62 research outputs found

    Two hydroxy pyridinecarboxylic acid derivatives as a possible chelating agents in neurodegenerative disease; equilibrium complexation studies with Cu(II), Zn(II).

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    The metal ion chelators 4-hydroxy-5-methyl-3-pyridinecarboxylic acid (DQ5) and 1,5-dimethyl-4-hydroxy-3-pyridinecarboxylic acid (DQ715) and Cu(II) and Zn(II) were investigated with the aim to restore the homeostasis of the brain Cu(II) and Zn(II) in neurodegenerative diseases. The proton dissociation constants of the ligands, the stability constants, and the coordination modes of the metal complexes formed were determined by pH-potentiometric, and spectral (UV–Vis and EPR or 1H NMR) methods. The results show that in slightly acidic and neutral pH range mono and bis complexes are formed through bidentate coordination of the ligands. The biological MTT-test reveals that the DQ715 ligand is able to lower the cytotoxic effect of Cu(II) in human embryonic kidney HEK-293 cells. Our studies revealed, however, that none of the chelators were efficient enough to withdraw these metal ions from the amyloid aggregates

    Gamma-ray polarization constraints on Planck scale violations of special relativity

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    Using recent polarimetric observations of the Crab Nebula in the hard X-ray band by INTEGRAL, we show that the absence of vacuum birefringence effects constrains O(E/M) Lorentz violation in QED to the level |\xi| < 9x10^{-10} at three sigma CL, tightening by more than three orders of magnitude previous constraints. We show that planned X-ray polarimeters have the potential the potential to probe |\xi|~ 10^{-16} by detecting polarization in active galaxies at red-shift ~1.Comment: 4 pages, 3 figure

    Thermodynamics and statistical mechanics of frozen systems in inherent states

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    We discuss a Statistical Mechanics approach in the manner of Edwards to the ``inherent states'' (defined as the stable configurations in the potential energy landscape) of glassy systems and granular materials. We show that at stationarity the inherent states are distributed according a generalized Gibbs measure obtained assuming the validity of the principle of maximum entropy, under suitable constraints. In particular we consider three lattice models (a diluted Spin Glass, a monodisperse hard-sphere system under gravity and a hard-sphere binary mixture under gravity) undergoing a schematic ``tap dynamics'', showing via Monte Carlo calculations that the time average of macroscopic quantities over the tap dynamics and over such a generalized distribution coincide. We also discuss about the general validity of this approach to non thermal systems.Comment: 10 pages, 16 figure

    High-Pressure Transformation of SiO2 Glass from a Tetrahedral to an Octahedral Network:A Joint Approach Using Neutron Diffraction and Molecular Dynamics

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    International audienceA combination of in situ high-pressure neutron diffraction at pressures up to 17.5(5) GPa and moleculardynamics simulations employing a many-body interatomic potential model is used to investigate thestructure of cold-compressed silica glass. The simulations give a good account of the neutron diffractionresults and of existing x-ray diffraction results at pressures up to ∼60 GPa. On the basis of the moleculardynamics results, an atomistic model for densification is proposed in which rings are “zipped” by a pairingof five- and/or sixfold coordinated Si sites. The model gives an accurate description for the dependence ofthe mean primitive ring size hni on the mean Si-O coordination number, thereby linking a parameter that issensitive to ordering on multiple length scales to a readily measurable parameter that describes the localcoordination environment

    Guidelines on the management of valvular heart disease: The Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology.

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    80These guidelines focus on valvular heart disease in adults and adolescents, are oriented towards management, and will not deal with endocarditis and congenital valve diseases in adults and adolescents, since recent guidelines have been produced by the ESC on these topics. Although valvular heart disease is less common in industrialized countries than coronary disease, heart failure, or hypertension, guidelines are needed in this field for several reasons: valvular heart disease is common and often requires intervention; substantial advances have been made in the understanding of its pathophysiology; the patient population has changed with a continuous decline of acute rheumatic fever and an increased incidence of degenerative valvular diseases in industrialized countries. The incidence of endocarditis remains stable and other causes of valve disease are rare. Because of the predominance of degenerative valve disease, the two most frequent valve diseases are now calcific aortic stenosis and mitral regurgitation. Aortic regurgitation and mitral stenosis have become less common. Diagnosis is now dominated by echocardiography, which has become the standard to evaluate valve structure and function. Treatment has not only developed through the continuing progress in prosthetic valve technology, but has also been reoriented by the development of conservative surgical approaches and the introduction of percutaneous interventional techniques.openopenVahanian, A; Baumgartner, ; H, ; Bax, ; J, ; Butchart, ; E, ; Dion, ; R, ; Filippatos, ; G, ; Flachskampf, ; F, ; Hall, ; R, ; Iung, ; B, ; Kasprzak, ; J, ; Nataf, ; P, ; Tornos, ; P, ; Torracca, ; L, ; Wenink, ; A, ; Silvia, ; Priori, G.; Blanc, Jean-Jacques; Andrzej, ; Budaj, ; John, ; Camm, ; Veronica, ; Dean, ; Jaap, ; Deckers, ; Kenneth, ; Dickstein, ; John, ; Lekakis, ; Keith, ; Mcgregor, ; Marco, ; Metra, ; João, ; Morais, ; Ady, ; Osterspey, ; Juan, ; Tamargo, ; Luis, José; Zamorano, ; Annalisa, ; Angelini, ; Manuel, ; Antunes, ; Angel, Miguel; Fernandez, Garcia; Christa, ; Gohlke-Baerwolf, ; Gilbert, ; Habib, ; John, ; Mcmurray, ; Catherine, ; Otto, ; Luc, ; Pierard, ; Josè, ; Pomar, L.; Bernard, ; Prendergast, ; Raphael, ; Rosenhek, ; Sousa, Miguel; Uva, ; Juan, ; Tamargo,Vahanian, A; Baumgartner, ; H, ; Bax, ; J, ; Butchart, ; E, ; Dion, ; R, ; Filippatos, ; G, ; Flachskampf, ; F, ; Hall, ; R, ; Iung, ; B, ; Kasprzak, ; J, ; Nataf, ; P, ; Tornos, ; P, ; Torracca, ; L, ; Wenink, ; A, ; Silvia, ; Priori, G.; Blanc, Jean Jacques; Andrzej, ; Budaj, ; John, ; Camm, ; Veronica, ; Dean, ; Jaap, ; Deckers, ; Kenneth, ; Dickstein, ; John, ; Lekakis, ; Keith, ; Mcgregor, ; Marco, ; Metra, Marco; João, ; Morais, ; Ady, ; Osterspey, ; Juan, ; Tamargo, ; Luis, José; Zamorano, ; Annalisa, ; Angelini, ; Manuel, ; Antunes, ; Angel, Miguel; Fernandez, Garcia; Christa, ; Gohlke, Baerwolf; Gilbert, ; Habib, ; John, ; Mcmurray, ; Catherine, ; Otto, ; Luc, ; Pierard, ; Josè, ; Pomar, L.; Bernard, ; Prendergast, ; Raphael, ; Rosenhek, ; Sousa, Miguel; Uva, ; Juan, ; Tamargo

    Life, time, and the organism:Temporal registers in the construction of life forms

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    In this paper, we articulate how time and temporalities are involved in the making of living things. For these purposes, we draw on an instructive episode concerning Norfolk Horn sheep. We attend to historical debates over the nature of the breed, whether it is extinct or not, and whether presently living exemplars are faithful copies of those that came before. We argue that there are features to these debates that are important to understanding contemporary configurations of life, time and the organism, especially as these are articulated within the field of synthetic biology. In particular, we highlight how organisms are configured within different material and semiotic assemblages that are always structured temporally. While we identify three distinct structures, namely the historical, phyletic and molecular registers, we do not regard the list as exhaustive. We also highlight how these structures are related to the care and value invested in the organisms at issue. Finally, because we are interested ultimately in ways of producing time, our subject matter requires us to think about historiographical practice reflexively. This draws us into dialogue with other scholars interested in time, not just historians, but also philosophers and sociologists, and into conversations with them about time as always multiple and never an inert background

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Re-emergence of enterovirus D68 in Europe after easing the COVID-19 lockdown, September 2021

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    We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe

    Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis

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    BackgroundHistologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD.MethodsThis was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0–4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0–2 vs F3 vs F4; LSM: 2·67; NFS: 0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226.FindingsOf 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44–63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33–91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62–0·81) for histology, 0·76 (0·70–0·83) for LSM-VCTE, 0·74 (0·64–0·82) for FIB-4, and 0·70 (0·63–0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression.InterpretationSimple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases
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