Effects of graphite on mechanical properties of stone mastic asphalt pavement

Hot mix asphalt needs to be developed to resist particular permanent deformations like rutting and thermal cracking due to increased traffic volumes and vehicle loads. Additives such as carbon black, graphite, carbon fibers are used in the mixture or the binder for improving the mechanical features of asphalt. In this article, the effects of graphite used for developing the mechanical properties of asphalt have been investigated in mixtures tests. Therefore, Marshall stability, indirect tensile stiffness modulus and indirect tensile fatigue tests were performed to bituminous mixtures modified with three different proportions of graphite by weight of bitumen. Stone mastic asphalt mixtures which were manufactured with pure and modified bitumen were aged in different time intervals in the oven. In conclusion, it has defined that Marshall stability values have declined. It has been determined that there is no significant difference in the time-dependent deformation behavior of the original and aged samples in pure and different graphite content although the stiffness modulus and load repeat number of the samples increased with the rise of the aging time. These results shown that graphite generally used for improving the thermal properties in literature were also determined to contribute to mechanical properties of mixtures

Cold War in Asia: China's Involvement in the Korean and Vietnam War

As essential components of the Cold War, the Korean War and the Vietnam War have played significant roles in global policy among the Western forces under the leadership of the United States and the Eastern bloc led by the Soviet Union in the 20th century. Communist China, founded in 1949, was also part of the countries behind the Iron Curtain and provided substantial support to North Korea and North Vietnam in their fight against their ideological enemies. Despite the extensive research by scholars on the Korean War and the Vietnam War, as well as China’s role in both of these wars, it is interesting to know whether China’s role and attitude had changed from one war to the other. This thesis examines and compares China’s military interference in the Korean War in the beginning of the 1950s with its involvement more than ten years later in the Vietnam War through the investigation of China’s motives to enter the wars and their ways of support in connection with the development of foreign relations. While contrasting China’s role and involvement in Korea and Vietnam, similarities, but also major differences become distinguishable. This thesis argues that these major differences indicate a Chinese rethinking about a possible involvement in Vietnam because of China’s domestic problems and its foreign policy developments at that time

Elevated red blood cell distribution width is associated with intrahepatic cholestasis of pregnancy

Objectives: Intrahepatic cholestasis of pregnancy is the most common pregnancy specific liver disease and related with adverse maternal and perinatal outcome. Red blood cell distribution width, an anisocytosis marker in a complete blood count, has been used as an inflammation marker in various diseases. However the association of red blood cell distribution width with intrahepatic cholestasis of pregnancy is unknown. We aimed to evaluate the relationship between red blood cell distribution width and intrahepatic cholestasis of pregnancy. Material and methods: Ninety pregnant women with intrahepatic cholestasis of pregnancy and ninety healthy pregnant women were included in the study. Their clinical and laboratory characteristics including red blood cell distribution width, liver function tests, fasting and postprandial bile acid concentrations were analyzed. Results: Serum red blood cell distribution width cell levels were significantly higher in pregnants with intrahepatic cholestasis of pregnancy than healthy pregnants. We also demonstrated that red blood cell distribution Width levels were higher in severe disease than mild disease and was significantly correlated with fasting and postprandial bile acid concentration in intrahepatic cholestasis of pregnancy group. Conclusions: Our study showed that red blood cell distribution width, an easy and inexpensive marker; were associated with intrahepatic cholestasis of pregnancy and can be used as a diagnostic and prognostic marker in intrahepatic cholestasis of pregnancy

EXPERIMENTAL INVESTIGATION OF THE STORAGE STABILITY AND RHEOLOGICAL PROPERTIES OF ELASTOMERIC POLYMER MODIFIED BITUMINOUS BINDERS

Bu çalışmada, üç farklı polimer katkılı bitümlü bağlayıcının, yüksek sıcaklık depolama stabilitesi özellikleri araştırılmıştır. Bu amaçla iki farklı tür stiren-butadien-stiren (SBSD), (SBSM) ve stiren-etilen-butadien-stiren (SEBS) katkı malzemesi olarak kullanılmıştır. Üç farklı oranda (%2, 4 ve 6) SBS ve SEBS, 160/220 penetrasyonlu bitüme ilave edilerek modifiye bağlayıcılar elde edilmiştir. Saf ve modifiye bağlayıcılara; yumuşama noktası, dönel viskozimetre (DV) ve dinamik kayma reometresi (DKR) deneyleri uygulanarak katkı maddelerinin etkisi belirlenmiştir. Modifiye bağlayıcıların depolama stabilitesi deneyi EN 13399 standardına göre yapılmıştır. Depolama stabilitesi deneyleri sonucunda, elde edilen numunelere saf ve modifiye bağlayıcılara uygulanan deneyler yeniden uygulanmış ve modifiye bağlayıcıların depolanma özellikleri tespit edilmiştir. Elde edilen sonuçlardan, polimer oranı arttıkça viskozite, yumuşama noktası ve kompleks modülü (G*) değerlerinin arttığı belirlenmiştir. Depolama stabilitesi deneylerinden ve reolojik özelliklerin incelenmesinden en iyi sonuca SBSM katkı maddesinin sahip olduğu belirlenmiştir. In this study the high temperature storage stability properties of bituminous binder modified by three different polymers were investigated. For this purpose two different type of styrene-butadiene-styrene (SBSD), (SBSM) and styrene-ethilene-btadiene-styrene (SEBS) were used. The modified binders were obtained by adding three percentage (2%,4%,6%) of SBS and SEBS to 160/220 penetration grade bitumen. The effects of additive materials were determined by applying the softening point, rotational viscosimeter (RV) and dynamic shear rheometer (DSR) tests to virgin and modified binders. The storage stability test of modified binders were carried out according to EN 13399 standard. The tests applied to pure and modified binders were carried out to specimens obtained from at the end of this processes therefore the storage stability properties of modified binders were determined. According to the obtained results it was determined that the values of viscosity, softening points, and complex modulus (G*) were increased by the increase of polymer content. SBSM gave the best result at the end of the storage stability tests and rheological properties

Histone acetyltransferase NAA40 modulates acetyl-CoA levels and lipid synthesis.

BACKGROUND: Epigenetic regulation relies on the activity of enzymes that use sentinel metabolites as cofactors to modify DNA or histone proteins. Thus, fluctuations in cellular metabolite levels have been reported to affect chromatin modifications. However, whether epigenetic modifiers also affect the levels of these metabolites and thereby impinge on downstream metabolic pathways remains largely unknown. Here, we tested this notion by investigating the function of N-alpha-acetyltransferase 40 (NAA40), the enzyme responsible for N-terminal acetylation of histones H2A and H4, which has been previously implicated with metabolic-associated conditions such as age-dependent hepatic steatosis and calorie-restriction-mediated longevity. RESULTS: Using metabolomic and lipidomic approaches, we found that depletion of NAA40 in murine hepatocytes leads to significant increase in intracellular acetyl-CoA levels, which associates with enhanced lipid synthesis demonstrated by upregulation in de novo lipogenesis genes as well as increased levels of diglycerides and triglycerides. Consistently, the increase in these lipid species coincide with the accumulation of cytoplasmic lipid droplets and impaired insulin signalling indicated by decreased glucose uptake. However, the effect of NAA40 on lipid droplet formation is independent of insulin. In addition, the induction in lipid synthesis is replicated in vivo in the Drosophila melanogaster larval fat body. Finally, supporting our results, we find a strong association of NAA40 expression with insulin sensitivity in obese patients. CONCLUSIONS: Overall, our findings demonstrate that NAA40 affects the levels of cellular acetyl-CoA, thereby impacting lipid synthesis and insulin signalling. This study reveals a novel path through which histone-modifying enzymes influence cellular metabolism with potential implications in metabolic disorders

Hemoglobin is inversely related to flow-mediated dilatation in chronic kidney disease

The microcirculation is regulated by oxygen gradients and by endothelial release of nitric oxide, which can react with hemoglobin to form S-nitroso derivatives. Here we induced flow-mediated dilatation of the brachial artery in response to ischemia in 141 non-diabetic patients with stage 3–4 chronic kidney disease who had no history of smoking, cardiovascular events or use of erythropoietin-based agents. Patients with hemoglobin concentrations above the cohort median of 11.6 g/dl were found to have significant reductions in flow-mediated dilatation compared to those below the median. This inverse relationship remained significant after adjustment for potential confounders, including insulin sensitivity, glomerular filtration rate, proteinuria, body mass index, serum urate, etiology of underlying renal disease, treatment with anti-hypertensive drugs, and traditional Framingham risk factors. Given that hemoglobin can act as an important nitric oxide carrier and buffer, our studies suggest that the mechanism by which hemoglobin influences the endothelium-dependent microcirculation requires its nitrosylation; however, more direct studies need to be performed

FGF-23 and vascular dysfunction in patients with stage 3 and 4 chronic kidney disease

Studies in animals show that fibroblast growth factor (FGF)-23 interferes with vascular reactivity induced by the nitric oxide (NO) system. To investigate the relationship between circulating FGF-23 levels and the response of forearm blood flow to ischemia (flow-mediated vasodilatation, FMD) and nitroglycerin, we tested 183 patients with stage 3-4 chronic kidney disease (CKD). None of them had cardiovascular complications or were taking drugs interfering with vascular function. Patients with FGF-23 levels above the median had significantly lower glomerular filtration rate, FMD, and fetuin-A levels (an anti-inflammatory molecule and potent inhibitor of calcification). They also had higher proteinuria and phosphate levels when compared to patients whose FGF-23 levels were below the median. The response to nitroglycerin was not different between the two groups. Multiple regression analysis showed that the relationship between FGF-23 and FMD was only modestly sensitive to adjustment for classical risk factors, biomarkers of bone mineral metabolism, high-sensitivity C-reactive protein, and homeostatic model assessment index. Adjustment for asymmetrical dimethyl arginine (ADMA) weakened the strength of this link; however, it remained highly significant. There was no independent association between FGF-23 and nitroglycerin. Thus, attenuation of FMD by ADMA suggests that this endogenous inhibitor of NO synthase may, in part, mediate the vascular effects of FGF-23 in patients with CKD. © 2010 International Society of Nephrology