全文获取类型
收费全文 | 461篇 |
免费 | 56篇 |
国内免费 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 13篇 |
2022年 | 16篇 |
2021年 | 20篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 20篇 |
2017年 | 22篇 |
2016年 | 19篇 |
2015年 | 15篇 |
2014年 | 24篇 |
2013年 | 36篇 |
2012年 | 25篇 |
2011年 | 27篇 |
2010年 | 26篇 |
2009年 | 16篇 |
2008年 | 23篇 |
2007年 | 30篇 |
2006年 | 24篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有539条查询结果,搜索用时 281 毫秒
51.
52.
53.
54.
Chao Fang Katie K. Lee Raymond Nietupski Robert H. Bates Raquel Fernandez-Menendez Eva Maria Lopez-Roman Laura Guijarro-Lopez Yunxing Yin Zuozhong Peng James E. Gomez Stewart Fisher David Barros-Aguirre Brian K. Hubbard Michael H. Serrano-Wu Deborah T. Hung 《Bioorganic & medicinal chemistry letters》2018,28(22):3529-3533
Previous work established a coumarin scaffold as a starting point for inhibition of Mycobacterium tuberculosis (Mtb) FadD32 enzymatic activity. After further profiling of the coumarin inhibitor 4 revealed chemical instability, we discovered that a quinoline ring circumvented this instability and had the advantage of offering additional substitution vectors to further optimize. Ensuing SAR studies gave rise to quinoline-2-carboxamides with potent anti-tubercular activity. Further optimization of ADME/PK properties culminated in 21b that exhibited compelling in vivo efficacy in a mouse model of Mtb infection. 相似文献
55.
Natasha Janke Olaf Berke Eyal Klement D.T. Tyler Flockhart Jason Coe Shane Bateman 《Journal of applied animal welfare science : JAAWS》2018,21(3):283-294
In recent years, there has been a growing concern regarding populations of cats who are homeless. Shelters are constantly overwhelmed by the influx of cats without caregivers and are seeking solutions to enhance positive outcomes for them. In 2014, the Guelph Humane Society implemented a population management program to expedite the movement of cats through the shelter by decreasing the average nonhuman animal’s length of stay using scheduled intakes to control for overcrowding and by implementing strategies to increase adoption rates. This study investigated the time trends in admission rates of cats to the Guelph Humane Society to assess the effectiveness of a population management program called Capacity for Care using a generalized linear autoregressive moving average model. From January 2011 to December 2015, a total of 3295 live cats were admitted to the Guelph Humane Society. When the analysis was adjusted to account for admissions of kittens, there was a significant reduction in admissions for adult cats (p < .01) following the introduction of the population management program. The results also showed a strong seasonal peak in total admissions during the summer months. 相似文献
56.
Joanna Kamińska Olga M. Koper Edyta Siedlecka-Czykier Joanna Matowicka-Karna Jerzy Bychowski Halina Kemona 《Saudi Journal of Biological Sciences》2018,25(7):1263-1271
Introduction
Thrombotic and inflammatory mechanisms are involved in the pathophysiology of acute coronary syndrome (ACS). The aim of the study was the evaluation of inflammation (white blood cells count/WBC, C-reactive protein/CRP, interleukin-6/IL-6) and platelet (platelet count/PLT, mean platelet volume/MPV, large platelet/LPLT, beta-thromboglobulin/β-TG) biomarkers in the groups of ACS patients depending on the severity of signs and symptoms and compared to controls without coronary artery disease.Materials and methods
The study group included 93 patients categorized into 3 subgroups depending on the severity of signs and symptoms of ACS. PLT, MPV, LPLT, and WBC were determined on hematological analyzer, IL-6 and β-TG were measured using the ELISA method.Results
In the whole group of ACS patients WBC, CRP, IL-6, MPV, and β-TG were significantly higher as compared to controls. Analyzing the inflammation and platelet biomarkers depending on the severity of signs and symptoms in comparison to controls, statistically significant differences for above-mentioned parameters were also found. There were no significant differences between the advancement of coronary artery changes and inflammation as well as platelet parameters, except for CRP concentrations. The AUCs for all inflammation parameters tested were similar, however the highest AUCs showed WBC and CRP. Among platelet parameters the highest AUC revealed β-TG.Conclusion
Markers of inflammation and platelet activation may be associated to myocardial ischemia and myocardial injury. WBC, CRP and IL-6 as inflammation parameters and MPV and β-TG as platelet biomarkers may be useful indicators of the presence of coronary artery disease. 相似文献57.
A dynamic analysis of viral load, T lymphocyte subsets and main biochemical indexes before and after prevention of mother to child transmission (PMTCT) in HIV/AIDS
下载免费PDF全文
![点击此处可从《Asia-Pacific Journal of Blood Types and Genes》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Guosheng Su Yesheng Wei Lihua Qin Lida Mo 《Asia-Pacific Journal of Blood Types and Genes》2018,2(4):223-231
This study aims to investigate changes in viral load, T lymphocyte subsets and other main biochemical indexes of HIV/AIDS in the prevention of mother to child transmission (PMTCT). In this study, 152 pregnant women with HIV/AIDS enrolled into our hospital from January 2013 to June 2015 were chosen as objects. Changes in viral load, T lymphocyte subsets and other main biochemical indexes of HIV/AIDS were tested and compared before and after 3 months of PMTCT and in neonatals one week after birth. The CD4/CD8 examination result, and difference in CD4 before and after prevention (in the newborns after a week) was statistically significant (P < 0.05), and the rest showed no statistical significance. For the dynamic analysis of main biochemical test results: K+, Na+, Cl-, BG, OS, BUN, BUN/Cr, UA,TDIL, DBIL, TP, ALB, CK, LDH, HDL, LDL and other indexes before and after prevention attained statistical significances (P < 0.05 or above). The same sample in the three groups was detected by repeated analysis of variance, K+, Na+, Cl-, BG, OS, BUN/Cr, UA, DBI L, ALB, CK, LDH, HDL, LDL and other indexes also showing P at less than 0.05 or above, among which K+, Cl-, CK, LDL showed homogeneity of variance, while Na+, BG, OS, BUN/Cr, UA, DBIL, ALB, LDH, HDL showed unequal homogeneity of variance. The study suggests that the dynamic analysis of viral load, T lymphocyte subsets and main biochemical indexes before and after PMTCT in HIV/AIDS are important means to evaluate the dose and treatment of antiretroviral drugs. Monitoring of above indexes is helpful to judge and analyze the condition of the maternal body at various stages, so antiviral drug treatment can be adjusted. 相似文献
58.
Advances in soil microbial ecology and the biodiversity 总被引:3,自引:0,他引:3
Tsutomu Hattori Hisayuki Mitsui Hideki Haga Norio Wakao Shuichi Shikano Krystyna Gorlach Yasuhiro Kasahara Adel El-Beltagy Reiko Hattori 《Antonie van Leeuwenhoek》1997,72(1):21-28
Recent studies on the colony formation of soil bacteria opened the way to categorize soil bacteria into colony forming curve (CFC) groups of different growth rates. A bacterial culture collection comprising organisms from every CFC group is called an ecocollection. Outlines of ECs of paddy soil 1992 and grassland soil 1987 and 1992 were described. Phylogenetic studies by 16S rDNA sequencing showed a great diversity of culture strains of the ecocollections (EC). A set of alternative concepts was proposed; the active and the quiescent forms of bacterial cells in soil. The former is able to be cultivated and thus counted by the plate method, while the latter is not unless it transforms into the former. Based on the results several points required for extensive cataloguing of soil bacteria were noted. 相似文献
59.
1. Bacterial populations associated with fish have previously been documented to be crucial for the production of chemical signals governing the interactions between predator fish and zooplankton prey. 2. In this study, we investigated the roles of fish and mucus‐dwelling bacteria in kairomone production by conducting two sets of experiments related to elimination of bacteria with antibiotics and using fish mucus in bioassays of Daphnia pulex’s diel vertical migration. 3. Daphnia’s migratory response to the antibiotic‐treated fish was about half the strength of the response to the fish cue treatment. Furthermore, when the same antibiotic‐treated fish were removed from the antibiotic‐containing water and transferred into control water for 24 and 48 h, the extent of D. pulex’s migration depended on the length of the incubation period, apparently corresponding to the regeneration of bacterial colonies associated with mucus. The migration pattern observed in the 24 h treatment was similar to that of antibiotic‐treated fish. On the other hand, a pronounced migration occurred in the 48 h following antibiotic treatment; here, we found a higher density of fish surface dwelling bacteria than at the start of the experiment. 4. In the experiment involving fish mucus, the mucus‐enriched control water induced a weak response similar to antibiotic‐treated fish. 5. On the basis of the results from the two experiments, we suggest that both fish and fish mucus‐dwelling bacteria interact in the release of kairomone in ecologically relevant quantities. 相似文献
60.
Henrik Barner Rasmussen Onesmas Kahindi Fritz Vollrath Iain Douglas-Hamilton 《African Journal of Ecology》2005,43(4):312-319
In this paper, we present a new method for estimating elephant densities by counting elephant wells and dung boli within dry seasonal flooding rivers. A combination of aerial and ground counts of elephant wells and dung boli in the Ewaso Ngiro River were related to elephant numbers, obtained from an on‐going monitoring program of individually identified elephants in Samburu and Buffalo Spring National Reserves, Kenya. The total number of elephant observations was highly correlated with both densities of wells and dung boli at a spatial resolution of 4‐km river‐section. This indicates that both wells and droppings can be used for estimating relative densities at such spatial resolution. The method can be used as a quick and reliable way of estimating relative elephant densities in semiarid regions but is sensitive to differences in the time when different parts of the river dry out and will be unreliable in areas with secondary un‐censused water sources. A short 4‐week period between the river dry out and the count is recommended, because of an error induced by a level of well reuse and the difficulties in counting areas of high well densities from the air. 相似文献