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391.
Pohlenz C Buentello A Criscitiello MF Mwangi W Smith R Gatlin DM 《Fish & shellfish immunology》2012,33(3):543-551
Channel catfish was used to investigate the enhancement of vaccine efficacy following dietary supplementation with arginine (ARG, 4% of diet), glutamine (GLN, 2% of diet), or a combination of both. After vaccination against Edwardsiella ictaluri, humoral and cellular immune responses, along with lymphoid organ responses were evaluated. E.?ictaluri-specific antibody titers in plasma were higher (P?0.05) in fish fed the supplemented diets compared to those fed the basal diet as early as 7?d post-vaccination (dpv). B-cell proportion in head-kidney was higher (P?0.05) at 14?dpv in vaccinated fish fed the GLN diet. The responsiveness of spleen and head-kidney lymphocytes against E.?ictaluri was enhanced (P?0.05) by dietary supplementation of ARG or GLN at 14?dpv. Additionally, at 7?dpv, vaccinated fish fed the GLN diet had higher (P?0.05) head kidney weights relative to the other dietary treatments, and vaccinated fish fed ARG-supplemented diets had higher (P?0.05) protein content in this tissue. Results from this study suggest that dietary supplementation of ARG and GLN may improve specific cellular and humoral mechanisms, enhancing the acquired immunity in vaccinated channel catfish. 相似文献
392.
Luis Merino‐Martín David D. Breshears Mariano Moreno‐de las Heras Juan Camilo Villegas Silvia Pérez‐Domingo Tíscar Espigares Jose M. Nicolau 《Restoration Ecology》2012,20(3):360-368
Vegetation, soil, and hydrology in drylands often collectively exhibit strong ecohydrological interrelationships in which vegetation both influences and is influenced by runoff, particularly on sites with more gradual slopes. These two‐way relationships have important implications for ecological restoration of disturbed sites, such as those being reclaimed following mining, yet studies from both ecological and hydrological perspectives specifically evaluating how the strength of ecohydrological interrelationships varies for a range of natural and restored conditions are still missing. We assessed two‐way relationships between vegetation and soil hydrological properties by evaluating patterns of both plant community structure and soil hydrological characteristics related to runoff for natural sites and restored sites following mining. At the plot scale, we identified eight ecohydrological units based on interrelationships between vegetation communities and hydrological properties associated with runoff along a progression from source to sink patch types. Similarly, at the hillslope scale, which included patches of different types, we found a correspondence between the proportions of source and sink patches and both vegetation community and hydrological properties. The relative strength of ecohydrological interrelationships in hillslope mosaics decreased with decreasing disturbance except for rilled hillslopes, likely because parts of the hillslope become isolated from the others. Our results highlight, in general, how ecohydrological interrelationships are related with degree of disturbance, and in particular, how rilling alters ecohydrological interrelationships, thereby precluding effective restoration. 相似文献
393.
Miguel Ángel Pérez‐Farrera Andrew P. Vovides Rubén Martínez‐Camilo Nayely Martínez‐Meléndez Héctor Gómez‐Domínguez Sonia Galicia‐Castellanos 《Nordic Journal of Botany》2012,30(5):565-570
Zamia grijalvensis, a new cycad species from Chiapas, México, is described and illustrated. This species is similar to Z. lacandona with respect to leaves, but differs in habit, morphology and colour of the female and male cones. The female cone of Z. grijalvensis is reddish brown to orange brown, whereas that of Z. lacandona is dark brown with lighter beige tomentum. The male cone of Z. grijalvensis is erect, whereas that of Z. lacandona is decumbent. The new species may be of natural hybrid origin and is discussed in the light of other findings among cycads. Preliminary diploid chromosome counts for Z. grijalvensis 2n = 19, 20 and karyotypes appear variable, as previously found in its congeners with wide distribution, such as Z. paucijuga and Z. prasina, both of which are characterised by high diploid numbers with a high number of telocentric and few metacentric chromosomes. These changes in chromosome number are probably the result of stressful environmental factors. 相似文献
394.
Camilo Mora-Navarro Janet Méndez-Vega Jean Caraballo-León Myung-ryul Lee Sean Palecek Madeline Torres-Lugo Patricia Ortiz-Bermúdez 《PloS one》2016,11(3)
The widespread distribution of fungal infections, with their high morbidity and mortality rate, is a global public health problem. The increase in the population of immunocompromised patients combined with the selectivity of currents treatments and the emergence of drug-resistant fungal strains are among the most imperative reasons to develop novel antifungal formulations. Antimicrobial β-peptides are peptidomimetics of natural antimicrobial peptides (AMPs), which have been proposed as developmental platforms to enhance the AMPs selectivity and biostability. Their tunability allows the design of sequences with remarkable activity against a wide spectrum of microorganisms such as the human pathogenic Candida spp., both in planktonic and biofilm morphology. However, the β-peptide’s effect on surrounding host cells remains greatly understudied. Assessments have mainly relied on the extent of hemolysis that a candidate peptide is able to cause. This work investigated the in vitro cytotoxicity of various β-peptides in the Caco-2 and HepG2 mammalian cell lines. Results indicated that the cytotoxic effect of the β-peptides was influenced by cell type and was also correlated to structural features of the peptide such as hydrophobicity. We found that the selectivity of the most hydrophobic β-peptide was 2–3 times higher than that of the least hydrophobic one, for both cell types according to the selectivity index parameter (IC50/MIC). The IC50 of Caco-2 and HepG2 increased with hydrophobicity, which indicates the importance of testing putative therapeutics on different cell types. We report evidence of peptide-cell membrane interactions in Caco-2 and HepG2 using a widely studied β-peptide against C. albicans. 相似文献
395.
Pérez-Neri I Castro E Montes S Boll MC Barges-Coll J Soto-Hernández JL Ríos C 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,851(1-2):250-256
Citrulline and nitric oxide (NO) are synthesized by NO synthase (NOS) in a 1:1-stoichiometry. In this study, we determined by HPLC arginine and citrulline concentrations by fluorescence detection and nitrate levels by UV absorbance detection in the cerebrospinal fluid (CSF) from patients with acute hydrocephalus that underwent ventricular drainage. We found increased citrulline concentration (50.6+/-17.2 versus 20.9+/-2.0 microM) and decreased arginine/citrulline molar ratio (0.42+/-0.11 versus 1.12+/-0.16) in hydrocephalus patients, while arginine and nitrate concentrations and citrulline/nitrate molar ratio remained with little change. Citrulline has been determined as a marker of NOS activity in some studies, but it remains to be determined the extent at which this statement holds true, since other biochemical pathways also regulate the concentration of this amino acid. Our results suggest that citrulline is primarily synthesized from NOS in acute hydrocephalus. The evaluation of sample deproteinization by addition of methanol for the analysis of amino acids in CSF is also reported. 相似文献
396.
Mora C Metzger R Rollo A Myers RA 《Proceedings. Biological sciences / The Royal Society》2007,274(1613):1023-1028
Populations of many species are dramatically declining worldwide, but the causal mechanism remains debated among different human-related threats. Coping with this uncertainty is critical to several issues about the conservation and future of biodiversity, but remains challenging due to difficulties associated with the experimental manipulation and/or isolation of the effects of such threats under field conditions. Using controlled microcosm populations, we quantified the individual and combined effects of environmental warming, overexploitation and habitat fragmentation on population persistence. Individually, each of these threats produced similar and significant population declines, which were accelerated to different degrees depending upon particular interactions. The interaction between habitat fragmentation and harvesting generated an additive decline in population size. However, both of these threats reduced population resistance causing synergistic declines in populations also facing environmental warming. Declines in population size were up to 50 times faster when all threats acted together. These results indicate that species may be facing risks of extinction higher than those anticipated from single threat analyses and suggest that all threats should be mitigated simultaneously, if current biodiversity declines are to be reversed. 相似文献
397.
398.
Camilo Ayra-Pardo Maria E. Ochagavia Ben Raymond Asim Gulzar Lianet Rodriguez-Cabrera Claudia Rodriguez de la Noval Ivis Moran Bertot Ryohei Terauchi Kentaro Yoshida Hideo Matsumura Pilar Tellez Rodriguez Daily Hernandez Hemandez Orlando Borras-Hidalgo Denis J. Wright 《Insect Science》2019,26(3):479-498
399.
Javier Gómez-Ambrosi Victoria Catalán Amaia Rodríguez Beatriz Ramírez Camilo Silva María J. Gil Javier Salvador Gema Frühbeck 《The Journal of nutritional biochemistry》2010,21(8):774-780
Adipose tissue is highly vascularized implying that angiogenesis takes place in its expansion. The aim of this study was to compare the concentrations of members of the vascular endothelial growth factor (VEGF) family in obesity. Serum concentrations of VEGFs were analyzed in 15 lean (BMI 20.3±2.5 kg/m2) and 24 obese (BMI 47.6±5.9 kg/m2) volunteers. Obese patients showed significantly increased circulating VEGF-A (150±104 vs. 296±160 pg/ml; P<.05), VEGF-B (2788±1038 vs. 4609±2202 arbitrary units; P<.05) and VEGF-C (13 453±5750 vs. 17 635±5117 pg/ml; P<.05) concentrations. Interestingly, levels of VEGF-D were reduced in obese individuals (538±301 vs. 270±122 pg/ml; P<.01). In addition, VEGF-A significantly decreased after weight loss following Roux-en-Y gastric bypass (BMI from 46.0±8.0 to 28.9±4.2 kg/m2 P<.0001 vs. initial) from 345±229 to 290±216 pg/ml (P<.01). Moreover, in order to corroborate the human findings VEGF-A levels were analyzed during the expansion of adipose tissue in two dynamic models of murine obesity. Serum VEGF-A was significantly increased after 12 weeks on a high-fat diet (43.3±9.0 vs. 29.7±9.1 pg/ml; P<.01) or in ob/ob mice (52.2±18.0 vs. 29.2±7.7 pg/ml; P<.01) and was normalized after leptin replacement in the latter (32.4±14.0 pg/ml; P<.01 vs. untreated ob/ob). Our data indicates the involvement of these factors in the expansion of adipose tissue that takes place in obesity in relation to the need for increased vascularization, suggesting that manipulation of the VEGF system may represent a potential target for the pharmacological treatment of obesity. 相似文献
400.
Camilo L. Medina Maria Cristina Sanches Maria Luiza S. Tucci Carlos A. F. Sousa Geraldo Rog��rio F. Cuzzuol Carlos A. Joly 《Annals of botany》2009,104(4):671-680