510 research outputs found

    Charged Particles Circular Orbits around Weakly Charged and Magnetized Kerr Black Holes

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    We study the circular orbits of charged particles around a weakly charged Kerr black hole immersed in a weak, axisymmetric magnetic field. Firstly, we review the circular orbits of neutral particles. We then review the circular orbits of charged particles around a weakly charged Kerr black hole and weakly magnetized Kerr black hole. The case of a weakly magnetized and charged black hole is investigated thereafter. We investigate, in particular, the effect of the electromagnetic forces on the charged particles' innermost stable circular orbits. We examine the conditions for the existence of negative-energy stable circular orbits and the possibility of the emergence of a gap or double orbit in thin accretion disks. Some of the interesting astrophysical consequences of our findings are discussed as well.Comment: Accepted for publication in the Astrophysical Journal. arXiv admin note: substantial text overlap with arXiv:2208.1395

    Particle Dynamics in Weakly Charged Extreme Kerr Throat

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    We study dynamics of a test charged particle moving in a weakly charged extreme Kerr throat. Dynamical equations of the particle motion are solved in quadratures. We show explicitly that the Killing tensor of the Kerr spacetime becomes reducible in the extreme Kerr throat geometry. Special types of motion of particles and light are discussed.Comment: The paper is prepared for the fest volume devoted to 75th Birthday of Mario Castagnin

    Diffuse Large B-Cell Lymphoma Transformed from Mucosa-Associated Lymphoid Tissue Lymphoma Arising in a Female Urethra Treated with Rituximab for the First Time

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    A 30-year-old female patient presented to the gynecology clinic with a small (painless) swelling at the urethral orifice. She underwent surgical excision of the lesion. Pathological examination revealed non-Hodgkin's lymphoma of diffuse large B-cell type and mucosa-associated lymphoid tissue type, stage IE. The patient refused radiotherapy. Accordingly, we started CHOP-R chemotherapy. She received a total of 6 cycles of CHOP and 8 cycles of rituximab. Patient follow-up was done 3 months later through CT scan and cytoscopy confirming the complete remission. The patient has been disease-free for 4 years. We reviewed 26 cases of this rare entity reported previously

    Factors affecting mental fitness for work in a sample of mentally ill patients

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    <p>Abstract</p> <p>Background</p> <p>Mental fitness for work is the ability of workers to perform their work without risks for themselves or others. Mental fitness was a neglected area of practice and research. Mental ill health at work seems to be rising as a cause of disablement. Psychiatrists who may have had no experience in relating mental health to working conditions are increasingly being asked to undertake these examinations. This research was done to explore the relationship of mental ill health and fitness to work and to recognize the differences between fit and unfit mentally ill patients.</p> <p>Methods</p> <p>This study was cross sectional one. All cases referred to Al-Amal complex for assessment of mental fitness during a period of 12 months were included. Data collected included demographic and clinical characteristics, characteristics of the work environment and data about performance at work. All data was subjected to statistical analysis.</p> <p>Results</p> <p>Total number of cases was 116, the mean age was 34.5 ± 1.4. Females were 35.3% of cases. The highly educated patients constitute 50.8% of cases. The decision of the committee was fit for regular work for 52.5%, unfit for 19.8% and modified work for 27.7%. The decision was appreciated only by 29.3% of cases. There were significant differences between fit, unfit and modified work groups. The fit group had higher level of education, less duration of illness, and better performance at work. Patients of the modified work group had more physical hazards in work environment and had more work shift and more frequent diagnosis of substance abuse. The unfit group had more duration of illness, more frequent hospitalizations, less productivity, and more diagnosis of schizophrenia.</p> <p>Conclusion</p> <p>There are many factors affecting the mental fitness the most important are the characteristics of work environment and the most serious is the overall safety of patient to self and others. A lot of ethical and legal issues should be kept in mind during such assessment as patient's rights, society's rights, and the laws applied to unfit people.</p

    Faculty Members Practice of 21st Century Skills in Teaching: A Perspective from Bisha University

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    This study aims to identify the teaching practices of faculty staff members at the University of Bisha in light of twenty-first century skills. The descriptive method is used as it suits the research aims. The faculty staff members demonstrate a high level of teaching practices in light of twenty-first century skills, with life and occupation skills ranking first, learning and creativity skills ranking second, and digital culture skills ranking third. The results show statistically significant dissimilarities in learning and creativity skills and life and occupation skills between the teaching practices of faculty staff members in favor of the Faculty of Engineering, while the difference in digital culture skills favors the Faculty of Education. Additionally, there is a statistically significant difference in the teaching practices of faculty staff members in the light of twenty-first century skills attributable to the variable of teaching experience, favoring the category of (5-10 years)

    Solid Pseudopapillary Tumor of the Pancreas: A Case Report

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    Introduction: Solid pseudopapillary tumor (SPT) of the pancreas is rare, accounting for 0.13-2.7% of all pancreatic tumors. It has specific clinical, pathological and radiological characters that make it quite different from other pancreatic tumors.Presentation of case:  A 15-year-old girl with SPT of the pancreas diagnosed after surgical resection with histopathology and immunohistochemistry confirmation. As no clear role for adjuvant treatment, she was elected for follow up.Conclusion: Although SPT is a rare tumor without notable symptoms. Complete surgical excision is the treatment of choice. The place of chemotherapy or radiotherapy needed to be elucidated
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