Supercritical-fluid chromatography: Open columns vs packed columns

Supercritical-fluid chromatography (SFC) may be performed either in open (capillary) columns or in packed columns. Both approaches have been demonstrated numerous times in the literature. In this contribution it will be attempted to discuss some aspects of columns for SFC. Some advantages of both types of columns will be identified. Attention is paid to the stationary phase film thickness, the speed of analysis, and to the maximum number of theoretical plates (effect of column pressure drop). In this brief contribution many questions will be left unanswered and many significant aspects will be left undiscussed, illustrating that much research remains to be done in this area.     

Nicotinamide adenine dinucleotide: beyond a redox coenzyme

ADP-ribosylation using nicotinamide adenine dinucleotide (NAD+) is an important type of enzymatic reaction that affects many biological processes. A brief introductory review is given here to various ADP-ribosyltransferases, including poly(ADP-ribose) polymerase (PARPs), mono(ADP-ribosyl)-transferases (ARTs), NAD(+)-dependent deacetylases (sirtuins), tRNA 2'-phosphotransferases, and ADP-ribosyl cyclases (CD38 and CD157). Focus is given to the enzymatic reactions, mechanisms, structures, and biological functions.     

分子印迹聚合物研究:从小分子到生物大分子

分子印迹技术是一项制备功能聚合物材料的方法,其对印迹分子的专一性选择识别能力引起了人们的广泛关注。随着方法的基本确立和技术的逐渐成熟,其应用领域和范围不断扩大。本文在总结以往研究结果的基础上,对迄今为止进展相对缓慢的生物大分子印迹研究予以了特别关注,对相关的水环境下的分子识别问题进行了仔细的讨论,认真的分析了生物大分子印迹研究工作的难点和不利因素,对分子印迹技术的未来发展和应用前景进行了展望。     

磁性纳米颗粒在生物医学领域中的应用

磁性纳米颗粒作为一种新型纳米材料,在许多领域,特别是在生物医药、生物工程等方面具有广阔的应用前景.本文着重论述了近年来磁性纳米颗粒在生物分离、靶向给药、热疗以及磁共振成像对比剂等方面的应用,并对其应用前景进行了展望.     

Impact of international standards and initiatives on proficiency testing for medical laboratories

This paper is intended to briefly discuss several recent initiatives regarding External Quality Assessment (or Proficiency Testing) (PT/EQA) for medical laboratories in various parts of the world. While a brief paper cannot be comprehensive for all regions, it is possible to present some new standards and initiatives that are underway or proposed in many countries. Laboratory medicine was one of the first areas of laboratory testing to develop interlaboratory comparisons, and the first area where such comparisons became compulsory. Because of that, the medical field has often been the leader in the availability and use of PT/EQA, and has introduced many innovations that have been adopted in other areas. Perhaps other areas of testing will similarly adopt the developments discussed here, if they have not already done so. There are important developments in the medical area that are also occurring in other fields of testing, such as the growing number of countries that require some form of participation, and the increasing use of the Internet. These developments are important, but are not discussed further in this paper since they are occurring in many fields of testing.     

The spin-states and spin-transitions of mononuclear iron(II) complexes of nitrogen-donor ligands

A survey of mononuclear iron(II) complexes with heterocyclic N-donor ligation is presented. A brief introduction to spin-crossover chemistry and low-temperature spin-trapping is provided, since many of these compounds undergo thermal spin-transitions upon cooling or heating. These are highlighted, and the structural changes underlying spin-crossover are discussed where this is known. Materials showing spin-trapping behaviour following thermal quenching or irradiation at very low temperatures are also described.     

Sample preconcentration from dilute solutions on micro/nanofluidic platforms: A review

Biochemical detection plays a critical role in many analytical fields. For example, blood samples include many proteins with relevance to disease diagnosis and therapeutic monitoring. Foods and beverages contain a large number of chemicals and compounds which must be quantified and characterized to ensure their compliance with safety standards. Detecting trace amounts of contaminants in ambient air or water samples is essential in monitoring the environment and protecting human health. Therefore, effective techniques for performing the rapid and reliable detection of targeted analytes are required. Compared to conventional macroscale devices, microfluidic systems have many advantages, including a greater sensitivity, a faster response time, a reduced sample and reagent consumption, and a greater portability. Accordingly, many microfluidic systems for sample detection have been proposed in recent years. The performance of such devices relies on the target analyte being present in a sufficient concentration to enable its detection. In many biomedical, food testing and environmental applications, the detection limit was restricted. Thus, the sample must first be concentrated before the detection process is carried out. Accordingly, this review provides a comprehensive review of recent advances for sample preconcentration with emphasis on utilizing ion concentration polarization (ICP) effects in micro/nanofluidics platforms. We start with a brief introduction regarding the importance of preconcentration using micro/nanofluidics platforms, followed by in‐depth discussions of the ICP effects for the preconcentration and applications to biomedical analysis, food testing and environmental monitoring. Finally, the article concludes with a brief perspective on the future development of the field.     

Bioanalytical applications of SERS (surface-enhanced Raman spectroscopy)

Surface-enhanced Raman scattering (SERS) is a powerful technique for analyzing biological samples as it can rapidly and nondestructively provide chemical and, in some cases, structural information about molecules in aqueous environments. In the Raman scattering process, both visible and near-infrared (NIR) wavelengths of light can be used to induce polarization of Raman-active molecules, leading to inelastic light scattering that yields specific molecular vibrational information. The development of surface enhancement has enabled Raman scattering to be an effective tool for qualitative as well as quantitative measurements with high sensitivity and specificity. Recent advances have led to many novel applications of SERS for biological analyses, resulting in new insights for biochemistry and molecular biology, the detection of biological warfare agents, and medical diagnostics for cancer, diabetes, and other diseases. This trend article highlights many of these recent investigations and provides a brief outlook in order to assess possible future directions of SERS as a bioanalytical tool.     

Impact of international standards and initiatives on proficiency testing for medical laboratories

This paper is intended to briefly discuss several recent initiatives regarding External Quality Assessment (or Proficiency Testing) (PT/EQA) for medical laboratories in various parts of the world. While a brief paper cannot be comprehensive for all regions, it is possible to present some new standards and initiatives that are underway or proposed in many countries. Laboratory medicine was one of the first areas of laboratory testing to develop interlaboratory comparisons, and the first area where such comparisons became compulsory. Because of that, the medical field has often been the leader in the availability and use of PT/EQA, and has introduced many innovations that have been adopted in other areas. Perhaps other areas of testing will similarly adopt the developments discussed here, if they have not already done so. There are important developments in the medical area that are also occurring in other fields of testing, such as the growing number of countries that require some form of participation, and the increasing use of the Internet. These developments are important, but are not discussed further in this paper since they are occurring in many fields of testing.

     

Task-specific microextractions using ionic liquids

Ionic liquids (ILs) have been the focus of many scientific investigations including the field of analytical microextractions. ILs have many advantages over traditional organic solvents making them excellent candidates as extraction media for a variety of microextraction techniques. Many physical properties of ILs can be varied, and the structural design and make-up can be tuned to impart desired functionality for enhancement of analyte extraction selectivity, efficiency, and sensitivity. This paper provides a brief overview of ionic liquids and highlights trends in three important sample-preparation techniques, namely, single drop microextraction, solid-phase microextraction, and dispersive liquid–liquid microextraction in terms of performing task-specific extractions using these highly versatile solvents.     

纸张保存的化学

讨论了纸张保存过程中的某些化学问题,对纸张的酸性、酸性来源和纤维系酸催化水解以及影响纸张变质的其它因素进行了分析,评述了近年来在纸张脱酸、脱色和利用新的浆内施胶剂等方面研究取得的一些成果。     

蛋氨酸亚砜/蛋氨酸亚砜还原酶荧光检测研究进展

蛋白质蛋氨酸亚砜化是一种重要的氧化还原依赖的蛋白质翻译后修饰,不仅是氧化应激的重要标志物之一,也是一种蛋白质功能调控开关可影响活性氧信号转导,与一系列疾病尤其是神经退行性疾病的发生发展密切相关。 在许多生物体中,蛋氨酸亚砜还原酶是目前已经发现的唯一能将蛋白质蛋氨酸亚砜还原为蛋氨酸的物质,可以修复氧化损伤蛋白,恢复蛋白质功能,调控细胞氧还平衡,对相关疾病的治疗具有非常重要的意义。 本文重点介绍蛋氨酸亚砜和蛋氨酸亚砜还原酶的结构和催化机理,综述蛋氨酸亚砜和蛋氨酸亚砜还原酶荧光探针的部分研究进展,对该领域的研究前景进行展望。     

Graphene: materials in the Flatland (Nobel lecture)

Much like the world described in Abbott's "Flatland", graphene is a two-dimensional object. And, as "Flatland" is "A Romance of Many Dimensions", graphene is much more than just a flat crystal. It possesses a number of unusual properties which are often unique or superior to those in other materials. In this brief lecture I would like to explain the reason for my (and many other people's) fascination with this material, and invite the reader to share some of the excitement I've experienced while researching it.     

Fluoropolymer films in the photovoltaic industry

The unique combinations of properties that fluoropolymer exhibit are ideal for photovoltaic modules. Typical modules take advantage of fluoropolymers’ properties in many ways. This brief overview discusses the most common uses of fluoropolymers in the photovoltaic energy industry and some of the reasons behind their popularity.     

Organometallic chemistry related to applications for microelectronics in Japan

This is meant to be a brief overview of the developments of research activities in Japan on organometallic compounds related to their use in electronic and optoelectronic devices. The importance of organometallic compounds in the deposition of metal and semiconductor films for the fabrication of many electronic and opto-electronic devices cannot be exaggerated. Their scope has now extended to thin-film electronic ceramics and high-temperature oxide superconductors. A variety of organometallic compounds have been used as source materials in many types of processing procedures, such as metal–organic chemical vapor deposition (MOCVD), metalorganic vapor-phase epitaxy (MOVPE), metal–organic molecular-beam epitaxy (MOMBE), etc. Deposited materials include silicon, Group III–V and II–VI compound semiconductors, metals, superconducting oxides and other inorganic materials. Organometallic compounds are utilized as such in many electronic and optoelectronic devices; examples are conducting and semiconducting materials, photovoltaic, photochromic, electrochromic and nonlinear optical materials. This review consists of two parts: (I) research related to the fabrication of semiconductor, metal and inorganic materials; and (II) research related to the direct use of organometallic materials and basic fundamental research.     

Boesenbergia Pandurata Roxb., An Indonesian Medicinal Plant: Phytochemistry,Biological Activity,Plant Biotechnology

Boesenbergia pandurata Roxb. (Zingiberaceae), known as “temu kunci”, is one of the Indonesian medicinal plants. Its rhizome has been traditionally used in folk medicine for treatment of several diseases. Rhizome of B. pandurata contains essential oils and many flavonoid compounds that showed many interesting pharmacological activities, such as antifungal, antibacterial, antioxidant, etc. Interestingly, this plant has several prenylated flavonoid compounds, panduratins, that showed very promising of biological activities, especially as strong antifungal and antibacterial, anti-inflammatory, and anti-cancer. This paper aims to review chemical constituents of this plant and their pharmacological activities and also to give a brief view through biotechnological perspective concerning the several possibilities to produce several valuable prenylated flavonoids from this plant.     

薄层液/液界面电子转移动力学的研究进展

薄层循环伏安法是研究液/液界面电荷转移的一种新方法,具有简单、快速、易操作的优点。文章回顾了液/液界面电化学的发展历史,介绍了薄层法的实验原理,对其在电化学中的应用和研究进展进行了评述,总结了界面驱动力与电子转移速率的关系。     

Applications of ionic liquids in electrochemical sensors

Ionic liquids (ILs) are molten salts with the melting point close to or below room temperature. They are composed of two asymmetrical ions of opposite charges that only loosely fit together (usually bulky organic cations and smaller anions). The good solvating properties, high conductivity, non-volatility, low toxicity, large electrochemical window (i.e. the electrochemical potential range over which the electrolyte is neither reduced nor oxidized on electrodes) and good electrochemical stability, make ILs suitable for many applications. Recently, novel ion selective sensors, gas sensors and biosensors based on ILs have been developed. IL gels were found to have good biocompatibility with enzymes, proteins and even living cells. Besides a brief discussion of the properties of ILs and their general applications based on these properties, this review focuses on the application of ILs in electroanalytical sensors.