172 research outputs found

    ANALYSIS OF COCONUT ETHYL ESTER (BIODIESEL) AND FOSSIL DIESEL BLENDING: PROPERTIES AND CORROSION CHARACTERISTICS

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    The effect of biodiesel and its blends synthesized from coconut oil (CNO) via alkali catalyzed transeterification on the key fuel properties and corrosion characteristics of copper were investigated. The transesterification of the CNO via ethanol in the presence of potassium hydroxide was performed and the resulting coconut oil ethyl ester (COEE) was blended with fossil diesel (B0).  The fuel properties such as density, kinematic viscosity (KV), pour and cloud points (PP and CP, respectively) and American Petroleum Institute of Gravity (API) of B0, COEE-diesel blend (B50) and COEE (B100) were characterized and compared with that of ASTM D6751 and EN14214 standards. Static immersion tests were conducted by exposing copper coupons toB0, B50 and B100 at different temperatures (50, 65 and 80 oC) for 5 days.  Corrosion rates of copper in these fuels were determined by weight loss method. Also, during the period of investigation, these fuels were analyzed by measuring total acid number (TAN). The results showed that the density, KV, PP and CPincreased while the API gravity decreased as the percentage of the biodiesel in the blend increased. The highest corrosion rates for copper at the end of the investigation were 0.054, 0.0954 and 0.139 mpy in B0, B50 and B100, respectively. The minimum TAN (0.17 mg KOH/g) and maximum TAN (0.62 mg KOH/g) were observed in B0 and B100 containing copper, respectively. http://dx.doi.org/10.4314/njt.v35i1.1

    Spectroscopic ellipsometry studies of HF treated Si (100) surfaces

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    Both ex situ and in situ spectroscopic ellipsometry (SE) measurements were employed to investigate the effects of HF cleaning on Si surfaces. The hydrogen-terminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that after a 20-s 9:1 HF dip without rinse, the Si(100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si(100) surface was observed, in an ultrahigh vacuum (UHV) chamber, and analyzed by the in situ SE. Evidence for desorption of the H-terminated Si surface-layer, after being heated to approximately 550 C in the UHV chamber, is presented and discussed. This is the first use of an ex situ and in situ real-time, nondestructive technique capable of showing state of passivation, the rate of reoxidation, and the surface roughness of the H-terminated Si surfaces

    High-sensitivity cardiac troponin I improves cardiovascular risk prediction in older men: HIMS (The Health in Men Study)

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    Background: The Framingham Risk Score estimates the 10-year risk of cardiovascular events. However, it performs poorly in older adults. We evaluated the incremental benefit of adding high-sensitivity cardiac troponin I (hs-cTnI) to the Framingham Risk Score. Methods and Results: The HIMS (Health in Men Study) is a cohort study of community-dwelling men aged 70 to 89 years in Western Australia. Participants were identified from the electoral roll, with a subset undergoing plasma analysis. Hs-cTnI (Abbott Architect i2000SR) was measured in 1151 men without prior cardiovascular disease. The Western Australia Data Linkage System was used to identify incident cardiovascular events. After 10 years of follow-up, 252 men (22%) had a cardiovascular event (CVE+) and 899 did not (CVE–). The Framingham Risk Score placed 148 (59%) CVE+ and 415 (46%) CVE– in the high-risk category. In CVE– men, adding hs-cTnI affected the risk categories of 244 (27.2%) men, with 64.8% appropriately reclassified to a lower and 35.2% to a higher category, which decreased the number of high-risk men in the CVE– to 39%. In CVE+ men, adding hs-cTnI affected the risk categories of 61 (24.2%), with 50.8% appropriately reclassified to a higher and 49.2% to a lower category and 82.5% remaining above the 15% risk treatment threshold. The net reclassification index was 0.305 (P<0.001). Adding hs-cTnI increased the C-statistic modestly from 0.588 (95% CI, 0.552–0.624) to 0.624 (95% CI, 0.589–0.659) and improved model fit (likelihood ratio test, P<0.001). Conclusions: Adding hs-cTnI to the Framingham Risk Score provided incremental prognostic benefit in older men, especially aiding reclassification of individuals into a lower risk category

    Corrigendum: Evolution, ecology, and zoonotic transmission of betacoronaviruses: A review

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    In the published article, there was an error in the legend for Figure 1 as published. The figure legend did not indicate that it has been adapted from Plowright et al. (2017). Copyright permission was obtained from Springer Nature to adapt Figure 1 from Plowright et al. (2017). The corrected legend appears below. Figure 1. Zoonotic risk distribution, pathway to spillover, and the multimodal role of the determinants of spillover. The zoonotic risk is demonstrated by the accumulated distribution of reservoir hosts and vectors that play a role in the pathway to spillover. The risk of spillover is determined by a series of processes from the ecological dynamics of reservoir host distribution and density, to the susceptibility, replication and dissemination of the biological factors in the recipient host. This is also reflected in the multimodal role of the determinants of spillover, demonstrating the disciplines that are being used to study zoonotic transmission and the determinants of spillover. This figure was adapted from Figure 1 in Plowright et al. (2). Copyright permission was obtained with license number 55218980848529. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

    Fibrosis in the kidney: is a problem shared a problem halved?

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    Fibrotic disorders are commonplace, take many forms and can be life-threatening. No better example of this exists than the progressive fibrosis that accompanies all chronic renal disease. Renal fibrosis is a direct consequence of the kidney's limited capacity to regenerate after injury. Renal scarring results in a progressive loss of renal function, ultimately leading to end-stage renal failure and a requirement for dialysis or kidney transplantation

    Co-assembling living material as an in vitro lung epithelial infection model

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    Biofilms are robust living 3D materials that play key roles in nature but also cause major problems, such as tolerance to antibiotic treatment. Recreation of these living structures in vitro is critical to understand their biology and develop solutions to the problems they cause. However, growing 3D biofilms in vitro is difficult primarily because of the limitations in developing matrices that mimic the inherent structural and compositional complexity of their extracellular milieu. Here, we report a living material based on the co-assembly of artificial sputum medium with bioactive peptide amphiphiles. We demonstrate its capacity to support the growth of 3D polymicrobial biofilms and build an interkingdom infected lung epithelial model to study the impact of the antibiotic ciprofloxacin. Our study offers a living material capable of growing functional 3D biofilms that simulate in vitro the nutritional and mechanical properties of these systems in vivo

    Palmitoleate Induces Hepatic Steatosis but Suppresses Liver Inflammatory Response in Mice

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    The interaction between fat deposition and inflammation during obesity contributes to the development of non-alcoholic fatty liver disease (NAFLD). The present study examined the effects of palmitoleate, a monounsaturated fatty acid (16∶1n7), on liver metabolic and inflammatory responses, and investigated the mechanisms by which palmitoleate increases hepatocyte fatty acid synthase (FAS) expression. Male wild-type C57BL/6J mice were supplemented with palmitoleate and subjected to the assays to analyze hepatic steatosis and liver inflammatory response. Additionally, mouse primary hepatocytes were treated with palmitoleate and used to analyze fat deposition, the inflammatory response, and sterol regulatory element-binding protein 1c (SREBP1c) activation. Compared with controls, palmitoleate supplementation increased the circulating levels of palmitoleate and improved systemic insulin sensitivity. Locally, hepatic fat deposition and SREBP1c and FAS expression were significantly increased in palmitoleate-supplemented mice. These pro-lipogenic events were accompanied by improvement of liver insulin signaling. In addition, palmitoleate supplementation reduced the numbers of macrophages/Kupffer cells in livers of the treated mice. Consistently, supplementation of palmitoleate decreased the phosphorylation of nuclear factor kappa B (NF-κB, p65) and the expression of proinflammatory cytokines. These results were recapitulated in primary mouse hepatocytes. In terms of regulating FAS expression, treatment of palmitoleate increased the transcription activity of SREBP1c and enhanced the binding of SREBP1c to FAS promoter. Palmitoleate also decreased the phosphorylation of NF-κB p65 and the expression of proinflammatory cytokines in cultured macrophages. Together, these results suggest that palmitoleate acts through dissociating liver inflammatory response from hepatic steatosis to play a unique role in NAFLD
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