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991.
Sei Kwang Hahn Yong Keun Chang Beom Soo Kim Kyung Mi Lee Ho Nam Chang 《Biotechnology Techniques》1993,7(3):209-212
Summary To take advantage of both differential digestion by hypochlorite and solvent extraction, we used dispersions of sodium hypochlorite
solution and chloroform in the recovery of microbial PHB. The treatment with hypochlorite alone caused such severe degradation
and the molecular weight decreased drastically with increasing hypochlorite concentration. However, using the dispersion,
the degradation of PHB was markedly diminished owing to theshielding effect of chloroform. In this case, we could obtain PHB of above 97% purity with a number average molecular weight of 1,000,000
comparable to the original molecular weight of 1,200,000. 相似文献
992.
Stable genetic transformation of Arabidopsis thaliana by Agrobacterium inoculation in planta 总被引:9,自引:0,他引:9
Seok So Chang Soon Ki Park Byung Chul Kim Bong Joong Kang Dal Ung Kim Hong Gil Nam 《The Plant journal : for cell and molecular biology》1994,5(4):551-558
Stable genetic transformation of Arabidopsis thaliana was achieved by simple in planta inoculation of Agrobacterium tumefaciens strain LBA4404 harboring a binary vector pBl121. The transformation procedure, which we call in planta transformation, involves severing of apical shoots at their bases, inoculation with Agrobacterium at the severed sites, and in planta generation of shoots from the severed sites. On average, 5.5% of the newly formed shoots produced transformed progenies. These progenies (T2 generation) contained T-DNA in the genome as examined by assaying the T-DNA encoded β-glucuronidase and kanamycin resistance and by genomic Southern blot analysis, the copy number of the T-DNAs in the Arabidopsis genome being single (33%) or multiple. The genetic behavior of the transformants examined at the T3 and T4 generations or with the F2 progenies of the outcrosses between transformants and wild-type plants showed that most of the inserted T-DNA are inherited in a Mendelian fashion. This procedure provides a new approach for simple and efficient transformation of A. thaliana, obviating the need for plant regeneration from tissue explants in vitro. 相似文献
993.
The formation of new vacuoles around injected algae was studied in amoebae at intervals after enucleation. Algae initially lay free for 3 h within the amoeba cytoplasm, after which they gradually became individually enclosed within single-vacuole membranes. During the initial stage of vacuole formation (4–24 h), discontinuous pieces of non-trilaminar membrane-like structures appeared around the algae, which were not associated with any preexisting membranes. Over 85 and 50% of injected algae became enclosed in vacuoles in amoebae that had been without nuclei between 0–16 and 18–36 h, respectively. Thus, it appeared that vacuole-forming activity was not under the immediate control of cell nuclei. This mode of vacuole formation suggested that the initial vacuole membranes might arise de novo. 相似文献
994.
995.
Electrochemical treatment (ECT) of cancer utilizes direct current to produce chemical changes in tumors. ECT has been suggested as an effective alternative local cancer therapy. However, a methodology is not established, and mechanisms are not well studied. In vivo studies were conducted to evaluate the effectiveness of ECT on animal tumor models. Radiation-induced fibrosarcomas were implanted subcutaneously in 157 female C3H/HeJ mice. Larger rat fibrosarcomas were implanted on 34 female Fisher 344 rats. When the spheroidal tumors reached 10 mm in the mice, two to five platinum electrodes were inserted into the tumors at various spacings and orientations. Ten rats in a pilot group were treated when their ellipsoidal tumors were about 25 mm long; electrode insertion was similar to the later part of the mouse study, i.e., two at the base and two at the center. A second group of 24 rats was treated with six or seven electrodes when their tumors were about 20 mm long; all electrodes were inserted at the tumor base. Of the 24 rats, 12 of these were treated once, 10 were treated twice, and 2 were treated thrice. All treated tumors showed necrosis and regression for both mice and rats; however, later tumor recurrence reduced long-term survival. When multiple treatments were implemented, the best 3 month mouse tumor cure rate was 59.3%, and the best 6 month rat tumor cure rate was 75.0%. These preliminary results indicate that ECT is effective on the radiation-induced fibrosarcoma (RIF-1) mouse tumor and rat fibrosarcoma. The effectiveness is dependent on electrode placement and dosage. Bioelectromagnetics 18:14–24, 1997. © 1997 Wiley-Liss, Inc. 相似文献
996.
997.
Austin M. Reilly Shijun Yan Menghao Huang Surabhi D. Abhyankar Jason M. Conley Robert N. Bone Natalie D. Stull Daniel J. Horan Hyun C. Roh Alexander G. Robling Aaron C. Ericsson Xiaocheng C. Dong Carmella Evans-Molina Hongxia Ren 《The Journal of biological chemistry》2022,298(1)
Insulin resistance impairs postprandial glucose uptake through glucose transporter type 4 (GLUT4) and is the primary defect preceding type 2 diabetes. We previously generated an insulin-resistant mouse model with human GLUT4 promoter-driven insulin receptor knockout (GIRKO) in the muscle, adipose, and neuronal subpopulations. However, the rate of diabetes in GIRKO mice remained low prior to 6 months of age on normal chow diet (NCD), suggesting that additional factors/mechanisms are responsible for adverse metabolic effects driving the ultimate progression of overt diabetes. In this study, we characterized the metabolic phenotypes of the adult GIRKO mice acutely switched to high-fat diet (HFD) feeding in order to identify additional metabolic challenges required for disease progression. Distinct from other diet-induced obesity (DIO) and genetic models (e.g., db/db mice), GIRKO mice remained leaner on HFD feeding, but developed other cardinal features of insulin resistance syndrome. GIRKO mice rapidly developed hyperglycemia despite compensatory increases in β-cell mass and hyperinsulinemia. Furthermore, GIRKO mice also had impaired oral glucose tolerance and a limited glucose-lowering benefit from exendin-4, suggesting that the blunted incretin effect contributed to hyperglycemia. Secondly, GIRKO mice manifested severe dyslipidemia while on HFD due to elevated hepatic lipid secretion, serum triglyceride concentration, and lipid droplet accumulation in hepatocytes. Thirdly, GIRKO mice on HFD had increased inflammatory cues in the gut, which were associated with the HFD-induced microbiome alterations and increased serum lipopolysaccharide (LPS). In conclusion, our studies identified important gene/diet interactions contributing to diabetes progression, which might be leveraged to develop more efficacious therapies. 相似文献
998.
Min Chul Kim Woo Sik Chung Dae-Jin Yun Moo Je Cho 《植物生理学报》2009,(1):13-21
999.
1000.