1,978 research outputs found

    Volume 6 Paper C036 Laser Optical Interferometry in Electrochemistry and Corrosion: Fundamentals and Applications

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    ABSTRACT In the present investigation, holographic interferometry was utilized for the first time to determine the rate change of the number of the fringe evolutions during the corrosion test of carbon steel in blank seawater and with seawater with different concentrations of a corrosion inhibitor. In other words, the anodic dissolution behaviors (corrosion) of the carbon steel were determined simultaneously by holographic interferometry, an electromagnetic method, and by the Electrochemical Impedance (E.I) spectroscopy, an electronic method. So, the abrupt rate change of the number of the fringe evolutions during corrosion test, (E.I) spectroscopy, of the carbon steel is called electrochemical emission-spectroscopy. The corrosion process of the steel samples was carried out in blank seawater and seawater with different concentrations, 5-20ppm, of RA-41 corrosion inhibitor using the E.I spectroscopy method, at room temperature. The electrochemical emission spectra of the carbon steel in different solutions represent a detail picture of the rate change of the anodic dissolution of the steel throughout the corrosion processes. Furthermore, the optical interferometry data of the carbon steel were compared to the data, which obtained from the E.I. spectroscopy. Consequently, holographic interferometric is found very useful for monitoring the anodic dissolution behaviors of metals, in which the number of the fringe evolutions of the steel samples can be determined in situ

    Anti-Nutritive Factors, Mineral Profile, In Vitro Gas Production and Fermentation Characteristics of Ten Browse Forage Leaves

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    The nutritive values of leaves from ten (10) different browse plants were analyzed using the in vitro gas production. Crude protein (CP) contents in the browses plants ranged from 114.90 to 173.90g kg-1 dry matter (DM). Ranges of 30.60 to 51.60g kg-1 DM were recorded for EE values for the eight browse plants. The NDF, ADF and ADL were 412.10 to 688.10, 211.60 to 265.60, and 88.30 to 140.30g kg-1 DM respectively. The values reported for anti-nutritive factors ranged from 0.08 to 0.39 for TCT, 0.31 to 0.71 for phenolics, 1.08 to 2.99 for Saponin, 4.58 to 8.00 for Oxalate, and 2.22 to 7.33 for phytate. The values reported for minerals showed significant differences (p<0.05) for all the macro minerals; this followed a similar pattern for the trace minerals except for cobalt and nickel. The in vitro gas production was highest (28.33ml / 200g DM) and lowest (3.66ml / 200g DM). The fermentation characteristics a, b, a+b, c, t, Y were highest at 3.67, 25.00, 28.33, 0.057, 18.00, and 11.33 respectively. All the gas production parameters differed significantly (P<0.05). Based on chemical composition and in vitro gas production, results show that the leaves of the browse forages have nutritive value and therefore, may serve as potential supplements for ruminants in Nigeria

    Clinical presentation of hypothyroidism: a study of 50 cases

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    Background: When the thyroid gland does not produce and release enough thyroid hormone into your circulation, it is known as hypothyroidism. Your metabolism becomes slower as a result. Hypothyroidism, also known as an underactive thyroid, can make you feel exhausted, put-on weight, and have trouble with cold weather. In utero, throughout infancy, during youth, or even during maturity, it may begin to develop. The frequency of unanticipated overt hypothyroidism varies from 1 to 18 cases per thousand persons when accompanied by biochemical and clinical symptoms of hypothyroidism. The aim of the study was to observe the various clinical presentations of hypothyroidismMethods: This cross-sectional observational case-based study was conducted at the institute of nuclear medicine, Dhaka medical college hospital, Dhaka, Bangladesh. The study duration was 6 months, from January 2005 to July 2005. A total of 50 patients attended at the study place during the study period who were biochemically hypothyroid were included in the study.Results: The age range of the patients was 13 months to 54 years with a mean age of 29.5 years in this series. The majority of the patients were between 20 to 49 years of age. Female comprises 80.0% in comparison to 20.0% of male cases of hypothyroidism. Spontaneous primary (idiopathic) hypothyroidism (90.0%), post-radioiodine therapy, and post-ablative hypothyroidism were the most important causes of hypothyroidism in this series. Most typical symptoms and signs of hypothyroidism were found in this study. The most common symptoms were generalized weakness, lethargy, slowness of activities, impairment of memory, loss of scalp hair, somnolence, dry skin, puffiness of the face, constipation, weight gain, hoarseness of voice, swelling of the body, decreased sweating and paraesthesia. Cases of idiopathic hypothyroidism and other types had similar symptoms. The mean duration of symptoms before medical consultation was 2.9 years. Dry and coarse skin topped the list of physical findings and was present in 60.0% of the cases. Other findings in order of frequency include goiter (56.0%), puffiness of the face (38.0%), cold and thick skin (44.0%), thick tongue (24.0%), peripheral edema (24.0%), Anemia (20.0%), pallor of the face (12.0%), bradycardia (08.0%), thick lips (4.0%), ascites (2.0%) and pericardial effusion (2.0%).Conclusions: Although in the present series a limited number of patients were included, it encompassed varieties of cases. Moreover, an attempt was made to evaluate the common presentation, age incidence, sex distribution, and laboratory status of hypothyroidism in our country, giving more emphasis on clinical findings

    Morphometric study of changes in GAD 65 expressing beta cell mass in the islets of langerhans in pregnant mice

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    INTRODUCTION: This study explored the adaptive changes in pancreatic islets by assessing the maternal pancreatic β-cell mass (PβCM), islets size, number, shape, distribution and vascularity using the anti-GAD65 Ab as a marker in pregnant mice. MATERIALS AND METHODS: Fourty female Swiss-Webster mice were randomly divided into two age matched groups of 20 animals each, pregnant and control (non-pregnant) groups. The pregnant mice were sacrificed at Day 19 of gestation and the control group was sacrificed 19 days after observation in the same environmental conditions. Specimens of pancreata were fixed in 10% formal-saline, and processed for light microscopy. Paraffin sections were stained with chromogen DAB. Image scope (APERIO) with Image J software was used for morphometric study. RESULTS: Islets cells showed specific reaction with GAD65 Ab. There was an increase in the cellularity and vascularity of the PβCM. A significant increase in the islets area of the pregnant group ranging between 32-723 μm2 in comparison with the control group that ranged between 5–210 μm2, the islet size and numbers also increased; there were numerous newly formed islets and coalescence of adjacent islets, positive reactivity of β-cells toward anti- GAD65 during pregnancy, the mean of positive granulation in PβCM in pregnant group was 8273.5±SE 831.35 while in control group was 34±SE 0.2. CONCLUSION: The changes for alteration in PβCM such as increase in cells number, size, positive anti-GAD65 reactivity and their vascularity during pregnancy is related to the adaptation for hormonal and nutritional demands of both foetus and mother

    A review of the use of terrestrial laser scanning application for change detection and deformation monitoring of structures

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    Change detection and deformation monitoring is an active area of research within the field of engineering surveying as well as overlapping areas such as structural and civil engineering. The application of Terrestrial Laser Scanning (TLS) techniques for change detection and deformation monitoring of concrete structures has increased over the years as illustrated in the past studies. This paper presents a review of literature on TLS application in the monitoring of structures and discusses registration and georeferencing of TLS point cloud data as a critical issue in the process chain of accurate deformation analysis. Past TLS research work has shown some trends in addressing issues such as accurate registration and georeferencing of the scans and the need of a stable reference frame, TLS error modelling and reduction, point cloud processing techniques for deformation analysis, scanner calibration issues and assessing the potential of TLS in detecting sub-centimetre and millimetre deformations. However, several issues are still open to investigation as far as TLS is concerned in change detection and deformation monitoring studies such as rigorous and efficient workflow methodology of point cloud processing for change detection and deformation analysis, incorporation of measurement geometry in deformation measurements of high-rise structures, design of data acquisition and quality assessment for precise measurements and modelling the environmental effects on the performance of laser scanning. Even though some studies have attempted to address these issues, some gaps exist as information is still limited. Some methods reviewed in the case studies have been applied in landslide monitoring and they seem promising to be applied in engineering surveying to monitor structures. Hence the proposal of a three-stage process model for deformation analysis is presented. Furthermore, with technological advancements new TLS instruments with better accuracy are being developed necessitating more research for precise measurements in the monitoring of structures

    Development of Photonic Crystal Fiber Based Gas/ Chemical Sensors

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    The development of highly-sensitive and miniaturized sensors that capable of real-time analytes detection is highly desirable. Nowadays, toxic or colorless gas detection, air pollution monitoring, harmful chemical, pressure, strain, humidity, and temperature sensors based on photonic crystal fiber (PCF) are increasing rapidly due to its compact structure, fast response and efficient light controlling capabilities. The propagating light through the PCF can be controlled by varying the structural parameters and core-cladding materials, as a result, evanescent field can be enhanced significantly which is the main component of the PCF based gas/chemical sensors. The aim of this chapter is to (1) describe the principle operation of PCF based gas/ chemical sensors, (2) discuss the important PCF properties for optical sensors, (3) extensively discuss the different types of microstructured optical fiber based gas/ chemical sensors, (4) study the effects of different core-cladding shapes, and fiber background materials on sensing performance, and (5) highlight the main challenges of PCF based gas/ chemical sensors and possible solutions

    The need for national medical licensing examination in Saudi Arabia

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    <p>Abstract</p> <p>Background</p> <p>Medical education in Saudi Arabia is facing multiple challenges, including the rapid increase in the number of medical schools over a short period of time, the influx of foreign medical graduates to work in Saudi Arabia, the award of scholarships to hundreds of students to study medicine in various countries, and the absence of published national guidelines for minimal acceptable competencies of a medical graduate.</p> <p>Discussion</p> <p>We are arguing for the need for a Saudi national medical licensing examination that consists of two parts: Part I (Written) which tests the basic science and clinical knowledge and Part II (Objective Structured Clinical Examination) which tests the clinical skills and attitudes. We propose this examination to be mandated as a licensure requirement for practicing medicine in Saudi Arabia.</p> <p>Conclusion</p> <p>The driving and hindering forces as well as the strengths and weaknesses of implementing the licensing examination are discussed in details in this debate.</p

    Neuropsychological patterns following lesions of the anterior insula in a series of forty neurosurgical patients

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    In the present study we investigated the effects of lesions affecting mainly the anterior insula in a series of 22 patients with lesions in the left hemisphere (LH), and 18 patients with lesions involving the right hemisphere (RH). The site of the lesion was established by performing an overlap of the probabilistic cytoarchitectonic maps of the posterior insula. Here we report the patients\u2019 neuropsychological profile and an analysis of their pre-surgical symptoms. We found that pre-operatory symptoms significantly differed in patients depending on whether the lesion affected the right or left insula and a strict parallelism between the patterns emerged in the pre-surgery symptoms analysis, and the patients\u2019 cognitive profile. In particular, we found that LH patients showed cognitive deficits. By contrast, the RH patients, with the exception of one case showing an impaired performance at the visuo-spatial planning test were within the normal range in performing all the tests. In addition, a sub-group of patients underwent to the post-surgery follow-up examination
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