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Understanding the excited-state dynamics of molecular photoswitches is key for advancing their design and optimizing their applications. Here, we characterize the excited-state chemistry of a recently reported oxorhodanine photoswitch through ultrafast spectroscopy and multireference quantum chemical calculations. Both Z and E forms undergo excited-state isomerization reactions on a sub-picosecond time scale to form a hot ground-state and the product isomer. The reaction is shown to proceed entirely within the singlet manifold, in sharp contrast to the rhodanine photoswitches, which react through the triplet state. The difference is ascribed to the nπ* state arising from the C═S bond in the rhodanines. The dominance of ultrafast relaxation in the singlet state is confirmed by multireference ab initio calculations which also show that the reaction coordinate involves torsion and pyramidialization. This reaction coordinate is consistent with the observed viscosity dependence. Calculations also indicate that the observed differences between ultrafast relaxation in the Z and E forms may arise from a shallow minimum on the excited-state of the latter.

Besides motor brain regions, amyotrophic lateral sclerosis (ALS) affects non-motor regions such as front temporal regions, affecting various cognitive domains. We performed a behavioral study using the attention network test (ANT) to examine two components of attention (alerting, executive condition) and two degrees of difficulty (conflict condition) in 27 patients with ALS with no reported symptoms suggestive of cognitive impairment and 26 matched control participants. Using a modified ANT that accounted for ALS-induced motor impairment by focusing on relative reaction times, we could demonstrate its feasibility even in severely paralyzed patients. Relative reaction time differences were comparable to controls, demonstrating the task's ability to correct for motor bias. When focusing on relative reaction times, in both groups we found intact executive and conflict effects. Furthermore, ALS patients had comparable task accuracies when reacting to congruent and incongruent easy targets. However, the task accuracy of ALS patients was significantly lower compared to controls when reacting to the incongruent hard target. This effect was enhanced by the interaction effect of ALS diagnosis and age. Our results suggest a significant interaction between age and ALS pathology, potentially leading to a breakdown of cognitive resources at higher levels of executive demand. We hypothesize that subclinical executive vulnerability in ALS patients becomes apparent when additional detrimental factors, such as aging, are present in patients. While we did not test co-pathologies in our cohort, co-occurring neurodegenerative or vascular processes might have contributed to this result. Our findings highlight the importance of cognitive screening for ALS patients above 60 years, even in the absence of subjective and collateral history of cognitive impairment.

High-temperature oxidation of HfB2 governs its long-term stability in extreme environments, yet the atomistic dynamics of surface oxidation remain incompletely elucidated. Herein, the oxidation process of the HfB2(0001) surface was systematically investigated by combining density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. The results show that O2 undergoes spontaneous dissociation on the Hf-terminated surface, forming a HfO2 layer that effectively suppresses further oxygen adsorption. In contrast, O2 dissociation on the B-terminated surface requires overcoming an energy barrier of 0.28 eV, and the resulting [BO3] units lead to surface structural degradation. AIMD simulations at 973 and 1673 K further demonstrate distinct reaction pathways: on the Hf-terminated surface, O atoms react exclusively with the surface Hf atoms; on the B-terminated surface, O atoms initially form B2O3 units, subsequently diffuse into the subsurface layer, and react with Hf atoms beneath the surface. This process involves reaction intermediates evolving sequentially from [HfB2O] to [Hf2B2O], then to [Hf3BO], and finally transforming into [Hf3O]. Notably, an elevated temperature accelerates oxygen diffusion and intermediate transformation, increasing the oxidation rate. These findings provide atomic-scale theoretical insights into HfB2 oxidation and establish a basis for optimizing the oxidation resistance.

Aldoximes react with CS2 in the presence of DBU and TBACl, providing access to primary thioamides. This unprecedented reaction proceeds under metal-free and mild conditions and tolerates a broad range of substrates. Its robustness has been demonstrated on the synthesis of active drug Febuxostat (gout) and an advanced intermediate in the synthesis of SRT2104 (type 2 diabetes). Computational studies, based on DFT calculations, have revealed the roles of both the base and TBACl in the reaction and have elucidated the reaction mechanism, which differs significantly from those displayed for other CS2 insertions.

Sand flies are vectors of various pathogens, primarily Leishmania and phleboviruses. The effectiveness of disease control strategies can be assessed using serological tests that measures antibodies against sand fly saliva as a marker of host exposure and a proxy biomarker of sand fly-borne pathogens transmission. Recently, we proposed novel recombinant salivary proteins to evaluate exposure of dogs to Phlebotomus tobbi and P. papatasi. The aim of this study was to test vector and host specificity of these recombinant proteins. Recombinant salivary proteins of P. papatasi (PAP-rSP32, PAP-rSP36, and PAP-rSP42) and P. tobbi (TOB-rSP10, TOB-rSP38, TOB-rSP56, TOB-rSP60) were tested in an enzyme-linked immunosorbent assay (ELISA) using sera from dogs and mice experimentally bitten by a single sand fly species as well as from naturally exposed dogs. Among the three P. papatasi recombinant proteins tested, rSP36 apyrase exhibited the highest vector species-specificity. It did not cross-react with antibodies from dogs or mice experimentally bitten by P. perniciosus, P. tobbi, P. sergenti, Sergentomyia schwetzi, Lutzomyia longipalpis, or two mosquito species (Culex pipiens molestus and C. quinquefasciatus), closely followed by rSP42 yellow-related protein. In contrast, PAP-rSP32 showed host-related species specificity, cross-reacting with murine anti-P. perniciosus antibodies, but not with canine ones. Among the four P. tobbi recombinants, rSP38 yellow-related protein was the only vector subgenus-specific antigen across all the murine sera tested, followed by rSP10 apyrase and rSP60 D7-related protein, which cross-reacted with anti-P. papatasi IgG. The other D7-related protein, rSP56, lacked sand fly-specificity as it cross-reacted with antibodies against Culex saliva. ELISA assays based on PAP-rSP36, PAP-rSP42, and TOB-rSP38 are recommended for large-scale field studies as they exhibited the highest species-specificity. These assays can provide epidemiologically relevant data that complement other surveillance and leishmaniasis control tools.

The "acyl ∼ amine" interfacial polymerization is widely studied to synthesize polyamide membranes, which, despite broad separation applications, suffer from poor acid stability. Cyanuric chloride (CC) can react with amines to form acid-stable C─N bonds, yet its third chloride atom is unreactive at room temperature, thus hindering the synthesis of selective membranes by interfacial polymerization. This work reported a pyridinium-catalyzed interfacial polymerization (PCIP) strategy to significantly improve CC's reactivity and synthesize high-performance, acid-resistant membranes. We designed a new monomer bearing triple pyridines, which were converted to positively charged pyridiniums during their interfacial polymerization with CC. These pyridiniums effectively reduce the electron density of CC rings via their electron-withdrawing capacity, and improve CC's substitution reactivity by orders of magnitude, thereby enabling the rapid (1 min) synthesis of a large-area (∼0.5 m2) membrane. The membrane is stable in 2 M H2SO4, showing one of the highest separation performances (permeance: ∼16.8 L m-2 h-1 bar-1; selectivity: ∼12.8) among previous CC-based membranes, combined with ∼4 times higher efficiency in lithium and cobalt recovery from LiCoO2 spent batteries.

A palladium-catalyzed C-H silylation reaction of alkenyl triflates has been developed, employing a norbornene analogue as a relay for C-H activation. The reaction forms C(vinyl), C(alkyl)-palladacycles as the key intermediates via norbornene analogue-relayed C-H activation. These palladacycles subsequently react with a disilane to form disilylated intermediates, which undergo a retro-Diels-Alder reaction to deliver the final products. This method offers an efficient route to Z,Z-1,4-disilylated 1,3-dienes.

Nitrite (NO2-) and nitrate (NO3-) play important roles in the global nitrogen cycle and are closely associated with human health and environmental safety, necessitating the development of sensitive and accurate detection methods. Herein, we develop a novel and rapid fluorescence/colorimetric dual-mode sensor for the visual and quantitative detection of NO2- by utilizing a specific reaction of nitrite with p-aminobenzoic acid (PABA) and N-phenyl-1-naphthylamine (NPN) under acidic condition. Specifically, nitrite could react with PABA/NPN/HCl probe solution via diazotization and azo coupling reaction to generate azo dye, therefore leading to an obvious colorimetric variation from colorless transparent to purple under white light with increasing the NO2- concentration. While the blue fluorescence of NPN at 452 nm could be quenched gradually after introducing NO2- (from 0 to 150 μM) into PABA/NPN/HCl probe solution, accompanied by the fluorescence color change from strong blue to light blue under 365 nm UV light. By the fluorescence and colorimetric signal variations, the proposed method enables the quantitative detection of nitrite within a linear range of 0.1 to 120 μM, with the limit of detection (LOD) down to 32 nM in fluorescent mode and 53 nM in colorimetric mode. Meanwhile, determination of nitrate can be achieved by reducing nitrate to nitrite using zinc powder/CdCl2 L-(+)-tartaric acid (L-TA) as reductants, and then reacting with PABA/NPN/HCl based sensor in the same way. Furthermore, integrated with the test paper that was previously impregnated in the probe solution and dried, the portable smartphone platform was successfully used for nitrite and nitrate detection in real samples with good anti-interference ability and high reliability, demonstrating the great application potential for food safety monitoring and soil nutrient determination.

Epigallocatechin (EGCG) is the predominant polyphenol compound of green tea. It is also reactive during processing and can form new catechin derivatives by reacting with other metabolites. In this study, two novel EGCG derivatives (EGCG-CAs) formed by conjugating caffeic acid (CA) were identified in green tea. Through the stimulated reaction, the formation of EGCG-CAs was systematically studied. The highest yield of EGCG-CAs was achieved when the initial mass ratio of EGCG to caffeic acid was 1:1 at 120 °C for 90 min. Quantitative analysis on tea samples undergoing processing revealed that EGCG-CAs were mainly formed at the fixation stage. Their contents were increased significantly after final drying. Based on sensory evaluation, it was indicated that S-configuration of 2‴ showed a higher threshold than that of R-configuration, suggesting that the methylene configuration of the caffeic acid moiety in EGCG-CA may be associated with the bitter taste threshold.

Birth control and sexually transmitted infections are global concerns. Nonoxynol-9 is the most commonly used component in spermicides, with controversial safety and efficacy. LL-37 has been considered the most promising antimicrobial peptide for developing spermicides. Thus, we aimed to refine the regime of N-9 through the adjunction of LL-37 with higher spermicidal efficacy, safety, and antimicrobial activity. Processed sperm from density gradient centrifugation were treated with nonoxynol-9, LL-37, or the combination for the spermicidal activity. Acrosome reaction, DNA fragmentation, and hemizona binding were evaluated. Minimal inhibitory concentrations were measured using E.coli. Mouse experiments were conducted to investigate the skin and vagina irritations. The spermicidal activities of nonoxynol-9 and LL-37 were dose-dependent. Premature acrosome reactions were shown in both two groups by increasing acrosome-reacted sperm at around 9% and 21% significantly, and interestingly, the combined group showed a synergistic effect by raising over 60%. In the DNA fragmentation, although there were no significant changes in the nonoxynol-9 or LL-37 groups, the combined group showed a 3% increase at a significant level. Both nonoxynol-9 and LL-37 showed reduced binding capacity with the hemizona binding indexes at 43.2 and 8.0, and the combined group showed the lowest capacity at 5.6. In animal experiments, the addition of LL-37 to the nonoxynol-9 could alleviate the disruptions caused by nonoxynol-9 in reducing skin epidermal hyperplasia and vaginal irritation. However, the presence of nonoxynol-9 would reduce the antibacterial activity of LL-37. This refined regime showed enhanced spermicidal effects, and reduced irritations, but only limited antimicrobial activity. Birth control and sexually transmitted infections are global concerns. One of the most common components used in spermicide to kill sperm is Nonoxynol-9, but there have been questions about safety and efficacy. LL-37 has been considered a promising component, together with its function in killing microbes. We aimed to design a spermicide using N-9 and LL-37 together, with potentially higher efficacy and safety. This refined regime showed improvements in killing sperm and improved effects on sperm functions. It also reduced the irritation to the skin and vagina, but only showed limited activity in killing the microbes.

Metallaphosphinidenes, [M-P], contain open-shell single-atomic phosphorus but typically display uncontrollable reactivity, preventing their utilization to selectively construct elusive functional groups. Here, we report an iridium phosphaethynolate complex, [(PCP)Ir(PCO)] (2), in a halide metathesis with Na(OCP). Photolysis of 2 leads to a bimetallic, side-on bound {P2} motif, [{(PCP)(OC)Ir}2(η2,η2;μ2-P2)] (3), via the intermediacy of a putative, triplet iridium phosphinidene, [(PCP)Ir(P)(CO)] (A), probed computationally. When 2 is instead photolyzed in the presence of a phosphorus ylide, PhMe2PCH2, the photointermediate is intercepted, leading to a unique phosphavinyl complex, [(PCP)Ir(P═CH2)] (4), in 60% spectroscopic yield. Complex 2 also reacts thermally with PhMe2PCH2 to form 4. Tracking of the extruded CO fragment uncovers a divergent reactivity landscape; in the photolytic pathway, a carbonyl complex, [(PCP)Ir(CO)](PCO), forms, whereas in the thermal pathway, one CO and two CH2 groups couple to a [C3] fragment in a new ylide, PhMe2PCHCOCH3. Structural characterization, isotopic labeling, and IR and NMR spectroscopic studies, along with quantum simulations, unveil a rigid, π-bonded [P═CH2]- moiety in 4, having magnetically inequivalent hydrogens at room temperature. Complex 4 comprises a deprotonated ligand form of the elusive phosphaethylene molecule (HP═CH2) but possesses a much lower isomerization barrier (15.9(5) kcal mol-1) than classical phosphaalkenes (>40 kcal mol-1), owing to an interplay between the [(PCP)Ir]+ and [P═CH2]- fragments, leading to a linear {Ir═P═CH2} transition geometry for this molecular switch. Lastly, we utilize the phosphavinyl ligand to form other rare π-constructs with an organic azide.

Here, we advance electrode-omics to identify evolutionary bursts by which ethereal locally superconcentrated electrolytes (LSCEs) mitigate silicon anode degradation through its epochs of electrochemical and chemical reactions. Anode composites form initially at high potential from ethereal solvent and anion [bis(fluorosulfonyl)imide (FSI-)] redox. A first evolutionary burst at lower potential enriches composites with lithium alkoxides (LiO-R) and lithium oxide (Li2O) and depletes sulfur oxides (SOx) species. As the cells are cycled, a second evolutionary burst takes place, where previously extinct SOx species reemerge concurrently with a loss of LiO-R and Li2O. This identifies reactions rooted in "SuFEx" chemistry, where oxoanionic LiO-R and Li2O species, electrochemically generated in the solid-electrolyte interphase, chemically react with FSI- in the electrolyte to form emergent species. This sequence of evolutionary bursts produces a mechanically resilient composite that reduces silicon anode cracking over hundreds of cycles, leading to overpotential increase of only ~0.01 volts after 200 cycles.

The interest in therapeutic applications of tetrahydrocannabivarin (THCV) recently increased. For this reason, we validated an online extraction liquid chromatography- tandem mass spectrometry (LC-MS/MS) method to investigate the formation of urinary metabolites and understand potential cross-reactivity of THCV metabolites in cannabinoid immunoassays. Urine samples were obtained after oral administration of Δ8-THCV to healthy participants. The protocol was approved by the Advarra Institutional Review Board (Pro00059879; approved December 20, 2021) and the trial was registered on clinicaltrials.gov (NCT05210634). Urine samples were collected pre-dose and pooled 0-8 hours post-dose. Urine samples were extracted using a simple one-step protein precipitation procedure and the extracts analyzed using online trapping LC-MS/MS in positive multiple reaction monitoring mode. All compounds passed validation criteria in urine. In the clinical samples, 11-nor-9-carboxy-Δ8-THCV (Δ8-THCV-COOH) was the main metabolite detected before and after incubation with glucuronidases. Of the urine pooled 0-8 hours post-dose, 70 out of 80 were reported positive by a cannabinoid immunoassay targeting Δ9-THC-COOH, despite being negative for Δ9-THC-COOH and positive mainly for Δ8-THCV-COOH in the LC-MS/MS analysis. The major metabolites of Δ8-THCV in urine were Δ8-THCV-COOH, 11-hydroxy-Δ8-THCV and Δ9-THCV-COOH that were extensively glucuronidated and cross-react with immunoassay routinely used for toxicology testing resulting in false positive results for Δ9-THC exposure.

Rechargeable sodium batteries (RSBs) have emerged as promising candidates in the post-lithium electrification era. However, their applications are often complicated by their inherent reactivity with flammable liquid electrolytes, which leads to dendrite growth, parasitic side reactions, and rapid performance degradation. In particular, conventional dual-ion electrolytes can exacerbate uncontrolled mossy and dendritic sodium metal growth, severely compromising their performance. In this work, we propose a tetraphenylborate-supported anionic metal-organic framework (MOF) as a promising single-ion conductive electrolyte to address the limitations of liquid dual-ion electrolytes. The anionic MOF is synthesized by reacting the sodium tetraphenylborate [Na+B(PhCOOH)4 -] building block with a Zr6-oxo cluster. Na+ counterions are directly encapsulated and serve as the free mobile charge carrier, achieving an ionic conductivity of 0.407 mS cm-1, an activation energy of 0.19 eV, and a Na+ transference number of 0.90. The developed anionic MOF-based solid-state electrolyte exhibits good interfacial compatibility with sodium metal and excellent rate performance. A combination of these properties enables the assembled solid-state RSB to deliver a remarkable capacity of 529 mA h g-1 at 0.1 A g-1 under ambient conditions and retain 424 mA h g-1 at 2 A g-1, with a capacity retention of 93.8% after 2500 charge-discharge cycles. Moreover, the fabricated solid-state RSB can operate stably within a temperature range of -40 to 70 °C and at current densities from 0.1 to 10 A g-1. Furthermore, Na+ ions in the anionic MOF can be exchanged with K+ and Zn2+, establishing this anionic MOF as a versatile single-ion solid electrolyte for solid-state potassium and zinc batteries, which deliver the capacities of 437 and 554 mA h g-1, respectively. This work not only establishes anionic MOFs as versatile and promising solid-state electrolytes for various types of solid-state batteries but also outlines a design blueprint for other anionic porous materials in energy storage.

The efficacy of photodynamic therapy (PDT) is often hindered by factors such as the poor bioavailability of photosensitizers, insufficient oxygen levels, and the elevated presence of glutathione (GSH) and hypoxia-inducible factor 1-alpha (HIF-1α) in tumor cells. To address these challenges, a controlled supramolecular assembly approach was explored to construct uniform cerium oxide nanoparticles, denoted Ala-Ce@Ce6. Specifically, water-soluble alanine-cerium clusters were constructed using natural l-alanine as the ligand. Subsequently, these clusters are subjected to self-assembly using the photosensitizer Chlorin e6 under ice-bath and ultrasonication conditions, yielding uniform nanoparticles with favorable water solubility. This nanostructure not only enhances the delivery efficiency of Ce6 but also confers dual functionalities, namely reacting with hydrogen peroxide (H2O2) to simultaneously generate oxygen and deplete GSH. In vivo, the reaction with endogenous H2O2 produces O2, thereby alleviating hypoxia and lowering HIF-1α expression. Additionally, Ala-Ce@Ce6 reduces the levels of GSH, downregulates Glutathione Peroxidase 4 to induce ferroptosis, and releases Ce6 upon laser irradiation to boost reactive oxygen species generation and suppress tumor growth, demonstrating strong clinical potential for use in PDT.