bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rational Synthetic Tuning between Itinerant Antiferromagnetism and Ferromagnetism in the Complex Boride Series Sc2FeRu5−nRhnB2 (0≤n≤5)
Authors: Fokwa Boniface P. T. , Lueken Heiko , Dronskowski Richard 
Published: April 2007

AbstractSingle crystals of the complex boride series Sc2FeRu5−nRhnB2 (n=1, 3, 4) were synthesized by arc‐melting the elements in water‐cooled copper crucibles under argon atmospheres and were chemically characterized by single‐crystal XRD and EDX analyses. The new compounds are isotypic and crystallize in the tetragonal space group P4/mbm with Z=2, adopting a substitutional variant of the Ti3Co5B2‐type structure. The magnetically active iron atoms are arranged in chains with intra‐ and interchain distances of about 3.02 and 6.60 Å, respectively. Strong ferromagnetic interactions are observed for both Sc2FeRuRh4B2 (64 valence electrons (VE), TC≈350 K, μa=3.1 μB) and Sc2FeRu2Rh3B2 (63 VE, TC≈300 K, μa=3.0 μB), whereas antiferromagnetic interactions are found in the case of Sc2FeRu4RhB2 (61 VE, TN≈10 K, μeff=3.2): The magnetism of the entire Sc2FeRu5−nRhnB2 (0≤n≤5) series is discussed based on the variable valence‐electron count and the resulting Fe–Fe bonding character, and it is also compared with other isoelectronic systems.
Electron Transfer and Structural Change: Distinguishing Concerted and Two‐Step Processes
Authors: Macías‐Ruvalcaba Norma A. , Evans Dennis H. 
Published: April 2007

AbstractIn electron‐transfer reactions accompanied by structural changes, the structural change can be concerted with electron transfer or can occur in a separate reaction either preceding or following the electron‐transfer step. In this paper we discuss ways of distinguishing concerted reactions from the latter two‐step type. Included are recent examples in which no intermediates have been detected in the reactions, thus precluding the direct assignment to the two‐step category. In these cases, other means are used to build support for the two‐step mechanism with respect to the concerted process. These include an example of structural change preceding electron transfer, a demonstration that the current models of concerted reactions cannot fit the voltammetric data, and a case in which an independent measure of the inner reorganization energy was used to show that the reaction could not be a concerted electron transfer and structural change.
Numerical solution of the small dispersion limit of Korteweg—de Vries and Whitham equations
Authors: Grava Tamara , Klein Christian 
Published: April 2007

AbstractThe Cauchy problem for the Korteweg—de Vries (KdV) equation with small dispersion of order ϵ2, ϵ ≪ 1, is characterized by the appearance of a zone of rapid, modulated oscillations of wavelength of order ϵ. These oscillations are approximately described by the elliptic solution of KdV where the amplitude, wave number, and frequency are not constant but evolve according to the Whitham equations. In this manuscript we give a quantitative analysis of the discrepancy between the numerical solution of the KdV equation in the small dispersion limit and the corresponding approximate solution for values of ϵ between 10−1 and 10−3. The numerical results are compatible with a difference of order ϵ close to the center within the “interior” of the Whitham oscillatory zone, of order ϵ1/3 at the left boundary outside the Whitham zone and of order √ϵ at the right boundary outside the Whitham zone. © 2007 Wiley Periodicals, Inc.
Stereoselective Electrocatalytic Oxidative Coupling of Phenylacetonitriles: Facile and Convenient Way to trans‐α,β‐Dicyanostilbenes
Authors: Elinson Michail N. , Dorofeev Alexander S. , Feducovich Sergey K. , Belyakov Pavel A. , Nikishin Gennady I. 
Published: April 2007

AbstractElectrolysis of phenylacetonitriles in methanol in an undivided cell in the presence of sodium halides as mediators induces a stereoselective oxidative coupling process that results in the formation of trans‐α,β‐dicyanostilbenes in 60–85 % yield with 40–70 % current efficiency. The application of this efficient stereoselective electrocatalytic method to the formation of trans‐α,β‐dicyanostilbenes represents an environmentally benign synthetic strategy and is valuable from the viewpoint of large‐scale processes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Study of Radical Decarboxylation Toward Functionalization of Naphthoquinones
Authors: Commandeur Claude , Chalumeau Céline , Dessolin Jean , Laguerre Michel 
Published: April 2007

AbstractIn order to obtain functionalized naphthoquinones, a systematic study of the Kochi–Anderson procedure for the alkylation of quinones is presented. While linear amino acids of different lengths were good substrates for this decarboxylation procedure, chiral α‐amino acids were unsuccessful substrates. The best reaction conditions were evaluated with β‐alanine and then applied to a series of carboxylic acids to obtain chemical diversity on the naphthoquinones. We observed that the substitution of the acids is critical for the alkylation, and that it was possible to realize a double alkylation with 1,4‐naphthoquinone, even with different reactants. The Barton procedure was attempted on some substrates to compare with our results, but no reaction was observed, no matter which radical trap was used. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
CEC separation of heterocyclic amines using methacrylate monolithic columns
Authors: Barceló‐Barrachina Elena , Moyano Encarnación , Puignou Lluís , Galceran Maria Teresa 
Published: April 2007

AbstractTwo methacrylate‐based monolithic columns, one with a negatively charged group (sulfonic group) and another with a new monomer N,N‐dimethylamino ethyl acrylate (DMAEA), were prepared and tested for the separation of basic compounds by CEC. This new monolithic stationary phase was prepared by the in situ polymerization of DMAEA with butyl methacrylate and ethylene dimethacrylate, using a ternary porogenic solvent consisting of water, 1‐propanol and 1,4‐butanediol. The performance of this column was evaluated by means of the analysis of a family of heterocyclic amines. Separation conditions such as pH, amount of organic modifier, ionic strength and elution mode (normal or counterdirectional flow) were studied. At the optimal running electrolyte composition, and using the counterdirectional mode, symmetrical electrochromatographic peaks were obtained, with the number of theoretical plates up to 30 000 and a good resolution between closely related peaks. The 2‐acrylamido‐2‐methyl‐1‐propane‐sulfonic acid column was used for CEC‐MS, taking advantage of the compatibility of its elution mode (normal flow) with the MS coupling.
Comparative studies of the interaction between ferulic acid and bovine serum albumin by ACE and surface plasmon resonance
Authors: Zhang Yintang , Xu Maotian , Du Ming , Zhou Feimeng 
Published: April 2007

AbstractAffinity capillary electrophoresis (ACE) was used to study the interaction between ferulic acid (FA) and BSA. The interaction between FA and BSA was facilitated by injecting FA into a BSA‐containing running buffer. Both mobility ratio and mobility shift assays were performed to deduce the binding constant (Kb). However, the Kb value obtained with the mobility ratio assay was only ˜20% of that extracted from the mobility shift assay. The former assay yielded a Kb value (5.6 ± 0.4×104 M–1), which compares well with the result obtained with surface plasmon resonance (SPR) (5.1 ± 0.6×104 M–1). The discrepancy between the mobility ratio and mobility shift assays suggests that the data extrapolation from the mobility ratio should be more reliable for cases when both changes in the EOF and viscosity of the running buffer are important. The work demonstrates that ACE, a solution‐based technique, and SPR, a technique addressing interfacial processes, are highly complementary to each other and the comparative studies are confirmatory and allow binding constants to be accurately determined.
Selbstbewusst und exzellent
Authors: Schorn‐Schütte Luise 
Published: April 2007

AbstractBei der Förderung geisteswissenschaftlicher Forschung geht es um die Bewahrung spezifischer Exzellenzkriterien unter den veränderten Rahmenbedingungen knapper Ressourcen – nicht nur im Jahr der Geisteswissenschaften 2007
Dynamic patterns of latest Proterozoic‐Palaeozoic‐early Mesozoic marine biodiversity in South China
Authors: Jiayu Rong , Junxuan Fan , Miller Arnold I. , Guoxiang Li 
Published: April 2007

AbstractAnalyses of global biodiversity curves have been important for the interpretation of co‐evolution between organisms and environments through geological time. Global curves can be better understood if all the data collected from a multitude of palaeocontinents are analysed and explained separately. South China is a major block possessing more advantages for regional research than any of the other blocks in China. There exists a well‐developed succession of marine strata from the Ediacaran through to the Triassic with a relatively high resolution of bio‐ and chrono‐stratigraphy and an extensive marine fossil record. Stratigraphic occurrences of 5685 genera and 1386 families within 32 phyla or subphyla plus groups with uncertain affinities from this interval have been compiled by a large team of palaeontologists. With the exception of the Ediacaran, 50 time intervals with an average duration of 6.8 Ma are investigated. Diversity curves constructed at the levels of genus, family and order indicate that marine biodiversity peaked six times within the intervals: (1) Early Cambrian explosive radiation, (2) Early‐Mid Ordovician radiation mainly of the Paleozoic Evolutionary Fauna, (3) Early Silurian radiation, (4) late Early‐Mid Devonian radiation, (5) Mid‐Late Permian radiation and (6) Mid Triassic radiation chiefly of the Modern Evolutionary Fauna. Drops in biodiversity are controlled by various factors: (1) global catastrophes, which produced rapid losses of biodiversity during short time intervals; (2) global environmental perturbations with long term effects, as in the Carboniferous; (3) regional tectonics and palaeogeographical constraints, resulting in a lack of marine sedimentary rocks in many areas with biodiversity declining, as in the Wenlock; (4) unique sedimentary facies in large areas resulting in biodiversity losses, as in the Late Cambrian and (5) artifactual constraints associated with a lack of fossil record or low research intensity for some intervals, as in the period of about 30 Ma following the Early Cambrian explosive radiation. Copyright © 2007 John Wiley & Sons, Ltd.
Patterns of PIK3CA alterations in familial colorectal and endometrial carcinoma
Authors: Ollikainen Miina , Gylling Annette , Puputti Marjut , Nupponen Nina N. , Abdel‐Rahman Wael M. , Butzow Ralf , Peltomäki Päivi 
Published: April 2007

AbstractWhile the phosphatidylinositol 3‐kinase (PI3K)/AKT signaling pathway is known to be activated in multiple sporadic cancers, the role of this pathway in familial tumors is mostly unknown. We searched for alterations in the catalytic domain of PI3K (PIK3CA), PTEN and KRAS, all of which may contribute to PI3K/AKT pathway activation, in a total of 160‐familial colorectal (CRC) and endometrial carcinomas (EC), stratified by the presence vs. absence of germline mutations in DNA mismatch repair (MMR) genes. PIK3CA alterations (consisting of point mutations or low‐level amplification, which were mutually exclusive with 1 exception) occurred in 10/70 (14%) of CRCs and 19/90 (21%) of ECs. Within ECs, amplification was significantly associated with the subgroup lacking germline mutations in MMR genes (familial site‐specific endometrial cancer) (p = 0.015). Decreased or lost PTEN expression was characteristic of endometrial tumourigenesis (51/81, 63%, in EC compared with 24/62, 39%, in CRC, p = 0.004) and KRAS mutations of colorectal tumourigenesis (19/70, 27% in CRC vs. 9/89, 10%, in EC, p = 0.006) regardless of the MMR gene mutation status. PIK3CA alterations frequently coexisted with PTEN or KRAS changes. Combined with published studies on sporadic tumors, our data broaden the understanding of the role for PI3K pathway genes in human tumorigenesis. © 2007 Wiley‐Liss, Inc.
Influence of VEGF‐A gene variation and protein levels in breast cancer susceptibility and severity
Authors: Balasubramanian Sabapathy P. , Cox Angelo , Cross Simon S. , Higham Sue E. , Brown Nicola J. , Reed Malcolm W. 
Published: April 2007

AbstractVascular endothelial growth factor‐A (VEGF‐A) plays an important role in tumour angiogenesis and cancer progression.VEGFgene variation may influence VEGF levels and therefore cancer susceptibility and progression. We studied the role ofVEGFsingle nucleotide polymorphisms and haplotypes in breast cancer susceptibility and severity. We also studied the relationships ofVEGFSNPs with circulating VEGF levels in healthy volunteers and protein expression in breast cancers. Single nucleotide polymorphisms (SNPs) in the regulatory regions of theVEGFgene were genotyped by high throughput methods in ∼500 breast cancer cases and 500 appropriate controls. Haplotype frequencies were inferred using methods based on the Expectation Maximisation algorithm. The effect ofVEGFgenotypes on serum and plasma VEGF levels were studied in another cohort of healthy individuals. A semi‐quantitative assessment of VEGF protein expression on tissue micro arrays (TMA) constructed from ∼300 breast cancer samples was performed and compared withVEGFgenotypes and with histopathological parameters and survival in breast cancer. The −460T/+405C/−7C/936C haplotype in the VEGF gene was found to be associated with decreased breast cancer risk (p= 0.029). The −7C>T polymorphism may influence overall breast cancer survival (p= 0.027). Individual polymorphisms however did not affect breast cancer susceptibility. There was no association between the individual polymorphisms and circulating VEGF levels in healthy volunteers and VEGF expression on the breast cancer micro array. VEGF expression in breast cancers was however associated with high grade (p= 0.002) and ER negative tumours (p= 0.03). © 2007 Wiley‐Liss, Inc.
m‐THPC‐mediated photodynamic therapy of malignant gliomas: Assessment of a new transfection strategy
Authors: Molinari Agnese , Bombelli Cecilia , Mannino Stefano , Stringaro Annarita , Toccacieli Laura , Calcabrini Annarica , Colone Marisa , Mangiola Annunziato , Maira Giulio , Luciani Paola , Mancini Giovanna , Arancia Giuseppe 
Published: April 2007

AbstractMalignant gliomas represent the most common primary brain tumor: more than 50% of them are glioblastoma multiforme (GBM). Photodynamic therapy may offer a very good chance of targeted destruction of infiltrating GBM cells, thus increasing the survival time and recurrence‐free interval of GBM patients. Among photosensitizing agents, meta‐tetrahydroxyphenylchlorin (m‐THPC) is promising for the treatment of brain tumors. In previous studies, we investigated the transfection activity of dimyristoyl‐sn‐glycero‐phosphatidylcholine (DMPC) liposomes, containing a cationic gemini surfactant, loaded with m‐THPC on human colon adenocarcinoma and glioblastoma cell lines. In this paper, the uptake and the intracellular distribution of m‐THPC, loaded in several formulations of cationic liposomes, were analyzed, by making a comparison with those obtained using the same chlorin in the pharmaceutical form (Foscan®). Moreover, by cloning efficiency assay the potential therapeutic efficiency of chlorin delivered by liposome formulations was compared with that of the pharmaceutical compound, before and after irradiation with laser light at 652 nm. The obtained results indicated that cationic liposomes (i) transferred m‐THPC in glioblastoma cells more efficiently than pharmaceutical formulation; (ii) significantly (p < 0.001) increased the m‐THPC cytotoxic effect after laser irradiation; (iii) seemed to exert their cytotoxic action in the early phase of interaction with the cells, during adhesion to the plasma membrane. © 2007 Wiley‐Liss, Inc.
Anxiety affects the relationship between parents and their very low birth weight infants
Authors: Zelkowitz Phyllis , Bardin Claudette , Papageorgiou Apostolos 
Published: April 2007

AbstractThe goal of this study was to examine the medical and sociodemographic factors associated with parental anxiety following the birth of a very low birth weight infant (VLBW, below 1500 g), and to determine the impact of anxiety on the behavior of parents with their VLBW infants in the Neonatal Intensive Care Unit (NICU). The parents of 88 VLBW infants were recruited through the NICU of a tertiary‐care hospital, approximately 2 weeks following delivery. Parents completed self‐report questionnaires measuring anxiety, marital quality, and social support. Prior to discharge, each parent was observed twice during a feeding interaction with the infant. Maternal anxiety was greater when their infants were smaller in terms of birth weight and younger in gestational age. Maternal education, marital status, and country of origin, as well as social support and marital quality, were also associated with anxiety. Paternal anxiety was not related to socioeconomic status or infant medical risk, but was associated with country of origin, social support, and marital quality. For both mothers and fathers, anxiety was a better predictor of parental behavior than was infant medical risk. These findings suggest the need to intervene with anxious parents in order to promote satisfactory parent‐infant relationships.
Qualitative and quantitative characterization of the in vitro dehydration process of hydrogel contact lenses
Authors: González‐Méijome José M. , López‐Alemany Antonio , Almeida José B. , Parafita Manuel A. , Refojo Miguel F. 
Published: April 2007

AbstractPurpose: To investigate the in vitro dehydration process of conventional hydrogel and silicone‐hydrogel contact lens materials. Methods: Eight conventional hydrogel and five silicone‐hydrogel contact lenses were dehydrated under controlled environmental conditions on an analytical balance. Data were taken at 1‐min intervals and dehydration curves of cumulative dehydration (CD), valid dehydration (VD), and dehydration rate (DR) were obtained. Several quantitative descriptors of the dehydration process were obtained by further processing of the information. Results: Duration of phase I (r2 = 0.921), CD at end of phase I (r2 = 0.971), time to achieve a DR of −1%/min (r2 = 0.946) were strongly correlated with equilibrium water content (EWC) of the materials. For each individual sample, the VD at different time intervals can be accurately determined using a 2nd order regression equation (r2 > 0.99 for all samples). The first 5 min of the dehydration process show a relatively uniform average CD of about −1.5%/min. After that, there was a trend towards higher average CD for the following 15 min as the EWC of the material increases (r2 = 0.701). As a consequence, average VD for the first 5 min displayed a negative correlation with EWC (r2 = 0.835), and a trend towards uniformization among CL materials for the following periods (r2 = 0.014). Overall, silicone‐hydrogel materials display a lower dehydration, but this seems to be primarily due to their lower EWC. Conclusions: DR curves under the conditions of the present study can be described as a three‐phase process. Phase I consists of a relatively uniform DR with a duration that ranges from 10 to almost 60 min and is strongly correlated with the EWC of the polymer as it is the CD during this phase. Overall, HEMA‐based hydrogels dehydrate to a greater extent and faster than silicone‐hydrogel materials. There are differences in water retention between lenses of similar water content and thickness that should be further investigated. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Ethylene oxide sterilization in the medical‐supply manufacturing industry: Assessment and control of worker exposure
Authors: Chien Yeh‐Chung , Liu Hung‐Hsin , Lin Yi‐Chang , Su Po‐Chi , Li Lien‐Hsiung , Chang Cheng‐Ping , Tang Da‐Toung , Chen Chang‐Yuh 
Published: April 2007

AbstractObjective: In 2005, the Taiwan Institute of Occupational Safety and Health started an on‐site consulting program for the medical supplies manufacturing industry, which use ethylene oxide (EO) as a sterilant, with the goal of enhancing occupational hygiene practices and controlling EO‐related risks. This study presents EO exposure assessment results and examines the effectiveness of control measures. Methods: Detailed surveys, including exposure monitoring, were conducted at 10 factories. Airborne EO was collected using an HBr‐coated charcoal tube and analyzed using GC/MS. Results: Sterilizer operators had an average short‐term EO exposure level of 27.61 ppm during unloading; mean time‐weighted average workshift exposure was 7.35 ppm. High EO concentrations were also present throughout the facilities. Specifically, mean EO concentrations in the aeration area, near the sterilizer and in the warehouse were 10.19, 5.75, and 8.78 ppm, respectively. These findings indicate that immediate controls are needed, and that EO emissions from sterilized products during storage cannot be overlooked. Worker short‐term exposures during unloading was inversely correlated (p < 0.05) with the numbers of poststerilization purge cycle applied. The specific controls implemented and their usefulness is discussed. Conclusion: Increasing the number of poststerilization purge cycles is a simple approach to eliminating extremely high exposure during unloading. Improvements to ventilation, particularly in the aeration area and warehouse, were also effective in minimizing worker exposures. Use of effective respirator is recommended until the EO exposure levels, averaging 3.41 ppm after the controls, fall below the permissible exposure limit. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Novel technique for preparing Ca‐ and P‐containing ceramic coating on Ti‐6Al‐4V by micro‐arc oxidation
Authors: Yu Sirong , Yang Xizhen , Yang Long , Liu Yaohui , Yu Yingjie 
Published: April 2007

AbstractA novel technique for preparing the Ca‐ and P‐containing ceramic coating on Ti‐6Al‐4V alloy by micro‐arc oxidation (MAO) was developed successfully in this paper. In the new technique, Ti alloy first was micro‐arc oxidated in P‐containing electrolyte, and then it was micro‐arc oxidated in Ca‐containing electrolyte. This technique can avoid the undesired chemical reaction between Ca‐containing salt and P‐containing salt in electrolyte. The surface morphologies, composition, and phases of MAO coatings were studied by means of SEM, EDS, and XRD. The results show that the P‐ and Ca‐containing coating on Ti‐6Al‐4V alloy contains Ti, TiO2 (rutile), α‐Ca(PO3)2, CaTiO3, and AlTi3. There are many small and uniform pores in the coating. Most of these pores are coterminous. The microhardness of the coating is 720 HV and higher than that of Ti‐6Al‐4V alloy (220 HV). The coating is more wear‐resistant than Ti‐6Al‐4V alloy under the lubricant of the artificial saliva and not easy to desquamate from the substrate of Ti‐6Al‐4V alloy. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007