全文获取类型
收费全文 | 1167篇 |
免费 | 94篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 82篇 |
妇产科学 | 26篇 |
基础医学 | 111篇 |
口腔科学 | 19篇 |
临床医学 | 85篇 |
内科学 | 204篇 |
皮肤病学 | 6篇 |
神经病学 | 189篇 |
特种医学 | 31篇 |
外科学 | 204篇 |
综合类 | 23篇 |
一般理论 | 6篇 |
预防医学 | 147篇 |
眼科学 | 14篇 |
药学 | 55篇 |
肿瘤学 | 58篇 |
出版年
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 9篇 |
2015年 | 13篇 |
2014年 | 23篇 |
2013年 | 35篇 |
2012年 | 51篇 |
2011年 | 46篇 |
2010年 | 16篇 |
2009年 | 25篇 |
2008年 | 42篇 |
2007年 | 50篇 |
2006年 | 54篇 |
2005年 | 31篇 |
2004年 | 48篇 |
2003年 | 53篇 |
2002年 | 27篇 |
2001年 | 34篇 |
2000年 | 37篇 |
1999年 | 42篇 |
1998年 | 12篇 |
1997年 | 18篇 |
1996年 | 18篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1992年 | 42篇 |
1991年 | 32篇 |
1990年 | 22篇 |
1989年 | 26篇 |
1988年 | 35篇 |
1987年 | 36篇 |
1986年 | 23篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 21篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 18篇 |
1978年 | 27篇 |
1977年 | 17篇 |
1976年 | 11篇 |
1975年 | 16篇 |
1974年 | 11篇 |
1973年 | 17篇 |
1971年 | 9篇 |
1970年 | 8篇 |
1967年 | 9篇 |
排序方式: 共有1262条查询结果,搜索用时 15 毫秒
11.
Joffe C 《Family planning perspectives》1999,31(1):35-38
Medical abortion has the potential to expand US women's access to pregnancy termination, especially in areas that lack surgical providers. Exploratory interviews conducted in 1996 with 25 long-term providers of surgical abortion offered a "snapshot" of an early moment in the adoption of medical abortion techniques in the US. 20 of these providers already had experience with methotrexate and/or mifepristone. Overall, the interviews suggested that innovation in the area of abortifacient agents is likely to proceed slowly and cautiously, despite their high degrees of efficacy and safety. Although providers were committed to providing women a full range of abortion alternatives, they indicated that medical abortion demands substantial modifications in office routines. For example, counseling medical abortion patients requires twice the time as talking to a surgical abortion patient. The need for ultrasound to size very early pregnancies and ensure the abortion has been completed restricts provision to physicians with access to this technology. The requirement of ultrasound and multiple office visits makes medical abortion more costly than the surgical approach. Continued expansion in the ranks of medical abortion providers is dependent upon factors such as the ultimate status of mifepristone in terms of US Food and Drug Administration approval and appropriate manufacturing and distribution arrangements, clarification of whether misoprostol insertion must be performed in a physician's office, the willingness of managed care insurance plans to cover this alternative, and the response of US anti-abortion organizations. 相似文献
12.
The current approach to mood disorders is that bipolar disorder, comprising both mania and depression, is a discreet illness distinct from unipolar depression. This formulation has profoundly influenced the approach to understanding the biology and etiology of these disorders, as well as the manner in which the various phases of bipolar disorder are treated. Our new model suggests that bipolar disorder comprises two distinct illnesses, mania and depression, and that bipolar depression is no different from unipolar depression. Studies of clinical syndromes, course of illness, family history and genetics, biological factors, and treatment response data directly or indirectly support this new model. 相似文献
13.
14.
We have investigated the role of coagulation and fibrinolysis during the metastatic lung colonization of F3II mouse mammary carcinoma cells. The selective synthetic urokinase inhibitor B623 significantly enhanced lung colonization and blocked the antimetastatic effect of heparin when administered i.p. during the first stages of metastasis formation. In B623-treated mice the overall activity of the fibrinolytic system was reduced and circulating urokinase was specifically inhibited by this agent. In vitro studies demonstrated that B623 induces the aggregation of F3II cells in the presence of mouse plasma and facilitates the entrapment of tumor cells in a fibrin gel matrix. Our data suggest that imbalances of fibrin deposition and removal may dramatically influence metastatic lung colonization. 相似文献
15.
An outpatient regimen of interferon-alpha (IFN-alpha), interleukin-2 (IL-2) and 5-fluorouracil (5-FU) was previously reported to have significant activity (response rate 48.6%) in patients with advanced renal cell carcinoma (RCC). The patient group reported were generally of good performance status (PS), had undergone previous nephrectomy and would be considered of good prognosis with respect to response and survival after treatment with IL-2. The characteristics of patients with RCC referred to specialist units in the UK differ from that patient group in that many patients present with metastatic disease, are of poor PS and are considered unfit for nephrectomy. We tested the three drug regimen in a representative patient group of 55 patients who had: median PS of 1 (range 0-2); median time from diagnosis to treatment of 2.7 months (0.2-113); and median number of sites of disease 3 (1-5). 22/55 had not had prior nephrectomy and 31 were considered of poor risk, 15 moderate risk and only 9 of good risk. Treatment consisted of an 8 week cycle of IFN-alpha 6 MU/m2 day 1 weeks 1 and 4 and thrice weekly weeks 2-3 and 9 MU/m2 thrice weekly, weeks 5-8. IL-2 20 MU/m2 days 3-5, weeks 1 and 4 and 5 MU/m2 thrice weekly weeks 2-3. 5-FU 750 mg/m2 day 1 of weeks 5-8. There were no complete responses (CR), 9 (17%) partial responses (PR) and 13 patients (24%) had stable disease. Sixteen patients withdrew early from treatment and were not evaluable for response. Amongst 25 evaluable patients who had undergone nephrectomy the response rate was 32% (95% CI: 14-50%). Only 1 response was seen in patients who had not undergone nephrectomy. Survival was predicted by PS, nephrectomy, number of sites of metastasis and risk group. Most patients experienced significant toxicity of grade I/II but few grade III/IV toxicities were seen as compared to intravenous IL-2 regimens. These data are part of a large data set that has been submitted for publication in The British Journal of Urology. The regimen has been shown to have activity but this is seen predominantly in patients of good PS, with prior nephrectomy and limited sites of disease. Patients of poor risk are likely to experience significant toxicity without benefit and should be offered alternative palliative therapies. 相似文献
16.
In the present study, we evaluated the relationship between 1. the volume and rate of dialysis outflow and subsequent inflow, 2. the patient's impression of the location of the catheter tip and 3. the stability of the catheter tip location. Thirteen patients were studied on 2 random occasions (periods 1 and 2). Inflow (L/min) was significantly faster than outflow (p less than 0.05). No catheter tips were located in the far upper part of the abdomen. Outflow with the catheter tip located in the middle part of the abdomen was significantly lower than with the tip located in the inferior quadrants (p less than 0.02). Two patients were able to feel the catheter tip at Period 1, and 4 at Period 2, but only 1 patient was able to state the exact location identical to fluoroscopy. Ninety-two percent of the fluoroscopic evaluations showed catheter tips located in the same anatomical regions in upright as well as supine positions. If vertical "neighbour" anatomical regions were included in the evaluation of the catheter tip migrations, all catheter tips were located at the same or the vertical "neighbour" region in the 2 study periods. 相似文献
17.
18.
FJ O'Callaghan AC Clarke H Joffe B Keeton R Martin A Salmon RD Thomas JP Osborne 《Archives of disease in childhood》1998,78(2):159-162
This report highlights the association between tuberous sclerosis and Wolff-Parkinson-White syndrome. Ten patients with concurrent diagnoses of Wolff-Parkinson-White syndrome and tuberous sclerosis were identified. Wolff-Parkinson-White syndrome presented early in life, nine cases being diagnosed in the first year. Eight of the 10 cases were male. In eight cases, the syndrome was associated with supraventricular tachycardias, and in nine with cardiac rhabdomyomata. One child died from cardiac failure secondary to obstruction of the left ventricular outflow tract by a rhabdomyoma. Five of nine survivors showed resolution of Wolff-Parkinson-White syndrome on follow up. The accessory pathway was localised in nine patients from surface electrocardiograms: six children had left sided pathways and three had right sided pathways. 相似文献
19.
Nutrigenetics and nutrigenomics, as well as diet and exercise, play an important role in the development and treatment of obesity and its comorbidities. If an individual’s susceptibility to becoming obese and their responsiveness to weight loss interventions are to be understood, then it needs to be addressed at a molecular and metabolic level, including genetic interaction. This review proposes a three-pillar approach to more fully comprehend the complexity of diet-gene interactions in obesity. Peroxisomal proliferating-activated receptor gamma (PPARG) and mitochondrial uncoupling protein-1 (UCP-1) are explored in detail. Illustrating how an understanding of nutritional biochemistry, nutrigenomics, and nutrigenetics may be the key to understanding differences observed in the obese phenotype that vary both within and across populations. 相似文献
20.
David L. Murphy Thomas D. Rea Andrew M. McCoy Michael R. Sayre Carol E. Fahrenbruch Lihua Yin Benjamin A. Tonelli Aaron M. Joffe Steven H. Mitchell 《The American journal of emergency medicine》2019,37(5):937-941