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   1705篇
  免费   83篇
  国内免费   8篇
耳鼻咽喉   12篇
儿科学   159篇
妇产科学   7篇
基础医学   136篇
口腔科学   34篇
临床医学   104篇
内科学   430篇
皮肤病学   25篇
神经病学   102篇
特种医学   104篇
外科学   313篇
综合类   96篇
预防医学   81篇
眼科学   17篇
药学   100篇
中国医学   2篇
肿瘤学   74篇
  2023年   6篇
  2022年   11篇
  2021年   29篇
  2020年   15篇
  2019年   31篇
  2018年   33篇
  2017年   17篇
  2016年   31篇
  2015年   32篇
  2014年   46篇
  2013年   43篇
  2012年   68篇
  2011年   89篇
  2010年   73篇
  2009年   69篇
  2008年   75篇
  2007年   74篇
  2006年   101篇
  2005年   46篇
  2004年   62篇
  2003年   53篇
  2002年   45篇
  2001年   55篇
  2000年   69篇
  1999年   59篇
  1998年   63篇
  1997年   34篇
  1996年   43篇
  1995年   29篇
  1994年   26篇
  1993年   26篇
  1992年   17篇
  1991年   22篇
  1990年   16篇
  1989年   25篇
  1988年   34篇
  1987年   24篇
  1986年   17篇
  1985年   29篇
  1984年   15篇
  1983年   23篇
  1982年   15篇
  1981年   12篇
  1980年   10篇
  1979年   9篇
  1978年   8篇
  1977年   9篇
  1976年   14篇
  1974年   7篇
  1973年   7篇
排序方式: 共有1796条查询结果,搜索用时 390 毫秒
991.
Despite inception over 15 years ago and over 3000 completed procedures, laparoscopic liver resection has remained mainly in the domain of selected centers and enthusiasts. Requirement of extensive open liver resection(OLR) experience, in-depth understanding of anatomy and considerable laparoscopic technical expertise may have delayed wide application. However healthy scepticism of its actual benefits and presence of a potential publication bias; concern about its safety and technical learning curve, are probably equally responsible. Given that a large proportion of our work, at least in transplantation is still OLR, we have attempted to provide an entirely unbiased, mature opinion of its pros and cons in the current invited review. We have dividedthis review into two sections as we believe they merit separate attention on technical and ethical grounds. The first part deals with laparoscopic liver resection(LLR) in patients who present with benign or malignant liver pathology, wherein we have discussed its overall outcomes; its feasibility based on type of pathology and type of resection and included a small section on application of LLR in special scenarios like cirrhosis. The second part deals with the laparoscopic living donor hepatectomy(LDH) experience to date, including its potential impact on transplantation in general. Donor safety, graft outcomes after LDH and criterion to select ideal donors for LLR are discussed. Within each section we have provided practical points to improve safety in LLR and attempted to reach reasonable recommendations on the utilization of LLR for units that wish to develop such a service.  相似文献   
992.

Background

Congential heart disease (CHD) is an important cause of morbidity and mortality in patients with Down’s syndrome (DS).

Methods

All patients with DS seen at the Sudan Heart Centre from July 2004 to November 2007 were included in the study. All patients were examined clinically and echocardiographically, and cardiac catheterisation was carried out in selected patients. All patients were prospectively followed up.

Results

In the study period, 1 566 patients were evaluated for heart disease. Of these, 80 patients with DS were identified (5%). Their ages ranged from 15 days to 18 years. Cardiac abnormalities included atrioventricular septal defect (AVSD) in 38 patients (48%), with the complete form in 25, a partial form in seven, AVSD with intact atrial septum in one, and complex AVSD in four patients. In one patient there was AVSD with right atrioventricular valve malformation with severe valve regurgitation and functional pulmonary atresia. The other main lesions were ventricular septal defect (VSD) in 19 patients (23%) and tetralogy of Fallot (TOF) in five (6%).Cardiac catheterisation was done in four patients with AVSD to measure pulmonary pressures and resistance, and in one patient with patent ductus arteriosus for device closure. Ten percent of the patients had Eisenmenger’s syndrome at the time of presentation. Only 15% of patients who were in need of surgery were operated on; all had an uneventful postoperative course and a good outcome at a mean follow-up period of one year

Conclusion

The pattern of CHD in Sudanese patients with DS was comparable with that in the literature, including the rare occurrence of AVSD with intact atrial septum. In addition, we described an unreported association with right atrioventricular valve malformation. Although there was a significant delay in diagnosis and surgery, surgical results and short-term follow up were good.  相似文献   
993.
Hansen''s disease is a chronic infection caused by Mycobacterium leprae. Current therapy for this disease is with the WHO recommended Multi Drug Therapy (MDT) with DDS, rifampicin and clofazimine. Hyper Baric Oxygen Therapy (HBOT) has been used to treat many medical conditions including infections with a great deal of success. It''s efficacy on various species of mycobacteria and other bacteria have been studied in vitro and in vivo and it is found to be an effective antimicrobial agent under specified conditions. HBOT has been used to treat Hansen''s disease, including drug resistant lepromatous leprosy cases with good results. However there is a paucity of literature on this form of therapy. We have treated twenty cases of Hansen''s disease with HBOT prior to exhibiting MDT as per the WHO schedule. There has been a marked regression in skin signs especially decrease in erythema and flattening of raised lesions. This correlated well with the histopathological picture which showed a reduction in the inflammatory exudate.KEY WORDS: Hansen''s Disease, HBOT, Hyperbaric Oxygen, Leprosy, Therapy  相似文献   
994.
Abstract: Aim:  The purpose of this research was to evaluate molar furcation entrances and the width of periodontal curette blades used in periodontal instrumentation.
Materials and methods:  One hundred extracted molars (50 upper and 50 lower) were analysed. The furcation entrances were measured using orthodontic wires of different predetermined diameters: 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 mm. McCall 17–18, Gracey 5–6 and Gracey 5–6 mini-five curette blades were measured at their anterior (AT), middle (MT) and posterior (PT) thirds by a single trained investigator, through the use of a digital caliper.
Results:  The results showed significant differences ( P  < 0.0001) in relation to furcation entrances. The buccal upper molar furcations showed the narrowest dimensions. In relation to the blade diameter, significant differences among the instruments were found for their MT and PT ( P  < 0.0001), but not for the AT ( P  = 0.183). Significant differences were found among curette manufacturers. Nineteen per cent of evaluated furcations presented entrances <0.60 mm and 75% of the blades at their AT presented width >0.60 mm.
Conclusions:  These findings demonstrated that some molar furcation entrances could not be adequately instrumented with the tested curettes. The use of other hand instruments, such as periodontal files, rotating instruments and ultrasonic devices should be taken into consideration during periodontal therapy.  相似文献   
995.

Objective

To assess interrater agreement based on majority voting in visual scoring of neonatal seizures.

Methods

An online platform was designed based on a multicentre seizure EEG-database. Consensus decision based on ‘majority voting’ and interrater agreement was estimated using Fleiss’ Kappa. The influences of different factors on agreement were determined.

Results

1919 Events extracted from 280 h EEG of 71 neonates were reviewed by 4 raters. Majority voting was applied to assign a seizure/non-seizure classification. 44% of events were classified with high, 36% with moderate, and 20% with poor agreement, resulting in a Kappa value of 0.39. 68% of events were labelled as seizures, and in 46%, all raters were convinced about electrographic seizures. The most common seizure duration was <30 s. Raters agreed best for seizures lasting 60–120 s. There was a significant difference in electrographic characteristics of seizures versus dubious events, with seizures having longer duration, higher power and amplitude.

Conclusions

There is a wide variability in identifying rhythmic ictal and non-ictal EEG events, and only the most robust ictal patterns are consistently agreed upon. Database composition and electrographic characteristics are important factors that influence interrater agreement.

Significance

The use of well-described databases and input of different experts will improve neonatal EEG interpretation and help to develop uniform seizure definitions, useful for evidence-based studies of seizure recognition and management.  相似文献   
996.

Background  

Although reports on band erosion management after laparoscopic adjustable gastric banding (LAGB) agree that in most cases the affected band will need to be removed, there is no consensus on the technique of removal. We report a minimalistic, laparoscopic technique which is safe and avoids management delay.  相似文献   
997.
998.
999.
We present an unusual case of renal cell cancer(RCC) which relapsed with duodenal metastasis and unveiled itself by gastrointestinal(GI) bleeding.An 80-year old Caucasian gentleman with history of renal cell cancer status post nephrectomy 11 mo previously,presented with syncope and melena.Computed tomography scan of the abdomen revealed heterogeneous soft tissue mass in the right nephrectomy bed invading the duodenum.Upper GI endoscopic biopsy confirmed the presence of recurrent renal cell cancer.However,due to extensive metastatic disease,the patient was placed on palliative chemotherapy as surgical options were ruled out.Our case report reiterates the fact that renal cell carcinoma can recur with gastrointestinal manifestations and,although a rarity,it should be considered in a patient with a history of malignancy who presents with these symptoms.  相似文献   
1000.
Okwo-Bele JM  Cherian T 《Vaccine》2011,29(Z4):D74-D79
Since the mid-1970s, the widespread establishment and implementation of the Expanded Programme on Immunization (EPI) has led to remarkable achievements in controlling vaccine preventable diseases worldwide. Today, more children than ever are being reached with immunization; interruption of poliomyelitis transmission has occurred in most countries; mortality due to measles, tetanus, diphtheria and pertussis has been reduced to record low levels. In addition, increasing numbers of vaccines are being used for infants and older age persons, such as vaccines against hepatitis A and hepatitis B, Haemophilus influenzae type b, rotavirus, pneumococcus, meningococcus, human papilloma virus (HPV) and varicella. The design of EPI reflects in large part the experience accumulated during the implementation of the intensified campaign for smallpox eradication during the period 1966-1977. At that time, the existing health infrastructure and network was found inadequate to reach most individuals with community wide immunization programmes in most countries. Thus, efforts were made to train dedicated health personnel and allocate specific resources for programme coordination and implementation. With the establishment of EPI, there was a gradual shift in emphasis from vaccination campaign strategies using mobile teams to the delivery of immunization services as part of routine health services of health facilities. Both the campaign and the outreach strategies are nevertheless required to reach those segments of the population not reached by the routine health services and to accelerate the achievement of disease control initiatives such as polio eradication and measles elimination. Whilst the campaign for smallpox eradication was set up as special and time-limited effort, the EPI requires long-term sustainable approaches to protect new cohorts of susceptible persons with vaccination and monitor trends and progress towards disease control with high quality surveillance.  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