Zr (IV)-ninhydrin supported MCM-41 and MCM-48 as novel nanoreactor catalysts for the oxidation of sulfides to sulfoxides and thiols to disulfides

Modification of MCM-41 and MCM-48 mesoporous materials with bonded aminosilane species, Schiff base preparation by ninhydrin and finally complexation with zirconium, has attracted much attention in order to design catalyst with advanced applications in the oxidation of sulfides to sulfoxides and thiols to disulfides in the presence of hydrogen peroxide. In all oxidation of sulfides to sulfoxids 0.4 mL H₂O₂ used as oxidant in the presence of Zr(IV)-ninhydrin supported MCM-41 (0.01 g) or Zr(IV)-ninhydrin supported MCM-48 (0.005 g) at room temperature and solvent-free condition. Also the best conditions for oxidation of thiols to disulfides with 0.4 mL H₂O₂ were 0.005 g Zr(IV)-ninhydrin supported MCM-41 or Zr(IV)-ninhydrin supported MCM-48 at room temperature and in ethanol. These catalysts are characterized by SEM, XRD, TGA, FT-IR, EDS, ICP and BET analysis. Also the Turn over frequency (TOF) and Turn over number (TON) of catalysts are calculated. Obtained results by these heterogeneous catalysts revealed several advantages including short reaction times, simple workup, easy isolation and reusability.     

Surface modifications of polypropylene membranes used for blood filtration

The surface of two commercial meltblown polypropylene (PP) membranes, used for the filtration of blood products, were modified by wet chemistry treatments (carbodiimide, tosyl chloride and trihalogeno-triazines) in the case of the oxygen-plasma treated membrane (O₂-PP), and by photochemistry using molecular clips in the case of the native PP membrane. The most efficient technique uses trifluoro-triazine reagent for the activation of both hydroxyl- and carboxyl-functions of O₂-PP. It enables the fixation of amine-terminated molecules with high degrees of derivatization (∼700 pmol/cm²), without inducing modification of the membrane morphology nor cytotoxicity. Only a weak decrease of surface hydrophilicity was measured after the treatments and steam-sterilization. This method was applied for the grafting of peptides (Gly-Gly-Gly-Gly-Gly, Gly-Arg-Gly-Asp-Ser, home-made modified Leu-Asp-Val) on O₂-PP membranes incorporated into multi-layer filter devices. These modified filters showed improved properties of leukocyte depletion in blood filtration experiments, principally due to the wetting properties of the membranes.     

Formation of water-impermeable crust on sand surface using biocement

This paper examines the feasibility of using calcium-based biocement to form an impermeable crust on top of a sand layer. The biocement used was a mixture of calcium salt, urea, and bacterial suspension, which hydrolyzed urea with production of carbonate and an increase of the pH level. Applying 0.6 g of Ca per cm² of sand surface, the permeability of the biocemented sand can be reduced from 10⁻⁴ m/s to 1.6·10⁻⁷ m/s (or 14 mm/day) due to formation of the crust on sand surface. The rupture modulus (maximum bending stress) of the crust was 35.9 MPa, which is comparable with that of limestone. The formation of a water-impermeable and high strength crust layer on sand surface could be useful for the construction of aquaculture ponds in sand, stabilization of the sand dunes, dust fixation in the desert areas, and sealing of the channels and reservoirs in sandy soil.     

Vitamin D and Evening Primrose Oil Administration Improve Glycemia and Lipid Profiles in Women with Gestational Diabetes

Limited data are available assessing the effects of vitamin D and evening primrose oil (EPO) administration on markers of insulin resistance and lipid concentrations in gestational diabetes mellitus (GDM). This study was designed to evaluate the effects of vitamin D and EPO administration on insulin resistance and lipid concentrations among women with GDM. In this prospective randomized, double‐blind, placebo‐controlled clinical trial, 60 participants with GDM were divided into 2 groups of either 1000 IU vitamin D3 and 1000 mg EPO or placebo for 6 weeks. At the beginning and end of the study, fasting blood samples were obtained from the participants to measure related variables. After 6 weeks of intervention, changes in fasting plasma glucose (?3.6 ± 7.5 vs. +1.5 ± 11.4 mg/dL, P = 0.04), serum insulin concentrations (?2.0 ± 5.3 vs. +4.6 ± 10.7 µIU/mL, P = 0.004), homeostasis model of assessment (HOMA) insulin resistance (?0.5 ± 1.1 vs. +1.1 ± 2.5, P = 0.003), HOMA‐B cell function (?7.7 ± 23.3 vs. +17.4 ± 42.9, P = 0.007) and the quantitative insulin sensitivity check index (+0.01 ± 0.02 vs. ?0.01 ± 0.02, P = 0.007) in the vitamin D plus EPO group were significantly different from the placebo group. In addition, compared with the placebo, vitamin D and EPO supplementation resulted in significant reductions in serum TAG (?20.0 ± 54.3 vs. +34.3 ± 38.2 mg/dL, P < 0.001), VLDL (?4.0 ± 10.9 vs. +6.9 ± 7.6 mg/dL, P < 0.001), TC (?22.1 ± 32.6 vs. +5.3 ± 20.1 mg/dL, P < 0.001), LDL concentrations (?18.0 ± 25.5 vs. +1.8 ± 15.7 mg/dL, P = 0.001) and TC/HDL (?0.3 ± 0.4 vs. +0.3 ± 0.5 mg/dL, P < 0.001). We did not observe any significant effect of vitamin D and EPO supplementation on serum HDL concentrations. Clinical trial registration number: http://www.irct.ir : IRCT201509115623N52.     

Role of Organic Acids in Flux Enhancement of Polyamide Nanofiltration Membranes

A novel thin‐film composite (TFC) nanofiltration membrane containing hydrophilic organic additives was fabricated via interfacial polymerization. Three organic acids, i.e., lactic, maleic, and citric acid, served as aqueous‐phase additives and their role in membrane structure and nanofiltration membrane flux enhancement was investigated. Fourier transform‐infrared (FT‐IR) analysis confirmed the presence of organic acids in the polyamide (PA) layer. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses were applied to investigate the membrane morphology. The more carboxylic functional groups present in the additive resulted in higher hydrophilicity and porosity and flux was enhanced significantly compared to the neat PA membrane, while salt rejection was influenced only to a minor extent.     

Manufacturing Porous Materials Using Dabco-Based Ionic Liquid

Silicon - The long-chain ionic liquid (IL) hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide was used as a template to prepare the hexagonally ordered siliceous mesoporous molecular sieve MCM-41...     

Hydrogenation of Carbon Dioxide into Formic Acid by Aluminum Ligated NNN Pincer Fullerene Through Metal–Ligand H2O-Assisted Pathway: A Computational Study

Catalysis Letters - The AlH2-catalyzed hydrogenation of carbon dioxide into formic acid by a novel catalyst of aluminum ligated NNN pincerfullerene, AlH2-bis(imino)pyrollidinofullerene, was...     

Design of Zn1−xCuxO Nanocomposite Ag-Doped as an Efficient Antimicrobial Agent

Journal of Inorganic and Organometallic Polymers and Materials - This study aims at the preparation of antimicrobial nanoparticles hybrid based on silver (Ag) doped Zn1?xCuxO. Zn1?xCuxO...     

A configurable fluorescence sensing front-end for ultra-low power and high sensitivity applications

Analog Integrated Circuits and Signal Processing - This paper presents an ultra-low power, high sensitivity configurable CMOS fluorescence sensing front-end for implantable biosensors at...     

A Comparative Analysis of Data-Driven Models (SVR,ANFIS, and ANNs) for Daily Karst Spring Discharge Prediction

Water Resources Management - Spring discharge always illustrates the groundwater-flux and aquifer storage oscillations. Because of inherent heterogeneity in karst environments, it is essential to...