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Molekuliarnaia Biologiia 2024Photochemical reactions in cell DNA are induced in various organisms by solar UV radiation and may lead to a series of biological responses to DNA damage, including... (Review)
Review
Photochemical reactions in cell DNA are induced in various organisms by solar UV radiation and may lead to a series of biological responses to DNA damage, including apoptosis, mutagenesis, and carcinogenesis. The chemical nature and the amount of DNA lesions depend on the wavelength of UV radiation. UV type B (UVB, 290-320 nm) causes two main lesions, cyclobutane pyrimidine dimers (CPDs) and, with a lower yield, pyrimidine (6-4) pyrimidone photoproducts (6-4PPs). Their formation is a result of direct UVB photon absorption by DNA bases. UV type A (UVA, 320-400 nm) induces only cyclobutane dimers, which most likely arise via triplet-triplet energy transfer (TTET) from cell chromophores to DNA thymine bases. UVA is much more effective than UVB in inducing sensitized oxidative DNA lesions, such as single-strand breaks and oxidized bases. Of the latter, 8-oxo-dihydroguanine (8-oxodG) is the most frequent, being produced in several oxidation processes. Many recent studies reported novel, more detailed information about the molecular mechanisms of the photochemical reactions that underlie the formation of various DNA lesions. The information is mostly summarized and analyzed in the review. Special attention is paid to the oxidation reactions that are initiated by reactive oxygen species (ROS) and radicals generated by potential endogenous photosensitizers, such as pterins, riboflavin, protoporphyrin IX, NADH, and melanin. The review discusses the role that specific DNA photoproducts play in genotoxic processes induced in living systems by UV radiation of various wavelengths, including human skin carcinogenesis.
Topics: Ultraviolet Rays; Humans; DNA Damage; Pyrimidine Dimers; Reactive Oxygen Species; DNA; Animals; Apoptosis; Oxidation-Reduction; 8-Hydroxy-2'-Deoxyguanosine
PubMed: 38943577
DOI: No ID Found -
ACS Applied Materials & Interfaces Jun 2024Composites of organic small molecules (OSMs) and single-walled carbon nanotubes (SWCNTs) have drawn great attention as flexible thermoelectric (TE) materials in recent...
Composites of organic small molecules (OSMs) and single-walled carbon nanotubes (SWCNTs) have drawn great attention as flexible thermoelectric (TE) materials in recent years. Here, we synthesized thieno[2',3':4,5]thieno[3,2-]thieno[2,3-]thiophene (TTA) and 2,6-dibromothieno[2',3':4,5]thieno[3,2-]thieno[2,3-]thiophene (TTA-2Br) and compounded them with SWCNTs, obtaining thermoelectric TTA/SWCNT and TTA-2Br/SWCNT composites. The introduction of the electron-withdrawing Br group was found to decrease the highest molecular orbital energy level and bandgap () of TTA-2Br. As a result, the Seebeck coefficient () and power factor (PF) of the OSM/SWCNT composite films were significantly improved. Moreover, suitable energy barrier between TTA-2Br and SWCNTs facilitates the energy filtering effect, which further enhances thermoelectric properties of the 40 wt % TTA-2Br/SWCNT composite film with optimum thermoelectric properties (PF = 242.59 ± 9.42 μW m K at room temperature), good thermal stability, and mechanical flexibility. In addition, the thermoelectric generator (TEG) prepared using 40 wt % TTA-2Br/SWCNT composite films and n-type SWCNT films can generate an output power of 102.8 ± 7.4 nW at a temperature difference of 20 °C. This work provides new insights into the preparation of OSM/SWCNT composites with significantly enhanced thermoelectric properties.
PubMed: 38943571
DOI: 10.1021/acsami.4c07042 -
Bratislavske Lekarske Listy 2024To create a new mucoadhesive dosage form based on PluronicF127 followed by transformation into a gel form upon intranasal administration for targeted delivery to brain...
OBJECTIVES
To create a new mucoadhesive dosage form based on PluronicF127 followed by transformation into a gel form upon intranasal administration for targeted delivery to brain tissueMETHODS: Citicoline, cytidine diphosphocholine, designated as CDP-choline, was purchased as a white powder with the molecular weight of 510.31 g/mol. The triblock copolymers of polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol (PEG-PPG-PEG), branded as Pluronic F127, was used.
RESULTS
When instilled into the nasal cavity, Pluronic F127 for intranasal administration is transformed into a gel that remains retained for 45-55 minutes, which promotes better penetration of drugs into the brain tissue.
CONCLUSION
The polymer's gelling and adhesive properties performed well, which is crucial for further research at the preclinical stage (Tab. 1, Fig. 5, Ref. 28).
Topics: Administration, Intranasal; Poloxamer; Brain; Drug Delivery Systems; Animals; Cytidine Diphosphate Choline; Gels; Polyethylene Glycols; Nasal Mucosa
PubMed: 38943505
DOI: 10.4149/BLL_2024_67 -
Angewandte Chemie (International Ed. in... Jun 2024In thermally activated delayed fluorescence (TADF)-based organic light-emitting diodes (OLEDs), acceleration of reverse intersystem crossing (RISC) and suppression of...
In thermally activated delayed fluorescence (TADF)-based organic light-emitting diodes (OLEDs), acceleration of reverse intersystem crossing (RISC) and suppression of intersystem crossing (ISC) are demanded to shorten a lifetime of triplet excitons. As a system realizing RISC faster than ISC, inverted singlet-triplet excited states (iST) with a negative energy difference (ΔEST) between the lowest excited singlet and the lowest triplet states have been gathering much attention recently. Here, we have focused on an asymmetric hexa-azaphenalene (A6AP) core to obtain a new insight into iST. Based on A6AP, we have newly designed A6AP-Cz with the calculated ΔEST of -44 meV. The experimental studies of a synthesized A6AP-Cz revealed that the lifetime of delayed fluorescence (τDF) was only 54 ns, which was the shortest among all organic materials. The rate constant of RISC (kRISC = 1.9×107 s-1) was greater than that of ISC (kISC = 1.0×107 s-1). The negative ΔEST of A6AP-Cz was experimentally confirmed from 1) the kRISC and kISC (-45 meV) and 2) the temperature-dependent τDF. 3) The onsets of fluorescence and phosphorescence spectra at 77 K also supported the evidence of negative ΔEST (-73 meV). This study demonstrated the potential of A6AP as an iST core for the first time.
PubMed: 38943493
DOI: 10.1002/anie.202409670 -
Advanced Materials (Deerfield Beach,... Jun 2024Photoelectrochemical (PEC) devices offer a promising platform towards direct solar light harvesting and chemical storage. However, most prototypes employ wide bandgap...
Photoelectrochemical (PEC) devices offer a promising platform towards direct solar light harvesting and chemical storage. However, most prototypes employ wide bandgap semiconductors, moisture-sensitive inorganic light absorbers, or corrosive electrolytes. Here, we introduce the design and assembly of PEC devices based on an organic donor-acceptor bulk heterojunction (BHJ), which demonstrate long-term H evolution and CO reduction in benign aqueous media using a carbon-based encapsulant. Accordingly, PCE10:EH-IDTBR photocathodes display long-term H production for 300 h in a near-neutral pH solution, whereas photocathodes with a molecular CO reduction catalyst attain a CO:H selectivity of 5.41±0.53 under 0.1 sun irradiation. Their early onset potentials enable the construction of PCE10:EH-IDTBR - BiVO artificial leaves, which couple unassisted syngas production with O evolution in a reactor completely powered by sunlight, sustaining a 1:1 ratio of CO to H over 96 h of operation. This article is protected by copyright. All rights reserved.
PubMed: 38943473
DOI: 10.1002/adma.202404110 -
Advanced Materials (Deerfield Beach,... Jun 2024Films and patterns of 3D-oriented metal-organic frameworks (MOFs) afford well-ordered pore structures extending across centimeter-scale areas. These macroscopic domains...
Films and patterns of 3D-oriented metal-organic frameworks (MOFs) afford well-ordered pore structures extending across centimeter-scale areas. These macroscopic domains of aligned pores are pivotal to enhance diffusion along specific pathways and orient functional guests. The anisotropic properties emerging from this alignment are beneficial for applications in ion conductivity and photonics. However, the structure of 3D-oriented MOF films and patterns can rapidly degrade under humid and acidic conditions. Thus, more durable 3D-ordered porous systems are desired for practical applications. Here, oriented porous polymer films and patterns are prepared by using heteroepitaxially oriented N-functionalized MOF films as precursor materials. The film fabrication protocol utilizes an azide-alkyne cycloaddition on the Cu(AzBPDC)DABCO MOF. The micropatterning protocol exploits the X-ray sensitivity of azide groups in Cu(AzBPDC)DABCO, enabling selective degradation in the irradiated areas. The masked regions of the MOF film retain their N-functionality, allowing for subsequent cross-linking through azide-alkyne coupling. Subsequent acidic treatment removes the Cu ions from the MOF, yielding porous polymer micro-patterns. The polymer has high chemical stability and shows an anisotropic fluorescent response. The use of 3D-oriented MOF systems as precursors for the fabrication of oriented porous polymers will facilitate the progress of optical components for photonic applications. This article is protected by copyright. All rights reserved.
PubMed: 38943469
DOI: 10.1002/adma.202404384 -
Advanced Materials (Deerfield Beach,... Jun 2024Deep-sea equipment usually operates under dwell-fatigue condition, which means the equipped energy storage devices must survive under the changing pressure. Special...
Deep-sea equipment usually operates under dwell-fatigue condition, which means the equipped energy storage devices must survive under the changing pressure. Special mechanical designs should be considered to maintain the electrochemical performance of electrodes under this extreme condition. In this work, an effective assembly strategy is proposed to accommodate the dwell-fatigue loading using Ag decorated reduced graphene oxide (rGO) foam (denoted as AGF) as a superelastic and robust Zn host. The wet-press assembly process enables the formation of highly porous and robust framework. The strong synergetic effect between rGO and Ag further guarantees AGF's superelasticity and ultrahigh mechanical strength. Meanwhile, the homogeneously distributed Ag species on the rGO sheets act as zincophilic sites to effectively facilitate Zn plating. Furthermore, AGF offers enough space to address the expansion during the charge and discharge cycles. As expected, the symmetrical cell using this AGF@Zn host demonstrates a long lifespan over 400 h at a depth-of-discharge of 50%. It is worth mentioning that the superelastic AGF host realizes stable Zn plating/stripping under varying pressures.
PubMed: 38943439
DOI: 10.1002/adma.202405906 -
Small (Weinheim An Der Bergstrasse,... Jun 2024Conductive flexible hydrogels have attracted immense attentions recently due to their wide applications in wearable sensors. However, the poor mechanical properties of...
Conductive flexible hydrogels have attracted immense attentions recently due to their wide applications in wearable sensors. However, the poor mechanical properties of most conductive polymer limit their utilizations. Herein, a double network hydrogel is fabricated via a self-sorting process with cationic polyacrylamide as the first flexible network and the lantern[3]arene-based hydrogen organic framework nanofibers as the second rigid network. This hydrogel is endowed with good conductivity (0.25 S m) and mechanical properties, such as large Young's modulus (31.9 MPa), fracture elongation (487%) and toughness (6.97 MJ m). The stretchability of this hydrogel is greatly improved after the kirigami cutting, which makes it can be used as flexible strain sensor for monitoring human motions, such as bending of fingers, wrist and elbows. This study not only provides a valuable strategy for the construction of double network hydrogels by lanternarene, but also expands the application of the macrocycle hydrogels to flexible electronics.
PubMed: 38943438
DOI: 10.1002/smll.202404231 -
Archiv Der Pharmazie Jun 2024Anticonvulsant drug discovery has achieved significant progress; however, pharmacotherapy of epilepsy continues to be a challenge for modern medicine and pharmacy. To...
Anticonvulsant drug discovery has achieved significant progress; however, pharmacotherapy of epilepsy continues to be a challenge for modern medicine and pharmacy. To expand the chemical space of heterocycles as potential antiepileptic agents, herein we report on the synthesis and evaluation of anticonvulsant properties of a series of thiopyrano[2,3-d]thiazoles. The studied heterocycles are characterized by satisfactory drug-likeness and pharmacokinetics properties, calculated in silico using SwissADME. The anticonvulsant activity of thiopyrano[2,3-d]thiazole derivatives was evaluated in vivo using the subcutaneous pentylenetetrazole test. Three hits, that is, compounds 12, 14, and 16, that caused a pronounced anticonvulsant effect were identified. Derivatives 12, 14, and 16 positively affected the latent period of onset of clonic seizures, number of seizures, mortality rate, and duration of the seizure period of animals under experimental conditions. The anticonvulsant properties of compound 14 were equivalent to the effect of the reference drug, sodium valproate. All hit compounds are characterized by satisfying toxicity properties in the human lymphocytes and HEK293 cell line. The most active hit 14 possesses a potential affinity with the GABA receptor in the molecular docking study and forms a stable complex in the molecular dynamics experiments equal to diazepam. Preliminary SAR results were obtained and discussed based on screening data.
PubMed: 38943436
DOI: 10.1002/ardp.202400357 -
Environmental Microbiology Reports Aug 2024Till now, the diversity of entomopathogenic fungi in subtropical mountain forest was less studied. Here, the vertical distribution of forest soil fungi, entomopathogenic...
Till now, the diversity of entomopathogenic fungi in subtropical mountain forest was less studied. Here, the vertical distribution of forest soil fungi, entomopathogenic fungi, and their environmental influencing factors in a subtropical mountain in western China were investigated. Soil samples were collected from four elevations in a subtropical forest in Shaanxi. The results indicated a greater richness of soil fungi at middle elevations and soil fungi were more even at low elevation. Soil pH, available iron, available potassium, total potassium, and available zinc were the most important influencing factors affecting this vertical distribution of fungi. Interestingly, the Isaria genus was predominant while Metarhizium and Beauveria showed decreasing abundance. The presence of Isaria showed a significant positive correlation with both total phosphorus and available iron, while, available zinc was negatively correlated. Metarhizium was influenced by elevation, pH, available phosphorus, and available copper and Beauveria was influenced by soil organic carbon, total nitrogen, total potassium, available potassium, and available zinc. Overall, as environmental factors affecting soil fungi, elevation, and plant species diversity were less important than soil physical and chemical properties. The virulence of isolated entomopathogenic fungi were tested against larvae of Tenebrio molitor, with mortality ranging from 31.11% to 100%. The above findings provide valuable data to deepen our understanding of the diversity of entomopathogenic fungi in subtropical mountain forests.
Topics: China; Soil Microbiology; Forests; Animals; Fungi; Soil; Biodiversity; Tenebrio; Larva; Potassium; Hydrogen-Ion Concentration
PubMed: 38943366
DOI: 10.1111/1758-2229.13267