78 research outputs found
Effective Dynamics of Extended Fermi Gases in the High-Density Regime
We study the quantum evolution of many-body Fermi gases in three dimensions, in arbitrarily large domains. We consider both particles with non-relativistic and with relativistic dispersion. We focus on the high-density regime, in the semiclassical scaling, and we consider a class of initial data describing zero-temperature states. In the non-relativistic case we prove that, as the density goes to infinity, the many-body evolution of the reduced one-particle density matrix converges to the solution of the time-dependent Hartree equation, for short macroscopic times. In the case of relativistic dispersion, we show convergence of the many-body evolution to the relativistic Hartree equation for all macroscopic times. With respect to previous work, the rate of convergence does not depend on the total number of particles, but only on the density: in particular, our result allows us to study the quantum dynamics of extensive many-body Fermi gases
Cross-cultural adaptation and validation of the Italian version of the Western Ontario Rotator Cuff (WORC) index
: The aim of the study was to accomplish translation, cross-cultural adaptation and validation of the Western Ontario Rotator Cuff (WORC) Index questionnaire for its use in Italy. The WORC original version was translated and cross-culturally adapted into Italian. Subsequently, it was administered to a population of 60 patients suffering from rotator cuff disease to evaluate the validity and reliability of the Italian version. The content validity evaluated the correlation between questions and total score of each domain through Pearson's correlation coefficient. The construct validity was similarly assessed through Pearson's correlation coefficient by testing the correlation between the Italian WORC and the Italian version of the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Reliability was assessed using two methods: internal consistency by calculating the Cronbach's alpha coefficient for each domain; and test-retest by means of the intraclass correlation coefficient (ICC). The translation and cross-cultural adaptation of the Italian version did not reveal any major problems. No significant floor or ceiling effects were found. All the questions were linearly related to the concept expressed by the domain of belonging. Overall correlation with the DASH score was 0.75. Internal consistency was very high overall (α = 0.93) as well as reliability (overall ICC = 0.87). The Italian version of the WORC questionnaire is a valid and reproducible measuring instrument and can be considered a valid tool for the evaluation of the effectiveness of a treatment in terms of quality of life, in Italian patients affected by rotator cuff diseases.Level of evidence Diagnostic study, level II
Doxorubicin Hydrochloride-Loaded Nonionic Surfactant Vesicles to Treat Metastatic and Non-Metastatic Breast Cancer
Doxorubicin hydrochloride (DOX) is currently used to treat orthotropic and metastatic breast cancer. Because of its side effects, the use of DOX in cancer patients is sometimes limited; for this reason, several scientists tried designing drug delivery systems which can improve drug therapeutic efficacy and decrease its side effects. In this study, we designed, prepared, and physiochemically characterized nonionic surfactant vesicles (NSVs) which are obtained by self-assembling different combinations of hydrophilic (Tween 20) and hydrophobic (Span 20) surfactants, with cholesterol. DOX was loaded in NSVs using a passive and pH gradient remote loading procedure, which increased drug loading from ∼1 to ∼45%. NSVs were analyzed in terms of size, shape, size distribution, zeta potential, long-term stability, entrapment efficiency, and release kinetics, and nanocarriers having the best physiochemical parameters were selected for further in vitro tests. NSVs with and without DOX were stable and showed a sustained drug release up to 72 h. In vitro studies, with MCF-7 and MDA MB 468 cells, demonstrated that NSVs, containing Span 20, were better internalized in MCF-7 and MDA MB 468 cells than NSVs with Tween 20. NSVs increased the anticancer effect of DOX in MCF-7 and MDA MB 468 cells, and this effect is time and dose dependent. In vitro studies using metastatic and nonmetastatic breast cancer cells also demonstrated that NSVs, containing Span 20, had higher cytotoxicity than NSVs with Tween 20. The resulting data suggested that DOX-loaded NSVs could be a promising nanocarrier for the potential treatment of metastatic breast cancer
The southernmost beech (Fagus sylvatica) forests of Europe (Mount Etna, Italy): ecology, structural stand-type diversity and management implications
The southernmost European beech forests are located in the upper forest vegetation belt on Mount Etna volcano. Their standstructural
patterns were analysed to assess the effects of the site-ecological factors and previous management practices on the
forest structure. Five main structural-silvicultural types were identified among the main beech forest types: coppice, highmountain
coppice (HMCo), high forest, coppice in conversion to high-forest and non-formal stand. A detailed standstructural
analysis was carried out through measured dendrometric parameters and derived structural characters linked to
both the horizontal and the vertical profiles. Plant regeneration processes were also assessed, and several biodiversity
indicators were calculated. The collected data indicate a high variability of beech stand structures in relation to the
heterogeneity of the site-ecological characteristics as well as to the effects of both natural and anthropic disturbance factors.
The occurrence of particular stand structures along the altitude gradient on Mount Etna is evident. It is especially visible in
the multi-stemmed HMCos in relation to the changing, and increasingly limiting, ecological factors, although at higher
altitudes historical anthropic actions (felling) also have had an influence. Inside the Mediterranean area, these stands highlight
their ecological marginality, in terms of both latitude and altitude, especially regarding current climate change processes
How students perceive medical competences: a cross-cultural study between the Medical Course in Portugal and African Portuguese Speaking Countries
<p>Abstract</p> <p>Background</p> <p>A global effort has been made in the last years to establish a set of core competences that define the essential professional competence of a physician. Regardless of the environment, culture or medical education conditions, a set of core competences is required for medical practice worldwide. Evaluation of educational program is always needed to assure the best training for medical students and ultimately best care for patients. The aim of this study was to determine in what extent medical students in Portugal and Portuguese speaking African countries, felt they have acquired the core competences to start their clinical practice. For this reason, it was created a measurement tool to evaluate self-perceived competences, in different domains, across Portuguese and Portuguese-speaking African medical schools.</p> <p>Methods</p> <p>The information was collected through a questionnaire that defines the knowledge, attitudes and skills that future doctors should acquire. The Cronbach's Alpha and Principal Components Analysis (PCA) were used to evaluate the reliability of the questionnaire. In order to remove possible confounding effect, individual scores were standardized by country.</p> <p>Results</p> <p>The order of the domain's scores was similar between countries. After standardization, Personal Attitudes and Professional Behavior showed median scores above the country global median and Knowledge alone showed median score below the country global median. In Portugal, Clinical Skills showed score below the global median. In Angola, Clinical Skills and General Skills showed a similar result. There were only significant differences between countries in Personal Attitudes (p < 0.001) and Professional Behavior (p = 0.043).</p> <p>Conclusions</p> <p>The reliability of the instrument in Portuguese and Portuguese-speaking African medical schools was confirmed. Students have perceived their level of competence in personal attitudes in a high level and in opposite, knowledge and clinical skills with some weaknesses.</p
Dual practice in the health sector: review of the evidence
This paper reports on income generation practices among civil servants in the health sector, with a particular emphasis on dual practice. It first approaches the subject of public–private overlap. Thereafter it focuses on coping strategies in general and then on dual practice in particular. To compensate for unrealistically low salaries, health workers rely on individual coping strategies. Many clinicians combine salaried, public-sector clinical work with a fee-for-service private clientele. This dual practice is often a means by which health workers try to meet their survival needs, reflecting the inability of health ministries to ensure adequate salaries and working conditions. Dual practice may be considered present in most countries, if not all. Nevertheless, there is surprisingly little hard evidence about the extent to which health workers resort to dual practice, about the balance of economic and other motives for doing so, or about the consequences for the proper use of the scarce public resources dedicated to health. In this paper dual practice is approached from six different perspectives: (1) conceptual, regarding what is meant by dual practice; (2) descriptive, trying to develop a typology of dual practices; (3) quantitative, trying to determine its prevalence; (4) impact on personal income, the health care system and health status; (5) qualitative, looking at the reasons why practitioners so frequently remain in public practice while also working in the private sector and at contextual, personal life, institutional and professional factors that make it easier or more difficult to have dual practices; and (6) possible interventions to deal with dual practice
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