Search results for "tmor"

Kinetic and equilibrium studies for the adsorption of acid nucleic bases onto K10 montmorillonite

2011

Abstract The kinetic of the adsorption of two nucleic acid bases, namely adenine (A) and cytosine (C), on K10 montmorillonite (MMT) clay has been investigated over a wide range of nitrogenous bases concentrations, by using the spectrophotometric method. The measurements have been performed at T = 25.0 °C and pH = 4.0 where adenine and cytosine exist both in their protonated and neutral forms. Preliminary to the kinetic data treatment, the adsorption isotherms have been gathered and, then, analyzed by using the Freundlich and the Dubinin–Radushkevich model. The obtained results allow to draw the conclusion that physisorption of adenine and cytosine on MMT occurs and the process is mainly gov…

Effect of heating of organo-montmorillonites under different atmospheres

2009

Abstract We studied the influence of heating on the behaviour of two organo-montmorillonites paying particular attention to the possible degradation effects of the organic modifier under different atmospheres. Hoffmann elimination and anucleophilic substitution on the nitrogen led to rapid degradation of the modifier. As confirmed by deconvoluted FTIR spectra, the presence of oxygen accelerated the degradation rate. The degradation products of the modifier (α-olefins transforming into various carboxyl compounds if oxygen is present) initially increased the basal spacing, followed by a collapse of the particle layers when the decomposition products migrated toward the surface and eventually …

Photo-stabilization of biopolymers-based nanocomposites with UV-modified layered silicates

2020

Abstract Eco-friendly in-situ stabilised biopolymer nanocomposites based on polyamide 11 (PA11) and polylactic acid (PLA) were prepared by melt mixing in the presence of a modified organo-montmorillonite clay containing a chemically-bound hindered amine UV-stabilising function, [(UV)OM-MMt]. Characterisation of the newly synthesised organo-modifier containing the reactive hindered amine (HAS) UV-stabilising function [(UV)OM] has confirmed a successful synthesis. The (UV)OM was then introduced into NaMMt through ion exchange reaction to prepare the UV stabiliser-bound organo-modified-MMt, [(UV)OM-MMt]. The in-situ stabilised PA11- and PLA- nanocomposites (PA11-(UV)OM-MMt and PLA-(UV)OM-MMt) …

Thermomechanical Characterization of Polylactic Acid and Composites

2018

This paper presents the experimental tests for the thermomechanical characterization of biopolymer polylactic acid, and its composites with beech flour or with nanoreiforcement of modified montmorillonite, in order to evaluate any applicability in the automotive sector. Tests of torque and traction are executed for the mechanical characterization and the results comparison; dynamical tests are executed for the thermomechanical characterization, determining the elastic modulus and loss factor versus the actual temperature.

Caratterizzazione termomeccanica dell’acido polilattico e due suoi compositi

2018

Questa memoria presenta i test sperimentali per la caratterizzazione termomeccanica del biopolimero acido polilattico e dei suoi compositi con farina di faggio o con nanorinforzo di montmorillonite modifcata, per uno studio di applicabilità nel settore automobilistico. Per la caratterizzazione meccanica e il confronto dei risultati vengono eseguiti prove di coppia e di trazione; i test dinamici vengono eseguiti per la caratterizzazione termomeccanica, determinando il modulo elastico e il fattore di perdita rispetto alla temperatura effettiva. This paper presents the experimental tests for the thermomechanical characterization of biopolymer polylactic acid, and its composites with beech flour…

POLYCHLORINATED BIPHENYLS ADSORPTION ONTO ALGINATE BEADS AND HYBRID ALGINATE MONTMORILLONITE BEADS: ISOTHERMAL AND KINETIC STUDIES

2013

Immunohistochemical detection of early myocardial infarction: a systematic review

2017

The postmortem diagnosis of early myocardial infarction is a challenge for forensic pathologists because the routine histology is neither specific. Many authors have suggested the use of the immunohistochemistry to fill the gaps in the histological diagnosis of early myocardial infarction. This review aims to analyse advances of immunohistochemical detection of early cardiac damage due to ischaemia. To this purpose, we reviewed experimental studies that investigated immunohistochemical markers and their estimated timing of expression. The review was performed according to specific inclusion and exclusion criteria, and a total of 23 studies assessing the immunohistochemical markers for the d…

An improved anatomical MRI technique with suppression of fixative fluid artifacts for the investigation of human postmortem brain phantoms

2016

PURPOSE Phantoms are often used to assess MR system stability in multicenter studies. Postmortem brain phantoms best replicate human brain anatomy, allowing for a combined assessment of the MR system and software chain for data analysis. However, a wash-out of fixative fluid affecting T1 values and thus T1-weighted sequences such as magnetization-prepared 180 degrees radiofrequency pulses and rapid gradient-echo (MP-RAGE) has been reported for brain phantoms, hampering their immediate use. The purpose of this study was the creation of anatomical data that provide the characteristics of conventional data while avoiding this artifact. THEORY AND METHODS Two brain phantoms were scanned at seve…

Unexpected postmortem diagnosis of Acanthamoeba meningoencephalitis following allogeneic peripheral blood stem cell transplantation.

2008

Meningoencephalitis caused by pathogenic free-living amebas is usually fatal. Only a few cases of Acanthamoeba meningoencephalitis, diagnosed at autopsy, have been reported following hematopoietic stem cell transplantation. We here report a case of Acanthamoeba meningoencephalitis following allogeneic peripheral blood stem cell transplantation with rapidly evolving neurologic symptoms that remained unexplained. Magnetic resonance imaging failed to show brain lesions and cerebrospinal fluid was negative for microbiological cultures. Definite diagnosis was an unexpected autopsy finding. As overall and teaching hospital autopsy rates are declining worldwide, we must emphasize the need of autop…

Role of clays in protecting adsorbed DNA against X-ray radiation

2004

The X-ray emission of the young Sun was much harder and intense than today and might have played a significant role in the evolution of complex organics in protoplanetary environments. We investigate the effects of soft X-rays on tryptophan molecules in aqueous solutions at room temperature. As results of the irradiation experiments we detect several light species indicative of fragmentation, together with large molecular structures such as tryptophan dipeptide and tripeptide. Complexification is more evident in H2O solution than in D2O, probably due to isotopic effects. The abundances of peptides depend on the irradiation dose and decrease with increasing energy deposition. Radicals such a…