bluuebunny/crossref_metadata_2025_split huggingface dataset:
A QM/MM Investigation of the Catalytic Mechanism of Metal‐Ion‐Independent Core 2 β1,6‐N‐Acetylglucosaminyltransferase
Authors: Tvaroška Igor , Kozmon Stanislav , Wimmerová Michaela , Koča Jaroslav 
Published: April 2013

Abstractβ1,6‐GlcNAc‐transferase (C2GnT) is an important controlling factor of biological functions for many glycoproteins and its activity has been found to be altered in breast, colon, and lung cancer cells, in leukemia cells, in the lymhomonocytes of multiple sclerosis patients, leukocytes from diabetes patients, and in conditions causing an immune deficiency. The result of the action of C2GnT is the core 2 structure that is essential for the further elongation of the carbohydrate chains of O‐glycans. The catalytic mechanism of this metal‐ion‐independent glycosyltransferase is of paramount importance and is investigated here by using quantum mechanical (QM) (density functional theory (DFT))/molecular modeling (MM) methods with different levels of theory. The structural model of the reaction site used in this report is based on the crystal structures of C2GnT. The entire enzyme–substrate system was subdivided into two different subsystems: the QM subsystem containing 206 atoms and the MM region containing 5914 atoms. Three predefined reaction coordinates were employed to investigate the catalytic mechanism. The calculated potential energy surfaces discovered the existence of a concerted SN2‐like mechanism. In this mechanism, a nucleophilic attack by O6 facilitated by proton transfer to the catalytic base and the separation of the leaving group all occur almost simultaneously. The transition state for the proposed reaction mechanism at the M06‐2X/6‐31G** (with diffuse functions on the O1′, O5′, OGlu, and O6 atoms) level was located at C1O6=1.74 Å and C1O1=2.86 Å. The activation energy for this mechanism was estimated to be between 20 and 29 kcal mol−1, depending on the method used. These calculations also identified a low‐barrier hydrogen bond between the nucleophile O6H and the catalytic base Glu320, and a hydrogen bond between the N‐acetamino group and the glycosidic oxygen of the donor in the TS. It is proposed that these interactions contribute to a stabilization of TS and participate in the catalytic mechanism.
Iridium(I) Hydroxides: Powerful Synthons for Bond Activation
Authors: Truscott Byron J. , Nelson David J. , Lujan Cristina , Slawin Alexandra M. Z. , Nolan Steven P. 
Published: April 2013

AbstractA family of iridium(I) hydroxides of the form [Ir(cod)(NHC)(OH)] (cod=1,5‐cyclooctadiene, NHC=N‐heterocyclic carbene) is reported. Single‐crystal X‐ray analyses and computational methods were used to explore the structural characteristics and steric properties of these new complexes. The model complex [Ir(cod)(IiPr)(OH)] (IiPr=1,3‐(diisopropyl)imidazol‐2‐ylidene) undergoes reaction with a wide variety of substrates including boronic acids and silicon compounds. In addition, OH, NH and CH bond activation was achieved with alcohols, carboxylic acids, amines and various sp‐, sp2‐ and sp3‐hybridised carbon centres, giving access to a wide range of new IrI complexes. These studies have allowed us to explore the exciting reactivity of this motif, revealing a versatile and useful synthon capable of activating important chemical bonds under mild (typically room temperature) conditions. No additives were required and, in the case of XH bond activation, water was the only waste product, rendering this an atom efficient procedure for bond activation. This system has great potential for the construction of new catalytic cycles for organic synthesis and small‐molecule activation.
Effect of CeO2 Addition to Al2O3 Supports for Pt Catalysts on the Aqueous‐Phase Reforming of Glycerol
Authors: Rahman M. M. , Church Tamara L. , Minett Andrew I. , Harris Andrew T. 
Published: April 2013

AbstractA series of Pt catalysts supported on Al2O3 that was doped with different amounts of CeO2 was developed, characterized, and tested in the aqueous‐phase reforming (APR) of glycerol to H2. Catalyst 3Pt/3CeAl, which bore 3 wt % Pt on a support that contained 3 wt % CeO2, showed the highest carbon conversion to gas (85 %) and the highest H2 yield (80 %) for a feedstock of 1 wt % glycerol in water at 240 °C and 40 bar. A CeO2/Al2O3 support with only 1 wt % Pt also showed high H2 selectivity and carbon conversion to gas, as well as a much lower CH4 yield than the benchmark 3Pt/Al catalyst, clearly demonstrating that doping the support with 3 wt % CeO2 improved the APR of glycerol. H2 chemisorption results showed that the highest metal dispersion (58 %) and active surface area (4.3 m2 g−1) were achieved for the support that contained 3 wt % CeO2, and this effect appeared to be primarily responsible for the high H2 yield and carbon conversion to gas. No CO was observed in the product gas; therefore, this gas could potentially be used directly in proton exchange membrane fuel cells. Thus, including CeO2 in the Al2O3 catalyst support enhanced both the activity and selectivity towards H2 of a Pt catalyst for the APR of glycerol.
Estimating and scaling stream ecosystem metabolism along channels with heterogeneous substrate
Authors: Hondzo Miki , Voller Vaughan R. , Morris Mark , Foufoula‐Georgiou Efi , Finlay Jacques , Ganti Vamsi , Power Mary E. 
Published: April 2013

ABSTRACTMeasured diurnal curves of dissolved oxygen (DO) concentration have been used to estimate the gross primary production (GPP), ecosystem respiration (R), and net ecosystem production (NP) of aquatic communities. Open‐system one‐station and two‐station methods have been employed to estimate the rate of NP, R, and GPP. We conducted field measurements in Minnehaha Creek, MN (44o56'N, 93o28'W), to quantify the spatial and temporal variabilities of DO concentrations and, consequently, evaluated the estimates of NP. Dimensionless analysis of DO mass balance revealed the dominance of local photosynthesis over respiration, advection, re‐aeration, and dispersion along the studied reach. Two alternative estimation methods of stream metabolism provided similar estimates of NP with 0.65 > kaTa > 0.17 within the studied reach where ka is the re‐aeration rate and Ta is the water parcel average travel time. The spatial variability of DO change along the creek revealed an average length scale of 10 m over which DO exhibited significant autocorrelation. The autotrophic–heterotrophic balance, quantified by GPP to R ratio, scaled with local stream geomorphic and hydraulic conditions from diverse geographic areas, providing useful predictive relationships expressed in terms of easily measurable abiotic parameters. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of 5‐Organotellanyl‐1H‐1,2,3‐tri­azoles: Functionalization of the 5‐Position Scaffold by the Sonogashira Cross‐Coupling Reaction
Authors: Stefani Hélio A. , Vasconcelos Stanley N. S. , Manarin Flávia , Leal Daiana M. , Souza Frederico B. , Madureira Lucas Sousa , Zukerman‐Schpector Julio , Eberlin Marcos N. , Godoi Marla N. , de Souza Galaverna Renan 
Published: April 2013

AbstractAn efficient synthesis of 5‐organotellanyl‐1H‐1,2,3‐triazole compounds was accomplished through [3+2] cycloaddition reaction of organic azides and (organotellanyl)alkynes. Additionally, 5‐organotellanyl‐1H‐1,2,3‐triazoles were readily functionalized at the 5‐position by using a Sonogashira cross‐coupling reaction, leading to highly functionalised triazoles. The regiochemistry of the products was assessed by two‐dimensional NMR spectroscopic experiments and X‐ray crystallography.
A dynamic QoE routing system for user‐centric applications
Authors: Tran Hai Anh , Mellouk Abdelhamid , Hoceini Said , Augustin Brice , Zeadally Sherali 
Published: April 2013

ABSTRACTToday, maintaining the best quality of experience (QoE) as the subjective perception of end‐users is one of the most important requirements of both wireless and wired networks. To achieve this goal, we frequently use network functions such as admission control, resource management, routing and traffic control. We focus on the design and evaluation of a QoE‐aware routing mechanism. We present an end‐to‐end model where Smartphone users connect to content servers through a wired network across a wireless access network. We propose an adaptive and evolutionary system with a QoE‐aware routing protocol, namely QoE Q‐learning‐based adaptive routing. Our experimental results demonstrate significant performance improvements in mean opinion score for various network loads, convergence time during the initialisation phase and control overheads over other traditional approaches.Copyright © 2013 John Wiley & Sons, Ltd.
On the study of fundamental trade‐offs between QoE and energy efficiency in wireless networks
Authors: Zhang X. , Zhang J. , Huang Y. , Wang W. 
Published: April 2013

ABSTRACTDuring recent years, for the ever‐growing number of users with the exponential growth of high‐data‐rate traffic demand, quality of experience (QoE) has emerged as an important issue, providing important measures and assessment metrics for users, service providers and operators. Meanwhile, rapid development of information and communications technology significantly contributes to the increasing trend of energy consumption and global warming. As a result, green communications that mainly studies energy efficiency (EE) has become an inevitable method to reduce energy consumption, which attracts the attention of both the academia and industries. However, currently, very few research works have been carried out to address the relationship between QoE and EE, which is an important issue for designing a system with QoE and EE trade‐offs. In this paper, we show that there exist fundamental trade‐offs between EE and QoE for users with different traffics, that is, voice, best effort and quality‐of‐service traffic, considering various power consumptions including transmission power, circuit power, interference and network bandwidth all together. A new metric of QoE per watt is introduced, and the fundamental EE–QoE relationship is addressed for different proportions of user groups in an interference‐limited cellular network.Copyright © 2013 John Wiley & Sons, Ltd.
A simplified model for predicting the ignition of FRP composites with validation using intermediate‐scale fire experiment data
Authors: Tian Ning , Zhou Aixi 
Published: April 2013

ABSTRACTThis study presents a simplified theoretical model to predict the ignition of FRP composites of general thermal thickness (GTT) subjected to one‐sided heating. A simplified GTT heat transfer model to predict the surface temperature of GTT composite panels was developed, and the exposed surface temperature was used as ignition criterion. To validate the GTT model, intermediate scale calorimeter fire tests of E‐glass fiber reinforced polyester composite panels at three heat flux levels were performed to obtain intermediate‐scale fire testing data in a controlled condition with well‐defined thermal boundary conditions. The GTT model was also verified by using results from finite element modeling predictions. This model can be used to estimate the surface temperature increase, time‐to‐ignition, and mass loss of FRP composites for fire safety design and analysis. Copyright © 2013 John Wiley & Sons, Ltd.
Back‐arc extension in the Andaman Sea: Tectonic and magmatic processes imaged by high‐precision teleseismic double‐difference earthquake relocation
Authors: Diehl T. , Waldhauser F. , Cochran J. R. , Kamesh Raju K. A. , Seeber L. , Schaff D. , Engdahl E. R. 
Published: April 2013

AbstractThe geometry, kinematics, and mode of back‐arc extension along the Andaman Sea plate boundary are refined using a new set of significantly improved hypocenters, global centroid moment tensor (CMT) solutions, and high‐resolution bathymetry. By applying cross‐correlation and double‐difference (DD) algorithms to regional and teleseismic waveforms and arrival times from International Seismological Centre and National Earthquake Information Center bulletins (1964–2009), we resolve the fine‐scale structure and spatiotemporal behavior of active faults in the Andaman Sea. The new data reveal that back‐arc extension is primarily accommodated at the Andaman Back‐Arc Spreading Center (ABSC) at ~10°, which hosted three major earthquake swarms in 1984, 2006, and 2009. Short‐term spreading rates estimated from extensional moment tensors account for less than 10% of the long‐term 3.0–3.8 cm/yr spreading rate, indicating that spreading by intrusion and the formation of new crust make up for the difference. A spatiotemporal analysis of the swarms and Coulomb‐stress modeling show that dike intrusions are the primary driver for brittle failure in the ABSC. While spreading direction is close to ridge normal, it is oblique to the adjacent transforms. The resulting component of E‐W extension across the transforms is expressed by deep basins on either side of the rift and a change to extensional faulting along the West Andaman fault system after the Mw = 9.2 Sumatra‐Andaman earthquake of 2004. A possible skew in slip vectors of earthquakes in the eastern part of the ABSC indicates an en‐echelon arrangement of extensional structures, suggesting that the present segment geometry is not in equilibrium with current plate‐motion demands, and thus the ridge experiences ongoing re‐adjustment.
Gestational weight loss and perinatal outcomes in overweight and obese women subsequent to diagnosis of gestational diabetes mellitus
Authors: Yee Lynn M. , Cheng Yvonne W. , Inturrisi Maribeth , Caughey Aaron B. 
Published: April 2013

ObjectiveTo investigate whether gestational weight loss (GWL) after the diagnosis of gestational diabetes mellitus (GDM) in overweight and obese women is associated with improved perinatal outcomes. Obesity and GDM are risk factors for adverse perinatal outcomes, but few studies have investigated weight loss during pregnancy in women with these comorbidities.Design and MethodsRetrospective cohort study of 26,205 overweight and obese gestational diabetic women enrolled in the California Diabetes and Pregnancy Program. Women with GWL during program enrollment were compared to those with weight gain. Perinatal outcomes were assessed using chi‐square test and multivariable logistic regression analysis.ResultsAbout 5.2% of women experienced GWL. GWL was associated with decreased odds of macrosomia (aOR 0.63, 95% CI 0.52‐0.77), NICU admission (aOR 0.51, 95% CI 0.27‐0.95), and cesarean delivery (aOR 0.81, 95% CI 0.68‐0.97). Odds of SGA status (aOR 1.69, 95% CI 1.32‐2.17) and preterm delivery <34 weeks (aOR 1.71, 95% CI 1.23‐2.37) were increased.ConclusionsIn overweight and obese women with GDM, third trimester weight loss is associated with some improved maternal and neonatal outcomes, although this effect is lessened by increased odds of SGA status and preterm delivery. Further research on weight loss and interventions to improve adherence to weight guidelines in this population is recommended.
Circulating endocannabinoids in insulin sensitive vs. Insulin resistant obese postmenopausal women. A MONET group study
Authors: Abdulnour Joseph , Yasari Siham , Rabasa‐Lhoret Rémi , Faraj May. , Petrosino Stefania , Piscitelli Fabiana , Prud' homme Denis , Di Marzo Vincenzo 
Published: April 2013

ObjectiveTo measure the circulating levels of endocannabinoids and related molecules at fasting, after acute hyperinsulinemia and after weight loss in insulin sensitive vs. insulin resistant obese postmenopausal women.Design and MethodsThe sample consisted of 30 obese postmenopausal women (age: 58.9 ± 5.2 yrs; BMI: 32.9 ± 3.6 kg/m2). Subjects underwent a 3‐hour hyperinsulinaemic‐euglycaemic clamp (HEC) (glucose disposal rate (M‐value): 10.7 ± 3.3 mg min−1 kg−1 FFM) and 6‐month weight loss intervention. Participants were classified as insulin sensitive obese (ISO) or insulin resistant obese (IRO) based on a predefined cutoff. Plasma levels of the endocannabinoids, anandamide (AEA), 2‐arachidonoylglycerol (2‐AG), and of the AEA‐related compounds, palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), were measured by liquid chromatography‐mass spectrometry.ResultsIRO presented higher levels of 2‐AG (P < 0.05) independently of the HEC and weight loss, whereas the HEC had an independent inhibitory effect on AEA, PEA, and OEA levels (P < 0.05) in both groups. Furthermore, there was an independent stimulatory effect of weight loss only on PEA levels in both groups (P < 0.05).ConclusionsThis study is the first to show that higher circulating levels of the endocannabinoid 2‐AG are found in IRO compared to ISO postmenopausal women, and that weight loss is associated with an increase in PEA, a PPAR‐α ligand.
Dasatinib inhibits mammary tumour development in a genetically engineered mouse model
Authors: Karim Saadia A , Creedon Helen , Patel Hitesh , Carragher Neil O , Morton Jennifer P , Muller William J , Evans Thomas RJ , Gusterson Barry , Sansom Owen J , Brunton Valerie G 
Published: April 2013

AbstractSrc family kinase activity is elevated in a number of human cancers including breast cancer. This increased activity has been associated with aggressive disease and poor prognosis. Src inhibitors are currently in clinical development with a number of trials currently assessing their activity in breast cancer. However, the results to date have been disappointing and a further evaluation of the preclinical effects of Src inhibitors is required to help establish whether these agents will be useful in the treatment of breast cancer. In this study we investigate the effects of dasatinib, which is a potent inhibitor of Src family kinases, on the initiation and development of breast cancer in a genetically engineered model of the disease. The mouse model utilized is driven by expression of activated ErbB‐2 under the transcriptional control of its endogenous promoter coupled with conditional loss of Pten under the control of Cre recombinase expressed by the BLG promoter. We show that daily oral administration of dasatinib delays tumour onset and increases overall survival but does not inhibit the proliferation of established tumours. The striking difference between the dasatinib‐treated group of tumours and the vehicle controls was the prominent squamous metaplasia that was seen in six out of 11 dasatinib‐treated tumours. This was accompanied by a dramatic up‐regulation of both E‐cadherin and β‐catenin and down‐regulation of ErbB‐2 in the dasatinib‐treated tumours. Dasatinib also inhibited both the migration and the invasion of tumour‐derived cell lines in vitro. Together these data support the argument that benefits of Src inhibitors may predominate in early or even pre‐invasive disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Association between first‐trimester maternal serum pregnancy‐associated plasma protein‐A and obstetric complications
Authors: D'Antonio Francesco , Rijo Claudia , Thilaganathan Basky , Akolekar Ranjit , Khalil Asma , Papageourgiou Aris , Bhide Amar 
Published: April 2013

ABSTRACTObjectiveThis study aimed to investigate the relationship between maternal serum pregnancy‐associated plasma protein‐A (PAPP‐A) in the first trimester of pregnancy and the development of preeclampsia (PE), early PE, small‐for‐gestational age (SGA) fetus and preterm delivery (PD).MethodThis is a retrospective study of 12 355 pregnant women that delivered between 2008 and 2011. We define the first, third and fifth percentiles of maternal serum PAPP‐A multiples of the median (MoM). The primary outcome measures were the occurrence of PE, early PE (PE requiring delivery before 34 weeks), SGA fetus (birth weight < 5th centile) and PD. The Mann–Whitney U‐test and chi‐squared test were used to analyze continuous and dichotomous variables, respectively.ResultsMaternal serum PAPP‐A was significantly lower in women with PE, early PE, SGA fetus and PD (0.91, 0.74, 0.80 and 0.84 MoM, respectively) than in the study population (0.99 MoM) (p < 0.05). The lower the MoM percentile of PAPP‐A, the higher are the odds ratio (OR) to develop PE, early PE, SGA fetus and PD.ConclusionsMaternal serum PAPP‐A levels are lower in women who develop preeclampsia, those with SGA fetus and those who deliver preterm. However, on its own, maternal serum PAPP‐A performs poorly (OR for PE between 1.76 and 2.41 with the lower percentile of PAPP‐A) as a screening test for these conditions. © 2013 John Wiley & Sons, Ltd.
Increased nuchal translucency and pregnancy outcome: a retrospective study of 1063 consecutive singleton pregnancies in a single referral institution
Authors: Äyräs Outi , Tikkanen Minna , Eronen Marianne , Paavonen Jorma , Stefanovic Vedran 
Published: April 2013

ABSTRACTObjectivesThe goals of this study are to assess pregnancy outcome with increased nuchal translucency (NT) and to determine the risk of adverse pregnancy outcome in relation to the degree of increased NT.MethodsAll singleton pregnancies with increased NT at the first screening ultrasound examination referred to the Department of Fetal Medicine at the Helsinki University Central Hospital during 2002 to 2007 were included. Pregnancy outcomes and short‐term outcomes of the newborns were recorded and analyzed.ResultsOf the 1063 pregnancies, karyotype was normal in 834 (78%). The majority, 611 (73%), of euploid fetuses was in the lowest NT group (95th percentile – 3.4 mm). Percentage of favorable outcome decreased from 92% in the lowest NT group (95th percentile – 3.4 mm) to 18% in the highest NT group (≥6.5 mm). Structural defects or genetic disorders were observed in 74 (9%) of cases with normal karyotype, of which 43 (58%) resulted in live birth, 25 (34%) in termination of pregnancy, and 6 (8%) in miscarriage or perinatal death.ConclusionsEven minimal (95th percentile – 3.4 mm) increase in NT thickness is associated with adverse pregnancy outcome also in euploid fetuses. © 2013 John Wiley & Sons, Ltd.
Self‐esteem and other‐esteem in college students with borderline and avoidant personality disorder features: An experimental vignette study
Authors: Bowles David P. , Armitage Chris J. , Drabble Jennifer , Meyer Björn 
Published: April 2013

ABSTRACTAn experimental study investigated self‐esteem and other‐esteem responses to either fully supportive or less supportive interpersonal feedback in college students with avoidant and borderline personality disorder features (APD and BPD respectively). Disturbances in self‐esteem and in evaluations of others are central to definitions of both APD and BPD, but the extent to which such interpersonal appraisals are responsive to contextual features, such as evaluative feedback from others, is not yet clear. In theory, we would expect that individuals with pronounced PD features would show more inflexible and more negative self‐evaluations and others‐ evaluations than those without PD features. In this study with 169 undergraduates, APD but not BPD features were associated with other‐contingent state self‐esteem and other‐esteem. A significant interaction indicated that highly avoidant respondents felt particularly negatively about themselves and their close others in situations that conveyed subtle criticism but not in situations signalling unequivocal support. This suggests that their self‐esteem and other‐esteem, rather than being rigidly negative, are instead highly contingent upon interpersonal feedback. Such context contingency has implications for the trait‐like description of diagnostic characteristics within current taxonomies and is in line with contemporary dynamic models of personality structure and process. Copyright © 2013 John Wiley & Sons, Ltd.