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Antioxidants (Basel, Switzerland) Mar 2024Propyl-propane thiosulfonate (PTSO), an antioxidant organosulfur compound present in the genus , has become a potential natural additive for food and feed, as well as a...
Propyl-propane thiosulfonate (PTSO), an antioxidant organosulfur compound present in the genus , has become a potential natural additive for food and feed, as well as a possible biopesticide for pest control in plants. A toxicological assessment is necessary to verify its safety for livestock, consumers, and the environment. As part of the risk assessment of PTSO, this study was designed to explore its potential reproductive toxicity in mice following the OECD 416 guideline. The investigation spans two generations to comprehensively evaluate potential reproductive, teratogenic, and hereditary effects. A total of 80 CD1 mice per sex and generation were subjected to PTSO exposure during three phases (premating, gestation, and lactation). This evaluation encompassed three dose levels: 14, 28, and 55 mg PTSO/kg b.w./day, administered through the feed. No clinical changes or mortality attributed to the administration of PTSO were observed in the study. Some changes in the body weight and food consumption were observed, but not related to sex or in a dose-dependent manner. The two parental generations (F0, F1) exhibited normal reproductive performance, and the offspring (F1 and F2) were born without any abnormalities. The serum sexual hormone levels (progesterone -P-, testosterone -T-, estradiol -E2-, follicular stimulating hormone -FSH-, and luteinizing hormone -LH-) were in a normal range. Although significant changes were observed in the sperm analysis in the case of F0 group, no variation was found for F1 group, and no alterations in fertility were recorded either. The absolute organ weights and relative organ weight/body weight and organ weight/brain weight ratios, and the complete histopathological study, showed no significant alterations in males and females for all the generations considered. Considering all the results obtained, PTSO is not considered a reproductive or developmental toxicant in mice under the assayed conditions. These results support the good safety profile of PTSO for its potential application in the agrifood sector.
PubMed: 38539883
DOI: 10.3390/antiox13030350 -
Environmental Science & Technology Apr 2024Microbial aerobic cometabolism is a possible treatment approach for large, dilute trichloroethene (TCE) plumes at groundwater contaminated sites. Rapid microbial growth...
Microbial aerobic cometabolism is a possible treatment approach for large, dilute trichloroethene (TCE) plumes at groundwater contaminated sites. Rapid microbial growth and bioclogging pose a persistent problem in bioremediation schemes. Bioclogging reduces soil porosity and permeability, which negatively affects substrate distribution and contaminant treatment efficacy while also increasing the operation and maintenance costs of bioremediation. In this study, we evaluated the ability of acetylene, an oxygenase enzyme-specific inhibitor, to decrease biomass production while maintaining aerobic TCE cometabolism capacity upon removal of acetylene. We first exposed propane-metabolizing cultures (pure and mixed) to 5% acetylene (v v) for 1, 2, 4, and 8 d and we then verified TCE aerobic cometabolic activity. Exposure to acetylene overall decreased biomass production and TCE degradation rates while retaining the TCE degradation capacity. In the mixed culture, exposure to acetylene for 1-8 d showed minimal effects on the composition and relative abundance of TCE cometabolizing bacterial taxa. TCE aerobic cometabolism and incubation conditions exerted more notable effects on microbial ecology than did acetylene. Acetylene appears to be a viable approach to control biomass production that may lessen the likelihood of bioclogging during TCE cometabolism. The findings from this study may lead to advancements in aerobic cometabolism remediation technologies for dilute plumes.
Topics: Trichloroethylene; Acetylene; Biodegradation, Environmental; Bacteria; Biomass; Groundwater
PubMed: 38531380
DOI: 10.1021/acs.est.3c08068 -
The Journal of Physical Chemistry. A Apr 2024Experimental and theoretical studies were carried out to investigate the ozonolysis of -2-methyl-2-pentenal. The experiments were conducted in atmospheric simulation...
Experimental and theoretical studies were carried out to investigate the ozonolysis of -2-methyl-2-pentenal. The experiments were conducted in atmospheric simulation chambers coupled to a Fourier transform infrared (FTIR) spectrometer and a gas chromatograph-mass spectrometer at room temperature and atmospheric pressure in the presence of an excess of cyclohexane in dry conditions (RH < 1%). The ozonolysis reaction was investigated theoretically from the results of accurate density functional (M06-2X) and ab initio [CCSD(T)] computations, employing the AVTZ basis set. The sequence of reaction steps was established, and the system of kinetics equations was modeled using MESMER. In the first step, a primary ozonide is formed, which then decomposes along two pathways. The principal ozonolysis products are propanal, methylglyoxal, ethylformate, and a secondary ozonide. An interesting competition between sequential reaction steps and well-skipping is found, which leads to an inversion of the expected methylglyoxal/propanal product ratio at temperatures below 210 K. The mechanism of the "hot ester" reaction channel of the Criegee intermediate was revisited. The computed ozonolysis rate constant and product branching ratio are in excellent agreement with the experimental data that are also reported in the present work.
PubMed: 38530340
DOI: 10.1021/acs.jpca.3c04965 -
Inorganic Chemistry Apr 2024We present a bifunctional heptanuclear cobalt(II)/cobalt(III) molecular complex formulated as [Co(μ-OH)(HL)(HL)](NO)·6HO () (where HL is...
Heptanuclear Mixed-Valence CoCo Molecular Wheel─A Molecular Analogue of Layered Double Hydroxides with Single-Molecule Magnet Behavior and Electrocatalytic Activity for Hydrogen Evolution Reactions.
We present a bifunctional heptanuclear cobalt(II)/cobalt(III) molecular complex formulated as [Co(μ-OH)(HL)(HL)](NO)·6HO () (where HL is 2,2'-(((1E,1'E)-((2-hydroxy-5-methyl-1,3-phenylene)bis(methanylylidene))bis(azanylylidene))bis(propane-1,3-diol)) and HL is 2-amino-1,3-propanediol). Compound has been characterized by single-crystal X-ray diffraction analysis along with other spectral and magnetic measurements. Structural analysis indicates that contains a mixed-valence Co cluster where a central Co(II) ion is connected to six different Co centers (four Co and two Co ions) by four μ-OH groups, giving rise to a planar heptanuclear cluster that resembles a molecular fragment of a layered double hydroxide (LDH). Two triply deprotonated (HL) ligands form the outer side of the cluster while two singly deprotonated (HL) ligands are located at the top and bottom of the central heptanuclear core. Variable temperature magnetic measurements indicate the presence of weak ferromagnetic Co···Co interactions ( = 3.53(6) cm) within the linear trinuclear Co cluster. AC susceptibility measurements show that is a field-induced single-molecule magnet (SMM) with τ = 8.2(7) × 10 s and = 11.3(4) K. The electrocatalytic hydrogen evolution reaction (HER) activity of in homogeneous phase shows an overpotential of 455 mV, with a Faradaic efficiency of 81% and a TOF of 8.97 × 10 μmol H h mol.
PubMed: 38526851
DOI: 10.1021/acs.inorgchem.3c04065 -
Industrial & Engineering Chemistry... Mar 2024Temporal analysis of products (TAP) reactors enable experiments that probe numerous kinetic processes within a single set of experimental data through variations in...
Temporal analysis of products (TAP) reactors enable experiments that probe numerous kinetic processes within a single set of experimental data through variations in pulse intensity, delay, or temperature. Selecting additional TAP experiments often involves an arbitrary selection of reaction conditions or the use of chemical intuition. To make experiment selection in TAP more robust, we explore the efficacy of model-based design of experiments (MBDoE) for precision in TAP reactor kinetic modeling. We successfully applied this approach to a case study of synthetic oxidative propane dehydrogenation (OPDH) that involves pulses of propane and oxygen. We found that experiments identified as optimal through the MBDoE for precision generally reduce parameter uncertainties to a higher degree than alternative experiments. The performance of MBDoE for model divergence was also explored for OPDH, with the relevant active sites (catalyst structure) being unknown. An experiment that maximized the divergence between the three proposed mechanisms was identified and provided evidence that improved the mechanism discrimination. However, reoptimization of kinetic parameters eliminated the ability to discriminate between models. The findings yield insight into the prospects and limitations of MBDoE for TAP and transient kinetic experiments.
PubMed: 38525291
DOI: 10.1021/acs.iecr.3c03418 -
Neuroscience Letters Mar 2024New psychoactive substances (NPS) are typically synthesized in clandestine laboratories in an attempt to chemically modify already federally regulated drugs in an effort...
New psychoactive substances (NPS) are typically synthesized in clandestine laboratories in an attempt to chemically modify already federally regulated drugs in an effort to circumvent the law. Drugs derived from a phenethylamine pharmacophore, such as 4-chloroamphetamine and 3,4-methylenedioxymethamphetamine (MDMA), reliably induce thermogenesis and serotonergic deficits in the striatum and hippocampus of rodents. 4-methylamphetamine (4-MA), a relative newcomer to the NPS scene, was originally investigated in the mid-1900 s as a potential anorexigenic agent. With its phenethylamine pharmacophore, 4-MA was hypothesized to produce similar toxicological alterations as its chemical analogs. In the present study, three doses (1.0, 2.5, and 5.0 mg/kg, ip.) of 4-MA were administered to rats twice daily for two days. Core temperature data were calculated and analyzed as temperature area under the curve (TAUC). On the second day of dosing, a hypothermic response to 4-MA (2.5 and 5.0 mg/kg) was noted between 0.5 and 2.0 h post-treatment. Only the highest dose of 4-MA decreased body weight on the second day of treatment and maintained this reduction in weight for seven days after treatment ceased. None of the doses of 4-MA evaluated significantly altered serotonin levels in the hippocampus or striatum seven days after final treatment. The present findings demonstrate that the 4-methyl substitution to amphetamine generates a pharmacological and toxicological profile that differs from other similar phenethylamine analogs.
Topics: Rats; Animals; Methamphetamine; Serotonin; Designer Drugs; Temperature; N-Methyl-3,4-methylenedioxyamphetamine; Amphetamine; Hippocampus; Serotonin Agents; Amphetamines
PubMed: 38521402
DOI: 10.1016/j.neulet.2024.137740 -
Geoscientific Model Development Feb 2024We updated the chemical mechanism of the GEOS-Chem global 3-D model of atmospheric chemistry to include new recommendations from the NASA Jet Propulsion Laboratory (JPL)...
We updated the chemical mechanism of the GEOS-Chem global 3-D model of atmospheric chemistry to include new recommendations from the NASA Jet Propulsion Laboratory (JPL) chemical kinetics Data Evaluation 19-5 and from the International Union of Pure and Applied Chemistry (IUPAC) and to balance carbon and nitrogen. We examined the impact of these updates on the GEOS-Chem version 14.0.1 simulation. Notable changes include 11 updates to reactions of reactive nitrogen species, resulting in a 7% net increase in the stratospheric NO (NO + NO) burden; an updated CO + OH rate formula leading to a 2.7% reduction in total tropospheric CO; adjustments to the rate coefficient and branching ratios of propane + OH, leading to reduced tropospheric propane (-17%) and increased acetone (+3.5%) burdens; a 41% increase in the tropospheric burden of peroxyacetic acid due to a decrease in the rate coefficient for its reaction with OH, further contributing to reductions in peroxyacetyl nitrate (PAN; -3.8%) and acetic acid (-3.4%); and a number of minor adjustments to halogen radical cycling. Changes to the global tropospheric burdens of other species include -0.7% for ozone, +0.3% for OH (-0.4% for methane lifetime against oxidation by tropospheric OH), +0.8% for formaldehyde, and -1.7% for NO. The updated mechanism reflects the current state of the science, including complex chemical dependencies of key atmospheric species on temperature, pressure, and concentrations of other compounds. The improved conservation of carbon and nitrogen will facilitate future studies of their overall atmospheric budgets.
PubMed: 38510104
DOI: 10.5194/gmd-17-1511-2024 -
Fa Yi Xue Za Zhi Feb 2024To investigate the toxicokinetic differences of 3,4-methylenedioxy--methylamphetamine (MDMA) and its metabolite 4,5-methylene dioxy amphetamine (MDA) in rats after...
OBJECTIVES
To investigate the toxicokinetic differences of 3,4-methylenedioxy--methylamphetamine (MDMA) and its metabolite 4,5-methylene dioxy amphetamine (MDA) in rats after single and continuous administration of MDMA, providing reference data for the forensic identification of MDMA.
METHODS
A total of 24 rats in the single administration group were randomly divided into 5, 10 and 20 mg/kg experimental groups and the control group, with 6 rats in each group. The experimental group was given intraperitoneal injection of MDMA, and the control group was given intraperitoneal injection of the same volume of normal saline as the experimental group. The amount of 0.5 mL blood was collected from the medial canthus 5 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h after administration. In the continuous administration group, 24 rats were randomly divided into the experimental group (18 rats) and the control group (6 rats). The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5, 7, 9, 11, 13, 15, 17 mg/kg per day, respectively, while the control group was given the same volume of normal saline as the experimental group by intraperitoneal injection. On the eighth day, the experimental rats were randomly divided into 5, 10 and 20 mg/kg dose groups, with 6 rats in each group. MDMA was injected intraperitoneally, and the control group was injected intraperitoneally with the same volume of normal saline as the experimental group. On the eighth day, 0.5 mL of blood was taken from the medial canthus 5 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h after administration. Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels, and statistical software was employed for data analysis.
RESULTS
In the single-administration group, peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration, respectively, with the largest detection time limit of 12 h. In the continuous administration group, peak concentrations were reached at 30 min and 1.5 h after administration, respectively, with the largest detection time limit of 10 h. Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows: =10.362, =0.974 6; =7.397 3, =0.961 5 (: injection time; : concentration ratio of MDMA to MDA in plasma).
CONCLUSIONS
The toxicokinetic data of MDMA and its metabolite MDA in rats, obtained through single and continuous administration, including peak concentration, peak time, detection time limit, and the relationship between concentration ratio and administration time, provide a theoretical and data foundation for relevant forensic identification.
Topics: Rats; Animals; Amphetamine; N-Methyl-3,4-methylenedioxyamphetamine; 3,4-Methylenedioxyamphetamine; Toxicokinetics; Saline Solution; Amphetamines
PubMed: 38500459
DOI: 10.12116/j.issn.1004-5619.2022.320201 -
Journal of Forensic and Legal Medicine Apr 2024Volatile Solvents Abuse (VSA) poses major health risks, especially for young people and those living in precarious socio-economic conditions. Such substances can in fact...
Volatile Solvents Abuse (VSA) poses major health risks, especially for young people and those living in precarious socio-economic conditions. Such substances can in fact bring about psychoactive effects such as euphoria, and even lead to sudden death from cardiac arrhythmias, respiratory depression, myocardial infarction, laryngospasm, encephalopathy, and rhabdomyolysis. The present case report is centered around a 23-year-old man who died in prison due to inhalation of a cooker gas mixture (n-butane, propane, and isobutane) inside a plastic bag. External examination and autopsy showed non-specific signs of asphyxia associated with edema and brain swelling. Histological signs of early myocardial damage and hypoxic-ischemic injury (HII) were highlighted in the brain and cerebellum, as well as activated macrophages and anthracotic-like material in the lungs. Toxicological investigations revealed the presence of propane, isobutane and n-butane in liquids and biological samples. Besides the cardiotoxic effect, there was an asphyctic component due to the plastic bag that may have facilitated death. The assessment of cerebral HII and cardiopulmonary damage in acute cases is very important to prove death by butane inhalation. In the forensic field, it may be useful to shed more light on intoxications, deaths, and butane encephalopathies, as the latter can be mistaken for a hypoxic-ischemic encephalopathy.
Topics: Humans; Male; Young Adult; Asphyxia; Brain; Brain Edema; Butanes; Death, Sudden; Hypoxia-Ischemia, Brain; Inhalant Abuse; Lung; Myocardium; Propane
PubMed: 38484484
DOI: 10.1016/j.jflm.2024.102662 -
ACS Applied Materials & Interfaces Mar 2024Zeolitic-imidazolate framework-8 (ZIF-8), composed of a zinc center tetrahedrally coordinated with 2-methylimidazolate linkers, has garnered extensive attention as a...
Unexpectedly High Propylene/Propane Separation Performance of Asymmetric Mixed-Matrix Membranes through Additive-Assisted ZIF-8 Filler Formation: Experimental and Computational Studies.
Zeolitic-imidazolate framework-8 (ZIF-8), composed of a zinc center tetrahedrally coordinated with 2-methylimidazolate linkers, has garnered extensive attention as a selective filler for propylene-selective mixed-matrix membranes (MMMs). Recently, we reported an innovative and scalable MMM fabrication approach, termed "phase-inversion in sync with MOF formation" (PIMOF), aimed at addressing the prevailing challenges in MMM processing. In this study, we intend to investigate the effect of additives, specifically sodium formate and 1,4-butanediol, on the modification of ZIF-8 filler formation within the polymer matrix in order to further improve the separation performance of the asymmetric MMMs prepared by the PIMOF. Remarkably, MMMs prepared with sodium formate as an additive in the coagulation bath exhibited an unprecedented CH/CH separation factor of 222.5 ± 1.8 with a CH permeance of 10.1 ± 0.3 GPU, surpassing that of MMMs prepared without additives (a C3 separation factor of 57.7 ± 11.2 with a C3 permeance of 22.5 ± 4.5 GPU). Our computational work complements the experimental investigation by studying the effect of ZIF-8 nanoparticle size on the specific surface interaction energy and apertures of ZIF-8. Calculations indicate that by having smaller ZIF-8 nanoparticles, stronger interactions are present with the polymer affecting the aperture of ZIF-8 nanoparticles. This reduction in aperture size is expected to improve selectivity toward propylene by reducing the permeability of propylene. These results represent a significant advancement, surpassing the performance of all previously reported propylene-selective MMMs and most high-quality polycrystalline ZIF-8 membranes. The notably enhanced separation performance primarily arises from the formation of exceedingly small ZIF-8-like particles with an amorphous or poorly crystalline structure, corroborated by our computational work.
PubMed: 38482600
DOI: 10.1021/acsami.3c19491