Origin of the Bright Photoluminescence of Thiolate-protected Gold Nanoclusters: Confined Structural Water Molecules as Real Emitters

The availability of a range of excited states has enriched zero-, one- and two- dimensional quantum nanomaterials with interesting luminescence properties, in particular for noble metal nanoclusters (NCs) as typical examples. But, the elucidation and origin of optoelectronic properties remains elusive. In this report, using widely used Au(I)-alkanethiolate complex (Au(I)-SRs, R = -(CH2)12H) with AIE characteristics as a model system, by judiciously manipulating the delicate surface ligand interactions at the nanoscale interface, together with a careful spectral investigations and an isotope diagnostic experiment of heavy water (D2O), we evidenced that the structural water molecules (SWs) confined in the nanoscale interface or space are real emitter centers for photoluminescence (PL) of metal NCs and the aggregate of Au(I)-SRs complexes, instead of well-organized metal core dominated by quantum confinement mechanics. Interestingly, the aggregation of Au(I)-SRs generated dual fluorescence-phosphorescence emission and the photoluminescence intensity was independent on the degree of aggregation but showed strong dependency on the content and state of structural water molecules (SWs) confined in the aggregates. SWs are different from traditional hydrogen bonded water molecules, wherein, due to interfacial adsorption or spatial confinement, the p orbitals of two O atoms in SWs can form a weak electron interaction through spatial overlapping, which concomitantly constructs a group of interfacial states with π bond characteristics, consequently providing some alternative channels (or pathways) to the radiation and/or non-radiation relaxation of electrons. Our results provide completely new insights to understand the fascinating properties (including photoluminescence, catalysis and chirality, etc.) of other low-dimension quantum dots and even for aggregation-induced emission luminophores (AIEgens). This also answers the century old debate on whether and how water molecules emit bright color.

New variety of the Lychnis coronaria (L.) Murray Ex Desr. Malinovy Rassvet selected by FSBSI FSVC

Relevance and methodology. Lychnis coronaria is a perennial herbaceous plant with high decorative properties, with prolonged flowering in the second or third year of vegetation. The pubescent leaves form beautiful rosettes. The plant is undemanding to the growing conditions. The research material was the varietal population of Lychnis coronaria. The study was carried out in the open ground of the Moscow region (2014- 2021) on experimental plots of the flower crops sector of the FSBSI FSVC.Results. The most aligned form according to decorative features was identified – LC 1-21 with high seed productivity of inflorescences, decorative and winter hardiness. A variety testing and preliminary reproduction of a promising cultivar of Lychnis coronaria was carried out. This variety was transferred to the FSBI "State Export Commission" in 2021 under the name “Malinovy Rassvet”. Such signs as "plant height", "bush diameter", "number of ornamental shoots", "flower diameter" had a low or average variation value, which characterizes this sample as the most aligned. Thus, the cv. “Malinovy Rassvet” of Lychnis coronaria is recommended for cultivation and use for decorative purposes. The leaves and the bright color of the flowers provide a contrast to the perennial borders and flower beds. It looks good both in single and group plantings, as well as in cutting. It is grown as a short-lived perennial. The main advantages of the variety are the color fastness of flowers when burned out in the sun, resistance to diseases and pests, high seed productivity.

Comparative analysis of high-speed videolaryngoscopy images and sound data simultaneously acquired from rigid and flexible laryngoscope: a pilot study

High-Speed Videoendoscopy (HSV) is becoming a robust tool for the assessment of vocal fold vibration in laboratory investigation and clinical practice. We describe the first successful application of flexible High Speed Videoendoscopy with innovative laser light source conducted in clinical settings. The acquired image and simultaneously recorded audio data are compared to the results obtained by means of a rigid endoscope. We demonstrated that the HSV recordings with fiber-optic laryngoscope have enabled obtaining consistently bright, color images suitable for parametrization of vocal fold oscillation similarly as in the case of the HSV data obtained from a rigid laryngoscope. The comparison of period and amplitude perturbation parameters calculated on the basis of image and audio data acquired from flexible and rigid HSV recording objectively confirm that flexible High-Speed Videoendoscopy is a more suitable method for examination of natural phonation. The HSV-based measures generated from this kymographic analysis are arguably a superior representation of the vocal fold vibrations than the acoustic analysis because their quantification is independent of the vocal tract influences. This experimental study has several implications for further research in the field of HSV application in clinical assessment of glottal pathologies nature and its effect on vocal folds vibrations.

Characteristic of morphological traits and biochemical indicators in Linum pubescens

The article describes the morphological characteristics and biochemical parameters of a very little studied wild species Linum pubescens (downy flax). This representative of the genus Linum naturally grows in the eastern Mediterranean: Palestine, Syria, Lebanon, Israel, Turkey, Iraq, Greece, Cyprus, Albania. There are brief references to it in the description of the flora of these regions. In Israel, on natural populations of L. pubescens, studies of dimorphic heterostyly, anatomical features of the flower, mechanisms of pollination and incompatibility were carried out. However, other signs, including economically valuable ones, are not described in him. We were the first to study the species ex-situ in a field bank. It was found that in the arid conditions of the southeastern Steppe of Ukraine L. pubescens has a one-year development cycle, a height of 30 cm, 1.2 flowering stems, a bright pink flower with a diameter of 25 mm, a small slightly elongated box with a diameter of 2.7 mm, weight 1000 seeds is 0.6 g, and the leaf area is 218.9 mm2. Plants bloom in mid-July- September. Taking into account the rather large size, the bright color of the flower and the flowering period, we believe that the L. pubescens species has prospects of use as an ornamental flowering plant. In the resulting artificial population of L. pubescens, dimorphic heterostyly is clearly traced. Long and short pest morphs are clearly identified. L. pubescens seeds contain 24% protein and 35% oil. The fatty acid composition of the oil belongs to the "linum-type", like most other types of flax. With a low content of saturated acids (palmitic 6.7% and stearic 2.8%) and a significant predominance of unsaturated acids, especially linolenic up to 64%. It was revealed that this species has a dense non-cracking capsule. This trait is unusual for other flax varieties. Most annual and perennial species are characterized by moderate to severe cracking. Cultivated flax has a non-cracking boll, but not a hard one that breaks easily. It was found that less organic matter and more ash elements accumulate in the capsules and seeds of L. pubescens than in other species of the genus Linum. Probably, this feature, together with non-cracking, helps to better preserve fruits in difficult natural conditions and preserves seed germination for a long time. According to A.A. Zhuchenko, plant genetic resources are divided into six groups. At this stage, L. pubescen is classified as a wild weed relative. It was proposed to include L. pubescens in breeding work to create ornamental varieties in order to transfer it to the improved germplasm group in the future.

Engineered RNA biosensors enable ultrasensitive SARS-CoV-2 detection in a simple color and luminescence assay

The continued resurgence of the COVID-19 pandemic with multiple variants underlines the need for diagnostics that are adaptable to the virus. We have developed toehold RNA–based sensors across the SARS-CoV-2 genome for direct and ultrasensitive detection of the virus and its prominent variants. Here, isothermal amplification of a fragment of SARS-CoV-2 RNA coupled with activation of our biosensors leads to a conformational switch in the sensor. This leads to translation of a reporter protein, for example, LacZ or nano-lantern that is easily detected using color/luminescence. By optimizing RNA amplification and biosensor design, we have generated a highly sensitive diagnostic assay that is capable of detecting as low as 100 copies of viral RNA with development of bright color. This is easily visualized by the human eye and quantifiable using spectrophotometry. Finally, this PHAsed NASBA-Translation Optical Method (PHANTOM) using our engineered RNA biosensors efficiently detects viral RNA in patient samples. This work presents a powerful and universally accessible strategy for detecting COVID-19 and variants. This strategy is adaptable to further viral evolution and brings RNA bioengineering center-stage.

Chemical syntheses and salient features of azulene-containing homo- and copolymers

Azulene is a non-alternant, aromatic hydrocarbon with many exciting characteristics such as having a dipole moment, bright color, stimuli responsiveness, anti-Kasha photophysics, and a small HOMO–LUMO gap when compared to its isomer, naphthalene. These properties make azulene-containing polymers an intriguing entity in the field of functional polymers, especially for organic electronic applications like organic field-effect transistors (OFET) and photovoltaic (PV) cells. Since azulene has a fused five and seven-membered ring structure, it can be incorporated onto the polymer backbone through either of these rings or by involving both the rings. These azulene-connection patterns can influence the properties of the resulting polymers and the chemical synthesis in comparison to the electrochemical synthesis can be advantageous in obtaining desired patterns of substitution. Hence, this review article presents a comprehensive overview of the developments that have taken place in the last three decades in the field of chemical syntheses of azulene-containing homo- and copolymers, including brief descriptions of their key properties.

Integrative Transcriptomics and Metabolomics Analysis of Body Color Formation in the Leopard Coral Grouper (Plectropomus leopardus)

Body color is an important economic and ecological trait in aquatic animals, which influence their economic values and determine the animal ability to survive in the marine environment. Red-colored Plectropomus leopardus is in high demand owing to its bright color and potential value for artificial breeding. High-throughput transcriptome sequencing and liquid chromatography tandem-mass spectrometry (LC-MS/MS) approaches were used to identify transcript and metabolic differences between black-colored and red-colored P. leopardus. Compared with the black-colored group, 218 and 181 differentially expressed genes were up- and down- regulated, respectively, in the red-colored group. 425 and 56 significantly different metabolites were identified in LC-MS positive and LC-MS negative ion models, respectively, between two colored groups. Based on the integrative analysis, the red-colored group exhibited greater carotenoid uptake, transport, and accumulation activity potential than those in the black-colored group and may consume more arachidonic acid for body color formation. The black-colored group showed greater melanin synthesis activity compared with the red-colored group. These results substantially improve the understanding of molecular and metabolic mechanisms underlying body color formation in P. leopardus and the potential of body color for the environment adaptation.

Effect of Shrimp Feed Supplemented with Astaxanthin on Golden Apple Snail Pomacea diffusa

Popularmente conhecidas como ampulárias, esses moluscos gastrópodes são usualmente cultivados como organismos ornamentais pelo mundo. A coloração desses animais ornamentais é um dos pontos que atrai os seus admiradores e estimula sua aquisição no mercado. O pigmento mais difundido como suplemento para intensificação de cor em organismos aquáticos é a astaxantina. Ainda não existem rações específicas para a ampulária reforçando a necessidade de testar alternativas de alimentos e suplementos que melhorem o desempenho produtivo e a atratividade do animal. Os objetivos desse estudo foram mensurar a capacidade de acumulação de astaxantina sintética em diferentes níveis de inclusão na dieta de Pomacea diffusa, sua influência na concentração do pigmento e nos índices zootécnicos ao final do cultivo. E em paralelo verificar a influência da mudança da dieta de ração de peixes para ração de camarão na condição corporal dos moluscos em comparação com o início do trabalho. As ampulárias alimentadas com ração comercial extrusada para camarão marinho tiveram baixos índices de conversão alimentar (126,7 ± 18,3), altos índices de eficiência alimentar (126,7 ± 18,3%) e fator de condição (1,0 ± 0,14) acima da média inicial (0,90 ± 0,17), o que demonstra que esse alimento pode ser utilizado para seu cultivo. A suplementação dietética de astaxantina sintética não resulta em aumento significativo da concentração desse pigmento na musculatura desse molusco (P˃0,05). Palavras-chave: Ampulária. Moluscos. Gastrópodes. Pigmentos. Carotenoides. Abstract Known as apple snail, these gastropods are popular as aquarium pets around the world. The bright color of these animals is one of the key points that attract their attention in the ornamental aquaculture, where deep-colored animals are well appreciated. Astaxanthin is the most widespread color enhancing pigment used as a food supplement for aquatic organisms. There is no specific commercial food for apple snails, emphasizing the need to search for food alternatives and supplements that improve their performance and attractiveness. The objectives of this study are to measure the synthetic astaxanthin accumulation capacity of Pomacea diffusa at different levels of diet supplementation, and the effect on pigment concentration and zootechnical indexes at the end of the culture. It was also aimed to verify the effect of the diet change from fish food to extruded shrimp food on the mollusks’ body condition. Apple snails fed with commercial shrimp ration had low feed conversion rates (0.81 ± 0.13), high food efficiency (126.7 ± 18.3%), and condition factor (1.0 ± 0.14) above the initial average (0.90 ± 0.17), demonstrating that this might be an advantageous alternative food. Dietary supplementation with synthetic astaxanthin did not result in a significant concentration increase of this pigment in muscle tissue of these mollusks (P˃0.05). Keywords: Aquaculture. Mollusks. Gastropods. Pigments. Carotenoids

Organoleptic Properties, Proximate Compositions, and Antioxidant Activity of Carrot – Navel Orange Marmalade

BACKGROUND: Oxidative stress due to free radicals leads to degenerative diseases such as cardiovascular disease. For prevention, high antioxidants food content is needed. AIM: The study aimed to identify the antioxidant activity, proximate compositions, and organoleptic properties of carrot – navel orange marmalade. METHODS: It was an experimental study with five formulations of marmalades, that is, F1 (100 g orange: 0 g carrot), F2 (100 g orange: 25 g carrot), F3 (100 g orange: 50 g carrot), F4 (100 g orange: 75 g carrot), and F5 (100 g orange: 100 g carrot). The organoleptic test assessment was executed through the visual analog scale instrument on hedonic and hedonic quality parameters. The measurement of proximate compositions was conducted according to the Association of Official Analytical Chemists. The carbohydrate was used by difference calculation, while the Brix measured by refractometer. The antioxidant activity was identified by the 1,1-Diphenyl-2-picrylhydrazyl method. RESULTS: The addition of juice and shredded carrot into navel orange marmalade tended to increase organoleptic values. Based on the sensory evaluation, the hedonic value of marmalade F1 had the lowest sensory acceptance value. The marmalade F2 (25% carrot) was dedicated as the most acceptable product with a medium bright color, quite pleasant aroma, a bit sweet, quite thick texture, and overall was quite attractive. Furthermore the carrot added significantly influenced the proximate (carbohydrate, protein, fat, fiber, water, and ash) (p < 0.05) and significantly increased the Brix (p < 0.05). The combination of carrot and orange resulted in a high antioxidant marmalade, with IC50 ranged 16.54 ± 0.02–19.83 ± 0.04 ppm. CONCLUSION: This study revealed that carrot – navel orange marmalade could be a suitable source of antioxidants.