全文获取类型
收费全文 | 488篇 |
免费 | 28篇 |
出版年
2024年 | 3篇 |
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 23篇 |
2020年 | 22篇 |
2019年 | 43篇 |
2018年 | 22篇 |
2017年 | 14篇 |
2016年 | 9篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 37篇 |
2012年 | 35篇 |
2011年 | 43篇 |
2010年 | 21篇 |
2009年 | 20篇 |
2008年 | 18篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 20篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1970年 | 7篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有516条查询结果,搜索用时 15 毫秒
1.
2.
3.
Robert F. Steiner Mahnaz Motevalli-Alibadi 《Archives of biochemistry and biophysics》1984,234(2):522-530
The average separation of the phenolic groups of tyrosine-99 and tyrosine-138 has been measured by radiationless energy transfer between each tyrosine and the nitro derivative of the second tyrosine. A separation of 16.7 ± 0.7 Å was found in the absence of Ca2+ and 15.5 ± 0.7 Å in the presence of Ca2+. 相似文献
4.
5.
Effect of Drought Stress on Certain Morphological and Physiological Characteristics of a Resistant and a Sensitive Canola Cultivar 总被引:1,自引:0,他引:1
Ghorban Khodabin Zeinolabedin Tahmasebi‐Sarvestani Amir Hossein Shirani Rad Seyed Ali Mohammad Modarres‐Sanavy 《化学与生物多样性》2020,17(2)
Water stress is one of the main abiotic factors that reduces plant growth, mainly due to high evaporative demand and low water availability. In order to evaluate the effects of drought stress on certain morphological and physiological characteristics of two canola cultivars, we conducted a factorial experiment based on a completely randomized design. The findings show that drought stress exacerbations result in the plant's response to stress due to increased canola resistance caused by changes in plant pigments, proline, catalase, ascorbate peroxidase, peroxidase, superoxide dismutase and malondialdehyde, glucose, galactose, rhamnose and xylose. These in turn ultimately influence the morphological characteristics of canola. Drought stress reduces the concentration of carotenoids, chlorophyll a, chlorophyll b, total chlorophylls; however, glucose, galactose, rhamnose, xylose, proline, catalase, ascorbate peroxidase, peroxidase, superoxide dismutase, malondialdehyde (in leaves and roots) and the chlorophyll a and b ratios were increased. Reduction of plant height, stem height, root length, fresh and dry weight of canola treated with 300 g/l PEG compared to non‐treatment were 0.264, 0.236, 0.394, 0.183 and 0.395, respectively. From the two canola cultivars, the morphological characteristics of the NIMA increased compared to the Ks7 cultivar. Interaction effects of cultivar and drought stress showed that NIMA cultivar without treatment had the highest number of morphological characteristics such as carotenoid concentration, chlorophyll a, chlorophyll b, total chlorophylls a and b, whereas the cultivar with 300 g/l PEG (drought stress) had the highest amount of proline, malondialdehyde, soluble sugars and enzymes in leaves and roots. Increasing activity of oxidative enzymes and soluble sugars in canola under drought stress could be a sign of their relative tolerance to drought stress. 相似文献
6.
Oghbaei Hajar Hosseini Leila Farajdokht Fereshteh Rahigh Aghsan Sepideh Majdi Alireza Sadigh-Eteghad Saeed Sandoghchian Shotorbani Siamak Mahmoudi Javad 《Molecular biology reports》2021,48(8):5881-5887
Molecular Biology Reports - The current study was set to assess the effect of heat stress exposure on oxidative stress, apoptosis, and endoplasmic reticulum stress markers in the cerebellum of male... 相似文献
7.
Plasmonics - The guiding properties of a symmetric conductor–gap–dielectric system consists of a metal film symmetrically surrounded by media of two dielectrics, and is theoretically... 相似文献
8.
Sanaz Khaseb Mahdi Orooji Majid Ghasemian Pour Seyed Mohammadreza Safavi Mohammad Jafar Eghbal Maryam Rezai Rad 《Cell biology international》2021,45(9):1851-1865
Dental tissue-derived stem cells (DSCs) provide an easy, accessible, relatively noninvasive promising source of adult stem cells (ASCs), which brought encouraging prospective for their clinical applications. DSCs provide a perfect opportunity to apply for a patient's own ASC, which poses a low risk of immune rejection. However, problems associated with the long-term culture of stem cells, including loss of proliferation and differentiation capacities, senescence, genetic instability, and the possibility of microbial contamination, make cell banking necessary. With the rapid development of advanced cryopreservation technology, various international DSC banks have been established for both research and clinical applications around the world. However, few studies have been published that provide step-by-step guidance on DSCs isolation and banking methods. The purpose of this review is to present protocols and technical details for all steps of cryopreserved DSCs, from donor selection, isolation, cryopreservation, to characterization and quality control. Here, the emphasis is on presenting practical principles in accordance with the available valid guidelines. 相似文献
9.
Masoud Darvish Ganji Mahnaz Nashtahosseini Saeed Yeganegi Mahyar Rezvani 《Journal of molecular modeling》2013,19(4):1929-1936
The interaction between oxazepam and C60 fullerene was explored using first-principles vdW-DF calculations. It was found that oxazepam binds weakly to the fullerene cage via its carbonyl group. The binding of oxazepam to C60 is affected drastically by nonlocal dispersion interactions, while vdW forces affect the corresponding geometries only a little. Furthermore, aqueous solution affects the geometries of the oxazepam approaching to fullerene slightly, while oxazepam binds slightly farther away from the nanocage. The results presented provide evidence for the applicability of the vdW-DF method and serve as a practical benchmark for the investigation of host–guest interactions in biological systems. Figure
ab initio vdW-DF study on the possibility of formation of oxazepam/C60 complex at aqueous solution 相似文献
10.
Mahnaz Sadeghi Sara Dehghan Rainer Fischer Uwe Wenzel Andreas Vilcinskas Hamid Reza Kavousi Mohammad Rahnamaeian 《Plant signaling & behavior》2013,8(11)
Salicylic acid (SA) is a prominent signaling molecule during biotic and abiotic stresses in plants biosynthesized via cinnamate and isochorismate pathways. Cinnamate 4-hydroxylase (C4H) and isochorismate synthase (ICS) are the main enzymes in phenylpropanoid and isochorismate pathways, respectively. To investigate the actual roles of these genes in resistance mechanism to environmental stresses, here, the coding sequences of these enzymes in safflower (Carthamus tinctorius), as an oilseed industrial medicinal plant, were partially isolated and their expression profiles during salinity stress, wounding, and salicylic acid treatment were monitored. As a result, safflower ICS (CtICS) and C4H (CtC4H) were induced in early time points after wounding (3–6 h). Upon salinity stress, CtICS and CtC4H were highly expressed for the periods of 6–24 h and 3–6 h after treatment, respectively. It seems evident that ICS expression level is SA concentration dependent as if safflower treatment with 1 mM SA could induce ICS much stronger than that with 0.1 mM, while C4H is less likely to be so. Based on phylogenetic analysis, safflower ICS has maximum similarity to its ortholog in Vitis vinifera up to 69%, while C4H shows the highest similarity to its ortholog in Echinacea angustifolia up to 96%. Overall, the isolated genes of CtICS and CtC4H in safflower could be considered in plant breeding programs for salinity tolerance as well as for pathogen resistance. 相似文献