37 research outputs found

    Pre-Operative Risk Factors Predict Post-Operative Respiratory Failure after Liver Transplantation

    Get PDF
    OBJECTIVE: Post-operative pulmonary complications significantly affect patient survival rates, but there is still no conclusive evidence regarding the effect of post-operative respiratory failure after liver transplantation on patient prognosis. This study aimed to predict the risk factors for post-operative respiratory failure (PRF) after liver transplantation and the impact on short-term survival rates. DESIGN: The retrospective observational cohort study was conducted in a twelve-bed adult surgical intensive care unit in northern Taiwan. The medical records of 147 liver transplant patients were reviewed from September 2002 to July 2007. Sixty-two experienced post-operative respiratory failure while the remaining 85 patients did not. MEASUREMENTS AND MAIN RESULTS: Gender, age, etiology, disease history, pre-operative ventilator use, molecular adsorbent re-circulating system (MARS) use, source of organ transplantation, model for end-stage liver disease score (MELD) and Child-Turcotte-Pugh score calculated immediately before surgery were assessed for the two groups. The length of the intensive care unit stay, admission duration, and mortality within 30 days, 3 months, and 1 year were also evaluated. Using a logistic regression model, post-operative respiratory failure correlated with diabetes mellitus prior to liver transplantation, pre-operative impaired renal function, pre-operative ventilator use, pre-operative MARS use and deceased donor source of organ transplantation (p<0.05). Once liver transplant patients developed PRF, their length of ICU stay and admission duration were prolonged, significantly increasing their mortality and morbidity (p<0.001). CONCLUSIONS: The predictive pre-operative risk factors significantly influenced the occurrence of post-operative respiratory failure after liver transplantation

    The Parental Non-Equivalence of Imprinting Control Regions during Mammalian Development and Evolution

    Get PDF
    In mammals, imprinted gene expression results from the sex-specific methylation of imprinted control regions (ICRs) in the parental germlines. Imprinting is linked to therian reproduction, that is, the placenta and imprinting emerged at roughly the same time and potentially co-evolved. We assessed the transcriptome-wide and ontology effect of maternally versus paternally methylated ICRs at the developmental stage of setting of the chorioallantoic placenta in the mouse (8.5dpc), using two models of imprinting deficiency including completely imprint-free embryos. Paternal and maternal imprints have a similar quantitative impact on the embryonic transcriptome. However, transcriptional effects of maternal ICRs are qualitatively focused on the fetal-maternal interface, while paternal ICRs weakly affect non-convergent biological processes, with little consequence for viability at 8.5dpc. Moreover, genes regulated by maternal ICRs indirectly influence genes regulated by paternal ICRs, while the reverse is not observed. The functional dominance of maternal imprints over early embryonic development is potentially linked to selection pressures favoring methylation-dependent control of maternal over paternal ICRs. We previously hypothesized that the different methylation histories of ICRs in the maternal versus the paternal germlines may have put paternal ICRs under higher mutational pressure to lose CpGs by deamination. Using comparative genomics of 17 extant mammalian species, we show here that, while ICRs in general have been constrained to maintain more CpGs than non-imprinted sequences, the rate of CpG loss at paternal ICRs has indeed been higher than at maternal ICRs during evolution. In fact, maternal ICRs, which have the characteristics of CpG-rich promoters, have gained CpGs compared to non-imprinted CpG-rich promoters. Thus, the numerical and, during early embryonic development, functional dominance of maternal ICRs can be explained as the consequence of two orthogonal evolutionary forces: pressure to tightly regulate genes affecting the fetal-maternal interface and pressure to avoid the mutagenic environment of the paternal germline

    Cost-Benefit Analysis and Emission Reduction of Energy Efficient Lighting at the Universiti Tenaga Nasional

    No full text
    This paper reports the result of an investigation on the potential energy saving of the lighting systems at selected buildings of the Universiti Tenaga Nasional. The scope of this project includes evaluation of the lighting system in the Library, Admin Building, College of Engineering, College of Information Technology, Apartments, and COE Food court of the university. The main objectives of this project are to design the proper retrofit scenario and to calculate the potential electricity saving, the payback period, and the potential environmental benefits. In this survey the policy for retrofitting the old lighting system with the new energy saving LEDs starts with 10% for the first year and continues constantly for 10 years until all the lighting systems have been replaced. The result of the life cycle analysis reveals that after four years, the selected buildings will bring profit for the investment

    Engine performance and emissions using Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in a CI diesel engine

    No full text
    Biodiesel is a recognized replacement for diesel fuel in compressed ignition engines due to its significant environmental benefits. The purpose of this study is to investigate the engine performance and emissions produced from Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in compressed ignition engine. The biodiesel production process and properties are discussed and a comparison of the three biodiesels as well as diesel fuel is undertaken. After that, engine performance and emissions testing was conducted using biodiesel blends 10%, 20%, 30% and 50% in a diesel engine at full throttle load. The engine performance shows that those biodiesel blends are suitable for use in diesel engines. A 10% biodiesel blend shows the best engine performance in terms of engine torque, engine power, fuel consumption and brake thermal efficiency among the all blending ratios for the three biodiesel blends. Biodiesel blends have also shown a significant reduction in CO2, CO and smoke opacity with a slight increase in NOx emissions

    Synthesis and optimization of Hevea brasiliensis and Ricinus communis as feedstock for biodiesel production: a comparative study

    No full text
    Biodiesel from non-edible seeds has attracted the attention of the authors to investigate Hevea brasiliensis (HB) and Ricinus communis (RC) as potential feedstocks. Biodiesel production was carried out using esterification-neutralization-transesterification (ENT) process. The transesterification process was carried out under variation methanol to oil molar ratio, catalyst concentration, reaction temperature, reaction time and speed agitation. On top of that, optimization was evaluated using Response Surface Methodology (RSM) and a quadratic polynomial model for ENT method. The optimization results show that production biodiesel from HBME and RCME with ENT method were 99.32% and 99.07% respectively. All the properties measured for produced methyl ester met in ASTMD 6751. Moreover, the presence of ricinoleic (α-elaeostearic) in RCME can improve the cold point, pour point and cold filter plugging point, which resulted in -40.4 °C, -27.8 °C and -35.0 °C respectively. The results of the cold flow properties are better due to higher unsaturated fatty acid concentration. It is indicates that RCME has good performance during cold weather engine operation. It short, biodiesel production using ENT method can produce high methyl ester yield and good biodiesel properties

    Recent advancement and assessment of green hydrogen production technologies

    No full text
    Hydrogen energy has garnered substantial support from industry, government, and the public, positioning it as a pivotal future fuel source. However, its commercial realisation faces significant hurdles, including slow infrastructure growth and the high cost of producing clean hydrogen. This review uniquely emphasises the different colour codes of hydrogen, which have been rarely discussed in the literature to date. Hydrogen production methods are classified by colour codes, with green hydrogen, produced from renewable sources such as wind and solar, being the most desirable option. The demand for green hydrogen across various sectors is expected to surge. This review comprehensively evaluates the major hydrogen production methods based on cost, environmental impact, and technological maturity. Recent data confirm the increased efficiency, cost-competitiveness, and scalability of green hydrogen production technologies. The cost of green hydrogen has declined significantly, making it competitive with blue hydrogen (produced from fossil fuels with carbon capture). The review also scrutinises several recent hydrogen production technologies, highlighting their advantages, disadvantages, and technological readiness. Among these, the solid oxide electrolysis cell (SOEC) currently outperforms others, with anion exchange membrane (AEM) and electrified steam methane reforming (ESMR) also showing promise. This review also succinctly summarises global progress in hydrogen infrastructure and policies. By spotlighting the diverse colour codes of hydrogen and discussing the crucial takeaways and implications for the future, this review offers a comprehensive overview of the hydrogen energy landscape. This unique focus enriches the literature and enhances our understanding of hydrogen as a promising energy source.</p

    Bioenergy recovery potential through the treatment of the meat processing industry waste in Australia

    No full text
    The farm animal and meat processing industry generate waste, including manure, fat, blood, sludge, bones, and wastewater, which create environmental problems worldwide. The effluents generated by this industry are rich in proteins, lipids, fibres, and carbohydrates. All these pollutants have the potential to be used as a resource for energy recovery. The organic matters obtained from the farm animal and meat processing industry are critical sources for biogas production via anaerobic digestion. This process leads to the production of energy-rich biogas, reducing greenhouse gas emissions. This study attempts to determine biogas amount and the energy value produced from the farm animal and meat processing industry in Australia. Australia's livestock population mainly consists of dairy cattle, meat cattle, sheep and lambs, pigs, layers, and meat chickens. Results show a potential biogas amount of 23,874,165 million m3 (Mm3), 215,670 Mm3, 288,228 Mm3, 18,430 Mm3, and 392,284 Mm3 can be obtained from cattle, lamb, sheep, pig, and poultry annually, respectively. The methane generated from slaughterhouse waste and wastewater is estimated to provide 4.52E+ 14 MJ/yr of heat energy with total electricity generation potential from livestock wastes of 4.4E+ 13 kWh/yr. About half of the electricity can be generated in Queensland State. Finally, the present study suggests farm animal and meat processing industry effluent as a potential sustainable energy source in Australia. </p
    corecore