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   1872篇
  免费   87篇
  国内免费   16篇
耳鼻咽喉   7篇
儿科学   37篇
妇产科学   43篇
基础医学   277篇
口腔科学   96篇
临床医学   102篇
内科学   529篇
皮肤病学   6篇
神经病学   106篇
特种医学   65篇
外科学   344篇
综合类   2篇
预防医学   34篇
眼科学   20篇
药学   71篇
肿瘤学   236篇
  2023年   12篇
  2022年   21篇
  2021年   43篇
  2020年   29篇
  2019年   48篇
  2018年   44篇
  2017年   30篇
  2016年   55篇
  2015年   61篇
  2014年   70篇
  2013年   71篇
  2012年   140篇
  2011年   139篇
  2010年   84篇
  2009年   62篇
  2008年   119篇
  2007年   113篇
  2006年   101篇
  2005年   122篇
  2004年   120篇
  2003年   110篇
  2002年   107篇
  2001年   21篇
  2000年   16篇
  1999年   21篇
  1998年   21篇
  1997年   13篇
  1996年   18篇
  1995年   17篇
  1994年   14篇
  1993年   18篇
  1992年   23篇
  1991年   10篇
  1990年   15篇
  1989年   9篇
  1988年   10篇
  1987年   7篇
  1986年   7篇
  1985年   2篇
  1984年   2篇
  1983年   4篇
  1982年   6篇
  1981年   2篇
  1979年   3篇
  1977年   2篇
  1976年   2篇
  1972年   2篇
  1968年   1篇
  1938年   2篇
  1937年   1篇
排序方式: 共有1975条查询结果,搜索用时 15 毫秒
81.
A 71-year-old female presented to our hospital due to pain from the right hip joint to the lower abdomen. The pain had suddenly appeared and spontaneously disappeared more than 10 times during the past 2 years. She had visited many hospitals, but remained undiagnosed. The patient underwent a computed tomography (CT) scan of the pelvis, and a soft tissue shadow was seen between the external obturator and pectineal muscles. She was diagnosed with a right obturator hernia and underwent elective repair by laparoscopic trans-peritoneal hernioplasty (TAPP). 1 year has passed since the surgery, without any recurrence of the abdominal pain. Obturator hernias are rare, and most cases are found as incarcerated hernias. It is rare to find an obturator hernia without intestinal obstruction, or with the recurrent pain as in our case. We herein report a case in which an obturator hernia was undiagnosed and intermittent pain was experienced for 2 years prior to TAPP, which appears to have successfully treated the hernia.  相似文献   
82.
83.
BackgroundFew studies have investigated right atrial (RA) remodeling in heart failure (HF) with preserved ejection fraction (HFpEF). This study sought to characterize the RA remodeling in HFpEF and to determine its prognostic significance.Methods and ResultsPatients with HFpEF were classified based on the presence of RA enlargement (RA volume index >39 mL/m2 in men and >33 mL/m2 in women). Compared with patients with normal RA size (n = 234), patients with RA dilation (n = 67) showed a higher prevalence of atrial fibrillation (AF), worse right ventricular systolic function, more severe pulmonary hypertension, and a greater prevalence of mild tricuspid regurgitation, as well as impaired RA reservoir function, with increased hepatobiliary enzyme levels. AF was strongly associated with the presence of RA dilation (odds ratio [OR] 10.2, 95% confidence interval [CI] 4.00–26.1 in current AF vs no AF and odds ratio 3.38, 95% CI 1.26–9.07, earlier AF vs no AF). Patients with RA dilation had more than a two-fold increased risk of composite outcomes of all-cause mortality or HF hospitalization (adjusted hazard ratio 2.01, 95% CI 1.09–3.70, P = .02). The presence of RA dilation also displayed an additive prognostic value over left atrial dilation alone.ConclusionsThese data demonstrate that HFpEF with RA remodeling is associated with distinct echocardiographic features characterizing advanced right heart dysfunction with an increased risk of adverse outcomes.  相似文献   
84.
85.
86.
Higuchi  Tadashi  Ozawa  Soji  Koyanagi  Kazuo  Ninomiya  Yamato  Yatabe  Kentaro  Yamamoto  Miho  Tajima  Kohei  Nomura  Takakiyo  Niwa  Tetsu 《Esophagus》2021,18(4):764-772
Purpose

The study aimed to evaluate the usefulness of prone-position computed tomography (CT) for predicting relevant thoracic procedure outcomes in minimally invasive esophagectomy (MIE) for thoracic esophageal cancer.

Materials and methods

A total of 59 patients underwent esophagectomy between May 2019 and December 2020 in Tokai University Hospital. Preoperative CT imaging was conducted with the patient in both the supine and prone positions, and the magnitude of change in the intramediastinal space was calculated. In the 56 patients (94.9%) who had undergone MIE, the effects of such a difference on the surgical outcomes were analyzed.

Results

A significant correlation of the magnitude of change in VE (distance between ventral aspect of the vertebral body and the midpoint of the esophagus) with the surgical outcome was revealed in the 17 patients (30.4%) in whom the magnitude of change in VE was over the 75th percentile. That is, in this subgroup, the magnitude of change in VE showed a negative correlation with the thoracic operation time (rs?=???0.57, p?=?0.01) and blood loss during the thoracic procedure (rs?=???0.46, p?=?0.01). Multivariate analysis identified a magnitude of change in VE?≥?9 mm (OR?=?0.14, p?=?0.03) as an independent risk factor for postoperative pneumonia.

Conclusions

This study indicates that preoperative prone-position CT imaging is useful for predicting the level of ease or difficulty of securing an adequate operative field, surgical outcomes, and the risk of postoperative pneumonia in MIE.

  相似文献   
87.
Background & Aims: Interleukin (IL)-15 has been found to share many immunoregulatory activities in lymphocytes with IL-2. The aim of this study was to investigate IL-15 activity in organ cultures, localization of IL-15 messenger RNA (mRNA), and proliferation of lamina propria mononuclear cells (LPMCs) in response to recombinant IL-15 using the mucosal tissues obtained from patients with inflammatory bowel disease (IBD). Methods: The contents of IL-15, tumor necrosis factor α, and IL-2 in the culture supernatant of the rectal mucosal tissues were determined by an enzyme-linked immunosorbent assay. Expression of IL-15 mRNA was analyzed by in situ hybridization, and proliferative response of LPMCs to recombinant IL-15 was determined by [3H]thymidine incorporation into DNA. Results: Significantly greater IL-15 activity was detected in active IBD, and this elevation was also observed in inactive ulcerative colitis. In contrast, greater tumor necrosis factor α activity was observed only in active IBD, and IL-2 was not detected in organ cultures. In situ hybridization showed IL-15 mRNA in macrophages and epithelial cells in active IBD specimens, and recombinant IL-15 induced a dose-dependent proliferative response in LPMCs. Conclusions: Mucosal IL-15 may be involved in the pathogenesis of IBD as one of the important mediators in activation of mucosal immune cells.GASTROENTEROLOGY 1998;114:1237-1243  相似文献   
88.
The aim of the present study was to establish a convenient clinically applicable assay method for chymase-dependent angiotensin II forming activity of circulating mononuclear leukocytes (CML), which was potentially a marker of tissue chymase activity. Using this method, association between CML chymase activity and clinical parameters was determined.

Cardiovascular outpatients (n = 170) without taking antihypertensive medication were recruited.

An ELISA for chymase-dependent angiotensin II-forming activity in CML was established using Nma /Dnp-modified angiotensin I.

Logistic regression analysis revealed that age and male gender were significant independent determinants of the increased CML chymase activity. After adjustment by age and gender, the CML chymase activity was positively correlated with systolic blood pressure, pulse rate, and the brain natriuretic peptide level.

The relation between blood pressure and CML chymase activity suggests that it might reflect that increased tissue chymase activity contributes to systemic high blood pressure and heart rate because plasma chymase is inactive due to inhibitory plasma inhibitors.  相似文献   

89.
90.
ObjectiveComputer-aided design and computer-aided manufacturing (CAD/CAM) techniques are increasingly applied to mandibular reconstruction, but the superiority of this method in oral food intake has not been well established. Considering the extent of mandibular defects, this retrospective study was aimed to clarify the impact of CAD/CAM mandibular reconstruction on chewing and swallowing function after surgery for locally advanced oral cancer.Materials and methodsWe performed a retrospective review of 50 patients who had undergone segmental mandibulectomy with free flap reconstruction for locally advanced oral cancer. The patients’ Functional Oral Intake Scale scores were measured at 3 months after surgery, and possible contributing factors including CAD/CAM mandibular reconstruction and the extent of mandibular defects for oral food intake were subjected to univariate analysis and multivariate logistic regression analysis.ResultsMultivariate logistic regression analysis showed that CAD/CAM mandibular reconstruction was independently associated with good oral intake, whereas both anterior or extensive mandibular resection and glossectomy were also independently associated with poor oral intake after surgery.ConclusionThe present study showed the positive impact of CAD/CAM mandibular reconstruction on chewing and swallowing function after surgery for locally advanced oral cancer for the first time.  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