Species-specific IL-1ß is an inflammatory sensor of Seneca Valley Virus 3C Protease.

Inflammasomes play pivotal roles in inflammation by processing and promoting the secretion of IL-1ß. Caspase-1 is involved in the maturation of IL-1ß and IL-18, while human caspase-4 specifically processes IL-18. Recent structural studies of caspase-4 bound to Pro-IL-18 reveal the molecular basis of Pro-IL-18 activation by caspase-4. However, the mechanism of caspase-1 processing of pro-IL-1ß and other IL-1ß-converting enzymes remains elusive. Here, we observed that swine Pro-IL-1ß (sPro-IL-1ß) exists as an oligomeric precursor unlike monomeric human Pro-IL-1ß (hPro-IL-1ß). Interestingly, Seneca Valley Virus (SVV) 3C protease cleaves sPro-IL-1ß to produce mature IL-1ß, while it cleaves hPro-IL-1ß but does not produce mature IL-1ß in a specific manner. When the inflammasome is blocked, SVV 3C continues to activate IL-1ß through direct cleavage in porcine alveolar macrophages (PAMs). Through molecular modeling and mutagenesis studies, we discovered that the pro-domain of sPro-IL-1ß serves as an 'exosite' with its hydrophobic residues docking into a positively charged 3C protease pocket, thereby directing the substrate to the active site. The cleavage of sPro-IL-1ß generates a monomeric and active form of IL-1ß, initiating the downstream signaling. Thus, these studies provide IL-1ß is an inflammatory sensor that directly detects viral protease through an independent pathway operating in parallel with host inflammasomes.

Species-specific cleavage of cGAS by picornavirus protease 3C disrupts mitochondria DNA-mediated immune sensing.

RNA viruses cause numerous infectious diseases in humans and animals. The crosstalk between RNA viruses and the innate DNA sensing pathways attracts increasing attention. Recent studies showed that the cGAS-STING pathway plays an important role in restricting RNA viruses via mitochondria DNA (mtDNA) mediated activation. However, the mechanisms of cGAS mediated innate immune evasion by RNA viruses remain unknown. Here, we report that seneca valley virus (SVV) protease 3C disrupts mtDNA mediated innate immune sensing by cleaving porcine cGAS (pcGAS) in a species-specific manner. Mechanistically, a W/Q motif within the N-terminal domain of pcGAS is a unique cleavage site recognized by SVV 3C. Three conserved catalytic residues of SVV 3C cooperatively contribute to the cleavage of pcGAS, but not human cGAS (hcGAS) or mouse cGAS (mcGAS). Additionally, upon SVV infection and poly(dA:dT) transfection, pcGAS and SVV 3C colocalizes in the cells. Furthermore, SVV 3C disrupts pcGAS-mediated DNA binding, cGAMP synthesis and interferon induction by specifically cleaving pcGAS. This work uncovers a novel mechanism by which the viral protease cleaves the DNA sensor cGAS to evade innate immune response, suggesting a new antiviral approach against picornaviruses.

Incomplete lineage sorting and gene flow within Allium (Amayllidaceae).

The phylogeny and systematics of the genus Allium have been studied with a variety of diverse data types, including an increasing amount of molecular data. However, strong phylogenetic discordance and high levels of uncertainty have prevented the identification of a consistent phylogeny. The difficulty in establishing phylogenetic consensus and evidence for genealogical discordance make Allium a compelling test case to assess the relative contribution of incomplete lineage sorting (ILS), gene flow and gene tree estimation error on phylogenetic reconstruction. In this study, we obtained 75 transcriptomes of 38 Allium species across 10 subgenera. Whole plastid genome, single copy genes and consensus CDS were generated to estimate phylogenetic trees both using coalescence and concatenation methods. Multiple approaches including coalescence simulation, quartet sampling, reticulate network inference, sequence simulation, theta of ILS and reticulation index were carried out across the CDS gene trees to investigate the degrees of ILS, gene flow and gene tree estimation error. Afterward, a regression analysis was used to test the relative contributions of each of these forms of uncertainty to the final phylogeny. Despite extensive topological discordance among gene trees, we found a fully supported species tree that agrees with the most of well-accepted relationships and establishes monophyly of the genus Allium. We presented clear evidence for substantial ILS across the phylogeny of Allium. Further, we identified two ancient hybridization events for the formation of the second evolutionary line and subg. Butomissa as well as several introgression events between recently diverged species. Our regression analysis revealed that gene tree inference error and gene flow were the two most dominant factors explaining for the overall gene tree variation, with the difficulty in disentangling the effects of ILS and gene tree estimation error due to a positive correlation between them. Based on our efforts to mitigate the methodological errors in reconstructing trees, we believed ILS and gene flow are two principal reasons for the oft-reported phylogenetic heterogeneity of Allium. This study presents a strongly-supported and well-resolved phylogenetic backbone for the sampled Allium species, and exemplifies how to untangle heterogeneity in phylogenetic signal and reconstruct the true evolutionary history of the target taxa.

Association of metabolic syndrome severity with frailty progression among Chinese middle and old-aged adults: a longitudinal study.

BACKGROUND: The binary diagnosis of Metabolic Syndrome(MetS) fails to accurately evaluate its severity, and the association between MetS severity and frailty progression remains inadequately elucidated. This study aims to clarify the relationship between the severity of MetS and the progression of frailty among the middle-aged and elderly population in China. METHOD: Participants from the 2011-2018 China Health and Retirement Longitudinal Study(CHARLS) were included for a longitudinal analysis. The study employs a frailty index(FI) based on 32 health deficits to diagnose frailty and to assess FI trajectories. An age-sex-ethnicity-specific MetS scoring model (MetS score) was used to assess metabolic syndrome severity in Chinese adults. The Cumulative MetS score from 2012 to 2015 was calculated using the formula: (MetS score in wave 1 + MetS score in wave 3) / 2 × time(2015 - 2012). The association between MetS score, Cumulative MetS score, and the risk and trajectory of frailty were evaluated using Cox regression/logistic regression, and linear mixed models. Restricted Cubic Splines(RCS) models were utilized to detect potential non-linear associations. RESULTS: A higher MetS score was significantly associated with an increased risk of frailty(HR per 1 SD increase = 1.205; 95%CI: 1.14 to 1.273) and an accelerated FI trajectory(ß per 1 SD increase = 0.113 per year; 95%CI: 0.075 to 0.15 per year). Evaluating changes in MetS score using a Cumulative MetS score indicated that each 1 SD increase in the Cumulative MetS score increased the risk of frailty by 22.2%(OR = 1.222; 95%CI: 1.133 to 1.319) and accelerated the rate of increase in FI(ß = 0.098 per year; 95%CI: 0.058 to 0.138 per year). RCS model results demonstrated a dose-response curve relationship between MetS score and Cumulative MetS score with frailty risk. Stratified analysis showed consistency across subgroups. The interaction results indicate that in males and individuals under aged 60, MetS score may accelerate the increase in FI, a finding consistent across both models. CONCLUSIONS: Our findings underscore the positive correlation between the severity of MetS and frailty progression in the middle-aged and elderly, highlighting the urgent need for early identification of MetS and targeted interventions to reduce the risk of frailty.

Sustainable Cr(VI) reduction in a membrane-less TPBC-MFC driven by solid watermelon rind.

Sustainable Cr(VI) reduction by microbial fuel cell (MFC) is a major challenge due to the electrode passivation and available electron donors. In this study, the chromate removal across a period of more than three months in a membrane-less TPBC-MFC with solid watermelon rind (SWMR) as electron donors was investigated. The TPBC benefited the Cr(VI) reduction and voltage output owing to the enhanced mass transfer. The average Cr(VI) removal efficiency (RE) of 97%, effluent COD of 80 mg/L and voltage output of 130 mV were achieved during the long-term operation on the TPBC-MFC. The SEM-EDS analysis showed that all biofilms were predominated by rod- and coccus-shaped bacteria and the Cr(VI) reduction was mainly carried out by the S-cathode. The XPS, XRD and FT-IR analysis revealed that the major product of cathodic Cr(VI) reduction was a Cr(III) precipitate in the form of Cr(OH)3. Microbial community structure disclosed that fermentation microorganisms (e.g. Anaeroarcus) and electroactive bacteria (e.g. Porphyromonadaceae) jointly responsible for SWMR degradation and electricity generation were dominant at the anode, while the chromate-associated microorganisms (e.g. Comamonadaceae and Cloacibacterium) dominated at the cathode. The biofilms adsorbing Cr(OH)3 precipitates fell off from the cathode periodically to avoid the passivation. Overall, our study suggests a really sustainable approach with which a goal of simultaneously reusing watermelon rind, reducing Cr(VI) and producing electricity was attained perfectly.

Plant-Derived Caffeic Acid and Its Derivatives: An Overview of Their NMR Data and Biosynthetic Pathways.

In recent years, caffeic acid and its derivatives have received increasing attention due to their obvious physiological activities and wide distribution in nature. In this paper, to clarify the status of research on plant-derived caffeic acid and its derivatives, nuclear magnetic resonance spectroscopy data and possible biosynthetic pathways of these compounds were collected from scientific databases (SciFinder, PubMed and China Knowledge). According to different types of substituents, 17 caffeic acid and its derivatives can be divided into the following classes: caffeoyl ester derivatives, caffeyltartaric acid, caffeic acid amide derivatives, caffeoyl shikimic acid, caffeoyl quinic acid, caffeoyl danshens and caffeoyl glycoside. Generalization of their 13C-NMR and 1H-NMR data revealed that acylation with caffeic acid to form esters involves acylation shifts, which increase the chemical shift values of the corresponding carbons and decrease the chemical shift values of the corresponding carbons of caffeoyl. Once the hydroxyl group is ester, the hydrogen signal connected to the same carbon shifts to the low field (1.1~1.6). The biosynthetic pathways were summarized, and it was found that caffeic acid and its derivatives are first synthesized in plants through the shikimic acid pathway, in which phenylalanine is deaminated to cinnamic acid and then transformed into caffeic acid and its derivatives. The purpose of this review is to provide a reference for further research on the rapid structural identification and biofabrication of caffeic acid and its derivatives.

Organophosphorus flame retardants in the Qiantang River of China: occurrence, source and ecological risk assessment.

In recent years, the prevalence and danger of organophosphorus flame retardants (OPFRs) have drawn attention from all around the world. This study examined twenty-five OPFRs observed in water and sediment samples from the Qiantang River in eastern China, as well as their occurrence, spatial distribution, possible origins, and ecological hazards. All the 25 OPFRs were detected in water and sediment samples. The levels of Σ25OPFRs in water and sediment were 35.5-192 ng/L and 8.84-48.5 ng/g dw, respectively. Chlorinated OPFRs were the main contributions in water, whereas alkyl-OPFRs were the most common congeners found in sediment. Spatial analysis revealed that sample locations in neighboring cities had somewhat higher water concentrations of OPFRs. Slowing down the river current and making the reservoir the main sink of OPFRs, the dam can prevent OPFRs from moving via the Qiantang River. Positive matrix factorization indicated that plasticizer in polyvinyl chloride, polyester resins, and polyurethane foam made the greatest contributions in water, whereas polyurethane foam and textile were the predominant source in sediment. Analysis of sediment-water exchange of OPFRs showed that twelve OPFRs in sediments can re-enter into the water body. The risk quotients showed the ecological risk was low to medium, but trixylyl phosphate exposures posed high ecological risk to aquatic organisms.

Perfluorooctane sulfonate promotes the migration of colorectal cancer cells by inducing epithelial-mesenchymal transition.

The potential association between colorectal cancer (CRC) and environmental pollutants is worrisome. Previous studies have found that some perfluoroalkyl acids, including perfluorooctane sulfonate (PFOS), induced colorectal tumors in experimental animals and promoted the migration of and invasion by CRC cells in vitro, but the underlying mechanism is unclear. Here, we investigated the effects of PFOS on the proliferation and migration of CRC cells and the potential mechanisms involving activating the PI3K/Akt-NF-κB signal pathway and epithelial-mesenchymal transition (EMT). It was found that PFOS promoted the growth and migration of HCT116 cells at non-cytotoxic concentrations and increased the mRNA expression of the migration-related angiogenic cytokines vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). In a mechanistic investigation, the up-stream signal pathway PI3K/Akt-NF-κB was activated by PFOS, and the process was suppressed by LY294002 (PI3K/Akt inhibitor) and BAY11-7082 (NF-κB inhibitor) respectively, leading to less proliferation of HCT116 cells. Furthermore, matrix metalloproteinases (MMP) and EMT-related markers were up-regulated after PFOS exposure, and were also suppressed respectively by LY294002 and BAY11-7082. Moreover, the up-regulation of EMT markers was suppressed by a MMP inhibitor GM6001. Taken together, our results indicated that PFOS promotes colorectal cancer cell migration and proliferation by activating the PI3K/Akt-NF-κB signal pathway and epithelial-mesenchymal transition. This could be a potential toxicological mechanism of PFOS-induced malignant development of colorectal cancer.

Genomic divergence and introgression among three Populus species.

Genomic divergence with gene flow is very common in both plants and animals. However, divergence and gene flow are two counteracting factors during speciation. Identifying the types of genes that are likely to be introgressed and what genetic factors restrict further effective reproduction of interspecific hybrids is of great interest to biologists. We aimed to address these issues using three related tree species, Populus alba (Pa), P. tremula (Pt), and P. tremuloides (Ps), and the interspecific hybrid of the former two species, P. × canescens (Pc). We collected 105 genomes for these four poplar lineages, including 28 Pa, 38Pt, 21 Ps, and 18 Pc individuals, to reconstruct their evolutionary histories. Our coalescence-based simulations indicated that Pa diverged earliest from Ps and Pt, and asymmetrical gene flow existed between any two lineages, with especially large ancient gene flow occurring between Pa and Pt. The genomic landscape of divergence between pairs of the three species are highly heterogeneous, which may have arisen through both divergent sorting of ancient polymorphisms and ongoing gene flow. We found that extant regions of the genome with introgressed ancestry reduced genetic divergence but elevated recombination rates and accounted for 5.76 % of the total genome. Introgressed genes were functionally associated with stress resistance, including innate immune response, anti-adversity response, and programmed cell death. However, candidate genes underlying postmating barriers of Pc were homozygous and resistant to introgression due to the incompatibility of alleles between loci after hybridization and were associated with endosperm and gamete formation and disease resistance. Our study revealed genomic dynamics during speciation with gene flow and identified regions of the genome that were likely introgressed and adaptive as well as candidate loci responsible for hybrid incompatibility that resulted in the formation of postmating barriers after hybridization.

TP53 germline pathogenic variant frequency in anaplastic rhabdomyosarcoma: A Children's Oncology Group report.

Rhabdomyosarcoma (RMS) is a well-described cancer in Li-Fraumeni syndrome, resulting from germline TP53 pathogenic variants (PVs). RMS exhibiting anaplasia (anRMS) are associated with a high rate of germline TP53 PVs. This study provides updated estimates of the prevalence of TP53 germline PVs in RMS (3%) and anRMS (11%) from a large cohort (n = 239) enrolled in five Children's Oncology Group (COG) clinical trials. Although the prevalence of germline TP53 PVs in patients with anRMS in this series is much lower than previously reported, this prevalence remains elevated. Germline evaluation for TP53 PVs should be strongly considered in patients with anRMS.

Accelerated Design for High-Entropy Alloys Based on Machine Learning and Multiobjective Optimization.

High-entropy alloys (HEAs) with high hardness and high ductility can be considered as candidates for wear-resistant applications. However, designing novel HEAs with multiple desired properties using traditional alloy design methods remains challenging due to the enormous composition space. In this work, we proposed a machine-learning-based framework to design HEAs with high Vickers hardness (H) and high compressive fracture strain (D). Initially, we constructed data sets containing 172,467 data with 161 features for D and H, respectively. Four-step feature selection was performed, with the selection of 12 and 8 features for the D and H prediction models based on the optimal algorithms of the support vector machine (SVR) and light gradient boosting machine (LightGBM), respectively. The R2 of the well-trained models reached 0.76 and 0.90 for the 10-fold cross validation. Nondominated sorting genetic algorithm version II (NSGA-II) and virtual screening were employed to search for the optimal alloying compositions, and four recommended candidates were synthesized to validate our methods. Notably, the D of three candidates have shown significant improvements compared to the samples with similar H in the original data sets, with increases of 135.8, 282.4, and 194.1% respectively. Analyzing the candidates, we have recommended suitable atomic percentage ranges for elements such as Al (2-14.8 at %), Nb (4-25 at %), and Mo (3-9.9 at %) in order to design HEAs with high hardness and ductility.

The effectiveness of WeChat couple-based psychosocial support for gynaecological cancer: A randomised controlled trial.

OBJECTIVE: This study aimed to evaluate the effectiveness of an 8-week electronic couple-based psychosocial support platform (WeChat) for gynaecological cancer. DESIGN: Randomised controlled trial. SETTING: Oncology hospital in Shaanxi Province, China. PARTICIPANTS: A total of 98 dyads of women with gynaecological cancer and their intimate male partners were included. METHODS: Couple dyads were randomly allocated to either the WeChat couple-based psychosocial support or to a control group receiving eight WeChat articles on general education content related to diet and exercise. MAIN OUTCOME MEASURES: The primary outcome was sexual function assessed with the Female Sexual Function Index. The secondary outcomes of relationship satisfaction and quality of life were assessed with the Chinese version of Revised Dyadic Adjustment Scale, Functional Assessment of Cancer Therapy-General and The World Health Organization Quality of Life BREF. These outcomes were assessed before randomisation, and immediately and 3 months after the intervention. RESULTS: The study showed that the sexual function of women participants in the intervention group did not reach a significant level compared with the control group. Relationship satisfaction in the intervention programme improved significantly (adjusted mean difference 4.7, 95% confidence interval [CI] 2.0-7.4; p = 0.001) and quality of life (QoL 6.9, 95% CI 0.5-13.3; p = 0.035) 3 months after the intervention in women with gynaecological cancer. The intervention programme also showed significant positive effects on optimising relationship satisfaction (adjuste mean difference 3.0, 95% CI 0.3-5.7; p = 0.027) of male partners. CONCLUSIONS: The results provided additional knowledge and an evidence base for the application of the support programme to improve relationship satisfaction and QoL among couples living with gynaecological cancer.

Highly Stable Triangular Single-Layer 2D Assemblies: Synthesis and Their Stimuli-Responsive Elastic and Anisotropic Curling.

Synthesis of highly stable two-dimensional single-layer assemblies (SLAs) is a key challenge in supramolecular science, especially those with long-range molecular order and well-defined morphology. Here, thin (thickness <2 nm) triangular AuI -thiolate SLAs with high thermo-, solvato- and mechano- stability have been synthesized via a double-ligand co-assembly strategy. Furthermore, the SLAs show assembly-level elastic and anisotropic deformation responses to external stimuli as a result of the long-range anisotropic molecular packing, which provides SLAs with new application potentials in bio-mimic nanomechanics.

Association between genetic polymorphisms in cytochrome P450 enzymes and survivals in women with breast cancer receiving adjuvant endocrine therapy: a systematic review and meta-analysis.

Tamoxifen is commonly prescribed for preventing recurrence in patients with breast cancer. However, the responses of the patients on tamoxifen treatment are variable. Cytochrome P450 genetic variants have been reported to have a significant impact on the clinical outcomes of tamoxifen treatment but no tangible conclusion can be made up till now. The present review attempts to provide a comprehensive review on the associative relationship between genetic polymorphisms in cytochrome P450 enzymes and survival in breast cancer patients on adjuvant tamoxifen therapy. The literature search was conducted using five databases, resulting in the inclusion of 58 studies in the review. An appraisal of the reporting quality of the included studies was conducted using the assessment tool from the Effective Public Health Practice Project (EPHPP). Meta-analyses were performed on CYP2D6 studies using Review Manager 5.3 software. For other studies, descriptive analyses were performed. The results of meta-analyses demonstrated that shorter overall survival, disease-free survival and relapse-free survival were found in the patients with decreased metabolisers when compared to normal metabolisers. The findings also showed that varying and conflicting results were reported by the included studies. The possible explanations for the variable results are discussed in this review.

The genome sequence provides insights into salt tolerance of Achnatherum splendens (Gramineae), a constructive species of alkaline grassland.

Achnatherum splendens Trin. (Gramineae) is a constructive species of the arid grassland ecosystem in Northwest China and is a major forage grass. It has good tolerance of salt and drought stress in alkaline habitats. Here, we report its chromosome-level genome, determined through a combination of Illumina HiSeq sequencing, PacBio sequencing and Hi-C technology. The final assembly of the ~1.17 Gb genome sequence had a super-scaffold N50 of 40.3 Mb. A total of 57 374 protein-coding genes were annotated, of which 54 426 (94.5%) genes have functional protein annotations. Approximately 735 Mb (62.37%) of the assembly were identified as repetitive elements, and among these, LTRs (40.53%) constitute the highest proportion, having made a major contribution to the expansion of genome size in A. splendens. Phylogenetic analysis revealed that A. splendens diverged from the Brachypodium distachyon-Hordeum vulgare-Aegilops tauschii subclade around 37 million years ago (Ma) and that a clade comprising these four species diverged from the Phyllostachys edulis clade ~47 Ma. Genomic synteny indicates that A. splendens underwent an additional species-specific whole-genome duplication (WGD) 18-20 Ma, which further promoted an increase in copies of numerous saline-alkali-related gene families in the A. splendens genome. By transcriptomic analysis, we further found that many of these duplicated genes from this extra WGD exhibited distinct functional divergence in response to salt stress. This WGD, therefore, contributed to the strong resistance to salt stress and widespread arid adaptation of A. splendens.

Three-ligand Co-assembled 2D Au(I)-Thiolate Nanosheets.

Two-dimensional (2D) Au(I)-thiolate assemblies are a special type of material that can balance high structural stability and rich surface functionality, which shows promising prospects in both fundamental research and applications. Co-assembly of multiple ligands is a facile way to further enrich the surface properties and functions, and expand their application potentials. In this work, taking 3-mercaptopropionic acid (MPA), cysteine (Cys) and 1-thioglycerol (TGO) as example ligands, we studied in detail the possibility to co-assemble them into one nanosheet. Although the three ligands have significantly different controllability and pathways when self-assembling individually with Au(I), they can still be effectively co-assembled by reacting with HAuCl4 together to obtain three-ligand nanosheets with good colloidal stability. The key points for successful co-assembly are also revealed by comparing single- and three-ligand self-assembly processes, laying a solid foundation for co-assembly of even more ligands. The easy but powerful strategy for 2D materials with closely-packed and multiple tunable surface functional groups addresses the surface engineering problem for 2D materials and paves the way for their wider applications in sensing and biomaterials.

Red Light-Emitting Thermally-Activated Delayed Fluorescence of Naphthalimide-Phenoxazine Electron Donor-Acceptor Dyad: Time-Resolved Optical and Magnetic Spectroscopic Studies.

We prepared an orthogonal compact electron-donor (phenoxazine, PXZ)-acceptor (naphthalimide, NI) dyad (NI-PXZ), to study the photophysics of the thermally-activated delayed fluorescence (TADF), which has a luminescence lifetime of 16.4 ns (99.2 %)/17.0 µs (0.80 %). A weak charge transfer (CT) absorption band was observed for the dyad, indicating non-negligible electronic coupling between the donor and acceptor at the ground state. Femtosecond transient absorption spectroscopy shows a fast charge separation (CS) (ca. 2.02∼2.72 ps), the majority of the singlet CS state is short-lived, especially in polar solvents (τCR = 10.3 ps in acetonitrile, vs. 1.83 ns in toluene, 7.81 ns in n-hexane). Nanosecond transient absorption spectroscopy detects a long-lived transient species in n-hexane, which is with a mixed triplet local excited state (3 LE) and charge separated state (3 CS), the lifetime is 15.4 µs. In polar solvents, such as tetrahydrofuran and acetonitrile, a neat 3 CS state was observed, whose lifetimes are 226 ns and 142 ns, respectively. Time-resolved electron paramagnetic resonance (TREPR) spectra indicate the existence of strongly spin exchanged 3 LE/3 CT states, with the effective zero field splitting (ZFS) |D| and |E| parameters of 1484 MHz and 109 MHz, respectively, much smaller than that of the native 3 NI state (2475 and 135 MHz). It is rare but solid experimental evidence that a closely-lying 3 LE state is crucial for occurrence of TADF and this 3 LE state is an essential intermediate state to facilitate reverse intersystem crossing in TADF systems.

Loss of PPR protein Ppr2 induces ferroptosis-like cell death in Schizosaccharomyces pombe.

Ferroptosis is a form of iron- and lipid peroxidation-mediated programmed cell death that occurs widely in mammalian cells. However, this phenomenon is rarely reported in unicellular eukaryotes. Here, we address whether ferroptosis occurs in the model unicellular eukaryote Schizosaccharomyces pombe (S. pombe). Deletion of the pentatricopeptide repeat (PPR) gene ppr2 encoding as a general mitochondrial translation factor required for mitochondrial translation disrupts iron homeostasis and induces oxidative stress, resulting in loss of cell viability. The small-molecular ferroptosis inhibitors deferoxamine (DFO) and ferrostatin-1 (Fer-1) partially rescued the ppr2 deletion-induced cell death. The amount of malondialdehyde, a lipid peroxidation marker, in Δppr2 cells was higher than that in wild type. Using C11-BODIPY 581/591, an oxidation-sensitive fluorescent lipid peroxidation probe, we showed that Δppr2 cells have a large amount of lipid peroxidation compared to wild-type cells. Deletion of ferric reductase transmembrane component 1 (frp1) encoding S. pombe ferric reductase, which is required for ferric iron uptake, partially rescued the cell death of Δppr2 cells. Our results suggest that ppr2 deletion causes an imbalance in iron homeostasis and redox, leading to ferroptosis-like cell death in S. pombe.

Hantzsch Ester-Mediated Visible-Light-Induced Radical Ethoxycarbonyldifluoromethylation of Aryl Alkynes: Kinetic-Controlled Stereoselective Synthesis of Z-gem-Difluoroallyl Esters.

A kinetic-controlled photocatalyst-free visible-light-induced stereoselective synthesis of α,α-gem-difluoro-Z-allyl esters was succeeded at room temperature in moderate to excellent yields with up to Z-isomer-only stereoselectivities through a reductive radical ethoxycarbonyldifluoromethylation of terminal aryl alkynes with blue LED (465 nm)-excited Hantzsch ester. The geometry optimizations obtained by the DFT/B3LYP calculation with a standard 6-31G(d,p) basis set were also employed for the mechanism study on the formation of a key α,α-difluoroallyl ester radical intermediate, which was generated from the addition of the ethoxycarbonyldifluoromethyl radical to aryl alkyne substrates and the stabilization effect of the neighboring group. Subsequent steric hindrance-determined hydrogen generated from the Hantzsch ester radical cation led to the formation of final aryl-substituted Z-difluoroallyl esters. This methodology provided convenient access to the synthetically important Z-configured gem-difluoroallylic building blocks.

Search for ABO3 Type Ferroelectric Perovskites with Targeted Multi-Properties by Machine Learning Strategies.

Ferroelectric perovskites are one of the most promising functional materials due to the pyroelectric and piezoelectric effect. In the practical applications of ferroelectric perovskites, it is often necessary to meet the requirements of multiple properties. In this work, a multiproperties machine learning strategy was proposed to accelerate the discovery and design of new ferroelectric ABO3-type perovskites. First, a classification model was constructed with data collected from publications to distinguish ferroelectric and nonferroelectric perovskites. The classification accuracies of LOOCV and the test set are 87.29% and 86.21%, respectively. Then, two machine learning strategies, Machine-Learning Workflow and SISSO, were used to construct the regression models to predict the specific surface area (SSA), band gap (Eg), Curie temperature (Tc), and dielectric loss (tan δ) of ABO3-type perovskites. The correlation coefficients of LOOCV in the optimal models for SSA, Eg, and Tc are 0.935, 0.891, and 0.971, respectively, while the correlation coefficient of the predicted and experimental values of the SISSO model for tan δ prediction could reach 0.913. On the basis of the models, 20 ABO3 ferroelectric perovskites with three different application prospects were screened out with the required properties, which could be explained by the patterns between the important descriptors and the properties by using SHAP. Furthermore, the constructed models were developed into web servers for the researchers to accelerate the rational design and discovery of ABO3 ferroelectric perovskites with desired multiple properties.