脊髓型颈椎病患者三维有限元模型的构建与生物力学分析

目的：构建颈部三维有限元模型(finite element model,FEM),初步分析脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者与对照者颈部生物力学的差异,为CSM发病机制的研究提供生物力学依据。方法：以1名CSM患者作为力学模拟实验对象进行三维CT扫描,并构建颈部三维FEM依照患者的年龄、性别、身高、体重等参数选取本团队已有的健康颈部三维FEM作为对照,比较患者和对照者在颈椎正常受力情况下椎体、椎间盘、韧带及脊髓的应力差异,以及后仰伸运动后最大应力的差异。结果：成功构建CSM患者及对照者FEM模型,并进行力学分析,CSM患者颈椎椎体受力差异C5~C6节段最明显,对照者和患者的最大应力部位均在椎体前缘,CSM患者椎体前缘的最大应力小于对照者;CSM患者椎间盘应力分布不均匀,最大应力部位集中在椎间盘底部后缘的两侧;CSM患者各韧带的应力分布不均匀,其中后纵韧带应力最大。CSM患者颈椎在后仰伸运动时范围受限。结论：CSM患者相对于对照者可能存在颈部椎体、椎间盘及韧带受力平衡的改变和颈椎运动范围的受限,这可能与CSM力学发病机制相关。     

胃镜、B超、CT在进展期胃癌的应用价值

目的探讨胃镜、B超、CT在进展期胃癌诊断、治疗中的应用价值。方法回顾性分析112例经手术及病理证实的进展期胃癌的胃镜、B超、CT资料。结果112例进展期胃癌,胃镜符合率为100%(112/112),B超符合率96.4%(108/112),CT符合率98.2%(110/112);恶性肿瘤TNM分期:B超符合率78.6%(88/112),CT符合率83.0%(93/112)。结论胃镜检查结合黏膜活检仍然是进展期胃癌首选检查手段,B超、CT检查可对胃癌进行术前TNM分期,三者合理应用能更好地提高进展期胃癌的诊断、指导临床治疗、术后疗效观察及预后判断水平。     

16层螺旋CT在心房颤动射频消融术前的应用测量

目的研究心房颤动导管射频消融肺静脉电隔离术前左心房、肺静脉和食管16层螺旋CT成像技术及临床意义。资料与方法40例心房颤动患者在术前1-3天行多层螺旋CT（MSCT）检查,采用容积再现（VR）、多平面重组（MPR）及最大密度投影（MIP）等方法重组并测量各肺静脉口直径、左心房至肺静脉第一分支的距离、食管与左心房后壁接触的范围、食管壁厚度、左心房后壁厚度以及左心房与食管间的脂肪垫厚度。结果共显示肺静脉165支,右上肺静脉口前后径和上下径分别为（16.3±3.1）mm和（19.0±2.6）mm;右下肺静脉分别为（16.4±3.6）mm和（18.0±3.5）mm;左上肺静脉分别为（14.4±3.0）mm和（18.4±3.6）mm;左下肺静脉分别为（12.6±2.8）mm和（17.0±2.8）mm。食管与左心房后壁接触的平均长度为（56±12）mm,在双上、下肺静脉水平与左心房后壁接触的食管平均宽度分别为（10±5）mm和（14±5）mm。60%的食管位于左心房后壁中线偏左,大致与左上、下肺静脉口平行;40%的食管沿左上肺静脉向右下肺静脉斜行走行。左心房后壁和食管前壁的平均厚度分别为（2.2±0.8）mm和（3.5±1.6）mm。95%的左心房与食管间可见脂肪垫,其平均厚度为（0.8±0.2）mm。结论应用MSCT造影增强扫描可清楚显示各肺静脉口直径、分支特征、走行以及有无发育畸形,同时还能评价食管与左心房的关系,为心房颤动导管射频消融术的顺利实施提供重要解剖依据。     

Influence of Silica Fume on High-Calcium Fly Ash Expansion during Hydration

The purpose of this work was to study the possibility of neutralizing high-calcium fly ash expansion during hydration. The object of the study was the fly ash of Berezovskaya GRES, which is capable of independent setting and hardening. The test in the Le Chatelier molds showed that the divergence of indicator arms was 90–100 mm 1 day after mixing with water. The expansion and cracking of the fly ash could be completely prevented by silica fume addition in an amount of 42.9% by weight of the fly ash. At the same time, the compressive strength of specimens from the fly ash–sand paste in a ratio of 1:5 at the age of 28 days was 1.47 MPa. The isothermal heat release at a temperature of 20 °C for 10 days reached 500 kJ/kg. XRF and DTA results showed that free lime in the fly ash was completely hydrated in 11 days and gave the greatest expansion in the absence of silica fume. The presence of silica fume made the lime hydration incomplete and decreased the expansion. Unslaked free lime remained in the system. Exothermic data showed that silica fume inhibited CaO hydration from the reaction start.     

螺旋CT对气管支气管异物和狭窄的诊断价值

目的：探讨螺旋CT（MSCT）对气管、支气管异物和狭窄的诊断价值。方法：对18例可疑支气管异物的患儿进行MSCT检查。将获得的轴位扫描图像行Minp及MPR重建,并与支气管镜检查结果对照。结果：MSCT显示异物15例,21枚,其中1例异物CT值为278HU,其余14例CT值为-10．6～31．0HU;位于主支气管6例,叶支气管9例,其中并发段支气管异物4例。支气管炎性狭窄2例,异物取出后气道狭窄1例。异物及气管狭窄的显示以MPR和Minp图像最好。支气管镜所见与MSCT一致,但4例并发段支气管异物者未发现。MSCT所见不仅与支气管镜吻合,而且可准确显示段支气管以下的异物。结论：MSCT可准确显示气管、支气管异物与狭窄的直接和间接征象,并较准确地判定异物性质,对小儿支气管异物的诊断有重要参考价值。     

儿童甲型H1N1流感病毒肺炎的胸部影像学特征

<正>2009年3月墨西哥暴发甲型HIN1流感疫情,随后出现了全球大流行。此次疫情的病原为变异后的新型甲型H1N1流感病毒,人类普遍易感[1-2]。甲型H1N1流感是一种急性呼吸系统传染病,多数病例临床表现温和,少数病例病情进展迅速,可出现病毒性肺炎,合并呼吸衰竭、多脏器功能损伤,严重者可导致死亡。据文献报道,甲型H1N1流感病毒性肺炎患者中71%为严重肺炎,发生年龄为5～59岁[3],     

青阳参甙元的分子结构研究

青阳参甙是一种已用于临床,对癫痫病有较好疗效的药物,其二乙酰甙元的立体分子结构用x射线衍射方法进行了测定,并与几种作用于神经系统药物的分子结构作了对比,还讨论了它们共同具有的相似的活性基团。     

增强CT诊断肝细胞癌肾上腺腺瘤与转移瘤的价值分析

目的 探讨增强CT对肝细胞癌肾上腺腺瘤与转移瘤的鉴别价值,以期为临床诊治提供参考依据.方法 回顾性分析2017年10月至2019年11月于我院接受治疗的41例肝细胞癌患者的临床资料,所有入选者均接受增强CT扫描,分析肝细胞癌肾上腺瘤与转移瘤的增强CT影像学特征及三期扫描CT值.结果 ①肾上腺腺瘤:瘤体为较小的圆形或卵圆...     

Rhombohedral Phase Formation in Yttria-Stabilized Zirconia Induced by Dental Technical Tools and Its Impact on Dental Applications

In the study the influence of different dental technical tools on the surface temperature and phase composition of fixed dental prostheses (FDPs) made of yttria-partially stabilized zirconia polycrystals (3Y-/4Y-/5Y-PSZ) was investigated. FDPs were fabricated by using computer-aided manufacturing (CAM). The FDPs were treated with a contra-angle handpiece equipped with different burs and polishers. The resulting surface temperatures were measured with a thermographic camera, and the resulting phase transformations were investigated by X-ray diffraction and quantified by Rietveld refinement. Processing with burs resulted in no phase transformation, but a preferred orientation shift. Using coarse polisher induced a phase transformation to the rhombohedral phase, while fine polishers produced no relevant phase transformations and no preferred orientation shift. Compared to the monoclinic phase (ca. 9% theoretical volume increase), which is associated with low-temperature degradation (LTD), the rhombohedral phase is much more voluminous (ca. 15% theoretical volume increase) and distorted and, therefore, has a greater degradation potential.     

贲门癌的钡餐和CT诊断价值

目的探讨贲门癌的钡餐和CT诊断价值。方法回顾性分析贲门癌的影像学资料,51例钡餐造影,其中39例加作了CT检查。结果贲门癌钡餐造影征象包括贲门部肿块41例,贲门形态的变异和钡流走向改变45例,病变不同程度侵犯食管下端42例,伴胃底黏膜破坏和胃壁僵硬29例,病变侵及胃体部15例。CT征象包括贲门区肿块39例、胃壁增厚6例、食管壁增厚32例、贲门周围淋巴结肿大8例、后腹膜淋巴结肿大5例、肝脏转移灶3例。结论钡餐造影是检出贲门癌的首选方法之一。CT对贲门癌的诊断、术前分期、预后及治疗方案的确定有其重要的价值。