Evolution of the Pt layer deposited on MgO(001) by pulsed laser deposition as a function of the deposition parameters: a scanning tunneling microscopy and energy dispersive X-ray diffractometry/reflectometry study

A combined ultrahigh vacuum scanning tunneling microscopy (STM-UHV) and energy dispersive X-ray diffractometry/reflectometry (EDXD/EDXR) study of the evolution of face-centered cubic (fcc) Pt layer growth on MgO(100) by pulsed laser deposition as a function of the process parameters such as deposition temperature and deposition duration has been carried out. The aim of this study is to define the best experimental conditions to obtain a controlled film deposition selective on the Pt growth direction (either [111] or [002]). The evolution of the Pt surface morphology as a function of the deposition temperature (T(dep)) from 300 to 700 degrees C has been studied with STM and ED techniques. Results show that the Pt surface, characterized at T(dep) = 300 degrees C by a 3D island morphology, evolves at higher temperatures to a morphology in which the original islands coexist with a distribution of orthogonal 2D stripes. The two features can be associated with the [111] and [002] Pt growth directions of the fcc phase, respectively. For T(dep) = 700 degrees C, the island morphology of the (111) face completely disappears, while the merging process of the (002) stripes reaches completion. The evolution of the morphology at T(dep) = 600 degrees C as a function of the deposition time and thickness has then been studied with STM-UHV, revealing an initial growth of mosaic-like 3D islands. These independent islands, already interconnected, expand along two orthogonal directions and, for longer deposition times, lead to the texture of orthogonal stripes. The EDXR characterization providing the morphological parameters of the films, i.e., thickness and roughness, confirms the above observation and quantifies the effect of such morphological changes on the surface roughness of the Pt film, an important parameter for applications of Pt films as underlayer in magnetic recording media.     

Enhancement of two-photon absorption cross-section and singlet-oxygen generation in porphyrins upon beta-functionalization with donor-acceptor substituents

The microwave-enhanced synthesis, comparative singlet oxygen sensitization efficiency, and nonlinear optical characterization of a new beta-functionalized porphyrin and its copper complex are described. We show that the introduction of a donor-acceptor push-pull conjugated fragment in the beta position strongly perturbs the porphyrin electronic structure leading to a remarkable one- and two-photon NIR absorption enhancement.     

Structure-activity-based design of a synthetic malaria peptide eliciting sporozoite inhibitory antibodies in a virosomal formulation

The circumsporozoite protein (CSP) of Plasmodium falciparum is a leading candidate antigen for inclusion in a malaria subunit vaccine. We describe here the design of a conformationally constrained synthetic peptide, designated UK-39, which has structural and antigenic similarity to the NPNA-repeat region of native CSP. NMR studies on the antigen support the presence of helical turn-like structures within consecutive NPNA motifs in aqueous solution. Intramuscular delivery of UK-39 to mice and rabbits on the surface of reconstituted influenza virosomes elicited high titers of sporozoite crossreactive antibodies. Influenza virus proteins were crucially important for the immunostimulatory activity of the virosome-based antigen delivery system, as a liposomal formulation of UK-39 was not immunogenic. IgG antibodies elicited by UK-39 inhibited invasion of hepatocytes by P. falciparum sporozoites, but not by antigenically distinct P. yoelii sporozoites. Our approach to optimized virosome-formulated synthetic peptide vaccines should be generally applicable for other infectious and noninfectious diseases.     

A novel LIF-CE method for the separation of hyaluronan- and chondroitin sulfate-derived disaccharides: Application to structural and quantitative analyses of human plasma low- and high-charged chondroitin sulfate isomers

The report describes a rapid and simple CE method using LIF detection for the analysis of unsaturated disaccharides obtained from enzymatic depolymerization of plasma chondroitin sulfate (CS) isomers. The disaccharide reducing groups were labeled with 2-aminoacridone (AMAC). The fluorotagged products can be separated by reversed-polarity CE using a sodium acetate buffer, pH 3.8, in the presence of 0.05% methylcellulose. The choice of the appropriate electrophoretic conditions was performed after a deep analysis of the most important parameters affecting analyte separation. In particular, the effect of both run buffer concentration and pH on resolution, efficiency, migration times, and peak area was evaluated. The selected electrophoretic conditions allowed us to separate the CS isomers-derived Delta-disaccharides in less than 12 min, also resolving the nonsulfated disaccharides released from CS isomers from those released from hyaluronan (HA). Moreover, these conditions gave a good reproducibility of both the migration times (CV%, 0.25) and the peak areas (CV%, 1.4). Intra- and interassay CV were 5.37 and 7.23%, respectively, and analytical recovery was about 86%. The applicability of the above method to the quantitative and structural disaccharide analyses of plasma CS isomers was investigated. Data obtained from 44 healthy human subjects were compared with those obtained by a fluorophore-assisted carbohydrate electrophoresis (FACE) reference assay, by using the Passing and Bablok regression and Bland-Altman tests. The developed method could represent a good tool for an ultrasensitive analysis of CS isomers in biological samples from different sources, particularly when samples are available in very low amounts.     

Recent advances in the benzannulation of substituted 3-alkoxycarbonyl-3,5-hexadienoic acids and 3-alkoxycarbonylhex-3-en-5-ynoic acids to polysubstituted aromatics

The benzannulation reactions of substituted 3-alkoxycarbonyl-3,5-hexadienoic and 3-alkoxycarbonylhex-3-en-5-ynoic acids offer a straightforward access to various polysubstituted aromatic compounds. The process is very flexible, and can be applied to the regiospecific preparation of oligoaryls, naphthalenes, ring-fused heterocycles, chiral tetrahydronaphthalenes, C-aryl-glycosides and many natural products of different structure. In this Concept article, we highlight the potential of this annulation reaction by illustration of our recent contribution to this field, as well as the studies previous reported by others.     

IPG with electrodic plateaus (and other unusual procedures for 2-DE)

We describe some simple changes to the geometry of the IPG strips that make them suitable to the loading of very large sample volumes and of high-salt solutions. Of special relevance is the possibility of using strips with immobilized plateau(s) to either side of the gradient, or to both, also in connection with in-gel rehydration protocols and focusing in stock trays. The only requirement to achieve this is to leave the all-ready-made attitude and go back to custom polymerization of the IPGs in one's laboratory.     

Evaluation of different polymerase chain reaction methods for the identification of Vibrio parahaemolyticus strains isolated by cultural methods

Control of contamination by Vibrio parahaemolyticus in fishery products is often hampered by the lack of standardized methods and by the uncertainty associated with biochemical identification of the isolates. In this study, 5 polymerase chain reaction (PCR) methods for the identification of V. parahaemolyticus to the species level were evaluated by using 25 Vibrio reference strains and 163 isolates from fishery products, environmental sources, and clinical samples. Sequence targets of the methods were toxR, gyrB, and tlh genes (tested with 2 protocols), and the fragment pR72H. Isolate identification was confirmed by sequencing of the 16S rRNA gene and by PCR protocols for the identification of other Vibrio species. The PCR assay targeting the toxR gene achieved the highest performance (100% inclusivity and exclusivity). The 2 PCR protocols based on tlh gene detection, although showing the same inclusivity (100%), differed in the exclusivity (50 and 91%, respectively). Finally, the results provided by the PCR assays targeting the gyrB gene and pR72H fragment were less reliable and, in some cases, difficult to assess. According to the results of this study, the characteristics of accuracy expressed by the toxR identification method make it a suitable candidate as a reference method for the molecular identification of V. parahaemolyticus strains.     

Ozone-based electrochemical advanced oxidation processes

Novel processes have recently been developed that provide for the enhancement of ozonation through combination with electrochemical treatments. These are processes that can be included among those defined as advanced oxidation processes as they proceed via electrogeneration of highly oxidizing radical species.These processes are generally carried out by sparging ozone in both divided and undivided electrochemical cells in order to promote its decomposition through different mechanisms, depending on the electrode materials adopted, and in some cases still debated.This mini review presents the most recent advances in the field of electrochemically assisted ozonation.In particular, the first section is focused on the process known as electroperoxone (EP) where the ozone decomposition is enhanced by the adoption of carbon-based cathodes, due to the electrogeneration of hydrogen peroxide, while the second section is focused on the process that implies ozonation in a cell adopting metal-based cathodes.     

Label-Free Quantitative Proteomics to Explore the Action Mechanism of the Pharmaceutical-Grade Triticum vulgare Extract in Speeding Up Keratinocyte Healing

Plant extracts have shown beneficial properties in terms of skin repair, promoting wound healing through a plethora of mechanisms. In particular, the poly-/oligosaccharidic aqueous extract of Triticum vulgare (TVE), as well as TVE-based products, shows interesting biological assets, hastening wound repair. Indeed, TVE acts in the treatment of tissue regeneration mainly on decubitus and venous leg ulcers. Moreover, on scratched monolayers, TVE prompts HaCat cell migration, correctly modulating the expression of metalloproteases toward a physiological matrix remodeling. Here, using the same HaCat-based in vitro scratch model, the TVE effect has been investigated thanks to an LFQ proteomic analysis of HaCat secretomes and immunoblotting. Indeed, the unbiased TVE effect on secreted proteins has not yet been fully understood, and it could be helpful to obtain a comprehensive picture of its bio-pharmacological profile. It has emerged that TVE treatment induces significant up-regulation of several proteins in the secretome (153 to be exact) whereas only a few were down-regulated (72 to be exact). Interestingly, many of the up-regulated proteins are implicated in promoting wound-healing-related processes, such as modulating cell–cell interaction and communication, cell proliferation and differentiation, and prompting cell adhesion and migration.     

Therapeutic Potential of Highly Selective A3 Adenosine Receptor Ligands in the Central and Peripheral Nervous System

Ligands of the G_i protein-coupled adenosine A₃ receptor (A₃R) are receiving increasing interest as attractive therapeutic tools for the treatment of a number of pathological conditions of the central and peripheral nervous systems (CNS and PNS, respectively). Their safe pharmacological profiles emerging from clinical trials on different pathologies (e.g., rheumatoid arthritis, psoriasis and fatty liver diseases) confer a realistic translational potential to these compounds, thus encouraging the investigation of highly selective agonists and antagonists of A₃R. The present review summarizes information on the effect of latest-generation A₃R ligands, not yet available in commerce, obtained by using different in vitro and in vivo models of various PNS- or CNS-related disorders. This review places particular focus on brain ischemia insults and colitis, where the prototypical A₃R agonist, Cl-IB-MECA, and antagonist, MRS1523, have been used in research studies as reference compounds to explore the effects of latest-generation ligands on this receptor. The advantages and weaknesses of these compounds in terms of therapeutic potential are discussed.