全文获取类型
收费全文 | 50346篇 |
免费 | 8712篇 |
国内免费 | 247篇 |
专业分类
耳鼻咽喉 | 645篇 |
儿科学 | 1384篇 |
妇产科学 | 1205篇 |
基础医学 | 4993篇 |
口腔科学 | 2291篇 |
临床医学 | 9780篇 |
内科学 | 11011篇 |
皮肤病学 | 885篇 |
神经病学 | 5474篇 |
特种医学 | 1783篇 |
外国民族医学 | 2篇 |
外科学 | 6535篇 |
综合类 | 544篇 |
现状与发展 | 2篇 |
一般理论 | 34篇 |
预防医学 | 5040篇 |
眼科学 | 1073篇 |
药学 | 2810篇 |
中国医学 | 117篇 |
肿瘤学 | 3697篇 |
出版年
2024年 | 236篇 |
2023年 | 1431篇 |
2022年 | 548篇 |
2021年 | 1221篇 |
2020年 | 1457篇 |
2019年 | 992篇 |
2018年 | 2055篇 |
2017年 | 2130篇 |
2016年 | 2161篇 |
2015年 | 2336篇 |
2014年 | 2822篇 |
2013年 | 3219篇 |
2012年 | 2824篇 |
2011年 | 2986篇 |
2010年 | 2412篇 |
2009年 | 2615篇 |
2008年 | 2739篇 |
2007年 | 2494篇 |
2006年 | 2612篇 |
2005年 | 2485篇 |
2004年 | 2247篇 |
2003年 | 2125篇 |
2002年 | 1963篇 |
2001年 | 948篇 |
2000年 | 741篇 |
1999年 | 843篇 |
1998年 | 758篇 |
1997年 | 653篇 |
1996年 | 632篇 |
1995年 | 575篇 |
1994年 | 415篇 |
1993年 | 391篇 |
1992年 | 455篇 |
1991年 | 389篇 |
1990年 | 345篇 |
1989年 | 375篇 |
1988年 | 335篇 |
1987年 | 298篇 |
1986年 | 296篇 |
1985年 | 283篇 |
1984年 | 255篇 |
1983年 | 225篇 |
1982年 | 258篇 |
1981年 | 212篇 |
1980年 | 225篇 |
1979年 | 139篇 |
1978年 | 149篇 |
1977年 | 139篇 |
1976年 | 106篇 |
1975年 | 107篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
Somaini Bertino Billo Nils Dubois Jean-Alain Staub Roger 《International journal of public health》1988,33(7):340-344
International Journal of Public Health - Die Übertragungswege des HIV, welche in der Bevölkerung eine Rolle spielen, sind heute bekannt. Neben der sexuellen Übertragung, der... 相似文献
92.
To define the underlying mechanism of neuromuscular transmission failure induced by anticholinesterases, we simultaneously performed surface recordings of compound muscle action potentials (CMAPs) and intracellular recordings of miniature end-plate potentials (MEPPs), miniature end-plate current (MEPCs), and end-plate potential (EPPs) in rat diaphragms exposed in vitro to 1 × 10?4 to 2 × 10?2 mmol/L neostigmine methylsulfate. At low concentrations of neostigmine, repetitive stimulation of the phrenic nerve resulted in decrement followed by complete recuperation of CMAP amplitudes. This bimodal pattern was associated with maximal end-plate depolarization at the beginning of the stimulation period, increased MEPP amplitudes, and prolonged time constants of MEPC decays. Higher concentrations of neostigmine resulted in a unimodal decline of amplitudes of CMAPs and EPPS, reduced MEPP amplitudes, and a double exponential time course of MEPC decays. These results indicate that low concentrations of anticholinesterases impaired neuromuscular transmission by producing transient depolarization of the end-plate region. Higher concentrations induced desensitization and direct blockade of the end-plate receptor channel, probably in its open conformation. © 1993 John Wiley & Soncs, Inc. 相似文献
93.
C. R. Goucke MB ChB FFARACS J. P. Keaveny MB BCh BAO FFARCS B Kay DMSc MB ChB FFARCS T. E. J. Healy MSc MD FFARCS M. Ryan MB ChB FFARCS 《Anaesthesia》1990,45(4):329-331
Eighty-two outpatients who received general anaesthesia for surgical removal of maxillary or mandibular third molars were given either diclofenac 75 mg or nefopam 20 mg intramuscularly for postoperative pain control. They and the control group were also allowed oral paracetamol as required. The results showed that there was no significant pain relief from these single intramuscular injections. 相似文献
94.
Hartley Dean MA PhD Keir Gale BA Roger Woods BA MA 《Health & social care in the community》1996,4(6):338-346
The new complaints procedures which local authority social services departments have been required to introduce represent an important mechanism for managing the change of culture associated with recent community care reforms. They also represent a new genre in mechanisms of redress for welfare recipients. This paper reports the findings of a study which has observed considerable diversity in the ways in which local authorities are interpreting the nature and purposes of the new procedures and, in particular, the functions of review panels established under those procedures. Variations in the composition of panels, in the style of review panel proceedings, in perceptions of the panels' powers, and in the ways that complaints and complainants are constituted are all discussed. Attention is drawn to four competing interpretations of the review panels' role and to the need for these to be clarified and prioritised. 相似文献
95.
Duncan W. Blake Roger G. Evans John Ludbrook Oscar U. Petring 《Clinical and experimental pharmacology & physiology》1994,21(5):383-396
1. Eight conscious rabbits were repeatedly subjected to progressive reduction in central blood volume by gradually inflating a thoracic inferior vena caval-cuff so cardiac index (CI) fell at a constant 8.5% of baseline/min. 2. Caval-cuff inflations were performed after 10 min exposure to 100, 21, 12–14 and 8–10% O2, with and without the addition of 3–4% CO2, in randomized order. 3. The haemodynamic response to progressive reduction in central blood volume was biphasic. In Phase I, systemic vascular conductance index (SVCI) fell linearly, supporting mean arterial pressure (MAP). When CI had fallen to a critical level, Phase II occurred in which SVCI rose abruptly, MAP plummeted and respiratory drive progressively increased. 4. During Phase I, there were independent linear relationships between Pao2 (but not Pao2) and the rates at which SVCI and MAP changed during the progressive fall of CI. The higher the level of Pao2, the greater was the rate of fall of SVCI and the less the rate of fall of MAP. 5. There was an inverted U-shaped effect of Pao2, on the level of CI at which Phase II occurred: (a) during hyperoxia (100% O2), Phase II occurred later than during normoxia (21% O2); and (b) across the normoxic and hypoxic gas mixtures (21–8% O2, with and without added CO2), there was an independent linear relationship between Pao2 (but not Pao2 or Pao2×Pao2) and the level of CI at which Phase II occurred. That is, the lower the level of Pao2, the later was the onset of Phase II. This interaction is best explained by an increased level of central sympathetic vasoconstrictor drive during hypoxia. 相似文献
96.
David A Todd MSc PhD John Kennedy FRACO † Sharyn Roberts RN Jane Watts RN Kim Psaila RN BApplSc Elizabeth John MD FRACP 《Clinical & experimental ophthalmology》1994,22(1):19-23
From January 1986 to December 1991 we examined the eyes of 206 infants born at Westmead Hospital, Neonatal Intensive Care Unit who were less than 29 weeks' gestation at birth to determine the incidence of retinopathy of prematurity. Eighty-five infants (41.3%) had no retinopathy of prematurity (ROP) in either eye, 82 infants had stages 1 or 2 ROP (39.8%), 29 had stage 3 ROP (14.1%) and 11 had stage 4 ROP (5.3%). Of these, cryotherapy was performed in 18; six now have bilateral retinal detachment and are blind The more severe stages of ROP were significantly associated with an increase in the number of days of oxygen supplementation, an increase in the number of days of mechanical ventilation and the presence of patent ductus arteriosus. Infants receiving steroids for mechanical ventilator dependence had a significantly greater chance of requiring cryotherapy (11 or 22 receiving steroids versus seven of 43 without steroids; P < 0.01). 相似文献
97.
Gregor McWalter MA MSc Hugh Toner MA DipCouns MSc CPsychol Alison Corser BSc MPhil CPsychol Jenny Eastwood MBChB DipSocMed FRCPsych Mary Marshall MA DSA DASS Tony Turvey BSc MAppSci CPsychol 《Health & social care in the community》1994,2(4):213-219
The concept of need and the practice of needs assessment are both subject to a wide range of interpretations, to the likely detriment of individual assessments and to multidisciplinary working. Clear definition is important for individual assessment, for the development of multidisciplinary tools and in gathering planning information. The concept of need is clarified, firstly by distinguishing between need and the difficulties that engender it, and secondly through a taxonomy of need. These assist clear definitions of both need and needs assessment when linked with a consideration of the current help a person receives and a specification of the type of help required by a person to meet their needs. Such definitions have implications for the role of needs assessment in individual assessment, service evaluation, service management and planning and in the development of multidisciplinary needs assessment tools. 相似文献
98.
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
99.
M L Lachurie L A Mercier Y Castonguay T K Leung 《Journal of the American Society of Echocardiography》1992,5(4):456-458
We describe a case of aortopulmonary fistula in which the correct diagnosis was made by transthoracic echocardiography. The transesophageal approach, because of severe aortic dilatation, failed to provide the correct diagnosis, underlining the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms. 相似文献
100.
We examine the relationships between glycemic carbohydrate and its effects on short-term satiety and food intake. Both high- and low-glycemic carbohydrates have an impact on satiety, but their effects have different time courses. High-glycemic carbohydrates are associated with a reduction in appetite and food intake in the short term (e.g., one hour), whereas the satiating effects of lower-glycemic carbohydrates appear to be delayed (e.g., 2 to 3 hours). There is no consistent evidence that an increase in blood glucose, either acute or sustained, is the primary determinant of their effects on food intake and satiety. Many other preabsorptive and postabsorptive signals for satiety exist and may be the determining factors. Further studies are needed to delineate the role of glycemic carbohydrates and their mechanisms of action in determining satiety. 相似文献