The effect on the fluorescence of the europium:tetracycline (Eu:Tc), europium:oxytetracycline (Eu:OxyTc) and europium:chlortetracycline (Eu:ClTc) complexes in approximately 2:1 ratio of nitric oxide (NO), peroxynitrite (ONOO(-)), hydrogen peroxide (H2O2) and superoxide (O2 (·-)) was assessed at three ROS/RNS concentrations levels, 30 °C and pH 6.00, 7.00 and 8.00. Except for the NO, an enhancement of fluorescence intensity was observed at pH 7.00 for all the europium tetracyclines complexes-the high enhancement was observed for H2O2. The quenching of the fluorescence of the Tc complexes, without and with the presence of other ROS/RNS species, provoked by NO constituted the bases for an analytical strategy for NO detection. The quantification capability was evaluated in a NO donor and in a standard solution. Good quantification results were obtained with the Eu:Tc (3:1) and Eu:OxyTc (4:1) complexes in the presence of H2O2 200 μM with a detection limit of about 3 μM (Eu:OxyTc).
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Inorg Chem
January 2025
Department of Material and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden.
Zinc oxide (ZnO) is a semiconductor with a wide range of applications, and often the properties are modified by metal-ion doping. The distribution of dopant atoms within the ZnO crystal strongly affects the optical and magnetic properties, making it crucial to comprehend the structure down to the atomic level. Our study reveals the dopant structure and its contents in Eu-doped ZnO nanosponges with up to 20% Eu-O clusters.
View Article and Find Full Text PDFInt J Colorectal Dis
January 2025
Department of Surgery, Division of Coloproctology, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande Do Sul. Room 600 A, Rua Ramiro Barcelos, Porto Alegre, RS, 2350, Brazil.
Purpose: The presence of chaperones during intimate physical examinations is a matter of ongoing debate. While most guidelines recommend the use of chaperones in all cases, there are no clinical trials specifically investigating intimate exams performed on women by male physicians. We aimed to evaluate female patients' perceptions regarding the presence or absence of chaperones during proctological examinations conducted by male physicians.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
The diiridium complexes of lithium-ion endohedral fullerene Li@C were synthesised in high yields. X-ray crystallography revealed the η:η-coordination of Li@C and the disorder of the Li ion over two sites close to the coordinated carbons. C NMR study suggested the presence of dynamic behaviour haptotropic rearrangements.
View Article and Find Full Text PDFJ Org Chem
January 2025
Chemistry Department, Georgetown University, Washington, D.C. 20057, United States.
The reaction between a chiral carboxylic acid molecule and 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride in the presence of a mild base generates a chiroptically active metal complex displaying strong circular dichroism (CD) signals in the visible light region, a highly sought-after goal in the optical sensing realm. The molecular recognition process is complete within a few minutes and can be used for fast chiroptical determination of the enantiomeric composition and concentration of carboxylic acid samples. This method is operationally simple and broadly applicable to a large variety of structures including important drugs, natural products, amino acids, and hydroxy acids.
View Article and Find Full Text PDFAnal Chem
January 2025
School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China.
Conventional solid/liquid electrochemical interfaces typically encounter challenges with impeded mass transport for poor electrochemical quantification due to the intricate pathways of reactants from the bulk solution. To address this issue, this work reports an innovative approach integrating a target-activated DNA framework nanomachine with electrochemically driven metal-organic framework (MOF) conversion for self-sacrificial biosensing. The presence of the target biomarker serotonin initiates the DNA framework nanomachine by an entropy-driven circuit to form a cross-linked nanostructure and subsequently release the Fe-MOF probe.
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