载美洛昔康壳聚糖膜的制备及预防硬膜外瘢痕粘连的研究

制备负载美洛昔康的壳聚糖控释膜并考查其对硬膜外瘢痕粘连的防治效果.对36只体重200～250 g的雌性健康SD大鼠分别行L2椎板切除术后,随机分为3组:A组,在椎板缺如处不放任何药物:B组,在椎板缺如处涂抹0.5 mL透明质酸钠;C组,在椎板缺如处放置10mm×10 mm载美洛昔康壳聚糖膜.分别在术后3周和6周对术后瘢痕粘连进行评估.大体标本评价结果:术后3周,A组粘连一般,B、C组较轻;术后6周,A、B组粘连较重,C组较轻.组织学评价结果:术后3周,A组硬膜外成纤维细胞较多,B、C组硬膜外成纤维细胞较少;术后6周,A、B组硬膜外纤维细胞多,硬膜囊受压,C组硬膜外成纤维细胞少,粘连轻.结果表明,载美洛昔康壳聚糖膜具有良好的防治硬膜外瘢痕粘连的作用.     

美洛昔康-壳聚糖载药控释膜的力学性能

针对椎板切除术后硬膜外瘢痕粘连治疗中存在的药物作用时间短、全身用药时手术局部药物浓度过低等问题,以非甾体抗炎药关洛昔康为药物模型,以壳聚糖为膜材料,采用流涎蒸发工艺制备预防术后瘢痕粘连的载药控释膜.采用扫描电镜观测药物负载对膜结构的影响,通过测定拉伸强度和断裂伸长率表征膜的力学性能.结果表明,载药膜释放孔道的形成机理为镶嵌-溶解成孔,双层载药膜与单层载药膜相比,表面孔状结构数量减少.载药量为0.3g/g、壳聚糖相对分子质量为31万制备的双层厚膜力学性能较好,其拉伸强度和断裂伸长率分别为1.566 MPa和106.879%,且在pH=7.4的磷酸缓冲溶液中的释放过程中保持了较好的力学稳定性.     

DAM复合型阻尼吸声穿孔板吸声性能的研究

本文对ＤＡＭ复合型阻尼吸声穿 板吸声性能进行了较为系统的研究，讨论了填充吸声材料，Ｂ腔厚度，阻尼穿孔板孔径，穿孔率对吸声性能的影响。     

添加Al_2O_3对SiC板粒／Y－TZP复合材料力学性能的影响

本文以ＳｉＣ板粒、ＺｒＯＣｌ２－８Ｈ２Ｏ、ＡｌＣｌ３和Ｙ（ＭＯ）３为原料，利用共沉淀和热压烧结工艺，制备ＳｉＣ板粒／Ｙ－ＴＺＰ和（含Ａｌ２Ｏ３）ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料．测试了材料的室温和高温力学性能．研究了添加Ａｌ２Ｏ３对ＳｉＣ板粒／Ｙ－ＴＺＯ复合材料的影响．结果表明，ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料与Ｙ－ＴＺＰ陶瓷相比，其室温强度和韧性出现明显下降，高温强度也没有改善；而在ＳｉＣ板粒与Ｙ－ＴＺＰ复合的基础上，添加Ａｌ２Ｏ３可明显提高材料的强度和断裂韧性，同时，材料的高温强度也获得显著改善．     

脊柱椎板切除手术导航系统人机交互设计与实现

研究了脊柱椎板切除手术光电导航系统的应用特点,分析了外科医生的工作内容、流程和方法,建立了医生的认知模型和行为模型,在此基础上,结合椎板切除手术的过程和难点,从安全性和可用性角度提出了人机交互的内容和方法.根据光电导航的特点,在手术空间布局、软件界面布局、三维图像可视化和配准、手术规划及导航操作等方面,设计了椎板切除手术导航系统的人机交互内容.通过临床实验,论证了此方法的导航功能以及人机交互的安全性、高效性和易用性.     

若干功能材料性能优化建模方法研究

通过对稀土荧光粉，ＶＰＴＣ材料，镍氢电池阴极材料的优化建模计算，研究和比较了线性ＰＬＣ方法，加非线性项的ＰＬＣ方法和加非线性项的ＰＬ－ＳＡＮＮ方法建模的效果。结果表明：当材料，性能和影响性能的因子间非线性较为严重时，加非线性项的ＰＬＳ－ＡＮＮ方法建模的效果较好，其预测结果和实测结果相当符合。     

基于A／D板的数字可编程有源滤波模块设计

本文利用Ａ／Ｄ转换板的Ｄ／Ａ输出功能,采用ＭＡＸ０３８、ＭＡＸ２９１芯片,构造了截止频率可编程的低通滤波器模块。     

乙酰乙基纤维素的热致液晶性能及其与PA6原位复合的研究

将乙基纤维素乙酰化制备乙酰乙基纤维素。用ＮＭＲ，ＩＲ测定了ＡＥＣ的乙酰取代度，用ＤＳＣ，ＨＳＰＬＭ研究了ＡＥＣ的热致液晶性能，织构与Ａ－ＤＳ的关系。在此基础上研究了ＰＡ６／ＡＥＣ原位复合单丝的形态结构和力学性能，证明一定条件下ＡＥＣ对ＰＡ６有明显增强作用，总取代度增大是主要作用机制。     

Al2O3短纤维Al—1／5wt%Mg复合材料的界面研究

实验研究了液态浸渗后直接挤压工艺制备的Ａｌ２Ｏ３短纤维／Ａｌ－１．５ｗｔ％Ｍｇ复合材料的界面特点。发现；基体中的Ｍｇ在纤维／基体界面处偏聚，发生了界面反应；反应产物ＭｇＡｌ２Ｏ４，其厚度约为２０ｎｍ，远小于由Ｍｅｔｃａｌｆｅ定义的界面反应层第一临界厚度；界面反应产生ＭｇＡｌ２Ｏ４的存在，为其体与纤维间提供了较好的结合强度。     

亚太法制计量论坛考察团来华访问

２月２３日至２８日 ,亚太法制计量论坛（ＡＰＬＭＦ）新当选主席大岩彰先生（日本计量院）及秘书处负责人赤松一诚先生（日本产业技术综合研究所）等一行４人组成的考察团来华进行工作访问。考察团先后走访了北京、上海两地 ,访问了国家质检总局、中国计量科学研究院、上海市质量技术监督局、上海市计量院等单位。在此之前 ,该考察团已走访了新加坡、马来西亚、泰国、越南等国的法制计量管理部门。考察团此行的目的主要是了解ＡＰＬＭＦ各成员国的法制计量管理情况 ,听取访问国对ＡＰＬＭＦ工作的意见和建议 ,以便ＡＰＬＭＦ在经济全球化的…     

Anti-adhesive effect of poloxamer-based thermo-sensitive sol-gel in rabbit laminectomy model

Poloxamer-based thermo-sensitive sol-gel has been developed to reduce the incidence of postoperative scar formation at the laminectomy site. The purpose of this study was to evaluate the anti-adhesive effect of poloxamer based thermo-sensitive sol-gel compared to hyaluronate based solution after laminectomy, using a rabbit model. A thermo-sensitive anti-adhesive with a property of sol-gel transition was manufactured by a physical mixture of Poloxamer188/407, Chitosan and Gelatin. The viscosity in different temperatures was assessed. 72 adult New Zealand rabbits underwent lumbar laminectomy and were randomly divided into experimental (treated with the newly developed agent), positive (treated with hyaluronate based solution), and negative control groups. Each group was subdivided into 1 and 4-week subgroups. Gross and histological evaluations were performed to assess the extent of epidural adhesion. The experimental group showed significantly higher viscosity compared to the positive control group and showed a significant increase of viscosity as the temperature increased. Gross evaluation showed no statistically significant differences between the 1- and 4-week subgroups. However, histologic evaluation showed significant differences both in 1- and 4-week subgroups. Although the 4-week histologic results of the experimental and the positive control subgroups showed no significant difference, both subgroups revealed higher value compared to the negative control subgroup with regard to the ratio of adhesion less than 50?%. The new poloxamer based thermo-sensitive agent showed superior efficacy over the hyaluronate based agent at 1?week postoperatively. At 4?weeks postoperatively, there were no statistically significant differences between the two agents, although both showed efficacy over the sham group.     

一种可阻止非特异性蛋白质吸附的新型聚乳酸材料——聚乙二醇接枝聚乳酸

通过直接酰胺化反应,用氨基封端聚乙二醇(H2N-PEG-NH2)对马来酸酐改性聚乳酸(MPLA)进行了本体改性。用红外、核磁和差示扫描技术对改性材料进行了表征,用FITC荧光标记牛血清白蛋白(FITC-BSA)对材料的非特异性吸附进行了检测。结果表明,聚乙二醇被成功地接枝到MPLA上,与聚乳酸(PLA)和MPLA相比,得到的产物(PPLA)明显降低了对牛血清白蛋白的非特异性吸附,仅为PLA的37.3%。     

环氧大豆油化学接枝聚乳酸的制备及其性能

用化学改性方式将环氧大豆油(ESO)与用马来酸酐(MAH)改性过的PLA接枝(MPLA),制备了反应性增容剂ECP并提出其可能的接枝机理.用FT-IR、DSC、SEM等手段表征ECP,研究了制备ECP时4种加料方式和ESO与MAH基团的摩尔比对其接枝率和酸值的影响.结果 表明:在MPLA阶段先加入1/3配方比的ESO,...     

Treatment decisions about lumbar herniated disk in a shared decision-making program

BACKGROUND: An explicit process of collaborative (shared) decision making involving the patient and physician has been recommended for discretionary surgical procedures in which small-area analysis demonstrates high variation not attributable to differences in the patient population in the area. One such example is laminectomy for lumbar herniated disk (HD). An observational study was undertaken to evaluate the impact of an HD videodisk program on patient satisfaction, decision making, and treatment preferences. METHODS: Enrollment occurred in the outpatient offices of surgeons treating Kaiser Permanente (Colorado Region) patients with HD who had indications for surgery. Enrollment took place from May 1993 to December 1995, and follow-up surveys of patients were completed by January 1997. RESULTS: A 6.0% decrease in the undecided group and a 1.3% decrease in the group preferring nonsurgical treatment drove a shift of patients toward laminectomy, from 26.7% to 35.8% (Wilcoxon signed rank test = 349.5, p = .017). Postviewing preference (74.0%) was a better aggregate predictor of the ultimate treatment than previewing preference (70.0%) for laminectomy. DISCUSSION: Viewing the videodisk increased the preference for laminectomy. However, limitations in the data prevented us from determining whether this change in preference was actually reflected in patients' ultimate decisions. The fact that the strongest predictor of choosing surgery was the patient's valuation of his or her condition supports shared decision making, with its emphasis on patient's values. Participation in other videodisk programs has been low; perhaps physicians should ask patients to view these videodisks before their visits.     

Injectable and Pathogen‐Mimicking Hydrogels for Enhanced Protective Immunity against Emerging and Highly Pathogenic Influenza Virus

Seasonal emerging infectious diseases such as influenza A impose substantial risk and need new translational strategies to achieve active immunomodulation. Here, a novel injectable pathogen‐mimicking hydrogel (iPMH) that can enhance both cellular and humoral immune responses is suggested. By the help of poly(γ‐glutamic acid) that has abundant carboxylate groups and dispersion helper function, hydrophobic immunostimulatory 3‐O‐desacyl‐4′‐monophosphoryl lipid A (MPLA) molecules and viral antigens (PR8, W150) can be successfully combined as pathogen‐mimicking adjuvants. Polyelectrolyte complex between the poly(γ‐glutamic acid)‐based adjuvants and collagens generate in situ gel‐forming hydrogel at physiological temperature. When the iPMH are immunized, they act as a pathogen‐mimicking (MPLA, H1N1, H5N1) immune priming center and a depot for continuous stimulation of immune system, resulting in the induction of high levels (8.5 times higher) of antigen‐specific IgG titers in the sera of mice and the increased number of IFN‐γ‐producing cells (7.3 times higher) compared with those in the groups immunized with antigen plus clinically used aluminum gels. Following the intranasal infection of the mouse adapted virus (emerging infectious 2009 H1N1 and highly pathogenic 2006 H5N1) at 50 times the 50% lethal dose, the mice immunized with viral antigens plus iPMH exhibit 100% protective immunity against lethal virus challenge.     

二胺改性聚乳酸的合成与表征

以顺丁烯二酸酐改性聚乳酸(MPLA)和强碱性乙二胺为原料,通过MPLA中酸酐键与乙二胺中伯胺基间的N-酰化反应将乙二胺共价引入到MPLA中,制得乙二胺改性聚乳酸(EMPLA),企图以强碱性乙二胺克服聚乳酸及其降解产物的酸性.本文详细介绍了EMPLA的制备和纯化方法,并利用茚三酮反应、FT-IR、1H-NMR、13C-NMR和DSC对MPLA和EMPLA进行了全面的比较、表征,结果表明,按文中所述之制备技术能成功地将乙二胺共价引入到MPLA中,为进一步测定EMPLA的生物降解性和细胞相容性等性能并最终应用于医学领域奠定了技术基础和物质基础.     

湿态附着力在防腐涂层性能检测中的应用

按标准规定,防腐涂层浸泡一定时间后,若未出现起泡、开裂、脱落等失效现象,评价结果为合格。但部分评价合格的涂层,其附着力已大幅下降,防腐性能大大降低。该文选取浸泡后评价合格的8种防腐涂层,对其干态附着力和酸性环境浸泡后的湿态附着力进行了对比测试。测试结果表明,浸泡后部分涂层的附着力已大幅降低或丧失,金属基体有明显腐蚀特征;部分涂层附着力有所降低;2种常温固化的防腐涂层附着力略有升高。可见,通过对比涂层干/湿附着力,或者跟踪涂层服役过程中附着力的变化,可量化掌握涂层性能的保持状况和发展趋势。     

Influence of connecting plate on construct stiffness of spinal implants and motion of adjacent segments

Abstract

An in vitro biomechanical study compared the influence of connecting plates on construct stiffness and motion of adjacent segments. Twelve porcine lumbar spines were destabilized by laminectomy and instrumented at the L3 and L4 vertebrae by one of three transpedicular screw fixation systems: Cotrel‐Dubousset, Diapason, and a newly designed implant (FPI).

The current study demonstrated that connecting plates significantly increased the construct compression and flexion stiffness and added resistance to axial rotation. The upper intact disc had greater rotational displacement than the unfixed intact spine, but the lower intact disc had more anterior translational displacement. When the construct was flexed with a 1‐second period, the upper intact disc (L2/L3) flexed much more than with a 5‐second period (P<0.05). This study also showed a significant correlation between flexion stiffness and compensatory rotational displacement at the upper intact disc.     

Surface modification of starch based blends using potassium permanganate-nitric acid system and its effect on the adhesion and proliferation of osteoblast-like cells

The surface modification of three starch based polymeric biomaterials, using a KMnO₄/NHO₃ oxidizing system, and the effect of that modification on the osteoblastic cell adhesion has been investigated. The rationale of this work is as follows—starch based polymers have been proposed for use as tissue engineering scaffolds in several publications. It is known that in biodegradable systems it is quite difficult to have both cell adhesion and proliferation. Starch based polymers have shown to perform better than poly-lactic acid based materials but there is still room for improvement. This particular work is aimed at enhancing cell adhesion and proliferation on the surface of several starch based polymer blends that are being proposed as tissue engineering scaffolds.The surface of the polymeric biomaterials was chemically modified using a KMnO₄/HNO₃ system. This treatment resulted in more hydrophilic surfaces, which was confirmed by contact angle measurements. The effect of the treatment on the bioactivity of the surface modified biomaterials was also studied. The bioactivity tests, performed in simulated body fluid after biomimetic coating, showed that a dense film of calcium phosphate was formed after 30 days. Finally, human osteoblast-like cells were cultured on unmodified (control) and modified materials in order to observe the effect of the presence of higher numbers of polar groups on the adhesion and proliferation of those cells. Two of the modified polymers presented changes in the adhesion behavior and a significant increase in the proliferation rate kinetics when compared to the unmodified controls.