全文获取类型
收费全文 | 5781篇 |
免费 | 503篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 252篇 |
妇产科学 | 87篇 |
基础医学 | 856篇 |
口腔科学 | 214篇 |
临床医学 | 693篇 |
内科学 | 913篇 |
皮肤病学 | 106篇 |
神经病学 | 465篇 |
特种医学 | 277篇 |
外科学 | 522篇 |
综合类 | 161篇 |
一般理论 | 6篇 |
预防医学 | 479篇 |
眼科学 | 364篇 |
药学 | 354篇 |
肿瘤学 | 514篇 |
出版年
2021年 | 69篇 |
2020年 | 42篇 |
2019年 | 84篇 |
2018年 | 94篇 |
2017年 | 71篇 |
2016年 | 62篇 |
2015年 | 102篇 |
2014年 | 117篇 |
2013年 | 204篇 |
2012年 | 250篇 |
2011年 | 243篇 |
2010年 | 165篇 |
2009年 | 143篇 |
2008年 | 230篇 |
2007年 | 231篇 |
2006年 | 244篇 |
2005年 | 202篇 |
2004年 | 239篇 |
2003年 | 186篇 |
2002年 | 189篇 |
2001年 | 203篇 |
2000年 | 166篇 |
1999年 | 167篇 |
1998年 | 89篇 |
1997年 | 91篇 |
1996年 | 74篇 |
1995年 | 72篇 |
1994年 | 66篇 |
1993年 | 69篇 |
1992年 | 122篇 |
1991年 | 125篇 |
1990年 | 116篇 |
1989年 | 130篇 |
1988年 | 117篇 |
1987年 | 119篇 |
1986年 | 86篇 |
1985年 | 107篇 |
1984年 | 75篇 |
1983年 | 72篇 |
1982年 | 47篇 |
1980年 | 53篇 |
1979年 | 93篇 |
1978年 | 72篇 |
1977年 | 47篇 |
1976年 | 61篇 |
1975年 | 70篇 |
1974年 | 57篇 |
1973年 | 53篇 |
1972年 | 63篇 |
1971年 | 44篇 |
排序方式: 共有6307条查询结果,搜索用时 31 毫秒
11.
Brain abscess in the 1980s 总被引:1,自引:0,他引:1
F E Donald J L Firth I M Holland D T Hope P Ispahani J A Punt 《British journal of neurosurgery》1990,4(4):265-271
Brain abscess was reviewed in 24 patients admitted to University Hospital, Nottingham over a period of 3 years. Chronic ear infection was the most common predisposing factor, but in 11 patients the focus of infection remained unknown. CT scanning, carried out in all patients, was negative in one patient with clinical signs of meningitis. Polymicrobial and anaerobic infections were common. Actinomyces species were isolated in mixed culture from seven patients; in five the abscess was located in the cerebellum. Therapy was most often a combination of surgical drainage and antimicrobial therapy with beta-lactam agents and metronidazole. Evidence suggests that cefotaxime may offer a suitable alternative to chloramphenicol and benzylpenicillin in the treatment of brain abscess. 相似文献
12.
A L Holland J B Greenhouse D Fromm C S Swindell 《Journal of speech and hearing research》1989,32(2):232-238
A consecutive sample of 50 language-impaired patients was evaluated prospectively during the first 3 to 4 months following unilateral left- or right-hemisphere stroke. A multiple logistic linear regression model was used to assess the relative importance of eight predictor variables on the likelihood of language recovery. Those found to be significantly associated with language recovery included age (favoring younger patients) and length of hospital stay (favoring shorter stays). Gender (favoring males), type of stroke (favoring hemorrhages), and side of lesion (favoring right) were only moderate correlates of recovery. Neither race nor history of previous stroke was a significant predictor of language recovery. Multivariate statistical analysis was useful in illuminating the joint relationship between clinical and demographic predictor variables and language recovery. 相似文献
13.
14.
Sheri A Keitz Gloria J Holland Evert H Melander Hayden B Bosworth Stephanie H Pincus 《Academic medicine》2003,78(9):910-917
PURPOSE: The U.S. Department of Veterans Affairs (VA) supports 8,700 resident positions nationally to enhance quality of care for veterans and to educate physicians. This study sought to establish a yearly quality indicator to identify and follow strengths and opportunities for improvement in VA clinical training programs. METHOD: In March 2001, the VA Learners' Perceptions Survey, a validated 57-item questionnaire, was mailed to 3,338 residents registered at 130 VA facilities. They were asked to rate their overall satisfaction with the VA clinical training experience and their satisfaction in four domains: faculty/preceptor, learning, working, and physical environments using a five-point Likert scale. Questionnaires were received from 1,775 residents (53.2%). A full analysis was conducted using 1,436 of these questionnaires, whose respondents were categorized in four training programs: medicine (n = 706), surgery (n = 291), subspecialty (n = 266), and psychiatry (n = 173). RESULTS: On a scale of 0 to 100, residents gave their clinical training experience an average score of 79. Eighty-four percent would have recommended VA training to peers, and 81% would have chosen VA training again. Overall, 87% were satisfied with their faculty/preceptors, 78% with the learning environment, and 67% with the working and physical environments. The survey was sensitive to differences in satisfaction among the trainee groups, with residents in internal medicine (IM) the least satisfied. CONCLUSION: The VA Learners' Perceptions Survey is the first validated survey to address comprehensive satisfaction issues in clinical training. The survey highlights strengths and opportunities for improvement in VA clinical training and is the first step toward improving education. 相似文献
15.
16.
Flexible endoscopes are complex medical instruments that are easily damaged. In order to maintain the flexible endoscope in optimum working condition, the user must have a thorough understanding of the structure and function of the instrument. This is the fourth in a series of articles presenting an in-depth look at the care and handling of the flexible endoscope. The first three articles discussed the air-water system, the suction channel system, and the mechanical system. This article will focus specifically on the endoscopic retrograde cholangiopancreatography elevator system. 相似文献
17.
18.
K E Dusenbery I H Alul E J Holland F M Khan S H Levitt 《International journal of radiation oncology, biology, physics》1992,24(2):315-320
Although postoperative beta irradiation for prevention of pterygium recurrence is widely used, its complication rate has not been widely appreciated. Thirty-six patients underwent pterygium excision followed by irradiation with 90Sr to between 1600 and 5300 cGy (median 2400) in two to four fractions over 7 to 27 days. A median of three fields were used in each treatment course (range two to 10). Most patients had undergone previous treatment for their pterygia, including surgery alone (25 patients), or both surgery and irradiation (5 patients). Overall, recurrences developed in 10 eyes (28%). Recurrence occurred in one eye after re-irradiation (20%), compared to 9 of 31 (29%) previously non-irradiated eyes (p greater than 0.1). There was no association with number of excisions and recurrences, although all but 6 patients had undergone more than one excision. Thirteen patients (36%) developed complications including: epithelial defect or corneal thinning (3), symblepharon (5), cataract (4) and corneal ulceration (1). Complications developed in 4 of the 5 (80%) re-irradiated eyes compared to 9 of 31 (29%) previously non-irradiated eyes (p less than 0.05). The power of the statistical analysis was limited by sample size, but no significant association was observed between the development of complications or recurrences and total dose, number of abutting fields, number of previous surgical excisions or patient age, even when re-irradiated patients were excluded. Recently described calibration uncertainties with the 90Sr applicator may explain in part these complications. Alternatively, technical factors such as the number of fields or volume treated may play a role. Excessive complications and recurrences with the use of postoperative beta irradiation in this series emphasize the danger of re-treatment and the need for alternative safe and effective therapies. 相似文献
19.
Gary N. Holland 《International ophthalmology》1994,18(3):163-165
The progressive outer retinal necrosis (PORN) syndrome is a recently described clinical variant of necrotizing herpetic retinopathy in patients with the acquired immunodeficiency syndrome (AIDS). It is caused by varicellazoster virus infection of the retina. Its course and clinical features distinguish it from the acute retinal necrosis syndrome and CMV retinopathy. Early disease is characterized by multifocal deep retinal opacification. Lesions rapidly coalesce and progress to total retinal necrosis over a short period of time. Despite aggressive therapy with intravenous antivirial drugs, prognosis is poor; disease progression and/or recurrence is common, and the majority of patients develop no light perception vision. Total retinal detachments are common. Prophylaxis against retinal detachment using laser retinopexy has not been useful in most cases. PORN syndrome is an uncommon, but devastating complication of AIDS. 相似文献
20.
Pathologic features of cytomegalovirus retinopathy after treatment with the antiviral agent ganciclovir 总被引:2,自引:0,他引:2
J S Pepose C Newman M C Bach T C Quinn R F Ambinder G N Holland P S Hodstrom H M Frey R Y Foos 《Ophthalmology》1987,94(4):414-424
Ganciclovir is a new antiviral compound (also called BW B759U, DHPG, BIOLF-62, and 2'NDG) that has been used for the treatment of cytomegalovirus (CMV) retinopathy in immunocompromised patients (bone marrow recipients or acquired immune deficiency syndrome [AIDS] victims). The authors studied the eyes of three AIDS patients with CMV retinopathy who died while receiving ganciclovir chemotherapy. Gross, microscopic, and ultrastructural studies of these cases showed varying degrees of retinal scarring and active CMV lesions at the margins of the scars. CMV antigens were localized in cells at all layers of retina at the border of the lesions and in isolated cells in a perivascular location within histologically normal appearing retina. These areas probably represent sites of recrudescence when the drug is discontinued. In situ hybridization using a cloned complementary DNA (cDNA) probe of human CMV corroborated the immunocytologic localization of the virus. Ultrastructural studies showed megalic syncytial cells containing mostly capsids exclusively in the cell nucleus. The cytoplasmic electron-dense membrane-bound bodies that have characterized untreated cases of CMV retinopathy were absent in the treated cases. An attempt to isolate CMV in tissue culture from the vitreous and retina of one of the cases yielded a negative result. Our results indicate that ganciclovir does not effectively eliminate CMV from the retina nor does it suppress expression of all viral genes. Ganciclovir appears to function by limiting viral DNA synthesis and subsequent packaging of viral DNA into infectious units, thereby acting as a virostatic chemotherapeutic agent. 相似文献