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   691702篇
  免费   313039篇
  国内免费   61877篇
耳鼻咽喉   6251篇
儿科学   8971篇
妇产科学   9525篇
基础医学   141938篇
口腔科学   9981篇
临床医学   120475篇
内科学   161473篇
皮肤病学   9323篇
神经病学   44877篇
特种医学   24152篇
外国民族医学   272篇
外科学   87964篇
综合类   121643篇
现状与发展   101篇
一般理论   70篇
预防医学   67838篇
眼科学   28256篇
药学   101944篇
  435篇
中国医学   68009篇
肿瘤学   53120篇
  2024年   6368篇
  2023年   8756篇
  2022年   20003篇
  2021年   25047篇
  2020年   22222篇
  2019年   26928篇
  2018年   28234篇
  2017年   27291篇
  2016年   25263篇
  2015年   31199篇
  2014年   35509篇
  2013年   33381篇
  2012年   44048篇
  2011年   49325篇
  2010年   37678篇
  2009年   40795篇
  2008年   34740篇
  2007年   31986篇
  2006年   31537篇
  2005年   32015篇
  2004年   24945篇
  2003年   22805篇
  2002年   21046篇
  2001年   21899篇
  2000年   18366篇
  1999年   24300篇
  1998年   20935篇
  1997年   20831篇
  1996年   20060篇
  1995年   20020篇
  1994年   18989篇
  1993年   16235篇
  1992年   16683篇
  1991年   15305篇
  1990年   13860篇
  1989年   13273篇
  1988年   12458篇
  1987年   11719篇
  1986年   10835篇
  1985年   9665篇
  1984年   7271篇
  1983年   7075篇
  1982年   7887篇
  1981年   7350篇
  1980年   6995篇
  1979年   6915篇
  1978年   5943篇
  1977年   6213篇
  1976年   5830篇
  1975年   5552篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
目的:探讨PDCA在缩短肺功能患者等候时间中的作用。方法:通过调取2018年3月19~4月19日肺功能工作量与2017年同期对比,查找患者等候时间长的原因。结果:通过完善绩效考核体系、设定基础工作量、加强科室内部协调等措施,有效缩短了患者等候时间,提高了工作效率。结论:通过PDCA循环,不仅缩短了患者等候时间和呼吸科平均住院日,还提高了患者满意度,使科室内部合作更加协调与紧密。  相似文献   
4.

Background

Programmed death ligand-1 (PD-L1) is a potential predictive biomarker for immunotherapy in several malignancies. However, the expression level and clinical significance of PD-L1 in von Hippel–Lindau (VHL)-associated hereditary clear-cell renal cell carcinoma (ccRCC) remain unclear.

Patients and Methods

Surgical specimens were recruited from 129 patients with sporadic ccRCC and 26 patients with VHL-associated hereditary ccRCC. The PD-L1 expression level was assessed using immunohistochemistry. Correlations between PD-L1 expression and clinicopathological features were analyzed.

Results

In sporadic ccRCC, the positive expression rate of PD-L1 was 47.3% (61/129). Positive PD-L1 expression was correlated with advanced tumor T stage (P = .011), higher Fuhrman nuclear grade (P = .022), poor disease-free survival (P = .037), and sex (P = .025). In the VHL-associated hereditary ccRCC, positive PD-L1 expression rate was 34.6% (9/26), lower than that in sporadic ccRCC. Positive PD-L1 was correlated with higher Fuhrman nuclear grade (P = .008), but not with sex, age, tumor stage, or the onset age of VHL-associated tumors.

Conclusion

Positive PD-L1 expression was correlated with the aggressive clinicopathological features in sporadic and VHL-associated hereditary ccRCC. Whether PD-L1 expression level in ccRCC is related to the effectiveness of programmed death-1/PD-L1 checkpoint inhibitor immunotherapy needs to be further investigated.  相似文献   
5.
Objective: To reflectively look at the present methods by which the clinical competence of 5th-year medical students (i.e. interns) in Sun Yat-Sen University (SYSU) are assessed upon finishing internship rotation in internal medicine (IM).

Methods: Current procedures for the competence assessment of end-of-rotation IM interns in the First Affiliated Hospital of SYSU were reviewed, along with a point-by-point appraisal based on the PROFILE approach to structured assessment, and, whenever possible, suggestions for future improvement.

Results and discussions: On a scale of 1–10, with 10 being the best or the most ideal, our marks for current methods to assess end-of-rotation IM interns in terms of being Programmatic, Real-World, Outcome-based, Formative, Impactful, Learner-engaged, and Evaluation-guaranteed were 7, 9, 3, 4, 6, 8, and 1, respectively. The strengths, weaknesses as well as potential solutions in each of the seven aspects are also discussed separately.

Conclusions: Current assessment program for IM internship is strong in being programmatic, real-world, educationally impactful and learner engaged, and has room for further improvement in its time-based arrangements, relative shortage of feedback provision, as well as a systematic lack of quality control measures.  相似文献   

6.
目的:对氯氮平片在帕金森病(Parkinson’s disease,PD)合并精神障碍辅助治疗中的应用价值予以探讨。方法:选取50例我院2013年1月1日—2019年6月30日接诊的PD合并精神障碍患者进行研究,按照随机数表法分为对照组和观察组。对照组用多巴丝肼,观察组联合氯氮平片,对比治疗效果。结果:观察组疾病治疗总有效率96.00%(24/25)高于对照组68.00%(17/25),差异有统计学意义(P<0.05),不良反应发生率8.00%(2/25)与对照组20.00%(5/25)差异无统计学意义(P>0.05);观察组UPDRD评分、VGI-S评分和BPRS评分明显低于对照组,差异有统计学意义(P<0.05)。结论:氯氮平片辅助治疗PD合并精神障碍患者,既可提高临床疗效,也不会增加用药后不良反应,安全性高,值得推广。  相似文献   
7.
Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer-related death due to the failure of traditional therapies. In the present study, we attempted to construct a lncRNA-miRNA-mRNA network which may modulate PDAC cell proliferation and Gemcitabine-induced cell apoptosis starting from CDK14, a new member of the CDK family and an oncogene in many cancers. Based on TCGA data, a significant positive correlation was observed between lncRNA MSC-AS1 and CDK14. Moreover, MSC-AS1 expression was upregulated in PDAC tissues. Higher MSC-AS1 expression was correlated with poorer prognosis in patients with PDAC. MSC-AS1 knockdown in Panc-1 and BxPC-3 cells significantly inhibited the cell proliferation. Moreover, miR-29b-3p, which has been reported to act as a tumor suppressor, was predicted to bind to both MSC-AS1 and CDK14. Contrary to MSC-AS1, higher miR-29b-3p expression was correlated to better prognosis in patients with PDAC. In both PDAC cell lines, miR-29b-3p negatively regulated MSC-AS1 and CDK14. As confirmed using luciferase reporter gene and RIP assays, MSC-AS1 served as a ceRNA for miR-29b-3p to counteract miR-29b-mediated CDK14 repression. MSC-AS1 knockdown inhibited CDK14 protein levels and PDAC proliferation and enhanced gemcitabine-induced cell death and apoptosis while miR-29b-3p inhibition exerted an opposing effect; the effect of MSC-AS1 knockdown was partially attenuated by miR-29b-3p inhibition. Taken together, we demonstrated that MSC-AS1/miR-29b-3p axis modulates the cell proliferation and GEM-induced cell apoptosis in PDAC cell lines through CDK14. We provided a novel experimental basis for PDAC treatment from the perspective of lncRNA-miRNA-mRNA network.  相似文献   
8.
9.
Purpose: Child injuries are a global public health problem and injury surveillance systems (ISS) can be beneficial by providing timely data. However, ISS implementation has challenges. Opinions of stakeholders of ISS implementation barriers and facilitators are a good source to understand this phenomenon. The aim of this study is to investigate barriers and facilitators of implementing ISS in Iran. Methods: This is a qualitative study. Data were gathered through interviews with 14 experts in the field of child injury and prevention from Iranian Ministry of Health and Medical Education (MOHME), medical universities, pediatrics hospitals, general hospitals and health houses during January 2017 to September 2017. Data collection and analysis continued until data saturation. Data were analyzed using content analysis through identifying meaning units. Results: Barriers were classified in three main categories and nine subcategories including management barriers (including performance, coordination and cooperation, supervision and attitude), weakness in data capture and usage (including data collection, data recording and data dissemination) and resource limitation (including human and financial resources). Facilitators identified in three areas of policy making (including empowerment and attitude), management (including organization, function and cooperation and coordination) and data recording and usage (including data collection/distribution and data recording). Conclusion: The most important barrier is lack of national policy in child injury prevention. The most important facilitator is improving MOHME function through passing supportive regulations. Effective data usage and dissemination of information to those requiring data for policy making can help reduce child injuries. Coalition of stakeholders helps overcome existing barriers.  相似文献   
10.
Objective To analyze the pathological characteristics and prognostic factors of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods A retrospective analysis of AAV patients with renal biopsy results admitted to Kidney Disease Center of the First Affiliated Hospital from January 2004 to February 2017 was performed. The patients were divided into 4 types according to Berden classification, and their clinical, pathological characteristics and prognosis were compared. The survival curves of each type of patients were plotted by Kaplan-Meier method, and the difference of survival curves was compared using Log-rank test. With entering the maintenance dialysis as the endpoint, Cox regression was used to analyze the prognostic factors. Results A total of 175 patients with AAV, including 59 cases (33.7%) of focal type, 39 cases (22.3%) of crescent type, 32 cases (18.3%) of sclerosis type, 45 cases (25.7%) of mixed type. The basal serum creatinine levels in crescent type group and sclerosis type group were significantly higher than those in the focal type group or mixed type group (all P<0.05), and loop necrosis rate in sclerosis type group was significantly lower than chat in the focal type group or crescent type group (both P<0.05). The median follow-up period was 11.8 (0.5-86.7) months. The event-free survival rates were 83.1%, 77.8%, 64.1% and 50.0% in the focal type, mixed type, crescent type and sclerotic type groups (Log-rank χ2=11.537, P=0.009). Cox regression analysis showed higher parathyroid hormone (HR=1.013, 95%CI 1.007-1.019, P<0.001), glomerular sclerosis ≥50% (HR=10.532, 95%CI 2.903-38.203, P<0.001) were independent risk factors for AAV patients entering maintenance dialysis, and higher estimated glomerular filtration rate (HR=0.943, 95%CI 0.896-0.993, P=0.025) was protective factor. Conclusion The prognosis of AAV renal damage is worsened according to focal, mixed, crescent and sclerosis types. Lower estimated glomerular filtration rate, higher parathyroid hormone and glomerular sclerosis ≥50% are independent risk factors for AAV patients entering maintenance dialysis.  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