Mitochondria-Targeted Ratiometric KLA-Tweezers for Fluorescence Imaging of Potassium Ions.

Intracellular potassium ions play a crucial role in cellular homeostasis associated with physiological and pathological processes. It is still challenging but definitely crucial to precisely and dynamically image subcellular K+. Herein, the first mitochondria-targeted DNA tweezers (KLA-tweezers) were developed for the fluorescence imaging of mitochondrial K+ with high selectivity and accuracy. The proposed KLA-tweezers consisted of two DNA double-crossover (DX) motifs, a K+-aptamer, and a mitochondria-targeted peptide (KLA) which was conjugated at the rear of DX arms via complementary base pairing. Upon contact with K+, the K+-aptamer experienced a conformational change from an open-chain G-rich sequence to a G-quadruplex with a compact conformation, which was reflected by the Förster resonance energy transfer process between Cy3 and Cy5 labeled at the end of the DX arms. The open and closed states of the tweezers before and after KLA modification were confirmed by gel electrophoresis and fluorescence spectra together with atomic force microscopy (AFM) and transmission electron microscopy (TEM) images, suggesting the KLA assembly had no effect on the morphology change. The proposed tweezers and KLA-tweezers showed low cytotoxicity, excellent selectivity, and good reversibility upon alternating addition of 18-crown-6 and K+. Besides, the KLA-tweezers exhibited outstanding stability and accurate mitochondria location ability. Upon stimulation of ATP or nigericin, intracellular fluorescence imaging of mitochondrial K+ dynamics was successfully achieved. This strategy has broad prospects as a general optical sensing platform for other metal ions or organelles in living cells.

A Controlled Clinical Study of Accelerated High-Dose Theta Burst Stimulation in Patients with Obsessive-Compulsive Disorder.

Background: Obsessive-compulsive disorder (OCD) is frequently treated using a combination of counseling, drugs, and, more recently various transcranial stimulation protocols, but all require several weeks to months for clinically significant improvement, so there is a need for treatments with faster onset. This study investigated whether an accelerated high-dose theta burst stimulation (ahTBS) protocol significantly improves the efficacy of OCD compared to traditional 1-Hz repetitive transcranial magnetic stimulation (rTMS) in the routine clinical setting. Method: Forty-five patients with OCD were randomized into two groups and treated with ahTBS or 1-Hz rTMS for 5 days. Patients were assessed at baseline at the end of treatment using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Results: After 5 days of treatment, there was a significant decrease in Y-BOCS scores in both groups (p < 0.001), and the difference between the two groups was not statistically significant (group × time interaction, F = 1.90, p=0.18). There was also no statistically significant difference in other secondary outcome indicators, including depression, anxiety symptoms, and response rate. However, the ahTBS group had a greater trend in response rate. Neuropsychological testing showed no negative cognitive side effects of either treatment. Conclusion: Accelerated high-dose TBS is as safe and has comparable short-term efficacy to traditional 1-Hz rTMS for the clinical treatment of OCD. Further research is needed to explore optimal ahTBS parameters, validate the utility of this treatment modality, and identify factors predictive of rapid clinical response to guide clinical decision-making. This trial is registered with NCT05221632.

Rapid On-Chip Isolation of Cancer-Associated Exosomes and Combined Analysis of Exosomes and Exosomal Proteins.

Exosomes are lipid bilayer extracellular vesicles secreted by various types of cells and inherit abundant molecular information from parental cells. Tumor-derived exosomes have been widely recognized as noninvasive biomarkers for early cancer diagnosis and surveillance, but the separation of intact exosomes and detection of exosomal proteins remain challenging. Herein, we proposed a microfluidic chip for specific exosome isolation, integrated with sensitive quantification by a novel PTCDI-aptamer signal switch strategy. To enhance the capture efficiency, an alternating drop-shaped micropillar array was designed to assist the capture of tumor-derived exosomes by Tim4-modified magnetic beads (Tim4 beads) on the chip. Following capture, a chelating agent can easily elute intact exosomes which were further used for profiling exosomal surface proteins by the multiplexed fluorescence turn-on approach. Profiting from the efficient on-chip enrichment of the Tim4 beads and superior fluorescence signal transduction strategy, the detection limit of the analysis platform for HepG2 exosomes is as low as 8.69 × 103 particles/mL with a wide linear range spanning 6 orders of magnitude. Meanwhile, the proposed platform could recognize subtle changes in protein levels on the exosomal surface from various cell lines. More importantly, this strategy is successfully applied to analyze exosomes in human serum to distinguish liver cancer patients from healthy individuals. Combined analysis of different types of biomarkers on the exosomal membrane surface can greatly improve the accuracy of cancer type identification and disease monitoring. We hope that this convenient, rapid, and sensitive platform may become a powerful tool in the field of exosome analysis and early cancer screening.

Trihexyltetradecylphosphonium chloride based ratiometric fluorescent nanosensors for multiplex anion discrimination.

Compared with the well-studied cations, the development of methods for anion detection is relatively slow due to the anion characteristics such as a complex geometry, strong hydration and a low charge density. Herein, a colorimetric and ratiometric fluorescent anion sensing platform based on trihexyltetradecylphosphonium chloride ([THTP][Cl]) was developed for the first time. Such nanosensors exhibited a pH response of 5-7 as well as a high selectivity to perchlorate. The selectivity behavior followed the Hofmeister series in which lipophilic anions were more readily co-extracted. To deviate from the Hofmeister series, anion ionophores should be introduced for selective complexation of the target anions. As a proof of concept, the organomercury compounds ETH9033 and ETH9009 were employed as model ionophores. The obtained nitrate- and chloride-selective [THTP][Cl]-based nanosensors demonstrated prominent colorimetric and spectroscopic transformations specifically induced by the anion species. The fluorescence (I675/I600) and absorbance (A650/A500) intensities versus the logarithm values of anion concentrations proved a high selectivity towards the major anion. The excellent performance such as high selectivity, good sensitivity and fast response times enabled the accurate determination of nitrate in mineral water. More importantly, through simply altering the ionophores, a pool of [THTP][Cl]-based anion-selective nano-optodes for extended targets could be achieved. The nanosensor shows great potential for anion determination in the environmental and biomedical fields.

Reliable Semantic Communication System Enabled by Knowledge Graph.

Semantic communication is a promising technology used to overcome the challenges of large bandwidth and power requirements caused by the data explosion. Semantic representation is an important issue in semantic communication. The knowledge graph, powered by deep learning, can improve the accuracy of semantic representation while removing semantic ambiguity. Therefore, we propose a semantic communication system based on the knowledge graph. Specifically, in our system, the transmitted sentences are converted into triplets by using the knowledge graph. Triplets can be viewed as basic semantic symbols for semantic extraction and restoration and can be sorted based on semantic importance. Moreover, the proposed communication system adaptively adjusts the transmitted contents according to channel quality and allocates more transmission resources to important triplets to enhance communication reliability. Simulation results show that the proposed system significantly enhances the reliability of the communication in the low signal-to-noise regime compared to the traditional schemes.

Anti-inflammatory Eudesmane Sesquiterpenoids from Artemisia hedinii.

Fourteen new eudesmane sesquiterpenoids (1, 3-5, 7-16) and seven known analogues were isolated from the whole plant of Artemisia hedinii. Their structures were elucidated by spectroscopic data analysis and comparison with published NMR data, and their absolute configurations were confirmed by X-ray diffraction experiments and TDDFT ECD calculation. Compounds 1-15 were identified as eudesmane acids, which represent a kind of lactone ring-opening eudesmane-type sesquiterpenes with an acetoxyl or a hydroxy group attached to C-9. Compounds 1 and 2, 5 and 6, and 7 and 8 are three pairs of epimers isomerized at C-3, C-5, and C-11, respectively. Compounds 1-9, 11-13, 15-19, and 21 could influence the proinflammatory phenotype of the M1 macrophage. Among them, compounds 5, 8, 9, 12, 16, and 19 consistently exhibited anti-inflammatory effects, as evidenced by downregulating classic pro-inflammatory cytokines TNF-α, IL-12, IL-6, and IFN-γ in LPS-induced primary bone marrow derived M1 macrophages.

Autologous platelet-rich plasma in the treatment of refractory wounds in cutaneous leukocytoclastic vasculitis complicated with hypertension (grade 2 moderate risk): A case report.

INTRODUCTION: Cutaneous leukocytoclastic vasculitis is an inflammatory variant of vasculitis with a variety of causes that only affects the skin. Its pathological manifestations include neutrophil infiltration and nuclear fragmentation. Clinically, it is characterised by a pleomorphic rash, including erythema, purpuric skin lesions, reticulocytosis, necrosis and ulceration. Once formed, local ulcerations are very difficult to heal. CASE PRESENTATION: A 46-year-old female was diagnosed with cutaneous leukocytoclastic vasculitis. The patient's legs exhibited ulcers with a black eschar on the surface. The largest wound was 4.5 × 4.0 cm and the deepest wound was 1.7 × 1.8 × 1.0 cm. The ulcers had been present for 6 months and did not exhibit signs of healing. Treatment was commenced with platelet-rich plasma, and the wounds healed within 1 month. CONCLUSION: Topical application of autologous platelet-rich plasma gel exerts beneficial effects in cutaneous leukocytoclastic vasculitis with regard to wound size reduction, and it induces granulation tissue formation. Platelet-rich plasma may represent a safe and cost-effective treatment for managing cutaneous wound healing to reduce the length of the recovery period.

Bifunctional Peptide-Conjugated Gold Nanoparticles for Precise and Efficient Nucleus-Targeting Bioimaging in Live Cells.

Real-time in situ imaging of organelles is increasingly important in modern biomedical analysis and diseases diagnosis. To realize this goal, organelle-targeting nanoparticles as one of the most commonly used technologies in subcellular sensing and imaging has attracted a lot of interest. The biocompatibility, specificity, and binding efficiency are especially critical for efficient organelle-targeting bioimaging. Gold nanoparticles (AuNPs) fabricated with bifunctional peptides constructed with both Au-binding affinity and nucleus-targeting ability were designed and examined for efficient nucleus-targeting bioimaging. Such a design is expected to achieve an oriented assembling of peptides by the medium of the Au-binding peptides specifically assembled on the surface of AuNPs, with the nucleus-targeting end open for accessibility. The bifunctional peptides showed strong binding affinity toward AuNPs and led to a binding capability ∼1.5 times higher than that of the bare nucleus-targeting peptides, ensuring good surface coverage of the nanoparticles for enhanced nucleus-targeting ability. Such fabricated AuNPs demonstrated over 90% cell viability after incubation for 24 h with HepG2 cells, which were highly biocompatible. Precise and efficient bioimaging of the nucleus was achieved for HepG2 cells by using the fabricated AuNPs as observed with a confocal laser scanning microscope, a dark-field/fluorescence microscope, and a transmission electron microscope. The high surface coverage and oriented binding pattern appeared to be a promising strategy for construction of organelle-targeting agencies.

Disposable Multi-Walled Carbon Nanotubes-Based Plasticizer-Free Solid-Contact Pb2+-Selective Electrodes with a Sub-PPB Detection Limit †.

Potentiometric plasticizer-free solid-contact Pb2+-selective electrodes based on copolymer methyl methacrylate-n-butyl acrylate (MMA-BA) as membrane matrix and multi-walled carbon nanotubes (MWCNTs) as intermediate ion-to-electron transducing layer have been developed. The disposable electrodes were prepared by drop-casting the copolymer membrane onto a layer of MWCNTs, which deposited on golden disk electrodes. The obtained electrodes exhibited a sub-ppb level detection limit of 10-10 mol·L-1. The proposed electrodes demonstrated a Nernstian slope of 29.1 ± 0.5 mV/decade in the linear range from 2.0 × 10-10 to 1.5 × 10-3 mol·L-1. No interference from gases (O2 and CO2) or water films was observed. The electrochemical impedance spectroscopy of the fabricated electrodes was compared to that of plasticizer-free Pb2+-selective electrodes without MWCNTs as intermediated layers. The plasticizer-free MWCNTs-based Pb2+-selective electrodes can provide a promising platform for Pb(II) detection in environmental and clinical application.

Ratiometric fluorescent pH nanoprobes based on in situ assembling of fluorescence resonance energy transfer between fluorescent proteins.

pH-dependent protein adsorption on mesoporous silica nanoparticle (MSN) was examined as a unique means for pH monitoring. Assuming that the degree of protein adsorption determines the distance separating protein molecules, we examined the feasibility of nanoscale pH probes based on fluorescence resonance energy transfer (FRET) between two fluorescent proteins (mTurquoise2 and mNeonGreen, as donor and acceptor, respectively). Since protein adsorption on MSN is pH-sensitive, both fluorescent proteins were modified to make their isoelectric points (pIs) identical, thus achieving comparable adsorption between the proteins and enhancing FRET signals. The adsorption behaviors of such modified fluorescent proteins were examined along with ratiometric FRET signal generation. Results demonstrated that the pH probes could be manipulated to show feasible sensitivity and selectivity for pH changes in hosting solutions, with a good linearity observed in the pH range of 5.5-8.0. In a demonstration test, the pH probes were successfully applied to monitor progress of enzymatic reactions. Such an "in situ-assembling" pH sensor demonstrates a promising strategy in developing nanoscale fluorescent protein probes. Graphical abstract Working principle of the developed pH sensor TNS; and FRET Ratio (I528/I460) as a function of pH under different protein feed ratios (mNeonGreen to mTurquoise2).