Macromolecular ion accelerator

Presented herein are the development of macromolecular ion accelerator (MIA) and the results obtained by MIA. This new instrument utilizes a consecutive series of planar electrodes for the purpose of facilitating stepwise acceleration. Matrix-assisted laser desorption/ionization (MALDI) is employed to generate singly charged macromolecular ions. A regular Z-gap microchannel plate (MCP) detector is mounted at the end of the accelerator to record the ion signals. In this work, we demonstrated the detection of ions with the mass-to-charge (m/z) ratio reaching 30,000,000. Moreover, we showed that singly charged biomolecular ions can be accelerated with the voltage approaching 1 MV, offering the evidence that macromolecular ions can possess much higher kinetic energy than ever before.     

生物高分子磁性微球的研究进展

磁性高分子微球是近二十年来研究的一类新型功能材料。拟从生物高分子磁性微球的制备、结构、性能和应用等几个方面综述近年来国内外有关磁性高分子微球的研究状况。     

聚醚胺型高分子表面活性剂的修饰及表征

通过接枝硬脂酸对聚醚胺Jeffamine ED2003的结构进行修饰,合成了一种新型的聚醚酰胺高分子表面活性剂（ED2003-fa18）。通过红外光谱,氢核磁共振波谱,元素分析对产物进行了分析表征,结果表明成功合成了ED2003-fa18。     

A Tool for Interrogation of Macromolecular Structure

Our program BABELPDB allows browsing and interrogating the native and derived structural features of biomacromolecules using data obtained from the Protein Data Bank （PDB）. Major features of BABELPDB are： （1） convert from PDB to other formats, （2） add or remove H-atoms, （3） strip the crystallization water molecules and （4） separate the ct-carbons （Cα）. The co-ordinates obtained with BABELPDB permit characterizing the presence of H-bonds. The algorithm for detecting H-bonds is implemented in our program TOPO for the theoretical simulation of the molecular shape, An example is given to illustrate the capabilities of the software： the calculation of the fractal dimension of the lysozyme molecule with （1.908） and without （1.920） H-atoms. The figures compare well with reference calculations performed with our version of program GEPOL and results from Pfeifer et al. For proteins, Cα-skeleton extracted with BABELPDB allows drawing the ribbon image, which determines their secondary structure.     

一种葛根素大分子前药的合成与表征

葛根素(Puerarin)临床应用广泛,但是其水溶性低,影响疗效的更好发挥.将葛根素键合到具有良好生物相容性、可降解的水溶性聚天冬酰胺衍生物(PDHEA)上,合成了葛根素前药(PDHEA-P),并通过FT-IR、1H-NMR 验证了目标产物.研究表明,葛根素前药的水溶性大大提高,所得前药的缓释性能良好.     

Macromolecular Crystallography and Structural Biology Databases at NIST

In the late 1970s, macromolecular crystallography at NIST began with collaboration between NIST and NIH to establish a single-crystal neutron diffractometer. This instrument was constructed and employed to solve a number of crystal structures: bovine ribonuclease A, bovine-ribonuclease-uridine vanadate complex, and porcine insulin. In the mid 1980s a Biomolecular Structure Group was created establishing NIST capabilities in biomolecular singe-crystal x-ray diffraction. The group worked on a variety of structural problems until joining the NIST/UMBI Center for Advanced Research in Biotechnology (CARB) in 1987. Crystallographic studies at CARB were then focused on protein engineering efforts that included among others chymosin, subtilisin BPN'', interleukin 1β, and glutathione S-transferase. Recently, the structural biology efforts have centered on enzymes in the chorismate metabolic pathways involved in amino acid biosynthesis and in structural genomics that involves determining the structures of “hypothetical” proteins to aid in assigning function. In addition to crystallographic studies, structural biology database activities began with the formal establishment of the Biological Macro-molecule Crystallization Database in 1989. Later, in 1997, NIST in partnership with Rutgers and UCSD formed the Research Collaboratory for Structural Bioinformatics that successfully acquired the Protein Data Bank. The NIST efforts in these activities have focused on data uniformity, establishing and maintaining the physical archive, and working with the NMR community.     

大分子自组装体系及自组装功能膜结构的研究

本文主要介绍了３种大分子自组装体系，含硫化合物的在重金属表面的自组装功能膜、聚合物在溶液状态下的自组装体系和聚合物基材上的自组装功能膜。文中还介绍了表征自组分析方法，着重介绍了用于自组装功能膜表面、界面结构分析的两种，红外光谱法和原子力显微镜。     

Bioactive Polymers 62. A Novel Macromolecular Drug Based on 5-Acetylamino-2-Sulfamoyl-1,3,4 Thiodiazole

Abstract

The condensation reaction of 5-acetylamino-2-sulfamoyl-1,3,4 thiodiazole (acetazolamide) on the poly(acrylic acid-co-styrene) copolymer was studied, with a view to obtaining a retard drug. Coupling was performed in a THF medium in the presence of dicyclohexylcarbodiimide as activator. The diuretic effect of the newly obtained drug was checked in rats.     

天然高分子纳米颗粒基因载体的研究进展

基因治疗是用于人类疾病治疗的一种新方法.基因载体系统是基因治疗面临的一个严峻挑战.基因载体包括病毒载体和非病毒载体,目前基因治疗中使用的主要是病毒载体.病毒载体具有转染率高的优点,但是却存在着安全性差等缺点,因此非病毒载体越来越受到关注.纳米颗粒是一种很有研究潜力的非病毒载体,其中基于天然高分子材料的纳米颗粒基因载体具有许多优良的特性.主要就天然高分子纳米颗粒的研究现状进行了综述.     

Bioactive Polymers 62. A Novel Macromolecular Drug Based on 5-Acetylamino-2-Sulfamoyl-1,3,4 Thiodiazole

The condensation reaction of 5-acetylamino-2-sulfamoyl-1,3,4 thiodiazole (acetazolamide) on the poly(acrylic acid-co-styrene) copolymer was studied, with a view to obtaining a retard drug. Coupling was performed in a THF medium in the presence of dicyclohexylcarbodiimide as activator. The diuretic effect of the newly obtained drug was checked in rats.     

膨胀石墨在防静电高分子材料中的应用

综述了高分子材料抗静电性能的重要性;分析了防静电高分子材料的研究现状;阐述了膨胀石墨作为新型导电填料在防静电高分子材料中的应用;指出膨胀石墨以其优良的导电性能及所呈现出的纳米特性必将在功能性包装材料中得到更广泛的应用.     

Pros and Cons: Supramolecular or Macromolecular: What Is Best for Functional Hydrogels with Advanced Properties?

Hydrogels are fascinating soft materials with unique properties. Many biological systems are based on hydrogel-like structures, underlining their versatility and relevance. The properties of hydrogels strongly depend on the structure of the building blocks they are composed of, as well as the nature of interactions between them in the network structure. Herein, gel networks made by supramolecular interactions are compared to covalent macromolecular networks, drawing conclusions about their performance and application as responsive materials.     

Macromolecular dynamics in red blood cells investigated using neutron spectroscopy

We present neutron scattering measurements on the dynamics of haemoglobin (Hb) in human red blood cells (RBCs) in vivo. Global and internal Hb dynamics were measured in the ps to ns time and Å length scales using quasi-elastic neutron backscattering spectroscopy. We observed the cross over from global Hb short-time to long-time self-diffusion. Both short- and long-time diffusion coefficients agree quantitatively with predicted values from the hydrodynamic theory of non-charged hard-sphere suspensions when a bound water fraction of around 0.23 gram H₂O per gram Hb is taken into account. The higher amount of water in the cells facilitates internal protein fluctuations in the ps time scale when compared with fully hydrated Hb powder. Slower internal dynamics of Hb in RBCs in the ns time range were found to be rather similar to results obtained with fully hydrated protein powders, solutions and Escherichia coli cells.     

New Concepts and Applications in the Macromolecular Chemistry of Fullerenes

A new classification on the different types of fullerene‐containing polymers is presented according to their different properties and applications they exhibit in a variety of fields. Because of their interest and novelty, water‐soluble and biodegradable C₆₀‐polymers are discussed first, followed by polyfullerene‐based membranes where unprecedented supramolecular structures are presented. Next are compounds that involve hybrid materials formed from fullerenes and other components such as silica, DNA, and carbon nanotubes (CNTs) where the most recent advances have been achieved. A most relevant topic is still that of C₆₀‐based donor‐acceptor (D–A) polymers. Since their application in photovoltaics D–A polymers are among the most realistic applications of fullerenes in the so‐called molecular electronics. The most relevant aspects in these covalently connected fullerene/polymer hybrids as well as new concepts to improve energy conversion efficiencies are presented. The last topics disccused relate to supramolecular aspects that are in involved in C₆₀‐polymer systems and in the self‐assembly of C₆₀‐macromolecular structures, which open a new scenario for organizing, by means of non‐covalent interactions, new supramolecular structures at the nano‐ and micrometric scale, in which the combination of the hydrofobicity of fullerenes with the versatility of the noncovalent chemistry afford new and spectacular superstructures.     

Macromolecular Scaffolding: The Relationship Between Nanoscale Architecture and Function in Multichromophoric Arrays for Organic Electronics

The optimization of the electronic properties of molecular materials based on optically or electrically active organic building blocks requires a fine‐tuning of their self‐assembly properties at surfaces. Such a fine‐tuning can be obtained on a scale up to 10 nm by mastering principles of supramolecular chemistry, i.e., by using suitably designed molecules interacting via pre‐programmed noncovalent forces. The control and fine‐tuning on a greater length scale is more difficult and challenging. This Research News highlights recent results we obtained on a new class of macromolecules that possess a very rigid backbone and side chains that point away from this backbone. Each side chain contains an organic semiconducting moiety, whose position and electronic interaction with neighboring moieties are dictated by the central macromolecular scaffold. A combined experimental and theoretical approach has made it possible to unravel the physical and chemical properties of this system across multiple length scales. The (opto)electronic properties of the new functional architectures have been explored by constructing prototypes of field‐effect transistors and solar cells, thereby providing direct insight into the relationship between architecture and function.