全文获取类型
收费全文 | 255篇 |
免费 | 23篇 |
国内免费 | 18篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 15篇 |
2012年 | 29篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 14篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 8篇 |
2005年 | 15篇 |
2004年 | 4篇 |
2003年 | 13篇 |
2002年 | 5篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 9篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有296条查询结果,搜索用时 31 毫秒
271.
272.
报道了豆科Leguminosae昆仑岩黄耆Hedysarum krassnovii B.Fedtsch.在中国的分布。昆仑岩黄耆与近缘种红花岩黄耆H.multijugum Maxim.形态易混淆,但以其小叶3-9×3-7mm;旗瓣倒卵形,顶端凹陷约2mm深;翼瓣狭披针形;龙骨瓣近半圆形或矩圆形;花萼二唇彤;荚果具1-2节荚等性状易于区分。另外,此二种的物候期、生境及地理分布亦有区别。 相似文献
273.
274.
Background
Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata). The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria.Methodology and Principal Findings
Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae) and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mgg−1 of diet) for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor.Conclusions/Significance
The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mgg−1 antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet. 相似文献275.
Jana Drapalova Petr Kopecky Marketa Bartlova Zdena Lacinova Daniel Novak Pavel Maruna Michal Lips Milos Mraz Jaroslav Lindner Martin Haluzik 《Cryobiology》2014
Changes in endocrine function of adipose tissue during surgery, such as excessive production of proinflammatory cytokines, can significantly alter metabolic response to surgery and worsen its outcomes and prognosis of patients. Therapeutic hypothermia has been used to prevent damage connected with perioperative ischemia and hypoperfusion. The aim of our study was to explore the influence of deep hypothermia on systemic and local inflammation, adipose tissue hypoxia and adipocytokine production. We compared serum concentrations of proinflammatory markers (CRP, IL-6, IL-8, sIL-2R, sTNFRI, PCT) and mRNA expression of selected genes involved in inflammatory reactions (IL-6, TNF-α, MCP-1, MIF) and adaptation to hypoxia and oxidative stress (HIF1-α, MT3, GLUT1, IRS1, GPX1, BCL-2) in subcutaneous and visceral adipose tissue and in isolated adipocytes of patients undergoing cardiosurgical operation with hypothermic period. Deep hypothermia significantly delayed the onset of surgery-related systemic inflammatory response. The relative gene expression of the studied genes was not altered during the hypothermic period, but was significantly changed in six out of ten studied genes (IL-6, MCP-1, TNF-α, HIF1-α, GLUT1, GPX1) at the end of surgery. Our results show that deep hypothermia suppresses the development of systemic inflammatory response, delays the onset of local adipose tissue inflammation and thus may protect against excessive expression of proinflammatory and hypoxia-related factors in patients undergoing elective cardiac surgery procedure. 相似文献
276.
277.
278.
“山水林田湖草沙生命共同体”系统保护与修复是我国生态文明建设的重要内容。明确生命共同体的耦合机制,是科学地进行生态保护和修复工作的关键。针对当前生命共同体耦合机制不清、理论和方法不健全的问题,从耦合的视角出发,在小流域尺度上单一生态系统内部生态要素的耦合、流域尺度上不同生态系统之间的耦合、区域尺度上人与自然的耦合三个方面进行整合,在此基础上探讨了多尺度山水林田湖草沙耦合理论,提出了一般性的山水林田湖草沙耦合理论框架。梳理并比较了当前主要的生态系统模型、景观模型、统计学模型以及复合生态系统的多模型耦合方法,综合提出了一个适用于"山水林田湖草沙生命共同体"耦合研究方法。对进一步完善山水林田湖草沙一体化保护修复提出了建议,包括:一是构建多源信息数据库,推进定量化耦合机制研究;二是开展全生命周期监测与评估,探索适应性治理路径;三是强化多元主体参与,完善协同保护机制。 相似文献
279.
J Dubina S Dobahi L Danes K Kopecky M Kubín B Procházka E Wisingerová 《Journal of hygiene, epidemiology, microbiology, and immunology》1989,33(1):83-89
Serum samples of venous blood of healthy individuals, chosen at random from two areas of the People's Democratic republic of Yemen, were examined for the presence of IgG antibodies against mycobacterial antigen by ELISA. From the district of Aden, the capital (A), there were 214 samples (72% vaccinated by BCG, 108 men and 106 women), other 235 ones originated from mountain area Laudar Muhairas (H) (66% vaccinated, 115 men and 120 women). The overall average of acquired titres was 1:81.4 in area A, and an average of 1:102.2 was recorded in area H. There was no substantial difference in the titres level in men of the two areas (1:86.9 and 1:90 resp.), however, a significant difference was observed in women: 1:75.7 in area A and 1:114.7 in area H. In area A the titres were ranging in all age groups from 1:61 to 1:83 and the differences between age groups and between vaccinated and unvaccinated individuals were not significant. In area H the titres were generally higher (1:72 to 1:164) in the unvaccinated and 1:79 to 1:204 in the vaccinated. The differences in the unvaccinated were not of a statistical importance: in the vaccinated, the titres of the 20-29 years old (1:204.5) substantially differed from the titres obtained in other groups. The differences in titres level between the two studied areas are explained by a different epidemiological situation, namely by a higher tuberculosis infestation of some age groups in area H. 相似文献
280.
J Strauss S S Dobahi L Danes K Kopecky E Svandová 《Journal of hygiene, epidemiology, microbiology, and immunology》1989,33(1):71-74
The HI assay for measles was used to evaluate the sera of 191 children of preschool age (1-6 ys) from five regions of South Yemen: highland, coastal, Vadi Hadramot, the agricultural area Abijan and the capital city Aden. The serum positivity rate was 47.5% in 1-2-year-old children, 75.5% in 3 year-old and 88.5% in 4-6 year-old children. The geometric mean of HI titres was 4.8 log2 in preschool children. An optimal strategy of vaccination against measles in Yemen is discussed. 相似文献