The as-prepared SWNTs are always a mixture of metallic (m-) and semiconducting (s-) tubes with quite different electrochemical properties which is a major barrier for their application in many fields. Based on the noncovalent interactions between planar aromatic molecules and SWNTs, the pyrene derivatives 1-docosyloxylmethylpyrene (DomP) was synthesized to separate the m-SWNTs and s-SWNTs via its significant selectivity toward s-SWNTs, i.e. electronic modulation. Before and after doping with electron, the electrochemical properties of s-SWNTs were studied and compared with that of m-SWNTs by electronic absorption spectroscopy, electrochemical impedance spectroscopy and cyclic voltammogram. As demonstrated, the electrocatalytic activity of electron modulated s-SWNTs was significantly improved and even better than m-SWNTs. Thus a novel sensor was constructed with the electron modulated s-SWNTs modified electrode and successfully applied for simultaneous determination of guanine and adenine.
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http://dx.doi.org/10.1016/j.aca.2019.06.027 | DOI Listing |
ACS Omega
January 2025
Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, United States.
DNA nucleobases are important in DNA sequencing, disease testing linked to genes, and disease treatment. Here, we report density functional calculations investigating the adsorption of guanine (G), adenine (A), thymine (T), and cytosine (C) on armchair graphene nanoribbons (AGNR) - a gapped semiconductor. Their adsorption energies, charge transfer, work function, and electrical properties were calculated.
View Article and Find Full Text PDFBMJ Case Rep
January 2025
Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
An African American man in his early 40s with progressive gait impairment and chronic cognitive impairment initially presented to the emergency department after statements of self-harm and was hospitalised. Examination revealed notable neurological abnormalities including impaired memory recall, oral dyskinesia/choreiform movements, dystonia of the right upper extremity with drift, hyper-reflexia and spastic gait. On further evaluation, including neurology and genetics consultation and workup, a clinical diagnosis of the neurodegenerative disorder Huntington's disease (HD) was made.
View Article and Find Full Text PDFNeurodegener Dis Manag
January 2025
Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA, USA.
Friedreich ataxia (FRDA) is a slowly progressive neurological disease resulting from decreased levels of the protein frataxin, a small mitochondrial protein that facilitates the synthesis of iron-sulfur clusters in the mitochondrion. It is caused by GAA (guanine-adenine-adenine) repeat expansions in the gene in 96% of patients, with 4% of patients carrying other mutations (missense, nonsense, deletion) in the gene. Compound heterozygote patients with one expanded GAA allele and a non-GAA repeat mutation can have subtle differences in phenotype from typical FRDA, including, in patients with selected missense mutations, both more severe features and less severe features in the same patient.
View Article and Find Full Text PDFCell Death Dis
January 2025
Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China.
Mitochondrial oxidative phosphorylation (OXPHOS) is a therapeutic vulnerability in glycolysis-deficient cancers. Here we show that inhibiting OXPHOS similarly suppresses the proliferation and tumorigenicity of glycolytically competent colorectal cancer (CRC) cells in vitro and in patient-derived CRC xenografts. While the increased glycolytic activity rapidly replenished the ATP pool, it did not restore the reduced production of aspartate upon OXPHOS inhibition.
View Article and Find Full Text PDFTagging RNAs with fluorogenic aptamers has enabled imaging of transcripts in living cells, thereby revealing novel aspects of RNA metabolism and dynamics. While a diverse set of fluorogenic aptamers has been developed, a new generation of aptamers are beginning to exploit the ring-opening of spirocyclic rhodamine dyes to achieve robust performance in live mammalian cells. These fluorophores have two chemical states: a colorless, cell-permeable spirocyclic state and a fluorescent zwitterionic state.
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