61 research outputs found

    A Mild Dyssynchronous Contraction Pattern Detected by SPECT Myocardial Perfusion Imaging Predicts Super-Response to Cardiac Resynchronization Therapy

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    Background: Using single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) with phase analysis (PA), we aimed to identify the predictive value of a new contraction pattern in cardiac resynchronization therapy (CRT) response. Methods: Left ventricular mechanical dyssynchrony (LVMD) was evaluated using SPECT MPI with PA in non-ischemic dilated cardiomyopathy (DCM) patients with left bundle branch block (LBBB) indicated for CRT. CRT super-response was defined as LV ejection fraction (EF) ≥50% or an absolute increase of LVEF \u3e15%. The LV contraction was categorized as the mild dyssynchronous pattern when the phase standard deviation (PSD) ≤ 40.3° and phase histogram bandwidth (PBW) ≤ 111.9°, otherwise it was defined as severe dyssynchronous pattern which was further characterized as U-shaped, heterogeneous or homogenous pattern. Results: The final cohort comprised 74 patients, including 32 (43.2%) in mild dyssynchronous group, 17 (23%) in U-shaped group, 19 (25.7%) in heterogeneous group, and 6 (8.1%) in homogenous group. The mild dyssynchronous group had lower PSD and PBW than U-shaped, heterogeneous, and homogenous groups ( \u3c 0.0001). Compared to patients with the heterogeneous pattern, the odds ratios (ORs) with 95% confidence intervals (CIs) for CRT super-response were 10.182(2.43-42.663), 12.8(2.545-64.372), and 2.667(0.327-21.773) for patients with mild dyssynchronous, U-shaped, and homogenous pattern, respectively. After multivariable adjustment, mild dyssynchronous group remained associated with increased CRT super-response (adjusted OR 5.709, 95% CI 1.152-28.293). Kaplan-Meier curves showed that mild dyssynchronous group demonstrated a better long-term prognosis. Conclusions: The mild dyssynchronous pattern in patients with DCM is associated with an increased CRT super-response and better long-term prognosis

    A new method using deep transfer learning on ECG to predict the response to cardiac resynchronization therapy

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    Background: Cardiac resynchronization therapy (CRT) has emerged as an effective treatment for heart failure patients with electrical dyssynchrony. However, accurately predicting which patients will respond to CRT remains a challenge. This study explores the application of deep transfer learning techniques to train a predictive model for CRT response. Methods: In this study, the short-time Fourier transform (STFT) technique was employed to transform ECG signals into two-dimensional images. A transfer learning approach was then applied on the MIT-BIT ECG database to pre-train a convolutional neural network (CNN) model. The model was fine-tuned to extract relevant features from the ECG images, and then tested on our dataset of CRT patients to predict their response. Results: Seventy-one CRT patients were enrolled in this study. The transfer learning model achieved an accuracy of 72% in distinguishing responders from non-responders in the local dataset. Furthermore, the model showed good sensitivity (0.78) and specificity (0.79) in identifying CRT responders. The performance of our model outperformed clinic guidelines and traditional machine learning approaches. Conclusion: The utilization of ECG images as input and leveraging the power of transfer learning allows for improved accuracy in identifying CRT responders. This approach offers potential for enhancing patient selection and improving outcomes of CRT

    COMBINED EFFECTS OF SULFATE AND CHLORIDE ATTACK ON STEEL REINFORCED MORTAR UNDER DRYING–IMMERSION CYCLES

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    In this study, X-ray microcomputed tomography (XCT) and nanoindentation techniques were used to evaluate the synergistic action between sulfate and chloride ingress under cyclic drying–immersion conditions on steel-reinforced mortars. Three salt solutions, namely 3% NaCl (Sc), 5% Na2SO4 (Ss), and 5% Na2SO4 + 3% NaCl (Scs), were used and 24 drying–immersion cycles were applied. The results showed that the chloride caused more severe corrosion on steel reinforcement than the sulfate while under the influence of Scs, and the presence of sulfate suppressed the steel corrosion caused by chloride. In terms the damage to the mortar cover, after 24 drying–immersion cycles, the sulfate caused the most severe damage (volume loss of approximately 7.1%) while the chloride resulted in the least damage (volume loss of approximately 2.6%). By comparing Ss and Scs, it was also found that chloride suppressed the sulfate attack by reducing the damage to the mortar cover (volume loss of approximately 6.3% for Scs). Moreover, the degradation of mortar specimens was found to be layer-dependent, as was the distribution of micro-mechanics. Regarding the micro-mechanics, the specimens of the three solutions performed differently in terms of the aforementioned properties, depending on which underlying mechanism was analyzed. This research could allow for a more accurate assessment of the factors influencing building structures in a typical aggressive marine environment. Keywords: Portland cement mortar; sulfate; chloride; drying–immersion cycle; XCT; nanoindentatio

    White matter hyperintensities burden in the frontal regions is positively correlated to the freezing of gait in Parkinson’s disease

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    ObjectivePrevious studies have reported that white matter hyperintensities (WMHs) are associated with freezing of gait (FOG), but it is not clear whether their distribution areas have correlations with FOG in Parkinson’s disease (PD) and the potential influencing factors about WMHs.MethodsTwo hundred and forty-six patients with PD who underwent brain MRI were included. Participants were divided into PD with FOG (n = 111) and PD without FOG (n = 135) groups. Scheltens score was used to assess the WMHs burden in the areas of deep white matter hyperintensities (DWMHs), periventricular hyperintensities (PVHs), basal ganglia hyperintensities (BGHs), and infratentorial foci of hyperintensities (ITF). Whole brain WMHs volume was evaluated by automatic segmentation. Binary logistic regression was used to evaluate relationships between WMHs and FOG. The common cerebrovascular risk factors that may affect WMHs were evaluated by mediation analysis.ResultsThere were no statistical differences between PD with and without FOG groups in whole brain WMHs volume, total Scheltens score, BGHs, and ITF. Binary logistic regression showed that the total scores of DWMHs (OR = 1.094; 95% CI, 1.001, 1.195; p = 0.047), sum scores of PVHs and DWMHs (OR = 1.080; 95% CI, 1.003, 1.164; p = 0.042), especially the DWMHs in frontal (OR = 1.263; 95% CI, 1.060, 1.505 p = 0.009), and PVHs in frontal caps (OR = 2.699; 95% CI, 1.337, 5.450; p = 0.006) were associated with FOG. Age, hypertension, and serum alkaline phosphatase (ALP) are positively correlated with scores of DWMHs in frontal and PVHs in frontal caps.ConclusionThese results indicate that WMHs distribution areas especially in the frontal of DWMHs and PVHs play a role in PD patients with FOG

    Phage vB_PaeS-PAJD-1 Rescues Murine Mastitis Infected With Multidrug-Resistant Pseudomonas aeruginosa

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    Pseudomonas aeruginosa is a Gram-negative pathogen that causes a variety of infections in humans and animals. Due to the inappropriate use of antibiotics, multi-drug resistant (MDR) P. aeruginosa strains have emerged and are prevailing. In recent years, cow mastitis caused by MDR P. aeruginosa has attracted attention. In this study, a microbial community analysis revealed that P. aeruginosa could be a cause of pathogen-induced cow mastitis. Five MDR P. aeruginosa strains were isolated from milk diagnosed as mastitis positive. To seek an alternative antibacterial agent against MDR, P. aeruginosa, a lytic phage, designated vB_PaeS_PAJD-1 (PAJD-1), was isolated from dairy farm sewage. PAJD-1 was morphologically classified as Siphoviridae and was estimated to be about 57.9 kb. Phage PAJD-1 showed broad host ranges and a strong lytic ability. A one-step growth curve analysis showed a relatively short latency period (20 min) and a relatively high burst size (223 PFU per infected cell). Phage PAJD-1 remained stable over wide temperature and pH ranges. Intramammary-administered PAJD-1 reduced bacterial concentrations and repaired mammary glands in mice with mastitis induced by MDR P. aeruginosa. Furthermore, the cell wall hydrolase (termed endolysin) from phage PAJD-1 exhibited a strong bacteriolytic and a wide antibacterial spectrum against MDR P. aeruginosa. These findings present phage PAJD-1 as a candidate for phagotherapy against MDR P. aeruginosa infection

    Store-operated Ca 2+

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    Electronic and Magnetic Properties Studies on Mn and Oxygen Vacancies Codoped Anatase TiO2

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    The electronic and magnetic properties of Mn and oxygen vacancies codoped anatase TiO2 were investigated. The calculated results showed that the TiO2 codoped with Mn and oxygen vacancies have a magnetic moment value of 3.415 μB per Ti31MnO63 supercell. Furthermore, Ti31MnO63 gets the lowest energy with a geometrical optimization where the Mn ions locate at the nearest-neighbor sites of the oxygen vacancy. And experimental results indicated the magnetism is associated with the defects of Mn ions and oxygen vacancies induced by the Mn doping, which is consistent with the calculation results

    An Automatic Classification Method of Well Testing Plot Based on Convolutional Neural Network (CNN)

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    The precondition of well testing interpretation is to determine the appropriate well testing model. In numerous attempts in the past, automatic classification and identification of well testing plots have been limited to fully connected neural networks (FCNN). Compared with FCNN, the convolutional neural network (CNN) has a better performance in the domain of image recognition. Utilizing the newly proposed CNN, we develop a new automatic identification approach to evaluate the type of well testing curves. The field data in tight reservoirs such as the Ordos Basin exhibit various well test models. With those models, the corresponding well test curves are chosen as training samples. One-hot encoding, Xavier normal initialization, regularization technique, and Adam algorithm are combined to optimize the established model. The evaluation results show that the CNN has a better result when the ReLU function is used. For the learning rate and dropout rate, the optimized values respectively are 0.005 and 0.4. Meanwhile, when the number of training samples was greater than 2000, the performance of the established CNN tended to be stable. Compared with the FCNN of similar structure, the CNN is more suitable for classification of well testing plots. What is more, the practical application shows that the CNN can successfully classify 21 of the 25 cases

    Association of X-ray Repair Cross Complementing Group 1 Arg399Gln Polymorphisms with the Risk of Squamous Cell Carcinoma of the Head and Neck: Evidence from an Updated Meta-Analysis

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    <div><p>Background</p><p>Epidemiologic studies have reported the association of X-ray repair cross-complementary group 1 (<i>XRCC1</i>) Arg399Gln polymorphisms with susceptibility to squamous cell carcinoma of the head and neck (HNSCC). However, the results were conflictive rather than conclusive. The purpose of this study was to clarify the association of <i>XRCC1</i> Arg399Gln variants with HNSCC risk.</p><p>Methods</p><p>Systematic searches were performed through the search engines of PubMed, Elsevier, Science Direct, CNKI and Chinese Biomedical Literature Database. Summary odds ratio (OR) with 95% confidence intervals (CI) was computed to estimate the strength association.</p><p>Results</p><p>Overall, we did not observe any association of <i>XRCC1</i> Arg399Gln polymorphisms with HNSCC risk in total population (OR = 0.95, 95% CI: 0.76–1.19 for Gln/Gln vs. Arg/Arg, OR = 1.05, 95% CI: 0.92–1.20 for Arg/Gln vs. Arg/Arg, and OR = 1.03, 95% CI: 0.90–1.18 for Gln/Gln+Arg/Gln vs. Arg/Arg) based on 18 studies including 3917 cases and 4560 controls. In subgroup analyses, we observed an increased risk of <i>XRCC1</i> 399 Arg/Gln genotype for HNSCC in Caucasians (OR = 1.20, 95% CI: 1.00–1.44) and Gln/Gln genotype for larynx squamous cell carcinoma (OR = 1.63, 95% CI: 1.10–2.40). We did not observe any association between <i>XRCC1</i> Arg399Gln variants and HNSCC risk in additional subgroup analyses.</p><p>Conclusion</p><p>The results from this present meta-analysis suggest that <i>XRCC1</i> Arg399Gln variants may contribute to HNSCC risk among Caucasians and to the risk of larynx squamous cell carcinoma. Further, well-designed studies with larger sample sizes are required to verify our findings.</p></div

    A structural equation modelling analysis: interprofessional team collaboration, organizational career management, and post competency of community nurses

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    Abstract Background With the advent of an ageing society and an increase in the prevalence of chronic diseases, the role of primary health care has become increasingly important and reliant on multidisciplinary collaboration. As members of this interprofessional cooperative team, community nurses play a dominant role. Thus, the post competencies of community nurses study deserve our attention. In addition, organizational career management can affect nurses in some ways. This study aims to examine the current situation and relationship among interprofessional team collaboration, organizational career management and post-competency of community nurses. Methods A survey was conducted among 530 nurses in 28 community medical institutions from November 2021 to April 2022 in Chengdu, Sichuan Province, China. Descriptive analysis was used for analysis, and a structural equation model was used to hypothesize and verify the model. A total of 88.2% of respondents met the inclusion criteria and did not meet the exclusion criteria. The main reason nurses gave for not participating was that they were too busy. Results Among the competencies on the questionnaire, ensuring quality and helping roles scored the lowest. The teaching-coaching and diagnostic functions played a mediating role. Nurses with greater seniority and those who were transferred to administrative departments had lower scores, and the difference was statistically significant (p < 0.05). In the structural equation model, CFI = 0.992 and RMSEA = 0.049, which shows that the model fit well, suggesting that organizational career management had no statistically significant effect on post competency (β = -0.006, p = 0.932) but that interprofessional team collaboration had a statistically significant effect on post competency (β = 1.146, p < 0.001) and organizational career management had a statistically significant effect on interprofessional team collaboration (β = 0.684, p < 0.001). Conclusions Attention should be given to the improvement of community nurses' post competency in ensuring quality and performing helping, teaching-coaching, and diagnostic roles. Moreover, researchers should focus on the decline in community nurses' abilities, particularly for those with greater seniority or in administrative roles. The structural equation model shows that interprofessional team collaboration is a complete intermediary between organizational career management and post competency
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