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To realize the benefits of a hydrogen economy, hydrogen must be produced cleanly, efficiently and affordably from renewable resources and, preferentially, close to the end-users. The goal is a sustainable cycle of hydrogen production and use: in the first stage of the cycle, hydrogen is produced from renewable resources and then used to feed a fuel cell. This cycle produces no pollution and no greenhouse gases. In this context, the development of electrolyzers producing high-purity hydrogen with a high efficiency and low cost is of great importance. Electrode materials play a fundamental role in influencing electrolyzer performances; consequently, in recent years considerable efforts have been made to obtain highly efficient and inexpensive catalyst materials. To reach both goals, we have developed electrodes based on Pd–Co alloys to be potentially used in the PEMEL electrolyzer. In fact, the Pd–Co alloy is a valid alternative to Pt for hydrogen evolution. The alloys were electrodeposited using two different types of support: carbon paper, to fabricate a porous structure, and anodic alumina membrane, to obtain regular arrays of nanowires. The goal was to obtain electrodes with very large active surface areas and a small amount of material. The research demonstrates that the electrochemical method is an ideal technique to obtain materials with good performances for the hydrogen evolution reaction. The Pd–Co alloy composition can be controlled by adjusting electrodeposition parameters (bath composition, current density and deposition time). The main results concerning the fabrication process and the characterization are presented and the performance in acid conditions is discussed.

Nowadays, we are assisting in the exceptional growth in research relating to the development of wearable devices for sweat analysis. Sweat is a biofluid that contains useful health information and allows a non-invasive, continuous and comfortable collection. For this reason, it is an excellent biofluid for the detection of different analytes. In this work, electrochemical sensors based on polyaniline thin films deposited on the flexible substrate polyethylene terephthalate coated with indium tin oxide were studied. Polyaniline thin films were abstained by the potentiostatic deposition technique, applying a potential of +2 V vs. SCE for 90 s. To improve the sensor performance, the electronic substrate was modified with reduced graphene oxide, obtained at a constant potential of −0.8 V vs. SCE for 200 s, and then polyaniline thin films were electrodeposited on top of the as-deposited substrate. All samples were characterized by XRD, SEM, EDS, static contact angle and FT-IR/ATR analysis to correlate the physical-chemical features with the performance of the sensors. The obtained electrodes were tested as pH sensors in the range from 2 to 8, showing good behavior, with a sensitivity of 62.3 mV/pH, very close to a Nernstian response, and a reproducibility of 3.8%. Interference tests, in the presence of competing ions, aimed to verify the selectivity, were also performed. Finally, a real sweat sample was collected, and the sweat pH was quantified with both the proposed sensor and a commercial pH meter, showing an excellent concordance.

This paper provides a review of the literature on bullying in school settings. The role of Solution-Focused Brief Therapy (SFBT) is explored as a possible intervention approach. Clear gaps in the literature indicate that further studies are recommended on the effectiveness of SFBT on bullying at schools.

Melatonin-loaded hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) gels were prepared by using freeze-thaw technique and an emulsion method followed by freeze-thaw technique to produce a new synergistic system for topical application. Freeze-thaw hydrogels and emulgels were characterized by means of Fourier transform infrared spectroscopy, rheology and swelling tests. The porous structure of the hydrogels was shown by scanning electron microscopy observations and thermal properties were tested by differential scanning calorimetry measurements. Bioadhesion and in vitro release characterization of formulations were performed by texture profile analysis and dialysis bag method, respectively. The pore size of both formulations was ranging from 900 nm to 30 μm. Melatonin showed a good compatibility with the polymeric matrices as the pores were smaller for the drug-loaded systems. In vitro release studies showed that the release was improved by emulgel formulations. After 24 h, the release percentage was found to be 13.240% ± 1.094 and 15.192% ± 2.270 for hydrogel and emulgel, respectively. Emulgels had better bioadhesion properties than simple freeze-thaw samples. As a conclusion, regarding the in vitro characterization studies HA and PVA hydrogel and emulgel formulations and their lyophilized forms could be promising systems for topical application of melatonin.

Rapid on-site evaluation (ROSE) of endobronchial ultrasound-guided transbronchial needle aspirates (EBUS-TBNA) has not been compared to final detailed cytological analysis in patients with suspected sarcoidosis. To assess the diagnostic accuracy of EBUS-TBNA with ROSE in patients with suspected sarcoidosis, a prospective two-centre study performed EBUS-TBNA with ROSE of cellular material followed by transbronchial lung biopsy (TBLB) and endobronchial biopsy (EBB). The diagnostic accuracy of EBUSTBNA with ROSE was compared to the final cytological assessment and to TBLB and EBB. Analysis confirmed 49 out of 60 cases of sarcoidosis. ROSE sensitivity was 87.8% (specificity 91%, positive predictive value 97.7%). ROSE slide interpretation in combination with the final fixed slide and cell block preparations had a sensitivity of 91.8% (specificity 100%, positive predictive value 100%). 67% of patients were confirmed as having sarcoidosis on TBLB and 29% on EBB. Interobserver agreement between cytotechnologists and pathologists was very good (κ=0.91, 95% CI 0.80-1.0 and κ=0.91, 95% CI 0.79-1.0, respectively). EBUS-TBNA with ROSE has high diagnostic accuracy and interobserver agreement and informs the bronchoscopist in theatre whether additional diagnostic procedures need to be undertaken. EBUS-TBNA with ROSE should therefore be considered as the first-line investigation of sarcoidosis. Copyright

Background Although anal squamous cell carcinomas (ASCC) are rare in the general community, rates of ASCC among HIV-positive men who have sex with men (MSM) approach those of major cancers in the general community, such as colorectal and lung cancers. Anal cytology and high-resolution anoscopy (HRA) have been proposed as methods for the diagnosis of high-grade anal intraepithelial neoplasia (HGAIN), the precursor of ASCC. To determine the prevalence of anal disease among HIV-positive MSM, we investigated anal cytological and histological findings in men from a large HIV clinic in Sydney, Australia. Methods: This was a single-centre study conducted between October 2008 and January 2010. Participants self-collected cytology specimens, and those yielding abnormal cytology results of atypical cells of undetermined significance, atypical cells of undetermined significance – possibly high-grade (ASC-H) and high-grade squamous intraepithelial lesions (HSIL) were offered HRA. In addition, of those yielding low-grade squamous intraepithelial lesions results, a systematically selected group (25%) were offered HRA. Results: Of the 1339 HIV-positive MSM who attended the clinic during the study period, 291 (31.8%) were finally included in the study, 262 yielded technically satisfactory cytological results and 101 (36.7%) participants underwent HRA. HGAIN was identified in 55 (54.5%) of the 101 men undergoing HRA. HGAIN was diagnosed in 28 (52.7%) without cytological ASC-H or HSIL results. Conclusions: Despite the poor correlation between anal cytological and histological findings, high levels of HGAIN were identified in HIV-positive MSM attending this clinical service.

In recent years, the interest towards green hydrogen has drastically increased due to the global decarbonization process. Green hydrogen is obtained by water electrolysis using only electricity from renewable sources. It is considered one of the best storage systems in terms of environmental sustainability but not in economic ones. Nowadays, the research is focused on improving the Alkaline Water Electrolysis (AE) to reduce the cost of production. An approach to improve AE performance is based on nanostructured electrodes characterized by high electrocatalytic activity due to the very high surface area. In fact, the development of more efficient electrolysers with low-cost electrode-electrocatalyst materials can play a key role. The eligible materials must have some fundamental characteristics, such as good electrocatalytic properties, high conductivity, high availability, low cost, and good chemical stability. In alkaline environment it was demonstrated that, transition metals, and in particular Ni nanowires electrodes covered by different electrocatalyst, have good and stable performance. In this work, the attention was focused on the fabrication and characterization of nickel-alloy electrodes for both hydrogen and oxygen evolution reaction. Nanowires of Ni alloys were obtained by template electrosynthesis using polycarbonate membrane. Different alloys (Ni-Co, Ni-Zn, Ni-W and Ni-Fe) at different composition were studied in order to determine the most suitable alloy and its optimum composition. The electrodes have been studied morphologically and chemically through SEM, XRD, and EDS analyses. The composition of Ni-Co alloy appears very complex. It can be observed that the Co content is higher in the alloy than in the electrolyte. The same behavior can be observed in Ni-Fe alloy. In the case of the Ni-Zn alloy, its composition is linear with the composition of the bath. For Ni-W a very different trend was observed. Later, electrodes were tested both as anodes and as cathodes by CV, QSSP, and galvanostatic polarization in 30% w/w KOH solution. For hydrogen evolution reaction, the best alloy was the one rich in Co, followed by the alloy at 50% in Zn and Ni. For oxygen evolution reaction, the best performance was found in Ni-Fe alloy, in particular Fe 78.95. All the electrochemical tests show that nanostructured electrodes have a good chemical and mechanical stability. Preliminary results on the performance of an asymmetric electrolyzer consisting of Ni-Fe, for OER, and Ni-Co, for HER, nanostructured electrodes was also reported.

Thanks to mechanical properties similar human bones, metallic materials represent the best choice for fabrication of orthopedic implants. Although metals could be widely used in the field of biomedical implants, corrosion phenomena could occur, causing metal ions releasing around periprosthetic tissues leading, in the worst cases, to the development of infections. In these cases, patients need prolonged antibiotic therapies that may cause bacterial resistance. Preventing bacterial colonization of biomedical surfaces is the key to limiting the spread of infections. Antibacterial coatings have become a very active field of research, strongly stimulated by the increasing urgency of identifying alternatives to the traditional administration of antibiotics. Nowadays, the research was focused on coating science to deal with these issues. In particular, the development of the antibacterial composite coatings could be a viable way to provide not only a corrosion resistance but also an antibacterial action and biocompatibility. Chitosan is a great biomaterial used in medicine. It is a natural bioactive polymer and is the second most abundant in nature polysaccharide after cellulose. Chitosan comes from the deacetylation of chitin, a homopolymer of beta-(1-4)-N-acetyl-D-glucosamine, derived from exoskeleton of crustaceans. It is high biocompatible and it is also used in drug delivery. In addition, chitosan has chelating properties due to the amino groups of polysaccharide that are responsible of selective chelation with metal ions. In particular, the attention has been paid to silver nanoparticles for their high stability, low toxicity, biocompatibility and antibacterial properties. These ones are incorporated in polymeric matrix (e.g. chitosan) and they are capable to interact physically with cell walls of bacteria. In this study Chitosan-Silver nanoparticles composite coating on AISI 304L was investigated. These coatings were realized by an alternative method of deposition respect to traditional ones based on galvanic coupling. This process doesn’t request any external power supply and is very easy to carried out. The difference of the electrochemical redox potential between the substrate (cathode) and a sacrificial anode is the pivotal role of the process. Deposition rate is controlled by the ratio of cathodic and anodic area. In practice, electrons generated by anode corrosion flow towards to more noble metal thanks to a short-circuit. As soon electrons arrive to the cathode, the base electrogeneration reactions of nitrate ions and water molecules occur. Production of hydroxyl ions causes an increasing of pH at substrate/solution interface. Hence, deprotonation of amine group leads precipitation of chitosan (pKa=6.4) onto surface. At the same time, silver nanoparticles are incorporated in polymeric matrix of chitosan. Physical-chemical characterizations of the coatings were carried out in order to investigate morphology and chemical composition. In addition, corrosion tests (potentiodynamic polarization and electrochemical impedance spectroscopy) were executed in a simulated body fluid to scrutinize the corrosion resistance. Furthermore, the release of silver nanoparticles from coating in SBF were studied.