Poly (safranine) modified carbon paste electrode as a sensor for the determination of fenitrothion pesticide.

An effective electroanalytical method was developed for the quantitative evaluation of fenitrothion pesticide. The electrochemically modified carbon paste electrode CPE was constructed by applying a safranine layer on its surface. Safranine monomer is easily oxidized. So, a safranine layer was applied via electropolymerization using cyclic voltammetry in (2 × 10-5 M) safranine buffered solution with phosphate buffer BPS at pH.6, potential window (- 1.6: + 2 V), scan rate 100 mV/s. The morphology of the modified electrode was characterized using SEM images. The electropolymerization process was characterized by observing the gradual increases of the peak current with the subsequent scanning cycles. This modified CPE electrode showed an obvious sensitivity by cyclic voltammetry towards the cathodic peak of the fenitrothion nitro group at approximately - 0.73V with good sensitivity by enhancing it to be approximately 10 times more sensitive than on a bare carbon paste electrode CPE. The number of cycles was optimized for the electropolymerization process to be 12 cycles. Where, the peak current at - 0.73 V was gradually enhanced until 12 cycles when it is obviously decreased before slightly increasing again. The reproducibility of the modified electrode was ensured by repeating the sweep cycles using LSV for determining the fenitrothion at 5 µM where it was found that the peak current was unchanged for 10 sweeps before it starts to drop gradually. LSV voltammetry at previously optimized conditions of the potential window (- 0.4: - 1 V), sweep rate 100 mV/s, phosphate buffer at pH.6 was used for the quantitative studies. Where, the pHs of the determining medium were varied from pH 5.5 to pH 8 using phosphate buffer. It was observed that the most identified peak current was at pH.6 which is then decreased gradually until it completely disappeared at pH 8. The optimal accumulation time by adsorption of 140 s for the fenitrothion pesticide was confirmed in the range of (20 s-170 s). Where, the peak current was increased gradually with time up to 140 s then a plateau with a constant response was observed. The developed method showed an excellent linearity range of (1 µM:15 µM) with R2 parameter equal to 0.99906. LOD and LOQ were calculated to be 0.1 µM, and 0.34 µM respectively. Satisfactory levels have been reached for the calculated recovery, accuracy. Precision limits not exceed 1% for both repeatability and reproducibility measurements. F-value and t-value were measured for the suggested LSV method versus the standard HPLC method for the concentration of 8 µM fenitrothion and were found to be 1.482 and 0.123, respectively which didn't exceed the tabulated values. The ruggedness of the suggested method was examined toward deliberate safranine concentration variations in the concentration range of (0.01 mM-0.03 mM). Insignificant differences for the mean recovery at (98.33-98.93%) and precision at (1.39-2.6%) were observed. Hence, the reliability and validity of the developed LSV method were achieved and it was considered as rigid method.

Integrated multiomics analysis to infer COVID-19 biological insights.

Three years after the pandemic, we still have an imprecise comprehension of the pathogen landscape and we are left with an urgent need for early detection methods and effective therapy for severe COVID-19 patients. The implications of infection go beyond pulmonary damage since the virus hijacks the host's cellular machinery and consumes its resources. Here, we profiled the plasma proteome and metabolome of a cohort of 57 control and severe COVID-19 cases using high-resolution mass spectrometry. We analyzed their proteome and metabolome profiles with multiple depths and methodologies as conventional single omics analysis and other multi-omics integrative methods to obtain the most comprehensive method that portrays an in-depth molecular landscape of the disease. Our findings revealed that integrating the knowledge-based and statistical-based techniques (knowledge-statistical network) outperformed other methods not only on the pathway detection level but even on the number of features detected within pathways. The versatile usage of this approach could provide us with a better understanding of the molecular mechanisms behind any biological system and provide multi-dimensional therapeutic solutions by simultaneously targeting more than one pathogenic factor.

Influence of the cervical margin relocation on stress distribution - a finite element analysis on lower first molar restored by direct nano-ceramic composite

Aim: Evaluate the influence of the cervical margin relocation (CMR) on stress distribution in the lower first molar restored with direct nano-ceramic composite (zenit). Methods: A 3D model of the lower first molar was modeled and used. Standardized mesio-occluso-distal (MOD) preparation consisted in two models used in this study with mesial subgingival margin in model II. (CMR) was applied in model II using flowable composite or resin glass ionomer (Riva). Both models were restored with nanoceramic composite and then subjected to six runs (2 for the model I and 4 for model II) with load (100N) as two load cases, one at (11º) and other at (45º) from the vertical axis. The stress distributions (FEA) in the final restoration and (CMR) material were analyzed using 3D models. Results: The two models recorded an equivalent Von Mises stress and Total deformation in the final restoration, regardless of the difference in the oblique angle incidence from (11º to 45º) or the type of the material used for (CMR) there was no significant difference in the (FEA) between the model with CMR (model II) and the model without CMR (model I). Conclusions: (CMR) technique seems to be biomechanically beneficial with high eccentric applied stress, (CMR) with resin glass ionomer or flowable composite resin in combination with nanoceramic composite improved the biomechanical behavior of (MOD) cavities extended below cement enamel junction (CMR) with high modulus elasticity material like (Riva) exhibits a more uniform stress distribution

Diagnosing 'transition' to secondary progressive multiple sclerosis (SPMS): A step-by-step approach for clinicians.

Upon the approval of disease-modifying therapies (DMTs) for patients with active secondary progressive phase of multiple sclerosis (SPMS), there became an emerging need to prospectively predict and diagnose patients transitioning from the relapsing-remitting to the secondary progressive phase of MS. Whilst several research articles handle the challenges for diagnosing this stage of the disease, a clear step-by-step diagnostic approach remains elusive. This review aims at providing a step-by-step diagnostic approach to patients within 'transitioning' MS based on the currently available research findings and to summarize the gaps in the diagnostic approach and the recommendations for future research in this area of practice.

The role of serum gastric peptide ghrelin hormone level in irritable bowel syndrome at Zagazig University Hospitals.

Generalized dysmotility of the gastrointestinal tract develops in individuals with irritable bowel syndrome (IBS). The ghrelin hormone appears to be critical in controlling gastrointestinal motility. We aimed to evaluate serum ghrelin levels in people with IBS and to demonstrate its role in IBS pathophysiology. This study included 32 individuals with IBS (16 with constipation and 16 with diarrhea) and 16 healthy individuals as controls. Blood specimens were collected from patients and controls following an overnight fast. Total ghrelin level was detected in plasma by commercially available ELISA Kit. There were significant differences in the serum levels of ghrelin between the control group and both types of IBS. The mean±SD of ghrelin level in the control group was 2.608±0.714 pg/ml, and that of both types of IBS was 5.782±2.450 pg/ml (P-value<0.001). There was a significant variation between the control and IBS-D groups (mean±SD: 7.838±1.687 pg/ml, p-value<0.001). Also, we indicated a considerable difference between the control and IBS-C groups (mean±SD: 3.726±0.740 pg/ml, P-value<0.001). In comparing the IBS-D group and IBS-C group, we found a highly considerable variation between the two groups (p-value<0.001). This means that serum ghrelin levels were significantly greater in IBS-D than in IBS-C and the control group. Our findings concluded that serum ghrelin level was higher among the IBS-D group than in the IBS-C and control groups. The ghrelin hormone may play a vital role in IBS pathophysiology.

Mechanical and thermal stress analysis of hybrid ceramic and lithium disilicate based ceramic CAD-CAM inlays using 3-D finite element analysis / Análise do estresse mecânico e térmico de inlays de cerâmica hibrida e de cerâmica a base de dissilicato de lítio através da análise em 3D de elementos finitos

Objective: The aim of this study was to analyze mechanical and thermal stresses of hybrid ceramic and lithium disilicate based ceramic of CAD/CAM inlays using 3D Finite element analysis. Material and Methods:A three dimensions finite element model of permanent maxillary premolar designed according to standard anatomy with class II cavity preparation for inlay restored with two different ceramic materials: 1- Hybrid ceramic (Vita Enamic), 2- Lithium disilicate based ceramic (IPS e.max CAD). Totally six runs were performed on the model as: One loading case for each restorative material was tested in stress analysis; seven points of loading with 140N vertically applied at palatal cusp tip and cusp slop, marginal ridges and central fossa while the models base was fixed as a boundary condition in the two cases. Two thermal analysis cases were performed for each restoration material by applying 5ºC and 55ºC on the crown surface including the restoration surface. Results:The results of all structures were separated from the rest of the model to analyze the magnitude of stress in each component. For each group, maximum stresses on restorative materials, cement, enamel, and dentin were evaluated separately. Both ceramic materials generated similar stress distribution patterns for all groups when a total occlusal load of 140 N was applied. Conclusion: Thermal fluctuations of temperature have a great influence on the stresses induced on both restoration and tooth structure. IPS e.max CAD produced more favorable stresses on the tooth structure than Vita Enamic. (AU)

Objetivo: O objetivo deste estudo foi analisar o estresse mecânico e térmico de inlays de cerâmica hibrida e a base de dissilicato de lítio através da análise em 3D de elementos finitos. Material e Métodos: Foi realizado o design de um modelo de três dimensões em elementos finitos de um pré-molar superior de acordo com os padrões anatômicos de um preparo de cavidade classe II para restauração de inlay em dois tipos de cerâmicas diferentes: 1 Cerâmica hibrida (Vita Enamic), 2 ­ Cerâmica a base de dissilicato de lítio (IPS e.max CAD). No total, seis execuções foram realizadas no modelo como: Uma carga para cada material restaurador foi testado para análise de tensão; sete pontos de carga com 140N foi aplicado verticalmente na ponta da cúspide palatina, saliência da cúspide, cristas marginais e fossa central enquanto a base do modelo foi fixada como uma condição de limite nos dois casos. Duas análises térmicas foram realizadas para cada material de restauração, aplicando 5ºC e 55ºC na superfície da coroa, incluindo a superfície da restauração. Resultados: Os resultados de todas as estruturas foram separados do resto do modelo para analisar a magnitude do estresse de cada componente. Para cada grupo, o máximo de estresse nos materiais restauradores, cemento, esmalte e dentina foram avaliados separadamente. Padrões similares de distribuição de estresse foram gerados em todos os grupos para ambos os materiais cerâmicos, quando a carga oclusal de 140 N foi aplicada. Conclusão: As variações térmicas de temperatura têm uma grande influência nas tensões induzidas na restauração e na estrutura dentária. IPS e.max CAD produziu tensões mais favoráveis na estrutura dentária do que o Vita Enamic (AU)

Effect of chitosan nanoparticles on microtensile bond strength of resin composite to dentin: an in vitro study / Efeito de nanopartículas de quitosana na resistência a união por microtração da resina composta à dentina: um estudo in vitro

Objective: The purpose of this study was to evaluate the effect of chitosan nanoparticles on microtensile bond strength of resin composite to dentin using self etch adhesive after aging. Material and Methods: A total number of 90 freshly extracted, sound human molar teeth. Flat tooth surface was gained after cut of the occlusal surface. Three main groups according to pretreatment of dentin before adhesive application; 0.2 % chitosan, 2.5 % chitosan and no treatment control group. Universal self etch adhesive were applied according to manufacture instruction and 4 mm of Feltik Z250 xt composite. Storage of specimens for 1 day, 3 months and 6 months in 37O C distilled water. After that, the tooth was sectioned to beams of 1 mm x8 mm sticks for microtensile bond strength test using universal testing machine. Scanning electron microscope (SEM) was used to evalute the effect of chitosan nanoparticles on dentin and smear layer. Kruskal-Wallis test was used to compare between the three groups as well as the three aging periods. Dunn's test was used for pair-wise comparisons. The significance level was set at P ≤ 0.05. Results: chitosan 0.2% is statistically significant increase in bond strength than chitosan 2.5% and control in one day group. Three months chitosan 0.2 % groups have statistically significant increase in bond strength than chitosan 2.5%. It was found in 6 months that control and chitosan 0.2 % have statistically significant increase in bond strength than chitosan 2.5%. There was statistically significant difference found between the three studied groups regarding bond strength at different storage times . Conclusion: Microtensile bond strength was influenced by different chitosan concentration. Different aging periods had no effect on the microtensile bond strength without application of chitosan and with application of 2.5% chitosan concentration. (AU)

Introdução: O objetivo deste estudo foi avaliar o efeito das nanopartículas de quitosana na resistência da microtração de união do compósito de resina à dentina usando adesivo autocondicionante após o envelhecimento. Material e Métodos: Foram utilizados um total de 90 dentes molares humanos extraídos e sadios. A superfície plana do dente foi obtida após o corte da superfície oclusal. Os dentes foram divididos em três grupos principais de acordo com o pré-tratamento da dentina e antes da aplicação do adesivo: 0,2% de quitosana, 2,5% de quitosana e nenhum tratamento foi utilizado no grupo controle. O adesivo autocondicionante universal foi aplicado de acordo com as instruções do fabricante e 4 mm de composito Feltik Z250 xt foi inserido. O armazenamento de amostras foi realizado por 1 dia, 3 meses e 6 meses em água destilada a 37 °C. Depois disso, o dente foi seccionado em peças de 1 mm x 8 mm para teste de resistência de união por microtração, utilizando máquina de teste universal. Microscópio eletrônico de varredura (MEV) foi usado para avaliar o efeito das nanopartículas de quitosana na dentina e na camada de smear layer. O teste de Kruskal-Wallis foi utilizado para comparar os três grupos e os três períodos de envelhecimento. O teste de Dunn foi usado para comparação pareada dos grupos. O nível de significância foi estabelecido em P ≤ 0,05. (AU)

Pulpal repair after direct pulp capping with new bioceramic materials: A comparative histological study.

AIM: To histopathologically evaluate the pulpal healing after direct pulp capping with TotalFill and compared it with Neo MTA Plus in human tooth cultures. METHODS: Forty sound human premolars freshly extracted for orthodontic reasons were randomly assigned to two experimental groups; group I: TotalFill and group II: Neo MTA Plus. Standardized Class V cavities were prepared on the buccal surface of each tooth where the pulp exposure was performed with a dental explorer. The pulp-exposed teeth were immediately capped with one of the tested materials. The prepared cavities were then finally restored with glass-ionomer cement. Teeth were cultured for three weeks and three months. Then, the cultured teeth were demineralized, sectioned and stained for histopathological evaluation. Data collected and statistically analyzed by using Fisher's exact test. The significance level was set at P ≤ 0.05. RESULTS: Histopathological analysis showed complete dentin bridge formation and an absence of inflammatory pulp response. Statistical analysis showed no significant differences between the TotalFill and Neo MTA Plus groups during the observation periods. However, a significantly higher thickness of the dentin bridge was found in the group of teeth treated with TotalFill at three months. CONCLUSIONS: TotalFill produced similar favorable pulp healing and repair, and were comparable to Neo MTA Plus. Furthermore, TotalFill can form a thicker dentin bridge compared with Neo MTA Plus.

The reparative capacity of different bioactive dental materials for direct pulp capping.

BACKGROUND: Maintaining pulp vitality is a major objective in restorative dentistry. Direct pulp capping (DPC) is considered a way to enhance pulp healing and induce reparative dentin. In the present study, 3 capping materials were used and compared in terms of promoting pulp tissue healing after mechanical exposure. OBJECTIVES: The aim of the study was to evaluate the reparative capacity of Biodentine™ (BD), TheraCal® LC and TotalFill® as DPC materials and to assess dentin bridge formation. MATERIAL AND METHODS: The experiment required 3 groups (1-week group, 1-month group and 3-months group), each consisting of 24 fresh human premolars extracted for orthodontic reasons. A cavity was prepared on the buccal surface of each tooth and the pulp tissue was penetrated to a depth of approx. 1.0 mm. After exposure, hemostasis was obtained and the pulp-capping agents BD, TheraCal LC and TotalFill were applied. A final restoration with GC Fuji IX GP Fast (GC Corporation, Tokyo, Japan) was applied to each tooth to ensure an adequate coronal seal. Tissue samples were collected at 1 week, 1 month and 3 months. The samples were demineralized, sectioned, stained, and histologically graded. RESULTS: There was a statistically significant difference between TheraCal LC and both BD and TotalFill in terms of pulpal inflammation during the 3 capping periods, while BD and TotalFill showed comparable results, with no statistically significant difference between their results in the 3 capping periods. CONCLUSIONS: TotalFill a newly developed pulp-capping material, offers results comparable to BD in addition to its advantageous handling properties. Although TheraCal LC contains resin ingredients, given proper curing, it seems to be a successful material for DPC and offers superior handling properties.

The "11 O'clock Heel First" technique for microvascular end-to-side anastomosis.

BACKGROUND: The heel of a microvascular end-to-side anastomosis is a common site for technical imperfections. We describe a simple technique to overcome this challenge. The aim of the technique is to insert all the sutures in an inside-to-outside manner at the heel area on the donor side of the anastomosis. This technique has first been tested in a laboratory setting and then was further elaborated in a clinical setting. MATERIALS AND METHODS: One hundred and twenty adult albino Wistar rats of both genders were randomized into the following two groups: (A) Control, 48 rats, representing approximately 40% of the total sample, underwent the usual two anchoring stitch technique; (B) Study group, 72 rats, representing approximately 60% of the total sample, underwent the technique described. Patency was confirmed both clinically and by the use of fluorescein angiography. Rat weight, diameter of both the donor and recipient vessels, type of anastomosis (arterio-arterial or arterio-venous) and angiographic findings were used as variables. A P value of less than 0.05 was considered significant. RESULTS: The proposed technique had increased patency rates as compared to the standard technique, which was statistically significant (P = 0.021). However, there was no difference between the patency rates of arterio-arterial and arterio-venous atastomoses. CONCLUSION: The proposed technique is useful for perfecting the heel area of a microvascular end-to-side anastomosis in both laboratory and clinical settings.

Nanoleakage Evaluation of Posterior Teeth Restored with Low Shrinkable Resin Composite- An invitro Study.

INTRODUCTION: The effect of nanoleakage on the integrity of resin-dentin bond has been in interest for long-term adhesion. AIM: This study evaluated the nanoleakage in premolar teeth restored with low shrinkable resin composite. MATERIALS AND METHODS: A total of 40 human premolars were used for nanoleakage evaluation in this study. Each group was divided into four equal groups; Group A: using silorane with its adhesive system. Group B: using silorane with G-bond. Group C: using Filtek supreme composite with G-bond. Group D: using Filtek supreme composite with AdheSE adhesive. Nanoleakage analysed using Scaning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectrometery (EDX). RESULTS: The amount of silver present in hybrid layer depend on the adhesive used; this indicated different nanoleakage expressions in different adhesive systems. Filtek Z350 composite with G-bond showed clear silver uptake in both the adhesive and hybrid layer. Low shrinkable resin composite (silorane) with its adhesive system showed less silver penetration and slight silver peak on the elemental energy spectroscopy of energy dispersive X-Ray spectrometry (EDS) as compared to other samples. CONCLUSION: Adhesives used between different groups, influence the location and degree of nanoleakage. There is difference in nanoleakage patterns between two-step and one-step adhesives and also among the one-step adhesives themselves.

The effect of three polishing systems on surface roughness of flowable, microhybrid, and packable resin composites.

OBJECTIVES: The aim of this study was to evaluate the effects of three different polishing systems on the surface roughness of three types of resin composite materials. MATERIALS AND METHODS: Three types of resin composites (Heliomolar flow, TPH spectrum, and Tetric Ceram HB) and three polishing systems (Astropol, Enhance, and Soflex) were used. A total number of 40 samples were prepared from each one of the restorative materials and divided randomly into four groups (n = 10) according to the polishing procedure. The first group underwent no treatment and was used as a control group. Each one of the remaining groups was polished with one of the tested polishing systems. After completion of sample preparation, the mean surface roughness (Ra) value was measured using a surface profilometer. Data were analyzed using one-way analysis of variance (ANOVA). RESULTS: The control group of each material recorded the lowest Ra value. Among the tested polishing systems, the groups finished with Soflex system exhibited the lowest Ra value. Among the resin composites, Heliomolar flow exhibited the lowest Ra value, regardless of the polishing system used. CONCLUSIONS: The smoothest surface of all types of resin composite was achieved under Mylar strip.

Evaluation of cuspal deflection in premolar teeth restored with low shrinkable resin composite (in vitro study).

OBJECTIVES: This study evaluated cuspal deflection in premolar teeth restored with low shrinkable resin composite. MATERIALS AND METHODS: A total of 40 human premolars were used for cuspal deflection evaluation in this study. Each group was divided into four equal groups according to the type of resin composite and the adhesive used as follows: group A: Using low shrinkable resin composite (silorane) with its adhesive system; group B: Using low shrinkable composite (silorane) with G-bond; group C: Using Filtek Z350 composite with G-bond; and group D: Using Filtek Z350 composite with AdheSE. Cusp deflection was detected using Universal measuring microscope and laser horizontal metroscope. RESULTS: This study was done to investigate the effect of polymerization shrinkage stresses of two resin composite materials (Filtek Z350 and Filtek P90) on cuspal deflection of mesio-occluso-distal restoration. For this study, the extracted non-carious maxillary second premolars were selected. Forty teeth that showed no more than 5% variation in their dimensions were used. A significant increase in cuspal deflection of cavities restored with the methacrylate-based (Filtek Z350) compared with the silorane (P90) resin-based composites was obtained. CONCLUSION: The change in the organic matrix or materials formulation of the resin composite using silorane has a positive effect on controlling the cusp deflection.

An unusual aberrant muscle in congenital clubfoot: an intraoperative finding.

Congenital clubfoot is a common congenital deformity, characterized by equinus of the hindfoot and adduction of the midfoot and forefoot, with varus through the subtalar joint complex. A cavus deformity will also be present. The etiology of this congenital deformity remains elusive. Muscle anomalies are not commonly found in patients with idiopathic clubfoot, and, when present, their significance is not clear. The presence of a flexor digitorum accessorius longus muscle and an accessory soleus muscle found at surgical correction of clubfoot deformity has been previously reported. Our case was a female child, aged 2 years, 3 months, who developed bilateral relapsed congenital clubfoot. She was found to have an unusual aberrant muscle in both legs. This was discovered accidentally during surgical correction of her deformity through posteromedial soft tissue release. This muscle might have contributed to the hindfoot varus and equinus in the clubfoot deformity, because the latter were completely corrected after release of the muscle from its insertion. Awareness of such a new anatomic variant, with the other anatomic variants found in clubfoot deformity, will not only improve our understanding of normal lower limb development, but could also lead to improved genetic counseling and diagnostic and treatment methods of such a common congenital deformity.