Electrically Induced Crystal Field Distortion in a Ferroelectric Perovskite Revealed by Electron Paramagnetic Resonance.

The magnetoelectric material has attracted multidisciplinary interest in the past decade for its potential to accommodate various functions. Especially, the external electric field can drive the quantum behaviors of such materials via the spin-electric coupling effect, with the advantages of high spatial resolution and low energy cost. In this work, the spin-electric coupling effect of Mn2+-doped ferroelectric organic-inorganic hybrid perovskite [(CH3)3NCH2Cl]CdCl3 with a large piezoelectric effect was investigated. The electric field manipulation efficiency for the allowed transitions was determined by the pulsed electron paramagnetic resonance. The orientation-included Hamiltonian of the spin-electric coupling effect was obtained via simulating the angle-dependent electric field modulated continuous-wave electron paramagnetic resonance. The results demonstrate that the applied electric field affects not only the principal values of the zero-field splitting tensor but also its principal axis directions. This work proposes and exemplifies a route to understand the spin-electric coupling effect originating from the crystal field imposed on a spin ion being modified by the applied electric field, which may guide the rational screening and designing of hybrid perovskite ferroelectrics that satisfy the efficiency requirement of electric field manipulation of spins in quantum information applications.

Construction of Ideal One-Dimensional Spin Chains by Topochemical Dehydration/Rehydration Route.

One-dimensional (1D) Heisenberg antiferromagnets are of great interest due to their intriguing quantum phenomena. However, the experimental realization of such systems with large spin S remains challenging because even weak interchain interactions induce long-range ordering. In this study, we present an ideal 1D S = 5/2 spin chain antiferromagnet achieved through a multistep topochemical route involving dehydration and rehydration. By desorbing three water molecules from (2,2'-bpy)FeF3(H2O)·2H2O (2,2'-bpy = 2,2'-bipyridyl) at 150 °C and then intercalating two water molecules at room temperature (giving (2,2'-bpy)FeF3·2H2O 1), the initially isolated FeF3ON2 octahedra combine to form corner-sharing FeF4N2 octahedral chains, which are effectively separated by organic and added water molecules. Mössbauer spectroscopy reveals significant dynamical fluctuations down to 2.7 K, despite the presence of strong intrachain interactions. Moreover, results from electron spin resonance (ESR) and heat capacity measurements indicate the absence of long-range order down to 0.5 K. This controlled topochemical dehydration/rehydration approach is further extended to (2,2'-bpy)CrF3·2H2O with S = 3/2 1D chains, thus opening the possibility of obtaining other low-dimensional spin lattices.

Platelet Membrane-Coated Curcumin-PLGA Nanoparticles Promote Astrocyte-Neuron Transdifferentiation for Intracerebral Hemorrhage Treatment.

Intracerebral hemorrhage (ICH) is a hemorrhagic disease with high mortality and disability rates. Curcumin is a promising drug for ICH treatment due to its multiple biological activities, but its application is limited by its poor watersolubility and instability. Herein, platelet membrane-coated curcumin polylactic-co-glycolic acid (PLGA) nanoparticles (PCNPs) are prepared to achieve significantly improved solubility, stability, and sustained release of curcumin. Fourier transform infrared spectra and X-ray diffraction assays indicate good encapsulation of curcumin within nanoparticles. Moreover, it is revealed for the first time that curcumin-loaded nanoparticles can not only suppress hemin-induced astrocyte proliferation but also induce astrocytes into neuron-like cells in vitro. PCNPs are used to treat rat ICH by tail vein injection, using in situ administration as control. The results show that PCNPs are more effective than curcumin-PLGA nanoparticles in concentrating on hemorrhagic lesions, inhibiting inflammation, suppressing astrogliosis, promoting neurogenesis, and improving motor functions. The treatment efficacy of intravenously administered PCNPs is comparable to that of in situ administration, indicating a good targeting effect of PCNPs on the hemorrhage site. This study provides a potent treatment for hemorrhagic injuries and a promising solution for efficient delivery of water-insoluble drugs using composite materials of macromolecules and cell membranes.

Association between the atherogenic index of plasma trajectory and risk of heart failure among hypertensive patients: a prospective cohort study.

BACKGROUND: The atherogenic index of plasma (AIP) has been shown to be positively correlated with cardiovascular events. However, it remains unclear whether hypertensive patients with long-term high AIP levels are at greater risk of developing heart failure (HF). Therefore, the aim of this study was to investigate the association between AIP trajectory and the incidence of HF in hypertensive patients. METHODS: This prospective study included 22,201 hypertensive patients from the Kailuan Study who underwent three waves of surveys between 2006 and 2010. Participants were free of HF or cancer before or during 2010. The AIP was calculated as the logarithmic conversion ratio of triglycerides to high-density lipoprotein cholesterol. Latent mixed modeling was employed to identify different trajectory patterns for AIP during the exposure period (2006-2010). Cox proportional hazard models were then used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for incident HF among different trajectory groups. RESULTS: Four distinct trajectory patterns were identified through latent mixture modeling analysis: low-stable group (n = 3,373; range, -0.82 to -0.70), moderate-low stable group (n = 12,700; range, -0.12 to -0.09), moderate-high stable group (n = 5,313; range, 0.53 to 0.58), and elevated-increasing group (n = 815; range, 1.22 to 1.56). During a median follow-up period of 9.98 years, a total of 822 hypertensive participants experienced HF. After adjusting for potential confounding factors, compared with those in the low-stable group, the HR and corresponding CI for incident HF in the elevated-increasing group, moderate-high stable group, and moderate-low stable group were estimated to be 1.79 (1.21,2.66), 1.49 (1.17,1.91), and 1.27 (1.02,1.58), respectively. These findings remained consistent across subgroup analyses and sensitivity analyses. CONCLUSION: Prolonged elevation of AIP in hypertensive patients is significantly associated with an increased risk of HF. This finding suggests that regular monitoring of AIP could aid in identifying individuals at a heightened risk of HF within the hypertensive population.

Using combination of albumin to fibrinogen ratio and prognostic nutritional index model for predicting disease activity in patients with systemic lupus erythematosus.

Background: Systemic lupus erythematosus (SLE) is chronic autoimmune disease with multiple organ damage and is associated with poor prognosis and high mortality. Identification of universal biomarkers to predict SLE activity is challenging due to the heterogeneity of the disease. This study aimed to identify the indicators that are sensitive and specific to predict activity of SLE.Methods: We retrospectively analyzed 108 patients with SLE. Patients were categorized into SLE with activity and without activity groups on the basis of SLE disease activity index. We analyzed the potential of routine and novel indicators in predicting the SLE activity using receiver operating characteristic curves and multivariate logistic regression. The Spearman method was used to understand the correlation between albumin to fibrinogen ratio (AFR), prognostic nutritional index (PNI), AFR-PNI model and disease activity.Results: SLE with activity group had higher ESR, CRP, D-dimer, fibrinogen, CRP to albumin ratio, positive rate of anti-dsDNA and ANUA, and lower C3, total bilirubin, total protein, albumin, albumin/globulin, creatinine, high density liptein cholesterol, hemoglobin, hematocrit, lymphocyte count, positive rate of anti-SSA, AFR, PNI than SLE without activity. A further established model based on combination of AFR and PNI (AFR-PNI model) showed prominent value in distinguishing SLE with activity patients from SLE without activity patients. In addition, the sensitivity and specificity of AFR-PNI model + anti-dsDNA combination model were superior to AFR-PNI model. AFR and PNI were risk factors for SLE activity. Moreover, AFR+PNI model correlated with disease activity and AFR-PNI model was associated with fever, pleurisy, pericarditis, renal involvement.Conclusion: These findings suggest that predictive model based on combination of AFR and PNI may be useful markers to identify active SLE in clinical practice.

Form II to form I transition in solution-crystallized isotactic polybutene-1.

Different polymer chains in a solution or melt have different conformations with corresponding entropy at each moment, which would be confined after crystallization. Equilibrium concept-based conformation or conformational entropy depends on chain dynamics, which is related to the effect of energy on conformational changes in polymer chains. Herein, an isotactic polybutene-1 (iPB-1) crystal was crystallized from solution by adding a precipitant at various temperatures. The solution-crystallized iPB-1 crystal was heated to 100 °C to obtain form II at different heat rates and the transition of form II was characterized. It was found that the form II to form I transition was not only related to the precipitation temperature but also to the heating rate of the solution-crystallized iPB-1. Thus, both precipitation temperature and heating rate determine the formation temperature of form II, i.e., form II that crystallized at lower temperature would transform faster. The results indicate that the conformation or conformational entropy of the amorphous region in iPB-1 is important to understand crystal transition.

Catalytic Asymmetric Synthesis of 3,4'-Piperidinoyl Spirooxindoles via [3 + 3] Annulation of 3-Aminobenzofurans and Isatin-Derived Enals.

A chiral NHC-catalyzed [3 + 3] cycloaddition reaction of 3-aminobenzofurans with isatin-derived enals has been documented, furnishing 3,4'-piperidinoyl spirooxindoles bearing a quaternary stereocenter with good yields and excellent enantioselectivities. Further gram-scale preparation and synthetic transformation of the cycloadducts to δ-amino acid derivative demonstrated good practicality and applicability of this reaction.

Achieving High Energy Storage Performance under a Low Electric Field in KNbO3-Doped BNT-Based Ceramics.

Ceramic capacitors have great potential for application in power systems due to their fantastic energy storage performance (ESP) and wide operating temperature range. In this study, the (1 - x)Bi0.5Na0.47Li0.03Sn0.01Ti0.99O3-xKNbO3 (BNLST-xKN) energy storage ceramics were synthesized through the solid-phase reaction method. The addition of KN disrupts the long-range ferroelectric order of the BNLST ceramic, inducing the emergence of polar nanoregions (PNRs), which enhances the ESP of the ceramics. The BNLST-0.2KN ceramic demonstrates a high recovered energy density (Wrec ∼ 3.66 J/cm3) and efficiency (η ∼ 85.8%) under a low electric field of 210 kV/cm. Meantime, it exhibits a large current density (CD ∼ 831.74 A/cm2), high power density (PD ∼ 78.86 MW/cm3), and fast discharge rate (t0.9 ∼ 0.1 µs), along with good temperature stability and excellent fatigue stability. These properties make the BNLST-0.2KN ceramic a promising candidate for energy storage applications in low electric fields.

Structure-Based Identification of Organoruthenium Compounds as Nanomolar Antagonists of Cannabinoid Receptors.

Metal complexes exhibit a diverse range of coordination geometries, representing novel privileged scaffolds with convenient click types of preparation inaccessible for typical carbon-centered organic compounds. Herein, we explored the opportunity to identify biologically active organometallic complexes by reverse docking of a rigid, minimum-size octahedral organoruthenium scaffold against thousands of protein-binding pockets. Interestingly, cannabinoid receptor type 1 (CB1) was identified based on the docking scores and the degree of overlap between the docked organoruthenium scaffold and the hydrophobic scaffold of the cocrystallized ligand. Further structure-based optimization led to the discovery of organoruthenium complexes with nanomolar binding affinities and high selectivity toward CB2. Our work indicates that octahedral organoruthenium scaffolds may be advantageous for targeting the large and hydrophobic binding pockets and that the reverse docking approach may facilitate the discovery of novel privileged scaffolds, such as organometallic complexes, for exploring chemical space in lead discovery.

Angular-resolved Rabi oscillations of orthorhombic spins in a Co(II) molecular qubit.

Magnetic molecules are promising candidates for quantum information processing (QIP) due to their tunable electron structures and quantum properties. A high spin Co(II) complex, CoH2dota, is studied for its potential to be used as a quantum bit (qubit) utilizing continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) spectroscopy at low temperature. On the X-band microwave energy scale, the system can be treated as an effective spin 1/2 with a strongly anisotropic g-tensor resulting from the significant spin-orbital coupling. An experimental and theoretical study is conducted to investigate the anisotropic Rabi oscillations of the two magnetically equivalent spin centres with different orientations in a single crystal sample, which aims to verify the relationship between the Rabi frequency and the orientation of the g-tensor. The findings of this study show that an effective quantum manipulation method is developed for orthorhombic spin systems.

Structurally Diverse Macrolactams from an Antarctic Streptomyces Species.

Twelve new polyenic macrolactams, cyclamenols G-R (1 and 3-13), together with the known analogue cyclamenol A (2), were isolated from Streptomyces sp. OUCMDZ-4348. Their structures were elucidated by spectroscopic analysis, quantum chemical calculations, chemical derivatizations, and Mosher's methods. The sequenced genome of OUCMDZ-4348 revealed the putative biosynthetic gene cluster of cyclamenols. It was proposed that the polycyclic natural products, cyclamenols H-R, might be formed from cyclamenols A and G through nonenzymatic intramolecular cycloadditions and oxidative cyclizations.

Nonenzymatic Sequestering of Formaldehyde into the Antibiotic Methylene-Bridged Dimer Phaeochromycin F by Streptomyces sp. OUCMDZ-4982 as a Possible Multipronged Chemical Defense Mechanism.

Metabolites with high chemical reactivity serve important roles in chemical defenses of organisms. Formaldehyde, as a simple and highly reactive small molecule, can be produced by microorganisms, plants, and animals. Its toxicity is well known, but information about its other biological functions remains scarce. Here, we report that the natural product SEK34b produced by Streptomyces species can react nonenzymatically with formaldehyde in water to yield the methylene-bridged dimer phaeochromycin F. This process can eliminate the toxic substance formaldehyde produced by Staphylococcus aureus. Furthermore, there is a substantial inhibitory impact of phaeochromycin F on S. aureus. We hypothesize that these constitute an integrated system of defense and attack of Streptomyces species against competitors. Our study indicates that formaldehyde can react with vancomycin and tigecycline under mild conditions to generate the derivatives bearing an imidazolidin-4-one moiety, thereby reducing the antibacterial activity of these antibiotics. These data provide a possible chemical interaction mechanism of bacteria involving the nonenzymatic reactions of formaldehyde with highly reactive natural products.

Relationship of the trajectory of the triglyceride-glucose index with heart failure: the Kailuan study.

BACKGROUND: A high triglyceride-glucose index (TyG) is associated with a higher risk of incident heart failure. However, the effects of longitudinal patterns of TyG index on the risk of heart failure remain to be characterized. Therefore, in the present study, we aimed to characterize the relationship between the trajectory of TyG index and the risk of heart failure. METHODS: We performed a prospective study of 56,149 participants in the Kailuan study who attended three consecutive surveys in 2006-2007, 2008-2009, and 2010-2011 and had no history of heart failure or cancer before the third wave survey (2010-2011). The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2], and we used latent mixture modeling to characterize the trajectory of the TyG index over the period 2006-2010. Additionally, Cox proportional risk models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for incident heart failure for the various TyG index trajectory groups. RESULTS: From 2006 to 2010, four different TyG trajectories were identified: low-stable (n = 13,554; range, 7.98-8.07), moderate low-stable (n = 29,435; range, 8.60-8.65), moderate high-stable (n = 11,262; range, 9.31-9.30), and elevated-stable (n = 1,898; range, 10.04-10.25). A total of 1,312 new heart failure events occurred during a median follow-up period of 10.04 years. After adjustment for potential confounders, the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident heart failure for the elevated-stable, moderate high-stable, and moderate low-stable groups were 1.55 (1.15, 2.08), 1.32 (1.08, 1.60), and 1.17 (0.99, 1.37), respectively, compared to the low-stable group. CONCLUSIONS: Higher TyG index trajectories were associated with a higher risk of heart failure. This suggests that monitoring TyG index trajectory may help identify individuals at high risk for heart failure and highlights the importance of early control of blood glucose and lipids for the prevention of heart failure.

Bronchial thermoplasty decreases airway remodeling by inhibiting autophagy via the AMPK/mTOR signaling pathway.

Bronchial thermoplasty (BT), an effective treatment for severe asthma, requires heat to reach the airway to reduce the mass of airway smooth muscle cells (ASMCs). Autophagy is involved in the pathological process of airway remodeling in patients with asthma. However, it remains unclear whether autophagy participates in controlling airway remodeling induced by BT. In this study, we aim to elucidate the autophagy-mediated molecular mechanisms in BT. Our study reveal that the number of autophagosomes and the level of alpha-smooth muscle actin (α-SMA) fluorescence are significantly decreased in airway biopsy tissues after BT. As the temperature increased, BT causes a decrease in cell proliferation and a concomitant increase in the apoptosis of human airway smooth muscle cells (HASMCs). Furthermore, increase in temperature significantly downregulates cellular autophagy, autophagosome accumulation, the LC3II/LC3I ratio, and Beclin-1 expression, upregulates p62 expression, and inhibits the AMPK/mTOR pathway. Furthermore, cotreatment with AICAR (an AMPK agonist) or RAPA (an mTOR antagonist) abolishes the inhibition of autophagy and attenuates the increase in the apoptosis rate of HASMCs induced by the thermal effect. Therefore, we conclude that BT decreases airway remodeling by blocking autophagy induced by the AMPK/mTOR signaling pathway in HASMCs.

Measurement Modeling and Performance Analysis of a Bionic Polarimetric Imaging Navigation Sensor Using Rayleigh Scattering to Generate Scattered Sunlight.

The bionic polarimetric imaging navigation sensor (BPINS) is a navigation sensor that provides absolute heading, and it is of practical engineering significance to model the measurement error of BPINS. The existing BPINSs are still modeled using photodiode-based measurements rather than imaging measurements and are not modeled systematically enough. This paper proposes a measurement performance analysis method of BPINS that takes into account the geometric and polarization errors of the optical system. Firstly, the key error factors affecting the overall measurement performance of BPINS are investigated, and the Stokes vector-based measurement error model of BPINS is introduced. Secondly, based on its measurement error model, the effect of the error source on the measurement performance of BPINS is quantitatively analyzed using Rayleigh scattering to generate scattered sunlight as a known incident light source. The numerical results show that in angle of E-vector (AoE) measurement, the coordinate deviation of the principal point has a greater impact, followed by grayscale response inconsistency of CMOS and integration angle error of micro-polarization array, and finally lens attenuation; in degree of linear polarization (DoLP) measurement, the grayscale response inconsistency of CMOS has a more significant impact. This finding can accurately guide the subsequent calibration of BPINS, and the quantitative results provide an important theoretical reference for its optimal design.

Comparing the mechanisms of syntrophic volatile fatty acids oxidation and methanogenesis recovery from ammonia stress in regular and biochar-assisted anaerobic digestion: Different roads lead to the same goal.

Biochar has been recognized as a promising additive to mitigate ammonia inhibition during syntrophic methanogenesis, while the key function of biochar in this process is still in debates. This study clarified the distinct mechanisms of syntrophic volatile fatty acids -oxidizing and methanogenesis recovery from ammonia inhibition in regular and biochar-assisted anaerobic digestion. Under 5 g/L ammonia stress, adding biochar shortened the methanogenic lag time by 10.9% and dramatically accelerated the maximum methane production rate from 60.3 to 94.7 mLCH4/gVSsludge/d. A photometric analysis with a nano-WO3 probe revealed that biochar enhanced the extracellular electron transfer (EET) capacity of suspended microbes (Pearson's r = -0.98), confirming that biochar facilitated methanogenesis by boosting EET between syntrophic butyrate oxidizer and methanogens. Same linear relationship between EET capacity and methanogenic rate was not observed in the control group. Microbial community integrating functional genes prediction analysis uncovered that biochar re-shaped syntrophic partners by enriching Constridium_sensu_stricto/Syntrophomonas and Methanosarcina. The functional genes encoding Co-enzyme F420 hydrogenase and formylmethanofuran dehydrogenase were upregulated by 1.4-2.3 times, consequently enhanced the CO2-reduction methanogenesis pathway. Meanwhile, the abundances of gene encoding methylene-tetrahydrofolate transformation, a series of intermediate processes involved in acetate oxidation, in the biochar-assisted group were 28.2-63.7% higher than these in control group. Comparatively, Methanosaeta played a pivotal role driving aceticlastic methanogenesis in the control group because the abundance of gene encoding acetyl-CoA decarbonylase/synthase complex increased by 1.9 times, suggesting an aceticlastic combining H2-based syntrophic methanogenesis pathway was established in control group to resist ammonia stress. A 2nd period experiment elucidated that although depending on distinct mechanisms, the volatile fatty acid oxidizers and methanogens in both groups developed sustained and stable strategies to resist ammonia stress. These findings provided new insights to understand the distinct methanogenic recovery strategy to resist toxic stress under varied environmental conditions.

Study on the Properties of FEVE Modified with Ag2O/OH-MWCNTS Nanocomposites for Use as Adhesives for Wooden Heritage Objects.

The durability of wooden heritage objects and sites can be affected by external environmental factors, leading to decay, cracking, and other forms of deterioration, which might ultimately result in significant and irreversible loss. In this study, a FEVE resin was modified with Ag2O/OH-MWCNTS (MA), denoted as MAF, where three concentrations were prepared using in situ precipitation, and the resulting composite adhesive was characterized by a high viscosity and effective bacteriostatic properties, demonstrating a better viscosity and thermal stability, as well as antibacterial properties, than pure FEVE resin. The results show that MAF adhesives present good thermal stability, as evidenced by a lower mass loss rate following treatment at 800 °C compared to the pure FEVE resin. At a consistent shear rate, the viscosity of MAF demonstrates a notable increase with the proportion of MA, which is better than that of FEVE. This suggests that the nano-Ag2O particles in MA act as physical crosslinking agents in FEVE, improving the viscosity of the composite adhesive MAF. The adhesion strength between MAF and wood exhibits a similar trend, with wooden samples showing higher shear strengths as the proportion of MA increases in comparison to FEVE. Simultaneously, the antibacterial effects of the MAF adhesive exceeded 1 mm for Trichoderma, Aspergillus niger, and white rot fungi. The antibacterial activity of the MAF adhesive exhibited a direct correlation with the concentration of Ag2O/OH-MWCNTS, with the most pronounced inhibitory effect observed on Trichoderma. The MAF adhesive demonstrates promising prospects as an adhesive for wooden heritage artifacts, offering a novel approach for the rapid, environmentally friendly, and efficient development of composite adhesives with superior adhesive properties.

Structural insights into the Oryza sativa cation transporters HKTs in salt tolerance.

The high-affinity potassium transporters (HKTs), selectively permeable to either Na+ alone or Na+/K+, play pivotal roles in maintaining plant Na+/K+ homeostasis. Although their involvement in salt tolerance is widely reported, the molecular underpinnings of Oryza sativa HKTs remain elusive. In this study, we elucidate the structures of OsHKT1;1 and OsHKT2;1, representing two distinct classes of rice HKTs. The dimeric assembled OsHKTs can be structurally divided into four domains. At the dimer interface, a half-helix or a loop in the third domain is coordinated by the C-terminal region of the opposite subunit. Additionally, we present the structures of OsHKT1;5 salt-tolerant and salt-sensitive variants, a key quantitative trait locus associated with salt tolerance. The salt-tolerant variant of OsHKT1;5 exhibits enhanced Na+ transport capability and displays a more flexible conformation. These findings shed light on the molecular basis of rice HKTs and provide insights into their role in salt tolerance.

Research on Strengthening Fragile Paper with Polyvinylamine.

Paper documents are an important carrier of information related to human civilization, with the reinforcement and protection of fragile paper documents being a key aspect of their protection. This research utilized amphoteric polyvinylamine polymer as a paper reinforcement agent, strengthening the Xuan paper commonly used in paper documents. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), solid-state 13C NMR, and other analytical methods were employed to compare the physical properties, micro-morphology, crystallinity, and aging resistance of the paper before and after reinforcement. Research was conducted on the effects of reinforcement, the aging resistance, and the effects on the fiber structure. The results indicate that polyethylenimine has a filling and bridging effect between the paper fibers. After treatment with polyethylenimine, there was a significant improvement in the folding endurance and tensile strength of the paper. Additionally, the paper maintains a good mechanical strength even after undergoing dry heat and humid aging.