METS2 Discussion Group 1

Discussion Grou

Developmental changes in testicular interstitium in the Najdi Ram Lambs

AbstractThis experiment was designed to study the relationship between growth rate and sexual development in Najdi ram lambs. Forty-five Najdi ram lambs were used in nine age groups (1–9th month age), keeping 5 lambs in each group. Results show that mean testis size and scrotal circumference increased at a constant rate, reaching a maximum value of 392.00±2.00g and 25.00±0.32cm respectively, at the age of 9months. A similar trend of growth was observed for the mean body weight, reaching a maximum value of 40.2±0.20kg at the age of 9months. There was a positive correlation between the increasing rates of body weight and size of the testis. There were significant differences (P<0.05) in testis size, scrotal circumference and body weight of lambs between all ages (1–9months). The histological section of testis showed that a small number of mature sperms appeared in the eighth month of age and their numbers increased in the ninth month. In conclusion, the current findings indicated that puberty in Najdi rams occurs between the 8th and 9th months of age

METS2 Discussion Group 1

Discussion Grou

Detection of Glial Fibrillary Acidic Protein in Patient Plasma Using On-Chip Graphene Field-Effect Biosensors, in Comparison with ELISA and Single-Molecule Array

Glial fibrillary acidic protein (GFAP) is a discriminative blood biomarker for many neurological diseases, such as traumatic brain injury. Detection of GFAP in buffer solutions using biosensors has been demonstrated, but accurate quantification of GFAP in patient samples has not been reported, yet in urgent need. Herein, we demonstrate a robust on-chip graphene field-effect transistor (GFET) biosensing method for sensitive and ultrafast detection of GFAP in patient plasma. Patients with moderate-severe traumatic brain injuries, defined by the Mayo classification, are recruited to provide plasma samples. The binding of target GFAP with the specific antibodies that are conjugated on a monolayer GFET device triggers the shift of its Dirac point, and this signal change is correlated with the GFAP concentration in the patient plasma. The limit of detection (LOD) values of 20 fg/mL (400 aM) in buffer solution and 231 fg/mL (4 fM) in patient plasma have been achieved using this approach. In parallel, for the first time, we compare our results to the state-of-the-art single-molecule array (Simoa) technology and the classic enzyme-linked immunosorbent assay (ELISA) for reference. The GFET biosensor shows competitive LOD to Simoa (1.18 pg/mL) and faster sample-to-result time (<15 min), and also it is cheaper and more user-friendly. In comparison to ELISA, GFET offers advantages of total detection time, detection sensitivity, and simplicity. This GFET biosensing platform holds high promise for the point-of-care diagnosis and monitoring of traumatic brain injury in GP surgeries and patient homes

Analysis of the mechanical properties of wood-plastic composites based on agriculture chili pepper waste

In this study, a new composite material conception based on polypropylene (PP) and wood particles obtained from agricultural waste was investigated. Specifically, stalks and leafs of chili plants of the region of New Mexico, Texas, USA were used as a plant-based reinforcing material. For this, a design ofexperiments (DOE) is proposed considering different percentages of PP, wood, fire retardant, coupling agent and UV stabilizer, different mesh sizes are also considered. Samples were obtained using an extrusion molding machine. A statistical analysis is proposed to obtain the optimal percentages of the components considered in the fabrication of the samples in order to enhance the mechanical and morphologic properties of this new composite. Results show that the yield stress, breaking stress and ultimate tensile stress can be maximized with a proportion of 3 to 1 (63,75% PP and 21,25% wood fiber) of PP and wood fiber

Graphene sensor arrays for rapid and accurate detection of pancreatic cancer exosomes in patients' blood plasma samples

Biosensors based on graphene field effect transistors (GFETs) have the potential to enable the development of point-of-care diagnostic tools for early stage disease detection. However, issues with reproducibility and manufacturing yields of graphene sensors, but also with Debye screening and unwanted detection of nonspecific species, have prevented the wider clinical use of graphene technology. Here, we demonstrate that our wafer-scalable GFETs array platform enables meaningful clinical results. As a case study of high clinical relevance, we demonstrate an accurate and robust portable GFET array biosensor platform for the detection of pancreatic ductal adenocarcinoma (PDAC) in patients’ plasma through specific exosomes (GPC-1 expression) within 45 min. In order to facilitate reproducible detection in blood plasma, we optimized the analytical performance of GFET biosensors via the application of an internal control channel and the development of an optimized test protocol. Based on samples from 18 PDAC patients and 8 healthy controls, the GFET biosensor arrays could accurately discriminate between the two groups while being able to detect early cancer stages including stages 1 and 2. Furthermore, we confirmed the higher expression of GPC-1 and found that the concentration in PDAC plasma was on average more than 1 order of magnitude higher than in healthy samples. We found that these characteristics of GPC-1 cancerous exosomes are responsible for an increase in the number of target exosomes on the surface of graphene, leading to an improved signal response of the GFET biosensors. This GFET biosensor platform holds great promise for the development of an accurate tool for the rapid diagnosis of pancreatic cancer

Modeling of pH Distribution Over Corrosion Sites

Different corrosion reactions were studied as a function of the bulk electrolyte pH, acidic, neutral and alkaline pH. Three variables, H+, OH‘ and dissolved metal ions concentration were modeled along with the water ionization reaction as a homogeneous reaction. Different geometries were selected to simulate metal corrosion around inclusions, similar to A1 and steel alloys corrosion. Modeling showed that reduction of O2 at an inclusion caused the pH to increase at and around the inclusion. Coupling the reaction to dissolution of the surrounding metal matrix showed that the pH was decreased over the anodic dissolution region. The pH distribution was strongly affected by the bulk pH and was confined to 50 μm distance from the surface. Metal ions concentration was found to be affected mostly by the system geometry. Keywords: Heterogeneous reactions, Finite element, aluminum alloys Corrosion, Inclusion

e-Learning transformation during the covid-19 pandemic among faculty members at princess nourah bint abdul rahman university

It seeks to shed light on the problems of the transition to e-learning during the Covid-19 pandemic among the collaborators of the Princess Nourah Bint Abdul Rahman University faculty, through a descriptive and analytical approach. The tool was represented with the help of a questionnaire organized by the researcher divided into 3 axes, concluding that organizational problems such as problems of slowness, download problems, conversation failure and their obstacles, have the need to articulate activities, criteria of evaluation and questions according to the specifications and tests of distanceSe busca arrojar luz sobre los problemas de la transición al e-learning durante la pandemia de Covid-19 entre los colaboradores de la facultad de la Universidad Princess Nourah Bint Abdul Rahman, a traves de un enfoque descriptivo y analítico. La herramienta fue representada con la ayuda de un cuestionario organizado por el investigador dividido en 3 ejes, concluyendo que los problemas organizacionales como problemas netos de lentitud, problemas de descarga, falla de conversación y sus obstáculos, tienen la necesidad de articular actividades, criterios de evaluación y preguntas acordes con las especificaciones y pruebas de la educación a distancia