Efficient Diethylzinc/Gallic Acid and Diethylzinc/Gallic Acid Ester Catalytic Systems for the Ring-Opening Polymerization of rac-Lactide.

Polylactide (PLA) represents one of the most promising biomedical polymers due to its biodegradability, bioresorbability and good biocompatibility. This work highlights the synthesis and characterization of PLAs using novel diethylzinc/gallic acid (ZnEt₂/GAc) and diethylzinc/propyl gallate (ZnEt₂/PGAc) catalytic systems that are safe for human body. The results of the ring-opening polymerization (ROP) of rac-lactide (rac-LA) in the presence of zinc-based catalytic systems have shown that, depending on the reaction conditions, "predominantly isotactic", disyndiotactic or atactic PLA can be obtained.

Effect of interaction between anionic surfactants and poly(piperazine-amide) nanofiltration membranes used for chromium(III) recovery from saline solution.

The effect of the anionic surfactant on the permeation properties of the nanofiltration (NF) membranes used for chromium(III) recovery from saline solution at low pH have been presented in this paper. The membrane surface layer performance periodically modified by sodium dodecyl sulphate (SDS) solution has been studied with measurements of zeta potential, atomic force microscopy (AFM) and permeability coefficient of tested membranes. It was found that the membrane surface layer modification by SDS caused a substantial reduction in the possibility of separation of loose NF membrane characterized by a high density of positively charged groups activating under the effect of the low pH of the saline solutions (HL membrane).

Impella LD microaxial pump supporting combined mitral and coronary surgery in a patient with dilated cardiomyopathy. A short bridge to recovery?

Cardiac surgeons have to face the problem of impaired left ventricle function in patients undergoing routine valve or coronary procedures. The intra-aortic balloon pump is not always effective in preventing cardiac failure. The idea of using a microaxial rotating pump as a short-term perioperative support seems to be a convenient solution.

Consumption Safety of Pastries, Confectioneries, and Potato Products as Related to Fat Content.

Study Aim: To determine the content of the main groups of fatty acids in pastries, confectionery, and potato products, paying special attention to trans fatty acids and the products of fat oxidation and hydrolysis, as factors affecting the safety of consumption.

Methods: A total of 157 products were collected in Poland in 2009-2010. In fats extracted from samples, products of oxidation and hydrolysis were assayed using peroxide (PV), anisidine (AnV), and acid (AV) values.

Stability of cosmetic emulsion containing different amount of hemp oil.

Objective: The aim of the study was to determine the optimal conditions, that is the content of hemp oil and time of homogenization to obtain stable dispersion systems.

Methods: For this purpose, six emulsions were prepared, their stability was examined empirically and the most correctly formulated emulsion composition was determined using a computer simulation. Variable parameters (oil content and homogenization time) were indicated by the optimization software based on Kleeman's method.

Novel zinc-catalytic systems for ring-opening polymerization of ε-caprolactone.

Polycaprolactone (PCL) is a biodegradable synthetic polymer that is currently widely used in many pharmaceutical and medical applications. In this paper we describe the coordination ring-opening polymerization of ε-caprolactone in the presence of two newly synthesized catalytic systems: diethylzinc/gallic acid and diethylzinc/propyl gallate. The chemical structures of the obtained PCLs were characterized by 1H- or 13C-NMR, FTIR spectroscopy and MALDI TOF mass spectrometry.

Fractionation and mobility of Cu, Fe, Mn, Pb and Zn in the road dust retained on noise barriers along expressway - a potential tool for determining the effects of driving conditions on speciation of emitted particulate metals.

Road dust (RD) retained on noise barriers was used as a monitor of emission of traffic-related metals from expressway. By using SEM/EDX analysis it has been revealed that the main components of this particulate were irregular fine aggregates and tire debris with a ragged porous structure and with inclusions derived from the road surface. The results of chemical fractionation showed that driving conditions influence strongly a distribution pattern of Cu, whereas the atmospheric corrosion process affects a distribution pattern of Zn.

Enzymatically interesterified fats based on mutton tallow and walnut oil suitable for cosmetic emulsions.

Objective: Formation of emulsion systems based on interesterified fats was the objective of the study. Enzymatic interesterification was carried out between enzymatic mutton tallow and walnut oil in the proportions 2 : 3 (w/w) to produce fats not available in nature. At the beginning of the interesterification process, the balance between the interesterification and fat hydrolysis was intentionally disturbed by adding more water to the catalyst (Lipozyme IR MR) of the reaction to produce more of the polar fraction monoacylglycerols [MAGs] and diacylglycerols [DAGs].

Treatment of multiple osteoporotic vertebral compression fractures by percutaneous cement augmentation.

Purpose: Vertebral compression fractures cause significant pain and some patients are debilitated by the pain due to the fracture. Conventional surgery carries a high risk and has a poor outcome. Vertebroplasty is a minimally invasive surgical procedure, which in vertebral fractures restores stability and diminishes pain.

Supported liquid membrane system for Cr(III) separation from Cr(III)/Cr(VI) mixtures.

This paper presents the results of analyses of the chromium(III) transport process from mixtures of Cr(III)/Cr(VI) ions using supported liquid membranes (SLM), in which dinonylnaphthalene sulfonic acid (DNNSA) and di(2-ethylhexyl) phosphoric acid (D2EHPA) were used as carriers. In both cases the membrane worked as a selective barrier for Cr(VI) ions. The increase in both the time of Cr(VI) ions-carrier interaction and the Cr(VI) concentration in the feed phase negatively influenced the Cr(III) separation.