Cost prediction for ischemic heart disease hospitalization: Interpretable feature extraction using network analysis.

OBJECTIVES: Ischemic heart disease (IHD) is a significant contributor to global mortality and disability, imposing a substantial social and economic burden on individuals and healthcare systems. To enhance the efficient allocation of medical resources and ultimately benefit a larger population, accurate prediction of healthcare costs is crucial. METHODS: We developed an interpretable IHD hospitalization cost prediction model that integrates network analysis with machine learning. Specifically, our network-enhanced model extracts explainable features by leveraging a diagnosis-procedure concurrence network and advanced graph kernel techniques, facilitating the capture of intricate relationships between medical codes. RESULTS: The proposed model achieved an R2 of 0.804 ± 0.008 and a root mean square error (RMSE) of 17,076 ± 420 CNY on the temporal validation dataset, demonstrating comparable performance to the model employing less interpretable code embedding features (R2: 0.800 ± 0.008; RMSE: 17,279 ± 437 CNY) and the hybrid graph isomorphism network (R2: 0.802 ± 0.007; RMSE: 17,249 ± 387 CNY). The interpretation of the network-enhanced model assisted in pinpointing specific diagnoses and procedures associated with higher hospitalization costs, including acute kidney injury, permanent atrial fibrillation, intra-aortic balloon bump, and temporary pacemaker placement, among others. CONCLUSION: Our analysis results demonstrate that the proposed model strikes a balance between predictive accuracy and interpretability. It aids in identifying specific diagnoses and procedures associated with higher hospitalization costs, underscoring its potential to support intelligent management of IHD.

H2/D2 Separation Using UTSA-16@CAU-10-H@γ-AlOOH Composites as the Stationary Phase in Gas Chromatography via the Additive Effects of Kinetic Sieving and Chemical Affinity Quantum Sieving.

In this work, CAU-10-H@γ-AlOOH is prepared, and then UTSA-16 is loaded on CAU-10-H@γ-AlOOH to obtain UTSA-16@CAU-10-H@γ-AlOOH. Using the as-prepared composites as stationary materials by cryogenic gas chromatography at 77 K, while CAU-10-H@γ-AlOOH achieves the complete separation of ortho-H2 (o-H2) and D2 with a resolution R of 1.66 and a separation time t of 9.52 min, UTSA-16@CAU-10-H@γ-AlOOH achieves higher efficiency separation of hydrogen isotopes in a shorter separation time (4.56 min) with R = 1.7. Molecular simulation results show that CAU-10-H has both chemical affinity quantum sieving and kinetic sieving effects for H2/D2 at 77 K, and UTSA-16 can only exert the kinetic sieving effect. UTSA-16's load on CAU-10-H@γ-AlOOH weakens the adsorption of hydrogen isotopes, and the presence of Co2+ in UTSA-16 promotes the conversion of para-H2 to ortho-H2. In gas chromatography, H2 was preferentially desorbed from the system due to strong D2 adsorption caused by the chemical affinity quantum sieving effect and faster H2 diffusion caused by the kinetic sieving effect. These additive effects achieved efficient hydrogen isotope separation at 77 K.

Intermediate occupation numbers for 5f electrons in a Pu and U mixed oxide.

In order to reveal the correlation effect on the electronic properties in particular 5f electron occupation numbers of Pu/U ions in a (Pu,U) mixed oxide-PuUO4, a first principles calculation is performed by using density functional theory (DFT) plus a dynamical mean field theory (DMFT) scheme with the spin-orbit coupling (SOC) and on-site Coulomb repulsion for correlation effect due to localized Pu/U 5f orbitals. Results demonstrate that Pu/U 5f electron occupation numbers in the ground state of PuUO4 are mainly composed of 5f4/5f5 and 5f2/5f3 configurations, and exhibiting the intermediate occupation (IO) numbers with average 5f occupation numbers of about nf = 4.879 and 2.423 for Pu and U ions, respectively, irrespective of different Pu and U lattice sites in PuUO4. Pu 5f j = 5/2 and j = 7/2 components are in moderately and weakly correlated states, respectively, while U 5f j = 5/2 and j = 7/2 manifolds are both in weakly correlated states. jj and LS coupling schemes are feasible for Pu and U 5f electrons, respectively. In order to directly compare with the experimental angle-resolved photoemission spectrum (ARPES), we also estimate the momentum-resolved electronic spectrum function for this system.

The association between ECG criteria and Echo criteria for left ventricular hypertrophy in a general Chinese population.

BACKGROUND: Several ECG criteria have been widely used for diagnosis of left ventricular hypertrophy (LVH) in clinical practice. However, their performance in a general Chinese population is limited. METHODS AND RESULTS: A multi-stage, stratified cluster sampling across China was performed and 7415 representative Chinese adults aged 18-85 years were analyzed. ECG was collected by using GE MAC 5500 machine. The association between five ECG-LVH criteria (i.e., Peguero-Lo Presti, Cornell, Cornell product, Sokolow-Lyon and Sokolow-Lyon product) and echocardiographic LVH (Echo-LVH) was assessed by Pearson's correlation, diagnostic statistics like predictive values, and receiver operating characteristics (ROC) curve. We found that the prevalence of the Echo-LVH was 11% while ECG-LVH ranged from 3% to 27%. All ECG-LVH criteria had high negative predictive value (NPV) (89%) and specificity (73-96%) but low positive predictive value (PPV) (12-24%) and sensitivity (4-29%). The newly Peguero-Lo Presti criteria had higher sensitivity (29%) but lower specificity (73%) and accuracy (68%) compared with other criteria. Cornell product had the best diagnostic performance (AUC: 0.59), as well as the highest specificity (96%) and accuracy (86%) but lowest sensitivity (4%). Among single-lead components of ECG criteria, RaVL voltage and QRS duration performed relatively better than others. Hypertensive and older individuals had higher sensitivity but lower specificity and accuracy than their counterparts. CONCLUSION: ECG-LVH criteria had high NPV to detect Echo-LVH. Though with higher sensitivity, Peguero-Lo Presti criteria did not have better diagnostic performance to detect Echo-LVH. RaVL and QRS duration had stronger association with Echo-LVH among all single-lead components.

Risk assessment in interstitial lung disease: the incremental prognostic value of cardiopulmonary ultrasound.

BACKGROUND: The mortality risk of chronic interstitial lung disease (ILD) is currently assessed using the ILD-GAP score. The present study evaluates whether the addition of cardiopulmonary ultrasound parameters to the ILD-GAP score can further improve the predictive value of ILD-GAP. METHODS: Medical records from 91 patients with ILD hospitalized from June 2015 to March 2016 were retrospectively examined. The Lung ultrasound (LUS) score, right ventricular (RV) function, and mechanics were obtained from the cardiopulmonary ultrasound. The ILD-GAP score was calculated from demographic characteristics and pulmonary function parameters. Patients were followed up with until May 2020. The primary endpoint was all-cause death. RESULTS: After exclusions, 74 patients with ILD were included in the analysis. During the follow-up period, 36 patients with ILD survived (ILDs), and 38 patients died (ILDd). Compared to ILDs, the ILDd cases exhibited a higher number of B-lines, LUS score, and RV end-diastolic base dimension (RVD), but lower RV function. In multivariate analysis, the ILD-GAP score (hazard ratio, 2.88; 95% CI 1.38-5.99, P = 0.005), LUS score (hazard ratio 1.13; 95% CI 1.04-1.24, P = 0.006), and RVD (hazard ratio 1.09, 95% CI 1.03-1.16, P = 0.004) were significantly related to the risk of death. Adding the LUS score and RVD to the ILD-GAP score significantly improved the predictive value compared to the ILD-GAP score alone (C statistics 0.90 vs 0.76, P = 0.018). CONCLUSION: We investigated the utility of a new prognostic model for ILD that includes both cardiopulmonary ultrasound parameters (LUS score and RVD) and the ILD-GAP score. This model better reflects the severity of pulmonary fibrosis and cardiac involvement, and has incremental predictive value over the ILD-GAP score alone.

Mexiletine Shortened QT Interval and Reduced Ventricular Arrhythmias in a Pedigree of Type 2 Long QT Syndrome Combined with Left Ventricular Non-Compaction.

In this study, we present a case of a 22-year-old female with a family history of syncope, suffering from recurrent syncope since childhood. She had an obvious prolonged QTc interval of up to 651 ms, a bifid T wave pattern on electrocardiogram, and torsade de pointes, corresponding to a syncope episode. Additionally, her echocardiogram showed left ventricular non-compaction in the apex. After treatment with mexiletine, the QTc interval has been observed to shorten immediately, and the T wave morphology recovered. A similar effect was also observed in her mother and young sister. Administration of propranolol prolonged her QTc interval. Target sequencing of candidate genes revealed a missense mutation in the pore area of the hERG protein, coded by KCNH2. We diagnosed this as a case of type 2 long QT syndrome in which mexiletine could be effective in shortening the QTc interval.

Left ventricular end-diastolic strain rate recovered in hypothyroidism following levothyroxine replacement therapy: A strain rate imaging study.

BACKGROUND: This study aimed to explore the impact of overt hypothyroidism on diastolic left ventricular (LV) deformation and the effect of levothyroxine therapy using 2-dimensional speckle-tracking echocardiography (STE) strain rate (SR) imaging. METHODS: Forty-seven newly diagnosed hypothyroidic patients and 51 controls were prospectively enrolled. All participants underwent comprehensive 2-dimensional echocardiography. Besides the recently recommended parameters of LV diastolic function, strain imaging for LV systolic global longitudinal strain (GLS), and diastolic SR imaging at isovolumic relaxation period (SRivr), early (SRe) and late (SRa) diastole were assessed. Repeated echocardiography in hypothyroidic patients was made 6 months after the euthyroidic state was achieved. RESULTS: Hypothyroidic patients had a lower ejection fraction (EF) than the controls (68.6 ± 5.2% vs 71.5 ± 4.0%, P = 0.002) but all within normal range (57%-80% and 64%-79%, respectively). No difference in the ratio of early mitral flow (E) to early diastolic septal or lateral myocardial motion velocity (e') was found (both P > 0.05), but significant difference was identified for SRa (0.85 ± 0.17 [/s] vs 1.00 ± 0.17 [/s], P = 0.000) and GLS (-20.8 ± 3.2% vs -23.6 ± 2.3%, P = 0.000). Upon follow-up, LV SRa (1.01 ± 0.20 [/s], P = 0.99 vs control) normalized when GLS (-21.6 ± 3.1%, P = 0.004 vs control) remained worse than the controls. CONCLUSION: This study demonstrates subtle LV diastolic impairment in untreated hypothyroidic patients using SR imaging, which normalizes with short-term therapy and predates GLS.

Echocardiographic characteristics of primary malignant pericardial mesothelioma and outcomes analysis: a retrospective study.

BACKGROUND: Little is known about the echocardiographic characteristics of primary malignant pericardial mesothelioma (PPM) due to its rarity. The aim of this study was to explore the sex-specific echocardiographic patterns of PPM and risk factors for in-hospital mortality. METHODS: A retrospective information retrieval was conducted for cases of PPM reported from China during 1981 and 2015. The diagnosis was made by histopathological examinations and only cases with echocardiographic descriptions were included. Data on the clinical and echocardiographic findings were collected. Difference in clinical, sex-specific echocardiographic characteristics and findings across different time periods were assessed. Logistic regression analysis was performed to explore echocardiographic risk factors for in-hospital mortality. RESULTS: A total of 64 patients with PPM were included, with a mean age of 39.2 ± 15.6 years and minor male dominance (40, 62.5%). The most common echocardiographic presentations were pericardial effusion (55, 85.9%), pericardial masses (36.4%) and thickening (17.3%), respectively. The positive rate of pericardiocentesis was only 20.9%. Six patients (15.4%) died among 39 cases reporting in-hospital outcome. Logistics analysis identified no clinical or echocardiographic parameters associated with in-hospital mortality (all P > 0.05). CONCLUSIONS: The echocardiographic signs of PPM are basically nonspecific with massive pericardial effusion as the most common sign, although no echocardiographic gender differences or association with in-hospital mortality could be identified.

High-Resolution Transthoracic Ultrasonography for Assessment of Pleural Lines in Patients With Dyspnea With CT Comparison: An Observational Study.

OBJECTIVES: Detection of B-line in dyspneic patients is often accompanied by abnormal changes of pleural line on transthoracic ultrasonography (TUS). The aim of the study was to evaluate the relevance and diagnostic performance of pleural line abnormalities and B-lines detected on high-resolution TUS against the computed tomography (CT) findings. METHODS: Transthoracic ultrasonography was performed in patients admitted to the emergency department with dyspnea. The pleural line and accompanying B-line were assessed using a linear transducer. The TUS findings were assessed against the corresponding high-resolution CT findings in the same location, which were considered to be the gold standard. RESULTS: Out of a total of 116 patients, 68.1% had changes of the pleural line on TUS. The characteristic changes of the pleural line were classified into four types: slightly rough pleural line with confluent B-lines on TUS corresponded with CT findings of ground-glass opacity; irregular and interrupted pleural line with confluent B-lines corresponded with parenchymal infiltration; fringed pleural line with confluent B-lines corresponded with superimposed ground-glass and irregular reticular opacities; and fringed pleural line with scattered B-lines corresponded with irregularly thickened interlobular septa. Wavy pleural line indicated subpleural emphysema. The coexistence of more than one abnormal pleural line was also found in 31 cases (26.7%). CONCLUSIONS: High-resolution TUS may help in the initial assessment of lung pathology by its ability to identify pleural line abnormalities and B-lines that are shown to be associated with CT, which could add diagnostic value in the emergency evaluation of dyspneic patients.

Isolated Congenital Muscular Diverticulum of the Left Ventricular Apex Complicated with Mural Thrombosis in an Adult.

We present a case of apical isolated congenital left ventricular (LV) diverticulum complicated with mural thrombosis in an adult and elucidate the echocardiographic features for differential diagnosis of LV outpouchings.

Case report: Primary pericardial angiosarcoma, a rare cause of cardiac tamponade.

Primary pericardial angiosarcoma is a rare malignancy of the pericardium with variable clinical features and imaging characteristics. Herein, we report a case of histopathologically confirmed pericardial angiosarcoma in a 66-year-old man. The patient developed cardiac tamponade in a short time period. The transthoracic echocardiography showed the presence of multiple irregular echodensities, heterogeneous in echogenicity, encasing the apex of both ventricles in the pericardial space, initially misinterpreted as pericardial effusion. The patient died of cardiogenic shock despite undergoing a surgical pericardiectomy. Pericardial angiosarcoma can manifest as a mass obliterating the pericardial sac, rather than the typical pericardial effusion observed on echocardiography. Multimodality imaging studies aid in diagnosing primary pericardial angiosarcoma, but the final diagnosis relies on tissue histopathology.

Construction and expression of Mycobacterium tuberculosis fusion protein SHR3 and its immunogenicity analysis in combination with various adjuvants.

Tuberculosis (TB) today remains the leading cause of global deaths due to infectious bacterial pathogens. The Bacillus Calmette-Guérin (BCG) vaccine is the only vaccine clinically used to prevent TB. However, its limitations in preventing latent infection and TB reactivation mean that it does not provide comprehensive protection. In this study, we successfully constructed and expressed the multistage fusion protein, SHR3, and used whole blood IFN-γ release assay (WBIA) with flow cytometry to detect antigen specificity, further confirmed by enzyme-linked immunosorbent assay (ELISA). SHR3 and its subfractional proteins stimulated the level of IFN-γ production by lymphocytes from M. tb-infected patients, inducing the production of single-positive and double-positive CD4+ and CD8+ T cells with IFN-γ and IL-2, at levels significantly higher than those of healthy controls. The fusion protein and complex adjuvant group (SHR3/DMT) induced mice to produce significantly higher levels of IgG antibodies and their subclasses, with IgG2a/IgG1 results showing a convergent Th1-type response; mice in the BCG + SHR3/DMT group induced secretion of the highest levels of IL-2, and TNF-α, irrespective of stimulation with purified protein derivative or SHR3. These findings suggest that SHR3/DMT could be a potential subunit vaccine candidate that may serve as an effective booster vaccine after BCG primary immunization.

Unraveling pancreatic ductal adenocarcinoma immune prognostic signature through a naive B cell gene set.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC), a leading cause of cancer mortality, has a complex pathogenesis involving various immune cells, including B cells and their subpopulations. Despite emerging research on the role of these cells within the tumor microenvironment (TME), the detailed molecular interactions with tumor-infiltrating immune cells (TIICs) are not fully understood. METHODS: We applied CIBERSORT to quantify TIICs and naive B cells, which are prognostic for PDAC. Marker genes from scRNA-seq and modular genes from weighted gene co-expression network analysis (WGCNA) were integrated to identify naive B cell-related genes. A prognostic signature was constructed utilizing ten machine-learning algorithms, with validation in external cohorts. We further assessed the immune cell diversity, ESTIMATE scores, and immune checkpoint genes (ICGs) between patient groups stratified by risk to clarify the immune landscape in PDAC. RESULTS: Our analysis identified 994 naive B cell-related genes across single-cell and bulk transcriptomes, with 247 linked to overall survival. We developed a 12-gene prognostic signature using Lasso and plsRcox algorithms, which was confirmed by 10-fold cross-validation and showed robust predictive power in training and real-world cohorts. Notably, we observed substantial differences in immune infiltration between patients with high and low risk. CONCLUSION: Our study presents a robust prognostic signature that effectively maps the complex immune interactions in PDAC, emphasizing the critical function of naive B cells and suggesting new avenues for immunotherapeutic interventions. This signature has potential clinical applications in personalizing PDAC treatment, enhancing the understanding of immune dynamics, and guiding immunotherapy strategies.

Rapid diffusion of H2 and strong adsorption of D2 in Ni-4PyC realized the efficient separation of H2/D2 by gas chromatography.

In this work, Ni-4PyC was selected as the material for the separation of hydrogen isotopes H2/D2, and the mechanism of hydrogen isotope H2/D2 separation was investigated by molecular simulation. The results showed that the adsorption selectivity of Ni-4PyC for D2/H2 increased from 1.26 to 1.46 when the temperature was decreased from 77 K to 20 K, indicating that Ni-4PyC effected chemical affinity quantum sieving on D2/H2. Also, the diffusion rates of H2/D2 were different at different temperatures. At 20 K, the kinetic selectivity of D2/H2 reached 1.30, indicating that Ni-4PyC had a kinetic quantum sieving effect on D2/H2 at low temperatures. However, when the temperature was higher than 30 K, the diffusion rate of H2 was faster than that of D2, and when the temperature was 77 K, Ni-4PyC exhibited the kinetic sieving effect with a kinetic selectivity of 1.59 for H2/D2. Due to the chemical affinity quantum sieving and kinetic sieving effects of Ni-4PyC on H2/D2, the adsorption capacity of Ni-4PyC for D2 was better than that for H2 and the diffusion rate of H2 was faster than that of D2 at 77 K. Therefore, Ni-4PyC was expected to achieve the separation of H2/D2. In order to verify the accuracy of the theoretical calculation results, an Ni-4PyC@γ-Al2O3 composite material was synthesized by a liquid phase epitaxy method and was used to separate H2/D2 at 77 K in a 0.6 m × 2 mm chromatographic column. Under optimal separation conditions, the resolution R reached 1.84 with a separation time t = 7.47 min. In addition, Ni-4PyC@γ-Al2O3 showed excellent separation performances for different ratios of H2/D2 mixtures. The stationary phase was repeatable and reproducible.

H2/D2 separation in gas chromatography through a MOF-on-MOF strategy using γ-AlOOH@Al(OH)(1,4-NDC)@ZIF-67 as the stationary phase via additive effects of chemical affinity quantum sieving and kinetic sieving.

The reaction of porous γ-Al2O3 particles acting as both a sacrificial template and an aluminum source with 1,4-naphthalene diacid (H2NDC) resulted in the formation of γ-AlOOH@Al(OH)(1,4-NDC) composites, in which ZIF-67 was then loaded by the in situ crystallization method, leading to the formation of γ-AlOOH@Al(OH)(1,4-NDC)@ZIF-67 composites. The deliberately designed composite was used to separate H2/D2 at 77 K in a 1 m chromatographic column. The results demonstrated that the optimized composite can achieve the effective separation of H2/D2 in gas chromatography due to the additive effects of kinetic sieving and chemical affinity quantum sieving of Al(OH)(1,4-NDC) and ZIF-67. By optimizing chromatographic separation conditions, the resolution R reached 2.02 with the separation time t = 7.72 min. The composite also showed satisfactory repeatability and reproducibility.

A Comprehensive Review of the Current Research Status of Biodegradable Zinc Alloys and Composites for Biomedical Applications.

Zinc (Zn)-based biodegradable materials show moderate degradation rates in comparison with other biodegradable materials (Fe and Mg). Biocompatibility and non-toxicity also make them a viable option for implant applications. Furthermore, Pure Zn has poor mechanical behavior, with a tensile strength of around 100-150 MPa and an elongation of 0.3-2%, which is far from reaching the strength required as an orthopedic implant material (tensile strength is more than 300 MPa, elongation more than 15%). Alloy and composite fabrication have proven to be excellent ways to improve the mechanical performance of Zn. Therefore, their alloys and composites have emerged as an innovative category of biodegradable materials. This paper summarizes the most important recent research results on the mechanical and biological characteristics of biodegradable Zn-based implants for orthopedic applications and the most commonly added components in Zn alloys and composites.

Implementing case-based collaborative learning curriculum via webinar in internal medicine residency training: A single-center experience.

This study aimed to investigate the effects of the Case-based collaborative learning (CBCL) curriculum in webinar format on internal medicine residents' knowledge covering cardiologic topics and their attitudes toward the CBCL teaching module. CBCL is a novel small-group approach, that incorporates elements of problem-based learning and case-based learning, and it has shown to improve medical students' knowledge mastery. However, few studies have explored its applicability for internal medicine residents, especially in the webinar format. This prospective cohort study included internal medicine residents in a residency program in Beijing, China. Eight CBCL sessions in webinar format covering cardiologic topics were delivered to them from February to April 2020. Pre-session reading materials included textbook and guidelines published by the academic societies. Multiple-choice questions were delivered to assess participants' knowledge before and after the sessions. Changes in participants' knowledge were determined using the paired t test to compare mean values. In addition, surveys based on 5-point Likert scale scores assessed satisfaction at the end of the second and eighth sessions. The Wilcoxon signed-rank test was used to identify any potential satisfaction improvement. In total, 9 internal medicine residents participated in the study, of whom 33.3% were male, and the overall rate of participation in CBCL sessions in webinar format was 94.4%. The mean scores of 50 multiple-choice questions were 68.0 ± 12.3 and 75.1 ± 9.9 in the pre- and post-curriculum assessments (P = .029). In the first survey performed at the second week, 5 (55.6%) residents chose "like" or "extremely like" in overall satisfaction, "neutral" by 3 (33.3%) residents and "dislike" by 1 (11.1%) resident. In the second survey, only 1 (11.1%) resident selected a neutral reply in satisfactory assessment, and the other 8 (88.9%) residents selected either "like" or "extremely like" choices. Compared with the results of the first survey, the overall satisfaction rate significantly improved (P = .031). Implementing the CBCL sessions in webinar format for cardiology residents was resulted in the improved knowledge mastery and a high acceptance rate.

Thinking and Research on Ideology Education of University Student Based on Deep Learning in Small Sample Environment.

Building an evaluation system for new media ideology education in colleges and other higher education institutions is helpful for assessing the current ideology education and encouraging high levels of information technology integration in ideology education has emerged as a key strategy for this type of education. Based on the central tenet of deep learning theory, ideology education for university students can explore educational strategies from six perspectives in order to achieve deep learning for universities. These six perspectives are opening educational channels, integrating educational contents, assisting knowledge construction, creating educational situations, problem-solving, and developing multiple evaluations. This study proposes a deep learning-based evaluation model for ideology teaching through new media in higher education institutions and colleges, applies deep learning theory to the study's research samples, and calculates the degree of association. Test samples are used to evaluate the network, and positive test outcomes are attained. The deep learning model can effectively increase the accuracy of choosing an ideological and political education approach, as evidenced by its average ideal accuracy of 92.6 percent, which is higher than that of PS-BP and DE-BP, which are 86.4 percent and 82.2 percent, respectively.

Longitudinal change, gender difference and hemodynamic implications of aortoseptal angle in adults without structural heart diseases.

This is an era of function evaluation for heart, but still there are some structural changes remains to be recognized. Aorto-septal angle (AoSA) is a morphologic description of the heart and adjacent major vessel. Previous studies have shown its potential hemodynamic significance, however, these are conducted in patients with structural heart diseases. The present study investigated its longitudinal change in 140 adults without structural heart disease from 20 to 90 years old and its independent clinical correlates. The findings included: 1. Advanced age, male and presence of sigmoid IVS were independent predictors of a steep AoSA. 2. Females tend to have a wider AoSA compared to age-matched males before 70 years old but they undergo more dramatic decrease with aging so that no gender difference was found beyond 70 years old. 3. Electrocardiographic QRS axis left deviation tends to be correlated with a steeper AoSA. 4. In adults without structural heart disease, no clinically significant association between AoSA and aortic velocity was found. Further prospective study from multi-centers is needed to verify these findings.

Anti-Skid Characteristics of Asphalt Pavement Based on Partial Tire Aquaplane Conditions.

This study presented a finite element model of radial tire-asphalt pavement interaction using ABAQUS 6.14 software to investigate the skid resistance properties of asphalt pavement under partial tire aquaplane conditions. Firstly, the pavement profile datum acquired by laser scanning were imported to Finite Element Analysis (FEA) software to conduct the pavement modeling. Secondly, a steady state rolling analysis of a tire on three types of asphalt pavements under drying conditions was carried out. Variation laws of the friction coefficient of the radial tire on different pavements with different pavement textures, tire pressures, and loads on the tire were examined. Subsequently, calculation results of the steady state rolling analysis were transmitted to dynamic explicit analysis, and an aquaplane model of a radial tire on asphalt pavements was built by inputting the flow Euler grids. The tire-pavement adhesive characteristics under partial aquaplane conditions are discussed regarding the aquaplane model. Influences of the thickness of water film, the texture of asphalt pavement, and the rolling speed of the tire on the vertical pavement-tire contact force are analyzed. It is found that the vertical contact force between open graded friction course (OGFC) pavement and tire is the highest, followed by stone mastic asphalt (SMA) pavement and dense graded asphalt concrete (AC) pavement surface. The vertical contact force between tire and pavement will be greatly reduced, even with increasing speed or water film thickness. As tire speed increases from 70 km/h to 130 km/h, the tire-pavement contact force is reduced by about 25%. Moreover, when the thickness of water film increases from 0 (dry condition) to 4 mm and then to 12 mm, the vertical contact force reduced 50% and 15%, respectively, compared with under the dry contact condition. This study provided a key theoretical reference for safe driving on wet pavements.