Ultrasound-mediated transdermal drug delivery of fluorescent nanoparticles and hyaluronic acid into porcine skin in vitro

Transdermal drug delivery(TDD) can effectively bypass the first-pass effect. In this paper, ultrasound-facilitated TDD on fresh porcine skin was studied under various acoustic parameters, including frequency, amplitude, and exposure time. The delivery of yellow–green fluorescent nanoparticles and high molecular weight hyaluronic acid(HA) in the skin samples was observed by laser confocal microscopy and ultraviolet spectrometry, respectively. The results showed that,with the application of ultrasound exposures, the permeability of the skin to these markers(e.g., their penetration depth and concentration) could be raised above its passive diffusion permeability. Moreover, ultrasound-facilitated TDD was also tested with/without the presence of ultrasound contrast agents(UCAs). When the ultrasound was applied without UCAs,low ultrasound frequency will give a better drug delivery effect than high frequency, but the penetration depth was less likely to exceed 200 μm. However, with the help of the ultrasound-induced microbubble cavitation effect, both the penetration depth and concentration in the skin were significantly enhanced even more. The best ultrasound-facilitated TDD could be achieved with a drug penetration depth of over 600 μm, and the penetration concentrations of fluorescent nanoparticles and HA increased up to about 4–5 folds. In order to get better understanding of ultrasound-facilitated TDD, scanning electron microscopy was used to examine the surface morphology of skin samples, which showed that the skin structure changed greatly under the treatment of ultrasound and UCA. The present work suggests that, for TDD applications(e.g., nanoparticle drug carriers, transdermal patches and cosmetics), protocols and methods presented in this paper are potentially useful.     

三氯化六氨合钴浸提–分光光度法测定土壤中阳离子交换量

采用三氯化六氨合钴震荡提取,分光光度计测定土壤阳离子交换量.考虑pH对实验结果的影响,加入浸提液前所有土壤样品加固体NaOH改变土壤pH为碱性后,再进行分析;当样品阳离子交换量结果过高时采用减少称样量作为高含量样品的测定手段.实验结果表明,优化后方法检出限为8 mmol/kg;用该方法测定不同阳离子含量的土壤标准样品,...     

PDCA循环法在地质勘查实验室安全隐患排查整改中的应用

为了提高隐患排查整治效果,防止安全事故发生,将PDCA(计划、执行、检查和处理)循环法运用到地质勘查单位实验室安全管理工作当中,对实验室安全隐患进行分类排查与整治.通过PDCA循环法,辨识安全隐患、监视隐患整改、评价整改效果、实现闭环管理,实验室安全管理的思路和流程更加清晰顺畅,总结了经验,提高了管理效率,实验室安全隐...     

超声法在检测高压开关柜内局部放电的应用

高压开关柜是电力系统中的关键设备之一,其内部电气元件分布繁多、排列紧密、绝缘裕度很小,易出现局部放电现象。为此以准确定位局部放电的位置为目的,提出了基于梯度收缩法的超声波定位算法,具体介绍该方法的基本原理、检测方法和判断结果。将此算法用于某企业的35 kV真空开关柜局部放电检测中,检测结果表明,该方法对高频干扰下的局部放电现象的检测更为精确有效,也为高压开关柜的故障检测以及安全运行提供了技术依据。     

从江苏移动的经营现状看中国移动通信集团的发展及其对策

本文分析了中国移动通信集团公司在我国特别是江苏功南地区发展的现状，并针对其存在问题提出了相应的若干对策，供有关各方参考。     

发展电子邮政的前瞻

电子产的日益发展给邮政部分发展电子邮政带来了无限商机,在对电子邮政的发展进行构思的基础上,提出了发展电子邮政的对策,并对发展电子邮政进行了展望。     

用户用邮行为分析及其对策

系统地讨论了用户用邮行为的规律,提出了若干相应的引发用户用邮的对策。     

发展电子邮政的前瞻

电子商务的日益发展给邮政部门发展电子邮政带来了无限商机。在对电子邮政的发展进行构思的基础上 ,提出了发展电子邮政的对策 ,并对发展电子邮政进行了展望     

浅谈邮政技术人才的培养

从邮政的大发展必须与高速发展的现代技术紧密结合的角度出发 ,论析了当前邮政部门对技术人才需求的迫切性 ,并提出了培养人才的若干举措。