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The hydrate blockage avoidance performance of two anti-agglomerants (coconut amidopropyl dimethylamine, propylene bis (octadecylamidopropyl dimethylammonium chloride)) and their mixtures with polyvinylpyrrolidone (PVP) was tested in a high-pressure rocking cell apparatus. The effect of gas–liquid ratio, water content and PVP concentration were analyzed. A method for evaluating the kinetic inhibiting and anti-agglomerating performance of hydrate inhibitors was established. It was found that coconut amidopropyl dimethylamine had good anti-agglomerating performance at a low gas–liquid ratio (0.5) and various water content levels (20~80%), while propylene bis (octadecylamidopropyl dimethylammonium chloride) had a good anti-agglomerating performance only at a low gas–liquid ratio (0.5) and high water content (80%), and the hydrate volume fraction was up to 23.27% for good anti-agglomeration. When PVP was mixed with the above two anti-agglomerants, it was found that coconut amidopropyl dimethylamine could significantly reduce the kinetic inhibition performance of PVP, while propylene bis (octadecylamidopropyl dimethylammonium chloride) had no significant effect on the kinetic inhibition performance of PVP. The maximum subcooling was 4.4 °C. PVP had no significant effect on the anti-agglomerating performance of the two anti-agglomerants, and the maximum hydrate volume fraction was 18.87% when the agglomeration was well inhibited. [ABSTRACT FROM AUTHOR]

The ammonia-ethanolamine water chemistry used at NPPs with VVER-1200 ensures low rates of corrosion, mass transfer, and growth of corrosion product deposits. The content of corrosion products in the feedwater of the steam generator is less than 1 μg/dm3. This significantly increases the period between flushing the steam generator to remove deposits. However, ethanolamine and ammonia are absorbed by the cation exchange resin in the ion-exchange filters of the secondary circuit purification systems, which leads to the need to regenerate the cation exchange resin and continuously dose reagents to maintain the required pH value in the feedwater. Waste solutions from regeneration containing ethanolamine and large amounts of ammonia must be treated to ensure that the concentrations of these substances do not exceed maximum permissible values when discharged into the environment. To remove ethanolamine and ammonia from regeneration solutions, special installations are created, the operation of which is based on various principles. A pilot plant for cleaning regeneration solutions was manufactured and installed at the Belarusian NPP with VVER-1200. An analysis of the pilot plant's operation showed that it successfully fulfills its function of protecting the aquatic environment but, at the same time, it is forced to release a significant amount of ammonia into the surrounding air. Removing ammonia is energy-consuming, environmentally unsafe, and requires the additional use of chemical reagents. In this regard, the water-chemical regime of the secondary circuit without ammonia is very promising. Possible options could be either switching from ammonia to dimethylamine or using ethanolamine as the only corrective reagent with the replacement of some of the structural materials of the secondary circuit with steels with a high chromium content, which have higher corrosion resistance compared to those currently used. Both options will simplify the wastewater treatment technology and reduce the environmental impact while maintaining the low corrosion rates achieved by using the ammonia–ethanolamine water chemistry. [ABSTRACT FROM AUTHOR]

Soft corals produce a diverse range of natural products with pharmaceutical potential, such as antiproliferative and anti-inflammatory effects. The Alcyoniidae family, particularly the genera Sarcophyton and Sinularia, is rich in bioactive terpenoids. However, despite extensive research, their anti-biofouling properties against the mussel Mytilus galloprovincialis remain underexplored. This study investigates these compounds as potential eco-friendly antifouling agents. A new cembrane-type diterpenoid, 11,12-epoxycembrene A (1), and 15 known compounds were isolated from three soft corals distributed in Okinawa, Japan. The chemical structures of these secondary metabolites were elucidated based on spectroscopic analysis. Moreover, an anti-biofouling assay of potential anti-biofouling agents against M. galloprovincialis was performed and their toxicities were assessed by means of the brine shrimp mortality test. In conclusion, this study identifies new and known bioactive compounds from soft corals, introduces an improved anti-biofouling assay, and highlights the potential of dimethylamine-containing diterpenes as environmentally friendly antifouling agents. [ABSTRACT FROM AUTHOR]

Metformin is commonly used to lower blood glucose levels and is one of the most widely used pharmaceuticals worldwide. Typical doses are high (0.5–2.0 g day−1 ) and the majority travels through the digestive system unabsorbed and enters the wastewater system. Metformin is not removed by standard wastewater treatments and eventually enters freshwater systems, where it can form N-chloro-derivatives that are toxic to fish and human cells. Thus, metformin is one of the most prevalent anthropogenic pollutants worldwide and there has been considerable interest in finding ways to remove it. We recently isolated Pseudomonads capable of growing on metformin as the sole nitrogen source. We identified candidate genes involved in metformin breakdown through genomic analyses informed by feeding studies. One candidate, a pair of genes that are located on ~80kb extra-genomic plasmids, was shown to encode a heteromeric Ni-dependent hydrolase that converts metformin to guanylurea and dimethylamine. Metforminase activity of these gene products is now well established as our results confirm three recently published independent studies. Our isolated Pseudomonads also grow on biguanide, suggesting the existence of an additional breakdown enzyme. Another candidate gene located on the ~80kb plasmids was shown to encode an aminohydrolase that converts biguanide to guanylurea. Biguanide may arise through successive N-demethylations of metformin or come from other sources. Our results suggest that the recent evolution of metforminase and biguanide hydrolase enzymes allow Pseudomonads to convert either metformin or biguanide to guanylurea, which can be assimilated by existing pathways. [ABSTRACT FROM AUTHOR]

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Ammonia and amines play critical roles in secondary aerosol formation, especially in urban environments. However, fast measurements of ammonia and amines in the atmosphere are very scarce. We measured ammonia and amines with a chemical ionization mass spectrometer (CIMS) at the urban center in Houston, Texas, the fourth most populated urban site in the United States, during October 2022. Ammonia concentrations were on average four parts per billion by volume (ppbv), while the concentration of an individual amine ranged from several parts per trillion by volume (pptv) to hundreds of pptv. These reduced nitrogen compounds were more abundant during weekdays than on weekends and correlated with measured CO concentrations, implying they were mostly emitted from pollutant sources. Both ammonia and amines showed a distinct diurnal cycle, with higher concentrations in the warmer afternoon, indicating dominant gas-to-particle conversion processes taking place with the changing ambient temperatures. Studies have shown that dimethylamine is critical for new particle formation (NPF) in the polluted boundary layer, but currently there are no amine emission inventories in global climate models (as opposed to ammonia). Our observations made in the very polluted area of Houston, as well as a less polluted site (Kent, Ohio) from our previous study (You et al., 2014), indicate there is a consistent ratio of dimethylamine over ammonia at these two sites. Thus, our observations can provide a relatively constrained proxy of dimethylamine using 0.1 % ammonia concentrations at polluted sites in the United States to model NPF processes. [ABSTRACT FROM AUTHOR]

The anti-diabetic drug metformin is one of the most widely prescribed medicines in the world. Together with its degradation product guanylurea, it is a major pharmaceutical pollutant in wastewater treatment plants and surface waters. An operon comprising two genes of the ureohydrolase family in Pseudomonas and Aminobacter species has recently been implicated in metformin degradation. However, the corresponding proteins have not been characterized. Here we show that these genes encode a Ni2+-dependent enzyme that efficiently and specifically hydrolyzes metformin to guanylurea and dimethylamine. The active enzyme is a heteromeric complex of α- and β- subunits in which only the α-subunits contain the conserved His and Asp residues for the coordination of two Ni2+ ions in the active site. A crystal structure of metformin hydrolase reveals an α2β4 stoichiometry of the hexameric complex, which is unprecedented in the ureohydrolase family. By studying a closely related but more widely distributed enzyme, we find that the putative predecessor specifically hydrolyzes dimethylguanidine instead of metformin. Our findings establish the molecular basis for metformin hydrolysis to guanylurea as the primary pathway for metformin biodegradation and provide insight into the recent evolution of ureohydrolase family proteins in response to an anthropogenic compound. The diabetes drug metformin and its degradation product guanylurea are major pharmaceutical contaminants in waste and surface water. Here, a Ni2+-dependent enzyme that hydrolysed metformin to guanylurea and its evolutionary predecessor are presented. [ABSTRACT FROM AUTHOR]

Three structurally diverse 5‐phenyltetrazolato (Tz) Ti, Zr, and Ta complexes, namely, (C2H8N)[Ti2(C7H5N4)5(C2H6N)4]·1.45C6H6 or (Me2NH2)[Ti2(NMe2)4(2,3‐μ‐Tz)3(2‐η1‐Tz)2]·1.45C6H6, (1·1.45C6H6), [Zr2(C7H5N4)6(C2H6N)2(C2H7N)2]·1.12C6H6·0.382CH2Cl2 or [Zr2(Me2NH)2(NMe2)2(2,3‐μ‐Tz)3(2‐η1‐Tz)2(1,2‐η2‐Tz)]·1.12C6H6·0.38CH2Cl2 (2·1.12C6H6·0.38CH2Cl2), and (C2H8N)2[Ta2(C7H5N4)8(C2H6N)2O]·0.25C7H8 or (Me2NH2)2[Ta2(NMe2)2(2,3‐μ‐Tz)2(2‐η1‐Tz)6O]·0.25C7H8 (3·0.25C7H8), where TzH is 5‐phenyl‐1H‐tetrazole, have been synthesized and structurally characterized. All three complexes are dinuclear; the Ti center in 1 is six‐coordinate, whereas the Zr and Ta atoms in 2 and 3 are seven‐coordinate. The coordination environments of the Ti centers in 1 are similar, and so are the ligations of the Ta centers in 3. In contrast, the two Zr centers in 2 bear a different number of ligands, one of which is a bidentate η2‐5‐phenyltetrazolato ligand that has not been observed previously for d‐block elements. The dimethylamido ligand, present in the starting materials, remained unchanged, or was converted to dimethylamine and dimethylammonium during the synthesis. Dimethylamine coordinates as a neutral ligand, whereas dimethylammonium is retained as a hydrogen‐bonded entity bridging Tz ligands. [ABSTRACT FROM AUTHOR]

Presented herein is a switchable synthesis of naphthalenone spiroindanediones or 4‐acyl‐1‐naphthols via condition‐controlled divergent cascade reactions of aryl enaminones with diazoindanediones. When the reaction was carried out in the presence of an oxidative additive, naphthalenone spiroindanedione was formed through C(sp2)−H alkylation followed by simultaneous spiroannulation and elimination of dimethylamine. When the reaction was carried out in the presence of an acid additive, on the other hand, 4‐acyl‐1‐naphthol was formed through ring opening of the spiroindanedione moiety attacked by the in situ released dimethylamine. In addition, the reactions are suitable for gram‐scale applications and compatible with a variety of substrates. Moreover, the naphthol products allow structural elaborations and hybridization with a drug, thus further enhancing the value of this developed method. [ABSTRACT FROM AUTHOR]

N-nitrosodimethylamine (NDMA) is a potentially carcinogenic byproduct of disinfecting drinking water. NDMA has been classified as a Group B2 carcinogen by the U.S. Environmental Protection Agency (EPA). The pathway of NDMA formation during chlorination has been proposed; however, it is still necessary to identify the most influential factor in this process. The objective of this study was to compare the factors and conditions that lead to the formation of NDMA from dimethylamine (DMA) to identify the primary factors responsible for the occurrence of this compound in drinking water. The study examined the formation of NDMA in chlorinated water under seven different conditions, considering three factors (NO2−, NO3−, and NH3). All factors were maintained at their actual concentrations in tap or surface water. The highest levels of NDMA were observed at pH 6 when NO3− and NH3 were present, with concentrations of 22.7 ng/L and 9.79 ng/L, respectively. At pH 6, NDMA levels were observed to be 22 times higher than at pH 8. Chlorine alone was not sufficient to convert DMA to NDMA within a short period of time, specifically at least 5 h, in the absence of other factors. The concentration of NDMA increased to 41.6 ng/L in the presence of NH3. After 16 h, the presence of NO3− led to a gradual increase in NDMA levels to 19.0 ng/L. However, no further increase was observed at this point. The findings suggest that NO3− and NH3 are important factors of NDMA in chlorinated drinking water. Although previous mechanisms have not given much attention to these factors, they are expected to play a significant role in the formation of nitrosamines in both natural water and drinking water. Controlling the factors or pH appeared to be crucial for managing NDMA formation, and further research on reducing N-nitrosamines is necessary. [ABSTRACT FROM AUTHOR]

2D organic–inorganic hybrid perovskites (OIHPs) are regarded as potential candidates for the advancement of multifunctional phase‐transition materials due to their ability to integrate flexible functionality and superior electronic features from both organic and inorganic components. However, the development of 2D OIHPs with dielectric switches and weak light detection capability that are crucial for high‐resolution sensing and imaging, remains challenge. Herein, a novel 2D OIHP BDADMAPb2Br7 (1, BDA = 1,4‐butanediamine and DMA = dimethylamine) is presented, featuring a 2D Dion–Jacobson (DJ) bilayered structure incorporated with secondary amine. Upon heating and cooling cycles, 1 demonstrates long‐term reversible dielectric switching properties at 328 K. Meanwhile, 1 also shows compelling semiconductor characteristics, including a low dark current of 2.87 × 10−11 A (10 V), a large switching ratio of 4 × 103, and a high detectivity of 1.3 × 1012 Jones. In addition, the photodetector based on 1 exhibits an excellent weak light detection ability of 340 nW cm−2 at 405 nm. Such a 2D OIHP demonstrates a novel platform for creating multifunctional materials and significantly promotes the development of integrated devices. [ABSTRACT FROM AUTHOR]

Next-generation risk assessment relies on mechanistic data from new approach methods, including transcriptome data. Various technologies, such as high-throughput targeted sequencing methods and microarray technologies based on hybridization with complementary probes, are used to determine differentially expressed genes (DEGs). The integration of data from different technologies requires a good understanding of the differences arising from the use of various technologies. To better understand the differences between the TempO-Seq platform and Affymetrix chip technology, whole-genome data for the volatile compound dimethylamine were compared. Selected DEGs were also confirmed using RTqPCR validation. Although the overlap of DEGs between TempO-Seq and Affymetrix was no higher than 37%, a comparison of the gene regulation in terms of log2fold changes revealed a very high concordance. RTqPCR confirmed the majority of DEGs from either platform in the examined dataset. Only a few conflicts were found (11%), while 22% were not confirmed, and 3% were not detected. Despite the observed differences between the two platforms, both can be validated using RTqPCR. Here we highlight some of the differences between the two platforms and discuss their applications in toxicology. [ABSTRACT FROM AUTHOR]

Selective synthesis of primary amines from nitriles is challenging in synthetic chemistry due to the possible en‐route generation of various amines and imines. Herein, we report a practical and operationally simple MOtBu‐mediated (M=Na, K) transfer hydrogenation of nitriles to the corresponding primary amines with a relatively unexplored sacrificial hydrogen source (dimethylamine borane). The strategy encompasses a broad substrate scope under transition metal‐free conditions and does not require any solvent. The mechanistic investigation was performed with the aid of control experiments and spectroscopic studies. The GC analysis of the reaction mixture exhibited the evolution of the H2 gas. Additionally, detailed computational calculations were undertaken to shed light on the possible intermediates and transition states involved during the present protocol. [ABSTRACT FROM AUTHOR]

Monomethylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) are important compounds for atmospheric key processes, e.g., new particle formation (NPF). A description of their multiphase chemical processing within atmospheric models is incomplete, but mandatory to describe their atmospheric budgets. In this study, a detailed multiphase chemistry mechanism was developed and first process model investigations were performed. The simulations focused on pristine marine conditions, where open research questions exist regarding ambient gas-phase concentrations of methylamines, particularly with regards to unexpectedly high DMA levels. The simulations reveal that TMA oxidation in cloud droplets results into DMA formation with a yield of around 87%, a missing DMA production pathway in current models. Also, it is demonstrated that about 21% and 69% of the respective DMA and TMA gas-phase oxidation proceed via autoxidation yielding HOOCH2NHCHO and HOOCH2N(CHO)CH2OOH, respectively. The discussed processes should be included into atmospheric models for advanced predictions of NPF and climate impacts. [ABSTRACT FROM AUTHOR]

α,β‐Unsaturated aldehydes are important building blocks for the synthesis of a wide range of chemicals, including polymers. The synthesis of these molecules from cheap feedstocks such as alkenes remains a scientific challenge, mainly due to the low reactivity of alkenes. Here we report a selective and metal‐free access to α,β‐unsaturated aldehydes from alkenes with formaldehyde. This reaction is catalyzed by dimethylamine and affords α,β‐unsaturated aldehydes in yields of up to 80 %. By combining Density Functional Theory (DFT) calculations and experiments, we elucidate the reaction mechanism which is based on a cascade of hydride transfer, hydrolysis and aldolization reactions. The reaction can be performed under very mild conditions (30–50 °C), in a theoretically 100 % carbon‐economical fashion, with water as the only by‐product. The reaction was successfully applied to non‐activated linear 1‐alkenes, thus opening an access to industrially relevant α,β‐unsaturated aldehydes from cheap and widely abundant chemicals at large scale. [ABSTRACT FROM AUTHOR]

Recent experiments have revealed a vital nucleation process of iodic acid (HIO 3) and iodous acid (HIO 2) under marine boundary layer conditions. However, HIO 3 –HIO 2 nucleation may not effectively drive the observed rapid new particle formation (NPF) in certain coastal regions influenced by urban air masses. Dimethylamine (DMA) is a promising basic precursor to enhance nucleation considering its strong ability to stabilize acidic clusters and the wide distribution in marine atmosphere, while its role in HIO 3 –HIO 2 nucleation remains unrevealed. Hence, a method combining quantum chemical calculations and Atmospheric Cluster Dynamics Code (ACDC) simulations was utilized to study the HIO 3 –HIO 2 –DMA nucleation process. We found that DMA can preferentially accept the proton from HIO 3 as a basic precursor in the most stable configurations of HIO 3 –HIO 2 –DMA clusters. Kinetically, the participation of DMA in the cluster formation pathways of the iodine oxoacid system could be significant at the 10 -1 to 1 pptv level of [DMA]. Furthermore, DMA can enhance the cluster formation rates of the HIO 3 –HIO 2 system in marine and polar regions near DMA sources more than 10 3 -fold. Compared to the classical nucleation mechanism, the HIO 3 –HIO 2 –DMA mechanism exhibits strong nucleation ability, worthy of consideration as a promising mechanism in marine and polar regions rich in amine sources. The newly proposed HIO 3 –HIO 2 –DMA ternary mechanism might provide an explanation for some missing fluxes of atmospheric iodine particles. [ABSTRACT FROM AUTHOR]

Exchange of B800 bacteriochlorophyll (BChl) a in light-harvesting complex 2 (LH2) is promising for a better understanding of the mechanism on intracomplex excitation energy transfer of this protein. Structural and spectroscopic properties of LH2 lacking B800 BChl a (B800-depleted LH2), which is an important intermediate protein in the B800 exchange, will be useful to tackle the energy transfer mechanism in LH2 by the B800 exchange strategy. In this study, we report a unique spectral change of B800-depleted LH2, in which the Qy absorption band of B800 BChl a is automatically recovered under neutral pH conditions. This spectral change was facilitated by factors for destabilization of LH2, namely, a detergent, lauryl dimethylamine N-oxide, and an increase in temperature. Spectral analyses in the preparation of an LH2 variant denoted as B800-recovered LH2 indicated that most BChl a that was released by decomposition of part of B800-depleted LH2 was a source of the production of B800-recovered LH2. Characterization of purified B800-recovered LH2 demonstrated that its spectroscopic and structural features was quite similar to those of native LH2. The current results indicate that the recovery of the B800 Qy band of B800-depleted LH2 originates from the combination of decomposition of part of B800-depleted LH2 and in situ reconstitution of BChl a into the B800 binding pockets of residual B800-depleted LH2, resulting in the formation of stable B800-recovered LH2. [ABSTRACT FROM AUTHOR]

The detection of volatile amines is necessary due to the serious toxicity hazards they pose to human skin, respiratory systems, and nervous systems. However, traditional amines detection methods require bulky equipment, high costs, and complex measurements. Herein, we report a new simple, rapid, convenient, and visual method for the detection of volatile amines based on the gas–solid reactions of tetrachloro-p-benzoquinone (TCBQ) and volatile amines. The gas–solid reactions of TCBQ with a variety of volatile amines showed a visually distinct color in a time-dependent manner. Moreover, TCBQ can be easily fabricated into simple and flexible rapid test strips for detecting and distinguishing n-propylamine from other volatile amines, including ethylamine, n-butyamine, n-pentamine, n-butyamine and dimethylamine, in less than 3 s without any equipment assistance. [ABSTRACT FROM AUTHOR]

Hydrogen-bonded organic frameworks (HOFs) are frameworks formed by organic building blocks through hydrogen bonding forces with promising applications in various fields. However, their development has been hindered by poor stability. In this work, a multiple hydrogen bond strategy with in situ generation of dimethylamine (DMA) is proposed to design robust HOFs. The protic acid HCl and Lewis acid Ag+ catalyze the cleavage of the amide C–N bond in the solvent N,N-dimethylformamide (DMF) molecules to generate dimethylamine (DMA) molecules in situ. Then, DMA molecules form multiple hydrogen bonds with dicarboxylic phenylporphyrin (DBP), and build a crystalline hydrogen-bonded organic framework (DBP-HOF), utilizing both their donor and acceptor on the N atom of each DMA molecule. Additionally, DBP's large π conjugate structure contributes to stabilizing DBP-HOF through strong π–π stacking interactions. Notably, DBP-HOF demonstrates excellent fluorescence performance for selective detection of Cu2+, as well as responsiveness towards methylene blue (MB) and indigo carmine (IC). Interestingly, each analyte elicits distinct fluorescence behavior from DBP-HOF, enabling their effective differentiation. This study holds significant implications for designing stable HOF materials and advancing their application in optical sensing. [ABSTRACT FROM AUTHOR]

Through computational analysis we found that pentazine and hexazine, two hypothetical high-energy density materials, exhibit inherent instability due to quantum tunneling effects. This instability remains even near the absolute zero, and therefore they can be deemed as unsynthesizable. We propose substituents that could potentially stabilize pentazine, especially dimethylamine. [ABSTRACT FROM AUTHOR]

The incorporation of organic ligands via post‐device treatment is an effective strategy to improve the stability of perovskite solar cells (PSCs). Although the active area is protected by metal electrode under post‐treatment, the aggression of post‐treatment ligands into active area cannot be avoided thoroughly. Unfortunately, the size of long‐chain amines is too large, and the three‐dimensional (3D) perovskite cannot maintain its 3D perovskite structure once the cation substitution occurs during the post‐treatment. Despite that the low‐dimensional (LD) perovskites are beneficial to stability, long‐chain amines are harmful to carrier transport in PSCs. Here, we introduce dimethylamine (DMA), a slightly oversized cation that can be doped into 3D perovskite structure, for post‐device treatment to improve the efficiency and stability of PSCs. After exposure to DMA gas, the inactive area of Cs/FA/MA mixed cation perovskite device that is not covered by metal electrode is converted into LD perovskite, passivating the defects of 3D perovskite in the active region, suppressing non‐radiation recombination and ion migration. As a result, we achieved a power conversion efficiency (PCE) of 22.29 % with negligible hysteresis and better stability after DMA post‐treatment, which is much higher than that (20.40 %) of the control device. [ABSTRACT FROM AUTHOR]

The reactions of glyoxal (CHO)2) with amines in cloud processes contribute to the formation of brown carbon and oligomer particles in the atmosphere. However, their molecular mechanisms remain unknown. Herein, we investigate the ammonolysis mechanisms of glyoxal with amines at the air‐water nanodroplet interface. We identified three and two distinct pathways for the ammonolysis of glyoxal with dimethylamine and methylamine by using metadynamics simulations at the air‐water nanodroplet interface, respectively. Notably, the stepwise pathways mediated by the water dimer for the reactions of glyoxal with dimethylamine and methylamine display the lowest free energy barriers of 3.6 and 4.9 kcal ⋅ mol−1, respectively. These results showed that the air‐water nanodroplet ammonolysis reactions of glyoxal with dimethylamine and methylamine were more feasible and occurred at faster rates than the corresponding gas phase ammonolysis, the OH+(CHO)2 reaction, and the aqueous phase reaction of glyoxal, leading to the dominant removal of glyoxal. Our results provide new and important insight into the reactions between carbonyl compounds and amines, which are crucial in forming nitrogen‐containing aerosol particles. [ABSTRACT FROM AUTHOR]

We reports the ex situ preparation of nanotitania supported ruthenium(0) nanoparticles (NPs) and their catalytic testing in dehydrogenation of dimethylamine borane (DMAB) in toluene solvent. Ru0/TiO 2 NPs are prepared following a 2-step process: Ru3+ ions are first impregnated from the aqueous solution on titania nanopowder and then, reduced by aqueous solution of sodium borohydride. The prepared Ru0/TiO 2 NPs are dried, bottled under inert N 2 gas atmosphere, and used for characterization by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), ICP-OES (inductively coupled plasma optical emission spectroscopy) and XPS (X-ray photoelectron spectroscopy). Ru0/TiO 2 NPs with various Ru loadings are tested as catalysts in hydrogen generation from DMAB and the Ru0/TiO 2 (0.48% wt. Ru) with an average diameter of 6.7 ± 1.3 nm is found to have the highest initial turnover frequency value of 1700 h−1 for the release of 1.0 mol H 2 per mole of DMAB at 60 °C. Results of the recyclability test indicate quite high durability of Ru0/TiO 2 NPs in dehydrogenation of DMAB. [Display omitted] • Ru0/TiO 2 NPs are prepared by impregnation of Ru3+ ions on the surface of titania followed by their reduction. • Ru0/TiO 2 NPs show high catalytic performance in dehydrogenation of dimethylamine borane. • Ru0/TiO 2 (0.48% wt. Ru) provide a record TOF value of 1700 h−1 in this reaction at 60 °C. [ABSTRACT FROM AUTHOR]

Platinum catalysts with {111} surface has obvious advantages, but the control of {111} exposure usually requires surfactants which cover the surface and decrease the catalytic performance. In this paper, tetrahedral platinum nanoparticle catalysts were successfully prepared with a simple one-step hydrothermal method and their size were successfully controlled under sub-5 nm. The tetrahedral morphology was controlled through the decomposition of dimethylamine by DMF and the small size was determined by alcohol acid radical. Because of the profitable effect of the amines for the tetrahedral morphology, no surfactant was need during the preparation. The catalysis activity was assured by the tetrahedral morphology with Pt {111} exposure without the surfactant covering, and the small size further increased the number of activity sites. For HOR, the catalyst showed higher activity, stronger anti-CO poisoning performance and longer stability than those of commercial catalyst with the same platinum load. For ORR, the catalyst also showed better performances which further promoted the four-electron reaction. Our simple preparation method successfully achieved the aims of the morphology control, size control and the elimination of surfactant, which effectively assured the good catalyst performances. The simple preparation path of such good catalysts shows a great application potential. [ABSTRACT FROM AUTHOR]

Metal-mediated N–H and C–H bond activation of aliphatic amines is an effective strategy for synthesizing biologically important molecules. Ln (Ln = La and Ce) atom reactions with dimethylamine are carried out in a pulsed-laser vaporization supersonic molecular beam source. A series of dehydrogenation species are observed with time-of-flight mass spectrometry, and the dehydrogenated Ln-containing species in the formula Ln(CH2NCH3) are characterized by single-photon mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and multiconfiguration self-consistent field and quasi-degenerate perturbation theory for the Ce species. The MATI spectrum of La(CH2NCH3) consists of a single vibronic band system, which is assigned to the ionization of the doublet ground state of N-methyl-lanthanaaziridine. The MATI spectrum of Ce(CH2NCH3) displays two vibronic band systems, which are attributed to the ionization of two-pair lowest-energy spin–orbit coupling states of N-methyl-ceraaziridine. Both metallaaziridines are three-membered metallacycles and formed by the thermodynamically and kinetically favorable concerted dehydrogenation of the amino group and one of the methyl groups. [ABSTRACT FROM AUTHOR]

The combination of electron-deficient viologen ligands with electron-rich POMs is a typical acceptor–donor system that has recently received much attention. Under solvothermal and hydrothermal conditions, by introducing three symmetric viologen ligands into POM-based hybrid materials, we successfully constructed four POMs–viologen inorganic–organic hybrid compounds, namely (1,3-bcbpy)2·(δ-Mo8O26) (1) (1,3-bcbpy·2Cl = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridine dichloride), {CoII(1,4-bcbpy)2(H2O)2[H2(β-Mo8O26)]}·2H2O·2CH2O (2), (1,4-bcbpy)2·(δ-Mo8O26)·2H2O (3) (1,4-bcbpy·2Cl = 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridine dichloride, CH2O = formaldehyde), and {CuII(1,1-pmbby)2(H2O)[H2(β-Mo8O26)2]}·5H2O·C2H7N (4) (1,1-pmbby·2Cl = 1,1′-[1,4-phenylbis(methylene)]bis-(4,4′-bipyridine)dichloride, C2H7N = dimethylamine). These four compounds exhibit different fascinating structures, especially compound 4 is a typical metal–organic framework. Compounds 1–4 exhibit good discoloration behaviors under various external stimuli. For example, compounds 1–4 showed a positive response to the irradiation from a 300 W Xe lamp. When a positive voltage was applied to the ECD based on compounds 1–4, 1/2/3/4-ECD underwent a significant color conversion. What's more, compound 4 also showed obvious discoloration results after heating. In a word, 1–4 are multifunctional discoloration materials under different external stimuli. In addition, the coated filter paper prepared based on compound 3 can be used as a new printing material medium and can be successfully applied in erasable inkless printing and dual anti-counterfeiting. [ABSTRACT FROM AUTHOR]

In order to provide atomistic details for the mechanism of the collisional dynamics of O(3P) and dimethylamine (DMA) in the triplet electronic surface, direct dynamics simulations are reported herein. The simulations are performed at the U‐HSE06/aug‐cc‐pVDZ level of theory. The results are reported for the relative collision energy of 7.8 kcal/mol. For the vibrational and rotational excitations, following temperature regimes have been considered: 200 and 10 K, respectively. Simulations reveal that the reaction can lead to two product channels in the considered energy regime: (1) 2OH + 2CH3NHCH2 and (2) 2OH + 2CH3NCH3. The computed reaction cross section for pathways 1 and 2 are as follows: 17.89 ± 0.20 Å2 and 3.28 ± 0.03 Å2, whereas the computed microcanonical reaction rate constants for pathways 1 and 2 are as follows: (4.21 ± 0.05)*10−10 and (7.72 ± 0.07)*10−11 cm3/(molecule sec). Both pathways follow direct and indirect H abstraction processes. Among the direct pathways, stripping and rebound mechanisms have been observed, whereas the indirect pathway involves formation of a post‐reaction complex having lifetime ~0.4–0.5 ps. The velocity scattering angle distribution for the reaction is dominated by scattering in the sideways (60–120 °) and backward (120–180 °) directions with some contribution from the scattering in the forward direction (0–60 °). [ABSTRACT FROM AUTHOR]

Recent experiment (He et al, 2021, Science) revealed a vital nucleation process of iodic acid (HIO3) and iodous acid (HIO2) under the marine boundary layer conditions. However, HIO3-HIO2 nucleation cannot effectively derive the observed rapid new particle formation (NPF) in broad marine regions. Dimethylamine (DMA) is a promising basic precursor to enhance nucleation considering its strong ability to stabilize acidic clusters and the wide distribution in marine atmosphere, while its role in HIO3-HIO2 nucleation remains unrevealed. Hence, a method combining quantum chemical calculations and Atmospheric Cluster Dynamics Code (ACDC) simulations was utilized to study the HIO3-HIO2-DMA nucleation process. We found that DMA can compete with HIO2 to accept the proton from HIO3 as a basic precursor in the most stable configurations of HIO3-HIO2-DMA clusters. DMA can significantly enhance the cluster formation rates of HIO3-HIO2 kinetically for more than 103-fold in regions with abundant amine and scarce iodine based on combined factors of high nucleation ability and high concentration of DMA. Furthermore, the iodine oxoacids nucleation enhanced by DMA may explain the sources of rapid NPF events under different conditions corresponding to multiple ocean regions, which can provide important inspirations to understand the frequent and intensive NPF events in broad marine regions. [ABSTRACT FROM AUTHOR]

Self‐assembly exploits noncovalent interaction to offer an effective method for the fabrication of materials. For Na9[EuW10O36] ⋅ 32H2O (EuW10), the negative charges and abundant oxygen atoms on its surface provide a handle for static self‐assembly. New properties are envisioned for EuW10 aggregates which are able to display such kinetics and time‐programming characteristics, in order to satisfy more complex and intelligent application scenarios, such as DNA binding and information encryption. In this work, EuW10 coupling with stimuli‐responsive dodecyl dimethylamine oxide (C12DMAO) can generate versatile aggregates with pH‐responsive properties. We demonstrated the temporal programming of the assembly and disassembly of EuW10 nanospheres using a pH clock reaction of acid/urease hydrolysis. The pH clock reaction endows EuW10 assemblies with dynamical properties, in which the charges and fluorescence changes are coded in this system. These fluorescent assemblies provide new application in time‐programmed DNA capture and information encryption. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials offer great prospects in room temperature (RT) gas sensors with minimum power consumption, compared to conventional metal oxide semiconductor sensors that require high temperature operation. In this work, we prepared violet phosphorus (VP) nanosheets by optimized liquid-phase exfoliation in various solvents. A highly sensitive gas sensor has been fabricated by using the prepared VP nanosheets for detection of dimethylamine (DMA), a toxic chemical widely used in various industries. The VP sensor shows an ultrafast response time of ∼2 s and high response to DMA at RT. The sensing mechanism has been analyzed by density functional theory calculations, revealing significant electron transfer from DMA to VP. This work explores the promise of VP in low power sensors. [ABSTRACT FROM AUTHOR]

The thermo-physical parameters like density (ρ), ultrasonic velocity (u) and viscosity (η) have been experimentally measured for the ternary liquid mixture of para-anisaldehyde (4-methoxy benzaldehyde) in n-Hexane solution with dimethylamine at various temperatures such as 303 K, 308 K and 313 K and at fixed frequency of 2 MHz. The thermodynamic and acoustical parameters such as adiabatic compressibility (β), internal pressure (πi), cohesive energy (CE), free volume (Vf), free length (Lf), acoustic impedance (z), viscous relaxation time, Lennard Jones potential (LJP), and K value have been calculated from the experimental data. The various excess properties including excess acoustic impedance (ZE), excess free length (LEf, excess adiabatic compressibility (βE), excess free volume (VfE), excess ultrasonic velocity (UE) and excess internal pressure (πiE) have also been computed from the calculated values. The values of UE, ZE, and LEF for each mixture have been fitted to the Redlich - Kister polynomial equation. The variation of these parameters with respect to different concentration at different temperatures for the ternary system of para-anisaldehyde + dimethylamine + n-hexane has been studied in accordance with their strength of molecular interaction under the influence of ultrasonic wave of frequency 2 MHz. [ABSTRACT FROM AUTHOR]

N,N-Dimethylformamide (DMF) is a universal solvent with wide applications across various industries. Current industrial synthesis requires high temperature and high pressure, starting from fossil-based carbon monoxide and dimethylamine (DMA). Herein, we report a green and electrochemical strategy to produce DMF under ambient conditions through direct oxidation of trimethylamine (TMA), which is a surplus chemical in DMA manufacturing. DMF production with 80% yield and >50% faradaic efficiency was achieved in an H-cell reactor over a graphite anode, coupled with hydrogen production at the cathode. Mechanistic investigations show that the reaction occurs through two-phase oxidation and that an aminal serves as the key intermediate. To achieve continuous DMF production, we set up a membrane-electrode assembly (MEA) flow reactor (2 cm × 2 cm), achieving a DMF productivity of 25 μmol h−1 and a faradaic efficiency of 40%. To further increase the productivity, we fabricated another membrane-free flow reactor (8 cm × 9 cm), delivering a high formation rate (550 μmol h−1) with high selectivity (>90%) at a constant current of 3 A in a 100-hour test. This study offers a unique opportunity to utilize electricity to drive surplus chemical utilization under ambient conditions, contributing to the sustainability of the chemical industry in the future. [ABSTRACT FROM AUTHOR]

Reports of aerobic biogenic methane (CH4) have generated new views about CH4 sources in nature. We examine this phenomenon in the free‐flowing Yellowstone river wherein CH4 concentrations were tracked as a function of environmental conditions, phototrophic microorganisms (using chlorophyll a, Chl a, as proxy), as well as targeted methylated amines known to be associated with this process. CH4 was positively correlated with temperature and Chl a, although diurnal measurements showed CH4 concentrations were greatest during the night and lowest during maximal solar irradiation. CH4 efflux from the river surface was greater in quiescent edge waters (71–94 μmol m−2 d) than from open flowing current (~ 57 μmol m−2 d). Attempts to increase flux by disturbing the benthic environment in the quiescent water directly below (~ 1.0 m deep) or at varying distances (0–5 m) upstream of the flux chamber failed to increase surface flux. Glycine betaine (GB), dimethylamine and methylamine (MMA) were observed throughout the summer‐long study, increasing during a period coinciding with a marked decline in Chl a, suggesting a lytic event led to their release; however, this did not correspond to increased CH4 concentrations. Spiking river water with GB or MMA yielded significantly greater CH4 than nonspiked controls, illustrating the metabolic potential of the river microbiome. In summary, this study provides evidence that: (1) phototrophic microorganisms are involved in CH4 synthesis in a river environment; (2) the river microbiome possesses the metabolic potential to convert methylated amines to CH4; and (3) river CH4 concentrations are dynamic diurnally as well as during the summer active months. [ABSTRACT FROM AUTHOR]

Methylamine has been the only simple alkylamine detected in the interstellar medium for a long time. With the recent secure and tentative detections of vinylamine and ethylamine, respectively, dimethylamine has become a promising target for searches in space. Its rotational spectrum, however, has been known only up to 45 GHz until now. Here we investigate the rotation-tunnelling spectrum of dimethylamine in selected regions between 76 and 1091 GHz using three different spectrometers in order to facilitate its detection in space. The quantum number range is extended to J  = 61 and  Ka  = 21, yielding an extensive set of accurate spectroscopic parameters. To search for dimethylamine, we refer to the spectral line survey ReMoCA carried out with the Atacama Large Millimeter/submillimeter Array towards the high-mass star-forming region Sagittarius B2(N) and a spectral line survey of the molecular cloud G+0.693–0.027 employing the IRAM 30 m and Yebes 40 m radio telescopes. We report non-detections of dimethylamine towards the hot molecular cores Sgr B2(N1S) and Sgr B2(N2b) as well as G+0.693−0.027 which imply that dimethylamine is at least 14, 4.5, and 39 times less abundant than methylamine towards these sources, respectively. The observational results are compared to computational results from a gas-grain astrochemical model. The modelled methylamine to dimethylamine ratios are compatible with the observational lower limits. However, the model produces too much ethylamine compared with methylamine which could mean that the already fairly low levels of dimethylamine in the models may also be too high. [ABSTRACT FROM AUTHOR]

Gas-phase dimethylamine (DMA) has recently been identified as one of the most important vapors to initiate new particle formation (NPF), even in China's polluted atmosphere. Nevertheless, there remains a fundamental need for understanding the atmospheric life cycle of DMA, particularly in urban areas. Here we pioneered large-scale mobile observations of the DMA concentrations within cities and across two pan-region transects of north-to-south (∼700 km) and west-to-east (∼2000 km) in China. Unexpectedly, DMA concentrations (mean ± 1 σ) in South China with scattered croplands (0.018 ± 0.010 ppbv, 1 ppbv=10−9 L/L) were over three times higher than those in the north with contiguous croplands (0.005 ± 0.001 ppbv), suggesting that nonagricultural activities may be an important source of DMA. Particularly in non-rural regions, incidental pulsed industrial emissions led to some of the highest DMA concentration levels in the world (>2.3 ppbv). Besides, in highly urbanized areas of Shanghai, supported by direct source-emission measurements, the spatial pattern of DMA was generally correlated with population (R 2 = 0.31) due to associated residential emissions rather than vehicular emissions. Chemical transport simulations further show that in the most populated regions of Shanghai, residential DMA emissions can contribute for up to 78% of particle number concentrations. Shanghai is a case study for populous megacities, and the impacts of nonagricultural emissions on local DMA concentration and nucleation are likely similar for other major urban regions globally. [ABSTRACT FROM AUTHOR]

Changes in serum concentration of methylarginines and amino acids after exercise are well documented, whereas the effects of exercise applied together with fasting are still debated and not thoroughly studied. Thus, we hypothesised that alterations in methylarginines such as ADMA, SDMA and L-NMMA might be responsible for decreased exercise performance after 8 days of fasting. Additionally, we propose that conditions in which the human body is exposed to prolonged fasting for more than a week elicit a distinctly different response to exercise than after overnight fasting. A group of 10 healthy men with previous fasting experience participated in the study. The exercise test was performed until exhaustion with a gradually increasing intensity before and after the 8-day fast. Blood samples were collected before and immediately after exercise. ADMA, SDMA, L-NMMA, dimethylamine and amino acids were analysed in serum samples by ID-LC-MS/MS. SDMA, L-NMMA and dimethylamine significantly decreased after 8 days of fasting, whereas ADMA did not change. BCAA, Phe, alanine and some other amino acids increased after fasting. Exercise-induced changes in amino acids were distinct after an 8-day fast compared to overnight fasting. A decrease in physical performance accompanied all of these alterations. In conclusion, our data indicate that neither methyl-arginine changes nor the Trp/BCAA ratio can explain exercise-induced fatigue after fasting. However, the observed decrease in hArg concentration suggests the limited synthesis of creatine, possibly contributing to reduced physical performance. [ABSTRACT FROM AUTHOR]

As one of the least understood aerosol processes, nucleation can be a dominant source of atmospheric aerosols. Sulfuric acid (SA)-amine binary nucleation with dimethylamine (DMA) has been recognized as a governing mechanism in the polluted continental boundary layer. Here we demonstrate the importance of trimethylamine (TMA) for nucleation in the complex atmosphere and propose a molecular-level SA-DMA-TMA ternary nucleation mechanism as an improvement upon the conventional binary mechanism. Using the proposed mechanism, we could connect the gaseous amines to the SA-amine cluster signals measured in the atmosphere of urban Beijing. Results show that TMA can accelerate the SA-DMA-based new particle formation in Beijing by 50–100%. Considering the global abundance of TMA and DMA, our findings imply comparable importance of TMA and DMA to nucleation in the polluted continental boundary layer, with probably higher contributions from TMA in polluted rural environments and future urban environments with controlled DMA emissions. [ABSTRACT FROM AUTHOR]

The widespread presence of volatile organic compounds (VOCs) is a threat to human health and environmental air quality. Dimethylamine is a highly toxic amine, which can directly affect the human respiratory system. To eliminate health risks, dimethylamine gas sensors are essential. Higher operating temperatures and poor selectivity inhibit binary metal oxides as sensing elements. In this work, inverse spinel cobalt tin oxide (Co2SnO4) thin films were deposited by the chemical spray pyrolysis method. Various phases have been addressed by the annealing conditions. Interestingly, the ordered inverse spinel turns into a disordered spinel by increasing the annealing temperature. All films were subjected to dimethylamine sensing, and the ordered inverse spinel porous nanograin Co2SnO4 thin films showed an excellent gas response of 193.53 ± 2.7 standard deviations at 100 ppm at room temperature, which demonstrates its potential use as a dimethylamine gas sensor. [ABSTRACT FROM AUTHOR]

The interaction of tris-dibenzoylmethanate Eu(III) with dimethylamine and ammonia vapors was investigated. It was found that when vapors of aqueous solutions of analytes are exposed to tris-dibenzoylmethanate Eu(III) impregnated into the SiO2 matrix, an optical response is observed in the form of an increase in the luminescence intensity of Eu(III). Changes in the luminescence spectra and luminescence excitation of this sensor are analyzed, both under the quenching action of water vapor and under the sensitizing action of analyte vapors. The main points recorded in the excitation spectra are noted, which are important for understanding the processes occurring in the near environment of the lanthanide center. The luminescent chemosensor is promising for creating sensors for detecting ammonia and amines in food safety control and environmental monitoring. [ABSTRACT FROM AUTHOR]

N -nitrosamines are genotoxic compounds which can be found as impurities in drug substances and drug products used in the pharmaceutical industry. To date, several possible nitrosamine sources in drug products have been reported and this study aims to illuminate another one. A case of afatinib drug product was investigated, in which up to 50 ppb N -nitrosodimethylamine (NDMA) traces were detected. Afatinib was found to degrade to the secondary amine dimethylamine (DMA), forming NDMA with traces of nitrite in crospovidone. Two series of film-coated tablets were prepared with crospovidone from two different manufacturers, containing different levels of nitrites. Tablets were subjected to an accelerated stability study (40 °C/75% relative humidity) or stored at room temperature and levels of NDMA, DMA and nitrite in tablets were monitored. NDMA and nitrite were found on ppb levels, whereas DMA was detected on ppm levels. NDMA formation in the drug product was found to be time, temperature and nitrite dependent and it was emphasized that DMA and nitrite should be reduced. The accelerated stability study proved to be a useful tool for predicting nitrosamine formation in the drug product. [Display omitted] [ABSTRACT FROM AUTHOR]

While many reactive species are known to cause N -nitrosation, trace nitrite (NO 2 −), which may be present in several excipients, is a source of nitrosating agents in pharmaceutical formulations. In this study we have found that the salt form of NO 2 − can influence the favored nitrosation conditions and final amount of nitrosamine being formed. Using native levels of NO 2 −, most likely present as ammonium nitrite (NH 4 NO 2), in microcrystalline cellulose, we have determined the kinetics of nitrosamine formation in solid state with dimethylamine substrate present in metformin, used as model compound. It was found that the competing degradation of NH 4 NO 2 into N 2 and H 2 O limited the amount of nitrosamine formation to a great extent. Empirically modelling the kinetic data predicted reaching at maximum 1.6% conversion over a hypothetical 3-year shelf-life. These results also showed that using other sources of NO 2 − as spiking reagents, such as NaNO 2 , may lead to unrealistic worst-case situations when the main form of NO 2 − in the drug product (DP) under evaluation may be NH 4 NO 2. As well, measuring NO 2 − in freshly manufactured excipients containing NO 2 − potentially as NH 4 NO 2 may lead to biased high NO 2 − content, which is not representative of the actual amounts present at the time of DP manufacture. [Display omitted] [ABSTRACT FROM AUTHOR]

The formation of N-nitrosodimethylamine (NDMA) in ranitidine hydrochloride drug substance (DS) and drug products has attracted considerable attention over the last few years. The drug structure is unusual in that it contains a vinyl nitro moiety. Although a variety of studies have been carried out to understand how NDMA is formed in the DS solids, a mechanistic description of NDMA formation has remained elusive. A new mechanistic view of NDMA formation is detailed here. Autoxidation of ranitidine can rationalize nitrite ion and dimethylamine liberation from ranitidine. The subsequent nitrosation is argued to be due to conversion of nitrite ion to the gas phase nitrosating agent nitrosyl chloride, NOCl. Oxygen scavenging packaging systems should be able to stop the autoxidation, and thus shut down the nitrite release from ranitidine. Without nitrite release NDMA cannot form. This may provide a practical means to stabilize ranitidine DS and solid dosage formulations against NDMA formation. [ABSTRACT FROM AUTHOR]

Cisplatin, doxorubicin, hydroxycamptothecin, leucovorin, vincristine and 5-fluorouracil resistance of cancer cells are associated with the activities of C-Jun N-Terminal Kinase 1 (JNK1). Inhibition of the JNK1 by pharmacological agents could be a beneficial attempt for reversing the chemoresistance of various cancer cells. However, there is no FDA-approved JNK inhibitor for safe use in clinics in today's clinics. In this study, a Schiff base 2-((4-(dimethylamino)benzylidene)amino)-5-methylphenol, (7S4) has been synthesized and characterized by 1H, 13C-NMR, FT-IR and elemental analysis. The stable geometry of 7S4 has been determined by DFT method with Gaussian09 program (B3LYP/6-311g++(d,p))). The Gibbs Free energies, stable tautomer forms, H-bond, Mulliken charges, dipole moment, natural bond orbital (NBO), HOMO, LUMO and band gap energy (EGAP), molecular electrostatic potential (MEP) and solvent accessibility surface areas (SASA) have been calculated. Drug-likeness, anticancer and JNK1 inhibitory activities of 7S4 have been evaluated. Enol tautomer form of trans 7S4 was characterized as the most stable structure. 7S4 was observed to be a reactive compound in chemical reactions with a low EGAP value. In addition, high and low electron density regions of 7S4 are responsible for the establishment of chemical bonds in biological systems. 7S4 exhibited strong druggability with the agreement on Lipinski, Ghose, Veber, Egan, and Muegge rules. Cytotoxicity tests and molecular docking revealed that 7S4 poses a potential JNK1 inhibitor activity. [ABSTRACT FROM AUTHOR]

Accurate detection of amines is crucial in various fields, but the coexistence of homologs severely hinders this accuracy. In this study, theoretical simulations and experiments were utilized to investigate the key factors influencing polyaniline adsorption behavior and gas-sensing selectivity towards amine homologs, which were identified as the charge and steric hindrance of the adsorption sites. Then, substituents such as chlorine, ethyl, amino, and methoxy groups were introduced at the ortho position of aniline monomers to modulate the adsorption driving force and resistance and thus regulate their selectivity towards amine homologs. Among them, poly(o-methoxyaniline) responded to only two primary amines, methylamine (MA) and ethylamine (EA), with MA/EA selectivity coefficient greater than 3, nearly achieving MA-specific detection. Poly(2-chloroaniline) exhibited high selectivity for dimethylamine (DMA), significantly enhanced the discrimination of DMA, EA, trimethylamine (TMA), and triethylamine (TEA), increasing the selectivity coefficients of DMA/EA, DMA/TMA, and DMA/TEA from 2.42, 1.05, and 1.03 for PANI to 3.49, 20.21, and 2.10. Furthermore, poly(2-chloroaniline) achieved an error of only 4 % in detecting DMA in a mixture with TMA at the same concentration. The influence of the material's intrinsic conductivity and matching with the response polarity on the suitability and sensitivity was also discussed. • The key factors impacting amine homologs selectivity of PANI were analyzed. • The effect of substituent on PANI selectivity for amine homologs was explored. • Poly(o-methoxyaniline) had nearly achieved specific detection of methylamine. • Poly(2-chloroaniline) significantly enhanced the discrimination of amine homologs. [ABSTRACT FROM AUTHOR]

• Dimethylamine compounds served as NDMA precursors in SR-AOPs with NO 2 − present. • NO 2 − can be oxidized by SO 4 •⁻ to form NO 2 • which dimerized to N 2 O 4. • Nitrosating agent N 2 O 4 played a key role in NDMA formation. • N 2 O 4 directly attacked the DMA moiety in the precursors to form NDMA. • NDMA yield was negatively related to the bond dissociation energy of precursors. Sulfate radical (SO 4 •−) advanced oxidation processes (SR-AOPs) are efficient for degrading a broad spectrum of contaminants. This study demonstrates that the existence of environmentally relevant concentrations of nitrite (NO 2 −) can lead to the formation of N -nitrosodimethylamine (NDMA), a probable human carcinogen, when heat activated peroxydisulfate (heat/PDS) is applied to address contaminants with dimethylamine moieties, such as tetracyclines. NO 2 − effectively competes with tetracyclines for SO 4 •− at a high second-order reaction rate constant of 8.8 × 108 M−1s−1, thus suppressing the degradation. Simultaneously, SO 4 •− reacts with NO 2 − to form the nitrogen dioxide radical (NO 2 •) which rapidly dimerizes to a potent nitrosating agent named dinitrogen tetroxide (N 2 O 4). N 2 O 4 , in turn, attacks the dimethylamine moiety in tetracyclines via nucleophilic substitution, contributing to the degradation of parent compounds and generating an active intermediate that quickly decomposes to NDMA, along with the release of R+ and NO 3 −. The released R+ can be further oxidized by SO 4 •− to form phenolic intermediates which combine with NO 2 • to generate nitrated products. When 5 μM oxytetracycline (OTC) was treated with 0.5 mM PDS in the presence of 20 μM NO 2 − at 60 °C, the highest formation of NDMA was 0.045 μM in 1 h. NDMA formation was also observed for other compounds with dimethylamine moieties, such as methylene blue, phenylurea herbicides, etc., with the molar yield ranging from 0.07 to 3.53 %, negatively related to the R-N bond dissociation energy of the precursors. These findings suggest that NDMA can be commonly generated when SO 4 •− is applied to the degradation of dimethylamine pollutants in wastewater treatment or groundwater remediation where NO 2 − ubiquitously exists, which may pose a serious threat to the aquatic environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Schematic representation of dimethylamine (DMA, (CH3)2NH) in gas-phase. (a) DMA in the α configuration; (b) DMA in the β configuration. The white, grey and blue spheres represent hydrogen, carbon and nitrogen atoms, respectively. [Display omitted] • Adsorptions of dimethylamine in the α-DMA and β-DMA configurations over Pt (001) and Pt (110) surfaces were investigated. • DFT: PBE, RPBE, revPBE, vdW-DF, vdW-DF2, BEEF-vdW and optPBE-vdW studies have been developed. • vdW functionals give adsorption energies which are higher than the standard DFT. • Projected density of states curves around N, C, and Pt have been discussed. The adsorptions of dimethylamine on Pt(001) and Pt(110) surfaces have been studied with the standard DFT and DFT + vdW methods using the periodic slab models. We determined adsorption energies and structural parameters of the dimethylamine for two adsorption configurations, with the hydrogen of the N H group pointing toward the surface or toward the vacuum region. The analysis of the adsorption energies shows that dimethylamine stabilizes strongly on the Pt(001) surface using DFT + PBE at the top site. However, the inclusion of vdW forces results in the increase of adsorption energy compared to values obtained from standard DFT, and there is chemisorption between dimethylamine and Pt surfaces. The adsorption energy of dimethylamine on the Pt(100) surface is found to be higher than that on the Pt(110) surface. Upon adsorption, changes in the structural parameters of dimethylamine were observed relative to the gas phase. Projected density of states (PDOSs) was also used to analyze the interaction between dimethylamine and Pt surfaces. Finally, our results demonstrate that the nature of standard and vdW functionals would provide significant support to experimentalists to obtain an accurate description of the adsorption of dimythelamine on Pt(001) and Pt(110) surfaces. [ABSTRACT FROM AUTHOR]

This study demonstrated the effects of the sludge type and inoculation method on the N,N-dimethylformamide degradation pathway and associated microbial communities. The sludge type is critical for DMF metabolism, with acclimatized aerobic sludge having a significant advantage in terms of DMF metabolism performance, whereas acclimatized anaerobic sludge has a reduced DMF metabolism capacity. Metagenomic revealed increased abundances of Methanosarcina , Pelomona and Xanthobacter in the adapted anaerobic sludge, suggesting that anaerobic sludge can utilize the methyl products produced by DMF metabolism for growth. Adapted aerobic sludge had high Mycobacterium abundance, significantly boosting DMF hydrolysis. In addition, a large number of dmfA2 genes were found in aerobic sludge, more so in acclimatized sludge, indicating stronger DMF metabolism. Conversely, acclimatized anaerobic sludge showed lower abundance of dmd-tmd and mauA/B , qhpA genes, implying long-term DMF toxicity reduced anaerobic microbial activity. Metaproteomic analysis showed that Methanosarcina and Methanomethylovorans enzymes in anaerobic sludge metabolized dimethylamine and methylamine to methane, aiding DMF degradation. In the aerobic sludge, aminohydrolase proteins, which hydrolyze DMF, were significantly upregulated. These findings provide insights into DMF wastewater treatment. [Display omitted] ● Aerobic sludge adapted to the environment excels in DMF metabolism. ● DMF toxicity inhibits anaerobic sludge, resulting in poorer DMF treatment capacity ● Adapted aerobic sludge shows high dmfA2 levels, crucial for DMF metabolism ● Methanosarcina and Methanomethylovorans key for DMF metabolism in anaerobic sludge [ABSTRACT FROM AUTHOR]

Herein, the results of in‐situ synthesis of four different metal(0) nanoparticles (Pd, Cu, Ru, and Ni) loaded on the surface of cellulose (MNPs@Cellulose) separately and their catalytic use in the solventless dimethylamine‐borane (DMAB) dehydrogenation at 35.0±0.1 °C are reported. Based on the detailed kinetic studies on the solventless DMAB dehydrogenation catalyzed using MNPs@Cellulose, the following results were obtained: (i) Optimum metal loading percentage on the surface of cellulose was determined for Pd@Cellulose to be 4.0 wt.%Pd (152.39 h−1), Ni@Cellulose to be 3.0 wt.%Ni (59.09 h−1), Cu@Cellulose to be 3.0 wt.%Cu (55.45 h−1) and Ru@Cellulose to be 4.0 wt.%Ru (46.06 h−1) and by determining total turnover frequency values in average 10th minutes (TOF10), which provided the highest catalytic activity. (ii) The optimum amount of cellulose for each metal was found to be 50.0 mg for Pd, Cu, and Ru, and 40.0 mg for Ni. (iii) The Arrhenius activation energies were determined for each metal nanoparticles and calculated to be 69±2, 34±2, 35±2 and 42±2 kj.mol−1 for Pd@Cellulose, Ni@Cellulose, Cu@Cellulose, and Ru@Cellulose, respectively. [ABSTRACT FROM AUTHOR]