全文获取类型
收费全文 | 22739篇 |
免费 | 1624篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 770篇 |
妇产科学 | 523篇 |
基础医学 | 3303篇 |
口腔科学 | 328篇 |
临床医学 | 2776篇 |
内科学 | 4997篇 |
皮肤病学 | 480篇 |
神经病学 | 2396篇 |
特种医学 | 386篇 |
外科学 | 2005篇 |
综合类 | 128篇 |
一般理论 | 28篇 |
预防医学 | 2522篇 |
眼科学 | 246篇 |
药学 | 1530篇 |
中国医学 | 43篇 |
肿瘤学 | 1838篇 |
出版年
2024年 | 20篇 |
2023年 | 215篇 |
2022年 | 387篇 |
2021年 | 763篇 |
2020年 | 509篇 |
2019年 | 759篇 |
2018年 | 783篇 |
2017年 | 576篇 |
2016年 | 651篇 |
2015年 | 713篇 |
2014年 | 909篇 |
2013年 | 1189篇 |
2012年 | 1937篇 |
2011年 | 1944篇 |
2010年 | 1036篇 |
2009年 | 872篇 |
2008年 | 1512篇 |
2007年 | 1562篇 |
2006年 | 1539篇 |
2005年 | 1423篇 |
2004年 | 1313篇 |
2003年 | 1162篇 |
2002年 | 1018篇 |
2001年 | 137篇 |
2000年 | 86篇 |
1999年 | 148篇 |
1998年 | 191篇 |
1997年 | 136篇 |
1996年 | 133篇 |
1995年 | 121篇 |
1994年 | 82篇 |
1993年 | 86篇 |
1992年 | 43篇 |
1991年 | 43篇 |
1990年 | 41篇 |
1989年 | 48篇 |
1988年 | 33篇 |
1987年 | 23篇 |
1986年 | 31篇 |
1985年 | 26篇 |
1984年 | 39篇 |
1983年 | 26篇 |
1982年 | 24篇 |
1981年 | 25篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1978年 | 14篇 |
1976年 | 16篇 |
1973年 | 12篇 |
1971年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Rosangela Saga Kamikawa Marlene Fenyo Pereira Angela Fernandes Maria Inês Meurer 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,101(3):374-378
OBJECTIVE: To determine the location in soft tissues of the calcifications, similar to calcified carotid atheromas, that can be observed radiographically in the cervical region in panoramic radiographs. STUDY DESIGN: In each anatomic cadaver specimen preserved in formol, consisting of the head and neck, radiopaque spheres (made from gutta-percha) were positioned in anatomic structures of the cervical region that can be sites of calcification. For each anatomic structure marked in this way, panoramic radiography was performed, consisting of 17 radiographs. The images obtained were analyzed by 24 examiners who indicated which radiographs, in their opinion, presented the radiopaque reference projected in the region of bifurcation of the carotid artery. Analysis of 2 proportions from agreement and disagreement was used to determine radiopacities that could be confused in panoramic radiographs with calcified atheromas in the carotid artery. RESULTS: The results showed that 75% (18) of the examiners correctly indicated the reference in the bifurcation of the carotid artery and 79.2% (19) indicated a triticeous cartilage as calcified atheroma of the carotid artery. CONCLUSIONS: Calcified atheromas of the carotid artery are not the only features that can produce radiopaque images lateral to the panoramic radiograph; the presence of calcification in the triticeous cartilage also can induce an erroneous diagnosis of calcified carotid atheroma. 相似文献
12.
A survey of 402 normal subjects (203 men, 199 women) was conducted to assist in distinguishing potential differences in norms of hand strength. Norm data had previously been collected from mixed occupational groups, but in the present study it was hypothesised that people involved in heavy manual work on a daily basis might possess greater hand strength than others. The volunteers were adults working in industry and agriculture; they were subdivided into occupational categories. Measurements of grip, key and palmar pinch using the Jamar dynamometer and B and L pinch gauge were collected, using the protocol described by Mathiowetz. Volunteers also rated their individual hand strength job requirements subjectively. Mean values were established with regard to age, sex, dominance, occupational group and subjective rating. Significant differences were found with regard to age and sex but not to dominance; there was no evidence of differences between occupational groups or between subjective rating and individual scoring, i.e. volunteers who perceived their job as requiring a high degree of strength did not achieve higher test measurements than others. A high interrater reliability was demonstrated when comparing these follow-up measurements with the original data. It was concluded that, for clinical and rehabilitative purposes, therapists can interpret assessment of outcome most accurately by comparing patients' results with the existing norm data. 相似文献
13.
14.
Christina Djokoto George Tomlinson Stephen Waldman Marc Grynpas Angela M. Cheung 《Journal of clinical densitometry》2004,7(4):448-456
Dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) are the accepted modalities for the evaluation of fracture risk in the clinical setting. However, neither method provides a direct measurement of bone mechanics. In this study, we investigated a prototype device, known as a mechanical response tissue analyzer (MRTA), which provides direct mechanical measurements of mechanical properties of bone. A total of 56 healthy volunteers (20 men and 36 women) between the ages of 18 and 83 were recruited. The MRTA was used to measure the cross-sectional bending stiffness (EI) of the ulna bone. Axial speed of sound (SOS) at the ulna bone was determined by QUS; bone mineral content (BMC) and bone mineral density (BMD) were determined by DXA. Correlations, regression analysis, and analyses of variance (ANOVAs) were used to compare the three modalities. These analyses revealed that although there are strong linear relationships among the data collected by the various technologies, the bone properties reflected by MRTA are not fully explained by DXA and QUS. We conclude that the total information conveyed by MRTA measurements is unique. Further research is needed to delineate the different qualities of bone strength that are captured by MRTA, but not by DXA or QUS. 相似文献
15.
BACKGROUND: Delays in seeking treatment for signs and symptoms of acute myocardial infarction are longer for African Americans than for whites. OBJECTIVE: To determine factors associated with prolonged delay and the extent to which perceived racism influences prehospital delay in African Americans with acute myocardial infarction. METHODS: Sixty-one African Americans with acute myocardial infarction were interviewed within 1 month of hospital admission. Delay times were calculated on the basis of the interviews. Independent t tests and chi(2) tests were used to determine factors associated with prolonged delays. RESULTS: Median delay was 4.25 hours and did not differ significantly between women and men (4.42 vs 3.50 hours). Most patients (69%) experienced their initial signs and symptoms at home, often witnessed by family members or friends (70%). Delay was longer for insured patients than for uninsured patients (4.45 vs 0.50 hours). Single, widowed, or divorced patients had longer delay times than did married patients (5.33 vs 2.50 hours), and patients with diabetes delayed longer than did those without diabetes (7.29 vs 3.50 hours). Perceived racism did not differ significantly between patients who delayed seeking treatment and those who did not. CONCLUSIONS: Median delay times were substantially longer than the recommended time of less than 1 hour, reducing the benefit from reperfusion therapies. Education and counseling of patients and their families should be a major strategy in optimizing patients' outcomes and decreasing the time to definitive treatment. 相似文献
16.
17.
Mary T Fox Angela Cooper Brathwaite Souraya Sidani 《Revue canadienne de recherche en sciences infirmières》2004,36(3):20-30
Repeated measures designs are often used to evaluate the effectiveness of interventions. In these designs, the outcomes are measured on several occasions before and after implementation of the intervention. Two statistical methods, the repeated measures analysis of variance (RM-ANOVA) and hierarchical linear models (HLM), can be used to analyze the data. The authors provide an overview of the statistical models underlying RM-ANOVA and HLM and discuss the strengths and limitations of each. They propose that the 2 methods are complementary in determining the effectiveness of interventions. 相似文献
18.
19.
Giuseppe Derosa Arrigo F G Cicero Angela D'Angelo Pietro D Ragonesi Leonardina Ciccarelli Mario N Piccinni Fabio Pricolo Sibilla A T Salvadeo Ilaria Ferrari Alessia Gravina Roberto Fogari 《Hypertension research》2006,29(11):849-856
The aim of our study was to investigate the metabolic effect of telmisartan and irbesartan in subjects treated with rosiglitazone, a well-known insulin-sensitizing drug, in order to clarify the direct metabolic effects of the two former drugs. Patients were enrolled, evaluated, and followed at 3 Italian centers. We evaluated 188 type 2 diabetic patients with metabolic syndrome (94 males and 94 females in total; 49 males and 46 females, aged 56+/-5, treated with telmisartan; and 45 males and 48 females, aged 55+/-4, treated with irbesartan). All had been diabetic for at least 6 months, and glycemic control by the maximum tolerated dietary changes and maximum tolerated dose of oral hypoglycemic agents had been attempted and failed in all cases. All patients took a fixed dose of rosiglitazone, 4 mg/day. We administered telmisartan (40 mg/day) or irbesartan (150 mg/day) in a randomized, controlled, double-blind clinical manner. We evaluated body mass index (BMI), glycemic control (HbA1c fasting plasma glucose and insulin levels [FPG, and FPI, respectively], and homeostasis model assessment [HOMA] index), lipid profile (total cholesterol [TC], low density lipoprotein-cholesterol [LDL-C], high density lipoprotein-cholesterol [HDL-C], and triglycerides [TG]), systolic and diastolic blood pressure (SBP and DBP), tumor necrosis factor-alpha (TNF-alpha), and leptin during the 12 months of this treatment. No BMI change was observed after 6 or 12 months in either group. Significant decreases in HbAlc and FPG were observed after 6 months in the telmisartan group, and after 12 months in both groups. The decrease in HbA1c and FPG at 12 months was statistically significant only in the telmisartan group. A significant decrease in FPI was observed at 12 months in both groups, and this decrease was significantly greater in the telmisartan group. Significant decreases in the HOMA index were observed at 6 and 12 months in both groups, and the decrease in the HOMA index after 12 months was significantly greater in the telmisartan group than in the irbesartan group. Significant changes in SBP, DBP, TC, and LDL-C were observed after 6 and 12 months in both groups. Significant decreases in TNF-alpha and leptin levels were observed after 6 months in the telmisartan group, and after 12 months in both groups. In conclusion, in this study of patients with type 2 diabetes mellitus and metabolic syndrome, telmisartan seemed to result in a greater improvement in glycemic and lipid control and metabolic parameters related to metabolic syndrome compared to irbesartan. These observed metabolic effects of different angiotensin type 1 receptor blockers could be relevant when choosing a therapy to correct metabolic derangement of patients affected by metabolic syndrome and diabetes. 相似文献
20.