102 research outputs found

    Co-firing of biomass with coals Part 1. Thermogravimetric kinetic analysis of combustion of fir (abies bornmulleriana) wood

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    The chemical composition and reactivity of fir (Abies bornmulleriana) wood under non-isothermal thermogravimetric (TG) conditions were studied. Oxidation of the wood sample at temperatures near 600 A degrees C caused the loss of aliphatics from the structure of the wood and created a char heavily containing C-O functionalities and of highly aromatic character. On-line FTIR recordings of the combustion of wood indicated the oxidation of carbonaceous and hydrogen content of the wood and release of some hydrocarbons due to pyrolysis reactions that occurred during combustion of the wood. TG analysis was used to study combustion of fir wood. Non-isothermal TG data were used to evaluate the kinetics of the combustion of this carbonaceous material. The article reports application of Ozawa-Flynn-Wall model to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustion of the fir wood. The average activation energy related to fir wood combustion was 128.9 kJ/mol, and the average reaction order for the combustion of wood was calculated as 0.30

    Negative Elongation Factor Controls Energy Homeostasis in Cardiomyocytes

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    SummaryNegative elongation factor (NELF) is known to enforce promoter-proximal pausing of RNA polymerase II (Pol II), a pervasive phenomenon observed across multicellular genomes. However, the physiological impact of NELF on tissue homeostasis remains unclear. Here, we show that whole-body conditional deletion of the B subunit of NELF (NELF-B) in adult mice results in cardiomyopathy and impaired response to cardiac stress. Tissue-specific knockout of NELF-B confirms its cell-autonomous function in cardiomyocytes. NELF directly supports transcription of those genes encoding rate-limiting enzymes in fatty acid oxidation (FAO) and the tricarboxylic acid (TCA) cycle. NELF also shares extensively transcriptional target genes with peroxisome proliferator-activated receptor α (PPARα), a master regulator of energy metabolism in the myocardium. Mechanistically, NELF helps stabilize the transcription initiation complex at the metabolism-related genes. Our findings strongly indicate that NELF is part of the PPARα-mediated transcription regulatory network that maintains metabolic homeostasis in cardiomyocytes

    Role of aldosterone on lung structural remodelling and right ventricular function in congestive heart failure

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    <p>Abstract</p> <p>Background</p> <p>The mechanisms of benefit of mineralocorticoid receptors antagonists in congestive heart failure (CHF) are still debated. We hypothesized that aldosterone contributes to pulmonary remodelling and right ventricular (RV) dysfunction associated with CHF by stimulation of lung myofibroblasts (MYFs) proliferation.</p> <p>Methods</p> <p>Rats with moderate to large myocardial infarcts (MI) and CHF were studied. Two weeks after MI, spironolactone 100 mg/kg/day (n = 21) or no treatment (n = 24) were given for 3 weeks and compared to sham (n = 8).</p> <p>Results</p> <p>Infarct size was similar by ultrasound and pathologic measures in both MI groups.</p> <p>The MI-untreated group developed important lung remodelling with nearly doubling of dry lung weight (p < 0.01), reduced left ventricular (LV) fractional shortening (16 ± 2% vs. 53 ± 1%; mean ± SEM, p < 0.0001), pulmonary hypertension (RV systolic pressure: 40 ± 3 mmHg vs. 27 ± 1 mmHg, p < 0.01) and RV hypertrophy (RV/(LV + septum): 38 ± 3% vs. 24 ± 1%, p < 0.05). Spironolactone had no effect on these parameters and did not improve LV or RV performance (tricuspid annular plane systolic excursion and RV myocardial performance index) measured by echocardiography. CHF induced a restrictive respiratory syndrome with histological lung fibrosis: this was also unaffected by spironolactone. Finally, isolated lung MYFs did not proliferate after exposure to aldosterone.</p> <p>Conclusion</p> <p>Aldosterone does not significantly contribute to pulmonary remodelling and RV dysfunction associated with CHF. Other mechanisms are responsible for the beneficial effects of spironolactone in CHF.</p

    Epidemiology of invasive group B streptococcal disease in infants from urban area of South China, 2011–2014

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    YesBackground: Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in infants in both developed and developing countries. To our knowledge, only a few studies have been reported the clinical features, treatment and outcomes of the GBS disease in China. The severity of neonatal GBS disease in China remains unclear. Population-based surveillance in China is therefore required. Methods: We retrospectively collected data of <3 months old infants with culture-positive GBS in sterile samples from three large urban tertiary hospitals in South China from Jan 2011 to Dec 2014. The GBS isolates and their antibiotic susceptibility were routinely identified in clinical laboratories in participating hospitals. Serotyping and multi-locus sequence typing (MLST) were also conducted for further analysis of the neonatal GBS disease. Results: Total 70 cases of culture-confirmed invasive GBS infection were identified from 127,206 live births born in studying hospitals, giving an overall incidence of 0.55 per 1000 live births (95% confidence interval [CI] 0.44–0.69). They consisted of 49 with early-onset disease (EOD, 0.39 per 1000 live births (95% CI 0.29–0.51)) and 21 with late-onset disease (LOD, 0.17 per 1000 live births (95% CI 0.11–0.25)). The incidence of EOD increased significantly over the studying period. Five infants (4 EOD and 1 LOD) died before discharge giving a mortality rate of 7.1% and five infants (7.1%, 2 EOD and 3 LOD) had neurological sequelae. Within 68 GBS isolates from GBS cases who born in the studying hospitals or elsewhere, serotype III accounted for 77.9%, followed by Ib (14.7%), V (4.4%), and Ia (2.9%). MLST analysis revealed the presence of 13 different sequence types among the 68 GBS isolates and ST-17 was the most frequent sequence type (63.2%). All isolates were susceptible to penicillin, ceftriaxone, vancomycin and linezolid, while 57.4% and 51.5% were resistant to erythromycin and clindamycin, respectively. Conclusions: This study gains the insight into the spectrum of GBS infection in south China which will facilitate the development of the guidance for reasonable antibiotics usage and will provide evidence for the implementation of potential GBS vaccines in the future.Supported by medical and health science and technology projects of Health and Family Planning Commission of Guangzhou Municipality (grant number 20151A010034) and Guangdong provincial science and technology planning projects (grant number 2014A020212520)

    Dysregulation of respiratory center drive (P0.1) and muscle strength in patients with early stage idiopathic Parkinson's disease

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    Objective: The goal of this study is to evaluate pulmonary function and respiratory center drive in patients with early-stage idiopathic Parkinson's disease (IPD) to facilitate early diagnosis of Parkinson's Disease (PD). Methods: 43 IPD patients (Hoehn and Yahr scale of 1) and 41 matched healthy individuals (e.g., age, sex, height, weight, BMI) were enrolled in this study. Motor status was evaluated using the Movement Disorders Society-Unified PD Rating Scale (MDS-UPDRS). Pulmonary function and respiratory center drive were measured using pulmonary function tests (PFT). All IPD patients were also subjected to a series of neuropsychological tests, including Non-Motor Symptoms Questionnaire (NMSQ), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), Beck Depression Inventory (BDI) and Mini Mental State Examination (MMSE). Results: IPD patients and healthy individuals have similar forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), forced expiratory volume in 1s/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and carbon monoxide diffusion capacity (DLCOcSB). Reduced respiratory muscle strength, maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) was seen in IPD patients (p = 0.000 and p = 0.002, respectively). Importantly, the airway occlusion pressure after 0.1 s (P0.1) and respiratory center output were notably higher in IPD patients (p = 0.000) with a remarkable separation of measured values compared to healthy controls. Conclusion: Our findings suggest that abnormal pulmonary function is present in early stage IPD patients as evidenced by significant changes in PImax, PEmax, and P0.1. Most importantly, P0.1 may have the potential to assist with the identification of IPD in the early stage

    Influence of Road Cross Section on Access Spacing

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    This report presents a study on the influences of select cross-sectional-related design elements (specifically median configurations and bicycle lanes) and their impact on crash severity and type, as well as the associated driver gap acceptance for turning maneuvers at midblock driveway locations on urban arterials. The primary goal of this proposed research is to better understand how the median and bicycle lane configurations can influence safety and operations at driveway locations. The research team utilized crash data, traffic data, and roadway information from driveway locations in the U.S. states of Oregon, Arkansas and Oklahoma. The project team supplemented the data with digital videos acquired during field studies of the sites. The traffic videos helped the research team better understand how road features and traffic influenced driver behavior at selected urban arterial driveway locations. As part of this effort, the research team conducted gap-acceptance studies to determine the critical gaps for driveway locations at arterial roads with and without bicycle lanes. The research team evaluated four different critical gap analysis methods to estimate the driveway operations and noted potential procedural biases associated with two of the techniques. The report describes these field studies and summarizes how the gap acceptance varied at the different arterial driveway locations. The research team also performed simulation analysis in CORSIM in order to examine the influence that median type, traffic volume, and access density have on traffic operational performance
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