CircAKT3 alleviates postoperative cognitive dysfunction by stabilizing the feedback cycle of miR-106a-5p/HDAC4/MEF2C axis in hippocampi of aged mice.

Circular RNAs (circRNAs) have garnered significant attention in the field of neurodegenerative diseases including Alzheimer's diseases due to their covalently closed loop structure. However, the involvement of circRNAs in postoperative cognitive dysfunction (POCD) is still largely unexplored. To identify the genes differentially expressed between non-POCD (NPOCD) and POCD mice, we conducted the whole transcriptome sequencing initially in this study. According to the expression profiles, we observed that circAKT3 was associated with hippocampal neuronal apoptosis in POCD mice. Moreover, we found that circAKT3 overexpression reduced apoptosis of hippocampal neurons and alleviated POCD. Subsequently, through bioinformatics analysis, our data showed that circAKT3 overexpression in vitro and in vivo elevated the abundance of miR-106a-5p significantly, resulting in a decrease of HDAC4 protein and an increase of MEF2C protein. Additionally, this effect of circAKT3 was blocked by miR-106a-5p inhibitor. Interestingly, MEF2C could activate the transcription of miR-106a-5p promoter and form a positive feedback loop. Therefore, our findings revealed more potential modulation ways between circRNA-miRNA and miRNA-mRNA, providing different directions and targets for preclinical studies of POCD.

The function and therapeutic potential of transfer RNA-derived small RNAs in cardiovascular diseases: A review.

Transfer RNA-derived small RNAs (tsRNAs) are a class of small non-coding RNA (sncRNA) molecules derived from tRNA, including tRNA derived fragments (tRFs) and tRNA halfs (tiRNAs). tsRNAs can affect cell functions by participating in gene expression regulation, translation regulation, intercellular signal transduction, and immune response. They have been shown to play an important role in various human diseases, including cardiovascular diseases (CVDs). Targeted regulation of tsRNAs expression can affect the progression of CVDs. The tsRNAs induced by pathological conditions can be detected when released into the extracellular, giving them enormous potential as disease biomarkers. Here, we review the biogenesis, degradation process and related functional mechanisms of tsRNAs, and discuss the research progress and application prospects of tsRNAs in different CVDs, to provide a new perspective on the treatment of CVDs.

Knowledge, attitudes, and practices of primary healthcare practitioners regarding pharmacist clinics: a cross-sectional study in Shanghai.

BACKGROUND: Pharmacist clinics offer professional pharmaceutical services that can improve public health outcomes. However, primary healthcare staff in China face various barriers and challenges in implementing such clinics. To identify existing problems and provide recommendations for the implementation of pharmacist clinics, this study aims to assess the knowledge, attitudes, and practices of pharmacist clinics among primary healthcare providers. METHODS: A cross-sectional survey based on the Knowledge-Attitude-Practice (KAP) model, was conducted in community health centers (CHCs) and private hospitals in Shanghai, China in May, 2023. Descriptive analytics and the Pareto principle were used to multiple-answer questions. Chi-square test, Fisher's exact test, and binary logistic regression models were employed to identify factors associated with the knowledge, attitudes, and practices of pharmacist clinics. RESULTS: A total of 223 primary practitioners participated in the survey. Our study revealed that most of them had limited knowledge (60.1%, n = 134) but a positive attitude (82.9%, n = 185) towards pharmacist clinics, with only 17.0% (n = 38) having implemented them. The primary goal of pharmacist clinics was to provide comprehensive medication guidance (31.5%, n = 200), with medication education (26.3%, n = 202) being the primary service, and special populations (24.5%, n = 153) identified as key recipients. Logistic regression analysis revealed that education, age, occupation, position, work seniority, and institution significantly influenced their perceptions. Practitioners with bachelor's degrees, for instance, were more likely than those with less education to recognize the importance of pharmacist clinics in medication guidance (aOR: 7.130, 95%CI: 1.809-28.099, p-value = 0.005) and prescription reviews (aOR: 4.675, 95% CI: 1.548-14.112, p-value = 0.006). Additionally, practitioners expressed positive attitudes but low confidence, with only 33.3% (n = 74) feeling confident in implementation. The confidence levels of male practitioners surpassed those of female practitioners (p-value = 0.037), and practitioners from community health centers (CHCs) exhibited higher confidence compared to their counterparts in private hospitals (p-value = 0.008). Joint physician-pharmacist clinics (36.8%, n = 82) through collaboration with medical institutions (52.0%, n = 116) emerged as the favored modality. Daily sessions were preferred (38.5%, n = 86), and both registration and pharmacy service fees were considered appropriate for payment (42.2%, n = 94). The primary challenge identified was high outpatient workload (30.9%, n = 69). CONCLUSIONS: Although primary healthcare practitioners held positive attitudes towards pharmacist clinics, limited knowledge, low confidence, and high workload contributed to the scarcity of their implementation. Practitioners with diverse sociodemographic characteristics, such as education, age, and institution, showed varying perceptions and practices regarding pharmacist clinics.

Comparative assessment of orthodontic clear aligner versus fixed appliance for anterior retraction: a finite element study.

BACKGROUND: The aim of this study is to conduct a comparative evaluation of different designs of clear aligners and examine the disparities between clear aligners and fixed appliances. METHODS: 3D digital models were created, consisting of a maxillary dentition without first premolars, maxilla, periodontal ligaments, attachments, micro-implant, 3D printed lingual retractor, brackets, archwire and clear aligner. The study involved the creation of five design models for clear aligner maxillary anterior internal retraction and one design model for fixed appliance maxillary anterior internal retraction, which were subsequently subjected to finite element analysis. These design models included: (1) Model C0 Control, (2) Model C1 Posterior Micro-implant, (3) Model C2 Anterior Micro-implant, (4) Model C3 Palatal Plate, (5) Model C4 Lingual Retractor, and (6) Model F0 Fixed Appliance. RESULTS: In the clear aligner models, a consistent pattern of tooth movement was observed. Notably, among all tested models, the modified clear aligner Model C3 exhibited the smallest differences in sagittal displacement of the crown-root of the central incisor, vertical displacement of the central incisor, sagittal displacement of the second premolar and second molar, as well as vertical displacement of posterior teeth. However, distinct variations in tooth movement trends were observed between the clear aligner models and the fixed appliance model. Furthermore, compared to the fixed appliance model, significant increases in tooth displacement were achieved with the use of clear aligner models. CONCLUSIONS: In the clear aligner models, the movement trend of the teeth remained consistent, but there were variations in the amount of tooth displacement. Overall, the Model C3 exhibited better torque control and provided greater protection for posterior anchorage teeth compared to the other four clear aligner models. On the other hand, the fixed appliance model provides superior anterior torque control and better protection of the posterior anchorage teeth compared to clear aligner models. The clear aligner approach and the fixed appliance approach still exhibit a disparity; nevertheless, this study offers a developmental direction and establishes a theoretical foundation for future non-invasive, aesthetically pleasing, comfortable, and efficient modalities of clear aligner treatment.

Identification of key events and regulatory networks in the formation process of primordial germ cell based on proteomics.

Currently, studies have analyzed the formation mechanism of primordial germ cell (PGC) at the transcriptional level, but few at the protein level, which made the mechanism study of PGC formation not systematic. Here, we screened differential expression proteins (DEPs) regulated PGC formation by label-free proteomics with a novel sampling strategy of embryonic stem cells and PGC. Analysis of DEPs showed that multiple key events were involved, such as the transition from glycolysis to oxidative phosphorylation, activation of autophagy, low DNA methylation ensured the normal formation of PGC, beyond that, protein ubiquitination also played an important role in PGC formation. Importantly, the progression of such events was attributed to the inconsistency between transcription and translation. Interestingly, MAPK, PPAR, Wnt, and JAK signaling pathways not only interact with each other but also interact with different events to participate in the formation of PGC, which formed the PGC regulatory network. According to the regulatory network, the efficiency of PGC formation in induction system can be significantly improved. In conclusion, our results indicate that chicken PGC formation is a complex process involving multiple events and signals, which provide technical support for the specific application in PGC research.

Relationship between the expression of PD-L1 and 18F-FDG uptake in pancreatic ductal adenocarcinoma.

BACKGROUND: PD-L1 promotes glycolysis in tumour cells. We observed a correlation between high PD-L1 expression and high 18F-FDG uptake in patients with pancreatic ductal adenocarcinoma (PDAC) in a previous study. This study aims to determine the usefulness of 18F-FDG PET/CT for evaluating the PD-L1 status in PDAC and to elucidate its rationality by integrated analyses. METHODS: For bioinformatics analysis, WGCNA, GSEA and TIMER were applied to analyse the pathways and hub genes associated with PD-L1 and glucose uptake. 18F-FDG uptake assay was used to determine the glucose uptake rate of PDAC cells in vitro. Related genes expression were verified by RT-PCR and western blot. A retrospective analysis was performed on 47 patients with PDAC who had undergone 18F-FDG PET/CT. Maximum standardised uptake values (SUVmax) were determined. The usefulness of SUVmax for evaluating PD-L1 status was determined by receiver operating characteristic (ROC) curve analysis. RESULTS: Bioinformatics analysis showed that several signalling pathways are associated with both PD-L1 expression and tumour glucose uptake, among which JAK-STAT may be an important one. By in vitro experiments, the regulatory role of PD-L1 on glucose uptake was demonstrated, and its dependency on the JAK-STAT pathway was also verified by the rescue study. The SUVmax of PD-L1-positive patients was significantly higher than PD-L1-negative in tumour cells (TCs) (6.1 ± 2.3 vs. 11.1 ± 4.2; P < 0.001), and in tumour-infiltrating immune cells (TIICs) (6.4 ± 3.2 vs. 8.4 ± 3.5; P < 0.001). In a multivariate analysis, SUVmax was significantly associated with PD-L1 expression in TCs and TIICs (P < 0.001 and P = 0.018, respectively). Using SUVmax cut-off values of 8.15 and 7.75, PD-L1 status in TCs and TIICs could be predicted with accuracies of 91.5% and 74.5%, respectively. CONCLUSION: Higher 18F-FDG uptake by PDAC is associated with elevated PD-L1 expression. JAK-STAT is an important pathway that mediates PD-L1 to promote glucose uptake in PDAC.

Structural Properties and Surface Modification Decided Pharmacokinetic Behavior and Bio-Distribution of DNA Origami Frameworks in Mice.

This study establishes and validates a series of three dimentional (3D) DNA origami frameworks (DOFs) carrying imaging probes to evaluate their pharmacokinetics and real-time bio-distribution in mice. Three typical DOFs with distinguished structural properties are subjected to mice intravenous injection to systematically investigate their in vivo behaviors. Tracing the radioisotope zirconium-89 (89 Zr) trapped at the inner space of the frameworks, positron emission tomography (PET) imaging is employed to record the real-time bio-distribution of the structures and acquire their pharmacokinetic parameters in the major metabolic organs. The 3D DOFs show different behavior compared to previous structures, with lower kidney accumulation and higher liver retention. Modifications to the structures, such as exposed ssDNA or polyethylene glycol (PEG) moieties, impact their behavior, but are structure-dependent. The 43 nm icosahedra framework among the DOFs perform the best in liver targeting, with the ssDNA extensions enhancing this tendency. The modification of triantennary N-acetylgalactosamine (GalNAc), further improves its uptake in liver cells, especially in hepatocytes over other cell types, discovered by flow cytometry analysis.

A New OATP-Mediated Hepatobiliary-Specific Mn(II)-Based MRI Contrast Agent for Hepatocellular Carcinoma in Mice: A Comparison With Gd-EOB-DTPA.

BACKGROUND: Growing concerns about the safety of gadolinium (Gd)-based contrast agents have reinforced the need for the development of Gd-free MRI contrast agents (CAs) that are effective in imaging liver tumors. PURPOSE: To evaluate the ability of Mn-BnO-TyEDTA MRI CA to detect hepatocellular carcinoma in a mouse model of implanted liver tumor. STUDY TYPE: Prospective. ANIMAL MODEL: Thirteen orthotopically implanted liver tumor mice. FIELD STRENGTH/SEQUENCE: 3.0 T/precontrast and postcontrast T1-weighted fast spoiled gradient recalled echo and T2-weighted fast recovery fast spin-echo imaging with fat suppression. ASSESSMENT: The relative enhancement ratio was calculated and statistically compared. Lesion detection in postcontrast images was analyzed by calculations of area under the curve (AUC, the increases in liver-to-tumor contrast-to-noise ratio [∆CNR] vs. time curve). Mn or Gd levels were measured in the liver and tumoral tissues by inductively coupled plasma-mass spectrometry. Tumor specimens were stained with hematoxylin and eosin (H&E) and the expression of organic anion transfer peptide (OATP)1B1 was evaluated by immunofluorescence (IF) staining and mean fluorescence intensity (MFI) was calculated. STATISTICAL TESTS: Unpaired t-test and two-tailed paired t-test. P < 0.05 was considered statistical significance. RESULTS: Mn-BnO-TyEDTA and Gd-EOB-DTPA demonstrated nearly identical enhancement patterns in the liver, tumor, and psoas muscle and no difference in lesion detection (AUC10-30, Mn  = 851 ∆CR·min, AUC10-30, Gd  = 823 ∆CR·min). A Significant higher concentration of metal (Mn or Gd) was found in the liver compared to the tumor ([Mn]liver  = 0.88 ± 0.07 µmmol/g, [Mn]tumor  = 0.49 ± 0.05 µmmol/g, [Gd]liver  = 0.65 ± 0.07 µmmol/g, [Gd]tumor  = 0.27 ± 0.04 µmmol/g). IF staining showed significantly decreased expression of OATP1B1 in the tumor core compared to the liver (MFItumor  = 5.28 ± 1.54, MFIliver  = 25.49 ± 3.41). DATA CONCLUSION: Mn-BnO-TyEDTA can provide comparable hepatobiliary tumor contrast enhancement to Gd-EOB-DTPA. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Myeloperoxidase-Sensitive Magnetic Resonance Imaging Assesses Inflammatory Activation State in Experimental Mouse Acute Gout.

BACKGROUND: A novel myeloperoxidase-activatable manganese-based (MPO-Mn) MRI probe may enable the activation state of inflammatory foci to be detected and monitored noninvasively. PURPOSE: To evaluate the inflammatory response in a mouse model of acute gout using MPO as an imaging biomarker and a potential therapeutic target. STUDY TYPE: Prospective. ANIMAL MODEL: A total of 40 male Swiss mice with monosodium urate crystals induced acute gout. FIELD STRENGTH/SEQUENCE: A 3.0 T/T1-weighted imaging with 2D fast spoiled gradient recalled echo and T2-weighted imaging with fast recovery fast spin-echo sequences. ASSESSMENT: The difference in contrast-to-noise ratio between left hind limb (lesion) and right hind limb (internal reference) (ΔCNR), and normalized signal-to-noise ratio (nSNR) on the right hind limb were calculated and compared. The expression level and activity of myeloperoxidase (MPO) were analyzed using western blotting and spectrophotometric quantitation activity assay. MPO-positive cell infiltration and lesion volume were evaluated using immunofluorescence staining and T2-weighted images, respectively. STATISTICAL TESTS: Student's t test. A P-value less than 0.05 was considered to be statistically significant. RESULTS: MPO-Mn resulted in a significantly higher ΔCNR than Gd-DTPA (22.54 ± 1.86 vs. 13.90 ± 2.22) but lower nSNR on the reference right hind limb (1.08 ± 0.07 vs. 1.21 ± 0.08). Compared to the nontreatment group, MPO-inhibition resulted in a significantly reduced contrast enhancement at the lesion (17.81 ± 1.58 vs. 22.96 ± 3.12), which was consistent with a remission of the inflammatory response, as evidenced by a substantial reduction of lesion volume (0.55 ± 0.16 mm3 /g vs. 1.14 ± 0.15 mm3 /g), myeloperoxidase expression level (0.98 ± 0.09 vs. 1.48 ± 0.19) and activity (0.75 ± 0.12 vs. 1.12 ± 0.07), and inflammatory cell recruitment. DATA CONCLUSION: MPO-Mn MRI has potential to evaluate the activation state of inflammatory foci in the experimental model of acute gout. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 1.

Machine learning-based surrogate model assisting stochastic model predictive control of urban drainage systems.

Quantifying the uncertainty of stormwater inflow is critical for improving the resilience of urban drainage systems (UDSs). However, the high computational complexity and time consumption obstruct the implementation of uncertainty-addressing methods for real-time control of UDSs. To address this issue, this study developed a machine learning-based surrogate model (MLSM) that maintains high-fidelity descriptions of drainage dynamics and meanwhile diminishes the computational complexity. With stormwater inflow and controls as inputs and system overflow as the output, MLSM is able to fast evaluate system performance, and therefore stochastic optimization becomes feasible. Thus, a real-time control strategy was built by combining MLSM with the stochastic model predictive control. This strategy used stochastic stormwater inflow scenarios as input and aimed to minimize the expected overflow under all scenarios. An ensemble of stormwater inflow scenarios was generated by assuming the forecast errors follow normal distributions. To downsize the ensemble, representative scenarios with their probabilities were selected using the simultaneous backward reduction method. The proposed control strategy was applied to a combined UDS of China. Results are as follows. (1) MLSM fit well with the original high-fidelity urban drainage model, while the computational time was reduced by 99.1%. (2) The proposed strategy consistently outperformed the classical deterministic model predictive control in both magnitude and duration dimensions of system resilience, when the consumed time compatible is with the real-time operation. It is indicated that the proposed control strategy could be used to inform the real-time operation of complex UDSs and thus enhance system resilience to uncertainty.

DNA hypomethylation activation Wnt/TCF7L2/TDRD1 pathway promotes spermatogonial stem cell formation.

Detailed analysis of the regulatory mechanism of spermatogonia stem cell (SSCs) genesis can provide a novel strategy for the application of SSCs in the fields of transgenic animal production and regenerative medicine. Previous studies in this study showed that WNT signaling can positively regulate the formation of SSCs, but the exact regulatory mechanism is not clear. Here, we predicted the target gene of the Wnt/TCF7L2 pathway, namely TDRD1, by bioinformatics analysis. Functional studies revealed that overexpression of TDRD1 during RA-induced SSCs formation in vitro significantly upregulated the expression of reproductive marker genes (Integrinß1 and Integrinα6), and further flow cytometric analysis also confirmed that the formation efficiency of SSCs was significantly increased after overexpression of TDRD1; while interference with TDRD1 showed the exact opposite result. The in vivo experiments were consistent with the results of the in vitro experiments. Interestingly, although Wnt/TCF7L2 can promote the formation of SSCs, its function must be dependent on the expression of TDRD1, which was also repeatedly demonstrated as a target gene of the Wnt/TCF7L2 signaling pathway. Mechanistically, we found a large number of CpG sites in the TDRD1 promoter, and BSP analysis also confirmed that DNA methylation modifications in the TDRD1 promoter were significantly higher in embryonic stem cells than in SSCs, and further dual-luciferase reporter system assays revealed that low DNA methylation modification levels could enhance TDRD1 promoter activity; although previous studies demonstrated that TCF7L2 could enrich in the TDRD1 promoter region, the binding of the two was dependent on low DNA methylation modification. Taken together, we confirmed that low DNA methylation mediates Wnt/TCF7L2 regulation of TDRD1 to promote the formation of SSCs, providing a basis for SSCs in improving animal productivity.

Sirtuin 5 aggravates microglia-induced neuroinflammation following ischaemic stroke by modulating the desuccinylation of Annexin-A1.

BACKGROUND: Microglia-induced excessive neuroinflammation plays a crucial role in the pathophysiology of multiple neurological diseases, such as ischaemic stroke. Controlling inflammatory responses is considered a promising therapeutic approach. Sirtuin 5 (SIRT5) mediates lysine desuccinylation, which is involved in various critical biological processes, but its role in ischaemic stroke remains poorly understood. This research systematically explored the function and potential mechanism of SIRT5 in microglia-induced neuroinflammation in ischaemic stroke. METHODS: Mice subjected to middle cerebral artery occlusion were established as the animal model, and primary cultured microglia treated with oxygen-glucose deprivation and reperfusion were established as the cell model of ischaemic stroke. SIRT5 short hairpin RNA, adenovirus and adeno-associated virus techniques were employed to modulate SIRT5 expression in microglia both in vitro and in vivo. Coimmunoprecipitation, western blot and quantitative real-time PCR assays were performed to reveal the molecular mechanism. RESULTS: In the current study, we showed that SIRT5 expression in microglia was increased in the early phase of ischaemic stroke. SIRT5 interacts with and desuccinylates Annexin A1 (ANXA1) at K166, which in turn decreases its SUMOylation level. Notably, the desuccinylation of ANXA1 blocks its membrane recruitment and extracellular secretion, resulting in the hyperactivation of microglia and excessive expression of proinflammatory cytokines and chemokines, ultimately leading to neuronal cell damage after ischaemic stroke. Further investigation showed that microglia-specific forced overexpression of SIRT5 worsened ischaemic brain injury, whereas downregulation of SIRT5 exhibited neuroprotective and cognitive-preserving effects against ischaemic brain injury, as proven by the decreased infarct area, reduced neurological deficit scores, and improved cognitive function. CONCLUSIONS: Collectively, these data identify SIRT5 as a novel regulator of microglia-induced neuroinflammation and neuronal damage after cerebral ischaemia. Interventions targeting SIRT5 expression may represent a potential therapeutic target for ischaemic stroke.

Investigation of the Transporting Behavior of Framework DNA Nano-Devices Across the Artificial Blood-Brain Barrier (BBB).

This study focused on exploring the ability of self-assembled DNA frameworks to cross the blood-brain barrier (BBB). We designed and assembled a series of DNA origami structures with equal quantity of nucleic acid materials but different morphologies and rigidities, such as barrel, soccer ball, icosahedron, and compared their transport efficiency in an in vitro BBB model. It was observed that the relatively large and soft structures could better penetrate the BBB through a lysosome irrelative transcytosis process, while the smallest and most rigid structure was blocked severally accompanied with an obvious lysosome digestion once internalized by the endothelial cells.

Enamel matrix derivative expedites osteogenic differentiation of BMSCs via Wnt/ß-catenin pathway in high glucose microenvironment.

INTRODUCTION: The influence of enamel matrix derivative (EMD) on proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was explored in high glucose (HG) microenvironment with interaction of Wnt/ß-catenin pathway. MATERIALS AND METHODS: Extraction of BMSCs from Sprague-Dawley rats, culture, and identification were manifested. The cells were treated with different concentration of EMD in HG to figure out the most available concentration for proliferation and osteogenic differentiation. Then, observation of cell growth curve and cell cycle changes, and detection of Osterix, runt-related transcription factor 2 (Runx2), COL-I, early osteogenic indexes, Calcium salt deposition, and ß-catenin protein in Wnt/ß-catenin pathway were assured. After adding Wnt/ß-catenin pathway inhibitor (XAV-939) in the cells with osteogenesis induction, detection of binding of ß-catenin to Osterix was clarified. RESULTS: Via identification BMSCs cultured in vitro was qualified. Different concentrations of EMD could accelerate cell proliferation in HG and osteogenesis induction, and 75 µg/mL EMD had the best effect. The HG augmented BMSCs proliferation and the propidium iodide index of flow cytometry cycle was elevated in HG, which were strengthened via the EMD. After BMSCs' osteogenesis induction, Osterix, Runx2, CoL-1, early osteogenic indexes, and calcium salt deposition were reduced, but elevated via EMD. ß-Catenin was the lowest in the HG, but elevated after EMD. After addition of XAV-939, reduction of ß-catenin and the downstream (Osterix and Runx2) were manifested. Detection of binding protein bands was in ß-catenin and Osterix of the HG after EMD treatment. CONCLUSION: EMD may facilitate the osteogenic differentiation of BMSCs via activating the Wnt/ß-catenin pathway in HG.

Prediction of the ferrovalley property with sizable valley splitting in Janus monolayer GdBrI.

The exploitation of two-dimensional (2D) ferrovalley materials is of great significance in promoting the development of novel information storage devices, which is garnering increasing interest nowadays. However, the currently discovered 2D ferrovalley materials are very limited, and some of them still suffer from the drawback of small valley splitting, which seriously hinders their application in valleytronics. Herein, using first-principles calculations, we predict a promising 2D ferrovalley material, Janus monolayer GdBrI, which harbors sizable valley splitting and the anomalous valley Hall effect (AVHE). Monolayer GdBrI is a stable ferromagnetic semiconductor with an easy magnetization plane and magnetic transition temperature of 264.5 K. When the magnetization orientation is toward the z direction, valley polarization with a large splitting of 120.4 meV is achieved in the valence band due to the synergetic effect between the magnetic exchange interaction and spin-orbit coupling. The valley-contrasting Berry curvature gives rise to the AVHE in the monolayer. The magnitude of valley splitting can be continuously tuned by varying the magnetization orientation, biaxial strain and perpendicular electric field. These findings offer Janus monolayer GdBrI as a potential candidate for spintronic and valleytronic applications.

The synergetic effect of an aqua ligand and metal site on the performance of single-atom catalysts in H2O2 synthesis: a density functional theory study.

Studying the effect of the coordination field on the catalytic property is critical for the rational design of outstanding electrocatalysts for H2O2 synthesis. Herein, via density functional theory (DFT) calculations and ab initio molecular dynamic (AIMD) simulations, we built an effective computational framework to identify the synergetic effect of an aqua ligand and metal ion on the 2e- ORR catalytic performance under gas condition and aqua solvent. Specifically, the screening results of 29 single-atom catalysts (SACs), TM@C6N6 (TM = transition metal), indicated that Cu@C6N6 features excellent catalytic property with thermal stability, lowest 2e- ORR overpotential (0.02 V) and high selectivity of 99.99%. Once an aqua ligand binds with the Cu site, the activity is reduced to the overpotential of 0.42 V and the selectivity decreased slightly (99.98%) due to the reduction of the adsorption strength for the reaction intermediates. A combination of geometric structures and electronic properties revealed that such changes are correlated with the charge of the Cu site. Furthermore, based on molecular orbital theory, the essence of the high catalytic property deeply lies in the effect of the moderate electron back donation bond (dyz & dxz→) between Cu and O2. This work will provide a route to better design high-performance SACs for H2O2 synthesis effectively.

Phytotoxic effects on chloroplast and UHPLC-HRMS based untargeted metabolomic responses in Allium tuberosum Rottler ex Sprengel (Chinese leek) exposed to antibiotics.

Introduction of antibiotics into agricultural fields poses serious health risks to humans. This study investigated the uptake of antibiotics, their effects on metabolic pathways, and chloroplast structure changes of Allium tuberosum exposed to norfloxacin (NFL), oxytetracycline (OTC), and tetracycline (TC). Among all the antibiotic treatments, the highest accumulation of antibiotics in roots (4.15 mg/kg) and leaves (0.29 mg/kg) was TC, while in bulbs it was NFL (5.94 mg/kg). OTC was with the lowest accumulation in roots: 0.19 mg/kg, bulbs: 0.18 mg/kg, and leaves: 0.11 mg/kg. The number of mitochondira and the number of plastoglobulli increased. The chloroplast structure was disturbed under the stress of NFL, OTC, and TC. Disturbance in the chloroplast ultrastructure leads to altered chlorophyll fluorescence variables. Simultaneously, metabolomic profiling of leaves demonstrated that NFL stress regulated more of metabolic pathways than OTC and TC. Differences in metabolic pathways among the antibiotic treatments showed that each antibiotic has different impact even under the same experimental conditions. TC and NFL have more toxic effects than OTC antibiotic. Metabolic variations induced by antibiotics stress highlighted pools of metabolites that affect the metabolic activities, chlorophyll fluorescence, ultrastructural adjustments, and stimulate defensive impact in A. tubersoum. These findings provide an insight of metabolic destabilization as well as metabolic changes in defensive mechanism and stress response of A. tuberosum to different antibiotics.

Site-Specific Radioiodination of Oligonucleotides with a Phenolic Element in a Programmable Approach.

Radioiodination of oligonucleotides provides an extra modality for nucleic acid-based theranostics with potential applications. Herein, we report the design and synthesis of a phosphoramidite embedded with a phenolic moiety and demonstrate that oligonucleotides can be readily functionalized with phenol as a precursor by general DNA synthesis. It was identified that the introduction of the precursor does not block the specificity of an aptamer, and the radioiodination is applicable to both DNA and RNA oligonucleotides in a site-specific approach with a commercial kit.

Dual effect of the coordination field and sulphuric acid on the properties of a single-atom catalyst in the electrosynthesis of H2O2.

Electrocatalytic synthesis of hydrogen peroxide (H2O2) via the two-electron oxygen reduction reaction (2e- ORR) is the ideal solution for on-site H2O2 production. Herein, we propose a new strategy for creating new 2e- ORR catalysts by introducing electron-deficient B atoms and electron-rich N atoms to regulate the coordination field of metal ions on a graphene substrate. Through the first-principles density functional theory (DFT) calculations, NiN2B2-h was screened out as it had a low overpotential (0.12 V) for 2e- ORR. The Bader charge analysis revealed that B atoms increased the charge density of Ni atoms, leading to moderate binding of O2. Furthermore, the combination of ab initio molecular dynamic (AIMD) calculations and DFT calculations in an H2SO4 environment revealed a new reaction mechanism of H2O2 synthesis, involving proton-transfer between activated O2 and HSO4-. Moreover, the rate-determining step (0.63 eV) of H2O2 desorption in the presence of H2SO4 was different from that of OOH* protonation (0.45 eV) under the gas phase. This difference is attributed to the hydrogen-bond network in the acid solution.

Encapsulated Polyethyleneimine Enables Synchronous Nanostructure Construction and In Situ Functionalization of Nanofiltration Membranes.

Highly permselective nanostructured membranes are desirable for the energy-efficient molecular sieving on the subnanometer scale. The nanostructure construction and charge functionalization of the membranes are generally carried out step by step through the conventional layer-by-layer coating strategy, which inevitably brings about a demanding contradiction between the permselective performance and process efficiency. For the first time, we report the concurrent construction of the well-defined molecular sieving architectures and tunable surface charges of nanofiltration membranes through precisely controlled release of the nanocapsule decorated polyethyleneimine and carbon dioxide. This novel strategy not only substantially shortens the fabrication process but also leads to impressive performance (permeance up to 37.4 L m-2 h-1 bar-1 together with a rejection 98.7% for Janus Green B-511 Da) that outperforms most state-of-art nanofiltration membranes. This study unlocks new avenues to engineer next-generation molecular sieving materials simply, precisely, and cost efficiently.