全文获取类型
收费全文 | 359篇 |
免费 | 19篇 |
专业分类
378篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 13篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 16篇 |
2011年 | 18篇 |
2010年 | 16篇 |
2009年 | 19篇 |
2008年 | 19篇 |
2007年 | 29篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有378条查询结果,搜索用时 10 毫秒
91.
92.
Impact of two fluorescent pseudomonads and an arbuscular mycorrhizal fungus on tomato plant growth,root architecture and P acquisition 总被引:5,自引:0,他引:5
The ability of fluorescent pseudomonads and arbuscular mycorrhizal fungi (AMF) to promote plant growth is well documented but knowledge of the impact of pseudomonad-mycorrhiza mixed inocula on root architecture is scanty. In the present work, growth and root architecture of tomato plants (Lycopersicon esculentum Mill. cv. Guadalete), inoculated or not with Pseudomonas fluorescens 92rk and P190r and/or the AMF Glomus mosseae BEG12, were evaluated by measuring shoot and root fresh weight and by analysing morphometric parameters of the root system. The influence of the microorganisms on phosphorus (P) acquisition was assayed as total P accumulated in leaves of plants inoculated or not with the three microorganisms. The two bacterial strains and the AMF, alone or in combination, promoted plant growth. P. fluorescens 92rk and G. mosseae BEG12 when co-inoculated had a synergistic effect on root fresh weight. Moreover, co-inoculation of the three microorganisms synergistically increased plant growth compared with singly inoculated plants. Both the fluorescent pseudomonads and the myco-symbiont, depending on the inoculum combination, strongly affected root architecture. P. fluorescens 92rk increased mycorrhizal colonization, suggesting that this strain is a mycorrhization helper bacterium. Finally, the bacterial strains and the AMF, alone or in combination, improved plant mineral nutrition by increasing leaf P content. These results support the potential use of fluorescent pseudomonads and AMF as mixed inoculants for tomato and suggest that improved tomato growth could be related to the increase in P acquisition. 相似文献
93.
Blancou P Mallone R Martinuzzi E Sévère S Pogu S Novelli G Bruno G Charbonnel B Dolz M Chaillous L van Endert P Bach JM 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(11):7458-7466
Type 1 diabetes (T1D) results from the autoimmune destruction of pancreatic beta cells. CD8(+) T cells have recently been assigned a major role in beta cell injury. Consequently, the identification of autoreactive CD8(+) T cells in humans remains essential for development of therapeutic strategies and of assays to identify aggressive cells. However, this identification is laborious and limited by quantities of human blood samples available. We propose a rapid and reliable method to identify autoantigen-derived epitopes recognized by human CD8(+) T lymphocytes in T1D patients. Human histocompatibility leukocyte Ags-A*0201 (HLA-A*0201) transgenic mice were immunized with plasmids encoding the T1D-associated autoantigens: 65 kDa glutamic acid decarboxylase (GAD) or insulinoma-associated protein 2 (IA-2). Candidate epitopes for T1D were selected from peptide libraries by testing the CD8(+) reactivity of vaccinated mice. All of the nine-candidate epitopes (five for GAD and four for IA-2) identified by our experimental approach were specifically recognized by CD8(+) T cells from newly diagnosed T1D patients (n = 19) but not from CD8(+) T cells of healthy controls (n = 20). Among these, GAD(114-123), GAD(536-545) and IA-2(805-813) were recognized by 53%, 25%, and 42% of T1D patients, respectively. 相似文献
94.
Alberto Sturaro Giorgio Parvoli Lucio Doretti Graziella Allegri Carlo Costa 《Biological trace element research》1994,40(1):1-8
The hair of 132 healthy subjects between 6 and 40 yr old living in the Veneto region in Italy was analyzed by means of HPLC method in order to determine the presence of zinc, copper, nickel, manganese, and lead. The collected samples were subdivided on the basis of age (6–11 and 19–40 yr), and sex and color (black, red, brown, and blond). From the data some evident differences were emphasized. In female hair the content of metals was higher than in male hair independently of color. Blond hair gave the lowest concentration values of the elements studied independently of sex. The maximum amount of the metals was found generally in black hair, followed by red and brown hair. Age seems to have a different influence, with the copper element decreasing appreciably in brown and blond female hair as the age of the subjects increased. 相似文献
95.
96.
Mérot Y Métivier R Penot G Manu D Saligaut C Gannon F Pakdel F Kah O Flouriot G 《The Journal of biological chemistry》2004,279(25):26184-26191
97.
Karmele Valencia Cristina Sainz Cristina Brtolo Gabriel de Biurrun Jackeline Agorreta Arantza Azpilikueta Marta Larrayoz Graziella Bosco Carolina Zandueta Miriam Redrado Esther Redín Francisco Exposito Diego Serrano Mirari Echepare Daniel Ajona Ignacio Melero Ruben Pio Roman Thomas Alfonso Calvo Luis M. Montuenga 《Disease models & mechanisms》2022,15(1)
98.
Michelle S. Libério Graziella A. Joanitti Ricardo B. Azevedo Eduardo M. Cilli Lanuse C. Zanotta Anna C. Nascimento Marcelo V. Sousa Osmindo R. Pires Júnior Wagner Fontes Mariana S. Castro 《Amino acids》2011,40(1):51-59
Nowadays, the emergence of resistance to the current available chemotherapeutic drugs by cancer cells makes the development of new agents imperative. The skin secretion of amphibians is a natural rich source of antimicrobial peptides (AMP), and researchers have shown that some of these wide spectrum molecules are also toxic to cancer cells. The aim of this study was to verify a putative anticancer activity of the AMP pentadactylin isolated for the first time from the skin secretion of the frog Leptodactylus labyrinthicus and also to study its cytotoxic mechanism to the murine melanoma cell line B16F10. The results have shown that pentadactylin reduces the cell viability of B16F10 cells in a dose-dependent manner. It was also cytotoxic to normal human fibroblast cells; nevertheless, pentadactylin was more potent in the first case. The studies of action mechanism revealed that pentadactylin causes cell morphology alterations (e.g., round shape and shrinkage morphology), membrane disruption, DNA fragmentation, cell cycle arrest at the S phase, and alteration of mitochondrial membrane potential, suggesting that B16F10 cells die by apoptosis. The exact mechanism that causes reduction of cell viability and cytotoxicity after treatment with pentadactylin is still unknown. In conclusion, as cancer cells become resilient to death, it is worthwhile the discovery of new drugs such as pentadactylin that induces apoptosis. 相似文献
99.
Ferri N Radice T Antonino M Beccalli EM Tinelli S Zunino F Corsini A Pratesi G Ragg EM Gelmi ML Contini A 《Bioorganic & medicinal chemistry》2011,19(18):5291-5299
Bis-2,3-heteroarylmaleimides and polyheterocondensed imides joined through nitrogen atoms of the N,N'-bis(ethyl)-1,3-propanediamine linker were prepared from substituted maleic anhydrides and symmetrical diamines in good to satisfactory yields and short reaction times using microwave heating. The novel molecules were shown to inhibit proliferation of human tumor cells (NCI-H460 lung carcinoma) and rat aortic smooth muscle cells (SMCs) with variable potencies. Compound 11a, the most potent one of the series, showed IC(50) values comparable to those observed for the leading molecule elinafide in both cell lines, but with a higher selectivity toward human tumor cells. Compound 11a affected G1/S phase transition of the cell cycle, showed in vitro DNA intercalating activity and in vivo antitumor activity. A thorough structural analysis of the 11a-DNA complex was also made by mean of NMR and computational techniques. 相似文献
100.
F Patti A Nicoletti C Leone S Messina E D'Amico S Lo Fermo V Paradisi E Bruno G Quattrocchi P Veroux L Di Pino L Costanzo M Zappia 《PloS one》2012,7(8):e41227