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Article
Open AccessRecovering true FRET efficiencies from smFRET investigations requires triplet state mitigation
Single-molecule fluorescence resonance energy transfer (smFRET) methods employed to quantify time-dependent compositional and conformational changes within biomolecules require elevated illumination intensitie...
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Article
Open AccessDiscovery of SARS-CoV-2 antiviral synergy between remdesivir and approved drugs in human lung cells
SARS coronavirus 2 (SARS-CoV-2) has caused an ongoing global pandemic with significant mortality and morbidity. At this time, the only FDA-approved therapeutic for COVID-19 is remdesivir, a broad-spectrum anti...
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Article
Open AccessCombination of antiviral drugs inhibits SARS-CoV-2 polymerase and exonuclease and demonstrates COVID-19 therapeutic potential in viral cell culture
SARS-CoV-2 has an exonuclease-based proofreader, which removes nucleotide inhibitors such as Remdesivir that are incorporated into the viral RNA during replication, reducing the efficacy of these drugs for tre...
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Article
Fluorescence sensing of microplastics on surfaces
Microplastics, nanoplastics and related products have been recently found in marine ecosystems worldwide, calling for new analytical methods for rapid detection and risk assessment. Fluorescence is a sensitive...
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Article
Open AccessSofosbuvir terminated RNA is more resistant to SARS-CoV-2 proofreader than RNA terminated by Remdesivir
SARS-CoV-2 is responsible for COVID-19, resulting in the largest pandemic in over a hundred years. After examining the molecular structures and activities of hepatitis C viral inhibitors and comparing hepatiti...
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Article
Open AccessDetection of the thietane precursor in the UVA formation of the DNA 6-4 photoadduct
Notwithstanding the central biological role of the (6-4) photoadduct in the induction of skin cancer by sunlight, crucial mechanistic details about its formation have evaded characterization despite efforts sp...
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Article
Open AccessIron imaging in myocardial infarction reperfusion injury
Restoration of coronary blood flow after a heart attack can cause reperfusion injury potentially leading to impaired cardiac function, adverse tissue remodeling and heart failure. Iron is an essential biometal...
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Article
The red chlorophyll catabolite (RCC) is an inefficient sensitizer of singlet oxygen – photochemical studies of the methyl ester of RCC
The red chlorophyll catabolite (RCC) is a proposed cryptic intermediate of chlorophyll (Chl) breakdown in higher plants. Its accumulation in higher plants is believed to be metabolically suppressed, as RCC is ...
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Article
Photochemical conversion of a cytidine derivative to a thymidine analog via [2+2]-cycloaddition
Epigenetic information is encoded in the mammalian genome in the form of cytosines methylated at the 5 position. Cytosine methylation has multiple biological effects, but our understanding of these effects has...
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Article
Intra-molecular triplet energy transfer is a general approach to improve organic fluorophore photostability
Bright, long-lasting and non-phototoxic organic fluorophores are essential to the continued advancement of biological imaging. Traditional approaches towards achieving photostability, such as the removal of mo...
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Article
Open AccessHighly Stable and Sensitive Fluorescent Probes (LysoProbes) for Lysosomal Labeling and Tracking
We report the design, synthesis and application of several new fluorescent probes (LysoProbes I-VI) that facilitate lysosomal pH monitoring and characterization of lysosome-dependent apoptosis. LysoProbes are ...
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Article
Photostabilization of endogenous porphyrins: excited state quenching by fused ring cyanoacrylates
Endogenous chromophores in human skin, when exposed to sunlight, generate harmful reactive oxygen species (ROS). Protoporphyrin IX (PpIX) is one of the common chromophores in human tissue. A series of aromatic...
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Article
Phototransformation of benzimidazole and thiabendazole inside cucurbit[8]uril
The phototransformation of benzimidazole (BZ) and of the benzimidazole pesticide thiabendazole (TBZ) was investigated in aqueous solution in the absence and presence of the supramolecular host cucurbit[8]uril ...
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Article
Photolysis of endoperoxides in the presence of nitroxides: a laser flash photolysis study with optical and ESR detection
Time-resolved electron paramagnetic resonance spectroscopy, transient absorption, and phosphorescence spectroscopy were used to investigate the spin polarization of a nitroxide free radical induced by interact...
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Article
Enantiospecific photochemical 6π-ring closure of α-substituted atropisomeric acrylanilides–role of alkali metal ions
Direct irradiation of atropisomeric α-substituted acrylanilides in the presence of alkali metal ions gave high ee values in the 3,4-dihydro-2-quinolin-2-one photoproduct, while in the absence of alkali metal i...
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Article
Photochemical studies of a fluorescent chlorophyll catabolite–source of bright blue fluorescence in plant tissue and efficient sensitizer of singlet oxygen
Fluorescent chlorophyll catabolites (FCCs) are fleeting intermediates of chlorophyll breakdown, which is seen as an enzyme controlled detoxification process of the chlorophylls in plants. However, some plants ...
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Article
CdSe/ZnS core shell quantum dot-based FRET binary oligonucleotide probes for detection of nucleic acids
We report the design, synthesis, and characterization of a binary oligonucleotide probe for selective DNA or RNA detection. The probe is based on fluorescence resonance energy transfer (FRET) from quantum dot ...
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Article
Photochemistry of 2-diphenylmethoxyacetophenone. Direct detection of a long-lived enol from a Norrish Type II photoreaction
Photolysis of 2-diphenylmethoxyacetophenone (1) in deaerated acetonitrile at room temperature is expected to proceed via Norrish Type II reaction to generate benzophenone (2) and acetophenone (4) as the main isol...
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Article
Adiabatic ring opening in tethered naphthalene and anthracene cycloadducts
The cycloadducts of tethered naphthalene and anthracene derivatives undergo photochemical ring opening to an electronically excited product with adiabatic yields up to 90%.
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Article
Physical and chemical quenching rates and their influence on stereoselective photooxygenation of oxazolidinone-functionalized enecarbamates
Physical and chemical quenching rate constants were measured for the reaction of singlet oxygen with oxazolidinonefunctionalized enecarbamates to investigate the role of vibrational deactivation in product ste...
