1,052 research outputs found
Hug-like island growth of Ge on strained vicinal Si(111) surfaces
We examine the structure and the evolution of Ge islands epitaxially grown on
vicinal Si(111) surfaces by scanning tunneling microscopy. Contrary to what is
observed on the singular surface, three-dimensional Ge nanoislands form
directly through the elastic relaxation of step-edge protrusions during the
unstable step-flow growth. As the substrate misorientation is increased, the
islands undergo a shape transformation which is driven by surface energy
minimization and controlled by the miscut angle. Using finite element
simulations, we show that the dynamics of islanding observed in the experiment
results from the anisotropy of the strain relaxation.Comment: 4 figure
Model -- curves and figures of merit of underdamped deterministic Josephson ratchets
We propose simple models for the current-voltage characteristics of typical
Josephson ratchets. We consider the case of a ratchet working against a
constant applied counter force and derive analytical expressions for the key
characteristics of such a ratchet: rectification curve, stopping force, input
and output powers and rectification efficiency. Optimization of the ratchet
performance is discussed
Phase retrapping in aφJosephson junction: onset of the butterfly effect
We investigate experimentally the retrapping of the phase in a
φ
Josephson junction upon return of the junction to the zero-voltage state. Since the Josephson energy profile
U
0
(
ψ
)
in
φ
JJ is a
2
π
periodic double-well potential with minima at
ψ
=
±
φ
mod
2
π
, the question is at which of the two minima
−
φ
or
+
φ
the phase will be trapped upon return from a finite voltage state during quasistatic decrease of the bias current (tilt of the potential). By measuring the relative population of two peaks in escape histograms, we determine the probability of phase trapping in the
±
φ
wells for different temperatures. Our experimental results agree qualitatively with theoretical predictions. In particular, we observe an onset of the butterfly effect with an oscillating probability of trapping. Unexpectedly, this probability saturates at a value different from 50% at low temperatures
Self-Assessment of Adherence to Medication: A Case Study in Campania Region Community-Dwelling Population.
Objectives. The aim of the study was to assess self-reported medication adherence measure in patients selected during a health education and health promotion focused event held in the Campania region. The study also assessed sociodemographic determinants of adherence. Methods. An interviewer assisted survey was conducted to assess adherence using the Italian version of the 8-item Morisky Medication Adherence Scale (MMAS-8). Participants older than 18 years were interviewed by pharmacists while waiting for free-medical checkup. Results. A total of 312 participants were interviewed during the Health Campus event. A total of 187 (59.9%) had low adherence to medications. Pearson's bivariate correlation showed positive association between the MMAS-8 score and gender, educational level and smoking (P < 0.05). A multivariable analysis showed that the level of education and smoking were independent predictors of adherence. Individuals with an average level of education (odds ratio (OR), 2.21, 95% confidence interval (CI), 1.08-4.52) and nonsmoker (odds ratio (OR) 1.87, 95% confidence interval (CI), 1.04-3.35) were found to be more adherent to medication than those with a lower level of education and smoking. Conclusion. The analysis showed very low prescription adherence levels in the interviewed population. The level of education was a relevant predictor associated with that result
Farmaci oppioidi e Cannabis nella terapia del dolore
[English]:“Opioid and Cannabis in Pain Control” is the result of studies performed by the Pharmacy Department and the “Centro Interdipartimentale di Ricerca in Farmacoeconomia e Farmacoutilizzazione” (CIRFF) of the University of Naples, “Federico II”. This book is aimed to those who work in a pharmacy and who, scholars, teachers or students, are interested in delve into the issue. The text analyzes different topics with an interdisciplinary approach. A large part is devoted to the chemical and pharmacological aspects related to this topic. Subsequently, the text focuses the theme, still very debated, of using opioids and Cannabis in therapy through an exhaustive analysis of the entire existing legislation: from the first laws promulgated by the Kingdom of Italy until the last ministerial circulars by Italian republic. Finally yet importantly, an important part of the book focuses on medical and therapeutic interpretation with regard to the effects on pain control, where opioids and Cannabis are not only a fruitful frontier of research, but also a consolidated and effective tool to counteract some types of pain / [Italiano]: “Farmaci oppioidi e Cannabis nella terapia del dolore” rappresenta il frutto di alcuni studi, condotti per almeno tre lustri nel Dipartimento di Farmacia e nel Centro Interdipartimentale di Ricerca in Farmacoeconomia e Farmacoutilizzazione (CIRFF) della Federico II, e si rivolge sia a chi presta servizio ogni giorno in una farmacia, sia a chi, studioso, docente o studente, è interessato ad approfondire l’argomento. Il testo, utilizzando un approccio interdisciplinare, si muove su piani euristici differenti. Naturalmente, ampio spazio è stato dedicato alla parte farmaceutica, analizzando tutti gli aspetti chimici e farmacologici connessi a questo tema. Un secondo punto di rilievo riguarda la problematica normativa legata alla dibattuta questione dell’utilizzo in terapia degli oppioidi e della Cannabis. In tal senso, si è cercato di offrire una prospettiva chiara ed esauriente del complesso quadro legislativo vigente: a partire dalle prime leggi promulgate dal Regno d’Italia, fino ad arrivare alle ultime circolari ministeriali in materia, è stata rivista ed esaminata l’intera normativa sulle sostanze stupefacenti, spiegandone anche i passaggi più delicati e controversi. Infine, soprattutto per ciò che concerne le ricadute sulla terapia del dolore, una parte significativa del libro si è concentrata sull’interpretazione medica e terapeutica, dove i farmaci oppioidi e la Cannabis costituiscono non solo una feconda frontiera di ricerca, ma anche un consolidato ed efficace strumento per contrastare alcune tipologie di dolore
Italian translation and cultural adaptation of the communication assessment tool in an outpatient surgical clinic
The aim of the study is to translate and cross-culturally adapt, for use in the Italian context, the Communication Assessment Tool (CAT) developed by Makoul and colleagues
Innovative olive tree leaves shredder prototype for the valorization of wasted leaves: An application to high-quality compost production
Extra virgin olive oil is considered worldwide as one of the most important products, a standard bearer of the Mediterranean diet. Despite this, the production chain of extra virgin olive oil generates four times more waste than quantity of oil. For this reason, the disposal of olive mill wastes represents a significant environmental problem in all the Mediterranean countries. In this direction, several innovations and improvement strategies were proposed in the literature to correctly manage these by-products and, in some cases, to valorize them by the recovery of polyphenols and other interesting substances. However, innovations and improvement strategies for the valorization of olive tree leaves are definitely neglected in the literature, thus motivating this work. The aims of this work are as follow: firstly, to develop and test an innovative olive tree leaves shredder prototype to help olive oil millers in the management of waste leaves deriving from pruning and olive oil production; secondly, to test the combination of the minced olive tree leaves with other by-products in the production of high-quality compost. The results showed the effectiveness of the tested olive tree leaves shredder in significantly reducing the volume occupied by the leaves by 40%. Moreover, the mixing of the minced olive tree leaves with other by-products lead to a high-quality compost which, in accordance with Italian legislation, could even be certified and labeled with this denomination. Future research will investigate the quantification of the benefits in terms of environmental impacts using life cycle assessment
Classical and quantum properties of phi Josephson junctions
Josephson junctions (JJs) with nontrivial current phase relation (CPR) have attracted a large interest over the last 20 years, due to the new fundamental physics and their potential for many applications in both classical and quantum circuits, e.g., as phase batteries or memory elements.
In this thesis, the properties of varphi Josephson junctions in the classical and in the quantum domain are studied. A varphi JJ is a junction with a doubly degenerate ground state phase phi=varphi, where 0<varphi<pi. Such a system can be obtained combining a 0 and a pi JJ, with phases phi=0 and phi=pi in the ground state, respectively. The two segments should not be very different, with a small asymmetry either in the geometrical lengths or in the different critical currents densities.
The experiments presented here have been performed on varphi junctions fabricated with two different technologies. The first one is based on superconductor-insulator-ferromagnet-superconductor (SIFS) JJs with a tailored ferromagnetic barrier. Realization of the varphi state with such a technology was already proven in the past. In the thesis, SIFS varphi junctions were used for two main experiments in the classical limit. First, we studied the retrapping dynamics of the Josephson phase upon returning from the resistive to the zero-voltage state. Since a varphi JJ has two possible ground state phases, it is not obvious where the phase ends when the junction jumps back to the zero-voltage state. Second, we demonstrated the operation of the varphi JJ as a deterministic ratchet. The energy U(phi) of a varphi JJ is tunable by an external magnetic field, and a ratchet potential with no reflection symmetry can be easily obtained.
In the quantum regime a varphi JJ can be regarded as macroscopic two-level system. Hence, it would also be interesting to investigate its quantum properties. However, several technological drawbacks affecting the SIFS varphi JJs (e.g., low j_c and high damping) prevented experiments in this domain. As a first attempt to improve our technology, we fabricated SIFS JJs with an additional thin superconducting interlayer s, obtaining SIsFS structures. It was proposed that such junctions can have parameters (e.g., j_c, characteristic voltage V_c) comparable to conventional superconductor-insulator-superconductor (SIS) junctions. Although we actually detected an improvement with respect to the SIFS JJs, the typical parameters obtained did not fulfill our purposes.
A more successful technology was attained with SIS JJs, where the phase discontinuity is artificially created by means of the current I_inj circulating through two microinjectors attached to the junction. In this thesis, I present the experiments carried out on such JJs in the quantum regime, where we investigated the escape mechanism of the Josephson phase from both ground states.
Finally, I give an outlook on measurements to be performed in the near future, where we want to create a varphi JJ with an energy profile which is fully tunable electronically. Simulations predict that such a junction can be realized out of a SIS JJ with three pairs of injectors. The Josephson potential can be then controlled by adjusting the current through the two additional injector pairs, I_inj2 and I_inj3, and the external magnetic flux. Preliminary experimental characterization of such multiple injector junctions in the classical limit, together with numerical fits, are shown
Fixed Versus Free Combinations of Antihypertensive Drugs: Analyses Of Real-World Data Of Persistence With Therapy In Italy
Purpose: To analyse the pattern of use and cost of antihypertensive drugs in new users in an Italian population, and explore the patient/treatment factors associated with the risk of therapy discontinuation. Patients and methods: In this retrospective study, information was collected from a population-based electronic primary-care database. Persistence with medication use 1 year from therapy initiation was evaluated for each user using the gap method. Each new user was classified according to his/her pattern of use as: \u201ccontinuer\u201d, \u201cdiscontinuer\u201d \u201cswitching\u201d or \u201cadd-on\u201d. A Cox regression model was used to analyse the factors influencing therapy discontinuation. Primary-care costs comprised specialists\u2019 visits, diagnostic procedures and pharmacologic therapies. Results: Among 14,999 subjects included in persistence analyses, 55.1% of cases initially started on monotherapy were classified as discontinuers vs 36.5% of cases taking combination therapy (42.3% vs 32.7%, respectively, for free and fixed combinations, P < 0.01). Old age, high cardiovascular risk and being in receipt of fixed-combination therapy were associated with greater persistence. Overall, the primary-care cost/person/year of hypertension management was 3c\u20ac95.3 (IQR, 144.9). The monotherapy cost was \u20ac88 per patient (IQR, 132.9), and that for combination therapy was \u20ac151\ub1148.3. The median cost/patient with a fixed combination was lower than that for a free combination (\u20ac98.4 (IQR, 155.3) and \u20ac154.9 (IQR, 182.6), respectively). Conclusion: The initial type of therapy prescribed influences persistence. Prescribing fixed combinations might be a good choice as initial therapy
- …
