205 research outputs found

    Bayes Turchin analysis of X ray absorption data above the Fe L2,3 edges

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    Extended X ray absorption fine structure EXAFS data and magnetic EXAFS MEXAFS data were measured at two temperatures 180 K and 296 K in the energy region of the overlapping L edges of bcc Fe grown on a V 110 crystal surface. In combination with a Bayes Turchin data analysis procedure these measurements enable the exploration of local crystallographic and magnetic structures. The analysis determined the atomic like background together with the EXAFS parameters which consisted of 10 shell radii, the Debye Waller parameters, separated into structural and vibrational components, and the third cumulant of the first scattering path. The vibrational components for 97 different scattering paths were determined by a two parameter force field model using a priori values adjusted to Born von Karman parameters of inelastic neutron scattering data. The investigations of the system Fe V 110 demonstrate that the simultaneous fitting of atomic background parameters and EXAFS parameters can be performed reliably. Using the L2 and L3 components extracted from the EXAFS analysis and the rigid band model, the MEXAFS oscillations can only be described when the sign of the exchange energy is changed compared to the predictions of the Hedin Lundquist exchange and correlation functiona

    Perlite waste as a precursor for geopolymer formation.

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    Waste perlite can be reacted with alkaline solutions to form crystalline zeolite 4A and other minor crystalline phases. The fine majority fraction of the waste was fairly reactive and the coarse fraction largely acted as a filler. This geopolymer had poor compressive strength, but when perlite was used in conjunction with flyash, geopolymers of acceptable mechanical properties could be made. Perlite shows significant reaction with 10 Mol/L NaOH solution at ˜70°C, with hydroxysodalite appearing as a reaction product. © 2009, The Australian Ceramic Societ

    Protective effect of procyanidin-rich grape seed extract against Gram-negative virulence factors

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    Biofilm formation and lipopolysaccharide (LPS) are implicated in the pathogenesis of gastrointestinal (GI) diseases caused by Gram-negative bacteria. Grape seeds, wine industry by-products, have antioxidant and antimicrobial activity. In the present study, the protective effect of procyanidin-rich grape seed extract (prGSE), from unfermented pomace of Vitis vinifera L. cv Bellone, on bacterial LPS-induced oxidative stress and epithelial barrier integrity damage has been studied in a model of Caco-2 cells. The prGSE was characterized at the molecular level using HPLC and NMR. The in vitro activity of prGSE against formation of biofilm of Salmonella enterica subsp. enterica serovar Typhimurium and Escherichia coli was investigated. In vivo, prGSE activity using infected Galleria mellonella larvae has been evaluated. The results show that the prGSE, if administered with LPS, can significantly reduce the LPS-induced permeability alteration. Moreover, the ability of the extract to prevent Reactive Oxygen Species (ROS) production induced by the LPS treatment of Caco-2 cells was demonstrated. prGSE inhibited the biofilm formation of E. coli and S. Typhimurium. In terms of in vivo activity, an increase in survival of infected G. mellonella larvae after treatment with prGSE was demonstrated. In conclusion, grape seed extracts could be used to reduce GI damage caused by bacterial endotoxin and biofilms of Gram-negative bacteria

    Genome-based survey of the SARS-CoV-2 BF.7 variant from Asia

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    The SARS-CoV-2 BF.7 variant represents one of the most recent subvariant under monitoring. At the beginning of the 2023 if caused several concerns especially in Asia because of a resurge in COVID-19 cases. Here we perform a genome-based integrative approach on SARS-CoV-2 BF.7 in order to shed light on this emerging lineage and produce some consideration on its real dangerousness. Both genetic and structural data suggest that this new variant currently does not show evidence of an high expansion capability. It is very common in Asia, but it appears less virulent than other Omicron variants as proved by its relatively low evolutionary rate (5.62 x 10-4 subs/sites/years). The last plateau has been reached around December 14, 2022 and then the genetic variability, and thus the viral population size, no longer increased. As already seen for several previous variants, the features that may be theoretically related to advantages are due to genetic drift that allows to the virus a constant adaptability to the host, but is not strictly connected to a fitness advantage. These results have further pointed that the genome-based monitoring must continue uninterruptedly in order to be prepared and well documented on the real situation. This article is protected by copyright. All rights reserved

    Molecular in-depth on the epidemiological expansion of SARS-CoV-2 XBB.1.5

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    Since the beginning of the pandemic, the generation of new variants periodically recurs. The XBB.1.5 SARS-CoV-2 variant is one of the most recent. This research was aimed at verifying the potential hazard of this new subvariant. To achieve this objective, we performed a genome-based integrative approach, integrating results from genetic variability/phylodynamics with structural and immunoinformatic analyses to obtain as comprehensive a viewpoint as possible. The Bayesian Skyline Plot (BSP) shows that the viral population size reached the plateau phase on 24 November 2022, and the number of lineages peaked at the same time. The evolutionary rate is relatively low, amounting to 6.9 × 10−4 subs/sites/years. The NTD domain is identical for XBB.1 and XBB.1.5 whereas their RBDs only differ for the mutations at position 486, where the Phe (in the original Wuhan) is replaced by a Ser in XBB and XBB.1, and by a Pro in XBB.1.5. The variant XBB.1.5 seems to spread more slowly than sub-variants that have caused concerns in 2022. The multidisciplinary molecular in-depth analyses on XBB.1.5 performed here does not provide evidence for a particularly high risk of viral expansion. Results indicate that XBB.1.5 does not possess features to become a new, global, public health threat. As of now, in its current molecular make-up, XBB.1.5 does not represent the most dangerous variant

    Pre-treatment risk factors to predict early cisplatin-related nephrotoxicity in locally advanced head and neck cancer patients treated with chemoradiation: A single Institution experience

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    Objectives: Cisplatin is essential in the curative treatment of locally advanced head and neck squamous cell carcinoma (LA-HNSCC) patients. The assessment of risk factors to predict an early cisplatin-induced nephrotoxicity could help in better managing one of the most relevant cisplatin-related dose-limiting factors. Material and methods: We retrospectively collected data of LA-HNSCC patients treated at our Institution from 2008 to 2019. Patients received cisplatin in a curative setting concurrently with radiation. Acute Kidney Injury (AKI) was assessed as a dichotomous variable (CreaIncr) based on pre-treatment values, and values recorded at days 6-20 post-first cycle of cisplatin. Univariable logistic regression models were performed to investigate associations between CreaIncr and clinical characteristics. A multivariable logistic model on a priori selected putative covariates was performed. Results: Of the 350 LA-HNSCC treated patients, 204 were analyzed. Ninety (44 %) suffered from any grade AKI (grade I 51.1 %): out of them, 84.4 % received high-dose cisplatin (100 mg/m2 q21). On the univariable logistic regression model, male sex, age, serum uric acid, creatinine, concomitant drugs, and cisplatin schedule were significantly associated with a higher rate of AKI. At multivariable model, age (p = 0.034), baseline creatinine (p = 0.027), concomitant drugs (p = 0.043), and cisplatin schedule (one-day bolus or fractionated high-dose vs. weekly; p = 0.001) maintained their significant association. Conclusions: Identifying pre-treatment risk factors in LA-HNSCC patients may improve decision-making in a setting where cisplatin has a curative significance. A strict monitoring of AKI could avoid cisplatin dose adjustments, interruptions, and treatment delays, thus limiting a negative impact on outcomes

    HER2 status in recurrent/metastatic androgen receptor overexpressing salivary gland carcinoma patients

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    BackgroundOverexpression of human epidermal growth factor receptor type 2 (HER2) occurs in almost 25-30% of androgen receptor (AR)-positive salivary gland carcinomas (SGCs), notably salivary duct carcinoma (SDC) and adenocarcinoma not otherwise specified (NOS). In the last years, several studies have reported the clinical benefit of HER2 directed therapies in this setting. This work aims at describing the natural history of AR-positive recurrent/metastatic (R/M) SGC patients, based on HER2 amplification status.MethodsConsecutive R/M AR-positive SGC patients accessing our Institution from 2010 to 2021 were analyzed. Descriptive statistics and survival analyses were performed to present the clinical characteristics of the selected patients and the outcomes, based on HER2 status. A specific focus was dedicated to patients developing metastases to the central nervous system (CNS).ResultsSeventy-four R/M AR-positive SGC patients (72 men) were analyzed. Median follow-up was 36.18 months (95% CI 30.19-42.66). HER2 status was available in 62 cases (84%) and in 42% the protein was overexpressed (HER2+). Compared with patients with HER2- SGCs, in patients with HER2+ disease, HR for disease recurrence was 2.97 (95% CI 1.44-6.1, p=0.003), and HR for death from R/M disease was 3.22 (95% CI 1.39-7.49, p=0.007). Moreover, the HER2+ group showed a non-significant trend towards a higher prevalence of CNS metastases (40% vs. 24%, p=0.263). Patients developing CNS metastases had shorter survival than those who did not; at bivariate analysis (covariates: CNS disease and HER2 status), HER2 status demonstrated its independent prognostic significance.DiscussionIn our patient population, HER2 amplification was a negative prognostic factor, and it was associated with a non-statistically significant higher risk of developing CNS metastasis. Further studies are needed to explore the potential clinical benefit of tackling the two biological pathways (AR and HER2) in patients affected by this rare and aggressive malignancy

    Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

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    © The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
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