Search results for: kidney functions and chronic renal failure

Authors: Rachid El Khoury

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Chronic pain is perhaps the most burdensome health issue facing the planet. Our understanding of the pathophysiology of chronic pain has increased substantially over the past 25 years, including but not limited to changes in the brain. However, we still do not know why chronic pain develops in some people and not in others. Most of the recent developments in pain science, that have direct relevance to clinical management, relate to our understanding of the role of the brain, the role of the immune system, or the role of cognitive and behavioral factors. Although the Biopsychosocial model of pain management was presented decades ago, the Bio-reductionist model remains, unfortunately, at the heart of many practices across professional and geographic boundaries. A large body of evidence shows that nociception is neither sufficient nor necessary for pain. Pain is a conscious experience that can certainly be, and often is, associated with nociception, however, always modulated by countless neurobiological, environmental, and cognitive factors. This study will clarify the current misconceptions of chronic pain concepts, and their misperceptions by clinicians. It will also attempt to bridge the considerable gap between what we already know on pain but somehow disregarded, the development in pain science, and clinical practice.

Keywords: chronic pain, nociception, biopsychosocial, neuroplasticity

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Authors: Melike Aydoğan, Dürdane Öztürk

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Let H(D) be the linear space of all analytic functions defined on the open unit disc. A log-harmonic mappings is a solution of the nonlinear elliptic partial differential equation where w(z) ∈ H(D) is second dilatation such that |w(z)| < 1 for all z ∈ D. The aim of this paper is to define some inequalities of starlike logharmonic functions of order α(0 ≤ α ≤ 1).

Keywords: starlike log-harmonic functions, univalent functions, distortion theorem

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Authors: B. E. Adeyanju, M. K. Bolade, V. N. Enijuigha

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This work examined the nutritional composition of maize-based snack (kango) fortified with kidney beans (Phaseolus vulgaris) and alligator pepper (Aframomum melegueta). The snack is essentially traditional food being consumed by all ages in the southwestern part of Nigeria. Three varieties of maize were obtained from the Institute of Agricultural Research and Training (IAR&T), Ibadan, Nigeria, namely: ART-98-SW06-W, Br 9943-DMR-SR-W and SUWAN-1-SR-Y. Flour blends were obtained using the Response Surface Methodology (RSM) which resulted in appropriate blending ratios of maize, kidney beans and alligator pepper. Kango was prepared by milling maize grain into flour; ingredients such as pepper, onion, salt and water were added to the maize flour, mixed together to make a slurry. The slurry was fried in hot groundnut oil at a temperature of 126°C for 8 minutes. The incorporation of kidney bean and alligator pepper in maize flour was observed to increase the water and oil absorption capacities of the resultant blends thereby giving 109.21 to 156.90 ml/mg and 110.68 to 136.67 ml/mg respectively for kango. The pasting properties of the maize flour blends were also enhanced due to the incorporation of kidney bean and alligator pepper. The peak viscosity of the flour blends ranged from 3.24 to 7.67 RVU. The incorporation of kidney bean and alligator pepper in the production of the snacks increased the protein contents from 9.63 to 16.37%. The mineral contents (sodium, potassium, calcium, magnesium, iron and zinc) of the snacks were equally increased due to the incorporation of kidney bean and alligator pepper. A general increase was observed for vitamin B1 (0.69- 1.25 mg/100g), B2 (0.09 - 0.46 mg/100g) and B3 (0.11 - 0.72 mg/100g) in the snacks due to the incorporation of kidney bean and alligator pepper. This research work showed that kango produced from the composited maize flour, kidney bean and alligator pepper had better functional properties and higher nutritional contents.

Keywords: functional properties, kango, nutritional composition, snack

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Authors: Jelena Vucicevic

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Reliability analysis represents a very important task in different areas of work. In any industry, this is crucial for maintenance, efficiency, safety and monetary costs. There are ways to calculate reliability, unreliability, failure density and failure rate. This paper will try to introduce another way of calculating reliability by using R statistical software. R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS. The R programming environment is a widely used open source system for statistical analysis and statistical programming. It includes thousands of functions for the implementation of both standard and new statistical methods. R does not limit user only to operation related only to these functions. This program has many benefits over other similar programs: it is free and, as an open source, constantly updated; it has built-in help system; the R language is easy to extend with user-written functions. The significance of the work is calculation of time to failure or reliability in a new way, using statistic. Another advantage of this calculation is that there is no need for technical details and it can be implemented in any part for which we need to know time to fail in order to have appropriate maintenance, but also to maximize usage and minimize costs. In this case, calculations have been made on diesel generator fans but the same principle can be applied to any other part. The data for this paper came from a field engineering study of the time to failure of diesel generator fans. The ultimate goal was to decide whether or not to replace the working fans with a higher quality fan to prevent future failures. Seventy generators were studied. For each one, the number of hours of running time from its first being put into service until fan failure or until the end of the study (whichever came first) was recorded. Dataset consists of two variables: hours and status. Hours show the time of each fan working and status shows the event: 1- failed, 0- censored data. Censored data represent cases when we cannot track the specific case, so it could fail or success. Gaining the result by using R was easy and quick. The program will take into consideration censored data and include this into the results. This is not so easy in hand calculation. For the purpose of the paper results from R program have been compared to hand calculations in two different cases: censored data taken as a failure and censored data taken as a success. In all three cases, results are significantly different. If user decides to use the R for further calculations, it will give more precise results with work on censored data than the hand calculation.

Keywords: censored data, R statistical software, reliability analysis, time to failure

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Authors: Alicia C. Sanchez

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This paper investigates the implementation of RAFU functions (radical functions) in robotics and automation. Specifically, the main goal is to show how these functions may be useful in lane-keeping control and the lateral control of autonomous machines, vehicles, robots or the like. From the knowledge of several points of a certain route, the RAFU functions are used to achieve the lateral control purpose and maintain the lane-keeping errors within the fixed limits. The stability that these functions provide, their ease of approaching any continuous trajectory and the control of the possible error made on the approximation may be useful in practice.

Keywords: automatic navigation control, lateral control, lane-keeping control, RAFU approximation

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Authors: Joon Hock Yeo, Munirah Ismail

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Chronic venous insufficiency is a condition where the venous wall or venous valves fail to operate properly. As such, it is difficult for the blood to return from the lower extremities back to the heart. Chronic venous insufficiency affects many people worldwide. In last decade, there have been many new and innovative designs of prosthetic venous valves to replace the malfunction native venous valves. However, thus far, to the authors’ knowledge, there is no successful prosthetic venous valve. In this project, we have developed a venous valve which could operate under low pressure. While further testing is warranted, this unique valve could potentially alleviate problems associated with chronic venous insufficiency.

Keywords: prosthetic venous valve, bi-leaflet valve, chronic venous insufficiency, valve hemodynamics

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Authors: Khaled. M.Benelhaj, Moada Elbadary

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The present investigation is carried out to evaluate the effect of aqueous extract of Arbutus Pavarii (Shemari) Libyan medical plant on ethylene glycol(EG) induce lithiasis in adult male albino rats. The lithiasis was induced to rats by oral administration of EG (0.75 w/v%) for 21 days(group 1). Aqueous extract of Shemari (200 mg/kg) was given orally from 1st day for preventive regimen (group 2) and from day 21st up to 42nd day for curative regimen (group 3). The results indicated that the EG elevated the urinary ionic of calcium, oxalates and inorganic phosphate. The Shemari significantly (P<0.01) reduced the levels of these ions. The histopathological findings showed that EG caused marked pathological changes in renal cortex; necrosis of glomerular tufts; mildy thickened bowman’s capsule and coagulative necrosis of large number of convoluted tubules. However, the histological changes in preventive regimen group 2 showed the same changes observed in group 1, but milder in severity and less in frequency. It conclude that Shemari do reduce the urinary ionic levels of calcium, oxalates and inorganic phosphate but failed to prevent complete deterioration effects of EG on kidney structures.

Keywords: EG, shamari, kidney stone, Libyan medical plant, glycol, oxalates

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Authors: A. Gharaei, R. Karami

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Rutilus frisii Kutum was exposed to various concentrations of mercuric chloride in water to determine its acute toxicity and bioaccumulation. We carried out ten treatments with three replicates and one control for each of the chemicals using the static O. E. C. D. method in 55-liter-tanks each containing 14 fingerlings. During the experiments, the average pH was recorded as 7.8, total hardness was measured to be 255 mg/l, the average water temperature was 27±1 degrees centigrade and dissolved oxygen was 7.2 mg/l. Mean LC50 values of Hgcl2 for juvenile R. frisii kutum with mean weight 1±0.2 gr were 0.102 and 0.86 mgHg/l at 24h and 96h, respectively. The bioaccumulation values during 24h in tissue, kidney, and gill were 1.55, 16.1, and 22.7 mgHg/l, respectively. So, these values during 96h were 2.8, 16.8, and 26.65 mgHg/l, respectively. The bioconcentration factors in tissue, kidney, and gill during 24h were 14.75, 153.39, and 216.11 and so during 96h were 33.8, 198.1, and 313.5 times. These results show that bioaccumulation was highest in the gill and then kidney and tissue, respectively. This study suggested that between mercury concentrations of water with bioaccumulation in tissue more than kidney and gill.

Keywords: HgCl2, LC5096h, bioaccumulation, Rutilus frisii Kutum, Caspian Sea

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Authors: Roham Rafiee, Hadi Hesamsadat

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In this study, a parametric finite element modeling is developed to analyze failure modes of FRP pipes subjected to internal pressure. First-ply failure pressure and functional failure pressure was determined by a progressive damage modeling and then it is validated using experimental observations. The influence of both winding angle and fiber volume fraction is studied on the functional failure of FRP pipes and it corresponding pressure. It is observed that despite the fact that increasing fiber volume fraction will enhance the mechanical properties, it will be resulted in lower values for functional failure pressure. This shortcoming can be compensated by modifying the winding angle in angle plies of pipe wall structure.

Keywords: composite pipe, functional failure, progressive modeling, winding angle

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Authors: Orestis Kasinopoulos, Maria Karekla, Vasilis Vasiliou, Evangelos Karademas

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Acceptance and Commitment Therapy (ACT) is an empirically supported intervention for treating Chronic Pain Patients, yet its effectiveness for some chronic conditions or when adapted to other languages, has not been explored. An ACT group intervention was designed to explore the effectiveness of treating a Greek speaking heterogeneous sample of Chronic Pain patients with the aim of increasing quality of life, acceptance of pain and functionality. Sixty-nine patients were assessed and randomly assigned to an ACT or control group (relaxation techniques) for eight, 90-minute, sessions. Results are currently being analysed and follow-ups (6 and 12 month) are being completed. Low adherence rates and high attrition rates observed in the study, however point to the direction of future modified interventions. Such modifications may include web-based and smartphone interventions and their benefits in being implemented in chronic pain patients.

Keywords: chronic pain, ACT, internet-delivered, digitalised intervention, adherence, attrition

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Authors: Harini Chakkera

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Background: Inpatient hyperglycemia is an established independent risk factor among several patient cohorts with hospital readmission. This has not been studied after kidney transplantation. Nearly one-third of patients who have undergone a kidney transplant reportedly experience 30-day readmission. Methods: Data on first-time solitary kidney transplantations were retrieved between September 2015 to December 2018. Information was linked to the electronic health record to determine a diagnosis of diabetes mellitus and extract glucometeric and insulin therapy data. Univariate logistic regression analysis and the XGBoost algorithm were used to predict 30-day readmission. We report the average performance of the models on the testing set on five bootstrapped partitions of the data to ensure statistical significance. Results: The cohort included 1036 patients who received kidney transplantation, and 224 (22%) experienced 30-day readmission. The machine learning algorithm was able to predict 30-day readmission with an average AUC of 77.3% (95% CI 75.30-79.3%). We observed statistically significant differences in the presence of pretransplant diabetes, inpatient-hyperglycemia, inpatient-hypoglycemia, and minimum and maximum glucose values among those with higher 30-day readmission rates. The XGBoost model identified the index admission length of stay, presence of hyper- and hypoglycemia and recipient and donor BMI values as the most predictive risk factors of 30-day readmission. Additionally, significant variations in the therapeutic management of blood glucose by providers were observed. Conclusions: Suboptimal glucose metrics during hospitalization after kidney transplantation is associated with an increased risk for 30-day hospital readmission. Optimizing the hospital blood glucose management, a modifiable factor, after kidney transplantation may reduce the risk of 30-day readmission.

Keywords: kidney, transplant, diabetes, insulin

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Authors: Rashidah Omar, Suzeini Abdul Halim, Aini Janteng

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The coefficients estimate problem for Taylor-Maclaurin series is still an open problem especially for a function in the subclass of bi-univalent functions. A function f ϵ A is said to be bi-univalent in the open unit disk D if both f and f^-1 are univalent in D. The symbol A denotes the class of all analytic functions f in D and it is normalized by the conditions f(0) = f’(0) – 1=0. The class of bi-univalent is denoted by  The subordination concept is used in determining second and third Taylor-Maclaurin coefficients. The upper bound for second and third coefficients is estimated for functions in the subclasses of bi-univalent functions which are subordinated to the function φ. An analytic function f is subordinate to an analytic function g if there is an analytic function w defined on D with w(0) = 0 and |w(z)| < 1 satisfying f(z) = g[w(z)]. In this paper, two subclasses of bi-univalent functions associated with Hohlov operator are introduced. The bound for second and third coefficients of functions in these subclasses is determined using subordination. The findings would generalize the previous related works of several earlier authors.

Keywords: analytic functions, bi-univalent functions, Hohlov operator, subordination

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Authors: Arthi Ganapathy, Arithra Banerjee, Saroj Kaler

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Abdominal aorta is the sole purveyor of all organs in the abdomen. Anomalies of its main trunk or its branches are to be meticulously observed as it effects the perfusion of an organ. Varying patterns of the testicular artery is one of them. The origin and course of testicular arteries have to be identified carefully during various surgical procedures like renal transplant, intra abdominal surgeries and even in orthopedic surgery like spine surgery. With the advent of new intra-abdominal therapeutic and diagnostic techniques, the anatomy of testicular arteries has assumed much more significance. Though the variations of the testicular vein are well documented, the variations of the testicular artery are not so frequent in incidence. We report a case of the bilateral aberrant origin of the testicular artery from polar renal arteries. We also discuss its developmental basis. Such anomalies if left unnoticed will lead to serious intraoperative complications during procedures on retroperitoneal organs. Any damage to testicular arteries will compromise the function of the gonads.

Keywords: cadaver, gonadal, renal, surgery

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Authors: Kristina De Milt, Nicole Huang, Jihye Park

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Opioids have been a mainstay of the treatment of chronic pain, but their overprescription and misuse have led to an opioid epidemic. Recently, as an attempt to decrease the number of opioids prescribed, the use of cannabinoid therapy has become an increasingly popular adjunctive chronic pain management choice among providers. This review of literature investigates the effects of adjunctive cannabinoids to opioids in the management of chronic pain. The nine articles are included in the literature review range from observational studies to meta-analyses published in the year 2016 and after. A majority of the studies showed a decrease in the need for opioids after adjunctive cannabinoids were introduced and, in some instances, the cessation of opioid consumption. More high-quality evidence is needed to further support this stance and providers should weigh the benefits and risks of adjunctive cannabinoids according to the clinical picture.

Keywords: cannabis, chronic pain, opioids, pain management

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Authors: Binaya Tamang, Buddhi R. Pokharel, Narayan Gautam, Puspa R. Dhakal, Yuresh Twayana

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Background and Objective: Microalbuminuria is often regarded as a sign of end-organ damage due to hypertension, with an increased risk for renal diseases. The present study was designed to find the prevalence of microalbuminuria in hypertensive patients by determining albumin creatinine ratio (ACR) and the association of ACR and microalbuminuria status with different stages and duration of hypertension (HTN). Also, to establish the correlation of systolic and diastolic blood pressure (SBP and DBP) with various parameters viz; ACR, urinary microalbumin (UMA), estimated glomerular filtration rate (eGFR), urinary creatinine (Ucreat), serum creatinine (Screat), and find out their significance among HTN and ACR status. Materials and Methods: A hospital-based cross-sectional study was conducted in the Department of Biochemistry in collaboration with the Department of Internal Medicine, UCMS, Bhairahawa, Nepal from April 2019 to September 2019 after obtaining ethical approval from institutional review committee (IRC), UCMS. A total of 120 hypertensive patients were enrolled whose blood, and spot urine samples were taken. eGFR was calculated by using Cockcroft-Gault formula after determining Screat while ACR was calculated after measuring Ucreat and UMA from the spot urine sample. Creatinine was estimated from modified jaffes’ reaction, whereas urinary micro albumin was done by Mispa i3 analyzer. Data were analyzed by using SPSS. 20 using p-value ≤ 0.05 as statistically significant. Results: In our study, the highest enrolled were grade II HTN (36.7%) followed by normal (33.3%), grade I (20.8%) and grade III (9.2%). Evaluating the ACR status, 19.2% were microalbuminuria, and the rest were normal. Though the ACR status (normal and microalbuminuria) was not statistically significant with HTN status (P=0.860) and the duration of HTN status (P=0.165), 5 (45.5%) out of 11 grade III HTN were microalbuminuria and the prevalence was also higher for longer duration .i.e., more than 10 years. In microalbuminuria, both the SBP (p=0.023, r=0.471) and DBP (P=0.034, r= 0.444) were strongly and positively correlated with Screat, in contrast to eGFR, which was negatively but weakly correlated. With the significant difference between the HTN group, the mean ACR (P=0.047) and UMA (P=0.02) were found to be highest among grade III patients, i.e., 84.3 ± 113.3 mg/gm. and 88.4 ± 83.9 mg/l respectively. The mean eGFR (64.2 ± 24.8 vs 77.2 ± 18.1 ml/min) was considerably lower in microalbuminuria ( p=0.026) than the normal in contrast to the SBP (160 ± 33.7 vs. 146.6 ± 19.5 mm of Hg) which was significantly higher (P=0.008). Among the different BMI category, the mean ACR was found to be significantly different (P= 0.01) with the highest value in underweight (115.2 ± 51.5 mg/gm.) and lowest in overweight (31.8 ± 4.3 mg/gm.). Conclusion: The study recommends that the microalbuminuria can be a very useful and imperative predictor of deranged kidney functions in hypertensive patients. The high value of ACR and UMA in hypertensive patients along with significant increased Screat, SBP whereas decreased eGFR in microalbuminuria patients explicitly supports the above statement.

Keywords: albumin creatinine ratio, hypertension, microalbuminuria, renal disease

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Authors: İbrahim Aktaş, Árpád Baricz

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In this paper, the radii of star likeness of the Jackson and Hahn-Exton q-Bessel functions are considered, and for each of them three different normalizations is applied. By applying Euler-Rayleigh inequalities for the first positive zeros of these functions tight lower, and upper bounds for the radii of starlikeness of these functions are obtained. The Laguerre-Pólya class of real entire functions plays an important role in this study. In particular, we obtain some new bounds for the first positive zero of the derivative of the classical Bessel function of the first kind.

Keywords: bessel function, lommel function, radius of starlikeness and convexity, Struve function

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Authors: S. W. Liu, J. H. Lv, W. Z. Wang

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In recent years, the failure accidents in petrochemical industry have been frequent, and have posed great security problems in personnel and property. The improvement of petrochemical safety is highly requested in order to prevent re-occurrence of severe accident. This study focuses on surveying the failure cases occurred in petrochemical field, which were extracted from journals of engineering failure, including engineering failure analysis and case studies in engineering failure analysis. The relation of failure mode, failure mechanism, type of components, and type of materials was analyzed in this study. And the analytical results showed that failures occurred more frequently in vessels and piping among the petrochemical equipment. Moreover, equipment made of carbon steel and stainless steel accounts for the majority of failures compared to other materials. This may be related to the application of the equipment and the performance of the material. In addition, corrosion failures were the largest in number of occurrence in the failure of petrochemical equipment, in which stress corrosion cracking accounts for a large proportion. This may have a lot to do with the service environment of the petrochemical equipment. Therefore, it can be concluded that the corrosion prevention of petrochemical equipment is particularly important.

Keywords: cases analysis, corrosion, failure, petrochemical industry

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Authors: V. V. Singh

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We have studied the reliability measures of a system, which consists of two subsystems i.e. subsystem-1 and subsystem-2 in series configuration under different types of failure. The subsystem-1 has three identical units in parallel configuration and operating under 2-out-of-3: G policy and connected to subsystem-2 in series configuration. Each subsystem has different types of failure and repair rates. An important cause for failure of system is unsuitability of the environmental conditions, like overheating, weather conditions, heavy rainfall, storm etc. The environmental failure is taken into account in the proposed repairable system. Supplementary variable technique is used to study of system and some traditional measures such as; availability, reliability, MTTF and profit function are obtained for different values of parameters. In the proposed model, some particular cases of failure rates are explicitly studied.

Keywords: environmental failure, human failure, availability, MTTF, reliability, profit analysis, Gumbel-Hougaard family copula

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Authors: Altoumi Alndalusi

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High-temperature hydrogen attack (HTHA) failure is the common phenomena at elevated temperature in hydrogen environment in oil and gas field. The failure occurred once after four years at the internal surface of Platforming elbow. Both visual and microscopic examinations revealed that the failure was initiated due to blistering forming followed by large cracking at the inner surface. Crack morphology showed that the crack depth was about 50% of material wall thickness and its behavior generally was intergranular. This study concluded that the main reason led to failure due to incorrect material selection comparing to the platforming conditions.

Keywords: decarburization, failure, heat affected zone, morphology, partial pressure, plate form

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Authors: Watchareewan Thongsaard, Ratirat Sangpayap, Maneekarn Namsa-Aid

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Thunbergia laurifolia Linn. (TL) is a herbal medicine which has been used as an antidote for several poisonous agents including insecticides and as a component of a mixture of crude extracts to treat drug addicted patients. The aim of this study is to examine the level of dopamine in nucleus accumbens after chronic pre-administration of TL in ethanol addicted rats. Male Wistar rats weigh 200-250 g received TL methanol extract (200mg/kg, orally) 60 minutes before 20% ethanol (1 g/kg, i.p.) for 30 days. The nucleus accumbens was removed and tested for dopamine by HPLC-ECD. The level of dopamine was significantly increased by chronic ethanol administration, whereas the chronic TL extract administration did not cause a difference in dopamine level when compared to control. Moreover, the pre-treatment of TL extract before ethanol significantly reduced the dopamine level in nucleus accumbens to normal level when compared with chronic ethanol administration alone. These results suggested that the increase in dopamine level in the nucleus accumbens by chronic ethanol administration is the cause of ethanol addiction, and this effect is prevented by chronic TL pre-administration. Furthermore, chronic TL extract administration alone did not cause the changes in dopamine level in the nucleus accumbens, indicating that TL itself did not cause addiction.

Keywords: Thunbergia laurifolia Linn., alcohol addiction, dopamine, nucleus accumbens

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Authors: Aydin Azizi, Ahmed Al. Azizi

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Mechanical seals are essential components in centrifugal pumps since they help in controlling leaking out of the liquid that is pumped under pressure. Unlike the common types of packaging, mechanical seals are highly efficient and they reduce leakage by a great extent. However, all multiphase mechanical seals leak and they are subject to failure. Some of the factors that have been recognized to their failure include excessive heating, open seal faces, as well as environment related factors that trigger failure of the materials used to manufacture seals. The proposed research study will explore the failure of multiphase mechanical seal in centrifugal pumps. The objective of the study includes how to reduce the failure in multiphase mechanical seals and to make them more efficient.

Keywords: mechanical seals, centrifugal pumps, multi phase failure, excessive heating

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Authors: Agnieszka Dudzik

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The problem of correlation between random variables in the structural reliability analysis has been extensively discussed in literature on the subject. The cases taken under consideration were usually related to correlation between random variables from one side of ultimate limit state: correlation between particular loads applied on structure or correlation between resistance of particular members of a structure as a system. It has been proved that positive correlation between these random variables reduces the reliability of structure and increases the probability of failure. In the paper, the problem of correlation between random variables from both side of the limit state equation will be taken under consideration. The simplest case where these random variables are of the normal distributions will be concerned. The case when a degree of that correlation is described by the covariance or the coefficient of correlation will be used. Special attention will be paid on questions: how much that correlation changes the reliability level and can it be ignored. In reliability analysis will be used well-known methods for assessment of the failure probability: based on the Hasofer-Lind reliability index and Monte Carlo method adapted to the problem of correlation. The main purpose of this work will be a presentation how correlation of random variables influence on reliability index of steel bar structures. Structural design parameters will be defined as deterministic values and random variables. The latter will be correlated. The criterion of structural failure will be expressed by limit functions related to the ultimate and serviceability limit state. In the description of random variables will be used only for the normal distribution. Sensitivity of reliability index to the random variables will be defined. If the reliability index sensitivity due to the random variable X will be low when compared with other variables, it can be stated that the impact of this variable on failure probability is small. Therefore, in successive computations, it can be treated as a deterministic parameter. Sensitivity analysis leads to simplify the description of the mathematical model, determine the new limit functions and values of the Hasofer-Lind reliability index. In the examples, the NUMPRESS software will be used in the reliability analysis.

Keywords: correlation of random variables, reliability index, sensitivity of reliability index, steel structure

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Authors: Oya Umit Yemisci, Nur Saracgil Cosar, Tubanur Ozturk Sisman, Selin Ozen

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Chronic autoimmune thyroiditis (AIT) may result in a wide spectrum of reversible abnormalities in the neuromuscular function. Usually, proximal muscle-related symptoms and neuropathic findings such as mild axonal peripheral neuropathy have been reported. Sympathetic skin responses are useful in evaluating sudomotor activity of the unmyelinated sympathetic fibers of the autonomic nervous system. Neurocognitive impairment may also be a prominent feature of hypothyroidism, particularly in elderly patients. Electromyographic reaction times as a highly sensitive parameter provides. Objective data concerning cognitive and motor functions. The aim of this study was to evaluate peripheral nerve functions, sympathetic skin response and electroneuromyographic (ENMG) reaction times in euthyroid and subclinically hypothyroid patients with a diagnosis of AIT and compare to those of a control group. Thirty-five euthyroid, 19 patients with subclinical hypothyroidism and 35 age and sex-matched healthy subjects were included in the study. Motor and sensory nerve conduction studies, sympathetic skin responses recorded from hand and foot by stimulating contralateral median nerve and simple reaction times by stimulating tibial nerve and recording from extensor indicis proprius muscle were performed to all patients and control group. Only median nerve sensory conduction velocities of the forearm were slower in patients with AIT compared to the control group (p=0.019). Otherwise, nerve conduction studies and sympathetic skin responses showed no significant difference between the patients and the control group. However, reaction times were shorter in the healthy subjects compared to AIT patients. Prolongation in the reaction times may be considered as a parameter reflecting the alterations in the cognitive functions related to the primary disease process in AIT. Combining sympathetic skin responses with more quantitative tests such as cardiovascular tests and sudomotor axon reflex testing may allow us to determine higher rates of involvement of the autonomic nervous system in AIT.

Keywords: sympathetic skin response, simple reaction time, chronic autoimmune thyroiditis

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Authors: Kwok W. Mui, Ling T. Wong, Nai K. K. Fong

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Chronic obstructive pulmonary disease (COPD) is the fifth leading cause of death in Hong Kong. Investigators are eager to explore the environmental risk factors for COPD such as air pollution and occupational exposure. Through a cross-sectional survey, this study investigates the impact of air quality to the quality of life of patients with the COPD in terms of the scores of the (Chinese) chronic respiratory questionnaire (CCRQ) and the measurements of indoor air quality (IAQ) and Moser’s activities of daily living (ADL). Strong relationships between a number of indoor/outdoor environmental parameters were found and CRQ sub-scores for patients of COPD and thus indoor air pollutants must be monitored for future studies related to QOL for patients with COPD.

Keywords: chronic obstructive pulmonary disease (COPD), indoor air pollutants, quality of life, chronic respiratory questionnaire (CRQ)

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Authors: Eduardo C. Guardia, Jose W. M. Lima, Afonso H. M. Santos

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This paper presents a nonparametric method to obtain the hazard rate “Bathtub curve” for power system components. The model is a mixture of the three known phases of a component life, the decreasing failure rate (DFR), the constant failure rate (CFR) and the increasing failure rate (IFR) represented by three parametric Weibull models. The parameters are obtained from a simultaneous fitting process of the model to the Kernel nonparametric hazard rate curve. From the Weibull parameters and failure rate curves the useful lifetime and the characteristic lifetime were defined. To demonstrate the model the historic time-to-failure of distribution transformers were used as an example. The resulted “Bathtub curve” shows the failure rate for the equipment lifetime which can be applied in economic and replacement decision models.

Keywords: bathtub curve, failure analysis, lifetime estimation, parameter estimation, Weibull distribution

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Authors: Tulin Coskun

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We investigate the approximation of analytic functions of several variables in polydisc by the sequences of linear k-positive operators in Gadjiev sence. The approximation of analytic functions of complex variable by linear k-positive operators was tackled, and k-positive operators and formulated theorems of Korovkin's type for these operators in the space of analytic functions on the unit disc were introduced in the past. Recently, very general results on convergence of the sequences of linear k-positive operators on a simply connected bounded domain within the space of analytic functions were proved. In this presentation, we extend some of these results to the approximation of analytic functions of several complex variables by sequences of linear k-positive operators.

Keywords: analytic functions, approximation of analytic functions, Linear k-positive operators, Korovkin type theorems

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Authors: Stephanie Cornish

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The use of synthetic dermal templates, also known as dermal matrices, such as PolyNovo® Biodegradable Temporising Matrix (BTM), has been well established in the reconstruction of acute wounds with a full thickness defect of the skin. Its use has become common place in the treatment of full thickness burns and is not unfamiliar in the realm of necrotising fasciitis, free flap donor site reconstruction, and the management of acute traumatic wounds. However, the use of dermal templates for more chronic wounds is rare. The authors present the successful use of BTM in the reconstruction of a chronic scalp wound following the excision of a malignancy and multiple previous failed attempts at repair, thus demonstrating the potential for an increased scope of use.

Keywords: dermal template, BTM, chronic, scalp wound, reconstruction

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Authors: V. V. Singh

Abstract:

In this paper we have focused on the study of a Linux operating system connected in a LAN (local area network). We have considered two different topologies STAR topology (subsystem-1) and BUS topology (subsystem-2) which are placed at two different places and connected to a server through a hub. In both topologies BUS topology and STAR topology, we have assumed 'n' clients. The system has two types of failure partial failure and complete failure. Further the partial failure has been categorized as minor partial failure and major partial failure. It is assumed that minor partial failure degrades the subsystem and the major partial failure brings the subsystem to break down mode. The system can completely failed due to failure of server hacking and blocking etc. The system is studied by supplementary variable technique and Laplace transform by taking different types of failure and two types of repairs. The various measures of reliability like availability of system, MTTF, profit function for different parametric values has been discussed.

Keywords: star topology, bus topology, hacking, blocking, linux operating system, Gumbel-Hougaard family copula, supplementary variable

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Authors: Balakumar Pitchai, Xiang Llan Ang, Sunil Prajapati, Varatharajan Rajavel, Sundram Karupiah, Mohd Baidi Bahari

Abstract:

The study examined the pretreatment and post-treatment effects of low-doses of fenofibrate and rosuvastatin in gentamicin-induced acute nephrotoxicity in rats. Gentamicin (100 mg/kg/day, i.p.) was administered to rats for 8 days. In the pretreatment protocol, low-dose fenofibrate (30 mg/kg/day, p.o.) or low-dose rosuvastatin (2 mg/kg/day, p.o.) treatments were started a day before the administration of gentamicin and continued for 8 days. In the post-treatment protocol, rats administered gentamicin were treated with low-dose fenofibrate (30 mg/kg/day, p.o.) or low-dose rosuvastatin (2 mg/kg/day, p.o.) for 6 days after the completion of 8 days protocol of gentamicin administration. Gentamicin-associated acute nephrotoxicity in rats was assessed in terms of biochemical analysis and renal histopathological studies. Gentamicin-administered rats showed marked renal functional changes as assessed in terms of a significant increase in serum creatinine and urea levels as compared to normal rats. The renal dysfunction noted in gentamicin administered rats was accompanied with elevated serum uric acid level as compared to normal rats while there was no significant change in lipid profile. Low-dose fenofibrate pretreatment in gentamicin-administered rats afforded a significant renal functional improvements and renoprotection while its post-treatment showed no significant renoprotection. On the other hand, pretreatment with low-dose rosuvastatin partially reduced gentamicin-induced increase in serum creatinine level, but its post-treatment did not afford renal functional improvements in gentamicin-administered rats. However, all pre and post-treatments with low-doses of fenofibrate or rosuvastatin significantly reduced the elevated serum uric acid concentration in gentamicin-administered rats. Renal histopathological analysis showed a discernible incidence of acute tubular necrosis in gentamicin-administered rats which were markedly reduced by low-dose fenofibrate or low-dose rosuvastatin pretreatments; but, not by their post-treatments. In conclusion, low-dose fenofibrate pretreatment considerably prevented gentamicin-induced acute tubular necrosis and renal functional abnormalities in rats while its post-treatment resulted in no significant renoprotective action. In spite of effective prevention of gentamicin-induced acute tubular necrosis, the pretreatment with low-dose rosuvastatin had only a partial and fractional protection on renal functional abnormalities. The post-treatment with low-dose rosuvastatin was ineffective in affording a renoprotection in gentamicin-administered rats.

Keywords: gentamicin-nephrotoxicity, low-dose fenofibrate, low-dose rosuvastatin, renoprotection

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Authors: Alakija Temitope Olufunmilayo, Akinyemi, Yagba Joy

Abstract:

Hepatitis is the inflammation of the liver tissue that can cause whiteness of the eyes (Jaundice), lack of appetite, vomiting, tiredness, abdominal pain, diarrhea. Hepatitis is acute if it resolves within 6 months and chronic if it last longer than 6 months. Acute hepatitis can resolve on its own, lead to chronic hepatitis or rarely result in acute liver failure. Chronic hepatitis may lead to scarring of the liver (Cirrhosis), liver failure and liver cancer. Modelling Hepatitis B may become necessary in order to reduce its spread. So, dynamic SIR model can be used. This model consists of a system of three coupled non-linear ordinary differential equation which does not have an explicit formula solution. It is an epidemiological model used to predict the dynamics of infectious disease by categorizing the population into three possible compartments. In this study, a five-compartment dynamic model of Hepatitis B disease was proposed and developed by adding control measure of sensitizing the public called awareness. All the mathematical and statistical formulation of the model, especially the general equilibrium of the model, was derived, including the nonlinear least square estimators. The initial parameters of the model were derived using nonlinear least square embedded in R code. The result study shows that the proportion of Hepatitis B patient in the study population is 1.4 per 1,000,000 populations. The estimated Hepatitis B induced death rate is 0.0108, meaning that 1.08% of the infected individuals die of the disease. The reproduction number of Hepatitis B diseases in Nigeria is 6.0, meaning that one individual can infect more than 6.0 people. The effect of sensitizing the public on the basic reproduction number is significant as the reproduction number is reduced. The study therefore recommends that programme should be designed by government and non-governmental organization to sensitize the entire Nigeria population in order to reduce cases of Hepatitis B disease among the citizens.

Keywords: hepatitis B, modelling, non-linear ordinary differential equation, sihar model, sensitization

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