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   4321篇
  免费   190篇
  国内免费   12篇
耳鼻咽喉   103篇
儿科学   192篇
妇产科学   210篇
基础医学   674篇
口腔科学   31篇
临床医学   259篇
内科学   970篇
皮肤病学   69篇
神经病学   382篇
特种医学   69篇
外科学   186篇
综合类   26篇
预防医学   368篇
眼科学   112篇
药学   577篇
中国医学   13篇
肿瘤学   282篇
  2024年   2篇
  2023年   24篇
  2022年   195篇
  2021年   302篇
  2020年   104篇
  2019年   134篇
  2018年   142篇
  2017年   129篇
  2016年   152篇
  2015年   153篇
  2014年   200篇
  2013年   283篇
  2012年   361篇
  2011年   371篇
  2010年   197篇
  2009年   147篇
  2008年   233篇
  2007年   304篇
  2006年   272篇
  2005年   255篇
  2004年   187篇
  2003年   184篇
  2002年   143篇
  2001年   12篇
  2000年   4篇
  1999年   3篇
  1998年   5篇
  1997年   10篇
  1996年   6篇
  1995年   4篇
  1992年   1篇
  1988年   1篇
  1981年   1篇
  1978年   1篇
  1977年   1篇
排序方式: 共有4523条查询结果,搜索用时 163 毫秒
61.
Purpose: To detect any improvement of awareness in prolonged disorders of consciousness in the long term.

Methods: A total of 34 patients with prolonged disorders of consciousness (27 vegetative state and seven minimally conscious state; 16 males; aged 21–73) were included in the study. All patients were initially diagnosed with vegetative/minimally conscious state on admission to our specialist neurological rehabilitation unit. Re-assessment was performed 2–16?years later using Coma Recovery Scale-Revised.

Results: Although remaining severely disabled, 32% of the patients showed late improvement of awareness evidenced with development of non-reflexive responses such as reproducible command following and localization behaviors. Most of the late recoveries occurred in patients with subarachnoid hemorrhage (5/11, 45.5%). The ages of patients within the late recovery group (Mean?=?45, SD?=?11.4) and non-recovery group (Mean?=?43, SD?=?15.5) were not statistically different (p?=?0.76).

Conclusions: This study shows that late improvements in awareness are not exceptional in non-traumatic prolonged disorders of consciousness cases. It highlights the importance of long-term follow up of patients with prolonged disorders of consciousness, regardless of the etiology, age, and time passed since the brain injury. Long-term follow up will help clinicians to identify patients who may benefit from further assessment and rehabilitation. Although only one patient achieved recovery of function, recovery of awareness may have important ethical implications especially where withdrawal of artificial nutrition and hydration is considered.

  • Implications for rehabilitation
  • Long-term regular follow-up of people with prolonged disorders of consciousness is important.

  • Albeit with poor functional outcomes late recovery of awareness is possible in both traumatic and non-traumatic prolonged disorders of consciousness cases.

  • Recovery of awareness has significant clinical and ethical implications especially where withdrawal of artificial nutrition and hydration is considered.

  相似文献   
62.

Purpose

We report here a unique case of a sudden loss of vision as the first symptom of an advanced chronic nephropathy.

Methods and Results

A 25-year-old man was referred to the Department of Ophthalmology with sudden visual deterioration presumptively diagnosed as bilateral retinitis. The patient had never been under any medical care before and had never had any clinical signs of any chronic disease. He underwent an ophthalmic examination with optical coherence tomography (OCT). Based on the clinical features, OCT scans and systemic blood pressure (BP) assessment (225/145 mm Hg), the patient was definitely diagnosed with hypertensive retinopathy and choroidopathy due to hypertensive crisis. After urgent diagnostic procedures, the patient was diagnosed with a chronic kidney disease at stage 5 in the course of chronic glomerulonephritis. Immediately, a renal replacement therapy was started and the patient was qualified for renal transplantation.

Conclusion

Adolescents with an unclear picture of retinal lesions, who have neither a history nor clinical signs of a systemic disease, should undergo careful systemic screening with BP assessment. A sudden deterioration of vision may be the first symptom of a previously undiagnosed severe systemic disease (very rare chronic) that requires immediate treatment.Key Words: Hypertensive crisis, Hypertensive choroidopathy, Hypertensive retinopathy, Chronic renal failure  相似文献   
63.

Purpose

To describe total fluid intake (TFI) according to socio-demographic characteristics in children and adolescents worldwide.

Methods

Data of 3611 children (4–9 years) and 8109 adolescents (10–18 years) were retrieved from 13 cross-sectional surveys (47 % males). In three countries, school classes were randomly recruited with stratified cluster sampling design. In the other countries, participants were randomly recruited based on a quota method. TFI (drinking water and beverages of all kinds) was obtained with a fluid-specific record over 7 consecutive days. Adequacy was assessed by comparing TFI to 80 % of adequate intake (AI) for total water intake set by European Food Safety Authority. Data on height, weight and socio-economic level were collected in most countries.

Results

The mean (SD) TFI ranged from [1.32 (0.68)] to [1.35 (0.71)] L/day. Non-adherence to AIs for fluids ranged from 10 % (Uruguay) to >90 % (Belgium). Females were more likely to meet the AIs for fluids than males (4–9 years: 28 %, OR 0.72, p = 0.002; 10–18 years: 20 %, OR 0.80, p = 0.001), while adolescents were less likely to meet the AI than children (OR 1.645, p < 0.001 in males and OR 1.625, p < 0.001 in females).

Conclusions

A high proportion of children and adolescents are at risk of an inadequate fluid intake. This risk is especially high in males and adolescents when compared with females or children categories. This highlights water intake among young populations as an issue of global concern.
  相似文献   
64.
Weight loss from exercise-induced energy deficits is usually less than expected. The objective of this systematic review was to investigate predictors of energy compensation, which is defined as body energy changes (fat mass and fat-free mass) over the total amount of exercise energy expenditure. A search was conducted in multiple databases without date limits. Of 4745 studies found, 61 were included in this systematic review with a total of 928 subjects. The overall mean energy compensation was 18% ± 93%. The analyses indicated that 48% of the variance of energy compensation is explained by the interaction between initial fat mass, age and duration of exercise interventions. Sex, frequency, intensity and dose of exercise energy expenditure were not significant predictors of energy compensation. The fitted model suggested that for a shorter study duration, lower energy compensation was observed in younger individuals with higher initial fat mass (FM). In contrast, higher energy compensation was noted for younger individuals with lower initial FM. From 25 weeks onward, energy compensation was no longer different for these predictors. For studies of longer duration (about 80 weeks), the energy compensation approached 84%. Lower energy compensation occurs with short-term exercise, and a much higher level of energy compensation accompanies long-term exercise interventions.  相似文献   
65.
Heart Failure Reviews - Few millions of new cancer cases are diagnosed worldwide every year. Due to significant progress in understanding cancer biology and developing new therapies, the mortality...  相似文献   
66.
67.
Right classification of diabetes is important clinical issue. The aim of present study was to compare clinical, biochemical and immunological features, to analyze their practical use and to establish new decision tree which make the distinction between diabetes type 1, LADA, diabetes type 2 and MODY. We studied 97 not obese (mean BMI 26.3 +/- 4.9 kg/m2) patients aged 14 to 70 years, mean age 43 +/- 11.7 years, 53 women, 44 men. Mean duration of diabetes--2.3 +/- 4.3 years. We measured basal and stimulated C-peptide (6 minutes after 1 mg i.v. glucagon) (ELISA) and antibodies titers to glutamic acid decarboxylase--antiGAD65, tyrosine phosphatase-like molecule--IA2 and insulin--IAA (RIA). Autoimmune diabetes (LADA, type 1) was diagnosed with presence of one or more islet antigen antibodies. The highest frequencies had anti-GAD antibodies 33/97 (34%). The most complicated was to sort out group of patients with LADA. Comparison between this group and patients with diabetes type 2 have shown that BMI, co-existence of autoimmune disease, autoimmune markers and basal and stimulated C-peptide level measured at entry for the classification were useful in differentiation. Moreover we observed significantly lower C-peptide basal, stimulated and over basal level in group with MODY diabetes in comparison to diabetes type 2 patients. In the studied group were 5 patients with diabetes type 2 and obesity, in relatively young age. At the end there was one case of ADM (atypical diabetes mellitus). Clinical criteria for the classification of diabetes not always correlated with diagnosis. Autoimmune markers, basal and stimulated C-peptide were useful specially in differentiation between LADA and diabetes type 2 or diabetes type 1. Autoimmune diabetes co-existe with autoimmune disease. Proposed diagnostic scheme take for consideration presence of autoantibodies as well as C-peptide criteria.  相似文献   
68.
Intercellular adhesion molecule-1 (ICAM-1) is 1 of the possible factors linking obesity and diabetes with cardiovascular disease, however, the mechanism of the increase in ICAM-1 concentration in obesity remains unclear. Therefore, the aim of the present study was to assess plasma soluble ICAM-1 (sICAM-1) levels in obese subjects with normal glucose tolerance and to evaluate whether those levels may be related to insulin resistance and tumor necrosis factor-alpha (TNFalpha) system activity. The study was performed in 8 lean and 15 obese subjects. Anthropometric and biochemical parameters were measured, and insulin sensitivity was evaluated using the euglycemic hyperinsulinemic clamp technique (insulin infusion, 50 mU x kg(-1) x h(-1)). Obese subjects were markedly more hyperinsulinemic and insulin resistant and had higher plasma soluble TNF receptor 2 (sTNFR2) and sICAM-1 levels. sICAM-1 was related positively to body mass index (BMI), waist-to-hip ratio (WHR), percent of body fat, glycated hemoglobin (HbA(1c)), plasma insulin and triglycerides (TG), TNFalpha, and sTNFR2 and negatively to insulin sensitivity. Multiple regression analysis showed that only sTNFR2 and insulin sensitivity were independent predictors of sICAM-1 concentrations and were responsible for 66% of sICAM-1 variability. We conclude that an increase in plasma sICAM-1 concentration in obesity is related to TNFalpha system activation and insulin resistance.  相似文献   
69.
Dermatomyositis (DM) is a connective tissue disease characterized by specific inflammatory lesions in muscle biopsy. It is caused by vasculitis determined by humoral factors with subsequent inflammatory cell accumulation, mainly T CD4+ and B cells, which infiltrate myocytes leading to its vacuolization and degeneration (mainly in the skeletal muscles, rarely in the smooth muscles). The incidence of DM is estimated at 1-10 per million in adults and at 1-3.2 per million in children. The autoimmune mechanism of disease induction is not fully recognized. Several lines of evidence showed the link between DM and neoplastic disease. The first report of dermatomyositis associated with stomach cancer, by Stertz, comes from 1916. In the same time, Kankeleit reported DM associated with breast cancer. Presumably, it is the result of immune reaction against antigens common for muscle and neoplastic cells or some paraneoplastic syndrome underlying mechanism. The report presents the case of a 52-year-old woman with DM (diagnosed according to the Bohan and Peter criteria) and with coexistent squamous lung cancer in situ. The left upper lobectomy was performed. No complications in postoperative period were observed. During more than 2 years of follow-up after the surgery, the patient remained in good condition, without DM symptoms, or cancer relapse. Considering that DM may be associated with lung cancer; extensive diagnostic work-up to exclude neoplastic lesions should be performed. Patients aged 40 years or more should be particularly screened.  相似文献   
70.
The objective of the paper was compare the effects and tolerability of combined therapy of multiple intravenous infusions of anti-tumour necrosis factor-alfa (TNF-alfa) monoclonal antibody (Remicade) with methotrexate versus treatment with sodium aurothiomalate and intramuscular depot methylprednisolone in rheumatoid arthritis (RA). We investigate also the interval necessary to obtain the improvement in both treatment groups. 36 patients commencing intramuscular sodium aurothiomalate therapy with intramuscular depot methylprednisolone acetate at weeks 0, 4, 8 and 12 in addition to chrysotherapy were compared in retrospective analysis with 32 patients starting with multiple intravenous infusions of infliximab, anti-TNF-alfa monoclonal antibody (Remicade) and methotrexate at a stable dose. Patients were assessed by composite clinical score (DAS 28) and C-reactive protein during 22 weeks of therapy. At week 2 and 6 a significantly greater percentage of infliximab-treated than gold-treated RA patients achieved improvement in each clinical measurement of disease activity. At 22 week of treatment moderate and good response according to EULAR criteria was achieved in 91% of infliximab-treated patients and 58% gold treated patients (p < 0.001). Adverse events were more frequently observed in infliximab-treated patients, but only gold-treated patients discontinued treatment because adverse events (2 patients due to proteinuria, 2 patients due to mucocutaneous changes and one patient due to leucopenia). The higher percentage of adverse events in infliximab-treated patients was caused mainly by the occurrence of infusion reactions (23 reactions out of 160 infusions); most of them were mild (somnolentia and headache) and transient. Viral infections (including herpes simplex and zoster) were more common in patients treated with infliximab and methotrexate. Combination therapy of infliximab and methotrexate is more effective in reducing clinical and biochemical disease activity than gold with methylprednisolone treatment in RA patients during 22 weeks of treatment, especially in the first 6 weeks.  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