bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactivity of (Dicarboxamide)MII–OH (M = Cu, Ni) Complexes – Reaction with Acetonitrile to Yield MII–Cyanomethides
Authors: Tehranchi Jacqui , Donoghue Patrick J. , Cramer Christopher J. , Tolman William B.
Published: May 2013

The complexes (Bu4N)(LMeMII–OH) (LMe = 2,6‐dimethylphenyl‐substituted pyridine(dicarboxamide); M = Cu or Ni) react with CH3CN to yield (Bu4N)(LMeM–CH2CN) cyanomethide complexes, which were fully characterized, including by X‐ray crystallography. These conversions contrast with the usual reactions of metal hydroxide complexes with nitriles, which typically involve attack at the nitrile carbon atom and formation of amides or carboxylic acids. Kinetic studies (M = Cu) revealed a first‐order dependence on the complex and a kinetic isotope effect [k(CH3CN)/k(CD3CN)] of 4. Various mechanisms involving either intra‐ or intermolecular deprotonation steps are proposed. In addition, (Bu4N)(LMeCu–OH) was oxidized by ferrocenium hexafluorophospate (FcPF6) to a proposed CuIII complex LMeCuOH at low temperature, and comparisons of its stability and reactivity with dihydroanthracene were drawn to its previously described congener with isopropyl substituents on the phenyl rings of the supporting ligand. The cyanomethide complex (Bu4N)(LMeCu(CH2CN)) was also reversibly oxidized both electrochemically (E1/2 = –0.345 V vs. Fc/Fc+) and chemically (FcPF6, –25 °C). The product was formulated as LMeCuIII(CH2CN), a new CuIII–alkyl complex relevant to such species proposed during copper‐catalyzed organic reactions.
Efficient Consecutive Four‐Component Synthesis of 5‐Acylpyrid‐2‐ones Initiated by Copper‐Free Alkynylation
Authors: Nordmann Jan , Breuer Natascha , Müller Thomas J. J.
Published: May 2013

A one‐pot, consecutive, four‐component synthesis of 5‐acylpyrid‐2‐ones initiated by Pd/cataCXium® ABn catalysis proceeds under mild reaction conditions and in good yields, with a broad scope of three points of diversity. This sequence is superior to the initially proposed Pd/Cu‐catalyzed version because all four components can be employed in close to stoichiometric amounts.
Tandem Iminium/Copper Catalysis: Highly Enantioselective Synthesis of α,β‐Disubstituted Aldehydes
Authors: Kim Ju‐Hye , Park Eun‐Jin , Lee Hwa‐Jung , Ho Xuan‐Huong , Yoon Hyo‐Sang , Kim Pilsoo , Yun Hoseop , Jang Hye‐Young
Published: May 2013

With the goal of synthesizing biologically and synthetically valuable products under environmentally benign and economic conditions, an asymmetric organocatalytic reaction was combined with a copper catalytic reaction. This iminium/copper catalysis allowed highly optically active α,β‐disubstituted aldehydes to be synthesized with good yields in one‐pot fashion. The β‐substitution took place through iminium‐catalyzed Michael addition of nitromethane or diethyl malonate to the α,β‐unsaturated aldehydes, followed by copper‐assisted addition of TEMPO (2,2,6,6‐tetramethylpiperidin‐1‐yloxyl) at the aldehyde α‐position. An iminium/copper‐catalyzed tandem addition product was converted into a 3,4,5‐trisubstituted piperidine for X‐ray crystallographic analysis.
Determination of the Natural Dissolved Concentration of Zirconium in Seawater by Adsorptive Stripping Voltammetry
Authors: Schneider Alexandre B. , Nascimento Paulo C. , Bohrer Denise , de Carvalho Leandro M. , Guarda Ananda , Dias Daiane , Koschinsky Andrea
Published: May 2013

A voltammetric method was developed for zirconium determination as Zr(IV)‐cupferron‐oxalate‐diphenylguanidine complex based on adsorptive accumulation at the HMDE (Epeak=−0.95 V). The supporting electrolyte was a mixture of acetate/acetic acid (pH 4.6) and ammonium acetate (pH 5.7) solutions. Eads=−0.6 V (vs. Ag/AgCl), tads=400 s, 10 mV s−1 scan rate, and DP mode were the main parameters. The linear range was 0.033 to 3.3×10−9 mol L−1, and the LOD and LOQ (tads=400 s) were 0.77 and 1.6×10−11 mol L−1, respectively. The method was adequate for seawater samples, although not sufficiently sensitive for surface waters.
Development of a high‐throughput glycoanalysis method for the characterization of oligosaccharides in human milk utilizing multiplexed capillary gel electrophoresis with laser‐induced fluorescence detection
Authors: Kottler Robert , Mank Marko , Hennig René , Müller‐Werner Beate , Stahl Bernd , Reichl Udo , Rapp Erdmann
Published: May 2013

During the last decade, enormous progress regarding knowledge about composition and properties of human milk (HM) has been made. Besides nutrition, the three macro‐nutrients: proteins, lipids, and carbohydrates combine a large variety of properties and functions. Especially, complex oligosaccharides emerge as important dietary factors during early life with multiple functions. The characterization of these HM oligosaccharides (HMOS) within the total carbohydrate fraction is prerequisite to understand the relationship between milk composition and biological effects. Therefore, extended studies of large donor cohorts and thus, new high‐throughput glycoanalytical methods are needed. The developed method comprises sample preparation, as well as analysis of HMOS by multiplexed CGE with LIF detection (xCGE‐LIF). Via a respective database the generated “fingerprints” (normalized electropherograms) could be used for structural elucidation of HMOS. The method was tested on HM samples from five different donors, partly sampled as a series of lactation time points. HMOS could be easily identified and quantified. Consequently, secretor and Lewis status of the donors could be determined, milk typing could be performed and quantitative changes could be monitored along lactation time course. The developed xCGE‐LIF based “real” high‐throughput HMOS analysis method enables qualitative and quantitative high‐performance profiling of the total carbohydrate fraction composition of large sets of samples.
Norfloxacin drug induces reproductive toxicity and alters androgen receptor gene expression in testes and cloacal gland of male Japanese quail (Coturnix Japonica)
Authors: Singh Ram P. , Sastry Kochiganti V.H. , Dubey Pawan K. , Agrawal Radha , Singh Renu , Pandey Nitin Kumar , Mohan Jag
Published: May 2013

In an attempt to investigate the reproductive toxicity of norfloxacin in Japanese quail, male quail were given norfloxacin at 20 mg/kg body weight for 14 d. Then reproductive function and androgen receptor (AR) gene expression was examined in treated and control birds. The results of the present study indicate that fertility, cloacal gland area, sperm concentration, and serum testosterone were reduced significantly (p < 0.05) on day 14 in the norfloxacin-treated birds. Upregulation (p < 0.05) of AR mRNA was also seen in the testes on the 14th d of treatment. A trend toward downregulation of AR mRNA was seen in the cloacal gland of norfloxacin-treated birds. Histological observations revealed that norfloxacin induces cellular atrophy in testes and changes in glandular tissue in the cloacal gland. The results of the present study demonstrate that norfloxacin induces testicular toxicity in Japanese quail. Environ Toxicol Chem 2013;32:2134–2138. © 2013 SETAC
Can a sheet‐like low‐velocity region form an elongated Large Igneous Province?
Authors: Namiki Atsuko , Sueyoshi Kenta , Takeuchi Nozomu
Published: May 2013

High‐resolution tomography of the lower mantle has revealed the existence of another chemically distinct region with low‐velocity and a sheet‐like structure beneath the western Pacific. On the other hand, Large Igneous Provinces (LIPs) sometimes have elongated shapes. If a sheet‐like upwelling reaches the Earth's surface while maintaining its shape, an elongated LIP may form. In order to test this hypothesis, we perform a series of experiments and investigate the stability of a buoyant sheet. The experimental results show that the buoyant fluid accumulates at the top of the sheet to form a buoyant cylinder. The gravitational instability divides the cylinder into several plume heads. We develop a model to explain the growth of the buoyant cylinder and the time scale until instability begins. Our model shows that a thin sheet‐like upwelling with a width of 200 km, a small density difference from the ambient mantle, 10 kg m−3, and a high supply rate of buoyant fluid, 0.1 m yr−1, can reach the Earth's surface while maintaining its shape. We thus infer that LIPs with an elongated shape can be generated by sheet‐like upwellings. The width of the observed sheet‐like low‐velocity region beneath the western Pacific is 500 km and is marginally sufficient to form an elongated LIP.
Endogenous parathyroid hormone–related protein compensates for the absence of parathyroid hormone in promoting bone accrual in vivo in a model of bone marrow ablation
Authors: Zhu Qi , Zhou Xichao , Zhu Min , Wang Qian , Goltzman David , Karaplis Andrew , Miao Dengshun
Published: May 2013

To assess the effect of hypoparathyroidism on osteogenesis and bone turnover in vivo, bone marrow ablation (BMXs) were performed in tibias of 8-week-old wild-type and parathyroid hormone–null (PTH−/−) mice and newly formed bone tissue was analyzed from 5 days to 3 weeks after BMX. At 1 week after BMX, trabecular bone volume, osteoblast numbers, alkaline phosphatase-positive areas, type I collagen-positive areas, PTH receptor–positive areas, calcium sensing receptor–positive areas, and expression of bone formation–related genes were all decreased significantly in the diaphyseal regions of bones of PTH−/− mice compared to wild-type mice. In contrast, by 2 weeks after BMX, all parameters related to osteoblastic bone accrual were increased significantly in PTH−/− mice. At 5 days after BMX, active tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts had appeared in wild-type mice but were undetectable in PTH−/− mice, Both the ratio of mRNA levels of receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) and TRAP-positive osteoclast surface were still reduced in PTH−/− mice at 1 week but were increased by 2 weeks after BMX. The expression levels of parathyroid hormone–related protein (PTHrP) at both mRNA and protein levels were upregulated significantly at 1 week and more dramatically at 2 weeks after BMX in PTH−/− mice. To determine whether the increased newly formed bones in PTH−/− mice at 2 weeks after BMX resulted from the compensatory action of PTHrP, PTH−/−PTHrP+/− mice were generated and newly formed bone tissue was compared in these mice with PTH−/− and wild-type mice at 2 weeks after BMX. All parameters related to osteoblastic bone formation and osteoclastic bone resorption were reduced significantly in PTH−/−PTHrP+/− mice compared to PTH−/− mice. These results demonstrate that PTH deficiency itself impairs osteogenesis, osteoclastogenesis, and osteoclastic bone resorption, whereas subsequent upregulation of PTHrP in osteogenic cells compensates by increasing bone accrual. © 2013 American Society for Bone and Mineral Research
Accuracy and tractability of a kriging model of intramolecular polarizable multipolar electrostatics and its application to histidine
Authors: Kandathil Shaun M. , Fletcher Timothy L. , Yuan Yongna , Knowles Joshua , Popelier Paul L. A.
Published: May 2013

We propose a generic method to model polarization in the context of high‐rank multipolar electrostatics. This method involves the machine learning technique kriging, here used to capture the response of an atomic multipole moment of a given atom to a change in the positions of the atoms surrounding this atom. The atoms are malleable boxes with sharp boundaries, they do not overlap and exhaust space. The method is applied to histidine where it is able to predict atomic multipole moments (up to hexadecapole) for unseen configurations, after training on 600 geometries distorted using normal modes of each of its 24 local energy minima at B3LYP/apc‐1 level. The quality of the predictions is assessed by calculating the Coulomb energy between an atom for which the moments have been predicted and the surrounding atoms (having exact moments). Only interactions between atoms separated by three or more bonds (“1, 4 and higher” interactions) are included in this energy error. This energy is compared with that of a central atom with exact multipole moments interacting with the same environment. The resulting energy discrepancies are summed for 328 atom–atom interactions, for each of the 29 atoms of histidine being a central atom in turn. For 80% of the 539 test configurations (outside the training set), this summed energy deviates by less than 1 kcal mol−1. © 2013 Wiley Periodicals, Inc.
Polyploidy Is Genetic Hence May Cause Non‐Adaptive Radiations, Whereas Pseudopolyploidy Is Genomic Hence May Cause Adaptive Non‐Radiations
Authors: GORELICK ROOT , OLSON KRYSTLE
Published: May 2013

There are two ways eukaryotes double number of chromosomes: (1) whole genome duplication (polyploidy), in which all nuclear DNA is replicated, and (2) karyotypic fission (pseudopolyploidy), in which all chromosomes are physically bifurcated. We contrast polyploidy with pseudopolyploidy, highlighting when it is crucial to look at genetic vs. genomic levels. We review history of pseudopolyploidy, including recent mechanisms by which chromosomal bifurcation may occur and outline methods for detecting such genomic changes. We then delve into the evolutionary implications, with particular focus on adaptive potential, of these two forms of doubling chromosome numbers. We address the common assertion that polyploidy induces adaptive radiations, which contains three fallacies. First, while polyploidy causes quantum speciation, evolutionary theory implies that these radiations should be non‐adaptive. Polyploidy causes reproductive isolation, minute effective population sizes, and increased mutation rates, which all imply a diminished role for selection. Second, due to lack of karyotyping in recent decades and lack of distinction between genomic and genetic effects, it is usually impossible to detect pseudopolyploids. Third, pseudopolyploids lack minority cytotype exclusion because they readily backcross with their progenitors, which thereby means no reproductive isolation for newly formed pseudopolyploids. Pseudopolyploidy will thereby not result in radiations until pseudopolyploid descendants undergo subsequent chromosome rearrangements or grow new centromeres. Pseudopolyploids may have a modest selective advantage over their progenitors due to diminished linkage disequilibrium. Thus, pseudopolyploidy may induce adaptive non‐radiations. We encourage a renaissance of karyotyping to distinguish between these two mechanisms and a renaissance in genomic perspectives in evolution. J. Exp. Zool. (Mol. Dev. Evol.) 320B:286–294, 2013. © 2013 Wiley Periodicals, Inc.
Correlation of late gadolinium enhancement MRI and quantitative T2 measurement in cardiac sarcoidosis
Authors: Yang Yuesong , Safka Katherine , Graham John J. , Roifman Idan , Zia Mohammad I. , Wright Graham A. , Balter Meyer , Dick Alexander J. , Connelly Kim A.
Published: May 2013

Purpose

To investigate the potentially improved detection and quantification of cardiac involvement using novel late‐gadolinium‐enhancement (LGE) cardiac magnetic resonance imaging (MRI) and quantitative T2 measurement to achieve better myocardial tissue characterization in systemic sarcoidosis.

Materials and Methods

Twenty‐eight patients with systemic sarcoidosis underwent a cardiac magnetic resonance imaging (CMR) study on a 1.5T system. Precontrast CMR included left ventricular (LV) and right ventricular (RV) function and quantitative T2 measurement. Postcontrast LGE‐MRI included inversion‐recovery fast‐gradient‐echo (IR‐FGRE) and multicontrast late‐enhancement imaging (MCLE).

Results

LV functional parameters were normal in all patients (LVEF = 61.2 ± 8.5%) including with cardiac involvement (LVEF = 59.4 ± 12.1%) and without (LVEF = 61.7 ± 7.5%) while the average RV function was comparatively decreased (RVEF = 48.0 ± 6.6%, P < 0.0001). 21.4% of patients had cardiac involvement showing patchy or multiple focal hyperenhancement patterns in LV free wall, papillary muscles (PM), or interventricular septum. In two cases with PM involvement, the PM abnormal LGE foci were only observed on MCLE. For precontrast T2 measurements, a significantly decreased T2 measurement was observed in regions demonstrating LGE, compared to the LGE‐negative group (focal LGE‐positive regions vs. negative: 40.0 ± 2.4 msec vs. 53.0 ± 2.6 msec, P < 0.0001).

Conclusion

LGE‐MRI can identify cardiac involvement in systemic sarcoidosis. MCLE might be more sensitive at detecting subtle myocardial lesion. The decreased T2 observed in cardiac sarcoid may reflect its inactive phase, thus might provide a noninvasive method for monitoring disease activity or therapy. J. Magn. Reson. Imaging 2014;39:609–616. © 2013 Wiley Periodicals, Inc.
Mass spectrometric and peptide chip characterization of an assembled epitope: analysis of a polyclonal antibody model serum directed against the Sjøgren/systemic lupus erythematosus autoantigen TRIM21
Authors: Al‐Majdoub M. , Koy C. , Lorenz P. , Thiesen H.‐J. , Glocker M. O.
Published: May 2013

We demonstrate the development of a mass spectrometry‐based epitope‐mapping procedure in combination with Western blot analysis that works also with antigens that are insoluble in nondenaturing buffers consuming minute amounts of antigen (approximately 200 pmol) and antibody (approximately 15 pmol), respectively. A polyclonal anti‐TRIM21 rabbit antibody serum is applied as a model serum for future patient analyses to set up the system. The major epitope that is recognized by the anti‐TRIM21 serum spans the central TRIM21 region LQ‐ELEKDEREQLRILGE‐KE, showing that immunization with a 139‐amino acid residue long peptide resulted in a ‘monospecific’ polyclonal antibody repertoire. Protein structure investigations, secondary structure predictions, and surface area calculations revealed that the best matching partial sequence to fulfill all primary and secondary structure requirements was the four amino acid spanning motif ‘L–E–Q–L’, which is present in both the sequential and the α‐helical peptide conformation. Peptide chip analyses confirmed the mass spectrometric results and showed that the peptide chip platform is an appropriate method for displaying secondary structure‐relying epitope conformations. As the same secondary structures are present in vivo, patient antibody screening, e.g., to identify subgroups of patients according to distinct epitope antibody reactivities, is feasible. Copyright © 2013 John Wiley & Sons, Ltd.
Chlorobenzene degradation by Bacillus sp. TAS6CB: A potential candidate to remediate chlorinated hydrocarbon contaminated sites
Authors: Vyas Trupti K. , Murthy Shruti R.
Published: May 2013

Chlorobenzenes (CB) are very commonly detected in ecosystems notably in the atmosphere, freshwater, sediments, and in urban sewage. They may contaminate ecosystems via the direct discharge of solid and liquid waste or through atmospheric volatilization. In the present study, CB degrading organisms were isolated from contaminated sites and screened for their effectiveness to degrade it. Isolates 6CB efficiently degrade CB. Isolate was identified by 16SrDNA and identified as Bacillus sp. TAS6CB. The cells showed positive chemotaxis towards CB, catechol, and salicylic acid indicates their potential for degradation of xenobiotic compounds. Degradation commence with production of chlorobenzene dioxygenase and further conversion into chlorocatechol, a central intermediate of chlorinated aromatic metabolism. Degradation rates were further enhanced by biosurfactant production as detected and confirmed by TLC analysis. Intermediate metabolites chlorocatechol and cis,cis‐muconic acid, produced during the CB degradation were confirmed by UV scanning, HPLC and GC–MS analysis. Phytotoxicity study showed 40% of phytotoxicity decreased after 48 h of incubation by isolate. Thus, isolate can be used to remediate CB contaminated sites effectively.
Molecular cloning of a laccase gene from Ganoderma lucidum and heterologous expression in Pichia pastoris
Authors: You Lin‐Feng , Liu Zhi‐Ming , Lin Jun‐Fang , Guo Li‐Qiong , Huang Xun‐Liu , Yang Hai‐Xing
Published: May 2013

A genomic laccase gene and cDNA were cloned from the white‐rot fungi Ganoderma lucidum TR6. The genomic laccase gene contained 2086 bp with nine introns. The laccase cDNA had an open reading frame of 1563 bp. The deduced mature protein consisted of 520 amino acids. Both the genomic laccase gene and cDNA were expressed in the Pichia pastoris GS115. Laccase activities could be detected in transformants with laccase cDNA but not in transformants with genomic laccase gene. The highest activity value reached 685.8 U L−1. The effects of temperature, pH and nitrogen source on laccase expression in P. pastoris were analyzed. The recombinant laccase was purified and the molecular mass was 73.4 KDa, a little bigger than native laccase. The optimal pH and temperature were specific at pH 3.5 and special range from 60 to 90 °C. The laccase was stable at pH 7.0 and temperature range of 20–30 °C. The Km and Vm values of this recombinant laccase for ABTS were 0.521 mM and 19.65 mM min−1, respectively.
Insights into the Ring‐Expansion Polymerization of Thiiranes with 2,4‐Thiazolidinedione
Authors: Schuetz Jan‐Hendrik , Sandbrink Lennart , Vana Philipp
Published: May 2013

The behavior of the ring‐expansion homopolymerization of 2 (phenoxymethyl)thiirane (PMT) and propylene sulfide (PS), respectively, with thiazolidine‐2,4‐dione (TZD) as a cyclic initiator is investigated. The polymerizations show steadily growing molar masses with increasing monomer conversions. In addition, reversible merging reactions between rings are observed, with up to six merged macrocycles formed. The degree of merging is strongly dependent on the initial monomer concentration, whereas temperature has only a small impact. Under optimized conditions, ring‐poly(PMT) polymer with values of Mn up to 50 250 g mol−1 and dispersities down to 1.11 can be synthesized. DSC and ESI‐MS measurements of the novel ring‐poly(PS) prove the formation of ring polymer having topological purity above 95%.

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Thermal Properties of PMMA on Silica Using Temperature‐Modulated Differential Scanning Calorimetry
Authors: Khatiwada Bal K. , Hetayothin Boonta , Blum Frank D.
Published: May 2013

The behavior of an amorphous polymer, poly(methyl methacrylate) (PMMA), adsorbed on silica was studied using temperature‐modulated differential scanning calorimetry (TMDSC). A two‐component model, based on loosely‐bound polymer with a glass transition temperature (Tg) (similar to that of the bulk polymer) and a tightly‐bound polymer (with a Tg higher than that of the loosely‐bound polymer) was used to interpret the thermograms. Increased sensitivity allowed the two transitions in the thermograms to be quantified much more accurately than in previous work. Linear regression analysis of the ratio of the area under two transitions with composition yielded the amount of tightly bound polymer, m″B = 1.21 +/− 0.21 mg PMMA/m2silica. Two methods of analyzing the thermograms, fitting with a Gaussian‐Lorentzian (GL) cross distribution function and perpendicular drop (PD) method, yielded similar results for the amount of tightly‐bound polymer on the surfaces with the GL method having a statistically better fit to the model. The ratio of heat capacity increments of loosely bound and tightly bound polymer, ΔCpA/ΔCpB, around the glass transition, indicated the relative mobility of the two components. It was found that the ΔCpA was aboutthree times as large as that of ΔCpB suggesting that the tightly bound polymer had a much smaller change in mobility through glass transition region.
Preparation and Characterization of Zr (IV) Doped Polyaniline for Supercapacitor Application
Authors: Giri Soumen , Ghosh Debasis , Mandal Avinandan , Das Chapal Kumar
Published: May 2013

In the present paper, we have reported the in‐situ chemical synthesis and characterizations of polyaniline with both HCl and Zirconium (IV). The polyaniline was synthesized by electrochemical oxidative polymerization of aniline monomer using ammonium peroxodisulphate as oxidizing agent. The doped PANI was charecterized by Ultraviolet‐Visible (UV‐Visible), Fourier transfrom infrared (FT‐IR), Thermo gravimetric analysis (TGA), Field emission scanning electon microscopy (FESEM) and Transmission electron microscopy (TEM) analysis. FESEM and TEM study showed that the morphology of PANI changed after doping with Zirconium salt. All electrochemical charcterizations were peforrmed by conventional three electrode system where glassy carbon electrode, platinium wire and stanadard calomel electrode (SCE) were used as working electrode, counter electrode and reference electrode, respectively. The cyclic voltammtry study(CV), electrochemical impedance spectroscopy(EIS)study and charge discharge test (CCD) of Zr doped PANI showed better performance and higher specific capacitance of 323 F/g compareed to HCl doped PANI.
Micromechanical Studies of Styrenic Block Copolymer Blends Based Nanocomposites
Authors: Henning Sven , Adhikari Rameshwar , Borreck Sven , Buschnakowski Matthias , Michler Goerg H.
Published: May 2013

In this work, using different microscopic techniques, and tensile testing, we investigate the micro‐deformation processes in the blends and nanocomposites based on a highly asymmetric star shaped polystyrene/polybutadiene block copolymer. As one of the blends and composites components, we use general purpose polystyrene (GPPS) and organophilic modified boehmite nanoparticles, respectively. The emphasis has been put on the analysis of the impact of morphology on the micromechanical behaviour of the blends. After mixing with standard polystyrene, these copolymers form typical droplet morphologies. The incorporation of boehmite nanofiller with different types of surfactants into the binary blends was found to affect the micromechanical properties in various ways, the most optimum morphology for the enhancement of the toughness being the finest dispersion of the spherical nanoparticles less than 50 nm in diameter which initiated intense plastic deformation of the blend.
Conical tube hydro‐forming design of automotive instrument panel beams using computer aided engineering
Authors: Kim K. J. , Kim K. , Kang Y. , Park J.‐H.
Published: May 2013

The hydroforming technology has been spreaded dramatically in automotive industry during the last 10 years. The advantages of hydroforming (less thinning, a more efficient manufacturing process, etc.) can, for instance, be combined with the high strength of extra high strength steels, which are usually less formable, to produce structural automotive components, which exhibit lower weight and improved service performance. Design and production of tubular components require knowledge about the tube material and forming behavior during hydroforming and how the hydroforming operation itself should be controlled. These issues are studied analytically in the present paper. In this study, the whole process of automotive IP (instrument panel) beam parts development by conical tube hydroforming using a steel material having a tensile strength of 370 MPa grade is presented. At the part design stage, it requires feasibility study and process design aided by CAE (computer aided engineering) to confirm the hydroformability in details. Effects of parameters such as geometry shape in automotive IP parts on the hydroforming process were carefully investigated. The overall feasibility of hydroformable IP parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of the tube material on every forming step such as pre‐bending, preforming and hydroforming. In addition, all the components of the prototyping tool are designed and the interference with the press is examined from the point of geometry and thinning.
Strength capacity of simply supported circular concrete slab
Authors: Matešan D. , Radnić J. , Grgić N. , Baloević G.
Published: May 2013

The results of an experimentally tested simply supported circular concrete slab were presented first. The slab was loaded with a point load at mid‐span. The effect of four different reinforcement arrangements on its limit strength capacity and deflection was analyzed. A previously developed numerical model of the authors for analysis of ordinary reinforced and prestressed concrete slabs and shells was tested based on the obtained experimental results. Then, the limit strength capacity of the circular concrete slab of a cement silo, loaded with a uniform load, was numerically analyzed. It was concluded that the limit strength capacity and deflection of a simply supported circular concrete slab depends significantly on its reinforcement arrangement.
On the fragility of fiberglass reinforced polyester pipe in contact with hydrofluoric acid (HF)
Authors: Leta F. R. , Mainier F. B.
Published: May 2013

The use of fiberglass reinforced plastics (FPR), manufactured in polyester or epoxy, has been explored by a number of petroleum offshore operators as an alternative to steel, principally due to the resistance to corrosion of these materials. In addition, their relative light weight facilitates handling and installation that is particularly beneficial for retrofit applications. The structural integrity of traditional FRP components in corrosive environments is usually dependent on the integrity of a corrosion‐resistant barrier, such as a resin‐rich layer containing corrosion resistant glass fibers. In this paper, the case study investigated by the authors provide the example of a failure that can occur in acidizing operations with mixtures of hydrofluoric acid and hydrochloric acid. Therefore, fiberglass is susceptible to damage modes such as resin cracking, fiber breakage, delamination and chemical corrosion. The paper illustrates the attack of hydrofluoric acid (HF) that penetrates in the porosities or cracks and attacks the fiberglass (SiO2), resulting, consequently, in the loss of the mechanical properties of the material.
Spots and stripes in nonlinear Schrödinger‐type equations with nearly one‐dimensional potentials
Authors: Haragus Mariana , Kapitula Todd
Published: May 2013

We consider the existence of spots and stripes for a class of nonlinear Schrödinger‐type equations in the presence of nearly one‐dimensional localized potentials. Under suitable assumptions on the potential, we construct various types of waves that are localized in the direction of the potential and have single‐ or multihump, or periodic profile in the perpendicular direction. The analysis relies upon a spatial dynamics formulation of the existence problem, together with a center manifold reduction. This reduction procedure allows these waves to be realized as unipulse or multipulse homoclinic orbits, or periodic orbits in a reduced system of ordinary differential equations. Copyright © 2013 John Wiley & Sons, Ltd.
A singularly perturbed nonlinear traction problem in a periodically perforated domain: a functional analytic approach
Authors: Dalla Riva M. , Musolino P.
Published: May 2013

We consider a periodically perforated domain obtained by making in a periodic set of holes, each of them of size proportional to ε. Then, we introduce a nonlinear boundary value problem for the Lamé equations in such a periodically perforated domain. The unknown of the problem is a vector‐valued function u, which represents the displacement attained in the equilibrium configuration by the points of a periodic linearly elastic matrix with a hole of size ε contained in each periodic cell. We assume that the traction exerted by the matrix on the boundary of each hole depends (nonlinearly) on the displacement attained by the points of the boundary of the hole. Then, our aim is to describe what happens to the displacement vector function u when ε tends to 0. Under suitable assumptions, we prove the existence of a family of solutions {u(ε, ⋅ )}ε ∈ ]0,ε ′ [ with a prescribed limiting behavior when ε approaches 0. Moreover, the family {u(ε, ⋅ )}ε ∈ ]0,ε ′ [ is in a sense locally unique and can be continued real analytically for negative values of ε. Copyright © 2013 John Wiley & Sons, Ltd.
Structural elucidation and NMR assignments of a new pyrrolizidine alkaloid from Crotalaria vitellina Ker Gawl
Authors: Casimiro Bezerra Denise Aline , Fechine Tavares Josean , dos Santos Paula Ferreira , Castello Branco Marianna Vieira Sobral , de Fátima Agra Maria , Subrinho Fernanda Lima , Braz‐Filho Raimundo , da Silva Marcelo Sobral
Published: May 2013

A new pyrrolizidine alkaloid, named crotavitelin, was isolated from fruits of Crotalaria vitellina, Fabaceae (Papilionoideae). The structure was established by spectroscopic techniques such as one‐dimensional and two‐dimensional NMR, IR, and MS. Copyright © 2013 John Wiley & Sons, Ltd.
B0‐informed variable density trajectory design for enhanced correction of off‐resonance effects in parallel transmission
Authors: Schneider Rainer , Ritter Dieter , Haueisen Jens , Pfeuffer Josef
Published: May 2013

Purpose

To improve B1 and B0 inhomogeneity mitigation performance of spatially selective radio‐frequency (RF) pulses in parallel transmission while decreasing RF pulse power. Further enhancement of off‐resonance correction for rectilinear spoke‐trajectory‐based RF pulses with known residual geometric distortions after optimization.

Methods

The appropriate definition of the target magnetization pattern is discussed regarding the maximum physical excitation resolution. Furthermore, a novel variable‐density trajectory design is introduced, which subsamples accrued B0 phase error elevations in k‐space. A simulation study (echo‐planar and spiral 2DRF) at different off‐resonance levels and pulse acceleration factors was pursued using data from a whole‐body 2‐channel parallel transmit 3T MRI system. The new trajectory design for echo‐planar 2DRF was validated in human in‐vivo experiments.

Results

Proper target pattern definition can require spatial filtering, such that RF pulse optimization is prevented from lower excitation performance with significant higher RF power level. The new trajectory design proposed can considerably improve off‐resonance compensation, while further reducing the RF power, e.g., 43% less RMSE with 79% less RF power for spoke based pulses.

Conclusion

The proposed methods offer significant improvements of the excitation performance (homogeneity and acceleration), while significantly decreasing the RF power. Furthermore, single‐channel transmit RF pulse performance can be similarly improved. Magn Reson Med 71:1381–1393, 2014. © 2013 Wiley Periodicals, Inc.
Resolving futile glucose cycling and glycogenolytic contributions to plasma glucose levels following a glucose load
Authors: Nunes Patricia M. , Jarak Ivana , Heerschap Arend , Jones John G.
Published: May 2013

Purpose

After a glucose load, futile glucose/glucose‐6‐phosphate (G6P) cycling (FGC) generates [2‐2H]glucose from 2H2O thereby mimicking a paradoxical glycogenolytic contribution to plasma glucose levels. Contributions of load and G6P derived from gluconeogenesis, FGC, and glycogenolysis to plasma glucose levels need resolution. A simple methodology is proposed integrating the administration of 2H2O with a glucose load containing [1‐2H, 1‐13C]glucose and [2‐2H, 2‐13C]glucose.

Methods

Mice fasted for 6 (n = 7) or 24 h (n = 5) were intraperitoneally injected with 2 mg/g 10% enriched glucose in 35 µL/g 2H2O. Plasma glucose enrichment was analyzed by 2H NMR after 30 min.

Results

For 6‐h fasted mice, 12.3 ± 1.5% of plasma glucose was pre‐existing, 44.3 ± 2.7% was load derived, and 43.4 ± 1.8% G6P derived. G6P origins were 26.0 ± 2.0% gluconeogenesis, 10.9 ± 2.6% FGC, and 6.5 ± 3.4% glycogenolysis. For 24‐h fasted mice, 18.2 ± 8.5% was pre‐existing, 41.1 ± 5.0 % was load derived, and 40.8 ± 4.3% G6P derived. G6P origins were 27.1 ± 3.3% gluconeogenesis, 13.1 ± 2.8% FGC, and 0.6 ± 2.4% glycogenolysis.

Conclusion

After a glucose load, glycogenolytic contribution to plasma glucose was negligible, whereas FGC was significant for both 6‐ and 24‐h fasted mice. Magn Reson Med 71:1368–1373, 2014. © 2013 Wiley Periodicals, Inc.
Magnetic resonance imaging of the retina: From mice to men
Authors: Duong Timothy Q.
Published: May 2013

This mini‐review provides an overview of magnetic resonance imaging (MRI) applications to study rodent, cat, non‐human primate, and human retinas. These techniques include T1‐ and T2‐weighted anatomical, diffusion, blood flow, blood volume, blood‐oxygenation level dependent, manganese‐enhanced, physiological, and functional MRI. Applications to study the retinas in diabetic retinopathy, glaucoma, and retinal degeneration are also reviewed. MRI offers some unique advantages compared with existing imaging techniques and has the potential to further our understanding of physiology and function in healthy and diseased retinas. Magn Reson Med 71:1526–1530, 2014. © 2013 Wiley Periodicals, Inc.
Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 AND DM2)
Authors: Gawel Malgorzata , Szmidt‐Salkowska Elzbieta , Lusakowska Anna , Nojszewska Monika , Sulek Anna , Krysa Wioletta , Rajkiewicz Marta , Seroka Andrzej , Kaminska Anna M.
Published: May 2013

Introduction: Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2. Methods: SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years). Results: We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC. Conclusions: SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing. Muscle Nerve 49: 277–283, 2014
A pilot study of muscle plasma protein changes after exercise
Authors: Dahlqvist Julia R. , Voss Line G. , Lauridsen Thomas , Krag Thomas O. , Vissing John
Published: May 2013

Introduction: Creatine kinase (CK) and myoglobin (Mb) do not possess all good qualities as biomarkers of skeletal muscle damage. We investigated the utility of troponin I (TnI) and telethonin (Tcap) as markers and examined their temporal profiles after skeletal muscle damage. Methods: Plasma profiles were measured before and after exercise in 3 groups: subjects affected by either Becker muscular dystrophy or McArdle disease, and healthy subjects. Results: Mb and TnI appeared early in the blood, and the increase of TnI was only observed in patients with muscle disease. The CK increase was more delayed in plasma. Tcap was not detectable at any time. Conclusions: Our results suggest that TnI is a marker of more severe damage signifying sarcomeric damage, and it could therefore be an important supplement to CK and Mb in clinical practice. Tcap is not useful as a marker for skeletal muscle damage. Muscle Nerve 49: 261–266, 2014
Small fibers, large impact: Quality of life in small‐fiber neuropathy
Authors: Bakkers Mayienne , Faber Catharina G. , Hoeijmakers Janneke G.J. , Lauria Giuseppe , Merkies Ingemar S.J.
Published: May 2013

Introduction: The impact of small‐fiber neuropathy (SFN) on patients' quality of life (QOL) has not been studied extensively. Our aim was to determine the impact of SFN on QOL and examine possible determinants. Methods: We examined a total of 265 patients diagnosed with SFN. The SFN Symptoms Inventory Questionnaire (SFN‐SIQ), the pain Visual Analog Scale (VAS), and the generic SF‐36 Health Survey were assessed. Regression studies were undertaken to evaluate determinants of functioning. Results: SFN patients demonstrated a severe overall reduction in QOL. The biggest deficits were in Role Functioning–Physical, Body Pain, and Physical Component Summary (PCS) scores. VAS scores, changed sweating pattern, dry mouth, and age were the strongest predictors for PCS, explaining 32% of the QOL decrease. Conclusions: SFN leads to a reduction in overall QOL. The presence of pain and some autonomic symptoms explained only a small portion of the findings. Muscle Nerve 49:329–336, 2014
Hybrid impotent–incompatible eigenstrain based homogenization
Authors: Fish Jacob , Filonova Vasilina , Yuan Zheng
Published: May 2013

We present a constitutive framework for a periodic heterogeneous medium with minimal number of internal variables. The method is based on a variant of the transformation field analysis (TFA) where eigenstrains are discretized using C 0 continuous approximation in matrix dominated mode of deformation, hereafter referred to as impotent eigenstrain mode, whereas in multiphase mode of deformation, the eigenstrains are approximated using the usual C  − 1 approximation. The delay in the onset of inelastic response and the eigenstrain induced anisotropy in a microphase, both characteristic to averaging methods, are alleviated by introducing an eigenstrain upwinding scheme and by enhancing constitutive laws of microphases. The proposed formulation has been verified against a direct numerical simulation. The method has been found to be very accurate in predicting an overall material response at a computational cost comparable with the phenomenological modeling of a periodic heterogeneous medium. Copyright © 2013 John Wiley & Sons, Ltd.
A wave finite element‐based formulation for computing the forced response of structures involving rectangular flat shells
Authors: Mencik Jean‐Mathieu
Published: May 2013

The harmonic forced response of structures involving several noncoplanar rectangular flat shells is investigated by using the Wave Finite Element method. Such flat shells are connected along parallel edges where external excitation sources as well as mechanical impedances are likely to occur. Also, they can be connected to one or several coupling elements whose shapes and dynamics can be complex. The dynamic behavior of the connected shells is described by means of numerical wave modes traveling towards and away from the coupling interfaces. Also, the coupling elements are modeled by using the conventional finite element (FE) method. A FE mesh tying procedure between shells having incompatible meshes is considered, which uses Lagrange multipliers for expressing the coupling conditions in wave‐based form. A global wave‐based matrix formulation is proposed for computing the amplitudes of the wave modes traveling along the shells. The resulting displacement solutions are obtained by using a wave mode expansion procedure. The accuracy of the wave‐based matrix formulation is highlighted in comparison with the conventional FE method through three test cases of variable complexities. The relevance of the method for saving large CPU times is emphasized. Its efficiency is also highlighted in comparison with the component mode synthesis technique. Copyright © 2013 John Wiley & Sons, Ltd.
Regularization of the noisy Cauchy problem solution approximated by an energy‐like method
Authors: Rischette R. , Baranger T. N. , Andrieux S.
Published: May 2013

This paper focuses on the regularization of noisy Cauchy data and unknown boundary conditions approximated by the energy‐like minimization method. After providing considerations necessary for the numerical analysis leading to an adequate stopping criterion for the minimization process, we describe the denoising procedure proposed. Numerical experiments involving singular data are presented.Copyright © 2013 John Wiley & Sons, Ltd.
Numerical manifold space of Hermitian form and application to Kirchhoff's thin plate problems
Authors: Zheng Hong , Liu Zhijun , Ge Xiurun
Published: May 2013

For second‐order problems, where the behavior is described by second‐order partial differential equations, the numerical manifold method (NMM) has gained great success. Because of difficulties in the construction of the H 2‐regular Lagrangian partition of unity subordinate to the finite element cover; however, few applications of the NMM have been found to fourth‐order problems such as Kirchhoff's thin plate problems. Parallel to the finite element methods, this study constructs the numerical manifold space of the Hermitian form to solve fourth‐order problems. From the minimum potential principle, meanwhile, the mixed primal formulation and the penalized formulation fitted to the NMM for Kirchhoff's thin plate problems are derived. The typical examples indicate that by the proposed procedures, even those earliest developed elements in the finite element history, such as Zienkiewicz's plate element, regain their vigor. Copyright © 2013 John Wiley & Sons, Ltd.
High‐resolution migration history of the Subtropical High/Trade Wind system of the northeastern Pacific during the last ~55 years: Implications for glacial atmospheric reorganization
Authors: Cheshire Heather , Thurow Juergen
Published: May 2013

Guaymas Basin, Gulf of California, is a restricted basin located under the present‐day wet/dry subtropical divide (~27°N) and is ideally circumstanced for detecting variations in the North Pacific Subtropical High (NPSH)/Trade Wind system. Controlled by climate cell boundary displacement, NPSH midwinter location was the primary influence on timing and intensity of upwelling seasons in Guaymas Basin. Analysis of high‐resolution X‐ray fluoresence data and sediment fabric log from 75% laminated Core MD02‐2517/2515, western Guaymas Basin, reveals systematic changes in NPSH behavior over the last ~55 kyr BP. Southward displacement of the wet/dry subtropical divide controlled upwelling‐related diatom productivity, while sea level and regional rainfall controlled terrigenous supply. The basin was oxic during the glacial, and preservation was ensured by high burial rate due to the increased deposition of terrigenous sediment. Sediment fabric style (number and/or thickness of laminae, plus color banding and homogeneous intervals) changes systematically through the core and gives insights into the number of seasons occurring in Guaymas Basin, and the occurrence and intensity of the upwelling season. Five millennial‐scale low flux events with close timing to Heinrich events and ten decadal/centennial‐scale low biogenic silica events occurring in the interval ~33–16.5000 years Before Present (kyr BP) are interpreted as times of extreme aridity. At ~16.5 kyr BP, a regime shift from terrigenous‐dominated oxic to evenly balanced biogenic‐terrigenous dysoxic conditions occurred. Although there was a further extreme arid event at ~11.5 kyr BP, ~16.5 kyr BP was essentially the beginning of the interglacial.
CONVERGENCE OF TWO INDEPENDENT ROADS LEADS TO COLLABORATION BETWEEN EDUCATION AND NEUROSCIENCE
Authors: Koch Kourtland R. , Timmerman L. , Peiffer Ann M. , Laurienti Paul J.
Published: May 2013

Collaboration is the foundation for innovative discoveries, as individuals with different backgrounds come together and combine their unique expertise. In the current article, an educational researcher and two neuroscientists relate their experiences in establishing a successful collaborative effort. The marriage of neuroscientific findings with educational research has begun to further advance educational approaches. Initial functional magnetic resonance imaging (fMRI) findings indicate that direct interplay between educational interventions and brain‐based measures of sensory, motor, and cognitive processes provides an important link among cognitive processing and psychometric measures. If neuroimaging results support existing theoretical constructs of brain organization, then testable hypotheses may be designed to determine which educational interventions will be effective. The neuropsychological approach may provide school psychologists and teachers with an extensive array of fMRI‐based, developmentally appropriate instructional strategies for enhancing the functional organization of the developing brain of children. Promising suggestions and strategies for educational researchers, school psychologists, and neuroscientists are included.