bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial patterns of moisture variations across the Tibetan Plateau during the past 700 years and their relationship with Atmospheric Oscillation modes
Authors: Wang Jianglin , Yang Bao , Qin Chun , Kang Shuyuan
Published: May 2013

Spatial and temporal variations in moisture across the Tibetan Plateau (TP) during the years 1300–2005 were investigated using 50 gridded Palmer drought severity index (PDSI) series extracted from the newly developed Monsoon Asia Drought Atlas (MADA). The first four spatial patterns of moisture variations were identified by empirical orthogonal function analysis. They represent coherent moisture variations on the northern, southern, northwestern and southeastern TP, respectively. Similar spatial patterns were seen for the reconstructed and observational PDSI series. Comparisons between the first four principal components (PCs) of 50 MADA‐PDSI and Dai‐PDSI series confirmed that the PCs based on the MADA‐PDSI are reasonable proxies for regional moisture variations over the TP during the past 700 years. During the last century, wetness has generally increased on the northern and southern TP, which is in accord with the simulation of the global monsoon rainfall and paleoclimate records from Monsoonal Asia. The results of spatial correlation analysis indicated that the North Atlantic Oscillation is a primary cause of the contrasting moisture conditions between the northern and southern TP on a decadal time scale. Decadal moisture variations are also closely associated with the Pacific decadal oscillation which contributes to the difference in moisture conditions between the eastern and western TP. Moreover, interannual moisture variations over the TP were found to be closely linked to the El Niño southern oscillation. Large‐scale dryness and wetness are possibly caused by the joint effects of each of these three atmospheric oscillation modes. © 2013 Royal Meteorological Society
Comparison of catabolic rates of fatty acids using stable isotope and isotope‐ratio mass spectrometry
Authors: Gotoh Naohiro , Nagai Toshiharu , Yoshinaga Kazuaki , Mizobe Hoyo , Watanabe Hiroyuki
Published: May 2013

The catabolic rates of individual fatty acids in mice were compared using stable isotope (13C)‐labeled fatty acids and isotope‐ratio mass spectrometry (IRMS). The catabolic rates were evaluated from the ratio of 13C and 12C in carbon dioxide expired by mice. The results showed that the catabolic rate of octanoic acid is three times faster than that of palmitic acid. This result is consistent with previous reports using radioisotope 14C showing that medium‐chain fatty acids are more easily beta‐oxidized than long‐chain fatty acids. The catabolic rates of odd‐numbered fatty acids such as pentadecanoic acid and heptadecanoic acid were significantly lower compared to those of even‐numbered fatty acids such as palmitic acid. These findings support previous reports that show odd‐numbered fatty acids easily accumulating in body fat. The high accumulation of odd‐numbered fatty acids in body fat thus directly reflects a low degree of beta‐oxidization. The combination of stable isotope‐labeled compounds and IRMS serves as a powerful tool in lipid analysis.
Balancing triacylglycerol production and utilization in the liver
Authors: Stanley John
Published: May 2013

The accumulation of triacylglycerols in the liver or steatosis can evolve into more destructive pathological conditions. Understanding how the metabolic pathways of triacylglycerol production and utilisation are balanced and how this balance is lost in insulin resistant states characterised by steatosis is crucial to understanding non‐alcoholic fatty liver disease (NAFLD). Available evidence suggests that oversupply of fatty acids to the liver probably from de novo lipogenesis in the liver itself accounts for steatosis. In addition, steatosis can stimulate de novo lipogenesis by the same mechanism as insulin setting up a vicious circle which may be very hard to break. More research is needed to determine how this vicious circle is initiated.
Tolfenamic acid inhibits colon cancer cell and tumor growth and induces degradation of specificity protein (Sp) transcription factors
Authors: Pathi Satya , Li Xi , Safe Stephen
Published: May 2013

Tolfenamic acid (TA) is a non‐steroidal anti‐inflammatory drug (NSAID) that inhibits lung, esophageal, breast and pancreatic cancer cell and tumor growth, and this study investigated the anticancer activity of TA in colon cancer. TA inhibited growth and induced apoptosis in RKO, SW480, HT‐29, and HCT‐116 colon cancer cells, and TA (50 mg/kg/d) also inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. TA downregulated expression of Sp proteins (Sp1, Sp3, and Sp4) in colon cancer cells and this was accompanied by decreased expression of several Sp‐regulated growth promoting (cyclin D1, hepatocyte growth factor receptor), angiogenic (vascular endothelial growth factor (VEGF) and its receptor 1), survival (survivin and bcl‐2), and inflammatory (NFκBp65/p50) gene products. The mechanism of TA‐mediated effects on Sp proteins was due to activation of caspases. These results now extend the number of NSAIDs that may have clinical potential for colon cancer chemotherapy and show that the anticancer activity of TA is due, in part, to targeting Sp transcription factors. © 2013 Wiley Periodicals, Inc.
The many faces of alpha‐synuclein mutations
Authors: Kasten Meike , Klein Christine
Published: May 2013

Since the first description of alpha‐synuclein (SNCA) mutations in 1997, this gene has probably become the most intensely investigated one associated with monogenic Parkinson disease (PD). Prompted by the finding of a novel SNCA mutation, H50Q, we systematically explored the 145 published SNCA mutation carriers for a possible mutation (type)‐specific clinical expression, which appears to be rather unique to SNCA mutations compared with other PD genes. The A53T mutation is associated with an approximately 10‐year earlier age at onset than the other 3 known missense mutations, including the new H50Q mutation. Similarly, SNCA triplication carriers have an approximately 10‐year earlier onset and a more rapid disease course than duplication carriers, who, overall closely resemble patients with idiopathic PD. Furthermore, higher order SNCA multiplications are associated with additional neurologic features, such as myoclonus. For the nonmotor features, their mere frequency appears less striking than their severity, with an early age of onset of depression or dementia, suicidal ideation, and multimodal hallucinations. We conclude that, (1) although SNCA mutations are a rare cause of PD, it remains worth testing for new mutations in this gene; (2) a differential view of SNCA mutations and variants may allow important pathophysiologic inferences even beyond monogenic PD and is warranted in the context of clinical counseling. © 2013 Movement Disorder Society
Somatic alpha‐synuclein mutations in Parkinson's disease: Hypothesis and preliminary data
Authors: Proukakis Christos , Houlden Henry , Schapira Anthony H.
Published: May 2013

Alpha‐synuclein (SNCA) is crucial in the pathogenesis of Parkinson's disease (PD), yet mutations in the SNCA gene are rare. Evidence for somatic genetic variation in normal humans, also involving the brain, is increasing, but its role in disease is unknown. Somatic SNCA mutations, arising in early development and leading to mosaicism, could contribute to PD pathogenesis and yet be absent or undetectable in DNA derived from peripheral lymphocytes. Such mutations could underlie the widespread pathology in PD, with the precise clinical outcome dependent on their type and the timing and location of their occurrence. We recently reported a novel SNCA mutation (c.150T>G, p.H50Q) in PD brain‐derived DNA. To determine if there was mosaicism for this, a PCR and cloning strategy was used to take advantage of a nearby heterozygous intronic polymorphism. No evidence of mosaicism was found. High‐resolution melting curve analysis of SNCA coding exons, which was shown to be sensitive enough to detect low proportions of 2 known mutations, did not reveal any further mutations in DNA from 28 PD brain‐derived samples. We outline the grounds that make the somatic SNCA mutation hypothesis consistent with genetic, embryological, and pathological data. Further studies of brain‐derived DNA are warranted and should include DNA from multiple regions and methods for detecting other types of genomic variation. © 2013 The Authors. International Parkinson and Movement Disorder Society published by Wiley Periodicals, Inc.
Complex complete synchronization of two nonidentical hyperchaotic complex nonlinear systems
Authors: Mahmoud Emad E.
Published: May 2013

In this paper, we introduce the definition of complex complete synchronization (CCS) of hyperchaotic complex nonlinear systems that have not been introduced recently in the literature. This type of synchronization can study only for complex nonlinear systems. On the basis of Lyapunov function, a scheme is designed to achieve the CCS of two nonidentical hyperchaotic attractors of these systems. The effectiveness of the obtained results is illustrated by a simulation example. Numerical results are plotted to show state variables, modules errors, and phases errors of these hyperchaotic attractors after synchronization to prove that CCS is achieved. Copyright © 2013 John Wiley & Sons, Ltd.
Modulatory effects of yerba maté (Ilex paraguariensis) on the PI3K‐AKT signaling pathway
Authors: Arçari Demétrius Paiva , Santos Juliana Carvalho , Gambero Alessandra , Ferraz Lucio Fábio Caldas , Ribeiro Marcelo Lima
Published: May 2013

The aim of this study was to evaluate the effects of yerba maté (YM) extract on the phosphatidylinositol 3‐kinase (PI3K)‐AKT signaling pathway in vivo. The mice were introduced to either standard‐ or high‐fat diet (HFD). After 8 weeks on an HFD, mice were randomly assigned to one of the two treatment conditions, water or yerba maté extract at 1.0 g/kg. After treatment, glucose blood level and hepatic insulin response were evaluated. Liver tissue was examined to determine the mRNA levels using the PI3K‐AKT PCR array. The nuclear translocation of forkhead box O1 (FOXO1) was determined by an electrophoretic mobility‐shift assay. Our data demonstrated that yerba maté extract significantly decreased the final body weight, glucose blood levels, and insulin resistance of mice. Molecular analysis demonstrated that an HFD downregulated Akt2, Irs1, Irs2, Pi3kca, Pi3kcg, and Pdk1; after yerba maté treatment, the levels of those genes returned to baseline. In addition, an HFD upregulated Pepck and G6pc and increased FOXO1 nuclear translocation. The intervention downregulated these genes by decreasing FOXO1 nuclear translocation. The results obtained demonstrate for the first time the specific action of yerba maté on the PI3K‐AKT pathway, which contributed to the observed improvement in hepatic insulin signaling.
The 6‐minute walk test and other clinical endpoints in duchenne muscular dystrophy: Reliability, concurrent validity, and minimal clinically important differences from a multicenter study
Authors: McDonald Craig M. , Henricson Erik K. , Abresch R. Ted , Florence Julaine , Eagle Michelle , Gappmaier Eduard , Glanzman Allan M. ,   PTC124‐GD‐007‐DMD Study Group, Spiegel Robert , Barth Jay , Elfring Gary , Reha Allen , Peltz Stuart W.
Published: May 2013

Introduction: An international clinical trial enrolled 174 ambulatory males ≥5 years old with nonsense mutation Duchenne muscular dystrophy (nmDMD). Pretreatment data provide insight into reliability, concurrent validity, and minimal clinically important differences (MCIDs) of the 6‐minute walk test (6MWT) and other endpoints. Methods: Screening and baseline evaluations included the 6‐minute walk distance (6MWD), timed function tests (TFTs), quantitative strength by myometry, the PedsQL, heart rate–determined energy expenditure index, and other exploratory endpoints. Results: The 6MWT proved feasible and reliable in a multicenter context. Concurrent validity with other endpoints was excellent. The MCID for 6MWD was 28.5 and 31.7 meters based on 2 statistical distribution methods. Conclusions: The ratio of MCID to baseline mean is lower for 6MWD than for other endpoints. The 6MWD is an optimal primary endpoint for Duchenne muscular dystrophy (DMD) clinical trials that are focused therapeutically on preservation of ambulation and slowing of disease progression. Muscle Nerve 48: 357–368, 2013
Synergistic effect of DOPO immobilized silica nanoparticles in the intumescent flame retarded polypropylene composites
Authors: Dong Quanxiao , Liu Mingming , Ding Yanfen , Wang Feng , Gao Chong , Liu Peng , Wen Bin , Zhang Shimin , Yang Mingshu
Published: May 2013

The synergistic effect of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) immobilized silica (SiO2‐DOPO) nanoparticles with an intumescent flame retardant (IFR) on the flame retardancy of polypropylene (PP) was investigated by UL 94 vertical tests and limiting oxygen index (LOI) measurements. It was found that the PP/IFR composites (25 wt%) achieved the UL94 V0 grade and LOI increased to 32.1 with an incorporation of 1.0 wt% SiO2‐DOPO nanoparticles. Based on thermogravimetric analysis, scanning electronic microscopy and rheological analysis, it is speculated that three factors are mainly contributed to the improvement of the flame retardancy. First, the thermal stability of PP/IFR composites was improved by incorporating SiO2‐DOPO nanoparticles. Second, the presence of SiO2‐DOPO nanoparticles could induce the formation of a continuous char skin layer during combustion. The compact char layer could effectively impede the transport of bubbles and heat. Third, rheological analysis indicated that SiO2‐DOPO nanoparticles could increase viscosity of the PP/IFR composites, which was also benefited to increase flame retardancy. Copyright © 2013 John Wiley & Sons, Ltd.
Predictors of neoplastic disease in children with isolated pituitary stalk thickening
Authors: Robison Nathan J. , Prabhu Sanjay P. , Sun Pengling , Chi Susan N. , Kieran Mark W. , Manley Peter E. , Cohen Laurie E. , Goumnerova Liliana , Smith Edward R. , Scott R. Michael , London Wendy B. , Ullrich Nicole J.
Published: May 2013

Background

The significance of pituitary stalk thickening (PST) on magnetic resonance imaging (MRI) is often unclear. We evaluated presenting symptoms, MRI findings, clinical course, and outcome predictors of patients with PST.

Procedure

We used a computerized search of the medical record from 1995 to 2008 to identify patients with PST without pituitary mass on MRI. Baseline and follow‐up MRIs were reviewed in a blinded fashion. Relevant clinical data were abstracted.

Results

69 patients with reported PST and adequate imaging for review were identified; 42 met study criteria. Median age at first abnormal MRI was 13.6 years (range: 0.8–19.7); 43% were male. Median follow‐up was 3.4 years (range 0–12.8). Patients with diabetes insipidus (DI) were significantly more likely to have a neoplastic process than those without (P = 0.0008). Of 16 patients with DI, 8 (50%) had a neoplastic process, including germ cell tumor (n = 4), Langerhans cell histiocytosis (n = 3), and lymphoma (n = 1). Among patients with DI, 7 (44%) also developed anterior pituitary hormone dysfunction (APD), either at presentation or on pre‐biopsy follow‐up, including 6/8 patients with stalk neoplasm and only 1/8 patients with non‐neoplastic PST (P = 0.04). Twenty‐six patients presented without DI; none was found to have neoplasm of the stalk except one patient with craniopharyngioma. Progression of PST on follow‐up imaging was significantly associated with a subsequent neoplastic diagnosis (P = 0.04).

Conclusion

Patients with PST without DI are unlikely to have a neoplastic process. Among patients with DI, APD or progressive stalk increase over time are predictive of neoplasia. Pediatr Blood Cancer 2013;60:1630–1635. © 2013 Wiley Periodicals, Inc.
Proteomics in aortic aneurysm – What have we learnt so far?
Authors: Abdulkareem Nada , Skroblin Philipp , Jahangiri Marjan , Mayr Manuel
Published: May 2013

Aortic aneurysm is a deceptively indolent disease that can cause severe complications such as aortic rupture and dissection. In the normal aorta, vascular smooth muscle cells within the medial layer produce and sustain the extracellular matrix (ECM) that provides structural support but also retains soluble growth factors and regulates their distribution. Although the ECM is an obvious target to identify molecular processes leading to structural failure within the vessel wall, an in‐depth proteomics analysis of this important sub‐proteome has not been performed. Most proteomics analyses of the vasculature to date used homogenized tissue devoid of spatial information. In such homogenates, quantitative proteomics comparisons are hampered by the heterogeneity of clinical samples (i.e. cellular composition) and the dynamic range limitations stemming from highly abundant cellular proteins. An unbiased proteomics discovery approach targeting the ECM instead of the cellular proteome may decipher the complex, multivalent signals that are presented to cells during aortic remodelling. A better understanding of the ECM in healthy and diseased vessels will provide important pathogenic insights and has potential to reveal novel biomarkers.
Glycidyl Azide Polymer Crosslinked Through Triazoles by Click Chemistry: Curing, Mechanical and Thermal Properties
Authors: Reshmi Sasidhara K. , Vijayalakshmi K. P. , Thomas Deepthi , Arunan E. , Reghunadhan Nair C. P.
Published: May 2013

Glycidyl azide polymer (GAP) was cured through “click chemistry” by reaction of the azide group with bispropargyl succinate (BPS) through a 1,3‐dipolar cycloaddition reaction to form 1,2,3‐triazole network. The properties of GAP‐based triazole networks are compared with the urethane cured GAP‐systems. The glass transition temperature (Tg), tensile strength, and modulus of the system increased with crosslink density, controlled by the azide to propargyl ratio. The triazole incorporation has a higher Tg in comparison to the GAP‐urethane system (Tg−20 °C) and the networks exhibit biphasic transitions at 61 and 88 °C. The triazole curing was studied using Differential Scanning Calorimetry (DSC) and the related kinetic parameters were helpful for predicting the cure profile at a given temperature. Density functional theory (DFT)‐based theoretical calculations implied marginal preference for 1,5‐addition over 1,4‐addition for the cycloaddition between azide and propargyl group. Thermogravimetic analysis (TG) showed better thermal stability for the GAP‐triazole and the mechanism of decomposition was elucidated using pyrolysis GC‐MS studies. The higher heat of exothermic decomposition of triazole adduct (418 kJ ⋅ mol−1) against that of azide (317 kJ ⋅ mol−1) and better mechanical properties of the GAP‐triazole renders it a better propellant binder than the GAP‐urethane system.
Synthesis and Characterization of 1,5‐Dinitro‐2,6‐bis(trinitromethyl)‐3a,4a,7a,8a‐tetrahydro‐[1,4]dioxino[2,3‐d:5,6‐d′]diimidazole (DNTNDI)
Authors: Wu Minjie , Chen Shusen , Shu Qinghai , Li Lijie , Jin Shaohua
Published: May 2013

The polynitro imidazole derivative 1,5‐dinitro‐2,6‐bis(trinitromethyl)‐3a,4a,7a,8a‐tetrahydro‐[1,4]dioxino[2,3‐d:5,6‐d′]diimidazole (DNTNDI) was synthesized through nitration of 2‐(dinitromethylene)‐1H‐imidazol‐4‐ol in HNO3/Ac2O followed by cyclization of the di‐enol. It was characterized by NMR, IR, elemental analysis, and single‐crystal X‐ray diffraction analysis. Compound DNTNDI crystallizes in the orthorhombic space group P2(1)2(1)2(1). The thermal decomposition was studied with thermogravimetry/derivative thermogravimetry (TG/DTG) in a nitrogen atmosphere with a heating rate of 5 K min−1. The TG/DTG analysis indicated that DNTNDI has 97.64 % mass loss between 127 °C and 173 °C by undergoing exothermic decomposition. The density of DNTNDI was determined as 1.906 g cm−3 at 293 K with an Ultrapycno 1000 Pycnometer. The denotation velocity and denotation pressure of DNTNDI were calculated as 9325 m s−1 and 40 GPa by applying the LOTUSES (version 1.4) code, respectively. The oxygen balance of DNTNDI is 0 and its oxygen content amounts to 51.78 %, which is superior to that of new generation of chlorine‐free oxidizer ammonium dinitramide (ADN).
Molecular function prediction for a family exhibiting evolutionary tendencies toward substrate specificity swapping: Recurrence of tyrosine aminotransferase activity in the Iα subfamily
Authors: Muratore Kathryn E. , Engelhardt Barbara E. , Srouji John R. , Jordan Michael I. , Brenner Steven E. , Kirsch Jack F.
Published: May 2013

The subfamily Iα aminotransferases are typically categorized as having narrow specificity toward carboxylic amino acids (AATases), or broad specificity that includes aromatic amino acid substrates (TATases). Because of their general role in central metabolism and, more specifically, their association with liver‐related diseases in humans, this subfamily is biologically interesting. The substrate specificities for only a few members of this subfamily have been reported, and the reliable prediction of substrate specificity from protein sequence has remained elusive. In this study, a diverse set of aminotransferases was chosen for characterization based on a scoring system that measures the sequence divergence of the active site. The enzymes that were experimentally characterized include both narrow‐specificity AATases and broad‐specificity TATases, as well as AATases with broader‐specificity and TATases with narrower‐specificity than the previously known family members. Molecular function and phylogenetic analyses underscored the complexity of this family's evolution as the TATase function does not follow a single evolutionary thread, but rather appears independently multiple times during the evolution of the subfamily. The additional functional characterizations described in this article, alongside a detailed sequence and phylogenetic analysis, provide some novel clues to understanding the evolutionary mechanisms at work in this family. Proteins 2013. © 2013 Wiley Periodicals, Inc.
Ab initio folding of extended α‐helix: A theoretical study about the role of electrostatic polarization in the folding of helical structures
Authors: Lazim Raudah , Wei Caiyi , Sun Tiedong , Zhang Dawei
Published: May 2013

In this work, we report the ab initio folding of three different extended helical peptides namely 2khk, N36, and C34 through conventional molecular dynamics simulation at room temperature using implicit solvation model. Employing adaptive hydrogen bond specific charge (AHBC) scheme to account for the polarization effect of hydrogen bonds established during the simulation, the effective folding of the three extended helices were observed with best backbone RMSDs in comparison to the experimental structures over the helical region determined to be 1.30 Å for 2khk, 0.73 Å for N36 and 0.72 Å for C34. In this study, 2khk will be used as a benchmark case serving as a means to compare the ability of polarized (AHBC) and nonpolarized force field in the folding of an extended helix. Analyses conducted revealed the ability of the AHBC scheme in effectively folding the extended helix by promoting helix growth through the stabilization of backbone hydrogen bonds upon formation during the folding process. Similar observations were also noted when AHBC scheme was employed during the folding of C34 and N36. However, under Amber03 force field, helical structures formed during the folding of 2khk was not accompanied by stabilization thus highlighting the importance of electrostatic polarization in the folding of helical structures. Proteins 2013. © 2013 Wiley Periodicals, Inc.
Structure‐based engineering of streptavidin monomer with a reduced biotin dissociation rate
Authors: DeMonte Daniel , Drake Eric J. , Lim Kok Hong , Gulick Andrew M. , Park Sheldon
Published: May 2013

We recently reported the engineering of monomeric streptavidin, mSA, corresponding to one subunit of wild type (wt) streptavidin tetramer. The monomer was designed by homology modeling, in which the streptavidin and rhizavidin sequences were combined to engineer a high affinity binding pocket containing residues from a single subunit only. Although mSA is stable and binds biotin with nanomolar affinity, its fast off rate (koff) creates practical challenges during applications. We obtained a 1.9 Å crystal structure of mSA bound to biotin to understand their interaction in detail, and used the structure to introduce targeted mutations to improve its binding kinetics. To this end, we compared mSA to shwanavidin, which contains a hydrophobic lid containing F43 in the binding pocket and binds biotin tightly. However, the T48F mutation in mSA, which introduces a comparable hydrophobic lid, only resulted in a modest 20–40% improvement in the measured koff. On the other hand, introducing the S25H mutation near the bicyclic ring of bound biotin increased the dissociation half life (t½) from 11 to 83 min at 20°C. Molecular dynamics (MD) simulations suggest that H25 stabilizes the binding loop L3,4 by interacting with A47, and protects key intermolecular hydrogen bonds by limiting solvent entry into the binding pocket. Concurrent T48F or T48W mutation clashes with H25 and partially abrogates the beneficial effects of H25. Taken together, this study suggests that stabilization of the binding loop and solvation of the binding pocket are important determinants of the dissociation kinetics in mSA. Proteins 2013. © 2013 Wiley Periodicals, Inc.
Crystal structure of the cataract‐causing P23T γD‐crystallin mutant
Authors: Ji Fangling , Koharudin Leonardus M. I. , Jung Jinwon , Gronenborn Angela M.
Published: May 2013

Up to now, efforts to crystallize the cataract‐associated P23T mutant of human γD‐crystallin have not been successful. Therefore, insights into the light scattering mechanism of this mutant have been exclusively obtained from solution work. Here we present the first crystal structure of the P23T mutant at 2.5 Å resolution. The protein exhibits essentially the same overall structure as seen for the wild‐type protein. Based on our structural data, we confirm that no major conformational changes are caused by the mutation, and that solution phase properties of the mutant appear exclusively associated with cataract formation. Proteins 2013. © 2013 Wiley Periodicals, Inc.
Atomistic simulation of phonon and alloy limited hole mobility in Si1–xGex nanowires
Authors: Mehrotra Saumitra , Long Pengyu , Povolotskyi Michael , Klimeck Gerhard
Published: May 2013

magnified image

The role of alloy and phonon scattering is theoretically explored in 5 nm diameter SiGe nanowires at room temperature. Low‐field mobility calculations are performed by utilizing sp3d5ds*‐spin–orbit‐coupled tight binding model for electronic structure and Boltzmann transport formalism. Three different transport orientations 〈100〉, 〈110〉 and 〈111〉 are considered. Alloy scattering is found to play an important role in these Si1–xGex nanowires, leading to a characteristic ‘U’ shaped mobility curve as a function of alloy composition. It is concluded that to extract any advantage of higher Ge hole mobility by alloying, Ge% > 70% is needed. Furthermore, the 〈111〉 channel orientation exhibits the highest hole mobility while 〈100〉 has the lowest hole mobility for any given alloy composition. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metabolite profiling using liquid chromatography/quadrupole time‐of‐flight mass spectrometry for the identification of a suitable marker and target matrix of griseofulvin use in bovines
Authors: Tarbin J. A. , Fussell R. J.
Published: May 2013

RATIONALE

Griseofulvin is an antifungal agent with potential for misuse in food‐producing animals. Little is known about its metabolism in ruminants and hence what are suitable marker residues and target matrices for monitoring purposes.

METHODS

Tissues harvested from cattle treated with the antifungal agent griseofulvin were screened using liquid chromatography coupled to positive and negative electrospray ionization (ESI) quadrupole time‐of‐flight mass spectrometry (qToFMS) operated in ToF mode.

RESULTS

Twenty‐five possible metabolites were detected across all tissue types, but two isomeric compounds with accurate masses corresponding to loss of a methyl group from parent griseofulvin were considered to be the best candidate markers. Data from fragmentation experiments enabled a tentative assignment of the structures of the two compounds as 4‐demethylgriseofulvin and 6‐demethylgriseofulvin. These assignments were confirmed by matching the product ion spectra of incurred residues to those of custom synthesized reference standards.

CONCLUSIONS

4‐Demethyl‐ and 6‐demethylgriseofulvin have been identified as potential marker compounds of griseofulvin use in cattle. Liver was identified as the target matrix. Hair was shown to have potential for non‐invasive testing. © Crown copyright 2013. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
The use of a xylosylated plant glycoprotein as an internal standard accounting for N‐linked glycan cleavage and sample preparation variability
Authors: Walker S. Hunter , Taylor Amber D. , Muddiman David C.
Published: May 2013

RATIONALE

Traditionally, free oligosaccharide internal standards are used to account for variability in glycan relative quantification experiments by mass spectrometry. However, a more suitable internal standard would be a glycoprotein, which could also control for enzymatic cleavage efficiency, allowing for more accurate quantitative experiments.

METHODS

Hydrophobic, hydrazide N‐linked glycan reagents (both native and stable‐isotope labeled) are used to derivatize and differentially label N‐linked glycan samples for relative quantification, and the samples are analyzed by a reversed‐phase liquid chromatography chip system coupled online to a Q‐Exactive mass spectrometer. The inclusion of two internal standards, maltoheptaose (previously used) and horseradish peroxidase (HRP) (novel), is studied to demonstrate the effectiveness of using a glycoprotein as an internal standard in glycan relative quantification experiments.

RESULTS

HRP is a glycoprotein containing a xylosylated N‐linked glycan, which is unique from mammalian N‐linked glycans. Thus, the internal standard xylosylated glycan could be detected without interference to the sample. Additionally, it was shown that differences in cleavage efficiency can be detected by monitoring the HRP glycan. In a sample where cleavage efficiency variation is minimal, the HRP glycan performs as well as maltoheptaose.

CONCLUSIONS

Because the HRP glycan performs as well as maltoheptaose but is also capable of correcting and accounting for cleavage variability, it is a more versatile internal standard and will be used in all subsequent biological studies. Because of the possible lot‐to‐lot variation of an enzyme, differences in biological matrix, and variable enzyme activity over time, it is a necessity to account for glycan cleavage variability in glycan relative quantification experiments. Copyright © 2013 John Wiley & Sons, Ltd.
Disclosure control using partially synthetic data for large‐scale health surveys, with applications to CanCORS
Authors: Loong Bronwyn , Zaslavsky Alan M. , He Yulei , Harrington David P.
Published: May 2013

Statistical agencies have begun to partially synthesize public‐use data for major surveys to protect the confidentiality of respondents’ identities and sensitive attributes by replacing high disclosure risk and sensitive variables with multiple imputations. To date, there are few applications of synthetic data techniques to large‐scale healthcare survey data. Here, we describe partial synthesis of survey data collected by the Cancer Care Outcomes Research and Surveillance (CanCORS) project, a comprehensive observational study of the experiences, treatments, and outcomes of patients with lung or colorectal cancer in the USA. We review inferential methods for partially synthetic data and discuss selection of high disclosure risk variables for synthesis, specification of imputation models, and identification disclosure risk assessment. We evaluate data utility by replicating published analyses and comparing results using original and synthetic data and discuss practical issues in preserving inferential conclusions. We found that important subgroup relationships must be included in the synthetic data imputation model, to preserve the data utility of the observed data for a given analysis procedure. We conclude that synthetic CanCORS data are suited best for preliminary data analyses purposes. These methods address the requirement to share data in clinical research without compromising confidentiality. Copyright © 2013 John Wiley & Sons, Ltd.
A proposal to adjust the design approach for the diaphragm action of shear panels according to Schardt and Strehl in line with European regulations
Authors: Kathage Karsten , Lindner Joachim , Misiek Thomas , Schilling Sivo
Published: May 2013

In Germany the stiffness and resistance of diaphragms used for stabilizing members are traditionally calculated according to the Schardt and Strehl approach. Compared with the approach of Bryan and Davies given in the ECCS Recommendations, it does not take into account the flexibility of the connections. This paper shows how to amend Schardt and Strehl’s approach to include this flexibility, leading to more realistic values of diaphragm stiffness. The article also introduces new procedures for the calculation of the resistance, adopted from European standards and recommendations. Finally, both a test and an example taken from the literature are recalculated for comparison.
Romanian application of cold‐formed steel beams with screwed corrugated webs
Authors: Nagy Zsolt , Gîlia Lucian , Ballok Robert
Published: May 2013

Cold‐formed steel members are used in a wide variety of applications, both residential and industrial, due to their high strength‐to‐weight ratio. This paper introduces an innovative steel structural solution used in a portal frame configuration. The frame is made from cold‐formed steel beams with screwed corrugated web and SHS columns. Very good structural performance was achieved, proved by way of tests on such beams carried out previously at the Technical University of Cluj‐Napoca

A finite element analysis was carried out in Abaqus using available, accurate, test‐based calibrated FE models [1]. The same settings, mesh size, contacts, connectors and material definitions were used. Material stress‐strain curves obtained from coupon tests and a theoretical curve were determined; both types were used in the FE analysis for the definition of the material. A monotonic test will be performed on the proposed structural configuration. The paper concludes with advice on how to set up theoretical stress‐strain curves for design assisted by FEA of such kinds of girder. A case study presents one particular proposed structure, analysed by the authors and built for a warehouse application.
Cold‐formed steel beams with corrugated web and discrete web‐to‐flange fasteners
Authors: Dubina Dan , Ungureanu Viorel , Gîlia Lucian
Published: May 2013

Steel beams with corrugated webs represent a relatively new structural system that has emerged in the past two decades. The thin corrugated web results in a significant weight reduction in these beams compared with hot‐rolled or welded ones. In the initial solutions the flanges were made of flat plates welded to the sinusoidal web sheet, which required a specific welding technology. A new solution is proposed in this paper in which the beam is composed of a web of trapezoidal cold‐formed steel sheet and flanges of built‐up cold‐formed steel members (e.g. back‐to‐back lipped channels or angles or hat omega). Self‐drilling screws or spot welding are used for the connections between flanges and web. This paper summarizes the experimental and numerical investigations carried out at the CEMSIG Research Centre (http://cemsig.ct.upt.ro), “Politehnica” University of Timisoara, in order to evaluate and validate a new technological solution.
Design of cold‐formed steel members – comparison of EN 1993‐1‐3 and Direct Strength Method
Authors: Brune Bettina , Peköz Teoman
Published: May 2013

This paper compares the design concepts for cold‐formed steel members according to the European standard EN 1993‐1‐3 [22] and the Direct Strength Method (DSM) according to Appendix 1 of the AISI specification [3]. References to where the two approaches are described are followed by comparative analyses focusing on the fundamental design concepts, the design procedure, strength curves, opportunities and limits to their application. The paper points out similarities and differences, difficulties and opportunities. Channel section design examples are used to compare the different approaches. Current and ongoing research to extend the standards is summarized to show the future possibilities.
Bridge across the Lochkov Valley, Prague Ring Road – a strutted frame construction of a special kind
Authors: Anistoroaiei Christian , Heymel Ulrich , Jung Rolf , Sagner Michael Erik
Published: May 2013

This bridge, which connects Slivenec with Lahovice, is the project that completes the highway bypass south of Prague, in the Lochkov Valley. The bridge structure is 425.3 m long, 35 m wide and reaches a maximum height of almost 65 m. From both the architectural and engineering points of view, the bridge is an unusual design, with a curved composite structure supported by inclined concrete piers in the central span.
Steel superstructure saves concrete arch bridge over the River Ohře, Czech Republic
Authors: Korbelář Jaroslav , Kroupar Miroslav , Ryjáček Pavel , Schindler Jiří
Published: May 2013

This paper describes the design and construction of the unique widening of a concrete arch bridge over the River Ohře using a lightweight steel superstructure. The bridge reconstruction formed part of the wider reconstruction measures for road I/6, including its upgrade from a two‐ to a four‐lane highway, near Loket between Nové Sedlo and Sokolov in the north‐west of the Czech Republic. Details of the erection of the steel structure and the strengthening of the concrete arch and piers are also given.
Using spatial statistics and point‐pattern simulations to assess the spatial dependency between greater sage‐grouse and anthropogenic features
Authors: Gillan Jeffrey K. , Strand Eva K. , Karl Jason W. , Reese Kerry P. , Laninga Tamara
Published: May 2013

The greater sage‐grouse (Centrocercus urophasianus; hereafter, sage‐grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to the loss of habitat is the expanding human population with associated development and infrastructure. Our objective was to use a spatial‐statistical approach to assess the effect of roads, power transmission lines, and rural buildings on sage‐grouse habitat use. We used the pair correlation function (PCF) spatial statistic to compare sage‐grouse radiotelemetry locations in west‐central Idaho, USA, to the locations of anthropogenic features to determine whether sage‐grouse avoided these features, thus reducing available habitat. To determine significance, we compared empirical PCFs with Monte Carlo simulations that replicated the spatial autocorrelation of the sampled sage‐grouse locations. We demonstrate the implications of selecting an appropriate null model for the spatial statistical analysis by comparing results using a spatially random and a clustered null model. Results indicated that sage‐grouse avoided buildings by 150 m and power transmission lines by 600 m, because their PCFs were outside the bounds of a 95% significance envelope constructed from 1,000 iterations of a null model. Sage‐grouse exhibited no detectable avoidance of major and minor roads. The methods used here are broadly applicable in conservation biology and wildlife management to evaluate spatial relationships between species occurrence and landscape features. Our results can directly inform planning of infrastructure and other development projects in or near sage‐grouse habitat. © 2013 The Wildlife Society.
Conservation Planning in an Era of Change: State of the U.S. Prairie Pothole Region
Authors: Doherty Kevin E. , Ryba Adam J. , Stemler Casey L. , Niemuth Neal D. , Meeks William A.
Published: May 2013

We assessed attainability of landscape‐level conservation planning goals in the United States portion of the Prairie Pothole Region by summarizing and analyzing data on status, trends, and potential future of grasslands and wetlands. All published literature and new data analyses consistently indicate declines in grassland and wetland area. When we incorporated time as a conservation planning metric, the importance of seemingly small wetland (0.05–0.57%) and grassland (0.4–1.3%) annual loss rates became apparent. Moreover, we highlighted large differences in the amount of future grassland (30–67%) and wetland (47–93%) resulting from seemingly small changes in loss percentages. Our analyses clearly demonstrate that time, along with current status and trends of target habitat(s), must be incorporated when setting habitat conservation goals, otherwise goals may be unrealistic. Prairie Pothole Joint Venture (PPJV) partners protected an average of 0.20% of the 3.3 million ha extant wetlands and 0.26% of the 10.7 million ha extant grasslands/year. Consequently, PPJV partners cannot reach stated conservation goals given current habitat loss rates unless 1) increased funding is secured for land conservation, 2) landowner interest and acceptance of conservation programs remains high, and 3) wetland and grassland loss rates are decreased via public policy, particularly through agriculture programs, or other mechanisms. Otherwise, PPJV habitat conservation goals, and ultimately species population goals, will need to be reduced accordingly. Our comprehensive assessment may help the PPJV and other landscape‐level planning efforts discriminate between goals they would like to attain versus goals they are likely to achieve. © 2013 The Wildlife Society.
Extended Lymphadenectomy in Patients With Pancreatic Cancer Is Debatable
Authors: Sergeant Gregory , Melloul Emmanuel , Lesurtel Mickael , DeOliveira Michelle L. , Clavien Pierre‐Alain
Published: May 2013

Lymph node staging is one of the most important factors in determining the prognosis after resection of pancreatic ductal adenocarcinoma. Despite ongoing efforts to further refine lymph node staging, the debate on the extent of lymphadenectomy during pancreaticoduodenectomy is still open. The purpose of this review was to summarize the evidence about performing standard lymphadenectomy during curative resection of pancreatic cancer. All four prospective randomized controlled trials published concluded that extended lymphadenectomy does not contribute to better oncologic outcome for patients with adenocarcinoma of the pancreatic head. Indeed, one major drawback of extended lymphadenectomy is the higher risk of persistent postoperative diarrhea. No prospective randomized studies could be found on the role of extended lymphadenectomy in patients with adenocarcinoma of the corpus and tail. Based on current evidence there is no indication that extended lymphadenectomy should be performed routinely during resection of pancreatic cancer.
Patients’ Preferences on Information and Involvement in Decision Making for Gastrointestinal Surgery
Authors: Uldry Emilie , Schäfer Markus , Saadi Alend , Rousson Valentin , Demartines Nicolas
Published: May 2013

Background

The relationship between physicians and patients has undergone important changes, and the current emancipation of patients has led to a real partnership in medical decision making. The present study aimed to assess patients’ preferences on different aspects of decision making during treatment and potential complications, as well as the amount and type of preoperative information wanted before visceral surgery.

Methods

This was a prospective non‐randomized study based on a questionnaire given to 253 consecutive patients scheduled for elective gastrointestinal surgery.

Results

In considering surgical complications or treatment in the intensive care unit, 64 % of patients wished to take an active role in any medical decisions. The respective figures for cardiac resuscitation and treatment limitations were 89 and 60 %. As for information, 73, 77, and 47 % of patients wish detailed information, information on a potential ICU hospitalization, and knowledge of cardiac resuscitation, respectively. Elderly and low‐educated patients were significantly less interested in shared medical decision making (p = 0.003 and 0.015), and in receiving information (p = 0.03 and 0.05). Similarly, involvement of the family in decision making was significantly less important to elderly and male patients (p = 0.05 and 0.03, respectively). Neither the type of operation (minor or major) nor the severity of disease (malignancies versus non‐malignancies) was a significant factor for shared decision making, information, or family involvement.

Conclusions

The vast majority of surgical patients clearly want to get adequate preoperative information about their disease and the planned treatment. They also consider it crucial to be involved in any kind of decision making for treatment and complications. For most patients, the family role is limited to supporting the treating physicians if the patient is unable to participate in decision making.
Early Enteral Nutrition Prevents Intra‐abdominal Hypertension and Reduces the Severity of Severe Acute Pancreatitis Compared with Delayed Enteral Nutrition: A Prospective Pilot Study
Authors: Sun Jia‐kui , Li Wei‐qin , Ke Lu , Tong Zhi‐hui , Ni Hai‐bin , Li Gang , Zhang Lu‐yao , Nie Yao , Wang Xin‐ying , Ye Xiang‐hong , Li Ning , Li Jie‐shou
Published: May 2013

Background

To investigate the effects of early enteral nutrition (EEN) on intra‐abdominal pressure (IAP) and disease severity in patients with severe acute pancreatitis (SAP).

Methods

Enteral nutrition (EN) was started within 48 h after admission in the EEN group and from the 8th day in the delayed enteral nutrition (DEN) group. The IAP and intra‐abdominal hypertension (IAH) incidence were recorded for 2 weeks. The caloric intake and feeding intolerance (FI) incidence were recorded daily after EN was started. The severity markers and clinical outcome variables were also recorded.

Results

Sixty patients were enrolled to this study. No difference about IAP was found. The IAH incidence of the EEN group was significantly lower than that of the DEN group from the 9th day (8/30 versus 18/30;P= 0.009) after admission. The FI incidence of the EEN group was higher than that of the DEN group during the initial 3 days of feeding (25/30 versus 12/30;P= 0.001; 22/30 versus 9/30;P= 0.001; 15/30 versus 4/30;P= 0.002). Patients with an IAP <15 mmHg had lower FI incidence than those with an IAP ≥15 mmHg on the 1st day (20/22 versus 17/38;P< 0.001), the 3rd day (11/13 versus 8/47;P< 0.001), and the 7th day (3/5 versus 3/55;P= 0.005) of feeding. The severity markers and clinical outcome variables of the EEN group were significantly improved.

Conclusions

Early enteral nutrition did not increase IAP. In contrast, it might prevent the development of IAH. In addition, EEN might be not appropriate during the initial 3–4 days of SAP onset. Moreover, EN might be of benefit to patients with an IAP <15 mmHg. Early enteral nutrition could improve disease severity and clinical outcome, but did not decrease mortality of SAP.