Establishment of a mouse model of ovarian oxidative stress induced by hydrogen peroxide.

Introduction: Oxidative stress, resulting from environmental changes, significantly affects female fertility. Developing a mouse model to study oxidative stress lays the groundwork for research into human reproductive health and livestock fertility.

Materials And Methods: In this study, we established and evaluated an oxidative stress model by administering hydrogen peroxide (HO) to mice.

Molecularly imprinted polymer photoelectrochemical sensor for the detection of triazophos in water based on carbon quantum dot-modified titanium dioxide.

Widely used organophosphorus pesticide triazophos (TAP) can easily cumulate in aquatic system due to its high stability chemically and photochemically and thus posing significant threat to aquatic creatures and humans' health. Urging demand for rapid determining TAP in water has risen. Photoelectrochemical (PEC) sensing turns out to be a good candidate for its simplicity in fabrication and swiftness in detection.

An in-situ method for SERS substrate preparation and optimization based on galvanic replacement reaction.

Background: Various surface-enhanced Raman spectroscopy (SERS) substrate preparation methods have been reported, however, how to tune the "gap" between nanostructures to make more "hot spots" is still a barrier that restricts their application. The gap between nanostructures is usually fixed when the substrates are prepared. In other words, it is hard to tune interparticle distances for maximum electromagnetic coupling during substrate preparation process.

Recycled Graphite from Spent Lithium-Ion Batteries as a Conductive Framework Directly Applied in Red Phosphorus-Based Anodes.

The recycling of spent graphite from waste lithium-ion batteries (LIBs) holds great importance in terms of environmental protection and conservation of natural resources. In this study, a simple two-step method involving heat treatment and solution washing was employed to recycle spent graphite. Subsequently, the recycled graphite was milled with red phosphorus to create a carbon/red phosphorus composite that served as an anode material for the new LIBs, aiming to address the low capacity issue.

Au/TiO-based molecularly imprinted photoelectrochemical sensor for dibutyl phthalate detection.

A photoelectrochemical molecular imprinting sensor based on Au/TiO nanocomposite was constructed for the detection of dibutyl phthalate. Firstly, TiO nanorods were grown on fluorine-doped tin oxide substrate by hydrothermal method. Then, gold nanoparticles were electrodeposited on TiO to fabricate Au/TiO.

Nonmetallic Nitrogen-Doped MnO as Highly Efficient Oxygen Electrocatalyst for Rechargeable Zinc-Air Batteries.

Zinc-air batteries (ZABs) have been considered as one of the most promising energy storage devices to solve the problem of energy crisis and environmental pollution. In this work, we reported the synthesis of nitrogen-doped MnO (N-MnO ) to replace the noble metal electrocatalysts for air cathode in ZABs. The doped N atoms here introduced more Mn and oxygen vacancies for MnO , enhancing charge transfer property and accelerating surface intermediate product during the oxygen reduction reaction (ORR).

Photoelectrochemical aptasensor based on nanocomposite of CdSe@SnS for ultrasensitive and selective detection of sulfamethazine.

A photoelectrochemical (PEC) aptasensor based on CdSe@SnS nanocomposite has been developed to detect sulfamethazine (SMZ). The introduction of CdSe into SnS displayed an amplified PEC signal, which was higher than that of pure CdSe and SnS, attributable to its enhanced light harvesting capacity and promoted PEC energy conversion efficiency. Due to the formation of specific non-covalent bonds, the SMZ-binding aptamer (SBA) has significant specificity and sensitivity.

Fluorescence Detection of Cancer Stem Cell Markers Using a Sensitive Nano-Aptamer Sensor.

Antigen CD133 is a glycoprotein present on the surface of cancer stem cells (CSCs), which is a key molecule to regulate the fate of stem cells and a functional marker of stem cells. Herein, a novel fluorescence "turn-on" nano-aptamer sensor for quantifying CD133 was designed using hybridization between CD133-targeted aptamers and partially complementary paired RNA (ssRNA), which were modified on the surface of quantum dots (QDs) and gold nanoparticles (AuNPs), respectively. Owing to the hybridization of aptamers and ssRNA, the distance between QDs and AuNPs was shortened, which caused fluorescence resonance energy transfer (FRET) between them, and the florescence of QDs was quenched by AuNPs.

Functionalized N-Doped Carbon Nanotube Arrays: Novel Binder-Free Anodes for Sodium-Ion Batteries.

Boosting electrochemical sodium storage properties is achieved by utilizing functionalized N-doped carbon nanotube arrays (NCNAs) as anode materials. The NCNA anodes are first fabricated by self-polymerization of dopamine on cobalt hydroxide nanorod arrays as the template. The NCNAs with diameters of 100-120 nm are grown vertically to Ni foam, forming self-supported nanotube arrays.

Electrochemical Reduction of CO on Hollow Cubic CuO@Au Nanocomposites.

Surfactant-free and low Au loading CuO@Au and Au hollow cubes, based on electrodeposited CuO cubes as sacrificed templates, were prepared by means of a galvanic replacement reaction (GRR). The electrocatalytical performance of the as-prepared catalysts towards carbon dioxide (CO) electrochemical reduction was evaluated. The experimental results show that CuO@Au catalyst can convert CO to carbon monoxide (CO) with a maximum Faradaic efficiency (FE) of ~ 30.

Theoretical studies on the purine radical induced purine-purine type intrastrand cross-links.

At the density functional theory (DFT) level, addition reactions between the guanine-8-yl radical and its 3'/5' neighboring purine deoxynucleosides forming the purine-purine type intrastrand cross-links were studied. It is found that addition of the guanine-8-yl radical to the C8 site of its 5' neighboring deoxyguanosine or deoxyadenosine is a two-step reaction consisting of a structurally relatively unfavourable conformational transformation step, while the corresponding 3' C8 addition is straightforward and kinetically more efficient. The 3' C8 preference of the guanine-8-yl radical additions indicates the existence of an obvious sequence effect, which is completely opposite to that observed in the formation of pyrimidine radicals induced DNA intrastrand cross-links.

Voltammetric determination of levofloxacin using silver nanoparticles deposited on a thin nickel oxide porous film.

The authors describe a simplified chemical precipitation method and silver mirror reaction to synthesize a nanocomposite consiting of silver nanoparticles on a thin and porous nickel oxide film. Placed on a glassy carbon electrode (GCE), it allows for the determination of levofloxacin (LEV) via square wave voltammetry (SWV). Under optimal detection conditions, the voltammetric signal (typically measured at around 0.

Toxicity of six insecticides to predatory mite Amblyseius cucumeris (Oudemans) (Acari: Phytoseiidae) in- and off-field.

Amblyseius cucumeris (Oudemans) is a beneficial non-target arthropod (NTA) and a key predator of tetranychid mites in integrated pest management (IPM) programs across China. Evaluating the toxic effects of insecticides on such predatory mites is essential for the success and development of IPM. We tested six insecticides to determine the risk of neonicotinoid insecticide toxicity to predatory mites, using the 'open glass plate method' and adult female A.

Mechanism studies of addition reactions between the pyrimidine type radicals and their 3'/5' neighboring deoxyguanosines.

To clarify the biologically significant sequence effect existing in the formation of the pyrimidine-type radicals induced DNA intrastrand cross-links, addition mechanisms between the uridine-5-methyl (˙U ), 6-hydroxy-5,6-dihydrothymidine-5-yl (˙T), and 6-hydroxy-5,6-dihydrocytidine-5-yl (˙C) radicals and their 3'/5' neighboring deoxyguanosines (dG) are explored in the present study employing the model 5'-G(˙U )-3', 5'-(˙U )G-3', 5'-G(˙T)-3', 5'-(˙T)G-3', 5'-G(˙C)-3', and 5'-(˙C)G-3' sequences. It is found that the 5' G/C additions of the three radicals are all simple direct one-step reactions inducing only relatively small structural changes, while a conformational adjustment involving orientation transitions of both nucleobase moieties and twisting of the DNA backbone is indispensable for each 3' G/C addition. Furthermore, markedly positive reaction free energy requirements are estimated for these conformational transformations making the 3' G/C additions of the three radicals thermodynamically much more unfavorable than the corresponding 5' G/C additions.

Formation of pyrimidine-pyrimidine type DNA intrastrand cross-links: a theoretical verification.

Pyrimidine-type radicals have been demonstrated to be able to attack their 3' or 5' neighboring purine nucleotides forming diverse DNA intrastrand cross-links, but whether or not these radicals can attack their surrounding pyrimidine nucleotides forming pyrimidine-pyrimidine type DNA intrastrand cross-links remains unclear. To resolve this question, probable additions of the uracil-5-methyl (˙U) radical to the C[double bond, length as m-dash]C double bond of its 3'/5' neighboring pyrimidine nucleotides in the four models, 5'-T(˙U)-3', 5'-C(˙U)-3', 5'-(˙U)T-3', and 5'-(˙U)C-3', are explored in the present work employing density functional theory (DFT) methods. The C site of its 5' neighboring thymidine is the preferred target for ˙U radical addition, while additions of the ˙U radical to the C and C sites of its 5' neighboring deoxycytidine are found to be competitive reactions.

DNA intrastrand cross-links induced by the purine-type deoxyguanosine-8-yl radical: a DFT study.

Currently, all known DNA intrastrand cross-links are found to be induced by pyrimidine-type radicals; however, whether or not purine-type radicals are able to cause DNA intrastrand cross-links remains unclear. In the present study, probable additions of the highly reactive deoxyguanosine-8-yl radical to its 3'/5' neighboring pyrimidine nucleotides in four model compounds, 5'-G˙T-3', 5'-TG˙-3', 5'-G˙C-3', and 5'-CG˙-3', were studied using density functional theory (DFT) methods. In single-stranded DNA, the deoxyguanosine-8-yl radical is preferred to efficiently attack the C5 site of its 3' neighboring deoxythymidine or deoxycytidine, forming the G[8-5]T or G[8-5]C intrastrand cross-link rather than the C6 site forming the G[8-6]T or G[8-6]C intrastrand cross-link.

Mechanisms Responsible for High Energy Radiation Induced Damage to Single-Stranded DNA Modified by Radiosensitizing 5-Halogenated Deoxyuridines.

Experimental studies showed that high energy radiation induced base release and DNA backbone breaks mainly occur at the neighboring 5' nucleotide when a single-stranded DNA is modified by radiosensitizing 5-halogenated deoxyuridines. However, no mechanism can be used to interpret these experimental observations. To better understand the radiosensitivity of 5-halogenated deoxyuridines, mechanisms involving hydrogen abstraction by the uracil-5-yl radical from the C2' and C3' positions of an adjacent nucleotide separately followed by the C3'-O3' or N-glycosidic bond rupture and the P-O3' bond breakage are investigated in the DNA sequence 5'-TU(•)-3' employing density functional theory calculations in the present study.

The Equally Important Role of Adenine Derivatives to That of Pyrimidine Derivatives in Near-0 eV Electron-Induced DNA Lesions.

The role of adenine (A) derivatives in DNA damage is scarcely studied due to the low electron affinity of base A. Experimental studies demonstrate that low-energy electron (LEE) attachment to adenine derivatives complexed with amino acids induces barrier-free proton transfer producing the neutral N7 -hydrogenated adenine radicals rather than conventional anionic species. To explore possible DNA lesions at the A sites under physiological conditions, probable bond ruptures in two models-N7 -hydrogenated 2'-deoxyadenosine-3'-monophosphate (3'-dA(N7H)MPH) and 2'-deoxyadenosine-5'-monophosphate (5'-dA(N7H)MPH), without and with LEE attachment-are studied by DFT.

Excess electron reactivity in amino acid aqueous solution revealed by ab initio molecular dynamics simulation: anion-centered localization and anion-relayed electron transfer dissociation.

Studies on the structure, states, and reactivity of excess electrons (EEs) in biological media are of great significance. Although there is information about EE interaction with desolvated biological molecules, solution effects are hardly explored. In this work, we present an ab initio molecular dynamics simulation study on the interaction and reactivity of an EE with glycine in solution.

Computational insights into the charge relaying properties of β-turn peptides in protein charge transfers.

Density functional theory calculations suggest that β-turn peptide segments can act as a novel dual-relay elements to facilitate long-range charge hopping transport in proteins, with the N terminus relaying electron hopping transfer and the C terminus relaying hole hopping migration. The electron- or hole-binding ability of such a β-turn is subject to the conformations of oligopeptides and lengths of its linking strands. On the one hand, strand extension at the C-terminal end of a β-turn considerably enhances the electron-binding of the β-turn N terminus, due to its unique electropositivity in the macro-dipole, but does not enhance hole-forming of the β-turn C terminus because of competition from other sites within the β-strand.

Crucial role of solvent-impacted molecular anionic resonances in controlling protonation modes in the acetonitrile-water anionic cluster revealed by ab initio molecular dynamics simulations.

We present an ab initio molecular dynamics simulation study of a CH3CN-(H2O)40 cluster with an excess electron (EE) injected vertically in this work. Instead of surface bound or internally solvated electron, a hydrated CH3CN(-) is first formed as the CN transient after geometrical relaxation. The driving forces for the formation of CH3CN(-) are bending vibration of ∠CCN angle, which initiates transfer of an extra charge to the CH3CN LUMO, and hydration effect of the immediate water molecules, which plays a stabilizing role.