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   9439篇
  免费   708篇
  国内免费   33篇
耳鼻咽喉   122篇
儿科学   240篇
妇产科学   245篇
基础医学   1516篇
口腔科学   162篇
临床医学   816篇
内科学   2109篇
皮肤病学   127篇
神经病学   893篇
特种医学   365篇
外科学   1264篇
综合类   117篇
现状与发展   1篇
一般理论   15篇
预防医学   771篇
眼科学   232篇
药学   540篇
中国医学   11篇
肿瘤学   634篇
  2023年   101篇
  2022年   188篇
  2021年   313篇
  2020年   179篇
  2019年   316篇
  2018年   325篇
  2017年   198篇
  2016年   218篇
  2015年   273篇
  2014年   328篇
  2013年   474篇
  2012年   603篇
  2011年   659篇
  2010年   320篇
  2009年   337篇
  2008年   511篇
  2007年   562篇
  2006年   479篇
  2005年   487篇
  2004年   516篇
  2003年   466篇
  2002年   440篇
  2001年   127篇
  2000年   92篇
  1999年   105篇
  1998年   90篇
  1997年   80篇
  1996年   67篇
  1995年   69篇
  1994年   57篇
  1993年   55篇
  1992年   57篇
  1991年   54篇
  1990年   48篇
  1989年   61篇
  1988年   50篇
  1987年   57篇
  1986年   36篇
  1985年   39篇
  1984年   42篇
  1983年   40篇
  1982年   38篇
  1980年   33篇
  1979年   33篇
  1978年   31篇
  1976年   32篇
  1974年   35篇
  1973年   44篇
  1971年   34篇
  1970年   32篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
81.
Obturator hernia   总被引:2,自引:0,他引:2  
  相似文献   
82.
The increased use of sentinel lymph node (SLN) excision for staging the axilla in women with breast cancer has benefited women by lowering morbidity and at the same time has raised issues related to the extent of treatment needed to the nodal basin. This is of particular concern when micrometastases or isolated tumor cells are found in the sentinel nodes on the final pathology. The probability of finding metastatic disease in non-sentinel lymph nodes (NSLN) ranges from 0 to 20% with only micrometastatic deposits in the SLN. Very low rates (0-3.7%) of axillary recurrence have been reported in selected patients with micrometastases tumor in sentinel nodes who have not had a completion axillary node dissection (ALND). Risk factors for additional positive NSLN include primary tumor size, the presence of lymphovascular invasion and the size of the SN metastatic deposit. Currently, the decision to not complete the ALND when micrometastic disease is found in the SLN should be made on a case-by-case basis. One should consider the tumor characteristics, findings within the SLN, and a multidisciplinary treatment plan. Clinical trial results may help to resolve the dilemma. There appears to be a low risk for axillary recurrence.  相似文献   
83.
84.
In poly‐traumatic patients a blunt chest trauma is an important trigger of the posttraumatic systemic inflammatory response. There is clinical evidence that fracture healing is delayed in such patients, however, experimental data are lacking. Therefore, we investigated the influence of a thoracic trauma on fracture healing in a rat model. Male Wistar rats received either a blunt chest trauma combined with a femur osteotomy or an isolated osteotomy. A more rigid or a more flexible external fixator was used for fracture stabilization to analyze whether the thoracic trauma influences regular healing and mechanically induced delayed bone healing differently. The blunt chest trauma induced a significant increase of IL‐6 serum levels after 6 and 24 h, suggesting the induction of a systemic inflammation, whereas the isolated fracture had no effect. Under a more rigid fixation the thoracic trauma considerably impaired fracture healing after 35 days, reflected by a significantly reduced flexural rigidity (three‐point‐bending test), as well as a significantly diminished callus volume, moment of inertia, and relative bone surface (µCT analysis). In confirming the clinical evidence, this study reports for the first time that a blunt chest trauma considerably impaired bone healing, possibly via the interaction of the induced systemic inflammation with local inflammatory processes. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:734–739, 2011  相似文献   
85.
Cystinosis is a rare autosomal recessive disease caused by mutations of the CTNS gene in which cystine accumulates throughout the body as a result of a defective efflux of cystine from lysosomes. Three phenotypic forms have been described according to the age of onset and the severity of the clinical symptoms: infantile, intermediate, and ocular non-nephropathic cystinosis. Here we report the natural history of cystinosis in a 55-year-old man with intermediate nephropathic cystinosis diagnosed at 9 years of age. Although tubulopathy was unnoticed in the early years, he required transplantation at age 16. Sequencing analysis of all the CTNS exons revealed that the proband is homozygous for a 21-bp in-frame deletion in exon 5 (c. 198_218del21), resulting in an in-frame deletion of 7 amino acids from the N-terminal domain of the cystinosin protein. Our patient has had relatively mild extra-renal disease despite lack of early cysteamine therapy. He has been able to attend university and pursue a professional career into the 6th decade.  相似文献   
86.
Mechanical occlusion of the right coronary artery during aortic valve surgery is an infrequent but serious complication. Early recognition and expeditious management are important to reduce mortality. We developed a safe, quick, and easy technique to assess right coronary artery flow after aortic valve surgery. Direct intraoperative right coronary artery flow was measured by placing a transit-time flowmeter probe around the right coronary artery. We were able to promptly detect severe right coronary artery insufficiency in patients with acute unexpected right ventricular failure after aortic valve replacement.  相似文献   
87.
OBJECT: Vestibular schwannomas (VSs) with no or little extension into the internal auditory canal have been addressed as a clinical subentity carrying a poor prognosis regarding hearing preservation, which is attributed to the initially asymptomatic intracisternal growth pattern. The goal in this study was to assess hearing preservation in patients who underwent surgery for medial VSs. METHODS: A consecutive series of 31 cases in 30 patients with medial VSs (mean size 31 mm) who underwent surgery between 1997 and 2005 via a suboccipitolateral route was evaluated with respect to pre- and postoperative cochlear nerve function, extent of tumor removal, and radiological findings. Intraoperative monitoring of brainstem auditory evoked potentials was performed in all patients with hearing. Patients were reevaluated at a mean of 30 months following surgery. RESULTS: Preoperative hearing function revealed American Academy of Otolaryngology-Head and Neck Surgery Foundation Classes A and B in 7 patients each, Class C in 4, and D in 9. Four patients presented with deafness. Hearing preservation was achieved in 10 patients (Classes A-C in 2 patients each, and Class D in 4 patients). Tumor removal was complete in all patients with hearing preservation, except for 2 patients with neurofibromatosis. In 4 patients a planned subtotal excision was performed due to the individual's age or underlying disease. In 1 patient a recurrent tumor was completely removed 3 years after the initial procedure. CONCLUSIONS: The cochlear nerve in medial VSs requires special attention due to the atypical intracisternal growth pattern. Even in large tumors, hearing could be preserved in 37% of cases, since the cochlear nerve in medial schwannomas may not exhibit the adherence to the tumor capsule seen in tumors with comparable size involving the internal auditory canal.  相似文献   
88.
Effects of spinal cord injury on semen parameters   总被引:1,自引:0,他引:1  
OBJECTIVE/BACKGROUND: Neurogenic reproductive dysfunction in men with spinal cord injury (SCI) is common and the result of a combination of impotence, ejaculatory failure, and abnormal semen characteristics. It is well established that the semen quality of men with SCI is poor and that changes are seen as early as 2 weeks after injury. The distinguishing characters of poor quality are abnormal sperm motility and viability. In the majority of the men with SCI, the sperm count is not abnormal. We elaborate on the effects of the SCI on semen parameters that may contribute to poor motility and poor viability. METHODS: Review. DESIGN: PubMed and MEDLINE databases were searched using the following key words: spinal cord injuries, fertility, sexual dysfunction, and spermatogenesis. All literature was reviewed by the team of authors according to the various stages of sperm development and transport in the male reproductive cycle. FINDINGS: The cause of asthenozoospermia appears to be multifactorial. CONCLUSION: Current literature does not support the preeminence of a single factor relating to neurogenic reproductive dysfunction in men with SCI. After SCI, there is ample evidence of disturbance of sperm production, maturation and storage, and transport due to an abnormal neuroendocrine milieu. Semen quality seems to be primarily affected by changes to the seminal plasma constituents, type of bladder management, and the neurogenic impairment to the ejaculatory function. Further focused and structured studies are required.  相似文献   
89.
The aim of a surgical residency program is to produce competent professionals displaying the cognitive, technical, and personal skills required to meet the needs of society. Current changes to the delivery of healthcare necessitate the development of new models of training. These can be supported with the development of new technologies to train and assess surgical practitioners. This article describes recent developments within Imperial College London with regard to eye tracking, noninvasive brain imaging, and an innovative mentoring scheme for the new surgical curriculum. The concept of eye tracking is described, together with surgical application for this technique in terms of dexterity analysis during minimally invasive procedures. We have also begun to understand spatial localization within the brain cortex during surgical knot-tying tasks. The aim is to develop a map of the cortex with regard to surgical novices and experienced surgeons and then to develop the hypothesis that a translational process of cortical plasticity occurs during training. Finally, the article is intended to describe a training scheme that goes beyond dexterity, and moves toward the development of a successful surgeon through surgical mentoring. It is hoped that some of these tools will enhance the training of future surgeons in order to continue to provide a high-quality service to our patients.  相似文献   
90.
Zusammenfassung. Einleitung: Vorgestellt wird ein neuartiges Trokarprinzip für die minimal-invasive Chirurgie. Es handelt sich um eine Spirale, deren Wendel sukzessive nach zentral hin an St?rke zunimmt. Dadurch entsteht ein flie?ender übergang von Spirale über Schraube bis hin zum Stab. Der Au?endurchmesser bleibt dabei gleich. Der Spiraltrokar wird wie ein Korkenzieher durch die Bauchdecke geschraubt. Der prim?re Punktionskanal verl?uft daher als Spirale. Im Weiteren wird der Kanal dilatiert und zentriert, so dass der stabf?rmige Anteil des Trokars mit der darüber geführten Arbeitshülse durch die Bauchdecke geschoben werden kann. Das Trokardesign weist folgende Vorteile auf: Der Trokar kann kontrolliert durch die Bauchdecke geschraubt werden ohne dass dabei axialer Druck angewendet werden muss. Dadurch wird die Gefahr von Organverletzungen minimiert. Da die verschiedenen Gewebeschichten an unterschiedlichen Stellen punktiert werden, k?nnen sie sich nach Entfernung der Arbeitshülse wieder gegenseitig verschlie?en. Der verbleibende Punktionskanal ist sehr klein und das Risiko der Entstehung von Trokarkanalhernien gering. Methode: Der Spiraltrokar wurde in vivo und in vitro untersucht und mit anderen Trokatypen verglichen. Ergebnisse: Er wies ein hohes Sicherheitsniveau und gute Handlingeigenschaften auf. Schlussfolgerung: Da es sich um ein einfach zu reinigendes Mehrwegprodukt ohne mechanische Verschleissteile handelt, dass mit den meisten Arbeitshülsen kompatibel ist, besteht auch eine hohe Kosteneffizienz.   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