Responses of Persian walnut on foliar applications of different biostimulants.

Biostimulants have different effects on plants. The aim of this paper is to determine responses of the 'Alsószentiváni 117' walnut cultivar on foliar applications of different biostimulants (Wuxal Ascofol, Kondisol, Alga K Plus). The nut traits (nut length, nut diameter, nut weight, kernel weight) and some phenolic compounds of the kernel were measured and detected. In 2020, during warmer early spring weather conditions under pistillate flowering receptivity, chlorogenic acid and quercetin content of kernels treated with Kondisol were higher than in control. All biostimulants influenced positive effects on catechin and rutin content, as well as treatments made with Wuxal Ascofol and Kondisol increased the juglon content of the kernel. In 2021, when the spring weather was typical for that period, only the Kondisol treatments had increasing effects on the catechin and chlorogenic acid content, than the control. The rutin and quercetin concentrations reached the highest value in this trial by Alga K Plus applications. The juglon content decreased in this year compared to the control. The pirocathecin, cinnamic acid, and gallic acid (except Wuxal Ascofol treatment in 2021) content decreased in all treatments in both observed years. Responses of woody fruit species on biostimulants applications depend on the weather conditions. Biostimulants had positive effects on the nut size characteristics in both observed years.

Assessment of Berries of Some Sea Buckthorn Genotypes by Physicochemical Properties and Fatty Acid Content of the Seed.

Sea buckthorn (Hippophae rhamnoides L.) is consumed mainly in its processed form. Therefore, the investigation of the physicochemical properties of its berries is a current task in the aspect of food processing. The aim of this study was to determine the physicochemical parameters (soluble solid content, total titratable acidity, sugar/acid ratio), color characteristics (L*, a*, b*) and fatty acid profile of five varieties ('Askola', 'Clara', 'Habego', 'Leikora', 'Mara') and one Hungarian candidate, R-01, to establish a basis for experiments on the processability of the whole berries (e.g., drying). The weight of the berry of 'Leikora' (0.64 g) was significantly higher than the other investigated fruits. The differences between the values of soluble solid content (6.3-10.84 °Brix) and titratable acid (1.4-3.7%) content of berries were significant. 'Mara' had the highest sugar/acid ratio. Regarding the fatty acid profile, the amount of unsaturated fatty acids was measured between 72.6-83.4%, including polyunsaturated fatty acids, which were between 32.3-58.1%. The seeds of the tested samples contained high concentrations of linoleic acid (17.0-33.2%) and linolenic acid (15.3-24.9%), mainly in the case of the 'Mara', 'Clara' and 'Askola' varieties. Candidate R-01 could be used as a raw material for functional foods due to its significant content of palmitoleic acid and a favourable omega-6/omega-3 ratio.

Effects of the repression of GIGANTEA gene StGI.04 on the potato leaf transcriptome and the anthocyanin content of tuber skin.

BACKGROUND: GIGANTEA (GI) is a plant-specific, circadian clock-regulated, nuclear protein with pleiotropic functions found in many plant species. This protein is involved in flowering, circadian clock control, chloroplast biogenesis, carbohydrate metabolism, stress responses, and volatile compound synthesis. In potato (Solanum tuberosum L.), its only role appears to be tuber initiation; however, based on findings in other plant species, we hypothesised that the function of GI in potatoes is not restricted only to tuberisation. RESULTS: To test this hypothesis, the expression of a GI gene in the commercial potato cultivar 'Désirée' was repressed, and the effects of repression at morphological and transcriptome level were investigated. Previously, two copies of GI genes in potato were found. A construct to reduce the mRNA levels of one of these genes (StGI.04) was assembled, and the effects of antisense repression were studied in greenhouse-grown plants. The highest level of repression reached around 50%. However, this level did not influence tuber formation and yield but did cause a reduction in tuber colour. Using high-performance liquid chromatography (HPLC), significant reductions in cyanidin 3,5-di-O-glucoside and pelargonidin 3,5-di-O-glucoside contents of tuber peels were detected. Anthocyanins are synthesized through a branch of the phenylpropanoid pathway. The transcriptome analysis indicated down-regulation in the expression of PHENYLALANINE AMMONIA LYASE (PAL), the LEUCOANTHOCYANIDIN OXIDISING enzyme gene LDOX, and the MYB-RELATED PROTEIN Hv1 (MYB-Hv1), a transcription factor coding gene, which is presumably involved in the regulation of flavonoid biosynthesis, in the leaves of a selected StGI.04-repressed line. Furthermore, alterations in expression of genes affecting the circadian clock, flowering, starch synthesis, and stress responses were detected in the leaves of the selected StGI.04-repressed line. CONCLUSIONS: We tested the effects of antisense repression of StGI.04 expression in potatoes and found that as with GI in other plant species, it influences the expression of the key genes of the circadian clock, flowering, starch synthesis, and stress responses. Furthermore, we detected a novel function of a GI gene in influencing the anthocyanin synthesis and potato tuber skin colour.

Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair.

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 µm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 µm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 µl/min, enabling to process finger prick blood samples within minutes.

Numerical Determination of the Secondary Acoustic Radiation Force on a Small Sphere in a Plane Standing Wave Field.

Two numerical methods based on the Finite Element Method are presented for calculating the secondary acoustic radiation force between interacting spherical particles. The first model only considers the acoustic waves scattering off a single particle, while the second model includes re-scattering effects between the two interacting spheres. The 2D axisymmetric simplified model combines the Gor'kov potential approach with acoustic simulations to find the interacting forces between two small compressible spheres in an inviscid fluid. The second model is based on 3D simulations of the acoustic field and uses the tensor integral method for direct calculation of the force. The results obtained by both models are compared with analytical equations, showing good agreement between them. The 2D and 3D models take, respectively, seconds and tens of seconds to achieve a convergence error of less than 1%. In comparison with previous models, the numerical methods presented herein can be easily implemented in commercial Finite Element software packages, where surface integrals are available, making it a suitable tool for investigating interparticle forces in acoustic manipulation devices.

Particle separation by phase modulated surface acoustic waves.

High efficiency isolation of cells or particles from a heterogeneous mixture is a critical processing step in lab-on-a-chip devices. Acoustic techniques offer contactless and label-free manipulation, preserve viability of biological cells, and provide versatility as the applied electrical signal can be adapted to various scenarios. Conventional acoustic separation methods use time-of-flight and achieve separation up to distances of quarter wavelength with limited separation power due to slow gradients in the force. The method proposed here allows separation by half of the wavelength and can be extended by repeating the modulation pattern and can ensure maximum force acting on the particles. In this work, we propose an optimised phase modulation scheme for particle separation in a surface acoustic wave microfluidic device. An expression for the acoustic radiation force arising from the interaction between acoustic waves in the fluid was derived. We demonstrated, for the first time, that the expression of the acoustic radiation force differs in surface acoustic wave and bulk devices, due to the presence of a geometric scaling factor. Two phase modulation schemes are investigated theoretically and experimentally. Theoretical findings were experimentally validated for different mixtures of polystyrene particles confirming that the method offers high selectivity. A Monte-Carlo simulation enabled us to assess performance in real situations, including the effects of particle size variation and non-uniform acoustic field on sorting efficiency and purity, validating the ability to separate particles with high purity and high resolution.