444 research outputs found

    DTI Parameter Optimisation for Acquisition at 1.5T: SNR Analysis and Clinical Application

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    Background. Magnetic Resonance (MR) diffusion tensor imaging (DTI) is able to quantify in vivo tissue microstructure properties and to detect disease related pathology of the central nervous system. Nevertheless, DTI is limited by low spatial resolution associated with its low signal-to-noise-ratio (SNR). Aim. The aim is to select a DTI sequence for brain clinical studies, optimizing SNR and resolution. Methods and Results. We applied 6 methods for SNR computation in 26 DTI sequences with different parameters using 4 healthy volunteers (HV). We choosed two DTI sequences for their high SNR, they differed by voxel size and b-value. Subsequently, the two selected sequences were acquired from 30 multiple sclerosis (MS) patients with different disability and lesion load and 18 age matched HV. We observed high concordance between mean diffusivity (MD) and fractional anysotropy (FA), nonetheless the DTI sequence with smaller voxel size displayed a better correlation with disease progression, despite a slightly lower SNR. The reliability of corpus callosum (CC) fiber tracking with the chosen DTI sequences was also tested. Conclusions. The sensitivity of DTI-derived indices to MS-related tissue abnormalities indicates that the optimized sequence may be a powerful tool in studies aimed at monitoring the disease course and severity

    Analysis of gut microbiota in rheumatoid arthritis patients. Disease-related dysbiosis and modifications induced by etanercept

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    A certain number of studies were carried out to address the question of how dysbiosis could affect the onset and development of rheumatoid arthritis (RA), but little is known about the reciprocal influence between microbiota composition and immunosuppressive drugs, and how this interaction may have an impact on the clinical outcome. The aim of this study was to characterize the intestinal microbiota in a groups of RA patients treatment-naïve, under methotrexate, and/or etanercept (ETN). Correlations between the gut microbiota composition and validated immunological and clinical parameters of disease activity were also evaluated. In the current study, a 16S analysis was employed to explore the gut microbiota of 42 patients affected by RA and 10 healthy controls. Disease activity score on 28 joints (DAS-28), erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti-cyclic citrullinated peptides, and dietary and smoking habits were assessed. The composition of the gut microbiota in RA patients free of therapy is characterized by several abnormalities compared to healthy controls. Gut dysbiosis in RA patients is associated with different serological and clinical parameters; in particular, the phylum of Euryarchaeota was directly correlated to DAS and emerged as an independent risk factor. Patients under treatment with ETN present a partial restoration of a beneficial microbiota. The results of our study confirm that gut dysbiosis is a hallmark of the disease, and shows, for the first time, that the anti-tumor necrosis factor alpha (TNF-α) ETN is able to modify microbial communities, at least partially restoring a beneficial microbiota

    Dental anomalies : prevalence and associations between them in a large sample of non-orthodontic subjects, a cross-sectional study

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    Background: To analyze the prevalence and associations between dental anomalies detectable on panoramic radiographs in a sample of non-orthodontic growing subjects. Methods: For this cross-sectional study, digital panoramic radiographs of 5005 subjects were initially screened from a single radiographic center in Rome. Inclusion criteria were: subjects who were aged 8–12 years, Caucasian, and had good diagnostic quality radiographs. Syndromic subjects, those with craniofacial malformation, or orthodontic patients were excluded and this led to a sample of 4706 subjects [mean (SD) age = 9.6 (1.2) years, 2366 males and 2340 females]. Sample was subsequently divided into four subgroups (8, 9, 10, and 11–12 year-old groups). Two operators examined panoramic radiographs to observe the presence of common dental anomalies. The prevalence and associations between dental anomalies were also investigated. Results: The overall prevalence of dental anomalies was 20.9%. Approximately, 17.9% showed only one anomaly, 2.7% two anomalies, while only 0.3% had more than two anomalies. The most frequent anomalies were the displacement of maxillary canine (7.5%), hypodontia (7.1%), impacted teeth (3.9%), tooth ankylosis (2.8%), and tooth transposition (1.4%). The lower right second premolar was the most frequent missing teeth; 3.7% had only one tooth agenesis, and 0.08% had six or more missing tooth (Oligodontia). Mesiodens was the most common type of supernumerary tooth (0.66%). Two subjects had taurodontic tooth (0.04%). Tooth transpositions and displacement of maxillary canine were seen in 1.4 and 7.5%, retrospectively (approximately 69 and 58% were in the 8 and 9 year-old groups, retrospectively). Significant associations were detected between the different dental anomalies (P < .05). Conclusions: The results of our study revealed significant associations among different dental anomalies and provide further evidences to support common etiological factors

    Laser production of gas phase complexes of metal α-aminophosphonic acid mixtures and their role in chiral recognition

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    Clusters between first-group metal ions and chiralα-aminophosphonic acids have been readily generated by Pulsed Laser Ablation (PLA) and by Electrospray Ionization (ESI) and their fragmentation investigated by mass spectrometry. The complexes studied have the general formula[Me(I)Cl2]+, where Me(I) is H, Li, Na, or K, C is (R)-(—)-(1-aminoethyl) phosphonic acid(ER)and (S)-(+)-(1-aminoethyl) phosphonic acid(ES),(1R)-(+)-(1-amino-2-methylpropyl) phosphonic acid(PR)and (1S)-(—)-(1-amino-2-methylpropyl) phosphonic acid(PS),(1R)-(-)-(1-amino-hexyl) phosphonic acid (HR) and (1S)-(+)-(1-amino-hexyl) phosphonic acid (HS), o-phospho-L-serine (SS)ando-phospho-D-serine(SR), and L is a referenceα-aminophosphonic acid (E, P, H or S) of defined configuration. Collision induced dissociation (CID) of diastereomeric[Me(I)Cl2]+complexes leads to fragmentation patterns characterized by[Me(I)Cl]+/[Me(I)L2]+abundance ratios which depend upon the configuration of solute C. These different spectral features were correlated to the different stability of the diastereomeric[Me(I)CRL]+and[Me(I)CSL]+complexes in the gas phase

    Factors Determining the Superior Performance of Lipid/DNA/Protammine Nanoparticles over Lipoplexes.

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    The utility of using a protammine/DNA complex coated with a lipid envelope made of cationic 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) for transfecting CHO (Chinese hamster ovary cells), HEK293 (human embryonic kidney cells), NIH 3T3 (mouse embryonal cells), and A17 (murine cancer cells) cells was examined. The widely used DOTAP/DNA lipoplex was employed as a reference. In all the tested cell lines lipid/protamine/DNA (LPD) nanoparticles were more e!cient in transfecting cells than lipoplexes even though the lipid composition of the lipid envelope was the same in both devices. Physical!chemical properties were found to control the ability of nanocarriers to release DNA upon interaction with cellular membranes. LPD complexes easily release their DNA payload, while lipoplexes remain largely intact and accumulate at the cell nucleus. Collectively, these data explain why LPD nanoparticles often exhibit superior performances compared to lipoplexes in trasfecting cells and represent a promising class of nanocarriers for gene delivery

    Pure Hydrogen Production from Steam Reforming of Bio-Sources

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    Two synthetic mixtures simulating biogas (CH4 /CO2 = 66.2/33.8) and bioethanol (H2O/EtOH = 13/1) have been used for producing hydrogen by steam reforming reaction in a commercial dense self-supported Pd-Ag membrane reactor. The experimental campaign was subdivided into two parts. Firstly, we studied biogas steam reforming reaction, evaluating the reaction pressure influence (between 200 and 350 kPa) at 450°C, H2O/CH4feed molar ratio = 4/1, GHSV =2370h-1, sweep gas flow rate (N2) = 28.55 mL/min and countercurrent configuration. As best result, we reached 60% CH4 conversion and 40% hydrogen recovery at 350kPa.Successively, we carried out bioethanol steam reforming reaction studying the influence of reaction temperature between 350 and 400°C at 300 kPa of reaction pressure, GHSV=700 h-1 in the presence of sweep gas (N2 = 28.55 mL/min) and countercurrent configuration, obtaining - at 400 °C - maximum ethanol conversion, hydrogen yield and recovery equal to 70%, 50% and 65%, respectively. In addition, we compared the membrane reactor performance with a traditional reactor exercised at the same conditions, only varying the reaction pressure between 200 and 300 kPa. The aim of this work is constituted by the pure hydrogen production from bio-sources exploitation in membrane reactors at bench scale, starting with the utilization of commercial membranes available in the market and in the perspective of scaling up the process for potential industrial development

    Motivation, Perception, and Behavior of the Adult Orthodontic Patient: A Survey Analysis

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    Purpose. The article is aimed at improving the understanding of the sociocultural profile of adult orthodontic patients and their expectations. In particular, it addresses three main aspects: the motivation and needs that underpin the decision to start orthodontic treatment, how it influences the patients’ daily life, and the different oral hygiene demands. Materials and Methods. An online survey was completed by 276 patients undergoing orthodontic treatment with different techniques. The questions asked concerned gender, age, type of appliance, any previous orthodontic treatments, type of any previous retainers, reasons for therapy, satisfaction, pain, problems in eating, daily number of teeth brushings and flossings before and during the treatment, perception of cost, sensation of visibility of the appliance, and if they would recommend orthodontic treatment. Results. A significant role within our sample is played by gender; 87.94% consisted of female patients out of which 72.57% wanted to improve their aesthetics, while only 54.84% of male patients cited the same reason. Invisible aligners were preferred by 67.70% of the patients due to them being considered the least painful, causing the fewest problems with eating, and the least visible. Metal braces were perceived as the less expensive treatment. Over a third of the patients (33.85%) had previously undergone orthodontic treatment, among them 54.05% wore a mobile retainer, 31.08% a fixed one, and 14.86% both. Daily tooth brushing and flossing increased during therapy with clear aligners by 48.94% and 126.39%, respectively. Conclusions. The greatest demand for orthodontic treatments comes from women, as they pay more attention to aesthetics, which makes the clear aligners the most common choice. The relapse after orthodontic treatment seems to cause a higher demand for retreatment, and oral hygiene habits significantly improve during orthodontic treatment, especially with the clear aligners
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