An All-Soluble Fe/Mn-Based Alkaline Redox Flow Battery System.

Redox flow batteries (RFBs) are membrane-separated rechargeable flow cells with redox electrolytes, offering the potential for large-scale energy storage and supporting renewable energy grids. Yet, creating a cost-effective, high-performance RFB system is challenging. In this work, we investigate an Fe/Mn RFB alkaline system based on the [(TEA)Fe-O-Fe(TEA)]3-/4- and MnO4-/2- redox couples with a theoretical cell voltage of ∼1.43 V. This combination has not been systematically studied previously, but it can lead to a very low-cost and sustainable materials for high energy storage. Constant current cycling tests were performed at ±41 mA cm-2 between 20% and 80% SOC over 800 h (400 cycles) with an apparent Coulombic efficiency (CE) approaching 100%, while the voltage efficiency (VE) gradually decreased from ∼75.3% to ∼61.4% due to increasing internal resistances. The voltage efficiency loss can be mitigated through a periodic acid treatment to remove MnO2 deposits from the separator.

Stimuli-triggered multilayer films in response to temperature and ionic strength changes for controlled favipiravir drug release.

The block copolymer micelles and natural biopolymers were utilized to form layer-by-layer (LbL) films via electrostatic interaction, which were able to effectively load and controllably release favipiravir, a potential drug for the treatment of coronavirus epidemic. The LbL films demonstrated reversible swelling/shrinking behavior along with the manipulation of temperature, which could also maintain the integrity in the structure and the morphology. Due to dehydration of environmentally responsive building blocks, the drug release rate from the films was decelerated by elevating environmental temperature and ionic strength. In addition, the pulsed release of favipiravir was observed from the multilayer films under the trigger of temperature, which ensured the precise control in the content of the therapeutic reagents at a desired time point. The nanoparticle-based LbL films could be used for on-demandin vitrorelease of chemotherapeutic reagents.

A novel telomere-related genes model for predicting prognosis and treatment responsiveness in diffuse large B-cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is a highly heterogeneous disease with diverse clinical and molecular features. Telomere maintenance is widely present in tumors, but there is a lack of relevant reports on the role of telomere-related genes (TRGs) in DLBCL. In this study, we used consensus clustering based on TRGs expression to identify two molecular clusters with distinct prognoses and immune cell infiltration. We developed a TRGs scoring model using univariate Cox regression and LASSO regression in the GSE10846 training cohort. DLBCL patients in the high-risk group had a worse prognosis than those in the low-risk group, as revealed by Kaplan-Meier curves. The scoring model was validated in the GSE10846 testing cohort and GSE87371 cohort, respectively. The high-risk group was characterized by elevated infiltration of activated DCs, CD56 dim natural killer cells, myeloid-derived suppressor cells, monocytes, and plasmacytoid DCs, along with reduced infiltration of activated CD4 T cells, Type 2 T helper cells, γδ T cells, NK cells, and neutrophils. Overexpression of immune checkpoints, such as PDCD1, CD274, and LAG3, was observed in the high-risk group. Furthermore, high-risk DLBCL patients exhibited increased sensitivity to bortezomib, rapamycin, AZD6244, and BMS.536924, while low-risk DLBCL patients showed sensitivity to cisplatin and ABT.263. Using RT-qPCR, we found that three protective model genes, namely TCEAL7, EPHA4, and ELOVL4, were down-regulated in DLBCL tissues compared with control tissues. In conclusion, our novel TRGs-based model has great predictive value for the prognosis of DLBCL patients and provides a promising direction for treatment optimization.

A novel angiogenesis-related scoring model predicts prognosis risk and treatment responsiveness in diffuse large B-cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is a highly heterogeneous disease with varying therapeutic responses and prognoses. Angiogenesis is a crucial factor in lymphoma growth and progression, but no scoring model based on angiogenesis-related genes (ARGs) has been developed for prognostic evaluation of DLBCL patients. In this study, we used univariate Cox regression to identify prognostic ARGs and found two distinct clusters of DLBCL patients in the GSE10846 dataset based on the expression of these prognostic ARGs. These two clusters had different prognoses and immune cell infiltration. Using LASSO regression analysis, we constructed a novel seven-ARG-based scoring model in GSE10846 dataset, and it was further validated in the GSE87371 dataset. The DLBCL patients were divided into high- and low-score groups based on the median risk score as a cut-off. The high-score group had a worse prognosis and showed higher expression of immune checkpoints, M2 macrophages, myeloid-derived suppressor cells, and regulatory T cells, indicating a stronger immunosuppressive environment. DLBCL patients in high-score group were resistant to doxorubicin and cisplatin, which are components of frequently used chemotherapy regimens, but more sensitive to gemcitabine and temozolomide. Using RT-qPCR, we found that two candidate risk genes, RAPGEF2 and PTGER2, were over-expressed in DLBCL tissues compared with control tissues. Taken together, the ARG-based scoring model provides a promising direction for the prognosis and immune status of DLBCL patients, and benefits the development of personalized treatment for DLBCL patients.

A Novel Swarm Intelligence Algorithm with a Parasitism-Relation-Based Structure for Mobile Robot Path Planning.

A multi-swarm-evolutionary structure based on the parasitic relationship in the biosphere is proposed in this paper and, according to the conception, the Para-PSO-ABC algorithm (ParaPA), combined with merits of the modified particle swarm optimization (MPSO) and artificial bee colony algorithm (ABC), is conducted with the multimodal routing strategy to enhance the safety and the cost issue for the mobile robot path planning problem. The evolution is divided into three stages, where the first is the independent evolutionary stage, with the same evolution strategies for each swarm. The second is the fusion stage, in which individuals are evolved hierarchically in the parasitism structure. Finally, in the interaction stage, a multi-swarm-elite strategy is used to filter the information through a predefined cross function among swarms. Meanwhile, the segment obstacle-avoiding strategy is proposed to accelerate the searching speed with two fitness functions. The best path is selected according to the performance on the safety and consumption issues. The introduced algorithm is examined with different obstacle allocations and simulated in the real routing environment compared with some typical algorithms. The results verify the productiveness of the parasitism-relation-based structure and the stage-based evolution strategy in path planning.

Dzyaloshinskii-Moriya-Interaction-Like Behavior in Confined Permalloy Nanostructures via Coupled Magnetic Vortices.

Dzyaloshinskii-Moriya interaction (DMI), one of antisymmetric exchanges, originates from the combination of low structural symmetry and large spin-orbit coupling and favors magnetization rotations with fixed chirality. Herein, this work reports a DMI-like behavior in permalloy via coupled vortices in confined structures. Under the in-plane magnetic fields, continuous reversals of different coupled vortices are directly observed by in situ Lorentz transmission electron microscopy, and reproduced by complementary micromagnetic simulations. The statistical results show that coupled vortices with opposite chirality appear more frequently with the frequency up to about 60%. Such an asymmetric phenomenon mainly arises from a DMI-like behavior, associated with the increased total energy difference between different ground-state coupled vortices. Moreover, in the reversal process, the junction between disks accelerates the annihilation of vortices moving toward it and is also the starting point of vortex nucleation. These results provide an effective method to generate a DMI-like behavior in magnetic systems with symmetry breaking surface and benefit the future development of vortex-based spintronic devices.

Redox-Active Eutectic Electrolyte with Viologen and Ferrocene Derivatives for Flow Batteries.

Nonflammable eutectic solvents show great potential to enhance the concentrations of the redox-active materials and the cell voltages for redox flow batteries (RFBs). Herein, we report a promising redox-active eutectic electrolyte (1.5 M total redox species) with viologen and ferrocene derivatives where both of the redox reactions are reversible with a maximum open-circuit voltage of 1.35 V and an energy density of 15.1 Wh L-1, which is relevant to large-scale energy storage. The charge-discharge (from 75 to 25% state of charge) characteristics in a flow cell (0.15 M negolyte and 0.3 M posolyte) showed that it can be cycled with consistent discharge capacity for 12 h (19 cycles), beyond which pressure-driven crossover between the posolyte and negolyte reservoirs leads to capacity decay. This study points to promising new directions toward eutectic electrolyte development for RFBs where we demonstrate increasing the polarity, functionalizing the redox molecules, and separating redox intermediates to prevent undesired side reactions can make improvements in operating cell voltage, energy density, and cyclability.

Steric Effects in the Deposition Mode and Drug-Delivering Efficiency of Nanocapsule-Based Multilayer Films.

Using surface-initiated atom transfer radical polymerization (ATRP), block polymers with a series of quaternization degrees were coated on the surface of silica nanocapsules (SNCs) by the "grafting-from" technique. Molnupiravir, an antiviral medicine urgently approved for the treatment of SARS-CoV-2, was encapsulated in polymer-coated SNCs and further incorporated into well-defined films with polystyrene sulfonate (PSS) homopolymers by layer-by-layer (LBL) self-assembly via electrostatic interactions. We investigated the impact of the quaternization degree of the polymers and steric hindrance of functional groups on the growth mode, swelling/deswelling transition, and drug-delivering efficiency of the obtained LBL films. The SNCs were derived from coronas of parent block polymers of matched molecular weights-poly(N-isopropylacrylamide)-block-poly(N,N-dimethylaminoethyl methacrylate) (PNIPAM-b-PDMAEMA)-by quaternization with methyl sulfate. As revealed by the data results, SNCs with coronas with higher quaternization degrees resulted in a larger layering distance of the film structure because of weaker ionic pairing (due to the presence of a bulky methyl spacer) between SNCs and PSS. Interestingly, when comparing the drug release profile of the encapsulated drugs from SNC-based films, the release rate was slower in the case of capsule coronas with higher quaternization degrees because of the larger diffusion distance of the encapsulated drugs and stronger hydrophobic-hydrophobic interactions between SNCs and drug molecules.

Gut microbiota dysbiosis associated with plasma levels of Interferon-γ and viral load in patients with acute hepatitis E infection.

Few studies have focused on the effect of hepatitis E virus (HEV) infection on gut microbiota. To explore the relationship between changes in gut microbiota and inflammatory factors and viral load, we conducted a comparative study of 33 patients with acute hepatitis E (AHE) patients and 25 healthy controls (HCs) using high-throughput 16S ribosomal ribonucleic acid gene sequencing. Shannon and Simpson's indices showed no significant differences in bacterial diversity between the AHE and HCs groups. Proteobacteria, Gammaproteobacteria, and Enterobacteriaceae were most abundant in the AHE group, which contributed to the difference between the gut microbiota of the AHE and HCs groups, and the same difference between the HEV-RNA-positive and HEV-RNA-negative groups. Functional prediction analysis showed that ribosome, purine metabolism, and two-component system were the top three pathways. Compared with the AHE group with normal interferon (IFN)-γ, Proteobacteria, Gammaproteobacteria, Xanthomonadaceae, and Enterobacteriaceae were more abundant in the high-IFN-γ group. The abundance of Gammaproteobacteria was positively correlated with the level of serum alanine transaminase and total bilirubin. The abundance of Gammaproteobacteria could discriminate AHE patients from HCs, and could better predict the severity of AHE patients. We believe that our findings will contribute toward a novel treatment strategy for AHE.

Fingerprinting the Ammonia Synthesis Pathway Using Spatiotemporal Electrostatic Potential Distribution of Intermediates.

It remains a research challenge in determining the catalytic reaction mechanisms primarily caused by the difficulty to experimentally identify active intermediates with current analytic characterizations. Although computational chemistry has provided an alternative approach to simulate the catalysis process and achieve insights into the reaction pathways, the simulation results would not be conclusive without experimental evidence. Herein, we investigate spatiotemporal electrostatic potential (ESP) distribution surrounding reacting molecules during the catalysis process and suggest its use as a fingerprint to help differentiate and identify active intermediates. Our ESP study of ammonia synthesis on the Ru surface shows a high spatial sensitivity of ESP distribution to molecular configuration and structure of intermediate species and only minor temporal ESP oscillation throughout the lifetime of the intermediates, which provides strong theoretical support to use ESP distribution as a new approach to characterize intermediates. With the ESP measurements at the microscale and in real-time, turning feasible, experimental identification of active intermediates and determination of reaction pathways would become possible by measuring the ESP surrounding the reacting molecules. We suggest developing ESP measurement tools to experimentally explore and unveil reaction mechanisms.

Two-Dimensional Metal Organic Framework Nanosheets as Bifunctional Catalyst for Electrochemical and Photoelectrochemical Water Oxidation.

Electrochemical (EC) and photoelectrochemical (PEC) water splitting represent promising strategies for renewable energy conversion and fuel production and require design of efficient catalysts for the oxygen evolution reaction (OER). Herein, we report the synthesis of two-dimensional (2D) Co-based metal organic framework (Co-MOF) nanosheets and their bifunctional catalytic properties for both EC and PEC OER. Benefiting from the large surface area and abundant isolated metal active sites, the Co-MOF nanosheets exhibited excellent OER activity and stability. The efficient electron-hole generation and separation of the nanosheets, owing to dimensional confinement, contributed to an improved visible light response in PEC OER. This study presents a new strategy to design EC/PEC bifunctional catalyst utilizing unique structural and electronic features of 2D MOF.

Preliminary study on discrimination of transgenic cotton seeds using terahertz time-domain spectroscopy.

Presence of genetically modified (GM) organisms is considered to be controversial by legislation and public. It is very important to develop detection methods for early discriminations. Conventional gene detection methods, including protein detection (PCR, ELISA, and so on) and DNA detection (Southern blot, GC/MS, and so on), have the disadvantages of high costs, time-consuming, complex operations, and destructive of the samples. Terahertz spectroscopy (THz) is a brand-new radiation with many unique advantages. Most biological macromolecules have fingerprint characteristics in THz band from the current recognition. In this study, feasibility of identifying the transgenic cotton seeds from nontransgenic counterparts using THz spectroscopy method was investigated. The transgenic cotton seeds-Lumianyan No.28 and nontransgenic cotton seeds-Xinluzao No.51 were selected and the sample-making methods were studied; then the refractive and absorption curves of samples were got and given a detailed discussion; finally, absorption index of transgenic and nontransgenic DNA was observed and discussed. The results showed there were small fluctuations in THz band, and refractive index of transgenic seeds was lower than nontransgenic ones and had obvious turning point at 1.4-2.0 THz region. There were significant peaks in 1.0-1.2 and 1.3-1.5 THz regions for the transgenic cotton seeds. Transgenic DNA had higher absorption index than nontransgenic DNA, and there were 3-4 peaks corresponding to the cotton seed samples in 1.0-1.6 THz region. These results showed cotton seeds samples can provide important bio-information in THz band, and this study provided a basis for developing potential THz-based gene detection technologies.

Very-Low-Frequency transmitters bifurcate energetic electron belt in near-earth space.

Very-Low-Frequency (VLF) transmitters operate worldwide mostly at frequencies of 10-30 kilohertz for submarine communications. While it has been of intense scientific interest and practical importance to understand whether VLF transmitters can affect the natural environment of charged energetic particles, for decades there remained little direct observational evidence that revealed the effects of these VLF transmitters in geospace. Here we report a radially bifurcated electron belt formation at energies of tens of kiloelectron volts (keV) at altitudes of ~0.8-1.5 Earth radii on timescales over 10 days. Using Fokker-Planck diffusion simulations, we provide quantitative evidence that VLF transmitter emissions that leak from the Earth-ionosphere waveguide are primarily responsible for bifurcating the energetic electron belt, which typically exhibits a single-peak radial structure in near-Earth space. Since energetic electrons pose a potential danger to satellite operations, our findings demonstrate the feasibility of mitigation of natural particle radiation environment.

A vacuum impregnation method for synthesizing octahedral Pt2CuNi nanoparticles on mesoporous carbon support and the oxygen reduction reaction electrocatalytic properties.

Mesoporous carbon (MPC) nanomaterials, with large specific surface area, excellent conductivity and stability, and effective mass transfer are beneficial for use as catalyst support in electrochemical oxygen reduction reaction (ORR) for fuel cell applications. However, MPC utilization was limited by difficulties in loading catalyst nanoparticles within the MPC pores while simultaneously controlling critical particle parameters such as size and distribution. In this study we report a new vacuum impregnation method combined with solid-state chemistry synthesis for preparing highly active ORR catalyst nanoparticles on MPC supports. We confirm the effectiveness of this method by synthesizing octahedral Pt2CuNi nanoparticles on hydrophilic MPC with an even particle distribution in the MPC pores. We also demonstrate the capability of this method in controlling the particle size and morphology by adjusting the synthesis parameters. The synthesized catalysts exhibited excellent ORR activity and promising durability, which proves the goodness of using MPC support in ORR electrocatalysis. The findings offer a new methodology for synthesizing nanoparticles in MPC pores with parameter control and provide an intriguing strategy to develop new ORR catalysts using MPC support structure.

Origin of two-band chorus in the radiation belt of Earth.

Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA's Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres.

Seroprevalence and molecular characteristics of varicella-zoster virus infection in Chinese children.

BACKGROUND: Varicella-zoster virus (VZV) infection in children is an important public health problem in China. We performed the current study to explore the seroprevalence of VZV infection in Chinese children in order to provide more information for improvement of varicella vaccination in China. METHODS: Three thousand fourteen children were recruited from Chinese kindergarten students aged from four to six years. Anti-VZV IgG and IgM were assayed using enzyme-linked immunosorbent assay. Both ORF22 and ORF62 of VZV were amplified, sequenced, and analyzed by nested PCR. RESULTS: Among 3014 children, 43.9% of boys and 46.3% of girls were vaccinated with varicella vaccine, respectively. The seroprevalence of anti-VZV IgG was 54.4% in the children with varicella vaccination, which was significantly higher than those in unvaccinated children (49.2%) (χ2 = 8.206, P = 0.004). Among of the vaccinated children, the detection rates of VZV IgG antibody increased with age, with 49.4, 50.9 and 58.9% in 4, 5 and 6-year groups, respectively (Trend χ2 = 17.202, P = 0.002). However, there was no difference in anti-VZV IgG detection rates among those unvaccinated children in different age groups (Trend χ2 = 8.681, P = 0.070). In addition, 13 boys and 13 girls were positive for anti-VZV IgM, respectively. Among of them, eight children (0.6%) have received varicella vaccination, which was similar to those in unvaccinated children (1.1%). However, only one ORF22 sequence was isolated from an unvaccinated 5-year boy. Compared to the reference VZV sequences, the nucleotide homology was estimated to be 99.7% with genotype J. CONCLUSIONS: Our study indicated that about half of Chinese children aged four to six years have a high risk of VZV infection. It should be helpful for the evaluation on the necessity of varicella immunization in China.

Designing Highly Efficient and Long-Term Durable Electrocatalyst for Oxygen Evolution by Coupling B and P into Amorphous Porous NiFe-Based Material.

Oxygen evolution reaction (OER) is of great significance for hydrogen production via water electrolysis, which, however, demands development of highly active, durable, and cost-effective electrocatalysts in order to stride into a renewable energy era. Herein, highly efficient and long-term durable OER by coupling B and P into an amorphous porous NiFe-based electrocatalyst is reported, which possesses an amorphous porous metallic bulk structure and high corrosion resistance, and overcomes the issues associated with currently used catalyst nanomaterials. The PB codoping in the activated NiFePB (a-NiFePB) delocalizes both Fe and Ni at Fermi energy level and enhances p-d hybridization as simulated by density functional theory calculations. The harmonized electronic structure and unique porous framework of the a-NiFePB consequently improve the OER activity. The activated NiFePB thus exhibits an extraordinarily low overpotential of 197 mV for harvesting 10 mA cm-2 OER current density and 233 mV for reaching 100 mA cm-2 under chronopotentiometry condition, with the Tafel slope harmoniously conforming to 34 mV dec-1 . Impressive long-term stability of this new catalyst is evidenced by only limited activity decay after 1400 h operation at 100 mA cm-2 . This work strategically directs a way for heading up a promising energy conversion alternative.

Dual-Site Cascade Oxygen Reduction Mechanism on SnO x/Pt-Cu-Ni for Promoting Reaction Kinetics.

Designing highly active oxygen reduction reaction (ORR) catalysts is crucial to boost the fuel cell economy. Previous research has mainly focused on Pt-based alloy catalysts in which surface Pt is the solely active site and the activity improvement was challenged by the discovered scaling relationship. Herein we report a new concept of utilizing dual active sites for the ORR and demonstrate its effectiveness by synthesizing a SnO x/Pt-Cu-Ni heterojunctioned catalyst. A maximum of 40% enhancement in the apparent specific activity, which corresponds to 10-fold enhancement on interface sites, is measured compared with pure Pt-Cu-Ni. Detailed investigations suggest an altered dual-site cascade mechanism wherein the first two steps occur on SnO x sites and the remaining steps occur on adjacent Pt sites, allowing a significant decrease in the energy barrier. This study with the suggested dual-site cascade mechanism shows the potential to overcome the ORR energy barrier bottleneck to develop highly active catalysts.

Deconvolution of octahedral Pt3Ni nanoparticle growth pathway from in situ characterizations.

Understanding the growth pathway of faceted alloy nanoparticles at the atomic level is crucial to morphology control and property tuning. Yet, it remains a challenge due to complexity of the growth process and technical limits of modern characterization tools. We report a combinational use of multiple cutting-edge in situ techniques to study the growth process of octahedral Pt3Ni nanoparticles, which reveal the particle growth and facet formation mechanisms. Our studies confirm the formation of octahedral Pt3Ni initiates from Pt nuclei generation, which is followed by continuous Pt reduction that simultaneously catalyzes Ni reduction, resulting in mixed alloy formation with moderate elemental segregation. Carbon monoxide molecules serve as a facet formation modulator and induce Ni segregation to the surface, which inhibits the (111) facet growth and causes the particle shape to evolve from a spherical cluster to an octahedron as the (001) facet continues to grow.

High-Performance Transition Metal Phosphide Alloy Catalyst for Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) is a pivotal process in many energy conversion and storage techniques, such as water splitting, regenerative fuel cells, and rechargeable metal-air batteries. The synthesis of stable, efficient, non-noble metal-based electrocatalysts for OER has been a long-standing challenge. In this work, a facile and scalable method to synthesize hollow and conductive iron-cobalt phosphide (Fe-Co-P) alloy nanostructures using an Fe-Co metal organic complex as a precursor is described. The Fe-Co-P alloy exhibits excellent OER activity with a specific current density of 10 mA/cm2 being achieved at an overpotential as low as 252 mV. The current density at 1.5 V (vs reversible hydrogen electrode) of the Fe-Co-P catalyst is 30.7 mA/cm2, which is more than 3 orders of magnitude greater than that obtained with state-of-the-art Fe-Co oxide catalysts. Our mechanistic experiments and theoretical analysis suggest that the electrochemical-induced high-valent iron stabilizes the cobalt in a low-valent state, leading to the simultaneous enhancement of activity and stability of the OER catalyst.