Recent progress in the synthesis of nanostructured magnesium hydroxide

This review highlights synthetic routes for producing nanostructured magnesium hydroxide and focuses on how these various preparative approaches can produce Mg(OH)2 nanoparticles with controlled size and morphology. Mg(OH)2 nanocrystals with rod-, needle-, hollow tube- or platelet-like morphology can be synthesised by the modification of chemical and physical experimental parameters such as the selection of magnesium precursor, solvent and temperature or by employing surface modifiers and templates. Techniques based on hydrothermal/solvothermal treatments, microwave heating and (co-)precipitation are dominant in the production of Mg(OH)2 at the nanoscale, but other materials design approaches are now emerging. Bulk Mg(OH)2 has been extensively studied over decades and finds use in a wide range of applications. Moreover, the hydroxide can also serve as a precursor for other commercially important materials such as MgO. Nanostructuring the material has proven extremely useful in modifying some of its most important properties – not least enhancing the performance of Mg(OH)2 as a non-toxic flame retardant – but equally it is creating new avenues of applied research. We evaluate herein the latest efforts to design novel synthesis routes to nano-Mg(OH)2, to understand the mechanisms of crystallite growth and to tailor microstructure towards specific properties and applications

Lightweight metal hydride – hydroxide systems for solid state hydrogen storage

This thesis describes the preparation and characterisation of potential ‘modular’ solid state hydrogen storage solutions for on-board applications. The systems investigated throughout this work are based on reactions between light weight hydroxides and hydrides. In many senses light metal hydroxides can be seen as attractive candidates for hydrogen storage: they are low cost, present negligible toxicity and it is not possible to poison the fuel cell with decomposition products, unlike in nitrogen or boron containing systems. However, as the dehydrogenation products are the respective oxides, the major drawback of such systems lays in the fact the thermodynamics of rehydrogenation are not favourable for onboard applications. Hence, the system must be considered as a ‘charged module’, where the regeneration is performed ex-situ. Dehydrogenation can be achieved through reaction with light metal hydrides such as LiH or MgH2. A wide range of ‘modular’ release systems can be studied, however the most interesting in terms of theoretical gravimetric capacity, kinetics and thermodynamics within reasonable temperature range (RT - 350°C) use magnesium and lithium hydroxide and their hydrate forms. The present work focuses on the full investigation of three main systems: · Mg(OH)2 – MgH2 system · Mg(OH)2 – LiH system · LiOH(·H2O) – MgH2 system (both anhydrous and monohydrate LiOH were used) Mixtures of hydroxides and hydrides were prepared by manually grinding stoichiometric amounts of the starting materials. Further, nanostructuring the reactants was investigated as a means to control the dehydrogenation reaction and enhance the kinetics and thermodynamics of the process. Nanostructured Mg(OH)2 and LiOH(·H2O) have been successfully obtained using both novel and conventional synthetic routes. Reduction of the particle size of both hydrides was effectively achieved by mechanically milling the bulk materials. As detailed throughout Chapters 3, 4 and 5, promising results were obtained when employing nanosized reactants. The onset temperatures of hydrogen release were decreased and the overall systems performances enhanced. Particularly interesting results were obtained for the LiOH – MgH2 system, which exhibit a dramatic decrease of the onset temperature of H2 release of nearly 100 K when working with milled and nanostructured materials with respect to bulk reagents. All systems were characterised mainly by Powder X-ray diffraction (PXD) and simultaneous thermogravimetric analysis (TG-DTA) mass spectroscopy (MS). TG-DTA2 MS experiments were performed to obtain information on the onset and peak temperature of hydrogen release, weight loss percentage and nature and amount of the gases evolved during the reaction. Ex-situ PXD studies have been performed for each system in order to try and identify any intermediate species forming during the dehydrogenation process and ultimately propose a mechanism of H2 release. Since two fundamentally different types of reaction pathway could be proposed for the Mg(OH)2 – LiH system, powder neutron diffraction (PND) was employed for following the reaction in-situ. Developing a complete model of the dehydrogenation process in terms of mechanistic steps was found to be pivotal in order to understand and enhance such systems further

Rapid surfactant-free synthesis of Mg(OH)2 nanoplates and pseudomorphic dehydration to MgO

Magnesium hydroxide nanoplates ca. 50 nm in thickness can be prepared over minute timescales via hydrothermal synthesis in a multimode cavity (MMC) microwave reactor. This approach allows ca. 1 g of single-phase Mg(OH)2 to be synthesised in under 3 minutes without the requirement of surfactants or non-aqueous solvents. The hydroxide nanomaterial dehydrates at temperatures >200 K below that of the equivalent bulk material and can be utilised as a precursor for the pseudomorphic synthesis of nanoplates of MgO as investigated by TG-DTA-MS, XRD and SEM measurements. Equally, the pseudomorphic synthesis can be performed by irradiating the Mg(OH)2 nanomaterial with microwaves for 6 minutes to produce single phase MgO

COVID-19, AIR POLLUTION AND MENTAL ILLNESS: HEADS OF THE SAME "BEAST"?

The Covid-19 outbreak are generating relevant consequences under several aspects. Covid-19 pandemic together with air pollution and a dysfunctional anthropization/urbanization might affect public and mental health with a synergistic effect. The current paper explore hypothesis about existing links among Covid-19, air pollution and mental illness

COVID-19, AIR POLLUTION AND MENTAL ILLNESS: HEADS OF THE SAME "BEAST"?

The Covid-19 outbreak are generating relevant consequences under several aspects. Covid-19 pandemic together with air pollution and a dysfunctional anthropization/urbanization might affect public and mental health with a synergistic effect. The current paper explore hypothesis about existing links among Covid-19, air pollution and mental illness

Laparoscopic versus open rectal resection. a 1:2 propensity score-matched analysis of oncological adequateness, short- and long-term outcomes

Laparoscopic resections for rectal cancer are routinely performed in high-volume centres. Despite short-term advantages have been demonstrated, the oncological outcomes are still debated. The aim of this study was to compare the oncological adequateness of the surgical specimen and the long-term outcomes between open (ORR) and laparoscopic (LRR) rectal resections

Rapid surfactant-free synthesis of Mg(OH)2 nanoplates and pseudomorphic dehydration to MgO

Magnesium hydroxide nanoplates ca. 50 nm in thickness can be prepared over minute timescales via hydrothermal synthesis in a multimode cavity (MMC) microwave reactor. This approach allows ca. 1 g of single-phase Mg(OH)2 to be synthesised in under 3 minutes without the requirement of surfactants or non-aqueous solvents. The hydroxide nanomaterial dehydrates at temperatures >200 K below that of the equivalent bulk material and can be utilised as a precursor for the pseudomorphic synthesis of nanoplates of MgO as investigated by TG-DTA-MS, XRD and SEM measurements. Equally, the pseudomorphic synthesis can be performed by irradiating the MgIJOH)2 nanomaterial with microwaves for 6 minutes to produce single-phase MgO.JRC.F.2-Energy Conversion and Storage Technologie

ADHD Follow-Up in Adulthood among Subjects Treated for the Disorder in a Child and Adolescent Mental Health Service from 1995 to 2015

Background and Objectives: ADHD is a neurodevelopmental disorder characterized by inattention and hyperactivity/impulsivity and can persist in adulthood. The aim of this study is to deepen knowledge about adult ADHD follow-up. Materials and Methods: This observational study consists of one retrospective part aimed at collecting records of children and adolescents treated for ADHD in the Children and Adolescent Mental Health Service (CAMHS) from 1995 to 2015 and, successively, at identifying their adult follow-up in Adult Mental Health Service (AMHS); the second part consists of ADHD scale administration, Diagnostic Interview for ADHD in Adults (DIVA 2-0) and Adult Self Rating Scale (ASRSv1.1), for the subjects currently being treated at AMHS who agreed to participate in the study. Results: We observed that among the 55 patients treated at CAMHS between 1995 and 2015 for ADHD and subsequently at the AMHS, none presented a diagnosis of ADHD; instead, they were treated for Intellectual Dysfunction (33%), Borderline Personality Disorder (15%) and Anxiety Disorders (9%), and two individuals were also diagnosed with comorbid substance/alcohol abuse (4%). Of the 55 patients, only 25 (45%) were treated at AMHS during the study period. Though we asked for their informed consent to administer the questionnaires, we were able to test only seven patients. The ASRS-V1.1 score showed that 43% of patients reported symptoms of ADHD persistence in adulthood. For DIVA 2.0, 57% of individuals reported scores indicating the persistence of the ADHD inattention component, and 43% the persistence of both ADHD dimensions. Conclusions: ADHD cannot be considered a disorder confined to childhood/adolescence but instead is a chronic and complex condition that can persist into adulthood. The very small size of our final sample may account for both the high ADHD dropout rate over the long follow-up period and the difficult transition from child to adult health care in ADHD treatment. Our investigation suggests the need for specific training in the diagnosis and treatment of adult ADHD and the implementation of transition protocols between minor and adult services to improve long-term treatments

dose administration maneuvers and patient care in tobramycin dry powder inhalation therapy

Abstract The purpose of this work was to study a new dry powder inhaler (DPI) of tobramycin capable to simplify the dose administration maneuvers to maximize the cystic fibrosis (CF) patient care in antibiotic inhalation therapy. For the purpose, tobramycin/sodium stearate powder (TobraPS) having a high drug content, was produced by spray drying, characterized and the aerodynamic behavior was investigated in vitro using different RS01 DPI inhalers. The aerosols produced with 28, 56 or 112 mg of tobramycin in TobraPS powder using capsules size #3, #2 or #0 showed that there was quasi linear relationship between the amount loaded in the device and the FPD. An in vivo study in healthy human volunteers showed that 3–6 inhalation acts were requested by the volunteers to inhale 120 mg of TobraPS powder loaded in a size #0 capsule aerosolized with a prototype RS01 device, according to their capability to inhale. The amount of powder emitted at 4 kPa pressure drop at constant air flow well correlated with the in vivo emission at dynamic flow, when the same volume of air passed through the device. The novel approach for the administration of 112 mg of tobramycin in one capsule could improve the convenience and adherence of the CF patient to the antibiotic therapy

Polymeric Films Loaded with Vitamin E and Aloe vera

Burns are serious traumas related to skin damage, causing extreme pain and possibly death. Natural drugs such as Aloe vera and vitamin E have been demonstrated to be beneficial in formulations for wound healing. The aim of this work is to develop and evaluate polymeric films containing Aloe vera and vitamin E to treat wounds caused by burns. Polymeric films containing different quantities of sodium alginate and polyvinyl alcohol (PVA) were characterized for their mechanical properties and drug release. The polymeric films, which were produced, were thin, flexible, resistant, and suitable for application on damaged skin, such as in burn wounds. Around 30% of vitamin E acetate was released from the polymeric films within 12 hours. The in vivo experiments with tape stripping indicated an effective accumulation in the stratum corneum when compared to a commercial cream containing the same quantity of vitamin E acetate. Vitamin E acetate was found in higher quantities in the deep layers of the stratum corneum when the film formulation was applied. The results obtained show that the bioadhesive films containing vitamin E acetate and Aloe vera could be an innovative therapeutic system for the treatment of burns