bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modifying electrooptics of orthoconic antiferroelectric liquid crystal cells by manufacturing procedures
Authors: Spadło A. , Bennis N. , Dąbrowski R. , Quintana X. , Otón J. , Geday M. 
Published: December 2006

AbstractOrthoconic antiferroelectric liquid crystals (AFLCs) having 45° tilt angle have been proposed to overcome the problem of reduced contrast usually exhibited by regular antiferroelectric displays. However, the pitch of the helix induced by chirality is customarily short in existing orthoconic materials, making it difficult to achieve surface stabilized configurations when the material’s pitch is smaller than the cell thickness.In this work, the influence of different manufacturing procedures on the electrooptical behaviour of orthoconic AFLCs is studied. Using the same orthoconic AFLC mixture, aligning surfaces and manufacturing protocol, we have observed two dissimilar responses, true orthoconic behaviour, and orthoconic V-shape response. The electrooptical response depends ultimately on the rubbing strategy adopted in either case.
Atom Probe Tomography II. The Precipitation in Al Base Alloys
Authors: De Geuser F. , Lefebvre W. , Auger P. , Danoix F. , Bigot A. , Blavette D. 
Published: December 2006

AbstractThis paper presents two illustrations of the study of phase separation in Al‐based alloys by means of tomographic atom probe. In an AlMgSi alloy, calculations of pair correlation functions have revealed that the nature of solute short range order differs from a pre‐aged specimen to a non‐pre‐aged specimen. This results in different responses to aged hardening treatments. Concerning Al3(Zr,Sc)‐type dispersoids observed in another Al‐based alloy, they are found to display a core‐shell structure wherein Zr is mainly present in the dispersoids periphery. This duplex structure is likely to explain the relative stability of Al3(Zr,Sc) dispersoids.
Kinetic Monte Carlo Simulations of Precipitation
Authors: Clouet E. , Hin C. , Gendt D. , Nastar M. , Soisson F. 
Published: December 2006

AbstractWe present some recent applications of the atomistic diffusion model and of the kinetic Monte Carlo (KMC) algorithm to systems of industrial interest, i.e. Al‐Zr‐Sc and Fe‐Nb‐C alloys, or to model systems. These applications include study of homogeneous and heterogeneous precipitation as well as of phase transformation under irradiation. The KMC simulations are also used to test the main assumptions and limitations of more simple models and classical theories used in the industry, e.g. the classical nucleation theory.
Atom Probe Tomography I. Early Stages of Precipitation of NbC and NbN in Ferritic Steels
Authors: Danoix F. , Bémont E. , Maugis P. , Blavette D. 
Published: December 2006

AbstractThe results reported in this paper give new information regarding the early stages of precipitation in model low niobium steels. It clearly appears that the kinetic paths for carbides and nitrides precipitation in the investigated model alloys are very different, more continuous in the case of carbides, and through GP zones formation in the case of nitrides.
Platelet‐derived growth factor C plays a role in the branchial arch malformations induced by retinoic acid
Authors: Han Jing , Li Li , Zhang Zhaofeng , Xiao Ying , Lin Jiuxiang , Zheng Liping , Li Yong 
Published: December 2006

AbstractBACKGROUND: All‐trans‐retinoic acid (RA) can produce branchial arch abnormalities in postimplantation rodent embryos cultured in vitro. Platelet‐derived growth factor C (PDGF‐C) was recently identified as a member of the PDGF ligand family. Many members of the PDGF family are essential for branchial arch morphogenesis and can be regulated by RA. The roles of PDGF‐C in branchial arch malformations induced by RA and possible mechanisms were investigated. METHODS: In whole embryo culture (WEC), mouse embryos were exposed to RA at 0, 0.1, 0.4, 1.0, or 10.0 μM, PDGF‐C at 25, 50, or 75 ng/mL, or PDGF‐C at 25, 50, or 75 ng/mL containing 0.4 μM RA. After 48 h of culture, mouse embryos were examined for dysmorphogenesis, and whole‐mount immunohistochemistry was applied to PDGF‐C. In explant cultures, explants were exposed to the same doses of RA and PDGF‐C as WEC. Semiquantitative RT‐PCR, zymography, and reverse zymography were used to evaluate the expressions and activities of matrix metalloproteinase (MMP)‐2, MMP‐14, and tissue inhibitor of metalloproteinase (TIMP)‐2. RESULTS: PDGF‐C was reduced by RA, and exogenous PDGF‐C rescued the branchial arch malformations induced by RA. Moreover, PDGF‐C prevented RA‐induced inhibition of the migratory ability of mesenchymal cells in the first branchial arch, by regulating the expressions of MMP‐2, MMP‐14, and TIPM‐2. CONCLUSIONS: Our results suggest that RA exposure reduces the expression of PDGF‐C. The branchial arch malformations resulting from fetal RA exposure are caused at least partially by loss of PDGF‐C and subsequent misregulations of the expressions of MMP‐2, MMP‐14, and TIMP‐2. Birth Defects Research (Part A), 2007. © 2006 Wiley‐Liss, Inc.
Patterns of severe abdominal wall defects: Insights into pathogenesis, delineation, and nomenclature
Authors: Vauthay Liliana , Mazzitelli Nancy , Rittler Monica 
Published: December 2006

AbstractBACKGROUND: During the last decade, descriptions of malformation complexes involving an abdominal wall defect (AWD) have repeatedly appeared in the literature, and there has been frequent confusion regarding nomenclature, definitions, and delineations. The aims of this work were to evaluate possible embryological relationships among AWD cases, review the related nomenclature, identify patterns involving AWDs, and stress the importance of complete clinical descriptions. METHODS Cases diagnosed as AWD complexes were selected from live‐ and stillborn infants of the Hospital Materno Infantil ${\rm Ram\acute{\sigma}n}$ Sardá, Buenos Aires, and from the Laboratory of Perinatal Pathology, Buenos Aires, Argentina. They were sorted by the location of the AWD, the umbilical cord length, and the presence or absence of a persistent cloaca. The findings in 26 cases were described, according to proposed definitions. RESULTS: Three patterns could be identified: 1) the AWD involving the umbilical ring, a persistent or exstrophic cloaca, and a spinal cord anomaly; 2) the AWD extending laterally to the umbilical ring, severe unilateral limb defects, and same‐sided agenesis of abdominal organs; and 3) the AWD not involving the umbilical ring, clefts, exencephaly, and amputations. Furthermore, overlapping among these patterns was observed, and possible involved mechanisms are discussed. CONCLUSIONS: The observed overlapping among patterns suggested that malformation complexes involving AWDs might not be independent conditions but rather belong to a common and broader spectrum of anomalies. Complete clinical descriptions, the avoidance of synonyms and generalizations, and strictly defined inclusion criteria are proposed for a better understanding of pathogenetic pathways in, and relationships among, AWD complexes. Birth Defects Research (Part A), 2007. © 2006 Wiley‐Liss, Inc.
Formation of Fibril Structures in Polymerizable, Rod–Coil‐Oligomer‐Modified Epoxy Networks
Authors: Yu Yingfeng , Gao Zongyong , Zhan Guozhu , Li Liang , Li Shanjun , Gan Wenjun , Crivello James V. 
Published: December 2006

AbstractThis paper describes the in situ preparation of fibrils in epoxy networks in which the fibril‐like structures are cured polymerizable rod–coil oligomers. The epoxy‐terminated α,ω‐modified PEO oligomers, which are ABA rod–coil–rod oligomers with a poly(ethylene oxide) coil unit and two aromatic azomethine liquid‐crystalline rod units, were synthesized and then further blended with an epoxy precursor. Uniform nanoscale columnar structures were observed in the neat rod–coil oligomers as well as in the crosslinked liquid‐crystalline state. During the curing of the blends, the supramolecular nanoscale columnar structures of the rod–coil oligomers are transformed into polymeric fibrils where the epoxy functional end groups have co‐reacted with epoxy precursors to form a crosslinked network.
On the Nature of DNA‐Duplex Stability
Authors: Řezáč Jan , Hobza Pavel 
Published: December 2006

AbstractThe unwinding free energy of 128 DNA octamers was correlated with the sum of interaction energies among DNA bases and their solvation energies. The former energies were determined by using the recently developed density functional theory procedure augmented by London dispersion energy (RI‐DFT‐D) that provides accurate hydrogen‐bonding and stacking energies highly comparable with CCSD(T)/complete basis set limit benchmark data. Efficient tight‐binding DFT covering dispersion energy was also used and yielded satisfactory results. The latter method can be used for extended systems. The solvation energy was determined by using a C‐PCM continuum solvent at HF level calculations. Various models were adopted to correlate theoretical energies with experimental unwinding free energies. Unless all energy components (hydrogen‐bonding, intra‐ and interstrand‐stacking, and solvation energies) were included and weighted individually, no satisfactory correlation resulted. The most advanced model yielded very close correlation (RMSE=0.32 kcal mol−1) fully comparable with the entirely empirical correlation introduced in the original paper.3 Analysis of the theoretical results shows the importance of inter‐ and intramolecular stacking energies, and especially the latter term plays a key role in determining DNA‐duplex stabilization.
One‐Step Synthesis of Large‐Aspect‐Ratio Single‐Crystalline Gold Nanorods by Using CTPAB and CTBAB Surfactants
Authors: Kou Xiaoshan , Zhang Shuzhuo , Tsung Chia‐Kuang , Yang Zhi , Yeung Man Hau , Stucky Galen D. , Sun Lingdong , Wang Jianfang , Yan Chunhua 
Published: December 2006

AbstractGold nanorods were prepared in high yields by using a one‐step seed‐mediated process in aqueous cetyltripropylammonium bromide (CTPAB) and cetyltributylammonium bromide (CTBAB) solutions in the presence of silver nitrate. The diameters of the nanorods range from 3 to 11 nm, their lengths are in the range of 15 to 350 nm, and their aspect ratios are in the range of 2 to 70. The diameters of the Au nanorods obtained from one growth batch in CTPAB solutions decrease as their lengths increase, and their volumes decrease as the aspect ratios increase. The diameters of the Au nanorods obtained from one growth batch in CTBAB solutions first decrease and then slightly increase as their lengths increase, and their volumes increase as the aspect ratios increase. These Au nanorods are single‐crystalline and are seen to be oriented in either the [100] or [110] direction under transmission electron microscopy imaging, irrespective of their sizes. To the best of our knowledge, this is the first report of the preparation by using wet‐chemistry methods of single‐crystalline Au nanorods with aspect ratios larger than 15.
Reversible Immobilization and Direct Electron Transfer of Cytochrome c on a pH‐Sensitive Polymer Interface
Authors: Zhou Jianhua , Lu Xianbo , Hu Jianqiang , Li Jinghong 
Published: December 2006

AbstractA pH‐sensitive polymer interface has been used as a matrix for reversible immobilization of cytochrome c (Cyt c) on an Au surface through a dip‐coating process. The pH‐sensitive behavior of the polymer brush interface has been demonstrated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The reversible immobilization and electron‐transfer properties of Cyt c have been investigated by in situ UV/Vis spectrophotometry and CV. The results have shown that the poly(acrylic acid) (PAA) brush acted as an excellent adsorption matrix and a good accelerant for the direct electron transfer of Cyt c, which gave redox peaks with a formal potential of 40 mV versus Ag/AgCl in pH 7.6 phosphate buffer solution. The average surface coverage of Cyt c on the PAA film was about 1.7×10−10 mol cm−2, indicating a multilayer of Cyt c. The electron‐transfer rate constant was calculated to be around 0.19 s−1 according to the CV experiments. The interface was subjected to in situ attenuated total internal reflection Fourier‐transform infrared (ATR‐FTIR) spectroscopic analysis, in order to further confirm the immobilization of Cyt c on the surface. This polymer–protein system may have potential applications in the design of biosensors, protein separation, interfacial engineering, biomimetics, and so on.
Tuning the Excited‐State Energy of the Organic Chromophore in Bichromophoric Systems Based on the RuII Complexes of Tridentate Ligands
Authors: Medlycott Elaine A. , Hanan Garry S. , Loiseau Frédérique , Campagna Sebastiano 
Published: December 2006

AbstractA series of new heteroleptic and homoleptic RuII complexes containing variously substituted bis(pyridyl)triazine ligands has been prepared and their absorption spectra, redox behaviour and luminescence properties (both in fluid solution at room temperature and in a rigid matrix at 77 K) have been investigated. For some compounds, X‐ray structures have also been determined. The new bis(pyridyl)triazines incorporate additional chromophores, such as biphenyl, phenanthrene, anthracene and bromoanthracene derivatives, so the RuII species can be considered as multichromophoric species. The absorption spectra and redox properties of all the metal complexes have been assigned to features belonging to specific subunits, thus suggesting that these species can be regarded as multicomponent, supramolecular assemblies from an electronic coupling point of view. Whereas most of the complexes exhibit luminescence properties that can be attributed to metal‐to‐ligand charge‐transfer (MLCT) states involving the metal‐based subunit(s), the species containing the anthryl and, even more, the brominated anthryl chromophores exhibit complicated luminescence behaviour. For example, 2 d (the anthryl‐containing heteroleptic metal compound) exhibits MLCT emission at room temperature and emission from the anthracene triplet at 77 K; 2 e (the bromo‐substituted anthryl‐containing heteroleptic metal compound) exhibits anthryl‐based emission at 77 K and MLCT emission at room temperature, but with a prolonged lifetime, thus suggesting equilibration between two triplet states that belong to different chromophores. The equilibration regime between MLCT and aromatic hydrocarbon triplet states is therefore reached by suitable substitution on the organic chromophore.
Amphiphilic NO‐Donor Antioxidants
Authors: Chegaev Konstantin , Lazzarato Loretta , Rolando Barbara , Marini Elisabetta , Lopez Gloria V. , Bertinaria Massimo , Di Stilo Antonella , Fruttero Roberta , Gasco Alberto 
Published: December 2006

AbstractModels of amphiphilic NO‐donor antioxidants 24–26 were designed and synthesized. The products were obtained by linking a lipophilic tail (C6, C8, C10) with a polar head constituted by the 2,6‐dimethoxyphenol antioxidant joined to the NO‐donor 3‐furoxancarboxamide substructure through a bridge containing a quaternary ammonium group. Compound 23, containing the shortest C2‐alkyl chain, was also studied as a reference. The antioxidant properties (TBARS and LDL oxidation assays) and the vasodilator properties of the compounds were studied in vitro. The ability of these products to interact with phospholipid vesicles was also investigated by NMR techniques. The results indicate that both activities are modulated by the ability of the compounds to accumulate on phospholipid layers.
Identical epidermal growth factor receptor mutations in adenocarcinomatous and squamous cell carcinomatous components of adenosquamous carcinoma of the lung
Authors: Kang Shin Myung , Kang Hyun Ju , Shin Ju Hye , Kim Hoguen , Shin Dong Hwan , Kim Se Kyu , Kim Joo‐Hang , Chung Kyung Young , Kim Sung Kyu , Chang Joon 
Published: December 2006

AbstractBACKGROUND.Adenosquamous carcinoma of the lung is composed of adenocarcinomatous and squamous cell carcinomatous components. The epidermal growth factor receptor (EGFR) mutations occur mostly in adenocarcinomas and rarely in squamous cell carcinoma of lung. Attempts to investigate the EGFR mutation status in each component of adenosquamous carcinoma and to characterize the patients according to mutation status may help to understand the histogenesis of adenosquamous carcinoma.METHODS.The mutation status of EGFR kinase domain from exon 18 to 21 was investigated in 25 Korean patients with adenosquamous carcinoma by polymerase chain reaction–single strand conformation polymorphism using the tissues of each component from the adenosquamous carcinoma tumor. Clinicopathologic characteristics of the patients according to the status of EGFR mutations were compared.RESULTS.EGFR mutations were identified in 11 (44%) patients: 9 mutations were in exon 19, 1 in exon 20, and 1 in exon 21. EGFR mutations were significantly more frequent (P = .005) in women (n = 8, 80%) than men (n = 3, 20%). Never‐smokers (n = 8, 62%) had EGFR mutations more commonly than smokers (n = 3, 25%; P = .111). Identical EGFR mutations in both components of adenosquamous carcinoma were confirmed by nucleotide sequencing.CONCLUSIONS.The frequency of EGFR mutation and clinicopathologic characteristics of the EGFR mutants in adenosquamous carcinoma are similar to those of Asian patients with adenocarcinomas. Identical EGFR mutations in both components suggest the possibility of monoclonality in the histogenesis of adenosquamous carcinoma. Cancer 2007;109:581–587. © 2006 American Cancer Society.
Cumulative cost pattern comparison of prostate cancer treatments
Authors: Wilson Leslie S. , Tesoro Ross , Elkin Eric P. , Sadetsky Natalia , Broering Jeanette M. , Latini David M. , DuChane Janeen , Mody Reema R. , Carroll Peter R. 
Published: December 2006

AbstractBACKGROUND.Studies that compare prostate cancer treatment costs show wide variation. None compare all contemporary treatment costs, and most focus on initial treatment costs. The authors compared healthcare utilization and cost patterns of prostate cancer treatments over a span of 5.5 years in 4553 newly diagnosed patients stratified by age and risk group.METHODS.Contemporary treatment and evaluation patterns for prostate cancer were identified by using CaPSURE, a national disease registry of men with prostate cancer that included ongoing clinical data collection from 31 academic and community urology practices and biennial patient‐reported outcome questionnaires that included demography, medical condition, comorbidity, risk measures, and healthcare utilization. Costs of outpatient visits, medications, and hospitalizations were applied from various national sources. Recurrent events analysis (MCF) accounted for left and right censorship. A mixed effects regression model with bootstrapping for skewed cost data quantified the relation between MCF cost, age, and risk.RESULTS.Prostate‐related costs in the first 6 months after treatment were $11,495, (from $2586 for watchful waiting (WW) to $24,204 for external beam radiation. After 6 months, average cost was only $3044. Annual cost is $7740, highest for androgen deprivation therapy ($12,590) and lowest for watch waiting ($5843). Risk and age were significantly related to initial treatment choice. Cumulative cost ($42,570) allowed a better estimate of treatment pattern costs.CONCLUSIONS.The cost burden of prostate cancer is high, but it varies by treatment type even when controlling for disease, age, and stage. Cumulative cost analysis allowed inclusion of adverse events and disease recurrence costs, making new cost comparisons evident among treatments. Cancer 2007;109:518–527. © 2006 American Cancer Society.
Underestimation of malignancy of breast core‐needle biopsy
Authors: Houssami Nehmat , Ciatto Stefano , Ellis Ian , Ambrogetti Daniela 
Published: December 2006

AbstractBACKGROUND:A review of the literature indicated variable underestimation rates for breast core‐needle biopsy (CNB) based on generally small series. In this article, the authors present precise estimates for overall underestimation and for categories of histologic underestimates (including categories that reflect contemporary classification) and examine the effect of lesion and sampling variables.METHODS:Among 4035 consecutive CNBs, the authors examined women whose CNB outcome represented a potential underestimate of malignancy (benign but of uncertain biologic or malignant potential or B3 and ductal carcinoma in situ [DCIS]). From 889 eligible women, all 758 women who had excision histology available were included.RESULTS:Overall underestimation of CNB was 27.7% (95% confidence interval [95% CI], 24.5–30.9%). The following category‐specific rates were used: B3 underestimates, 36.2% (95% CI, 30.6–41.8%); B3 underestimates (excluding atypical proliferations), 17.9% (95% CI, 10.8–24.9%); atypical ductal hyperplasia underestimates, 29.0% (95% CI, 21.4–36.6%; upgraded to DCIS) and 44.2% (95% CI, 36.0–52.5%; upgraded to DCIS or invasive cancer); and DCIS underestimates, 22.8% (95% CI, 19.0–26.5%). There was a significant trend toward greater underestimation of malignancy with increasing lesion size on imaging studies for overall underestimates (P = .00008), B3 underestimates (P = .009), and DCIS underestimates (P = .0007). Underestimation rates did not differ between masses (27.9%) and microcalcifications (27.6%; chi‐square statistic with 1 degree of freedom = 3.02; P = .98) and were significantly lower for vacuum‐assisted CNB (11‐gauge) than for automated CNB (14‐gauge; P = .001). Underestimation rates, when sampling microcalcifications, decreased with increasing number of cores collected, but this was mainly for DCIS underestimates.CONCLUSIONS:CNB results that were not definitely negative or were not positive for invasive cancer were associated with high rates of underestimation of disease and with target lesion size. Identifying imaging or sampling factors that affect underestimation rates of CNB may assist in reducing their occurrence and better predicting excision histology outcomes. Cancer 2007;109:496–501. © 2006 American Cancer Society.
Reaction Pathways Involved in the Mechanism of AlIII Chelation with Caffeic Acid: Catechol and Carboxylic Functions Competition
Authors: Lapouge Christine , Cornard Jean‐Paul 
Published: December 2006

AbstractDensity functional theory calculations on the AlIII–caffeic acid system are carried out to investigate the fixing mechanism of this metal ion to the two competing complexing sites in the ligand. This theoretical study was performed to explain the complex formation of 1:1 stoichiometry observed in aqueous medium at low pH values. Both complexation with the catechol and carboxylic functions are envisaged. The reaction pathways for the formation of these two chelates are calculated at the B3LYP/6‐31G** level of theory. The complexation on the more acidic group is relatively straightforward and shows the intermediate formation of a monodentate complex followed by a chelation process. The complexation reaction pathway with the catechol function is more sophisticated, and several pathways are explored. Once more, the formation of a monodentate complex is achieved and the most favorable pathway for chelation involves the successive steps: 1) coordination of AlIII on the oxygen atom of a hydroxyl group, 2) deprotonation of this hydroxyl group, 3) ring closure with the other oxygen atom, and 4) deprotonation of the second hydroxyl. From an energetic point of view, this second pathway is more favorable. Notably the energy barrier necessary to form the chelate is lower for the catechol function than that calculated for the carboxylic group. The results of this purely theoretical study are in complete agreement with spectroscopic investigations performed on this system.