Publications by authors named "al-Khalidi A"

In this work, we study multiple epitaxial layer structures incorporating a resonant tunneling diode photodetector utilizing the InGaAs/InP material system for operation at the near-infrared region of 1.55 and 1.31 micrometers.

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Hemophagocytic Lymphohistiocytosis syndrome is fatal hyper-inflammatory condition due to over-activation of the immune system, being of primary and secondary types. This case report emphasizes the difficulty and challenge in and of the HLH diagnosis, and therapy should be employed promptly given the high mortality associated with HLH.

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Background: The overuse of short-acting β-agonists (SABA) is associated with poor asthma control. However, data on SABA use in the Gulf region are limited. Herein, we describe SABA prescription practices and clinical outcomes in patients with asthma from the Gulf cohort of the SABA use IN Asthma (SABINA) III study.

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Background And Aims: There are gaps in knowledge regarding the association between the ABO blood group and coronavirus disease 2019 (COVID-19) immediate and long-term outcomes. We aimed to investigate the association of ABO blood group with COVID-19 in-hospital adverse outcomes and to determine whether ABO blood group is associated with post-COVID-19 persistent symptoms.

Methods: This was a single-center longitudinal observational study that included patients who presented with symptoms suggestive of COVID-19 infection and a positive test for COVID-19 and were able to attend the out-patient clinic after 6 months following acute COVID-19.

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Objective: The study aimed to assess the long-term persistent symptoms of patients with diabetes mellitus (DM) and COVID-19 infection at 9 months after acute infection.

Methods: This single-center cross-sectional study was conducted from May 20 to June 1, 2021.

Results: A total of 112 patients were included in the present study.

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We investigate the dynamic behaviour of resonant tunneling diode-photodetectors (RTD-PDs) in which the excitability can be activated by either electrical noise or optical signals. In both cases, we find the characteristics of the stochastic spiking behavior are not only dependent on the biasing positions but also controlled by the intensity of the input perturbations. Additionally, we explore the ability of RTD-PDs to perform optical signal transmission and neuromorphic spike generation simultaneously.

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Background and Purpose- Identifying the etiology of acute ischemic stroke is essential for effective secondary prevention. However, in at least one third of ischemic strokes, existing investigative protocols fail to determine the underlying cause. Establishing etiology is complicated by variation in clinical practice, often reflecting preferences of treating clinicians and variable availability of investigative techniques.

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Background: Stroke is a leading cause of death and disability worldwide. Identifying the aetiology of ischaemic stroke is essential in order to initiate appropriate and timely secondary prevention measures to reduce the risk of recurrence. For the majority of ischaemic strokes, the aetiology can be readily identified, but in at least 30% of cases, the exact aetiology cannot be determined using existing investigative protocols.

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We report on the direct intensity modulation characteristics of a high-speed resonant tunneling diode-photodetector (RTD-PD) with an oscillation frequency of 79 GHz. This work demonstrates both electrical and optical modulation and shows that RTD-PD oscillators can be utilized as versatile optoelectronic/radio interfaces. This is the first demonstration of optical modulation of an RF carrier using integrated RTD-PD oscillators at microwave frequencies.

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Lemierre's syndrome (LS) is a serious rare complication of oropharyngeal infections. It is characterized by thrombosis of internal jugular vein that rapidly progresses into sepsis and is typically caused by anaerobes. Most of the reported cases have been linked to ; however, there are a handful of reported cases due to aerobes.

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Background: L-asparaginase is chemotherapeutic agent commonly used in treatment of Acute Lymphoblastic Leukemia. Thromboembolic and to a lesser extent bleeding events are serious complications associated with administration of this drug during the induction phase in ALL especially in children resulting from reduced synthesis of proteins such as Antithrombin & fibrinogen.

Objective: Evaluation of the coagulopathic side effect of L-asparaginase during the induction phase in treatment of ALL in children by measuring fibrinogen levels before & after administration of this drug.

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Group B Streptococcus (GBS) infection is a major cause of morbidity and mortality in infants. The major risk factor for GBS disease is maternal and subsequent infant colonisation. It is unknown whether human milk oligosaccharides (HMOs) protect against GBS colonisation.

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Objectives: We investigated the interaction of heart rate (HR), temperature and contractility using a validated load independent method.

Background: Temperature manipulation is an integral part of cardiac surgery, and postoperative hypothermia is extremely common. Myocardial contraction is a series of enzymatic and physico-chemical reactions that may be differentially affected by temperature.

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1. Studies of the effect of vagus nerve stimulation on ventricular myocardial function in mammals are limited, particularly in the human. 2.

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A simple and novel technique that utilizes the zero-crossing points of the first time derivative of intra-ventricular pressure (dP/dt) to mark systole, is proposed. Discrete differentiation of the sampled pressure waveform is calculated using a difference equation. Filtration of high-frequency noise in dP/dt is achieved using a low-pass Butterworth filter of order 4 and a cutoff frequency of 10 Hz.

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The development of the conductance catheter method has enabled continuous measurement of intraventricular volume in vivo, thus making assessment of pump performance of the heart in vivo possible using pressure-volume analysis. However, this method has not been validated under conditions where pump rate, conductance, viscosity, and temperature of the fluid in the heart chamber is changed as happens in cardiac surgery. To validate the method, pressure-volume data were measured by conductance catheter in a physical model of the human left ventricle.

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1. We have previously shown that brief voluntary isometric contractions of upper arm flexor muscles performed for one respiratory cycle elicit a significant decrease in the R-R interval. The present study was designed to determine if similar changes are produced by non-voluntary electrically evoked contractions and, if so, to establish the consistency and repeatability of the associated changes in the R-R interval.

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An open crossover study was carried out in 10 Arab patients with mild to moderate hypertension to compare the effectiveness and tolerability of labetalol with alpha-methyldopa. Patients were started on either 100 mg labetalol or 250 mg alpha-methyldopa 3-times daily and, if necessary, the dosage adjusted by standard increments every 2 weeks over a period of a month until satisfactory control was achieved. This dosage was then maintained for a further 6 weeks before the patients were crossed over to the alternative treatment, similarly adjusted, after a wash-out period of 2 weeks on placebo.

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Twenty-six patients suffering from methylmercury poisoning were treated by different therapeutic regimes. Seven received penicillamine or N-acetyl-d-L-penicillamine, 10 were treated with dimercaprol sulfonate and 9, who could not be treated, were given a placebo and were used as controls. Penicillamine, N-acetyl-d-L-penicillamine, and dimercaprol sulfonate reduced the blood level of mercury and increased its urinary excretion.

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