105 research outputs found

    Insights into a Protein-Nanoparticle System by Paramagnetic Perturbation NMR Spectroscopy

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    BACKGROUND: The interaction between proteins and nanoparticles is a very relevant subject because of the potential applications in medicine and material science in general. Further interest derives from the amyloidogenic character of the considered protein, \u3b22-microglobulin (\u3b22m), which may be regarded as a paradigmatic system for possible therapeutic strategies. Previous evidence showed in fact that gold nanoparticles (AuNPs) are able to inhibit \u3b22m fibril formation in vitro. METHODS: NMR (Nuclear Magnetic Resonance) and ESR (Electron Spin Resonance) spectroscopy are employed to characterize the paramagnetic perturbation of the extrinsic nitroxide probe Tempol on \u3b22m in the absence and presence of AuNPs to determine the surface accessibility properties and the occurrence of chemical or conformational exchange, based on measurements conducted under magnetization equilibrium and non-equilibrium conditions. RESULTS: The nitroxide perturbation analysis successfully identifies the protein regions where protein-protein or protein-AuNPs interactions hinder accessibility or/and establish exchange contacts. These information give interesting clues to recognize the fibrillation interface of \u3b22m and hypothesize a mechanism for AuNPs fibrillogenesis inhibition. CONCLUSIONS: The presented approach can be advantageously applied to the characterization of the interface in protein-protein and protein-nanoparticles interactions

    Modeling rhizosphere carbon and nitrogen cycling in <i>Eucalyptus</i> plantation soil

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    Vigorous Eucalyptus plantations produce 105 to 106&thinsp;km&thinsp;ha−1 of fine roots that probably increase carbon (C) and nitrogen (N) cycling in rhizosphere soil. However, the quantitative importance of rhizosphere priming is still unknown for most ecosystems, including these plantations. Therefore, the objective of this work was to propose and evaluate a mechanistic model for the prediction of rhizosphere C and N cycling in Eucalyptus plantations. The potential importance of the priming effect was estimated for a typical Eucalyptus plantation in Brazil. The process-based model (ForPRAN – Forest Plantation Rhizosphere Available Nitrogen) predicts the change in rhizosphere C and N cycling resulting from root growth and consists of two modules: (1) fine-root growth and (2) C and N rhizosphere cycling. The model describes a series of soil biological processes: root growth, rhizodeposition, microbial uptake, enzymatic synthesis, depolymerization of soil organic matter, microbial respiration, N mineralization, N immobilization, microbial death, microbial emigration and immigration, and soil organic matter (SOM) formation. Model performance was quantitatively and qualitatively satisfactory when compared to observed data in the literature. Input variables with the most influence on rhizosphere N mineralization were (in order of decreasing importance) root diameter&thinsp; &gt; &thinsp;rhizosphere thickness&thinsp; &gt; &thinsp;soil temperature&thinsp; &gt; &thinsp;clay concentration. The priming effect in a typical Eucalyptus plantation producing 42&thinsp;m3&thinsp;ha−1&thinsp;yr−1 of shoot biomass, with assumed losses of 40&thinsp;% of total N mineralized, was estimated to be 24.6&thinsp;% of plantation N demand (shoot&thinsp;+&thinsp;roots&thinsp;+&thinsp;litter). The rhizosphere cycling model should be considered for adaptation to other forestry and agricultural production models where the inclusion of such processes offers the potential for improved model performance.</p

    The CRACK programme: a scientific alliance for bridging healthcare research and public health policies in Italy

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    Healthcare utilisation databases, and other secondary data sources, have been used with growing frequency to assess health outcomes and healthcare interventions worldwide. Their increased popularity as a research tool is due to their timely availability, the large patient populations covered, low cost, and applicability for studying real-world clinical practice. Despite the need to measure Italian National Health Service performance both at regional and national levels, the wealth of good quality electronic data and the high standards of scientific research in this field, healthcare research and public health policies seem to progress along orthogonal dimensions in Italy. The main barriers to the development of evidence-based public health include the lack of understanding of evidence-based methodologies by policy makers, and of involvement of researchers in the policy process. The CRACK programme was launched by some academics from the Lombardy Region. By extensively using electronically stored data, epidemiologists, biostatisticians, pharmacologists and clinicians applied methods and evidence to several issues of healthcare research. The CRACK programme was based on their intention to remove barriers that thwart the process of bridging methods and findings from scientific journals to public health practice. This paper briefly describes aim, articulation and management of the CRACK programme, and discusses why it might find articulated application in Italy

    Why do paediatricians prescribe antibiotics? Results of an Italian regional project

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    <p>Abstract</p> <p>Background</p> <p>To investigate determinants of antibiotic prescription in paediatric care, as a first step of a multilevel intervention to improve prescribing for common respiratory tract infections (RTIs) in a northern Italian region with high antibiotic prescription rate.</p> <p>Methods</p> <p>A two-step survey was performed: in phase I, knowledge, and attitudes were explored involving all family and hospital paediatricians of Emilia-Romagna and a sample of parents. In phase II, patient care practices were explored in a stratified random sample of visits, both in hospitals and family physician's clinics; parent expectations were investigated in a sub-sample of these visits.</p> <p>Results</p> <p>Out of overall 4352 visits for suspected RTIs, in 38% of children an antibiotic was prescribed. Diagnostic uncertainty was perceived by paediatricians as the most frequent cause of inappropriate prescription (56% of 633 interviewed paediatricians); but, rapid antigen detecting tests was used in case of pharyngitis/pharyngotonsillitis by 36% and 21% of family and hospital paediatricians only. More than 50% of paediatricians affirmed to not adopt a "wait and see strategy" in acute otitis. The perceived parental expectation of antibiotics was not indicated by paediatricians as a crucial determinant of prescription, but this perception was the second factor most strongly associated to prescription (OR = 12.8; 95% CI 10.4 - 15.8), the first being the presence of othorrea. Regarding parents, the most important identified factors, potentially associated to overprescribing, were the lack of knowledge of RTIs and antibiotics (41% of 1029 parents indicated bacteria as a possible cause of common cold), and the propensity to seek medical care for trivial infections (48% of 4352 children accessing ambulatory practice presented only symptoms of common cold).</p> <p>Conclusion</p> <p>A wide gap between perceived and real determinants of antibiotic prescription exists. This can promote antibiotic overuse. Inadequate parental knowledge can also induce inappropriate prescription. The value of this study is that it simultaneously explored determinants of antimicrobial prescribing in an entire region involving both professionals and parents.</p
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