52 research outputs found
The oxypropylation of olive stone and the use of the ensuing polyols for the synthesis of novel polyesters and polyurethanes based on renewable resources
The development of polyols by the oxypropylation of
abundant and renewable vegetable and animal resources
constitutes an original approach to the exploitation of the
biomass. Cellulose, starch, chitosan, chitin, different types
of lignins, cork and more complex structures like sugar
beet pulp, are among the documented examples. All these
systems displayed a similar pattern in terms of the grafting
of short poly(propylene oxide) (POP) chains from the OH
groups of the substrate, albeit of course each situation
required a specific set of optimized experimental
conditions to transform the natural solid into a viscous
polyol. The transformation of these polyols into
polyurethanes is the only operation which has been studied
to date as a form of their exploitation into polymer
materials. In this work, the more promissing
were selected for chemical modifications involving first
ester and urethane formations with aliphatic and aromatic
monofunctional reagents.FCT within the project PTDC/CTM/71491/200
The oxypropylation of olive stone and the use of the ensuing polyols for the synthesis of novel polyesters and polyurethanes based on renewable resources
The development of polyols by the oxypropylation of abundant and renewable vegetable and animal resources constitutes an original approach to the exploitation of the biomass. Cellulose, starch, chitosan, chitin, different types of lignins, cork and more complex structures like sugar beet pulp, are among the documented examples. All these systems displayed a similar pattern in terms of the grafting of short poly(propylene oxide) (POP) chains from the OH groups of the substrate, albeit of course each situation required a specific set of optimized experimental conditions to transform the natural solid into a viscous polyol. The transformation of these polyols into polyurethanes is the only operation which has been studied to date as a form of their exploitation into polymer materials. In this work, the more promissing promising polyols were selected for chemical modifications involving first ester and urethane formations with aliphatic and aromatic monofunctional reagents.FCT within the project PTDC/CTM/71491/200
Olive stone as a renewable source of biopolyols
The purpose of this work was to establish the feasibility of converting the olive stone residue by means of both total and partial oxypropylation. In the first case, the oxypropylation reaction conditions are chosen in order to promote extensive grafting, thus assuring a complete “liquefaction” of the material and, in the second case, partial oxypropylation would limit the reaction to the outer shell in view of the preparation of all-“olive stone” composites. This approach involves a straightforward transformation of the olive stone particles outer layer, giving rise to a thermoplastic matrix around its unreacted reinforcing inner structure, as already applied to cellulose and starch. To the best of our knowledge, oxypropylation was never applied to olive-stone.FCT (project PTDC/CTM/71491/2006
New polyurethanes from oxypropylated olive stone
The purpose of this work is to explore the possibility of chemically modifying the generated polyols (oxypropylated olive stone) through reactions with isocyanates to produce polyurethanes, other than rigid polyurethane foams. This could be achieved by the chemical modification of the oxypropylation products (condensation with isocyanates) by using mono and difunctional reagents to modulate properties and/or produce useful polymer networks.FCT (project PTDC/CTM/71491/2006_FCOM-
01-0124-FEDER-007156
Search for novel biobased materials within the OLIVPOL project
Within the context of the project OLIVPOL, olive stone (OS) residue was successfully converted into viscous polyols, as such, or containing reinforcing stone cores, by total or partial oxypropylation, respectively. Moreover, the synthesis of new macromolecular materials using the oxypropylated products, such as polyesters and polyurethanes, demonstrated a promising approach to the production of original value-added products based on renewable resources.FCT (Project PTDC/CTM/71491/2006_FCOM-01-0124-FEDER-007156
Diode laser-assisted surgical therapy for early treatment of oral mucocele in a newborn patient : case report and procedures checklist
Mucocele (also known as ranula or salivary gland mucous cyst) of the newborn is a lesion present on the intraoral cavity, with the potential to interfere with respiration and feeding. In the present report, a case of mucocele in a 4-month female patient has been described. As conventional surgery can be followed by several complications such as intraoperative bleeding, difficulties in wound healing, and maintenance of sterility during surgery, in the present case, the use of diode laser has been planned. A topic anesthesia with lidocaine gel was performed. A diode laser (810 nm wavelength, continuous wave mode, power output of 3 watt, and 0.4 mm diameter fiber optic) was set for excising the lesion. The tip was directed at an angle of 10 to 15\ub0, moving around the base of the lesion with a circular motion. The procedure was completed in 3 minutes. The patient was visited with a follow-up of 2 weeks and 4 months after excision. The intraoral wound healed without complications, and no signs of infection or mass recurrence were noted. The histopathological examination confirmed the diagnosis of mucocele. On the basis of the results of the present case report, the use of diode laser can be easily performed also in a noncompliant newborn patient for successful excision of mucocele lesions, and checklist of clinical procedures has been described
Expanding the phenotype associated to KMT2A variants: overlapping clinical signs between Wiedemann–Steiner and Rubinstein–Taybi syndromes
Lysine-specific methyltransferase 2A (KMT2A) is responsible for methylation of histone H3 (K4H3me) and contributes to chromatin remodeling, acting as \u201cwriter\u201d of the epigenetic machinery. Mutations in KMT2A were first reported in Wiedemann\u2013Steiner syndrome (WDSTS). More recently, KMT2A variants have been described in probands with a specific clinical diagnosis comprised in the so-called chromatinopathies. Such conditions, including WDSTS, are a group of overlapping disorders caused by mutations in genes coding for the epigenetic machinery. Among them, Rubinstein\u2013Taybi syndrome (RSTS) is mainly caused by heterozygous pathogenic variants in CREBBP or EP300. In this work, we used next generation sequencing (either by custom-made panel or by whole exome) to identify alternative causative genes in individuals with a RSTS-like phenotype negative to CREBBP and EP300 mutational screening. In six patients we identified different novel unreported variants in KMT2A gene. The identified variants are de novo in at least four out of six tested individuals and all of them display some typical RSTS phenotypic features but also WDSTS specific signs. This study reinforces the concept that germline variants affecting the epigenetic machinery lead to a shared molecular effect (alteration of the chromatin state) determining superimposable clinical conditions
Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project
Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods. Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer dev
2-vinyltetrahydrofuran: characterization and preliminary studies of its polymerisability
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