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   5038篇
  免费   385篇
  国内免费   60篇
耳鼻咽喉   41篇
儿科学   144篇
妇产科学   210篇
基础医学   640篇
口腔科学   74篇
临床医学   427篇
内科学   1305篇
皮肤病学   113篇
神经病学   618篇
特种医学   161篇
外科学   453篇
综合类   6篇
一般理论   3篇
预防医学   295篇
眼科学   54篇
药学   340篇
中国医学   9篇
肿瘤学   590篇
  2024年   18篇
  2023年   141篇
  2022年   284篇
  2021年   431篇
  2020年   250篇
  2019年   275篇
  2018年   320篇
  2017年   203篇
  2016年   233篇
  2015年   260篇
  2014年   264篇
  2013年   314篇
  2012年   413篇
  2011年   348篇
  2010年   189篇
  2009年   139篇
  2008年   231篇
  2007年   240篇
  2006年   200篇
  2005年   166篇
  2004年   143篇
  2003年   132篇
  2002年   100篇
  2001年   16篇
  2000年   10篇
  1999年   21篇
  1998年   24篇
  1997年   15篇
  1996年   12篇
  1995年   11篇
  1994年   15篇
  1993年   9篇
  1992年   3篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1988年   7篇
  1987年   4篇
  1986年   6篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   3篇
  1981年   3篇
  1979年   4篇
  1971年   1篇
  1970年   2篇
  1968年   2篇
  1967年   3篇
  1966年   1篇
排序方式: 共有5483条查询结果,搜索用时 15 毫秒
81.
Impaired amyloid beta (Aβ) metabolism is currently considered central to understand the pathophysiology of Alzheimer's disease (AD). Measurements of cerebrospinal fluid Aβ levels remain the most useful marker for diagnostic purposes and to individuate people at risk for AD. Despite recent advances criticized the direct role in neurodegeneration of cortical neurons, Aβ is considered responsible for synaptopathy and impairment of neurotransmission and therefore remains the major trigger of AD and future pharmacological treatment remain Aβ oriented. However, experimental and clinical findings showed that Aβ peptides could have a wider range of action responsible for cell dysfunction and for appearance of clinico‐pathological entities different from AD. Such findings may induce misunderstanding of the real role played by Aβ in AD and therefore strengthen criticism on its centrality and need for CSF measurements. Aim of this review is to discuss the role of CSF Aβ levels in light of experimental, clinical pathologic, and electrophysiological results in AD and other pathological entities to put in a correct frame the value of Aβ changes.  相似文献   
82.
Brentuximab vedotin (BV) shows a high overall response rate (ORR) in relapsed/refractory (R/R) Hodgkin lymphoma (HL) after autologous transplant (ASCT). The aim of this multicenter study, conducted in nine Hematology Departments of Rete Ematologica Pugliese, was to retrospectively evaluate the efficacy and safety of BV as salvage therapy and as bridge regimen to ASCT or allogeneic transplant (alloSCT) in R/R HL patients. Seventy patients received BV. Forty-five patients (64%) were treated with BV as bridge to transplant:16 (23%) patients as bridge to ASCT and 29 (41%) as bridge to alloSCT. Twenty-five patients (36%), not eligible for transplant, received BV as salvage treatment. The ORR was 59% (CR 26%). The ORR in transplant naïve patients was 75% (CR 31%). In patients treated with BV as bridge to alloSCT, the ORR was 62% (CR 24%). In a multivariate analysis, the ORR was lower in refractory patients (p?<?0.005). The 2y-OS was 70%. The median PFS was 17 months. Ten of the 16 (63%) naïve-transplant patients received ASCT, with 50% in CR before ASCT. In the 29 patients treated with BV as bridge to alloSCT, 28 (97%) proceeded to alloSCT with 25% in CR prior to alloSCT. The most common adverse events were peripheral neuropathy (50%), neutropenia (29%) and anemia (12%). These data suggest that BV is well tolerated and very effective in R/R HL, producing a substantial level of CR. BV may also be a key therapeutic agent to achieve good disease control before transplant, improving post- transplant outcomes, also in refractory and heavily pretreated patients, without significant overlapping toxicities with prior therapies.  相似文献   
83.

Background and study aims

Several studies have demonstrated the superiority of proton-pump inhibitors (PPIs) in resolving erosive gastro-oesophageal reflux disease (GORD). However, this first line of treatment can fail to control symptoms in around 30% of cases, especially in the presence of non-erosive GORD. In situations where the first line of treatment fails, there is a lack of concordance regarding the best strategy to apply. This study presents a systematic review of the trials which have tested second-line treatments after PPI failure.

Methods

The study was conducted according to the PRISMA statement. The systematic review included medical trials written in English which were published between 2000 and 2016 and were retrieved from PubMed and Scopus using the keywords ‘PPI-resistant gastro-oesophageal reflux’, ‘alginate AND gastro-oesophageal reflux’, ‘hyaluronic acid AND gastro-oesophageal reflux’, ‘prokinetics AND gastro-oesophageal reflux’, ‘sucralfate AND gastro-oesophageal reflux’ and ‘baclofen AND gastro-oesophageal reflux’.

Results

Ten randomised and non-randomised studies were included, which included 1515 patients of both sexes (mean age?=?49.19?years, age range?=?18–85, males?=?700; 46.2%).

Conclusions

A personalised choice of the best treatment for PPI-resistant GORD should be based on the results of an upper endoscopy and pH/MII monitoring. For patients in situations where the first line of treatment fails, we encourage the execution of trials for testing double doses of PPIs against alternative medicaments.  相似文献   
84.
Background and hypothesis: Antiarrhythmic drugs are widely used for treatment of atrial fibrillation (AF) and restoration off sinus rhythm. This prospective, randomized, and controlled study compared the efficiency and safety of propafenone versus procainamide for the treatment of acute AF. Methods: In all, 117 patients (55 women, 62 men, mean age 64.2 ± 13 years, median 63 years) who presented with AF were included in the study. Exclusion criteria were signs or symptoms of heart failure on physical examination, recent myocardial infarction or cardiac surgery, cardiogenic shock, or hypotension. Forty-one patients spontaneously recovered sinus rhythm; the remaining 76 patients were randomized to receive propafenone or procainamide. Propafenone was given at a dose of 2 mg/kg body weight intravenously (IV) over 30 min. Patients randomized to receive procainamide received a bolus of 100 mg IV administered every 5 min up to a maximum dose of 1 g. The clinical characteristics of the two groups were comparable. Results: The number of patients who recovered sinus rhythm after the treatment was larger in the procainamide-treated group (Group 1) (69.5%) than in the propafenone-treated group (Group 2) (48.7%); p < 0.05. The time required for cardioversion was significantly lower in Group 1 (mean 4.1 ± 1.3 h). than in Group 2 patients (mean 7.3 ± 2.6 h) (p<0.01). Conclusion: In the present study, procainamide was more effective than propafenone for the treatment of AF of short duration.  相似文献   
85.
86.
87.
AIM: To investigate the role of laparoscopy in diagnosis and treatment of intra abdominal infections.METHODS: A systematic review of the literature was performed including studies where intra abdominal infections were treated laparoscopically.RESULTS: Early laparoscopic approaches have become the standard surgical technique for treating acute cholecystitis. The laparoscopic appendectomy has been demonstrated to be superior to open surgery in acute appendicitis. In the event of diverticulitis, laparoscopic resections have proven to be safe and effective procedures for experienced laparoscopic surgeons and may be performed without adversely affecting morbidity and mortality rates. However laparoscopic resection has not been accepted by the medical community as the primary treatment of choice. In high-risk patients, laparoscopic approach may be used for exploration or peritoneal lavage and drainage. The successful laparoscopic repair of perforated peptic ulcers for experienced surgeons, is demonstrated to be safe and effective. Regarding small bowel perforations, comparative studies contrasting open and laparoscopic surgeries have not yet been conducted. Successful laparoscopic resections addressing iatrogenic colonic perforation have been reported despite a lack of literature-based evidence supporting such procedures. In post-operative infections, laparoscopic approaches may be useful in preventing diagnostic delay and controlling the source.CONCLUSION: Laparoscopy has a good diagnostic accuracy and enables to better identify the causative pathology; laparoscopy may be recommended for the treatment of many intra-abdominal infections.  相似文献   
88.
PURPOSE: The following study was done to evaluate the therapeutic value of radiotherapy as an adjunct to surgery for rectal cancer patients. METHODS: One-hundred twenty-four patients underwent curative resection by one surgeon (RC) from 1982 to 1991. Forty patients received combined preoperative and postoperative (sandwich) radiotherapy, 30 patients received postoperative radiotherapy, and 54 patients were treated by surgery alone. During the study period sandwich radiotherapy was primarily offered as a free treatment option for patients with tumors which were believed to be transmurally invasive, whereas postoperative radiotherapy was an alternative therapeutic option offered to patients with tumor classified as Dukes B and C at histopathologic examination. RESULTS: Operative mortality was 2 percent in the sandwich radiotherapy group vs. 7 percent in the surgery alone group. After a median follow-up of 60 months, the actuarial locoregional recurrence rate at five years was 3 percent for the sandwich radiotherapy group compared with 18 and 30 percent for the postoperative radiotherapy and surgery alone groups, respectively (P =0.019). A multivariate analysis using the Cox model confirmed the favorable independent influence of sandwich radiotherapy on local tumor control, especially in distal tumors. The therapeutic benefit of sandwich radiotherapy translated into increased survival in the low-rectum Dukes B subgroup of patients. The actuarial five-year survival rates were 86 percent, 50 percent, and 28 percent in the sandwich radiotherapy, postoperative radiotherapy and surgery alone groups, respectively (P =0.05). CONCLUSIONS: Preoperative radiotherapy has a significant effect on the prognosis of rectal cancer patients.  相似文献   
89.

Background

Growing evidence suggests that colorectal cancer (CRC) screening based on the fecal immunochemical test (FIT) reduces CRC incidence and surgical resection rates.

Aims

To compare trends in surgery for proximal and distal CRC among Italian regions at different stages of screening implementation.

Methods

From the National Hospital Discharge Database we selected hospitalizations with CRC resection of residents aged 50–74 years during 2002–2014, and computed surgery rates for the 8 most populous Italian regions with/without a screening program.

Results

In regions with screening, implemented around 2006–2007, the annual percent change (APC) of distal CRC resection was +1.7 (95% confidence interval ?1.0, 4.4) during 2002–2007 and ?9.1 (?10.6, ?7.7) during 2007–2014. No significant change was observed in regions without screening. The APC for proximal colon resection in regions with screening was +5.8 (2.5, 9.0) during 2002–2007 and ?4.1 (?5.8, ?2.4) during 2007–2014, while in regions without screening surgical rates increased through the whole study period. Compared to 2002, in 2014 distal CRC resection rates were greatly reduced in regions with screening, reaching values similar to proximal CRC resection.

Conclusion

Following the implementation of screening programs surgery rates steeply decreased, confirming the deep impact of FIT-based screening on the burden of CRC.  相似文献   
90.
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