Small Weight Changes Research Articles

Clinical risk factors for preterm birth and evaluating maternal psychology in the postpartum period.

Although the specific pathogenesis of preterm birth (PTB) has not been thoroughly clarified, it is known to be related to various factors, such as pregnancy complications, maternal socioeconomic factors, lifestyle habits, reproductive history, environmental and psychological factors, prenatal care, and nutritional status. PTB has serious implications for newborns and families and is associated with high mortality and complications. Therefore, the prediction of PTB risk can facilitate early intervention and reduce its resultant adverse consequences. To analyze the risk factors for PTB to establish a PTB risk prediction model and to assess postpartum anxiety and depression in mothers. A retrospective analysis of 648 consecutive parturients who delivered at Shenzhen Bao'an District Songgang People's Hospital between January 2019 and January 2022 was performed. According to the diagnostic criteria for premature infants, the parturients were divided into a PTB group (n = 60) and a full-term (FT) group (n = 588). Puerperae were assessed by the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS), based on which the mothers with anxiety and depression symptoms were screened for further analysis. The factors affecting PTB were analyzed by univariate analysis, and the related risk factors were identified by logistic regression. According to univariate analysis, the PTB group was older than the FT group, with a smaller weight change and greater proportions of women who underwent artificial insemination and had gestational diabetes mellitus (P < 0.05). In addition, greater proportions of women with reproductive tract infections and greater white blood cell (WBC) counts (P < 0.05), shorter cervical lengths in the second trimester and lower neutrophil percentages (P < 0.001) were detected in the PTB group than in the FT group. The PTB group exhibited higher postpartum SAS and SDS scores than did the FT group (P < 0.0001), with a higher number of mothers experiencing anxiety and depression (P < 0.001). Multivariate logistic regression analysis revealed that a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length in the second trimester, a greater WBC count, and the presence of maternal anxiety and depression were risk factors for PTB (P < 0.01). Moreover, the risk score of the FT group was lower than that of the PTB group, and the area under the curve of the risk score for predicting PTB was greater than 0.9. This study highlights the complex interplay between postpartum anxiety and PTB, where maternal anxiety may be a potential risk factor for PTB, with PTB potentially increasing the incidence of postpartum anxiety in mothers. In addition, a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length, a greater WBC count, and postpartum anxiety and depression were identified as risk factors for PTB.

Quantifying edema in skin tissue in children after cardiac surgery: the QuEST study

ObjectivesTo investigate the validity of a 19-point clinical edema score (CES) and mid-limb circumferences for quantifying edema.MethodsA prospective exploratory study was performed in mechanically ventilated children after cardiac surgery in a tertiary pediatric intensive care unit (PICU). Body weight, a CES, and mid-limb circumferences were performed at baseline and two consecutive 24-h intervals.ResultsWe studied fifty-nine children with a median age of 8.0 days [IQR; 1.0, 14.0]. Body weight and edema measurements were performed at enrolment (baseline) and two subsequent 24-h time points. Between baseline and 24 h, the median change in body weight was −33g [IQR; −146, 106], and between 24 and 48 h, −97g [IQR; −241, −28]. Changes in the CES and leg circumference, but not arm circumference, were significantly associated with small changes in body weight. In a multivariable linear, mixed effects model, accounting for repeated measures within children and baseline values, there was statistically significant evidence that every point increase in CES was associated with an increase of 12.6 g [95%CI; 3.6–21.5] in body weight. Similarly, a 1-cm increase in leg circumference was associated with an increase in body weight of 46.7 g [95%CI; 3.5–89.9]. However, there was no statistically significant association between arm circumference and body weight.ConclusionsIn children after cardiac surgery, a CES and leg circumference, but not arm circumference, may be a valid measure of fluid accumulation. Larger studies in broader populations of critically ill children are warranted.

A randomised controlled trial to investigate the feasibility and acceptability of a small change approach to prevent weight gain

A weight gain prevention strategy showing merit is a small change approach (increase energy expenditure and/or decrease energy intake by 100–200 kcal/day). Studies have tested a small change approach in intensive interventions involving multiple contacts, unsuitable for delivery at scale. The aim here was to assess the feasibility and acceptability of a remote small change weight gain prevention intervention. A randomised controlled trial of 122 participants was conducted. The intervention was a remote 12-week small change weight gain prevention programme (targeting dietary and/or physical activity behaviours). The comparator group received a healthy lifestyle leaflet. Data were collected at baseline and 12-weeks. The primary outcome was the feasibility and acceptability, assessed against three stop–go traffic light criteria: retention, number of participants randomised per month and adherence to a small change approach. Participants’ opinions of a small change approach and weight change were also measured. The traffic light stop–go criteria results were green for recruitment (122 participants recruited in three months) and retention (91%) and red for intervention adherence. Most participants (62%) found a small change approach helpful for weight management and the mean difference in weight was − 1.1 kg (95% CI − 1.7, − 0.4), favouring the intervention group. Excluding intervention adherence, the trial was feasible and acceptable to participants. Despite adherence being lower than expected, participants found a small change approach useful for weight management and gained less weight than comparators. With refinement to increase intervention adherence, progress to an effectiveness trial is warranted.ISRCTN18309466: 12/04/2022 (retrospectively registered).

Quantifying and correcting bias due to outcome dependent self-reported weights in longitudinal study of weight loss interventions

In response to the escalating global obesity crisis and its associated health and financial burdens, this paper presents a novel methodology for analyzing longitudinal weight loss data and assessing the effectiveness of financial incentives. Drawing from the Keep It Off trial—a three-arm randomized controlled study with 189 participants—we examined the potential impact of financial incentives on weight loss maintenance. Given that some participants choose not to weigh themselves because of small weight change or weight gains, which is a common phenomenon in many weight-loss studies, traditional methods, for example, the Generalized Estimating Equations (GEE) method tends to overestimate the effect size due to the assumption that data are missing completely at random. To address this challenge, we proposed a framework which can identify evidence of missing not at random and conduct bias correction using the estimating equation derived from pairwise composite likelihood. By analyzing the Keep It Off data, we found that the data in this trial are most likely characterized by non-random missingness. Notably, we also found that the enrollment time (i.e., duration time) would be positively associated with the weight loss maintenance after adjusting for the baseline participant characteristics (e.g., age, sex). Moreover, the lottery-based intervention was found to be more effective in weight loss maintenance compared with the direct payment intervention, though the difference was non-statistically significant. This framework's significance extends beyond weight loss research, offering a semi-parametric approach to assess missing data mechanisms and robustly explore associations between exposures (e.g., financial incentives) and key outcomes (e.g., weight loss maintenance). In essence, the proposed methodology provides a powerful toolkit for analyzing real-world longitudinal data, particularly in scenarios with data missing not at random, enriching comprehension of intricate dataset dynamics.

Smart microsubmarine shells operated by controlled buoyancy force through metal-ion adsorption/desorption and their biosensor applications

Small and uniform-sized poly(polyethylene glycol (PEG)–co-acrylic acid (AA)) shells engulfing a mineral oil droplet (oil@poly(PEG-co-AA) shells, ∼180 μm) are prepared using the in situ polymerization of the O(mineral oil)–W(PEGDA/AA, PEGDA = polyethylene glycol diacrylate)–O(mineral oil) double emulsion droplets produced in a microfluidic chip. The lightweight oil core and heavy-weight poly(PEG-co-AA) shells exhibit positive buoyancy and negative gravitational forces in water, respectively. Densities of oil@poly(PEG-co-AA) shells were finely tuned in water to be sensitive to a small weight change by controlling microfluidic parameters. The poly(PEG-co-AA) shells are pH-responsive in terms of charged state and shell size. The pH-controlled metal adsorption/desorption at poly(PEG-co-AA) shells breaks the density balance, leading to the sinking or floating of oil@poly(PEG-co-AA) shells in the water. Herein, this levitation and size change of oil@poly(PEG-co-AA) shells are applied to glucose and urea biosensors by immobilizing their enzymes. The divalent (or higher) metal adsorption is distinguishable from monovalent metal adsorption by the diminished size of the oil@poly(PEG-co-AA) shells and their different levitation behavior in water. Thus, these oil@poly(PEG-co-AA) shells facilitate smart motile sensor applications with an unexplored concept, which can be further expanded to other applications such as smart valves in microfluidics and smart windows.

Sulfate resistance of class C/class F fly ash geopolymers

Sulfate attack is one of the significant durability problems for the geopolymer applied for various severe conditions. In this study, the effects of the water-to-fly ash ratio (W/FA), class C fly ash (CF) content, and alkaline content on the setting times and compressive strength of geopolymer pastes were investigated. According to the results, geopolymer samples of three different strength grades (low, medium, and high) were exposed to a 10% magnesium sulfate (MgSO₄) solution at 80 °C. The weight changes, ultrasonic flight-times, and compressive strengths of the specimens were measured to evaluate their sulfate resistances. Control samples were exposed to water at the same temperature. Finally, microstructural analyses using Fourier-transform infrared spectroscopy, X-ray diffraction, and mercury intrusion porosimetry were performed to investigate the corrosion mechanism. The results indicated that higher CF contents led to shorter initial and final setting times and a higher compressive strength regardless of the W/FA and alkaline content. In addition, there was a small weight change for all the geopolymer with different strength grades after they were exposed to an MgSO4 solution. The low strength geopolymer exhibited a better sulfate resistance because of the sustainable increase in the compressive strength and reduction in the ultrasonic flight-time. Moreover, there was a close relationship between the corrosion resistance and the inner structure of the geopolymer mortars. This research provides a theoretical foundation for the application of geopolymers—particularly in coastal and saline areas, which are often subject to sulfate attack.

Association between precarious employment and BMI in the United States.

There is growing recognition that precarious employment is an important determinant of health, which may increase BMI through multiple mechanisms, including stress. It was investigated whether increases in precarious employment were associated with changes in BMI in the United States. Data were from the National Longitudinal Survey of Youth adult cohort (1996-2016) (N=7280). Thirteen indicators were identified to operationalize seven dimensions of precarious employment (range: 0-7, 7 indicating most precarious): material rewards, working-time arrangements, stability, workers' rights, collective organization, interpersonal relationships, and training. The precarious employment-BMI association was estimated using linear regression models and an instrumental variables approach; state- and individual-level firm sizes were the instruments for precarious employment. Models also included individual and year fixed effects and controlled for age, marital status, education, region, and industry. The average precarious employment score (PES) was 3.49 (95% CI: 3.46-3.52). The PES was the highest among Hispanic (4.04; 95% CI: 3.92-4.15) and non-Hispanic Black (4.02; 95% CI: 3.92-4.12) women with lower education. A 1-point increase in the PES was associated with a 2.18-point increase in BMI (95% CI: 0.30-4.01). Given that even small changes in weight affect chronic disease risk, policies to improve employment quality warrant consideration.

Integrating spatially explicit sensitivity and uncertainty analysis in a multi-criteria decision analysis-based groundwater potential zone model

This study presents a spatially explicit sensitivity and uncertainty analysis approach to a GIS-based multi-criteria groundwater potential zone model. The study addressed a deficiency in the way groundwater potential mapping results are typically presented using discrete class outputs without assessment of their certainty with respect to variations in criteria weighting, one of the main contributors to output uncertainty in GIS-based multi-criteria decision analysis studies. We argue, moderating groundwater potential mapping results with localised uncertainty levels will help to refine and prioritise groundwater exploration efforts. The approach also enables a better understanding of the underlying factors influencing uncertainty in model outputs, which can help to inform the calibration of input parameters to improve model performance. Although the procedures presented in this study have been applied to other types of multi-criteria evaluations, its integration in GIS-based groundwater potential modelling has received little attention. We provide a case study focused on a fractured rock environment surrounding the township of Hawker in South Australia where new groundwater resources are sought. Small incremental weight changes were applied one-at-a-time and automated as a task in ArcGIS Pro, built using the ArcPy Python module that interacts with spatial tools allowing geographical analysis. The approach is applicable to both continuous and discrete class-based mapping outputs and enabled a deeper understanding of model output behaviour with respect to criteria weighting alternatives. The case study findings demonstrate the potential value of the approach in mitigating uncertainty and improving confidence in locating sites with high groundwater potential.

Does rearranging meal times at night improve cardiovascular risk factors? An Australian pilot randomised trial in night shift workers

Background and aimsShift workers face an increased risk of cardiovascular disease (CVD), type-2 diabetes and obesity. Eating during the night is a likely contributing factor, as it coincides with the time at which postprandial metabolism is least efficient. In this pilot randomised crossover trial, we examine the effects of a short overnight fast on CVD risk markers (primarily postprandial triglyceride and glucose response) of night shift workers. Methods and resultsNight shift workers with abdominal obesity underwent 4-week intervention and control periods, separated by ≥ 2 weeks washout. In the intervention period, an overnight fast (0100 h–0600 h) was implemented, by redistributing 24-h energy intake. Usual dietary habits were followed in the control period. Outcomes between intervention and control were compared using mixed effects linear regression models.Nineteen adults completed the trial [13 females, mean (±SD) age 41 ± 10 years, BMI 30.7 ± 5.7 kg/m2]. Postprandial triglyceride and glucose response post intervention were not different to post control. The overnight fast was well-tolerated by participants with an adherence rate of 95%, assessed by weekly 24-h dietary recalls. Exploratory analysis indicates lower mean body weight post intervention compared to post control (mean difference: −0.9 kg, 95% CI: −1.3 to −0.4). ConclusionsNight shift workers who habitually ate during their night shifts were able to rearrange their meal times to maintain a small overnight fast, which may have promoted small weight changes. This warrants further investigation into the role of meal timing in mitigating the metabolic consequences of night shift work. Trial registrationAustralian New Zealand Clinical Trials Registry (http://anzctr.org.au/) registered on the 30th May 2017 (ACTRN12617000791336).

A novel approach to increasing community capacity for weight management a volunteer-delivered programme (ActWELL) initiated within breast screening clinics: a randomised controlled trial

BackgroundIt is estimated that around 30% of breast cancers in post-menopausal women are related to lifestyle. The breast cancer-pooling project demonstrated that sustained weight loss of 2 to 4.5 kg is associated with an 18% lower risk of breast cancer, highlighting the importance of small changes in body weight. Our study aimed to assess the effectiveness a volunteer-delivered, community based, weight management programme (ActWELL) for women with a BMI > 25 kg/m2 attending NHS Scotland Breast Screening clinics.MethodsA multicentre, 1:1 parallel group, randomised controlled trial was undertaken in 560 women aged 50 to 70 years with BMI > 25 kg/m2. On completion of baseline measures, all participants received a breast cancer prevention leaflet. Intervention group participants received the ActWELL intervention which focussed on personalised diet advice and pedometer walking plans. The programme was delivered in leisure centres by (the charity) Breast Cancer Now volunteer coaches.Primary outcomes were changes between groups at 12 months in body weight (kg) and physical activity (accelerometer measured step count).ResultsTwo hundred seventy-nine women were allocated to the intervention group and 281 to the comparison group. Twelve-month data were available from 240 (81%) intervention and 227 (85%) comparison group participants. Coaches delivered 523 coaching sessions and 1915 support calls to 279 intervention participants. Mean weight change was − 2.5 kg (95% CI − 3.1 to − 1.9) in the intervention group and − 1.2 kg (− 1.8 to 0.6) in the comparison group. The adjusted mean difference was − 1.3 kg (95% CI − 2.2 to − 0.4, P = 0.003). The odds ratio for losing 5% weight was 2.20 (95% CI 1.4 to 3.4, p = 0.0005) in favour of the intervention. The adjusted mean difference in step counts between groups was 483 steps/day (95% CI − 635 to 1602) (NS).ConclusionsA community weight management intervention initiated at breast screening clinics and delivered by volunteer coaches doubled the likelihood of clinically significant weight loss at 12 months (compared with usual care) offering significant potential to decrease breast cancer risk.Trial registrationDatabase of registration: ISCRTN.Registration number:11057518.Date trial registered:21.07.2017.Date of enrolment of first participant: 01.09.2017.

Additional Assessment of Fecal Corticosterone Metabolites Improves Visual Rating in the Evaluation of Stress Responses of Laboratory Rats

Simple SummaryAssessment of animal welfare is an important aspect of preclinical studies to minimize suffering and burden and to improve scientific data. In a standard preclinical setup, such an assessment is normally done via so-called score sheets, which are part of the official documentation and approval of a preclinical study. These score sheets contain different categories, including objective parameters such as animals’ body weight, as well as more subjective criteria such as general status, behavior, and appearance, by which the animal is assessed and given a score reflecting the burden. However, very little is known about whether this mainly visual-based and subjective evaluation of the animals’ welfare reliably reflects the status of the animal and correlates well with more objective parameters used for assessment of animal welfare. To this end, the current study investigates the concordance of parameters obtained via standardized score sheets and fecal corticosterone metabolites in a preclinical neuroscientific setup. Determination of fecal corticosterone metabolites as response parameter of adrenocortical activity is thereby a well-validated parameter often used to determine animals’ stress levels. Our data reveal that specific but subjective scores did not mirror the stress response assessed via fecal corticosterone metabolites in the same animals.Since animal experiments cannot be completely avoided, the pain, suffering, and distress of laboratory animals must be minimized. To this end, a major prerequisite is reliable assessment of pain and distress. Usually, evaluation of animal welfare is done by visual inspection and score sheets. However, relatively little is known about whether standardized, but subjective, score sheets are able to reliably reflect the status of the animals. The current study aimed to compare visual assessment scores and changes in body weight with concentrations of fecal corticosterone metabolites (FCMs) in a neuroscientific experimental setup. Additionally, effects of refinement procedures were investigated. Eight male adult Sprague-Dawley rats underwent several experimental interventions, including electroencephalograph electrode implantation and subsequent recording, positron emission tomography (PET), and sleep deprivation (SD) by motorized activity wheels. Additional 16 rats were either used as controls without any treatment or to evaluate refinement strategies. Stress responses were determined on a daily basis by means of measuring FCMs, body weight, and evaluation of the animals’ welfare by standardized score sheets. Surgery provoked a significant elevation of FCM levels for up to five days. Increases in FCMs due to PET procedures or SD in activity wheels were also highly significant, while visual assessment scores did not indicate elevated stress levels and body weights remained constant. Visual assessment scores correlate with neither changes in body weight nor increases in FCM levels. Habituation procedures to activity wheels used for SD had no impact on corticosterone release. Our results revealed that actual score sheets for visual assessment of animal welfare did not mirror physiological stress responses assessed by FCM measurements. Moreover, small changes in body weight did not correlate with FCM concentration either. In conclusion, as visual assessment is a method allowing immediate interventions on suffering animals to alleviate burden, timely stress assessment in experimental rodents via score sheets should be ideally complemented by validated objective measures (e.g., fecal FCM measured by well-established assays for reliable detection of FCMs). This will complete a comprehensive appraisal of the animals’ welfare status in a retrospective manner and refine stressor procedures in the long run.

Combination Pharmacological Interventions for Smoking Cessation and Post-Cessation Weight Gain: A Meta-Analysis of Randomized Controlled Trials

Objective: Limited evidence exists concerning whether combined pharmacotherapy is more effective than monotherapy for increased smoking abstinence and post-cessation weight gain prevention. This research investigated the effect of combined pharmacotherapy on smoking abstinence and post-cessation weight change.Methods: A meta-analytic review of Randomized Controlled Trials (RCTs) published between January 1990 and July 2016 was conducted across PubMed, International Pharmaceutical Abstracts, Web of Science, and Cochrane Library. Aggregate fixed effects were estimated for continuous abstinence and mean post-cessation weight change. Keyword search terms included: “smoking cessation,” “naltrexone”, “varenicline”, and “bupropion”.Results: Eight RCTs with 2,513 participants were included. Aggregate fixed effect estimates revealed an increase in continuous smoking abstinence (OR = 1.81, p < .001) and mean decrease in post-cessation weight change (-.15 kg, p = .001). Decreased weight change was observed at 6-8 weeks follow-up (-.14 kg, p = .02). Increased mean weight change was observed among varenicline plus nicotine patch abstainers (.21 kg, p = .01), whereas bupropion plus NRT pharmacotherapies showed decreased mean weight change (-.15 kg, p = .01).Conclusion: Combination pharmacotherapy generates increased smoking abstinence and small short-term post-cessation weight change among abstainers, particularly among bupropion plus NRT when compared against varenicline plus nicotine patch.

COVID-19-Related Home Confinement in Adults: Weight Gain Risks and Opportunities.

As the global COVID-19 pandemic unfolds, over 90% of U.S. adult residents are confined to their homes, with restaurants, shops, schools, and workplaces shut down to prevent disease spread. While it is a priority to mitigate the immediate impact, one area of great concern is the long-term effects of this pandemic on weight management in adults. As evident from previous research, small changes in body weight in relatively short time periods can become permanent and lead to substantial weight gain over time(1). Considering that the current situation could last a total of several months, this extended home confinement could exacerbate the problem of obesity in adults by substantially contributing to or exceeding annual weight gain.

Pregnancy Outcomes after Preeclampsia: The Effects of Interpregnancy Weight Change.

This study aimed to examine the effects of interpregnancy weight change on pregnancy outcomes, including recurrent preeclampsia, preterm birth, small-for-gestational age (SGA), large-for-gestational age (LGA), and cesarean delivery, among women with a history of preeclampsia. We also evaluated whether these associations were modified by prepregnancy body mass index (BMI) category in the first pregnancy (BMI < 25 vs. ≥25 kg/m2) and if associations were present among women who maintained a healthy BMI category in both pregnancies. We conducted a population-based retrospective cohort study including 15,108 women who delivered their first two nonanomalous singleton live births in Missouri (1989-2005) and experienced preeclampsia in the first pregnancy. We performed Poisson regression with robust error variance to estimate relative risks and 95% confidence intervals for outcomes of interest after controlling for potential confounders. Interpregnancy weight gain was associated with increased risk of recurrent preeclampsia, LGA, and cesarean delivery. These risks increased in a "dose-response" manner with increasing magnitude of interpregnancy weight gain and were generally more pronounced among women who were underweight or normal weight in the first pregnancy. Interpregnancy weight loss exceeding 1 BMI unit was associated with increased risk of SGA among underweight and normal weight women, while interpregnancy weight loss exceeding 2 BMI units was associated with reduced risk of recurrent preeclampsia among overweight and obese women. Even small changes in interpregnancy weight may significantly affect pregnancy outcomes among formerly preeclamptic women. Appropriate weight management between pregnancies has the potential to attenuate such risks. · Interpregnancy weight change among formerly preeclamptic women significantly affects pregnancy outcomes.. · Interpregnancy weight gain is associated with increased risk of recurrent preeclampsia, large-for-gestational-age and cesarean delivery.. · Interpregnancy weight loss is associated with increased risk of small-for-gestational age and recurrent preeclampsia..

EVALUATION OF TRIBOLOGICAL PROPERTIES OF POWDER PAINT COATINGS USING THE BALL-CRATERING METHOD

The basic method for protecting industrial products against the destructive impact of the environment is to protect them with paint coatings. One of the important characteristics of paint coatings is their resistance to abrasive wear. The study tested three coatings with different granulations obtained by the electrostatic spraying method and then polymerised. The tests were carried out in two ways. Some of them were conducted in accordance with the standards in place at the paint manufacturer’s laboratory, while the testing for abrasive wear resistance was conducted at a laboratory of the University of Warmia and Mazury in Olsztyn. The study involved measurements of thickness, gloss, scratching resistance, and wear using a rotational abrasion susceptibility tester and the ball-cratering method. Based on the obtained results, a different resistance to wear of particular coatings was found depending on the test stand. The study found the suitability of the ballcratering method for the assessment of wear resistance of thin paint coatings. The proposed methodology omits the problem of measuring very small changes in weight, while the obtained wear results are linked to other characteristics of the surface layer.

Research on Oxidation Resistance of Silicon Carbide Refractories to High Temperature Steam

Refractory linings of waste incineration plants based on oxidation resistant SiC materials enable a long service life at suitable firing and operation conditions. Steam oxidation resistance of Si3N4-SiC, SiO2-SiC, SiAlON-SiC material at 1000°C was tested according to ASTM-C863 after 50c, 100h, 200h, 250h and300h respectively. The phase composition and microstructure before and after oxidation were analyzed by means of XRD and SEM. Results indicate that there is continuous increase of volume expansion and weight change on materials with the oxidation to the oxidation time. After 50h of oxidation, a small amount of cristobalite can be observed in these materials, which comes directly from the oxidation of SiC, Si2N2O and SiAlON or from the crystallization of glass phase. Oxidation weight gain occurs in the first 50 h, but volume expansion takes place after 50h . Compared with the three materials, SiO2-SiC material has a smaller weight change and volume expansion. Comparing the SEM these three materials, it is obvious that SiO2-SiC material has a better density after 300h. Based on the above results, conclusions can be reached that: the sample of SiO2-SiC has better oxidation resistance and is more suitable as lining material of waste incinerator.

Repeated humidity cycling’s effect on physical properties of three kinds of wood-based panels

Physical proprieties of particleboard, medium-density fiberboard, and wood-plastic composite board were studied by measuring the thickness and weight changes during repeated humidity cycling (RHC). The thickness stability, moisture absorbing capacity, and internal band strength of the control and treated specimens were measured for the three tested materials. The wood-plastic composite board showed the greatest stability, with only small changes in thickness and weight. Temperature is a key component of RHC treatment, with greater thickness changes after six cycles at 50 °C than after nine cycles at 20 °C. Compared with the control materials, the thickness stability of RHC-treated materials was decreased by 23.7 to 31.8%; RHC decreased the internal bond strength of specimens 22 to 23% for particleboard and medium-density fiberboard and 2.15% for wood-plastic composite board. Overall, thickness stability and internal bonding strength of the tested materials were highly correlated.

Precision DEER Distances from Spin-Label Ensemble Refinement.

Double electron-electron resonance (DEER) experiments probe nanometer-scale distances in spin-labeled proteins and nucleic acids. Rotamer libraries of the covalently attached spin-labels help reduce position uncertainties. Here we show that rotamer reweighting is essential for precision distance measurements, making it possible to resolve Ångstrom-scale domain motions. We analyze extensive DEER measurements on the three N-terminal polypeptide transport-associated (POTRA) domains of the outer membrane protein Omp85. Using the "Bayesian inference of ensembles" maximum-entropy method, we extract rotamer weights from the DEER measurements. Small weight changes suffice to eliminate otherwise significant discrepancies between experiments and model and unmask 1-3 Å domain motions relative to the crystal structure. Rotamer-weight refinement is a simple yet powerful tool for precision distance measurements that should be broadly applicable to label-based measurements including DEER, paramagnetic relaxation enhancement, and fluorescence resonance energy transfer (FRET).

Weight Changes After Thyroid Surgery for Patients with Benign Thyroid Nodules and Thyroid Cancer: Population-Based Study and Systematic Review and Meta-Analysis

A key concern among patients who undergo thyroid surgery is postoperative weight gain. Yet, the impact of thyroid surgery on weight is unclear. The population-based Rochester Epidemiology Project was used to examine weight and body mass index (BMI) changes at one, two, and three years of follow-up in (i) patients with thyroid cancer and benign thyroid nodules after thyroid surgery, and (ii) patients with thyroid nodules who did not have surgery. A comprehensive systematic review of the published literature from inception to February 2016 was also conducted. The results were pooled across studies using a random effects model. A total of 435 patients were identified: 181 patients with thyroid cancer who underwent surgery (group A), 226 patients with benign thyroid nodules without surgery (group B), and 28 patients with benign thyroid nodules undergoing surgery (group C). Small changes in mean weight, BMI, and the number of patients whose weight increased between 5 and 10 kg were similar during each year of follow-up between patients in groups A and B. Furthermore, age >50 years, female sex, baseline BMI >25 kg/m2, and thyrotropin value at one to two years were not predictors of a 5% weight change. In the meta-analysis, 11 studies were included. One to two years after surgery for thyroid cancer or thyroid nodules, patients gained on average 0.94 kg [confidence interval (CI) 0.58-1.33] and 1.07 kg [CI 0.26-1.87], respectively. Patients with benign thyroid nodules who did not have surgery gained 1.50 kg [CI 0.60-2.4] at the longest follow-up. On average, patients receiving care for thyroid nodules or cancer gain weight, but existing evidence suggests that surgery for these conditions does not contribute significantly to further weight gain. Clinicians and patients can use this information to discuss what to expect after thyroid surgery.

Technical note: Comparison of metal-on-metal hip simulator wear measured by gravimetric, CMM and optical profiling methods

Simulation of wear in artificial joint implants is critical for evaluating implant designs and materials. Traditional protocols employ the gravimetric method to determine the loss of material by measuring the weight of the implant components before and after various test intervals and after the completed test. However, the gravimetric method cannot identify the location, area coverage or maximum depth of the wear and it has difficulties with proportionally small weight changes in relatively heavy implants. In this study, we compare the gravimetric method with two geometric surface methods; an optical light method (RedLux) and a coordinate measuring method (CMM). We tested ten Adept hips in a simulator for 2 million cycles (MC). Gravimetric and optical methods were performed at 0.33, 0.66, 1.00, 1.33 and 2 MC. CMM measurements were done before and after the test. A high correlation was found between the gravimetric and optical methods for both heads (R2 = 0.997) and for cups (R2 = 0.96). Both geometric methods (optical and CMM) measured more volume loss than the gravimetric method (for the heads, p = 0.004 (optical) and p = 0.08 (CMM); for the cups p = 0.01 (optical) and p = 0.003 (CMM)). Two cups recorded negative wear at 2 MC by the gravimetric method but none did by either the optical method or by CMM. The geometric methods were prone to confounding factors such as surface deformation and the gravimetric method could be confounded by protein absorption and backside wear. Both of the geometric methods were able to show the location, area covered and depth of the wear on the bearing surfaces, and track their changes during the test run; providing significant advantages to solely using the gravimetric method.