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   4418篇
  免费   380篇
  国内免费   11篇
耳鼻咽喉   79篇
儿科学   115篇
妇产科学   46篇
基础医学   630篇
口腔科学   66篇
临床医学   506篇
内科学   742篇
皮肤病学   71篇
神经病学   511篇
特种医学   201篇
外国民族医学   1篇
外科学   740篇
综合类   38篇
一般理论   2篇
预防医学   341篇
眼科学   97篇
药学   306篇
中国医学   5篇
肿瘤学   312篇
  2024年   9篇
  2023年   67篇
  2022年   91篇
  2021年   243篇
  2020年   146篇
  2019年   212篇
  2018年   238篇
  2017年   170篇
  2016年   171篇
  2015年   202篇
  2014年   243篇
  2013年   272篇
  2012年   371篇
  2011年   357篇
  2010年   204篇
  2009年   175篇
  2008年   235篇
  2007年   217篇
  2006年   191篇
  2005年   124篇
  2004年   142篇
  2003年   89篇
  2002年   78篇
  2001年   20篇
  2000年   23篇
  1999年   20篇
  1998年   35篇
  1997年   29篇
  1996年   21篇
  1995年   18篇
  1994年   15篇
  1993年   15篇
  1992年   29篇
  1991年   34篇
  1990年   27篇
  1989年   27篇
  1988年   29篇
  1987年   18篇
  1986年   19篇
  1985年   28篇
  1984年   22篇
  1983年   17篇
  1982年   15篇
  1981年   17篇
  1979年   10篇
  1978年   7篇
  1976年   7篇
  1975年   9篇
  1973年   6篇
  1971年   6篇
排序方式: 共有4809条查询结果,搜索用时 15 毫秒
1.
2.

Background

Current blunt cerebrovascular injury (BCVI) grading grossly differentiates injury characteristics such as luminal stenosis (LS) and aneurysmal disease. The effect of increasing degree of LS beyond the current BCVI grading scale on stroke formation is unknown.

Study Design

BCVI over a 3-year period were retrospectively reviewed. To investigate influence of LS beyond the BCVI grading scale within aneurysmal and non-aneurysmal BCVI, grade 2 BCVI were subdivided into BCVI with ≥ 25% and ≤ 50% LS and BCVI with > 50% and ≤ 99% LS. Grade 3 BCVI were subdivided into BCVI with pseudoaneurysm (PSA) without LS and BCVI with PSA and LS. We hypothesized increased LS beyond the current BCVI grade distinctions would be associated with higher rates of stroke formation.

Results

312 BCVI were included, of which 140 were carotid BCVI and 172 vertebral BCVI. Sixteen carotid BCVI underwent endovascular intervention (EI) and 19 suffered a stroke. In carotid BCVI stroke rates increased sequentially with BCVI grade except in grade 3. There was a stroke rate of 12% in grade 1 carotid BCVI, 18% in grade 2, 6% in grade 3, and 31% in grade 4. In subgroup analysis for grade 2 carotid BCVI, BCVI with > 50% and ≤ 99% LS had higher rates of stroke (22% vs. 15%, p?=?0.44) than BCVI with ≥ 25% and ≤ 50% LS. In subgroup analysis of grade 3 carotid BCVI, BCVI with PSA and LS had higher rates of stroke (9% vs. 4%, p?=?0.48) than BCVI with PSA without LS. Higher rates of EI in grade 2 carotid BCVI with > 50% and ≤ 99% LS (22% vs. 5%, p?=?0.14) and grade 3 carotid BCVI with PSA and LS (35% vs. 4%, p?=?0.01) were noted in subgroup analysis.

Conclusion

Higher percentage LS beyond the currently used BCVI grading scale has a non-significantly increased rate of stroke in both aneurysmal and non-aneurysmal BCVI. Grade 3 BCVI with PSA and LS seems to be a high-risk subgroup. Use of EI confounds modern measurement of stroke risk in higher LS BCVI.  相似文献   
3.
ObjectivesCocaine is the second most frequently used illicit drug worldwide (after cannabis), and cocaine use disorder (CUD)-related deaths increased globally by 80% from 1990 to 2013. There is yet to be a regulatory-approved treatment. Emerging preclinical evidence indicates that deep brain stimulation (DBS) of the nucleus accumbens may be a therapeutic option. Prior to expanding the costly investigation of DBS for treatment of CUD, it is important to ensure societal cost-effectiveness.AimsWe conducted a threshold and cost-effectiveness analysis to determine the success rate at which DBS would be equivalent to contingency management (CM), recently identified as the most efficacious therapy for treatments of CUDs.Materials and MethodsQuality of life, efficacy, and safety parameters for CM were obtained from previous literature. Costs were calculated from a societal perspective. Our model predicted the utility benefit based on quality-adjusted life-years (QALYs) and incremental-cost-effectiveness ratio resulting from two treatments on a one-, two-, and five-year timeline.ResultsOn a one-year timeline, DBS would need to impart a success rate (ie, cocaine free) of 70% for it to yield the same utility benefit (0.492 QALYs per year) as CM. At no success rate would DBS be more cost-effective (incremental-cost-effectiveness ratio <$50,000) than CM during the first year. Nevertheless, as DBS costs are front loaded, DBS would need to achieve success rates of 74% and 51% for its cost-effectiveness to exceed that of CM over a two- and five-year period, respectively.ConclusionsWe find DBS would not be cost-effective in the short term (one year) but may be cost-effective in longer timelines. Since DBS holds promise to potentially be a cost-effective treatment for CUDs, future randomized controlled trials should be performed to assess its efficacy.  相似文献   
4.
5.
6.
7.
8.
9.
This study looked at the prevalence of panic attacks and panic disorder in a British population. Three thousand people (aged 18-65) registered with a Leicester general practice were sent a postal questionnaire which screened for panic attacks. Where appropriate this was followed by a diagnostic interview. Preliminary results are reported for the first 1500 subjects sampled. Panic attacks are a common experience in the study population (7.5% of responders experienced them around the time of the interview). Panic disorder was diagnosed in about 3% of responders.  相似文献   
10.
Seventeen patients were entered into a Phase I/II trial of concurrent hyperfractionated radiation therapy (7,440 cGy total dose; 120 cGy b.i.d.) combined with constant infusion of 5-fluorouracil (5-FU) (1,000 mg/m2/24 hours for 72 hours) and cisplatin (DDP) (50 mg/m2) for a total of three cycles. Thirteen patients had Stage IV disease; three, Stage III disease; and one, Stage II hypopharyngeal disease. Thirteen of 17 patients had positive cervical lymph nodes, and the mean size of the largest lymph node was 5.5 x 5.1 cm. The patients were not treated with planned adjunctive surgery except for one patient who had a radical neck dissection for massive, rapidly growing cervical adenopathy, which recurred promptly within 1 month before the initiation of protocol therapy. After the initial six patients were entered, mitomycin-C (Mito 8 mg/m2) was added during the second cycle. All the patients completed the planned course of radiotherapy with a median dose of 7,440 cGy and a mean dose of 7,248 cGy except for two patients who died--one from toxicity and the other, suicide. The predominant toxicity was mucositis, which was grade 3/4 in 11 of 15 patients, resulting in an average interruption of radiation therapy of 12 days. Weight loss was significant and was on the average 12% of baseline weight. Hematological toxicity was mild in the 5-FU/DDP group (only one grade 3 toxicity of six) and severe in the 5-FU/DDP/Mito-treated patients (five of eight patients having grade 3/4 toxicity including one leukopenic pneumonitis death). Additional toxicity included one parapharyngeal cellulitis, which responded to antibiotics. Noncompliance with the complex regimen was only seen in three patients. One patient refused b.i.d. radiation therapy, and one patient refused further chemotherapy after the first cycle. Additionally, one patient who had a severe ethanol withdrawal reaction during the first cycle of 5-FU/DDP did not receive further chemotherapy. The complete response rate of both primary site and neck by the protocol regimen alone was 71%. However, two patients, one from each group, did undergo salvage neck dissection, and the locoregional control is currently 73%, with a mean follow-up time of 18.4 months. The feasibility of combining hyperfractionated radiation therapy with aggressive concurrent chemotherapy was demonstrated. The response and local control rate justifies the added toxicity of concurrent chemotherapy and radiation therapy.  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