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Background: Radiochromic film (RCF) dosimeters with their high spatial resolution and tissue equivalent properties are conveniently used for two‐dimensional and small‐field dosimetry. OC‐1 is a new model of RCF dosimeter that was commercially introduced recently. Due to its novelty there is a need to characterize its response in various radiation beam types. Purpose: To study the response of OC‐1 RCFs to megavoltage clinical x‐ray, electron, and proton beams, as well as kilovoltage x‐ray beams used in a small animal research irradiator. Materials and methods: OC‐1 RCFs were cut into ∼4 × 4 cm2 pieces. RCF samples were irradiated at various dose levels in the range 0.5–120 Gy using different modalities; a small animal radiation research platform (SARRP) (220 kVp), a medical linear accelerator (6 MV, 10 MV, 15 MV, 6 MV FFF, 10 MV FFF photon beams, as well as 6 and 20 MeV electron beams), and a gantry‐mounted proton therapy synchrocyclotron. In order to study any dependency on the fractionation scheme, same dose was delivered at several fractions to a set of films. Different dose rates in the range 200–600 MU/min were delivered to a set of films to investigate any dose rate dependency. The films were scanned pre‐irradiation and at 48 h post‐irradiation using a flatbed scanner. The net optical density (OD) was measured for red, green, and blue color channel for each film. The orientation dependency was studied by scanning the films at eight different orientations. In order to study the temporal evolution of the response of the films, film samples were irradiated at 10 and 50 Gy using 6 MV photon beams and were scanned upon irradiation at certain time intervals up to 3 months. The spectral response of the films were studied over the visible range using a spectrometer. Results: For megavoltage photon, electron, and plateau region of the proton beams, we did not observe a significant dependency on the beam quality, dose rate, and fractionation scheme. At the kV beam, an unusual over‐response was observed in the films' net OD. An orientation dependency in the response of the films with a sinusoidal trend was observed. The response of the films increased with time following a double or triple exponential trend. The spectral absorption peaks were blue‐shifted with dose. Conclusion: OC‐1 RCFs were found to be reliable dosimeters with no significant energy dependency in MV range for photon and electron beams including the FFF beams. They over‐respond when irradiated by kV x‐ray beams compared to MV x‐ray beams. Caution must be exercised to maintain the orientation of the films when scanning. Due to the temporal growth in the net OD of the films, same post‐irradiation time interval must be used for scanning the calibration and test films. [ABSTRACT FROM AUTHOR]

The functional group distribution and skin–core structure of polyacrylonitrile (PAN) pre-oxidized fibers have been evaluated by solid-state 13C-NMR, electron probe micro-analysis, element analysis, nano-infrared spectroscopy atomic force microscopy, and optical microscopy. The pre-oxidized fibers exhibited a skin–core structure with high optical density (OD) values in the skin and low OD values in the core. As the heat treatment temperature was increased, the OD of the pre-oxidized fibers increased, which is because of the formation of C = O, C = N, C = C, and their conjugated structures of C = N with C = C. The difference in the OD values between the pre-oxidized fiber skin and core became increasingly apparent as the heat treatment temperature increased, with the OD difference increasing from 0.045 at 220 °C to 0.085 at 260 °C. The OD difference is closely related to the oxygen element and C = O functional groups in the fiber. The contents of the oxygen element and C = O in the pre-oxidized fiber skin were higher than those in the pre-oxidized fiber core. At a heat treatment temperature of 260 °C, the relative content of C = O in the skin was 0.454, whereas that in the core was 0.313, which was consistent with the trend of the OD value change. In comparison, C = C and C = N formed during pre-oxidation were not substantially distributed in the radial direction of the fibers. The radial inhomogeneity of the pre-oxidized fiber was mainly affected by the radial difference of the carbonyl content. [ABSTRACT FROM AUTHOR]

This work proposes an original method that reveals the transformation dynamics of nanosized Bi films into semiconductor films of bismuth oxide (Bi2O3) and the factors affecting the low‐energy cold plasma on the electro‐optical properties of Bi2O3. In the plasma microreactor with a photosensitive GaAs:Cr electrode, the transformed Bi films 400–1100 nm thick are analyzed by X‐ray diffraction to determine the crystal structure of Bi2O3 and by an electron probe microanalyzer to explore the evolution of the composition. The morphological properties of the Bi films exposed to electron–ion flow are examined by processing the scanning electron microscope images. It is found that as a result of the combined effect of photoactive illumination, charged particles, and active plasma components: 1) an absorption spectrum of a new substance is formed in the range λ = 330–1100 nm; 2) the optical width of the bandgap of the resulting substance is Eg ≈ 3 eV, which satisfactorily coincides with the width of the bandgap of Bi2O3; and 3) to overcome the potential barrier and formation of semiconducting Bi2O3 film energy is required, which is provided by the combined kinetic energy of electrons and negatively charged oxygen ions bombarding on the Bi film. [ABSTRACT FROM AUTHOR]

The peculiarities of the decoration of gravure imprints on cardboard using fluorescent inks are considered. The influence of the number of fluorescent impurities added to gravure printing ink on the optical indicators of printed image quality, particularly optical density, and gloss, is investigated. Increasing the number of fluorescent impurities added to the ink from 10 to 30% helps to increase the gloss on imprints from 2 to 15 units. Conducted thermogravimetric studies show the resistance of fluorescent imprints to the influence of temperatures during drying in the printing process. The topography of the surface of the substrates and its influence on the quality of imprints is studied. Conducted electron microscopic studies of imprints obtained with inks with different amounts of fluorescent impurities show their uniform distribution on the surface of the substrate. Studies of the fluorescence spectra of the ink and the imprints formed by it confirm the phenomenon of an increase in the intensity of the glow of printed images. The studies confirm the well-known influence of substrate roughness on the smoothness of gravure imprints. It is established that the absence of significant macro irregularities on the surface of Koppargloss FBB cardboard is due to the presence of two coating layers. Analysis of the surface profiles of FBB cardboard shows that its roughness parameter (Ra = 0.424 μm) is three times smaller compared to Incada Silk C GC1 cardboard (the roughness parameter Ra = 1.28 μm), with a single-layer coating. Such a pattern is also preserved on the imprints, which is reflected in their quality accordingly. Studies show that for imprints on GC1 cardboard, the average ΔE value is 2.23, for imprints on FBB cardboard, the average ΔE value is 3.71, which is due to the presence of double coating. The factors that can influence the process of fluorescence of printed images are outlined. The technological characteristics of inks for gravure printing on packaging are described. [ABSTRACT FROM AUTHOR]

The peculiarities of the decoration of gravure imprints on cardboard using fluorescent inks are considered. The influence of the number of fluorescent impurities added to gravure printing ink on the optical indicators of printed image quality, particularly optical density, and gloss, is investigated. Increasing the number of fluorescent impurities added to the ink from 10 to 30% helps to increase the gloss on imprints from 2 to 15 units. Conducted thermogravimetric studies show the resistance of fluorescent imprints to the influence of temperatures during drying in the printing process. The topography of the surface of the substrates and its influence on the quality of imprints is studied. Conducted electron microscopic studies of imprints obtained with inks with different amounts of fluorescent impurities show their uniform distribution on the surface of the substrate. Studies of the fluorescence spectra of the ink and the imprints formed by it confirm the phenomenon of an increase in the intensity of the glow of printed images. The studies confirm the well-known influence of substrate roughness on the smoothness of gravure imprints. It is established that the absence of significant macro irregularities on the surface of Koppargloss FBB cardboard is due to the presence of two coating layers. Analysis of the surface profiles of FBB cardboard shows that its roughness parameter (Ra = 0.424 μm) is three times smaller compared to Incada Silk С GC1 cardboard (the roughness parameter Ra = 1.28 μm), with a single-layer coating. Such a pattern is also preserved on the imprints, which is reflected in their quality accordingly. Studies show that for imprints on GC1 cardboard, the average ΔE value is 2.23, for imprints on FBB cardboard, the average ΔE value is 3.71, which is due to the presence of double coating. The factors that can influence the process of fluorescence of printed images are outlined. The technological characteristics of inks for gravure printing on packaging are described.

One of the factors that influence shrimp cultivation is the presence of algae. Precise knowing algae content in the pond is essential for effective management. Most research in the field of algae species carried out by researchers were observing Chlorella Sp. more than the other algae species, with a particular emphasis on substance concentrations. This study proposed non-invasive techniques for quantifying algae abundance, utilizing optical density (OD) and image processing (IP) methods. Three different algae species are frequently found in Indonesia i.e., Chlorella Sp., Thalassiosira Sp., and Skeletonema Sp. are used as sample. Those samples are cultured and prepared in a certain volume with a certain quantity. For experimental and observation purposes, those samples are then diluted into water based on percentage value. The experimental results provided RGB values, which were then used to establish polynomial equations. To verify these equations, two approaches were employed: synthetic image analysis and evaluation using additional data. The mean average error (MAE) was found to be 3.467 for IP method and 3.513 for OD method. It shows that IP method give better result compared to OD method in this study. However, it is very possible that the two methods will complement each other. [ABSTRACT FROM AUTHOR]

The hyphal surface of cells of filamentous fungi is covered with cell wall, which is mainly composed of polysaccharides. Since the cell wall is the first structure to come in contact with the infection host, the environment, and the fungus itself, the elucidation of the cell wall structure and biogenesis is essential for understanding fungal ecology. Among filamentous fungi, the genus Aspergillus is an important group in the industrial, food, and medical fields. It is known that Aspergillus species form hyphal pellets in shake liquid culture. The authors previously found the role of a-1,3-glucan in hyphal aggregation in Aspergillus species. In addition, extracellular polysaccharide galactosaminogalactan contributed to hyphal aggregation as well, and dual disruption of biosynthesis genes of a-1,3-glucan and galactosaminogalactan resulted in complete hyphal dispersion in shake liquid culture. The characteristic of mycelia to form pellets under liquid culture conditions was the main reason why the growth measurement methods used for unicellular organisms could not be applied. We reported that hyphal growth of the dual disruption mutant could be measured by optical density. A real-time plate reader could be used to determine the growth curve of the mycelial growth of the dual disruption mutant. This measurement approach not only provides basic microbiological insights in filamentous fungi, but also has the potential to be applied to high-throughput screening of anti-Aspergillus drugs. [ABSTRACT FROM AUTHOR]

Purpose: The Beer–Lambert law suggests that visual pigment optical density (OD) should be linearly related to the length of photoreceptor outer segments (POSs). Mammalian studies indicate that visual pigment concentration increases with POS length, but the nature of this relationship may vary due to factors such as visual pigment packing density or retinal eccentricity, and may not necessarily be linearly related. The purpose of this study was to establish the relationship between OD and POS length in humans. Methods: Spectral domain optical coherence tomography (OCT) was used to image POS, and imaging retinal densitometry (IRD) was used to measure OD at corresponding locations in 19 healthy participants (age range 25–82 years). POS length and OD measurements were extracted from OCT and IRD images at 23 discrete locations spanning the central 9° of the retina. The averaged data from all participants were fitted with models based on the Beer–Lambert law to establish the relationship between OD and POS length. Results: Visual pigment OD increased monotonically with POS length, but the relationship was non‐linear, and a straight‐line fit, based on a simple interpretation of the Beer–Lambert law, provided a poor description. A model allowing for different rod and cone visual pigment concentrations provided a superior fit. Specifically, the data were well described by a model where the molar concentration of visual pigment in cones and rods were 3.8 × 10−3 mol/L and 1.8 × 10−3mol/L, respectively. Conclusions: In accordance with the Beer–Lambert law, the results indicate that OD increases monotonically with POS length in humans, but the precise relationship is dependent on photoreceptor type. These results suggest that visual pigment concentration in rods is only about 48% of that found in cones. This may be due to the ubiquitous nature of artificial light that works to reduce the concentration of rhodopsin in rod photoreceptors. [ABSTRACT FROM AUTHOR]

The physiological aging process is well known for functional decline in visual abilities. Among the components of the visual system, the dorsal lateral geniculate nucleus (DLG) and superior colliculus (SC) provide a good model for aging investigations, as these structures constitute the main visual pathways for retinal inputs reaching the visual cortex. However, there are limited data available on quantitative morphological and neurochemical aspects in DLG and SC across lifespan. Here, we used optical density to determine immunoexpression of glial fibrillary acidic protein (GFAP) and design‐based stereological probes to estimate the neuronal number, total volume, and layer volume of the DLG and SC in marmosets (Callithrix jacchus), ranging from 36 to 143 months of age. Our results revealed an age‐related increase in total volume and layer volume of the DLG, with an overall stability in SC volume. Furthermore, a stable neuronal number was demonstrated in DLG and superficial layers of SC (SCv). A decrease in GFAP immunoexpression was observed in both visual centers. The results indicate region‐specific variability in volumetric parameter, possibly attributed to structural plastic events in response to inflammation and compensatory mechanisms at the cellular and subcellular level. Additionally, the DLG and SCv seem to be less vulnerable to aging effects in terms of neuronal number. The neuropeptidergic data suggest that reduced GFAP expression may reflect morphological atrophy in the astroglial cells. This study contributes to updating the current understanding of aging effects in the visual system and stablishes a crucial foundation for future research on visual perception throughout the aging process. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the use of EBT3 film, specifically the active layer, for monitoring low-energy ion beams. The film's wettability was enhanced, and its surface free energy increased by 200% after irradiation, as determined by the contact angle technique. SEM analysis showed that the surface of the film became rougher, with a needle-like structure, and increased from 80 nm for the pristine sample to 116 nm for the sample exposed to the highest fluence. XRD analysis revealed an increase in crystallite dimension and a decrease in crystallinity. ATR-FTIR analysis demonstrated that the modified film is sensitive to low-energy ion beams, with certain bands showing significant changes that can be controlled by adjusting the ion fluence. These changes affect the color properties of the EBT3 film, which can be used to monitor the ion beam. The visible spectrum exhibited two distinct colors: blue at 648 nm and red at 596 nm. The blue-to-red ratio was calibrated based on the applied fluence using a polynomial function. The film's net optical density was separately analyzed for each color, with the blue color being dominant. However, the red color accurately calibrated the film's response to low-energy ion beams with a usable fluence of up to 1 × 1017 ion/cm2. In conclusion, low-energy ion beams caused significant structural and optical changes in the active layer of EBT3 films, which can be controlled and customized for monitoring ion beams. [ABSTRACT FROM AUTHOR]

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Chlorella vulgaris is of great importance in numerous exploratory or industrial applications (e.g., medicals, food, and feed additives). Rapid quantification of algal biomass is crucial in photobioreactors for the optimization of nutrient management and the estimation of production. The main goal of this study is to provide a simple, rapid, and not-resource-intensive estimation method for determining the algal density of C. vulgaris according to the measured parameters using UV–Vis spectrophotometry. Comparative assessment measurements were conducted with seven different methods (e.g., filtration, evaporation, chlorophyll a extraction, and detection of optical density and fluorescence) to determine algal biomass. By analyzing the entire spectra of diluted algae samples, optimal wavelengths were determined through a stepwise series of linear regression analyses by a novel correlation scanning method, facilitating accurate parameter estimation. Nonlinear formulas for spectrometry-based estimation processes were derived for each parameter. As a result, a general formula for biomass concentration estimation was developed, with recommendations for suitable measuring devices based on algae concentration levels. New values for magnesium content and the average single-cell weight of C. vulgaris were established, in addition to the development of a rapid, semiautomated cell counting method, improving efficiency and accuracy in algae quantification for cultivation and biotechnology applications. [ABSTRACT FROM AUTHOR]

In the current investigation, WO3 thin films are prepared via simple hydrothermal method at different pH values (1, 7 and 11). In this study, XRD, SEM, FTIR, UV–visible, and electrochemical techniques were used to study pH effects on the preparation of WO3 and their structural, morphological, and electrochromic variations. The XRD analysis revealed that the pH of the precursor solution significantly influences crystallinity, with acidic conditions favouring high crystallinity and efficient electrochromic (EC) performance, while more alkaline conditions result in reduced crystallinity and amorphous film formation. The SEM analysis demonstrates that pH significantly influences the morphology of WO3 films. FTIR spectroscopy exhibited characteristic peaks associated with WO3, affirming the successful synthesis of WO3 thin films. The electrochemical investigations demonstrated that WO3 films prepared at a pH of 1 exhibited exceptional EC activity, characterized by the highest optical modulation density of 0.3 and a colouration efficiency (CE) of approximately 122.2 cm2/C at 633 nm. These findings underscore the promising potential of pH-controlled hydrothermal method for tailoring the electrochromic behavior of WO3 thin films, with implications in energy efficient smart windows.

Haematococcus pluvialis synthesizes and accumulates astaxanthins, while Spirulina (Arthrospira) platensis produces phycocyanins. The ornamental shrimp Neocaridina davidi is commercially important for its variety and intensity of coloration. We evaluate the effect on the coloration of N. davidi by consuming H. pluvialis and S. platensis as a food supplement to preserve their nutritional quality. H. pluvialis was subjected to stress to obtain aplanospores with astaxanthin. Live microalgae were included in gelled spheres to provide them as a supplement to three-day-old N. davidi juveniles with different phenotypes: wild (NdW), red (NdR), and blue (NdB). The experiment involved the commercial food supply and spheres with or without microalgae for 31 days. Chromatophores present in the uropod of each phenotype were examined, their number and expansion estimated, and the area covered by optical density (OD). Results show that H. pluvialis reached a greater astaxanthin accumulation on day 30. The coloration of the NdR and NdB phenotypes improved by consuming microalgae, increasing the OD in the uropod. NdB phenotype showed better coloration when consuming S. platensis (56.2%), while the NdR phenotype was more favored when consuming H. pluvialis (74.2%). The chromatophores expanded their area by doubling in the NdR and NdB phenotypes, where H. pluvialis increased its intensity four times in NdR. The number of chromatophores was significant only in NdR with S. platensis. In conclusion, gelling is a viable method to preserve the nutritional quality of live microalgae and transfer bioactive compounds that improve the coloration of N. davidi. [ABSTRACT FROM AUTHOR]

Biofilm polymicrobial infections have gained international attention, especially cases involving fungi and bacteria. Such infections require patients to undergo costly, extended hospital stays and have caused a considerable amount of morbidity and mortality. Polymicrobial biofilms also have greater mortality rates than monomicrobial biofilms. This study aims to evaluate the overall biomass of biofilms produced by Candida albicans interacting with two Gram-positive bacteria: E. faecalis and S. aureus. Tryptic Soy Broth (TSB) medium were used for the bacterial and fungal suspensions. Three 96-well microplates were used for the biofilm cultivation. The microplates were then incubated for 24, 48, and 72 hours at 37˚C. Next, after conducting the Crystal Violet test, the biofilms’ Optical Density (OD) values were measured by an ELISA reader. The mixed species treatment of Candida albicans with S. aureus for 72 hours had the highest average OD value (OD ± SD = 0.903 ± 0.050), while the mixed species treatment of Candida albicans with E. faecalis for 24 hours had the lowest average OD value (OD ± SD = 0.240 ± 0.032). In conclusion, the parameters observed in this study revealed that biofilms could be formed well by polymicrobial interactions between Candida albicans and two Gram-positive bacteria: S. aureus and E. faecalis. [ABSTRACT FROM AUTHOR]

This paper presents a novel low-cost phosphate glass preparation by using the melt quenching technique. It was investigated for use in diagnostic protective applications. The range of UV-VIS wavelength is used to estimate the optical energy gap. The MAC denotes the mass attenuation coefficients of the present glass were computed at low photon energies between 15 and 200 KeV using the MIKE program. The manufactured glasses parameters viz; the mean free path, half value layer, tenth value layer, effective atomic number, effective electron density, and linear attenuation coefficient denotes as follows; MFP, HVL, TVL, Zeff, Neff and LAC were determined. Furthermore, the molar volume, oxygen molar volume, and optical packing density of fabricated glass were assessed. The third-order susceptibility (χ(3) and non-linear refractive index of the present glass were determined. From previous results, it can be concluded that the glass has unique attenuation characteristics, therefore, can be used for radiation protection at low energy 15 to 200 KeV. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite materials with catalytic activity were designed via modification of MF-4SK ion-exchange membranes with Au and Ag nanoparticles obtained according to various synthetic methods in reverse micellar solutions. A sufficient transparency of the films allowed us to detect nanoparticles in the films using UV–Vis spectrophotometry, monitoring changes in the content of metal nanoparticles in the reverse micellar solution. A different mechanism of interaction of Au and Ag nanoparticles obtained by the same synthetic method with the MF-4SK film upon their contact with its surface was discovered, the destruction of nanoparticles was observed, and the influence of mechanism of primary acts in the formation of metal nanoparticles in reverse micellar solutions on their adsorption properties was confirmed. The highest concentration of gold nanoparticles was found in films immersed in reverse micellar solutions at the time of their exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

The distribution of boron in biological samples coming from BNCT protocols can be determined by the analysis of autoradiographic images formed by nuclear tracks on polymeric detectors. The tissue section is first explored to delimit regions of interest (ROIs), and then it is removed in order to reveal nuclear tracks through an etching process. A quantitative autoradiographic technique was developed to measure the boron concentration in the sample by counting the nuclear tracks on the detector. However, under certain circumstances, rapid measurements of boron distribution are required. For that purpose, a methodology was developed, allowing a rapid and easy determination of boron concentration and distribution in a tissue section by measuring grey levels in the corresponding high fluence autoradiographic image (HFA). The grey levels are then converted to optical density values which are then correlated with boron concentration values. In order to validate the technique, consecutive sections of several tissue samples were analyzed by the conventional counting method and by HFA. The image analysis and boron concentration estimation can be carried out in under 15 min, and relative differences between zones can be easily determined. [ABSTRACT FROM AUTHOR]

In this work, three organotin (IV) derivatives namely dibutyltin(IV) di-2-hydroxybenzoate (DBT2-HBz) (2), dibutyltin(IV) di-3-hydroxybenzoate (DBT3-HBz) (3) and dibutyltin(IV) di-4-hydroxybenzoate (DBT4-HBz)) (4) were synthesized and tested as disinfectant against pathogenic bacteria, Staphylococcus aureus. Compounds 2–4 were prepared by reacting dibutyltin(IV) oxide (DBTO) (1) with 2-hydroxybenzoic acid (2-HHBz), 3-hydroxybenzoic acid (3-HHBz) and 4-hydroxybenzoic acid (4-HHBz). The synthesized compounds were characterized by spectroscopic techniques including UV–Vis, FT-IR, 1H NMR, and 13C NMR, and micro-elemental analyzer. The optical density (OD) of compounds was measured by UV–Vis at 600 nm, which showed good bioactivity against the S. aureus. The data obtained indicated that compound 4 has higher bioactivity than compound 2 and 3, and the positive control using a commercial disinfectant containing 5 % benzalkonium chloride. The optimum bioactivity of compound 4 was observed at a concentration of 5 × 10−4 M with a contact time of 10 min, as shown by the decrease in absorbance from 0.6092 to 0.4005. Compound 2 was optimal at a concentration of 5 × 10−4 M with a contact time of 10 min, and the absorbance decreased from 0.6092 to 0.4416. Compound 3 and positive control showed a smaller decrease in absorbance compared to compound 4 and 2. Overall, the results obtained indicated that the compounds synthesized have promising potential as disinfectant against pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Present study evaluated the susceptibility of essential nutrients available in thermoelectric coal fly ash (CFA) for the cultivation of screened microalgae maintained in demineralized water − CFA (DMW + CFA) as culture medium. Different concentration of CFA culture medium was prepared from 0.5 to 4.0 g/L of CFA, but the low nitrate and phosphate content in culture medium was not plausible for growth of cells; therefore, additional NaNO3 and KH2PO4 were added. Culture mediums were inoculated with characterized microalgae chlorococcum sp. and placed in ambient dark/light period for growth study which was measured with time by optical density. Max. OD @ 680 and @750 nm observed as 0.396 ± 0.073 and 0.306 ± 0.072 for 0.5 g/L culture medium, respectively. Max. biomass yield was 562.21 ± 95.54 mg/L for 0.5 g/L culture medium; however, yield was 40.00% low as compared to BG-11 culture. Max. sp. growth rate observed was 0.253 ± 0.007 d−1 for 0.5 g/L. The max total lipid was 139.0 ± 7.5 mg/L for 1.0 g/L culture, which was comparable with BG-11. NO3-N and PO4-P concentration reduced > 90% whereas Na+, K+ and Ca+ content was reduced > 75.00–90.00%. ORP was also intriguingly measured for oxidative state of culture medium during growth phase and found to be maintained between + 350 and + 25 mV. Max. total chlorophyll analysed was 4.64 ± 0.56 µg/ml. The results support that CFA may be used as culture medium for chlorococcum sp. for biomass and lipid production and subsequent nutrient recovery from CFA. [ABSTRACT FROM AUTHOR]

Highlights: 1. It is essential to conduct research on SARS-CoV-2 for the purpose of acquiring further understanding, especially concerning the production of antibodies examined using antibody titer blood tests. 2. Although the relationship between the examined variables is not significant, this study offers valuable information on blood test results after the COVID-19 vaccination, which can serve as scientific evidence for further research. Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus that infects the respiratory system by attacking the mucous and epithelial cells. This infection commonly leads to an increase in lymphocyte count as an immune response to invading pathogens. Moreover, antibodies bind and inactivate foreign substances to destroy pathogens and inhibit their replication. These mechanisms prompt the objective of this study, which was to define the relationship between lymphocyte count and SARS-CoV-2 antibody level. This analytical observational study used a cross-sectional approach with quantitative analysis methods and purposive sampling. Healthy donors who had received coronavirus disease (COVID-19) vaccines provided the samples for this study. A total of 30 blood samples were collected from the Blood Transfusion Center of the Indonesian Red Cross Surabaya Area. This study was conducted in May 2022 at two distinct locations. The examination of lymphocytes was carried out using the flow cytometry method in the Hematology Laboratory, Department of Medical Laboratory Technology, Politeknik Kesehatan Kemenkes Surabaya, Surabaya, Indonesia. In addition, the antibody titer test using the enzyme-linked immunosorbent assay (ELISA) method was performed in the Immunoserology Laboratory of the Surabaya Health Laboratory Center, Surabaya, Indonesia. The analysis revealed an average lymphocyte concentration of 2.2633 x 103/µl and an average antibody level of 0.2197 according to the optical density (OD) ratio. The data analysis was performed using Spearman's rank correlation statistical test (p

Introduction: After more than 100 years of generating monoculture batch culture growth curves, microbial ecologists and evolutionary biologists still lack a reference method for inferring growth rates. Our work highlights the challenges of estimating the growth rate from growth curve data. It shows that inaccurate estimates of growth rates significantly impact the estimated relative fitness, a principal quantity in evolution and ecology. Methods and results: First, we conducted a literature review and found which methods are currently used to estimate growth rates. These methods differ in the meaning of the estimated growth rate parameter. Mechanistic models estimate the intrinsic growth rate μ, whereas phenomenological methods -- both modelbased and model-free -- estimate the maximum per capita growth rate μ Using math and simulations, we show the conditions in which μmax is not a good estimator of μ. Then, we demonstrate that inaccurate absolute estimates of μ are not overcome by calculating relative values. Importantly, we find that poor approximations for μ sometimes lead to wrongly classifying a beneficial mutant as deleterious. Finally, we re-analyzed four published data sets, using most of the methods found in our literature review. We detected no single best-fitting model across all experiments within a data set and found that the Gompertz models, which were among the most commonly used, were often among the worst-fitting. Discussion: Our study suggests how experimenters can improve their growth rate and associated relative fitness estimates and highlights a neglected but fundamental problem for nearly everyone who studies microbial populations in the lab. [ABSTRACT FROM AUTHOR]

Bacillus anthracis is an etiological agent of anthrax, a severe zoonotic disease that can be transmitted to people and cause high mortalities. Bacteriophages and their lytic enzymes, endolysins, have potential therapeutic value in treating infections caused by this bacterium as alternatives or complements to antibiotic therapy. They can also be used to identify and detect B. anthracis. Endolysins of two B. anthracis Wbetavirus phages, J5a and F16Ba which were described by us recently, differ significantly from the best-known B. anthracis phage endolysin PlyG from Wbetavirus genus bacteriophage Gamma and a few other Wbetavirus genus phages. They are larger than PlyG (351 vs. 233 amino acid residues), contain a signal peptide at their N-termini, and, by prediction, have a different fold of cell binding domain suggesting different structural basis of cell epitope recognition. We purified in a soluble form the modified versions of these endolysins, designated by us LysJ and LysF, respectively, and depleted of signal peptides. Both modified endolysins could lyse the B. anthracis cell wall in zymogram assays. Their activity against the living cells of B. anthracis and other species of Bacillus genus was tested by spotting on the layers of bacteria in soft agar and by assessing the reduction of optical density of bacterial suspensions. Both methods proved the effectiveness of LysJ and LysF in killing the anthrax bacilli, although the results obtained by each method differed. Additionally, the lytic efficiency of both proteins was different, which apparently correlates with differences in their amino acid sequence. Key points: • LysJ and LysF are B. anthracis-targeting lysins differing from lysins studied so far • LysJ and LysF could be overproduced in E. coli in soluble and active forms • LysJ and LysF are active in killing cells of B. anthracis virulent strains [ABSTRACT FROM AUTHOR]

Purpose: To develop a method to measure the macular pigment optical density (MPOD) using scanning laser ophthalmoscopic images in young adults and children. Study design: Cross-sectional study. Methods: Blue light reflectance fundus images of 32 healthy subjects were used. A profile of the linear reflectance changes across the center of the fovea on a grayscale fundus image was generated. The ratio of the macula-to-periphery reflection was designated as the peak value of the MPOD (MPOD[FR]) based on established fundamentals. In the MPOD profile, the basal width of the pixels at MPOD < 0 (wMP) and width at one-half value of the MPOD[FR] (wMP0.5) were determined. The MOPD at eccentricity of 0.5° was measured by heterochromatic flicker photometry (MPOD[HFP]), and the correlation between the MPOD[FR] and MPOD[HFP] was evaluated. Results: The MPOD[FR] ranged from 0.17 to 0.73 with a mean of 0.40 ± 0.13. The wMP ranged from 88 to 173 pixels with a mean of 121.7 ± 24.2 pixels, and the wMP0.5 ranged from 38 to 83 pixels with a mean of 54.1 ± 10.3 pixels. A significant correlation was found between the MPOD[FR] and MPOD[HFP] (r = 0.41, P = 0.02). Conclusions: This simplified method can provide accurate and reliable values of the MPOD comparable to heterochromatic flicker photometry. Obtaining the fundus images in this fast and easy way should be suitable for children thus enabling clinicians to determine the MPODs for children. [ABSTRACT FROM AUTHOR]

Data on the influence that grey heron (Ardea cinerea L., 1758) colonies have on the dynamics of tree ring parameters in pine plantations are presented. It is shown that the beginning of the stands colonisation by the grey heron can be quite accurately determined by analysing the dynamics of the annual tree rings parameters, especially the width of their late layer and the optical density of wood (the values of the former are lower in the control stand, and of the latter one are higher there). Grey heron colonies begin to appear in pine forests as early as 10–12 years old, when the height of the trees reaches 5–6 m, and the diameter of the trunk at a height of 1.3 m from the soil surface is only 7–8 cm. In the first 15–20 years, they have a positive influence on the annual growth of trees, especially on the width of the late layer of wood and the thickness of the cell walls, but then the picture changes to the opposite. The total residence time of heron colonies in one place is about 35–40 years, after which they move to new places due to the forest stands coming into disarray or even facing complete destruction. To reduce the likelihood of the appearance of grey heron colonies, which in many cases have a negative impact on the state of forest biogeocoenoses, it is necessary to stop creating pure pine forests near water bodies, giving preference to spruce, birch, poplar, or linden-oak plantations. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbons are a major concern due to their widespread distribution in the environment, and their harmful effects on humans. The use of biodegradation methods to clean soil that has been contaminated by spilt petroleum can be an effective remediation strategy. Therefore, in this study, the presence of indigenous microorganisms in soil contaminated with crude oil was investigated and their ability to degrade petroleum in vitro was studied. Three methods were used to detect crude oil and pure hydrocarbon degradation by bacterial and fungal isolates. Spectrophotometric method, 2,6-Dichlorophenol indophenol (DCPIP) method and hydrocarbon analysis was performed by GC–MS. Furthermore, PCR was carried out to detect the genes AlkB and PMO in the microbial communities. Seventeen bacterial isolates and 5 fungal isolates were recovered from 19 soil culture samples obtained from three different oil-contaminated sites at Taq-taq (TTOPCO) oil field and from a control site without oil contamination. The bacterial samples were identified culturally and morphologically, and the results were validated by genetic analysis. The results of this study revealed that the indigenous bacterial and fungal isolates had a high capacity to degrade crude oil and pure hydrocarbon fractions. Our results provide insight into the great abilities of Bacillus anthracis, Bacillus cereus, Achromobacter sp., Aspergillus lentulus and Rhizopus arrhizus to degrade crude oil and pure hydrocarbon fractions, and these data are supported by the presence of the PMO and AlkB genes in the isolated microorganisms. [ABSTRACT FROM AUTHOR]

The distribution of boron in biological samples coming from BNCT protocols can be determined by the analysis of autoradiographic images formed by nuclear tracks on polymeric detectors. The tissue section is first explored to delimit regions of interest (ROIs), and then it is removed in order to reveal nuclear tracks through an etching process. A quantitative autoradiographic technique was developed to measure the boron concentration in the sample by counting the nuclear tracks on the detector. However, under certain circumstances, rapid measurements of boron distribution are required. For that purpose, a methodology was developed, allowing a rapid and easy determination of boron concentration and distribution in a tissue section by measuring grey levels in the corresponding high fluence autoradiographic image (HFA). The grey levels are then converted to optical density values which are then correlated with boron concentration values. In order to validate the technique, consecutive sections of several tissue samples were analyzed by the conventional counting method and by HFA. The image analysis and boron concentration estimation can be carried out in under 15 min, and relative differences between zones can be easily determined.

We carried out studies on water deficiency of Sambucus nigra L. (black elderberry) plant leaves extract and fruit juice, relative turgidity, sucrose content in fruits, chlorophyll content in the leaves, as well as gas exchange rates in the leaves, in particular, the changes in the concentrations of oxygen released during photosynthesis by leaves and carbon dioxide released during leaf respiration depending on habitat conditions (altitude of the habitat, position of slopes, average annual precipitation). Taking into account the difference in climatic conditions and the generality of some indicators, Vanadzor (1326–1600 m above sea level) and Stepanavan (1400–1830 m above sea level) regions of Lori Province, "Dilijan" National Park, Lake Parz, and the forest areas adjacent to the city of Dilijan (1240–1612 m above sea level) in Tavush Province in Armenia were chosen as the research sites. The test samples were taken from eight different test sites in Lori and Tavush provinces. Tavush Province is more humid than Lori Province. The highest rate of water deficiency in the leaves of the studied plants was recorded in S. nigra f. laciniata (L.) Zabel., and the lowest in S. nigra in Vanadzor forest. It can be assumed that the index of water deficiency in the leaves may depend on the position of the slopes of the test sites and the value of the filtration coefficient of the soil types. On the north-facing slope at the height of 1341 m above sea level and on the south-facing slope at the height of 1830 m above sea level, the values of water deficiency of the leaves are almost the same. Such data allows us to assume that the degree of water deficiency in the leaves is also affected by the filtration coefficient of habitat soil types. In two points that have north-facing positions, the water deficiency of leaves at the height of 1341 m above sea level is 2.14 times more than at the height of 1328 m above sea level. At 1328 m above sea level the filtration coefficient is small and the plant absorbs a lot of water. Based on the data we received we obtained rankings of plants according to the different criteria of the experimental plants: water deficiency in leaves tissues, relative turgidity, the sum of chlorophylls in the leaves, the sucrose content in the fruits, percentage of oxygen released as a result of photosynthesis, percentage of carbon dioxide released as a result of respiration. We found a certain dependence between the indicators of the water regime and the height above sea level of the researched habitats. We also found out that the water regime is influenced by certain microclimatic conditions such as the position of the slopes, whether they are north or south facing, as well as the average annual precipitation. Knowing the physiological processes taking place in the vegetative and generative organs of the S. nigra plant is important from the point of view of evaluating the intensity of growth and development of the generative organs. We consider that the results of the study will be applicable in the process of plant selection based on the indicators of the physiological processes taking place in the plant organism.

An intravenous catheter is a medical device used to inject intravenous fluid into the body. This procedure can lead coagulase-negative staphylococci (CoNS) bacteria such as Staphylococcus epidermidis penetrates the skin and forms biofilm on the catheter. Biofilms bring serious problem such as antibiotic resistance, the long-term effects increase the length of staying in the hospital, cost, morbidity, and mortality. This research aimed to analyze the biofilm formation of S. epidermidis in several types of intravenous fluids based on time. This was a laboratory experimental research using microtiter plate assay method and crystal violet coloring. Three 96-well microplates were inoculated with S. epidermidis in ringer lactate, 10% dextrose, 5% dextrose, normal saline, and gelafusal, each plate was incubated at three different times of 24, 48, and 72 h respectively. The results show that the optical density (OD) values of all intravenous fluids with bacteria within 24 and 48 h of incubation time did not show significant differences compared to negative controls, while the 72 h treatments of 10% dextrose, 5% dextrose, and normal saline showed significant differences. This indicates that biofilms of S. epidermidis were not formed in intravenous fluids within 24 and 48 h of incubation time, however this bacterium started forming biofilm in 10% dextrose, 5% dextrose, and normal saline within 72 h of incubation time. In conclusion, the length of incubation time may influence biofilm formation. [ J Adv Biotechnol Exp Ther 2023; 6(2.000): 458-467]

An integral part of human healthy nutrition is intake of biologically active substances. Extraction is an important stage of isolation of different bioactive substances from plants and effectiveness of their extraction increases with the use of ultrasonic treatment. The aim of this research was to study an effect of different types of aqueous media and treatment methods on Cetraria islandica, including the use of principles of ultrasonic treatment and maceration methods (infusion). The experimental studies consisted in detecting an effect of the active acidity of the aqueous medium (solvent) and method of impact upon extraction on several physicochemical and rheological indicators. The experimental samples of extracts were examined by the following indicators: active acidity and redox potential detected by the ionometric technique; dynamic viscosity and the depth of output of polymeric forms of phenolic substances determined by measuring the optical density and transmission coefficient. Mathematical processing of data using the regression analysis was carried out. The results are presented as graphs, tables and regression equations. It has been established that transfer of substances from Cetraria islandica to its extracts had high results at pH = 7.0 and рН = 9.0 of the solvent. When obtaining extracts by the infusion method, the quantity of polymeric compounds in the transition process was 1.3 times higher than the quantity of monomeric forms of phenolic compounds. The highest value of the dynamic viscosity was revealed in the extract sample obtained by the infusion method in the alkaline medium. The extracts obtained can be used in food system modeling.

Water is considered as the working fluid of wet steam turbine units. The importance of a purposeful change in the thermophysical properties of water used for energy needs is indicated. A reagent-free method (transverse magnetic field of permanent magnets) of influence on water is proposed. Literature data on currently available papers dedicated to the study of water properties is presented. It is shown that the mechanisms of influence of external physical fields on the physicochemical and thermophysical properties of water have not been elucidated as of now. It is emphasized that the properties of distilled water during exposure and after exposure to physical fields are even less studied. The currently existing contradictions between theoretical ideas about the properties of water and experimental results are considered. It was found that currently there are no correct methods and equipment capable of indicating changes in water properties in real time. As a solution, the equipment and method of analyzing the optical density of distilled water is proposed. The shortcomings of most existing experimental works on the study of the influence of physical fields on the optical density of water are analyzed. The requirements for devices intended for measuring the optical density of distilled water are formulated. A stand was made and experimental work on the study of the dependence of the optical density of distilled water on the induction of a magnetic field that affects it was carried out. It is proved that the magnetic field affects the optical density of distilled water in the infrared range of wavelengths both in the direction of increase (4.1%) and in the direction of decrease (1.7%) depending on the induction of the magnetic field and the speed of water flow through the working section of magnetization device. A hypothesis explaining the obtained result is proposed

Makeup water constitutes a key component in the water management of microalgal cultivation systems. However, the effect of makeup water addition on microalgal growth remains largely unexplored. This study compared two deionized water addition intervals (1 day and 4 days) for their effect on the growth of Scenedesmus dimorphus (S. dimorphus hereafter) in 2000 mL Pyrex bottles under controlled conditions. Cell counts and dry algal biomass (DAB) were measured to characterize the microalgal growth rate. Water addition intervals impacted algal cell counts but had little effect on DAB. Adding makeup water every day resulted in a higher growth rate (8.80 ± 1.46 × 105 cells mL−1 day−1; p = 0.22, though) and an earlier occurrence of the peak cell count (day 9) than adding it every 4 days (6.95 ± 1.68 × 105 cells mL−1 day−1 and day 12, respectively). It is speculated that water loss over an extended period and the following makeup water addition posed stress on S. dimorphus. Surpassing the peak cell count, S. dimorphus continued to grow in DAB, resulting in an increased cell weight as a response to nutrient starvation. Optical density at 670 nm (OD670) was also measured. Its correlation with DAB was found to be affected by water addition intervals (R2 = 0.955 for 1 day and 0.794 for 4 days), possibly due to a water loss-induced change in chlorophyll a content. This study is expected to facilitate the makeup water management of photobioreactor and open pond cultivation systems.

Abstract Doxorubicin (DRB) is an anthracycline oncogenic drug extracted from cultures of Streptomyces peucetius var. caesius. It is frequently recommended as an anti-neoplastic agent for the treatment of diverse malignancies. It exerts its antineoplastic effect either via inhibiting the enzyme topoisomerase II and/or via intercalation to DNA or reactive oxygen species generation. In the present article, the direct, simple, one-pot, somewhat eco-safe, and non-extractive spectrophotometric system was executed to track doxorubicin, a chemotherapeutic remedy, in the presence of paclitaxel, a naturally occurring Taxan antineoplastic radical, through the greenness rated method. DRB’s optical density was studied in various mediums and solvents to develop the current approach. An acidic ethanolic solution was found to increase the optical density of the sample significantly. At 480 nm., the most remarkable optical density was obtained. Various experimental factors, including intrinsic media, solvent, pH, and stability time, were investigated and controlled. The current approach achieved linearity within the 0.6–40.0 µg mL-1 range, accompanied by a limit of both detection and quantification (LOD and LOQ) of 0.18 and 0.55 µg mL-1, correspondingly. The approach was validated under the ICH guidelines (Quality Guidelines). The system’s greenness and enhancement degree were estimated.

During the strategic military operations, the deployment of objects viz. tanks, rescue shelters, bunkers etc. need to masquerade from enemy sensors. The deployment of these objects with adaptive photochromic coatings with fast coloration & reversibility is highly effective way for their camouflaging. The present paper systematically reports the photochromic properties of W6+ transition metal doped TiO2 nanoparticles. Undoped as well as doped TiO2 nanoparticles have been synthesized by a one pot wet chemical method. The synthesized materials have been characterized by different techniques viz. XRD, AFM, Raman, SEM, EPR and UV–Vis spectroscopy. Photochromic behavior of functional material was studied by making its composite coatings in alkyd resin matrix. The effect of W6+ dopant ion concentration on photochromic properties has been explained. The coloration & reversibility characteristics of W6+: TiO2 is found superior as compared with V5+ & Mo6+ doped TiO2 nanomaterials, reported earlier.

Citrus viral infections pose a substantial threat to the global citrus industry, resulting in multitudinous economic losses annually. Timely and precise identification of citrus viruses offers a promising avenue for proactive insights preemptively before the instigation of extensive infections. The present study was devised to expedite the prompt identification of the presence of Citrus tristeza virus (CTV) within Nepalese citrus species utilizing a Double Antibody Sandwich-Enzyme-Linked Immunosorbent Assay (DAS-ELISA), followed by its validation using reverse transcription PCR (RT-PCR). Samplings extracted from plants harvested from 74 out of the 77 administrative districts within Nepal provide substantial evidence of extensive propagation of viral contagion among citrus cultivars across 64 districts (86.48%) of the nation. A comprehensive analysis of the samples obtained from diverse geographical localities revealed that 36 districts (48.64%) exhibit mild infestation, while 9 districts (12.16%) evince moderate infestation. Moreover, samples harvested from 19 districts (25.67%) were highly infected; intriguingly, specimens from 10 districts (13.51%) manifest an absence of viral intrusion. The results have been validated with RT-PCR assay. Given the profound significance of citrus as a pivotal repository of vitamin C and its essential role in conferring advantageous health attributes to humankind, alongside its substantial contribution to the economic paradigm, a meticulous examination is imperative to safeguard these plants against an array of viral infections. Collectively, the DAS-ELISA methodology along with RT-PCR approaches constitutes an exquisitely sensitive and meticulously specific modality, poised to accelerate the expeditious detection of citrus-associated viruses within burgeoning economies like Nepal. This advancement supports timely and precise detection and diagnosis of agriculturally virulent conditions, thereby forestalling the eruption of viral epidemics and concomitantly curbing their financial repercussions.

Campylobacter growth kinetic parameters can be used to refine the sensitivity and efficiency of microbial growth-based methods. Therefore, the aim of this study was to construct growth curves for C. jejuni, C. coli, and C. lari in pure culture and calculate growth kinetics for each Campylobacter species in the same environmental conditions. Campylobacter jejuni, C. coli and C. lari were grown over 48 h and inoculated into 15 mL Hungate tubes (N = 3 trials per species; 5 biological replicates per trial; 3 species; 1 strain per species). Absorbance measurements were taken in 45 min intervals over 24 h. Optical density readings were plotted versus time to calculate growth kinetic parameters. C. jejuni exhibited the longest lag phase (p < 0.001) at 15 h 20 min ± 30 min, versus C. coli at 11 h 15 min ± 17 min, and C. lari at 9 h 27 min ± 15 min. The exponential phase duration was no longer than 5 h for all species, and doubling times were all less than 1h 30 min. The variation in growth kinetics for the three species of Campylobacter illustrates the importance of determining individual Campylobacter spp. growth responses for optimizing detection based on low bacterial levels. This study provides kinetics and estimates to define enrichment times necessary for low concentration Campylobacter detection. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate alterations of the choroid in patients with a neurodegenerative disease versus healthy controls, a custom algorithm based on superpixel segmentation was used. Design: A cross-sectional study was conducted on data obtained in a previous cohort study. Subjects: Swept-source optical coherence tomography (OCT) B-scan images obtained using a Triton (Topcon, Japan) device were compiled according to current OSCAR IB and APOSTEL OCT image quality criteria. Images were included from three cohorts: multiple sclerosis (MS) patients, Parkinson disease (PD) patients, and healthy subjects. Only patients with early-stage MS and PD were included. Methods: In total, 104 OCT B-scan images were processed using a custom superpixel segmentation (SpS) algorithm to detect boundary limits in the choroidal layer and the optical properties of the image. The algorithm groups pixels with similar structural properties to generate clusters with similar meaningful properties. Main outcomes: SpS selects and groups the superpixels in a segmented choroidal area, computing the choroidal optical image density (COID), measured as the standard mean gray level, and the total choroidal area (CA), measured as px2. Results: The CA and choroidal density (CD) were significantly reduced in the two neurodegenerative disease groups (higher in PD than in MS) versus the healthy subjects (p < 0.001); choroidal area was also significantly reduced in the MS group versus the healthy subjects. The COID increased significantly in the PD patients versus the MS patients and in the MS patients versus the healthy controls (p < 0.001). Conclusions: The SpS algorithm detected choroidal tissue boundary limits and differences optical density in MS and PD patients versus healthy controls. The application of the SpS algorithm to OCT images potentially acts as a non-invasive biomarker for the early diagnosis of MS and PD. [ABSTRACT FROM AUTHOR]

Impedance microbiology was explored to provide insights into how a sensor that can monitor the growth of bacteria in vegetated bioretention systems (rain gardens) may be designed for in situ, real-time use. The impedance properties of Pseudomonas Putida samples were monitored under AC signals of 100 mV peak-to-peak and sweeping frequencies of 20 Hz-300 kHz, to determine relationships between these properties and biomass in the laboratory. The capacitance of the samples was found to be the most sensitive impedance parameter, with average change in magnitude of 37% due to bacterial growth. For verification, optical density measurements were taken and calibrated by direct hemocytometry counts of similar samples, simultaneously with the impedance testing. The experiments revealed that exponential relationships enable a good estimate of the biomass available in the medium, based on the change in capacitance. The detection range of the proposed system (in the range of tested strain) is approximately ~9.2 × 106 cells/mL to ~5 × 108 cells/mL. [ABSTRACT FROM AUTHOR]

Staphylococcal biofilms are an important virulence factor that allows for effective infectious effects and colonization of the animal body. This study was devoted to the evaluation of the biofilm forming ability of different strains of Staphylococcus pseudintermedius and Staphylococcus aureusisolated from animals in Ukraine. In addition, the presence of extracellular adhesin genes icaA and icaD in S. pseudintermedius strains was determined. The density of the biofilms was determined by culturing microorganisms in 96-well plates and staining the resulting structures with crystal violet. The genes responsible for biofilm formation were identified by classical polymerase chain reaction (PCR) using primers selected from the literature. The data obtained from this study showed a direct correlation between the density of the biofilm and the number of viable cells involved in its formation. Thus, 23.1% of S. pseudintermedius strains and 25% of S. aureus strains isolated from dogs demonstrated the ability to form a dense biofilm, while 46.2% of S. pseudintermedius strains and 50% of S. aureus strains formed a weak biofilm. The origin of the isolates had no significant effect on the biofilm characteristics. Coagulase-positive staphylococci obtained from cats did not form dense biofilms. 42.9% of methicillin-resistant Staphylococcus aureus(MRSA) isolates from cows with mastitis had moderate to strong biofilm forming properties. Isolates that showed resistance to three or more antibiotic groups tended to form denser biofilms. In addition, 73.3% of the studied S. pseudintermedius strains were found to contain the icaA gene, and 90% – the icaD gene. A genotypic profile combining both icaA and icaD genes was present in 66.7% of the bacteria, while one strain lacked both genes. Understanding the biofilm forming properties of staphylococcal isolates is important in the context of developing optimal treatment strategies and effective antibiotic use, which will contribute to better control of infections caused by these microorganisms. [ABSTRACT FROM AUTHOR]

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The aim of the study – comparative analysis of the ammonia level and Alzheimer type 2 astrocytes in the brain cortex and white matter of cerebral hemispheres, hippocampus, thalamus, striatum and cerebellum in the deceased patients with liver cirrhosis of classes A, B and C according to Child–Pugh. Materials and methods. The study was performed on the brain of deceased 90 patients (65 ± 3 years) suffered from non-alcoholic liver cirrhosis (LC) of classes A (n = 30, group “A”), B (n = 30, group “B”) and C (n = 30, group “C”) according to Child–Pugh score, among which 59 (65.55 %) patients had clinical symptoms of hepatic encephalopathy of I–IV grades. The control group included postmortem brains of 30 patients (59.0 ± 2.5 years) who died from acute cardiovascular insufficiency and did not suffer from liver diseases or intoxication. A retrospective analysis of clinical and laboratory data from case histories was carried out. For histochemical (HC) determination of the ammonia in paraffin sections of the cerebral cortex and white matter, hippocampus, thalamus, striatum and cerebellum we used the protocol with Nessler’s reagent proposed by Gutierrez-de-Juan et al. (2017). In the noted brain regions, the analysis of HC ammonia optical density was performed in five standardized fields of view (×200) of the microscope scope A1 “Carl Zeiss” (Germany) with Jenoptik camera progress Gryphax 60 N-C1ꞌꞌ1.0x426114 (Germany) using ImageJ software; in each noted brain region the number of Alzheimer’s type 2 astrocytes (AA2) was counted per twenty standardized fields of view at magnification ×400. Results. HC method for ammonia detection with Nessler’s reagent according to V. Gutiérrez-de-Juan et al. (2017) reveals region-dependent fine-grained expression of ammonia in the brain neuropil of deceased patients in control and cirrhotic groups. In control patients, a very low HC ammonia expression is observed with higher values in cerebellum, thalamus, and striatum, while still ranked as negative. Increased HC ammonia expression (compared to control) is observed in deceased patients with compensated LC of “A” group in the cortex, thalamus, striatum and cerebellum; in subcompensated LC of “B” group – as well in the white matter and hippocampus. In deceased patients with decompensated LC of “C” group, in cerebellum, thalamus and striatum HC ammonia expression is maximally increased (by 6.18, 5.72, and 5.50 folds, respectively). Significant correlations are present between patients’ postmortem brain HC ammonia expression and the last intravital indicators of the blood total bilirubin, AST, ALT, albumin, leukocytic intoxication index. In compensated cirrhosis, increase in AA2 numbers compared to control is found in thalamus, striatum and cerebellum, which corresponds to AA2-astrocytosis of I degree. In subcompensated cirrhosis, AA2-astrocytosis of moderate II degree is found in the cortex, thalamus and cerebellum; AA2-astrocytosis of I degree – in striatum. In decompensated cirrhosis, pronounced AA2-astrocytosis of III degree is determined in the cortex, thalamus, striatum and cerebellum; moderate AA2-astrocytosis of II degree – in cerebral white matter, and mild AA2-astrocytosis of I degree – in the hippocampus. There is a moderate, strong, and very strong positive relationship between the levels of AA2-astrocytosis and HC ammonia expression in the thalamus, striatum, and cerebellum. Conclusions. In deceased patients with LC, the neuropil HC ammonia expression in cerebellum, thalamus, striatum, and cerebral cortex directly correlates with the severity of LC according to Child–Pugh, reaching a maximum in LC of class C, and has significant correlations with intravital blood levels of total bilirubin, AST, ALT, albumin, leukocytic intoxication index. With LC progression, AA2-astrocytosis increases significantly in thalamus, cerebellum, striatum and cerebral cortex, which positively correlates with HC ammonia expression in these brain regions.

Acinetobacter baumannii) ABSTRACT: Background: Biofilms are composed of more than one species or often called polymicrobial biofilms, so research is needed on the formation of polymicrobial biofilms, especially between fungi and bacteria. This study aimed to analyze the total biomass and metabolic activity of biofilms formed from the interaction of fungi (Candida tropicalis) with bacteria (Staphylococcus aureus, MRSA, Pseudomonas aeruginosa, and Acinetobacter baumannii); Methods: Bacterial and fungal cultures were suspended in Tryptic Soy Broth (TSB) medium, then biofilm was cultivated in two 96-well microplates, then the microplates were incubated at 37 degrees Celsius for 48 hours. Detection of the biofilm will be carried out using the Crystal Violet assay and reduction of the tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide), or MTT assay to obtain the Optical Density (OD) value by using ELISA reader; Results: The results of this study obtained significant data from both parameters, the highest average value was found in the C. tropicalis treatment group (2,412 ± 0.825 on the biomass test results; 1,525 ± 0.473 on the metabolic activity test results), while the lowest was seen in the S. aureus treatment group (0.512 ± 0.224 in the biomass test results; 0.978 ± 0.349 in the metabolic activity test results); and Conclusions: In the total biomass parameter, it was obtained that the biofilm biomass could be formed strongly in each treatment, while the results of the metabolic activity showed that each treatment was able to carry out cell proliferation. [ J Adv Biotechnol Exp Ther 2023; 6(1.000): 84-93]

Chlorella vulgaris is of great importance in numerous exploratory or industrial applications (e.g., medicals, food, and feed additives). Rapid quantification of algal biomass is crucial in photobioreactors for the optimization of nutrient management and the estimation of production. The main goal of this study is to provide a simple, rapid, and not-resource-intensive estimation method for determining the algal density of C. vulgaris according to the measured parameters using UV–Vis spectrophotometry. Comparative assessment measurements were conducted with seven different methods (e.g., filtration, evaporation, chlorophyll a extraction, and detection of optical density and fluorescence) to determine algal biomass. By analyzing the entire spectra of diluted algae samples, optimal wavelengths were determined through a stepwise series of linear regression analyses by a novel correlation scanning method, facilitating accurate parameter estimation. Nonlinear formulas for spectrometry-based estimation processes were derived for each parameter. As a result, a general formula for biomass concentration estimation was developed, with recommendations for suitable measuring devices based on algae concentration levels. New values for magnesium content and the average single-cell weight of C. vulgaris were established, in addition to the development of a rapid, semiautomated cell counting method, improving efficiency and accuracy in algae quantification for cultivation and biotechnology applications.

Impedance microbiology was explored to provide insights into how a sensor that can monitor the growth of bacteria in vegetated bioretention systems (rain gardens) may be designed for in situ, real-time use. The impedance properties of Pseudomonas Putida samples were monitored under AC signals of 100 mV peak-to-peak and sweeping frequencies of 20 Hz–300 kHz, to determine relationships between these properties and biomass in the laboratory. The capacitance of the samples was found to be the most sensitive impedance parameter, with average change in magnitude of 37% due to bacterial growth. For verification, optical density measurements were taken and calibrated by direct hemocytometry counts of similar samples, simultaneously with the impedance testing. The experiments revealed that exponential relationships enable a good estimate of the biomass available in the medium, based on the change in capacitance. The detection range of the proposed system (in the range of tested strain) is approximately ∼9.2 × 106 cells/mL to ∼5 × 108 cells/mL.