Microstructural and Mechanical Properties of Al2O3 and Al2O3/TiB2 Ceramics Consolidated by Plasma Pressure Compaction

Alumina oxide ceramics were produced by plasma pressure compaction (P2C) sintering process. Two types of pure α-alumina (Al2O3) and a mixture of alumina and titanium diboride (TiB2) powders were used as starting materials. Microstructure and mechanical properties, namely hardness, elastic modulus, and fracture toughness, were analyzed and correlated to the type of the sintered powders and the adopted manufacturing route. The microstructural development and the chemical composition variation induced by the sintering process were assessed by using scanning electron microscopy and x-ray diffraction. Nano-indentation and Chevron notch beam techniques were adopted to estimate the mechanical properties of the sintered ceramics. The conducted analyses show the capability of P2C technique to produce sound alumina ceramics. Pure alumina bulks exhibit a good level of compaction and mechanical properties close to those achievable with conventional sintering processes, such as hot isostatic pressing or spark plasma sintering. No significant alterations in the chemical composition of the ceramics were observed. The addition of the titanium diboride in the alumina powders caused a moderate increase in the grain size lowering the hardness and Young’s modulus of the sintered alumina and, at the same time, increased its fracture toughness to the occurrence of toughening mechanisms, like crack bridging and crack deflection

Isolation of intermediate compounds between hemoglobin and carbon monoxide.

A human hemoglobin solution partially saturated with carbon monoxide was rapidly quenched at -25 degrees C into a hydro-organic buffer containing ferricyanide. Under the experimental conditions of pH, ionic strength, and buffer composition used in this work, it was found that the deoxy hemes were rapidly transformed into their met form, whereas practically no carbon monoxide-bound hemes were oxidized before the separation of the mixture from the oxidizing agent. As a preliminary step to the analysis of the resulting solution, carbonylhemoglobin solutions partially oxidized with ferricyanide were studied by isoelectric focusing at -25 degrees C under identical conditions. The relative position in the gel of all nine possible valence hybrids was established as follows (going from the anodic to the cathodic side of the gel) alpha CO2 beta CO2, (alpha CO beta +)(alpha CO beta CO) (alpha CO beta CO), (alpha CO2 beta +2), (alpha + beta CO), (alpha + beta +)-(alpha CO beta CO), (alpha + beta +)(alpha CO beta +), (alpha +2 beta CO2), (alpha + beta +)(alpha + beta CO), alpha +2 beta +2. When carbonylhemoglobin and methemoglobin were mixed in equal proportion at -25 degrees C and then analyzed by isoelectric focusing at the same temperature, it was found that the contribution of valence hybrids other than alpha CO2 beta CO2 and alpha +2 beta +2 to the total amount of hemoglobin in the gel was no more than 6%. When carbonylhemoglobin and deoxyhemoglobin were mixed in the same proportion and incubated at 20 degrees C so to allow the redistribution of the carbon monoxide molecules between all possible binding sites to occur, a substantially higher amount of valence hybrids, derived from the oxidation of intermediate compounds of hemoglobin with carbon monoxide, was found. The isoelectric focusing separation indicated the presence in the original solution of intermediate species other than carbonylhemoglobin and deoxyhemoglobin at a concentration of about 10% of the total

Morphological, Gene, and Hormonal Changes in Gonads and In-Creased Micrococcal Nuclease Accessibility of Sperm Chromatin Induced by Mercury

Mercury is one of the most dangerous environmental pollutants. In this work, we analysed the effects of exposure of Mytilus galloprovincialis to 1, 10 and 100 pM HgCl2 for 24 h on the gonadal morphology and on the expression level of three stress genes: mt10, hsp70 and πgst. In this tissue we also evaluated the level of steroidogenic enzymes 3β-HSD and 17β-HSD and the expression of PL protein genes. Finally, we determined difference in sperm chromatin accessibility to micrococcal nuclease. We found alterations in gonadal morphology especially after exposure to 10 and 100 pM HgCl2 and hypo-expression of the three stress genes, particularly for hsp70. Furthermore, decreased labelling with both 3β-HSD and 17β-HSD antibodies was observed following exposure to 1 and 10 pM HgCl2 and complete absence at 100 pM HgCl2 exposure. Gonads of mussels exposed to all HgCl2 doses showed decreased expression of PL protein genes especially for PLIII. Finally, micrococcal nuclease digestions showed that all doses of HgCl2 exposure resulted in increased sperm chromatin accessibility to this enzyme, indicative of improper sperm chromatin structure. All of these changes provide preliminary data of the potential toxicity of mercury on the reproductive health of this mussel

High-efficiency cross-phase modulation in a gas-filled waveguide

Strong cross-Kerr nonlinearities have been long sought after for quantum information applications. Recent work has shown that they are intrinsically unreliable in traveling-wave configurations: cavity configurations avoid this, but require knowledge of both the nonlinearity and the loss. Here we present a detailed systematic study of cross-phase modulation and absorption in an Rb vapor confined within a hollow-core photonic crystal fiber. Using a two-photon transition, we observe phase modulations of up to pi rad with a signal power of 25 mu W, corresponding to a nonlinear Kerr coefficient, n(2), of 0.8 x 10(-6) cm(2)/W, or 1.3 x 10(-6) rad per photon

Human milk macronutrients and bioactive molecules and development of regional fat depots in Western Australian infants during the first 12 months of lactation

We investigated associations between intakes of human milk (HM) components (macronutrients and biologically active molecules) and regional fat depots development in healthy term infants (n = 20) across the first year of lactation. Infant limb (mid-arm and mid-thigh) lean and fat areas were assessed by ultrasound imaging at 2, 5, 9 and 12 months of age. Concentrations of HM total protein, whey protein, casein, adiponectin, leptin, lysozyme, lactoferrin, secretory IGA, total carbohydrates, lactose, HM oligosaccharides (total HMO, calculated) and infant 24-h milk intake were measured, and infant calculated daily intakes (CDI) of HM components were determined. This pilot study shows higher 24-h milk intake was associated with a larger mid-arm fat area (p = 0.024), higher breastfeeding frequency was associated with larger mid-arm (p = 0.008) and mid-thigh (p < 0.001) fat areas. Lysozyme (p = 0.001) and HMO CDI (p = 0.004) were time-dependently associated with the mid-arm fat area. Intakes of HM components and breastfeeding parameters may modulate infant limb fat depots development during the first year of age and potentially promote favorable developmental programming of infant body composition; however, further studies are needed to confirm these findings

Development and validation of a clinical risk score to predict the risk of SARS-CoV-2 infection from administrative data: A population-based cohort study from Italy

Background The novel coronavirus (SARS-CoV-2) pandemic spread rapidly worldwide increasing exponentially in Italy. To date, there is lack of studies describing clinical characteristics of the people at high risk of infection. Hence, we aimed (i) to identify clinical predictors of SARSCoV-2 infection risk, (ii) to develop and validate a score predicting SARS-CoV-2 infection risk, and (iii) to compare it with unspecific scores. Methods Retrospective case-control study using administrative health-related database was carried out in Southern Italy (Campania region) among beneficiaries of Regional Health Service aged over than 30 years. For each person with SARS-CoV-2 confirmed infection (case), up to five controls were randomly matched for gender, age and municipality of residence. Odds ratios and 90% confidence intervals for associations between candidate predictors and risk of infection were estimated by means of conditional logistic regression. SARS-CoV-2 Infection Score (SIS) was developed by generating a total aggregate score obtained from assignment of a weight at each selected covariate using coefficients estimated from the model. Finally, the score was categorized by assigning increasing values from 1 to 4. Discriminant power was used to compare SIS performance with that of other comorbidity scores. Results Subjects suffering from diabetes, anaemias, Parkinson’s disease, mental disorders, cardiovascular and inflammatory bowel and kidney diseases showed increased risk of SARSCoV-2 infection. Similar estimates were recorded for men and women and younger and older than 65 years. Fifteen conditions significantly contributed to the SIS. As SIS value increases, risk progressively increases, being odds of SARS-CoV-2 infection among people with the highest SIS value (SIS = 4) 1.74 times higher than those unaffected by any SIS contributing conditions (SIS = 1). Conclusion Conditions and diseases making people more vulnerable to SARS-CoV-2 infection were identified by the current study. Our results support decision-makers in identifying high-risk people and adopting of preventive measures to minimize the spread of further epidemic waves

The three years MOOC Experience of the University

Le numerose esperienze di alta formazione online, accanto allo sviluppo delle tecnologie e dei media digitali a supporto della didattica, hanno reso indispensabili una serie di azioni volte a sostenere le pratiche didattiche nelle università. A partire dalle raccomandazioni internazionali, dal 2016 l’Università di Foggia ha intrapreso una serie di azioni volte a promuovere un processo di rinnovamento delle pratiche e dei servizi, in risposta alle esigenze dei docenti universitari e degli studenti. All’interno del portale Eduopen, l’Ateneo foggiano ha erogato diversi corsi con l’obiettivo di innovare e riprogettare gli ambienti di apprendimento e sperimentare nuove tecnologie e metodologie, incoraggiando la partecipazione di tutti gli attori coinvolti. Tali aspetti sono strettamente collegati alla qualità della didattica, alla progettazione di percorsi di apprendimento in presenza e online, alla gestione di piattaforme e di risorse destinate non soltanto agli studenti iscritti ai singoli atenei, ma pensati per un pubblico globale. In questo primo triennio, l’Università di Foggia ha erogato circa 30 corsi MOOC rivolti ad una utenza piuttosto variegata e composta per lo più da studenti universitari, docenti, professionisti o semplici “curiosi”. Lo studio qui presentato, si configura come un primo tentativo di analisi descrittiva volta a fornire una accurata rappresentazione del fenomeno del dropout che si è verificato all’interno dei corsi MOOC offerti dall’ateneo foggiano. L’analisi parte da una lettura preliminare che aggrega i dati dell’offerta formativa MOOC considerando cinque variabili, limitatamente a 28 corsi dei 32 totali poiché sono stati esclusi i 4 Courseware. In questa fase, la lettura dei dati ha unicamente lo scopo di descrivere dropout al fine di prevedere la probabilità di abbandono e quindi attivare strategie di retention che saranno oggetto della fase successiva dello studio

Dati demografici degli studenti e selezione dei MOOC su Eduopen. Uno studio esplorativo sui MOOC erogati da UniFg

Today's generation of Massive Open Online Courses (MOOC) based on Open EducationalResources (OER) is able to offer high quality education to all those who decide touse this new type of online lifelong learning. Students who decide to enroll in thesecourses represent an increasingly diverse audience in terms of age and place of origin.The literature is being enriched with research studies that study the demographic dataof the students in relation to different variables, including the type of course MOOCchosen.17 universities join the Eduopen project, including the University of Foggia, which in thefirst three years has contributed to the growth and development of the platform by designingand delivering various MOOCs, involving numerous teachers and stimulatingan increasing number of students from non-geographical areas. necessarily surrounding.Specifically, in April 2019 Unifg counts:– 34 Mooc Courses;– 4 Pathway;– 45 Lecturers and Tutors.– more than 8000 students.This contribution presents an exploratory study carried out on the demographic data ofthe students enrolled in the courses offered by the University of Foggia. Specifically, thedemographic data of the students were analyzed based on age, educational qualificationsand city of origin and studied the correlations between these data and the choiceof available courses.La generazione odierna di Massive Open Online Courses (MOOC) basati su Open Educational Resources (OER) è in grado di offrire un’istruzione di qualità a tutti coloro che, per varie ragioni, utilizzano questa nuova metodologia di formazione online. Gli studenti che decidono di iscriversi a questi corsi costituiscono un pubblico sempre più diversificato per quanto riguarda età e luogo di provenienza.I ricercatori, educatori, e il pubblico in generale recentemente si è interessato molto su come differisce la provenienza dei corsisti e sulla relazione tra questa variabile e la scelta di un corso MOOC. Al progetto Eduopen aderiscono 17 Atenei, tra cui l’Università di Foggia, che nel primo triennio ha contribuito alla crescita e sviluppo della piattaforma progettando ed erogando diversi MOOC, coinvolgendo numerosi docenti e stimolando un numero sempre più crescente di studenti provenienti da zone geografiche non necessariamente circostanti. Nello specifico, ad aprile 2019 UniFg conta:– 34 Corsi MOOC;– 4 Pathway;– 45 Docenti e Tutor.– più di 8000 studenti.Questo contributo presenta uno studio esplorativo effettuato sui dati demografici degli studenti iscritti ai corsi offerti dall’ateneo foggiano. Nello specifico, sono stati analizzati i dati demografici degli studenti in base a età, titolo di studio e città di provenienza e studiate le correlazioni tra questi dati e la scelta dei corsi disponibili