Dumbbell shaped structure loaded modified circular ring resonator based perfect metamaterial absorber for S, X and Ku band microwave sensing applications.

In this paper, a new metamaterial absorber (MMA) is presented that exhibits peak absorptions at 3.26 GHz, 11.6 GHz, and 17.13 GHz within S, X, and Ku bands. The unit cell of the proposed MMA is constructed on an FR4 substrate having an electrical dimension of 0.144λ × 0.144λ, where wavelength, λ is calculated at the lowest absorption frequency. The unique structural design of the unit cell consists of two concentric copper rings with which dumbbell-shaped structures are attached. The rotating symmetrical structural design of this MMA provides around 93.8%, 96.47%, and 99.95% peak absorptance in the mentioned frequencies, which is invariable with the change of incident angle as well as polarization angle. The metamaterial properties of the proposed absorber are studied along with the surface current analysis. The MMA shows single negative behaviour and it also exhibits high-quality factors (Q factor) of 21.73, 41.42, and 51.90 at maximum absorptance frequencies. The MMA is analysed by it's equivalent circuit to understand the resonance phenomenon, which is verified through simulation in Advanced Design Systems (ADS) software. The testing is done on the developed prototype of the proposed MMA. Measurement results are in close proximity to the simulation results. Due to its high Q factor, high EMR, and insensitivity to polarization and angle of incidence, it can be utilized as a part of miniaturized microwave device. In addition, the proposed MMA can exhibit high sensing performance and flexibility to differentiate different oils in S, X, and Ku bands.

Retraction: Hemichorea: A Rare Neurological Complication of Diabetes Mellitus.

[This retracts the article DOI: 10.7759/cureus.21131.].

The Hyperledger fabric as a Blockchain framework preserves the security of electronic health records.

The Hyperledger Fabric (HF) framework is widely studied for securing electronic health records (EHRs) in the healthcare sector. Despite the various cross-domain blockchain technology (BCT) applications, little is known about the role of the HF framework in healthcare. The purpose of the systematic literature review (SLR) is to review the existing literature on the HF framework and its applications in healthcare. This SLR includes literature published between January 2015 and March 2023 in the ACM digital library, IEEE Xplore, SCOPUS, Springer, PubMed, and Google Scholar databases. Following the inclusion and exclusion criteria, a total of 57 articles emerged as eligible for this SLR. The HF framework was found to be useful in securing health records coming from the Internet of Medical Things (IoMT) and many other devices. The main causes behind using the HF framework were identified as privacy and security, integrity, traceability, and availability of health records. Additionally, storage issues with transactional data over the blockchain are reduced by the use of the HF framework. This SLR also highlights potential future research trends to ensure the high-level security of health records.

Sociodemographic predictors of confirmed COVID-19 mortality and hospitalization among patients in Saudi Arabia: Analyzing a national COVID-19 database.

BACKGROUND: Even with the widespread availability of vaccines for the COVID-19 disease, there is no sign of decline in the rate of spread of the disease. Based on findings of different studies across the globe, the disease is characterized by poor outcomes in specific sociodemographic categories such as age, gender and presence of symptoms. METHODS: In this study, we carried out a multivariable logistic regression analysis on a national database (HESN+) of confirmed COVID-19 cases in Saudi Arabia to determine predictors of hospitalization and mortality for these patients. RESULTS: Data was extracted for 328,301 confirmed COVID- 19 patients (mean age (SD) = 37.79 (1.68)) with 34.92% females and 65.08% males. Of these, 59.87% were Saudi Arabian citizens and 40.13% were non-Saudi. 68.91% of cases were discovered in Riyadh (n = 67,384), Makkah (n = 72,590) and the Eastern Province (n = 79,666). 72.2% of all cases were diagnosed and treated by the Ministry of Health (MOH). Of all confirmed cases, 95.28% showed one or more symptoms associated with COVID-19. 5.48% of these were hospitalized and 1.11% died. Predictors of mortality and hospitalization, respectively, included age (OR; 1.088 and 1.03), being male (OR; 1.443 and 1.138), nationality (OR; 2.11 and 1.993), presence of symptoms (OR; 1.816 and 4.386), and the health care sector in which patients received treatment (MOH OR; 1.352 and 4.731). CONCLUSION: We found that COVID-19-related hospitalization or mortality was higher among males, older adults, and patients showing one or more symptoms, and mortality likelihood was more than fourfold for patients treated by the MOH. Immigrants were also more likely to be hospitalized or die from COVID-19 infection compared to Saudi nationals.

Hemichorea: A Rare Neurological Complication of Diabetes Mellitus.

Diabetes mellitus is a prevalent metabolic disorder that has a wide range of complications. Neurological complications are common and include stroke and peripheral neuropathy. However, hemichorea is a very rare manifestation of diabetes mellitus. Chorea can be due to primary inherited conditions or secondary to other disorders. Careful evaluation of patients with chorea is crucial since secondary chorea can be managed with the treatment of the underlying cause. We report the case of a 51-year-old man who presented to the emergency department with a two-week history of sudden involuntary and random-appearing movements of the right upper and lower extremities. These movements were non-suppressible and disappeared during sleep. Further, the movements were not associated with any neurological symptoms, including headache, dizziness, weakness, sensory deficits, or loss of consciousness. The patient had a longstanding history of hypertension and diabetes mellitus. He reported that he was not compliant with his medications. Laboratory investigation revealed a very high level of blood glucose (580 mg/dL) with associated pseudohyponatreamia (127 mEq/L). Head computed tomography scan showed increased density in right caudate nuclei and putamen with no surrounding edema or mass effect. The findings were suggestive of non-ketotic hyperglycemic hemichorea based on the clinical, laboratory, and radiological laboratory findings. The patient received insulin therapy according to sliding-scale protocol. The chorea movements gradually improved and completely disappeared after the fourth day of admission with the normalization of glucose level. In view of this, emergency medicine physicians should consider non-ketotic hyperglycemia as a potential underlying etiology of acute hemichorea.

Validation of Arabic version of the Modified Dental Anxiety Scale (MDAS) and Kleinknecht's Dental Fear Survey Scale (DFS) and combined self-modified version of this two scales as Dental Fear Anxiety Scale (DFAS) among 12 to 15 year Saudi school students in Riyadh city.

AIMS: The aim of this study was to test the reliability and validity of the Arabic version of Modified Dental Anxiety Scale (MDAS), Dental Anxiety Scale (DAS), and a combined self-modified version of these scales and Dental Fear and Anxiety Scale (DFAS). We also aimed to assess the impact of dental fear and anxiety among Arabic-speaking 12-15-year-old Saudi students on their quality of life by correlating MDAS, DAS, and DFAS scores with other demographic data. MATERIALS AND METHODS: A cross-sectional study was conducted among 500 individuals (250 male and 250 female) in Riyadh city using a questionnaire. An unpaired t-test was used to check the mean difference between anxiety score among males and females, and one-way analysis of variance was used to check the mean difference between percentage anxiety score among different visit groups. Scheffe post hoc test was used to check the pairwise difference between the groups, and Cronbach's alpha was used to measure internal consistency of the questionnaire. RESULTS: Overall mean percentage DAS score was 51.1640 + 6.87358 and 55.2080 + 8.52805 for male and females, respectively. The overall mean percentage MDAS score was 51.6640 + 10.9478 and 58.3200 + 11.62990 for males and females, respectively. The overall mean total score was found to be 64.4080 + 11.80776 and 100.4680 + 12.34840 for males and females, respectively. All the above results were statistically significant by 5% (P < 0.001). Cronbach's alpha score for MDAS and DAS was found to be 0.843 and it was 0.960 for DFAS. It was found that removal of any item would have decreased the overall consistency, which indicated a high level of internal consistency for our scales. CONCLUSION: Saudi Arabian version of Arabic version of MDAS, DAS and DFAS have shown high validity and reliability, and can be used to assess the dental patient's anxiety and fear.