30 research outputs found
Nanogap structures for molecular electronics and biosensing
No full textMolecular transport characterization is an active part of the research field in nanotechnology. In this interesting branch the self-assembly approach is highly exploited; it consists in spontaneous formation of highly ordered monolayers
on various substrate surfaces. Self-assembled monolayers (SAMs) have found their applications in various areas, such as nanoelectronics, surface engineering, biosensing, etc. An important area in biosensing is the electrochemical detection, that enables sensing of dierent biomarkers with an important role, for many dierent applications in biomedical diagnostics or in monitoring of biological systems. Various test structures have been developed in order to carry out characterizations of self-assembled molecules, and numerous reports have been published in the past several years on the transport characteristics.
This thesis' purpose is the single protein biomolecular sensing, that could become the starting point for monitoring drugs, developing clean energy systems,
realizing bio-opto-electronic transistors... The possibility to cover so many fields is related to the kind of proteins, molecules, bioelements that will be inserted inside sensors. Biomolecular sensing has to be thought in order to reach a result with the better compromise between instrumentation versatility and measurements precision. The main underlying idea is to use single molecules as active elements in nano-devices. As a consequence, the proper realization of a molecule-electrode contact is a crucial issue. What is needed by author is something versatile, precize, cheap, at single molecule level and able to record measurements in few time in order to do statistical characterizations. The final goal of this work is a platform system adapt for both industry and research field.
Electrical nanogap devices are the main character of this work. They have proven good performances as element for detecting small quantities of biomolecules, allowing direct transduction of biomolecular signals into useful
electrical ones such as resistance/impedance, capacitance/dielectric, or field effect. Nanogaps are now one of the most busy area of research in the nanotechnology world. Moreover, these structures do not require feedback to maintain the mutual arrangement (comparing with conducting tip AFM) and are less
stochastic with respect to electrochemical cells. Several techniques can be applied to nanogap fabrication: mechanically broken or positioned junctions, nano-scale lithography by Synchrotron radiation sources, electrochemical deposition and etching, and electromigration. None of these techniques is presently able to give precise control as to thefinal gap size. In this thesis the electromigration approach has been choosen, because of several useful characteristics. It is cost eective, because of the relatively low complexity of the required equipment. It can be embedded into a lab-on-chip
system, thus exploiting the possibility to tailor the gap formation process by means of a digital loop control system. To this end, it just requires a conventional microchip fabrication process. It allows the parallelization with a smart packaging through which it is possible to produce more probes at the same time and perform many measurements in contemporary. The employment of nanogaps, as an instrumentation for the molecular charac-
terization, has also some issues that have to be considered in order to obtain useful measurements. To characterize molecules the leakedge must be not higher than some pA to avoid the noise overcome the signal. Nanogap platform is perfect for molecular electronics. The experiments have been developed in dry way, as a consequence the solutions were evaporated before the measurement starting. This brought several problems cause biochemical analysis requires liquid solution in order to avoid an untimely death of the bio-elements tha has to be characterized. Considering a future developement, an improvement is necessary in terms of a system able to work with salty solutions without damaging the microchip's probes. Therefore it is a necessary a set-up allowing the anchorage
of a microfluidic part. At the same time it is necessary to keep in mind that the presence of a new system has to not overcome the molecule signal, maintaining the leakedge under some tens of pA
Nursing student plans for the future after graduation: a multicentre study
No full textBackground: When modelling the nursing workforce, estimations of the numbers and characteristics of new graduates over the forecast period are assumed on the basis of previous generations; however, new graduates may have different plans for their future than those documented previously in different socio-economical contexts. Aims: To explore (a) nursing student plans after graduation and factors influencing their plans, and (b) factors associated with the intention to emigrate. Methods: A survey questionnaire was developed and distributed to students attending their final third year of nursing education in seven universities in Italy in 2015. Nine hundred and twenty-three (90.4%) students participated. Findings: Four different plans after graduation emerged: about two-thirds reported an intention to look for a nursing job in Italy; the remaining reported (a) an intention to emigrate, looking for a nursing job abroad, (b) an intention to search for a nursing job in both Italy and abroad, and (c) while a few an intention to continue nursing education in Italy. Having previous experience abroad, the need to grow and be satisfied, trusting the target country and a desire to increase knowledge encouraged an intention to emigrate, whereas the desire to stay in a comfortable environment and nurture personal relationships prevented the desire to migrate. Conclusion: Nursing students may have different plans after graduation, and this should be considered when modelling the nursing workforce of the future. Implications for nursing/health policy: Policymakers should be aware of different plans after graduation to guide healthcare human resource strategies. Knowing these trajectories allows policymakers to estimate the appropriate nursing workforce, and also to act at both macro- and meso-levels, on work environments and opportunities for professional development, according to the different levels of expectations
Social isolation from early life induces anxiety-like behaviors in adult rats: Relation to neuroendocrine and neurochemical dysfunctions
No full textSubjects suffering from psychosis frequently experience anxiety. However, mechanisms underlying this comorbidity remain still unclear. We investigated whether neurochemical and neuroendocrine dysfunctions were involved in the development of anxiety-like behavior in a rodent model of psychotic-like symptoms, obtained by exposing male rats to social isolation rearing from postnatal day 21 to postnatal day 70. In the elevated zero maze test, isolated rats showed a significant reduction in the time spent in the open arms, as well as an increase in the time spent in the closed arms, compared to controls. An increased grooming time in the open field test was also observed in isolated animals. Isolation-induced anxiety-like behavior was accompanied by a decrease of plasmatic oxytocin, prolactin, ghrelin and melatonin levels, whereas plasmatic amount of Neuropeptide S was not altered. Social isolation also caused a reduction of noradrenaline, serotonin and GABA levels, together with an increase of serotonin turnover and glutamate levels in the amygdala of isolated animals. No significant differences were found in noradrenaline and serotonin levels, as well as in serotonin turnover in hippocampus, while glutamate amount was increased and GABA levels were reduced in isolated rats. Furthermore, there was a reduction in plasmatic serotonin content, and an increase in plasmatic kynurenine levels following social isolation, while no significant changes in serotonin turnover were observed. Taken together, our data provide novel insights in the neurobiological alterations underlying the comorbidity between psychosis and anxiety, and open new perspectives for multi-target therapies acting on both neurochemical and neuroendocrine pathways. Data availability statement: The data presented in this study are available on request from the corresponding author
P112 Cytokine driven disease and epigenetic heterogeneity in rheumatoid arthritis
No full textAbstract citation ID: keaf142.152Background/Aims : Therapies that target cytokine signals have revolutionised the treatment of immune-mediated inflammatory diseases. However, many patients show an inadequate response to particular drug classes, reflecting the complex and often heterogeneous nature of pathology. In rheumatoid arthritis, synovial biopsies display a broad range of cellular and molecular hallmarks of disease that classify the occurrence of myeloid-rich, fibroblast-rich, and lymphoid-rich synovitis. It is unclear whether these differences in immune pathology reflect individual disease processes or different stages in disease progression. Studies of synovial histopathology in antigen-induced arthritis (AIA) showed that Il6ra-/- mice develop a low-inflammatory pathology (lacking an immune cell infiltrate) resembling fibroblast-rich synovitis. This pathology contrasted with AIA in WT mice, which presented with a myeloid-rich inflammatory infiltrate and Il27ra-/- mice, where synovial ectopic lymphoid-like structures (ELS) resembled lymphoid-rich synovitis.Stuart T O Hughes, Daniela Costa, Alicia Derrac Soria, David Hill, Ana Cardus Figueras, Reuben Scott, Sandra Dimonte, Federica Monaco, Robert Jenkins, Jason Twohig, Carol Guy, Ben Cossins, Robert Andrews, Barbara Szomolay, Ernest Choy, Ngoc-Nga Vinh, Myles Lewis, Brendan Jenkins, Stephen Turner, Tony Tiganis, Nigel Williams, Hua Yu, Constantino Pitzalis, Gareth Jones, Simon A Jone
Clinical Learning Quality Evaluation Index per la valutazione della qualità dell’apprendimento clinico degli studenti infermieri e raccomandazioni di utilizzo
No full textMucosal T-cell responses to chronic viral infections: Implications for vaccine design
No full textMucosal surfaces that line the respiratory, gastrointestinal and genitourinary tracts are the major interfaces between the immune system and the environment. Their unique immunological landscape is characterized by the necessity of balancing tolerance to commensal microorganisms and other innocuous exposures against protection from pathogenic threats such as viruses. Numerous pathogenic viruses, including herpesviruses and retroviruses, exploit this environment to establish chronic infection. Effector and regulatory T-cell populations, including effector and resident memory T cells, play instrumental roles in mediating the transition from acute to chronic infection, where a degree of viral replication is tolerated to minimize immunopathology. Persistent antigen exposure during chronic viral infection leads to the evolution and divergence of these responses. In this review, we discuss advances in the understanding of mucosal T-cell immunity during chronic viral infections and how features of T-cell responses develop in different chronic viral infections of the mucosa. We consider how insights into T-cell immunity at mucosal surfaces could inform vaccine strategies: not only to protect hosts from chronic viral infections but also to exploit viruses that can persist within mucosal surfaces as vaccine vectors
Strumento di Valutazione Italiano degli Ambienti di Tirocinio per gli studenti infermieri (SVIAT): protocollo di validazione [Validation of the Italian Clinical Learning Environment Instrument (SVIAT): study protocol]
No full textIntroduzione. Gli studenti dei Corsi di laurea in Infermieristica ottengono buona parte dei loro crediti formativi negli ambienti di tirocinio, la cui qualità può influenzare l'apprendimento clinico. Gli strumenti disponibili per misurare la qualità dell'ambiente di apprendimento così come percepita dagli studenti, sviluppati in altri paesi e validati in Italia, non sembrano in grado di indicare tirocini dove gli studenti effettivamente apprendono (o meno) e, quindi, supportare le decisioni rispetto a quali sedi accreditare. Obiettivi. Validare uno strumento per misurare la capacità di un ambiente di tirocinio di generare apprendimento significativo; obiettivo secondario è descrivere gli ambienti di apprendimento, così come percepiti dagli studenti infermieri italiani in base a variabili individuali, di percorso accademico, di contesto e di modelli tutoriali. Metodi. Lo studio è articolato in tre fasi: a) sviluppo dello strumento e fase pilota, b) validazione delle proprietà psicometriche dello strumento, c) descrizione degli ambienti di apprendimento così come percepiti dagli studenti includendo fattori/item confermati nel processo di validazione. Esiti attesi. Validazione dello strumento su più di 8.000 studenti; il costrutto che lo strumento intende misurare sarà confermato attraverso analisi fattoriale esplorativa e confermativa e riporterà una elevata consistenza interna; lo strumento riporterà una elevata affidabilità test-retest e intervalutatore; inoltre, avrà capacità predittive individuando le sedi che sono (o non) in grado di attivare processi di apprendimento significativi
The Italian instrument evaluating the nursing students clinical learning quality
No full textIntroduzione. I Corsi di Studio in Infermieristica (CdSI) Italiani hanno bisogno di strumenti di valutazione dei tirocini per raccogliere le opinioni degli studenti. Esistono diversi strumenti per valutare la qualità degli ambienti di tirocinio clinico; tuttavia, molti hanno dei limiti e non misurano la qualità dell’apprendimento. Obiettivo. È stato avviato un progetto di ricerca nazionale per disegnare e validare uno strumento capace di misurare quanto un contesto di tirocinio è in grado di generare apprendimenti significativi. Metodi. Studio di validazione. A tutte le sedi di CdSI italiane, dal 2015 al 2016, è stato chiesto di somministrare agli studenti che avevano concluso o appena concluso un tirocinio un questionario che includeva un set di item identificati attraverso la revisione della letteratura, la consultazione di strumenti usati in altri ambiti e paesi, e il parere di esperti tra i quali anche studenti. Sui questionari raccolti sono state condotte analisi per valutarne le proprietà psicometriche. Risultati. Hanno partecipato 9606 studenti infermieri di 27 sedi universitarie italiane sulle 43 (62.8%). Le proprietà psicometriche dello strumento sono risultate da buone a eccellenti: lo strumento finale è composto da 22 item e 5 fattori: a) qualità delle strategie tutoriali, b) opportunità di apprendimento; c) sicurezza e qualità dell’assistenza; d) auto-apprendimento; e) qualità dell’ambiente di apprendimento. Conclusioni. Lo strumento, già utilizzato in molte sedi, potrà costituire la base di confronto tra sedi cliniche di uno stesso corso e tra corsi di studio diversi; potrà aiutare nella valutazione degli effetti delle strategie di miglioramento attivate e nell’ individuazione del fabbisogno formativo dei tutor/assistenti di tirocinio
T‐cell memory formation following subcutaneous cytomegalovirus infection requires virus replication but not early dendritic cell responses
No full textCytomegalovirus (CMV) induction of large frequencies of highly functional memory T-cells has attracted much interest in the utility of CMV-based vaccine vectors, with exciting preclinical data obtained in models of infectious diseases and cancer. However, pathogenesis of human CMV (HCMV) remains a concern. Attenuated CMV-based vectors, such as replication- or spread-deficient viruses potentially offer an alternative to fully replicating vectors. However, it is not well-understood how CMV attenuation impacts vector immunogenicity, in particularly when administered via relevant routes of immunization such as the skin. Herein we used the murine cytomegalovirus (MCMV) model to investigate the impact of vector attenuation on T-cell memory formation following subcutaneous administration. We found that the spread deficient virus (ΔgL-MCMV) was impaired in its ability to induce memory CD8+ T-cells reactive to some (M38, IE1) but not all (IE3) viral antigens. Impaired memory T-cell development was associated with a preferential and pronounced loss of polyfunctional (IFN-γ+ TNF-α+) T-cells and also reduced accumulation of TCF1+ T-cells, and was not rescued by increasing the dose of replication-defective MCMV. Finally, whilst vector attenuation reduced dendritic cell (DC) recruitment to skin-draining lymph nodes, systematic depletion of multiple DC subsets during acute subcutaneous MCMV infection had a negligible impact on T-cell memory formation, implying that attenuated responses induced by replication-deficient vectors were likely not a consequence of impaired initial DC activation. Thus, overall, these data imply that the choice of antigen and/or cloning strategy of exogenous antigen in combination with the route of immunization may influence the ability of attenuated CMV vectors to induce robust functional T-cell memory
No correlation of FACS and <i>var</i> signals in MOA bulk and clones at >65 generations.
No full text(A) The MOA bulk culture exhibits low var gene transcription signals, but a high MFI (201). (B) Clone D2 exhibits the highest MFI (489) in the entire population and high var gene transcription signals for transcripts P_D2 and D2_18. (C) and (D) Clones D5 and C3 display low var gene transcription signals but show MFIs in the medium range (MFI of 63.67 and 139.67 respectively).</p
