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   86365篇
  免费   6870篇
  国内免费   1735篇
耳鼻咽喉   734篇
儿科学   1953篇
妇产科学   1187篇
基础医学   3629篇
口腔科学   4533篇
临床医学   8086篇
内科学   10301篇
皮肤病学   1524篇
神经病学   5305篇
特种医学   2075篇
外国民族医学   21篇
外科学   8809篇
综合类   15024篇
现状与发展   8篇
一般理论   6篇
预防医学   6996篇
眼科学   1510篇
药学   8352篇
  158篇
中国医学   8887篇
肿瘤学   5872篇
  2024年   321篇
  2023年   1452篇
  2022年   2591篇
  2021年   3531篇
  2020年   3816篇
  2019年   2902篇
  2018年   2743篇
  2017年   3021篇
  2016年   3272篇
  2015年   3045篇
  2014年   5912篇
  2013年   8069篇
  2012年   5773篇
  2011年   6071篇
  2010年   5115篇
  2009年   4453篇
  2008年   3906篇
  2007年   4145篇
  2006年   3708篇
  2005年   3155篇
  2004年   2637篇
  2003年   2303篇
  2002年   1919篇
  2001年   1549篇
  2000年   1321篇
  1999年   1040篇
  1998年   857篇
  1997年   773篇
  1996年   650篇
  1995年   577篇
  1994年   530篇
  1993年   459篇
  1992年   376篇
  1991年   338篇
  1990年   254篇
  1989年   261篇
  1988年   234篇
  1987年   223篇
  1986年   209篇
  1985年   256篇
  1984年   205篇
  1983年   136篇
  1982年   180篇
  1981年   140篇
  1980年   126篇
  1979年   116篇
  1978年   68篇
  1977年   60篇
  1976年   54篇
  1975年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Problem: Although efficacy studies of opioid maintenance treatment (OMT) have shown evidence of treatment benefits, there is still need for studies on its effectiveness in natural clinical processes. This study investigates the development in health, substance use and social conditions of those who applied for OMT, including those denied access or discharged.

Method: First, persons assessed for admittance in 2005–2011 (n?=?127) were categorized into four trajectory groups based on whether they were admitted or denied (n?=?19), discharged (n?=?31), readmitted (n?=?21) or had been undergoing OMT without interruption (n?=?56). Second, 99 of these, the analytical sample, were interviewed at follow-up using (a) the Addiction Severity Index (ASI) for seven problem-areas and housing, and (b) self-rated change in 11 problem areas. The ASI was compared to baseline interviews after 55 months (mean). Third, outcomes within groups was studied in relation to alternative interventions.

Results: Within the analytical sample, those denied OMT showed no improvements at group level, those discharged had some improvements, more if readmitted than if not and those with uninterrupted OMT showed the most comprehensive improvements. Those outside OMT, denied and discharged, had considerable mortality risks related to ongoing drug use, especially in lack of well-planned alternative interventions.

Conclusion: Improvements strongly relate to access to OMT. This study underscores that access to OMT improves the situation in all areas investigated and decreases the risk for drug-related death. It underscores the importance of two major risk situations, i.e. being denied OMT and being discharged.  相似文献   

2.
目的:探讨老年人桡骨远端C型骨折的手术治疗与非手术治疗的疗效差异,评价两种方法的优缺点。方法回顾性分析2009-12—2011-12收治的老年桡骨远端C型骨折68例,按照治疗方法分为A组(手术组)及B组(非手术组),统计分析两组患者的临床资料。结果 A组33例, B组35例,平均随访21.5个月。两组患者的年龄、骨折类型均无差异(P>0.05);术后影像学指标A组优于B组,骨折愈合时间B组优于A组,治疗成本A组大于B组(P<0.05);Cooney评分早期A组优于B组,1年后两组无差异,两组的并发症无差异(P>0.05)。结论老年人桡骨远端C型骨折手术治疗较非手术治疗可获得更好的复位及早期功能,但远期功能恢复无差异。  相似文献   
3.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
4.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
5.
The Impella 5.0, a percutaneously inserted left ventricular assist device, has been used to support patients who have severe heart failure or who are undergoing high-risk percutaneous coronary intervention. We report our surgical placement of the Impella 5.0, through a graft sewn to the aorta, to unload the left ventricle of a 59-year-old man who was undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy shock. The patient underwent successful placement of a long-term left ventricular assist device before his discharge from the hospital. The versatility of the Impella 5.0 is exemplified in this patient who was successfully bridged to long-term support.  相似文献   
6.
目的:分析糖尿病视网膜病变合并黄斑水肿联合采用激光与复方血栓通胶囊治疗的临床疗效。方法:选取我院2017年1月—2019年1月收治的200例糖尿病视网膜病变合并黄斑水肿患者为研究对象,随机分为两组。对照组单独行激光治疗,观察组于对照组基础上联合复方血栓通胶囊治疗,对比两组临床疗效、治疗前后IL-6(白介素-6)、VEGF(血管内皮生长因子)、NOS(血清一氧化氮合成酶)水平变化情况。结果:对照组总有效率(68.00%,68/100)较观察组总有效率(98.00%,98/100)更高(P<0.05);与对照组对比,观察组治疗后NOS水平更高,IL-6、VEGF水平更低(P<0.05)。结论:糖尿病视网膜病变合并黄斑水肿联合采用激光与复方血栓通胶囊治疗的临床疗效显著,值得推广。  相似文献   
7.
AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer.METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard’s scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ2 and Spearman’s correlation tests were used for the comparison of variables.RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered “responders” to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the “non responders” group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001).CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.  相似文献   
8.
9.
目的总结改良Devine治疗小儿隐匿性阴茎的效果。方法对158例小儿隐匿性阴茎患者采用改良Devine术式治疗,阴茎皮肤完全脱套后,切除发育异常的纤维肉膜组织,阴茎根部皮肤固定成角。结果 158例患儿术后阴茎均显露良好。随访105例,随访2~38个月,105例患儿阴茎均发育正常,效果满意。结论改良Devine术式是治疗小儿隐匿性阴茎的理想术式。该术式操作简单,术后恢复快,并发症少,治疗效果满意。  相似文献   
10.
The aim of this study was to evaluate whether the lesion regression rate (ΔLR) based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria could be used for the prediction of treatment outcome in head and neck squamous cell carcinoma (HNSCC) patients treated with chemoradiotherapy (CRT) compared with FDG PET-CT. A total of 33 patients underwent MRI and PET-CT at pretreatment and at 8 weeks after CRT. We assessed the treatment outcome by analyzing the following parameters: the RECIST criteria, ΔLR, the European Organization for Research and Treatment of Cancer (EORTC) criteria, and pretreatment SUVmax of the primary tumor and node. The correlation between the analysis of the parameters and the results of the long-term follow-up of the patients was determined. The RECIST did not significantly correlate with locoregional control (LRC) or survival. The ΔLR was significantly lower for the lesions with locoregional failure (LRF) than for those with LRC. A threshold ΔLR of 48% revealed a sensitivity of 72.7% and specificity of 77.3% for the prediction of LRF. Progression-free survival (PFS) of patients with ΔLR ≥ 48% was significantly better than that of patients with ΔLR < 48% (P = 0.001), but not overall survival. There was a significant correlation between LRC and the EORTC (P = 0.02). The patients who achieved a complete response by the EORTC criteria showed significantly better PFS and overall survival (P = 0.01 and 0.04, respectively). The ΔLR was inferior to FDG PET-CT with respect to the prediction of patient survival; however, it may be useful for selecting patients in need of more aggressive monitoring after CRT.  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