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71.
Genetic analyses have contributed to improvements of economically important traits derived from adipose tissue such as fatty acid composition in beef. Elongation of very long chain fatty acids (ELOVL) genes encode for the enzymes that play an important role in elongation of long-chain fatty acids. In this study, we aimed to discover genetic polymorphisms of ELOVL gene family in cattle populations to develop genetic markers. As a result, five synonymous mutations were detected in the coding regions of the ELOVL1, ELOVL2, ELOVL3 and ELOVL5 genes. In addition, six mutations were identified in promoter region of the ELOVL5. Two of five mutations in the promoter region of ELOVL5 were expected to alter the ELOVL5 expression and influence the economic traits, because of the high synteny of the region which was essential for activation of Elovl5 in mouse. Therefore, we performed association analysis between the genotypes and traits and our result revealed that T allele of g.-110T>C in ELOVL5 gene promoter indicated significantly thinner subcutaneous fat thickness (TT, 2.39 cm; CT, 2.35 cm) than that of C allele (CC, 2.68 cm) in a Japanese Black population. Our results suggest that the g.-110T>C is a useful genetic marker for the breeding in beef cattle.  相似文献   
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In pea carrying cyv1, a recessive gene for resistance to Clover yellow vein virus (ClYVV), ClYVV isolate Cl-no30 was restricted to the initially infected cells, whereas isolate 90-1 Br2 overcame this resistance. We mapped the region responsible for breaking of cyv1-mediated resistance by examining infection of cyv1 pea with chimeric viruses constructed from parts of Cl-no30 and 90-1 Br2. The breaking of resistance was attributed to the P3 cistron, which is known to produce two proteins: P3, from the main open reading frame (ORF), and P3N-PIPO, which has the N-terminal part of P3 fused to amino acids encoded by a small open reading frame (ORF) called PIPO in the +2 reading frame. We introduced point mutations that were synonymous with respect to the P3 protein but nonsynonymous with respect to the P3N-PIPO protein, and vice versa, into the chimeric viruses. Infection of plants with these mutant viruses revealed that both P3 and P3N-PIPO were involved in overcoming cyv1-mediated resistance. Moreover, P3N-PIPO quantitatively affected the virulence of Cl-no30 in cyv1 pea. Additional expression in trans of the P3N-PIPO derived from Cl-no30, using White clover mosaic virus as a vector, enabled Cl-no30 to move to systemic leaves in cyv1 pea. Susceptible pea plants infected with chimeric ClYVV possessing the P3 cistron of 90-1 Br2, and which were therefore virulent toward cyv1 pea, accumulated more P3N-PIPO than did those infected with Cl-no30, suggesting that the higher level of P3N-PIPO in infected cells contributed to the breaking of resistance by 90-1 Br2. This is the first report showing that P3N-PIPO is a virulence determinant in plants resistant to a potyvirus.  相似文献   
74.
The aim of the present study was to examine whether zinc (Zn) deficiency augmented the frequency of micronuclei, an indicator of chromosome aberration, and the induction of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of cellular DNA damage derived from oxidative stress, in rat bone marrow cells or not. Both the frequency of micronuclei and the induction of 8-OHdG were significantly increased in rats fed with a Zn-deficient versus a standard diet for 6 weeks (p?<?0.005). The supplementation of Zn with a standard diet for 4 weeks to rats fed with a Zn-deficient diet for 6 weeks restored the enhanced induction of micronuclei and 8-OHdG to levels comparable to those seen in rats fed with a standard diet for 10 weeks, indicating that the shortage of Zn in the body is involved in the induction of micronuclei and 8-OHdG. Again, the membrane-permeable superoxide dismutase mimetic superoxide scavenger, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, treatment (100 μmol/kg, twice a day) for 10 days prior to the termination of dietary treatment reduced the induction of micronuclei and 8-OHdG in rats fed with a Zn-deficient diet for 6 weeks to levels comparable to those in rats fed with a standard diet for 6 weeks, indicating that superoxide radical participates in the induction of micronuclei and 8-OHdG. In fact, the endogenous superoxide scavenger, Cu/Zn superoxide dismutase, was significantly reduced in the bone marrow cells of rats fed with a Zn-deficient diet for 6 weeks when compared to those of rats fed with a standard diet for 6 weeks (p?<?0.005). These observations demonstrate that Zn deficiency elevates the frequency of micronuclei and the induction of 8-OHdG through an increase in the biological action of the superoxide radical. This suggests an increase in carcinogenic initiation resulting from Zn deficiency-induced oxidative stress.  相似文献   
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Five different types of pollen tetrads were detected from the short and long stamens of the male and hermaphrodite flowers of the androdioecious species, Mimosa pigra L. Light (LM) and scanning electron microscopes (SEM) were used in this study to redescribe the pollen forms and to identify the various pollen types encountered. An identification key and relative percentages of these pollen types were also presented. The study showed that the long stamens of the male flowers and those of the hermaphrodite ones have five (I, II, III, IV and V) and two (I and V) pollen types respectively, whereas the short stamens of both male and hermaphrodite flowers have only one pollen type (type I). We report here the first incidence of intra‐specific pollen polymorphism in androdioecious species.  相似文献   
79.
1-Pyrroline-5-carboxylate dehydrogenase was purified and crystallized from Bacillus sphaericus. The crystalline preparation gave a single band on polyacrylamide slab gel electrophoresis. The molecular weight of the enzyme was determined to be about 100,000 by gel filtration. The enzyme consists of two subunits which are identical in molecular weight (50,000), as judged on SDS slab gel electrophoresis. The enzyme shows an optimum pH of 6.5 to 7.0. Its activity was 8.1 times higher with NADP+ than with NAD +, and the enzyme was stabilized by NADP+. The apparent Km values for l-l-pyrroline-5-carboxylate, NADP+ and NAD+ are 4.2 × 10–5m (with NADP+), 9.5 × 10~6m and 2.5 × IO-3 m, respectively. The enzyme reaction is irreversible. A simple method for the determination of l-ornithine involving ornithine ¿-aminotransferase and 1- pyrroline-5-carboxylate dehydrogenase from B. sphaericus was developed. A linear relationship was found between the absorbance at 340 nm and the amount of l-ornithine (50 ~ 400 nmol), and between the fluorescence and the amount of l-ornithine (0.2 ~ 10 nmol).  相似文献   
80.
The degree of racemization in the several activated ester methods of the peptide synthesis was measured in using the critical racemization test, Pro-Val+Pro, with help of gas chromatography. The results were compared with that in the coupling reaction, Leu-Phe+Val, in which no racemization had been reported in the corresponding reaction conditions by F. Weygand et al., when the activated dipeptide esters had been prepared from Z-Leu+Phe-activated esters. The significantly higher racemization was observed in the methods of N-hydroxypiperidine ester and thiophenyl ester, even when the activated dipeptide esters were prepared from Z-Pro+Val-activated esters. On the other hand, almost no racemization was observed in the N-hydroxysuccinimide ester and p-nitrophenyl ester methods. A great extent of the racemization was detected when the activated dipeptide esters were prepared directly from Z-Pro-Val-OH.  相似文献   
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