Tunable Knot Segregation in Copolyelectrolyte Rings Carrying a Neutral Segment

We use Langevin dynamics simulations to study the knotting properties of copolyelectrolyte rings carrying neutral segments. We show that by solely tuning the relative length of the neutral and charged blocks, one can achieve different combinations of knot contour position and size. Strikingly, the latter is shown to vary nonmonotonically with the length of the neutral segment; at the same time, the knot switches from being pinned at the block's edge to becoming trapped inside it. Model calculations relate both effects to the competition between two adversarial mechanisms: the energy gain of localizing one or more of the knot's essential crossings on the neutral segment and the entropic cost of such localization. Tuning the length of the neutral segment sets the balance between the two mechanisms and hence the number of localized essential crossings, which in turn modulates the knot's size. This general principle ought to be useful in more complex systems, such as multiblock copolyelectrolytes, to achieve a more granular control of topological constraints

Tuning Knotted Copolyelectrolyte Conformations via Solution Properties

We used Langevin dynamics simulations to study coarse-grained knotted copolyelectrolytes, composed by a neutral and a charged segment, in solutions of different salt concentrations, valency, and solvent screening power. We show that the facile variation of these parameters allows for tuning the length and position of the knotted region, which in turn controls the overall metric properties. Specifically, adding either monovalent or divalent ions causes the knot to swell at the expense of the copolyelectrolyte overall size. However, the knot typically straddles the charged-neutral interface in the presence of monovalent counterions, whereas it is attracted on the charged segment with divalent ones. Notably, similar modulations of knot size and position can also be achieved by varying the dielectric constant of the solvent. Our results demonstrate the feasibility of harnessing the solution-mediated balance of electrostatics and conformational entropy toward a facile external tuning of the conformational properties of knotted polymers

IMPATTO DI RINOVIRUS ED ENTEROVIRUS NELLA POLMONITE DI COMUNITÀ IN ETÀ PEDIATRICA: STUDIO DEI CEPPI VIRALI CIRCOLANTI E CORRELAZIONE CON IL QUADRO CLINICO.

Background: Community-acquired pneumonia (CAP) is one of the most important causes of childhood mortality in developing countries and, despite the availability of effective, preventive and therapeutic measures, remains a significant cause of morbidity and hospitalization in the industrialized world. Little in known about the prevalence of viral infections in children with CAP. Detailed information concerning the etiology of CAP in required in order to formulate treatment reccomendations and implement preventive measures. Evaluating the role played by each potential pathogen may also contribute to improving our understanding of the pathogenesis of the disease. Objectives: To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom samples from respiratory secretions were analyzed for 17 respiratory viruses. Patients and method: a nasopharyngeal swab was taken from children admitted to hospital because of CAP during five consecutive winter and early spring seasons (2007-2012). Samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV) -A and -B, parainfluenzavirus-1, -2, -3, and -4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus/rhinovirus (RV), and bocavirus. A real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to identify the RV in the enterovirus/RV positive swabs. Samples which were positive for RV were used for sequencing analysis and to reconstruct the phylogenetic tree. In addition, a total of twelve enterovirus C 104 (EV-C104) strains were analyzed for a complete genome sequence. Nasopharyngeal swabs positive for RSV and RV were analyzed by means of RT-PCR for autolysin-A and wzg genes of Streptooccus pneumoniae. Results: A total of 435 children (73,5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31,7%), followed by RV (n = 144, 24,3%), bocavirus (n = 60, 10,1%), influenza viruses (n = 57, 9,6%), and human metapneumovirus (n = 49, 8,2%). Viral co-infections were found in 117 children (19,7% of the enrolled children; 26,9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co-infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections. RV was identified in 198 samples (42.2%), and the VP4/VP2 region was successfully amplified in 151 (76.3%). RV-A was identified in 78 samples (51.6%), RV-B in 14 (9.3%) and HRV-C in 59 (39.1%). Forty-seven (31.1%) of the children with RV infection were aged <1 year, 71 (47.0%) were aged 1-3 years, and 33 (21.9%) were aged 654 years. Blast and phylogenetic analyses showed that the RV strains were closely related to a total of 66 reference genotypes, corresponding to 29 RV-A, 9 RV-B and 28 RV-C strains. The genome length of the seven strains was 7406 nucleotides (nt). The seven genomes showed 91.0\u201396.9% nucleotide identity with respect to other available EV-C104 complete genomes. The P1 and P2 regions of the Italian strains were closely related to EV-C104 identified in Switzerland, while the P3 region was closely related to the EV-C117 strain. Sixty-five ofthe 126 RSV-positive children (51,6%) were colonized with S. pneumoniae. Mean bacterial load was significantly higher in patients with alveolar involvement . Serotypes 5 and 19A were almost exclusively indentified in the children with RSV and alveolar CAP, although the difference was significant only for serotype 19A. Serotypes1, 5 and 19A were indentified in children with RV and alveolar CAP, although the difference was significant only for serotype 5. Conclusions: The findings of the study highlights the importance of respiratory viruses in children with CAP and show the characteristics of both single infections and co-infections associated with the disease. Moreover, this study shows that, RV-A, but also RV-B, and, more rarely, RV-C, can be detected in children with CAP. A large number of genotypes may be involved in causing pediatric CAP and can vary year to year. The same genotype can circulate for a prolonged period of time, being associated with a number of CAP episodes in different years. Regarding the genome characterization of EV-C104 strains, it was possible to establish the phylogenetic tree and to understand the relationship between the isolated strains and other known enterovirus C strains. The determination of nasopharyngeal pneumococcal bacterial load and identification of serotypes in children positive for RSV or RV infection, contribute to the diagnosis of mixed lung infection

High Photovoltaic Quantum Efficiency in Ultrathin van der Waals Heterostructures

We report experimental measurements for ultrathin (< 15 nm) van der Waals heterostructures exhibiting external quantum efficiencies exceeding 50%, and show that these structures can achieve experimental absorbance > 90%. By coupling electromagnetic simulations and experimental measurements, we show that pn WSe2/MoS2 heterojunctions with vertical carrier collection can have internal photocarrier collection efficiencies exceeding 70%.Comment: ACS Nano, 2017. Manuscript (25 pages, 7 figures) plus supporting information (7 pages, 4 figures

Life Cycle Assessment through BIM-based advanced Calculation Virtual Environment workflows

The current built stock in Europe is large and energetically inefficient due to material decay caused by lifelong use and lack of maintenance, combined. New buildings are commissioned and delivered everyday with an environmental cost, calculated using the Life Cycle Assessment methodology. The LCA is now widely requested for new assets, while existing ones are left for demolition and consequent carbon emissions released into the atmosphere, increasing the environmental crisis. In an effort to increase built stock's energy efficiency rates and decrease carbon emission, the recovery of these assets is depicted as the strategic next step for the construction sector. Both goals are achieved using data generated by dedicated construction software and processed in Calculation Virtual Environment, according to the specific needed data. The use of BIM for refurbishment design projects allows virtual construction separated by phases to simulate existing conditions of the envelope and its improvement with insulation material options. The use of one single file with clear phase definitions ensures data extraction and transference for all material options. The process is not entirely automated nevertheless it allows to save, use and share data whenever needed. The connection between data sources and databases in the cloud provides timesaving and regular updates. The research findings demonstrate the positive outcomes of modeling existing structures for energy simulation oriented to use in LCA, increasing the potential of BIM use in sensitive constructions while delivering appropriate results based on model and enriched geometry, with cost evaluation potential enabling scenario comparison for better decision making

SCAN-TO-BIM EFFICIENT APPROACH TO EXTRACT BIM MODELS FROM HIGH PRODUCTIVE INDOOR MOBILE MAPPING SURVEY

Building Information Modeling represents one of the most interesting developments in construction fields in the last 20 years. BIM process supports the creation of intelligent data that can be used throughout the life cycle of a construction project. Where a project involves a pre-existing structure, reality capture can provide the most critical information. The purpose of this paper is to describe an efficient approach to extract 3D models using high productive indoor Mobile Mapping Systems (iMMS) and an optimized scan-to-BIM workflow. The scan-to-BIM procedure allows reconstructing several elements within a digital environment preserving the features and reusing them in the development of the BIM project. The elaboration of the raw data acquired from the iMMS starts with the software HERON® Desktop where a SLAM algorithm runs and a 3D point cloud model is produced. The model is translated in the Gexcel Reconstructor® point cloud post processing software where a number of deliverables as orthophotos, blueprints and a filtered and optimized point cloud are obtained. In the proposed processing workflow, the data are introduced to Autodesk ReCap®, where the model can be edited and the final texturized point cloud model extracted. The identification and modeling of the 3D objects that compose the BIM model is realized in ClearEdge3D EdgeWiseTM and optimized in Autodesk Revit®. The data elaboration workflow implemented shows how an optimized data processing workflow allows making the scan-to-BIM procedure automatic and economically sustainable

Dynamic facial expressions of emotions are discriminated at birth

The ability to discriminate between different facial expressions is fundamental since the first stages of postnatal life. The aim of this study is to investigate whether 2-days-old newborns are capable to discriminate facial expressions of emotions as they naturally take place in everyday interactions, that is in motion. When two dynamic displays depicting a happy and a disgusted facial expression were simultaneously presented (i.e., visual preference paradigm), newborns did not manifest any visual preference (Experiment 1). Nonetheless, after being habituated to a happy or disgusted dynamic emotional expression (i.e., habituation paradigm), newborns successfully discriminated between the two (Experiment 2). These results indicate that at birth newborns are sensitive to dynamic faces expressing emotions

Real-time prediction of breast lesions displacement during Ultrasound scanning using a position-based dynamics approach.

Although ultrasound (US) images represent the most popular modality for guiding breast biopsy, they are sometimes unable to render malignant regions, thus preventing accurate lesion localization which is essential for a successful procedure. Biomechanical models can support the localization of suspicious areas identified on a pre-operative image during US scanning since they are able to account for anatomical deformations resulting from US probe pressure. We propose a deformation model which relies on position-based dynamics (PBD) approach to predict the displacement of internal targets induced by probe interaction during US acquisition. The PBD implementation available in NVIDIA FleX is exploited to create an anatomical model capable of deforming in real-time. In order to account for each patient\u2019s specificities, model parameters are selected as those minimizing the localization error of a US-visible landmark of the anatomy of interest (in our case, a realistic breast phantom). The updated model is used to estimate the displacement of other internal lesions due to probe-tissue interaction. The proposed approach is compared to a finite element model (FEM), generally used in breast biomechanics, and a rigid one. Localization error obtained when applying the PBD model remains below 11 mm for all the tumors even for input displacements in the order of 30 mm. The proposed method obtains results aligned with FE models with faster computational performance, suitable for real-time applications. In addition, it outperforms rigid model used to track lesion position in US-guided breast biopsies, at least halving the localization error for all the displacement ranges considered. Position-based dynamics approach has proved to be successful in modeling breast tissue deformations during US acquisition. Its stability, accuracy and real-time performance make such model suitable for tracking lesions displacement during US-guided breast biopsy

A position-based framework for the prediction of probe-induced lesion displacement in Ultrasound-guided breast biopsy

Although ultrasound (US) images represent the most popular modality for guiding breast biopsy, they are sometimes unable to render malignant regions, thus preventing accurate lesion localization which is essential for a successful procedure. Biomechanical models can support the localization of suspicious areas identified on a pre-operative image during US scanning since they are able to account for anatomical deformations resulting from US probe pressure. We propose a deformation model which relies on position-based dynamics (PBD) approach to predict the displacement of internal targets induced by probe interaction during US acquisition. The PBD implementation available in NVIDIA FleX is exploited to create an anatomical model capable of deforming online. Simulation parameters are initialized on a calibration phantom under different levels of probe-induced deformations, then they are fine-tuned by minimizing the localization error of a US-visible landmark of a realistic breast phantom. The updated model is used to estimate the displacement of other internal lesions due to probe-tissue interaction. The localization error obtained when applying the PBD model remains below 11 mm for all the tumors even for input displacements in the order of 30 mm. This approach outperforms rigid model used to track lesion position in US-guided breast biopsies, at least halving the localization error for all the displacement ranges considered. Position-based dynamics approach has proved to be successful in modeling breast tissue deformations during US acquisition. Its stability, accuracy and real-time performance make such model suitable for tracking lesions displacement during US-guided breast biopsy