The diagnostic performance of AI-based algorithms to discriminate between NMOSD and MS using MRI features: A systematic review and meta-analysis.

BACKGROUND: Magnetic resonance imaging [MRI] findings in Neuromyelitis optica spectrum disorder [NMOSD] and Multiple Sclerosis [MS] patients could lead us to discriminate toward them. For instance, U-fiber and Dawson's finger-type lesions are suggestive of MS, however linear ependymal lesions raise the possibility of NMOSD. Recently, artificial intelligence [AI] models have been used to discriminate between NMOSD and MS based on MRI features. In this study, we aim to systematically review the capability of AI algorithms in NMOSD and MS discrimination based on MRI features. METHOD: We searched PubMed, Scopus, Web of Sciences, Embase, and IEEE databases up to August 2023. All studies that used AI-based algorithms to discriminate between NMOSD and MS using MRI features were included, without any restriction in time, region, race, and age. Data on NMOSD and MS patients, Aquaporin-4 antibodies [AQP4-Ab] status, diagnosis criteria, performance metrics (accuracy, sensitivity, specificity, and AUC), artificial intelligence paradigm, MR imaging, and used features were extracted. This study is registered with PROSPERO, CRD42023465265. RESULTS: Fifteen studies were included in this systematic review, with sample sizes ranging between 53 and 351. 1,362 MS patients and 1,118 NMOSD patients were included in our systematic review. AQP4-Ab was positive in 94.9% of NMOSD patients in 9 studies. Eight studies used machine learning [ML] as a classifier, while 7 used deep learning [DL]. AI models based on only MRI or MRI and clinical features yielded a pooled accuracy of 82% (95% CI: 78-86%), sensitivity of 83% (95% CI: 79-88%), and specificity of 80% (95% CI: 75-86%). In subgroup analysis, using only MRI features yielded an accuracy, sensitivity, and specificity of 83% (95% CI: 78-88%), 81% (95% CI: 76-87%), and 84% (95% CI: 79-89%), respectively. CONCLUSION: AI models based on MRI features showed a high potential to discriminate between NMOSD and MS. However, heterogeneity in MR imaging, model evaluation, and reporting performance metrics, among other confounders, affected the reliability of our results. Well-designed studies on multicentric datasets, standardized imaging and evaluation protocols, and detailed transparent reporting of results are needed to reach optimal performance.

3D metamaterial ultra-wideband absorber for curved surface.

This paper proposes a three-dimensional metamaterial absorber based on a resistive film patch array to develop a low-cost, lightweight absorber for curved surfaces. An excellent absorption over a large frequency band is achieved through two different yet controllable mechanisms; in the first mechanism, a considerable attenuation in the wave power is achieved via graphite resistive films. The absorption is then intensified through magnetic dipoles created by the surface currents, leading to absorption peaks. The simulation results of the absorber show that a broadband absorption greater than 85% is achieved over 35-400 GHz for both TE and TM polarization waves at normal incidence. The structure has more than 167% and 80% absorption bandwidth above 85% and 90%, respectively. It is shown that the proposed metamaterial absorber is independent of incident wave polarization. In addition, the structure is insensitive to incident angles up to 60° for TE mode and full range angle 90° for TM mode. To describe the physical mechanism of the absorber, E-field, power loss density and surface current distributions on the structure are calculated and shown. Moreover, the oblique incidence absorption efficiency is also explained. This absorber paves the way for practical applications, such as sensing, imaging and stealth technology. In addition, the proposed structure can be extended to terahertz, infrared and optical regions.

Assessing Acute Responses to Exercises Performed Within and at the Upper Boundary of Severe Exercise Domain.

Purpose: The highest work-rate that provides maximal oxygen uptake (V˙O2max) may be one of the best exercise stimuli to yield both V˙O2max and lactate accumulation. The aim of this study was to analyze physiological and metabolic acute responses of an exercise modality performed at the upper boundary of the severe exercise domain, and compare those responses with exercise modalities applied within the severe exercise domain. Method: Ten trained male cyclists participated in this study. The V˙O2max, corresponding power output (POVO2max), and the highest work-rate that provides the V˙O2max (IHIGH) were determined by constant work-rate exercises. Cyclists performed three high-intensity interval training (HIIT) strategies as follows; HIIT-1: 4-6 × 3-min at 95% of POVO2max with 1:1 (workout/rest ratio); HIIT-2: 16-18 × 1-min at 105% of POVO2max with 1:1; HIIT-3: 4-7 × 1-2-min at the IHIGH with 1:2. Capillary blood samples were analyzed before, immediately after HIIT sessions, and at the first, third, and fifth minutes of recovery periods. Lactate difference between the highest lactate response and resting status was considered as the peak lactate response for each HIIT modality. Results: Time spent at V˙O2max was greater at HIIT-1 and HIIT-3 (272 ± 127 and 208 ± 111 seconds, respectively; p = 0.155; effect size = 0.43) when compared to the HIIT-2 (~26 seconds; p < 0.001), while there was a greater lactate accumulation at HIIT-3 (~16 mmol·L-1) when compared to HIIT-1 and HIIT-2 (12 and 14 mmol·L-1, respectively; p < 0.001). Conclusions: In conclusion, HIIT-3 performed at IHIGH was successful to provide time spent at V˙O2max with a greater lactate accumulation in a single session.

Grey Zone: A Gap Between Heavy and Severe Exercise Domain.

ABSTRACT: Ozkaya, O, Balci, GA, As, H, Cabuk, R, and Norouzi, M. Grey zone: A gap between heavy and severe exercise domain. J Strength Cond Res 36(1): 113-120, 2022-The aim of this study was to determine a critical threshold (CT) interpreted as "the highest exercise intensity where V̇o2 can be stabilized before reaching 95% of V̇o2max (V̇o2peak)" and compare it with commonly used anaerobic threshold indices. Ten well-trained male cyclists volunteered for this study. Ventilatory threshold (VT) was determined from incremental tests. Multisession constant-load trials were performed to reveal V̇o2max. Mathematically modeled critical power (CP) was estimated through the best individual fit parameter method. Maximal lactate steady state (MLSS) was detected by 30-minute constant-load exercises. The individual CT load of each cyclist was tested by constant-load exercises to exhaustion with +15 W intervals until minimal power output to elicit V̇o2peak. The results showed that work rate corresponding to CT (329.5 ± 41.5 W) was significantly greater than that of the MLSS (269.5 ± 38.5 W; p = 0.000), VT (279.6 ± 33 W; p = 0.000), and CP (306.3 ± 39.4 W; p = 0.000), and CP overestimated both VT and MLSS (p = 0.000). There was no significant V̇o2 difference between the 10th and 30th minute of MLSS and MLSS + 15 W exercise (0.36-0.13 ml·min-1·kg-1; p = 0.621). Exercising V̇o2 response of MLSS + 15 W could not exceed the level of 95% V̇o2max (57.02 ± 3.87 ml·min-1·kg-1 and 87.2 ± 3.1% of V̇o2max; p = 0.000), whereas V̇o2 responses greater than 95% of V̇o2max were always attained during exercises performed at CT + 15 W (64.52 ± 4.37 ml·min-1·kg-1 and 98.6 ± 1% of V̇o2max; p > 0.05). In conclusion, this study indicates that there is a "grey zone" between heavy and severe exercise domain. This information may play a key role in enhancing athletic performance by improving the quality of training programs.

Recent advances on nanomaterials-based fluorimetric approaches for microRNAs detection.

MicroRNAs are types of small single-stranded endogenous highly conserved non-coding RNAs, which play main regulatory functions in a wide range of cellular and physiological events, such as proliferation, differentiation, neoplastic transformation, and cell regeneration. Recent findings have proved a close association between microRNAs expression and the development of many diseases, indicating the importance of microRNAs as clinical biomarkers and targets for drug discovery. However, due to a number of prominent characteristics like small size, high sequence similarity and low abundance, sensitive and selective identification of microRNAs has rather been a hardship through routine traditional assays, including quantitative polymerase chain reaction, microarrays, and northern blotting analysis. More recently, the soaring progression in nanotechnology and fluorimetric methodologies in combination with nanomaterials have promised microRNAs detection with high sensitivity, efficiency and selectivity, excellent reproducibility and lower cost. Therefore, this review will represent an overview of latest advances in microRNAs detection through nanomaterials-based fluorescent methods, like gold nanoparticles, silver and copper nanoclusters, graphene oxide, and magnetic silicon nanoparticles.

Mutational analysis of HBs Ag-positive mothers and their infected children despite immunoprophylaxis.

Hepatitis B vaccination is safe and effective, although breakthrough infection occasionally occurs in those who receive the vaccine and hepatitis B immunoglobulin (HBIg) prophylaxis. Sequence variation in their antigenic regions is one of the most powerful strategies that are used by viruses to escape recognition by B and T cell-mediated immune responses. The aim of this study was to explore the mutational profile of HBV in vertical transmission.Six HBsAg-positive mothers and their children who developed HBV infection despite immunoprophylaxis were enrolled. After extraction of HBV DNA from sera, the full HBV genome or surface gene was amplified by Gunther and hemi-nested PCR, respectively. After sequencing, the mutational analysis on paired samples between mothers and children were carried out and compared.Different mutations were found in four children, at least, one arose in functional and/or immune epitope activities. Of 30 amino acid changes, 11 (36.6%) were located within the known HBV immune epitopes. In three children, mutations occurred within the "a" determinant region, one mutation (B2) was identical to the mother of patient, an indication of vertical transmission. The other two (B4 and B5) were considered as vaccine escape mutations. Three children harbored wild-type HBsAg, similar to their mothers. Regarding transmission in infected children, the immunoprophylaxis had no effect and failure of vaccination was observed in 2 isolates.These findings emphasized the need for an alternative regimen, such as the administration of boosters or a more effective HBV vaccine for high-risk children who are born to HBsAg-positive mothers.