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AbstractThe widespread use of the herbicide alachlor disrupted the endocrine system of organisms in the soil and severely contaminated the soil. Biodegradable herbicides have become a hot research topic. In this study, the efficient degrading strain Trichoderma harzianum H12 was isolated from the soil which is applied with amide herbicides for a long time. The effects of temperature, pH, strain dosage and oncentration of alachlor on the degradation of alachlor by dominant bacteria were studied. The changing trend of malondialdehyde (MDA) content and related typical enzyme activities in earthworms were analyzed to characterize the changes in toxicity of alachlor and its metabolites. Finally, the dominant bacteria were added into the rhizosphere soil of corn to establish a corn-microorganism combined remediation system. The research results showed that: after 5d, the degradation rate of strain H12 to 50 mg/L alachlor under the optimal conditions was 96.1%. The activities of superoxide dismutase (SOD) and catalase (CAT) in earthworms were increased, and the content of MDA was always significantly higher than that in the control group, resulting in lipid peroxidation in earthworms. However, the activity of acetylcholinesterase (AchE) finally recovered to the level of the control group, and the toxicity of metabolites was less than that of alachlor. The degradation rate of the corn and strain H12 combined in the remediation of alachlor-contaminated soil was as high as 85.9%, and the addition of strain H12 alleviated the toxic effects of alachlor on corn. [ABSTRACT FROM AUTHOR]

The clay-alginate composites showed relatively excellent drug sustained-release properties. In order to enhance the sustained-release property of bentonite-alginate composite gels, the alachlor loaded chitosan quaternary modified bentonite-alginate composite gel was prepared. The underlying effect and mechanism of the structure of modified bentonite-alginate composite gels on the release behavior of alachlor were explored by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The results showed that the release of alachlor from the composite gel was dominated by Fickian diffusion and closely related to the adsorption capacity and permeability of the matrix. The chitosan quaternary combined with the negative charge sites on the surface of bentonite nanoplatelets, which significantly enhanced the adsorption capacity of bentonite for alachlor, and the adsorption equilibrium constant (Ka ) of alachlor on bentonite and modified bentonite were 0.13 and 0.40, respectively. Also, the stacking aggregation of bentonite nanoplatelets and the permeability of the gel network were effectively reduced through the electrostatic interaction between chitosan quaternary and alginate, and the permeability of modified bentonite-alginate composite gel is 9.6 times that of pure alginate gel. The release kinetics of alachlor from the composites revealed that the release rate of alachlor from the composite gel first decreased and then increased as the content of clay gradually increased. The best-sustained release property of composite gel was obtained when the mass fractions of alginate, chitosan quaternary modified bentonite, alachlor, and deionized water were 1.6%, 0.2%, 0.2%, and 97.8%, respectively, under which the release time of alachlor from bentonite-alginate and modified bentonite-alginate composite gels was 4.4 and 8.3 times longer than the release from pure alginate gel, respectively. [ABSTRACT FROM AUTHOR]

Pesticide compounds can influence denitrification processes in groundwater in many ways. This study observed behavior of three selected pesticides under denitrifying conditions. Alachlor, terbuthylazine, and tebuconazole, in a concentration of 0.1 mL L−1, were examined using two laboratory denitrifications assays: a "short" 7-day and a "long" 28-day test. During these tests, removal of pesticides via adsorption and biotic decomposition, as well as the efficiency of nitrate removal in the presence of the pesticides, were measured. No considerable inhibition of the denitrification process was observed for any of the pesticides. On the contrary, significant stimulation was observed after 21 days for alachlor (49%) and after seven days for terbuthylazine (40%) and tebuconazole (36%). Adsorption was in progress only during the first seven days in the case of all tested pesticides and increased only negligibly afterwards. Immediate adsorption of terbuthylazine was probably influenced by the mercuric chloride inhibitor. A biotic loss of 4% was measured only in the case of alachlor. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on the effectiveness of ultrafiltration (UF) and nanofiltration (NF) membrane processes and selected photolytic processes in the context of reducing the concentration of organic micropollutants. Studies on the removal of organic matter (dissolved organic carbon) were carried out on a laboratory scale in order to select optimal parameters for the processes. Analysis of micropollutant reduction was carried out on a semi-technical scale. The micropollutants analyzed were: 4-octylphenol, 4-nonylphenol, anthracene, alachlor, di(2-ethylhexyl)phthalate, heptachlor and heptachlor epoxide. In the initial phase of the study, the most effective ultra- and nanofiltration membranes in terms of natural organic matter removal were selected. Among the tested advanced oxidation processes viz: UV, UV/O3, UV/TiO2 and UV/H2O2, the process using simultaneous UV and ozone was selected as the most effective. In semi-technical scale tests, the following values of micropollutant removal were achieved: UF 63%-100%, NF 100%, UV/O3 32%-100%. [ABSTRACT FROM AUTHOR]

Pesticide compounds can influence denitrification processes in groundwater in many ways. This study observed behavior of three selected pesticides under denitrifying conditions. Alachlor, terbuthylazine, and tebuconazole, in a concentration of 0.1 mL L−1, were examined using two laboratory denitrifications assays: a “short” 7-day and a “long” 28-day test. During these tests, removal of pesticides via adsorption and biotic decomposition, as well as the efficiency of nitrate removal in the presence of the pesticides, were measured. No considerable inhibition of the denitrification process was observed for any of the pesticides. On the contrary, significant stimulation was observed after 21 days for alachlor (49%) and after seven days for terbuthylazine (40%) and tebuconazole (36%). Adsorption was in progress only during the first seven days in the case of all tested pesticides and increased only negligibly afterwards. Immediate adsorption of terbuthylazine was probably influenced by the mercuric chloride inhibitor. A biotic loss of 4% was measured only in the case of alachlor.

Many catchments in Nepal are affected by intensive agricultural activities, leading to extensive pesticide usages. This study aimed to assess pesticide abundance in concurrently collected water, sediment and fish samples for the first time in intensively cultivated catchment (Indra Sarowar) located in the mid-hill region of Nepal during the rice and vegetables growing season. A total of 75 pesticides were analysed, of which 4 pesticides (alachlor, diuron, metalaxyl and pyrimethanil) were present in water with detection frequency (DF) > 40%, with alachlor (0.62 – 2.68 µg L−1) being ubiquitous. In the sediment of tributaries, the pesticides p,p′-DDT, β-HCH, alachlor and diuron were detected with DF exceeding 40%, where β-HCH was commonly observed (DF = 92%) with concentration ranging from 6.29 – 99.22 µg kg−1. The ecotoxicological risk indicated that herbicides (alachlor and diuron) posed a high risk to aquatic organisms in both tributaries and reservoir water. Such risk in sediment was even more pronounced, with alachlor and diuron showing up to 2.3 and 53.7 times higher risk respectively compared to water samples. However, none of these herbicides were detected in fish muscles. Among the fish species studied, pyrimethanil was the only quantified pesticide in edible tissue of both cage cultured (0.35 – 1.80 µg g−1 ww) and open stock fishes (0.06 – 1.12 µg g−1 ww). The consumer risk assessment showed very low human health risk associated with fish consumption (HQ < 0.2). Nonetheless, long-term consumption of contaminated fish may pose some risk that cannot be ignored. Overall, this study generated the benchmark data highlighting pervasive presence of banned (DDT, endosulfan, HCH) and unapproved (alachlor, diuron, pyrimethanil) pesticides in the environmental compartments in the mid-hill's streams of Nepal. [ABSTRACT FROM AUTHOR]

When jobs offered by different employers are not perfect substitutes, employers gain wage-setting power; the extent of this power can be captured by the elasticity of labor supply to the firm. The authors collect 1,320 estimates of this parameter from 53 studies. Findings show a prominent discrepancy between estimates of direct elasticity of labor supply to changes in wage (smaller) and the estimates converted from inverse elasticities (larger), suggesting that labor market institutions may rein in a substantial amount of firm wage-setting power. This gap remains after they control for 22 additional variables and use Bayesian Model Averaging and LASSO to address model uncertainty; however, it is less pronounced for studies employing an identification strategy. Furthermore, the authors find strong evidence that implies the literature on direct estimates is prone to selective reporting: Negative estimates of the elasticity of labor supply to the firm tend to be discarded, leading to upward bias in the mean reported estimate. Additionally, they point out several socioeconomic factors that seem to affect the degree of monopsony power. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the transport behavior of two organic and persistent contaminants (alachlor and pentachlorobenzene) on Danube alluvial sediment in the absence and in the presence of microbially inoculated biochar produced at 400 °C and three hydrochars produced at 180, 200, and 220 °C. Stainless steel columns were used for the sorption experiments in nonequilibrium conditions. Obtained results were modeled using the advective‐dispersive equation under nonequilibrium conditions. Transport of these compounds through the alluvial sediment column showed that the retention time increased with increasing molecular hydrophobicity. Inoculated biochar increases the retardation of both compounds: twofold for pentachlorobenzene compared with alachlor as a consequence of a higher hydrophobicity. Obtained results indicate that the highest biodegradation coefficient was observed for pentachlorobenzene (λ = 10) in alluvial sediment with addition of an inoculated hydrochar, which is assumed to be a consequence of biosorption. Moreover, all experiments on the columns indicate that the addition of inoculated chars yields a significantly higher Rd coefficient for pentachlorobenzene than for alachlor. Bacterial counts increased in all of the column experiments, which indicates the successful adaptation of microorganisms to experimental conditions and their potential for the removal of a large number of organic pollutants. Thus, addition of inoculated chars to contaminated sediments has the potential as a remediation technique to inhibit the leaching of pollutants to groundwaters. Integr Environ Assess Manag 2023;19:933–942. © 2022 SETAC Key Points: The transport behavior of alachlor and pentachlorobenzene on Danube alluvial sediment was investigated in the presence of microbially inoculated chars.The addition of microbially inoculated chars increased retention of both compounds.Bacillus megaterium BD5 immobilized on carbon‐based materials showed great efficiency in the removal of organic pollutants from the sediment and water system.The addition of inoculated chars to contaminated sediments has potential as a remediation technique to inhibit the leaching of pollutants into groundwater. [ABSTRACT FROM AUTHOR]

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In this work, a rapid, highly selective, reusable and effective method was developed for simultaneous determination of alachlor, acetochlor and pretilachlor in field soil by GC–MS coupled with MIL-101 based SPE. Main factors affecting the SPE by using MIL-101 were optimized. Moreover, by comparing with the other commercial materials such as C18, PSA and Florisil, the MIL-101(Cr) exhibited excellent adsorption performance, which aimed at amide herbicides. On the other hand, method validation displayed excellent method performance, achieving good linearities with r2 ≥ 0.9921, limits of detection between 0.25–0.45 μg kg−1, enrichment factors ≥ 89, matrix effect in the range of ± 20%, recoveries between 86.3% and 102.4%, and RSD lower than 4.38%. The developed method was successfully applied to the determination of amide herbicides in soil taken from the wheat, corn and soybean field at different depths, where the concentration of alachlor, acetochlor and pretilachlor were in the range of 0.62–8.04 μg kg−1. It was demonstrated that the more depth of soil, the lower of three amide herbicides. This finding could be proposed a novel method to detect the amide herbicides in the agriculture and food industry. [ABSTRACT FROM AUTHOR]

Reductive hydrodechlorination is an effective approach to enhance the degradation rate of chlorinated herbicides such as alachlor, which are frequently detected in ground and surface water. In this study, a cobalt porphyrin complex with eight triazole units and alkyl chains, CoPor8T, was synthesized to catalyze the reductive hydrodechlorination of alachlor. Mechanistic study was performed using a combination of voltametric, spectroscopic, and electrospectroscopic techniques. A conversion yield of 84 % at −1.8 V vs. Fc/Fc+ and chloride ion concentration of 96 % was obtained after electrocatalysis. This work provides a new avenue of using molecular catalysts for electrocatalytic chlorinated herbicide remediation. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate if the maximum values (MVs) for pesticides in surface freshwater included in CONAMA directive 357/2005 are safe for aquatic biota, comparing them with ecotoxicology data published in the literature. The terms "aquatic toxicity", "chronic" "acute", "LC50", "EC50", "NOEL", "NOEC" and the name of each pesticide were used for searches on the research platforms. Data from 534 tests reported in 37 published articles and three ecotoxicological databases were included in this study; 24% of the tests were carried out with producer organisms, 34% with primary consumers and 42% with secondary consumers. Microcrustaceans of the Daphnia genus and the fishes Pimephales promelas and Oncorhynchus mykiss were the organisms most used. Atrazine, alachlor and metolachlor were the most investigated pesticides. Atrazine and alachlor are approved in Brazil, with atrazine ranking fourth among the most used pesticides in the country. The results indicated that of the 27 pesticides included in the standard directive, 17 have a risk quotient (RQ) higher than the level of concern for at least one ecotoxicological parameter and may not protect the aquatic biota. The insecticide malathion, used in various agricultural crops in Brazil, was the one that presented the highest RQs (3125 and 3,125,000 for freshwaters classified as 1/2 and 3, respectively), related to a LC50 (96 h) of 0.000032 µg/L in Chironomus ramosus. The results indicate that CONAMA directive 357/2005 should be updated in line with the current use of pesticides in the country, and the MVs should be re-evaluated so that they do not represent toxicity for the aquatic biota. [ABSTRACT FROM AUTHOR]

Occasionally, our group found that the degradation of tetracycline by ferrate(VI) could be promoted by four co-exist contaminants, containing aromatic amines (ofloxacin, diatrizoic acid, sulfadiazine and alachlor). This study investigated the promotion of aromatic amine groups on tetracycline degradation by ferrate(VI) by using aniline as a model compound. The results implied that the presence of aniline increased the degradation rate of tetracycline by 2.76 times, and the enhancement was weakened gradually with the decrease of pH from 10 to 7.5. The generation of Fe(IV) and·OH by the reaction between ferrate(VI) and aniline was proposed to enhance the degradation of tetracycline, supported by quenching experiments, electron paramagnetic resonance (EPR) and theoretical calculations. A positive correlation was found between the rate constant of tetracycline degradation and the electron-donating ability of the substituted amines (quantified by the Hammett substituent constants). In addition, the degradation of tetracycline was remarkably inhibited by HA and some inorganic ions such as NO 3 -, SO 4 2-, Cl-, Ca2+, and Mg2+, and the inhibition also happened in the Songhua River water and the secondary effluent. The present study provided an insight into the complex oxidation process for the degradation of micropollutants containing aromatic amine by ferrate in water treatment. [Display omitted] • Aniline promoted tetracycline degradation by Fe(VI). • k obs is positively correlated with electron-donating ability of substituted anilines. • Fe(IV) and·OH were the main active species to promote tetracycline degradation. • Inorganic ions and HA could inhibit the promotion of tetracycline degradation. • The promotion becomes increasingly significant with the increase of pH. [ABSTRACT FROM AUTHOR]

Alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl]acetamide] is a chloroacetanilide herbicide and has been widely used as a selective pre-emergent and post-emergent herbicide to control weeds and grass. Due to its wide usage, direct application on the ground, high solubility in water, and moderate persistence, alachlor and its metabolites have been detected in various environments. Therefore, there is an increasing concern about the environmental fate of alachlor and its metabolites. Microbial biodegradation is a main method of removal of alachlor in the natural environment. In this study, we isolated new alachlor degrading bacterium and proposed a novel alachlor-degrading pathway. The alachlor-degrading bacterial strain, GC-A6, was identified as Acinetobacter sp. using 16S rRNA gene sequence analysis. Acinetobacter sp. GC-A6 utilized alachlor as its sole carbon source and degraded 100 mg L−1 of alachlor within 48 h, which was the highest alachlor degradation efficiency. The degradation pathway of alachlor was studied using GC-MS analysis. Alachlor was initially degraded to 2-chloro-N-(2,6-diethylphenyl) acetamide, which was further degraded to 2,6-diethylaniline and 7-ethylindoline, respectively. 2,6-Diethylaniline was transformed into N-(2,6-diethylphenyl) formamide. N-(2,6-diethylphenyl) formamide was a first-reported intermediate during the degrading pathway of alachlor by single isolate. [ABSTRACT FROM AUTHOR]

In our work, a cationic lignin (CL) modified bentonite‐alginate nanocomposite gel was prepared and used to enhance the sustained release of alachlor. The underlying gel structure‐release property relationships were explored. The results showed that the release of alachlor from nanocomposite gel was dominated by Fickian diffusion and closely related to the adsorption capacity and permeability of the matrix. The adsorption capacity of bentonite for alachlor was remarkably improved due to the modification of CL; Furthermore, the permeability of the matrix was further reduced via the electrostatic interaction between CL and the alginate. The release kinetics demonstrated that the sustained release property of modified bentonite‐alginate nanocomposite gels was significantly enhanced. The release time of 50% alachlor from bentonite‐alginate and modified bentonite‐alginate nanocomposite gels was 4.4 and 14.1 times longer than that of the release from pure alginate gel, respectively. [ABSTRACT FROM AUTHOR]

Alachlor is a chloroacetanilide herbicide which is commonly used to control different broad leaf weeds and annual grasses at their pre-emergence stage from various agricultural crops including maize, sorghum and soybean. Owing to its intensive and repeated use in agricultural fields, this herbicide was detected beyond the permissible limits in different soil and water resources worldwide. Ecotoxicological data suggest for its harmful impacts on different biotic components of the environment including plants, animal and human beings. The present review article has been focused on an overview of the toxic effects of alachlor as well as different processes including sorption, transport, leaching and transformations governing its fates in the environment. A detailed review of the data indicated that alachlor has a relatively low sorption and persistence in the soil and aqueous media because it is easily degraded by different physicochemical processes as well as by different microbial strains existing in the soil. The degradation results into the formation of different types of metabolites following different metabolic pathways, which have also been presented in this review article. The distinctive role of different bacterial and fungal strains in the biotransformation of this herbicide in soil and aqueous media as well as the enzymes potentially involved in its biodegradation has also been highlighted herein. [ABSTRACT FROM AUTHOR]

To promote the controlled release efficacy of nanocomposites based on alginate and bentonite, (3-chloro-2-hydroxypropyl)trimethyl ammonium grafted starch was prepared and used as modifying agent of the clay. The nanocomposites were characterized by FTIR, XRD, SEM and TG analysis, to reveal the structural effects on the swelling property of the matrix and the release of alachlor, the model compound. Thermodynamics study indicated that the adsorption of alachlor on the bentonite was dominated by hydrophobic interaction with the siloxane surface of the clay and enhanced by the binding of the cationic starch. The electrostatic attraction between alginate and cationic starch bound on the surface also decreased the aggregation of bentonite platelets, leading to a more compact structure of the nanocomposites. The higher adsorption capability and lower permeability of the matrix resulted in a slower release of alachlor, which was dominated by Fickian diffusion mechanism. The release of alachlor first decreased and then increased with increasing content of bentonite and cationic starch modified bentonite in the nanocomposites, reaching a minimum around weight percentage 10%, at which the time taken for 50% of active ingredient to be released were 4.4 and 7.3 times that for the release from pure alginate hydrogel. [Display omitted] • Cationic starch binding increased surface hydrophobicity of bentonite. • Interaction of bentonite with alachlor enhanced by organic modification. • Bentonite nanoplatelets well dispersed in the composites with alginate. • Sustained release property of nanocomposites significantly improved. [ABSTRACT FROM AUTHOR]

The paper presents the experimental results obtained in the year 2020 regarding the individual effect of five weed killers, used for the control of weeds at the sunflowers crops, as well as that action in association with two other herbicides: Sencor applied in a quantity of o,4 kg/ha and Gesagrade 50 applied in a quantity of 3 kg/ha. As concerns the effect of the individual application of each weed killer, on the first place we can put Alachlor with an average production increase of 6,95 q/ha or by Treflan with an average production increase of 6,80 q/ha, or 33,0% as compared to the witness. The weed control by use of herbicides, is a very effective method, this way eliminating the hand hard work used for maintaining the growing. [ABSTRACT FROM AUTHOR]

Alachlor, a widely used chloroacetanilide herbicide for controlling annual grasses in crops, has been reported to rapidly trigger protein denaturation and aggregation in the eukaryotic model organism Saccharomyces cerevisiae. Therefore, this study aimed to uncover cellular mechanisms involved in preventing alachlor-induced proteotoxicity. The findings reveal that the ubiquitin-proteasome system (UPS) plays a crucial role in eliminating alachlor-denatured proteins by tagging them with polyubiquitin for subsequent proteasomal degradation. Exposure to alachlor rapidly induced an inhibition of proteasome activity by 90 % within 30 min. The molecular docking analysis suggests that this inhibition likely results from the binding of alachlor to β subunits within the catalytic core of the proteasome. Notably, our data suggest that nascent proteins in the endoplasmic reticulum (ER) are the primary targets of alachlor. Consequently, the unfolded protein response (UPR), responsible for coping with aberrant proteins in the ER, becomes activated within 1 h of alachlor treatment, leading to the splicing of HAC1 mRNA into the active transcription activator Hac1p and the upregulation of UPR gene expression. These findings underscore the critical roles of the protein quality control systems UPS and UPR in mitigating alachlor-induced proteotoxicity by degrading alachlor-denatured proteins and enhancing the protein folding capacity of the ER. [Display omitted] • ER nascent proteins are the major target of alachlor. • Sublethal toxicity of alachlor rapidly triggers ER stress. • The UPR pathway is triggered to cope with alachlor-denatured proteins in the ER. • The UPS is involved in degrading alachlor-denatured proteins. [ABSTRACT FROM AUTHOR]

Regulating the distribution of reactive oxygen species generated from H2O2 activation is the prerequisite to ensuring the efficient and safe use of H2O2 in the chemistry and life science fields. Herein, we demonstrate that constructing a dual Cu−Fe site through the self‐assembly of single‐atomic‐layered Cu5 nanoclusters onto a FeS2 surface achieves selective H2O2 activation with high efficiency. Unlike its unitary Cu or Fe counterpart, the dual Cu−Fe sites residing at the perimeter zone of the Cu5/FeS2 interface facilitate H2O2 adsorption and barrierless decomposition into ⋅OH via forming a bridging Cu‐O‐O‐Fe complex. The robust in situ formation of ⋅OH governed by this atomic‐layered catalyst enables the effective oxidation of several refractory toxic pollutants across a broad pH range, including alachlor, sulfadimidine, p‐nitrobenzoic acid, p‐chlorophenol, p‐chloronitrobenzene. This work highlights the concept of building a dual catalytic site in manipulating selective H2O2 activation on the surface molecular level towards efficient environmental control and beyond. [ABSTRACT FROM AUTHOR]

The use of herbicides for weed control in arable crop production is known to be fast and effective. However, there is paucity of information on the safety of commonly used grass herbicides on emergence, growth, and productivity of sesame (Sesamum indicum L.) genotypes currently being grown in Zimbabwe. A study was carried out in Zimbabwe during the 2017/18 cropping season in Gokwe South to evaluate the effect of alachlor, metolachlor, propaquizafop, and fluazifop-p-butyl on seed germination, growth, and yield of three sesame genotypes, namely, IETC, Lind 02, and Ziada 94. A laboratory experiment was laid in a completely randomised design with genotype and herbicide type as the factors. Seed germination, radicle, and plumule length were recorded at the end of the experiment. In the pot studies, two separate experiments were carried out to evaluate the effect of pre and postemergence herbicides on 50% emergence, plant height, number of branches, 50% flowering, number of pods, and yield of three sesame genotypes. The laboratory experiment results revealed significant (p < 0.05) interactions among varieties and preemergence graminicides for germination percentage, radicle length, plumule length, and germination vigor index. Alachlor and metolachlor differentially reduced all germination parameters in the sesame genotypes used in the study. In the preemergence pot studies, there were significant (p < 0.05) interactions on 50% emergence, plant height, and number of branches but not on number of pods and yield. Metolachlor significantly reduced all the measured parameters in IETC and Ziada 94. In the postemergence pot study, propaquizafop significantly (p < 0.05) reduced plant height, number of pods, and yield of sesame more than fluazifop-p-butyl and hand pulling. It can be concluded that metolachlor and propaquizafop are not safe for use in these sesame genotypes at dosage rates that were used in this study. There is need for further screening of more sesame genotypes for tolerance to these and other commonly used genotypes to avoid unintentional phytotoxic damage on sesame. [ABSTRACT FROM AUTHOR]

Omega-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA, C20:5 ω -3) are essential for human health and fish growth especially in aquaculture sector. However, with the growing of aquaculture, the demand of PUFA supply also has been increasing. Fistulifera solaris , a marine diatom, is known for its ability to accumulate 65% of lipid content per dry cell weight, and can produce the high content of EPA. Thus, this diatom shows a great potential to be a feedstock of omega-3 PUFAs for fish feeds. In this study, in order to further understand and enhance the metabolism of PUFA biosynthesis in the diatom, the impacts of ketoacyl-ACP synthase (KAS) and ketoacyl-CoA synthase (KCS) inhibition on the PUFA production were analyzed by adding the specific inhibitors. KAS and KCS enzymes both play a role in the fatty acid elongation. As a result, the inhibition of KAS showed an increase in EPA content without arresting the cell growth. On the other hand, inhibition of KCS did not show a significant impact on the PUFA content in F. solaris. Our finding suggests that the specific suppression of KAS function can be a promising way to enhance the omega-3 PUFA production in F. solaris. [ABSTRACT FROM AUTHOR]

The efficiency in water treatment by granulated complexes formed from the clay bentonite with (i) micelles of the cations of octadecyltrimethyl-ammonium (ODTMA) or (ii) liposomes of didodecyldimethyl-ammonium (DDAB) was investigated. The bentonite–ODTMA complexes were synthesized in three variations: I. mass ratio of 68/32, which resulted in an excess of positive charge of half of the clay cation exchange capacity and is denoted "ordinary"; II. complexes having higher loads of ODTMA, denoted "enriched"; and III. "neutral". These variations were designed to optimize the efficiency and reduce the costs of water treatment. "Ordinary" and "neutral" complexes of DDAB were also synthesized. The "ordinary" complex of ODTMA was shown to be efficient in the removal of anionic/hydrophobic molecules and bacteria. The "enriched" complexes were more active in removal of bacteria from water by filtration due to the higher release of free ODTMA cations, which causes biostatic/biocidal effects. The corresponding "ordinary" and "neutral" complexes of ODTMA and DDAB yielded the same efficiency in removal from water of the neutral and hydrophobic herbicides, S-metolachlor (i) and alachlor (ii), respectively. Model calculations, which considered sorption/desorption and convection yielded simulations and predictions of filtration results of the herbicides. The neutral complexes are advantageous since their production saves about 1/3 of the amount of ODTMA or DDAB, which constitutes the expensive component in the respective composite. [ABSTRACT FROM AUTHOR]

The increasing use of agrochemicals, alone and in combination, has been implicated as a potential causative factor in the decline of amphibians worldwide. Fertilizers and pesticides are frequently combined into single‐use tank mixtures for agricultural applications to decrease costs while meeting the food demands of a growing human population. Limited data are available on the effects of increased nitrogen levels in nontarget species, such as amphibians, and therefore investigating alterations in the nitrogen cycle and its impacts on amphibians needs to be considered in best management practices going forward. The objective of the present study was to elucidate the impact of fertilizer (urea) and herbicide (atrazine and/or alachlor) tank mixtures on the hepatic metabolome of juvenile leopard frogs as well as to investigate alterations in oxidative stress by relating these changes to glutathione (GSH) levels. Herbicide exposure only moderately increased this parameter in amphibians, however, urea alone and in combination with either atrazine or alachlor statistically elevated GSH levels. Interestingly, urea also inhibited pesticide uptake: calculated bioconcentration factors were greatly decreased for atrazine and alachlor when urea was present in the exposure mixture. Metabolomic profiling identified fluxes in hepatic metabolites that are involved in GSH and carbohydrate metabolic processes as well as altered intermediates in the urea cycle. Ultimately, understanding the biological impacts of nitrogenous fertilizers alone and in combination with pesticide exposure will inform best management practices to conserve declining amphibian populations worldwide. Environ Toxicol Chem 2022;41:122–133. © 2021 SETAC [ABSTRACT FROM AUTHOR]

Environmental fate of herbicide, Alachlor was evaluated by closely imitating the natural pedosphere through multifarious experiments such as; adsorption, desorption, hydrolysis, photo-degradation and biodegradation. Ten heterogeneous and agriculturally significant soils were utilised for these experiments. Sorption experiments, performed through batch equilibrium method indicated Alachlor distribution ranging from 12 µg ml−1 to 75 µg ml−1. Soil physicochemical characteristics highly influenced the sorption process, indicating an overall weaker physisorption and an exothermic reaction reflected via negative values for Gibbs free energy. Degradation assays were performed for the determination of the impact of biotic and abiotic constraints on Alachlor dissipation. UV-visible spectrophotometry and GC-MS were utilised to analyse Alachlor treated soil samples following extraction at fixed intervals. First-order reaction kinetics were applied on Alachlor degradation. Lowest half-life in hydrolysis, photo-degradation and biodegradation was 2.2, 1.5 and 0.5 days, respectively, while the highest was 5.7, 2.5 and 1.7 days, respectively. Highest transformation percentages attained by hydrolysis, photo-degradation and biodegradation were 96.7%, 99.7% and 99.9%, respectively. Results depicted mediocre binding and less persistence of Alachlor to the soils whilst being exceedingly vulnerable to transformation paths. [ABSTRACT FROM AUTHOR]

An analytical method, solid-phase extraction combined with dispersive liquid–liquid microextraction (SPE–DLLME), was established to extract and determine the herbicides in aqueous samples. In this method, herbicides were adsorbed from a large volume of aqueous samples (100 mL) into 500 mg functionalized octadecyl silica (C18) sorbent. After the elution of the desired compounds from the sorbent by using acetone, DLLME technique was performed on the obtained solution. Under the optimum conditions, the calibration graphs are linear in the range of 0.02–10 µg L−1 and limits of detection (LODs) are in the range of 0.003–0.006 µg L−1. The relative standard deviations (RSDs, for 0.50 µg L−1 of 2,4-D and alachlor, and 1.00 µg L−1 of atrazine in water) are in the range of 6.1–8.1% (n = 5). The SPE–DLLME provided a high enrichment factor (1725–2065) for herbicides. [ABSTRACT FROM AUTHOR]

This article explores the benefits of electrochemical oxidation in pulsed mode, using potential, current, and power pulses. While potential and current pulse electrochemical technology has been previously studied for wastewater treatment, no study has included power pulses until now. The objective of this work is to highlight the advantages of power pulses by applying this pulse type to the electrochemical oxidation of a probe molecule, alachlor. For this aim, the influence of operating parameters and the comparison of the different pulse modes were investigated and compared to the results obtained with the electrochemical oxidation of alachlor in continuous mode. The study shows that the best results were obtained with the power pulse electrochemical oxidation with 100% alachlor degradation after 180 min and a mineralisation yield of 38.3% after 240 min. These results were better than those reported in the literature for treatments with continuous current input using platinum electrodes. This new technique could be an effective and efficient way to treat contaminated water and reduce the pressure on freshwater reserves.

The purpose of this study was to explore the stability and toxicity of the herbicides and their degradation byproduct after exposure to different environmental factors. Triazines (atrazine, propazine, simazine) and chloroacetanilides (acetochlor, alachlor, metolachlor) which are commonly used herbicides were evaluated for cytotoxicity in different UV (254 nm and 365 nm) and temperature (4 °C, 23 °C, and 40 °C) conditions as well as degradation rates. Atrazine with the highest LD50 (4.23 μg mL−1) was less toxic than the other tested triazine herbicides Chloroacetanilides tested were more toxic than tested triazines, with LD50 0.08–1.42 μg mL−1 vs 1.44–4.23 μg mL−1, respectively. Alachlor with LD50 0.08 μg mL−1 showed the strongest toxic response as compared with other tested herbicides. Temperatures only did not alter cytotoxicity of the tested herbicides, except for acetochlor and alachlor showing about 45 % more cell death after exposure to 40 °C for 2 h. At all 3 tested temperatures, 2 h of UV treatments did not affect cytotoxic effects of the tested herbicides, except for acetochlor and alachlor. At 4 °C, acetochlor toxicity was attenuated about 63 % after UV 365 nm exposure; but alachlor toxicity was enhanced after either UV 254 or 365 nm exposure for about 40 % and 24 %, respectively. At 23 °C, acetochlor toxicity was enhanced about 35 % after UV 254 nm exposure, but attenuated about 48 % after UV 365 nm exposure. Alachlor toxicity was enhanced about 34 % after UV 254 nm and 23 °C exposure. In combination of UV 254 nm and 40 °C, acetochlor toxicity was lowered by 63 % and alachlor toxicity was no change as compared with 4 °C, no UV group. After co-treatment with UV 365 nm and 40 °C both acetochlor and alachlor toxicity was enhanced 55 % and 80 %, respectively. Through degradation analysis by LC-MS/MS, alachlor showed the most dramatic degradation (only 0.58 %–10.58 % remaining) after heat and UV treatments.

Alachlor, a selective pre-emergent herbicide, was widely used to control annual gramineae and broad-leaved weeds in soybean, peanut and rice fields in the late 20th century. At present, alachlor has been banned in many countries because of its teratogenicity and endocrine disrupting activity. In order to provide the data for the ecological and environmental risk assessment of alachlor, this paper reviews research advance on the toxicological of alachlor to non-target organisms after alachlor enters the environment, mainly including acute toxicity, chronic toxicity and oxidative stress effect. [ABSTRACT FROM AUTHOR]

Background and Objective: Milk is one of the most important components of human food. In recent decades, the continued use of pesticides has led to contamination of soil, water, air and milk and caused public concern in the community. Long-term exposure to pesticide residuals in the food chain can be harmful. Therefore, there is a need to control environmental conditions in order to improve its healthy and sustainable food processing practices. Materials and Methods: In this study, 30 samples of raw milk were randomly collected in October 2020, from milk collection centers in Urmia and the residual pesticides were determined using gas chromatography–mass spectrometry (GC-MS). Results: Organochlorine pesticides were detected in some raw milk samples. The highest concentrations of Lindane (γ-HCH) were detected with the values ranging from 0.3 to 0.6 mg/kg in 5 milk samples. Atrazine was detected in 15 samples with the values ranging from 0.8 to 1.33 mg/kg and alachlor was found in 13 samples with the varied range of 0.35 to o.5 mg/kg. Organochlorine pesticide concentrations were higher than maximum residue level (MRL) in all contaminated milk samples according to the values mentioned by the European Union. Conclusion: This study showed that atrazine, lindane and alachlor were higher than MRL according to European Commission (EC). However, other organochlorine pesticides such as Heptachlor, Aldrin and hexachlorocyclohexane (HCH) isomers (α, β and γ) were not detected. [ABSTRACT FROM AUTHOR]

The WHO International Programme on Chemical Safety (IPCS) framework for analyzing the relevance of a cancer mode of action (MoA) for humans (IPCS cancer-HRF) is an application to assess human relevance of tumorigenic hazards found through rodent bioassays. The chloroacetanilide herbicides, butachlor and alachlor, induced enterochromaffin-like (ECL) cell tumors in rat stomachs, at the highest doses. This study analyzed the human relevance of this tumor by applying the IPCS cancer-HRF using published data. In a postulated MoA, early key events (KEs) included decreased mucosal thickness in the fundic region, due to reduced parietal cells. The following KEs included increased pH of gastric acid and hypergastrinemia, leading to enhanced cell proliferation and hyperplasia, and resulting in the outcome of an ECL cell tumor. The data showed consistencies in dose-response and temporal concordance with the KEs and specificity in the tumor response, providing strengthened evidence of the KEs. While the early KE was not the same, similar MoAs have already been established for omeprazole and ciprofloxacin. The integrated data indicated that the postulated MoAs were biologically plausible. Alternative MoAs were excluded.. Based on sufficient evidence, an MoA was established in rats. When addressing chemically inducible MoAs of human relevance, KEs of hypergastrinemia and trophic ECL cell hyperplasia were judged to not be qualitatively and quantitatively plausible in humans. The MoA in rats is unlikely to be present in humans; however, the potential effects on parietal cells cannot be excluded. Thus, the IPCS cancer-HRF is very useful for assessing human relevance. [ABSTRACT FROM AUTHOR]

A molecularly imprinted solid-phase extraction (MISPE) procedure was developed for the GC-MS analysis of four high priority pesticides (atrazine, terbuthylazine, acetochlor and alachlor) in a cannabis bud sample matrix. The study demonstrated that the synthesised polymer had a high affinity and good selectivity for either chloroacetamide or triazine classes of pesticide used as a template molecule during the molecularly imprinted polymerisation reaction. The MISPE procedure was optimised in terms of loading, washing and elution fractions utilising a range of aqueous methanol solutions for optimal recovery and minimal matrix interferences. The optimal wash fraction was 20% (v/v) methanol in an aqueous solution, whilst 70% (v/v) was used for the elution fraction. The selectivity, accuracy and recovery of the MISPEs were verified using a synthesised non-imprinted polymer and a commercial C18 cartridge as reference sorbents in comparative experiments. Approximately 3 g of the cannabis bud sample was spiked at a 0.05 mg/kg maximum residue limit (MRL) concentration. The recovery of the four selected pesticides extracted from the spiked samples ranged between 76.4-85.0% when utilising the optimised MISPE methods, compared to 91.6-96.9% for the C18 SPE. However, the use of the MISPE resulted in enhanced selectivity, as evidenced by GC-MS analysis, due to the extraction of less matrix interferences. Therefore, it can be concluded that the MISPE is a viable pre-treatment method for selective pesticide analysis in cannabis flowers using GC-MS when selectivity is valued for the extraction of target pesticides from a complex sample matrix. [ABSTRACT FROM AUTHOR]

• Assessment of an hybrid ozonation/anodic oxidation monophasic process. • Enhancement of the ozone decomposition rate by the hybrid process. • Enhancement of the alachlor parent molecule degradation rate by the hybrid process. • Low influence of the hybrid process on the mineralization rate. • Pulse reinjections of ozone allows to enhance even more alachlor degradation rate. This prospective study assessed a hybrid process that combines ozonation with anodic oxidation (AO/O 3) with two boron-doped diamond (BDD) electrodes to treat a model aqueous solution containing 30 ppm of alachlor at pH 5 in a phosphate buffer. An innovative monophasic configuration, operated batch-wise, in which an ozone-stock solution was injected at t 0 in the electrochemical reactor, was proposed in order to avoid introduction of ozone-enriched gas bubbles. The alachlor parent molecule was almost entirely degraded within around 150 min of reaction time by anodic oxidation alone, whatever the applied current intensity (200, 500 and 800 mA). The mineralization efficiency varied from 50 % at 200 mA to 80 % at 800 mA after 120 min. The results emphasized that the anodic oxidation was a diffusion-controlled process. Addition of ozone at a low ozone dose of 1.9–2.3 mol of ozone per mol of alachlor allowed to decrease the ozone half-life time 2.7 times with the hybrid process compared to ozonation alone. This faster ozone consumption was concomitant with an enhanced alachlor degradation rate, with a corresponding half-life time around two-times lower. However, owing to the low ozone dose applied and the short ozone lifetime in solution (around 25–30 min), similar mineralization efficiencies were noticed for both AO/O 3 and AO processes. Thus, the application of pulse ozone-stock solution re-injections every 20 min to prolong the ozone exposure was assessed to overcome this limitation. However, the effect on the mineralization rate remained small, even if it allows to enhance even more the alachlor parent molecule degradation rate. The low influence of the hybrid process on the mineralization rate was attributed to the production of aliphatic fatty acids by-products that are poorly reactive with hydroxyl radicals, and whose the degradation by AO is the rate limiting step. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aimed to synthesise TiO2 nanoparticles (NPs) in pure rutile structure at moderate temperature without calcination and use them as the catalyst for alachlor removal under UV-C radiation. The crystal structure, composition, and particle size of the synthesised TiO2 NPs were analysed using an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The XRD spectra revealed the production of pure rutile TiO2. The individual and interactive effects of initial alachlor concentration (15–75 mg/L), TiO2 concentration (25–125 mg/L), pH (3–11), temperature (20–40 °C) and reaction time (15–75 min) on alachlor removal were investigated using the central composite design model based on the response surface methodology for experimental design, modelling and process optimization. The analysis of variance and multiple linear regression showed a good fit of the experimental data to the second-order polynomial model, with a coefficient of determination (R2) value of 0.8176 and a model F-value of 19.55975, implying that the model was significant. The results showed that decrease in pH and the initial alachlor concentration and increase in TiO2 concentration resulted in an increase in alachlor removal rate. The maximum rate of alachlor removal (98.44%) at optimum conditions occurred at pH = 5, alachlor = 30 mg/L, TiO2=100 mg, temperature = 35 °C and reaction time = 60 min.

This work investigates the adsorption mechanism of alachlor and pentachlorobenzene on chars (hydrochars and biochars) originated from Miscanthus giganteus and sugar beet shreds. Two different processes were used: hydrothermal conversion at three temperatures (180, 200, and 220 °C) and slow pyrolysis at 400 °C. Specific surface area (SSA) for all investigated chars ranged 3.87–260 m2/g, whereby biochars had a higher SSA. For hydrochars from sugar beet shreds, both the SSA (3.87–5.53 m2/g) and pore volume (0.023–0.0277 cm3/g) increased with increasing temperature, while the opposite trend was observed for hydrochars from miscanthus. The opposite trend could be a consequence of the different chemical composition of the used feedstock such as hemicelluloses and cellulose which can produce volatile organic products at higher temperatures and may cause the reduction of SSA. All adsorption isotherms were well described by the Freundlich model. The nonlinearity of the isotherms ranged from 0.450 to 0.986. Kd values for both investigated compounds followed the order: hydrochars from sugar beet shred < hydrochars from miscanthus < biochars, implying that the SSA of the chars affects the adsorption mechanism. In general, all the investigated adsorbents demonstrated higher adsorption affinity for pentachlorobenzene in comparison with alachlor, implying that hydrophobic interactions enhanced the adsorption of the more hydrophobic organic compound. In addition, for all hydrochars, adsorption affinities for the smaller pentachlorobenzene are significantly greater than for the larger alachlor, probably due to its ability to better penetrate into the pores of the adsorbents. This type of research is necessary to obtain safe adsorbents for water remediation. [ABSTRACT FROM AUTHOR]

Alachlor is a chloroacetanilide herbicide, which is extensively used in agriculture globally. It is proposed that it is a carcinogen and an estrogen too. Earthworms are largely involved in increasing the soil fertility, and excess use of this herbicide may result in toxicity to burrowing organisms like earthworms. In this context, the current intent of the proposed work is to assess the toxicity of alachlor on Eisenia fetida. The lethal concentration (LC50) for alachlor was calculated on E. fetida as 251.28 ± 22.28 μg/cm2. The E. fetida were treated with LC50 concentration of alachlor for 24 h. Significant changes in morphology like whole body coiling, constricted body shape, fragmentation, and thinning of body and clitellar shrinkage were noticed in E. fetida exposed to alachlor for 24 h in comparison to their respective controls. Neurotoxicity of alachlor in E. fetida was evaluated by measuring the acetylcholinesterase (AChE) at 6, 12, 18, and 24 h respectively. Various biochemical biomarkers such as catalase (CAT), lipid peroxidation (LPO), and glutathione sulfotransferase (GST) were measured at 0, 6, 12, 18 and 24 h respectively. Significant differences in AChE, CAT, LPO, and GST were noted in both control and treated E. fetida at different time intervals. The current finding will be useful in laying the toxic effects of alachlor to non-target soil invertebrates. [ABSTRACT FROM AUTHOR]

Background: The chloroacetamide herbicides pretilachlor is an emerging pollutant. Due to the large amount of use, its presence in the environment threatens human health. However, the molecular mechanism of pretilachlor degradation remains unknown. Results: Now, Rhodococcus sp. B2 was isolated from rice field and shown to degrade pretilachlor. The maximum pretilachlor degradation efficiency (86.1%) was observed at a culture time of 5 d, an initial substrate concentration 50 mg/L, pH 6.98, and 30.1 °C. One novel metabolite N-hydroxyethyl-2-chloro-N-(2, 6-diethyl-phenyl)-acetamide was identified by gas chromatography-mass spectrometry (GC–MS). Draft genome comparison demonstrated that a 32,147-bp DNA fragment, harboring gene cluster (EthRABCDB2), was absent from the mutant strain TB2 which could not degrade pretilachlor. The Eth gene cluster, encodes an AraC/XylS family transcriptional regulator (EthRB2), a ferredoxin reductase (EthAB2), a cytochrome P450 monooxygenase (EthBB2), a ferredoxin (EthCB2) and a 10-kDa protein of unknown function (EthDB2). Complementation with EthABCDB2 and EthABDB2, but not EthABCB2 in strain TB2 restored its ability to degrade chloroacetamide herbicides. Subsequently, codon optimization of EthABCDB2 was performed, after which the optimized components were separately expressed in Escherichia coli, and purified using Ni-affinity chromatography. A mixture of EthABCDB2 or EthABDB2 but not EthABCB2 catalyzed the N-dealkoxymethylation of alachlor, acetochlor, butachlor, and propisochlor and O-dealkylation of pretilachlor, revealing that EthDB2 acted as a ferredoxin in strain B2. EthABDB2 displayed maximal activity at 30 °C and pH 7.5. Conclusions: This is the first report of a P450 family oxygenase catalyzing the O-dealkylation and N-dealkoxymethylation of pretilachlor and propisochlor, respectively. And the results of the present study provide a microbial resource for the remediation of chloroacetamide herbicides-contaminated sites. [ABSTRACT FROM AUTHOR]

Alachlor is a chloroacetanilide herbicide used to control annual grasses in grazing system and has been observed along with its metabolites in animal foodstuffs. Its residue violations in animal foodstuffs are increasing significantly and therefore, useful and efficient assay is required. In this study, a rapid, useful, routine, and sensitive liquid chromatography with tandem mass spectrometry for simultaneously determining and confirming alachlor and its metabolites (2‐chloro‐N‐(2,6‐diethylphenyl) acetamide, 2,6‐diethylaniline, and 2‐ethyl‐6‐(1‐hydroxyethyl) aniline) in beef muscle, liver, milk, and egg samples was examined. The proposed method uses a simple extraction with methanol followed by dispersive and solid‐phase extraction cleanup. Observably, absolute calibration curves were linear from the limit of quantification to 100 ng/mL (r2 > 0.999). The recovery values fortified at 0.02 and 0.2 μg/g ranged from 70.4 to 107.6% with a relative standard deviation ≤ 7.1%. Alachlor and its metabolites in applied samples from Japanese markets were undetected using developed method. We examined the useful and efficient method and sample preparation scheme for actual and rational process of alachlor's residue. [ABSTRACT FROM AUTHOR]

'Transiting Exoplanet Survey Satellite' photometry of 10 young stars with very complex periodic light curves is considered. Previous findings that these cannot be due to dark surface spots are re-evaluated by allowing arbitrarily shaped areas on the stellar surface to have sub-photospheric fluxes. This is done by approximating flux integrals by sums over surface elements. The unknown ratios of spot to photospheric fluxes are determined by lasso or ridge regression procedures. It is found that almost all light curves can be modelled very accurately in this way. The usual, if rarely stated, caveat applies – star-spot models presented in the paper are not unique. [ABSTRACT FROM AUTHOR]

Gliomas are infiltrative neoplasms with a highly invasive nature. Due to its distinct genomic, genetic and epigenetic features, the immune prognostic signature (IPS) and immune microenvironment of glioblastoma (GBM) merit further research. We aimed to explore prognosis‐related immune genes and develop an IPS model for predicting prognosis in GBM. RNA‐sequencing data, as well as clinical information, from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) public cohorts were analyzed. To develop the IPS, least absolute shrinkage and selection operator (LASSO) Cox analysis was performed for immune‐related genes that were differentially expressed between GBM and normal tissues. Then, interaction effects of the IPS on the immune microenvironment were systematically analyzed; the precise prognostic model was developed based on the IPS and clinical data and was then further validated. A total of 21 immune prognostic genes were identified based on GBM microenvironment status. An 8‐gene IPS was established, and the GBM patients were effectively stratified into low‐ and high‐risk groups in the TCGA cohort as a training set. Univariate and multivariate Cox analyses revealed that IPS was an independent prognostic factor, and the prognostic performance of individual IPS genes was systematically illustrated. In addition, a comprehensive and novel nomogram model was initially established to estimate overall survival in TCGA‐GBM patients, and high‐risk patients had higher levels of dendritic cell and neutrophil infiltration. Furthermore, the nomogram model was developed and validated in the CGGA validation set. The low‐risk IPS was linked to a stronger response to anti‐PD‐L1 immunotherapy and clinical advantages in the IMvigor210 cohort. This novel IPS with promising biomarkers classifies GBM patients into subgroups with distinct clinical outcomes and immunophenotypes. Our findings and this resource may help to characterize the immune microenvironment, inform cancer immunotherapy and facilitate the development of precision immuno‐oncology. [ABSTRACT FROM AUTHOR]

Metabolomics strategy was perform to identify the novel serum biomarkers linked to schizophrenia with the assistance of transcriptomics analysis. Two analytical platforms, UPLC-Q-TOF MS/MS and 1H NMR, were used to acquire the serum fingerprinting profiles from a total of 112 participants (57 healthy controls and 55 schizophrenia patients). The differential metabolites were primarily selected after statistical analyses. Meanwhile, GSE17612 dataset downloaded from GEO database was implemented WGCNA analysis to discover crucial genes and corresponding biological processes. Based on metabolomics analysis, the metabolic distinctions were explored under the aid of transcriptomics. Then using Boruta algorithm identified the biomarkers, and LASSO regression analysis and Random Forest algorithm were used to evaluate the performance of the diagnostic model constructed by biomarkers selected. A total of four metabolites (α-CEHC, neuraminic acid, glyceraldehyde and asparagine) were selected as the biomarkers to establish diagnosis model. The performance of this model showed a higher accuracy rate to distinguish schizophrenia patients from healthy controls (area under the receive operating characteristic curve, 0.992; precision recall curve, 1.000, the mean accuracy of random forest algorithm, 95.00%). A four–biomarker model (α-CEHC, neuraminic acid, glyceraldehyde and asparagine) seems to be a good model for diagnosing schizophrenia patients. It might be helpful to guide the future studies on permitting early intervention designed to prevent disease progression. Image 1 • Metabolomics strategy was applied to select the novel biomarkers associated with schizophrenia under the aid of transcriptomics analysis. • α-CEHC, neuraminic acid, glyceraldehyde and asparagine were identified and used to establish the diagnostic panel. • The diagnostic model had better performance in distinguishing schizophrenia patients from healthy people than traditional method (WHO-DAS score). [ABSTRACT FROM AUTHOR]

Background: Social-environmental data obtained from the US Census is an important resource for understanding health disparities, but rarely is the full dataset utilized for analysis. A barrier to incorporating the full data is a lack of solid recommendations for variable selection, with researchers often hand-selecting a few variables. Thus, we evaluated the ability of empirical machine learning approaches to identify social-environmental factors having a true association with a health outcome.Methods: We compared several popular machine learning methods, including penalized regressions (e.g. lasso, elastic net), and tree ensemble methods. Via simulation, we assessed the methods' ability to identify census variables truly associated with binary and continuous outcomes while minimizing false positive results (10 true associations, 1000 total variables). We applied the most promising method to the full census data (p = 14,663 variables) linked to prostate cancer registry data (n = 76,186 cases) to identify social-environmental factors associated with advanced prostate cancer.Results: In simulations, we found that elastic net identified many true-positive variables, while lasso provided good control of false positives. Using a combined measure of accuracy, hierarchical clustering based on Spearman's correlation with sparse group lasso regression performed the best overall. Bayesian Adaptive Regression Trees outperformed other tree ensemble methods, but not the sparse group lasso. In the full dataset, the sparse group lasso successfully identified a subset of variables, three of which replicated earlier findings.Conclusions: This analysis demonstrated the potential of empirical machine learning approaches to identify a small subset of census variables having a true association with the outcome, and that replicate across empiric methods. Sparse clustered regression models performed best, as they identified many true positive variables while controlling false positive discoveries. [ABSTRACT FROM AUTHOR]

Background: The advent of metagenomic sequencing provides microbial abundance patterns that can be leveraged for sample origin prediction. Supervised machine learning classification approaches have been reported to predict sample origin accurately when the origin has been previously sampled. Using metagenomic datasets provided by the 2019 CAMDA challenge, we evaluated the influence of variable technical, analytical and machine learning approaches for result interpretation and novel source prediction. Results: Comparison between 16S rRNA amplicon and shotgun sequencing approaches as well as metagenomic analytical tools showed differences in normalized microbial abundance, especially for organisms present at low abundance. Shotgun sequence data analyzed using Kraken2 and Bracken, for taxonomic annotation, had higher detection sensitivity. As classification models are limited to labeling pre-trained origins, we took an alternative approach using Lasso-regularized multivariate regression to predict geographic coordinates for comparison. In both models, the prediction errors were much higher in Leave-1-city-out than in 10-fold cross validation, of which the former realistically forecasted the increased difficulty in accurately predicting samples from new origins. This challenge was further confirmed when applying the model to a set of samples obtained from new origins. Overall, the prediction performance of the regression and classification models, as measured by mean squared error, were comparable on mystery samples. Due to higher prediction error rates for samples from new origins, we provided an additional strategy based on prediction ambiguity to infer whether a sample is from a new origin. Lastly, we report increased prediction error when data from different sequencing protocols were included as training data. Conclusions: Herein, we highlight the capacity of predicting sample origin accurately with pre-trained origins and the challenge of predicting new origins through both regression and classification models. Overall, this work provides a summary of the impact of sequencing technique, protocol, taxonomic analytical approaches, and machine learning approaches on the use of metagenomics for prediction of sample origin. [ABSTRACT FROM AUTHOR]

Background: VHL mutation is the most common mutation in clear cell renal cell carcinoma (ccRCC). Here, we developed and validated an immune-related signature to predict the prognosis of ccRCC with VHL mutations. Methods: VHL mutation status and RNA expression were analysed in the TCGA datasets and our cohort. LASSO Cox analysis was performed to develop an immune-related signature. Candidate genes for the immune-related signature were differentially expressed between VHLwt and VHLmut ccRCC patients. Results: VHL mutations resulted in the downregulation of the immune response in ccRCC. To develop an immune-related signature, LASSO Cox analysis was constructed by immune-related genes that were differentially expressed between VHLwt (WHL wild type) and VHLmut (VHL mutation) ccRCC patients. The signature was developed and validated in the TCGA and our own cohort to classify patients into groups based on having a low or high risk of poor survival. Functional enrichment analysis showed that the immune-related pathway represented the major function and pathway. In addition, patients in the high-risk group had a positive correlation with low fractions of CD4 + T cells and dendritic cells and presented a lower expression of CTLA-4 and PD-1 than the low-risk group. Conclusion: In this study, we proposed a novel immune-related signature, which is a feasible biomarker for predicting the overall survival in VHLmut patients with ccRCC. [ABSTRACT FROM AUTHOR]

The aim of this paper is to forecast monthly crude oil price with a hierarchical shrinkage approach, which utilizes not only LASSO for predictor selection, but a hierarchical Bayesian method to determine whether constant coefficient (CC) or time-varying parameter (TVP) predictive regression should be employed in each out-of-sample forecasting step. This newly developed method has the advantages of both model shrinkage and automatic switch between CC and TVP forecasting models; thus, this may produce more accurate predictions of crude oil prices. The empirical results show that this hierarchical shrinkage model can outperform many commonly used forecasting benchmark methods, such as AR, unobserved components stochastic volatility (UCSV), and multivariate regression models in forecasting crude oil price on various forecasting horizons. [ABSTRACT FROM AUTHOR]

Dysregulated metabolic pathways have been appreciated to be intimately associated with tumorigenesis and patient prognosis. Here, we sought to develop a novel prognostic signature based on metabolic pathways in patients with primary oral squamous cell carcinoma (OSCC). The original RNA-seq data of OSCC from The Cancer Genome Atlas (TCGA) project and Gene Expression Omnibus (GEO) database were transformed into a metabolic pathway enrichment score matrix by single-sample gene set enrichment analysis (ssGSEA). A novel prognostic signature based on metabolic pathways was constructed by LASSO and stepwise Cox regression analysis in the training cohort and validated in both testing and validation cohorts. The optimal cut-off value was obtained using the Youden index by receiver operating characteristic (ROC) curve. The overall survival curves were plotted by the Kaplan-Meier method. A time-dependent ROC curve analysis with 1, 3, 5 years as the defining point was performed to evaluate the predictive value of this prognostic signature. A 5-metabolic pathways prognostic signature (5MPS) for OSCC was constructed which stratified patients into subgroups with favorable or inferior survival. It served as an independent prognostic factor for patient survival and had a satisfactory predictive performance for OSCC. Our results developed a novel prognostic signature based on dysregulated metabolic pathways in OSCC and provided support for aberrant metabolism underlying OSCC tumorigenesis. [ABSTRACT FROM AUTHOR]