Fe3O4@MCM-48–SO3H:合成苯并[f]色烯并[2,3-d]嘧啶酮的高效、可磁性分离纳米催化剂（英文）

Sulfonic acid groups were grafted onto three different types of synthesized magnetic nanoparticles, namely Fe3O4, Fe3O4@SiO2, and Fe3O4@MCM‐48. The sulfonic acid‐functionalized nanoparticles were evaluated as catalysts for the synthesis of 5‐aryl‐1H‐benzo[f]chromeno[2,3‐d]pyrimidine‐2,4(3H,5H)‐dione derivatives in terms of activity and recyclability. Their catalytic activities were compared with that of the homogeneous acid catalyst 1‐methylimidazolium hydrogen sulfate ([HMIm][HSO4]). The activity of Fe3O4@MCM‐48–SO3H was comparable to those of the other heter‐ogeneous and homogeneous catalysts.     

Broad-Band Polarizing Light Beam Splitter Based on a Multilayer Thin-Film Coating

Journal of Applied Spectroscopy - A polarizing light beam splitter is created in the form of two Dove prisms of BK7 glass with a multilayer thin-fi lm coating made of two periodic substructures...     

Separation of short and medium-chain fatty acids using capillary electrophoresis with indirect photometric detection: Part I: Identification of fatty acids in rat feces

Short and medium-chain fatty acids (SMCFAs) are known as essential metabolites found in gut microbiota that function as modulators in the development and progression of many inflammatory conditions as well as in the regulation of cell metabolism. Currently, there are few simple and low-cost analytical methods available for the determination of SMCFA. This report focuses on SMCFA analysis utilizing CE with indirect photometric detection (CE-IPD). A ribonucleotide electrolyte, 5’-adenosine mono-phosphate (5’-AMP), is investigated as an IPD reagent due to its high molar absorptivity and dynamic reserve compatible with separation and detection of SMCFA. The operating parameters like the composition of organic solvent, millimolar concentrations of the complexing agent (alpha-cyclodextrin), 5’-AMP and non-absorbing electrolyte (boric acid), as well as the applied voltage, are optimized for resolution, efficiency, and signal-to-noise ratio. A baseline resolution of all nine SMCFAs is achieved in less than 15 min. Additionally, the developed CE-IPD method shows promising potential to identifying SMCFA in rat fecal supernatant. The presented analytical assay is simple, economical, and has considerably good repeatability. The intraday and interday RSD of less than 1 and 2% for relative migration time, as well as less than 14 and 15% for peak area, respectively, were obtained for SMCFA in fecal solution.     

Numerical simulation of nanofluid turbulent flow in a double-pipe heat exchanger equipped with circular fins

Journal of Thermal Analysis and Calorimetry - In this study, the thermal and flow characteristics of a nanofluid were evaluated numerically in a circular finned double-pipe heat exchanger. A 3D CFD...     

Extraction and determination of organophosphorus pesticides in water samples by a new liquid phase microextraction-gas chromatography-flame photometric detection

A rapid, sensitive and efficient liquid phase microextraction (LPME) method was developed to determine trace concentrations of some organophosphorus pesticides in water samples. This method combines liquid phase microextraction with gas chromatographic (GC) analysis in a simple and inexpensive apparatus involving very little organic solvent consumption. It involves exposing a floated drop of an organic solvent on the surface of aqueous solution in a sealed vial. Experimental parameters which control the performance of LPME such as type of organic solvent, organic solvent and sample volumes, sample stirring rate, sample solution temperature, salt addition and exposure time were investigated and optimized. Finally, the enrichment factor, dynamic linear range (DLR), limit of detection (LOD) and precision of the method were evaluated by the water samples spiked with organophosphorus pesticides. Using optimum extraction conditions, very low detection limits (0.01-0.04 μg L⁻¹) and good linearities (0.9983 < r² < 0.9999) were achieved. The LPME was performed for determination of organophosphorus pesticides in different types of natural water samples and acceptable recoveries (96-104%) and precisions (3.5 < R.S.D.% < 8.9) were obtained. The results suggested that the newly proposed LPME method is a rapid, accurate and effective sample preparation method and could be successfully applied for extraction and determination of organophosphorus pesticides in water samples.     

Mouse bone marrow‐derived mesenchymal stem cell response to nanostructured titanium substrates produced by high‐pressure torsion

Mesenchymal stem cells (MSCs) with the ability to differentiate into various mesoderm‐like cells are known to migrate to various organs to repair injured tissues. They can attach to the implant surface, differentiate into bone‐forming cells, and ultimately osseointegrate with the prosthesis. This study investigates bone marrow‐derived mesenchymal stem cellular response to the grain structure of titanium substrates produced by high‐pressure torsion and annealing processes. Cell attachment, proliferation, viability, and morphology are evaluated on the surface of differently processed nanostructured and coarse‐grained samples. The bacterial adhesion and calcium phosphate crystal formation and growth are also assessed on the surface of the substrates. The nanostructured titanium shows significantly higher cell adhesion, proliferation, spreading, and viability compared with the untreated and coarse‐grained titanium substrates. The adhesion of bacteria is lower and surface bioactivity is higher on the surface of the nanostructured titanium substrate. The results demonstrate the superior MSC compatibility, antibacterial efficacy, and surface bioactivity of the nanostructured titanium substrates, which could lead to early implant fixation and improved osseointegration. Copyright © 2012 John Wiley & Sons, Ltd.     

Evolution of Pore-Scale Morphology of Oil Shale During Pyrolysis: A Quantitative Analysis

This article describes experimental results and the numerical validation for multiphase, multicomponent evaporation in porous media 1d flow. We apply the model of Lindner et al. (Transp. Porous Media 112(2):313–332, 2016. doi: 10.1007/s11242-016-0646-6). The permeability of the porous medium is measured in an additional setup with a constant head permeameter to verify the validity of Darcy flow. The heat losses are considered in an analytical approach of correlating measured temperatures and heat inputs with enthalpies. A method of interpreting the experimental results is discussed to determine the phase state. We can show good qualitative agreement of the shift and position of the evaporation region when varying boundary conditions such as mass flux, concentration and heat input.     

Facile and efficient protocols for C–C and C–N bond formation reactions using a superparamagnetic palladium complex as reusable catalyst

Research on Chemical Intermediates - Facile and efficient protocols for some multicomponent coupling reactions such as the Suzuki reaction and synthesis of polyhydroquinoline and...