Concentration Of Mixture Research Articles

Three-Dimensional-Printed Sodium Alginate and k-Carrageenan-Based Scaffolds with Potential Biomedical Applications.

This work reports the development of a marine-derived polysaccharide formulation based on k-Carrageenan and sodium alginate in order to produce a novel scaffold for engineering applications. The viscoelastic properties of the bicomponent inks were assessed via rheological tests prior to 3D printing. Compositions with different weight ratios between the two polymers, without any crosslinker, were subjected to 3D printing for the first time, to the best of our knowledge, and the fabrication parameters were optimized to ensure a controlled architecture. Crosslinking of the 3D-printed scaffolds was performed in the presence of a chloride mixture (CaCl2:KCl = 1:1; v/v) of different concentrations. The efficiency of the crosslinking protocol was evaluated in terms of swelling behavior and mechanical properties. The swelling behavior indicated a decrease in the swelling degree when the concentration of the crosslinking agent was increased. These results are consistent with the nanoindentation measurements and the results of the macro-scale tests. Moreover, morphology analysis was also used to determine the pore size of the samples upon freeze-drying and the uniformity and micro-architectural characteristics of the scaffolds. Overall, the registered results indicated that the bicomponent ink, Alg/kCG = 1:1 may exhibit potential for tissue-engineering applications.

Three-dimensionally printable hollow silica nanoparticles for subambient passive cooling

Abstract Solar reflectance and thermal emissivity are critical benchmarks for evaluating the effectiveness of passive cooling strategies. The integration of three-dimensional (3D) printing techniques with passive cooling materials enables local thermal management of multifaceted objects, offering opportunities for unexplored energy-saving applications. For example, conformal printing of cooling materials can mitigate solar absorption caused by the top metal electrodes in solar cells, thereby improving their efficiency and lifetime. In this study, we report the synthesis of 3D printable hollow silica nanoparticles (HSNPs) designed to induce subambient cooling performance under daylight conditions. HSNPs with diameters of 400–700 nm and silica shell thicknesses of approximately 100 nm were synthesized using an in-situ sol–gel emulsion method. Subsequently, these HSNPs were formulated into printable pastes by carefully selecting the mixture concentration and molecular weight of polyvinylpyrrolidone (PVP). The PVP-linked HSNPs exhibited a solar (0.3–2.5 μm) reflectivity of 0.98 and a thermal (8–13 μm) emissivity of 0.93. In contrast to a single silica nanoparticle (NP), the scattering analysis of a single HSNP revealed a distinctive scattering distribution characterized by amplified backward scattering and suppressed forward scattering. In outdoor daytime experiments, the HSNP-printed sample led to the subambient cooling of a dielectric substrate, surpassing the cooling performance of reference materials such as silica NPs, silver pastes, and commercial white plastics and paints.

Early influences of tamarack (Larix laricina) on black spruce (Picea mariana) and its immediate environment in plantations

Mixed plantations are garnering increased attention due to their potential to provide a broader array of benefits compared to monocultures. Although numerous studies have indicated promising complementarity between black spruce ( Picea mariana) and tamarack ( Larix laricina), few have delved into individual tree growth interactions to thoroughly assess early growth complementarity. We sampled 119 planted black spruce and their immediate environment to quantify and qualify any differences between two conditions in young plantations: mixed tamarack (“mixtures”) and black spruce monocultures (“monocultures”) within young plantations. We investigated the effect of neighbouring under four perspectives: tree competition, microenvironment, foliar nutrients, and soil nutrients. Our results showed increased values for black spruce foliar nitrogen total concentration, soil pH, and canopy closure in mixtures compared to monocultures. Furthermore, black spruce stem volume was increased by 38.1% in mixture compared to monoculture. Black spruce stem volume was negatively affected (86% decrease) by the combined effect of shrubs and non-crop trees under high competition pressure, despite the plantation being mechanically released in 2017. Collectively, our results suggest that black spruce growing in mixtures holds a greater growth potential than black spruce in monocultures.

A Generalised Series Model for the LES of Premixed and Non-Premixed Turbulent Combustion

In this study, the generality and prediction accuracy of a generalised series model for the large eddy simulation of premixed and non-premixed turbulent combustion is explored. The model is based on the Taylor series expansion of the chemical source term in scalar space and implemented into OpenFOAM. The mathematical model does not depend on combustion regimes and has the correct limiting behaviour. The numerical error sources are also outlined and analysed. The model is first applied to a piloted methane/air non-premixed jet flame (Sandia Flame D). The statistical (time-averaged and RMS) results agree well with the experimental measurements, particularly with regard to the mixture fraction, velocity, temperature, and concentrations of major species CH4, CO2, H2O, and O2. However, the concentrations of the intermediates CO and H2 are over-predicted, due to the limitations of the reduced reaction mechanism employed. Then, a Bunsen-piloted flame is simulated. Most of the statistical properties of both the reactive species and progress variables are well reproduced. The only major discrepancy evident is in the temperature, which is probably attributed to the experimental uncertainties of temperature fields in the pilot stream. These findings demonstrate the model’s generality for both a premixed and non-premixed combustion simulation, as well as the accuracy of prediction of reactive species distribution.

Economic and Behavioral Benefits of Using Aqueous Plant-mixture Extracts in Broiler Production with High Stocking Density

The rising demand for white meat has led to an increased reliance on intensive farming systems involving high stocking density that can cause stress on birds, hinder their growth and behavior, and reduce profitability. This necessitates the use of antioxidant growth enhancers to mitigate the impact of stress. In response to this challenge, this study aimed to determine the effectiveness of natural growth promoters compared to antibiotics in alleviating the negative impact of stocking density stress by conducting an experiment using 300 one-day-old Cobb 500 chicks over 35 days. After 7 days of acclimatization, the chicks were weighed, wing-tagged, and divided into five groups with 60 chicks each, divided into three replicates of 20 birds. The groups were categorized as follows: low stocking density (LSD) with 10 birds/m2, high stocking density (HSD) with 18 birds/m2, HSD+AGP feeding diet with 55 ppm/kg feed Bacitracin Methylene Disalicylate (BMD-50; Zoetis Products, Chicago Heights, IL, USA) as antibiotic growth promoter, HSD+LPEM with a low concentration of aqueous plant extracts mixture (LPEM) (8 ml fennel + 8 ml fenugreek + 8 ml thyme/L of drinking water), and HSD+HPEM with a high concentration of aqueous plant extracts mixture (HPEM) (10 ml fennel + 10 ml fenugreek + 10 ml thyme/L of drinking water). The findings revealed that HSD led to a decline in productivity, behavior, and economic efficiency when compared to LSD. AGP improved these aspects but at a lower level than PEM. In conclusion, to ensure the production of antibiotic-free meat, decrease antibiotic resistance, and achieve better behavioral, productive, and economic outcomes, it is proposed to use a combination of fennel, fenugreek, and thyme aqueous extracts in PEM at a concentration of 8 or 10 mL/L in the drinking water. However, for an optimal cost-benefit ratio, it is recommended to utilize PEM at a concentration of 10 mL per liter of the bird's drinking water.

High-throughput 3D microfluidic chip for generation of concentration gradients and mixture combinations.

Concentration gradient generation and mixed combinations of multiple solutions are of great value in the field of biomedical research. However, existing concentration gradient generators for single or two-drug solutions cannot simultaneously achieve multiple concentration gradient formations and mixed solution combinations. Furthermore, the whole system was huge, and required expensive auxiliary equipment, which may lead to complex operations. To address this problem, we devised a novel 3D microchannel network design, which is capable of creating all the desired mixture combinations and concentration gradients of given small amounts of the input solutions. As a proof of concept, the device we presented was verified by both colorimetric and fluorescence detection methods to test the efficiency. This can enable the implementation of one to three solutions with no driving pump and facilitate unique multiple types of more concentration gradients and mixture combinations in a single operation. We envision that this will be a promising candidate for the development of simplified methods for screening of the appropriate concentration and combination, such as various drug screening applications.

Исследование зависимости температуры самовоспламенения от концентрации паров горючей жидкости

Purpose. The currently used methodology for determining flammable liquid self-ignition temperature, which is well-known as the “drop method”, makes it impossible to obtain the dependence of self-ignition temperature on flammable liquid concentration that corresponds to theoretical concepts. It is related to the fact that while conducting experiments a flammable liquid is injected into the neck of an open heated vessel. The preliminary calculation of the required quantity of flammable liquid for creating its given concentration does not take into account the substance loss when it is injected into the reaction vessel. The main aim of the research is to improve the methodology for determining flammable liquid self-ignition temperature depending on the concentration of its vapors. Methods. To study the relationship between the volume of flammable liquid injected into the neck of the reaction vessel heated to a certain temperature and self-ignition temperature of this liquid the method of experimental data analysis was used. The experimental results were obtained with the help of the experimental method that involved injection of different volumes of flammable liquid and then recording flame presence or absence. Findings. A relationship was established between the fuel concentration in the vapor-air mixture and the volume of the injected sample. The methodology for determining the flammable liquid self-ignition temperature was corrected. Research application field. The results can be used in determining flammable liquids self-ignition temperature of various chemical composition, as well as in the educational process when students carry out a laboratory work on determining a flammable liquid self-ignition temperature depending on its concentration. Conclusions. The findings of the research allowed the authors to draw the following conclusions: 1) in the methodology for determining a flammable liquid self-ignition temperature when calculating the volume of the injected sample to create the required concentration of fuel in the vessel, the flammable liquid losses occurring on its injection into a heated reaction vessel were not taken into account. It is recommended to use a correction factor of 2 to take into consideration losses in calculation formulas. 2) to equally distribute the concentrations of the used fuel on the graph of the dependence under study within the lower and upper flammability limits, to calculate the volume of a flammable liquid, fuel concentration must be preset as follows: ϕ1 = 1,2ϕн, ϕ2 = ϕстех, ϕ3 = 1,8ϕстех, ϕ4 = 0,8ϕв. 3) the methodology for determining the self-ignition temperature of a flammable liquid is also valid in case of using high molecular weight aliphatic (non-cyclic) alcohols, for example, butanol, pentanol, hexanol.

Валидирование разработанной методики определения карбамазепина в сыворотке крови и моче методом высокоэффективной жидкостной хроматографии с диодно-матричным детектированием с применением абсолютной градуировки

For patients undergoing carbamazepine treatment, measuring its concentration in serum and urine may be appropriate to guide treatment. Objective. To validate the developed technique for the quantitative determination of carbamazepine in blood serum and urine. Materials and methods. In the work, biological fluids (blood serum and urine) were used as research objects. Quantitative determination of carbamazepine was carried out in the concentration range from 0,50 to 50,0 mcg/ml on a high-performance liquid chromatograph with diode-matrix detection (Agilent Technologies 1200) by absolute calibration method. To assess linearity, calibration graphs were constructed and the concentrations of the model mixtures were recalculated. The correctness and precision of the developed methodology was determined on the basis of sample analysis data. Results of the study and their discussion. The calibration dependences for blood serum and urine in the range of carbamazepine concentrations of 0,5 – 50,0 mcg/ml are linear. Reverse recalculation of concentrations according to the calibration schedule showed that the deviations of carbamazepine concentrations from the actual values did not exceed 15%. The limit of quantification was 0,5 mcg/ml. At validation of the method, the calculated values of the relative standard deviation do not exceed 6%, relative error – 10,2%. Specificity of the method in relation to carbamazepine was confirmed by the absence of peaks interfering with the determination of chromatograms relative to «blank» samples. Conclusion. The obtained results showed that the method of determination is sensitive, accurate, provides analytical range of measurement from 0,5 to 50,0 mcg/ml with satisfactory expressiveness of work. The technique provides a practical solution for therapeutic monitoring of carbamazepine content, determination of its concentration in forensic chemical practice.

Dietary supplementation of Chinese herbal medicines enhances the immune response and resistance of rainbow trout (Oncorhynchus mykiss) to infectious hematopoietic necrosis virus.

Rainbow trout is a widely farmed economical cold-water fish worldwide, but the prevalence of infectious hematopoietic necrosis virus (IHNV) presents a severe risk to the aquaculture industry, resulting in high mortality and huge economic losses. In this study, the impacts of different concentrations (0, 10, 20, and 30 g/kg) of Chinese herbal medicine mixture (CHMM) on the immune response and resistance of rainbow trout to IHNV infection were evaluated. The results show that CHMM noticeably increased (P < 0.05) T-SOD, CAT, AST, ALT, ACP, and AKP activities and decreased MDA content. NF-κB, TNF-α, IFN-β, IL-1β, JAK1, HSP70, and HSP90 expressions were significantly upregulated (P < 0.05) in all CHMMs, while SOCS2 expression was downregulated (P < 0.05). Following infection with IHNV, feeding rainbow trout with varying amounts of CHMM resulted in noticeably increased (P < 0.05) T-SOD, ACP, and AKP activities and significantly decreased (P < 0.05) MDA content and AST and ALT activities. TNF-α, IFN-β, IL-1β, HSP70, and HSP90 expressions were significantly upregulated (P < 0.05) in all CHMMs, while the expressions of JAK1 and SOCS2 were downregulated. The expression level of the IHNV G protein gene at a dosage of 20 g/kg was notably lower than that of the other CHMM feeding groups. This study provides a solid scientific basis for promoting CHMM as an immunostimulant for boosting antiviral immunity in rainbow trout.

Thermal evolution of a polymer-nanoparticle binary mixture.

We experimentally probe the microscopic variations in a model polymer-nanoparticle (NP) binary mixture (mixture of polybutadiene and clay nanoplatelets) across a thermal evolution path for which Tevolution > Tg(polymer). The evolution of the NP dispersion, NP crystallinity, polymer chain-NP interface, and nature of polymer chain-NP interaction are mapped for a spectrum of temperatures and NP concentrations constrained by experiments. Multiple pieces of evidence indicate that thermal evolution does not influence the nature of interparticle dispersion and is also independent of NP concentration in the binary mixture. However, the NP crystalline order significantly reduces across the thermal evolution path. Thermal evolution induces a transition of a sharp polymer chain-NP interface to a diffuse interfacial layer. In contrast, an already diffuse polymer-NP interface existing in the binary mixture due to particle crowding at high NP concentrations undergoes no significant change in its nature across the evolution path. At all particle concentrations, thermal evolution changes the dominant interaction from polymer chain-polymer chain to polymer chain-NP. These insights aid in explaining the molecular origins of unique and anomalous behaviors shown by polymer-nanoparticle binary mixtures while undergoing thermal evolution.

Evaluation of mixtures of flavor chemicals in a 90-day nose-only exposures in sprague-dawley rats.

One of the challenges to using some flavor chemicals in aerosol products is the lack of route of administration specific toxicology data. Flavor chemicals (88) were divided into four different flavor mixtures based upon chemical compatibility and evaluated in 2-week dose-range-finding and subsequent 90-day nose-only rodent inhalation studies (OECD 413 and GLP compliant). Sprague-Dawley rats were exposed to vehicle control or one of three increasing concentrations of each flavor mixture. In the dose-range-range-finding studies, exposure to flavor mixture four resulted in adverse nasal histopathology in female rats at the high dose, resulting in this flavor mixture not being evaluated in a 90-day study. In the 90-day studies daily exposures to the three flavor mixtures did not induce biologically meaningful adverse effects (food consumption, body weights, respiratory physiology, serum chemistry, hematology, coagulation, urinalysis, bronchoalveolar lavage fluid analysis and terminal organ weights). All histopathology findings were observed in both vehicle control and flavor mixture exposed animals, with similar incidences and/or severities, and therefore were not considered flavor mixture related. Based on the absence of adverse effects, the no-observed-adverse-effect concentration for each 90-day inhalation study was the highest dose tested, 2.5mg/L of the aerosolized high dose of the three flavor mixtures.

Modeling thermal-technical parameters of a solar pond using COMSOL multiphysics

The article presents the experiments of scientific study of the temperature changes of the pond layers at the given solar radiation values inside the solar pond device modeled using Comsol Multiphysics. The developed model of the solar pond with simplified geometry dimensions changes the sign of the experimental calculation in a positive direction, which helps to study and optimize the energy accumulation process. This research shows that computer modeling can be used to study and optimize the solar pond energy storage process. In addition, the results of this modeling can be used to improve the solar pond device and develop its new technologies. The models obtained from the 3D study of the process using the Comsol multiphysics program are analogs of the three-dimensional cross section in the vertical part of the solar pool. It has been shown that the bottom energy storage layer of the solar pool rises up to 60 ℃ when the concentration of the salt water mixture in the solar pool device varies around 25-30% and the energy storage reaches its maximum value when the solar radiation reaches its maximum value.

Antioxidant interaction between α-tocopherol and γ-oryzanol in HepG2 cells.

Minor constituents exhibit certain antioxidant interactions in vitro, and the effects in different media are different. However, it is not clear whether there are antioxidant interactions in cells after digestion and absorption. We utilized the cellular antioxidant evaluation model in HepG2 cells to study the antioxidant interaction between α-tocopherol and γ-oryzanol, and the interaction mechanism of a binary mixture was also illustrated. A cellular antioxidant assay (CAA) model and a combined index (CI) method were firstly used to explore the antioxidant activity and interaction of the binary mixture in HepG2 cells. The CAA value was positively correlated with the single addition concentration, while the results displayed a biphasic tendency with increasing concentrations of the binary mixture. The combination of TO11 (1 μg mL-1 α-tocopherol and 10 μg mL-1 γ-oryzanol) showed the greatest antioxidant activity and synergistic effect, and the maximum CAA value reached up to 94.84 ± 4.2. Then the mechanism of the synergistic antioxidant effect of the binary mixture was explained from three aspects including cellular uptake, intracellular reactive oxygen species (ROS) level and endogenous enzyme activity. The results demonstrated that the antioxidant interaction of the binary mixture in cells was related to cellular uptake of minor constituents, and the combination of TO11 exerted a synergistic effect by scavenging ROS and up-regulating glutathione peroxidase (GSH-Px) activity, resulting in the strongest cellular antioxidant activity. This study throws light on the nature of antioxidant interaction between minor constituents, which may contribute to the development of related functional foods and rational dietary collocation.

НАБУХАНИЕ ПОЛИУРЕТАНОВЫХ ПЛЕНОК НА ОСНОВЕ АМИНОЭФИРОВ БОРНОЙ И ОРТОФОСФОРНОЙ КИСЛОТ В ВОДНЫХ РАСТВОРАХ СПИРТОВ

In this work we have carried out studies to determine the sorption capacity (swelling) of polymer polyurethane films based on amino esters of boric and orthophosphoric acids in pure components (water, isopropyl and ethyl alcohols) and water-alcohol mixtures (isopropanol-water, ethanol-water) at temperatures of 22, 40 and 60 °С. On the basis of the data on the sorption capacity of components through polymer films a preliminary assessment of the prospects of using the investigated polymers as a selective layer of pervaporation membranes is made. The changes in the volume-mass concentration of low-molecular-weight components in polymer films depending on the solvent concentration in the initial mixture and the temperature of the process have been determined experimentally. The obtained data are necessary for creating a mathematical model of the pervaporation separation process. The paper describes the developed methodology for the fabrication of polymer films based on amino esters of orthophosphoric and boronic acids. Hyperbranched polyols with high solubility and low characteristic viscosities were used as crosslinking agents in the synthesis of the studied polymers Experimental studies for water-alcohol mixtures were carried out in a wide range of alcohol concentrations (0-99 wt.%). The swelling dynamics of polymer films in water-alcohol mixtures and individual components were measured. For all films, a tendency of decreasing volume-mass concentration with increasing process temperature in isopropyl alcohol and water can be seen, but in ethyl alcohol the volume-mass concentration increases with exceeding the process temperature.

ПЕРВАПОРАЦИОННОЕ РАЗДЕЛЕНИЕ ВОДНО-СПИРТОВЫХ СМЕСЕЙ НА ПОЛИУРЕТАНОВЫХ МЕМБРАНАХ НА ОСНОВЕ АМИНОЭФИРОВ БОРНОЙ И ОРТОФОСФОРНОЙ КИСЛОТ: ЭКСПЕРИМЕНТ И МОДЕЛИРОВАНИЕ

In this work, the separation characteristics of a selective layer of pervaporation membranes made of polyurethanes based on amino esters of orthophosphoric acid (AEPA) and amino esters of boric acid (AEBA) were studied during the dehydration of azeotropic water-alcohol mixtures. Polymer compositions of polyurethanes based on various compositions of AEPA and AEBA were studied in order to identify the best options. For polyurethane based on AEPA, moles of orthophosphoric acid influenced the composition of the polymer composition; for polyurethane based on AEBA, the effect of modifiers (bulk adducts of diphenylolpropane diglycidyl ether and copper chloride) was measured. A technology has been developed for the production of polymer pervaporation membranes with a selective layer of restrictive polyurethanes. Experimental studies on the pervaporation dehydration of isopropanol/water and ethanol/water mixtures in various alcohol concentrations (50-99 wt%) and various feedstock temperatures are presented. Obtains permeate flux and separation factor results for membrane confinement when separating confinement mixtures. It has been determined that an increase in the moles of orthophosphoric acid in the composition of the polymer composition AEPA and the use of modifiers in the synthesis of the polymer composition AEBA improve the separation characteristics of pervaporation membranes. It was revealed that when the process temperature increases by 20 °C, the permeate flow through the membrane increases, for example, for polyurethane based on AEPA-5-PEG, the value increases by 2 times, with a practically unchanged separation coefficient. Based on the pervaporation separation index data, promising polymer compositions were selected. The results of the data obtained are compared with the studies of other authors; the membranes we use have high values of permeate flux and separation coefficient, which are consistent with the values for any membranes from the open literature. Based on the concept of dissolution-diffusion, the process of pervaporation of isopropanol/water and ethanol/water mixtures through polymer membranes was simulated. The given calculation system is cyclic, and the results of calculating the permeate flow and separation coefficient using this model are in good agreement with the experimental data obtained.

Pubertal origin of growth retardation in inborn errors of protein metabolism: A longitudinal cohort study

ObjectivesInherited amino-acid metabolism disorders (IAAMDs) require lifelong protein-restricted diet. We aimed to investigate: 1/ whether IAAMDs was associated with growth, pubertal, bone mineral apparent density (BMAD) or body composition impairments; 2/ associations linking height, amino-acid mixture (AAM), plasma amino-acids and IGF1 concentrations. DesignRetrospective longitudinal study of 213 patients with neonatal-onset urea cycle disorders (UCD,n = 77), organic aciduria (OA,n = 89), maple syrup urine disease (MSUD,n = 34), or tyrosinaemia type 1 (n = 13). MethodsWe collected growth parameters, pubertal status, BMAD, body composition, protein-intake, and IGF1 throughout growth. ResultsOverall final height (n = 69) was below target height (TH): −0.9(1.4) vs. -0.1(0.9) SD, p < 0.001. Final height was ≤ TH-2SD in 12 (21%) patients. Height ≤ − 2SD was more frequent during puberty than during early-infancy and pre-puberty: 23.5% vs. 6.9%, p = 0.002; and vs. 10.7%, p < 0.001. Pubertal delay was frequent (26.7%). Height (SD) was positively associated with isoleucine concentration: β, 0.008; 95%CI, 0.003 to 0.012; p = 0.001. In the pubertal subgroup, height (SD) was lower in patients with vs. without AAM supplementation: −1.22 (1.40) vs. -0.63 (1.46) (p = 0.02). In OA, height and median (IQR) isoleucine and valine concentrations(μmol/L) during puberty were lower in patients with vs. without AAM supplementation: −1.75 (1.30) vs. −0.33 (1.55) SD, p < 0.001; and 40 (23) vs. 60 (25) (p = 0.02) and 138 (92) vs. 191 (63) (p = 0.01), respectively. No correlation was found with IGF1. Lean-mass index was lower than fat-mass index: −2.03 (1.15) vs. -0.44 (0.89), p < 0.001. ConclusionsIn IAAMDs, growth retardation worsened during puberty which was delayed in all disease subgroups. Height seems linked to the disease, AAM composition and lower isoleucine concentration, independently of the GH-IGF1 pathway. We recommend close monitoring of diet during puberty.

Dilution-controlled deposition of mixtures of a synthetic polycation and a natural origin polyelectrolyte with anionic surfactants on negatively charged surfaces

The cosmetics industry is constantly seeking sustainable and environmentally friendly ingredients for hair care formulations to replace those traditionally derived from the petrochemical industry. In this context, the substitution of traditional cationic polyelectrolytes, such as poly(diallyldimethylammonium chloride, PDADMAC), by others of natural origin, such as chitosan, is a key challenge to achieve new formulations with a higher degree of naturality and more environmentally friendly without compromising product efficacy. This work investigates the effect of dilution on the phase separation of concentrated binary mixtures of two anionic surfactants (sodium laureth sulfate, SLES, and sodium dodecyl sulfate, SDS) with PDADMAC or chitosan. PDADMAC is a polycation of petrochemical origin, whereas chitosan is obtained from natural resources. Also, how this phase separation affects the formation of conditioning deposits on surfaces that mimic the charge and wettability of damaged hair fibers has been studied. The results show that for polymers of similar molecular weight, the substitution of PDADMAC by a highly charged chitosan is a promising alternative. The deposition is greatly enhanced for model wash formulations containing chitosan after minimal dilution. The results obtained here may pave the way to an important line of research toward improving the sustainability profile of hair care formulations without compromising consumer satisfaction.

Comprehensive multi-gas study by means of fiber-enhanced Raman spectroscopy for the investigation of nitrogen cycle processes.

The extensive use of synthetic fertilizers has led to a considerable increase in reactive nitrogen input into agricultural and natural systems, resulting in negative effects in multiple ecosystems, the so-called nitrogen cascade. Since the global population relies on fertilization for food production, synthetic fertilizer use needs to be optimized by balancing crop yield and reactive nitrogen losses. Fiber-enhanced Raman spectroscopy (FERS) is introduced as a unique method for the simultaneous quantification of multiple gases to the study processes related to the nitrogen cycle. By monitoring changes in the headspace gas concentrations, processes such as denitrification, nitrification, respiration, and nitrogen fixation, as well as fertilizer addition were studied. The differences in concentration between the ambient and prepared process samples were evident in the Raman spectra, allowing for differentiation of process-specific spectra. Gas mixture concentrations were quantified within a range of low ppm to 100% for the gases N2, O2, CO2, N2O, and NH3. Compositional changes were attributed to processes of the nitrogen cycle. With help of multivariate curve resolution, it was possible to quantify N2O and CO2 simultaneously. The impact of fertilizers on N-cycle processes in soil was simulated and analyzed for identifying active processes. Thus, FERS was proven to be a suitable technique to optimize fertilizer composition and to quantify N2O and NH3 emissions, all with a single device and without further sample preparation.

Development of a cap liner composite film incorporating zinc oxide, celite, and zeolite for kimchi-storing bottles to absorb volatile sulfur compounds

Bottle cap liner films (“ZnO[celite]–zeolite film”) that absorb volatile sulfur compounds from kimchi were developed for kimchi-packaging plastic bottles using zinc oxide (ZnO) in celite (ZnO[celite]), zeolite, and low-density polyethylene (LDPE). The ZnO[celite] concentration-dependent deodorizing effect of the films and their physicochemical properties were evaluated. When the ZnO[celite] and zeolite mixture concentration in the film was 18% (w/w), the concentration of allyl methyl disulfide absorbed in the film increased by 98% compared with when this mixture was not used. Addition of ZnO[celite] and zeolite into the LDPE films altered their surface and cross-sectional morphologies and yellowness, but did not change their thermal stability, thermal properties, oxygen barrier, or tensile properties. These results suggest that the bottle cap liner prepared using the ZnO[celite]–zeolite film can effectively absorb volatile sulfur compounds and may be used as a liner for kimchi-containing bottles, replacing the conventional LDPE liner.

Single and mixture toxicity of cadmium and copper to swim bladder in early life stages of Japanese medaka (Oryzias latipes).

Toxicity observed in aquatic ecosystems often cannot be explained by the action of a single pollutant. Likewise, evaluation standards formulated by a single effect cannot truly reflect the environmental quality requirements. The study of mixtures is needed to provide environmental relevance and knowledge of combined toxicity. In this study, the embryos of Japanese medaka (Oryzias latipes) were treated with individual and binary mixture of copper (Cu) and cadmium (Cd) until 12days post-fertilization (dpf). Hatching, mortality, development, histology and gene expression were assessed. Our results showed that the highest concentration mixture of Cd (10mg/L) and Cu (1mg/L) affected survival, hatching time and hatching success. Occurrence of uninflated swim bladder was the highest (value) with exposure to 10mg/L Cd. Swim bladder was commonly over-inflated in a mixture (0.1mg/L Cd + 1.0mg/L Cu) exposure. Individuals exposed to the mixture (0.1 Cd + 1.0 Cu mg/L) showed up to a 7.69% increase in swim bladder area compared to the control group. The mixtures containing 0.1 or 10mg/L Cd, each with 1.0mg/L Cu resulted in significantly increased of Pbx1b expression, higher than any Cd or Cu alone (p < 0.01). In the co-exposure group (0.1/10 Cd + 1.0 Cu mg/L), Pbx1b expression was found at 12dpf but not 7dpf in controls. Higher concentrations of Cd may progressively reduce Pbx1b expression, potentially explaining why 75% of individuals in the 10mg/L Cd group failed to inflate their swim bladders. Additionally, the swim bladder proved to be a valuable bio-indicator for biological evaluation.