Micro-abrasion–corrosion of a Co–Cr/UHMWPE couple in Ringer's solution : an approach to construction of mechanism and synergism maps for application to bio-implants

In studies of tribo-corrosion, the degradation of bio-materials has become of increasing research interest in recent years. This is because, in many cases, the interactions of the tribological and corrosion component in biological environments are not well understood. Moreover, the wide range of variables involved in the tribo-corrosion process, and the variety of materials used in such conditions, means that there are few systematic studies where materials and operating conditions are optimized. In the total replacement of hip joints, the Co-Cr/UHMWPE couple has been used widely. However, the application of any replacement joint for biological conditions will depend on many factors including the activity of the patient and the overall load imposed on the artificial joint. This means evaluation of the tribo-corrosion behaviour over a multi parameter space is important in order to assess the degradation possible for many patient/activity and body mass categories.In this work, the performance of a Co-Cr/UHMWPE couple was evaluated in Ringer's solution in a tribological situation where micron size particles particles were entrained in the contact - micro-abrasion-corrosion. The effects of applied load and potential were investigated in the study. Micro-abrasion-corrosion maps were constructed for the material indicating the mechanism of degradation, the extent of wastage and of synergy/antagonism involved in the tribo-corrosion interaction

Anti-Arthritic Effects of Magnolol in Human Interleukin 1β-Stimulated Fibroblast-Like Synoviocytes and in a Rat Arthritis Model

Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5′-Diallyl-biphenyl-2,2′-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E2, and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5–25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases

Anesthetic Propofol Reduces Endotoxic Inflammation by Inhibiting Reactive Oxygen Species-regulated Akt/IKKβ/NF-κB Signaling

BACKGROUND: Anesthetic propofol has immunomodulatory effects, particularly in the area of anti-inflammation. Bacterial endotoxin lipopolysaccharide (LPS) induces inflammation through toll-like receptor (TLR) 4 signaling. We investigated the molecular actions of propofol against LPS/TLR4-induced inflammatory activation in murine RAW264.7 macrophages. METHODOLOGY/PRINCIPAL FINDINGS: Non-cytotoxic levels of propofol reduced LPS-induced inducible nitric oxide synthase (iNOS) and NO as determined by western blotting and the Griess reaction, respectively. Propofol also reduced the production of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 as detected by enzyme-linked immunosorbent assays. Western blot analysis showed propofol inhibited LPS-induced activation and phosphorylation of IKKβ (Ser180) and nuclear factor (NF)-κB (Ser536); the subsequent nuclear translocation of NF-κB p65 was also reduced. Additionally, propofol inhibited LPS-induced Akt activation and phosphorylation (Ser473) partly by reducing reactive oxygen species (ROS) generation; inter-regulation that ROS regulated Akt followed by NF-κB activation was found to be crucial for LPS-induced inflammatory responses in macrophages. An in vivo study using C57BL/6 mice also demonstrated the anti-inflammatory properties against LPS in peritoneal macrophages. CONCLUSIONS/SIGNIFICANCE: These results suggest that propofol reduces LPS-induced inflammatory responses in macrophages by inhibiting the interconnected ROS/Akt/IKKβ/NF-κB signaling pathways

Managing the Total Quality Management System in Iraqi Universities

أن الكثير من الجامعات العراقية وكذلك جامعات إقليم كوردستان بدأت بشكل واضح في استخدام نظام الجودةالشاملة ( Total Quality Management) ، ولكن كانت بانتظارها مجموعة من المعوقات النظرية والعملية على حد سواء، من خلال وجود القوانين والتعليمات التي تتعارض مع نظام الجودة. وهدفت هذه الدراسة الى توضيح مفاهيم الجودة ومعايير وأساليب تطبيقها وأهمية شمولها في جميع مفاصل المؤسسة والجامعة. وذلك من خلال الإجابة عن السؤال التالي (ماهي الطريقة الأفضل لتجاوز المعوقات أمام تطبيق نظام الجودة الشاملة في الجامعات العراقية ؟). وتم استخدام استبانة مكونة من 52 فقرة موزعة على 8 محاور  رئيسية ، ومن نتائج  البحث  إن محوري القيادة و الإتصالات من أكثر المحاور جودة و يحتاج محور الآلات و المعدات الى إهتمام أكبر من قبل الإدارة اما بقية المحاورفكانت  ضمن النظاق النموذجي . وفي ضوء النتائج تم وضع بعض التوصيات من أهمها تعزيز دور المؤسسات التعليمية و الأكاديمية في تبني و تطوير معايير محلية أو إقليمية بالإضافة الى تحديث القوانين و القرارات المحلية كي تتناسب مع معايير ضمان الجودة للقطاع التعليمي العالمية .  Many of the Iraqi universities, as well as the universities of the Kurdistan Region, have clearly begun to use the Total Quality Management system, but a set of both theoretical and practical obstacles awaited them, through the presence of laws and instructions that contradict the quality system. This study aimed to clarify the concepts of quality, standards and methods of their application, and the importance of including them in all aspects of the institution and the university. And that is by answering the following question (What is the best way to overcome the obstacles to the application of the total quality system in Iraqi universities?). A questionnaire consisting of 52 items distributed on 8 main axes was used, and from the results of the research, the leadership and communication axes are of the highest quality, and the machines and equipment axes need more attention by the administration, while the rest of the axes were within the model range. In light of the results, some recommendations were developed, the most important of which is to strengthen the role of educational and academic institutions in adopting and developing local or regional standards, in addition to updating local laws and decisions to match the international quality assurance standards for the educational sector

Some thoughts on micro-abrasion mapping of steels in corrosive environments

There has been significant recent interest in the interactions of micro-abrasion in aqueous conditions, particularly when the environment is corrosive. This is due to the fact that there are many micro-scale-abrasion processes where the presence of the corrosive media may modify the wear on the surface. Furthermore, if the surface dissolves, the mechanical properties of the surface may be modified as a result of the effects of corrosion. In this work, the micro-abrasion of a steel/polymer couple was studied in carbonate/bicarbonate solution. The effects of two variables, applied load and potential, were investigated on the wear rate enabling quantification of the corrosion and wear contributions. Scanning Electron and Atomic Force Microscopy were used to characterize the surfaces following micro-abrasion-corrosion. The results indicated possible micro-abrasion-corrosion mechanisms on the surface. These regimes were suggested on the basis of the ratio of the micro-abrasion to the corrosion rate. In addition, micro-abrasion-corrosion maps were constructed showing the transitions between the micro-abrasion-corrosion regimes as a function of load and applied potential

On the construction of micro-abrasion maps for a steel/polymer couple in corrosive environments

There has been significant recent interest in the interactions of micro-abrasion in aqueous conditions, particularly when the environment is corrosive. This is due to the fact that there are many micro-scale-abrasion processes where the presence of the corrosive media may modify the wear on the surface. Furthermore, if the surface dissolves, the mechanical properties of the surface may be modified as a result of the effects of corrosion. In this work, the micro-abrasion of a steel/polymer couple was studied in carbonate/bicarbonate solution. The effects of two variables, applied load and potential, were investigated on the wear rate enabling quantification of the corrosion and wear contributions. Scanning Electron and Atomic Force Microscopy were used to characterize the surfaces following micro-abrasion-corrosion. The results indicated possible micro-abrasion-corrosion mechanisms on the surface. These regimes were suggested on the basis of the ratio of the micro-abrasion to the corrosion rate. In addition, micro-abrasion-corrosion maps were constructed showing the transitions between the micro-abrasion-corrosion regimes as a function of load and applied potential