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   1253篇
  免费   80篇
  国内免费   5篇
耳鼻咽喉   5篇
儿科学   46篇
妇产科学   60篇
基础医学   138篇
口腔科学   43篇
临床医学   96篇
内科学   253篇
皮肤病学   17篇
神经病学   44篇
特种医学   39篇
外科学   272篇
综合类   37篇
一般理论   1篇
预防医学   76篇
眼科学   13篇
药学   101篇
中国医学   8篇
肿瘤学   89篇
  2023年   14篇
  2022年   37篇
  2021年   45篇
  2020年   28篇
  2019年   44篇
  2018年   46篇
  2017年   31篇
  2016年   24篇
  2015年   38篇
  2014年   40篇
  2013年   55篇
  2012年   74篇
  2011年   76篇
  2010年   56篇
  2009年   39篇
  2008年   62篇
  2007年   72篇
  2006年   74篇
  2005年   54篇
  2004年   52篇
  2003年   39篇
  2002年   52篇
  2001年   23篇
  2000年   22篇
  1999年   20篇
  1998年   15篇
  1997年   8篇
  1996年   4篇
  1995年   11篇
  1994年   13篇
  1993年   7篇
  1992年   16篇
  1991年   10篇
  1990年   18篇
  1989年   15篇
  1988年   19篇
  1987年   8篇
  1986年   7篇
  1985年   10篇
  1983年   7篇
  1982年   6篇
  1980年   5篇
  1979年   3篇
  1976年   3篇
  1974年   3篇
  1972年   3篇
  1971年   3篇
  1969年   4篇
  1967年   3篇
  1966年   3篇
排序方式: 共有1338条查询结果,搜索用时 234 毫秒
51.
We evaluated the potential usefulness of three-dimensional (3D) transesophageal echocardiography (TEE) in assessing individual scallop/segment prolapse in 36 adult patients with mitral valve prolapse (MVP) undergoing surgical correction. Intraoperative 3D TEE correctly identified the location of scallop/segment prolapse in 34 of 36 patients (94%). However, in 6 of these patients 3D TEE images revealed more scallops or segments with prolapse than the surgeon noted intraoperatively. Prolapse of these areas was less prominent and this could possibly explain the lack of correlation with the surgical findings in these patients. In another 2 patients areas of prolapse seen by the surgeon were missed by 3D TEE because some of those scallops/segments could not be well imaged due to image "drop out" and artifacts. Thus, perfect correlation between 3D TEE and surgery was noted in 28 of 36 (78%) patients. Noncoaptation of the MV was also identified in 2 patients. The prolapsed area of posterior (n = 28 observations) and anterior (n = 9 observations) MV leaflets ranged from 1 cm2 to 9 cm2 (mean 3.50 cm2+/- 2.14) and 1.20 cm2 to 5.99 cm2 (mean 3.21 cm2+/- 1.33), respectively. Interobserver and intraobserver agreement for location and area of MVP was excellent (r = 0.97 and r = 0.99, respectively; all P values are <0.0001). In conclusion, 3D TEE is useful in identifying the location of MVP. It may also be potentially useful in assessing the extent of individual scallop/segment prolapse and identifying sites of MV noncoaptation. This information could aid the surgeon in deciding the extent of MV resection.  相似文献   
52.

Background/Purpose

Expert guidelines recommend performing synchronous splenectomy in patients with mild hereditary spherocytosis (HS) and symptoms of gallstone disease. This recommendation has not been widely explored in the literature. The aim of this study is to determine if our data support expert opinion and if different practice patterns should exist.

Methods

This is an IRB-approved retrospective study. All HS patients under 18 years of age who underwent cholecystectomy for symptomatic gallstones at a single institution between 1981 and 2009 were identified. Patients who underwent cholecystectomy without concurrent splenectomy were reviewed retrospectively for future need for splenectomy and evidence of recurrent gallstone disease.

Results

Of the 32 patients identified, 27 underwent synchronous splenectomy. The remaining 5 patients underwent cholecystectomy without splenectomy and had a mean age of 9.4 years. One of the 5 patients eventually required splenectomy for left upper quadrant pain. None of the remaining 4 required hospitalization for symptoms related to hemolysis or hepatobiliary disease. Median follow-up is 15.6 years.

Conclusion

The need for splenectomy in patients with mild HS and symptomatic cholelithiasis should be assessed on a case by case basis. Our recommendation is to not perform synchronous splenectomy in conjunction with cholecystectomy for these patients if no indication for splenectomy exists.  相似文献   
53.
Clinical Oral Investigations - The goal of this study is to propose a standard protocol of experimental occlusal trauma to evaluate the inflammatory hyperalgesia induced by metallic crowns on...  相似文献   
54.
Infant oral mutilation is the practice of removing developing tooth germs, commonly the mandibular canine, in infants up to the age of 1 year. Subsequent complications include missing, impacted or hypoplastic permanent anterior and canine teeth. We report on a case of bilaterally missing lower canines thought to be due to infant oral mutilation. It is important that general dental practitioners are aware of this practice and resulting complications when treating families from sub‐Saharan East Africa.  相似文献   
55.
Objective:To compare changes in pharyngeal airway volume and minimal cross-sectional area (MCA) between patients undergoing rapid maxillary expansion (RME) and a matched control group and to identify markers for predicting airway changes using cone-beam computed tomography (CBCT).Materials and Methods:Pre- and posttreatment CBCT scans were selected of children who had RME (14 girls and 12 boys; mean age, 12.4 years) along with scans of a control group (matched for chronological age, skeletal age, gender, mandibular inclination) who underwent orthodontic treatment for minor malocclusions without RME. Changes in airway volume and MCA were evaluated using a standardized, previously validated method and analyzed by a mixed-effects linear regression model.Results:Upper airway volume and MCA increased significantly over time for both the RME and matched control groups (P < .01 and P = .05, respectively). Although the RME group showed a greater increase when compared with the matched controls, this difference was not statistically significant. A reduced skeletal age before treatment was a significant marker for a positive effect on the upper airway volume and MCA changes (P < .01).Conclusions:Tooth-borne RME is not associated with a significant change in upper airway volume or MCA in children when compared with controls. The younger the skeletal age before treatment, the more positive the effect on the upper airway changes. The results may prove valuable, especially in RME of young children.  相似文献   
56.
57.
BackgroundThe treatment landscape for advanced hepatocellular carcinoma (aHCC) is rapidly expanding beyond tyrosine kinase inhibitors (TKIs) in the first-line (1L) setting, with multiple TKIs and immune-checkpoint inhibitors (ICIs) now being evaluated in combination. Real-world evidence describing current treatment patterns and reasons for 1L and 2L treatment selection in aHCC is sparse.Patients and MethodsA retrospective cohort study with a cross-sectional survey element was conducted using Cardinal Health’s Oncology Provider Extended Network. U.S. medical oncologists identified adult aHCC patients initiating 1L systemic therapy between January 1, 2017 and July 31, 2019 and abstracted data from patient medical records. Data included provider characteristics, patient demographics and clinical characteristics, treatment regimens, and physician rationale for treatment regimen choice.ResultsA total of 44 medical oncologists provided data on 284 aHCC patients. The median age at 1L initiation was 61.5 years, and the majority were male (78%) and white (66%). Nearly half (47%) initiated 1L treatment in 2019, 34% were ECOG performance status 2+, and 63% were Child-Pugh Class B/C. Among the 284 aHCC patients, TKIs were used by 94% of patients in the 1L setting, comprised predominantly of sorafenib (54%) and lenvatinib (38%). ICIs were most common among the 90 patients (66%) who received 2L treatment.ConclusionIn the community-oncology practice setting, nearly all aHCC patients received sorafenib or lenvatinib in the 1L setting, while the majority of patients received an ICI in the 2L setting. With recent ICI approvals in aHCC, this marks the beginning of an increased use of ICIs in the 1L setting.  相似文献   
58.
Treatment options for neurodegenerative conditions such as Parkinson''s disease have included the delivery of cells which release dopamine or neurotrophic factors to the brain. Here, we report the development of a novel approach for protecting cells after implantation into the central nervous system (CNS), by developing dual-layer alginate beads that encapsulate therapeutic cells and release an immunomodulatory compound in a sustained manner. An optimal alginate formulation was selected with a view to providing a sustained physical barrier between engrafted cells and host tissue, enabling exchange of small molecules while blocking components of the host immune response. In addition, a potent immunosuppressant, FK506, was incorporated into the outer layer of alginate beads using electrosprayed poly-ε-caprolactone core–shell nanoparticles with prolonged release profiles. The stiffness, porosity, stability and ability of the alginate beads to support and protect encapsulated SH-SY5Y cells was demonstrated, and the release profile of FK506 and its effect on T-cell proliferation in vitro was characterized. Collectively, our results indicate this multi-layer encapsulation technology has the potential to be suitable for use in CNS cell delivery, to protect implanted cells from host immune responses whilst providing permeability to nutrients and released therapeutic molecules.

Novel composite cell encapsulation system: dual-layer, micro-scale beads maintain cell survival while releasing immunomodulatory FK506 in a sustained manner. This biotechnology platform could be applicable for treatment of CNS and other disorders.  相似文献   
59.
Objective: Exclusive polymeric diet enriched with transforming growth factor-beta 2 (ANS-TGF-β2) has been used for remission induction and maintenance in pediatric Crohn’s disease (CD). Its use in the preoperative setting has never been evaluated. The aim of this study was to evaluate preoperative ANS-TGF-β2 to decrease postoperative complications after surgery for complicated ileocolonic CD.

Methods: From 2011 to 2015, data of all consecutive patients who underwent elective surgery for ileocolonic CD were collected prospectively. Preoperative, exclusive ANS-TGF-β2 was administered in high-risk patients with complicated CD. Complicated CD was defined by the presence of obstructive symptoms, and/or steroid treatment, and/or preoperative weight loss >10% and/or perforating CD. Outcomes of high-risk patients receiving preoperative ANS-TGF-β2 were compared to those of low-risk patients with no complicated CD who underwent upfront surgery.

Results: Fifty-six patients underwent surgery for ileocolonic CD. Among them, 35 high-risk patients received preoperative ANS-TGF-β2 and 21 low-risk patients underwent upfront surgery. Preoperative full-dose ANS-TGF-β2 was feasible in 34/35 high-risk patients. Discontinuation of steroids during preoperative ANS-TGF-β2 could be achieved in 10/16 patients (62.5%). Postoperative complications rates were 8/35 (23.8%) and 5/21 (22.9%) in high-risk and low-risk patients, respectively (p?=?1). Temporary ileocolostomy rates in high-risk patients and in low-risk patients were 4/35 (11%) and 0/21, respectively (p?=?0.286)

Conclusion: Preoperative ANS-TGF-β2 is feasible in most high-risk patients with complicated ileocolonic CD and could limit the deleterious effects of risk factors of postoperative morbidity. These results need to be confirmed in a large randomized controlled trial.  相似文献   
60.
A 3‐year‐old child presented with recurrent chest pain for 3 months, echocardiography showed a thorn inside the left ventricle, the patient was diagnosed with foreign body complicated with infective endocarditis and received proper treatment, and operation was performed after inflammatory reaction subsided.  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