Comparison of Myocardial Layer-Specific Strain and Global Myocardial Work Efficiency During Treadmill Exercise Stress in Detecting Significant Coronary Artery Disease

BackgroundMyocardial layer-specific strain can identify myocardial ischemia. Global myocardial work efficiency (GWE) based on non-invasive left ventricular (LV) pressure-strain loops is a novel parameter to determine LV function considering afterload. The study aimed to compare the diagnostic value of GWE and myocardial layer-specific strain during treadmill exercise stress testing to detect significant coronary artery disease (CAD) with normal baseline wall motion.MethodsEighty-nine patients who referred for coronary angiography due to suspected of CAD were included. Forty patients with severe coronary artery stenosis were diagnosed with significant CAD, and 49 were defined as non-significant CAD. Stress echocardiography was performed 24 h before angiography. Layer-specific longitudinal strains were assessed from the endocardium, mid-myocardium, and epicardium by 2D speckle-tracking echocardiography. Binary logistic regression analyses were performed to evaluate the association between significant CAD and echocardiographic parameters. A receiver operating characteristic curve was used to assess the capability of layer-specific strain and GWE to diagnose significant CAD.ResultsPatients with significant CAD had the worse function in all three myocardial layers at peak exercise compared with those with non-significant CAD when assessed with global longitudinal strain (GLS). At the peak exercise and recovery periods, GWE was lower in patients with significant CAD than in patients with non-significant CAD. In multivariable binary logistic regression analysis, peak endocardial GLS (OR: 1.35, p = 0.006) and peak GWE (OR: 0.76, p = 0.001) were associated with significant CAD. Receiver operating characteristic curves showed peak GWE to be superior to mid-myocardial, epicardial, and endocardial GLS in identifying significant CAD. Further, adding peak GWE to endocardial GLS could improve diagnostic capabilities.ConclusionsBoth GWE and endocardial GLS contribute to improving the diagnostic performance of exercise stress echocardiography. Furthermore, adding peak GWE to peak endocardial GLS provides incremental diagnostic value during a non-invasive screening of significant CAD before radioactive or invasive examinations.

Mechanical and Self-Healing Performances of Crumb Rubber Modified High-Strength Engineered Cementitious Composites

High-strength engineered cementitious composite (HS-ECC) reinforced with polyethylene (PE) fiber characterizes wider crack widths than the conventional polyvinyl alcohol fiber-reinforced ECC (PVA-ECC), weakening the self-healing potential of HS-ECC. The properties of HS-ECC are tailored by introducing crumb rubber (CR), as artificial flaws can lower the matrix toughness and the crack width, leading to an enhanced self-healing potential of HS-ECC. In this study, CR is used to entirely replace silica sand (SS) with three equivalent aggregate-to-binder ratios of 0.2, 0.4, and 0.6, and two CR particle sizes (i.e., CR1 and CR2) are also considered to investigate the effects on density, compressive properties, and tensile performances of HS-ECC. Although CR substitution of SS influences adversely the mechanical strengths of HS-ECC, it can reduce the HS-ECC matrix fracture toughness, activate more microcracks, and reduce the crack width. Moreover, CR-modified HS-ECC specimens featuring the smallest crack width were preloaded to three specific strain levels, including 0.5%, 1.0%, and 2.0%, and then experienced wet–dry conditioning to exhibit effective mechanical and non-mechanical property recovery. The further hydration of binder materials enhances the interfacial bond stress and thus retains the mechanical performances of self-healed HS-ECC, which is expected to improve the practical application and benefit the sustainability of HS-ECC.

A machine learning framework for the evaluation of myocardial rotation in patients with noncompaction cardiomyopathy

Aims Noncompaction cardiomyopathy (NCC) is considered a genetic cardiomyopathy with unknown pathophysiological mechanisms. We propose to evaluate echocardiographic predictors for rigid body rotation (RBR) in NCC using a machine learning (ML) based model. Methods and results Forty-nine outpatients with NCC diagnosis by echocardiography and magnetic resonance imaging (21 men, 42.8±14.8 years) were included. A comprehensive echocardiogram was performed. The layer-specific strain was analyzed from the apical two-, three, four-chamber views, short axis, and focused right ventricle views using 2D echocardiography (2DE) software. RBR was present in 44.9% of patients, and this group presented increased LV mass indexed (118±43.4 vs. 94.1±27.1g/m2, P = 0.034), LV end-diastolic and end-systolic volumes (P< 0.001), E/e’ (12.2±8.68 vs. 7.69±3.13, P = 0.034), and decreased LV ejection fraction (40.7±8.71 vs. 58.9±8.76%, P < 0.001) when compared to patients without RBR. Also, patients with RBR presented a significant decrease of global longitudinal, radial, and circumferential strain. When ML model based on a random forest algorithm and a neural network model was applied, it found that twist, NC/C, torsion, LV ejection fraction, and diastolic dysfunction are the strongest predictors to RBR with accuracy, sensitivity, specificity, area under the curve of 0.93, 0.99, 0.80, and 0.88, respectively. Conclusion In this study, a random forest algorithm was capable of selecting the best echocardiographic predictors to RBR pattern in NCC patients, which was consistent with worse systolic, diastolic, and myocardium deformation indices. Prospective studies are warranted to evaluate the role of this tool for NCC risk stratification.

Utility of 4-Dimensional echocardiography and left ventricular systolic strain measured by 2-dimensional speckle-tracking for Danon Disease- a case series

Background Danon disease is an X-linked multisystemic disorder characterised by skeletal myopathy, cardiomyopathy and intellectual disability. Summary of cases Herein we describe two patients affected by Danon disease from the same family, a father (patient 1) and his daughter (patient 2). In patient 1 a short PR interval with pre-excitation was evident. In patient 2, over a 24-hour period 2369 atrial premature beats and rare isolated ventricular ectopics were detected. Both patients exhibited left ventricular hypertrophy with non-compaction myocardium, and the left ventricular ejection fraction was impaired in patient 1 and normal in patient 2. In patient 2, the total left ventricular strain value was reduced, and layer-specific strain revealed that subepicardial strain impaired more than in other layers. Late gadolinium enhancement was detected both in left and right ventricles in patient 2, and cardiac fibrosis was more apparent in the subepicardium of left ventricular free wall. Four-dimensional echocardiography revealed that left atrial reservoir strain and left ventricular total longitudinal strain were induced. Discussion Novel four-dimensional echocardiography and left ventricular systolic strain may play important role in diagnosis and myocardial functional evaluation in Danon disease.

Visual detection of microbial community during three bacteria mixed fermentation through hyperspectral imaging technology

Hyperspectral imaging technology with chemometrics was used for identifying and counting each species in microbial community during mixed fermentation. Hyperspectral images of microbial community of <i>Enterobacter</i> sp, <i>Acetobacter pasteurianus</i>, and <i>Lactobacillus paracasei</i> colonies were obtained and the spectra of strain colonies were extracted. Identification models were developed using linear discriminant analysis (LDA) and least-squares support vector machine (LS-SVM) by using 23 variables selected by genetic algorithm. The optimal LS-SVM model with identification rate of 96.67 % was used to identify colonies and prepare colony distribution maps in color for strains counting. The counting results by hyperspectral imaging technology agree with that of the manual counting method with average relative error of 3.70 %. The developed counting method has been successfully used to identify and count the specific strain from the mixed strains simultaneously. The hyperspectral imaging technology has a great potential to monitor changes in the microbial community structure.

Explaining Latinx Youth Delinquency: A Gendered Test of Latinx General Strain Theory

Recently, scholars have reintroduced a Latinx general strain theory in which it is suggested that ethnic-specific strains, including acculturation, are driving forces for criminal and delinquent behaviors among the Latinx population. Using data collected from the Dating Violence Among Latino Adolescents (DAVILA) Study, this study investigated whether these ethnic strains influenced delinquency differently based on the respondent's gender. Results indicate that boys engaged in more delinquent behaviors than girls, whereas girls were more acculturated than boys. Depression, anxiety, and social support were more prevalent among girls than among boys. In addition, girls were more likely to be enculturated and perform better in school than boys. Acculturation did not significantly predict delinquency for either boys or girls. In contrast, polyvictimization was the only variable to consistently predict delinquency among boys and girls. Results provided partial support for the hypotheses, in that, while depression and anxiety varied by gender as predicted by the gendered general strain theory, the ethnic-specific strain of acculturation failed to predict delinquent behavior in this sample. Ultimately, this study highlights the need to examine other ethnic-specific strains to better understand delinquent behavior among Latinx youth.

Effectiveness of using the dose of mycorrhiza bio-fertilizers to increase growth and production of red paprika (Capsicum annum L.) in Ultisol Aceh

Using dose mycorrhizal bio-fertilizers can spur the growth and production of red paprika (Capsicum annum L.) on Ultisol Aceh. Besides that, it can also increase root colonization by mycorrhizal and P2O5 uptake, which red paprika plants need to produce high growth and yield. The purpose of this research was to study the effect of dose bio-fertilizer mycorrhizal on the growth and production of red paprika in Ultisols Aceh. The research was arranged by a non-factorial randomized block design with three replications. The investigated factor was the dose of bio-fertilizer mycorrhizal from local specific strain mixing between Glomus mosseae and Gigaspora sp. The dose of the mycorrhizal bio-fertilizer used was control (without mycorrhizal) of each plant, 5, 10, and 15 gram. The observed parameters were plant height and stem diameter of red paprika at 15, 30, and 45 days after transplanting; additionally, the parameter of red paprika production was observed at 125 days after transplanting and P2O5 uptake and root colonization by mycorrhizae at 60 days after transplanting. The results showed that the best dose of mycorrhizal bio-fertilizers on growth and production, root colonization, P2O5 uptake was found in the treatment of doses of 10-gram mycorrhizal bio-fertilizer for each plant.

Prognostic value of layer-specific global longitudinal strain in patients undergoing coronary artery bypass grafting

Background Recent improvements in speckle tracking echocardiography have made sectionalized quantification of layer-specific global longitudinal strain (GLS) possible. Prior studies have reported prognostic value of GLS in several cardiac diseases, however, the use of layer-specific strain has not been investigated in patients undergoing coronary artery bypass grafting (CABG). Purpose To determine the prognostic value of layer-specific GLS for predicting all-cause mortality after CABG. Methods In this retrospective cohort study, consecutive patients undergoing isolated CABG between 2006 and 2011 were included. The patients were followed through nation-wide registries for the endpoint of all-cause mortality. Multivariable Cox regression models adjusted for clinical and echocardiographic baseline characteristics were used to assess the association between layer-specific GLS and all-cause mortality. Cumulative survival was stratified by clinical age and gender-dependent cut-off values for the layer-specific GLS, which was obtained from a large healthy population study. Results Of 641 patients included (mean age 67 years, 84% male), 70 (10.9%) died during follow-up (median 3.8 years [IQR: 2.7; 4.9 years]). Patients who died during follow-up were significantly older (71 years vs. 67 years, P = &lt;0.001) and had a lower LVEF (46% vs. 51% P = &lt;0.001). Endocardial GLS (GLSendo) (−14.2% vs. −16.3%, P&lt;0.001), whole wall GLS (−12.1% vs. −13.9%, P&lt;0.001), and epicardial GLS (GLSepi) (−10.6% vs. −12.2%, P&lt;0.001) were all reduced in patients who died during follow-up, and patients with GLS below cut-off had a more than two-fold increased risk of all-cause mortality (Figure 1). The risk of dying increased linearly with decreasing absolute GLS for all layers (p&lt;0.0002 for all layers), (Figure 2). In multivariable models, all layer-specific strain parameters remained significantly associated with all-cause mortality; GLSepi: HR=1.14 (1.05–1.23), p=0.002; GLS: HR=1.12 (1.04–1.20), p=0.002; GLSendo: HR=1.09 (1.03–1.16), p=0.003, per 1% absolute decrease. However, only GLSepi remained significantly associated with mortality when also adjusting for echocardiographic parameters (GLSepi: HR=1.12 (1.00–1.25), p=0.049, per 1% absolute decrease) and separately also after adjusting for the EuroScore II (GLSepi: HR=1.09 (1.00–1.18), p=0.043, per 1% absolute decrease). Conclusion Layer-specific GLS is an independent prognosticator of all-cause mortality after CABG. In multivariable models, GLSepi provided significant prognostic value after adjusting for echocardiographic parameters and EuroScore II. FUNDunding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Research grant from Herlev & Gentofte University Hospital's internal research funds. Figure 1. Kaplan-Meier survival estimates Figure 2. Incidence rate of all-cause mortality

Metagenomic survey of agricultural water using long read sequencing: considerations for a successful analysis

Background Leafy greens are responsible for nearly half of the produce-related Shiga toxin-producing Escherichia coli (STEC) outbreaks in the United States and recent investigations have implicated agricultural water as a potential source. Current FDA detection protocols require extensive analysis time. Development of methods for rapid detection of STECs in the field are imperative to maintain food safety. We aimed to use Oxford Nanopore rapid sequencing kits for an in-field determination of agricultural water microbiome and possible detection and characterization of STECs strain(s) in these samples. Results We tested the performance of the nanopore rapid sequencing kit (RAD004) for fast microbiome determination using the well characterized ZymoBIOMICS mock microbial community and the number of reads for each identified species was present in the expected proportion. Rapid sequencing kit (LRK001 and RAD004) library preparation of DNA extracted from agricultural water resulted in poor nanopore sequencing reactions, with low output (0.3–1.7 M reads), a high proportion of failed reads (50–60%), and highly sheared DNA before and after a magnetic bead clean up. To improve performance, we prepared a DNA library with the ligation kit (LSK109), which includes multiple cleaning steps, reducing inherent inhibitors and producing a better outcome (2.2 M reads, 15% failed reads). Metagenomic composition of four sample sites determined using the ligation kit, showed a highly diverse bacterial community for each site, with 11 total genera identified, including Synechococcus and Cyanobium. No definitive presence of STEC could be confirmed in any of the sites. Approximately 100 reads from each site (0.02% of total reads) were identified as Escherichia coli, but the specific strain or their virulence genes could not be detected. Sites 9, 10, and 12 were found to be positive for STEC presence by microbiological techniques after enrichment. Conclusions The rapid sequencing kits can be appropriate for genus or species level microbial identification, but we recommend the use of the ligation kit for increased sequencing depth and removal of contaminants in agricultural water. However, we were not able to identify any STEC strains in these nanopore microbiome samples, due to low initial concentrations. The results from this pilot study provide preliminary evidence that MinION sequencing of agricultural water using the ligation kit has the potential to be used for rapid microbiome determination in the field with optimal results for water quality surveillance.

Dectin-2 mediates phagocytosis of Lactobacillus paracasei KW3110 and IL-10 production by macrophages

Lactic acid bacteria (LAB) are most generally used as probiotics and some strains of LAB are known to have anti-inflammatory effects. A specific strain of lactic acid bacteria, Lactobacillus paracasei KW3110 (KW3110), activates macrophages to produce interleukin-10 (IL-10), an anti-inflammatory cytokine; however, the biological mechanism remains unclear. In this study, we showed that the amount of incorporated KW3110 into a macrophage cell line, RAW 264.7, was higher than other genetically related strains using fluorescence microscopy. RNA-seq analysis indicated that treatment of macrophages with KW3110 induced Dectin-2 gene expression, which is a pattern recognition receptor, recognizing α-mannose. In addition, antibody treatment and knock down of Dectin-2, or factors downstream in the signaling pathway, decreased the amount of incorporated KW3110 and IL-10 production. Substantial lectin array analysis also revealed that KW3110 had higher binding affinities to lectins, which recognize the carbohydrate chains comprised of α-mannose, than two other LAB. In conclusion, KW3110 is readily incorporated into macrophages, leading to IL-10 production. Dectin-2 mediated the phagocytosis of KW3110 into macrophages and this may be involved with the characteristic carbohydrate chains of KW3110.