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31.
Methylglyoxal‐induced apoptosis is dependent on the suppression of c‐FLIPL expression via down‐regulation of p65 in endothelial cells 下载免费PDF全文
32.
Improvement of canine somatic cell nuclear transfer procedure 总被引:4,自引:0,他引:4
Jang G Oh HJ Kim MK Fibrianto YH Hossein MS Kim HJ Kim JJ Hong SG Park JE Kang SK Lee BC 《Theriogenology》2008,69(2):146-154
The purpose of the present study on canine somatic cell nuclear transfer (SCNT) was to evaluate the effects of fusion strength, type of activation, culture media and site of transfer on developmental potential of SCNT embryos. We also examined the potential of enucleated bovine oocytes to serve as cytoplast recipients of canine somatic cells. Firstly, we evaluated the morphological characteristics of in vivo-matured canine oocytes collected by retrograde flushing of the oviducts 72 h after ovulation. Secondly, the effectiveness of three electrical strengths (1.8, 2.3 and 3.3 kV/cm), used twice for 20 micros, on fusion of canine cytoplasts with somatic cells were compared. Then, we compared: (1) chemical versus electrical activation (a) after parthenogenetic activation or (b) after reconstruction of canine oocytes with somatic cells; (2) culture of resulting intergeneric (IG) embryos in either (a) mSOF or (b) TCM-199. The exposure time to 6-DMAP was standardized by using bovine oocytes reconstructed with canine somatic cells. Bovine oocytes were used for SCNT after a 22 h in vitro maturation interval. The fusion rate was significantly higher in the 3.3 kV/cm group than in the 1.8 and 2.3 kV/cm treatment groups. After parthenogenesis or SCNT with chemical activation, 3.4 and 5.8%, respectively, of the embryos developed to the morula stage, as compared to none of the embryos produced using electrical activation. Later developmental stages (8-16 cells) were transferred to the uterine horn of eight recipients, but no pregnancy was detected. However, IG cloned embryos (bovine cytoplast/canine somatic cell) were capable of in vitro blastocyst development. In vitro developmental competence of IG cloned embryos was improved after exposure to 6-DMAP for 4 h as compared to 0, 2 or 6h exposure, although the increase was not significantly different among culture media. In summary, for production of canine SCNT embryos, we recommend fusion at 3.3 kV/cm, chemical activation, culture in mSOF medium and transfer of presumptive zygotes to the oviduct of recipient animals. The feasibility of IG production of cloned canine embryos using bovine cytoplasts as recipient of canine somatic cells was demonstrated. 相似文献
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Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive,
short rod-type bacteria, and able to grow anaerobically with CO2 production. The isolates grew well on MRS broth at 30–37°C and a pH of 6.5–8.0. The optimum temperature and pH for growth
are 37°C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose,
sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the
two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular
ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1%
arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0–6%. These results show for the first
time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity. 相似文献
38.
Eunyoung Jeon Soojin Lee Donghyun Kim Hyunsik Yoon Minkyu Oh Chulhwan Park Jinwon Lee 《Enzyme and microbial technology》2009,45(1):42-47
The main goal of this research was to achieve a more efficient production of 1,2-propanediol (1,2-PD) using mutated Saccharomyces cerevisiae. 1,2-PD cannot be produced by wild type S. cerevisiae. To develop a S. cerevisiae mutant that could produce 1,2-PD, the mgs gene of E. coli-K12 MG1655 and the dhaD gene of Citrobacter freundii were inserted into yeast expression vectors such as pESC-URA and pESC-TRP and transformed into the wild type of S. cerevisiae. As a result, the batch fermentation of S. cerevisiae YPH500, harboring an mgs gene inserted pJES27 vector, resulted in a yield of 0.17 g/L. On the other hand, the methylglyoxal synthase of the recombinant S. cerevisiae YPH500, harboring a dhaD gene inserted pJES29 vector, was inactive and produced no detectable amount of 1,2-PD. Therefore, in order to achieve a maximum yield of 1,2-PD, we selected the pESC-TRP vector that is able to co-express the dhaD gene with the pJES27 vector. By inserting the dhaD gene into the pESC-TRP vector, the pJES30 vector was constructed. The maximal yield of 1,2-PD achieved in a 1% galactose batch fermentation by pJES27 and pJES30 harboring S. cerevisiae was 0.45 g/L. 相似文献
39.
A new species, Allium pseudosenescens, belonging to sect. Rhizirideum (Alliaceae), is described from northeastern China. It is easily distinguished from A. senescens by the slender pedicels, pale pink perianths, narrower tepals and ovaries, yellowish anthers, and sometimes toothed subulate
filaments. Also, A. senescens var. minus in sect. Rhizirideum is raised to the rank of species, as A. minus. This Korean endemic taxon is shown to be a biologically distinct species based on morphological and cytological characters.
Taxonomic keys for the species of Allium sect. Rhizirideum in northeastern China and Korea are provided. 相似文献
40.
Oh HJ Lee JS Song DK Shin DH Jang BC Suh SI Park JW Suh MH Baek WK 《Biochemical and biophysical research communications》2007,360(4):840-845
Although D-glucosamine has been reported as an inhibitor of tumor growth both in vivo and in vitro, the mechanism for the anticancer effect of D-glucosamine is still unclear. Since there are several reports suggesting D-glucosamine inhibits protein synthesis, we examined whether D-glucosamine affects p70S6K activity, an important signaling molecule involved in protein translation. In the present study, we found D-glucosamine inhibited the activity of p70S6K and the proliferation of DU145 prostate cancer cells and MDA-MB-231 breast cancer cells. D-glucosamine decreased phosphorylation of p70S6K, and its downstream substrates RPS6, and eIF-4B, but not mTOR and 4EBP1 in DU145 cells, suggesting that D-glucosamine induced inhibition of p70S6K is not through the inhibition of mTOR. In addition, D-glucosamine enhanced the growth inhibitory effects of rapamycin, a specific inhibitor of mTOR. These findings suggest that D-glucosamine can inhibit growth of cancer cells through dephosphorylation of p70S6K. 相似文献