超滤法测定表面活性剂临界胶束浓度

对超滤法测定表面活性剂的临界胶束浓度(CMC)的单点式超滤法、超滤曲线法、双点式超滤法进行了研究,比较了理想与真实超滤曲线,对超滤膜用于超滤法测定CMC的适用性及容积效应进行了考察.初步探讨了用双点式超滤法代替作超滤曲线法测定CMC的可行性和准确性,并与单点式超滤法进行了比较.试验结果表明,用双点式超滤法测定CMC具有准确性较高、操作简便、节省时间和节约样品用量等优点.用双点法测得的SDS和SLAS的CMC分别为6.70mmol/L和1.40mmol/L;与超滤曲线法得到的CMC相比,偏差分别为2.9%和3.4%.     

人表皮生长因子与碱性成纤维细胞生长因子纳米缓释剂对成纤维细胞的影响

目的:制备碱性成纤维细胞生长因子(bFGF)、人表皮生长因子(EGF)可降解缓释微球,考察其生物活性的保存情况,以及它们对成纤维细胞的作用。方法:采用改良的乳化冷凝法交联制备复合bFGF、EGF的明胶缓释微球,将它们加入成纤维细胞的培养液中,用细胞计数法、四甲基偶氮唑盐微量反应比色法(MTT法)测定细胞增殖情况。结果:复合bFGF、EGF的缓释微球平均粒径(11.32±3.64)μm;培养1天后各组细胞计数、吸光度(A)值差异均无显著性;5天后,两种生长因子缓释微球组细胞计数、吸光度(A)值明显高于对照组;7天后,两种生长因子缓释微球组值仍高于其它组,但差异无显著性。结论:复合bFGF、EGF的缓释微球制备工艺简便,成球性好;能较长时间地持续释放活性bFGF、EGF,可促进成纤维细胞的增殖。     

Effect of rhBMP‐2 and VEGF in a vascularized bone allotransplant experimental model based on surgical neoangiogenesis

We have demonstrated survival of living allogeneic bone without long‐term immunosuppression using short‐term immunosuppression and simultaneous creation of an autogenous neoagiogenic circulation. In this study, bone morphogenic protein‐2 (rhBMP‐2), and/or vascular endothelial growth factor (VEGF), were used to augment this process. Femoral diaphyseal bone was transplanted heterotopically from 46 Dark Agouti to 46 Lewis rats. Microvascular repair of the allotransplant nutrient pedicle was combined with intra‐medullary implantation of an autogenous saphenous arteriovenous (AV) bundle and biodegradable microspheres containing buffer (control), rhBMP‐2 or rhBMP‐2 + VEGF. FK‐506 given daily for 14 days maintained nutrient pedicle flow during angiogenesis. After an 18 weeks survival period, we measured angiogenesis (capillary density) from the AV bundle and cortical bone blood flow. Both measures were greater in the combined (rhBMP‐2 + VEGF) group than rhBMP‐2 and control groups (p < 0.05). Osteoblast counts were also higher in the rhBMP‐2 + VEGF group (p < 0.05). A trend towards greater bone formation was seen in both rhBMP2 + VGF and rhBMP2 groups as compared to controls (p = 0.059). Local administration of VEGF and rhBMP‐2 augments angiogenesis, osteoblastic activity and bone blood flow from implanted blood vessels of donor origin in vascularized bone allografts. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 561–566, 2013     

Local cooling reduces regional bone blood flow

Local cooling is very common after bone and joint surgery. Therefore the knowledge of bone blood flow during local cooling is of substantial interest. Previous studies revealed that hypothermia leads to vasoconstriction followed by decreased blood flow levels. The aim of this study was to characterize if local cooling is capable of inducing reduced blood flow in bone tissue using a stepwise‐reduced temperature protocol in experimental rabbits. To examine bone blood flow we utilized the fluorescent microsphere (FM) method. In New Zealand white rabbits one randomly chosen hind limb was cooled stepwise from 32 to 2°C, whereas the contra lateral hind limb served as control. Injection of microspheres was performed after stabilization of bone and muscle temperature at each temperature level. Bones were removed, dissected and fluorescence intensity was determined to calculate blood flow values. We found that blood flow of all cooled regions decreased relative to the applied external temperature. At maximum cooling blood flow was almost completely disrupted, indicating local cooling as powerful regulatory mechanism for regional bone blood flow (RBBF). Postoperative cooling therefore may lead to strongly decreased bone blood flow values. As a result external cooling has capacity to both diminish bone healing and reduce bleeding complications. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1820–1827, 2013     

糖皮质激素联合醋酸亮丙瑞林微球对子宫内膜异位症腹腔镜手术患者的疗效及预后分析

目的 分析糖皮质激素联合醋酸亮丙瑞林微球对子宫内膜异位症（EMS）腹腔镜手术患者的疗效及预后的影响。方法 选取2020年2月—2022年3月青岛大学附属青岛市海慈医院收治的228例EMS患者,以随机数字表法分为对照组和研究组,每组114例。两组患者均接受腹腔镜手术治疗,对照组腹部皮下注射醋酸亮丙瑞林微球,研究组在对照组基础上口服糖皮质激素,持续治疗3个月评价疗效。对比两组临床疗效、子宫内膜动脉血流动力学、性激素、炎症因子及药物不良反应,比较两组随访期间复发及妊娠成功情况。结果 研究组总有效率高于对照组（P <0.05）。研究组治疗前后子宫动脉收缩期峰值流速、搏动指数、阻力指数、雌二醇、黄体生成素、促卵泡生成素、白细胞介素-4、肿瘤坏死因子-α、白细胞介素-17的差值均高于对照组（P <0.05）。两组总不良反应发生率比较,差异无统计学意义（P>0.05）。研究组复发率低于对照组（P <0.05）,妊娠成功率高于对照组（P <0.05）。结论 糖皮质激素联合醋酸亮丙瑞林微球用于EMS腹腔镜手术患者可增强疗效,改善子宫内膜动脉血流动力学及性激素水平,抑制炎症因...     

在CPS微球表面实现N-羟基邻苯二甲酰亚胺的同步合成与固载及固体催化剂催化氧化性能初探

通过分子设计的构思,仅通过两步大分子反应,便实现了N-羟基邻苯二甲酰亚胺(NHPI)在交联聚苯乙烯(CPS)微球表面的同步合成与固载,并制得了非均相催化剂微球CPS-NHPI。以氯化偏苯三酸酐(TMAC)为试剂、Lewis酸为催化剂,通过Friedel-Crafts酰基化反应,先将邻苯二甲酸酐(PA)基团键合在CPS微球表面,得到改性微球CPS-PA;再与盐酸羟胺进行酰亚胺反应,制备出固载有NHPI基团的非均相催化剂微球CPS-NHPI。重点研究了CPS微球表面发生Friedel-Crafts酰基化反应的影响因素。采用红外光谱(FT-IR)及扫描电子显微镜(SEM)等对微球CPS-NHPI进行表征,将微球CPS-NHPI分别用于分子氧氧化乙苯及环己烷两种烃类物质的氧化过程,初步考察了该微球的催化活性。研究结果表明,对于微球CPS与TMAC之间的Friedel-Crafts酰基化反应,适宜的溶剂为氯仿与N,N-二甲基乙酰胺(DMAC)混合溶剂(氯仿与DMAC的体积比为7:3),适宜的Lewis酸催化剂为SnCl₄。初步探索实验表明,催化剂微球CPS-NHPI与Co(OAc)₂ 所构成的共催化体系,在分子氧氧化乙苯及环己烷的催化氧化过程中,都表现出了良好的催化活性,温和条件下,反应35 h时乙苯氧化为苯乙酮的转化率可达37%,反应30 h时环己烷氧化为环己酮的转化率可达21%。     

Reactive hyperemia following total and subtotal coronary occlusion in the awake dog

Summary This study examined the reactive hyperemia following total and subtotal coronary artery occlusions. Studies were carried out in awake dogs with electromagnetic flowmeters and hydraulic occluders on the left circumflex coronary artery; the regional distribution of perfusion was examined with radionuclide-labeled microspheres. Reactive hyperemia following total and subtotal occlusions resulted in similar mean blood flow debt repayments of 451±34% and 492±51%, respectively. However, the distribution of perfusion was markedly different, with the ratio of subendocardial to subepicardial blood flow being 1.77±0.22 after total occlusion and 4.14±0.73 after subtotal occlusion (p<0.01). Further examination of the pattern of perfusion during reactive hyperemia demonstrated a direct relationship between the local blood flow debt and blood flow during the subsequent reactive hyperemia. These data demonstrate that coronary reactive hyperemia does not occur uniformly throughout the distribution of the vascular bed served by the previously occluded artery, but rather is coupled to the degree of hypoperfusion during the preceding occlusion.This study was supported by U.S. Public Health Service Grants HL-20598 and HL-21872 from the National Heart, Lung and Blood Institute.     

In vitro comparison of fracture strength of experimental hollow and solid design zirconia dowels

Purpose: The aim of this study was to evaluate the fracture strength of experimental hollow and solid design zirconia dowels. Materials and Methods: Three types of dowels (fiber‐reinforced composite [FRC], hollow design, and solid design zirconia dowels) were tested in the study (n = 10). A three‐point bending method was conducted, and a load was applied until fracture. The values were recorded as Newtons (N) and then converted to megapascals (MPa) according to the diameter of the dowels. Statistical analyses were performed using one‐way ANOVA and Tukey HSD tests. The significance was set at p < 0.05. Results: The mean fracture strength of the hollow design zirconia dowels was significantly higher (960.72 MPa) than solid zirconia dowels (741.78 MPa) and FRC dowels (687.64 MPa) (p < 0.05). Conclusions: The hollow design zirconia dowel seems to have sufficient fracture strength for anterior restorations. This design may be beneficial to access the apical region when retreatment is necessary, without any dowel‐removing procedure.     

载乳铁蛋白壳聚糖微球/nHA/Co复合材料的制备

目的:制备载乳铁蛋白壳聚糖微球/nHA/Co复合材料作为组织工程材料拟修复骨缺损。方法:通过乳化交联法法制备载乳铁蛋白壳聚糖微球,化学沉淀法制备纳米羟基磷灰石,改良酸酶法提取Ⅰ型胶原,应用京尼平交联制备复合材料,SEM检测材料的微观结构,测定壳聚糖微球对乳铁蛋白的载药率和包封率。结果:复合材料及各组成成份扫描电镜观察均具有较好的微观形态,壳聚糖微球对乳铁蛋白的载药率为(1.06±0.06)%,包封率为(88.2±2.9)%。结论:载乳铁蛋白壳聚糖微球/nHA/Co复合材料具有较好的微观形态。     

Total hip arthroplasty in Denmark

Background The annual number of total hip arthroplasties (THA) has increased in Denmark over the past 15 years. There is, however, limited detailed data available on the incidence of THAs.

Methods We calculated the incidence rates (IR) of primary THA and revision in Denmark between 1996 and 2002 and estimated the demands for primary THA in Denmark until 2020. We used data from the Danish Hip Arthroplasty Registry, a nationwide and popula-tion-based clinical database, to identify patients who had undergone primary THA (n = 37 144) or revision arthroplasties (n = 6 446). Age and sex-specific data on the Danish population were obtained from the StatBank Denmark. All IRs were standardized according to two standards, i.e. the Danish population in 1996 and the European standard population (18 age groups). The future demands for primary THA were estimated using the age and sex-specific incidence of primary THA for 2002 as a reference, and taking into account the expected changes in the age distribution of the population and the trend in IRs seen in Denmark between 1996 and 2002.

Results The annual overall standardized IRs of primary THAs and revisions increased from 101 (95% confidence interval (CI): 97.6–104) to 134 (CI: 131–138) and from 19.2 (CI: 17.9–20.5) to 21.1 (CI: 19.8–22.4) per 100 000 inhabitants from 1996 to 2002, respectively (IRs adjusted to the Danish population in 1996). The IRs of primary THAs and revisions increased by 30% and 10% during this period. The relative increase in IRs of primary THAs was found to be similar in both women and men. The increase was higher among patients aged 50–59 years, however. Furthermore, a decrease in IRs was seen in patients who underwent primary THA due to rheumatoid arthritis. IRs of primary THAs have been estimated to increase by 22% in 2020 compared with 2002, based only on the expected changes in the age distribution of the population. However, assuming that the annual age and sex-independent increase in the IRs seen in the period 1996–2002 will continue, the IR of primary THA is estimated to increase by as much as 210% in 2020.

Interpretation The overall annual standardized IRs of primary THAs and revisions in Denmark increased during the period from 1996 to 2002. Moreover, the demands for THA procedures in the coming decades may exceed the current capacity due to the ageing population and a continued age and sex-independent increase in surgical activity.