全文获取类型
收费全文 | 563篇 |
免费 | 19篇 |
出版年
2023年 | 1篇 |
2022年 | 11篇 |
2021年 | 16篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 25篇 |
2017年 | 12篇 |
2016年 | 16篇 |
2015年 | 26篇 |
2014年 | 45篇 |
2013年 | 44篇 |
2012年 | 54篇 |
2011年 | 65篇 |
2010年 | 28篇 |
2009年 | 20篇 |
2008年 | 40篇 |
2007年 | 27篇 |
2006年 | 41篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有582条查询结果,搜索用时 15 毫秒
11.
Janhvi Pandey Sukhmal Chand Shweta Chaurasiya Raj Kumari D.D. Patra R.K. Verma 《Soil & Sediment Contamination》2019,28(4):395-410
A field experiment was conducted to observe the effect of TS amendments on soil enzymes and phytoremediation potential of two economically important cultivars of geranium. Different doses of TS were applied in soil to examine threshold limit of HMs where geranium cultivars can be grown successfully in contaminated sites. Treatment variation significantly affected pH, EC, OC, N, P, K and HM content in soil after 50 days of incubation. After harvest, both cultivars were examined to assess the impact of various treatments on their fresh herb, dry matter, essential oil yield and HM accumulation. C/G ratio close to 1 was observed at 50 tha?1 sludge treatment in both cultivars. Urease and β-glucosidase activities in soil were maximum at 50 tha?1 whereas dehydrogenase and phosphatase activities were maximum at 100 tha?1 in both cultivars. β-glucosidase, acid and alkaline phosphatase, urease and dehydrogenase activities were relatively high after 85 days over 45 days in both cultivars. Maximum metal uptake was found in roots of cv. Bourbon followed by leaves. Geranium was observed to be a good candidate for phytoremediation as it mitigates metal toxicity by root absorption and cv. Bourbon is better candidate for the same. 相似文献
12.
The most common inflammatory disease of the airways is asthma among children affecting around 235 million people worldwide. 5-Lipoxygenase (5-LOX) is a crucial enzyme which helps in the conversion of arachidonic acid (AA) to leukotrienes (LTs), the lipid mediators. It is associated with several inflammation related disorders such as asthma, allergy, and atherosclerosis. Therefore, it is considered as a promising target against inflammation and asthma. Currently, the only drug against 5-LOX which is available is Zileuton, while a few inhibitors are in clinical trial stages such as Atreleuton and Setileuton. So, there is a dire requirement in the area of progress of novel 5-LOX inhibitors which necessitates an understanding of their structure activity relationship and mode of action. In this review, novel 5-LOX inhibitors reported so far, their structural design, SAR and developmental strategies along with clinical updates are discussed over the last two decades. 相似文献
13.
Yadav Shweta Gupta Ekta Patel Anju Srivastava Suchi Mishra Virendra Kumar Singh Poonam C. Srivastava Pankaj Kumar Barik Saroj Kanta 《Reviews in Environmental Science and Biotechnology》2022,21(3):771-798
Reviews in Environmental Science and Bio/Technology - In the past few decades, pollution from microplastics has emerged as an important issue on a global scale. These plastic particles are mainly... 相似文献
14.
Singh Shweta Hans Sandeep Ahmad Aijaz Fatima Zeeshan Hameed Saif 《International microbiology》2022,25(4):769-779
International Microbiology - Infections caused by Candida albicans are rising due to increment in drug resistance and a limited arsenal of conventional antifungal drugs. Thus, elucidating the novel... 相似文献
15.
16.
Tom Z. Yuan Pankaj Garg Linya Wang Jordan R. Willis Eric Kwan Ana G Lujan Hernandez Emily Tuscano Emily N. Sever Erica Keane Cinque Soto Eric M. Mucker Mallorie E. Fouch Edgar Davidson Benjamin J. Doranz Shweta Kailasan M. Javad Aman Haoyang Li Jay W. Hooper Erica Ollmann Saphire James E. Crowe Qiang Liu Fumiko Axelrod Aaron K. Sato 《MABS-AUSTIN》2022,14(1)
17.
A convenient and biogenetic type synthesis of few naturally occurring chromeno dihydrochalcones and their in vitro antileishmanial activity 总被引:2,自引:0,他引:2
2',2'-Dimethyl chromeno dihydrochalcones are very rare in nature as plant secondary metabolites. Recently we have reported three such compounds from the plant Crotalaria ramosissima. Chromeno dihydrochalcones contain a 2',2'-dimethyl benzopyran system, which are frequently encountered in many natural products and exhibit a variety of biological activities. We here report the strategy to conveniently synthesize naturally occurring chromeno dihydrochalcones by biogenetic type pyridine or Amberlyst-15 catalyzed chromenylation of dihydrochalcones and in vitro antileishmanial activity of chromeno dihydrochalcones and their intermediates. 相似文献
18.
Howell GJ Herbert SP Smith JM Mittar S Ewan LC Mohammed M Hunter AR Simpson N Turner AJ Zachary I Walker JH Ponnambalam S 《Molecular membrane biology》2004,21(6):413-421
Secretory granules called Weibel-Palade bodies (WPBs) containing Von Willebrand factor (VWF) are characteristic of the mammalian endothelium. We hypothesized that vascular-specific antigens such as VWF are linked to endothelial identity and proliferation in vitro. To test this idea, the cellular accumulation of VWF in WPBs was monitored as a function of cell proliferation, confluence and passage number in human umbilical vein endothelial cells (HUVECs). We found that as passage number increased the percentage of cells containing VWF in WPBs was reduced significantly, whilst the protein was still detected within the secretory pathway at all times. However, the endothelial-specific marker protein, PECAM-1, is present on all cells even when WPBs are absent, indicating partial maintenance of endothelial identity. Biochemical studies show that a significant pool of immature pro-VWF can be detected in sub-confluent HUVECs; however, a larger pool of mature, processed VWF is detected in confluent cells. Newly synthesized VWF must thus be differentially sorted and packaged along the secretory pathway in semi-confluent versus confluent endothelial cells. Our studies thus show that WPB formation is linked to the formation of a confluent endothelial monolayer. 相似文献
19.
Although immune responses following soft-tissue trauma-hemorrhage are markedly different in young (6-8 weeks) and aged (18-20 months) mice, it remains unknown if there are any differences in immune responses in middle-aged and young mice following bone fracture, soft-tissue trauma-hemorrhage (Fx-TH). To study this, young (6-8 weeks) and middle-aged (approximately 12 months) C3H/HeN male mice were subjected to sham operation or Fx-TH followed by resuscitation with Ringer's lactate. The mice were sacrificed 2 h thereafter and splenocytes, bone marrow cells (BM) and Kupffer cells (KC) were harvested, purified and stimulated with ConA (for splenocytes) or LPS (for BM and KC) in vitro. Splenocyte release of Th1 (IL-2 and IFN-gamma) cytokines was decreased and Th2 (IL-4 and IL-10) cytokine release was increased following Fx-TH in both young and middle-aged mice. However, the decrease in IL-2 and increase in IL-10 were significantly more in middle-aged mice compared to young mice (p < 0.05). Furthermore, splenocyte proliferation was decreased more in middle-aged mice compared to young mice following Fx-TH (p < 0.05). Additionally, TNF-alpha production was more in BM from middle-aged compared to BM from young mice after Fx-TH (p < 0.05). The production of IL-6 and IL-10 was also significantly higher in KC from middle-aged mice compared to young ones following Fx-TH. These results suggest that at middle age, the immune responses to Fx-TH are significantly different from those observed in young mice in different compartments of the body. Although the mechanism of the difference in various compartments in middle-aged vs. young mice following Fx-TH remains unknown, the decreased IL-2 production along with other altered T cell and macrophage functions may contribute to an increased susceptibility to sepsis in middle-aged vs. young individuals. 相似文献
20.
Adenylyl cyclase G (ACG) is activated by high osmolality and mediates inhibition of spore germination by this stress factor. The catalytic domains of all eukaryote cyclases are active as dimers and dimerization often mediates activation. To investigate the role of dimerization in ACG activation, we coexpressed ACG with an ACG construct that lacked the catalytic domain (ACGDeltacat) and was driven by a UV-inducible promoter. After UV induction of ACGDeltacat, cAMP production by ACG was strongly inhibited, but osmostimulation was not reduced. Size fractionation of native ACG showed that dimers were formed between ACG molecules and between ACG and ACGDeltacat. However, high osmolality did not alter the dimer/monomer ratio. This indicates that ACG activity requires dimerization via a region outside the catalytic domain but that dimer formation does not mediate activation by high osmolality. To establish whether ACG required auxiliary sensors for osmostimulation, we expressed ACG cDNA in a yeast adenylyl cyclase null mutant. In yeast, cAMP production by ACG was similarly activated by high osmolality as in Dictyostelium. This strongly suggests that the ACG osmosensor is intramolecular, which would define ACG as the first characterized primary osmosensor in eukaryotes. 相似文献