Photocatalytic functionalization of thin-layer membranes using a monomer truncation strategy.

We present the design and synthesis of two new organic polymer films making use of a liquid-liquid interfacial amine-acid chloride polymerization strategy. One of them was additionally functionalized in situ by the anchoring of N-phenyl-phenothiazine through a monomer truncation strategy, which endowed it with photocatalytic activity. This photoactive film displays interesting luminescence phenomena that were used for the oxidation of a variety of sulphides to their corresponding sulfoxides and reduction of aryl bromines.

NGS of microRNAs Involved in Cardioprotection Induced by Sevoflurane Compared to Propofol in Myocardial Revascularization Surgery: The ACDHUVV-16 Clinical Trial.

BACKGROUND: Numerous studies have demonstrated that halogenated agents elicit myocardial conditioning effects when administered perioperatively in cardiac surgery. Recent evidence has been published on the benefits of maintaining exposure to halogenated agents during the early postoperative period. The enzymatic mechanisms by which this beneficial effect is exerted were explained recently. OBJECTIVES: Our study was performed to investigate whether this phenomenon is mediated by either the activation or suppression of miRNAs targeted by halogenated anesthetics. METHODS: A double-blind, two-stage trial was conducted. The results of the first stage of the trial are presented in this paper. The sample was composed of patients undergoing off-pump myocardial revascularization surgery. Patients were randomized to receive either sevoflurane [S] or propofol [P] during the intraoperative and early postoperative period (during the first six hours after the intervention). Hemodynamics (heart rate, blood pressure, central venous pressure, cardiac index, systolic volume index, LVEF) and myocardial enzymes (troponin I) were monitored at six hour intervals during the first 48 hours. In the first stage of the trial, blood was drawn for gene sequencing from eight patients (four per group) at baseline and at 24 h. In the second stage of the study, a qPCR analysis was performed of the miRNAs identified as significant by gene sequencing. Levels of cardioprotective enzymes (serine/threonine protein kinase (Akt), tumor necrosis factor alpha (TNFα), extracellular regulated protein kinase (ERK 1/2), and caspase 3) were measured to assess their role in myocardial conditioning pathways. The purpose was to identify the miRNAs that play a major role in myocardial conditioning induced by halogenated agents. Concentrations of cardioprotective enzymes were higher in patients who received sevoflurane than the patients who were administered propofol. RESULTS: NGS differences were observed between baseline and 24-h values in the two study groups. In group P, miRNA 197-3p was overexpressed, whereas miRNAs 4443 and 1294, 708-3p were underexpressed. In group S, miRNAs 615-3p, 4466, 29, 937-3p, 636, 197-3P, 184, 4685, 296-3p, 147b, 3199, 6815, 1294 and 3176 were underexpressed; whereas 708-3p was overexpressed. qPCR showed significant variations in miRNAs 197-3p, 4443, 708-3p and 1294 in the P group, and in miRNAs 937-3p, 636, 197- 3p, 296-3p and 708-3p in the S group. CONCLUSION: In the P Group, changes in the expression of some miRNAs were associated with lower concentrations of the enzymes involved in myocardial pre- and postconditioning. In contrast, in Group S, variations in miRNAs were associated with the activation of mediators of anesthetic-induced pre- and post-conditioning, a reduction in cell apoptosis, and a decrease in caspase and TnBF alpha concentrations. Changes in these miRNAs were associated with better prognosis in patients with ischemic heart disease. The main limitation of this study will be overcome in the second stage of the trial, where the specific role of each miRNA will be determined.

Onset of chiral adenine surface growth.

The structure and stability of adenine crystals and thin layers has been studied by using scanning tunneling microscopy, X-ray diffraction, and density functional theory calculations. We have found that adenine crystals can be grown in two phases that are energetically quasi-degenerate, the structure of which can be described as a pile-up of 2D adenine planes. In each plane, the structure can be described as an aggregation of adenine dimers. Under certain conditions, kinetic effects can favor the growth of the less stable phase. These results have been used to understand the growth of adenine thin films on gold under ultra-high vacuum conditions. We have found that the grown phase corresponds to the α-phase, which is composed of stacked prochiral planes. In this way, the adenine nanocrystals exhibit a surface that is enantiopure. These results could open new insight into the applications of adenine in biological, medical, and enantioselective or pharmaceutical fields.

Growth of textured adenine thin films to exhibit only chiral faces.

The growth of adenine on Au(111) from the submonolayer up to several microns film thickness is studied by combining STM and surface X-ray diffraction techniques. The study shows that adenine thin films are composed of highly textured crystallites with the reported α-adenine crystal structure in such a way that they only exhibit (001)-faces. Such faces, with chiral p2 symmetry planes, have an average size of 15 nm. Thus, the formed adenine films reported herein, which expose only chiral and biocompatible faces, might find applications such as enantioselective heterogeneous catalysts for the chemical and pharmaceutical industries.

Phase behavior of aqueous dispersions of mixtures of N-palmitoyl ceramide and cholesterol: a lipid system with ceramide-cholesterol crystalline lamellar phases.

Ceramides are particularly abundant in the stratum corneum lipid matrix, where they determine its unusual mesostructure, are involved in the lateral segregation of lipid domains in biological cell membranes, and are also known to act as signaling agents in cells. The importance attributed to ceramides in several biological processes has heightened in recent years, demanding a better understanding of their interaction with other membrane components, namely, cholesterol. Structural data concerning pure ceramides in water are relatively scarce, and this is even more the case for mixtures of ceramides with other lipids commonly associated with them in biological systems. We have derived the thermotropic binary phase diagram of mixtures of N-palmitoyl- D-erythro-sphingosine, C16:0-ceramide, and cholesterol in excess water, using differential scanning calorimetry and small- and wide-angle X-ray diffraction. These mixtures are self-organized in lamellar mesostructures that, between other particularities, show two ceramide to cholesterol crystalline phases with molar proportions that approach 2:3 and 1:3. The 2:3 phase crystallizes in a tetragonal arrangement with a lamellar repeat distance of 3.50 nm, which indicates an unusual lipid stacking, probably unilamellar. The uncommon mesostructures formed by ceramides with cholesterol should be considered in the rationalization of their singular structural role in biological systems.