Concentration Of Malonic Acid Research Articles

Destabilisation of water-in-crude oil emulsions using inorganic acids: The role of counter-ions and malonic acid

The quantitative role of pH with regards to the stabilisation of water-in-crude oil emulsions is not well established in literature. In this work, we report an observation wherein the prevention of stable emulsion formation occurs abruptly at a specific pH when water-in-crude oil emulsions are generated using inorganic acids (HCl, H2SO4 and HNO3) and crude oils with comparatively low asphaltene contents. Subsequent analysis of the aqueous phase indicated the emulsion prevention coincided with both increasing partitioning of metal cations and total organic content (TOC). Analysis of the TOC highlighted the presence of elevated concentrations of malonic acid and its derivatives which emphasises its importance in the demulsification process. The effect of elevated concentrations of malonic acid was investigated and determined to increase the rate of emulsion destabilisation when initially dissolved in the aqueous phase. Therefore, the role of malonic acid on emulsion stability is hypothesised to be due to its partitioning into the aqueous phase as a counter-ion to dissolved metals. These results highlight malonic acid as being a key chemical species to consider when assessing the stability of a water in crude oil emulsion.

Investigation of sustainable reactive distillation process to produce malonic acid from dimethyl malonate

The new energy battery is currently a hot research topic, leading to an increase in the demand for malonic acid (MA) as a raw material. The objective of the present work is to find a potential reactive distillation (RD) process to solve the problem of low conversion and high energy consumption in hydrolytic system. In the meantime, the RD technology still faces the problem of how to distribute water in the RD column. Aiming at the problem, four different RD processes are proposed: RD combined water separation process (RDWS), RD combined with MA concentration process (RDMC), RD combined methanol separation process (RDMS), and single RD process (SRD). Beforehand, reaction kinetic of dimethyl malonate (DM) hydrolysis was investigated using the ion exchange resin catalysts, and the developed RD model was verified via pilot-scale RD experiments. Finally, the proposed RD process is analyzed from the aspects of economic and environmental and compared with the traditional reaction + distillation (R + D) process. Consequently, the proposed SRD process is a better economy-saving and environment-friendly technology, and has certain directive significance for the industrial production of MA.

Aspartate α-decarboxylase a new therapeutic target in the fight against Helicobacter pylori infection.

Effective eradication therapy for Helicobacter pylori is a worldwide demand. Aspartate α-decarboxylase (ADC) was reported as a drug target in H. pylori, in an in silico study, with malonic acid (MA) as its inhibitor. We evaluated eradicating H. pylori infection through ADC inhibition and the possibility of resistance development. MA binding to ADC was modeled via molecular docking. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of MA were determined against H. pylori ATCC 43504, and a clinical H. pylori isolate. To confirm selective ADC inhibition, we redetermined the MIC in the presence of products of the inhibited enzymatic pathway: β-alanine and pantothenate. HPLC was used to assay the enzymatic activity of H. pylori 6x-his tagged ADC in the presence of different MA concentrations. H. pylori strains were serially exposed to MA for 14 passages, and the MICs were determined. Cytotoxicity in different cell lines was tested. The efficiency of ADC inhibition in treating H. pylori infections was evaluated using a Sprague-Dawley (SD) rat infection model. MA spectrum of activity was determined in different pathogens. MA binds to H. pylori ADC active site with a good docking score. The MIC of MA against H. pylori ranged from 0.5 to 0.75 mg/mL with MBC of 1.5 mg/mL. Increasing β-alanine and pantothenate concentrations proportionally increased MA MIC. The 6x-his tagged ADC activity decreased by increasing MA concentration. No resistance to ADC inhibition was recorded after 14 passages; MA lacked cytotoxicity in all tested cell lines. ADC inhibition effectively eradicated H. pylori infection in SD rats. MA had MIC between 0.625 to 1.25 mg/mL against the tested bacterial pathogens. In conclusion, ADC is a promising target for effectively eradicating H. pylori infection that is not affected by resistance development, besides being of broad-spectrum presence in different pathogens. MA provides a lead molecule for the development of an anti-helicobacter ADC inhibitor. This provides hope for saving the lives of those at high risk of infection with the carcinogenic H. pylori.

Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

The hydrometallurgical method of copper leaching from scrap electronics is commonly undertaken using pulverized printed circuit boards. Though studies on the use of organic acids like citric and oxalic acids for copper removal are well documented, those on the use of malonic acid are rare. Herein, we report on the investigation of the efficiencies of mixtures of malonic acid and hydrogen peroxide for copper leaching from unpulverized scrap PCB by the Box-Behnken design and the theoretical determination of the most stable copper-malonic acid complex. The average copper content in each unpulverized printed circuit board was found to be (0.84 ± 0.13) mg/g following aqua-regia digestion and atomic absorption spectrophotometry measurement. The conditions at which the highest leaching efficiency of 51.3% was obtained were a malonic acid concentration of 0.5 M, a hydrogen peroxide concentration of 1.0 M, and a contact time of 75 min. The contact time was the most significant individual parameter that influenced the efficiency of copper leached with a p-value of 0.001. Theoretical calculations show that malonic acid prefers to coordinate with copper in a 2:1 malonic acid: copper ratio. This study shows that appreciable amounts of copper can be leached from the minimally processed unpulverized printed circuit board.

Effects of cadmium and flooding on the formation of iron plaques, the rhizosphere bacterial community structure, and root exudates in Kandelia obovata seedlings

In the rhizosphere, plant root exudates (REs) serve as a bridge between plant and soil functional microorganisms, which play a key role in the redox cycle of iron (Fe). This study examined the effects of periodic flooding and cadmium (Cd) on plant REs, the rhizosphere bacterial community structure, and the formation of root Fe plaques in the typical mangrove plant Kandelia obovata, as well as the relationship between REs and Fe redox cycling bacteria. Based on two-way analysis of variance, flooding and Cd had a considerable effect on the REs of K. obovata. DOC, NH4+-N, NO3−-N, dissolved inorganic phosphorus, acetic acid, and malonic acid concentrations in REs of K. obovata increased considerably with the increase of Cd concentration under 5 and 10 h flooding conditions. Fe plaque development in the plant root was stimulated by flooding and Cd, although flooding was more effective. After Cd treatment, the ways in which Fe-oxidizing bacteria (FeOB) and Fe-reducing bacteria (FeRB) were enriched in the rhizosphere and rhizoplane of plants were different. Thiobacillus and Sideroxydans (dominant FeOB) were more abundant in the plant rhizosphere, whereas Acinetobacter (dominant FeRB) was more abundant in the rhizoplane. Cd considerably decreased the relative abundance of unclassified_f_Gallionellaceae in the rhizosphere and rhizoplane but dramatically enhanced the relative abundance of Thiobacillus, Shewanella, and unclassified_f_Geobacteraceae. Unclassified_f_Geobacteraceae and Thiobacillus exhibited substantial positive correlations with citric acid and DOC in REs in the rhizosphere and rhizoplane but strong negative correlations with Sideroxydans. The findings indicate that Cd and flooding treatments may play a role in the production and breakdown of Fe plaque in K. obovata roots by affecting the relative abundance of Fe redox cycling bacteria in the rhizosphere and rhizoplane.

Inhibition of Intracellular Succinate Dehydrogenase of the Bacillus subtilis Bacterium as a Criterion for the Involvement of an Enzyme in the Reduction of Chloride Iodonitrotetrazolium, an Indicator of Cell Viability

After diffusion of the tetrazolium salt to membrane reducing agents of the Bacillus subtilis cells, the reduction rate is shown to be affected by the state of the succinate dehydrogenase enzyme. Based on the dependence of the initial rate of iodonitrotetrazolium chloride reduction by the cellular components of Bacillus subtilis on the concentration of malonic acid, the competitive inhibition constant for the intracellular succinate dehydrogenase enzyme is quantitatively determined.

Highly Efficient Adsorption of Cd(II) onto Carboxylated Camelthorn Biomass: Applicability of Three-Parameter Isotherm Models, Kinetics, and Mechanism

A series of malonic acid treated camelthorn (MATC) sorbents were produced via the reaction of camelthorn biomass with malonic acid, and factors affecting the extent of modification were investigated, including malonic acid concentration, dehydration time and temperature. The optimum sorbent, by carboxylic acid content, was subsequently characterised for surface charge behaviour (pHPZC), surface chemical functionalities (FTIR), morphological structure (SEM), and available surface area. The sorbent was subsequently utilised for adsorption of Cd(II) ions from aqueous media, and parameters influencing adsorption at 30 °C, such as sorbent dose, initial solution pH, exposure time, metal concentration, were investigated. Isothermal analyses were performed using eight models, including two and three parameter equations, with appropriateness of fit assessed via non-linear regression analysis. The adsorption data indicated that the Langmuir model gives the most appropriate fit to experimental curves, with the models ordered as Langmuir > Hill > Toth > Sips > Jossens > Khan > Redlich-Peterson > Freundlich. The highest uptake (qmax) of 582.6 mg g−1 was determined at pH 6. The Freundlich constants, KF and n, at 30 °C were found to be 24.94 mg g−1 and 2.33, respectively. The value of n (2.33), being in the range 0–10, indicates that adsorption of Cd(II) ions onto malonic acid treated camelthorn biomass is favourable. Evaluation of a series of kinetic models, allowed elucidation of the adsorption mechanism, as a pseudo-second order model gave the most appropriate fit, indicating that chemisorption processes are involved. Cd(II) ions adsorption onto MATC is enhanced by a higher level of active surface sites but was show to be independent of surface area. The work presented here indicates that this sorbent offers effective adsorption potential for Cd(II) ions from water, with potential in wastewater processing.

The Briggs–Rauscher Reaction: A Demonstration of Sequential Spatiotemporal Patterns

The Briggs–Rauscher reaction is a popular demonstration to illustrate chemical oscillations in laboratories, classrooms, and public seminars because of its simplicity and visual appeal. Here, we adapt the Briggs–Rauscher reaction to present reaction–diffusion–convection patterns in the undergraduate general or physical chemistry laboratory. By maintaining the ratio between malonic acid and potassium iodate concentrations as 0.2 in an uncovered Petri dish, sequential patterns (transient dendritic patterns and rotating dendritic patterns) can be observed, which are induced by the interaction of reaction, diffusion, and convection. This beautiful demonstration captures students’ attention and inspires reflection and discussion about similar phenomena in nature as well as the wealth of behaviors in systems far from equilibrium.

Preparation of Chitosan Hydrogel with Malonic Acid Crosslinker as Soil Conditioner for Soybean Plant (Glycine max L. merril)

AbstractThis research is on the manufacture of chitosan hydrogel crosslinked with malonic acid to be used as a soil conditioner for soybean plant (glycine max L. merrill). The aim of the study is to determine the effect of chitosan composition on malonic acid and the characteristics of hydrogel, and the effect of hydrogel as soil conditioner—its physical and chemical properties and role in soybean plant growth. Hydrogel of chitosan crosslinked malonic acid is carried out through a crosslinking chemical method. The increase in chitosan and malonic acid concentration can increase the swelling degree of hydrogel by 285.32%. Characterization is done using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR analysis shows changes in the specific absorption between chitosan and chitosan crosslinked malonic acid that occurs in the area of wave number 1080 cm−1 (C─O). SEM analysis shows that the increase in chitosan composition and malonic acid concentration causes the surface structure to be rough, hollow, and irregular. The use of hydrogel on soil conditions of soybean plants at 75th day measurements which give the most significant positive response is chitosan: malonic acid (2.5 g: 2.5%). Moisture value, soil temperature, C‐organic content, absorbed potassium level, and cation exchange capacity (CEC) content are 50%, 27–30 °C, 2%, 20.54 ppm, and 17.74 meq/100 g, respectively. In addition, the effect of hydrogel use on soybean plants result in the plant reaching a maximum height of 93 cm on the 75th day. The chitosan–malonic acid hydrogel has potential as soil conditioner.

Sea spray aerosol formation: Results on the role of different parameters and organic concentrations from bubble bursting experiments

Submicron sea spray aerosol (SSA) particles play an essential role in atmospheric chemical processes and the Earth’s radiative balance. In this study, different combinations of NaCl, MgSO4, malonic acid (MA), d-fructose and sodium malonate were used to explore the effect of MA on submicron SSA generation. SSA particles were produced at room temperature by bubble bursting from an adjustable home-built SSA generator with sintered glass filters. We found that MA could promote the generation of SSA particles and make the geometric mean diameter (GMD) to decrease for MA concentrations ranging between 8 and 32 mM and then, to increase for MA concentrations in the range of 64–160 mM. d-fructose could improve the generation of SSA with increasing GMD. Interestingly, sodium malonate could significantly enhance the production of SSA, with the change of morphology. Besides, different parameters including flow rate, underwater depth, pore size and size span of sintered glass filter and salinity of water were tested to obtain the characterization of our self-made adjustable SSA generator. Three modes could be found among different SSA generation methods, and they exhibited an obvious accumulation mode around 100 nm. The SSA generation under different conditions was compared with oceanic measurements from the literature, which showed that the sintered glass filter has advantages in generating submicron SSA from film drops.

Metabolite profiles discriminate between acl injured cases and uninjured controls within the first year following injury and surgery

Purpose: Early biological changes at the metabolite level following acute traumatic knee joint injury may influence the initiation and progression of post-traumatic osteoarthritis. The overall objective of this study was to define the metabolite profile in young and physically active military service members following anterior cruciate ligament (ACL) rupture in comparison to uninjured matched controls. Methods: As part of a larger prospective cohort study we collected biospecimen samples (e.g., serum, plasma, etc.) at the time of ACL injury, the time of ACL reconstruction surgery, and at 6 months and 12 months post-surgery in ACL injured cases and at comparable time points in uninjured controls matched for sex, age (±2 years), height (±5.08 cm), and weight (±6.80 kg). We examined plasma samples from the first 30 ACL injured cases and 30 uninjured matched controls that had complete follow-up at all time points. All sample preparation was completed in batches of 20 samples to maintain sample extraction and derivatization stability prior to comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) analysis. Plasma samples at each time point were analyzed using the GC×GC-TOFMS method to identify important metabolites that might discriminate between ACL injured cases and uninjured matched controls. Fisher-Ratios were calculated as the group-to-group variance of the detected signal divided by the sum of the within-group variance of the signal and compared between groups at each time point to identify potentially important metabolites. Quantitative analysis for Fisher-Ratio selected metabolites was obtained via PARAFAC, a chemometric deconvolution algorithm, to obtain the metabolite peak areas. Testing for statistical significance of the concentration ratios using the peak areas for the key metabolites was based on t-tests with p-values using Microsoft Excel 365 ProPlus. Following metabolite quantification, the top 10 metabolites identified were carried forward and examined using principal component analysis on metabolite peak areas using PLS Toolbox 8.6. Results: Among the 30 ACL injured cases, 18 were males (60%) and the average age, height and weight was 19.35±1.22 years, 175.98±37.36 cm, and 78.93±16.95 kg. Uninjured controls for each case were matched for sex, age (±2 years), height (±5.08 cm), and weight (±6.80 kg). The top 10 metabolites identified via Fisher-Ratio analyses are presented in the table. Eight of the 10 metabolites were significantly different between ACL injured cases and uninjured matched controls at the time of injury, five were different at the time of ACL reconstruction surgery, six were different 6 months post-surgery, and eight were different 12 months-post surgery. L-methionine, Glyoxylic acid, and Malonic acid concentrations were significantly lower across all time points in ACL injured cases compared to uninjured matched controls. L-Lysine concentrations were significantly higher in ACL injured cases across all time points. Succinic acid concentrations were significantly higher in ACL injured cases at the time of injury and at 6 months and 12 months post-surgery. Arachidonic acid concentrations were significantly higher in ACL injured cases at the time of injury, the time of surgery, and 12 months post-surgery. The total percentage of explained variance by the first two principal components was 55.0% at the time of ACL injury, 58.0% at the time of ACL reconstruction surgery, 59.8% at 6 months post-surgery, and 56.6% 12 months post-surgery. As demonstrated in the figure, modest separation was observed between ACL injured cases and uninjured matched controls at the first two time points (time of injury and surgery) and notable separation was observed at the latter two time points (6 months and 12 months post-surgery). The proportion of cumulative explained variance with the first four principal components improved to 78.2% to 84.5% across all time points. Conclusions: Plasma concentrations for several metabolites appear to differentiate between ACL injured cases and uninjured controls matched for sex, age, height, and weight. This differentiation between groups appears to improve at 6 and 12 months following ACL reconstruction. The metabolites identified may provide insight into the pathways associated with the initiation and progression of post-traumatic osteoarthritis following ACL injury; however, further research and longer term follow-up in this cohort is needed to confirm this.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

The influence of malonic acid on the structural, morphological and optical properties of CdSe thin films prepared by chemical bath deposition method

Cadmium Selenide thin films were deposited on glass substrates by chemical bath deposition technique. The films have been characterized by using X-ray diffraction (XRD), UV–Vis spectroscopy, scanning electron microscopy (SEM), photoluminescence spectroscopy. The XRD study showed that the obtained thin films were CdSe with cubic crystal structure. The average crystallite size of 4.13–5.14 nm was obtained with different concentration of malonic acid. The relative intensities of the prominent diffraction peaks decreased with increasing concentration of malonic acid. The SEM images confirmed that there were considerable changes in the morphology of CdSe nanoparticles with the molar concentrations of malonic acid. The optical band gaps of the nanoparticle were estimated from the UV–Vis spectroscopy measurement and obtained in the range of 2.03 eV to 1.74 eV. The photoluminescence spectra showed a well-defined peak at 543 nm and shoulders around 487 nm and 530 nm for all CdSe thin films.

Experimental Study on Reactive Extraction of Malonic Acid with Validation by Fourier Transform Infrared Spectroscopy

Malonic acid is an essential carboxylic acid that is used as a backbone reactant in deriving multiple higher-order carboxylic compounds. The successful attempt of producing malonic acid from a biological route has attracted the scientific community to extract malonic acid from a fermentation broth or dilute aqueous stream. Experimental study on the recovery of malonic acid by reactive extraction was performed, and the effects of TBP concentration, diluents (alkane, ketone, and alcohol), and malonic acid concentration were investigated. The equilibrium models (relative basicity and mass action law models) and the number of theoretical units (NTU) were also evaluated. Fourier transform infrared spectroscopy provided evidence for the formation of significant bonds among extractant–diluent–acid complexation systems which support the experimental outcomes. The results of extraction equilibrium are discussed regarding dimerization constant (DMA), partition coefficient (PMA), extraction efficiency (EMA%), distri...

Multivariate statistical analysis of chemical and electrochemical oscillators for an accurate frequency selection.

The effect of experimental parameters on the frequency of chemical oscillators has been systematically studied since the first observations of clock reactions. The approach is mainly based on univariate changes in one specific parameter while others are kept constant. The frequency is then monitored and the effect of each parameter is discussed separately. This type of analysis, however, does not take into account the multiple interactions among the controllable parameters and the synergic responses on the oscillation frequency. We have carried out a multivariate statistical analysis of chemical (BZ-ferroin catalyzed reaction) and electrochemical (Cu/Cu2O cathodic deposition) oscillators and identified the contributions of the experimental parameters on frequency variations. The BZ reaction presented a strong dependence on the initial concentration of sodium bromate and temperature, resulting in a frequency increase. The concentration of malonic acid, the organic substrate, affects the system but with lower intensity compared with the combination of sodium bromate and temperature. On the other hand, the Cu/Cu2O electrochemical oscillator was shown to be less sensitive to changes in the temperature. The applied current density and pH were the two parameters which most perturbed the system. Interestingly, the frequency behaved nonmonotonically with a quadratic dependence. The multivariate analysis of both oscillators exhibited significant differences - while the homogenous oscillator displayed a linear dependence with the factors, the heterogeneous one revealed a more complex dependence with quadratic terms. Our results may contribute, for instance, in the synthesis of self-organized materials in which an accurate frequency selection is required and, depending on its value, different physicochemical properties are obtained.

Association between biomarkers of vitamin B12 status and the risk of neural tube defects.

The aim of this study was to evaluate the association between vitamin B12 and its biomarkers and the risk of neural tube defects. A total of 120 pregnant Egyptian women were included in the study. They were classified into two groups. Group A consisted of 50 women with neural tube defects in current pregnancy or with a history in previous pregnancies, and Group B consisted of 70 women with no history of neural tube defects in previous pregnancies or in the current pregnancy. All women were subjected to ultrasound anomaly scan and serum analysis of vitamin B12, homocysteine (Hcy), methyl malonic acid (MMA) and active vitamin B12 concentrations. Receiver operating characteristic curve analysis was used to determine the best cut-off values of vitamin B12. Serum levels of vitamin B12 were decreased in Neural tube defects (NTDs) cases compared to controls (2.736 vs 3.091 ng/mL; P = 0.0015), while Hcy and MMA concentrations were elevated (18.39 vs 13.95 μmol/L; P = 0.0008 and 263 vs 229.7 μmol/L; P = 0.003, respectively). Active vitamin B12 reduction was not statistically significant (96.8 vs 99.36 pmol/L; P = 0.8013). The optimal cut-off value of vitamin B12, 2.9 ng/mL, is the best threshold to expect neural tube defects, with a sensitivity of 60% and specificity of 74.29%. Low vitamin B12 is a risk factor for having a fetus with neural tube defects. The monitoring of MMA and Hcy levels might be important in understanding and following cases with neural tube defects. Adding vitamin B12 to folic acid may help to decrease the incidence of neural tube defects in the Egyptian population.

The potential role of malonic acid in the atmospheric sulfuric acid - Ammonia clusters formation

Malonic acid (MOA), one of the major dicarboxylic acids (DCAs) in aerosols, has been identified experimentally and computationally to be a strong acid. However, its potential role in the atmospheric clusters formation is still ambiguous. Hence, the participant mechanism of MOA on the formation of atmospheric sulfuric acid (SA)- ammonia (A) clusters was investigated by combining computational methods with atmospheric cluster dynamics code (ACDC). The most stable molecular structures obtained at the M06-2X/6-311++G(3df,3pd) level of theory shows that the added MOA molecule in the SA-A-based clusters presents a promotion on the interactions between SA and A molecules. ACDC simulations indicate directly an obvious enhancement strength RMOA on the clusters formation rates at 218 K and the concentration of MOA ([MOA]) larger than 108 molecules cm−3, up to five orders of magnitude. Meanwhile, enhancement strength of MOA is compared with that of glycolic acid, and as expected, MOA presents a superior enhancement strength. Both RMOA and the compared enhancement strength (rcom) present a positive dependency on [MOA] and a negative dependency on [SA]. With the increase of [A], both RMOA and rcom (except at [SA] = 104 molecules cm−3) first increase, reaching the maximum value and then decrease. Finally, a catalytic participant mechanism of MOA where MOA acts as a mediate bridge for the formation of pure SA-A-based clusters has been identified by tracing the main growth pathways of the system.

Dicarboxylic acids and levoglucosan in aerosols from Indo-Gangetic Plain: Inferences from day night variability during wintertime

This study assesses daytime and nighttime atmospheric abundance and molecular distribution of dicarboxylic acids (DCA: C2–C10) and biomass burning tracers (levoglucosan and biomass burning derived potassium: K+BB) in PM10 (particulate matter with aerodynamic diameter≤10μm) from an urban location, Kanpur (in central Indo-Gangetic Plain: IGP) during wintertime (December 2015–February 2016). In this study, PM10 varied from 130 to 242 and 175–388μgm−3 during daytime and nighttime, respectively. The average ratios of OC/EC (day: 12.3; night: 9.3) and WSOC/OC (day: 0.74; night: 0.48) were relatively high during daytime (OC: organic carbon; EC: elemental carbon; WSOC: water-soluble organic carbon). Strong linear correlations (R2≥0.6; p<0.05) of OC with levoglucosan and K+BB suggest biomass burning emission as predominant source of organic aerosols over the IGP. The measured concentrations of total DCA (ΣC2–C10) showed pronounced diurnal variability with a higher concentration during nighttime (2510±1025ngm−3) as compared to that in daytime (1499±562ngm−3). Concentrations of oxalic acid (C2), succinic acid (C4) and malonic acid (C3) were predominantly high as compared to other congeners of DCA (C2–C10) over central IGP. Relatively higher mass fraction (73.4%) of C2 in total DCA during nighttime than that in daytime (61.5%) indicates role of secondary organic aerosols (SOAs) formation involving aqueous-phase chemistry. Strong linear correlations of C2 with C3 and C4 plausibly suggest that C2 can have predominant formation pathways via decomposition of higher congeners of DCA. Overall, strong linear correlations of C2 with levoglucosan and sulphate suggest that biomass burning emission and secondary transformations are predominant sources of DCA over IGP during wintertime.

Influence of the Belousov–Zhabotinsky substrate concentration on the lifetime and self-oscillating behavior of a polymer solution

In this study, we synthesized a self-oscillating polymer chain with N-ethylacrylamide (NEAAm) as the main-chain. This exhibits a higher lower critical solution temperature than an N-isopropylacrylamide main chain. We subsequently measured the transmittance self-oscillation of poly[NEAAm-co-Ru(bpy) 3 ] [Ru(bpy) 3 = 4-vinyl-4’-methyl-2,2’-bipyridinebis(2,2’ bipyridine)bis(hexafluorophosphate) ruthenium] solutions comprising three Belousov-Zhabotinsky (BZ) substrates (malonic acid, sodium bromate, and sulfuric acid), under stirring at constant temperature. The soluble-insoluble self-oscillation of the polymer solution originated from the different solubility of the Ru(bpy) 3 moiety as a catalyst of the BZ reaction in the reduced and oxidized states. We demonstrated that the self-oscillating behavior was significantly affected by the initial concentration of the sodium bromate. Moreover, we clarified that the lifetime of the transmittance self-oscillation can be predicted from the initial concentration of malonic acid.

A New Approach for Fast Metabolic Diagnostics in CMAMMA.

The presence of increased urinary concentrations of both methylmalonic acid (MMA) and malonic acid (MA) is assumed to differentiate combined malonic and methylmalonic aciduria (CMAMMA), due to mutations in the ACSF3 gene, from other causes of methylmalonic aciduria (classic MMAemia). Detection of MA in urine, however, is challenging since excretion of MA can be easily missed. The objective of the study was to develop a method for quantification of MA in plasma to allow differentiation between CMAMMA and classic MMAemia. Compound heterozygosity for mutations in the ACSF3 gene was detected in two female siblings using diagnostic exome sequencing. Urine (MMA and MA) was analyzed with GC/MS, while plasma was analyzed with UPLC-MS/MS. MA/MMA ratios were calculated. Both patients had a severe psychiatric presentation (at the age of 6 years and 5.5 years, respectively) after a viral infection. MA excretion in the patients was only just above the highest control value in several samples. MA concentrations in plasma from the two patients were clearly above the highest value observed in control subjects. However, MA concentrations in plasma from patients with classic MMAemia were also elevated. Additional, calculation of MA/MMA ratio in plasma allowed to fully differentiate between CMAMMA and classic MMAemia. Calculating the MA/MMA ratio in plasma allows differentiation between CMAMMA and classic MMAemia. The full clinical spectrum of CMAMMA remains to be delineated.

Effect of initial substrate concentrations of the BZ reaction on self-oscillating of polymer chains with Fe(phen)3 catalyst

Self-oscillation for the poly(NIPAAm-co-Fe(phen)3) solution induced by the Belousov-Zhabotinsky (BZ) reaction was studied by changing initial substrate concentrations (i.e., malonic acid, potassium bromate, and sulphuric acid) of the BZ reaction and the concentration of polymer solution. The results showed that the self-oscillation could be controlled by changing the initial substrate concentrations of polymer and potassium bromate. However, the oscillation behavior was insensitive to the concentration of malonic acid and sulphuric acid.