镀银导电纤维的制备和性能

对短切聚酯纤维进行化学镀银,制备了用于导电高分子材料的导电填料,探讨了氨水浓度、装载量及稳定剂对纤维化学镀银的影响。实验表明,φ=0.10的氨水有利于化学镀银;通过调整装载量,可提高纤维的增重量率和硝酸银的利用率;稳定剂的加入可阻止镀液自分解,但对包覆层的均匀性和致密性有影响。电性能测试表明,镀银纤维的体积电阻率可达3.35×1-0 3Ω.cm,以其作为导电橡胶填料,当含量为w=0.40时,其电阻率为1.54×1-0 1Ω.cm。     

三种螺距对种植体初期稳定性影响的有限元研究

目的：利用即刻负载有限元模型,研究种植体不同螺纹螺距因素对初期稳定性的影响。方法：利用Pro／E软件、Hypermesh软件及ABAQUS有限元软件,建立四类种植体即刻负载的三维有限元模型,比较3种螺纹螺距（0．8mm、1．6mm、2．4mm）在分别垂直和水平加载时,对种植体初期稳定性的影响。结果：对不同螺纹螺距种植体来说,垂直加载和水平加载时0．8mm螺距螺纹种植体微动最小,2．4mm螺距螺纹种植体微动最大。结论：螺纹的螺距对垂直相对位移有影响,对水平相对位移影响不大。随着螺距的增加,种植体对抗垂直向载荷的抵抗力减弱。水平加载时,螺纹的螺距对颈部微动影响不明显。     

纳米喷雾干燥技术用于生地黄低聚糖微粉的制备工艺研究

目的采用纳米喷雾干燥技术制备载药量高、收率高、吸湿性好的生地黄低聚糖微粉。方法采用B-90纳米喷雾干燥仪制备生地黄低聚糖微粉,采用单因素试验考察后,通过正交试验设计,以平均粒径、收率和吸湿率为评价指标,考察进风口温度、喷雾干燥效率和药液质量分数对制备工艺的影响并优选最佳制备工艺。结果正交试验结果得到最佳制备工艺条件:进风口温度为110℃、喷雾干燥效率为50%、药液质量分数为1.0%,最终得到了载药量为30%、收率为89%、吸湿性良好的生地黄低聚糖微粉,微粉形态稳定。结论采用纳米喷雾干燥技术制备生地黄低聚糖的工艺稳定可行,得到的微粉质量良好,优于传统的喷雾干燥。     

参乌胶囊对小鼠抗疲劳作用的实验研究

目的研究参乌胶囊对小鼠的抗疲劳作用,为参乌胶囊的进一步开发和应用提供依据。方法 SPF级雄性小鼠50只,随机分为5组,分别为空白对照组,阳性对照组,参乌胶囊高、中、低剂量组(900.0μg/g、450.0μg/g、225.0μg/g),连续灌胃给药14天,通过小鼠负重游泳实验,测定小鼠运动后血乳酸(LD)、尿素氮(BUN)、肝糖原、肌糖原、乳酸脱氢酶(LDH)含量以及小鼠负重游泳力竭时间等指标。结果与空白对照组比较,参乌胶囊可以明显延长小鼠力竭游泳时间,提高肝糖原、肌糖原含量,增强LDH活性,降低血清BUN的浓度,差异均有统计学意义(P0.05,P0.01)。结论参乌胶囊具有一定的缓解疲劳作用。     

地黄饮子对海马神经元损伤即早基因c-jun和c-fos表达的影响

目的:探讨古方地黄饮子对β淀粉蛋白(Aβ25-35)所致离体海马神经元损伤时即早基因c-iun和c-fos表达的调控作用.方法:把体外培养的大鼠海马神经细胞分为正常组、模型组、VitE脑脊液对照组、地黄饮子脑脊液低、中、高剂量组,6组分别加入正常培养液、正常脑脊液、VitE脑脊液、中药脑脊液低、中、高剂量,继续孵育2h.然后除正常组加入等量培养液外,其他各组加入经老化处理的Aβ25～35(终浓度为10μmol/L)共同孵育1h,胰蛋白酶消化,离心收集细胞,提取总RNA.应用RT-PCR和琼脂糖凝胶电泳方法测定c-iun和c-fos基因的表达.结果:地黄饮子脑脊液能剂量依赖性地降低受损海马神经元c-iun和c-fos基因的表达.结论:地黄饮子脑脊液能有效降低海马神经元受到神经毒损伤时的应激反应,降低c-jun、c-fos基因对神经元的损伤作用.     

难溶性药物与介孔二氧化硅纳米粒载体的相互作用对于释放速率的影响

目的 研究介孔二氧化硅纳米粒（MSN）载体与装载的难溶性药物间的相互作用,探索对释放速率具有重要影响的因素,归纳总结可预测难溶性药物-MSN给药系统释放行为的数学模型。方法 以溶胶凝胶法制备的MSN作为载体,通过溶剂挥干法进行药物装载,利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）分析载体的外观形貌及孔道结构,通过比表面积分析仪研究载体的比表面积及孔径分布。选取载药量及药物的氢键受体数量作为因素进行释放行为分析,通过Design Expert软件进行2因素3水平析因设计,完成体外释放实验;2、24 h累积释放度作为因变量,拟合数学模型。结果溶胶凝胶法制备的MSN为均一的球形,粒径约为400 nm,孔道呈放射状,孔径均一为3.6 nm。拟合模型显示,载药量比氢键受体数量对2 h累计释放度影响更大,随着载药量的增加,2 h累计释放度逐渐下降;在研究范围内,氢键受体数为6,载药量为50%具有最小的2 h累计释放度,为50.31%。24 h累计释放度则根据载药量的不同随着氢键受体数的改变呈现相反趋势,当载药量较低时,与氢键受体数呈正相关;当载药量较高时,与氢键受体数呈负相关。氢键受体数为6,载药量小于10%时具有最大的24 h累计释放度,可达99.44%。结论 相对药物的氢键受体数量,载药量对于难溶性药物-MSN给药系统的速缓释放具有重要调控作用,低载药量可以实现药物的2 h快速释放及24 h完全释放,高载药量则反之。     

Marginal bone level change during sequential loading periods of partial edentulous rehabilitation using immediately loaded self-tapping implants: a 6.5-year retrospective study

PURPOSEA large number of studies have suggested the practicability and predictability of immediate implant function, but few studies have reported marginal bone level changes during sequential loading periods. The purpose of this study was to evaluate the marginal bone remodeling of immediately loaded self-tapping implants both at each time point and during each loading period between two time points.MATERIALS AND METHODSThe patients included in this retrospective study were treated with immediately loaded NobelSpeedy Replace implants between August 2008 and July 2009. Differences in the marginal bone level (MBL) at each time point and the marginal bone level change (ΔMBL) between two time points were analyzed with Bonferroni correction (P < .05).RESULTSOverall, 24 patients (mean age, 47.3 ± 12.8 years) with 42 immediately loaded implants and a median follow-up of 6.5 years (IQR, 67.8 months) were included. The cumulative survival rate after 10 - 12 years was 95.2%. Continuous but slow marginal bone loss was observed during long-term follow-up. MBL at both 7.5 years and 11 years was significantly lower than that at loading, 6 months, 2 years and 4 years (P < .05). No bone loss difference was found in any period before 4 years of follow up (P > .05). The loading period of 4 years to 7.5 years showed the largest ΔMBL compared to those of other time periods (P < .05).CONCLUSIONSlight bone loss occurred continuously, and more radical changes of marginal bone can be observed during the period of 4-7.5 years. Thus, long-term effective follow-up of immediately loaded implants is needed.     

Effects of organophosphorus pesticides and their ozonation byproducts on gap junctional intercellular communication in rat liver cell line.

The effects of organophosphorus pesticides (OPs), oxons and their ozonation byproducts on gap junctional intercellular communication (GJIC) on cultured BRL cell line were investigated using scrape loading and dye transfer (SL/DT) technique. The neutral red uptake assay was used to identify the non-cytotoxic levels of diazinon, parathion and methyl-parathion applied to GJIC assay. The concentration-dependent inhibition of GJIC was observed over a range of 50-350 mg/l diazinon, parathion and methyl-parathion after 90 min incubation compared with the vehicle control. However, oxons and ozonation byproducts of OPs had no inhibition effect on GJIC at any of the concentrations tested. The inhibition of GJIC by OPs was reversible after removal of the tested pesticides followed by incubation with fresh medium. The present study suggested that the ozonation treatment could be used for the detoxification of drinking water and food crops contaminated with diazinon, parathion and methyl-parathion without formation of GJIC toxicity.     

华法林负荷量法抗凝治疗短暂性脑缺血发作的研究

目的 :观察华法林抗凝治疗短暂性脑缺血发作 (TIA)的安全性和疗效。方法 :2 0 0 3年 1月至2 0 0 4年 1月入院的TIA病人 ,适合抗凝治疗者 ,按Roberts依年龄调整华法林负荷量指南用药 ,对照组为 2 0 0 2年 1月至 2 0 0 3年 1月住院的TIA病人 ,并剔除用肝素治疗的病人。结果 :华法林组 10d内无脑卒中发生 ,仅有 4人次再次TIA ,未发现有出血者 ;对照组 10d内脑梗死 6例 ,再次TIA 12人次 ,华法林组于TIA发作后 10d内发生脑梗死及再次TIA较对照组低 (P <0 .0 5 )。结论 :按Roberts华法林负荷量指南抗凝治疗TIA优于非抗凝治疗 ,而且安全