326 research outputs found

    The Effects of Surface Roughness on the Squeeze Film Characteristics with Couple stress fluids in Hip joint

    Get PDF
    On the basis of the Stokes micro continuum theory , This paper aims to study the effects of surface roughness and couple stress on the squeeze film Characteristics in hip joint. The cartilage is modeled as biphasic poro-elastic  matrix and synovial fluid is modeled as couple stress fluid  . Compared to the conventional Newtonian lubricant case, the couple stress and surface roughness effects characterized by the couple stress and surface roughness parameter signify an improvement in the squeeze film Characteristics. Increasing values of the  surface roughness  parameter increases the load-carrying capacity and the squeeze in the squeeze film can be decreased and provides a longer time to prevent sphere –plane surface contact .The approaching time of the sphere in reducing the film thickness h*=1 to h*= 0for the couple stress fluid lubricant which is longer than surface roughness. Keywords: Surface roughness, Couple stress fluid, Articular cartilage, Synovial fluid, Micro continuum theory, Hip joint

    The hydrodynamic Effect of the Hyaluronic Acid on the Performance Improvement of the Human Synovial Joint

    Get PDF
    The aim of this article is to present an the theoretical analysis of the problem is presented through a mathematical model  depended on the idea of a Hyaluronic acid (HA) in cartilage  and  synovial fluid surrounding the joints (hip, knee and ankle)  where are a major component of synovial fluid modified  Reynolds equation  governing the fluid film pressure was derived and solved analytically,  and closed form expressions for the squeeze film pressure and load carry capacity were  presented. The influence of film thickness and sliding motion on the squeeze film Characteristics were discussed .It has been found that the effect of  decreased film thickness tend to increased the load carry capacity , friction force and decreased  flow rate, The effect of decreased sliding motion tend to increasing frication force and decreased flow rate and  when additives Hyaluronic acid (HA) to bearing material (articular cartilage ) .The results indicate to  increasing pressure distribution (P) and improve both load carry capacity (W), friction force (F) Compared to the disease synovial hip joint. Keywords: Hyaluronic acid , Hip joint, load carry capacity, friction force.

    Evaluation of Retinal Nerve Fiber Layer Thickness in Patients with Multiple Sclerosis

    Get PDF
    Background: Multiple sclerosis (MS) is a neurodegenerative disease, and is considered a chronic inflammatory disease. Retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in MS.Objective: The aim of the present study was to assess the role of optical coherence tomography (OCT) in detecting RNFL in MS patients without history of optic neuritis and to correlate with disease duration and disease disability. Patients and methods: Case-control study included 34 patients with clinically definite relapsing remitting multiple sclerosis (RRMS) and 34 age- and sex-matched individuals (other than MS) served as the controls. They were selected from the inpatients wards and Outpatients Clinic of Neurology Department, Zagazig University Hospitals. All patients were subjected to full history taking, clinical examination as well as laboratory and specific investigations. Results: The mean age was 34.56 ± 8.79 years in MS patients and 34.03 ± 8.79 years in controls. VEP 42.9% is with delay of p100 wave in bilateral eyes, and prolongal p100 laterary in bilateral eyes in 54.3%. There was a highly statistical significant difference between groups as regard RNFL average thickness and RNFL symmetry. Expanded disability status scale (EDSS) showed independently associated with RNFL.Conclusion: The thickness of the RNFL observed by OCT in MS patients is dramatically reduced when compared to controls, according to the current study. OCT is a valuable tool for determining the thickness of the RNFL in MS patients

    BACTERIAL PATHOGENS OF NOSOCOMIAL INFECTIONS IN ICUS AND THEIR ANTIBIOTICS RESISTANT PATTERN AT KING KHALID HOSPITAL IN AL-KHARJ/SAUDI ARABIA

    Get PDF
    Background:The intensive care unit [ICU] is considered as infection epicenter because vulnerable population of critically ill patients and use of different invasive devices. Consequently, the ICU population has one of the highest occurrence rates of nosocomial infections leading to an enormous impact on morbidity, hospital costs, and often survival. In addition, the increasing problem of antibiotic resistance loads the burden of nosocomial infection in the ICU. Constant and careful global monitoring for multidrug-resistant bacteria is needed to minimise the possibility of appearance and dissemination of new resistant isolates and to avoid complications in treatment choices. Methods:This study was carried out from March to June 2016 in King Khalid Hospital [Al-Kharj-KSA] to explore the multidrug-resistant bacteria, Extended Spectrum - lactamase bacteria [ESBLs] and the possibility of carbapenems resistant bacteria isolated from clinical samples of patients in the ICUs. A total of 317 different clinical samples were received for cultivation and antibiogram during the study period. Samples were cultivated on Blood agar, MacConkey agar, CLED, EMB agar and Mannitol salt agar. Gram stain, colony morphology and biochemical tests were done.The final identification results of the causative agents and its sensitivity profile were obtained by automated procedures "Phoenix 100/BD company". Minimum inhibitory concentration [MIC] results were interpreted according to Clinical and laboratory standard institute [CLSI] guidelines. Results:Out of 317 total samples processed during the study, significant growth was shown in 62 samples [19.5%]. Respiratory samples showed the highest rate of positive growth [40.3% out of 62] followed by urine [20.96% out of 62]. Fifty-seven isolates [91.94 %] were gram-negative and five isolates [8.06%] were gram-positive. K. pneumoniae was the most frequently isolated among Gram-negative with16 isolates [28%] followed by P. aeruginosa 12 [21%]. All isolates of P. aeruginosa, Acinetobacter spp., Providencia spp., Enterobacter spp., Citrobacter spp., Serratia spp. were MDR [100%] while five isolates [71.4%] of Proteus mirabilis, and 11 [69%] of K. pneumoniae were MDR. ESBLs were confirmed in 39 [83%] isolates out of 47 MDR gram-negatives; among them, 11[28.2%] were K. pneumoniae and10 [25.64%] isolates of P. aeruginosa. Resistance to carbapenems was detected in 23 [48.94%] isolates of MDR gram-negative bacteria; among them, 10 [43.48%] isolates of P. aeruginosa, and 6[26.1%] isolates each of Acinetobacter spp. and K. pneumoniae. Conclusion:Considerable efforts and regular evaluation of ESBL and carbapenems resistant bacteria are of great importance both in hospital and community to avoid the appearance of new bacterial isolates which may resist all clinically used antibiotics. Keywords: Nosocomial infection, MDR, ESBL, Carbapenems, Resistance, Bacteria

    Designing Efficient and Sustainable Predictions of Water Quality Indexes at the Regional Scale Using Machine Learning Algorithms

    Get PDF
    Water quality and scarcity are key topics considered by the Sustainable Development Goals (SDGs), institutions, policymakers and stakeholders to guarantee human safety, but also vital to protect natural ecosystems. However, conventional approaches to deciding the suitability of water for drinking purposes are often costly because multiple characteristics are required, notably in low-income countries. As a result, building right and trustworthy models is mandatory to correctly manage available groundwater resources. In this research, we propose to check multiple classification techniques such as Decision Trees (DT), K-Nearest Neighbors (KNN), Discriminants Analysis (DA), Support Vector Machine (SVM), and Ensemble Trees (ET) to design the best strategy allowing the forecast a Water Quality Index (WQI). To achieve this goal, an extended dataset characterized by water samples collected in a total of twelve municipalities of the Wilaya of Naâma in Algeria was considered. Among them, 151 samples were examined as training samples, and 18 were used to test and confirm the prediction model. Later, data samples were classified based on the WQI into four states: excellent water quality, good water quality, poor water quality, and very poor or unsafe water. The main results revealed that the SVM classifier obtained the highest forecast accuracy, with 95.4% of prediction accuracy when the data are standardized and 88.9% for the accuracy of the test samples. The results confirmed that the use of machine learning models are powerful tools for forecasting drinking water as larger scales to promote the design of efficient and sustainable water quality control and support decision-plans.This work is part of PRFU project N° E04N01CU450120220001. The authors gratefully acknowledge the support of the General Directorate of Scientific Research and Technological Development (DGRSDT) and to Taif University Researchers Supporting Project TURSP 2020/34, Taif University, Taif, Saudi Arabia

    Diagnosis of exudative pleural effusion using ultrasound guided versus medical thoracoscopic pleural biopsy

    Get PDF
    AbstractIntroductionMedical thoracoscopy increases the diagnostic yield in patients with non-diagnosed pleural effusion when thoracocentesis and closed pleural biopsy (CPB) are non-diagnostic. Chest ultrasound (US) is a very useful imaging method for pleural diseases and the technique of ultra sound-guided cutting biopsy with a tru-cut needle has been well described.Aim of the workThe aim of this work was to diagnose exudative pleural effusion using ultrasound guided versus medical thoracoscopic pleural biopsy.Subjects and methodsForty patients with, non-diagnosed exudative pleural effusion admitted to the chest department, Alexandria university hospital, were enrolled after obtaining informed consents. All patients were subjected to; full history taking, thorough clinical examination, laboratory investigations including prothrombin activity and INR, biochemical, pathological and microbiological evaluation of the pleural aspirate and radiological evaluation. Then the patients were divided (randomly) into 2 groups each containing 20 patients. Pleural biopsies were performed using medical rigid thoracoscopy on group 1 and ultrasound guided tru-cut pleural biopsy on group 2.ResultsThe mean age in-group I was 55.0±13.05years and in-group II was 52.60±17.77years. There was no statistically significant difference between the two groups regarding age, sex, smoking, marital status and past medical conditions. There was no statistically significant difference between the two groups regarding radiological findings. There was no statistically significant difference between the two groups regarding the pleural fluid analysis. There was no statistically significant difference between the two groups regarding the gross pleural findings. In group II non- specific pleurisy was found in 5 (25.0%) patients (by thoracoscopy 1 of them was finally diagnosed as metastatic deposits from adenocarcinoma of unknown primary, one was confirmed to be tuberculous pleurisy and the remaining 3 cases were confirmed to be non- specific pleurisy). As regards complications in-group I, local wound infection occurred in 1 (5.0%) patient, and empyema occurred in 1 (5.0%) patient. In-group II, local wound infection occurred in 1 (5.0%) patient, and empyema occurred in 1 (5.0%) patient.ConclusionIt is better to use thoracoscopy in cases of undiagnosed exudative pleural effusion presented with a sufficient amount of pleural fluid to avoid lung injury while inserting the trocar. Whereas, ultrasound guided tru-cut pleural biopsy may be used in cases of undiagnosed exudative pleural effusion presented with thickened pleura but with an insufficient amount of pleural fluid

    Evaluation of the level of Some Heavy Metals in Tobacco of Domestic and Imported Cigarette Brands Used in Iraq

    Get PDF
    Smoking-related diseases can be attributed to the inhalation of many different toxins, including heavy metals, which have a host of harmful health effects. The primary objective of this study was to determine whether local and imported cigarette brands used in Iraq , have they elevated levels of metals or not .Three metals Lead (Pb) , Cadmium (Cd) and Chromium(Cr) were determined in tobacco of seventeen brands of imported cigarettes commonly available in Iraq and three Iraqi domestic cigarettes , which were randomly taken from retail market in Baghdad by using flame atomic absorption spectrometry. The produced data of imported and local cigarette brands were discussed and compared together and with studies from elsewhere .The results obtained showed that mean concentrations of lead for all cigarette brands was 5.87 ?g/g dry weight (range 2.27-11,67 ?g/g) , cadmium 0.57?g/g dry weight (range 0.1-1.57 ?g/g) and chromium 3.77?g/g dry weight (range 0.0-11.21 ?g/g) ..There was a large variability in Pb, Cd and Cr content of samples of cigarettes. Pb concentration was the highest, followed by Cr while Cd was the lowest. The investigation confirmed that most of the Iraqi and imported cigarettes in Iraq are contaminated with Pb, Cd, and Cr and quantitatively their distribution is clearly above the safer limits of WHO
    corecore