全文获取类型
收费全文 | 235篇 |
免费 | 21篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 6篇 |
妇产科学 | 5篇 |
基础医学 | 21篇 |
口腔科学 | 7篇 |
临床医学 | 37篇 |
内科学 | 48篇 |
神经病学 | 11篇 |
特种医学 | 46篇 |
外科学 | 32篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 23篇 |
眼科学 | 2篇 |
药学 | 7篇 |
1篇 | |
肿瘤学 | 5篇 |
出版年
2021年 | 2篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 8篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 9篇 |
1998年 | 16篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 9篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1970年 | 3篇 |
1968年 | 2篇 |
1966年 | 3篇 |
1964年 | 1篇 |
1947年 | 1篇 |
1945年 | 1篇 |
1928年 | 1篇 |
1925年 | 1篇 |
排序方式: 共有258条查询结果,搜索用时 312 毫秒
61.
Kevin?CarrEmail authorView authors OrcID profile Dustin?Tew Luis?Becerra Kristina?Siddall Laurence?Dubensky Yafell?Serulle 《Neuroradiology》2018,60(10):1103-1107
Free-floating thrombi of the common carotid artery (CCA) are a very rare cause of ischemic stroke. To date, only a few reports have been described in the academic literature. Revascularization is indicated due to the risk of thromboembolic disease and hemodynamic-related stroke syndromes. Medical treatment typically includes anticoagulation and, in some circumstances, open surgical thrombectomy is an additional option. Although rarely described in the literature, endovascular thrombectomy is a viable treatment alternative in these patients. 相似文献
62.
Siddall R 《The Health service journal》2000,110(5733):suppl 8-suppl 9
63.
Indications for breast imaging in women under age 35 years 总被引:1,自引:0,他引:1
To determine appropriate indications for breast imaging in young women, the authors correlated patient histories with mammographic and/or sonographic findings and biopsy or follow-up results for 625 patients aged 13-34 years. The only important indications were a palpable mass and suspicion of an abscess. Of the 335 studies performed for evaluation of a palpable mass, 184 (55%) were normal, 28 (8%) were compatible with benign disease, and 123 (37%) were suggestive of malignancy. Biopsies were performed in 73 patients; the findings were benign in 67 cases, and carcinoma was found in six. Imaging studies were considered helpful in four of the 15 cases of suspected abscess, in that the studies established the presence and extent of an abscess. Studies in 275 women were performed for a variety of other indications. The findings were normal in 239 (87%) studies, benign in 21 (8%), and suggestive of malignancy in 15 (5%); there were no known carcinomas in any of the patients. Women with the "low-yield" indications identified in this study should be followed up clinically rather than referred for imaging studies. 相似文献
64.
Objectives: Asthma is a chronic respiratory condition with a U.S. prevalence of 7.4%. Despite numerous treatment options, asthma remains poorly controlled in some patients. Uncontrolled asthma is associated with high healthcare resource utilization (HCRU) and reduced productivity. This study assessed symptoms, productivity, and HCRU of patients adherent to medium/high-dosage inhaled corticosteroid/long-acting beta2-agonist (ICS/LABA) treatment, and the relationship of asthma control with these parameters. Methods: Data were collected in the U.S. in 2013–2016 in the Adelphi Respiratory Disease Specific Programme, a cross-sectional survey. Participating physicians (n = 258) each completed a record form for eligible patients, who were receiving medium/high-dosage ICS/LABA treatment with self-reported moderate/high adherence, completed the Asthma Control Test (ACT) and the Work Productivity and Activity Impairment (WPAI) questionnaire, and were included in the analyses. Results: Patients (n = 428) had a mean of 59% symptom-free days in the past month. Wheezing was the most troublesome symptom for 25% of patients. In the previous 12 months, the mean number of exacerbations was 1.3; 15% of exacerbations required emergency room treatment and/or hospitalization. Mean physician visits for asthma was 5.7. Asthma impacted leisure/personal time frequently/constantly for 11% of patients, with 20% overall work impairment. Asthma was poorly controlled (ACT score ≤15) in 18% of patients; poorer asthma control was associated with higher rates of exacerbations, work impairment, and HCRU. Conclusion: Given the substantial burden described, greater attention to asthma monitoring and management is necessary. Identification of novel treatments may be important for patients not responding to medium/high-dosage ICS/LABA treatment. 相似文献
65.
66.
Irradiation induces release of von Willebrand protein from endothelial cells in culture 总被引:3,自引:0,他引:3
Human umbilical vein endothelial cells in tissue culture were irradiated with doses between 0 and 40 Gy, and the released von Willebrand (vW) protein and that which remained associated with the cells was quantitated. Doses of 20 Gy and higher produced a statistically significant increase in amount of vW protein secreted. This release was present whether the cells were labeled continuously throughout the experiment or just prelabeled before irradiation. An increase in fibronectin secretion was not observed. The release response to radiation was slow, reaching significance close to 24 hours after irradiation. The release of vW protein was not due to cell lysis, because the secreted vW protein contained very little of the large 260- kilodalton vW precursor subunit present in cell lysates and the cells appeared intact by immunofluorescence staining. 相似文献
67.
Isolation, Structure, and Absolute Configuration of a New Natural Insect Juvenile Hormone from Manduca sexta
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Judy KJ Schooley DA Dunham LL Hall MS Bergot BJ Siddall JB 《Proceedings of the National Academy of Sciences of the United States of America》1973,70(5):1509-1513
Two juvenile hormones are isolated from organ cultures of corpora allata of the tobacco hornworm moth, Manduca sexta Johannson, and are purified by high-resolution liquid chromatography. These are identified as methyl (2E, 6E)-(10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate, a new natural hormone, and methyl (2E,6E) - (10R,11S) - 10,11 - epoxy - 3,7,11 - trimethyl-2,6-tridecadienoate. [14C]Methionine is incorporated only into their methoxycarbonyl group. Details of the in vitro techniques and the chemical proof of structures are presented. The significance of the occurrence of a new juvenile hormone and the new techniques used for production, isolation, and identification are discussed. 相似文献
68.
Comparing clinical outcomes in HIV‐infected and uninfected older men hospitalized with community‐acquired pneumonia
下载免费PDF全文
![点击此处可从《HIV medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
69.
70.
Metformin improves performance in high‐intensity exercise,but not anaerobic capacity in healthy male subjects
下载免费PDF全文
![点击此处可从《Clinical and experimental pharmacology & physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
SK Learsi VJ Bastos‐Silva AE Lima‐Silva R Bertuzzi GG De Araujo 《Clinical and experimental pharmacology & physiology》2015,42(10):1025-1029
The aim of this study was to determine the ergogenic effects of metformin in high‐intensity exercise, as well as its effects on anaerobic capacity, in healthy and physically active men. Ten subjects (mean (± standard deviation) maximal oxygen uptake (2max) 38.6 ± 4.5 mL/kg per min) performed the following tests in a cycle ergometer: (i) an incremental test; (ii) six submaximal constant workload tests at 40%–90% (2max); and (iii) two supramaximal tests (110% (2max). Metformin (500 mg) or placebo was ingested 60 min before the supramaximal test. There were no significant differences between the placebo and metformin groups in terms of maximum accumulated oxygen deficit (2.8 ± 0.6 vs 3.0 ± 0.8 L, respectively; P = 0.08), lactate concentrations (7.8 ± 2.6 vs 7.5 ± 3.0 mmol/L, respectively; P = 0.75) or O2 consumed in either the last 30 s of exercise (40.4 ± 4.4 vs 39.9 ± 4.0 mL/kg per min, respectively; P = 0.35) or the first 110 s of exercise (29.0 ± 2.5 vs 29.5 ± 3.0 mL/kg per min, respectively; P = 0.42). Time to exhaustion was significantly higher after metformin than placebo ingestion (191 ± 33 vs 167 ± 32 s, respectively; P = 0.001). The fast component of recovery was higher in the metformin than placebo group (12.71 vs 12.18 mL/kg per min, respectively; P = 0.025). Metformin improved performance and anaerobic alactic contribution during high‐intensity exercise, but had no effect on overall anaerobic capacity in healthy subjects. 相似文献