16 research outputs found

    Modular plastic chip for one-shot human papillomavirus diagnostic analysis.

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    In this article, we report the design and development of a plastic modular chip suitable for one-shot human papillomavirus (HPV) diagnostics, namely detection of the viral presence and relative genotyping, by two sequential steps performed directly on the same device. The device is composed of two modular and disposable plastic units that can be assembled or used separately. The first module is represented by a polydimethylsiloxane (PDMS) microreactor that is exploited for real-time polymerase chain reaction (PCR) and, thus, is suitable for detecting the presence of virus. The second unit is a PDMS microwell array that allows virus genotyping by a colorimetric assay, based on DNA hybridization technology developed on plastic, requiring simple inspection by the naked eye. The two modules can be easily coupled to reusable hardware, enabling the heating/cooling processes and the real-time detection of HPV. By coupling real-time assay and colorimetric genotyping on the same chip, the assembled device may provide a low-cost tool for HPV diagnostics, thereby favoring the prediction of cancer risk in patients

    Influence of carbon nanotubes structure on the mechanical behavior of cement composites

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    Cement matrix composites have been prepared by adding 0.5% in weight of multi wall carbon nanotubes (MWCNTs) to plain cement paste. In order to study how the chemical-physical properties of the nanotubes can affect the mechanical behavior of the composite, we compared the specimen obtained by mixing the same cement paste with three different kinds of MWCNTs. In particular, as-grown, annealed and carboxyl functionalized MWCNTs have been used. In fact, while high temperature annealing treatments remove lattice defects from the walls of CNTs, hence improving their mechanical strength, acid oxidative treatments increase chemical reactivity of pristine material, consequently chemical bonds between the reinforcement and the cement matrix are supposed to enhance the mechanical strength. Flexural and compressive tests showed a worsening in mechanical properties with functionalized MWCNTs, while a significant improvement is obtained with both as-grown and annealed MWCNTs. The phase composition of the composites was characterized by means of thermo gravimetric analysis coupled with mass spectroscopy, while the mineralogy and microstructure were analyzed by means of an X-ray diffractometer and scanning electron microscope. The results are interpreted and discussed taking into account the chemical and physical properties of the MWCNTs by means of EDX, TGA, SEM and Raman analysi

    The Role of Disordered Regions in Orchestrating the Properties of Multidomain Proteins: The SARS-CoV-2 Nucleocapsid Protein and Its Interaction with Enoxaparin

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    Novel and efficient strategies need to be developed to interfere with the SARS-CoV-2 virus. One of the most promising pharmaceutical targets is the nucleocapsid protein (N), responsible for genomic RNA packaging. N is composed of two folded domains and three intrinsically disordered regions (IDRs). The globular RNA binding domain (NTD) and the tethered IDRs are rich in positively charged residues. The study of the interaction of N with polyanions can thus help to elucidate one of the key driving forces responsible for its function, i.e., electrostatics. Heparin, one of the most negatively charged natural polyanions, has been used to contrast serious cases of COVID-19 infection, and we decided to study its interaction with N at the molecular level. We focused on the NTR construct, which comprises the NTD and two flanking IDRs, and on the NTD construct in isolation. We characterized this interaction using different nuclear magnetic resonance approaches and isothermal titration calorimetry. With these tools, we were able to identify an extended surface of NTD involved in the interaction. Moreover, we assessed the importance of the IDRs in increasing the affinity for heparin, highlighting how different tracts of these flexible regions modulate the interaction

    Carbon Nano beads (CNBs): a new ingredient in reinforcing materials

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    The on-going research on carbon nano beads (CNBs) are focusing on applications ranging from high strength composites, catalyst carriers, lubricants, electronic devices, weather resistant materials, molecular ball bearings, drug delivery vehicles (Bio-medical), semiconductors/transistors, high-capacity batteries and Hydrogen reservoir for the automotive industry. The commercial applications of CNBs are novel and yet immature for market. Experimental activity concerning a Research Program on Polymer-carbon nano tubes (CNTs) composite included also a limited number of test specimens prepared with CNBs. These specimens highlighted an increase in tensile strength visibly over the average results of the Polymer-CNTs composite tested in the same program. This result was considered indicative of a prospective CNBs adoption in new composites. Carbon group in Politecnico di Torino initiated an in-house small-scale research aimed to define and test a cost effective synthesis process of CNBs. The next step is the use of these CNBs in obtaining different kind of concretes and mortars, trying to enhance mechanical properties. The experimental tests on these materials are going to start during the redaction of the present pape

    Compositional Data Analysis of 16S rRNA Gene Sequencing Results from Hospital Airborne Microbiome Samples

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    The compositional analysis of 16S rRNA gene sequencing datasets is applied to characterize the bacterial structure of airborne samples collected in different locations of a hospital infection disease department hosting COVID-19 patients, as well as to investigate the relationships among bacterial taxa at the genus and species level. The exploration of the centered log-ratio transformed data by the principal component analysis via the singular value decomposition has shown that the collected samples segregated with an observable separation depending on the monitoring location. More specifically, two main sample clusters were identified with regards to bacterial genera (species), consisting of samples mostly collected in rooms with and without COVID-19 patients, respectively. Human pathogenic genera (species) associated with nosocomial infections were mostly found in samples from areas hosting patients, while non-pathogenic genera (species) mainly isolated from soil were detected in the other samples. Propionibacterium acnes, Staphylococcus pettenkoferi, Corynebacterium tuberculostearicum, and jeikeium were the main pathogenic species detected in COVID-19 patients’ rooms. Samples from these locations were on average characterized by smaller richness/evenness and diversity than the other ones, both at the genus and species level. Finally, the ρ metrics revealed that pairwise positive associations occurred either between pathogenic or non-pathogenic taxa
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