全文获取类型
收费全文 | 2072篇 |
免费 | 116篇 |
国内免费 | 103篇 |
出版年
2024年 | 4篇 |
2023年 | 10篇 |
2022年 | 63篇 |
2021年 | 111篇 |
2020年 | 69篇 |
2019年 | 89篇 |
2018年 | 68篇 |
2017年 | 58篇 |
2016年 | 88篇 |
2015年 | 156篇 |
2014年 | 152篇 |
2013年 | 173篇 |
2012年 | 213篇 |
2011年 | 182篇 |
2010年 | 104篇 |
2009年 | 93篇 |
2008年 | 130篇 |
2007年 | 82篇 |
2006年 | 95篇 |
2005年 | 77篇 |
2004年 | 77篇 |
2003年 | 48篇 |
2002年 | 51篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 18篇 |
1998年 | 15篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有2291条查询结果,搜索用时 187 毫秒
61.
62.
Weiliang Qi Yao Tang Wei Zhu Daiyan Li Chengdou Diao Lili Xu Jian Zeng Yi Wang Xing Fan Lina Sha Haiqin Zhang Youliang Zheng Yonghong Zhou Houyang Kang 《Planta》2016,244(2):405-416
Main conclusion
A new wheat-rye 1BL?1RS translocation line, with the characteristics of superior stripe rust resistance and high thousand-kernel weight and grain number per spike, was developed and identified from progenies of wheat-rye- Psathyrostachys huashanica trigeneric hybrids.Abstract
The wheat-rye 1BL?1RS translocation line from Petkus rye has contributed substantially to the world wheat production. However, due to extensive growing of cultivars with disease resistance genes from short arm of rye chromosome 1R and coevolution of pathogen virulence and host resistance, these cultivars successively lost resistance to pathogens. In this study, a new wheat-rye line K13-868, derived from the progenies of wheat-rye-Psathyrostachys huashanica trigeneric hybrids, was identified and analyzed using fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH), acid polyacrylamide gel electrophoresis (A-PAGE), and molecular markers. Cytological studies indicated that the mean chromosome configuration of K13-868 at meiosis was 2n = 42 = 0.14 I + 18.78 II (ring) + 2.15 II (rod). Sequential FISH and GISH results demonstrated that K13-868 was a compensating wheat-rye 1BL?1RS Robertsonian translocation line. Acid PAGE analysis revealed that clear specific bands of rye 1RS were expressed in K13-868. Simple sequence repeat (SSR) and rye 1RS-specific markers ω-sec-p1/ω-sec-p2 and O-SEC5′-A/O-SEC3′-R suggested that the 1BS arm of wheat had been substituted by the 1RS arm of rye. At the seedling and adult growth stage, compared with its recurrent wheat parent SM51 and six other wheat cultivars containing the 1RS arm in southwestern China, K13-868 showed high levels of resistance to stripe rust (Puccinia striiformis f. sp. tritici, Pst) pathogens prevalent in China, which are virulent to Yr10 and Yr24/Yr26. In addition, K13-868 expresses higher thousand-kernel weight and more grain number per spike than these controls in two growing seasons, suggesting that this line may carry yield-related genes of rye. This translocation line, with significant characteristics of resistance to stripe rust and high thousand-kernel weight and grain number per spike, could be utilized as a valuable germplasm for wheat improvement.63.
64.
65.
66.
Mariona Guitart‐Mampel Diana L. Juarez‐Flores Lina Youssef Constanza Moren Laura Garcia‐Otero Vicente Roca‐Agujetas Marc Catalan‐Garcia Ingrid Gonzalez‐Casacuberta Ester Tobias Jos C. Milisenda Josep M. Grau Ftima Crispi Eduard Gratacos Francesc Cardellach Glria Garrabou 《Journal of cellular and molecular medicine》2019,23(6):3962-3973
Intrauterine growth restriction (IUGR) is an obstetric complication characterised by placental insufficiency and secondary cardiovascular remodelling that can lead to cardiomyopathy in adulthood. Despite its aetiology and potential therapeutics are poorly understood, bioenergetic deficits have been demonstrated in adverse foetal and cardiac development. We aimed to evaluate the role of mitochondria in human pregnancies with IUGR. In a single‐site, cross‐sectional and observational study, we included placenta and maternal peripheral and neonatal cord blood mononuclear cells (PBMC and CBMC) from 14 IUGR and 22 control pregnancies. The following mitochondrial measurements were assessed: enzymatic activities of mitochondrial respiratory chain (MRC) complexes I, II, IV, I + III and II + III, oxygen consumption (cell and complex I‐stimulated respiration), mitochondrial content (citrate synthase [CS] activity and mitochondrial DNA copy number), total ATP levels and lipid peroxidation. Sirtuin3 expression was evaluated as a potential regulator of bioenergetic imbalance. Intrauterine growth restriction placental tissue showed a significant decrease of MRC CI enzymatic activity (P < 0.05) and CI‐stimulated oxygen consumption (P < 0.05) accompanied by a significant increase of Sirtuin3/β‐actin protein levels (P < 0.05). Maternal PBMC and neonatal CBMC from IUGR patients presented a not significant decrease in oxygen consumption (cell and CI‐stimulated respiration) and MRC enzymatic activities (CII and CIV). Moreover, CS activity was significantly reduced in IUGR new‐borns (P < 0.05). Total ATP levels and lipid peroxidation were preserved in all the studied tissues. Altered mitochondrial function of IUGR is especially present at placental and neonatal level, conveying potential targets to modulate obstetric outcome through dietary interventions aimed to regulate Sirtuin3 function. 相似文献
67.
Hanping Qi Jing Ren Mingyao E Qianhui Zhang Yonggang Cao Lina Ba Chao Song Pilong Shi Bowen Fu Hongli Sun 《Journal of cellular and molecular medicine》2019,23(3):1926-1939
Cardiac hypertrophy is a common pathological change frequently accompanied by chronic hypertension and myocardial infarction. Nevertheless, the pathophysiological mechanisms of cardiac hypertrophy have never been elucidated. Recent studies indicated that miR‐103 expression was significantly decreased in heart failure patients. However, less is known about the role of miR‐103 in cardiac hypertrophy. The present study was designed to investigate the relationship between miR‐103 and the mechanism of pressure overload‐induced cardiac hypertrophy. TRPV3 protein, cardiac hypertrophy marker proteins (BNP and β‐MHC) and autophagy associated proteins (Beclin‐1 and LC3‐II) were up‐regulated, as well as, miR‐103 expression and autophagy associated proteins (p62) were down‐regulated in cardiac hypertrophy models in vivo and in vitro respectively. Further results indicated that silencing TRPV3 or forcing overexpression of miR‐103 could dramatically inhibit cell surface area, relative fluorescence intensity of Ca2+ signal and the expressions of BNP, β‐MHC, Beclin‐1 and LC3‐II, but promote p62 expression. Moreover, TRPV3 protein was decreased in neonatal rat ventricular myocyte transfected with miR‐103, but increased by AMO‐103. Co‐transfection of the miR‐103 with the luciferase reporter vector into HEK293 cells caused a sharp decrease in luciferase activity compared with transfection of the luciferase vector alone. The miR‐103‐induced depression of luciferase activity was rescued by an AMO‐103. These findings suggested that TRPV3 was a direct target of miR‐103. In conclusion, miR‐103 could attenuate cardiomyocyte hypertrophy partly by reducing cardiac autophagy activity through the targeted inhibition of TRPV3 signalling in the pressure‐overloaded rat hearts. 相似文献
68.
Dhimitrius N. P. S. de Oliveira Pedro I. C. Claro Raquel R. de Freitas Maria A. Martins Tiago M. Souza Breno M. da S. e Silva Lourival M. Mendes Lina Bufalino 《化学与生物多样性》2019,16(9)
The açaí fruit depulping produces large amounts of long lignocellulosic fiber bundles that are disposed in the environment. Chemical pretreatments may improve açaí fibers favoring their usage in advanced materials. This work aimed to define optimal alkali reaction parameters to improve the properties of açaí fibers. Two NaOH concentrations (5 % and 10 %) and two reaction temperatures (80 °C and 100 °C) were tested. The raw and treated fibers were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X‐ray diffraction, and thermal analyses. All the alkali pretreatments separated fibers from the bundles, unblocked pit channels by removing silicon structures, exposed the inner lignin, partially removed non‐cellulosic compounds, and raised the cellulose crystalline index. The highest temperature and NaOH content resulted in better cleaning and isolation of the fibers, while milder conditions better preserved the cellulose crystalline structure and thermal stability. 相似文献
69.
Lina B. Flor-Weiler Robert W. Behle Eric T. Johnson Daniel A. Strickman Alejandro P. Rooney 《Biocontrol Science and Technology》2019,29(1):68-82
We evaluated the potential of a granular formulation of Metarhizium brunneum F52 containing microsclerotia (MbMSc granules) for control of Aedes aegypti by targeting eggs. MbMSc granules produced infective conidia within 14 days after application to 2.5?g moist potting soil, producing 5.9?×?105, 2.08?×?106 and 6.85?×?106 conidia from 1, 5 and 25?mg MbMSc granules, respectively. Application of MbMSc triggered premature eclosion of eggs (EC50?=?12?mg) with percentages as high as 31?±?2.9% and 67?±?4.3% of the eggs treated with 5 and 25?mg MbMSc granules, respectively, after 14 days on moist filter paper. Premature eclosion of eggs started at 3 days subsequent to MbMSc granule application and survival of larvae was significantly reduced for granule treated eggs (74?±?2.2%, 39?±?2.0% and 23?±?4.9% larvae survived for 1, 5 and 25?mg granule treatments, respectively, EC50?=?4.9?mg). When MbMSc granules were applied in moist potting soil with mosquito eggs, rates of 1, 5 and 25?mg of MbMSc granules significantly reduced adult emergence with only 81?±?2.1%, 47?±?1.9%, and 34?±?2.1% emergence, respectively (EC50?=?7?mg). Eggs treated with increasing concentrations of fungal conidia enhanced premature eclosion of eggs with an EC50?=?1.6?×?106 conidia/mL. Our results demonstrate that MbMSc granules are a promising candidate for control of A. aegypti and that fermentative production of Mb F52 microsclerotia as the active propagule has the potential for use for mosquito control. 相似文献
70.
Yueming Zhang Wenrui Zhang Lina Tao Jinghui Zhai Huan Gao Yanqing Song Xiaoyu Qu 《Journal of biochemical and molecular toxicology》2019,33(9)
Isoniazid (INH) is one of the most commonly used antituberculosis drugs, but its clinical applications have been limited by severe hepatic toxicity. Quercetin (Que), a natural flavonoid, has been proved to have many medicinal properties. This study aimed to clarify the possible protective effects of Que against INH‐induced hepatotoxicity using HepG2 cells. Our results indicated that Que significantly increased cell viability, superoxide dismutase, and GSH levels, while decreased alanine aminotransferase/aspartate aminotransferase levels. Besides, Que significantly abrogated INH‐induced cell apoptosis by upregulating the expression levels of Bcl‐2 and decreasing the levels of Bax, cleaved caspase‐3, and cleaved caspase‐9. Furthermore, Que obviously reversed the inhibition of INH on Sirtuin 1 (SIRT1) expression and extracellular signal‐regulated kinase (ERK) phosphorylation. Next, the SIRT1 inhibitor EX527 blocked the enhancement of Que upon ERK phosphorylation. Notably, EX527 partially abolished the beneficial effects of Que. In brief, our results provided the first evidence that Que protected against INH‐induced HepG2 cells by regulating the SIRT1/ERK pathway. 相似文献