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   6812篇
  免费   676篇
  国内免费   450篇
耳鼻咽喉   36篇
儿科学   101篇
妇产科学   167篇
基础医学   881篇
口腔科学   123篇
临床医学   879篇
内科学   1190篇
皮肤病学   66篇
神经病学   420篇
特种医学   349篇
外国民族医学   3篇
外科学   673篇
综合类   886篇
现状与发展   1篇
一般理论   2篇
预防医学   336篇
眼科学   145篇
药学   783篇
  5篇
中国医学   295篇
肿瘤学   597篇
  2024年   28篇
  2023年   113篇
  2022年   274篇
  2021年   361篇
  2020年   287篇
  2019年   267篇
  2018年   272篇
  2017年   218篇
  2016年   179篇
  2015年   341篇
  2014年   382篇
  2013年   342篇
  2012年   537篇
  2011年   548篇
  2010年   317篇
  2009年   234篇
  2008年   293篇
  2007年   349篇
  2006年   329篇
  2005年   390篇
  2004年   193篇
  2003年   187篇
  2002年   152篇
  2001年   113篇
  2000年   131篇
  1999年   124篇
  1998年   103篇
  1997年   88篇
  1996年   90篇
  1995年   64篇
  1994年   79篇
  1993年   37篇
  1992年   62篇
  1991年   56篇
  1990年   48篇
  1989年   54篇
  1988年   42篇
  1987年   42篇
  1986年   27篇
  1985年   23篇
  1984年   21篇
  1982年   13篇
  1981年   11篇
  1979年   11篇
  1978年   17篇
  1977年   7篇
  1976年   10篇
  1973年   10篇
  1972年   6篇
  1967年   7篇
排序方式: 共有7938条查询结果,搜索用时 12 毫秒
31.
冷却系统是超导型磁共振正常运行的重要保障,而冷头是磁共振冷却系统的重要组件.本文着重介绍冷头的工作原理、运行方式及其在使用中的日常维护和定期保养.  相似文献   
32.
介绍了基于bq2050电池容量检测电路的设计,实测结果表明此电池容量检测电路设计合理,实用有效,且精度高、体积小、功耗低,适合生命探测仪使用。  相似文献   
33.
We report a case of an assisted pregnancy in an asymptomatic woman who was found to have an extrauterine mass on ultrasound and MRI. This complex mass had equivocal imaging features and was found to be a ruptured ovarian ectopic pregnancy at surgery. This case illustrates that vigilance is required regarding the possibility of coexisting ectopic and intrauterine pregnancy following assisted conception, even in entirely asymptomatic cases.  相似文献   
34.
Axitinib is a potent vascular endothelial growth factor receptor (VEGFR) inhibitor, which has a strong inhibitory effect on the three isoforms of VEGFR 1–3. Having strong therapeutic efficacy, its broad use is limited by its side effects such as hypertension, proteinuria, cardiovascular damage, and liver and kidney dysfunction. Selenium compounds are broadly reported to have a good protective effect on cardiovascular disease, inflammation, infection, and immune function. In this study, a selenium substitute of axitinib was synthesized, and its anti-renal cell carcinoma activity and side effects were investigated. The results of the study indicated that Se-axitinib had potent antitumor activity on renal cell carcinoma (RCC), alleviated vascular hyperpermeability, and also alleviated axitinib-related side effects including hypertension, liver dysfunction and kidney dysfunction significantly. Therefore, we suggest that Se-axitinib could be a solution to the severe side effects of VEGFR inhibitors and provide evidence to improve the outcome of RCC treatment.

Se-axitinib is a selenium substitution of sulfur in axitinib, which reduced the side effect of VEGFR inhibitors and maintained the potent anticancer activity of the original drug.  相似文献   
35.
Endoscopic mucosal resection (EMR) was originally described in 1973 and is currently a popular practice used in treating polyps, small adenomas, and early cancers. Although the safety of EMR has been proven in numerous studies, complications occur occasionally. We report a case in which the patient complained of severe upper abdominal pain and who was diagnosed with acute appendicitis after colorectal EMR. The patient recovered well after surgery. Cautious observation is necessary when resuming oral intake in patients who undergo colorectal EMR and who complain of postoperative abdominal pain. Observation is especially important for patients with a fecalith that may have originally existed in the appendix or in the colon near the appendix.  相似文献   
36.
BackgroundAccumulating data suggest antiviral effects of povidone-iodine against the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. This narrative review aims to examine the antiviral mechanisms of povidone-iodine, efficacy of povidone-iodine against the SARS-CoV-2 virus, and safety of povidone-iodine to human epithelial cells and thyroid function.MethodsWe searched the electronic databases PubMed, Embase, Cochrane Library, ClinicalTrials.gov and World Health Organization’s International Clinical Trials Registry Platform for articles containing the keywords “povidone-iodine”, “SARS-CoV-2” and “COVID-19” from database inception till 3 June 2021.ResultsDespite in vitro data supporting the anti-SARS-CoV-2 effects of povidone-iodine, findings from clinical studies revealed differences in treatment response depending on study settings (healthy vs. hospitalized individuals), treatment target (nasal vs. oral vs. pharynx), method of administration (oral rinse vs. gargle vs. throat spray) and choice of samples used to measure study endpoints (nasopharyngeal vs. saliva). One large-scale clinical trial demonstrated reduction in the incidence of SARS-CoV-2 infection among participants who administered povidone-iodine 3 times daily during an active outbreak. Povidone-iodine is also used to disinfect the oro-pharyngeal space prior to dental or otolaryngology procedures. Although existing data suggest minimal impact of povidone-iodine on thyroid function, high-quality safety data are presently lacking.ConclusionsPovidone-iodine application to the oropharyngeal space could complement existing non-pharmacological interventions to reduce SARS-CoV-2 infection especially in high exposure settings.

Key messages

  • Accumulating data suggest antiviral effects of povidone-iodine against the SARS-CoV-2 virus.
  • Findings from clinical studies reveal differences in treatment response depending on study settings, treatment target, method of administration and choice of samples used to measure study endpoints. One large-scale clinical trial observed reduction in the incidence of SARS-CoV-2 infection among participants who administered povidone-iodine 3 times daily during an active outbreak.
  • Povidone-iodine application to the oropharyngeal space could complement existing non-pharmacological interventions to reduce SARS-CoV-2 infection especially in high exposure settings.
  相似文献   
37.
炙甘草汤含药血清对兔心肌细胞瞬间外向钾电流的影响   总被引:4,自引:0,他引:4  
目的 用血清药理学的方法研究炙甘草汤含药血清对兔心肌细胞瞬间外向钾电流(ho)的影响。方法 进行单个心室肌细胞的分离和膜片钳全细胞记录,将心室肌细胞分为对照组、空白血清组及5%、10%、20%、40%含药血清组,分别以普通细胞外液及加入上述不同浓度血清的细胞外液进行灌流,检测不同浓度含药血清对I10的影响。结果 含药血清可抑制I10,5%、10%、20%、40%含药血清分别将I10峰值(PA/PF)从(16.1±1.4)降至(13.9±1.5)、(11.8±1.9)、(8.3±1.5)、(8.2±1.2),洗脱后其作用可消除。结论 炙甘草汤含药血清可抑制l。,且呈浓度依赖性作用增强,可能是炙甘草汤抗心律失常作用的机理。  相似文献   
38.
39.
Rationale:The spleen is an uncommon metastatic organ for malignant solid tumors because of its special anatomy and microenvironment. Isolated splenic metastasis of endometrial cancer is an extremely rare clinical event, with only 17 cases reported in literature.Patient concerns:We report the case of a 58-year-old woman with abdominal distension and nausea for 7 months who had undergone surgery and chemotherapy for endometrioid adenocarcinoma 12 years previously. A space-occupying lesion in the upper pole of the spleen was observed on an abdominal ultrasound.Diagnosis:The spleen was resected, and splenic metastasis of endometrial adenocarcinoma was histologically confirmed.Interventions:Splenectomy was performed, and no lymph nodes or other metastases were observed. The patient received postoperative chemotherapy with 6 cycles of docetaxel and carboplatin.Outcomes:The patient recovered well 11 months postoperatively, with no evidence of recurrence or metastatic disease.Lesson:Since the time interval between the diagnosis of primary endometrial cancer and splenic metastasis may be very long, it may be necessary to monitor the recurrence of endometrial cancer after primary treatment.  相似文献   
40.
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