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[Display omitted] • Different chloro-substituted phenylurea herbicides (DIU/CHL) can interact with BSA. • Fluorescence quenching of BSA by DIU/CHL results from static and dynamic quenching. • DIU/CHL has higher affinity for subdomain IIA (Site I) of BSA than subdomain IIIA. • Binding strength of DIU-BSA with two chlorine substituents is greater than CHL-BSA. • DIU can destroy the secondary structure of BSA greater than CHL by CD spectra. In this work, the interaction between different chloro-substituted phenylurea herbicides (diuron (DIU) and chlortoluron (CHL)) and BSA were investigated and compared at three different temperatures (283 K, 298 K and 310 K) adopting UV–vis, fluorescence, and circular dichroism spectra. The quenching mechanism of the interaction was also proposed. The energy transfer between BSA and DIU/CHL was investigated. The binding sites of DIU/CHL and BSA and the variations in the microenvironment of amino acid residues were studied. The changes of the secondary structure of BSA were analyzed. The results indicate that both DIU and CHL can significantly interact with BSA, and the degree of the interaction between DIU/CHL and BSA increases with the increase of the DIU/CHL concentration. The fluorescence quenching of BSA by DIU/CHL results from the combination of static and dynamic quenching. The DIU/CHL has a weak to moderate binding affinity for BSA, and the binding stoichiometry is 1:1. Their binding processes are spontaneous, and hydrophobic interaction, hydrogen bonds and van der Waals forces are the main interaction forces. DIU/CHL has higher affinity for subdomain IIA (Site I) of BSA than subdomain IIIA (Site II), and also interacts with tryptophan more than tyrosine residues. The energy transfer can occur from BSA to DIU/CHL. By comparison, the strength of the interaction of DIU-BSA is always greater than that of CHL-BSA, and DIU can destroy the secondary structure of BSA molecules greater than CHL and thus the potential toxicity of DIU is higher due to DIU with more chlorine substituents than CHL. It is expected that this study on the interaction can offer in-depth insights into the toxicity of phenylurea herbicides, as well as their impact on human and animal health at the molecular level. [ABSTRACT FROM AUTHOR]

[Display omitted] • Disposable electrochemical sensor for diuron monitoring. • Simple and economical composite material based on graphite and ABS. • Food and environmental interest samples. • Disposable and low-cost sensor. • Voltammetric device for the determination of herbicides. Advances in the development of new composite materials and conductive filaments play a crucial role in making electrochemical devices low-cost and sustainable. In this regard, we introduce a streamlined, cost-effective, and environmentally sustainable approach to creating an effective composite material from recycling ABS waste. This method holds promise for future production of a conductive filament by integrating graphite into the ABS polymer matrix. This approach, combined with 3D printing technology, enables the creation of ready-to-use electrochemical sensors without the need for electrochemical surface treatment. The proposed devices were duly characterized using spectroscopic, imaging, and electrochemical techniques. Thus, a square wave voltammetry (SWV) method was optimized for the determination of the herbicide Diuron (DIU) using recycled sensors. The method presented two linear working ranges from 0.25 to 2.5 and from 5.0 to 20.0 µmol/L with a detection limit on the nanomolar scale (68.9 nmol/L) and a relative standard deviation of less than 3.1 %. The proposed method was applied to the analysis of sugar-cane juice and cachaça. The recovery values obtained for the spiked samples ranged from 99.8 to 110.8 %. These results make it feasible to apply the sensor for determining DIU in beverage samples. Furthermore, the recycled sensor proved to be free of interference from the matrix and other commonly used pesticides. Therefore, the applicability of the proposed sensor for sensitive and selective monitoring of DIU in beverage samples is highlighted. [ABSTRACT FROM AUTHOR]

To remove typical herbicide diuron effectively, a novel sludge-derived modified biochar (SDMBC600) was prepared using sludge-derived biochar (SDBC600) as raw material and Fe-Zn as an activator and modifier in this study. The physico-chemical properties of SDMBC600 and the adsorption behavior of diuron on the SDMBC600 were studied systematically. The adsorption mechanisms as well as practical applications of SDMBC600 were also investigated and examined. The results showed that the SDMBC600 was chemically loaded with Fe-Zn and SDMBC600 had a larger specific surface area (204 m2/g) and pore volume (0.0985 cm3/g). The adsorption of diuron on SDMBC600 followed pseudo-second-order kinetics and the Langmuir isotherm model, with a maximum diuron adsorption capacity of 17.7 mg/g. The biochar could maintain a good adsorption performance (8.88–12.9 mg/g) under wide water quality conditions, in the pH of 2–10 and with the presence of humic acid and six typical metallic ions of 0–20 mg/L. The adsorption mechanisms of SDMBC600 for diuron were found to include surface complexation, π–π binding, hydrogen bonding, as well as pore filling. Additionally, the SDMBC600 was tested to be very stable with very low Fe and Zn leaching concentration ≤0.203 mg/L in the wide pH range. In addition, the SDMBC600 could maintain a high adsorption capacity (99.6%) after four times of regeneration and therefore, SDMBC600 could have a promising application for diuron removal in water treatment.

A distributed parameter model and two lumped parameter models were used in order to find the rate-limiting step in the adsorption process of a herbicide (Diuron) by Moringa oleifera husks, a possible low-cost adsorbent. For that, four kinetics assays, differentiated by the initial Diuron concentration, were performed. Langmuir isotherm well represented the equilibrium data and through this evaluation, Moringa husks proved to be a potential adsorbent for Diuron removal from water. The internal mass transfer resistance, analysed as a distributed parameter model, was found to better represent the experimental data. This fact enabled the simulation of the process according to the variation of time and space, which contributed to the better understanding of the adsorption process. [ABSTRACT FROM AUTHOR]

Coastal ecosystems are exposed to multiple anthropogenic stressors. Effective management actions would be better informed from generalized predictions of the individual, combined and interactive effects of multiple stressors; however, few generalities are shared across different meta-analyses. Using an experimental study, we present an approach for analysing regression-based designs with generalized additive models that allowed us to capture nonlinear effects of exposure duration and stressor intensity and access interactions among stressors. We tested the approach on a globally distributed marine diatom, using 72 h photosynthesis and growth assays to quantify the individual and combined effects of three common water quality stressors; photosystem II-inhibiting herbicide exposure, dissolved inorganic nitrogen (DIN) enrichment and reduced light (due to excess suspended sediment). Exposure to DIN and reduced light generally resulted in additivity, while exposure to diuron and reduced light resulted in additive, antagonistic or synergistic interactions, depending on the stressor intensity, exposure period and biological response. We thus find the context of experimental studies to be a primary driver of interactions. The experimental and modelling approaches used here bridge the gap between two-way designs and regression-based studies, which provides a way forward to identify generalities in multiple stressor interactions. [ABSTRACT FROM AUTHOR]

Tedera is a drought-tolerant perennial forage legume introduced in Australia in 2006. In October 2018, T15-1218 Lanza®, the world's first tedera variety, was released by the Department of Primary Industries and Regional Development and Meat & Livestock Australia for commercial use. A key agronomic practise for the successful establishment and adoption of tedera is to have a robust herbicide package to control a range of grass and broadleaf weeds well tolerated by tedera. A total of 9 pre-emergent and 44 post-emergent herbicide treatments were evaluated in eight experiments from 2017 to 2021. To control grasses such as annual ryegrass (Lolium rigidum Gaud.), propyzamide and carbetamide can be recommended for pre- or post-emergent applications and butroxydim, clethodim, and haloxyfop for post-emergent applications. The broadleaf pre-emergent herbicides recommended are clopyralid to control emerged capeweed (Arctotheca calendula (L.) Levyns), fomesafen to control pre-emergent wild radish (Raphanus raphanistrum L.), and the double mix of fomesafen + diuron, flumetsulam + diuron, and the triple mix of fomesafen + diuron + flumetsulam to control pre-emergent capeweed, pre- and post-emergent wild radish, and other broadleaf weeds. The most consistently well tolerated post-emergent herbicides by tedera seedlings and adult plants were diflufenican, diuron, flumetsulam, fomesafen, and their two- or three-way mixes that will provide good control of capeweed and wild radish. Desiccants such as paraquat or diquat were also well tolerated by 1-year-old tedera plants that recovered after being desiccated. [ABSTRACT FROM AUTHOR]

Effect-directed analysis (EDA) aims at identifying the compound(s) responsible for toxicity in a complex environmental sample where several dozens of contaminants can be present. In this study, we used an environmental mixture extracted from the Polar Organic Chemical Integrative Sampler (POCIS) previously immersed downstream a landfill (River Ponteils, South West France), to perform an EDA approach using a microalgal bioassay based on the photosynthetic capacities of diatom (Nitzschia palea) cultures. Adverse effects on photosynthetic capacities were recorded when algae were exposed to the entire POCIS extract (> 85% inhibition at the highest concentration tested). This result was coherent with the detection of diuron and isoproturon, which were the 2 most concentrated herbicides in the extract. However, the EDA process did not allow pointing out the specific compound(s) responsible for the observed toxicity but rather suggested that multiple compounds were involved in the overall toxicity and caused mixture effects. [ABSTRACT FROM AUTHOR]

Freshwater biofilms have been increasingly used during the last decade in ecotoxicology due to their ecological relevance to assess the effect(s) of environmental stress at the community level. Despite growing knowledge about the effect of various stressors on the structure and the function of these microbial communities, a strong research effort is still required to better understand their response to chemical stress and the influence of environmental stressors in this response. To tackle this challenge, untargeted metabolomics is an approach of choice because of its capacity to give an integrative picture of the exposure to multiple stress and associated effect as well as identifying the molecular pathways involved in these responses. In this context, the present study aimed to explore the use of an untargeted metabolomics approach to unravel at the molecular/biochemical level the response of the whole biofilm to chemical stress and the influence of various environmental factors in this response. To this end, archived high-resolution mass spectrometry data from previous experiments at our laboratory on the effect of the model photosynthesis inhibitor diuron on freshwater biofilm were investigated by using innovative solutions for OMICs data (e.g., DRomics) and more usual chemometric approaches (multivariate and univariate statistical analyses). The results showed a faster (1 min) and more sensitive response of the metabolome to diuron than usual functional descriptors, including photosynthesis. Also, the metabolomics response to diuron resulted from metabolites following various trends (increasing, decreasing, U/bell shape) along increasing concentration and time. This metabolomics response was influenced by the temperature, photoperiod, and flow. A focus on a plant-specific omega-3 (eicosapentaenoic acid) playing a key role in the trophic chain highlighted the potential relevance of metabolomics approach to establish the link between molecular alteration and ecosystem structure/functioning impairment but also how complex is the response and the influence of all the tested factors on this response at the metabolomics level. Altogether, our results underline that more fundamental researches are needed to decipher the metabolomics response of freshwater biofilm to chemical stress and its link with physiological, structural, and functional responses toward the unraveling of adverse outcome pathways (AOP) for key ecosystem functions (e.g., primary production). [ABSTRACT FROM AUTHOR]

Atrazine and Diuron are widely used herbicides. The use of pesticides contaminates the aquatic environment, threatening biodiversity and non-target organisms such as fish. In this study, we investigated the effects of acute exposure for 96 h hours to atrazine and diuron commercial formulations in zebrafish (Danio rerio , wild-type AB) embryos and larvae and adult stages. We observed a significant concentration-dependent survival decrease and hatching delays in animals exposed to both herbicides and in the frequency of malformations compared to the control groups. Morphological defects included cardiac edema, tail reduction, and head malformation. At 7 days post-fertilization (dpf), atrazine exposure resulted in a reduction in the head length at 2, 2.5, and 5 mg/L and increased the ocular distance at 1, 2, 2.5, and 5 mg/L atrazine when compared to controls. At the same age, diuron increased the ocular distance in animals exposed to diuron (1.0 and 1.5 mg/L) and no effects were observed on the head length. We also evaluated a behavioral repertoire in larvae at 7 dpf, and there were no significant differences in distance traveled, mean speed, time in movement, and thigmotaxis for atrazine and diuron when animals were individually placed in a new environment. The cognitive ability of the larvae was tested at 7 dpf for avoidance and optomotor responses, and neither atrazine nor diuron had significant impacts when treated groups were compared to their corresponding controls. Adults' behavior was evaluated 7 and 8 days after the end of the acute herbicide exposure. Exploration of a new environment and associated anxiety-like parameters, social interaction, and aggressiveness were not altered. Our results highlight the need for further studies on the sublethal effects of both herbicides and the consideration of the effects of commercial formulas vs. isolated active ingredients. It also emphasizes the need to take sublethal effects into consideration when establishing the environmental limits of residues. [ABSTRACT FROM AUTHOR]

"Musty" off‐flavor in pond‐raised Channel Catfish Ictalurus punctatus can result in an unpalatable and unmarketable product for catfish farmers in the southern United States. Certain species of cyanobacteria (blue‐green algae) in the catfish ponds produce 2‐methylisoborneol (MIB), which accumulates in the Channel Catfish flesh and causes musty off‐flavor. One management approach available to United States catfish farmers is the application of algicides to ponds to reduce the abundance of noxious cyanobacteria. Diuron is one approved algicide to specifically manage MIB‐related off‐flavor caused by the common cyanobacterium Planktothrix perornata f. attenuata. In this study, three commercial ponds determined in the early summer to contain musty off‐flavor Channel Catfish were monitored over approximately 2 months to determine the impact and pattern of weekly diuron applications on the abundance of P. perornata, chlorophytes (green algae), MIB concentrations in the pond water, and flavor characteristics of the sampled Channel Catfish collected during the treatment period. After several diuron applications to each pond, the abundance of P. perornata and MIB concentrations in pond water decreased dramatically. Channel Catfish in each pond were determined to be "on‐flavor" approximately 2 months after the initial diuron application. This study demonstrates that diuron applied via label‐specified treatment protocols provides catfish farmers with a practical management approach for P. perornata and subsequent MIB‐related off‐flavor. [ABSTRACT FROM AUTHOR]

Nickel(II) tetrasulfonated phthalocyanine (p-NiTSPc)-modified carbon fiber microelectrode (CFME) was used for the first time to investigate the electrochemical quantification of diuron in an agrochemical formulation. The surface morphology and elementary analysis of unmodified carbon fiber microelectrode (CFME) and p-NiTSPc-CFME were performed using atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX), respectively. Cyclic voltammetry (CV) was used to investigate the electrochemical behaviour of diuron, while square wave voltammetry (SWV) was used for quantitative analysis of diuron. Upon variation of some key analytical parameters, a calibration curve was plotted in the concentration range from 21.450 to 150.150 μM, leading to a detection limit (DL) of 8.030 μM mg/L (3.3σ/m) and a limit of quantification (LQ) of 20.647 μM mg/L. The fabricated p-NiTSPc-CFME was successfully applied for quality control in a commercialized formulation of diuron. The standard additional method was used, and the recovery rate of diuron was found to be 98.4%. [ABSTRACT FROM AUTHOR]

The concentration data and toxicity data of seven booster biocides were collected, and a tiered assessment was performed to evaluate their ecological risk. Results indicated that Diuron and Irgarol 1051 had the highest concentrations; Irgarol 1051 and GS26575 were the most toxic. A tiered risk assessment implied that the risk of six biocides and one degradation product followed the order: Irgarol 1051 > GS26575 > Diuron (or Diuron > GS26575) > DCOIT > Dichlofluanid ≈ Chlorothalonil > BIT. Apparently, the top three biocides with the highest risk were Irgarol 1051, GS26575 and Diuron. The 70.6%, 33.3% and 6.76% concentration data of Irgarol 1051, GS26575 and Diuron behaved high risk, respectively. They could impact 2.54%-14.4% species in the common case, and impact 7.08%-48.1% species in the worst case. Irgarol 1051 posed great risk to China, Brazil and UK; GS26575 posed no significantly different risk to different countries; Diuron posed high risk to Spain and Italy. [ABSTRACT FROM AUTHOR]

Methods to predict the equilibrium solubility of nonelectrolyte solids are indispensable for early-stage process development, design, and feasibility studies. Conventional analytic methods typically require reference data to regress parameters, which may not be available or limited for novel systems. Molecular simulation is a promising alternative, but is computationally intensive. Here, we demonstrate the ability to use a small number of molecular simulation free energy calculations to generate reference data to regress model parameters for the analytical MOSCED (modified separation of cohesive energy density) model. The result is an efficient analytical method to predict the equilibrium solubility of nonelectrolyte solids. The method is demonstrated for the wastewater contaminants monuron, diuron, atrazine and atenolol. Predictions for monuron, diuron and atrazine are in reasonable agreement with MOSCED parameters regressed using experimental solubility data. Predictions for atenolol are inferior, suggesting a potential limitation in the adopted molecular models, or the solvents selected to generate the necessary reference data. [ABSTRACT FROM AUTHOR]

Copyright of Taiwanese Journal of Agricultural Chemistry & Food Science is the property of Agricultural Chemical Society of Taiwan 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.)

Herbicide mixtures have often been used to control weeds in crops worldwide, but the behavior of these mixtures in the environment is still poorly understood. Laboratory and greenhouse tests have been conducted to study the interaction of the herbicides diuron, hexazinone, and sulfometuron-methyl which have been applied alone and in binary and ternary mixtures in the processes of sorption, desorption, half-life, and leaching in the soil. A new index of the risk of leaching of these herbicides has also been proposed. The sorption and desorption study has been carried out by the batch equilibrium method. The dissipation of the herbicides has been evaluated for 180 days to determine the half-life (t1/2). The leaching tests have been carried out on soil columns. The herbicides isolated and in mixtures have been quantified using ultra-high performance liquid chromatography coupled to the mass spectrometer. Diuron, hexazinone, and sulfometuron-methyl in binary and ternary mixtures have less sorption capacity and greater desorption when compared to these isolated herbicides. Dissipation of diuron alone is slower, with a half-life (t1/2) = 101 days compared to mixtures (t1/2 between 44 and 66 days). For hexazinone and sulfometuron-methyl, the dissipation rate is lower in mixtures (t1/2 over 26 and 16 days), with a more pronounced effect in mixtures with the presence of diuron (t1/2 = 47 and 56 and 17 and 22 days). The binary and ternary mixtures of diuron, hexazinone, and sulfometuron-methyl promoted more significant transport in depth (with the three herbicides quantified to depth P4, P7, and P7, respectively) compared to the application of these isolated herbicides (quantified to depth P2, P4, and P5). Considering the herbicides' desorption and solubility, the new index proposed to estimate the leaching potential allowed a more rigorous assessment concerning the risk of leaching these pesticides, with hexazinone and sulfometuron-methyl presenting a higher risk of contamination of groundwater. [ABSTRACT FROM AUTHOR]

The Pacific oyster (Crassostrea gigas) is an important species in oyster farming worldwide, including in Japan. Hiroshima Bay is one of the most important oyster farming areas in Japan. We investigated the occurrence of antifouling biocides used worldwide including diuron, Irgarol 1051 (Irgarol), and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), which have been detected at sub-ppb levels in seawater in Japan, and estimated their no observed effect concentrations (NOECs). In recent years, the spat settlement of Pacific oysters has become poor, which presents a challenge for oyster aquaculture in Hiroshima Bay; hence, we conducted embryotoxicity and larva settlement tests using Pacific oysters. Compared to diuron and Irgarol, DCOIT exhibited a higher toxicity toward oyster embryos, and the minimum 24-h NOEC toxicity value for the oyster embryos was <3 ng/L. The highest concentrations of diuron, Irgarol, and DCOIT in the environmental seawater in the Seto Inland Sea were 27.6, 3.2, and 24 ng/L, respectively. Considering the NOECs, the environmental concentrations of these biocides suggest that the ecological risks posed by diuron and Irgarol are low, whereas those posed by DCOIT are high. However, the rate of detection of DCOIT was low because it degraded rapidly in the seawater before treatment for chemical analysis, except in the case of the treatment on the research vessel. [ABSTRACT FROM AUTHOR]

An electrochemical sensor was prepared by modification of glassy carbon electrode (GCE) with an organoclay obtained by intercalation of smectite‐type clay Sa(Na) with dimethydioctadecylammonium ions (DODAB) and polymer of alizarin red S (poly[ARS]). The synthesized materials were analyzed by physicochemical and electrochemical techniques. The fabricated sensor GCE/Sa(DODAB)/poly(ARS) was employed toward the detection of diuron and the detection limit was found to be 0.48 μM (0.11 mg/L). Additionally, the elaborated electrochemical sensor was found to exhibit good sensitivity, stability, and reproducibility toward the determination of diuron, and it was applied successfully in real samples. [ABSTRACT FROM AUTHOR]

Diuron is categorized as a probable human carcinogen by the United States Environmental Protection Agency (EPA). This work is aimed to determine the optimal conditions for the catalytic degradation of Diuron in an aqueous solution with H2O2 using Algerian sodium Montmorillonite (Mont‐Na) as the catalyst. The material is characterized before and after the experiment using X‐ray diffraction, Fourier transform infrared (FTIR) spectroscopy, specific surface area (SBET), elemental analysis, and thermal analysis (TGA/DTA). The surface charge is determined by measuring the point of zero charge. Tests with H2O2 without Mont‐Na provide a 32% conversion rate after 8 h. However, a mixture of 1 g Mont‐Na and H2O2 increases the conversion rate to 91% after 180 min at 25 °C and pH 6.3. The Diuron disappearance is evidenced by high‐performance liquid chromatography using a UV–vis detector (HPLC/UV–vis). Specifically, 3,4‐dichloroaniline (DCA) is the only by‐product. At the basic pH values 9 and 11, a conversion rate of 72.5% is achieved with a lower contact time of 150 min. A change in temperature toward higher values results in a decrease in the degradation rate. Overall, Algerian sodium Montmorillonite is used successfully for the heterogeneous catalytic degradation of Diuron from polluted water. [ABSTRACT FROM AUTHOR]

Chemical control is the main weed control method in garlic crops; however, this crop is sensitive to herbicides, which can cause injuries and decrease yield depending on the products used, application timing, rate, and cultivar. In this context, the objective of this study was to evaluate the selectivity of herbicides for garlic plants (cultivar Chonan), using different application timings. A greenhouse experiment was conducted in a completely randomized design with four replications. An 8×2 factorial arrangement was used, in which the first factor consisted of a control without herbicide and seven herbicides (linuron, diuron, pendimethalin, s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon) applied according to the second factor, application timings (preemergence or post-emergence). Phytotoxicity, photosynthetic rate, stomata morphometry, bulb diameter, and crop yield of garlic were evaluated. Pre-emergence applications were more selective than post-emergence applications. The herbicides linuron, diuron, s-metolachlor, and oxadiazon applied at pre-emergence, and s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon applied at post-emergence were not selective for the Chonan garlic cultivar. Pendimethalin presented the highest selectivity, regardless of the application timing. Oxyfluorfen and flumioxazin applied at pre-emergence and linuron and diuron applied at post-emergence were selective for the cultivar Chonan. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui 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.)

ABSTRACT The purpose of this study was to assess the effect of different herbicide treatments on moisture removal and calorific power of biomass sorghum for co-generation of electric energy through burning. The experiment was conducted in randomized complete block design with four replicates per treatment and a 6x4 factorial scheme (six herbicide treatments x four intervals between spraying and harvesting). The herbicide treatments were: two different doses of glyphosate (1.92 kg a.i. ha-1 and 3.84 Kg a.i. ha-1), paraquat (0.4 Kg a.i. ha-1), a commercial mixture of paraquat + diuron (0.6 + 0.3 Kg a.i. ha-1), glufosinate-ammonium (0.8 Kg a.i. ha-1) and control (unsprayed). The intervals between spraying and harvesting assessed were 7, 14, 21 and 28 days after desiccation (DAD). It was assessed: the number of leaves per plant, moisture content of leaves, panicles, culm and whole ground plants and Superior Calorific Power (SCP). The herbicides paraquat and paraquat + diuron promotes defoliation, after 14 DAD. Glyphosate, paraquat, paraquat + diuron and glufosinate-ammonium reduce leaf and panicle moisture, despite only glyphosate reduces moisture in the culm. The herbicides do not affect the SCP of biomass sorghum. Therefore, the herbicides, especially glyphosate, have high potential for pre-harvest desiccation in biomass sorghum.

Weeds in sugarcane have negatively affected the sugar yield rate. Several approaches have been carried out to overcome the weeds, including the usage of diuron as synthetic herbicide. However, the long-term usage of diuron is known to have a negative effect leads to the production of 3,4-Dichloroaniline responsible for soil leach and bioaccumulation. Therefore, this study aimed to find a potential natural herbicide. By mimicking the diuron's mode of action which inhibits the process of photosynthesis through blocking the Photosystem II protein D1 (psbA) of the weeds, fourteen compounds as potential candidate bioherbicides were virtually docked by PyRx v.0.9.5 software to the specific site. Three important species of the weeds were chosen including Eleusine indica, Praxelis clematidea, and Momordica charantia. The binding affinity score was further calculated and ranked to screen the top six compounds as bioherbicide candidates. Interaction of each complex and the biological activity prediction were then performed by Discovery Studio software and PASS server, respectively. Aurachin P, Aurachin A, and Cyanobacterin were placed in the top ranked compounds with high binding affinity score around -6 to -9 kcal mol-1 toward the psbA. The amino acid interaction involved in the complex shows 50-90% similar to the control, psbA and diuron complex. Besides, the biological activity prediction of Aurachin P, Aurachin A, and Cyanobacterin exhibits the terms related to the inhibition of photosynthesis process via enzymatic pathway. Thus, the active compounds might have inhibition action in the photosynthesis process and control the weeds in sugarcane.

Background: Substituted urea herbicide is widely used in the agricultural industry and is accessible to most people around the globe. Accidental or deliberate poisoning is an anticipated complication of these agrochemical products. Case presentation: We present a 15-year-old girl following deliberate self-ingestion of substituted urea herbicide (Diuron). She was diagnosed with Diuron induced methemoglobinemia and treated with intra venous methylene blue. Later she developed hemolytic anemia and needed 3 units of blood transfusions. Her haemolysis was thought to be due to methylene blue with concomitant Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency as no other possible cause was found for haemolysis. But on follow-up visits, G6PD deficiency was excluded by screening test and enzyme level assay. Conclusion: Heamolytic anemia is a possible rare complication that should be anticipated in patients presented with the significant amount of substituted urea herbicide poisoning. Studies have found the possibility of reactive oxygen species accumulation in cells leading to oxidative damage. But we were unable to find any reported cases of haemolysis in humans. We postulate that the inhibition of NADPH production like G6PD deficiency may be the key mechanism that causes haemolysis in humans by creating an acquired G6PD deficiency status in red blood cells. However, further studies are needed to identify the exact mechanism of hemolysis in humans.

Detection of autofluorescence parameters is a useful approach to gain insight into the physiological state of plants and algae, but the effect of reabsorption hinders unambiguous interpretation of in vivo data. The exceptional morphological features of Nitellopsis obtusa made it possible to measure autofluorescence spectra along single internodal cells and estimate relative changes in autofluorescence intensity in selected spectral regions at room temperatures, avoiding the problems associated with thick or optically dense samples. The response of algal cells to controlled white light and DCMU herbicide was analyzed by monitoring changes in peak FL intensity at 680 nm and in F680/F750 ratio. Determining the association between the selected spectral FL parameters revealed an exponential relationship, which provides a quantitative description of photoinduced changes. The ability to discern the effect of DCMU not only in the autofluorescence spectra of dark-adapted cells, but also in the case of light-adapted cells, and even after certain doses of excess light, suggests that the proposed autofluorescence analysis of N. obtusa may be useful for detecting external stressors in the field., (Creative Commons Attribution license.)

The use of biostimulants in the bioremediation of polluted soils in order to eliminate/reduce the toxic effects of pesticides on the soil is currently a very common environmental practice. In this study, we studied the bioremediation effect of three biostimulants obtained from sewage sludge by way of an enzymatic hydrolysis and fermentation process in a diuron-contaminated soil for 55 days under laboratory conditions. During this period of time, the enzymatic activities, bacterial community and the evolution of diuron in the soil were analyzed. Compared with the unpolluted soil, the application of diuron decreased the dehydrogenase, β-glucosidase and phosphatase activities by 60%, 40.7%, and 60.6%, respectively. The Gram-positive bacterial population was decreased by 48.5%, while the Gram-negative population was decreased by 57.7% and the fungal population was decreased by 54.3%. The application of the three biostimulants to the soil decreased the diuron concentration. However, this decrease was higher when the biostimulant obtained by enzymatic hydrolysis was applied. This may be due to the fact that this biostimulant contains a higher quality of low molecular weight proteins than the other two biostimulants obtained by fermentation processes.

Biodegradation was considered a promising and environmentally friendly method for treating environmental pollution caused by diuron. However, the mechanisms of biodegradation of diuron required further research. In this study, the degradation process of diuron by Achromobacter xylosoxidans SL-6 was systematically investigated. The results suggested that the antioxidant system of strain SL-6 was activated by adding diuron, thereby alleviating their oxidative stress response. In addition, degradation product analysis showed that diuron in strain SL-6 was mainly degraded by urea bridge cleavage, dehalogenation, deamination, and ring opening, and finally cis, cis -muconic acid was generated. The combined analysis of metabolomics and transcriptomics revealed the biodegradation and adaptation mechanism of strain SL-6 to diuron. Metabolomics analysis showed that after the strain SL-6 was exposed to diuron, metabolic pathways such as tricarboxylic acid cycle ( cis, cis -muconic acid), glutathione metabolism (oxidized glutathione), and urea cycle (arginine) were reprogrammed in the cells. Furthermore, diuron could induce the production of membrane transport proteins in strain SL-6 cells and overexpress antioxidant enzyme genes, finally ultimately promoting the up-regulation of genes encoding amide hydrolases and dioxygenases, which was revealed by transcriptomics studies. This work enriched the biodegradation mechanism of phenylurea herbicides and provided guidance for the removal of diuron residues in the environment and promoting agriculture sustainable development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hu, Qian, Wang, Sun, Wu, Zhang, Han, Wang, Ma and Yang.)

Dialdehyde cellulose (DAC) has considerable potential as an effective metal nanoparticle support material for the preparation of highly sensitive SERS substrates. In this study, a SERS substrate based on the Tollens reaction of DAC was successfully prepared. DAC was obtained by selective oxidation of cellulose nanocrystals (CNCs) with sodium periodate (NaIO4). And the aldehyde group of DAC underwent REDOX reaction with Tollens reagent to produce silver nanoparticles (Ag NPs) on the DAC in situ. The SERS "hot spots" can be generated in the gaps of Ag NPs. The as-prepared DAC-Ag NP nanocomposites showed excellent SERS activity with a highly sensitive rhodamine 6 G detection limit of 10–9 M. In diuron detection, an excellent linear relationship (R2 = 0.9948) was established between the concentrations of 10–8 M to 10–4 M. Furthermore, the feasibility of the proposed method in the actual samples was also confirmed. The substrate was applied to detect orange and persimmon peel which were previously treated with diuron solution. The substrate has universal applicability and is expected to be further applied in the detection of other hazardous molecules. [ABSTRACT FROM AUTHOR]

Biomass ashes like rice husk ash (RHA), bagasse fly ash (BFA), were used for aqueous phase removal of a pesticide, diuron. Response surface methodology (RSM) and artificial neural network (ANN) were successfully applied to estimate and optimize the conditions for the maximum diuron adsorption using biomass ashes. The effect of operational parameters such as initial concentration (10–30 mg/L); contact time (0.93–16.07 h) and adsorbent dosage (20–308 mg) on adsorption were studied using central composite design (CCD) matrix. Same design was also employed to gain a training set for ANN. The maximum diuron removal of 88.95 and 99.78% was obtained at initial concentration of 15 mg/L, time of 12 h, RHA dosage of 250 mg and at initial concentration of 14 mg/L, time of 13 h, BFA dosage of 60 mg respectively. Estimation of coefficient of determination (R2) and mean errors obtained for ANN and RSM (R2RHA = 0.976, R2BFA = 0.943) proved ANN (R2RHA = 0.997, R2BFA = 0.982) fits better. By employing RSM coupled with ANN model, the qualitative and quantitative activity relationship of experimental data was visualized in three dimensional spaces. The current approach will be instrumental in providing quick preliminary estimations in process and product development. [ABSTRACT FROM AUTHOR]

The most widely planted cotton (Gossypium hirsutum L.) and soybean [Glycine max (L.) Merr.] varieties in the United States are resistant to the herbicide dicamba. Measures to reduce selection pressure for dicamba‐resistant weeds is paramount. Four studies evaluated strategies to reduce selection pressure for Palmer amaranth (Amaranthus palmeri S. Watson) resistance to dicamba applied postemergence (POST) in cotton. A split‐plot arrangement consisted of conventional tillage or cereal rye (Secale cereale L.) cover crop as the whole plot. The subplot included four herbicide systems: no herbicide, 3 POSTs, fomesafen plus diuron applied pre‐emergence (PRE) followed by (fb) 3 POSTs, and PRE fb 2 POSTs fb diuron plus monosodium methyl arsenate applied lay‐by post‐directed (LPD). The POST herbicide applications were glyphosate plus dicamba. The cover crop reduced Palmer amaranth density 75, 70, and 54% at the time of POST 1, POST 2, and POST 3 application, respectively. Pre‐emergence herbicides fb POST applications reduced Palmer amaranth densities 99, 99, and 96% at the aforementioned application timings, respectively. Cover crop plus PRE herbicides provided similar reductions. Cumulative for the season, Palmer amaranth exposure to dicamba was reduced 65% by the cover crop, 98% by both PRE herbicides and cover crop plus PRE herbicides compared to 3 POST applications. An LPD application reduced Palmer amaranth exposure to dicamba by 38,319 plants ha–1 compared to a third POST. Cotton stand was higher in conventional systems when soil temperatures were 30–37 °C during emergence; however, stand in the cover crop was greater when soil temperatures were 40–43 °C. Yields were reduced 14% in a total POST herbicide program, and were improved 14% in a cover crop. A cereal rye cover crop and residual PRE herbicides had the biggest impact on reducing selection pressure for Palmer amaranth resistance to dicamba while also improving yield. Core Ideas: Herbicide‐resistant Palmer amaranth is a major pest in cropping systems across the United States.Integrated weed management tactics are needed to delay further weed resistance issues.Cover crops plus pre‐emergence herbicides reduced Palmer amaranth exposure to dicamba 98%.Replacing a third postemergence with a lay‐by reduced exposure to dicamba 38,319 plants ha‐1.Cotton yield was highest when utilizing a cover crop and pre‐emergence herbicides. [ABSTRACT FROM AUTHOR]

Irgarol 1051 and diuron are photosystem II inhibitors in agricultural activities and antifouling paints in the shipping sector. This study focused on three major ports (western, southern, and eastern) surrounding Peninsular Malaysia to construct the distribution of both biocides on the basis of the seasonal and geographical changes. Surface seawater samples were collected from November 2011 to April 2012 and pretreated using the solid-phase extraction technique followed by quantification with GC-MS and LC-MS-MS for Irgarol 1051 and diuron, respectively. Generally, the distribution of Irgarol 1051 was lowest during November 2011 and highest during April 2012, and similar patterns were observed at all ports, whereas the distribution of diuron was rather vague. The increasing pattern of Irgarol 1051 from time to time is probably related to its accumulation in the seawater as a result of its half-life and consistent utilization. On the basis of the discriminant analysis, the temporal distribution of Irgarol 1051 varied at Klang North Port, Klang South Port, and Pasir Gudang Port, whereas diuron was temporally varied only at Kemaman Port. Furthermore, Irgarol 1051 was spatially varied during November 2011, whereas diuron did not show any significant changes throughout all sampling periods. Ecological risk assessment exhibited a high risk for diuron and Irgarol 1051, but Irgarol 1051 should be of greater concern because of its higher risk compared to that of diuron. Thus, it is recommended that the current Malaysian guidelines and regulations of biocide application should be reevaluated and improved to protect the ecosystem, as well as to prevent ecological risks to the aquatic environment. [ABSTRACT FROM AUTHOR]

The 8‐km2 Morcille catchment, which is a sub‐catchment of the 150‐km2 Ardières catchment in the Beaujolais region of France, is one of the first sites in Europe where research has been conducted on surface water contamination by pesticides. A consolidated hydrological and chemical dataset has been set up with data collected since 2002 on the Morcille River and since 2011 on the Ardières River. Additional data on the ecotoxicological and ecological impacts of pesticides on aquatic microbial communities and macroinvertebrates has also been recorded in both rivers since 2005. The 'Site Atelier Ardières‐Morcille Dataset' described here combines rainfall and stream water height measurements at gauged stations with concentrations of two trace elements and nine pesticides (mainly herbicides, fungicides and some of their metabolites) in both the Ardières and Morcille rivers. All contaminant concentration data showed spatial and temporal variability in water quality associated with pesticide use and rainfall patterns. This long‐term monitoring framework made it possible to estimate the persistence of two herbicides (diuron and norflurazon) after legislation banning them. It took 4 years for diuron and more than 10 years for norflurazon concentrations to fall below 0.1 μg/L. Concurrent biological data showed a gradient of impacts consistent with chemical anthropogenic pressure, and rapid recovery of phototrophic microbial communities after the diuron ban. Finally, monitoring data on pesticide transport in a grassed strip set on a slope of the Morcille catchment confirmed that vegetative filter strips can effectively reduce diuron fluxes in surface runoff (>80% abatement) and infiltration water (>70% abatement). The full dataset offers a valuable resource for the validation of hydrological models and the development of global approaches to better understand the pressure–transport–exposure–impact chain and aquatic community resilience at the small catchment scale. [ABSTRACT FROM AUTHOR]

The photochemically induced fluorescence (PIF) method for the quantitative analysis of diuron herbicide in natural waters is described. The analytical parameters, namely solvent, pH and irradiation time, have been optimized. PIF method was developed for the determination of herbicide in methanol (MeOH) and ethanol (EtOH). The obtained calibration curves gave correlation coefficients close to unity, with low values of the limit of detection (LOD = 1.0–1.6 ng/mL) and limit of quantification (LOQ = 3.2–5.2 ng/mL). Analytical parameters (LOD, LOQ) obtained indicate a very good analytical sensitivity of the PIF method. Examples of application to the analysis of diuron herbicide in spiked surface and groundwater yielded satisfactory mean recoveries values (85.7–103.3%). The relative standard deviation values obtained in spiked draining and well waters samples are between 4.4 and 7.9%, which demonstrates good reproducibility of the PIF method. A significant decrease in the recovery rate of diuron in natural water samples as a function of soil depth was observed. Dissolved organic carbon (NPOC) leads to an increase in the recovery rate in spiked natural water. [ABSTRACT FROM AUTHOR]

A fundamental mystery of plant cell biology is the occurrence of "stromules," stroma-filled tubular extensions from plastids (such as chloroplasts) that are universally observed in plants but whose functions are, in effect, completely unknown. One prevalent hypothesis is that stromules exchange signals or metabolites between plastids and other subcellular compartments, and that stromules are induced during stress. Until now, no signaling mechanisms originating within the plastid have been identified that regulate stromule activity, a critical missing link in this hypothesis. Using confocal and superresolution 3D microscopy, we have shown that stromules form in response to light-sensitive redox signals within the chloroplast. Stromule frequency increased during the day or after treatment with chemicals that produce reactive oxygen species specifically in the chloroplast. Silencing expression of the chloroplast NADPH-dependent thioredoxin reductase, a central hub in chloroplast redox signaling pathways, increased chloroplast stromule frequency, whereas silencing expression of nuclear genes related to plastid genome expression and tetrapyrrole biosynthesis had no impact on stromules. Leucoplasts, which are not photosynthetic, also made more stromules in the daytime. Leucoplasts did not respond to the same redox signaling pathway but instead increased stromule formation when exposed to sucrose, a major product of photosynthesis, although sucrose has no impact on chloroplast stromule frequency. Thus, different types of plastids make stromules in response to distinct signals. Finally, isolated chloroplasts could make stromules independently after extraction from the cytoplasm, suggesting that chloroplast-associated factors are sufficient to generate stromules. These discoveries demonstrate that chloroplasts are remarkably autonomous organelles that alter their stromule frequency in reaction to internal signal transduction pathways.

Biochar is increasingly been used as a soil amendment to improve water-holding capacity, reduce nutrient leaching, increase soil pH, and also as a means to reduce contamination through sorption of heavy metals or organic pollutants. The sorption behavior of three phenylurea herbicides (monuron, diuron and linuron) on five biochars (Enhanced Biochar, Hog Waste, Turkey Litter, Walnut Shell and Wood Feedstock) and an agricultural soil (Yolo silt loam) was investigated using a batch equilibration method. Sorption isotherms of herbicides to biochars were well described by the Freundlich model (R(2) = 0.93-0.97). The adsorption KF values ranged from 6.94 to 1306.95 mg kg(-1) and indicated the sorption of herbicides in the biochars and Yolo soil was in the sequence of linuron > diuron > monuron and walnut shell biochar > wood feedstock biochar > turkey litter biochar > enhanced biochar > hog waste biochar > Yolo soil. These data show that sorption of herbicides to biochar can have both positive (reduced off-site transport) and negative (reduced herbicide efficacy) implications and specific biochar properties, such as H/C ratio and surface area, should be considered together with soil type, agriculture chemical and climate condition in biochar application to agricultural soil to optimize the system for both agricultural and environmental benefits.

Herbicides have contributed to increased agricultural production. However, their residual amount can cause negative effects on environmental and public health. Therefore, this work aimed to determine the occurrence of both atrazine and diuron in surface and well water and investigate their link with drinking use. The samples were collected during dry and rainy seasons in three wells and surface water from a river and a pond located in the low plains of the Ixcatepec catchment, at the Amacuáhuitl community of the municipality of Arcelia, Guerrero State, in the center south of México, which is a rural community where farming is the main activity. The compounds were obtained by solid phase extraction and determined by HPLC-MS quadrupole with positive electrospray ionization mode. A geomorphic analysis was conducted inside the Ixcatepec catchment using the digital elevation model of the Shuttle Radar Topography Mission, SRTM-v4. The human risk for drinking water was calculated according to the Hazard Quotient. The concentrations of atrazine and diuron were between 5.77 and 402 ng L−1. Atrazine was the most abundant and frequent pesticide found with an average concentration of 105.18 ng L−1, while that of diuron was 86.56 ng L−1. The highest levels were found in pond Ushe, likely being the result of the lowest flow and stagnation of water, and during the cold-dry season a consequence of mobilization by irrigation runoff. The morphological analysis indicated that the compounds mainly reached body water located in the lower surfaces from cultivated areas. Therefore, the occurrence is mainly linked to agriculture activity within the rural community. However, chemical properties of compounds, crop irrigation, and environmental conditions could be contributing to the dispersion of residual amounts of herbicides within the hydrological system. The estimation of risk showed that atrazine can mainly generate health problems for children using the Azul well as a source of drinking water.

Diuron is an herbicide used for weed control in agricultural crops that can cause a range of complications in humans from skin irritation to cancer. In this study, heterogeneous photocatalysis were performed using TiO2 and ZnO as catalysts in a batch reactor for Diuron degradation. Experimental designs were carried out in order to assess the influence of pH, catalyst and substrate concentration, in addition to optimizing the Diuron degradation. After 3 h of reaction, the pH showed to be the most important variable on the Diuron degradation using TiO2 as a catalyst. The use of ZnO led to a conversion rate higher than 98% in all tests performed. ZnO showed higher efficiency than TiO2, was attributed to the adsorption step. The mechanistic study suggested different reaction routes compared to the catalysts employed, with the participation of holes and photo-generated electrons in ZnO, whereas in TiO2 only the conduction band was relevant in the process.

Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.

Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter , Bacillus , Vagococcus , Burkholderia , Micrococcus , Stenotrophomonas , and Pseudomonas and fungal genera Aspergillus , Pycnoporus , Pluteus , Trametes , Neurospora , Cunninghamella , and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR. [ABSTRACT FROM AUTHOR]

The D1:Val219 residue of Photosystem II in the cyanobacterium Synechocystis sp. PCC 6803 was mutated to alanine or isoleucine, creating the V219A and V219I mutants, respectively. Oxygen evolution was slowed in these mutants, while chlorophyll a fluorescence induction assays indicated slowed electron transfer. As previously observed [Erickson J.M., Rahire, M., Rochaix, J.‐D. and Mets. L. (1985) Science, 228, 204–207], the V219I mutant was resistant to 3,4‐dichloro‐1,1‐dimethyl urea (DCMU); however, the V219A strain displayed no DCMU resistance. Additionally, the V219A strain was less sensitive to the addition of formate than the control, while the V219I strain was more sensitive to formate. Both mutant strains were susceptible to photodamage and required protein synthesis for recovery. We hypothesize that the sensitivity to DCMU and the extent of bicarbonate‐reversible formate‐induced inhibition, as well as the capacity for recovery in cells following photodamage, are influenced by the hydrophobicity of the environment associated with the Val219 residue in D1. [ABSTRACT FROM AUTHOR]

The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing. [ABSTRACT FROM AUTHOR]

Biocides used in film protection products leaching from facades are known to be a potential threat to the environment. This study identifies individual sources and entry pathways in a small-scale urban area. We investigate emissions of commonly used biocides (terbutryn, diuron, and octylisothiazolinone – OIT) and some of their transformation products (TPs; diuron-desmethyl, terbumeton, terbuthylazine-2-hydroxy, and terbutryn-desethyl) from a 2 ha residential area 13 years after construction has ended. Sampling utilizes existing urban water infrastructure representative for decentralized storm water management in central and northern Europe and applies a two-step approach to (a) determine the occurrence of biocides above water quality limits (i.e., predicted no-effect concentration, PNEC) and (b) identify source areas and characterize entry pathways into surface and groundwater. Monitoring focuses on the analysis of selected biocides and TPs by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) in water samples taken from facades, rainwater pipes, drainage, and storm water infiltration systems. In standing water in a swale, we found high concentrations of diuron (174 ng L -1) and terbutryn (40 ng L -1) above PNEC for surface water. We confirmed expected sources, i.e., facades. Sampling of rain downpipes from flat roofs identified additional sources of all biocides and two TPs of terbutryn and one TP of diuron. Diuron and terbutryn were found in three drainage pipes representing different entry pathways of biocides. In one drainage pipe collecting road runoff, only diuron-desmethyl and terbutryn-desethyl were detected. In two other drainage pipes collecting infiltrated water through soil, terbuthylazine-2-hydroxy was additionally detected. One of the pipes collecting infiltrated water through soil concentration showed the highest concentrations of terbutryn and two of its TPs (terbutryn-desethyl and terbuthylazine-2-hydroxy). This suggests a high leaching potential of terbutryn. The applied two-step approach determined sources and pathways of biocide and their TPs. This study contributes to expanding knowledge on their entry and distribution and, thus, eventually towards reducing emissions. [ABSTRACT FROM AUTHOR]

This study systematically investigated the oxidative treatment of five selected pesticides, alachlor (ALA), carbendazim (CAR), diuron (DIU), pyrimethanil (PYR), and tebuconazole (TEB), by comparing their relative reactivities as a function of three different oxidative treatment processes (i.e., chlorine (HOCl), ozone (O3), and ozone/hydrogen peroxide (O3/H2O2)) under various oxidant dosages, reaction times, and pH conditions. For oxidative treatment, pesticide standards were spiked into rainwater. The removal efficiency of the selected pesticides varied considerably depending on the oxidative treatment processes. HOCl, O3, and O3/H2O2 treatments were highly effective at eliminating CAR (>80%) and PYR (>99%), while they were not significantly effective in removing TEB (<20%). In the case of DIU, HOCl (81%) was shown to be more effective than O3 (24%) and O3/H2O2 (49%). The removal efficiency of ALA was in the order of O3/H2O2 (49%) > O3 (20%) > HOCl (8.5%). The effect of increasing the solution pH from 5.0 to 9.0 on pesticide degradation varied between the oxidative treatment processes. Additionally, NH4+, NO2−, and humic acid in rainwater significantly inhibited pesticide degradation. [ABSTRACT FROM AUTHOR]

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Herbicides are the most widely used class of pesticides in the world. Their intensive use raises the question of their harmfulness to the environment and human health. These pollutants need to be detected at low concentrations, especially in water samples. Commonly accepted analytical techniques (HPLC-MS, GC-MS, ELISA tests) are available, but these highly sensitive and time-consuming techniques suffer from high cost and from the need for bulky equipment, user training and sample pre-treatment. Biosensors can be used as complementary early-warning systems that are less sensitive and less selective. On the other hand, they are rapid, inexpensive, easy-to-handle and allow direct detection of the sample, on-site, without any further step other than dilution. This review focuses on enzyme- and cell- (or subcellular elements) based biosensors. Different enzymes (such as tyrosinase or peroxidase) whose activity is inhibited by herbicides are presented. Photosynthetic cells such as algae or cyanobacteria are also reported, as well as subcellular elements (thylakoids, chloroplasts). Atrazine, diuron, 2,4-D and glyphosate appear as the most frequently detected herbicides, using amperometry or optical transduction (mainly based on chlorophyll fluorescence). The recent new WSSA/HRAC classification of herbicides is also included in the review. [Display omitted] [ABSTRACT FROM AUTHOR]

Physcomitrella patens is a model bryophyte representing an early land plant in the green plant lineage. This organism possesses many advantages as a model organism. Its genome has been sequenced, its predominant life cycle stage is the haploid gametophyte, it is readily transformable and it can integrate transformed DNA into its genome by homologous recombination. One limitation for the use of P. patens in photosynthesis research is its reported inability to grow photoheterotrophically, in the presence of sucrose and the Photosystem II inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, which prevents linear photosynthetic electron transport. In this communication we describe the facile isolation of a P. patens strain which can grow photoheterotrophically. Additionally, we have examined a number of photosynthetic parameters for this strain grown under photoautotrophic, mixotrophic (in the presence of sucrose) and photoheterotrophic conditions, as well as the 3-(3,4-dichlorophenyl)-1,1-dimethylurea-inhibited state. The ability to grow P. patens photoheterotrophically should significantly facilitate its use in photosynthetic studies.

There was a lack of information regarding the use of herbicides in pineapple crop, so the aim was to evaluate the growth and initial development of 'Smooth Cayenne' and 'Pérola' pineapple seedlings under application of diuron, sulfentrazone and ametryn, isolated and associated, in post-planting. The experiments were conducted in a greenhouse and the treatments consisted of application of herbicides after planting. Crop injury, leaf length and dry leaf mass and total aerial part were evaluated. The initial growth and development of the 'Smooth Cayenne' pineapple seedlings were not negatively influenced by the application of diuron. The initial growth and development of pineapple seedlings 'Pérola' was not negatively influenced by the application of diuron and ametryn, isolated or associated with each other.

O objetivo deste trabalho foi verificar a influência da concentração do diuron no processo de clarificação da água por meio da tecnologia por ciclo completo e, por meio de um balanço de massa, avaliar a remoção de carbono orgânico total (COT). Foram preparadas águas de estudo com características similares às do rio Pardo. Verificou-se que para diferentes concentrações de diuron não ocorreram alterações no processo de clarificação da água e na sedimentabilidade dos flocos. Observou-se que a tecnologia de tratamento de água em ciclo completo apresentou remoção do herbicida diuron entre 18,60% e 26,21%. Tal fato confirma a ineficiência da tecnologia para a remoção de diuron. Para a ausência de diuron na água de estudo, a remoção foi de até 53,23% de COT. Ao adicionar o herbicida nas diferentes concentrações analisadas, a remoção de COT foi reduzida significativamente, obtendo-se percentuais de remoção com variação de 8,72% a 18,34%.

Background: The European Water Framework Directive (WFD) has been implemented to achieve a good ecological status in European water bodies requiring macrophyte community assessment as one of the biological quality elements (BQEs). While in several lakes in Schleswig-Holstein (Germany) different BQEs improved within recent years, no recovery of macrophyte communities in some lakes could be achieved, despite the reduction of nutrient input and eutrophication. Due to the fact that no impairment of phytoplankton could be observed, toxic stress due to sediment contamination was hypothesized as a possible limiting factor of macrophyte community recovery. Results: Sediment toxicity was investigated by performing an extensive chemical screening of sediment contamination and a risk assessment based on toxic unit (TU) summation, using equilibrium water concentrations and algal toxicity as surrogates for lacking data on macrophyte toxicity. Possible indirect risks via toxic pressure on grazer were assessed via TUs based on crustaceans. The study revealed algal TUs of more than one order of magnitude below chronic toxicity thresholds in lakes with high and good status of the macrophyte community and increasing concentrations and frequency of exceedance of toxicity thresholds for lakes with moderate-to-bad status. The antifouling biocides irgarol and diuron were identified as major risk drivers. In addition, PAHs and glyphosate could not be ruled out to contribute to toxic pressure on macrophytes. Despite exceedance of toxicity thresholds for crustaceans, no connection of the ecological status of the macrophyte communities with toxic risks to grazers could be observed. Conclusions: Our study suggests that in a multiple pressure situation the toxic pressure created due to the contamination of sediments with antifouling biocides is one of the limiting factors for the recovery of macrophyte communities in impaired lakes of Schleswig-Holstein. This finding is in agreement with a Europe-wide survey on almost 47,000 sites suggesting that no good ecological status can be observed at sites with contamination exceeding toxicity thresholds. Similar to the survey, our study indicates additional stressors preventing the achievement of a good quality status of the lake ecosystems. [ABSTRACT FROM AUTHOR]