全文获取类型
收费全文 | 41449篇 |
免费 | 2957篇 |
国内免费 | 161篇 |
专业分类
耳鼻咽喉 | 501篇 |
儿科学 | 1350篇 |
妇产科学 | 553篇 |
基础医学 | 4999篇 |
口腔科学 | 526篇 |
临床医学 | 4276篇 |
内科学 | 9224篇 |
皮肤病学 | 703篇 |
神经病学 | 3941篇 |
特种医学 | 1669篇 |
外科学 | 7223篇 |
综合类 | 360篇 |
一般理论 | 81篇 |
预防医学 | 3133篇 |
眼科学 | 1156篇 |
药学 | 2149篇 |
中国医学 | 39篇 |
肿瘤学 | 2684篇 |
出版年
2024年 | 32篇 |
2023年 | 401篇 |
2022年 | 685篇 |
2021年 | 1564篇 |
2020年 | 772篇 |
2019年 | 1287篇 |
2018年 | 1559篇 |
2017年 | 1069篇 |
2016年 | 1170篇 |
2015年 | 1254篇 |
2014年 | 1753篇 |
2013年 | 2067篇 |
2012年 | 3478篇 |
2011年 | 3470篇 |
2010年 | 1889篇 |
2009年 | 1681篇 |
2008年 | 2807篇 |
2007年 | 2741篇 |
2006年 | 2645篇 |
2005年 | 2500篇 |
2004年 | 2444篇 |
2003年 | 2044篇 |
2002年 | 1885篇 |
2001年 | 240篇 |
2000年 | 171篇 |
1999年 | 240篇 |
1998年 | 357篇 |
1997年 | 313篇 |
1996年 | 232篇 |
1995年 | 220篇 |
1994年 | 166篇 |
1993年 | 163篇 |
1992年 | 110篇 |
1991年 | 108篇 |
1990年 | 80篇 |
1989年 | 70篇 |
1988年 | 50篇 |
1987年 | 61篇 |
1986年 | 59篇 |
1985年 | 60篇 |
1984年 | 74篇 |
1983年 | 84篇 |
1982年 | 103篇 |
1981年 | 78篇 |
1980年 | 53篇 |
1979年 | 27篇 |
1978年 | 33篇 |
1977年 | 34篇 |
1976年 | 21篇 |
1973年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
OBJECTIVE: Although VATS lobectomy has been demonstrated to be safe and effective, the technique is not widely practiced. This may, in part, reflect difficulty in acquiring appropriate skills. We have evaluated the effect of experience and training on surgical outcomes during the development and establishment of a VATS lobectomy programme. METHODS: Data were collected prospectively on 276 consecutive VATS lobectomies under the care of a single consultant as either the primary surgeon or supervising four trainees. The series was divided into cohorts of 46 patients. These comprised one trainee cohort and five sequential consultant cohorts. Statistical analysis utilised standard tests of significance. RESULTS: Increasing experience with the VATS lobectomy programme was associated with a significant reduction in operating time but intraoperative blood loss and postoperative stay were not influenced by increasing consultant surgical experience. Training was associated with a mean increase of 22 min operative time (p=0.0005) but no increase in intraoperative blood loss, morbidity, mortality or postoperative stay. The 46 trainee operative times were similar to the first 46 consultant cases. CONCLUSIONS: VATS lobectomy can be safely taught to trainee thoracic surgeons. However, in view of the limited number of centres undertaking VATS lobectomy, training should be coordinated at a national level to concentrate experience and improve uptake of this technique. 相似文献
83.
Jonathan Parke Mark D. Griffiths Adrian Parke 《International journal of mental health and addiction》2007,5(1):39-52
Background Research has demonstrated that optimism and “positive illusions” can be used a coping mechanism among those facing adversity.
Gamblers are a little studied group who also experience adversity and uncertainty. They often feel considerable levels of
frustration, guilt, anger and a sense of feeling cheated after making significant losses. In order to deal with such feelings
it is hypothesized that these individuals will search for positive consequences from their behaviour in order to offset this
negative affect.
Objectives To (1) determine whether after gambling, gamblers compensate and reduce negative affect by identifying positive consequences
from experiencing a loss, and (2) identify types of strategies which gamblers employ and consider how these should be classified.
Materials and Methods Eighty-seven regular slot machine gamblers were interviewed in a variety of environments housing slot machines. Each participant
was asked a series of questions in a semi-structured format, to explore possible styles of positive thinking.
Results Nine types of ‘positive thinking’ experienced by gamblers were identified. These included Comparative thinking, Prophylactic thinking, Biased frequency thinking, Responsibility avoidance, Chasing Validation, Prioritization,
Resourcefulness, Thoughtfulness, and Fear Reduction. Gamblers who were positive thinkers experienced significantly less guilt than non-positive thinkers.
Conclusions While reduction of negative affect may be perceived as positive in many other contexts, it is argued that it may counteract
efforts to promote responsible gambling. Clinical implications and directions for future research are discussed. 相似文献
84.
Does changing from mercury to electronic blood pressure measurement influence recorded blood pressure? An observational study. 下载免费PDF全文
Richard J McManus Jonathan Mant Martyn R P Hull F D Richard Hobbs 《The British journal of general practice》2003,53(497):953-956
Mercury sphygmomanometers have been commonly used in primary care to measure blood pressure but are associated with bias. Electronic blood pressure machines are being introduced in many practices and have anecdotally been associated with higher recorded blood pressure. This study examined recorded blood pressure in four practices before and after electronic blood pressure machine introduction. No consistent change in mean blood pressure was apparent following their introduction, but there was a large and significant fall in terminal digit preference suggesting improved precision of recording. 相似文献
85.
Deacon E. Harle Keri Davies Rakhee Shah Syma Hussain Susan Cowling Tejinder K. Panesar Jonathan Bourton Bruce J. W. Evans 《Ophthalmic & physiological optics》2007,27(1):100-105
Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use. 相似文献
86.
87.
Delineating the sites and progression of in vivo atrophy in multiple system atrophy using fluid-registered MRI. 总被引:1,自引:0,他引:1
Jonathan M Schott Jessica E Simon Nick C Fox Andrew P King M Nadeem Khan Lisa Cipolotti Dominic C Paviour John M Stevens Martin N Rossor 《Movement disorders》2003,18(8):955-958
We describe the pattern and progression of atrophy delineated using fluid registration of serial magnetic resonance imaging scans in a case of multiple system atrophy (MSA). The in vivo findings were consistent with those found at postmortem, including significant supratentorial atrophy concurrent with an unusual degree of cognitive impairment for MSA. 相似文献
88.
89.
Michael P Hill Erwan Bezard Steven G McGuire Alan R Crossman Jonathan M Brotchie Ann Michel Renee Grimée Henrik Klitgaard 《Movement disorders》2003,18(11):1301-1305
Long-term dopamine replacement therapy of Parkinson's disease leads to the occurrence of dyskinesias. Altered firing patterns of neurons of the internal globus pallidus, involving a pathological synchronization/desynchronization process, may contribute significantly to the genesis of dyskinesia. Levetiracetam, an antiepileptic drug that counteracts neuronal (hyper)synchronization in animal models of epilepsy, was assessed in the MPTP-lesioned marmoset model of Parkinson's disease, after coadministration with (1) levodopa (L-dopa) or (2) ropinirole/L-dopa combination. Oral administration of levetiracetam (13-60 mg/kg) in combination with either L-dopa (12 mg/kg) alone or L-dopa (8 mg/kg)/ropinirole (1.25 mg/kg) treatments was associated with significantly less dyskinesia, in comparison to L-dopa monotherapy during the first hour after administration. Thus, new nondopaminergic treatment strategies targeting normalization of abnormal firing patterns in basal ganglia structures may prove useful as an adjunct to reduce dyskinesia induced by dopamine replacement therapy without affecting its antiparkinsonian action. 相似文献
90.