Permeation Enhancers for Transdermal Drug Delivery

The transdermal route has been recognized as one of the highly potential routes of systemic drug delivery and provides the advantage of avoidance of the first-pass effect, ease of use and withdrawal (in case of side effects), and better patient compliance. However, the major limitation of this route is the difficulty of permeation of drug through the skin. Studies have been carried out to find safe and suitable permeation enhancers to promote the percutaneous absorption of a number of drugs. The present review includes the classification of permeation enhancers and their mechanism of action; thus, it will help in the selection of a suitable enhancer(s) for improving the transdermal permeation of poorly absorbed drugs.     

Comparison of gaseous contaminant diffusion under stratum ventilation and under displacement ventilation

The gaseous contaminant diffusion under stratum ventilation is investigated by numerical method which is validated by experiments carried out. The concentration of gaseous contaminants along the supply air jet is found to be lower than the other parts of the room. Compared with displacement ventilation, the formaldehyde concentration in breathing zone is lower when a contaminant source locates close to the occupant. The concentration is at the same level when the contaminant source locates up-steam to the occupant. The concentration in the occupied zone (<1.9 m from the floor) is also lower when the contaminant source locates on the floor. At supply air temperature optimized for displacement ventilation, the toluene concentration in breathing zone for stratum ventilation is higher than that for displacement ventilation when the area source locates on the four surrounding walls of the room.     

构造分析中具有非对称形态的地层褶皱模型

首次将双模量Ｗｉｎｋｌｅｒ地基引入构造分析中，提出了具有某一种蛎对称构造形态的地质褶皱模型。根据分区原理构造连续位移函数和δ跳跃函数，再用Ｌａｇｒａｎｇｅ乘子将交界面连续条件引入到分区变分原理泛函之中。问题的数学描述建立了近似计算的基础。结果表明，非对称形态的关键因子Ｌ受双模量地基反差系数α的控制数值计算显示，思路和方法是有效的。     

Evaluation of thermal comfort conditions in a classroom with three ventilation methods

Thermal sensation is studied experimentally under mixing ventilation, displacement ventilation, and stratum ventilation in an environmental chamber. Forty-eight subjects participated in all tests under the same boundary conditions but different ventilation methods in the classroom. Thermal comfort analysis was carried out according to the designated supply airflow rate, room temperature, and relative humidity for the three ventilation methods. The thermal neutral temperature under stratum ventilation is approximately 2.5 °C higher than that under mixing ventilation and 2.0 °C higher than that under displacement ventilation. This result indicates that stratum ventilation could provide satisfactory thermal comfort level to rooms of temperature up to 27 °C. The energy saving attributable to less ventilation load alone is around 12% compared with mixing ventilation and 9% compared with displacement ventilation. PRACTICAL IMPLICATIONS: The confirmation of the significantly elevated thermal neutral temperature can have a number of implications for both thermal comfort in an air-conditioned room and energy consumption of the associate air-conditioning system. With respect to the former, it provides scientific basis for the feasibility of elevated room temperatures, and with respect to the latter, it reveals considerable potentials for energy saving.     

Experimental and numerical study of room airflow under stratum ventilation

This paper investigates the air movement, air temperature profile and gaseous contaminant transportation in an individual office with stratum ventilation. The room temperature is elevated compared with conventional standards. The experimental investigation is carried out in an environmental chamber with the presence of heat generating rectangles used to simulate an occupant and a computer. Measurements of temperature, velocity, and CO₂ concentration are carried out for nine plumb lines in the chamber. Up to sixteen points are measured along each plumb line. The experimental data of the aforesaid three parameters of the individual office in warm condition under stratum ventilation are presented. The experimental data collected are used to validate a re-normalization group (RNG) k–? turbulence model used for the warm condition. The agreements between the predicted values and experimental results are acceptable, which demonstrates the feasibility of simulating indoor airflows at elevated room temperature under stratum ventilation by the RNG k–? turbulence model.     

Comparison of annual energy performances with different ventilation methods for cooling

Stratum ventilation has been proposed to cope for elevated indoor temperatures recommended by governments in East Asia. TRNSYS is used for computation of the space cooling load and system energy consumption. Typical configurations of an office, a classroom and a retail shop in Hong Kong are investigated. Compared with mixing ventilation and displacement ventilation, stratum ventilation derives its energy saving potential largely from the following three factors: the reduction in ventilation and transmission loads and increased COP of chillers. The year-round energy saving is found to be substantial at 25% and 44% at least when compared with displacement ventilation and mixing ventilation, respectively.     

浅部岩层冒顶隐患级别的数值模拟研究

 为了找出浅部岩层类型与巷道顶板冒顶隐患级别了关系,采用RFPA软件,模拟不同类型岩层条件下的顶板岩层变形破坏特征。结果表明,浅部岩层的强度指标决定了巷道破坏范围,直接影响到巷道冒顶隐患级别,冒顶风险按照软-韧型、软-脆型、中硬-韧型、中等强度-中等刚度型、硬-韧型、硬-脆型岩层的次序降低;岩层刚度决定了顶板岩层的破坏形态,对冒顶隐患级别的影响权重小于岩石强度;浅部岩层为硬-韧、硬-脆型顶板采用单一的锚杆支护即可保证巷道不发生冒顶事故。     

地层储能技术及其在煤矿上的应用分析

根据近年来第三代地热工程技术和地源热泵技术的发展,综合传统浅部地热能利用技术和中国矿业大学(北京)何满潮提出的深部地层储能技术,提出地层储能技术的内涵,介绍了其工艺系统的基本原理。结合煤矿的特点提出煤矿上可采用的储能系统的三种储能模型,采用传热学基本原理对模型进行数学分析,并结合工程分析了其在煤矿上的应用。     

Synthesis of new antioxidant conjugates and their in vitro hydrolysis with Stratum corneum enzymes

The aim of this study was to synthesize new precursors, combinations of well-known antioxidant molecules: resveratrol, lipoic acid and vitamin E to improve their photo-stability and to modulate their lipophylic character. Active antioxidants are available through a controlled release by the action of skin enzymes upon a topic application. Two conjugates are described, the combinations of resveratrol-lipoic acid (6) and resveratrol-vitamin E (10). Both compounds are new molecules. This work describes their synthesis, characterization, stability study and in vitro biohydrolysis. Stratum corneum enzymes efficiently hydrolysed in vitro precursor 6 and liberate both active molecules, resveratrol and lipoic acid over the period of 72 h. Precursor 10 was hydrolysed in vitro by combination of Stratum corneum enzymes and the cholesterol esterase. A simple technique of preparation of the human Stratum corneum hydrolases is also described.     

多类回归判别对柯克亚第三系地层的划分研究

本文采用多类回归判别方法对柯克亚地区地层微量元素进行回归判别分析,建立回归判别模式,以求找到一种较好解决"哑地层"划分对比的新方法.