bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis and correction of gradient nonlinearity bias in apparent diffusion coefficient measurements
Authors: Malyarenko Dariya I. , Ross Brian D. , Chenevert Thomas L. 
Published: May 2013

PurposeGradient nonlinearity of MRI systems leads to spatially dependent b‐values and consequently high non‐uniformity errors (10–20%) in apparent diffusion coefficient (ADC) measurements over clinically relevant field‐of‐views. This work seeks practical correction procedure that effectively reduces observed ADC bias for media of arbitrary anisotropy in the fewest measurements.MethodsAll‐inclusive bias analysis considers spatial and time‐domain cross‐terms for diffusion and imaging gradients. The proposed correction is based on rotation of the gradient nonlinearity tensor into the diffusion gradient frame where spatial bias of b‐matrix can be approximated by its Euclidean norm. Correction efficiency of the proposed procedure is numerically evaluated for a range of model diffusion tensor anisotropies and orientations.ResultsSpatial dependence of nonlinearity correction terms accounts for the bulk (75–95%) of ADC bias for FA = 0.3–0.9. Residual ADC non‐uniformity errors are amplified for anisotropic diffusion. This approximation obviates need for full diffusion tensor measurement and diagonalization to derive a corrected ADC. Practical scenarios are outlined for implementation of the correction on clinical MRI systems.ConclusionsThe proposed simplified correction algorithm appears sufficient to control ADC non‐uniformity errors in clinical studies using three orthogonal diffusion measurements. The most efficient reduction of ADC bias for anisotropic medium is achieved with non‐lab‐based diffusion gradients. Magn Reson Med 71:1312–1323, 2014. © 2013 Wiley Periodicals, Inc.
Mapping mean and fluctuating velocities by Bayesian multipoint MR velocity encoding‐validation against 3D particle tracking velocimetry
Authors: Knobloch Verena , Binter Christian , Gülan Utku , Sigfridsson Andreas , Holzner Markus , Lüthi Beat , Kozerke Sebastian 
Published: May 2013

PurposeTo validate Bayesian multipoint MR velocity encoding against particle tracking velocimetry for measuring velocity vector fields and fluctuating velocities in a realistic aortic model.MethodsAn elastic cast of a human aortic arch equipped with an 80 or 64% stenotic section was driven by a pulsatile pump. Peak velocities and peak turbulent kinetic energies of more than 3 m/s and 1000 J/m3 could be generated. Velocity vector fields and fluctuating velocities were assessed using Bayesian multipoint MR velocity encoding with varying numbers of velocity encoding points and particle tracking velocimetry in the ascending aorta.ResultsVelocities and turbulent kinetic energies measured with 5‐fold k‐t undersampled 10‐point MR velocity encoding and particle tracking velocimetry were found to reveal good correlation with mean differences of −4.8 ± 13.3 cm/s and r2 = 0.98 for velocities and −21.8 ± 53.9 J/m3 and r2 = 0.98 for turbulent kinetic energies, respectively. Three‐dimensional velocity patterns of fast flow downstream of the stenoses and regions of elevated velocity fluctuations were found to agree well.ConclusionAccelerated Bayesian multipoint MR velocity encoding has been demonstrated to be accurate for assessing mean and fluctuating velocities against the reference standard particle tracking velocimetry. The MR method holds considerable potential to map velocity vector fields and turbulent kinetic energies in clinically feasible exam times of <15 min. Magn Reson Med 71:1405–1415, 2014. © 2013 Wiley Periodicals, Inc.
Involvement of cathepsins B and L in inflammation and cholesterol trafficking protein NPC2 secretion in macrophages
Authors: Hannaford Jennifer , Guo Hong , Chen Xiaoli 
Published: May 2013

ObjectiveObesity and its related chronic inflammation are the major risk factors for developing metabolic disturbances. The roles of cathepsin cysteine proteases have been tied to inflammation and atherosclerosis. Cathepsins are important functional links between inflammation, cholesterol metabolism, and atherosclerosis in obesity. NPC2, a lysosomal protein, plays an important role in cholesterol trafficking. The objective of this study was to examine the regulation of cathepsins and NPC2 in adipose tissue and macrophages in obesity and the effect of modifying cathepsin activity in cholesterol metabolism and trafficking in macrophages.Design and MethodsCathepsins and NPC2 mRNA expression and protein secretion were detected in obese adipose tissue as well as 3T3‐L1 adipocytes and Raw 264.7 macrophages in response to inflammatory stimuli and cathepsin inhibitors.ResultsIt was found that high‐fat diet feeding altered the mRNA and protein expression levels of cathepsins B and L (CtB and CtL) and NPC2 in adipose tissue in mice; the differential regulation of these proteins was observed between adipose depots. In vitro studies showed that TNF‐α reduces intracellular protein levels of CtB, CtL, and NPC2, but increases their secretion in 3T3‐L1 adipocytes. Likewise, LPS stimulated the secretion of CtB and NPC2 in Raw 264.7 macrophages. Using the inhibitors of cathepsin enzymatic activity, it was found that CtB and CtL regulate TNF‐α production, the expression and secretion of NPC2 protein, and the mRNA levels of the genes involved in cholesterol trafficking in macrophages.ConclusionThese findings suggest that CtB and CtL have a significant involvement in mediating the inflammatory response, in cholesterol trafficking, and in regulating NPC2 secretion.
Pro12Ala variant of the PPARG2 gene increases body mass index: An updated meta‐analysis encompassing 49,092 subjects
Authors: Galbete C. , Toledo E. , Martínez‐González M.A. , Martínez J.A. , Guillén‐Grima F. , Marti A. 
Published: May 2013

ObjectiveThe peroxisome proliferator‐activated receptor gamma 2 (PPARG2) gene has been intensively studied with relation to obesity and metabolic disorders. Indeed, a large number of studies assessing the association between the PPARG2 polymorphism Pro12Ala (rs1801282) and body mass index (BMI) have been published with some controversial results. In this meta‐analysis, the effects of Pro12Ala polymorphism of the PPARG2 gene on BMI were investigated.Design and MethodsExternally published data were collected and we included our own novel data from a study in the elderly participants (>55 years) of a Mediterranean cohort, the SUN (“Seguimiento Universidad de Navarra”) Project (n = 972). A total of 75 independent studies with 49,092 subjects (39,806 with the genotype Pro12Pro and 9,286 carrier subjects of the Ala allele) were included.ResultsThe meta‐analysis revealed a higher BMI with an overall estimation of +0.065 kg/m2 (95%CI = 0.026‐0.103, P = 0.001) for homo‐/heterozygous carriers of the Ala allele of the PPARG2 gene in comparison to non‐carriers. The analysis also showed that there was heterogeneity (P for heterogeneity <0.001), but funnel plots did not suggest apparent publication bias. Furthermore, the association between the Pro12Ala polymorphism of the PPARG2 gene and increased BMI was stronger in Caucasian. Thus, carriers of the Ala allele had significantly higher BMI than non‐carriers in a subsample of 6,528 Caucasian male subjects (standardized mean difference = 0.090, 95%CI=0.032‐0.148, P = 0.002, P for heterogeneity = 0.121).ConclusionThis updated meta‐analysis showed that carriers of the Ala12 allele of the PPARG2 gene had a higher average BMI.
Advantages of percent weight loss as a method of reporting weight loss after Roux‐en‐Y gastric bypass
Authors: Hatoum Ida J. , Kaplan Lee M. 
Published: May 2013

ObjectiveAlthough Roux‐en‐Y gastric bypass (RYGB) is an effective treatment for severe obesity, weight loss (WL) after this operation is highly variable. Accurate predictors of outcome would thus be useful in identifying those patients who would most benefit from this invasive therapy. WL has been characterized using several different metrics, including the number of BMI units lost (ΔBMI), percent baseline WL (%WL), and percent excess body WL (%EBWL). To identify clinically relevant predictors most sensitively, it is necessary to avoid confounding by other factors, including preoperative BMI (pBMI), the strongest known predictor of RYGB‐induced WL.Design and MethodsTo determine the WL measure least associated with pBMI, outcomes of 846 patients undergoing RYGB were analyzed.ResultsPatients in this cohort had an average pBMI of 50.0 kg/m2 at baseline. At weight nadir, they lost an average 19.4 kg/m2, 38.7% WL, and 81.2% EBWL. pBMI was strongly and positively associated with ΔBMI at both 1 year (r = 0.56, P = 4.7 × 10−51) and nadir (r = 0.58, P = 2.8 × 10−77) and strongly but negatively associated with %EBWL at 1 year (r = −0.52, P = 3.8 × 10−44) and nadir (r = −0.45, P = 7.2×10−43). In contrast, pBMI was not significantly associated with %WL at 1 year (r = 0.04, P = 0.33) and only weakly associated at nadir (r = 0.13, P = 0.0002).ConclusionsOf the metrics examined, %WL is the parameter describing WL after RYGB least influenced by pBMI. It thus improves comparison of WL outcomes across studies of patients undergoing surgery and facilitates the most sensitive identification of novel predictors of surgery‐induced WL. We therefore is recommend that %WL be adopted more broadly in reporting weight loss after RYGB.
Pharmacological inhibition of diacylglycerol acyltransferase 1 reduces body weight and modulates gut peptide release—Potential insight into mechanism of action
Authors: Liu Jinqi , Gorski Judith N. , Gold Stephen J. , Chen Dunlu , Chen Shirley , Forrest Gail , Itoh Yoshiki , Marsh Donald J. , McLaren David G. , Shen Zhu , Sonatore Lisa , Carballo‐Jane Ester , Craw Stephanie , Guan Xiaoming , Karanam Bindhu , Sakaki Junichi , Szeto Daphne , Tong Xinchun , Xiao Jianying , Yoshimoto Ryo , Yu Hong , Roddy Thomas P. , Balkovec James , Pinto Shirly 
Published: May 2013

ObjectiveInvestigation was conducted to understand the mechanism of action of diacylglycerol acyltransferase 1 (DGAT1) using small molecules DGAT1 inhibitors, compounds K and L.Design and MethodsBiochemical and stable‐label tracer approaches were applied to interrogate the functional activities of compounds K and L on TG synthesis and changes of carbon flow. Energy homeostasis and gut peptide release upon DGAT1 inhibition was conducted in mouse and dog models.ResultsCompounds K and L, dose‐dependently inhibits post‐prandial TG excursion in mouse and dog models. Weight loss studies in WT and Dgat1‐/‐ mice, confirmed that the effects of compound K on body weight loss is mechanism‐based. Compounds K and L altered incretin peptide release following oral fat challenge. Immunohistochemical studies with intestinal tissues demonstrate lack of detectable DGAT1 immunoreactivity in enteroendocrine cells. Furthermore, 13C‐fatty acid tracing studies indicate that compound K inhibition of DGAT1 increased the production of phosphatidyl choline (PC).ConclusionTreatment with DGAT1 inhibitors improves lipid metabolism and body weight. DGAT1 inhibition leads to enhanced PC production via alternative carbon channeling. Immunohistological studies suggest that DGAT1 inhibitor's effects on plasma gut peptide levels are likely via an indirect mechanism. Overall these data indicate a translational potential towards the clinic.
Ectopic fat and adipokines in metabolically benign overweight/obese women: The kronos early estrogen prevention study
Authors: Ogorodnikova Alexandra D. , Khan Unab I. , McGinn Aileen P. , Zeb Irfan , Budoff Matthew J. , Harman S.M. , Miller Virginia M. , Brinton Eliot A. , Manson JoAnn E. , Hodis Howard N. , Merriam George R. , Cedars Marcelle I. , Taylor Hugh S. , Naftolin Frederick , Lobo Rogerio A. , Santoro Nanette , Wildman Rachel P. 
Published: May 2013

ObjectiveIt is unclear why despite a comparable cardiometabolic risk profile, “metabolically benign” overweight/obese individuals show an elevated risk of cardiovascular disease compared to normal weight individuals.Design and MethodsIn cross‐sectional analyses, we compared levels of ectopic fat (epicardial, pericardial, and hepatic fat) and adipokines (leptin, soluble leptin receptor, and high molecular weight [HMW] adiponectin) among metabolically benign (MBO) and at‐risk overweight/obese (ARO), and metabolically benign normal weight (MBNW) women, screened for the Kronos Early Estrogen Prevention Study. We defined “metabolically benign” with ≤ 1, and “at‐risk” with ≥2 components of the metabolic syndrome.ResultsCompared to MBO women, ARO women had significantly elevated odds of being in the top tertile of epicardial fat (OR: 1.76, 95% CI: 1.04‐2.99), hepatic fat (OR: 1.90, 95% CI:1.12‐3.24) and leptin (OR: 2.15, 95% CI: 1.23‐3.76), and the bottom tertile of HMW‐adiponectin (OR: 2.90, 95% CI: 1.62‐5.19). Compared to MBNW women, MBO women had significantly higher odds of being in the top tertile of epicardial fat (OR: 5.17, 95% CI: 3.22‐8.29), pericardial fat (OR: 9.27, 95% CI: 5.52‐15.56) and hepatic fat (OR: 2.72, 95% CI: 1.77‐4.19) and the bottom tertile of HMW adiponectin levels (OR: 2.51, 95% CI: 1.60‐3.94).ConclusionsLevels of ectopic fat and the adverse adipokine profile increase on a continuum of BMI, suggesting that the metabolically benign phenotype may be a transient state.
Laparoscopic sleeve gastrectomy differentially affects serum concentrations of FGF‐19 and FGF‐21 in morbidly obese subjects
Authors: Haluzíková D. , Lacinová Z. , Kaválková P. , Drápalová J. , Křížová J. , Bártlová M. , Mráz M. , Petr T. , Vítek L. , Kasalický M. , Haluzík M. 
Published: May 2013

ObjectiveFibroblast growth factor (FGF)‐19 and FGF‐21 are novel metabolic regulators that improve insulin resistance and obesity in rodents. The aim of the study was to assess the effects of laparoscopic sleeve gastrectomy (LSG) on serum concentrations of FGF‐19 and FGF‐21 along with circulating bile acids and other relevant hormonal and biochemical parameters.Design and MethodsSeventeen females with obesity undergoing LSG and 15 lean healthy females were included into the study. Anthropometric and biochemical parameters, serum concentrations of FGF‐19 and ‐21, insulin, adiponectin, leptin, C‐reactive protein, resistin, amylin (total), ghrelin (active), glucagon‐like peptide 1 (GLP‐1, active), glucose‐dependent insulinotropic peptide (GIP, total), peptide YY (PYY, total), pancreatic polypeptide (PP), and bile acids, and mRNA expression of selected adipokines and inflammatory markers in bioptic samples of subcutaneous fat were assessed at baseline and 6, 12, and 24 months after LSG.ResultsLSG markedly decreased body weight, BMI, waist circumference, and insulin levels and improved systemic inflammation and lipid levels. FGF‐19 concentrations increased and FGF‐21 concentrations decreased after LSG along with increased adiponectin and decreased leptin, amylin, and ghrelin levels. GLP‐1, GIP, PP, and circulating bile acids were not affected by LSG. PYY decreased significantly 24 months after surgery only. mRNA expression analysis in subcutaneous fat showed markedly reduced proinflammatory state.ConclusionsOur results indicate that increased FGF‐19 and decreased ghrelin concentrations could have partially contributed to the improvement of systemic inflammation and some metabolic parameters after LSG, while changes of FGF‐21 are rather secondary because of weight loss.
Metabolic and endocrine correlates of cognitive function in healthy young women
Authors: Bove R.M. , Brick D.J. , Healy B.C. , Mancuso S.M. , Gerweck A.V. , Bredella M.A. , Sherman J.C. , Miller K.K. 
Published: May 2013

ObjectiveObesity has been associated with cognitive decline in longitudinal studies of older individuals. We hypothesized that the cognitive sequelae of obesity may be detectable in the reproductive years. In addition, we explored the hypothesis that these associations may be mediated by the hormonal milieu.Design and MethodsOf 49 young healthy lean and overweight women aged 20‐45, we investigated the association between performance on a battery of cognitive tests, body composition parameters [body mass index, total fat, abdominal (visceral, subcutaneous, and total) adipose tissue, and muscle], and hormone levels (insulin, adiponectin, leptin, insulin‐like growth factor 1 (IGF‐1), estrogen, testosterone, and vitamin D).ResultsWe found a significant negative association between both visceral adiposity and muscle, and performance in the domain of verbal learning and memory, after controlling for age and education. Other body composition parameters showed similar trends (0.05 < P < 0.10). Additionally, the degree of insulin resistance was negatively associated with executive function domain. None of the associations between the other hormones examined (adipokines, IGF‐1, gonadal hormones, and vitamin D) and cognitive function were significant.ConclusionThese preliminary findings suggest a possible association between obesity and cognitive function in healthy young women of reproductive age. More research is warranted into the potential modulatory effect of insulin resistance on this association.
Microstructure and properties of styrene‐butadiene rubber based nanocomposites prepared from an aminosilane modified synthetic lamellar nanofiller
Authors: Dal Pont Kevin , Gérard Jean‐François , Espuche Eliane 
Published: May 2013

ABSTRACTIn this work, a novel nanocomposite series based on styrene‐butadiene rubber (SBR latex) and alpha‐zirconium phosphate(α‐ZrP) lamellar nanofillers is successfully prepared. The α‐ZrP lamellar filler is modified at the cation exchange capacity by γ‐aminopropyltrimethoxysilane and the filler surface modification is first discussed. A significant improvement of the mechanical properties is obtained by using the surface modified nanofillers. However, no modification of the gas barrier properties is observed. The impact of addition of bis(triethoxysilylpropyl)tetrasulfide (TESPT) as coupling agent in the system is discussed on the nanofiller dispersion state and on the filler–matrix interfacial bonding. Simultaneous use of modified nanofillers and TESPT coupling agent is found out with extraordinary reinforcing effects on both mechanical and gas barrier properties and the key factors at the origin of the improvement of these properties are identified. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1051–1059
Development of a label‐free LC‐MS/MS strategy to approach the identification of candidate protein biomarkers of disease recurrence in prostate cancer patients in a clinical trial of combined hormone and radiation therapy
Authors: Morrissey Brian , O'Shea Carmel , Armstrong John , Rooney Cathy , Staunton Lisa , Sheehan Martina , Shannon Aoife M. , Pennington Stephen R. 
Published: May 2013

PurposeCombined hormone and radiation therapy (CHRT) is one of the principle curative regimes for localised prostate cancer (PCa). Following treatment, many patients subsequently experience disease recurrence however; current diagnostics tests fail to predict the onset of disease recurrence. Biomarkers that address this issue would be of significant advantage.Experimental designLabel‐free LC‐MS/MS for protein biomarker discovery and MRM for targeted confirmation were applied to patient serum samples accrued in a non‐interventional clinical trial of CHRT.ResultsAnalysis of time‐matched patient samples from a patient with disease recurrence compared with a time match disease‐free individual supported the identification of 287 proteins. Of these, 141 proteins were quantified, 95 proteins changed in their expression (P ≤ 0.05 and ≥1.5‐fold change) and of these 16 were selected for MRM confirmation. The protein expression changes observed in the label‐free LC‐MS/MS and MRM analysis were found to be highly correlated (R2 = 0.85).Conclusions and clinical relevanceThe establishment of a clinical trial to support the acquisition of samples and development of a pipeline for MS‐based biomarker discovery and validation should contribute to the identification of a serum protein signature to predict or monitor the outcome of treatment of patients with PCa.
Electronic structures of ternary‐layered semiconductor TlGaSe2 investigated by photoemission spectroscopy
Authors: Motonami Satoru , Mimura Kojiro , Shim YongGu , Wakita Kazuki , Sato Hitoshi , Utsumi Yuki , Ueda Shigenori , Nakatake Masashi , Shimada Kenya , Taguchi Yukihiro , Kobayashi Keisuke , Namatame Hirofumi , Taniguchi Masaki , Orudzhev Guseyn , Mamedov Nazim 
Published: May 2013

AbstractElectronic structures of the ternary‐layered semiconductor TlGaSe2 have been investigated by hard and soft X‐ray photoemission spectroscopies (HAXPES and SXPES). The spectral shape of all core levels obtained from HAXPES and SXPES can be represented by a symmetric Lorentzian, reflecting the semiconducting nature of TlGaSe2. Peak positions of the same bulk components, obtained from HAXPES and SXPES, are almost the same. This suggests that the recoil effect is ignorable for TlGaSe2 and that the HAXPES spectra of this material provide us the information on the intrinsic bulk electronic structures. The valence‐band HAXPES spectrum is composed of two main features and is well reproduced by the theoretical calculation. The estimated value of 2.0 eV for the energy gap is consistent with the results from the optical measurements. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of Cu2SnS3 thin films by sulfurization of evaporated Cu‐Sn precursors for solar cells
Authors: Aihara Naoya , Araki Hideaki , Takeuchi Akiko , Jimbo Kazuo , Katagiri Hironori 
Published: May 2013

AbstractThe ternary compound semiconductor Cu2SnS3 (CTS) is formed from non‐toxic materials that are abundant in Earth's crust and other low‐cost elements. CTS has also been reported to a band gap energy range of 0.93–1.77 eV and an absorption coefficient of 1.0×104 cm–1. Consequently, CTS is a potential material for the p‐type absorber layer of thin film solar cells. In this study, we examined the dependence of the optical, electrical and photovoltaic properties of CTS thin films on the Cu/Sn composition ratio. CTS thin films were fabricated by sulfurizing evaporated Cu‐Sn precursors with different Cu/Sn composition ratios at 560 °C for 2 h in a N2 atmosphere and sulfur vapor. The Cu/Sn composition ratios of the sulfurized films were determined to be 1.6–2.5 by X‐ray fluorescence. The solar cell comprising a CTS thin film with a Cu/Sn composition ratio of 1.77 exhibited the best performance among the cells examined, an open‐circuit voltage of 242 mV, a short‐circuit current density of 28.9 mA/cm2, a fill factor of 41.7% and a conversion efficiency of 2.92% were obtained. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structures and band‐gap energies of Cu2Sn(S,Se)3 (0≤ x ≤1.0) solid solution
Authors: Nomura Takeshi , Maeda Tsuyoshi , Takei Kouji , Morihama Masaru , Wada Takahiro 
Published: May 2013

AbstractCu2Sn(S1–xSex)3 (CTSSe) solid solutions with 0 ≤ x ≤ 1.0 were synthesized by mixing the elemental powders and post‐annealing at 600 °C. The crystal structure of Cu2SnS3 (CTS), Cu2SnSe3 (CTSe), and their solid solution were determined by Rietveld refinement of the powder X‐ray diffraction data. CTSSe solid solution had a monoclinic crystal system [space group: Cc (No. 9)]. The refined lattice parameters of CTS were a =6.654(8) Å, b =11.534(2) Å, c =6.659(4) Å, and β =109.40(5)° and those of CTSe were a =6.964(6) Å, b =12.056(6) Å, c =6.972(4) Å, and β =109.49(1)°. The lattice parameters, a, b, and c of CTSSe solid solution monotonically increased with increasing Se content. The band gap of the CTSSe solid solution linearly decreased from 0.87 eV (x=0.0) to 0.67 eV (x=0.60) with increasing Se content. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)