Browse Articles

Round robin test on polystyrene bead number concentration measurement using flow cytometry and commercial automated particle counters

Abstract Reliable particle counting is critical for applications such as clinical monitoring and cell therapy manufacturing. However, various particle counters using different measurement principles are employed, and the absence of reference materials makes standardization challenging. We conducted a round robin test to evaluate the accuracy and reproducibility of particle number concentration measurements using monodisperse polystyrene beads. The study material was prepared, characterized for homogeneity and stability, and assigned a reference value using the volumetric sample loop method. Internal comparisons showed that methods relying on counting beads and automated counters reported concentrations 9–10% higher than the reference value. The material was distributed to three instrument manufacturers, each employing automated counters. The reported results deviated from the reference value by approximately 10%. Feedback from participants highlighted calibration practices and flow cell artifacts as potential sources of bias. Expanded uncertainties, considering repeatability and method-specific factors, ranged from 8% to 11%, with all results falling within the expanded uncertainty of the reference value. This study demonstrates the importance of uncertainty estimation in interlaboratory studies and highlights the need for harmonized results in particle counting. The findings provide a basis for future standardization efforts in particle and cell counting methods.

Nitro Reduction‐Based RNA Control and Ultrafast Release

ABSTRACT RNA protection and controlled release are critical for both fundamental research and therapeutic applications, yet the development of simple, efficient, and reversible post‐synthetic RNA modification strategies remains a significant challenge. Here, we introduce a straightforward approach based on ribose 2′‐hydroxyl acylation with a nitro‐functionalized carbamate, which acts as a redox‐responsive center. This modification selectively inhibits native RNA function while remaining inert to endogenous biogenic reductants and common reducing agents used in biological assays. Upon treatment with low millimolar concentrations of the diboron‐bipyridine reducing pair, RNA function is rapidly restored on a minute timescale. This methodology is broadly applicable across diverse RNA classes and functional contexts, including synthetic RNA oligomers, fluorogenic RNA aptamers, single guide RNAs in CRISPR–Cas9 gene‐editing systems, and mRNAs in living cells for translation control and RNAi‐mediated gene silencing. These results demonstrate the general utility of this approach as a chemically controllable functional switch, providing a versatile toolkit for temporal regulation of RNA activity in both research and biotechnological applications.

Human-machine interaction during robotic-assisted sit-to-stand

Abstract Standing up from sitting is a common yet mechanically demanding activity of daily living. Those with motor impairments often have difficulties performing sit-to-stand transfers independently. Robotic devices can help them to perform and train this movement, providing mechanical assistance and high numbers of task-specific repetitions. Our limited understanding of human-machine interaction at the neural and muscular levels during robotic-assisted sit-to-stand transfers hinders the development of responsive sit-to-stand devices. Therefore, this study investigates independent and robotic-assisted sit-to-stand transitions, comparing synchronised kinematic, electromyography (EMG) and electroencephalography (EEG) data. Neuro-intact participants ( N  = 10, 3 males) performed sit-to-stand repetitions, firstly when performed independently and secondly with assistance from a robotic-assisted gait training device. Kinematic data were recorded using a three-dimensional motion capture camera system. EMG was recorded at the bilateral vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius muscles. Surface EEG activity was recorded using eight focused bipolar channels over the sensorimotor cortex. Kinematic data identified sit-to-stand with robotic assistance took significantly longer compared to the independent condition (median difference 4.5 s; p  = 0.038). The flexion phase was prolonged by 3 s, although variability was high ( p  = 0.064). EMG data suggested a general trend towards reduced lower limb muscle activity during robotic-assisted trials for most muscle groups and phases of sit-to-stand. The exception was the gastrocnemius muscle where peak activity was significantly increased compared to independent trials (Left: q = 0.032; Right: q = 0.040). EEG data highlighted differences in cortical activity between the sit-to-stand conditions, notably where the distinct ERSP patterns evident during independent sit-to-stand were absent or inconsistent in the robotic-assisted condition. The largest differences were observed in alpha and beta bands, at the central electrodes and during upright standing post-movement. This study identified longer times to complete the exoskeleton-assisted task, a trend towards reduced muscle activation, and altered cortical patterns of movement intent and execution. The findings indicate that robotic assistance may modulate neural and muscular processes associated with motor learning, underscoring the importance of developing devices that are more adaptive and responsive to individual user needs. The results inform future brain-computer interface rehabilitation system design, suggesting that a system may need to be trained with the person in the device to ensure accurate cortical pattern recognition.

Modifying Surfactants Within Divergent Pores of Cluster‐Based Metal‐Organic Frameworks for Syngas Electrosynthesis

ABSTRACT The electrochemical reduction of CO 2 to syngas (CO and H 2 ) provides a potential pathway for synthesizing fuels, but the ability to modulate the syngas composition across a wide range using a catalyst of invariant composition faces considerable difficulties. Herein, we report a new strategy to incorporate ammonium (R 4 N + ) surfactants into the divergent pores of cluster‐based metal‐organic frameworks (MOFs) to regulate the electrocatalytic CO 2 and H 2 O reduction for efficient syngas production. Two divergent clusters, including a symmetric Cu 6 S 6 cluster and an asymmetric Cu 8 S 6 cluster on MOFs, allow the formation of two types of well‐defined pores that selectively accommodate cationic quaternary ammonium surfactants and their anionic counterions, respectively, for modifying the interface of the cluster. The surfactants with longer alky chains sufficiently occupy the inner pore of MOFs, and suppress proton reduction and enhance CO 2 reduction, resulting in tunable syngas compositions, with CO/H 2 ratios ranging from 0.01 to 4.31. Through careful validation of host‐guest interactions between the surfactants and the pores of coordination polymer via co‐crystallization results, the structure‐activity relationship between the surfactants and the catalytic sites was elucidated in depth, providing new insights into the rational regulation of electro‐catalytic pathways via a supramolecular approach.

Effect of raised-bed planting on irrigation water use and water productivity in common bean (Phaseolus vulgaris L.)

Unlocking <i>n</i> ‐Propanol Electrosynthesis From CO ₂ via Constructing *CO─H ₂ O Reaction Microregion

ABSTRACT Selective electroreduction of CO 2 (CO 2 RR) to n ‐propanol represents a promising route for low‐carbon chemical synthesis. However, achieving high selectivity at industrially relevant current densities remains challenging due to inefficient *CO utilization and strong competition from C 2 products. Herein, we demonstrate that a Cu 2 O/CeO 2 interfacial catalyst overcomes these limitations by constructing a *CO─H 2 O reaction microregion that facilitates selective C 1 ─C 2 coupling. Isotope‐competitive in situ differential electrochemical mass spectrometry (DEMS) reveals that the CeO 2 ‐induced interfacial structure shifts protonation pathway of activated CO 2 from adsorbed hydrogen to solvent hydrogen, thereby generating high local *CO flux. Under CO 2 RR conditions, the *CO─H 2 O reaction microregion arises from non−covalent interaction between high‐density *CO and loosely H‐bonded water molecules. Time‐resolved pulsed spectroscopy and theoretical calculations confirmed that this microregion dynamically confines *CO and reduces their molecular orbital degeneracy, enhancing *CO availability for C─C coupling reaction. Site‐specific kinetics isotope effect experiments further indicate the reaction microenvironment promotes *CO attack on the α carbon of *C 2 intermediates, effectively steering reaction pathway toward n ‐propanol. As a result, the catalyst achieves n ‐propanol Faradaic efficiency (FE) of 26.1%. These findings underscore the significance of non‐covalent interactions between intermediates and electrolyte in controlling proton‐related surface reaction, offering opportunities for steering electrocatalytic pathways toward valuable products.

Historical climatic and human settlement patterns leading up to the extinction of the Arabian leopard in the Sinai Peninsula

Rigidochromic Fluorophores Identify Single Monomer Mutation on Synthetic Macromolecular Chain

ABSTRACT Efficient detection of monomer mutations along polymer chains is critically important for functional materials, particularly for biomacromolecules, yet remains highly challenging. Here, we present an optical strategy capable of recognizing a single monomer mutation within a polymer chain or cluster containing up to 1000 repeating units. This approach relies on a rigidochromic fluorophore that interacts with polymer chains through polar–π interactions to form a charge‐transfer complex (CTC), resulting in red‐shifted emission relative to the intrinsic fluorescence of the fluorophore. Monomer mutations alter intra‐ and interchain interactions, modulate through‐space conjugation (TSC) along the polymer backbone, and consequently change the molecular orbital energy bandgap, leading to distinct emission variations of the CTC. Leveraging this mechanism, we achieve visual discrimination among random copolymers (poly(A‐r‐B)), block copolymers (poly(A‐b‐B)) with identical A/B ratios and molecular weights, and corresponding blends of homopolymers (poly A + poly B)—a task that is inaccessible to conventional characterization methods. This strategy provides a powerful platform for high‐throughput polymer screening during synthesis and modification, as well as for real‐time monitoring of polymer structural evolution.

KK12, a novel anticancer peptide, induces apoptosis in human lung cancer A549 cells

Ferromagnetic Coupling in Dual‐Atom Nanozymes Enables Spin‐Favorable Catalase‐Like Catalysis for Rheumatoid Arthritis Therapy

ABSTRACT Iron dual‐atom (Fe DA) nanozymes, structurally analogous to natural catalase, exhibit promising catalase‐like (CAT‐like) activity, yet further improving their catalytic performance and elucidating the underlying mechanism remain major challenges. Herein, we developed a cascade strategy integrating vacancy induction and electrostatic adsorption to construct two representative Fe DA nanozymes, pr‐Fe‐DA and py‐Fe‐DA, with coordination environments dominated by pyrrolic‐N and pyridinic‐N, respectively. The resulting py‐Fe‐DA exhibits an exceptionally high CAT‐like activity of 100 U mg −1 , which is 2.4 times that of pr‐Fe‐DA (42 U mg −1 ), representing the highest value reported to date. Mechanistic studies and density functional theory calculations reveal that modulating the nitrogen coordination environment from pyrrolic‐N to pyridinic‐N promotes an antiferromagnetic‐to‐ferromagnetic transition in the magnetic coupling between Fe sites. This transition enables spin‐favorable H 2 O 2 activation through parallel spin alignment of the oxygen atoms in adsorbed H 2 O 2 , thereby accelerating O─H bond cleavage and O 2 generation while decreasing the Gibbs free energy change of the rate‐determining step from 0.84 to 0.08 eV. Moreover, py‐Fe‐DA effectively alleviates oxidative stress and inflammation in rheumatoid arthritis models. These findings identify magnetic coupling as a key descriptor of CAT‐like activity and establish magnetic‐coupling engineering as a powerful strategy for designing high‐performance nanozymes.

A training data reduction scheme for electromyography, force myography, and their combination under varying limb positions and loading conditions

Abstract Devices that rely on hand gesture recognition as a form of control require accurate and reliable classification performance to ensure effective use. Two techniques used for this purpose include electromyography and force myography, which rely on consistent muscle activity for accurate hand gesture classification. However, their effectiveness is reduced by changes in limb position and loading during object interaction, which introduce variations in the recorded signal, thereby increasing the rate of gesture misclassifications. Since limb movement and object interactions are crucial aspects of how we use our hands in daily life, our previous work investigated how the changes in limb position and loading affected three sensing modalities: electromyography, force myography, and their combination. Here, we build upon our previous work and develop a strategic training strategy to reduce the requisite training data, and correspondingly, required time, while preserving gesture classification accuracy for these three muscle measurement modalities. We used a forward wrapper method to quantify the impact of reducing training data, while also identifying a threshold where additional training data no longer benefits classification accuracy. These results can be used to strategically select training conditions for hand gesture classification systems to reduce training time and ensure reliable classification.

A Light‐Switchable Polyoxometalate “Electron Pump” in a One‐Dimensional Copper Coordination Polymer: Near‐Unity Selective CO ₂ Photoreduction to Methane

ABSTRACT Photocatalytic CO 2 reduction to methane (CH 4 ) is highly desirable but severely hindered by sluggish multiple proton‐coupled electron transfer (MPCET) kinetics and poor product selectivity. In this study, we report a novel one‐dimensional (1D) copper coordination polymer, termed Cu‐PMo 12 , featuring single‐site Cu centers periodically bridged by Keggin‐type {PMo 12 } clusters. Comprehensive experimental and theoretical studies reveal a synergistic mechanism governed by static electronic modulation and dynamic photoactivation. In the ground state, {PMo 12 } acts as an electron acceptor, withdrawing electrons from Cu sites to upshift the Cu d ‐band center, thereby strengthening the binding affinity toward intermediates. Under visible‐light irradiation, {PMo 12 } functions as a photosensitizer and a light‐switchable “electron pump”, directionally injecting photogenerated electrons to Cu sites to dynamically maintain highly active Cu(I) species for the subsequent MPCET process. Consequently, Cu‐PMo 12 achieves an exceptional CH 4 evolution rate of 70.5 µmol g Cu − 1 h − 1 with near‐unity selectivity (∼100%) and excellent durability. This work highlights precise microenvironment engineering via polyoxometalate‐metal integration and provides a paradigm for designing light‐driven “electron pump” systems for challenging multi‐electron catalytic transformations.

Psychological factors associated with readiness for parenthood among Indonesian and Japanese university students

Abstract Readiness for parenthood is an important psychological resource that helps young adults anticipate future family roles and may reflect perceived preparedness for future parenting responsibilities during emerging adulthood. This study examined cross-national differences and psychological predictors of readiness for parenthood among emerging adults in Indonesia and Japan. Participants were 535 university students (68.2% women) aged 17–26 years (Mage = 19.3, SD = 1.39) who completed measures of parenthood readiness, self-esteem, positive relationship-building ability, and problem-solving ability. Multi-group confirmatory factor analyses supported measurement invariance across Indonesian and Japanese participants. Data were analyzed using multivariate analysis of variance, hierarchical regression, and two-way analysis of variance. Indonesian participants reported significantly higher positive relationship-building ability and problem-solving ability than Japanese participants, whereas no cross-national differences were found in self-esteem or readiness for parenthood. Regression analyses indicated that positive relationship-building ability and self-esteem significantly predicted readiness for parenthood. In contrast, problem-solving ability and age did not uniquely predict readiness after controlling for other variables. No significant gender differences or gender-by-country interaction effects were observed. These findings suggest that relational competence and self-evaluative resources play central roles in shaping normative readiness for parenthood among emerging adults.

Competitive Adsorption and Structural Reinforcement Synergy Stabilizes High‐Voltage Quasi‐Solid‐State Batteries

ABSTRACT Quasi‐solid‐state batteries (QSSBs) employing high‐voltage cathodes promise high energy density and safety, yet suffer from unstable cathode/electrolyte interfaces and cathode degradation. Here, we propose a competitive adsorption and structural reinforcement synergy (CASR) strategy to address these challenges. Specifically, a Cu‐centered self‐adsorption molecule is incorporate into the polymer electrolyte, which preferentially adsorbs at the cathode/electrolyte interface through competitive adsorption against solvent molecules, thereby reducing the solvent content on the cathode surface while promoting anion enrichment. This process induces the formation of a uniform F‐rich cathode/electrolyte interphase with a LiF‐rich outer layer and an inner layer containing Cu─F bonds, thereby effectively suppressing cathode degradation. Cathode structural stability is further reinforced through dynamic Cu doping into TM‐deficient lattice sites during cycling. Under low‐loading coin‐cell conditions (2.0 mg cm −2 ), the resulting Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 QSSBs retain 80% of their initial capacity after 400 cycles at 4.6 V, and achieve 80% capacity retention over 1000 cycles under 10C and 4.5 V. A 1 Ah‐level pouch‐cell tested under 4.3 V and 1C charge/0.5C discharge conditions supports the potential of the CASR strategy. This work provides a promising pathway for synchronously stabilizing cathode/electrolyte interface and cathode structure in high‐voltage QSSBs.

Fetal programming is associated with candidate lipidomic signatures in skeletal muscle of Nellore beef cattle offspring

An Associative Pathway Enables Highly Controlled Ring‐Opening Polymerization of Cyclosiloxane with ppm‐Level Organocatalyst

ABSTRACT Precise control over molar mass and structure of polysiloxane is critical for its applications. Here, we report ring‐opening polymerization (ROP) of cyclotrisiloxane using anionized 1,3‐diphenylurea (UA1) as the catalyst. With a bulky tetra‐ n ‐butylammonium counterion, UA1 shows significantly higher activity than the one with an alkali metal counterion. Almost 100% monomer conversion can be reached in minutes at catalyst loadings of 5–100 ppm (TOF up to 52,000 h −1 for D 3 ). The obtained polydimethylsiloxane has well‐defined structure, controlled molar mass (2 to 140 kg mol −1 ), and low dispersity (1.06–1.18). Calculations reveal that both silanol species and the monomer are hydrogen‐bonded with the catalyst. The dominance of this associative pathway facilitates ring opening and prevents the formation of overly active (dissociated) silanolate anion, thus ensuring high efficiency and selectivity. The catalyst is also applicable to the ROP of non‐strained cyclotetrasiloxane (D 4 ), with molar mass reaching as high as 1,660 kg mol −1 . This study paves the route for efficient and controlled synthesis of polysiloxane materials using minimum amount of simple organocatalyst.

Synthesis and structural characterization of deuterium-labeled human tear film lipids and initial assessment of their potential as standards for lipidomic profiling work

Modulating Lewis Acidity of Covalent Organic Frameworks to Boost Li ⁺ Transport

ABSTRACT Solid polymer electrolytes offer a promising route to safer lithium metal batteries, but strong Li + –TFSI – coupling and insufficient salt dissociation limit their room‐temperature conductivity. Introducing Lewis acidic sites to competitively bind TFSI – can release Li + , yet the relationship between local Lewis acid–base regulation and ion transport remains unclear. Here, we tune the local Lewis acid–base environment of olefin‐linked pyridinium ionic covalent organic frameworks by exchanging counteranions from Br – to BF 4 – , PF 6 – , and TFSI – . Comprehensive results show that charge‐delocalized, weakly coordinating counteranions reduce screening of pyridinium cations, enhancing effective Lewis acidity and weakening Li + –TFSI – coupling. Consequently, ICOF‐TFSI@PVDF‐HFP achieves an ionic conductivity of 9.1 × 10 – 4 S·cm – 1 together with a Li + transference number of 0.81. The electrolyte enables stable Li||Li cycling over 6500 h, retaining 84.3% capacity after 650 cycles at 1 C in Li||LFP cells and 81.7% after 400 cycles at 1 C in Li||NCM90. Molecular dynamics, Raman spectroscopy, and operando characterizations confirm enhanced salt dissociation, regulated interfacial chemistry, dendrite suppression, and mitigated microcracking in high‐Ni cathodes. This study defines local Lewis acid–base regulation as a molecular design strategy for SPEs featuring fast Li + transport and robust interfacial stability.

Elucidating the molecular basis of Brunner syndrome: how clinically relevant mutations disrupt serotonin binding and active-site stability in monoamine oxidase A

Abstract Monoamine oxidase A (MAO-A) is a key enzyme responsible for serotonin degradation and mutations in the MAOA gene are associated with impaired enzymatic function and neuropsychiatric disorders, including Brunner syndrome. Although previous studies have demonstrated that such mutations reduce catalytic efficiency, their effects on substrate binding remain poorly understood. Here, we employed an integrated computational approach combining molecular docking, molecular dynamics simulations, and MM-GBSA binding free energy calculations to investigate the impact of four clinically relevant MAO-A variants (C266F, V244I, E446K, and R45W) on serotonin binding and active-site stability. Using a one-substrate, multiple-variant framework, we systematically compared disease-associated MAO-A variants and identified both shared and mutation-specific mechanisms affecting ligand recognition. All investigated mutants exhibited reduced serotonin binding affinity relative to the wild-type enzyme, as reflected by positive ΔΔ G values. Structural and energetic analyses revealed that this loss of affinity does not arise from major conformational changes but from mutation-induced perturbations of protein dynamics. Increased flexibility of second-shell residues promoted enhanced breathing of the binding pocket, leading to greater solvent-accessible surface area and increased water penetration into the active site. Consequently, the hydrophobic environment required for efficient substrate stabilization was compromised, weakening key hydrogen-bonding and electrostatic interactions. Residue-level energy decomposition identified unfavorable electrostatic contributions involving the FAD cofactor and active-site residues such as Tyr444 and Gln215 as major determinants of reduced binding affinity. Overall, our results demonstrate that mutation-induced changes in protein dynamics, hydration, and electrostatics collectively impair serotonin binding in MAO-A, providing molecular-level insight into the functional consequences of Brunner syndrome-associated mutations.

Shape‐Complementary DNA Scaffold for Programmable Functionalization of Symmetric Protein Assemblies

ABSTRACT The precise programming of bond valency, interaction strength, and spatial positioning within protein assemblies represents a significant step toward addressable functionalization, affording refined control over pattern recognition, cooperative behavior, and structural self‐organization. Here, we introduce a generalizable strategy to regulate the valency of symmetric protein assemblies through a shape‐complementary DNA scaffold. We demonstrate the controlled transfer of streptavidin–DNA conjugates from a ring‐shaped DNA nanostructure to a recombinant tobacco mosaic virus (TMV) disk. This mechanism specifies the number, sequence identity, and spatial arrangement of DNA motifs along the disk periphery, thereby enabling site‐specific addressability for DNA‐mediated binding and functional labeling. Leveraging the intrinsic programmability of DNA nanostructures, this strategy establishes a versatile platform for high‐fidelity valency engineering across diverse protein modules, with potential applications in biomedical and bioengineering.