to compare the hypertrophic stimulus on the FLR and the clinical changes associated with both ALPPS and PVL in a rat surgical model. For this purpose, three groups of SD rats were used, namely ALPPS (n = 30), PVL (n = 30) and sham-treated (n = 30). The second stage of ALPPS (hepatectomy of the atrophic lobes), was performed at day 8. Blood and FLR samples were collected at 1, 24, 48 hours, 8 days and 12 weeks after the surgeries. ALPPS provoked a greater degree of hypertrophy of the FLR than the PVL at 48 hours and 8 days (p<0.05). The molecular pattern was also different, with the highest expression of IL-1β at 24h, IL-6 at 8 days, and HGF and TNF-α at 48 hours and 8 days (p<0.05). ALPPS also brought about a mild proliferative stimulus at 12 weeks, with a higher expression of HGF and TGF-β (p<0.05) than PVL. Clinically, ALPPS caused a significant liver damage during the first 48 hours, with a recovery of liver function at day 8. In conclusion, ALPPS seems to induce higher functional hypertrophy on the FLR than PVL at day 8. Such regenerative response seems to be leaded by a complex interaction between pro-mitogenic (IL-6, HGF, TNF-α) and antiproliferative (IL1-β and TGF-β) cytokines. 相似文献
7.
8.
Moran Jonathan A.; Merbach Marlis A.; Livingston Nigel J.; Clarke Charles M.; Booth Webber E. 《Annals of botany》2001,88(2):307-311
Old World pitcher plants (Nepenthes spp., Nepenthaceae) trapand digest invertebrate prey to derive nutrients, primarilynitrogen (N). In the majority of lowland Nepenthes species studiedto date, ants (Hymenoptera, Formicidae) are numerically thedominant prey taxon. Nepenthes albomarginata is unusual in showingan apparent bias towards the capture of termites (Isoptera).We tested the hypothesis that N. albomarginata derives N fromtermite capture, by comparison of foliar stable N isotope abundance( 相似文献
9.
10.