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Thalassemia is a genetic disease that significantly affects human health. The common treatment of thalassemia is the regular injection of red blood cell, which is associated with the accumulation of iron in different tissues of the body, and makes chelation therapy necessary. Deferiprone and deferoxamine are broadly used as iron chelating agents in the vast majority of thalassemia cases. In this study, an efficient method for the synthesis of deferiprone was used by reacting maltol with methylamine in a mixture of water and ethanol as solvent. The structure of deferiprone was assigned using different spectroscopic techniques such as IR, 1H-NMR, and 13C-NMR. The advantages of this pathway are simple, practical, one-pot cascade, mild condition and high yield. The statistics of the Ministry of Health of Iran show the growing trend of deferiprone drug consumption in the country. Therefore, the domestic preparation of this drug can help the pharmaceutical industry in order to reduce costs and make it available for target patients.Keywords: Synthesis, Deferiprone, Maltol, Methylamine, Iron chelating agent.

Nitric acid (NA) has recently been found to enhance sulfuric acid (SA)-driven new particle formation (NPF) at low temperatures (≤240 K). However, studies on the role of NA in atmospheric NPF remain limited. Herein, we explored the enhancement effect of NA on binary SA–methylamine (MA) nucleation by investigating the mechanism and kinetics of (NA)x(SA)y(MA)z (0 ≤ x, 0 ≤ y, x + y ≤ 3, 0 ≤ z ≤ 3) clusters using quantum chemical calculations and cluster dynamics simulations. We found that the mixed ternary NA-SA-MA clusters have lower evaporation rates compared to the corresponding NA-SA–dimethylamine (DMA) and NA-SA–ammonia (A) clusters, indicating the stronger binding ability of NA with respect to SA-MA clusters. At atmospheric conditions (T ≥ 278.15 K), NA can enhance the cluster formation rate of SA-MA by about six orders of magnitude, demonstrating a surprisingly high enhancing potential. Moreover, NA acts as an important participant in the cluster growth pathways of the NA-SA-MA system, as opposed to the "bridging" role of NA in the previously studied NA-SA-A system. This study proposes the first case of NA efficiently enhancing SA–amine nucleation at ambient temperature, suggesting a larger impact of NA in atmospheric NPF than previously expected. [ABSTRACT FROM AUTHOR]

In this study, well-defined tungsten oxide (WO3) nanowall (NW) thin films were synthesized via a controlled hot filament chemical vapor deposition (HFCVD) technique and applied for electrochemical detection of methylamine toxic substances. Herein, for the thin-film growth by HFCVD, the temperature of tungsten (W) wire was held constant at ~1450 °C and gasification was performed by heating of W wire using varied substrate temperatures ranging from 350 °C to 450 °C. At an optimized growth temperature of 400 °C, well-defined and extremely dense WO3 nanowall-like structures were developed on a Si substrate. Structural, crystallographic, and compositional characterizations confirmed that the deposited WO3 thin films possessed monoclinic crystal structures of high crystal quality. For electrochemical sensing applications, WO3 NW thin film was used as an electrode, and cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were measured with a wide concentration range of 20 μM~1 mM of methylamine. The fabricated electrochemical sensor achieved a sensitivity of ~183.65 μA mM−1 cm−2, a limit of detection (LOD) of ~20 μM and a quick response time of 10 s. Thus, the fabricated electrochemical sensor exhibited promising detection of methylamine with considerable stability and reproducibility. [ABSTRACT FROM AUTHOR]

Thalassemia is a genetic disease that significantly affects human health. The common treatment of thalassemia is the regular injection of red blood cell, which is associated with the accumulation of iron in different tissues of the body, and makes chelation therapy necessary. Deferiprone and deferoxamine are broadly used as iron chelating agents in the vast majority of thalassemia cases. In this study, an efficient method for the synthesis of deferiprone was used by reacting maltol with methylamine in a mixture of water and ethanol as solvent. The structure of deferiprone was assigned using different spectroscopic techniques such as IR, 1H-NMR, and 13C-NMR. The advantages of this pathway are simple, practical, one-pot cascade, mild condition and high yield. The statistics of the Ministry of Health of Iran show the growing trend of deferiprone drug consumption in the country. Therefore, the domestic preparation of this drug can help the pharmaceutical industry in order to reduce costs and make it available for target patients. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the microsolvation effect on proton exchange (PE) between carbonic acid and methylamine (CA-MTA) has been explored by quantum dynamics simulations. The structural, energy, and dynamic properties of the CA-MTA complex with and without an explicit water molecule are elucidated at the molecular level. The reactions from this study have been clarified into different types: single-step PE (SSPE) and stepwise PE (SWPE). Without the water molecule, the SSPE mechanism is hardly found but observable with a low probability of 0.2. In particular, the water molecule interacting through intermolecular hydrogen-bonded network between CA and MTA in CA-MTA-Win could affect PE by showing both SSPE and SWPE mechanisms. In addition, the existing water molecule plays the significant role in shortening intermolecular hydrogen bonding interactions within the complex resulting in increasing the probability of PE up to 0.92 especially in CA-MTA-Wout. Hence, one water molecule could be used to provide reliable results to represent the significant activity that occurs for the proton exchangeability of the CA and MTA complex.

A number of compounds with various structures was obtained by the reaction of 2-propenylphenol, formaldehyde, and methylamine. The treatment of the condensation products with HBr resulted in their quaternary ammonium salts. The anticorrosion and biocidal properties and also antimicrobial activity of the obtained compounds and their ammonium salts in relation to S. aureus, E. coli, C. albicans, Sh. flexneri, S. enterica, and A. niger strains were studied. It was found that the ammonium salts have higher bactericidal properties than the standard (amoxicillin). The results obtained were also confirmed by electron microscopy studies. [ABSTRACT FROM AUTHOR]

Objectives: The present preliminary study aimed to investigate the salivary metabolic profile in patients with asymptomatic oral lichen planus (OLP) using nuclear magnetic resonance (NMR) spectroscopy. Material and methods: Stimulated whole mouth saliva (SWMS) samples were collected from 15 reticular OLP female patients and 15 from age- and sex-matched controls (HCs). A total of 23 metabolites were identified and quantified. Mann–Whitney’s U test was used to compare the determined concentration salivary metabolite concentrations between OLP patients and the healthy controls. Results: The concentration of acetate, methylamine, and pyruvate was elevated, whereas the concentration of tyrosine was decreased in the saliva of OLP patients compared with HCs. To identify a combination of metabolites, multivariate discrimination function analysis (DFA) was conducted. DFA analysis have shown that the most powerful discrimination between the groups was achieved when methylamine and tyrosine were considered as combined biomarkers. Conclusions: Salivary tyrosine was of particular interest and a promising finding for the screening of OLP and its progression. Further longitudinal studies are required to establish it as a reliable salivary biomarker in OLP. Clinical relevance: The salivary metabolic profiling can describe the pathologic characteristics of OLP on non-invasive saliva samples and NMR analysis. Salivary metabolites provide details to considered early detectors and to impact oral health of OLP patients. [ABSTRACT FROM AUTHOR]

Abstract Background Methanotrophy by the sponge-hosted microbiome has been mainly reported in the ecological context of deep-sea hydrocarbon seep niches where methane is either produced geothermically or via anaerobic methanogenic archaea inhabiting the sulfate-depleted sediments. However, methane-oxidizing bacteria from the candidate phylum Binatota have recently been described and shown to be present in oxic shallow-water marine sponges, where sources of methane remain undescribed. Results Here, using an integrative -omics approach, we provide evidence for sponge-hosted bacterial methane synthesis occurring in fully oxygenated shallow-water habitats. Specifically, we suggest methane generation occurs via at least two independent pathways involving methylamine and methylphosphonate transformations that, concomitantly to aerobic methane production, generate bioavailable nitrogen and phosphate, respectively. Methylphosphonate may be sourced from seawater continuously filtered by the sponge host. Methylamines may also be externally sourced or, alternatively, generated by a multi-step metabolic process where carnitine, derived from sponge cell debris, is transformed to methylamine by different sponge-hosted microbial lineages. Finally, methanotrophs specialized in pigment production, affiliated to the phylum Binatota, may provide a photoprotective function, closing a previously undescribed C1-metabolic loop that involves both the sponge host and specific members of the associated microbial community. Conclusion Given the global distribution of this ancient animal lineage and their remarkable water filtration activity, sponge-hosted methane cycling may affect methane supersaturation in oxic coastal environments. Depending on the net balance between methane production and consumption, sponges may serve as marine sources or sinks of this potent greenhouse gas. Video Abstract

Nitric acid (NA) has recently been found to enhance sulfuric acid (SA)-driven new particle formation (NPF) at low temperatures (≤240 K). However, studies on the role of NA in atmospheric NPF remain limited. Herein, we explored the enhancement effect of NA on binary SA–methylamine (MA) nucleation by investigating the mechanism and kinetics of (NA)x(SA)y(MA)z (0 ≤ x, 0 ≤ y, x + y ≤ 3, 0 ≤ z ≤ 3) clusters using quantum chemical calculations and cluster dynamics simulations. We found that the mixed ternary NA-SA-MA clusters have lower evaporation rates compared to the corresponding NA-SA–dimethylamine (DMA) and NA-SA–ammonia (A) clusters, indicating the stronger binding ability of NA with respect to SA-MA clusters. At atmospheric conditions (T ≥ 278.15 K), NA can enhance the cluster formation rate of SA-MA by about six orders of magnitude, demonstrating a surprisingly high enhancing potential. Moreover, NA acts as an important participant in the cluster growth pathways of the NA-SA-MA system, as opposed to the “bridging” role of NA in the previously studied NA-SA-A system. This study proposes the first case of NA efficiently enhancing SA–amine nucleation at ambient temperature, suggesting a larger impact of NA in atmospheric NPF than previously expected.

In this study, well-defined tungsten oxide (WO3) nanowall (NW) thin films were synthesized via a controlled hot filament chemical vapor deposition (HFCVD) technique and applied for electrochemical detection of methylamine toxic substances. Herein, for the thin-film growth by HFCVD, the temperature of tungsten (W) wire was held constant at ~1450 °C and gasification was performed by heating of W wire using varied substrate temperatures ranging from 350 °C to 450 °C. At an optimized growth temperature of 400 °C, well-defined and extremely dense WO3 nanowall-like structures were developed on a Si substrate. Structural, crystallographic, and compositional characterizations confirmed that the deposited WO3 thin films possessed monoclinic crystal structures of high crystal quality. For electrochemical sensing applications, WO3 NW thin film was used as an electrode, and cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were measured with a wide concentration range of 20 μM~1 mM of methylamine. The fabricated electrochemical sensor achieved a sensitivity of ~183.65 μA mM−1 cm−2, a limit of detection (LOD) of ~20 μM and a quick response time of 10 s. Thus, the fabricated electrochemical sensor exhibited promising detection of methylamine with considerable stability and reproducibility.

For ureosmotic marine elasmobranchs, the acquisition and retention of nitrogen is critical for the synthesis of urea. To better understand whole-body nitrogen homeostasis, we investigated mechanisms of nitrogen trafficking in North Pacific spiny dogfish (Squalus acanthias suckleyi). We hypothesized that the presence of nitrogen within the spiral valve lumen would affect both the transport of nitrogen and the mRNA abundance of a urea transporter (UT) and two ammonia transport proteins (Rhp2, Rhbg) within the intestinal epithelium. The in vitro preincubation of intestinal tissues in NH4Cl, intended to simulate dietary nitrogen availability, showed that increased ammonia concentrations did not significantly stimulate the net uptake of total urea or total methylamine. We also examined the mRNA abundance of UT, Rhp2, and Rhbg in the gills, kidney, liver, and spiral valve of fasted, fed, excess urea fed, and antibiotic-treated dogfish. After fasting, hepatic UT mRNA abundance was significantly lower, and Rhp2 mRNA in the gills was significantly higher than the other treatments. Feeding significantly increased Rhp2 mRNA levels in the kidney and mid spiral valve region. Both excess urea and antibiotics significantly reduced Rhbg mRNA levels along all three spiral valve regions. The antibiotic treatment also significantly diminished UT mRNA abundance levels in the anterior and mid spiral valve, and Rhbg mRNA levels in the kidney. In our study, no single treatment had significantly greater influence on the overall transcript abundance of the three transport proteins compared to another treatment, demonstrating the dynamic nature of nitrogen balance in these ancient fish. [ABSTRACT FROM AUTHOR]

Background: Methanotrophy by the sponge-hosted microbiome has been mainly reported in the ecological context of deep-sea hydrocarbon seep niches where methane is either produced geothermically or via anaerobic methanogenic archaea inhabiting the sulfate-depleted sediments. However, methane-oxidizing bacteria from the candidate phylum Binatota have recently been described and shown to be present in oxic shallow-water marine sponges, where sources of methane remain undescribed. Results: Here, using an integrative -omics approach, we provide evidence for sponge-hosted bacterial methane synthesis occurring in fully oxygenated shallow-water habitats. Specifically, we suggest methane generation occurs via at least two independent pathways involving methylamine and methylphosphonate transformations that, concomitantly to aerobic methane production, generate bioavailable nitrogen and phosphate, respectively. Methylphosphonate may be sourced from seawater continuously filtered by the sponge host. Methylamines may also be externally sourced or, alternatively, generated by a multi-step metabolic process where carnitine, derived from sponge cell debris, is transformed to methylamine by different sponge-hosted microbial lineages. Finally, methanotrophs specialized in pigment production, affiliated to the phylum Binatota, may provide a photoprotective function, closing a previously undescribed C1-metabolic loop that involves both the sponge host and specific members of the associated microbial community. Conclusion: Given the global distribution of this ancient animal lineage and their remarkable water filtration activity, sponge-hosted methane cycling may affect methane supersaturation in oxic coastal environments. Depending on the net balance between methane production and consumption, sponges may serve as marine sources or sinks of this potent greenhouse gas. 3rpQ8ar2d6vfELht75ymrg Video Abstract [ABSTRACT FROM AUTHOR]

Semicarbazide-sensitive amine oxidase (SSAO) is both a soluble- and membrane-bound transmembrane protein expressed in the vascular endothelial and in smooth muscle cells. In vascular endothelial cells, SSAO contributes to the development of atherosclerosis by mediating a leukocyte adhesion cascade; however, its contributory role in the development of atherosclerosis in VSMCs has not yet been fully explored. This study investigates SSAO enzymatic activity in VSMCs using methylamine and aminoacetone as model substrates. The study also addresses the mechanism by which SSAO catalytic activity causes vascular damage, and further evaluates the contribution of SSAO in oxidative stress formation in the vascular wall. SSAO demonstrated higher affinity for aminoacetone when compared to methylamine (Km = 12.08 µM vs. 65.35 µM). Aminoacetone- and methylamine-induced VSMCs death at concentrations of 50 & 1000 µM, and their cytotoxic effect, was reversed with 100 µM of the irreversible SSAO inhibitor MDL72527, which completely abolished cell death. Cytotoxic effects were also observed after 24 h of exposure to formaldehyde, methylglyoxal and H2O2. Enhanced cytotoxicity was detected after the simultaneous addition of formaldehyde and H2O2, as well as methylglyoxal and H2O2. The highest ROS production was observed in aminoacetone- and benzylamine-treated cells. MDL72527 abolished ROS in benzylamine-, methylamine- and aminoacetone-treated cells (**** p < 0.0001), while βAPN demonstrated inhibitory potential only in benzylamine-treated cells (* p < 0.05). Treatment with benzylamine, methylamine and aminoacetone reduced the total GSH levels (**** p < 0.0001); the addition of MDL72527 and βAPN failed to reverse this effect. Overall, a cytotoxic consequence of SSAO catalytic activity was observed in cultured VSMCs where SSAO was identified as a key mediator in ROS formation. These findings could potentially associate SSAO activity with the early developing stages of atherosclerosis through oxidative stress formation and vascular damage. [ABSTRACT FROM AUTHOR]

The performance of a film‐based fluorescent sensor is highly dependent on the innovative design of the sensing films aiming to elevate usability of sensing units, and enhance mass transfer of analytes within the fluorescent adlayer. Herein, a highly porous and uniform fluorescent nanofilm which is fabricated through an interfacially confined dynamic‐covalent reaction between benzene‐1,3,5‐tricarbo‐hydrazide and a mono‐boron complex of 8‐hydroxy‐quinoline is reported. Remarkably, the thicknesses of the nanofilms prepared in this way can be modulated from tens to hundreds of nanometers. In addition, the nanofilms demonstrate much improved photochemical stability. Sensing performance studies reveal that the nanofilm is super‐sensitive and selective to the presence of amines, especially methylamine (MA) in vapor phase. Specifically, the detection limit to MA is lower than 2.82 mg m−3, and the presence of the vapors of water, aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, ketones, and other common organic compounds showed little effect upon the sensing. Moreover, the sensing is highly reversible. With the innovation in adlayer structure, substrate effect as commonly found in routine film‐based sensing is avoided, which must bring convenience for device making. In this work, different film‐based sensors are fabricated, suggesting their potential applications in various scenarios. [ABSTRACT FROM AUTHOR]

• HNMs formation increased and then decreased with increasing Br‒ concentration. • BIF value increased while BUF value decreased with increasing Br− concentration. • pH value and Cl 2 :Br− ratio seriously affected the formation and species of HNMs. • The possible mechanisms of HNMs formation from methylamine were proposed. • The formation rule of HNMs was verified in two real waters containing methylamine. The UV/Cl 2 process is commonly used to achieve a multiple-barrier disinfection and maintain residuals. The study chose methylamine as a precursor to study the formation of high-toxic halonitromethanes (HNMs) in the presence of bromide ions (Br−) during UV/Cl 2 disinfection. The maximum yield of HNMs increased first and then decreased with increasing concentration of Br−. An excessively high concentration of Br− induced the maximum yield of HNMs in advance. The maximum bromine incorporation factor (BIF) increased, while the maximum bromine utilization factor (BUF) decreased with the increase of Br− concentration. The maximum yield of HNMs decreased as pH value increased from 6.0 to 8.0 due to the deprotonation process. The BUF value remained relatively higher under an acidic condition, while pH value had no evident influence on the BIF value. The maximum yield of HNMs and value of BUF maximized at a Cl 2 :Br− ratio of 12.5, whereas the BIF value remained relatively higher at low Cl 2 :Br− ratios (2.5 and 5). The amino group in methylamine was first halogenated, and then released into solution as inorganic nitrogen by the rupture of C-N bond or transformed to nitro group by oxidation and elimination pathways. The maximum yield of HNMs in real waters was higher than that in pure water due to the high content of dissolved organic carbon. Two real waters were sampled to verify the law of HNMs formation. This study helps to understand the HNMs formation (especially brominated species) when the UV/Cl 2 process is adopted as a disinfection technique. [Display omitted] [ABSTRACT FROM AUTHOR]

Methylamine exists as an endogenous amine in the brains of birds and mammals, and on the other hand, it acts as a neuromodulator in the release of some neurotransmitters such as serotonin. The effects of methylamine have been well established in mice, but there is no evidence about the effect of methylamine on feeding behavior in poultry. So, the present study was designed to evaluate the effect of intracerebroventricular (ICV) injection of methylamine and involvement of central methylamine/serotonergic systems on feeding behavior in FD3 neonatal meat type chicks. In experiment 1, chicks were ICV injected with different doses of methylamine (15, 30, 45, 60 and 75 μg). In experiment 2, chicks received a dose of either the control solution, 75 μg methylamine, 1/5 μg PCPA (serotonin synthesis inhibitor) or a combination of methylamine plus PCPA. Experiments 3 was similar to experiment 2 except that 1/5 μg SB242084 (antagonist of HT2C receptor) was used instead of 1/5 μg PCPA, respectively. Cumulative food intake was determined until 30, 60, 120 minutes post-injection. The volume of injections in each group was 10 μl. According to the results, methylamine significantly decreased food intake in a dose dependent manner. Therefore, the effective dose of methylamine was considered to be a continuation of the 75 μg test. It was also found that the hypophagic effect of methylamine by PCPA (inhibitor of serotonin synthesis, 1.5 μg) and SB242084 (antagonist of 5-HT2C receptor, 1.5 μg) was significantly attenuated. These results suggest that methylamine has a hypophagic effect on food intake in broiler chickens, and that this reduction in methylamine-induced food intake is mediated by serotonin (a 5-HT2C receptor). [ABSTRACT FROM AUTHOR]

[Display omitted] • ZrO 2 thin films were obtained by spray pyrolysis technique. • A ZrO 2 film showed a linear sensing response towards MMA vapour at 30 °C. • The lowest detection limit of MMA was determined to be 250 ppb. • The response and recovery times for 250 ppb of MMA were 90 s and 10 s, respectively. • Machine learning approaches for predicting low concentrations of MMA vapours. Methylamines are considered to be potential biomarker for disease diagnosis through exhaled breath analysis. Hence, the demand for probing methylamines has been increasing rapidly. Towards this, we report the room temperature selective Chemiresistive probing of methylamine using nanostructured-ZrO 2 thin film-based sensing elements deposited using spray pyrolysis method. The structural and morphological studies confirmed the formation of a monoclinic crystal phase and closely packed nanograins of ZrO 2 , respectively. The sensor showed a sensing response of 68 % with good sensitivity and fast switching transients towards 0.25 ppm of methylamines. The sensor showed selective sensing characteristics towards methylamine vapour among the different test volatiles with a minimum detection limit of 250 ppb. Also, the sensor showed a detection range of 250 ppb to 50 ppm concentration of methylamines. These significant figures of merit of the sensor operating at ambient temperature (30 °C) widely open up a new window for probing methylamine vapour effectively. [ABSTRACT FROM AUTHOR]

Metal–semiconductor–metal (MSM) configuration of perovskite photodetectors (PPDs) suggests easy and low-cost manufacturing. However, the basic structures of MSM PPDs include vertical and lateral configurations, which require the use of expensive materials such as transparent conductive oxides or/and sophisticated fabrication techniques such as lithography. Integrating metallic nanowire-based electrodes into the perovskite photo-absorber layer to form one-half of the MSM PPD structure could potentially resolve the key issues of both configurations. Here, a manufacturing of solution-processed and self-powered MSM PPDs with embedded silver nanowire electrodes is demonstrated. The embedding of silver nanowire electrode into the perovskite layer is achieved by treating the silver nanowire/perovskite double layer with a methylamine gas vapor. The evaporated gold layer is used as the second electrode to form MSM PPDs. The prepared MSM PPDs show a photoresponsivity of 4 × 10−5 AW−1 in the UV region and 2 × 10−5 AW−1 in the visible region. On average, the devices exhibit a photocurrent of 1.1 × 10−6 A under white light (75 mW cm−2) illumination with an ON/OFF ratio of 83.4. The results presented in this work open up a new method for development and fabrication of simple, solution-processable MSM self-powered PPDs. [ABSTRACT FROM AUTHOR]

In order to improve our understanding of the origin and production processes of methylamine in the atmosphere and its contribution to the particulate WSON, simultaneous measurements of methylamine in size-segregated aerosols and the gas phase were conducted at a forested site in Yamanashi Prefecture, Japan, over one year. The concentration of the atmospheric methylamine that is the sum of methylamine in the gas phase, coarse-mode, and fine-mode particles was 0.962 ng-N m-3 on average. About 77% of the atmospheric methylamine was detected in the fine-mode particles and about 17% was in the gas phase. Similar seasonal variations were found in the fine-mode and gaseous methylamine including higher concentrations recorded in summer. The relationship between the concentrations of the gaseous methylamine and ammonia showed a significant positive correlation, suggesting that methylamine in the gas phase has similar sources with ammonia; for instance, the volatilization from soil and/or emission from forest biological activities. The concentration of the fine-mode methylamine showed a significant positive correlation with that of the gaseous methylamine, and the concentration ratio of the fine-mode methylamine to the sum of the fine-mode and gaseous methylamine that can be an indicator of the conversion of methylamine from the gas phase to the particulate phase showed a significant positive correlation with the fine-mode non-sea salt SO42- (nss-SO42-) concentration, suggesting that the gaseous methylamine is converted into the particulate methylamine through the acid-base reaction with sulfuric acid and/or nss-SO42-. Significant positive correlation was not obtained in the comparison of the concentration ratio of the fine-mode methylamine to the sum of the fine-mode and gaseous methylamine with the excessive amount of sulfuric acid for complete neutralization of ammonia, which implies the possibility that the sulfuric acid more preferentially reacts with the gaseous methylamine than ammonia. [ABSTRACT FROM AUTHOR]

• The sensitivity and adsorption mechanism of MA and TMA on MnN 4 -C surface were studied. • MnN 4 -C exhibits good structural stability, and displays high sensitivity towards MA and TMA gases. • The gas sensing performance can be controlled by applying electric field. • MnN 4 -C can be regarded as the excellent reusability sensor for monitoring fish spoilage. From the perspective of raw material losses and human health, monitoring fish-based food quality has become more prominent. As a nondestructive technology, gas sensors have received extensive attention for evaluating the freshness of fish. In this study, the sensing and electronic properties of methylamine (MA) and trimethylamine (TMA) molecule adsorption on MnN 4 embedded zeolite templated carbon (MnN 4 -C) were studied by density functional theory (DFT) method. The results show that the MnN 4 -C exhibits good structural stability, and displays high sensitivity toward MA and TMA gases by analysis of the interaction distance, adsorption energy, charge transfer and sensing response. It is worth noting that the ambient humidity has demonstrated no effect on the gas-sensing properties of MnN 4 -C for the studied gases. Meanwhile, applying a positive electric field can increase the adsorption energy and charge transfer, which enhances the MA and TMA gas sensitivity of MnN 4 -C. The recovery time reveals that MnN 4 -C can be an excellent reusability sensor for MA and TMA gases. This study provides theoretical direction for exploring the sensing application of MnN 4 -C in evaluating freshness of fish. [ABSTRACT FROM AUTHOR]

N-methylcantharidimide (NMC), a derivative of cantharidin (C), shows antitumor properties. In this study, NMC was synthesized from C and methylamine with a yield of over 90%. We investigated the influences of different amounts of methylamine used in this reaction, and found that the optimal methylamine dosage was twice the theoretical amount. Furthermore, in the purification of NMC, distilled water was the most suitable solvent. This improved method is both simple and economical, and this process could be further developed at an industrial scale for the synthesis of NMC. [ABSTRACT FROM AUTHOR]

Metal–semiconductor–metal (MSM) configuration of perovskite photodetectors (PPDs) suggests easy and low-cost manufacturing. However, the basic structures of MSM PPDs include vertical and lateral configurations, which require the use of expensive materials such as transparent conductive oxides or/and sophisticated fabrication techniques such as lithography. Integrating metallic nanowire-based electrodes into the perovskite photo-absorber layer to form one-half of the MSM PPD structure could potentially resolve the key issues of both configurations. Here, a manufacturing of solution-processed and self-powered MSM PPDs with embedded silver nanowire electrodes is demonstrated. The embedding of silver nanowire electrode into the perovskite layer is achieved by treating the silver nanowire/perovskite double layer with a methylamine gas vapor. The evaporated gold layer is used as the second electrode to form MSM PPDs. The prepared MSM PPDs show a photoresponsivity of 4 × 10−5 AW−1 in the UV region and 2 × 10−5 AW−1 in the visible region. On average, the devices exhibit a photocurrent of 1.1 × 10−6 A under white light (75 mW cm−2) illumination with an ON/OFF ratio of 83.4. The results presented in this work open up a new method for development and fabrication of simple, solution-processable MSM self-powered PPDs.

The conversion of methylamine (CH 3 NH 2 , 1000 ppm) has been studied in an atmospheric-pressure flow reactor from both experimental and modeling points of view. Several values of the oxygen excess ratio (λ), from pyrolysis to fuel-lean conditions, have been tested, and a large number of different species have been quantified experimentally by three different diagnostic techniques: gas chromatography, Fourier Transform Infra-red spectroscopy (FTIR) and an infra-red NO analyzer. For the first time, the influence of NO addition (500 and 1000 ppm) on the stoichiometric oxidation of methylamine has also been experimentally evaluated, and the main products of such interaction have been identified. Results indicate that, unlike the little influence of oxygen availability on methylamine conversion, the presence of different concentrations of NO promotes methylamine oxidation at lower temperatures. A literature mechanism has been validated against the present experimental data since previous experimental works under these conditions are scarce. The largest discrepancies have been found for the formation of NH 3 and NO as oxidation products, which are under and overestimated by the model, respectively, and under pyrolysis conditions, where modification of the kinetic parameters for the reaction CH 2 NH 2 ⇌ CH 2 NH + H from the original mechanism notably improves the agreement between experimental and simulated results. [ABSTRACT FROM AUTHOR]

[Display omitted] We undertook density functional theory (DFT) computations for inspecting the decomposition and adsorption of methylamine (MLA) onto the surface of a pure boron nitride nano-tube (BNNT). We also obtained the activation energies of viable elementary reactions and the adsorption energies of stable complexes. The most suitable reaction pathway which generated one hydrogen cyanide molecule as well as 4 hydrogen atoms was relatively endothermal. For MLA decomposition, the energy barrier was around 44.6 kcal/mol. Due to the fact that the activation energy for the side reaction which generated NH 2 as well as CH 3 was somewhat high, reducing the temperature could depress the generation of side products. [ABSTRACT FROM AUTHOR]

The contribution of methanesulfonic acid (MSA) to new particle formation (NPF) has increased significantly with the strict implementation of anthropogenic SO 2 emission reductions globally. However, even considering the enhancing effect of methylamine (MA), identified as the strongest enhancer in MSA-driven NPF, the MSA-driven nucleation rates have been undervalued from the nucleation mechanism of the present theoretical simulation compared to field observations. So, it is vital to evaluate the participation and enhancement of MSA-MA clusters nucleation by the third atmospheric molecule. Herein, the role of trifluoroacetic acid (TFA), which has strong acidity and hydrogen bonding capabilities and is one of the most abundant atmospheric organic substances, has been investigated in the MSA-MA nucleation at different ambient atmospheres by quantum chemical calculations and atmospheric cluster dynamics code (ACDC) simulations. The results indicated that the enhancement strength R of TFA increased with decreasing temperature, up to 7.28-fold at 218.15 K, and is most remarkable in regions with insufficient MSA and relatively larger amounts of TFA and MA. The present results also revealed that TFA plays different roles under different atmospheric conditions. A "catalyst" role of TFA was found in the formation of MSA-MA-based clusters under relatively low temperatures (such as during winter or the top of troposphere at higher altitudes) and medium concentrations of TFA and MA. Whereas in the vicinity of major sources of TFA and MA emission (with the highest [TFA] and [MA]), TFA acted as a "direct participant" in the formation of nucleus clusters during winter or the top of troposphere (218.15 K). These new insights may be useful in understanding the perspective of the realistic role of TFA in MSA-MA-driven NPF, especially in the intensive human activity and industrial pollution serious of global megacities with winter of dry climate, or western China, Africa and the Arctic remote regions with scant precipitation and the abundant TFA pollutants sources. • TFA can enhance the formation rates of MSA-MA-based clusters at lower T and [MSA] as well as higher [TFA] and [MA]. • TFA can act as both a "catalyst" and a "participator" in the growth of MSA-MA clusters. • TFA is critical for NPF in the region of insufficient MSA and relatively larger amounts of TFA and MA. • This work reveals the realistic role of TFA in MSA-MA-driven NPF, especially in remote regions with scant precipitation. [ABSTRACT FROM AUTHOR]

The present study measured the concentrations of aliphatic amines (methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA), and triethylamine (TEA)) in both the aerosols and gas phase at a forested site in Japan, and discussed their seasonal trends and potential sources. These measured amines were more preferentially partitioned into the aerosols than into the gas phase, and mainly distributed into the fine-mode range in the aerosols, although the DMA and TMA were also abundant in the gas phase and the TMA in the aerosols was mainly distributed into the coarse-mode range. The most abundant amine both in the aerosol and gas phase was the DMA, followed by the MA. The MA, EA, DMA, and DEA in the gas phase and aerosols showed higher concentrations in the summer, although the coarse-mode EA concentration did not show the seasonality. The gaseous TMA also showed higher concentrations in the summer, but the coarse-mode TMA increased in the autumn and no seasonality was found in the fine-mode TMA concentrations. The TEA in the gas phase showed higher concentrations in the autumn, but that in the aerosols did not show the seasonality. The decomposition of organic materials in the soil and subsequent volatilization would be an important source of the gaseous MA, DMA, DEA, and TMA. Various biogenic activities can be also expected to be potential sources of the gaseous MA and DMA. The fine-mode MA, EA, DMA, DEA, TMA, and the coarse-mode DMA would be derived from their gaseous form through direct dissolution. Some portions of the fine-mode MA, DMA, and the coarse-mode DMA can be expected to be derived from the primary sources such as biogenic particles like plant debris. The transport of the anthropogenic aerosols can be also expected to contribute to the fine-mode MA. Only the TEA in the gas phase was suggested to be derived from the different sources in the forest from the other five gaseous amines and not contribute to the formation of the fine-mode TEA. It can be considered that the coarse-mode MA, EA, DEA, TMA, TEA, and the fine-mode TEA were affected by the sources independent from the local emission of the gaseous amines, such as the primary sources or the transport from distant sources, although some portions of the coarse-mode MA, EA and DEA might be derived from the dissolution of their gaseous form. Biogenic and pedospheric processes in the forest would be important sources for the amines, especially the gaseous and fine-mode amines, in a forest atmosphere. • The measured six amines were mainly distributed into the fine-mode aerosols. • The most abundant amine in the aerosol and gas phase was the DMA, followed by the MA. • Many of the gaseous and particulate amines showed high concentrations in the summer. • Decomposition of organic matters in the soil was a main source of the gaseous amines. • The fine-mode amines were mainly caused by the gas phase through direct dissolution. [ABSTRACT FROM AUTHOR]

UV/chloramine is considered a new potential disinfection process to substitute traditional disinfection methods, and the participation of bromide (Br−) significantly influences halonitromethanes (HNMs) formation during UV/chloramine disinfection. Herein, the formation laws of HNMs from methylamine were explored and compared during UV/chloramine disinfection with and without the existence of Br−. The results indicated that there were similar formation laws of HNMs between the disinfection processes with and without the existence of Br− but different species and productions of HNMs were observed. Furthermore, both the total HNMs productions during UV/chloramine disinfection with and without the existence of Br− were markedly enhanced when increasing chloramine dosage while those were significantly reduced when increasing solution pH from 6.0 to 8.0. Also, it was pointed out that Br− dramatically strengthened the toxicity of HNMs, and the toxicity alteration of HNMs was consistent with the changes in the yields of total HNMs with reaction time. Meanwhile, the reaction mechanisms of HNMs formed from methylamine were speculated during UV/chloramine disinfection with and without the existence of Br−, and Br− presented a non-negligible impact on the formation mechanisms. Finally, the formation laws of HNMs in two real water samples were found to be similar to that in simulated water samples during UV/chloramine disinfection, while different species and yields of HNMs were simultaneously observed. This work illustrated HNMs formation from methylamine and the significant impacts of Br− on HNMs generation during UV/chloramine disinfection. [Display omitted] • Similar formation laws of HNMs with time were found whether Br− was present or not. • Different HNMs species and yields were observed in the absence and presence of Br−. • Br− dramatically promoted the cytotoxicity and genotoxicity of total HNMs. • Formation mechanisms of HNMs in the absence and presence of Br− were proposed. • The formation laws of HNMs in real water were similar to that in stimulated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Methylamine is doubly ionized by a few-cycle intense near-infrared laser pulse. • Methylamine dication breaks into fragment ions via the singlet and triplet channels. • Kinetic energy releases of the Coulomb explosion are interpreted by DFT calculations. • Angular distributions of the fragments reflect the symmetries of HOMO of methylamine. • Ultrafast migration a hydrogen atom proceeds in methylamine cation and dication. Double ionization and ultrafast hydrogen migration of methylamine induced by a few-cycle intense near-infrared laser pulse are investigated by the coincidence momentum imaging method. By reference to the results obtained by DFT calculations, the peak profiles in the kinetic energy release distributions have been assigned to the singlet and triplet decomposition channels of CH 3 NH 2 2+. The anisotropy in the angular distribution of the ejection direction of the fragment ions is interpreted based on the symmetries of the (7a') HOMO orbital. By the pump–probe measurements, it is revealed that the ultrafast hydrogen migration in CH 3 NH 2 + proceeds within ∼ 30 fs. [ABSTRACT FROM AUTHOR]

On the analysis of cannabidiol (CBD) e-liquid by gas chromatography-mass spectrometry, we experienced suspected thermal decomposition of CBD to Δ9-tetrahydrocannabinol (Δ9-THC). To clarify the factors involved in the decomposition, we evaluated the effects of the injection methods (splitless or split), injector temperatures (250, 225, 200, and 180 °C), and liner conditions (new liner or used liner) on the CBD decomposition. We also examined whether addition of methylamine to the dissolving solvent (methanol) inhibited the decomposition. Decomposition was not observed under split mode. However, under splitless mode, we observed that decomposition was promoted with the use of used liner and by high injector temperatures, and addition of methylamine to the dissolving solvent also suppressed the decomposition. Split injection was effective for preventing the decomposition; however, splitless injection enables detection of lower-concentrated Δ9-THC in CBD products than split injection. To balance sensitivity of Δ9-THC and inhibition of the thermal decomposition under splitless mode, we recommend using new liner for the analysis, addition of methylamine to the dissolving solvent, and maintenance of the injector temperature at 200 °C. [ABSTRACT FROM AUTHOR]

ZnO and Pd-decorated ZnO nanoflowers are synthesized by a simple wet chemical method directly on interdigitated electrodes as promising amine sensors, which can potentially indicate meat spoilage. XRD and XPS characterization show the existence of crystalline, stoichiometric ZnO along with metallic Pd in the Pd-decorated ZnO materials. SEM and TEM studies show a nanoflower morphology, with well dispersed Pd nanoparticles on the surface of the ZnO nano- "petals". The chemiresistive gas sensing response is studied at different concentrations of methylamine (in the range of 25–400 ppm in air) and at different temperatures (25–250 °C), showing a superior response of 99.5% for Pd-decorated ZnO electrodes at 250 °C towards 400 ppm methylamine. The device also shows a promising response of 45% at the low temperature of 25 °C, making it a candidate sensing material for early detection of spoilage in meat-based products. • ZnO and ZnO-Pd nanoflowers are synthesized on interdigitated electrodes as superior amine gas sensors. • Pd nanoparticles are well distributed on the ZnO nano needles. • ZnO-Pd sensor has a response of 99.5% towards 400 ppm methylamine at 250 °C, while pure ZnO sensor's response is 45.5%. • ZnO-Pd sensor device has a promising response of 45% towards 400 ppm methylamine at the very low temperature of 25 °C. [ABSTRACT FROM AUTHOR]