Copper-catalyzed deborodeuteration of arylboronic acids/borates using D2O as the deuterium source.

A straightforward copper-catalyzed deborodeuteration of arylboronic acids and borates was achieved, employing the cost-effective deuterium source D2O. This protocol demonstrates wide substrate applicability, exceptional deuterium incorporation efficiency, and favorable tolerance for various functional groups. Therefore, this approach offers a mild option for further applications in valuable deuterium molecule synthesis.

Origin of ultrahigh-performance barium titanate-based piezoelectrics: Stannum-induced intrinsic and extrinsic contributions.

Despite the pivotal role of stannum doping in achieving ultrahigh piezoelectric performance in barium titanate-based ceramics, the fundamental mechanisms underlying this enhancement remain elusive. Here, we introduce a single variable nonstoichiometric stannum strategy in lead-free barium titanate-based ceramics with giant piezoelectricity, revealing that stannum doping contributes intrinsically and extrinsically to enhance piezoelectricity. Density functional theory calculations elucidate the intrinsic enhancement of polarization arising from lattice distortion and increased space for titanium-oxygen bonds induced by optimal stannum doping, which is corroborated by Rayleigh analysis. A phase transition from ferroelectric multiphase coexistence to paraelectric phase is observed, alongside a rapid miniaturized and eventually disappeared domains with increasing stannum doping. This evolution in phase structure and domain configuration induces a nearly vanishing polarization anisotropy and low domain wall energy, facilitating easy polarization rotation and domain wall motion, thereby significantly contributing to the extrinsic piezoelectric response. Consequently, the origins of ultrahigh performance can be attributed to the synergistic effect of stannum-induced intrinsic and extrinsic contributions in barium titanate-based ceramics. This study provides fundamental insights into the role of doping elements and offers guidance for the design of high-performance piezoelectrics.

Rhodium-catalyzed intramolecular cyclization for synthesizing thiodihydropyrans.

Addressing the challenge of constructing multi-substituted dihydropyrans, we present an efficient synthesis method for oxygen-containing heterocycles. Using thiones and metal carbenes, we employed xanthate and triazole to intramolecularly synthesize dihydropyran or dihydrofuran compounds. 1,2-Hydride migration was inhibited, and thiodihydropyrans were obtained in excellent yields. A mechanism proceeding through a Rh-carbene intermediate is proposed for the multi-substituted dihydropyrans synthesis.

High-Energy Polynitrogen N10 Stabilized on Multi-Walled Carbon Nanotubes.

The synthesis of stable polynitrogen compounds with high-energy density has long been a major challenge. The cyclo-pentazolate anion (cyclo-N5 -) is successfully converted into aromatic and structurally symmetric bipentazole (N10) via electrochemical synthesis using highly conductive multi-walled carbon nanotubes (MWCNTs) as the substrate and sodium pentazolate hydrate ([Na(H2O)(N5)]·2H2O) as the raw material. Attenuated total refraction Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and density functional theory calculations confirmed the structure and homogeneous distribution of N10 in the sidewalls of the MWCNTs (named MWCNT-N10-n m). The MWCNT-N10-2.0 m is further used as a catalyst for electrochemical oxygen reduction to synthesize hydrogen peroxide from oxygen with a two-electron selectivity of up to 95%.

The cGAS-STING pathway in COPD: targeting its role and therapeutic potential.

Chronic obstructive pulmonary disease(COPD) is a gradually worsening and fatal heterogeneous lung disease characterized by airflow limitation and increasingly decline in lung function. Currently, it is one of the leading causes of death worldwide. The consistent feature of COPD is airway inflammation. Several inflammatory factors are known to be involved in COPD pathogenesis; however, anti-inflammatory therapy is not the first-line treatment for COPD. Although bronchodilators, corticosteroids and roflumilast could improve airflow and control symptoms, they could not reverse the disease. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway plays an important novel role in the immune system and has been confirmed to be a key mediator of inflammation during infection, cellular stress, and tissue damage. Recent studies have emphasized that abnormal activation of cGAS-STING contributes to COPD, providing a direction for new treatments that we urgently need to develop. Here, we focused on the cGAS-STING pathway, providing insight into its molecular mechanism and summarizing the current knowledge on the role of the cGAS-STING pathway in COPD. Moreover, we explored antagonists of cGAS and STING to identify potential therapeutic strategies for COPD that target the cGAS-STING pathway.

[Spatiotemporal Variation Characteristics and Driving Factors of Cultivated Land NPP in the Shandong Area Around the Bohai Sea].

The Bohai Rim Plain is an important grain-producing area in China. The cultivated land resources have great potential for production, but there are many influencing factors. Understanding the spatiotemporal change characteristics and driving factors of the net primary productivity （NPP） of cultivated land vegetation in this region is of great significance to improve the regional cultivated land production conditions, excavate and enhance the production capacity of cultivated land, and ensure national food security. In this study, Theil-Sen Median trend analysis, Mann-Kendall significance test, Hurst index, and other methods were used to explore the spatiotemporal change characteristics, stability, and sustainability of regional cultivated land NPP. The influence of driving factors on the spatial heterogeneity of cultivated land NPP was analyzed by using optical parameters-based geographical detectors. The results showed that： ① From 2001 to 2019, due to the expansion of construction land during industrialization and urbanization, the cumulative decrease in the area of cultivated land in the Shandong area around the Bohai Sea was 2 004.51 km2. ② During the selected research period, the interannual variation of average cultivated land NPP showed a fluctuating and increasing trend. In terms of spatial distribution, the NPP of cultivated land was bounded by the Dongying District, with the spatial heterogeneity in the north being significantly lower than that in the south. ③ The area with increasing NPP of cultivated land accounted for 88.06% of the total area of cultivated land, mainly with low and medium fluctuations. The NPP of cultivated land will maintain an overall sustained trend of increase across the region in the future. ④ The average annual relative humidity study area had the strongest explanatory power for the spatial variability of NPP in cropland, with a q-value of 0.26, followed by surface soil salinity and subsoil salinity, with q-values greater than 0.2. The interactions between the different drivers all showed either nonlinear enhancement or bifactorial enhancement. The results of this study will help to reveal the characteristics of the changes in cultivated land production capacity and its driving forces in the Bohai Sea region and also provide a theoretical basis for the ecological protection and sustainable development of the region.

Catalytic divergence of O-methyltransferases shapes the chemo-diversity of polymethoxylated bibenzyls in Dendrobium catenatum.

Erianin, crepidatin, and chrysotobibenzyl are typical medicinal polymethoxylated bibenzyls (PMBs) that are commercially produced in Dendrobium species. PMBs' chemo-diversity is mediated by the manifold combinations of O-methylation and hydroxylation in a definite order, which remains unsolved. To unequivocally elucidate the methylation mechanism of PMBs, 15 possible intermediates in the biosynthetic pathway of PMBs were chemically synthesized. DcOMT1-5 were highly expressed in tissues where PMBs were biosynthesized, and their expression patterns were well-correlated with the accumulation profiles of PMBs. Moreover, cell-free orthogonal tests based on the synthesized intermediates further confirmed that DcOMT1-5 exhibited distinct substrate preferences and displayed hydroxyl-group regiospecificity during the sequential methylation process. The stepwise methylation of PMBs was discovered from SAM to dihydro-piceatannol (P) in the following order: P → 3-MeP → 4-OH-3-MeP → 4-OH-3,5-diMeP → 3,3'(4'),5-triMeP → 3,4,4',5-tetraMeP (erianin) or 3,3',4,5-tetraMeP (crepidatin) → 3,3',4,4',5-pentaMeP (chrysotobibenzyl). Furthermore, the regioselectivities of DcOMTs were investigated by ligand docking analyses which corresponded precisely with the catalytic activities. In summary, the findings shed light on the sequential catalytic mechanisms of PMB biosynthesis and provide a comprehensive PMB biosynthetic network in D. catenatum. The knowledge gained from this study may also contribute to the development of plant-based medicinal applications and the production of high-value PMBs.

NAC Transcription Factor PpNAP4 Promotes Chlorophyll Degradation and Anthocyanin Synthesis in the Skin of Peach Fruit.

Chlorophyll (Chl) catabolism and anthocyanin synthesis play pivotal roles in determining the final skin color of fruits during maturation. However, in peach (Prunus persica) fruit, the regulatory mechanism governing skin color, especially the Chl catabolism, remains largely elusive. In this study, we identified ten Chl catabolic genes (CCGs), with PpSGR emerging as a key regulator in Chl degradation in peaches. Furthermore, a NAC-like, activated by AP3/P1 (NAP) transcription factor (TF), PpNAP4, was identified as a positive modulator of Chl breakdown. PpNAP4 induced the expression of PpSGR and other CCGs, including PpPPH, PpPAO, and PpTIC55-2, by directly binding to their promoters. Overexpression of PpNAP4 resulted in a heightened expression of these genes and accelerated Chl degradation. Notably, PpNAP4 also positively regulated the expression of PpANS and PpMYB10.1, one key structural gene and a core transcriptional regulator of anthocyanin synthesis, thereby contributing to fruit coloration. In summary, our findings elucidate that PpNAP4 serves as a pivotal regulator in determining the final skin color of peach by orchestrating Chl degradation and anthocyanin accumulation through direct activation of multiple CCGs and anthocyanin related genes.

Asymmetric Synthesis and Biological Evaluation of Platensilin, Platensimycin, Platencin, and Their Analogs via a Bioinspired Skeletal Reconstruction Approach.

Platensilin, platensimycin, and platencin are potent inhibitors of ß-ketoacyl-acyl carrier protein synthase (FabF) in the bacterial and mammalian fatty acid synthesis system, presenting promising drug leads for both antibacterial and antidiabetic therapies. Herein, a bioinspired skeleton reconstruction approach is reported, which enables the unified synthesis of these three natural FabF inhibitors and their skeletally diverse analogs, all stemming from a common ent-pimarane core. The synthesis features a diastereoselective biocatalytic reduction and an intermolecular Diels-Alder reaction to prepare the common ent-pimarane core. From this intermediate, stereoselective Mn-catalyzed hydrogen atom-transfer hydrogenation and subsequent Cu-catalyzed carbenoid C-H insertion afford platensilin. Furthermore, the intramolecular Diels-Alder reaction succeeded by regioselective ring opening of the newly formed cyclopropane enables the construction of the bicyclo[3.2.1]-octane and bicyclo[2.2.2]-octane ring systems of platensimycin and platencin, respectively. This skeletal reconstruction approach of the ent-pimarane core facilitates the preparation of analogs bearing different polycyclic scaffolds. Among these analogs, the previously unexplored cyclopropyl analog 47 exhibits improved antibacterial activity (MIC80 = 0.0625 µg/mL) against S. aureus compared to platensimycin.

[Spatial Prediction and Influencing Factors Analysis of Soil Salinization in Coastal Area Based on MGWR].

Quantitative analysis of the spatial non-stationary characteristics of soil salinization influencing factors and the prediction of its spatial distribution are of great significance for the rational use of coastal saline soil resources and the formulation of local prevention and control measures. In this study, the Hekou District of Dongying City, Shandong Province, was used as the study area, and the descriptive statistics of soil salinization status were conducted using classical statistical methods. Spatial autocorrelation theory was used to explore the characteristics of global and local spatial structure of soil salinization in the study area. Influential factors related to soil salinity were selected, and multivariate linear regression （MLR）, geographically weighted regression （GWR）, and multi-scale geographically weighted regression （MGWR） methods were used to model and predict the spatial distribution of soil salinity in the study area and to analyze the spatial heterogeneity of the effects of different influencing factors on soil salinity. The results showed that： ① The mean value of soil salinity in the study area was 5.84 g·kg-1, indicating severe salinization, with a global Moran's I index of 0.19 （P<0.00） and obvious spatial aggregation characteristics. ② Among the three models, the MGWR model had the highest modeling accuracy. Compared with that of the MLR model, the Radj2 of GWR and MGWR improved by 0.05 and 0.07, respectively, and the RSS decreased by 210.13 and 179.95, respectively. ③ The results of MGWR regression showed that the spatial distribution of soil salinity appeared to be mainly affected by the middle soil salinity, soil clay content, and vegetation cover from the mean values of standardized regression coefficients of different influencing factors. Different influencing factors had significant spatial non-stationary characteristics on soil salinization. ④ The results of the spatial distribution prediction of soil salinity in MGWR showed that the areas of high soil salinity （≥6 g·kg-1） were mainly distributed in the northern part of the study area, with an overall spatial trend of decreasing from the coast to the interior. The results of the study can be used as a reference for the analysis and predictive mapping of factors affecting soil salinization in the county and on a larger scale using MGWR.

Molecular Engineering Regulation Achieving Out-of-Plane Polarization in Rare-Earth Hybrid Double Perovskites for Ferroelectrics and Circularly Polarized Luminescence.

Out-of-plane polarization is a highly desired property of two-dimensional (2D) ferroelectrics for application in vertical sandwich-type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out-of-plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S-3-hydroxylquinuclidinium), we designed a molecular strategy of F-substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S-3-fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out-of-plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F-substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F-substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro-nano optoelectronic devices.

Aerobic Oxysulfonylation of Olefins Using N-Sulfonylaminophthalimides as Sulfonyl Radical Precursors.

Readily accessible N-sulfonylaminophthalimides were developed to be efficient sulfonyl radical precursors upon being treated with a base/oxidant under mild conditions. The method was applied to the oxysulfonylation of olefins, providing ß-ketosulfones and isobenzofurans stereoselectively. On the basis of control experiments, density functional theory calculations, and the literature, a plausible radical mechanism was proposed. The findings offered a chance to develop novel radical precursors based on diversely substituted N-aminophthalimides, which might establish a universal mild approach for the generation of various radicals.

Observation of reentrant metal-insulator transition in a random-dimer disordered SSH lattice.

The interrelationship between localization, quantum transport, and disorder has remained a fascinating focus in scientific research. Traditionally, it has been widely accepted in the physics community that in one-dimensional systems, as disorder increases, localization intensifies, triggering a metal-insulator transition. However, a recent theoretical investigation [Phys. Rev. Lett. 126, 106803] has revealed that the interplay between dimerization and disorder leads to a reentrant localization transition, constituting a remarkable theoretical advancement in the field. Here, we present the first experimental observation of reentrant localization using an experimentally friendly model, a photonic SSH lattice with random-dimer disorder, achieved by incrementally adjusting synthetic potentials. In the presence of correlated on-site potentials, certain eigenstates exhibit extended behavior following the localization transition as the disorder continues to increase. We directly probe the wave function in disordered lattices by exciting specific lattice sites and recording the light distribution. This reentrant phenomenon is further verified by observing an anomalous peak in the normalized participation ratio. Our study enriches the understanding of transport in disordered mediums and accentuates the substantial potential of integrated photonics for the simulation of intricate condensed matter physics phenomena.

An RPA-Assisted CRISPR/Cas12a Assay Combining Fluorescence and Lateral Flow Strips for the Rapid Detection of Enterotoxigenic Bacillus cereus.

Bacillus cereus (B. cereus) is a foodborne pathogen that can produce tripartite enterotoxins, which can cause a variety of diseases after infection. It is critical to rapidly and accurately detect strains with enteropathogenic potential to safeguard human health. In this study, a dual-signal visualized detection platform with fluorescence assay and paper-based lateral flow assay (LFA) based on recombinase polymerase amplification (RPA), CRISPR/Cas12a system, and self-developed CRISPR nucleic acid test strips was constructed for enterotoxigenic B. cereus. The genes that encode two tripartite enterotoxins─nheA, nheB, and nheC for nonhemolytic enterotoxin and hblA, hblC, and hblD for hemolysin BL─were utilized as detection targets. The platform was capable of detecting six enterotoxin genes at the same genomic DNA level. The limits of detection for each gene were 10-3 ng/µL in fluorescence assay and 10-4 ng/µL in LFA. Furthermore, 101-102 CFU/mL of B. cereus in pure culture was detected. Additionally, a smartphone miniprogram could assist in evaluating the results in LFA. The platform demonstrated good utility by detecting B. cereus in food samples, including milk and rice. The results indicate that our RPA-CRISPR/Cas12a dual-signal visualized detection platform can quickly and easily detect B. cereus with three-component enterotoxin-producing potentials. The whole analytic process took less than 60 min without complex operation or expensive equipment.

Metal-Organic Frameworks-Based Frustrated Lewis Pairs for Selective Reduction of Nitroolefins to Nitroalkanes.

Nitroalkanes serve as essential intermediates in the synthesis of pharmaceuticals, agrochemicals, and functional materials. To date, nitroalkanes are mainly prepared from homogeneous catalysts such as noble transition metal catalysts with poor recyclability. Herein, we propose a metal-organic framework-frustrated Lewis pair (MOF-FLP) heterogeneous catalyst for selectively reducing nitroolefins to nitroalkanes under moderate reaction conditions. MOF enrichment effect can significantly improve the catalytic efficiency compared to homogeneous FLP catalysts. Benefiting from the strong interaction between FLP and MOF, the MOF-FLP catalyst exhibits outstanding recyclability. This work not only provides a convenient route for nitroalkane synthesis but also showcases the potential of porous heterogeneous FLP catalysts, offering inspiration for future catalytic design strategies.

Copper-Catalyzed Synthesis of Furan-Tethered Benzocyclobutenes via Carbene-Mediated 1,4-Sulfinate Migration-Annulation.

A copper-catalyzed intramolecular cascade reaction of conjugated enynones has been achieved via a pivotal 1,4-sulfinate migration step. This process leverages a cost-effective and ecofriendly copper salt as catalyst, enabling the efficient construction of five- and four-membered rings in a rapid, sequential manner, producing furan-tethered benzocyclobutenes in good to excellent yields under mild conditions. The reaction is characterized by 100% atom economy, outstanding efficiency, and excellent diastereoselectivity in the cases studied. The robustness of this method is evidenced by its compatibility with air exposure and the use of undistilled, commercially available solvents, further enhancing its practicality.

An advanced optic-fiber differential sensing system enhanced by molecularly imprinted polymer for specific sodium benzoate detection.

A molecularly imprinted polymer (MIP) based microfiber differential demodulation sensing system for sodium benzoate (SB) concentration detection is proposed. The specific binding of MIP on the surface of microfibers with SB can lead to changes in local refractive index (RI). RI change induces a drift in the interference wavelength, which can be monitored by the power difference between two fiber Bragg gratings (FBGs). The sensing system can detect SB in the concentration range of 0.1-50 µg/ml, and interference wavelength and FBG power difference sensitivities are 0.55 nm/(µg/ml) and 2.64 dB/(µg/ml) in the low concentration range of 0.1-1 µg/ml, respectively, with a limit of detection (LOD) of 0.1 µg/ml. This microfiber differential demodulation sensing system is not only simple to fabricate, but also simplifies the demodulation equipment to reduce the cost, which providing a simple, reliable and low-cost technique for the quantitative detection of SB concentration in beverages and flavoured foods.

AP-1 and SP1 trans-activate the expression of hepatic CYP1A1 and CYP2A6 in the bioactivation of AFB1 in chicken.

Dietary exposure to aflatoxin B1 (AFB1) is harmful to the health and performance of domestic animals. The hepatic cytochrome P450s (CYPs), CYP1A1 and CYP2A6, are the primary enzymes responsible for the bioactivation of AFB1 to the highly toxic exo-AFB1-8,9-epoxide (AFBO) in chicks. However, the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1 metabolism remains unknown. Dual-luciferase reporter assay, bioinformatics and site-directed mutation results indicated that specificity protein 1 (SP1) and activator protein-1 (AP-1) motifs were located in the core region -1,063/-948, -606/-541 of the CYP1A1 promoter as well as -636/-595, -503/-462, -147/-1 of the CYP2A6 promoter. Furthermore, overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and CYP2A6. Moreover, bioactivation of AFB1 to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression, which was trans-activated owing to the upregulalion of AP-1, rather than SP1, stimulated by AFB1-induced reactive oxygen species. Additionally, nano-selenium could reduce ROS, downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6, thus alleviating the toxicity of AFB1. In conclusion, AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1 to AFBO in chicken liver, which could provide novel targets for the remediation of aflatoxicosis in chicks.

Experimental detection of the diamino-pentazolium cation and theoretical exploration of derived high energy materials.

In this work, we realized the detection of diamino-pentazolium cation (DAPZ+) in the reaction solution experimentally and proved it to be meta-diamino-pentazole based on the transition state theory. Quantum chemical methods were used to predict its spectral properties, charge distribution, stability and aromaticity. Considering that DAPZ+ has excellent detonation properties, it was further explored by assembling it with N5-, N3- and C(NO2)3- anions, respectively. The results show a strong interaction between DAPZ+ and the three anions, which will have a positive effect on its stability. Thanks to the high enthalpy of formation and density, the calculated detonation properties of the three systems are exciting, especially [DAPZ+][N5-] (D: 10,016 m·s-1; P: 37.94 GPa), whose actual detonation velocity may very likely exceed CL-20 (D: 9773 m·s-1). There is no doubt that this work will become the precursor for the theoretical exploration of new polynitrogen ionic compounds.

Association between maternal iron status and the risk of pre-eclampsia: a case-control study.

BACKGROUND AND OBJECTIVES: This study aimed to assess the associations of maternal iron status and placental iron transport proteins expression with the risk of pre-eclampsia (PE) in Chinese pregnant women. METHODS AND STUDY DESIGN: A total of 94 subjects with PE and 112 healthy pregnant women were enrolled. Fasting blood samples were collected to detect maternal iron status. The placenta samples were collected at delivery to detect the mRNA and protein expression of divalent metal transporter 1 (DMT1) and ferroportin-1 (FPN1). Logistic analysis was used to explore the associations of maternal iron status with PE risk. The associations of placental iron transport proteins with maternal iron status were explored. RESULTS: After adjusting for covariates, dietary total iron, non-heme iron intake and serum hepcidin were negatively associated with PE, with adjusted ORs (95%CIs) were 0.40 (0.17, 0.91), 0.42 (0.18, 0.94) and 0.02 (0.002, 0.13) for the highest versus lowest tertile, respectively. For the highest tertile versus lowest tertile, serum iron (4.08 (1.58, 10.57)) and ferritin (5.61 (2.36, 13.31)) were positively associated with PE. The mRNA expressions and protein levels of DMT1 and FPN1 in placenta were up-regulated in the PE group (p < 0.05). The mRNA expressions of DMT1 and FPN1 in placenta showed a negative correlation with the serum hepcidin (r = -0.71, p < 0.001; r = -0.49, p < 0.05). CONCLUSIONS: In conclusion, the maternal iron status were closely associated with PE risk, placental DMT1 and FPN1 were upregulated in PE which may be a promising target for the prevention of PE.