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   426篇
  免费   43篇
耳鼻咽喉   12篇
儿科学   13篇
妇产科学   9篇
基础医学   38篇
口腔科学   13篇
临床医学   25篇
内科学   97篇
皮肤病学   32篇
神经病学   33篇
特种医学   37篇
外科学   50篇
综合类   7篇
预防医学   16篇
眼科学   11篇
药学   56篇
中国医学   1篇
肿瘤学   19篇
  2023年   2篇
  2022年   7篇
  2021年   18篇
  2020年   10篇
  2019年   12篇
  2018年   26篇
  2017年   14篇
  2016年   19篇
  2015年   24篇
  2014年   38篇
  2013年   32篇
  2012年   37篇
  2011年   47篇
  2010年   21篇
  2009年   8篇
  2008年   22篇
  2007年   13篇
  2006年   11篇
  2005年   20篇
  2004年   6篇
  2003年   7篇
  2002年   6篇
  2001年   5篇
  2000年   7篇
  1999年   10篇
  1998年   3篇
  1997年   2篇
  1995年   2篇
  1994年   2篇
  1991年   5篇
  1990年   9篇
  1989年   4篇
  1988年   2篇
  1987年   6篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1941年   1篇
排序方式: 共有469条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.

Aim of the work

To compare the D-dimer status in children with familial Mediterranean fever (FMF) during, and in between acute attacks.

Patients and methods

The study included 50 children with FMF classified into group I (15 patients during acute attack) and group II (35 patients during attack free period) as well as and 20 matched controls. D-dimer was determined in all study population. Pattern and type of FMF gene mutation were reported from patients’ files.

Results

The mean age of the patients was 8.7 ± 2.8 years, disease duration 4.4 ± 2.5 years and they were 28 males:22 females (1.3:1). In group I, the erythrocyte sedimentation rate (48.5 ± 28.6 mm/1st h) and aspartate transaminase (28.5 ± 5 U/L) were significantly increased compared to group II (26.6 ± 14.7 mm/1st h and 25.7 ± 2.7 U/L; p = 0.012 and p = 0.014 respectively). Positive D-dimer was significantly reported in 72% of FMF patients compared with 35% of control (p = 0.006). There was significant difference between frequency of positive D-dimer in group I (86.7%) and group II (65.7%) compared to (35%) in control (p = 0.005 and p = 0.048, respectively), without a significant difference in D-dimer frequency between group I and group II patients (p = 0.18). Fever and abdominal pain were significantly more frequent in patients with positive (100% and 97.2%) compared to negative D-dimer (78.6% and 71.4%) (p = 0.02). No significant association was found between positive D-dimer and specific types of MEFV gene mutation.

Conclusion

D-dimer was significantly positive in FMF patients compared to control. These results raise the possibility of thrombosis in FMF patients regardless the presence or absence of acute attack.  相似文献   
105.

Background

Hepatorenal syndrome (HRS) occurs in decompensated liver disease and carries high mortality. Vasoconstrictors are the drug of choice. Terlipressin is widely used and is expensive. In this study, we compared noradrenaline and terlipressin in the management of type 1 HRS.

Methods

Sixty consecutive patients with type 1 HRS were managed with noradrenaline (Group A, n?=?30) or terlipressin (Group B, n?=?30) with albumin in a randomized controlled trial at a tertiary center.

Results

Reversal of type 1 HRS was achieved in 16 (53%) patients in group A and 17 (57%) in group B. There was statistically insignificant difference between the two groups in decreasing serum creatinine and increasing urine output (p?>?0.05). On univariate analysis, Child-Turcotte-Pugh (CTP) score, serum sodium, serum urea, serum albumin, prothrombin time, International normalized ratio (INR), serum alanine aminotransferase (ALT), ascitic fluid protein, and history of bleeding were associated with response to treatment (noradrenaline/terlipressin). However, on multivariate analysis, only baseline CTP score, serum urea, serum albumin, and prothrombin time were independent predictors of response. All patients who responded were discharged alive with no mortality within 30 days.

Conclusions

There is no difference in outcome of patients with type 1 HRS treated with noradrenaline or terlipressin. Thus, noradrenaline, which is cheaper, can be used instead of terlipressin (Clinical Trials Registry-India [CTRI] No. CTRI/2011/09/002032).
  相似文献   
106.
107.
Correction for ‘Utilizing FBR to produce olefins from CO reduction using Fe–Mn nanoparticles on reduced graphene oxide catalysts and comparing the performance with SBR’ by AL-Hassan Nasser et al., RSC Adv., 2018, 8, 42415–42423.

The authors regret that the original author list was incorrect. The correct author list is as shown above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.  相似文献   
108.

Background

To evaluate and quantify the impact of a novel image-based motion correction technique in myocardial T2 mapping in terms of measurement reproducibility and spatial variability.

Methods

Twelve healthy adult subjects were imaged using breath-hold (BH), free breathing (FB), and free breathing with respiratory navigator gating (FB + NAV) myocardial T2 mapping sequences. Fifty patients referred for clinical CMR were imaged using the FB + NAV sequence. All sequences used a T2 prepared (T2prep) steady-state free precession acquisition. In-plane myocardial motion was corrected using an adaptive registration of varying contrast-weighted images for improved tissue characterization (ARCTIC). DICE similarity coefficient (DSC) and myocardial boundary errors (MBE) were measured to quantify the motion estimation accuracy in healthy subjects. T2 mapping reproducibility and spatial variability were evaluated in healthy subjects using 5 repetitions of the FB + NAV sequence with either 4 or 20 T2prep echo times (TE). Subjective T2 map quality was assessed in patients by an experienced reader using a 4-point scale (1-non diagnostic, 4-excellent).

Results

ARCTIC led to increased DSC in BH data (0.85 ± 0.08 vs. 0.90 ± 0.02, p = 0.007), FB data (0.78 ± 0.13 vs. 0.90 ± 0.21, p < 0.001), and FB + NAV data (0.86 ± 0.05 vs. 0.90 ± 0.02, p = 0.002), and reduced MBE in BH data (0.90 ± 0.40 vs. 0.64 ± 0.19 mm, p = 0.005), FB data (1.21 ± 0.65 vs. 0.63 ± 0.10 mm, p < 0.001), and FB + NAV data (0.81 ± 0.21 vs. 0.63 ± 0.08 mm, p < 0.001). Improved reproducibility (4TE: 5.3 ± 2.5 ms vs. 4.0 ± 1.5 ms, p = 0.016; 20TE: 3.9 ± 2.3 ms vs. 2.2 ± 0.5 ms, p = 0.002), reduced spatial variability (4TE: 12.8 ± 3.5 ms vs. 10.3 ± 2.5 ms, p < 0.001; 20TE: 9.7 ± 3.5 ms vs. 7.5 ± 1.4 ms) and improved subjective score of T2 map quality (3.43 ± 0.79 vs. 3.69 ± 0.55, p < 0.001) were obtained using ARCTIC.

Conclusions

The ARCTIC technique substantially reduces spatial mis-alignment among T2-weighted images and improves the reproducibility and spatial variability of in-vivo T2 mapping.  相似文献   
109.
We recently identified a cohort of children with recurrent episodes of acute otitis media (AOM) who fail to generate protective antibody titres to otopathogens and several vaccine antigens. In this study we determined the antibody levels against DTaP vaccine antigens, diphtheria toxoid (DT), tetanus toxoid (TT) and acellular pertussis toxoid (PT) in sera from 15 stringently defined otitis-prone (sOP) children and 20 non-otitis-prone (NOP) children. We found significantly lower concentrations of immunoglobulin (Ig)G antibodies against vaccine antigens in the serum of sOP children compared to age-matched NOP children. To elucidate immunological cellular responses to the vaccines in these children, we investigated memory B cell responses to DTaP vaccination. We used fluorescently conjugated vaccine antigens to label antigen receptors on the surface of memory B cells and examined the frequency of antigen-specific CD19+ CD27+ memory B cells in the peripheral blood. sOP children showed a significantly lower percentage of antigen-specific CD19+ CD27+ memory B cells than NOP children. We also found a linear correlation between the frequencies of memory B cells and circulating IgG titres for DT, TT and PT proteins. To our knowledge, this is the first study to show significant differences in memory B cell responses to DTaP vaccine antigens and their correlation with the circulating antibodies in young children with recurrent AOM.  相似文献   
110.

Background

The effect of elevated heart rate (HR) on outcomes after heart transplantation (HT) has not been well established. The aim of this study was to assess predictors of elevated HR following HT and its impact on outcomes.

Methods and Results

We retrospectively evaluated 394 patients who underwent HT at 2 academic medical centers from 2005 to 2016. Patients were divided into 2 groups based on HR 1 year after HT: HR ≥95 beats/min (n?=?162; 41%) and HR <95 beats/min (n?=?232; 59%). Median follow-up time was 6.6 (interquartile range [IQR] 2.2–7.5) years. HR ≥95 beats/min 1 year after HT was associated with younger donor age, whereas HR <95 beats/min was associated with heavy donor alcohol use and African-American recipient race. Left ventricular (LV) end-diastolic dimension, mass, and ejection fraction were lower and E/E′ higher in the HR ≥95 group at the time of the last follow up. HR ≥95 beats/min at 1 year after HT was independently associated with the development of cardiac allograft vasculopathy and increased mortality.

Conclusions

HR ≥95 beats/min 1 year after HT is associated with a reduction in LV size and function, increased incidence of cardiac allograft vasculopathy, and reduced survival. Studies investigating the effect of medical HR reduction on post-HT outcomes are warranted.  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