bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of Poly(chiral methylpropargyl ester)s Carrying Azobenzene Moieties
Authors: Jiang Feng , Qu Jinqing , Chen Huanqin
Published: October 2009

Novel chiral methylpropargyl esters bearing azobenzene groups, namely, 4‐[4′‐(benzyloxy)phenylazophenyl]‐ carbonyl‐(S)‐1‐methylpropargyl ester (e), 4‐[4′‐(n‐butyloxy)phenylazophenyl]carbonyl‐(S)‐1‐methylpropargyl ester (f), 4‐[4′‐(n‐hexyloxy)phenylazophenyl]carbonyl‐(S)‐1‐methylpropargyl ester (g), and 4‐[4′‐(n‐octyloxy)phenylazo‐ phenyl]carbonyl‐(S)‐1‐methylpropargyl ester (h) were synthesized and polymerized with Rh+(nbd)[η6‐C6H5B−‐ (C6H5)3] (nbd=norbornadiene) catalyst to give the corresponding polymers with moderate molecular weights (Mn=8.4×103–15.7×103) in good yields (76%? –?91%). The structures of polymers were illustrated by IR and NMR spectroscopies. Polymers were soluble in comment organic solvents including toluene, CHCl3 CH2Cl2, THF, and DMSO, while insoluble in diethyl ether, n‐hexane and methanol. Large optical rotations of polymer solutions demonstrated that all the polymers take a helical structure with a predominantly one‐handed screw sense in organic solvents.
A Simple Method for Controlling the Degree of PEGylation of Dynorphin A (1–13)
Authors: Wang Xiufang , Tian Yong , Zhong Guoying , Chen Guanke
Published: October 2009

Dynorphin A (1–13) was chemically modified by reaction with succinimidyl propionate‐monomethoxy polyethylene glycol (mPEG‐SPA). To determine the degree and the optimized condition for PEGylation of dynorphin A, the reactions were monitored in different pH buffers at different molar ratios by reversed‐phase high performance liquid chromatography (RP‐HPLC) and matrix‐assisted laser desorption/ionization time‐of‐?ight mass spectrometry (MALDI‐TOF MS). The results showed that the degree of PEGylation for dynorphin A could easily be controlled through adjustment of the molar ratios and the pH. The degree of PEGylation of dynorphin A increased as the molar ratio of dynorphin to MPEG‐SPA and the pH increased.
Progress in Scanning Electrochemical Microscopy by Coupling with Electrochemical Impedance and Quartz Crystal Microbalance
Authors: Keddam Michel , Portail Nicolas , Trinh Dao , Vivier Vincent
Published: October 2009

Scanning electrochemical microscopy (SECM) is a powerful technique for performing quantitative measurements at a local scale. This paper covers the development of combinations of SECM with electrochemical impedance spectroscopy (EIS) and electrochemical quartz crystal microbalance (EQCM). Basic aspects are described and potential applications reported by several research groups are covered. The unique advantages of the coupled techniques—with additional information being obtained from each coupling—are also discussed.
Bandgap characters in GaAs‐based ternary alloys
Authors: Tit N. , Amrane N. , Reshak A. H.
Published: October 2009

The existence and origins of the bowing character in the bandgap variation of GaAs‐based ternary alloys are theoretically investigated based on two different computational methods. Within the framework of the virtual crystal approximation (VCA), both the empirical sp3s * tight‐binding (TB) method with, and without, the inclusion of the spin‐orbit coupling effects, and the first‐principle full‐potential linear augmented plane wave (FP‐LAPW) technique are applied on both the common‐cation GaSbxAs1‐x and the common‐anion Ga1‐xInxAs alloys. These methods are used to calculate the bandgap energy, the partial and total densities of states and the constituent charge ionicity versus the composition x. The results show that the bowing behavior exists in the case of common‐cation alloys (GaSbxAs1‐x) as a manifestation of a competition between the anion atoms (As and Sb) in trapping the made‐available‐cationic charges. The bowing parameter is found to be proportional to the electronegativity characters of the competing anions (χanion). Consistent with this in the case of common‐anion alloys (Ga1‐xInxAs), as due to the lack of anion competition, the bowing is just absent and the variation of bandgap energy is found to be rather linear. The excellent agreement between our theoretical results and recent photoluminescence data has corroborated our claim. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous precipitation of calcium silicate hydrate in aqueous solutions
Authors: Ntafalias E. , Koutsoukos P. G.
Published: October 2009

Calcium silicate hydrates (C‐S‐H) are very important not only for their contribution to the development of cement and concrete properties but also for use as fillers and in silicate glasses. In the present work, the thermodynamics and the kinetics of the spontaneous precipitation of C‐S‐H from aqueous solutions were investigated over the pH range 10‐12 at 25 °C. The thermodynamic driving force was calculated taking into consideration all equilibria involved in the supersaturated solutions. In the range of the solution supersaturation values examined the precipitation occurred spontaneously, with the exception of the series of experiments done at pH 12.0, where induction times preceded the appearance of the precipitate. The rates were measured at constant pH as a function of the solution supersaturation and were found to depend strongly on the solution supersaturation, pH and on the total calcium to total silicate molar ratio in solution. Fit of the kinetics results in a power law relating rates of precipitation with respect to C‐S‐H precipitated, suggested a surface diffusion controlled mechanism for the formation of C‐S‐H. The precipitated solids did not show significant morphological differences at different pH values. From the induction times preceding the spontaneous precipitation at pH 12.0, a value of 30 mJm‐2 was calculated for the surface energy of C‐S‐H. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric field mediated switching of mechanical properties of strontium titanate at room temperature
Authors: Stöcker H. , Zschornak M. , Leisegang T. , Shakhverdova I. , Gemming S. , Meyer D. C.
Published: October 2009

In situ application of an electric field to a SrTiO3 single crystal plate during nanoindentation led to a reversible change of the mechanical properties at room temperature. When a field of 8 kV/cm was applied, Meyer hardness and Young's modulus decreased by 0.6 GPa and 11 GPa, respectively. An explanation for this behaviour is given by the diffusion of oxygen vacancies resulting in a distortion of the perovskite‐type of structure in the near‐surface layer tested by nanoindentation. Simulations using density functional theory support the dependence of elasticity on the presence of vacancies. Thus, we can show the remarkable influence of electric fields on oxide materials which should be considered and used in designing future applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cyclic Nrarp mRNA expression is regulated by the somitic oscillator but Nrarp protein levels do not oscillate
Authors: Wright David , Ferjentsik Zoltan , Chong Shang‐Wei , Qiu Xuehui , Jiang Yun‐Jin , Malapert Pascale , Pourquié Olivier , Van Hateren Nick , Wilson Stuart A. , Franco Claudio , Gerhardt Holger , Dale J. Kim , Maroto Miguel
Published: October 2009

Somites are formed progressively from the presomitic mesoderm (PSM) in a highly regulated process according to a strict periodicity driven by an oscillatory mechanism. The Notch and Wnt pathways are key components in the regulation of this somitic oscillator and data from Xenopus and zebrafish embryos indicate that the Notch‐downstream target Nrarp participates in the regulation of both activities. We have analyzed Nrarp/nrarp‐a expression in the PSM of chick, mouse and zebrafish embryos, and we show that it cycles in synchrony with other Notch regulated cyclic genes. In the mouse its transcription is both Wnt‐ and Notch‐dependent, whereas in the chick and fish embryo it is simply Notch‐dependent. Despite oscillating mRNA levels, Nrarp protein does not oscillate in the PSM. Finally, neither gain nor loss of Nrarp function interferes with the normal expression of Notch‐related cyclic genes. Developmental Dynamics 238:3043–3055, 2009. © 2009 Wiley‐Liss, Inc.
An estrogen receptor alpha activity indicator model in mice
Authors: Han Sang Jun , O'Malley Bert W. , DeMayo Francesco J.
Published: October 2009

Estrogen receptor alpha (ERα), plays essential roles in the female reproduction. To investigate the dynamic changes in ERα activity in vivo, we have developed an ER Alpha Activity Indicator (ERAAI) mouse. This ERAAI mouse harbors both a modified ERα Bacterial Artificial Chromosome (BAC) clone and a reporter gene which is regulated specifically by the modified receptor. The ERα modification (Gal4‐ERα) consists replacing the DNA binding domain (DBD) of ERα with the DBD of yeast Gal4 transcription factor. This reporter transgene consisting of a humanized renilla Green Fluorescent Protein (hrGFP) sequence controlled by the Upstream Activating Sequences for the Gal4 gene (UASG) was inserted into the modified ERα BAC clone. Expression of Gal4‐ERα and hrGFP reliably recapitulates endogenous ERα expression and activity in the estrogen target tissues in response to estrogen stimulation. Therefore, the ERAAI mouse represents a novel animal model to investigate dynamic ERα activity in vivo. genesis 47:815–824, 2009. © 2009 Wiley‐Liss, Inc.
Cover Picture: Eur. J. Immunol. 11/09
Authors: Jevnikar Zala , Obermajer Nataša , Pečar‐Fonović Urša , Karaoglanovic‐Carmona Adriana , Kos Janko
Published: October 2009

This issue's cover features a composite of images showing that cathepsin X promotes co‐localization of LFA‐1 and α‐actinin‐1 and are taken from Jevnikar et al. (pp. 3217–3227). In this article, the authors show that cleavage of the three C‐terminal amino acids of the β2 cytoplasmic tail of LFA‐1 by cathepsin X promotes binding of α‐actinin‐1 to LFA‐1; cathepsin X also enables LFA‐1 to transition from its high to intermediate affinity form for ICAM‐1. Together, the findings further our understanding of the mechanisms of T‐cell migration.
Dimeric Nickel(II) Containing Tungstogermanate [{β‐GeNi2W10O36(OH)2(H2O)}2]12–
Authors: Nsouli Nadeen H. , Prinz Manuel , Damnik Niklas , Neumann Manfred , Talik Ewa , Kortz Ulrich
Published: October 2009

Interaction of the dilacunary polyanion precursor[γ‐GeW10O36]8– with Ni2+ ions in aqueous medium (pH 5.5) resulted in the formation of the dimeric, tetranickel(II)‐containing 20‐tungsto‐2‐germanate [{β‐GeNi2W10O36(OH)2(H2O)}2]12– (1). Polyanion 1 is composed of two lacunary (β‐GeW10O37) units accommodating two Ni2+ ions each and linked through two triply bridging OH groups. Single‐crystal X‐ray analysis was carried out on K10Ni[{β‐GeNi2W10O36(OH)2(H2O)}2]·28H2O (KNi‐1), which crystallizes in the triclinic system. The title compound KNi‐1 was characterized by IR spectroscopy, elemental analysis, single‐crystal XRD, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. Magnetization measurements on KNi‐1 revealed that the title polyanion 1 exhibits an antiferromagnetically coupled Ni4 core. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Seismic collapse risk of precast industrial buildings with strong connections
Authors: Kramar Miha , Isaković Tatjana , Fischinger Matej
Published: October 2009

A systematic seismic risk study has been performed on some typical precast industrial buildings that consists of assemblages of cantilever columns with high shear‐span ratios connected to an essentially rigid roof system with strong pinned connections. These buildings were designed according to the requirements of Eurocode 8. The numerical models and procedures were modified in order to address the particular characteristics of the analyzed system. They were also verified by pseudo‐dynamic and cyclic tests of full‐scale large buildings. The intensity measure (IM)‐based solution strategy described in the PEER methodology was used to estimate the seismic collapse risk in terms of peak ground acceleration capacity and the probability of exceeding the global collapse limit state. The effect of the uncertainty in the model parameters on the dispersion of collapse capacity was investigated in depth. Reasonable seismic safety (as proposed by the Joint Committee on Structural Safety) was demonstrated for all the regular single‐storey precast industrial buildings addressed in this study. However, if the flexural strength required by EC8 was exactly matched, and the additional strength, which results from minimum longitudinal reinforcement, was disregarded as well as large dispersion in records was considered, the seismic risk might in some cases exceed the acceptable limits. Copyright © 2009 John Wiley & Sons, Ltd.
Display panel design of a general utility helicopter by applying quantitative and qualitative approaches
Authors: Şenol Mehmet Burak , Dağdeviren Metin , Çilingir Canan , Kurt Mustafa
Published: October 2009

The flight deck is the ultimate human–machine interface application. It uses human senses of touch and sight in a safety‐critical situation. Display systems, present on a flight deck, are complex environments causing excessive mental workload, and the consequences of errors can be catastrophic. To prevent any human error, a user‐friendly display panel must be designed. In this research the best natural dialog between the crew and interface is considered while reflecting user perspective to design by applying quantitative and qualitative approaches; in this way, proper positions of analogue indicators on the front of the display panel are determined. Multi‐Criteria Decision Making algorithms are employed as a quantitative approach. To test whether the decision‐making preferences are consistent with a quasi‐concave, a quasi‐convex, and a linear utility function, a combined algorithm is applied. Due to the form of utility function, an algorithm finding the most preferred alternative of decision making is used. The aim of this approach is to find an order in which to locate each indicator to suitable classes. Card‐Sorting methodology is used for the qualitative research of the same problem. Results of two different approaches are compared. © 2009 Wiley Periodicals, Inc.
The oral cancer epidemic in central and eastern Europe
Authors: Garavello Werner , Bertuccio Paola , Levi Fabio , Lucchini Franca , Bosetti Cristina , Malvezzi Matteo , Negri Eva , La Vecchia Carlo
Published: October 2009

To monitor recent trends in oral and pharyngeal cancer mortality in 38 European countries, we analyzed data provided by the World Health Organization over the period 1975–2004. Joinpoint analysis was used to identify significant changes in trends. In the European Union (EU), male mortality rates rose by 2.1% per year between 1975 and 1984, by 1.0% between 1984 and 1993, and declined by 1.3% between 1993 and 2004, to reach an overall age‐standardized rate of 6.1/100,000 in 2000–2004. Mortality rates were much lower in women, and the rate in the EU rose by 0.9% per year up to 2000, and levelled off to 1.1/100,000 in 2000–2004. In France and Italy—which had the highest rates in the past—male rates have steadily declined during the last two decades (annual percent change, APC = −4.8% in 1998–2004 in France and −2.6% in 1986–2003 in Italy). Persisting rises were, however, observed in several central and eastern European countries, with exceedingly high rates in Hungary (21.1/100,000; APC = 6.9% in 1975–1993 and 1.4% in 1993–2004) and Slovakia (16.9/100,000; APC = 0.14% in 1992–2004). In middle aged (35 to 64) men, oral and pharyngeal cancer mortality rates in Hungary (55.3/100,000) and Slovakia (40.8/100,000) were comparable to lung cancer rates in several major European countries. The highest rates for women were in Hungary (3.3/100,000; APC = 4.7% in 1975–2004) and Denmark (1.6/100,000; APC = 1.3% in 1975–2001). Oral and pharyngeal cancer mortality essentially reflects the different patterns in tobacco smoking and alcohol drinking, including drinking patterns and type of alcohol in central Europe.
Premature mortality due to cancer in Japan, 1995 and 2005
Authors: Pham Truong‐Minh , Fujino Yoshihisa , Matsuda Shinya , Yoshimura Takesumi
Published: October 2009

To better understand premature mortality due to cancer, we estimated years of life lost (YLL) and average years of life lost (AYLL) due to cancer for the years 1995 and 2005, based on data from the Vital Statistic of Japan. In men, we identified a total of 159,623 cancer deaths in 1995 and 196,603 in 2005. Total YLL were 2,342,560.4 and 2,724,066.0 years, respectively. Averaged for all cancers, people died 14.7 years earlier than life expectancy in 1995 and 13.9 years in 2005. AYLL was longest for brain cancer deaths, at 26.3 years earlier than expected in 1995 and 22.8 years in 2005, followed by leukemia. In women, a total of 103,399 cancer deaths occurred in 1995 and 129,338 in 2005. Total YLL were 1,818,960.4 years in 1995 and 2,160,706.5 years in 2005, corresponding to AYLL for all cancer combined of 17.6 and 16.7 years. The AYLL of brain cancer deaths was also the longest, at 29.4 years in 1995 and 27.8 in 2005, followed by leukemia and female sex‐related cancers. Results showed that cancer of the stomach, colorectum, liver and lung were the most frequent cancers in both sexes in both 1995 and 2005 and responsible for a remarkable number of YLL. Further, AYLL was greatest for brain cancer and leukemia in both sexes and for sex‐related cancers in women, namely breast, cervix and ovarian cancer.
Conformational populations of ligand‐sized molecules by replica exchange molecular dynamics and temperature reweighting
Authors: Okumura Hisashi , Gallicchio Emilio , Levy Ronald M.
Published: October 2009

The use of the replica exchange (RE) molecular dynamics (MD) method for the efficient estimation of conformational populations of ligand‐sized molecules in solution is investigated. We compare the computational efficiency of the traditional constant temperature MD technique with that of the parallel RE molecular dynamics method for a series of alkanes and rilpivirine (TMC278), an inhibitor against HIV‐1 reverse transcriptase, with implicit solvation. We show that conformational populations are accurately estimated by both methods; however, replica exchange estimates converge at a faster rate, especially for rilpivirine, which is characterized by multiple stable states separated by high‐free energy barriers. Furthermore, convergence is enhanced when the weighted histogram analysis method (WHAM) is used to estimate populations from the data collected from multiple RE temperature replicas. For small drug‐like molecules with energetic barriers separating the stable states, the use of RE with WHAM is an efficient computational approach for estimating the contribution of ligand conformational reorganization to binding affinities. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Density functional theory study of calix[4]arene‐N‐azacrown‐5, calix[4]arene‐N‐phenyl‐azacrown‐5, and their complexes with alkali‐metal cations: Na+, K+, and Rb+
Authors: Zheng Xiaoyan , Wang Xueye , Yi Shanfeng , Wang Nuanqing , Peng Yueming
Published: October 2009

Theoretical studies of 1,3‐alternate‐25,27‐bis(1‐methoxyethyl)calix[4]arene‐azacrown‐5 (L1), 1,3‐alternate‐25,27‐bis(1‐methoxyethyl)calix[4]arene‐N‐phenyl‐azacrown‐5 (L2), and the corresponding complexes M+/ L of L1 and L2 with the alkali‐metal cations: Na+, K+, and Rb+ have been performed using density functional theory (DFT) at B3LYP/6‐31G* level. The optimized geometric structures obtained from DFT calculations are used to perform natural bond orbital (NBO) analysis. The two main types of driving force metal–ligand and cation–π interactions are investigated. The results indicate that intermolecular electrostatic interactions are dominant and the electron‐donating oxygen offer lone pair electrons to the contacting RY* (1‐center Rydberg) or LP* (1‐center valence antibond lone pair) orbitals of M+ (Na+, K+, and Rb+). What's more, the cation–π interactions between the metal ion and π‐orbitals of the two rotated benzene rings play a minor role. For all the structures, the most pronounced changes in geometric parameters upon interaction are observed in the calix[4]arene molecule. In addition, an extra pendant phenyl group attached to nitrogen can promote metal complexation by 3D encapsulation greatly. In addition, the enthalpies of complexation reaction and hydrated cation exchange reaction had been studied by the calculated thermodynamic data. The calculated results of hydrated cation exchange reaction are in a good agreement with the experimental data for the complexes. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Generation and characterization of low‐energy structures in atomic clusters
Authors: Marques J. M. C. , Pais A. A. C. C. , Abreu P. E.
Published: October 2009

Factors relevant for controlling the structures determined in the local optimization of argon clusters are investigated. In particular, the role of volume and shape for the box where initial structures are generated is assessed. A thorough characterization of the optimization is also presented, based on a nearest‐neighbor analysis, in clusters ranging from 30 to 55 atoms. This includes the assessment of the degree of preservation of aspects of the initial randomly generated structure in the final optimized counterpart, and the correlation between optimized energy and the number of nearest neighbors and average departure from the diatomic reference distance. The usefulness of this analysis to explore the energy landscape of atomic clusters is also highlighted. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Including receptor flexibility and induced fit effects into the design of MMP‐2 inhibitors
Authors: Durrant Jacob D. , de Oliveira César Augusto F. , McCammon J. Andrew
Published: October 2009

Matrix metalloproteinases (MMPs) comprise a class of flexible proteins required for normal tissue remodeling. Overexpression of MMPs is associated with a wide range of pathophysiological processes, including vascular disease, multiple sclerosis, Alzheimer's disease, and cancer. Nearly all MMP inhibitors have failed in clinical trials, in part due to lack of specificity. Due to the highly dynamic molecular motions of the MMP‐2 binding pockets, the rational drug design of MMP inhibitors has been very challenging. To address these challenges, in the current study we combine computer docking with molecular dynamics (MD) simulations in order to incorporate receptor‐flexibility and induced‐fit effects into the drug‐design process. Our strategy identifies molecular fragments predicted to target multiple MMP‐2 binding pockets. Copyright © 2009 John Wiley & Sons, Ltd.
Generation of gas‐phase sodiated arenes such as [(Na3(C6H4)+] from benzene dicarboxylate salts
Authors: Attygalle Athula B. , Chan Chang‐Ching , Axe Frank U. , Bolgar Mark
Published: October 2009

Upon collision‐induced activation, gaseous sodium adducts generated by electrospray ionization of disodium salts of 1,2‐ 1,3‐, and 1,4‐benzene dicarboxylic acids (m/z 233) undergo an unprecedented expulsion of CO2 by a rearrangement process to produce an ion of m/z 189 in which all three sodium atoms are retained. When isolated in a collision cell of a tandem‐in‐space mass spectrometer, and subjected to collision‐induced dissociation (CID), only the m/z 189 ions derived from the meta and para isomers underwent a further CO2 loss to produce a peak at m/z 145 for a sodiated arene of formula (Na3C6H4)+. This previously unreported m/z 145 ion, which is useful to differentiate meta and para benzene dicarboxylates from their ortho isomer, is in fact the sodium adduct of phenelenedisodium. Moreover, the m/z 189 ion from all three isomers readily expelled a sodium radical to produce a peak at m/z 166 for a radical cation [(•C6H4CO2Na2)+], which then eliminated CO2 to produce a peak at m/z 122 for the distonic cation (•C6H4Na2)+. Copyright © 2009 John Wiley & Sons, Ltd.
Enhanced extraction yields and mobile phase separations by solvent mixtures for the analysis of metabolites in Annona muricata L. leaves
Authors: Ribeiro de Souza Eloana Benassi , da Silva Renata Reis , Afonso Sabrina , Scarminio Ieda Spacino
Published: October 2009

The effects of five extraction solvents and their mixtures on the yield of metabolites in crude and fractionated extracts of Annona muricata L. leaves were investigated by direct comparison. Extraction media were prepared using simplex centroid mixtures of ethanol, ethyl acetate, dichloromethane, acetone, and chloroform. The effects of the mobile phase solvent strength and the analysis wavelength on the chromatographic separation were also investigated. Solvent mixtures rather than pure solvents were found to be the most efficient extractors for the different fractions. The results indicated that the mobile phase composed of methanol/acetonitrile/water (26:27:47 v/v/v) was most suitable for the basic fraction analysis at 254 nm, whereas the mobile phase composed of methanol/acetonitrile/water (35:35:30 v/v/v) was the most adequate for the organic fraction analysis at 254 nm. The results indicated that the chromatographic profiles and number of peaks were affected by the mobile phase strength and analysis wavelength.
An automatic peak finding method for LC‐MS data using Gaussian second derivative filtering
Authors: Fredriksson Mattias J. , Petersson Patrik , Axelsson Bengt‐Olof , Bylund Dan
Published: October 2009

A highly automated procedure for localising and characterising peaks in the chromatographic time domain of LC‐MS data has been developed. The work was initiated by an identified need to facilitate the detection and tracking of chromatographic peaks during method development for the analysis of impurities in pharmaceutical products. The algorithm is mainly based on a digital filter for which the settings are automatically adapted to the data set under study. The procedure was evaluated for synthetic data sets with various S/N levels, peak widths and baseline properties. It was found that even for the worst case tested with S/N=10 and a high variability in the baseline, 94% of the simulated analytical peaks could be detected without producing any false‐positive identifications. Furthermore, the number of correctly estimated peak heights and peak widths falling within a 10% error of the true values were 94 and 91%, respectively. For experimental data sets, peak height, and width estimations were more difficult, but the processed reconstructions showed an excellent agreement with the analytical signals of the raw data, and also a clearly improved visualisation in total ion‐ and base‐peak chromatograms.
Quantitative structure–retention relationships for mycotoxins and fungal metabolites in LC‐MS/MS
Authors: Ji Caihong , Li Yanwei , Su Li , Zhang Xiaoyun , Chen Xingguo
Published: October 2009

Quantitative structure–retention relationship (QSRR) models were used to predict the retention time (tR) of mycotoxins and fungal metabolites. Heuristic method and radial basis function neural networks (RBFNN) were utilized to construct the linear and non‐linear QSRR models, respectively. The optimal QSRR model was developed based on a 5‐21‐1 RBFNN architecture using molecular descriptors calculated from molecular structure alone. The RBFNN model gave a square of correlation coefficient (R2) of 0.8709 and root mean square error of 1.2892 for the test set. This article provided a useful tool for predicting the tR of other mycotoxins when experiment data are unknown.
Phenyl‐type and C1 stationary phases for environmentally friendlier chromatography
Authors: Stevenson Paul G. , Soliven Arianne , Dennis Gary R. , Shalliker Ross A.
Published: October 2009

C1 and phenyl‐type stationary phases were assessed in terms of their environmental impact on separations using as test solutes polycyclic aromatic hydrocarbons. Methanol (MeOH) and acetonitrile (ACN) mobile‐phase gradients were employed. These stationary phases were examined to determine if different physical and chemical properties possessed by these surfaces decreased the organic solvent consumption, and yet maintained peak capacity. The cumulative energy demand (CED) was used to gauge the environmental impact of the separations. The separation of the polycyclic aromatic hydrocarbon test mixture using current methodologies (i.e. a C18/ACN combination) had a CED of 1.13 MJ‐eq, and a peak capacity of 27 peaks (resolving 7 of 12 peak pairs with Rs>1). In comparison, a butyl phenyl stationary phase with a methanol mobile phase had a peak capacity of 26, but with a CED of 0.670 MJ‐eq. Monolithic columns containing C18 and C1 phases were also tested. A monolithic C18 column with MeOH had the lowest CED at 0.675 MJ‐eq, a peak capacity of 28 peaks and good resolving power (resolving ten peak pairs with Rs>1), suggesting that this is a viable option with respect to reducing environmental impact for these types of analyses.
Solid‐phase extraction of liquiritin and glycyrrhizic acid from licorice using ionic liquid‐based silica sorbent
Authors: Tian Minglei , Bi Wentao , Row Kyung Ho
Published: October 2009

A new ionic liquid‐based silica sorbent was developed by a process involving surface chemical modification of commercial silica using a synthesized ionic liquid. The obtained particles were successfully used as a special sorbent in a solid‐phase extraction process to isolate liquiritin and glycyrrhizic acid from licorice. Different washing and elution solvents, such as water, methanol/water (v/v), and pure methanol were evaluated. Ionic liquid‐based silica sorbent was compared with traditional C18 sorbent and it exhibited higher selectivity. Quantitative analysis was carried out by using a C18 column. Good linearities of two compounds were obtained from 5×10−4 to 0.2 mg/mL (r2>0.99) with the relative standard deviations <1.0%. The target compounds in commercial herbal medicines containing licorice were determined, and the bound rates between the target compounds and protein were obtained by this sorbent.
Evaluation of sulfobetaine‐type polymer resin as an SPE adsorbent in the analysis of trace tetracycline antibiotics in honey
Authors: Tsukamoto Tomoyasu , Yasuma Mari , Yamamoto Atsushi , Hirayama Kayo , Kihou Takafumi , Kodama Shuji , Inoue Yoshinori
Published: October 2009

A new sulfobetaine polymer resin SPE method combined with HPLC‐MS/MS for the determination of tetracycline (TC) antibiotics residues from honey samples is presented. The sulfobetaine resin was synthesized and was packed into a syringe‐type tube, which served as the SPE cartridge for selective adsorption of TCs. TCs were quantitatively adsorbed on the sulfobetaine cartridge, when the loading solvent was 95% v/v acetonitrile solution, and TCs adsorbed were not eluted by aqueous acetonitrile washing solution. TFA aqueous solution was used for eluting the adsorbed TCs. The proposed SPE method has been applied to the determination of TCs in honey samples. The recoveries of TCs spiked in honey samples ranged from 70 to 80%. Reduction of the recoveries might be derived from low solubility of TCs in acetonitrile. Compared with other SPE resins, this resin was superior in terms of selectivity with simple pretreatment.
Nash problem for stable toric varieties
Authors: Petrov Peter
Published: October 2009

The main result of this paper is the proof of the Nash conjecture for stable toric varieties. We also introduce the Nash problem for pairs and prove it in the case of pairs (X, Y) of a toric variety X and a proper closed T ‐invariant subset Y containing Sing(X) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carathéodory–Julia type conditions and symmetries of boundary asymptotics for analytic functions on the unit disk
Authors: Bolotnikov Vladimir , Kheifets Alexander
Published: October 2009

It is shown that the following conditions are equivalent for the generalized Schur class functions at a boundary point t0 ∈ 𝕋: 1) Carathéodory–Julia type condition of order n; 2) agreeing of asymptotics of the original function from inside and of its continuation by reflection from outside of the unit disk 𝔻 up to order 2n + 1; 3) t0‐isometry of the coefficients ofthe boundary asymptotics; 4) a certain structured matrix ℙ constructed from these coefficients being Hermitian. It is also shown that for an arbitrary analytic function, properties 2), 3), 4) are still equivalent to each other and imply 1) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Osculating properties of decomposable scrolls
Authors: Lanteri Antonio , Mallavibarrena Raquel
Published: October 2009

Osculating spaces of decomposable scrolls (of any genus and not necessarily normal) are studied and their inflectional loci are related to those of their generating curves by using systematically an idea introduced by Piene and Sacchiero in the setting of rational normal scrolls. In this broader setting the extra components of the second discriminant locus – deriving from flexes – are investigated and a new class of uninflected surface scrolls is presented and characterized. Further properties related to osculation are discussed for (not necessarily decomposable) scrolls (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A variational characterization of rate‐independent evolution
Authors: Stefanelli Ulisse
Published: October 2009

Rate‐independent evolution driven by non‐convex potentials is by nature non‐smooth and some weak solvability notions have been recently advanced. This note is intended to contribute to this discussion by proposing a variational characterization of rate‐independent evolution based on a variational principle and a maximal dissipation criterion. The resulting novel solution notion is assessed in an elementary yet critical scalar case (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
HIV lumbosacral radiculoplexus neuropathy mimicking lymphoma: Diffuse infiltrative lymphocytosis syndrome (DILS) restricted to nerve?
Authors: Chahin Nizar , Temesgen Zelalem , Kurtin Paul J. , Spinner Robert J. , Dyck P. James B.
Published: October 2009

Diffuse infiltrative lymphocytosis syndrome (DILS) is a hyperimmune reaction against HIV. It leads to MHC‐restricted clonal expansion of CD8 T cells characterized by circulating CD8 hyperlymphocytosis and CD8 T‐cell infiltration in organs. Our patient presented with painful lumbosacral radiculoplexus neuropathy and tested positive for HIV. Nerve biopsy showed large collections of CD8 lymphocytes suspicious for lymphoma. Symptoms, signs, and repeat biopsy improved with antiretroviral treatment. The presentation and treatment response suggest that this case is localized DILS. Muscle Nerve, 2010
Martin–Gruber anastomosis with anomalous superficial radial innervation to ulnar dorsum of hand: A pitfall when common variants coexist
Authors: Leis A. Arturo , Stetkarova Ivana , Wells Keionna J.
Published: October 2009

The Martin–Gruber anastomosis (MGA) is the most common anatomic variation in the upper extremity. Anomalous superficial radial innervation to the ulnar dorsum of the hand is the most common cause of an absent dorsal ulnar cutaneous (DUC) response. The coexistence of these variants introduces a relatively common yet underrecognized potential pitfall in nerve conduction studies (NCS). We performed confirmatory NCS in two cases referred for ulnar neuropathy in the forearm (case 1) and at the elbow (UNE, case 2). Initial NCS in both cases suggested ulnar nerve injury at the forearm and elbow, respectively, based on an apparent conduction block in ulnar motor fibers in the forearm (case 1) and elbow (case 2), and absent DUC responses. Additional NCS documented an MGA in the mid‐forearm (case 1) and high proximal forearm (case 2) with anomalous superficial radial innervation to the ulnar dorsum of the hand (both cases). Failure to recognize the coexistence of these two common variants may lead to misdiagnosis of ulnar neuropathy and inappropriate treatment. Muscle Nerve, 2009
Driving with polyneuropathy
Authors: Cho S. Charles , Katzberg Hans D. , Rama Anil , Kim Byung‐Jo , Roh Hakjae , Park Jongsoo , Katz Jonathan , So Yuen T.
Published: October 2009

Polyneuropathy may result in pain, numbness, and weakness, which may in turn affect driving ability. Medications used to treat neuropathic pain may alter cognition, which may further affect driving. Although such impairments have engendered questions about the driving safety in this group of patients, the rate of motor vehicle accidents (MVAs) in patients with neuropathy has not been studied rigorously. We surveyed patients with neuropathy from three medical centers for reported accident rate, and we analyzed variables related to increased risk for accidents compared to National Highway Traffic Safety Administration data. Surveys from 260 subjects demonstrated that 40.6% were involved in traffic accidents (0.11 accidents/year). Their accident rate was 10.8 MVAs per million vehicle miles traveled (MVA/MVMT), compared to 3.71 MVA/MVMT in 55–59‐year‐old drivers and 3.72 in 60–64‐year‐olds (National Highway Traffic Safety Administration data). In all, 72.4% cited their neuropathy and 55.2% cited their medications as playing a role in their accidents, and 51.6% changed their driving habits after developing neuropathy. Independently, elevated levels of pain, motor weakness, and ambulation difficulty met statistical significance for increased MVA frequency. We conclude that accident frequency and discomfort with driving are higher in neuropathy patients compared to age‐matched national statistics. However, most patients seem to change habits according to their ability to drive; as such, driving issues should be addressed with caution and on a case‐by‐case basis. Muscle Nerve, 2009
Homozygosity for dominant mutations increases severity of muscle channelopathies
Authors: Arzel‐hézode Marianne , Sternberg Damien , Tabti Nacira , Vicart Savine , Goizet Cyril , Eymard Bruno , Fontaine Bertrand , Fournier Emmanuel
Published: October 2009

Muscle channelopathies caused by mutations in the SCN4A gene that encodes the muscle sodium channel are transmitted by autosomal‐dominant inheritance. We report herein the first cases of homozygous patients for sodium channel mutations responsible for paramyotonia congenita (I1393T) or hypokalemic periodic paralysis (R1132Q). A parallel was drawn between this unprecedented situation and that of myotonia congenita by including patients homozygous or heterozygous for the CLCN1 I556N channel mutation, which is known for incomplete dominance and penetrance. Standardized electromyographic (EMG) protocols combining exercise and cold served as provocative tests to compare homozygotes with heterozygotes for each of the three mutations. Surface‐recorded compound muscle action potentials (CMAPs) were used to monitor muscle electrical activity, and myotonic discharges were evaluated by needle EMG. In heterozygous patients, exercise tests disclosed abnormal patterns of CMAP changes, which matched those previously described for similar dominant sodium and chloride channel mutations. Homozygotes showed much more severe clinical features and CMAP changes. We hypothesized that the presence of 100% defective ion channels in the homozygotes could account for the most severe phenotype. This suggests that the severity of muscle channelopathies depends both on the degree of channel impairment caused by the mutation and on the number of mutant channels engaged in the pathophysiological process. Overall, this study has practical consequences for the diagnosis of muscle channelopathies and raises new questions about their pathophysiology. Muscle Nerve, 2010
Unusual Charcot–Marie–Tooth phenotype due to a mutation within the intracellular domain of myelin protein zero
Authors: Schneider‐Gold Christiane , Kötting Judith , Epplen Jörg T. , Gold Ralf , Gerding Wanda M.
Published: October 2009

Myelin protein zero (MPZ/P0) constitutes a major component of compact peripheral myelin. We report a family with a missense mutation, c.700G>T p.Asp234Tyr (deviant nomenclature: c.670G>T, p.Asp224Tyr), within the intracellular domain of myelin protein zero, who has distal sensorimotor symptoms, cramps, restless legs syndrome, neuropathic pain, and carpal tunnel syndrome. The index patient responded to intravenous immunoglobulin and immunosuppression, so there may be a possible secondary autoimmune process, probably triggered by altered antigen presentation due to mutated MPZ protein. Muscle Nerve, 2010
Coexistent autoimmune autonomic ganglionopathy and myasthenia gravis associated with non–small‐cell lung cancer
Authors: Peltier Amanda C. , Black Bonnie K. , Raj Satish R. , Donofrio Peter , Robertson David , Biaggioni Italo
Published: October 2009

We report the case of a 55‐year‐old man with non–small‐cell lung cancer who underwent radiation, chemotherapy with carbotaxol and paclitaxel, and left upper lobe removal 2 years prior to evaluation. He was referred for disabling orthostatic hypotension (113/69 mm Hg supine and 66/47 mm Hg standing after 10 minutes) without a compensatory heart rate increase (57 to 59 beats per minute), fatigue, and constipation with episodes of ileus. Clinical examination showed mild ptosis bilaterally, fatiguable neck flexor weakness, and hip flexor weakness. Blood pressure response to Valsalva maneuver was abnormal with an absence of phase 4 overshoot and a Valsalva heart rate ratio of 1.04. Plasma norepinephrine level was low (79 pg/ml supine, 330 pg/ml standing). Single‐fiber electromyography of the right extensor digitorum communis revealed normal mean consecutive difference (jitter) but several pairs exceeded a jitter of 100 μs. Antibodies against muscle acetylcholine receptor [(AChR) 0.66 nmol/L, normal <0.02 nmol/L] and ganglionic AChR (0.34 nmol/L, normal <0.02 nmol/L) were present. Treatment with plasma exchange normalized responses to standing posture (105/68 supine to 118/82 mm Hg standing, 66 to 79 beats per minute), to Valsalva (normal blood pressure overshoot, hazard ratio 1.47), norepinephrine (194 pg/ml supine, 763 pg/ml standing), and jitter measurements. We conclude that autoimmune autonomic ganglionopathy and myasthenia gravis can coexist and suggest that the latter should be excluded in patients with autoimmune autonomic ganglionopathy who complain of fatigue that shows improvement with non‐supine rest. Muscle Nerve, 2009
Clinical findings in MuSK‐antibody positive myasthenia gravis: A U.S. experience
Authors: Pasnoor Mamatha , Wolfe Gil I. , Nations Sharon , Trivedi Jaya , Barohn Richard J. , Herbelin Laura , McVey April , Dimachkie Mazen , Kissel John , Walsh Ronan , Amato Anthony , Mozaffar Tahseen , Hungs Marcel , Chui Luis , Goldstein Jonathan , Novella Steven , Burns Ted , Phillips Lawrence , Claussen Gwendolyn , Young Angela , Bertorini Tulio , Oh Shin
Published: October 2009

We performed a retrospective chart review on 53 muscle‐specific kinase antibody (MuSK‐Ab)‐positive myasthenia gravis (MG) patients at nine university‐based centers in the U.S. Of these, 66% were Caucasian, 85% were women, and age of onset was 9–79 years. Twenty‐seven patients were nonresponsive to anticholinesterase therapy. Myasthenia Gravis Foundation of America improvement status was achieved in 53% patients on corticosteroids, 51% with plasma exchange, and in 20% on intravenous immunoglobulin (IVIG). Thymectomy was beneficial in 7/18 patients at 3 years. Long‐term (≥3 years) outcome was very favorable in 58% of patients who achieved remission and/or minimal manifestation status. Overall, 73% improved. There was one MG‐related death. This survey reinforces several cardinal features of MuSK‐Ab‐positive MG, including prominent bulbar involvement and anticholinesterase nonresponsiveness. Facial or tongue atrophy was rare. Most patients respond favorably to immunotherapy. The best clinical response was to corticosteroids and plasma exchange, and the poorest response was to IVIG. Long‐term outcome is favorable in about 60% of cases. Muscle Nerve, 2009
Multiscale modeling of impact on heterogeneous viscoelastic solids containing evolving microcracks
Authors: Souza Flavio V. , Allen David H.
Published: October 2009

Multiscale computational techniques play a major role in solving problems related to viscoelastic composites due to the complexities inherent to these materials. In this paper, a numerical procedure for multiscale modeling of impact on heterogeneous viscoelastic solids containing evolving microcracks is proposed in which the (global scale) homogenized viscoelastic incremental constitutive equations have the same form as the local‐scale viscoelastic incremental constitutive equations, but the homogenized tangent constitutive tensor and the homogenized incremental history‐dependent stress tensor at the global scale depend on the amount of damage accumulated at the local scale. Furthermore, the developed technique allows the computation of the full anisotropic incremental constitutive tensor of viscoelastic solids containing evolving cracks (and other kinds of heterogeneities) by solving the micromechanical problem only once at each material point and each time step. The procedure is basically developed by relating the local‐scale displacement field to the global‐scale strain tensor and using first‐order homogenization techniques. The finite element formulation is developed and some example problems are presented in order to verify the approach and demonstrate the model capabilities. Copyright © 2009 John Wiley & Sons, Ltd.
Non‐coding RNAs: regulators of disease
Authors: Taft Ryan J , Pang Ken C , Mercer Timothy R , Dinger Marcel , Mattick John S
Published: October 2009

For 50 years the term ‘gene’ has been synonymous with regions of the genome encoding mRNAs that are translated into protein. However, recent genome‐wide studies have shown that the human genome is pervasively transcribed and produces many thousands of regulatory non‐protein‐coding RNAs (ncRNAs), including microRNAs, small interfering RNAs, PIWI‐interacting RNAs and various classes of long ncRNAs. It is now clear that these RNAs fulfil critical roles as transcriptional and post‐transcriptional regulators and as guides of chromatin‐modifying complexes. Here we review the biology of ncRNAs, focusing on the fundamental mechanisms by which ncRNAs facilitate normal development and physiology and, when dysfunctional, underpin disease. We also discuss evidence that intergenic regions associated with complex diseases express ncRNAs, as well as the potential use of ncRNAs as diagnostic markers and therapeutic targets. Taken together, these observations emphasize the need to move beyond the confines of protein‐coding genes and highlight the fact that continued investigation of ncRNA biogenesis and function will be necessary for a comprehensive understanding of human disease. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Unravelling the genetic basis of renal diseases; from single gene to multifactorial disorders
Authors: McKnight Amy J , Currie Diane , Maxwell Alexander P
Published: October 2009

Chronic kidney disease is common with up to 5% of the adult population reported to have an estimated glomerular filtration rate of < 60 ml/min/1.73 m2. A large number of pathogenic mutations have been identified that are responsible for ‘single gene’ renal disorders, such as autosomal dominant polycystic kidney disease and X‐linked Alport syndrome. These single gene disorders account for < 15% of the burden of end‐stage renal disease that requires dialysis or kidney transplantation. It has proved more difficult to identify the genetic susceptibility underlying common, complex, multifactorial kidney conditions, such as diabetic nephropathy and hypertensive nephrosclerosis. This review describes success to date and explores strategies currently employed in defining the genetic basis for a number of renal disorders. The complementary use of linkage studies, candidate gene and genome‐wide association analyses are described and a collation of renal genetic resources highlighted. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.