Dynamics of hydrogen shift reactions between peroxy radicals.

Peroxy radicals are key intermediates in many atmospheric processes. Reactions between such radicals are of particular interest as they can lead to accretion products capable of participating in new particle formation (NPF). These reactions proceed through a tetroxide intermediate, which then decomposes to a complex of two alkoxy radicals and O, with spin conservation dictating that the complex must be formed in the triplet state.

Wavelength-dependent intersystem crossing dynamics of phenolic carbonyls in wildfire emissions.

Quantum chemical calculations were employed to construct Jablonski diagrams for a series of phenolic carbonyls, including vanillin, iso-vanillin, 4-hydroxybenzaldehyde, syringaldehyde, and coniferyl aldehyde. These molecules can enter the Earth's atmosphere from forest fire emissions and participate in photochemical reactions within the atmospheric condensed phase, including cloud and fog droplets and aqueous aerosol particles. This photochemistry alters the composition of light-absorbing organic content, or brown carbon, in droplets and particles through the formation and destruction of key chromophores.

Shedding new light on quadrupolar 1,4-dihydropyrrolo[3,2-]pyrroles: impact of electron-deficient scaffolds over emission.

In this work, we disclose a series of seven quadrupolar centrosymmetric 1,4-dihydropyrrolo[3,2-]pyrroles (DHPPs) linked to the two peripheral, strongly electron-accepting heterocycles such as benzoxadiazole, benzothiadiazole and benzoselenadiazole. This represents the first study probing the influence of electron-deficient heterocycles, rather that small electron-withdrawing substituents, on photophysics of DHPPs. These new acceptor-donor-acceptor hybrid dyes exhibit an appreciable combination of photophysical properties including absorption maxima in the range of 470-620 nm, and emission in the range of 500-720 nm with fluorescence quantum yields reaching 0.

Association of the Genotype of TNFα with the Efficiency of the Intensive Phase of Chemotherapy and Formation of the Sizes of Destruction Cavities in Patients with Pulmonary Tuberculosis.

The interrelation between the TNFα gene polymorphism and the effectiveness of the intensive phase of chemotherapy in patients with pulmonary tuberculosis, as well as the formation of diameter of the sizes of destruction cavities was studied. It was revealed that the most adverse course of the disease and a high frequency of formation of destruction cavities are associated with the GG genotype of the TNFα gene.

Nonradiative Deactivation of the Fluorescent Ag-DNA and Ag-DNA Emitters: The Role of Water.

The luminescent quantum yield of silver-cluster emitters stabilized by short oligonucleotides (Ag-DNA) may be efficiently tuned by replacing nucleobases in their stabilization DNA matrices with analogues. In the present study, we proposed a valuable and straightforward theoretical methodology for assessing the photophysical behaviors emerging in Ag-DNA emitters after excitation. Using green Ag-DNA and near-IR Ag-DNA emitters we demonstrate how point guanine/inosine replacement could affect the photophysical rate constants of radiative/nonradiative processes.

The effect of heavy atoms on the deactivation of electronic excited states of dye molecules near the surface of metal nanoparticles.

The influence of a heavy atom and the plasmon field on the efficiency of populating the lowest triplet state (T) and on the phosphorescence intensity has been studied for fluorescein, 2Br-fluorescein, eosin and erythrosine, which have an increasing number of substituted heavy atoms. We show that the heavy atoms affect not only the rate constant of intersystem crossing () but also the rate constant of internal conversion (). The calculations show that the C-H bonds in the position are the primary acceptors of the excitation energy of the lowest excited electronic singlet state (S).

Electrical Responsive Coating with a Multilayered TiO-SnO-RuO Heterostructure on Ti for Controlling Antibacterial Ability and Improving Osseointegration.

The bacterial infection and poor osseointegration of Ti implants could significantly compromise their applications in bone repair and replacement. Based on the carrier separation ability of the heterojunction and the redox reaction of pseudocapacitive metal oxides, we report an electrically responsive TiO-SnO-RuO coating with a multilayered heterostructure on a Ti implant. Owing to the band gap structure of the TiO-SnO-RuO coating, electron carriers are easily enriched at the coating surface, enabling a response to the endogenous electrical stimulation of the bone.

Low-Temperature Superplasticity of Ultrafine-Grained Aluminum Alloys: Recent Discoveries and Innovative Potential.

The last two decades have witnessed significant progress in the development of severe plastic deformation techniques to produce ultrafine-grained materials with new and superior properties. This review examines works and achievements related to the low-temperature superplasticity of ultrafine-grained aluminum alloys. The examples are provided of the possibility to observe low-temperature superplasticity in aluminum alloys at temperatures less than 0.

Neutral vs Charged Luminescent Radicals: Anti-Kasha Emission and the Impact of Molecular Surrounding.

Organic luminescent materials attract growing interest as an elegant solution for sustainable and inexpensive light-emitting devices. Most of them are neutral-emitting molecules with an implicit restriction of 25% internal quantum efficiency due to a spin-forbidden nature of the T → S transition. Utilizing organic radicals allows one to overcome such limits by theoretically boosting quantum yield up to 100%.

Molecular phosphorescence enhancement by the plasmon field of metal nanoparticles.

A theoretical model is proposed that allows the estimation of the quantum yield of phosphorescence of dye molecules in the vicinity of plasmonic nanoparticles. For this purpose, the rate constants of the radiative and nonradiative intramolecular transitions for rhodamine 123 (Rh123) and brominated rhodamine (Rh123-2Br) dyes have been calculated. The plasmon effect of Ag nanoparticles on various types of luminescence processes has been studied both theoretically and experimentally.

Microstructure Evolution during High-Pressure Torsion in a 7xxx AlZnMgZr Alloy.

A homogenized, supersaturated AlZnMgZr alloy was processed via severe plastic deformation (SPD) using a high-pressure torsion (HPT) technique for different revolutions at room temperature to obtain an ultrafine-grained (UFG) microstructure. The microstructure and mechanical properties of the UFG samples were then studied using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and tensile and hardness measurements. The main purpose was to study the effect of shear strain on the evolution of the microstructure of the investigated alloy.

Merging gold plasmonic nanoparticles and L-proline inside a MOF for plasmon-induced visible light chiral organocatalysis at low temperature.

Light-driven asymmetric photocatalysis represents a straightforward approach in modern organic chemistry. In comparison to the homogeneous one, heterogeneous asymmetric photocatalysis has the advantages of easy catalyst separation, recovery, and reuse, thus being cost- and time-effective. Here, we demonstrate how plasmon-active centers (gold nanoparticles - AuNPs) allow visible light triggering of chiral catalyst (proline) in model aldol reaction between acetone and benzaldehyde.

Experimental and computational studies of the optical properties of 2,5,8-tris(phenylthiolato)heptazine with an inverted singlet-triplet gap.

Photophysical properties of the three-fold symmetric 2,5,8-tris(phenylthiolato)heptazine molecule (1) are studied from combined experimental and computational viewpoints. The intense blue photoemission of 1 in the solid state and in toluene solution is proposed to have a fluorescent origin on the basis of a relatively short emission lifetime and no detectable triplet decay. Calculations at correlated levels of theory also show that 1 has a large inverted singlet-triplet (IST) gap, a non-vanishing spin-orbit coupling matrix element between the first excited singlet and triplet states, and a fast intersystem crossing rate constant that leads to singlet population from the higher-lying triplet state.

Eating disorder in children: Impact on quality of life, with a spotlight on autism spectrum disorder.

Eating behavior, which includes eating habits and preferences, frequency of eating, and other features related to diet, is a major characteristic not only of a person's nutritional status, but also of health in general. In recent years, the prevalence of eating disorders in children has tended to increase; they also require cross-system approaches in diagnosis by a variety of specialists and correction requires appropriate selection of optimal methods. Maladaptive eating attitudes formed at an early age can contribute to the formation of eating disorders, which can lead to or worsen various neuropsychiatric diseases, digestive diseases, and other related conditions.

Intramolecular rate-constant calculations based on the correlation function using temperature dependent quantum Green's functions.

A theoretical method for calculating rate constants for internal conversion (IC), intersystem crossing (ISC) and radiative (R) electronic transitions is presented. The employed method uses temperature-dependent quantum Green's functions, which give the opportunity to consider almost any nth-order polynomial perturbation operator and the influence of external electromagnetic fields on the rate constants. The rate constants of the IC, ISC and R processes are calculated for two important indocyanine molecules namely indocyanine green (ICG) and heptamethine cyanine (IR808) at the Franck-Condon level using the temperature-dependent quantum Green's function approach.

Internal conversion induced by external electric and magnetic fields.

We have developed a new methodology for calculating contributions to the rate constants () of internal conversion that are induced by external electric () or magnetic () fields. The influence of the external electric and magnetic fields on the was estimated for seven representative molecules. We show that the contribution calculated at a field strength of 10 V m is generally as large as the rate constant in the absence of the external field.

Engineering Tunable Ratiometric Dual Emission in Single Emitter-based Amorphous Systems.

Molecular emitters with multi-emissive properties are in high demand in numerous fields, while these properties basically depend on specific molecular conformation and packing. For amorphous systems, special molecular arrangement is unnecessary, but it remains challenging to achieve such luminescent behaviors. Herein, we present a general strategy that takes advantage of molecular rigidity and S -T energy gap balance for emitter design, which enables fluorescence-phosphorescence dual-emission properties in various solid forms, whether crystalline or amorphous.

Highly Efficient Room-Temperature Light-Induced Synthesis of Polymer Dots: A Programming Control Paradigm of Polymer Nanostructurization from Single-Component Precursor.

Polymer dots (PDs) have raised considerable research interest due to their advantages of designable nanostructures, high biocompatibility, versatile photoluminescent properties, and recyclability as nanophase. However, there remains a lack of , real-time, and noncontact methods for synthesizing PDs. Here we report a rational strategy to synthesize PDs through a well-designed single-component precursor (an asymmetrical donor-acceptor-donor' molecular structure) by photoirradiation at ambient temperature.

Effect of the Equal Channel Angular Pressing on the Microstructure and Phase Composition of a 7xxx Series Al-Zn-Mg-Zr Alloy.

A supersaturated Al-4.8%Zn-1.2%Mg-0.

In Vivo Studies of Medical Implants for Maxillofacial Surgery Produced from Nanostructured Titanium.

This paper presents the results of comprehensive in vivo studies into the osseointegration behavior of medical implants for maxillofacial surgery produced from nanostructured grade 4 titanium. Special attention is given to the phenomenology of bone tissue formation with consideration of its surface relief features and to evaluating the quantitative parameters of the morphological indicators of osteoblast and endothelial cells in the osseointegration zone. These parameters were compared with their measurement data for standard factory-made implants, and considerable acceleration in the fixation of nanotitanium implants due to osseointegation was found.

Nitrogen Photoelectrochemical Reduction on TiB Surface Plasmon Coupling Allows Us to Reach Enhanced Efficiency of Ammonia Production.

Ammonia is one of the most widely produced chemicals worldwide, which is consumed in the fertilizer industry and is also considered an interesting alternative in energy storage. However, common ammonia production is energy-demanding and leads to high CO emissions. Thus, the development of alternative ammonia production methods based on available raw materials (air, for example) and renewable energy sources is highly demanding.

Influence of plasmons on the luminescence properties of solvatochromic merocyanine dyes with different solvatochromism.

The effect of localized surface plasmon resonance (LSPR) of a system consisting of a highly dipolar merocyanine dye and a silver nanoparticle (NP) was studied experimentally and theoretically. A theoretical model for estimating the fluorescence quantum yield () using quantum chemical calculations of intramolecular and intermolecular electronic transition rate constants was developed. Calculations show that the main deactivation channels of the lowest excited singlet state of the studied merocyanines are internal conversion ((S → S)) and fluorescence ((S → S)).

Incorporation of a Fluorine Atom in a Bridging Ligand of Half-Lantern Pt Complexes Provides up to 10-Fold Enhancement of Electroluminescence Brightness.

The binuclear half-lantern platinum(II) complexes [Pt(pbt)(μ-SN)] (pbtH = 2-phenylbenzothiazole, SN = benzo[]thiazole-2-thiolate , 6-fluorobenzo[]thiazole-2-thiolate , 6-chlorobenzo[]thiazole-2-thiolate , 6-bromobenzo[]thiazole-2-thiolate , and 6-iodobenzo[]thiazole-2-thiolate ) were synthesized by the treatment of the in situ formed [Pt(pbt)(NCMe)]NO complex and appropriate benzo[]thiazole-2-thiole in the presence of BuOK; yield: 51-84%. Complexes - exhibit intense red photoluminescence originated from MMLCT state reaching 22% room temperature quantum yields in a CHCl solution. All complexes display excited-state decay kinetics both in solution and in the solid state; the kinetics was adequately modeled by single exponentials.

Gold(i)-containing light-emitting molecules with an inverted singlet-triplet gap.

Delayed fluorescence from molecules with an inverted singlet-triplet gap (DFIST) is the consequence of the unusual reverse order of the lowest excited singlet (S) and triplet (T) states of thermally activated delayed fluorescence (TADF) emitters. Heptazine (1,3,4,6,7,9,9-heptaazaphenalene) derivatives have an inverted singlet-triplet gap thanks to the combination of multiple resonance (MR) effects and a significant double excitation character. Here, we study computationally the effect of gold(i) metalation and coordination on the optical properties of heptazine (molecule 4) and the phosphine-functionalized 2,5,8-tris(dimethylphosphino)heptazine derivatives (molecules 1-3).

Targeted next-generation sequencing of 21 candidate genes in hereditary ovarian cancer patients from the Republic of Bashkortostan.

About 5-10% of all ovarian cancer cases show familial clustering, and some 15-25% of familial ovarian cancer cases are mediated by high-penetrance mutations in the BRCA1 and BRCA2 genes. Only few other genes have been identified for familial ovarian cancer.We conducted targeted next-generation sequencing of the protein coding region of 21 candidate genes, including UTR regions, in genomic DNA samples of 48 patients with familial ovarian cancer from the Republic of Bashkortostan.