224 research outputs found
A comparison between families obtained from different proper elements
Using the hierarchical method of family identification developed by Zappala et al., the results coming from the data set of proper elements computed by Williams (about 2100 numbered + about 1200 PLS 2 asteroids) and by Milani and Knezevic (5.7 version, about 4200 asteroids) are compared. Apart from some expected discrepancies due to the different data sets and/or low accuracy of proper elements computed in peculiar dynamical zones, a good agreement was found in several cases. It follows that these high reliability families represent a sample which can be considered independent on the methods used for their proper elements computation. Therefore, they should be considered as the best candidates for detailed physical studies
From asteroid clusters to families: A proposal for a new nomenclature
Some confusion on the number, reliability, and characteristics of asteroid families is the result of using the single word 'family' for naming asteroid groupings identified in very different ways. Here we propose a new terminology which in our opinion would alleviate this problem
Early Effects of P-15 on Human Bone Marrow Stem Cells
OBJECTIVES: Peptide-15 (P-15) is an analogue of the cell binding domain of collagen. P-15 has been shown to facilitate physiological to process in a way similar to collagen, to serve as anchorage for cells, and to promote the binding, migration and differentiation of cells. However, how P-15 alters osteoblast activity to promote bone formation is poorly understood. To study the osteoinductive properties of peptide P-15, we analyzed the expression levels of bone related genes in human mesenchymal stem cells treated with this biomaterial. MATERIAL AND METHODS: Using real time Reverse Transcription-Polymerase Chain Reaction the quantitative expression of specific genes, like transcriptional factors (RUNX2 and SP7), bone related genes (SPP1, COL1A1, COL3A1, BGLAP, ALPL, and FOSL1) and mesenchymal stem cells marker (ENG) were examined. RESULTS: P-15 causes a considerable induction of osteoblast transcriptional factor like osterix (SP7) and of the bone related genes osteopontin (SPP1) and osteocalcin (BGLAP). In contrast the expression of endoglin (ENG) was markedly decreased in stem cells treated with P-15 respect to untreated cells, indicating the differentiation effect of this biomaterial on stem cells. CONCLUSIONS: The present study shows the effect of P-15 on mesenchymal stem cells in the early differentiation stages: P-15 is an inducer of osteogenesis on human stem cells as indicated by the activation of bone related markers SP7, SPP1 and BGLAP.The results may allow a better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects
Genetic Effects of Trabecular Titanium on MG-63 Cell Line: A Genetic Profiling Evaluation
Pure titanium and titanium alloys are materials widely used in orthopaedics because of their mechanical properties, chemical stability, and biocompatibility. Recently, a new highly porous titanium biomaterial named Trabecular Titanium (TT) has been developed. In this in vitro study, we tested the genetic effects of TT on osteoblast-like cells (MG63) using DNA microarrays technology: cDNA microarrays provides the ability to comparatively analyze mRNA expression of thousands of genes in parallel thus showing activated and repressed genes by the presence of the TT.
Several genes that were significantly up- or downregulated have been identified. Globally, it was demonstrated that TT stimulates osteoblasts proliferation and differentiation, and reduces apoptosis. Therefore, all these effects can contribute to improve the osseointegration of this material. These results encourage the clinical application of Trabecular Titanium to prosthetic devices
Virtual colonoscopy in stenosing colorectal cancer
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
CAROTID INTIMAL-MEDIA THICKNESS AND ENDOTHELIAL FUNCTION IN YOUNG PATIENTS WITH HISTORY OF MYOCARDIAL INFARCTION.
AIM:
The aim of the study was to evaluate the prevalence of carotid atherosclerosis and endothelial dysfunction in 45 young patients (38 mens and 7 females) with myocardial infarction (MI), age 29-45, mean age 42+/-3 years, to verify its possible role as a marker of coronary atherosclerosis.
METHODS:
Vascular echography was performed to verify the presence of carotid atherosclerosis and/or endothelial dysfunction in 45 young patients with MI and in 45 healthy control subjects well matched for age and sex.
RESULTS:
We observed a normal intima media thickness (IMT) only in 30% of patients with juvenile myocardial infarction (JMI) compared with 66% in the control group (P<0.0001) and 34% of patients showed an increased IMT compared with 24% of healthy subjects (P<0.0001). Compared with control subjects, patients with JMI had lower flow-mediated reactivity of the brachial arteries (P<0.05). There was a negative linear relationship between flow-mediated dilation and IMT (P<0.001). The severity of coronary artery disease (CAD) was correlated with increased IMT and with a lower flow-mediated dilation. Finally, multiple regression analysis, demonstrated that both brachial-artery reactivity and carotid IMT were significantly and independently correlated with severity of CAD.
CONCLUSIONS:
Structural (carotid atherosclerosis) and functional changes (endothelial dysfunction) were present at an early age in the arteries of persons with history of JMI
A severe case of hemobilia and biliary fistula following an open urgent cholecystectomy
<p>Abstract</p> <p>Background</p> <p>Cholecystectomy has been the treatment of choice for symptomatic gallstones, but remains the greatest source of post-operative biliary injuries. Laparoscopic approach has been recently preferred because of short hospitalisation and low morbidity but has an higher incidence of biliary leakages and bile duct injuries than open one due to a technical error or misinterpretation of the anatomy. Even open cholecystectomy presents a small number of complications especially if it was performed in urgency. Hemobilia is one of the most common cause of upper gastrointestinal bleeding from the biliary ducts into the gastrointestinal tract due to trauma, advent of invasive procedures such as percutaneous liver biopsy, transhepatic cholangiography, and biliary drainage.</p> <p>Methods</p> <p>We report here a case of massive hemobilia in a 60-year-old man who underwent an urgent open cholecystectomy and a subsequent placement of a transhepatic biliary drainage.</p> <p>Conclusion</p> <p>The management of these complications enclose endoscopic, percutaneous and surgical therapies. After a diagnosis of biliary fistula, it's most important to assess the adequacy of bile drainage to determine a controlled fistula and to avoid bile collection and peritonitis. Transarterial embolization is the first line of intervention to stop hemobilia while surgical intervention should be considered if embolization fails or is contraindicated.</p
Evidence for the formation of comet 67P/Churyumov-Gerasimenko through gravitational collapse of a bound clump of pebbles
The processes that led to the formation of the planetary bodies in the Solar System are still not fully understood. Using the results obtained with the comprehensive suite of instruments on-board ESA’s Rosetta mission, we present evidence that comet 67P/Churyumov-Gerasimenko likely formed through the gentle gravitational collapse of a bound clump of mm-sized dust aggregates (“pebbles”), intermixed with microscopic ice particles. This formation scenario leads to a cometary make-up that is simultaneously compatible with the global porosity, homogeneity, tensile strength, thermal inertia, vertical temperature profiles, sizes and porosities of emitted dust, and the steep increase in water-vapour production rate with decreasing heliocentric distance, measured by the instruments on-board the Rosetta spacecraft and the Philae lander. Our findings suggest that the pebbles observed to be abundant in protoplanetary discs around young stars provide the building material for comets and other minor bodies
Giapponismi italiani tra Otto e Novecento
Atti – ampliati e integrati – del colloquio «Giapponismi italiani tra Otto e Novecento» organizzato presso il Dipartimento di Civiltà e Forme del Sapere dell’Università di Pisa (Febbraio 2014)
- …