全文获取类型
收费全文 | 111421篇 |
免费 | 9973篇 |
国内免费 | 5536篇 |
专业分类
耳鼻咽喉 | 1688篇 |
儿科学 | 1317篇 |
妇产科学 | 1198篇 |
基础医学 | 15203篇 |
口腔科学 | 2253篇 |
临床医学 | 12528篇 |
内科学 | 18794篇 |
皮肤病学 | 2391篇 |
神经病学 | 6977篇 |
特种医学 | 5620篇 |
外国民族医学 | 27篇 |
外科学 | 12245篇 |
综合类 | 11442篇 |
现状与发展 | 20篇 |
一般理论 | 16篇 |
预防医学 | 6314篇 |
眼科学 | 2584篇 |
药学 | 11458篇 |
55篇 | |
中国医学 | 5119篇 |
肿瘤学 | 9681篇 |
出版年
2024年 | 387篇 |
2023年 | 1652篇 |
2022年 | 4078篇 |
2021年 | 5629篇 |
2020年 | 3834篇 |
2019年 | 3817篇 |
2018年 | 4032篇 |
2017年 | 3587篇 |
2016年 | 3940篇 |
2015年 | 5549篇 |
2014年 | 6289篇 |
2013年 | 6459篇 |
2012年 | 9143篇 |
2011年 | 9297篇 |
2010年 | 5909篇 |
2009年 | 4645篇 |
2008年 | 5999篇 |
2007年 | 5737篇 |
2006年 | 5316篇 |
2005年 | 5034篇 |
2004年 | 3808篇 |
2003年 | 3679篇 |
2002年 | 3078篇 |
2001年 | 2370篇 |
2000年 | 2162篇 |
1999年 | 1986篇 |
1998年 | 1099篇 |
1997年 | 1047篇 |
1996年 | 798篇 |
1995年 | 696篇 |
1994年 | 636篇 |
1993年 | 409篇 |
1992年 | 611篇 |
1991年 | 544篇 |
1990年 | 510篇 |
1989年 | 438篇 |
1988年 | 385篇 |
1987年 | 333篇 |
1986年 | 302篇 |
1985年 | 220篇 |
1984年 | 141篇 |
1983年 | 114篇 |
1982年 | 64篇 |
1981年 | 78篇 |
1979年 | 106篇 |
1978年 | 63篇 |
1975年 | 73篇 |
1974年 | 59篇 |
1972年 | 63篇 |
1971年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Hyun Jong Choi Jong Ho Moon Yun Nah Lee Hyun Su Kim Ji Su Ha Tae Hoon Lee Sang‐Woo Cha Young Deok Cho Sang‐Heum Park 《Digestive endoscopy》2015,27(7):772-775
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS. 相似文献
2.
目的对比可弯曲胸腔镜和硬质胸腔镜在不明原因胸腔积液诊断中的准确性和安全性。方法采用前瞻性随机对照研究,连续筛选四川大学华西医院2012年3月至2014年3月期间不明原因胸腔积液住院患者,患者年龄18~75岁。经知情同意后,患者随机进入可弯曲胸腔镜组或硬质胸腔镜组进行检查。结果可弯曲胸腔镜组入组49例患者,硬质胸腔镜组入组48例患者。两组共有44例患者通过胸腔镜检查确诊为恶性疾病,48例确诊为良性疾病。两组诊断不明原因胸腔积液总体准确性分别为93.9%和95.8%,可弯曲胸腔镜组诊断肿瘤的敏感性为96.0%,硬质胸腔镜组诊断肿瘤的敏感性为95.2%,两组诊断肿瘤的特异性均为100.0%,两组之间差异无统计学意义。两种胸腔镜技术并发症多数轻微,患者均耐受良好。结论对于不明原因胸腔积液,可弯曲胸腔镜诊断的准确性与硬质胸腔镜相当。尽管可弯曲胸腔镜取材组织小,但是通过多点多次取材,所获得的组织标本能满足病理科医生进行包括免疫组织化学检测在内的疾病诊断。 相似文献
3.
4.
Ho-Chul Jung Sung-Bin Chon Won Sup Oh Dong-Hyun Lee Ho-Jin Lee 《The American journal of tropical medicine and hygiene》2015,92(2):256-261
Scrub typhus usually presents as acute undifferentiated fever. This cross-sectional study included adult patients presenting with acute undifferentiated fever defined as any febrile illness for ≤ 14 days without evidence of localized infection. Scrub typhus cases were defined by an antibody titer of a ≥ fourfold increase in paired sera, a ≥ 1:160 in a single serum using indirect immunofluorescence assay, or a positive result of the immunochromatographic test. Multiple regression analysis identified predictors associated with scrub typhus to develop a prediction rule. Of 250 cases with known etiology of acute undifferentiated fever, influenza (28.0%), hepatitis A (25.2%), and scrub typhus (16.4%) were major causes. A prediction rule for identifying suspected cases of scrub typhus consisted of age ≥ 65 years (two points), recent fieldwork/outdoor activities (one point), onset of illness during an outbreak period (two points), myalgia (one point), and eschar (two points). The c statistic was 0.977 (95% confidence interval = 0.960–0.994). At a cutoff value ≥ 4, the sensitivity and specificity were 92.7% (79.0–98.1%) and 90.9% (86.0–94.3%), respectively. Scrub typhus, the third leading cause of acute undifferentiated fever in our region, can be identified early using the prediction rule. 相似文献
5.
6.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis 下载免费PDF全文
7.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
8.
9.
The cingulum, connecting the orbitofrontal cortex to the medial temporal lobe, involves in diverse cognition functions including attention, memory, and motivation. To investigate the relationship between the cingulum injury and cognitive impairment in patients with chronic mild traumatic brain injury, we evaluated the integrity between the anterior cingulum and the basal forebrain using diffusion tensor tractography in 73 patients with chronic mild traumatic brain injury(39 males, 34 females, age 43.29 ± 11.42 years) and40 healthy controls(22 males, 18 females, age 40.11 ± 16.81 years). The patients were divided into three subgroups based on the integrity between the anterior cingulum and the basal forebrain on diffusion tensor tractography: subgroup A(n = 19 patients)-both sides of the anterior cingulum were intact; subgroup B(n= 36 patients)-either side of the anterior cingulum was intact; and subgroup C(18 patients)-both sides of the anterior cingulum were discontinued. There were significant differences in total Memory Assessment Scale score between subgroups A and B and between subgroups A and C. There were no significant differences in diffusion tensor tractography parameters(fractional anisotropy, apparent diffusion coefficient, and fiber volume) between patients and controls. These findings suggest that the integrity between the anterior cingulum and the basal forebrain, but not diffusion tensor tractography parameter, can be used to predict the cognitive function of patients with chronic mild traumatic brain injury. This study was approved by Yeungnam University Hospital Institutional Review Board(approval No. YUMC-2014-01-425-010) on August 16, 2017. 相似文献
10.