Maximum Weight Change Research Articles

Effect of La2O3 content on the oxygen barrier ability of the HfB2‐SiC coating at 1973 K

AbstractTo inhibit the destructive evolution of the HfB2‐SiC coating during oxidation, La2O3 was added to modify the oxygen‐blocking capability of the HfB2‐SiC coating. The effect of La2O3 content on the oxygen barrier capacity of HfB2‐SiC was investigated. The addition of 5 vol.% La2O3 lowered the oxidation activity and strengthened the inert oxygen barrier capacity of the HfB2‐SiC coating, which made the oxygen permeability and maximum weight change rate of the coating decrease by 30.32% and 73.97%, respectively. Due to the solid solution reaction of the dispersed La2O3, HfO2, and SiO2 nanoparticles, a stable Hf‐B‐La‐Si‐O multiphase glass was formed on the surface of the coating. Besides, the high‐melting‐point particles, such as HfO2, La2Hf2O7, and HfSiO4, dispersed in the glass layer as hard particles and formed a mosaic structure based on the Hf‐B‐La‐Si‐O compound, which increased the cumulative protection efficiency of the HfB2‐SiC coating to 98.5% and reduced the inert factor value by 84.57%. However, the excessive consumption of SiO2 glass by La2O3 results in dendritization of the generated glass when the La2O3 content is above 10 vol.%, which reduced the self‐healing capability of the generated glass and instead weakened the oxygen barrier properties of the HfB2‐SiC‐La2O3 coatings.

Oxidation and phase transformation behaviors of Si3N4-xMgAl2O4 (0

This research investigates the oxidation behavior of nanocrystalline/amorphous Si3N4 compounds in atmospheres with different oxygen pressures. High purity nanocrystalline/amorphous Si3N4 and MgAl2O4 mixtures were used to investigate oxidation behavior of Si3N4. Si3N4-xMgAl2O4 (0 < x < 90 wt.%) samples were prepared with mixing in a jar mill, followed by pressing and heating in a high vacuum furnace. Specimens were characterized using FE-SEM, EDS, XRD, FT-IR, and ICP. Thermal analysis (TG/DSC) was also employed to investigate the thermal behavior of samples in different atmospheres. Results showed that phase transformation in pure Si3N4 is controlled by holding time and oxygen pressure in the atmosphere. Results also showed an increase in the weight of pure Si3N4 by 5.3 and 15.2 % for 0.5 and 2 h in a vacuum atmosphere, respectively, inferring that crystallization reaction proceeds with holding time. In the temperature range 1000–1400 °C, a noticeable exothermic peak has appeared for pure Si3N4 in the air atmosphere which was attributed to the formation of cristobalite (SiO2) phase. Besides, thermal analyses of Si3N4-xMgAl2O4 (0 < x < 90 wt.%) samples in the nitrogen atmosphere showed that the maximum weight change was attained in the Si3N4-50% MgAl2O4 sample. Mechanisms and implications of oxidation in all cases are thoroughly discussed.

Sorption and Degradation Behaviour of Epoxy Composites Reinforced with Amine-Coated Polyester Triangular Bars in Acid Environment

Sorption and degradation characteristics of epoxy composites reinforced with amine-coated polyester triangular bars in acid environment were studied. The following aspects of amine-coated triangular bars were varied during preparation of epoxy composites: orientation (flat or pointed), alignment (parallel or staggered), spacing (1 or 5 mm), and size (5 or 7 mm). Composites were tested using a one-side acid exposure test in 5 wt% hydrochloric (HCl) acid solution at 40°C for 308 h. Weight change curves of composites with pointed orientation show continuous sorption of acid solution with square root of time, while composites with flat orientation display an initial increase in weight followed by continuous weight loss. This can be attributed to the large interfacial area of triangular bars exposed to diffusing acid in flat orientation. Since the bars are amine-coated, the acid preferentially diffuses in the interfacial region, resulting to early degradation of composite. The following parameters were measured from the weight curves for data analysis: initial sorption rate (% - h-0.5), maximum weight change during sorption (%), and weight loss due to degradation (%). Analysis of variance (ANOVA) shows maximum weight change and weight loss due to degradation of epoxy composites are significantly affected by orientation and spacing.

Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome: a SYSDIET sub-study.

BackgroundDiet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism-related genes in peripheral blood mononuclear cells (PBMCs) during a 2-h oral glucose tolerance test (OGTT) in individuals with MetS.MethodsA Nordic multicenter randomized dietary study included subjects (n = 213) with MetS, randomized to a ND group or a control diet (CD) group applying an isocaloric study protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L−1, and baseline body mass index <39 kg m−2. PBMCs were isolated, and the mRNA gene expression analysis was measured by quantitative real-time polymerase chain reaction (qPCR). We analyzed the mRNA expression changes of 44 genes before and after a 2hOGTT at the beginning and the end of the intervention.ResultsThe healthy ND significantly down-regulated the expression of toll-like receptor 4 (TLR4), interleukin 18 (IL18), and thrombospondin receptor (CD36) mRNA transcripts and significantly up-regulated the expression of peroxisome proliferator-activated receptor delta (PPARD) mRNA transcript after the 2hOGTT compared to the CD.ConclusionsA healthy ND is able to modify the gene expression in PBMCs after a 2hOGTT. However, more studies are needed to clarify the biological and clinical relevance of these findings.Electronic supplementary materialThe online version of this article (doi:10.1186/s12263-016-0521-4) contains supplementary material, which is available to authorized users.

Patterns and Predictors of Weight Loss After Gastrectomy for Cancer.

Weight loss following gastrectomy for patients with gastric cancer has not been well characterized. We assessed the impact of patient and procedure-specific variables on postoperative weight loss following gastrectomy for cancer. A prospectively maintained gastric cancer database identified patients undergoing gastrectomy for cancer. Clinical and pathologic characteristics, baseline body mass index (BMI), and postoperative weights were extracted. Change in weight was analyzed by percent change in weight and absolute change in BMI. Random coefficients models were used to test whether the rate of change in weight over time differed by factors of interest. Of 376 consecutive patients who underwent resection for gastric adenocarcinoma, 55% were male, median age 66years, and mean preoperative BMI 27.1 (range 16.2-45.6). Total gastrectomy was associated with more weight loss than subtotal gastrectomy at 1year (15 vs. 6%, early stage; 17 vs. 7%, late stage). Maximum weight change was observed at 6-12months after operation and remained stable or improved at 2years. For early- and late-stage patients, median percent weight loss at 1year was greater for BMI≥30 versus BMI<30 (14 vs. 8%, early stage; 15 vs. 9%, late stage). The extent of weight loss after gastrectomy for gastric cancer is dependent on preoperative BMI and extent of gastric resection. Maximum weight change is expected by 12months after operation and will stabilize or improve over time.

Acute kidney injury is associated with bronchopulmonary dysplasia/mortality in premature infants.

Acute kidney injury (AKI) impairs electrolyte balance, alters fluid homeostasis and decreases toxin excretion. More recent data suggest it also affects the physiology of distant organs. We performed a prospective cohort study which invloved 122 premature infants [birth weight (BW) ≤1200 g and/or gestational age (GA) <31 weeks] to determine relationships between AKI and bronchopulmonary dysplasia (BPD)/mortality. Days until oxygen discontinuation was compared between those with and without AKI in survivors who received oxygen for ≥24 h. Acute kidney disease, defined by a rise in serum creatinine (SCr) of ≥0.3 mg/dl or an increase in SCr of ≥150%, occurred in 36/122 (30%) of the premature infants. Those with AKI had a 70% higher risk of oxygen requirement or of dying at 28 days of life [relative risk (RR) 1.71, 95% confidence interval (CI) 1.22-2.39; p < 0.002]. This association remained after controlling for GA, pre-eclampsia, 5 min Apgar score and percentage maximum weight change (max % weight Δ) in the first 4 days (RR 1.45, 95% CI 1.07-1.97); p < 0.02). Similar findings were noted for receipt of mechanical ventilation/death by day 28 (adjusted RR 1.53, 95% CI 1.05-2.22; p < 0.03). Those without AKI were 2.5-fold more likely to come off oxygen [hazard ratio (HR) 1.3-5; p < 0.02) than those with AKI, even when controlling for GA, pre-eclampsia, 5 min Apgar and max % weight Δ (multivariate HR 2.0, 95% CI 0.9-4.0; p < 0.06). In premature infants, AKI is associated with BPD/mortality. As AKI could lead to altered lung physiology, interventions to ameliorate AKI could improve long-term BPD.

Healthy Nordic diet downregulates the expression of genes involved in inflammation in subcutaneous adipose tissue in individuals with features of the metabolic syndrome

Previously, a healthy Nordic diet (ND) has been shown to have beneficial health effects close to those of Mediterranean diets. The objective was to explore whether the ND has an impact on gene expression in abdominal subcutaneous adipose tissue (SAT) and whether changes in gene expression are associated with clinical and biochemical effects. Obese adults with features of the metabolic syndrome underwent an 18- to 24-wk randomized intervention study comparing the ND with the control diet (CD) (the SYSDIET study, carried out within Nordic Centre of Excellence of the Systems Biology in Controlled Dietary Interventions and Cohort Studies). The present study included participants from 3 Nordic SYSDIET centers [Kuopio (n = 20), Lund (n = 18), and Oulu (n = 18)] with a maximum weight change of ±4 kg, highly sensitive C-reactive protein concentration <10 mg/L at the beginning and the end of the intervention, and baseline body mass index (in kg/m²) <38. SAT biopsy specimens were obtained before and after the intervention and subjected to global transcriptome analysis with Gene 1.1 ST Arrays (Affymetrix). Altogether, 128 genes were differentially expressed in SAT between the ND and CD (nominal P < 0.01; false discovery rate, 25%). These genes were overrepresented in pathways related to immune response (adjusted P = 0.0076), resulting mainly from slightly decreased expression in the ND and increased expression in the CD. Immune-related pathways included leukocyte trafficking and macrophage recruitment (e.g., interferon regulatory factor 1, CD97), adaptive immune response (interleukin32, interleukin 6 receptor), and reactive oxygen species (neutrophil cytosolic factor 1). Interestingly, the regulatory region of the 128 genes was overrepresented for binding sites for the nuclear transcription factor κB. A healthy Nordic diet reduces inflammatory gene expression in SAT compared with a control diet independently of body weight change in individuals with features of the metabolic syndrome.

Weight Change and Health Outcomes at 3 Years After Bariatric Surgery Among Individuals With Severe Obesity

Severe obesity (body mass index [BMI] ≥35) is associated with a broad range of health risks. Bariatric surgery induces weight loss and short-term health improvements, but little is known about long-term outcomes of these operations. To report 3-year change in weight and select health parameters after common bariatric surgical procedures. The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. PARTICIPANTS AND EXPOSURE: Adults undergoing first-time bariatric surgical procedures as part of routine clinical care by participating surgeons were recruited between 2006 and 2009 and followed up until September 2012. Participants completed research assessments prior to surgery and 6 months, 12 months, and then annually after surgery. Three years after Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB), we assessed percent weight change from baseline and the percentage of participants with diabetes achieving hemoglobin A1c levels less than 6.5% or fasting plasma glucose values less than 126 mg/dL without pharmacologic therapy. Dyslipidemia and hypertension resolution at 3 years was also assessed. At baseline, participants (N = 2458) were 18 to 78 years old, 79% were women, median BMI was 45.9 (IQR, 41.7-51.5), and median weight was 129 kg (IQR, 115-147). For their first bariatric surgical procedure, 1738 participants underwent RYGB, 610 LAGB, and 110 other procedures. At baseline, 774 (33%) had diabetes, 1252 (63%) dyslipidemia, and 1601 (68%) hypertension. Three years after surgery, median actual weight loss for RYGB participants was 41 kg (IQR, 31-52), corresponding to a percentage of baseline weight lost of 31.5% (IQR, 24.6%-38.4%). For LAGB participants, actual weight loss was 20 kg (IQR, 10-29), corresponding to 15.9% (IQR, 7.9%-23.0%). The majority of weight loss was evident 1 year after surgery for both procedures. Five distinct weight change trajectory groups were identified for each procedure. Among participants who had diabetes at baseline, 216 RYGB participants (67.5%) and 28 LAGB participants (28.6%) experienced partial remission at 3 years. The incidence of diabetes was 0.9% after RYGB and 3.2% after LAGB. Dyslipidemia resolved in 237 RYGB participants (61.9%) and 39 LAGB participants (27.1%); remission of hypertension occurred in 269 RYGB participants (38.2%) and 43 LAGB participants (17.4%). Among participants with severe obesity, there was substantial weight loss 3 years after bariatric surgery, with the majority experiencing maximum weight change during the first year. However, there was variability in the amount and trajectories of weight loss and in diabetes, blood pressure, and lipid outcomes. clinicaltrials.gov Identifier: NCT00465829.

Assessment of maximum weight change and duration of therapeutic effect for non-surgical treatment of obesity using an exponential model.

Efficacy of weight loss and maintenance therapies in obesity is difficult to quantify due to continuous weight changes over time. We assessed a single exponential model of weight changes during selected non-surgical therapies of non-diabetic obese subjects. We analyzed published mean weight data from 6 studies of ≥12 weeks duration, with comparable treatment groups, and ≥4 weight measurements during very low carbohydrate or fat diets, or treatment with Lorcaserin, Sibutramine or Orlistat. We fit data to a single exponential model to estimate maximum predicted weight loss or regain and duration of weight loss or regain for each therapy. A single exponential is the appropriate model as determined by Kolmogorov-Smirnov, constant variance, and Durbin-Watson tests. Validity of parameter estimates was indicated by coefficients of variation <25%. Sensitivity analysis showed that weight regain at the end of the weight loss phase affected parameter estimates in some instances, with variations of weight loss of 0.2-0.7% of basal. Estimated weight loss and regain were similar to observed weight changes in all studies. The model could also be used to assess dose-response relationships. Estimates from the model were used to compare concurrent obesity regimens using 95% confidence intervals, taking into account pre-determined minimal clinically important differences. This exponential model may provide accurate estimates of maximum achievable weight loss or regain and optimal duration of efficacy for a variety of non-surgical weight loss and maintenance regimens from published mean weight data and may be useful to more accurately evaluate weight loss and maintenance regimens.

Obesity: Implementation of a Weight Management Pharmaceutical Care Service

Obesity, a national epidemic, is one of the leading causes of preventable morbidity and mortality in the US. Pharmacists can play an integral role in weight management. Offering weight management services provides an opportunity to increase public awareness of pharmaceutical care and attract patients to pharmacy programs. To describe the implementation and evaluate outcomes of a weight management pharmaceutical care service in a stand alone pharmaceutical care center on a college campus. A retrospective review of data was conducted on 289 patient charts to evaluate the change in weight, body mass index (BMI), percent body fat, and weight-related health conditions in patients who participated in the Healthy Habits program. The net change (change in values observed from first to last appointment) in weight was a loss of 1021.8 kg. The maximum weight change (change seen from the first appointment to the lowest value obtained during the program) was a loss of 1530.5 kg. These values correspond to a net mean weight loss of 3.6 kg per patient (10% of baseline weight) and a maximum mean weight loss per patient of 5.5 kg (15% of baseline weight). Eighty-three patients were able to decrease their BMI category and 76 patients had a decrease in risk status from baseline. The Auburn University Pharmaceutical Care Center's Healthy Habits program has been successful in helping patients decrease total body weight, BMI, and risk of weight-related complications. In addition, the program has increased the opportunity to identify other pharmaceutical care needs of patients and help establish the role of pharmacists in the management of obesity.

Evaluation of vanadium and vanadium-base alloys in hot-trapped sodium

Corrosion tests were conducted with vanadium-base alloys in zirconium-purified sodium from 450° to 750°C for 500 to 4000 hr. The materials tested were vanadium, binary vanadium alloys containing from 10 to 40 wt pct Ti, and two ternary alloys: V-5Ti-15Cr and V-15Ti-7.5Cr. The sodium was analyzed to contain from 1.7 to 8.7 ppm O by the vacuum-distillation technique. The behavior of these materials was determined from weight change data, and from chemical, metallographic, and electron-microprobe analyses of the test specimens. At temperatures up to 650°C, the maximum weight-change varied from a weight loss of 0.45 for vanadium to a weight gain of 0.46 mg per sq dm-day for the V-40Ti alloy. Chemical analyses of the corrosion test specimens indicated that vanadium-base materials were sensitive to the activity of oxygen, carbon, and/or nitrogen in sodium. Alloys containing >10 wt pct Ti increased in oxygen, carbon, and in some tests, nitrogen content, indicating that alloys of this titanium content are not compatible with sodium of the present purity. Complex titanium carbide precipitates were observed near the surface. V-5Ti-15Cr alloy was more resistant to liquid sodium than the other vanadium materials investigated.