Search

Motivated by recent experiments, the laser‐induced alignment‐and‐orientation (A&O) dynamics of the prolate symmetric top CH3X (X = F, Cl, Br, I) molecules is investigated, with particular emphasis on the effect of halogen substitution on the rotational constants, dipole moments, and polarizabilities of these species, as these quantities determine the A&O dynamics. Insight into possible control schemes for preferred A&O dynamics of halogenated molecules and best practices for A&O simulations are provided, as well. It is shown that for accurate A&O ‐dynamics simulations it is necessary to employ large basis sets and high levels of electron correlation when computing the rotational constants, dipole moments, and polarizabilities. The benchmark‐quality values of these molecular parameters, corresponding to the equilibrium, as well as the vibrationally averaged structures are obtained with the help of the focal‐point analysis (FPA) technique and explicit electronic‐structure computations utilizing the gold‐standard CCSD(T) approach, basis sets up to quintuple‐zeta quality, core‐correlation contributions and, in particular, relativistic effects for CH3Br and CH3I. It is shown that the different A&O behavior of the CH3X molecules in the optical regime is mostly caused by the differences in their polarizability anisotropy, in other terms, the size of the halogen atom. In contrast, the A&O dynamics of the CH3X series induced by an intense few‐cycle THz pulse is mostly governed by changes in the rotational constants, due to the similar dipole moments of the CH3X molecules. The A&O dynamics is most sensitive to the B rotational constant: even the difference between its equilibrium and vibrationally‐averaged values results in noticeably different A&O dynamics. The contribution of rotational states having different symmetry, weighted by nuclear‐spin statistics, to the A&O dynamics is also studied. [ABSTRACT FROM AUTHOR]

The effects of ozone combined with other environmental factors remain an important topic of the research, both in connection with climate change and the possibility of using modern solutions in horticulture. In our experiment, we compared the influence of ozone (100 ppb) on photosynthesis and changes in the pigment composition of Chinese cabbage (Brassica rapa subsp. pekinensis) leaves depending on the spectral composition of light. We used white LED light (WL), a combination of red + green + blue (RGBL) with a dominant red component and white +blue (WBL) with a dominant blue component in comparison with the classic sodium lamp lighting (yellow light—YL). The values of the parameters describing the light-dependent phase of photosynthesis and the parameters of the gas exchange, as well as non-photosynthesis pigment contents, show that the spectral composition strongly differentiates the response of Chinese cabbage leaves to ozone. In general, the efficiency of photochemical reactions was the highest in YL, but after O3 fumigation, it decreased. In plants growing in WL and WBL, the increase of O3 concentration stimulated light photosynthesis reactions and led to the enhancement of transpiration, stomatal conductance and intracellular CO2 concentration. Changes in photosynthetic activity were accompanied by an increase in the content of anthocyanins and flavonols. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the photocatalytic decomposition of disinfection by-products using zinc oxide nanoparticles doped with zirconium (Zr:ZnO NPs). Zr:ZnO NPs were synthesized through mild hydrothermal method. The characterization of Zr:ZnO NPs was performed using X-ray diffraction, SEM, Fourier-transform infrared spectroscopy, dynamic light scattering, and zeta potential. Photodegradation of trihalomethanes was investigated as a disinfection by-product of chlorinated water under sunlight and UV light illumination. The optimum conditions for removal of trihalomethanes under UV irradiation was 2 h contact time, 1% Zr:ZnO NPs and nanoparticles dosage of 1.5 g/L so that the removal percentages for bromoform, bromomethane chloride, dichlorobromomethane, and total trihalomethane were 79.25%, 96.5%, 65% and 52%, respectively. No chloroform was degraded under this condition. The optimum conditions under sunlight illumination occurred at 2 h contact time, 1.5% Zr:ZnO NPs and nanoparticles dosage of 2.0 g/L occurred so that the removal percentages for chloroform, bromoform, bromomethane chloride, dichlorobromomethane, and total trihalomethane were 20%, 88.5%, 99.75%, 65%, and 67%, respectively. Investigation of the photocatalytic properties of the samples showed the positive presence of a metal as dopant to improve the photocatalytic properties of the samples, so that Zr:ZnO showed 42% higher efficiency compared with bare ZnO in photocatalytic decomposition of trihalomethanes. [ABSTRACT FROM AUTHOR]

Summary: Monitoring the diversity and structure of plant-parasitic nematode (PPN) communities together with developing appropriate control strategies can reduce the occurrence of these pathogens and other plant pests in horticultural crops. In this context a study of the abundance, frequency, diversity and distribution of PPN in horticultural soils under glasshouse conditions from the Green Belt of La Plata, Buenos Aires, Argentina, under different management systems was undertaken. Soil samples were collected from three horticultural areas with different tomato crop managements: agroecological crop (AC); organic crop with Brassicaceae soil amendments (OC); intensive conventional crop treated with methyl bromide (MeBr) (IC). The parameters evaluated were: nematode genera richness (G); Shannon-Wiener diversity index ( H ′ ) (Hutcheson's t -test was applied for this index); equitability index (E); abundance; and frequency of genera. ANOSIM and SIMPER statistical analyses were performed to find significant differences between the nematode assemblages from the different sites. A total of 14 genera of PPN were identified among the three crop sites. Members of the feeding habits categories ectoparasites, semi-endoparasites, migratory endoparasites and sedentary endoparasites were observed. Statistical analysis enabled us to characterise each site based on the composition of the nematode assemblages. Helicotylenchus , Tylenchus and Nacobbus were the most frequent and abundant genera. AC and OC showed similar values of richness and diversity; the crop treated with MeBr (IC) showed the lowest diversity of PPN. [ABSTRACT FROM AUTHOR]

Carbofuran is one of the most commonly used N-methylcarbamate-based pesticides and is excellent for controlling pests; however, carbofuran also causes soil and water pollution. Although various studies have been conducted on the bioremediation of pesticide-contaminated soil, the changes occurring in the metabolome during the bioremediation of carbofuran are not fully understood. In this study, the intracellular and extracellular metabolites of the Chryseobacterium sp. BSC2-3 strain were analysed during carbofuran degradation by using a liquid chromatography–mass spectrometry-based metabolomics approach. We found that the BSC2-3 strain extracellularly transformed carbofuran into 3-hydroxycarbofuran. Intracellular metabolite analysis revealed that carbofuran mainly affected aminobenzoate degradation, ubiquinone and terpenoid-quinone biosynthesis, and arginine and proline metabolism. Carbofuran especially affected the metabolic pathway for the degradation of naphthalene and aminobenzoate. Metabolomics additionally revealed that the strain produces disease resistance inducers and plant growth regulators. We also identified the genes involved in the production of indole-3-acetic acid, which is one of the most active auxins. Overall, we identified the metabolic changes induced in carbofuran-degrading bacteria and the genes predicted to be responsible for the degradation of carbofuran. [ABSTRACT FROM AUTHOR]

Methyl bromide (CH3Br) is an ozone depleting trace gas that is now mainly emitted from natural sources. Roughly 80% of anthropogenic production of CH3Br was phased‐out in response to the Montreal Protocol on Substances that Deplete the Ozone Layer beginning in 1999 and atmospheric levels of CH3Br have declined considerably since. Here we use surface measurements of CH3Br from NOAA's global air sampling network, along with a six‐box atmosphere/ocean model to explore interannual variability in atmospheric CH3Br mole fractions. We find that CH3Br mole fractions are strongly correlated with the El Niño Southern Oscillation (ENSO) phenomenon, but variability in winds, sea surface temperature, and biological production during ENSO are unlikely to drive the observed changes in atmospheric CH3Br directly. Rather, the results indicate that ENSO‐driven changes to biomass burning are an important cause of the observed interannual CH3Br variability. Plain Language Summary: Methyl bromide (CH3Br) is a trace gas known to destroy stratospheric ozone. Atmospheric mole fractions of CH3Br have declined substantially over time because of Montreal Protocol controls on production of this ozone‐depleting gas. What remained unexplained were the substantial temporary variations observed in the measurement record. Here we find that those variations are related to El Niño Southern Oscillation (ENSO) events, and the increased burning during the warm phase of ENSO is determined to be the most likely cause of these interannual changes. Key Points: Interannual variability in the global atmospheric methyl bromide (CH3Br) mole fraction is strongly correlated with the El Niño Southern Oscillation (ENSO) phenomenonChanges in the ocean (sea surface temperature and winds) during ENSO are unlikely to cause the observed variability in atmospheric CH3Br mole fractionThe majority of interannual variability in atmospheric CH3Br mole fraction is explained by ENSO‐driven fire emissions [ABSTRACT FROM AUTHOR]

Methyl bromide is a stratospheric ozone‐depleting substance with both natural and anthropogenic sources. The global budget of methyl bromide has never been fully understood as evidenced by the significant budget gap between the bottom‐up source estimates and calculated atmospheric losses. Atmospheric methyl bromide levels have declined significantly since Phase‐out under the Montreal Protocol began in 1999, and the atmosphere appears to have reached a new steady state during the past five years. Here, we reassess the global methyl bromide budget utilizing the 25‐year record of atmospheric methyl bromide measurements from the National Oceanic and Atmospheric Administration Global Monitoring Laboratory global flask network and a zonal 6‐box coupled global ocean/atmosphere model. Model inversions were used to estimate the total emissions required to account for the observed atmospheric methyl bromide levels. From 1995 to 2019, global land‐based emissions (natural and anthropogenic) declined from about 120 to 85 Gg y−1 and net ocean emissions increased from −5 to +5 Gg y−1. There remains an imbalance between the bottom‐up estimates of terrestrial sources and the inversion result. Based on the timing, magnitude, and spatial distribution of the imbalance we partition it into (a) a persistent or time invariant source located primarily in the tropics, and (b) a smaller time‐varying component that scales with the anthropogenic source during phase‐out. We hypothesize that the persistent source is likely natural and the time variant component is an artifact resulting from a slight underestimation of anthropogenic emissions. Plain Language Summary: Methyl bromide is an ozone‐depleting gas for which production is globally controlled under the fully amended and adjusted Montreal Protocol. As a result, atmospheric methyl bromide levels have declined dramatically since 1999 as measured by the National Oceanic and Atmospheric Administration Global Monitoring Laboratory flask air network. The change in atmospheric methyl bromide abundance provides an opportunity to re‐examine our understanding of the global budget. We use a coupled ocean/atmosphere model to estimate the change in emissions required to explain the observed atmospheric changes. The study suggests that anthropogenic emissions may have previously been slightly underestimated and that there remain significant sources of unknown origin, located mainly in the tropics. Key Points: As a result of the Montreal Protocol phase‐out, atmospheric methyl bromide declined over the past two decades and has recently stabilizedThe ocean saturation state for methyl bromide has increased and the oceans are a small net source to the atmosphereAn imbalance between the known sources and losses of atmospheric methyl bromide remains, requiring additional emissions in the tropics [ABSTRACT FROM AUTHOR]

A screening test was carried out using ethanedinitrile (EDN) as a candidate fumigant to replace methyl bromide for efficacy against a selection of forest pests, including the pinewood nematodes (Bursaphelenchus xylophilus) and four tree pathogens: Heterobasidion annosum, Geosmithia morbida, Phytophthora ramorum and Ceratocystis fagacearum. Two EDN concentrations were tested: 50 and 100 g/m3 at two different temperatures and six exposure times. In our tests, EDN was very efficient in killing pathogens in all test parameter combinations, including short exposure times and lower concentration, apart from C. fagacearum surviving short 1 h exposure and G. morbida surviving after 1 and 3 h of exposure. Pinewood nematodes in the small wood blocks were effectively killed at all test parameter combinations. In log sections where deeper nematode infestations were present, nematode survivors at 50 and 100 g/m3 after 1, 3, and 6 h exposure were observed. This suggests that the fumigant was not efficacious at lower exposure times, while penetrating log sections. Both 50 and 100 g/m3 dosages were effective after 24 h exposure, indicating that longer retention times are required to effectively kill pine wood nematodes in deeper wood sections. The lower temperature did not affect the efficacy of EDN. This indicates that EDN could successfully eradicate pinewood nematodes in logs over 24 h of exposure, or even less exposure time, at targeted concentrations. [ABSTRACT FROM AUTHOR]

A paddy soil, with microbial biomass considerably reduced by chloroform fumigation, was treated with low-crystalline ferrihydrite and high-crystalline goethite and with 13C-labeled acetate. In the first 10 days of the incubation, CH4 was produced mainly from the added acetate (56‒91%). After day 30, however, 3‒11% of the total CH4 emissions originated from the added acetate. Chloroform fumigation reduced the microbial biomass by 43‒87%, leading to the decrease in the CH4 emission from the fumigated soil for 352‒1127 times compared to that from the unfumigated soil. Acetate only contributed to 0‒6% of the total CH4 emission from the fumigated soil during the entire incubation period. Thus, chloroform fumigation largely reduced the abundance of methanogens, and the reduction in the abundance of acetotrophic methanogens was high. Iron oxide additions reduced CH4 emissions from the added acetate and from other sources. The reduction was stronger in the fumigated soil compared to that in the unfumigated soil because the lower abundance of methanogens in the fumigated soil decreased the competition for substrates with iron reducers. The effect of ferrihydrite on CH4 emission from non-acetate sources was stronger than that of goethite before day 6; however, this effect became weaker thereafter, because of the reduced number of reactive sites after acetate sorption by ferrihydrite. We conclude that the marked reduction in the microbial biomass, and especially methanogens, decreased the methane production, changed the CH4 sources, and increased the relative effects of iron oxides on CH4 production. [ABSTRACT FROM AUTHOR]

Chloropicrin, ethyl-bromide, and methyl-bromide are the three primary chemical malignant anatomical stuff found in poultry feeds. The risk of cancer is found in some cases for the association of this stuffs. Hence, an effective detection method is necessary for identifying this malignant stuff. Here, we have suggested a square core-based PCF sensor that is operable in the 1–2 THz regime. The well-known polymer zeonex is selected as the hosting material and the investigation is carried out by the FEM method. After completing the numerical analyses, a higher sensitivity of 94.6%, 92.7%, and 93.3% is, respectively, obtained for chloropicrin, ethyl-bromide, and methyl-bromide. Also, an imperceptible CLoss and effective material loss are obtained from this simulation. Again, the measurements of the effective area, numerical aperture, core power fraction, and propagation constant are done for the three malignant stuff. The present existing technologies confirm the manufacturing chances of this recommended sensor. Our proposed sensor can be a deft aspirant in the areas of poisonous chemical sensing along with various application areas of bio-sensing. [ABSTRACT FROM AUTHOR]

Background: The Occupational Safety and Health Administration (OSHA) regulates exposures to hazardous chemicals in workplace air. When contemporaneous exposure measurements are unavailable, retrospective analysis of biomarkers could provide valuable information about workers' exposures. Methods: Single‐compartment pharmacokinetic (PK) models were created to relate the concentration of a chemical in the air to the concentration of the chemical or its metabolite in workers' blood or urine. OSHA utilized the PK models in investigations of three fatal incidents in which workers were exposed to nickel carbonyl, methyl bromide, or styrene. To obtain the minimum plausible estimate of each exposure, OSHA used conservative assumptions about parameters such as workers' inhalation rates, baseline levels of biomarker, and chemicals' volumes of distribution. Results: OSHA analyzed a worker's urinary nickel concentration and concluded that his 8‐h time‐weighted average exposure to nickel carbonyl was at least 0.06 mg/m3. Analysis of a worker's postexposure, premortem blood bromide level revealed that his exposure to methyl bromide was at least 181 mg/m3. Post‐mortem blood styrene measurements suggested that a third worker's exposure to styrene was at least 625 mg/m3. These exposures exceeded OSHA's permissible exposure limits of 0.007 mg/m3 for nickel carbonyl, 80 mg/m3 for methyl bromide, and 426 mg/m3 for styrene. OSHA successfully cited the three employers for violations of chemical exposure limits. Conclusions: Analysis of biomarkers via PK modeling enables retrospective evaluations of workers' acute exposures to hazardous chemicals. These techniques are useful to occupational regulators who assess employer compliance with mandatory exposure limits. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sulfur Angelicae Dahuricae Radix (Baizhi) is a common medicinal herb in Asian countries. A practical protocol combining metabolomics, pharmacology, and cytotoxicity was developed to comprehensively evaluate the influence of sulfur-fumigation on the quality of Baizhi. Furocoumarins could be transformed into sulfur-containing compounds during the sulfuring process, among which 1 and 3 were purified with relatively high abundance and identified as 3,4-dihydrobyakangelicin-4-sulfonic acid and (4 R ,12 S)-3,4-dihydrooxypeucedanin hydrate-4-sulfonic acid (OXH-S), respectively. OXH-S was found to be an addition product of sulfite and oxypeucedanin hydrate (OXH-N). Then, the cytotoxicity and anti-inflammatory activity of OXH-N, OXH-S, and water extracts of sulfured (extraction-S), and unsulfured Baizhi (extraction-N) were evaluated. OXH-S and extraction-S were less toxic than OXH-N and extraction-N, respectively. A comparison of OXH-N with OXH-S and extraction-N with extraction-S showed no significant differences in anti-inflammatory activity. These results suggest that sulfur fumigation can reduce toxicity and does not influence the anti-inflammatory activity of Baizhi, even after chemical composition changes. The proposed protocol based on marker screening, pharmacology, and safety evaluation provides a scientific basis for the standardization and regulation of sulfured Baizhi and other medical materials. [ABSTRACT FROM AUTHOR]

Catalysts based on individual precious metals on carbon‐ and oxide‐based carriers have shown remarkably selective behavior in the hydrodebromination of CH2Br2 to CH3Br, an important transformation within halogen‐mediated methane upgrading processes. However, the high susceptibility of the active phase to coking and to sintering, which cannot be overcome by controlling the nuclearity of the metal species, hinders their practical implementation. Herein, a platform of carbon‐supported Ir−Ru catalysts with distinct metal ratios at comparable metal nanoparticle size (ca. 1.0 nm) was adopted to systematically study the effects of a second metal on reactivity and stability. Catalytic tests reveal ruthenium‐doped iridium nanoparticles as the first system that combines high CH3Br selectivity (up to 93 %) with unprecedented stability, outperforming any of the previously reported catalysts. This superior performance was rationalized by the intimate interaction between the two metals, forming ruthenium‐poor surface alloys, which enable suppressing deactivation mechanisms as well as over hydrogenation/coking pathways. [ABSTRACT FROM AUTHOR]

Methyl bromide has been banned worldwide because it causes damage to the ozone layer and the environment. To find a substitute for methyl bromide, the relationships among fumigation, plant growth, and the microbial community in replant soil require further study. We performed pot and field experiments to investigate the effects of dazomet fumigation on soil properties and plant performance. Changes in soil microbial community structure and diversity were assessed using high-throughput sequencing, and plant physiological performance and soil physicochemical properties were also measured. Dazomet fumigation enhanced photosynthesis and promoted plant growth in replant soil; it altered soil physical and chemical properties and reduced soil enzyme activities, although these parameters gradually recovered over time. After dazomet fumigation, the dominant soil phyla changed, microbial diversity decreased significantly, the relative abundance of biocontrol bacteria such as Mortierella increased, and the relative abundance of pathogenic bacteria such as Fusarium decreased. Over the course of the experiment, the soil microbial flora changed dynamically, and soil enzyme activities and other physical and chemical properties also recovered to a certain extent. This result suggested that the effect of dazomet on soil microorganisms was temporary. However, fumigation also led to an increase in some resistant pathogens, such as Trichosporon, that affect soil function and health. Therefore, it is necessary to consider potential negative impacts of dazomet on the soil environment and to perform active environmental risk management in China. [ABSTRACT FROM AUTHOR]

Methyl bromide (CH3Br) and methyl chloride (CH3Cl) are major carriers of atmospheric bromine and chlorine, respectively, which can catalyze stratospheric ozone depletion. However, in our current understanding, there are missing sources associated with these two species. Here we investigate the effect of copper(II) on CH3Br and CH3Cl production from soil, seawater and model organic compounds: catechol (benzene-1,2-diol) and guaiacol (2-methoxyphenol). We show that copper sulfate (CuSO4) enhances CH3Br and CH3Cl production from soil and seawater, and it may be further amplified in conjunction with hydrogen peroxide (H2O2) or solar radiation. This represents an abiotic production pathway of CH3Br and CH3Cl perturbed by anthropogenic application of copper(II)-based chemicals. Hence, we suggest that the widespread application of copper(II) pesticides in agriculture and the discharge of anthropogenic copper(II) to the oceans may account for part of the missing sources of CH3Br and CH3Cl, and thereby contribute to stratospheric halogen load. Halogenated compounds impact stratospheric ozone. This study suggests agricultural application of Cu(II) chemicals induces abiotic production of methyl bromide and methyl chloride from soil and seawater, contributing to the atmospheric halogen load. [ABSTRACT FROM AUTHOR]

Candida albicans is a major opportunistic pathogen of humans. It can grow as morphologically distinct yeast, pseudohyphae and hyphae, and the ability to switch reversibly among different forms is critical for its virulence. The relationship between morphogenesis and innate immune recognition is not quite clear. Dectin-1 is a major C-type lectin receptor that recognizes β-glucan in the fungal cell wall. C. albicans β-glucan is usually masked by the outer mannan layer of the cell wall. Whether and how β-glucan masking is differentially regulated during hyphal morphogenesis is not fully understood. Here we show that the endo-1,3-glucanase Eng1 is differentially expressed in yeast, and together with Yeast Wall Protein 1 (Ywp1), regulates β-glucan exposure and Dectin-1-dependent immune activation of macrophage by yeast cells. ENG1 deletion results in enhanced Dectin-1 binding at the septa of yeast cells; while eng1 ywp1 yeast cells show strong overall Dectin-1 binding similar to hyphae of wild-type and eng1 mutants. Correlatively, hyphae of wild-type and eng1 induced similar levels of cytokines in macrophage. ENG1 expression and Eng1-mediated β-glucan trimming are also regulated by antifungal drugs, lactate and N-acetylglucosamine. Deletion of ENG1 modulates virulence in the mouse model of hematogenously disseminated candidiasis in a Dectin-1-dependent manner. The eng1 mutant exhibited attenuated lethality in male mice, but enhanced lethality in female mice, which was associated with a stronger renal immune response and lower fungal burden. Thus, Eng1-regulated β-glucan exposure in yeast cells modulates the balance between immune protection and immunopathogenesis during disseminated candidiasis. Author summary: Candida albicans is a major cause of invasive candidiasis, which has a high mortality rate. It is a constituent of the human microbiome and found in the gastrointestinal and genitourinary tracts of most healthy individuals. C. albicans is able to switch reversibly between yeast and hyphae in response to environmental cues, and the ability to switch is essential for virulence. The innate immune response is critical for host defense against fungal infections. However, the relationships between morphogenesis, host immune recognition and immune protection are not fully understood for C. albicans. This study shows that β-glucan is masked by two highly expressed yeast proteins, the endo-1,3-β-glucanase Eng1 and Yeast Wall Protein 1 Ywp1. β-glucan is exposed during yeast-to-hypha transition. Eng1 level is also dynamically regulated in response to different carbon sources and antifungal drugs. The eng1 mutant modulates virulence in the mouse model of hematogenously disseminated candidiasis in a sex and Dectin-1-dependent manner. Our data reveal that the level of β-glucan exposure in C. albicans is highly controlled to modulate the balance between immune protection and immunopathogenesis during disseminated candidiasis. [ABSTRACT FROM AUTHOR]

In the present study, five Penicillium species, namely, P. italicum, P. expansum, P. simplicissimum, P. oxalicum, and P. citrinum, were identified using ITS (internal transcribed spacer) and β-tubulin markers and screened for their in vitro antagonistic potential against a soil-borne fungal pathogen, Macrophomina phaseolina, in a dual-culture plate assay. Among all the tested strains, P. italicum showed the highest antagonistic potential against M. phaseolina by reducing its growth up to 57% over control, followed by P. citrinum (42%), P. simplicissimum (21%), P. expansum (11%), and P. oxalicum (9%). In order to find out the mechanism of action of P. italicum, genomic DNA of M. phaseolina was exposed to P. italicum secondary metabolites. The findings showed that these metabolites completely degraded the fungal DNA after the 48-h incubation period. To further explore the antifungal mechanism of action of P. italicum, chloroform and ethyl acetate fractions of its metabolites were subjected to gas chromatography–mass spectrometry (GC-MS) analysis. The major compounds identified in these fractions were 9,12-octadecadienoic acid (Z,Z)- (25.19%), decane (19.72%), dodecane (18.05%), benzene, nitro- (14.62%), benzene, 1,3,5-trimethyl (14.37%), benzene, 1,4-diethyl (11.62%), 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester (9.02%), and 1-nonadecene (8.99%), which could be responsible for control of M. phaseolina growth. [ABSTRACT FROM AUTHOR]

Copper is an important component of methanotrophic physiology, as it controls the expression and activity of alternative forms of methane monooxygenase (MMO). To collect copper, some methanotrophs secrete a chalkophore-or copperbinding compound called methanobactin (MB). MB is a ribosomally synthesized posttranslationally modified polypeptide (RiPP) that, after binding copper, is collected by MbnT, a TonB-dependent transporter (TBDT). Structurally different forms of MB have been characterized, and here, we show that different forms of MB are collected by specific TBDTs. Further, we report that in the model methanotroph, Methylosinus trichosporium OB3b, expression of the TBDT required for uptake of a different MB made by Methylocystis sp. strain SB2 (MB-SB2) is induced in the presence of MB-SB2, suggesting that methanotrophs have developed specific machinery and regulatory systems to actively take up MB from other methanotrophs for copper collection. Moreover, the canonical "copper switch" in M. trichosporium OB3b that controls expression of alternative MMOs is apparent if one of the two TBDTs required for MBOB3b and MB-SB2 uptake is knocked out, but is disrupted if both TBDTs are knocked out. These data indicate that MB uptake, including the uptake of exogenous MB, plays an important role in the copper switch in M. trichosporium OB3b and, thus, overall activity. Based on these data, we propose a revised model for the copper switch in this methanotroph that involves MB uptake. [ABSTRACT FROM AUTHOR]

The fumigant pesticide methyl bromide (MB) is no longer used in most countries due to its carcinogenic effects. It is followed by carbon bisulfide and chloropicrin which are the most effective liquid synthetic chemicals in pesticide formulations. They are converted to gas to penetrate soil particles and eliminate plant pests such as insects, weeds, and causal plant diseases of viruses, bacteria, fungi, and nematodes under greenhouse, field and storage conditions. These fumigants are non specific pesticides and highly hazardous to humans, environmental resources, and deplete the ozone layers. Furthermore, increasing the cost of crop production by inceasing the amount of pesticides treatments was increased the cost of research on the alternatives of green pesticides from eco-friendly agents, natural organic soil amendments of organic wastes, green manure, biofumigation crops, compost, and essential oils, as well as formulations, are examples of this. Organic fumigants that are non toxic, non-residual, highly degradable and decomposable are available as eco-friendly alternatives to chemical pesticides to manage soil borne pests and diseases of plants. This article summarizes the development of applicable eco-friendly formulations which use natural organic materials to disinfest soil in order to reduce plant diseases caused by soil- -borne pathogens. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In utilizing glycerol to produce 1,3‐propanediol by microbial fermentation, the problems of low utilization rate and poor production performance need to be addressed. Based on the analysis of a mathematical model for 1,3‐propanediol production from glycerol by Klebsiella pneumoniae, this study theoretically investigated the effects of the dilution rate and the initial glycerol concentration in a two‐stage fermentation process and the feasibility of applying the feedback control methods. First, the optimal operation conditions of initial glycerol concentration and dilution rate were obtained. Through the use of feedback control theory, a control strategy for dilution rate was designed and optimized to shorten the settling time (time required for fermentation to reach stability) from 60.92 to 36.68 h for the first reactor, and from 53.66 to 22.68 h for the second reactor. In addition, the yield of 1,3‐propanediol in both two reactors reached up to 0.5 g·g−1. The simulation results indicated that the feedback control strategy for dilution rate increased the product concentration, reduced the residual glycerol in the fermentation broth, and greatly improved the performance of the fermentation. A feeding strategy of automatic control for dilution rate has been established and will be applied as an effective guiding scheme in automatic continuous fermentations for production of 1,3‐propanediol. [ABSTRACT FROM AUTHOR]

Ethyl formate (EF) was evaluated as a potential alternative to methyl bromide (MB) for phytosanitary treatment of imported citrus fruit in the Republic of Korea. Planococcus citri (Risso) (Hemiptera: Pseudococcidae), a mealybug with known tolerance against EF and MB, was used as a representative pest to test efficacy of the two fumigants against eggs. In nine commercial-scale refrigerated container (67.5 m3) trials using imported orange, lemon and grapefruit, EF applied at the currently approved dose for citrus (70 g·m-3 at 5°C for 4 h, developed for Aspidiotus excisus Green (Hemiptera: Diaspididae), a species less EF tolerant than P. citri) resulted in 76.9–98.3% mortality of P. citri eggs. The EF treatment did not affect the sugar content or the color of peel and pulp of the treated fruit. When oranges were treated according to the current MB (64 g·m-3 at >5°C for 2 h) or EF treatment guidelines, the concentration of fumigant around the fruit fluctuated between 9.4 and 185.1 ppm for EF and 9.5–203.0 ppm for MB during the 72-h post-fumigation processes (venting [0–2 h], transportation to storage [2–24 h], and storage periods [24–72 h]) with both EF and MB maintained between 10 and 100 ppm during the storage period. Considering the efficacy of EF, its apparent lack of phytotoxicity, and its more manageable threshold limit value for humans (100 ppm EF compared to 1 ppm MB for an 8-h time weighted average exposure), our results suggest that EF may be a promising alternative to MB for the phytosanitary treatment of imported citrus in Korea. [ABSTRACT FROM AUTHOR]

Studies were conducted with ozone gas fumigation under vacuum as a methyl bromide alternative against life stages of coffee berry borer (CBB) Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), and the urediniospores of coffee leaf rust (CLR), Hemileia vastatrix Berkeley & Broome (Basidiomycota: Pucciniales) in green coffee, Coffea spp. L. Fumigation with 10,000 ppm O3 gas under −25.4 mm Hg vacuum1 at 13.0 ± 3.0°C for 6.0 h killed all CBB larvae, pupae, and adults, but did not kill all CBB eggs (~15% survival). Mortality of CLR urediniospores was 100% within the first hour of the 6-h fumigation. Ozone fumigation had no adverse effects on coffee quality. Results indicated that CBB adult hitchhikers may be the only target life stage of quarantine concern, and additional studies focused on this stage. CBB adult survival and reproduction decreased significantly at moisture contents ≤20%, and F1 generation survival did not occur in green coffee at moisture contents ≤15%. As the international standard for green coffee moisture content is 9–12%, adult CBB should not survive or reproduce in exported dry green coffee. Standard industry processing of harvested coffee cherries to the green coffee stage using either mechanical- or sun-drying eliminated CBB infestations from the field. A systems approach is recommended for exporting green coffee to control CBB and CLR that includes eliminating CBB life stages with standard processing methods, reducing moisture content to 9–12% to prevent egg deposition, survival or reproduction, and O3 fumigation to ensure quarantine security against potential CBB adult hitchhikers. [ABSTRACT FROM AUTHOR]

The Glyphodes pyloalis Walker, is considered as the most destructive insect pest of mulberry. The current study incorporated Artemisia annua essential oils loaded mesoporous materials including pure silica MCM-41 and clinoptilolite zeolite. The procedure prolonged the stability and fumigant toxicity compared to crude essential oil by 23 days. A nanoemulsion of A. annua essential oil with tween 80 and water via ultrasonication showed moderate larvicidal activity. The estimated LC50 values of 0.380% and 0.511% W/V in oral toxicity and 3.043 and 4.034 μL/L air in fumigant toxicity were recorded. The fumigant toxicity constancy of this formulation from essential oil was observed for up to 20 days. The current results are indicative of valuable potential of A. annua essentials oil in controlling the lesser mulberry pyralid based on environmentally friendly points. [ABSTRACT FROM AUTHOR]

Inert dust insecticides (IDIs) can make a significant contribution to Integrated Pest Management (IPM) programs of stored grain providing insect control and preserving grain quality during storage. Unlike chemical-based insecticides, IDIs are unaffected by even high summer temperatures and maintain efficacy for many months rather than the days or weeks of their chemical counterparts. Their three main applications are structural treatment of empty storage facilities and grain- handling machinery; commodity capping and surface admixture treatments. For structural treatment, IDIs can be sprayed on surfaces as dust or aqueous slurry. IDIs can be applied along with aeration, temperature control and flow-through fumigation like phosphine or other gaseous insecticides in the form of capping treatments and in surface admixture treatments. IDI treated commodities have been approved by organic grower associations. [ABSTRACT FROM AUTHOR]

COVID-19 represents a significant stress factor for all people worldwide due to several factors, including quarantine, lockdowns, fear of contagion, deaths, and other traumatic events. However, the healthcare workers (HCWs) have paid the higher price of this pandemic in terms of fatalities, contagions, and psychological well-being. Studies suggest that this particular population is at increased risk of developing a severe post-traumatic stress disorder (PTSD). The early diagnosis and timely treatment of PTSD in HCWs may restore well-being and significantly impact health services functioning, reducing burnout, days spent far from work, disrupted personal and team empowerment, and worse job performances. In the present article, we reported on two cases of HCWs directly involved in the treatment of COVID-19 patients who showed selective serotonin reuptake inhibitor-resistant PTSD, which was successfully treated with extended-release trazodone TRZ ContramidⓇ add-on. [ABSTRACT FROM AUTHOR]

Featured Application: The objective of the work is to assess alternatives to methyl bromide such as ethyl formate and phosphine for the control of insect pests in the quarantine process. Methyl bromide (MB) has been used in a wide range of applications, but since it was determined to be an ozone-depleting compound, it has only been used for pre-shipment and quarantine purposes in trade. Phosphine (PH3) is currently the ideal fumigant as an MB alternative worldwide. However, the development of PH3 resistance in the target insect pest and longer PH3 fumigation treatment times raise questions about the continued use of PH3. This study attempted to shorten treatment time via combination treatment with ethyl formate (EF). Planococcus citri was used as the main quarantine pest in Korea, and the acute toxicity of EF, PH3, and EF + PH3 was determined at every developmental stage. EF treatment at 4 h showed LCT99 values of 45.85~65.43 mg∙h/L, and PH3 treatment at 20 h showed that of 0.13~0.83 mg∙h/L depending on the developmental stage. The efficacy of PH3 decreased after reducing the treatment time, but synergistic effects were observed at all stages of development of P. citri when both fumigants were used simultaneously for 4 h. After combined treatment, dihydrolipoyl dehydrogenase expression and the production of two phospholipids, PI(O-16:0) and PC(18:2), were significantly reduced in treated P. citri adults compared with the control. Therefore, combined treatments might be key to reducing the treatment time and resistance of PH3 in the field. [ABSTRACT FROM AUTHOR]

BACKGROUND Methyl bromide is an ozone depleting substance and is still being used for quarantine treatment of wood products and logs. Ethanedinitrile (C2N2) is a new potential alternative fumigant and has been investigated as a timber fumigant because it has shown better penetration through timber and responds fast to insects and nematodes. This article reports on laboratory and commercial‐scale trials with C2N2 for important wood destroying pests namely Tomicus piniperda (Pine bark beetle) adults, Hyphantria cunea (Fall webworm) lavae, Reticulitermes speratus (Japanese Termite) adults and Cryphalus fulvus (Scolytidae) (Yellow minute bark beetle) which naturally infests pine logs. RESULTS: Tomicus pi:niperda adults were more tolerance than H. cunea lavae and R. speratus adults with lethal concentration × time affecting 99% mortality (LCt99) values of 27.84, 7.49 and 3.30 g h m−3, respectively. Ethanedinitrile shows exceptionally high toxicity to adult R. speratus which was almost 26 times more toxic than methyl bromide. The complete control of larvae and adults stages of C. fulvus was achieved at concentration × time (Ct) products from 89.6 g h m−3 in a 6–8 L fumigation chamber. Temperature‐depending trials on C. fulvus were conducted with C2N2 doses of 30 at 21 ± 6 and 40 g m−3 at 9 ± 3 and 2 ± 2 °C for 24 h. The Ct products of 182.2, 227.8 and 268.6 g h m−3 were obtained and C. fulvus was completely controlled at all tested temperatures. CONCLUSION: Ethanedinitrile could offer quarantine treatment for wood products and logs for the control of wood destroying insect pests and termites. [ABSTRACT FROM AUTHOR]

Nematode and disease resistant rootstocks have been developed for many vegetable crops including tomato, eggplant, melon, watermelon, and cucumber and are being utilized by an increasing number of growers. Grafting commercially desirable vegetable scions on nematode and disease resistant rootstocks has been significantly stimulated by the need for an alternative to banned soil fumigation with methyl bromide, which had been the primary method for managing soil‐borne nematodes, diseases, and weeds. Rootstocks resistant to root‐knot nematodes (Meloidogyne spp.) and diseases including Fusarium wilt, Fusarium crown and root rot, Verticillium wilt, bacterial wilt, Southern blight, and sudden wilt have been developed and many are available commercially. New technologies such as transcriptomics, identification of differentially expressed genes, transgene rootstocks, and RNAi silencing are being used in the development of vegetable rootstocks which are resistant to pests, salt tolerant, and heat and cold tolerant. Overall, grafting has proven to be a successful and environmentally safe method for managing root‐knot nematodes and soil‐borne diseases by reducing infection, disease development, and inoculum build‐up in the soil, which is especially important for growth of healthy subsequent crops. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Mushroom fly, Lycoriella mali (Diptera: Sciaridae), is the primary pest in imported mushrooms. The amount of Tricholoma matsutake imported from China increases every fall when it is harvested. When importing T. matsutake, disinfestation using methyl bromide (MB) or phosphine (PH3) is performed to prevent the introduction of L. mali. However, MB will be phased out due to ozone-depletion, chronic toxicity to workers, and residual issues. PH3 fumigation in mushroom disinfestation requires a long exposure time (24 h). In this study, we used ethyl formate (EF), which can replace MB and reduce exposure time. The efficacy of EF, PH3 and EF + PH3 on L. mali was evaluated. Using 4-h EF fumigation at 5 °C, the 3rd and 4th instar was the most tolerant stage in terms of 99% killed lethal concentration × time products (LCt99%). When 4-h EF fumigation at 5 °C was applied on all stages of L. mali, the LCt99% values of EF were 73.1 g h/m3 to the 1st and 2nd instar, 112.9 g h/m3 to the 3rd and 4th instar, 68.9 g h/m3 to pupae, and 20.1 g h/m3 to adult. It was confirmed that combination treatment with EF + PH3 had a synergistic effect on L. mali. The LCt99% of EF + 0.5 g/m3 of PH3 to the 3rd and 4th instar was 48.3 g h/m3. When only 140 g/m3 of EF was applied for 4 h at > 5 °C and 35 g/m3 of EF + 0.5 g/m3 of PH3 for 4 h at > 5 °C in commercial trials containing T. matsutake, proven efficacy (100%) on L. mali was confirmed. In the case of EF treatment only, phytotoxic damage occurred due to high Ct products, and there was no phytotoxic damage in combination treatment with EF + PH3. This study provides a new guideline for EF + PH3 combination treatment within a shorter exposure time (4 h) than existing PH3 treatment (24 h) and replacement of MB use. [ABSTRACT FROM AUTHOR]

The present investigation involves rapid and efficient synthesis of a series of some novel derivatives for 1,2-bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)-ethan-1-ol 5–21 using dl-malic acid under microwave (MW) irradiation. Reaction with several alkylating agents such as epichlorohydrin, 3-chloropropanol, (2-acetoxyethoxy) methyl bromide, propargyl bromide and chloroacetamide was studied. Not only higher yields but also shorter reaction times were observed in comparison with thermal procedure. Structures of the realized products have been established on the basis of their 1H/13C NMR, IR, elemental analysis and correlation experiments. It is well known that 1,2,4-triazole ring systems are famous for their antifungal activities, so the synthesized compounds were screened for their antifungal activities. The minimal inhibitory concentration (MIC) of the screened compounds exhibited prominent results against Gram (+ ve) and Gram (− ve) and antifungal activities comparing with the standard drugs. [ABSTRACT FROM AUTHOR]

Denture stomatitis (DS) is one of the most common infectious diseases affecting edentulous patients, due to the colonization of candida albicans on the fitting surface dentures. Despite its multifactorial aetiology, most of the attempts at addressing this problem have been dedicated to the development of dentures or associated materials with antimicrobial activity. This review aims to provide an overview of the published literature on the development of denture base materials with antimicrobial activity and their properties. The published literature indicates that antimicrobial activity to the denture base materials was induced either by physically blending or chemically copolymerizing the antimicrobial agents into the polymeric matrix. A variety of materials such as chlorhexidine, silver and silver- based compounds, titanium dioxide nanoparticles (TiO2NP), and quaternary ammonium salts (QAS), etc., have been physically blended with the denture base materials. Antimicrobial monomers such as methacryloyloxy dodecylpyridinium bromide (MDPB), methacryloyloxy undecylpyridinium bromide (MUPB), quaternary ammonium (QA), dimethylaminododecyl methacrylate (DMADDM), 2-tert-butylaminoethyl methacrylate (TBAEMA), methacryloxylethylcetyl dimethyl ammonium chloride (DMAE-CB), acrylamide monomer (AAm), 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB), 2-methacryloxylethyl hexadecyl methyl ammonium bromide (MAE-HB), 2- dimethyl-2-dodecyl-1-methacryloxyethyl ammonium iodine (DDMAI) and 2-Dimethyl-2-hexadecyl-1-methacryloxyethyl ammonium iodine (DHMAI), etc. have been copolymerized with methyl methacrylate to impart antimicrobial activity. These attempts have shown promising antimicrobial activity against C. albicans. However, significant differences in their antimicrobial activity as well as in their properties were noted. Incorporation of antimicrobial monomers to PMMA denture base resin decreased the biofilm formation with a consequent reduction in the acid production and metabolic activity of microbes. Such modifications showed promise as possible alternatives against Candida associated denture stomatitis. [ABSTRACT FROM AUTHOR]

Grafting is an effective approach to improve tomato yield and for tolerance to various abiotic and biotic stresses. This technique consists of using a vigorous or resistant plant (rootstock) to replace the root system of a genotype of economic interest (scion) but susceptible to one or more stress factors. The present work aimed to evaluate the physiological and productive response of a commercial tomato scion grafted on different rootstocks in Colombia's high-Andean region. For this purpose, a tomato cv. Libertador was grafted on two commercial ("Olimpo" and "Armada") tomato rootstocks in a randomized complete block experimental design. Four scionÃ--rootstock combinations were evaluated by vigor rootstock, resistant rootstock, self-grafting, and non-grafted plants. Net photosynthesis, transpiration rate, stomatal conductance, water use efficiency, and radiation use efficiency were evaluated during six phenological stages (701, 704, 706, 708, 710, and 712), according to the BBCH scale; while the leaf area index and quantum yield were analyzed in five phenological stages (except 706). The highest values of photosynthesis, stomatal conductance, water and radiation use efficiency were registered in the initial phase of the production stage (701), which tended to decline at the end of the life cycle (712). Transpiration rate was similar throughout the growth cycle. Nevertheless, vigor rootstock presented the lowest photosynthesis rate; it was superior in terms of leaf area index, leaves dry matter, and tomato yield. The quantum yield values of the photosystem II did not indicate photochemical injuries in any of the scionÃ--rootstock combinations. The higher tomato yield was reached in vigor rootstock and was associated with a more significant accumulation of dry matter in the leaf and higher leaf area index. [ABSTRACT FROM AUTHOR]

• Aluminum phosphide is used as a pesticide for grain storage. • It is used as suicidal or homicidal agent. • It causes occupational hazard to grain storehouse workers. • No antidote or screening biomarker is available. • Early diagnosis by biomarker development can provide early supportive management. Aluminum phosphide (AlP) is a popular fumigant used widely for the safe storage of food grain. Although A1P is free from toxic residues, it releases phosphine which acts on mitochondrial components of almost all types of pests. Unfortunately A1P is also a common suicidal agent in developing countries with no known antidote. In addition, accidental exposure to phosphine may also occur. AlP poisoning affects cardiac and vascular tissue directly and can result in multiorgan system failure leading to death in severe cases. There is no specific biomarker for diagnosing AlP poisoning and management depends on a high level of clinical suspicion. Although acetylcholinesterase has been suggested as a surrogate biomarker of AlP exposure, there are opposing views. In this review, we analyzed the relevant published material with emphasis on the need to recognize and explore the use of plasma mitochondrial enzyme activity as a potential biomarker for AlP exposure. [ABSTRACT FROM AUTHOR]

The khapra beetle, Trogoderma granarium (Everts), is considered one of the most destructive insect pests of wheat storages worldwide, whereas phosphine fumigation is common to manage this pest. The efficacy of phosphine use largely depends on its concentration, exposure time and target species. However, building an effective relationship between phosphine concentration and exposure time for T. granarium is of great importance. This research was conducted to evaluate the effects of concentration and time on phosphine toxicity against susceptible or resistant strains of T. granarium. Both strains of T. granarium were exposed to phosphine gas at various concentrations and exposure times in a laboratory. Our results showed that the exposure time was the more important variable than the phosphine concentration against both T. granarium strains; in contrast, the concentration was comparatively more important against the resistant strain than the susceptible one. This study highlights the importance of concentration and exposure time in phosphine fumigation efficacy against T. granarium. [ABSTRACT FROM AUTHOR]

A pot experiment was performed to investigate the effects of Trichoderma harzianum on the root morphology of Malus hupehensis Rehd. seedlings and their soil environment under replant conditions. The experiment consisted of four treatments: continuously cropped soil (CK1), methyl bromide fumigation (CK2), carrier substrate control (T1), and T. harzianum fertilizer (T2). Plant growth parameters, soil phenolic acid content, abundance of soil microorganisms, and root respiration rate were measured. Compared with CK1, plant height, basal diameter, and fresh weight were 34.58%, 27.55%, and 32.91% greater in T2; 11.35%, 12.10%, and 18.33% greater in T1; and 54.34%, 57.64%, and 45.74% greater in CK2. These metrics were significantly higher in the CK2 treatment than in the other treatments. The second highest values were recorded in the T2 treatment. Differences in root architecture were consistent with differences in biomass. Application of T. harzianum fertilizer was associated with increases of 45.45%, 120.06%, 86.44%, and 268.29% in the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), respectively, and there was little difference between T2 and CK2. The contents of phlorizin and phloretin were 39.39% and 51.70% less in T2, respectively, and 17.85% and 18.14% less in T1, respectively, compared with CK1. Trichoderma harzianum fertilizer increased the abundance of bacteria and actinomycetes while decreasing that of fungi. The gene copy numbers of Fusarium oxysporum and Fusarium moniliforme were 64.30% and 49.35% less, respectively, in the T2 treatment. The fungus population and the gene copy number of Fusarium oxysporum and Fusarium moniliforme was the least in CK2 because of the good sterilization effect. The T. harzianum fertilizer showed satisfactory effects in promoting the root growth of M. hupehensis, increasing the root resistance, decreasing the soil phenolic acid content, and significantly reducing the gene copy number of F. oxysporum and F. moniliforme. In summary, T. harzianum fertilizer is an effective and green alternative for the prevention and control of apple replant disease (ARD). [ABSTRACT FROM AUTHOR]

1-Methylcyclopropene, aminoethoxyvinylglycine, chlorine dioxide and nitric oxide were widely applied as ethylene synthesis inhibitors for crops at pre-harvest stages for various purposes. Durian (Durio zibethinus) was a seasonal fruit commonly cultivated in tropical regions. Durian was highly perishable at ambient condition due to its high respiration rate and ethylene accumulation. Preharvest treatment was considered as a promising strategy to regulate some physiological behaviors of durian during postharvest storage. This research was conducted during 2020 at Soc Trang Nanotech laboratory, Vietnam to evaluate the effectiveness of preharvest fumigation at dose 200 µL/L at 14 days before harvesting with 1-Methylcyclopropene (1-MCP), aminoethoxyvinylglycine (AVG), chlorine dioxide (ClO2) and nitric oxide (NO) on quality of durian fruit. After harvesting, the treated fruits were kept at 4oC for 28 days. In 7 day-interval, sample was taken to evaluate respiration rate, ascorbic acid content, glutathione content and ascorbic peroxidase activity. Results showed that 1-MCP-treated durian had the lowest respiration rate (101.24±1.27 mg CO2/kg/h) while maintained the highest ascorbic acid content (21.73±0.22 mg/100 g), glutathione content (29.30±0.11 µmol/kg) and ascorbic peroxidase activity (2.31±0.02 U/g) at the end of 28 days of storage. Preharvest treatment by 1-MCP significantly enhanced quality of durian fruit in an extended stability. [ABSTRACT FROM AUTHOR]

Sulfur fumigation is adopted in the post-harvest processing of herbal drugs. In addition to the sulfur dioxide residual, sulfur fumigation could also lead to chemical transformations of native compounds in the herbs to generate sulfur-containing derivatives. In this study, influence of sulfur fumigation on the chemical composition of Farfarae Flos (FF) was investigated by the ultra-high-performance liquid chromatography-Q exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry (UHPLC-Q-orbitrap HRMS). In addition to 103 native compounds in FF, 12 sulfur-containing caffeoylquinic acids were also detected after sulfur fumigation. The further screening results showed that the diagnostic sulfate/sulfite derivatives were effective for rapid discrimination of sulfur-fumigated FF samples. In brief, sulfur fumigation can induce chemical transformations of phenylpropanoids, and the corresponding sulfur-containing derivatives could be regarded as the characteristic chemical markers of sulfur-fumigated FF. [ABSTRACT FROM AUTHOR]

The saw-toothed grain beetle, Oryzaephilus surinamensis (Linnaeus) is a secondary pest of rice grains and other stored products. Lack of information on the population abundance, spatial, and temporal distribution of O. surinamensis rendered the management control strategy of this pest species less effective. The objective of this study was to investigate the abundance, spatial and temporal pattern of O. surinamensis populations from nine rice warehouses in three zones of Peninsular Malaysia (i.e., the northern, central and southern zones) for three continuous months. The results showed that the abundance of O. surinamensis populations varied significantly (p<0.05, p= 0.00) between zones, with the highest abundance for this species (69%) recorded from the Klang District, in the central zone, followed by Pasir Gudang (27%) in the southern zone, and Seberang Prai (4%) in the northern zone. The patterns of population abundance also showed significant differences between months, p<0.05 (p-value= 0.00-0.011) between all the warehouses. The factors that could be associated with the highest abundance of the pest were attributed to poor sanitation at the warehouses and inconsistency in the fumigation regime. For the spatial distribution analysis, SADIEShell_122 and Surfer8 software were applied. The distribution patterns of O. surinamensis populations varied significantly in all the warehouses, being significantly aggregated at p<0.05 (p=0.0385-0.0513) and Ia>1.0 (1.212-1.579), whilst being non-significantly and randomly distributed at p>0.05 (p=0.1154-0.91032) and Ia>1.0 (0.852-0.929). The significance of the aggregation might be due to the rapidly changing volume of the rice stock caused by the active and rapid turnover of the storage inventory. The results obtained were very valuable and informative in managing O. surinamensis infestation of stored rice by incorporating the spatial and temporal information of the pest populations in the management strategy for improving the rice and other stored products. [ABSTRACT FROM AUTHOR]

Highly convergent synthesis of angiotensin II receptor blockers has been accomplished by means of late-stage C–H arylation using functionalized aryl bromides. C–H arylation of 1-benzyl-5-phenyl-1 H -tetrazole with aryl bromides carrying methyl 2-ethoxybenzimidazole-7-carboxylate unexpectedly provided coupling products where ethyl group was migrated from oxygen to nitrogen atom. The O-to-N ethyl migration was completely suppressed by the use of N -pivaloyl- l -valine rather than the combined use of triphenylphosphine and sodium mesitylenesulfonate to result in the preferential formation of a key intermediate of candesartan cilexetil. In contrast, when an aryl bromide having ethyl 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate was employed, the C–H arylation proceeded smoothly to provide a late-stage intermediate, which rapidly led to olmesartan medoxomil in 3 steps. [ABSTRACT FROM AUTHOR]

The khapra beetle, Trogoderma granarium, is an important quarantine pest of stored-products. While it is not established in the North America, frequent interceptions highlight the need for treatments to eradicate isolated populations if they occur. Methyl bromide has long been the standard fumigant used for this purpose; however, increasing restrictions on its use necessitate the development of new treatment options. Here we evaluate a treatment for khapra beetle using a combination of sulfuryl fluoride (SF) and propylene oxide (PPO). Experiments were conducted to determine the most tolerant stages and the effective rates for each compound. Combination treatments using both products were then evaluated at several temperatures to determine effective doses for quarantine level control. The egg stage was by far the most tolerant to SF, requiring concentration × time (CT) products roughly 10-fold greater than the next most tolerant stage, diapausing larvae. Diapausing larvae were significantly more tolerant to SF than non-diapausing larvae in a recently collected 'field' strain, but not in a more than 30-yr-old 'laboratory' culture. PPO treatments were shown to completely control the egg stage at CTs greater than 155 hr-mgL-1 at both 10 and 20°C. Resulting combination treatments with initial dose rates of 96 and 40 mgL-1 at 10°C and 80 and 40 mgL-1 at 20°C are proposed for SF and PPO, respectively. These combination treatments utilize SF's efficacy against the larval stage along with PPO's superior ovicidal properties to provide enhanced treatment efficacy over each product alone against all life stages of khapra beetle. [ABSTRACT FROM AUTHOR]

A systematic computational study addressing the entire chemical space of guaianes in conjunction with an analysis of all known compounds shows that 1,3‐hydride shifts are rare events in guaiane biosynthesis. As demonstrated here, 1,3‐hydride shifts towards guaianes can only be realized for two stereochemically well defined out of numerous possible stereoisomeric skeletons. One example is given by the mechanism of guaia‐4(15)‐en‐11‐ol synthase from California poplar, an enzyme that yields guaianes with unusual stereochemical properties. The general results from DFT calculations were experimentally verified through isotopic‐labeling experiments with guaia‐4(15)‐en‐11‐ol synthase. [ABSTRACT FROM AUTHOR]

Summary: Plant-parasitic nematodes (PPN) cause significant yield reduction in commercial pineapple (Ananas comosus) worldwide. In Kenya, few nematode studies have been conducted, although the main commercial pineapple producer has sole dispensation to use Telone II (1,3-Dichloropropene) indicating the magnitude of the nematode problem. This study was conducted with the aim to investigate the population densities and diversity of nematodes in two commercial plantations with two contrasting management practices. We additionally assessed the influence of crop age and compared this with nearby smallholder pineapple production systems. Soil and root samples were collected from fields of different ages in each commercial plantation and from 29 smallholder fields. A total of 18 genera were associated with pineapple, with a relatively greater diversity found in smallholder than commercial farms. The most prevalent genus was Meloidogyne spp. (M. javanica) followed by Helicotylenchus spp., Tylenchus spp. and Aphelenchoides spp. PPN densities were higher in relatively older fields of 24 and 36 months than from fallow and 3-month-old fields. Regression analysis additionally demonstrated the rise of PPN densities with age of pineapple fields, especially Meloidogyne spp., while free-living nematode densities declined. This study provides an indication of the high level of PPN infection in pineapple in Kenya, which would constitute an important factor contributing to low yields. The study confirms an obvious need for pineapple producers to control PPN to improve crop yields. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Cyclodextrin was successfully covalently grafted to the surface of titanium dioxide. • Introduction of cyclodextrin improved the photocatalytic performance of titanium dioxide. • This modification increased the degradation efficiency of methyl bromide by 2.7 times. A photocatalytic system based on the cooperative effect of β-cyclodextrin (β-CD) was established. Here, β-CDs were covalently grafted onto the surface of TiO 2 nanoparticles through hexamethylene diisocyanate bonds. The structure and photocatalytic properties of the resulting photocatalysts were characterized by various analytical methods. This modification resulted in a 2.7-fold improvement in the degradation efficiency of the pure TiO 2 for methylene blue (MB) and showed good stability in cyclic degradation experiments. [ABSTRACT FROM AUTHOR]

Next-Generation Risk Assessment (NGRA) aims to implement New Approach Methodologies (NAMs) into risk assessment and to rely on new in vivo testing in animals only as a last resort. However, various technical and regulatory hurdles impede their regulatory implementation. Assumptions about the public's expectations could act as barriers to the acceptance of NAMs. This study aimed at investigating public views of animal testing and potential alternatives, namely in vitro and in silico testing. An online survey was conducted (N = 965). The results suggest that people make trade-offs, as they experience negative affect regarding in vivo testing, which partly might explain their openness regarding certain alternatives. In vitro tests were attributed the highest ability to determine harmful effects of chemicals for different endpoints, followed by in vivo and in silico tests. Our results further showed that many people accept chemicals to be only tested with alternatives, with highest acceptance for household consumer products, food contact material or building materials and less accepting for medicines and foods. This article addresses potential challenges that might arise from public perceptions and thus, contributes to the bottom-up initiatives to overcome the hurdles to the implementation of NAMs in regulatory risk assessment. • Acceptability of in vivo testing was low, but highest for medicine and food. • In vitro tests elicited the highest expected ability to determine harmful effects. • Testing substances with alternatives to in vivo tests did not elicit public concern. • People apply affect and trust heuristics when confronted with different tests. [ABSTRACT FROM AUTHOR]