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.

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.

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.

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.

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.

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.

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.

Potential impacts of seasonal variation on atrazine and metolachlor persistence in andisol soil.

To estimate the potential effect of seasonal variation on the fate of herbicides in andisol soil, atrazine and metolachlor residues were investigated through the summer and winter seasons during 2013 and 2014 under field condition. The computed half-lives of atrazine and metolachlor in soil changed significantly through the two seasons of the trial. The half-lives were shorter in summer season with 16.0 and 23.5 days for atrazine and metolachlor, respectively. In contrast, the half-lives were longer during the winter season with 32.7 and 51.8 days for atrazine and metolachlor, respectively. The analysis of soil water balance suggested that more pesticide was lost in deeper soil layers through infiltration in summer than in winter. In addition, during the summer season, metolachlor was more likely to leach into deeper soil layer than atrazine possibly due to high water solubility of metolachlor.

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.

Determination of etoxazole residues in fruits and vegetables by SPE clean-up and HPLC-DAD.

A method for determination of etoxazole residues in apples, strawberries and green beans was developed and validated. The analyte was extracted with acetonitrile from foodstuff and a charcoal-celite cartridge was used for clean-up of raw extracts. Reversed phase high performance liquid chromatography with photodiode array detector (HPLC-DAD) was used for the determination and quantification of etoxazole residues in the studied samples. The calibration graphs of etoxazole in a solvent or three blank matrixes were linear within the tested intervals 0.01-2 mg L(-1), with correlation coefficient of determination >0.999. The combined solid phase extraction (SPE) clean-up and the chromatographic method steps were sensitive and reliable for simultaneous determination of etoxazole residues in the studied samples. The average recoveries of etoxazole in the tested foodstuffs were between 93.4 to 102% at spiking levels of 0.01, 0.10, and 0.50 mg kg(-1), with relative standard deviations ranging from 2.8 to 4.7%, in agreement with directives for method validation in residue analyses. The limit of detection (LOD) of the HPLC-DAD system was 100 pg. The limit of quantification of the entire method was 0.01 mg kg(-1).

Simultaneous determination of spinetoram residues in tomato by high performance liquid chromatography combined with QuEChERS method.

A sensitive and simple method for simultaneous analysis of spinetoram residues and its dissipation in tomato were studied. Spinetoram residues were extracted from tomato samples with acetonitrile. The extract was cleaned-up with QuEChERS method by dispersive solid-phase extraction with primary secondary amine sorbent to remove co-extractives, prior to analysis by high performance liquid chromatography coupled with diode array detector (HPLC-DAD). This method is characterized by recovery >97 %, relative standard division (RSD) <12.3 %, and limit of quantification (LOQ) of 0.04 mg kg(-1), in agreement with directive for method validation in residue analysis. Also, the results showed that spinetoram dissipation pattern followed the first order kinetics with the half-life of 2.6 days, in tomato. The spinetoram residues in tomato were below the codex maximum residue level (0.06 mg kg(-1)) after 10 days of application. This study suggests that spinetoram is acceptable to apply for tomato under the recommended dosage.

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.

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.

Metals in water from the River Nile tributaries in Egypt.

The objective of this study was to evaluate the levels of Zn, Cu, Pb, Fe and Cd metals in water samples collected from different tributaries of the Nile River in Egypt. Samples were taken from El-Sarsawia, El-Bagoria, Bahr Shebin canals, in addition to three drainage canal sites El-Embaby, El-Menofi and Miet-Rabiha drain. According to the data, Fe has the highest concentration, followed by Pb, Zn, Cd and Cu. The mean Pb concentration ranged from 8.678 to 21.948 µg/L, in water samples collected from El-Sarsawia canal and El-Embaby drain, respectively. The Cu and Cd mean concentrations ranged from 0.67 and 0.500 to 4.908 and 5.650 µg/L, respectively, in water samples collected from Bahr-Shebin canal and El-Embaby drain, respectively. The water samples from all location sites are polluted by Pb according to EPA. Fe and Cu values are within the allowable limits.

Dissipation of chlorantraniliprole in tomato fruits and soil.

The main objective of this study was to understand the residue and persistence behaviour of new insecticide chlorantraniliprole in tomato fruit and soil samples. Its residue was analyzed by HPLC and it dissipated in tomato fruit and soil following first order kinetics. The results showed half life (t(1/2)) value of 3.30 and 3.66 days for chlorantraniliprole in tomato fruit and soil, respectively. According to maximum residue limit (MRL) the pre-harvest interval (PHI) of chlorantraniliprole on tomato was 8-days after the treatment.

Contamination of cows milk by heavy metal in Egypt.

The present investigation was carried out to assess the residues levels of five metals (Cadmium, Copper, Lead, Iron and Zinc) in cow milk collected from different sites in El-Qaliubiya governorate, Egypt. A total of 100 cow milk samples were collected from twenty cows in each location sites during the morning milking in the period from March to April, 2011. The highest average concentration are those of iron (16.38 µg/g) followed by zinc (10.75 µg/g) and lead (4.404 µg/g), while the lowest mean concentration are 2.836 and 0.288 µg/g for copper and cadmium, respectively. The results showed that most of the milk samples from the different sites containing all the studied metals with concentration higher than those recommended for milk by international dairy federation standard and Codex.

Estimation of etofenprox residues in tomato fruits by QuEChERS methodology and HPLC-DAD.

Etofenprox residues were estimated by employing standardized QuEChERS technique in tomato following one application of Trebon(®) 20 % EC. The average recoveries of etofenprox on tomato for fortification levels 0.01, 0.1 and 0.5 mg/kg were observed to be 87.5 %, 89.7 % and 92.2 %, respectively, with relative standard division of 3.50, 4.11 and 3.20. The LOQ for tomato was found to be 0.01 mg/kg. The average initial deposit of etofenprox on tomato was observed to be 0.783 mg/kg, at single application rate. This etofenprox residue dissipated below its LOQ of 0.01 after 15 days at a single dosage. Half-life of etofenprox was observed to be 2.15 days, at the recommended dosage. These data could provide guidance for the proper and safe use of this pesticide on tomato in Egypt.

Residue and dissipation dynamics of lufenuron in tomato fruit using QuEChERS methodology.

One field experiment was conducted with lufenuron (Match(®) 5% EC) on tomato crop during August 2011. The main objective was to understand the residue and dissipation behavior of insecticide lufenuron in tomato fruit samples. The dissipation behavior of lufenuron insecticide followed first-order rate kinetics at standard recommended dose application. The average initial deposit of lufenuron in tomato was observed to be 1.299 mg kg(-1)at single application rate. This lufenuron residue dissipated to bellow LOQ of 0.03 mg kg(-1) 21 days after the treatment. Lufenuron residues were lost with pre-harvest intervals of 7 days, following application at the recommended dose by manufacture.