In Vitro Lung Models and Their Application to Study SARS-CoV-2 Pathogenesis and Disease

SARS-CoV-2 has spread across the globe with an astonishing velocity and lethality that has put scientist and pharmaceutical companies worldwide on the spot to develop novel treatment options and reliable vaccination for billions of people. To combat its associated disease COVID-19 and potentially newly emerging coronaviruses, numerous pre-clinical cell culture techniques have progressively been used, which allow the study of SARS-CoV-2 pathogenesis, basic replication mechanisms, and drug efficiency in the most authentic context. Hence, this review was designed to summarize and discuss currently used in vitro and ex vivo cell culture systems and will illustrate how these systems will help us to face the challenges imposed by the current SARS-CoV-2 pandemic.     

Analysis of the In Situ Crack Evolution Behavior in a Solid Solution Mg-13Gd-5Y-3Zn-0.3Zr Alloy

The low plasticity of high strength Mg-Gd-Y alloy has become the main obstacle to its application in engineering. In this paper, the origin, propagation and fracture processes of cracks of a solution of treated Mg-13Gd-5Y-3Zn-0.3Zr alloy were observed and studied with scanning electron microscopy (SEM) in an in situ tensile test to provide theoretical references for the development of a new high-performance Mg-Gd-Y alloy. The results showed that there was still some bulk long period stacking order (LPSO) phase remaining in solid solution Mg-13Gd-5Y-3Zn-0.3Zr alloy. Most importantly, it was found that the locations of micro-cracks vary with the different solution treatment processes, mainly including the following three types. (1) At 480 × 10 h and 510 °C × 10 h, much bulk LPSO phase with higher elastic modulus remains in the alloy, which can lead to micro-cracks in the LPSO phase due to stress concentration. (2) At 510 °C × 13 h and 510 °C × 16 h, the phase structure of bulk LPSO changes, and the stress concentration easily appears at the LPSO/α-Mg interface, which leads to micro-cracks at the interface. (3) At 510 °C × 19 h and 510 °C × 22 h, the grain size increases, and the stress concentration is obvious at the grain boundary of coarse grains, which leads to the formation of micro-cracks.     

Interface Strength,Damage and Fracture between Ceramic Films and Metallic Substrates

Interface strength, damage and fracture properties between ceramic films and metallic substrates affect the service reliability of related parts. The films’ thickness, grain size and residual stress affect the interface properties and fracture behavior, thus related studies attract great attention. In this paper, the interface damage evolution and fracture behavior between ceramic films and metallic substrates were simulated by developing a three dimensional finite element model of alumina films on Ni substrates with cohesive elements in the interfaces. The interface fracture energy as a key parameter in the simulation was firstly determined based on its thermodynamic definition. The simulation results show the Mises stress distribution and damage evolution of the film/substrate structures during uniaxial tensile loading. Specially, when grain size of the films is in nanoscale, the interface strength increases obviously, agreeing with the previous experimental results. The effects of residual stress on interface properties was further simulated. The interface strength was found to decrease with increasing radial residual force and the axial residual pressure increases the interface strength. When the thickness of the films increases, the interface strength keeps a constant but the speed of interface damage becomes faster, that is, the thicker films show catastrophic fracture. The underlying mechanism of damage speed was analyzed. Understanding these size effects and the effects of residual stress is helpful to guide the design of related parts.     

Design and Evaluation of a New Resin-Filled GFRP Pipe Connection System for Butt Splicing of FRP Bars

Fiber-reinforced polymer (FRP) bars are one of the promising alternatives for steel bars used in concrete structures under corrosion or non-magnetic environments due to the unique physical properties of FRP materials. When compared with steel bars, FRP bars are difficult to be spliced in field application due to their anisotropy and low shear and compressive strengths. In view of this, the paper presents a new non-metallic connection system (i.e., resin-filled glass fiber-reinforced polymer (GFRP) pipe connection system) for the butt splicing of FRP bars. With the proposed connection system and a simplified trilinear interfacial bond-slip model, a set of design formulas were derived based on the requirement that the proposed connection system should provide a load transfer capacity beyond the tensile capacity of the spliced FRP bars (i.e., to fulfill the high tensile strength of FRP materials). Besides, considering the fabrication error-induced load transfer capacity reduction of the connection system in field application, a correction factor was introduced in the paper to compensate for the reduced load transfer capacity by increasing the FRP bar anchorage length. At last, to estimate the effectiveness of the proposed connection system and the derived design formulas, nine specimens were fabricated with a kind of commercially available basalt fiber-reinforced polymer (BFRP) bars and the designed connection system and tested under unidirectional tension to study their tensile performance. With the comparison between the tested and theoretical results, the effectiveness of the proposed connection system and the derived design formulas are verified.     

Influence of Old Concrete Age,Interface Roughness and Freeze-Thawing Attack on New-to-Old Concrete Structure

The bonding surface structure generated by the repair of concrete structures has been paid more attention as a weak point. The effects of old concrete age, interface roughness, and freeze-thawing (F-T) attack on adhesive interface are comprehensively investigated. In this study, six kinds of interface roughness and five different old concrete age are designed. The interfacial bonding property is mainly evaluated by splitting tensile strength (f_ts). Fractal analysis was used to characterize the interface roughness using laser scanning data. In general, the f_ts increased with the increasing value of interface fractal dimension. The relationship between f_ts and fractal dimension value was further analyzed, considering the old concrete ages and the F-T cycles. The results show that the effect of roughness on the bonding property of new-to-old concrete is more significant than the age of old concrete, and the influence of the F-T cycles on the bonding surface is mainly reflected in the initial stage of the F-T deterioration process. The relative dynamic elasticity modulus decreased obviously under F-T cycles, especially for the specimens with low interface roughness. In combination with the results of two non-destructive methods (ultrasonic non-destructive test and relative dynamic elastic modulus test), the larger roughness and the smaller age of old concrete can improve the bond performance.     

Green Nanocoatings Based on the Deposition of Zirconium Oxide: The Role of the Substrate

Herein, the influence of the substrate in the formation of zirconium oxide monolayer, from an aqueous hexafluorozirconic acid solution, by chemical conversion and by electro-assisted deposition, has been approached. The nanoscale dimensions of the ZrO₂ film is affected by the substrate nature and roughness. This study evidenced that the mechanism of Zr-EAD is dependent on the potential applied and on the substrate composition, whereas conversion coating is uniquely dependent on the adsorption reaction time. The zirconium oxide based nanofilms were more homogenous in AA2024 substrates if compared to pure Al grade (AA1100). It was justified by the high content of Cu alloying element present in the grain boundaries of the latter. Such intermetallic active sites favor the obtaining of ZrO₂ films, as demonstrated by XPS and AFM results. From a mechanistic point of view, the electrochemical reactions take place simultaneously with the conventional chemical conversion process driven by ions diffusion. Such findings will bring new perspectives for the generation of controlled oxide coatings in modified electrodes used, as for example, in the construction of battery cells; in automotive and in aerospace industries, to replace micrometric layers of zinc phosphate by light-weight zirconium oxide nanometric ones. This study is particularly addressed for the reduction of industrial waste by applying green bath solutions without the need of auxiliary compounds and using lightweight ceramic materials.     

Molecular design opportunities presented by solvent-exposed regions of target proteins

Solvent-exposed regions, or solvent-filled pockets, within or adjacent to the ligand-binding sites of drug-target proteins provide opportunities for substantial modifications of existing small-molecular drug molecules without serious loss of activity. In this review, we present recent selected examples of exploitation of solvent-exposed regions of proteins in drug design and development from the recent medicinal-chemistry literature.     

综合医院自助挂号机用户界面设计

目的：探讨综合性医院自助挂号设备的用户界面的设计方法。方法：通过对医院自助挂号设备的用户界面的现状进行分析,综合计算机科学、心理学和人机工程学的知识,以用户为导向,对自助挂号设备的用户界面进行合理设计。结果：设计了交互性强的自助挂号界面,降低了用户的操作难度,提高了挂号速度,适应不同年龄段和文化层次的人群。结论：以用户为导向的自助挂号界面的设计能够满足患者自助挂号的操作需求。     

体检管理系统与医院信息系统接口平台建设

结合医院信息化建设的特点,建立以HIS系统接口为核心的体检管理系统与医院其他系统的接口平台,实现医院各主要信息系统间无缝连接、数据交换与共享,提高体检的工作效率。     

Characterization of the Partition Rate of Ibuprofen Across the Water-Octanol Interface and the Influence of Common Pharmaceutical Excipients

This work reports the measurement of the partition rate of a model drug, ibuprofen (IBU), from aqueous solutions into octanol in the absence and presence of common pharmaceutical excipients including glucose, lactose, maltoheptaose, hydroxypropyl methylcellulose, polyvinylpyrrolidone, polyvinylpyrrolidone–vinyl acetate, hydroxypropyl methylcellulose AS, sodium dodecyl sulfate, Tween 80, and sodium taurocholate at varying concentrations. This attempts to assess the kinetic aspect of IBU partitioning across the water-octanol interface by applying a mechanistic model and to characterize the interfacial resistance. A significant reduction in P_i across the water-octanol interface was observed with extremely low concentration of the selected excipients in the aqueous media. These results reveal the presence of a surface excess of adsorbed excipients at the water-octanol interface. The retardation of the P_i of IBU was found to be sensitive to (1) the molecular weight or the degree of polymerization of these excipients, (2) the hydrodynamic condition of the experimental method, and (3) the pH of the aqueous media. Retardation of the P_i of IBU in the presence of excipients observed in this study is proposed by a steric obstruction mechanism through the adsorbed surface excess layer of excipients located at the water-octanol interface.