Reconstructing complex admixture history using a hierarchical model.

Various methods have been proposed to reconstruct admixture histories by analyzing the length of ancestral chromosomal tracts, such as estimating the admixture time and number of admixture events. However, available methods do not explicitly consider the complex admixture structure, which characterizes the joining and mixing patterns of different ancestral populations during the admixture process, and instead assume a simplified one-by-one sequential admixture model. In this study, we proposed a novel approach that considers the non-sequential admixture structure to reconstruct admixture histories. Specifically, we introduced a hierarchical admixture model that incorporated four ancestral populations and developed a new method, called HierarchyMix, which uses the length of ancestral tracts and the number of ancestry switches along genomes to reconstruct the four-way admixture history. By automatically selecting the optimal admixture model using the Bayesian information criterion principles, HierarchyMix effectively estimates the corresponding admixture parameters. Simulation studies confirmed the effectiveness and robustness of HierarchyMix. We also applied HierarchyMix to Uyghurs and Kazakhs, enabling us to reconstruct the admixture histories of Central Asians. Our results highlight the importance of considering complex admixture structures and demonstrate that HierarchyMix is a useful tool for analyzing complex admixture events.

Mesophyll conductance limits photosynthesis in fluctuating light under combined drought and heat stresses.

Drought and heat stresses usually occur concomitantly in nature, with increasing frequency and intensity of both stresses expected due to climate change. The synergistic agricultural impacts of these compound climate extremes are much greater than those of the individual stresses. However, the mechanisms by which drought and heat stresses separately and concomitantly affect dynamic photosynthesis have not been thoroughly assessed. To elucidate this, we used tomato (Solanum lycopersicum) seedlings to measure dynamic photosynthesis under individual and compound stresses of drought and heat. Individual drought and heat stresses limited dynamic photosynthesis at the stages of diffusional conductance to CO2 and biochemistry, respectively. However, the primary limiting factor for photosynthesis shifted to mesophyll conductance under the compound stresses. Compared with the control, photosynthetic carbon gain in fluctuating light decreased by 38%, 73%, and 114% under the individual drought, heat, and compound stresses, respectively. Therefore, compound stresses caused a greater reduction in photosynthetic carbon gain in fluctuating light conditions than individual stress. These findings highlight the importance of mitigating the effects of compound climate extremes on crop productivity by targeting mesophyll conductance and improving dynamic photosynthesis.

Design of the Synergistic Rectifying Interfaces in Mott-Schottky Catalysts.

The functions of interfacial synergy in heterojunction catalysts are diverse and powerful, providing a route to solve many difficulties in energy conversion and organic synthesis. Among heterojunction-based catalysts, the Mott-Schottky catalysts composed of a metal-semiconductor heterojunction with predictable and designable interfacial synergy are rising stars of next-generation catalysts. We review the concept of Mott-Schottky catalysts and discuss their applications in various realms of catalysis. In particular, the design of a Mott-Schottky catalyst provides a feasible strategy to boost energy conversion and chemical synthesis processes, even allowing realization of novel catalytic functions such as enhanced redox activity, Lewis acid-base pairs, and electron donor-acceptor couples for dealing with the current problems in catalysis for energy conversion and storage. This review focuses on the synthesis, assembly, and characterization of Schottky heterojunctions for photocatalysis, electrocatalysis, and organic synthesis. The proposed design principles, including the importance of constructing stable and clean interfaces, tuning work function differences, and preparing exposable interfacial structures for designing electronic interfaces, will provide a reference for the development of all heterojunction-type catalysts, electrodes, energy conversion/storage devices, and even super absorbers, which are currently topics of interest in fields such as electrocatalysis, fuel cells, CO2 reduction, and wastewater treatment.

Metabolic Regulation-Mediated Reversion of the Tumor Immunosuppressive Microenvironment for Potentiating Cooperative Metabolic Therapy and Immunotherapy.

Tumor cells exhibit heightened glucose (Glu) consumption and increased lactic acid (LA) production, resulting in the formation of an immunosuppressive tumor microenvironment (TME) that facilitates malignant proliferation and metastasis. In this study, we meticulously engineer an antitumor nanoplatform, denoted as ZLGCR, by incorporating glucose oxidase, LA oxidase, and CpG oligodeoxynucleotide into zeolitic imidazolate framework-8 that is camouflaged with a red blood cell membrane. Significantly, ZLGCR-mediated consumption of Glu and LA not only amplifies the effectiveness of metabolic therapy but also reverses the immunosuppressive TME, thereby enhancing the therapeutic outcomes of CpG-mediated antitumor immunotherapy. It is particularly important that the synergistic effect of metabolic therapy and immunotherapy is further augmented when combined with immune checkpoint blockade therapy. Consequently, this engineered antitumor nanoplatform will achieve a cooperative tumor-suppressive outcome through the modulation of metabolism and immune responses within the TME.

A long non-coding RNA functions as a competitive endogenous RNA to modulate TaNAC018 by acting as a decoy for tae-miR6206.

Increasing evidence indicates a strong correlation between the deposition of cuticular waxes and drought tolerance. However, the precise regulatory mechanism remains elusive. Here, we conducted a comprehensive transcriptome analysis of two wheat (Triticum aestivum) near-isogenic lines, the glaucous line G-JM38 rich in cuticular waxes and the non-glaucous line NG-JM31. We identified 85,143 protein-coding mRNAs, 4,485 lncRNAs, and 1,130 miRNAs. Using the lncRNA-miRNA-mRNA network and endogenous target mimic (eTM) prediction, we discovered that lncRNA35557 acted as an eTM for the miRNA tae-miR6206, effectively preventing tae-miR6206 from cleaving the NAC transcription factor gene TaNAC018. This lncRNA-miRNA interaction led to higher transcript abundance for TaNAC018 and enhanced drought-stress tolerance. Additionally, treatment with mannitol and abscisic acid (ABA) each influenced the levels of tae-miR6206, lncRNA35557, and TaNAC018 transcript. The ectopic expression of TaNAC018 in Arabidopsis also improved tolerance toward mannitol and ABA treatment, whereas knocking down TaNAC018 transcript levels via virus-induced gene silencing in wheat rendered seedlings more sensitive to mannitol stress. Our results indicate that lncRNA35557 functions as a competing endogenous RNA to modulate TaNAC018 expression by acting as a decoy target for tae-miR6206 in glaucous wheat, suggesting that non-coding RNA has important roles in the regulatory mechanisms responsible for wheat stress tolerance.

Electrocatalytic Aromatic Alcohols Splitting to Aldehydes and H2 Gas.

Selective electrocatalytic transformation of alcohols to aldehydes offers an efficient and environmentally friendly platform for the simultaneous production of fine chemicals and pure hydrogen gas. However, traditional alcohol oxidation reactions (AORs) in aqueous electrolyte unavoidably face competitive reactions (e.g., water oxidation and overoxidations reactions) for the presence of active oxygen species from water oxidation, causing an unwanted decrease in final efficiency and selectivity. Here, we developed an integrated all-solid proton generator-transfer electrolyzer to trigger the pure alcohol splitting reaction (ASR). In this splitting process, only O-H and C-H bonds can be cleaved at the proton generator (Pt nanoparticles), thereby completely avoiding all competitive reactions involving oxygen active species to give a > 99% selectivity to aldehydes. The as-generated protons are transported to the cathode by a three-dimensional (3D) conducting network (assemblies of ionomers and carbon spheres) for efficient hydrogen production. Unlike the poor selectivity (<22%) and durability (<3 h) of a conventional AOR electrolyzer, this ASR electrolyzer could be continuously operated at a low cell voltage of 1.2 V for at least 10 days to give a high Faradaic efficiency of 80-93% for aldehyde production.

Single-cell tumor heterogeneity landscape of hepatocellular carcinoma: unraveling the pro-metastatic subtype and its interaction loop with fibroblasts.

BACKGROUND: Tumor heterogeneity presents a formidable challenge in understanding the mechanisms driving tumor progression and metastasis. The heterogeneity of hepatocellular carcinoma (HCC) in cellular level is not clear. METHODS: Integration analysis of single-cell RNA sequencing data and spatial transcriptomics data was performed. Multiple methods were applied to investigate the subtype of HCC tumor cells. The functional characteristics, translation factors, clinical implications and microenvironment associations of different subtypes of tumor cells were analyzed. The interaction of subtype and fibroblasts were analyzed. RESULTS: We established a heterogeneity landscape of HCC malignant cells by integrated 52 single-cell RNA sequencing data and 5 spatial transcriptomics data. We identified three subtypes in tumor cells, including ARG1+ metabolism subtype (Metab-subtype), TOP2A+ proliferation phenotype (Prol-phenotype), and S100A6+ pro-metastatic subtype (EMT-subtype). Enrichment analysis found that the three subtypes harbored different features, that is metabolism, proliferating, and epithelial-mesenchymal transition. Trajectory analysis revealed that both Metab-subtype and EMT-subtype originated from the Prol-phenotype. Translation factor analysis found that EMT-subtype showed exclusive activation of SMAD3 and TGF-ß signaling pathway. HCC dominated by EMT-subtype cells harbored an unfavorable prognosis and a deserted microenvironment. We uncovered a positive loop between tumor cells and fibroblasts mediated by SPP1-CD44 and CCN2/TGF-ß-TGFBR1 interaction pairs. Inhibiting CCN2 disrupted the loop, mitigated the transformation to EMT-subtype, and suppressed metastasis. CONCLUSION: By establishing a heterogeneity landscape of malignant cells, we identified a three-subtype classification in HCC. Among them, S100A6+ tumor cells play a crucial role in metastasis. Targeting the feedback loop between tumor cells and fibroblasts is a promising anti-metastatic strategy.

Electronic Effect Driven Specific and Sensitive Recognition toward GHB.

Precise detection of a trace substance that intrinsically possesses weak chemical activity and less-distinctive spatial structure is of great significance, but full of challenges, as it could not be effectively recognized via either an active covalent reaction process or multiple noncovalent interactions toward its simple structure. Here, the electronic-effect-driven recognition strategy was proposed to visually sense an illicit drug, γ-hydroxybutyric acid (GHB), which was treated as an analyte model due to its inherent simple structure. In particular, a sensing system composed of two probes substituted by the nitro (-NO2) and the hydrogen (-H), was constructed with the characteristic yellow coloring and blue fluorescence, as well as high sensitivity (0.586 ng/mL), fast response (0.2 s), and specific recognition, even in the presence of 22 interferents. In addition, a portable eyeshadow box-like sensing chip was fabricated and proven to be reliable and feasible in sensing GHB disguised in liquors for self-protection in a covert manner. Hence, this work developed an electronic-effect-driven modulation strategy of the recognition interaction between the probe and the analyte and, thus, would open up a new thought for detecting the analyte with weak activity and a simple structure, as well as propel the relevant application in real scenarios.

Controlled Synthesis of Preferential Facet-Exposed Fe-MOFs for Ultrasensitive Detection of Peroxides.

Exposing different facets on metal-organic frameworks (MOFs) is highly desirable to enhance the performance for various applications, however, exploiting a concise and effective approach to achieve facet-controlled synthesis of MOFs remains challenging. Here, by modulating the ratio of metal precursors to ligands, the facet-engineered iron-based MOFs (Fe-MOFs) exhibits enhanced catalytic activity for Fenton reaction are explored, and the mechanism of facet-dependent performance is revealed in detail. Fully exposed (101) and (100) facets on spindle-shaped Fe-MOFs enable rapid oxidation of colorless o-phenylenediamine (OPD) to colored products, thereby establishing a dual-mode platform for the detection of hydrogen peroxide (H2O2) and triacetone triperoxide (TATP). Thus, a detection limit as low as 2.06 nm is achieved, and robust selectivity against a wide range of common substances (>16 types) is obtained, which is further improved by incorporating a deep learning architecture with an SE-VGG16 network model, enabling precise differentiation of oxidizing agents from captured images. The present strategy is expected will shine light on both the rational synthesis of nanomaterials with modulated morphologies and the exploitation of high-performance trace chemical sensors.

Tumor-Selective Nano-Dispatcher Enforced Cancer Immunotherapeutic Effects via Regulating Lactate Metabolism and Activating Toll-Like Receptors.

The development of tumors relies on lactate metabolic reprogramming to facilitate their unchecked growth and evade immune surveillance. This poses a significant challenge to the efficacy of antitumor immunity. To address this, a tumor-selective nano-dispatcher, PIMDQ/Syro-RNP, to enforce the immunotherapeutic effect through regulation of lactate metabolism and activation of toll-like receptors is developed. By using the tumor-targeting properties of c-RGD, the system can effectively deliver monocarboxylate transporters 4 (MCT4) inhibitor (Syro) to inhibit lactate efflux in tumor cells, leading to decreased lactate levels in the tumor microenvironment (TME) and increased accumulation within tumor cells. The reduction of lactate in TME will reduce the nutritional support for regulatory T cells (Tregs) and promote the effector function of T cells. The accumulation of lactate in tumor cells will lead to tumor death due to cellular acidosis. In addition, it will also reduce the uptake of glucose by tumor cells, reduce nutrient plunder, and further weaken the inhibition of T cell function. Furthermore, the pH-responsive release of Toll-like receptors (TLR) 7/8 agonist IMDQ within the TME activates dendritic cells (DCs) and promotes the infiltration of T cells. These findings offer a promising approach for enhancing tumor immune response through targeted metabolic interventions.

The innovative checkpoint inhibitors of lung adenocarcinoma, cg09897064 methylation and ZBP1 expression reduction, have implications for macrophage polarization and tumor growth in lung cancer.

Lung cancer, a prevalent and aggressive disease, is characterized by recurrence and drug resistance. It is essential to comprehend the fundamental processes and discover novel therapeutic objectives for augmenting treatment results. Based on our research findings, we have identified a correlation between methylation of cg09897064 and decreased expression of ZBP1, indicating a link to unfavorable prognosis in patients with lung cancer. Furthermore, these factors play a role in macrophage polarization, with ZBP1 upregulated in M1 macrophages compared to both M0 and M2 polarized macrophages. We observed cg09897064 methylation in M2 polarization, but not in M0 and M1 polarized macrophages. ATACseq analysis revealed closed chromatin accessibility of ZBP1 in M0 polarized macrophages, while open accessibility was observed in both M1 and M2 polarized macrophages. Our findings suggest that ZBP1 is downregulated in M0 polarized macrophages due to closed chromatin accessibility and downregulated in M2 polarized macrophages due to cg09897064 methylation. Further investigations manipulating cg09897064 methylation and ZBP1 expression through overexpression plasmids and shRNAs provided evidence for their role in modulating macrophage polarization and tumor growth. ZBP1 inhibits M2 polarization and suppresses tumor growth, while cg09897064 methylation promotes M2 polarization and macrophage-induced tumor growth. In mechanism investigations, we found that cg09897064 methylation impairs CEBPA binding to the ZBP1 promoter, leading to decreased ZBP1 expression. Clinical experiments were conducted to validate the correlation between methylation at cg09897064, ZBP1 expression, and macrophage M2 polarization. Targeting these factors may hold promise as a strategy for developing innovative checkpoint inhibitors in lung cancer treatment.

Nitrate promotes the growth and the production of short-chain fatty acids and tryptophan from commensal anaerobe Veillonella dispar in the lactate-deficient environment by facilitating the catabolism of glutamate and aspartate.

Veillonella spp. are nitrate-reducing bacteria with anaerobic respiratory activity that reduce nitrate to nitrite. They are obligate anaerobic, Gram-negative cocci that ferment lactate as the main carbon source and produce short-chain fatty acids (SCFAs). Commensal Veillonella reside in the human body site where lactate level is, however, limited for Veillonella growth. In this study, nitrate was shown to promote the anaerobic growth of Veillonella in the lactate-deficient media. We aimed to investigate the underlying mechanisms and the metabolism involved in nitrate respiration. Nitrate (15 mM) was demonstrated to promote Veillonella dispar growth and viability in the tryptone-yeast extract medium containing 0.5 mM L-lactate. Metabolite and transcriptomic analyses revealed nitrate enabled V. dispar to actively utilize glutamate and aspartate from the medium and secrete tryptophan. Glutamate or aspartate was further supplemented to a medium to investigate individual catabolism during nitrate respiration. Notably, nitrate was demonstrated to elevate SCFA production in the glutamate-supplemented medium, and further increase tryptophan production in the aspartate-supplemented medium. We proposed that the increased consumption of glutamate provided reducing power for nitrate respiration and aspartate served as a substrate for fumarate formation. Both glutamate and aspartate were incorporated into the central metabolic pathways via reverse tricarboxylic acid cycle and were linked with the increased production of acetate, propionate, and tryptophan. This study provides further understanding of the promoted growth and metabolic mechanisms by commensal V. dispar utilizing nitrate and specific amino acids to adapt to the lactate-deficient environment.IMPORTANCENitrate is a pivotal ecological factor influencing microbial community and metabolism. Dietary nitrate provides health benefits including anti-diabetic and anti-hypertensive effects via microbial-derived metabolites such as nitrite. Unraveling the impacts of nitrate on the growth and metabolism of human commensal bacteria is imperative to comprehend the intricate roles of nitrate in regulating microbial metabolism, community, and human health. Veillonella are lactate-utilizing, nitrate-reducing bacteria that are frequently found in the human body site where lactate levels are low and nitrate is at millimolar levels. Here, we comprehensively described the metabolic strategies employed by V. dispar to thrive in the lactate-deficient environment using nitrate respiration and catabolism of specific amino acids. The elevated production of SCFAs and tryptophan from amino acids during nitrate respiration of V. dispar further suggested the potential roles of nitrate and Veillonella in the promotion of human health.

Absence of Barren Plateaus in Finite Local-Depth Circuits with Long-Range Entanglement.

Ground state preparation is classically intractable for general Hamiltonians. On quantum devices, shallow parametrized circuits can be effectively trained to obtain short-range entangled states under the paradigm of variational quantum eigensolver, while deep circuits are generally untrainable due to the barren plateau phenomenon. In this Letter, we give a general lower bound on the variance of circuit gradients for arbitrary quantum circuits composed of local 2-designs. Based on our unified framework, we prove the absence of barren plateaus in training finite local-depth circuits (FLDC) for the ground states of local Hamiltonians. FLDCs are allowed to be deep in the conventional circuit depth to generate long-range entangled ground states, such as topologically ordered states, but their local depths are finite, i.e., there is only a finite number of gates acting on individual qubits. This characteristic sets FLDC apart from shallow circuits: FLDC in general cannot be classically simulated to estimate local observables efficiently by existing tensor network methods in two and higher dimensions. We validate our analytical results with extensive numerical simulations and demonstrate the effectiveness of variational training using the generalized toric code model.

Entanglement Structure and Information Protection in Noisy Hybrid Quantum Circuits.

In the context of measurement-induced entanglement phase transitions, the influence of quantum noises, which are inherent in real physical systems, is of great importance and experimental relevance. In this Letter, we present a comprehensive theoretical analysis of the effects of both temporally uncorrelated and correlated quantum noises on entanglement generation and information protection. This investigation reveals that entanglement within the system follows q^{-1/3} scaling for both types of quantum noises, where q represents the noise probability. The scaling arises from the Kardar-Parisi-Zhang fluctuation with effective length scale L_{eff}∼q^{-1}. More importantly, the information protection timescales of the steady states are explored and shown to follow q^{-1/2} and q^{-2/3} scaling for temporally uncorrelated and correlated noises, respectively. The former scaling can be interpreted as a Hayden-Preskill protocol, while the latter is a direct consequence of Kardar-Parisi-Zhang fluctuations. We conduct extensive numerical simulations using stabilizer formalism to support the theoretical understanding. This Letter not only contributes to a deeper understanding of the interplay between quantum noises and measurement-induced phase transition but also provides a new perspective to understand the effects of Markovian and non-Markovian noises on quantum computation.

Strategies for the Construction of Benzobicyclo[3.2.1]octane in Natural Product Synthesis.

Benzobicyclo[3.2.1]octane is a cage-like unique motif containing a bicyclo[3.2.1]octane structure fused with at least one benzene ring. It is found in various natural products that exhibit structural complexities and important biological activities. The total synthesis of natural products possessing this challenging structure has received considerable attention, and great advances have been made in this field during the past 15 years. This review summarizes thus far achieved chemical syntheses and synthetic studies of natural compounds featuring the benzobicyclo[3.2.1]octane core. It focuses on strategic approaches constructing the bridged structure, aiming to provide a useful reference for inspiring further advancements in strategies and total syntheses of natural products with such a framework.

Discovery of Unusual Ajmaline-Macroline Type Bisindole Alkaloids from Alstonia macrophylla by Building Blocks-Based Molecular Networking.

Three unusual ajmaline-macroline type bisindole alkaloids, alsmaphylines A-C, together with their postulated biogenetic precursors, were isolated from the stem barks and leaves of Alstonia macrophylla via the building blocks-based molecular network (BBMN) strategy. Alsmaphyline A represents a rare ajmaline-macroline type bisindole alkaloid with an S-shape polycyclic ring system. Alsmaphylines B and C are two novel ajmaline-macroline type bisindole alkaloids with N-1-C-21' linkages, and the former possesses an unconventional stacked conformation due to the presence of intramolecular noncovalent interactions. The chemical structures including absolute configurations of alsmaphylines A-C were established by comprehensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray crystallography. In addition, a plausible biosynthetic pathway of these bisindole alkaloids as well as their ability to promote the protein synthesis on HT22 cells were discussed.

Managing malignant sublingual gland tumors: a single institution experience with 23 patients.

BACKGROUND: Due to the relative rarity of malignant sublingual gland tumors, diagnosing and treating them clinically pose challenges. Hence, there's a need to explore the pathological types, characteristics, treatment methods, and prognosis of primary malignant tumors of the sublingual gland to improve our understanding and management of these rare yet highly malignant conditions. METHODS: This study reviewed cases of primary malignant sublingual gland tumors, analyzing their characteristics. The treatment methods included surgical excision, with additional radiotherapy, or brachytherapy for advanced stages or positive surgical margins. The study also summarized different treatment approaches, including lymph node dissection and soft tissue reconstruction using free flaps such as the anterolateral thigh flap and forearm flap. RESULTS: We have gathered 23 cases of sublingual gland malignancies treated at the Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, from January 2013 to May 2024. The most common pathological types were adenoid cystic carcinoma and mucoepidermoid carcinoma, with rare cases of mucosa-associated lymphoid tissue (MALT) lymphoma and nonspecific salivary gland clear cell carcinoma. Early diagnosis and surgical intervention were crucial for a favorable prognosis. Marginal mandibulectomy was necessary for cases involving the mandible. Patients with positive preoperative lymph node detection required cervical lymph node dissection. Extensive tissue defects in the floor of the mouth were effectively reconstructed with free flaps to prevent oral-mandibular fistula. CONCLUSION: Surgical excision remains the preferred treatment for malignant sublingual gland tumors. Early diagnosis and comprehensive surgical management are essential for improving prognosis. The study's limitations include a small sample size and short follow-up duration, necessitating further research with larger clinical samples to confirm these findings.

Pre-electroacupuncture Ameliorates Cerebral Ischemia-reperfusion Injury by Inhibiting Microglial RhoA/pyrin/GSDMD Signaling Pathway.

Cerebral ischemia reperfusion injury is a severe neurological impairment that occurs after blood flow reconstruction in stroke, and microglia cell pyroptosis is one of its important mechanisms. Electroacupuncture has been shown to be effective in mitigating and alleviating cerebral ischemia reperfusion injury by inhibiting neuroinflammation, reducing cellular pyroptosis, and improving neurological function. In this experiment, we divided the rats into three groups, including the sham operation (Sham) group, the middle cerebral artery occlusion/reperfusion (MCAO/R) group, and the pre-electroacupuncture (EAC) group. Pre-electroacupuncture group was stimulated with electroacupuncture of a certain intensity on the Baihui (GV 20) and Dazhui (GV 14) of the rat once a day from the 7th day to the 1st day before the MCAO/R operation. The extent of cerebral infarction was detected by TTC staining. A modified Zea-Longa five-point scale scoring system was used to determine neurologic function in MCAO rats. The number of neurons and morphological changes were accessed by Nissl staining and HE staining. The cellular damage was detected by TUNEL staining. In addition, the expression levels of RhoA, pyrin, GSDMD, Caspase1, cleaved-Caspase1, Iba-1, CD206, and ROCK2 were examined by western blotting and immunofluorescence. The results found that pre-electroacupuncture significantly attenuated neurological impairment and cerebral infarction compared to the post-MCAO/R rats. In addition, pre-electroacupuncture therapy promoted polarization of microglia to the neuroprotective (M2) phenotype. In addition, pre-electroacupuncture inhibited microglia pyroptosis by inhibiting RhoA/pyrin/GSDMD signaling pathway, thereby reducing neuronal injury and increasing neuronal survival in the MCAO/R rats. Taken together, these results demonstrated that pre-acupuncture could attenuate cerebral ischemia-reperfusion injury by inhibiting microglial pyroptosis. Therefore, pre-electroacupuncture might be a potential preventive strategy for ischemic stroke patients.

Roles of Nonadiabatic Processes, Reaction Mechanism, and Selectivity in Cu-Catalyzed [2 + 2] Photocycloaddition of Norbornene and Acetone to Oxetane.

Oxetane has been extensively studied for its applications in medicinal chemistry and as a reactive intermediate in synthesis. Experiments report a Cu-catalyzed [2 + 2] photocycloaddition of acetone and norbornene to oxetane, which is proposed to deviate from the conventional Paternò-Büchi reaction. However, its mechanism at the atomic level is not clear. In this study, we used a combination of multistate complete active space second-order perturbation theory (MS-CASPT2) and density functional theory to systematically investigate the reaction mechanism and elucidate the factors contributing to the diastereomeric selectivity. Initially, the formation of the TpCu(Norb) complex is achieved by strong interaction between tris(pyrazolyl)borate Cu(I) (TpCu) and norbornene in the ground state (S0). Upon photoexcitation, TpCu(Norb) eventually decays to the T1 state, in which TpCu(Norb) attacks acetone to initiate subsequent reactions and produces final endo- or exo-oxetane products. All these reactions initially involve the C-C bond formation in the T1 state thereto leading to a ring-opening intermediate. This intermediate then undergoes a nonradiative transition to the S0 state, producing a five-membered ring intermediate, from which the C-O bond is formed, leading to the experimentally dominant exo-product. In contrast, the endo-oxetane formation requires a rearrangement process after the C-C bond is formed because of the large steric effects. As a consequence, the different reaction pathways generating exo- and endo-products exhibit large differences in the free-energy barriers, which results in a diastereomeric selectivity observed experimentally. Additionally, the nonradiative transition is found to play an important role in facilitating these reaction steps. The present computational study provides valuable mechanistic insights into Cu-catalyzed photocycloaddition reactions.

Cationic Europium-Organic Framework for Chromatographic Column Separation of Ionic Dyes and Stimuli-Responsive Chromic Properties.

A novel 3D europium-based cationic framework (Eu-CMOF) has been constructed solvothermally by employing a viologen derivative as an organic functional building unit. Notably, Eu-CMOF demonstrates its capability as a proficient aqueous-phase ion-exchange host, facilitating the remarkable rapid chromatographic column separation of new coccine and malachite green (NC3-/MG+), as well as new coccine and methylene blue (NC3-/MLB+), in mere 2 to 4 min. Adsorption thermodynamics and kinetics of anionic dyes demonstrate that Eu-CMOF exhibits a higher adsorption capacity for NC3-, as evaluated by the Langmuir model, reaching a value of 173 mg·g-1. The pseudo-second-order rate constant is determined to be 3.84 × 10-3 mg-1·g·min-1. Additionally, Eu-CMOF displays reversible photochromic and amine- and ammonia-induced vapochromic behaviors. Further mechanistic studies reveal that these chromic behaviors are primarily attributed to the generation of free viologen radical stimulated by Xe-light or electron-rich amine/ammonia. This research contributes to the development of advanced materials with applications in rapid chromatographic separation and stimuli-responsive chromic properties, showcasing the potential of Eu-CMOF as a versatile platform for practical applications.