Microwave-assisted synthesis of N/S-doped CNC/SnO2 nanocomposite as a promising catalyst for oxygen reduction in alkaline media

In this study, we report an all-green approach for the synthesis of novel catalysts for oxygen reduction reaction (ORR) via a simple two-step procedure. In particular, conductive cellulose nanocrystals (CNCs) were obtained via pyrolysis, and a successive microwave-assisted hydrothermal process was employed to activate the carbon lattice by introducing sulfur (S) and nitrogen (N) dopants, and to decorate the surface with tin oxide (SnO2) nanocrystals. The successful synthesis of N/S-doped CNC/SnO2 nanocomposite was confirmed by X-ray Photoelectron Spectroscopy analysis, Energy Dispersive X-ray microanalysis, X-ray Diffraction and Field Emission Scanning Electron Microscopy. The synergistic effects of the dopants and SnO2 nanocrystals in modifying the catalytic performance were proved by various electrochemical characterizations. Particularly, the nanocomposite material reaches remarkable catalytic performance towards the ORR, close to the Pt/C benchmark, in alkaline environviment, showing promising potential to be implemented in alkaline fuel cell and metal-air battery applications

Tin sulfide supported on cellulose nanocrystals-derived carbon as a green and effective catalyst for CO2 electroreduction to formate

This work reports a whole green two-step approach for the synthesis of novel catalysts for efficient CO2 conversion. A conductive carbon support was firstly obtained via pyrolysis of cellulose nanocrystals (CNCs), and the carbon surface was successively decorated with tin sulfide (SnS) through a microwave-assisted hydrothermal process. The morphology and carbon structure were characterized by field emission scanning electron microscopy and Raman spectroscopy, and the presence of SnS decoration was confirmed by X-ray photoelectron spectroscopy and X-ray diffraction analyses. The SnS supported on CNC-derived carbon shows enhanced catalytic activity for the CO2 conversion to formate (HCOO-). Good selectivity of 86% and high partial current density of 55 mA cm(-2) are reached at - 1.0 V vs. reversible hydrogen electrode in KHCO3 electrolyte. Additionally, the mass activity of the composite catalyst achieves a value as high as 262.9 mA mgSn(-1) for HCOO- formation, demonstrating good utilization efficiency of Sn metal. In this work, the low-cost CNC-derived carbon is evidenced to be easily decorated with metal species and thus shows high versatility and tailorability. Incorporating metal species with conductive high-surface carbon supports represents an effective strategy to realize active and stable electrocatalysts, allowing efficient utilization of metals especially the raw and precious ones

Tuberculosis in cattle slaughtered in the intermediate geographic region of Caicó, State of Rioi Grande do Norte, Brazil.

The bovine farming constitutes an economic and social activity of great importance for the State of Rio Grande do Norte, contributing for the creation of jobs and generation of income. However, factors related to the low technification of the activity on the part of the producers, the occurrence of a wide and intense drought in the last years and the presence of infectious diseases have caused significant damages to the breeders of animals in the State. Infectious diseases include tuberculosis, which is a zoonotic infection caused by Mycobacterium bovis, the primary host of which is cattle, but several domestic and wild mammal species, including humans, are also susceptible. The objective of the study was to determine the occurrence of tuberculosis in bovine slaughtered in two public slaughterhouses of the intermediate geographic region of Caicó, State of Rio Grande do Norte. Between November 2017 and August 2018, a total of 11,616 bovine carcasses underwent routine post-mortem inspection, with lesions suggestive of tuberculosis in one animal (0.009%). Samples of tissues located in the lung, heart and spleen were submitted to bacteriological culture and molecular diagnosis

Microwave-assisted methacrylation of chitosan for 3D printable hydrogels in tissue engineering

Light processable natural polymers are highly attractive for 3D printing of biomedical hydrogels with defined geometries and sizes. However, functionalization with photo-curable groups, such as methacrylate or acrylate groups, is required. Here, we investigated a microwave-assisted process for methacrylation of chitosan to replace conventional methacrylation processes that can be time consuming and tedious. The microwave-assisted methacrylation reaction was optimized by varying the synthesis parameters such as the molar ratio of chitosan to the methacrylic agent, the launch and reaction times and process temperature. The optimized process was fast and efficient and allowed tuning of the degree of substitution and thereby the final hydrogel properties. The successful methacrylation and degree of substitution were verified by H-1 NMR and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The influence of the degree of methacrylation on photo-rheology, mechanical stiffness, swelling degree and gel content was evaluated. Furthermore, favourable 3D printability, enzymatic degradability, biocompatibility, cell migration and proliferation were demonstrated giving promise for further applications in tissue engineering

Mobile Daily Centre (Mdc) for Elder People with Cognitive Impairment: a Retrospective Observational Study

Introduction Trieste is a city characterized by a high mean age of the resident population, with 6,000 people with a cognitive impairment. Evidences show that is necessary to have a multidisciplinary approach, making alliances with the social network and families, while dealing with people with cognitive impairment. Because of this, the 3rd catchment district has developed a Mobile Daily Centre that aims to promote health, abilities and socialization giving the possibilities for these people to stay in a social context. Objectives Evaluating the impact of the Mobile Daily Centre on QoL of people with Cognitive Impairment. Aims Considering the rate of hospitalization and access to the first aid unit at the general hospital. Methods Retrospective Observational Study for the period between 01.01.2012 and 30.04.2014 on people in charge to the MDC. We have considered socio-demographic variables such as age, gender, care-givers; clinical variables such as psychopharmacotherapy and acetylcolinesterase-inhibitors drugs; rates of hospitalization, number of accesses to the first aid unit and of interventions of the MDC. Results in the period of the study 20 patients have been followed by the MDC; half of them had a psycho-pharmacological prescription. Very low rates of institutionalization have been detected. Conclusions MDC, in these small numbers, has shown to reduce the number of improper institutionalizations while guaranteeing to the elder people to maintain their abilities and socialization and to their care-givers periods of relief. Moreover, it promotes social inclusion and destigmatization. These results suggest that more territorial work and further studies should be done

Preparation of bio-functional textiles by surface functionalization of cellulose fabrics with caffeine loaded nanoparticles

In recent years transdermal drug delivery has aroused significant interest as a sustained and non-invasive way of administering active substances. The development of nanotechnology allowed the development of novel pharmaceutical formulations overcoming skin barrier. Furthermore, such nano-system can be combined with conventional fabrics to pave the way to a new generation of wearable drug delivery devices: bio-functional garments. First the NP were produced by flash nanoprecipitation technique (FNP), the production process was optimized to produce particles with suitable size for transdermal applications. The nanoparticles were characterized in terms of drug content by UV-visible spectroscopy and in terms of antioxidant activity by Electron Paramagnetic Resonance spectroscopy (EPR) coupled with spin trapping technique. The NPs were used to functionalize cotton and viscose-micromodal fabrics and the transdermal release properties were tested in vitro by Franz’s Cell experiment. FNP was proven to be an effective technique to produce tunable size particles. Moreover, the nanoencapsulated drug exhibited antioxidant activity. The release test evidenced a controlled release behavior effect providing evidence that the bio-functional textile is suitable for applications where sustained release and antioxidant properties are required