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931.
932.
Zaprionus indianus is a recent invader in Brazil and was probably introduced from the West Afrotropical zone. So far, studies regarding its
chromosomal polymorphism were limited to India. We found that Brazilian populations were very different from Indian ones.
Five new inversions have been discovered. In(II)A, already described in India, where it is quite common, has also been found in Brazil, where it is very rare. The X-chromosome
has three inversions; In(X)Na, In(X)Ke and In(X)Eg, which are frequent in all Brazilian populations studied. In every case, we observed strong linkage disequilibrium among
these gene arrangements. During the primary collection period (2001–2002), we noticed a significant positive correlation between
the frequency of these inversions and latitude, but this was not confirmed in later investigations. Rearrangement In(IV)EF was also common in all populations, while inversion In(V)B was only found in southern populations. Our data suggest that the founders that recently invaded Brazil were polymorphic
for the six inversions observed. The place of origin might be identified more precisely by investigating West African populations.
In order to facilitate further investigations, we present an updated polytene chromosome photomap, locating the breakpoints
of every inversion observed in Brazilian populations.
Galina Ananina and Cláudia Rohde contributed equally to this work 相似文献
933.
Fungal contamination is a major problem in cell culture, and the antifungal compounds currently in use can affect cultured
cells. Echinocandins are antifungal drugs that inhibit fungal cell wall synthesis by targeting an enzyme that has no counterpart
in mammalian cells. We evaluated whether the echinocandin caspofungin affected the growth or morphology of six murine cell
lines (a macrophage-like cell line (J774.16) and five hybridoma lines), or primary human endothelial cells. The antifungal
did not influence cellular characteristics at concentrations less than 512 μg/ml, while effectively reducing the incidence
of fungal contamination. Also, caspofungin did not affect the production of antibody by hybridoma cells, or alter the cytokine
production of J774.16 cells, although modest increases in IL-4 and IFN-γ occurred upon LPS stimulation. Hence, echinocandins
appear to be relatively non-toxic, and protect against fungal contamination in cell culture. 相似文献
934.
Ron Milo 《Photosynthesis research》2009,101(1):59-67
The sun’s spectrum harvested through photosynthesis is the primary source of energy for life on earth. Plants, green algae, and cyanobacteria—the major primary producers on earth—utilize reaction centers that operate at wavelengths of 680 and 700 nm. Why were these wavelengths “chosen” in evolution? This study analyzes the efficiency of light conversion into chemical energy as a function of hypothetical reaction center absorption wavelengths given the sun’s spectrum and the overpotential cost associated with charge separation. Surprisingly, it is found here that when taking into account the empirical charge separation cost the range 680–720 nm maximizes the conversion efficiency. This suggests the possibility that the wavelengths of photosystem I and II were optimized at some point in their evolution for the maximal utilization of the sun’s spectrum. 相似文献
935.
Xuan SQ Zheng JY Wang H Gao P Zhou SB Liu K Zhu GP 《Genetics and molecular research : GMR》2011,10(4):3141-3145
Lycoris radiata is a perennial herb that has been used in traditional Chinese medicine for a long time and has two main medicinal components in its bulb, lycorine and galanthamine. However, the original microsatellite loci have not been developed for any species of Lycoris. Total genomic DNA was extracted from fresh bulbs using a modified CTAB protocol. We isolated 10 microsatellite loci from 21 L. radiata individuals of a natural population from Yellow Mountain in Anhui Province, China. The number of alleles ranged from two to nine. The observed and expected heterozygosities ranged from 0.238 to 0.952 and from 0.455 to 0.784, respectively. One locus significantly deviated from Hardy-Weinberg equilibrium and no significant linkage disequilibrium was found between pairs of loci. Cross-species amplification of these microsatellite loci was characterized in additional five species (L. sprengeri, L. anhuiensis, L. albiflora, L. longituba, and L. chinensis) of Lycoris. The results suggest that these microsatellite markers would contribute to the population genetic studies of L. radiata and other related species. 相似文献
936.
Shipeng Yang Qiwen Zhong Jie Tian Lihui Wang Mengliang Zhao Li Li Xuemei Sun 《Genes & genomics.》2018,40(10):1023-1032
In recent years, Jerusalem artichoke has received widespread attention as a novel source of sugar, biofuel, and animal feed. Currently, only few gDNA-SSRs derived from sunflower were verified in the Jerusalem artichoke; therefore, it is particularly important to develop SSR primer markers that belonged to Jerusalem artichoke resources. Using EST data to develop EST-SSR markers is simple and effective. In order to understand the general characteristics of SSR markers in Jerusalem artichoke EST sequences and accelerate the use of SSR markers in Jerusalem artichoke research. This study used 40,370 sequenced unigene fragments and MISA software to identify SSR loci. The 48 pairs of EST-SSR primers assessed for the identification of 45 varieties of Jerusalem artichoke. Cluster, genetic diversity parameters and AMOVA analysis was conducted using the genetic similarity coefficient, revealing genetic differences between 48 genetic material. A total of 1204 SSR loci were identified with 13 different types of repeats, distributed among 1020 EST sequences, of which trinucleotide repeats were the most common, accounting for 38.21% of the total SSR loci. Among the 44 repeat motifs, AG/CT, AAG/CTT, and ATC/ATG motifs had the highest frequencies, accounting for 22.45, 14.71, and 7.84% of all motifs, respectively. From these sequences, 48 pairs of EST-SSR primers were designed, and 22 primer pairs for loci with high polymorphism were selected to analyze the genetic diversity of 45 Jerusalem artichoke germplasm sources. The results indicated that the variation range of the effective number of alleles for 22 primers ranged between 1.7502 and 4.5660. The Shannon’s information index ranged between 0.6200 and 1.6423. The variation range of PIC ranged between 0.3121 and 0.6662 with an average of 0.5184. Cluster analysis was conducted using the genetic similarity coefficient, revealing significant genetic differences between Asian and European genetic material. Cluster analysis revealed a relationship between the genotypes and geographic origins of the Jerusalem artichoke. The results of AMOVA as well as the genetic identity and genetic distance in the Jerusalem artichoke population showed that there presented certain genetic heterogeneity in Jerusalem artichoke genetic structure of 45 samples from seven different geographic populations. The Jerusalem artichoke EST-SSR marker system established in this study provides an effective molecular marker system for future research focused on Jerusalem artichoke genetic diversity and the breeding of new varieties. 相似文献
937.
938.
939.
Cong-Ping Tan Fang-Qing Zhao Zhong-Liang Su Cheng-Wei Liang Song Qin 《Journal of applied phycology》2007,19(4):347-355
A carotenoid gene (crtR-B) from the green alga Haematococcus pluvialis, encoding β-carotene hydroxylase that was able to catalyze the conversion of β-carotene to zeaxanthin and canthaxanthin to
astaxanthin, was cloned into Chlamydomonas reinhardtii chloroplast expression vector p64D to yield plasmid p64DcrtR-B. The vector p64DcrtR-B was transferred to the chloroplast
genome of C. reinhardtii using micro-particle bombardment. PCR and Southern blot analyses indicated that crtR-B was integrated into the chloroplast genome of the transformants. RT-PCR assays showed that the H. pluvialis
crt R-B gene was expressed in C. reinhardtii transformants. The transformants rapidly synthesized carotenoids in larger quantities than the wild-type upon being transferred
from moderate to high-intensity white light. This research provides a foundation for further study to elucidate the possible
mechanism of photo-protection by xanthophylls and other carotenoids in high light conditions or through exposure to UV radiation. 相似文献
940.
Haoyong Wang Shangzhi Cao William Tianshuo Wang Kaven Tianyv Wang Xianhui Jia 《Journal of industrial microbiology & biotechnology》2016,43(6):861-871
Very high gravity (VHG) fermentation is the mainstream technology in ethanol industry, which requires the strains be resistant to multiple stresses such as high glucose concentration, high ethanol concentration, high temperature and harsh acidic conditions. To our knowledge, it was not reported previously that any ethanol-producing microbe showed a high performance in VHG fermentations without amino acid and vitamin. Here we demonstrate the engineering of a xylose utilizing recombinant Zymomonas mobilis for VHG ethanol fermentations. The recombinant strain can produce ethanol up to 136 g/L without amino acid and vitamin with a theoretical yield of 90 %, which is significantly superior to that produced by all the reported ethanol-producing strains. The intracellular fatty acids of the bacterial were about 16 % of the bacterial dry biomass, with the ratio of ethanol:fatty acids was about 273:1 (g/g). The recombinant strain was achieved by a multivariate-modular strategy tackles with the multiple stresses which are closely linked to the ethanol productivity of Z. mobilis. The over-expression of metB/yfdZ operon enabled the growth of the recombinant Z. mobilis in a chemically defined medium without amino acid and vitamin; and the fatty acids overproduction significantly increased ethanol tolerance and ethanol production. The coupled production of ethanol with fatty acids of the Z. mobilis without amino acid and vitamin under VHG fermentation conditions may permit a significant reduction of the production cost of ethanol and microbial fatty acids. 相似文献