1,140 research outputs found
The Sonophotocatalytic Degradation of Pharmaceuticals in Water by MnOx-TiO2 Systems with Tuned Band-Gaps
Advanced oxidation processes (AOPs) are technologies to degrade organic pollutants to carbon dioxide and water with an eco-friendly approach to form reactive hydroxyl radicals.Photocatalysis is an AOP whereby TiO2 is the most adopted photocatalyst. However, TiO2 features a wide (3.2 eV) and fast electron-hole recombination. When Mn is embedded in TiO2, it shifts the absorption wavelength towards the visible region of light, making it active for natural light applications. We present a systematic study of how the textural and optical properties of Mn-doped TiO2 vary with ultrasound applied during synthesis. We varied ultrasound power, pulse length, and power density (by changing the amount of solvent). Ultrasound produced mesoporous MnOx-TiO2 powders with a higher surface area (101\u2013158 m2 g 121), pore volume (0-13\u20130.29 cc g 121), and smaller particle size (4\u201310 \ub5m) than those obtained with a conventional sol-gel method (48\u2013129 m2 g 121, 0.14\u20130.21 cc g 121 , 181 \ub5m, respectively). Surprisingly, the catalysts obtained with ultrasound had a content of brookite that was at least 28%, while the traditional sol-gel samples only had 7%. The samples synthesized with ultrasound had a wider distribution of the band-gaps, in the 1.6\u20131.91 eV range, while traditional ones ranged from 1.72 eV to 1.8 eV. We tested activity in the sonophotocatalytic degradation of two model pollutants (amoxicillin and acetaminophen). The catalysts synthesized with ultrasound were up to 50% more active than the traditional samples
Art as human reflective practice
L'arte è una pratica umana di riflessività che si può trovare in diversi contesti e gli studi presentati lo dimostrano. Il primo capitolo presenta una panoramica dell'arte visiva nelle religioni monoteiste e indaga i legami tra arte religiosa e psicologia. Nel secondo capitolo, la ricerca indaga i giudizi estetici e di vitalità di volti che rappresentano morti, Santi e non Santi. I risultati mostrano che i Santi sono stati giudicati più belli, mentre i non Santi sono stati giudicati più vitali. Questo suggerisce una relazione tra etica ed estetica anche nella percezione dell'arte. Il terzo capitolo esamina il rapporto tra arte, robot ed esseri umani. Credere che l'opera d'arte sia stata creata da un robot, piuttosto che da un essere umano, influisce sulla valutazione estetica? La ricerca ha dimostrato che i dipinti che le persone credono siano stati realizzati da esseri umani ricevono un alto apprezzamento estetico, mentre i dipinti che le persone credono siano stati realizzati da robot ricevono un basso punteggio di competenza artistica. Da questi risultati, l'arte viene vista come un'abilità puramente umana.Art is a human practice of reflexivity that can be found in different contexts, and the studies presented demonstrate this. The first chapter presents an overview of visual art in monotheistic religions and investigates the links between religious art and psychology. In the second chapter, the research investigates the aesthetic and vitality judgments of faces representing dead, Saints and non-Saints. In the results, Saints were judged more beautiful while non-Saints were judged more vital. This suggests a relationship between ethics and aesthetics in the perception of art. The third chapter examines the relationship between art, robots, and humans. Does believing that artwork was created by a robot, rather than a human, affect aesthetic evaluation? The research showed that paintings that people believe were made by humans receive high aesthetic appreciation, while paintings that people believed were made by robots receive low artistic competence scores. From these results, art is seen as a purely human skill
Determinismo, indeterminismo e il problema del futuro vero
All’interno del dibattito che anima la filosofia temporale esistono numerose correnti di pensiero su quale posizione si debba adottare riguardo al problema del valore di verità delle proposizioni sul futuro. Nella prima parte dell’articolo verrà tracciato il quadro generale della discussione mediante una ricostruzione storica delle varie argomentazioni – da Aristotele e Diodoro Crono a Prior – e verranno analizzate le posizioni che si sono sviluppate, a partire da queste, nell’età contemporanea. Nella seconda parte invece tenterò di mostrare come la competizione fra la teoria del futuro vero e il sistema ockhamista di Prior non si basi su due differenti concetti di contingenza, ma sulla mancata distinzione, all’interno del sistema ockhamista, di due significati di ‘determinato’ e sulla conseguente confusione che investe il concetto di necessità . Una volta recuperata tale distinzione la teoria ockhamista può essere riformulata e le due diverse posizioni si rivelano essere, semplicemente, teorie sulla determinatezza degli stati futuri.
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A large number of schools of thought enliven the philosophical debate on how we can manage the truth-values of propositions about the future. In the first part of this paper I’ll draw an overall view of the discussion, proposing an historical reconstruction of the arguments – from Aristotle and Diodoro Crono to Prior – that will give us the instruments to understand the current state of the debate. After that, in the second part, I’ll argue that the discussion between theory of the true future and Prior’s ockhamist theory is not based on two different concepts of contingency, but instead on the lack of distinction between two different meanings of ‘determined’ inside the ockhamist system. Recovering this distinction is the first step to understand that the real competition between the two systems is not about contingency, but only about the determination of the future
Low Mortality and Key Aspects of Delivery of Care for End-Stage Renal Disease in Italy
End-stage renal disease (ESRD) is a global health problem. There are differences in mortality among patients with ESRD amid industrialized countries that may be related to their respective systems of delivery of care. A nationwide survey was completed in Italy, a country with low mortality rate for ESRD patients, in order to help understand key aspects of ESRD delivery of care that contribute to mortality. Survey responses were obtained and analyzed from 131 of 575 dialysis centers (23%), covering data from 13,170 dialysis patients in 2006. The mortality rate was 11.2% and the prevalence of diabetes-associated kidney disease was 21%. Of the patients, 88% were on hemodialysis and 12% were on peritoneal dialysis. Most patients were in the age range of 65–75 years (66.7%), were seen by a nephrologist at CKD stage 3, and began dialysis at mean estimated GFR of 9.6 ml/min/1.73 m2. AV fistulae were the prevailing form of vascular access (83%) and were most frequently placed by a nephrologist (61.2%). In 98% of the dialysis centers, a nephrologist was present during dialysis sessions. The following may explain the low mortality for ESRD patients in Italy: low prevalence of diabetes, high use of AV fistulae, delivery of care by nephrologists beginning in pre-ESRD stages, their involvement in placement of dialysis vascular access, and their physical presence requirement during dialysis sessions. These findings portray key aspects of the contemporary delivery of care for Italian dialysis patients and provide a platform for international comparison of healthcare systems for ESRD
An ultrasound-assisted photocatalytic treatment to remove an herbicidal pollutant from wastewaters
Pollutants of emerging concern contaminate surface and ground water. Advanced oxidation processes treat these molecules and degrade them into smaller compounds or mineralization products. However, little information on coupled advanced oxidation techniques and on the degradation pathways of these pollutants is available to identify possible ecotoxic subproducts. In the present work, we investigate the ultrasound assisted photocatalytic degradation pathway of the herbicide Isoproturon. We worked in batch mode in a thermostatic glass reactor. We compared the activity of nanometric TiO2 P25 with that of Kronos 1077, a micrometric TiO2. We discuss the individual, additive and synergistic degradation action of photolysis, sonolysis, sonophotolysis, and sonophotocatalysis by varying catalyst loading and/or ultrasound power for the last three techniques. With 0.1 g L 121 catalyst, photocatalysis and sonophotopcatalysis completely degrade Isoproturon within 240 min and 60 min, respectively (>99% conversion). Sonophotocatalysis breaks Isoproturon down into smaller molecules than photocatalysis alone
Curved Walking Rehabilitation with a Rotating Treadmill in Patients with Parkinson’s Disease: A Proof of Concept
Training subjects to step-in-place eyes open on a rotating platform while maintaining a fixed body orientation in space [podokinetic stimulation (PKS)]
produces a posteffect consisting in inadvertent turning around while stepping-in-place eyes closed [podokinetic after-rotation (PKAR)]. Since the
rationale for rehabilitation of curved walking in Parkinson's disease is not fully known, we tested the hypothesis that repeated PKS favors the production of curved walking in these patients, who are uneasy with turning, even when straight walking is little affected. Fifteen patients participated in 10 training sessions distributed in 3 weeks. Both counterclockwise and clockwise PKS were randomly administered in each session. PKS velocity and duration were gradually increased over sessions. The velocity and duration of the following PKAR were assessed. All patients showed PKAR, which increased progressively in peak velocity and duration. In addition, before and at the end of the treatment, all patients walked overground along linear and circular trajectories. Post-training, the velocity of walking bouts increased, more so for the circular than the linear trajectory. Cadence was not affected. This study has shown that parkinsonian patients learn to produce turning while stepping when faced with appropriate training and that this capacity translates into improved overground curved walking
Walking Along Curved Trajectories. Changes With Age and Parkinson's Disease. Hints to Rehabilitation
In this review, we briefly recall the fundamental processes allowing us to change locomotion trajectory and keep walking along a curved path and provide a review of contemporary literature on turning in older adults and people with Parkinson's Disease (PD). The first part briefly summarizes the way the body exploits the physical laws to produce a curved walking trajectory. Then, the changes in muscle and brain activation underpinning this task, and the promoting role of proprioception, are briefly considered. Another section is devoted to the gait changes occurring in curved walking and steering with aging. Further, freezing during turning and rehabilitation of curved walking in patients with PD is mentioned in the last part. Obviously, as the research on body steering while walking or turning has boomed in the last 10 years, the relevant critical issues have been tackled and ways to improve this locomotor task proposed. Rationale and evidences for successful training procedures are available, to potentially reduce the risk of falling in both older adults and patients with PD. A better understanding of the pathophysiology of steering, of the subtle but vital interaction between posture, balance, and progression along non-linear trajectories, and of the residual motor learning capacities in these cohorts may provide solid bases for new rehabilitative approaches
Incongruity of Geometric and Spectral Markers in the Assessment of Body Sway
Different measurements of body oscillations in the time or frequency domain are being employed as markers of gait and balance abnormalities. This study investigates basic relationships within and between geometric and spectral measures in a population of young adult subjects. Twenty healthy subjects stood with parallel feet on a force platform with and without a foam pad. Adaptation effects to prolonged stance were assessed by comparing the first and last of a series of eight successive trials. Centre of Foot Pressure (CoP) excursions were recorded with Eyes Closed (EC) and Open (EO) for 90s. Geometric measures (Sway Area, Path Length), standard deviation (SD) of the excursions, and spectral measure (mean power Spectrum Level and Median Frequency), along the medio-lateral (ML) and antero-posterior (AP) direction were computed. Sway Area was more strongly associated than Path Length with CoP SD and, consequently, with mean Spectrum Level for both ML and AP, and both visual and surface conditions. The squared-SD directly specified the mean power Spectrum Level of CoP excursions (ML and AP) in all conditions. Median Frequency was hardly related to Spectrum Level. Adaptation had a confounding effect, whereby equal values of Sway Area, Path Length, and Spectrum Level corresponded to different Median Frequency values. Mean Spectrum Level and SDs of the time series of CoP ML and AP excursions convey the same meaning and bear an acceptable correspondence with Sway Area values. Shifts in Median Frequency values represent important indications of neuromuscular control of stance and of the effects of vision, support conditions, and adaptation. The Romberg Quotient EC/EO for a given variable is contingent on the compliance of the base of support and adaptation, and different between Sway Area and Path Length, but similar between Sway Area and Spectrum Level (AP and ML). These measures must be taken with caution in clinical studies, and considered together in order to get a reliable indication of overall body sway, of modifications by sensory and standing condition, and of changes with ageing, medical conditions and rehabilitation treatment. However, distinct measures shed light on the discrete mechanisms and complex processes underpinning the maintenance of stance
Athrombocytopenic thrombotic microangiopathy, a condition that could be overlooked based on current diagnostic criteria
Background. Thrombotic thrombocytopenic purpura (TTP) and haemolytic uraemic syndrome (HUS) are thrombotic microangiopathies (TMAs). They are generally diagnosed and treated by plasmapheresis in the presence of non-immune haemolytic anaemia and thrombocytopenia. Yet, many individuals admitted in our hospital for athrombocytopenic renal failure of unknown cause were reported to have TMA as main lesion on kidney biopsies
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