Exponential Stage Research Articles

Growth stage-related capsular polysaccharide translocon Wza in Vibrio splendidus modifies phage vB_VspM_VS2 susceptibility

Bacteria at different growth stages usually coordinate capsular polysaccharide (CPS) formation and may affect their susceptibility to phage. In this study, we evaluated the infection efficacy of phage vB_VspM_VS2 in V. splendidus AJ01 at different growth stages and explored the role of growth stage-related CPS translocon Wza in the susceptibility of V. splendidus to phage vB_VspM_VS2. The results showed that V. splendidus locked in the stationary growth stage (SGS) or early exponential stage (EES) infected with phage (EES-P) has a low susceptibility to phage vB_VspM_VS and exhibit a pronounced reduction in phage adsorption rate as compared to the EES bacteria. The expression of wza of CPS transport gene was significantly increased in EES bacteria compared to that bacteria locked in the SGS or EES-P. Bacteria with deleted wza (Δwza mutant) escaped phage adsorption due to absence of Wza mediated down-regulation of CPS expression, otherwise. Our results reveal that the Wza of V. splendidus can promotes phage to infect these bacteria via increasing the phage absorption, which provides important implications for using phages therapeutically target pathogenic bacteria in dynamics communities.

Perkembangan Asuransi Syariah di Indonesia Ditinjau dari Pertumbuhan Eksponensial

The purpose of this study is to determine the six exponential processes experienced by Islamic insurance companies in Indonesia. The research method used is qualitative method. This research uses a literature approach sourced from books, journals and articles that are in accordance with the topic and focus of the research. The literature study method is used in this research to find scientific and theoretical studies. The analysis technique used uses the concept of exponential growth which consists of six stages. The results of this study show that sharia insurance in Indonesia has gone through exponential stages similar to technological developments in other industries. Six stages such as digitalization, deception, disruption, dematerialization, demonetization and democratization have adopted technology and found new ways to integrate those innovations into the business, allowing to increase efficiency, lower costs, and provide added value to customers. PT Asuransi Jasindo Syariah is one of the sharia insurance companies in Indonesia that shows a significant increase to reach the democratization stage, because it is not only a sharia insurance application, but there are many choices of features other than insurance such as several Islamic articles, sadaqah features and the implementation of cash waqf.

Effects of biomass feedstock and applied pressure on the binding mechanism and pellet qualities

To expand the sources of feedstocks for pelleting and enhance the applicability of the pelleting device, 7 types of feedstocks with representative chemical component contents from different resources were densified. The pressure-time (P-T) curves and energy consumption were used to analyze the densification process and binding mechanism. Specific energy density and densification effects were evaluated pellet qualities and classified feedstock types. Results showed that the densification process was first affected by the feedstock types and then applied pressure. Biomass chemical component contents significantly influence the densification process, the required time, and the final pellet length. Energy consumption in the compression stage is much more than in the extrusion stage. The exponential stage consumes more than 90 % of the total energy. Energy conversion efficiency varies from 62.19 % to 95.06 % with the feedstock types and applied pressures. Single pellet density, densification effects, and specific energy densities increased with the rising applied pressure. BB, SD, PN, CS, and SB can be used as primary feedstocks. SR and ROC act as secondary feedstocks or lubricants. Cellulose, hemicellulose, and lignin of plant cell walls are solid bridges. Extractives, fat, and protein in the plant cells are binders and lubricants to make the pellet surface smooth. This paper could provide further insight into various biomass feedstock densification and general design for pelleting devices.

Elite-guided Resampling and Multi-mutation based Differential Evolution with exponential crossover for numerical optimization

In the existing Differential Evolution (DE) research, there are two main crossover schemes: exponential crossover and binomial crossover. Most researchers believe that binomial crossover is skilled in handling numerical optimization problems while exponential crossover has the advantage in handling optimization problems with certain correlation between adjacent variables. However, we discover that DE variants with exponential crossover can achieve performance comparable to advanced ones utilizing binomial crossover in optimization applications, provided that an appropriate crossover rate CR and associated parameter control are established. In this paper, an Elite-guided Resampling and Multi-mutation based DE with exponential crossover (ERM-DE) is raised to fill the blank in this field, and its main highlights are as follows: First, a novel structure with two stages is raised in our ERM-DE algorithm. The first stage is elite-guided global opposition learning based resampling, and the other is novel exponential crossover DE evolution stage. Second, a Novel Parameter Control (NPC) technique involving scale factor F and crossover rate CR is raised. Different from applying the fitness-based parameter control, the adaptation schemes of the parameters F and CR in our ERM-DE algorithm are fitness-independent. In addition, this NPC technique will also be selectively applied to the trial vector generation strategy DE/target-to-pbest/1/exp with or without optional archive. Third, a novel population Diversity Enhancement Mechanism (DEM) is proposed, which can enhance population diversity by recalculating individuals in a stagnant state. Finally, a time stamp mechanism is posed to deal with outdated inferior and historical solutions in the external archive. A Large test suite with 88 benchmark functions from CEC2013, CEC2014, and CEC2017 test suites is used for algorithm validation and the experimental results indicate that our ERM-DE demonstrates competitiveness with several state-of-the-art DE variants.

Impact of the expansion ratio on the properties of hydrogen recirculation ejectors

Exploring the development characteristics and influencing factors of the mixing layer (ML) inside the hydrogen recirculation ejector is of great importance for enhancing the recirculation properties of the ejector and promoting green and sustainable energy development. However, the evolution of ML in the ejector and the transport and diffusion characteristics of the fluid are problematic, in particular, the influence of the expansion ratio on the properties of the ejector is unclear. Therefore, in this study, a CFD numerical model of an ejector was established to simulate the flow of fluids in the ejector. The evolution of ML was elucidated, and the interaction mechanism between the mixing and the recirculation performance of the ejector was revealed. The findings showed that the velocity difference is a significant driving force for the development of ML, and the formation of an adverse pressure gradient contributes to the diffusion of hydrogen and the rapid development of ML. The development process of ML in the ejector can be divided into three stages under the interaction of the velocity difference and the convective Mach number: the rapid growth stage, the slow growth stage, and the exponential growth stage. By studying the evolution of ML at different expansion ratios, it was found that there exists a critical expansion ratio for the ejector, which results in the largest of the non-mixing length ratio and the effective mixing thickness, the strongest relative mass transfer capability of the entrained flow, the fullest development of ML, and the optimal hydrogen recirculation performance.

Adverse effects of Microcystis aeruginosa exudates on the filtration, digestion, and reproduction organs of benthic bivalve Corbicula fluminea

Cyanobacteria bloom and the secondary metabolites released by the microorganism are extremely harmful to aquatic animals, yet study on their adverse effects in zoobenthos is rare. Corbicula fluminea widely distributed in freshwater environment with algal blooms. It is a typical filter feeding zoobenthos that may be affected by the secondary metabolites of cyanobacteria due to its high filtering rate. In this study, C. fluminea was exposed to Microcystis aeruginosa exudates (MaE) for 96 h, which was obtained from 5 × 105 cells/mL and 2.5 × 106 cells/mL exponential stage M. aeruginosa culture solution that represented cyanobacteria cell density needs environmental risk precaution control and emergent control, respectively. The responses of C. fluminea critical organs to MaE were analyzed and evaluated based on histopathological sections, antitoxicity biomarkers, and organ function biomarkers. The results showed that all the organs underwent structural disorders, cell vacuolization, apoptosis, and necrosis, and the damage levels increased as MaE concentration increased. The detoxification and antioxidant defense systems biomarkers in each organ response to MaE exposure differently and the level of reaction improved when MaE concentration increased. The siphon rate and acetylcholinesterase activity showed that the filtration function decreased significantly as the MaE concentration increased. Increased activity of glutathione S-transferase and amylase in the digestive gland indicate that it is the major detoxification organ of C. fluminea. Increased vitellogenin concentration and enlarged oocytes in the gonad indicate that MaE may have an estrogenic effect on C. fluminea. This study demonstrates that cyanobacteria threat benthic bivalves by inducing oxidative stress, inhibiting filtering feeding system, and disturbing digestion system and reproduction potential of C. fluminea.

Regulation of the PFK1 gene on the interspecies microbial competition behavior of Saccharomyces cerevisiae

Saccharomyces cerevisiae is a widely used strain for ethanol fermentation; meanwhile, efficient utilization of glucose could effectively promote ethanol production. The PFK1 gene is a key gene for intracellular glucose metabolism in S. cerevisiae. Our previous work suggested that although deletion of the PFK1 gene could confer higher oxidative tolerance to S. cerevisiae cells, the PFK1Δ strain was prone to contamination by other microorganisms. High interspecies microbial competition ability is vital for the growth and survival of microorganisms in co-cultures. The result of our previous studies hinted us a reasonable logic that the EMP (i.e., the Embden-Meyerhof-Parnas pathway, the glycolytic pathway) key gene PFK1 could be involved in regulating interspecies competitiveness of S. cerevisiae through the regulation of glucose utilization and ethanol production efficiency. The results suggest that under 2% and 5% glucose, the PFK1Δ strain showed slower growth than the S288c wild-type and TDH1Δ strains in the lag and exponential growth stages, but realized higher growth in the stationary stage. However, relative high supplement of glucose (10%) eliminated this phenomenon, suggesting the importance of glucose in the regulation of PFK1 in yeast cell growth. Furthermore, during the lag growth phase, the PFK1Δ strain displayed a decelerated glucose consumption rate (P < 0.05). The expression levels of the HXT2, HXT5, and HXT6 genes decreased by approximately 0.5-fold (P < 0.05) and the expression level of the ZWF1 exhibited a onefold increase in the PFK1Δ strain compared to that in the S. cerevisiae S288c wild-type strain (P < 0.05).These findings suggested that the PFK1 inhibited the uptake and utilization of intracellular glucose by yeast cells, resulting in a higher amount of residual glucose in the medium for the PFK1Δ strain to utilize for growth during the reverse overshoot stage in the stationary phase. The results presented here also indicated the potential of ethanol as a defensive weapon against S. cerevisiae. The lower ethanol yield in the early stage of the PFK1Δ strain (P < 0.001) and the decreased expression levels of the PDC5 and PDC6 (P < 0.05), which led to slower growth, resulted in the strain being less competitive than the wild-type strain when co-cultured with Escherichia coli. The lower interspecies competitiveness of the PFK1Δ strain further promoted the growth of co-cultured E. coli, which in turn activated the ethanol production efficiency of the PFK1Δ strain to antagonize it from E. coli at the stationary stage. The results presented clarified the regulation of the PFK1 gene on the growth and interspecies microbial competition behavior of S. cerevisiae and would help us to understand the microbial interactions between S. cerevisiae and other microorganisms.Key points• PFK1Δ strain could realize reverse growth overshoot at the stationary stage• PFK1 deletion decreased ethanol yield and interspecific competitiveness• Proportion of E. coli in co-culture affected ethanol yield capacity of yeast cells

Effect of a cyclonic eddy on phytoplankton: A bioassay experiment

AbstractCyclonic eddies often increase the primary productivity of marine ecosystems. However, the study of their influence on the taxonomic structure and productivity of plankton is complex due to the short‐term and mesoscale nature of the action of eddies. In a laboratory bioassay experiment, we simulated two mechanisms of eddy's effect on the deep phytoplankton maximum: an increase in the upward flow of deep nutrients and illumination. Doubling of nutrient additions compared to control increased chlorophyll's specific growth rate (SGR) 1.7‐fold over 12 days while doubling the light intensity increased SGR by 3.5 times. During the first 4 days of the experiment, at the exponential growth stage, SGR of carbon biomass was maximum with the simultaneous doubling of nutrients and light (0.44 day−1). It was statistically significantly higher than at increased nutrients but not light. These results suggest that nutrient deficiencies were less crucial for phytoplankton growth than light. The increase in the phytoplankton biomass was mainly due to the growth of a large‐celled diatom Pseudosolenia calcar‐avis. It showed the highest SGR (1.15–1.28 day−1) at increased nutrients and/or light, resulting in high wet biomass of 2–3 g m−3 over 4 days. The ecological meaning of the obtained results is as follows. First, in the eddy, where the deep phytoplankton maximum is located close to the nutricline, its rise to more illuminated layers results in higher phytoplankton growth than the shortening distance to the nutricline. Second, increases in the upward flow of nutrients and light intensity, separate or simultaneous, stimulate the rapid reproduction of large‐celled diatoms that increase the carbon‐to‐chlorophyll ratio by 2–4 times. Third, exposure to a typical Black Sea mesoscale cyclonic eddy can lead to phytoplankton blooms in the thermocline within a few days.

Kinetics of bacterial cellulose formation in soybean-boiled wastewater medium during fermentation utilizing real-time image processing

The bacterial cellulose (BC) fermentation is affected by environmental growth conditions such as pH, temperature, and turbidity. During the fermentation, a real-time image processing method was applied to observe the BC growth by using soybean-boiled wastewater and coconut water as a mixture. Cellulose will be produced and discharged into the medium throughout the fermentation process to form BC sheets, which will gradually become visible. The purpose of this study is to investigate the correlation between the growth parameters of BC and to analyze the formation of BC kinetically, using the Gompertz model on medium without additional nitrogen source and medium with additional nitrogen sources during the fermentation process. The strongest correlation result was found between time and thickness of BC formed without an additional nitrogen source, and with sodium glutamate as the nitrogen source. The Gompertz model equation was suitable for predicting the kinetics of BC formation time and thickness based on the available data. Both mediums exhibited three clusters that represented the adaptation stage, the exponential stage, and the stationary stage during the fermentation process. The addition of a nitrogen source to the medium resulted in thicker BC sheets compared to the medium without this addition.

Physiological and Biochemical State of Green Microalgae (Chlorophyta) under Different Nutrients' Content in the Cultural Medium

The physiological and biochemical state of green microalgae &lt;i&gt;Tetradesmus dimorphus&lt;/i&gt; (Turpin) M.J. Wynne and &lt;i&gt;Desmodesmus brasiliensis&lt;/i&gt; (Bohlin) E. Hegew at different growth phases depending on the nutrients' content in the cultural medium was investigated. Maximal cell numbers, specific growth rate and biomass increment in &lt;i&gt;T. dimorphus&lt;/i&gt; were recorded at the exponential stage under high concentrations of nitrate nitrogen and phosphorus of phosphates, and in &lt;i&gt;D. brasiliensis&lt;/i&gt; - under low. The increase of the cells' division frequency resulted in their lesser size and increase of length/width ratio. Maximal content of lipids and carbohydrates in the cells of &lt;i&gt;T. dimorphus &lt;/i&gt;was recorded at the end of the exponential stage over cultivation in the medium with low initial concentrations of nitrate nitrogen and phosphorus of phosphates, and in &lt;i&gt;D. brasiliensis&lt;/i&gt; -with high content. At this is no difference in the proteins' content in their cells was revealed.

Comparative genomics analysis of Streptococcus iniae isolated from Trachinotus ovatus: novel insight into antimicrobial resistance and virulence differentiation

BackgroundStreptococcus iniae is an important fish pathogen that cause significant economic losses to the global aquaculture industry every year. Although there have some reports on the genotype of S.iniae and its relationship with virulence, no genome-scale comparative analysis has been performed so far. In our previous work, we characterized 17 isolates of S.iniae from Trachinotus ovatus and divided them into two genotypes using RAPD and rep-PCR methods. Among them, BH15-2 was classified as designated genotype A (in RAPD) and genotype 1 (in rep-PCR), while BH16-24 was classified as genotype B and genotype 2. Herein, we compared the differences in growth, drug resistance, virulence, and genome between BH15-2 and BH16-24.ResultsThe results showed that the growth ability of BH16-24 was significantly faster than that of BH15-2 at the exponential stage. Antimicrobial tests revealed that BH15-2 was susceptible to most of the tested antibiotics except neomycin and gentamycin. In contrast, BH16-24 was resistant to 7 antibiotics including penicillin, sulfasomizole, compound sulfamethoxazole tablets, polymyxin B, spectinomycin, rifampin and ceftazidime. Intraperitoneal challenge of T.ovatus, showed that the LD50 value of BH15-2 was 4.0 × 102 CFU/g, while that of BH16-24 was 1.2 × 105 CFU/g. The genome of S.iniae BH15-2 was 2,175,659 bp with a GC content of 36.80%. Meanwhile, the genome of BH16-24 was 2,153,918 bp with a GC content of 36.83%. Comparative genome analysis indicated that compared with BH15-2, BH16-24 genome had a large-scale genomic inversion fragment, at the location from 502,513 bp to 1,788,813 bp, resulting in many of virulence and resistance genes differentially expression. In addition, there was a 46 kb length, intact phage sequence in BH15-2 genome, which was absent in BH16-24.ConclusionComparative genomic studies of BH15-2 and BH16-24 showed that the main difference is a 1.28 Mbp inversion fragment. The inversion fragment may lead to abnormal expression of drug resistant and virulence genes, which is believed to be the main reason for the multiple resistance and weakened virulence of BH16-24. Our study revealed the potential mechanisms in underlying the differences of multidrug resistance and virulence among different genotypes of S.iniae.

Kinetic Energy Exchanges between a Two-Dimensional Front and Internal Waves

Abstract Fronts and near-inertial waves (NIWs) are energetic motions in the upper ocean that have been shown to interact and provide a route for kinetic energy (KE) dissipation of balanced oceanic flows. In this paper, we study these KE exchanges using an idealized model consisting of a two-dimensional geostrophically balanced front undergoing strain-induced semigeostrophic frontogenesis and internal wave (IW) vertical modes. The front–IW KE exchanges are quantified separately during two frontogenetic stages: an exponential sharpening stage that is characterized by a low Rossby number and is driven by the imposed strain (i.e., mesoscale frontogenesis), followed by a superexponential sharpening stage that is characterized by an Rossby number and is driven by the convergence of the secondary circulation (i.e., submesoscale frontogenesis). It is demonstrated that high-frequency IWs quickly escape the frontal zone and are very efficient at extracting KE from the imposed geostrophic strain field through the deformation shear production (DSP). Part of the extracted KE is then converted to wave potential energy. On the contrary, NIWs remain locked to the frontal zone and readily exchange energy with the ageostrophic frontal circulation. During the exponential stage, NIWs extract KE from the geostrophic strain through DSP and transfer it to the frontal secondary circulation via the ageostrophic shear production (AGSP) mechanism. During the superexponential stage, a newly identified mechanism, convergence production (CP), plays an important role in the NIW KE budget. The CP transfers KE from the convergent ageostrophic secondary circulation to the NIWs and largely cancels out the KE loss due to the AGSP. This CP may explain previous findings of KE transfer enhancement from balanced motions to IWs in frontal regions of realistic ocean models. We provide analytical estimates for the aforementioned energy exchange mechanisms that match well the numerical results. This highlights that the strength of the exchanges strongly depends on the frontal Rossby and Richardson numbers. Significance Statement Fronts with large horizontal density and velocity gradients are ubiquitous in the upper ocean. They are generated by a process known as frontogenesis, which is often initialized by straining motions of mesoscale balanced circulations. Here we examine the energy exchanges between fronts and internal waves in an idealized configuration, aiming to elucidate the mechanisms that can drain energy from oceanic balanced circulations. We identify a new mechanism for energy transfers from the frontal circulation to near-inertial internal waves called convergence production. This mechanism is especially effective during the later stages of frontogenesis when the convergent ageostrophic secondary circulation that develops is strong.

О значении хемосистематической корреляции при изучении аллелопатического потенциала аборигенных и чужеродных видов трав

This abstract presents the results of screening for allelopathic activity of three pairs “aboriginal-exotic” of comparison species of herbs, including invasive species, systematically related at the level of the genus. It was shown that a 1% leaf extract of Solidago virgaurea and S. canadensis, Pulmonaria obscura and P. saccharata, Veronica serpyllifolia and V. filiformis had a similar or equal inhibitory effect on the germination and growth of test-plant roots in biotests owing to its chemosystematic correlation. Extracts of Solidago and Pulmonaria species slowed down the rate of germination and root growth by 1.5–2 times lower than the control. In the Salidago sp. experiment options the dynamics of the processes developed according to the type of stress-reaction. The absolute rate of root growth at the exponential stage differed twice in the Solidago sp. options: 16.8±0.43 and 8.99±0.23 mm/day in native and exotic specie, respectively. The total germination was close to or equal to the control level. In a comparison pair Pulmonaria sp. germination decreased by 58.66 and 43.5%. V. filiformis extract inhibited germination by 24.4% more than the native species. Extracts 0.05% extracts of Solidago sp. had no effect, P. saccharata and V. filiformis extracts caused the effects of hormesis. P. saccharate option produced an – acceleration of the absolute and relative root growth rate of the test-plants by two times, exceeding the total length of the roots by half compared to the control and the native species. In the V. filiformis option, the rates of germination and root growth was inhibited by 24.7 and 50.2% of the values of the paired species, respectively. The comparative method increases the level of analysis of bioassay data, allows for a deeper study of the specifics of test-plants reactions, and allows the evaluation of the modes of action of allelochemics.

Combining AFM, XPS and chemical hydrolysis to understand the complexity and dynamics of C. vulgaris cell wall composition and architecture

The microalgae cell wall represents its interface with its environment, and is a dynamic and complex structure that evolves depending on the growth phase or culture conditions. To apprehend this complexity, an experimental approach combining AFM, XPS, and chemical hydrolysis followed by HPAEC-PAD was developed to understand the cell wall of Chlorella vulgaris, a biotechnologically-relevant green microalgae species. Exponential and stationary growth stages were investigated, as well as saline stress condition inducing lipid production. Results showed that both the cell wall composition and architecture changes in stationary phase, with an increase of the lipidic fraction at the expense of the proteic fraction, changes in the polysaccharidic composition, and a significant increase of its rigidity. Under saline stress, cell wall architecture seems to be affected as importantly, its rigidity is reduced. Altogether, this study demonstrates the power of combining these three techniques to give new insights into C. vulgaris cell wall, in terms of composition and architecture, and of its dynamics in different conditions.

Predicting the evolution of static yield stress with time of blended cement paste through a machine learning approach

Predicting the static yield stress (τ0S) is relevant to design innovative concrete technologies. This paper evaluated three machine learning methods to choose the most accurate model to predict the growth of τ0S of blended cement pastes. Eight input parameters were used, including supplementary cementitious material (SCM) properties, cement reactivity, mixture design parameters, and resting time. Among the evaluated methods, the multilayer perceptron was the most accurate. Results showed that τ0S during the initial linear growth stage is controlled by the SCM properties. However, the τ0S during the later exponential growth stage is controlled by the amount of pseudo-contact zones.

Constitutive Expression of a Cytotoxic Anticancer Protein in Tumor-Colonizing Bacteria.

Bacterial cancer therapy is a promising next-generation modality to treat cancer that often uses tumor-colonizing bacteria to deliver cytotoxic anticancer proteins. However, the expression of cytotoxic anticancer proteins in bacteria that accumulate in the nontumoral reticuloendothelial system (RES), mainly the liver and spleen, is considered detrimental. This study examined the fate of the Escherichia coli strain MG1655 and an attenuated strain of Salmonella enterica serovar Gallinarum (S. Gallinarum) with defective ppGpp synthesis after intravenous injection into tumor-bearing mice (~108 colony forming units/animal). Approximately 10% of the injected bacteria were detected initially in the RES, whereas approximately 0.01% were in tumor tissues. The bacteria in the tumor tissue proliferated vigorously to up to 109 colony forming units/g tissue, whereas those in the RES died off. RNA analysis revealed that tumor-associated E. coli activated rrnB operon genes encoding the rRNA building block of ribosome needed most during the exponential stage of growth, whereas those in the RES expressed substantially decreased levels of this gene and were cleared soon presumably by innate immune systems. Based on this finding, we engineered ΔppGpp S. Gallinarum to express constitutively a recombinant immunotoxin comprising TGFα and the Pseudomonas exotoxin A (PE38) using a constitutive exponential phase promoter, the ribosomal RNA promoter rrnB P1. The construct exerted anticancer effects on mice grafted with mouse colon (CT26) or breast (4T1) tumor cells without any notable adverse effects, suggesting that constitutive expression of cytotoxic anticancer protein from rrnB P1 occurred only in tumor tissue.

A-luminescence in CsI:Tl crystal excited by pulsed electron beam

The amplitude-time parameters of the A-luminescence at 3.12 eV are studied for CsI:Tl irradiated by a pulsed electron beam at temperatures 77–295 K. It has been established that the 3.12 eV band kinetics varies differently with temperature in two temperature ranges of 77–170 K and 170–295 K. The increase in temperature from 77 K to 170 K causes the decrease in the exponential decay time constant, while at temperatures above 170 K, there appeared the post-radiation rise stage followed by the slow exponential decay stage. The temperature behavior of the A-luminescence kinetics is interpreted in term of the model, according to which (i) the A band is due to the allowed electron transition 61P1 → 61S0 of Tl+ ions and (ii) the main excitation mechanism across the entire cathodoluminescence spectrum of CsI:Tl at temperatures near room temperature is the spontaneous disintegration of donor–acceptor dipoles [Tl0Vk].

Improved particle filter remaining life prediction method for switch mode power supply using variance of case temperature

Switch mode power supply plays a crucial role in industrial systems as an energy source. Its remaining life prediction is vital to help in schedule maintenance to avoid the unexpected failures of industrial systems. Due to the high cost of monitoring the degradation characterization parameter and the complexity of the degradation rule, predicting remaining life for the switch mode power supply is challenging. This study used a novel degradation characterization parameter, i.e., the variance of the case temperature, to characterize switch mode power supply degradation. Multi-stage state equations and degradation thresholds of each stage were established based on the change in the variance of the case temperature. Additionally, the state equations and degradation thresholds were introduced into the traditional particle filter method to form an improved particle filter, which is a useful life prediction method. The effect of the proposed method was evaluated and compared with other methods. The results show that over the life of a switch mode power supply, there are three change stages in the variance of the case temperature: the constant tendency stage, linear increase stage, and exponential increase stage. The degradation thresholds of these stages were 20 %, 70 %, and 200 %, respectively. The predicted curve of the variance of the case temperature was in good agreement with the test curve, and the prediction interval at a 90 % confidence level was narrow. Compared with other algorithms, the improved particle filter method could maintain the prediction error within 5 %, and was more suitable for predicting the remaining life of a switch mode power supply with multi-stage degradation characteristics.

Minimizing the Lag Phase of Cupriavidus necator Growth under Autotrophic, Heterotrophic, and Mixotrophic Conditions.

Cupriavidus necator has the unique metabolic capability to grow under heterotrophic, autotrophic, and mixotrophic conditions. In the current work, we examined the effect of growth conditions on the metabolic responses of C. necator. In our lab-scale experiments, autotrophic growth was rapid, with a short lag phase as the exponential growth stage was initiated in 6 to 12 h. The lag phase extended significantly (>22 h) at elevated O2 and CO2 partial pressures, while the duration of the lag phase was independent of the H2 or N2 partial pressure. Under heterotrophic conditions with acetate as the organic substrate, the lag phase length was short (<12 h), but it increased with increasing acetate concentrations. When glucose and glycerol were provided as the organic substrate, the lag phase was consistently long (>12 h) regardless of the examined substrate concentrations (up to 10.0 g/L). In the transition experiments, C. necator cells showed rapid transitions from autotrophic to heterotrophic growth in less than 12 h and vice versa. Our experimental results indicate that C. necator can rapidly grow with both autotrophic and heterotrophic substrates, while the lag time substantially increases with nonacetate organic substrates (e.g., glucose or glycerol), high acetate concentrations, and high O2 and CO2 partial pressures. IMPORTANCE The current work investigated the inhibition of organic and gaseous substrates on the microbial adaption of Cupriavidus necator under several metabolic conditions commonly employed for commercial polyhydroxyalkanoate production. We also proposed a two-stage cultivation system to minimize the lag time required to change over between the heterotrophic, autotrophic, and mixotrophic pathways.

Regulation of Lysozyme Activity by Human Hormones

Lysozyme is a part of human and animal noncellular immunity. The regulation of its activity by hormones is poorly studied. The aim of this study was to test the in vitro activity of lysozyme in the presence of catecholamines, natriuretic hormones, and estradiol (E2). Hormones were incubated with lysozyme, and the activity of lysozome was further determined using a test culture of Micrococcus luteus in the early exponential growth stage. The activity of lysozyme was assessed based on the rate of change in the OD of the test culture. Molecular docking was performed using SwissDock server http://www.swissdock.ch/docking), and molecular structures were further analyzed and visualized in the UCSF Chimera 1.15rc software. According to the results, epinephrine and norepinephrine increased lysozyme activity up to 180% compared to the hormone-free enzyme. Changing the pH of the medium from 6.3 to 5.5, increased the lysozyme activity in the presence of E2 up to 150-200 %. The results also showed that exposure to hormones could modify lysozyme ctivity, and this effect depends on the temperature and pH value. The molecular docking revealed a decrease in the activation energy of the active site of enzyme during the interaction of catecholamines with the amino acid residues, asp52 and glu35 of the active site. Our findings demonstrate an additional mechanism for the involvement of lysozyme in humoral regulation of nonspecific immunity with respect to human pathogenic microflora and bacterial skin commensals by direct modulation of its activity using human hormones.