Materials and Wireless Microfluidic Systems for Electronics Capable of Chemical Dissolution on Demand

Electronics that are capable of destroying themselves, on demand and in a harmless way, might provide the ultimate form of data security. This paper presents materials and device architectures for triggered destruction of conventional microelectronic systems by means of microfluidic chemical etching of the constituent materials, including silicon, silicon dioxide, and metals (e.g., aluminum). Demonstrations in an array of home‐built metal‐oxide‐semiconductor field‐effect transistors that exploit ultrathin sheets of monocrystalline silicon and in radio‐frequency identification devices illustrate the utility of the approaches.     

三角褐指藻源岩藻黄素功能活性及其生物合成研究进展

海洋硅藻三角褐指藻(Phaeodactylum tricornutum)含有丰富的岩藻黄素且生长速度快,被认为是生产岩藻黄素的最佳物种之一。其中岩藻黄素作为一种天然类胡萝卜素,具有抗肿瘤、抗氧化、抗糖尿病、抗炎症、抗肥胖等生理活性,在生物医药和功能食品领域具有重要应用价值。岩藻黄素因合成机制的复杂性而表现出一定的不稳定性,使其在生产中存在着产量低、成本高等问题。本文详细介绍了三角褐指藻源岩藻黄素的功能活性,对岩藻黄素的合成机制及合成过程中不同因素对其积累量的影响因素的研究进展进行系统综述旨在深入研究海洋微藻来源的岩藻黄素的作用价值,为岩藻黄素进一步的开发利用提供技术支撑,有望为功能性食品领域的开发提供理论依据,为未来海洋硅藻产业化发展提供参考。     

State of the Art: The Immunomodulatory Role of MSCs for Osteoarthritis

Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA.     

智能化机动车综合性能检测系统的设计与开发

针对以单片机为核心开发的原机动车综合性能检测仪所存在的数据处理能力弱、功能不易扩充等缺点,基于上位机与下位机结构提出了一套智能化机动车综合性能检测系统设计方案.给出了系统结构及工作原理,介绍了系统组成中的关键硬件技术,并对软件系统编程进行了详细的论述,提出了机动车综合性能检测系统的全面解决方案.该方案可以解决原测试仪系统中存在的测试精度低、编程复杂、用户界面不够友好等一系列问题.     

Qualitative and quantitative identification of adulteration of milk powder using DNA extracted with a novel method

The extraction of high-quality DNA from processed dairy products is often the crucial step in an authentication process by PCR-based methods. In this study, we optimized a novel DNA extraction method for milk powder and used the extracted DNA for identification of milk powder based on PCR analysis. The DNA quality was assessed by amplifying target sequences from mitochondrial genes, as well as by monitoring the yield, purity, and integrity of the extracted DNA. In addition, a laboratory adulteration model of milk powder was detected by PCR-based methods (PCR and real-time PCR) using primers targeting the mitochondrial 12S rRNA gene. Results showed that a sufficient amount and quality of DNA could be isolated from milk powder with this method. Both PCR and real-time PCR detection of cow milk compositions in goat milk powder further confirmed the DNA extracted with this extraction method could be widely used in addressing milk powder adulterant by a PCR-based method.     

DNA‐Scaffolded Multivalent Ligands to Modulate Cell Function

We report a simple, versatile, multivalent ligand system that is capable of specifically and efficiently modulating cell‐surface receptor clustering and function. The multivalent ligand is made of a polymeric DNA scaffold decorated with biorecognition ligands (i.e., antibodies) to interrogate and modulate cell receptor signaling and function. Using CD20 clustering‐mediated apoptosis in B‐cell cancer cells as a model system, we demonstrated that our multivalent ligand is significantly more effective at inducing apoptosis of target cancer cells than its monovalent counterpart. This multivalent DNA material approach represents a new chemical biology tool to interrogate cell receptor signaling and functions and to potentially manipulate such functions for the development of therapeutics.     

Strong adsorption of phosphate by amorphous zirconium oxide nanoparticles

Phosphate removal is important in the control of eutrophication of water bodies. Adsorption is one of the promising approaches for the removal of phosphate, which could serve as a supplement for the biological phosphate removal process commonly used in the wastewater treatment industry to meet the discharge requirement when the biological performance is deteriorated from changes of operation conditions. Amorphous zirconium oxide nanoparticles were synthesized by a simple and low-cost hydrothermal process, and their phosphate removal performance was explored in aqueous environment under various conditions. A fast adsorption of phosphate was observed in the kinetics study, and their adsorption capacity was determined at about 99.01 mg/g at pH 6.2 in the equilibrium adsorption isotherm study. Commonly coexisting anions showed no or minimum effect on their phosphate adsorption performance. The phosphate adsorption showed little pH dependence in the range from pH 2 to 6, while it decreased sharply with the pH increase above pH 7. After adsorption, phosphate on these am-ZrO₂ nanoparticles could be easily desorbed by NaOH solution washing. Both the macroscopic and microscopic techniques demonstrated that the phosphate adsorption mechanism of am-ZrO₂ nanoparticles followed the inner-sphere complexing mechanism, and the surface hydroxyl groups played a key role in the phosphate adsorption.     

晶体管镀金可伐(Fe-Ni-Co合金)引线腐蚀断裂原因的研究

基于模型分析,研究了镀金可伐引线在各种缺陷组合方式下的偶合系统在静、动态3％NaCl溶液中的腐蚀行为。应用OCC理论阐述了蚀孔的形成和形貌特征。大气环境下镀金可伐引线的腐蚀是以偶合腐蚀为起因,具有闭塞小孔腐蚀特征的局部腐蚀。中性介质的实验结果与实际断腿样品在形貌等各方面均十分相符,这支持了上述观点。     

Comparison of tribological characteristics between aluminum alloys and polytetrafluoroethylene composites journal bearings under mineral oil lubrication

This study examined the tribological behavior of journal bearings made from polytetrafluoroethylene (PTFE) composites and aluminum (Al) alloys. The PTFE composite journal bearings consisted of a steel backing with a thickness of 1.6 mm, a middle layer of sintered porous bronze with a thickness of 0.24～0.27 mm, and a surface layer of PTFE filled with fluorinated ethylene propylene (FEP) powder and carbon fibers with a thickness 0.06～0.14 mm. The other was an aluminum alloy journal bearing consisted of a steel backing with a thickness of 1.5 mm and a surface layer of an Al-6Sn-6Si alloy with a thickness 0.35～0.75 mm. A series of lubrication tests were performed using a journal bearing tester under various normal loads. The tribological properties for each journal bearing were evaluated by measuring the lubricant oil temperature and friction coefficient as a function of the applied normal load. In addition, the chemical compositions and microstructures of the journal bearing materials used in this study was analyzed by inductively coupled plasma (ICP), optical microscopy (OM), and scanning electron microscopy (SEM), respectively. The experimental results showed that the Al alloy journal bearings reduce the friction coefficient by 28 % compared to the PTFE composites bearings. In addition, the Al alloy journal bearing worked properly at the maximum load of ～ 8,000 N without adhesion. However, the PTFE composite journal bearings exhibited strong adhesion at the loads ranging from 6300 to 8000 N. This suggests that the Al alloy is a more promising material in journal bearings than PTFE composites.