全文获取类型
收费全文 | 560篇 |
免费 | 44篇 |
专业分类
604篇 |
出版年
2024年 | 1篇 |
2023年 | 23篇 |
2022年 | 7篇 |
2021年 | 18篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 31篇 |
2017年 | 29篇 |
2016年 | 43篇 |
2015年 | 27篇 |
2014年 | 40篇 |
2013年 | 90篇 |
2012年 | 41篇 |
2011年 | 39篇 |
2010年 | 47篇 |
2009年 | 29篇 |
2008年 | 18篇 |
2007年 | 7篇 |
2006年 | 21篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 2篇 |
1976年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有604条查询结果,搜索用时 0 毫秒
81.
Emrah Hicazi Aksu Fatih Mehmet Kandemir Serdar Altun Sefa Küçükler Selim Çomaklı Ali Doğan Ömür 《Journal of biochemical and molecular toxicology》2016,30(10):513-520
Cisplatin (CP) treatment causes the damage in male reproductive system. Carvacrol (CARV) is an antioxidant that is naturally found in some plants. We aimed to investigate the effect of CARV on CP‐induced reproductive toxicity in male rats. Eighteen adult male Sprague–Dawley rats were used. The control group (n = 6) was treated orally with physiological saline (PS) daily for 14 days and a single intraperitoneal (IP) PS injection on day 10. The CP group (n = 6) was administered with daily oral PS for 14 days and a single IP injection of 10 mg/kg CP on day 10. The CARV + CP group (n = 6) was treated with daily 75 mg/kg oral CARV for 14 days and a single IP injection of 10 mg/kg CP on day 10. CP treatment caused the damage on some spermatological parameters (motility, live sperm rate, and abnormal sperm rate), increased the oxidative stress, and induced testicular degeneration and apoptosis. However, CARV treatment mitigates CP‐induced reproductive toxicity. 相似文献
82.
83.
In this study, we aimed to detect the proportion of Candida dubliniensis among yeast strains previously identified as C. albicans by using several phenotypic methods and PCR.
For this purpose, we screened 300 strains by using phenotypic tests suggested for the identification of C. dubliniensis in the literature, but we detected high proportion of false-positive reactions. Only two strains (0.6%) were detected as
true C. dubliniensis by PCR and API ID 32C methods. Moreover, these two strains gave the expected results with all the phenotypic tests, including
modified salt tolerance test for C. dubliniensis.
In conclusion, none of the phenotypic methods, except for the modified salt tolerance test, revealed 100% successful results
in discrimination of C. albicans and C. dubliniensis species. However, in the tobacco agar test, the rate of false positivity was as low as 0.6%. We suggest that in the case
of absence of PCR and other automatized identification systems, these two phenotypic tests can be used in routine laboratories
to obtain a presumptive result. 相似文献
84.
The inhibitory effect of Cd on nitrification was investigated in a continuous-flow system with enriched nitrifying bacteria.
The maximum specific ammonium utilization rate and the half-saturation constant were found as 671 mg NH4–N/g VSS day and 0.48 mg/l, respectively. In the case of continuous Cd input at 1 and 2.5 mg/l, nitrification was inhibited
by 30% and 47%, respectively. Inhibition ranged from 20% to 40% and no further increase in inhibition was exhibited in new
runs except at 10 mg/l influent Cd. At 10 mg/l influent Cd, specific ammonium utilization and nitrate production rates were
inhibited by 90%. On the contrary, a serious nitrite accumulation was not observed during this period. When Cd feeding was
stopped, recovery from inhibition was observed after 37 day which was seen by the improvement in ammonium utilization and
nitrate production rates. A shift in microbial population from the initial Nitrosomonas sp. to the Cd-tolerant Nitrosospira sp. was observed in the recovery period from severe Cd inhibition. After the domination of Nitrosospira species, redosing at 10 mg/l and then at 15 mg/l did not affect the performance as before. 相似文献
85.
Tunahan Çakır Margriet M. W. B. Hendriks Johan A. Westerhuis Age K. Smilde 《Metabolomics : Official journal of the Metabolomic Society》2009,5(3):318-329
Reverse engineering of high-throughput omics data to infer underlying biological networks is one of the challenges in systems
biology. However, applications in the field of metabolomics are rather limited. We have focused on a systematic analysis of
metabolic network inference from in silico metabolome data based on statistical similarity measures. Three different data
types based on biological/environmental variability around steady state were analyzed to compare the relative information
content of the data types for inferring the network. Comparing the inference power of different similarity scores indicated
the clear superiority of conditioning or pruning based scores as they have the ability to eliminate indirect interactions.
We also show that a mathematical measure based on the Fisher information matrix gives clues on the information quality of
different data types to better represent the underlying metabolic network topology. Results on several datasets of increasing
complexity consistently show that metabolic variations observed at steady state, the simplest experimental analysis, are already
informative to reveal the connectivity of the underlying metabolic network with a low false-positive rate when proper similarity-score
approaches are employed. For experimental situations this implies that a single organism under slightly varying conditions
may already generate more than enough information to rightly infer networks. Detailed examination of the strengths of interactions
of the underlying metabolic networks demonstrates that the edges that cannot be captured by similarity scores mainly belong
to metabolites connected with weak interaction strength. 相似文献
86.
The ability of theRhizobium ciceri, to produce extracellular polysaccharides (EPS) was investigated. Tested carbon and nitrogen sources influced EPS synthesis whenR. ciceri Rc5 was grown in a chemically defined medium. Mannitol was the most efficient carbon source among the six sources tested (sucrose, glucose, arabinose, fructose, xylose and rhamnose) and sodium nitrate was the most efficient nitrogen source among the two tested (ammonium sulphate and glycine). High amounts of EPS (1182.0 and 1015 μg ml−1, respectively) were produced by the Rc5 strain in mannitol and sodium nitrate respectively, which was accompanied by a great increase in the production compared to the control. 相似文献
87.
Demet Çetin 《Soil & Sediment Contamination》2009,18(3):345-353
Poly-3-hydroxybutyrate (PHB) film pieces were degraded by sulfate reducing Desulfotomaculum sp. incubated under anaerobic laboratory conditions. Degradation started with adherence of the microbial cells and followed by formation of black colonies on the film surface. Scanning electron microscopic (SEM) observations revealed the presence of bacteria and formation of small holes on the film. After 60 days of incubation at 30°C, 10 % weight loss in polymer and 13 % sulfate reduction in the medium was observed. According to gel permeation chromatography (GPC) analysis, the molecular weight of the PHB decreased after 30 days and did not decrease further at a more extended incubation period. Loss of weight of PHB does not seem to be correlated with molecular weight decrease. 相似文献
88.
Zeynep Petek Çakar Professor 《Biotechnology journal》2009,4(7):992-1002
This review discusses metabolic engineering research with an emphasis on evolutionary (whole cell and protein) engineering, which is an inverse metabolic engineering approach. For each section on metabolic, inverse metabolic and evolutionary engineering research, a general review of the major global studies in the literature is made and research examples from Turkey are given and discussed. It is expected that with the rapid development in systems biology and the novel powerful analytical technologies to identify the genetic basis of cellular phenotypes, metabolic and evolutionary engineering research will become widespread and increasingly important in Turkey, following global scientific trends. 相似文献
89.
M. Kırça N. Oğuz A. Çetin F. Uzuner 《Journal of receptor and signal transduction research》2017,37(2):167-173
Hyperuricemia and angiotensin II (Ang II) may have a pathogenetic role in the development of hypertension and atherosclerosis as well as cardiovascular disease (CVD) and its prognosis. The purpose of this study was to investigate whether uric acid can induce proliferative pathways of vascular smooth muscle cell (VSMC) that are thought to be responsible for the development of CVD. The phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), p44/42 mitogen-activated protein kinase (p44/42 MAPK) and platelet-derived growth factor receptor β (PDGFRβ) was measured by Elisa and Western blot techniques to determine the activation of proliferative pathways in primary cultured VSMCs from rat aorta. Results demonstrated that uric acid can stimulate p38 MAPK, p44/42 MAPK and PDGFRβ phosphorylation in a time- and concentration-dependent manner. Furthermore, treatment of VSMCs with the angiotensin II type I receptor (AT1R) inhibitor losartan suppressed p38 MAPK and p44/42 MAPK induction by uric acid. The stimulatory effect of uric acid on p38 MAPK was higher compared to that of Ang II. The results of this study show for the first time that uric acid-induced PDGFRβ phosphorylation plays a crucial role in the development of CVDs and that elevated uric acid levels could be a potential therapeutical target in CVD patients. 相似文献
90.
The transportation of hazardous materials assumes a fundamental importance, especially in urban areas, in order to identify possible alternative routes and to choose the route with minimum risk. Therefore, considering minimization risk rather than minimization distance to prevent a potential danger being transformed into a real event is necessary. In this article , a geographic information system (GIS)–based solution approach is developed to quantify the factors on each link in the network that contribute to a possible route. Based on the origin and destination of each shipment, the risks associated with the routes that minimize (1) the transport distance, (2) the population exposure, (3) the probability of an incident, and (4) the emergency response are evaluated. Proposed risk models are applied to fuel-oil transportation problem between resource point and 78 gasoline stations through the road network of Gaziantep city center. Results show that the proposed framework can contribute to the thought processes of policy-makers and carriers when they evaluate possible routes in order to minimize damage for transporting fuel oil. 相似文献