全文获取类型
收费全文 | 7796篇 |
免费 | 820篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 223篇 |
妇产科学 | 241篇 |
基础医学 | 1066篇 |
口腔科学 | 171篇 |
临床医学 | 1011篇 |
内科学 | 1352篇 |
皮肤病学 | 108篇 |
神经病学 | 569篇 |
特种医学 | 503篇 |
外科学 | 910篇 |
综合类 | 374篇 |
一般理论 | 2篇 |
预防医学 | 844篇 |
眼科学 | 184篇 |
药学 | 510篇 |
2篇 | |
中国医学 | 179篇 |
肿瘤学 | 367篇 |
出版年
2022年 | 56篇 |
2021年 | 128篇 |
2020年 | 81篇 |
2019年 | 76篇 |
2018年 | 114篇 |
2017年 | 89篇 |
2016年 | 87篇 |
2015年 | 108篇 |
2014年 | 156篇 |
2013年 | 245篇 |
2012年 | 311篇 |
2011年 | 341篇 |
2010年 | 224篇 |
2009年 | 227篇 |
2008年 | 262篇 |
2007年 | 323篇 |
2006年 | 337篇 |
2005年 | 316篇 |
2004年 | 272篇 |
2003年 | 280篇 |
2002年 | 269篇 |
2001年 | 275篇 |
2000年 | 250篇 |
1999年 | 266篇 |
1998年 | 173篇 |
1997年 | 157篇 |
1996年 | 149篇 |
1995年 | 166篇 |
1994年 | 110篇 |
1993年 | 134篇 |
1992年 | 181篇 |
1991年 | 171篇 |
1990年 | 155篇 |
1989年 | 182篇 |
1988年 | 176篇 |
1987年 | 170篇 |
1986年 | 136篇 |
1985年 | 142篇 |
1984年 | 106篇 |
1983年 | 90篇 |
1982年 | 61篇 |
1981年 | 62篇 |
1980年 | 71篇 |
1979年 | 62篇 |
1978年 | 80篇 |
1977年 | 59篇 |
1976年 | 55篇 |
1972年 | 55篇 |
1971年 | 45篇 |
1955年 | 43篇 |
排序方式: 共有8668条查询结果,搜索用时 15 毫秒
21.
P Williamson R D Allen S A Deane H Ekberg J M Grierson W J Hawthorne D C Mears K Tiver J M Little G J Stewart 《Transplantation》1990,50(4):576-579
The effect of total-lymphoid irradiation on survival of canine pancreas and kidney allografts was studied. TLI had a marked immunosuppressive effect as measured by in vitro immune responses and reduced circulating leukocytes. Despite the changes, median graft survival times for animals treated with 800 cGy (9 days) or 1800 cGy (9.5 days) were not significantly different from untreated control animals (7 days). The addition of low-dose antithymocyte globulin (10 mg/kg/day) on post-transplant days 0, 2, 4, 6, 8, and 10 had no measurable synergistic effect. Similarly, median segmental pancreas allograft survival times after 1700-2200 cGy of TLI treatment (16.5 days) were only marginally longer than those of untreated controls (9 days). The only animal to maintain a graft for greater than 200 days was matched to the donor in mixed lymphocyte culture (MLC). This animal was able to reject a third-party skin graft after 8 days while a graft from the original donor was still surviving after 21 days when the pancreas graft failed from a chronic-type rejection. These results indicate that TLI alone or in combination with ATG will not be predictably effective as a method of prolonging allograft survival. The role of matching major histocompatibility complex antigens in TLI treatment requires clarification. 相似文献
22.
23.
Harold A. Williamson Jr. MD MSPH L. Gary Hart PhD Michael J. Pirani Roger A. Rosenblatt MD MPH 《The Journal of rural health》1994,10(1):16-25
Surgical services are an important part of modern health care, but providing them to isolated rural citizens is especially difficult. Public policy initiatives could influence the supply, training, and distribution of surgeons, much as they have for rural primary care providers. However, so little is known about the proper distribution of surgeons, their contribution to rural health care, and the safety of rural surgery that policy cannot be shaped with confidence. This study examined the volume and complexity of inpatient surgery in rural Washington state as a first step toward a better understanding of the current status of rural surgical services. Information about rural surgical providers was obtained through telephone interviews with administrators at Washington's 42 rural hospitals. The Washington State Department of Health's Commission Hospital Abstract Recording System (CHARS) data provided a count of the annual surgical admissions at rural hospitals. Diagnosis-related group (DRG) weights were used to measure complexity of rural surgical cases. Surgical volume varied greatly among hospitals, even among those with a similar mix of surgical providers. Many hospitals provided a limited set of basic surgical services, while some performed more complex procedures. None of these rural hospitals could be considered high volume when compared to volumes at Seattle hospitals or to research reference criteria that have assessed volume-outcome relationships for surgical procedures. Several hospitals had very low volumes for some complex procedures, raising a question about the safety of performing them. The leaders of small rural hospitals must recognize not only the fiscal and service benefits of surgical services--and these are considerable--but also the potentially adverse effect of low surgical volume on patient outcomes. Policies that encourage the proper training and distribution of surgeons, the retention of basic rural surgical services, and the rational regionalization of complex surgery are likely to enhance the convenience and safety of surgery for rural citizens. 相似文献
24.
One possible complication in infant pneumonectomy is mediastinal shift that can fatally kink or compress airways and vessels. Rigid prostheses have been used to prevent these problems; however, they cannot be adjusted as the child grows. We report a case of expandable prosthesis implantation in a 24-day-old infant. During the 18 months postimplantation, the prosthesis was periodically injected with a saline/contrast solution to maintain the mediastinum in a midline position as the child grew. At 24-month follow-up the prosthesis was still in place, and midline position of the mediastinum maintained. 相似文献
25.
Ketai LH; Williamson MR; Telepak RJ; Levy H; Koster FT; Nolte KB; Allen SE 《Radiology》1994,191(3):665
26.
When the distance between linked loci is expressed in terms of the correlation between the identity-by-descent (idb) values of the loci, then a path model may be used to order loci with data on sib-pairs and their parents. The relationship between the recombination fraction and the correlation coefficient is developed and a method for fitting a covariance matrix predicted by a specific ordering of loci to an observed covariance matrix is proposed. © 1993 Wiley-Liss. Inc. 相似文献
27.
BACKGROUND AND AIM: Peptic ulcer disease is believed to be less common and less severe as a result of modern medical treatment. We therefore examined changes in the admission rates for patients with duodenal ulcer and gastric ulcer, both emergency (for haemorrhage, perforation or severe pain) and for elective surgery, before and since the introduction of the new advances in therapy. These admission indices reflect disease prevalence and severity. PATIENTS AND METHODS: We identified admission rates during 1972--2000 within the Trent Regional Health Authority, UK (population 4.7 million), from computerised patient information using diagnostic search codes ICD8-10 and expressed as rates per million resident population. Drug expenditure details were obtained from the Department of Health. RESULTS: Emergency admission rates as a whole changed little, a decline in the young being offset by an increase in the elderly. Haemorrhage was the most common reason (approximately 115 per million for duodenal ulcer and 87 for gastric ulcer) throughout [compared with perforation (80 and 21) and pain (90 and 68)]. In contrast, elective surgery has almost disappeared; this reduction began before the introduction of modern treatment. CONCLUSION: Emergency admission rates for duodenal and gastric ulcer for complications or severe pain have fluctuated over the last three decades but with little overall change. In contrast, elective surgery has declined dramatically, as a result of advances in treatment but also from changes in the natural history. 相似文献
28.
M LeFevre H A Williamson M Hector 《The Journal of family practice》1989,28(6):691-5; discussion 695-6
A study was undertaken to evaluate Coopland's obstetric risk index in a rural primary care setting. Information on 635 pregnant women cared for in a rural practice was collected prospectively. Adverse outcome was defined as perinatal death, birthweight less than 2500 g, 5-minute Apgar score less than 7, or newborn transferred to a level 2 or level 3 nursery. Forty-seven pregnancies (8.3%) had an adverse outcome. There was a clear relationship between risk score and probability of adverse outcome. Good sensitivity could be achieved only at the expense of a very high false-positive rate, however. The index can be used to identify a subgroup of women at relatively high risk for adverse outcome, but the majority of adverse outcomes will occur in women identified as low risk. The risk-scoring system in this population was no more effective than a policy that would refer all women with standard obstetric risk factors. 相似文献
29.
Mathieu Beaulieu David Williamson Gilbert Pichette Jean Lachaine 《Infection control and hospital epidemiology》2007,28(11):1305-1307
Our study was conducted to determine whether use of gastric acid-suppressive agents increased the risk of Clostridium difficile-associated disease (CDAD) in a medical intensive care unit of one of the first hospitals to be threatened by the current CDAD epidemic in Quebec, Canada. Our findings suggest that efforts to determine risk factors for CDAD should focus on other areas, such as older age and antibiotic use. 相似文献
30.
Miriam Stewart Linda Reutter Edward Makwarimba Irving Rootman Deanna Williamson Kim Raine Doug Wilson Janet Fast Rhonda Love Sharon McFall Deana Shorten Nicole Letourneau Karen Hayward Jeff Masuda William Rutakumwa 《Revue canadienne de recherche en sciences infirmières》2005,37(3):104-131
Poverty influences health status, life expectancy, health behaviours, and use of health services. This study examined factors influencing the use of health-related services by people living in poverty. In the first phase, 199 impoverished users of health-related services in 2 large Canadian cities were interviewed by their peers. In the second phase, group interviews with people living in poverty (n = 52) were conducted. Data were analyzed using thematic content analysis. Diverse health-related services were used to meet basic and health needs, to maintain human contact, and to cope with life's challenges. Use of services depended on proximity, affordability, convenience, information, and providers' attitudes and behaviours. Use was impeded by inequities based on income status. To promote the health of people living in poverty, nurses and other health professionals can enhance the accessibility and quality of services, improve their interactions with people living in poverty, provide information about available programs, offer coordinated community-based services, collaborate with other sectors, and advocate for more equitable services and policies. 相似文献