Application of Unsupervised Multivariate Analysis Methods to Raman Spectroscopic Assessment of Human Dental Enamel

This work explores the suitability of data treatment methodologies for Raman spectra of teeth using multivariate analysis methods. Raman spectra were measured in our laboratory and obtained from control enamel samples and samples with a protective treatment before and after an erosive attack. Three different approaches for data treatment were undertaken in order to evaluate the aptitude of distinguishing between groups: A—Principal Component Analysis of the numerical parameters derived from deconvoluted spectra; B—PCA of average Raman spectra after baseline correction; and C—PCA of average raw Raman spectra. Additionally, Hierarchical Cluster Analysis were applied to Raman spectra of enamel measured with different laser wavelengths (638 nm or 785 nm) to evaluate the most suitable choice of illumination. According to the different approaches, PC1 scores obtained between control and treatment group were A—50.5%, B—97.1% and C—83.0% before the erosive attack and A—55.2%, B—93.2% and C—87.8% after an erosive attack. The obtained results showed that performing PCA analysis of raw or baseline corrected Raman spectra of enamel was not as efficient in the evaluation of samples with different treatments. Moreover, acquiring Raman spectra with a 785 nm laser increases precision in the data treatment methodologies.

PROTECTIVE WOOD TREATMENT WITH AN OLIGOMER CONTAINING STYRENE UNITS

Currently, much attention is paid to the protective treatment of wood materials. This allows you to protect wood from adverse factors and extend the service life of products based on it. At the same time, not a little, an important criterion is the ratio of the price of the protective composition and its quality. The article discusses the possibility of using an oligomer for the protective treatment of natural wood, obtained on the basis of by-products of the production of polybutadiene and modified with secondary polystyrene. Considering the fact that this waste has not found its application, its use makes it possible to obtain not only valuable and affordable compositions based on it, but also to solve a number of environmental problems. For the modification, an oligomer with a bound styrene content of about 50% was used. The process was carried out at 200°C in the presence of a desiccant. At high temperatures and in the presence of atmospheric oxygen, destruction of both oligomer and secondary polystyrene occurs. The resulting destruction products interact with each other with the formation of new macromolecules containing an increased amount of styrene groups and the appearance of functional groups containing oxygen in the polymer chains. Protective treatment of natural wood with the obtained impregnating compounds allows to reduce water absorption and swelling of birch samples. This treatment allows you to extend the life of wood products.

Ways to improve the properties of natural wood when using waste vegetable oils

The article is devoted to the development and study of new compositions based on spent sunflower oil for the protective treatment of natural wood. Samples of birch and aspen wood were selected as the subjects of the study. The processing of wood samples was carried out by the method of “hot-cold impregnation”. Refined sunflower oil was used as the oil base of the propearized compounds developed. Plant oil fillers were chosen wood flour, stearic acid, canifol and sikkativ based on metal salts. The use of developed compounds can improve the hydrophobic properties of wood, increase its water and water resistance, as well as reduce swelling in tangential and radial directions. The optimal compositions on the basis of spent vegetable oil for protective processing of birch wood have been selected. The difference in the modifying capacity of the developed compositions for different types of wood is shown on the example of birch and aspen. Propiary compounds based on spent vegetable oil have environmental safety and their use allows the disposal of food waste.

Protective and Curative Effects of Trichoderma asperelloides Ta41 on Tomato Root Rot Caused by Rhizoctonia solani Rs33

Two molecularly identified tomato isolates, Trichoderma asperelloides Ta41 and Rhizoctonia solani Rs33, were characterized and antagonistically evaluated. The dual culture technique showed that Ta41 had a high antagonistic activity of 83.33%, while a light microscope bioassay demonstrated that the Ta41 isolate over-parasitized the pathogen completely. Under greenhouse conditions, the application of Ta41 was able to promote tomato plant growth and had a significant increase in plant height, root length, and shoot fresh, shoot dry, root fresh, and root dry weight. It also improved chlorophyll content and total phenol content significantly, both in protective and in curative treatments. The protective treatment assay exhibited the lowest disease index (16.00%), while the curative treatment showed a disease index of 33.33%. At 20 days post-inoculation, significant increases in the relative expression levels of four defense-related genes (PR-1, PR-2, PR-3, and CHS) were observed in all Ta41-treated plants when compared with the non-treated plants. Interestingly, the plants treated with Ta41 alone showed the highest expression, with relative transcriptional levels of CHS, PR-3, PR-1, and PR-2 that were, compared with the control, 3.91-, 3.13-, 2.94-, and 2.69-fold higher, respectively, and the protective treatment showed relative transcriptional levels that were 3.50-, 3.63-, 2.39-, and 2.27-fold higher, respectively. Consequently, the ability of Ta41 to promote tomato growth, suppress Rs33 growth, and induce systemic resistance supports the incorporation of Ta41 as a potential bioagent for controlling root rot disease and increasing the productivity of crops, including tomatoes.

THE PROSPECT OF USING A-VINYLNAPHTHALENE FOR MODIFICATION OF WOOD MATERIALS

Natural wood is the most common natural polymer material that is affordable, non-toxic and widely used in various fields of industry and construction. However, wood also has disadvantages, to eliminate which it is modified with the use of organic and inorganic agents, oligomers and polymers that can protect it from external factors. The paper studies the possibility of using such a vinylaromatic monomer as α-vinylnaphthalene for modification and protective treatment of natural birch wood. It is shown that during processing in the conductive elements of birch wood under the influence of elevated temperatures, the polymerization of α-vinyl naphthalene proceeds by a radical mechanism. However, 100 % conversion of α-vinylnaphthalene and polyvinylnaphthalene cannot be achieved. Thus, the conductive elements of natural wood contain a composite consisting of α-vinyl naphthalene and polyvinyl naphthalene. It is shown that with an increase in the content of the proposed modifier in birch wood, water absorption and swelling of wood-polymer-monomer composite samples significantly decreases. This will increase the service life of products based on modified wood. The introduction of the proposed technology for modifying low-value wood species will contribute to the conservation of forest resources and their rational use

PREVALENCE OF WHITE ROT IN VINEYARDS OF ROSTOV REGION

Information is provided on the prevalence and intensity of development of white rot on plants of different vine varieties during the growing season 2019–2020. It was found that the intensity of development of white rot var-ied from year to year. The meteorological conditions in 2019 contributed to the in-creased harmfulness of white rot: hot weather in June with air temperatures up to 37.2 °C, causing sunburn in plants, as well as moder-ately hot weather in July with frequent, albeit abundant precipitation, contributed to the de-velopment of white rot on plants of unstable varieties. In 2020, the intensity of infection by the pathogen did not exceed 1 point in most varieties, since the decrease in the harm-fulness of white rot in 2020 was facilitated not only by the corresponding meteorological conditions, but also by timely protective treatment of plants against white rot. Signs of white rot both in 2019 and in 2020 were ob-served in varieties: Riesling Reinsky, Olkhov-sky, Neizvestniy Donskoy, Krasnostop Zolotovsky. The absence of signs of damage by the phytopathogen was noted in the varie-ties: Burgunskiy, Buriy, Nakutvneuli, Pocha-tochniy, Tavrosi, Tashkentsky.

Focus on radioiodine-131 biokinetics: the influence of methylprednisolone on intratherapeutic effective half-life of 131I during radioiodine therapy of Graves’ disease

Aim Radioiodine therapy (RIT) may trigger the development of Graves’ ophthalmopathy (GO) or exacerbate pre-existing subclinical GO. Therefore, glucocorticoid administration is recommended for patients with pre-existing GO. Aim of this study was to analyze the influence of glucocorticoid therapy with methylprednisolone on intratherapeutic effective half-life (EHL) of radioiodine-131 in patients with Graves’ disease (GD) as recent studies showed an effect for prednisolone. Methods In a retrospective study, 264 patients with GD who underwent RIT without any additional antithyroid medication were evaluated. Intrathyroidal EHL was determined pre- and intratherapeutically. Patients with co-existing GO (n = 43) received methylprednisolone according to a fixed scheme starting 1 day prior to RIT, patients without GO (n = 221) did not receive any protective glucocorticoid medication. The ratios of EHL during RIT and during radioiodine uptake test (RIUT) were compared. Results Patients receiving methylprednisolone showed a slight decrease of the mean EHL from 5.63 d (RIUT) to 5.39 d (RIT) (p > 0.05). A comparable result was obtained in patients without glucocorticoids (5.71 d (RIUT) to 5.47 d (RIT); p > 0.05). The ratios of the EHL between RIT and RIUT failed to show a significant difference between the two groups. EHL is therefore not significantly influenced by an additional protective treatment with methylprednisolone. Conclusions In the present study a decreased intrathyroidal EHL under glucocorticoid medication with methylprednisolone could not be detected. Therefore, co-medication with methylprednisolone in patients with GO may be preferred to avoid an intratherapeutic decrease of EHL by accompanying protective glucocorticoides.

Evaluation of Protective and Therapeutic Potentials of Aqueous Extract of Corn Silk on Gentamicin-Induced Nephrotoxicity in Albino Rats

Aim: To evaluate the protective and therapeutic potentials of corn silk extract on gentamicin (CN)-induced nephrotoxicity in albino rats. Study Design: The rats were randomly selected and grouped as follows: Group 1 (NC): Were given only food and water. They served as negative control. Group 2 (PC): Were treated with 80 mg/kg/day of CN over a period of 7 days. They served as the positive control. Protective Treatment: Group 3a (CN+CSP 200 mg/kg): Concurrently treated with 200 mg/kg corn silk extract and 80 mg/kg/day of CN for 7 days. 200 mg/kg corn silk extract continued for 30 days. Group 3b (CN+CSP 400 mg/kg): Concurrently treated with 400 mg/kg corn silk extract and 80 mg/kg of CN for seven days. 400 mg/kg corn silk extract continued for 30 days. Therapeutic treatment: Group 4a (CN+CST 200 mg/kg): Induction of nephrotoxicity with 80 mg/kg/day of CN for seven days before the administration of 200 mg/kg of corn silk extract for 30 days. Group 4b (CN+CST 400 mg/kg): Induction of nephrotoxicity with 80 mg/kg/day of CN for 7 days before the administration of 400 mg/kg of corn silk extract for 30 days. Methodology: At the end of the treatment, the animals were allowed to fast for 18 hours and later anaesthetized using chloroform. Whole blood samples were collected via cardiac puncture and put into lithium heparin bottles. The samples were then spun at 3500 rpm for 5 minutes to obtain plasma. Kidney specimens harvested were fixed in 10% formol saline. Sections were prepared using histological techniques and stained using Haematoxylin and Eosin stain. Urea was analysed using Berthelot’s enzymatic colorimetric method, creatinine using Jaffe’s enzyme-kinetic method while the estimation of Na+, K+, and Cl- were performed using Ion Selective Electrode (ISE) analyzer. Results: Significantly lower (p<0.05) values of creatinine and urea were seen in protective and therapeutic treatment groups when compared against positive control. Potassium indicated significantly lower values especially in the therapeutic groups when compared against negative control while chloride indicated significantly higher values in 400 mg/kg rats compared with positive control at p<0.05. Histology of the protective treatment groups showed slightly distorted glomerular space, vacuolations, and dilated proximal and distal tubules. The positive control and the therapeutic treatment groups indicated severely damaged glomerulus, glomerular space, proximal and distal tubules as well as loss of parenchymal materials and presence of kupffer cell infiltration were seen but less severe in the therapeutic group compared to the positive control. Conclusion: The results obtained suggest protective and therapeutic potentials of corn silk extract on gentamicin-induced nephrotoxicity in albino rats. However, the therapeutic efficacy was progressively gradual and not be fast-effective as documented in most traditional or herbal literatures.