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   7118篇
  免费   329篇
  国内免费   129篇
耳鼻咽喉   122篇
儿科学   117篇
妇产科学   94篇
基础医学   1056篇
口腔科学   137篇
临床医学   591篇
内科学   1459篇
皮肤病学   260篇
神经病学   408篇
特种医学   715篇
外科学   906篇
综合类   56篇
预防医学   227篇
眼科学   212篇
药学   597篇
  3篇
中国医学   107篇
肿瘤学   509篇
  2024年   26篇
  2023年   48篇
  2022年   172篇
  2021年   247篇
  2020年   146篇
  2019年   207篇
  2018年   204篇
  2017年   209篇
  2016年   272篇
  2015年   354篇
  2014年   437篇
  2013年   458篇
  2012年   601篇
  2011年   569篇
  2010年   403篇
  2009年   395篇
  2008年   388篇
  2007年   415篇
  2006年   281篇
  2005年   286篇
  2004年   209篇
  2003年   172篇
  2002年   178篇
  2001年   80篇
  2000年   62篇
  1999年   58篇
  1998年   92篇
  1997年   103篇
  1996年   67篇
  1995年   63篇
  1994年   47篇
  1993年   51篇
  1992年   22篇
  1991年   14篇
  1990年   19篇
  1989年   34篇
  1988年   26篇
  1987年   31篇
  1986年   14篇
  1985年   19篇
  1984年   12篇
  1983年   14篇
  1982年   11篇
  1981年   9篇
  1980年   9篇
  1978年   5篇
  1977年   11篇
  1976年   6篇
  1968年   2篇
  1967年   3篇
排序方式: 共有7576条查询结果,搜索用时 15 毫秒
61.
OBJECTIVE: To evaluate expression of cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LO) associated with interleukin (IL)-4 promoter polymorphism -590 in nasal polyp tissues. STUDY DESIGN AND SETTING: A prospective controlled study. A venous blood sample was taken to determine the genotype in 61 nasal polyp subjects. The C-590T variant was determined by the polymerase chain reaction-restriction fragment length polymorphism method. The expression of 5-LO and COX-2 was determined with immunohistochemical staining in 37 nasal polyp tissues associated with genotype. RESULTS: The genotype frequencies at position -590 of the IL-4 gene in the patients with nasal polyp were C/C (8.20%), C/T (40.98%), and T/T (50.82%). There was no significantly increased expression of COX-2 among genotypes. The 5-LO expression was significantly increased in C/C compared with C/T and T/T. CONCLUSION: We suggested that the IL-4 promoter polymorphism -590 C/C is associated with the expression of 5-LO in the patients with nasal polyp.  相似文献   
62.
63.

Objective

Although partial nephrectomy (PN) is the standard treatment for localized clinical T1a renal cell carcinoma (RCC), treatment of larger renal tumors is controversial. We evaluated the oncological outcomes and perioperative complications after radical and PN for RCC ≥4 cm.

Patients and methods

We retrospectively analyzed the data of 2,373 patients surgically treated for nonmetastatic RCC with clinical T1b or T2 (≥4 cm). The propensity scores for surgery type were calculated, and the partial group was matched to the radical group in a 1:3 ratio. The oncological outcomes were compared using Kaplan-Meier analysis and multivariate Cox regression models were used to identify the independent predictors of progression-free, cancer-specific, and overall survival.

Results

All differences in preoperative clinical characteristics disappeared after matching. There were no significant differences in progression-free, cancer-specific, or overall survival between the partial and radical groups in the matched cohort. The patients’ age, tumor size, cellular grade, and pathologic stage were independent predictors for all 3 survival outcomes. However, early complications (<30 d postoperative) were significantly more common in the partial group (P<0.001). In a subgroup analysis of the patients with clinical T2 stage, there were no significant differences in all 3 survival outcomes.

Conclusions

The partial and radical nephrectomy groups had equivalent oncological outcomes. Although the early complication rate was significantly higher after PN, it should be considered as a valuable treatment option even in patients with clinical T1b or higher RCC.  相似文献   
64.
Plastic surgeons commonly encounter patients with facial lacerations and/or abrasions in the emergency room. If they are properly treated, facial wounds generally heal well without complications. However, infection can sometimes cause delayed wound healing. We performed wound culture for the early detection of infection and to promote the healing of infected facial wounds. We included 5033 patients with facial wounds who visited the emergency room of Kangnam Sacred Heart Hospital between January 2018 and February 2021. Among them, 104 patients underwent wound culture. We analysed the pathogens isolated and the patients' age, sex, wound site, mechanism of injury, wound healing time, time from injury to culture, time to culture results, and dressing methods used. Pathogens were isolated in slightly less than half of the patients (38.46%); among them, Staphylococcus epidermidis was the most common (47.5%). Methicillin-resistant coagulase-negative staphylococci were isolated in six (15%) patients. Patients with complicated wounds had a longer mean wound healing time (10.83 ± 5.91 days) than those with non-complicated wounds (6.06 ± 1.68 days). Wound culture of complicated facial wounds resulted in the isolation of various types of pathogens, including antibiotic-resistant bacteria and fungi. We recommend the use of wound culture for early detection of infection to prevent delayed wound healing.  相似文献   
65.
BACKGROUND: Anastomosis leakage is a major complication of rectal surgery. The aim of this study was to identify risk factors for anastomotic leakage after low anterior resection (LAR) in rectal cancer patients and study its impact on long-term prognosis and disease-free survival and overall survival in rectal cancer patients. METHODS: Consecutive patients who underwent rectal resection with primary anastomosis below the pelvic peritoneal reflexion for rectal cancer between October 1996 to February 2006 were included. RESULTS: Anastomosis leakage after LAR occurred in 51 patients (4.0%). The median time to leakage was 4 days (range = 2-30 days). In univariate analysis, gender, level of anastomosis less than 4 cm, preoperative concomitant chemoradiation (CCRT), and length of operation greater than 120 min were significantly associated with anastomosis leakage. In a multivariate analysis, gender (p = 0.041; relative risk = 2.007; 95% CI = 1.030-3.912) and preoperative CCRT (p = 0.003; relative risk = 2.861; 95% CI = 1.417-5.778) were identified as independent prognostic factors. The overall survival of the nonleakage group and the leakage group was 80.2% and 64.9%, respectively (p = 0.170). The 5-year disease-free survival rates were not significantly different between the nonleakage and leakage groups (78.1% vs. 65.9%, p = 0.166). CONCLUSIONS: The incidence of anastomotic leakage after low anterior resection is relatively low. Male gender and preoperative CCRT were associated with increased risk for anastomotic leakage after rectal cancer surgery. No effect of anastomosis leakage on local recurrence was found in this series.  相似文献   
66.
Background: Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of death from cancer in Korea. PDAC is difficult to diagnose at an early stage and even more difficult to cure. Thus, there is an urgent need to identify molecular targets for early diagnosis and effective treatment. The objectives of this study were to identify differentially expressed biomarker proteins of PDAC using proteomic analysis, to validate the identified biomarker proteins associated with carcinogenesis using western blot analysis and to evaluate clinical factors influencing expression of candidate biomarker proteins. Methods: In the present study, we carried out proteomic analysis in 10 pairs of PDAC specimens with matching adjacent normal tissues to clarify the different patterns of protein expression. The proteins were separated by high‐resolution 2‐D polyacrylamide gel electrophoresis (2D PAGE) and the differentially expressed proteins were identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Differential expression of candidate biomarker proteins associated with carcinogenesis was further validated using western blot analysis. Standard statistical analysis was carried out in an attempt to establish a correlation between clinical variables and expression of candidate biomarker proteins. Results: Analysis of PDAC and the adjacent normal tissues showed reproducibly similar proteomic patterns for each group. Approximately 700 spots each were seen by silver‐stained gels from both PDAC and normal tissues. Differentially expressed protein spots were gel digested and identified by MALDI‐TOF MS. Twenty‐five proteins were identified, of which five proteins (galectin‐1, enolase‐2, α‐1‐antitrypsin, N‐myc interactor, peroxiredoxin‐4) were previously reported as being differentially expressed either at the mRNA level or protein level in human cancer. The five proteins were selected for candidate biomarker proteins related to carcinogenesis. These proteins were further validated by western blot analysis. Among the candidate biomarker proteins, galectin‐1 expression was highly correlated to histology (P = 0.019), T stage (P = 0.047), N stage (P = 0.033) and American Joint Committee on Cancer stage (P = 0.011). Conclusion: Differentially expressed 25 proteins in PDAC were identified using proteomic analysis and five proteins related to carcinogenesis were validated by western blot analysis. galectin‐1 expression was highly correlated to tumour histology and stage.  相似文献   
67.
Laparoscopic mini-gastric bypass surgery is a safe and simple surgical intervention for treating morbid obesity and diabetes mellitus and is now being performed more frequently. Radiologists must be critical in their postoperative evaluation of these patients. In this pictorial review, we explain and illustrate the surgical technique, normal postoperative anatomy, and associated complications as seen on imaging examinations, including fluoroscopy and computed tomography.  相似文献   
68.
Comprehensive aortic root and valve repair (CARVAR) surgery using specially designed aortic rings was introduced as a new surgical technique for aortic valve disease. We present five consecutive cases of iatrogenic coronary ostial stenosis after CARVAR surgery in patients with aortic stenosis. The preoperative coronary angiography confirmed that all the patients had normal coronary arteries. They underwent aortic valvuloplasty by aortic leaflet extension and insertion of specially designed inner and outer rings at the level of the sinotubular junction. Within 6 months after surgery, all the patients complained of resting chest pain and dyspnea with changes of electrocardiography. Repeated coronary angiography demonstrated right coronary artery (RCA) ostial stenosis in one patient and left main (LM) ostial stenosis in the other four patients. Intravascular ultrasonography demonstrated severe ostial stenosis and extensive echogenic tissue in the extravascular area. Four patients with LM ostial disease successfully underwent coronary bypass graft surgery, and percutaneous coronary intervention with stenting was performed in one case of RCA ostial stenosis. Because the mechanism of this complication is not fully confirmed, more clinical study is required to confirm the safety issues of CARVAR surgery.  相似文献   
69.
70.
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