全文获取类型
收费全文 | 40391篇 |
免费 | 3114篇 |
国内免费 | 1071篇 |
专业分类
耳鼻咽喉 | 139篇 |
儿科学 | 1862篇 |
妇产科学 | 256篇 |
基础医学 | 3514篇 |
口腔科学 | 330篇 |
临床医学 | 4384篇 |
内科学 | 11715篇 |
皮肤病学 | 176篇 |
神经病学 | 316篇 |
特种医学 | 2388篇 |
外科学 | 3647篇 |
综合类 | 6888篇 |
现状与发展 | 3篇 |
预防医学 | 2151篇 |
眼科学 | 139篇 |
药学 | 3770篇 |
27篇 | |
中国医学 | 1999篇 |
肿瘤学 | 872篇 |
出版年
2024年 | 43篇 |
2023年 | 648篇 |
2022年 | 1135篇 |
2021年 | 1500篇 |
2020年 | 1589篇 |
2019年 | 1377篇 |
2018年 | 1437篇 |
2017年 | 1455篇 |
2016年 | 1408篇 |
2015年 | 1526篇 |
2014年 | 2741篇 |
2013年 | 2811篇 |
2012年 | 2602篇 |
2011年 | 2691篇 |
2010年 | 2233篇 |
2009年 | 2176篇 |
2008年 | 2223篇 |
2007年 | 2255篇 |
2006年 | 2013篇 |
2005年 | 1708篇 |
2004年 | 1289篇 |
2003年 | 1031篇 |
2002年 | 834篇 |
2001年 | 804篇 |
2000年 | 614篇 |
1999年 | 550篇 |
1998年 | 458篇 |
1997年 | 384篇 |
1996年 | 298篇 |
1995年 | 344篇 |
1994年 | 321篇 |
1993年 | 232篇 |
1992年 | 211篇 |
1991年 | 172篇 |
1990年 | 178篇 |
1989年 | 131篇 |
1988年 | 140篇 |
1987年 | 141篇 |
1986年 | 104篇 |
1985年 | 123篇 |
1984年 | 117篇 |
1983年 | 39篇 |
1982年 | 113篇 |
1981年 | 73篇 |
1980年 | 61篇 |
1979年 | 56篇 |
1978年 | 46篇 |
1977年 | 46篇 |
1976年 | 30篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
目的:探索清肺化痰汤对慢性阻塞性肺疾病(COPD)的治疗作用及其机制研究。方法:应用烟雾吸入联合脂多糖(LPS)灌肺复合素的方法,建立COPD大鼠模型,造模成功后将大鼠随机分为6组,分别为正常组,COPD模型组,清肺化痰汤低、中、高剂量组和氨溴索组。造模28 d后开始给药,清肺化痰汤低、中、高剂量7.5,15,30 g·kg~(-1),氨溴索35 mg·kg~(-1),连续给药14 d。免疫组化和实时荧光定量聚合酶链式反应(Real-time PCR)检测肺组织囊性纤维化跨膜转导调节因子(CFTR)蛋白和mRNA的表达。应用LPS诱导NCI-H292细胞建立黏液高分泌模型,实验分为8组,分别为空白组,LPS组,LPS+10%胎牛血清,LPS+生理血清,LPS+5%含药血清,LPS+10%含药血清,LPS+20%含药血清,LPS+AG490组。免疫荧光、蛋白免疫印迹法(Western blot)和Real-time PCR观察LPS刺激后的NCI-H292细胞中CFTR蛋白和mRNA的表达,Western blot检测LPS刺激后的NCI-H292细胞中Janus激酶2/信号转导与转录激活因子3(JAK2/STAT3)信号通路表达。结果:正常组大鼠肺组织管腔周围有大量棕褐色颗粒,COPD表达升高,与正常组比较,模型组大鼠肺组织管腔周围的棕褐色颗粒极少,COPD表达较低。与正常组比较,COPD模型组大鼠肺组织中CFTR mRNA和蛋白表达明显降低(P0.05);与模型组比较,清肺化痰汤低、中、高剂量组明显升高大鼠肺组织CFTR mRNA和蛋白表达水平(P0.05)。与空白组比较,LPS组NCI-H292细胞CFTR mRNA和蛋白表达显著降低(P0.01),p-JAK2,p-STAT3蛋白表达明显升高(P0.05);与模型组比较,清肺化痰汤5%,10%,20%含药血清组明显升高CFTR mRNA和蛋白表达,明显降低p-JAK2,p-STAT3蛋白表达(P0.05,P0.01)。结论:清肺化痰汤通过抑制JAK2/STAT3通路来上调CFTR治疗COPD。 相似文献
102.
目的探讨血清铁蛋白在慢性肝病显著纤维化和肝硬化中的诊断价值。方法收集来我院诊疗的122例慢性肝病患者资料,均进行肝组织病理学检查,检测患者的肝纤维化4项、肝功能以及血清铁蛋白的水平,以肝穿刺的病理结果作为依据,比较血清铁蛋白与肝纤维化4项、血常规等指标对显著肝纤维化和肝硬化诊断价值的优劣,并采用Logistic回归分析探讨相关影响因素。结果血清铁蛋白、肝纤维化四项指标水平均与肝纤维化程度呈正相关,均随着肝纤维化分期增加而增加,并且在肝硬化时期最高(P<0.05)。对纤维化或肝硬化的可能影响因素进行单因素分析,结果发现血小板透明质酸、层黏蛋白、Ⅳ型胶原、Ⅲ型前胶原、血清铁蛋白等因素与显著纤维化有关;而白细胞计数、血小板、白蛋白、层黏蛋白、Ⅳ型胶原、Ⅲ型前胶原、血清铁蛋白等因素与肝硬化有关。ROC曲线分析血清铁蛋白对显著纤维化的诊断效能,曲线下面积为0.816(0.803~0.910),血清铁蛋白在截点值为138.17 ng/mL时,敏感度为82.0%,特异度为91.2%。ROC曲线分析血清铁蛋白对肝硬化的诊断效能,曲线下面积(AUC)为0.827(0.817~0.846),血清铁蛋白在截点值为160.25 ng/mL时,敏感度为82.4%,特异度为91.5%。结论血清铁蛋白、肝纤维化四项与慢性肝病显著纤维化和肝硬化程度有关,且以上方式简便、创伤性小、可重复性较强,对检测肝纤维化以及肝硬化程度具有良好的提示作用。 相似文献
103.
经皮肺动脉瓣植入术(PPVI)在我国作为一种新兴的技术,开展相对较晚,但随着我国医疗水平的不断提高以及临床对于右心室流出道梗阻的先天性心脏病患者术后出现重度肺动脉瓣反流的不断重视,PPVI在我国得到了飞速发展。近十几年来,欧美国家已在临床成熟应用PPVI,相对于传统外科手术而言其具有微创、可重复性、术后疗效好等优点。现对PPVI在肺动脉瓣反流患者中的临床应用进行叙述。 相似文献
104.
105.
AbstractBackground: This study aims to compare the effectiveness of inhaled prostacyclin or its analoguesversus nitric oxide (NO) in treating pulmonary hypertension (PH) after cardiac or pulmonary surgery remains unclear.Methods: PubMed, Cochrane, and Embase databases were searched for literature published prior to December 2019 using the following keywords: inhaled, nitric oxide, prostacyclin, iloprost, treprostinil, epoprostenol, Tyvaso, flolan, and pulmonary hypertension. Randomized controlled trials and multiple-armed prospective studies that evaluated inhaled NO versus prostacyclin (or analogues) in patients for perioperative and/or postoperative PH after either cardiac or pulmonary surgery were included. Retrospective studies, reviews, letters, comments, editorials, and case reports were excluded.Results: Seven studies with a total of 195 patients were included. No difference in the improvement of mean pulmonary arterial pressure (pooled difference in mean change= ?0.10, 95% CI: ?3.98 to 3.78, p?=?.959) or pulmonary vascular resistance (pooled standardized difference in mean change= ?0.27, 95% CI: ?0.60 to 0.05, p?=?.099) were found between the two treatments. Similarly, no difference was found in other outcomes between the two treatments or subgroup analysis.Conclusions: Inhaled prostacyclin (or analogues) was comparable to inhaled NO in treating PH after cardiac or pulmonary surgery.
- Key messages
This study compared the efficacy of inhaled prostacyclin or its analogues versus inhaled NO to treat PH after surgery. The two types of agent exhibited similar efficacy in managing MPAP, PVR, heart rate, and cardiac output was observed.
Inhaled prostacyclin may serve as an alternative treatment option for PH after cardiac or pulmonary surgery.
106.
《Journal of thoracic oncology》2020,15(1):125-129
IntroductionIn incidence lung cancer screening rounds, new pulmonary nodules are regular findings. They have a higher lung cancer probability than baseline nodules. Previous studies have shown that baseline perifissural nodules (PFNs) represent benign lesions. Whether this is also the case for incident PFNs is unknown. This study evaluated newly detected nodules in the Dutch-Belgian randomized-controlled NELSON study with respect to incidence of fissure-attached nodules, their classification, and lung cancer probability.MethodsWithin the NELSON trial, 7557 participants underwent baseline screening between April 2004 and December 2006. Participants with new nodules detected after baseline were included. Nodules were classified based on location and attachment. Fissure-attached nodules were re-evaluated to be classified as typical, atypical, or non-PFN by two radiologists without knowledge of participant lung cancer status.ResultsOne thousand four hundred eighty-four new nodules were detected in 949 participants (77.4% male, median age 59 years [interquartile range: 55–63 years]) in the second, third, and final NELSON screening round. Based on 2-year follow-up or pathology, 1393 nodules (93.8%) were benign. In total, 97 (6.5%) were fissure-attached, including 10 malignant nodules. None of the new fissure-attached malignant nodules was classified as typical or atypical PFN.ConclusionsIn the NELSON study, 6.5% of incident lung nodules were fissure-attached. None of the lung cancers that originated from a new fissure-attached nodule in the incidence lung cancer screening rounds was classified as a typical or atypical PFN. Our results suggest that also in the case of a new PFN, it is highly unlikely that these PFNs will be diagnosed as lung cancer. 相似文献
107.
《Asian journal of surgery / Asian Surgical Association》2022,45(11):2159-2167
This study aimed to comprehensively identify risk factors for the occurrence of prolonged air leak (PAL) in patients undergoing pulmonary surgery. Studies were retrieved from 3 databases, including PubMed, Web of Science, and EmBase up to 13 May 2020. We performed meta-analysis using Bayesian random effect models through divergence restricting conditional tessellation (DIRECT) algorithm. The effect size was expressed as odds ratio (OR) or mean difference (MD), each with 95% credible interval (CrI). The evidence quality was evaluated. Subgroup analyses and sensitivity analyses were conducted. Thirty-nine studies with 89006 patients were finally included. Pooled PAL incidence was 15%. Of 30 risk factors, 22 were significantly associated with increased PAL incidence. Five risk factors were ultimately selected with high evidence quality: smoking history (OR 1.84, 95%CrI 1.45 to 2.31, P<0.001), preoperative steroid use (OR 1.51, 95%CrI 0.87 to 2.65, P = 0.031), lower ratio of forced expiratory volume in 1 s and forced vital capacity (OR 1.99, 95%CrI 1.22 to 3.33, P = 0.005), non-fissureless technique (OR 2.14, 95%CrI 1.31 to 3.66, P = 0.003), and pathological TNM stage III/IV (OR 1.50, 95%CrI 1.07 to 2.12, P = 0.003). Regarding the negative impact of PAL on the personal cost and postoperative recovery, the verification of previous proposed factors and investigation of recently discovered ones both implied directions for risk stratification and the establishment of an applicable prediction model. 相似文献
108.
目的:了解老年肺纤维化合并肺气肿(CPFE)患者急性加重时下呼吸道病原体分布及其耐药谱。方法入选2013年1月至2014年1月因急性加重在重庆医科大学附属第二医院和重庆市中山医院呼吸科住院的CPFE患者76例,分析痰培养与药敏试验结果。结果76例老年住院患者中,痰培养出88株病原体的患者68例,以革兰阴性菌及真菌为主,检出率位于前6位的病原体分别为鲍氏不动杆菌24株(27.3%)、白假丝酵母18株(20.5%)、肺炎克雷伯菌10株(11.4%)、铜绿假单胞菌8株(9.1%)、嗜麦芽寡养单胞菌6株(6.8%)、阴沟肠杆菌6株(6.8%)。合并两种以上病原体感染的患者26例,对测试抗感染药物存在多药耐药。结论老年CPFE患者急性加重时,机会感染率高且耐药严重,应区分病因、予以合理的抗感染及糖皮质激素等治疗。 相似文献
109.
110.