全文获取类型
收费全文 | 467篇 |
免费 | 78篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 11篇 |
妇产科学 | 8篇 |
基础医学 | 73篇 |
口腔科学 | 55篇 |
临床医学 | 30篇 |
内科学 | 63篇 |
皮肤病学 | 15篇 |
神经病学 | 35篇 |
特种医学 | 24篇 |
外科学 | 114篇 |
预防医学 | 20篇 |
眼科学 | 7篇 |
药学 | 15篇 |
中国医学 | 1篇 |
肿瘤学 | 70篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 30篇 |
2020年 | 13篇 |
2019年 | 26篇 |
2018年 | 28篇 |
2017年 | 27篇 |
2016年 | 28篇 |
2015年 | 27篇 |
2014年 | 28篇 |
2013年 | 51篇 |
2012年 | 39篇 |
2011年 | 50篇 |
2010年 | 14篇 |
2009年 | 10篇 |
2008年 | 21篇 |
2007年 | 21篇 |
2006年 | 15篇 |
2005年 | 13篇 |
2004年 | 19篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有547条查询结果,搜索用时 122 毫秒
31.
Fukushima T Berumen M Vargas N Zadeh N Hon EH 《American journal of obstetrics and gynecology》2002,186(6):1207-13; discussion 1213-5
OBJECTIVE: Our purpose was to assess the effects of the adjunctive use of cardiovascular dynamics monitoring in the ambulatory management of 199 pregnant patients with severe hypertension. STUDY DESIGN: A prospective, observational study was performed. Determinants of mean arterial pressure were computed by using the Hon monitor. Indicators of arterial compliance and effective blood volume were developed. All patients were monitored in the outpatient clinic; additionally, 19 patients self-tested at home. No rigid medication protocol was followed, but furosemide was used in most cases when cardiovascular dynamics monitoring patterns were consistent with volume loading. Otherwise, vasodilators were prescribed. The t test for independent samples was used to compare the home-monitored subgroup with the outpatient-only group. RESULTS: Pregnancy was prolonged by 74 +/- 63.9 days (mean +/- SD). Mean gestation was 37.6 +/- 2.9 weeks, and mean birth weight was 2882.4 +/- 837 g. The primary cesarean delivery rate was 23.7%, but only 15 (7.5%) cesarean deliveries were performed because of failed therapy. The 19 home-monitored patients gained 108 +/- 75 days (83.1 +/- 42.2 days beyond 20 weeks). CONCLUSION: Adjunctive cardiovascular dynamics monitoring may have a role in the evaluation and management of hypertension during pregnancy. 相似文献
32.
BACKGROUND: Fine-needle aspiration biopsy (FNAB) is used as the first-line diagnostic test for lesions that require morphologic assessment in the authors' breast cancer screening program. A positive cytologic diagnosis is an indication to proceed to definitive surgery. Core biopsy is used if FNAB is not diagnostic. In the context of increased use of core biopsy at other centers, the authors reviewed their experience with the cytologic assessment of highly suspicious microcalcifications. METHODS: Between January 1996 and June 2000, the dominant radiologic abnormality was classified prospectively as high-grade microcalcifications in 182 lesions. Data were recorded on patient demographics, radiologic features, and the findings of FNAB and core biopsy, if performed. The results of the screening assessment were then compared with the final histologic findings. RESULTS: Overall, 15.6% of all radiologically high-grade lesions were microcalcifications. The mean patient age was 58.76 years. The lesions had a mean size of 38.49 mm (range, 5-200 mm), and 92.31% of high-grade microcalcifications proved to be malignant. Among the cases evaluated by FNAB, a positive cytologic diagnosis of malignancy was made in 70.93% of lesions, without any false-positive diagnoses and obviating the need for diagnostic core biopsy. FNAB had a sensitivity of 77.22% and a positive predictive value (PPV) of 100%. When core biopsy was performed due to the absence of a positive cytologic diagnosis, it averted the need for open biopsy in 76% of lesions. CONCLUSIONS: Where there is access to skilled cytopathologists, FNAB can provide a highly accurate, rapid, and cost-effective means of triage of patients who would benefit most from the more expensive core biopsy. 相似文献
33.
Angiogenesis involves a highly regulated and coordinated interaction of multiple angiogenic factors and is critical for both embryonal development and physiological vessel formation in adults. Angiogenesis is also proven to significantly contribute to the progression of various disease processes. Pathological angiogenesis is thought to recapitulate physiological angiogenesis, however the precise molecular mechanisms are not understood. Various angiogenic genes and gene products have been isolated, purified, and cloned from both neoplastic and normal tissues that contribute to the angiogenic process. In this review we summarize the role of the main angiogenic factors in both normal embryonal vascularization of the embryonal nervous system together with the main brain tumors seen in adults. 相似文献
34.
35.
36.
37.
The effect of previous malnutrition on the metabolic response to surgical hysterectomy was investigated in adult female rats. Malnutrition was achieved by feeding a 20 g protein/kg diet and restricting food intake to 50% of normal. This dietary regimen was maintained for 3 weeks before surgery and for 4 d after surgery. Unoperated control rats were pair-fed with the hysterectomized rats after surgery. Energy balance was measured by the comparative carcass technique and, in a second experiment, urinary N excretion was measured. Surgery caused energy expenditure to increase by 37% in ad libitum-fed rats but in malnourished rats it increased by only 22%. Urinary N excretion rose immediately after surgery. In the ad libitum-fed rats it was on average 85% greater in hysterectomized rats than controls for the first 3 d after surgery, whereas in the restricted rats it was 74% greater on the first day and not significantly elevated thereafter. Thus, malnutrition attenuated the metabolic response to surgery but did not abolish it completely. 相似文献
38.
Association of Pre‐ESRD Serum Calcium With Post‐ESRD Mortality Among Incident ESRD Patients: A Cohort Study 下载免费PDF全文
39.
Rachelle Bross Nazanin Noori Csaba P. Kovesdy Sameer B. Murali Debbie Benner Gladys Block Joel D. Kopple Kamyar Kalantar‐Zadeh 《Seminars in dialysis》2010,23(4):359-364
Examining the quality and quantity of food intake by appropriate methods is critical in the management of patients with chronic kidney disease (CKD). The four commonly used dietary assessment methods in CKD patients include short‐term dietary recalls, several days of food records with or without dietary interviews, urea kinetic based estimates such as protein nitrogen appearance calculation, and food histories including food screeners and food frequency questionnaires (FFQ). There are a number of strengths and limitations of these dietary assessment methods. Accordingly, none of the four methods is suitable in and of itself to give sufficiently accurate dietary information for all purposes. Food frequency questionnaires, which is the preferred method for epidemiological studies, should be used for dietary comparisons of patients within a given population rather than individual assessment. Food histories including FFQ and dietary recalls may underestimate important nutrients, especially in CKD patients. Given the large and increasing number of dialysis patients and work responsibilities of renal dietitians, routine analysis of dietary records and recalls is becoming less feasible. Ongoing and future studies will ascertain additional strengths and limitations of dietary assessment methods in CKD populations including the assessment of food intake during an actual hemodialysis treatment. 相似文献
40.