198 research outputs found
The association between sleep and obesity and its impact on health and wellbeing
The focus of this thesis was to investigate, especially in the context of obesity, the interactions among sleep duration and quality, and adverse health outcomes. Three comprehensive studies are described in the thesis:
1. A cross-sectional epidemiological study examined factors that are associated with both short and long sleep duration among an older Chinese population, and also assessed whether there was a link between sleep duration and chronic conditions such as obesity, hypertension, and diabetes. This study showed that long sleep duration was associated with increased risk for obesity among women. Additionally, demographic, socio-economic, and medical conditions were associated with sleep duration. Identifying potential factors that affect sleep will inform future interventions for improving sleep with potential downstream effect on obesity and other chronic disorders.
2. A cross-sectional study of patients with extreme obesity indicated that the prevalence of sleep disturbance is high in this patient population. There was a positive association between sleep disturbance factors and depressive symptoms and quality of life among these individuals. The findings emphasise the importance of adequate assessment and treatment of sleep problems in this patient population.
3. A systematic review and meta-analysis assessed the effectiveness of lifestyle modification interventions on the treatment of obstructive sleep apnoea (OSA). Lifestyle interventions such as dietary and physical activity improved OSA parameters, but were insufficient to normalise them. The findings will inform the development of future interventions for OSA, and are likely to contribute to clinical guidelines for OSA management
Tremor Suppression in the Human Hand and Forearm
University of Technology Sydney. Faculty of Engineering and Information Technology.Tremor is a neurological disorder characterized by involuntary oscillations and poses a functional problem to a large number of patients. The most preferred description for tremor is an involuntary movement that is an approximately rhythmic and roughly sinusoidal movement. It results from a neurological disorder which can affect many daily activities. People who are affected by Parkinson’s diseases (PD) have tremor on their upper limb especially in the forearm and hand. Difficulties associated with tremor in patients with PD have motivated the researchers to work on developing various methods for tremor suppression. There is some medical and non-medical treatment for tremor reduction. Despite the considerable experience in tremor management, current treatment based on drugs or surgery does not achieve an effective reduction in 25 % of patients.
For such case, many researchers concentrated on finding non-medical treatments for tremor diminution. Active force control (AFC) or active vibration control (AVC) is one of the most famous non-medical methods for tremor suppression and control. Active vibration control is an alternate way to control and attenuate the vibration. In this method a counter force which is equal to the original vibration force but in the opposite direction is applied to the vibrating structure to supress the vibration. Finally, the vibration of structures will be stopped as two opposite forces cancel each other. The AFC method for tremor attenuation in the human forearm and hand is considered in this thesis. An AFC system is proposed which has a piezoelectric actuator and a classic proportional-derivative (PD) controller. Tremor behavior is investigated in three different models. The first model is a four degrees-of-freedom (4-DOF) biodynamic model of the human hand, which is the combination of mass-spring-damper system. The second model is a one degree-of-freedom (1-DOF) musculoskeletal model of the elbow joint with two links and one joint which includes two muscles, biceps, and triceps as the flexor and the extensor of the elbow joint. The third model is a three degrees-of-freedom (3-DOF) musculoskeletal model including wrist flexion-extension (FE), radial-ulnar deviation (RUD), and pronation supination (PS). The musculoskeletal model contains four muscles; extensor carpi radialis longus, extensor carpi ulnaris, flexor carpi ulnaris and flexor carpi radialis. First, simulation of the tremor generation in the model is performed and then the performance of the AFC system for suppressing tremor is investigated in all three models. A single piezoelectric actuator is embedded in the AFC system for controlling the behavior of the PD controller. MATLAB Simulink is used to analyze the model. Results show that the proposed AFC-based system with a piezoelectric actuator and a PD controller is very effective in suppressing the tremor for the three models.
Using piezoelectric material as a smart material for AVC has been of interest to many researchers. Human forearm is modelled as a continuous beam which has a layer of piezoelectric actuator on its top surface and tremor is controlled actively. Also using piezoelectric material as an actuator and sensor in the closed loop control system has a very significant effect on tremor suppression. A closed loop active control system is developed and the human forearm is modeled as a beam which has two layers of piezoelectric on its top and bottom surface as an actuator and sensor respectively. Tremor behaviour of the model is studied in this control system to identify the effect of piezoelectric material on tremor suppression. Hamilton principle is used to obtain the equation of motion of both beam model. Thus, by employing the Galerkin procedure, the governing equation of motion which is a second order ordinary differential equation in time is derived. An external force as a tremor disturbance is applied to the beam by a sinusoidal force to analyse the beam behaviour. The response of the system to the force stimulation gives the analytical relations for natural frequency and amplitude of the vibration. Using the obtained analytical relations, the effects of different factors and piezoelectric properties on the vibration of this beam are examined. The results indicate that the piezoelectric layer as an actuator provides an effective tool for active control of vibration. Also using a piezoelectric layer as a sensor and actuator on the closed loop control system has a significant effect on tremor suppression.
Tremor characteristics help researchers to find the best treatment for its suppression. The frequency and amplitude of tremor have different level in patients. Some patients experience a severe kind of tremor compared to others who have weak tremor. As a result, tremor classification for PD subjects provides beneficial information for the researchers.
Human hand tremor is recorded using electromyography (EMG) from 14 patients who are affected by Parkinson’s disease. Different signal-processing including filtering and data segmentation, feature extraction, feature reduction and classification are applied to the raw EMG signal to get accurate and useful information from recorded signals. Extreme learning machine (ELM) was used to classify data into three different classifications; severe, moderate and weak. The results illustrate that the proposed system which consists of the PCA, ELM and the majority vote is successful to recognising the tremor severity in three different classes; weak, moderate and severe
Factors affecting IUD discontinuation in women referring to Shahrekord health centers in 2010
زمینه و هدف: آی یو دی (IUD) از جمله روشهای سالم، موثر، ارزان، برگشت پذیر با میزان شکست پائین است که اساسیترین ویژگی آن طولانیمدت بودن اثر پیشگیری از بارداری میباشد. با این حال در بسیاری موارد اقدام به خروج IUD پیش از موعد صورت میگیرد و شناخت عوامل مسبب قطع استفاده از IUD اطلاعات مفیدی برای سیستم بهداشتی فراهم میآورد. این پژوهش با هدف تعیین عوامل موثر بر خروج پیش از موعد IUD در زنان مراجعهکننده به مراکز بهداشتی درمانی شهر شهرکرد انجام گردید. روش بررسی: این مطالعه مقطعی بر روی 182 زن تحت پوشش مراکز بهداشتی درمانی شهر شهرکرد که در طی سال 1389جهت خروج قبل از موعد IUD به این مراکز مراجعه نمودند، انجام شد. روش نمونه-گیری، آسان و مبتنی بر هدف و اطلاعات لازم از طریق پرسشنامه و مصاحبه گردآوری و با استفاده از آزمون های آماری تی استیودنت، کای اسکوئر، آنالیز واریانس یک طرفه، ضریب همبستگی پیرسون تحت نرم افزار آماری SPSS با سطح معنی داری داده ها کمتر از 05/0 تجزیه و تحلیل گردید. یافتهها: مهمترین علل خارجسازی پیش از موعد IUD به ترتیب خونریزی(2/29)، تمایل به حاملگی مجدد(7/26)، جابجایی IUD(9/14 )، عفونت(8/11٪)، درد زیر شکم(5/7٪) و اختلال قاعدگی(6/5٪) بود. مشاوره قبل از گذاشتن IUDبا مدت زمان استفاده از IUD و عوارض جانبی آن ارتباط معنیداری داشت(001/0
Electrical Capacitance Tomography to Measure Moisture Distribution of Polymer Foam in a Microwave Drying Process
Moisture distribution information is a critical element in drying processes. The drying of products by employing high-power microwave (MW) technology is widely used in the industry. Although microwaves allow volumetric and selective heating resulting in a significant reduction of processing time and energy consumption, there is always a risk of non-uniform moisture distribution in the final product. This paper investigates the capability of a designed electrical capacitance tomography (ECT) sensor to estimate the moisture distribution of polymer foams in a microwave drying process. The moisture distribution is estimated based on the non-intrusive contactless measurements of the electrical capacitances between the electrodes mounted on a frame around the target polymer foam. The obtained moisture information can be employed as feedback to a controller to adjust the power level of each microwave source in the microwave system to reduce or eliminate the non-homogeneity of the moisture distribution inside the polymer foam. In a series of experiments, we first examine the capability of the ECT sensor in estimating the moisture distribution in a stationary foam. We extend the tests to estimating the moisture distribution in a case where the foam is moving on a conveyor belt. Several study variables are taken, including the sample size, the sample location, the moisture percentage, the conveyor belt speed, and the microwave power. These experiments show that the sensor has a satisfactory accuracy in estimating the moisture distribution of the foam, and the ECT measurements can be further used in a closed-loop control system
Complete Genotype and Clinical Phenotype of Hemophilia B: A Study on Iranian Patients
Background: Hemophilia B which refers to the deficiency or functional defect of factor IX (FIX) is typically an X-linked bleeding condition that arises from heterogeneous mutations of the FIX gene (F9). The number of hemophilia cases in Iran is considerable and currently, about 1118 Iranian patients are suffering from hemophilia B, although a small number of them underwent genetic investigations. Here we assessed molecular defects and also laboratory and clinical findings of 10 Iranian cases with hemophilia B.
Materials and Methods: A total of 10 cases with hemophilia B were enrolled in the study. Patients were clinically examined by a hematologist and their previous medical documents were surveyed carefully. Routine coagulation tests and FIX activity and antigen assays were performed for the studied patients. Genotyping of F9 for identifying genetic mutations was conducted by the Sanger sequencing method following PCR amplification of the promoter region and all the eight exons of the F9 gene.
Results: The mean age of patients was 4 years (9 months to 16 years) and consanguinity was reported in 80% of cases. Patients were commonly manifested by hematoma (90%), epistaxis (80%), and hemarthrosis (70%) and the severity of the disorder was severe (70%) or moderate (30%). In nine out of 10 patients a genetic defect in F9 gene we detected including three missense (c.304T>C, c.1007T>A, c.191G>A) and three nonsense mutations (c.892C>T, c.880C>T, c.1113C>A). Based on the FIX variant database (http://www.factorix.org), five mutations have been reported previously, but mutation c.1007T>A (p.Ile336Asn) seems to be a novel mutation.
Conclusion: Our results indicated the heterogeneous molecular defects of hemophilia B in Iran, as recorded in the FIX mutation database. Moreover, no specific genotype-phenotype association was observed in studied subjects
Optimal Water Allocation among Agricultural Consumers Using Crop Pattern Change Approach to Improve Farmers' Livelihood
Qazvin plain is one of the areas in the country facing a severe shortage of water. In recent years, after the reduction of water allocation to this plain from Taleghan Dam, farmers have been digging illegal wells or over-harvesting existing wells in order to maintain their livelihoods. This has adverse effects, including severe depletion of wells, drying of aqueducts, salinity and degradation of groundwater quality, reduced yield of agricultural products, loss of soil quality, imposition of high costs on well owners, creating a major supply problem. Drinking water in cities and villages and eventually land subsidence (Qazvin Regional Water Authority, 2014). Studies show that the cultivation pattern in the last ten years has been almost constant and included wheat products, forage corn, canola, tomato, alfalfa, barley, sugar beet, peas, beans, potatoes, corn and lentils (Simiari and Mazandaranizadeh, 2017).Studies have shown that previous studies have either optimized water distribution or optimized cultivation patterns, but this study compared the differences between the two approaches to farmers' livelihoods in order to conserve groundwater resources
"Planning eye health services in Varamin district, Iran: a cross-sectional study".
BACKGROUND: A recent survey of avoidable blindness in Varamin District, Iran, identified moderately high levels of visual impairment (10%) and blindness (1.5%) in people >50 years. This study aimed to define current provision, identify gaps and suggest practical solutions for improving eye health services in this area. METHODS: The World Health Organization (WHO) framework for analyzing health systems has several key components: service delivery, health workforce, information system, medical products and technologies, financing, and governance. We used this structure to investigate the strengths and weaknesses of the eye health system in Varamin. All public and private eye care facilities and a random selection of primary health care (PHC) units were assessed using semi-structured researcher-administered questionnaires. RESULTS: Varamin has 16 ophthalmic clinics, including two secondary hospitals that provide cataract surgery. There were ten ophthalmologists (1:68,000 population), two ophthalmic nurses and five optometrists working in Varamin district. There were no eye care social or community workers, ophthalmic counsellors, low vision rehabilitation staff. Although the Vision 2020 target for ophthalmologists has been met, numbers of other eye care staff were insufficient. The majority of patients travel to Tehran for surgery. The recent survey identified cataract as the leading cause of blindness, despite the availability of surgical services in the district and high health insurance coverage. Poor awareness is a major barrier. No units had a written blindness prevention plan, formal referral pathways or sufficient eye health promotion activities. Only one of the PHC units referred people with diabetes for retinal examination. There is partial integration between eye care services and the general health system particularly for prevention of childhood blindness: chemo-prophylaxis for ophthalmia neonatorum, school vision tests, measles immunization and Vitamin A supplementation. CONCLUSIONS: This analysis demonstrated the need for better integration between eye care services and the general health system, local planning for prevention of blindness, an information system, a better staff mix and health education to increase community awareness and service uptake. There is the capacity to deliver far more surgery locally. All aspects of a health system need to be developed to deliver comprehensive and efficient eye care
The relationship of high-sensitivity C-reactive protein (Hs-CRP) serum level and peritonitis in patients on peritoneal dialysis
Background: C-reactive protein (CRP) is a predictor of cardiovascular diseases in both normal people and patients on hemodialysis. This study aimed to assess the relationship of high-sensitivity C-reactive protein (Hs-CRP) serum level and peritonitis in patients on peritoneal dialysis. Methods: 113 patients on peritoneal dialysis in Isfahan city, Iran, participated in our study in 2015. Serum albumin and Hs-CRP levels were measured in each patient at three times (baseline, and 6 and 12 month after that) and the patients were followed up for 1 year. All the patients were evaluated for peritonitis in every visit. At the end of the study, two groups of patients on peritoneal dialysis with and without peritonitis were compared. Findings: Among 113 patients, 24 were excluded from the study because of death or kidney transplantation and 89 patients were included in final analysis. The mean Hs-CRP levels in patients with peritonitis were 4.83, 5.79, and 7.42 mg/l at baseline, and 6 and 12 month after it, respectively; these levels were 4.47, 3.19, and 2.69 mg/l in patients without peritonitis, respectively. In addition, the mean albumin levels in patient with peritonitis were 3.38, 3.29 and 3.40 mg/l at baseline, and 6 and 12 month after it, respectively; these values were 3.56, 4.05, and 3.51 mg/l in patients without peritonitis, respectively. Conclusion: Results showed that with increase in Hs-CRP level, the risk of peritonitis increased. Besides, the albumin level decreased among patients with peritonitis in comparison with patients without peritonitis; there was no significant correlation between albumin level and peritonitis. © 2017, Isfahan University of Medical Sciences(IUMS). All rights reserved
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