•More Fe2+ leads to better planktonic and sessile Desulfovibrio vulgaris growth.•More Fe2+ increases dissolved H2S concentration despite increased FeS precipitation.•More Fe2+ in the culture medium ...increases carbon steel weight loss and pit depth.•With more Fe2+, increased corrosion is primarily attributed to more sessile cells.•Electrochemical measurements corroborate weight loss and pit depth data.
Ferrous ion (Fe2+) in a sulfate reducing bacteria (SRB) culture medium is known to enhance microbiologically influenced corrosion (MIC) of carbon steel, but the underlining mechanism is controversial. This work showed that it was due to better sessile cell growth that was likely attributed to Fe2+ detoxification of H2S. Two hundred ppm (w/w) initial Fe2+ in the ATCC 1249 medium achieved a 4.7 times higher Desulfovibrio vulgaris sessile cell count and 5.0 times higher C1018 carbon steel weight loss, compared to 20 ppm. Linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic polarization measurements corroborated weight loss and pitting data trends.
Using metabolomics technique to analyze the response to a dietary intervention generates valuable information concerning the effects of the prescribed diet on metabolic regulation. To determine ...whether low calorie diet (LCD)-induced weight reduction causes changes in plasma metabolites and metabolic characteristics.
Overweight subjects consumed a LCD (n = 47) or a weight maintenance diet (control, n = 50) in a randomized, controlled design study with a 12-week clinical intervention period. Plasma samples were analyzed using an UPLC-LTQ-Orbitrap MS.
The 12-week LCD intervention resulted in significant mild weight loss, with an 8.3% and 10.6% reduction observed in the visceral fat area (VFA) at the level of the lumbar vertebrae L1 and L4, respectively. The LCD group showed a significant increase in the mean change of serum free fatty acids compared to the control group. In the LCD group, we observed a significant increase in the acylcarnitine (AC) levels, including hexanoylcarnitine, L-octanoylcarnitine, 9-decenoylcarnitine, trans-2-dodecenoylcanitine, dodecanoylcarnitine, 3,5-tetradecadiencarnitine, cis-5-tetradecenoylcarnitine, 9,12-hexadecadienoylcarnitine, and 9-hexadecenoylcarnitne at the 12-week follow-up assessment. When the plasma metabolite changes from baseline were compared between the control and LCD groups, the LCD group showed significant increases in hexanoylcarnitine, L-octanoylcarnitine, trans-2-dodecenoylcanitine, and 3,5-tetradecadiencarnitine than the control group. Additionally, the changes in these ACs in the LCD group strongly negatively correlated with the changes in the VFA at L1 and/or L4.
Mild weight loss from 12-week calorie restriction increased the plasma levels of medium- and long-chain ACs. These changes were coupled with a decrease in VFA and an increase in free fatty acids.
NCT03135132 ; April 26, 2017.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change ...following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months.
Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study.
All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants.
RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.
One of the major challenges in obesity treatment is to explain the high variability in the individual's response to specific dietary and physical activity interventions. With this study, we tested ...the hypothesis that specific DNA methylation changes reflect individual responsiveness to lifestyle intervention and may serve as epigenetic predictors for a successful weight-loss.
We conducted an explorative genome-wide DNA methylation analysis in blood samples from 120 subjects (90% men, mean ± SD age = 49 ± 9 years, body mass-index (BMI) = 30.2 ± 3.3 kg/m
) from the 18-month CENTRAL randomized controlled trial who underwent either Mediterranean/low-carbohydrate or low-fat diet with or without physical activity.
Analyses comparing male subjects with the most prominent body weight-loss (responders, mean weight change - 16%) vs. non-responders (+ 2.4%) (N = 10 each) revealed significant variation in DNA methylation of several genes including LRRC27, CRISP2, and SLFN12 (all adj. P < 1 × 10
). Gene ontology analysis indicated that biological processes such as cell adhesion and molecular functions such as calcium ion binding could have an important role in determining the success of interventional therapies in obesity. Epigenome-wide association for relative weight-loss (%) identified 15 CpGs being negatively correlated with weight change after intervention (all combined P < 1 × 10
) including new and also known obesity candidates such as NUDT3 and NCOR2. A baseline DNA methylation score better predicted successful weight-loss area under the curve (AUC) receiver operating characteristic (ROC) = 0.95-1.0 than predictors such as age and BMI (AUC ROC = 0.56).
Body weight-loss following 18-month lifestyle intervention is associated with specific methylation signatures. Moreover, methylation differences in the identified genes could serve as prognostic biomarkers to predict a successful weight-loss therapy and thus contribute to advances in patient-tailored obesity treatment.
Female university students are at risk for weight gain and use of inappropriate weight-loss strategies. By gaining a greater understanding of the weight-loss strategies used by and weight management ...related characteristics of these students, effective weight management interventions for this vulnerable group can be developed.
Two hundred and fifty female students from South Africa universities, aged 18-25 years, participated in this cross-sectional study; 162 attempted weight loss during the year preceding the study (dieters) and 88 were non-dieters. Weight and height were measured and BMI (kg/m(2)) computed. A self-administered questionnaire was used to record all other variables. Weight loss strategies were described for dieters and compared between BMI groups within the dieters group. Weight management related characteristics were compared between dieters and non-dieters. Statistical tests included Pearson Chi-square test, independent samples t-test or Mann-Whitney U test (depending on distribution of the data). Predictors for a higher BMI and being overweight/obese (BMI ≥25 kg/m(2)) were identified using regression models.
Healthy weight-loss strategies included increased exercise and fruit/vegetable intake and decreased intake of sugar and fat containing items; unhealthy methods included eating little food and skipping meals; and extreme weight loss strategies included laxatives and vomiting. The most commonly used weight-loss product was Herbex. Dieters were characterized by a higher BMI, overestimation of their weight (especially normal weight students), dissatisfaction with weight and select body parts, higher intake of breakfast and healthy foods, lower intake of unhealthy foods, higher levels of vigorous physical activity, higher use of select informal weight-loss information sources and experiencing more pressure to lose weight from mothers, siblings and friends. Predictors of higher BMI and/or increased risk for BMI ≥25 included weight-loss attempt during the past year, race, dissatisfaction with waist, perception of currently being "chubby," and higher frequencies of intake of a snack and fatty foods.
Attempting weight-loss is common among female students and predicts BMI. Healthy (mainly), unhealthy and extreme weight loss methods are used. Dieters are characterized by a less realistic body image, lower body satisfaction, higher pressure to lose weight, use of informal weight-management information and a healthier life-style.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Reactivity of in-situ chars was investigated by rapid heating TGA and heating stage microscope.•The combined index by Raman and XRD is established for char gasification reactivity at the rapid ...heating rate.•The gasification rate of in-situ chars in HTSM was higher than that in rapid heating TGA.
The coal pyrolysis and char gasification process have been widely studied in TGA at a low heating rate, which is far lower than the heating rate when coal particle enters into the boiler and gasifier. In this work, the isothermal CO2 gasification reactivity of in-situ coal chars was performed in rapid heating TGA and a heating stage microscope. The char structure parameters determined by XRD and Raman were combined to describe the char reactivity at the same temperature. Results showed that maximum weight loss rate (DTGmax) of raw coal evidently increased and the corresponding maximum rate temperature raised with the increasing of heating rate during pyrolysis. Nonetheless, the heating rate had slightly effect on gasification reactivity of in-situ char samples when it exceeded 50 K/min. Considering the physical meaning and universality of the coal char structure and gasification reactivity fitting, the XRD and Raman structural parameters were combined to describe the gasification reactivity. The new method for coal char reactivity under rapid heating rate is established, Rs=0.174+43.14d002,aLc,a+3.58ID3×ID4IG2. Furthermore, a visually heating stage microscope was also applied for determining the in-situ char reactivity through image analyzing. The gasification process of in-situ coal char particles fits the shrinking particle pattern at the original and midterm stages. However, the shrinking particle pattern changed into the shrinking core pattern at high carbon conversion. Moreover, the CO inhibition effect and inter-particle interaction account for the difference of gasification reactivity by rapid heating TGA and heating stage microscope.
A high dietary protein (P) content and low glycemic index (LGI) have been suggested to be beneficial for weight management, but long-term studies are scarce.
The DIOGENES randomized clinical trial ...investigated the effect of P and GI on weight loss maintenance in overweight or obese adults in eight centers across Europe. This study reports the 1-year results in two of the centers that extended the intervention to 1 year.
After an 8-week low-calorie diet (LCD), 256 adults (body mass index >27 kg m(-)(2)) were randomized to five ad libitum diets for 12 months: high P/LGI (HP/LGI), HP/high GI (HP/HGI), low P/LGI (LP/LGI), LP/HGI and a control diet. During the first 6 months, foods were provided for free through a shop system and during the whole 12-month period, subjects received guidance by a dietician. Primary outcome variable was the change in body weight over the 12-month intervention period.
During the LCD period, subjects lost 11.2 (10.8, 12.0) kg (mean (95% confidence interval (CI))). Average weight regain over the 12-month intervention period was 3.9 (95% CI 3.0-4.8) kg. Subjects on the HP diets regained less weight than subjects on the LP diets. The difference in weight regain after 1 year was 2.0 (0.4, 3.6) kg (P=0.017) (completers analysis, N=139) or 2.8 (1.4, 4.1) kg (P<0.001) (intention-to-treat analysis, N=256). No consistent effect of GI on weight regain was found. There were no clinically relevant differences in changes in cardiometabolic risk factors among diet groups.
A higher protein content of an ad libitum diet improves weight loss maintenance in overweight and obese adults over 12 months.
Online weight-loss communities (OWCs) provide individuals with various tools to support their weight management, such as weight recorders and weight-loss journals. These tools enable individuals to ...focus on different aspects of their self-regulation, including weight-loss outcomes and behavioral routines. Prior research, however, has not fully incorporated individuals’ self-regulation focuses; thus, there is limited understanding of individuals’ online weight-management dynamics as well as the operating mechanisms of OWCs. This gap in the literature motivates us to develop a framework that is able to account for individuals’ multiple self-regulation focuses, termed
self-regulatory dimensions
in this study. We propose a multidimensional, continuous-time hidden Markov model, which can not only capture individuals’ self-regulatory dimensions jointly as a multidimensional vector, but also can incorporate a hidden layer of dynamics that depicts individuals’ cognitive states in producing weight-management behaviors. By investigating a leading noncommercial OWC in the United States, we find that individuals tend to increase their journal-recording behaviors while decreasing self-weighing behaviors after they have participated in online social activities. Given that individuals usually expend limited effort toward weight management, this result suggests that individuals may shift their focus from weight-loss outcomes (i.e., changes in weight) to weight-management behavioral routines. Therefore, neglecting either self-regulatory dimension would result in an underestimation of individuals’ engagement in conducting self-management in OWCs. Our results also provide insight into social influence on individuals’ weight-management behaviors. This study contributes to the extant literature on individuals’ engagement in online healthcare communities and the functionality of OWCs.
This paper was accepted by Anandhi Bharadwaj, information systems.
Abstract
Background/Objectives
Obesity is the main risk factor for obstructive sleep apnoea, commonly occurring in females who are overweight after menopause. We aimed to study the effect of a ...palaeolithic diet on sleep apnoea in females with overweight after menopause from the population.
Methods
Seventy healthy, non-smoking females with a mean age of 60 years and a mean BMI of 33 kg/m
2
were randomised to a palaeolithic diet or to a control low-fat diet according to Nordic Nutritional Recommendations, for 2 years. The apnoea-hypopnoea index was measured and daytime sleepiness was estimated during the intervention.
Results
The mean apnoea-hypopnoea index at baseline was 11.6 (95% CI 8.6–14.5). The mean weight loss was 7.2 kg (95% CI 5.3–9.2 kg) in the palaeolithic diet group and 3.9 kg in the control group (95% CI 1.9–5.9 kg);
p
< 0.021 for the group difference. The reduction in weight corresponded to a reduction in the apnoea-hypopnoea index in the palaeolithic diet group (
r
= 0.38,
p
= 0.034) but not in the control group (
r
= 0.08,
p
= 0.69). The apnoea-hypopnoea index was reduced in the palaeolithic diet group when the weight was reduced by more than 8 kg. Daytime sleepiness according to the Epworth Sleepiness Scale score and the Karolinska Sleepiness Scale score was unaffected by dietary group allocation.
Conclusions
A substantial decrease in body weight of 8 kg was needed to achieve a reduction in sleep apnoea in this small trial of women who are overweight after menopause. The palaeolithic diet was more effective for weight reduction than a control low-fat diet and the reduction in sleep apnoea was related to the degree of weight decrement within this diet group.
Trial registration
Clinicaltrials.gov: NCT00692536.
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