Manganese Oxides with Different Morphologies In Situ Anchored onto Ti3C2Tx Nanosheets: Highly Effective Decontamination toward Sulfur Mustard Simulants.

Manganese oxides with porous structure and abundant active sites show potential in degrading sulfur mustard (HD). However, there is an interface effect between the oily liquid HD and nano oxides, and the powder is prone to agglomeration, which leads to incomplete contact and limited degradation ability. Here, we demonstrate a simple hydrothermal method for preparing MnO2/Ti3C2 composites to address this problem. The influence of morphology and crystal structure on performance are examined. Herein, flower-like MnO2 is loaded onto the surface or interlayer of Ti3C2-MXene nanosheets during in situ formation, significantly expanding the specific surface area. It also provides abundant acid-base sites and oxygen vacancies for the degradation of simulants 2-chloro-ethyl-ethyl thioether (2-CEES) without external energy, resulting in a reaction half-life as fast as 12.5 min. The relationship between structure and performance is clearly elaborated through temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure (XAFS) analyses. Based on in situ attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis, gas chromatography-mass spectrometry (GC-MS) analysis, and density functional theory (DFT) calculation, the proposed degradation pathway of the 2-CEES molecule is a synergistic effect of hydrolysis, elimination, and oxidation. Furthermore, the products are nontoxic or low toxic. Metal oxide/MXene composites are first illustrated for their potential use in degrading sulfur mustard, suggesting new insights into these materials as novel decontamination for decomposing chemical warfare agents.

Catalytic activation of peracetic acid for pelargonic acid vanillylamide degradation by Co3O4 nanoparticles in-situ anchored carbon-coated MXene nanosheets: Performance and mechanism insight.

Pelargonic acid vanillylamide (PAVA), a capsaicin-type dacryagogue agent utilized for counter-terrorism and riot control, possesses a low stimulus threshold. This characteristic can lead to environmental contamination following its application and may easily result in secondary stimulation to personnel. Cobalt-doped Ti3C2-MXene nanosheets (Co3O4/Ti3C2@C) were synthesized for the purpose of activating peracetic acid (PAA) and degrading PAVA. A carbon layer was coated on the surface of Ti3C2-MXene nanosheets to address the challenge of poor oxygen resistance in MXenes, thus preventing a significant decline in surface reactivity. The BET surface area of Co3O4/Ti3C2@C was expanded to 149.6 m2/g, significantly exceeding that of Ti3C2 (13.0 m2/g) and Co3O4 (56.4 m2/g). With 0.5 mg/mL of Co3O4/Ti3C2@C and 0.35 mM of PAA, 100 mg/L of PAVA was completely degraded within 60 min. The augmented BET surface area and the presence of more active sites confer remarkable PAA activation and catalytic degradation properties toward PAVA. Parameters such as initial pH, PAVA concentration, catalyst dosage, and PAA concentration on PAVA degradation were systematically assessed. Furthermore, the reusability and stability of the nanocomposite were substantiated through recycling tests. Radical quenching experiments and electron paramagnetic resonance analysis demonstrated the acetylperoxy radical (CH3CO3) as the primary species responsible for PAVA degradation. This research serves as an illustration of the utilization of MXene and transition metal activated PAA in wastewater treatment.

EuRBG10 involved in indole alkaloids biosynthesis in Eucommia ulmoides induced by drought and salt stresses.

Alkaloids are natural products with many important medicinal activities. To explore the mechanism of abiotic stress promoting alkaloid biosynthesis in Eucommia ulmoides, transcriptomic analysis and metabonomic analysis were used, virus-induced gene silencing (VIGS) lines of target gene were constructed. The results showed that drought and salt stress caused wilting and blackening of leaves, decreased chlorophyll level, and significantly induced MDA and relative conductivity. To resist the damage of stress to cells, the level of secondary metabolites such as alkaloids increased significantly with the extension of stress time. Transcriptomic results showed that, were. Six alkaloid related genes (AWGs) were gathered in five modules positively correlated with either salt stress or alkaloid contents by WGCNA. Results of GO and KEGG enrichment revealed that biosynthesis of alkaloid, especially indole alkaloid was induced, and degradation of alkaloid was inhibited under salt stress. Combining the results of transcriptome and metabolomics, it was suggested that EuRBG10 promotes the production of indole alkaloids and EuAMO5 inhibits the degradation of alkaloids, which may be the core mechanism of the indole alkaloid biosynthesis pathway (map00901) induced by salt stress. The results of these hub proteins were also consistent with the chordal graph of KEGG enrichment. Hub roles of EuRGB10 was checked in E. ulmoides by VIGS. Our findings provide a preliminary understanding of abiotic stress regulating secondary metabolites such as alkaloids, and propose hub genes that can be used to improve the level of bioactive components in medicinal plant.

Degradation of malathion in the solution of acetyl peroxyborate activated by carbonate: Products, kinetics and mechanism.

The degradation process of malathion in the acetyl peroxyborate (APB) solution of different APB/malathion molar ratio and in the carbonate-activated APB (APB/CO32-) solution of different pH was studied by 31P NMR technology. In the APB solution, all malathion could be degraded in 47.5 min when the molar ratio of APB/malathion was 60. CO32- could effectively activate APB to degrade all malathion in 10 min at pH of 10 when APB/malathion was 10, which was obviously higher than in APB solution. 1O2, •O2-, •OH and carbon-centered radicals (RC•) could be produced in the APB/CO32- solution, and the degradation of malathion was mainly affected by RC•. The degradation mechanism of malathion in the APB/CO32- solution was proposed based on the research results of malathion degradation process by 31P NMR and active species quenching test, which involves two steps: the first step is the oxidation of malathion to malaoxon by RC•, and the second step is the hydrolysis of malaoxon to dimethyl phosphate via hydroxyl anions nucleophilic addition.

Rapid activation of basic hydrogen peroxide by borate and efficient destruction of toxic industrial chemicals (TICs) and chemical warfare agents (CWAs).

The activation process of the B(OH)3-activated H2O2 solution and its performance toward toxic industrial chemicals (TICs) and chemical warfare agents (CWAs) were investigated to find an efficient way to destroy TICs and CWAs. 11B NMR analysis proved that B(OH)3 reacted rapidly with basic H2O2 to produce peroxoborates ([B(OH)(4-x)(OOH)x]-), and the proportional contents were closely related to the pH and temperature. 1O2 and ·O2- were generated, and their production increased exponentially with pH. TICs thioanisole and paraoxon were used as simulants of CWAs to investigate the decontamination performance and nucleophilic/oxidizing reactivity of the B(OH)3-activated H2O2. Batch experiments proved that peroxoborates acted as the oxidants for the primary oxidation of the sulfide at a pH range of 8-12 and that ·O2- was responsible for the further oxidation of sulfoxide. Paraoxon degraded through OOH--mediated SN2 displacement with high stereo-selectivity, and the degradation rate increased exponentially with pH. Mustard gas, soman, and VX degraded effectively into nontoxic products in the B(OH)3-activated H2O2 solution. A pH of 9-11 was recommended as the suitable acidity for developing the B(OH)3-activated H2O2 solution to be a candidate for nucleophilic/oxidizing decontaminant, with advantages in rapid activation and low loss rate of reactive oxygen species.

Bicarbonate-activated hydrogen peroxide and efficient decontamination of toxic sulfur mustard and nerve gas simulants.

13C NMR spectra showed that peroxymonocarbonate (HCO4-) was generated in the NaHCO3-activated H2O2 solution and pH was a key factor in its production. A cycle for the bicarbonate anion was proposed as HCO3-→HCO3 → (CO2)2*→CO2(aq)→HCO4- (H2CO4)→HCO3- (HCO3) basing on the results of NMR, electron paramagnetic resonance, chemiluminescence analysis. In this cycle, (CO2)2* was the key intermediate and (CO2)2*→2CO2+hv was the rate controlling step. Thioanisole and paraoxon, the simulants of sulfur mustard gas and nerve gas, respectively, were efficiently decontaminated by the NaHCO3-activated H2O2 solution. While HCO4- was the primary oxidant for the oxidation of thioanisole, O2- generated during the decomposition of HCO4- or H2O2 led to the secondary oxidation of the sulfide. Paraoxon was degraded in the NaHCO3-activated H2O2 solution via nucleophilic substitution by OOH- and OH-, and the degradation rate increased exponentially with increasing pH. Alkali metal ions had a catalytic effect on the degradation of paraoxon. Mustard gas and soman degraded efficiently into nontoxic products in NaHCO3-activated H2O2. A pH range of 9-10 was found to be optimum for the broad-spectrum decontamination of chemical warfare agents and other eco-toxicants using NaHCO3-activated H2O2.

Actinobacteria-Derived peptide antibiotics since 2000.

Members of the Actinobacteria, including Streptomyces spp., Kutzneria sp. Actinoplanes spp., Actinomycete sp., Nocardia sp., Brevibacteriumsp.,Actinomadura spp., Micromonospora sp., Amycolatopsis spp., Nonomuraea spp., Nocardiopsis spp., Marinactinospora sp., Rhodococcus sp., Lentzea sp., Actinokineospora sp., Planomonospora sp., Streptomonospora sp., and Microbacterium sp., are an important source of structurally diverse classes of short peptides of ∼30 residues or fewer that will likely play an important role in new antibiotic development and discovery. Additionally, many have unique structures that make them recalcitrant to traditional modes of drug resistance via novel mechanisms, and these are ideal therapeutic tools and potential alternatives to current antibiotics. The need for novel antibiotic is urgent, and this review summarizes 199 Actinobacteria compounds published since 2000, including 35 cyclic lipopeptides containing piperazic or pipecolic acids, eight aromatic peptides, five glycopeptides, 21 bicyclic peptides, 44 other cyclic lipopeptides, five linear lipopeptides, six 2,5-diketopiperazines, one dimeric peptide, four nucleosidyl peptides, two thioamide-containing peptides, 25 thiopeptides, nine lasso peptides, and 34 typical cyclic peptides. The current and potential therapeutic applications of these peptides, including their structure, antituberculotic, antibacterial, antifungal, antiviral, anti-brugia, anti-plasmodial, and anti-trypanosomal activities, are discussed.

Bacillaceae-derived peptide antibiotics since 2000.

Members of the Bacillaceae family, including Bacillus spp., Brevibacillus spp., Paenibacillus spp., Aneurinibacillus sp., and Halobacillus sp., are an important source of structurally diverse classes of short peptides of ∼ 30 residues or fewer possessing peculiar and rapid killing activity against various pathogens. Additionally, many have unique structures that enhance resistance to hydrolysis by proteases, and these are ideal therapeutic tools and potential alternatives to current antibiotics. The need for novel antibiotic lead compounds is urgent, and this review summarises 119 Bacillaceae compounds published since 2000, including 12 surfactin-like lipopeptides, 16 iturinic lipopeptides, fengycin C, 33 other cyclic lipopeptides, 26 linear lipopeptides, two thiopeptides, four 2,5-diketopiperazines, 20 typical cyclic peptides, and five standard linear peptides. The current and potential therapeutic applications of these peptides, including structure, antibacterial, antifungal, and antiviral activities, are discussed.

Cyanobacteria-derived peptide antibiotics discovered since 2000.

Members of cyanobacteria, including Moorea spp., Okeania spp., Lyngbya spp., Schizothrix spp., Leptolyngbya spp., Microcystis spp., Symploca spp., Hassallia sp., Anabaena spp., Planktothrix sp., Tychonema spp., Oscillatoria spp., Tolypothrix sp., Nostoc sp., and Hapalosiphon sp. produce an enormously diverse range of peptide antibiotics with huge potential as pharmaceutical drugs and biocontrol agents following screening of structural analogues and analysis of structure-activity relationships (SAR). The need for novel antibiotic lead compounds is urgent, and this review summarizes 78 cyanobacteria-derived compounds reported since 2000, including 32 depsipeptides, 18 cyclic lipopeptides, 13 linear lipopeptides, 14 cyclamides, and one typical cyclic peptide. The current and potential therapeutic applications of these peptides are discussed, including for SAR, antituberculotic, antifungal, antibacterial, antiviral, and antiparasitic (anti-plasmodial, antitrypanosomal and antileishmanial) activities.

Association of rs4331426 and rs2057178 with Risk of Tuberculosis: Evidence from a Meta-Analysis.

AIMS: A growing number of genome-wide association studies (GWAS) have revealed associations between single-nucleotide polymorphisms (SNPs) and susceptibility to tuberculosis (TB). However, the results of these studies have been inconclusive. This study evaluated whether the SNPs rs4331426 and rs2057178, identified by GWAS, are associated with TB susceptibility. METHODS: We performed meta-analyses for rs4331426, based on eight case-control studies which included a total of 4988 TB cases and 9041 controls; and rs2057178, based on five case-control studies, including a total of 9400 TB cases and 14,459 controls. RESULTS: Our meta-analyses indicated that both rs4331426 and rs2057178 were associated with increased risk of TB (G vs. A: odds ratio [OR] = 1.15, 95% confidence interval [CI]: 1.08-1.22 and A vs. G: OR = 0.84, 95% CI: 0.80-0.88, respectively), especially in an African subgroup. However, no significant TB association was found with rs4331426 in an Asian subgroup. CONCLUSIONS: These meta-analyses indicate that rs4331426 and rs2057178 might play a role in the risk of developing TB, especially in Africans; however, rs4331426 might not play a significant role in the risk of developing TB in Asians.

Photocatalytic decomposition of acephate in irradiated TiO2 suspensions.

In the present study, the photocatalytic degradation of acephate (O,S-dimethyl acetyl phosphoramidothioate ((CH(3)O)(CH(3)S)P(O)NHCOCH(3))) in aqueous TiO2 suspensions is extensively investigated, pertaining to the concentration of photocatalyst and substrate on degradation rate of acephate. It is found that the acephate can be degradated and mineralized. The high-degradation rate is obtained with 4 g/L concentration of TiO2. Moreover, Langmuir-Hinshelowood rate expression is employed for the degradation of acephate with adsorption constant and rate constant, i.e., 2.0 L/mmol and 0.6 mmol/(min L), respectively. The main target is to identify the products by a number of analytical techniques, such as HPLC, IC, ESR and GC-MS. Under acidic condition, the primary products are phosphorothioic acid, O,O',S-trimethyl ester (CH(3)O(CH(3)S)P(O)OCH(3)) and phosphoramidothioic acid, O,S-dimethyl ester (CH(3)O(CH(3)S)P(O)NH(2)), etc. It indicates that the decomposition of acephate begin from the destruction of C-N and P-N bonds. Subsequently, the P-S, P-O, P-C bonds may be oxidized gradually or simultaneously, and the final products such as CO(2), H(3)PO(4), were formed. About 100% sulfur atoms are transformed into SO(4)(2-) in 180 min, however; only 3% nitrogen atoms and 2% phosphorus atoms were transformed into NO(3)(-) and PO(4)(3-).

Study on solvent extraction of propionic acid from simulated discharged water in vitamin B12 production by anaerobic fermentation.

The potential of recovering propionic acid from discharged water in vitamin B(12) production by anaerobic fermentation was investigated in this paper. A primary amine, N(1923), was used as the extractant, kerosene as diluter and n-octanol as modifier. The influences of the content of N(1923) in the organic phase, the phase ratio and the pH of aqueous phase on the extraction yield of propionic acid were studied. The organic phase composition with the volume ratio was proposed of N(1923):kerosene:n-octanol as 45:35:20. Under conditions of the phase ratio (o/w) as 1:4, the pH of aqueous phase of 3.0 and after 5 min extraction, the extraction yield of propionic acid can be over 97%.