全文获取类型
收费全文 | 466篇 |
免费 | 18篇 |
国内免费 | 1篇 |
专业分类
485篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 13篇 |
2013年 | 41篇 |
2012年 | 45篇 |
2011年 | 33篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 20篇 |
2007年 | 24篇 |
2006年 | 13篇 |
2005年 | 22篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有485条查询结果,搜索用时 0 毫秒
11.
Abdul Rashid War Hari Chand Sharma Michael Gabriel Paulraj Mohd Yousf War Savarimuthu Ignacimuthu 《Plant signaling & behavior》2011,6(12):1973-1978
Plants respond to herbivory through different defensive mechanisms. The induction of volatile emission is one of the important and immediate response of plants to herbivory. Herbivore-induced plant volatiles (HIPVs) are involved in plant communication with natural enemies of the insect herbivores, neighboring plants, and different parts of the damaged plant. Release of a wide variety of HIPVs in response to herbivore damage and their role in plant-plant, plant-carnivore and intraplant communications represents a new facet of the complex interactions among different trophic levels. HIPVs are released from leaves, flowers, and fruits into the atmosphere or into the soil from roots in response to herbivore attack. Moreover, HIPVs act as feeding and/or oviposition deterrents to insect pests. HIPVs also mediate the interactions between the plants and the microorganisms. This review presents an overview of HIPVs emitted by plants, their role in plant defense against herbivores and their implications for pest management. 相似文献
12.
13.
Srinivas M. R. S. Chand Nagin Lonsane B. K. 《Bioprocess and biosystems engineering》1994,10(3):139-144
Five sources of nitrogen, six minerals, six enzyme inducers and one each of growth as well as product promotors were screened by Plackett-Burman design, consisting of a total of 20 experiments for the above 19 sources/categories of medium ingredients, for their effect on the production of alpha-galactosidase by Aspergillus niger MRSS 234 in solid state fermentation system. The enzyme production was recorded from 2 to 5 days of fermentation. Data on enzyme titres was analysed by compatible analysis to obtain regression coefficients and t-ratios. Among the nitrogen sources, urea contributed positively to enzyme production and its effect increased with the fermentation time, in contrast to negative effect of all the ammonium salts used. Corn steep liquor, citric acid and legume seed flours showed significantly positive effects on enzyme production, though lactose showed negative effect upto 3 days of fermentation and then turned positive but not significantly. Calcium chloride and ferrous sulphate showed considerable negative effect, in contrast to mixed effect by other mineral salts studied. Among the legume seed flours, guar and French bean flours showed larger positive effects. The studies allowed the selection of urea, corn steep liquor, guar flour, soy bean flour and citric acid as most promising sources/categories for further optimization studies based on the effects as well as their trend with fermentation time. The use of Plackett-Burman design for rapid screening of large number of nutrients, in a very small number of experiments, for reliable short-listing of a few of most effective sources/categories for further optimization, has been scarce in submerged fermentation and never attempted earlier in solid state fermentation system.Authors are thankful to Dr. S. R. Bhowmik, Director of the institute for interest in the work. M. R. S. Srinivas thanks Council of Scientific and Industrial Research, New Delhi, for the award of junior research fellowship. 相似文献
14.
Savita Rani Sanjeev Kumar Syed Mudassir Jeelani Raghbir Chand Gupta Santosh Kumari 《Plant Systematics and Evolution》2012,298(2):485-497
At present 14 species of Potentilla L. have been cytologically worked out from different geographical areas of Kashmir and Himachal Pradesh in the Western Himalayas.
New chromosome numbers in nine species—Potentilla argyrophylla (n = 14), P. atrosanguinea (n = 7, 14), P. desertorum (n = 7), P. gerardiana (n = 14), P. indica (n = 14), P. micropetala (n = 14), P. nepalensis (n = 14), P. sibbaldia (n = 14) and P. thomsonii (n = 7)—have been reported on a worldwide basis for the first time. Additional chromosomal races of polyploid cytotypes for
P. argyrophylla (n = 28) and P. desertorum (n = 14) along with a diploid cytotype for P. micropetala (n = 7) plus diploid cytotypes for the five species as P. fulgens (n = 7), P. gelida (n = 7), P. kleiniana (n = 7), P. sibbaldia (n = 7) and P. sundaica (n = 7) as well as a tetraploid cytotype for P. fruticosa (n = 14) all have been cytologically worked out from India for the first time. The course of meiosis varies from normal to abnormal
in different populations of the majority of the species, such as P. argyrophylla, P. atrosanguinea, P. desertorum, P. fruticosa, P. fulgens, P. gelida, P. indica, P. nepalensis, P. sibbaldia and P. sundaica, except for normal meiosis observed in P. gerardiana, P. kleiniana, P. micropetala and P. thomsonii. The anomalous taxa are marked with meiotic abnormalities in the form of cytomixis, chromosomal stickiness, unoriented bivalents,
formation of laggards and bridges resulting in abnormal microsporogenesis, and production of heterogenous-sized fertile pollen
grains along with reduced pollen fertility. All the taxa with normal meiotic courses show nearly one hundred percent pollen
fertility. 相似文献
15.
doi: 10.1111/j.1741‐2358.2010.00414.x Effect of bone mineral density on masticatory performance and efficiency Objective: To evaluate the effect of bone mineral density (BMD) on masticatory performance and efficiency in dentate subjects. Background data: Osteoporosis is the most common disorder of the bone. It causes reduction in BMD of the all the skeletal tissue including jaw bones. It also promotes bone loss in jaw bones. In osteoporosis, a reduction of maximal bite force and greater electromyography activity of masticatory muscles is documented. This may lead to the development of masticatory dysfunction which can be assessed by a chewing test in the form of change in masticatory performance and efficiency. Materials and methods: Sixty subjects with equal numbers of men and women were selected for the study, in which BMD screening (T‐score) was carried out to identify the normal, osteopenic and osteoporotic subjects. Their masticatory performance and efficiency was evaluated by a chewing test (fractional sieving method). Results: A high ‘T’ score was associated with low masticatory efficiency and a low ‘T’ score with high masticatory efficiency. Masticatory performance and efficiency was significantly higher among males as compared to females with similar range of BMD. Conclusion: In both genders, high BMD groups (low ‘T’ score) had a significantly high percentage of masticatory efficiency compared to the low BMD (high ‘T’ score) group. 相似文献
16.
Primary structure of β-chain of pigeon is presented. It was determined by amino acid sequence analysis of intact β-chain and its peptides obtained by the enzymatic and chemical cleavage. Comparison of amino acid sequence of the chain with other available data shows β 14 Ile, β61 Lys, and β113 Ile as residues specific to pigeon. One important replacement at α1β1 contact is β55 Met→Ser. 相似文献
17.
Background
Substituted catechols are important precursors for large-scale synthesis of pharmaceuticals and other industrial products. Most of the reported chemical synthesis methods are expensive and insufficient at industrial level. However, biological processes for production of substituted catechols could be highly selective and suitable for industrial purposes. 相似文献18.
Generation and characterization of anti-MUC4 monoclonal antibodies reactive with normal and cancer cells in humans. 总被引:3,自引:0,他引:3
Nicolas Moniaux Grish Chandra Varshney Subhash Chand Chauhan Marie Christine Copin Maneesh Jain Uwe A Wittel Mahefatiana Andrianifahanana Jean-Pierre Aubert Surinder Kumar Batra 《The journal of histochemistry and cytochemistry》2004,52(2):253-261
We have previously cloned the full-length cDNA (approximately 28 Kb) and established the complete genomic organization (25 exons/introns over 100 kb) of the human MUC4 mucin. This large molecule is predicted to protrude over 2 microm above the cell surface, in which MUC4alpha is an extracellular mucin-type glycoprotein subunit and MUC4beta is the transmembrane subunit. Over two thirds of the encoded protein sequence consists of 16-amino-acid tandem repeats (TR), which are flanked by unique sequences. In this study we generated and characterized monoclonal antibodies (MAbs) directed against the TR region of MUC4. Mice were immunized with a KLH-conjugated MUC4 TR peptide, STGDTTPLPVTDTSSV. Several clones were purified by three rounds of limited dilutions and stable clones presenting a sustained antibody production were selected for subsequent characterization. Antibodies were tested for their reactivity and specificity to recognize the MUC4 peptide and further screened by enzyme-linked immunosorbent assay (ELISA) and Western blotting analyses. One of the MAbs (8G7) was strongly reactive against the MUC4 peptide and with native MUC4 from human tissues or pancreatic cancer cells in Western blotting, immunohistochemistry, and confocal analysis. Anti-MUC4 MAb may represent a powerful tool for the study of MUC4 function under normal and pathological conditions and for diagnosis of solid tumors including those in the breast, pancreas, lungs, and ovaries. 相似文献
19.
Withania somnifera (WS) or its psychotropic preparation is known to play a critical role in morphine, alcohol and benzodiazepines addiction. This study investigates the role of WS in acute ethanol and withdrawal from chronic ethanol consumption using elevated plus maze paradigm in rats. Acute administration of ethanol (1.5-2 g/kg, ip) triggered anxiolytic effect and withdrawal from prolonged ethanol (9% v/v ethanol, 15 days) consumption elicited enhanced behavioral despair (anxiety). Acute administration of WS (50 mg/kg, oral) potentiated the anxiolytic action of subeffective dose of ethanol (0.5 or 1 g/kg, ip). Moreover, the ethanol withdrawal anxiety was markedly antagonized in dose dependent manner by WS at 200 and 500 mg/kg or higher dose of ethanol (2.5 g/kg). However, co-administration of subeffective doses of WS (50 mg/kg, oral) and ethanol also attenuated withdrawal-induced anxiety due to chronic ethanol (9% v/v ethanol, 15 days) consumption. The results suggest the protective effect of WS in the management of ethanol withdrawal reactions. 相似文献
20.