bluuebunny/crossref_metadata_2025_split huggingface dataset:
The association between acanthosis nigricans and dysglycemia in an ethnically diverse group of eighth grade students
Authors: Rafalson Lisa , Pham Trang H. , Willi Steven M. , Marcus Marsha , Jessup Ann , Baranowski Tom 
Published: April 2013

AbstractObjective:The purpose of this study was to describe the prevalence of acanthosis nigricans (AN) and to quantify its association with dysglycemia in an ethnically diverse group of eighth‐grade students.Design and Methods:Data were collected in 2003 from a cross‐sectional study of students from 12 middle schools in three US states. Sex, race/ethnicity, and pubertal status were self‐reported. Anthropometric measures were recorded. Trained staff identified the presence and severity of AN by inspection of the back of the neck. Fasting and 2 h blood samples were analyzed for impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and high‐risk glycated hemoglobin (A1C), respectively, defined as ≥100 mg/dl, ≥140 mg/dl, and ≥ 5.7‐6.4%.Results:Overall, 25.0%, 58.2%, and 16.8% were Black, Hispanic, and White, respectively. AN was present among 406/1,438 (28.2%) of students: 39% among Black, 30% among Hispanic, and 5.4% among White. IGT and high‐risk A1C were present among 2.1%, and 12.4%, respectively. In multivariate logistic modeling after adjusting for gender, family history of diabetes, BMI percentile, and pubertal staging, the presence (vs. absence) of AN was associated with a 59% increased likelihood of high‐risk A1C: (P = 0.04), twice the likelihood of IGT (P = 0.06), and 47% greater likelihood of IGT/IFG combined (P < 0.0001). Adjustment for insulin attenuated the ORs by 25‐70%.Conclusion:In a racially/ethnically diverse sample of US adolescents, AN was common, occurring in 28% of the sample. AN was associated with a 50‐100% increased likelihood of dysglycemia even after consideration of established diabetes risk factors.
Accuracy of prediction scores and novel biomarkers for predicting nonalcoholic fatty liver disease in obese children
Authors: Koot Bart G.P. , van der Baan‐Slootweg Olga H. , Bohte Anneloes E. , Nederveen Aart J. , van Werven Jochem R. , Tamminga‐Smeulders Christine L.J. , Merkus Maruschka P. , Schaap Frank G. , Jansen Peter L.M. , Stoker Jaap , Benninga Marc A. 
Published: April 2013

AbstractBackground:Accurate prediction scores for liver steatosis are demanded to enable clinicians to noninvasively screen for nonalcoholic fatty liver disease (NAFLD). Several prediction scores have been developed, however external validation is lacking.Objective:The aim was to determine the diagnostic accuracy of four existing prediction scores in severely obese children, to develop a new prediction score using novel biomarkers and to compare these results to the performance of ultrasonography.Design and Results:Liver steatosis was measured using proton magnetic resonance spectroscopy in 119 severely obese children (mean age 14.3 ± 2.1 years, BMI z‐score 3.35 ± 0.35). Prevalence of steatosis was 47%. The four existing predictions scores (“NAFLD liver fat score,” “fatty liver index,” “hepatic steatosis index,” and the pediatric prediction score) had only moderate diagnostic accuracy in this cohort (positive predictive value (PPV): 70, 61, 61, 69% and negative predictive value (NPV) 77, 69, 68, 75%, respectively). A new prediction score was built using anthropometry, routine biochemistry and novel biomarkers (leptin, adiponectin, TNF‐alpha, IL‐6, CK‐18, FGF‐21, and adiponutrin polymorphisms). The final model included ALT, HOMA, sex, and leptin. This equation (PPV 79% and NPV 80%) did not perform substantially better than the four other equations and did not outperform ultrasonography for excluding NAFLD (NPV 82%).Conclusion:The conclusion is in severely obese children and adolescents existing prediction scores and the tested novel biomarkers have insufficient diagnostic accuracy for diagnosing or excluding NAFLD.
Racial/Ethnic differences in clinical and biochemical type 2 diabetes mellitus risk factors in children
Authors: Rosenbaum Michael , Fennoy Ilene , Accacha Siham , Altshuler Lisa , Carey Dennis E. , Holleran Stephen , Rapaport Robert , Shelov Steven P. , Speiser Phyllis W. , Ten S. , Bhangoo Amrit , Boucher‐Berry Claudia , Espinal Yomery , Gupta Rishi , Hassoun Abeer A. , Iazetti Loretta , Jean-Jacques Fabienne , Jean Amy M. , Klein Michelle L. , Levine Robet , Lowell Barbara , Michel Lesley , Rosenfeld Warren 
Published: April 2013

ObjectiveTo examine whether periadolescent children demonstrate the significant racial/ethnic differences in body fatness relative to BMI and in the prevalence and relationship of body composition to risk factors for type 2 diabetes (T2DM) as in adults.Design and MethodsFamily history of obesity and T2DM, anthropometry, insulin sensitivity and secretory capacity, lipids, and cytokines (IL‐6, CRP, TNF‐α, and adiponectin) were examined in a cohort of 994 middle school students (47% male, 53%, female; 12% African American, 14% East Asian, 13% South Asian, 9% Caucasian, 44% Hispanic, and 8% other).ResultsFractional body fat content was significantly greater at any BMI among South Asians. There were racial/ethnic specific differences in lipid profiles, insulin secretory capacity, insulin sensitivity, and inflammatory markers corrected for body fatness that are similar to those seen in adults. Family history of T2DM was associated with lower insulin secretory capacity while family history of obesity was more associated with insulin resistance.ConclusionsChildren show some of the same racial/ethnic differences in risk factors for adiposity‐related comorbidities as adults. BMI and waist circumference cutoffs to identify children at‐risk for adiposity‐related comorbidities should be adjusted by racial/ethnic group as well as other variables such as birthweight and family history.
White and green screening with circular polymerase extension cloning for easy and reliable cloning
Authors: Speltz Elizabeth B. , Regan Lynne 
Published: April 2013

AbstractCloning is an essential prerequisite to test protein design and engineering ideas. However, it is often time consuming, unreliable, and therefore frustrating. Here, we present a streamlined cloning strategy that incorporates a powerful white and green screening protocol to identify colonies with inserts. We use circular polymerase extension cloning, which is both ligation and sequence independent. Furthermore, our entire procedure requires only three quick steps and one enzyme making it easy to use, inexpensive, and tractable. We anticipate that this method will be particularly useful for protein engineers who frequently subclone or make focused deletion, insertion, or substitution libraries.
Metal–supported catalysts encapsulated in mesoporous solids: Challenges and opportunities of a model concept
Authors: Grünert Wolfgang , Gies Hermann , Muhler Martin , Polarz Sebastian , Lehmann Christian W. , Großmann Dennis , van den Berg Maurits , Tkachenko Olga P. , De Toni Andrea , Sinev Ilya , Bandyopadhyay Mahuya , Narkhede Vaishali , Dreier Axel , Klementiev Konstantin V. , Birkner Alexander , Löffler Elke 
Published: April 2013

AbstractAn overview of work with model systems designed to study metal–support interactions in heterogeneous catalysts is given. In these models, metal and support are both miniaturized by introduction as guests into a mesoporous host. The use of such models is demonstrated with AuTiO2 clusters encaged in MCM‐48, and CuZnO clusters encapsulated in siliceous mesopore systems and in carbon nanotubes. The models promise a better opportunity to track changes in the support component during catalyst activation and catalysis, including the action of poisons that may at first be trapped on the support surface. Challenges to be met are the stabilization of the mesoporous matrix during synthesis and catalysis, possible reactivity of the matrix surface towards any of the catalyst components, as well as clustering and segregation of the latter from the matrix. The challenges were encountered as pore damage during preparation of AuTiO2/MCM‐48 catalysts, as deactivating interactions of siliceous walls with zinc ions during deposition of zinc species from aqueous media, and as clustering of the Cu component during calcination and reduction. Among the conclusions drawn from the studies are the irrelevance of order at the AuTiO2 interface (and, hence, of epitaxy and of crystal strain in gold) for high activity of Au/TiO2 catalysts in CO oxidation. In the models for CuZnO methanol synthesis catalysts, two different types of CuZn interaction could be observed: a direct contact between Zn2+ and Cu(0) under strong reducing conditions, and the formation of alloy nanoparticles (nano‐brass). A discussion of the relevance of these interactions for the methanol synthesis reaction is given.
Glycophthalocyanines: structural differentiation and isomeric differentiation by matrix‐assisted laser desorption/ionization tandem mass spectrometry
Authors: Soares Ana R. M. , Neves Maria G. P. M. S. , Santos Sérgio M. , Tomé João P. C. , Tomé Augusto C. , Cavaleiro José A. S. , Torres Tomás , Domingues M. Rosário M. 
Published: April 2013

RATIONALEGlycophthalocyanines have a great promising potential in many scientific areas. However, their structural characterization is not an easy task. To overcome this drawback, it is urgent to develop simple and efficient methodologies to characterize this type of compounds. In this work, we describe the use of matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) and MALDI‐MS/MS of the [M+H]+ to distinguish between two isomeric glycophatholocyanines bearing four galactose units with protected (1a and 2a) or unprotected hydroxyl groups (1b and 2b).METHODSThe MALDI‐MS and MALDI‐MS/MS spectra were acquired using a MALDI‐TOF/TOF Applied Biosystems 4800 Proteomics Analyzer instrument equipped with a nitrogen laser and using dithranol as matrix. Computational studies were performed in order to gain insights into the mechanisms underlying the different fragmentation pathways observed for the isomeric species.RESULTSThe fragmentation pattern observed in MALDI‐MS/MS spectra of the [M+H]+ ion was dependent on the peripheral distribution of the sugar units. Phthalocyanines (Pcs) with a sugar unit in each isoindole ring show the typical loss of sugar units (cleavage of C6–O bond) while Pcs with the four sugar units linked to the same isoindole ring show a major and unusual fragmentation pathway corresponding to the cleavage of the C5–C6 bond of the sugar units. This type of fragmentation is not usually observed in the MS/MS of oligosaccharides.CONCLUSIONSMALDI–MS is a valuable tool for the structural characterization/differentiation of isomeric glycophthalocyanines. Copyright © 2013 John Wiley & Sons, Ltd.
Laser‐induced dissociation of singly protonated peptides at 193 and 266 nm within a hybrid linear ion trap mass spectrometer
Authors: Lai Cheuk‐Kuen , Ng Dominic C. M. , Pang H. F. , Le Blanc J. C. Yves , Hager James W. , Fang De‐Cai , Cheung A. S.‐C. , Chu Ivan K. 
Published: April 2013

RATIONALEWe implemented, for the first time, laser‐induced dissociation (LID) within a modified hybrid linear ion trap mass spectrometer, QTrap, while preserving the original scanning capabilities and routine performance of the instrument.METHODSPrecursor ions of interest were mass‐selected in the first quadrupole (Q1), trapped in the radiofrequency‐only quadrupole (q2), photodissociated under irradiation with a 193‐ or 266‐nm laser beam in the third quadrupole (q3), and mass‐analyzed using the linear ion trap.RESULTSLID of singly charged protonated peptides revealed, in addition to conventional amide‐bond cleavages, preferential fragmentation at Cα–C/N–Cα bonds of the backbone as well as at the Cα–Cβ/Cβ–Cγ bonds of the side‐chains. The LID spectra of [M+H]+ featured product ions that were very similar to the observed radical‐induced fragmentations in the CID spectra of analogous odd‐electron radical cations generated through dissociative electron‐transfer in metal‐ligand–peptide complexes or through laser photolysis of iodopeptides.CONCLUSIONSLID of [M+H]+ ions results in fragmentation channels that are comparable with those observed upon the CID of M•+ ions, with a range of fascinating radical‐induced fragmentations. Copyright © 2013 John Wiley & Sons, Ltd.
Fragmentations of [M − H]− anions of peptides containing tyrosine sulfate. Does the sulfate group rearrange? A joint experimental and theoretical study
Authors: Nha Tran T. T. , Wang Tianfang , Hack Sandra , Bowie John H. 
Published: April 2013

RATIONALETo investigate the fragmentations in the negative‐ion electrospray mass spectra of peptides containing tyrosine sulfate.METHODSPossible fragmentation mechanisms were explored using a Waters QTOF2 tandem mass spectrometer in concert with calculations at the CAM‐B3LYP/6‐311++g(d,p) level of theory.RESULTSThe major negative ion formed in the ESI‐MS of peptides containing tyrosine sulfate is [(M − H) − SO3]− and this process normally yields the base peak of the spectrum. The basic backbone cleavages of [(M − H) − SO3]− allowed the sequence of the peptide to be determined. Rearrangement reactions involving the formation of HOSO3− and [(M − H)−H2SO4]− yielded minor peaks with relative abundances ≤ 10% and ≤ 2%, respectively.CONCLUSIONSThe mass spectra of the [M − H]− and [(M − H)−SO3]− anions of peptides containing tyrosine sulfate allowed the position of the tyrosine sulfate group to be determined, together with the amino acid sequence of the peptide. Copyright © 2013 John Wiley & Sons, Ltd.
Covalent protein immobilization with a parylene‐H film for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Kim Jo‐Il , Lee Ga‐Yeon , Ko Hyuk , Kang Min‐Jung , Pyun Jae‐Chul 
Published: April 2013

RATIONALEFor the sensitive analysis of receptor‐ligand interactions by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry (MS), receptor proteins should be immobilized on a target plate with a high surface density. In this work, a parylene‐H film with formyl groups was developed for the efficient covalent immobilization of receptor proteins for MALDI‐TOF MS.METHODSThe parylene‐H film was thermally deposited on a target plate and receptor proteins were covalently immobilized. The surface properties of the parylene‐H film were analyzed by atomic force microscopy (AFM) and cyclic voltammetry (CV). The immobilization efficiency of the parylene‐H film was analyzed by fluorescence imaging with streptavidin and fluorescence‐labeled biotin. MALDI‐TOF MS was performed using the parylene‐H‐coated target plate with streptavidin and different concentrations of biotinylated peptide as the receptor and ligand, respectively.RESULTSThe parylene‐H film on a target plate had a flat surface (Rq: ±2.755 nm) without any pinholes and could be regarded to be electrically conductive under an electric potential of 30 kV. The fluorescence image proved that the parylene‐H film improved the protein immobilization efficiency as well as ligand detection sensitivity. The mass spectra quantitatively revealed peaks from the ligand molecules without any interference peaks from the immobilized receptor proteins.CONCLUSIONSA parylene‐H film with formyl groups was thermally deposited on a target plate and the receptor protein was covalently immobilized on the target plate. The interactions of ligand molecules with the immobilized receptor proteins were quantitatively analyzed by MALDI‐TOF MS. Copyright © 2013 John Wiley & Sons, Ltd.
The Professionalization of Ethics in the Intergovernmental Panel on Climate Change (IPCC) – from Servant of Science to Ethical Master?
Authors: Skoglund Annika , Jensen Tommy 
Published: April 2013

ABSTRACTSolutions to climate change have been academically criticized for their continued economic growth, managerialism and lack of real politics. In comparison, the IPCC's socio‐economic assessments of climate change have accentuated the ethical implications of their own policy recommendations. Our analysis of ten IPCC reports (1990–2012) shows a turn from a claimed non‐political position in human‐induced climate change to an outspoken ethical position in climate‐induced disasters. We argue that a professionalization of climate ethics is sought through ecological reason, specifically by calls for resilience to foster adaptable subjects. This neoliberal position leans on a problematization of vulnerable subjects' resistance to social adaptation, underpinned by an aim to redirect resistance towards physical disasters to stimulate climate adaptation. Conclusively, climate ethical mastery is formed by detailed elaborations of how the vulnerable subject should not only subsume to ecological reason, but also ethically embrace physical threats and dangers as if productive of life supportive qualities. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Bayesian analysis and classification of two enzyme‐linked immunosorbent assay tests without a gold standard
Authors: Zhang Jingyang , Chaloner Kathryn , McLinden James H. , Stapleton Jack T. 
Published: April 2013

AbstractReconciling two quantitative enzyme‐linked immunosorbent assay tests for an antibody to an RNA virus, in a situation without a gold standard and where false negatives may occur, is the motivation for this work. False negatives occur when access of the antibody to the binding site is blocked. On the basis of the mechanism of the assay, a mixture of four bivariate normal distributions is proposed with the mixture probabilities depending on a two‐stage latent variable model including the prevalence of the antibody in the population and the probabilities of blocking on each test. There is prior information on the prevalence of the antibody, and also on the probability of false negatives, and so a Bayesian analysis is used. The dependence between the two tests is modeled to be consistent with the biological mechanism. Bayesian decision theory is utilized for classification.The proposed method is applied to the motivating data set to classify the data into two groups: those with and those without the antibody. Simulation studies describe the properties of the estimation and the classification. Sensitivity to the choice of the prior distribution is also addressed by simulation. The same model with two levels of latent variables is applicable in other testing procedures such as quantitative polymerase chain reaction tests, where false negatives occur when there is a mutation in the primer sequence. Copyright © 2013 John Wiley & Sons, Ltd.
Function Representation for the Strain Field during the Steel Forging and Its Application on the Deformation of Void Defects
Authors: Chen Kun , Liu Kejia , Chen Huifen , Yang Yitao 
Published: April 2013

AbstractA novel method for description of the strain field distributions during the steel forging was proposed in the present study, i.e., function representation for the strain field. Through deduction and calculation of the strain field function, the deformation characteristic of the void defects was obtained and the empirical features of void closure were quantitatively calculated based on the method. The analytical results of the deformation degree in size of the void and the critical condition of void closure were verified by numerical simulation, which shows the deviation is within 7%. During the practical process, the void closing region determined by the method can be developed to prediction of internal void closure, which simplifies the models with void. This methodology provides the scientific basis for process design in consideration of elimination of internal void defects.
Epigenetic Regulation of SOX9 by the NF-κB Signaling Pathway in Pancreatic Cancer Stem Cells
Authors: Sun Lei , Mathews Lesley A. , Cabarcas Stephanie M. , Zhang Xiaohu , Yang Acong , Zhang Ying , Young Matthew R. , Klarmann Kimberly D. , Keller Jonathan R. , Farrar William L. 
Published: April 2013

Abstract
Pancreatic cancer is the fourth leading cause of cancer-related mortality in the world. Pancreatic cancer can be localized, locally advanced, or metastatic. The median 1- and 5-year survival rates are 25% and 6%, respectively. Epigenetic modifications such as DNA methylation play a significant role during both normal human development and cancer progression. To investigate epigenetic regulation of genes in the tumor-initiating population of pancreatic cancer cells, which are also termed cancer stem cells (CSCs), we conducted epigenetic arrays in PANC1 and HPAC pancreatic cancer cell lines and compared the global DNA methylation status of CpG promoters in invasive cells, demonstrated to be CSCs, to their noninvasive counterparts, or non-CSCs. Our results suggested that the NF-κB pathway is one of the most activated pathways in pancreatic CSCs. In agreement with this, we determined that upon treatment with NF-κB pathway inhibitors, the stem cell-like properties of cells are significantly disrupted. Moreover, SOX9, demethylated in CSCs, is shown to play a crucial role in the invasion process. Additionally, we found a potential NF-κB binding site located in the SOX9 promoter and determined that the NF-κB subunit p65 positively regulates SOX9 expression by binding to its promoter directly. This interaction can be efficiently blocked by NF-κB inhibitors. Thus, our work establishes a link between the classic NF-κB signaling transduction pathway and the invasiveness of pancreatic CSCs, which may result in the identification of novel signals and molecules that function at an epigenetic level, and could potentially be targeted for pharmaceutical investigations and clinical trials.
Improving Accuracy and Confidence in Distal Radius Volar Plate Screw Placement through Supplemental Radiography: Examining Specialty, Education, and Experience Levels
Authors: Patel Archit , Culbertson Maya Deza , Lahey Philip , Semenovski Michael , Choueka Jack 
Published: April 2013

Background The purpose of this study was to assess the extent to which a supplemental radiographic view increases accuracy and confidence ratings when determining screw placement in volar plating of distal radius fractures for evaluators of different specialties and experience levels. Methods Thirty-four distal radius fractures treated with volar plate fixation were imaged using standard AP and lateral, and supplemental lateral tilt views. Each case was then evaluated for penetration of distal screw tips into the articular space. Sixty-five physicians then completed a two-phase analysis and survey of these cases. In the first phase, presentation consisted only of AP and lateral views; in the second, the lateral tilt view was added. Participants were asked to determine whether distal screws penetrated the joint and rate their confidence in the determination. Assessments were scored for correctness; changes in accuracy and confidence levels between phases were analyzed using paired t tests. Comparisons between groups were performed by ANOVA. Results Supplementation increased accuracy and confidence in all position, specialty, and experience groups. Confidence scores were significantly higher following evaluation of three views versus two views. Residents exhibited the greatest improvements in accuracy and confidence. For first-phase (standard view) assessments, accuracy scores were significantly better for attendings with less than 10 years post-fellowship experience than those with more. Conclusions A supplemental view of the distal radius combined with AP and lateral views significantly improves the ability of all evaluators, regardless of specialty or training level, to correctly assess placement of fixation screws. The greatest improvements are seen for resident trainees.