Samer Ouda - Academia.edu (original) (raw)

Papers by Samer Ouda

The development of Ultra Wide Band (UWB) technology, including antennas as an essential part of w... more The development of Ultra Wide Band (UWB) technology, including antennas as an essential part of wireless communication systems, is greatly accelerated. However, there are more challenges in designing a UWB antenna more than a narrow band one. It should be capable of operating over an ultra-wide bandwidth as allocated by the Federal Communications Commission (FCC) from 3.1GHz to 10.6GHz. At the same time, the radiation properties over the entire frequency range are also necessary to be satisfactory. This thesis focuses on a designing a novel microstrip Ultra Wide Band (UWB) antenna for optimum performance like wide bandwidth, good matching impedance, small antenna size exhibits a good voltage standing wave ratio (VSWR) performance and its E-and H-plane radiation patterns are stable over the UWB frequency range and others. This antenna has a new patch shape that allows for providing good properties. Discussing the necessary parameters of UWB antennas, and studying the techniques of enhancing the bandwidth of a microstrip UWB are also investigated, to get antenna exhibit excellent performance of UWB characteristics with

International Journal of Wireless & Mobile Networks, 2013

The design and analysis of a new ultra wideband microstrip antenna for optimum performance that s... more The design and analysis of a new ultra wideband microstrip antenna for optimum performance that satisfied a large bandwidth starting from 3.9GHz to 22.5GHz is introduced. The UWB antenna is capable of operating over an UWB as allocated by the Federal Communications Commission (FCC) with good radiation properties over the entire frequency range. The techniques of enhancing the bandwidth of microstrip UWB antenna were utilized to enhance the performance of the designed antenna. The effect of shifting feed line from the center of patch to the edges was studied in addition to the effect of changing the length of the ground plane. The antenna was designed and simulated using High Frequency Structure Simulator HFSS software packages..

Journal of Pain Research, 2021

Purpose: Patients with fibromyalgia (FM) may demonstrate low cortisol concentrations during diagn... more Purpose: Patients with fibromyalgia (FM) may demonstrate low cortisol concentrations during diagnostic evaluation. However, it remains unclear whether low cortisol reflects underlying pituitary dysfunction. We aimed to determine if a subset of patients with FM have concomitant secondary adrenal insufficiency (SAI) and growth hormone deficiency (GH). Patients and Methods: This is a retrospective study of all patients with FM diagnosed with SAI based on abnormal insulin tolerance test (ITT) between June 2002 and August 2019. Patients were excluded if they had other reasons for SAI. Measurements include cortisol and GH during ITT in all patients, and peak cortisol during cosyntropin stimulation test in a subset of patients. Results: We identified 22 patients (median age of 38 years (range 19-65), 18 (82%) women) diagnosed with secondary AI based on abnormal ITT (peak median cortisol level of 11 mcg/ dL (range 5.4-17)). Concomitant GH deficiency was diagnosed in 19 (86%) patients. Cosyntropin stimulation test was performed in 14 (64%) patients and was normal in 11 (79%) (peak cortisol ≥18 mcg/dL). MRI pituitary imaging was performed in 20 patients and showed no significant pituitary pathology. All patients were started on physiologic glucocorticoid replacement, and 5 patients were started on GH replacement. Of the 13 patients with follow-up, 8 (62%) reported symptom improvement after starting treatment. Conclusion: Patients with FM can have concurrent SAI and GH deficiency. Cosyntropin stimulation test should not be used to exclude SAI in patients with FM. Appropriate glucocorticoid and/or GH replacement may improve symptoms in some patients.

Journal of the American Academy of Dermatology, 2020

Journal of the Endocrine Society, 2020

Introduction: Low or borderline cortisol concentrations and impaired response to dynamic testing ... more Introduction: Low or borderline cortisol concentrations and impaired response to dynamic testing have been reported in patients with fibromyalgia, potentially related to hypothalamus-pituitary dysfunction.1,2 Superimposed adrenal insufficiency (AI) may contribute to some fibromyalgia symptoms or delay improvement in patients enrolled in fibromyalgia treatment programs. We hypothesized that a subset of patients with fibromyalgia have: 1) partial secondary AI and concomitant growth hormone (GH) deficiency 2) a discordance in Cosyntropin stimulation test and 3) improvement in fibromyalgia symptoms with initiation of glucocorticoid and/or GH replacement. Design: This was a retrospective study of patients with fibromyalgia diagnosed with partial secondary AI based on abnormal insulin tolerance test (peak cortisol < 18 mcg/dL) at our institution from June 2002 to August 2019. Patients were excluded if they had other reasons for adrenal insufficiency, including steroid exposure and opio...

Journal of the American Society of Hypertension, 2018

European Journal of Plastic Surgery, 2019

Background An estimated 1.4 million transgender individuals currently reside in the USA and this ... more Background An estimated 1.4 million transgender individuals currently reside in the USA and this patient population is increasing on an annual basis (Am J Public Health 107: 1-8, 2017). Along with this census increase, there has also been an increasing number of gender confirmation surgeries being performed in the USA (American Society of Plastic Surgeons, 2016). Our primary objective was to study the effects of hormonal therapy on testicular volumetrics on transgender patients who underwent male-to-female (MtF) bottom gender confirmation surgery. Methods Retrospective review of patients who underwent MtF bottom gender confirmation surgery. Based on World Professional Association for Transgender Health (WPATH) guidelines a minimum of 1 year of hormonal therapy was required in order to be included. Two groups were analyzed based on their hormone therapy regimen (estrogen and estrogen/progesterone). Demographics, comorbidities, body mass index (BMI), medications (and length of use), testicular volumetrics (weight, length of spermatic cord, volume), and post-operative complications (dehiscence, seroma, hematoma, infection, return to the OR) were analyzed. Results A total of 54 patients were analyzed. The mean age of the sample population was 37.7 (± 13.3) years old. The mean difference in BMI before and after hormonal treatment was − 0.14 (± 1.7) in the estrogen only group and + 0.3 (± 1.7) in the estrogen/progesterone (combined) group (p = 0.396). The mean weight of surgical specimens in the estrogen only and in the combined group was 30.2 (± 14.9) and 24.1 (± 8.7), respectively (p = 0.033). The spermatic chord length for patients in the estrogen group was 5.4 cm (± 1.7), and 4.5 cm (± 1.6) for patients in the combined group (p = 0.009). Of all the patients, 18 presented with minor wound dehiscence of labia majora. Analysis of complications regarding to the type of hormonal therapy they received showed no difference among patients in the estrogen only and the combined group (p = 0.859). Conclusion Hormone therapy is an integral aspect of a multidisciplinary approach to transgender medicine and surgery. Further studies are required to elucidate systemic effects in detail and evaluate outcomes in a post-operative setting. Level of Evidence: Level III, risk /prognostic study.

The Journal of Clinical Endocrinology & Metabolism, 2017

Context: The transgender population continues to face challenges in accessing appropriate health ... more Context: The transgender population continues to face challenges in accessing appropriate health care. Adequate training of endocrinologists in this area is a priority. Objectives: Assess the status of transgender health care education in US endocrinology fellowship training programs and assess knowledge and practice of transgender health among practicing US endocrinologists. Design: Mayo Clinic and the Endocrine Society developed and administered a Web-based anonymous survey to 104 endocrinology fellowship program directors (PDs; members of the Association of Program Directors in Endocrinology, Diabetes and Metabolism) and 6992 US medical doctor members of Endocrine Society. Results: There were 54 total responses from 104 PDs (51.9%). Thirty-five of these 54 programs (72.2%) provide teaching on transgender health topics; however, 93.8% respondents indicated that fellowship training in this area is important. Barriers to provision of education included lack of faculty interest or experience. The most desired strategies to increase transgender-specific content included online training modules for trainees and faculty. Of 411 practicing clinician responders, almost 80% have treated a transgender patient, but 80.6% have never received training on care of transgender patients. Clinicians were very or somewhat confident in terms of definitions (77.1%), taking a history (63.3%), and prescribing hormones (64.8%); however, low confidence was reported outside of the hormonal realm. The most requested methods of education included online training modules and presentation of transgender topics at meetings. Conclusions: Confidence and competence in transgender health needs to increase among endocrinologists. Strategies include the development of online training modules, expansion of formal transgender curricula in fellowship programs, and presentations at national and international meetings.

Current Opinion in Endocrinology, Diabetes & Obesity, 2008

Purpose of review The physiological role of dehydroepiandrosterone remains unclear, and there is ... more Purpose of review The physiological role of dehydroepiandrosterone remains unclear, and there is continuing controversy on whether dehydroepiandrosterone treatment benefits adrenaldeficient and elderly people with an age-related decline in dehydroepiandrosterone. The objective of this study is to critically review published results and determine whether there is a valid case for dehydroepiandrosterone treatment with advancing age and hypoadrenalism. Recent findings Oral dehydroepiandrosterone therapy in both elderly and hypoadrenal subjects achieves dehydroepiandrosterone levels comparable to young subjects. Long-term dehydroepiandrosterone replacement in elderly people demonstrated no improvement in body composition, physical performance or any metabolic parameters; however, a modest but inconsistent improvement in bone mineral density occurred at certain sites. Dehydroepiandrosterone replacement in hypoadrenalism modestly improved insulin sensitivity and altered the lipid profile, but it remains uncertain whether these changes improve any patient-important outcomes. Dehydroepiandrosterone replacement in adrenal deficiency inconsistently improves some aspects of mental health. Summary Dehydroepiandrosterone replacement increases bone mineral density in elderly subjects; however, the effect is relatively small compared with established therapies for osteoporosis. No additional benefits have been identified for long-term dehydroepiandrosterone replacement, when used in the elderly to prevent or delay ageing. Dehydroepiandrosterone replacement may improve some metabolic variables and measures of psychological well-being in adrenal deficiency, but these benefits are not consistently sustained in long-term therapy. Long-term studies are needed to confirm sustained benefits in adrenal deficiency and establish long-term safety.