Search Results (1,221)

This study aimed to develop a reliable method for profiling reducing sugars in honey using capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). Reducing sugars were derivatized with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) in the presence of 2-picoline borane, a safer alternative to sodium cyanoborohydride. Key parameters influencing the derivatization efficiency—temperature, pH, incubation time, and reagent concentrations—were systematically optimized. The highest labeling efficiency for glucose, mannose, and maltose was achieved at 50 °C in 0.5 M citric acid with 0.1 M APTS, while fructose showed low reactivity due to its ketose structure. To reduce the background signal from excess reagents, three cleanup strategies were evaluated. Liquid–liquid extraction with ethyl acetate effectively removed unreacted APTS without significant analyte loss, whereas solid-phase extraction and microextraction caused substantial losses of hydrophilic sugars. The method showed good linearity (0.5–10 mM, R² > 0.994), precision (RSD 0.81–13.73%), and accuracy (recoveries 93.47–119.75%). Stability studies indicated that sugar standards should be stored at –20 °C. The method was successfully applied to the analysis of four nectar honeys—rapeseed, acacia, phacelia, and dandelion—revealing differences in glucose and fructose content related to botanical origin. The results confirm the suitability of CZE-LIF for sensitive and selective carbohydrate analyses in complex food matrices. Full article

Background/Objectives: The present study aimed to synthesize folate-conjugated poloxamers and develop polymeric micelles for the dermal delivery of irinotecan and alpha-mangostin for the treatment of melanoma using poloxamer 188 and poloxamer 184, which have never been synthesized with folate before. Methods: Poloxamer 188 and poloxamer 184 were synthesized with folate by esterification. The in vitro skin penetration enhancement of irinotecan- and alpha-mangostin-loaded folate-conjugated polymeric micelles was evaluated. The skin penetration pathway of folate-conjugated polymeric micelles was investigated by colocalization of multiple fluorescently labeled particles using confocal laser scanning microscopy (CLSM). Results: Folate-conjugated poloxamer 188 and poloxamer 184 were successfully synthesized. The prepared irinotecan- and alpha-mangostin-loaded folate-conjugated polymeric micelles from poloxamer 188 and poloxamer 184 had particle sizes of approximately 180 and 150 nm, respectively, indicating a positive charge with a narrow size distribution which could be easily taken up into cells. An in vitro skin penetration study revealed that folate-conjugated polymeric micelles from poloxamer 184 significantly enhanced the skin penetration of irinotecan and alpha-mangostin to a greater extent than the solution. CLSM visualization revealed that folate-conjugated polymeric micelles penetrated through the skin by the transfollicular pathway as the major penetration pathway, whereas penetration by the intercluster pathway, transcellular pathway and intercellular pathway constituted a minor pathway. Conclusions: Folate-conjugated poloxamer 184 polymeric micelles are promising candidates for the dermal delivery of anticancer drugs by the transfollicular pathway as the major skin penetration pathway. Full article

Quantum sensing based on NV-centers in diamonds has been demonstrated many times in multiple publications. The majority of publications use lasers in free space or lasers with fiber optics, expensive optical components such as dichroic mirrors, or beam splitters with dichroic filters and expensive detectors, such as Avalanche photodiodes or single photon detectors, overall, leading to custom and expensive setups. In order to provide an inexpensive NV-based magnetometer setup for educational use in schools, to teach the three topics, fluorescence, optically detected magnetic resonance, and Zeeman splitting, inexpensive, miniaturized, off-the-shelf components with high reliability have to be used. The cheaper such a setup, the more setups a school can afford. Hence, in this work, we investigated LEDs as light sources, considered different diamonds for our setup, tested different color filters, proposed an inexpensive microwave resonator, and used a cheap photodiode with an appropriate transimpedance amplifier as the basis for our quantum magnetometer. As a result, we identified cheap and functional components and present a setup and show that it can demonstrate the three topics mentioned at a hardware cost <EUR 100. Full article

Optical materials are widely used in large optical systems such as lithography machines and astronomical telescopes. However, optical materials inevitably produce subsurface damage (SSD) during lapping and polishing processes, degrading the laser damage threshold and impacting the service life of the optical system. The large surface roughness of the lapped optical materials further increases the difficulty of the nondestructive detection of SSD. Quantum dots (QDs) show great development potential in the nondestructive detection of SSD in lapped materials. However, existing QD-based SSD detection methods ignore the polarization sensitivity of QDs to excitation light, which affects the detection accuracy of SSD. To address this problem, this paper explores the fluorescence polarization properties of QDs in the SSD of optical materials. First, the detection principle of SSD based on the fluorescence polarization of QDs is investigated. Subsequently, a fluorescence polarization detection system is developed to analyze the fluorescence polarization properties of QDs in SSD. Finally, the SSD is detected based on the studied polarization properties. The results show that the proposed method effectively improves the detection rate of SSD by 10.8% and thus provides guidance for evaluating the quality of optical material and optimizing optical material processing technologies. The research paradigm is equally applicable to biomedicine, energy, optoelectronics, and the environment, where QDs have a wide range of applications. Full article

Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical treatment and radiotherapy, phototherapy has the advantages, including short response time, significant efficacy, and minimal side effects in disease diagnosis and treatment. Recent studies have shown that local thermal energy or singlet oxygen generated by irradiating certain organic molecules or nanomaterials with specific laser wavelengths can effectively degrade Aβ aggregates and depress the generation of ROS, promoting progress in AD diagnosis and therapy. Herein, we outline the development of photothermal therapy (PTT) and photodynamic therapy (PDT) strategies for the diagnosis and therapy of AD by modulating Aβ aggregation. The materials mainly include organic photothermal agents or photosensitizers, polymer materials, metal nanoparticles, quantum dots, carbon-based nanomaterials, etc. In addition, compared to traditional fluorescent dyes, aggregation-induced emission (AIE) molecules have the advantages of good stability, low background signals, and strong resistance to photobleaching for bioimaging. Some AIE-based materials exhibit excellent photothermal and photodynamic effects, showing broad application prospects in the diagnosis and therapy of AD. We further summarize the advances in the detection of Aβ aggregates and phototherapy of AD using AIE-based materials. Full article

This study aimed to investigate the tyrosine kinase inhibitor Nintedanib and its potential role in reversing epithelial–mesenchymal transition (EMT) induced by transforming growth factor beta 2 (TGF-β2) in retinal pigment epithelial (RPE) cells, along with its therapeutic potential using a mouse model of subretinal fibrosis. We hypothesized that the blockade of angiogenesis promoting and fibrosis inducing signaling using the receptor tyrosine kinase inhibitor Nintedanib (OfevTM) can prevent or reverse EMT both in vitro and in our in vivo model of subretinal fibrosis. Primary human retinal pigment epithelial cells (phRPE) and adult retinal pigment epithelial cell line (ARPE-19) cells were treated with TGF-β210 ng/mL for two days followed by four days of Nintedanib (1 µM) incubation. Epithelial and mesenchymal phenotypes were assessed by morphological examination, quantitative real-time polymerase chain reaction(qPCR) (ZO-1, Acta2, FN, and Vim), and immunocytochemistry (ZO-1, vimentin, fibronectin, and αSMA). Metabolites were measured using luciferase-based assays. Extracellular acidification and oxygen consumption rates were measured using the Seahorse XF system. Metabolic-related genes (GLUT1, HK2, PFKFB3, CS, LDHA, LDHB) were evaluated by qPCR. A model of subretinal fibrosis using the two-stage laser-induced method in C57BL/6J mice assessed Nintedanib’s therapeutic potential. Fibro-vascular lesions were examined 10 days later via fluorescence angiography and immunohistochemistry. Both primary and ARPE-19 RPE stimulated with TGF-β2 upregulated expression of fibronectin, αSMA, and vimentin, and downregulation of ZO-1, consistent with morphological changes (i.e., elongation). Glucose consumption, lactate production, and glycolytic reserve were significantly increased in TGF-β2-treated cells, with upregulation of glycolysis-related genes (GLUT1, HK2, PFKFB3, CS). Nintedanib treatment reversed TGF-β2-induced EMT signatures, down-regulated glycolytic-related genes, and normalized glycolysis. Nintedanib intravitreal injection significantly reduced collagen-1+ fibrotic lesion size and Isolectin B4+ neovascularization and reduced vascular leakage in the two-stage laser-induced model of subretinal fibrosis. Nintedanib can induce Mesenchymal-to-Epithelial Transition (MET) in RPE cells and reduce subretinal fibrosis through metabolic reprogramming. Nintedanib can therefore potentially be repurposed to treat retinal fibrosis. Full article

Incorporation of lanthanide (Ln) and actinide (An) ions into the human body poses significant chemotoxic and radiotoxic risks, necessitating effective decorporation strategies. This study investigates the displacement of biologically relevant ligands from trivalent ions of europium, Eu(III), and curium, Cm(III), in artificial biofluids by various complexing agents, i.e., ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), diethylenetriaminepentaacetic acid (DTPA), and spermine-based hydroxypyridonate chelator 3,4,3-LI(1,2-HOPO) (HOPO). Utilizing a modified unified bioaccessibility method (UBM) to simulate gastrointestinal conditions, we conducted concentration-dependent displacement experiments at both room and body temperatures. Time-resolved laser-induced fluorescence spectroscopy (TRLFS) supported by ²H nuclear magnetic resonance (NMR) spectroscopy and thermodynamic modelling revealed the complexation efficacy of the agents under physiological conditions. Results demonstrate that high affinity, governed by complex stability constants and ligand pK_a values, is critical to overcome cation and anion competition and leads to effective decorporation. Additionally, there is evidence that cyclic ligands are inferior to linear ligands for this application. HOPO and DTPA exhibited superior displacement efficacy, particularly in the complete gastrointestinal tract simulation. This study highlights the utility of in vitro workflows for evaluating decorporation agents and emphasizes the need for ligands with optimal binding characteristics for enhanced chelation therapies. Full article

Swirl spray combustion has attracted significant attention due to its common usage in gas turbines. However, the high pressure in many practical applications remains a major obstacle to the deep understanding of flame stability and pollutant formation. To address this concern, this study investigated a swirl spray flame fueled with n-decane at elevated pressure. Planar laser-induced fluorescence (PLIF) of OH and polycyclic aromatic hydrocarbons (PAHs) were used simultaneously, enabling the distinction of the locations of OH, PAHs, and mixtures of them, providing detailed information on flame structure and evolution of PAHs. The effects of swirl number and ambient pressure on reaction zone characteristics and PAHs’ formation were studied, with the swirl number ranging from 0.30 to 1.18 and the pressure ranging from 1 to 3 bar. The data suggest that the swirl number changes the flame structure from V-shaped to crown-shaped, as observed at both atmospheric and elevated pressures. Additionally, varying swirl numbers lead to the initiation of flame divergence at distinct pressure levels. Moreover, PAHs of different molecular sizes exhibit significant overlap, with larger PAHs able to further extend downstream. The relative concentration of PAH increased with pressure, and the promoting effect of pressure on producing larger PAHs was significant. Full article

Thylakoid rhodanese-like protein (TROL) serves as a thylakoid membrane hinge linking photosynthetic electron transport chain (PETC) complexes to nicotinamide adenine dinucleotide phosphate (NADPH) synthesis. TROL is the docking site for the flavoenzyme ferredoxin-NADP⁺ oxidoreductase (FNR). Our prior work indicates that the TROL-FNR complex maintains redox equilibrium in chloroplasts and systemically in plant cells. Improvement in the knowledge of redox regulation mechanisms is critical for engineering stress-tolerant plants in times of elevated global drought intensity. To further test this hypothesis and confirm our previous results, we monitored light-independent ROS propagation in the leaves of Arabidopsis wild type (WT), TROL knock-out (KO), and TROL ΔRHO (RHO-domain deletion mutant) mutant plants in situ by using confocal laser scanning microscopy with specific fluorescent probes for the three different ROS: O₂^·−, H₂O₂, and ¹O₂. Plants were grown under the conditions of normal substrate moisture and under drought stress conditions. Under the drought stress conditions, the TROL KO line showed ≈32% less O₂^·− while the TROL ΔRHO line showed ≈49% less H₂O₂ in comparison with the WT. This research confirms the role of dynamical TROL-FNR complex formation in redox equilibrium maintenance by redirecting electrons in alternative sinks under stress and also points it out as promising target for stress-tolerant plant engineering. Full article

Low-level laser therapy (LLLT) is gaining attention as an effective adjunct to non-surgical periodontal treatment. This study evaluates the potential of LLLT to reduce bacterial load in a clinically relevant in vitro subgingival biofilm model and its impact on the inflammatory response. A subgingival biofilm model consisting of seven bacterial species was established. Primary human gingival fibroblasts (GFs) and periodontal ligament cells (PDLs) were cultured. Both biofilms and host cells were treated with the DenLase Diode Laser (980 nm) under various clinically relevant settings. The composition and structure of the seven-species biofilms were evaluated using quantitative PCR and fluorescence microscopy, respectively. The inflammatory response in host cells was analyzed by measuring the gene and protein expression levels of various inflammatory mediators. Laser treatment at power outputs ranging from 0.3 to 2 W had no significant effect on biofilm composition or architecture. LLLT, particularly at higher power settings, reduced the viability in both GFs and PDLs up to 70%. Gene expression levels of inflammatory mediators were only minimally influenced by laser treatment. However, LLLT significantly decreased the secretion of all examined cytokines. These findings suggest that LLLT with a 980 nm diode laser, under clinically relevant conditions, exerts anti-inflammatory rather than antimicrobial effects. Full article

In ecotoxicological risk assessment, current methods for measuring the transfer and bioavailability of organic pollutants like polycyclic aromatic hydrocarbons (PAHs) in bioindicators are often destructive and environmentally unfriendly. These limitations are especially problematic when only small amounts of biological material are available. Here, we present a novel, high-throughput method combining laser-induced UV fluorescence spectroscopy (UV-LIF) and solid-phase spectroscopy (SPS) for rapid, in situ quantification of PAHs in land snails—a key bioindicator species. Using dual excitation wavelengths (266 nm and 355 nm), our method reliably detected pyrene and fluoranthene in snails exposed to varying concentrations, demonstrating clear dose-responses and inter-individual differences in bioaccumulation. The analysis time per sample was under four minutes. This approach allows simultaneous measurement of internal contaminant levels and health biomarkers in individual organisms and aligns with green chemistry principles. These findings establish a new, scalable tool for routine assessment of PAH transfer and bioavailability in diverse ecosystems. Full article

Background/Objectives: The clinically validated multiplex Oncuria bladder cancer (BC) assay quickly and noninvasively identifies disease risk and tracks treatment success by simultaneously profiling 10 protein biomarkers in voided urine samples. Oncuria uses paramagnetic bead-based fluorescence multiplex technology (xMAP^®; Luminex, Austin, TX, USA) to simultaneously measure 10 protein analytes in urine [angiogenin, apolipoprotein E, carbonic anhydrase IX (CA9), interleukin-8, matrix metalloproteinase-9 and -10, alpha-1 anti-trypsin, plasminogen activator inhibitor-1, syndecan-1, and vascular endothelial growth factor]. Methods: In a pilot study (N = 36 subjects; 18 with BC), Oncuria performed essentially identically across three different common analyzers (the laser/flow-based FlexMap 3D and 200 systems, and the LED/image-based MagPix system; Luminex). The current study compared Oncuria performance across instrumentation platforms using a larger study population (N = 181 subjects; 51 with BC). Results: All three analyzers assessed all 10 analytes in identical samples with excellent concordance. The percent coefficient of variation (%CV) in protein concentrations across systems was ≤2.3% for 9/10 analytes, with only CA9 having %CVs > 2.3%. In pairwise correlation plot comparisons between instruments for all 10 biomarkers, R² values were 0.999 for 15/30 comparisons and R² ≥ 0.995 for 27/30 comparisons; CA9 showed the greatest variability (R² = 0.948–0.970). Standard curve slopes were statistically indistinguishable for all 10 biomarkers across analyzers. Conclusions: The Oncuria BC assay generates comprehensive urinary protein signatures useful for assisting BC diagnosis, predicting treatment response, and tracking disease progression and recurrence. The equivalent performance of the multiplex BC assay using three popular analyzers rationalizes test adoption by CLIA (Clinical Laboratory Improvement Amendments) clinical and research laboratories. Full article

In this study, we describe the preparation of carbon dots (CDs) from natural charcoal by laser ablation in a liquid. A continuum wave (CW) laser diode operating at a wavelength of 450 nm, hitting a solid carbon target placed into a biocompatible liquid, constituted of a phosphate-buffered saline (PBS) solution and distilled water, was used for the generation of the CDs suspension. Exploring the practical applications of carbon dots, it was observed that the luminescence of the produced CDs can be used as bioimaging in living organisms, environmental monitoring, chemical analysis, targeted drug delivery, disease diagnosis, therapy, and others. The CDs’ luminescence can be induced by UV irradiation and, as demonstrated in this study, by energetic MeV proton beams. The fluorescence was revealed mainly at 480 nm when UV illuminated the CDs, and also in the region at 514–642 nm when the CDs were irradiated by energetic proton ions. Atomic force microscopy (AFM) of the CD films revealed their spherical shape with a size of about 10 nm. The significance of the manuscript lies in the use of CDs produced by laser ablation exhibiting luminescence under irradiation of an energetic proton beam. Full article

Total internal reflection fluorescence–structured illumination microscopy (TIRF-SIM) can enhance the lateral resolution of fluorescence microscopy to twice the diffraction limit, enabling subtler observations of activity in subcellular life. However, the lack of an axial resolution makes it difficult to resolve three-dimensional (3D) subcellular structures. In this paper, we present an alternative TIRF-SIM axial resolution enhancement method by exploiting quantitative information regarding the distance between fluorophores and the surface within the evanescent field. Combining the lateral super-resolution information of TIRF-SIM with reconstructed axial information, a 3D super-resolution image with a 25 nm axial resolution is achieved without attaching special optical components or high-power lasers. The reconstruction results of cell samples demonstrate that the axial resolution enhancement method for TIRF-SIM can effectively resolve the axial depth of densely structured regions. Full article

During the manufacturing of precision optical elements, subsurface defects seriously affect the performance of the elements, leading to the enhancement of light fields, an increase in laser absorption and an decrease in mechanical properties. It has become a key technology to realize the high-precision quantitative automatic detection of subsurface defects of optical elements. This paper presents a method of subsurface defect detection based on spectral confocal scattering measurement, the system adopts a dispersive lens group with the working band of 480–670 nm, and combines the spectral confocal technology and total internal reflection technology to effectively suppress the interference of scattered light on the surface, and can realize high-precision nondestructive detection without fluorescent substances. The axial resolution of this method is 0.8 μm and the measuring depth range is 0.94 mm. By building a measurement system and carrying out experimental verification, the results show that this method can accurately measure the depth and location of subsurface defects and confirm its feasibility and effectiveness. Full article