全文获取类型
收费全文 | 273044篇 |
免费 | 25074篇 |
国内免费 | 6662篇 |
专业分类
耳鼻咽喉 | 3371篇 |
儿科学 | 5345篇 |
妇产科学 | 3794篇 |
基础医学 | 20427篇 |
口腔科学 | 7655篇 |
临床医学 | 24372篇 |
内科学 | 27006篇 |
皮肤病学 | 3492篇 |
神经病学 | 12539篇 |
特种医学 | 6267篇 |
外国民族医学 | 18篇 |
外科学 | 21864篇 |
综合类 | 41165篇 |
现状与发展 | 14篇 |
一般理论 | 27篇 |
预防医学 | 35124篇 |
眼科学 | 2608篇 |
药学 | 48227篇 |
361篇 | |
中国医学 | 28481篇 |
肿瘤学 | 12623篇 |
出版年
2024年 | 917篇 |
2023年 | 4986篇 |
2022年 | 9114篇 |
2021年 | 12977篇 |
2020年 | 12280篇 |
2019年 | 13654篇 |
2018年 | 12427篇 |
2017年 | 11227篇 |
2016年 | 10214篇 |
2015年 | 9760篇 |
2014年 | 18274篇 |
2013年 | 21497篇 |
2012年 | 16912篇 |
2011年 | 17892篇 |
2010年 | 14351篇 |
2009年 | 12493篇 |
2008年 | 11665篇 |
2007年 | 11815篇 |
2006年 | 10136篇 |
2005年 | 8751篇 |
2004年 | 7331篇 |
2003年 | 6551篇 |
2002年 | 5046篇 |
2001年 | 4393篇 |
2000年 | 3725篇 |
1999年 | 3075篇 |
1998年 | 2569篇 |
1997年 | 2308篇 |
1996年 | 1898篇 |
1995年 | 1802篇 |
1994年 | 1614篇 |
1993年 | 1390篇 |
1992年 | 1377篇 |
1991年 | 1208篇 |
1990年 | 1032篇 |
1989年 | 953篇 |
1988年 | 913篇 |
1987年 | 825篇 |
1986年 | 725篇 |
1985年 | 1996篇 |
1984年 | 2228篇 |
1983年 | 1431篇 |
1982年 | 1837篇 |
1981年 | 1284篇 |
1980年 | 1080篇 |
1979年 | 974篇 |
1978年 | 818篇 |
1977年 | 603篇 |
1976年 | 748篇 |
1975年 | 524篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
71.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS. 相似文献
72.
73.
Cristiano Colalto 《Drug development research》2020,81(8):950-968
COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19. 相似文献
74.
《Archives of Cardiovascular Diseases》2022,115(10):505-513
Central illustration: cumulative major adverse cardiac events (MACE) and bioresorbable vascular scaffold (BVS) thrombosis rates after 1, 2, 3, 4 and 5 years. 相似文献
75.
Yesim Aydinok 《ISBT科学丛刊》2020,15(1):102-109
Lifetime red cell concentrate (RCC) transfusions still account for significant iron overload‐related morbidity and mortality despite chelation therapy in thalassaemia. The cumulative risk of transfusion‐transmitted infections is substantial for thalassaemia patients. Pathogen reduction technologies for RCC may imply a proactive approach against new/re‐emerging pathogens and may be an ultimate safeguard for transfusion safety in the developing countries. Red cell alloimmunization may become a significant clinical challenge in thalassaemia. The availability of high‐throughput molecular blood group antigen typing in the donors may allow perfect match transfusion, beyond ABO‐D and CEK antigen‐matched transfusions. Allogeneic stem cell transplantation (A‐SCT) is the only available curative therapy in thalassaemia, but carries a substantial risk of serious adverse events and mortality. Gene addition therapy for correction of the α‐globin chain imbalance overcomes the problems of donor availability and immunological complications of A‐SCT. Gene editing by either gene disruption or correction emerged as a potential alternative to gene addition therapy in beta‐thalassaemia. A new era of novel therapeutics targeting α/β imbalance, ineffective erythropoiesis or iron dysregulation is unfolding in thalassaemia management, and a number of those now have agents in preclinical and clinical development. Hydroxyurea (HU) may improve globin chain imbalance and be beneficial for reducing or omitting transfusion requirement. Ruxolitinib has allowed steady decrease in spleen volume that may serve for avoiding splenectomy in beta‐thalassaemia. Luspatercept may restore normal erythroid differentiation and improve anaemia. Hepcidin mimetics or TMPRSS6 inhibitors may modulate ineffective erythropoiesis by iron restriction and improve anaemia and organ iron loading. 相似文献
76.
《European journal of medical genetics》2020,63(9):103981
Congenital diarrhea and enteropathies (CODEs) are a group of monogenic disorders that often present with severe diarrhea in the first weeks of life. Enteric anendocrinosis (EA), an extremely rare cause of CODE, is characterized by a marked reduction of intestinal enteroendocrine cells (EC). EA is associated with recessively inherited variants in Neurogenin-3 (NEUROG3) gene. Here we investigate a case of a male infant who presented with mysterious severe malabsorptive diarrhea since birth. Thorough clinical assessments and laboratory tests were successful to exclude the majority of differential diagnosis categories. However, the patient's diagnosis was not established until the genetic test using whole-exome sequencing (WES) was performed. We identified a novel homozygous missense disease-causing variant (DCV) in NEUROG3 (c.413C>G, p.Thr138Arg). Moreover, molecular dynamic simulation analysis showed that (p.Thr138Arg) led to a global change of the NEUROG3 orientation affecting its DNA binding capacity. To the best of our knowledge, this is the first time to apply WES to reach a differential diagnosis of patients with CODEs. Our study not only expands our knowledge about NEUROG3 variants and their clinical consequences but also proves that WES is a very effective tool for the diagnosis of CODEs. This might be of value in early diagnosis of diseases and prenatal CODEs detection. 相似文献
77.
78.
Hsiao-Hsuan Kuo Ran Fan Nina Dvorina Andres Chiesa-Vottero William M. Baldwin III 《Journal of the American Society of Nephrology : JASN》2015,26(4):855-863
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses. 相似文献
79.
80.
【目的】 值此《中国科技期刊研究》创刊30周年之际,思考科研评价体系的改变给中文科技期刊带来的影响,为中文期刊探寻发展路径。【方法】 结合对中文科技期刊困境的研究,提出应对策略。【结果】 近期国家陆续出台的纠偏评价导向的政策文件,为中文科技期刊既带来了发展机遇,也提出了挑战。【结论】 在重构符合中文科技期刊发展特点的评价体系的基础上,中文科技期刊应明确目标定位,面向国家需求,提升知识服务能力,建立品牌特色。 相似文献