Optimum Temperature Research Articles

The effect of hot extraction on total flavonoid content in Moringa leaves aquous extract

Moringa oleifera leaves extract is some natural compound rich in antioxidants such as vitamins, phenolic acids, flavonoids, isothiocyanates, tannins, and saponins. Until recently, this plant has been widely used as an antioxidant source and as a vegetable in the Indonesian community. Previous studies have demonstrated that the extraction with methanol and ethanol are effective because they have the ability to extract both the lower and higher molecular sizes of antioxidant compounds. However, the extraction of this compound using water has not yet been established. In this report, we investigated the total phenolic compound of Moringa leaves extract. Moreover, the flavonoid compound of Moringa oleifera leaves aquous extract has been characterized by using of several temperatures (40⁰, 70⁰, and 100⁰ C) in order to mimic the real-life condition in the community. Here we showed that the phenolic compound in Moringa oleifera leaves aquous extract is 1.01%. Moreover, using quercetin standard, we evaluate the concentration of flavonoid in Moringa oleifera leaves aquous extract. We found that the flavonoid compound of Moringa oleifera leaves aquous extract with the temperature of 40⁰, 70⁰, and 100⁰ C were for 5.245 μg/ml; 7.725 μg/ml; 5.728 μg/ml respectively. This report confirms the optimum temperature for Moringa leaves aquous extract is 70°C in order to obtain the maximum flavonoid compound.

Engineering dual-functional and thermophilic BMHETase for efficient degradation of polyethylene terephthalate

Polyethylene terephthalate (PET) biodegradation is hindered by the intermediates bis (2-hydroxyethyl) terephthalate (BHET) and mono (2-hydroxyethyl) terephthalate (MHET). BMHETase, a thermophilic hydrolase identified from the UniParc database, exhibits degradation activity towards both BHET and MHET. BMHETase showed higher activity on BHET than LCCICCG and FASTPETase at temperatures ranging from 50 to 70℃. To enhance its activity in degrading MHET, BMHETase was engineered to mimic Ideonella sakaiensis MHETase. The resulting 6-point mutant’s activities on MHET and BHET were 8 and 2 times those of the WT, with both optimal temperatures increased by 5℃. This enhancement may be attributed to the BMHETase6M’s intensified binding ability with MHET and enlarged binding pocket. When combined with LCCICCG, BMHETase6M achieved complete degradation of MHET in PET films to terephthalic acid, indicating broad application potential. These findings suggest that BMHETase6M holds promise as a candidate for enhancing PET biodegradation efficiency and plastic waste management.

SIMULATION HEATING PROCESS FOR WEAKLY REACTIVE COAL IN THE HORIZONTAL REACTOR

In this study results of the active medium parameters influence formed by hot air on the thermal heating process of weakly reactive coal from the formation «Maikubensk 3B» for the extraction of additional heat are represented. In the course of the research the regularities of the hygroscopic moisture and volatile combustible substances release for the obtaining additional heat have been determined. Optimal temperature ranges of the stage heating taking into account thermal destruction of coal in the temperature range from 20 C to 600 C, the main steps of the insulated heating process, the moisture content gradient propagation lines and dependence of the heat transfer and mass transfer coefficients on the temperature and the humidity during the thermal heating process in the horizontal coal heating reactor. The results show that it is possible to release volatile combustible gases with a gradual increase of temperatures in the obtained mode. The heating mode comprises a pre-heating stage with hydroscopic moisture release, in the temperature range from 20 C to 105 C, the stage of isothermal heating in the temperature range from 105 C to 400 C and the phase of flame-free combustion in the temperature range from 400 C to 600 C with the temperature rise above the set value. Process simulation was carried out in the Comsol Multiphisics software environment for the weakly reactive coal real-world heating conditions. Keywords: coal heating, weakly reactive coal, isothermal heating, step-by-step heating, Lagrange method, non-liner equation, non-stationary process.

Study on Pseudomonas spp. isolated from pork and chicken meat

Pseudomonas spp. are heterotrophic, Gram-negative, aerobic bacteria widely distributed in the environment, acting as food spoilage agents and opportunistic pathogens in humans. In this study, we applied the ISO 13720:2010 for enumeration of presumptive Pseudomonas spp. in meat and meat products to investigate the contamination of Pseudomonas spp. in pork and chicken meat samples collected from markets in various districts of Ho Chi Minh City. The results indicated that 78% of pork samples and 72% of chicken samples were contaminated with Pseudomonas spp., with average densities of 4.9×106 CFU/g and 6.8×106 CFU/g, respectively. Almost isolated Pseudomonas strains could grow at neutral and alkaline pH, with an optimal temperature range of 10°C to 44°C, and tolerate to NaCl 5%. These findings provide critical information on the distribution and growth characteristics of Pseudomonas spp. in meat, therefore, being a premise to propose the research on density thresholds to ensure food quality.

The 3Cat-4 Spacecraft Thermal Analysis and Thermal Vacuum Test Campaign Results

3Cat-4 is the fourth member of the CubeSat series of UPC’s NanoSat Lab, and it was selected by the ESA Academy’s Fly Your Satellite! program in 2017. This mission aims at demonstrating the capabilities of nano-satellites, and in particular those based in the 1-Unit CubeSat standard, for challenging Earth Observation (EO) using Global Navigation Satellite System-Reflectometry (GNSS-R) and L-band microwave radiometry, as well as for Automatic Identification Systems (AIS). The following study presents the results of the thermal analysis carried out for this mission, evaluating different scenarios, including the most critical cases at both high and low temperatures. The results consider different albedos and orbital parameters in order to establish the optimal temperatures to achieve the best mission performance within the nominal temperatures, and in all operational modes of the satellite. Simulation results are included considering the thermal performance of other materials, such as Kapton, as well as the redesign of the optical properties of the satellite’s solar panels. The correlation with the thermal model and the TVAC test campaign was conducted at the ESA ESEC-GALAXIA facilities in Belgium.

Отримання жароміцного гомогенного сплаву методом пресування та спікання суміші порошків (Nb-21Ti-5Al-10Cr-7Mo) ат. %

Multicomponent high temperature strength alloys of the Nb-Ti-Al system, alloyed with Cr, Zr, Mo and Si, with a specific gravity of 6.3 - 7.4 g/cm3, have proven extremely promising in aviation and space technology. However, their physical and chemical features are associated with the high activity of the components, with a significant difference in melting temperatures (from Tmel. Mo – 2617 °C to Tmel. Al – 660 °C) and different specific gravity (from 10.2 g/cm3- Mo up to 2.7 g/cm3- Al), is a big problem for their production. The long crystallization interval of cast alloys of this system, thermophysical features of their crystallization, determine the possibility of formation of dendritic structures, the development of dendritic liquation and segregation of low- or high-temperature intermetallics and eutectics, the tendency to the formation of crystallization cracks, which reduces the operational characteristics of cast alloys. In this regard, it became necessary to investigate the possibilities of obtaining an alloy by the method of powder metallurgy. The purpose of this work was to obtain a homogeneous alloy, to study changes in the grain structure, phase transformations and mechanical properties of the material at various stages of processing in the process of obtaining a homogeneous alloy structure by powder metallurgy methods. The need to protect powder components from oxidation, formation of nitrides, carbides during technological operations at temperatures above 200 °C (high-purity argon) has been established. The optimal duration of intensive grinding of a mixture of powders and granules of raw materials has been worked out, which makes it possible to control the uniformity of the size of the particles of the mixture components, porosity and homogeneity of the alloy. The optimal duration of grinding is 30 minutes, during which the most homogeneous mixture in terms of particle size is formed. The optimal annealing mode was established, which ensures the achievement of homogenization of the alloy, phase transformations at the boundaries of the contact of component particles, and changes in grain sizes. Microstructural and X-ray structural analysis of the samples was carried out, their microhardness and grain dispersion were determined. Keyword: high-temperature strength niobium alloys, physical and chemical features, powder metallurgy, homogeneity, microstructure, mechanical properties, phase composition.

EFFECT OF ANNEALING DURATION ON PHOTOCATALYTIC PROPERTIES OF LaFeO3 PEROVSKITE

In this paper, the effect of the annealing duration on the photocatalytic properties of lanthanum ferrite perovskite synthesized by the hydrothermal method is investigated. Lanthanum ferrite was chosen as the object of study due to its high activity under the influence of visible light. During the experiments, the structural changes occurring in the material during annealing during 2, 4 and 6 hours were studied. The main attention was paid to the analysis of the morphology of nanoparticles, phase composition, crystallinity, absorption spectra and photocatalytic activity. The results show that an increase in the annealing time leads to an improvement in the crystal structure, an increase in the size of crystallites and a higher level of oxygenation. The optimal annealing time to achieve maximum photocatalytic activity was determined to be 6 hours. The work confirms the prospects of using long-term annealing to improve the photocatalytic properties of perovskite-based materials.

A molecular genetic toolkit for the differential expression analysis of soybean β-conglycinin subunit genes

The majority of proteins in soybean seeds are storage ones, including β-conglycinin and glycinin, which are necessary for seed germination. At the same time, they are the most valuable soy proteins used in the food industry, since their subunit composition and proportion of total protein can affect the quality of the resulting food product. β-conglycinins are trimers with different composition of subunits which are designated as α', α, β and encoded by the CG-1, CG-3, and CG-4 genes, respectively. The PCR analysis employed a model soybean cultivar ‘Sentyabrinka’. A complementary DNA synthesized from the RNA isolated from seeds of the studied cultivar served as a template. The in silico created pairs of primers for CG-1, CG-3, and CG-4 gene transcripts were used. As the result of PCR and the analysis of the obtained electrophoregrams, optimal annealing temperatures of primers for the CG-1, CG-3 and CG-4 genes were selected, at which only the characteristic fragment was observed. Thus, a molecular genetic toolkit has been developed for a comprehensive study of the qualitative and quantitative composition of soybean protein and can be used for further analysis of differential expression of genes responsible for the synthesis of β-conglycinin subunits.

Genomic characterization of antibiotic-resistant Staphylococcus epidermidis with observed shifts in optimal temperature.

Antibiotic resistance genes (ARGs) in the environment pose significant public health concerns and are influenced by conditions like temperature changes. We previously observed that resistance evolution to gentamicin and colistin affects optimal growth temperatures in Staphylococcus epidermidis isolates. Despite significant phenotype observations, the genetic basis remains unclear. We aim to identify the genetic changes linked to antibiotic resistance evolution that alter optimal growth temperature. Using whole-genome sequencing, we sequenced the genomes of gentamicin-resistant (GEN-1, GEN-2) and colistin-resistant (COL-4, COL-6) S. epidermidis isolates. Variant analysis with the BV-BRC bioinformatics tool identified genes involved in antibiotic resistance and temperature response. We found 12 genetic variants, including two unique to GEN-2 and one in COL-4. One shared mutation was observed in GEN-1 and GEN-2, and another in COL-4 and COL-6. Five mutations were shared among all isolates related to mobile gene elements, including a transposase IS4 family, two putative transposases, and two transposase-like insertion elements. Our findings indicate that the same genes involved in gentamicin and colistin resistance, especially those related to mobile genetic elements, may also play a crucial role in temperature response.

Structural optimization and battery temperature prediction of battery thermal management system based on machine learning

Lithium-ion batteries significantly extend the driving range for electric motorcycles. The battery thermal management system (BTMS) is critical for achieving optimal battery performance. Moreover, precise battery temperature prediction is essential for efficient thermal management. Therefore, a battery thermal management system integrating air and phase change material (PCM) cooling is proposed. Initially, the impact of PCM height, PCM thickness, and air velocity on battery temperature is analyzed. Subsequently, with cost minimization as the objective and ensuring that the maximum battery temperature remains below a threshold, the Black Kite Algorithm (BKA) is employed to optimize the BTMS structure. Finally, a BKA-Convolutional Neural Network (CNN)-Self Attention (SA) model is introduced for battery temperature prediction. The results indicate that increasing the thickness of the PCM and air velocity facilitates battery heat dissipation but with diminishing marginal effects. An increase in PCM height enhances battery cooling at low air velocities but becomes detrimental at high air velocities. The optimized PCM height is 35 mm, resulting in a cost of 0.073 USD for the BTMS per battery. Additionally, the BKA-CNN-SA model achieved a maximum error of 0.45 °C on the validation set and accurately predicted battery temperature changes before and after PCM melting.

A novel method for the degradation of human blood clot by immobilised bromelain using multi-walled carbon nanotube and polyphenol oxidase

Pathological blood clot in blood vessels, which often leads to cardiovascular diseases, are one of the most common causes of death in humans. Therefore, enzymatic therapy to degrade blood clots is vital. To achieve this goal, bromelain was immobilized and used for the biodegradation of blood clots. Bromelain was extracted from the pineapple fruit pulp (Ananas comosus) and purified by ion exchange chromatography after precipitation with ammonium sulphate (0-80 %), resulting in a yield of 70%, purification fold of 1.42, and a specific activity of 1175 U/mg. Bromelain was covalently immobilized on functionalized multi-walled carbon nanotubes (MWCNT), with an enzyme loading of 71.35%. The results of the characterization of free and immobilized bromelain demonstrated that the optimum pH for free and immobilized bromelain activity was 7.0, while the pH range of stability was from 5.0 to 8.5 and 4.0 to 9.0, respectively. The optimum temperature for free and immobilized bromelain activity was 45ºC, whereas the stability was 15 to 50°C and 15 to 55°C, respectively. The immobilized bromelain activity was decreased after the fifth reuse, and the storage period of the free and immobilized bromelain was decreased after 6 and 123 days, respectively. Casein was the best substrate-free bromelain, and fibrin was the best substrate for immobilized bromelain. The results of the purification of polyphenol oxidases (PPO) from potatoes by ion exchange chromatography gave a yield of about 54 %, a purification fold of 1.27, and a specific activity of 2804 U/mg. The current study showed that the immobilized bromelain can significantly biodegrade human blood clots in vitro, while the PPO enzyme has no significant effect on blood clots.

Evolution of a biological thermocouple by adaptation of cytochrome c oxidase in a subterrestrial metazoan, Halicephalobus mephisto

In this study, we report a biological temperature-sensing electrical regulator in the cytochrome c oxidase of the Devil Worm, Halicephalobus mephisto. This extremophile metazoan was isolated 1.3 km underground in a South African goldmine, where it adapted to heat and potentially to hypoxia, making its mitochondrial sequence a likely target of adaptational change. We obtained the complete mitochondrial genome sequence of this organism and show through dN/dS analysis evidence of positive selection in H. mephisto cytochrome c oxidase subunits. Seventeen of these positively selected amino acid substitutions were located in proximity to the H- and K-pathway proton channels of the complex. Surprisingly, the H. mephisto cytochrome c oxidase completely shuts down at low temperatures (20 °C), leading to a 4.8-fold reduction in the transmembrane proton gradient (ΔΨm) compared to optimal temperature (37 °C). Direct measurement of oxygen consumption found a corresponding 4.6-fold drop at 20 °C compared to 37 °C. Correspondingly, the lifecycle of H. mephisto takes four times longer at low temperature than at higher. This elegant evolutionary adaptation creates a finely-tuned mitochondrial temperature sensor, allowing this ectothermic organism to maximize its reproductive success across varying environmental temperatures.

EVALUATION OF TECHNOLOGICAL PLASTICITY OF HIGH BORON CORROSION-RESISTANT STEEL DURING HOT DEFORMATION OF PIPES USED FOR SPENT NUCLEAR FUEL STORAGE

Statement of the problem. The sustainable development of the global nuclear power industry in the future depends on how effectively the problems of radiation safety and nuclear proliferation are addressed. Such problems occur, among other things, at the final stage of the nuclear fuel cycle – spent fuel management. This task is currently on the agenda of both the international community and national governments of countries that develop or intend to develop nuclear energy [1−3]. Today, in connection with ensuring the safety of nuclear energy, boron-containing steels are widely used in the world practice as a material for biological protection and for the manufacture of special equipment parts. This is due to the fact that the B10 isotope in steels provides neutron capture [4]. Hexagonal pipes made of high-boron steel were needed to shield the support cover of the compacted spent fuel storage facility at nuclear power plants. Corrosion-resistant steels alloyed with boron are widely used in the nuclear power industry due to their special nuclear properties. During the operation of nuclear power plants, fuel assemblies that have served their useful life must be stored in special storage facilities using containers – hexagonal tubes made of 04Сr14Ti3B2V steel. To reduce costs during in the construction and operation of NPPs, part of the spent nuclear fuel management should be performed at Ukrainian enterprises. This will provide a significant import substitution effect. To manufacture hexagonal tubes from 04Сr14Ti3B2V steel according to the ingot-hot deformation-profiling-heat treatment scheme, it is necessary to develop the parameters of hot deformation and subsequent technological operations. The use of these pipes in compacted spent fuel storage facilities of NPPs will allow to increase the storage capacity by 2 times, which will give a significant national economic effect Material and methods of research. Material used for the study was steel 04Сr14Ti3B2V (CS-82), smelted using two variants (vacuum-induction – “VI” and vacuum-induction followed by vacuum-arc remelting – (“VD”). Steel grade 04Сr14Ti3B2V belongs to high-alloy, corrosion-resistant ferritic steels with a high boron content of up to 2 %. The method of differential thermal analysis was used to study the phase transformation temperatures in the steel. X-ray diffraction and micro-X-ray spectral analysis were used to assess the phase state. The steel samples were tested for weldability After cooling, the welded samples were subjected to X-ray transmission [5]. Hot twisting tests and mechanical tests at high temperatures were also performed. The macro- and microstructure of the metal was studied. Results. The macro- and microstructure of steel was evaluated depending on the smelting method. The phase composition of the steel was studied. The study of the plastic properties of steel ChS-82 by means of penetration and hot twisting tests showed that the temperature range of maximum plasticity is in a wide range (from 1 025 to 1 150 0C) with a rather low resistance to deformation. During hot deformation in the temperature range of 1 175 0C and above, metal fracture was observed along the grain boundaries at the melting points of the Cr−Fe−B boride phase. The optimal temperature range for hot deformation of steel ChS-82 is 1 000−1 050 ⁰С. Scientific novelty. For corrosion-resistant high boron steel used for spent nuclear fuel storage, the temperature range of hot deformation was selected and the structural and phase composition was estimated, which will allow deforming the metal on the piercing mill and manufacturing pipes.

Multireference calculations on bond dissociation and biradical polycyclic aromatic hydrocarbons as guidance for fractional occupation number weighted density analysis in DFT calculations

This study explores open-shell biradical and polyradical molecular compounds based on extended multireference (MR) methods (MR-configuration interaction with singles and doubles (CISD) and MR-averaged quadratic coupled cluster (AQCC) approach) using the numbers of unpaired densities NU. These results were used to guide the analysis of the fractional occupation number weighted density (FOD) calculated within the finite temperature (FT) density functional theory (DFT) approach. As critical test examples, the dissociation of carbon–carbon (CC) single, double and triple bonds and a benchmark set of polycyclic aromatic hydrocarbons (PAHs) have been chosen. By examining single, double, and triple bond dissociations, we demonstrate the utility and accuracy but also limitations of the FOD analysis for describing these dissociation processes. In significant extension of previous work (Phys Chem Chem Phys 25: 27380–27393), the assessment of FOD applications for different classes of DFT functionals was performed examining the range-separated functionals ωB97XD, ωB97M-V, CAM-B3LYP, LC-ωPBE, and MN12-SX, the hybrid (M06-2X) functional and the double hybrid (B2P-LYP) functional. In all cases, strong correlations between NFOD and NU values are found. The major task was to develop a new linear regression formula for range-separated functionals allowing a convenient determination of the optimal electronic temperature Tel for the FT-DFT calculation. We also established an optimal temperature for the semiempirical extended tight-binding GFN2-xTB method. These findings significantly broaden the applicability of FOD analysis across various DFT functionals and semiempirical methods.

Cloning of Three Aflatoxin B1 Oxidases of the Dipeptidyl Peptidase III Family and Evaluation of Their Potential for Practical Applications as Decontamination Enzymes.

Aflatoxin B1 (AFB1) produced by some Aspergillus species belongs to the most dangerous contaminants of animal feeds. Development of safe and cost efficient decontamination methods saving feed quality and nutritional value are of paramount importance. The use of recombinant AFB1-detoxifying microbial enzymes represents a promising biotechnological approach meeting the aforementioned requirements. In this study, three AFB1-degrading oxidases (AFOs) from edible basidiomycetes Cantharellus cibarius, Lentinula edodes and Pleurotus eryngii as well as AFO from Armillaria tabescens were expressed in E. coli Rosetta (DE3) and purified by immobilized metal-chelate chromatography. The stabilizing effect of the addition of glycerol and β-mercaptoethanol during protein extraction is shown. The catalytic constants of the recombinant AFOs (rAFOs) and other characteristics, which might be important for their practical application (and optimal temperature and pH, thermolability, regulation of the activity by metal ions and chelating agents, storage stability) were investigated. Among the obtained enzymes, rAFO from P. eryngii (Pe-AFO), which was characterized by the highest specific activity, thermostability and pH stability (especially at acidic pH range), the lowest Km, and relative resistance to the inhibition by phytate, showed the best AFB1-degrading efficacy. However, Pe-AFO and all other rAFOs significantly decreased the target activity during heating above 45 °C, storage frozen or lyophilization.

Synthesis of rice husk derived porous carbon as low-cost and high-performance electrode material for supercapacitors

Porous carbon electrode materials derived from agricultural by-products of food processing have attracted widespread interest. Rice husk (RH) is a promising raw material owing to its abundance and low price. In this study, a supercapacitor electrode was prepared by using recycled RH and secondarily activated with ZnCl2 to enhance its electrochemical energy storage performance. RH carbonized at the optimum temperature (i.e., 800 °C) was activated to synthesize RH-800-X (X = 1, 2, 3, 4, or 5, representing the mass ratio of ZnCl2 to RH-800). Sample RH-800-3 exhibited the highest specific surface area (1348.29 m2 g−1) and mesoporous pore volume (0.8375 cm3 g−1) among the samples. In a three-electrode system, the prepared electrodes delivered a high specific capacitance (242 F g−1 at 0.3 A g−1 in 6 M KOH solution). Furthermore, the capacitance retention of RH-800-3 remained at 99.9 % after 17,000 charge/discharge cycles. The results demonstrate the excellent capacitive behavior and superior electrochemical performance of RH-800-3. In addition, symmetrical capacitors prepared using RH-800-3 have an energy density of up to 101 Wh kg−1 at a power density of 900 W kg−1. Therefore, this study presents a simple and effective method for preparing a high-performance electrode material from biomass-derived porous carbon (i.e., recycled RH) and offers a new perspective for the efficient utilization of waste biomass resources.

Comparison analysis of three CO2-based binary mixtures performing in the supercritical Brayton cycle for molten salt energy storage

It is generally acknowledged that using CO2-based binary mixtures as working fluids in supercritical recompression Brayton cycle for waste heat recovery is a promising technique. This study examines the performance of CO2-Kr (0.76/0.24) and CO2-Xe (0.56/0.44) mixtures, comparing them with pure CO2. Both thermodynamic and thermo-economic considerations are taken into account to establish optimal parameter settings. The findings suggest that the minimum system temperature should be around but not below the critical temperature of the working fluid. The system performs badly at lower pressures and shows nearly the same at higher pressures, with 25 MPa being the recommended value for the main compressor. When the system split ratio and the low temperature recuperator temperature difference are well matched, the heat exchangers exhibit an optimal temperature distribution. The exergy loss distributions of the exchangers in the CO2-Kr and CO2-Xe systems are likewise rather uniform when the input pressure of the main compressor is above the critical pressure of the fluid, typically between 0.2 MPa and 0.4 MPa, enhancing system efficiency. The corresponding temperature difference of the LTR should be within 5 °C above or below the critical temperature of the fluid. This advantageous feature is not immediately apparent in the pure SCO2 cycle.

Application of Anionic Hydrogels from Date Palm Waste for Dye Adsorption in Wastewater Treatment.

This work aimed to develop an anionic cellulose nanofiber (CNF) bio-adsorbent from date palm tree waste and to investigate its removal efficiency compared to cationic methylene blue dye from contaminated water. Date palm pulp was first prepared from date palm leaves through acid hydrolysis using H2SO4, followed by hydrolysis in a basic medium using KOH, in which the process completely removed the components of hemicellulose, lignin, and silica. To obtain anionic CNF, the resulting pulp was further treated with H2SO4, followed by centrifugation. Biogel formation of the CNF suspension was promoted by sonication, where its removal efficiency of methylene blue dye was studied as a function of dye concentration, temperature, contact time, and pH value. In this work, we investigated two isotherms, i.e., Langmuir and Freundlich. The Langmuir model's consistency with the experimental data suggests that the adsorption of methylene blue dye onto CNF is monolayer and surface-limited. The reported maximum removal efficiency of 5 mg/g at 60 °C indicates the optimal temperature for adsorption in this specific case. Additionally, a pseudo-second-order model and Elovich model were also utilized to obtain a better understanding of the adsorption mechanism, in which we found not just physical adsorption but also an indication of a chemical reaction occurring between methylene blue dye and CNF. According to the results, that pseudo-second-order model's consistency with the experimental data suggests that the adsorption of methylene blue (MB) onto CNF is rate-limiting step involving chemisorption between the two. The study reveals that CNF adsorbents derived from renewable natural waste sources such as date palm leaves can be effective in removing cationic contaminants such as methylene blue dye.

PRODUCTION AND CHARACTERIZATION OF CELLULASES FROM ASPERGILLUS NIGER UNDER STATIC FERMENTATION

The ever-increasing uses of cellulase in various industries have made it popular among researchers. Annually, a large amount of fruit wastes go into vain, which is a great source of cellulases. The objective of this study is to use grape wastes as substrate for production of cellulases from Aspergillus niger using static fermentation. CMCase and FPase assays were performed to characterize the cellulases. The cellulases’ CMCase and FPase activities and stabilities were analyzed for optimum temperature and pH. The effect of substrate concentration and kinetic constants Km and Vmax, along with thermodynamic analysis, were determined. The effects of several metals on the activity of the enzyme were observed. The optimal temperatures were found as 40 °C and 50 °C for CMCase and FPase activity, respectively. CMCase activity shows stability at 20 °C-60 °C, FPase shows low thermal stability as its activity starts to decrease after 50 °C. CMCase and FPase both show maximum activity at pH 6, and maintain their stability at pH 6-7. The values of Km and Vmax obtained from Lineweaver and Burk plot for CMCase are 0.648 mM and 12.953 mM/min, and for FPase are 0.975 mM and 41.493 mM/min. The Arrhenius plot was used to calculate activation energy (Ea) as -19 kJ/mol, and enthalpy of reaction (ΔH) as 16.4 kJ/mol, while entropy ΔS -16.4 kJ/mol was obtained from the plot of ln(Vmax/T) versus the inverse of temperature (1/T). Most metals induce enzyme activities, whereas EDTA inhibits enzyme activities. The findings suggest A. niger has remarkable cellulase production potential from grape wastes in static fermentation, at optimum temperature and pH levels for achieving enzyme activity and stability.

Optimal Targeted Temperature Management for Patients with Post-Cardiac Arrest Syndrome.

Background: To prevent hypoxic-ischemic brain damage in patients with post-cardiac arrest syndrome (PCAS), international guidelines have emphasized performing targeted temperature management (TTM). However, the most optimal targeted core temperature and cooling duration reached no consensus to date. This study aimed to clarify the optimal targeted core temperature and cooling duration, selected according to the time interval from collapse to return of spontaneous circulation (ROSC) in patients with PCAS due to cardiac etiology. Methods: Between 2014 and 2020, the targeted core temperature was 34 °C or 35 °C, and the cooling duration was 24 h. If the time interval from collapse to ROSC was within 20 min, we performed the 35 °C targeted core temperature (Group A), and, if not, we performed the 34 °C targeted core temperature (Group B). Between 2009 and 2013, the targeted core temperature was 34 °C, and the cooling duration was 24 or 48 h. If the interval was within 20 min, we performed the 24 h cooling duration (Group C), and, if not, we performed the 48 h cooling duration (Group D). Results: The favorable neurological outcome rates at 30 days following cardiac arrest were 45.7% and 45.5% in Groups A + B and C + D, respectively (p = 0.977). In patients with ROSC within 20 min, the favorable neurological outcome rates at 30 days following cardiac arrest were 75.6% and 86.4% in Groups A and C, respectively (p = 0.315). In patients with ROSC ≥ 21 min, the favorable neurological outcome rates at 30 days following cardiac arrest were 29.3% and 18.2% in Groups B and D, respectively (p = 0.233). Conclusions: Selecting the optimal target core temperature and the cooling duration for TTM, according to the time interval from collapse to ROSC, may be helpful in patients with PCAS due to cardiac etiology.