Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

Search Results (104)

Search Parameters:
Keywords = fluorometric analysis

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
21 pages, 3611 KB  
Article
Green-Synthesized Silver Nanoparticles from Zingiber officinale: Physicochemical Characterization, Antibacterial Activity, and TMPRSS2-Modulating Potential
by Ozlem Tavukcuoglu, Fatih Ciftci, Nilüfer Evcimen Duygulu, Duygu Misirli, Mahfuz Elmastaş and Ahmet Akif Kızılkurtlu
Nanomaterials 2026, 16(14), 836; https://doi.org/10.3390/nano16140836 - 8 Jul 2026
Viewed by 411
Abstract
In this study, green-synthesized silver nanoparticles derived from Zingiber officinale (G-AgNPs) were investigated as potential modulators of transmembrane serine protease 2 (TMPRSS2), a host-associated protease involved in viral entry mechanisms. Before nanoparticle synthesis, the phytochemical composition of ginger extract was analyzed using high-performance [...] Read more.
In this study, green-synthesized silver nanoparticles derived from Zingiber officinale (G-AgNPs) were investigated as potential modulators of transmembrane serine protease 2 (TMPRSS2), a host-associated protease involved in viral entry mechanisms. Before nanoparticle synthesis, the phytochemical composition of ginger extract was analyzed using high-performance liquid chromatography (HPLC) with photodiode array detection. Silver nanoparticles were synthesized using aqueous ginger extract as a reducing and stabilizing agent. The nanoparticles were characterized by ultraviolet–visible spectroscopy (UV–Vis.), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential analysis, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The synthesized silver nanoparticles exhibited a face-centered cubic (fcc) crystalline structure, nanoscale particle size distribution, and moderate colloidal stability. Transmission electron microscopy revealed predominantly quasi-spherical nanoparticles with an average diameter of 10.61 ± 1.31 nm, while X-ray diffraction indicated an average crystallite size of 15.28 ± 5.48 nm. Biological evaluation demonstrated robust, broad-spectrum antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, with distinct susceptibility profiles. Minimum Inhibitory Concentration (MIC) values were 3.125 µg/mL and 12.5 µg/mL, and Minimum Bactericidal Concentration (MBC) values were 6.25 µg/mL and 25.0 µg/mL, respectively. Cell culture assays confirmed high cytocompatibility with L929 fibroblasts at all tested concentrations. In a fluorometric enzyme assay, the silver nanoparticles inhibited TMPRSS2 activity in a concentration-dependent manner, achieving 51.24% inhibition at 100 µg/mL and an estimated IC50 of 40.06 µg/mL. Although the inhibitory activity was lower than that of Camostat, the findings suggest that ginger-mediated silver nanoparticles represent promising plant-based nano-bioactive systems for further investigation of TMPRSS2 modulation. Full article
(This article belongs to the Special Issue Antimicrobial Nanomaterials: Development and Applications)
Show Figures

Graphical abstract

22 pages, 9435 KB  
Article
Structure-Guided Discovery and Biochemical Validation of Novel Small-Molecule Inhibitors Predicted to Target the CCHFV OTU Protease Y89-W99 Pocket
by Sezer Akgöl and Fatih Kocabaş
Int. J. Mol. Sci. 2026, 27(13), 5661; https://doi.org/10.3390/ijms27135661 - 23 Jun 2026
Viewed by 340
Abstract
Crimean–Congo hemorrhagic fever virus (CCHFV) remains a major public health threat due to its high mortality rates and the absence of approved antiviral therapies. The viral ovarian tumor (OTU) protease is a critical virulence factor that suppresses host innate immunity through its deubiquitinase [...] Read more.
Crimean–Congo hemorrhagic fever virus (CCHFV) remains a major public health threat due to its high mortality rates and the absence of approved antiviral therapies. The viral ovarian tumor (OTU) protease is a critical virulence factor that suppresses host innate immunity through its deubiquitinase activity, making it an attractive therapeutic target. In this study, we employed a structure-guided approach to identify and validate novel small-molecule inhibitors targeting the non-catalytic Y89-W99 pocket of the OTU protease. Recombinant OTU protease was successfully expressed, purified, and refolded, yielding a soluble and enzymatically active protein. Cellular assays confirmed that the enzyme retains robust deubiquitinase activity, significantly reducing global ubiquitin conjugates in mammalian cells. In silico analysis of a putative DUB inhibitor library identified several candidate inhibitors with favorable binding interactions within the Y89-W99 pocket. Biochemical validation using a fluorometric Ub-AMC assay revealed that multiple small molecules strongly inhibit OTU activity, including OTUi-10 (~93% inhibition), OTUi-13 (~87%), OTUi-1 (~85%), OTUi-4 and OTUi-11 (~81%), and OTUi-9 (~76%). Additional moderate inhibitors included OTUi-12 (~67%), OTUi-19 and OTUi-21 (~66%), and OTUi-5 (~57%). In silico drug-likeness and toxicity profiling filtered the library to four fully compliant candidates, OTUi-4, OTUi-10, OTUi-11, and OTUi-12, all free of predicted toxicity alerts. These findings suggest that the Y89–W99 pocket may be a pharmacologically relevant site worthy of further investigation and identify OTUi-10, OTUi-4, and OTUi-11 as promising preliminary hit compounds. The results also provide initial insights that may guide future optimization and mechanistic studies of OTU protease inhibitors targeting CCHFV. Full article
(This article belongs to the Special Issue New Progress in Peptidic Protease Inhibitors)
Show Figures

Figure 1

15 pages, 1432 KB  
Article
Insulin Regulates AKT/GSK-3β Signalling, Tau Phosphorylation, and Redox Homeostasis in SH-SY5Y Neuroblastoma Cells
by Adrian Jorda, Kenia Alvarez-Gamez, Sara Vergani, Ilenia Paba, Mar Perez, Martin Aldasoro, Jose M. Vila and Soraya L. Valles
Int. J. Mol. Sci. 2026, 27(12), 5565; https://doi.org/10.3390/ijms27125565 - 19 Jun 2026
Viewed by 490
Abstract
Insulin (Ins) regulates multiple intracellular signalling pathways involved in cell survival, oxidative stress responses, and tau phosphorylation. Dysregulation of these pathways has been implicated in neurodegenerative disorders, including Alzheimer’s disease (AD). The present study evaluated the effects of insulin on protein kinase B/glycogen [...] Read more.
Insulin (Ins) regulates multiple intracellular signalling pathways involved in cell survival, oxidative stress responses, and tau phosphorylation. Dysregulation of these pathways has been implicated in neurodegenerative disorders, including Alzheimer’s disease (AD). The present study evaluated the effects of insulin on protein kinase B/glycogen synthase kinase-3 beta (AKT/GSK-3β) signalling, tau phosphorylation, and oxidative stress-related markers in SH-SY5Y neuroblastoma cells. Cell metabolic activity was assessed using the (diphenyltetrazolium bromide) MTT assay, while cell number and viability were evaluated by Trypan Blue exclusion, necrosis by lactate dehydrogenase (LDH) release, and apoptosis by Caspase-3 activity. Western blot analysis was performed to evaluate the expression of phosphorylated AKT (p-AKT), phosphorylated GSK-3β (p-GSK-3β Ser9), phosphorylated TAU (pTAU), nuclear factor erythroid 2-related factor 2 (NRF2), manganese superoxide dismutase (Mn-SOD), and copper/zinc superoxide dismutase (Cu/Zn-SOD). Lipid peroxidation was determined by measuring malondialdehyde (MDA) levels using a colorimetric/fluorometric assay. Insulin treatment increased MTT reduction (31.25%) and cell metabolic activity (119.15%) while reducing LDH release (19.2%) and Caspase-3 activity (31.26%). In addition, insulin significantly increased p-AKT (34.2%) and p-GSK-3β (Ser9) (19.9%) levels. A reduction in pTAU levels (53.39%) was also observed following insulin treatment. Furthermore, insulin increased NRF2 expression (18.77%), Cu/Zn-SOD (37.29%), and Mn-SOD (50.16%) and reduced MDA levels (13.95%). These findings indicate that insulin modulates signalling pathways associated with tau phosphorylation and cellular redox regulation in SH-SY5Y cells. Insulin treatment was associated with increased AKT and GSK-3β phosphorylation, reduced tau phosphorylation, and changes in oxidative stress-related markers in SH-SY5Y neuroblastoma cells. These findings support a role for insulin in the modulation of molecular pathways implicated in cellular stress responses and tau regulation. Further studies using differentiated neuronal models and disease-relevant conditions are required to determine the relevance of these observations to neurodegenerative disorders. Full article
(This article belongs to the Section Molecular Neurobiology)
Show Figures

Figure 1

17 pages, 10274 KB  
Article
ONX-0914 Alleviates Impaired Diabetic Wound Healing by Restoring Redox Homeostasis and Modulating Pro-Inflammatory Response
by Betül Çıkı, Damla Kayalı, Hafize Uzun, Necdet Altıner, Abdulhalim Şenyiğit and Betül Yılmaz
Medicina 2026, 62(6), 1122; https://doi.org/10.3390/medicina62061122 - 9 Jun 2026
Viewed by 349
Abstract
Background and Objectives: Diabetes mellitus (DM) is frequently associated with impaired wound healing due to persistent oxidative stress, chronic inflammation, and dysregulated proteasome activity, leading to delayed tissue repair and increased risk of chronic ulcers. The present study aimed to investigate the [...] Read more.
Background and Objectives: Diabetes mellitus (DM) is frequently associated with impaired wound healing due to persistent oxidative stress, chronic inflammation, and dysregulated proteasome activity, leading to delayed tissue repair and increased risk of chronic ulcers. The present study aimed to investigate the role of the immunoproteasome system in diabetic wound healing, with a particular focus on its involvement in oxidative stress and inflammatory pathways, and to evaluate whether pharmacological inhibition with ONX-0914 improves tissue repair. Materials and Methods: Experimental diabetes was induced in rats using streptozotocin (STZ), and the animals were allocated to three groups: healthy control, STZ-induced diabetic, and STZ + ONX-0914 treatment. Wound healing was evaluated by macroscopic analysis of wound closure and histopathological examination at days 3, 7, and 14. Oxidative stress and antioxidant status were assessed by measuring malondialdehyde (MDA) levels and antioxidant enzyme activities (SOD, CAT, and GSH-Px) in serum and wound tissues. Proteasome activity was analyzed fluorometrically, while systemic and local inflammatory responses were determined by ELISA and Western blot analysis of IL-1β, TNF-α, and IL-6. Results: STZ-induced diabetes significantly delayed wound closure, increased lipid peroxidation, reduced antioxidant enzyme activities, and elevated systemic and tissue inflammatory cytokine levels. Treatment with ONX-0914 markedly accelerated wound closure and improved histological healing parameters, including re-epithelialization, granulation tissue formation, and angiogenesis. Moreover, ONX-0914 significantly reduced MDA levels while restoring SOD, CAT, and GSH-Px activities in both serum and wound tissues. The treatment also inhibited proteasome activity and significantly suppressed the expression of IL-1β, TNF-α, and IL-6. Conclusions: ONX-0914 significantly improves diabetic wound healing by restoring antioxidant defenses, reducing oxidative damage, and attenuating inflammatory signaling pathways. These findings suggest that immunoproteasome inhibition represents a promising therapeutic strategy for enhancing tissue repair in diabetic conditions. Full article
(This article belongs to the Section Genetics and Molecular Medicine)
Show Figures

Figure 1

14 pages, 1088 KB  
Article
Localized Depletion of Seminal HDL-C Despite Preserved Systemic Lipid Profiles in Men with Impaired Semen Parameters: A Prospective Cross-Sectional Study
by Merve Huner Yigit, Ertugrul Yigit, Mehtap Atak and Hakki Uzun
Biomolecules 2026, 16(6), 820; https://doi.org/10.3390/biom16060820 - 1 Jun 2026
Viewed by 376
Abstract
Background: Lipid homeostasis is essential for sperm membrane integrity, capacitation, and fertilizing competence. However, whether lipid alterations associated with oligoasthenoteratozoospermia (OAT) reflect systemic dyslipidemia or a disturbance localized to the seminal compartment remains unclear. This study investigated serum high-density lipoprotein (HDL) subfractions and [...] Read more.
Background: Lipid homeostasis is essential for sperm membrane integrity, capacitation, and fertilizing competence. However, whether lipid alterations associated with oligoasthenoteratozoospermia (OAT) reflect systemic dyslipidemia or a disturbance localized to the seminal compartment remains unclear. This study investigated serum high-density lipoprotein (HDL) subfractions and seminal lipid concentrations in men with OAT. Methods: In this prospective cross-sectional study, 99 men were included: 49 men clinically classified as having OAT and 50 men with normozoospermia. Conventional semen analysis was performed according to the WHO 2021 manual. Serum HDL subfractions were analyzed using the Lipoprint HDL system, which classifies HDL into 10 subfractions and 3 major groups (large, intermediate, and small HDL). Seminal plasma total cholesterol and high-density lipoprotein cholesterol (HDL-C) were measured using enzymatic colorimetric and fluorometric assays, respectively. Correlations between lipid parameters and semen quality indices were assessed using Spearman’s rank analysis. Results: Baseline demographic and systemic metabolic characteristics were comparable between groups. Men with OAT had significantly higher FSH and estradiol levels and markedly impaired semen parameters, including sperm concentration, total sperm count, total motile sperm count, motility, and morphology. No significant differences were observed in serum HDL subfractions 1–10 or in large, intermediate, and small HDL concentrations between groups. In contrast, seminal total cholesterol was significantly lower in the OAT group (p = 0.048), and seminal HDL-C was markedly reduced (p < 0.001). Seminal HDL-C showed weak-to-moderate positive correlations with sperm concentration (ρ = 0.407), rapid progressive motility (ρ = 0.417), slow progressive motility (ρ = 0.418), total motile sperm count (ρ = 0.379), and normal morphology (ρ = 0.344) (all p < 0.001). Conclusions: OAT is characterized by a compartmentalized lipid alteration marked by preserved systemic HDL subfraction profiles but depleted seminal HDL-C. These findings suggest that local seminal lipid homeostasis may be more closely related to sperm quality than circulating HDL-related measures and support seminal HDL-C as a candidate local metabolic indicator in male infertility. Full article
(This article belongs to the Section Biological Factors)
Show Figures

Figure 1

15 pages, 1326 KB  
Article
Pre-Analytical and Analytical Challenges in Whole-Exome Sequencing of Formalin-Fixed Paraffin-Embedded Breast and Prostate Cancer Tissue: A Real-World Multicenter Study
by Mahira L. Rosa, Cláudia Bordignon, Jaqueline B. Schuch, Angélica C. Baumont, Marina Bessel, Giovana D. Curzel, Nathan A. Cadore, Ana Paula M. Varela, Giovana T. dos Santos, Tiago F. Andreis, Francine H. Oliveira, Vitor F. Vasconcellos, Lilian A. R. Barros, Cristiano P. Souza, Williams F. Barra, Daniela L. C. Louzeiro, Alessandra Notari, Juliana J. de Menezes, Pedro E. R. Liedke, Gláucio A. Bertollo, Aline B. L. Gongora, Henrique G. Ascenco, Eduardo Kowalski-Neto, Christina P. Oppermann, Gustavo Werutsky, Edilmar M. Santos, Flavio S. Brandão, Ruffo Freitas, Jr., Angélica Nogueira-Rodrigues, André L. C. Mancini, Daniela D. Rosa and Gabriel S. Macedoadd Show full author list remove Hide full author list
Diagnostics 2026, 16(11), 1595; https://doi.org/10.3390/diagnostics16111595 - 23 May 2026
Cited by 1 | Viewed by 637
Abstract
Background/Objectives: Formalin-fixed paraffin-embedded tissue is widely used in pathology and molecular diagnostics, yet its variable quality can critically influence the accuracy of sequencing-based analyses. This study investigated pre-analytical and analytical factors that can affect exome sequencing performance in a Brazilian multicenter cohort [...] Read more.
Background/Objectives: Formalin-fixed paraffin-embedded tissue is widely used in pathology and molecular diagnostics, yet its variable quality can critically influence the accuracy of sequencing-based analyses. This study investigated pre-analytical and analytical factors that can affect exome sequencing performance in a Brazilian multicenter cohort of patients with breast cancer and prostate adenocarcinoma. Methods: Tumor samples were reviewed for diagnostic confirmation, and those with a minimum cellularity of 20% underwent DNA extraction, fluorometric quantification, fragmentation analysis, and exome sequencing. Pre-analytical parameters, including tumor content, DNA yield, and fragmentation profile, were recorded and correlated with sequencing results. Results: Only 36.7% of all analyzed samples (163/444) generated valid whole-exome sequencing data, corresponding to 55.6% of those that proceeded to sequencing (163/293). Although 94.5% of specimens met the minimum ≥20% cellularity threshold and 66.0% advanced to sequencing, a substantial proportion failed to yield usable exome data. Successful sequencing was associated with shorter storage durations (p < 0.001) and superior analytical parameters (higher autosomal coverage, longer read lengths, lower duplication rates, and higher target coverage at ≥500× and ≥100×; p < 0.001). Detailed fixation-related variables (e.g., formalin type, fixation time, ischemia time) were not consistently available across centers, representing a major limitation for causal interpretation of pre-analytical effects. Conclusions: Our study identified a high failure rate in sequencing archival tissue, highlighting the need to prioritize more recently collected specimens and refine standardized sample handling protocols to maintain DNA integrity. These improvements are essential for optimizing sequencing workflow performance and feasibility in real-world settings. Full article
(This article belongs to the Special Issue Predictive Biomarkers in Oncology)
Show Figures

Figure 1

12 pages, 1872 KB  
Article
A Boronic Acid-Based Glutamine Analog Forms a Covalent Adduct with Kidney-Type Glutaminase and Suppresses Triple-Negative Breast Cancer Cell Proliferation
by Thiruselvam Viswanathan, Dinesh Devadoss, Achyuta Nagaraj, Barry P. Rosen, Hitendra S. Chand and Venkadesh Sarkarai Nadar
Biomedicines 2026, 14(5), 1100; https://doi.org/10.3390/biomedicines14051100 - 13 May 2026
Viewed by 553
Abstract
Background: Cancer cells exhibit metabolic reprogramming characterized by increased dependence on glutamine to sustain rapid proliferation and biosynthetic demands. Kidney-type glutaminase (KGA), which catalyzes the first and rate-limiting step of glutamine metabolism, represents a promising therapeutic target, particularly in triple-negative breast cancer [...] Read more.
Background: Cancer cells exhibit metabolic reprogramming characterized by increased dependence on glutamine to sustain rapid proliferation and biosynthetic demands. Kidney-type glutaminase (KGA), which catalyzes the first and rate-limiting step of glutamine metabolism, represents a promising therapeutic target, particularly in triple-negative breast cancer (TNBC), an aggressive sub-type lacking effective targeted therapies. This study evaluated 2-amino-4-boronobutyric acid (ABBA), a boronic acid-containing glutamine analog, as a potential KGA inhibitor with anticancer activity. Methods: KGA inhibition was assessed using a fluorometric enzymatic assay. Cytotoxic effects were examined in multiple TNBC cell lines. Covalent docking and molecular simulation analysis were performed to characterize interactions between ABBA and the KGA active site. Results: ABBA potently inhibited KGA activity, with an IC50 of approximately 1.0 μM, demonstrating greater efficacy than several non-proteinogenic amino acid analogs. ABBA induced dose-dependent cytotoxicity across multiple TNBC cell lines, with pronounced sensitivity observed in basal sub-type cells and cellular sensitivity correlated with KGA expression levels. Expression of γ-glutamyl transpeptidase 1 (GGT1) was negligible, and, excluding any off-target effects, the observed anticancer effects are primarily attributed to KGA inhibition. Docking analysis indicated that ABBA forms a reversible covalent adduct with the catalytic Ser286 residue of KGA in a boronate tetrahedral geometry resembling transition-state mimics, while molecular simulation demonstrated stabilization of the complex through hydrogen bonding and electrostatic interactions. Conclusions: ABBA is a potent boron-based glutaminase inhibitor with therapeutic potential for targeting glutamine metabolism in TNBC. Further structural optimization and in vivo evaluation are warranted to advance ABBA toward therapeutic development. Full article
Show Figures

Figure 1

26 pages, 6685 KB  
Article
Quercetin Enhances Topotecan Cytotoxicity in Retinoblastoma Cells Through ROS-Associated Stress and Apoptotic Signaling
by Aydın Maçin, Erkan Duman, İlhan Özdemir and Mehmet Cudi Tuncer
Biomolecules 2026, 16(4), 597; https://doi.org/10.3390/biom16040597 - 17 Apr 2026
Viewed by 636
Abstract
Quercetin, a naturally occurring flavonoid, exhibits antiproliferative and pro-apoptotic effects across various cancer models. Topotecan, a topoisomerase I inhibitor, is used in the treatment of retinoblastoma; however, its clinical utility is limited by dose-dependent toxicity. This study aimed to investigate whether quercetin is [...] Read more.
Quercetin, a naturally occurring flavonoid, exhibits antiproliferative and pro-apoptotic effects across various cancer models. Topotecan, a topoisomerase I inhibitor, is used in the treatment of retinoblastoma; however, its clinical utility is limited by dose-dependent toxicity. This study aimed to investigate whether quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma and to explore the underlying mechanisms under both two-dimensional (2D) and three-dimensional (3D) conditions. Cell viability was assessed using the MTT assay, and drug interactions were evaluated using the combination index (CI) based on the Chou–Talalay method. Apoptosis was analyzed by Annexin V-FITC/PI staining and flow cytometry. Reactive oxygen species (ROS) levels and mitochondrial membrane potential were evaluated using fluorometric methods, and N-acetyl-L-cysteine (NAC) was used for functional modulation of oxidative stress. Three-dimensional tumor spheroid models were used to assess treatment effects under conditions that partially recapitulate tumor architecture. Gene expression levels of apoptosis-related markers and PI3K/Akt/mTOR pathway components were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The combination of quercetin and topotecan was associated with synergistic cytotoxic effects in Y79 cells (CI < 1), accompanied by increased ROS levels, mitochondrial membrane depolarization, and elevated apoptotic cell death. NAC co-treatment partially attenuated ROS levels and restored cell viability. In 3D spheroid models, combination treatment induced structural disruption, reduced viability, and increased cell death, effects that were partially reversed by NAC. Gene expression analysis revealed upregulation of pro-apoptotic genes and downregulation of survival-related genes, along with increased PTEN expression. Quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma cells under both 2D and 3D conditions. These effects were associated with ROS-associated cellular stress, mitochondrial dysfunction, and modulation of apoptotic and survival-related pathways. The partial rescue by NAC supports a contributory, but not exclusive, role of oxidative stress. These findings should be interpreted within a preclinical context and suggest that quercetin may represent a potential adjunct strategy warranting further validation in translational and in vivo models. Full article
(This article belongs to the Special Issue Cancer Research: Molecular Insights and Therapeutic Strategies)
Show Figures

Graphical abstract

9 pages, 1911 KB  
Article
Elemental Analysis of Waste Circuit Boards Based on Monochromatic Micro X-Ray Fluorescence
by Xingyi Wang, Jingge Wang, Qiqi Liu, Yumeng Li and Xiaoyan Lin
Optics 2026, 7(2), 29; https://doi.org/10.3390/opt7020029 - 16 Apr 2026
Viewed by 735
Abstract
Waste electronic components are valuable secondary resources containing various metals. Analyzing their elemental distribution is crucial for developing recycling methods. Micro- X-ray fluorescence (μ-XRF) is commonly used for this purpose, but traditional polychromatic X-ray excitation creates high background scattering. This masks trace element [...] Read more.
Waste electronic components are valuable secondary resources containing various metals. Analyzing their elemental distribution is crucial for developing recycling methods. Micro- X-ray fluorescence (μ-XRF) is commonly used for this purpose, but traditional polychromatic X-ray excitation creates high background scattering. This masks trace element signals, impairing detection limits and accurate identification of minor valuable or hazardous elements. To address this, this study developed a monochromatic μ-XRF spectrometer using a low-power molybdenum-target X-ray tube. The system integrates polycapillary lenses for X-ray regulation and a flat crystal for monochromatization, producing a micron-sized monochromatic X-ray spot with high power density. This design eliminates scattered background from the primary continuous spectrum and enhances excitation efficiency by concentrating photon flux, enabling high-brightness monochromatic beams even at low tube power. The spectrometer was validated by analyzing a waste printed circuit board. High-resolution elemental mapping successfully revealed clear distribution patterns of major elements like copper, nickel, and iron, consistent with their physical structures. These images allowed intuitive differentiation of compositional differences across functional regions. This technique effectively overcomes the background interference caused by polychromatic excitation and is expected to further enhance the quality and reliability of elemental distribution imaging. It provides a powerful tool for formulating precise, scientific recycling strategies for waste electronics. Full article
(This article belongs to the Section Photonics and Optical Communications)
Show Figures

Figure 1

14 pages, 1211 KB  
Article
Predominance of Biliverdin over Bilirubin in Human Seminal Plasma
by Nina Hojnik, Paola Sist, Sabina Passamonti, Borut Kovačič and Federica Tramer
Biomolecules 2026, 16(4), 569; https://doi.org/10.3390/biom16040569 - 11 Apr 2026
Viewed by 823
Abstract
Biliverdin (BV) and bilirubin (BR) are established endogenous antioxidants and immune modulators in other organ systems; however, their roles in the male genital tract remain undefined. The aim of this study was to quantify both bile pigments in human seminal plasma using a [...] Read more.
Biliverdin (BV) and bilirubin (BR) are established endogenous antioxidants and immune modulators in other organ systems; however, their roles in the male genital tract remain undefined. The aim of this study was to quantify both bile pigments in human seminal plasma using a fluorescent protein biosensor and to examine their associations with basic semen parameters. We analyzed forty-two semen samples from men undergoing infertility evaluation. Biliverdin predominated over bilirubin in 88.1% of samples. Biliverdin concentration ranged from 51.8 to 611.2 nM, whereas bilirubin ranged from 19.7 to 240.7 nM. The mean total amounts per ejaculate were 1054 pmol for biliverdin and 280 pmol for bilirubin. The total amount of bilirubin in the ejaculate was positively correlated with total sperm count (Rs = 0.47; p = 0.028), whereas biliverdin showed no significant association (Rs = 0.21; p = 0.723). Oligozoospermic samples had significantly lower bilirubin concentrations (p < 0.001) and lower total bilirubin amounts (p < 0.005). Teratozoospermic samples exhibited significantly higher biliverdin concentrations (p < 0.05). This study provides the first simultaneous quantification of biliverdin and unconjugated bilirubin in human seminal plasma and identifies distinct associations with sperm quality. These findings suggest that bile pigments may reflect localized redox-related processes in the male genital tract and may influence male fertility potential. Full article
Show Figures

Graphical abstract

20 pages, 3517 KB  
Article
Size-Specific Phytoplankton Pigment Characteristics in Jaran and Hansan Bays Based on HPLC Analysis
by Ye Hwi Kim, Seung Min Lee, Jin Ho Kim, Yejin Kim, Sanghoon Park, Jaesoon Kim, Hayoung Choi, Hyo-Keun Jang, Myung Joon Kim, Dabin Lee, Yoon Ji Lee, Jae Hyung Lee and Sang Heon Lee
J. Mar. Sci. Eng. 2026, 14(2), 206; https://doi.org/10.3390/jmse14020206 - 20 Jan 2026
Viewed by 955
Abstract
This study investigated the spatial and seasonal dynamics of phytoplankton communities in Jaran Bay, inner Hansan Bay, and outer Hansan Bay, with particular emphasis on size structure and pigment-based indicators of productivity and physiological status. Water sampling was conducted during May, August, and [...] Read more.
This study investigated the spatial and seasonal dynamics of phytoplankton communities in Jaran Bay, inner Hansan Bay, and outer Hansan Bay, with particular emphasis on size structure and pigment-based indicators of productivity and physiological status. Water sampling was conducted during May, August, and October in 2020, 2022, and 2023 and phytoplankton communities were analyzed using size-fractionated chlorophyll a measurements and high-performance liquid chromatography (HPLC) pigment analysis. Chlorophyll a concentrations exhibited pronounced seasonality, with consistently elevated values in August across all bays. Diatoms were predominant throughout the study period; however, their relative contribution declined in outer Hansan Bay during summer, coinciding with increased contributions from cryptophytes and cyanobacteria. Size-fractionated analyses revealed that large-sized phytoplankton (>20 µm) predominantly consisted of diatoms, whereas small-sized phytoplankton (<20 µm) were composed of diatoms and cryptophytes. Comparisons between fluorometric and pigment-based approaches indicated that pigment-based diagnostics overestimated microphytoplankton contributions, attributable to the presence of small-sized diatoms. Pigment indices further revealed that large-sized phytoplankton were characterized by higher photosynthetic carotenoid concentrations and lower photoprotective carotenoid ratios, indicative of enhanced photosynthetic activity and productivity. Overall, these findings highlight the critical role of phytoplankton size structure in regulating productivity and physiological responses in aquaculture-dominated coastal bays. Full article
(This article belongs to the Special Issue Marine Microalgae: Taxonomy, Diversity and Biogeography)
Show Figures

Figure 1

15 pages, 1999 KB  
Article
Construction of an Internal Standard Ratiometric Al3+ Selective Fluorescent Probe Based on Rhodamine B-Modified Naphthalimide-Grafted Chitosan Polymer
by Mei Yang, Shaobai Wen, Jun Zhang, Xiangxiang Li and Chunwei Yu
Chemistry 2025, 7(6), 193; https://doi.org/10.3390/chemistry7060193 - 3 Dec 2025
Cited by 1 | Viewed by 932
Abstract
Most reported fluorescent Al3+ probes rely on fluorescence signal enhancement or quenching. Since the change in fluorescence intensity is the sole detection signal, various factors such as instrumental efficiency, environmental conditions, and probe concentration can interfere with the signal output. In contrast, [...] Read more.
Most reported fluorescent Al3+ probes rely on fluorescence signal enhancement or quenching. Since the change in fluorescence intensity is the sole detection signal, various factors such as instrumental efficiency, environmental conditions, and probe concentration can interfere with the signal output. In contrast, ratiometric probes, which utilize two emission bands for self-calibration, provide significant advantages by minimizing or eliminating these uncertainties. In this study, a naphthalimide-rhodamine based the transition between the cyclic and open-ring forms of rhodamine as an Al3+-selective ratiometric probe, in which chitosan was identified as an ideal bridge and biocompatibility. The design concept was that when the target metal ion was present, the fluorescence intensity of naphthalimide remained largely unchanged, serving as an internal standard. In contrast, rhodamine B was employed to label the target molecules, with its fluorescence intensity varying in accordance with the target concentration. A series of experiments were carried out to investigate the fluorometric properties of the grafted polymer P. The results demonstrated that P exhibited selective interaction with Al3+ among the various metals tested. Using the fluorescence intensity ratio (I603 nm/I538 nm) of P, a good linear relationship was achieved for Al3+ concentrations ranging from 1.0 to 35.0 μM with a detection limit of 0.33 μM was obtained. Meanwhile, we employed the standard addition method for the quantitative analysis and detection of Al3+ in commercially available bottled water and tap water, achieving an ideal recovery rate. Full article
(This article belongs to the Special Issue Fluorescent Chemosensors and Probes for Detection and Imaging)
Show Figures

Figure 1

22 pages, 3926 KB  
Article
Water Quality Dynamics in Cyanobacterial Control in Brazilian Cerrado Reservoir
by Aline Arvelos Salgado, Kamila Almeidas dos Santos, Guilherme da Cruz dos Reis, Raviel Eurico Basso and Klebber T. M. Formiga
Sustainability 2025, 17(21), 9537; https://doi.org/10.3390/su17219537 - 27 Oct 2025
Viewed by 710
Abstract
Understanding cyanobacterial dominance in tropical reservoirs is crucial for water management. This study examined the dynamics of water quality in the João Leite Reservoir, situated in the Brazilian Cerrado, utilising 30 months of monitoring data from five sites. Physical, chemical, and biological parameters, [...] Read more.
Understanding cyanobacterial dominance in tropical reservoirs is crucial for water management. This study examined the dynamics of water quality in the João Leite Reservoir, situated in the Brazilian Cerrado, utilising 30 months of monitoring data from five sites. Physical, chemical, and biological parameters, including fluorometric chlorophyll-a, using multivariate statistics (Cluster Analysis, Principal Component Analysis, PCA; Canonical Correlation Analysis, CCA), were analysed alongside the Trophic State Index (TSI). Results showed temporal variations exceeded spatial differences. Cyanobacteria were dominant despite generally low nutrient levels and an oligotrophic TSI classification. Principal Component Analysis revealed that temperature is strongly associated with cyanobacterial density. However, Canonical Correspondence Analysis and correlations revealed limited direct statistical influence of measured physicochemical parameters, including nutrients, on cyanobacterial abundance. Findings suggest that in this warm, tropical system, high temperatures combined with stable hydrodynamics, resulting from long hydraulic retention times (>180 days), likely facilitate cyanobacterial success, overriding direct nutrient limitation. Full article
Show Figures

Figure 1

23 pages, 3808 KB  
Article
The Antiproliferative Activity of Tatridin A Against Prostate Cancer Cells Is Lost in Acid Medium by Transformation to Desacetyl-β-Cyclopyrethrosin
by Cecilia Villegas, Rebeca Pérez, Camilo Céspedes-Méndez, Viviana Burgos, Ricardo Baggio, Sebastián Suárez, Bernd Schmidt and Cristian Paz
J. Xenobiot. 2025, 15(5), 161; https://doi.org/10.3390/jox15050161 - 9 Oct 2025
Viewed by 1721
Abstract
Background: Prostate cancer (PC) progression is strongly driven by dysregulated signaling pathways, with NF-κB playing a central role. Sesquiterpene lactones have been reported to modulate this pathway. This study evaluated and compared the cytotoxic effects of two structurally distinct sesquiterpene lactones: Tatridin A, [...] Read more.
Background: Prostate cancer (PC) progression is strongly driven by dysregulated signaling pathways, with NF-κB playing a central role. Sesquiterpene lactones have been reported to modulate this pathway. This study evaluated and compared the cytotoxic effects of two structurally distinct sesquiterpene lactones: Tatridin A, a germacranolide, and desacetyl-β-cyclopyrethrosin, a eudesmanolide derivative. Their mechanisms of action were also examined, focusing on oxidative stress induction and NF-κB modulation. Methods: Chemical structures were confirmed by NMR and X-ray crystallography. Cytotoxicity was assessed in DU-145 and 22Rv1 PC cells using real-time cell analysis. Reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were measured with fluorometric assays. NF-κB activity was determined in THP-1 reporter cells and by Western blot of IκBα phosphorylation. Results: Tatridin A markedly reduced viability, showing lower IC50 values (81.4 ± 2.7 µM in DU-145 and 50.7 ± 1.9 µM in 22Rv1 cells) than desacetyl-β-cyclopyrethrosin (166.9 ± 3.2 µM and 290.3 ± 8.3 µM, respectively). It also inhibited proliferation at markedly lower concentrations, with clonogenic IC50 values of 7.7 µM in DU-145 and 5.24 µM in 22Rv1cells. Both compounds increased ROS, but tatridin A induced earlier and stronger responses and ΔΨm loss. Furthermore, tatridin A more effectively inhibited NF-κB signaling than classical inhibitors. Conclusions: Tatridin A exerts cytotoxic effects through oxidative stress, mitochondrial impairment, and NF-κB inhibition, supporting the therapeutic potential of germacranolides for the treatment of advanced PC. Full article
Show Figures

Graphical abstract

30 pages, 9006 KB  
Article
The Role of CD68+ Cells in Bronchoalveolar Lavage Fluid for the Diagnosis of Respiratory Diseases
by Igor D. Zlotnikov, Natalia I. Kolganova, Shamil A. Gitinov, Dmitry Y. Ovsyannikov and Elena V. Kudryashova
Immuno 2025, 5(3), 43; https://doi.org/10.3390/immuno5030043 - 22 Sep 2025
Cited by 2 | Viewed by 2377
Abstract
Addressing the critical challenge in the differential diagnosis of severe inflammatory lung diseases, we propose a novel methodology for the analysis of macrophage surface receptors, CD68 and CD206, using specific non-antibody ligands. We developed a non-antibody alternative for the fluorometric detection of CD68+ [...] Read more.
Addressing the critical challenge in the differential diagnosis of severe inflammatory lung diseases, we propose a novel methodology for the analysis of macrophage surface receptors, CD68 and CD206, using specific non-antibody ligands. We developed a non-antibody alternative for the fluorometric detection of CD68+ cells, focusing on macrophages as key functional markers in inflammatory processes. Our marker based on dioleylphosphatidylserine (DOPS), a specific ligand to CD68, was incorporated into a liposomal delivery system. The specificity of this DOPS-based ligand can be precisely modulated by the liposome’s composition and the polyvalent presentation of the ligand. We synthesized a series of fluorescently-labeled DOPS-based ligands and developed a liposome-based sandwich fluorometric assay. This assay enables the isolation and quantification of CD68 receptor presence from bronchoalveolar lavage fluid (BALF). The results confirmed the specific binding of DOPS/lecithin liposomes to CD68+ cells compared to control lecithin systems. Furthermore, the incorporation of PEGylated ‘stealth’ liposomes significantly enhanced binding specificity and facilitated the generation of distinct binding profiles, which proved valuable in differentiating various inflammatory conditions. This approach yielded unique binding profiles of PS-based ligands to CD68+ cells, which varied significantly among a broad range of respiratory conditions, including primary ciliary dyskinesia, bronchial asthma, bronchitis, bacterial infection, pneumonia, and bronchiectasis. Confocal Laser Scanning Microscopy demonstrated selective binding and intracellular localization of the DOPS-based marker within CD68+ macrophages from BALF samples of patients with bronchitis or asthma. The binding parameters of this multivalent composite ligand with the CD68 receptor are comparable to those of antibodies. The inherent binding specificity of phosphatidylserine may offer a sufficient and viable alternative to conventional antibodies. Our results demonstrate the remarkable potential of this novel DOPS-based assay as a complementary tool for the developing non-antibody-based systems for the differential diagnosis of the respiratory diseases, warranting further investigation in larger clinical studies. Full article
Show Figures

Figure 1

Back to TopTop