全文获取类型
收费全文 | 686篇 |
免费 | 64篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 31篇 |
妇产科学 | 13篇 |
基础医学 | 132篇 |
口腔科学 | 7篇 |
临床医学 | 68篇 |
内科学 | 176篇 |
皮肤病学 | 6篇 |
神经病学 | 77篇 |
特种医学 | 76篇 |
外科学 | 35篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 62篇 |
眼科学 | 1篇 |
药学 | 35篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 3篇 |
2022年 | 11篇 |
2021年 | 24篇 |
2020年 | 12篇 |
2019年 | 12篇 |
2018年 | 26篇 |
2017年 | 14篇 |
2016年 | 21篇 |
2015年 | 15篇 |
2014年 | 25篇 |
2013年 | 27篇 |
2012年 | 35篇 |
2011年 | 55篇 |
2010年 | 31篇 |
2009年 | 25篇 |
2008年 | 27篇 |
2007年 | 49篇 |
2006年 | 38篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 15篇 |
1998年 | 18篇 |
1997年 | 25篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 11篇 |
1993年 | 14篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 22篇 |
1988年 | 14篇 |
1987年 | 8篇 |
1986年 | 18篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1969年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有775条查询结果,搜索用时 0 毫秒
41.
Hartman E Oude Vrielink HH Huirne RB Metz JH 《Occupational medicine (Oxford, England)》2003,53(7):461-468
BACKGROUND: Agriculture is one of the most physically demanding and risky industries. Aim The objective of this study was to provide baseline data on the diagnoses, occurrence and duration of sick leave of self-employed Dutch farmers. METHOD: A database of 22 807 sick leave claims of 12 627 farmers during the period 1994-2001 was analysed. RESULTS: Most of the claims (61%) were for musculo-skeletal injuries and disorders. The mean cumulative incidence (CI) was 10.2 claims per year per 100 farmers and did not change over time. However, it varied per agricultural sector and per age category, being lowest in arable farming and in the youngest age category and highest in mushroom farming and in the oldest age category. The duration of sick leave depended both on diagnosis and age category: the slowest recovery from sick leave was seen in farmers with respiratory diseases and farmers in the oldest age category. CONCLUSION: The results make it easier to identify groups of farmers to be targeted to prevent sick leave. To reduce the occurrence of sick leave in agriculture, the strategy should be to prevent musculo-skeletal injuries and disorders. Furthermore, a sector-specific approach is recommended, so that preventive actions can be focused on working conditions-specifically on workload and work safety. Efforts to shorten the duration of sick leave will also be valuable to obtain a reduction of sick leave. 相似文献
42.
BACKGROUND: Factors determining the individual susceptibility to head and neck squamous cell carcinoma (HNSCC) are still largely unknown. An imbalance between enzymes involved in the toxification and detoxification of (pre)-carcinogens closely related to HNSCC, which may appear during smoking and alcohol consumption, may play a role. Genetic polymorphisms in glutathione S-transferases (GSTs) often result in altered detoxification, which may contribute to individual susceptibility to HNSCC. METHODS: We studied the frequencies of polymorphic variants in the GSTP1 gene in 235 patients with HNSCC and 285 healthy controls. In addition, data on exposure to alcohol and tobacco consumption were recorded. DNA was extracted from whole blood, and polymerase chain reaction-based methods were used to detect genetic polymorphisms. RESULTS: In patients with HNSCC and control groups, the homozygous GSTP1 BB genotype was observed in 12.3% and 13.6%, respectively. No statistical differences were found for the GSTP1 AA and GSTP1 AB/GSTP1BB genotypes. CONCLUSIONS: Our study showed that genetic polymorphisms of GSTP1 are not associated with altered susceptibility to HNSCC. 相似文献
43.
Oude Voshaar RC Gorgels WJ Mol AJ Couvée JE van Balkom AJ Zitman FG 《Nederlands tijdschrift voor geneeskunde》2001,145(28):1347-1350
Treatment strategies for discontinuing long-term benzodiazepine usage can be divided into minimal interventions and gradual discontinuation programs. Minimal interventions invite patients to quit their long-term benzodiazepine usage on their own by making them aware of the adverse effects. This type of intervention is successful in about one fifth of patients. Gradual discontinuation programs are more extensive interventions in order to help those patients who are unable to discontinue benzodiazepine use on their own. These programs are successful in two-thirds of the patients and can be combined with additional pharmacological or psychological treatment. Once the withdrawal symptoms have diminished, most patients have an improved psychological functioning compared to when they were using benzodiazepines. Furthermore, no increase in medical consumption has been found. 相似文献
44.
Role of MRP2 and GSH in intrahepatic cycling of toxins 总被引:7,自引:0,他引:7
MRP2 is a canalicular transporter in hepatocytes mediating the transport of a wide spectrum of amphipathic compounds. This includes organic anions but also compounds complexed with GSH as, e.g. alpha-naphthylisothiocyanate (ANIT) and arsenite. These reversible complexes may fall apart in bile after MRP2-mediated transport, which induces high concentrations of the toxic compound in the biliary tree. To further investigate the role of MRP2 in transport and toxicity of both compounds, we conducted experiments in transduced polarized epithelial cells and in vivo, using the Mrp2-deficient TR(-) rat as a model. Our results show, that in MRP2-transduced MDCK II cells both compounds induce disproportionally strong apical GSH secretion. This induction of GSH secretion was not observed in the parent cells lacking MRP2 expression. This indicated that after transport via MRP2 both complexes released GSH upon which the compound could re-enter the cells. The resulting cycling of both toxins led to concentration dependent GSH depletion of the cells. To further test our hypothesis we administered arsenite (12.5 micromol absolute i.v.) to Wistar and Mrp2-deficient TR(-) rats and collected bile. While both arsenite and GSH secretion were absent in TR(-) rats, the total secretion of arsenite into Wistar bile (2.91 micromol) was accompanied by a excess secretion of 24 micromol GSH, indicating that arsenite undergoes multiple cycles of GSH complexation. We also administered ANIT to both animal models and could show that TR(-) rats are protected from ANIT induced cholestasis. This indicates that Mrp2-mediated biliary secretion of GS-ANIT is a prerequisite for development of cholestasis in rats. We hypothesize that the toxic parent compound ANIT is regenerated in the biliary tree where it can exert its toxic properties on bile duct epithelial cells. 相似文献
45.
筛窦癌发病率低,就诊时病期晚,5年无瘤生存率为30%~50%。由于解剖部位的限制以及局部浸润,放射和手术均有一定难度。作者回顾性分析皇家Margret医院1976~1994年收治的29例浸润性筛窦癌根治性放射治疗的疗效和影响预后因素。男性24例,女性4例,中位年龄62岁,中位随访时间4年。常有鼻出血、鼻塞、疼痛及视力改变等。起病到确诊的平均时间为9个月。27例吸烟,10例从事伐木或镍的开采与提炼。 治疗前均经临床及影像学检查。仅3例局限于筛窦,余侵犯鼻腔、蝶窦、眼眶、上颌窦、额窦及脑内等。T1… 相似文献
46.
PC Morris JN Cawson GS Balasubramaniam 《Journal of Medical Imaging and Radiation Oncology》1999,43(1):12-15
Two cases of epidermal cyst of the breast, a rare benign condition, were detected during a 3-year period in a mammographic screening programme, from 57 954 screening examinations. It is not uncommon for epidermal cysts to be initially misdiagnosed. The mammographic, ultrasound and histological features are presented. It is recommended that these lesions be resected because they possibly have malignant potential. 相似文献
47.
48.
49.
50.
Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability 总被引:6,自引:0,他引:6
Gibson RN; Yeung E; Thompson JN; Carr DH; Hemingway AP; Bradpiece HA; Benjamin IS; Blumgart LH; Allison DJ 《Radiology》1986,160(1):43-47
In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction. 相似文献