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101.
N-carboxyanhydride of γ-benzyl-l-glutamate was polymerized using the potassium salt of the non-ionic surfactant Triton X-100, octylphenoxypolyethoxyethanol, as the initiator. N.m.r. spectra revealed the presence of the initiator moiety in the polymer. The surfactant bound polypeptides with a degree of polymerization of 21 and 26 had excellent solubility in several non-aqueous solvents as compared to the homopolypeptide poly-γ-benzyl-l-glutamate (PBLG). The circular dichroic profiles of the polymers in the helicogenic solvents trifluoroethanol and trimethyl phosphate were helical. I.r. spectra of films of the polymers also indicated α-helical conformation for the peptide block. X-ray diffraction data, on the other hand, showed along with a spacing corresponding to the hexagonal packing of helices, a 22 Å spacing, indicative of a new kind of long range order not observed with the homopoly-γ-benzyl-l-glutamate. Again, the polymers formed with facility mesophases in various solvents at concentrations, unlike PBLG, as low as 5–8% (w/v). 相似文献
102.
103.
The band patterns of zein polypeptides were determined for many commercial inbred corn lines and maize stocks using isofocusing in agarose gels and sodium dodecyl sulfate (SDS)-urea gels. Each inbred line or homozygous maize strain genotype has a distinct zein profile which has been catalogued according to the distance of charge migration and molecular weight (kilodaltons). Several zein polypeptides were mapped to chromosomes 4 and 10 with the use of reciprocal translocations. The mapping of at least two polypeptides on distal 4L and 10L had not been previously reported. The general methods used in the present research will permit the mapping of all the zein polypeptides to chromosomal sites.Pioneer Hi-Bred International provided financial support. 相似文献
104.
A cDNA clone (WL : AGA.1) encoding wheat leaf ADP-glucose pyrophosphorylase has been isolated from a gt11 expression library, by immunological screening with anti-spinach leaf ADP-glucose pyrophosphorylase serum. The WL : AGA.1 cDNA is 948 bp long and contains approximately 55% of the complete wheat leaf ADP-glucose pyrophosphorylase mRNA sequence, estimated from Northern blot experiments. A wheat endosperm cDNA library was subsequently constructed in gt11 and six clones hybridising to the cDNA insert of clone WL : AGA.1 were isolated. The longest of these wheat endosperm ADP-glucose pyrophosphorylase cDNAs, clone WE : AGA.7, is nearly full-length (1798 bp), indicated by Northern blot analysis of wheat endosperm mRNA and nucleotide sequence analysis.Southern hybridisation analysis and restriction enzyme mapping indicated that the wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs and genes are members of two distinct gene families. In addition, restriction enzyme mapping revealed polymorphism in the wheat endosperm ADP-glucose pyrophosphorylase cDNAs, indicating the existence of at least two wheat endosperm ADP-glucose pyrophosphorylase gene sub-families.Subsequent nucleotide sequence analysis indicates that there is approximately 55% identity between wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs. In contrast, members of each sub-family of endosperm cDNA, represented by clones WE : AGA.3 and WE : AGA.7, are 96% identical. 相似文献
105.
Summary The yolk proteins stored in Drosophila, oocytes for utilisation during embryogenesis are an ideal system for studying the regulation of gene expression during development. The 3 major polypeptides found in yolk in D. melanogaster are synthesised in the fat body and ovarian follicle cells and selectively accumulated by the oocyte during vitellogenesis. In order to understand more about their regulation and the mechanism of uptake, studies on other species are necessary.Three yolk polypeptides have previously been identified in the D. melanogaster sibling species (D. melanogaster, D. simulans, D. mauritiana, D. erecta, D. teissieri, D. orena and D. yakuba). In D. melanogaster three genes located on the X chromosome are known to code for these yolk polypeptides. in this study genomic Southern transfers and in situ hybridisation experiments were carried out on the sibling species. Using the three cloned yolk protein genes from D. melanogaster, homologous sequences could be detected in the sibling species. It is suggested that three yolk protein genes occur in each of these species, all being located on the X chromosome, and that two of the genes are very closely linked in these same species. Yolk protein gene-homologous DNA sequences have also been identified in two more distantly related species D. funebris and D. virilis. 相似文献
106.
Cristiano Chiarabelli Davide De Lucrezia 《Origins of life and evolution of the biosphere》2007,37(4-5):357-361
Starting from the statement that no reliable methods are known to produce high molecular weight polypeptides under prebiotic
conditions, a possible approach, at least to understand the differences between extant proteins and the possible large number
of never born proteins, could be biological. Using the phage display method a large library of totally random amino acidic
sequences was obtained. Consequently, different experiments to directly consider the frequency of stable folds were performed,
and the interesting results obtained from such new approach are discussed in terms of contingency, contributing to the discussion
on the selection mechanism of extant proteins.
Presented at the International School of Complexity – 4th Course: Basic Questions on the Origins of Life; “Ettore Majorana”
Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006. 相似文献
107.
108.
The polypeptides in the leaf blades, petioles and apices from photoinduced and noninduced Xanthium strumarium L. were compared by two dimensional gel-electrophoresis. A 15 kDa and a 16 kDa polypeptide were detected in gels of the leaf blade from noninduced, but not from induced, plants. Similarly, an acidic 9 kDa polypeptide was detected in the apices from noninduced plants, but not in apices from induced plants. Both the apices and petioles from noninduced plants showed a 34 kDa polypeptide which was absent in tissues from induced plants. Thus, the disappearence of identifiable polypeptides from photoinduced tissues may be associated with the photoinductive short-day treatment that leads to flowering. 相似文献
109.
110.
Yoshiki Yasukochi Jun Sakuma Ichiro Takeuchi Kimihiko Kato Mitsutoshi Oguri Tetsuo Fujimaki Hideki Horibe Yoshiji Yamada 《Genomics》2019,111(1):34-42
Recent genome-wide association studies identified genetic variants that confer susceptibility to type 2 diabetes mellitus (T2DM). However, few longitudinal genome-wide association studies of this metabolic disorder have been reported to date. Therefore, we performed a longitudinal exome-wide association study of T2DM, using 24,579 single nucleotide polymorphisms (SNPs) and repeated measurements from 6022 Japanese individuals. The generalized estimating equation model was applied to test relations of SNPs to three T2DM-related parameters: prevalence of T2DM, fasting plasma glucose level, and blood glycosylated hemoglobin content. Three SNPs that passed quality control were significantly (P < 2.26 × 10? 7) associated with two of the three T2DM-related parameters in additive and recessive models. Of the three SNPs, rs6414624 in EVC and rs78338345 in GGA3 were novel susceptibility loci for T2DM. In the present study, the SNP of GGA3 was predicted to be a genetic variant whose minor allele frequency has recently increased in East Asia. 相似文献