bluuebunny/crossref_metadata_2025 huggingface dataset:
A distinct DNA methylation profile associated with microsatellite and chromosomal stable sporadic colorectal cancers
Authors: Silver Andrew , Sengupta Neel , Propper David , Wilson Peter , Hagemann Thorsten , Patel Asif , Parker Alexandra , Ghosh Anil , Feakins Roger , Dorudi Sina , Suraweera Nirosha
Published: March 2011

Aberrant DNA methylation, microsatellite instability (MSI) and chromosomal instability (CIN) are well‐characterised molecular features of sporadic colorectal cancers (CRCs). In addition to CpG island methylator phenotype (CIMP) associated with MSI, an intermediate methylation subgroup is also a feature of non‐MSI cancers. A large proportion of CRCs have no evidence of either MSI or CIN, here called Microsatellite and Chromosomal Stable (MACS), and require their methylation profile to be established. The clinical and molecular features of 170 sporadic CRC patients were investigated and stratified into MSI, CIN and MACS groups. MACS were most often found in the left colon and had a significantly lower BRAF mutation frequency (p < 0.001) compared with MSI. MACS had better survival [hazard ratio (HR) = 0.244, p = 0.017] compared with CIN, but were similar to MSI. The methylation status of 1,505 CpG loci from cancer‐related genes was analysed in a subset of CRCs (n = 44 normal–tumour pairs) and compared with CIN, MSI and MACS status. Using two‐way hierarchical clustering, three subgroups were identified, which associated with CIN, MSI and MACS status. Using significance analysis of microarray, 16 CpG loci demonstrating methylation changes associated with MACS were identified. A combination of six loci identified MACS with 81% sensitivity and 93% specificity. This result now requires independent validation. Hypomethylation of a CpG locus within the sonic hedgehog (SHH) promoter correlated with increased gene expression and was associated significantly with MACS cancers. In conclusion, we propose that MACS have distinct clinicopathological features and can be distinguished from other CRCs by a specific set of methylation loci.
FARMERS' PRACTICES AND COMMUNITY MANAGEMENT OF IRRIGATION: WHY DO THEY NOT MATCH IN FATNASSA OASIS?
Authors: Ghazouani Wafa , Marlet Serge , Mekki Insaf , Harrington Larry W. , Vidal Alain
Published: April 2011

Community‐managed irrigation systems are commonly faced with problems of low system‐level performance. A comprehensive survey was undertaken to assess and quantify the causes of the low irrigation performance in a community‐managed oasis in southern Tunisia. At the irrigation system level, results showed that irrigation intervals were double those that had been expected (19–21 days). The main cause was inappropriate farmers' practices at field level where the irrigation duration was almost twice the expected 10 h ha‐1. The extension of date palm plantation and technical dysfunctions played a less important role as they were counterbalanced by cancellation of irrigation in some plots. At the field scale, excessively long irrigation duration resulted from the joint effects of small fields, poor maintenance of field‐level water delivery systems, uncontrolled night irrigation events and low farmer commitment. This situation emphasizes the question of efficiency and sustainability of irrigation systems when farmers subvert collective rules. Further, the situation raises the question of equity among farmers which hinders their support for the water users' association and the strict application of water allocation rules. These findings should help identify an appropriate approach and lead to positive changes in the management of community irrigation systems. Copyright © 2011 John Wiley & Sons, Ltd.
Nanometer‐scale imaging by the modulation tracking method
Authors: Lanzano Luca , Digman Michelle A. , Fwu Peter , Giral Hector , Levi Moshe , Gratton Enrico
Published: April 2011

We developed an optical imaging method based on a feedback principle in which the specific scan pattern is adapted according to the shape of the sample. The feedback approach produces nanometer‐resolved 3D images of very small and moving features in live cells in seconds. We show images of microvilli in live cultured opossum kidney cells expressing NaPi co‐transporter proteins with different GFP constructs and images of cell protrusions in a collagen matrix with a resolution of about 20 nm. We found that in the microvilli the NaPi proteins can be found clustered. Along cell protrusions in 3D we identified cellular adhesions to the extracellular matrix. Our approach to super‐resolution and to 3D nanoimaging is different than other proposed methods that break the diffraction limit using non‐linear effects or are based on single molecule localization. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Successful treatment of patients with systemic lupus erythematosus complicated with autoimmune thyroid disease using double‐filtration plasmapheresis: A retrospective study
Authors: Liu Lin‐Lin , Li Xiao‐Li , Wang Li‐Ning , Yao Li , Fan Qiu‐Ling , Li Zi‐Long
Published: April 2011

Introduction:

Systemic lupus erythematosus (SLE) associated with autoimmune thyroid disease (AITD) is a complex and well recognized autoimmune disorder. Careful monitoring/surveillance of thyroid gland functioning and active treatment of SLE patients with coexisting AITD, typically using medications, are critically important. The role of apheresis in this setting remains to be fully explored. Here we examine the use of double‐filtration plasmapheresis (DFPP), as an adjuvant therapy in the treatment of patients with SLE complicated with AITD and report our experiences using this apheresis methodology.

Methods:

We performed a retrospective chart review of 11 patients with SLE complicated with AITD who had received DFPP in our blood purification center between 2004 and 2008. Levels of thyroid hormones, antithyroid autoantibodies, SLE disease activity, proteinuria, glomerular filtration rate (GFR), and response to therapy were analyzed.

Results:

AITD, SLE, and lupus nephritis improved after DFPP. Except for one patient who died of severe pneumonia in the second month after completion of DFPP, all surviving patients continued to show clinical improvements or remained stable during the follow‐up periods.

Conclusion:

DFPP can effectively remove autoantibodies and may have an important adjuvant role in therapeutic options in the treatment of SLE patients with AITD complications. J. Clin. Apheresis, 2011. © 2011 Wiley‐Liss, Inc.
Accurate bond dissociation enthalpies by using doubly hybrid XYG3 functional
Authors: Zhang Igor Ying , Wu Jianming , Luo Yi , Xu Xin
Published: March 2011

In this work, we examine the performance of XYG3, a newly developed doubly hybrid density functional (Zhang, Xu, and Goddard III, Proc Natl Acad Sci USA 2009, 106, 4963), to calculate covalent bond dissociation enthalpy (BDE). We use 5 atoms, 32 molecular radicals, and 116 closed‐shell molecules to set up 142 bond dissociation reactions. For the total of 148 heats of formation (HOFs) and 142 BDEs, XYG3 leads to mean absolute deviations (MADs) of 1.45 and 1.87 kcal/mol, respectively. In comparison with some other functionals, MADs for HOFs are 2.31 (M06‐2X), 2.98 (B2PLYP‐D), 3.04 (BMK), 3.96 (B3LYP), 4.47 (B2PLYP), 5.42 (B2GP‐PLYP), 6.46 (PBE0), and 29.93 kcal/mol (B3P86), and the corresponding errors for BDEs are 2.06 (M06‐2X), 2.25 (BMK), 2.51 (B2PLYP‐D), 2.89 (B2GP‐PLYP), 3.30 (B3P86), 3.44 (B2PLYP), 3.87 (PBE0), and 6.14 kcal/mol (B3LYP). © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
An ab initio molecular orbital study of intramolecular hydrogen bonding in ortho‐substituted arylamides: Implications for the parameterization of molecular mechanics force fields
Authors: Liu Zhiwei , Teslja Alexey , Pophristic Vojislava
Published: April 2011

The aromatic oligoamide (arylamide) foldamer class, characterized by the repetitive aromatic‐amide pattern, is one of the most intensively studied foldamer families. In this article, the potential energy profiles with regard to torsional motions around the two types of aromatic‐amide bonds (CaCp and CaN) are obtained at the B3LYP/6‐311G(d,p) level of theory. The effect of ortho substituents with different hydrogen bonding abilities (OCH3 vs. SCH3) on the torsional potential profiles is analyzed in detail. There are several findings that have implications in foldamer design. The ortho‐SCH3 substituent on the benzene ring produces a much more flexible arylamide backbone with respect to the OCH3 substituent, as it restricts the CaCp torsion to a lesser extent. Interestingly, the rigidifying effect of the ortho‐SCH3 substituent on the CaN torsion is very similar to that of the OCH3 substituent on the same linkage type. In addition, the SCH3 substituent prefers a perpendicular orientation with respect to the benzene ring to the in‐plane one. It is also found that reparameterization of the corresponding torsional parameters, sometimes specific to the ortho substituent type, in the general amber force field is necessary for an accurate description of the backbone torsions in arylamides. Six sets of partial charge/torsional parameters for each linkage (CaCp or CaN)/substituent (OCH3 or SCH3) combination are obtained based on the ab initio torsional profiles. Initial assessments of these parameters show good agreement with the ab initio results. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Evolutionary history of Cuban crocodiles Crocodylus rhombifer and Crocodylus acutus inferred from multilocus markers
Authors: Milián‐García Yoamel , Venegas‐Anaya Miryam , Frias‐Soler Roberto , Crawford Andrew J. , Ramos‐Targarona Roberto , Rodríguez‐Soberón Roberto , Alonso‐Tabet Manuel , Thorbjarnarson John , Sanjur Oris I. , Espinosa‐López Georgina , Bermingham Eldredge
Published: April 2011

Among crocodilians, Crocodylus rhombifer is one of the world's most endangered species with the smallest natural distribution. In Cuba, this endemic species coexists with the American crocodile (Crocodylus acutus). Hybridization between these two species is well known in captivity and might occur in the wild, but has never been demonstrated genetically. Here, we combined molecular data with environmental, geographic, and fossil data to infer the evolutionary history of Crocodylus in the Cuban Archipelago, and to evaluate genealogical support for species boundaries. We analyzed seven microsatellite loci plus DNA sequence data from nuclear (RAG‐1) and mitochondrial (cytochrome b and cytochrome oxidase I) genes from 89 wild‐caught individuals in Cuba, Grand Cayman Island, Jamaica, and Central America, and two samples from zoo collections. Microsatellites showed evidence of introgression, suggesting potential hybridization among Cuban groups. In Cuba, C. acutus contained one mitochondrial DNA (mtDNA) haplotype, whereas C. rhombifer contained two haplotypes. MtDNA data showed that C. acutus is paraphyletic with respect to C. rhombifer, revealing 1% sequence divergence between species within Cuba vs. 8% divergence between Cuban forms and mainland C. acutus. We suggest that hybridization has been a historical as well as a current phenomenon between C. acutus and C. rhombifer. These findings suggest that long‐term conservation of crocodiles in Cuba will require identification of genetically pure and hybrid individuals, and a decrease in anthropogenic activities. We also recommend more extensive morphological and genetic analyses of Cuban population to establish clear boundaries of the hybrid zone between C. acutus and C. rhombifer. J. Exp. Zool. 315:358–375, 2011. © 2011 Wiley‐Liss, Inc.
Novel isoforms of heat shock transcription factor 1 are induced by hypoxia in the Pacific oyster Crassostrea gigas
Authors: Kawabe Shinya , Yokoyama Yoshihiro
Published: March 2011

The Pacific oyster Crassostrea gigas inhabits the intertidal zone and shows tolerance to various stress conditions such as hypoxia and heat shock. However, little is known about the cellular mechanism of responses to these stresses. Heat shock transcription factor 1 (HSF1) regulates the transcription of several genes, including heat shock proteins (HSPs). In this study, we cloned HSF1 from the oyster and investigated its response to air‐exposure. The cDNA of oyster Hsf1 contains 2,931 bp, of which 1,389 bp encode a protein of 463 amino acid residues. Moreover, we found that the oyster has seven novel alternatively spliced isoforms, Hsf1b–h, consisting of insertion A with 48 bp, insertion B with 42 bp and/or insertion C with 42 bp. We determined the sequences of oyster genomic DNA containing Hsf1 insertions A, B and C. The results indicated that eight isoforms of Hsf1 are generated from a single Hsf1 gene by alternative splicing without frameshifting. Real‐time PCR analysis showed that Hsf1a is expressed constitutively, and the expression of Hsf1b‐h and Hsp70 mRNA is induced by air exposure and/or hypoxia. In addition, we found that 11 putative hypoxia response elements, which are hypoxia‐inducible factor 1 (HIF‐1) binding sequences, are located in the Hsf1 promoter region. These data suggest that the oyster has an HIF‐HSF pathway in which HSPs are induced in an HIF‐dependent manner, and that it also has a novel mechanism of alternative splicing of Hsf1 in response to hypoxia. J. Exp. Zool. 315:394–407, 2011. © 2011 Wiley‐Liss, Inc.
Evolution of pleiotropy: epistatic interaction pattern supports a mechanistic model underlying variation in genotype–phenotype map
Authors: Pavlicev Mihaela , Norgard Elizabeth A. , Fawcett Gloria L. , Cheverud James M.
Published: April 2011

The genotype–phenotype (GP) map consists of developmental and physiological mechanisms mapping genetic onto phenotypic variation. It determines the distribution of heritable phenotypic variance on which selection can act. Comparative studies of morphology as well as of gene regulatory networks show that the GP map itself evolves, yet little is known about the actual evolutionary mechanisms involved. The study of such mechanisms requires exploring the variation in GP maps at the population level, which presently is easier to quantify by statistical genetic methods rather than by regulatory network structures. We focus on the evolution of pleiotropy, a major structural aspect of the GP map. Pleiotropic genes affect multiple traits and underlie genetic covariance between traits, often causing evolutionary constraints. Previous quantitative genetic studies have demonstrated population‐level variation in pleiotropy in the form of loci, at which genotypes differ in the genetic covariation between traits. This variation can potentially fuel evolution of the GP map under selection and/or drift. Here, we propose a developmental mechanism underlying population genetic variation in covariance and test its predictions. Specifically, the mechanism predicts that the loci identified as responsible for genetic variation in pleiotropy are involved in trait‐specific epistatic interactions. We test this prediction for loci affecting allometric relationships between traits in an advanced intercross between inbred mouse strains. The results consistently support the prediction. We further find a high degree of sign epistasis in these interactions, which we interpret as an indication of adaptive gene complexes within the diverged parental lines. J. Exp. Zool. (Mol. Dev. Evol.) 316:371–385, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis of spiro thiazolo[3,2‐a]pyrimidine compounds by one‐pot sequential 1,3‐dipolar cycloadditions
Authors: Li Xiaofang , Zheng Aiting , Liu Bin , Li Guobin , Yu Xianyong , Yi Pinggui
Published: April 2011

A new class of spiro thiazolo[3,2‐a]pyrimidine compounds were synthesized by the one‐pot sequential 1,3‐dipolar cycloaddition of azomethine ylide (generated from isatin and sarcosine)–nitrile oxide to 2‐arylmethylidene‐6,7‐dihydro‐5H‐thiazolo[3,2‐a]pyrimidin‐3‐ones in moderate yields. The structures of all the products were characterized thoroughly by NMR, MS, IR, elemental analysis, and NMR together with X‐ray crystallographic analysis. J. Heterocyclic Chem., (2011).
7‐Azacinnolin‐4(1H)‐one preparation and NMR studies of tautomery
Authors: Stockmann Vegar , Primpke Sebastian , Fiksdahl Anne
Published: March 2011

As part of our current investigations of nitropyridines, we hereby report the preparation of a new annulated heterocycle by C‐azo coupling. Thus, the azacinnoline, pyrido[3,4‐c]pyridazin‐4(1H)‐one (38%), was prepared from 4‐acetyl‐3‐aminopyridine via diazotization. 1H, 13C, and 15N NMR spectroscopic investigations revealed that the azacinnoline exclusively exists in the NH‐keto tautomeric form in DMSO‐d6, CD3OD, and D2O. J. Heterocyclic Chem., (2011).
Relationship between daily atmospheric circulation types and winter dry/wet spells in western Iran
Authors: Raziei Tayeb , Bordi Isabella , Pereira Luis S. , Corte‐Real João , Santos João A.
Published: April 2011

Aiming at better understanding the causes and processes leading to meteorological dry and wet episodes in western Iran, the present study investigates the space and time variability of winter dry/wet events and their associated large‐scale atmospheric driving circulations. Using monthly precipitation data of 140 weather stations for 1965–2000, meteorological dry/wet spells are assessed through the 1‐month Standardized Precipitation Index (SPI). By applying the Principal Component Analysis (PCA) with Varimax rotation to the SPI field, three sub‐regions of independent climatic variability are identified. Large‐scale daily atmospheric circulation patterns are then classified into twelve circulation types (CTs) by applying PCA to the 500 hPa geopotential height fields coupled with the non‐iterative K‐means clustering technique, in which extreme rotated principal component scores, in their positive and negative phases, are considered as potential groups and their centroids are computed by averaging all days that fulfil the extreme score criterion. The linkage between daily CTs and winter dry/wet spells in the region is investigated by correlating the frequencies of occurrence of each CT with the time series of dry/wet events, derived from both the rotated principal component scores of SPI and the SPI series at three representative stations of the identified sub‐regions. Severe/extreme events have also been considered. A performance index is applied to test the relationship between CTs and dry/wet events. Results show statistically significant correlations between the frequencies of occurrence of the identified CTs and of dry/wet spells at the three representative stations, suggesting that particular CTs are potential predictors for the winter dry/wet events in western Iran. Copyright © 2011 Royal Meteorological Society
Simulation of fracture healing in the tibia: Mechanoregulation of cell activity using a lattice modeling approach
Authors: Byrne Damien P. , Lacroix Damien , Prendergast Patrick J.
Published: April 2011

In this study, a three‐dimensional (3D) computational simulation of bone regeneration was performed in a human tibia under realistic muscle loading. The simulation was achieved using a discrete lattice modeling approach combined with a mechanoregulation algorithm to describe the cellular processes involved in the healing process—namely proliferation, migration, apoptosis, and differentiation of cells. The main phases of fracture healing were predicted by the simulation, including the bone resorption phase, and there was a qualitative agreement between the temporal changes in interfragmentary strain and bending stiffness by comparison to experimental data and clinical results. Bone healing was simulated beyond the reparative phase by modeling the transition of woven bone into lamellar bone. Because the simulation has been shown to work with realistic anatomical 3D geometry and muscle loading, it demonstrates the potential of simulation tools for patient‐specific pre‐operative treatment planning. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1496–1503, 2011
Assessment of the profiling MicroRNA expression of differentiated and dedifferentiated human adult articular chondrocytes
Authors: Lin Lin , Shen Qi , Zhang Chenguang , Chen Lianxu , Yu Changlong
Published: April 2011

MicroRNA has an important role in regulating gene expression during cell differentiation. In this study we identified the expression pattern of microRNA in the differentiated and dedifferentiated chondrocytes. Adult human articular chondrocytes were cultured in monolayer. RNA was isolated from the differentiated chondrocytes (collected after isolation) and the fifth‐passage (dedifferentiated) chondrocytes, and subjected to gene expression analysis using microRNA and cDNA microarray analysis. Real‐time RT‐PCR was also performed to confirm the differentially expressed genes. Furthermore, we integrated microRNA and cDNA microarray data together with computational approaches, such as microRNA gene target prediction algorithms, to reveal the role of microRNAs involved in chondrocyte homeostasis. The results showed a dramatic change in expression of microRNA between the two cell types. Thirteen up‐regulated and 12 down‐regulated microRNAs were detected in differentiated chondroctes. We also revealed microRNA–gene target pairs potentially involved in dedifferentiation process. Our results revealed novel findings of differential expression of microRNA in dedifferentiation, and microRNA could have an important role in the maintenance of chondrocytes homeostasis. MicroRNA may be a target for cartilage tissue engineering and regenerative medicine. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1578–1584, 2011
Noninvasive molecular identification of particulate matter in lungs by Raman microspectrometry
Authors: Falgayrac Guillaume , Chérot‐Kornobis Nathalie , Broucker Virginie de , Hulo Sébastien , Edmé Jean‐Louis , Sobaszek Annie , Penel Guillaume
Published: April 2011

A new method for the analysis of particulate matter in lungs is proposed. It combines the exhaled breath condensate technique and Raman spectroscopy. The sampling method is noninvasive, which is suitable for the detection of occupational exposure to dust. The chemical composition of dust particles is assessed by Raman microspectroscopy. The effectiveness of this method as a means of identifying markers of occupational exposure to mica dust is evaluated. Copyright © 2011 John Wiley & Sons, Ltd.
Study of Raman spectrum of uranium using a surface‐enhanced Raman scattering technique
Authors: Ravindran T. R. , Arora A. K.
Published: April 2011

Raman spectroscopic investigation on weak scatterers such as metals is a challenging scientific problem. Technologically important actinide metals such as uranium and plutonium have not been investigated using Raman spectroscopy possibly due to poor signal intensities. We report the first Raman spectrum of uranium metal using a surface‐enhanced Raman scattering‐like geometry where a thin gold overlayer is deposited on uranium. Raman spectra are detected from the pits and scratches on the sample and not from the smooth polished surface. The 514.5‐ and 785‐nm laser excitations resulted in the Raman spectra of uranium metal whereas 325‐nm excitation did not give rise to such spectra. Temperature dependence of the B3g mode at 126 cm−1 is also investigated. Copyright © 2011 John Wiley & Sons, Ltd.
Spectroscopic investigations and computational study of sulfur trioxide–pyridine complex
Authors: Anto P. L. , Anto Ruby John , Varghese Hema Tresa , Panicker C. Yohannan , Philip Daizy , Andrade Gustavo F. S. , Brolo Alexandre G.
Published: April 2011

The Fourier transform infrared (FT‐IR) and FT‐Raman spectra of sulfur trioxide‐pyridine complex were recorded and analyzed. The potential‐dependent surface‐enhanced Raman scattering (SERS) was recorded from an electrochemically roughened silver electrode. The vibrational wave numbers of the compound were computed using the Hartree–Fock/6‐31G* basis and compared with the experimental values. The presence of strong pyridine ring vibrations in the SERS spectrum reveals the interaction between the pyridine ring and the silver surface. The molecule is adsorbed on the silver surface with the pyridine ring in a tilted orientation. The direction of charge‐transfer contribution to the SERS is discussed from the frontier orbital theory. The value of the calculated first hyperpolarizability is comparable to those reported for similar structures, which makes this molecule an attractive object for future studies of nonlinear optics. The optimized geometrical parameters of the title compound are in agreement with similar reported structures. Copyright © 2011 John Wiley & Sons, Ltd.
SERS detection of explosive agent by macrocyclic compound functionalized triangular gold nanoprisms
Authors: Xu Jing Yao , Wang Jin , Kong Ling Tao , Zheng Guang Chao , Guo Zheng , Liu Jin Huai
Published: April 2011

Triangular gold nanoprisms with high yield percentage were synthesized via the seed‐mediated approach and functionalized by mono‐6‐thio‐β‐cyclodextrin without alkyl chain. The undecorated and decorated triangular gold nanoprisms were characterized and analyzed. Moreover, the novel decorated triangular gold nanoprisms were used as surface‐enhanced Raman spectroscopy (SERS) substrates for chemical sensing of the explosive agent 2,4‐dinitrotoluene (DNT). The vibrational bands in the experimental SERS spectrum were assigned with the aid of density functional theoretical simulation. The analytical enhancement factor of the hybridized triangular gold nanoprisms for the detection of DNT has been obviously increased in contrast with hybridized spherical gold nanoparticles, suggesting that the former are excellent SERS substrates. Compared to some other approaches, the limit of detection can be remarkably improved (qualified as sub‐ppb level), which indicates that the excellent chemical sensing of decorated triangular gold nanoprisms can be widely applied to trace analysis of explosive or warfare agents. Copyright © 2011 John Wiley & Sons, Ltd.
Using Raman spectroscopy as a tool for the detection of iron in glass
Authors: Baert K. , Meulebroeck W. , Wouters H. , Cosyns P. , Nys K. , Thienpont H. , Terryn H.
Published: April 2011

Raman spectroscopy has been used to identify iron‐containing glasses. This nondestructive technique offers a fast method to obtain qualitative information about the presence of iron oxides in glass. The effect of the iron content in glass samples is reflected on the topology of the Raman spectra: A strong link between the ratio of the Q2/Q3 vibration units of the silica tetrahedral structure is seen. If matrix effects are taken into account, also (semi)quantitative results can be obtained from the calibration lines. The linear calibration is based on the normalized band intensity at 980 cm−1 (I980/I1090) and the iron oxide concentration for similar glasses. In amber and dark colored glasses, an extra peak in the spectrum indicates the presence of a FeS chromophore. Different series of glasses of various origins (ancient and modern/industrial glass) have been considered. Copyright © 2011 John Wiley & Sons, Ltd.
An overview of the use of monoliths in sample preparation and analysis of milk
Authors: Samanidou Victoria F. , Karageorgou Eftichia G.
Published: April 2011

Monolithic columns with a unique structure possess some exceptional characteristics, which make them an excellent tool in the hands of analytical chemists, not only for separation but also for sample preparation. Their much higher external porosity compared to conventional particle‐packed columns results in higher permeability and low‐pressure drop with higher separation efficiency. Till now, monolithic columns have been applied to the analysis of different analytical matrices: pharmaceuticals, biofluids, food matrices, environmental samples, biochemical species, proteomics, etc. Since they offer a great potential for the separation of complex mixtures, it can be expected that the interest in applying these columns will increase. As long as more experience is gained with monolithic column technology, the emergence of applications is expected to continue. The need of reduction in organic solvent consumption also justifies this trend, in the frame of environmentally friendly methods. More and more applications using monolithic columns arise. In the future, monolithic columns are expected to prevail especially in the field of miniaturization and in chip‐based nano‐LC systems. In this review, we try to summarize any attempt that has been reported in the analysis of a sample of great complexity like milk using the technology of the monoliths.
Nanostructured Interpenetrating Polymer Network (IPN) Precursor Ultrathin Films
Authors: Waenkaew Paralee , Taranekar Prasad , Jiang Guoqian , Huang Cheng Yu , Fulghum Timothy , Patton Derek , Jayarathna Lalithya , Phanichphant Sukon , Advincula Rigoberto C.
Published: March 2011

The formation of a nanostructured interpenetrating polymer network (IPN) via electropolymerization is described. The electro‐copolymerization of alternate layer‐by‐layer (LbL) self‐assembled polyelectrolytes with thiophene and carbazole pendant monomers was demonstrated facilitating IPN formation of π‐conjugated polymers or conjugated polymer network (CPN) films. UV–Vis spectroscopy, QCM, and ellipsometry confirmed linear nanostructured LbL film growth. Electrochemical crosslinking by cyclic voltammetry (CV) manifested highly regular peak current increases with successive cycles. A quantitative correlation of the LbL layer number with the cathodic charge and scan rate was observed. Electrochemical impedance analysis confirmed CPN film formation and the change in capacitance behavior.

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1,2,3‐Triazole‐Incorporated Diacrylate Monomer for Free Radical Cyclopolymerization Through Large Ring Formation
Authors: Li Changlin , Liu Hewen , Li Yuesheng
Published: March 2011

A new 1,2,3‐triazole incorporated diacrylate monomer is designed for free radical cyclopolymerization through the formation of 11‐membered rings. NMR analysis on the cyclopolymers including 1H, 13C, DEPT‐135, and 1H–13C HMQC spectra support a high degree of cyclization. GPC profiles of the obtained cyclopolymers show unimodal distributions indicative of no chain branching reactions.

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An empirical assessment of cross‐cultural age self‐construal measurement: Evidence from three countries
Authors: Barak Benny , Guiot Denis , Mathur Anil , Zhang Yong , Lee Keun
Published: April 2011

This study investigated which age measures, independent or interdependent, were better for cross‐cultural consumer research. Specifically, it assessed the fit between the “actual” and “ideal” self‐concept model within the framework of self‐construal theory by examining the actual and ideal self‐attributed age identity across South Korea (n = 480), China (n = 207), and France (n = 338) using both independent and interdependent age identity scales. Multivariate analyses revealed differences for individuated self‐schemata across the three countries for actual and ideal age self‐construal, as well as for actual other‐referent interdependent age self‐schemata. However, the reverse occurred too: The ideal interdependent ages showed a lack of difference across the three different cultures. Overall, the results indicate that interdependent decade scales are better than independent age scales for cross‐cultural consumer behavior studies. Though such scales are more complex, they are easy to translate and to administer, and simple to analyze and to interpret. Evidence also suggests that such scales are reliable and robust across disparate samples in the countries studied. © 2011 Wiley Periodicals, Inc.
Quantum Chemistry: A Powerful Tool in Polymer Reaction Engineering
Authors: Dossi Marco , Storti Giuseppe , Moscatelli Davide
Published: March 2011

Summary: The potentials of computational techniques based on quantum mechanics, to support and complement the experimental analysis, are examined. Mechanisms and reaction paths involved in the free radical polymerization of widely used monomers are studied through a computational approach based on Density Functional Theory (DFT). First, the attention is focused on the initiation kinetics in order to evaluate the role of the initiators in the polymerization process. Methyl acrylate, methyl methacrylate, acrylonitrile, and styrene homopolymerization using different initiators are studied. Then, propagation kinetics is investigated. In particular, the propagation kinetic rate constants for different kinds of acrylates, methacrylates and acetates are calculated and compared with experimental data reported in the literature. The same computational approach is applied to the study of secondary reactions (backbiting, beta‐scission) occurring during free radical polymerizations. Finally, the same methodologies are applied to copolymer systems, with emphasis on the evaluation of the role of penultimate effect. The copolymers vinyl acetate/methyl methacrylate and styrene/methyl methacrylate are investigated as system characterized by weak and strong penultimate effect, respectively.
Ethylene Polymerization by Metallocene Catalysts Supported over Siliceous Materials with Bimodal Pore Size Distribution
Authors: Moreno Jovita , van Grieken Rafael , Carrero Alicia , Paredes Beatriz
Published: March 2011

Summary: As known, the pore structure of the catalytic support plays a decisive role during the polymerization reactions determining intra‐particle mass and heat transport phenomena. In this work, several ethylene polymerizations have been carried out by using as catalytic support different mesostructured materials with unimodal and bimodal pore size distributions in order to evaluate the influence of this pore size distribution on the catalytic behavior. Calcined mesoporous materials were impregnated with the catalytic system MAO/(nBuCp)2ZrCl2 and used for ethylene polymerization and ethylene/1‐hexene copolymerizations, at 70 °C and 5 bar of ethylene pressure. Polyethylenes obtained were characterized by GPC, DSC and Crystaf. Results indicate that porous structure of the support has a significant influence on polymerization activity and polymer properties. Despite the catalyst bimodal pore size distribution, only ethylene/1‐hexene copolymers presented a bimodal chemical composition distribution.
Tailoring MWD of Bimodal Polyethylene in the Presence of Ziegler‐Natta Catalyst
Authors: Hakim Shokoufeh , Moballegh Leila
Published: March 2011

Summary: Linear poly (ethylene‐co‐1‐butene) was produced through two‐step polymerization in one reactor using a Ziegler‐Natta catalyst, where in the first step, low molecular weight homopolymer of ethylene in the presence of hydrogen and in the next step, high molecular weight copolymer of ethylene with 1‐butene in the absence of hydrogen were produced. Molecular weight distribution of bimodal polyethylene was tailored through adjustment of polymerization time of each stage and hydrogen concentration of the first stage. Increasing hydrogen concentration shifted the molecular weight distribution curve to the lower molecular weights and broadened molecular weight distribution while interestingly increased high molecular weight incorporation of copolymer produced in the second stage due to increasing of reaction rate in the second step. To achieve bimodal molecular weight distribution, the polymerization times of the first and the second steps, which are highly dependent on the amount of hydrogen, were adjusted properly. The effects of the mentioned parameters on the processability as well as rheological properties of some samples were investigated. The rheological results showed shear thinning behavior of all specimens and confirmed the changes in molecular weight and molecular weight distribution. It was also demonstrated that the melt miscibility between low molecular weight and high molecular weight fractions improved with increasing of chains having very low molecular weight.
Modelling of PET Quality Parameters for a Closed‐Loop Recycling System for Food Contact
Authors: Rieckmann Thomas , Frei Fabian , Völker Susanne
Published: March 2011

Summary: A rigorous process model has been developed which describes a closed‐loop recycling system for PET beverage bottles. The reaction / mass transport model is aimed at the dominant quality parameters such as intrinsic viscosity, concentration of acetaldehyde, concentration of carboxylic end‐groups, and concentration of vinyl end‐groups, respectively. The model covers the main process steps being preform production (injection moulding), drying, solid‐state polycondensation, and melt filtration. The simulation reveals that after a single recycling loop all the relevant quality parameters achieve the specification, if certain temperatures, residence times, and surface areas for degassing are provided during the recycling process. Another simulation showed the evolution of quality parameters in PET being subjected to an “infinite” number of recycling loops in a closed system. In this case, the concentration of acetaldehyde and vinyl end‐groups decreases with the number of recycling loops, which is a desired effect. On the other hand, the concentration of carboxylic end‐groups increases with every completed recycling loop. Higher concentrations of carboxylic end‐groups make the polymer more susceptible to hydrolysis and increase the SSP process time needed to achieve the specified intrinsic viscosity for carbonated soft drink bottles. To overcome this problem, the recycled PET has to be blended with a certain amount of virgin PET in industrial processes.
Effect of Sodium dodecyl sulfate on the Mass Transfer Rate between Styrene and Water
Authors: Katzer Johannes , Pauer Werner , Moritz Hans‐Ulrich
Published: March 2011

Summary: The effect of sodium dodecyl sulfate (SDS) on the mass transfer rate between styrene and water has been investigated. SDS increases the solubility of styrene in water even below the critical micelle concentration (CMC) and therefore increases the thermodynamic driving force for the mass transfer. The mass transfer coefficient however is not altered by SDS, even if the interface is almost saturated with emulsifier.
Phenotypic spectrum of musician's dystonia: A task‐specific disorder?
Authors: Schmidt Alexander , Jabusch Hans‐Christian , Altenmüller Eckart , Enders Leonie , Saunders‐Pullman Rachel , Bressman Susan B. , Münchau Alexander , Klein Christine , Hagenah Johann
Published: April 2011

Background: Musician's dystonia (MD) is traditionally considered a sporadic and task‐specific movement disorder. Methods: The phenotypic spectrum of the disorder was studied in 116 patients suffering from MD including videotaping. Results: Based on the movement disorders observed, we categorized our patients into two different groups: (i) 65 patients with isolated MD, that is only present when playing the instrument and (ii) 51 patients with MD and one or more additional features of primary dystonia independent of MD (complex MD). Patients with a positive family history of movement disorders had an increased risk to develop complex MD [odds ratio = 4.80; 95% confidence interval: 1.94–11.92; P = 0.001]. Discussion: In previous studies, we recently identified 22 relatives with different types of movement disorders in the families of 28 MD patients. Taken together, our results further support a genetic contribution to MD with a broad individual and familial phenotypic spectrum consisting of MD, other dystonias and even other, non‐dystonic movement disorders. © 2010 Movement Disorder Society
A Combination of Computational and Experimental Approaches to Investigate the Binding Behavior of B.sub Lipase A Mutants with Substrate pNPP
Authors: Ni Zhong , Jin Xin , Zhou Peng , Wu Qi , Lin Xian‐Fu
Published: March 2011

The formation of so‐called enzyme–substrate complex is the key step for a successful enzyme‐catalysis reaction. Enzymes use substrate‐binding energy both to promote ground‐state association and to stabilize the reaction transition state selectively. Some residues besides the catalytic triads play important roles toward the substrate binding process. In this study, we employed ONIOM methodology and docking to explore the influence of individual amino acids of Bacillus subtilis (B.sub) lipase A on the hydrolysis reaction, with the aim to guide mutagenesis experiments on the basis of computational framework. Subsequently, the B.sub lipase A is modified experimentally with different non‐polar residues at the position 12, which is spatially adjacent to the active site, by using site‐directed mutagenesis. We obtain a good correlation model between the computationally predicted binding energies and the experimental measured affinities, with a correlation coefficient r=0.78. It is largely unexplored that the combination of docking and quantum mechanical/molecular mechanical (QM/MM) analyses is used in conjunction with experimental procedure to investigate the enzyme catalysis process. We therefore expect that this work could provide a new pathway for exploring the molecular mechanism of enzyme–substrate recognition and interaction.
Adamantanes as spherical nanosondes in adducts with a chiral dirhodium complex—discriminating enantiomers and probing spatial proximities
Authors: Duddeck Helmut , Tóth Gábor , Simon Andras , Gómez Edison Díaz , Mattiza Jens T.
Published: March 2011

Three different kinds of substituted chiral adamantane molecules—adamantanones, dioxolanoadamantanes and dithiolano—adamantanes—were studied in the dirhodium experiment (NMR measurement with 1:1 molar mixtures with Rh(II)2[(R)‐(+)‐MTPA]4 in CDCl3). Their different behavior in adduct formation is described, and the possibility of determining enantiomeric purities and absolute configurations is explored. Detailed inspection of one‐ and two‐dimensional NMR experiments allowed for an interpretation of steric and electronic intra‐adduct interaction showing that the phenyl groups of Rh* tend to enwrap the bound adamantane ligand so that through‐space effects over a range of 6–7 Å away from the binding rhodium atom can be observed. Even slight differences in the relative orientation of phenyl groups can be monitored when comparing diastereomeric adducts via NMR signal dispersion. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and complete assignment of the 1H and 13C NMR spectra of 6‐substituted and 2,6‐disubstituted pyridazin‐3(2H)‐ones
Authors: Besada Pedro , Costas Tamara , Vila Noemi , Chessa Carla , Terán Carmen
Published: March 2011

Several pyridazin‐3(2H)‐one derivatives were synthesized starting from alkyl furans using oxidation with singlet oxygen to give 4‐methoxy or 4‐hydroxybutenolides, key intermediates of the synthetic strategy followed. For all pyridazinones reported, a complete assignment of the 1H and 13C NMR spectra using one‐ and two‐dimensional NMR spectroscopic methods, which included NOE, DEPT, COSY, HSQC and HMBC experiments, was accomplished. Correlations between the chemical shifts of the heterocyclic ring atoms and substituents at N‐2 and C‐6 were analyzed. Copyright © 2011 John Wiley & Sons, Ltd.
1H and 13C NMR chemical shift assignments of spiro‐cycloalkylidenehomo‐ and methanofullerenes by the DFT–GIAO method
Authors: Khalilov L. M. , Tulyabaev A. R. , Yanybin V. M. , Tuktarov A. R.
Published: March 2011

The 1H and 13C NMR chemical shifts of spiro‐cycloalkylidene[60]fullerenes were assigned using experimental NMR data and the Density Functional Theory (DFT)–Gauge Independence Of Atomic Orbitals method (GAIO) calculation method in the Perdew Burke Ernzerhof (PBE)/3z approach. The calculated values of the 13C NMR chemical shifts adequately reproduce the experimental values at this quantum chemistry approach. Similar assignments will be helpful for 13C NMR spectral analysis of homo‐ and methano[60]fullerene derivatives for structure elucidation and to determine the influence of fullerene frames on substituents and the influence of substituents on fullerene cores. Copyright © 2011 John Wiley & Sons, Ltd.
Aberrant splicing in the LMNA gene caused by a novel mutation on the polypyrimidine tract of intron 5
Authors: Carboni Nicola , Floris Matteo , Mateddu Anna , Porcu Maurizio , Marrosu Giovanni , Solla Elisabetta , Cocco Eleonora , Mura Marco , Marini Stefano , Maioli Maria A. , Piras Rachele , Aste Rinaldo , Marrosu Maria G.
Published: April 2011

Introduction: Familial dilated cardiomyopathy with conduction system defects variably associated with skeletal muscle abnormalities is frequently caused by LMNA gene mutations. Methods: A family affected by cardiac abnormalities, either isolated or variably associated with skeletal muscle compromise, was identified. LMNA gene analysis was applied to all family members. Results: A novel intron 5 (c.937‐11 C>G) mutation was identified. mRNA transcription analysis was subsequently performed, and cDNA was obtained from mutated patients. It displayed an aberrant splice product featuring the insertion of 40 nucleotides from intron 5, leading to a frameshift. Computational predictions identified a cryptic splice site 40 bp upstream from the canonical site; this alternative splicing event was elicited by intronic mutation, which seems to interfere with the polypyrimidine tract of the canonical site. Conclusions: We have described the first mutation on the LMNA gene interfering with the polypyrimidine tract. Our findings underline the importance of including introns in the search for mutations. Muscle Nerve, 2011
Soluble activin receptor type IIB increases forward pulling tension in the mdx mouse
Authors: George Carlson C. , Bruemmer Kay , Sesti Jenna , Stefanski Casey , Curtis Heather , Ucran Jeffrey , Lachey Jennifer , Seehra Jasbir S.
Published: April 2011

Introduction: In this study we investigated the action of RAP‐031, a soluble activin receptor type IIB (ActRIIB) comprised of a form of the ActRIIB extracellular domain linked to a murine Fc, and the NF‐κB inhibitor, ursodeoxycholic acid (UDCA), on the whole body strength of mdx mice. Methods: The whole body tension (WBT) method of assessing the forward pulling tension (FPT) exerted by dystrophic (mdx) mice was used. Results: RAP‐031 produced a 41% increase in body mass and a 42.5% increase in FPT without altering the FPT normalized for body mass (WBT). Coadministration of RAP‐031 with UDCA produced increases in FPT that were associated with an increase in WBT. Conclusions: Myostatin inhibition increases muscle mass without altering the fundamental weakness characteristic of dystrophic muscle. Cotreatment with an NF‐κB inhibitor potentiates the effects of myostatin inhibition in improving FPT in mdx mice. Muscle Nerve, 2011
Suction‐modified Bergström muscle biopsy technique: Experience with 13,500 procedures
Authors: Tarnopolsky Mark A. , Pearce Erin , Smith Katelyn , Lach Boleslaw
Published: April 2011

Introduction: Bergström needle muscle biopsies have been used by exercise physiologists for over 35 years but have been less accepted by neuromuscular clinicians due to size concerns. Methods: We retrospectively reviewed over 13,500 muscle Bergström needle biopsies done over a 21‐year period to determine sampling success, patient/subject experience, and complications. We compared sample yield between two different needles (Bergström vs. UCH), with and without suction modifications. Results: Needle biopsies adequate for histology and enzymology were obtainable from the vastus lateralis, deltoid, biceps brachii, soleus, and medial gastrocnemius muscles, with a success rate of >99.9% and a minor complication rate of 0.15%. Approximately 450 muscle fibers were submitted for histologic assessment; suction modification and use of the Bergström vs. UCH needle were associated with larger sample size (P < 0.05). Conclusions: The suction‐modified Bergström needle muscle biopsy technique is safe and provides an adequate sample size for histologic, ultrastructural, DNA, and enzyme analysis. Muscle Nerve, 2011