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   19490篇
  免费   1112篇
  国内免费   151篇
耳鼻咽喉   254篇
儿科学   526篇
妇产科学   668篇
基础医学   2136篇
口腔科学   536篇
临床医学   1611篇
内科学   3883篇
皮肤病学   380篇
神经病学   932篇
特种医学   726篇
外国民族医学   11篇
外科学   3431篇
综合类   355篇
现状与发展   2篇
一般理论   11篇
预防医学   1685篇
眼科学   548篇
药学   1776篇
中国医学   139篇
肿瘤学   1143篇
  2024年   18篇
  2023年   254篇
  2022年   787篇
  2021年   1134篇
  2020年   617篇
  2019年   763篇
  2018年   1030篇
  2017年   600篇
  2016年   636篇
  2015年   645篇
  2014年   911篇
  2013年   1056篇
  2012年   1542篇
  2011年   1693篇
  2010年   958篇
  2009年   696篇
  2008年   981篇
  2007年   992篇
  2006年   911篇
  2005年   864篇
  2004年   753篇
  2003年   692篇
  2002年   618篇
  2001年   157篇
  2000年   120篇
  1999年   108篇
  1998年   86篇
  1997年   77篇
  1996年   73篇
  1995年   70篇
  1994年   63篇
  1993年   55篇
  1992年   60篇
  1991年   65篇
  1990年   64篇
  1989年   51篇
  1988年   52篇
  1987年   52篇
  1986年   41篇
  1985年   43篇
  1984年   43篇
  1983年   42篇
  1982年   37篇
  1981年   29篇
  1980年   25篇
  1978年   16篇
  1977年   14篇
  1976年   17篇
  1973年   23篇
  1966年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
OBJECTIVE: To determine if there is national variation in regimens of upper urinary tract surveillance in patients with primary bladder cancer. METHODS: A questionnaire was sent to 470 consultant urologists from a British Association of Urological Surgeons list in the UK; 301 anonymous replies were received. Two replies were incomplete and therefore the results of 299 questionnaires (64%) were analysed. RESULTS: Of the 299 surgeons, 19 (6%) use no form of upper urinary tract surveillance; 162 (54%) use surveillance in selected patients, i.e. those with carcinoma in situ (47%), multiple bladder tumours at first presentation (39%) and after cystectomy (70%), and 118 (39%) use upper tract surveillance on all patients with a history of bladder cancer. The median (range) screening interval was 24 (12-60) months and surveillance continued for a median of 10 (2 to indefinite) years, continuing for an indefinite period in 33%. CONCLUSIONS: Most urologists use upper tract surveillance in patients with bladder cancer but there is wide variation in the duration and interval for which it continues, and in the type of patient selected for surveillance. Some patients at high risk of upper tract tumour are not being screened. Asymptomatic upper tract tumours may not be diagnosed because the intervals between surveillance are too long, and the duration for which it continues inadequate. There is a need for multidisciplinary national guidelines to reduce variation in practice.  相似文献   
122.
123.
Auditory verbal hallucinations (AVH) in patients with schizophrenia are associated with abnormal hyperactivity in the left temporo-parietal junction (TPJ) and abnormal connectivity between frontal and temporal areas. Recent findings suggest that fronto-temporal transcranial Direct Current stimulation (tDCS) with the cathode placed over the left TPJ and the anode over the left prefrontal cortex can alleviate treatment-resistant AVH in patients with schizophrenia. However, brain correlates of the AVH reduction are unclear. Here, we investigated the effect of tDCS on the resting-state functional connectivity (rs-FC) of the left TPJ. Twenty-three patients with schizophrenia and treatment-resistant AVH were randomly allocated to receive 10 sessions of active (2 mA, 20min) or sham tDCS (2 sessions/d for 5 d). We compared the rs-FC of the left TPJ between patients before and after they received active or sham tDCS. Relative to sham tDCS, active tDCS significantly reduced AVH as well as the negative symptoms. Active tDCS also reduced rs-FC of the left TPJ with the left anterior insula and the right inferior frontal gyrus and increased rs-FC of the left TPJ with the left angular gyrus, the left dorsolateral prefrontal cortex and the precuneus. The reduction of AVH severity was correlated with the reduction of the rs-FC between the left TPJ and the left anterior insula. These findings suggest that the reduction of AVH induced by tDCS is associated with a modulation of the rs-FC within an AVH-related brain network, including brain areas involved in inner speech production and monitoring.Key words: resting state, brain stimulation, fMRI, temporal cortex  相似文献   
124.
A case of post-traumatic arachnoiditis ossificans of the cauda equina is reported. The lesion is a rare pathological entity usually confined to the thoracic and high lumbar regions that can cause progressive spinal cord and cauda equine compression. The pathophysiology and therapeutic strategy of this rare entity are still controversial.  相似文献   
125.

Background

Laparoscopic hernia repair accounts for 10% of all hernia surgery. Potential benefits include reduction in postoperative pain, rapid recovery, lower recurrence rate, and fewer complications. The outcomes of health-related quality of life and patient perspective after hernia repair are our aim.

Methods

Consecutive patients treated for unilateral uncomplicated groin hernia were enrolled after evaluation for inclusion. Participants were randomly distributed to receive either laparoscopic transabdominal preperitoneal repair (TAPP) (group I) or Lichtenstein repair (group II). Operative and postoperative complications, operative time, hospital stay, and late complications were assessed early postoperatively, at 4?weeks, and every 6?months thereafter. Quality of life was assessed using Short Form-36 questionnaire in the first visit (after 4?weeks).

Results

One hundred and eighty-five patients of unilateral uncomplicated groin hernia were included; 88 patients (group I) were treated by TAPP, and 97 patients were treated by Lichtenstein repair (group II) with median follow-up of 17.9?months. Mean hospital stay, mean operative time, operative and postoperative complications were similar in the two groups. Quality of life showed better and significant outcomes in group I for physical function (p?≤?0.001), role physical (p?≤?0.011), bodily pain (p?≤?0.017), general health (p?≤?0.047), and total physical health (p?≤?0.008). However, mental health showed no statistical significance in its four scales, but with better outcomes in group I. Total quality outcomes showed significantly better outcomes in group I (p?≤?0.031).

Conclusions

TAPP hernia repair technique is a safe technique with low complication rate, less postoperative body pain, and better quality-of-life outcomes compared with open technique, being well accepted from the patient’s perspective for quality of life.  相似文献   
126.
Despite the extensive use of pectoralis major flaps in reconstructive surgery, certain pectoralis major musculocutaneous flaps may suffer from partial distal necrosis. The aim of the present study was to investigate the origin, length, and external diameter of its arterial pedicles to provide an anatomical basis for alternative techniques in reconstructive surgery. Thirty pectoral region specimens, pertaining to 14 fresh human adult cadavers and one stillbirth, were dissected, after retrograde injection of the brachial artery with red latex in pursuit of this aim. The thoracoacromial trunk (TAT) was the main nourishing vessel, arising from the first and the second parts of the axillary artery in 60% and 40%, respectively. The proximal segment was constantly supplied by the clavicular and the deltoid branches of the TAT, supplemented by its pectoral branch in 30% and the superior thoracic artery in 23.3%. The distal segment was constantly supplied by the lateral perforating branches of the anterior intercostal arteries and the perforating branches of the internal thoracic artery. The pectoral branch of both the TAT (P-TAT), and the axillary artery (PA) and the lateral thoracic artery participated in 90%, 66.7%, and 40%, respectively. Additionally, an arterial pedicle, from the arterial plexus inside the pectoralis minor muscle, was observed in 4/30 (13.3%). The clavicular and pectoral branches of the TAT are reliable pedicles for raising the proximal and distal segments of muscle flaps, respectively. The pectoral branch of axillary artery may be an alternative pedicle in the absence of P-TAT.  相似文献   
127.
128.
BackgroundLong-term follow-up has substantiated the colon as a durable and highly acceptable esophageal substitute. Exposure of colonic conduit to gastric acid may lead to histopathologic changes in the form of chronic inflammation.Materials/MethodsThirty children with esophageal replacement were studied from 2 to 12 years (mean, 5.20 years) postoperatively. All cases underwent upper gastrointestinal tract endoscopy to evaluate the gross appearance of colonic conduit mucosa, and punch biopsies were taken from upper and lower junctions of the conduit. All biopsies were submitted to histopathologic examination.ResultsEndoscopic findings were comparable with normal regarding the gross appearance of colonic mucosa in both upper and lower junctions (25 cases/83.3%). Some abnormalities were seen including cervical anastomosis stricture (2 cases/6.7%), redundancy (3 cases/10%), mucosal ulcer in the lower residual esophagus (1 case/3.3%), and hyperemia (3 cases/10%). Pathologic changes were minimal regarding the change in position of the colon to a thoracic organ during follow-up. Most of the cases were normal (22cases/73.3%). Seven cases (23.4%) showed mild chronic nonspecific inflammation of the colonic mucosa, whereas only 1 case (3.3%) showed mildly active inflammation of colonic mucosa.ConclusionThe use of the colon for esophageal replacement showed that no significant pathologic changes affecting its function as a conduit because its mucosa showed no significant change in response to gastric acid reflux in long-term follow-up and can be further protected by an antireflux procedure.  相似文献   
129.
INTRODUCTIONSeveral congenital anomalies of the spleen have been reported. The polysplenia is a rare anomaly in which the normal spleen is replaced with two or more smaller spleens. The wandering spleen is another anomaly resulting from the laxity of the splenic ligaments. The concomitance of both anomalies is very rare.PRESENTATION OF A CASEA 22-year old female patient presented with intermittent left hypochondrial pain for more than a year. After a thorough examination of the patient, she only had bilateral accessory nipples. Routine laboratory investigations were all normal. An abdominal ultrasound U/S scan was unremarkable except for a ptotic spleen. with a large splenule 5 cm × 3 cm located near the fundus of the stomach. These findings were confirmed by a CT scan. A decision for a surgical intervention was then made, and the laparoscopic approach was chosen which revealed the condition. Laparoscopic removal of the wandering part was executed. The patient discharged on the first post-operative day.DISCUSSIONThe decision making in cases of wandering spleen is not always the same. The association of a wandering spleen with polysplenia is an asset to the surgical decision, along with the age of the patient.CONCLUSIONThe laparoscopic approach is an important tool in the diagnosis and management of wandering spleen. The diagnosis of polysplenic anomaly could provide a guidance for the surgical strategy in patients with wandering spleen.  相似文献   
130.

Introduction

Duodenal gastrointestinal stromal tumors (GISTs) are rare but still represent approximately 30?% of primary duodenal tumors. This study aimed to audit the feasibility and oncological outcomes of limited duodenal resection in patients with primary nonmetastatic duodenal GIST.

Methods

Twelve patients who underwent surgery at our institution since 2002 were prospectively followed up. The duodenal GISTs were located in the first (n?=?3), second (n?=?1), third (n?=?3), and fourth of duodenum (n?=?1). Involving both D1/D2 (n?=?2), D2/D3 (n?=?1), and D3/D4 (n?=?1). The primary endpoint for this analysis was disease-free survival.

Results

The commonest presentation was melena and anemia (83?%). All the patients underwent limited resection; six wedge resections with primary closures and six segmental resections with end-to-end anastomosis. The median tumor size was 8?cm (range, 5?C16?cm). According to Fletcher scale, two GISTs were low risk, while 10 patients were intermediate and high risk. The latter received adjuvant therapy. All the patients had a complete resection with no postoperative mortality. One patient had three liver metastases 4?months after limited resection and had partial hepatectomy. After median follow-up of 45 (15?C78)?months, all patients are alive and disease free.

Conclusion(s)

When technically feasible, limited resection should be considered a reliable and curative option for duodenal GIST achieving satisfactory disease-free survival. The technical feasibility is guided by the tumor size, possible adjacent organ involvement, and its exact anatomical location.  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