Long-term whole blood DNA preservation by cost-efficient cryosilicification

This work was supported by the National Natural Science Foundation of China (21972047 to W.Z., 52003086 to Q.L.), Guangdong Provincial Pearl River Talents Program (2019QN01Y314 to Q.L.), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2019ZT08Y318 to W.Z.), Natural Science Foundation of Guangdong Province, China (2021A1515010724 to Q.L.), China Postdoctoral Science Foundation (2020M672625, 2021T140213 to Q.L.), Science and Technology Project of Guangzhou, China (202102020352 to W.Z., 202102020259 to Q.L.), the Fundamental Research Funds for the Central Universities of China. The authors thank the support from the Guangzhou Women and Children’s Medical Center and Laboratory Animal Research Center of the South China University of Technology. S.W. acknowledges funding from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs.Deoxyribonucleic acid (DNA) is the blueprint of life, and cost-effective methods for its long-term storage could have many potential benefits to society. Here we present the method of in situ cryosilicification of whole blood cells, which allows long-term preservation of DNA. Importantly, our straightforward approach is inexpensive, reliable, and yields cryosilicified samples that fulfill the essential criteria for safe, long-term DNA preservation, namely robustness against external stressors, such as radical oxygen species or ultraviolet radiation, and long-term stability in humid conditions at elevated temperatures. Our approach could enable the room temperature storage of genomic information in book-size format for more than one thousand years (thermally equivalent), costing only 0.5 $/person. Additionally, our demonstration of 3D-printed DNA banking artefacts, could potentially allow 'artificial fossilization'.Publisher PDFPeer reviewe

P(I) Release Limits the Intrinsic and RNA-Stimulated ATPase Cycles of DEAD-Box Protein 5 (Dbp5).

mRNA export from the nucleus depends on the ATPase activity of the DEAD-box protein Dbp5/DDX19. Although Dbp5 has measurable ATPase activity alone, several regulatory factors (e.g., RNA, nucleoporin proteins, and the endogenous small molecule InsP6) modulate catalytic activity in vitro and in vivo to facilitate mRNA export. An analysis of the intrinsic and regulator-activated Dbp5 ATPase cycle is necessary to define how these factors control Dbp5 and mRNA export. Here, we report a kinetic and equilibrium analysis of the Saccharomyces cerevisiae Dbp5 ATPase cycle, including the influence of RNA on Dbp5 activity. These data show that ATP binds Dbp5 weakly in rapid equilibrium with a binding affinity (KT~4 mM) comparable to the KM for steady-state cycling, while ADP binds an order of magnitude more tightly (KD~0.4 mM). The overall intrinsic steady-state cycling rate constant (kcat) is limited by slow, near-irreversible ATP hydrolysis and even slower subsequent phosphate release. RNA increases kcat and rate-limiting Pi release 20-fold, although Pi release continues to limit steady-state cycling in the presence of RNA, in conjunction with RNA binding. Together, this work identifies RNA binding and Pi release as important biochemical transitions within the Dbp5 ATPase cycle and provides a framework for investigating the means by which Dbp5 and mRNA export is modulated by regulatory factors.E.V.W. is supported by National Science Foundation Graduate Research Fellowship No. DGE-1122492 and J.V. is supported by an Alberta Innovates Health Solutions Postdoctoral Fellowship. M.M. and Y.M. were supported by a Senior Research Fellowship from the Wellcome Trust (101908/Z/13/Z) and by National Institutes of Health grant R01 GM102869. Research support for B.M. was provided by the Natural Sciences and Engineering Research Council of Canada (RGPIN 435380), Canada Foundation for Innovation (31271), Government of Alberta Research Capacity Program, and Canada Research Chairs program.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jmb.2015.12.01

Status and Prospects of ZnO-Based Resistive Switching Memory Devices

In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges

Muscle Fatigue Analysis of the Deltoid during Three Head-Related Static Isometric Contraction Tasks

This study aimed to investigate the fatiguing characteristics of muscle-tendon units (MTUs) within skeletal muscles during static isometric contraction tasks. The deltoid was selected as the target muscle and three head-related static isometric contraction tasks were designed to activate three heads of the deltoid in different modes. Nine male subjects participated in this study. Surface electromyography (SEMG) signals were collected synchronously from the three heads of the deltoid. The performances of five SEMG parameters, including root mean square (RMS), mean power frequency (MPF), the first coefficient of autoregressive model (ARC1), sample entropy (SE) and Higuchi’s fractal dimension (HFD), in quantification of fatigue, were evaluated in terms of sensitivity to variability ratio (SVR) and consistency firstly. Then, the HFD parameter was selected as the fatigue index for further muscle fatigue analysis. The experimental results demonstrated that the three deltoid heads presented different activation modes during three head-related fatiguing contractions. The fatiguing characteristics of the three heads were found to be task-dependent, and the heads kept in a relatively high activation level were more prone to fatigue. In addition, the differences in fatiguing rate between heads increased with the increase in load. The findings of this study can be helpful in better understanding the underlying neuromuscular control strategies of the central nervous system (CNS). Based on the results of this study, the CNS was thought to control the contraction of the deltoid by taking the three heads as functional units, but a certain synergy among heads might also exist to accomplish a contraction task

Fluorine-Containing Flow Modifier for BN/PPS Composites Enabled by Low Surface Energy

In this study, a fluorine-containing flow modifier (Si-DF) with low surface energy is successfully synthesized, which is applied to fabricate ideal electronic packaging materials (BN/PPS composites) with high thermal conductivity, excellent dielectric properties, processability, and toughness by conventional melt blending. Si-DPF is located at the interface between the BN fillers and the PPS matrix, which not only improves the dispersion of BN fillers but also strengthens the interaction. With the help of 5 wt% Si-DF, BN/PPS/Si-DF (70/25/5) still exhibits the high thermally conductive coefficient (3.985 W/m·K) and low dielectric constant (3.76 at 100 MHz) although BN fillers are loaded as high as 70 wt%. Moreover, the sample processes a lower stable torque value (2.5 N·m), and the area under the stress–strain curves is also increased. This work provides an efficient way to develop high-performance polymer-based composites with high thermally conductive coefficients and low dielectric constants for electronic packaging applications

Spatial Distribution and Regulating Factors of Soil Nutrient Stocks in Afforested Dump of Pingshuo Opencast Coalmine, China

Determining the regulating factors of soil nutrient variations can guide the implementation of land reclamation measures in opencast coalmine regions. In this study, 132 soil samples were collected at 22 sample sites in the South Dump of Pingshuo opencast coalmine, and soil physicochemical properties were separately measured to obtain the related soil information. Geostatistical analyses were employed to analyze the spatial distribution patterns of soil organic carbon stocks (SOCD), total nitrogen stocks (TND), available phosphorus stocks (APD), and available potassium stocks (AKD) at 0–60 cm. The results showed that the spatial distributions of these soil nutrient stocks were characterized by moderate (TND) to strong (SOCD, APD, and AKD) spatial dependence. Meanwhile, the values of SOCD (16.4–60.1 Mg ha−1) and TND (1.9–15.5 Mg ha−1) were much higher than those of APD (0.022–0.095 Mg ha−1) and AKD (0.31–1.40 Mg ha−1). The statistical analyses indicated that the influence of afforestation on SOCD, TND, APD, and AKD was not significant, and the dynamic variations of soil nutrient contents were mainly regulated by soil pH in the South Dump. The findings of this study can provide some scientific guidance for soil nutrient management in the opencast coalmine regions of similar ecosystems

The Fabrication of High-Hardness and Transparent PMMA-Based Composites by an Interface Engineering Strategy

The high-hardness and transparent PMMA-based composites play a significant role in modern optical devices. However, a well-known paradox is that conventional PMMA-based composites with high loadings of nanoparticles usually possess high surface hardness at the cost of poor transparency and toughness due to the aggregation of nanoparticles. In this work, ideal optical materials (SiO2/PMMA composites) with high transparency and high surface hardness are successfully fabricated through the introduction of the flow modifier Si-DPF by conventional melt blending. Si-DPF with low surface energy and high transparency, which is located at the SiO2/PMMA interface, and nano-SiO2 particles are homogeneously dispersed in the PMMA matrix. As an example, the sample SiO2/PMMA/Si-DPF (30/65/5) shows outstanding transparency (>87.2% transmittance), high surface hardness (462.2 MPa), and notched impact strength (1.18 kJ/m2). Moreover, SiO2/PMMA/Si-DPF (30/65/5) also presents a low torque value of composite melt (21.7 N⋅m). This work paves a new possibility for the industrial preparation of polymer-based composites with excellent transparency, surface hardness, processability, and toughness

The nucleoporin Gle1 activates DEAD-box protein 5 (Dbp5) by promoting ATP binding and accelerating rate limiting phosphate release.

The DEAD-box protein Dbp5 is essential for RNA export, which involves regulation by the nucleoporins Gle1 and Nup159 at the cytoplasmic face of the nuclear pore complex (NPC). Mechanistic understanding of how these nucleoporins regulate RNA export requires analyses of the intrinsic and activated Dbp5 ATPase cycle. Here, kinetic and equilibrium analyses of the Saccharomyces cerevisiae Gle1-activated Dbp5 ATPase cycle are presented, indicating that Gle1 and ATP, but not ADP-Pi or ADP, binding to Dbp5 are thermodynamically coupled. As a result, Gle1 binds Dbp5-ATP > 100-fold more tightly than Dbp5 in other nucleotide states and Gle1 equilibrium binding of ATP to Dbp5 increases >150-fold via slowed ATP dissociation. Second, Gle1 accelerated Dbp5 ATPase activity by increasing the rate-limiting Pi release rate constant ∼20-fold, which remains rate limiting. These data show that Gle1 activates Dbp5 by modulating ATP binding and Pi release. These Gle1 activities are expected to facilitate ATPase cycling, ensuring a pool of ATP bound Dbp5 at NPCs to engage RNA during export. This work provides a mechanism of Gle1-activation of Dbp5 and a framework to understand the joint roles of Gle1, Nup159, and other nucleoporins in regulating Dbp5 to mediate RNA export and other Dbp5 functions in gene expression