50 research outputs found

    Exacerbation of hypereosinophilic syndrome with pulmonary involvement in two consecutive pregnancies: a case report and review of the literature

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    Hypereosinophilic syndrome represents a heterogeneous group of disorders with the common feature of prolonged eosinophilia of unknown cause and organ system dysfunction including the pulmonary system. Hypereosinophilic syndrome, with and without pulmonary involvement, in association with pregnancy is very rare, and to the best of our knowledge only one case of hypereosinophilic syndrome with pulmonary involvement during pregnancy has been previously reported in the medical literature. We describe a case of a patient with previously symptomatic hypereosinophilic syndrome with pulmonary involvement who experienced exacerbations of her disease during two consecutive pregnancies. To the best of our knowledge this is the first report which demonstrates a worsening effect of pregnancy on both eosinophil count and end organ involvement in a patient with previous diagnosis of hypereosinophilic syndrome

    Nausea and vomiting as major presenting symptoms of thyrotoxicosis after bilateral adrenalectomy for Cushing's disease

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    Thyrotoxicosis has a variety of presentations which depend on its severity and duration, as well as the age of the patient. In elderly patients, thyrotoxicosis may present with a variety of nonspecific symptoms. Nausea and vomiting as major presenting symptoms of thyrotoxicosis have rarely been reported. Thyrotoxicosis after adrenalectomy in patients with Cushing's syndrome and normal thyroid function, or with autoimmune thyroid dysfunction has rarely been reported previously. We describe a very rare case of an elderly patient with hypothyroidism due to Hashimoto's thyroiditis who presented with persistent nausea and vomiting as major presenting symptoms of thyrotoxicosis, which developed after bilateral adrenalectomy for Cushing's disease. Similar case has not been reported previously. In reporting this patient we aim at drawing attention to these forgotten symptoms of thyrotoxicosis, nausea and vomiting, and to emphasize that, at times, these symptoms may be the only presenting features of thyrotoxicosis, leading to considerable difficulty in diagnosis. Furthermore, cessation of glucocorticoid excess may sometimes be accompanied with thyrotoxicosis

    Chronic Stanford type A aortic dissection manifesting as systemic inflammatory disorder

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    Typical presentation of type A aortic dissection usually encompasses severe acute chest pain, frequently radiating to the upper back, which is seen in more than 80% of the patients, while isolated back or abdominal pain have been repeatedly reported as the first manifestation of the disease as well. Occasionally, dyspnea due to acute aortic regurgitation, syncope, or stroke, secondary to obstruction of major cerebral vessels, have also been described at presentation of type A aortic dissection. Presentation of aortic dissection as a prolonged systemic illness with a number of nonspecific clinical and laboratory findings, such as low-grade fever, fatigue, malaise, weight loss, anemia, elevated acute phase response laboratory parameters, and absence of any of typical clinical features of the dissection syndrome has been only rarely reported. We describe a patient with type A chronic aortic dissection, manifesting as a systemic inflammatory disorder in the absence of acute chest syndrome. The diagnosis was made accidentally by computed tomography, ordered in the course of the regular work up. The patient underwent emergent surgery with resection and grafting of the dissected aorta. Pathological investigation demonstrated intense acute inflammation with neutrophilic infiltration in the vicinity of the intramural hemorrhage and necrosis, as well as granulation tissue with new vessels formation and collagen deposition in the outer media. The possible pathogenic mechanisms of the phenomenon are discussed

    Pinch-off effect in p-type double gate and single gate junctionless silicon nanowire transistor fabricated by atomic force microscopy nanolithography

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    The spark of aggressive scaling of transistors was started after the Moors law on prediction of device dimensions. Recently, among the several types of transistors, junctionless transistors were considered as one of the promising alternative for new generation of nanotransistors. In this work, we investigate the pinch-off effect in double gate and single gate junctionless lateral gate transistors. The transistors are fabricated on lightly doped (1015) p-type Silicon-on-insulator wafer by using an atomic force microscopy nanolithography technique. The transistors are normally on state devices and working in depletion mode. The behavior of the devices confirms the normal behavior of the junctionless transistors. The pinch-off effect appears at VG +2.0 V and VG +2.5 V for fabricated double gate and single structure, respectively. On state current is in the order of 10-9 (A) for both structures due to low doping concentration. The single gate and double gate devices exhibit an Ion/Ioff of approximately 105 and 106, respectively

    Field effect in silicon nanostructure fabricated by atomic force microscopy nano lithography

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    The electrical property of silicon nano-structure is highly considered in nanoelectronics. In this context we investigate the field effect in nanostructure Junctionless p-type silicon nanowire transistor under the lateral gate voltage. The device fabricated by means of Atomic Force microscopy (AFM) nano lithography on Silicon on Insulator (SOI) wafer. I-V characteristic and the Drain/Source current under the lateral gate voltage investigated. The subthreshold swing measured and hysteresis effect observed for the old sample compared to new one

    Up-scalable synthesis of size-controlled copper ferrite nanocrystals by thermal treatment method

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    Close-packed cubic copper ferrites (CuFe2O4) nanoparticles were synthesized using an effective thermal-treatment method directly from an aqueous solution containing copper and iron nitrates as metal precursors and poly(vinyl pyrrolidone) as a capping agent. The FTIR spectra of the calcined samples revealed the vibration bands of Fe–O and Cu–O at 315 and 535 nm respectively. The structural, morphological, optical and magnetic properties of the nanocrystal powder samples were analyzed using various characterization techniques. The powder X-ray diffraction unveiled the formation of spinel phase of CuFe2O4 with the average particle size determined from TEM images increased from 24 to 34 nm at the calcination temperatures between 773 and 1173 K. The band gap calculated using Kubelka–Munk function from the UV–visible diffuse reflectance spectra decreased from 2.64 to 2.45 eV with increasing calcination temperature. The electron spin resonance (ESR) spectroscopy confirmed the presence of unpaired electrons in the calcined samples. The g-factor increased from 2.10497 to 2.57056 and the resonance magnetic field decreased from 3.11599×10−7 to 2.55161×10−7 A/m with increasing calcination temperature

    Numerical study of side gate junction-less transistor in on state

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    Side gate p-type Junctionless Silicon transistor is fabricated by AFM nanolithography on low-doped (105 cm-3) SOI wafer. In this work, the simulation characteristic of the device using TCAD Sentaurus in on state will be studied. The results show that the device is the pinch off transistor, works in on state for zero gate voltage in depletion mode. Negative gate voltage drives the device into on state, but unable to make significant effect on drain current as accmulation mode. Simulation results for valence band energy, electric field and hole density are investigated along the active regions. The influence of the electric field due to the applied voltages of V DS and V G on charge distribution is much more when the device operates at the saturation region. The hole quasi-Fermi level has a positive slope showing the current flows from source to drain

    Dependency of electrical characteristics on nano gap variation in pinch off lateral gate transistors

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    The variation of electrical characteristics with nano size air gap variation between gates and channel of a pinch off lateral gate transistor were investigated using 3D Technology Computer Aided Design. It is found that smaller nanosize gaps which can be formed by approaching the lateral gates to the channel can improve the switching performance of the device significantly. Devices with different air gap demonstrate same on state current and maximum transconductance of 0.05 μS, however the on/off current ratio (ION/IOFF) is varied by three orders of magnitude. The parameters such as electric field and band energy variation are investigated in order to explain the variation of electrical characteristics by air gap variation

    SARS-CoV-2 Infection Is at Herd Immunity in the Majority Segment of the Population of Qatar.

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    BACKGROUND: Qatar experienced a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic that disproportionately affected the craft and manual worker (CMW) population, who comprise 60% of the total population. This study aimed to assess ever and/or current infection prevalence in this population. METHODS: A cross-sectional population-based survey was conducted during July 26 to September 09, 2020, to assess both anti-SARS-CoV-2 positivity through serological testing and current infection positivity through polymerase chain reaction (PCR) testing. Associations with antibody and PCR positivity were identified through regression analyses. RESULTS: The study included 2641 participants, 69.3% of whom were <40 years of age. Anti-SARS-CoV-2 positivity was 55.3% (95% CI, 53.3%-57.3%) and was significantly associated with nationality, geographic location, educational attainment, occupation, and previous infection diagnosis. PCR positivity was 11.3% (95% CI, 9.9%-12.8%) and was significantly associated with nationality, geographic location, occupation, contact with an infected person, and reporting 2 or more symptoms. Infection positivity (antibody and/or PCR positive) was 60.6% (95% CI, 58.6%-62.5%). The proportion of antibody-positive CMWs who had a prior SARS-CoV-2 diagnosis was 9.3% (95% CI, 7.9%-11.0%). Only seven infections were ever severe, and only 1 was ever critical-an infection severity rate of 0.5% (95% CI, 0.2%-1.0%). CONCLUSIONS: Six in every 10 CMWs in Qatar have been infected, suggestive of reaching the herd immunity threshold. Infection severity was low, with only 1 in every 200 infections progressing to be severe or critical. Only 1 in every 10 infections had been previously diagnosed, which is suggestive of mostly asymptomatic or mild infections
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