Mechanopathology of red blood cell diseases — Why mechanics matters

During the onset of a disease a cell may experience alterations in both the composition and organization of its cellular and molecular structures. These alterations may eventually lead to changes in its geometrical and mechanical properties such as cell size and shape, deformability and adhesion. As such, knowing how diseased cells respond to mechanical forces can reveal ways by which they differ from healthy ones. Here, we will present biomechanistic insights into red blood cell related diseases that manifest mechanical property changes and how they directly contribute to the pathophysiology of diseases. By conducting cell and molecular mechanics studies, not only can we elucidate changes in the structure-property-function relationship of diseased cells, we can also exploit the new knowledge gained to develop biomechanics based devices that may better detect and diagnose these diseases as well as help identify important biomechanical targets for possible therapeutic interventions.     

3-甲基丙烯酰胺基-9-乙基咔唑/过硫酸钾体系引发丙烯酰胺聚合

合成了可聚合芳香叔胺 - 3 甲基丙烯酰胺基 9 乙基咔唑 ,并与过硫酸钾组成氧化还原引发体系引发丙烯酰胺水溶液聚合 ,测定了聚合反应动力学 ,得到了超高分子量的聚丙烯酰胺。     

胜利原油〈350℃馏分常压气液平衡预测

通过对常压气液平衡的考察，结果表明正构烷烃模型分子－ＵＮＩＦＡＣ基因贡献法对胜利〈３５０℃馏分油是可行的，其预测准确性的Ｒａｕ－Ｋ模型最好，且优于或与ＳＲＫ型相当，能够满足工程计算要求。     

两亲性分子在聚丙烯表面的包埋及亲水改性

以两亲性的硬脂醇聚氧化乙烯基醚(AEO)为改性剂,采用表面包埋改性的方法对聚丙烯(PP)表面进行亲水改性。通过接触角、扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FT-IR)等分析方法,研究了表面溶胀、退溶胀、改性剂结构等因素对表面改性效果的影响。结果表明:经二甲苯(二甲苯在混合溶剂中的质量分数为80%)与环己酮混合溶剂溶胀处理,溶胀层位于PP表面的无定形区。以AEO-8为改性剂,采用真空干燥的退溶胀方式,改性表面的接触角低至20.6°。相分离及水取向作用能够促进改性剂的聚环氧乙烷(PEO)亲水段向包埋表面外层迁移,并赋予表面亲水性。     

The rylene colorant family--tailored nanoemitters for photonics research and applications

This Review summarizes the latest advances in the field of rylene dyes and rylene nanoemitters for applications in photonics, and describes the influence of the dye design on the optical properties, the self-assembly, the molecular interactions, as well as the labeling specificity of the compounds. The interplay between tailored (macro)molecular design and bulk/single-molecule spectroscopy enables complex processes to be explained, for example, the kinetics of energy-transfer processes or (bio)catalysis. Such investigations are essential for the ultimate design of optimized nanoemitters, and require a close cooperation between spectroscopists and preparative organic chemists.     

Thinner,Smaller, Faster: IR Techniques To Probe the Functionality of Biological and Biomimetic Systems

New techniques in vibrational spectroscopy are promising for the study of biological samples as they provide exquisite spatial and/or temporal resolution with the benefit of minimal perturbation of the system during observation. In this Minireview we showcase the power of modern infrared techniques when applied to biological and biomimetic systems. Examples will be presented on how conformational changes in peptides can be traced with femtosecond resolution and nanometer sensitivity by 2D IR spectroscopy, and how surface‐enhanced infrared difference absorption spectroscopy can be used to monitor the effect of the membrane potential on a single proton‐transfer step in an integral membrane protein. Vibrational spectra of monolayers of molecules at basically any interface can be recorded with sum‐frequency generation, which is strictly surface‐sensitive. Chemical images are recorded by applying scanning near‐field infrared microscopy at lateral resolutions better than 50 nm.     

Influence of weakly bound adduct ions on breath trace gas analysis by selected ion flow tube mass spectrometry (SIFT-MS)

This paper describes how weakly bound adduct ions form when the precursor ions used in selected ion flow mass spectrometry, SIFT-MS, analyses, viz. H₃O⁺, NO⁺ and O₂⁺, associate with the major components of air and exhaled breath, N₂, O₂ and CO₂. These adduct ions, which include H₃O⁺N₂, H₃O⁺CO₂, NO⁺CO₂, O₂⁺O₂ and O₂⁺CO₂, are clearly seen when dry air containing 5% CO₂ (typical of that in exhaled breath) is analysed using SIFT-MS. These adduct ions must not be misinterpreted as characteristic product ions of trace gases; if so, serious analytical errors can result. However, when exhaled breath is analysed these adduct ions are partly removed by ligand switching reactions with the abundant water molecules and the problems they represent are alleviated. But the small fractions of the adduct ions that remain in the SIFT-MS spectra, and especially when they are isobaric with genuine characteristic product ion of breath trace gases, can result in erroneous quantifications; such is the case for H₃O⁺N₂ interfering with breath ethanol analysis and H₃O⁺CO₂ with breath acetaldehyde analysis. However, these difficulties can be overcome when the isobaric adduct ions are properly recognised and excluded from the analyses; then these two important compounds can be properly quantified in breath. The presence of O₂⁺CO₂ in the product ion spectra interferes with the analysis of CS₂ present at low levels in exhaled breath. It is likely that similar problems will occur as other trace compounds are detected in exhaled breath when consideration will have to be given to the possibility of overlapping between their characteristic product ions and ions produced by hitherto unknown reactions. Similar problems are evident in other systems; for example, H₃O⁺CH₄ adduct ions are observed in both SIFT-MS analyses of methane rich mixtures like biologically generated waste gases and in model planetary atmospheres.     

Singlet and triplet state dynamics of charge and hydride transfer reactions of OD (XΣ) with propyne

We report a crossed beam study of the title reactions in the collision energy range from 0.45 to 1.23 eV (43–119 kJ/mol). Both reactions are exoergic and proceed as direct processes on a time scale much less than the rotational period of the transient association complex of approaching reactants. The charge transfer process takes place with zero momentum transfer. Density Functional Theory calculations of the structures of reactive intermediates show that a plausible pathway for hydride transfer involves initial charge transfer on a triplet surface, followed by intersystem crossing to the singlet manifold. This process is followed by rapid hydrogen atom transfer to form an intermediate that dissociates smoothly to products. The kinematics of the heavy + light-heavy mass combination result in mixed energy release at the lowest collision energy, in which both the breaking and forming bonds are extended, while at higher collision energies, the incremental translational energy in the reactants appears preferentially in product translation, consistent with induced repulsive energy release.