575 research outputs found

    Fabrication of CZTSe/CIGS Nanowire Arrays by One-Step Electrodeposition for Solar-Cell Application

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    The paper reports some preliminary results concerning the manufacturing process of CuZnSnSe (CZTSe) and CuInGaSe (CIGS) nanowire arrays obtained by one-step electrodeposition for p-n junction fabrication. CZTSe nanowires were obtained through electrodeposition in a polycarbonate membrane by applying a rectangular pulsed current, while their morphology was optimized by appropriately setting the potential and the electrolyte composition. The electrochemical parameters, including pH and composition of the solution, were optimized to obtain a mechanically stable array of nanowires. The samples were characterized by scanning electron microscopy, Raman spectroscopy, and energy-dispersion spectroscopy. The nanostructures obtained showed a cylindrical shape with an average diameter of about 230 nm and a length of about 3 m, and were interconnected due to the morphology of the polycarbonate membrane. To create the p-n junctions, first a thin film of CZTSe was electrodeposited to avoid direct contact between the ZnS and Mo. Subsequently, an annealing process was carried out at 500 °C in a S atmosphere for 40 min. The ZnS was obtained by chemical bath deposition at 95 °C for 90 min. Finally, to complete the cell, ZnO and ZnO:Al layers were deposited by magnetron-sputtering

    Classi in rete. Un modello internazionale per innovare la didattica nelle piccole scuole

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    L’apprendimento a distanza rappresenta un grande potenziale per le piccole scuole,richiede perĂČ di ripensare la forme scolaireper queste ultime. Indire, in collaborazione con il Centre scolaire du Fleuve et des Lacs(MinistĂšre de l’éducation et de l’enseignement supĂ©rieur du QuĂ©bec), la Italian University Line (IUL), l’Ufficio Scolastico Regionale (USR) Abruzzo e un esperto dell’UniversitĂ  della Valle d’Aosta, ha promosso un intervento di formazione e sperimentazione per aiutare i docenti delle piccole scuole ad attuare il modello “Classi in rete”sviluppato dall’École Ă©loignĂ©e en RĂ©seau(Allaire et al.,2009) e basato sull’approccio teorico delle Knowledge Building Communities

    Screening for Gynecologic Conditions With Pelvic Examination US Preventive Services Task Force Recommendation Statement

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    IMPORTANCE Many conditions that can affect women\u27s health are often evaluated through pelvic examination. Although the pelvic examination is a common part of the physical examination, it is unclear whether performing screening pelvic examinations in asymptomatic women has a significant effect on disease morbidity and mortality. OBJECTIVE To issue a new US Preventive Services Task Force(USPSTF) recommendation on screening for gynecologic conditions with pelvic examination for conditions other than cervical cancer, gonorrhea, and chlamydia, for which the USPSTF has already made specific recommendations. EVIDENCE REVIEW The USPSTF reviewed the evidence on the accuracy, benefits, and potential harms of performing screening pelvic examinations in asymptomatic, nonpregnant adult women 18 years and older who are not at increased risk for any specific gynecologic condition. FINDINGS Overall, the USPSTF found inadequate evidence on screening pelvic examinations for the early detection and treatment of a range of gynecologic conditions in asymptomatic, nonpregnant adult women. CONCLUSIONS AND RECOMMENDATION The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of performing screening pelvic examinations in asymptomatic, nonpregnant adult women. (I statement) This statement does not apply to specific disorders for which the USPSTF already recommends screening (ie, screening for cervical cancer with a Papanicolaou smear, screening for gonorrhea and chlamydia)

    A biophysical approach to study an orphan disease: the case of CblC, a rare disorder of vitamin B12 intracellular metabolism

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    The cblC disease is an inborn disorder of the vitamin B12 (cobalamin, Cbl) metabolism. The affected children manifest devastating symptoms involving vision, growth, and learning. The illness is caused by mutations in the gene codifying for MMACHC, a protein that transports and transforms the different Cbl forms. Although the crystal structure of the wild-type (WT) protein is available, a systematic study on the effect of each specific mutation on the resulting protein is still lacking. Here we present data on the biophysical characterization of WT MMACHC, and two variants resulting from CblC pathological mutations. By using a biophysical approach including spectroscopy, Dynamic-Static Light and Small X-Ray Angle Scattering, and Molecular Dynamics, we investigated protein structure/stability and ability to bind and transform Cbl. Moreover, we evaluated whether drug-like molecules identified by computational methods, or non-specific stabilizers (osmolytes) could restore functionality in MMACHC mutants. Overall our results reveal how a biophysical approach can offer new insights in the study of CblC mutations' specific effect and help prospecting new routes for the CblC treatment

    Comparative study of the stabilities of synthetic in vitro and natural ex vivo transthyretin amyloid fibrils

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    Systemic amyloidosis caused by extracellular deposition of insoluble fibrils derived from the pathological aggregation of circulating proteins, such as transthyretin, is a severe and usually fatal condition. Elucidation of the molecular pathogenic mechanism of the disease and discovery of effective therapies still represents a challenging medical issue. The in vitro preparation of amyloid fibrils that exhibit structural and biochemical properties closely similar to those of natural fibrils is central to improving our understanding of the biophysical basis of amyloid formation in vivo and may offer an important tool for drug discovery. Here, we compared the morphology and thermodynamic stability of natural transthyretin fibrils with those of fibrils generated in vitro using either the common acidification procedure or primed by limited selective cleavage by plasmin. The free energies for fibril formation were -12.36 kcal mol-1, -8.10 kcal mol-1 and -10.61 kcal mol-1, respectively. The fibrils generated via plasmin cleavage were more stable than those prepared at low pH and were thermodynamically and morphologically similar to natural fibrils extracted from human amyloidotic tissue. Determination of thermodynamic stability is an important tool that is complementary to other methods for structural comparison between ex vivo fibrils and fibrils generated in vitro Our finding that fibrils created via an in vitro amyloidogenic pathway are structurally similar to ex vivo human amyloid fibrils does not necessarily establish that the fibrillogenic pathway is the same for both, but it narrows the current knowledge gap between in vitro models and in vivo pathophysiology

    Clobetasol promotes neuromuscular plasticity in mice after motoneuronal loss via sonic hedgehog signaling, immunomodulation and metabolic rebalancing

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    Motoneuronal loss is the main feature of amyotrophic lateral sclerosis, although pathogenesis is extremely complex involving both neural and muscle cells. In order to translationally engage the sonic hedgehog pathway, which is a promising target for neural regeneration, recent studies have reported on the neuroprotective effects of clobetasol, an FDA-approved glucocorticoid, able to activate this pathway via smoothened. Herein we sought to examine functional, cellular, and metabolic effects of clobetasol in a neurotoxic mouse model of spinal motoneuronal loss. We found that clobetasol reduces muscle denervation and motor impairments in part by restoring sonic hedgehog signaling and supporting spinal plasticity. These effects were coupled with reduced pro-inflammatory microglia and reactive astrogliosis, reduced muscle atrophy, and support of mitochondrial integrity and metabolism. Our results suggest that clobetasol stimulates a series of compensatory processes and therefore represents a translational approach for intractable denervating and neurodegenerative disorders

    measuring the reading abilities of dyslexic children through a visual game

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    In modern society about 10% of children suffer from a neuro-developmental disorder called dyslexia, which implies difficulties in learning to read. According to recent research, playing action videogames can be a valid teaching tool to improve the reading skills of dyslexic children through forms of engagement and interaction. This paper describes the design, implementation, validation and experimentation of an educational action game oriented to promote phonological and visuo-spatial attention training in dyslexic subjects aged between 7 and 9

    How communication affects prescription decisions in consultations for acute illness in children:a systematic review and meta-ethnography

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    BACKGROUND: Communication within primary care consultations for children with acute illness can be problematic for parents and clinicians, with potential misunderstandings contributing to over–prescription of antibiotics. This review aimed to synthesise the evidence in relation to communication and decision making in consultations for children with common acute illness. METHODS: A systematic search of MEDLINE, EMBASE, CINAHL, PsycINFO, SSCI, SIGLE, Dissertation Express and NHS economic evaluation databases was conducted. Studies of primary care settings in high income countries which made direct observations of consultations and reported qualitative data were included. Included studies were appraised using the process recommended by the Cochrane Qualitative Methods Group. Credibility was assessed as high for most studies but transferability was usually assessed low or unclear. Data were synthesised using a meta–ethnographic approach. RESULTS: Thirty–five papers and 2 theses reporting on 13 studies were included, 7 of these focussed on children with respiratory tract infections (RTI) and the remaining 6 included children with any presenting illness. Parent communication focussed on their concerns and information needs, whereas clinician communication focussed on diagnosis and treatment decisions. During information exchanges, parents often sought to justify the need for the consultation, while clinicians frequently used problem minimising language, resulting in parents and clinicians sometimes talking at cross–purposes. In the context of RTIs, a range of parent communication behaviours were interpreted by clinicians as indicating an expectation for antibiotics; however, most were ambiguous and could also be interpreted as raising concerns or requests for further information. The perceived expectation for antibiotics often changed clinician decision making into clinician–parent negotiation. CONCLUSIONS: Misunderstandings occurred due to parents and clinicians talking at cross purposes about the ‘seriousness’ of the illness and because parents’ expressions of concern or requests for additional information were sometimes perceived as a challenge to the clinicians’ diagnosis or treatment decision. This modifiable problem may be an important contribution to the unnecessary and unwanted prescribing of antibiotics. Primary care clinicians should be offered training to understand parent communication primarily as expressions of concern or attempts at understanding and always to check rather than infer parental expectations

    Plasmin activity promotes amyloid deposition in a transgenic model of human transthyretin amyloidosis

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    Cardiac ATTR amyloidosis, a serious but much under-diagnosed form of cardiomyopathy, is caused by deposition of amyloid fibrils derived from the plasma protein transthyretin (TTR), but its pathogenesis is poorly understood and informative in vivo models have proved elusive. Here we report the generation of a mouse model of cardiac ATTR amyloidosis with transgenic expression of human TTRS52P. The model is characterised by substantial ATTR amyloid deposits in the heart and tongue. The amyloid fibrils contain both full-length human TTR protomers and the residue 49-127 cleavage fragment which are present in ATTR amyloidosis patients. Urokinase-type plasminogen activator (uPA) and plasmin are abundant within the cardiac and lingual amyloid deposits, which contain marked serine protease activity; knockout of α2-antiplasmin, the physiological inhibitor of plasmin, enhances amyloid formation. Together, these findings indicate that cardiac ATTR amyloid deposition involves local uPA-mediated generation of plasmin and cleavage of TTR, consistent with the previously described mechano-enzymatic hypothesis for cardiac ATTR amyloid formation. This experimental model of ATTR cardiomyopathy has potential to allow further investigations of the factors that influence human ATTR amyloid deposition and the development of new treatments
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