Ordering Behavior of Layered Silicate Nanocomposites with a Cylindrical Triblock Copolymer

Summary: The ordering behavior of the nanocomposites of organically modified montmorillonite (OMMT) with a cylindrical triblock copolymer of polystyrene‐block‐poly(ethylene‐co‐butylene)‐block‐polystyrene (SEBS) has been investigated by temperature‐resolved small‐angle X‐ray scattering (SAXS) and rheometry. X‐Ray diffraction (XRD) confirms that the polymer chains are successfully intercalated with the interlayer gallery of the silicates. The data obtained from the SAXS and rheological measurements show that the addition of OMMT leads to a change in the microphase separation behavior of SEBS in the nanocomposites. The molecular interaction between OMMT and the polystyrene (PS) chains of SEBS decreases the structural perfection of the self‐assembling, phase‐separated domain structure of the nanocomposites. Rheological data exhibit that the order‐order (T_OOT) and order‐disorder transitions (T_ODT) of the SEBS/OMMT nanocomposites decrease with the addition of OMMT. The highest elongation at break is obtained at approximately 2% OMMT and its further addition to the mixture leads to decreases in tensile strength and elongation.

The change in the storage modulus (G′) of a) SEBS, b) S98M2, c) S95M5, and d) S90M10, as a function of temperature in the range of 150 ≤ T (°C) ≤ 260.     

One‐Step Approach for the Preparation of Organic‐Inorganic Janus‐Like Particles by Alkalization of Polystyrene‐block‐Poly(2‐vinylpyridine)/FeCl3 Complex Micelles

A novel approach to organic‐inorganic Janus‐like particles based on the alkalization process of polystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) micelles containing FeCl₃ precursors in the P2VP cores in toluene is presented. It is found that by addition of a small amount of NaOH solution to a solution of the spherical PS‐b‐P2VP/FeCl₃ micelles, organic‐inorganic Janus‐like particles with a produced α‐FeOOH domain on one side and PS‐b‐P2VP block copolymers on the other can be prepared. The Janus‐like nanoparticles obtained by this facile approach may have potential application in biomedical areas.     

胸腰椎爆裂性骨折形态学异常的放射学测量及其与脊髓损伤的关系

目的：探讨胸腰椎爆裂性骨折形态学异常与脊髓损伤的关系。方法：回顾性分析７８例胸腰裂性骨的,根据椎管正中矢状状径计算椎管狭窄率,并按Ｃｏｂｂ法测量后凸畸形角度,同时记录ＡＳＩＡ下肢运动评分结果：无脊髓损伤、不完全脊髓损伤及完全脊髓损伤三组的椎管狭窄率及后凸畸形角度相差无显著统计撑意义（Ｐ〉０．０５）,椎管狭窄率及后凸畸形角度与ＡＳＩＡ评分相关笥无显著统计学意义（ＰＭ〉０．０５）。结论：胸腰椎爆裂性骨     

全凭静脉麻醉和硬-腰联合阻滞麻醉对直肠温度的影响

目的观察全凭静脉麻醉与硬-腰联合阻滞不同麻醉方式对患者围术期直肠温度的影响。方法顺序选择ASAI或Ⅱ级全凭静脉麻醉下行择期腹腔镜胆囊切除术患者50例(全凭静脉麻醉组)与硬-腰联合阻滞麻醉下行胫腓骨手术患者50例(硬-腰联合阻滞组),连续观察两组围术期直肠温度及生命征变化。结果两组直肠温度麻醉后逐步下降,术毕值与术前值比较差异有显著性(P<0.05),全麻组下降幅度(1.60±0.16)℃明显大于硬-腰联合阻滞麻醉组(1.04±0.01)℃(P<0.05);生命征组间比较无显著性差异(P>0.05)。结论全凭静脉麻醉与硬-腰联合阻滞麻醉均可降低患者围术期直肠温度,前者较后者明显。     

CBCT辅助诊断上颌第一磨牙双腭根伴副根管1例

报道第一磨牙罕见双腭根,同时存在髓室底副根管及牙颈部釉质凸起病例1例.该病例的诊疗过程提示借助锥束CT(CBCT)及显微镜等技术可以避免发生遗漏根管,改善根管治疗效果.     

The benefit of bilateral inferior alveolar nerve block in managing postoperative nausea and vomiting (PONV) after mandibular osteotomy

IntroductionThe purpose of our study was to evaluate the benefit of bilateral inferior alveolar nerve block (BIANB) in managing postoperative pain, nausea and vomiting and opioid and antiemetic consumption in mandibular osteotomy.Material and methods51 patients operated for bilateral sagittal split osteotomy (BSSO) were included in this prospective randomized controlled, double-blind, superiority trial.In the first group (n = 25), standard protocol was applied (general anesthesia and postoperative multimodal analgesia). The second group (n = 26) received bilateral inferior alveolar nerve block anesthesia at the start of surgery in addition to routine protocol. Postoperative monitoring was conducted every 4 h over the first 24 h and targeted the following criteria: postoperative nausea and vomiting (PONV), the visual analog scale (VAS) for pain, consumption of morphine (cumulative dose) and antiemetic agents, need for removal of guiding elastics.ResultsPONV was significantly lower in the BIANB group (15.4 % VS 40 %, p = 0.049), as were mean VAS scores for pain (1 VS 1.57, p = 0.045) and medians of morphine bolus (8 [6–16] VS 5.5 [1–8], p = 0.033). We found no significant difference in incidence of guiding elastic removal, and antiemetic consumption.DiscussionThe use of BIANB in BSSO improved postoperative patient comfort in terms of PONV and pain. Furthermore, it led to a decrease in opioid consumption. In conclusion, it is an additional therapeutic means of improving patients' postoperative comfort.     

三种因素对根管桩道预备后根尖封闭性影响的研究

目的:评价根管形态、根管充填方法、根管封闭剂三种因素对桩道预备后根管的根尖封闭性的影响.方法:本实验共选取45颗规则的直根管牙根及40颗椭圆形根管牙根,分为9组.其中实验组A组为规则的直根管,A1.iRoot SP+热牙胶(n=10),A2.iRoot SP+单尖法(n=10),A3:GuttaFlow2+热牙胶(n=...     

牙周源性牙周牙髓联合病变常见病原菌的分布及其意义

目的研究牙周源性牙周牙髓联合病变常见病原菌分布及其相关性,为临床治疗提供依据。方法选择2018年1月至2020年6月于新疆维吾尔自治区人民医院口腔科就诊的牙周源性牙周牙髓联合病变患者43例43颗牙作为实验组,重度牙周炎患者41例41颗牙作为对照组。分别采集根管内组织和龈下菌斑,构建含有8种待测细菌基因片段的重组质粒,建立定量标准,应用实时荧光定量PCR技术检测福赛斯坦纳菌(Tannerella forsythia,Tf)、牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)、具核梭杆菌(Fusobacterium nu?cleatum,Fn)、中间普氏菌(Prevotella intermedia,Pi)、齿垢密螺旋体(Treponema denticola,Td)、消化性链球菌(Digestive streptococcus,Ds)、粪肠球菌(Enterococcus faecalis,Ef)、牙髓卟啉单胞菌(Porphyromanus endodontics,Pe)数量。结果实验组根管内组织与其龈下菌斑中Ds、Pe数量差异无统计学意义(Ρ>0.05),其余6种病原菌数量差异均有统计学意义(P<0.05);实验组与对照组龈下菌斑中Ds数量差异无统计学意义(P=0.241),其余7种病原菌数量差异均有统计学意义(P<0.05);实验组根管内组织与其龈下菌斑中Ef、Pe、Pg、Td、Tf细菌数量密切相关,Ef(r=0.347,Ρ<0.05)、Pe(r=0.363,Ρ<0.05)、Pg(r=0.437,Ρ<0.01)、Td(r=0.471,Ρ<0.01)、Tf(r=0.679,Ρ<0.01)。结论牙周源性牙周牙髓联合病变常见病原菌在根管内组织中数量低于龈下菌斑但根管内病原菌数量与龈下菌斑密切相关,临床治疗期间在控制牙周组织感染的同时,还应重视牙髓组织感染的控制。     

3种不同镍钛器械对弯曲根管成形能力的研究

目的：比较TF、K3XF和K3三种镍钛器械在树脂模拟根管中的成形能力。方法：45个单弯树脂模拟根管随机分为3组,分别采用TF,K3XF和K3进行根管预备。记录预备前后的形态,使用图像处理、分析软件测量并比较3组间根管弯曲度的变化和偏移的情况。结果：TF组和K3XF组的根管弯曲偏移值较小,在统计学上无显著性差异;而K3组偏移值较大与TF组和K3XF组在统计学上有显著性差异（P〈o．05）。结论：在预备树脂弯曲根管中,TF和K3XF较K3能更好地维持根管原有的形态。     

上颌第二乳磨牙近中颊根第二根管的临床研究

探讨上颌第二乳磨牙近颊第二根管（MB2）的特征及临床治疗方法。选取患牙髓炎或根尖周炎的上颌第二乳磨牙95颗,拍摄术前及根充后 X 线片,采用耳鼻喉内窥镜观察测量髓室底各根管口位置关系;术中采用10号锉结合17％EDTA 凝胶探查根管,手动器械进行根管预备,螺旋输送器导入 Vitapex 糊剂充填根管。在95颗上颌第二乳磨牙中,有14颗存在 MB2,发现率为14．7％,MB2位于 MB-P 根管口之间假想连线的近中。