1,163 research outputs found
Geometrical, conformational and topological restraints in regular nucleosome compaction in chromatin
No full textThe folding of the nucleosome array into a chromatin fiber modulates DNA accessibility and is therefore an important factor for the control of gene expression. The statistical analysis of the nucleosome repeat length in chromatin fibers reveals the presence of a ten-fold periodicity suggesting the existence of orientational constraints of the nucleosome units that provide the geometrical conditions of helical conformations. Recently, the elucidation of the x-ray crystal structure of a nucleosome tetramer array and the interpretation of electron microscopy images of reconstituted nucleosome arrays suggested two different architectures of the chromatin fiber. We approached the problem by integrating the experimental findings with geometrical, conformational and topological restraints, under the hypothesis of the minimum distortion of the nucleosome and linker DNA structures. We show that the excluded volume at linker crossing and the torsional energy limit the possible close packing of the nucleosomes in the chromatin fiber. In particular, the torsional energy of the chromatin fiber appears crucial in determining the kind of nucleosome packing for short nucleosome repeat lengths as in telomeres and yeast chromatin. (C) 2010 Elsevier B.V. All rights reserved
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
A sonographic classification of adenomyosis: interobserver reproducibility in the evaluation of type and degree of the myometrial involvement
No full textObjective: To study the interobserver reproducibility of our new ultrasonographic mapping system to define the type and extension of uterine adenomyosis. Design: Interobserver study involving two observers with different medical backgrounds and gynecological ultrasound experience. Setting: University hospital. Patients: Seventy consecutive women who underwent transvaginal ultrasound for suspected endometriosis, pelvic pain, heavy menstrual bleeding, and infertility. Intervention: Two operators (observers A and B), who were blinded, independently reviewed the ultrasound videos offline, assessing the type of adenomyosis and the severity of the disease. Diagnosis of adenomyosis was made when typical ultrasonographic features of the disease were observed at the examination. Adenomyosis was defined as diffuse, focal, and adenomyoma according to the ultrasonographic characteristics. The severity of adenomyosis was described using a new schematic scoring system that describes the extension of the disease considering all possible ultrasound adenomyosis features. Main Outcome Measures: Reproducibility of the new mapping system for adenomyosis and rate agreement between two operators. Results: Multiple rate agreements to classify the different features and the score of adenomyosis (diffuse, focal adenomyoma, and focal or diffuse alteration of junctional zone) ranged from substantial to almost perfect (Cohen κ = 0.658 – 1) except for adenomyoma score 4 (one or more adenomyomas with the largest diameter >40 mm) in which interobserver agreement was moderate (κ = 0.479). Conclusion: Our new scoring system for uterine adenomyosis is reproducible and could be useful in clinical practice. The standardization of the transvaginal approach and of the sonographer training represent a crucial point for a correct diagnosis of myometrial disease
Ellagic acid and Annona muricata in the chemoprevention of HPV-related pre-neoplastic lesions of the cervix
No full textEllagic acid is a phenolic compound naturally present in nuts and berries. Several studies have demonstrated that this bioactive compound has antioxidant, chemopreventive and antiviral activity. Annona muricata is a type of fruit tree with a long history of traditional use. A number of properties have been attributed to different parts of the plant, including anticancer and antioxidant activities. In the current study, a complex based on ellagic acid, Annona Muricata and antioxidant factors (an ellagic acid complex) was administered to a group of human papilloma virus (HPV) infected women with and without cervical lesions, for 12 months. Its effect on HPV clearance and cervical cytological outcomes was assessed and a group of women with the same clinical features who did not receive the ellagic acid complex served as a control. A positive correlation was observed between intake of ellagic acid complex and negative Pap test following 6 and 12 months of treatment (Ï2 test: 0.041 and 0.014, respectively). Women treated with the ellagic acid complex were less likely to be diagnosed with an abnormal Pap smear at 6 months [Odds ratio (OR): 0.39; 95% confidence interval (CI) 0.14-1.06] and 12 months (OR: 0.35; 95% CI 0.13-0.89), compared with the control group. After adjusting for confounding factors including age and smoking habit, this association remained significant. No effect was observed on HPV clearance or viral integration. The data from the current study suggest a protective effect of the ellagic acid complex on cervical cells, possibly through apoptosis, cell cycle arrest and repair mechanisms
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
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Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID
INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy
*
Author to whom correspondence should be addressed.
Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602
Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023
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Abstract
SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings
Correction to: Safety and Psychological Outcomes of Tandem t:Slim X2 Insulin Pump with Control-IQ Technology in Children, Adolescents, and Young Adults with Type 1 Diabetes: A Systematic Review
No full textThe second author name was incorrectly published as Giula Maria Smylie. The correct name is Giulia Marie Smylie. The original article has been corrected
Scrivere senza anestesia. La chiarezza di Giulia Niccolai
No full textIl saggio colloca storicamente la narratrice e poetessa Giulia Niccolai nel canone del Novecento letterario italiano discutendone poetica e cifre stilistiche. L'ampia analisi proposta tocca tutte le opere dell'autrice evidenziandone i legami intertestuali, anche tra poesia e narrativa, e i progressivi sviluppi in un arco cronologico esteso, tra anni Sessanta e primi anni Duemila. Lo studio coglie anche l'importanza dei riferimenti alle arti visive, in particolare alla fotografia, che Giulia Niccolai ha praticato in prima persona negli anni della Neoavanguardia, e alla pittura americana.The essay places the narrator and poet Giulia Niccolai in the canonical twentieth century Italian literary discussing her poetics and stylistic figures. The wide analysis proposed touches all the works of the author highlighting the intertextual links, also between poetry and narrative, and the progressive developments in an extended chronological period, between the Sixties and early Twenties. The study also captures the importance of references to the visual arts, especially photography, which Giulia Niccolai has practiced in the years of the Neo-avant-garde, and to American painting
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