62 research outputs found

    Robust and Biocompatible Functionalization of ZnS Nanoparticles by Catechol-Bearing Poly(2-Methyl-2-Oxazoline)s.

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    Zinc sulfide (ZnS) nanoparticles (NPs) are particularly interesting materials for their electronic and luminescent properties. Unfortunately, their robust and stable functionalization and stabilization, especially in aqueous media, has represented a challenging and not yet completely accomplished task. In this work, we report the synthesis of colloidally stable, photoluminescent and biocompatible core\u2013polymer shell ZnS and ZnS:Tb NPs by employing a water-in-oil miniemulsion (ME) process combined with surface functionalization via catechol-bearing poly-2-methyl-2-oxazoline (PMOXA) of various molar masses. The strong binding of catechol anchors to the metal cations of the ZnS surface, coupled with the high stability of PMOXA against chemical degradation, enable the formation of suspensions presenting excellent colloidal stability. This feature, combined with the assessed photoluminescence and biocompatibility, make these hybrid NPs suitable for optical bioimaging

    Fine-needle aspiration cytology in children with superficial lymphadenopathy.

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    Introduction: In pediatric population Fine-Needle Aspiration Citology (FNAC) is slowly gaining acceptance in clinical management of Superficial Lymphadenopathy (SL). Our experience adds some data about the usefulness of this technique in diagnosing the cause of a SL and therefore guiding further treatment. Patients and Methods: 238 FNAC were performed in 217 patients with SL, observed at our Institution from 2002 to 2006. The neck was the most frequent localization. The results were available within few hours. In cases of granulomatous findings, the samples were processed for microbiological and PCR test, in order to identify Mycobacteria. Results: 174 were reactive lesions, 38 granulomatous lymphadenopathies, 24 malignant lesions, 2 specimens inadequate for diagnosis. Among the 174 reactive SL, 22 required an incisional biopsy after 1 month follow-up. Among the granulomatous lymphadenopathies, 13 children with Cat-Scratch Disease recovered, 25 with Mycobacteria infection underwent surgical excision. For 24 malignant lesions, the diagnosis was confirmed by further biopsy. Two false negative and no false positive were detected (sensitivity 92%, specificity 100%). No complications were encountered. Conclusions: In our experience FNAC, performed by experienced cytopathologist, has revealed to be a fast, safe, non invasive and inexpensive method to achieve diagnosis in persistent SL. The use of FNAC gave us the possibility to select patients for further investigation and/or surgical treatment. Incisional biopsy remains necessary to confirm the diagnosis in case of malignancy or doubtful lesions

    Percutaneous Trans-Thoracic Procedures in Children With Tumors of Thoracic Wall, Mediastinum and Lung. The Experience of a Single Institution

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    Background While percutaneous trans-thoracic procedures (PTTP) are commonly performed in adults with tumors of thoracic wall, mediastinum and lung, the experience is limited in children, in whom however less invasive methods should be the choice for the diagnosis or the identification of small pulmonary nodules that need to be removed, sparing lung tissue. The results of the PTTP performed by the interventional radiologists in our Pediatric Surgery Department are analyzed. Methods CT-guided biopsies, utilizing a 64-slice CTscanner, with low-radiation dose, were performed applying the coaxial technique with 16-18G needles with a single tissue path. For localization of lung nodules before surgery, two 20G-hook wires were positioned beyond the nodule. CT images after each manipulation of the needles were obtained. US-guided biopsies were performed either with or without coaxial technique through a needle bracket. Younger patients required sedation. All patients underwent a chest radiogram two hours after the procedure and remained under observation for 24 hours. Results From January 2015 to March 2019, 23 procedures were performed in 22 patients (Age:16M- 19Y): 6 patients underwent CT-guided biopsy (4 lung nodules, 2 mediastinal mass); 3 underwent 4 CT-guided hook-wire localization of pulmonary nodules, just before surgery; 13 underwent US-guided biopsy (posterior mediastinum 2; anterior mediastinum 5, thoracic/intrathoracic mass 5). Adequate core biopsies were obtained in all patients, except three, who underwent thoracoscopy/thoracotomy. The hook-wires were successfully positioned in all cases, as confirmed by histology. After the procedure, two patients presented perilesional hemorrhage and one pneumothorax, but they did not required treatment. Conclusion PTTP were successful in most patients, without significant complications. These techniques should be encouraged to avoid diagnostic aggressive surgical approaches in children with cancer. For all cases a multidisciplinary team is essential to discuss the indications and planning the procedures

    Bacillus Calmette-Guérin-related cold thigh abscess as an unusual cause of thigh swelling in infants following BCG vaccine administration: a case series

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    <p>Abstract</p> <p>Introduction</p> <p>Thigh swelling in an infant can be a symptom of a simple benign condition or a life-threatening condition. We observed a cluster of thigh swelling episodes in infants in which the cause was Bacillus Calmette-Guérin-related cold thigh abscess. We report this unusual case series to raise awareness about this diagnosis.</p> <p>Case presentations</p> <p>We performed a retrospective review of five infants (four boys and one girl) who presented with Bacillus Calmette-Guérin-related left thigh abscess. The swelling was noticed by the parents at a mean period of three months prior to presentation. The ages at presentation were five, five, eight and nine months for the boys, and six months for the girl. All of the patients were healthy Saudi infants, and received the Bacillus Calmette-Guérin vaccine at birth. Clinically, all of the patients were well and did not demonstrate signs of systemic infection. All patients underwent needle aspiration, with subsequent incision and drainage in four of the five cases. The cultures obtained from the abscess fluids were the key to establishing the diagnosis. Only three patients (60%) received antituberculosis drugs. Wound healing lasted for a mean period of approximately seven months. Two-year follow-up was unremarkable for all of our patients.</p> <p>Conclusions</p> <p>Technical errors continue to be significant in the development of vaccine-related complications. Bacillus Calmette-Guérin-related cold thigh abscess is an extremely rare entity.</p

    Analysis of miRNA and mRNA Expression Profiles Highlights Alterations in Ionizing Radiation Response of Human Lymphocytes under Modeled Microgravity

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    BACKGROUND: Ionizing radiation (IR) can be extremely harmful for human cells since an improper DNA-damage response (DDR) to IR can contribute to carcinogenesis initiation. Perturbations in DDR pathway can originate from alteration in the functionality of the microRNA-mediated gene regulation, being microRNAs (miRNAs) small noncoding RNA that act as post-transcriptional regulators of gene expression. In this study we gained insight into the role of miRNAs in the regulation of DDR to IR under microgravity, a condition of weightlessness experienced by astronauts during space missions, which could have a synergistic action on cells, increasing the risk of radiation exposure. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed miRNA expression profile of human peripheral blood lymphocytes (PBL) incubated for 4 and 24 h in normal gravity (1 g) and in modeled microgravity (MMG) during the repair time after irradiation with 0.2 and 2Gy of \u3b3-rays. Our results show that MMG alters miRNA expression signature of irradiated PBL by decreasing the number of radio-responsive miRNAs. Moreover, let-7i*, miR-7, miR-7-1*, miR-27a, miR-144, miR-200a, miR-598, miR-650 are deregulated by the combined action of radiation and MMG. Integrated analyses of miRNA and mRNA expression profiles, carried out on PBL of the same donors, identified significant miRNA-mRNA anti-correlations of DDR pathway. Gene Ontology analysis reports that the biological category of "Response to DNA damage" is enriched when PBL are incubated in 1 g but not in MMG. Moreover, some anti-correlated genes of p53-pathway show a different expression level between 1 g and MMG. Functional validation assays using luciferase reporter constructs confirmed miRNA-mRNA interactions derived from target prediction analyses. CONCLUSIONS/SIGNIFICANCE: On the whole, by integrating the transcriptome and microRNome, we provide evidence that modeled microgravity can affects the DNA-damage response to IR in human PBL

    Towards improved cover glasses for photovoltaic devices

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    For the solar energy industry to increase its competitiveness there is a global drive to lower the cost of solar generated electricity. Photovoltaic (PV) module assembly is material-demanding and the cover glass constitutes a significant proportion of the cost. Currently, 3 mm thick glass is the predominant cover material for PV modules, accounting for 10-25% of the total cost. Here we review the state-of-the-art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide: (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re-emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies; (iii) Successful laboratory-scale demonstration of proof-of-concept, with increases of 1-6% in Isc and 1-8% Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints

    3D-Printed Architected Materials Inspired by Cubic Bravais Lattices

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    Learning from Nature and leveraging 3D printing, mechanical testing, and numerical modeling, this study aims to provide a deeper understanding of the structure-property relationship of crystal-lattice-inspired materials, starting from the study of single unit cells inspired by the cubic Bravais crystal lattices. In particular, here we study the simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) lattices. Mechanical testing of 3D-printed structures is used to investigate the influence of different printing parameters. Numerical models, validated based on experimental testing carried out on single unit cells and embedding manufacturing-induced defects, are used to derive the scaling laws for each studied topology, thus providing guidelines for materials selection and design, and the basis for future homogenization and optimization studies. We observe no clear effect of the layer thickness on the mechanical properties of both bulk material and lattice structures. Instead, the printing direction effect, negligible in solid samples, becomes relevant in lattice structures, yielding different stiffnesses of struts and nodes. This phenomenon is accounted for in the proposed simulation framework. The numerical models of large arrays, used to define the scaling laws, suggest that the chosen topologies have a mainly stretching-dominated behavior- A hallmark of structurally efficient structures-where the modulus scales linearly with the relative density. By looking ahead, mimicking the characteristic microscale structure of crystalline materials will allow replicating the typical behavior of crystals at a larger scale, combining the hardening traits of metallurgy with the characteristic behavior of polymers and the advantage of lightweight architected structures, leading to novel materials with multiple functions

    ENDOABDOMINAL FOREIGN BODY IN AN INFANT: A CASE REPORT

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    A 40 days old newborn male was brought to the Emergency Paediatric Department by his parents at 8:00 a.m. suffering from abdominal distension, acute constipation and persistently crying. He is the first born of the couple, breast-fed and otherwise healthy. Up till the previous afternoon, the baby was perfectly normal and had evacuated regularly after the mid-day meal. In the hours that followed, he complained of lack of appetite, vomiting, fever and had recurrent crisis of crying that, during the night, became interminable. On medical examination the child appeared in general good health, but looked to be suffering greatly. The abdomen was tense and painful. Abdominal examination showed a hard and movable mass at lower quadrants. Ultrasound study and X-ray investigation confirmed the presence of a mass localised at sigma level and digital examination revealed an empty rectum and a mass could be palpated, with difficulty, as a high \u201cfaecaloma\u201d. The anus was gaping and bleeding. A first therapeutical approach was an attempt to remove the \u201cfaecal impaction\u201d with rectal washing for some days. This treatment proved to be unsuccessful. On the fifth day we decided to remove the faecal mass by sedation in operating room. By the rectal approach some pieces of the mass were removed and they were discovered to be fragments of a vegetable. A laparatomy proved necessary to remove a big carrot (13 cm length and 3 cm width) within the sigma, split into two fragments. The parents, informed immediately, expressed surprise and incredulity and confirmed that only they and some close relatives look care of the baby at all times. The impossibility to attribute the finding of this inner foreign body to an accidental event left us no choice, but to report the case immediately to a magistrate

    Il chilotorace congenito e acquisito. Congenital and acquired chylothorax

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    BACKGROUND/PURPOSE: Chylothorax in paediatric age is a life-threatening clinical entity that cause serious respiratory, nutritional and immunologic complications. Chylothorax in the absence of trauma or tumour is uncommon and lymphangiomatosis of the bone, although extremely rare, has been associated with these condition. The authors describe the case of a two-year-old girl who presented with a massive chylothorax associated with hip and paravertebral lymphangioma and spread lymphangiomatosis of the spine. The authors also review the literature and their experience of congenital and postoperative chylothorax in order to establish guidelines for the diagnosis and management of both primary and postoperative chylothorax in paediatric age. METHODS: From 1990 and 1999, 14 children had chylothorax. 9 patients had pleural effusion after surgical procedure, 5 patients had congenital chylothorax (both in prenatal and neonatal time), one of whom with bone lymphangiomatosis associated. RESULTS: Postoperative chylothorax has been successfully treated by conservative approach (starvation, total parenteral nutrition and chest tube) in 6 out of 7 cases (two patients died because of complex cardiac malformation). Conservative approach is useful in case of congenital chylothorax, but not with bone lymphangiomatosis associated. CONCLUSIONS: Postoperative and congenital chylothorax is well managed with conservative treatment. Chylothorax with bone lymphangiomatosis associated needs early and aggressive surgical approach

    Laparotomic versus laparoscopic Duhamel pull-through for hirschsprung disease in infants and children

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    PURPOSE: The aim of this study was to analyze the results from laparotomic and laparoscopic Duhamel pull-through in the treatment of Hirschsprung disease. MATERIALS AND METHODS: In our department, the Duhamel pull-through technique was adopted in most patients and the laparoscopic technique used since 1999 follows the original Duhamel procedure. Patients were identified retrospectively and followed up in our outpatient clinic. Preoperative, operative, and postoperative data were collected and analyzed. RESULTS: Between January 1992 and March 1999, 21 children with Hirschsprung disease underwent primary surgical correction using the classic open Duhamel pull-through. The mean age at operation was 14 months, the median operating time was 297 minutes, and the average postoperative stay was 10 days. From April 1999 to December 2003, 22 children underwent laparoscopic Duhamel pull-through. The mean age at operation was 14.6 months, the mean operative time was 253 minutes, and the mean postoperative stay was 6.8 days. The rates of early (4.7% vs. 4.7%) and late (19% vs. 23.8%) complications were similar in the two groups, but in the laparoscopic group the mean operative time and postoperative hospital stay were lower. CONCLUSION: With these encouraging results, laparoscopic Duhamel pull-through has become our procedure of choice in the surgical management of Hirschsprung's disease
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