Dissipation behavior, residue distribution, and exposure risk assessment of tebufenpyrad and milbemectin acaricides in strawberries under open field conditions.

Strawberries are a favorite fruit for most people, but the residues of pesticides on strawberries might be risky to human health. Tebufenpyrad and milbemectin are broad-spectrum acaricides with insecticide properties authorized for use on strawberries in Egypt. As a result, it is crucial to investigate their residues in the final product to ensure customers' safety. Consequently, field trials were conducted following the Good Agricultural Practices (GAPs) to study the dissipation rate and terminal residues of tebufenpyrad and milbemectin on strawberries. Tebufenpyrad and milbemectin residues in strawberries declined due to first-order decay process, showing significant degradation (88.5% and 94.7%, respectively) after 14 days. Risk assessment study was carried out by comparing the national estimated daily intake (NEDI) to the acceptable daily intake (ADI). The results demonstrated that the dietary risk posed by the residues of tebufenpyrad and milbemectin in strawberry fruits was acceptable for consumers. It is envisaged that the current study's findings would support the safe application of tebufenpyrad and milbemectin to strawberries and perhaps other crops in Egypt and other countries with similar climatic conditions.

Macro, Micro, and Nano-Inspired Bioactive Polymeric Biomaterials in Therapeutic, and Regenerative Orofacial Applications.

Introducing dental polymers has accelerated biotechnological research, advancing tissue engineering, biomaterials development, and drug delivery. Polymers have been utilized effectively in dentistry to build dentures and orthodontic equipment and are key components in the composition of numerous restorative materials. Furthermore, dental polymers have the potential to be employed for medication administration and tissue regeneration. To analyze the influence of polymer-based investigations on practical medical trials, it is required to evaluate the research undertaken in this sector. The present review aims to gather evidence on polymer applications in dental, oral, and maxillofacial reconstruction.

Dissipation kinetics and exposure of spirotetramat and pymetrozine in open fields, a prelude to risk assessment of green bean consumption.

Determination and dissipation kinetics of pymetrozine and spirotetramat in green bean were studied using a QuEChERS method coupled to high-performance liquid chromatography-tandem mass spectrometry. Pymetrozine recoveries ranged between 88.4-93.7%, with relative standard deviation (RSD) of 5.5-14.4%. For spirotetramat the recoveries ranged between 91.7-103.4%, and the RSD were in the range of 3.2 to 12.4%. The limits of quantification (LOQs) were 0.01 mg/kg and 0.005 mg/kg for pymetrozine and spirotetramat, respectively.The developed analytical method was used to study the degradation rates of pymetrozine and spirotetramat in green bean grown in open field. Results showed that pymetrozine and spirotetramat followed the first-order kinetics model with half-lives of 3.3 days and 4.2 days, respectively. Furthermore, risk assessment was carried out which showed that, the chronic risk quotient (RQc) values for pymetrozine and spirotetramat were much lower than 100%. The present results indicated that the health risks posed for consumers by the pymetrozine and spirotetramat residues were negligible at the recommended dosages.

The Effect of Neonicotinoids Exposure on Oreochromis niloticus Histopathological Alterations and Genotoxicity.

This study aimed to examine the side effects of selected neonicotinoids (Acetamiprid, Aceta, and Imidacloprid, Imid) on Oreochromis niloticus juveniles. The acute toxicity, Probit method, revealed an LC50 of 195.81 and 150.76 ppm for Aceta/96 h and Imid/72 h respectively. The fish were divided into three groups that were exposed, for 21 days (n = 5/replicate), to 1/10 of the LC50 of either neonicotinoids, however, the third was an unexposed control group. Results of erythrocytic micronucleus (MN), and nuclear abnormalities (NA) showed that Aceta and Imid exposure caused a significant (p < 0.05) increase in MN by ~ 2.2 and ~ 10 folds, respectively relative to control. NAs occurred at the order of kidney-shaped > budding > binucleated in Aceta, however, budding > binucleated > kidney-shaped was noticed in the Imid group. Histopathological changes in gills, liver, and muscles were observed significantly in both exposed groups with more severity in the Imid group. Collectively, Aceta and Imid have potential genotoxicity and histopathological alterations in O. niloticus.

Residue, dissipation, and dietary intake evaluation of fenpyroximate acaricide in/on guava, orange, and eggplant under open field condition.

Fenpyroximate is a widely used acaricide applicable in many crops. In this study, the residue behavior of fenpyroximate on eggplant, orange, and guava was investigated. The chronic and acute dietary intake was calculated at several sampling points, and preharvest intervals (PHI) were proposed to ensure compliance with the existing maximum residue levels. A simple extraction protocol combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was employed to quantify residue levels. The method was successfully validated according to the European Union (EU) guidelines, and a limit of quantification of 0.01 mg/kg was set. The dissipation patterns in all crops could be described by the first-order kinetics model with half-lives of 1.7, 2.2, and 1.9 days for eggplants, guavas, and oranges, respectively. The dietary risk assessment at the authorized or more critical application patterns was acceptable for the consumers. For oranges and eggplant, a PHI of 3 and 7 days, respectively, can be proposed; however, a proposal was not possible for guava due to the absence of maximum residue limits (MRLs) and quantitative residue findings at all sampling points tested. The current work not only contributes to the practical application of fenpyroximate related to residue management in dryland areas, such as Egypt, but can also be used to estimate the appropriate PHIs and support the authorization of plant protection products as supplementary information.

Full-length transcriptome analysis of Spodoptera frugiperda larval brain reveals detoxification genes.

BACKGROUND: Spodoptera frugiperda (J. E. Smith), commonly known as fall armyworm (FAW), is one of the most destructive agricultural pests in the world and has posed a great threat to crops. The improper use of insecticides has led to rapid development of resistance. However, the genetic data available for uncovering the insecticide resistance mechanisms are scarce. METHODS: In this study, we used PacBio single-molecule real-time (SMRT) sequencing aimed at revealing the full-length transcriptome profiling of the FAW larval brain to obtain detoxification genes. RESULTS: A total of 18,642 high-quality transcripts were obtained with an average length of 2,371 bp, and 11,230 of which were successfully annotated in six public databases. Among these, 5,692 alternative splicing events were identified.

Investigation of the dissipation behaviour and exposure of spitotetramat, flonicamid, imidacloprid and pymetrozine in open field strawberries in Egypt.

The dissipation behaviour and the consumer risk assessment of spitotetramat, flonicamid, imidacloprid and pymetrozine in open field strawberries were studied. Insecticides were applied at the authorised levels and the more critical good agricultural practice regimes (GAP). The initial concentrations varied from 0.069 to 1.75 mg kg-1 depending on the compound, while the dissipation half-lives and terminal residues, 14 days from the last applications, were similar. After application according to the authorised pattern the half-lives were 2.8 days for flonicamid and 3.2 days for spitotetramat, imidacloprid and pymetrozine. The dietary risk assessment, performed using the hazard quotient and the EFSA PRIMo model showed no concern to consumer health with exposure values <2% of the acceptable daily intake (ADI) and <32% of the acute reference dose (ARfD) of each compound.

Dissipation behavior and dietary risk assessment of pyridaben in open field strawberries and cucumber under Egyptian cultivation conditions.

Pyridaben, an inhibitor of mitochondrial electron transport at complex I, is authorized in Egypt as an insecticide/acaricide for strawberries and cucumbers; thus the investigation of residues in the final consumed product is essential as to ensure consumer safety and trade barriers. Therefore, residue trials were conducted according to the in force and more critical Good Agricultural Practices (GAPs) as to investigate the dissipation rate of the compound on both crops and the terminal residues in the final products. Results showed that the residue decline fits a first-order decay process with calculated half-lives of 1 and 6.4 days for cucumbers and strawberries, respectively. Dietary risk assessment was performed based on the risk quotients (RQ) method and the EFSA PRIMo model demonstrating that the dietary exposure to pyridaben residues from cucumber and strawberry consumption, applied either according to the in force or more critical GAPs, does not pose unacceptable health risk to Egyptian and European consumers.

A Preliminary Toxicology Study on Eco-friendly Control Target of Spodoptera frugiperda.

Pyrethroid and indoxacarb are commonly used pesticides to control the fall armyworm (Spodoptera frugiperda) in the crops. There are a series of consequences caused by the use of pyrethroid and indoxacarb pesticides under emergency control, such as pest resistance development, contamination of soil, water, and farm products. This study analyzed the structure and physiological function of the sodium channel in S. frugiperda, which is an important step to elaborate the resistance mechanism of S. frugiperda to indoxacarb and pyrethroid pesticides. According to genetic analysis, the cloned cDNA sequences of sodium channel in S. frugiperda (SfNav) showed the shortest genetic distance with that of the sodium channel in Helicoverpa armigera. Under the induction of three pesticides, the expression of SfNav decreased in the first 12 h and then increased after 24 h. It was concluded that SfNav had a typical structure of the sodium channel of insects and its down-regulated expression can decrease the combination of S. frugiperda with pyrethroid and indoxacarb pesticides. The up-regulated expression of SfNav was conducive to the enhancement of the pesticide resistance.

Dissipation behavior of thiophanate-methyl in strawberry under open field condition in Egypt and consumer risk assessment.

Thiophanate methyl is a broad-spectrum benzimidazole fungicide extensively applied in pre- and post-harvest, for the control of a wide range of fruit and vegetable pathogens. In the current work, the residue behavior of thiophanate methyl after application on strawberries and an estimation of the consumer dietary exposure was performed. Supervised field trials were conducted in Egypt (Qaluobiya Governorate) as to investigate the residue dynamics and terminal residues at different PHIs of thiophanate methyl and its metabolite carbendazim in strawberries under Egyptian conditions. For the measurement of residues in fruits, a QuEChERS-based protocol coupled with LC-MS/MS was optimized and successfully validated at 0.01 mg kg-1. The half-life (t1/2) of thiophanate methyl in strawberries was estimated, and a dietary risk assessment was performed employing both FAO/WHO and EFSA approaches.

Residue behavior of etoxazole under field conditions in Egypt and estimation of processing factors during the production of strawberry juice and purée.

The degradation under field conditions and the residue behavior of etoxazole during juicing and purée making was evaluated. Etoxazole residues were determined by HPLC-UV at six different Pre Harvest Intervals (PHIs) as to estimate the degradation of residue in fruits. Samples with significant residues were processed and residue were determined after juicing and purée making. The effect of washing was also estimated. Processing Factors (PFs) for etoxazole after each step were less than 1 and the PFs of the overall processes were lower than 0.85 for washing fruits, 0.13 for juice and 0.04 for purée. The studied processes could obviously reduce the pesticide residues that are present in the raw strawberries. Uncertainties in the use of the PFs were identified due to the potential formation of metabolites during the processes.

Magnitude of picoxystrobin residues in strawberry under Egyptian conditions: dissipation pattern and consumer risk assessment.

Picoxystrobin is a synthetic strobilurin fungicide widely used in Egypt to control downy and powdery mildews, a risk that is significant also in cultivating strawberries. In the ccurrent work, the safety to consumers from the use of picoxystrobin in strawberries along with its residue behaviour was studied. Supervised field trials were conducted to investigate the residue dynamics and terminal residues of picoxystrobin in strawberries under Egyptian conditions for several agricultural practices including worst-case scenarios. For the measurement of residues in fruit, a QuEChERS-based protocol coupled with LC-MS/MS was employed and successfully validated at 0.001 mg kg-1. A decline of picoxystrobin residues in fruit fitted a first-order decay process with a calculated t1/2 of 5.4 days with a significant degradation (79%) after 14 days. A consumer risk assessment was performed employing both FAO/WHO and EFSA approaches, in which no significant health risks after consumption of strawberries were identified.

Residues, dissipation and risk evaluation of spiroxamine in open-field-grown strawberries using liquid chromatography tandem mass spectrometry.

The dissipation dynamic and residues of spiroxamine in open-field-grown strawberries were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spiroxamine application was performed according to Egyptian good agricultural practices recommendation. A QuEChERS-based extraction method along with direct analysis with an LC-MS/MS analytical method were optimized and validated, and the specificity of the techniques used was considered satisfactory. Good linearity (R2 > 0.999) was obtained for spiroxamine within the range of 0.001-0.1 µg/ml. The mean recoveries varied between 97.1 and 108.2%, with inter- and intra-day precision (RSD) <4.9%. The limit of quantitation for spiroxamine was 0.001 mg/kg. The results indicated that spiroxamine degradation in strawberry followed first-order kinetics (R2 > 0.9929) with an estimated half-life value of 4.71 days. Considering the Australian maximum residue limit (0.05 mg/kg) in strawberry and based on the results from residue trials with a preharvest interval of 14 days for strawberry, compliance can be expected. The present results could provide guidance to fully evaluate the risks of spiroxamine residues, preventing any potential health risk to consumers.

Thermal stress accelerates mercury chloride toxicity in Oreochromis niloticus via up-regulation of mercury bioaccumulation and HSP70 mRNA expression.

Mercury (Hg) is an environmental pollutant that threatens aquatic life. Many environmental factors, including water temperature, are reported to influence the toxicity of dissolved chemicals in the aquatic ecosystem. Therefore, we investigated the impact of thermal stress on Hg-induced subchronic toxicity in Nile tilapia (Oreochromis niloticus). Fish were randomly allocated into five groups. Group I served as the control and kept at 25 °C. Groups II, III, IV, and V were reared at 25, 28, 31, and 34 °C, respectively, and co-exposed to HgCl2 (1/10 LC50) for 42 days. Blood and tissue samples were collected after 21 and 42 days. All HgCl2-exposed groups exhibited significant elevations in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, and creatinine, along with decreases in the serum total protein and albumin. In addition, marked reductions in antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSPx), were observed. Remarkable increases in Hg tissue concentrations were detected along with increases in heat shock protein (HSP) 70 mRNA expression. Interestingly, the patterns data that were recorded were more coincident with the water temperature than the period of exposure. In conclusion, water temperature and exposure period are two crucial factors modulating HgCl2-induced toxicity and bioaccumulation in Nile tilapia. Our findings provide new insights concerning the impact of thermal stress as an environmental factor on Hg toxicity and bioaccumulation in Nile tilapia and, in turn, on fish and fish consumer health.

Residue distribution and risk assessment of two macrocyclic lactone insecticides in green onion using micro-liquid-liquid extraction (MLLE) technique coupled with liquid chromatography tandem mass spectrometry.

A micro-liquid-liquid extraction (MLLE) technique coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis was established and validated to determine the residues of two macrocyclic lactone insecticides (spinetoram and spinosad) in green onion. The limit of quantification (LOQ) of the method, as demonstrated by the lowest acceptable recovery level, was 0.01 mg kg-1, and the obtained recoveries were 78.3-93.4% with relative standard deviations (RSDs) < 12.5%. The method was then applied for analyzing field samples collected after treatment with the tested insecticides under Egyptian open-field condition. The decline pattern, terminal residues, and dietary risk assessment of spinetoram and spinosad residues in green onion were evaluated for food safety. Spinetoram and spinosad residues' decline in green onion followed first-order kinetics with the half-lives of 1.2 and 1.42 days, respectively. Based on the results, the required period to reach their respective maximum residue limits (MRLs) was 1 and 0 days for spinetoram and spinosad residues in green onion, respectively, which indicates a short persistence level and high degradation rate. The results suggest that there is no unacceptable chronic or acute risk to human health from the consumption of green onion treated with spinetoram and spinosad according to the uses considered.

Consumer safety evaluation of pyraclostrobin residues in strawberry using liquid chromatography tandem mass spectrometry (LC-MS/MS): An Egyptian profile.

The dissipation rates of pyraclostrobin, a methoxyacrylate strobilurin group fungicide, along with its final residues and dietary exposure in strawberry were studied under Egyptian field conditions. Extraction was performed using a QuEChERS method, while residue determination was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) with limits of quantitation of 0.001 mgkg-1. At three different fortification levels (1.0, 10 and 100 ng/g) of pyraclostrobin applied to untreated strawberry samples, the recoveries ranged between 97 and 104% with relative standard deviation (RSD) of 1-6% (n = 6). The reported analytical method fulfills the standard requirements with regard to specificity, repeatability, limit of quantitation and recoveries. The half-life (t1/2) of pyraclostrobin after one single application of the recommended rate was 5 days. Risk assessment study was carried out by comparing the national estimated daily intake (NEDI) against acceptable daily intake (ADI) under good agricultural practice (GAP) conditions. Results indicated that strawberry treated with pyraclostrobin at the recommended dosage, are safe for human consumption three days after two successive applications with 14 days interval between each application. The present research should pave the way for the establishment of the safe and proper use of pyraclostrobin in strawberry in Egypt.

Buprofezin dissipation and safety assessment in open field cabbage and cauliflower using GC/ITMS employing an analyte protectant.

An analytical method for the determination of buprofezin residues in cabbage and cauliflower was developed and validated using gas chromatography with ion trap mass spectrometry. The analyte protectant d-sorbitol was used at a concentration level of 0.5 mg mL-1 in acetonitrile instead of in matrix for constructing the calibration curves of the buprofezin standard. The average recoveries ranged from 91.3 to 96.8%, with an RSD of ≤2.7%. The limits of detection and quantitation of the method in cabbage and cauliflower were 1.3, 1.7 and 4.3, 6.2 µg kg-1 , respectively. The residual levels and dissipation kinetics of buprofezin 25% wettabe powder in cabbage and cauliflower cultivated under open field conditions was investigated at the single (T1) and double (T2) recommended rates of application. Half-life periods were found to be 1.73 and 2.1 days in cabbage, whereas in cauliflower, these values were 1.85 and 2.36 days at T1 and T2, respectively. Based on the dissipation study, and the maximum residue limit value of 0.05 mg kg-1 , the proposed pre-harvest interval of buprofezin in cabbage was 3-6 days and that in cauliflower was 4-10 days. The results showed that buprofezin is safe for application at both recommended application rates.

Magnitude of cyantraniliprole residues in tomato following open field application: pre-harvest interval determination and risk assessment.

Cyantraniliprole is an anthranilic diamide insecticide, belonging to the ryanoid class, with a broad range of applications against several pests. In the presented work, a reliable analytical technique employing high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD) for analyzing cyantraniliprole residues in tomato was developed. The method was then applied to field-incurred tomato samples collected after applications under open field conditions. The latter aimed to ensure the safe application of cyantraniliprole to tomato and contribute the derived residue data to the risk assessment under field conditions. Sample preparation involved a single step extraction with acetonitrile and sodium chloride for partitioning. The extract was purified utilizing florisil as cleanup reagent. The developed method was further evaluated by comparing the analytical results with those obtained using the QuEChERS technique. The novel method outbalanced QuEChERS regarding matrix interferences in the analysis, while it met all guideline criteria. Hence, it showed excellent linearity over the assayed concentration and yielded satisfactory recovery rate in the range of 88.9 to 96.5%. The half-life of degradation of cyantraniliprole was determined at 2.6 days. Based on the Codex MRL, the pre-harvest interval (PHI) for cyantraniliprole on tomato was 3 days, after treatment at the recommended dose. To our knowledge, the present work provides the first record on PHI determination of cyantraniliprole in tomato under open field conditions in Egypt and the broad Mediterranean region.

PCPF-M model for simulating the fate and transport of pesticides and their metabolites in rice paddy field.

BACKGROUND: The PCPF-1 model was improved for forecasting the fate and transport of metabolites in addition to parent compounds in rice paddies. In the new PCPF-M model, metabolites are generated from the dissipation of pesticide applied in rice paddies through hydrolysis, photolysis and biological degradations. The methodology to parameterize the model was illustrated using two scenarios for which uncertainty and sensitivity analyses were also conducted. RESULTS: In a batch degradation experiment, the hourly forecasted concentrations of fipronil and its metabolites in paddy water were very accurate. In a field-scale experiment, the hourly forecasted concentrations of fipronil in paddy water and paddy soil were accurate while the corresponding daily forecasted concentrations of metabolites were adequate. The major contributors to the variation of the forecasted metabolite concentrations in paddy water and paddy soil were the formation fractions of the metabolites. The influence of uncertainty included in input parameters on the forecasted metabolite concentration was high during the peak concentration of metabolite in paddy water. In contrast, in paddy soil, the metabolite concentrations forecasted several days after the initial pesticide application were sensitive to the uncertainty incorporated in the input parameters. CONCLUSION: The PCPF-M model simultaneously forecasts the concentrations of a parent pesticide and up to three metabolites. The model was validated using fipronil and two of its metabolites in paddy water and paddy soil. The model can be used in the early stage of the pesticide registration process and in risk assessment analysis for the evaluation of pesticide exposure. © 2017 Society of Chemical Industry.