Bioorthogonal reactions, both in vitro and in vivo, show great promise in fluorescent proteins labelling and for the development of bioorthogonal anticancer therapies. In this work, we focus on palladium-catalysed deprotection chemistry. Despite its potential, many questions remain unanswered. The most critical issues include the long-term stability of the palladium catalysts in biological milieu, the lack of efficient methods of reaction monitoring etc. Herein, we report the design of palladium catalyst containing phosphorus, arsenic, and antimony ligands. The catalytic activity has been evaluated for up to 7 days in vitro in the presence of bovine serum and for up to 9 h in living cells. Catalyst´s performance was assessed in the presence of cysteine and glutathione, as well as the abiotic thiophenol. The catalytic activity was measured using 14 different fluorescent probes, likely the largest probe library used to date. Furthermore, we have evaluated the cellular retention of fluorescent probes used for the detection of catalysts activity, revealing that most probes or fluorescent products are poorly retained in cells, thereby limiting long-term monitoring of the catalytic activity in physiological conditions in vivo. The results show that triphenylantimony is unparalleled ligand with respect to catalyst longevity under bioorthogonal conditions as well as in the tolerance to thiols. Long-term experiments show that propargylethers are excellent probes in vitro while allylcarbamates are more useful for in vivo studies. Our results also indicate that each probe (or prodrug) - catalyst couple is unique, and a search for a universal catalyst might be futile.
Characterizing protein-drug interactions at the atomic level is challenging partly because small molecules can be difficult to detect within large biomolecular complexes. We have developed a strategy to introduce NMR-active isotopic 15N labels into derivatives of bevirimat (BVM), a triterpenoid inhibitor of HIV-1 maturation. Isotopically labeled compounds were synthesized through concise and efficient routes using commercially available, isotopically enriched building blocks. Three 15N-labeled BVM derivatives were prepared to be used as molecular probes to investigate HIV-1 protein interactions. These labeled compounds enable site-specific 15N detection of the inhibitor in both solution and solid-state NMR experiments, which will be useful to obtain molecular-level insight into the interactions between BVM derivatives and its target HIV-1 Gag protein. Synthetic incorporation of NMR-active isotopes produces chemical probes for atomic-level analysis of next-generation HIV-1 therapeutics derived from BVM and can be applied to other derivatives of betulinic acid with various medical applications.
Elucidating drug-target interactions within native biological environments is critical for rational drug design and personalized medicine. While photoaffinity labeling (PAL) serves as a powerful tool for capturing these transient interactions, conventional photoactivation by UV light suffers from phototoxicity, limited penetration, and low yields. Advances in visible-light photocatalysis provide new opportunities, yet current strategies often rely on direct catalyst conjugation to the drug, introducing steric and physicochemical perturbations that can compromise native binding affinity. Moreover, the photocatalytic activation of alkyl diazirines, despite their widespread utility in PAL, has remained largely unexplored. Here we report a photocatalysis-enhanced photoaffinity labeling (PE-PAL) platform that activates bioorthogonal alkyl diazirine probes using separate iridium photocatalysts under blue light. By employing lipid- and peptide-modified iridium bioconjugates, PE-PAL achieves efficient labeling at submicromolar catalyst loading with enhanced biocompatibility, enabling in situ drug analysis via cellular imaging and proteome profiling. We further extended this platform to extracellular vesicle (EV) analysis by integrating probe-mediated enzymatic amplification with nanoplasmonic resonators to directly profile drug-target interactions in clinical blood samples. From microliter-scale samples, we achieved sensitive, multiparametric analysis of disease-associated EV labeling indices, demonstrating the translational potential of PE-PAL for EV-based liquid biopsy.
Persistent high-risk human papillomavirus (HPV) infection is a major cause of cervical carcinogenesis, yet current diagnostic methods - particularly colposcopy with nonspecific dyes - lack the precision needed for early-stage precancerous lesion detection. To address this gap, we developed a luminescent nanoprobe platform based on lanthanide-doped upconversion nanocrystals for HPV E7 oncoprotein detection, featuring three key advancements: (1) The nanoprobes exploit long luminescence lifetimes and near-infrared (NIR) emission to minimize background autofluorescence and enhance tissue penetration, while epitope -specific binding to E7 antigens ensures high target selectivity. (2) A homogeneous detection scheme, defined as the final solution-phase fluorescence reading obtained after proteolytic digestion, wherein proteolysis triggers cell lysis and probe release, enables precise fluorescent signal acquisition with a detecting limit of 5 cells/well, while preserving probe integrity for potential reuse. (3) A multichannel targeted imaging strategy suppresses tissue scattering artifacts, significantly improving early-stage lesion detection rates (p < 0.001). This work establishes a novel HPV diagnosis platform with enhanced sensitivity and clinical detection performance.
Buckling of a transesophageal echocardiography (TEE) probe is a rare but potentially life-threatening complication that carries a significant risk of esophageal perforation. We report 3 cases of buckled TEE probes that were promptly recognized, diagnosed, and managed using multimodal imaging. In each instance, the location of the buckled probe was confirmed with bedside imaging. Subsequently, the patient was taken to the interventional suite for advancement of the probe to the stomach under fluoroscopic guidance. Finally, the buckled TEE probe was straightened and removed successfully from the patient without difficulty. Early recognition of buckled TEE probes and employment of a structured, algorithmic management approach are essential to optimizing outcomes and preventing associated morbidity and mortality. Buckling of the TEE probe requires a high index of suspicion and prompt diagnosis to prevent catastrophic complications such as esophageal perforation. Advancement of the TEE probe in the stomach under fluoroscopic guidance facilitates straightening and removal of the probe without the risk of esophageal perforation.
Traditional dynamic light scattering (DLS) immunosensors rely on antigen-antibody interactions to directly trigger DLS probe aggregation, in which immune recognition and signal transduction are tightly coupled. However, the limited aggregation efficiency of DLS probes caused by suboptimal binding affinity of antigen-antibody interactions and inefficient target valency restrict the sensitivity of DLS immunosensors. Herein, we introduce a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC)-amplified DLS immunosensor (CAD-immunosensor) that decouples immune recognition from click chemistry-driven aggregation. In this strategy, antigen-antibody binding enables specific target recognition, while CuAAC independently drives covalent aggregation of immunocomplexes through a polyvalent protein crosslinker. The valency and spatial configuration of the protein crosslinker were examined to improve the kinetics and efficiency of immunocomplex aggregation. Owing to the irreversibility of the click chemistry reaction, the aggregation efficiency of DLS probes is significantly increased, leading to a remarkable enhancement in the sensitivity of the CAD-immunosensor for detecting staphylococcal enterotoxin A with a limit of detection of 0.70 pg mL-1, representing 560-fold and 2986-fold sensitivity improvements over conventional DLS immunosensor and enzyme-linked immunosorbent assay (ELISA). Furthermore, the sensitivity of the developed CAD-immunosensor for detecting malachite green is also increased by 3675-fold compared to the ELISA method. The test time is reduced from 90 min with ELISA to 25 min with the CAD-immunosensor, and sample preparation is significantly simplified, especially for malachite green detection in fish and shrimp samples. Collectively, the sensing performance of this DLS immunosensor highlights its strong potential for ultrasensitive detection of trace analytes, characterized by enhanced sensitivity, reduced detection time, and robust operational performance.
Electrophysiological signals are fundamental to elucidating the functional states and pathological mechanisms of the cardiac and nervous system. Yet, conventional techniques are constrained by inherent trade-offs between high-throughput capabilities, signal-to-noise ratio (SNR), and long-term stability. To address these challenges, field-effect transistor (FET)-based electrophysiological sensors have gained prominence as a powerful platform for cardiac and neural monitoring, distinguished by their exceptional sensitivity, low intrinsic noise, and superior spatiotemporal resolution. Here, we present a comprehensive overview of recent advances in this field, differentiating between planar and three-dimensional architectures to highlight distinct design strategies and applications. Specifically, planar configurations leverage rigid substrates for high-density integration and in vitro electrophysiological analysis, while flexible planar FETs, including graphene and organic transistors, enable conformal wearable and implantable monitoring. Conversely, three-dimensional configurations leverage nanoscale probes or mesh scaffolds to achieve intimate cell-device interfaces, enabling high-fidelity intracellular recording. Beyond device geometry, the integration of emerging materials, including graphene and organic semiconductors, is critically examined, along with the material, interfacial, and device-level factors that govern noise, SNR, and long-term sensing stability. The review concludes with an outlook on current challenges and future opportunities, emphasizing chronic biointerfacing, scalable integration, and reliable in vivo operation as key steps toward clinical translation in cardiology and neuroscience.
C-reactive protein (CRP) is a key biomarker for both infectious diseases and cardiovascular and cerebrovascular disorders. Thus, accurate full-range quantification is critical for early screening and timely intervention. However, limited sensitivity in conventional lateral flow immunoassays (LFIAs) and aggregation-induced quenching in traditional fluorescent probes collectively restrict analytical performance. In this work, a fluorescent LFIA platform based on P(St-AA)@AIENPs is established via an interfacial confinement-assisted loading strategy, enabling effective incorporation of aggregation-induced emission (AIE) luminogens into a poly(styrene-acrylic acid) matrix and delivering a detection limit of 0.66 ng/mL, a broad working range of 0-2000 ng/mL, high specificity, and strong correlation with ELISA (R2 = 0.995) within a 15 min assay. Overall, this platform offers a rapid, accurate, and portable solution for full-range CRP detection. It is particularly suitable for community-level screening and home-based testing, supporting improved disease management and a reduced public healthcare burden.
Pair density modulation is a phenomenon recently observed in exfoliated flakes of iron-based superconductors, in which the superconducting gap oscillates strongly with the same periodicity as the underlying crystalline lattice. We propose a model that explains this modulation in systems with broken intra-unit-cell symmetries through the emergence of nematic superconductivity, which further breaks the four-fold rotation symmetry. This results in a sublattice texture on the Fermi surface, aligned with the anisotropic superconducting gap of the nematic s± + d state. This gives rise to distinctive gap maxima and minima located on the two inequivalent iron sublattices while still being a zero-momentum pairing state. We discuss how further investigation of such modulations can give insight into the nature of the superconducting pairing, such as the signs of the order parameters and visualization of a phase transition to a mixed two-component state using local probes.
Dermal interstitial fluid (ISF) has emerged as the leading frontier for real-time molecular monitoring due to its rapid equilibration with blood and its role in carrying biomarkers that may reflect health status. To access ISF, we and others have developed microneedle sensor arrays, composed of microscopic probes that penetrate the epidermis painlessly to reach the dermis. These sensors, combined with wearable electronics, enable wireless, real-time molecular monitoring in the body. Previous studies have used enzyme-based microneedle sensors to monitor metabolites like glucose and lactate, while aptamer-based sensors have been applied for therapeutic drug monitoring. In this work, we expanded the application of aptamer-based microneedle sensors to evaluate the effect of protein binding on molecular transport from blood to ISF. Specifically, we monitored two antibiotics (vancomycin and tobramycin), the amino acid metabolite phenylalanine, two antineoplastics (irinotecan and doxorubicin), and a protein biomarker (platelet-derived growth factor, PDGF). To enhance measurement accuracy, we developed a multichannel sensor platform with magnetic attachment for reliable sensor placement in rodents. Our measurements reveal that small molecules with a significant "free" fraction in plasma (<70% protein binding), like vancomycin, tobramycin, and phenylalanine, transport efficiently into the dermis ISF and are detectable by microneedle sensors. Conversely, molecules that exist mostly protein bound, such as irinotecan and doxorubicin, reach ISF concentrations well below the limit of detection of benchmark aptamer-based sensors. Additionally, we demonstrate the first successful real-time measurement of PDGF-BB transport (∼25 kDa for the homodimer) from blood to ISF, highlighting the potential of microneedle sensors for tracking larger biomolecules and broadening the scope of real-time molecular health monitoring.
Ultrasound has emerged as a versatile, non-invasive imaging technique in dermatology, offering real-time, high-resolution visualization of cutaneous structures. By employing high- and ultra-high-frequency probes, skin ultrasound enables detailed assessment of the epidermis, dermis, and subcutaneous tissue, while Doppler modalities provide complementary information on vascularity. This review synthesizes current evidence on the role of ultrasound across the spectrum of dermatologic conditions, including malignant and benign tumors, inflammatory skin disorders, connective tissue diseases, and cosmetic interventions. In skin cancer, high-frequency ultrasound supports preoperative planning by estimating lesion depth, margins, and risk stratification, with particular value in basal cell carcinoma, squamous cell carcinoma, and melanoma. In benign tumors such as epidermal cysts and lipomas, sonographic features help avoid unnecessary invasive procedures. Ultrasound also refines disease staging and monitoring in chronic inflammatory dermatoses, notably hidradenitis suppurativa, psoriasis and psoriatic arthritis, while enabling quantification of fibrotic involvement in systemic sclerosis and morphea, besides assessing the degree of inflammatory activity. Beyond clinical dermatology, ultrasound provides critical guidance in aesthetic medicine, enhancing the safety and precision of filler injections and facilitating early detection and management of complications. Recent advances include integration with dermoscopy, and artificial intelligence for automated disease classification, which promise to reduce operator dependency and improve reproducibility. Taken together, these findings highlight the pivotal role of skin ultrasound as a diagnostic and therapeutic tool with a growing range of applications in dermatological and cosmetic practice.
Laser interstitial thermal therapy (LITT) is a novel and effective treatment for malignant glioma patients who could not undergo surgical resection. Preoperative planning for better tumor coverage and less probe use is a critical step of LITT's success, which can be challenging for surgeons as different constraints need to be considered. Here we proposed an automatic algorithm to plan trajectory combination for LITT, extending previous studies on LITT that used only one probe for treatment. Furthermore, we combined iterative optimization with Lagrangian relaxation and thus achieved both mathematic optimality and solving efficiency, which existing ablation planning research may fail to balance. The planning algorithm was evaluated in 16 cases of tumors and was compared with surgeon's planning result. In all cases our planning result achieved an average ablation rate of 99.83% and satisfied multiple constraints, outperforming the manual planning in probe usage and extent of ablation. By solving the relaxation model, our proposed method proved to be capable of reducing the number of probes to minimum with an average time cost of 39.73 seconds.
Cryopreservation of testicular tissue is crucial for germplasm banking in canine breeding programs, conservation of endangered canids, and veterinary oncology. However, optimal methods for canine testicular tissue remain underexplored due to challenges like ice crystal formation in slow freezing and cryoprotectant (CPA) toxicity in vitrification. This study compared automated slow freezing (ASF) and solid surface vitrification (SSV) for preserving histo-architecture and cellular function in testicular tissue from pubertal dogs. Testes from 15 pubertal dogs were fragmented into 5×5×5 mm pieces, distributed into control (CG), SSV, and ASF groups, cryopreserved, stored in liquid nitrogen for 15 days, thawed, and analyzed. Fluorescent probes were used to assess mitochondrial membrane potential (JC-1), reactive oxygen species (ROS), and lipid peroxidation (LPO). Histological and histomorphometric evaluations were employed to examine tissue structure. SSV better preserved mitochondrial function (JC-1 ratio: 0.64 ± 0.05 vs. 0.43 ± 0.02 in ASF) and reduced ROS (0.56 ± 0.04 vs. 0.96 ± 0.06). CG showed highest LPO (77.15 ± 0.77). ASF had higher scores for spermatogonia/Sertoli distinction (2.26 ± 0.10 vs. 1.30 ± 0.09), nuclear visualization (2.73 ± 0.08 vs. 1.26 ± 0.10), and condensation (2.40 ± 0.09 vs. 1.30 ± 0.09), but smaller tubule diameter (119.58 ± 4.45 vs. 150.82 ± 5.19 μm) and greater basal membrane retraction (48.21 ± 2.36 vs. 32.64 ± 2.16 μm). SSV is superior for canine testicular tissue cryopreservation based on mitochondrial function, oxidative stress, and structural integrity.
Expansion microscopy (ExM) has revolutionized super-resolution imaging in cell biology due to its simple and inexpensive workflow. The use of ExM has revealed several novel insights into the nanoscale architectures of cellular protein complexes, especially the microtubule cytoskeleton in model and non-model systems. Despite tremendous progress in expansion microscopy protocols that preserve cellular ultrastructure (U-ExM), compatible probes for imaging actin isoforms with U-ExM are still lacking and have hindered the study of diverse actin isoforms and networks across model systems. Here, we use IntAct, an internally tagged actin that incorporates into cellular actin networks, to develop and optimize U-ExM for diverse actin structures in yeast, mammalian cells, and primary neurons. Using ALFA-tagged IntAct variants, we achieve robust visualization of actin patches, cables, and rings in yeast, as well as diverse actin architectures including the cortex, stress fibers, filopodia, and lamellipodia in mammalian cells at improved resolution. In primary hippocampal neurons, IntAct efficiently labels actin throughout the soma and neuronal projections, revealing strong enrichment at dendritic spines and synaptic boutons. Notably, we observe a periodic organization of F-actin along axons consistent with the membrane-associated periodic cytoskeleton, thereby resolving the periodic, sub-diffraction actin ring organization. We also detect transient nuclear actin filaments using IntAct-U-ExM underscoring the advantages offered by our approach to image understudied actin structures. Overall, we demonstrate the effectiveness of IntAct-U-ExM for performing super-resolution imaging of various actin structures in an isoform-specific manner and highlight the potential of IntAct to study the nanoscale organization of diverse actin cytoskeletal networks across species.
Among the family of intercalated transition-metal dichalcogenides (TMDs), Fe_{x}NbS_{2} is found to possess unique current-induced resistive switching behaviors, tunable antiferromagnetic states, and a commensurate charge order, all of which are tied to a critical Fe doping of x_{c}=1/3. However, the electronic origin of such extreme stoichiometry sensitivities remains unclear. Combining angle-resolved photoemission spectroscopy (ARPES) with density functional theory (DFT) calculations, we identify and characterize a dramatic eV-scale electronic restructuring that occurs across the x_{c}. Moment-carrying Fe 3d_{z^{2}} electrons manifest as narrow bands within 200 meV of the Fermi level, distinct from other transition metal intercalated TMD magnets. These states strongly hybridize with itinerant electrons in the TMD layer and rapidly lose coherence above x_{c} due to correlation-driven effects. This sudden quasiparticle decoherence collapses the Fe-Nb hybridization, which explicitly suppresses the out-of-plane effective Fe-Fe exchange interaction, driving the transformation of the magnetic ground state from an antiferromagnetic stripe phase to a zigzag phase. These observations resemble the exceptional electronic and magnetic sensitivity of strongly correlated systems, and demonstrate that quantifying orbital-specific hybridization via ARPES offers an alternative pathway to evaluate effective magnetic exchange in metallic magnets, complementing inelastic neutron and resonant x-ray scattering probes.
Previous studies using solvatochromic dyes as probes of diluted and succussed solutions have indicated that potencies produce an electric field and are also nullified by having a weak electric current passed through them. The objectives of the current study were to build and expand on these observations. In particular, it has been proposed that if potencies produce their own electric field, this is likely due to the presence of separated charges. On application of an electrical current these charges are predicted to recombine and in so doing emit light. A specially adapted single tube luminometer has been used to monitor photon emissions from potency solutions of Arsenicum album 10M (Ars 10M) and controls, using fluorescein to extend the detection range of the instrument. A sharp photon emission peak is detectable from solutions of Ars 10M on application of a 9v/18mA electric current. Potency solutions only show the peak on application of the electric current and control solutions show no peak. The presence of 10 µM fluorescein is necessary in order to see the emission peak. Calculations show the charge-pair concentration in solution is 10-14M, assuming one photon is emitted per charge-pair. For Ars 10M that has been subjected to an electric current, photon emission and loss of activity against the solvatochromic dye DMABR correlate. The sharp photon emission peak seen in solutions of Ars 10M, but not in control solutions, requires fluorescein to be present and indicates the photons emitted are in the ultraviolet range. The concentration of separate charge-pairs, calculated from the photon emission level, is approximately 10-14M. Their identity remains unknown at this time, but they appear to be responsible for the activity of Ars 10M, as determined by its action against DMABR, and by extrapolation its clinical activity.
Cervical cancer harbors a profoundly immunosuppressive tumor microenvironment (TME) that impairs innate and adaptive antitumor immunity and, critically, limits the efficacy of emerging radioimmunotherapy strategies. The NKG2D receptor-ligand axis-comprising the stress-inducible ligands MICA and MICB-constitutes a pivotal innate immune recognition interface whose surface expression on tumor cells determines susceptibility to NKG2D-armed effector cells and, by extension, dictates the targetability of radiolabeled NKG2D-directed probes for precision radionuclide therapy (RNT). Yet the mechanistic basis for NKG2D ligand dysregulation and its implications for radionuclide theranostics in cervical cancer remain poorly defined. This study integrated single-cell RNA sequencing (scRNA-seq) and experimental validation to comprehensively map the NKG2D-axis immune escape landscape in cervical carcinogenesis and to delineate its translational significance for precision RNT target selection and patient stratification. scRNA-seq datasets (GSM1551311 and GSM1551411) were processed using Seurat and Harmony for cell-type annotation, immune landscape characterization, and radionuclide target density profiling. Louvain clustering was performed at a resolution of 0.8 after evaluating multiple resolution parameters (0.4-1.2) using the clustree package to ensure stable cluster assignments. The top 20 principal components were retained for Uniform Manifold Approximation and Projection (UMAP) embedding based on elbow plot analysis. Harmony integration used default parameters (θ = 2 and λ = 1) with convergence assessed over 20 iterations. Doublet detection was performed using DoubletFinder (v2.0.3) with an estimated doublet rate of 4.0%; additionally, cells with >40% ribosomal protein gene reads were excluded. Batch correction quality was validated using the Local Inverse Simpson's Index, Adjusted Rand Index, and silhouette coefficient metrics. Real-time quantitative PCR and enzyme-linked immunosorbent assay (ELISA) quantified expression of four candidate RNT-relevant genes-MICA, MICB (NKG2D ligands; primary radionuclide targeting molecules), SUSD1 (immunosuppressive upregulator; potential RNT resistance mediator), and STAG3L1-in HeLa, SiHa, and normal HCerEpiC cell lines. Five independent biological replicates were performed per cell line, each with three technical replicates, following Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines. Shapiro-Wilk normality testing and Levene's test for homogeneity of variance were applied prior to all parametric analyses. Cervical cancer scRNA-seq profiles revealed significantly depleted cluster of differentiation 8 (CD8)+ T cells (mean difference: -0.12; 95% CI: [-0.16, -0.08]; Cohen's d = 1.45) and natural killer (NK) cells (Cohen's d = 1.12), with increased CD25+ regulatory T cells (+0.08; 95% CI: [+0.05, +0.11]), establishing an RNT-unfavorable immunosuppressive TME. Comparative benchmarking against RNT-responsive tumor types, neuroendocrine tumors and prostate-specific membrane antigen (PSMA) positive prostate cancer, confirmed that cervical cancer exhibits a combination of reduced target surface density, depleted NKG2D-effector populations, and enriched immunosuppressive subsets collectively predictive of attenuated RNT efficacy. Experimental validation confirmed dramatic downregulation of MICA (HeLa: 0.44 ± 0.07 relative expression, p < 0.001, n = 5) and MICB (HeLa: 0.51 ± 0.09, p < 0.05), translating to markedly reduced MICA protein secretion (124.3 ± 18.5 pg/mL in HeLa versus 285.4 ± 31.2 pg/mL in controls, p < 0.01). Concurrently, SUSD1 was markedly upregulated (HeLa: 2.28 ± 0.25-fold; protein 3.42 ± 0.45 ng/mg, p < 0.001, n = 5). Strong mRNA-protein correlations, r = 0.78-0.92, p < 0.001; computed from five independent biological replicates per cell line; coefficient of variation (CV) < 15% for all measurements, validated transcriptomic profiling as a reliable proxy for theranostic target protein density estimation. This integrative study reveals that MICA/MICB downregulation and SUSD1 upregulation converge to suppress NKG2D-mediated antitumor immunity in cervical cancer, creating an immune-cold TME that limits current immunotherapy and radionuclide targeting efficacy. The NKG2D ligand expression landscape mapped here delineates a precision RNT strategy: scRNA-seq-guided patient stratification, radiolabeled anti-MICA/MICB nanobody theranostic imaging to confirm surface target density, and combination radioimmunotherapy integrating MICA/MICB re-expression induction with targeted radionuclide delivery to selectively irradiate the NKG2D-ligand-negative tumor cell population.
Quantum spin liquids can arise from Kitaev magnetic interactions, and to exhibit fractionalized excitations with the potential for a topological form of quantum computation. This review surveys recent experimental and theoretical progress on the pursuit of phenomena related to Kitaev magnetism in layered and exfoliatable materials, which offer numerous opportunities to apply powerful techniques from the field of atomically thin materials. We primarily focus on the antiferromagnetic Mott insulator α-RuCl3, which exhibits Kitaev couplings and is readily exfoliated to single-or few-layer sheets, and thus serves as a test bed for developing probes of Kitaev phenomena in atomically thin materials and devices. We introduce the Kitaev model and how it is realized in α-RuCl3 and other material candidates; and cover α-RuCl3 synthesis and fabrication into van der Waals heterostructure devices. A key discovery is a work-function-mediated charge transfer that heavily dopes both the α-RuCl3 and proximate materials, and can enhance Kitaev interactions by up to 50%. We further discuss a wide range of recent results in electronic transport and optical and tunneling spectroscopies of α-RuCl3 devices. The experimental techniques and theoretical insights developed for α-RuCl3 establish a framework for discovering and engineering superior two-dimensional Kitaev materials that may ultimately realize elusive quantum spin liquid phases.
Interaction of gut microbiota (GM) with dietary sugars (glucose, sorbitol) and choline has been transversely implicated in the pathogenesis of multiple chronic diseases. Our aim was to develop functional PET imaging of GM, using a multi-tracer approach to capture bacteria classes involved in sugar fermentation and choline catabolism at their gastrointestinal (GI) location. Adult and young sex-balanced groups of mice underwent oral administration of [18F]FDG, [18F]FDS or [11C]choline ([11C]cho) and repeated PET imaging over 4-5 h. Antibiotics, probiotic or faecal microbiota transplantation (FMT) served to quantify the specific role and site of bacteria action. GM was sequenced ex-vivo; gut histology and metabolic profiles were assessed in subsets. [18F]FDG and [18F]FDS reflected caecum abundance of Clostridia and Bacteroidia fermenters, with [18F]FDG exhibiting strongest and broadest relations. Clearance of [11C]cho from small gut reflected Bacilli and Lactobacilli abundance. In vitro cultures supported these relationships. Urinary 11C-excretion was nearly abolished by antibiotics. PET imaging was able to differentiate and predict gut bacteria classes in mice receiving FMT from two age-extreme human donors. Urinary [18F]FDS excretion reflected small-gut goblet cell activation; high caecum [18F]FDG retention and small gut [11C]cho clearance predicted body glucose use and low systemic inflammation. Imaging of ingested probes is simple and effective to map GM characteristics in situ and the functional crosstalk with host processes in mice in real-time. Our data confirm that the GI ecosystem is highly diversified, pointing to small intestine and caecum GM as dominant players in gut-body handling of our target nutrients.
Sensor array technology achieves multiplexed identification of ion targets by generating unique "fingerprint" response patterns through interactions between multiple sensing units and the targets. This is attained by combining advanced sensing materials such as quantum dots (QDs), nanoclusters (NCs), metal-organic frameworks (MOFs), and molecular probes, coupled with pattern recognition using machine learning algorithms like K-nearest neighbors (KNN), decision tree (DT), and random forest (RF). However, existing reviews predominantly focus on single pollutant types, single sensing mechanisms, or single sensor materials, lacking comprehensive integration and systematic summarization of research from identification to application. To the best of our knowledge, this review establishes the first complete classification framework for sensor arrays utilized in the multiplexed identification of multiple ions. It is worth noting that we have also linked the identification of target ions to the resolution of practical problems-such as environmental risk assessment, emergency response to sudden pollution incidents, disease diagnosis, product brand identification, species identification and traceability of origin-thereby exploring the practical value of sensor array technology for ion identification in the prevention and control of pollution, as well as in the differentiation of macro-level product indicators. Moving forward, multifunctionalization of sensing materials, intelligent pattern recognition algorithms, and system integration will further advance the practical utility of sensor array technology in complex matrices, enabling more precise, rapid real-time monitoring and decision support.