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This study was designed to determine the ulcer-protecting effects of rutin, a natural flavone, against gastric lesions induced by 50% ethanol, the experimental model related to lesion pathogenesis with production of reactive species. The possible involvement of sulphydryl compounds (SH), neutrophil infiltration, and the capacity of this flavone to restrain the oxidative process produced in the gastric tissue were also investigated. The levels of thiobarbituric acid (TBA, as index of lipid peroxidation), the myeloperoxidase activity (MPO, as a marker of neutrophil infiltration), the content of mucosal sulphydryls (SH) groups and the activity of glutathione peroxidase (GSH-Px, an important antioxidant enzyme) were determined. Pretreatment with the highest dose of rutin (200 mg/kg), 120 min before 50% ethanol, resulted in the most effective necrosis prevention. TBA reactive substances in the gastric mucosa, were increased by ethanol injury, and this increase was inhibited by the administration of 200 mg/kg of rutin. However, the flavonoid was not able to modify the ethanol-induced neutrophil infiltrate expressed as myeloperoxidase activity. Exposure of the gastric mucosa to 50% ethanol induced a significant diminution in gastric non-protein SH content; this parameter also was not modified by the treatment with rutin. GSH-Px activity decreased in the gastric mucosa after ethanol-treatment. In contrast, rutin at all tested doses induced a significant increase in this enzymatic activity, higher than in control group. These results suggest that the gastroprotective effect of rutin in this experimental model appears through an anti-lipoperoxidant effect, and also by enhancement of the anti-oxidant enzymatic (GSH-Px) activity.  相似文献   
74.
Free radicals are involved in ischemia-reperfusion injury and inflammatory processes. The commercial formulation of the anesthetic propofol contains -tocopherol and -tocopherol, which may exert antioxidant effects during transplantation. Animals were randomly assigned to a control group or experimental groups for lung transplantation after 3 and 24 h of ischemia. Individual tocopherols, malondialdehyde, biochemical indices, and hemodynamic, blood gas, and ventilatory parameters were determined during reperfusion. Results showed that administration of commercially available propofol provoked a time- and dose-dependent increment in serum -tocopherol and -tocopherol in control animals and in the group receiving lungs subjected to 3 h of ischemia, but not in the group with 24 h of ischemia. Malondialdehyde levels increased during reperfusion and did not differ significantly between the two experimental groups, which did not differ with respect to lung function either. -Tocopherol, supplied by the anesthetic, may act as an antioxidant that is consumed during reperfusion. This potential effect could be relevant to the choice of anesthetic agents in situations where free radical damage to tissues is expected.  相似文献   
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The use of biological materials in the construction of bioprostheses requires the application of different chemical or physical procedures to improve the mechanical performance of the material without producing any undesirable effects. A number of cross-linking methods have been tested in biological tissues composed mainly of collagen. The basis for most of them is the use of glutaraldehyde (GA), which acts on the Lys or Hyl residues. We have studied the effects of alternative chemical treatments: diphenylphosphorylazide (DPPA) and ethyldimethylaminopropyl carbodiimide (EDAC). Their mechanism of action is based on the activation of the carboxyl groups, which then permits their cross-linking to amino groups. As a control, we employed conventional treatment with GA, applying it to bovine pericardium and collagen membranes removed from bovine pericardium. The analysis of the Lys and Hyl residues showed that DPPA and EDAC produced 50% of the chemical change provoked by GA. This value was even lower in the trials with collagen. In terms of the resistance to collagenase degradation, chemical cross-linking with GA provided much greater protection in both materials (3.81 +/- 3.47 nmol of amino acid/mg dry tissue for pericardium and 4.41 +/- 1.13 nmol of amino acid/mg dry tissue for collagen). Treatment with DPPA also protected pericardium (13.11 +/- 6.57 nmol amino acid/mg dry tissue) although the values for collagen was lower (50.0 +/- 32.4 nmol amino acid/mg dry tissue). Treatment with EDAC was much less protective than the other two chemical reagents (43.28 +/- 17.4 and 55.85 +/- 14.57 nmol amino acid/mg dry tissue for pericardium and collagen, respectively). The degree of tissue calcification after implantation of the chemically treated materials into young rats was considerably greater for GA and DPPA (32.9 +/- 18.8 and 36.3 +/- 13.3 mg g(-1) dry tissue, respectively) than with EDAC (18.0 +/- 7.2 mg g(-1) dry tissue; P < 0.001). After 60 days of implantation, the values for GA and EDAC were higher(124.1 +/- 31.3 and 124.6 +/- 21.0 mg g(-1) dry tissue, respectively) versus 34.6 +/- 19.2 mg g(-1) dry tissue for DPPA. There were no significant differences in collagen levels in samples treated with GA or EDAC after 30 days of implantation, although both groups showed significant differences when compared with DPPA-treated samples (P < 0.001). After 60 days of implantation, there were no significant differences among these three treatments in terms of the calcium accumulated on samples.  相似文献   
77.
A cross-sectional case-control study was performed to identify some obstetric and gynaecologic factors that can influence spontaneous abortion. Statistical and epidemiologic analyses were done by multiple logistic regression to adjust OR through the coefficient. A dicotomized outcome variable, representing spontaneous abortion, and different independent variables, representing distinct medical factors, were designed. The analysis was carried out with a personal computer and an appropriate statistic package.The variables representing age over 35 and previous spontaneous abortions were shown to be risk factors, adjusted for the rest of variables. The variables representing parity and late menarcheal age lost significance when they were adjusted with multiple logistic regression.Corresponding author.  相似文献   
78.
A comparative morphometrical study of the experimental infection with T. b. brucei was realized using the conventional method and the IBAS-1 analytic computer. The studied strain of T. b. brucei was preserved during 10 years in laboratory conditions, through inoculations from mice to mice. The effect of a low dose of suramin upon the percentage of different morphological forms of the parasite was analysed and compared with the untreated lots. Certain differences could be appreciated in the results of the two methods of morphometrical studies. The presence of posteronuclear, multinuclear and "stumpy" dividing forms was confirmed in our study. The administration of low doses of suramin produces a serious increase of the number of the dividing, multinuclear and "stumpy" forms.  相似文献   
79.
Anorexia nervosa (AN) is a very extended pathology among adolescent girls nowadays. These patients show a high degree of osteopenia; hence, study of their bone remodelling is of great interest. Serum bone alkaline phosphatase (bAP) and aminoterminal propeptide of procollagen I (PINP) provide good sensitivity in the analysis of bone alterations in postmenopausal osteoporosis. The aim of this study was to compare the usefulness of bAP and PINP in the study of bone remodelling in AN, and their possible correlation with the degree of osteopenia in this pathology. In order to help in the interpretation of the results, levels of the beta-isomer of urinary carboxyterminal propeptide of collagen I (beta-CTX) have also been included. Serum bAP (IRMA) Tandem R-Ostase, Hybritech), PINP (RIA, Orion Diagnostica) and CTX (CrossLaps ELISA, Osteometer) were determined in 41 girls with AN, aged 18.5+/-2.2 years (mean+/-SD) and in 31 healthy control women, aged 19+/-2.3 years. Bone mineral density (BMD) in lumbar spine was measured by DEXA in the AN group. We found that 41 of the 43 patients had BMD z-scores under -2. No significant differences were found in the levels of serum bAP nor in PINP and beta-CTX levels between controls and patients, although values in the AN group were highly variable. All the BMD z-score values were negative, and their absolute value correlates positively with bAP (P = 0.0279) and almost with beta-CTX (P = 0.0921) but not with PINP (P = 0.4627). Bone AP correlates with PINP in control girls (P = 0.017), but not in the AN group (P = 0.3573). Patients with AN were divided into three groups according to their levels of bAP: low (I), normal (II) or high (III). Patients with the highest bAP levels also presented the highest increase in bone resorption, according to their beta-CTX levels, and the highest degree of osteopenia. However, values of PINP were similar in the three groups of patients. The bAP/beta-CTX ratios in subgroups I, II and III of AN patients were 0.035, 0.065 and 0.073, a finding that suggests that bAP is not indicating the real degree of bone mineralization in these patients, because it is a contradiction that the formation/resorption ratio should be higher in the patients who have the highest bone loss. These results could suggest that bone loss in AN is produced by an increase in bone resorption (beta-CTX), without variations in bone matrix formation (PINP); bAP levels are a good marker in the follow-up of osteopenia degree, but not a real indicator of bone mineralization, a similar situation to that of osteomalacia.  相似文献   
80.
To estimate the potential benefits of cardiovascular disease intervention programs in Spain, we have computed cardiovascular population mortality fractions and deaths attributable to the main risk factors by using relative risks from international studies and Spanish prevalence and mortality data (subjects of both sexes, aged 25-64). As many as 71% of the cardiovascular deaths studied in men and 44% in women might be delayed every year in Spain if it were possible to eliminate the current exposure of the population to smoking, obesity, sedentariness, hypertension and hypercholesterolemia. With the eradication of tobacco exposure 31% of coronary deaths and 16% of stroke deaths in men (7% in both cases for women) might be avoided. Similar actions on sedentariness, hypertension and hypercholesterolemia might delay 17% and 29%, 13% and 13%, and 9% and 11% of deaths, respectively, in males (figures generally somewhat higher in females). These figures would be moderately lower if reductions in the prevalence of these factors are considered realistically. These results may encourage the implementation of strategies against cardiovascular diseases in countries with risk factor prevalence similar to that of Spain.  相似文献   
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