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61.
Jia EZ Wang J Yang ZJ Zhu TB Wang LS Chen B Cao KJ Huang J Ma WZ 《Molecular and cellular biochemistry》2008,307(1-2):31-39
Objective To test the hypothesis that the identification of mutation in the carboxypeptidase E (CPE) gene which leads to marked hyperproinsulinaemia
is consistent with a possible role for mutations in CPE in the development of coronary heart disease. Methods The study subjects consisted of 51 consecutive patients (34 males and 17 females) who will undergo coronary angiography for
suspected or known coronary atherosclerosis. Coronary heart disease (CHD) was defined as having a luminal diameter stenosis
≥50% in at least one of three major coronary arteries by coronary angiography or based on the Rose Questionnaire. The insulin
and proinsulin level were measured using highly sensitive two-site sandwich ELISA methods. Screening for mutations of the
eight exons of the CPE gene was performed by polymerase chain reaction followed by bidirectional sequencing. Results We scanned eight exons and exon–intron junctional region. Overall, we found 12 distinct variants in the intron region and
three variants in the exon region. Among the 15 variants, 10 mutations were rare. The further explored study reveal that the
above five non-rare variants would not affect the level of glucose, insulin, and proinsulin. However, the results suggest
that the prevalence of the coronary heart disease was significant difference between the wild type group and mutant type group
according to the A4545G (P = 0.020). The results from the logistic regression reveal that the subjects with the CPE mutation of A4545G, the odds ratio
for the coronary heart disease was 0.196 (95% CI: 0.046 to 0.830, P = 0.027). Conclusions In the present study, the mutation of CPE gene would not affect the level of glucose, insulin, and proinsulin. The hypothesis
of a possible role for mutations in CPE in the development of coronary heart disease needs further study. 相似文献
62.
A biofilter treating alkylbenzene vapors was characterized for its optimal running conditions and kinetic parame-ters. Kinetics
of the continuous biofilter were compared to batch kinetic data obtained with biofilm samples as well as with defined microbial
consortia and with pure culture isolates from the biofilter. Both bacteria and fungi were present in the bioreactor. Five
strains were isolated. Two bacteria, Bacillus and Pseudomonas, were shown to be dominant, as well as a Trichosporon strain
which could, however, hardly grow on alkylbenzenes in pure culture. The remaining two strains were most often overgrown by
the other three organisms in liquid phase batch cultures μ
max, KS, KI values and biodegradation rates were calculated and compared for the difterent mixed and pure cultures. Since filter bed
acidification was observed during biofiltration studies reaching a pH of about 4, experiments were also undertaken to study
the influence of pH on performance of the different cultures. Biodegradation and growth were possible in all cases, over the
pH range 3.5–7.0 at appreciable rates, both with mixed cultures and with pure bacterial cultures. Under certain conditions,
microbial activity was even observed in the presence of alkylbenzenes down to pH 2.5 with mixed cultures, which is quite unusual
and explains the ability of the present biocatalyst to remove alkylbenzenes with high efficiency in biofilters under acidic
conditions. 相似文献
63.
Both humoral and cell-mediated immune responses to the synthetic helical hapten-carrier conjugate poly-Glu-Tyr-Lys(TNP)-(Glu-Tyr-Ala)5 were found to be linked to the major histocompatibility locus in mice and guinea pigs. The responder mouse strains (H-2d haplotype) showed a primary IgM response with an IgG component appearing after the secondary immunization. The antibody response was accompanied by a positive DTH reaction in responder strains. Nonresponder mice (H-2b or H-2k haplotypes) showed neither IgM nor IgG antibodies and the DTH reaction was negative. Administration of the antigen as a complex with an immunogenic carrier was not effective in inducing a response in nonresponder mice. In guinea pig studies, it was found that strain 2 animals were able to mount an antibody response against the TNP-hapten and a DTH response against the polypeptide backbone. Strain 13 animals gave no anti-TNP antibodies at the lower dose levels and DTH activity was entirely negative for all doses of immunizing antigen. Replacement of the TNP hapten by the arsanilazo dipeptide derivative, BOC-gly-ARA-tyrosine, converted the nonresponder strain 13 guinea pigs into complete responders showing antibody and DTH reactions to both the hapten and the polypeptide backbone. 相似文献
64.
Molecular phylogenetic analyses of mullets (Mugilidae, Mugiliformes) based on two mitochondrial genes 总被引:1,自引:0,他引:1
E. Fraga H. Schneider M. Nirchio E. Santa-Brigida L. F. Rodrigues-Filho I. Sampaio 《Zeitschrift fur angewandte Ichthyologie》2007,23(5):598-604
Molecular phylogenetic studies are very scarce for the Mugilidae family; the present analysis using DNA sequences of the mitochondrial 16S rRNA and cytochrome b genes is the first study involving Brazilian mugilids. The results corroborate the monophyly of Mugil and are elucidative for the taxonomy of Brazilian mugilids. Mugil curema is clearly divided into two genetically distinct taxa, M. curema type I being closer related to Mugil hospes and the true M. curema (type II) grouping significantly with M. incilis. The results also suggest that Mugil liza and Mugil platanus should be treated as a single species or even populations of Mugil cephalus. 相似文献
65.
Maria José Lorenzo Alonso Adela Bermejo Barrera José Angel Cocho de Juan José María Fraga Bermúdez Pilar Bermejo Barrera 《Journal of trace elements in medicine and biology》2005,19(1):49-54
A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood. 相似文献
66.
Qualitative and quantitative differences in carrageenan composition of gametophytes of the rhodophyte Mastocarpus stellatus (Gigartinales) were observed in this study. Carrageenans in gametophytes belong to the kappa family (κ-, ι-, ν-, μ-carrageenan). The dominant fractions were κ- and ι-carrageenan (more than 80 % of the total carrageenans). Mean total carrageenan content in gametophytes was of 37.32?±?1.21 % DW. Spatial and seasonal variations were observed, mainly related to changes on environmental and oceanographic factors and the role of carrageenans in adapting the fronds to these changes. Maximum values in carrageenan content were observed for San Román (Biscay Bay) in May and for Laxe and Mougás (Atlantic coast) in June. The results of this study indicated that spatial differences in carrageenan content were due to interactions of different factors, rather than the effect of a single factor. Fronds from San Román had higher carrageenan content (43.23?±?1.87 % DW) than those collected at two sites of the Atlantic coast, Mougás and Laxe (32.20?±?1.14 % DW). San Román is exposed to the open sea, windy and oriented to the north, and the water temperature is higher in summer than in the Atlantic coast. However, seasonal variations in carrageenan content resulted to be more related to other factors directly correlated with the input of energy in the ecosystems (irradiance, sunshine hours and insolation). Thus, carrageenan content began to increase in early spring when the number of sunlight hours increased. Maximum values were reached in late spring or early summer, just before maximum values of irradiance and air temperature were achieved. 相似文献
67.
Hugo Fraga Joan-Josep Bech-Serra Francesc Canals Gabriel Ortega Oscar Millet Salvador Ventura 《The Journal of biological chemistry》2014,289(14):9852-9864
Mia40-catalyzed disulfide formation drives the import of many proteins into the mitochondria. Here we characterize the oxidative folding of Cox19, a twin CX9C Mia40 substrate. Cox19 oxidation is extremely slow, explaining the persistence of import-competent reduced species in the cytosol. Mia40 accelerates Cox19 folding through the specific recognition of the third Cys in the second helical CX9C motif and the subsequent oxidation of the inner disulfide bond. This renders a native-like intermediate that oxidizes in a slow uncatalyzed reaction into native Cox19. The same intermediate dominates the pathway in the absence of Mia40, and chemical induction of an α-helical structure by trifluoroethanol suffices to accelerate productive folding and mimic the Mia40 folding template mechanism. The Mia40 role is to funnel a rough folding landscape, skipping the accumulation of kinetic traps, providing a rationale for the promiscuity of Mia40. 相似文献
68.
A Matter of Scale: Historical and Environmental Factors Structure Anuran Assemblages from the Upper Madeira River,Amazonia 下载免费PDF全文
Randolpho G. Dias‐Terceiro Igor Luis Kaefer Rafael de Fraga Maria Carmozina de Araújo Pedro Ivo Simões Albertina P. Lima 《Biotropica》2015,47(2):259-266
Biogeographical history and current ecological interactions have usually been addressed separately to explain the spatial distribution of patterns of biodiversity. In this study, we evaluated the integrated effects of biogeographical and environmental factors in structuring the diurnal amphibian anuran assemblages of the upper Madeira River, southwestern Amazonia. We used a sampling design involving 98 standardized units, distributed across seven locations covering both banks of the river's course in the state of Rondônia, Brazil. We conducted searches for frogs in three campaigns between February 2010 and February 2011, aiming to: (1) evaluate the effect of the Madeira River as a biogeographic barrier at the species‐assemblage level, and (2) test the influence of seven environmental variables (vegetation structure, vegetation cover, soil nutrients, soil structure, slope, elevation, and distance from the river bank) on the spatial structure of the frog assemblages, separately on each riverbank. Thirteen species of diurnal frogs were recorded, six of which were restricted to one of the river margins. Multivariate analysis of variance indicated a significant effect of the river as a barrier. Multiple regression analyses suggested that the environmental variables structuring frog assemblages differ on either side of the river. We found that both historical elements (on a regional scale) and environmental factors (at a local scale) shaped the occurrence and distribution of frog species in the study area. 相似文献
69.
70.
Luciano F. Drager Heno F. Lopes Cristiane Maki-Nunes Ivani C. Trombetta Edgar Toschi-Dias Maria Janieire N. N. Alves Raffael F. Fraga Jonathan C. Jun Carlos E. Negr?o Eduardo M. Krieger Vsevolod Y. Polotsky Geraldo Lorenzi-Filho 《PloS one》2010,5(8)