全文获取类型
收费全文 | 1450篇 |
免费 | 82篇 |
国内免费 | 7篇 |
专业分类
1539篇 |
出版年
2024年 | 2篇 |
2023年 | 21篇 |
2022年 | 49篇 |
2021年 | 57篇 |
2020年 | 56篇 |
2019年 | 74篇 |
2018年 | 63篇 |
2017年 | 50篇 |
2016年 | 64篇 |
2015年 | 83篇 |
2014年 | 89篇 |
2013年 | 127篇 |
2012年 | 93篇 |
2011年 | 111篇 |
2010年 | 66篇 |
2009年 | 61篇 |
2008年 | 47篇 |
2007年 | 48篇 |
2006年 | 42篇 |
2005年 | 41篇 |
2004年 | 39篇 |
2003年 | 24篇 |
2002年 | 22篇 |
2001年 | 2篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 12篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 22篇 |
1987年 | 17篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 14篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1975年 | 5篇 |
1957年 | 1篇 |
1956年 | 2篇 |
排序方式: 共有1539条查询结果,搜索用时 0 毫秒
91.
92.
93.
Amirhossein Sahebkar Mahdi Hatamipour Sayed Abbas Tabatabaei 《Journal of cellular biochemistry》2019,120(6):9455-9459
Disruption of macrophage autophagy is a major contributor to macrophage dysfunction and subsequent inflammation leading to atherosclerosis. Trehalose is a natural disaccharide that is able to induce macrophage autophagy-lysosomal biogenesis and reduce inflammation. Here, we studied the efficacy of intravenous trehalose administration in reducing atherosclerotic plaque burden in high-cholesterol-fed rabbits. Adult male New Zealand white Rabbits were fed with a high-fat diet containing 1% cholesterol for 8 weeks followed by a cholesterol-free diet for the next 4 weeks. In the latter 4-week phase of the cholesterol-free diet, one group received intravenous trehalose solution at a dose of 350 mg/kg, three times per week. In the control group, an equivalent volume of PBS (3 mL) was administered with the same protocol. At the end of the 12th week of the study, all rabbits were anesthetized and aortic arch sections were collected followed by hematoxylin and eosin staining and assessment of plaque grading. Fasting serum lipids were also measured using routine enzymatic methods. At the end of the 12th week, there were no significant differences in the body weight and blood lipids between the control- and trehalose-treated groups. Intravenous trehalose administration significantly attenuated atherosclerotic plaque development as revealed by reduced plaque grading ( P = 0.048) and intima/media thickness ratio ( P = 0.017). Intimal thickening was also found to be reduced in the trehalose versus control group, though this reduction did not reach statistical significance. The present study provided evidence as to the efficacy of short-term intravenous trehalose administration in regressing atherosclerotic plaque in high-fat-fed rabbits. 相似文献
94.
Shirin Kouhpayeh Zahra Hejazi Maryam Boshtam Mina Mirian Ilnaz Rahimmanesh Leila Darzi Abbas Rezaei Laleh Shariati Hossein Khanahmad 《Journal of cellular biochemistry》2019,120(9):16264-16272
One of the most important molecules for multiple sclerosis pathogenesis is α4 integrin, which is responsible for autoreactive leukocytes migration into the brain. The monoclonal antibody, natalizumab, was introduced to market for blocking the extravasation of autoreactive leukocytes via inhibition of α4 integrin. However, the disadvantages of antibodies provided a suitable background for other agents to be replaced with antibodies. Considering the profound advantages of aptamers over antibodies, aptamer isolation against α4 integrin was intended in the current study. The α4 integrin-specific aptamers were selected using cell-systematic evolution of ligands by exponential enrichment (SELEX) method with human embryonic kidney (HEK)-293T overexpressing α4 integrin and HEK-293T as target and control cells, respectively. Evaluation of selected aptamer was performed through flow cytometric analysis. The selected clones were then sequenced and analyzed for any possible secondary structure and affinity. The results of this study led to isolation of 13 different single-stranded DNA clones in 11 rounds of selection which were categorized to three clusters based on common structural motifs and the equilibrium dissociation constant (K d) of the most stable structure was calculated. The evaluation of SELEX progress showed growth in aptamer affinity with increasing of the number of cycles. Taken together, the findings of this study demonstrated the isolation of α4-specific single-stranded DNA aptamers with suitable affinity for ligand, which can further be replaced with natalizumab. 相似文献
95.
96.
Parya Jangipour Afshar Abbas Bahrampour Armita Shahesmaeili 《PLoS neglected tropical diseases》2022,16(4)
IntroductionCutaneous leishmaniasis (CL) is currently a health problem in several parts of Iran, particularly Kerman. This study was conducted to determine the incidence and trend of CL in Kerman during 2014–2020 and its forecast up to 2023. The effects of meteorological variables on incidence was also evaluated.Materials and methods4993 definite cases of CL recorded from January 2014 to December 2020 by the Vice-Chancellor for Health at Kerman University of Medical Sciences were entered. Meteorological variables were obtained from the national meteorological site. The time series SARIMA methods were used to evaluate the effects of meteorological variables on CL.ResultsMonthly rainfall at the lag 0 (β = -0.507, 95% confidence interval:-0.955,-0.058) and monthly sunny hours at the lag 0 (β = -0.214, 95% confidence interval:-0.308,-0.119) negatively associated with the incidence of CL. Based on the Akaike information criterion (AIC) the multivariable model (AIC = 613) was more suitable than univariable model (AIC = 690.66) to estimate the trend and forecast the incidence up to 36 months.ConclusionThe decreasing pattern of CL in Kerman province highlights the success of preventive, diagnostic and therapeutic interventions during the recent years. However, due to endemicity of disease, extension and continuation of such interventions especially before and during the time periods with higher incidence is essential. 相似文献
97.
Xin Hu Bili Zhang Xi Zheng Haoyan Ji Kun Feng Xiaosong Hu Isma Gul Muhammad Nadeem Abbas Hongjuan Cui Yong Zhu 《Current issues in molecular biology》2022,44(2):777
Eicosanoids are crucial downstream signals in the insect immune responses. Phospholipase A2 (PLA2) catalyzes phospholipids, the initial step in eicosanoid biosynthesis. In mammals, the biological roles of Ca2+-independent Phospholipase A2 (iPLA2) have been extensively studied; however, only a few studies have attempted to explore iPLA2 functions in insects. In this study, we identified two iPLA2 genes (designated as BmiPLA2A and BmiPLA2B) in the silkworm, Bombyx mori. BmiPLA2A had a 2427 base pair (bp) open reading frame (ORF) that coded for a protein with 808 amino acids. In contrast, BmiPLA2B had a 1731 bp ORF that coded for a protein with 576 amino acids. Domain analysis revealed that BmiPLA2A had six ankyrin repeat domains, but BmiPLA2B lacks these domains. BmiPLA2A and BmiPLA2B were transcribed widely in various tissues and developmental stages with different expression patterns. The administration of 20-hydroxyecdysone increased their expression levels in the epidermis and hemocytes. Furthermore, challenged with virus, fungus, Gram-negative bacteria, and Gram-positive bacteria induced the expression of BmiPLA2A and BmiPLA2B with variable degrees along with different time points. Our findings imply that BmiPLA2A and BmiPLA2B may have important biological roles in the development and innate immunity of B. mori. 相似文献
98.
Abbas HK Cartwright RD Xie W Mirocha CJ Richard JL Dvorak TJ Sciumbato GL Shier WT 《Mycopathologia》1999,147(2):97-104
Twenty samples of unpolished (rough) rice collected in Arkansas and Texas during the 1995 harvesting season from fields exhibiting
Fusarium sheath rot disease or panicle blight were previously shown to include 8 samples positive for fumonisin B1(FB1) in the range 2.2–5.2 ppm, and moniliformin (MON), but no beauvericin (BEA), deoxynivalenol, its derivatives or zearalenone
were detected. Fifteen cultures of F. proliferatum were established from the 20 rough rice samples. Single spore isolates of each culture were grown on rice and tested for
the production of fumonisins (FB1, FB2, FB3, etc.), MON and BEA. All 15 isolates produced FB1, FB2, MON and BEA in culture on rice. No deoxynivalenol, its derivatives orzearalenone were detected. Seven cultures produced
FB1 at >50ppm (range 80–230 ppm), with therest producing FB1 in the range 14–43 ppm.FB2 was produced in the range 5–47 ppm, and those cultures which produced the most FB1 also produced the most FB2. Of the 15 cultures producing MON, 11 produced it at >100 ppm in the range 188–6018 ppm, with the rest producing in the range
7–64 ppm. BEA was produced in the range 109–1350 ppm. Other derivatives of fumonisins, including FA1, FA2 and partially hydrolyzed FB1, as well asseveral unknown metabolites including a compound with MW 414, were identified in culture extracts by continuous
flow fast atom bombardment with ion spraymass spectrometry (CF/FAB/MS). Further study is needed to identify the factors that
control production of FB1, MON and BEA by F.proliferatu in culture and in field samples.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
99.
Almasirad A Tabatabai SA Faizi M Kebriaeezadeh A Mehrabi N Dalvandi A Shafiee A 《Bioorganic & medicinal chemistry letters》2004,14(24):191-6059
A series of new 2-substituted-5-[2-(2-fluorophenoxy)phenyl]-1,3,4-oxadiazoles has been synthesized and screened for their anticonvulsant activities. Compound 3 shows considerable anticonvulsant activity both in PTZ and MES models. It seems that this effect is mediated by benzodiazepine receptors and other unknown mechanism, respectively. 相似文献
100.