全文获取类型
收费全文 | 1230篇 |
免费 | 78篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 73篇 |
妇产科学 | 5篇 |
基础医学 | 157篇 |
口腔科学 | 11篇 |
临床医学 | 229篇 |
内科学 | 285篇 |
皮肤病学 | 8篇 |
神经病学 | 88篇 |
特种医学 | 145篇 |
外国民族医学 | 2篇 |
外科学 | 101篇 |
综合类 | 19篇 |
预防医学 | 40篇 |
眼科学 | 8篇 |
药学 | 91篇 |
中国医学 | 2篇 |
肿瘤学 | 42篇 |
出版年
2022年 | 10篇 |
2021年 | 11篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 36篇 |
2013年 | 41篇 |
2012年 | 23篇 |
2011年 | 35篇 |
2010年 | 36篇 |
2009年 | 26篇 |
2008年 | 36篇 |
2007年 | 29篇 |
2006年 | 31篇 |
2005年 | 33篇 |
2004年 | 35篇 |
2003年 | 30篇 |
2002年 | 30篇 |
2001年 | 30篇 |
2000年 | 32篇 |
1999年 | 44篇 |
1998年 | 51篇 |
1997年 | 68篇 |
1996年 | 50篇 |
1995年 | 39篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 25篇 |
1991年 | 32篇 |
1990年 | 16篇 |
1989年 | 26篇 |
1988年 | 36篇 |
1987年 | 30篇 |
1986年 | 35篇 |
1985年 | 32篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 16篇 |
1975年 | 18篇 |
1973年 | 8篇 |
1966年 | 8篇 |
排序方式: 共有1316条查询结果,搜索用时 140 毫秒
1.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
2.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
3.
4.
5.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
6.
SUMMARY. This study compared plateletpheresis on the Haemonetics PCS Plus (PCS Plus) and the Baxter Autopheresis C (Auto C) using the same 100 selected donors. The number of packs meeting UK BTS/NIBSC specification (>2.2 times 1011 platelets per pack) was achieved by 99% of PCS Plus and 82% of Auto C procedures. The positive correlation found between donor precount and final platelet yield was better for the PCS Plus. Both machines met U.K. specification for white-cell contamination but this was significantly greater for the Auto C. Plasma yields were similar.
As a result of this study we chose to use the PCS Plus for routine plateletpheresis in our unit. This has enabled us not only to comply with UK BTS/NIBSC specifications for apheresis platelets easily and cost effectively but also to meet our own higher specification (2.75 times 1011 platelets per pack) using existing staff and without extending the working day. 相似文献
As a result of this study we chose to use the PCS Plus for routine plateletpheresis in our unit. This has enabled us not only to comply with UK BTS/NIBSC specifications for apheresis platelets easily and cost effectively but also to meet our own higher specification (2.75 times 10
7.
Improvement in quality of life after initiation of lamotrigine therapy in patients with epilepsy in a naturalistic treatment setting. 总被引:1,自引:0,他引:1
Hervé Allain Stéphane Schück Fatima Nachit-Ouinekh Perrine Plouin Anne-Marie Brunon Jacques Boulliat Florence Mercier Alain Slama Michel Baulac Abdelkader El Hasnaoui 《Seizure》2007,16(2):173-184
Quality of life is impaired in patients with epilepsy and can be improved by effective therapy. Randomised clinical trials have shown that lamotrigine treatment is associated with improved quality of life. However, little information is available on quality of life or treatment effects in patients with epilepsy in the general population. The objective of this study was to estimate the impact of lamotrigine on quality of life in a naturalistic treatment setting. The study included adult patients with epilepsy in whom lamotrigine therapy was initiated. Each subject completed the Quality of Life in Epilepsy Inventory (QOLIE)-31 quality of life questionnaire at inclusion and at a follow-up visit in the next 4 months. Demographic information and medical history were provided by the investigator. These were evaluated as potential determinants of change in quality of life using logistic regression. Three hundred and forty-one patients were evaluated, 192 starting lamotrigine in combination with another drug, 90 as a first-line monotherapy, 45 as a switch from another drug and 14 as a reduction to monotherapy from a previous combination. Baseline scores on the QOLIE-31 ranged from 53.8 in the combination group to 69.5 in the first-line group. 34.6% of patients were considered to be responders, with no significant differences between treatment regimen. Most improvement was seen for the energy-fatigue and medication effects subscales and, for the first-line group, seizure worry. Seizure type was the only determinant of improvement of quality of life identified. In conclusion, lamotrigine treatment is associated with improved quality of life, regardless of treatment regimen. 相似文献
8.
9.
10.
In reaction time (RT) tasks, event-related potentials (ERPs) reveal a response-locked negative wave when subjects commit errors. This wave, termed "error negativity" (Ne) or "error-related negativity" (ERN), is thought to index response-monitoring processes. With conventional monopolar recordings, this negativity is hardly seen on correct responses, likely overlapped by a large positive wave. Indeed, after Laplacian transformation (a spatial high-pass filter), a small Ne-like wave is unmasked. Recently, it has been shown that the positivity on monopolar recordings was larger for correct responses preceding an error than for correct responses preceding a correct trial. After Laplacian transformation, it appears that this effect is due, at least in part, to a decrease of the Ne-like wave on correct responses preceding an error. This result indicates that, as the Ne on errors, the Ne-like wave on correct responses is sensitive to performance and hence is likely related to response-monitoring processes. 相似文献