全文获取类型
收费全文 | 651篇 |
免费 | 43篇 |
专业分类
694篇 |
出版年
2022年 | 13篇 |
2021年 | 19篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 7篇 |
2015年 | 16篇 |
2014年 | 28篇 |
2013年 | 49篇 |
2012年 | 49篇 |
2011年 | 63篇 |
2010年 | 14篇 |
2009年 | 25篇 |
2008年 | 26篇 |
2007年 | 18篇 |
2006年 | 22篇 |
2005年 | 21篇 |
2004年 | 30篇 |
2003年 | 10篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1996年 | 4篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 16篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 18篇 |
1974年 | 15篇 |
1973年 | 3篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有694条查询结果,搜索用时 0 毫秒
681.
When the chemical carcinogen, DMBA, is administered by intragastric intubation to young adult female mice already subjected to partial hepatectomy, the glycolytic key enzymes (hexokinases, phosphofructokinase, pyruvate kinase) and lactate dehydrogenase show declined levels in the regenerating liver. But concomitant administration of MPG, a hepatotropic detoxicant, with DMBA either nullifies or minimizes the effect of the carcinogen on these enzymes. 相似文献
682.
683.
Bruce D. Naumann Keith C. Silverman Rakesh Dixit Ellen C. Faria Edward V. Sargent 《人类与生态风险评估》2001,7(1):61-105
Investigations were performed on representative compounds from five different therapeutic classes to evaluate the use of categorical data-derived adjustment factors to account for interindividual variability. The five classes included antidepressants, angiotensin converting enzyme (ACE) inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDS), cholesterol lowering agents, and antibiotics. Each of the case studies summarized the mode of action of the class responsible for both the therapeutic and adverse effects and the key pharmacodynamic (PD) and pharmacokinetic (PK) parameters that determine the likelihood of these responses for individual compounds in the class. For each class, an attempt was made to identify the key factors that determine interindividual variability and whether there was a common basis to establish a categorical default adjustment factor that could be applied across the class (or at least across specific subclasses within the class). Linking the PK and PD parameters to the critical endpoint used to establish a safe level of exposure was an important underlying theme throughout the investigations. Despite the wealth of PK and PD information in the published literature on the surrogate compounds representing these classes, it was difficult to derive a categorical adjustment factor that could be applied broadly within each class. The amount of information available may have hindered rather than helped the evaluations. Derivation of categorical defaults for different classes of “common” chemicals may be more straightforward if sufficient data are available. In a few cases (e.g., tricyclic antibiotics, ACE inhibitors and selected antiinflammatory agents) categorical defaults could be proposed, although it is unclear whether the reduction in uncertainty resulting from their application would be offset by the additional uncertainties that may have resulted from their application. Residual uncertainties may remain depending on the level of confidence in the underlying assumptions used to support the categorical defaults. Regardless of the conclusions on the utility of categorical defaults, these investigations provided further support for the use of data-derived adjustment factors on a compound-specific basis. 相似文献
684.
685.
Hun-Ki Chung ;Kyu-Won Kim ;Jong-Wook Chung ;Jung-Ro Lee ;Sok-Young Lee ;Anupam Dixit ;Hee-Kyoung Kang ;Weiguo Zhao ;Kenneth L. McNally ;Ruraidh S. Hamilton ;Jae-Gyun Gwag ;Yong-Jin Park 《Acta Botanica Sinica》2009,(12):1116-1125
A new heuristic approach was undertaken for the establishment of a core set for the diversity research of rice. As a result, 107 entries were selected from the 10 368 characterized accessions. The core set derived using this new approach provided a good representation of the characterized accessions present in the entire collection. No significant differences for the mean, range, standard deviation and coefficient of variation of each trait were observed between the core and existing collections. We also compared the diversity of core sets established using this Heuristic Core Collection (HCC) approach with those of core sets established using the conventional clustering methods. This modified heuristic algorithm can also be used to select genotype data with allelic richness and reduced redundancy, and to facilitate management and use of large collections of plant genetic resources in a more efficient way. 相似文献
686.
Snehil Dixit Irfan Ahmad Kumar Gular Refaat A. Eid Ravi Shankar Reddy Ivana Leão Ribeiro Mohammed Abohashrh Mastour Saeed Alshahrani Jaya Shanker Tedla Nitin Arun Dixit 《Saudi Journal of Biological Sciences》2021,28(3):1678-1686
ObjectivesThe primary purpose of the recent experiment was to scrutinize the dissimilarity between single and multiple exposures by electrotherapeutic modalities to determine the development of Gram-positive and Gram negative bacteria spectrum.Material and methodsBacterial strains employed in this study were Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonae and Gram-positive bacteria such as Staphylococcus aureus, Staphylococcus saprophyticus and Streptococcus pyogenes. Fluence for Low level laser therapy (LLLT) (810 nm) was 40 J/cm2 for 80 s, for microwave (MWD) a dosage of 100-Watt with duration of 5 min and for magnetic field therapy (MT) duration of 30 min with 100% intensity was used.ResultsRepeated Measures of analysis of variances (RANOVA) for within-subject effects was used to detect a global significant change within the means at dissimilar time points. The experiments of within-subjects revealed a significant difference within groups, df of (3, 40), F value of 39.38 and a p value less than 0.001, representing a significant variation between the three groups between pre and post exposures. There was a significant variation between single exposure and multiple exposures in the experimental sample’s pre-post between the four groups with df (1, 40) f value of 2943.69 and p value less than 0.001. Scanning and Transmission electron microscopy images were also taken into account to determine the extent of damage caused to the bacterial cells surface topography in Gram negative and Gram positive spectrums.ConclusionThe study demonstrated that single high exposure with the LLLT appears to have the most emphatic effect followed by exposure by MWD and MT. 相似文献
687.
688.
Soumya R. Jena Jasmine Nayak Sugandh Kumar Sujata Kar Anshuman Dixit Luna Samanta 《Molecular reproduction and development》2021,88(1):96-112
Recent evidence entail paternal factors as plausible contributors in spontaneous recurrent pregnancy loss (RPL). Seminal extracellular vesicles secreted from cells of male reproductive tract carry regulatory proteins and RNAs. They are proposed to regulate sperm maturation and function while their fusion to endometrial stromal cells helps in decidualization. Nevertheless, the mechanism(s) involved in these processes are poorly understood. This study aims at elucidating the molecular basis of paternal contribution by comparative proteomics (label‐free LC‐MS/MS) of isolated seminal extracellular vesicles from fertile men and partners of patients with RPL (n = 21 per group). Bioinformatics analysis revealed the identified differentially expressed proteins to be involved in DNA replication, recombination and repair, gene expression, cellular assembly and organization, cell death, and survival. Major disease pathways affected were identified as developmental, hereditary, and immunological disorders. Of the three identified hub genes regulating the above disease pathways, two (HNRNPC and HNRNPU) are overexpressed while RUVBL1 is underexpressed along with over expression of HIST1H1C, DDX1, surmising defective chromatin packaging, and histone removal in spermatozoa resulting in improper expression in paternal genes thereby leading to abnormal embryo development. Besides, alteration in GSTP1 expression points oxidative predominance in RPL group. Differential expression of C3, C4a/C4b, CFB, and GDF 15 may be involved in altered maternal immune response to paternal antigens resulting in impaired decidualization. 相似文献
689.
Dixit Neeraj Kumar Kumar Anup 《International journal of peptide research and therapeutics》2021,27(2):1385-1396
International Journal of Peptide Research and Therapeutics - Dengue is an infectious disease caused by one of the four serotypes of the dengue virus. It is a mosquito borne disease and the female... 相似文献
690.
During screening of the leaves of 25 plant species for their volatile toxicity against the test pathogen Fusarium lateritium f.sp.cajani, Aegle marmelos (Ae), Citrus aurantifolia (Ci) and Mentha arvensis var. piperascens (Me) exhibited strong toxicity inhibiting the mycelial growth completely. The active volatile constituents from each plant were isolated in the form of essential oil and the fungitoxicity of each oil was tested separately. The Aegle oil was found fungistatic while Citrus and Mentha oils were fungicidal in nature. Three oil combination (1:1 v/v) viz., Ae-Ci, Ae-Me and Ci-Me were made and their fungitoxicity was tested. The oil combinations were found to be more fungitosic than the individual oils, which were fungistatic in nature. The Ci-Me combination exhibited a broad fungitoxic spectrum while the other two Ae-Ci and Ae-Me possessed a narrow range of toxicity. The oils were found to have no toxic effect on seed germination, seedling growth (root and shoot length), and general morphology of the host plant(Cajanus cajan). 相似文献