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   6685篇
  免费   82篇
  国内免费   6篇
耳鼻咽喉   265篇
儿科学   245篇
妇产科学   360篇
基础医学   275篇
口腔科学   112篇
临床医学   338篇
内科学   1360篇
皮肤病学   310篇
神经病学   287篇
特种医学   508篇
外科学   1935篇
综合类   21篇
预防医学   192篇
眼科学   254篇
药学   44篇
中国医学   1篇
肿瘤学   266篇
  2023年   8篇
  2021年   5篇
  2020年   8篇
  2019年   5篇
  2018年   23篇
  2017年   18篇
  2016年   27篇
  2015年   501篇
  2014年   564篇
  2013年   557篇
  2012年   563篇
  2011年   512篇
  2010年   579篇
  2009年   546篇
  2008年   565篇
  2007年   490篇
  2006年   458篇
  2005年   391篇
  2004年   262篇
  2003年   51篇
  2002年   10篇
  2001年   13篇
  2000年   11篇
  1999年   29篇
  1998年   25篇
  1997年   45篇
  1996年   41篇
  1995年   26篇
  1994年   25篇
  1993年   29篇
  1992年   19篇
  1991年   26篇
  1990年   18篇
  1989年   23篇
  1988年   21篇
  1987年   18篇
  1986年   17篇
  1985年   12篇
  1984年   20篇
  1983年   31篇
  1982年   30篇
  1981年   27篇
  1980年   22篇
  1979年   21篇
  1978年   5篇
  1977年   10篇
  1976年   11篇
  1975年   9篇
  1974年   6篇
  1973年   7篇
排序方式: 共有6773条查询结果,搜索用时 0 毫秒
61.
Corvin S  Feil G  Stenzl A 《Der Urologe. Ausg. A》2004,43(10):1213-1216
Congenital or acquired disorders of the urethra or ureter often require adequate tissue transfer for reconstruction. A variety of biomaterials have proved to be useful in the reconstruction of the urethra or ureter in animal models and meanwhile even clinically. Innovative tissues such as acellular matrices can be placed in the host and function as a scaffold to allow the natural process of tissue regeneration. Biodegradable scaffolds can also be used as cell transplantation vehicles for the reconstruction of urethral or ureteral tissue. One of the limitations of cell-based tissue engineering techniques however is the difficulty of growing genitourinary-associated cells in large quantities in primary cultures. It can be speculated that stem cell research might help to overcome this specific problem in the future.  相似文献   
62.
We report about the first hip arthroscopies of extracapsular neglected hip dislocations with concomitant injuries in two children (2 and 4 years old). The major problem of traumatic hip dislocation is avascular necrosis. Further problems are possible concomitant injuries. It is important not to cause further damage by therapeutic procedures. In a 4-year-old child the hip could be reduced under visualization and in a 2-year-old child with epiphyseal fracture the extent of the operation could be reduced. In both children large avulsion injuries of the ligamentum capitis femoris could be resected via hip arthroscopy. Hip arthroscopy can reduce surgical morbidity considerably and can possibly contribute to prevention of the feared avascular necrosis of the femoral head.  相似文献   
63.
Rückfu?valgus     
The clinical finding of flatfoot is characterized by a flattening of the medial longitudinal arch and valgus deformity of the hindfoot. The differential diagnosis of flatfoot is the physiological, flexible, contracted flatfoot, which occurs as a congenital or acquired deformity. Congenital flatfoot deformity requires early intensive therapy, while a flexible flatfoot in children has a good prognosis and conservative treatment usually leads to a stable and sufficient load-bearing foot. Severe flatfoot in children can be corrected successfully by simple, minimally invasive procedures. In adults with symptomatic flatfoot, which usually occurs due to an insufficiency of the tendon of the tibialis posterior, conservative therapy with insoles, shoe modifications and physiotherapeutic measures can lead to significant improvement, otherwise surgical correction is recommended. Early, stage-appropriate therapy helps to prevent an impending decompensation of the hindfoot.  相似文献   
64.
The purpose of the present study was to analyze the risk factors associated with unexpected second procedures and strategies of revision surgery. Within a 5 year period 647 patients with closed ankle fractures AO type 44 were identified of which 77 (11.9%) needed revision surgery. Complications were addressed to 4 main groups: deep infections (IG) were seen in 29 patients (4.5%), problems with primary wound closure (WG) in 22 patients (3.4%), insufficient reduction (KG) in 22 patients (3.4%) and other causes (RG) included 4 patients (0.6%). Significant predictive factors for soft tissue complications were higher age, comorbidities with peripheral arteriosclerosis, high American Society of Anesthesiologists (ASA) score and diabetes mellitus. AO 44 type B2 and B3 fractures were often associated with soft tissue problems. The more complex fracture types AO 44 C1-C3 and A2-A3 were significantly associated with problems of insufficient congruency post-surgery. The distribution of the mean revision rate was significantly different (p<0.01) for all groups: IG 4.59, WG 3.5, KG 1.55, RG 1.25. In summary, we strongly recommend immediate reduction of displaced fractures and to consider a more detailed fracture classification. To reduce the amount of unexpected ankle procedures individual risk factors should be weighed against the advantages of optimal open reduction and internal fixation.  相似文献   
65.
Paraplegic spina bifida patients often suffer from disturbed sweat secretion in the paretic regions. A diminished sweat production of caudal parts of the body is compensated by an increased secretion of sweat in parts cranial to the lesion to maintain temperature homoeostais. If the sweat secretion is blocked by anticholinergic effects of urotherapeutic drugs (for instance oxybutynin) hyperthermia can result as a side effect as these casuistic examples show.An 8-year-old girl with a lumbar meningomyelocele and a neurogenic bladder reported a dry skin and hyperthermia up to 38,5°C during oral therapy with oxybutynin (0.4 mg per kg body weight) during hot summer days. Similar symptoms were shown by a 7-year-old male patient with a sacral meningomyelocele and neurogenic bladder on oral therapy of 0.35 mg oxybutynin per kg body weight. A 4-year-old female patient with lumbar spina bifida and neurogenic bladder reacted to intravesical administration of 0.4 and 0.3 mg per kg body weight during early summertime with hyperthermia up to 38°C. In this case the medication had been started in wintertime and was primarily well tolerated.Hyperthermia under treatment with anticholinergic drugs has mainly been published for geriatric patients with sometimes fatal outcome. In the pediatric literature there is only one warning regarding the use of oxybutynin in children with spina bifida living in high temperature regions. It is remarkable that hyperthermia can also happen after intravesical administration of oxybutynin in usual dosage.  相似文献   
66.
ZusammenfassungHintergrund Die MRT stellt ein sensitives, nicht strahlenbelastendes bildgebendes Verfahren dar und bietet sich daher für die Diagnostik kindlicher Wirbelsäulenverletzungen an. Als ein indirektes Verletzungszeichen lässt sich hierbei u. U. ein sog. bone bruise nachweisen, ohne dass weitere Verletzungen sichtbar werden. Ziel der vorliegenden Arbeit war es, die klinische Bedeutung dieser Diagnose bei kindlichen Wirbelsäulenverletzungen zu untersuchen.Patienten und Methoden Zwischen 1998 und 2003 wurden in unserer Klinik insgesamt 66 Kinder mit Wirbelsäulenverletzungen konservativ behandelt. 34 dieser Kinder erhielten während der Primärdiagnostik eine MRT. Im Rahmen einer retrospektiven Studie wurden 20 Kinder, bei welchen die Diagnose einer Wirbelkörperverletzung vorwiegend durch den Nachweis eines bone bruise im initialen MRT geführt worden war, sowohl klinisch als auch mittels MRT nachuntersucht.Ergebnisse Alle 20 Kinder gaben bei der Nachuntersuchung subjektiv weitgehende Beschwerdefreiheit an. Bei der objektiven Untersuchung fanden sich keine klinischen Auffälligkeiten. Bei keinem der Kinder war im Rahmen der Nachuntersuchung MR-tomographisch eine Persistenz des bone bruise feststellbar. Eine sekundäre Sinterung der betroffenen Wirbelkörper war in keinem Fall aufgetreten.Schlussfolgerung Kindliche Wirbelsäulenverletzungen, die mit einem mittels MRT nachgewiesenen bone bruise ohne weitere bildmorphologische knöcherne oder diskoligamentäre Läsionen einhergehen, sind in der Regel als prognostisch günstig einzustufen. Bei entsprechender Therapie, die in einer kurzfristigen, schmerzadaptierten Bettruhe und einer anschließenden frühfunktionellen Behandlung besteht, wurden bei unseren Patienten keine sekundären Sinterungen beobachtet.* Beide Autoren haben gleichen Anteil an dieser Arbeit und teilen sich die Erstautorenschaft.  相似文献   
67.
According to the new ICS classification, urinary incontinence is subdivided by symptomatic, clinical, and urodynamic criteria. Understanding the pathophysiological interactions is important to find the correct diagnosis. Disturbances in bladder storage include urge incontinence due to neurogenic or non-neurogenic (idiopathic) detrusor hyperactivity as well as stress urinary incontinence caused by an insufficient urethral closure mechanism due to reduced pressure transmission (active-passive), hypotonic urethra, hyporeactivity of sphincter musculature, or involuntary relaxation of the urethra. Stress and urge incontinence can occur in combination and then be defined as mixed incontinence.  相似文献   
68.
Improvements of radiotherapy in combination with surgery and systemic therapy have resulted in increased survival rates of tumor patients. However, radiation-induced normal tissue toxicity is still dose limiting. Several strategies have been pursued with the goal to develop substances which may prevent or reduce damage to normal tissue. Drugs applied before radiotherapy are called radioprotectors; those given after radiotherapy to reduce long-term effects are radiomitigators. Despite more than 50 years of research, until now only two substances, amifostine and palifermin, have overcome all obstacles of clinical approval and are applied during radiotherapy of head and neck cancer or total body irradiation, respectively. However, better understanding of the cellular pathways involved in radiation response has allowed the development of several highly promising drugs functioning as scavengers of reactive oxygen species or targeting specific molecules involved in regulation of cell death pathways or cell cycle arrest. The present review describes the major targets for radioprotectors or radiomitigators currently tested in clinical trials.  相似文献   
69.

Clinical/methodical issue

Diagnostic imaging of complex multiple trauma remains a challenge for any department providing modern emergency radiology (ER) service. An early and comprehensive approach for ER imaging is crucial for a priority-oriented and timely therapy concept with the aim of identifying potentially life-threatening injuries early and initiating appropriate treatment.

Standard radiological methods

The basic diagnostic approach still consists of focused ultrasound using focused assessment with sonography for trauma (FAST) and conventional radiography (CR), usually limited to a single supine chest x-ray for triaging patients undergoing immediate operations.

Methodical innovations

Multidetector computed tomography (MDCT) has become established as early whole body CT (WBCT) as the undisputable diagnostic method. The detection rate of injuries by WBCT is outstanding and it improves the probability of survival by 20–25?% compared with all other previous methods. At the same time, the spatial and temporal resolution of MDCT was improved resulting in considerably shortened examination times but WBCT is still associated with a significant radiation exposure, even in the acute single use setting. Using modern scanner and dose reduction technology, including iterative reconstruction, a dose reduction of up to 40?% could be achieved. The substantial number of images in WBCT is another challenge; images must be processed priority-oriented, read and transferred to the picture archiving and communications system (PACS). For rapid diagnosis, volume image reading (VIR) offers additional options to keep the diagnostic process on time.

Achievements/practical recommendations

Modern WBCT after multiple trauma is performed early, comprehensively and personalized so that WBCT improves the probability of survival by 20–25?%.  相似文献   
70.

Clinical/methodical issue

Imaging plays an essential role in the therapeutic management of cancer of unknown primary (CUP) patients for localizing the primary tumor, for the identification of tumor entities for which a dedicated therapy regimen is available and for the characterization of clinicopathological subentities that direct the subsequent diagnostic and therapeutic strategy.

Standard radiological methods

Modalities include conventional x-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound as well as positron emission tomography (PET)-CT and MRI-PET.

Performance

In whole body imaging CT has a high sensitivity for tumor entities which frequently present as a metastasized cancer illness. According to the current literature CT is diagnostic in 86% of patients with pancreatic carcinoma, in 36% of patients with colon carcinoma and in 74% of patients with lung carcinoma. Additionally a meta-analysis showed that for patients with squamous cell carcinoma and cervical lymph node metastases a positive diagnosis was possible in 22% of the cases using CT, in 36% using MRI and in 28-57% using 18F-fluorodeoxyglucose PET-CT (18F-FDG PET-CT). In addition, MRI plays an important role in the localization of primary occult tumors (e.g. breast and prostate) because of its high soft tissue contrast and options for functional imaging.

Achievements

At the beginning of the diagnostic algorithm stands the search for a possible primary tumor and CT of the neck, thorax and abdomen is most frequently used for whole body staging. Subsequent organ-specific imaging examinations follow, e.g. mammography in women with axillary lymphadenopathy. For histological and immunohistochemical characterization of tumor tissue, imaging is also applied to identify the most accessible and representative tumor manifestation for biopsy. Tumor biopsy may be guided by CT, MRI or ultrasound and MRI also plays a central role in the localization of primary occult tumors because of superior soft tissue contrast and options for functional imaging (perfusion, diffusion), e.g. investigation of breast carcinoma or prostate carcinoma.

Practical recommendations

Whole body staging stands at the beginning of the diagnostic algorithm in CUP syndrome to localize a potential primary tumor. Clinically, contrast-enhanced CT of the neck, thorax and abdomen is frequently applied; however, many studies have demonstrated augmented sensitivity of 18F-FDG PET-CT for the detection of primary tumors and metastatic tumor manifestations.  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