全文获取类型
收费全文 | 1602篇 |
免费 | 101篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 106篇 |
妇产科学 | 55篇 |
基础医学 | 132篇 |
口腔科学 | 14篇 |
临床医学 | 187篇 |
内科学 | 319篇 |
皮肤病学 | 32篇 |
神经病学 | 157篇 |
特种医学 | 71篇 |
外科学 | 315篇 |
综合类 | 22篇 |
预防医学 | 168篇 |
眼科学 | 13篇 |
药学 | 64篇 |
中国医学 | 1篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 11篇 |
2021年 | 14篇 |
2020年 | 16篇 |
2019年 | 22篇 |
2018年 | 22篇 |
2017年 | 20篇 |
2016年 | 16篇 |
2015年 | 27篇 |
2014年 | 33篇 |
2013年 | 44篇 |
2012年 | 59篇 |
2011年 | 47篇 |
2010年 | 39篇 |
2009年 | 40篇 |
2008年 | 57篇 |
2007年 | 77篇 |
2006年 | 62篇 |
2005年 | 67篇 |
2004年 | 64篇 |
2003年 | 74篇 |
2002年 | 62篇 |
2001年 | 36篇 |
2000年 | 40篇 |
1999年 | 31篇 |
1998年 | 33篇 |
1997年 | 30篇 |
1996年 | 33篇 |
1995年 | 29篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 38篇 |
1991年 | 44篇 |
1990年 | 38篇 |
1989年 | 44篇 |
1988年 | 35篇 |
1987年 | 24篇 |
1986年 | 20篇 |
1985年 | 26篇 |
1984年 | 21篇 |
1983年 | 20篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 15篇 |
1977年 | 20篇 |
1976年 | 8篇 |
1974年 | 8篇 |
1936年 | 8篇 |
1922年 | 8篇 |
排序方式: 共有1724条查询结果,搜索用时 15 毫秒
121.
Black BS Kasper J Brandt J Shore AD German P Burton L Gallo JJ Lyketsos C Rabins PV 《Alzheimer disease and associated disorders》2003,17(1):9-18
The Memory and Medical Care Study (MMCS) is a community-based, longitudinal study of elders at risk for dementia. This paper describes the study methods for identifying subjects with dementia or mild cognitive impairment (MCI) and the validation of these methods. The MMCS cohort was established by identifying subjects at risk for dementia in three previous studies of randomly ascertained samples. Neuropsychologic test score criteria were established to identify MMCS subjects with dementia or MCI. These criteria were validated using a fourth community-based sample of at-risk elders in which dementia was identified by a clinical adjudication panel. Of the 498 MMCS subjects, 70% had dementia and 27% had MCI by the MMCS criteria. In the validation sample, the MMCS dementia classification method was in agreement with the clinical adjudication panel for 81% of cases (kappa = 0.62, 95% confidence interval = 0.45-0.78). The methods used in the MMCS are efficient and reasonably valid for establishing a cohort of subjects to investigate how dementia is assessed, diagnosed, and treated in the community. 相似文献
122.
123.
Park JJ Del Pino A Orsay CP Nelson RL Pearl RK Cintron JR Abcarian H 《Diseases of the colon and rectum》1999,42(12):1575-1580
PURPOSE: A retrospective analysis of enteric stomas performed at Cook County Hospital was undertaken to evaluate stoma complications per stoma type and configuration and operating service. In addition, we attempted to identify factors predictive of increased enteric stoma complications. METHODS: From 1976 to 1995, data cards on 1,616 patients with stomas were compiled by Cook County Hospital enteric stomal therapists. Data card information included age, gender, weight, early and late stoma complications, emergency status, operating service, type and configuration of the stoma, and whether the patient was seen preoperatively by an enteric stomal therapist. Data were then analyzed using a logistic regression model to identify those variables that influenced the rate of complications. RESULTS: There were 553 (34 percent) patients with complications. Among the total complications, 448 (28 percent) occurred early (<1 month postoperative), and 105 (6 percent) occurred late (>1 month). The most common early complications were skin irritation (12 percent), pain associated with poor stoma location (7 percent), and partial necrosis (5 percent). The most common late complications were skin irritation (6 percent), prolapse (2 percent), and stenosis (2 percent). The enteric stoma with the most complications was the loop ileostomy (75 percent). The enteric stoma with the least complications was the end transverse colostomy (6 percent). The general surgery service had the most complications (47 percent), followed by gynecology (44 percent), surgical oncology (37 percent), colorectal (32 percent), pediatric surgery (29 percent), and trauma (25 percent). Age, operating service, enteric stoma type and configuration, and preoperative enteric stomal therapist marking were found to be variables that influenced stoma complications. CONCLUSIONS: Complications from enteric stoma construction are common. Preoperative enteric stoma site marking, especially in older patients, and avoiding the ileostomy, particularly in the loop configuration, can help minimize complications. 相似文献
124.
AM Pierides HA Ellis H Dellagrammatikas JE Scott AW Norman 《Archives of disease in childhood》1977,52(6):464-472
Three children with azotaemic renal osteodystrophy were treated with 1,25-dihydroxycholecalciferol (1,25(OH)2D3). All showed clinical, biochemical, and radiological improvement within 6 months of starting treatment. There were no complications. The dose of 1,25(OH)2D3 required was 0-5 microgram per day for 2 children aged 22 and 30 months, and 2 microgram per day for a 15-year-old boy. 2 of the patients were receiving phenobarbitone and phenytoin and in one of them prior treatment with dihydrotachysterol 0-5 mg daily and 6 microgram 1alpha-hydroxycholecalciferol (1alphaOHD3) daily had failed to induce improvement. In one patient, in whom serial iliac bone samples were available, 2 microgram 1,25(OH)2D3 resulted in histological improvement in previously severe osteomalacia. 1,25(OH)2D3 appears to be an effective and safe drug in the treatment of uraemic osteodystrophy. 相似文献
125.
Stephen E. Sallan Bruce M. Camitta Emil Frei Iii Lorrie Furman Pearl Leavitt Yvonne Bishop Norman Jaffe 《Pediatric blood & cancer》1977,3(3):281-287
Fifty-six untreated patients with childhood with acute lymphoblastic leukemia (ALL) were randomized to receive one of three remission induction regimens: vincristine and prednisone (VP), vincristine, prednisone and daunorubicin (VPD), or vincristine, prednisone and adriamycin (VPA). The complete remission rate was similar for all three groups. Although the anthracycline regimens caused somewhat more rapid leukemic cell reduction than the VP only group, this difference was not significant. Labeling index reduction between study days 1 and 5 was significantly greater (p < 0.001) with an anthracycline than for the VP group, but there was no difference between the two anthracyclines. Granulocytopenia during induction was significantly increased (p < 0.05) in both the VPD and VPA groups as compared with VP alone. A significantly higher rate of infectious morbidity (p < 0.01) was associated with the addition of either anthracycline, but to date no significant differences in remission duration or survival have been observed. The addition of anthracyclines to VP for remission induction in childhood ALL has theoretical advantages, but may be undesirable because of increased morbidity. 相似文献
126.
Neurological complications are common in recreational divers diagnosed with decompression illness (DCI). Prior reports suggest that hemoconcentration, with hematocrit values of 48 or greater, increase the risk for more severe and persistent neurological deficits in divers with DCI. Herein we describe our experience with neurological DCI and hematocrit values in a large series of consecutively treated divers. We performed a retrospective chart review of 200 consecutive recreational divers that received treatment for DCI. Standard statistical analyses were performed to determine if there were any significant relationships between diving-related or demographic parameters, neurological manifestations, and hematocrit. In 177 of the 200 divers (88.5%), at least one manifestation of neurological DCI (mild, moderate, or severe) was present. The median hematocrit value was 43, for both male and female divers, with a range of 30 to 61. Hematocrit values did not correlate with diver age or level of diving experience. In male divers, the hematocrit did not correlate with neurological symptoms, including the sub-group with values of 48 or greater. In contrast, female divers with hematocrit values of 48 or greater were significantly more likely to develop motor weakness (p=0.002, Fisher's exact test) and an increased number of severe sensory symptoms (p=0.001, Kendall's tau statistic). Neurological complications are common in recreational divers treated for DCI. Hematocrit values of 48 or higher were correlated with the presence of motor weakness and severity of sensory symptoms in female divers. The hematocrit did not correlate with neurological DCI in male divers. 相似文献
127.
128.
129.
M J Pearl 《Physical therapy》1990,70(2):105-107
The purpose of this study was to investigate the factors physical therapists use to make career choices. A questionnaire was sent to a random sample of 500 clinicians. The results of this study indicate that salary was the most important factor cited by clinicians for selecting their present position and for remaining in their present position, as well as the principal motivator that would induce them to consider leaving their present position. Unless salaries are raised in academe and in the traditional settings of acute care hospitals and rehabilitation centers, recruitment of clinicians in the future will be difficult. 相似文献
130.
Geometric analysis of commonly used prosthetic systems for proximal humeral replacement. 总被引:4,自引:0,他引:4
BACKGROUND: The anatomy of the proximal part of the humerus is extremely variable. The extent to which existing prosthetic systems and operative technique allow replication of this variability has not been established. METHODS: Four commonly used press-fit prosthetic systems for shoulder arthroplasty were compared with respect to their ability to match the superior-inferior and medial-lateral dimensions of the articular surface in twenty-one cadaveric humeri. The comparisons were accomplished with a computer optimization algorithm that searched a database of prosthetic geometry and selected the best match to the original anatomy. The algorithm assumed an osteotomy of the humeral head at an angle equivalent to the stem-head angle of the prosthesis, without violation of the greater tuberosity or the metaphyseal bone. The best match was defined as the prosthetic combination (stem and head) that least displaced the center of rotation and the articular surface, with both factors weighted equally. RESULTS: None of the prosthetic systems that were evaluated allowed identical replication of the articular surface. Rather, they displaced the center of rotation a mean of 14.7 millimeters (range, 3.3 to 31.4 millimeters) from its original position. To reach this minimized displacement, the prosthetic combinations that were selected by the algorithm also resulted in a mean diminution of the arc of the articular surface (a smaller head size) of 26 degrees (range, 11 to 41 degrees). In every instance, the selected prosthesis imposed a superior and lateral shift of the center of rotation that in effect shifted a smaller prosthetic humeral head up the slope of the humeral osteotomy. CONCLUSIONS: Press-fit prosthetic systems for shoulder arthroplasty that are commonly used necessitate marked alterations of the original anatomy. To the extent that a shoulder arthroplasty is an attempt to reproduce the normal anatomy, these findings have profound implications for operative technique and future prosthetic design. CLINICAL RELEVANCE: We believe that the superior position of the prosthetic head predicted by the present study plays a role in late complications of shoulder arthroplasty, such as rotator cuff tendinopathy, superior humeral migration, and loosening of the glenoid component. 相似文献