Developing nonprecious oxygen evolution electrocatalysts that can work well at large current densities is of primary importance in a viable water‐splitting technology. Herein, a facile ultrafast (5 ...s) synthetic approach is reported that produces a novel, efficient, non‐noble metal oxygen‐evolution nano‐electrocatalyst that is composed of amorphous Ni–Fe bimetallic hydroxide film‐coated, nickel foam (NF)‐supported, Ni3S2 nanosheet arrays. The composite nanomaterial (denoted as Ni‐Fe‐OH@Ni3S2/NF) shows highly efficient electrocatalytic activity toward oxygen evolution reaction (OER) at large current densities, even in the order of 1000 mA cm−2. Ni‐Fe‐OH@Ni3S2/NF also gives an excellent catalytic stability toward OER both in 1 m KOH solution and in 30 wt% KOH solution. Further experimental results indicate that the effective integration of high catalytic reactivity, high structural stability, and high electronic conductivity into a single material system makes Ni‐Fe‐OH@Ni3S2/NF a remarkable catalytic ability for OER at large current densities.
An ultrafast (5 s) synthetic approach that produces a novel, nonprecious oxygen‐evolution electrocatalyst comprising a 3D hierarchical core@shell Ni‐Fe‐OH@Ni3S2 nanostructure supported on nickel foam is presented. The material integrates the structural and catalytic advantages of amorphous Ni–Fe–OH and Ni3S2 nanosheet arrays, possessing an excellent ability to efficiently and stably electrocatalyze the oxygen evolution reaction at large current densities.
Chlorine disinfection to drinking water plays an important role in preventing and controlling waterborne disease outbreaks globally. Nevertheless, little is known about why it enriches the antibiotic ...resistance genes (ARGs) in bacteria after chlorination. Here, ARGs released from killed antibiotic-resistant bacteria (ARB), and culturable chlorine-injured bacteria produced in the chlorination process as the recipient, were investigated to determine their contribution to the horizontal transfer of ARGs during disinfection treatment. We discovered Escherichia coli, Salmonella aberdeen, Pseudomonas aeruginosa and Enterococcus faecalis showed diverse resistance to sodium hypochlorite, and transferable RP4 could be released from killed sensitive donor consistently. Meanwhile, the survival of chlorine-tolerant injured bacteria with enhanced cell membrane permeabilisation and a strong oxidative stress-response demonstrated that a physiologically competent cell could be transferred by RP4 with an improved transformation frequency of up to 550 times compared with the corresponding untreated bacteria. Furthermore, the water quality factors involving chemical oxygen demand (COD
), ammonium nitrogen and metal ions (Ca
and K
) could significantly promote above transformation frequency of released RP4 into injured E. faecalis. Our findings demonstrated that the chlorination process promoted the horizontal transfer of plasmids by natural transformation, which resulted in the exchange of ARGs across bacterial genera and the emergence of new ARB, as well as the transfer of chlorine-injured opportunistic pathogen from non-ARB to ARB. Considering that the transfer elements were quite resistant to degradation through disinfection, this situation poses a potential risk to public health.
Unprecedented measures have been adopted to control the rapid spread of the ongoing COVID-19 epidemic in China. People's adherence to control measures is affected by their knowledge, attitudes, and ...practices (KAP) towards COVID-19. In this study, we investigated Chinese residents' KAP towards COVID-19 during the rapid rise period of the outbreak. An online sample of Chinese residents was successfully recruited via the authors' networks with residents and popular media in Hubei, China. A self-developed online KAP questionnaire was completed by the participants. The knowledge questionnaire consisted of 12 questions regarding the clinical characteristics and prevention of COVID-19. Assessments on residents' attitudes and practices towards COVID-19 included questions on confidence in winning the battle against COVID-19 and wearing masks when going out in recent days. Among the survey completers (n=6910), 65.7% were women, 63.5% held a bachelor degree or above, and 56.2% engaged in mental labor. The overall correct rate of the knowledge questionnaire was 90%. The majority of the respondents (97.1%) had confidence that China can win the battle against COVID-19. Nearly all of the participants (98.0%) wore masks when going out in recent days. In multiple logistic regression analyses, the COVID-19 knowledge score (OR: 0.75-0.90, P<0.001) was significantly associated with a lower likelihood of negative attitudes and preventive practices towards COVID-2019. Most Chinese residents of a relatively high socioeconomic status, in particular women, are knowledgeable about COVID-19, hold optimistic attitudes, and have appropriate practices towards COVID-19. Health education programs aimed at improving COVID-19 knowledge are helpful for Chinese residents to hold optimistic attitudes and maintain appropriate practices. Due to the limited sample representativeness, we must be cautious when generalizing these findings to populations of a low socioeconomic status.
Stimuli‐responsive circularly polarized luminescence (CPL) materials are ideal for information anti‐countering applications, but the best‐performing materials have not yet been identified. This work ...presents enantiomorphic hybrid antimony halides R‐(C5H12NO)2SbCl5 (1) and S‐(C5H12NO)2SbCl5 (2) showing mirror‐imaged CPL activity with a dissymmetry factor of 1.2×10−3. Interestingly, the DMF‐induced structural transformation is realized to obtain non‐emissive R‐(C5H12NO)2SbCl5 ⋅ DMF (3) and S‐(C5H12NO)2SbCl5 ⋅ DMF (4) upon exposure to DMF vapor. The transformation process is reversed upon heating. DFT calculations showed that the DMF‐induced‐quenched‐luminescence is attributed to the intersection of the ground and excited state curves on the configuration coordinates. Unexpectedly, the nanocrystals of the chiral antimony halides 1 and 2 were prepared and indicate the excellent solution process performance. The reversible PL and CPL switching gives the system applications in information technology, anti‐counterfeiting, encryption‐decryption, and logic gates.
The chiral hybrid antimony halides R‐/S‐(C5H12NO)2SbCl5 have excitation‐dependent emission originating from the synergistic effects of ligand and self‐trapped excitons, and exhibit reversible structural transformation between non‐emissive R‐/S‐(C5H12NO)2SbCl5 ⋅ DMF upon exposure to DMF and heat. CPL switch, chiral optical logic gate and anti‐counterfeiting applications have been investigated based on the multiple stimuli‐responsive properties.
Hitherto, developing an economical and stable high-activity bifunctional Pt catalyst for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) becomes necessary for fuel cells and ...regeneration fuel cell system. However, how to uniformly disperse and firmly fix Pt nanoparticles (NPs) on carbon support with optimal particle size for catalysis is still a big challenge. Herein, by taking advantage of the isolating effect of the cobalt (Co) single atom site to Pt, strong interaction between Co single atoms and Pt, and the confinement of the porous carbon matrix derived metal organic frameworks, we successfully evenly immobilize Pt NPs on ZnCo-ZIF originated porous nitrogen-doped carbon matrix with rich cobalt single atoms (Co SAs-ZIF-NC) as multiple active sites. Compared with the commercial Pt/C catalyst, Pt@Co SAs-ZIF-NC, with ultralow Pt loading and ideal particle size, not only increases the active center, but also promotes the catalysis kinetics, greatly improving the ORR and HER catalytic activity. Under acidic conditions, its half-wave potential (0.917 V) is superior to commercial Pt/C (0.868 V), and the mass activity (0.48 A per mgPt) at 0.9 V is 3 times that of Pt/C (0.16 A per mgPt), surpassing the U.S. DOE target of 0.44 A per mgPt. Besides, it also shows outstanding HER performance. At 20 and 30 mV, its mass activity is even 4.5 and 13.6 times that of Pt/C. When further employed for HER in seawater, its mass activity is about 4 times as high as that of Pt/C, demonstrating the great potential applications.
By using Co single atom sites in Co SAs-ZIF-NC to isolate Pt, the obtained Pt@Co SAs-ZIF-NC catalyst, with uniform and highly dispersed Pt nanoparticles on porous Co SAs-ZIF-NC, presents highly efficient and stable dual-function catalysis toward oxygen reduction and hydrogen evolution reactions. Display omitted
•Single Co atom sites in Co SAs-ZIF-NC can isolate Pt and own strong interaction with Pt.•Obvious synergistic effect exists between Co single atom sites and Pt NPs in Pt@Co SAs-ZIF-NC catalysts.•With uniform and highly dispersed Pt NPs, Pt@Co SAs-ZIF-NC exhibits greatly enhanced ORR performance in acidic media.•In acidic media and seawater, high HER performance beyond commercial Pt catalysts is also obtained for the catalyst.•It provides a promising method for designing and constructing highly active and stable ultralow Pt-loaded catalysts.
The maternal-to-zygotic transition (MZT) is a conserved and fundamental process during which the maternal environment is converted to an environment of embryonic-driven development through dramatic ...reprogramming. However, how maternally supplied transcripts are dynamically regulated during MZT remains largely unknown. Herein, through genome-wide profiling of RNA 5-methylcytosine (m5C) modification in zebrafish early embryos, we found that m5C-modified maternal mRNAs display higher stability than non-m5C-modified mRNAs during MZT. We discovered that Y-box binding protein 1 (Ybx1) preferentially recognizes m5C-modified mRNAs through π-π interactions with a key residue, Trp45, in Ybx1’s cold shock domain (CSD), which plays essential roles in maternal mRNA stability and early embryogenesis of zebrafish. Together with the mRNA stabilizer Pabpc1a, Ybx1 promotes the stability of its target mRNAs in an m5C-dependent manner. Our study demonstrates an unexpected mechanism of RNA m5C-regulated maternal mRNA stabilization during zebrafish MZT, highlighting the critical role of m5C mRNA modification in early development.
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•RNA-BisSeq revealed a dynamic RNA m5C landscape during zebrafish embryogenesis•Ybx1 preferentially recognizes m5C-modified mRNAs•Ybx1 deficiency leads to early gastrulation defects in zebrafish embryos•Ybx1 and Pabpc1a coordinately regulate m5C-modified maternal mRNA stability
RNA modifications exert important effects in many critical physiological processes. Using RNA-BisSeq, Yang et al. provide a comprehensive view of the RNA m5C landscape in zebrafish early embryos and show that m5C-modified maternal mRNAs are stabilized by Ybx1 and Pabpc1a during zebrafish MZT.
STEAP3 (Six-transmembrane epithelial antigen of the prostate 3, TSAP6, dudulin-2) has been reported to be involved in tumor progression in human malignancies. Nevertheless, how it participates in the ...progression of human cancers, especially HCC, is still unknown. In the present study, we found that STEAP3 was aberrantly overexpressed in the nuclei of HCC cells. In a large cohort of clinical HCC tissues, high expression level of nuclear STEAP3 was positively associated with tumor differentiation and poor prognosis (p < 0.001), and it was an independent prognostic factor for HCC patients. In HCC cell lines, nuclear expression of STEAP3 significantly promoted HCC cells proliferation by promoting stemness phenotype and cell cycle progression via RAC1-ERK-STAT3 and RAC1-JNK-STAT6 signaling axes. Through upregulating the expression and nuclear trafficking of EGFR, STEAP3 participated in regulating EGFR-mediated STAT3 transactivity in a manner of positive feedback. In summary, our findings support that nuclear expression of STEAP3 plays a critical oncogenic role in the progression of HCC via modulation on EGFR and intracellular signaling, and it could be a candidate for prognostic marker and therapeutic target in HCC.
Copper (II) phthalocyanines (CuPcs) have attracted growing interest as promising hole‐transporting materials (HTMs) in perovskite solar cells (PSCs) due to their low‐cost and excellent stability. ...However, the most efficient PSCs using CuPc‐based HTMs reported thus far still rely on hygroscopic p‐type dopants, which notoriously deteriorate device stability. Herein, two new CuPc derivatives are designed, namely CuPc‐Bu and CuPc‐OBu, by molecular engineering of the non‐peripheral substituents of the Pc rings, and applied as dopant‐free HTMs in PSCs. Remarkably, a small structural change from butyl groups to butoxy groups in the substituents of the Pc rings significantly influences the molecular ordering and effectively improves the hole mobility and solar cell performance. As a consequence, PSCs based on dopant‐free CuPc‐OBu as HTMs deliver an impressive power conversion efficiency (PCE) of up to 17.6% under one sun illumination, which is considerably higher than that of devices with CuPc‐Bu (14.3%). Moreover, PSCs containing dopant‐free CuPc‐OBu HTMs show a markedly improved ambient stability when stored without encapsulation under ambient conditions with a relative humidity of 85% compared to devices containing doped Spiro‐OMeTAD. This work thus provides a fundamental strategy for the future design of cost‐effective and stable HTMs for PSCs and other optoelectronic devices.
Two new copper (II) phthalocyanine (CuPc) derivatives, namely CuPc‐Bu and CuPc‐OBu, are designed by molecular engineering of the non‐peripheral substituents of the Pc rings, and are further explored as dopant‐free hole‐transporting materials (HTMs) in perovskite solar cells (PSCs). The PSCs based on pristine CuPc‐OBu as HTMs afford a maximum power conversion efficiency of 17.6%, which is considerably higher than that of the devices with CuPc‐Bu (14.3%).
We construct a holographic SU(2) p-wave superconductor model with Weyl corrections. The high derivative (HD) terms do not seem to spoil the generation of the p-wave superconducting phase. We mainly ...study the properties of AC conductivity, which is absent in holographic SU(2) p-wave superconductor with Weyl corrections. The conductivities in superconducting phase exhibit obvious anisotropic behaviors. Along
y
direction, the conductivity
σ
yy
is similar to that of holographic s-wave superconductor. The superconducting energy gap exhibits a wide extension. For the conductivity
σ
xx
along
x
direction, the behaviors of the real part in the normal state are closely similar to that of
σ
yy
. However, the anisotropy of the conductivity obviously shows up in the superconducting phase. A Drude-like peak at low frequency emerges in
R
e
σ
xx
once the system enters into the superconducting phase, regardless of the behaviors in normal state.
Operation speed and coherence time are two core measures for the viability of a qubit. Strong spin-orbit interaction (SOI) and relatively weak hyperfine interaction make holes in germanium (Ge) ...intriguing candidates for spin qubits with rapid, all-electrical coherent control. Here we report ultrafast single-spin manipulation in a hole-based double quantum dot in a germanium hut wire (GHW). Mediated by the strong SOI, a Rabi frequency exceeding 540 MHz is observed at a magnetic field of 100 mT, setting a record for ultrafast spin qubit control in semiconductor systems. We demonstrate that the strong SOI of heavy holes (HHs) in our GHW, characterized by a very short spin-orbit length of 1.5 nm, enables the rapid gate operations we accomplish. Our results demonstrate the potential of ultrafast coherent control of hole spin qubits to meet the requirement of DiVincenzo's criteria for a scalable quantum information processor.
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