全文获取类型
收费全文 | 104744篇 |
免费 | 8845篇 |
国内免费 | 1997篇 |
专业分类
耳鼻咽喉 | 1148篇 |
儿科学 | 2769篇 |
妇产科学 | 3038篇 |
基础医学 | 4399篇 |
口腔科学 | 4866篇 |
临床医学 | 9894篇 |
内科学 | 12380篇 |
皮肤病学 | 1795篇 |
神经病学 | 7344篇 |
特种医学 | 2351篇 |
外国民族医学 | 25篇 |
外科学 | 13587篇 |
综合类 | 16882篇 |
现状与发展 | 8篇 |
一般理论 | 5篇 |
预防医学 | 7558篇 |
眼科学 | 1840篇 |
药学 | 9607篇 |
172篇 | |
中国医学 | 9017篇 |
肿瘤学 | 6901篇 |
出版年
2024年 | 110篇 |
2023年 | 1816篇 |
2022年 | 2492篇 |
2021年 | 4345篇 |
2020年 | 4837篇 |
2019年 | 4023篇 |
2018年 | 3776篇 |
2017年 | 3981篇 |
2016年 | 4217篇 |
2015年 | 3858篇 |
2014年 | 7612篇 |
2013年 | 9933篇 |
2012年 | 6975篇 |
2011年 | 7285篇 |
2010年 | 6112篇 |
2009年 | 5401篇 |
2008年 | 4866篇 |
2007年 | 4982篇 |
2006年 | 4481篇 |
2005年 | 3805篇 |
2004年 | 3194篇 |
2003年 | 2752篇 |
2002年 | 2302篇 |
2001年 | 1897篇 |
2000年 | 1567篇 |
1999年 | 1211篇 |
1998年 | 950篇 |
1997年 | 796篇 |
1996年 | 716篇 |
1995年 | 650篇 |
1994年 | 590篇 |
1993年 | 517篇 |
1992年 | 419篇 |
1991年 | 395篇 |
1990年 | 268篇 |
1989年 | 294篇 |
1988年 | 246篇 |
1987年 | 225篇 |
1986年 | 214篇 |
1985年 | 266篇 |
1984年 | 215篇 |
1983年 | 143篇 |
1982年 | 179篇 |
1981年 | 140篇 |
1980年 | 124篇 |
1979年 | 118篇 |
1978年 | 64篇 |
1977年 | 60篇 |
1976年 | 52篇 |
1975年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
胚胎植入是一个复杂且受到高度调控的过程,需要囊胚与母体子宫内膜的发育精确同步。胞饮突作为表达于子宫内膜上的一种特殊膜状突起,随月经周期变化表现为不同形态,可分为发育期、成熟期及退化期。目前已有一系列研究证实,胞饮突的数量、覆盖面积及发育阶段等在预测不孕女性种植窗及评估子宫内膜容受性中具有临床价值。胞饮突评分较高、覆盖面积较广且成熟期胞饮突占比较高的女性妊娠结局更佳。其机制可能包括胞饮突通过调节宫腔内容物影响子宫内膜容受性、通过表达植入相关蛋白参与囊胚-子宫内膜相互作用等。然而,对胞饮突精准且客观的评估手段仍待进一步探索,胞饮突评估子宫内膜容受性的精确度也待进一步验证。 相似文献
52.
目的:探讨结扎速血管闭合切割系统(LigaSure vessel sealing system, LVSS)在巨大神经纤维瘤手术中的应用效果。方法:选取2013年10月至2020年5月行巨大神经纤维瘤手术的患者22例纳入本研究。传统手术组12例采用常规缝扎电凝止血手术方式,LigaSure组10例采用LigaSure血管闭合切割的手术方式,对比两组患者切除瘤体大小、手术时间、术中出血量、术后引流量、术后拔管时间及术后并发症情况。结果:两组间患者的一般资料具有可比性。LigaSure组术中出血量、术后引流量、术后拔管时间均较传统手术组显著降低(P<0.05)。两组间切除瘤体大小、手术时间及术前术后血红蛋白差值无统计学差异。传统手术组出现1例术后皮下积液,予再次引流后伤口愈合良好。结论:LigaSure在手术治疗巨大神经纤维瘤方面的应用安全有效,能显著地减少出血量,简化手术操作,缩短术后恢复时间,值得在临床上进一步推广。 相似文献
53.
《Journal of vascular and interventional radiology : JVIR》2022,33(3):249-254.e1
An ovine iliac vein thrombosis model was devised to test a wall-contacting rotational thrombectomy device. Thrombosis was successfully induced in 9 sheep with an average clot length of 31 mm ± 12 and >60% vessel occlusion on angiography. The thrombus was subsequently removed, maintaining normal intraoperative pulmonary arterial pressure (5.9 mm Hg ± 3.6) and complete distal reperfusion after thrombectomy. Additionally, the sheep were without signs of vascular trauma or embolic complications on gross necropsy and histopathologic analysis. The findings from this study support the use of an ovine iliac deep vein thrombosis model for testing of a lower extremity thrombectomy device. 相似文献
54.
Wattana Leowattana Tawithep Leowattana Pathomthep Leowattana 《World Journal of Clinical Cases》2022,10(34):12470-12483
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered a widespread outbreak since December 2019. The SARS-CoV-2 infection-related illness has been dubbed the coronavirus disease 2019 (COVID-19) by the World Health Organization. Asymptomatic and subclinical infections, a severe hyper-inflammatory state, and mortality are all examples of clinical signs. After attaching to the angiotensin converting enzyme 2 (ACE2) receptor, the SARS-CoV-2 virus can enter cells through membrane fusion and endocytosis. In addition to enabling viruses to cling to target cells, the connection between the spike protein (S-protein) of SARS-CoV-2 and ACE2 may potentially impair the functionality of ACE2. Blood pressure is controlled by ACE2, which catalyzes the hydrolysis of the active vasoconstrictor octapeptide angiotensin (Ang) II to the heptapeptide Ang-(1-7) and free L-Phe. Additionally, Ang I can be broken down by ACE2 into Ang-(1-9) and metabolized into Ang-(1-7). Numerous studies have demonstrated that circulating ACE2 (cACE2) and Ang-(1-7) have the ability to restore myocardial damage in a variety of cardiovascular diseases and have anti-inflammatory, antioxidant, anti-apoptotic, and anti-cardiomyocyte fibrosis actions. There have been some suggestions for raising ACE2 expression in COVID-19 patients, which might be used as a target for the creation of novel treatment therapies. With regard to this, SARS-CoV-2 is neutralized by soluble recombinant human ACE2 (hrsACE2), which binds the viral S-protein and reduces damage to a variety of organs, including the heart, kidneys, and lungs, by lowering Ang II concentrations and enhancing conversion to Ang-(1-7). This review aims to investigate how the presence of SARS-CoV-2 and cACE2 are related. Additionally, there will be discussion of a number of potential therapeutic approaches to tip the ACE/ACE-2 balance in favor of the ACE-2/Ang-(1-7) axis. 相似文献
55.
56.
目的:研究痛经的中医药辨治规律。方法:检索国家知识基础设施数据库(CNKI)1988—2019年应用中药治疗痛经的相关文献,采用Medcase Ver38诊籍中医师工作室-名老中医经验传承辅助平台,运用文本解析对临床医案进行研究。结果:研究文献131篇,医案104则,涉及病例128次,332诊次,涉及症状92条,病机33条,舌象27条,脉象17条,药物249种。结论:中医药治疗痛经的特异症状为“经行腹痛”,可见症为“夹血块、月经色暗、手足冰冷、经期腰酸”,相关舌脉为“舌质暗红,苔薄白”“脉沉细弦”,核心病机为“瘀血阻滞”,常用治法为“行气化瘀,活血止痛”,常用药物为“当归、白芍、甘草、延胡索、川芎”。 相似文献
57.
Derek K. Chu Romina Brignardello-Petersen Gordon H. Guyatt Cristian Ricci Jon Genuneit 《Pediatric allergy and immunology》2022,33(1):e13609
Network meta-analyses (NMAs) simultaneously estimate the effects of multiple possible treatment options for a given clinical presentation. For allergists to benefit optimally from NMAs, they must understand the process and be able to interpret the results. Through a worked example published in Pediatric Allergy and Immunology, we summarize how to identify credible NMAs and interpret them with a focus on recent innovations in the GRADE approach (Grading of Recommendations Assessment, Development, and Evaluation). NMAs build on traditional systematic reviews and meta-analyses that consider only direct paired comparisons by including indirect evidence, thus allowing the simultaneous assessment of the relative effect of all pairs of competing alternatives. Our framework informs clinicians of how to identify credible NMAs and address the certainty of the evidence. Trustworthy NMAs fill a critical gap in providing key inferences using direct and indirect evidence to inform clinical decision making when faced with more than two competing courses of treatment options. This document will help allergists to identify trustworthy NMAs to enhance patient care. 相似文献
58.
59.
Biaoming Xu Yu Chen Mingjing Peng Jin Hai Zheng Chaohui Zuo 《International journal of cancer. Journal international du cancer》2023,152(2):110-122
Pancreatic cancer (PC) is a cancer of the digestive system, and pancreatic ductal adenocarcinoma (PDAC) accounts for approximately 90% of all PC cases. Exosomes derived from PDAC (PDAC-exosomes) promote PDAC development and metastasis. Exosomes are nanoscale vesicles secreted by most cells, which can carry biologically active molecules and mediate communication and cargo transportation among cells. Recent studies have focused on transforming exosomes into good drug delivery systems (DDSs) to improve the clinical treatment of PDAC. This review considers PDAC as the main research object to introduce the role of PDAC-exosomes in PDAC development and metastasis. This review focuses on the following two themes: (a) the great potential of PDAC-exosomes as new diagnostic markers for PDAC, and (b) the transformation of exosomes into potential DDSs. 相似文献
60.
《Journal of vascular and interventional radiology : JVIR》2022,33(10):1199-1206
PurposeTo compare the technical success of antegrade uteral stent (AUS) and retrograde ureteral stent (RUS) placements in patients with malignant ureteral obstruction (MUO) and to determine the predictors of technical failure of RUS.Materials and MethodsThis study retrospectively included 61 AUS placements (44 patients) performed under fluoroscopic guidance and 76 RUS placements (55 patients) performed under cystoscopic guidance in patients with MUO from January 2019 to December 2020. Technical success rates of the 2 techniques were compared using inverse probability of treatment weighting (IPTW) analysis. Logistic regression was used to identify predictive factors for technical failures.ResultsTechnical success was achieved in 98.4% of the AUS group and 47.4% of the RUS group. After stabilized IPTW, the technical success rate was higher in the AUS group than in the RUS group (adjusted risk difference, 49.4%; 95% confidence interval [CI], 35.4%–63.1%). The independent predictors for technical failure of the RUS procedure were age of ≥65 years (odds ratio [OR], 5.56; 95% CI, 1.73–21.27), ureteral orifice invasion (OR, 4.21; 95% CI, 1.46–13.46), and extrinsic cancer (OR, 15.58; 95% CI, 2.92–111.81).ConclusionsThe technical success rate of AUS placement was higher than that of RUS placement in patients with MUO. RUS failure was associated with age of ≥65 years, cancer with ureteral orifice invasion, and extrinsic ureteral obstruction. 相似文献