全文获取类型
收费全文 | 9584篇 |
免费 | 781篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 206篇 |
儿科学 | 328篇 |
妇产科学 | 222篇 |
基础医学 | 1195篇 |
口腔科学 | 210篇 |
临床医学 | 850篇 |
内科学 | 1673篇 |
皮肤病学 | 219篇 |
神经病学 | 1051篇 |
特种医学 | 543篇 |
外科学 | 1298篇 |
综合类 | 211篇 |
一般理论 | 7篇 |
预防医学 | 912篇 |
眼科学 | 478篇 |
药学 | 518篇 |
中国医学 | 2篇 |
肿瘤学 | 501篇 |
出版年
2021年 | 150篇 |
2019年 | 105篇 |
2018年 | 115篇 |
2017年 | 87篇 |
2016年 | 107篇 |
2015年 | 123篇 |
2014年 | 209篇 |
2013年 | 295篇 |
2012年 | 398篇 |
2011年 | 407篇 |
2010年 | 263篇 |
2009年 | 266篇 |
2008年 | 394篇 |
2007年 | 400篇 |
2006年 | 382篇 |
2005年 | 416篇 |
2004年 | 422篇 |
2003年 | 373篇 |
2002年 | 343篇 |
2001年 | 318篇 |
2000年 | 298篇 |
1999年 | 318篇 |
1998年 | 105篇 |
1997年 | 136篇 |
1996年 | 110篇 |
1995年 | 113篇 |
1994年 | 106篇 |
1993年 | 98篇 |
1992年 | 201篇 |
1991年 | 199篇 |
1990年 | 211篇 |
1989年 | 187篇 |
1988年 | 174篇 |
1987年 | 198篇 |
1986年 | 178篇 |
1985年 | 211篇 |
1984年 | 126篇 |
1983年 | 100篇 |
1982年 | 83篇 |
1981年 | 84篇 |
1980年 | 83篇 |
1979年 | 115篇 |
1978年 | 115篇 |
1977年 | 91篇 |
1976年 | 88篇 |
1975年 | 84篇 |
1974年 | 97篇 |
1973年 | 96篇 |
1972年 | 82篇 |
1970年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Kate Windridge Carolyn Tarrant George K Freeman Richard Baker Mary Boulton Janet Low 《The British journal of general practice》2004,54(502):364-366
We report an analysis of the qualitative phase of a study of patients' and carers' views of primary care services, focusing on their experiences of access to face-to-face general practitioner (GP) consultations during the period when new access policies were being implemented. Practices interpreted the new policy in various ways; restricted interpretations, including restriction of access to telephone booking, could cause distress to patients. Patients and carers welcomed flexible interpretations of the policy that offered choice, such as a choice of GP, or of booking in advance. 相似文献
52.
53.
Assessment of cardiovascular autonomic function. 总被引:5,自引:0,他引:5
Roy Freeman 《Clinical neurophysiology》2006,117(4):716-730
Autonomic assessment has played an important role in elucidating the role of the autonomic nervous system in diverse clinical and research settings. The techniques most widely used in the clinical setting entail the measurement of an end-organ response to a physiological provocation. The non-invasive measures of cardiovascular parasympathetic function involve the analysis of heart rate variability while the measures of cardiovascular sympathetic function assess the blood pressure response to physiological stimuli. Prolonged tilt-table testing, with or without pharmacological provocation, has become an important tool in the investigation of a predisposition to neurally mediated (vasovagal) syncope. Frequency domain analyses of heart rate and blood pressure variability, microneurography, occlusion plethysmography, laser Doppler imaging and flowmetry, and cardiac sympathetic imaging are currently research tools but may find a place in the clinical assessment of autonomic function in the future. 相似文献
54.
In part I of this review the principles governing the uses of analgesics and sedatives in the ITU were considered. In part II we shall review the drugs available considering first, symptomatic therapy and secondly, regional analgesia. 相似文献
55.
56.
Variables that affect the expansion rate and outcome of small abdominal aortic aneurysms 总被引:2,自引:0,他引:2
J L Cronenwett S K Sargent M H Wall M L Hawkes D H Freeman B J Dain J K Curé D B Walsh R M Zwolak M D McDaniel 《Journal of vascular surgery》1990,11(2):260-8; discussion 268-9
Seventy-three patients with small (less than 6 cm in diameter) abdominal aortic aneurysms (AAAs) were selected for nonoperative management and followed up with sequential ultrasound size measurements. Fifty-four men and 19 women, 51 to 89 years of age (mean 70 years), had an initial mean AAA size of 4.1 cm (anteroposterior) x 4.3 cm (lateral) diameter, with a calculated elliptic cross-sectional area of 14.3 cm2. After a mean of 37 months of follow-up, AAA area increased at a mean rate of 20% per year (3 cm2 yr; 0.4 to 0.5 cm/yr diameter). Expansion rate was not affected by initial aneurysm size. During follow-up, only 3 patients (4%) required urgent operation (1 died), 26 patients (36%) died of non-AAA causes, and 26 patients (36%) underwent elective AAA repair because of progressive size increase (1 died). Elective operations were performed at the rate of 10% per year, when mean AAA size had increased to 22 cm2 (5.1 cm in diameter). Multiple regression analysis of clinical parameters available at presentation indicated that subsequent elective AAA repair was predicted by younger age at diagnosis and larger initial aneurysm size. As anticipated, patients who underwent surgery had more rapid aneurysm expansion (5.3 cm2/yr) compared with patients who did not undergo surgery (1.6 cm2/yr; p less than 0.05). This difference was caused by more rapid expansion during later follow-up intervals among patients selected for operation and was not predicted by the change in aneurysm size observed during initial ultrasonographic follow-up. Final aneurysm size was predicted by initial size, duration of follow-up, and both systolic and diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
57.
K M McIntyre J A Vita C T Lambrew J Freeman J Loscalzo 《The New England journal of medicine》1992,327(24):1715-1720
BACKGROUND. The noninvasive prediction of pulmonary-capillary wedge pressure (PCWP) is important for the recognition and treatment of a variety of cardiovascular disorders. The response of the arterial pressure to the Valsalva maneuver has been shown to correlate with the PCWP. We therefore devised a noninvasive method to measure this pressure response at the bedside and correlated these measurements with the PCWP measured directly with a pulmonary-artery catheter. METHODS. Simultaneous, blinded, noninvasive measurements of the ratio of the final amplitude to the initial amplitude of the pulse wave form during the stress phase of the Valsalva maneuver (pulse-amplitude ratio) and direct measurements of the PCWP were obtained in 20 clinically stable patients and in 14 clinically unstable patients who were receiving vasoactive agents, 12 of whom also had endotracheal tubes in place. RESULTS. Using linear regression analysis, we found that the pulse-amplitude ratio strongly correlated with the measured PCWP over a range of base-line values from 4 to 32 mm Hg for the 20 clinically stable patients (R2 = 0.80) and the 14 clinically unstable patients (R2 = 0.85). The method also correctly predicted changes in the PCWP after the administration of nitroglycerin or furosemide and after expansion of the intravascular volume (R2 = 0.79). CONCLUSIONS. These preliminary data indicate that a simple noninvasive method can accurately predict the PCWP and changes in the PCWP in response to medical therapy. 相似文献
58.
59.
CHERYL K. ROTH AD RNC BONNIE RILEY RN CCRN SUSAN M. COHEN DSN RN 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1992,21(4):310-311
Advances in technology and complex care have enabled women with various health problems to become and remain pregnant. Consequently, health-care practitioners are seeing an increasing number of pregnant women who have aortic aneurysms. This case study describes the culturally sensitive intrapartum care of a Middle Eastern woman with ascending and descending aortic aneurysms. 相似文献
60.
Factors associated with hypertension in Nigerian civil servants 总被引:3,自引:0,他引:3
Clareann H. Bunker Ph.D. Flora A. Ukoli M.B.B.S. Martin U. Nwankwo M.B.B.S. Jackson A. Omene M.D. Glenn W. Currier M.D. Linda Holifield-Kennedy Donald T. Freeman Emanuel N. Vergis M.D. Lan Lan L. Yeh Ph.D. Lewis H. Kuller M.D. Dr.P.H. 《Preventive medicine》1992,21(6):710-722
BACKGROUND. Study of hypertension in segments of West African populations in transition toward Westernization may lead to better understanding of the high risk for hypertension among Westernized blacks. METHODS. Five hundred fifty-nine urban civil servants, ages 25-54, were recruited from six ministries of Bendel State, Nigeria. Blood pressure, physical measurements, urinary protein and glucose, fasting blood glucose, and demographic data were collected at the workplace. Subjects were classified as senior staff (professionals or administrators) or junior staff (non-administrators). RESULTS. Among 172 male senior staff, the age-adjusted rate of hypertension (diastolic blood pressure > or = 90 mm Hg, systolic blood pressure > or = 140 mm Hg, or on an antihypertensive medication) was 43% and occurrence rose dramatically from 21 to 63% across age groups 25-34 to 45-54, respectively. Among 266 male junior staff, the age-adjusted rate of hypertension was 23%, and occurrence did not rise with age. Logistic regression showed that body mass index (kg/m2), age, alcohol drinking, and being senior staff were all independently related to hypertension in men. On the other hand, the age-adjusted rate of hypertension in 121 women was 20% and was significantly related only to body mass index. CONCLUSION. Male urban civil servants appeared to have a risk for hypertension similar to that of U.S. black males. Age, body mass index, alcohol drinking, and other unidentified factors related to higher socioeconomic status were strong determinants of hypertension in this population. 相似文献