DNA G-quadruplex structures mould the DNA methylome

Control of DNA methylation level is critical for gene regulation, and the factors that govern hypomethylation at CpG islands (CGIs) are still being uncovered. Here, we provide evidence that G-quadruplex (G4) DNA secondary structures are genomic features that influence methylation at CGIs. We show that the presence of G4 structure is tightly associated with CGI hypomethylation in the human genome. Surprisingly, we find that these G4 sites are enriched for DNA methyltransferase 1 (DNMT1) occupancy, which is consistent with our biophysical observations that DNMT1 exhibits higher binding affinity for G4s as compared to duplex, hemi-methylated or single-stranded DNA. The biochemical assays also show that the G4 structure itself, rather than sequence, inhibits DNMT1 enzymatic activity. Based on these data, we propose that G4 formation sequesters DNMT1 thereby protecting certain CGIs from methylation and inhibiting local methylation.This work is supported by a core CRUK award (C14303/A17197). S.B. is a Senior Investigator of the Wellcome Trust (grant no. 099232/z/12/z). JS is a Marie Curie Fellow of the European Union (747297-QAPs-H2020-MSCA-IF-2016)

Risk Factors Affecting Traffic Accidents at Urban Weaving Sections: Evidence from China

As a critical configuration of interchanges, the weaving section is inclined to be involved in more traffic accidents, which may bring about severe casualties. To identify the factors associated with traffic accidents at the weaving section, we employed the multinomial logistic regression approach to identify the correlation between six categories of risk factors (drivers’ attributes, weather conditions, traffic characteristics, driving behavior, vehicle types and temporal-spatial distribution) and four types of traffic accidents (rear-end, side wipe, collision with fixtures and rollover) based on 768 accident samples of an observed weaving section from 2016 to 2018. The modeling results show that drivers’ gender and age, weather condition, traffic density, weaving ratio, vehicle speed, lane change behavior, private cars, season, time period, day of week and accident location are important factors affecting traffic accidents at the weaving section, but they have different contributions to the four traffic accident types. The results also show that traffic density of ≥31 vehicle/100 m has the highest risk of causing rear-end accidents, weaving ration of ≥41% has the highest possibility to bring about a side wipe incident, collision with fixtures is the most likely to happen in snowy weather, and rollover is the most likely incident to occur in rainy weather

Association of systemic inflammation response index with all-cause mortality as well as cardiovascular mortality in patients with chronic kidney disease

BackgroundChronic Kidney Disease (CKD) stands as a formidable health challenge, recognized not only for its growing prevalence but also for its association with elevated mortality rates. Emerging evidence suggests that CKD is inherently linked to inflammatory processes, marking it as an inflammatory disorder. In this landscape, the systemic inflammatory response index (SIRI) emerges as a novel inflammation marker, yet to be applied for assessing the risk of mortality in CKD patients.ObjectiveThis study aims to investigate the prognostic significance of the SIRI in all-cause and cardiovascular disease (CVD) mortality among patients with CKD.MethodThis study conducted a retrospective observational study using the National Health and Nutrition Examination Survey (NHANES) database, encompassing data from 1999 to 2018. This analysis included 9,115 CKD patients, categorized based on SIRI quartiles. Key outcomes were all-cause and CVD mortality, analyzed using Kaplan–Meier survival curves, restricted cube splines (RCS) and cox proportional hazards models.ResultIn this study of 9,115 CKD patients, the Kaplan–Meier survival analysis revealed a greater incidence of all-cause death among groups with higher SIRI (P-log rank <0.001). In the fully adjusted model (Model 3), each unit increase in SIRI led to a 20% increase in the risk of all-cause mortality. Additionally, higher SIRI quartiles (Q3 and Q4) were associated with increased risk compared to the lowest quartile (Q1) (Q3: HR: 1.16, 95% CI: 1.01–1.34; Q4: HR: 1.63, 95% CI: 1.40–1.90; P for trend <0.001). Similarly, for CVD mortality, each unit increase in SIRI in Model 3 increased the risk by 33%, with Q3 and Q4 showing higher risk than Q1 (Q3: HR: 1.39, 95% CI: 1.11–1.70; Q4: HR: 2.26, 95% CI: 1.72–2.98; P for trend <0.001).ConclusionSIRI was positively associated with all-cause and CVD mortality in patients with CKD

On functional limits of short- and long-memory linear processes with GARCH(1,1) noises

This paper considers the short- and long-memory linear processes with GARCH (1,1) noises. The functional limit distributions of the partial sum and the sample autocovariances are derived when the tail index alpha is in (0, 2), equal to 2, and in (2, infinity), respectively. The partial sum weakly converges to a functional of alpha-stable process when alpha < 2 and converges to a functional of Brownian motion when alpha >= 2. When the process is of short-memory and alpha < 4, the autocovariances converge to functionals of alpha/2-stable processes; and if alpha >= 4, they converge to functionals of Brownian motions. In contrast, when the process is of long-memory, depending on alpha and beta (the parameter that characterizes the long-memory), the autocovariances converge to either (i) functionals of alpha/2-stable processes; (ii) Rosenblatt processes (indexed by beta, 1/2 < beta < 3/4); or (iii) fanctionals of Brownian motions. The rates of convergence in these limits depend on both the tail index alpha and whether or not the linear process is short- or long-memory. Our weak convergence is established on the space of cadlag functions on [0, 1] with either (i) the J(1) or the M-1 topology (Skorokhod, 1956); or (ii) the weaker form S topology (Jakubowski, 1997). Some statistical applications are also discussed. (C) 2014 Elsevier B.V. All rights reserved

Selective Adsorption of Pb(II) from Aqueous Solution by Triethylenetetramine-Grafted Polyacrylamide/Vermiculite

Amine groups play significant roles in polymeric composites for heavy metals removal. However, generating a composite with a large number of functional and stable amine groups based on clay is still a challenge. In this work, a new amine-functionalized adsorbent based on acid-activated vermiculite (a-Verm) was prepared by organic modification of silane coupling agent as bridge, followed by in situ polymerization of acrylamide (AM) and further grafting of triethylene tetramine (TETA). The obtained polymeric composite g-PAM/OVerm was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared (FTIR), thermal analysis (TG/DTG), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analyses, confirming that amine groups were successfully grafted onto the surface of Verm. The efficacy g-PAM/OVerm for removing Pb(II) was tested. The adsorption equilibrium data on g-PAM/OVerm was in good accordance with the Langmuir adsorption isotherms, and the adsorption maximal value of Pb(II) was 219.4 mg·g−1. The adsorption kinetic data fit the pseudo-second-order kinetic model well. Additionally, g-PAM/OVerm has better selectivity for Pb(II) ion in comparison with Zn(II), Cd(II) and Cu(II) ions. The present work shows that g-PAM/OVerm holds great potential for removing Pb(II) from wastewater, and provides a new and efficient method for the removal of heavy metal ions from industrial wastewater

Tunable white light in trivalent europium single doped tin fluorophosphates ultra-low melting glass

International audienceIn recent years, low melting temperature glasses have received wide attention as the hosts of phosphor-converted light emitting diodes (pc-WLED). In this work, a series of trivalent europium doped tin fluorophosphates glasses were prepared by conventional melting method. Under ultraviolet excitation, the blue-green broadband emission from Sn 2+ activation centers in the glass matrix and the red emission of Eu 3+ ions together constituted a cool white luminescence. The spectra analysis was used to demonstrate the energy transfer between Sn 2+ centers and Eu 3+ ions. The results showed that Sn 2+ and Eu 3+ possessed independent intrinsic emission and mutual energy transfer simultaneously. The 5 D 4 and 5 G 2 excited states of Eu 3+ ion favored the energy transfer to Sn 2+ center, the 5 L 6 excited state of Eu 3+ ion would absorb more of the energy by the Sn 2+ ground state excitation to contribute on red emission. Therefore, the fluorescent glass can transform cool white light to warm white light by changing the excitation wavelength. The tunable white light is obtained in the WLED devices built with the glass and commercial UV chips

Synthesis of a three-dimensional network sodium alginate–poly(acrylic acid)/attapulgite hydrogel with good mechanic property and reusability for efficient adsorption of Cu2+ and Pb2+

International audienceWater pollution caused by heavy metals has dramatically impacted ecosystems in recent years. For instance, 45.4% of lakes in China are in the category of moderate to high risk of toxic metal pollution, due to excessive mining. There is, therefore, a need for efficient techniques of metal decontamination. Hydrogels are gaining interest as heavy metal adsorbents because of their easy separation, but hydrogel applications are limited due to their poor mechanical property. Here we solve this problem by introducing natural attapulgite into the sodium alginate-poly(acrylic acid) semi-interpenetrating polymer network of the hydrogel. Results show that the compressive stress of the hydrogel with 10% attapulgite, of 1.230 Mpa, was 4.1 times higher than that of pure hydrogel, of 0.299 MPa. The adsorption capacity of hydrogel with 10% attapulgite was high, of 272.8 mg/g for Cu 2+ and 391.7 mg/g for Pb 2+. Even after five cycles of adsorption, the hydrogel with 10% attapulgite still adsorbs 261.7 mg/g Cu 2+ and 368.1 mg/g Pb 2+. Our findings thus reveal that network-structured sodium alginate-poly(acrylic acid)/attapulgite hydrogel holds great potential as an efficient and recyclable adsorbent for heavy metal removal