全文获取类型
收费全文 | 320篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
347篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 27篇 |
2017年 | 9篇 |
2016年 | 20篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 26篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有347条查询结果,搜索用时 0 毫秒
341.
Asma Chaudhary Afia Muhammad Akram Ayesha Aihetasham Zawar Hussain Afshan Syed Abbas Rahat Abdul Rehman Qurat-ul-Ain Ahmad Anjum Tahira Ayesha Saleem Samina Qamer Youssef Alghamdi Samy F. Mahmoud Samy Sayed 《Saudi Journal of Biological Sciences》2021,28(7):3710-3719
Pomegranate peels (PPW) as municipal waste is inexpensive biomass that could be a renewable source of sugars particularly rich in hemicellulosic contents. The subsequent conversion of available sugars in PPW can provide prospective strategy for cost-effective bioenergy production. In this study, an experimental setup based on CCD was implemented with the aim of bioconversion of biomass into bioethanol. The factors considered were Hydrochloric acid concentration (X1), the hydrolysis temperature (X2) and time (X3) for optimization with dilute Hydrochloric acid (HCl) saccharification. The present study investigates the optimised level of bioethanol synthesis from acid pre-treated PPW explained by RSM. Subsequently, three yeasts viz. Saccharomyces cerevisiae K7, Metschnikowia sp. Y31 and M. cibodasensis Y34 were utilized for fermentation of acid hydrolysed and detoxified feed stocks. Optimum values of reducing sugars 48.02 ± 0.02 (gL?1) and total carbohydrates 205.88 ± 0.13 (gL?1) were found when PPW was hydrolyzed with 1% HCl concentration at 100?C of temperature for 30 min. Later on, fermentation of PPWH after detoxification with 2.5% activated charcoal. The significant ethanol (g ethanol/g of reducing sugars) yields after fermentation with Metschnikowia sp. Y31 and M. cibodasensis Y34 found to be 0.40 ± 0.03 on day 5 and 0.41 ± 0.02 on last day of experiment correspondingly. Saccharomyces cerevisiae K7 also produce maximum ethanol 0.40 ± 0.00 on last day of incubation utilizing the PPWH. The bioconversion of commonly available PPW into bioethanol as emphasize in this study could be a hopeful expectation and also cost-effective to meet today energy crisis. 相似文献
342.
Ming Hu Inês Cebola Gaelle Carrat Shuying Jiang Sameena Nawaz Amna Khamis Mickaël Canouil Philippe Froguel Anke Schulte Michele Solimena Mark Ibberson Piero Marchetti Fabian L. Cardenas-Diaz Paul J. Gadue Benoit Hastoy Leonardo Almeida-Souza Harvey McMahon Guy A. Rutter 《Cell reports》2021,34(5):108703
343.
Nuclei of multinucleate cells generally initiate DNA synthesis simultaneously, suggesting that the timing of DNA synthesis depends upon the appearance of a cytoplasmic signal. In contrast, intact nuclei from quiescent mammalian cells initiate DNA synthesisasynchronouslyin cell-free extracts ofXenopuseggs, despite the common environment. Here we show that the two nuclei of permeabilized binucleate cells enter DNA synthesis coordinately in egg extracts, as they doin vivo,with different pairs of nuclei initiating replication at different times. This indicates that the two nuclei of a binucleate cell are identical in their sensitivity to the inducers of DNA synthesis in egg extracts; this sensitivity varies in general between the nuclei of unrelated cells. The asynchrony of DNA synthesis shown by unrelated nuclei in egg extracts is therefore not an artifact of the cell-free system but a reflection of genuine differences preexisting within the intact cell. Evidence that these differences between nuclei are responsible for a substantial fraction of G1variability in living cells is presented. 相似文献
344.
3-Methylthiopropylamine and (R)-3-methylsulphinylpropylamine have been isolated from Iberis amara and identified by PC, high voltage electropho 相似文献
345.
O. Zethner Bashir M. Khan M. Ismail Chaudhry B. Bolet Sharfuddin Khan Habibullah Khan Hanif Gul L. Øgaard M. Zaman Gul Nawaz 《BioControl》1987,32(5):449-455
Agrotis segetum Schiff granulosis virus (AsGV) propagated in Denmark was supplied against naturally occurring cutworm populations (A. ipsilon and to a less extentA. segetum) in experimental field plots of tobacco, okra, potato and sugar beet in northern Pakistan. AsGV doses varied between 4 ×
107 and 4 × 1011 capsules per m2 plot, and no. of applications between 1 and 3.
One treatment with AsGV did not reduce cutworm damage significantly to tobacco seedlings and potato plants.
Two treatments with AsGV reduced cutworm damage significantly. In tobacco, reduction was 64–82%, in okra and potato 85% and
77% respectively. Damage in sugar beet was reduced 78%.
Three treatments with AsGV dis not reduce damage significantly better than two treatments.
AsGV and the chemical insecticides Tamaran and Dieldrin, andBacillus thuringiensis (Thuricide) were about equally effective, reducing damage by 85%, 79%, 87% and 69%, respectively. No difference was found
between the efficiency of highly purified AsGV to which activated charcoal was added and partially purified AsGV without charcoal.
相似文献
346.
Genetic Ablation of the Steroid Receptor Coactivator-Ubiquitin Ligase, E6-AP, Results in Tissue-Selective Steroid Hormone Resistance and Defects in Reproduction 下载免费PDF全文
Carolyn L. Smith Darryll G. DeVera Dolores J. Lamb Zafar Nawaz Yong-Hui Jiang Arthur L. Beaudet Bert W. OMalley 《Molecular and cellular biology》2002,22(2):525-535
The E6-associated protein (E6-AP), although originally identified as a ubiquitin ligase, has recently been shown to function as a coactivator of steroid receptor-dependent gene expression in in vitro assays. In order to determine whether E6-AP acts as a coactivator in vivo, physiological parameters associated with male and female sex steroid action were assessed in the E6-AP null mouse. Gonadal size was reduced in E6-AP null male and female mice in comparison to wild-type controls in conjunction with reduced fertility in both genders. Consistent with this observation, defects in sperm production and function, as well as ovulation were observed. In comparison to wild-type controls, induction of prostate gland growth induced by testosterone and uterine growth by estradiol were significantly reduced. In contrast, estrogen and progesterone-stimulated growth of virgin mammary gland was not compromised by E6-AP ablation despite E6-AP expression in this tissue. This latter finding contrasts with the impaired estrogen and progesterone-induced mammary gland development observed previously for steroid receptor coactivator type 1 (SRC-1) and SRC-3 female knockout mice. Taken together, these results are consistent with a role for E6-AP in mediating a subset of steroid hormone actions in vivo. Nevertheless, differences observed between SRC and E6-AP knockout phenotypes indicate that these two families of steroid receptor coactivators are not functionally equivalent and supports the hypothesis that coactivators contribute to tissue-specific steroid hormone action. 相似文献