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101.
Ueno K  Takai A 《Cytobios》2000,103(402):7-15
Three Xyrichthys fish (Labridae, Perciformes), X. pavo, X. dea, and X. twistii, were cytogenetically studied. X. pavo and X. dea had 2n = 44 chromosomes, which were all acrocentric. X. twistii had 2n = 22 chromosomes consisting of eighteen meta- and submetacentric and four acrocentric chromosomes. The cellular DNA contents of X. pavo and X. twistii measured using flow cytometry were nearly equal. These results suggest that the karyotype of X. twistii evolved by decreasing the number of chromosomes by fusion events, probably Robertsonian fusion. Cytogenetic relationships among the three species were surmized on the basis of features on the karyotypes and the NOR locations. A large gap in the chromosome number between 2n = 44 and 2n = 22 is an interesting feature related to the process of chromosome evolution.  相似文献   
102.
We investigated the levels of the angiotensin II-forming enzymes, chymase and angiotensin converting enzyme (ACE), in dog grafted veins, and studied the effect of an angiotensin II type 1 receptor antagonist, L-158,809, on vascular proliferation in the grafted veins. The right external jugular vein was grafted to the ipsilaterial carotid artery. In the group treated with L-158,809, the drug (10 mg/kg per day, p.o.) were administered orally from 7 days before the operation to 28 days after it, while the others were administrated placebo. In the placebo-treated group, the chymase activity in the grafted veins was increased about 10-fold and the ACE activity was doubled. The areas of intima and media were significantly increased in the grafted veins in the placebo-treated group. L-158,809 significantly reduced the intimal area of the grafted veins. An angiotensin II receptor antagonist, L-158,809, prevented the vascular proliferation in the grafted veins, and the development of the proliferation may depend on activation of local angiotensin II formation.  相似文献   
103.
Methods for the preparation of an Escherichia coli tRNA mixture lacking one or a few specific tRNA species can be the basis for future applications of cell-free protein synthesis. We demonstrate here that virtually a single tRNA species in a crude E. coli tRNA mixture can be knocked out by an antisense (complementary) oligodeoxyribonucleotide. One out of five oligomers complementary to tRNAAsp blocked the aspartylation almost completely, while minimally affecting the aminoacylation with other 13 amino acids tested. This `knockout' tRNA behaved similarly to the untreated tRNA in a cell-free translation of an mRNA lacking Asp codons.  相似文献   
104.
The Rho subfamily of the Rho small G protein family (Rho) regulates formation of stress fibers and focal adhesions in many types of cultured cells. In moving cells, dynamic and coordinate disassembly and reassembly of stress fibers and focal adhesions are observed, but the precise mechanisms in the regulation of these processes are poorly understood. We previously showed that 12-O-tetradecanoylphorbol-13-acetate (TPA) first induced disassembly of stress fibers and focal adhesions followed by their reassembly in MDCK cells. The reassembled stress fibers showed radial-like morphology that was apparently different from the original. We analyzed here the mechanisms of these TPA-induced processes. Rho inactivation and activation were necessary for the TPA-induced disassembly and reassembly, respectively, of stress fibers and focal adhesions. Both inactivation and activation of the Rac subfamily of the Rho family (Rac) inhibited the TPA-induced reassembly of stress fibers and focal adhesions but not their TPA-induced disassembly. Moreover, microinjection or transient expression of Rab GDI, a regulator of all the Rab small G protein family members, inhibited the TPA-induced reassembly of stress fibers and focal adhesions but not their TPA-induced disassembly, indicating that, furthermore, activation of some Rab family members is necessary for their TPA-induced reassembly. Of the Rab family members, at least Rab5 activation was necessary for the TPA-induced reassembly of stress fibers and focal adhesions. The TPA-induced, small G protein-mediated reorganization of stress fibers and focal adhesions was closely related to the TPA-induced cell motility. These results indicate that the Rho and Rab family members coordinately regulate the TPA-induced reorganization of stress fibers and focal adhesions that may cause cell motility.  相似文献   
105.
Protein phosphatase 1γ, a serine/threonine phosphatase, is a metalloprotein that coordinates two Mn2+ in the active site when expressed in Escherichia coli in a buffer containing MnCl2. Herein, we report on the oxidatively induced copper for manganese exchange in protein phosphatase 1γ, thus enabling firm confirmation of the four histidine (His) amino acid residues (His66, His125, His173, and His248) involved in metal coordination. By exchanging manganese with copper the oxidation yields for the peptides increased dramatically, thus simplifying detection of the oxidized peptides and analysis of the oxidation sites within the oxidized peptides. We also found that when copper was added during the oxidation process a new metal coordination center was formed at cysteine 39, 105, 140, and 155.  相似文献   
106.
107.
BackgroundPollen released by allergenic members of the botanically unrelated families of Asteraceae and Cupressaceae represent potent elicitors of respiratory allergies in regions where these plants are present. As main allergen sources the Asteraceae species ragweed and mugwort, as well as the Cupressaceae species, cypress, mountain cedar, and Japanese cedar have been identified. The major allergens of all species belong to the pectate lyase enzyme family. Thus, we thought to investigate cross-reactivity pattern as well as sensitization capacities of pectate lyase pollen allergens in cohorts from distinct geographic regions.MethodsThe clinically relevant pectate lyase pollen allergens Amb a 1, Art v 6, Cup a 1, Jun a 1, and Cry j 1 were purified from aqueous pollen extracts, and patients´ sensitization pattern of cohorts from Austria, Canada, Italy, and Japan were determined by IgE ELISA and cross-inhibition experiments. Moreover, we performed microarray experiments and established a mouse model of sensitization.ResultsIn ELISA and ELISA inhibition experiments specific sensitization pattern were discovered for each geographic region, which reflected the natural allergen exposure of the patients. We found significant cross-reactivity within Asteraceae and Cupressaceae pectate lyase pollen allergens, which was however limited between the orders. Animal experiments showed that immunization with Asteraceae allergens mainly induced antibodies reactive within the order, the same was observed for the Cupressaceae allergens. Cross-reactivity between orders was minimal. Moreover, Amb a 1, Art v 6, and Cry j 1 showed in general higher immunogenicity.ConclusionWe could cluster pectate lyase allergens in four categories, Amb a 1, Art v 6, Cup a 1/Jun a 1, and Cry j 1, respectively, at which each category has the potential to sensitize predisposed individuals. The sensitization pattern of different cohorts correlated with pollen exposure, which should be considered for future allergy diagnosis and therapy.  相似文献   
108.
109.
Wheat RNA ligase contains 5′-hydroxyl kinase, 2′,3′-cyclic phosphate 3′-phosphodiesterase, and 5′-phosphate 2′-phosphate-3′-hydroxyl RNA ligase activities in a 110-kDa polypeptide. Taking advantage of a wheat cell-free protein production system, we prepared various fragments containing a part of the enzyme. The method allowed us to check the activities of the fragments rapidly, eliminating the time-consuming cloning and sequencing steps for the expression of the fragment proteins. The results showed that each of the three activities can be assigned to a non-overlapping domain that does not require the presence of the other part(s) of the enzyme for its activity. This contrasts to the case of yeast tRNA ligase, in which the central kinase domain has been suggested to require to be tethered to one of the flanking domains for its activity.  相似文献   
110.
At-risk female pigs were defined as females having characteristics of at least one of the four subgroups: females with reservices, lactation length (LL) 0-13 days, weaning-to-first-mating interval (WMI) > or = 8 days, and abortion records. These females may have suboptimal reproductive performance. This study examined reproductive performance in at-risk females, and the relationships between at-risk females, parity, season of mating, and the four subgroups. From 117 farms, 102,494 parity records were categorized into at-risk females and non-at-risk females. Statistical mixed models were used to analyze reproductive performance. Of the 102,494 records, 19.6% were at-risk females. At-risk females had at least 11.1% lower farrowing rates than non-at-risk females among all parities and seasons of mating (P<0.05). As parity increased from 1 to > or = 6, farrowing rate in at-risk females decreased from 74.1 to 62.9%, while the farrowing rate in non-at-risk females decreased from 87.3 to 82.0% (P<0.05). There was no difference in the number of pigs born alive between at-risk females and non-at-risk females (P=0.810). Females at Parity 1 and those that mated during summer had the highest proportion of becoming at-risk females (P<0.001). Gilts and sows with abortion records had at least 39.3% lower farrowing rates than those with non-abortion records (P<0.001). Among the LL 0-13 days, the farrowing rate was below 70% regardless of WMI. Monitoring and reducing at-risk females is an opportunity for producers to improve herd productivity.  相似文献   
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