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61.
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
62.
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
63.
Gustavo Souto de Sá e Souza Fábio Barbosa Rodrigues Adriano O. Andrade Marcus Fraga Vieira 《Computer methods in biomechanics and biomedical engineering》2017,20(8):901-904
Gait speed is an essential parameter of gait analysis. Our study proposed a simple and accurate method to extract a mean gait speed during walking on a treadmill using only kinematic data from markers placed on the heels of the participants’ feet. This method provided an attractive, simple method that remains resistant to errors in treadmill calibration. In addition, this method required only two markers, since heel markers are essential to gait analysis, and the proposed method is robust enough to differentiate among various gait speeds (mean error <1%). 相似文献
64.
Oliveira FA Pfleger V Lang K Heukelbach J Miralles I Fraga F Sousa AQ Stoffler-Meilicke M Ignatius R Kerr LF Feldmeier H 《Memórias do Instituto Oswaldo Cruz》2007,102(6):751-756
Population-based data on sexually transmitted infections (STI), bacterial vaginosis (BV), and candidiasis reflect the epidemiological situation more accurately than studies performed in specific populations, but such data are scarce. To determine the prevalence of STI, BV, and candidiasis among women of reproductive age from a resource-poor community in Northeast Brazil, a population-based cross sectional study was undertaken. All women from seven hamlets and the centre of Pacoti municipality in the state of Ceará, aged 12 to 49 years, were invited to participate. The women were asked about socio-demographic characteristics and genital symptoms, and thereafter examined gynaecologically. Laboratory testing included polymerase chain reaction (PCR) for human papillomavirus (HPV), ligase chain reaction (LCR) for Chlamydia trachomatis and Neisseria gonorrhoeae, ELISA for human immunodeficiency virus (HIV), venereal disease research laboratory (VDRL) and fluorescent treponema antibody absorption test (FTA-ABS) for syphilis, and analysis of wet mounts, gram stains and Pap smears for trichomoniasis, candidiasis, and BV. Only women who had initiated sexual life were included in the analysis (n = 592). The prevalences of STI were: HPV 11.7% (95% confidence interval: 9.3-14.7), chlamydia 4.5% (3.0-6.6), trichomoniasis 4.1% (2.7-6.1), gonorrhoea 1.2% (0.5-2.6), syphilis 0.2% (0.0-1.1), and HIV 0%. The prevalence of BV and candidiasis was 20% (16.9-23.6) and 12.5% (10.0-15.5), respectively. The most common gynaecological complaint was lower abdominal pain. STI are common in women in rural Brazil and represent an important health threat in view of the HIV pandemic. 相似文献
65.
Duarte CD Tributino JL Lacerda DI Martins MV Alexandre-Moreira MS Dutra F Bechara EJ De-Paula FS Goulart MO Ferreira J Calixto JB Nunes MP Bertho AL Miranda AL Barreiro EJ Fraga CA 《Bioorganic & medicinal chemistry》2007,15(6):2421-2433
We describe herein the discovery of LASSBio-881 (3c) as a novel in vivo antinociceptive, anti-inflammatory, and in vitro antiproliferative and antioxidant compound, with a cannabinoid ligand profile. We observed that LASSBio-881 (3c) was able to bind to CB1 receptors (71% at 100microM) and also to inhibit T-cell proliferation (66% at 10microM) probably by binding to CB2 receptors, in a non-proapoptotic manner, different from anandamide (1). It was also demonstrated that LASSBio-881 (3c) had an important antioxidant profile toward free radicals (DPPH and hydroxyl), probably due to its particular redox behavior, which reflects the presence of both nitro and 3,5-di-tert-butyl-4-hydroxyphenyl sub-units, as demonstrated by cyclic voltammetry studies. In addition, we showed that these structural sub-units are essential for the observed pharmacological activity. 相似文献
66.
Gregorio C Eduardo S Rodrigues LC Regueira MA Fraga R Riveiros R Maestro M Mouriño A 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):227-230
Hapten derivatives of 25-hydroxyvitamin D(3) and 1alpha,25-dihydroxyvitamin D(3) were synthesized using the Wittig-Horner approach. Both haptens bearing a carboxylic group at the side chain that can be linked to a protein for raising antibodies of potential utility for the determination of 25-hydroxyvitamin D(3), 1alpha,25-dihydroxyvitamin D(3) and 1alpha-hydroxylated vitamin D(3) analogues. 相似文献
67.
López-Sánchez LM Collado JA Corrales FJ López-Cillero P Montero JL Fraga E Serrano J De La Mata M Muntané J Rodríguez-Ariza A 《Free radical research》2007,41(1):50-61
Nitric oxide (NO) participates in the cell death induced by d-Galactosamine (d-GalN) in hepatocytes, and NO-derived reactive oxygen intermediates are critical contributors to protein modification and hepatocellular injury. It is anticipated that S-nitrosation of proteins will participate in the mechanisms leading to cell death in d-GalN-treated human hepatocytes. In the present study, d-GalN-induced cell death was related to augmented levels of NO production and S-nitrosothiol (SNO) content. The biotin switch assay confirmed that d-GalN increased the levels of S-nitrosated proteins in human hepatocytes. S-nitrosocysteine (CSNO) enhanced protein S-nitrosation and altered cell death parameters that were related to S-nitrosation of the executioner caspase-3. Fifteen S-nitrosated proteins participating in metabolism, antioxidative defense and cellular homeostasis were identified in human hepatocytes treated with CSNO. Among them, seven were also identified in d-GalN-treated hepatocytes. The results here reported underline the importance of the alteration of SNO homeostasis during d-GalN-induced cell death in human hepatocytes. 相似文献
68.
González R Collado JA Nell S Briceño J Tamayo MJ Fraga E Bernardos A López-Cillero P Pascussi JM Rufián S Vilarem MJ De la Mata M Brigelius-Flohe R Maurel P Muntané J 《Free radical biology & medicine》2007,43(10):1439-1452
Vitamin E (alpha-tocopherol) has demonstrated antioxidant activity and gene-regulatory properties. d-Galactosamine (D-GalN)-induced cell death is mediated by nitric oxide in hepatocytes, and it is associated with hepatic steatosis. The beneficial properties of alpha-tocopherol and their relation to oxidative stress and gene regulation were assessed in D-GalN-induced cell death. Hepatocytes were isolated from human liver resections by a collagenase perfusion technique. alpha-Tocopherol (50 microM) was administered at the advanced stages (10 h) of D-GalN-induced cell death in cultured hepatocytes. Cell death, oxidative stress, alpha-tocopherol metabolism, and NF-kappaB-, pregnane X receptor (PXR)-, and peroxisome proliferator-activated receptor (PPAR-alpha)-associated gene regulation were estimated in the hepatocytes. D-GalN increased cell death and alpha-tocopherol metabolism. alpha-Tocopherol exerted a moderate beneficial effect against apoptosis and necrosis induced by D-GalN. Induction (rifampicin) or inhibition (ketoconazole) of alpha-tocopherol metabolism and overexpression of PXR showed that the increase in PXR-related CYP3A4 expression caused by alpha-tocopherol enhanced cell death in hepatocytes. Nevertheless, the reduction in NF-kappaB activation and inducible nitric oxide synthase expression and the enhancement of PPAR-alpha and carnitine palmitoyl transferase gene expression by alpha-tocopherol may be relevant for cell survival. In conclusion, the cytoprotective properties of alpha-tocopherol are mostly related to gene regulation rather than to antioxidant activity in toxin-induced cell death in hepatocytes. 相似文献
69.