全文获取类型
收费全文 | 9394篇 |
免费 | 707篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 158篇 |
儿科学 | 373篇 |
妇产科学 | 370篇 |
基础医学 | 1329篇 |
口腔科学 | 455篇 |
临床医学 | 946篇 |
内科学 | 1494篇 |
皮肤病学 | 273篇 |
神经病学 | 874篇 |
特种医学 | 299篇 |
外科学 | 1437篇 |
综合类 | 141篇 |
一般理论 | 3篇 |
预防医学 | 754篇 |
眼科学 | 214篇 |
药学 | 524篇 |
中国医学 | 13篇 |
肿瘤学 | 454篇 |
出版年
2021年 | 144篇 |
2020年 | 76篇 |
2019年 | 136篇 |
2018年 | 151篇 |
2017年 | 106篇 |
2016年 | 138篇 |
2015年 | 138篇 |
2014年 | 204篇 |
2013年 | 269篇 |
2012年 | 361篇 |
2011年 | 428篇 |
2010年 | 228篇 |
2009年 | 235篇 |
2008年 | 348篇 |
2007年 | 404篇 |
2006年 | 433篇 |
2005年 | 373篇 |
2004年 | 358篇 |
2003年 | 283篇 |
2002年 | 291篇 |
2001年 | 310篇 |
2000年 | 285篇 |
1999年 | 256篇 |
1998年 | 97篇 |
1997年 | 92篇 |
1996年 | 79篇 |
1995年 | 90篇 |
1994年 | 78篇 |
1993年 | 83篇 |
1992年 | 209篇 |
1991年 | 174篇 |
1990年 | 216篇 |
1989年 | 203篇 |
1988年 | 206篇 |
1987年 | 192篇 |
1986年 | 178篇 |
1985年 | 167篇 |
1984年 | 138篇 |
1983年 | 118篇 |
1979年 | 118篇 |
1978年 | 89篇 |
1977年 | 79篇 |
1975年 | 88篇 |
1974年 | 91篇 |
1973年 | 90篇 |
1972年 | 78篇 |
1971年 | 86篇 |
1970年 | 83篇 |
1969年 | 77篇 |
1968年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Bilateral idiopathic inflammation of the optic nerve sheaths. Light and electron microscopic findings 总被引:1,自引:0,他引:1
Idiopathic perioptic neuritis is a term used to describe noninfectious inflammatory disorders of the optic nerve sheaths, the causes of which are unknown. In the following report, a 68-year-old woman with bilateral visual loss was found to have chronic inflammation with necrobiotic granulomas of her optic nerve sheaths. The patient, who had no systemic condition known to be associated with necrobiotic granuloma, lost vision from infarction of the optic nerve parenchyma and from compression due to thickened meninges. Although there are similarities between the inflammatory reaction in this case to the necrobiotic dermatoses, the pathogenesis of this condition remains obscure. 相似文献
22.
Kevin L Moss James D Beck Sally M Mauriello Steven Offenbacher Raymond P White 《Journal of oral and maxillofacial surgery》2007,65(5):958-963
PURPOSE: This study was designed to identify risk indicators for the prevalence at enrollment and incidence over 36 months of periodontal pathology and coronal caries experience affecting third molars in a community-based study of people over 65 years of age. SUBJECTS AND METHODS: Data from a subsample of 810 dentate subjects from the Piedmont 65+ Study were available for analyses. All visible teeth were examined. Periodontal probing measures were taken at 2 sites, mesiobuccal and buccal/facial. Clinical data on caries experience were collected by visual-tactile examination. At enrollment, 340 subjects had at least 1 visible third molar; all were examined for caries experience. Periodontal probing measures were available for 277 of these same subjects. The significance of the possible risk indicators for periodontal pathology and caries affecting third molars was determined by chi(2) tests. Statistical significance was set at .05. Logistic multivariable models were used to derive odds ratios and 95% confidence intervals. RESULTS: African-American subjects were more likely to have visible third molars (P < .01). Caucasian subjects were more likely to have third molar coronal caries experience (P < .01), as were subjects with greater than a high school education and those with a dental visit within 3 years (both P < .01). However, African American subjects were more likely to have periodontal pathology, CALs >/= 3 mm on third molars (P < .01), as were those who used tobacco (P < .01). None of the other risk indicators we studied were associated with progression of periodontal pathology or coronal caries experience on visible third molars. CONCLUSION: In this population study of senior adults, Caucasians and African Americans appear to have different levels of risk for caries experience and periodontal pathology affecting retained third molars. 相似文献
23.
24.
25.
Surgical glove powders bind latex antigens. 总被引:4,自引:0,他引:4
Latex surgical gloves have recently been identified as a potential source of allergens. Much of the current information suggests that the soluble proteins in latex may cause significant reactions in sensitive individuals. The starch powders used as a lubricant on some latex gloves have also been identified as potential allergens in some patients. In this study, we determined these powders to act as potential carriers of latex allergens. We have produced a polyclonal antiserum to be used as a reagent to study latex proteins. By Western blot analysis, we identified a significant interaction between latex proteins and starch powders. The binding of latex proteins to starch particles results in a glove particle that may have an increased potential to act as an allergen. The latex protein-starch particles represent a potential mechanism for exposure and sensitization of health care workers to latex allergens. Elimination of these particles from the operating room should reduce the route of sensitization and the potential for adverse reactions to latex. 相似文献
26.
S G Beck 《Synapse (New York, N.Y.)》1992,10(4):334-340
In the presence of spiperone to block the 5-HT1A-mediated inhibition of pyramidal cell activity, 5-hydroxytryptamine (serotonin, 5-HT) produces a rapid transient increase in amplitude of the extracellularly recorded population spike from area CA1 of the hippocampus. Intracellular recording techniques in area CA1 of rat hippocampal slices were used to identify the ionic mechanism and to characterize the 5-HT receptor mediating this excitatory response to 5-HT. Most of the experiments were conducted in the presence of spiperone to block the 5HT1A hyperpolarization. Since spiperone also has high affinity for 5-HT2 receptors, any response mediated by 5-HT2 receptors would also be blocked. Bath perfusion of the slice with 5-HT increased the rectification of pyramidal cells in the subthreshold region, increased the resistance, and increased the amplitude of subthreshold excitatory postsynaptic potentials (EPSPs) to initiate spike firing. The 5-HT2,1C-selective agonist DOI mimicked this effect of 5-HT, and the 5-HT2,1C antagonist ketanserin (1 microM) blocked the effect of DOI. There was no change in the amplitude of the slow afterhyperpolarization (sAHP) or the amplitude of evoked inhibitory postsynaptic potentials (IPSPs). The increase in rectification and EPSP amplitude by 5-HT occurred even in the presence of the 5-HT4-selective antagonist BRL 24924 to prevent the decrease in amplitude of the sAHP by 5-HT. We conclude that 5-HT produces a fast excitatory response by increasing subthreshold conductance in CA1 hippocampal pyramidal cells. The identity of the receptor mediating this response was not conclusively identified, but resembled the 5-HT1C receptor. 相似文献
27.
The peripheral vascular response to Escherichia coli endotoxin (1 mg/kg/i.v.) was measured for 2 hr in the pentobarbital anesthetized dog. Total venous return was collected and returned by a pump to the right atrium to maintain a constant cardiac output. Occlusion of the venous lines permitted estimation of venous compliance in the systems drained by the superior (SVC) and inferior vena cavae (IVC). After endotoxin administration, arterial pressure and total peripheral resistance rapidly dropped and remained low for 2 hr. IVC compliance was decreased at 10-30 min and SVC compliance at 10 min after endotoxin. The decrease in compliance is interpreted as venous dilation and probably venous pooling. The latter may account for a substantial portion of the total venous pooling reported in early endotoxin shock. After 30 min, compliance increased and by 60 min was equal to control. Left ventricular relaxation ability decreased as indicated by maximal negative dp/dt. Ibuprofen, 10 mg/kg, was administered at 120 min or earlier, depending on the state of the animal; rapid recovery of arterial pressure and ventricular function occurred without a significant change in venous compliance. 相似文献
28.
Multiple aspects of family functioning were assessed when mothers experienced either chronic pain, a chronic illness (diabetes), or no illness. Mothers' and fathers' self-report measures of depression, anxiety, and family environment were collected. Children's self-report measures of depression and anxiety, as well as information about their overall adjustment, were collected. Family communication patterns were also assessed. Families with a mother who had chronic pain had poorer perceived family environments and higher levels of depression and anxiety compared to the other two groups of families. Children from chronic pain families also appeared to be adversely affected. The data suggest that level of disability appeared more salient than the type of chronic illness. Implications of the findings are discussed in light of the fact that mothers with chronic pain in the present sample reported relatively mild disability and were not actively seeking treatment for their condition. 相似文献
29.
30.
The frequency of type I heterozygous protein S and protein C deficiency in 141 unrelated young patients with venous thrombosis 总被引:7,自引:0,他引:7
The frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (less than 45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C deficiencies (9%) emerge as the leading identifiable associated abnormalities. 相似文献