Novel polymeric photoinitiators bearing side-chain α-aminoacetophenone moieties for ultraviolet-curable pigmented coatings

New polymeric photoinitiators with pendant α-aminoacetophenone moieties, such as the homopolymers of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminopropan-1-one and of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminobutan-1-one have been prepared and fully characterized. Their photoinitiation activity has been also checked in the ultraviolet cure of a standard acrylic mixture, under irradiation over 380 nm, thus simulating the absorption conditions of a TiO₂-pigmented coating formulation. The results have been compared with those found by using the corresponding low-molecular-weight structural models, purposely synthesized. The activity data obtained are discussed and related to the structural requirements of the above systems. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2237–2246, 1997     

Copolymeric systems bearing side-chain thioxanthone and α-aminoacetophenone moieties as photoinitiators for ultraviolet-curable pigmented coatings

Copolymers of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-meth-acryloyloxy propyl)]aminopropan-1-one and of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminobutan-1-one with 1-[(2-methacryloyloxy)ethoxycarbonyl]thioxanthone were prepared and structurally characterized. The above systems were also checked in the ultraviolet cure of an acrylic mixture upon irradiation over 380 nm, thus simulating the conditions of a TiO₂-pigmented formulation. The curing results were compared with those obtained in the presence of the mixtures of the corresponding homopolymers as well as of their low-molecular-weight models. The copolymeric systems display synergistic effects of activity with respect to the structural models but show lower photoinitiation efficiency against the homopolymers mixtures. These data are discussed and interpreted in terms of structural requirements and photochemical mechanistic aspects of the above systems. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2247–2258, 1997     

Dimerization of Human Angiogenin and of Variants Involved in Neurodegenerative Diseases

Human Angiogenin (hANG, or ANG, 14.1 kDa) promotes vessel formation and is also called RNase 5 because it is included in the pancreatic-type ribonuclease (pt-RNase) super-family. Although low, its ribonucleolytic activity is crucial for angiogenesis in tumor tissues but also in the physiological development of the Central Nervous System (CNS) neuronal progenitors. Nevertheless, some ANG variants are involved in both neurodegenerative Parkinson disease (PD) and Amyotrophic Lateral Sclerosis (ALS). Notably, some pt-RNases acquire new biological functions upon oligomerization. Considering neurodegenerative diseases correlation with massive protein aggregation, we analyzed the aggregation propensity of ANG and of three of its pathogenic variants, namely H13A, S28N, and R121C. We found no massive aggregation, but wt-ANG, as well as S28N and R121C variants, can form an enzymatically active dimer, which is called ANG-D. By contrast, the enzymatically inactive H13A-ANG does not dimerize. Corroborated by a specific cross-linking analysis and by the behavior of H13A-ANG that in turn lacks one of the two His active site residues necessary for pt-RNases to self-associate through the three-dimensional domain swapping (3D-DS), we demonstrate that ANG actually dimerizes through 3D-DS. Then, we deduce by size exclusion chromatography (SEC) and modeling that ANG-D forms through the swapping of ANG N-termini. In light of these novelties, we can expect future investigations to unveil other ANG determinants possibly related with the onset and/or development of neurodegenerative pathologies.     

Microbial oxidation of naphthalene to cis-1,2-dihydroxy-1,2-dihydronaphthalene in a membrane bioreactor

A microbial dihydroxylation process for the production of cis-1,2-dihydroxy-1,2-dihydronaphthalene from naphthalene is reported. The oxidation reaction was initially studied in a stirred tank reactor using resting cells of a Pseudomonas fluorescens mutant, grown on glucose as carbon source and acetyl salicylate as inducer of the naphthalene dioxygenase enzymatic system. In these conditions the productivity of the system was limited by the efficiency of the oxygenation and by a reversible product inhibition phenomenon. In order to overcome the inhibitory effect of the 1,2-dihydrodiol accumulation, the biotransformations were carried out in a stirred reactor equipped with a membrane ultrafiltration device. In this way, the cells and the insoluble naphthalene were retained and recycled into the vessel, while the soluble diol was continuously removed through the membrane permeate. The diol was recovered by selective adsorption on a column packed with an adsorbent resin, allowing the rapid and direct recycle of the reaction medium back to the enzymatic reactor. This system afforded a final yield three-fold higher than that of the batch process, exhibiting a bioconversion rate of 1·3 g h⁻¹ dm⁻³ for more than 16 h of continuous working.     

Interfacial adhesion between embedded fibre optic sensors and epoxy matrix in composites

Fibre optic (FO) sensors are becoming increasingly popular for different applications in structural monitoring. Among their excellent properties, a strong interest for this type of sensors are represented by the possibility of embedding FOs inside composite components. In this case, one of the factors that significantly influence the efficiency of the whole Structural Health Monitoring (SHM) system is the interfacial adhesion between FO sensors and the host material. The main objective of this work is to investigate the interfacial adhesion between embedded fibre optic sensors and epoxy matrix to find the best type of optical fibre to be used in epoxy matrices to produce smart composites. Four types of optical fibres with different diameters and coatings (i.e. polyimide, polyacrylate and ormoceramic) were used. Pull-out tests were carried out and different methods were used to obtain the composite/optical fibre interfacial properties. Finally, an optical microscopy and Scanning Electron Microscopy (SEM) analysis were performed to characterize the fibre/matrix interfaces. It was found that the optical fibre that presented the highest energy required for interface rupture and, consequently, less invasiveness to the host material was the ormoceramic fibre with the smallest diameter.     

An experimental characterization of human torso motion

The torso plays an important role in the human-like operation of humanoids. In this paper, a method is proposed to analyze the behavior of the human torso by using inertial and magnetic sensing tools. Experiments are conducted to characterize the motion performance of the human torso during daily routine operations. Furthermore, the forces acting on the human body during these operations are evaluated to design and validate the performance of a humanoid robot.     

Mesothelioma and Colorectal Cancer: Report of Four Cases with Synchronous and Metachronous Presentation

There is evidence that asbestos could play a role in the carcinogenesis of digestive cancers. The presence of asbestos fibres in histological samples from gastric, biliary, colon cancers has been reported, but the mechanism is still controversial. It has been hypothesised that asbestos reaches these sites, especially through contaminated water; however, some experimental studies have shown that the inhaled fibres are mobile, so they can migrate to many organs, directly or via blood and lymph flow. We report four unusual cases of colorectal cancers in patients with a long history of asbestos exposure who also developed synchronous or metachronous mesothelioma. We evaluated the roles of BRCA associated protein-1 (BAP1) and cyclin-dependent kinase inhibitor 2A (CDKN2A) in colon cancer and mesothelioma to support the hypothesis that BAP-1 and CDKN2A are tumour suppressor genes involved in disease progression, recurrence, or death in both digestive cancers and mesothelioma. Potentially, these markers may be used as predictors of worse prognosis, but we also stress the importance of clinical surveillance of exposed patients because asbestos could induce cancer in any organ.     

Molecular Fingerprint of BMD Patients Lacking a Portion in the Rod Domain of Dystrophin

BMD is characterized by a marked heterogeneity of gene mutations resulting in many abnormal dystrophin proteins with different expression and residual functions. The smaller dystrophin molecules lacking a portion around exon 48 of the rod domain, named the D8 region, are related to milder phenotypes. The study aimed to determine which proteins might contribute to preserving muscle function in these patients. Patients were subdivided, based on the absence or presence of deletions in the D8 region, into two groups, BMD1 and BMD2. Muscle extracts were analyzed by 2-D DIGE, label-free LC-ESI-MS/MS, and Ingenuity pathway analysis (IPA). Increased levels of proteins typical of fast fibers and of proteins involved in the sarcomere reorganization characterize BMD2. IPA of proteomics datasets indicated in BMD2 prevalence of glycolysis and gluconeogenesis and a correct flux through the TCA cycle enabling them to maintain both metabolism and epithelial adherens junction. A 2-D DIGE analysis revealed an increase of acetylated proteoforms of moonlighting proteins aldolase, enolase, and glyceraldehyde-3-phosphate dehydrogenase that can target the nucleus promoting stem cell recruitment and muscle regeneration. In BMD2, immunoblotting indicated higher levels of myogenin and lower levels of PAX7 and SIRT1/2 associated with a set of proteins identified by proteomics as involved in muscle homeostasis maintenance.