Biodegradable Hydrophobic Injectable Polymers for Drug Delivery and Regenerative Medicine

Biodegradable, hydrophobic, and injectable liquid polymers are capable of achieving the minimally invasive, sustained, and local release of drugs. These hydrophobic injectable polymers also have potential in the area of regenerative medicine where the biomaterial should be stable for a certain period and then degrade to allow the growth of cells/tissues. This review presents exclusive coverage of biocompatible hydrophobic injectable pasty or liquid polymers that can be injected without the use of any solvent for drug delivery, tissue augmentation, and regenerative medicine application. The synthesis methodologies of several major types of hydrophobic pasty polymers used in the biomedical fields and their properties with the foremost criteria to serve as injectable biomaterial for localized drug delivery and regenerative medicine is described. The hydrophobic biodegradable injectable polymers discussed are aliphatic polyesters, polycarbonates and polyanhydrides, prepared from: lactic acid, glycolic acid, caprolactone, aliphatic diols and diacids, hydroxy fatty acids, and triglycerides such as castor oil.     

Advances in Triboelectric Nanogenerators for Self-Powered Regenerative Medicine

Over the last decade, in pursuit to provide suitable alternatives for power supplies of medical devices in regenerative medicine, extensive research on nanogenerators has been developed. Such devices can overcome current commercial battery challenges, including intense heat-on-body complications due to the electrical current during therapeutic usage, leading to protein denaturation, cell structure destruction, and even cell necrosis. In addition, these traditional batteries contain a bulky and heavy structure that prevents them from providing sustainable on body biomedical therapeutic intervention. Furthermore, advantages such as wide-range biocompatible and biodegradable materials, lightweight, and sufficient stretchability for device construction can minimize the side effects of implantable devices, including inflammation or toxicity, as well as eliminate secondary surgery to replace or remove batteries. Triboelectric nanogenerators (TENGs) are associated with harvesting mechanical energy in various forms, among which human body motions can serve as a renewable power source for healthcare systems. This review is written to emphasize the importance of TENG's applications in regenerative medicine and modulation purposes, particularly for the nervous system. Some crucial parameters for implantable consideration are discussed. In the concluding remarks, features for clinical utilization including output efficiency, encapsulation, stability, and miniaturization are suggested as challenges and prospects.     

卫星移动通信中星上再生处理技术的实现方法

本文在分析几种星上处理技术性能和发展的基础上，讨论了它们在卫星移动通信中的应用及实现方法，分析了再生转发器的性能。最后讨论了采用ＤＳＰ芯片实现ＤＱＰＳＫ数字调制信号再生处理的方案，给出了框图。     

The Implications of Polymer Selection in Regenerative Medicine: A Comparison of Amorphous and Semi‐Crystalline Polymer for Tissue Regeneration

Biodegradable polymeric scaffolds are being investigated as scaffolding materials for use in regenerative medicine. While the in vivo evaluation of various three‐dimensional (3D), porous, biodegradable polymeric scaffolds has been reported, most studies are ≤3 months in duration, which is typically prior to bulk polymer degradation, a critical event that may initiate an inflammatory response and inhibit tissue formation. Here, a 6 month in vitro degradation and corresponding in vivo studies that characterized scaffold changes during complete degradation of an amorphous, 3D poly(lactide‐co‐glycolide)(3D‐PLAGA) scaffold and near‐complete degradation of a semi‐crystalline3D‐PLAGA scaffold are reported. Using sintered microsphere matrix technology, constructs were fabricated in a tubular shape, with the longitudinal axis void and a median pore size that mimicked the architecture of native bone. Long‐term quantitative measurements of molecular weight, mechanical properties, and porosity provided a basis for theorization of the scaffold degradation process. Following implantation in a critical size ulnar defect model, histological analysis and quantitative microCT indicated early solubilization of the semi‐crystalline polymer created an acidic microenvironment that inhibited mineralized tissue formation. Thus, the use of amorphous over semi‐crystalline PLAGA materials is advocated for applications in regenerative medicine.     

Advanced Functional Biomaterials for Stem Cell Delivery in Regenerative Engineering and Medicine

Stem cell–based therapies can potentially regenerate many types of tissues and organs, thereby providing solutions to a variety of diseases and injuries. However, acute cell death, uncontrolled differentiation, and low functional engraftment yields remain critical obstacles for clinical translation. Advanced functional biomaterial scaffolds that can deliver stem cells to the targeted tissues/organs and promote stem cell survival, differentiation, and integration to host tissues may potentially transform the clinical outcome of stem cell–based regenerative therapies. In this review, the authors briefly summarize sources of stem cells for transplantation, present the current state of the art in biomaterial design for stem cell delivery, and provide critical analysis for existing materials. Applications to the cardiovascular, neural, and musculoskeletal systems are highlighted with recent nonclinical studies and clinical trials. The authors also discuss how advances in biomaterials research can contribute to regenerative medicine research and stem cell therapies.     

自由电子激光中相对论性电子束的电荷波和电流波

本文根据电子的运动方程和泊松方程描述相对论性电子束。在电子束无微扰时，空间电荷最低消的，因而可使方程线性化。线性化了的方程有指数函数波形式ｅｘｐ的解，由此得出了电子束电子电荷波和电子电流波。     

卤化铜激光器的发展与应用探索

十年来卤化铜激光器得到很大的进展,可以代替中小功率的纯铜器件,达到实用化程度。综述了我们的器件在非线性光学、激光光谱、激光物理、光学材料检验、信息储存、显微投影、亮度放大、高速摄影以及眼科治疗方面的应用。     

生态芯片及其在医学和生物学中的应用

本文阐述了生物芯片的制作原理及杂交信号的检测方法及其在生物医学中的应用。生物芯片的制作工艺主要分两大类：一类是采用在芯片点阵上直接合成寡核苷酸的方法;另一类是用点阵或喷墨打印法将纳升级的微量DNA溶液直接以阵列形式点放并固化在芯片载体上,生物芯片主要通过杂交信号进行检测。对于荧光标记的杂交信号的检测方法,主要有激光荧光扫描显微镜、激光扫描共焦显微镜、带有CCD相机的荧光显微镜、光纤生物传感器等。对于生物素标记的杂交信号的检测方法,主要有化学发光法、光激发磷光物质存储屏法。DNA基因芯片在生物医学中有着重大的应用前景。     

纯电动公交车再生制动系统研究和仿真

随着环保问题和能源问题的日益严重，电动汽车因其零排放、低噪声等优点受到了广泛的关注，世界各国都将新能源汽车作为汽车工业的发展方向。纯电动公交车的制动系统能在车辆下坡或减速的时候将一部分车辆的动能转化为电能存在超级电容中。本文研究的制动系统属于再生和液压共同组成的混合制动系统。     

In Situ Porous Structures: A Unique Polymer Erosion Mechanism in Biodegradable Dipeptide-based Polyphosphazene and Polyester Blends Producing Matrices for Regenerative Engineering

Synthetic biodegradable polymers serve as temporary substrates that accommodate cell infiltration and tissue in-growth in regenerative medicine. To allow tissue in-growth and nutrient transport, traditional three-dimensional (3D) scaffolds must be prefabricated with an interconnected porous structure. Here we demonstrated for the first time a unique polymer erosion process through which polymer matrices evolve from a solid coherent film to an assemblage of microspheres with an interconnected 3D porous structure. This polymer system was developed on the highly versatile platform of polyphosphazene-polyester blends. Co-substituting a polyphosphazene backbone with both hydrophilic glycylglycine dipeptide and hydrophobic 4-phenylphenoxy group generated a polymer with strong hydrogen bonding capacity. Rapid hydrolysis of the polyester component permitted the formation of 3D void space filled with self-assembled polyphosphazene spheres. Characterization of such self-assembled porous structures revealed macropores (10-100 μm) between spheres as well as micro- and nanopores on the sphere surface. A similar degradation pattern was confirmed in vivo using a rat subcutaneous implantation model. 12 weeks of implantation resulted in an interconnected porous structure with 82-87% porosity. Cell infiltration and collagen tissue in-growth between microspheres observed by histology confirmed the formation of an in situ 3D interconnected porous structure. It was determined that the in situ porous structure resulted from unique hydrogen bonding in the blend promoting a three-stage degradation mechanism. The robust tissue in-growth of this dynamic pore forming scaffold attests to the utility of this system as a new strategy in regenerative medicine for developing solid matrices that balance degradation with tissue formation.     

Biodegradable Photothermal and pH Responsive Calcium Carbonate@Phospholipid@Acetalated Dextran Hybrid Platform for Advancing Biomedical Applications

A biodegradable multifunctional carrier for combination therapy with high efficiency and low side effect is essential for effective cancer treatment and for advancing biomedical applications. Therapeutics combination could reduce multidrug resistance and minimize doses through synergism. This study develops biodegradable gold nanorods@calcium carbonate particles coated with pH‐responsive acetalated dextran and phospholipid as an advanced platform for the incorporation of versatile molecular targeted therapeutics, including hydrophilic and hydrophobic drugs, as well as the model enzyme, green fluorescent protein, or antibody. The developed calcium carbonate based hybrid particles show good biocompatibility, stability with photothermal, and pH responsiveness, which protect the payloads from premature release, and maintain the enzyme activity. The therapeutics co‐loaded CaCO₃ based hybrid particles efficiently induce cancer cell death and reduce the multidrug resistance and HER2 expression with synergism. The photothermal effects promote ultrafast therapeutics release and induce significant cytotoxicity. Importantly, Anti‐HER2 antibody or HER2 targeted therapeutic is more effective in reducing HER2 expression when combined with drug or drugs via synergism. Overall, the cheap and simply manufactured biodegradable hybrid platform has great potential for advancing biomedical applications, including targeted photothermal combination therapy by co‐delivery of different types of therapeutics, including molecular targeted drugs, antibodies, and enzymes.     

城市轨道交通再生制动逆变回馈装置研究

目前城市轨道交通中多采用车载制动电阻方式来吸收车辆制动产生的能量,这样不仅造成了能源的极大浪费,而且会导致隧道温升等一系列问题。本文研究了一种新型城市轨道交通车辆再生制动能量逆变回馈装置,将普通硅整流器与小容量PWM变换器相组合,采用电压外环,电流内环双环控制,分析了其数学模型并构建了系统的电流静态解耦控制器。仿真结果表明,该结构的逆变装置具有良好的制动能量回馈性能。     

Advances in Chemically Powered Micro/Nanorobots for Biological Applications: A Review

Micro/nanorobots (MNRs) are capable of autonomous motion, breaking through the limitations of traditional passive transport of nanocarriers. Among them, chemically driven MNRs are the earliest MNRs studied and have received extensive attention from researchers. This review first focuses on the material properties, preparation, driving forms, and mechanisms of chemically driven MNRs. The current status of research on chemically driven MNRs in biomedicine is summarized for various biological applications (drug delivery, diagnostics, anti-inflammatory, antibacterial, and disease treatment). In terms of biosafety, possible safety issues are analyzed in the context of chemically driven microrobotic applications in terms of three aspects: component characteristics, chemical engines and biological environment. Finally, the challenges and possible future directions of chemically driven MNRs are presented.     

Recent Advances in Applications of Sorted Single‐Walled Carbon Nanotubes

Single‐walled carbon nanotubes (SWCNTs) exhibit outstanding properties that make them appealing in a wide range of applications. However, their properties are variable depending on the tube helicity (chirality), which has been a challenge for a long time and needs to be effectively controlled. In recent years, tremendous efforts have been made to control the electrical type/chirality of nanotubes through both direct controlled synthesis and postsynthesis separation methods. Driven by these breakthroughs, the applications of separated families of SWCNTs in various fields have emerged as a new topic of research. In this Review, an overview of recent advances in the use of highly purified and well‐separated SWCNTs in a comprehensive range of applications is presented including photovoltaics, transistors, batteries, sensors, light emitters, biological/medical fields, and others. Finally, important future directions for the utilization of separated SWCNTs in these fields are provided.     

Recent Advances of Cell Membrane‐Coated Nanomaterials for Biomedical Applications

Surface modification of nanomaterials is essential for their biomedical applications owing to their passive immune clearance and damage to reticuloendothelial systems. Recently, a cell membrane‐coating technology has been proposed as an ideal approach to modify nanomaterials owing to its facile functionalized process and good biocompatibility for improving performances of synthetic nanomaterials. Here, recent advances of cell membrane‐coated nanomaterials are reviewed based on the main biological functions of the cell membrane in living cells. An overview of the cell membrane is introduced to understand its functions and potential applications. Then, the applications of cell membrane‐coated nanomaterials based on the functions of the cell membrane are summarized, including physical barrier with selective permeability and cellular communication via information transmission and reception processes. Finally, perspectives of biomedical applications and challenges about cell membrane‐coated nanomaterials are discussed.     

EMI/RFI热塑性导电弹性体的特点及应用

高导电性能的热塑性导电弹性体是一种防护电磁波干扰(EMI/RFI)的高分子功能复合材料,在电子/微电子工业中的电磁兼容(EMC)领域具有重要应用.介绍了热塑性导电弹性体的特点、分类和应用领域以及新型热塑性导电弹性体的研究进程和发展方向.     

光子学在交通运输中的应用

评述光子学在城市交通、公路运输、铁路运输、海上运输、空中运输和宇宙航行中的应用。     

LED光柱的条图在仪表行业的应用及问题

LED芯片作为一种新的光源，在国内开创了巨大的新兴市场，其应用越来越广。介绍了LED光柱显示器替代仪表指针的应用情况，结合其制作与应用进行了讨论。LED光柱自身发光，色彩丰富，并具有抗过载、抗振动、平均无故障工作时间在5万小时左右等特点，是仪表显示方式一个新的飞跃。     

光子学在休闲娱乐中的应用

评述光子学在摄影、显示、音像、影视、体育、音乐和艺术中的应用。     

SOI技术及其发展和应用

绝缘衬底上的硅(SOI)技术被誉为"21世纪的微电子技术"。它可消除或减轻体硅中的体效应、寄生效应及小尺寸效应等。该文对注氧隔离、键合再减薄、键合和注入相结合及外延层转移等SOI的几种主流制备技术进行了概述,着重介绍了SOI在抗辐照、耐高温等高性能专用电路、光电子、微机械方面以及三维集成电路等领域的主要应用,最后讨论了近几年来SOI技术研究和发展的新动向。