Facile construction of uniform ultramicropores in porous carbon for advanced sodium-ion battery

Facile fabrication of anode materials with low cost, good rate capability and high capacity is a critical factor towards developing sodium-ion battery for practical applications. Herein, a N, O co-doped porous carbon with uniform ultramicropores (NOPC-UM), is synthesized by an in-situ ultramicro templating strategy, and demonstrated as a high-performance sodium-ion storage material. Key to this strategy is employment of an inherent KCl as untramicro template, which leads to formation of uniform size of ultramicropores and heteroatoms (i.e., N and O) doping after high-temperature pyrolysis. The as-constructed NOPC-UM delivers a large capacity of 305 mAh g^-1, accompanying with a 93% specific capacity below 1.00 V, and superior cycling stability about 100% after 4000 cycles. These attractive electrochemical performances endow NOPC-UM with impressive potential use as anode materials of sodium-ion battery.

First-trimester pre-eclampsia biomarker profiles in Asian population: multicenter cohort study

OBJECTIVES

To (i) evaluate the applicability of the European-derived biomarker multiples of the median (MoM) formulae for risk assessment of preterm pre-eclampsia (PE) in seven Asian populations, spanning the east, southeast and south regions of the continent, (ii) perform quality-assurance (QA) assessment of the biomarker measurements and (iii) establish criteria for prospective ongoing QA assessment of biomarker measurements.

METHODS

This was a prospective, non-intervention, multicenter study in 4023 singleton pregnancies, at 11 to 13 + 6 weeks' gestation, in 11 recruiting centers in China, Hong Kong, India, Japan, Singapore, Taiwan and Thailand. Women were screened for preterm PE between December 2016 and June 2018 and gave written informed consent to participate in the study. Maternal and pregnancy characteristics were recorded and mean arterial pressure (MAP), mean uterine artery pulsatility index (UtA-PI) and maternal serum placental growth factor (PlGF) were measured in accordance with The Fetal Medicine Foundation (FMF) standardized measurement protocols. MAP, UtA-PI and PlGF were transformed into MoMs using the published FMF formulae, derived from a largely Caucasian population in Europe, which adjust for gestational age and covariates that affect directly the biomarker levels. Variations in biomarker MoM values and their dispersion (SD) and cumulative sum tests over time were evaluated in order to identify systematic deviations in biomarker measurements from the expected distributions.

RESULTS

In the total screened population, the median (95% CI) MoM values of MAP, UtA-PI and PlGF were 0.961 (0.956-0.965), 1.018 (0.996-1.030) and 0.891 (0.861-0.909), respectively. Women in this largely Asian cohort had approximately 4% and 11% lower MAP and PlGF MoM levels, respectively, compared with those expected from normal median formulae, based on a largely Caucasian population, whilst UtA-PI MoM values were similar. UtA-PI and PlGF MoMs were beyond the 0.4 to 2.5 MoM range (truncation limits) in 16 (0.4%) and 256 (6.4%) pregnancies, respectively. QA assessment tools indicated that women in all centers had consistently lower MAP MoM values than expected, but were within 10% of the expected value. UtA-PI MoM values were within 10% of the expected value at all sites except one. Most PlGF MoM values were systematically 10% lower than the expected value, except for those derived from a South Asian population, which were 37% higher.

CONCLUSIONS

Owing to the anthropometric differences in Asian compared with Caucasian women, significant differences in biomarker MoM values for PE screening, particularly MAP and PlGF MoMs, were noted in Asian populations compared with the expected values based on European-derived formulae. If reliable and consistent patient-specific risks for preterm PE are to be reported, adjustment for additional factors or development of Asian-specific formulae for the calculation of biomarker MoMs is required. We have also demonstrated the importance and need for regular quality assessment of biomarker values. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Carbon Dots as a Protective Agent Alleviating Abiotic Stress on Rice (Oryza sativa L.) through Promoting Nutrition Assimilation and the Defense System

Abiotic stress severely threatens agriculture. Herein, we studied the effect of heteroatom-free carbon dots (CDs) on the alleviation of abiotic stresses in rice for the first time. During in vitro coincubation, suspended rice cells were exposed to 2,4-dichlorophenoxyacetate sodium (2,4-D-Na, 30 μg mL^-1), 2,4-dichlorophenoxyacetic acid (2,4-D, 5 μg mL^-1), NaCl (0.15 mol·L^-1), and high light (2000 Lux), both with and without CDs (100 μg mL^-1). After a week, CDs significantly reduced the inhibition rate of 2,4-D-Na on the rice cell biomass from 48.16 to 27.44% and increased the biomass of rice cells exposed to 2,4-D, NaCl, and high light, by 4.12, 1.10, and 4.01 times that of the control (pure nutrient medium), respectively. Furthermore, the growth of CD-germinated rice seedlings was not obviously affected by 2,4-D-Na, 2,4-D, and NaCl. Further results showed that the CDs demonstrated an intrinsic free-radical scavenging property and could increase the peroxidase activity and the contents of phenolics and flavonoids in rice by 125.81, 39.60, and 47.63%, respectively. Furthermore, CDs improved the nutrient assimilation of rice cells under 2,4-D stress by 14.69%. With higher antioxidant capacity and sufficient nutrients, the CD-treated rice showed excellent resistance to abiotic stresses. This study suggested the great potential of CDs in protecting crops against abiotic stress.

Direct carbonization of black liquor powders into 3D honeycomb-like porous carbons with a tunable disordered degree for sodium-ion batteries

The 3D honeycomb-like porous carbon with a decreased disordered degree exhibits enhanced rate performance for Na-ion batteries.

Enhancement of Fluorescence Emission for Tricolor Quantum Dots Assembled in Polysiloxane toward Solar Spectrum-Simulated White Light-Emitting Devices

Commercial white light-emitting diodes (LEDs) have the undesirable characteristics of blue-rich emission and low color rendering index (CRI), while the constituent quantum dots (QDs) suffer from aggregation-induced fluorescence quenching and poor stability. Herein, a strategy is developed to assemble tricolor QDs into a polysiloxane matrix using a polymer-mediated hybrid approach whereby the hybrid composite exhibits a significant enhancement of aggregation-dispersed emission, outstanding photostability, high thermal stability, and outstanding fluorescence recovery. Using the as-prepared hybrid fluorescent materials, the fabricated LEDs exhibit solar spectrum-simulated emission with adjustable Commission Internationale de L'Eclairage coordinates, correlated color temperature, and a recorded CRI of 97. Furthermore, they present no ultraviolet emission and weak blue emission, thus indicating an ideal healthy and high-CRI white LED lighting source.

Improved ion-diffusion performance by engineering an ordered mesoporous shell in hollow carbon nanospheres

A new kind of hollow carbon nanosphere with an ordered mesoporous shell structure is prepared and demonstrated to have improved performances in practical application areas involving fast ion transport.

A self-crosslinking procedure to construct yolk–shell Au@microporous carbon nanospheres for lithium–sulfur batteries

An efficient self-crosslinking procedure to reasonably construct porous shells is reported for the synthesis of yolk–shell Au@microporous carbon nanospheres.

Engineering of nanonetwork-structured carbon to enable high-performance potassium-ion storage

Potassium-ion batteries (KIBs) have been developed as an emerging electrochemical energy storage device due to the low cost and abundant resource of potassium. However, they suffer insufficient cyclability and poor rate capability caused by the large K⁺, severely limits their further applications. Herein, a nanonetwork-structured carbon (NNSC) is reported to address the issue. Cycling stability with very low decay rate of 0.004% per cycle over 2000 cycles and excellent rate capability (i.e., 261 mAh g^-1 at 100 mA g^-1 and 108 mAh g^-1 at 5000 mA g^-1) are achieved. The superior performance is attributed to the unique structure of NNSC, in which the three-dimensional interconnected hierarchical porous structure with hollow nanosphere as network units not only can effectively alleviate the volume expansion induced by the insertion of large K⁺, but also can offer fast pathways for K⁺ diffusion. In addition, the local graphitized carbon shell of NNSC can promote conductivity of material and reduce the resistance to K⁺ transportation. Thus, the NNSC has great potential in developing stable-structure and high-rate electrodes for next generation KIBs.

Rational Design and Controllable Synthesis of Multishelled Fe2O3@SnO2@C Nanotubes as Advanced Anode Material for Lithium-/Sodium-Ion Batteries

Hierarchical Fe₂O₃ and SnO₂ nanostructures have shown great potential for applications in high-performance ion batteries because of their superiority, including wide resources, facile preparation, environmental friendliness, and high energy density. However, some severe challenges, such as rapid capacity decay due to volume expansion upon cycling and poor conductivity, limit their rate performance. To address this issue, multishelled Fe₂O₃@SnO₂@C (FSC) nanotubes were designed and synthesized by using a template method and Ostwald interaction. The as-prepared FSC nanotubes can deliver a high capacity of 1659 mA h g^-1 at a current density of 200 mA g^-1 and a high reversible capacity of 818 mA h g^-1 at 2000 mA g^-1 for lithium-ion batteries. Particularly, a high specific capacity of 1024 mA h g^-1 is still maintained after 100 charging/discharging cycles at 200 mA g^-1. Applied in sodium-ion batteries, the multishelled FSC nanotubes manifest a high specific capacity of 449 mA h g^-1 after 180 cycles at 50 mA g^-1. Such excellent performances of the as-fabricated FSC nanotubes may be due to the unique multishelled tubular structure, porous characteristics, and high specific surface area. Therefore, the present work provides an outstanding method to improve the energy storage performance of metal oxide composites and other types of nanocomposites.

The LEPR K109R and Q223R Might Contribute to the Risk of NAFLD: A Meta-Analysis

BACKGROUND

Leptin and insulin resistance have been pointed out to play a role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Increasing genes were shown to be associated with the risk of NAFLD.

OBJECTIVE

The study aimed to investigate the genetic association between two leptin receptor (LEPR) polymorphisms (Q223R and K109R) and the NAFLD risk.

METHODS

Studies were retrieved and included by using PubMed, Web of Science, the Cochrane Library databases, Chinese National Knowledge Infrastructure (CNKI) and EMBASE database. Genetic associations were assessed with pooled odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Five case-control studies with 1711 NAFLD patients and 1732 healthy controls were included in this meta-analysis. The K109R was significantly associated with NAFLD in allelic model in Southeast Asian subgroup (p=0.01, OR=0.59, 95% CI [0.39- 0.90]), but not in Chinese subgroup (p=0.24, OR=1.10, 95% CI [0.94-1.29]). The Q223R was significantly associated with NAFLD in both allelic and recessive models (allelic model: p<0.001, OR=0.57, 95% CI [0.50-0.65]; recessive model: p=0.001, OR=0.67, 95% CI [0.52-0.85]). However, subgroup analysis showed that the significant association between Q223R and NAFLD in allelic model cannot be found in Southeast Asians subgroup (p=0.07, OR=0.67, 95% CI [0.52-0.85]).

CONCLUSION

LEPR K109R might be a susceptible factor for NAFLD in Southeast Asian population. And LEPR Q223R might be a susceptible factor for NAFLD in Chinese population.

Hidden resilience and adaptive dynamics of the global online hate ecology

Online hate and extremist narratives have been linked to abhorrent real-world events, including a current surge in hate crimes^1-6 and an alarming increase in youth suicides that result from social media vitriol⁷; inciting mass shootings such as the 2019 attack in Christchurch, stabbings and bombings^8-11; recruitment of extremists^12-16, including entrapment and sex-trafficking of girls as fighter brides¹⁷; threats against public figures, including the 2019 verbal attack against an anti-Brexit politician, and hybrid (racist-anti-women-anti-immigrant) hate threats against a US member of the British royal family¹⁸; and renewed anti-western hate in the 2019 post-ISIS landscape associated with support for Osama Bin Laden's son and Al Qaeda. Social media platforms seem to be losing the battle against online hate^19,20 and urgently need new insights. Here we show that the key to understanding the resilience of online hate lies in its global network-of-network dynamics. Interconnected hate clusters form global 'hate highways' that-assisted by collective online adaptations-cross social media platforms, sometimes using 'back doors' even after being banned, as well as jumping between countries, continents and languages. Our mathematical model predicts that policing within a single platform (such as Facebook) can make matters worse, and will eventually generate global 'dark pools' in which online hate will flourish. We observe the current hate network rapidly rewiring and self-repairing at the micro level when attacked, in a way that mimics the formation of covalent bonds in chemistry. This understanding enables us to propose a policy matrix that can help to defeat online hate, classified by the preferred (or legally allowed) granularity of the intervention and top-down versus bottom-up nature. We provide quantitative assessments for the effects of each intervention. This policy matrix also offers a tool for tackling a broader class of illicit online behaviours^21,22 such as financial fraud.

Emergent dynamics of extremes in a population driven by common information sources and new social media algorithms

We quantify how and when extreme subpopulations emerge in a model society despite everyone having the same information and available resources – and show that counterintuitively these extremes will likely be enhanced over time by new social media algorithms designed to reduce division. We verify our analysis mathematically, and show it reproduces (a) the time-dependent behavior observed in controlled experiments on humans, (b) the findings of a recent study of online behavior by Facebook concerning the impact of ‘soft’ and ‘hard’ news, (c) the observed temporal emergence of extremes in U.S. House of Representatives voting, and (d) the real-time emergence of a division in national opinion during the ongoing peace process in Colombia. We uncover a novel societal tipping point which is a ‘ghost’ of a nearby saddle-node bifurcation from dynamical systems theory, and which provides a novel policy opportunity for preventing extremes from emerging.

Extraordinary Thickness-Independent Electrochemical Energy Storage Enabled by Cross-Linked Microporous Carbon Nanosheets

Two-dimensional carbon-based nanomaterials have demonstrated great promise as electrode materials for electrochemical energy storage. However, there is a trade-off relationship between energy storage and rate capability for carbon-based energy storage devices because of the incrementing ion diffusion limitations, especially for thick electrodes with high mass loading. Herein, we report the cross-linked microporous carbon nanosheets enabling high-energy and high-rate supercapacitors. The as-fabricated microporous carbon nanosheets exhibit an extraordinary thickness-independent electrochemical performance. With the thickness of 15 μm, the as-fabricated carbon nanosheet electrode possesses areal/volumetric/gravimetric capacitance of 895 mF cm^-2/596 F cm^-3/358 F g^-1. Even at a high electrode thickness of 125 μm, the as-fabricated thick electrode presents an ultrahigh areal/volumetric/gravimetric capacitance of 4102 mF cm^-2/328 F cm^-3/328 F g^-1. Furthermore, the as-assembled symmetric supercapacitor delivers an outstanding energy density of 19.2 W h kg^-1 at a power density of 135 W kg^-1 and ultralong cycling stability (capacitance retention of 95% after 180 000 charge/discharge cycles) in an alkaline electrolyte. This work not only provides a facile method for low-cost preparation of carbon nanostructures and high-value utilization of biomass wastes but also offers new insights into rational design and fabrication of advanced electrode materials for high-performance electrochemical energy storage.