24 research outputs found
Efecto de annealing sobre las propiedades estructurales, térmicas y mecánicas de la composición de aleación binaria Al85 Ni 15
Introduction: The Al 85-Ni15 alloy with 99.99% purity of Al and Ni were prepared by an arc melting technique system. The annealing effect onthe microstructure properties, phase transformation and micro-hardness for the Al-Ni alloy system were investigated. Material and Methods:The alloys were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA) as well as Vickers micro-hardness measurement. Results and Discussion: The quantitative results confirm that the chemical composition of the alloys is very close to compositions and the microstructures are in typical lamellar morphology. Mechanical properties for the as-prepared samples and subsequently heat-treated samples were measured by a Vickers indenter. Values of the micro-hardness (HV) Conclusions: According the XRD pattern analysis a multi phases produced, such as Al, AlNi3in room temperature, Al3Ni2, Al0.42Ni0.58 at 200ºC, Al1.1Ni0.9 at 300ºC and Al 0.802Ni0.198, AlNi3 and AlNi at 400ºC, and Al0.802Ni0.198, AlNi3 and AlNi for 500ºC. Similar approached were obtained from the results of SEM and DTA measurements. Annealing treatments are visibly affecting the alloy phase formation with different phases at different temperature. and the elastic modulus (E) of the as prepared sample are 132.9±0.1 kgfmm-2 (1.329±0.1 GPa) and 80.340±0.1 GPa, respectively. Furthermore, the characteristic of the materials plasticity (δH) value was calculated to be 0.85. The micro-hardness values are decrease with the increase of annealing temperatures
Effects of weight loss and long-term weight maintenance with diets varying in protein and glycemic index on cardiovascular risk factors: the diet, obesity, and genes (DiOGenes) study: a randomized, controlled trial
BACKGROUND:
We sought to separately examine the effects of either weight loss or diets varying in protein content and glycemic index without further changes in body weight on cardiovascular risk factors within the Diet, Obesity, and Genes study (DiOGenes).
METHODS AND RESULTS:
DiOGenes is a pan-European controlled dietary intervention study in 932 overweight adults who first lost body weight on an 8-week low-calorie diet and were then randomized to 1 of 5 ad libitum diets for 26 weeks. The diets were either high or low protein or high or low glycemic index in 4 combinations or control. Weight loss (-11.23 kg; 95% confidence interval, -11.54 to -10.92; P<0.001) reduced high-sensitivity C-reactive protein (-1.15 mg/L; 95% confidence interval, -1.30 to -0.41; P<0.001), low- and high-density lipoprotein cholesterol, triglycerides, and blood pressure. During the 26-week weight maintenance period in the intention-to-treat analysis, the further decrease of high-sensitivity C-reactive protein blood levels was -0.46 mg/L greater (95% confidence interval, -0.79 to -0.13) in the groups assigned to low-glycemic-index diets than in those on high-glycemic-index diets (P<0.001). Groups on low-protein diets achieved a -0.25 mg/L greater reduction in high-sensitivity C-reactive protein (95% confidence interval, -0.59 to -0.17) than those on high-protein diets (P<0.001), whereas lipid profiles and blood pressure were not differently affected.
CONCLUSIONS:
This large-scale intervention study clearly separates weight loss from dietary composition-related effects. Low-glycemic-index carbohydrates and, to a lesser extent, low-protein intake may specifically reduce low-grade inflammation and associated comorbidities in overweight/obese adults
Is There a Place for Dietary Fiber Supplements in Weight Management?
Inadequate dietary fiber intake is common in modern diets, especially in children. Epidemiological and experimental evidence point to a significant association between a lack of fiber intake and ischemic heart disease, stroke atherosclerosis, type 2 diabetes, overweight and obesity, insulin resistance, hypertension, dyslipidemia, as well as gastrointestinal disorders such as diverticulosis, irritable bowel disease, colon cancer, and cholelithiasis. The physiological effects of fiber relate to the physical properties of volume, viscosity, and water-holding capacity that the fiber imparts to food leading to important influences over the energy density of food. Beyond these physical properties, fiber directly impacts a complex array of microbiological, biochemical, and neurohormonal effects directly through modification of the kinetics of digestion and through its metabolism into constituents such as short chain fatty acids, which are both energy substrates and important enteroendocrine ligands. Of particular interest to clinicians is the important role dietary fiber plays in glucoregulation, appetite, and satiety. Supplementation of the diet with highly functional fibers may prove to play an important role in long-term obesity management
Дослідження впливу відпалу на питомий опір аморфних сплавів на основі алюмінію
In this study, electrical properties of Al-Y-Ni alloys produced by melt-spinning method were investigated. Before annealing, XRD analyzes were performed and the samples were found to be amorphous. Exothermic peaks were observed in DSC measurements and crystallization stages of the alloys were determined. Al85Y11Ni4, Al85Y10Ni5 and Al85Y5Ni10 samples were annealed at some temperature and their electrical resistivity was measured by four-point method. The large decrease in resistivity was observed during crystallization between 200 - 400 ˚C. These results were consistent with XRD and DSC measurements.У статті досліджено електричні властивості сплавів Al-Y-Ni, отриманих методом з розплаву. Перед відпалюванням проведено XRD-аналіз та виявлено аморфність зразків. При DSC-вимірюваннях спостерігалися екзотермічні піки та визначено стадії кристалізації сплавів. Зразки Al85Y11Ni4, Al85Y10Ni5 та Al85Y5Ni10відпалювали при певній температурі, а їх електричний опір вимірювали чотиризондовим методом. Під час кристалізації в інтервалі (200 - 400) °C спостерігається суттєве пониження питомого опору. Ці результати відповідали даним, отриманим із вимірюваннь XRD та DSC
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Regulation of the clock gene expression in human adipose tissue by weight loss.
BACKGROUND: The circadian clock coordinates numerous metabolic processes to adapt physiological responses to light-dark and feeding regimens and is itself regulated by metabolic cues. The implication of the circadian clock in the regulation of energy balance and body weight is widely studied in rodents but not in humans. Here we investigated (1) whether the expression of clock genes in human adipose tissue is changed by weight loss and (2) whether these alterations are associated with metabolic parameters. SUBJECTS/METHODS: Subcutaneous adipose tissue (SAT) samples were collected before and after 8 weeks of weight loss on an 800 kcal per day hypocaloric diet (plus 200 g per day vegetables) at the same time of the day. Fifty overweight subjects who lost at least 8% weight after 8 weeks were selected for the study. The expression of 10 clock genes and key metabolic and inflammatory genes in adipose tissue was determined by quantitative real-time PCR. RESULTS: The expression of core clock genes PER2 and NR1D1 was increased after the weight loss. Correlations of PERIOD expression with body mass index (BMI) and serum total, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol levels and of NR1D1 expression with total and LDL cholesterol were found that became non-significant after correction for multiple testing. Clock gene expression levels and their weight loss-induced changes tightly correlated with each other and with genes involved in fat metabolism (FASN, CPT1A, LPL, PPARG, PGC1A, ADIPOQ), energy metabolism (SIRT1), autophagy (LC3A, LC3B) and inflammatory response (NFKB1, NFKBIA, NLRP3, EMR1). CONCLUSION: Clock gene expression in human SAT is regulated by body weight changes and associated with BMI, serum cholesterol levels and the expression of metabolic and inflammatory genes. Our data confirm the tight crosstalk between molecular clock and metabolic and inflammatory pathways involved in adapting adipose tissue metabolism to changes of the energy intake in humans
Insulin directly regulates the circadian clock in adipose tissue
Adipose tissue (AT) is a key metabolic organ which functions are rhythmically regulated by an endogenous circadian clock. Feeding is a zeitgeber aligning the clock in AT with the external time but mechanisms of this regulation remain largely unclear. We tested the hypothesis that postprandial changes of the hormone insulin directly entrain circadian clocks in AT and investigated transcriptional-dependent mechanism of this regulation. We analysed gene expression in subcutaneous AT (SAT) of obese subjects collected before and after the hyperinsulinemic-euglycemic clamp (EC) or control saline infusion (SC). The expression of core clock gene PER2, PER3 and NR1D1 in SAT were differentially changed upon insulin and saline infusion suggesting insulin-dependent clock regulation. In human stem cell-derived adipocytes, mouse 3T3-L1 cells and AT explants from mPer2Luc knockin mice, insulin induced a transient increase of the Per2 mRNA and protein expression leading to the phase shift of circadian oscillations and showing similar effects for Per1. Insulin effects were dependent on the region between the -64 and -43 in the Per2 promoter, but not on CRE and E-box elements. Our results demonstrate that insulin directly regulates circadian clocks in AT and isolated adipocytes and thus represent a primary mechanism of feeding-induced AT clock entrainment
Effects of weight loss and long-term weight maintenance with diets varying in protein and glycemic index on cardiovascular risk factors: the diet, obesity, and genes (DiOGenes) study: a randomized, controlled trial.
BACKGROUND: We sought to separately examine the effects of either weight loss or diets varying in protein content and glycemic index without further changes in body weight on cardiovascular risk factors within the Diet, Obesity, and Genes study (DiOGenes). METHODS AND RESULTS: DiOGenes is a pan-European controlled dietary intervention study in 932 overweight adults who first lost body weight on an 8-week low-calorie diet and were then randomized to 1 of 5 ad libitum diets for 26 weeks. The diets were either high or low protein or high or low glycemic index in 4 combinations or control. Weight loss (-11.23 kg; 95% confidence interval, -11.54 to -10.92; P<0.001) reduced high-sensitivity C-reactive protein (-1.15 mg/L; 95% confidence interval, -1.30 to -0.41; P<0.001), low- and high-density lipoprotein cholesterol, triglycerides, and blood pressure. During the 26-week weight maintenance period in the intention-to-treat analysis, the further decrease of high-sensitivity C-reactive protein blood levels was -0.46 mg/L greater (95% confidence interval, -0.79 to -0.13) in the groups assigned to low-glycemic-index diets than in those on high-glycemic-index diets (P<0.001). Groups on low-protein diets achieved a -0.25 mg/L greater reduction in high-sensitivity C-reactive protein (95% confidence interval, -0.59 to -0.17) than those on high-protein diets (P<0.001), whereas lipid profiles and blood pressure were not differently affected. CONCLUSIONS: This large-scale intervention study clearly separates weight loss from dietary composition-related effects. Low-glycemic-index carbohydrates and, to a lesser extent, low-protein intake may specifically reduce low-grade inflammation and associated comorbidities in overweight/obese adults. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT00390637
Effects of weight loss and long-term weight maintenance with diets varying in protein and glycemic index on cardiovascular risk factors: the diet, obesity, and genes (DiOGenes) study: a randomized, controlled trial
BACKGROUND:
We sought to separately examine the effects of either weight loss or diets varying in protein content and glycemic index without further changes in body weight on cardiovascular risk factors within the Diet, Obesity, and Genes study (DiOGenes).
METHODS AND RESULTS:
DiOGenes is a pan-European controlled dietary intervention study in 932 overweight adults who first lost body weight on an 8-week low-calorie diet and were then randomized to 1 of 5 ad libitum diets for 26 weeks. The diets were either high or low protein or high or low glycemic index in 4 combinations or control. Weight loss (-11.23 kg; 95% confidence interval, -11.54 to -10.92; P<0.001) reduced high-sensitivity C-reactive protein (-1.15 mg/L; 95% confidence interval, -1.30 to -0.41; P<0.001), low- and high-density lipoprotein cholesterol, triglycerides, and blood pressure. During the 26-week weight maintenance period in the intention-to-treat analysis, the further decrease of high-sensitivity C-reactive protein blood levels was -0.46 mg/L greater (95% confidence interval, -0.79 to -0.13) in the groups assigned to low-glycemic-index diets than in those on high-glycemic-index diets (P<0.001). Groups on low-protein diets achieved a -0.25 mg/L greater reduction in high-sensitivity C-reactive protein (95% confidence interval, -0.59 to -0.17) than those on high-protein diets (P<0.001), whereas lipid profiles and blood pressure were not differently affected.
CONCLUSIONS:
This large-scale intervention study clearly separates weight loss from dietary composition-related effects. Low-glycemic-index carbohydrates and, to a lesser extent, low-protein intake may specifically reduce low-grade inflammation and associated comorbidities in overweight/obese adults