249 research outputs found

    Detecting Mutations in the Mycobacterium tuberculosis Pyrazinamidase Gene pncA to Improve Infection Control and Decrease Drug Resistance Rates in Human Immunodeficiency Virus Coinfection.

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    Hospital infection control measures are crucial to tuberculosis (TB) control strategies within settings caring for human immunodeficiency virus (HIV)-positive patients, as these patients are at heightened risk of developing TB. Pyrazinamide (PZA) is a potent drug that effectively sterilizes persistent Mycobacterium tuberculosis bacilli. However, PZA resistance associated with mutations in the nicotinamidase/pyrazinamidase coding gene, pncA, is increasing. A total of 794 patient isolates obtained from four sites in Lima, Peru, underwent spoligotyping and drug resistance testing. In one of these sites, the HIV unit of Hospital Dos de Mayo (HDM), an isolation ward for HIV/TB coinfected patients opened during the study as an infection control intervention: circulating genotypes and drug resistance pre- and postintervention were compared. All other sites cared for HIV-negative outpatients: genotypes and drug resistance rates from these sites were compared with those from HDM. HDM patients showed high concordance between multidrug resistance, PZA resistance according to the Wayne method, the two most common genotypes (spoligotype international type [SIT] 42 of the Latino American-Mediterranean (LAM)-9 clade and SIT 53 of the T1 clade), and the two most common pncA mutations (G145A and A403C). These associations were absent among community isolates. The infection control intervention was associated with 58-92% reductions in TB caused by SIT 42 or SIT 53 genotypes (odds ratio [OR] = 0.420, P = 0.003); multidrug-resistant TB (OR = 0.349, P < 0.001); and PZA-resistant TB (OR = 0.076, P < 0.001). In conclusion, pncA mutation typing, with resistance testing and spoligotyping, was useful in identifying a nosocomial TB outbreak and demonstrating its resolution after implementation of infection control measures

    Immersive virtual reality as a tool for lighting design: Applications and opportunities

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    Immersive virtual reality offers a wide range of applications. Immersive virtual reality in particular can play an important role in lighting design, thanks to its ability to allow a quick assessment between different design choices based on spaces, colours and light. However, immersive virtual reality has to guarantee a correct reproduction of light behaviour from photometric and visual points of view, in order to be effectively used for lighting analysis. This paper presents a literature review aimed to analyse the activities of the research groups operating in this field that have addressed, with different approaches and points of view, the issue of iVR applications in the reproduction of environments illuminated by either daylight or electric lighting, as well as a combination of them

    Suspended transport of gravel in rivers: Empirical evidence from the 2022 flood in the Misa River (Eastern Apennines, Italy)

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    In September 2022, an exceptional flood in the Misa River basin (Eastern Apennines, Italy) resulted in the unusual deposition of gravelly lobes on terraces up to 6 m higher than the riverbed. These deposits suggest that coarse bed sediments were transported in suspension rather than as bedload, as typically occurs under competent flow conditions. To verify this hypothesis, we combined field evidence-obtained from geomorphological and sedimentological surveys-with theoretical insights based on sediment transport theory. Our findings indicate that medium-sized gravels, which are part of the riverbed material, were transported in suspension within the water column. This phenomenon required specific conditions to generate the necessary shear stress and energy, including (i) a high-magnitude flood enriched with fine sediments, which increased the fluid density and viscosity, and (ii) an entrenched channel with stable banks that limited channel widening during the flood event. When these processes coincided with alluvial plain inundation by overbank flows, gravel transported in suspension was able to reach and settle on elevated surfaces, such as terraces far above the active channel. These observations highlight the potential for gravel-bed rivers to support the transport of coarse sediment in suspension under extreme flood conditions and specific geomorphological constraints on the active river channels. By demonstrating the role of sediment concentration, channel morphology and flood dynamics, our research provides new insights into sediment transport mechanisms and contributes to a broader understanding of the morphodynamic processes governing gravel-bed rivers under such exceptional conditions, with broad implications for refining flood hazard models and improving sediment transport predictions in fluvial systems

    Suspended transport of gravel in rivers: Empirical evidence from the 2022 flood in the Misa River (Eastern Apennines, Italy)

    Get PDF
    In September 2022, an exceptional flood in the Misa River basin (Eastern Apennines, Italy) resulted in the unusual deposition of gravelly lobes on terraces up to 6 m higher than the riverbed. These deposits suggest that coarse bed sediments were transported in suspension rather than as bedload, as typically occurs under competent flow conditions. To verify this hypothesis, we combined field evidence—obtained from geomorphological and sedimentological surveys—with theoretical insights based on sediment transport theory. Our findings indicate that medium-sized gravels, which are part of the riverbed material, were transported in suspension within the water column. This phenomenon required specific conditions to generate the necessary shear stress and energy, including (i) a high-magnitude flood enriched with fine sediments, which increased the fluid density and viscosity, and (ii) an entrenched channel with stable banks that limited channel widening during the flood event. When these processes coincided with alluvial plain inundation by overbank flows, gravel transported in suspension was able to reach and settle on elevated surfaces, such as terraces far above the active channel. These observations highlight the potential for gravel-bed rivers to support the transport of coarse sediment in suspension under extreme flood conditions and specific geomorphological constraints on the active river channels. By demonstrating the role of sediment concentration, channel morphology and flood dynamics, our research provides new insights into sediment transport mechanisms and contributes to a broader understanding of the morphodynamic processes governing gravel-bed rivers under such exceptional conditions, with broad implications for refining flood hazard models and improving sediment transport predictions in fluvial systems

    Energy performances assessment of extruded and 3d printed polymers integrated into building envelopes for a south Italian case study

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    Plastic materials are increasingly becoming used in the building envelope, despite a lack of investigation on their effects. In this work, an extruded Acrylonitrile-Butadiene-Styrene panel has been tested as a second-skin layer in a ventilated facade system using a full-scale facility. The experimental results show that it is possible to achieve performances very similar to conventional materials. A numerical model has then been developed and used to investigate the performances of plastic and composite polymer panels as second-skin layers. The experimental data has been used to verify the behavior of the numerical model, from a thermal point of view, showing good reliability, with a root mean square error lower than 0.40◦C. This model has then been applied in different refurbishment cases upon varying: The polymer and the manufacturing technology (extruded or 3D-printed panels). Eight refurbishment case studies have been carried out on a typical office building located in Napoli (Italy), by means of a dynamic simulation software. The simulation results show that the proposed actions allow the reduction of the thermal and cooling energy demand (up to 6.9% and 3.1%, respectively), as well as the non-renewable primary energy consumption (up to 2.6%), in comparison to the reference case study

    Synergic use of botulinum toxin injection and radial extracorporeal shockwave therapy in multiple sclerosis spasticity

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    Background and aim: In Multiple Sclerosis (MS) spasticity worsens the patient’s quality of life. Botulinum NeuroToxin TypeA (BoNT-A) is extensively used in focal spasticity, frequently combined with physical therapies. Radial extracorporeal shock waves (rESW) were already used in association with BoNTA. Considering that loss of efficacy and adverse events are determinants of BoNT-A treatment interruption, this study aimed to evaluate the possibility to prolong BoNT-A’s effect by using rESW in MS focal spasticity. Methods: Sixteen MS patients with spasticity of triceps surae muscles were first subjected to BoNT-A therapy and, four months later, to 4 sections of rESWT. Patients were evaluated before, 30, 90 days after the end of the treatments, by using Modified Ashworth Scale (MAS), Modified Tardieu Scale (MTS), and kinematic analysis of passive and active ankle ROM. Results: BoNT-A determined a significant reduction of spasticity evaluated by MAS with a reduction of positive effects after 4months (p&lt;0.05); MTS highlighted the efficacy only 90 days after injection (p&lt;0.05). rESWT decreased MAS values at the end and 30 days later the treatment (p&lt;0.01); MTS values showed instead a prolonged effect (p&lt;0.01). BoNT-A determined a gain of passive and active ankle ROM, persisting along with treatment and peaking the maximum value after rESWT (p&lt;0.05). Conclusions: rESWT can prolong BoNT-A effect inducing a significant reduction of spasticity and improvement in passive and active ankle ROM in MS patients. The use of rESWT following BoNT-A injection is useful to avoid some limitations and to prolong the therapeutic effects of BoNT-A therapy. (www.actabiomedica.it)

    Bacteriophage-encoded depolymerases: their diversity and biotechnological applications

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    Bacteriophages (phages), natural enemies of bacteria, can encode enzymes able to degrade polymeric substances. These substances can be found in the bacterial cell surface, such as polysaccharides, or are produced by bacteria when they are living in biofilm communities, the most common bacterial lifestyle. Consequently, phages with depolymerase activity have a facilitated access to the host receptors, by degrading the capsular polysaccharides, and are believed to have a better performance against bacterial biofilms, since the degradation of extracellular polymeric substances by depolymerases might facilitate the access of phages to the cells within different biofilm layers. Since the diversity of phage depolymerases is not yet fully explored, this is the first review gathering information about all the depolymerases encoded by fully sequenced phages. Overall, in this study, 160 putative depolymerases, including sialidases, levanases, xylosidases, dextranases, hyaluronidases, peptidases as well as pectate/pectin lyases, were found in 143 phages (43 Myoviridae, 47 Siphoviridae, 37 Podoviridae, and 16 unclassified) infecting 24 genera of bacteria. We further provide information about the main applications of phage depolymerases, which can comprise areas as diverse as medical, chemical, or food-processing industry.DPP acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/76440/2011. SS is an FCT investigator (IF/01413/2013). The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)

    Passive Strategies for Building Retrofitting: Performances Analysis and Incentive Policies for the Iranian Scenario

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    A large amount of the Iranian energy demand is related to the building sector, mainly due to its obsolescence. In this paper, a second-skin system has been implemented as a retrofit action for an office building, evaluating the effect of a tensile material as second-skin in terms of primary energy saving, carbon dioxide equivalent emissions, and simple payback period. The analysis was carried out through numerical simulations across a whole year and for four Iranian cities (Tabriz, Teheran, Yazd, and Bandar Abbas) in four different climates (cold, temperate, hot-dry, and hot-wet), and with the building aligned at either north-south or east-west. Moreover, an economic analysis was carried out suggesting different incentive policies to promote building energy refurbishment. The simulation results highlighted a favorable orientation for buildings in Iran, suggesting a guideline for new constructions. Indeed, the best results were achieved for an east-west orientation of the building (up to a primary energy saving of 13.6% and reduction of carbon dioxide equivalent emissions of 45.5 MgCO2,eq, in Yazd), with a decrease of the annual specific total (cooling and thermal) energy demand of 37.9 kWh/m2 /year. The simple payback period values were also lower in the east-west orientation than the north-south one
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