全文获取类型
收费全文 | 3426篇 |
免费 | 231篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 187篇 |
妇产科学 | 41篇 |
基础医学 | 436篇 |
口腔科学 | 90篇 |
临床医学 | 445篇 |
内科学 | 587篇 |
皮肤病学 | 40篇 |
神经病学 | 230篇 |
特种医学 | 362篇 |
外国民族医学 | 1篇 |
外科学 | 364篇 |
综合类 | 61篇 |
一般理论 | 1篇 |
预防医学 | 356篇 |
眼科学 | 32篇 |
药学 | 158篇 |
中国医学 | 3篇 |
肿瘤学 | 211篇 |
出版年
2023年 | 12篇 |
2021年 | 30篇 |
2020年 | 17篇 |
2019年 | 29篇 |
2018年 | 55篇 |
2017年 | 33篇 |
2016年 | 41篇 |
2015年 | 56篇 |
2014年 | 82篇 |
2013年 | 108篇 |
2012年 | 125篇 |
2011年 | 142篇 |
2010年 | 83篇 |
2009年 | 84篇 |
2008年 | 112篇 |
2007年 | 141篇 |
2006年 | 128篇 |
2005年 | 150篇 |
2004年 | 131篇 |
2003年 | 118篇 |
2002年 | 102篇 |
2001年 | 88篇 |
2000年 | 111篇 |
1999年 | 108篇 |
1998年 | 138篇 |
1997年 | 100篇 |
1996年 | 111篇 |
1995年 | 80篇 |
1994年 | 74篇 |
1993年 | 98篇 |
1992年 | 70篇 |
1991年 | 63篇 |
1990年 | 61篇 |
1989年 | 95篇 |
1988年 | 54篇 |
1987年 | 73篇 |
1986年 | 59篇 |
1985年 | 57篇 |
1984年 | 46篇 |
1983年 | 31篇 |
1982年 | 37篇 |
1981年 | 39篇 |
1980年 | 36篇 |
1979年 | 25篇 |
1978年 | 37篇 |
1977年 | 25篇 |
1976年 | 28篇 |
1975年 | 30篇 |
1974年 | 18篇 |
1972年 | 19篇 |
排序方式: 共有3671条查询结果,搜索用时 0 毫秒
71.
George S. Stergiou Eamon Dolan Anastasios Kollias Neil R. Poulter Andrew Shennan Jan A. Staessen ZhenYu Zhang Michael A. Weber 《Journal of clinical hypertension (Greenwich, Conn.)》2018,20(7):1122
According to the established validation protocols, a typical validation study of a blood pressure (BP) monitor includes general population adults with normal or elevated BP. It is recognized, however, that the automated (oscillometric) BP monitors may have different accuracy or uses in some special populations compared with adults in the general population. Thus, an automated BP monitor with proven accuracy in a general population of adults may not be accurate in a special population, and therefore separate validation is needed. Recognized special populations deserving separate validation are those for which there is theoretical, and also clinical evidence, that the accuracy of BP monitors in these groups differs from that in the general population. Young children, pregnant women (including those with preeclampsia), individuals with arm circumference >42 cm, and patients with atrial fibrillation are regarded as special populations. Adolescents, individuals older than 80 years, and patients with end‐stage renal disease or diabetes mellitus have also been considered as possible special groups, but there is still inadequate evidence of altered accuracy of BP monitors in these subjects. Validation studies should be performed in special populations and evaluated separately after the BP‐measuring device has successfully undergone a validation study in a general population (unless the test device is intended only for a special population). This article discusses issues relating to the measurement of BP and the diagnosis of hypertension in selected special populations, as well as in low‐resource settings, where a simplified yet efficient evaluation strategy is necessary. 相似文献
72.
73.
74.
75.
James P. Dolan Taranjeet Kaur Brian S. Diggs Renato A. Luna Paul H. Schipper Brandon H. Tieu Brett C. Sheppard John G. Hunter 《Surgical endoscopy》2013,27(11):4094-4103
Background
The aim of this study was to examine the impact of the Charlson Comorbidity Index-Grade (CCI-G) on predicting outcomes and overall survival after open and minimally invasive esophagectomy (MIE).Methods
One hundred and forty-six patients who underwent esophagectomy between 1995 and 2011 for stage II and III cancer were selected and separated into open esophagectomy (Open) and MIE groups. Risk adjustment was performed using the CCI-G. The outcomes of interest were operative time, estimated blood loss (EBL), lymph node harvest, length of hospital stay (LOS), major complications, 30-day mortality, and overall survival.Results
Sixty-four patients (44 %) underwent Open while 71 (49 %) had MIE. An additional (7 %) were converted and classified with MIE. There was no significant difference between MIE and Open in terms of operative time. MIE had less EBL (mean difference = 234 mL, p < 0.001), higher lymph node harvest (mean = 7.4 nodes, p < 0.001), and shorter LOS (median = 1.5 days, p = 0.02). Atrial arrhythmias were the most frequent complication, occurring in 33 % of patients in both the MIE and the Open group (p = 0.988). Thirty-day mortality was 2 % for MIE and 5 % for Open (p = 0.459). Five-year survival was 41 % for MIE and 33 % for Open (p = 0.513). Operative approach, age, gender, BMI, clinical stage, and neoadjuvant therapy did not have any significant effect on the outcomes or overall survival. CCI-G influenced outcomes with operative time, LOS, cardiovascular complication, and anastomotic leak rate, favoring CCI-G 0 compared to CCI-G 3. Overall survival was worse for CCI-G 1 in comparison with CCI-G 0 [hazard ratio (HR) 1.99, p = 0.027].Conclusions
MIE is a safe alternative to open esophagectomy for the treatment of locally advanced esophageal cancer. The presence of comorbidities increased operative time, length of hospital stay, and postoperative complications while worsening overall survival. 相似文献76.
The focus on quality of life issues in wound care has justly taken a far greater importance. With the acceptance that pain can be a major factor to the patient, and in particular, pain at dressing change comes the opportunity for avoidance and/or reduction strategies. Whilst pain has been associated with wound infection for millennia, it is only much more recently that this has received due attention from research and clinical practice. In this study, the nature of pain, changes in pain and pain associated with infection are the focal points. A Delphi approach, now a frequently used tool in wound care research, has been used to obtain expert opinion on these aspects of management. 相似文献
77.
Bianca C. Wittmann Geoffrey C. Tan John E. Lisman Raymond J. Dolan Emrah Düzel 《Neuropsychologia》2013
Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. We also investigated how the neural processing of appetitive and aversive motivation and episodic memory were modulated by dopaminergic mechanisms. To that end, participants were selected on the basis of their genotype for a variable number of tandem repeat polymorphism of the dopamine transporter (DAT) gene. The resulting groups were carefully matched for the 5-HTTLPR polymorphism of the serotonin transporter gene. Recognition memory for cues from both motivational categories was enhanced in participants homozygous for the 10-repeat allele of the DAT, the functional effects of which are not known yet, but not in heterozygous subjects. In comparison with heterozygous participants, 10-repeat homozygous participants also showed increased striatal activity for anticipation of motivational outcomes compared to neutral outcomes. In a subsequent memory analysis, encoding activity in striatum and hippocampus was found to be higher for later recognized items in 10-repeat homozygotes compared to 9/10-repeat heterozygotes. These findings suggest that processing of appetitive and aversive motivation in the human striatum involve the dopaminergic system and that dopamine plays a role in memory for both types of motivational information. In accordance with animal studies, these data support the idea that encoding of motivational events depends on dopaminergic processes in the hippocampus. 相似文献
78.
Background: Advantages of cross‐pin retained implant supported restorations (ISRs) include predictable retrieval and predictable retention. Unlike direct to fixture (DTF) or cement retained restorations, the prosthetic design of a cross‐pinned restoration retains gaps at the interfaces between the crown, abutment and cross‐pin screw. These spaces permit leakage into the suprastructure and gasket placement has been recommended to prevent this leakage. Methods: Five different gaskets were assessed for their ability to prevent leakage into a cross‐pinned ISR. The gaskets tested were: cement admixture on the cross‐pin screw; cement admixture on the inner surface of the coping and the cross‐pin screw; cement admixture on the inner surface of the coping only; cement admixture placed 1 mm from the margin of the coping and a filler placed in the abutment chimney. Results: Only gaskets which sealed both the cross‐pin screw interface and the abutment‐crown interface prevented leakage. A filler placed in the abutment chimney prevented leakage into this space but did not prevent fluid accumulating between the coping and abutment. Conservative placement of cement at the margin of the coping failed to prevent leakage. Conclusions: Cement gaskets may effectively prevent leakage into a cross‐pinned ISR. However, the use of a cement as a gasket has to be weighed against the issue of predictable retrieval, cement extrusion and incomplete seating. 相似文献
79.
80.