53 research outputs found
Effect of ammonium bisulphite and chloride on the pitting and stress corrosion cracking resistance of super duplex stainless steel pipes under combined internal pressure and axial tension
The financial support of Shell UK is acknowledged. The authors would like to thank the following technical staff, Stuart Herbert, Alistair Robertson for the machining of the mini pipes, Derek Logan, and Irene Brand for resolving several electrical issues and providing accessories, and Jim Gall for help with the test setâup and prompt supply of tools and equipment.Peer reviewedPostprin
Effect of Aronia melanocarpa fruit juice on glucose tolerance, lipid metabolism, and obesity in a rat model of metabolic syndrome
Abstract Metabolic syndrome (MS) is a serious health condition. The purpose of this study was to investigate the effects of polyphenol-rich Aronia melanocarpa fruit juice (AMFJ) on glucose tolerance, triglyceride levels, and adipose tissue in rats with MS induced by high-fat high-fructose (HFHF) diet. Fifty rats were allocated in 5 groups: control, MS, MS+AMFJ2.5, MS+AMFJ5, and MS+AMFJ10. In the course of 10 weeks, the control group was on a regular rat diet while the other groups received HFHF diet. During the experiment, control and MS groups were treated daily orally with distilled water (10.0 mL kgâ1) and the other three groups â with AMFJ at doses of 2.5, 5.0, and 10.0 mL kgâ1, respectively. In MS rats, glucose intolerance, hypertriglyceridemia, visceral obesity, and increased adipocyte size were observed. In AMFJ-treated groups, the serum glucose and triglycerides, as well as visceral fat and adipocyte size decreased significantly and did not differ from those of the control group. AMFJ at doses 2.5 and 5.0 mL kgâ1 showed an anti-apoptotic activity in adipocytes, while at the dose of 10 mL kgâ1 a pro-apoptotic effect was detected. In conclusion, AMFJ could antagonise most of the negative consequences of HFHF diet on carbohydrate and lipid metabolism in a rat MS model
Engineering of III-Nitride Semiconductors on Low Temperature Co-fired Ceramics
This work presents results in the feld of advanced substrate solutions in order to achieve high
crystalline quality group-III nitrides based heterostructures for high frequency and power devices or for
sensor applications. With that objective, Low Temperature Co-fred Ceramics has been used, as a noncrystalline
substrate. Structures like these have never been developed before, and for economic reasons
will represent a groundbreaking material in these felds of Electronic. In this sense, the report presents
the characterization through various techniques of three series of specimens where GaN was deposited
on this ceramic composite, using diferent bufer layers, and a singular metal-organic chemical vapor
deposition related technique for low temperature deposition. Other single crystalline ceramic-based
templates were also utilized as substrate materials, for comparison purposes
Cerebral Metabolic Alterations in Rats With Diabetic Ketoacidosis: Effects of Treatment With Insulin and Intravenous Fluids and Effects of Bumetanide
ObjectiveCerebral edema is a life-threatening complication of diabetic ketoacidosis (DKA) in children. Recent data suggest that cerebral hypoperfusion and activation of cerebral ion transporters may be involved, but data describing cerebral metabolic alterations during DKA are lacking.Research design and methodsWe evaluated 50 juvenile rats with DKA and 21 normal control rats using proton and phosphorus magnetic resonance spectroscopy (MRS). MRS measured cerebral intracellular pH and ratios of metabolites including ATP/inorganic phosphate (Pi), phosphocreatine (PCr)/Pi, N-acetyl aspartate (NAA)/creatine (Cr), and lactate/Cr before and during DKA treatment. We determined the effects of treatment with insulin and intravenous saline with or without bumetanide, an inhibitor of Na-K-2Cl cotransport, using ANCOVA with a 2 x 2 factorial study design.ResultsCerebral intracellular pH was decreased during DKA compared with control (mean +/- SE difference -0.13 +/- 0.03; P < 0.001), and lactate/Cr was elevated (0.09 +/- 0.02; P < 0.001). DKA rats had lower ATP/Pi and NAA/Cr (-0.32 +/- 0.10, P = 0.003, and -0.14 +/- 0.04, P < 0.001, respectively) compared with controls, but PCr/Pi was not significantly decreased. During 2-h treatment with insulin/saline, ATP/Pi, PCr/Pi, and NAA/Cr declined significantly despite an increase in intracellular pH. Bumetanide treatment increased ATP/Pi and PCr/Pi and ameliorated the declines in these values with insulin/saline treatment.ConclusionsThese data demonstrate that cerebral metabolism is significantly compromised during DKA and that further deterioration occurs during early DKA treatment--consistent with possible effects of cerebral hypoperfusion and reperfusion injury. Treatment with bumetanide may help diminish the adverse effects of initial treatment with insulin/saline
Short-term acclimation in adults does not predict offspring acclimation potential to hypoxia
Abstract The prevalence of hypoxic areas in coastal waters is predicted to increase and lead to reduced biodiversity. While the adult stages of many estuarine invertebrates can cope with short periods of hypoxia, it remains unclear whether that ability is present if animals are bred and reared under chronic hypoxia. We firstly investigated the effect of moderate, short-term environmental hypoxia (40% air saturation for one week) on metabolic performance in adults of an estuarine amphipod, and the fitness consequences of prolonged exposure. We then reared the offspring of hypoxia-exposed parents under hypoxia, and assessed their oxyregulatory ability under declining oxygen tensions as juveniles and adults. Adults from the parental generation were able to acclimate their metabolism to hypoxia after one week, employing mechanisms typically associated with prolonged exposure. Their progeny, however, did not develop the adult pattern of respiratory regulation when reared under chronic hypoxia, but instead exhibited a poorer oxyregulatory ability than their parents. We conclude that species apparently hypoxia-tolerant when tested in short-term experiments, could be physiologically compromised as adults if they develop under hypoxia. Consequently, we propose that the increased prevalence of hypoxia in coastal regions will have marked effects in some species currently considered hypoxia tolerant
Engineering of III-nitride semiconductors on low temperature Co-fired ceramics
This work presents results in the field of advanced substrate solutions in order to achieve high crystalline quality group-III nitrides based heterostructures for high frequency and power devices or for sensor applications. With that objective, Low Temperature Co-fired Ceramics has been used, as a non-crystalline substrate. Structures like these have never been developed before, and for economic reasons will represent a groundbreaking material in these fields of Electronic. In this sense, the report presents the characterization through various techniques of three series of specimens where GaN was deposited on this ceramic composite, using different buffer layers, and a singular metal-organic chemical vapor deposition related technique for low temperature deposition. Other single crystalline ceramic-based templates were also utilized as substrate materials, for comparison purposes
Variation between countries in the frequency of diabetic ketoacidosis at first presentation of type 1 diabetes in children: a systematic review
Niklas Luhmannâs Magnificent Contribution to the Sociological Tradition: The Emergence of the Knowledge-Based Economy as an Order of Expectations
One can discard Luhmannâs contributions as flawed (e.g., Padgett & Powell, 2012, pp. 55-58) or discuss the limitations of the theory from a sociological perspective (e.g., Giddens, 1984, at p. xxxvi f.; Leydesdorff, 2010), but in my opinion, important steps were made by Luhmann in sociological theorizing when compared with his predecessors such as Parsons and Habermas, but also when compared with more empirically oriented contemporaries such as Merton and Giddens. These new developments were made possible by an interdisciplinary orientation in which Luhmann absorbed into his sociology, on the one side, Maturanaâs theory of autopoiesis (self-organization) and, on the other, Husserlâs philosophy, and then provided a sociological reconstruction that can eventually be operationalized (Leydesdorff, 1996 and 2012). In my opinion, these new steps in terms of sociological theorizing were made mainly in the 1970s and 1980s, whereas the emphasis shifted to a synthesis of this oeuvre in the 1990s (e.g., Luhmann, 1997) and to the more philosophical ambition of developing a general theory of observation (Baecker et al., [1992] 1999; Gumbrecht, 2003 and 2006; Leydesdorff, 2006)
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