Numerical investigation on electron effects in the mass transfer of the plasma species in aqueous solution

The objective of this work is to contribute an understanding of the effects of electrons in the plasmas on the mass transfer of plasma species in aqueous solution by means of the numerical simulation based on a one-dimensional diffusion-reaction model. The plasma species are divided into two groups, i.e. electrons and the other species, and the mass transfer in the three scenarios has been simulated, including the systematic calculations of the depth distributions of five major reactive species, OH, O₃, HO₂ , O₂^-, and H₂O₂ . In the three scenarios, the particles considered to enter into aqueous solution are all the plasma species (the scenario I, where the mass transfer of plasma species is a result due to the synergy of the electrons and the other plasma species), the other species (the scenario II), and only electrons in plasma species (the scenario III), respectively. The detailed analyses on the difference between the depth distributions of each reactive species in these three scenarios show the following conclusions. The electrons play an important role in the mass transfer of plasma species in aqueous solution and the synergy of the electrons and the other plasma species (the electron-species synergy) presents its different effects on the mass transfer. The vast majority of H₂O₂ are generated from a series of the electron- related reactions in aqueous solution, which is hardly affected by the electron-species synergy. Compared to the results when only the electrons enter into the liquid region, the electron-species synergy evidently weakens the generation of O₂^-, O₃ , and OH, but promotes to produce HO₂ .     

Influence of Natural Crosslinkers on Chitosan Hydrogels for Potential Biomedical Applications

Chitosan (CH) is a very well-known biopolymer that has been widely used for the development of biomaterials with a wide range of applications in the biomedical field, such as the preparation of hydrogels, owing to its outstanding anti-inflammatory, antibacterial and antifungal properties, biocompatibility and biodegradability, although they present limited mechanical properties. Chemical crosslinking is one of the most recurrent strategies for the reinforcement of these structures and, above all, crosslinking with natural-origin compounds that do not compromise their biocompatibility is considered a hot topic in this research field. D-fructose (F), obtained from the hydrolyzation and further isomerization of starch, an abundant raw material and genipin (G), which is extracted from the fruits of Gardenia jasminoides Ellis are used as natural crosslinkers. Chitosan-based hydrogels crosslinked with each crosslinking agent are prepared and characterized through Fourier transform infrared (FTIR) spectroscopy, crosslinking and swelling degree determination, rheological, microstructural, and biological studies. The results demonstrate that crosslinking with G is more beneficial for chitosan-based hydrogels since these samples showed more compact structures and better rheological performance. Additionally, excellent biological in vitro behavior due to the crosslinking with G, unlike that of F.     

Recent Progress and Perspectives of Thermally Drawn Multimaterial Fiber Electronics

Fibers are the building blocks of a broad spectrum of products from textiles to composites, and waveguides to wound dressings. While ubiquitous, the capabilities of fibers have not rapidly increased compared to semiconductor chip technology, for example. Recognizing that fibers lack the composition, geometry, and feature sizes for more functions, exploration of the boundaries of fiber functionality began some years ago. The approach focuses on a particular form of fiber production, thermal-drawing from a preform. This process has been used for producing single material fibers, but by combining metals, insulators, and semiconductors all within a single strand of fiber, an entire world of functionality in fibers has emerged. Fibers with optical, electrical, acoustic, or optoelectronic functionalities can be produced at scale from relatively easy-to-assemble macroscopic preforms. Two significant opportunities now present themselves. First, can one expect that fiber functions escalate in a predictable manner, creating the context for a “Moore's Law” analog in fibers? Second, as fabrics occupy an enormous surface around the body, could fabrics offer a valuable service to augment the human body? Toward answering these questions, the materials, performance, and limitations of thermally drawn fibers in different electronic applications are detailed and their potential in new fields is envisioned.     

25th Anniversary Article: Galvanic Replacement: A Simple and Versatile Route to Hollow Nanostructures with Tunable and Well‐Controlled Properties

This article provides a progress report on the use of galvanic replacement for generating complex hollow nanostructures with tunable and well‐controlled properties. We begin with a brief account of the mechanistic understanding of galvanic replacement, specifically focused on its ability to engineer the properties of metal nanostructures in terms of size, composition, structure, shape, and morphology. We then discuss a number of important concepts involved in galvanic replacement, including the facet selectivity involved in the dissolution and deposition of metals, the impacts of alloying and dealloying on the structure and morphology of the final products, and methods for promoting or preventing a galvanic replacement reaction. We also illustrate how the capability of galvanic replacement can be enhanced to fabricate nanomaterials with complex structures and/or compositions by coupling with other processes such as co‐reduction and the Kirkendall effect. Finally, we highlight the use of such novel metal nanostructures fabricated via galvanic replacement for applications ranging from catalysis to plasmonics and biomedical research, and conclude with remarks on prospective future directions.     

激光诱导空泡在生物医学中的应用

激光诱导空泡现象从20世纪中期被发现之后,就受到了广泛的关注,而近年来研究热点之一的微流控技术,由于在物理尺寸上与激光诱导空泡尺度匹配,近年来研究人员已经将这两个技术融合在一起应用于生物医学领域。通过细胞膜穿孔给细胞微注射药物、通过红细胞的形变量的大小来检测红细胞是否发生病变、通过荧光标记技术来筛选细胞以及降低眼部虹膜切割手术带来的副作用等,综述了激光诱导空泡结合微流控生物芯片在生物医学中的应用,展望了激光诱导空泡现象在生物医学中应用的方向。     

纳米Fe3O4磁性颗粒表面改性及其在医学和环保领域的应用

纳米Fe₃O₄磁性材料在生物医学、环保、催化及电子信息等领域有巨大的应用潜力,但单独的纳米Fe₃O₄颗粒存在一些弊端,难以直接使用,在生物医药领域尤其如此。对Fe₃O₄磁性纳米粒子进行表面改性,可以改善其结构与性能,因此,备受科学界关注。对近年来Fe₃O₄磁性纳米颗粒的表面改性方法及其在生物医学、环境工程两大领域中的应用做了综述,并对今后发展趋势做了初步的展望。     

加速器质谱(AMS)测定~(41)Ca的方法研究

简要介绍应用加速器质谱计 (AMS)测量 4 1Ca,并与标准样品进行对照。4 1Ca测量结果表明 :4 1Ca的加速器质谱 (AMS)测量方法是可行的和可靠的 ,测量灵敏度已能够达到 1 0 -14 数量级     

羟基磷灰石纳米粒子表面修饰的研究进展

羟基磷灰石是人体骨骼和牙齿的主要无机成分,具有良好的生物相容性和生物活性,且能诱导骨组织的生长,促进组织缺损的修复,是性能优异的骨修复材料。近年来,纳米羟基磷灰石由于其独特的性能,在生物医学领域展现出新的应用功能。但是,为了发挥纳米羟基磷灰石独特的功能特性,常常需要对其进行表面修饰,以满足生物医学应用的条件和要求。从生物医学角度,针对羟基磷灰石纳米粒子在生物显影、DNA转染、药物递送、与高分子复合、促进成骨和抑菌等方面的应用,对羟基磷灰石纳米粒子的表面修饰研究进行论述,探讨相关表面修饰思路和技术及修饰应用效果。通过表面修饰,不仅可以提高羟基磷灰石纳米粒子的分散性和悬浮稳定性,提升药物装载能力和促进成骨能力,还可以赋予其生物显影能力、主动靶向功能和抑菌能力。总之,表面修饰是一种促进羟基磷灰石纳米粒子生物医学应用的有效手段。