Improvement the wear behavior of low carbon steels by friction stir processing

et al.;Nanomechanics, Inc.;S.C. Total Lubricants Romania S.A.;SC Etansari Grafex SRL;SC NASDIS Consulting SRL;SC Techno Volt SRL13th International Conference on Tribology, ROTRIB 2016 -- 22 September 2016 through 24 September 2016 -- -- 126834A low carbon structural steel was surface-hardened by friction stir processing (FSP) through 4 mm thickness from the surface. The hardness of the alloy increased from 140 Hv0.1 to about 240 Hv0.1 after single-pass FSP. This improvement came from the substantial microstructural refinement due to both severe plastic deformation and dynamic recrystallization. Both yield and tensile strength of the alloy increased without a considerable decrease in ductility after FSP. Friction and wear behavior of the alloy before and after FSP was investigated by a pin-on-disk type tribometer according to ASTM-G133. The substantial increase in both hardness and yield strength resulted in a considerable improvement in wear resistance of the alloy depending on applied pressure. In this study, metallurgical and mechanical reasons for such improvement in wear behavior and any change in wear mechanisms after FSP were investigated. © Published under licence by IOP Publishing Ltd

Appropriateness of anemia management in hemodialysis patients

AbstractThe anemia of end stage renal disease (ESRD) is common and often severe complication that can be managed successfully by erythropoiesis-stimulating agents (ESA) administration.AimsTo investigate current practice of anemia management in hemodialysis patients and to assess the appropriateness of anemia management by comparing observed practice to the Kidney Disease Outcomes Quality Initiative (KDOQI) guideline recommendations.Settings and designThe study was conducted at two hemodialysis centers in Riyadh, Saudi Arabia. Data on anemia parameters, comorbidities, ESA dosing and iron supplementation were collected. The data were collected for 7 months retrospectively from April to the end of May 2008 and prospectively from June to October 2008. Patients who were over 18 years of age with ESRD undergoing hemodialysis were included. Patients were excluded if they have cancer or receiving chemotherapy or radiotherapy.ResultsData were collected from 87 patients. Mean Hgb value for those patients was 11.16±0.97g/dL. Thirty-nine patients (45%) had mean Hgb values between 11.0 and 12.0g/dL the target range recommended by KDOQI guideline. The mean weekly prescribed dose of erythropoietin was 8099±5946IU/Week (135±99IU/kg/Week). Information on ferritin concentrations was available for 48 (55%) patients. The mean serum ferritin concentration for those patients was 693±420.5ng/mL. Fifty-two patients had transferrin saturation (TSAT) values recorded. The mean TSAT value was 38.5±19.7%. Conclusions: There is an opportunity to improve anemia management in hemodialysis patients particularly thorough evaluation of causes of inadequate response rate and better monitoring and management of iron status

Complications of ultrasound-guided percutaneous native kidney biopsies in children: A single center experience

Introduction: Percutaneous kidney biopsy is a necessary tool to diagnose many kidney diseases. However, major complications were reported in adults, including bleeding in the kidney or around it, creation of arteriovenous fistula, wound infection, damage to adjacent organs, or even loss of the kidney. Such complications can rapidly develop serious consequences. Exploring risk factors might help in preventing them.Objective: The current study aims to evaluate and explore the complications that happened after percutaneous kidney biopsy in children and associated risk factors.Methodology: A retrospective record-based study was conducted by reviewing the medical records of children with post-ultrasound-guided percutaneous kidney biopsy complications at King Saud Medical City, a tertiary hospital in Riyadh, Saudi Arabia during the period from May 2014 to June 2021. Data were extracted using pre-structured data collection sheet. Data collected included children’s age, gender, primary disease, laboratory findings, and kidney complications with needed management. Results: The study identified 76 children who had undergone 86 ultrasound-guided percutaneous kidney biopsies in the study period and fulfil the inclusion criteria. Children’s ages ranged from 1 years to 15 years with a mean age of 7.3 ± 4.0 years old. Most of the study children had nephrotic syndrome (61.6%; 53), followed by glomerulonephritis (25.6%; 22). Thirty-five (40.7%) children developed at least one of the complications. The most-reported complication was microscopic haematuria (32.6%; 28), followed by gross haematuria (3.5%; 3), Flank pain was reported among 3 (3.5%) children also and hematoma (1 child), only 2 children (3.9%) among those who had no complications recorded Haemoglobin drop > 2 g/dl compared to 3 of those who had complications with no statistical significance (p = .365). Prothrombin time was significantly higher among children who had renal complications than others who had not (11.7 ± 1.8 vs. 10.8 ± 1.2 seconds; p = .022).Conclusion: Suggestive by the low need to intervene in complications, ultrasound-guided percutaneous kidney biopsy is a relatively safe procedure in children. Even in the most commonly observed complication, i.e. hemorrhagic ones, blood transfusion is rarely needed

Appropriateness of Anaemia management in haemodialysis patients

The anemia of end stage renal disease (ESRD) is common and often severe complication that can be managed successfully by erythropoiesis-stimulating agents (ESA) administration. Aim: to investigate current practice of anaemia management in haemodialysis patients and to assess the appropriateness of anaemia management by comparing observed practice to the Kidney Disease Outcomes Quality Initiative (KDOQI) guideline recommendations. Setting and design: The study was conducted at two haemodialysis centers in Riyadh, Saudi Arabia. Data on anaemia parameters, comorbidities, ESA dosing and iron supplementation were collected. The data was collected for 7 months retrospectively from April to the end of May 2008 and prospectively from June to October 2008. Patients who were over 18 years of age with ESRD undergoing haemodialysis were included. Patients were excluded if they have cancer or receiving chemotherapy or radiotherapy. Results: Data were collected for 87 patients. Mean Hgb value for those patients was 11.16± 0.97 g/dL. Thirty nine of patients (45%) had mean Hgb values between 11.0 and 12.0 g/dL the target range recommended by KDOQI guideline. The mean weekly prescribed dose of erythropoietin was 8099± 5946 IU/Week (135 ±99 IU/Kg/Week). Information on ferritin concentrations was available for 48 (55%) patients. The mean serum ferritin concentration for those patients was 693 ±420.5 ng/mL. Fifty two patients had transferrin saturation (TSAT) values recorded. The mean TSAT value was 38.5% ±19.7. Conclusions: there is opportunity to improve anemia management in hemodialysis patients particularly thorough evaluation of causes of inadequate response rate and better monitoring and management of iron statusKing Saud Universit