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31.
32.
Interest in the use of low-copy nuclear genes for phylogenetic analyses of
plants has grown rapidly, because highly repetitive genes such as those
commonly used are limited in number. Furthermore, because low- copy genes
are subject to different evolutionary processes than are plastid genes or
highly repetitive nuclear markers, they provide a valuable source of
independent phylogenetic evidence. The gene for granule-bound starch
synthase (GBSSI or waxy) exists in a single copy in nearly all plants
examined so far. Our study of GBSSI had three parts: (1) Amino acid
sequences were compared across a broad taxonomic range, including grasses,
four dicotyledons, and the microbial homologs of GBSSI. Inferred structural
information was used to aid in the alignment of these very divergent
sequences. The informed alignments highlight amino acids that are conserved
across all sequences, and demonstrate that structural motifs can be highly
conserved in spite of marked divergence in amino acid sequence. (2)
Maximum-likelihood (ML) analyses were used to examine exon sequence
evolution throughout grasses. Differences in probabilities among
substitution types and marked among-site rate variation contributed to the
observed pattern of variation. Of the parameters examined in our set of
likelihood models, the inclusion of among-site rate variation following a
gamma distribution caused the greatest improvement in likelihood score. (3)
We performed cladistic parsimony analyses of GBSSI sequences throughout
grasses, within tribes, and within genera to examine the phylogenetic
utility of the gene. Introns provide useful information among very closely
related species, but quickly become difficult to align among more divergent
taxa. Exons are variable enough to provide extensive resolution within the
family, but with low bootstrap support. The combined results of amino acid
sequence comparisons, maximum-likelihood analyses, and phylogenetic studies
underscore factors that might affect phylogenetic reconstruction. In this
case, accommodation of the variable rate of evolution among sites might be
the first step in maximizing the phylogenetic utility of GBSSI.
相似文献
33.
R N Khodanova L S Seslavina N N Golubeva V A Zuyeva O N Kutkova V V Maltseva T I Nikitina 《Journal of hygiene, epidemiology, microbiology, and immunology》1989,33(4):463-469
An efficient method for the treatment of drug allergy was proposed and practically implemented. The method consists in autologous venous blood being lyzed with sterile bidistilled water at a ratio of 5:1 and injected subcutaneously and partially intradermally into the reflexogenic zones of the back 2-3 cm from the spinal column. During the first week of treatment, increasing doses were injected (3 to 10 ml), whereas during the second week the doses decreased from 10 to 3 ml. Following treatment the patients felt better and featured enhanced working ability as well as markedly declined susceptibility to common colds. The most informative immunological indicators were chosen to evaluate the efficiency of therapy. 相似文献
34.
Lectins were extracted from the surface of nitrogen-fixing soil bacteria Azospirillum brasilense Sp7 and from its mutant A. brasilense Sp7.2.3 defective in lectin activity. The ability of lectins to stimulate the rapid formation of hydrogen peroxide related
to increase of oxalate oxidase and peroxidase activity in the roots of wheat seedlings has been demonstrated. The most rapid
induced pathway of hydrogen peroxide formation in the roots of wheat seedlings was the oxalic acid oxidation by oxalate oxidase
which is the effect of lectin in under 10 min in a concentration of 10 μg/ml. The obtained results show that lectins from
Azospirillum are capable of inducing the adaptation processes in the roots of wheat seedlings. 相似文献
35.
Along with a brief review of Lentinula edodes (shiitake mushroom) submerged cultivation history within the framework of important extracellular proteins biosynthesis,
this study contains the authors’ own results. The possibility of regulating the lectin activity of shiitake using the synthetic
components is shown. The time course of lectin production in culture liquid of L. edodes in different media under submerged culture conditions was studied. The activity of agglutinins depended on the ratio between
carbon and nitrogen sources and the pH of the culture medium. A relationship between the chemical composition of nutrient
medium, the activity of extracellular lectins of L. edodes, and the formation of pigmented mycelial film in liquid culture has been found. The formulation of medium, on which the brown
mycelial film appears in several days of submerged cultivation, is proposed. The results obtained make a contribution to the
present notion of biochemical processes that give rise to the occurrence of the aforesaid morphological structure of shiitake.
Finally, two extracellular lectins from the submerged culture of L. edodes have been isolated and purified to homogeneity. Their physicochemical properties and composition have been studied. 相似文献
36.
Along with a brief review of Lentinula edodes (shiitake mushroom) submerged cultivation history within the framework of important extracellular proteins biosynthesis, this study contains the authors’ own results. The possibility of regulating the lectin activity of shiitake using the synthetic components is shown. The time course of lectin production in culture liquid of L. edodes in different media under submerged culture conditions was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and the pH of the culture medium. A relationship between the chemical composition of nutrient medium, the activity of extracellular lectins of L. edodes, and the formation of pigmented mycelial film in liquid culture has been found. The formulation of medium, on which the brown mycelial film appears in several days of submerged cultivation, is proposed. The results obtained make a contribution to the present notion of biochemical processes that give rise to the occurrence of the aforesaid morphological structure of shiitake. Finally, two extracellular lectins from the submerged culture of L. edodes have been isolated and purified to homogeneity. Their physicochemical properties and composition have been studied. 相似文献
37.
Sipina LV Bukurova YA Nikitina IG Krasnov GS Sergeev SA Lisitsyn NA Karpov VL Beresten SF 《Biochemistry. Biokhimii?a》2010,75(9):1148-1152
A modified method of proteome comparative analysis based on preliminary removal of cell structural proteins by extraction
using salt buffer and subsequent separation of extracts by two-dimensional gel electrophoresis was developed. Identification
of differentially expressed proteins by mass spectrometry has revealed three proteins with noticeably increased level of synthesis
in most samples of papillary thyroid tumors compared to normal tissues. An increase in ubiquitin content was found for the
first time. Oncomarker search efficiencies by two-dimensional gel electrophoresis and bioinformatic search were compared. 相似文献
38.
39.
Phenol oxidase activity was detected for the first time in a number of strains belonging to various Azospirillum species. Both extracellular and intracellular activities of laccase, Mn-peroxidase, lignin peroxidase, and tyrosinase were
observed. Extracellular enzymes were found to have higher activity. Significant differences in phenol oxidase activities were
observed between species and strains. 相似文献
40.
For the first time, from the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 +/- 1 kDa, consisting of two subunits of 33-34 kDa each. The lectin is a hydrophilic glycoprotein with the protein : glycan ratio of 3 : 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 microg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repetitive component --> 2)-beta-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfur-containing amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part. 相似文献