黄芩苷对温敏凝胶的模板作用及其形态和性能功能

以黄酮类化合物黄芩苷作为功能单体,在二甲基甲酰胺溶液中制备得到不同黄芩苷含量的聚异丙基丙烯酰胺水凝胶。通过红外、紫外、扫描电镜和热分析等方法研究了所得凝胶的结构、形态、温敏性和力学性能。结果表明：黄芩苷的加入导致聚合凝胶由无色变为黄色,所得凝胶孔壁出现褶皱,孔洞尺寸随黄芩苷含量的增加而增加。黄芩苷在凝胶基体中主要起到模板作用,它的引入并未改变纯凝胶的体积相转变温度(VPTT）,VPTT仍保持在32~34 °C,但温度敏感性能得到了明显改善,同时改善了纯凝胶的溶胀度和温度脉冲响应性,提高了储能模量。     

快速成型胸椎个体化导航模板精确度实验研究

目的：观察快速成型胸椎个体化导航模板的精确度,为快速成型个体化导航模板的临床使用提供参考。方法：选取12个完整的胸椎干燥骨标本,根据其CT扫描资料,利用计算机辅助设计及快速成型技术设计制作出相应的胸椎模型及个体化导航模板,通过个体化导航模板在胸椎标本及其模型上应用直径2．0mm的钻头模拟椎弓根螺钉置钉手术,直视观察钻头在椎弓根及椎体内的位置及走行方向。用精确度为0．02mm的游标卡尺对快速成型胸椎模型的精确性进行测量。结果：个体化导航模板和相应的胸椎标本及其模型后部解剖结构之间轮廓一致,贴附吻合良好,置入椎弓根进钉通道的钻头均完全位于椎弓根及椎体内,其走行方向和椎弓根的走行方向一致;所有胸椎模型和相应胸椎标本的解剖形态完全一致,胸椎标本和模型之间的误差范围在（0．49±0．28）mm之间。结论：虽然快速成型模型与实物之间有一定的误差,但其误差不影响对椎弓根准确定位及定向的精度要求。     

模板DNA质量对单核苷酸多态性分析的影响

目的探索在单核苷酸多态性分析中模板DNA质量对实验的影响以及提高模板DNA质量的途径。方法用PCR—RFLP法研究SNPrs1024611（G／A）的基因分型,从样本保存方式、保存时间及DNA提取方法三方面进行对比实验,观察其对模板DNA质量及SNP分析的影响。结果从抗凝血中提取DNA模板的得率比非抗凝血高,在SNP分析中,EDTA抗凝血效果最好、肝素抗凝血效果不好;基因组DNA在全血中的有效保存时间比提纯的DNA有效时间长;试剂盒法提取DNA的得率和纯度均高于传统的酚-氯仿法。结论可通过以下途径提高SNP研究中DNA模板的质量：采集血样用EDTA抗凝、分装成小份在-20℃冻存,避免反复冻融。使用前在37℃水浴中快速解冻,用试剂盒法提取DNA更适合于SNP的研究,提取的模板DNA要及时实验或分装后冻存于-20℃,若需长期保存模板DNA,保存全血优于保存纯化的DNA。     

真皮组织微观化重建的探索性研究

目的 从微观角度探讨真皮基质三维结构对Fb生物学行为的影响.方法 借鉴平面几何、三角函数分析真皮组织三维结构,按照真皮组织由黏附成分和非黏附成分组成的原理,通过计算机辅助设计不同参数具有细胞黏着作用的点状结构阵列;运用微图案印刷和分子自组装法,建立4种(8μm×3 μm、间距6 μm,16 μm×3μm、间距6 μm,16 μm×5μm、间距8 μm,20 μm×3 μm、间距2 μm)具有细胞黏附点的桥墩样结构阵列细胞培养基质(MPGCC)培养人Fb,以无MPGCC培养的Fb为对照.利用免疫组织化学、荧光免疫组织化学、噻唑蓝法、羟脯氨酸含量测定法,检测培养Fb中骨架蛋白α-平滑肌肌动蛋白(α-SMA)表达、细胞活力和细胞分泌情况.结果 数学推导结果提示,真皮组织三维结构可用MPGCC进行模拟.用上述4种规格MPGCC培养的Fb其α-SMA表达百分率依次为(49±3)%、(61±3)%、(47±4)%、(51±3)%,与对照组(12±3)%比较,差异有统计学意义(P<0.05);Fb活力依次为0.12±0.03、0.13±0.04、0.14±0.03、0.19±0.03,与对照组0.35±0.04比较显著下降(P<0.05);羟脯氨酸含量依次为(0.95±0.04)、(0.87±0.03)、(0.81±0.03)、(0.77±0.03)μg/mg,与对照组(0.53±0.03)μg/mg比较显著上升(P<0.05).通过调整桥墩角度和桥墩间阵列参数,4组阵列相互对比,α-SMA表达、细胞活力和羟脯氨酸含量差异均有统计学意义(P<0.05).结论 MPGCC可能是真皮模板的基本功能单位或称为真皮模板单元,不同的真皮组织三维环境可产生不同的模板效应和创面愈合结局.     

黏着斑微操控在创伤和组织修复中的作用

目的 探讨真皮模板单元-黏着斑微操控制对皮肤成纤维细胞生物学行为影响. 方法 采用微图案方法制作微凸阵列,运用分子自组装在微凸上自组装结构蛋白分子,在自制细胞培养仪模拟皮肤生物力学进行细胞牵拉2周,并行形态学观察和细胞免疫组织化学分析. 结果 细胞牵拉2周后,细胞形态多样、丰满,分泌增加,呈现顺应性.细胞免疫组织化学分析发现,整合素β1、α5表达较对照显著减少,张力蛋白tensin表达显著降低. 结论 通过黏着斑微操控,增生性瘢痕成纤维细胞在形态学及生物学行为上发生改变.     

Synthesis of Conducting Polymer Spiral Nanostructures Using a Surfactant Crystallite Template

The present work describes, for the first time, the synthesis of spiral nanostructures of conducting polymers by chemical oxidant polymerization using a hydrated surfactant (sodium dodecyl sulfonate (SDSn)) crystallite template. A spiral dislocation structure on the surface of a hydrated SDSn crystallite has been observed and is responsible for the growth of the spiral nanoarchitecture of conducting polymers (polypyrrole, polyaniline). Ammonium peroxydisulfate (APS) has a strong tendency to induce the formation of a spiral dislocation structure of hydrated SDSn crystallites. The mechanism of adsorption of pyrrole or aniline oligomers on the steps of dislocation is proposed for the growth of conducting polymer spirals.

     

Interactive computer-aided diagnosis of breast masses: computerized selection of visually similar image sets from a reference library

RATIONALE AND OBJECTIVES: The clinical utility of interactive computer-aided diagnosis (ICAD) systems depends on clinical relevance and visual similarity between the queried breast lesions and the ICAD-selected reference regions. The objective of this study is to develop and test a new ICAD scheme that aims improve visual similarity of ICAD-selected reference regions. MATERIALS AND METHODS: A large and diverse reference library involving 3,000 regions of interests was established. For each queried breast mass lesion by the observer, the ICAD scheme segments the lesion, classifies its boundary spiculation level, and computes 14 image features representing the segmented lesion and its surrounding tissue background. A conditioned k-nearest neighbor algorithm is applied to select a set of the 25 most "similar" lesions from the reference library. After computing the mutual information between the queried lesion and each of these initially selected 25 lesions, the scheme displays the six reference lesions with the highest mutual information scores. To evaluate the automated selection process of the six "visually similar" lesions to the queried lesion, we conducted a two-alternative forced-choice observer preference study using 85 queried mass lesions. Two sets of reference lesions selected by one new automated ICAD scheme and the other previously reported scheme using a subjective rating method were randomly displayed on the left and right side of the queried lesion. Nine observers were asked to decide for each of the 85 queried lesions which one of the two reference sets was "more visually similar" to the queried lesion. RESULTS: In classification of mass boundary spiculation levels, the overall agreement rate between the automated scheme and an observer is 58.8% (Kappa = 0.31). In observer preference study, the nine observers preferred on average the reference lesion sets selected by the automated scheme as being more visually similar than the set selected by the subjective rating approach in 53.2% of the queried lesions. The results were not significantly different for the two methods (P = .128). CONCLUSIONS: This study suggests that using the new automated ICAD scheme, the interobserver variability related issues can thus be avoided. Furthermore, the new scheme maintains the similar performance level as the previous scheme using the subjective rating method that can select reference sets that are significantly more visually similar (P < .05) than when using traditional ICAD schemes in which the mass boundary spiculation levels are not accurately detected and quantified.     

经桡动脉入径应用EBU系列指引导管完成右冠状动脉复杂病变的初步经验

目的 探讨应用EBU系列指引导管行右冠状动脉复杂病变介入治疗（ PCI） 的可行性。 方法 前瞻性分析2020年1月至2021年12月首都医科大学附属北京友谊医院及平谷区医院心内科应用EBU指引导管介入治疗右冠状动脉复杂病变25例患者的临床资料、 影像资料和术后恢复情况,对该技术的可行性和安全性进行评价。 结果 25例患者经冠状动脉造影确诊为冠心病,且均存在右冠状动脉复杂病变,有对右冠状动脉行PCI的指征。所有患者均经桡动脉入路使用EBU指引导管行PCI。25例患者的EBU指引导管全部输送到位,经调整进入右冠状动脉开口,EBU导管使用的成功率为100%。25例患者全部行右冠状动脉PCI,24例成功,PCI成功率为96%,无患者出现指引导管相关并发症。结论 经桡动脉应用EBU指引导管行右冠PCI具有很好的可行性和安全性,可作为部分经选择患者行右冠复杂病变PCI的首选方法。     

Fusion of nearby inverted repeats by a replication-based mechanism leads to formation of dicentric and acentric chromosomes that cause genome instability in budding yeast

Large-scale changes (gross chromosomal rearrangements [GCRs]) are common in genomes, and are often associated with pathological disorders. We report here that a specific pair of nearby inverted repeats in budding yeast fuse to form a dicentric chromosome intermediate, which then rearranges to form a translocation and other GCRs. We next show that fusion of nearby inverted repeats is general; we found that many nearby inverted repeats that are present in the yeast genome also fuse, as does a pair of synthetically constructed inverted repeats. Fusion occurs between inverted repeats that are separated by several kilobases of DNA and share >20 base pairs of homology. Finally, we show that fusion of inverted repeats, surprisingly, does not require genes involved in double-strand break (DSB) repair or genes involved in other repeat recombination events. We therefore propose that fusion may occur by a DSB-independent, DNA replication-based mechanism (which we term “faulty template switching”). Fusion of nearby inverted repeats to form dicentrics may be a major cause of instability in yeast and in other organisms.     

个性化喙锁韧带重建导向器的设计及精度评价

目的　设计个性化喙锁韧带重建导向器,并评价其钻孔精度和效率。 方法　使用计算机辅助设计软件设计个性化喙锁韧带重建导向器,并进行3D打印。获取90侧肩关节标本,随机平均分为3组,分别在微创双切口下使用徒手法和C臂导向器、个性化导向器引导法进行锁骨-喙突钻孔。测量手术时间、喙突骨隧道分区和喙突骨隧道至喙突内、外侧缘距离。 结果　徒手组、C臂导向器组、个性化导向器组的手术时间分别为(203±33)、(267±62)、(155±14) s。3组分别有13、28、30个喙突骨隧道位于理想中间区。使用3种方法建立的喙突骨隧道与喙突内、外侧缘距离差分别为(3.7±2.0)、(2.0±0.9)、(0.9±0.5) mm。差异均有统计学意义(P<0.05)。 结论　个性化导向器具有更高的钻孔精度和效率,为微创下辅助锁骨-喙突钻孔提供了新的选择。