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   91769篇
  免费   7932篇
  国内免费   4661篇
耳鼻咽喉   2180篇
儿科学   308篇
妇产科学   4097篇
基础医学   5852篇
口腔科学   847篇
临床医学   10115篇
内科学   6798篇
皮肤病学   400篇
神经病学   1429篇
特种医学   5161篇
外国民族医学   78篇
外科学   17204篇
综合类   16780篇
现状与发展   11篇
预防医学   2811篇
眼科学   242篇
药学   3882篇
  30篇
中国医学   1225篇
肿瘤学   24912篇
  2024年   183篇
  2023年   953篇
  2022年   1964篇
  2021年   2658篇
  2020年   2537篇
  2019年   2183篇
  2018年   2011篇
  2017年   2613篇
  2016年   3281篇
  2015年   2962篇
  2014年   5666篇
  2013年   4882篇
  2012年   5945篇
  2011年   6628篇
  2010年   5711篇
  2009年   5494篇
  2008年   5354篇
  2007年   5957篇
  2006年   5623篇
  2005年   5304篇
  2004年   4142篇
  2003年   3704篇
  2002年   3110篇
  2001年   2978篇
  2000年   2352篇
  1999年   1803篇
  1998年   1570篇
  1997年   1378篇
  1996年   912篇
  1995年   782篇
  1994年   702篇
  1993年   411篇
  1992年   378篇
  1991年   315篇
  1990年   291篇
  1989年   254篇
  1988年   252篇
  1987年   203篇
  1986年   199篇
  1985年   160篇
  1984年   109篇
  1983年   77篇
  1982年   101篇
  1981年   71篇
  1980年   64篇
  1979年   37篇
  1978年   35篇
  1977年   21篇
  1976年   18篇
  1975年   9篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
31.

Background

Partial nephrectomy (PN) is generally favored for cT1 tumors over radical nephrectomy (RN) when technically feasible. However, it can be unclear whether the additional risks of PN are worth the magnitude of renal function benefit.

Objective

To develop preoperative tools to predict long-term estimated glomerular filtration rate (eGFR) beyond 30 d following PN and RN, separately.

Design, setting, and participants

In this retrospective cohort study, patients who underwent RN or PN for a single nonmetastatic renal tumor between 1997 and 2014 at our institution were identified. Exclusion criteria were venous tumor thrombus and preoperative eGFR <15 ml/min/1.73 m2.

Intervention

RN and PN.

Outcome measurements and statistical analysis

Hierarchical generalized linear mixed-effect models with backward selection of candidate preoperative features were used to predict long-term eGFR following RN and PN, separately. Predictive ability was summarized using marginal RGLMM2, which ranges from 0 to 1, with higher values indicating increased predictive ability.

Results and limitations

The analysis included 1152 patients (13 206 eGFR observations) who underwent RN and 1920 patients (18 652 eGFR observations) who underwent PN, with mean preoperative eGFRs of 66 ml/min/1.73 m2 (standard deviation [SD] = 18) and 72 ml/min/1.73 m2 (SD = 20), respectively. The model to predict eGFR after RN included age, diabetes, preoperative eGFR, preoperative proteinuria, tumor size, time from surgery, and an interaction between time from surgery and age (marginal RGLMM2=0.41). The model to predict eGFR after PN included age, presence of a solitary kidney, diabetes, hypertension, preoperative eGFR, preoperative proteinuria, surgical approach, time from surgery, and interaction terms between time from surgery and age, diabetes, preoperative eGFR, and preoperative proteinuria (marginal RGLMM2). Limitations include the lack of data on renal tumor complexity and the single-center design; generalizability needs to be confirmed in external cohorts.

Conclusions

We developed preoperative tools to predict renal function outcomes following RN and PN. Pending validation, these tools should be helpful for patient counseling and clinical decision-making.

Patient summary

We developed models to predict kidney function outcomes after partial and radical nephrectomy based on preoperative features. This should help clinicians during patient counseling and decision-making in the management of kidney tumors.  相似文献   
32.
总结了全国著名骨伤专家梁铁民教授的学术思想和正骨经验,简述了梁老生平。梁老学术思想表现在突出整体观念,主张辨证施术;注重调理气血,强调药物接续;重视望问切触量法五诊结合等三个方面。对于梁老正骨经验先进行了综合论述,进一步佐证其学术思想;后分别从小儿桡骨头半脱位、颈椎错位、胸腰椎小关节错位、肋骨骨折等梁老研究较深入和比较擅长的几个方面进行了阐述。特别是颈椎错位这种高难度高风险的手法操作,体现出梁老高超的手法技艺。  相似文献   
33.
SEPT9是13个Septin同源基因家族之一,参与调控众多过程,包括细胞分裂、细胞极化、细胞迁移以及线粒体分裂等。研究表明在众多肿瘤中,SEPT9都发挥着作用,尤其在结直肠肿瘤研究领域,外周血SEPT9基因甲基化检测更是研究热点,其检测的敏感度和特异度相对于其他糖蛋白肿瘤标志物、粪便隐血试验和粪便免疫化学测试等更具有优势,相对于结直肠镜等侵入性检查更节约成本,同时有着更好的依从性。本文对SEPT9的功能、与结直肠癌之间的关系以及对结直肠肿瘤的筛查及诊断价值做一综述。  相似文献   
34.
35.
《Clinical lung cancer》2020,21(2):160-170
IntroductionPulmonary carcinosarcoma (PC) is a rare malignant neoplasm composed of epithelial and mesenchymal components. It accounts for < 1% of thoracic cancers and is not fully understood. This study examined Surveillance, Epidemiology, and End Results (SEER) data to describe demographic and clinical characteristics of patients with PC and assessed survival outcomes by treatment modality and stage.Patients and MethodsSEER data were reviewed to identify patients diagnosed with primary PC (1973-2012). Overall survival (OS) and disease-specific survival (DSS) were analyzed by univariate/multivariable Cox proportional hazards models and Kaplan-Meier methods.ResultsA total of 411 patients were included. Median age was 67 (range, 24-96) years. Disease stage at the time of initial diagnosis was known for 74.7% of the identified patients (307/411). Of these patients, 23.1% had localized disease. Survival was significantly better for patients with localized disease (OS: 31 vs. 6 months, P < .001; DSS: 54 vs. 8 months, P < .001). Additionally, patients who received surgery alone had significantly improved OS (20 months; P < .001) and DSS (32 months; P < .001) compared to patients who received combined surgery and radiotherapy (OS: 7 months; DSS: 8 months) or radiotherapy alone (OS: 4 months; DSS: 4 months).ConclusionTreatment with surgery alone resulted in superior survival outcomes compared to other treatment modality combinations, regardless of patient age and disease stage. Within the limitations of this study, providers may wish to consider these findings when devising patient treatment plans.  相似文献   
36.
IntroductionAdenoid cystic carcinoma is the most frequent malignant tumor of the submandibular gland and the minor salivary glands. It is a malignant neoplasm that, despite its slow growth, shows an unfavorable prognosis.ObjectivesThe aim of this study was to perform a systematic review of the literature on Adenoid cystic carcinoma in the head and neck region and its clinicopathological characteristics, with emphasis on the perineural invasion capacity of the tumor.MethodsA systematic search of articles published between January 2000 and January 2014 was performed in the PubMed/MEDLINE, SciELO, Science Direct, and Scopus databases.ResultsNine articles were selected for this systematic review. These demonstrated that the female gender was more often affected and that malignant tumors showed a high rate of distant metastasis, recurrence, and a low survival rate. The presence of perineural invasion ranged from 29.4% to 62.5% and was associated with local tumor recurrence.ConclusionAdenoid cystic carcinoma is commonly characterized by the presence of pain, high rate of recurrence, metastasis, and a low survival rate. Reporting studies with patient follow-up is of utmost importance for a better clinical-pathological understanding and to improve the prognosis of this pathology.  相似文献   
37.
38.
目的:研究右美托咪定在宫颈癌根治术后镇痛及术后快速康复中的临床应用效果。方法:将2015年7月至2018年7月在本院行宫颈癌根治术的86例患者随机分为对照组和观察组各43例。对照组术后镇痛采用舒芬太尼和格拉司琼,观察组术后镇痛加用右美托咪定。采用视觉模拟评分法(VAS)评价患者术后1 h、6 h、12 h、24 h、48 h疼痛情况,采用Ramesay评分法评价患者不同时间点镇静状况,记录并比较两组患者不同时间点收缩压、舒张压、心率及呼吸频率变化,比较两组患者不良反应发生情况。结果:观察组患者术后6 h、12 h、24 h、48 h VAS评分均明显低于对照组(P<0.05),Ramesay评分均明显高于对照组(P<0.05);观察组和对照组患者术后不同时间点呼吸频率比较,差异无统计学意义,但术后6 h、12 h、24 h观察组患者收缩压、心率均明显低于对照组(P<0.05),术后1 h、6 h观察组患者舒张压明显低于对照组(P<0.05);观察组患者恶心呕吐、高血压发生率较对照组明显减低。结论:右美托咪定用于宫颈癌根治术后镇痛,可以提高镇痛镇静效果,稳定患者血流动力学,有助于术后快速康复。  相似文献   
39.
40.
目的探讨多原发结直肠癌的临床特征和预后。方法回顾性分析南京医科大学第一附属医院2013年1月至2018年12月收治的42例多原发结直肠癌患者的临床资料,对其临床病理特征、诊治及预后进行总结。结果符合多原发结直肠癌诊断的患者42例,占同期收治的所有结直肠癌患者的1.20%(42/3499),病理类型以腺癌为主。其中,同时性多原发癌32例,年龄38~86岁,中位年龄66岁,共发现73处结直肠癌灶,多位于近端结肠、乙状结肠及直肠;共检出淋巴结527枚,阳性10枚(1.9%),淋巴结阳性患者占同时性多原发癌的37.5%(12/32);27例为双原发癌,3例为三原发癌,2例为五原发癌;1、3年总生存率分别为83.75%和74.38%。异时性多原发癌10例,年龄33~86岁,第一癌多位于直肠和乙状结肠区域,第二癌多位于升结肠区域;共检出淋巴结276枚,阳性率12.3%(34枚),1、3年总生存率分别为100.00%和66.67%。结论多原发结直肠癌在临床上不少见,其分布有一定规律。临床中应引起重视,提高早期诊断率。应早期手术治疗以提高患者的生存率。  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