Thirst-driven hygrosensory suppression promotes water seeking in Drosophila.

Survival in animals relies on navigating environments aligned with physiological needs. In Drosophila melanogaster, antennal ionotropic receptors (IRs) sensing humidity changes govern hygrotaxis behavior. This study sheds light on the crucial role of IR8a neurons in the transition from high humidity avoidance to water-seeking behavior when the flies become thirsty. These neurons demonstrate a heightened calcium response toward high humidity stimuli in satiated flies and a reduced response in thirsty flies, modulated by fluctuating levels of the neuropeptide leucokinin, which monitors the internal water balance. Optogenetic activation of IR8a neurons in thirsty flies triggers an avoidance response similar to the moisture aversion in adequately hydrated flies. Furthermore, our study identifies IR40a neurons as associated with dry avoidance, while IR68a neurons are linked to moist attraction. The dynamic interplay among these neurons, each with opposing valences, establishes a preference for approximately 30% relative humidity in well-hydrated flies and facilitates water-seeking behavior in thirsty individuals. This research unveils the intricate interplay between sensory perception, neuronal plasticity, and internal states, providing valuable insights into the adaptive mechanisms governing hygrotaxis in Drosophila.

Integrin α5ß1 contributes to cell fusion and inflammation mediated by SARS-CoV-2 spike via RGD-independent interaction.

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infects host cells by engaging its spike (S) protein with human ACE2 receptor. Recent studies suggest the involvement of integrins in SARS-CoV-2 infection through interaction with the S protein, but the underlying mechanism is not well understood. This study investigated the role of integrin α5ß1, which recognizes the Arg-Gly-Asp (RGD) motif in its physiological ligands, in S-mediated virus entry and cell-cell fusion. Our results showed that α5ß1 does not directly contribute to S-mediated cell entry, but it enhances S-mediated cell-cell fusion in collaboration with ACE2. This effect cannot be inhibited by the putative α5ß1 inhibitor ATN-161 or the high-affinity RGD-mimetic inhibitor MK-0429 but requires the participation of α5 cytoplasmic tail (CT). We detected a direct interaction between α5ß1 and the S protein, but this interaction does not rely on the RGD-containing receptor binding domain of the S1 subunit of the S protein. Instead, it involves the S2 subunit of the S protein and α5ß1 homo-oligomerization. Furthermore, we found that the S protein induces inflammatory responses in human endothelial cells, characterized by NF-κB activation, gasdermin D cleavage, and increased secretion of proinflammatory cytokines IL-6 and IL-1ß. These effects can be attenuated by the loss of α5 expression or inhibition of the α5 CT binding protein phosphodiesterase-4D (PDE4D), suggesting the involvement of α5 CT and PDE4D pathway. These findings provide molecular insights into the pathogenesis of SARS-CoV-2 mediated by a nonclassical RGD-independent ligand-binding and signaling function of integrin α5ß1 and suggest potential targets for antiviral treatment.

A metastable pentagonal 2D material synthesized by symmetry-driven epitaxy.

Most two-dimensional (2D) materials experimentally studied so far have hexagons as their building blocks. Only a few exceptions, such as PdSe2, are lower in energy in pentagonal phases and exhibit pentagons as building blocks. Although theory has predicted a large number of pentagonal 2D materials, many of these are metastable and their experimental realization is difficult. Here we report the successful synthesis of a metastable pentagonal 2D material, monolayer pentagonal PdTe2, by symmetry-driven epitaxy. Scanning tunnelling microscopy and complementary spectroscopy measurements are used to characterize this material, which demonstrates well-ordered low-symmetry atomic arrangements and is stabilized by lattice matching with the underlying Pd(100) substrate. Theoretical calculations, along with angle-resolved photoemission spectroscopy, reveal monolayer pentagonal PdTe2 to be a semiconductor with an indirect bandgap of 1.05 eV. Our work opens an avenue for the synthesis of pentagon-based 2D materials and gives opportunities to explore their applications such as multifunctional nanoelectronics.

Adjustable object floating states based on three-segment three-phase contact line evolution.

SignificanceAdjusting the floating states when objects float on water shows great potential for assembly, mineral flotation, nanostructured construction, and floating robot design, but the real-time regulation of floating states is challenging. Inspired by the different floating states of a falling fruit, we propose a facile strategy to transform the object between different floating states based on a three-segment three-phase contact line evolution. In addition, the potential of floating state transformation in solar-powered water evaporation, interface catalysis, and drug delivery is demonstrated. These findings provide insights into floating regulation and show great potential for floating-related applications.

Effects of the FHL2 gene on the development of subcutaneous and intramuscular adipocytes in goats.

BACKGROUND: Adipose tissue affects not only the meat quality of domestic animals, but also human health. Adipocyte differentiation is regulated by a series of regulatory genes and cyclins. Four and half-LIM protein (FHL2) is positively correlated with the hypertrophy of adipocytes and can cause symptoms such as obesity and diabetes. RESULT: In the transcriptome sequencing analysis of intramuscular adipocytes after three days of differentiation, the differentially expressed gene FHL2 was found. To further explore the biological significance of the differentially expressed gene FHL2, which was downregulated in the mature adipocytes. We revealed the function of FHL2 in adipogenesis through the acquisition and loss of function of FHL2. The results showed that the overexpression of FHL2 significantly increased the expression of adipogenic genes (PPARγ, C/EBPß) and the differentiation of intramuscular and subcutaneous adipocytes. However, silencing FHL2 significantly inhibited adipocyte differentiation. The overexpression of FHL2 increased the number of adipocytes stained with crystal violet and increased the mRNA expression of proliferation marker genes such as CCNE, PCNA, CCND and CDK2. In addition, it significantly increased the rate of EdU positive cells. In terms of apoptosis, overexpression of FHL2 significantly inhibited the expression of P53 and BAX in both intramuscular and subcutaneous adipocytes, which are involved in cell apoptosis. However, overexpression of FHL2 promoted the expression of BCL, but was rescued by the silencing of FHL2. CONCLUSIONS: In summary, FHL2 may be a positive regulator of intramuscular and subcutaneous adipocyte differentiation and proliferation, and acts as a negative regulator of intramuscular and subcutaneous adipocyte apoptosis. These findings provide a theoretical basis for the subsequent elucidation of FHL2 in adipocytes.

One-Step Electrochemical Ethylene-to-Ethylene Glycol Conversion over a Multitasking Molecular Catalyst.

Ethylene glycol is an essential commodity chemical with high demand, which is conventionally produced via thermocatalytic oxidation of ethylene with huge fossil fuel consumption and CO2 emission. The one-step electrochemical approach offers a sustainable route but suffers from reliance on noble metal catalysts, low activity, and mediocre selectivity. Herein, we report a one-step electrochemical oxidation of ethylene to ethylene glycol over an earth-abundant metal-based molecular catalyst, a cobalt phthalocyanine supported on a carbon nanotube (CoPc/CNT). The catalyst delivers ethylene glycol with 100% selectivity and 1.78 min-1 turnover frequency at room temperature and ambient pressure, more competitive than those obtained over palladium catalysts. Experimental data demonstrate that the catalyst orchestrates multiple tasks in sequence, involving electrochemical water activation to generate high-valence Co-oxo species, ethylene epoxidation to afford an ethylene oxide intermediate via oxygen transfer, and eventually ring-opening of ethylene oxide to ethylene glycol facilitated by in situ formed Lewis acid site. This work offers a great opportunity for commodity chemicals synthesis based on a one-step, earth-abundant metal-catalyzed, and renewable electricity-driven route.

Comparative Venom Multiomics Reveal the Molecular Mechanisms Driving Adaptation to Diverse Predator-Prey Ecosystems in Closely Related Sea Snakes.

Predator-prey arms races are ideal models for studying the natural selection and adaptive evolution that drive the formation of biological diversity. For venomous snakes, venom is a key bridge linking snakes with their prey, but whether and how venom evolves under the selection of diet remains unclear. Here, we focused on two closely related sea snakes, Hydrophis cyanocinctus and Hydrophis curtus, which show significant differences in prey preferences. Data-independent acquisition (DIA)-based proteomic analysis revealed different degrees of homogeneity in the venom composition of the two snakes, which was consistent with the differential phylogenetic diversity of their prey. By investigating the sequences and structures of three-finger toxins (3FTx), a predominant toxin family in elapid venom, we identified significant differences between the two sea snakes in the binding activity of 3FTx to receptors from different prey populations, which could explain the trophic specialization of H. cyanocinctus. Furthermore, we performed integrated multiomic profiling of the transcriptomes, microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and proteomes of the venom glands; constructed venom-related mRNA-miRNA-lncRNA networks; and identified a series of noncoding RNAs involved in the regulation of toxin gene expression in the two species. These findings are highly informative for elucidating the molecular basis and regulatory mechanisms that account for discrepant venom evolution in response to divergent diets in closely related snakes, providing valuable evidence for the study of coselection and coevolution in predator-prey ecosystems.

Th1 cells contribute to retinal ganglion cell loss in glaucoma in a VCAM-1-dependent manner.

Glaucoma is a complex neurodegenerative disorder characterized by the progressive loss of retinal ganglion cells (RGC) and optic nerve axons, leading to irreversible visual impairment. Despite its clinical significance, the underlying mechanisms of glaucoma pathogenesis remain poorly understood. In this study, we aimed to unravel the multifaceted nature of glaucoma by investigating the interaction between T cells and retinas. By utilizing clinical samples, murine glaucoma models, and T cell transfer models, we made several key findings. Firstly, we observed that CD4+ T cells from glaucoma patients displayed enhanced activation and a bias towards T helper (Th) 1 responses, which correlated with visual impairment. Secondly, we identified the infiltration of Th1 cells into the retina, where they targeted RGC and integrated into the pro-inflammatory glial network, contributing to progressive RGC loss. Thirdly, we discovered that circulating Th1 cells upregulated vascular cell adhesion protein 1 (VCAM-1) on retinal microvessels, facilitating their entry into the neural retina. Lastly, we found that Th1 cells underwent functional reprogramming before reaching the retina, acquiring a phenotype associated with lymphocyte migration and neurodegenerative diseases. Our study provides novel insights into the role of peripheral CD4+ T cells in glaucoma pathogenesis, shedding light on the mechanisms underlying their infiltration into the retina and offering potential avenues for innovative therapeutic interventions in this sight-threatening disease.

Long-term outcomes of newly diagnosed POEMS syndrome patients who received first-line lenalidomide-based therapy.

Not available.

Syntaxin6 contributes to hepatocellular carcinoma tumorigenesis via enhancing STAT3 phosphorylation.

BACKGROUND: Syntaxin6 (STX6) is a SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptors) protein complex located in the trans-Golgi network and endosomes, which is closely associated with a variety of intracellular membrane transport events. STX6 has been shown to be overexpressed in a variety of human malignant tumors such as esophageal, colorectal, and renal cell carcinomas, and participates in tumorigenesis and development. METHODS: Based on clinical public database and clinical liver samples analysis, the expression of STX6 in hepatocellular carcinoma (HCC) tissues was investigated. The effects of STX6 on proliferation, migration and invasion of HCC cell in vitro and in vivo were evaluated through gain- and loss-of-function studies. We further performed RNA-seq analysis and protein interactome analysis, to further decifer the detailed mechanisms of STX6 in the regulation of the JAK-STAT pathway in HCC. RESULTS: STX6 expression was upregulated in HCC tissues and its expression was highly correlated with the high histological grade of the tumor. STX6 promoted HCC cell proliferation, migration and invasion both in vitro and in vivo. Mechanistically, STX6 mediated tumor progression depending on promoting the activation of JAK-STAT signaling pathway. Receptor for activated protein kinase C (RACK1) as an essential adaptor protein mediating STX6 regulation of JAK-STAT pathway. Specifically, STX6 interacted with RACK1 and then recruited signal transducer and activator of transcription 3 (STAT3) to form a protein-binding complex and activates STAT3 transcriptional activity. CONCLUSIONS: This study provided a novel concept that STX6 exerted oncogenic effects by activating the STAT3 signaling pathway, and STX6 might be a promising therapeutic target for HCC.

Association of Gum Treatment with Cognitive Decline and Dementia Risk among Older Adults with Periodontal Symptoms: A 12-Year Prospective Cohort Study.

INTRODUCTION: This study examines the associations of gum treatment with cognitive decline and dementia risk among older adults with periodontal symptoms in the USA. METHODS: A cohort of 866 adults aged ≥50 with periodontal symptoms was recruited for the 2008 Health and Retirement Study "Dental Health Experimental Module" and followed until 2020. Cognitive function was assessed with the Telephone Interview for Cognitive Status (TICS). Dementia status was ascertained with the Langa-Weir algorithm based on TICS scores and proxy assessments. Linear mixed-effects model and multivariable Cox regression models were utilized to analyze the associations of gum treatment with cognitive decline and the risk of dementia, respectively. RESULTS: Of 866 participants (mean age 67.7, 61.4% women), 105 (12.1%) developed dementia with a median follow-up of 9 (IQR, 6-10) years. The dementia incidence rates were lower in the group with gum treatment (7.4 vs. 12.9 per 1,000 person-years). Compared with participants who did not have gum treatment, those with gum treatment experienced a decline in TICS score that was on average 0.025 (95% CI, 0.005-0.044) points less per year and a 38% lower incidence of dementia (hazard ratio, 0.62; 95% CI, 0.41-0.93). These associations were consistent across participants with a different severity of periodontal symptoms and sociodemographic characteristics (age, sex, race, ethnicity, and education) except for income levels. CONCLUSION: Prompt gum treatment for older adults with periodontal symptoms may be beneficial for their cognitive health.

Cost-Effective and Scalable Solar Interface Evaporators Derived from Industry Waste for Efficient Solar Steam Generation.

Interfacial solar steam generation for sustainable and eco-friendly desalination and wastewater treatment has attracted much attention. However, costly raw materials and complex preparation processes pose constant challenges to its wide promotion. Herein, a novel, cost-effective, and scalable strategy is presented for preparing solar interface evaporators using industrial waste as a raw material. Modified polyethylene foam evaporators (M-EPEs) are simply prepared by drilling and then hydrophilic modification of industrial waste (EPE-1). M-EPEs not only retain the strong mechanical properties and thermal insulating properties (0.047 W·m-1·K-1) of EPE-1 but also exhibit superhydrophilicity and strong light absorption (over 90%). M-EPEs achieve a high evaporation rate of 1.497 kg·m-2·h-1 and photothermal efficiency of up to 93.8% under 1 kW·m-2 solar illumination. Moreover, it has excellent stability and salt tolerance. Our work addresses the environmental issues of recycling polyethylene waste and provides a facile and efficient strategy for designing low-cost, large-scale solar interface evaporators for desalination.

Conjugated Microporous Polymer Aerogels Encapsulated within Hydroxyapatite Nanowires Exhibit Good Thermal Insulation and Flame-Retardant Properties.

Aerogels have been widely studied in the field of thermal insulation. Herein, we reported a kind of conjugated micropolymer (CMP) aerogel synthesized by 1,3,5-triethynylbenzene and 2-amino-3,5-dibromopyridine. To enhance the flame-retardant property, we composited hydroxyapatite (HAP) nanowires with a CMP aerogel. Transmission electron microscopy (TEM) analysis revealed that HAP nanowires were encapsulated within nanosized CMP tubes. In addition, the thermal conductivity of HAP2-NCMP aerogel was 0.0251 W m-1 K-1, which possesses good thermal insulation property. In the micro-combustion calorimeter (MCC) test, compared with pure NCMP, the peak heat release rate (pHRR) of HAP2-NCMP decreased from 39.3 to 30.82 W g-1, approximately 21.6% lower. Furthermore, with the increased addition of hydroxyapatite in the HAP-NCMP composite, the pHRR of HAP3-NCMP decreased by about 37.4%. Besides, NCMP possesses good mechanical properties, with a compressive strength of 117.3 kPa at a strain level of 60%. These findings suggest promising application potential for HAP-NCMP in energy-saving and flame-retardant applications.

Thalassotalea psychrophila sp. nov., Thalassotalea nanhaiensis sp. nov. and Thalassotalea fonticola sp. nov., three psychrophilic bacteria isolated from deep-sea sediment.

Three psychrophilic bacteria, designated as strains SQ149T, SQ345T, and S1-1T, were isolated from deep-sea sediment from the South China Sea. All three strains were the most closely related to Thalassotalea atypica RZG4-3-1T based on the 16S rRNA gene sequence analysis (similarity ranged from 96.45 to 96.67 %). Phylogenetic analysis based on the 16S rRNA gene and core-genome sequences showed that three strains formed a cluster within the genus Thalassotalea. The average amino acid identity, average nucleotide identity, and digital DNA-DNA hybridization values among the three strains and closest Thalassotalea species were far below the cut-off value recommended for delineating species, indicating they each represented a novel species. All three strains were Gram-stain-negative, rod-shaped, and contained summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) as the predominant fatty acid, Q-8 as the major respiratory quinone, and phosphatidylethanolamine and phosphatidylglycerol as predominant polar lipids. Based on the genomic, phylogenetic, and phenotypic characterizations, each strain is considered to represent a novel species within the genus Thalassotalea, for which the names Thalassotalea psychrophila sp. nov. (type strain SQ149T=MCCC 1K04231T=JCM 33807T), Thalassotalea nanhaiensis sp. nov. (type strain SQ345T=MCCC 1K04232T=JCM 33808T), and Thalassotalea fonticola sp. nov. (type strain S1-1T=MCCC 1K06879T=JCM 34824T) are proposed.

Comparison of Outcomes between Stent Retriever Combined with Contact Aspiration and Contact Aspiration Alone in Patients without Hyperdense Artery Sign/Susceptibility Vessel Sign.

PURPOSE: To examine the relationship between hyperdense artery sign (HAS)/susceptibility vessel sign (SVS) and thrombus composition and evaluate the effect of HAS/SVS status on the association between first-line thrombectomy techniques and outcomes in patients with acute anterior circulation large vessel occlusion (LVO). MATERIALS AND METHODS: From January 2018 to June 2021, 103 consecutive patients with acute anterior circulation LVO (75 [63.1%] men; median age, 66 years) who underwent thrombectomy and for whom the removed clot was available for histological analyses were retrospectively reviewed. The presence of HAS and SVS was assessed on unenhanced computed tomography (CT) and susceptibility-weighted imaging, respectively. Association of first-line thrombectomy techniques (stent retriever [SR] combined with contact aspiration [CA] vs CA alone) with outcomes was assessed according to HAS/SVS status. RESULTS: Among the included patients, 55 (53.4%) were HAS/SVS-negative, and 69 (67.0%) underwent first-line SR + CA. Higher relative densities of fibrin/platelets (0.56 vs 0.51; P < .001) and lower relative densities of erythrocytes (0.32 vs 0.42; P < .001) were observed in HAS/SVS-negative patients compared with HAS/SVS-positive patients. First-line SR + CA was associated with reduced odds of distal embolization (adjusted odds ratio, 0.18; 95% CI, 0.04-0.83; P = .027) and a more favorable 90-day functional outcome (adjusted odds ratio, 5.29; 95% CI, 1.06-26.34; P = .042) in HAS/SVS-negative patients and a longer recanalization time (53 vs 25 minutes; P = .025) and higher risk of subarachnoid hemorrhage (24.2% vs 0%; P = .044) in HAS/SVS-positive patients. CONCLUSIONS: Absence of HAS/SVS may indicate a higher density of fibrin/platelets in the thrombus, and first-line SR + CA yielded superior functional outcomes than CA alone in patients with acute LVO without HAS/SVS.

Design, synthesis, and biological evaluation of novel 8-substituted quercetin derivatives targeting the ß­catenin/B-cell lymphoma 9 interaction.

The ß-catenin/B-cell lymphoma 9 (BCL9) protein-protein interaction (PPI) is a potential target for aberrantly active Wnt/ß-catenin signaling which actively participates in initiating and progressing of many cancers. Herein, we discovered novel 8-substituted quercetin derivatives with potential inhibitory activities targeting ß-catenin/BCL9 PPI. Among all the derivatives, compound B4 displayed the most promising PPI inhibitory activity with an IC50 value of 2.25 µM in a competitive fluorescence polarization assay and a KD value of 1.44 µM for the ß-catenin protein. Furthermore, B4 selectively inhibited the growth of colorectal cancer (CRC) cells, suppressed the transactivation of Wnt signaling, and downregulated the expression of oncogenic Wnt target gene. Especially, B4 showed potent anti-CRC activity in vivo with the tumor growth inhibition (TGI) of 75.99 % and regulated the tumor immune microenvironment.

A Robust Adenine-Based Microporous Metal-Organic Framework with Hydrophobic Alkyl Groups and Abundant Lewis Basic Sites for CO2/N2 Separation.

The development of a chemically robust metal-organic framework (MOF) with appropriate pore nanospace for efficient CO2 capture and separation from flue gas under humid conditions is sought after. Herein, an adenine-based microporous MOF, Cu-AD-SA, bearing abundant Lewis basic sites and alkyl groups has been utilized to capture and separate CO2 from CO2/N2 gas mixtures. The introduction of alkyl groups enable Cu-AD-SA with high chemical stability. The confined pore nanospace involving small pore size and functionalized pore surface decorated by Lewis basic amino and alkyl groups bestows the framework with stronger CO2 affinity versus N2, thus resulting in a high CO2/N2 separation performance even at high operating temperature (323 K) and humidity (80%), as evidenced by breakthrough experiments. Moreover, molecular modeling studies were implemented to establish the adsorption mechanism, in which the ditopic aliphatic carboxylic acids and adenine linkers collaboratively play a vital role in the separation of CO2/N2 gas mixtures via C-H···OCO2, CCO2···O, CCO2···N, and CCO2···π interactions.

Unveiling the Presence of Short- and Medium-Chain Chlorinated Paraffins in the Hadal Trenches of the Western Pacific Ocean.

This study delves into the unexplored distribution and accumulation of chlorinated paraffins (CPs), pervasive industrial contaminants used as flame retardants and plasticizers, within the hadal trenches, some of Earth's most isolated marine ecosystems. Analysis of sediments from the Mussau (MS) and Mariana trench (MT) reveals notably high total CP concentrations (∑SCCPs + ∑MCCPs) of 10,963 and 14,554 ng g-1 dw, respectively, surpassing those in a reference site in the western Pacific abyssal plain (8533 ng g-1 dw). In contrast, the New Britain Trench (NBT) exhibits the lowest concentrations (2213-5880 ng g-1 dw), where CP distribution correlates with clay content, δ13C and δ15N values, but little with total organic carbon and depth. Additionally, amphipods from these trenches display varying CP levels, with MS amphipods reaching concerning concentrations (8681-16,138 ng g-1 lw), while amphipods in the MT-1 site show the lowest (4414-5010 ng g-1 lw). These bioaccumulation trends appear to be primarily influenced by feeding behaviors (δ13C) and trophic levels (δ15N). Utilizing biota-sediment accumulation factor values and principal component analysis, we discern that CPs in sediment may come from surface-derived particulate organic matters, while those in amphipods may come from the above carrion. Our findings elucidate the profound impacts of the emerging pollutants on the Earth's least explored marine ecosystems.

Dietary patterns and periodontitis: A systematic review.

The systematic review aimed to investigate the associations between index-based dietary patterns and the risk and severity of periodontitis. Four public databases were searched for relevant published articles. Two independent researchers conducted the study selection, quality assessment, and data extraction. Methodological quality of the selected studies was evaluated using Joanna Briggs Institute Checklists. The review was registered with PROSPERO (CRD42023395049). Twenty-five studies were eligible for this review, including 23 cross-sectional studies and two prospective cohort studies. The most utilized dietary indices were the Healthy Eating Index (HEI), the Mediterranean Diet Score (MDS), and the Dietary Inflammatory Index (DII). The results indicated a positive association between higher diet quality (i.e., higher HEI and MDSs and lower DII scores) and healthier periodontal status. Subgroup meta-analysis for four studies utilizing HEI and CDC/AAP case definition indicates the protective effect of higher HEI scores on the risk of periodontitis (OR [95% CI] = 0.77[0.68, 0.88]) with statistical significance (Z = 3.91 [p < 0.0001]). Dietary assessment was conducted by validated food frequency questionnaires (FFQ) in 52% of the studies and 24-h dietary recalls in 36% of the studies. One study utilized a validated 15-item questionnaire to measure patients' adherence to the Mediterranean Diet (QueMD). The quality assessment showed that all studies were of high quality. High HEI and MDSs and low DII scores were associated with a low risk of periodontitis and better periodontal conditions. The standardized and repeatable diet guidelines might be provided for preventing periodontitis. Future prospective studies and clinical trials are needed to confirm this causal association.

Theoretical investigations into the bonding and separation properties of non-rigid, partially rigid, and rigid ligands derived from Et-Tol-PTA with trivalent lanthanides and actinides.

The separation of trivalent actinide elements from lanthanide elements represents one of the most formidable challenges within the context of nuclear waste partitioning and transmutation (P&T) processes. Consequently, we embarked on a systematic investigation aimed at elucidating the bonding properties and thermodynamic behavior of a N-ethyl-N-tolyl-2-amide-1,10-phenanthroline (Et-Tol-PTA) ligand in conjunction with trivalent actinide and lanthanide elements. This investigation involved the utilization of various density functional theory (DFT) methods and a comparative analysis between small-core pseudopotential basis sets and all-electron basis sets. It was found that well-performing results were achieved using the PBE0 functional in both bond length and thermodynamic energy calculations, with minimal impact being exerted by the basis set on the results. Furthermore, an exploration was carried out into the bonding and thermodynamic properties of trivalent actinides and lanthanides with ligands derived from Et-Tol-PTA, encompassing non-rigid (La), partially rigid (Lb, Lc), and rigid (Ld) ligands. Thermodynamically, advantages in the separation of Am(III)/Eu(III) were exhibited by Lb and Lc ligands, while excellent performance in the separation of Am(III)/Cm(III) was demonstrated by the La ligand. Analyses conducted using quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), and natural bond orbital (NBO) methodologies revealed the presence of partial covalent character in the bonds between oxygen (O) and metal (M), as well as between nitrogen (N) and metal (M), with a higher degree of covalent character being observed in O-Am and N-Am bonds compared to O-Cm/Eu and N-Cm/Eu interactions.