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   94827篇
  免费   45298篇
  国内免费   151篇
耳鼻咽喉   1740篇
儿科学   4664篇
妇产科学   1111篇
基础医学   17899篇
口腔科学   5948篇
临床医学   13830篇
内科学   28627篇
皮肤病学   8000篇
神经病学   14829篇
特种医学   2576篇
外科学   17451篇
综合类   173篇
一般理论   24篇
预防医学   5789篇
眼科学   1620篇
药学   6661篇
中国医学   1108篇
肿瘤学   8226篇
  2023年   197篇
  2022年   169篇
  2021年   2026篇
  2020年   5370篇
  2019年   11472篇
  2018年   10888篇
  2017年   11829篇
  2016年   12477篇
  2015年   12453篇
  2014年   12698篇
  2013年   13415篇
  2012年   6020篇
  2011年   6000篇
  2010年   10017篇
  2009年   6236篇
  2008年   3636篇
  2007年   2542篇
  2006年   2444篇
  2005年   2043篇
  2004年   1941篇
  2003年   1790篇
  2002年   1722篇
  2001年   652篇
  2000年   460篇
  1999年   182篇
  1998年   162篇
  1997年   135篇
  1996年   119篇
  1995年   130篇
  1994年   106篇
  1993年   88篇
  1992年   85篇
  1991年   57篇
  1990年   54篇
  1989年   46篇
  1988年   45篇
  1987年   36篇
  1986年   26篇
  1985年   45篇
  1984年   41篇
  1983年   43篇
  1982年   46篇
  1981年   44篇
  1980年   41篇
  1979年   19篇
  1978年   25篇
  1977年   25篇
  1975年   22篇
  1974年   21篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
1.
This paper examines the propagation of COVID-19 across the Spanish provinces and assesses the effectiveness of the Spanish lockdown of the population implemented on March 14, 2020 in order to battle this pandemic. To achieve these objectives, a standard spatial econometric model used in economics is adapted to resemble the popular reproduction models employed in the epidemiological literature. In addition, we introduce a counterfactual exercise that allows us to examine the Gross domestic product (GDP) gains of bringing forward the date of the Spanish Lockdown. We find that the number of COVID-19 cases would have been reduced by 70.4% in the absence of spatial propagation between the Spanish provinces. We also determine that the lockdown prevented the propagation of the virus within and between provinces. As such, the Spanish lockdown reduced the number of potential COVID-19 cases by 82.8%. However, the number of coronavirus cases would have been reduced by an additional 11.6% if the lockdown had been brought forward to March 7, 2020. Finally, an earlier lockdown would have saved approximately 26,900,000,000 euros.  相似文献   
2.
3.
The mechanisms linking tumor microenvironment acidosis to disease progression are not understood. Here, we used mammary, pancreatic, and colon cancer cells to show that adaptation to growth at an extracellular pH (pHe) mimicking acidic tumor niches is associated with upregulated net acid extrusion capacity and elevated intracellular pH at physiological pHe, but not at acidic pHe. Using metabolic profiling, shotgun lipidomics, imaging and biochemical analyses, we show that the acid adaptation-induced phenotype is characterized by a shift toward oxidative metabolism, increased lipid droplet-, triacylglycerol-, peroxisome content and mitochondrial hyperfusion. Peroxisome proliferator-activated receptor-α (PPARA, PPARα) expression and activity are upregulated, at least in part by increased fatty acid uptake. PPARα upregulates genes driving increased mitochondrial and peroxisomal mass and β-oxidation capacity, including mitochondrial lipid import proteins CPT1A, CPT2 and SLC25A20, electron transport chain components, peroxisomal proteins PEX11A and ACOX1, and thioredoxin-interacting protein (TXNIP), a negative regulator of glycolysis. This endows acid-adapted cancer cells with increased capacity for utilizing fatty acids for metabolic needs, while limiting glycolysis. As a consequence, the acid-adapted cells exhibit increased sensitivity to PPARα inhibition. We conclude that PPARα is a key upstream regulator of metabolic changes favoring cancer cell survival in acidic tumor niches.  相似文献   
4.
For advanced and metastatic urothelial carcinomas (UCs), platinum (preferably cisplatin)‐based chemotherapy has been the standard treatment for many years. However, many patients are ineligible for cisplatin‐based chemotherapy because of poor performance status and/or other age‐related conditions. At the other end of the spectrum, patients with localized non‐muscle–invasive bladder cancer who are unresponsive to intravesical Bacillus Calmette‐Guérin (BCG) treatment often face radical cystectomy as the only option. In recent years, the application of immunotherapy in the form of immune‐checkpoint inhibitors has provided viable alternatives in the second‐line postplatinum and first‐line cisplatin‐ineligible settings. Recent and ongoing clinical trials are also assessing the safety and efficacy of immunotherapy for neoadjuvant and adjuvant uses before/after cystectomy, for BCG‐unresponsive cases, and for combination treatments that include the newer indoleamine 2,3‐dioxygenase‐1 inhibitors and/or BCG. This review summarizes recent developments in immunotherapy for UCs.  相似文献   
5.
6.
7.
8.
Rosmarinus species are aromatic plants that mainly grow in the Mediterranean region. They are widely used in folk medicine, food, and flavor industries and represent a valuable source of biologically active compounds (e.g., terpenoids, flavonoids, and phenolic acids). The extraction of rosemary essential oil is being done using three main methods: carbon dioxide supercritical extraction, steam distillation, and hydrodistillation. Furthermore, interesting antioxidant, antibacterial, antifungal, antileishmanial, anthelmintic, anticancer, anti‐inflammatory, antidepressant, and antiamnesic effects have also been broadly recognized for rosemary plant extracts. Thus the present review summarized data on economically important Rosmarinus officinalis species, including isolation, extraction techniques, chemical composition, pharmaceutical, and food applications.  相似文献   
9.
Data about treatment outcomes and toxicity in Latin America are scarce. There are differences with central countries based on access to healthcare system and socioeconomic status. Argentinean Society of Hematology recommends bortezomib-based triplets for induction treatment of transplant eligible newly diagnosed multiple myeloma patients. Most common options are CyBorD (cyclophosphamide, bortezomib and dexamethasone) and VTD (bortezomib, thalidomide and dexamethasone). Main goal of our retrospective, multicentric study was to compare very good partial response rate (VGPR) or better after induction treatment in a real-world setting in Argentina. Secondary objectives included comparison of complete response (CR) post-induction and after bone marrow transplantation, grade 3-4 adverse events (AEs), progression-free survival (PFS) and overall survival (OS). Three hundred twenty-two patients were included (median age at diagnosis: 57 years; 52% male; 28% had ISS3; 14% with high-risk cytogenetics; median follow up: 34 months). CyBorD was indicated in 74% and 26% received VTD. In VTD arm, 72.62% of patients achieved at least VGPR vs 53.36% receiving CyBorD (odds ratio, OR: 1.96 [95% confidence interval, CI: 1.08-3.57; P = .026] after adjusting by age, ISS [International Staging System], lactate dehydrogenase levels (LDH) and cytogenetic risk. Difference in VGPR was 19.26% (95% CI: 15-24). CR rate were 35.92% (VTD) vs 22.55% (CyBorD) (adjusted OR: 2.13 [95% CI: 1.12-4.05]). Difference in CR was 13.37% (95% CI: 9.6-17.53). Adverse events (AEs) were more common with VTD (69.05% vs 55.46% for CyBorD; P = .030), especially grade 3-4 neuropathy (P = .005) and thrombosis (P = .001). Thromboprophylaxis was inadequate in 20.24% of patients. Hematological AEs were more common with CyBorD, especially thrombocytopenia (P = .017). PFS and OS at 24 months were not different between treatments. In this real-world setting, VTD was associated with better CR and VGPR than CyBorD. Nevertheless, CyBorD continues to be the preferred induction regimen in Argentina, based on safety profile. Frontline autologous stem cell transplantation improves quality of responses, especially in countries with limited access to new drugs.  相似文献   
10.
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