Correlation Study of Aortic Velocity Propagation, Abdominal Aortic Intima-Media Thickness, and Epicardial Adipose Tissue Thickness in Subclinical Hypothyroidism Patients

Objective:To explore the correlation between epicardial fat thickness(EFT),aortic velocity propagation(AVP),and abdominal aortic intima-media thickness(AA-IMT)in patients with subclinical hypothyroidism(SH).Additionally,to compare these indicators between SH patients and healthy individuals,providing a new theoretical basis for the clinical prevention and treatment of cardiovascular diseases.Method:Clinical data from 50 SH patients(23 males and 27 females)and 50 healthy outpatient examinees(22 males and 28 females)were analyzed.The participants were selected from January 2022 to December 2023 at Loudi Central Hospital.EFT,AVP,and AA-IMT were measured,and their correlations were analyzed.Results:SH patients had significantly higher EFT and AA-IMT levels than the control group,while their AVP was significantly lower,with these differences being statistically significant(P<0.05).Correlation analysis revealed a significant negative correlation between EFT and AVP(P<0.001),a significant positive correlation between EFT and AAO-IMT(P<0.001),and a significant negative correlation between AVP and AAO-IMT(P<0.001).Multivariate binary logistic regression analysis identified increased EFT,decreased AVP,and increased AAO-IMT as independent risk factors for SH patients.Conclusion:In SH patients,EFT and AAO-IMT are elevated,whereas AVP is reduced.EFT and AVP are significantly correlated with AAO-IMT.EFT and AAO-IMT can serve as reliable indicators for evaluating subclinical atherosclerosis in SH patients,providing a diagnostic basis for clinical practice.

Quality control of ultrasonic measurement of carotid artery intima-media thickness

Background To report quality control methods and baseline reproducibility data of the ultrasound measurements of carotid artery intima-media thickness in the project of Establishment of an Integrated System for Coronary Heart Disease Prevention and Treatment. Methods Standard ultrasound scanning and measuring protocols were established by the study group. All sonographers and readers were trained by the carotid ultrasound core lab and all digital ultrasound images were centrally read. Ten subjects were scanned twice （with 1 week interval） by 2 sonographers independently and images were read by a single reader to evaluate the sonographer variability. Twenty subjects＇ images were read twice （with 1 week interval） by a single reader to assess the reader variability and the reproducibility of IMT measured at different carotid segments. Results The intraclass correlation （ICC） of intra- and inter-sonographer and intra- reader for mean IMT measurements was 0.99, 0.98 and 0.97 respectively; while for max IMT, it was 0.97, 0.99 and 0.95 respectively. Among different carotid segments and sites, ICC for mean 1MT measurements of common carotid （CCA）, carotid artery bulb （Bulb）, internal carotid artery （ICA）, overall near wall and overall far wall was 0.97, 0.99, 0.89, 0.93 and 0.98 respectively. Conclusion The reproducibility of IMT measurements according to our protocol is acceptable, although better reproducibility is found when measuring the mean IMT than max IMT, CCA and Bulb IMT than ICA IMT, and far wall IMT than near wall IMT.

Correlation between Waist Circumference and Carotid Intima-Media Thickness in Women from Shanghai, China

Objective To evaluate whether waist circumference （WC） 〉85 cm is related to asymptomatic preclinical atherosclerosis in women from Shanghai, China. Methods A total of 2365 females aged 〉20 years recruited from 4 communities underwent physical examination and carotid artery scanning. Their carotid intima-media thickness （C-iMT） was measured. Results The C-IMT was significantly higher in overweight or obese women with their BMI 〉25.0 kg/m2 {P〈O.01） and in those with their WC _〉85 cm than in those with their WC 〈85 cm （P〈O.01）. Spearman and partial correlation analysis showed that the C-IMT was significantly correlated with WC which was independent of menopausal status. The C-IMT significantly increased with the increasing WC and reached to a platform in about 85 cm. An increment tendency was found in the subgroup with its WC 〈 85 cm （P〈O.01） while no significant tendency was found in the subgroup with its WC_〉85 cm （P=0.07）. Multiple stepwise regression analysis showed that the WC was an independent risk factor for C-IMT. In logistic regression model, the odd ratio of WC _〉80 cm, _〉80 cm and 〈85 cm and 〉85 cm for evaluating the risk of C-IMT elevation was 2.632, 2.501, and 1.878, respectively. Conclusion WC is significantly correlated with C-IMT in women from Shanghai, China, and WC_〉85 cm may be used in identifying the risk of subclinical carotid atherosclerosis.

Ultrasound Assessraent of Intima-media Thickness and Diameter of Carotid Arteries in Patients Undergoing Hemodialysis or Renal Transplantation

Renal transplant （RT） recipients have a high risk of developing cardiovascular diseases. However, the effects of renal transplantation on the development of arteriosclerosis have been controversial. The carotid intima-media thickness （CIMT） and diameter （CD） are important indicators of vascular remodeling and arteriosclerosis. In this study, 31 patients with hemodialysis （HD）, 31 RT recipients and 84 age- and gender-matched control subjects were enrolled. Their CIMT and CD were measured by ultrasonic radiofrequency tracking, and the linear regression models and Z test were used to identify the progression of arteriosclerosis and the risk factors. Compared with HD group, RT group had significantly lower CIMT and CD. CIMT was found to be associated with age, body weight, resistance index and diastolic velocity, while CD was associated significantly with age, body weight, pulsatility index, end diastolic velocity and diastolic blood pressure （DBP）, respectively. The correlation curves between CIMT and age showed the slopes of curves were decreased successively in control, RT and HD groups, and the curves between CD and age showed the slopes were decreased in order of RT 〉 control 〉 HD groups. It was concluded that CIMT and CD were significantly correlated with age in RT and moderately with age in HD patients. RT could reduce the progress of arteriosclerosis in patients with end-stage renal disease.

Relationship between Carotid Intima-Media Thickness and Diabetes Clinical Risk Factors among Normotensive Type 2 Diabetes Mellitus among Native Black African Population

Background: Type 2 diabetes mellitus is frequently associated with atherosclerosis with changes in the thickness of the intima-media of carotid arteries which causes increased risk of cardiovascular diseases. Cardiovascular disease is a major cause of morbidity and mortality in this group of patients. The carotid artery reflects the degree of atherosclerosis in the various vessels especially coronary arteries. Measurement of the carotid artery thickness with real time, relatively cheap and non-invasive ultrasonography method is used in monitoring atherosclerotic disease progression and response to treatment. This study is aimed at ultrasonographic evaluation of the carotid intima-media thickness (CIMT) in adult Type 2 Diabetic patients compared to non-diabetic healthy controls matched for age, gender and body mass index (BMI). And to also determine its association if any with selected clinical factors among a native Black African population. Methodology: This was a prospective case control study involving 54 adult type 2 diabetics and 54 adult non-diabetic controls. CIMT was measured at 3 segments of the extracranial carotid arteries by a 7.5 - 10 MHz linear transducer of a portable Mindray M5 ultrasound machine. Results: Among the native black African population studied, there was significant difference in CIMT of adult type 2 diabetics compared to healthy non-diabetics adults (p value = 0.012 and 0.001 on the right and left respectively). The mean carotid intima-media thickness in diabetics was 0.81 mm and 0.85 mm, while in non-diabetics it was 0.74 mm and 0.75 mm on the right and left respectively. The presence of diabetes showed independent positive correlation with CIMT (beta: 0.24, p value = 0.004). Age (beta: 0.30, p value = 0.001) and plasma cholesterol level (beta: 0.30, p value = 0.013) also had positive correlation with CIMT. Conclusion: There was statistically significant difference in carotid intima-media thickness between adult type 2 diabetics and age, sex matched non-diabetics. DM showed independent correlation with CIMT.

Coronary atherosclerosis burden is not advanced in patients with β-thalassemia despite premature extracardiac atherosclerosis： a coronary artery calcium score and carotid intima-media thickness study

Background Thalassemic patients demonstrate an increased rate of extracardiae vascular complications and increased carotid wall intima-media thickness （cIMT）, but very low prevalence of coronary artery disease （CAD）. We investigated the atheroma burden by assessing the coronary artery calcium （CAC） and elMT in these patients. Methods We examined 37 patients with β-thalassemia and 150 healthy control volunteers with multi-detector computer tomography （CT） and ultrasonography to determine CAC score and cIMT, respectively. Results Propensity score matching （C-statistic： 0.88; 95% CI： 0.83-0.93） resulted in 27 pairs of patients; severe CAC was observed in 2 （7.4%） and 0 of β-thalassemia patients and healthy volunteers respectively （P = 0.5）. Median calcium score was 0 （0-0） in β-thalassemia patients and 0 （0-4） in healthy volunteers （P = 0.8）. Median intima-media thickness was higher in β-thalassemia patients compared to control group [0.45 （0.06-0.65） vs. 0.062 （0.054-0.086）; P = 0.04]. Conclusions Patients with β-thalassemia in comparison with healthy control subjects exhibit similar CAC score and increased cIMT. Our findings indicate a disparate rate of progression of atherosclerosis between coronary and extracardiac arteries in these patients lending support to the epidemiological evidence.

A REVIEW ON ARTERY WALL SEGMENTATION TECHNIQUES AND INTIMA-MEDIA THICKNESS MEASUREMENT FOR CAROTID ULTRASOUND IMAGES

Stroke and heart attack,which could be led by a kind of cerebrovascular and cardiovascular disease named as atherosclerosis,would seriously cause human morbidity and mortality.It is important for the early stage diagnosis and monitoring medical intervention of the atherosclerosis.Carotid stenosis is a classical atherosclerotic lesion with vessel wall narrowing down and accumulating plaques burden.The carotid artery of intima-media thickness(IMT)is a key indicator to the disease.With the development of computer assisted diagnosis technology,the imaging techniques,segmentation algorithms,measurement methods,and evaluation tools have made considerable progress.Ultrasound imaging,being real-time,economic,reliable,and safe,now seems to become a standard in vascular assessment methodology especially for the measurement of IMT.This review firstly attempts to discuss the clinical relevance of measurements in clinical practice at first,and then followed by the challenges that one has to face when approaching the segmentation of ultrasound images.Secondly,the commonly used methods for the IMT segmentation and measurement are presented.Thirdly,discussion and evaluation of different segmentation techniques are performed.An overview of summary and future perspectives is given finally.

Determining factors for carotid mean/max intima-media thickness and brachial flow-mediated dilation in healthy young women

Background: Many factors can contribute to atherosclerotic-type vascular changes in older individuals or men. Thus, confining the investigation to young women with no clinical evidence of the condition could enhance understanding of the early stages of cardiovascular disease. The aim of this study was to determine whether carotid mean/max intima-media thickness (IMT) and brachial flow-mediated dilation (FMD) values, which are well-known event-related indices, are associated with laboratory data and the other vascular indices of atherosclerosis in healthy young women. Methods: Carotid mean/max IMT and brachial FMD were measured in young women with no clinical evidence of atherosclerosis (n = 110;mean age, 39 years) who were instructed not to eat, drink or smoke after 9 PM the evening before testing. All participants also underwent laboratory assessment, including simultaneous measurements of arterial stiffness such as augmentation index (AI), cardioankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV). Results: Mean IMT was signifi-cantly and positively associated with age (p = 0.002), CAVI (p = 0.044), low-density lipoprotein-cholesterol (LDL-C, p = 0.047) and high-sensitive C-reactive protein (hs-CRP, p = 0.002) values but was not related to FMD, AI, baPWV or triglycerides (TG) in the multivariate regression analysis. Similarly, max IMT was positively associated with age (p p = 0.003) and hs-CRP (p = 0.005) values but was not related to FMD, AI, CAVI, baPWV, TG or blood pressure level in the multivariate regression analysis. The association between LDL-C and max IMT was much stronger than that between LDL-C and mean IMT. Brachial FMD was positively associated only with heart rate in the multivariate regression analysis. Conclusions: These results suggest that mean IMT more closely represents the sclerotic aspect of vascular change, whereas max IMT represents the atherotic aspect in healthy young women. Although the relationship between the autonomic nervous system and heart rate is well-known, there may be a complex interaction between the autonomic nervous system and endothelial function.

Relationship between peripheral arterial disease, carotid intima-media thickness and C-reactive protein in elderly diabetic patients

Purpose: To study the association between carotid intima media thickness (CIMT) and high sensitivity CRP (hs-CRP) level as markers for PAD in elderly patients with DM. Subjects: A case-control study on 90 participants aged 60 years and older divided into 60 cases (30 patients with DM alone and 30 patients with DM and comorbidities) and 30 healthy controls. All were assessed by measuring CIMT, ankle brachial index (AB), and markers for cardiovascular disease such as high-sensitivity CRP (hs-CRP), total cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL), and low density lipoprotein (LDL). Results: hs-CRP levels showed statistically significant difference being highest among patients with DM and comorbidities and lowest among controls (P < 0.001). Also, symptoms of PAD were significantly higher among cases than controls. ABI was able to detect PAD in many asymptomatic patients. Color changes were present in only 43.30% (n = 26) of positive PAD cases while delayed wound healing, claudication pain, rest pain, cold extremities, and trophic changes were present in 23.30% (n = 14), 16.71% (n = 10), 16.71% (n = 10), 45.00% (n = 27), and 21.7% (n = 13). Using logistic regression analysis revealed that DM, CIMT, and hs-CRP were independent predictors for PAD (OR = 4.194, 7.236, 1.003;P value = 0.044, 0.25, 0.031) after adjustment of other coronary risk factors such as sex, smoking, hypertension, TC, and TG. Conclusion: Diabetic elderly have higher prevalence of asymptomatic PAD thannon-diabetics using solely ABI. DM, CIMT, and hs-CRP are independent predictors for the occurrence of PAD. Hs-CRP levels are highest among diabetics with comorbidities.

Relationship of plasma homocysteine, soluble intercellular adhesion molecule-1, high mobility group box 1 protein with carotid intima-media thickness in elderly patients with type 2 diabetes mellitus

Objective:To explore the relationship of plasma homocysteine(Hcy),soluble intercellular adhesion molecule-1(sICAM-1)and high mobility group box 1 protein(HMGB1)with carotid intima-media thickness(c-IMT)in elderly patients with type 2 diabetes mellitus.Methods:A total of 100 elderly patients who were diagnosed as type 2 diabetes mellitus in Baogang Hospital of Inner Mongolia from June 2017 to May 2020 were chosen as research objects.According to c-IMT,they were divided into the normal group(n=35),the mild to moderate group(n=41)and the severe group(n=24).The expression levels of plasma Hcy,sICAM-1 and HMGB1 were compared between groups respectively.Pearson’s correlation coefficient was used to analyze the relationship of plasma Hcy,sICAM-1,HMGB1 with c-IMT.Results:The comparison in plasma Hcy,sICAM-1,HMGB1 and c-IMT among the three groups of patients was of statistical significance(p<.05).The results of correlation analysis showed that the expression levels of plasma Hcy,sICAM-1 and HMGB1 were positively correlated with c-IMT in elderly patients with type 2 diabetes mellitus(r=.627,.598,.614;p<.05).Conclusions:The expression levels of plasma Hcy,sICAM-1 and HMGB1 are abnormally increased in elderly patients with type 2 diabetes mellitus,and related to c-IMT,which can provide a strong evidence for clinical diagnosis and treatment by detecting their levels in clinical practice.

Measurement of Cortical Bone Thickness in Adults by Cone-beam Computerized Tomography for Orthodontic Miniscrews Placement

The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic adults with normal occlusion were taken to measure the cortical bone thick- ness in both.jaws. One-way analysis of variance （ANOVA） was used to analyze the differences in cortical bone thickness. Buccal cortical bone in the mandible was thicker than that in the maxilla. In the maxilla, cortical bone thickness was thicker in the buccal side than in the palatal side. Buccal cortical bone thickness in the mandible was thickest at the site distal to the first molar, and in the maxilla it was thickest at the site mesial to the first molar, while in the palatal side of maxilla it was thickest at the site mesial to the second premolar. The changing pattern of cortical bone thickness varies at different sites. In the buccal side of maxilla, the thinnest cortical bone thickness was lbund to be at 4 mm level from the alveolar crest, while the thickest was at 10 mm level （except for the site mesial to the first premolar）. The buccal cortical bone thickness at the sites mesial or distal to the first molar in the mandible and palatal cortical bone thickness of maxilla tended to increase with increasing distance from the alveolar bone.

QTL Mapping for Hull Thickness and Related Traits in Hybrid Rice Xieyou 9308

We conducted a quantitative trait locus （QTL） analysis of 165 rice recombinant inbred lines derived from a cross between Zhonghui 9308 （Z9308） and Xieqingzao B （XB） in Hainan and Hangzhou, China. Grain thickness （GT）, brown rice thickness （BRT）, hull thickness （HT） and milling quality were used for QTL mapping. HT was significantly and positively correlated with GT and BRT. Twenty-nine QTLs were detected with phenotypic effects ranging from 2.80% to 21.27%. Six QTLs, qGT3, qBRT3, qBRT4, qHT6.1, qHT8 and qHT11, were detected repeatedly across two environments. Inherited from XB qHT6.1, qHT8 and qHT11 showed stable expression, explaining 9.92%, 21.27% and 10.83% of the phenotypic variances in Hainan and 9.61%, 6.40% and 6.71% in Hangzhou, respectively. Additionally, the QTL cluster between RM5944 and RM5626 on chromosome 3 was probably responsible for GT and milling quality. The cluster between RM6992 and RM6473 on chromosome 4 played an important role in grain filling. Three near isogenic lines （NILs）, X345, X338 and X389, were selected because they contained homozygous fragments from Zhonghui 9308, corresponding to qHT6.1, qHT8 and qHT11, respectively. The hull of XB was thicker than those of X345, X338 and X389. In all the lines, qHT6.1, qHT8 and qHT11 that regulated rice HT were stably inherited with obvious genetic effects.

VARIATIONS IN CRUSTAL THICKNESS OF THE KANE TRANSFORM IN THE NORTH ATLANTIC OCEAN

A new approach was taken to investigate the crustal stucture of the Kane transform and its aseismic extension, using high quality bathymetry and gravity data. The gravity signatures associated with variations in crustal thickness of the transform were isolated from the observed free air anomaly, was continued downward to the mean depth of the crust/mantle interface and converted onto the relief on that surface. The crustal thickness of the transform was then calculated by subtracting seawater depth from the depth of the gravity inferred crust/mantle interface.3 D gravity investigation results indicate that the Kane transform and adjacent areas are associated with a crust thinner than normal oceanic crust. The transform trough is largely underlain by a crust less than 4.5km thick and in the nodal basins the crust may be as thin as 3 km. The crust beneath the fracture zone valley is 4-5.5 km thick. The rift valleys on the spreading segments are also characterized by thin crust (4-5 km thick). Thin oceanic crust extends to 20-30 km from the transform axis,except for some localized places such as the inside corner highs adjoining the ridge transform intersections. These gravity inferred results match fairly well with limited published seismic results. Thinning of the crust is mainly attributable to a thin layer 3, which in turn may be explained by the combined effects of reduced magma supply at the ends of the spreading segments and tectonic activities in the region.

植物生长调节剂对金奉猕猴桃果实品质与果皮厚度的影响

【目的】中华猕猴桃金奉果皮极薄,在生产中极易因碰伤、擦伤而导致果实受损,非常不利于贮藏和长距离运输。通过植物生长调节剂和矿质元素处理,以期筛选出适宜金奉猕猴桃果皮增厚和提高果实品质的有效处理措施。【方法】使用不同种类和不同质量浓度的植物生长调节剂和矿质元素的处理组合,对金奉猕猴桃幼果进行浸果或叶面喷施处理,检测处理后的金奉猕猴桃果实品质、果实解剖结构和果皮细胞壁代谢相关酶活性的变化情况。【结果】不同处理均显著增加了果实的纵径和单果质量,且对果实内在品质有不同程度的改善效果。100 mg·L^(-1)GA_(3)+5 g·L^(-1)CaCl_(2)处理组合的果实品质最佳,但对果皮厚度改善的效果并不明显。不同质量浓度的6-BA和NAA处理均显著增加了外果皮厚度。其中,25 mg·L^(-1)NAA叶面喷施处理、25 mg·L^(-1)和50 mg·L^(-1)6-BA浸果处理对金奉猕猴桃外果皮增厚的效果最为显著。【结论】综合各处理对金奉猕猴桃果实品质和果皮厚度的影响,以及操作技术的简单易行,确定25 mg·L^(-1)NAA叶面喷施为最佳的处理。

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections.Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase data.As a result,little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19.To address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this study.Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis.We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes.The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores.Additionally,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls.The 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances.Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection.These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Impact of nitrogen doping on growth and hydrogen impurity incorporation of thick nanocrystalline diamond films

A much larger amount of bonded hydrogen was found in thick nanocrystalline diamond （NCD） films produced by only adding 0.24% N2 into 4% CH4/H2 plasma, as compared to the high quality transparent microcrystalline diamond （MCD） films, grown using the same growth parameters except for nitrogen. These experimental results clearly evidence that defect formation and impurity incorporation （for example, N and H） impeding diamond grain growth is the main formation mechanism of NCD upon nitrogen doping and strongly support the model proposed in the literature that nitrogen competes with CHx （x = 1, 2, 3） growth species for adsorption sites.

Donor cornea quality used for penetrating keratoplasty vs deep anterior lamellar keratoplasty

Deep anterior lamellar keratoplasty(DALK) has recently been introduced as an alternative procedure to penetrating keratoplasty(PK) for corneal pathologies not affecting the corneal endothelium. DALK does not rely on donor endothelium and requires less rigid criteria for donor corneal tissue quality. Therefore, DALK makes it possible to use donor corneas deemed unsuitable for PK. Furthermore, lamellar keratoplasty allows acellular corneal tissue to be transplanted. As a result, long-term preservation techniques are being revisited to increase the availability of donor corneas and subsequently alleviate constraints of availability, cost, storage, and transportation in many countries. The recent alterations in corneal transplantation techniques and hence the type of donor cornea tissues used for each technique, may require corneal surgeons and eye banks to reevaluate their selection criteria. The purpose of this systematic review is to present an updated analysis on the type and quality of donor corneas used for PK and DALK, assess the influence of donor and eye bank factors on the quality of donor corneas, and determine whether any of these donor factors affect clinical outcomes, complications, and graft survivals.

压缩感知不同加速因子对心脏磁共振电影序列成像质量的影响

目的 探讨不同加速因子的压缩感知(CS)技术对心脏磁共振电影序列图像质量的影响及临床应用的可行性。资料与方法 前瞻性招募合肥市第一人民医院2021年1—7月40名健康志愿者进行心脏磁共振成像,扫描方案共4组(采用SENSE 2及加速因子分别为3、4、8的CS心脏电影序列),每组成像方案包括四腔心、左心室短轴、左心室两腔心及三腔心序列,对比4种方案的图像质量主观评分、左心室心功能及16节段心肌厚度。结果 以SENSE 2图像为标准评分(5分),CS3、CS4评分均在3分以上,CS8评分均在3分及以下,其中CS3与SENSE 2序列的四腔心及左心室短轴图像质量主观评分差异无统计学意义(P均>0.05);左心室两腔心及三腔心各序列组图像质量主观评分差异均有统计学意义(P均<0.05)。4种成像方案的左心室心功能(左心室射血分数、左心室收缩末期容积、左心室舒张末期容积、左心室每搏输出量、左心室舒张末期心肌质量)(F=0.027、0.182、0.057、0.140、0.545)与心肌厚度(F=0.052~7.366)各组间差异均无统计学意义(P均>0.05)。结论 基于CS技术的心脏电影序列具有良好的应用前景。随着加速因子的增加,扫描时间逐渐减少,相应的图像质量降低,而当加速因子为4(与常规电影序列相比扫描时间减少50%)时,仍能够准确进行左心室心功能及心肌厚度测量,且图像质量基本满足诊断需求。

Effect of short term intensive multitherapy on carotid intima-media thickness in patients with newly diagnosed type 2 diabetes mellitus

Background Controlling plasma glucose levels, blood pressure and lipid levels is proven to reduce the risk of vascular complications in patients with type 2 diabetes mellitus. This has prompted intensive multitherapy targeted at several macrovascular risk factors. Carotid intima-media thickness （cIMT） is a reliable measure of early atherosclerosis. We sought to determine whether a 6-month intensive mutiltherapy program resulted in better goal attainment than usual care and its effect on the development of cIMT among patients with newly diagnosed type 2 diabetes mellitus. Methods The study randomly assigned 220 patients with newly diagnosed type 2 diabetes mellitus to intensive or traditional therapy groups. The clinical parameters, such as fasting plasma glucose, total cholesterol, triglyceride, blood pressure, body weight and insulin were assessed at the baseline and after the 6-month therapy, cIMT of the patients was also obtained. Results The average levels of fasting plasma glucose, hemoglobin Alc, total cholesterol （TC） and low-density lipoprotein cholesterol （LDL-C） in the intensive group were significantly lower than those in the control group at the end of 6-month treatment. By 6 months, a higher proportion of patients in the intensive therapy group than in the control group attained goals for fasting plasma glucose （FPG）, TC, LDL-C and hemoglobin Alc. With intensive multherapy the level of carotid intima-media thickness in the intensive therapy group was lower than that in the control group （（0.88±0.26） mm vs （0.96±0.22） mm, P 〈0.01）. Conclusions The evidence from this clinical trial demonstrates that intensive glucose, lipid and blood pressure control in patients with newly diagnosed type 2 diabetes is associated with diabetic macrovascular benefits. Intensive multitherapy allows more patients to achieve aims of control and may reduce macrovascular complications and delay disease progression.

重载列车荷载作用下路基夹层现象的分析

重载列车荷载作用下路基夹层、道砟囊、翻浆冒泥等路基病害频发,严重影响了列车的安全运行。为分析重载列车荷载作用下路基夹层现象,采用自制试样筒对路基土(粉质黏土)和道砟进行循环加载试验,分析重载列车荷载作用下试样变形特性及路基夹层的产生与发展过程;进而提出路基夹层的两个主要表征指标,即路基夹层厚度和细颗粒迁移质量。结果表明:1)重载列车荷载作用下,试样的轴向变形呈非线性增大的趋势;路基夹层在加载初期较为明显,加载后期路基夹层的变化不明显。2)采用路基夹层厚度及细颗粒迁移质量这两个指标对路基夹层特性进行表征,路基夹层厚度、细颗粒迁移质量与路基土体初始干密度近似呈线性负相关关系,与循环荷载幅值近似呈线性正相关关系,而加载频率对路基夹层厚度和细颗粒迁移质量的影响相对较小。