Asymmetric metamaterial sandwich structure with NIM characteristics for THz imaging application

This study presented a unique, miniaturised asymmetric interconnected vertical stripe (IVS) design for terahertz (THz) frequency applications. Therefore, this research aimed to achieve a frequency response of 0 to 10 THz using a 5 × 5 µm2 Silicon (Si) substrate material. Meanwhile, various parametric examinations were conducted to investigate variations in the performance. For example, the unit cell selection process was carefully examined by using various design structures and modifying the structure by adding split gaps and connecting bars between vertical stripes. Furthermore, the proposed sandwich structure design was used to compute the absorbance and reflectance properties. All the analytical examinations were executed utilising the Computer Simulation Technology (CST) 2019 software. The introduced IVS metamaterial exhibits negative index behaviour and has a single resonance frequency of 5.23 THz with an acceptable magnitude of - 24.38 dB. Additionally, the quadruple-layer IVS structure exhibits optimised transmission coefficient behaviour between 3 and 6 THz and 7 to 9 THz, respectively. However, the magnitude of the transmission coefficient increased with the number of material layers. Besides that, the absorbance study shows that using a quadruple-layer structure obtains unique and promising results. Overall, the proposed asymmetric IVS metamaterial design achieves the required performance by using a compact structure rather than extending the dimensions of the design.

The physiological and physical benefits of two types of concurrent training: a randomized controlled trial

BACKGROUND

It is widely acknowledged that aerobic exercise and strength training are crucial components of most workout programs. However, there is no consensus as to whether the effectiveness of exercises is affected by the sequence in which they are performed. Therefore, the overarching aim of the study was to understand the optimal order of two types of concurrent training program for 13 weeks by comparing the effectiveness of the training on body composition, predicated maximal oxygen uptake (VO2max), dynamic respiratory parameters and muscle strength in healthy middle-aged people.

METHODS

Thirty-three middle-aged individuals, who were categorized as moderately active based on their responses to International Physical Activity Questionnaires, underwent random allocation. The participants were randomly assigned into two groups: the Strength Training followed by Aerobic Training group (SAG, n = 16) and the Aerobic Training followed by Strength Training group (ASG, n = 17). Body composition, aerobic endurance, respiratory parameters, and upper and lower strength were assessed at baseline and after (post-test) a 13-week intervention. The chi-square test and the independent t-test were used to compare sociodemographic variables between the groups. A 2 × 2 analysis of variance (ANOVA) with repeated measures (group x measurement) was conducted. The study was retrospectively registered on clinicaltrials.gov in May of 2023 (clinicaltials.gov identifier: NCT05862415; in 04/25/2023).

RESULTS

Findings showed no significant differences between the group in the VO2max, FVC or FEV1 (F = 1.122, 0.028, 0.06, 2.483; p > 0.05, respectively). Intragroup analysis revealed changes in PEF compared to baseline in the ASG (F = 5.895; p < 0.05). Increases were observed in all strength parameters for both training programs.

CONCLUSIONS

The concurrent training effect on muscle composition, oxygen consumption and muscle strength specifically 1RM, in middle-aged individuals are equivocal, regardless of the exercise order. The results indicate that both exercise sequences can elicit similar benefits in terms of cardiovascular fitness, muscular strength, and endurance. This lack of difference suggests that the order of exercise does not play a significant role in determining the effectiveness of the workout or the subsequent physiological adaptations. CLINICALTIALS.

GOV IDENTIFIER

NCT05862415. Date of registration: 04/25/2023.

Fat deposition, fatty acid profiles, antioxidant capacity and differentially expressed genes in subcutaneous fat of Tibetan sheep fed wheat-based diets with and without xylanase supplementation

Xylanase, an exogenous enzyme that plays an essential role in energy metabolism by hydrolysing xylan into xylose, has been shown to positively influence nutrient digestion and utilisation in ruminants. The objective of this study was to evaluate the effects of xylanase supplementation on the back-fat thickness, fatty acid profiles, antioxidant capacity, and differentially expressed genes (DEGs) in the subcutaneous fat of Tibetan sheep. Sixty three-month-old rams with an average weight of 19.35 ± 2.18 kg were randomly assigned to control (no enzyme added, WH group) and xylanase (0.2% of diet on a dry matter basis, WE group) treatments. The experiment was conducted over 97 d, including 7 d of adaption to the diets. The results showed that xylanase supplementation in the diet increased adipocyte volume of subcutaneous fat (p < 0.05), shown by hematoxylin and eosin (H&E) staining. Gas chromatography showed greater concentrations of C14:0 and C16:0 in the subcutaneous fat of controls compared with the enzyme-treated group (p < 0.05), while opposite trend was seen for the absolute contents of C18:1n9t, C20:1, C18:2n6c, C18:3, and C18:3n3 (p < 0.05). Compared with controls, supplementation with xylanase increased the activity of T-AOC significantly (p < 0.05). Transcriptomic analysis showed the presence of 1630 DEGs between the two groups, of which 1023 were up-regulated and 607 were down-regulated, with enrichment in 4833 Gene Ontology terms, and significant enrichment in 31 terms (p < 0.05). The common DEGs were enriched in 295 pathways and significantly enriched in 26 pathways. Additionally, the expression of lipid-related genes, including fatty acid synthase, superoxide dismutase, fatty acid binding protein 5, carnitine palmytoyltransferase 1 A, and peroxisome proliferator-activated receptor A were verified via quantitative reverse-transcription polymerase chain reaction. In conclusion, dietary xylanase supplementation was found to reduce subcutaneous fat deposition in Tibetan sheep, likely through modulating the expression of lipid-related genes.

COVID-19 infection analysis framework using novel boosted CNNs and radiological images

COVID-19, a novel pathogen that emerged in late 2019, has the potential to cause pneumonia with unique variants upon infection. Hence, the development of efficient diagnostic systems is crucial in accurately identifying infected patients and effectively mitigating the spread of the disease. However, the system poses several challenges because of the limited availability of labeled data, distortion, and complexity in image representation, as well as variations in contrast and texture. Therefore, a novel two-phase analysis framework has been developed to scrutinize the subtle irregularities associated with COVID-19 contamination. A new Convolutional Neural Network-based STM-BRNet is developed, which integrates the Split-Transform-Merge (STM) block and Feature map enrichment (FME) techniques in the first phase. The STM block captures boundary and regional-specific features essential for detecting COVID-19 infectious CT slices. Additionally, by incorporating the FME and Transfer Learning (TL) concept into the STM blocks, multiple enhanced channels are generated to effectively capture minute variations in illumination and texture specific to COVID-19-infected images. Additionally, residual multipath learning is used to improve the learning capacity of STM-BRNet and progressively increase the feature representation by boosting at a high level through TL. In the second phase of the analysis, the COVID-19 CT scans are processed using the newly developed SA-CB-BRSeg segmentation CNN to accurately delineate infection in the images. The SA-CB-BRSeg method utilizes a unique approach that combines smooth and heterogeneous processes in both the encoder and decoder. These operations are structured to effectively capture COVID-19 patterns, including region-homogenous, texture variation, and border. By incorporating these techniques, the SA-CB-BRSeg method demonstrates its ability to accurately analyze and segment COVID-19 related data. Furthermore, the SA-CB-BRSeg model incorporates the novel concept of CB in the decoder, where additional channels are combined using TL to enhance the learning of low contrast regions. The developed STM-BRNet and SA-CB-BRSeg models achieve impressive results, with an accuracy of 98.01%, recall of 98.12%, F-score of 98.11%, Dice Similarity of 96.396%, and IOU of 98.85%. The proposed framework will alleviate the workload and enhance the radiologist's decision-making capacity in identifying the infected region of COVID-19 and evaluating the severity stages of the disease.

Different Continuous Training Intensities Improve Echocardiographic Parameters, Quality of Life, and Functional Capacity in Heart Failure Patients with Reduced Ejection Fraction

Background

Multiple comorbidities and physiological changes play a role in a range of heart failure conditions and influence the most effective approach to exercise-based rehabilitation. This research aimed to examine and compare the outcomes of continuous training at three different intensities, focusing on left ventricular (LV) remodeling, functional capacity, and quality of life among patients with heart failure with reduced ejection fraction (HFrEF).

Methods

In this randomized control trial, a total of 60 male patients (average age: 54.33 ±2.35 years) with HFrEF were randomly allocated into three groups: 1) High-intensity continuous training group (HICT), 2) Moderate-intensity continuous training group (MICT), and 3) Low-intensity continuous training group (LICT). All the training was performed on a bicycle ergometer 3 times/week for 12 weeks. Echocardiographic parameters (left ventricular ejection fraction, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, N-terminal pro-B-type natriuretic peptide (NT-proBNP), quality of life (Minnesota Living with Heart Failure Questionnaire), and functional capacity (6-minute walking test) were assessed before and the end of the study.

Results

The HICT group demonstrated the greatest improvements in all measured variables when compared to the other two groups (P < 0.05). These findings were consistent across all measured outcomes.

Conclusion

It was determined that HICT appears to yield the most favorable outcomes in enhancing echocardiographic measures, NT-proBNP levels, quality of life, and functional capacity among HFrEF patients.

Exploring the Influence of the Coronavirus Disease 2019 Pandemic on the Accessibility of Rehabilitation Services Provided to Children with Disabilities: A Cross-Sectional Study

Background and Objectives: Children with disabilities (such as cerebral palsy, autistic spectrum disorder, and Down syndrome) are the most vulnerable and marginalized subset of the population, representing 2.7% of the total population of Saudi Arabia. The COVID-19 outbreak might have disproportionately affected children with disabilities, augmented their isolation, and induced severe disruptions to the services on which these children rely. Limited research has been conducted in Saudi Arabia to understand the impact of the COVID-19 pandemic on the rehabilitation services provided to children with disabilities and barriers. This study aimed to investigate the effect of the lockdown implemented as a result of the coronavirus disease-2019 (COVID-19) pandemic on the accessibility of rehabilitation services, including communication, occupational therapy, and physical therapy, in Riyadh, Kingdom of Saudi Arabia. Materials and Methods: In this cross-sectional study, a survey was conducted between June and September 2020 during the lockdown in Saudi Arabia. A total of 316 caregivers of children with disabilities from Riyadh participated in the study. The accessibility of rehabilitation services provided to children with disabilities was assessed by designing a valid questionnaire. Results: A total of 280 children with disabilities received rehabilitation services before the COVID-19 pandemic and showed improvement following therapeutic sessions. However, during the pandemic, most children stopped receiving therapeutic sessions because of lockdown, which deteriorated their condition. This shows a significant reduction in the accessibility of the rehabilitation services provided during the pandemic. Conclusions: The findings of this study revealed a drastic decline in services provided to children with disabilities. This caused a notable deterioration in the abilities of these children.

Does COVID-19 Policy Affect Initiation and Duration of Exclusive Breastfeeding? A Single-center Retrospective Study

Purpose

It assessed the effect of a COVID-19 policy that involved maternal-neonatal separation on early initiation and duration of exclusive breastfeeding (EBF) at two weeks, three, and six months postpartum during the peak of the COVID-19 pandemic in 2020.

Patients and Methods

This retrospective study included consecutive mother-newborn dyads with deliveries between mid-March and the end of December 2020 who agreed to participate and were eligible according to the following criteria: full-term pregnancy, singleton birth, and healthy newborn. Participants were called at least twice during the study period to inquire about exclusive breastfeeding status at two weeks, three, and six months postpartum. Multivariate logistic regression analysis was carried out to identify associated factors with EBF.

Results

A total of 454 eligible mother-infant dyads were included. Mean maternal age (in years), gestational age (in weeks), birth weight (in kilograms), and 5-min Apgar score was, respectively, 32±5.4 years, 39±1.3 weeks, 3.1±0.42 kg, and 9.24±0.6. Most of the mothers (86.1%) had no known chronic diseases and had a normal spontaneous vaginal delivery (NSVD, 91.4%). Approximately 44.7% of the sample initiated breastfeeding either directly or with expressed breastmilk during their hospital stay. Prevalence of EBF during the first two weeks, three, and six months postpartum was, respectively, 30%, 19.8%, and 31.7%. EBF was associated with birth weight, hospital breastfeeding and EIBF at early postpartum period, while EBF at six months was associated with parity and method of delivery.

Conclusion

During the peak of the COVID-19 pandemic, the prevalence of breastfeeding initiation and EBF in the first six months postpartum were low among Saudi mothers. However, multicenter, prospective, cohort studies with adjustment for known confounding factors are required to explore the impact of infection control policies on breastfeeding. Meanwhile, these policies should support early and safe breastfeeding practices, especially with new and evolving information regarding the current pandemic.