729 research outputs found
Photoelectrocatalytic performances of nanostructured/decorated TiO 2 electrodes: Effect of wavelength and cell configuration
The behaviour of TiO2 based electrodes was investigated during the photoelectrocatalytic water splitting process. TiO2 nanotubes and compact oxide structures were obtained by electrochemical oxidation of Ti foils. A subsequent hydrothermal process carried out at both the nanotubular and compact oxide structures allowed decorating the structure by TiO2 nanoparticles. The synthesized TiO2 samples worked as photoanodes both in a bulk three electrode cell and in a thin gap cell. The results from measurements of the photocurrent and from electrochemical impedance spectroscopy were used to highlight a combined effect of the wavelength of the incident light and the kind of cell configuration, on the global performance of the systems. The results indicate that the decoration process does not result only in a simple increase of the specific surface, but it also determines a different concentration of the bulk and superficial sites in the electrode. The different response of the sites at different wavelengths, along with the accessibility of the electrolyte to the porous structure are evocated to justify the experimental behaviour observed
Bibliometric analysis on the papers dedicated to microplastics in wastewater treatments
The presence of microplastics (MPs) in the environment is becoming a problem for soils and seas, as well as for the food chain of animals and humans. The scientific community has been called upon to contribute to solving the problem and several papers have been published, especially in the last decade. The aim of this work is to carry out a bibliometric analysis of the scientific literature dedicated to the problem of MPs, highlighting its course over the years, and to identify the sectors to which the research could be profitably addressed. The VOSviewer software has been used to perform the analysis of the data in which specific maps were used to represent the network of the relationships among countries, journals, organizations, authors, and keywords related to the investigated topic and subtopics. The results of the survey demonstrated that during the investigated range of time, most attention has been paid to the individuation of the MPs, and to marine pollution, while a gap seems to exist in the possible advanced oxidation processes specifically addressing the degradation of MPs and their derivates
Effect of potential and chlorides on photoelectrochemical removal of diethyl phthalate from water
Removal of persistent pollutants from water by photoelectrocatalysis has emerged as a promising powerful process. Applied potential plays a key role in the photocatalytic activity of the semi-conductor as well as the possible presence of chloride ions in the solution. This work aims to investigate these effects on the photoelectrocatalytic oxidation of diethyl phthalate (DEP) by using TiO2 nanotubular anodes under solar light irradiation. PEC tests were performed at constant potentials under different concentration of NaCl. The process is able to remove DEP following a pseudo-first order kinetics: values of kapp of 1.25 × 10−3 min−1 and 1.56 × 10−4 min−1 have been obtained at applied potentials of 1.8 and 0.2 V, respectively. Results showed that, depending on the applied potential, the presence of chloride ions in the solution affects the degradation rate resulting in a negative effect: the presence of 500 mM of Cl− reduces the value of kapp by 50 and 80% at 0.2 and 1.8 V respectively
Exploring relationships between the distribution of giant red shrimp Aristaeomorpha foliacea (Risso, 1827) and environmental factors in the Central-Western Mediterranean Sea
Mediterranean giant red shrimp Aristaeomorpha foliacea (Risso, 1827) is one of the dominant species in deep-sea megafaunal assemblages, plays a key role in deep-sea communities and it is considered one of the most important targets of deep-water trawl fishing. Although a large number of studies have analysed the spatial distribution of epibenthic crustaceans in bathyal habitats with respect to environmental, geomorphological and hydrological factors, as well as fishing pressure, the manner in which these variables synergistically affect the spatio-temporal changes of giant red shrimp is unclear. To analyse the possible effects of abiotic predictors on the spatio-temporal distribution of giant red shrimp, Generalized Additived Models (GAMs) and Regression Trees were produced. Biological data were collected during the MEDITS trawl surveys carried out in the Sea of Sardinia (2009-2014), during which environmental data were obtained with a multiparametric probe. A longitudinal (west-east) trend was found, with higher abundances at depths of 400-600 m, corresponding to salinity values of 38.1-38.5 psu and temperatures of 13.6-13.8°C. Our results confirm the existence of a tight linkage between the distribution of the Levantine Intermediate Water (LIW) from the eastern Mediterranean Sea and the preferential habitat characteristics of the giant red shrimp. We suggest that a deeper knowledge of the relationships between abiotic (hydrological) factors in the water column and the distribution of Mediterranean resources, such as the giant red shrimp, can provide valuable support for their better management, at the local scale (Sardinia) and across the whole Mediterranean Sea. al use only
Functional outcomes and clinical strength assessment after infraspinatus-sparing surgical approach to scapular fracture: Does it really make a difference?
Background: Surgical treatment of scapular fractures with posterior approach is frequently associated with postoperative infraspinatus hypotrophy and weakness. The aim of this retrospective study is to compare infraspinatus strength and functional outcomes in patients treated with the classic Judet versus modified Judet approach for scapular fracture. Patients and methods: 20 cases with scapular neck and body fracture treated with posterior approach for lateral border plate fixation were reviewed. In 11 of 20 cases, we used the modified Judet approach (MJ group), and in 9 cases we used the classic Judet approach (CJ group). All fractures were classified according to the AO classification system. At follow-up examinations, patients had X-ray assessment with acromiohumeral distance (AHD) measurement, clinical evaluation, active range of motion (ROM) examination, Constant Shoulder Score, and Disability of the Arm, Shoulder and Hand (DASH) Score. Infraspinatus strength assessment was measured using a dynamometer during infraspinatus strength test (IST) and infraspinatus scapular retraction test (ISRT). Results: Demographic data did not significantly differ between the CJ group and MJ group, except for mean follow-up, which was 4.15\ua0years in the CJ group and 2.33 in the MJ group (p\ua0<\ua00.001). All X-ray examinations showed fracture healing. AHD was significantly decreased in the CJ group (p\ua0=\ua00.006). We did not find significant differences in active ROM between the MJ and CJ groups in the injured arm (p\ua0<\ua00.05). The Constant Score was 75.83 (\ub114.03) in the CJ group and 82.75 (\ub110.72) in the MJ group (p\ua0=\ua00.31); DASH Score was 10.16 in the CJ group and 6.25 in the MJ group (p\ua0=\ua00.49). IST showed mean strength of 8.38\ua0kg (\ub11.75) in the MJ group and 4.61\ua0kg (\ub11.98) in the CJ group (p\ua0=\ua00.002), ISRT test was 8.7 (\ub11.64) in the MJ group and 4.95 (\ub12.1) in the CJ group (p\ua0=\ua00.002). Infraspinatus hypotrophy was detected during inspection in six patients (five in the CJ group and one in the MJ group); it was related to infraspinatus strength weakness in IST and ISRT (p\ua0<\ua00.001). Conclusions: Infraspinatus-sparing surgical approach for scapular fracture avoids infraspinatus hypotrophy and external-rotation strength weakness. We suggest use of the modified Judet approach for scapular fracture and to restrict the classic Judet approach to only when the surgeon believes that the fracture is not easily reducible with a narrower exposure. Level of evidence: Level\ua0IV
Electrochemical synthesis of polyaniline/metal-based anodes and their use in microbial fuel cell
A limited number of metals may be suitable as bioanode material: noble metals, such as gold and platinum, could be the optimum choice being electrochemically inert in the operational potential window of the bioelectrochemical system. However, high costs limit their wide scale application. Even though its antimicrobial nature, copper is being considered as a promising alternative anode material, due to its high conductivity, that allows minimising the electrode material costs. Literature research indicated that high-performing electrochemically active biofilms may be grown on this metal. In the present work, gold and copper substrates have been coated by a conductive polymer (PANI), using a layer – by – layer procedure: surface grafting by reduction of 4-nitrobenzendiazonium salt was followed by reduction of nitro- to amino-groups; PANI was electrodeposited on this under-layer. The synthesized anodes were tested as working electrodes (WE) in a microbial fuel cell fed with anaerobic sludge and acetate; to assess the growth of the biofilm on the WE surface, the trend of the bioelectrocatalytic current of acetate oxidation was monitored over time. Cyclic voltammetries reveal the presence of typical redox couples related to the presence of electroactive microorganisms on the electrode surface. Preliminary data show bioelectrochemical activity on polyaniline-coated metal surfaces
DISTRIBUTION OF SPAWNING AND NURSERY GROUNDS FOR DEEP–WATER RED SHRIMPS IN THE CENTRAL WESTERN MEDITERRANEAN SEA
The presence of spawning and nursery grounds of Aristeids in the central western Mediterranean Sea were investigated using fishery-independent data (trawl surveys, 1994–2012). Spatial distributions were generated for mature animals and recruits, for both spring/summer and autumn data, using an inverse distance weighted deterministic interpolation. The persistence index was used to identify stable spawning and nursery grounds in the Sardinian slope region for Aristaeomorpha foliacea and Aristeus antennatus. Areas of aggregation for recruits and mature females appear connected with important physical habitat features. The analysis also suggests a seasonal bathymetric distribution for nursery areas. The recruits of A. foliacea are located in the upper part of the continental slope (377-450 m) in spring-summer and reach greater depths (468-628 m) in autumn. For A. antennatus, for which nursery areas only emerge in autumn, there is presumably an opposite ontogenic migration, from deep sea to upper slope, during the summer (575-681 m). Results indicate also a partial overlap between the nursery and spawning grounds of both species. In this particular areas, local environmental conditions such as upwelling events or the presence of canyons and seamounts seem to play an important role in their distribution. This study generated also relevant information on the spatial and temporal distribution of seasonal or persistent aggregations of spawners and recruits, providing scientific elements to suggest the feasibility of protecting these important resources
Gut microbiota markers associated with obesity and overweight in Italian adults
In the present study, we characterized the distinctive signatures of the gut microbiota (GM) from overweight/obese patients (OB), and normal-weight controls (NW), both of Sardinian origin. Fecal bacterial composition of 46 OB patients (BMI = 36.6 ± 6.0; F/M = 40/6) was analyzed and compared to that of 46 NW subjects (BMI = 21.6 ± 2.1; F/M = 41/5), matched for sex, age and smoking status, by using 16S rRNA gene sequencing on MiSeq Illumina platform. The gut microbial community of OB patients exhibited a significant decrease in the relative abundance of several Bacteroidetes taxa (i.e. Flavobacteriaceae, Porphyromonadaceae, Sphingobacteriaceae, Flavobacterium, Rikenella spp., Pedobacter spp., Parabacteroides spp., Bacteroides spp.) when compared to NW; instead, several Firmicutes taxa were significantly increased in the same subjects (Lachnospiraceae, Gemellaceae, Paenibacillaceae, Streptococcaceae, Thermicanaceae, Gemella, Mitsuokella, Streptococcus, Acidaminococcus spp., Eubacterium spp., Ruminococcus spp., Megamonas spp., Streptococcus, Thermicanus, Megasphaera spp. and Veillonella spp.). Correlation analysis indicated that body fatness and waist circumference negatively correlated with Bacteroidetes taxa, while Firmicutes taxa positively correlated with body fat and negatively with muscle mass and/or physical activity level. Furthermore, the relative abundance of several bacterial taxa belonging to Enterobacteriaceae family, known to exhibit endotoxic activity, was increased in the OB group compared to NW. The results extend our knowledge on the GM profiles in Italian OB, identifying novel taxa linking obesity and intestine
Determination of salivary cortisol to assess time related changes of the adrenal response to stress in critically ill patients
- …