Kagome superconductors with TC up to 7 K have been discovered for over 40 y. Recently, unconventional chiral charge order has been reported in kagome superconductor KV3Sb5, with an ordering ...temperature of one order of magnitude higher than the TC. However, the chirality of the charge order has not been reported in the cousin kagome superconductor CsV3Sb5, and the electronic nature of the chirality remains elusive. In this paper, we report the observation of electronic chiral charge order in CsV3Sb5 via scanning tunneling microscopy (STM). We observe a 2 × 2 charge modulation and a 1 × 4 superlattice in both topographic data and tunneling spectroscopy. 2 × 2 charge modulation is highly anticipated as a charge order by fundamental kagome lattice models at van Hove filling, and is shown to exhibit intrinsic chirality. We find that the 1 × 4 superlattices form various small domain walls, and can be a surface effect as supported by our first-principles calculations. Crucially, we find that the amplitude of the energy gap opened by the charge order exhibits real-space modulations, and features 2 × 2 wave vectors with chirality, highlighting the electronic nature of the chiral charge order. STM study at 0.4 K reveals a superconducting energy gap with a gap size 2 Δ = 0.85 meV , which estimates a moderate superconductivity coupling strength with 2Δ/kBTC = 3.9 . When further applying a c-axis magnetic field, vortex core bound states are observed within this gap, indicative of clean-limit superconductivity.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Immobilizing metal atoms by multiple nitrogen atoms has triggered exceptional catalytic activity toward many critical electrochemical reactions due to their merits of highly unsaturated coordination ...and strong metal-substrate interaction. Herein, atomically dispersed Fe-NC material with precise sulfur modification to Fe periphery (termed as Fe-NSC) was synthesized, X-ray absorption near edge structure analysis confirmed the central Fe atom being stabilized in a specific configuration of Fe(N
)(N-C-S). By enabling precisely localized S doping, the electronic structure of Fe-N
moiety could be mediated, leading to the beneficial adjustment of absorption/desorption properties of reactant/intermediate on Fe center. Density functional theory simulation suggested that more negative charge density would be localized over Fe-N
moiety after S doping, allowing weakened binding capability to *OH intermediates and faster charge transfer from Fe center to O species. Electrochemical measurements revealed that the Fe-NSC sample exhibited significantly enhanced oxygen reduction reaction performance compared to the S-free Fe-NC material (termed as Fe-NC), showing an excellent onset potential of 1.09 V and half-wave potential of 0.92 V in 0.1 M KOH. Our work may enlighten relevant studies regarding to accessing improvement on the catalytic performance of atomically dispersed M-NC materials by managing precisely tuned local environments of M-N
moiety.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Continuous-wave laser operation is demonstrated at room temperature with a new disordered Yb:CLNGG crystal. A maximum output power of 5.05 W is generated with 7.8 W of pump power absorbed in the ...crystal, resulting in an optical-to-optical efficiency of 65%, whereas the slope efficiency is determined to be 92%, approaching the limit imposed by the quantum defect in the laser emission process.
Key message
DgNAC1
,
a transcription factor of chrysanthemum, was functionally verified to confer salt stress responses by regulating stress-responsive genes
.
NAC transcription factors play ...effective roles in resistance to different abiotic stresses, and overexpressions of NAC TFs in
Arabidopsis
have been proved to be conducive in improving salinity tolerance. However, functions of NAC genes in chrysanthemum continue to be poorly understood. Here, we performed physiology and molecular experiments to evaluate roles of
DgNAC1
in chrysanthemum salt stress responses. In this study,
DgNAC1
-overexpressed chrysanthemum was obviously more resistant to salt over the WT (wild type). Specifically, the transgenic chrysanthemum showed a higher survival rate and lower EC (electrolyte conductivity) than WT under salt stress. The transgenic chrysanthemum also showed fewer accumulations of MDA (malondialdehyde) and reactive oxygen species (H
2
O
2
and O
2
−
), greater activities of SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase), as well as more proline content than WT under salt stress. Furthermore, stress-responsive genes in transgenic chrysanthemum were greater up-regulated than in WT under salinity stress. Thus, all results revealed that
DgNAC1
worked as a positive regulator in responses to salt stress and it may be an essential gene for molecular breeding of salt-tolerant plants.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Advanced age is associated with left ventricular (LV) remodeling and impaired diastole. The association among aging, mitral leaflet closure (EF slope), cardiac structures, and diastolic indices in an ...asymptomatic Taiwanese population is largely unknown.
We studied 8103 asymptomatic participants (49.5±11.6years, 38.2% women) from a health evaluation cohort (2004–2012) in a tertiary center in Taiwan. Echo-derived LV structure/function, and M-mode based EF slope (mm/s) and serum NT-proBNP level were obtained. The association between EF slope and the other clinical or echo-based parameters was investigated.
Average values for EF slope among various age groups in the Taiwanese population were determined for both genders. Advanced age was associated with reductions in EF slope (adjusted estimate: −0.35/per decade). Reduced EF slope was associated with older age, higher blood pressure and greater body mass index in multivariate models (all p<0.05). Reduced EF slope was correlated with greater cardiac concentricity, abnormal E′ and E/E′ (AUROC: 0.74 and 0.77, respectively, both p<0.05) and elevated NT-proBNP (Coef: 5.98pg/mL, per −10mm/s EF slope, 95% CI: 7.82 to 4.17, p<0.001). EF-slope also clearly discriminated individuals with abnormal estimated LV filling (E/E′ categorized by <8, ≥8 & <15, ≥15, ANOVA p<0.001).
EF-slope reduction in the asymptomatic Taiwanese population was correlated with age, several unfavorable LV remodeling, and impaired diastolic function parameters, and EF-slope can be an effective clinical diagnostic tool for identifying poor E′ and elevated LV filling pressure. In addition, our data provided reference values for EF-slope in various age groups.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
An Ni/Au Schottky contact on an AlGaN/GaN heterostructure has been prepared. By using the peak-conductance model, the threshold voltage and the series resistance of the AlGaN/GaN diode are ...simultaneously extracted from the conductance-voltage （G-V） curve and found to be in good agreement with the ones obtained by using the capacitance-voltage （C-V） curve integration and the plot of dV/d（ln I） versus current I. Thus, a method of directly and simultaneously extracting both the threshold voltage and the series resistance from the conductance-voltage curve for the AlGaN/GaN Schottky diode is developed.
Aqueous anion recognition using artificial receptors is of great interest but full of challenges. Typically, anion-selective receptors are designed by selecting scaffolds that have either hydrogen ...bonding sites or positively charged moieties. Herein, we constructed an acetate-responsive chromogenic molecular switch with a phenolphthalein backbone and achieved the visual recognition of acetate in pure water. UV–Vis and 1H NMR titration data reveal that the molecular switch receptor has good selectivity and binding towards acetate. Mechanistic studies have shown that this molecular switch-type anion receptor recognizes acetate through hydrogen bonding to facilitate proton transfer. Our findings are expected to pave the way for a new class of aqueous anion receptors and the development of new molecular recognition mechanisms.
A novel phenolphthalein-based molecular switchable anion receptor is capable of highly selective recognition of acetate in water via hydrogen bonding-induced proton transfer mechanisms. Display omitted
•New phenolphthalein-based molecular switched receptors for acetate were designed.•Solvent polarity governs the ratio of colored ring-opening to colorless ring-closed in molecular switch.•Acetate in pure water can be easily recognized with this receptor through the naked eye.•Acetate recognition mechanism involves hydrogen bonding-induced proton transfer.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Human primary fibroblasts are a popular type of somatic cells for the production of induced pluripotent stem (iPS) cells. Here we characterized biological properties of primary fibroblasts in terms ...of cell-growth rate, cytogenetic stability, and the number of inactive X chromosomes during long-term passaging. We produced eight lines of female human dermal fibroblasts (HDFs) and found normal karyotype and expected pattern of X chromosome inactivation (XCI) at low passages (Passage P1-5). However, four out of the eight HDF lines at high passage numbers (≥P10) exhibited duplicated hallmarks of inactive X chromosome including two punctuate signals of histone H3 lysine 27 trimethylation (H3K27me3) and X inactive-specific transcript (XIST) RNA signals in approximately 8.5–18.5% of the cells. Our data suggest that the copy number of inactive X chromosomes in a subset of female HDF is increased by a two-fold. Consistently, DNA fluorescent in situ hybridization (FISH) identified 3-4 copies of X chromosomes in one nucleus in this subset of cells with two inactive Xs. We conclude that female HDF cultures exhibit a higher risk of genetic anomalies such as carrying an increased number of X chromosomes including both active and inactive X chromosomes at a high passage (≥P10).
Full text
Available for:
FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
