74 research outputs found

    Tribology of the lubricant quantized-sliding state

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    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple 1D boundary lubricated model [Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized 2D description of a confined multi-layer solid lubricant under shear. This dynamical state, marked by a nontrivial ``quantized'' ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical ``pinned'' state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.Comment: 11 pages, 11 figure

    Tuning friction with composite hierarchical surfaces

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    N.M.P. is supported by the European Research Council PoC 2015 “Silkene” No. 693670, by the European Commission H2020 under the Graphene Flagship Core 1 No. 696656 (WP14 “Polymer Nanocomposites”) and FET Proactive “Neurofibres” grant No. 732344. G.C. and F.B. are supported by H2020 FET Proactive “Neurofibres” grant No. 732344

    14q13 distal microdeletion encompassing NKX2-1 and PAX9: Patient report and refinement of the associated phenotype

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    Chromosome 14q11-q22 deletion syndrome (OMIM 613457) is a rare genomic disorder whose associated phenotype is heterogeneous, depending on the size, and, mostly, on the deleted region. We report the clinical and molecular characterization of a female newborn, whose phenotype was characterized by poor growth, dysmorphic facial features, subclinical hypothyroidism, and mild reduction of CD3CD8 Lymphocytes with increased CD4/CD8 ratio. By array-CGH, we identified a 4.08 de novo interstitial deletion of the 14q13.2q21.1 region, which includes 16 OMIM genes.Our patient phenotype is compared with other published cases, for a better classification of the 14q11-q22 deletion syndrome. We demonstrated that the 14q13.2q21.1 deletion, which encompasses NKX2-1, but not FOXG1 gene and HPE8 region, identifies a well defined, more benign, microdeletion syndrome. This report confirms that an early identification with accurate characterization of the genomic disorders is of great relevance, enabling proper genetic counseling of the reproductive risk, as well as disease prognosis, and patient management. © 2016 Wiley Periodicals, Inc

    In-hospital and web-based intervention to counteract vaccine hesitancy in very preterm infants’ families: a NICU experience

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    Background Vaccine hesitancy is a global problem, carrying significant health risks for extremely vulnerable population as that of preterm infants. Social media are emerging as significant tools for public health promotion. Our aim was to evaluate both the coverage and the timeliness of routine immunizations in a cohort of preterm infants (< 33 weeks of gestational age) at 24 months of age whose families have been subjected to in-hospital and web-based interventions to counteract vaccine hesitancy. Methods For a period of 2 years parents of preterm infants were instructed during their follow up visits by a member of the NICU team to get correct informations about vaccines from a social network page. Vaccination rates of preterm infants were assessed at 24 months of chronological age with an electronic database and compared to both general population and historical cohort. Results Coverage and timeliness of vaccinations at 24 months of age of 170 preterm infants were analyzed in December 2019. Gestational age and birth weight median (IQR) were, respectively, 31.0 (5.0) weeks and 1475.0 (843.8) g. Coverage rates were similar to those of the regional population (p > 0.05), while timeliness of administration was significantly delayed compared to the recommended schedule (p < 0.001). Age of administration was not correlated with either body weight and gestational age at birth (Spearman rank, p > 0.05). DTaP-IPV-HBV-Hib 2nd and 3rd doses, MMR and Varicella vaccines coverage data were higher compared to historical cohort (p < 0.05). Conclusion Increasing vaccine confidence through web-based interventions could have a positive impact on vaccination acceptance of parents of preterm infants, although timeliness results still delayed. There is a strong need to develop different and effective vaccination strategies to protect this very vulnerable population

    Hydrolyzed protein formula for allergy prevention in preterm infants: follow-up analysis of a randomized, triple-blind, placebo-controlled study

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    Background: Allergic diseases are a major public health burden worldwide. Evidence suggests that early nutrition might play a key role in the future development of allergies and the use of hydrolyzed protein formulas have been proposed to prevent allergic disease, mainly in term infants with risk factors. Aim: To evaluate the preventive effect of a hydrolyzed protein formula vs. an intact protein formula on allergy development in preterm infants with or without risk factors. Methods: We performed a 3-year follow-up study of a previous triple-blind, placebo-controlled randomized trial. Evidence of atopic dermatitis, asthma and IgE-mediated food allergies were evaluated according to a validated parental questionnaire (Comprehensive Early Childhood Allergy Questionnaire). Food sensitization was also investigated by skin prick test at 3 years of chronological age. Results: Of the 30 subjects in the intact protein formula group and 30 in the extensively hydrolyzed formula group, respectively 18 and 16 completed the 3-year follow-up and entered the final analysis. No group differences in the incidence of atopic dermatitis, asthma, IgE-mediated food allergies, and food sensitization were found. Conclusion: Despite the small number of cases, extensively hydrolyzed protein formula seems to be ineffective in allergic diseases prevention in preterm neonates. Further adequately powered, randomized controlled trials evaluating hydrolyzed protein formula administration to prevent allergic diseases in preterm neonates are needed

    Diencephalic Syndrome Due to Optic Pathway Gliomas in Pediatric Patients: An Italian Multicenter Study

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    : Diencephalic syndrome (DS) is a rare pediatric condition associated with optic pathway gliomas (OPGs). Since they are slow-growing tumors, their diagnosis might be delayed, with consequences on long-term outcomes. We present a multicenter case series of nine children with DS associated with OPG, with the aim of providing relevant details about mortality and long-term sequelae. We retrospectively identified nine children (6 M) with DS (median age 14 months, range 3-26 months). Four patients had NF1-related OPGs. Children with NF1 were significantly older than sporadic cases (median (range) age in months: 21.2 (14-26) versus 10 (3-17); p = 0.015). Seven tumors were histologically confirmed as low-grade astrocytomas. All patients received upfront chemotherapy and nutritional support. Although no patient died, all of them experienced tumor progression within 5.67 years since diagnosis and were treated with several lines of chemotherapy and/or surgery. Long-term sequelae included visual, pituitary and neurological dysfunction. Despite an excellent overall survival, PFS rates are poor in OPGs with DS. These patients invariably present visual, neurological or endocrine sequelae. Therefore, functional outcomes and quality-of-life measures should be considered in prospective trials involving patients with OPGs, aiming to identify "high-risk" patients and to better individualize treatment

    Minimally Invasive Laser Treatment of Ureterocele

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    Introduction: Ureterocelemay cause severe pyelo-ureteral obstruction with afebrile urinary tract infections in infants and children. Early decompressive treatment is advocated to reduce the risk of related renal and urinary tract damage. Endoscopic techniques of incision have been offered utilizing diathermic electrode. We adopted laser energy to release the obstruction of the ureterocele and reduce the need of further surgery. Our technique is described and results are presented, compared with a group of matched patients treated by diathermic energy.Materials and methods: Decompression was performed by endoscopic multiple punctures at the basis of the ureterocele. Holmium YAG Laser was utilized with 0.5–0.8 joule energy, through 8–9.8F cystoscope under general anesthesia. The control group received ureterocele incision by diathermic energy through pediatric resettoscope. Foley indwelling catheter was removed after 18–24 h. Renal ultrasound was performed at 1, 3, 6, and 12 months follow-up. Voiding cysto-urethrogram and radionuclide renal scan were done at 6–18 months in selected cases. Statistical analysis was utilized for data evaluation.Results: From January 2012 to December 2017, 64 endoscopic procedures were performed: 49 were ectopic and 15 orthotopicureteroceles. Fifty-three were in duplex systems, mostly ectopic. Mean age at endoscopy was 6.3 months (1–168). Immediate decompression of the ureterocele was obtained, but in five cases (8%) a second endoscopic puncture was necessary at 6–18 months follow-up for recurrent dilatation. Urinary tract infections and de novo refluxes occurred in 23.4 and 29.7% in the study group, compared to 38.5 and 61.5% in the 26 controls (p < 0.05). Further surgery was required in 12 patients (18%) at 1–5 years follow-up (10 in ectopic ureteroceles with duplex systems): seven ureteral reimplantation for reflux, five laparoscopic hemy-nephro-ureterectomy. Orthotopic ureteroceceles had better outcome. Secondary surgery was necessary in 13 patients (50.0%) of control group (p < 0.05).Conclusions: Early endoscopic decompression should be considered first line treatment of obstructing ureterocele in infants and children. Multiple punctures at the basis of the ureterocele, performed by low laser energy, is resulted a really minimally invasive treatment, providing immediate decompression of the upper urinary tract, and reducing the risk of further aggressive surgery

    Universal Newborn Screening for Congenital Cytomegalovirus Infection - From Infant to Maternal Infection: A Prospective Multicenter Study

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    Introduction: Most infants at risk for cytomegalovirus (CMV)-associated sensorineural hearing loss (SNHL) are unrecognized because of the absence of a universal neonatal CMV screening. The search of CMV-DNA by molecular methods in salivary swabs was demonstrated to be a reliable approach. This study describes the results obtained by carrying out a universal screening for congenital CMV (cCMV) infection including all live-born newborns in three Italian sites, as well as the therapeutic interventions and clinical outcome of the CMV-infected neonates. Moreover, CMV maternal infection's characteristics were evaluated. Methods: To confirm or exclude cCMV infection, a CMV-DNA-positive result on a first salivary swab was followed by repeated saliva and urine samples collected within 21 days of age. Breast milk samples were also collected. The search of CMV-DNA was performed with a single automated quantitative commercial real-time PCR assay, regardless of the type of samples used. Results: A total of 3,151 newborns were enrolled; 21 (0.66%) of them were congenitally infected (median saliva viral load at screening, 6.65 [range, 5.03-7.17] log10 IU/ml). Very low/low viral load in screening saliva samples (median value, 1.87 [range, 1.14-2.59] log10 IU/ml) was associated with false-positive results (n = 54; 1.7%). CMV-DNA was detected in almost half of the breast milk samples of mother-infant pairs with a false-positive result, suggesting that contamination from breast milk may not be the only explanation in the study population. cCMV infection confirmation with the search of CMV-DNA in a urine sample proved to be the gold standard strategy, since false-positive results were observed in 4/54 (7.5%) of the repeated saliva samples. Symptomatic cCMV infection was observed in 3/21 (14.3%) infants; notably, one (4.7%) developed moderate unilateral SNHL at 5 months after birth. Finally, two symptomatic cCMV infections were associated with primary maternal infection acquired in the first trimester of gestation; one newborn with severe cCMV symptoms was born to a mother with no CMV checkups in pregnancy. Conclusion: Without universal neonatal CMV screening, some infected infants who develop late neurological sequelae may not be recognized and, consequently, they are not able to benefit early from instrumental and therapeutic interventions to limit and/or treat CMV disease
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