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Arsenic in drinking water is one of the most concerning problems nowadays due to its high toxicity. The aim of this work is the photocatalytic oxidation of As(III) to As(V) under visible light. This study is focused on the use of gadolinium-doped bismuth ferrite as a photocatalyst active under visible light. Different gadolinium amounts were evaluated (0, 0.5, 1, 2, 5, 10 mol%), and 2 mol% resulted in the best gadolinium amount to reach higher photocatalytic efficiency in terms of As(V) production. The samples were thoroughly characterized in their optical, structural, and morphological properties. The results allowed us to identify an optimal concentration of gadolinium equal to 2 mol%. The reactive oxygen species most responsible for the photocatalytic mechanism, evaluated through the addition of radical scavengers, were O2−● and e−. Finally, a photocatalytic test was performed with a drinking water sample polluted by As(III), showing photocatalytic performance similar to distilled water. Therefore, gadolinium-doped bismuth ferrite can be considered an efficient catalytic material for the oxidation of As(III) to As(V) under visible light. [ABSTRACT FROM AUTHOR]

For the first time, Fe-doping (0.05, 1.0, and 2.5 wt.% Fe) was performed on a high-surface-area anatase/brookite TiO2 by adopting a simple template-free sol-gel synthesis followed by calcination at a mild temperature. The powders' textural and surface properties were characterized by following a multi-technique approach. XRD analysis showed that the anatase/brookite ratio slightly varied in the Fe-doped TiO2 (from 76.9/23.1 to 79.3/22.7); Fe doping noticeably affected the cell volume of the brookite phase, which decreased, likely due to Fe3+ ions occupying interstitial positions, and retarded the crystallite growth. N2 sorption at −196 °C showed the occurrence of samples with disordered interparticle mesopores, with an increase in the specific surface area from 236 m2 g−1 (undoped TiO2) to 263 m2 g−1 (2.5 wt.% Fe). Diffuse Reflectance UV-Vis spectroscopy showed a progressive decrease in the bandgap energy from 3.10 eV (undoped TiO2) to 2.85 eV (2.5 wt.% Fe). XPS analysis showed the presence of some surface Fe species only at 2.5 wt.% Fe, and accordingly, the ζ-potential measurements showed small changes in the pH at the isoelectric point. The photocatalytic degradation of simazine (a persistent water contaminant) both under UV and simulated solar light was performed as a probe reaction. Under UV light, Fe-doping improved simazine degradation in the sample at 0.05 wt.% Fe, capable of degrading ca. 77% simazine. Interestingly, the undoped TiO2 was also active both under UV and 1 SUN. This is likely due to the occurrence of anatase/brookite heterojunctions, which help stabilize the photogenerated electrons/holes. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of the emerging contaminant paracetamol in aqueous solution has been studied under 1 SUN (~1000 W m−2) in the presence of four commercial TiO2 powders, namely sub-micrometric anatase and rutile, and nanometric brookite and P25 (the popular anatase/rutile mixture used as a benchmark in most papers). The rutile powder showed low activity, whereas, interestingly, the anatase and the brookite powders outperformed P25 in terms of total paracetamol conversion to carboxylic acids, which, according to the literature, are the final products of its degradation. To explain such results, the physicochemical properties of the powders were studied by applying a multi-technique approach. Among the physicochemical properties usually affecting the photocatalytic performance of TiO2, the presence of some surface impurities likely deriving from K3PO4 (used as crystallization agent) was found to significantly affect the percentage of paracetamol degradation obtained with the sub-micrometric anatase powder. To confirm the role of phosphate, a sample of anatase, obtained by a lab synthesis procedure and having a "clean" surface, was used as a control, though characterized by nanometric particles and higher surface area. The sample was less active than the commercial anatase, but it was more active after impregnation with K3PO4. Conversely, the presence of Cl at the surface of the rutile did not sizably affect the (overall poor) photocatalytic activity of the powder. The remarkable photocatalytic activity of the brookite nanometric powder was ascribed to a combination of several physicochemical properties, including its band structure and nanoparticles size. [ABSTRACT FROM AUTHOR]

Purpose : This study is aimed to preliminary investigate whether transcranial alternating current stimulation (tACS) could affect explosive power considering genetic background in sport subjects. Methods : Seventeen healthy sports volunteers with at least 3 years of sports activities participated in the experiment. After 2 weeks of familiarization performed without any stimulation, each participant received either 50 Hz-tACS or sham-tACS. Before and after stimulation, subjects performed the following tests: (1) the squat jump with the hands on the hips (SJ); (2) countermovement jump with the hands on the hips (CMJ); (3) countermovement jump with arm swing (CMJ-AS); (4) 15-s Bosco's test; (5) seated backward overhead medicine ball throw (SBOMBT); (6) seated chest pass throw (SCPT) with a 3-kg rubber medicine ball; and (7) hand-grip test. Additionally, saliva samples were collected from each participant. Genotyping analysis was carried out by polymerase chain reaction (PCR). Results : No significant differences were found in sport performance of subjects after 50 Hz-tACS. Additionally, we did not find any influence of genetic background on tACS-related effect on physical performance. These results suggest that tACS at gamma frequency is not able to induce an after-effect modulating sport performance. Further investigations with larger sample size are needed in order to understand the potential role of non-invasive brain stimulation techniques (NIBS) in motor performances. Conclusions : Gamma-tACS applied before the physical performance fails to improve explosive power in sport subjects. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) represents one of the most fundamental techniques capable of satisfying the strict technological requirements imposed by the rapidly evolving electronic components industry. The actual scaling trend is rapidly leading to the fabrication of nanoscaled devices able to overcome limits of the present microelectronic technology, of which the memristor is one of the principal candidates. Since their development in 2008, TiO2 thin film memristors have been identified as the future technology for resistive random access memories because of their numerous advantages in producing dense, low power-consuming, three-dimensional memory stacks. The typical features of ALD, such as self-limiting and conformal deposition without lineof- sight requirements, are strong assets for fabricating these nanosized devices. This work focuses on the realization of memristors based on low-temperature ALD TiO2 thin films. In this process, the oxide layer was directly grown on a polymeric photoresist, thus simplifying the fabrication procedure with a direct liftoff patterning instead of a complex dry etching process. The TiO2 thin films deposited in a temperature range of 120-230°C were characterized via Raman spectroscopy and x-ray photoelectron spectroscopy, and electrical current-voltage measurements taken in voltage sweep mode were employed to confirm the existence of resistive switching behaviors typical of memristors. These measurements showed that these low-temperature devices exhibit an ON/OFF ratio comparable to that of a high-temperature memristor, thus exhibiting similar performances with respect to memory applications. [ABSTRACT FROM AUTHOR]

The objects of this research are commercially pure titanium surfaces, with multifunctional behavior, obtained through a chemical treatment and biological functionalization. The explored surfaces are of interest for dental implants, in contact with bone, where several simultaneous and synergistic actions are needed, in order to get a fast and effective osseointegration. The here described modified surfaces present a layer of titanium oxide, thicker than the native one, with a multi-scale surface topography (a surface roughness on the nano scale, which can be overlapped to a micro or macro roughness of the substrate) and a high density of OH groups, that increase surface wettability, induce a bioactive behavior (hydroxyapatite precipitation in simulated body fluid) and make possible the grafting of biomolecules (alkaline phosphatase, ALP, in the present research). The surface oxide is an efficient barrier against corrosion, with passive behavior both with and without application of an external voltage. [ABSTRACT FROM AUTHOR]

Introduction: Some evidence suggests an interference of obesity and alanine aminotransferase (ALT) levels on the diagnostic accuracy for advanced fibrosis of noninvasive tools such as liver stiffness measurement (LSM) by FibroScan, Fibrosis-4 (FIB-4), and nonalcoholic fatty liver disease fibrosis score (NFS). We assessed whether the diagnostic accuracy of LSM, Fibrosis-4 (FIB-4), and NFS and strategies based on the combination of these tools is affected by obesity and/or ALT levels., Methods: We analyzed data from 968 patients with a histological diagnosis of nonalcoholic fatty liver disease. FIB-4, NFS, and LSM by FibroScan were measured., Results: LSM was better than both FIB-4 and NFS for staging F3-F4 fibrosis area under the receiver operating characteristic curve test (AUC) 0.863, 0.777, and 0.765, respectively; P < 0.001 for both), showing higher accuracy and higher negative predictive value (NPV), but lower positive predictive value (PPV). LSM worked less well in high ALT (>100 IU) (AUC 0.811 vs 0.877, P = 0.04; PPV 57.5% vs 62.4%; NPV 90.7% vs 94%) or obese patients (AUC 0.786 vs 0.902, P < 0.001; PPV 58.7% vs 64.8%; NPV 88.3% vs 95.2%), the latter not being affected by the M or XL probe. Consistently, LSM worked better in terms of AUC and accuracy compared with both FIB-4 and NFS only in nonobese or high ALT patients, even with always keeping a slightly lower PPV. A serial combination of FIB-4 or NFS with LSM as the second test in patients in the gray area of the first test retained-in most scenarios-similar PPV and NPV compared with LSM alone. These strategies also increased the diagnostic accuracy of about 20% in all groups of patients, even if with a lower overall accuracy in obese patients (71.3% and 67.1% for FIB-4 and NFS as the first test, respectively) compared to nonobese patients (81.9% and 82.4% for FIB-4 and NFS as the first test, respectively)., Conclusions: All tested noninvasive tools have overall better NPV than PPV. LSM has a better diagnostic accuracy for advanced fibrosis than both FIB-4 and NFS only in nonobese and/or low ALT patients. Serial combination strategies are better than a single tool strategy, regardless of obesity and ALT levels, although the accuracy is lower in obese patients.

In this paper we report an innovative use of Poly(DiMethyl)Siloxane (PDMS) to design a microfluidic device that combines, for the first time, in one single reaction chamber, DNA purification from a complex biological sample (blood) without elution and PCR without surface passivation agents. This result is achieved by exploiting the spontaneous chemical structure and nanomorphology of the material after casting. The observed surface organization leads to spontaneous DNA adsorption. This property allows on-chip complete protocols of purification of complex biological samples to be performed directly, starting from cells lysis. Amplification by PCR is performed directly on the adsorbed DNA, avoiding the elution process that is normally required by DNA purification protocols. The use of one single microfluidic volume for both DNA purification and amplification dramatically simplifies the structure of microfluidic devices for DNA preparation. X-Ray Photoelectron Spectroscopy (XPS) was used to analyze the surface chemical composition. Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM) were employed to assess the morphological nanostructure of the PDMS-chips. A confocal fluorescence analysis was utilized to check DNA distribution inside the chip.