Attentional bias to social media stimuli is moderated by fear of missing out among problematic social media users.

Background and aims: Previous evidence has indicated that problematic social media use (PSMU) is characterized by an attentional bias to social media icons (such as Facebook icons), but not to social webpages (such as Facebook webpages). They suggest that there may be other factors influencing attentional bias like fear of missing out (FoMO). But it remains unclear how FoMO moderates attentional bias in PSMU. This study aims to investigate whether PSMU show attentional bias for stimuli associated with social media, and how FoMO moderates on attentional bias among PSMU through experimental methods. Methods: Based on the Interaction of Person-Affect-Cognition-Execution (I-PACE) model, this study explored mechanisms of attentional bias to social media icons (such as WeChat) related to PSMU and further examined the role of FoMO in this relationship. Specifically, attentional bias patterns to social media icons of 62 participants (31 PSMU and 31 control group) were explored during a dot-probe paradigm combined with eye-tracking in Experiment 1, and attentional bias patterns to social media icons of another 61 individuals with PSMU with different FoMO levels was explored during a dot-probe paradigm combined with eye-tracking in Experiment 2. Results: Results revealed that individuals with PSMU had an attentional bias toward social media icons, demonstrated by attentional maintenance, and such bias such bias was moderated by FoMO negatively, demonstrated by attentional vigilance and maintenance in PSMU/high FoMO. Conclusion: These results suggest that attentional bias is a common mechanism associated with PSMU, and FoMO is a key factor on the development of PSMU.

π-π conjugated PDI supramolecular regulating the photoluminescence of imine-COFs for sensitive smartphone visual detection of levofloxacin.

As the contamination and enrichment in food chain of levofloxacin (LV) antibiotics have caused a significant threat to life safety, the instant detection of LV has become an urgent need. Here, a PDI-functionalized imine-based covalent organic framework (PDI-COF300) was prepared by the electrostatic self-assembly method as fluorescent probe for smartphone visual detection of LV, which exhibited excellent fluorescence quantum yield (82.68%), greater stability, high sensitivity with detection limit of 0.303 µM. Based on the results of molecular docking and Stern-Volmer equation, the LV detection by PDI-COF300 was mainly a static quenching process through π-π stacked hydrophobic interactions and fluorescence resonance energy transfer. Besides, PDI-COF300 was applied to LV detection in environmental medium and milk samples with recoveries from 85.56% to 108.34% and relative standard deviations <2.70%. This work also provided a new general strategy for using PDI-COF in smartphone devices and fluorescent papers for LV fluorescence detection and microanalysis.

Accurate and rapid mercury susceptibility detection in aquatic samples using fluorescent probe integrated rhodamine with pyridyl isothiocyanate.

Mercury, one of the various harmful metals, is particularly significant in affecting aquatic organisms, currently gaining more attentions and sparking discussions. In response to the limitations of traditional detections, fluorescent probes have emerged as a promising solution with some advantages, such as weaker background interference, shorter processing time, higher accuracy. Thus, a novel fluorescent probe, FS-Hg-1, has been developed for assessing mercury ion (Hg2+) concentrations in aquatic products. This probe displays specific recognition of mercury ions in fluorescence spectra. Notably, FS-Hg-1 exhibits a distinct color change to pink when combined with Hg2+ (with a 948-fold increase in absorption at 568 nm) and a substantial fluorescence change towards Hg2+ (361-fold increase, excitation at 562 nm, emission at 594 nm) in N, N-dimethylformamide. The probe boasts a detection limit of 0.14 µM and rapid reaction with Hg2+ within 10 s, showing an excellent linear correlation with [Hg2+] in the range of 0 to 10 µM. Through thorough analysis using FS-Hg-1, the results align with those from the standard method (P > 0.05), with spiked recovery rates ranging from 108.4% to 113.2%. With its precise recognition, low detection limit, and remarkable sensitivity, this fluorescent assay proves effective in mercury concentration determination in aquatic samples without interference. The potential of FS-Hg-1 is promising for speedy detection of residual Hg2+ and holds significance in ensuring food safety.

Visualizing lysosomes hypochlorous acid in Parkinson's disease models by a novel fluorescent probe.

Heightened oxidative stress is the principal driver behind the altered metabolism of neurotransmitters within the brains of Parkinson's disease (PD). Hypochlorous acid (HClO), a variant of reactive oxygen species (ROS), plays a crucial role in several lysosomal activities. An irregular concentration of HClO may result in significant molecular damage and contribute to the onset of neurodegenerative disorders. Despite this, the precise role of lysosomal HClO in PD remains unclear, due to its fast reactivity and low levels. This is further complicated by the lack of effective in situ imaging techniques for accurately tracking its dynamics. Therefore, it is of great significance to use effective tools to map the lysosomal HClO during the pathological process of PD. In this study, we propose a fluorogenic probe named Lys-PTZ-HClO for the specific and sensitive detection of HClO. Lys-PTZ-HClO exhibits features like a fast response time (10 s) and a low detection limit (0.72 µM). Benefiting from its superior properties, the probe was used to visualize the basal HClO levels, and the variation of HClO levels in lysosomal of living cells. More importantly, this probe was successfully applied for the first time to reveal increased lysosomal HClO in a cellular model of PD.

On the Resolution Limit of Electrohydrodynamic Redox 3D Printing.

Additive manufacturing (AM) will empower the next breakthroughs in nanotechnology by combining unmatched geometrical freedom with nanometric resolution. Despite recent advances, no micro-AM technique has been able to synthesize functional nanostructures with excellent metal quality and sub-100 nm resolution. Here, significant breakthroughs in electrohydrodynamic redox 3D printing (EHD-RP) are reported by directly fabricating high-purity Cu (>98 at.%) with adjustable voxel size from >6µm down to 50 nm. This unique tunability of the feature size is achieved by managing in-flight solvent evaporation of the ion-loaded droplet to either trigger or prevent the Coulomb explosion. In the first case, the landing of confined droplets on the substrate allows the fabrication of high-aspect-ratio 50 nm-wide nanopillars, while in the second, droplet disintegration leads to large-area spray deposition. It is discussed that the reported pillar width corresponds to the ultimate resolution achievable by EHD printing. The unrivaled feature size and growth rate (>100 voxel s-1) enable the direct manufacturing of 30 µm-tall atom probe tomography (APT) tips that unveil the pristine microstructure and chemistry of the deposit. This method opens up prospects for the development of novel materials for 3D nano-printing.

A ratiometric fluorescent probe for selective detection of hypochlorite (ClO-) and gallium (III) (Ga3+) ions in environmental and food samples.

Hypochlorite (ClO-) and gallium (Ⅲ) ions (Ga3+) have extensive applications in various human industries and daily activities. However, their inherent toxicity poses significant risks to environmental preservation and human well-being. Hence, the development of reliable and handy detection tools for ClO- and Ga3+ in the environment and food is crucial. In this study, a ratiometric fluorescent probe was prepared based on benzothiazolaldehyde and pyridine-2-carboxylic acid hydrazide, which exhibited exceptional performance characteristics for the selective detection of ClO- and Ga3+. These features include high specificity, low detection limits (0.28 µM for ClO-, 0.13 µM for Ga3+), mild pH conditions (pH 4-11 for ClO-, pH 6-11 for Ga3+), fast response time (within 30 s), as well as versatile applicability across different matrices such as water, soil, food, and plant samples. Additionally, this probe can be used with a smartphone color recognition app. The probe offers a convenient and effective tool for the detection of ClO- and Ga3+, demonstrating its potential application value in environmental monitoring and food safety.

A ratiometric fluorescence method for the detection of diquat by a large Stokes shift fluorescent probe.

Pesticide residues are currently a prominent concern for food safety, and the development of a rapid, convenient, and accurate method for detecting pesticide residues is crucial to ensure the quality of agricultural products. In this study, a small molecule fluorescent probe based on biphenyl disulfonic acid (BDSA) was designed and prepared, and a sensitive, specific, and rapid detection method for diquat (DQ) and paraquat (PQ) was developed. The fluorescent molecule (BDSA-NDA) was synthesized through amide reaction between BDSA and 1,8-naphthalic anhydride, which exhibited cyan fluorescence (480 nm) when excited at 305 nm in aqueous solution with a large Stokes shift (>150 nm). Diquat and paraquat were found to quench the fluorescence of the probe through internal filtration effect (IFE) and photoelectron transfer (PET). Moreover, diquat possessed a large conjugated structure that emitted fluorescence at 340 nm which was assembled into a pair of ratio fluorescence with BDSA-NDA. Under optimized experimental conditions, the developed method achieved detection limits of 0.003 mg/L for diquat and 0.202 mg/L for paraquat. Furthermore, it could identify paraquat doped in diquat formulations. Additionally, when applied to environmental water samples as well as rice and urine, this detection method demonstrated good recovery rates (water: 96.2-100.6 %, rice: 93.5-101.9 %, urine: 96-103.7 %), meeting actual sample detection requirements effectively. This work presents a novel approach for rapidly detecting diquat and paraquat residues which holds practical application value in areas such as pesticide residue analysis in foods, environmental or clinical samples.

Simple turn-on fluorescent probe for ultrafast and highly selective detection of hydrogen sulfide in aqueous solutions.

5H-Benzimidazo[1,2-c]quinazoline-6-thione (BI-QT), was synthesized as a benzimidazole-based probe to detect H2S. BI-QT exhibits a fluorescent "turn-on" response in DMSO/H2O (9:1, HEPES 10 mM, pH 7.4) upon the addition of H2S. The BI-QT probe can determine micromolar (0-600 µM) H2S concentrations in aqueous systems, with a detection limit of 1.12 µM. Interestingly, BI-QT exhibited an ultrafast response to H2S, with maximum intensity achieved almost instantly when exposed to H2S. BI-QT is largely unaffected by pH and responds reliably over the wide 4-11 pH range, which highlights its applicability to various physiological scenarios. UV-vis, fluorescence, and 1H NMR spectroscopic analyses investigated the sensing mechanism. The practicality of the probe was demonstrated using water samples and living cells.

Inhibition of Lysosomal Cathepsin A and Neuraminidase 1 Interaction by Anti-obesity Cyclic Peptide.

Chronic inflammation in adipose tissue is associated with metabolic disorders such as obesity and type 2 diabetes. Novel small molecules targeting adipocyte differentiation and fat accumulation offer potential for new anti-inflammatory and anti-obesity drugs. Here we show that the marine cyclic heptapeptide stylissatin A and its analogs (SAs) inhibit membranous neuraminidase 1 (Neu1) function by interacting with lysosomal protective protein cathepsin A (PPCA). Neu1 has been less explored as a therapeutic target due to the genetic defects leading to neurodegenerative disorders. However, unlike traditional neuraminidase inhibitors, SAs don't directly bind to Neu1 but modulate the molecular chaperone activity of PPCA. SAs caused degradation of perilipin 1 around lipid droplets and inhibited fat accumulation, along with decrease in membranous Neu1. Molecular docking and molecular dynamics simulations revealed that SAs interacted with activated PPCA at the Neu1 binding site. Focusing on this newfound protein-protein interaction inhibition mechanism could lead to the development of pharmaceuticals with fewer side effects.

Advances in the synthesis and applications of macrocyclic polyamines.

Macrocyclic polyamines constitute a significant class of macrocyclic compounds that play a pivotal role in the realm of supramolecular chemistry. They find extensive applications across diverse domains including industrial and agricultural production, clinical diagnostics, environmental protection and other multidisciplinary fields. Macrocyclic polyamines possess a distinctive cavity structure with varying sizes, depths, electron-richness degrees and flexibilities. This unique feature enables them to form specific supramolecular structures through complexation with diverse objects, thereby attracting considerable attention from chemists, biologists and materials scientists alike. However, there is currently a lack of comprehensive summaries on the synthesis methods for macrocyclic polyamines. In this review article, we provide an in-depth introduction to the synthesis of macrocyclic polyamines while analysing their respective advantages and disadvantages. Furthermore, we also present an overview of the recent 5-year advancements in using macrocyclic polyamines as non-viral gene vectors, fluorescent probes, diagnostic and therapeutic reagents as well as catalysts. Looking ahead to future research directions on the synthesis and application of macrocyclic polyamines across various fields will hopefully inspire new ideas for their synthesis and use.

Development and performance simulations of a soft X-ray and XUV split-and-delay unit at beamlines FL23/24 at FLASH2 for time-resolved two-color pump-probe experiments.

The split-and-delay unit (SDU) at FLASH2 will be upgraded to enable the simultaneous operation of two temporally, spatially and spectrally separated probe beams when the free-electron laser undulators are operated in a two-color scheme. By means of suitable thin filters and an optical grating beam path a wide range of combinations of photon energies in the spectral range from 150 eV to 780 eV can be chosen. In this paper, simulations of the spectral transmission and performance parameters of the filter technique are discussed, along with a monochromator with dispersion compensation presently under construction.

Super-resolution imaging lysosome vesicles and establishing a gallbladder-visualizable zebrafish model via a fluorescence probe.

Advanced probes for imaging viscous lipids microenvironment in vitro and in vivo are desirable for the study of membranous organelles and lipids traffic. Herein, a reaction-based dihydroquinoline probe (DCQ) was prepared via linking a diethylamino coumarin fluorophore with a N-methylquinoline moiety. DCQ is stable in low viscous aqueous mediums and exhibits green fluorescence, which undergoes fast autoxidation in high viscous mediums to form a fluorescent product with deep-red to near-infrared (NIR) emission, rendering the ability for dual-color imaging. Living cell imaging indicated that DCQ can effectively stain lysosomal membranes with deep-red fluorescence. Super-resolution imaging of lysosome vesicles has been achieved by DCQ and stimulated emission depletion (STED) microscopy. In addition, DCQ realizes multiple organs imaging in zebrafish, whose dual-color emission can perfectly discriminate zebrafish's yolk sac, digestive tract and gallbladder. Most importantly, DCQ has been successfully used to establish a gallbladder-visualizable zebrafish model for the evaluation of drug stress.

A sensitive benzothiazole fluorescent probe for the detection of γ-glutamyl transpeptidase activity and its application.

A sensitive benzothiazole fluorescent probe (PBZO) for the detection of γ-glutamyl transpeptidase (GGT) activity was developed. Based on the enzymatic hydrolysis of peptide bonds by glutamyl transpeptidase, it can be specifically recognized by PBZO. The PBZO has a good linear relationship with different gradients of GGT activity at the emission wavelength of 560 nm, the Stokes shift reached 215 nm, and the detection limit of GGT activity is 0.1644 U/ml. With the increase of GGT concentration in the probe solution, the color of the solution gradually changed from orange to dark yellow under the 365 nm UV lamp. The same color change was also observed on the probe test paper. In addition, there is a linear relationship between the GGT activity and the R-value of the probe solution. More importantly, the probe has a good recovery rate in serum. Therefore, this probe can be used as a convenient tool for detecting GGT activity.

Design of deep-red emissive forced intercalation-induced light-up peptide as an indicator for the HIV-1 TAR RNA-ligand assay: integration of benzo[c,d]indole-quinoline (BIQ) cyanine dye into Tat peptide.

We report on a deep-red emissive fluorogenic peptide probe for human immunodeficiency virus-1 (HIV-1) trans-activation responsive (TAR) RNA as an indicator for fluorescence indicator displacement (FID) assay. The probe design is based on the concept of the forced intercalation of thiazole orange (TO) dyes (FIT) on the peptide backbone, as recently proposed by our group, where the Q (glutamic acid) residue in the Tat peptide (RKKRR-Q-RRR) is replaced with TO as if it were an amino acid surrogate. Here, instead of green emissive TO, we utilized a deep-red emissive benzo[c,d]indole-quinoline (BIQ) cyanine dye developed previously by our group for imaging of nucleolar RNA in living cells. The developed 9-mer FIT peptide (RKKRR-BIQ-RRR; named BIQ-FiLuP) exhibits a significant off-on signaling ability for TAR RNA (λem = 660 nm, I/I0 = 130-fold, Φfree = 0.0009, Φbound = 0.052), and the dissociation constant Kd reaches ca. 1 nM. When used in FID assay, BIQ-FiLuP, like TO-based FiLuP, is able to distinguish between competitive and noncompetitive inhibitors, which has never been demonstrated with all previous indicators for TAR RNA. Deep-red emissive BIQ-FiLuP facilitates the evaluation of green to yellow emissive ligands without suffering from optical interference. The combination use with green emissive TO-based FiLuP (λem = 541 nm) would cover the examination of a wide range of fluorescent test compounds.

Modification of an AIE Fluorescent Probe for Monitoring the Polarity of Lipid Droplets Based on a series of Synthesized Aryl Naphthalizes.

Lipid droplets (LDs) are subcellular organelles that are dynamic and play a central role in energy homeostasis and lipid metabolism. They also contribute to the transport and maturation of cellular proteins and are closely associated with several diseases. The important role of the cellular microenvironment in maintaining cellular homeostasis. Changes in cell polarity, particularly in organelles, have been found to be strongly linked to inflammation, Alzheimer's disease, cancer, and other illnesses. It is essential to check the polarity of the LDs. A series of arylated naphthalimide derivatives were synthesized using the Suzuki reaction. Modification of synthesized aryl naphthalimides using oligomeric PEG based on intramolecular charge transfer (ICT) mechanism. A series of fluorescent probes were designed to target LDs and detect their polarity. Nap-TPA-PEG3 probe exhibited high sensitivity to polarity. The addition of oligomeric polyethylene glycol (PEG) to the probe not only significantly improved its solubility in water, but also effectively reduced its cytotoxicity. In addition, the probe exhibited excellent aggregation-induced luminescence (AIE) properties and solvent discolouration effects. Nap-TPA-PEG3 probe exhibited high Pearson correlation coefficient (0.957163) in lipid droplet co-localization in cells. Nap-TPA-PEG3 could be used as an effective hand tool to monitor cell polarity.

Near-Infrared Fluorescent Probe for the Detection of Cysteine.

Hemicyanine dyes are an ideal structure for building near-infrared fluorescent probes due to their excellent emission wavelength properties and biocompatibility in biological imaging field. Developing a near-infrared fluorescent probe capable of detecting cysteine (Cys) was the aim of this study. A novel developed fluorescent probe P showed high selectivity and sensitivity to Cys in the presence of various analytes. The detection limit of P was found to be 0.329 µM. The MTT assay showed that the probe was essentially non-cytotoxic. Furthermore, the probe was successfully used as cysteine imaging in living cells and mice.

Bodipy-Based highly sensitive hydrogen sulfide fluorescent probe and its fluorescence imaging in cells and zebrafish.

Hydrogen sulfide (H2S) is a crucial endogenous gasotransmitter that plays a role in various physiological and pathological processes. Therefore, accurate and rapid monitoring of H2S in organisms is highly significant for understanding the underlying pathological mechanisms and facilitating early diagnosis of related diseases. In this study, we developed a novel fluorescent probe, B-CHO-NO2, based on a bodipy fluorophore, which exhibits excellent sensitivity and selectivity towards H2S. The design of the probe exploits the nucleophilicity of H2S by introducing a formyl group as the ortho-participating moiety, significantly enhancing the reaction rate with H2S. In cellular and zebrafish models, the probe B-CHO-NO2 successfully achieved fluorescence imaging of endogenous and exogenous H2S. The development of probe B-CHO-NO2 provides a powerful tool for biological studies of H2S and diagnosis of related diseases.

Application of acid-activated near-infrared viscosity fluorescent probe targeting lysosomes in cancer visualization.

The higher viscosity and lower pH in lysosomes of cancer cells highlight their potential as biomarkers for cancer. Therefore, the development of acid-activated viscosity fluorescent probes is significant for the early diagnosis and treatment of cancer. Based on this, we have designed and synthesized a near-infrared fluorescent probe based on the 2-(2-hydroxyphenyl)benzothiazole (HBT) group, namely HBTH, to monitor the viscosity changes within lysosomes. It has been demonstrated that HBTH was extremely sensitive to viscosity, with a strong linear relationship between fluorescence intensity and log(viscosity) within the range of (logη) = 0-3.06 (a correlation coefficient of 0.98), proving its capability for quantitative viscosity measurement. In particular, the most obvious fluorescence enhancement of HBTH was only efficiently triggered by the combined effect of low pH and high viscosity. Furthermore, HBTH can rapidly localize to lysosomes by wash-free procedure at a low concentration (100 nM) and achieve high-fidelity imaging within 20 s. It can also monitor the dynamic processes of lysosomes in cells, viscosity changes under drug stimuli, and lysosomal behavior during mitophagy. Importantly, HBTH is capable of identifying tumors in tumor-bearing nude mice through in vivo imaging. These features make HBTH a powerful tool for the early diagnosis and treatment of cancer.

A novel "turn-on" NIR fluorescent probe based on benzothianone for the detection of palladium species and its application in cell and zebrafish.

The development of an efficient palladium probe holds significant application value, considering the detrimental impact of palladium contaminants on human health. Thus, it is critical to create a sensitive detection method. To this end, a fluorescent probe TM-TPA-Pd based on benzothianone structure was designed, using allyl carbonate as the Pd0 recognition unit. TM-TPA-Pd exhibited high sensitivity (1.4 eq), selectivity, near-infrared (NIR) fluorescence (798 nm), and low detection limit (0.46 µM) for Pd0 with a rapid "turn-on" fluorescence signal (5 min). Furthermore, TM-TPA-Pd has extremely low cytotoxicity and has been successfully applied to detecting cells and zebrafish, which has great potential for palladium detection in biological systems.

A Novel AIE-Active Salicylaldehyde-Schiff Base Probe with Carbazole Group for Al3+ Detection in Aqueous Solution.

A donor-acceptor Schiff-base fluorescent probe BKS with chelation enhanced fluorescence (CHEF) mechanism was designed and synthesized via benzophenone(Acceptor), salicylaldehyde and carbazole(Donor) for Al3+ detection, which exhibited typical aggregation-induced emission (AIE) characteristic. BKS probe could provide outstanding selectivity to Al3+ with a prominent fluorescence "turn-on" at 545 nm in a wide pH range from 2 to 11. By the Job's plot, the binding stoichiometry ratio of probe BKS to Al3+ was determined 1:1. The proposed strategy offered a very low limit of detection at 1.486 µM in THF/H2O(V/V = 1:4, HEPBS = 10 mM, pH = 7.40), which was significantly lower than the standard of WHO (Huang et al., Microchem J 151:104195, 2019)-(Yongjie Ding et al., Spectrochim Acta Mol Biomol Spectrosc 167:59-65, 2021) guidelines for drinking water. BKS probe could provide a wider linear detection range of 50 to 500 µM. Furthermore, the probe could hardly be interfered by other examined metal ions. The analysis of Al3+ in real water samples with appropriate recovery (100.72 to 102.85) with a relative standard deviation less than 2.82% indicated the accuracy and precision of BKS probe and the great potential in the environmental monitoring of Al3+.