全文获取类型
收费全文 | 1249篇 |
免费 | 121篇 |
出版年
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 29篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 28篇 |
2017年 | 28篇 |
2016年 | 35篇 |
2015年 | 41篇 |
2014年 | 45篇 |
2013年 | 77篇 |
2012年 | 72篇 |
2011年 | 86篇 |
2010年 | 38篇 |
2009年 | 37篇 |
2008年 | 47篇 |
2007年 | 76篇 |
2006年 | 46篇 |
2005年 | 39篇 |
2004年 | 52篇 |
2003年 | 33篇 |
2002年 | 31篇 |
2001年 | 36篇 |
2000年 | 30篇 |
1999年 | 25篇 |
1998年 | 18篇 |
1997年 | 10篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 26篇 |
1991年 | 28篇 |
1990年 | 26篇 |
1989年 | 26篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1973年 | 7篇 |
1972年 | 10篇 |
1971年 | 9篇 |
1966年 | 7篇 |
排序方式: 共有1370条查询结果,搜索用时 15 毫秒
81.
S. Prakash P. B. Kirti S. R. Bhat K. Gaikwad V. D. Kumar V. L. Chopra 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(3):488-492
A cytoplasmic male-sterility system has been developed in mustard (Brassica juncea) following repeated backcrossings of the somatic hybrid Moricandia arvensis (2n=28, MM)+B. juncea (2n=36, AABB), carrying mitochondria and chloroplasts from M. arvensis, to Brassica juncea. Cytoplasmic male-sterile (CMS) plants are similar to normal B. juncea; however, the leaves exhibit severe chlorosis resulting in delayed flowering. Flowers are normal with slender, non-dehiscent
anthers and excellent nectaries. CMS plants show regular meiosis with pollen degeneration occurring during microsporogenesis.
Female fertility was normal. Genetic information for fertility restoration was introgressed following the development of a
M. arvensis monosomic addition line on CMS B. juncea. The additional chromosome paired allosyndetically with one of the B. juncea bivalents and allowed introgression. The putative restorer plant also exhibited severe chlorosis similar to CMS plants but
possessed 89% and 73% pollen and seed fertility, respectively, which subsequently increased to 96% and 87% in the selfed progeny.
The progeny of the cross of CMS line with the restorer line MJR-15, segregated into 1 fertile : 1 sterile. The CMS (Moricandia) B. juncea, the restorer (MJR-15), and fertility restored F1 plants possess similar cytoplasmic organellar genomes as revealed by ‘Southern’ analysis.
Received: 17 September 1997 / Accepted: 18 February 1998 相似文献
82.
Ratan V. Bhat Thomas M. Engber James P. Finn Elizabeth J. Koury Patricia C. Contreras Matthew S. Miller Craig A. Dionne Kevin M. Walton 《Journal of neurochemistry》1998,70(2):558-571
Abstract: In vitro studies indicate that p42/p44MAPK phosphorylate both nuclear and cytoplasmic proteins. However, the functional targets of p42/p44MAPK activation in vivo remain unclear. To address this question, we localized activated p42/p44MAPK in hippocampus and cortex and determined their signaling effects after electroconvulsive shock treatment (ECT) in rats. Phosphorylated p42/p44MAPK content increased in the cytoplasm of hippocampal neurons in response to ECT. Consistent with this cytoplasmic localization, inhibition of ECT-induced p42/p44MAPK activation by the extracellular signal-regulated kinase kinase inhibitor PD098059 blocked phosphorylation of the cytoplasmic protein microtubule-associated protein 2c (MAP2c), but failed to inhibit the induction of the nuclear protein c-Fos in response to ECT. In contrast to hippocampal neurons, cortical neurons exhibited an increase in amount of phosphorylated p42/p44MAPK in both the nucleus and cytoplasm after ECT. Accordingly, PD098059 blocked the induction of Fos-like immunoreactivity in the nuclei of cortical neurons as well as MAP2c phosphorylation in the cytoplasm. Our data indicate that both nuclear and cytoplasmic substrates can be activated by p42/p44MAPK in vivo. However, the functional targets of p42/p44MAPK signaling depend on the precise location of p42/p44MAPK within different subcellular compartments of brain regions. These results indicate unique functional pathways of p42/p44MAPK -mediated signal transduction within different brain regions in vivo. 相似文献
83.
Milica D olovi GM Jankovi RB olovi Vesna M Martinovi-emeriki 《Cancer immunology, immunotherapy : CII》1998,15(4):286-288
A case of primary nonsecretory plasmacytoma of the spleen is reported. On laparotomy and splenectomy a 920 g spleen was removed,
measuring 16×14×6 cm. The cut surface of the entire spleen showed that the tumour occupied most of the splenic tissue. A bone
marrow aspirate and trephine, skeletal survey showed no signs of myeloma. Biopsy of the liver and regional lymph nodes was
normal. Immunocytochemistry of the splenic tumour showed positivity for pan-B and plasma cell markers. After splenectomy the
patient was treated with chemotherapy according to protocol VBCMP (M2). 相似文献
84.
A suitable method for the selective isolation of catechol-cleaving yeasts from coir rets has been worked out. The yeast strains, all belonging toDebaryomyces hansenii, were found to demand biotin as an essential vitamin. The organism has the ability to grow on catechol, phenol and some related compounds as sole source of carbon. It tolerates 0.4% catechol and 0.26% phenol. Evidence was obtained that the catechol-cleaving enzyme of the isolates is a pyrocatechase. Some properties of the cell-free catechol oxygenase are described. 相似文献
85.
Role of Pectinolytic Yeasts in the Degradation of Mucilage Layer of Coffea robusta Cherries 下载免费PDF全文
Pectinolytic yeasts, Saccharomyces marxianus, S. bayanus, S. cerevisiae var. ellipsoideus, and Schizosaccharomyces sp., predominated in the natural fermentation of coffee cherries of Coffea robusta variety grown in Chikmagalur district of Mysore State, India. These yeast species were found on the cherry surfaces, and evidence was adduced to show that the natural fermentation of coffee was the result of activity of microflora from the cherry surface itself rather than that of flora of air or water. Incorporation of pure cultures of Saccharomyces species was shown to aid the process when a mixture of all three species was used. An enzyme preparation from the Saccharomyces species was observed to hasten the mucilage-layer degradation. 相似文献
86.
Shanker Bhat Sullia 《Plant and Soil》1973,39(1):197-200
Summary The effects of root exudates and extracts of Cassia tora L. and Crotalaria medicaginea Lamk., on some dominant rhizosphere fungi isolated from the plants were studied. Root extracts induced a high degree of stimulation in rate of growth of a majority of the fungi tested. Root exudates caused only a marginal effect which was positive on all the fungi except Trichoderma lignorum which was inhibited by the root exudate of C. medicaginea. 相似文献
87.
Kavitha Shettigar Deepika V. Bhat Kapaettu Satyamoorthy Thokur Sreepathy Murali 《Folia microbiologica》2018,63(1):115-122
The genes encoding aminoglycoside resistance in Enterococcus faecalis may promote collateral aminoglycoside resistance in polymicrobial wounds. We studied a total of 100 diabetic foot ulcer samples for infection and found 60 samples to be polymicrobial, 5 to be monomicrobial, and 35 samples to be culture negative. A total of 65 E. faecalis isolates were screened for six genes coding for aminoglycoside resistance, antibiotic resistance patterns, and biofilm production. Infectious Diseases Society of America/International Working Group on the Diabetic Foot system was used to classify the wound ulcers. Majority of the subjects with culture-positive wound were recommended conservative management, while 14 subjects underwent amputation. Enterococcal isolates showed higher resistance for erythromycin, tetracycline, and ciprofloxacin. Isolates from grade 3 ulcer showed higher frequency of aac(6′)-Ie-aph(2″)-Ia, while all the isolates were negative for aph(2″)-Ib, aph(2″)-Ic, and aph(2″)-Id. The isolates from grade 3 ulcers showed higher resistance to aminoglycosides as well as teicoplanin and chloramphenicol. All the 39 biofilm producers were obtained from polymicrobial wound and showed higher resistance when compared to biofilm non-producers. Higher frequency of isolates carrying aac(6′)-Ie-aph(2″)-Ia in polymicrobial community showing resistance to key antibiotics suggests widespread distribution of aminoglycoside-resistant E. faecalis and their role in worsening diabetic foot ulcers. 相似文献
88.
Inapakurti Jaikishan Passoupathy Rajendrakumar Krishna Hariprasanna B. Venkatesh Bhat 《Plant Molecular Biology Reporter》2018,36(3):418-428
Relative expression levels of selected genes from the Heterosis-Related Gene Database exhibiting more than 90% homology with sorghum were studied in hybrids and their respective parental lines for a better understanding on the molecular basis of heterosis. A high (27A × RS 673) and a low heterotic hybrid (7A × CB 26) of sorghum along with their parental lines were used for this purpose. Twenty (15 maize and 5 rice) genes exhibiting more than 90% homology with that of sorghum were identified. The maize genes ZmHG13, ZmHG16, and ZmhG19 exhibited more than fourfold increase over the male parent (RS 673) of high heterotic hybrid during booting stage, which started decreasing during flowering stage. Similarly, the rice genes OsHG1 and OsHG12 recorded >?2.5-fold increase. However, these genes recorded less than twofold increase during the same stage of the plant in the low heterotic hybrid. Notably, among the genes that exhibited higher expression in the highly heterotic hybrid were those coding for proteins, which were known to play crucial roles in the manifestation of heterosis in plants. 相似文献
89.
90.
Yogendra Khedikar Manish K. Pandey V. Sujay Sube Singh Spurthi N. Nayak Henry W. Klein-Gebbinck Cholin Sarvamangala Ganapati Mukri Vanika Garg Hari D. Upadhyaya H. L. Nadaf M. V. C. Gowda Rajeev K. Varshney Ramesh S. Bhat 《Molecular breeding : new strategies in plant improvement》2018,38(1):7
An effort was made in the present study to identify the main effect and epistatic quantitative trait locus (QTL) for the morphological and yield-related traits in peanut. A recombinant inbred line (RIL) population derived from TAG 24 × GPBD 4 was phenotyped in seven environments at two locations. QTL analysis with available genetic map identified 62 main-effect QTLs (M-QTLs) for ten morphological and yield-related traits with the phenotypic variance explained (PVE) of 3.84–15.06%. Six major QTLs (PVE >?10%) were detected for PLHT, PPP, YPP, and SLNG. Stable M-QTLs appearing in at least two environments were detected for PLHT, LLN, YPP, YKGH, and HSW. Five M-QTLs governed two traits each, and 16 genomic regions showed co-localization of two to four M-QTLs. Intriguingly, a major QTL reported to be linked to rust resistance showed pleiotropic effect for yield-attributing traits like YPP (15.06%, PVE) and SLNG (13.40%, PVE). Of the 24 epistatic interactions identified across the traits, five interactions involved six M-QTLs. Three interactions were additive × additive and remaining two involved QTL × environment (QE) interactions. Only one major M-QTL governing PLHT showed epistatic interaction. Overall, this study identified the major M-QTLs for the important productivity traits and also described the lack of epistatic interactions for majority of them so that they can be conveniently employed in peanut breeding. 相似文献