41 research outputs found

    Fabrication and characterization of a novel photoactive based (0-3) piezocomposite material with potential as a functional material for additive manufacturing of piezoelectric sensors

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    The development of 3D-printed sensors and actuators from piezocomposite materials has increased in recent years due to the ease of production, low-cost and improved functionality additive manufacturing provides. The piezocomposite material developed in this work has the potential to be used as a functional material in stereolithographic additive manufacturing by combining the optical, viscoelastic properties of NOA 65 and the piezoelectric properties of Barium Titanate. The new (0-3) piezocomposite material consists of Norland Optical Adhesive 65 (NOA 65) as the polymer matrix and Barium Titanate (BaTiO3) with particles sizes (100 nm, 200 nm and 500 nm) as the dielectric filler. We synthesized thin film samples of the (0-3) piezocomposite with 60% w/w BaTiO3 using solution mixing and spin coating method to produce samples with layer thickness of 100 ÎŒm. Fourier-transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) techniques were used to analyze the microstructure of the piezocomposite to determine the effect of different particles sizes of BaTiO3 on the structural and mechanical properties of the composite. The longitudinal piezoelectric coefficient d33 was also measured using the laser vibrometer technique. Both single point scans and full surface scans were carried out to obtain the average piezoelectric coefficient d33 of the composite material. The results of the SEM confirmed the (0-3) structure of the piezocomposite material with isolated BaTiO3 nanoparticles. It further showed the uniform distribution of the BaTiO3 nanoparticles across each of the samples. FTIR analysis showed that the filler nanoparticles had no effect on the native structure of the polymer matrix. The longitudinal piezoelectric coefficient d33 of the piezocomposite material was observed to increase with increasing BaTiO3 particle sizes, while the indentation modulus of the composite investigated using the method of Oliver and Pharr was observed to decrease with an increase in particle size. Results from the single point scans showed the composite with BaTiO3 particle size 100 nm, 200 nm and 500 nm having an average d33 of 2.1 pm/V, 3.0 pm/V and 3.9 pm/V while the average d33 obtained from the full surface scan of 1430 scan points showed 1.4 pm/V, 6.1 pm/V, 7.2 pm/V

    Characterization of (0-3) piezocomposite materials for transducer applications

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    In this study, we have developed and characterized two different (0-3) piezoelectric composite materials with potential to be used in sensing applications. The composite materials were made using Polydimethylsiloxane (PDMS) as the polymer matrix with Barium Titanate (BaTiO3), and Lead Zirconate Titanate (PZT51) as the dielectric fillers. Thin film samples of the (0-3) piezocomposites were prepared using a solution mixing and spin coating method to produce composites with (0-3) connectivity pattern and layer thickness of mathbf{100} mumathbf{m}, The microstructure of the piezocomposites were analyzed using a scanning electron microscope to determine the connectivity structure and homogeneity of the piezocomposites. The mechanical properties of the composites were determined using the method of Oliver and Pharr. FTIR analysis was used to determine the effects of the fillers on the structure of the piezocomposite. The average piezoelectric pmb{d}{mathit{33}} coefficient of the piezocomposites were also measured using the laser vibrometer technique and determined to be 30 pm/V for the piezocomposite consisting of Barium Titanate (BaTiO3) and 32 pm/V for the piezocomposite consisting of Lead Zirconate Titanate (PZT51)

    Protein carbonyl group content in patients affected by familiar chronic nail candidiasis.

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    Familiar chronic nail candidiasis (FCNC) is a rare disorder characterized by early-onset infections caused by different species of Candida, restricted to the nail of the hands and feet, and associated with a low serum concentration of intercellular adhesion molecule 1. Host defense mechanisms against candidiasis require the cooperation of many immune cells through several candidacidal mechanisms, including oxygen-dependent killing mechanisms, mediated by a superoxide anion radical myeloperoxidase--H2O2--halide system, and reactive nitrogen intermediates. We analyzed protein carbonyl groups (considered a useful marker of oxidative stress) in the serum of patients belonging to a five-generation Italian family with an isolated form of FCNC. Serum protein carbonyl groups in FCNC patients were significantly lower than those measured in healthy donors. Also, if this hypothesis is merely speculative, we could suggest that the decreased circulating level of protein carbonyl groups in these patients is not a marker of a lower oxidative stress condition, but might be linked to a lower protease activity

    Pontine tegmental cap dysplasia: developmental and cognitive outcome in three adolescent patients

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    Pontine Tegmental Cap Dysplasia (PTCD) is a recently described, rare disorder characterized by a peculiar cerebellar and brainstem malformation. Nineteen patients have been reported to date, of which only one in the adolescent age, and data on the clinical, cognitive and behavioural outcome of this syndrome are scarce

    MKS3/TMEM67 mutations are a major cause of COACH syndrome, a joubert syndrome related disorder with liver involvement

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    The acronym COACH defines an autosomal recessive condition of Cerebellar vermis hypo/ aplasia, Oligophrenia, congenital Ataxia, Coloboma and Hepatic fibrosis. Patients present the “molar tooth sign”, a midbrain-hindbrain malformation pathognomonic for Joubert Syndrome (JS) and Related Disorders (JSRDs). The main feature of COACH is congenital hepatic fibrosis (CHF), resulting from malformation of the embryonic ductal plate. CHF is invariably found also in Meckel syndrome (MS), a lethal ciliopathy already found to be allelic with JSRDs at the CEP290 and RPGRIP1L genes. Recently, mutations in the MKS3 gene (approved symbol TMEM67), causative of about 7% MS cases, have been detected in few Meckel-like and pure JS patients. Analysis of MKS3 in 14 COACH families identified mutations in 8 (57%). Features such as colobomas and nephronophthisis were found only in a subset of mutated cases. These data confirm COACH as a distinct JSRD subgroup with core features of JS plus CHF, which major gene is MKS3, and further strengthen gene-phenotype correlates in JSRDs

    Incidenza delle allergopatie nella popolazione pediatrica della nostra provincia

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    Con questo lavoro vogliamo riferire la nostra esperienza di ambulatorio di Broncopneumologia pediatrica, attraverso un’analisi retrospettiva essenzialmente dei dati dei Prick Test, da noi eseguiti, per avere un orientamento piĂč preciso dell’incidenza dei singoli allergeni nella popolazione pediatrica della nostra provincia. Abbiamo valutato n° 220 prick test, di pazienti di etĂ  compresa tra 4 mesi e 18 anni, da noi eseguiti negli ultimi due anni. Sono risultati positivi, per almeno un allergene, n° 113 (51.4%), mentre sono risultati negativi n° 107 (48.6%). L’utenza delle nostre strutture, bambini della cittĂ  e provincia, si verifica nella maggior parte dei casi per allergia agli acari della polvere, che spesso determinano una monosensibilizzazione, seguiti in ordine di incidenza da Parietaria, Olivo e graminacee. Si vuole inoltre sottolineare: — l’allergene della Parietaria si comporta nel nostro territorio come allergene perenne; — l’importanza dell’allergia all’Olivo, che nelle nostre zone, pur presentando lo stesso andamento stagionale, ha una maggiore incidenza rispetto alle regioni settentrionali. — l’allergia alimentare nella nostra esperienza mostra un’incidenza non elevata

    Su un caso di asma emozionale

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    Gli autori hanno ritenuto interessante la pubblicazione di questo caso per sottolineare la complessità della dinamica etiopatogenetica dell’asma, che va riferita non solo a stimoli allergici ma spesso a tanti altri fattori che non implicano un meccanismo IgE-mediato

    Alcune valutazioni etiopatogenetiche della sindrome orticaria angioedema

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    UAS is provoked only in a few cases by IgE-mediated mecchanism (28,5% on our patients). Most of ou children (71,5%) with UAS show skin tests and RAST negative to all inhalant or alimentary antigens. Clinical history eliminations diets and challenges are until now the best diagnostic approach

    Osteogenesis Imperfecta/Ehlers\u2013Danlos Overlap Syndrome and Neuroblastoma\u2014Case Report and Review of Literature

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    Osteogenesis imperfecta/Ehlers\u2013Danlos (OI/EDS) overlap syndrome is a recently described disorder of connective tissue, characterized by mutation of COL1A1 (17q21.33) or COL1A2 (7q21.3) genes, that are involved in \u3b1-1 and \u3b1-2 chains of type 1 collagen synthesis. The clinical spectrum of this new clinical entity is broad: patients could present a mixed phenotype that includes features of both osteogenesis imperfecta (bone fragility, long bone fractures, blue sclerae, short stature) and Ehlers\u2013Danlos syndrome (joint hyperextensibility, soft and hyperextensible skin, abnormal wound healing, easy bruising, vascular fragility). We reported the case of a young Caucasian girl with severe short stature and a previous history of neuroblastoma, who displayed the compound phenotype of OI/EDS. Next generation sequencing was applied to the proband and her parent genome. Our patient presented a de novo heterozygous COL1A1 variant (c.3235G>A, p.Gly1079Ser), whose presence might be indicative of diagnosis of OI/EDS overlap syndrome. We also hypothesize that the association with the previous history of neuroblastoma could be influenced by the presence of COL1A1 mutation, whose role has been already described in the behavior and progression of some cancers

    Wide spectrum of congenital anomalies including choanal atresia, malformed extremities, and brain and spinal malformations in a girl with a de novo 5.6-Mb deletion of 13q12.11-13q12.13

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    A 2 1/2-year-old girl with multiple congenital anomalies and a de novo 5.6-Mb deletion on chromosome 13q12.11-13q12.13 is reported. She showed choanal atresia, scalp aplasia cutis, mild dysmorphic features, severe malformation of the hands and feet, Sylvian aqueductal stenosis, hydrocephalus, small cerebellum with pointed cerebellar tonsils, cervical, lumbar and sacral clefting, single central incisor and mild developmental delay. The girl's anomalies were compared with: (A) one boy reported by each of Der Kaloustian et al. [2011] and Tanteles et al. [2011] with similar, albeit smaller, 2.1 to 2.9Mb deletions in which the abnormalities consisted of mild facial dysmorphism, mild malformations of the fingers and/or toes, and developmental delay; (B) one girl reported by Friedman et al. [2006] with similar, albeit larger, 5.7Mb deletion with mild developmental delay and haematological abnormalities; (C) one girl reported by Slee et al. [1991] with a deletion of band q12.2 in chromosome 13, who had Moebius syndrome with facial dysmorphism, high arched palate, micrognathia, and small tongue with no abnormalities of the extremities; and (D) seven additional individuals recorded in the DECIPHER 6.0 database who all had dysmorphic features and developmental delay plus a spectrum of clinical manifestations including deafness, ataxia/oculomotor apraxia, spasticity, small testes, and mild fingers' anomalies. The deleted region hereby reported encompassed 34 known genes, including GJA3, GJB2, and GJB6, which are responsible for autosomal recessive deafness, FGF9, which plays crucial roles in embryonic neurological development, and ATP8A2, which causes a cerebellar ataxia and disequilibrium syndrome. \ua9 2014 Wiley Periodicals, Inc
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