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排序方式: 共有274条查询结果,搜索用时 31 毫秒
181.
Sumitani K Miyamoto O Yamagami S Okada Y Itano T Murakami T Negi T 《Nihon seirigaku zasshi. Journal of the Physiological Society of Japan》2002,64(7-8):152-158
To determine whether severe long-term exercise affects on the brain, we investigated the mice brain after 12-week treadmill exercise. The mice (ddN, male, 25-35 g in body weight) were divided into severe, mild, and non-exercise group. Mice in severe groups ran on a treadmill at a speed of 25 m/min for 12 weeks and mice in mild group ran on a treadmill at a speed of 10 m/min for 12 weeks. The mice were killed by transcardial perfusion with 0.1 M phosphate-buffered saline (PBS) followed by ice-cold 4% paraformaldehyde in 0.1 M PB. The another sets of mice were fixed by 2.5% glutaraldehyde-2% osmium tetroxide for electromicroscope (EM). The brains were serially sectioned in the coronal plane at a thickness of 20-microns with a vibratome and then processed for histology, by means of hematoxylin-eosin (HE) staining and immunohistochemistry. Fifty % of mice in severe exercise showed hyperchromatic and shrunken nerve cells with nuclear pyknosis (dark neuron) in the hippocampus, but not in mild exercise and non-exercise groups. The immunoreactivity of microtuble associated protein-2 (MAP-2) decreased, while the heat-shock protein/cognate 70 (HSP/C 70) increased in the hippocampus of severe exercise group. Many destroyed mitochondria were observed in dark neurons by Electron micrograph. These findings suggested that severe long-term exercise might damage hippocampal neurons. 相似文献
182.
183.
Chandola-Saklani A Thapliyal A Negi K Diyundi SC Choudhary B 《Chronobiology international》2004,21(4-5):553-569
In some long-lived organisms, particularly in tropical birds and migrants that spend part of the year close to the equator, endogenous circannual rhythms have been demonstrated in seasonal events like reproduction, molt, and migration. These, like the circadian rhythms, are expressed only in constant conditions of illumination with a periodicity deviating from 1 yr. If birds followed this periodicity, they would soon be out of phase with the annual calendar and perish and, therefore, they would need to be synchronized. However, almost nothing is known as to how synchronization is achieved in birds. Herein, with the help of a suitable model, viz., the tropical spotted munia and long-term experiments conducted in series over a 5-yr period, we provide direct evidence for the first time indicating that the segment of annual photocycle with maximal rate of increase prior to vernal equinox (approximately between mid-February and mid-March) synchronizes the circannual reproductive cycle with the monsoon period of ample food supply through a phase delay. Data also indicate, contrary to the prevalent view, that birds in the tropics can perceive minor changes in day-length, that birds respond to progressive changes in day-length as distinct from responding to fixed photoperiods of particular durations, and that birds can actually distinguish the quality of the environmental signal, viz., vernal equinox from early spring, or increasing days of spring from decreasing days of autumn. The underlying mechanisms, although yet to be identified, appear to involve a gonado-inhibitory rather than the conventional gonado-stimulatory response to increasing day-length. The photoperiodic responses of spotted munia are distinctly different from that of any "long-day" birds described thus far and do not conform to the prevalent "circadian coincidence" hypothesis of photoperiodism. 相似文献
184.
Jayaprakasha GK Jena BS Negi PS Sakariah KK 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(9-10):828-835
Curcumin removed turmeric oleoresin (CRTO) was extracted with hexane concentrated to get turmeric oil, and that was fractionated using silica gel column chromatography to obtain three fractions. These fractions were analyzed by GC and GC-MS. Turmeric oil contained aromatic turmerone (31.32%), turmerone (15.08%) and curlone (9.7%), whereas fractions III has aromatic turmerone (44.5%), curlone (19.22%) and turmerone (10.88%) as major compounds Also, oxygenated compounds (5,6,8-10) were enriched in fraction III. Turmeric oil and its fractions were tested for antioxidant activity using the beta-carotene-linoleate model system and the phosphomolybdenum method. The fraction III showed maximum antioxidant capacity. These fractions were also used to determine their protective effect against the mutagenicity of sodium azide by means of the Ames test. All the fractions and turmeric oil exhibited a markedly antimutagenicity but fraction III was the most effective. The antioxidant effects of turmeric oil and its fractions may provide an explanation for their antimutagenic action. 相似文献
185.
Light regulated modulation of Z-box containing promoters by photoreceptors and downstream regulatory components,COP1 and HY5, in Arabidopsis 总被引:6,自引:0,他引:6
Yadav V Kundu S Chattopadhyay D Negi P Wei N Deng XW Chattopadhyay S 《The Plant journal : for cell and molecular biology》2002,31(6):741-753
The Z-box is one of the light-responsive elements (LREs) found in the promoters of light inducible genes. We have studied the light responsive characteristics of Z-box containing synthetic as well as native promoters. We show that promoters with Z-box as a single LRE or paired with another LRE can respond to a broad spectrum of light. The response is primarily mediated by phyA, phyB and CRY1 photoreceptors at their respective wavelengths of light. We have demonstrated that CAB1 and Z-GATA containing promoters are down-regulated in hy5 mutants in the light. On the other hand, a promoter with Z-box alone is down-regulated in hy5 mutants both in dark and in light conditions, suggesting involvement of a similar regulatory system in the regulation of the promoter in two distinct developmental pathways: skotomorphogenesis and photomorphogenesis. Furthermore, similar to the CAB1 promoter, a Z-GATA containing promoter is derepressed in cop1 mutants in the dark. DNA-protein interaction studies reveal the presence of a DNA-binding activity that is specific to Z-box. These results provide insights into the regulation of the Z-box LRE mediated by various light signaling components. 相似文献
186.
Analysis of genetic relatedness among Indian cattle (Bos indicus) using genotyping‐by‐sequencing markers
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A. A. Malik R. Sharma S. Ahlawat R. Deb M. S. Negi S. B. Tripathi 《Animal genetics》2018,49(3):242-245
Genetic relatedness of 24 animals belonging to seven Indian cattle breeds was studied using high throughput genotyping‐by‐sequencing (GBS) markers. GBS produced 93.6 million reads with an average of about 3.9 million reads per animal. A total of 107 488 SNPs were identified in these individuals. When only one SNP per read was considered, a total of 60 261 SNPs representing independent reads were identified with an average SNP‐to‐SNP distance of 45 kb across the bovine reference genome. About 24% of the GBS‐SNP markers were more than 100 kb apart. Of these, 58 322 SNPs mapped to autosomes, 1645 to the X chromosome and 28 to the Y chromosome. The average SNP‐to‐SNP distance on the X chromosome was 91.3 kb, whereas on the Y chromosome it was 1546.4 kb. The minor allele frequency within the Indian cattle varied from 0.103 (Ongole) to 0.177 (Siri), whereas Holstein cattle had the lowest value of 0.089. This is the first application of GBS in cattle of South Asia. The baseline information generated in this study might prompt implementation of GBS in breeding of cattle belonging to this region. 相似文献
187.
Chitra Pandey Vivek K. Bajpai Yogesh Kumar Negi Irfan A. Rather D.K. Maheshwari 《Saudi Journal of Biological Sciences》2018,25(6):1066-1071
Amaranth (Amaranthus hypochondriacus Linn.) is an important pseudocereal crop having important nutrients along with the indispensable amino-acids. The present study was aimed to study the effect of plant growth promoting bacilli on proximate constituents of amaranth grains, including three of the essential amino acids (methionine, lysine and, tryptophan). The combination of Bacillus pumilus and Bacillus subtilis showed a significant increase in different proximate constituents, including crude protein (22.13%), dry matter (32.25%), fat (30.77%), and carbohydrate (49.08%) in amaranth grains. Similarly, a significant increase in essential amino-acids (methionine 47.68%, lysine 59.41% and, tryptophan 38.05%) was recorded. This study suggests that the combination of Bacillus pumilus BS-27 and Bacillus subtilis BS-58 provides the natural, persistent and durable potential to enhance the nutritive value of the crop. Therefore, present study was designed to explore the enhancement of most desirable amino acid synthesis in amaranth due to application of plant growth promoting Bacillus spp. 相似文献
188.
Priyanka Mishra Mahendra Pal Singh Negi Mukesh Srivastava Kiran Singh Singh Rajender 《Reproductive biology and endocrinology : RB&E》2018,16(1):103
Background
Since the first report of a decline in semen quality in 1974, there have been several reports of similar declines across populations. Despite some scattered reports of declining semen quality in the Indian sub-continent, comprehensive studies analyzing semen quality over the last few decades have not been undertaken. We undertook the present study to investigate the temporal trend in semen parameters in Indian populations over a period of 37 years (1979–2016).Methods
Publications providing semen analysis details for fertile and infertile men from the Indian sub-continent were collected by a thorough literature search. Semen quality data for 6466 normal fertile or presumptive normal men (from 119 studies/data sets) and 7020 infertile men (from 63 studies/data sets) published between 1979 and 2016 were retrieved. We undertook systematic review and quantitative analysis of mean sperm count, motility, normal morphology and other available parameters. Data were analyzed to estimate semen parameters reference values for Indian men and to assess temporal trends in infertile, fertile and all subjects.Results
Seminal quality shows a decreasing temporal trend and the decrease is higher in infertile than fertile males. In pooled analysis for all individuals, significant (p?<?0.05 or?<?0.001) declines in sperm concentration and normal morphology are observed; however, isolated analysis for each group shows declines without statistical significance. The mean (± SD) semen volume, sperm concentration, total motility, rapid linear progressive motility, normal sperm morphology and sperm viability for Indian fertile men are 2.88?±?0.77 ml, 81.08?±?29.21 million/ml, 66.37?±?10.95%, 52.64?±?15.78%, 56.68?±?20.23% and 72.63?±?8.31%, respectively, whereas in infertile these are 3.07?±?1.27 ml, 37.94?±?26.41 million/ml, 40.22?±?13.76%, 26.79?±?15.47%, 36.41?±?21.66% and 55.25?±?11.99%, respectively. The mean seminal parameter values were significantly lower (p?<?0.001) in infertile as compared to fertile men, except semen volume.Conclusions
Semen parameters in Indian men have declined with time and the deterioration is quantitatively higher in the infertile group. The study also provides reference values for semen parameters in Indian men.189.
β-D-galactosidase (EC 3.2.1.23) fromLactobacillus bulgaricus (1373) was immobilized by entrapment in a Polyacrylamide gel lattice. The enzymatic properties of the immobilized β-galactosidase
were compared with those of the native enzyme. The temperature and pH optima were not affected by the immobilization. After
entrapment of the enzyme no significant change was observed in its thermostability. The pH stability of the immobilized enzyme
was higher than that of the native enzyme on the acidic side. TheK
m values for the immobilized and native β-galactosidase with both lactose ando-nitrophenyl-β-D-galactoside as substrates were comparable. The immobilized enzyme could be repeatedly used 12 times without
any loss of activity. No loss in the activity of the immobilized β-galactosidase was found after its storage for 30 days at
4°C and for 20 days at 25°C. 相似文献
190.