Density Of Medium Research Articles

A Three-Dimensional Model of Bacterial Biofilms and Its Use in Antimicrobial Susceptibility Testing.

(1) Background: The discrepant antimicrobial susceptibility between planktonic and biofilm bacterial modes poses a problem for clinical microbiology laboratories and necessitates a relevant 3D experimental model allowing bacteria to grow in biofilm mode, in vitro, for use in anti-biofilm susceptibility testing. (2) Methods: This work develops a 3D biofilm model consisting of alginate beads containing S. aureus biofilm and encased within two thick layers of alginate matrix. The constructed model was placed on a thin Boyden chamber insert suspended on a 24-well culture plate containing the culture medium. The antibacterial activity of bacitracin and chlorhexidine digluconate (CD), either combined or separately, against 2D S. aureus culture was compared to that in the 3D biofilm model. Quantitative analysis and imaging analysis were performed by assessing the bacterial load within the matrix as well as measuring the optical density of the culture medium nourishing the matrix. (3) Results: The 3D biofilm model represented the typical complex characteristics of biofilm with greater insusceptibility to the tested antimicrobials than the 2D culture. Only bacitracin and CD in combination at 100× the concentration found to be successful against 2D culture were able to completely eliminate the 3D biofilm matrix. (4) Conclusions: The 3D biofilm model, designed to be more clinically relevant, exhibits higher antimicrobial insusceptibility than the 2D culture, demonstrating that the model might be useful for testing and discovering new antimicrobial therapies. The data also support the view that combination therapy might be the optimal approach to combat biofilm infections.

Weed density evaluation using KCCA-CFBLS based on fusion of visual and tactile features in special paddy field environment

Accurately evaluating weed density in paddy fields is crucial for achieving high-quality control of rice weeds, as it enables precise application of herbicides or matching of mechanical weeding intensity. However, visual methods alone may not provide ideal classification of weed density in specialized paddy field environments due to complex backgrounds, environmental interference, and visual occlusion. In this study, we propose an innovative method that combines vision and tactile features to achieve accurate weed density evaluation. We first obtained tactile data containing weed density information using a self-made tactile sensor, while simultaneously capturing corresponding visual images. We then utilized the kernel canonical correlation analysis (KCCA) algorithm to maximize the correlation of discriminating features extracted from the tactile data and visual images, and obtained fusion eigenvectors that characterize the weed density. These eigenvectors were used as input for a broad learning system (BLS), in which the random feature mapping was replaced by a cascade feature node to construct a KCCA-based cascade feature broad learning system (KCCA-CFBLS). Our method achieved accurate evaluation of weed density in low, medium, and high weed conditions using a novel weed dataset from a specialized paddy field environment. We analyzed the accuracy and running time, and found that KCCA-CFBLS outperformed methods based on SVM and YOLOv5-Lite, achieving 11.56% and 7.56% higher accuracy, respectively, with less time consumption. Experimental results demonstrated significant advantages of our method in terms of accuracy and real-time performance compared to visual methods, providing a decision-making basis for the implementation of intelligent chemical and mechanical weeding in specialized paddy field environments.

Radiative cooling face mask based on mixed micro- and nanofibrous fabric

A type of personal protective face mask with thermal comfort function is developed based on the radiative cooling concept. We show that the cooling face mask, with the combination of PLA meltblown microfibers and a thin sheet of mixed electrospun micro- and nanofibers as filtration media and a silk fabric as inner supporting layer, can provide high reflectivity (>85 %) in the solar spectrum and high emissivity (>96 %) in the atmospheric window. Outdoor measurement of simulated skin temperature demonstrates the skin covered by our cooling mask could be ∼ 2.7℃ lower than that covered by commercial 3 M N95 mask. Our cooling mask exhibits excellent filtration performance with 99.98 % filtration efficiency and < 110 Pa pressure drop because of the reduced stacking density of the filtration media. This research has the potential of developing thermal management textiles.

Tuning plasmid DNA amounts for cost-effective transfections of mammalian cells: when less is more

Transient gene expression (TGE) in mammalian cells is a well-known approach to the fast expression of recombinant proteins. The human cell line HEK (human embryonic kidney) 293F is widely used in this field, due to its adaptability to grow in suspension to high cell densities in serum-free media, amenability to transfection, and production of recombinant proteins in satisfactory quantities for functional and structural analysis. Amounts of plasmid DNA (pDNA) required in transfections for TGE remain high (usually 1 µg pDNA/mL, or even higher), representing a noticeable proportion of the overall cost. Thus, there is an economic need to reduce amounts of coding pDNA in TGE processes. In this work, amounts of both pDNA and transfecting agent used for TGE in HEK 293F cells have been explored in order to reduce them without compromising (or even improving) the productivity of the process in terms of protein yield. In our hands, minimal polyethyleneimine (PEI) cytotoxicity and optimum protein yields were obtained when transfecting at 0.5 µg pDNA/mL (equal to 0.5 µg pDNA/million cells) and a DNA-to-PEI ratio of 1:3, a trend confirmed for several unrelated recombinant proteins. Thus, carefully tuning pDNA and transfecting agent amounts not only reduces the economic costs but also results in higher recombinant protein yields. These results surely have a direct application and interest for the biopharmaceutical industry, always concerned in increasing productivity while decreasing economic costs.Key points• Mammalian cells are widely used to produce recombinant proteins in short times.• Tuning DNA and transfecting agent are of great interest to optimize economic costs.• Reducing DNA and transfecting agent amounts result in higher protein yields.Graphical

PeVatron candidate SNR G106.3+2.7 in a low-density cavity: a multiwavelength test

ABSTRACT In this paper, we constrain the density of the interstellar medium (ISM) around the hadronic PeVatron candidate, supernova remnant (SNR) G106.3+2.7, based on X-ray and γ-ray observations. The purpose of this investigation is to understand the influence of the gaseous environment on this SNR as a proton PeVatron candidate. By modelling the self-regulated propagation of the cosmic rays (CRs) injected from the SNR, we calculate the γ-ray emission of CRs via the hadronuclear interactions with the molecular cloud and the ISM, and use the measured γ-ray flux to constrain the ISM density around the SNR. Our results support the picture that the SNR is expanding into a low-density ($\lt 0.05\, {\rm cm}^{-3}$) cavity, enabling the SNR to be a potential proton PeVatron despite that it is presently not in the very early phase.

Effects of Rock Covering on Underlying Engineered Media in Bioretention Practices in Middle Tennessee, USA

AbstractBioretention practices have become a common way to protect natural waterways in urban and suburban landscapes across the United States. However, optimal design, implementation, operation, and maintenance are still in need of study. A field survey of 52 bioretention practices was conducted in Davidson County, Tennessee, to address research questions related to operation and maintenance. A suite of site conditions were documented, such as size, signs of erosion, and dominant surface cover. Samples were collected from the surface of the engineered media layer and analyzed for organic matter content and bulk density. Vegetation was described in terms of dominant species and canopy cover. On average, the organic matter content of media under plant‐based mulch cover was significantly greater than that under rock cover (p = 0.002). Bulk density of the surface media is strongly and inversely correlated to organic matter content; bulk density did not generally vary with bioretention area age and was highly variable within treatments. On average, the bulk density of the media under the plant‐based mulch cover was significantly less than that under the rock cover. Media under the composite treatments had similar bulk density to both the plant‐based mulch (p = 0.233) and the rock covers (p = 0.132). Plant canopy did not surpass 70% in practices with bulk density values above 1.55 g/cm3. These results suggest that consideration should be made regarding the tradeoffs between utilizing rock coverings and potential for plant establishment impacts.

Биотехнологический потенциал молочнокислых бактерий при ферментации растительной основы альтернативного напитка из полбы

The properties of Lactobacillus acidophilus BZ-AB culture, strains of Limosilactobacillus fermentum B28, Lactiplantibacillus рlantarum B4, and their mixtures were studied in order to select cultures ensuring the optimal biotechnological process and to obtain a fermented alternative drink from high-quality emmer. The saccharolytic activity of bacteria was assessed by the rate of the changes in the optical density of the Gis medium with soluble sugars at a wavelength of 490 nm. The acid-forming activity of the cultures was determined by the dynamics of the pH of the fermented mixture. The number of bacterial cells was calculated by the Vinogradsky–Brid method. The organoleptic properties of the hydrolysate were assessed on a pre-developed five-point scale. It has been shown that lactic acid bacteria require soluble sugars for effective development. Their growth is provided by emmer flour hydrolysate with a maltose content of 23.66 g/dm3, glucose content of 9.90 g/dm3, and alpha-amine nitrogen content of 85.48 mg/100 g ensures, and it can be used as a vegetable base of a fermented beverage. It was found that, during fermentation of emmer hydrolysate, Lb. acidophilus BZ-AB lowers the pH level of the mixture to 4.5 ±0.1 for 5 hours, Lpb. plantarum B4 and Lilb. fermentum B28 – for 6 and 8 hours, accordingly, and a mixture of Lpb. plantarum B4 + Lilb. fermentum B28 in a ratio of 1:1 – for about 5.5 hours. The number of all the cultures in the fermented emmer flour hydrolysate reached the level of 109 cell/cm3. Mixing Lpb. plantarum B4 and Lilb. fermentum B28 in a ratio of 1:1 leads to an increase in the rate of acid formation and an increase in the number of cells compared with pure cultures commensurate with the indicators of Lb. acidophilus BZ-AB, as well as to achieve significantly higher scores of falvour for fermented hydrolysate. It has been established that Lb. acidophilus BZ-AB, Lpb. plantarum B4, and the mixture of Lpb. plantarum B4 and Lilb. fermentum B28 can be used for the fermentation of the plant base from emmer. The mixture of Lpb. plantarum B4 and Lilb. fermentum B28 has the highest biotechnological potential.

Difference between arterial and venous peak optical density after thrombectomy is associated with functional outcomes.

The density of contrast medium in digital subtraction angiography (DSA) have been used to evaluate the cerebral circulation function. Our aim was to study the effect of difference in arteriovenous peak optical density (POD) after thrombectomy on functional outcomes. Consecutive patients with acute ischemic stroke due to large vessel occlusion who underwent thrombectomy were reviewed. We processed DSA images with ImageJ software to measure the POD of internal carotid artery (ICA) and cortical veins. The average POD of cortical veins (PODVA) and the POD difference between ICA and cortical veins (PODICA-CV) were calculated. Primary outcome was good functional outcome (modified Rankin scale score of 0-2 at 90 days). One hundred sixty-six patients were finally included in the study. Patients with good functional outcome had lower ipsilateral PODVA (median [interquartile range (IQR)], 257.198 [216.623-296.631] vs. 290.944 [248.647-338.819], p < 0.001) and lower ipsilateral PODICA-CV (median [IQR], 128.463 [110.233-153.624] vs. 182.01 [146.621-211.331], p < 0.001). Multivariable logistic regression analyses showed that ipsilateral PODVA (odds ratio [OR] 0.991, 95% confidence interval [CI] 0.984-0.999, p = 0.019) and ipsilateral PODICA-CV (OR 0.975, 95% CI 0.963-0.986, p < 0.001) were associated with good functional outcome. The predictive ability was significantly enhanced in the model including ipsilateral PODICA-CV (0.893 vs. 0.842, p = 0.027). No correlation was found between ipsilateral PODICA-CV and expanded Thrombolysis in Cerebral Infarction grades (r = -0.133, p = 0.099). Ipsilateral PODICA-CV is an additional indicator of cerebral reperfusion status and predicts functional outcomes after thrombectomy.

In situ analysis of a boron-based catalytic electrode with trace platinum for efficient hydrogen evolution in a wide pH range

An efficient Pt-NiB@NF catalytic electrode is rapidly constructed by mild electroless plating and electroplating. It demonstrates long-term stability at industrial-scale current densities in neutral high-salt media and alkaline systems.

AuAgCu trimetallic nanoparticles based alloy: an advanced electrocatalyst for hydrogen evolution reaction in alkaline media.

Hydrogen production via cost-effective electrochemical water splitting is one of the most promising approaches to confront the energy crisis and to obtain clean fuels with high energy density. To address this concern, herein, we developed a simple one-step synthesis method for creating an AuAgCu trimetallic alloy using aspirin as a capping agent. This alloy shows potential for efficient electrocatalyst for hydrogen evolution reaction. The trimetallic nanoparticles based alloy exhibit an equiaxed grain-like morphology and a face-centred cubic phase. In HER experiments using a 1 M KOH electrolyte, the AuAgCu alloy shows nearly negligible overpotential compared to mono- and bimetallic catalysts, and the Tafel slope was 32.7 mV dec-1, which is the lowest ever achieved for alloy-based electrocatalysts and extremely close to a commercially available Pt/C with high stability for 21 days and no decrease in current density in alkaline media. Besides, with excellent HER activity and stability, the trimetallic AuAgCu-modified electrode possessed significant durability for over 1000 cycles in the selected range of potential from 0.5 to 0.8 V at different scan rates from 1 to 100 mV s-1. This simple, cost-effective and environmentally friendly methodology can pave the way for the exploitation of mixed metal alloy-based electrocatalysts not only for water splitting but also for other applications, such as fuel cells, lithium-ion batteries and supercapacitors.

Biochemical and Fe-resistant characteristics of indigene bacteria from a high iron concentration landfill in Indonesia

Bacteria isolated from leachate with high heavy metal concentration mostly have potential for bioremediation. The aim of this study was to isolate bacteria from leachate of a landfill containing high concentration of Fe. The leachate sample was collected from Gampong Jawa Landfill, Aceh, Indonesia and used to isolate the bacteria by spread method. The purification of the isolates was carried out through four quadrant plate method. Pure isolates were characterized based on the microscopic or macroscopic appearance and biochemical tests. Fe-resistance was tested by disc diffusion method and constructing the growth curve based on the optical density of broth culture media. A total of 27 pure isolates were obtained and identified, representing eight different genera: Pseudomonas, Bacillus, Neisseria, Micrococcus, Staphylococcus, Proteus, Acinetobacter, and Escherichia. Of eight isolates (each genus was represented by a single isolate), Pseudomonas sp. and Bacillus sp. were considered resistant to Fe exposure (15 ppm) with inhibition zones of 1.00 and 0.81 mm, respectively. At Fe concentration of 20 ppm the inhibition zones exceeded 1 mm, but Bacillus sp. had smaller inhibition zone than that of Pseudomonas sp. (1.15 mm versus 2.86 mm). Growth inhibition of Bacillus sp. was concentration-dependent on Fe exposure but could survive at Fe exposure up to 20 ppm. In conclusion, Bacillus sp. had a resistance against Fe exposure and its bioremediation potential is subjected for future studies.

Low-cost spirulina manufacturing technique by using supernatant of digested rotten ladies finger (Abelmoschus esculentus)

The goal of the study was to assess the culture method and spirulina (Spirulina platensis) production in the supernatant of three distinct digested rotting ladiesfingers, using Kosaric medium (KM) as the control. Two hundred gram rotten ladies finger was allowed to digestion in 4.0 L distilled water using aeration in 5.0 L glass jar.After 30 days, almost colorless supernatant was found, screened through 300 μm net and added with 9 g/l NaHCO3, 0.20 g/l urea and 0.50 ml/Lmicro nutrients. Three different concentrations such as 25, 50 and 75% of supernatant with three replications were prepared. Next, three digested rotten ladies finger medium (DRLFM) treatments were infected with 10% spirulina (at OD620 = 0.20) to develop. It was recorded that spirulina grew well at 12thday and then it was found to fall and continued up to 18thdays. The cell weight of spirulina attained a maximum of 16.45 ± 0.78 mg/L (dry weight basis) in KM followed by 13.785 ± 0.643, 10.354± 0.233 and 2.738 ± 0.177 mg/L in supernatant of 50, 75 and 25% DRLFM, respectively on the 12thday of culture. Similar trend wasalso observed in optical density of media, content of chlorophyll a(mg/L), total biomass (mg/L), particular growth rate of spirulina (based on cell weight and chlorophyll a). It could be concluded that mass culture of S. platensis may be done in supernatant of 50% digested rotten ladies finger media.

Experimental study on the performance enhancement of PV/T by adding graphene oxide in paraffin phase change material emulsions

Traditional water-based PV/T systems have low heat storage density, high PV backsheet temperatures, and low energy utilization in practical applications. In this work, nanoparticles were applied to improve thermal conductivity and simultaneously emulsions were added to enhance energy storage density of the conventional heat transfer media. Furthermore, the synergistic effect of nanocomposite Phase Change Material Emulsions (PCME) as the heat transfer medium on the thermoelectric efficiency of PV/T was studied in a real system. Specifically, the water-based 30 % paraffin emulsions with graphene oxide (GO) concentration of 0.01, 0.02 and 0.03 wt% were prepared by ultrasonic stirring and their thermophysical properties were characterized. The results show that the 30 wt% paraffin emulsion with addition of 0.02 wt% GO has the phase change temperature of 35 °C, latent heat of 42.93 J/g, thermal conductivity of 0.505 W/(m·K) and viscosity coefficient of 0.91. It shows the thermal efficiency of the paraffin/GO emulsion increased by 92.28 %, the electrical efficiency increased by 8.87 %, the comprehensive efficiency increased by 45.75 %, and 15.8 % increase in heat collection for the heat exchange tank in comparison with the water. It is concluded application of PCME would improves the thermoelectric performance of the system than traditional water-based PV/T systems.

Features of the coefficient of variation of parameters of the gas environment in fire in the premises

The object of the study is the selective coefficient of variation of dangerous parameters of the gas environment during the ignition of materials. The measure of the sample coefficient of variation of an arbitrary hazardous parameter of the gas environment observed at an arbitrary time interval is substantiated. The representativeness error of the measure of the sampling coefficient of variation, which depends on the value of the measure and the sample size, was determined. The measure allows you to numerically determine its value for an arbitrary observation interval. The difference in the measure at the intervals corresponding to the reliable absence and occurrence of ignition allows to detect the occurrence of ignition of the material. According to the results of laboratory studies, the measures of the sample coefficient of variation for carbon monoxide concentration, smoke density, and temperature of the gas medium in the laboratory chamber at intervals of absence and appearance of ignition of alcohol, paper, wood, and textiles were determined. It was established that the dangerous parameters of the gas environment at the intervals of absence and presence of ignition are characterized by different values of the increase in the measure of the sample coefficient of variation. For example, it is determined that the ignition of alcohol causes the maximum increase in the measure for carbon monoxide concentration from 0.135 to 0.441, for smoke density from 0.629 to 0.805, and for temperature from 0.001 to 0.115. When paper catches fire, the measure for carbon monoxide concentration and temperature increases from 0.0026 to 0.140 and from 0.0019 to 0.05, respectively. When burning wood, the measure for carbon monoxide concentration and temperature increases from 0.0072 to 0.177 and from 0.0067 to 0.016, respectively. The obtained results, provided that the hazardous parameters of the gas environment in the premises are measured and the sample coefficient of variation is calculated in practice, make it possible to use them in the creation of early fire detection systems

Electrocoagulation Technique for Treating Swine Slaughterhouse Wastewater from Batch to Semicontinuous Operation Mode

In this study, industrial swine slaughterhouse wastewater was treated by electrocoagulation process using batch and semicontinuous operation systems. Electrochemical technique was carried out in batch operation mode during 2.5 h applying different current densities in sulfate and chloride media. After finding the best operating parameters in batch mode (lab-scale), the process was transferred to a semicontinuous pre-pilot scale process using a filter-press FM01-LC type electrochemical reactor fitted with flat plate aluminum electrodes. In this stage, distinct current densities and mean linear flow rates were assessed.Total organic carbon, chemical oxygen demand, total phosphorus, total nitrogen, and potassium among other parameters were analyzed during both treatments. The industrial swine slaughterhouse wastewater contained TOC 333 mg L–1, COD 1765 mg L–1, TP 13.55 mg L–1, TN 327 mg L–1, K 45 mg L–1, turbidity 102 NTU, color –absorbance 0.90 A.U. at 415 nm–, conductivity 1.9 mS cm–1, and pH 6.9. The highest TOC removal efficiency (72.7%), in semicontinuous process, was found at j = 25 mA cm-2 and ur = 0.64 cm s-1 with an energy consumption of 19.80 kW h m-3. Residual COD and TP concentrations met the international standard limits. Moreover, complete discoloration and disinfection were achieved. EDXRF, SEM, EDAX, XRD, and FTIR analyzes indicate pollutants were removed by adsorption on aluminum/iron hydroxides/oxyhydroxides.

Effect of ore quality on non‐aqueous oil sand extraction performance

AbstractCurrent commercial aqueous based extraction processes are energy and greenhouse gas (GHG) intensive and require large tailings ponds. Non‐aqueous extraction (NAE) of bitumen from mineable oil sands is an alternative that eliminates tailings ponds with potentially lower energy requirements and GHG emissions. The economics of the NAE process depend partly on the impact of ore quality on bitumen recovery and product quality (low water and solids content). It has been claimed that NAE performance is insensitive to the quality (bitumen content) of the oil sand ores. However, the available data are ambiguous because different extraction methods and solvents were used in different studies and, in many cases, a limited range of ore qualities was examined. In this study, bitumen was extracted from eight ores of different quality with cyclohexane using a multistage method equivalent to a countercurrent process with a solvent/ore ratio of 0.67 w/w. The bitumen recovery and the water and solids content of the product bitumen were determined for each ore. It was found that bitumen recovery correlated negatively to clay content of the ore. The loss of recovery was attributed to bitumen adsorption on clays. The product quality was insensitive to the ore quality and instead depended on the density of the fluid medium, as expected with a centrifuge‐based separation method. The recovery and product quality from the NAE method were similar to those from aqueous extractions.

Evaluation of polymethyl-methacrylate and acetal denture base resins processed by two different techniques before and after nano-chlorohexidine surface treatment

BackgroundFlexible denture base polymers have gained popularity in modern dentistry however, their biofilm formation tendency, adversely affecting the oral tissue heath, remains a concern. Consequently, this study aimed to evaluate surface roughness and biofilm formation tendency of two types of denture base resins manufactured with two techniques before and after surface coating with chlorohexidine (CHX) NPs.Materials and methodsAcetal (AC) and Polymethyl-methacrylate (PMMA) resins manufactured by conventional and CAD/CAM methods were shaped into disk (10 X 10 X 1 mm). They were dipped for 8 h and 24 h in colloidal suspension prepared by mixing aqueous solution of CHX digluconate and hexa-metaphosphate (0.01 M). Surface roughness, optical density (OD) of microbial growth media and biofilm formation tendency were evaluated directly after coating. Elutes concentrations of released CHX were evaluated for 19 days using spectrophotometer. Three-way ANOVA and Tukey’s post-hoc statistical analysis were used to assess the outcomes.ResultsAC CAD/CAM groups showed statistically significant higher roughness before and after coating (54.703 ± 4.32 and 77.58 ± 6.07 nm, respectively). All groups showed significant reduction in OD and biofilm formation tendency after surface coating even after 19 days of CHX NPs release.ConclusionsBiofilm formation tendency was highly relevant to surface roughness of tested resins before coating. After CHX NPs coating all tested groups showed significant impact on microbial growth and reduction in biofilm formation tendency with no relation to surface roughness. Significant antimicrobial effect remained even after 19 days of NPs release and specimens storage.

Highly Reliable 3D Channel Memory and Its Application in a Neuromorphic Sensory System for Hand Gesture Recognition.

Brain-inspired neuromorphic computing systems, based on a crossbar array of two-terminal multilevel resistive random-access memory (RRAM), have attracted attention as promising technologies for processing large amounts of unstructured data. However, the low reliability and inferior conductance tunability of RRAM, caused by uncontrollable metal filament formation in the uneven switching medium, result in lower accuracy compared to the software neural network (SW-NN). In this work, we present a highly reliable CoOx-based multilevel RRAM with an optimized crystal size and density in the switching medium, providing a three-dimensional (3D) grain boundary (GB) network. This design enhances the reliability of the RRAM by improving the cycle-to-cycle endurance and device-to-device stability of the I-V characteristics with minimal variation. Furthermore, the designed 3D GB-channel RRAM (3D GB-RRAM) exhibits excellent conductance tunability, demonstrating high symmetricity (624), low nonlinearity (βLTP/βLTD ∼ 0.20/0.39), and a large dynamic range (Gmax/Gmin ∼ 31.1). The cyclic stability of long-term potentiation and depression also exceeds 100 cycles (105 voltage pulses), and the relative standard deviation of Gmax/Gmin is only 2.9%. Leveraging these superior reliability and performance attributes, we propose a neuromorphic sensory system for finger motion tracking and hand gesture recognition as a potential elemental technology for the metaverse. This system consists of a stretchable double-layered photoacoustic strain sensor and a crossbar array neural network. We perform training and recognition tasks on ultrasonic patterns associated with finger motion and hand gestures, attaining a recognition accuracy of 97.9% and 97.4%, comparable to that of SW-NN (99.8% and 98.7%).

НЕКОТОРЫЕ АСПЕКТЫ СОЗДАНИЯ ОЗДОРОВЛЕНЫХ КОЛЛЕКЦИЙ ВИНОГРАДА АБОРИГЕННЫХ ДОНСКИХ СОРТОВ В КУЛЬТУРЕ IN VITRO

The article discusses some aspects of improving the elements of technology for creating of healthy collection of indigenous grape varieties in vitro. To recover from phytoplasma infec-tion, a chemotherapy method using the antibi-otic Cefotaxime has been developed. At high concentrations of the antibiotic, intoxication of plants and deterioration in their quality charac-teristics were noted. Plants of Makhrovatchik variety showed an improvement in survival rate at antibiotic concentrations of 100 and 200 mg/l: 64.3 and 60.7%, respectively. For long-term cultivation without replantings, the effectiveness of slowing down growth process-es by increasing the density of the nutrient me-dium was studied. The study was carried out on the varieties Makhrovatchik, Tsimlyansky Sergienko. Studied concentrations of agar-agar were (6, 8, 10, 12, 13 and 15 g/l). A decrease in the rate of growth processes was noted in all studied varieties, but the rate of the decrease was different.

Current Density in a Nonlinear Medium of Carbon Nanotubes under the Action of Diffraction-Free Laser Pulses

Current Density in a Nonlinear Medium of Carbon Nanotubes under the Action of Diffraction-Free Laser Pulses