Surface Modification Strategy for Enhanced NO2 Capture in Metal–Organic Frameworks

The interaction strength of nitrogen dioxide (NO₂) with a set of 43 functionalized benzene molecules was investigated by performing density functional theory (DFT) calculations. The functional groups under study were strategically selected as potential modifications of the organic linker of existing metal–organic frameworks (MOFs) in order to enhance their uptake of NO₂ molecules. Among the functional groups considered, the highest interaction energy with NO₂ (5.4 kcal/mol) was found for phenyl hydrogen sulfate (-OSO₃H) at the RI-DSD-BLYP/def2-TZVPP level of theory—an interaction almost three times larger than the corresponding binding energy for non-functionalized benzene (2.0 kcal/mol). The groups with the strongest NO₂ interactions (-OSO₃H, -PO₃H₂, -OPO₃H₂) were selected for functionalizing the linker of IRMOF-8 and investigating the trend in their NO₂ uptake capacities with grand canonical Monte Carlo (GCMC) simulations at ambient temperature for a wide pressure range. The predicted isotherms show a profound enhancement of the NO₂ uptake with the introduction of the strongly-binding functional groups in the framework, rendering them promising modification candidates for improving the NO₂ uptake performance not only in MOFs but also in various other porous materials.     

孔梯度陶瓷纤维复合膜管的制备及特性

陶瓷过滤管具有孔隙率高、耐腐蚀、耐高温、机械强度高、便于清洗、使用寿命长等优点,是高温烟尘处理用的高效过滤元件.本文研制了一种具有梯度孔结构堇青石陶瓷纤维复合膜过滤元件,该过滤元件是由多孔支撑体、过渡层和分离膜层组成.其中支撑体、过渡层和分离层的气孔率分别为35～40;、50～60;和60～70;.文中主要分析了孔梯度陶瓷纤维复合膜管的材料结构和抗热震性能,同时对复合膜管进行含尘气体过滤的冷态模拟试验.对于烟气中粒径大于或等于0.1μm的颗粒,复合膜管的截留率达到99.8;以上.     

Packed-Fiber Solid Phase-Extraction Coupled with HPLC-MS/MS for Rapid Determination of Lipid Oxidative Damage Biomarker 8-Iso-Prostaglandin F2α in Urine

The 8-iso-prostaglandin F_2α (8-iso-PGF_2α) biomarker is used as the gold standard for tracing lipid oxidative stress in vivo. The analysis of urinary 8-iso-PGF_2α is challenging when dealing with trace amounts of 8-iso-PGF_2α and the complexity of urine matrixes. A packed-fiber solid-phase extraction (PFSPE)–coupled with HPLC-MS/MS–method, based on polystyrene (PS)-electrospun nanofibers, was developed for the specific determination of 8-iso-PGF_2α in urine and compared with other newly developed LC-MS/MS methods. The method, which simultaneously processed 12 samples within 5 min on a self-made semi-automatic array solid-phase extraction processor, was the first to introduce PS-electrospun nanofibers as an adsorbent for the extraction of 8-iso-PGF_2α and was successfully applied to real urine samples. After optimizing the PFSPE conditions, good linearity in the range of 0.05–5 ng/mL with R² > 0.9996 and a satisfactory limit of detection of 0.015 ng/mL were obtained, with good intraday and interday precision (RSD < 10%) and recoveries of 95.3–103.8%. This feasible method is expected to be used for the batch quantitative analysis of urinary 8-iso-PGF_2α.     

Development of Neuropeptide Y and Cell-Penetrating Peptide MAP Adsorbed onto Lipid Nanoparticle Surface

Functionalization of nanoparticles surfaces have been widely used to improve diagnostic and therapeutic biological outcome. Several methods can be applied to modify nanoparticle surface; however, in this article we focus toward a simple and less time-consuming method. We applied an adsorption method on already formulated nanostructured lipid carriers (NLC) to functionalize these nanoparticles with three distinct peptides sequences. We selected a cell-penetrating peptide (CPP), a lysine modified model amphipathic peptide (Lys(N₃)-MAP), CPP/drug complex, and the neuropeptide Y. The aim of this work is to evaluate the effect of several parameters such as peptide concentration, different types of NLC, different types of peptides, and incubation medium on the physicochemical proprieties of NLC and determine if adsorption occurs. The preliminary results from zeta potential analysis indicate some evidence that this method was successful in adsorbing three types of peptides onto NLC. Several non-covalent interactions appear to be involved in peptide adsorption with the possibility of three adsorption peptide hypothesis that may occur with NLC in solution. Moreover, and for the first time, in silico docking analysis demonstrated strong interaction between CPP MAP and NPY Y1 receptor with high score values when compared to standard antagonist and NPY.     

气粒混合物非灰辐射特性合并宽窄谱带K分布模型

气粒混合物辐射问题具有全场性、非灰性、耦合性等特点,准确预估高温燃气/粒子非灰辐射特性是非常重要的。本文将合并宽窄谱带K分布模础(CWNBCK)与离散坐标法(DOM)结合,开展了非灰气粒混合物辐射换热问题的模拟工作,分别验证了一维和三维情况下应用该模型的准确性,给出不同工况下的热流源项、壁面热流或辐射热流等。结果表明:该模型能够给出与SNB模型精度基本相同的结果,考虑其计算效率的提高,可以在工程实际中应用该模型计算非灰气粒混合物辐射换热。     

The Influence of the Flow-Pattern on Column Leaching Experiments: Formulation and Measurement by Radiotracer

The leaching of microconstituents from granular solid wastes is often studied by column experiments. The underlying assumption is that the flow is of the one-compartment or “backmix” type. The influence of small deviations from this ideal situation on the outcome of the leaching experiment depends slightly on the specific mass-transfer function of the trace involved. The deviation itself may be measured by a simple separate radiotracer experiment.     

A model of melting of rare gases within bubbles of crystalline metal matrix

Abstract

On the basis of experimental results obtained in the present and some other works a model of melting of rare gas solids within bubbles formed in a crystalline metal matrix as a result of ion implantation is proposed. Rare gas solid is supposed to melt on heating at the expense of the bubble volume expansion by emission of a dislocation loop. On this basis the melting temperature can be estimated as one which is enough to provide for a pressure inside a bubble sufficient for the initiation of the dislocation loop punching. Values of melting temperatures obtained in this way are in good agreement with available experimental data.     

Book reviews

This work is a thorough investigation on the major operating parameters of the programmable temperature vaporisation (PTV) inlet used for gas chromatographic injection, including injection mode and volume, inlet temperature, vent and purge flow rates. The results clearly demonstrate the advantage of large volume injection in enhancing the detection of polybrominated diphenyl ethers (PBDEs). Partial loss of injected PBDEs occurred during solvent venting and due to incomplete sample transfer. Such loss was minimised by lowering the initial inlet temperature and vent flow and elevating the final inlet temperature. The results show that 50 mL/min vent flow, as low as 0°C initial and higher than 300°C final inlet temperatures produced the relatively high responses. Two mass spectrometric parameters were also evaluated. Indoor dust, lake sediment and human placenta tissue samples were analysed to demonstrate reliability and sensitivity improvement of the PTV large volume injection.     

Analysis of PCBs in Biotic Matrices by Two-Dimensional GC-ECD

Abstract

The suitability of three GC-ECD systems for the separation of a model mixture containing various congeners of PCBs together with persistent chlorinated aromatics (pesticides and their metabolites, industrial chemicals) was tested. Analyses were performed on two parallel capillaries, the stationary phase of one of them was always in routine practice very common 5% phenyl-methylpolysiloxane, the second one was either 50% phenylmethylpolysiloxane or 7% phenyl-7% cyanopropyl-methylpolysiloxane. The number of unresolved (coeluted) analytes was significantly reduced in these systems and thus unbiased quantitation of PCBs and other components used for regulation was possible. The utilization of this type of multidimensional chromatography for rapid and reliable analysis of real samples (fish oil, human fat) was documented.