Total Yield with an escape depth of approximately 100-200 A is known to be rather surface sensitive. Fluorescence Yield, on the other hand, with an escape depth of approximately 1000-2000 A is relatively less prone to surface effects but necessitates some corrections to obtain the true signal. Both have their plus and minus points and, if used with care, yield reliable data. In the present experiment both the techniques have been simultaneously employed for measuring orientation dependent O K and the Cu L3 edges from an uncleaved surface of I(2)BSCCO(2212) single crystal to compare the performance of the two modes of detection. Despite glaring differences in intensities the results from the two appear to show reasonable agreement in respect of relative intensities of the spectral features.
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http://dx.doi.org/10.1107/s0909049501000140 | DOI Listing |
Chemistry
January 2025
Institute of Organic Chemistry PAS: Instytut Chemii Organicznej Polskiej Akademii Nauk, Institute of Organic Chemistry, Kasprzaka 44/52, 01-224, Warsaw, POLAND.
Herein, we report the synthesis and chiroptical characteristics of the first (double) helicenes possesing the 1,4-dihydropyrrolo[3,2-b]pyrrole (DHPP) moiety as their central core. We have developed a three-step synthesis with 6π-electrocyclization accompanied with HBr elimination as its key step. We found that, whereas for smaller periphereal arms double 6π-electrocyclization occurs smoothly forming a double helicene, in the case of longer policyclic aromatic hydrocarbons the reaction becomes less efficient and mono-helicenes are the only products.
View Article and Find Full Text PDFBioconjug Chem
January 2025
Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1,Canada.
The ability to label synthetic oligonucleotides with fluorescent probes has greatly expanded their nanotechnological applications. To continue this expansion, it is essential to develop approachable, modular, and tunable fluorescent platforms. In this study, we present the synthesis and incorporation of an amino-formyl-thieno[3,2-]thiophene (AFTh) handle at the 5'-position of DNA oligonucleotides.
View Article and Find Full Text PDFAdv Healthc Mater
January 2025
Center for Molecular Systems and Organic Devices (CMSOD), Key Laboratory for Organic Electronics & Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications (NJUPT), Nanjing, 210023, China.
Organic photosensitizers (PSs) possessing NIR-II emission and photodynamic/photothermal effect have received a great sense of attention for their cutting-edge applications in imaging-guided multimodal phototherapy. However, it is highly challenging to design efficient PSs with high luminescence and phototherapy performance simultaneously. In this study, a spiro-functionalization strategy is proposed to alleviate aggregate-caused quenching of PSs and promote photodynamic therapy, and the strategy is verified via a spiro[fluorine-9,9'-xanthene]-modified NIR-II PS (named SFX-IC) with an acceptor-donor-acceptor configuration.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
College of Chemistry, Key Laboratory of High Performance Plastics, Ministry of Education, Jilin University, Changchun, 130012, China.
Aggregation-induced emission (AIE) materials have gained significant attention for their unique fluorescence enhancement in the aggregated state. However, combining rigid polymers with AIE molecules to enhance luminescent properties remains to be investigated. In this work, two novel AIE-active polyarylethersulfone (PAES) derivatives are synthesized by incorporating tetraphenylethene (TPE) into either the side chain or main chain of PAES, resulting in side-chain polyarylethersulfone-tetraphenylethene (PAES-TPE) and main-chain polyarylethersulfone-tetraphenylethene (m-PAES-TPE), respectively.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Emergency and Trauma of Ministry of Education, Department of Radiotherapy, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou 571199, China.
Ferroptosis is a type of cell death triggered by the iron-dependent accumulation of lipid peroxides in cells. Diabetes, a chronic metabolic disorder characterized by hyperglycemia, can lead to various health complications. The process of ferroptosis and the progression of diabetes are closely linked to redox homeostasis, which is regulated by the levels of reactive oxygen and sulfur species.
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