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1.
Tunis Med ; 101(2): 306-312, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-37682277

RESUMO

INTRODUCTION: Asthma is a widespread chronic respiratory disease. It affects all age groups, mainly youth. Its management aims to prevent exacerbations and ensure normal daily-life activity. Current international recommendations attach particular importance to the therapeutic education to improve asthma control and reduce emergency room visits. AIM: To assess the impact of online therapeutic education for youth asthmatics initiated in the emergency department on the level of asthma's control. METHODS: Descriptive-evaluative study conducted over six months including asthmatics aged 14 to 35 years old living in Ariana. Asthma control was evaluated according to the 2019 Global Initiative for Asthma recommendations with a reassessment at three months after online therapeutic education. RESULTS: N=75; 18% of patients were adolescents, sex-ratio = 0.56. University education was noted in 73% of cases and high socioeconomic status in 48% of subjects. 55% of participants had no basic knowledge of the asthma's pathophysiology. Moderate classification of the last exacerbation was noted in 71% of patients and humidity was the most common exacerbation trigger (76%). A significant improvement in asthma control was observed after therapeutic education (p <0.001) with a positive correlation with female gender (p=0.048), basic knowledge of asthma's pathophysiology (p=0.001) and mild classification of the last exacerbation (p=0.039). Male gender and humidity as exacerbation trigger were independent factors negatively influencing control outcome after therapeutic education. CONCLUSION: The emergency department is the referral unit of the management of asthmatics with acute events. This represents an important opportunity to share educational messages that have proven effective using an online model.


Assuntos
Asma , Educação a Distância , Humanos , Adolescente , Feminino , Masculino , Adulto Jovem , Adulto , Asma/epidemiologia , Asma/terapia , Escolaridade , Atividades Cotidianas , Serviço Hospitalar de Emergência
2.
Sensors (Basel) ; 23(11)2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37300033

RESUMO

The permittivity of a material is an important parameter to characterize the degree of polarization of a material and identify components and impurities. This paper presents a non-invasive measurement technique to characterize materials in terms of their permittivity based on a modified metamaterial unit-cell sensor. The sensor consists of a complementary split-ring resonator (C-SRR), but its fringe electric field is contained with a conductive shield to intensify the normal component of the electric field. It is shown that by tightly electromagnetically coupling opposite sides of the unit-cell sensor to the input/output microstrip feedlines, two distinct resonant modes are excited. Perturbation of the fundamental mode is exploited here for determining the permittivity of materials. The sensitivity of the modified metamaterial unit-cell sensor is enhanced four-fold by using it to construct a tri-composite split-ring resonator (TC-SRR). The measured results confirm that the proposed technique provides an accurate and inexpensive solution to determine the permittivity of materials.


Assuntos
Eletricidade , Refração Ocular , Condutividade Elétrica
3.
Sci Rep ; 12(1): 17893, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36284228

RESUMO

An innovative off-chip antenna (OCA) is presented that exhibits high gain and efficiency performance at the terahertz (THz) band and has a wide operational bandwidth. The proposed OCA is implemented on stacked silicon layers and consists of an open circuit meandering line. It is shown that by loading the antenna with an array of subwavelength circular dielectric slots and terminating it with a metamaterial unit cell, its impedance bandwidth is enhanced by a factor of two and its gain on average by about 4 dB. Unlike conventional antennas, where the energy is dissipated in a resistive load, the technique proposed here significantly reduces losses. The antenna is excited from underneath the antenna by coupling RF energy from an open-circuited feedline through a slot in the ground-plane of the middle substrate layer. The feedline is shielded with another substrate layer which has a ground-plane on its opposite surface to mitigate the influence of the structure on which the antenna is mounted. The antenna has the dimensions 12.3 × 4.5 × 0.905 mm3 and operates across the 0.137-0.158 THz band corresponding to a fractional bandwidth of 14.23%. Over this frequency range the average measured gain and efficiency are 8.6 dBi and 77%, respectively. These characteristics makes the proposed antenna suitable for integration in sub-terahertz near-field electronic systems such as radio frequency identification (RFID) devices with high spatial resolution.

4.
Sci Rep ; 11(1): 10218, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986311

RESUMO

This paper presents the results of a study on developing an effective technique to increase the performance characteristics of antenna arrays for sub-THz integrated circuit applications. This is essential to compensate the limited power available from sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain performance however in the case of small-sized array structures the radiation properties can be adversely affected by mutual coupling that exists between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling effects. Prototype of 2 × 3 antenna arrays were designed and constructed on a polyimide dielectric substrate with thickness of 125 µm for operation across 0.19-0.20 THz. The dimensions of the array were 20 × 13.5 × 0.125 mm3. Metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding the patch antennas in the array with sub-wavelength slots. Compared to the reference array the metamaterial inspired structure exhibits improvement in isolation, radiation gain and efficiency on average by 28 dB, 6.3 dBi, and 34%, respectively. These results show the viability of proposed approach in developing antenna arrays for application in sub-THz integrated circuits.

5.
Sensors (Basel) ; 19(5)2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871001

RESUMO

Remote monitoring applications in urban vehicular ad-hoc networks (VANETs) enable authorities to monitor data related to various activities of a moving vehicle from a static infrastructure. However, urban environment constraints along with various characteristics of remote monitoring applications give rise to significant hurdles while developing routing solutions in urban VANETs. Since the urban environment comprises several road intersections, using their geographic information can greatly assist in achieving efficient and reliable routing. With an aim to leverage this information, this article presents a receiver-based data forwarding protocol, termed Intersection-based Link-adaptive Beaconless Forwarding for City scenarios (ILBFC). ILBFC uses the position information of road intersections to effectively limit the duration for which a relay vehicle can stay as a default forwarder. In addition, a winner relay management scheme is employed to consider the drastic speed decay in vehicles. Furthermore, ILBFC is simulated in realistic urban traffic conditions, and its performance is compared with other existing state-of-the-art routing protocols in terms of packet delivery ratio, average end-to-end delay and packet redundancy coefficient. In particular, the results highlight the superior performance of ILBFC, thereby offering an efficient and reliable routing solution for remote monitoring applications.

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