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   413篇
  免费   27篇
  国内免费   1篇
耳鼻咽喉   16篇
儿科学   16篇
妇产科学   15篇
基础医学   34篇
口腔科学   26篇
临床医学   40篇
内科学   100篇
皮肤病学   4篇
神经病学   22篇
特种医学   7篇
外科学   87篇
综合类   4篇
预防医学   16篇
眼科学   13篇
药学   23篇
肿瘤学   18篇
  2023年   11篇
  2022年   22篇
  2021年   28篇
  2020年   12篇
  2019年   23篇
  2018年   17篇
  2017年   21篇
  2016年   29篇
  2015年   24篇
  2014年   33篇
  2013年   28篇
  2012年   51篇
  2011年   35篇
  2010年   19篇
  2009年   10篇
  2008年   15篇
  2007年   16篇
  2006年   10篇
  2005年   13篇
  2004年   5篇
  2003年   6篇
  2002年   10篇
  2001年   1篇
  1998年   2篇
排序方式: 共有441条查询结果,搜索用时 15 毫秒
11.
A novel polymerization mechanism transformation strategy, involving anionic ring‐opening polymerization and photoinduced cationic polymerization, is successfully applied for the synthesis of poly(ethylene oxide)‐graft‐poly(isobutyl vinyl ether) (PEO‐g‐PIBVE). First, poly(ethylene oxide‐co‐ethoxyl vinyl glycidyl ether) [P(EO‐co‐EVGE)] is synthesized by living anionic polymerization. The vinyl moieties of the functional PEO‐based polymer are converted to the hydrogen iodide adduct by photolysis of diphenyliodonium iodide, monitored using NMR spectroscopy. A modified mode of Lewis acid‐catalyzed living cationic polymerization is performed as a “grafting from” method to generate PIBVE segments grafted onto the PEO main chain. Both the intermediates and the final graft copolymers are characterized by gel‐permeation chromato­graphy (GPC) and 1H NMR analysis.

  相似文献   

12.
Lymphomatoid granulomatosis is a rare, diffuse, large B-cell lymphoma that is positive for Epstein-Barr virus. A multiorgan process, it manifests itself chiefly in the lungs but can also affect the skin, nervous system, and kidneys. Cardiac involvement and pericardial effusion are very unusual. We report the case of a 62-year-old man with lymphomatoid granulomatosis involving the heart and lungs. Diagnosis was confirmed with wedge biopsy at pericardiotomy, and the patient was treated with cyclophosphamide, prednisolone, and vincristine. Although the patient was still symptomatic at 6-month follow-up, he was in partial remission with improved functional capacity.  相似文献   
13.

Introduction

Near-infrared diode lasers can be used for several applications, which range from disinfection to smear layer removal in endodontics. This study evaluated the efficacy of agitation of 15% EDTA with an 808-nm diode laser on removal of the smear layer.

Methods

Sixty extracted human maxillary central incisor teeth were instrumented up to ProTaper F4 (Dentsply Maillefer, Ballagues, Switzerland) and then randomly divided into 6 groups (n = 10 for each group) according to the different final irrigating protocols as follows: 5% sodium hypochlorite for 120 seconds performed with the NaviTip (Dentsply Maillefer, Ballaigues, Switzerland) (control group); 15% EDTA for 120 seconds performed with the NaviTip; and agitation of 15% EDTA with an 808-nm diode laser for 10, 20, 30, and 40 seconds. Specimens were observed under a scanning electron microscope, and open dentinal tubules were counted using Adobe Photoshop software (Adobe Systems, San Jose, CA). The data were analyzed with 1-way analysis of variance and Tukey post hoc tests (P = .05).

Results

The number of open dentinal tubules was higher in the middle thirds than in the apical thirds. The differences between the apical and middle thirds were statistically significant (P < .05). Statistically significant differences were also found between the control group and the other groups in both the middle and apical thirds of the root canals (P < .05).

Conclusions

The results indicated that agitation of 15% EDTA with an 808-nm diode laser for 20 seconds was effective in removing the smear layer in the apical thirds of root canals.  相似文献   
14.
15.
16.
17.
PurposeExcision repair cross-complementation group 1 enzyme (ERCC1) plays a key role in the removal of platinum induced DNA adducts and cisplatin resistance. Prognostic role of ERCC1 expression in the neoadjuvant setting in bladder cancer has not been reported before. We evaluated the prognostic role of ERCC1 expression in bladder cancer receiving platinum-based neoadjuvant chemotherapy.Materials and methodsThirty-eight patients with muscle invasive bladder cancer who received neoadjuvant platinum-based chemotherapy were included. Clinical and histopathologic parameters along with immunohistochemical ERCC1 staining were examined and correlated with response rates and survival.ResultsPathologic complete response rates were similar between patients with low and high ERCC1 expression. Median disease-free survival (DFS) was 9.3 vs. 20.5 months (P = 0.186) and median overall survival (OS) was 9.3 vs. 26.7 months (P = 0.058) in patients with high ERCC1 expression compared with those with low expression, respectively. In multivariate Cox regression analysis: pathological complete response (pCR) after chemotherapy (hazard ratio (HR) 0.1, 95% CI 0.012–0.842, P = 0.034) and high ERCC1 expression (HR 3.7, 95% CI 1.2–11.2, P = 0.019) were significantly associated with DFS. Patient age (>60 vs. ≤60 years) (HR 3.4, 95% CI 1.2–9.4, P = 0.018), the presence of pCR (HR 0.11, 95% CI 0.014–0.981, P = 0.048) and high ERCC expression (HR 6.1, 95 CI 1.9–19.9, P = 0.002) were significantly associated with OS.ConclusionsOur results showed that high ERCC1 expression was independently associated with shorter disease-free and overall survival in patients with bladder cancer who received neoadjuvant platinum-based chemotherapy. ERCC1 may represent a potential predictive marker for platinum-based treatment in bladder cancer.  相似文献   
18.
Objectives: This research aimed to evaluate pre-operatively and post-operatively the olfactory function of patients who had undergone surgery in our clinic for chronic nasal blockage via the Connecticut Chemosensory Clinical Research Center (CCCRC) smell test.

Method: Thirty-seven patients (24 females, 13 males) were enrolled in this study. All had undergone surgery in our clinic due to chronic nasal blockage (not for smell dysfunction), having been diagnosed with septal deviation in conjunction with concha bullosa and/or inferior turbinate hypertrophy. This is a prospective study without a control group. The mean age was 33.74?±?8.98 (range =19–54). All of the operations were performed under general anesthesia. CCCRC smell tests were performed on every patient before the operation and at post-operative 1st week, 6th week, 6th month, and 1st year.

Results: In this study, we found that septoplasty, in conjunction with middle concha surgery and/or inferior concha radiofrequency, did not affect the olfactory function negatively.

Conclusion: Although nasal surgery has the potential to affect the smell function negatively, it was found that olfactory function was not affected after the surgery during a considerably long follow-up period. Moreover, an improvement in smell function was detected at post-operative 6th month and 1st year.  相似文献   
19.
The main principle of reconstructive surgery is replacement of the defective tissues with like tissues. A full-thickness defect of the nasal ala should be reconstructed in three layers: innermost mucosal layer, outermost skin, and the cartilage in-between. The aim of this study is to describe a technique for single-stage, three-layer reconstruction of the full-thickness ala nasi defects. This technique was used on three patients with tumors involving the nasal ala. Resulting full-thickness defects are reconstructed with a mucocartilaginous turnover flap planned from the contralateral side. Aesthetically acceptable results are obtained without the compromise of the nasal airway and with minimal donor site morbidity. None of the patients requested a revision operation. In conclusion, this is a novel technique with minimal donor site morbidity and good postoperative results. Moreover, lost tissues are replaced with exactly the same kind of tissues.  相似文献   
20.
Purpose: The purpose of this study is to evaluate the management of limbal stem cell deficiency (LSCD) secondary to chemical ocular burns.

Materials and methods: The charts of 48 eyes of 40 patients with grade 2 or higher chemical injury were evaluated retrospectively. Subjects with follow-up longer than 1 year were included. Medical treatment, surgical correction of abnormalities of ocular adnexial structures, limbal stem cell transplantation from patient’s fellow eye, from living relatives or from cadaveric donor, amniotic membrane transplantation, conjunctival epitheliectomy, chelation with ethylenediaminetetraacetic acid and penetrating keratoplasty were the treatment modalities. Outcome measures were ocular surface stability and corrected distance visual acuity (CDVA). Failure was defined as the appearance of persistent epithelial defect (nonhealing epithelial defect for more than 2 weeks) with progressive corneal conjunctivalization/vascularization and thinning, and also progression of conjunctivalization to the central 6?mm of the cornea in eyes with subsequent keratoplasty.

Results: The mean age of 31 male and 9 female patients were 32.32?±?12.6 years. LSCD was bilateral in 8 cases. The mean follow-up was 77.2?±?35.1 months. The presentations were in acute phase in 37.5%, in subacute phase in 32.5% and in chronic phase in 30% of the patients. Only 13 of 48 (27.1%) eyes obtained sufficient ocular surface stability through medical treatment; however, only 5 of these eyes achieved CDVA of less than 0.7 logMAR. Limbal stem cell transplantation was performed in 26 eyes as conjunctival limbal autograft, living-related conjunctival limbal allograft and keratolimbal allograft or as a combination of these transplantations. At the last visit, 30 eyes (62.5%) had an intact and stable ocular surface. Clear cornea was achieved in 11 (78.6%) of 14 eyes with grade 2 injury, in 9 (60%) of 15 eyes with grade 3 injury, in 5 (50%) of 10 eyes with grade 4 injury, in 1 (16.6%) of 6 eyes with grade 5 injury and in 1 (33.3%) of 3 eyes with grade 6 injury. The CDVA that was 1.66?±?0.99 logMAR initially improved to 0.87?±?0.85 logMAR at the last visit (p?Conclusion: While patients with low-grade chemical injury seem to benefit quite well from the medical treatment, amniotic membrane transplantation, limbal graft transplantation and subsequent keratoplasty; patients with severe injuries seem to be more prone to failure after all of the available treatment modalities.  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