bluuebunny/crossref_metadata_2025_split huggingface dataset:
A three‐phase thermo‐hydro‐mechanical finite element model for freezing soils
Authors: Zhou M.M. , Meschke G. 
Published: April 2013

SUMMARYArtificial ground freezing (AGF) is a commonly used technique in geotechnical engineering for ground improvement such as ground water control and temporary excavation support during tunnel construction in soft soils. The main potential problem connected with this technique is that it may produce heave and settlement at the ground surface, which may cause damage to the surface infrastructure. Additionally, the freezing process and the energy needed to obtain a stable frozen ground may be significantly influenced by seepage flow. Evidently, safe design and execution of AGF require a reliable prediction of the coupled thermo‐hydro‐mechanical behavior of freezing soils. With the theory of poromechanics, a three‐phase finite element soil model is proposed, considering solid particles, liquid water, and crystal ice as separate phases and mixture temperature, liquid pressure, and solid displacement as the primary field variables. In addition to the volume expansion of water transforming into ice, the contribution of the micro‐cryo‐suction mechanism to the frost heave phenomenon is described in the model using the theory of premelting dynamics. Through fundamental physical laws and corresponding state relations, the model captures various couplings among the phase transition, the liquid transport within the pore space, and the accompanying mechanical deformation. The verification and validation of the model are accomplished by means of selected analyses. An application example is related to AGF during tunnel excavation, investigating the influence of seepage flow on the freezing process and the time required to establish a closed supporting frozen arch. Copyright © 2013 John Wiley & Sons, Ltd.
Visceral fat resection in humans: Effect on insulin sensitivity, beta‐cell function, adipokines, and inflammatory markers
Authors: Lima Marcelo M. O. , Pareja Jose C. , Alegre Sarah M. , Geloneze Sylka R. , Kahn Steven E. , Astiarraga Brenno D. , Chaim Élinton A. , Baracat Jamal , Geloneze Bruno 
Published: April 2013

AbstractObjective: The visceral fat is linked to insulin resistance, the metabolic syndrome, type 2 diabetes and an increased cardiovascular risk, but it is not clear whether it has a causative role.Design and Methods: Surgical resection of this fat depot is a research model to address this issue. Twenty premenopausal women with metabolic syndrome and grade III obesity were randomized to undergo Roux‐en‐Y gastric bypass (RYGBP) either alone or combined with omentectomy. Insulin sensitivity (IS; euglycemic‐hyperinsulinemic clamp), acute insulin response to glucose (AIR; intravenous glucose tolerance test), disposition index (DI = AIR × IS measured by clamp), lipid profile, adipokine profile (leptin, adiponectin, resistin, visfatin, interleukin‐6, TNF‐α, MCP‐1), ultra‐sensitive C‐reactive protein (CRP), body composition, and abdominal fat echography were assessed prior to surgery and 1, 6, and 12 months post‐surgery.Results: Omentectomy was associated with greater weight loss at all time points. IS improved similarly in both groups. Omentectomy was associated to lower CRP after 12 months, but it did not influence adipokines and other metabolic parameters. Among non‐diabetic subjects, omentectomy was associated with a preservation of baseline AIR after 12 months (as opposed to deterioration in the control group) and a greater DI after 6 and 12 months.Conclusion: Although omentectomy did not enhance the effect of RYGBP on insulin sensitivity and adipokines, it was associated with a preservation of insulin secretion, a greater weight loss, and lower CRP.
A dairy‐based high calcium diet improves glucose homeostasis and reduces steatosis in the context of preexisting obesity
Authors: Thomas Anthony P. , Dunn Tamara N. , Drayton Josephine B. , Oort Pieter J. , Adams Sean H. 
Published: April 2013

AbstractObjective:High dietary calcium (Ca) in the context of a dairy food matrix has been shown to reduce obesity development and associated inflammation in diet‐induced obese (DIO) rodents. The influence of Ca and dairy on these phenotypes in the context of preexisting obesity is not known. Furthermore, interpretations have been confounded historically by differences in body weight gain among DIO animals fed dairy‐based protein or high Ca.Design and Methods:Adiposity along with associated metabolic and inflammatory outcomes were measured in DIO mice previously fattened for 12 week on a soy protein‐based obesogenic high fat diet (45% energy, 0.5% adequate Ca), then fed one of three high fat diets (n = 29‐30/group) for an additional 8 week: control (same as lead‐in diet), high‐Ca (1.5% Ca), or high‐Ca + nonfat dry milk (NFDM).Results and Conclusion:Mice fed high‐Ca + NFDM had modestly, but significantly, attenuated weight gain compared to mice fed high‐Ca or versus controls (P < 0.001), whereas mice fed high‐Ca alone had increased weight gain compared to controls (P < 0.001). Total measured adipose depot weights between groups were similar, as were white adipose tissue inflammation and macrophage infiltration markers (e.g. TNFα, IL‐6, CD68 mRNAs). Mice fed high‐Ca + NFDM had significantly improved glucose tolerance following a glucose tolerance test, and markedly lower liver triglycerides compared to high‐Ca and control groups. Improved metabolic phenotypes in prefattened DIO mice following provision of a diet enriched with dairy‐based protein and carbohydrates appeared to be driven by non‐Ca components of dairy and were observed despite minimal differences in body weight or adiposity.
Six‐minute walk test before and after a weight reduction program in obese subjects
Authors: Ekman Maja J. , Klintenberg M. , Björck U. , Norström F. , Ridderstråle M. 
Published: April 2013

AbstractObejctive: Weight loss and physical activity have shown favorable effects on risks associated with obesity. It is therefore of interest to evaluate exercise capacity and related co‐morbidities in obese patients.Design and Methods: We present data from obese subjects evaluated by the 6‐minute walk test (6MWT) before and after a 7.3 (6.1‐8.2) month weight reduction program.Results: 251 subjects completed the test at baseline (BMI 40.6 [36.9‐44.6] kg/m2) and 129 (51.4%) repeated the test after intervention (BMI 35.6 [31.2‐38.5] kg/m2). The six minute walking distance (6MWD) at baseline (535 [480‐580] m) and at follow up (599 [522‐640] m) correlated to several cardiovascular risk markers. Age, weight, height, resting heart rate, smoking status, fP‐glucose and use of β‐blockers explained 43 % of the variance in predicted 6MWD at baseline. The effect of smoking status, fP‐glucose, β‐blockers, and resting heart rate lost significance at follow up. Presence of diabetes and the metabolic syndrome had a negative influence on 6MWD but did not affect the impact of intervention based on percentage increase in walking distance. Gender had no impact on 6MWD. Reported pain during the test was common but decreased after intervention (57.0% vs. 28.7%, P < 0.001).Conclusions:The 6MWT may be used to evaluate intervention success beyond kilogram weight loss in obese subjects. We present formulas to predict 6MWD and the effect of weight loss on walking distance in clinical practice. Pain is a common problem which has to be considered when giving advice on exercise as a part of weight loss intervention.
Endothelial function and weight loss: Comparison of low‐carbohydrate and low‐fat diets
Authors: Mohler Emile R. , Sibley Alexandra A. , Stein Richard , Davila‐Roman Victor , Wyatt Holly , Badellino Karen , Rader Daniel J. , Klein Samuel , Foster Gary D. 
Published: April 2013

AbstractObjective: The effect of weight loss on obesity‐associated endothelial dysfunction is not clear because of conflicting data, demonstrating both improvement and no change in endothelial function after weight loss in obese subjects. A 2‐year prospective study (n = 121) was conducted to examine: (1) the effect of obesity and weight loss (either a low‐carbohydrate or and low‐fat diet) on flow mediated vasodilatation (FMD), a measure of endothelial function.Design and Methods: Participants reduced body weight by 7.1% ± 4.4%, 8.7% ± 6.8%, 7.1% ± 7.8%, and 4.1% ± 7.7% at 3, 6, 12, and 24 months, respectively with no significant differences between the low‐fat and low‐carbohydrate groups.Results: Endothelial function was inversely correlated with waist circumference, triglyceride level, and directly correlated with leptin in obese persons prior to weight loss. These weight losses did not confer any improvements in FMD. There were no differences between the low‐fat and low‐carbohydrate diets in FMD at any time point. At 6 months (r = 0.26, P = 0.04) and 1 year (r =0.28, P = 0.03), there were positive correlations between change in FMD and change in leptin but not at 2 years.Conclusion: There was no significant improvement in endothelial function after 7.1% ± 7.8% weight loss at 1 year and 4.1% ± 7.7% at 2 years, achieved by either a low carbohydrate or a low fat diet.
Gastric Helicobacter pylori infection is associated with adverse metabolic traits in severely obese subjects
Authors: Gerig Rahel , Ernst Barbara , Wilms Britta , Thurnheer Martin , Schultes Bernd 
Published: April 2013

AbstractObjective:Asian studies have reported on an association of Helicobacter pylori (Hp) infection with insulin resistance (IR) in normal‐weight subjects. Whether such an association likewise exists in European subjects with severe obesity was questioned.Design and Methods:To address this question, 370 severely obese patients from our database were identified, who had undergone a gastroscopy with a histological examination of gastric mucosal biopsies and a concurrent assessment metabolic blood parameters as a standard examination before bariatric surgery.Results:Seventy‐five (20.3%) of the subjects displayed a histologically proven Hp infection (Hp+). Sex distribution, age, and body mass index of Hp+ subjects did not differ from that of the subjects with no Hp infection (Hp–; all P > 0.293), but Hp+ subjects were significantly smaller (P = 0.006). Fasting glucose, insulin, high‐sensitive C reactive protein, and alanine aminotransferase levels as well as calculated indices of IR (i.e., HOMA‐IR, QUICKI) did not differ between Hp+ and Hp– subjects (all P > 0.42). However, Hp+ subjects showed significantly higher triglyceride levels and a higher total chloesterol‐to‐HDL ratio but lower sex‐hormone binding globulin (SHGB) levels than Hp– subjects (all P ≤ 0.05).Conclusion:While our results obtained in European severely obese patients do not provide evidence for an enhanced IR state associated with gastric Hp infection, they suggest that the presence of the bacterium in gastric biopsies is associated with an adverse lipid profile and reduced SHGB levels.
Meta‐analysis of the association between body mass index and health‐related quality of life among adults, assessed by the SF‐36
Authors: Ul‐Haq Zia , Mackay Daniel F. , Fenwick Elisabeth , Pell Jill P. 
Published: April 2013

AbstractObjective:Obesity is associated with impaired overall health‐related quality of life but individual studies suggest the relationship may differ for mental and physical quality of life. A systematic review using Medline, Embase, PsycINFO and ISI Web of Knowledge, and random effects meta‐analysis was undertaken.Design and Methods:Studies were included in the meta‐analysis if they were conducted on adults (defined as age >16 years), reported an overall physical and mental component score of the SF‐36, and, or both. Heterogeneity was assessed using I2 statistics and publication and small study biases using funnel plots and Egger's test. Between‐study heterogeneity was explored using meta‐regression.Results:Eight eligible studies provided 42 estimates of effect size, based on 43,086 study participants. Adults with higher than normal body mass index had significantly reduced physical quality of life with a clear dose‐response relationship across all categories. Among class III obese adults, the score was reduced by 9.72 points (95% Confidence Interval 7.24, 12.20, P < 0.001). Mental quality of life was also significantly reduced among class III obese (−1.75, 95% confidence interval −3.33, −0.16, P = 0.031), but was not significantly different among obese (class I and class II) individuals, and was significantly increased among overweight adults (0.42, 95% confidence interval 0.17, 0.67, P = 0.001), compared to normal weight individuals. Heterogeneity was high in some categories, but there was no significant publication or small study bias.Conclusions:Different patterns were observed for physical and mental HRQoL, but both were impaired in obese individuals. This meta‐analysis provides further evidence on the impact of obesity on both aspects of health‐related quality of life.
Epicardial adipose tissue assessed by cardiac magnetic resonance imaging in patients with heart failure due to dilated cardiomyopathy
Authors: Doesch Christina , Streitner Florian , Bellm Steven , Suselbeck Tim , Haghi Dariusch , Heggemann Felix , Schoenberg Stefan O. , Michaely Henrik , Borggrefe Martin , Papavassiliu Theano 
Published: April 2013

AbstractObjective:We sought to investigate the association of the EAT with CMR parameters of ventricular remodelling and left ventricular (LV) dysfunction in patients with non‐ischemic dilated cardiomyopathy (DCM).Design and Methods:One hundred and fifty subjects (112 consecutive patients with DCM and 48 healthy controls) underwent CMR examination. Function, volumes, dimensions, the LV remodelling index (LVRI), the presence of late gadolinium enhancement (LGE) and the amount of EAT were assessed.Results:Compared to healthy controls, patients with DCM revealed a significantly reduced indexed EAT mass (31.7 ± 5.6 g/m2 vs 24.0 ± 7.5 g/m2, p<0.0001). There was no difference in the EAT mass between DCM patients with moderate and severe LV dysfunction (23.5 ± 9.8 g/m2 vs 24.2 ± 6.6 g/m2, P = 0.7). Linear regression analysis in DCM patients showed that with increasing LV end‐diastolic mass index (LV‐EDMI) (r = 0.417, P < 0.0001), increasing LV end‐diastolic volume index (r = 0.251, P = 0.01) and increasing LV end‐diastolic diameter (r = 0.220, P = 0.02), there was also a significantly increased amount of EAT mass. However, there was no correlation between the EAT and the LV ejection fraction (r = 0.0085, P = 0.37), right ventricular ejection fraction (r = 0.049, P = 0.6), LVRI (r = 0.116, P = 0.2) and the extent of LGE % (r = 0.189, P = 0.1). Among the healthy controls, the amount of EAT only correlated with increasing age (r = 0.461, P = 0.001), BMI (r = 0.426, P = 0.003) and LV‐EDMI (r = 0.346, P = 0.02).Conclusion:In patients with DCM the amount of EAT is decreased compared to healthy controls irrespective of LV function impairment. However, an increase in LV mass and volumes is associated with a significantly increase in EAT in patients with DCM.
Placental weight mediates the effects of prenatal factors on fetal growth: the extent differs by preterm status
Authors: Ouyang Fengxiu , Parker Margaret , Cerda Sandra , Pearson Colleen , Fu Lingling , Gillman Matthew W. , Zuckerman Barry , Wang Xiaobin 
Published: April 2013

AbstractObjective:Elevated pre‐pregnancy BMI, excessive gestational weight gain (GWG), and gestational diabetes mellitus (GDM) are known determinants of fetal growth. The role of placental weight is unclear. We aimed to examine the extent to which placental weight mediates the associations of pre‐pregnancy BMI, GWG, and GDM with birth weight‐for‐gestational age, and whether the relationships differ by preterm status.Design and Methods:We examined 1,035 mother‐infant pairs at birth from the Boston Birth Cohort. Data were collected by questionnaire and clinical measures. Placentas were weighed without membranes or umbilical cords. We performed sequential models excluding and including placental weight, stratified by preterm status.Results:We found that 21% of mothers were obese, 42% had excessive GWG, and 5% had GDM. Forty‐one percent were preterm. Among term births, after adjustment for sex, gestational age, maternal age, race, parity, education, smoking, and stress during pregnancy, birth weight‐for‐gestational age z‐score was 0.55 (0.30, 0.80) units higher for pre‐pregnancy obesity vs. normal weight. It was 0.34 (0.13, 0.55) higher for excessive vs. adequate GWG, 0.67 (0.24, 1.10) for GDM vs. no DM, with additional adjustment for pre‐pregnancy BMI. Adding placental weight to the models attenuated the estimates for pre‐pregnancy obesity by 20%, excessive GWG by 32%, and GDM by 21%. Among preterm infants, GDM was associated with 0.67 (0.34, 1.00) higher birth weight‐for‐gestational age z‐score, but pre‐pregnancy obesity and excessive GWG were not. Attenuation by placental weight was 36% for GDM.Conclusions:These results suggest that placental weight partially mediates the effects of pre‐pregnancy obesity, GDM, and excessive GWG on fetal growth among term infants.
Diet composition and activity level of at risk and metabolically healthy obese american adults
Authors: Hankinson Arlene L. , Daviglus Martha L. , Horn Linda Van , Chan Queenie , Brown Ian , Holmes Elaine , Elliott Paul , Stamler Jeremiah 
Published: April 2013

AbstractObjective:Obesity often clusters with other major cardiovascular disease risk factors, yet a subset of the obese appears to be protected from these risks. Two obesity phenotypes are described, (i) “metabolically healthy” obese, broadly defined as body mass index (BMI) ≥ 30 kg/m2 and favorable levels of blood pressure, lipids, and glucose; and (ii) “at risk” obese, BMI ≥ 30 with unfavorable levels of these risk factors. More than 30% of obese American adults are metabolically healthy. Diet and activity determinants of obesity phenotypes are unclear. We hypothesized that metabolically healthy obese have more favorable behavioral factors, including less adverse diet composition and higher activity levels than at risk obese in the multi‐ethnic group of 775 obese American adults ages 40‐59 years from the International Population Study on Macro/Micronutrients and Blood Pressure (INTERMAP) cohort.Design and Methods:In gender‐stratified analyses, mean values for diet composition and activity behavior variables, adjusted for age, race, and education, were compared between metabolically healthy and at risk obese.Results:Nearly one in five (149/775 or 19%) of obese American INTERMAP participants were classified as metabolically healthy obese. Diet composition and most activity behaviors were similar between obesity phenotypes, although metabolically healthy obese women reported higher sleep duration than at risk obese women.Conclusions:These results do not support hypotheses that diet composition and/or physical activity account for the absence of cardiometabolic abnormalities in metabolically healthy obese.
A Novel Approach in Herbal Quality Control Using Hyperspectral Imaging: Discriminating Between Sceletium tortuosum and Sceletium crassicaule
Authors: Shikanga Emmanuel Amukohe , Viljoen Alvaro M. , Vermaak Ilze , Combrinck Sandra 
Published: April 2013

ABSTRACTIntroductionSceletium tortuosum is the most sought after species of the genus Sceletium and is commonly included in commercial products for the treatment of psychiatric conditions and neurodegenerative diseases. However, this species exhibits several morphological and phytochemical similarities to S. crassicaule.ObjectivesThe aim of this investigation was to use ultrahigh‐performance liquid chromatography (UPLC) and hyperspectral imaging, in combination with chemometrics, to distinguish between S. tortuosum and S. crassicaule, and to accurately predict the identity of specimens of both species.MethodsChromatographic profiles of S. tortuosum and S. crassicaule specimens were obtained using UPLC with photodiode array detection. A SisuChema near infrared hyperspectral imaging camera was used for acquiring images of the specimens and the data was processed using chemometric computations.ResultsChromatographic data for the specimens revealed that both species produce the psychoactive alkaloids that are used as quality control biomarkers. Principal component analysis of the hyperspectral image of reference specimens for the two species yielded two distinct clusters, the one representing S. tortuosum and the other representing S. crassicaule. A partial least squares discriminant analysis model correctly predicted the identity of an external dataset consisting of S. tortuosum or S. crassicaule samples with high accuracy (>94%).ConclusionsA combination of hyperspectral imaging and chemometrics offers several advantages over conventional chromatographic profiling when used to distinguish S. tortuosum from S. crassicaule. In addition, the constructed chemometric model can reliably predict the identity of samples of both species from an external dataset. Copyright © 2013 John Wiley & Sons, Ltd.
Noninvasive twin zygosity assessment and aneuploidy detection by maternal plasma DNA sequencing
Authors: Leung Tak Y. , Qu James Z. Z. , Liao Gary J. W. , Jiang Peiyong , Cheng Yvonne K. Y. , Chan K. C. Allen , Chiu Rossa W. K. , Lo Y. M. Dennis 
Published: April 2013

ABSTRACTObjectiveThis study aimed to provide an individualized assessment of fetal trisomy 21 and trisomy 18 status for twin pregnancies by maternal plasma DNA sequencing.MethodMassively parallel sequencing was performed on the plasma/serum DNA libraries of eight twin pregnancies and 11 singleton pregnancies. The apparent fractional fetal DNA concentrations between genomic regions were assessed to determine the zygosities of the twin pregnancies and to calculate the fetal DNA concentrations of each individual member of dizygotic twin pairs. Z‐scores were determined for the detection of trisomy 18 and trisomy 21.ResultsCirculating DNA sequencing showed elevated chromosome 21 representation in one set of twins and elevated chromosome 18 representation in another pair of twins. Apparent fractional fetal DNA concentration analysis revealed both sets of twins to be dizygotic. The fractional fetal DNA concentrations for each individual fetus of the dizygotic twin pregnancies were determined. Incorporating the information about the fetal DNA fraction, we ascertained that each fetus contributed adequate amounts of DNA into the maternal circulation for the aneuploidy test result to be interpreted with confidence.ConclusionNoninvasive prenatal assessment of fetal chromosomal aneuploidy for twin pregnancies can be achieved with the use of massively parallel sequencing of cell‐free DNA in maternal blood. © 2013 John Wiley & Sons, Ltd.