全文获取类型
收费全文 | 498篇 |
免费 | 35篇 |
国内免费 | 145篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 13篇 |
妇产科学 | 15篇 |
基础医学 | 34篇 |
口腔科学 | 21篇 |
临床医学 | 130篇 |
内科学 | 75篇 |
皮肤病学 | 4篇 |
神经病学 | 60篇 |
特种医学 | 13篇 |
外科学 | 41篇 |
综合类 | 62篇 |
预防医学 | 23篇 |
眼科学 | 7篇 |
药学 | 149篇 |
肿瘤学 | 23篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 12篇 |
2019年 | 14篇 |
2018年 | 19篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 20篇 |
2012年 | 28篇 |
2011年 | 21篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 113篇 |
2006年 | 19篇 |
2005年 | 36篇 |
2004年 | 20篇 |
2003年 | 12篇 |
2002年 | 21篇 |
2001年 | 18篇 |
2000年 | 27篇 |
1999年 | 13篇 |
1998年 | 14篇 |
1997年 | 20篇 |
1996年 | 19篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 7篇 |
1991年 | 13篇 |
1990年 | 22篇 |
1989年 | 17篇 |
1988年 | 18篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1979年 | 3篇 |
排序方式: 共有678条查询结果,搜索用时 15 毫秒
1.
1-乙基-6-氟-1,4-二氢-4-氧代-7-(4-芳酰硫代氨甲酰基-1-哌嗪基)-3-喹啉羧酸的合成及抗菌作用 总被引:4,自引:1,他引:3
Thirteen new 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-aroyl-thiocarbamoyl- 1 piperazinyl)-3-quinoline carboxylic acids were prepared, Their structures were characterized by elemental analysis, IR, HNMR and MS spectra.Preliminary pharmacological tests indicated that some of compounds Ia~m possess strong inhibiting activity against Escherichia coli, Bacillus subtilis and Proteus at concentration of 100 μg/ml. 相似文献
2.
3.
4.
大狼毒三萜类化学成分的研究 总被引:3,自引:0,他引:3
自大戟科(Euphorbiaceae)植物大狼毒(Euphorbia nematocypha Hand—Mazz)根的乙醇提取物的苯溶解部分,经20%AgNO3硅胶层析,分离得到七个三萜类成分。根据光谱(IR,EIMS,1H—NMR和13C—NMR)和化学方法,确定其中一个化合物为新化合物,命名为大狼毒醇(nematocyphol,Ⅳa),其它化合物为已知物:印度荆芥醇乙酸酯(nepehinol acetate Ⅰ),日尔曼醇乙酸酯(germanicol acetate Ⅱ),大戟醇(euphol,Ⅲ),蒲公英醇(taraxasterol,Ⅴa),24-亚甲基环阿尔廷醇(24-methylenecycloartanol,Ⅴa)和印度荆芥醇(nepehinol,Ⅶa)。这些化合物均为首次从大狼毒中得到。 相似文献
5.
Theresa M Y Lee Siow Ann Chong Yiong Huat Chan Gangaharan Sathyadevan 《Revue canadienne de psychiatrie》2004,49(12):838-842
OBJECTIVES: The impact of command hallucinations on patients and the determinants of patients' compliance with them are still poorly understood. The extant literature is also divided on their association with violence. This study aimed to establish the prevalence of command hallucinations and to identify the factors that affect compliance with the commands, together with patients' coping methods. METHODS: We recruited 50 consecutive male and 50 consecutive female schizophrenia inpatients who reported hearing voices in the 6 months prior to admission. We interviewed these patients, using a semistructured questionnaire. We collected information on the contents of their auditory hallucinations and their coping methods. RESULTS: Of the patients, 53 (53%) reported command hallucinations. Of these 53 patients, 58% were women and 48% were men; 62% reported complying with the commands. They were also more likely to comply with nonviolent commands. A history of self-harm predicted compliance. Those patients who did not comply with the commands adopted various methods of coping, of which praying was the most common. CONCLUSION: Command hallucinations are common in patients with schizophrenia. Patients with a history of self-harm need closer monitoring because they may be more likely to comply with these hallucinations. Assessment should also include the patient's own coping strategies, which can be incorporated into the treatment. 相似文献
6.
PURPOSE: To determine if rigid gas permeable (RGP) or soft contact lenses can be successfully worn after photorefractive keratectomy (PRK) to correct residual refractive errors. METHODS: Patients with residual stable ametropia after PRK were fit with RGP or soft lenses. Manifest refraction, corneal topography, and keratometry were performed, and post-PRK corneal haze was graded during the study visits. Contact lens fit characteristics and comfort were assessed. Lens centration, visual quality, and ocular surface status were graded, and visual acuity with contact lenses was charted. RESULTS: Eighteen patients were recruited for RGP lens fitting. The mean refractive error post-PRK was +0.80 D +/- 2.03 (range: -3.50 to+3.00 D). The mean contact lens power was -3.90 D +/- 2.03 (range: 0 to -7.00 D), and the mean contact lens base curve was 7.88 mm +/-0.16. A significant positive tear film at the site of the central ablation was noted, contributing to excessive minus lens power in all cases. Despite mild to moderate lens instability and de-centration, 14 patients reported excellent visual quality with the lenses, and pre-PRK best-corrected acuity was achieved in all patients. Twenty-five percent (4 of 16) of the patients were able to wear the lenses all day. Eleven patients were recruited for soft contact lens fitting-five from the RGP trial. The mean refractive error post-PRK was -0.64 D +/- 2.01 (range: -3.50 to +1.75D). The mean contact lens power was -0.60 D +/- 2.07 (range: -3.75 to +2.5 D), and the mean contact lens base curve was 8.33 mm +/- 0.42. Eight patients were corrected with lenses to their pre-PRK best-corrected acuity, and nine patients reported excellent visual quality with the lenses. All the patients had excellent lens centration. Thirty-six percent (four of 11) of patients were wearing the lenses all day. CONCLUSIONS: Fitting RGP lenses after PRK results in good visual acuity but may be associated with mild to moderate lens instability and decentration. Soft contact lens fitting also results in good visual acuity. Soft lenses were better tolerated by the subjects in our study because of improved lens centration and stability. 相似文献
7.
Siow WY Yip SK Ng LG Tan PH Cheng WS Foo KT 《Journal of the Royal College of Surgeons of Edinburgh》2000,45(5):291-295
In developed countries, there has been increased incidental detection of renal cell carcinoma (RCC). The incidence, pathological stage and survival of incidentally detected carcinoma in a developing country in Asia where, from 1990 to 1998, 165 renal cell carcinomas were identified. The clinical presentation, diagnostic-imaging modality employed, pathological staging and patient survival was reviewed. Incidental renal cancers included those that were diagnosed through health screening or detected incidentally through imaging studies for other conditions. The survival between these incidentally detected lesions and their symptomatic counterparts (suspected group) was compared. Sixty-four patients (39%) had their tumours detected incidentally, including 39 who were entirely asymptomatic and 25 who presented with non-specific symptoms, not initially suggestive of RCC. For the entire group, computed tomography provided the definitive diagnosis in 81% of cases. The incidental detection group had significantly smaller size of tumour (5.9 cm c.f. 7.6 cm), lower stage and lower histological grading. In particular, 78% of patients with incidental RCC had stage I or II diseases (TNM stage classification), compared with 57% of patients with suspected tumour (p < 0.05; Chi-square test). The disease free survival was significantly better for those with incidental detection (86% c.f. 66% at last follow up; p < 0.05; log-rank test) over a mean follow up period of 33 months (range 1-91). Regression analysis showed that stage of disease was the only independent variable predictive of clinical outcome. In conclusion, that significant numbers of RCC were detected incidentally. These tumours were of a lower clinical pathological stage and had a better prognosis. 相似文献
8.
目的 探讨喉神经肌电位综合指标对声带麻痹预后的估价作用。方法 检测91例甲状腺手术单侧声带麻痹患者的喉神经电图及肌电位,按病程分成4组;分析各组恢复与未恢复声带运动的患者喉神经肌电位特征,以“95%可信区间”计算神经肌电位预后评估标准。结果 病程2个月内组最大诱发电位幅度明显低于2个月以上的其他各组,差异具有显著性意义(P<0.05),而2-4个月与4-6个月组的组间差异无显著性(P>0.05),故将病程2-6个月计为一组。2个月内组自然恢复与未恢复患者分别为2、11例,以引出诱发电位且无错向再生电位作为预后良好判断指标,准确率为92%(12/13)。2-6个月组恢复与未恢复患者各为11、48例,恢复者最大诱发电位幅度明显大于未恢复者,差异有显著性意义(P<0.01)。以引出诱发电位且电位幅度大于26.4%作为预后良好的判断标准,准确率90%(53/59);结合无错向再生电位综合判断预后,准确率为93%(55/59)。6个月以上组19例无论神经肌电位检查结果如何,声带运动均无恢复。结论 将神经肌电位进行综合分析,分别判断不同病程的声带麻痹的预后,可提高预后判断的准确率。 相似文献
9.
10.