首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6365篇
  免费   449篇
  国内免费   32篇
耳鼻咽喉   51篇
儿科学   322篇
妇产科学   114篇
基础医学   909篇
口腔科学   126篇
临床医学   600篇
内科学   1454篇
皮肤病学   89篇
神经病学   747篇
特种医学   125篇
外科学   591篇
综合类   52篇
一般理论   10篇
预防医学   602篇
眼科学   49篇
药学   392篇
中国医学   9篇
肿瘤学   604篇
  2023年   75篇
  2022年   41篇
  2021年   194篇
  2020年   119篇
  2019年   168篇
  2018年   193篇
  2017年   135篇
  2016年   177篇
  2015年   182篇
  2014年   262篇
  2013年   347篇
  2012年   494篇
  2011年   518篇
  2010年   278篇
  2009年   256篇
  2008年   426篇
  2007年   438篇
  2006年   395篇
  2005年   438篇
  2004年   410篇
  2003年   326篇
  2002年   328篇
  2001年   38篇
  2000年   19篇
  1999年   40篇
  1998年   57篇
  1997年   51篇
  1996年   48篇
  1995年   42篇
  1994年   36篇
  1993年   27篇
  1992年   23篇
  1991年   21篇
  1990年   19篇
  1989年   15篇
  1988年   16篇
  1987年   20篇
  1986年   12篇
  1985年   12篇
  1984年   12篇
  1983年   15篇
  1982年   17篇
  1981年   15篇
  1980年   11篇
  1979年   8篇
  1978年   9篇
  1977年   5篇
  1976年   5篇
  1975年   12篇
  1970年   4篇
排序方式: 共有6846条查询结果,搜索用时 62 毫秒
1.
BackgroundIn shoulder arthroplasty, bone resorption around the stem can lead to stem loosening and makes surgery difficult at the time of revision. Proximal bone resorption after reverse shoulder arthroplasty can cause instability because of a decrease of deltoid wrapping effect. As factors of the stem itself, such as stem coating, shape, length, and use of bone cement, may also affect bone resorption, a single-stem model should be used to compare bone resorptions between different pathologies and surgical procedures. However, to date, a few reports have compared these differences in detail using a single-stem model. Therefore, we investigated the prevalence and location of humeral bone resorption in a single-stem model.MethodsThe study included 100 shoulders that underwent anatomical total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with a single uncemented humeral stem from 2008 to 2018. The patients were 31 men and 69 women. The mean age at surgery was 72.9 years (range, 41-86 years). The patients were divided into three groups: especially, 25, 61, and 14 shoulders received TSA for primary osteoarthritis without rotator cuff tears (TSA group), HHR using an anatomical head with rotator cuff repair for cuff tear arthropathy (CTA) (HHR group), and HHR using a CTA head without rotator cuff repair (CTA group), respectively. Patients were monitored for a mean of 56 months (range, 12-98 months). The location of bone resorption was divided into seven zones as follows: zone 1, greater tuberosity; zone 2, lateral diaphysis; zone 3, lateral diaphysis beyond the deltoid tuberosity; zone 4, tip of the stem; zone 5, medial diaphysis beyond the deltoid tuberosity; zone 6, medial diaphysis; and zone 7, calcar region. The degree of bone resorption was classified from grade 0 to 4.ResultsBone resorption of grade 3 or higher was significantly more frequent at the greater tuberosity in the HHR and CTA groups (P < .001 and P < .001, respectively) than that in the TSA group. Grade 4 bone resorption was significantly more frequent in the CTA than that in the TSA and HHR groups in zone 1 (P = .016 and P = .041, respectively).ConclusionThe state of attachment of the rotator cuff to the greater tuberosity might affect bone resorption at the greater tuberosity, such as the greater tuberosity after shoulder arthroplasty. In cases of shoulder arthroplasty for arthropathy with rotator cuff tear, performing rotator cuff repair might prevent bone resorption.Level of evidenceLevel IV; Prognosis Study  相似文献   
2.
3.
Journal of Neuro-Oncology - Magmas (mitochondria-associated protein involved in granulocyte–macrophage colony-stimulating factor signal transduction) is a nuclear gene that encodes the...  相似文献   
4.
5.
6.
IntroductionSugar sweetened beverage (SSB) consumption among U.S. adolescents exceeds current recommendations. This study examines relationships between SSB intake and reported prediabetes.MethodData are from the 2019 Minnesota Student Survey (N = 125,375). Logistic regression was used to examine relationships between frequencies for SSB intake and youth reported prediabetes in analytic models adjusting for demographic and other cardiometabolic indicators. Additional analyses examined relationships between consumption of fruit juice, milk, and water, and prediabetes.ResultsOne in four youth reported consumption of at least one SSB daily. In fully adjusted models, a range of SSB intake frequencies were significantly associated with increased odds of reported prediabetes. All intake frequencies for water were associated with reduced odds of prediabetes.DiscussionEfforts to reduce SSB intake among adolescents are warranted to support cardiometabolic health. Study findings are consistent with current guidance identifying water as the preferred drink for adolescents’ hydration needs.  相似文献   
7.
8.
A Bochdalek hernia (BH) is a congenital abnormality with incomplete closure of the diaphragm. It is usually manifested in infants but rarely in adults. Here, we report an adult patient with gastric volvulus and giant BH that were safely repaired by endoscopic reduction and elective laparoscopic surgery, respectively. A 79-year-old woman presented with left upper abdominal pain but no history of trauma. CT revealed a giant BH with gastric volvulus. After emergency endoscopic reduction of the volvulus, elective laparoscopic repair of the BH was performed. The 8 × 8-cm defect was repaired with interrupted nonabsorbable sutures and a mesh. The patient's postoperative course was uneventful, and no complications or recurrence were observed in the 6 months that followed.  相似文献   
9.
With the rapid development of computer‐aided design/computer‐aided manufacturing (CAD /CAM ) systems, the application of zirconia in removable partial dentures is expected to expand. Clasps composed of zirconia should improve esthetics without inducing the risk of metal allergy. The aim of this study was to examine the fatigue resistance of yttria‐stabilized tetragonal zirconia polycrystal (Y‐TZP) clasps for removable partial dentures. Yttria‐stabilized tetragonal zirconia polycrystal and cobalt‐chromium (Co‐Cr) alloy were prepared using CAD /CAM systems. Specimens were either of the semicircular type or of the flat type, with cross‐sectional areas of taper ratios of 0.50, 0.75, and 1.00. All specimens were tested using the cantilever test and the constant displacement fatigue test, and data were analyzed using ANOVA . During the cantilever test, the maximum displacement prior to fracture was greater than the required undercut, and the semicircular‐type specimen exhibited a higher fracture load than the flat type. None of the specimens displayed permanent deformation and showed almost the same degree of deformation after fatigue testing. A lower taper ratio was associated with lower average load values and greater displacement. Within the limitations of this study, it was possible to conclude that Y‐TZP provides the required undercut and adequate retentive force for removable partial denture clasps. Additionally, Y‐TZP and Co‐Cr alloy had almost the same degree of deformation even after the simulated lifespan of removable partial dentures.  相似文献   
10.
Temporal synchrony between odor and taste plays an important role in flavor perception. When we investigate temporal synchrony between odor and taste, it is necessary to pay attention not only to physical simultaneity of the presentation of olfactory and gustatory stimuli, but also to the perceptual simultaneity between the two stimuli. In this study, we examined short-latency brain activity underlying synchrony perception for olfactory–gustatory combinations. While five female participants performed a simultaneity judgment (SJ) task using soy sauce odor and salt solution, single-channel event-related potentials (ERPs) were recorded at the position of Cz. In each trial, the participant was asked whether olfactory and gustatory stimuli were perceived simultaneously or successively. Based on the judgment responses acquired from participants (i.e., simultaneous or successive), ERP data were classified into two datasets. The means of ERPs from each participant were calculated for each type of judgment response, considering the onset of olfactory or gustatory stimuli (OERPs or GERPs, respectively) as the starting point. The latencies of the P1 component of GERPs were very similar between simultaneous and successive judgment responses, whereas the P1 amplitudes differed significantly. These results indicated that neural activity affecting SJ for an olfactory–gustatory combination is generated during a period of about 130 ms from the onset of gustatory stimulus. Thus, olfactory and gustatory information processing related to flavor perception (more specially, synchrony perception between odor and taste) might be initiated at a relatively early stage of the central pathway.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号