首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   172101篇
  免费   16340篇
  国内免费   10439篇
耳鼻咽喉   1573篇
儿科学   2989篇
妇产科学   2553篇
基础医学   13472篇
口腔科学   5907篇
临床医学   20756篇
内科学   21480篇
皮肤病学   1479篇
神经病学   7918篇
特种医学   7328篇
外国民族医学   42篇
外科学   21138篇
综合类   31708篇
现状与发展   84篇
一般理论   5篇
预防医学   15422篇
眼科学   3494篇
药学   16912篇
  107篇
中国医学   13113篇
肿瘤学   11400篇
  2024年   432篇
  2023年   3428篇
  2022年   6570篇
  2021年   7779篇
  2020年   7562篇
  2019年   4970篇
  2018年   5380篇
  2017年   4537篇
  2016年   5135篇
  2015年   6808篇
  2014年   13867篇
  2013年   12067篇
  2012年   16366篇
  2011年   15774篇
  2010年   12234篇
  2009年   10401篇
  2008年   7942篇
  2007年   9575篇
  2006年   7560篇
  2005年   5416篇
  2004年   5112篇
  2003年   4974篇
  2002年   4208篇
  2001年   3934篇
  2000年   2968篇
  1999年   2900篇
  1998年   1797篇
  1997年   1689篇
  1996年   1059篇
  1995年   879篇
  1994年   713篇
  1993年   682篇
  1992年   937篇
  1991年   728篇
  1990年   735篇
  1989年   386篇
  1988年   411篇
  1987年   420篇
  1986年   191篇
  1985年   85篇
  1984年   121篇
  1983年   47篇
  1982年   21篇
  1981年   14篇
  1980年   11篇
  1948年   4篇
  1940年   5篇
  1939年   4篇
  1938年   4篇
  1931年   4篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
A 25-year-old, emaciated man without medical treatment was found to have died suddenly at home by his mother. At autopsy, there were no injuries to his body, but significant circulatory insufficiency was observed. Electron microscopy revealed abnormal mitochondria in cells of the cardiac conduction system. The conduction system was filled with mitochondrial size abnormalities and mitochondrial cristae abnormalities. No notable abnormal findings were observed in other organs. Genetic examination of the blood revealed the mitochondrial pathogenetic variant m.3243A>G. Epileptic seizures, diabetic ketoacidosis, and hyperosmolar hyperglycemic state were unlikely to be the cause of sudden death. The cause of death was diagnosed as arrhythmia possibly induced by the failure of the cardiac conduction system due to mitochondrial disease. This is a rare case of sudden death caused by an accumulation of abnormal mitochondria in the cardiac conduction system.  相似文献   
3.
4.
《Injury》2023,54(10):110963
IntroductionAnkle fractures comprise 9% of all fractures and are among the most common fractures requiring operative management. Open reduction and internal fixation (ORIF) with plates and screws is the gold standard for the treatment of unstable, displaced ankle fractures. While performing ORIF, orthopaedic surgeons may choose from several fixation methods including locking versus nonlocking plating and whether to use screws or suture buttons for syndesmotic injuries.Nearly all orthopaedic surgeons treat ankle fractures but most are unfamiliar with implant costs. No study to date has correlated the cost of ankle fracture fixation with health status as perceived by patients through patient reported outcomes (PROs). The purpose of this study was to determine whether there is a relationship between increasing implant cost and PROs after a rotational ankle fracture.MethodsAll ankle fractures treated with open reduction internal fixation (ORIF) at a level I academic trauma center from January 2018 to December 2022 were identified. Inclusion criteria included all rotational ankle fractures with a minimum 6-month follow-up and completed 6-month PRO. Patients were excluded for age <18, polytrauma and open fracture. Variables assessed included demographics, fracture classifications, Foot and Ankle Ability Measure-Activities of Daily Living (FAAM-ADL) score, implant type, and implant cost.ResultsThere was a statistically significant difference in cost between fracture types (p < 0.0001) with trimalleolar fractures being the most expensive. The mean FAAM-ADL score was lowest for trimalleolar fractures at 78.9, 95% CI [75.5, 82.3]. A diagnosis of osteoporosis/osteopenia was associated with a decrease in cost of $233.3, 95% CI [−411.8, −54.8]. There was no relationship between syndesmotic fixation and implant cost, $102.6, 95% CI [−74.9, 280.0]. There was no correlation between implant cost and FAAM-ADL score at 6 months (p = 0.48).ConclusionsThe utilization of higher cost ankle fixation does not correlate with better FAAM-ADL scores. Orthopaedic surgeons may choose less expensive implants to improve the value of ankle fixation without impacting patient reported outcomes.  相似文献   
5.
6.
BackgroundFocal liver lesions with spindle cell morphology are rare in the daily practice of pathology. The differential diagnosis is broad, including both tumors and tumor-like lesions. Initial radiologic assessment is sometimes inaccurate. Histopathology is needed to arrive at the correct diagnosis. This study analyzed discrepancies between histopathology and radiologic findings of focal liver lesions with spindle cell morphology.MethodsA six-year retrospective analysis was conducted at a tertiary hospital in Thailand. All focal liver lesions with spindle cell morphology were retrieved. Clinicopathologic features of these cases were analyzed. The pathological diagnosis was rendered primarily based on routine histopathology, using other ancillary studies as an adjunct.Results287 biopsies and 151 resection specimens with focal liver lesions were identified. In 12 (2.7%) cases, tumors or tumor-like lesions with spindle cell morphology were retrieved. A total of five cases had discrepancies between histopathology and radiologic findings. These lesions encompassed primary liver tumors (EBV-associated smooth muscle tumor and leiomyosarcoma); metastatic tumors (gastrointestinal stromal tumor, small cell neuroendocrine carcinoma); and a tumor-like lesion (endometriosis). Several morphologic findings (i.e., cytologic grades, dense and loose areas, intratumoral lymphocytes, distinct perinuclear vacuoles, and hemosiderin) are important clues to diagnose these spindle cell lesions.ConclusionsPathologists play a critical role in diagnosing focal liver lesions with spindle cell morphology, particularly those with limited clinical data at the initial presentation. A thorough evaluation of histomorphology on routine hematoxylin and eosin-stained slides is essential for correct diagnosis.  相似文献   
7.
8.
AimGenomic-based ancillary assays including immunohistochemistry (IHC) for BRCA-1 associated protein-1 (BAP1) and methylthioadenosine phosphorylase (MTAP), and fluorescence in situ hybridization (FISH) for CDKN2A are effective for differentiating pleural mesothelioma (PM) from reactive mesothelial proliferations. We previously reported a combination of MTAP and BAP1 IHC effectively distinguishes sarcomatoid PM from fibrous pleuritis (FP). Nevertheless, cases of sarcomatoid PM with desmoplastic features (desmoPM) are encountered where the IHC assessment is unclear.Methods and resultsWe evaluated assessment of MTAP IHC, BAP1 IHC, and CDKN2A FISH in 20 desmoPM compared to 24 FP. MTAP and BAP1 IHC could not be assessed in 11 (55 %) and 10 (50 %) cases, respectively, due to loss or faint immunoreactivity of internal positive control cells, while CDKN2A FISH could be evaluated in all cases. The sensitivities for MTAP loss, BAP1 loss, and CDKN2A homozygous deletion in desmoPM were 40 %, 10 %, and 100 %. A combination of MTAP loss and BAP1 loss yielded 45 % of sensitivity.ConclusionsMTAP IHC is a useful surrogate diagnostic marker in differentiating ordinary sarcomatoid PM from FP, but its effectiveness is limited in desmoPM. CDKN2A FISH is the most effective diagnostic assays with 100 % sensitivity and specificity in discriminating desmoPM from FP in the facilities where the FISH assay is available.  相似文献   
9.
10.
目的 临床观察白花蛇舌草干预湿热瘀滞型肠内多发息肉患者内镜治疗术后复发情况。方法 采用前瞻性的随机空白对照试验设计,选取2019年9月1日—2020年12月31日上海中医药大学附属普陀医院消化科收治的门诊及住院结直肠多发息肉患者132例作为研究对象。采用随机方法分为对照组和试验组,每组66例。对照组行内镜治疗术给予常规治疗后无药物干预,试验组在对照基础上给予白花蛇舌草汤剂(每日取白花蛇舌草15 g、大枣3枚,煎取400 mL汤剂,分2次饭后温服)治疗,连续干预1年。观察并比较两组术前与术后1年肠道内息肉的复发率、息肉数目、息肉最大直径、中医证候评分及肝肾功能及血常规的差异。结果 干预1年后,试验组复发9例(14.75%),对照组复发21例(33.33%),两组息肉复发率比较,差异有统计学意义(P<0.05)。试验组腺瘤、伴重度异型增生、体质量指数(BMI)≥24 kg·m-2患者治疗后息肉复发率均较对照组同类型降低,差异显著(P<0.05);术后1年试验组息肉最大直径及息肉数目均较对照组显著减小,差异显著(P<0.05);术后1年试验组中医证候各项评分均显著低于对照组(P<0.05);术后1年,两组中医证候疗效比较,差异具有统计学意义(P<0.05),且术前、术后1年两组患者肝肾功能、凝血功能等安全性指标无显著差异。结论 应用白花蛇舌草干预结直肠息肉术后患者,1年后明显降低肠内息肉的复发率,尤以腺瘤性息肉、重度异型增生、BMI超重患者更显著,不仅改善临床症状,还能有效预防结直肠息肉的复发,改善患者的预后。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号