bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher Post‐absorptive Skeletal Muscle LPL Activity in African American vs. Non‐Hispanic White Pre‐menopausal Women
Authors: Berk Evan S. , Johnson Julia A. , Lee MiJeong , Zhang Kuan , Boozer Carol N. , Pi‐Sunyer F. Xavier , Fried Susan K. , Albu Jeanine B.
Published: January 2008

Objective: Higher post‐absorptive post‐heparin plasma lipoprotein lipase (LPL) activity has been reported in African Americans as compared to non‐Hispanic whites but differences in tissue‐specific LPL activity are unclear.

Methods and Procedures: Post‐absorptive skeletal muscle (SM)‐LPL (vastus lateralis) and subcutaneous abdominal adipose tissue (AT)‐LPL activity was measured in overweight, sedentary African American females (n = 11) as well as in their non‐Hispanic white counterparts (n = 6) during a period of controlled low fat (30%) diet (for 10 days) combined with physical activity (for days 8–10). Post‐absorptive substrate utilization was measured on day 10; fasting blood levels and SM and AT biopsies were obtained on day 11.

Results: African Americans had significantly greater post‐absorptive SM‐LPL activity (P = 0.04) when compared to non‐Hispanic whites. There were no significant differences in post‐absorptive AT‐LPL activity, free fatty acids, and systemic fat oxidation or respiratory quotient between African American and white non‐Hispanic women in this study (P > 0.2 for all).

Discussion: During a controlled low fat (30%) diet post‐absorptive vastus lateralis SM‐LPL activity is higher in sedentary pre‐menopausal African American as compared to non‐Hispanic white women.
Aspects of Eating Behaviors “Disinhibition” and “Restraint” Are Related to Weight Gain and BMI in Women
Authors: Hays Nicholas P. , Roberts Susan B.
Published: January 2008

Objective: The causes of adult weight gain leading to obesity are uncertain. We examined the association of adult weight gain and obesity with subscales of eating behavior characteristics in older women.

Methods and Procedures: Current height and weight, eating behavior subscales (disinhibition subscales—habitual, situational, and emotional; restraint subscales—flexible and rigid; hunger subscales—internal and external) as assessed using the Eating Inventory (EI), and self‐reported body weight at six prior age intervals were reported by 535 women aged 55–65 years. Multiple regression analysis was used to examine the relationships between EI subscale scores and weight change from the age interval of 30–39 to 55–60 years and current BMI.

Results: The strongest correlate of weight gain over 20 years was susceptibility to overeating in response to everyday cues within the environment (habitual disinhibition; partial correlation coefficient (r) = 0.25, P < 0.001); susceptibility to overeating in response to emotional states such as depression (emotional disinhibition) was a quantitatively weaker but significant correlate (partial r = 0.17, P < 0.001), and susceptibility to overeating in response to specific situations such as social occasions (situational disinhibition) was not associated with weight gain. Flexible control of dietary restraint attenuated the influence of habitual disinhibition in particular on weight gain and BMI, and was less effective in attenuating associations of emotional or situational disinhibition.

Discussion: Lifestyle modification programs for prevention and treatment of adult‐onset obesity currently focus on reducing situational and emotional overeating; the results of this study suggest that a stronger emphasis on strategies that target habitual overeating may be warranted.
Gender Alters the Effects of Palmitate and Oleate on Fat Oxidation and Energy Expenditure
Authors: Kien C Lawrence , Bunn Janice Y.
Published: January 2008

Objective: Because estrogen and testosterone affect transcription factors regulating mitochondrial function, we assessed the effects of gender on the metabolic response to dietary palmitic acid (PA) vs. oleic acid (OA) in subjects participating in a previously described trial.

Methods and Procedures: Adults (N = 43) were studied after following a baseline diet (PA = 8.4% kcal, OA = 13.1% kcal) and after undergoing one of two experimental diets: high PA (HI PA) (PA = 16.8%, OA = 16.4% kcal) (N = 21; 11 men) or high OA (HI OA) (PA = 1.7%, and OA = 31.4%) (N = 22; 11 men).

Results: Relative to baseline, the rate of fatty acid (FA) oxidation (% resting energy expenditure(REE)) (mean ± s.e.m.) increased in women on HI OA while decreasing on HI PA in the fed (+11.8 ± 5.6% vs. −6.3 ± 4.2%, P = 0.02) and fasting states (+13.4 ± 4.2% vs. −12.7 ± 6.9%, P = 0.047), but changes in men were not statistically significant. Daily energy expenditure changed only in men, increasing on HI OA and decreasing on HI PA (+66 ± 61 kcal/day or 1.2 ± 1.0 kcal/kg fat‐free mass (FFM)/day vs. −266 ± 78 kcal/day or −4.2 ± 1.3 kcal/kg FFM/day, P = 0.004 and P = 0.007, respectively).

Discussion: Increased dietary PA/OA caused decreased FA oxidation in women, in the fed and fasted states and decreased daily energy expenditure (DEE) in men.
Usefulness of Truncal Obesity Indices as Predictive Factors for Obstructive Sleep Apnea Syndrome
Authors: Martinez‐Rivera Carlos , Abad Jorge , Fiz Jose A. , Rios Jose , Morera Josep
Published: January 2008

Background: Optimization of the indications for nocturnal polysomnography in the diagnosis of obstructive sleep apnea syndrome (OSAS) could lead to significant reductions in health expenditure. To this end, we assessed the usefulness of truncal obesity measurements in the diagnosis of OSAS.

Methods and Procedures: One hundred ninety‐two patients (152 men and 40 women) referred to our clinic with suspected OSAS underwent a complete polysomnography study and their BMI and truncal obesity measurements were obtained.

Results: Comparison of patients defined as snorers with OSAS patients, by means of the Student's t ‐test revealed significant differences in the truncal obesity parameters such as waist‐to‐hip ratio (0.94 vs. 0.98) and waist circumference (100.7 cm vs. 106.3 cm). We found no significant differences between BMI values in the two groups. Indices of truncal obesity were analyzed as predictive factors for OSAS using a multivariate logistic regression model that included variable sex, and in which waist‐to‐hip ratio, BMI, neck circumference, and age were analyzed as binary variables. According to this model, our patients' risk of suffering from OSAS was 2.6 times greater if the waist‐to‐hip ratio was >1 in men and >0.85 in women. The risk of OSAS was also increased if the patients were men or over 52 years of age.

Discussion: Obtaining simple measurements such as those for truncal obesity may help prioritize the use of polysomnography in patients with a greater risk of OSAS. Our results suggest that BMI is not a good predictor of OSAS in a group of patients with a high BMI.
No Association Between INSIG2 Gene rs7566605 Polymorphism and Being Overweight in Japanese Population
Authors: Tabara Yasuharu , Kawamoto Ryuichi , Osawa Haruhiko , Nakura Jun , Makino Hideichi , Miki Tetsuro , Kohara Katsuhiko
Published: January 2008

Obesity is a complex trait reflecting numerous genetic and environmental factors. Recently, a common genetic polymorphism (rs7566605) associated with a higher BMI was found in proximity to the insulin induced protein 2 (INSIG2) gene, with replication in four unrelated populations living in Western countries. We investigated the susceptibility to the polymorphism amongst the general Japanese population (n = 1976). The frequency of appearance of the single‐nucleotide polymorphism (SNP) in the Japanese (G allele; 0.652, C allele; 0.348) was not different from that found in subjects of European origin as reported previously. However, the BMI levels in each of these genotypes did not differ significantly (GG; 23 ± 3, GC; 24 ± 3, CC; 24 ± 3 kg/m2, P = 0.906). In a separate analysis according to sex (male; P = 0.462, female; P = 0.879), age decade (40s; P = 0.057, 50s; P = 0.998, 60s; P = 0.622, 70s; 0.425, respectively), and tertiles of the BMI (1st; P = 0.409, 2nd; P = 0.088, 3rd; P = 0.780), the differences did not achieve statistical significance. The frequency of obesity did not differ among the genotypes (25 kg/m2; 30.3, 30.8, 28.2%, P = 0.729, 30 kg/m2; 2.9, 3.8, 2.8%, P = 0.549). No associations were also observed for related plasma markers; high‐molecular weight (HMW) adiponectin (P = 0.510), high‐sensitive C‐reactive protein (P = 0.788), resistin (P = 0.937) and homeostasis of minimal assessment of insulin resistance (P = 0.634). These results indicate a lack of association between SNP rs7566605 and being overweight among the Japanese (in the middle‐aged and elderly population).
Obesity Alters Cytokine Gene Expression and Promotes Liver Injury in Rats With Acute Pancreatitis
Authors: Segersvärd Ralf , Tsai Jon A. , Herrington Margery K. , Wang Feng
Published: January 2008

Objective: Obesity is a negative prognostic factor in patients with critical illnesses such as acute pancreatitis (AP). The outcome of AP is determined by the severity of systemic inflammation and organ dysfunction. In a previous study, we found that AP caused more deaths in obese rats than in lean rats. In the present study, we examined whether the effect of obesity on rats with AP is associated with distinct alterations in inflammatory cytokine expression in organs involved in AP.

Methods and Procedures: AP was induced in lean and obese Zucker rats by pancreatic infusion of taurocholic acid. All survivors were killed 8 h later. Gene transcripts for two proinflammatory cytokines (interleukin‐6 (IL‐6) and tumor necrosis factor‐α (TNF‐α)) and two anti‐inflammatory cytokines (IL‐10 and pancreatitis‐associated protein (PAP)) were determined in the pancreas, liver, and lungs by quantitative real‐time polymerase chain reaction. The severity of AP was assessed by means of histology and serology.

Results: Obese AP rats had higher TNF‐α mRNA in all organs examined, lower IL‐10 and IL‐6 mRNA in the pancreas, and lower PAP mRNA in the liver, compared to lean AP rats. Lean and obese AP rats had similar pancreatic lesions as assessed by histology. However, steatohepatitis and increased serum alanine amino transferase levels, which are indications of hepatic injury, were present in obese but not lean AP rats.

Discussion: Our findings suggest that altered inflammatory cytokine expression and increased vulnerability in the liver underlie the detrimental influence of obesity on AP.
Validation of a Quantitative Magnetic Resonance Method for Measuring Human Body Composition
Authors: Napolitano Antonella , Miller Sam R. , Murgatroyd Peter R. , Coward W. Andrew , Wright Antony , Finer Nick , De Bruin Tjerk W. , Bullmore Edward T. , Nunez Derek J.
Published: January 2008

Objective: To evaluate a novel quantitative magnetic resonance (QMR) methodology (EchoMRI‐AH, Echo Medical Systems) for measurement of whole‐body fat and lean mass in humans.

Methods and Procedures: We have studied (i) the in vitro accuracy and precision by measuring 18 kg Canola oil with and without 9 kg water (ii) the accuracy and precision of measures of simulated fat mass changes in human subjects (n = 10) and (iii) QMR fat and lean mass measurements compared to those obtained using the established 4‐compartment (4‐C) model method (n = 30).

Results: (i) QMR represented 18 kg of oil at 40°C as 17.1 kg fat and 1 kg lean while at 30°C 15.8 kg fat and 4.7 kg lean were reported. The s.d. of repeated estimates was 0.13 kg for fat and 0.23 kg for lean mass. Adding 9 kg of water reduced the fat estimates, increased misrepresentation of fat as lean, and degraded the precision. (ii) the simulated change in the fat mass of human volunteers was accurately represented, independently of added water. (iii) compared to the 4‐C model, QMR underestimated fat and over‐estimated lean mass. The extent of difference increased with body mass. The s.d. of repeated measurements increased with adiposity, from 0.25 kg (fat) and 0.51 kg (lean) with BMI <25 kg/m2 to 0.43 kg and 0.81 kg respectively with BMI >30 kg/m2.

Discussion: EchoMRI‐AH prototype showed shortcomings in absolute accuracy and specificity of fat mass measures, but detected simulated body composition change accurately and with precision roughly three times better than current best measures. This methodology should reduce the study duration and cohort number needed to evaluate anti‐obesity interventions.
Dietary Fat Increases Energy Intake Across the Range of Typical Consumption in the United States
Authors: Donahoo William , Wyatt Holly R. , Kriehn Joanna , Stuht Jennifer , Dong Fang , Hosokawa Patrick , Grunwald Gary K. , Johnson Susan L. , Peters John C. , Hill James O.
Published: January 2008

Objective: The fat content of a diet has been shown to affect total energy intake, but controlled feeding trials have only compared very high (40% of total calories) fat diets with very low (20% of total calories) fat diets. This study was designed to measure accurately the voluntary food and energy intake over a range of typical intake for dietary fat.

Methods and Procedures: Twenty‐two non‐obese subjects were studied for 4 days on each of three diets, which included core foods designed to contain 26, 34, and 40% fat, respectively of total calories and ad lib buffet foods of similar fat content. All diets were matched for determinants of energy density except dietary fat. Subjects consumed two meals/day in an inpatient unit and were provided the third meal and snack foods while on each diet. All food provided and not eaten was measured by research staff.

Results: Voluntary energy intake increased significantly as dietary fat content increased (P = 0.008). On the 26% dietary fat treatment, subjects consumed 23.8% dietary fat (core and ad lib foods combined) and 2,748 ± 741 kcal/day (mean ± s.d.); at 34% dietary fat, subjects consumed 32.7% fat and 2,983 ± 886 kcal/day; and at 40% dietary fat subjects consumed 38.1% fat and 3,018 ± 963 kcal/day.

Discussion: These results show that energy intake increases as dietary fat content increases across the usual range of dietary fat consumed in the United States. Even small reductions in dietary fat could help in lowering total energy intake and reducing weight gain in the population.
GLP‐1 and Appetite Responses to a Meal in Lean and Overweight Adolescents Following Exercise
Authors: Chanoine Jean‐Pierre , Mackelvie Kerry J. , Barr Susan I. , Wong Alfred C.K , Meneilly Graydon S. , Elahi Dariush H.
Published: January 2008

Objective: Increased physical activity is an integral part of weight loss programs in adolescents. We prospectively investigated the effects of exercise on glucagon‐like peptide‐1 (GLP‐1) concentrations and on appetite markers.

Methods and Procedures: Normal weight (NW) and at risk of overweight/overweight (OW) male adolescents (n = 17/gr) underwent five consecutive days of aerobic exercise (1 h/day). A test meal was administered prior to the first exercise session and 36 hours following the last exercise session. GLP‐1 and markers of appetite were assessed.

Results: GLP‐1 concentrations over the course of the test meal were lower in OW compared to NW boys (P < 0.05), while fasting GLP‐1 concentrations tended to be lower in OW boys (0.05 < P < 0.1). Exercise caused an increase in the acute GLP‐1 response to the liquid meal (from 52 to 78%, P = 0.02) that was similar in NW and OW adolescents. OW adolescents expressed greater restraint compared to NW adolescents (three‐factor eating questionnaire, TFEQ) and there was a significant correlation between TFEQ for restraint score and BMI s.d. both before and after exercise intervention (P < 0.015). There was no significant correlation between markers of appetite and GLP‐1 concentrations.

Discussion: Lower concentrations of GLP‐1, a satiety hormone, in OW compared to NW male adolescents support the theory that GLP‐1 plays a role in the etiology of overweight. Whether the greater meal‐induced, 0–30 min GLP‐1 response following exercise is associated with increased satiety, a potentially beneficial effect of exercise, needs to be evaluated in larger studies.
Relationship Between Body Mass Index and Gray Matter Volume in 1,428 Healthy Individuals
Authors: Taki Yasuyuki , Kinomura Shigeo , Sato Kazunori , Inoue Kentaro , Goto Ryoi , Okada Ken , Uchida Shinya , Kawashima Ryuta , Fukuda Hiroshi
Published: January 2008

Objective: To investigate any correlation between BMI and brain gray matter volume, we analyzed 1,428 healthy Japanese subjects by applying volumetric analysis and voxel‐based morphometry (VBM) using brain magnetic resonance (MR) imaging, which enables a global analysis of brain structure without a priori identification of a region of interest.

Methods and Procedures: We collected brain MR images from 690 men and 738 women, and their height, weight, and other clinical information. The collected images were automatically normalized into a common standard space for an objective assessment of neuroanatomical correlations in volumetric analysis and VBM with BMI.

Results: Volumetric analysis revealed a significant negative correlation in men (P < 0.001, adjusting for age, lifetime alcohol intake, history of hypertension, and diabetes mellitus), although not in women, between BMI and the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume. VBM revealed that, in men, the regional gray matter volume of the bilateral medial temporal lobes, anterior lobe of the cerebellum, occipital lobe, frontal lobe, precuneus, and midbrain showed significant negative correlations with BMI, while those of the bilateral inferior frontal gyri, posterior lobe of the cerebellum, frontal lobes, temporal lobes, thalami, and caudate heads showed significant positive correlations with BMI.

Discussion: Global loss and regional alterations in gray matter volume occur in obese male subjects, suggesting that male subjects with a high BMI are at greater risk for future declines in cognition or other brain functions.
Effects of Diacylglycerol on Glucose, Lipid Metabolism, and Plasma Serotonin Levels in Lean Japanese
Authors: Yanai Hidekatsu , Yoshida Hiroshi , Tomono Yoshiharu , Hirowatari Yuji , Kurosawa Hideo , Matsumoto Akiyo , Tada Norio
Published: January 2008

Objective: Diacylglycerol (DAG)‐rich oil has been suggested to suppress postprandial hyperlipidemia and promote negative caloric balance by increasing energy expenditure (EE), due to small intestine physiochemical dynamics that differ from triacylglycerol (TAG). We studied the effect of DAG on postprandial glucose/insulin metabolism by loading of carbohydrate with oil. Further, to reveal the mechanism for increased EE by DAG, we measured plasma serotonin, which is mostly present in the small intestine and mediates peripheral sympathetic thermogenesis.

Methods and Procedures: Randomized crossover study with 2‐week wash‐out interval between differing fat ingestion. Seven male, lean, Japanese students ingested DAG or TAG oil with 40 g of carbohydrate. Measurements of metabolic parameters were performed before and at 2, 4, and 6 h after fat ingestion. Plasma serotonin levels and cholesterol concentration in each lipoprotein were measured using high‐performance liquid chromatography (HPLC).

Results: The substitution of DAG for TAG decreased very‐low‐density lipoprotein‐cholesterol (VLDL‐C) by 45.6% at 2 h, and decreased serum insulin by 41.3% at 4 h after ingestion. The incremental area under the curve (IAUC) for VLDL‐C was positively correlated with the IAUC for insulin. Concurrently, DAG elevated plasma serotonin levels by 47.3% at 2 h, while TAG did not influence.

Discussion: This study indicates that the substitution of DAG for TAG suppresses the postprandial increase in serum VLDL‐C and insulin. This study also demonstrates that DAG ingestion increases plasma serotonin, proposing a possible mechanism for a postprandial increase in EE by DAG.
Self‐selection Accounts for Inverse Association Between Weight and Cardiorespiratory Fitness
Authors: Williams Paul T.
Published: January 2008

Background: Men and women who exercise regularly and who are physically fit tend to be leaner than those who are sedentary and not fit. Although exercise is known to attenuate weight gain and promote weight loss, there may also be a propensity for leaner men and women to choose to exercise vigorously (self‐selection). Pre‐exercise body weights have been shown to account for all the weight differences between fast and slow walkers, but seem to account for only a portion of the weight differences associated with walking distances. Whether these results apply to maximum exercise performance (i.e., cardiorespiratory fitness) as well as to doses of vigorous exercise (metabolic equivalents >6) remains to be determined.

Objective: Assess whether the cross‐sectional relationships of BMI to cardiorespiratory fitness and vigorous activity are explained by BMI prior to exercising.

Methods and Procedures: Cross‐sectional study of the relationships between cardiorespiratory fitness (running speed during 10 km foot race) and vigorous physical activity (weekly running distance) to current BMI (BMIcurrent) and BMI at the start of running (BMIstarting) in 44,370 male and 25,252 female participants of the National Runners' Health Study.

Results: BMIstarting accounted entirely for the association between fitness and BMIcurrent in both sexes, but only a quarter of the association between vigorous physical activity levels and BMIcurrent in men. In women, BMIstarting accounted for 58% of the association between BMIcurrent and vigorous activity levels.

Discussion: Self‐selection based on pre‐exercise BMI accounts entirely for the association found between fitness and BMI (and possibly a portion of other health outcomes).
Relation of Epicardial Fat and Alanine Aminotransferase in Subjects With Increased Visceral Fat
Authors: Iacobellis Gianluca , Pellicelli Adriano M. , Grisorio Benvenuto , Barbarini Giorgio , Leonetti Frida , Sharma Arya M. , Barbaro Giuseppe
Published: January 2008

Background: Increased visceral adipose tissue (VAT) is a risk factor for an unfavorable cardio‐metabolic profile and fatty liver. Individuals with human immunodeficiency virus (HIV) on highly active antiretroviral therapy (HAART) can be associated with metabolic syndrome (MS) and higher visceral fat. However, the potential link between cardiac adiposity, emerging index of visceral adiposity, and fatty liver is still unexplored.

Objective: To evaluate whether echocardiographic epicardial adipose tissue, index of cardiac adiposity, could be related to serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, surrogate markers of fatty liver, in HIV‐infected patients with (HIV+MS+) and without HAART‐associated MS (HIV+MS‐).

Methods and Procedures: This was a cross‐sectional observational study on 57 HIV+MS+ patients, 52 HIV+MS− and 57 HIV‐negative subjects with MS (HIV−MS+), as control group. Epicardial fat thickness and intra‐abdominal VAT were obtained by echocardiography and magnetic resonance imaging (MRI), respectively. Serum ALT and AST activity, plasma adiponectin levels, and MS biochemical parameters were measured.

Results: Echocardiographic epicardial fat thickness was correlated with MRI‐VAT (r = 0.83, P < 0.01), AST/ALT ratio (r = 0.77, P < 0.01), ALT (r = 0.58, P < 0.01), AST (r = 0.56, P < 0.01), and adiponectin (r = −0.45, P < 0.01) in HIV+MS+. MRI‐VAT and AST/ALT ratio were the best correlates of epicardial fat thickness (r 2 = 0.45, P < 0.01).

Discussion: This study shows for the first time a clear relationship of epicardial fat, index of cardiac and visceral adiposity, and serum ALT and AST activity, markers of fatty liver, in subjects with increased visceral adiposity and cardio‐metabolic risk. This correlation seems to be independent of overall adiposity and rather function of excess visceral adiposity.
BMI and Health Status Among Adults With Asthma
Authors: Vortmann Michael , Eisner Mark D.
Published: January 2008

Background: A convincing body of literature links obesity with a higher risk for developing adult‐onset asthma. The impact of obesity on asthma severity among adults with pre‐existing asthma, however, is less clear.

Methods and Procedures: In a prospective cohort study of 843 adults with severe asthma, we studied the impact of BMI on asthma health status.

Results: The prevalence of obesity and overweight were 44% (95% confidence interval (CI) 41–47%) and 28% (95% CI 25–32%). The obese BMI group was associated with a higher risk for daily or near daily asthma symptoms than was the normal BMI group (odds ratio (OR) 1.81; 95% CI 1.10–2.96). Compared to the normal BMI group, generic physical health status was worse in the overweight (mean score decrement −2.42 points; 95% CI −4.39 to −0.45) and the obese groups (−6.31 points; 95% CI −8.14 to −4.49). Asthma‐specific quality of life was worse in the underweight (mean score increment 8.66 points; 95% CI 2.53–14.8) and obese groups (4.51 points; 95% CI 2.21–6.81), compared to those with normal BMI. Obese persons also had a higher number of restricted activity days that past month (5.05 days; 95% CI 2.90–7.19 days).

Discussion: It appears that obesity has a substantive negative effect on health status among adults with asthma. Further work is needed to clarify the precise mechanisms. Clinicians should counsel dietary modification and weight loss for their overweight and obese patients with asthma.
Restoration of Acute Insulin Response in T2DM Subjects 1 Month After Biliopancreatic Diversion
Authors: Briatore Lucia , Salani Barbara , Andraghetti Gabriella , Danovaro Cristina , Sferrazzo Elsa , Scopinaro Nicola , Adami Gian F. , Maggi Davide , Cordera Renzo
Published: January 2008

Objective: Biliopancreatic diversion (BPD) restores normal glucose tolerance in a few weeks in morbid obese subjects with type 2 diabetes, improving insulin sensitivity. However, there is less known about the effects of BPD on insulin secretion. We tested the early effects of BPD on insulin secretion in obese subjects with and without type 2 diabetes.

Methods and Procedures: Twenty‐one consecutive morbid obese subjects, 9 with type 2 diabetes (T2DM) and 12 with normal fasting glucose (NFG) were evaluated, just before and 1 month after BPD, by measuring body weight (BW), glucose, adipocitokines, homeostasis model assessment of insulin resistance (HOMA‐IR), acute insulin response (AIR) to e.v. glucose and the insulinogenic index adjusted for insulin resistance ([ΔI5/ΔG5]/HOMA‐IR).

Results: Preoperatively, those with T2DM differed from those with NFG in showing higher levels of fasting glucose, reduced AIR (57.9 ± 29.5 vs. 644.9 ± 143.1 pmol/l, P < 0.01) and reduced adjusted insulinogenic index (1.0 ± 0.5 vs. 17.6 ± 3.9 1/mmol2, P < 0.001). One month following BPD, in both groups BW was reduced (by ∼11%), but all subjects were still severely obese; HOMA‐IR and leptin decreased significanlty, while high‐molecular weight (HMW) adiponectin and adjusted insulinogenic index increased. In the T2DM group, fasting glucose returned to non‐diabetic values. AIR did not change in the NFG group, while in the T2DM group it showed a significant increase (from 58.0 ± 29.5 to 273.8 ± 47.2 pmol/l, P < 0.01). In the T2DM group, the AIR percentage variation from baseline was significantly related to changes in fasting glucose (r = 0.70, P = 0.02), suggesting an important relationship exists between impaired AIR and hyperglycaemia.

Discussion: BPD is able to restore AIR in T2DM even just 1 month after surgery. AIR restoration is associated with normalization of fasting glucose concentrations.
NLRX1 is a mitochondrial NOD‐like receptor that amplifies NF‐κB and JNK pathways by inducing reactive oxygen species production
Authors: Tattoli Ivan , Carneiro Leticia A , Jéhanno Muguette , Magalhaes Joao G , Shu Youmin , Philpott Dana J , Arnoult Damien , Girardin Stephen E
Published: January 2008

NOD‐like receptors (NLRs) are a family of intracellular sensors of microbial‐ or danger‐associated molecular patterns. Here, we report the identification of NLRX1, which is a new member of the NLR family that localizes to the mitochondria. NLRX1 alone failed to trigger most of the common signalling pathways, including nuclear factor‐κB (NF)‐κB‐ and type I interferon‐dependent cascades, but could potently trigger the generation of reactive oxygen species (ROS). Importantly, NLRX1 synergistically potentiated ROS production induced by tumour necrosis factor α, Shigella infection and double‐stranded RNA, resulting in amplified NF‐κB‐dependent and JUN amino‐terminal kinases‐dependent signalling. Together, these results identify NLRX1 as a NLR that contributes to the link between ROS generation at the mitochondria and innate immune responses.
BRC‐1 acts in the inter‐sister pathway of meiotic double‐strand break repair
Authors: Adamo Adele , Montemauri Paolo , Silva Nicola , Ward Jordan D , Boulton Simon J , La Volpe Adriana
Published: January 2008

The breast and ovarian cancer susceptibility protein BRCA1 is evolutionarily conserved and functions in DNA double‐strand break (DSB) repair through homologous recombination, but its role in meiosis is poorly understood. By using genetic analysis, we investigated the role of the Caenorhabditis elegans BRCA1 orthologue (brc‐1) during meiotic prophase. The null mutant in the brc‐1 gene is viable, fertile and shows the wild‐type complement of six bivalents in most diakinetic nuclei, which is indicative of successful crossover recombination. However, brc‐1 mutants show an abnormal increase in apoptosis and RAD‐51 foci at pachytene that are abolished by loss of spo‐11 function, suggesting a defect in meiosis rather than during premeiotic DNA replication. In genetic backgrounds in which chiasma formation is abrogated, such as him‐14/MSH4 and syp‐2, loss of brc‐1 leads to chromosome fragmentation suggesting that brc‐1 is dispensable for crossing over but essential for DSB repair through inter‐sister recombination.
A multiscale model for kinetics of formation and disintegration of spherical micelles
Authors: Mohan Gunjan , Kopelevich Dmitry I.
Published: January 2008

Dynamics of self-assembly and structural transitions in surfactant systems often involve a large span of length and time scales. A comprehensive understanding of these processes requires development of models connecting phenomena taking place on different scales. In this paper, we develop a multiscale model for formation and disintegration of spherical nonionic micelles. The study is performed under the assumption that the dominant mechanism of micelle formation (disintegration) is a stepwise addition (removal) of single monomers to (from) a surfactant aggregate. Different scales of these processes are investigated using a combination of coarse-grained molecular dynamics simulations, analytical and numerical solution of stochastic differential equations, and a numerical solution of kinetic equations. The removal of a surfactant from an aggregate is modeled by a Langevin equation for a single reaction coordinate, the distance between the centers of mass of the surfactant and the aggregate, with parameters obtained from a series of constrained molecular dynamics simulations. We demonstrate that the reverse process of addition of a surfactant molecule to an aggregate involves at least two additional degrees of freedom, orientation of the surfactant molecule and micellar microstructure. These additional degrees of freedom play an active role in the monomer addition process and neglecting their contribution leads to qualitative discrepancies in predicted surfactant addition rates. We propose a stochastic model for the monomer addition which takes the two additional degrees of freedom into account and extracts the model parameters from molecular dynamics simulations. The surfactant addition rates are determined from Brownian dynamics simulations of this model. The obtained addition and removal rates are then incorporated into the kinetic model of micellar formation and disintegration.
Phase separations in liquid crystal-colloid mixtures
Authors: Matsuyama Akihiko , Hirashima Ryota
Published: January 2008

We present a mean-field theory to describe phase separations in mixtures of a nematic liquid crystal and a colloidal particle. The theory takes into account an orientational ordering of liquid crystals and a crystalline ordering of colloidal particles. We calculate phase diagrams on the temperature-concentration plane, depending on interactions between a liquid crystal and a colloidal surface and a coupling between nematic and crystalline ordering. We find various phase separation processes, such as a nematic-crystal phase separation and nematic-isotropic-crystal triple point. Inside binodal curves, we find new unstable and metastable regions which are important in phase ordering dynamics. We also find a stable nematic-crystalline (NC) phase, where colloidal particles dispersed in a nematic phase can form a crystalline structure. The coexistence between two NC phases with different concentrations can be appear though the coupling between nematic and crystalline ordering.
Improvement of magnetic property of L1-FePt film by FePt∕Au multilayer structure
Authors: Feng Chun , Li Bao-He , Liu Yang , Teng Jiao , Li Ming-Hua , Jiang Yong , Yu Guang-Hua
Published: January 2008

We have prepared L10-FePt films by sputtering FePt∕Au mutilayers on glass substrates followed by a vacuum annealing process. The magnetic measurement and x-ray diffraction indicate that the ordering temperature of the FePt films is reduced to 350°C and the coercivity (HC) is greatly enhanced by using the FePt∕Au multilayer structure. The interface energy and the stress energy due to the misfit between FePt and Au crystal lattices provide extra driving force to the ordering process of FePt films. Additionally, partial Au atoms are supposed to diffuse to the FePt grain boundaries during annealing, which consequently pins the magnetic domain wall and leads to the high HC.
The electron beam hole drilling of silicon nitride thin films
Authors: Howitt D. G. , Chen S. J. , Gierhart B. C. , Smith R. L. , Collins S. D.
Published: January 2008

The mechanism by which an intense electron beam can produce holes in thin films of silicon nitride has been investigated using a combination of in situ electron energy loss spectrometry and electron microscopy imaging. A brief review of electron beam interactions that lead to material loss in different materials is also presented. The loss of nitrogen and silicon decreases with decreasing beam energy and although still observable at a beam energy of 150keV ceases completely at 120keV. The linear behavior of the loss rate coupled with the energy dependency indicates that the process is primarily one of direct displacement, involving the sputtering of atoms from the back surface of the specimen with the rate controlling mechanism being the loss of nitrogen.
Micromagnetostrictive vibrator using a U-shaped core of iron-gallium alloy (Galfenol)
Authors: Ueno T. , Higuchi T. , Saito C. , Imaizumi N. , Wun-Fogle M.
Published: January 2008

A micromagnetostrictive vibrator using a U-shaped core made of iron-gallium alloy (Galfenol) was investigated. The vibrator consists of a Galfenol core, with a 1mm2 cross section, a length of 5.8mm, and a 0.3mm separation between the prongs of the “U,” driving coils, and an iron yoke to close the magnetic loop. The Galfenol vibrator is superior to the PZT type in its high mechanical strength, low drive voltage requirements, and wide temperature operating range, and compared to our previous cylindrical type vibrator has a simpler construction and higher bandwidth. A displacement of 1.2μm (220ppm) was verified for the prototype with a 5.8mm long Galfenol core; the high magnetostriction >200ppm is inherited from the stress-annealed Galfenol. The displacement was also maintained under a 21MPa tensile stress (1.5kg hanging weight). Incorporation of a Nd–B–Fe magnet into the magnetic circuit successfully shifted the operating point to the linear portion of the magnetostrictive curves. This biasing effect is useful in reducing the drive voltage.
Photodetachment of the hydrogen negative ion in weakly coupled plasmas
Authors: Kar Sabyasachi , Ho Y. K.
Published: January 2008

The effect of weakly coupled plasmas on photodetachment cross sections of the hydrogen negative ion is investigated by using the asymptotic from of the bound state wave function and a plane wave form for the final-state wave function. The Debye model is used to represent the plasma effects. The required normalization constant is determined from highly accurate, completely nonadiabatic wave functions for the three-particle systems. Photodetachment cross sections for the plasma-embedded H− ion are calculated for different Debye lengths (D) ranging from infinite (pure Coulomb) to D=1.0.
Dynamic viscous permeability of an open-cell aluminum foam: Computations versus experiments
Authors: Perrot Camille , Chevillotte Fabien , Panneton Raymond
Published: January 2008

Is it possible to find a two-dimensional (2D) periodic unit cell representative of the dynamic viscous dissipation properties of a real porous media? This is a challenging question addressed in this paper through a review of tools and methods of experimental and computational micro(poro)mechanics. The combination of advanced experimental imaging and numerical homogenization techniques provides a unique opportunity to understand and assess the limits of two-dimensional models of microstructures, as a potential basis for the engineering prediction of macroscopic properties of acoustical materials. This is illustrated for a real sample of open-cell aluminum foam. The conclusion, based on this analysis, is that the 2D periodic foam model geometry provides a reliable estimate of the dynamic permeability, except in the low frequency range. This is not surprising because in the 2D periodic foam model geometry, ligaments are always perpendicular to the flow direction, thus decreasing artificially the static permeability of the viscous flow.
On the effects of double-step anneal treatments on light emission from Er-doped Si-rich silicon oxide
Authors: Heng C. L. , Zalloum O. H. Y. , Wojcik J. , Roschuk T. , Mascher P.
Published: January 2008

We have studied photoluminescence (PL) from an Er-doped Si-rich Si oxide (SRSO) film thermally annealed under different conditions. Compared to the case of annealing in N2 alone, double-step annealing the film at 875°C in N2 and then at ∼850°C in O2 or vice versa increases Er PL intensities by 10%–15%; while double-step annealing in N2+5%H2 (FG) and then in O2 or vice versa yields significant enhancements of the PL from the SRSO matrix and the Er PL intensity decreases differently by exchanging the processing order. Fourier transform infrared spectroscopy indicates that silicon oxynitride forms after annealing in FG ambient, and for the samples initially oxidized, the increase of Er PL intensity after secondary annealing in N2 (or FG) is due to more Si nanoclusters being formed. The PL spectra exhibit different annealing behavior with increasing the FG annealing temperature and the processing order. Weak oxygen bonds and silicon oxynitrides are believed to form upon O2 and FG annealing, respectively, and play important roles in the PL.
Discrete contact continuous film magnetoresistive biosensor
Authors: Zhou Yuchen
Published: January 2008

This paper describes a magnetic biosensor having continuous magnetoresistance film stack with discrete nonmagnetic contact pads. Detection unit is defined by a pair of contact pads. With contact pad miniaturization not limited by magnetic degradation and sensitivity variation as in patterned magnetic films, submicron spatial resolution can be achieved. Semicontinuous differential waveform can be generated with sequential readout of the detection units and the bead presence is detected by pulse pattern recognition. Methods to align the magnetic labeled entities toward the highest sensitivity region of the continuous biosensor with external field gradient and physical confinement are discussed.
First-order reversal curve diagrams of magnetic entities with mean interaction field: A physical analysis perspective
Authors: Béron Fanny , Ménard David , Yelon Arthur
Published: January 2008

A new approach to the quantitative and physical analysis of first-order reversal curve (FORC) diagrams is presented. Each hysteron in the FORC method represents a magnetic cluster. Starting with a model for a ferromagnetic, isotropic, and monodomain sphere, and adding anisotropy and domain structure, three different types of “basic hysterons” are obtained: vertical reversible and irreversible, and linear. The FORC diagrams of basic hysterons with a mean interaction field were obtained by simulation. From them, the relationships between the characteristics of the hysterons and the FORC distribution function were extracted. Different sets of hysterons can lead to the same FORC distribution function. A positive mean interaction field tends to merge the hysterons on the FORC diagram, while a negative mean interaction field introduces repulsion between them.
Dynamical properties of spherical ferromagnetic nanoparticles
Authors: Nguyen Hoa T. , Cottam M. G.
Published: January 2008

Calculations are presented for the dipole-exchange spin waves in spherical ferromagnetic nanoparticles such as solid spheres, part spheres, and spherical shells using a microscopic (or Hamiltonian-based) method. The magnetic dipolar and exchange interactions are incorporated, as well as a Zeeman term for an external magnetic field. The theory is particularly convenient, by contrast with macroscopic theories, for describing the dynamics of inhomogeneously magnetized samples, and it avoids using phenomenological boundary conditions. The Green’s function method yields results for the frequencies, spatial distribution, and spectral intensities of the spin waves. Applications are made to Fe19Ni81 and Co80Ni20 nanoparticles with diameters in the range of 10–100nm. The mode-mixing (hybridization) effects on the spin-wave branches are shown to be important.
Electrical, structural, and chemical properties of semiconducting metal oxide nanofiber yarns
Authors: Lotus A. F. , Bender E. T. , Evans E. A. , Ramsier R. D. , Reneker D. H. , Chase G. G.
Published: January 2008

The electrical, structural, and chemical properties of twisted yarns of metal-oxide nanofibers, fabricated using a modified electrospinning technique, are investigated in this report. In particular, synthesized zinc oxide and nickel oxide yarns having diameters in the range of 4–40μm and lengths up to 10cm were characterized, whose constituent nanofibers had average diameters of 60–100nm. These yarns have one macroscopic dimension for handling while retaining some of the properties of nanofibers.
Large eddy simulation of magnetohydrodynamic turbulent duct flows
Authors: Kobayashi Hiromichi
Published: January 2008

Turbulent duct flows in a uniform magnetic field are examined at low magnetic Reynolds number. Large-eddy simulation is conducted to reveal a sidewall effect on the skin friction. The duct has a square cross section and entirely insulated walls. The duct flow has two kinds of boundary layers: Hartmann layer and sidewall layer. The Hartmann layer is located on the wall perpendicular to the magnetic field, while the sidewall layer exists on the wall parallel to the magnetic field. As the magnetic field increases in the range of turbulent flows, the Hartmann layer becomes thin because of the “Hartmann flattening”—a flattening effect of the flow by the Lorentz force. The sidewall layer, however, becomes thick because of the turbulence suppression until the laminarization takes place. When the Reynolds number, Re, based on the hydraulic diameter, molecular viscosity, and bulk velocity is 5 300, the Hartmann and sidewall layers are laminarized at the same Hartmann number that is proportional to the magnetic field. When the Hartmann layer is laminarized at Re=29 000, the sidewall layer remains turbulence. This is due to a sidewall effect and is the condition that a local maximum takes place in the skin friction profile. When the sidewall layer is laminarized, the flow totally becomes laminar and the skin friction becomes minimum.
Additional stress-induced band gap narrowing in a silicon die
Authors: Furuhashi Masayuki , Taniguchi Kenji
Published: January 2008

Semiconductor devices have intrinsic mechanical stress due to two separate sources, silicon wafer processing and packaging. This intrinsic stress induces band gap narrowing and consequent degradation of device reliability. In this work, a silicon die that included shallow trench isolation structures was used with additional external compression to clarify the interaction effects on band gap narrowing between stresses induced by different factors. It was observed that the pressure coefficient due to the additional external compression is linearly dependent on the intrinsic tensile region/total region ratio of a p-n diode.
Dual-synthetic antiferromagnet and its effect on giant magnetoresistance
Authors: Bao Jin , Xu Xiao-Guang , Liu Quan-Lin , Pan Li-Qing , Yu Guang-Hua , Jiang Yong , Jalil M. B. A.
Published: January 2008

A dual-synthetic antiferromagnet (DSyAF) structure of Co90Fe10∕Ru∕Co90Fe10∕Ru∕Co90Fe10 is studied. Compared with a conventional synthetic antiferromagnet (SyAF) of Co90Fe10∕Ru∕Co90Fe10, the DSyAF has higher saturation magnetic field and lower saturation magnetization. Moreover, the DSyAF shows good thermal stability after annealing at 300°C for 1h. We also fabricate current-in-plane spin valves with the SyAF or the DSyAF as the pinned layer and demonstrate that using the DSyAF as a pinned layer enhances giant magnetoresistance at room temperature.
Structural and magneto-optical properties of FeRh thin films
Authors: Inoue Sho , Phuoc Nguyen N. , Cao Jiangwei , Nam Nguyen T. , Ko Hnin Yu Yu , Suzuki Takao
Published: January 2008

A systematic investigation of the magneto-optical properties in conjunction with structure and magnetic properties of FeRh thin films epitaxially deposited onto MgO(100) substrates by rf sputter-deposition system was performed. The result, for the first time, shows a (negative) maximum peak of Kerr rotation at around 3.8eV when FeRh thin films are in ferromagnetic state. The polar Kerr rotation angle is found to increase at temperatures above 100°C, which corresponds to the antiferromagnetic-ferromagnetic transition of FeRh thin films.
A potential nuclear envelope-targeting domain and an arginine-rich RNA binding element identified in the putative movement protein of the GAV strain of Barley yellow dwarf virus
Authors: Xia Zongliang , Wang Yan , Du Zhiqiang , Li Junmin , Zhao Richard Y. , Wang Daowen
Published: January 2008

In this study, the structural elements in the putative movement protein (MP) of the GAV strain of Barley yellow dwarf virus (BYDV-GAV) were investigated. The GFP fusion protein of BYDV-GAV MP was found to be associated with the nuclear envelope (NE) in transgenic Arabidopsis thaliana (L.) cells. Serial deletion mapping demonstrated that the predicted α-helical domain located at the N-terminus of BYDV-GAV MP was required and sufficient for NE targeting in onion epidermal cells. This α-helical domain does not contain any sequence elements similar to known nuclear localisation signals or bear any significant resemblance to previously characterised NE-targeting structure, indicating that it may represent a novel NE-targeting domain in plant cells. Deletion mutagenesis showed that the C-terminal end of BYDV-GAV MP possessed an element required for its RNA binding activity in vitro. Further analysis revealed that the arginine amino acids within the last 11 residues of the C-terminal end were crucial for the binding of BYDV-GAV MP to RNA. This C-terminal element enriched in basic residues was also present in the MPs of other BYDV strains and the polerovirus Potato leaf roll virus (PLRV), suggesting the conservation of a RNA binding element in the MPs from both luteoviruses and poleroviruses. The data in this work present an initial characterisation of a novel plant NE-targeting domain and a RNA binding element on BYDV-GAV MP. Further studies are underway to investigate the function of these elements in the biology of natural BYDV-GAV infection.