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101.
Blanca Céspedes Iván Torres Belén Luna Beatriz Pérez José M. Moreno 《Plant Ecology》2012,213(3):383-393
Soil seed banks play a major role in the post-fire regeneration of Mediterranean shrublands. They vary throughout the year
in species composition, abundance, and readiness to germinate. After fire, germination occurs mainly during the following
fall to spring. Time of germination can determine recruitment success. It is unclear what factors control post-fire germination
and its timing. We tested the effects of season and fire on the readily germinable soil seed bank of a seeder-dominated shrubland.
Plots were burned early and late in the summer season (ES, LS). Soil samples were collected before and after fire, and germinated
in a chamber simulating successively autumn, winter, and spring conditions. Samples were kept moistened at all times. Fire
intensity was similar between ES and LS. Several species of Cistus and herbs, mostly annuals, were dominant. Most germination occurred during the simulated-autumn period, with little subsequent
germination during the following two periods. Germination speed (T
50) during simulated-autumn was similar for shrubs and herbs, and independent of season or fire. Germination was lower for two
shrubs (Rosmarinus officinalis, Cistus salvifolius) and higher for herbaceous dicots in LS than in ES soils. Fire reduced monocots and enhanced Cistus. Germination period significantly interacted with fire and season in some groups or species, altering the simulated-autumn
germination peak. We demonstrate that the seed bank can germinate swiftly under simulated-autumn conditions. Hence, water
availability is the main controlling factor of germination. Fire season differentially affected some species or groups, and
could affect the post-fire regeneration. 相似文献
102.
A Lamana A Balsa B Rueda AM Ortiz L Nuño ME Miranda-Carus MF Gonzalez-Escribano MA Lopez-Nevot D Pascual-Salcedo J Martin I González-Álvaro 《PloS one》2012,7(8):e43661
Background
The number of copies of the HLA-DRB1 shared epitope, and the minor alleles of the STAT4 rs7574865 and the PTPN22 rs2476601 polymorphisms have all been linked with an increased risk of developing rheumatoid arthritis. In the present study, we investigated the effects of these genetic variants on disease activity and disability in patients with early arthritis.Methodology and Results
We studied 640 patients with early arthritis (76% women; median age, 52 years), recording disease-related variables every 6 months during a 2-year follow-up. HLA-DRB1 alleles were determined by PCR-SSO, while rs7574865 and rs2476601 were genotyped with the Taqman 5′ allelic discrimination assay. Multivariate analysis was performed using generalized estimating equations for repeated measures. After adjusting for confounding variables such as gender, age and ACPA, the TT genotype of rs7574865 in STAT4 was associated with increased disease activity (DAS28) as compared with the GG genotype (β coefficient [95% confidence interval] = 0.42 [0.01–0.83], p = 0.044). Conversely, the presence of the T allele of rs2476601 in PTPN22 was associated with diminished disease activity during follow-up in a dose-dependent manner (CT genotype = −0.27 [−0.56– −0.01], p = 0.042; TT genotype = −0.68 [−1.64– −0.27], p = 0.162). After adjustment for gender, age and disease activity, homozygosity for the T allele of rs7574865 in STAT4 was associated with greater disability as compared with the GG genotype.Conclusions
Our data suggest that patients with early arthritis who are homozygous for the T allele of rs7574865 in STAT4 may develop a more severe form of the disease with increased disease activity and disability. 相似文献103.
Arango-Gonzalez B Schatz A Bolz S Eslava-Schmalbach J Willmann G Zhour A Zrenner E Fischer MD Gekeler F 《PloS one》2012,7(4):e35687
Objectives
To explore the effect of ketamine-xylazine anesthesia on light-induced retinal degeneration in rats.Methods
Rats were anesthetized with ketamine and xylazine (100 and 5 mg, respectively) for 1 h, followed by a recovery phase of 2 h before exposure to 16,000 lux of environmental illumination for 2 h. Functional assessment by electroretinography (ERG) and morphological assessment by in vivo imaging (optical coherence tomography), histology (hematoxylin/eosin staining, TUNEL assay) and immunohistochemistry (GFAP and rhodopsin staining) were performed at baseline (ERG), 36 h, 7 d and 14 d post-treatment. Non-anesthetized animals treated with light damage served as controls.Results
Ketamine-xylazine pre-treatment preserved retinal function and protected against light-induced retinal degeneration. In vivo retinal imaging demonstrated a significant increase of outer nuclear layer (ONL) thickness in the non-anesthetized group at 36 h (p<0.01) and significant reduction one week (p<0.01) after light damage. In contrast, ketamine-xylazine pre-treated animals showed no significant alteration of total retinal or ONL thickness at either time point (p>0.05), indicating a stabilizing and/or protective effect with regard to phototoxicity. Histology confirmed light-induced photoreceptor cell death and Müller cells gliosis in non-anesthetized rats, especially in the superior hemiretina, while ketamine-xylazine treated rats showed reduced photoreceptor cell death (TUNEL staining: p<0.001 after 7 d), thicker ONL and longer IS/OS. Fourteen days after light damage, a reduction of standard flash induced a-wave amplitudes and a-wave slopes (p = 0.01) and significant alterations in parameters of the scotopic sensitivity function (e.g. Vmax of the Naka Rushton fit p = 0.03) were observed in non-treated vs. ketamine-xylazine treated animals.Conclusions
Our results suggest that pre-treatment with ketamine-xylazine anesthesia protects retinas against light damage, reducing photoreceptor cell death. These data support the notion that anesthesia with ketamine-xylazine provides neuroprotective effects in light-induced cell damage. 相似文献104.
105.
Arantxa Palacín Cristina Gómez-Casado Luis A. Rivas Jacobo Aguirre Leticia Tordesillas Joan Bartra Carlos Blanco Teresa Carrillo Javier Cuesta-Herranz Consolación de Frutos Genoveva García álvarez-Eire Francisco J. Fernández Pedro Gamboa Rosa Mu?oz Rosa Sánchez-Monge Sofía Sirvent María J. Torres Susana Varela-Losada Rosalía Rodríguez Victor Parro Miguel Blanca Gabriel Salcedo Araceli Díaz-Perales 《PloS one》2012,7(12)
The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens. 相似文献
106.
José A. G. Agúndez Pedro Ayuso José A. Cornejo-García Miguel Blanca María J. Torres Inmaculada Do?a María Salas Natalia Blanca-López Gabriela Canto Carmen Rondon Paloma Campo José J. Laguna Javier Fernández Carmen Martínez Elena García-Martín 《PloS one》2012,7(11)
Non-steroidal anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved in hypersensitivity drug reactions. Histamine is released in the allergic response to NSAIDs and is responsible for some of the clinical symptoms. The aim of this study is to analyze clinical association of functional polymorphisms in the genes coding for enzymes involved in histamine homeostasis with hypersensitivity response to NSAIDs. We studied a cohort of 442 unrelated Caucasian patients with hypersensitivity to NSAIDs. Patients who experienced three or more episodes with two or more different NSAIDs were included. If this requirement was not met diagnosis was established by challenge. A total of 414 healthy unrelated controls ethnically matched with patients and from the same geographic area were recruited. Analyses of the SNPs rs17740607, rs2073440, rs1801105, rs2052129, rs10156191, rs1049742 and rs1049793 in the HDC, HNMT and DAO genes were carried out by means of TaqMan assays. The detrimental DAO 16 Met allele (rs10156191), which causes decreased metabolic capacity, is overrepresented among patients with crossed-hypersensitivity to NSAIDs with an OR = 1.7 (95% CI = 1.3–2.1; Pc = 0.0003) with a gene-dose effect (P = 0.0001). The association was replicated in two populations from different geographic areas (Pc = 0.008 and Pc = 0.004, respectively).
Conclusions and implications
The DAO polymorphism rs10156191 which causes impaired metabolism of circulating histamine is associated with the clinical response in crossed-hypersensitivity to NSAIDs and could be used as a biomarker of response. 相似文献107.
108.
109.
Zamira A. Ávila-Valle Alondra Castro-Campillo Livia León-Paniagua Isaías H. Salgado-Ugalde Adolfo G. Navarro-Sigüenza Blanca E. Hernández-Baños José Ramírez-Pulido 《Mammalian Biology》2012,77(3):166-177
Several authors have discussed whether Peromyscus furvus is a monotypic species rather than a polytypic entity, that it includes more than one species. Here, we analyze these questions by means of traditional morphometrics and by genetic analyses using ND3-ND4 mtDNA genes as markers. In spite of a generalized overlap of the measurable characters among populations, our analyses show that the northernmost populations, which was assignable to P. latirostris, consistently show larger dimensions overall. The amount of genetic differentiation revealed by our molecular data, support conclusive evidence to suggest this taxon is a valid species. Our results also disclose that morphometric and molecular segregation between P. furvus and P. angustirostris is still incomplete. Finally, the two populations from the state of Oaxaca showed more morphometric affinity with those attributable to P. furvus and revealed a discrete degree of genetic differentiation. Nevertheless, their systematic position is not clear yet. 相似文献
110.