Mostafa Abdelsalam

In recent decades, the finiteelement method (FEM) has been increasingly recognized as an integral computational tool for the analysis and simulation of manufacturing processes, such as the ball burnishing operation. The current investigation employs FEM to conduct a numerical analysis on the influence of various burnishing parameters–namely, burnishing speed, feed rate, and penetration depth–on the residual stress and strain energy in workpieces processed with three different types of ball burnishing tools: rigid, spring-loaded, and pneumatic. A sophisticated three-dimensional ANSYS finite element model was meticulously crafted to emulate the ball burnishing process. This model allowed for the precise control and variation of input parameters and facilitated a detailed examination of their impact on the predicted residual stress and strain energy in the workpieces. The computational outcomes reveal a direct relationship between the burnishing speed and the induced residual stress and strain energy, with both metrics escalating to a maximum at a specific burnishing speed before exhibiting a subsequent decline. Notably, the model Computes that, at a penetration depth of 0.4 mm, the residual stress and strain energy attain a maximum of 2330 MPa and 107.6 mJ, respectively. Furthermore, the simulation delineates a dependency of the residual stress and strain energy behavior on the type of ball burnishing tool deployed. For instance, the rigid tool is characterized by a consistent escalation in stress and energy up to a speed of 500 revolutions per minute (RPM). Conversely, the spring tool demonstrates a more confined spectrum of stress and energy, peaking at 600 RPM with a feed rate of 0.08 mm/revolution and a penetration depth of 0.4 mm. Meanwhile, the pneumatic tool’s simulation results suggest an insensitivity of the residual stress and strain energy to changes in penetration depth. These exclusively numerical results shed light on the intricate relationship between the burnishing parameters and the consequent simulated mechanical attributes of the workpiece. Additionally, the computational data highlight the disparities in the performance of different ball burnishing tools as anticipated by the finite element analysis. This information provides a theoretical basis for refining the ball burnishing process and customizing surface characteristics to conform to diverse industrial applications as per the predictions of the simulation model. Prospective research endeavors will focus on experimental validation of the simulation results to ascertain the fidelity and practical relevance of the developed model.

Background/Objectives: Diabetic nephropathy (DN) is a serious complication of diabetes mellitus. This clinical condition is diagnosed through the detection of microalbuminuria. Molecular biomarkers such as MicroRNA-192 may play a role in the early diagnosis of this condition. This study aims to compare the serum concentrations of MicroRNA-192 in diabetic patients with and without DN and in healthy individuals. Methods: This study was a retrospective case-control study that included three groups. Group I included diabetic patients without DN, Group II included patients with DN, and Group III included healthy control subjects. Blood samples were obtained from each participant and subjected to a full biochemical study including creatinine, albumin, and the detection of MicroRNA-192 by real-time polymerase chain reaction. Results: There were significant differences among the MicroRNA-192 levels in the three groups (p-0.001). There was a significant increase in the MicroRNA-192 level in Group I (1.35 ± 7 0.5) compared with Group II (0.65 ± 7 0.2, p3 = 0.001) and Group III (0.83 ± 7 0.3, p1-0.001). There was a significant reduction in the MicroRNA-192 level in Group II compared with Group III (p2-0.001). Conclusions: This study highlights the potential role of serum miR-192 as a noninvasive biomarker for the early detection of DN in patients with type 2 DM. Our findings demonstrated that serum miR-192 levels were significantly reduced in patients with DN compared with diabetic patients without nephropathy and healthy controls, suggesting the possible protective role of miR-192 in early disease stages.

Diabetic nephropathy (DN) is a serious complication of Diabetes mellitus. This clinical condition is diagnosed through detection of microalbuminuria. Molecular biomarkers such as MicroRNA-192 may play a role in early diagnosis of this condition. The objective of this study was to assess the serum concentration of MicroRNA-192 in different stages of DN in comparison to a group of healthy individuals. The study was a retrospective case-control study included three groups. Group I included patients with early DN, group II included patients with late DN and group III included healthy control subjects. Blood samples were obtained from each participant and subjected to full biochemical study including creatinine, albumin and detection of MicroRNA-192 by real time polymerase chain reaction. There was significant difference between MicroRNA-192 levels in the three groups (P=0.001). There was significant increase in MicroRNA-192 level in group I (1.35±7 0.5) compared to group II (0.65±7 0.2, P3=0.001) and group III (0.83±7 0.3, P1=0.001). There was significant reduction in MicroRNA-192 level in group II compared to group III (P2=0.001). The study of diagnostic accuracy of MicroRNA-192 in the patients revealed good accuracy in the differentiation of early DN from control subjects (sensitivity 62% and specificity 86%) and good accuracy in the differentiation of early from late DN (sensitivity and specificity each 82%). The present study highlights that MicroRNA-192 is a good diagnostic tool for early detection of DN. MicroRNA-192 correlates significantly with estimated glomerular filtration rate, albuminuria, and renal functions tests. MicroRNA-192 might play role in the development of DN.

The metal burnishing process is a vital and modern technique for achieving high-quality surface finishes. This research uses the Taguchi and RSM (Response Surface Methodology) methods to optimize the ball burnishing process parameters. Three different tools were specifically designed and utilized in this study, and a Taguchi L16 matrix was employed for the experimental design. The results of surface roughness parameters and surface out-of-roundness were conducted. The resulting data was subjected to square regression analysis. The findings of this research demonstrate that both the tool type selected as well as the burnishing parameters significantly influence the surface roughness and out-of-roundness values. The analysis revealed intricate relationships between these factors, providing valuable insights for process optimization. Specifically, the research identified optimal parameter combinations for each tool type, leading to improved surface quality. The rigid tool exhibited minimum surface roughness at a rotational speed of 450 RPM, a feed rate of 0.09 mm/rev, and a penetration depth of 0.35 mm. While the spring tool achieved minimum surface roughness at a rotational speed of 500 RPM, a feed rate of 0.09 mm/rev, and a penetration depth of 0.35 mm. For out-of-roundness, the rigid tool exhibited minimum out-of-roundness at a rotational speed of 600 RPM, a feed rate of 0.12 mm/rev, and a penetration depth of 0.35 mm. While the spring tool achieved minimum out-of-roundness at a rotational speed of 475 RPM, a feed rate of 0.09 mm/rev, and a penetration depth of 0.20 mm.

Metal burnishing is a prominent surface finishing process that plays a significant role in enhancing surface quality. This research focuses on the optimization of ball burnishing process parameters using the Taguchi and Response Surface Methodology (RSM) approaches. The study employs three distinct tools designed for this purpose, with experiments conducted. Surface roughness and outof-roundness measurements were performed. The Taguchi method demonstrated that the rigid tool achieved minimum surface roughness at a burnishing speed of 500 rpm, a feed rate of 0.09 mm/rev, and a penetration depth of 0.35 mm. Conversely, the pneumatic tool achieved the minimum surface roughness at a burnishing speed of 600 rpm, a feed rate of 0.1 mm/rev, and a penetration depth of 0.2 mm. Regarding out-ofroundness, the rigid tool achieved minimum values at a burnishing speed of 600 rpm, a feed rate of 0.11 mm/rev, and a penetration depth of 0.35 mm. For the pneumatic tool, the minimum value was yielded at a burnishing speed of 300 rpm, a feed rate of 0.09 mm/rev, and a depth of penetration of 0.2 mm. Furthermore, the Response Surface Methodology (RSM) revealed that the rigid tool achieved the minimum surface roughness at a burnishing speed of 496.9697 rpm, a feed rate of 0.09 mm/rev, and a penetration depth of 0.35 mm. In contrast, the spring tool achieved the minimum surface roughness at a burnishing speed of 451.5152 rpm, a feed rate of 0.12 mm/rev, and a penetration depth of 0.35 mm. Regarding out-of-roundness, the rigid tool yielded the minimum values at a burnishing speed of 600 rpm, a feed rate of 0.12 mm/rev, and a penetration depth of 0.35 mm. The pneumatic tool achieved the minimum out-of-roundness at a burnishing speed of 300 rpm, a feed rate of 0.1006 mm/rev, and a penetration depth of 0.2 mm

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This study aimed to assess the efficacy and safety of bedside removal of tunnelled hemodialysis catheter (TDC) by noninterventional nephrologists among adult patients. It is a retrospective study that involved 53 patients from March 2020 to February 2022 at the King Abdulaziz University Hospital (KAUH) Hemodialysis Centre in Jeddah, Saudi Arabia. Of the 53 participants, 60.4% were male and 40.6% female, and their mean age was 50.94 ± 18.89 years. The most common comorbidities were hypertension (HTN) in 47 (88.7%), diabetes mellitus (DM) in 24 (45.3%), and DM and HTN together in 23 (43.4%) patients. The most common site of TDC removal was the right internal jugular vein (77.4%). In 84.9% of the cases, the TDC was removed as an inpatient procedure, and in the majority of the cases (64.2%), the TDC was removed by a noninterventional nephrologist. The most common reasons for TDC removal were sepsis or clinical concerns for infection (64.2%) and TDC not needed (20.8%) due to recovery of the renal function or access maturation. Most patients (96.2%) suffered no complications; only one of 34 (%) patients with catheter removal by a noninterventional nephrologist had bleeding, which required more observation and monitoring before discharge on the same day. Our study revealed that the bedside TDC removal was well tolerated with a minimal complication rate.

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.