This cross-sectional study used functional near-infrared spectroscopy (fNIRS) to explore cerebral cortical activation and functional connectivity in children with Unilateral Cerebral Palsy (UCP) at resting state, during traditional non-virtual reality (non-VR) and single-session VR throwing motor tasks, aiming to clarify the differences in neural responses between VR and non-VR tasks, and provide preliminary neuroimaging evidence for VR application in pediatric cerebral palsy rehabilitation. A total of 35 children with UCP (18 males, 17 females, mean age 9.67 ± 2.4 years; 16 with left hemiplegia, 19 with right hemiplegia; 3 graded MACS Level Ⅰ, 13 Level Ⅱ, 19 Level Ⅲ) were enrolled, with the affected hemisphere standardized to the left. All participants completed fNIRS data acquisition in a randomized order under three conditions: 6-minute resting state (seated quietly with eyes closed), a single-session semi-immersive VR throwing task (8 s per movement cycle, with real-time audio-visual reward feedback for successful hits on horizontally moving virtual targets via ToF 3D motion capture), and a traditional non-VR throwing task with matched movement rhythm but no targets or feedback. fNIRS was used to monitor oxygenated hemoglobin (HbO₂) concentration in 6 regions of interest (ROIs): bilateral prefrontal (LPFC/RPFC), premotor (LPMC/RPMC) and sensorimotor cortices (LSMC/RSMC). One-way repeated measures ANOVA with FDR correction was applied for statistical analysis, which was verified by a professional biostatistician. Cerebral functional connectivity strength analysis showed that after FDR correction, there were significant main effects of task condition on the FCS of LSMC-LPMC [F(2,68) = 16.956, p < 0.001, ηₚ2 = 0.333], LPMC-RPFC [F(2,68) = 16.256, p < 0.001, ηₚ2 = 0.323], and LPMC-LPFC [F(2,68) = 22.725, p < 0.001, ηₚ2 = 0.401], all with large effect sizes (ηₚ2 ≥ 0.14). The FCS of these ROI pairs showed a consistent trend: resting state > single-session VR throwing motor task > non-VR throwing motor task, with significant differences between any two conditions (PFDR < 0.05). No statistically significant differences were observed in FCS between other ROIs (PFDR > 0.05). Cerebral activation level analysis showed that after FDR correction, there were significant main effects of task condition on the activation levels of the affected-side LSMC [F(2,68) = 15.952, p < 0.001, ηₚ2 = 0.319] and affected-side LPFC [F(2,68) = 13.606, p < 0.001, ηₚ2 = 0.286], both with large effect sizes (ηₚ2 ≥ 0.14). Specifically, the activation level of LSMC followed the order: single-session VR throwing motor task > non-VR throwing motor task > resting state; the activation level of LPFC followed the order: single-session VR throwing motor task > resting state > non-VR throwing motor task, with significant differences between any two conditions (PFDR < 0.05). No statistically significant differences were detected in activation levels of other brain regions (PFDR > 0.05). Based on functional near-infrared spectroscopy (fNIRS) technology, this cross-sectional study confirmed that children with unilateral cerebral palsy (UCP) exhibit distinct cerebral cortical neural activity patterns during a single-session VR throwing motor task, compared with the resting state and traditional non-VR throwing motor task. Specifically, the single-session VR motor task was associated with significantly higher activation levels in the left sensorimotor cortex (LSMC) and left lateral prefrontal cortex (LPFC) - the two regions in the affected hemisphere uniformly standardized to the left for all subjects - and modulated the functional connectivity between the premotor cortex and its functionally related brain regions. Compared with the traditional non-VR throwing motor task, the single-session VR throwing motor task elicited greater activation in the above-mentioned motor-related and higher-order cognitive brain regions, and induced a significantly different neural response pattern of the motor-cognitive network. The findings of this study reveal the cortical neural response characteristics of children with UCP during a single-session VR motor task, and provide preliminary neuroimaging evidence for subsequent studies exploring the neural mechanisms of VR-based rehabilitation in children with cerebral palsy.
Intramolecular OH···O hydrogen bonds remain difficult to describe at spectroscopic accuracy. Electronic correlation, vibrational averaging, and conformational flexibility all influence the same rotational constants and the corresponding structural parameters, often on a comparable scale. This is especially critical for oxygen-rich molecules of astrochemical and biochemical interest, where OH···O(R), OH···O═C, and OH···OH contacts coexist and can approach quasi-symmetric proton sharing. Here we benchmark a hierarchy of quantum chemical methods against rotational spectroscopy for hydroxyaldehydes, hydroxyethers, hydroxyacids, polyols, and the limiting case of malonaldehyde. The analysis is organized according to the actual computational layers of the protocol: equilibrium geometries, empirical geometrical corrections, local-correlation approximations, vibrational corrections, and final comparison with experimental ground-state rotational constants. Direct comparison with parent and deuterated rotational constants is combined with semiexperimental equilibrium structures whenever isotopic information is sufficient, thereby separating equilibrium-geometry errors from vibrational contributions. The resulting picture is clear. Double-hybrid and bond-corrected models remain useful low-cost approximations, but their accuracy deteriorates as covalent bond-based transferability breaks down in hydrogen-bonded systems. By contrast, inclusion of local-correlation in the explicitly correlated coupled-cluster ansatz emerges as the most robust reduced-cost approximations in the present set and, especially at the equilibrium-geometry layer, often approaches the quality of the reference conventional model (PCS2). The comparison between these two variants therefore primarily tests the error introduced by the local-correlation approximation, whereas the comparison between bare DFT and its bond-corrected variant addresses the transferability of empirical structural corrections. The structural analysis shows that the dominant residual error is concentrated in the O···H contact, whose variation is typically 1 order of magnitude larger than that of individual covalent parameters. This shift is redistributed over the full hydrogen-bonded pseudocycle, explaining why direct spectroscopic benchmarks are more discriminating than inspection of isolated local coordinates. Because PCS2 already reproduces the rotational constants accurately, it can serve as an internal structural reference within the present accuracy target, and the semiexperimental analysis then identifies the OH···O contact as the natural target for extending local-regression ideas from covalent bonds to hydrogen-bond interactions. At the same time, the present OH···O-specific mapping is intentionally preliminary and should be regarded as a proof of concept based on a limited set of localized systems, not yet as a generally validated correction framework. Malonaldehyde is treated separately in this respect, because its experimental rotational constants are tunneling-averaged dynamical observables rather than direct observables of a single localized equilibrium structure. These results define a practical hierarchy for extending spectroscopic-accuracy structural predictions to larger carbohydrates and related hydrogen-bonded systems.
A diagnostic simulation code for charge exchange recombination spectroscopy has been developed, aiming at performing a Bayesian inference of the velocity distribution function from the measured charge exchange emission spectrum. A code has been written to reproduce the emission spectrum based on the input velocity distribution function and other experimental information, such as magnetic equilibrium, neutral beam density distribution, line of sight geometry, and others. A set of demonstrations of Bayesian inference has been accomplished for the setting of a simple problem: the parametric inference of an ion temperature profile. An uncertainty estimation based on a Bayesian model evidence is presented by finding the optimum hyperparameter.
The photodetachment of ThF- has been investigated by combining photoelectron spectroscopy with relativistic quantum chemistry calculations. The electron affinity (EA) of ThF is experimentally determined to be 0.680 ± 0.007 eV. We also calculated the adiabatic detachment energy (ADE) and first vertical detachment energy (VDE1) of the anion to be 0.558 and 0.592 eV at the CCSD(T) level, respectively. The experimentally observed spectroscopic bands were accurately assigned to the relativistic electronic states of ThF with the aid of SO-CASPT2 calculations, and the calculated values are in good agreement with the experimental measurements, with discrepancies within 0.08 eV.
The reaction of [LaI3(THF)4] or [Ce(NO3)3(THF)4] with 4 equiv of in situ generated LiFmes (FmesH = 1,3,5-(CF3)3C6H3) resulted in the formation of the novel homoleptic lanthanide-aryl complexes [Li(THF)2(Et2O)2][La(Fmes)4] ([Li][1]) and [Li(THF)3.5(Et2O)0.5][Ce(Fmes)4] ([Li][2]), respectively. Likewise, the reaction of [Lu(NO3)3(THF)3] with 4 equiv of in situ generated LiFmes resulted in the formation of [Li(THF)3][LuF(Fmes)3] ([Li][3]). Complexes [Li][2] and [Li][3] were obtained as mixtures with unreacted LiFmes. Additionally, the reaction of [Lu(NO3)3(THF)3] with 4 equiv of in situ generated LiC6Cl5 and 3 equiv of DME resulted in the formation of the homoleptic lutetium-aryl complex, [Li(DME)3][Lu(C6Cl5)4] ([Li][4]). All four complexes were characterized by X-ray crystallography and multinuclear NMR spectroscopy. In the solid state, all four complexes exhibit weak F/Cl→Ln dative interactions; however, these interactions do not apparently offer much stability, since all four complexes are thermally sensitive. DFT calculations reveal that the Ln-Cipso and Lu-F bonds are modestly covalent, although the Lu-F bond exhibits less covalency than the Ln-Cipso bonds. The calculations also indicate that the La-Cipso bonds exhibit a small amount of 4f orbital participation, whereas the Lu-Cipso bonds have (as expected) no 4f character. Despite this difference, the spin-orbit deshielding effects on the Cipso 13C chemical shifts are comparable between complexes [1]- and [3]-.
The photoacid 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) is one of the most widely used fluorescent probes for studying proton transfer and local pH in systems from advanced materials to plants, environmental sensors to medicine. HPTS exists as two different species: the acid and its conjugate base, which lead to unique protonation-state-dependent translocation of the molecule when it is nanoconfined within anionic AOT reverse micelles. Using steady-state and time-resolved optical spectroscopy, molecular simulations, and IR solvation shell spectroscopy, we report that the protonated HPTS species associates strongly with the micelle interface via hydrogen bonding. In contrast, its deprotonated species resides in the micelle's aqueous interior. Our results show that photoexcitation of the acid species and its subsequent deprotonation leads the conjugate base to rapidly move away from the interface into the water pool. This light-induced translocation, an effect observed for a range of micelle sizes, challenges the prevailing view where molecular probes are assumed to be static reporters of their environments, remaining in a fixed location for the duration of an experiment. This is especially relevant for interpreting results in the numerous studies enlisting optical spectroscopy of HPTS to report on complex systems. Our findings reveal the potential for molecular probes as dynamic explorers capable of mapping environmental heterogeneity on the timescale of the very processes they are designed to measure.
Developing highly active and durable acidic oxygen evolution reaction (OER) electrocatalysts remains a central challenge for proton-exchange membrane water electrolysis (PEMWE). Here, we combine theory-guided design, atomic-layer engineering, and operando spectroscopy to create a structurally robust, mechanistically tuned Ru-based catalyst. Density functional theory reveals that depositing W1O3 onto RuO2 maximizes Ru and O vacancy formation energies, outperforming other tested transition metals. Guided by this, we employ atomic layer deposition to construct atomically coupled W-O-Ru interfacial units on RuO2 (W-O-RuO2), generating a tensile-stressed surface while preserving the rutile core. Comprehensive in situ spectroscopy and mass spectrometry demonstrate that this architecture effectively suppresses lattice-oxygen activation, shifting the reaction from a lattice-oxygen mechanism to a more reversible adsorbate evolution mechanism. Operando x-ray absorption spectroscopy confirms the dynamic stability of the W-O-Ru interface during OER, which evolves into a resilient, mildly compressive (1%) state without degrading. Consequently, W-O-RuO2 demands a mere 168 mV overpotential at 10 mA cm- 2 and sustains 1 A cm- 2 in a PEMWE device for 1000 h with an ultra-low degradation rate of 63.3 µV/h. This work establishes interfacial unit engineering as a generalizable blueprint for designing exceptionally stable acidic OER catalysts.
Efforts to create rapid, non-invasive, and reliable cancer diagnostics have increasingly focused on extracellular vesicles (EVs), nanoscale carriers of proteins, lipids, and nucleic acids that mirror the molecular state of their parent cells and mediate communication within the tumor microenvironment. Their complex composition and heterogeneity present however, significant challenges for analytical characterization. Raman spectroscopy, with its ability to probe molecular vibrations, has emerged as a possible technique for EV analysis. In this review, we highlight recent advances in Raman-based techniques, including conventional Raman, surface-enhanced Raman spectroscopy (SERS), tip-enhanced Raman spectroscopy (TERS), and emerging hybrid modalities where nanomaterials serve as critical platforms to amplify signals and resolve EV heterogeneity. We discuss how engineered nanostructures enable sensitive detection, molecular fingerprinting, and spatially resolved characterization of EVs. Integration with machine learning data analytics approaches further enhances classification accuracy across healthy, benign, and malignant samples, improving the accuracy and reliability of the spectroscopic investigation. Finally, we discuss translational prospects, including AFM-IR technologies that appear particularly well suited to the analysis of single EVs, enabling interrogation of both surface chemistry and internal cargo owing to the greater penetration depth of infrared radiation. In parallel, microfluidic platforms offer powerful solutions for the controlled delivery, sorting, and trapping of EVs within optical microscopy configurations. Collectively, the continued development and integration of these non-invasive analytical tools hold substantial promise for EV-based cancer diagnostics and open new avenues for biomarker discovery.
In modern nanotechnology, laser interference, electrons, and ion beams are commonly used to fabricate advanced nanostructured systems for Surface-Enhanced Raman Spectroscopy (SERS) sensing applications. In recent years, Depth-Sensing Nano Indentation (DSNI), a cost-effective nanolithography technique, has been explored as an attractive "clean" methodology for direct-writing and chemical-free fabrication of SERS-active nanostructured surfaces. In this work, we report, for the first time, an exhaustive research that validates the use of an Express Property Mapping (XPM) ultrafast DSNI module for fabricating functional SERS-active surfaces based on nanopatterned Ag photonic crystals, providing valuable insights into the impact of fabrication parameters on SERS performance and large-scale manufacturing projections. A Berkovich diamond nanoindenter was used to fabricate DSNI-nanopatterned surfaces on 100 nm-thick Ag thin films, which consisted of 25 × 25 nanoindentation arrays with submicron periods and plastic strain depths fabricated in a few minutes. Periods varying from 0.4 to 1 μm, comparable to the Raman excitation wavelength, were considered. The SERS performance was assessed by Confocal Raman Spectroscopy using Methylene Blue (MB) as Raman tracer. Nanopatterned Ag photonic crystals presented considerably higher SERS enhancement than simple Ag thin film surfaces, revealing a critical impact of periodicity and indentation depth on the SERS performance. A maximum SERS enhancement factor of ∼105 for a MB surface mass density of 3.6 ng/cm2 was achieved for the most efficient photonic crystal. Our results provide a novel and interesting paradigm for the application of ultrafast nanoindentation modules for cost-effective SERS-active systems, as well as meaningful physical insights into instrumental and fabrication issues, representing a substantial advance toward the implementation of clean nanolithography approaches for SERS applications.
Zinc plays an essential role in glucose metabolism, insulin storage, and antioxidant defense, and its deficiency has been linked to impaired pancreatic β-cell function and increased oxidative stress. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized through a green, plant-mediated approach using aqueous extracts of three commonly consumed millets (Eleusine coracana (finger millet), Pennisetum glaucum (pearl millet), and Panicum sumatrense (little millet)). The millet extracts acted as natural reducing agents during nanoparticle formation, leading to the production of crystalline ZnO nanoparticles under alkaline conditions.The synthesized ZnO NPs were characterized using UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM), dynamic light scattering (DLS), and zeta potential analysis to confirm their phase purity, morphology, crystallinity, and colloidal stability. The nanoparticles exhibited a hexagonal wurtzite ZnO structure with crystallite sizes in the nanometer range, while the hydrodynamic sizes were larger due to surface hydration and aggregation effects.In vitro biological evaluation showed that millet-derived ZnO NPs exhibited dose-dependent inhibition of carbohydrate-digesting enzymes (α-amylase and α-glucosidase) along with moderate inhibition of dipeptidyl peptidase-IV (DPP-IV). Cellular studies using INS-1 pancreatic β-cells and 3T3-L1 adipocytes demonstrated enhanced glucose-stimulated insulin secretion and increased glucose uptake at non-cytotoxic concentrations. In addition, the nanoparticles showed antioxidant activity, as indicated by reduced intracellular reactive oxygen species (ROS) levels and increased activities of endogenous antioxidant enzymes.Overall, this study demonstrates that millet extracts can be effectively used for the green synthesis of ZnO nanoparticles, producing nanomaterials with promising in vitro antidiabetic and antioxidant properties. The comparative evaluation across different millets also provides useful insight into how phytochemical composition influences nanoparticle characteristics and biological performance.
Monovalent gallium halides are intrinsically unstable compounds at room temperature and can only be generated in the gas phase at temperatures of about 1000 °C. Although they are isoelectronic to carbon monoxide, dinitrogen, and the cyanide ion, which are pivotal ligands in coordination chemistry, monovalent gallium halides are largely unexplored as ligands with transition metals. Herein, we report the isolation of a dicationic nickel complex bearing a gallium monofluoride ligand. The +I oxidation state of the gallium centre is supported by NMR-spectroscopic methods, X-ray photoelectron spectroscopy, as well as density functional theory calculations. Analysis of the bonding situation between the GaF ligand and the central nickel atom suggests strong σ-donating, but negligible π-accepting properties for the supported GaF fragment. The GaF moiety forms as a product of C(sp3)-F bond activation of the weakly coordinating BArF24 (tetrakis[(bis-3,5-trifluoromethyl)phenyl]borate) anion and serves as a fluorine source for silicon and carbon electrophiles. This leads to facile defluorination, forming the fluoride-free complex and fluorinated products such as fluorotrimethylsilane or benzoyl fluoride.
Excited-state intramolecular proton transfer (ESIPT) has emerged as a pivotal mechanism in the realm of molecular photoswitches and the design of novel photoelectronic materials. In aromatic proton-donor-π-acceptor (D-π-A) ESIPT systems, the enol tautomer typically dominates in the ground-state, rendering the stabilization of the keto tautomer a challenging task. Herein, we indicate that single N-methylation of 2-(2'-hydroxyphenyl)-benzimidazole (HBI) facilitates the co-existence of enol and keto tautomers in the ground electronic state, thereby enabling precise modulations of emission through adjusting the excitation energy. In protic solvents, solvation inhibits ESIPT, significantly enhancing enol fluorescence while quenching keto emission. In addition, the formation of an anion introduces a third, blue-emitting species, enabling a three-color fluorescence system. Femtosecond transient absorption (fs-TA) spectroscopy and time-dependent density functional theory (TDDFT) calculations were employed to elucidate the ESIPT mechanism, revealing the role of solvents, structural modifications and intramolecular proton transfer. This study establishes a general strategy for modulating the photochemical properties of materials by incorporating substituents into ESIPT systems, thus unlocking substantial potential for stimuli-responsive sensors and anti-counterfeiting materials.
To investigate the changes in cognition, anaerobic power, and corresponding cerebral cortex activation characteristics and functional connectivity (FC) following fatigue induced by an acute simulated tennis match. Eighteen healthy adult male tennis enthusiasts (tennis experience: 5 ± 1.4 years, age: 24.5 ± 2.4 years) participated in this study. The participants performed a 90-minute simulated tennis match to induce fatigue. Behavioral data from 2-back task and Wingate tests were collected at three time points: pre-fatigue, immediately post-fatigue, and 1-hour post-fatigue. Functional near-infrared spectroscopy (fNIRS) was simultaneously used to measure oxyhemoglobin (HbO) levels and 3-minute resting-state FC in the frontal and parietal lobes. At 1-hour post-fatigue, 2-back reaction times (RT) increased compared to pre-fatigue, with no significant change in accuracy. During the 2-back task, HbO levels decreased in the right dorsolateral prefrontal cortex (R-DLPFC) at both post-fatigue time points, whereas frontopolar area (FPA) reductions were more evident at 1-hour post-fatigue. The R-DLPFC was found to play a more critical role in cognitive tasks than the L-DLPFC, and an increase in RT was observed to be negatively correlated with HbO in the R-DLPFC. Peak power and average power output declined immediately and 1-hour post-fatigue compared to pre-fatigue. During the Wingate test, HbO reductions were observed in the R-DLPFC and R-PMSMC at both post-fatigue time points, and in the L-PMSMC at 1-hour post-fatigue. FC decreased more prominently 1-hour post-fatigue, marked by reduced connection strength in specific regions of interest and channels. The decline in cognitive and physical performance following tennis-induced fatigue is accompanied by decreased cerebral HbO and FC. This reduction in HbO may indicate a decreased supply of oxygen to the brain and lower levels of brain activation, which could be crucial factors influencing both central and peripheral fatigue during tennis fatigue.
A package of raw material, deliberately mislabelled as a muscle-building supplement, was obtained online to contain an unknown steroid. In order to accurately identify the composition of the substance, we used a combination of advanced techniques: liquid and gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS and LC-HRMS), alongside nuclear magnetic resonance (NMR) spectroscopy. By combining the strengths of these methods, we successfully identified the compound as 6-Bromo-androst-4-en-3,17-dione (6-BrAED). This substance is a designer steroid of testosterone that is not currently on the World Anti-Doping Agency (WADA) prohibited list. As it is unlisted, there is a serious hidden risk that athletes could take it by accident through contaminated supplements.
Maximizing the utilization efficiency of surface-active atoms is essential for improving carbon monoxide (CO) tolerance of hydrogen oxidation reaction (HOR) catalysts. However, conventional active-site regeneration strategies suffer from poor accessibility and low efficiency, hindering effective anion exchange membrane fuel cells (AEMFCs) operation under high-CO-concentration conditions. Here, we show a unique YbOx/Ni/C catalyst with Janus heterostructures that can significantly enhance the utilization efficiency of free active atoms by selectively adsorbing CO and promoting their directional elimination. Atomic resolution electron energy-loss spectroscopy (EELS) analysis reveals that the gradient electronic states in Janus heterostructures are generated between the interfaces of YbOx/Ni and Ni/C. Density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations further reveal that electron-rich Ni atoms near the Ni/YbOx interface serves as active sites for efficient removal of CO. In contrast, electron-deficient Ni atoms situated near the Ni/C interface facilitate the efficient HOR. The AEMFC with this anode catalyst achieves an impressive peak power density (PPD) of 702.0 mW cm-2 in H2-O2, maintains a PPD of 304.3 mW cm-2 even in 1000 ppm CO/H2-CO2-free air and continues to operate under harsh conditions with 10000 ppm CO, first showing the possibility to use crude hydrogen in AEMFCs.
Metal-oxide ceramics with perovskite-related structures offer tunable properties for sensing applications. The strontium iron vanadate ceramic system remains underexplored for humidity sensing despite theoretical interest in Sr2FeVO6-type compositions. This study presents sol-gel synthesis of a strontium iron vanadate ceramic at 900 °C and its characterization as an impedance-type humidity sensor. XRD revealed a multi-phase composition with a perovskite-related Ia3̄d superstructure (a = 10.040 Å, 20 superstructure reflections systematically absent in Pm3̄m) and Sr-vanadate phases. FTIR confirmed a hydrophilic metal-oxygen framework with BO6 octahedral vibrations characteristic of perovskite-related structures. SEM showed ∼1.6 µm grains with inter-particle porosity; DLS showed ∼460 nm agglomerates. The zeta potential was -15 mV, indicating surface hydroxylation. Impedance spectroscopy (50 Hz-5 MHz, 11-97% RH) demonstrated 621% per %RH sensitivity at 50 Hz with two clearly separated conduction regimes: localized hopping mechanisms dominating at low RH and long-range proton transport occurring through continuous water pathways at elevated RH. The dielectric permittivity increased to approximately 106-107 at low frequencies, accompanied by a more conduction-related loss behavior at higher humidity, while the AC conductivity rose by nearly four orders of magnitude. This work reports the humidity sensing properties of a sol-gel-derived strontium iron vanadate ceramic with perovskite-related contributions and provides mechanistic insight into two-stage conduction behavior.
The present work demonstrates that surfactant-free precipitation of Pd- and Pt-TCPP in MeOH/H2O yields well-defined supramolecular architectures (µm-long nanorods) whose photocatalytic function tracks their metal-dependent photophysics and stacking. Among all tested M-TCPPs (M = Pd, Pt, Zn, Au, and Co), only Pd-TCPP and Pt-TCPP assemble to nanorods that are intrinsically active for H2 evolution without any Pt cocatalyst, with Pd-TCPP outperforming Pt-TCPP robustly across the optimal aggregation window (pH ≈ 4-5). In fact, the cocatalyst-free Pd-TCPP nanorods surpass many other state-of-the-art porphyrin platforms, including Zn-TCPP assemblies operated with high-loaded Pt cocatalysts, as well as porphyrinic metal-organic frameworks (MOFs). The self-assemblies display J-type π-π stacking stabilized by carboxylate hydrogen bonding, producing broadened, red-shifted light absorption and efficient charge transport. Correlating XRD analysis, spectroscopy, and electrochemistry reveals that compared to Pt-TCPP, Pd-TCPP nanorods exhibit tighter π-π stacking, extended triplet-state lifetime, and lower charge-transfer resistance, consistent with more efficient charge separation and faster interfacial electron transfer. Importantly, the approach taken in this work allows for one-pot, surfactant-free, co-catalyst-free operation of Pd-TCPP nanorods that not only is of low synthetic complexity but also avoids surfactant residues while delivering a high and stable photocatalytic H2 production activity under visible illumination.
Considering the significant importance of the phosphonate-mediated Horner-Wadsworth-Emmons (HWE) olefination reaction in organic synthesis, phosphamides are explored here as a mediator to perform P-N bond scission and simultaneous C═N condensation with a variety of substituted benzaldehydes through a HWE-type pathway under mild reaction conditions (60 °C and 12 h). Reaction kinetics, D-labeling (KIE: 1.23), Hammett study and characterization of reaction intermediates through in situ spectroscopy highlight that the deprotonation of "P(O)-NH" unit occurs in the very first step, followed by the C═N bond formation, and is preferred by electron-deficient substituents. Computationally optimized geometry of the phosphamides (PN-1 to PN-5) and their deprotonated form showed that N-H deprotonation shortens the P-N bond and elongates the P-O bond, indicating charge delocalization with partial P═N and P-O- character. Electron-deficient substituents stabilizes the monoanionic species, and PN-4 (-NH-Ph-Cl) exhibits the highest HOMO energy, suggesting enhanced nucleophilicity and reactivity toward benzaldehyde. The P-N bond dissociation of phosphamides via HWE-type reactions further enables a clean and selective approach for upcycling polyphosphamides into valuable imines. Notably, this method has been depicted as a sustainable path in selectively recovering cotton fabric from polyphosphamides, commonly used as flame-retardant materials, demonstrating its feasible depolymerization applications.
Chlorine (Cl2) is a hazardous industrial gas and a choking agent, making highly sensitive ppb-level detection with tunable selectivity toward chemical warfare agent-related (CWA-related) analytes important. Here, we synthesized Ag-functionalized SnO2 and WO3 nanofibers by electrospinning and investigated how the host oxide governs Cl2 sensing and selectivity toward CWA-related analytes. The optimized Ag-functionalized SnO2 sensor (AgS5) showed a response of 6.89 to 500 ppb Cl2, an experimentally validated detection limit of 10 ppb, and a calculated lower limit of detection of 0.12 ppb. The host oxide also strongly altered selectivity: SnO2-based sensors showed higher responses to Cl2 and hydrogen cyanide, whereas WO3-based sensors were more sensitive to 2-chloroethyl ethyl sulfide and methyl salicylate. X-ray photoelectron spectroscopy revealed host-dependent Ag speciation, with Ag+ favored on SnO2 and Ag0 on WO3. Temperature-modulated measurements and density functional theory calculations further showed that this difference changes interfacial charge-transport barriers and adsorption energetics, thereby governing both sensitivity and selectivity. These results suggest a trace-level Cl2 sensor and demonstrate that the sensing characteristics of noble metal-decorated chemiresistors can be rationally tuned through host-oxide selection, providing a general design strategy for selective, ppb-level Cl2 detection.
Near infrared spectroscopy (NIRS) is emerging as a promising method of assessing individualised cerebral oxygenation responses to red blood cell (RBC) transfusion. However, the impact of liberal (high) versus restrictive (low) haemoglobin thresholds on transfusion-related changes in cerebral tissue oxygenation (crSO2) remains unclear. This meta-analysis compares cerebral oxygenation changes in preterm neonates following transfusion with liberal compared to restrictive haemoglobin thresholds. Data was extracted (PubMed/Medline, Embase, Web of Science, and Cochrane Database of Systematic Reviews) and risk of bias and certainty of evidence reviewed. Included studies reported changes in cerebral oxygenation in preterm infants receiving RBCs in response to reaching either a liberal or restrictive transfusion threshold. A random-effects model was used to determine effect size and 95% confidence for the primary outcome of change in crSO2. Forty-three full text articles were assessed for eligibility with seven studies included for meta-analysis (restrictive threshold: n=357, liberal threshold: n=220). crSO2 increased following transfusion in both the restrictive (6.40% 95% CI [3.85, 8.95], p<0.001) and liberal (2.75% 95% CI [0.35, 5.14], p=0.03) groups. However, the magnitude of change was greater for those transfused at a restrictive threshold (Q=4.19, df=1, p=0.04). The restrictive group also demonstrated a greater transfusion-related decrease in cerebral fractional oxygen extraction than the liberal group (Q=8.30, df=1, p<0.001). Greater improvements to cerebral oxygenation occurred in preterm neonates with a restrictive threshold, suggesting enhanced physiological benefit in response to transfusion. However, meaningful clinical conclusions are limited due to low certainty of evidence and considerable inconsistencies across reporting.