129 research outputs found

    Geometry-based customization of bending modalities for 3D-printed soft pneumatic actuators

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    In this work, we propose a novel type of 3D-printed soft pneumatic actuator that allows geometry-based customization of bending modalities. While motion in the 3D-space has been achieved for several types of soft actuators, only 2D-bending has been previously modelled and characterized within the scope of 3D-printed soft pneumatic actuators. We developed the first type of 3D-printed soft pneumatic actuator which, by means of the unique feature of customizable cubes at an angle with the longitudinal axis of the structure, is capable of helical motion. Thus, we characterize its mechanical behavior and formulate mathematical and FEA models to validate the experimental results. Variation to the pattern of the inclination angle along the actuator is then demonstrated to allow for complex 3D-bending modalities and the main applications in the fields of object manipulation and wearable robotics are finally discussed

    Shelf life evaluation of fresh-cut red chicory subjected to different minimal processes

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    Microbiological, chemical and physical parameters of minimally processed red chicory (Cichorium intybus L.) subjected to two different transformation processes were investigated. A classic ready-to-eat (RTE) process (P1) and a production without cutting (P2) were monitored during refrigerated (4 °C) storage (15 d). Total mesophilic microorganisms, total psychrotrophic microorganisms and pseudomonads were detected at the highest cell densities in all samples. Presumptive Pseudomonas population dominated the cultivable microbial community of RTE red chicory and were characterized genetically. Twenty-two randomly amplified polymorphic DNA (RAPD) types were investigated by 16S rRNA gene sequencing, resulting in members of Rahnella and Pseudomonas. The identification of Pseudomonas species was further determined by sequencing of gyrB, rpoB and rpoD genes resulting in 16 species. A highest visual quality and a lower weight loss and colour variation were registered for P2, while soluble solid, nitrate and ascorbic acid contents were not affected by processing and storage. The integrated microbiological, chemical and physical approach applied in this study demonstrated the longer shelf-life of P2 red chicory

    Non-commutability of results of highly sensitive troponin I and T immunoassays

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    Introduction: The measurement of cardiospecific troponins is pivotal in the diagnostic and prognostic approach of patients with suspected acute myocardial infarction (AMI). However, no information is available on the commutability of results between the novel highly-sensitive (HS) troponin T (TnT) and I (TnI) immunoassays. Materials and methods: The study population consisted in 47 consecutive patients presenting at the emergency department (ED) of the Academic Hospital of Parma with suspected AMI. TnI was measu-red with the novel prototype Beckman Coulter HS-AccuTnI immunoassay on Access 2, whereas TnT was measured with the Roche HS-TnT immunoassay on Cobas. Results: Eight out of the 47 patients (17%) were finally diagnosed as having an AMI. The overall cor-relation between TnT and TnI for total patient group was acceptable (r = 0.944; P < 0.01). Neverthe-less, when the analysis of data was carried out in separate groups according to the final diagnosis of AMI, two different equation results were obtained, i.e., HS-TnT = HS-AccuTnI x 0.349 + 20 (r = 0.823; P < 0.01) in non-AMI patients, and HS-TnT = HS-AccuTnI x 0.134 + 67 (r = 0.972; P < 0.01) in those with AMI. Conclusions: This study suggests the existence of two biological relationships between TnI and TnT in plasma, depending on the source of release from the myocardium. Moreover, the non-commutability of data between HS-TnT and HS-AccuTnI jeopardizes the clinical decision making, makes it impossible to calculate the delta or reference change value using the two biomarkers and to finally establish a reliable kinetics of troponin release from the injured myocardium

    Exploring the Predictability of EEG Signals Timed with the Heartbeat: A Model-Based Approach for the Temporal and Spatial Characterization of the Brain Dynamics

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    This study aims to provide a temporal and spatial characterization of the human brain activity related to the cardiac cycle in terms of regularity of the brain wave amplitudes measured from electroencephalographic (EEG) signals. To achieve this objective, linear autoregressive models are employed to characterize time-series of the spectral power extracted from EEG signals, timed with the heartbeat, by using a measure of predictability. The analysis is performed on four different timeseries acquired on healthy subjects in a resting state and describing the EEG spectral content over the whole frequency spectrum and within the θ, α and β bands. Our results indicate predictability values with targeted activations in the frontal and parieto-occipital brain regions, which reflect regular amplitude modulations of the brain waves at rest, and could be linked to the cortical processing of the heartbeat

    Comparative study of gene set enrichment methods

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    <p>Abstract</p> <p>Background</p> <p>The analysis of high-throughput gene expression data with respect to sets of genes rather than individual genes has many advantages. A variety of methods have been developed for assessing the enrichment of sets of genes with respect to differential expression. In this paper we provide a comparative study of four of these methods: Fisher's exact test, Gene Set Enrichment Analysis (GSEA), Random-Sets (RS), and Gene List Analysis with Prediction Accuracy (GLAPA). The first three methods use associative statistics, while the fourth uses predictive statistics. We first compare all four methods on simulated data sets to verify that Fisher's exact test is markedly worse than the other three approaches. We then validate the other three methods on seven real data sets with known genetic perturbations and then compare the methods on two cancer data sets where our a priori knowledge is limited.</p> <p>Results</p> <p>The simulation study highlights that none of the three method outperforms all others consistently. GSEA and RS are able to detect weak signals of deregulation and they perform differently when genes in a gene set are both differentially up and down regulated. GLAPA is more conservative and large differences between the two phenotypes are required to allow the method to detect differential deregulation in gene sets. This is due to the fact that the enrichment statistic in GLAPA is prediction error which is a stronger criteria than classical two sample statistic as used in RS and GSEA. This was reflected in the analysis on real data sets as GSEA and RS were seen to be significant for particular gene sets while GLAPA was not, suggesting a small effect size. We find that the rank of gene set enrichment induced by GLAPA is more similar to RS than GSEA. More importantly, the rankings of the three methods share significant overlap.</p> <p>Conclusion</p> <p>The three methods considered in our study recover relevant gene sets known to be deregulated in the experimental conditions and pathologies analyzed. There are differences between the three methods and GSEA seems to be more consistent in finding enriched gene sets, although no method uniformly dominates over all data sets. Our analysis highlights the deep difference existing between associative and predictive methods for detecting enrichment and the use of both to better interpret results of pathway analysis. We close with suggestions for users of gene set methods.</p

    Zoonotic infectious diseases in transplanted immunocompromised patients

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    Background. Immunocompromised patients, like transplant recipients, are a particularly vulnerable group being at higher risk of developing several infectious diseases. Among them, zoonotic diseases, such as visceral leishmaniasis, bartonellosis, Q fever and leptospirosis are a growing concern in immunosuppressed patients as they are more susceptible to develop severe symptoms of the diseases. Objectives. The study aimed at the detection of Leishmania infantum, Bartonella spp., Leptospira spp. and Coxiella burnetii DNA in immunocompromised hosts through molecular methods

    In-depth investigation of the safety of wooden shelves used for traditional cheese ripening

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    9openInternationalItalian coauthor/editorThe main goal of this research was to characterize the bacterial diversity of the wooden boards used for aging traditional Sicilian cheeses and to evaluate whether pathogenic bacteria are associated with these surfaces. Eighteen cheese dairy factories producing three traditional cheese typologies (PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano) were selected within the region of Sicily. The wooden shelf surfaces were sampled by a destructive method to detach wood splinters as well as by a nondestructive brushing to collect microbial cells. Scanning electron microscopy showed the presence of almost continuous bacterial formations on the majority of the shelves analyzed. Yeasts and fungal hyphae were also visualized, indicating the complexity of the plank communities. The amplicon library of the 16S rRNA gene V3-V4 region was paired-end sequenced using the Illumina MiSeq system, allowing the identification of 14 phyla, 32 classes, 52 orders, 93 families, and 137 genera. Staphylococcus equorum was identified from all wooden surfaces, with a maximum abundance of 64.75%. Among cheese-surface-ripening bacteria, Brevibacterium and Corynebacterium were detected in almost all samples. Several halophilic (Halomonas, Tetragenococcus halophilus, Chromohalobacter, Salimicrobium, Marinococcus, Salegentibacter, Haererehalobacter, Marinobacter, and Idiomarinaceae) and moderately halophilic (Salinicoccus, Psychrobacter, and Salinisphaera) bacteria were frequently identified. Lactic acid bacteria (LAB) were present at low percentages in the genera Leuconostoc, Lactococcus, Lactobacillus, Pediococcus, and Streptococcus. The levels of viable microorganisms on the wooden shelves ranged between 2.4 and 7.8 log CFU/cm2. In some cases, LAB were counted at very high levels (8.2 log CFU/cm2). Members of the Enterobacteriaceae family were detected in a viable state for only six samples. Coagulase-positive staphylococci, Salmonella spp., and Listeria monocytogenes were not detected. Seventy-five strains belonged to the genera Leuconostoc, Lactococcus, Pediococcus, Enterococcus, Lactobacillus, and Weissella.openSettanni, Luca; Busetta, Gabriele; Puccio, Valeria; Licitra, Giuseppe; Franciosi, Elena; Botta, Luigi; Di Gerlando, Rosalia; Todaro, Massimo; Gaglio, RaimondoSettanni, L.; Busetta, G.; Puccio, V.; Licitra, G.; Franciosi, E.; Botta, L.; Di Gerlando, R.; Todaro, M.; Gaglio, R

    Culturomics: bacterial species isolated in 3 healthy donors for faecal microbiota transplantation in Clostridium difficile infection

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    Background. Clostridium difficile infections are the main cause of nosocomial acquired diarrhea, because of prolonged antibiotic regimens. In the last years, mortality has increased due to recurrent infections caused by metronidazole and vancomicin resistant hypervirulent C. difficile strain 027. Faecal Microbiota Transplantation (FMT) is an infusion of faecal material obtained from healthy donors. This procedure reduces mortality in recurrent C. difficile infections (CDI). In this study we identified bacterial species obtained from donors' stool samples using culturomics. Materials and methods. Three donors were selected for FMT in three recipients affected by CDI. Faces obtained for FMT underwent culturomics, applying 17 different culture methods. Results and conclusions. Several different bacteria were isolated from donors. In two donors 4 potentially pathogenic bacteria were isolated; this suggests the use of culturomics for donors' screening or for selection of bacteria to infuse

    Microbial activation of wooden vats used for traditional cheese production and evolution of the neoformed biofilms

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    Three Lactococcus lactis subsp. cremoris strains were used to develop ad hoc biofilms on the surfaces of virgin wooden vats used for cheese production. Two vats (TZ) were tested under controlled conditions (pilot plant), and two vats (TA) were tested under uncontrolled conditions (industrial plant). In each plant, one vat (TA1 and TZ1) was used for the control, traditional production of PDO Vastedda della Valle del Belìce (Vastedda) cheese, and one (TA2 and TZ2) was used for experimental production performed after lactococcal biofilm activation and the daily addition of a natural whey starter culture (NWSC). Microbiological and scanning electron microscopy analyses showed differences in terms of microbial levels and composition of the neoformed biofilms. The levels of the microbial groups investigated during cheese production showed significant differences between the control trials and between the control and experimental trials, but the differences were not particularly marked between the TA2 and TZ2 productions, which showed the largest numbers of mesophilic lactic acid bacterium (LAB) cocci. LAB populations were characterized phenotypically and genotypically, and 44 dominant strains belonging to 10 species were identified. Direct comparison of the polymorphic profiles of the LAB collected during cheese making showed that the addition of the NWSC reduced their biodiversity. Sensory evaluation showed that the microbial activation of the wooden vats with the multistrain Lactococcus culture generated cheeses with sensory attributes comparable to those of commercial cheese. Thus, neoformed biofilms enable a reduction of microbial variability and stabilize the sensorial attributes of Vastedda cheese
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