Identification of a specific exporter that enables high production of aconitic acid in Aspergillus pseudoterreus.

Aconitic acid is an unsaturated tricarboxylic acid that is attractive for its potential use in manufacturing biodegradable and biocompatible polymers, plasticizers, and surfactants. Previously Aspergillus pseudoterreus was engineered as a platform to produce aconitic acid by deleting the cadA (cis-aconitic acid decarboxylase) gene in the itaconic acid biosynthetic pathway. In this study, the aconitic acid transporter gene (aexA) was identified using comparative global discovery proteomics analysis between the wild-type and cadA deletion strains. The protein AexA belongs to the Major Facilitator Superfamily (MFS). Deletion of aexA almost abolished aconitic acid secretion, while its overexpression led to a significant increase in aconitic acid production. Transportation of aconitic acid across the plasma membrane is a key limiting step in its production. In vitro, proteoliposome transport assay further validated AexA's function and substrate specificity. This research provides new approaches to efficiently pinpoint and characterize exporters of fungal organic acids and accelerate metabolic engineering to improve secretion capability and lower the cost of bioproduction.

Antifungal Activity of Industrial Bacillus Strains against Mycogone perniciosa, the Causative Agent of Wet Bubble Disease in White Button Mushrooms.

White button mushrooms yield instability in artificial cultivation, often caused by crop diseases. The main disease is wet bubble disease. The appearance of its causative agent, M. perniciosa, may lead to total yield loss. The microbiocontrol of M. perniciosa is focused on casing soil antagonist use. Since no industrial producer strains of polyfunctional biologics have been used in previous studies, our research goal was to characterize the effect of B. subtilis B-10 and M-22 on a mycopathogen and reveal its control possibilities. The reason for B. subtilis B-10 and M-22 use in mycopathogen control has been revealed by interactions between producer strains and the studying of M. perniciosa. The suppression of M. perniciosa development by producer strains was established, indicating a prolonged B-10 and M-22 effect on the mycopathogen. High biological efficacy in both strains at the early stages of mycopathogen development upon introducing them into the wells and spraying was shown: B-10-50.9-99.6% and M-22-57.5-99.2%, respectively (p ≤ 0.05). Significant differences between producer strains were not revealed, although during the first day of exposure to developed M. perniciosa colonies, M-22 showed greater activity. The high efficiency of preventive treatment when producer strains completely suppressed mycoparasite development permits us to recommend them both for introducing when preparing casing for M. perniciosa control.

Strain Streptomyces sp. P-56 Produces Nonactin and Possesses Insecticidal, Acaricidal, Antimicrobial and Plant Growth-Promoting Traits.

Streptomycetes produce a huge variety of bioactive metabolites, including antibiotics, enzyme inhibitors, pesticides and herbicides, which offer promise for applications in agriculture as plant protection and plant growth-promoting products. The aim of this report was to characterize the biological activities of strain Streptomyces sp. P-56, previously isolated from soil as an insecticidal bacterium. The metabolic complex was obtained from liquid culture of Streptomyces sp. P-56 as dried ethanol extract (DEE) and possessed insecticidal activity against vetch aphid (Medoura viciae Buckt.), cotton aphid (Aphis gossypii Glov.), green peach aphid (Myzus persicae Sulz.), pea aphid (Acyrthosiphon pisum Harr.) and crescent-marked lily aphid (Neomyzus circumflexus Buckt.), as well as two-spotted spider mite (Tetranychus urticae). Insecticidal activity was associated with production of nonactin, which was purified and identified using HPLC-MS and crystallographic techniques. Strain Streptomyces sp. P-56 also showed antibacterial and antifungal activity against various phytopathogenic bacteria and fungi (mostly for Clavibacfer michiganense, Alternaria solani and Sclerotinia libertiana), and possessed a set of plant growth-promoting traits, such as auxin production, ACC deaminase and phosphate solubilization. The possibilities for using this strain as a biopesticide producer and/or biocontrol and a plant growth-promoting microorganism are discussed.

Cryo-EM structure of the diapause chaperone artemin.

The protein artemin acts as both an RNA and protein chaperone and constitutes over 10% of all protein in Artemia cysts during diapause. However, its mechanistic details remain elusive since no high-resolution structure of artemin exists. Here we report the full-length structure of artemin at 2.04 Å resolution. The cryo-EM map contains density for an intramolecular disulfide bond between Cys22-Cys61 and resolves the entire C-terminus extending into the core of the assembled protein cage but in a different configuration than previously hypothesized with molecular modeling. We also provide data supporting the role of C-terminal helix F towards stabilizing the dimer form that is believed to be important for its chaperoning activity. We were able to destabilize this effect by placing a tag at the C-terminus to fully pack the internal cavity and cause limited steric hindrance.

Simulation of thermal field distribution in biological tissue and cell culture media irradiated with infrared wavelengths.

In recent years, there has been a growing interest in the singlet form of oxygen as a regulator of the physiological functions of cells. One of the ways to generate singlet oxygen is direct optical excitation of the triplet oxygen form. Since molecular oxygen weakly absorbs light, high power is required to obtain sufficient concentrations of singlet oxygen. However, the increase in the radiation power of laser can induce a local temperature increase around the laser spot. This may be critical considering the temperature governs every biological reaction within living cells, in particular. Here, the interaction of laser radiation of infrared wavelengths, generating singlet oxygen, with biological tissues and cell culture media was simulated. Using the COMSOL Multiphysics software, the thermal field distribution in the volume of skin, brain tissue and cell culture media was obtained depending on the wavelength, power and exposure time. The results demonstrate the importance of taking temperature into account when conducting experimental studies at the cellular and organismal levels.

Weak thermal state quadrature-noise shadow imaging.

In this work, we theoretically and experimentally demonstrate the possibility to create an image of an opaque object using a few-photon thermal optical field. We utilize the quadrature-noise shadow imaging (QSI) technique that detects the changes in the quadrature-noise statistics of the probe beam after its interaction with an object. We show that such a thermal QSI scheme has an advantage over the classical differential imaging when the effect of dark counts is considered. At the same time, the easy availability of thermal sources for any wavelength makes the method practical for broad range of applications, not accessible with, e.g., quantum squeezed light. As a proof of principle, we implement this scheme by two different light sources: a pseudo-thermal beam generated by rotating ground glass (RGG) method and a thermal beam generated by four-wave mixing (FWM) method. The RGG method shows simplicity and robustness of QSI scheme while the FWM method validates theoretical signal-to-noise ratio predictions. Finally, we demonstrate low-light imaging abilities with QSI by imaging a biological specimen on a CCD camera, detecting as low as 0.03 photons on average per pixel per 1.7 µs exposure.

Wave-front reconstruction via single-pixel homodyne imaging.

We combine single-pixel imaging and homodyne detection to perform full object recovery (phase and amplitude). Our method does not require any prior information about the object or the illuminating fields. As a demonstration, we reconstruct the optical properties of several semi-transparent objects and find that the reconstructed complex transmission has a phase precision of 0.02 radians and a relative amplitude precision of 0.01.

Coupling to short linear motifs creates versatile PME-1 activities in PP2A holoenzyme demethylation and inhibition.

Protein phosphatase 2A (PP2A) holoenzymes target broad substrates by recognizing short motifs via regulatory subunits. PP2A methylesterase 1 (PME-1) is a cancer-promoting enzyme and undergoes methylesterase activation upon binding to the PP2A core enzyme. Here, we showed that PME-1 readily demethylates different families of PP2A holoenzymes and blocks substrate recognition in vitro. The high-resolution cryoelectron microscopy structure of a PP2A-B56 holoenzyme-PME-1 complex reveals that PME-1 disordered regions, including a substrate-mimicking motif, tether to the B56 regulatory subunit at remote sites. They occupy the holoenzyme substrate-binding groove and allow large structural shifts in both holoenzyme and PME-1 to enable multipartite contacts at structured cores to activate the methylesterase. B56 interface mutations selectively block PME-1 activity toward PP2A-B56 holoenzymes and affect the methylation of a fraction of total cellular PP2A. The B56 interface mutations allow us to uncover B56-specific PME-1 functions in p53 signaling. Our studies reveal multiple mechanisms of PME-1 in suppressing holoenzyme functions and versatile PME-1 activities derived from coupling substrate-mimicking motifs to dynamic structured cores.

Clinical efficacy of hydroxyapatite toothpaste containing Polyol Germanium Complex (PGC) with threonine in the treatment of dentine hypersensitivity.

Introduction: This study aims to evaluate the clinical efficacy of a hydroxyapatite toothpaste containing a Polyol Germanium Complex with threonine in treating dentine hypersensitivity. The study also seeks to monitor the quality of life of the treated dentine hypersensitivity sufferers. Materials and methods: This study is a randomized clinical trial with a total of 120 patients with dentine hypersensitivity. All participants were divided into three groups: patients assigned to the GARDA SILK toothpaste; patients receiving the conventional fluoride toothpaste for comparison purposes, and patients asked to brush their teeth without toothpaste. The modified Quigley-Heine Plaque Index was assessed at the baseline and after treatment. Sensitivity was assessed at baseline, 3, 7 and 14 days using the air stimulus (Schiff Index). The impact of dentine hypersensitivity on the quality of life was assessed before and after the treatment with the Russian version of the Dentine Hypersensitivity Experience Questionnaire (DHEQ). Results: After 14 days of treatment, the mean Plaque Index scores in Groups 1 and 2 did not exceed 1 and averaged 0.72 ± 0.249 and 0.86 ± 0.213, respectively. In Group 3, the mean Plaque Index was significantly higher (1.04 ± 0.070, p < 0.05). The mean Schiff sensitivity scores in Group 1 decreased to 2.45 ± 0.42 at 3 days, 1.84 ± 0.26 at 7 days, and 1.02 ± 0.34 at 14 days. Group 2 exhibited smaller reductions in the Schiff index at all time points. In this group, Schiff scores dropped to 2.67 ± 0.28 after 3 days, 2.34 ± 0.44 after 7 days, and 1.93 ± 0.36 after 14 days. Conclusion: The GARDA SILK hydroxyapatite toothpaste with a threonine-containing Polyol Germanium Complex (PGC) is effective in maintaining good oral hygiene, reducing dentine hypersensitivity, and improving the quality of life of dentine hypersensitivity sufferers.

Cognitive Abilities and Academic Achievement as Intercultural Competence Predictors in Russian School Students.

The development of intercultural competence (ICC) is important for the modern personality in an unstable and diverse world, but there is a lack of research on this phenomenon in the context of age, gender and intellectual differences. The purpose of the present exploratory study is to identify relations between ICC, cognitive abilities and academic achievements among Russian school students. The sample included 106 (55% female) students in the 9th grade of Moscow secondary school. ICC was measured with the author's modification of The Intercultural Sensitivity Scale by Khuhlaev and Chibisova, developed on the basis of the Developmental Model of Intercultural Sensitivity by Bennett. Cognitive abilities were determined with the School Test of Intellectual Development by Akimova et al. Academic achievements were evaluated using GPA. The findings of our research show that: (1) higher academic achievements and cognitive abilities usually characterize schoolchildren, who are not inclined to absolutize cultural differences and do not consider them to be barriers to intercultural interaction; (2) the most significant predictors of ICC features from the studied cognitive abilities are analogy and generalization, but generalization has opposite impacts in male and female students. This fact should be taken into account in the context of ICC developments, especially in male school students prone to ethnocentrism.

Laser-induced singlet oxygen selectively triggers oscillatory mitochondrial permeability transition and apoptosis in melanoma cell lines.

Singlet oxygen (1O2) is an electronically excited state of triplet oxygen which is less stable than molecular oxygen in the electronic ground state and produced by photochemical, thermal, chemical, or enzymatic activation of O2. Although the role of singlet oxygen in biology and medicine was intensively studied with photosensitisers, using of these compounds is limited due to toxicity and lack of selectivity. We generated singlet oxygen in the skin fibroblasts and melanoma cell lines by 1267 nm laser irradiation. It did not induce production of superoxide anion, hydrogen peroxide or activation of lipid peroxidation in these cells confirming high selectivity of 1267 nm laser to singlet oxygen. 1O2 did not change mitochondrial membrane potential (ΔΨm) in skin fibroblasts but induced fluctuation in ΔΨm and complete mitochondrial depolarisation due to opening permeability transition pore in B16 melanoma cells. 1267 nm irradiation did not change the percentage of fibroblasts with necrosis but significantly increased the number of B16 melanoma cells with apoptosis. Thus, singlet oxygen can induce apoptosis in cancer B16 melanoma cells by opening of mitochondrial permeability transition pore (PTP) but not in control fibroblasts.

Interpersonal Mindfulness, Intergroup Anxiety, and Intercultural Communication Effectiveness Among International Students Studying in Russia.

In modern psychology, mindfulness is an important resource for psychological well-being and intergroup relations, but its role in intercultural communication effectiveness has not been sufficiently studied. This research aims to identify the interrelationship between interpersonal mindfulness, intergroup anxiety, and intercultural communication effectiveness among international students. The sample includes 337 (M age = 22.93, SD = 3.11) international students (41.5% of females) from different countries studying in Russian Universities. Interpersonal mindfulness was measured using the Interpersonal Mindfulness Scale, Intergroup anxiety using ten items adapted from Stephan and Stephan and used in Gudykunst and Nishida, and Intercultural communication effectiveness using the eight items adapted from Gudykunst's Perceived Effectiveness of Communication measure. Descriptive analysis, correlations, and mediation analyses were used to process the data. The research findings showed that interpersonal mindfulness has both a direct effect on intercultural communication effectiveness and a mediation effect on intercultural communication effectiveness through intergroup anxiety among the international students.

New Polyfunctional Biorationals Use to Achieve Competitive Yield of Organic Potatoes in the North-West Russian Ecosystem.

To increase the organic potato yield, it is necessary to provide the crop with sufficient nutrients and effective means of biocontrol the diseases. The research goal was to characterize the biorationals' efficacy to achieve competitive organic potatoes' yield under various weather conditions. A 4-year trial was carried out in the Leningrad region using Udacha variety potatoes. The tests used liquid forms of new polyfunctional biologicals Kartofin based on highly active Bacillus subtilis I-5-12/23 and organic fertilizer BIAGUM obtained from poultry manure by aerobic fermentation in a closed biofermenter. Significant stimulation in plant growth and development to the flowering phase regardless of the hydrothermal conditions of the growing season was noted. The stimulating effect was determined by the combined use of biorationals pro rata to BIAGUM dose. Kartofin biologicals and BIAGUM almost doubled the potato tubers' yield compared to the control, regardless of the growing season conditions. At the flowering phase, the biological efficacy in potato fungal diseases incidence and development was near 90% under optimal and 50-75% under drought hydrothermal conditions. At the end of vegetation, the efficiency in fungal diseases incidence and development made up 45-65% under optimal and 45-70% under dry conditions. BIAGUM effectiveness in reducing disease development reached 45-50% regardless of growing season conditions.

Interaction of Mitochondrial Calcium and ROS in Neurodegeneration.

Neurodegenerative disorders are currently incurable devastating diseases which are characterized by the slow and progressive loss of neurons in specific brain regions. Progress in the investigation of the mechanisms of these disorders helped to identify a number of genes associated with familial forms of these diseases and a number of toxins and risk factors which trigger sporadic and toxic forms of these diseases. Recently, some similarities in the mechanisms of neurodegenerative diseases were identified, including the involvement of mitochondria, oxidative stress, and the abnormality of Ca2+ signaling in neurons and astrocytes. Thus, mitochondria produce reactive oxygen species during metabolism which play a further role in redox signaling, but this may also act as an additional trigger for abnormal mitochondrial calcium handling, resulting in mitochondrial calcium overload. Combinations of these factors can be the trigger of neuronal cell death in some pathologies. Here, we review the latest literature on the crosstalk of reactive oxygen species and Ca2+ in brain mitochondria in physiology and beyond, considering how changes in mitochondrial metabolism or redox signaling can convert this interaction into a pathological event.

De novo sequencing and native mass spectrometry revealed hetero-association of dirigent protein homologs and potential interacting proteins in Forsythia × intermedia.

The discovery of dirigent proteins (DPs) and their functions in plant phenol biochemistry was made over two decades ago with Forsythia × intermedia. Stereo-selective, DP-guided, monolignol-derived radical coupling in vitro was then reported to afford the optically active lignan, (+)-pinoresinol from coniferyl alcohol, provided one-electron oxidase/oxidant capacity was present. It later became evident that DPs have several distinct sub-families, presumably with different functions. Some known DPs require other essential enzymes/proteins (e.g. oxidases) for their functions. However, the lack of a fully sequenced genome for Forsythia × intermedia made it difficult to profile other components co-purified with the (+)-pinoresinol forming DP. Herein, we used an integrated bottom-up, top-down, and native mass spectrometry (MS) approach to de novo sequence the extracted proteins via adaptation of our initial report of DP solubilization and purification. Using publicly available transcriptome and genomic data from closely related species, we identified 14 proteins that were putatively associated with either DP function or the cell wall. Although their co-occurrence after extraction and chromatographic separation is suggestive for potential protein-protein interactions, none were found to form stable protein complexes with DPs in native MS under the specific experimental conditions we have explored. Interestingly, two new DP homologs were found and they formed hetero-trimers. Molecular dynamics simulations suggested that similar hetero-trimers were possible between Arabidopsis DP homologs with comparable sequence similarities. Nevertheless, our integrated mass spectrometry method development helped prepare for future investigations directed to the discovery of novel proteins and protein-protein interactions. These advantages can be highly beneficial for plant and microbial research where fully sequenced genomes may not be readily available.

Tunable Heteroassembly of a Plant Pseudoenzyme-Enzyme Complex.

Pseudoenzymes have emerged as key regulatory elements in all kingdoms of life despite being catalytically nonactive. Yet many factors defining why one protein is active while its homologue is inactive remain uncertain. For pseudoenzyme-enzyme pairs, the similarity of both subunits can often hinder conventional characterization approaches. In plants, a pseudoenzyme, PDX1.2, positively regulates vitamin B6 production by association with its active catalytic homologues such as PDX1.3 through an unknown assembly mechanism. Here we used an integrative experimental approach to learn that such pseudoenzyme-enzyme pair associations result in heterocomplexes of variable stoichiometry, which are unexpectedly tunable. We also present the atomic structure of the PDX1.2 pseudoenzyme as well as the population averaged PDX1.2-PDX1.3 pseudoenzyme-enzyme pair. Finally, we dissected hetero-dodecamers of each stoichiometry to understand the arrangement of monomers in the heterocomplexes and identified symmetry-imposed preferences in PDX1.2-PDX1.3 interactions. Our results provide a new model of pseudoenzyme-enzyme interactions and their native heterogeneity.

Influence of Professional Teeth Whitening on Oral Hygiene: Long-term Results.

AIMS: The aim of this article is to estimate the long-term influence of professional dental bleaching on quality of oral hygiene (year after procedure). MATERIALS AND METHODS: A randomized controlled prospective clinical repeated study was carried out 6 months after the previous one, i.e., 1 year after the oral hygiene procedure, among 60 patients divided into two groups. In the first group, professional oral hygiene and bleaching using 25% hydrogen peroxide were performed. In the second group only, oral hygiene was performed. Dynamics of hygienic index of Quigley-Hein modified by S. Turesky was estimated. RESULTS: In the first group, the average value of the hygienic index of Quigley-Hein modified by S. Turesky was significantly lower a year after procedure than before (1.33±0.09 and 2.34±0.14, respectively). In the second group, this index exceeded 2.45 and nearly returned to the initiated level (2.45±0.07 and 2.44±0.08, respectively). Patients underwent professional teeth whitening in the long-term period, and the level of oral hygiene was significantly higher than that in the control group. CONCLUSION: Professional dental bleaching has good long-term influence on the level of oral hygiene and serves as a significant motivation factor for maintaining health of oral cavity.

Quantum-enhanced two-photon spectroscopy using two-mode squeezed light.

We investigate the prospects of using two-mode intensity squeezed twin beams, generated in Rb vapor, to improve the sensitivity of spectroscopic measurements by engaging two-photon Raman transitions. As a proof-of-principle demonstration, we recorded quantum-enhanced measurements of the Rb 5D3/2 hyperfine structure with reduced requirements for the Raman pump laser power and Rb vapor number density.

Optical Diagnostics of the Maxillary Sinuses by Digital Diaphanoscopy Technology.

The work is devoted to the development of a scientific and technical basis for instrument implementation of a digital diaphanoscopy technology for the diagnosis of maxillary sinus inflammatory diseases taking into account the anatomical features of patients (differences in skin structure, skull bone thickness, and sinus size), the optical properties of exercised tissues, and the age and gender characteristics of patients. The technology is based on visualization and analysis of scattering patterns of low-intensity radiation as it passes through the maxillary sinuses. The article presents the experimental data obtained using the digital diaphanoscopy method and the results of numerical simulation of the optical radiation passage through the study area. The experimental setup has been modernized through the installation of a a device for controlling the LED applicator brightness. The approach proposed may have considerable promise for creating diagnostic criteria for various pathological changes and can be used to assess the differences in the optical and anatomical features of males and females.

Coherent optical processes with an all-optical atomic simulator.

We show how novel photonic devices such as broadband quantum memory and efficient quantum frequency transduction can be implemented using three-wave mixing processes in a 1D array of nonlinear waveguides evanescently coupled to nearest neighbors. We do this using an analogy of an atom interacting with an external optical field using both classical and quantum models of the optical fields and adapting well-known coherent processes from atomic optics, such as electromagnetically induced transparency and stimulated Raman adiabatic passage to design. This approach allows the implementation of devices that are very difficult or impossible to implement by conventional techniques.