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121.
目的:探讨表观弥散系数(ADC)预测局部晚期鼻咽癌对含多西他赛新辅助化疗敏感性的价值.方法:集2013年3月到2015年7月的鼻咽癌III期及IV期患者34例,分别在新辅助化疗前1周内及2周期新辅助化疗结束后1周进行磁共振扫描,采集不同时间点鼻咽癌原发灶的扩散加权图像(DWI)并分析获得的表观扩散系数(ADC),根据RECIST 1.1指南分别进行疗效分组(化疗高反应和化疗低反应组),采用独立样本t检验比较不同疗效组间不同时间点的ADC值,并应用Spearson等级相关性分析评价ADC值与肿瘤消退率的相关性.结果:新辅助化疗前,化疗高反应组的ADC值治疗前低于化疗低反应组[(1.32±0.25)×10-3mm2/s vs (1.61±0.24)×10-3mm2/s,P=0.001];化疗高反应组的ADC值治疗后为(2.12±0.26)×10-3mm2/s,而化疗低反应组的ADC值治疗后为(1.70±0.45)×10-3mm2/s,差异有统计学意义(P=0.032);化疗高反应组ADC值变化率(△ADC)明显高于化疗低反应组[(63.1±35.6)% vs (14.3±36.9)%,P=0.021];ADC值治疗前与肿瘤消退率负相关(r=-0.451,P=0.007),ADC值治疗后和ADC值变化率(△ADC)与肿瘤消退率正相关(r=0.667,P=0.005;r=0.550,P=0.027).结论:核磁共振表观弥散系数对鼻咽癌新辅助化疗疗效可以进行早期评价,有助于早期进行治疗方案的调整. 相似文献
122.
Yongcheng An Yuhui Duan Hongyu Dai Chen Wang Lu Shi Changhao He Yinglan Lv Huimin Li Shuhang Dai Baosheng Zhao 《中医科学杂志(英文)》2022,9(2):166-180
Objective: To observe the relationship between the different stages of type 2 diabetes mellitus(T2DM)and the intestinal flora and verify its underlying mechanism.Methods: T2DM rats were generated by high-fat diet(HFD) combined with intraperitoneal streptozotocin(STZ) injection. The rats were divided into four groups: the control group(fed with normal feed for1 month), the HFD group(fed with HFD for 1 month), the T2DM group(HFD combined with STZ and blood glucose ≥11.1 m M), and the unformed T2DM... 相似文献
123.
124.
Anton V. Barsukov Alexander E. Korovin Leonid P. Churilov Ekaterina V. Borisova Dmitry V. Tovpeko 《Pathophysiology》2022,29(3):453
Low-intensity systemic inflammation is an important element of heart failure pathogenesis. The aim of this study is to assess proinflammatory status serum indicators (C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6)) in middle-aged males (M) and females (F) with essential hypertension (HTN) depending on left ventricular (LV) diastolic dysfunction (LVDD). The main group comprised 55 M and 49 F with the first- to second-severity grade HTN with mild heart failure and a preserved LV ejection fraction ≥50%. Patients had sinus rhythm, first or second-severity degree LVDD, LV hypertrophy, left atrium dilatation, and NT-proBNP > 125 pg/mL. Comparison group: 30 hypertensives without cardiac dysfunction; control group: 31 normotensives. Quantitative features were compared using the Mann–Whitney test, median χ2, ANOVA module. Spearman’s rank correlation coefficients were determined to identify the relationship between the proinflammatory pattern and exercise tolerance. Hypertensive M had markedly higher CRP, TNF-α, and IL-6 levels compared to F. All mean values corresponded to reference range. In patients with second-degree LVDD, CRP, TNF-α, and IL-6 levels were significantly greater than in subjects with first-degree LVDD (both within M and within F samples). Significant negative associations between CRP, IL-6, and TNF-α levels and the 6 min walk test existed in hypertensive M and F. The study demonstrated a close relationship between the proinflammatory pattern and LVDD and exercise tolerance indicators, regardless of the hypertensive patient’s sex. 相似文献
125.
126.
目的探究工作日与非工作日血糖变异度(glycemic variability, GV)的差异。方法选取2020年1月1日—2020年12月31日在复旦大学附属中山医院厦门医院内分泌科住院且应用血糖管理系统记录住院期间血糖情况的非手术患者,由营养科经系统记录提取所有接受血糖监测的人员名单后加以筛选,入选患者计算工作日与非工作日血糖变异系数(coefficient of variation, CV),并行相关对比。结果共入选232例患者,血糖均值的平均值为(9.58±1.71) mmol/L,血糖标准差的均值为(2.92±0.90) mmol/L,血糖CV的均值为(30.32±6.71)%。工作日血糖CV较非工作日血糖CV大(P<0.001)。按工作日血糖CV是否大于等于非工作日分组,唯一具有统计学差异的是胰岛素应用组(P=0.044)。按工作日与非工作日血糖CV差值绝对值的中位数分组,尿白蛋白肌酐比值(P=0.046)、HbA1c(P=0.001)两组具有存在显著差异。结论住院非手术患者工作日血糖CV比非工作日大,且二者血糖CV相差越大,合并有越多的靶器官损害。 相似文献
127.
The penetration grade system is still widely adopted for selecting asphalt binder with desired paving performance. However, the initial material compositions of asphalt binder with the same penetration level are still different, and vary with the crude oil source and essentially result in different rheological performance. This study aimed to assess the linear viscoelastic (LVE) properties, and high- and intermediate-temperature and microscale characteristics of seven unmodified asphalt binders from different sources and countries with the same penetration level of 70. The LVE parameters were firstly evaluated followed by comparisons to various damage-based indexes. The microstructure of asphalt binders was further investigated followed by correlations between morphology and performance parameters. Experimental results indicate the |G*|/sin δ is well related to the MSCR-based non-recoverable creep compliance; furthermore, the R and |G*|·sin δ can generally represent the LAS-based failure strain and fatigue life, respectively. The viscoelastic nature of tested binders was clearly distinguished and related to rheological performance by atomic force microscopy (AFM). The roughness parameters and the phases’ content derived from AFM images showed significant correlations with LVE characteristics and fatigue resistance nature, respectively. This research provides theoretical foundations for further investigating the rheological performance and microstructure characteristics, and their correlations with asphalt binders. 相似文献
128.
Hydrogen is a main factor in cold cracking or hydrogen-induced cracking. The most crack susceptible region of a steel welded joint is the heat affected zone (HAZ). The formulation and functional-analytical solution of the one-dimensional problem of hydrogen diffusion in an inhomogeneous butt-welded joint considering weld and joint dimensions and initial hydrogen distribution as well as hydrogen diffusion coefficients and solubilities are presented. It is shown that the peak hydrogen concentration in the HAZ of inhomogeneous joints varies in direct proportion to the initial hydrogen concentration in the weld metal. It is inversely proportional to the ratio of hydrogen solubilities in the weld metal and the HAZ metal and is nonlinear in the diffusion coefficient ratio of these metals. The peak hydrogen concentration in the HAZ can exceed 170% of the average initial concentration in the joint if martensitic steel is welded using low-carbon low-alloy welding consumables. The utilization of austenitic consumables leads to a dramatic reduction in the hydrogen concentration in the HAZ in comparison with the non-austenitic consumables. No direct relationship was found between the hydrogen concentration in the HAZ and the hydrogen evolution from the joint surface. 相似文献
129.
To investigate the effect of dimensional changes on the mechanical properties of cemented tailings backfill (CTB), uniaxial compression tests are performed on square CTBs of four different sizes. Combining digital image correlation (DIC) and acoustic emission (AE) methods, the fracture process and AE behavior characteristics of backfills with different sizes are analyzed. The results show that as the backfill size increases, its uniaxial compressive strength decreases, and its strength stabilizes gradually when it measures 100 mm. Under uniaxial compression loading, surface cracks on the smaller specimens evolve rapidly and aggressively, with no significant shedding area, whereas the larger specimens show plastic failure. The cracks expand and penetrate gradually, forming a large shedding area. As the specimen size increases, the backwards trend of the peak value of the ringing count relative to the peak value of the stress becomes increasingly evident. Combining the change law between the r value and the average frequency centroid, the sudden drop point of r value and the lowest value of average frequency centroid can be regarded as the precursor of macroscopic damage. 相似文献
130.
The validity of calculating the dynamic tensile strength of rock materials based on dynamic Brazilian tests is problematic. In order to gain a deeper understanding of the effects of three typical loading methods on the damage mechanism of rock specimens in the dynamic Brazilian tests, five different rocks were selected for the study. In the constant incident energy dynamic Brazilian test, the loading modes had a significant effect on the loading rate and dynamic tensile strength of the specimen, with the highest loading rate and tensile strength of the specimens under mode-III loading, followed by mode-I loading and mode-II loading. A high-speed camera and the digital image correlation (DIC) technique were used to successfully capture the rupture process of the Brazilian disc during impact loading. The evolution of the displacement and strain fields of the specimen was obtained by DIC technique, and four typical failure patterns and two rupture characteristics in the dynamic Brazilian test were summarized. The loading mode determined the crack initiation position of the specimen in the dynamic Brazilian test. The results showed that the mode-III loading is the most consistent with the Brazilian test theory, while the mode-II loading violates the test principle. 相似文献