全文获取类型
收费全文 | 45421篇 |
免费 | 2744篇 |
国内免费 | 230篇 |
专业分类
耳鼻咽喉 | 546篇 |
儿科学 | 1007篇 |
妇产科学 | 1039篇 |
基础医学 | 5805篇 |
口腔科学 | 1625篇 |
临床医学 | 3514篇 |
内科学 | 11814篇 |
皮肤病学 | 1085篇 |
神经病学 | 3725篇 |
特种医学 | 948篇 |
外科学 | 7497篇 |
综合类 | 303篇 |
一般理论 | 12篇 |
预防医学 | 3062篇 |
眼科学 | 988篇 |
药学 | 2505篇 |
1篇 | |
中国医学 | 160篇 |
肿瘤学 | 2759篇 |
出版年
2023年 | 320篇 |
2022年 | 246篇 |
2021年 | 1431篇 |
2020年 | 795篇 |
2019年 | 1483篇 |
2018年 | 1719篇 |
2017年 | 995篇 |
2016年 | 1058篇 |
2015年 | 1327篇 |
2014年 | 1904篇 |
2013年 | 2342篇 |
2012年 | 3804篇 |
2011年 | 3895篇 |
2010年 | 2184篇 |
2009年 | 1950篇 |
2008年 | 3130篇 |
2007年 | 3225篇 |
2006年 | 2981篇 |
2005年 | 2694篇 |
2004年 | 2405篇 |
2003年 | 2188篇 |
2002年 | 2013篇 |
2001年 | 309篇 |
2000年 | 284篇 |
1999年 | 356篇 |
1998年 | 314篇 |
1997年 | 235篇 |
1996年 | 205篇 |
1995年 | 250篇 |
1994年 | 202篇 |
1993年 | 193篇 |
1992年 | 186篇 |
1991年 | 132篇 |
1990年 | 112篇 |
1989年 | 96篇 |
1988年 | 99篇 |
1987年 | 80篇 |
1986年 | 81篇 |
1985年 | 93篇 |
1984年 | 96篇 |
1983年 | 88篇 |
1982年 | 104篇 |
1981年 | 103篇 |
1980年 | 79篇 |
1979年 | 67篇 |
1978年 | 54篇 |
1977年 | 59篇 |
1975年 | 51篇 |
1974年 | 50篇 |
1973年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
4.
Michala G. Rolver Lya K. K. Holland Muthulakshmi Ponniah Nanditha S. Prasad Jiayi Yao Julie Schnipper Signe Kramer Line Elingaard-Larsen Elena Pedraz-Cuesta Bin Liu Luis A. Pardo Kenji Maeda Albin Sandelin Stine Falsig Pedersen 《International journal of cancer. Journal international du cancer》2023,152(8):1668-1684
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
5.
Natalia P. Schütz Paola Ochoa Patricio Duarte Guillermina Remaggi Sebastián Yantorno Ariel Corzo Soledad Zabaljauregui Claudia Shanley Sergio Lopresti Sergio Orlando Verónica Verri Luis Quiroga Carlos A. García Vanesa Fernández Dorotea Fantl 《Hematological oncology》2020,38(3):363-371
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
6.
Luis Miguel Jiménez Muñoz Indira Sotelo Díaz Carlos Salgado Rohner Gabriela Cáez Ramirez 《Journal of Culinary Science & Technology》2019,17(2):89-102
Lionfish is an invasive and predatory species with low local consumption due to a lack of culinary knowledge of its preparation. A new way to prepare lionfish was proposed to increase variety and provide added value. The aim of this study was to evaluate the effect of high power ultrasound application on the textural properties measured by the texture profile analysis, sensory attributes, and shape preference of surimi patties (rounded and square) made from lionfish. Patties were prepared using lionfish surimi processed with ultrasound (37 kHz; 150 W), sodium citrate (0.3%), sucrose (1%), and salt (2%). Ultrasound exposure increased the hardness of the patties by 35.1%, decreased cohesiveness by 89.7%, and decreased the chewiness by 49.1%. Results show that high power ultrasound showed potential as an environmentally friendly technology to create surimi as a base for patties with sensory and textural appropriateness, increasing the potential culinary applications of lionfish. 相似文献
7.
8.
9.
10.
Milan Milojevic Patrick W. Serruys Joseph F. Sabik David E. Kandzari Erick Schampaert Ad J. van Boven Ferenc Horkay Imre Ungi Samer Mansour Adrian P. Banning David P. Taggart Manel Sabaté Anthony H. Gershlick Andrzej Bochenek Jose Pomar Nicholas J. Lembo Nicolas Noiseux John D. Puskas Arie Pieter Kappetein 《Journal of the American College of Cardiology》2019,73(13):1616-1628