Transport phenomena with reactions in drug delivery: Towards a quantitative description

A distributed system called a Krogh cylinder is used here to quantify the transport of a solute from the capillary into the extravascular tissue. The capillary network is broken down into cylindrical cells, each containing a capillary and an appropriate amount of extravascular tissue. The flow in the cylinder model has two-dimensional velocities, which are in the axial and radial directions. All parameters of the system, together with the geometric ones, have been included in the model. For a given bioavailability, the uptakes of reactive and nonreactive solutes have been obtained. Very large or massive molecules have been considered. The diffusion in the tissue is found to be very low. Most of the drug uptake happens through convection, which is slowed down in the presence of a reaction. Further, this convection is entirely due to the flow out into the lymphatic system. For the case where a reaction takes place, local equilibrium is assumed, which both cuts down the computation times and provides good results in the case of reactive solutes. The full results of a distributed system have been obtained for the first time, and the mechanics of how the area-under-the-curve can be used to calculate the actual solute uptake have been determined.     

Electron Transport in Polymer-Derived Amorphous Silicon Oxycarbonitride Ceramics

The electron transport behavior of polymer-derived amorphous silicon oxycarbonitride ceramics is studied by measuring their temperature-dependent electrical conductivities. The experimental results are analyzed using theoretical models. The results reveal that the materials exhibit three conduction mechanisms: conduction in extended states, conduction in band tails, and conduction in localized states. Particularly, it is found that in a low-temperature regime, the conduction of the materials follows a band tail hopping mechanism, rather than the previously assumed variable range hopping mechanism. The results also reveal that energy gaps such as E _C− E _F and E _C− E _A decrease with increasing pyrolysis temperature.     

Electron Transport Mediated by Peptides Immobilized on Surfaces

Electron transfer reactions in proteins and peptides are crucial for biological energy conversion. Therefore, an important goal of fundamental research is to provide scientific insight into the mechanisms determining the bridge-mediated electron transport. One of the main tasks is to understand how the efficiency of this process is affected by the particular structure of a peptide, as well as the surrounding environment, and eventually, how we can control it by means of external chemical and physical factors. The latter could be of crucial importance for the design and development of biosensors and other functional devices, which may benefit from the unique electron transfer properties of peptides. Monolayers immobilized on solid surfaces seem to be particularly useful for that purpose. In this paper, we present the progress of fundamental research related to electron transport through peptides adsorbed onto metal surfaces. Specifically, we have focused on electrochemical studies and nanoscale molecular junction approaches. We have critically reviewed existing data and discussed the discrepancies in the measured efficiencies of electron transport. Some suggestions for future fundamental research in this area are provided. In particular, the need to combine the electrochemical and molecular junction approaches to explore the conductance behavior of peptides under full electrochemical control is emphasized. Some potential applications of peptide monolayers, which take advantage of the unique electrical properties of these compounds, are also discussed.     

Ligand Induced CuII Transport Restricts Cancer and Mycobacterial Growth: Towards a Plug-and-Select Ion Channel Scaffold

Synthetic channels with high ion selectivity are attractive drug targets for diseases involving ion dysregulation. Achieving selective transport of divalent ions is highly challenging due their high hydration energies. A small tripeptide amphiphilic scaffold installed with a pybox ligand selectively transports Cu^II ions across membranes. The peptide forms stable dimeric pores in the membrane and transports ions by a Cu²⁺/H⁺ antiport mechanism. The ligand-induced excellent Cu^II selectivity as well as high membrane permeability of the peptide is exploited to promote cancer cell death. The peptide's ability to restrict mycobacterial growth serves as seeds to evolve antibacterial strategies centred on selectively modulating ion homeostasis in pathogens. This simple peptide can potentially function as a universal, yet versatile, scaffold wherein the ion selectivity can be precisely controlled by modifying the ligand at the C terminus.     

邻位取代苝酰亚胺衍生物的合成及其电子迁移率的研究

以N,N'-二(3-戊胺)苝酰亚胺为底物,分别经过Ir催化剂直接催化邻位C—H的硼酸酯化和取代反应得到了2,5,8,11位含氯和含溴的苝酰亚胺衍生物Ⅲ和Ⅳ,利用1HNMR、13CNMR和HRMS对产物进行了表征。通过在苝酰亚胺的邻位引入卤原子后,相对于化合物Ⅰ,化合物Ⅲ和Ⅳ吸收光谱和荧光光谱均发生了蓝移;LUMO能级明显降低,分别为-4.18 eV和-4.16 eV。邻位引入卤原子后化合物Ⅲ和Ⅳ仍然具有良好的热稳定性,其失重5%时的温度(T d)均大于370℃。利用空间电荷限制电流(SCLC)法测试了它们的电子迁移率,发现卤原子的引入使分子间排列更加有序,其中化合物Ⅲ的迁移率最高,可以达到3.05×10-4cm2·V-1·s-1。     

邻位取代苝酰亚胺衍生物的合成及其电子迁移率

以N,N'-二(3-戊胺)苝酰亚胺为底物,分别经过Ir催化剂直接催化邻位C—H的硼酸酯化和取代反应得到了2,5,8,11位含氯和含溴的苝酰亚胺衍生物Ⅲ和Ⅳ,利用1HNMR、13CNMR和HRMS对产物进行了表征。通过在苝酰亚胺的邻位引入卤原子后,相对于化合物Ⅰ,化合物Ⅲ和Ⅳ吸收光谱和荧光光谱均发生了蓝移;LUMO能级明显降低,分别为-4.18 eV和-4.16 eV。邻位引入卤原子后化合物Ⅲ和Ⅳ仍然具有良好的热稳定性,其失重5%时的温度(T d)均大于370℃。利用空间电荷限制电流(SCLC)法测试了它们的电子迁移率,发现卤原子的引入使分子间排列更加有序,其中化合物Ⅲ的迁移率最高,可以达到3.05×10-4cm2·V-1·s-1。     

外给电子体Donor-D在聚丙烯装置上的应用

将新型高效外给电子体Donor-D在三井油化聚丙烯(PP)装置上进行应用考核,考察了该催化剂的适应性及产品质量情况。实验表明,Donor-D催化剂与DDS相比有其独特性,可以在聚丙烯工艺上进行推广。     

Specific Features of Ion–Electron Transport in Surface Oxide Films with Moving Boundaries

Ion–electron transport in a surface oxide film with moving boundaries, which is coupled with an electrode reaction of cation migration into a solution, is theoretically studied using a phenomenological approach. Analytical expressions are derived for the electric potential distribution and the concentrations of charged particles in the oxide, and also for the current–voltage characteristics of the system under consideration. It is shown that there is autocatalytic acceleration of the electrochemical process due to the displacement of the interfaces. It was concluded that the potential jump at the film–solution interface can change sign at sufficiently high current densities.     

Towards a Systematic Data Harmonization to Enable AI Application in the Process Industry

Current methods of artificial intelligence may often proof ineffective in the process industry, usually because of insufficient data availability. In this contribution, we investigate how data standards can contribute to fulfill the data availability requirements of machine learning methods. We give an overview of AI use cases relevant in the process industry, name related requirements and discuss known standards in the context of implicit vs. explicit data. We conclude with a roadmap sketching how to bring the results of this contribution into practical application.     

电子束辐照技术在环境保护中的应用

电子束辐照降解技术作为辐照技术的一个分支,近年来获得了快速发展,在环境保护中的应用日益广泛。概述了电子束辐照降解技术在处理废气、废水以及固体废弃物等方面的研究应用,指出了环境保护中电子束辐照技术所存在的问题,并展望了其应用前景。     

EWB在《模拟电子技术基础》课程教学中的应用

本文根据作者的教学实践,介绍了在《模拟电子技术基础》课程教学中应用EWB(虚拟电子工作台)进行模拟实验的方法和一些实例。通过这些例子,可以看到EWB在《模拟电子技术基础》课程教学中的广阔前景,其方便的更改电路和元件参数的能力,使其得以很好的了解电子电路的各种性质。     

电子束辐照预硫化技术在轮胎轻量化中的应用

研究电子束辐照预硫化技术在轮胎轻量化中的应用。采用经过电子束辐照预硫化的胎体,可以减薄、减窄过渡层,从而减小轮胎质量,降低生产成本,并且轮胎不会出现胎里露线现象,同时不会影响成品轮胎的充气外缘尺寸、高速性能和耐久性能。     

Liquid Transport in a Coalescing Froth

A previous study (Ireland and Jameson, J. Colloid Interface Sci., 314 207‐213 (2007)) demonstrated that a “drift‐flux” model could describe liquid transport in a stable rising froth with added “wash water.” In the present study, a drift‐flux model was used to describe a rising coalescing froth. This model incorporated the effect of liquid released into the froth by coalescence. Vertical profiles of liquid fraction and bubble size were obtained in a laboratory cell; a novel technique was used for measuring bubbles deep within the cell. These data were consistent with the predictions of the drift‐flux model.     

Transport in a hollow cylindrical membrane

A detailed treatment has been given of radial transport in and through a hollow cylindrical membrane for two initial distributions of diffusant within the membrane of practical interest. Expressions are given for concentration distributions of diffusant and for unit length of membrane, amounts present, fluxes through radial planes, and amounts transported up to time t across those planes. Some consideration has been given to forward and reverse flow and to relations between flow quantities characteristic of those transports. © 1997 John Wiley & Sons, Inc.     

扫描电镜法在检验纸张中的应用研究

对书写类纸张的检验是日常文件检验中的一项重要技术手段,在纸张检验的过程中,有时有必要对书写类纸张的种属类型进行检验,并对疑似同种或同一张纸进行整体及部分的检验。主要研究的是扫描电镜法对书写类纸张的检验,希望可以为纸张检验提供理论支持。     

Application of Transmission Electron Microscopy to Radiation Damage in Ceramics

Ceramics are becoming increasingly important in many radiation environments. In addition to refractory fissionable fuels, electrical insulators will be needed for instrumentation in breeder reactor systems and will be widely applied in all fusion reactor concepts, including first-wall coatings, blanket gaps, injectors, divertors, magnet insulation, and windows. These applications require mechanically stable (and in some cases transparent) dielectric solids which must maintain electrical as well as mechanical integrity under severe radiation fields. Refractory ceramic materials of low atomic number will be increasingly useful in structural applications as well because they resist activation and contribute less objectionable sputter contaminants. Ceramic solids are also likely to be increasingly utilized as repository media for active nuclear wastes. The irradiation behavior of these nonmetallic materials is critical and at present poorly understood, but transmission electron microscopy is beginning to reveal significant similarities, as well as substantial differences, in their behavior as compared to that of better-characterized metallic solids.     

无机空穴传输材料在钙钛矿太阳能电池中的应用

钙钛矿太阳能电池具有光电转换效率高、结构简单、成本低廉、有大规模商业化应用潜力等优势,是近年来光伏领域的研究热点。空穴传输材料具有传输空穴和阻挡电子的双重作用,是影响钙钛矿太阳能电池光电性能的重要因素。本文介绍了空穴传输材料的作用方式和主要类别,总结了无机空穴传输材料的种类、特点及在钙钛矿太阳能电池中的应用,并分析了其对太阳能电池光电性能的影响。     

浓相气力输送在PTA输送系统上的应用

介绍浓相气力输送的技术原理、工作过程、系统的自动控制及在PTA粉料输送上的应用。     

90万t焦炉输煤PLC控制系统的开发及应用

论述了90万t焦炉输煤PLC控制系统的硬件组成、软件开发过程及开发调试过程中的经验教训，并对计算机配煤控制系统作了扼要介绍。