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   4214篇
  免费   344篇
  国内免费   82篇
耳鼻咽喉   13篇
儿科学   10篇
妇产科学   29篇
基础医学   287篇
口腔科学   198篇
临床医学   276篇
内科学   227篇
皮肤病学   39篇
神经病学   58篇
特种医学   391篇
外国民族医学   1篇
外科学   798篇
综合类   568篇
一般理论   1篇
预防医学   182篇
眼科学   879篇
药学   429篇
  2篇
中国医学   186篇
肿瘤学   66篇
  2024年   6篇
  2023年   102篇
  2022年   166篇
  2021年   261篇
  2020年   233篇
  2019年   151篇
  2018年   198篇
  2017年   168篇
  2016年   150篇
  2015年   154篇
  2014年   298篇
  2013年   277篇
  2012年   214篇
  2011年   200篇
  2010年   198篇
  2009年   192篇
  2008年   206篇
  2007年   188篇
  2006年   152篇
  2005年   160篇
  2004年   125篇
  2003年   98篇
  2002年   88篇
  2001年   66篇
  2000年   59篇
  1999年   63篇
  1998年   67篇
  1997年   50篇
  1996年   36篇
  1995年   50篇
  1994年   44篇
  1993年   37篇
  1992年   20篇
  1991年   27篇
  1990年   18篇
  1989年   18篇
  1988年   22篇
  1987年   13篇
  1986年   6篇
  1985年   8篇
  1984年   17篇
  1983年   7篇
  1982年   8篇
  1981年   7篇
  1980年   6篇
  1979年   3篇
  1977年   2篇
  1975年   1篇
排序方式: 共有4640条查询结果,搜索用时 15 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.
《Orthopaedics and Trauma》2022,36(3):166-174
Shoulder replacement surgery has become the gold standard treatment for end-stage glenohumeral arthropathies in patients who are fit for surgical treatment. The options include anatomic total shoulder replacement, reverse total shoulder replacement and humeral hemiarthroplasty procedures. Whilst for some patients and some indications there is little debate, decision-making for older patients with osteoarthritis remains one of the hot topics in shoulder surgery. In this article we will explore the treatment options, outcomes, and controversies.  相似文献   
3.
4.
5.
6.
7.
8.
《Seminars in Arthroplasty》2022,32(4):681-687
BackgroundThe objective of this study was to compare complication rates between patients undergoing reverse shoulder arthroplasty (RSA) after a prior open reduction and internal fixation (ORIF) for proximal humerus fracture (PHF) to those undergoing RSA as a primary treatment for PHFs, glenohumeral osteoarthritis, or rotator cuff tear arthropathy (CTA).MethodsPatients who underwent RSA between 2015 and 2020 were identified in the Mariner database. Patients were separated into 3 mutually exclusive groups: (1) RSA for osteoarthritis, rotator cuff tear, or CTA (Control-RSA); (2) RSA as a primary treatment for PHF (PHF-RSA); and (3) RSA for patients with prior ORIF of PHFs (ORIF-RSA). Ninety-day medical and 2-year postoperative surgical complications were identified. In addition, patients in the PHF-RSA group were subdivided into those undergoing RSA for PHF within 3 months of the fracture (acute) vs. those treated greater than 3 months from diagnosis (delayed). Multivariate regression was performed to control for differences in comorbidities and demographics.ResultsA total of 30,824 patients underwent primary RSA for arthritis or CTA, 5389 patients underwent RSA as a primary treatment for a PHF, and 361 patients underwent RSA after ORIF of a PHF. ORIF before RSA was associated with an increased risk of overall revision (odds ratio [OR] 2.45, P = .002), infection (OR 2.40, P < .001), instability (OR 2.43, P < .001), fracture (OR 3.24, P = .001), minor medical complications (OR 1.59, P = .008), and readmission (OR 2.55, P = .001) compared with the Control-RSA cohort. RSA as a primary treatment for PHF was associated with an increased risk of 2-year revision (OR 1.60, P < .001), infection (OR 1.51, P < .001), instability (OR 2.84, P < .001), and fracture (OR 2.54, P < .001) in addition to major medical complications (OR 2.02, P < .001), minor medical complications (OR 1.92, P < .001), 90-day emergency department visits (OR 1.26, P < .001) and 90-day readmission (OR 2.03, P < .001) compared with the Control-RSA cohort. The ORIF-RSA group had an increased risk of periprosthetic infection (OR 1.94, P = .002) when compared with the PHF-RSA cohort. There were no differences in medical or surgical complications in the RSA-PHF cohort between patients treated in an acute or delayed fashion.ConclusionRSA following ORIF of a PHF is associated with increased complications compared with patients undergoing RSA for nonfracture indications. Prior ORIF of a PHF is also an independent risk factor for postoperative infection after RSA compared with patients who undergo RSA as a primary operation for fracture. The timing of RSA as a primary operation for PHF does not appear to impact the rates of postoperative medical and surgical complications.  相似文献   
9.
目的观察造口护理辅助用品(皮肤保护膜、造口护肤粉、改良一件式造口袋)对大便失禁相关性皮炎(IAD)的防治效果。方法选择2017年3月-2018年2月本院神经外科大便失禁患者31例作为观察组,使用造口护理辅助用品进行护理;采用回顾性对照方法,将2016年3月-2017年2月本院神经外科具有同质性的大便失禁患者30例作为对照组,使用氧化锌软膏联合一次性护理垫。观察两组患者IAD的发生时间、发生率、严重程度及治疗有效率。结果观察组患者IAD发生时间明显长于对照组,Ⅰ度皮炎4例,无Ⅱ、Ⅲ度皮炎发生,对照组Ⅰ度皮炎10例,Ⅱ度3例、Ⅲ度1例,观察组IAD的发生率为12.90%,明显低于对照组46.67%,严重程度明显轻于对照组,IAD治疗有效率达100.00%,较对照组42.86%明显提高,两组比较,均P<0.05,差异有统计学意义。结论大便失禁患者使用造口护理辅助用品可预防或延缓IAD发生,减轻IAD严重程度,提高IAD治疗效果。  相似文献   
10.
The film thickness plays an important role in the performance of materials applicable to different technologies including chemical sensors, catalysis and/or energy materials. The relationship between the surface and volume of the functional layers is key to high performance evaluations. Here we demonstrate the thermophoretic deposition of different thicknesses of the functional layers designed using flame combustion of tin 2-ethylhexanoate dissolved in xylene, and measurement of thickness by scanning electron microscopy and focused ion beam. The parameters such as spray fluid concentration (differing Sn2+ content), substrate-nozzle distance and time of the spray were considered to investigate the layer growth. The results showed ≈ 23, 124 and 161 μm thickness of the SnO2 layer after flame spray of 0.1, 0.5 M and 1.0 M tin 2-EHA-Xylene solutions for 1200 s. While Sn2+ concentration was 0.5 M for all the flame sprays, the substrates placed at 250, 220 and 200 mm from the flame nozzle had layer thicknesses of 113, 116 and 132 µm, respectively. Spray time dependent thickness growth showed a linear increase from 8.5 to 152.1 µm when the substrates were flame sprayed for 30 s to 1200 s using 0.5 M tin 2-EHA-Xylene solutions. Changing the dispersion oxygen flow (3–7 L/min) had almost no effect on layer thickness. Layers fabricated were compared to a model found in literature, which seems to describe the thickness well in the domain of varied parameters. It turned out that primary particle size deposited on the substrate can be tuned without altering the layer thickness and with little effect on porosity. Applications depending on porosity, such as catalysis or gas sensing, can benefit from tuning the layer thickness and primary particle size.  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