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   54079篇
  免费   3430篇
  国内免费   265篇
耳鼻咽喉   668篇
儿科学   1236篇
妇产科学   1262篇
基础医学   7436篇
口腔科学   1568篇
临床医学   5933篇
内科学   11807篇
皮肤病学   938篇
神经病学   5329篇
特种医学   1942篇
外科学   6852篇
综合类   335篇
一般理论   49篇
预防医学   3807篇
眼科学   832篇
药学   3727篇
  1篇
中国医学   66篇
肿瘤学   3986篇
  2023年   323篇
  2022年   233篇
  2021年   1076篇
  2020年   808篇
  2019年   1074篇
  2018年   1332篇
  2017年   1172篇
  2016年   1357篇
  2015年   1445篇
  2014年   1911篇
  2013年   2731篇
  2012年   4159篇
  2011年   4382篇
  2010年   2573篇
  2009年   2339篇
  2008年   3614篇
  2007年   3896篇
  2006年   3464篇
  2005年   3563篇
  2004年   3283篇
  2003年   3017篇
  2002年   2750篇
  2001年   450篇
  2000年   354篇
  1999年   457篇
  1998年   489篇
  1997年   403篇
  1996年   356篇
  1995年   379篇
  1994年   333篇
  1993年   332篇
  1992年   245篇
  1991年   240篇
  1990年   229篇
  1989年   240篇
  1988年   203篇
  1987年   175篇
  1986年   185篇
  1985年   224篇
  1984年   191篇
  1983年   174篇
  1982年   204篇
  1981年   169篇
  1980年   145篇
  1979年   114篇
  1978年   122篇
  1977年   132篇
  1976年   95篇
  1975年   111篇
  1974年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers.  相似文献   
2.
Wienhold  Jan  Kemper  Ilka  Czaplik  Michael  Follmann  Andreas  Rossaint  Rolf  Derwall  Matthias 《Der Anaesthesist》2023,72(10):697-702
Die Anaesthesiologie - In Deutschland werden pro Jahr 17 Millionen Narkosen und damit auch ungefähr so viele Narkosevorgespräche durchgeführt. Bis dato finden diese praktisch...  相似文献   
3.
Die Anaesthesiologie - Simulationstraining ist für die Notfallmedizin unverzichtbar, insbesondere in Hinsicht auf eine verbesserte Patientensicherheit. Methoden und Technologien umfassen ein...  相似文献   
4.
5.
6.
Die Anaesthesiologie - Phantomschmerzen haben eine hohe Prävalenz nach Majoramputationen und sind mit einer zusätzlichen Einschränkung der Lebensqualität verbunden....  相似文献   
7.
IntroductionThe coronavirus disease 2019 (COVID-19) led to the worldwide closure of dental practices or reduction of dental services. By the end of April 2020, governments and professional organisations were publishing recommendations or guidance for the reopening/restructuring of dental services. The aim of this study was to assess how dental aerosol-generating procedures (AGPs) were defined in international dental guidelines, what mitigation processes were advised, and whether they were linked to COVID-19 epidemiology.MethodsElectronic searches of a broad range of databases, along with grey literature searches, without language restriction were conducted up to 13 July 2020. Recommendations for the use of face masks and fallow times with patients without COVID-19 were assessed against the deaths per 1 million population in the included countries and country income level using Pearson Chi-squared statistics.ResultsSixty-three guidance documents were included. Most (98%) indicated that AGPs can be performed with patients without COVID-19 with caveats, including advice to restrict AGPs where possible, with 21% only recommending AGPs for dental emergencies. Face masks were recommended by most documents (94%), with 91% also specifying the use of goggles or face shields. Fallow periods for patients without COVID-19 were mentioned in 48% of documents, ranging from 2 to 180 minutes. There were no significant differences in recommendations for face masks or fallow time in patients without COVID-19 by country death rate (P = .463 and P = .901) or World Bank status (P = .504 and P = .835). Most documents recommended procedural or environmental mitigations such as preprocedural mouthwash (82%) and general ventilation (52%). Few documents provided underpinning evidence for their recommendations.ConclusionsWhile the amount of high-quality direct evidence related to dentistry and COVID-19 remains limited, it is important to be explicit about the considered judgements for recommendations as well as generate new evidence to face this challenge.  相似文献   
8.
9.
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of...  相似文献   
10.
KRAS oncogene mutations cause sustained signaling through the MAPK pathway. Concurrent inhibition of MEK, EGFR, and HER2 resulted in complete inhibition of tumor growth in KRAS-mutant (KRASm) and PIK3CA wild-type tumors, in vitro and in vivo. In this phase I study, patients with advanced KRASm and PIK3CA wild-type colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and pancreatic cancer, were treated with combined lapatinib and trametinib to assess the recommended phase 2 regimen (RP2R). Patients received escalating doses of continuous or intermittent once daily (QD) orally administered lapatinib and trametinib, starting at 750 mg and 1 mg continuously, respectively. Thirty-four patients (16 CRC, 15 NSCLC, three pancreatic cancers) were enrolled across six dose levels and eight patients experienced dose-limiting toxicities, including grade 3 diarrhea (n = 2), rash (n = 2), nausea (n = 1), multiple grade 2 toxicities (n = 1), and aspartate aminotransferase elevation (n = 1), resulting in the inability to receive 75% of planned doses (n = 2) or treatment delay (n = 2). The RP2R with continuous dosing was 750 mg lapatinib QD plus 1 mg trametinib QD and with intermittent dosing 750 mg lapatinib QD and trametinib 1.5 mg QD 5 days on/2 days off. Regression of target lesions was seen in 6 of the 24 patients evaluable for response, with one confirmed partial response in NSCLC. Pharmacokinetic results were as expected. Lapatinib and trametinib could be combined in an intermittent dosing schedule in patients with manageable toxicity. Preliminary signs of anti-tumor activity in NSCLC have been observed and pharmacodynamic target engagement was demonstrated.  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