A Thermostable mRNA Vaccine against COVID-19.

There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.

Endothelial peroxiredoxin-4 is indispensable for blood-brain barrier integrity and long-term functional recovery after ischemic stroke.

The endothelial lining of cerebral microvessels is damaged relatively early after cerebral ischemia/reperfusion (I/R) injury and mediates blood-brain barrier (BBB) disruption, neurovascular injury, and long-term neurological deficits. I/R induces BBB leakage within 1 h due to subtle structural alterations in endothelial cells (ECs), including reorganization of the actin cytoskeleton and subcellular redistribution of junctional proteins. Herein, we show that the protein peroxiredoxin-4 (Prx4) is an endogenous protectant against endothelial dysfunction and BBB damage in a murine I/R model. We observed a transient upregulation of Prx4 in brain ECs 6 h after I/R in wild-type (WT) mice, whereas tamoxifen-induced, selective knockout of Prx4 from endothelial cells (eKO) mice dramatically raised vulnerability to I/R. Specifically, eKO mice displayed more BBB damage than WT mice within 1 to 24 h after I/R and worse long-term neurological deficits and focal brain atrophy by 35 d. Conversely, endothelium-targeted transgenic (eTG) mice overexpressing Prx4 were resistant to I/R-induced early BBB damage and had better long-term functional outcomes. As demonstrated in cultures of human brain endothelial cells and in animal models of I/R, Prx4 suppresses actin polymerization and stress fiber formation in brain ECs, at least in part by inhibiting phosphorylation/activation of myosin light chain. The latter cascade prevents redistribution of junctional proteins and BBB leakage under conditions of Prx4 repletion. Prx4 also tempers microvascular inflammation and infiltration of destructive neutrophils and proinflammatory macrophages into the brain parenchyma after I/R. Thus, the evidence supports an indispensable role for endothelial Prx4 in safeguarding the BBB and promoting functional recovery after I/R brain injury.

AttABseq: an attention-based deep learning prediction method for antigen-antibody binding affinity changes based on protein sequences.

The optimization of therapeutic antibodies through traditional techniques, such as candidate screening via hybridoma or phage display, is resource-intensive and time-consuming. In recent years, computational and artificial intelligence-based methods have been actively developed to accelerate and improve the development of therapeutic antibodies. In this study, we developed an end-to-end sequence-based deep learning model, termed AttABseq, for the predictions of the antigen-antibody binding affinity changes connected with antibody mutations. AttABseq is a highly efficient and generic attention-based model by utilizing diverse antigen-antibody complex sequences as the input to predict the binding affinity changes of residue mutations. The assessment on the three benchmark datasets illustrates that AttABseq is 120% more accurate than other sequence-based models in terms of the Pearson correlation coefficient between the predicted and experimental binding affinity changes. Moreover, AttABseq also either outperforms or competes favorably with the structure-based approaches. Furthermore, AttABseq consistently demonstrates robust predictive capabilities across a diverse array of conditions, underscoring its remarkable capacity for generalization across a wide spectrum of antigen-antibody complexes. It imposes no constraints on the quantity of altered residues, rendering it particularly applicable in scenarios where crystallographic structures remain unavailable. The attention-based interpretability analysis indicates that the causal effects of point mutations on antibody-antigen binding affinity changes can be visualized at the residue level, which might assist automated antibody sequence optimization. We believe that AttABseq provides a fiercely competitive answer to therapeutic antibody optimization.

25-Hydroxycholesterol Protects Host against Zika Virus Infection and Its Associated Microcephaly in a Mouse Model.

Zika virus (ZIKV) has become a public health threat due to its global transmission and link to severe congenital disorders. The host immune responses to ZIKV infection have not been fully elucidated, and effective therapeutics are not currently available. Herein, we demonstrated that cholesterol-25-hydroxylase (CH25H) was induced in response to ZIKV infection and that its enzymatic product, 25-hydroxycholesterol (25HC), was a critical mediator of host protection against ZIKV. Synthetic 25HC addition inhibited ZIKV infection in vitro by blocking viral entry, and treatment with 25HC reduced viremia and conferred protection against ZIKV in mice and rhesus macaques. 25HC suppressed ZIKV infection and reduced tissue damage in human cortical organoids and the embryonic brain of the ZIKV-induced mouse microcephaly model. Our findings highlight the protective role of CH25H during ZIKV infection and the potential use of 25HC as a natural antiviral agent to combat ZIKV infection and prevent ZIKV-associated outcomes, such as microcephaly.

Leveraging single-cell RNA sequencing to unravel the impact of aging on stroke recovery mechanisms in mice.

Aging compromises the repair and regrowth of brain vasculature and white matter during stroke recovery, but the underlying mechanisms remain elusive. To understand how aging jeopardizes brain tissue repair after stroke, we performed single-cell transcriptomic profiling of young adult and aged mouse brains at acute (3 d) and chronic (14 d) stages after ischemic injury, focusing a priori on the expression of angiogenesis- and oligodendrogenesis-related genes. We identified unique subsets of endothelial cells (ECs) and oligodendrocyte (OL) progenitors in proangiogenesis and pro-oligodendrogenesis phenotypic states 3 d after stroke in young mice. However, this early prorepair transcriptomic reprogramming was negligible in aged stroke mice, consistent with the impairment of angiogenesis and oligodendrogenesis observed during the chronic injury stages after ischemia. In the stroke brain, microglia and macrophages (MG/MΦ) may drive angiogenesis and oligodendrogenesis through a paracrine mechanism. However, this reparative cell-cell cross talk between MG/MΦ and ECs or OLs is impeded in aged brains. In support of these findings, permanent depletion of MG/MΦ via antagonism of the colony-stimulating factor 1 receptor resulted in remarkably poor neurological recovery and loss of poststroke angiogenesis and oligodendrogenesis. Finally, transplantation of MG/MΦ from young, but not aged, mouse brains into the cerebral cortices of aged stroke mice partially restored angiogenesis and oligodendrogenesis and rejuvenated sensorimotor function and spatial learning and memory. Together, these data reveal fundamental mechanisms underlying the age-related decay in brain repair and highlight MG/MΦ as effective targets for promoting stroke recovery.

An archaeal virus-encoded anti-CRISPR protein inhibits type III-B immunity by inhibiting Cas RNP complex turnover.

CRISPR-Cas systems are widespread in prokaryotes and provide adaptive immune against viral infection. Viruses encode a type of proteins called anti-CRISPR to evade the immunity. Here, we identify an archaeal virus-encoded anti-CRISPR protein, AcrIIIB2, that inhibits Type III-B immunity. We find that AcrIIIB2 inhibits Type III-B CRISPR-Cas immunity in vivo regardless of viral early or middle-/late-expressed genes to be targeted. We also demonstrate that AcrIIIB2 interacts with Cmr4α subunit, forming a complex with target RNA and Cmr-α ribonucleoprotein complex (RNP). Furtherly, we discover that AcrIIIB2 inhibits the RNase activity, ssDNase activity and cOA synthesis activity of Cmr-α RNP in vitro under a higher target RNA-to-Cmr-α RNP ratio and has no effect on Cmr-α activities at the target RNA-to-Cmr-α RNP ratio of 1. Our results suggest that once the target RNA is cleaved by Cmr-α RNP, AcrIIIB2 probably inhibits the disassociation of cleaved target RNA, therefore blocking the access of other target RNA substrates. Together, our findings highlight the multiple functions of a novel anti-CRISPR protein on inhibition of the most complicated CRISPR-Cas system targeting the genes involved in the whole life cycle of viruses.

Electrical Transport and Dynamics of Confined DNA through Highly Conductive 2D Graphene Nanochannels.

Confining DNA in nanochannels is an important approach to studying its structure and transportation dynamics. Graphene nanochannels are particularly attractive for studying DNA confinement due to their atomic flatness, precise height control, and excellent mechanical strength. Here, using femtosecond laser etching and wetting transfer, we fabricate graphene nanochannels down to less than 4.3 nm in height, with the length-to-height ratios up to 103. These channels exhibit high stability, low noise, and self-cleaning ability during the long-term ionic current recording. We report a clear linear relationship between DNA length and the residence time in the channel and further utilize this relationship to differentiate DNA fragments based on their lengths, ranging widely from 200 bps to 48.5 kbps. The graphene nanochannel presented here provides a potential platform for label-free analyses and reveals fundamental insights into the conformational dynamics of DNA and proteins in confined space.

Full Electron Delocalization across the Cluster in 1,12-bisBMes2-p-carborane Radical Anion.

Conjugation between three-dimensional (3D) carboranes and the attached substituents is commonly believed to be very weak. In this paper, we report that reducing 1,12-bis(BMes2)-p-carborane (B2pCab) with one electron gives a radical anion with a centrosymmetric semiquinoidal structure. This radical anion shows extensive electron delocalization between the two boron centers over the p-carborane bridge due to the overlap of carborane lowest unoccupied molecular orbital (LUMO) and the BMes2 LUMO. Unlike dianions of other C2B10H12 carboranes, which rearrange to a nido-form, two-electron reduction of B2pCab leads to a rearrangement into a basket-shaped intermediate.

Large Language Model-Based Natural Language Encoding Could Be All You Need for Drug Biomedical Association Prediction.

Analyzing drug-related interactions in the field of biomedicine has been a critical aspect of drug discovery and development. While various artificial intelligence (AI)-based tools have been proposed to analyze drug biomedical associations (DBAs), their feature encoding did not adequately account for crucial biomedical functions and semantic concepts, thereby still hindering their progress. Since the advent of ChatGPT by OpenAI in 2022, large language models (LLMs) have demonstrated rapid growth and significant success across various applications. Herein, LEDAP was introduced, which uniquely leveraged LLM-based biotext feature encoding for predicting drug-disease associations, drug-drug interactions, and drug-side effect associations. Benefiting from the large-scale knowledgebase pre-training, LLMs had great potential in drug development analysis owing to their holistic understanding of natural language and human topics. LEDAP illustrated its notable competitiveness in comparison with other popular DBA analysis tools. Specifically, even in simple conjunction with classical machine learning methods, LLM-based feature representations consistently enabled satisfactory performance across diverse DBA tasks like binary classification, multiclass classification, and regression. Our findings underpinned the considerable potential of LLMs in drug development research, indicating a catalyst for further progress in related fields.

Relevance of pyroptosis-associated genes in nasopharyngeal carcinoma diagnosis and subtype classification.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a highly aggressive and metastatic malignancy originating in the nasopharyngeal tissue. Pyroptosis is a relatively newly discovered, regulated form of necrotic cell death induced by inflammatory caspases that is associated with a variety of diseases. However, the role and mechanism of pyroptosis in NPC are not fully understood. METHODS: We analyzed the differential expression of pyroptosis-related genes (PRGs) between patients with and without NPC from the GSE53819 and GSE64634 datasets of the Gene Expression Omnibus (GEO) database. We mapped receptor operating characteristic profiles for these key PRGs to assess the accuracy of the genes for disease diagnosis and prediction of patient prognosis. In addition, we constructed a nomogram based on these key PRGs and carried out a decision curve analysis. The NPC patients were classified into different pyroptosis gene clusters by the consensus clustering method based on key PRGs, whereas the expression profiles of the key PRGs were analyzed by applying principal component analysis. We also analyzed the differences in key PRGs, immune cell infiltration and NPC-related genes between the clusters. Finally, we performed differential expression analysis for pyroptosis clusters and obtained differentially expressed genes (DEGs) and performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. RESULTS: We obtained 14 differentially expressed PRGs from GEO database. Based on these 14 differentially expressed PRGs, we applied least absolute shrinkage and selection operator analysis and the random forest algorithm to obtain four key PRGs (CHMP7, IL1A, TP63 and GSDMB). We completely distinguished the NPC patients into two pyroptosis gene clusters (pyroptosis clusters A and B) based on four key PRGs. Furthermore, we determined the immune cell abundance of each NPC sample, estimated the association between the four PRGs and immune cells, and determined the difference in immune cell infiltration between the two pyroptosis gene clusters. Finally, we obtained and functional enrichment analyses 259 DEGs by differential expression analysis for both pyroptosis clusters. CONCLUSIONS: PRGs are critical in the development of NPC, and our research on the pyroptosis gene cluster may help direct future NPC therapeutic approaches.

Titanium Dioxide and N-Doped Carbon Hybrid Nanofiber Modulated Ru Nanoclusters for High-Efficient Hydrogen Evolution Reaction Electrocatalyst.

The designing and fabricating highly active hydrogen evolution reaction (HER) electrocatalysts that can superior to Pt/C is extremely desirable but challenging. Herein, the fabrication of Ru/TiO2/N-doped carbon (Ru/TiO2/NC) nanofiber is reported as a novel and highly active HER electrocatalyst through electrospinning and subsequent pyrolysis treatment, in which Ru nanoclusters are dispersed into TiO2/NC hybrid nanofiber. As a novel support, experimental and theoretical calculation results reveal that TiO2/NC can more effectively accelerate water dissociation as well as optimize the adsorption strength of *H than TiO2 and NC, thus leading to a significantly enhanced HER activity, which merely requires an overpotential of 18 mV to reach 10 mA cm-2, outperforming Pt/C in an alkaline solution. The electrolytic cell composed of Ru/TiO2/NC nanofiber and NiFe LDH/NF can generate 500 and 1000 mA cm-2 at voltages of 1.631 and 1.753 V, respectively. Furthermore, the electrolytic cell also exhibits remarkable durability for at least 100 h at 200 mA cm-2 with negligible degradation in activity. The present work affords a deep insight into the influence of support on the activity of electrocatalyst and the strategy proposed in this research can also be extended to fabricate various other types of electrocatalysts for diverse electrocatalytic applications.

Analysis of the prevalence and clinical features of respiratory syncytial virus infection in a pediatric hospital in Zhejiang Province from 2019 to 2023.

The aim of this study was to investigate the epidemiological characteristics of respiratory syncytial virus (RSV) infections in children in Zhejiang from 2019 to 2023. Data from pediatric patients who visited the Children's Hospital of Zhejiang University School of Medicine for RSV infection between 2019 and 2023 were analyzed. Nasopharyngeal swabs were collected for RSV antigen detection, and relevant patient information was collected. Factors such as age were analyzed. A total of 673 094 specimens were included from 2019 to 2023, with a rate of positive specimens of 4.74% (31 929/673 094). The highest rate of positive specimens of 10.82%, was recorded in 2021, while the remaining years had a rate of approximately 3%-5%. In terms of seasonal prevalence characteristics, the rate of positive specimens in 2019, 2020, and 2022 peaked in the winter months at approximately 8% and decreased in the summer months, where the rate of positive specimens remained at approximately 0.5%. In contrast, summer is the peak period for RSV incidence in 2021 and 2023, with the rate of positive specimens being as high as 9%-12%. Based on the prevalence characteristics of gender and age, this study found that the detection rate of positive specimens was higher in boys than in girls in 2019-2023. In 2019-2022, among the different age groups, the highest rate of positive specimens was found in children aged 0 to <6 months, and it decreased with age. In 2023, the rate of positive specimens was above 8% in the 0 to <6 months, 6 to <12 months, and 1-2 years age groups, with the highest rate of positive specimens in the 1-2 years age group, and a gradual decrease in the rate of positive specimens with age for children over 3 years of age. Between 2019 and 2023, the epidemiological pattern of RSV changed. A summer peak was observed in 2021 and 2023.

Study on the epidemiological characteristics of enterovirus among pediatric patients in Hangzhou, China: A comparison between the pre-COVID-19, COVID-19 pandemic, and post-COVID-19 periods.

Nonpharmaceutical interventions (NPIs) for coronavirus disease 2019 (COVID-19) not only reduce the prevalence of this disease among children but also influence the transmission of other viruses. This retrospective study investigated the impact of NPIs on human enterovirus (HEV) infection in children diagnosed with hand, foot, and mouth disease (HFMD) or herpangina (HA) in Hangzhou, China. We collected and analyzed the laboratory results and clinical data of children diagnosed with HFMD or HA during the following periods: pre-COVID-19 (January 2019 to December 2019), the COVID-19 pandemic (January 2020 to December 2022), and post-COVID-19 (January to December 2023). A total of 41 742 specimens that met the inclusion criteria were obtained, of which 1998 (4.79%) tested positive for enterovirus. In comparison to those in the pre-COVID-19 period, which had 695 (5.63%) HEV-positive specimens, the numbers dramatically decreased to 69 (1.19%), 398 (5.12%), and 112 (1.58%) in 2020, 2021, and 2022, respectively, but significantly increased to 724 (8.27%) in 2023. Seasonal peaks of infections occurred in May, June, July, and August each year, with the total detection rate ranging from 2019 to 2023 being 9.41% in May, 22.47% in June, 28.23% in July, and 12.16% in August, respectively. The difference in the detection rates of HEV infection between males and females was statistically significant (p < 0.005), with 5.11% (1221/23 898) of males and 4.35% (777/17 844) of females testing positive, resulting in a male-to-female positive ratio of 1.57:1. Among the age groups, 11.25% (378/3360) of the children aged 3-5 years had the highest detection rate, which steadily decreased with increasing or decreasing age. The detection of HEV indicated that >95% of the viruses were other types than the previously commonly reported enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). In conclusion, NPIs for COVID-19 may be effective at reducing the transmission of HEV. However, with the relaxation of NPIs, the detection rate of HEVs increased slowly to a certain extent. Active awareness and surveillance of the epidemiological characteristics of HEV are essential for preventing, controlling, and managing the development of HFMD and HA, as well as contributing to the development of a multivalent HFMD vaccine.

Voiceprint and position information detection of non-cooperative ship with Φ-OTDR and suspended sensitized optical cable.

Target detection is significant in many fields, including oceanic security, marine ecology, etc. In this paper, phase sensitive optical time domain reflectometry (Φ-OTDR) is introduced for the non-cooperative ship detection, with large-scale diversity technology and suspended sensitized optical cable. In outfield experiments, the ship's voiceprint information is obtained in high fidelity, the ship's power spectrum is analyzed, and the over-top detection is achieved. Moreover, an array orientation method based on adaptive phase difference correction (APDC) is proposed to track the ship, suppressing the delay jitter influence of acoustic transmission underwater. This is the first time that voiceprint information of the non-cooperative ship is high-fidelity acquired and deeply analyzed with Φ-OTDR and suspended sensitized optical cable, which is conducive to the detection and identification of marine targets, and proves the potential of Φ-OTDR in hydroacoustic detection applications.

Correlation between the triglyceride-glucose index and left ventricular global longitudinal strain in patients with chronic heart failure: a cross-sectional study.

BACKGROUND: Left ventricular global longitudinal strain (GLS) holds greater diagnostic and prognostic value than left ventricular ejection fraction (LVEF) in the heart failure (HF) patients. The triglyceride-glucose (TyG) index serves as a reliable surrogate for insulin resistance (IR) and is strongly associated with several adverse cardiovascular events. However, there remains a research gap concerning the correlation between the TyG index and GLS among patients with chronic heart failure (CHF). METHOD: 427 CHF patients were included in the final analysis. Patient demographic information, along with laboratory tests such as blood glucose, lipids profiles, and echocardiographic data were collected. The TyG index was calculated as Ln [fasting triglyceride (TG) (mg/dL) × fasting plasma glucose (FPG) (mg/dL)/2]. RESULTS: Among CHF patients, GLS was notably lower in the higher TyG index group compared to the lower TyG index group. Following adjustment for confounding factors, GLS demonstrated gradual decrease with increasing TyG index, regardless of the LVEF level and CHF classification. CONCLUSION: Elevated TyG index may be independently associated with more severe clinical left ventricular dysfunction in patients with CHF.

Impacts of Left Atrial Appendage Treatments on Mitral Valve Diseases during Surgical Ablations.

Background: Left atrial appendages (LAAs) play an important role in regulating left atrial function, and much evidence supports the possibility that changes in left atrial structure may cause or worsen mitral regurgitation. This study intended to investigate the outcomes of patients with mitral regurgitation who underwent left atrial appendage closure (resection or endocardial closure) during isolated surgical ablations. Methods: Patients with mild or moderate mitral regurgitation who received isolated surgical ablations for atrial fibrillation (AF) in our center from 2013 to 2022 were referred. During follow-up, each clinical visit was composed of medical interrogation, a 24 h Holter, and echocardiographic evaluation. Death, atrial fibrillation, worsening of mitral regurgitation, and stroke were evaluated as outcomes. Freedom from outcomes whose results were adjusted by inverse probability of treatment weighting for causal effects after acquiring propensity scores. Results: A total of 456 patients were enrolled in this study. During a median follow-up of 48 months, 30 deaths and 11 cases of stroke were observed. After adjustments, no significant differences in terms of death or stroke were observed among the three groups. Patients who underwent resection or endocardial closure during surgical ablations had a higher risk of mitral regurgitation worsening during follow-up (p < 0.05). During the whole follow-up, patients who underwent left atrial appendage interventions showed significantly larger left atrial and mitral annular diameters, as well as lower tethering height than those who had left atrial appendage preserved (all p < 0.05). Conclusions: Mitral regurgitation was more likely to get worse when patients with fundamental mitral diseases underwent LAA interventions during isolated surgical AF ablations. In the absence of LAA, the dilation of the left atrium and mitral annulus may ultimately lead to worsening of regurgitation.

Outcomes of Mitral Valve Repair for Posterior Leaflet Prolapse, Anterior Leaflet Prolapse, and Bileaflet Prolapse.

Background: Mitral valve repair (MVr) is an effective treatment for degenerative mitral regurgitation (DMR).And the outcomes and repair rates for posterior leaflet prolapse (PLP), anterior leaflet prolapse (ALP), and bileaflet prolapse (BLP) vary. This study aimed to compare the outcomes of mitral valve repair for patients with PLP, ALP, and BLP. Methods: From 2010 to 2019, 1192 patients with degenerative mitral valve regurgitation underwent surgery at our hospital. And 1069 patients were identified. The average age of all patients was (54.74 ± 12.17) years old for all patients. 273 patients (25.5%) had ALP, 148 patients (13.8%) had BLP, and 648 patients (60.6%) had PLP. All patients were followed up for an average duration of 5.1 years. We compared the outcomes of patients with ALP, PLP, and BLP. Results: Patients with ALP were the youngest of the 3 groups and had the highest prevalence of atrial fibrillation. Patients with PLP had the highest prevalence of hypertension, whereas patients with BLP and ALP had larger left ventricular end-diastolic and left ventricular end-systolic diameters. ALP and BLP repairs had a longer cardiopulmonary bypass and aortic cross-clamp time.10 patients dead in-hospital, 5 patients had PLP, 3 had ALP, and 2 had BLP. The 10-year survival cumulative incidences of reoperation among ALP, BLP, and PLP repairs were not significantly different. ALP repair still had higher cumulative incidences of recurrent mitral regurgitation (MR) compared to PLP. Conclusions: The rates of long-term survival and freedom from reoperation were not significantly different among patients with ALP, BLP, and PLP. ALP repair has higher cumulative incidences of recurrent MR compared to PLP.

Distributed shape detection for an acoustic sensitive optical cable with DAS.

Acoustic sensitive optical cables (ASOCs) and their shape detection are vital in underwater acoustic monitoring, and a distributed ASOC shape detection method is demonstrated with distributed acoustic sensing (DAS) technology. The accurate three-dimensional (3D) position of each ASOC unit is obtained from DAS signals and the prior position information of auxiliary acoustic sources by using a proposed adaptive peak allocation algorithm. Preliminary work has demonstrated single-point 3D localization and distributed ASOC shape detection, and the error is 6.53 cm. To the best of our knowledge, it is the first time that distributed ASOC shape detection is achieved with DAS. This method will promote the development of ASOC applications, such as underwater target detection and towed array correction.

Borirenes and Boriranes: Development and Perspectives.

Strained compounds constitute a highly topical area of research in chemistry. Borirene and borirane both feature a BC2 three-membered ring. They can be viewed as the structural analogues of cyclopropane and cyclopropene, where a CH2 unit of the carbonaceous counterparts is replaced with BH, respectively. Indeed, this structural variation introduces numerous intriguing aspects. For instance, borirane and borirene are both Lewis acidic due to the presence of a tricoordinate borane center. In addition, borirene is 2π aromatic according to Hückel's rule. In addition to their ability to form adducts with Lewis bases and the capacity of borirenes to act as ligands in coordination with metals, both borirenes and boriranes exhibit ring-opening reactivity due to the considerable ring strain. Under specific conditions, coordinated boriranes can even cleave two BC bonds to serve as formal borylene sources (although the reaction mechanisms are quite complex). On the other hand, recent successful syntheses of benzoborienes and their carborane-based three-dimensional analogues (also referred to as carborane-fused boriranes) have introduced novel perspectives to this field. For instance, they display excellent ring-expanding reactivity, possibly attributed to the boosted ring strain arising from the fusion of borirenes with benzene and boriranes with o-carborane. Importantly, their applications as valuable "BC2 " synthons have become increasingly evident along with the newly disclosed reactivity. Additionally, the boosted Lewis acidity of carborane-fused boriranes, thanks to the potent electron-withdrawing effect of o-carborane, combined with their readiness for ring enlargement, makes them promising candidates as electron-accepting building blocks in the construction of chemically responsive luminescent materials. This review provides a summary of the synthesis and reactivity of borirene and borirane derivatives, with the aim of encouraging the design of new borierene- and borirane-based molecules and inspiring further exploration of their potential applications.

Abnormal Degraded Tapetum 1 (ADT1) is required for tapetal cell death and pollen development in rice.

The timely degradation of tapetum, the innermost somatic anther cell layer in flowering plants, is critical for pollen development. Although several genes involved in tapetum development have been characterized, the molecular mechanisms underlying tapetum degeneration remain elusive. Here, we showed that mutation in Abnormal Degraded Tapetum 1 (ADT1) resulted in overaccumulation of Reactive Oxygen Species (ROS) and abnormal anther development, causing earlier tapetum Programmed Cell Death (PCD) and pollen abortion. ADT1 encodes a nuclear membrane localized protein, which is strongly expressed in the developing microspores and tapetal cells during early anther development. Moreover, ADT1 could interact with metallothionein MT2b, which was related to ROS scavenging and cell death regulation. These findings indicate that ADT1 is required for proper timing of tapetum PCD by regulating ROS homeostasis, expanding our understanding of the regulatory network of male reproductive development in rice.