Analysis Of Asymmetry Research Articles

Step-Wise Parameter Adaptive FMD Incorporating Clustering Algorithm in Rolling Bearing Compound Fault Diagnosis

Ideally, the vibration signal of a rolling bearing should be symmetrical. However, in practical operation, the vibration signals in both time and frequency domains often exhibit asymmetry due to factors such as load, speed, and wear. The relatively weak composite fault characteristics are easily masked. Although the Feature Modal Decomposition (FMD) method is outstanding in diagnosing composite faults in bearings, its effectiveness is easily constrained by parameter selection. To address this, this paper proposes a stepwise parameter adaptive FMD method combined with a clustering algorithm, specifically designed for diagnosing composite faults in rolling bearings. Firstly, this study employs the Density Peak Clustering algorithm to determine the number of modes n in the composite fault vibration signal. Subsequently, considering the signal spectral energy and modal characteristics, a new composite fault index is formulated, namely, the adaptive weighted frequency domain kurtosis-to-information entropy ratio, as the fitness function. The Whale Optimization Algorithm determines the filter length L and the number of segments K, thereby achieving step-wise signal decomposition. Through in-depth analysis of signal symmetry and asymmetry, simulation and experimental verification confirm the effectiveness of this method. Compared with four other index-optimized FMD methods and traditional techniques, this method significantly reduces the influence of parameters on FMD, is capable of separating the characteristic frequencies related to composite faults, and performs excellently in the diagnosis of composite faults in rolling bearings.

Sensitive Detection of Hg2+ and l-Cysteine through Optical Asymmetry-Tuned Fluorescence Switch Off-On Behavior in N-Doped Chiral Carbon Dot.

Blue-emissive nitrogen-doped chiral carbon dots (d-NCD230 and l-NCD230) exhibiting antipodal chiroptical activity, synthesized from the thermal pyrolysis of citric acid and d/l-aspartic acid in 1:2 molar ratios, have been explored as chirality-based fluorescent turn-off/on probes for the detection of Hg2+ and l-cysteine (l-Cys). Circular dichroism (CD) spectroscopy revealed that the chiroptical activity originates from a synergy among intrinsic chirality, chiral precursors on the NCD surface, and hybridization of lower energy levels within the embedded chiral chromophore. Quantitative analysis of optical asymmetry using the Kuhn asymmetry factor (g) at the CD signal of 312 nm showed a higher value for d-NCD230 (1.03 × 10-4) compared to l-NCD230 (1.13 × 10-5). Moreover, we have demonstrated chirality transfer and chiral inversion phenomena in d/l-NCDs by preparing carbon dots with different precursor ratios at different temperatures and probing them through CD spectroscopy. The NCDs exhibited selective fluorescence quenching in the presence of Hg2+, demonstrating linearity in the Stern-Volmer plot. Limits of detection (LODs) for Hg2+ were calculated to be 129 and 192 nM for d-NCD230 and l-NCD230, respectively, in the 0-150 μM concentration range. The quenching mechanism involves nonradiative electron transfer due to Hg2+ binding to oxygen-rich functional groups on the d/l-NCD230 surface. The slight variation in LOD values between d-NCD230 and l-NCD230 indicates the negligible effect of the chirality on Hg2+ sensing. Notably, the fluorescence intensity of d/l-NCD230 could be restored upon adding l-cysteine, with d-NCD230 showing a more pronounced enhancement than l-NCD230. This differential response is attributed to a preferential stereoselective interaction arising from the homochirality of d-NCD230/Hg2+ and l-cysteine. These findings demonstrate the potential of chiral nitrogen-doped carbon dots as sensitive and selective probes for Hg2+ and l-cysteine, with implications for environmental monitoring and biological sensing applications.

Amide proton transfer-weighted CEST MRI for radiotherapy target delineation of glioblastoma: a prospective pilot study

BackgroundExtensive glioblastoma infiltration justifies a 15-mm margin around the gross tumor volume (GTV) to define the radiotherapy clinical target volume (CTV). Amide proton transfer (APT)-weighted imaging could enable visualization of tumor infiltration, allowing more accurate GTV delineation. We quantified the impact of integrating APT-weighted imaging into GTV delineation of glioblastoma and compared two APT-weighted quantification methods—magnetization transfer ratio asymmetry (MTRasym) and Lorentzian difference (LD) analysis—for target delineation.MethodsNine glioblastoma patients underwent an extended imaging protocol prior to radiotherapy, yielding APT-weighted MTRasym and LD maps. From both maps, biological tumor volumes were generated (BTVMTRasym and BTVLD) and added to the conventional GTV to generate biological GTVs (GTVbio,MTRasym and GTVbio,LD). Wilcoxon signed-rank tests were performed for comparisons.ResultsThe GTVbio,MTRasym and GTVbio,LD were significantly larger than the conventional GTV (p ≤ 0.022), with a median volume increase of 9.3% and 2.1%, respectively. The GTVbio,MTRasym and GTVbio,LD were significantly smaller than the CTV (p = 0.004), with a median volume reduction of 72.1% and 70.9%, respectively. There was no significant volume difference between the BTVMTRasym and BTVLD (p = 0.074). In three patients, BTVMTRasym delineation was affected by elevated signals at the brain periphery due to residual motion artifacts; this elevation was absent on the APT-weighted LD maps.ConclusionLarger biological GTVs compared to the conventional GTV highlight the potential of APT-weighted imaging for radiotherapy target delineation of glioblastoma. APT-weighted LD mapping may be advantageous for target delineation as it may be more robust against motion artifacts.Relevance statementThe introduction of APT-weighted imaging may, ultimately, enhance visualization of tumor infiltration and eliminate the need for the substantial 15-mm safety margin for target delineation of glioblastoma. This could reduce the risk of radiation toxicity while still effectively irradiating the tumor.Trial registrationNCT05970757 (ClinicalTrials.gov).Key PointsIntegration of APT-weighted imaging into target delineation for radiotherapy is feasible.The integration of APT-weighted imaging yields larger GTVs in glioblastoma.APT-weighted LD mapping may be more robust against motion artifacts than APT-weighted MTRasym.Graphical

MORPHOLOGICAL VARIATIONS IN MUD CLAM Polymesoda erosa (Lightfoot) USING FLUCTUATING ASYMMETRY ANALYSIS IN LA UNION, CABADBARAN CITY, AGUSAN DEL NORTE, PHILIPPINES

A geometric morphometric study was conducted on the population of Polymesoda erosa in La Union, Cabadbaran City, to investigate the morphological variations using fluctuating asymmetry (FA) analysis. FA acts as a reliable indicator of ecological stress and developmental instability since it detects genetic or environmental changes that an organism experiences. A total of ninety (90) individual mud clams were randomly collected and analyze. Water and soil samples were also collected to gather data on the degree of body variations and the impact of external factors on P. erosa. The result of the analysis using the SAGE software revealed a highly significant fluctuating asymmetry (P 0.0001). Significant variations in individuals, sides, and the interaction between individuals and sides symmetry were mostly responsible for the substantial variances seen in mud clam species. Particularly, landmarks 10 (dorsal margin maxima) and 13 (anterior margin maxima) exhibited notable variations. For the water quality results, the mud clam's internal valve was likely to be relatively unaffected or minimally impacted, but the level of nickel was high. In conclusion, the fluctuating asymmetry of P. erosa can be attributed to a stressed environment. Unfavorable environmental factors cause an organism's morphology to change, affecting its symmetry.

Influencing factors analysis of asymmetry in knee adduction moment among patients with unilateral knee osteoarthritis

BackgroundThe knee adduction moment(KAM) of both lower limbs in patients with unilateral knee osteoarthritis(KOA) exhibits asymmetry during walking, but the factors influencing this asymmetry remain unclear. This study aimed to explore the influencing factors of KAM asymmetry in patients with unilateral KOA.MethodsA total of 148 patients with unilateral medial compartment KOA were selected for this retrospective study, and general data such as gender, age, and duration of disease were collected. The hip-knee-ankle (HKA) angle, degree of pain, and knee-extension muscle strength on the affected side were assessed through radiographic outcomes, the visual analog scale(VAS), and the Biodex isokinetic system. The peak KAM of both lower limbs was analyzed using a BTS motion-capture system and force platform. The asymmetry index(ASI) of KAM was calculated, and the patients were further categorized into the KAM symmetry group(ASI value ≤ 10%) and the KAM asymmetry group(ASI value>10%).Binary logistic regression analysis was employed to analyze the factors influencing the asymmetry of KAM.Results90 patients were categorized into the KAM asymmetry group, representing 60.8% of the cohort. A significant difference in the ASI value of KAM was observed between the two groups. Correlation analysis identified nine factors, including sex, age, and BMI, that were positively correlated with the ASI value of KAM. In contrast, knee-extension muscle strength and per-capita monthly household income were negatively correlated with the ASI value of KAM. Regression analysis revealed that being female(OR = 1.752), older age(OR = 2.472), increased BMI(OR = 1.535), larger varus angle(OR = 3.965), higher VAS score(OR = 2.617), Kellgren-Lawrence(K-L) grade IV(OR = 4.474), history of knee joint trauma(OR = 5.684), and living in a rural location(OR = 1.554) increased the risk of KAM asymmetry. Conversely, increased knee-extension muscle strength(OR = 0.758) and a per-capita monthly household income of 3000 ~ 6000 yuan(OR = 0.814) decreased the risk of KAM asymmetry.ConclusionFemale gender, older age, increased BMI, larger varus angle, higher VAS score, K-L grade IV, history of knee joint trauma, and living in a rural location are identified as risk factors for KAM asymmetry. Conversely, increased knee-extension muscle strength and a per-capita monthly household income of 3000 ~ 6000 yuan serve as protective factors against this asymmetry.

Outcomes of Figure of Eight Graft Reconstruction of Anterior Sternoclavicular Joint Dislocation: A Systematic Review and Meta-Analysis

Abstract Background A sternoclavicular (SC) joint dislocation is a rare injury, accounting for 1% of all traumatic joint dislocations. Dislocation of the SCJ is a rare injury and typically requires high- energy forces applied directly or indirectly to the joint. Although anterior sternoclavicular dislocations are more common because of the strength of the posterior joint capsule, posterior sternoclavicular dislocations tend to be more morbid because of the risk of tracheal, esophageal, or neurovascular compression. Even after appropriate treatment of the initial dislocation, patients can occasionally have persistent SCJ instability that may present as pain and scapular dyskinesia. Objective To perform a systematic review on results of reconstruction of anterior sternoclavicular joint dislocation via figure of eight graft, aiming at highlighting clinical and functional outcomes of this technique. Patients and Methods This is a systematic review study and meta-analysis on human subjects studied in different literatures collected from different medical websites up to December 2022 that dealing with the reconstruction of anterior sternoclavicular joint dislocation via figure of eight graft, aiming at highlighting clinical and functional outcomes of this technique. The study was performed in the Orthopedic Surgery Department, Faculty of Medicine, Ain Shams University along the period from August 2022 to January 2023. Results The meta-analysis for postoperative complications showed non-significant difference (P = 0.068). This indicated that this technique had low risk of complications. Forest plot and pooling of data using random-effects method (REM) with 95% CI found minor heterogeneity (I2 = 38.4%) non- significant difference (p > 0.05) in complications of this operative technique. The funnel plot for postoperative complications found no evidence of publication bias with symmetrical funnel plot. Rank correlation test and regression analysis for funnel plot asymmetry was insignificant (r = 0.0852, p = 0.068) for postoperative complication of anterior sternoclavicular joint dislocation operated by 8-shaped autologous graft. Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2020. Conclusion SC joint reconstruction, using a gracilis graft, results in a prolonged improvement in shoulder function in most patients with symptomatic chronic anterior SC instability. The technique aims at reducing the risk of serious vascular and functional complications, but extreme care is still needed during the procedure.

Static analysis of violin bow behavior under playing loads.

After discussing the relationship between taper and camber typically used by bowmakers, energy methods are then employed to develop nonlinear boundary value problems describing both the hair tightening problem and static deflection analysis of the violin bow under playing loads, including an analysis of possible hair tension asymmetry by employing a linear springs in series model of the hair. A simple algebraic condition for the distance the frog travels in reaching maximum tension is also presented. Boundary value problems are then applied using tools in scilab, comparing the idealized Tourte taper exhibiting a linear stiffness profile and an alternative design with a significantly different profile, revealing small differences in their behavior under static playing loads and validating previously observed significant increase in hair tension when approaching the tip. While the difference in vertical hair deflection as a function of bow position is extremely small, the Tourte design exhibits somewhat more compliance in the stick when approaching the tip, possibly desirable by players given increasing hair tension. An interesting small loss of hair tension in the lower section of the bow stroke is also discussed, representing additional slight differences in the initial compliance felt by the player when engaging the strings.

WingAnalogy: a computer vision-based tool for automated insect wing asymmetry and morphometry analysis

WingAnalogy is a computer tool for automated insect wing morphology and asymmetry analysis. It facilitates project management, enabling users to import pairs of wing images obtained from individual insects, such as left and right, fore- and hindwings. WingAnalogy employs image processing and computer vision to segment wing structures and extract cell boundaries, and junctions. It quantifies essential metrics encompassing cell and wing characteristics, including area, length, width, circularity, and centroid positions. It enables users to scale and superimpose wing images utilizing Particle Swarm Optimization (PSO). WingAnalogy computes regression, Normalized Root Mean Square Error (NRMSE), various cell-based parameters, and distances between cell centroids and junctions. The software generates informative visualizations, aiding researchers in comprehending and interpreting asymmetry patterns. WingAnalogy allows for dividing wings into up to five distinct wing cell sets, facilitating localized comparisons. The software excels in report generation, providing detailed asymmetry measurements in PDF, CSV, and TXT formats.

Stock Market Development and Environmental Sustainability in Saudi Arabia: Asymmetry Analysis

Stock Market Development (SMD) can have positive or negative environmental effects by providing the capital to clean or dirty production processes, respectively. The present study investigates the effect of SMD on CO2 emissions in Saudi Arabia from 1985 to 2022 by conducting symmetrical and asymmetrical analyses. The results validate the environmental Kuznets curve in both symmetrical and asymmetrical analyses. The turning point of the curve is found at 61500 SR and 49944 of income per capita in symmetrical and asymmetrical analyses, respectively, in the long run. The turning points are found at 65895 SR and 54979 SR in the symmetrical and asymmetrical models, respectively, in the short run. All points are within the range of sample period’s income. Thus, Saudi economic growth has no environmental problems. Moreover, SMD and increasing SMD help reduce CO2 emissions in the long run with elasticity parameters 0.8548 and 0.9854 in symmetrical and asymmetrical models, respectively. Thus, SMD should further be focused to have pleasant environmental effects in Saudi Arabia.

Analysis of kinetic asymmetry in a multi-cycle reaction network establishes the principles for autonomous compartmentalized molecular ratchets

Analysis of kinetic asymmetry in a multi-cycle reaction network establishes the principles for autonomous compartmentalized molecular ratchets

Selective editing for asymmetry analysis in intra-EU trade Micro-Data Exchange (MDE)

Since January 2022, the Regulation on European Business Statistics (EU 2019/2152) requires EU Member States to compulsorily share microdata on intra-EU exports. Establishing intra-EU export Micro-Data Exchange (MDE) provides National Statistical Institutes with a new data source to compile intra-EU import statistics. The availability of MDE tackles two key challenges: diminishing the overall response burden on data providers and meeting user expectations regarding the quality of the produced statistics. However, transitioning to a data production system based on MDE data requires the assessment of the coherence and comparability between MDE and National import data. To identify asymmetries between the two data sources, Istat developed an innovative application designed to foster cooperation among Member States. The tool was developed using the Shiny package in R. The implemented solution allows users to perform exploratory analysis, systematic error detection, and selective editing. The most relevant asymmetries are identified through relative contribution and the asymmetry suspicion indices assessed by user-defined thresholds. Sharing the open tool within the European Statistical System enhances interoperability, promotes method harmonization, and encourages the adoption of official statistical standards.

A task-dependent analysis of closed vs. open and fine vs. gross motor skills in handedness

ABSTRACT The traditional classifications of motor skills nature (open vs closed; fine vs gross) have not been considered in handedness investigations. Instead, previous research focused on comparing complex vs less complex motor behaviour, leaving a gap in the literature. We compared manual preference between different motor skill characteristics, namely: fine and closed (FC), gross and closed (GC) and gross and open (GO) tasks. The hand preference was assessed with the Global Lateral Preference Inventory in four hundred and forty participants (244 women) aged from 18 to 59 years old. By assessing the degree and direction of handedness in different motor skills, our results showed a stronger lateralization pattern for FC motor skills as compared to GC and GO, with GO also being less lateralized than GC. Our results expand those of previous investigations that used the motor skill complexity definitions by showing how handedness can also be modulated by the interaction between classic motor skills classifications. Future research should consider fine vs. gross and open vs. closed classifications when selecting tasks for analysis of asymmetries of preference.

Analysis of functional network asymmetry in major depressive disorder under four fNIRS tasks

BackgroundResearch in functional asymmetry of Major Depressive Disorder (MDD) under different tasks is crucial for clinical diagnose. MethodsFifty individuals with MDD and twenty healthy controls (HCS) were recruited for hemodynamic data collection under four fNIRS tasks (Emotional picture, Verbal fluency, Fingering and Negative emotional picture description task). Integral values and functional connectivity strength were employed to probe neural activation and functional connectivity in frontal and temporal lobes in MDD. Following, asymmetry characteristic of the frontal cortex between MDD and HCS under four tasks were carefully analyzed and compared. ResultsIndividuals with MDD demonstrated heightened connectivity between the frontal and right temporal lobes and reduced connectivity between the frontal and left temporal lobes compared to HCS in all tasks. Additionally, MDD exhibited attenuated activation in the left frontal lobes and exaggerated activation in the right frontal lobes, diverging from HCS. Furthermore, the disparities in left-right asymmetry characteristic of frontal cortex activation between MDD and HCS were more pronounced during the combined task. LimitationsFurther research is required to grasp the neurophysiological mechanisms governing left-right asymmetry across various tasks and the influence of task-induced brain fatigue on cerebral cortex hemodynamics in MDD. ConclusionThe left-right asymmetry feature provides valuable neurophysiological insights for diagnosing MDD clinically. Variations in activation patterns and functional connectivity features between MDD and HCS are closely tied to the task chosen. Thus, in clinical practice, carefully selecting appropriate fNIRS tasks and relevant features can significantly improve the diagnostic accuracy of MDD.

Validity of the Pneumonitor for Analysis of Short-Term Heart Rate Asymmetry Extended with Respiratory Data in Pediatric Cardiac Patients.

Background: Wearable technologies have been developed to measure physiological parameters conveniently. To consider the new measurement device valid, the crucial point is to assess its reliability with the gold standard. The study aimed to assess the validity of the Pneumonitor (PM, fs = 250 Hz) for acquisition of 5 min RR intervals (RRi) for analysis of heart rate asymmetry (HRA) in relation to the electrocardiography (ECG, fs = 1000 Hz) in a group of 19 pediatric cardiac patients. Association between HRA and respiratory rate (RespRate) was verified. Methods: The validation comprised Bland-Altman analysis, intraclass correlation coefficient, and Student's t-test. Results: Sufficient agreement between 10 from 16 HRA parameters was observed. Different HRA parameters values calculated based on RRi from both devices were related to different results of correlation analysis between two parameters and RespRate. Conclusions: The PM might be considered valid for recording RRi, which are then processed to calculate selected HRA parameters in a group of pediatric cardiac patients in rest condition. However, RRi recorded using devices with fs < 250 Hz may be not adequate for reliable HRA analysis.

Amide proton transfer MR imaging in the characterization of brain tumors: A review paper

Amide proton transfer (APT) magnetic resonance imaging (MR) is a new imaging technology that has shown promise in the non-invasive characterization of brain malignancies, particularly meningiomas and glioblastomas. Th works aims to evaluate the existing literature in Amide proton transfer (APT) magnetic resonance imaging (MR) to explore the efficacy of APT MR imaging in the characterization of meningiomas and glioblastomas tumors. The review gives an overview of APT MR imaging principles, examines its potential benefits and limits, and highlights the important findings from the selected research. To discover relevant research published up to the current day, a literature search was undertaken in electronic databases such as PubMed and Google Scholar. The search is based on keywords and medical terms related to APT MR imaging, meningiomas, and glioblastomas. The review gives an overview of APT MR imaging principles, examines its potential benefits and limits, and highlights the important findings from the selected research. It showed that the majority of studies found encouraging results in distinguishing meningiomas and glioblastomas from surrounding normal brain tissue using APT MR imaging. For tumor characterization, APT signal intensity assessments such as APT asymmetry analysis and APT ratio analysis were used. The work concluded that the Amide proton transfer MR imaging has the potential to be a non-invasive imaging method for the diagnosis of meningiomas and glioblastomas. It provides useful information about tumor metabolism and cellular composition, which can help with diagnosis, therapy planning, and prognosis.

Large-scale analysis of structural brain asymmetries during neurodevelopment: Associations with age and sex in 4265 children and adolescents.

Only a small number of studies have assessed structural differences between the two hemispheres during childhood and adolescence. However, the existing findings lack consistency or are restricted to a particular brain region, a specific brain feature, or a relatively narrow age range. Here, we investigated associations between brain asymmetry and age as well as sex in one of the largest pediatric samples to date (n = 4265), aged 1-18 years, scanned at 69 sites participating in the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) consortium. Our study revealed that significant brain asymmetries already exist in childhood, but their magnitude and direction depend on the brain region examined and the morphometric measurement used (cortical volume or thickness, regional surface area, or subcortical volume). With respect to effects of age, some asymmetries became weaker over time while others became stronger; sometimes they even reversed direction. With respect to sex differences, the total number of regions exhibiting significant asymmetries was larger in females than in males, while the total number of measurements indicating significant asymmetries was larger in males (as we obtained more than one measurement per cortical region). The magnitude of the significant asymmetries was also greater in males. However, effect sizes for both age effects and sex differences were small. Taken together, these findings suggest that cerebral asymmetries are an inherent organizational pattern of the brain that manifests early in life. Overall, brain asymmetry appears to be relatively stable throughout childhood and adolescence, with some differential effects in males and females.

Development and Validation of Four Different Methods to Improve MRI-CEST Tumor pH Mapping in Presence of Fat.

CEST-MRI is an emerging imaging technique suitable for various in vivo applications, including the quantification of tumor acidosis. Traditionally, CEST contrast is calculated by asymmetry analysis, but the presence of fat signals leads to wrong contrast quantification and hence to inaccurate pH measurements. In this study, we investigated four post-processing approaches to overcome fat signal influences and enable correct CEST contrast calculations and tumor pH measurements using iopamidol. The proposed methods involve replacing the Z-spectrum region affected by fat peaks by (i) using a linear interpolation of the fat frequencies, (ii) applying water pool Lorentzian fitting, (iii) considering only the positive part of the Z-spectrum, or (iv) calculating a correction factor for the ratiometric value. In vitro and in vivo studies demonstrated the possibility of using these approaches to calculate CEST contrast and then to measure tumor pH, even in the presence of moderate to high fat fraction values. However, only the method based on the water pool Lorentzian fitting produced highly accurate results in terms of pH measurement in tumor-bearing mice with low and high fat contents.

Hippocampal Glutamate Levels and Their Correlation With Subregion Volume in School-Aged Children With MRI-Negative Epilepsy: A Preliminary Study.

Abnormal levels of glutamate constitute a key pathophysiologic mechanism in epilepsy. The use of glutamate chemical exchange saturation transfer (GluCEST) imaging to measure glutamate levels in pediatric epilepsy is rarely reported in research. To investigate hippocampal glutamate level variations in pediatric epilepsy and the correlation between glutamate and hippocampal subregional volumes. Cross-sectional, prospective. A total of 38 school-aged pediatric epilepsy patients with structurally normal MRI as determined by at least two independent radiologists (60% males; 8.7 ± 2.5 years; including 20 cases of focal pediatric epilepsy [FE] and 18 cases of generalized pediatric epilepsy [GE]) and 17 healthy controls (HC) (41% males; 9.0 ± 2.5 years). 3.0 T; 3D magnetization prepared rapid gradient echo (MPRAGE) and 2D turbo spin echo GluCEST sequences. The relative concentration of glutamate was calculated through pixel-wise magnetization transfer ratio asymmetry (MTRasym) analysis of the GluCEST data. Hippocampal subfield volumes were computed from MPRAGE data using FreeSurfer. This study used t tests, one-way analysis of variance, Kruskal-Wallis tests, and Pearson correlation analysis. P < 0.05 was considered statistically significant. The MTRasym values of both the left and right hippocampi were significantly elevated in GE (left: 2.51 ± 0.23 [GE] vs. 2.31 ± 0.12 [HCs], right: 2.50 ± 0.22 [GE] vs. 2.27 ± 0.22 [HCs]). The MTRasym values of the ipsilateral hippocampus were significantly elevated in FE (2.49 ± 0.28 [ipsilateral] vs. 2.29 ± 0.16 [HCs]). The MTRasym values of the ipsilateral hippocampus were significantly increased compared to the contralateral hippocampus in FE (2.49 ± 0.28 [ipsilateral] vs. 2.35 ± 0.34 [contralateral]). No significant differences in hippocampal volume were found between different groups (left hippocampus, P = 0.87; right hippocampus, P = 0.87). GluCEST imaging have potential for the noninvasive measurement of glutamate levels in the brains of children with epilepsy. 2 TECHNICAL EFFICACY: Stage 1.

Rate of abnormalities in quantitative MR neuroimaging of persons with chronic traumatic brain injury

BackgroundMild traumatic brain injury (mTBI) can result in lasting brain damage that is often too subtle to detect by qualitative visual inspection on conventional MR imaging. Although a number of FDA-cleared MR neuroimaging tools have demonstrated changes associated with mTBI, they are still under-utilized in clinical practice.MethodsWe investigated a group of 65 individuals with predominantly mTBI (60 mTBI, 48 due to motor-vehicle collision, mean age 47 ± 13 years, 27 men and 38 women) with MR neuroimaging performed in a median of 37 months post-injury. We evaluated abnormalities in brain volumetry including analysis of left-right asymmetry by quantitative volumetric analysis, cerebral perfusion by pseudo-continuous arterial spin labeling (PCASL), white matter microstructure by diffusion tensor imaging (DTI), and neurometabolites via magnetic resonance spectroscopy (MRS).ResultsAll participants demonstrated atrophy in at least one lobar structure or increased lateral ventricular volume. The globus pallidi and cerebellar grey matter were most likely to demonstrate atrophy and asymmetry. Perfusion imaging revealed significant reductions of cerebral blood flow in both occipital and right frontoparietal regions. Diffusion abnormalities were relatively less common though a subset analysis of participants with higher resolution DTI demonstrated additional abnormalities. All participants showed abnormal levels on at least one brain metabolite, most commonly in choline and N-acetylaspartate.ConclusionWe demonstrate the presence of coup-contrecoup perfusion injury patterns, widespread atrophy, regional brain volume asymmetry, and metabolic aberrations as sensitive markers of chronic mTBI sequelae. Our findings expand the historic focus on quantitative imaging of mTBI with DTI by highlighting the complementary importance of volumetry, arterial spin labeling perfusion and magnetic resonance spectroscopy neurometabolite analyses in the evaluation of chronic mTBI.

Traction force ripple caused by electromagnetic parameter asymmetry analysis of A 12/13-pole linear flux-switching permanent magnet motor designed for urban rail transit

Traction force ripple caused by electromagnetic parameter asymmetry analysis of A 12/13-pole linear flux-switching permanent magnet motor designed for urban rail transit