Publications by authors named "Ali H Alqahtani"

Kite and Ponseti methods are two popular manipulating methods for correcting the deformity of idiopathic congenital clubfoot. We aimed to compare the efficacy of Kite and Ponseti methods in the treatment of children with idiopathic congenital clubfoot. A search was launched on Medline/PubMed, Cochrane Central Register of Controlled Trials, the Web of Science, ProQuest, and Scopus without limits, from inception to May 1, 2024.

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Switched filter banks find widespread application in frequency-hopping radar systems and communication networks with multiple operating frequencies, especially in situations demanding elevated filter element isolation. In this paper, the design and implementation of a highly isolated switchable narrow-bandpass filter bank architecture using hairpin microstrip topology is presented. The filter bank has four discrete bandpass filters with passbands of 2.

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This paper presents a miniaturized broadband Bi-Yagi antenna array that covers a bandwidth from 1.79 GHz to 2.56 GHz.

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This work presents an optically transparent and flexible MIMO antenna that features two square patch elements placed in close proximity, aiming to meet the demands of compactness, flexibility, optical transparency, and visual appeal for IoT applications and future 5G wireless communication. The design includes a simple offset fed configuration to achieve the required isolation and impedance matching. It simplifies the process of creating closely spaced transparent MIMO antenna configurations.

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This paper presents a novel circularly polarized rectenna designed for efficient electromagnetic energy harvesting at the 2.45 GHz ISM band. A compact antenna structure is designed to achieve high performance in terms of radiation efficiency, axial ratio, directivity, effective area, and harmonic rejection over the entire bandwidth of the ISM frequency band.

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In this letter, a compact, planar circularly polarized (CP) sub-GHz slot-based multiple-input-multiple-output (MIMO) antenna with dual sense CP along with polarization bandwidth reconfigurability is presented. The pentagonal reactively loaded slot is fed by two folded tapered feedlines to achieve CP. The antenna offers left-hand-circular polarization (RHCP) with the as well as right hand circular polarization (LHCP).

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Since the CubeSats have become inherently used for the Internet of space things (IoST) applications, the limited spectral band at the ultra-high frequency (UHF) and very high frequency should be efficiently utilized to be sufficient for different applications of CubeSats. Therefore, cognitive radio (CR) has been used as an enabling technology for efficient, dynamic, and flexible spectrum utilization. So, this paper proposes a low-profile antenna for cognitive radio in IoST CubeSat applications at the UHF band.

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A compact, conformal, all-textile wearable antenna is proposed in this paper for the 2.45 GHz ISM (Industrial, Scientific and Medical) band. The integrated design consists of a monopole radiator backed by a 2 × 1 Electromagnetic Band Gap (EBG) array, resulting in a small form factor suitable for wristband applications.

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In this paper, a folded slot-based multiple-input-multiple-output (MIMO) antenna design for Cube Satellite (CubeSat) applications is presented for the ultra-high frequency (UHF) band. A unique combination of a reactively loaded meandered slot with a folded structure is presented to achieve the antenna's miniaturization. The proposed antenna is able to operate over a wide frequency band from 430~510 MHz.

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This study examines the analytical and numerical solution of electromagnetic surface waves supported by a resistive metasurface-covered grounded metamaterial structure. To simulate the metamaterial, the Kramers-Kronig relation based on the causality principle is used, while the modeling of the resistive metasurface has been done by implementing the impedance boundary conditions. The analytical expressions for the field phasors of surface waves are developed for the transverse magnetic (TM) polarized mode and transverse electric (TE) polarized mode.

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Objective To assess the level and determinants of practice in diabetes self-management at primary health care centers (PHCCs) and to analyze the association of self-management with the level of glycemic control. Method A cross-sectional study was conducted among patients with type 1 and type 2 diabetes, aged ≥ 17 years, and being followed at PHCCs in Jeddah, Saudi Arabia, from December 1, 2019, to December 30, 2019. A multistage cluster sampling technique was used to select 350 participants from five PHCCs.

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Objective: Drug poisoning is a globally common cause of emergency-room admissions. This study explores drug-poisoning prevalence patterns, associated risk factors (gender, age and exposure circumstances), and outcomes in western Saudi Arabia.

Methods: Retrospective analysis of Clinical drug poisoning cases (2011-2016).

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Background: Poisoning is a significant global public health challenge in terms of morbidity and mortality. We conducted this study because of the lack of large population-based studies on chemical poisoning in Saudi Arabia.

Objective: Describe epidemiological trends, associated factors, and outcomes of chemical poisoning cases reported to the Jeddah Health Affairs Directorate, Saudi Arabia.

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Objective: To analyze the pattern of utilization of diagnostic tests by the Primary Care Services of the National Guard Housing Complex at Riyadh, Kingdom of Saudi Arabia and to correlate this pattern with other variables (age, gender, problem or diagnosis).

Methods: This is a retrospective cross-sectional medical record of the use of laboratory and x-ray facilities in the primary care setting using International Classification of Primary Care (ICPC-2) for encoding of data. The study was carried out at King Fahad National Guard Hospital covering a period of one year from January 1998 to December 1998.

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