The Use of Flocked Swabs with a Protective Medium Increases the Recovery of Live Brucella spp. and DNA Detection

In order to protect public and veterinary health from highly zoonotic bacteria such as members of the genus Brucella and prevent their dissemination into the environment, direct diagnostics are of utmost importance. However, in addition to the highly specific diagnostic tests, the sampling methods, time necessary for specimens to reach the laboratories, and transport conditions are important factors to consider in order to increase the sensitivity of performed tests, especially bacterial culturing and qPCR.

Effects of residual stresses on the bending stiffness of shafts strengthened by enveloping de-formation

The aim was to study the effects of technological residual stresses on the bending stiffness of cylindrical parts of shafts and axes. Experiments were conducted for elongated cylindrical specimens made of steel grade 35 with a diameter of 30 mm using boring and turning methods. Specimens were annealed in a protective medium to remove initial residual stresses. Experiments were carried out using an Amsler laboratory hydraulic testing machine and VK8 grade hard-alloy matrices. The experiments showed that, for an extremely low degree of relative crimping of 0.1 to 0.5%, the size of the layer with tangential residual compression stresses gradually decreases. The stiffness of such cylindrical workpieces remains almost unchanged. An increase in relative crimping (from 0.5 to 1.2%) leads to a decrease in resi dual compression stresses on the part surface. The layer thickness with tangential residual compression stresses starts to increase. This leads to a decreased residual buckling and an increased bending stiffness. It was found that the degree of relative crimping has no effect on the variation of distribution depth of axial residual stresses. Optimal distribution of tangential residual compression stresses can be reached by increasing their depth. A linear relationship was found for relative crimping of 0.1 to 1.0%. The highest bending resistance was recorded for specimens strengthened by residual crimping of about 1.0%. By processing workpieces using enveloping deformation with crimping of 0.1% and loading them with a transverse force of 0.6 kN, bending distortion can be decreased and the strength of parts can be increased by 5 times. It was found that the bending stiffness of cylindrical shafts is greatly affected by residual compression stresses. The bedding depth of residual stresses has various effects on the stiffness of cylindrical parts. Thus, correct use of strengthening enveloping deformation can form a high-quality surface layer on parts with the pre-defined distribution of residual stresses.

Development of a Mathematical Model for a Workpiece Heating and Cooling in a Protective Medium while Treatment under Pressure

The paper reviews and develops the mathematical model of plastic flow during the hot-forming processes. A flat non-stationary temperature problem for a cross-section of a long solid (rolled product) of arbitrary shape with different heat transfer conditions along the perimeter of the cross-section was considered. Equations for calculation of the thermal conductivity coefficient and heat capacity of tungsten billets were obtained in the temperature range of 700 - 1500°C, based on the literature data. Analytical dependences in form of regression equations were obtained, allowing for computer calculations of physical specifications of 11x11 mm VA grade tungsten billets in form of temperature functions with accuracy sufficient for practical calculations.

Assessment of the viability of cultures of lactic acid microorganisms during their freezing and low-temperature storage

Relevance. A significant increase in microbiome-associated diseases, closely related to violations of the bacterial diversity and functions of the normal intestinal microbiota, dictates the need to develop and implement measures for the long-term preservation of individual representatives of the normal microbiota in order to create new strategies for modifying the composition of microbiomes.Methods. The influence of the technology of deep freezing and storage of intestinal isolates of lactic acid bacteria of 2 taxonomic groups isolated from poultry in the conditions of the Low-temperature automated storage of biological samples of the Departmental Collection of useful microorganisms for Agricultural purposes of the Russian Agricultural Academy (VKSM) on the MRS culture medium using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants was studied. The suspensions of the isolates were frozen at - 150 °C for 18 hours and then placed in an automated cryopreservation at -80 °C. Control of samples for safetyResults. The technology of cryofreezing of lactic acid bacteria on MRS-broth using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants allows preserving the viability, physiological and biochemical properties of intestinal isolates of lactic acid bacteria when stored for 18 months. All the protective media used (MRS-broth with glycerin 10 and 20%, MRS -broth with sucrose 10 and 20%) showed comparable results in the preservation of viability and acid-forming activity of Lactobacillus fermentum-2, Pediococcus pentosaceus 6p-3, Pediococcus pentosaceus 28p-1 isolates. Then the storage of Pediococcus pentosaceus isolate (28p-1) in a given parameter on a protective medium with 10 and 20% sucrose led to a decrease in the activity of acid formation.

DEVELOPMENT OF THE CONDITIONS FOR STORING THALLIUM AMALGAM

It has been established that lNH2SO4 solution and distilled water can be used as a protective medium for a long-term storage (30-40 days) of thallium amalgam of eutectic composition (8.6 mas.%), without sliming of its surface and an insignificant change of its concentration. An inverse dependence between the decomposition reaction rate and the ratio of the solution volume per unit of the contact surface (V:S), which corresponds to the height of the liquid layer (h) above the amalgam, is observed. At h ~ 2.5 cm and higher, the reaction rate becomes stabilized. The value of metal loss during its storage for 10-15 days does not exceed 0.5-1.0 mas.% of the initial thallium content in the amalgam. It has been shown that the rate of dissolution of thallium from amalgam is rather low, and in sulfuric acid solution it is only slightly higher than that in water with all S:V ratios. A similar picture is observed upon thallium amalgam decomposition in the same media in an open vessel; the difference consists only in a higher K value (Table 4). Thus, with S:V = 1:2.5, in an open vessel K in lNH2SO4 makes up 10,5.1011 mol/cm2.sec, and in H2O – 7.3.1011 mol/cm2.sec, whereas in a closed vessel K in lNH2SO4 makes up 1,9.1011 mol/cm2. sec, and in H2O – 1.5.1011 mol/cm2.sec. For 40 days of thallium amalgam (8.54 mas.%) storage in 1NH2SO4 the loss of thallium has been 1.3 mas.%, and in the distilled water - 1 mas.%. The quantity of the dissolved metal increases in proportion to the experiment duration, which is characteristic for a zero-order reaction, and this dependence is observed for all S:V ratios from 1:1 to 1:7. Besides, a possibility to use some saturated hydrocarbons, wherein no sliming of thallium amalgam occurs, as a protective wash liquid has been shown.

Optimization of Conditions for Human Bacterial Preparation for Biological Correction of Intestinal Microflora

Fecal microbiota transplantation (FMT) is now considered as an effective tool for the treatment of various GI pathologies. Fecal preparations are delivered both through the lower GIT (enema, colonoscopy) and upper (endoscopy, capsules). A common disadvantage of instrumental methods of administration is their high invasiveness associated with the risk of intestinal perforation and the use of anesthesia. Oral capsules are minimally invasive, comfortable and more aesthetic, so this method of drug delivery is gaining popularity. The main issue with the use of frozen feces (including the lyophilisate used in capsules) is its efficiency compared to the original material. During lyophilization, cells are exposed to stress factors such as low temperatures, water crystallization, osmotic stress, changes in pH, and dehydration. To reduce the likelihood of cell damage during lyophilization, protective media (lyo-protectants) are used. In this work sucrose, gelatin, and their combinations have been used as lyoprotectors. To estimate the number of microorganisms, a bacteriological study was carried out. The number of Bifidobacteria, Lactobacilli, and the total number of E.coli and Enterobacteriaceae was estimated. It was found that the lyophilized stool sample containing 10% sucrose as a protective medium had the highest number of viable cells. Also, the physical properties of the lyophilisate (its flowability) are convenient for preparing capsulated form. The molar ratios of short chain fatty acids (SCFAs) in the original fecal samples and lyophilisates were studied by gas chromatography. The molar ratios of major SCFAs (acetate, propionate and butyrate) were identical in the samples studied. The composition of the protective medium in which the lyophilized biomaterial corresponds to the original feces in terms of the number of "live" microorganisms has been proposed. According to its physical characteristics lyophilisate is convenient for capsules preparation.

Development of a microbiological preparation for crops based on Bacillus pumilus strains

Data of the microbial biopreparation development for protection and crop growth stimulation on the Bacillus bacteria basis are presented. Three B. pumilus strains isolated from the Altai region (the Russian Federation) plants rhizosphere were selected as active components of the bacterial preparation. L-bulone was chosen as the nutrient medium for flasks cultivation of the inoculum. A molasses-based nutrient medium was used to incubate the bacilli in a 15-liter fermenter. The finished microbial preparation was obtained in dry form. The biopreparation is a powder consisting of a lyophilically dried concentrates mixture of genus Bacillus spores. Bacilli biomass were pre-mixed with a protective medium based on gelatin and sucrose. The final number of bacteria in the microbial preparation is 1.29(±0.30) ×1012 CFU/g.

DEVELOPMENT OF THE BIOTECHNOLOGY OF STREPTOCOCCUS THERMOPHILUS BACTERIA AS PRODUCERS OF EXOPOLYSACCHARIDESDEVELOPMENT OF THE BIOTECHNOLOGY OF STREPTOCOCCUS THERMOPHILUS BACTERIA AS PRODUCERS OF EXOPOLYSACCHARIDES

On carrying out a screening, phage-resistant strains of Streptococcus thermophilus have been selected. As producers of exopolysaccharides, they can be used to form the texture of fermented milk and improve the rheological properties of fermented milk products in a natural, effective, and safe way. It has been suggested to use analysis of the capsule-formation of strains as an express method to evaluate the rheological properties. The technology of the bacterial concentrate Iprovit – Streptococcus thermophilus with phage-resistant producers of exopolysaccharides has been developed. The following technological modes were used: growing in a growth medium with the ratio of carbohydrates to soluble nitrogen C:N=3.5; biomass stabilisation (10% inulin protective medium, freezing at minus 60±1°C for 16±2 h, drying for 24±2 h to 32±1°C, moisture content in the preparation not more than 5%). These modes allowed obtaining 7.83±0.02 g of bacterial concentrate from 1 dm3 of the growth medium. Depending on the strain of Streptococcus thermophilus, the dry bacterial concentrate contained 4.4×1011–1.1×1011 CFU/g of active microbiota. A technique has been developed that allows improving the rheological properties of fermented milk products by blending bacterial preparations to produce various products with concentrate of the Streptococcus thermophilus strain. The optimal formulations of the mixtures have been selected. This has made it possible to modify the rheological characteristics of fermented products without using other thickeners. The effective viscosity of the products obtained has been increased by 13.3–54.3%, depending on the formulation of the mixture. The biotechnology of the bacterial concentrate Iprovit – Streptococcus thermophilus was implemented at the State Research Enterprise of the Institute of Food Resources, National Academy of Agricultural Sciences of Ukraine. Manufacture of the concentrate is regulated by the regulatory documents developed and approved: TU 15.5-00419880-100:2010 “Dry and liquid fermenting cultures. Specifications,” Technological Instructions for production of the fermented cultures IPROVIT for TU 15.5-00419880-100:2010 “Dry and liquid fermenting cultures. Specifications.” The novelty of the technological solutions was confirmed by Copyright Registration Certificate No. 51033.

Masker sebagai Pencegah Gangguan Pernapasan pada Pekerja (Studi Kasus PT GUNUNG SUBUR SEJAHTERA Karanganyar)

Dust and tea powder produced negatively impact the health of the respiratory tract. Workers in the production department at PT Gunung Subur Sejahtera tea factory have the potential to experience respiratory problems because they are often exposed to tea dust and powder. The writing of this article aims to identify the role of masks as a deterrent to respiratory problems in workers at PT Gunung Subur Sejahtera. The research method used is descriptive qualitative case study approach in workers' environment at PT Gunung Subur Sejahtera, Karanganyar. The results showed that disposable masks commonly used by workers in tea companies had three layers of protection that were able to filter particles up to 0.1 µmv so that they were effective in preventing bacteria, viruses, and especially dust particles that were inhaled with respiratory air. By using masks when working, workers is able to minimize the intensity of exposure to dust particles that can be inhaled. In addition to the intensity of the exposure, the particle size that might escape the mask becomes small. Thus, the mask can be used as an effective personal protective medium to reduce the risk of respiratory distress in the workforce.