Interaction of Nd:YAG Laser Radiation with Bovine Serum Albumin Solution

In this paper, the effect of Nd:YAG laser radiation on the properties of the BSA protein is investigated. A solution with a protein concentration of 5 mg/ml was irradiated for 30 minutes. After a 5-minute and 30-minute exposure, absorption spectra were taken, the particle size in the solution was determined by dynamic light scattering (DLS), the refractive index was determined, and fluorescent maps were taken. Raman spectroscopy of proteins was also performed. The results showed that after irradiation, the absorption of the protein solution decreases in the spectral range corresponding to amino acid residues. In DLS experiments, it was shown that the peak corresponding to protein molecules decreases, and the peaks corresponding to large aggregates (>100 nm) grow. Raman spectroscopy has shown that there is a decrease in intensity at a wavelength of 1570 cm-1. There were no significant changes in the refractive indices and the shape of the fluorescent maps. The data suggest that partial denaturation of proteins took place

Electric Impedance Spectroscopy in Trees Condition Analysis: Theory and Experiment

Electric impedance spectroscopy is an alternative technology to existing methods that shows promising results in the agro-food industry and plant physiology research. For example, this technology makes it possible to monitor the condition of plants, even in the early stages of development, and to control the quality of finished products. However, the use of electric impedance spectroscopy is often associated with the need to organize special laboratory conditions for measurements. Our aim is to extract information about the state of health of the internal tissues of a plant’s branches from impedance measurements. Therefore, we propose a new technique using the device and model developed by us that makes it possible to monitor the condition of tree branch tissues in situ. An apple tree was chosen as the object under study, and the dependence of the impedance of the apple tree branch on the signal frequency and branch length was analyzed. The change in the impedance of an apple tree branch during drying was also analyzed. It was shown that, when a branch dries out, the conductivity of the xylem mainly decreases. The developed technique was also applied to determine the development of the vascular system of an apple tree after grafting. It was shown that the processing of the scion and rootstock sections with the help of cold atmospheric plasma and a plasma-treated solution contributes to a better formation of graft unions

Interaction of Nd:YAG Laser Radiation with Bovine Serum Albumin Solution

In this paper, the effect of Nd:YAG laser radiation on the properties of the BSA protein is investigated. A solution with a protein concentration of 5 mg/ml was irradiated for 30 minutes. After a 5-minute and 30-minute exposure, absorption spectra were taken, the particle size in the solution was determined by dynamic light scattering (DLS), the refractive index was determined, and fluorescent maps were taken. Raman spectroscopy of proteins was also performed. The results showed that after irradiation, the absorption of the protein solution decreases in the spectral range corresponding to amino acid residues. In DLS experiments, it was shown that the peak corresponding to protein molecules decreases, and the peaks corresponding to large aggregates (>100 nm) grow. Raman spectroscopy has shown that there is a decrease in intensity at a wavelength of 1570 cm-1. There were no significant changes in the refractive indices and the shape of the fluorescent maps. The data suggest that partial denaturation of proteins took place

Effect of Laser-Induced Optical Breakdown on the Structure of Bsa Molecules in Aqueous Solutions: An Optical Study

The influence of laser radiation of a typical surgical laser on the physicochemical properties of the Bovine Serum Albumin (BSA) protein was studied. It was established that the physicochemical characteristics of optical breakdown weakly depend on the concentration of protein molecules. At the same time, the patterns observed for an aqueous solution of BSA irradiated with a laser for different time periods were extremely similar to the classical ones. It was established that after exposure to laser radiation, the optical density of protein solutions increases. At the same time, the intensity of BSA fluorescence due to aromatic amino acid residues decreases insignificantly after exposure to laser radiation. In this case, the position of the excitation and emission maximum does not change, and the shape of the fluorescence spot on 3D maps also does not change significantly. On the Raman spectrum after exposure to laser radiation, a significant decrease in 1570 cm−1 was observed, which indicates the degradation of α-helices and, as a result, partial denaturation of BSA molecules. Partial denaturation did not significantly change the total area of protein molecules, since the refractive index of solutions did not change significantly. However, in BSA solutions, after exposure to laser radiation, the viscosity increased, and the pseudoplasticity of aqueous solutions decreased. In this case, there was no massive damage to the polypeptide chain; on the contrary, when exposed to optical breakdown, intense aggregation was observed, while aggregates with a size of 400 nm or more appeared in the solution. Thus, under the action of optical breakdown induced by laser radiation in a BSA solution, the processes of partial denaturation and aggregation prevail, aromatic amino acid residues are damaged to a lesser extent, and fragmentation of protein molecules is not observed

Ag₂O Nanoparticles as a Candidate for Antimicrobial Compounds of the New Generation

Antibiotic resistance in microorganisms is an important problem of modern medicine which can be solved by searching for antimicrobial preparations of the new generation. Nanoparticles (NPs) of metals and their oxides are the most promising candidates for the role of such preparations. In the last few years, the number of studies devoted to the antimicrobial properties of silver oxide NPs have been actively growing. Although the total number of such studies is still not very high, it is quickly increasing. Advantages of silver oxide NPs are the relative easiness of production, low cost, high antibacterial and antifungal activities and low cytotoxicity to eukaryotic cells. This review intends to provide readers with the latest information about the antimicrobial properties of silver oxide NPs: sensitive organisms, mechanisms of action on microorganisms and further prospects for improving the antimicrobial properties

Analysis of Fat and Protein Content in Milk Using Laser Polarimetric Scatterometry

Monitoring the composition of milk products is an important factor in the management of dairy farms and industry. Information on the quantitative content of milk components is necessary to control milk quality, as well as to optimize dairy cow nutrition and diagnose their clinical condition. The content of fat and protein is considered the main criterion for determining the market value of milk. Increasing the efficiency of dairy production requires the use of inexpensive and compact devices that are capable of performing multicomponent analysis of milk both directly on the farm and in technological lines. We investigated the possibility of fast simultaneous determination of fat and protein content in milk by laser polarimetric scatterometry. The block-diagonal elements of the scattering matrix were measured for a series of commercially produced milk samples with the indicated fat percentage, which were diluted by volume with water. From the measured scattering matrices, the size distributions of fat droplets and casein aggregates were reconstructed. Using the size histograms, the content of fat and protein and protein-to-fat ratio in the studied milk samples are estimated

Laser Scatterometric Device for Inline Measurement of Fat Percentage and the Concentration Level of Large-Scale Impurities in Milk

A compact laser scatterometric device for determining the fat percentage of milk filling a cylindrical tube has been designed. The device operates by detecting the angular distribution of the scattered radiation of a semiconductor laser using an axial array of photodiodes. We have experimentally found that the light-scattering indicatrix in cow milk has a monotonous dependence on milk fat content. The intensity at side- or forward-scattering angles normalized to the backscattering intensity proves to be a reliable, informative parameter. A polynomial approximation for the calibration curve of fat percentage versus normalized scattering intensity is constructed to enable fat content measurements in the fairly wide range of ~0.01–10%. Furthermore, the intensity at forward scattering angles responds to the presence of large-scale particles in milk. The device was tested in a laminar flow regime at milk flow rates up to 100 mL/s

Comparison of the Non-Invasive Monitoring of Fresh-Cut Lettuce Condition with Imaging Reflectance Hyperspectrometer and Imaging PAM-Fluorimeter

We compared two approaches to non-invasive proximal sensing of the early changes in fresh-cut lettuce leaf quality: hyperspectral imaging and imaging of variable chlorophyll fluorescence contained in the leaves. The estimations made by the imaging techniques were confronted with the quality assessments made by traditional biochemical assays (i.e., relative water content and foliar pigment (chlorophyll and carotenoid) composition. The hyperspectral imaging-based approach provided the highest sensitivity to the decline of fresh-cut lettuce leaf quality taking place within 24 h from cutting. Using of the imaging pulse-amplitude modulated PAM chlorophyll fluorometer was complicated by (i) weak correlation of the spatial distribution pattern of the Qy parameter with the actual physiological condition of the plant object and (ii) its high degree of heterogeneity. Accordingly, the imaging PAM-based approach was sensitive only to the manifestations of leaf quality degradation at advanced stages of the process. Sealing the leaves in polyethylene bags slowed down the leaf quality degradation at the initial stages (<three days) but promoted its rate at more advanced stages, likely due to build-up of ethylene in the bags. An approach was developed to the processing of hyperspectral data for non-invasive monitoring of the lettuce leaves with a potential for implementation in greenhouses and packing lines

Laser Scatterometric Device for Inline Measurement of Fat Percentage and the Concentration Level of Large-Scale Impurities in Milk

A compact laser scatterometric device for determining the fat percentage of milk filling a cylindrical tube has been designed. The device operates by detecting the angular distribution of the scattered radiation of a semiconductor laser using an axial array of photodiodes. We have experimentally found that the light-scattering indicatrix in cow milk has a monotonous dependence on milk fat content. The intensity at side- or forward-scattering angles normalized to the backscattering intensity proves to be a reliable, informative parameter. A polynomial approximation for the calibration curve of fat percentage versus normalized scattering intensity is constructed to enable fat content measurements in the fairly wide range of ~0.01–10%. Furthermore, the intensity at forward scattering angles responds to the presence of large-scale particles in milk. The device was tested in a laminar flow regime at milk flow rates up to 100 mL/s

Effect of the MPT Pore Inhibitor Alisporivir on the Development of Mitochondrial Dysfunction in the Heart Tissue of Diabetic Mice

Diabetes mellitus is a systemic metabolic disorder associated with mitochondrial dysfunction, with the mitochondrial permeability transition (MPT) pore opening being considered as one of its possible mechanisms. The effect of alisporivir, a non-immunosuppressive cyclosporin derivative and a selective inhibitor of the MPT pore opening, on the ultrastructure and functions of the heart mitochondria of mice with diabetes mellitus induced by a high-fat diet combined with streptozotocin injections was studied. The treatment of diabetic animals with alisporivir (2.5 mg/kg ip for 20 days) increased the rate of glucose clearance during the glucose tolerance test. The blood glucose level and the indicator of heart rate in alisporivir-treated diabetic mice tended to restore. An electron microscopy analysis showed that alisporivir prevented mitochondrial swelling and ultrastructural alterations in cardiomyocytes of diabetic mice. Alisporivir canceled the diabetes-induced increases in the susceptibility of heart mitochondria to the MPT pore opening and the level of lipid peroxidation products, but it did not affect the decline in mitochondrial oxidative phosphorylation capacity. The mRNA expression levels of Pink1 and Parkin in the heart tissue of alisporivir-treated diabetic mice were elevated, suggesting the stimulation of mitophagy. In parallel, alisporivir decreased the level of mtDNA in the heart tissue. These findings suggest that targeting the MPT pore opening by alisporivir alleviates the development of mitochondrial dysfunction in the diabetic heart. The cardioprotective effect of the drug in diabetes can be mediated by the induction of mitophagy and the inhibition of lipid peroxidation in the organelles