聚合物微流控芯片消毒灭菌技术研究进展

聚合物微流控芯片成本低、易加工,目前在医药、生物检测和化学合成等领域得到了普遍应用。以热塑性聚合物聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)和热固型聚合物聚二甲基硅氧烷(polydimethy lsiloxane,PDMS)为基材的高分子聚合物材料因具有较好的生物相容性和光学透明性,已逐渐成为聚合物微流控芯片加工的主导材料,被广泛应用于生物医药类微流控芯片的制备。鉴于该类芯片应用场景的特殊性,需在使用前进行消毒灭菌处理以避免微生物干扰。目前,针对PMMA和PDMS的消毒灭菌方法包括高压蒸汽灭菌、紫外线灭菌、电子束、60Co γ射线辐射灭菌、超临界二氧化碳灭菌、乙醇消毒、环氧乙烷灭菌、过氧化氢低温等离子体灭菌、绿原酸消毒、清洗剂消毒。本文从基本原理、消毒灭菌方法、应用场景等方面,回顾和总结了相关技术在PMMA和PDMS基体微流控芯片中的实现方法,并在芯片材质、适用范围等方面分析了所适用的消毒灭菌方法,为以聚合物为基材的生物医药类微流控芯片的消毒灭菌提供有益参考。     

短波紫外线对几种常见浅部真菌生长的影响

目的 了解短波紫外线对几种常见浅部真菌生长的影响.方法 将红色毛癣菌、须癣毛癣菌、犬小孢子菌、絮状表皮癣菌、白念珠菌、光滑念珠菌、近平滑念珠菌、热带念珠菌、克柔念珠菌、青霉、短帚霉、枝顶孢霉接种在沙氏培养基上,按不同照射功率、不同照射距离和不同照射时间分组用紫外线灯进行照射,观察记录照射后菌落的生长情况,并在透射电镜下观察菌丝或孢子的形态结构变化.结果 犬小孢子菌、絮状表皮癣菌、白念珠菌、近平滑念珠菌、克柔念珠菌经照射后停止生长;红色毛癣菌、须癣毛癣菌、光滑念珠菌、热带念珠菌、短帚霉和枝顶孢霉在某些照射条件下可以继续生长,但生长速度减缓.结论 短波紫外线对常见浅部真菌有不同程度的杀灭和抑制作用,该作用的大小与紫外线照射强度和照射时间成正比,与照射距离成反比.     

不同消毒方法对生物化PET 人工韧带的生物力学影响

目的:探讨环氧乙烷、高压蒸汽、60Co照射三种消毒方法,对生物化PET人工韧带的生物力学影响,为选取合适的消毒灭菌方法提供实验依据。方法:以表面改性的聚对苯二甲酸乙二醇酯纤维为材料,制备生物化PET人工韧带,分别给予环氧乙烷熏蒸、高压蒸汽、60Co照射消毒处理,并设未作消毒处理的空白对照组,分别进行生物力学测试,对测量结果行统计学比较分析。结果:高压蒸汽消毒后,韧带所能承受的最大拉力及第一次破裂力降低,且与对照组间的差异均有统计学意义(P<0.05);60Co照射消毒后,韧带所能承受的最大拉力降低,与对照组间的差异有统计学意义(P<0.05),但第一次破裂力的差异不明显(P>0.05);环氧乙烷消毒处理后,最大拉力、第一次破裂力与对照组之间无明显差异(P>0.05);各组间断裂伸长率无明显差异(P>0.05)。结论:高压蒸汽消毒后韧带样品的生物力学性能降低比较明显;采用60Co射线消毒方法对产品的力学性能影响较小,但进一步的消毒方法改进可能更为理想;环氧乙烷消毒法可作为生物化PET人工韧带的有效消毒方法。     

UV和过硫酸钠联合消毒强化饮用水中微生物的灭活效果

为了研究紫外线联合消毒的协同作用,获得更高效的饮用水不易灭活微生物消毒手段,本研究采用紫外线消毒及过硫酸钠消毒的方式,研究其对大肠杆菌以及枯草芽孢杆菌的灭活效果,通过平板计数法对其灭活效果进行定量评估。结果表明:过硫酸钠协同紫外线消毒,对大肠杆菌灭活有明显效果(紫外光强113.0μW/cm2,过硫酸钠浓度为0.5 mmol/L情况下照射10 min,灭活率超过6 lg);单独过硫酸钠对枯草芽孢杆菌基本无灭活效果,过硫酸钠浓度为0.5 mmol/L情况下10 min的灭活率仅为0.98个对数级;单独紫外线消毒对枯草芽孢杆菌的灭活效果较好,光强为113.0μW/cm2、照射时间10 min可达3.48个对数级;采用联合消毒时,过硫酸钠与紫外线联合消毒在一定程度上对灭活枯草芽孢杆菌有积极影响,最佳情况下可较单独UV消毒和单独过硫酸钠消毒分别增加0.90和3.40个对数级。紫外过硫酸钠联合消毒有望成为一种高效的饮用水微生物消毒方式,并在给水领域得到广泛应用。     

卡脱利亚兰的组织培养

植物名称:卡脱利亚兰(Cattleya aurantiaca) 材料类别:从栽培于人工气候室的植株上,采取已停止生长、外形似梭子的绿色果实,先在肥皂水中洗净,然后用70％乙醇消毒1分钟,再放入0.1％升汞溶液中消毒5分钟,在无菌条件下用灭菌水洗涤5次,切开果实,取果内白色粉末状种子进行接种。培养条件:培养基为MS或修改的1/2MS,附     

双链季铵盐复合邻苯二甲醛消毒液研制及比较

通过将邻苯二甲醛、双链季铵盐与相应助剂进行复配,制备一种新型的复合消毒剂,并进行灭菌消毒试验、清洗效果及稳定性试验。实验证明邻苯二甲醛复合消毒剂浓度在2000 mg/L时对白色念珠菌的杀灭效果达100%。该复合消毒剂原液经45℃恒温放置15 d,邻苯二甲醛的下降率为2.26%左右,稳定性和杀菌能力有明显提高。对油脂清洗率达98%以上,具有消毒清洗双功能。因此邻苯二甲醛复合消毒剂对消化内镜消毒灭菌效果高,耗时短,用法简便,并可降低对医务人员健康的危害性,是值得在医院临床推广使用的高效消毒剂。     

不同消毒方法对家蚕微粒子的存活和侵染力影响

家蚕微粒子病是家蚕Bombyx mori的重要病害,探索其消毒杀灭方法对蚕业生产具有重要意义。本研究采用微粒子染色法和添食家蚕侵染法测试了温度、紫外线和消毒剂处理108个/mL家蚕微粒子后对家蚕微粒子的消杀作用,结果表明：温度对家蚕微粒子虫灭活温度为60℃处理30 min以上;使用20 wx功率紫外灯距离50 cm照射12 min及以上时,微粒子死亡率为47.70%,对家蚕侵染率为0;三氯异氰脲酸800 mg/L及以上浓度处理6 min以上家蚕微粒子死亡率为100%,对家蚕的侵染率为0;戊二醛癸甲溴铵200 mg/L及以上浓度处理6 min以上家蚕微粒子死亡率为100%,对家蚕的侵染率为0。3种消毒方法中温度法主要用于小型蚕具消杀微粒子;紫外线用于蚕业辅助设施的表面微粒子的消杀;三氯异氰脲酸和戊二醛癸甲溴铵均表现出较好的消杀效果,其中戊二醛癸甲溴铵较含氯的消毒剂三氯异氰脲酸稳定性强,刺激性小,对养蚕的金属腐蚀性小,可作为含氯消毒剂的部分替代使用。本研究结果可为蚕业生产中消杀微粒子提供参考。     

100～700 mL液体培养基的微波灭菌效果观察

为研究家用微波炉对少量液体培养基的灭菌效果,对100 -700 mL液体培养基采取微波分别进行灭菌,测定其灭菌时间,并对达到灭菌效果的培养基通过接种不同细菌进行质检.结果显示100、200、300、400、500、600、700 mL液体培养基分别在4.5、5.0、7.0、9.0、12.0、19.0、25.0 min达到最有效的灭菌效果.室温保存15 d仍无细菌生长.枯草杆菌黑色变种芽胞菌测试无菌生长.金黄色葡萄球菌、大肠埃希菌及普通变形杆菌在液体培养基里的生长现象、特种后细菌的菌落和形态染色特征及其生化反应均无明显差异.实验表明2 450 MHz,700 W的微波炉对100 - 700 mL的液体培养基不但能快速达到有效的灭菌效果,且营养成分不会被破坏.     

红锥不同外植体消毒技术初探

以红锥种子、茎段为材料,进行外植体消毒试验。结果表明,种子灭菌的条件:75%酒精5~15min+0.1%HgCl230~40min(不剥壳去皮),75%酒精1min+0.1%HgC220min(剥壳去皮),这2种处理污染率均较低,种子发芽率相差不大;茎段用0.1%升汞+20%次氯酸钠组合消毒效果最好,在0.1%升汞+20%次氯酸钠组合消毒时间为8min+5min时污染率最低,平均仅为28.89%。     

红锥不同外植体消毒技术初探

以红锥种子、茎段为材料,进行外植体消毒试验。结果表明,种子灭菌的条件:75%酒精5~15min+0.1%HgCl230~40min(不剥壳去皮),75%酒精1min+0.1%HgC220min(剥壳去皮),这2种处理污染率均较低,种子发芽率相差不大;茎段用0.1%升汞+20%次氯酸钠组合消毒效果最好,在0.1%升汞+20%次氯酸钠组合消毒时间为8min+5min时污染率最低,平均仅为28.89%。     

Successful disinfection of trumpet mouthpieces using domestic steam disinfection

There have been numerous reports in the literature describing the diversity of microbial flora isolated from woodwind and brass instruments, with potential infection risks for players, especially when such instruments are shared. Steam disinfection has become established as a trusted method of decontamination; however, there have been no reports on the employment of this technology to disinfect parts of musical instruments, hence it was the aim of this study to examine the fate of bacterial and yeast pathogens on artificially contaminated trumpet mouthpieces and to evaluate whether such disinfection is an effective method of disinfection for such instrument parts. Trumpet mouthpieces were artificially contaminated with 18 microbial strains (17 bacteria from four genera (Enterococcus, Escherichia, Staphylococcus and Streptococcus) and one yeast (Candida)), each at an inoculum density of approximately 1·5 × 10⁷ colony forming units and subjected to a disinfection cycle. The experiment was repeated including 50% (v/v) sterile sputum as soil. No bacteria or yeast organisms were recovered post disinfection, including following recovery and with nonselective cultural enrichment techniques.     

Chlorine disinfection of Francisella tularensis

Aims: To determine the range of free available chlorine (FAC) required for disinfection of the live vaccine strain (LVS) and wild‐type strains of Francisella tularensis. Methods and Results: Seven strains of planktonic F. tularensis were exposed to 0·5 mg·l^?1 FAC for two pH values, 7 and 8, at 5 and 25°C. LVS was inactivated 2 to 4 times more quickly than any of the wild‐type F. tularensis strains at pH 8 and 5°C. Conclusions: Free available chlorine residual concentrations routinely maintained in drinking water distribution systems would require up to two hours to reduce all F. tularensis strains by 4 log₁₀. LVS was inactivated most quickly of the tested strains. Significance and Impact of the Study: This work provides contact time (CT) values that are useful for drinking water risk assessment and also suggests that LVS may not be a good surrogate in disinfection studies.     

Concepts in disinfection of bacterial populations

Bacteria are responsible for a range of human diseases that are difficult to clear for a variety of reasons. Understanding the multilayered mechanisms that protect pathogens is of primary importance for developing effective treatments. Research over the past several decades has shown that bacteria can seek protected environments passively by avoiding deadly environments or actively by manipulating their phenotypic expression and gathering in structured biofilm communities. This article outlines the main tolerance mechanisms that have been studied and describes many of the mathematical models that indicate directions for new treatments. It is essential to understand that bacterial populations exploit a range of mechanisms to survive challenges and the mechanisms are often intertwined. This provides an opportunity for mathematical modeling to help provide insights into experiments that may uncouple particular mechanisms or optimize treatments.     

Moist-heat disinfection of pathogenic Acanthamoeba cysts

The effect of moist-heat in the disinfection of pathogenic Acanthamoeba cysts was investigated. Temperatures of 56°C or 60°C were not effective in killing cysts of A. polyphaga even after a contact time of 60 min, A 4 log reduction in viability was achieved within 15 min at 65°C and 2 min at 70°C giving decimal reduction rates (D-values) of 3·75 min and 30 s respectively. The ability of a commercial moist-heat contact lens disinfection unit to kill 1 times 10⁵ cysts of Acanthamoeba isolated from contact lens storage cases was also shown. Holding temperatures inside the cases of 65°C for 5·5 min and 70°C (the maximum temperature obtained) for 1 min were recorded during the disinfection cycle.