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排序方式: 共有2727条查询结果,搜索用时 15 毫秒
101.
Pettenuzzo LF Schuck PF Fontella F Wannmacher CM Wyse AT Dutra-Filho CS Netto CA Wajner M 《Pharmacology, biochemistry, and behavior》2002,73(3):623-629
Propionic acidemia is an inherited neurometabolic disorder characterized by progressive neurological deterioration with psychomotor delay/mental retardation, convulsions and coma, and whose pathophysiology is poorly unknown. In the present study, we investigated the effect of chronic administration (from the 5th to the 28th days of life) of propionic acid (PA), the major metabolite accumulating in tissues of patients affected by propionic acidemia, on the cognitive performance of adult rats in the Morris water maze task. PA doses ranged from 1.44 to 1.92 micromol/g body weight as a function of animal age. Control rats were treated with saline in the same volumes. Chronic postnatal days (5-28) PA treatment had no effect on body weight. However, it impaired spatial performance in the water maze. We also determined the effect of ascorbic acid (AA) administered, alone or combined with PA, on the same behavioral parameters in order to test whether free radicals could be responsible for the behavioral alterations observed in PA-treated animals. AA was able to prevent the behavioral alterations provoked by PA, implying that oxidative stress may be involved in these effects. Furthermore, we also investigated the total radical-trapping antioxidant potential (TRAP) in the hippocampus of the animals. We observed that TRAP was significantly reduced in the brain of propionic acidemic rats and that co-administration of AA prevented this effect. The results provide evidence that early PA treatment induces long-lasting behavioral deficits, which are possibly caused by oxygen reactive species generation, and suggest that oxidative stress may be involved in the neuropathology of propionic acidemia. 相似文献
102.
Information on the intestinal transport of L-3,4-dihydroxyphenylalanine (L-DOPA) is scarce. We present here the functional characteristics and regulation of the apical inward L-DOPA transport in two intestinal epithelial cell lines (human Caco-2 and rat IEC-6). The inward transfer of L-DOPA and L-leucine was promoted through an energy-driven system but with different sensitivity to extracellular Na(+) concentration: a minor component of L-leucine uptake (approximately 25%) was found to require extracellular Na(+) in comparison with L-DOPA transport which was Na(+)-independent. L-DOPA and L-leucine uptake was insensitive to N-(methylamino)-isobutyric acid, but competitively inhibited by 2-aminobicyclo(2,2,1)-heptane-2-carboxylic acid (BCH). L- and D-neutral amino acids, but not acidic and basic amino acids, markedly inhibited L-DOPA and [(14)C]L-leucine accumulation in both cell lines. The [(14)C]L-DOPA and [14C]L-leucine outward were markedly increased by L-leucine and BCH present in extracellular medium, but not by L-arginine. In both cell lines, L-DOPA transport was stimulated by acidic pH in comparison with [(14)C]L-leucine inward which was pH-independent. In conclusion, it is likely that system B(0) might be responsible for the Na(+)-dependent uptake of L-leucine in Caco-2 and IEC-6 cells, whereas sodium-independent uptake of L-leucine and L-DOPA may include system type 1 and type 2 L-amino acid transporter (LAT1 and LAT2), the activation of which results in trans-stimulation of substrates outward transfer. 相似文献
103.
Rijo P Gaspar-Marques C Simões MF Duarte A Del Carmen Apreda-Rojas M Cano FH Rodríguez B 《Journal of natural products》2002,65(10):1387-1390
Three new diterpenoids, a neoclerodane and two labdane derivatives, have been isolated from an acetone extract of Plectranthus ornatus. The structures of these compounds (plectrornatins A-C, 1-3, respectively) were established mainly by spectroscopic means, particularly by 1D and 2D NMR studies and, in the case of the neoclerodane 1, by an X-ray diffraction analysis. Compounds 1 and 3 showed moderate antimicrobial activity against five Candida species and selected Gram negative and Gram positive bacteria strains. 相似文献
104.
105.
Mancini MC Fiúza PM Rebelo JM Magalhães LC Coelho ZA Paixao ML Gontijo AP Fonseca ST 《Arquivos de neuro-psiquiatria》2002,60(2-B):446-452
OBJECTIVE: To compare the pattern of self-care performance in normal children and children with cerebral palsy (CP). METHOD: 142 normal children and 33 children with CP were evaluated by 22 items from the self-care scale of the PEDI functional test. Rasch methodology transformed scores into interval measures of difficulty from 0 to 100 (logit). Spearman rank correlation coefficient compared the order of logits in the two groups. RESULTS: Eleven items showed significant differences in the logit values received. Out of these, 7 items showed relative difficulty values greater in the group of children with CP and 4 items showed relative difficulty values greater among normal children. A significant correlation was observed in the order of the 22 items displayed in the two interval scales. CONCLUSION: The results suggest that the development of self-care functional activities may be influenced by the presence of CP. These results may support assessment and intervention strategies for children with neuromotor disorders. 相似文献
106.
107.
Adult intestinal allografts have demonstrated high immunogenicity in human transplantation, making the search for new and
more favorable grafts an actual problem. Accepting that fetal and newborn immune systems are relatively immature, their intestines
could be ideal sources for organ donation. The purpose of this study was to compare the immunogenicity of fetal, newborn,
and adult intestine for selection of the least antigenic. Using a bidirectional rat model for immunologic responses, 116 small-bowel
transplantations were done: 36 fetal, 40 newborn, and 40 adult grafts. Two histocompatibility barriers and different immunosuppression
regimes were used. For fetal and newborn intestines, free grafts into the omentum of adult recipients were done; for adult
intestines, accessory grafts in adult recipients of the same age, using vascular anastomoses. The diagnosis of graft rejection
and graft-versus-host disease (GVHD) was based on histology of hematoxylin and eosin-stained biopsies from target organs.
Recipients of fetal and newborn grafts did not show signs of GVHD, while 12% of the adult group did (P < 0.05). Rejection was less severe in fetal and adult (P > 0.05) than in newborn (P < 0.05) intestinal transplantation. Treatment with 10 mg/kg per day cyclosporine prevented rejection in 70% of fetal and
75% of adult grafts, while all newborn grafts were rejected. Under no immunosuppression, or with low doses of cyclosporine
(2 mg/kg per day), all groups showed histologic signs of rejection in almost all cases, the fetal intestine being the least
affected. Concerning histocompatibility barriers, grafts were usually less damaged in the weaker transplantation subgroups.
Our data indicate that fetal intestine is the least immunogenic of the three grafts studied, suggesting that it will be the
most suitable tissue for organ donation.
Accepted: 8 November 1999 相似文献
108.
109.
The theme of the present study emerged from the experience that we have in our professional practice, where we could observe the absenteeism of nursing professionals related to diseases, what woke up us the interest in deepening in the nurse's paper in the preventive actions related to the nursing worker's health in his/her professional path comparing them with the Regulatory Norms. The preventive actions in the worker's health is a constant search, that needs more investment with the objective of improving the work conditions, providing a healthy atmosphere. 相似文献
110.
Quantitative perfusion measurements using pulsed arterial spin labeling: effects of large region-of-interest analysis 总被引:5,自引:0,他引:5
PURPOSE: To study arterial spin labeling (ASL) MRI techniques and to investigate various problematic issues that still hinder the accurate and robust quantitative analysis of ASL data. MATERIALS AND METHODS: A pulsed-ASL (PASL) sequence was implemented on a 3-T imaging system and a protocol was developed for the measurement of perfusion based on fitting to a standard kinetic model. Both numerical simulations and multi-inversion time MRI data were analyzed. The effect of fitting a kinetic curve to a large region of interest (ROI) with a distribution of arterial transit times was compared to a pixel-by-pixel (PBP) method. RESULTS: It was found that a significant underestimation of perfusion of approximately 17+/-6% (P<0.001) occurs in gray matter, when comparing an ROI with a PBP analysis over a group of 12 healthy subjects. CONCLUSION: Analysis of ASL data based on a large ROI may suffer from inaccuracies arising from a distribution of transit times, implying that averaging of ASL kinetic data over such regions should therefore be avoided. When possible, a PBP fit should be performed. 相似文献