bluuebunny/crossref_metadata_2025_split huggingface dataset:
A candidate precursor to serous carcinoma that originates in the distal fallopian tube
Authors: Lee Y , Miron A , Drapkin R , Nucci MR , Medeiros F , Saleemuddin A , Garber J , Birch C , Mou H , Gordon RW , Cramer DW , McKeon FD , Crum CP 
Published: November 2006

AbstractThe tubal fimbria is a common site of origin for early (tubal intraepithelial carcinoma or TIC) serous carcinomas in women with familial BRCA1 or 2 mutations (BRCA+). Somatic p53 tumour suppressor gene mutations in these tumours suggest a pathogenesis involving DNA damage, p53 mutation, and progressive loss of cell cycle control. We recently identified foci of strong p53 immunostaining—termed ‘p53 signatures’—in benign tubal mucosa from BRCA+ women. To examine the relationship between p53 signatures and TIC, we compared location (fimbria vs ampulla), cell type (ciliated vs secretory), evidence of DNA damage, and p53 mutation status between the two entities. p53 signatures were equally common in non‐neoplastic tubes from BRCA+ women and controls, but more frequently present (53%) and multifocal (67%) in fallopian tubes also containing TIC. Like prior studies of TIC, p53 signatures predominated in the fimbriae (80–100%) and targeted secretory cells (HMFG2 + /p73−), with evidence of DNA damage by co‐localization of γ‐H2AX. Laser‐capture microdissected and polymerase chain reaction‐amplified DNA revealed reproducible p53 mutations in eight of 14 fully‐analysed p53 signatures and all of the 12 TICs; TICs and their associated ovarian carcinomas shared identical mutations. In one case, a contiguous p53 signature and TIC shared the same mutation. Morphological intermediates between the two, with p53 mutations and moderate proliferative activity, were also seen. This is the first report of an early and distinct alteration in non‐neoplastic upper genital tract mucosa that fulfils many requirements for a precursor to pelvic serous cancer. The p53 signature and its malignant counterpart (TIC) underline the significance of the fimbria, both as a candidate site for serous carcinogenesis and as a target for future research on the early detection and prevention of this disease. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Quantitative structure‐activity relationship study of bitter di‐ and tri‐peptides including relationship with angiotensin I‐converting enzyme inhibitory activity
Authors: Wu Jianping , Aluko Rotimi E. 
Published: November 2006

AbstractBitterness represents a major challenge in industrial application of food protein hydrolysates or bioactive peptides and is a major factor that controls the flavor of formulated therapeutic products. The aim of this work was to apply quantitative structure‐activity relationship modeling as a tool to determine the type and position of amino acids that contribute to bitterness of di‐ and tri‐peptides. Datasets of bitter di‐ and tri‐peptides were constructed using values from available literature, followed by modeling using partial least square (PLS) regression based on the three z‐scores of 20 coded amino acids. Prediction models were validated using cross‐validation and permutation tests. Results showed that a single‐component model could explain 52 and 50% of the Y variance (bitterness threshold) of bitter di‐ and tri‐peptides, respectively. Using PLS regression coefficients, it was determined that hydrophobic amino acids at the carboxyl‐terminus and bulky amino acid residues adjacent to the carboxyl terminal are the major determinants of the intensity of bitterness of di‐ and tri‐peptides. However, there was no significant (p > 0.05) correlation between bitterness of di‐ and tri‐peptides and their angiotensin I‐converting enzyme‐inhibitory properties. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Optical spectroscopy properties of Tm ion in La3Ga5SiO14 single crystal
Authors: Wang Zengmei , Yin Yansheng , Yuan Duorong 
Published: November 2006

AbstractHigh optical quality La3Ga5SiO14 (abbreviated as LGS):Tm single crystals with dopant concentrations of 1 at% Tm3+ ions were grown by the Czochralski method. The absorption spectrum and fluorescence spectrum of LGS:Tm crystals were measured at room temperature. Based on Judd–Ofelt method, the spectroscopic parameters were obtained, such as intensity parameters Ωt (t = 2, 4, 6), the experimental and theoretical oscillator strength, spontaneous emission probabilities, the radiative lifetime, and the fluorescence branching ratios. The calculated results showed that LGS:Tm is a potential solid‐state laser crystal and has probably realized the 1721 nm and 786 nm laser emission. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ neutron reflectometry probing competitive swelling and de‐swelling of thin polystyrene films
Authors: Müller‐Buschbaum P. , Bauer E. , Maurer E. , Nelson A. , Cubitt R. 
Published: November 2006

AbstractThe competitive penetration of toluene with respect to oxygen, nitrogen and carbon dioxide into a thin and initially dry film of deuterated polystyrene (dPS) is compared to the reverse process of de‐swelling. In‐situ neutron reflectometry is used to follow the swelling and de‐swelling kinetics, allowing the determination of the total dPS thickness, roughness and solvent penetration. Swelling cannot be described in terms of case II diffusion due to the small film thickness and undersaturation results in a small swelling rate of 0.03 nm s–1. De‐swelling is slower by more than two orders in magnitude, thereby underlining the difficulty to remove once incorporated solvent molecules. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)magnified image
Density of electron states in crystalline systems calculated in the presence and absence of the magnetic field
Authors: Olszewski S. , Roliński T. 
Published: November 2006

AbstractIt is demonstrated in terms of explicit calculations that the average density of states in a crystalline system remains unaffected by the presence of the external magnetic field. This is so on condition the magnetic field is weak enough to provide us with a large number of the Landau levels per energy unit. For a special case of a two‐dimensional crystalline system, the equivalence of the density of states obtained in the presence and the absence of the magnetic field can be shown in an analytic way. For three dimensions, the tightly bound s‐electron states in crystals having cubic symmetry are taken into consideration. Here the density of states calculated in the presence of the magnetic field is compared numerically with that of the field‐absent Bloch states acquired with the aid of Jelitto's method. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Extraordinary superatom containing double shell nucleus: Li(HF)3Li connected mainly by intermolecular interactions
Authors: Sun Xiao‐Ying , Li Zhi‐Ru , Wu Di , Sun Chia‐Chung 
Published: November 2006

AbstractThe structure and properties of the Li(HF)3Li cluster with C3hsymmetry are investigated using ab initio calculations. This Li(HF)3Li is a metal–nonmetal–metal sandwich‐like cluster connected mainly by the intermolecular interactions. In the special cluster, the (HF)3containing the triangular F ring with the negative charges is sandwiched between two Li atom. It is interesting that under the action of the triangular F ring with the negative charges, the valence electrons of two Li atoms are pushed out to form the distended excess electron cloud that surrounds the Li(HF)3Li as a core. So the Li(HF)3Li cluster shows not only the electride characteristic, but new superatom characteristics as well. Several characteristics of the special superatom are found. First, the superatom contains the double shell nucleus. The internal nucleus is the regular triangular ring made of three F atoms with the negative charge and the outer‐shell nucleus is made up of three H and two Li atoms with the positive charge. Second, the bonding force of this superatom framework is mainly the intermolecular interaction force, the lithium bond, which is different from that (covalent bond or ionic bond) of the general superatom. Third, the interaction between the outer‐shell nucleus and the excess electron cloud is mainly the anti‐excess‐electron hydrogen bond. Fourth, the special superatom exhibits the new aromaticity (NICS = −8.37 ppm at the center of the regular triangular F ring), which is the aromaticity found in the cluster of the intermolecular interaction. This is the new knowledge of the aromaticity. Fifth, the large polarizability of the superatom is revealed. Further, the vertical ionization energy (VIE) of the superatom is low, 4.51 eV (<5.210 eV of the alkaline–earth metal Ba) so that it may be viewed as a superalkaline–earth metal atom. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Analysis of phosphorylation sites on focal adhesion kinase using nanospray liquid chromatography/multiple reaction monitoring mass spectrometry
Authors: Ciccimaro Eugene , Hevko John , Blair Ian A. 
Published: November 2006

AbstractAn approach based on nanospray liquid chromatography/multiple reaction monitoring mass spectrometry (LC/MRM‐MS) was developed in order to analyze twenty‐nine phosphorylated and non‐phosphorylated tryptic peptides from focal adhesion kinase (FAK). All peptides monitored were resolved and showed excellent peak shape with the exception of one doubly phosphorylated peptide. Optimization of the LC method enabled the identification and subsequent monitoring of six important tyrosine phosphorylation sites on FAK, including phosphorylated Y397 (pY397), pY407, pY576, pY577, pY861, and pY925. This technique was able to identify sites of phosphorylation on FAK as well as qualitatively differentiate between autocatalytic and Src‐induced phosphorylation events. FAK was shown to have autocatalytic function, which resulted in efficient phosphorylation of Y397. FAK was also capable of autophosphorylation on residues Y407 and Y576, though apparently less effectively than autophosphorylation at Y397. Src was found to phosphorylate FAK at Y407, Y576, Y577, and Y861. The presence of Src increased the abundance of pY576 at low temperature indicating Src had particularly high kinase activity toward this residue. Furthermore, Src phosphorylated FAK at Y577 to produce FAK bis‐phosphorylated at Y576 and Y577. In addition, six novel sites of phosphorylation (Y148, Y347, Y441, T503, S850, and Y1007) were identified on FAK. Interestingly, Src phosphorylated FAK to form a peptide uniquely phosphorylated on Y407, together with substantial amounts of the bis‐phosphorylated pY397pY407 peptide. These findings will impact significantly on future studies of FAK activity since pY397 is often used as a measure of FAK activity and Src association. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of N‐terminal modification for recombinant monoclonal antibody light chain using partial reduction and quadrupole time‐of‐flight mass spectrometry
Authors: Yu Lei , Remmele Richard L. , He Bing 
Published: November 2006

AbstractSince most recombinant monoclonal antibodies (mAbs) contain glutamic acid or glutamate at their N‐terminus, cyclization of these residues to form pyroglutamate is an important degradation pathway that often occurs in therapeutic mAb development. In this work, a rapid method was developed to determine pyroglutamate at the N‐terminus of mAb light chain by liquid chromatography coupled with electrospray ionization on a quadrupole time‐of‐flight mass spectrometer (QTOF). High levels of pyroglutamate were found at the N‐terminus of the light chain of a typical recombinant mAb. The quantitative results were comparable to those obtained with a more conventional peptide mapping method. The direct method outlined here can be used to evaluate the impact of N‐terminal cyclization during the processing of recombinant mAbs. Copyright © 2006 John Wiley & Sons, Ltd.
Graviresponses in fungi and slime molds
Authors: Hock Bertold , Häder Donat‐P. 
Published: November 2006

AbstractThe analysis of gravisensing in fungi has not yet proceeded as far as in other systems, such as sensory cells for maintenance of equilibrium in crustaceans and vertebrates, Chara rhizoids or plant roots with regard to positive gravitropism. However, considerable progress has recently been made with several fungal systems in the field of graviresponses. This particularly holds true for the molecular basis of primary events. In this review three systems of increasing complexity are considered: the slime molds Physarum and Dictyostelium, which exhibit gravitaxis, the negative gravitropic sporangium of the zygomycete Phycomyces as a single cell structure with the fastest graviresponses known so far, and the fruit bodies of the basidiomycetes Coprinus and Flammulina as highly complex structures with the ability to generate positional information and cell signalling in the context of negative gravitropism.
Multiple Z‐Plasty in Pilonidal Sinus—A New Technique under Local Anesthesia
Authors: Sharma Pradeep Purushottam 
Published: November 2006

AbstractBackgroundPilonidal sinus is a common surgical condition. Though benign, it causes a lot of distress with its associated morbidity and financial loss to the patient. Many procedures have been tried, ranging from nonsurgical to surgical methods (both conservative and radical ones). It is well known that recurrences are low when the scar is away from the midline.Materials and MethodsThe author has described a new technique of multiple Z‐plasty for the treatment of pilonidal sinus that has been effective in the cure of this problem. This article reports a prospective, nonrandomized noncomparative preliminary clinical study of 115 cases of pilonidal sinus operated on by the author over 14 years.ResultsThe results were compared with the results of other methods mentioned in the literature. There were only two recurrences.ConclusionsThe author proposes that multiple Z‐plasty can be considered as an option in the surgical treatment of pilonidal sinus.
Environmental influences on the spatial distribution of European hake (Merluccius merluccius) and red mullet (Mullus barbatus) in the Mediterranean
Authors: Maravelias Christos D. , Tsitsika Efthymia V. , Papaconstantinou Costas 
Published: November 2006

AbstractGeneralised additive models (GAMs) were used to test the hypotheses that red mullet (Mullus barbatus) and hake (Merluccius merluccius) abundances are related to the bathymetry, spatial location and the temperature‐based variability of the NE Mediterranean. Data were collected during a 2‐year period (1996–1997) of quasi‐synoptic sampling using demersal trawl surveys in the northern Aegean Sea. The results of this study supported these hypotheses. It was found that geographic position and sea bottom characteristics influence the temporal distribution patterns of red mullet and hake. Data are presented that reveal species‐specific aggregation patterns and an important habitat utilisation of the area. The modelled species’ abundances showed a strongly non‐linear dependence on the explanatory covariates. This study, although not directly dealing with spawning, also provided evidence that red mullet and hake demonstrate environmental and bathymetric preferences in the months posterior to spawning. Mean red mullet abundance was consistently highest in areas with warmer bottom waters in the east and west than in the centre, these areas having shallower depths (35–60 m) and bottom temperatures around 19°C. The red mullet appeared to avoid the cold bottom waters (<16°C) of the deeper regions. Results indicated that areas with the highest hake abundances were located in waters of ∼160 m having bottom temperature of ∼16°C and avoided the shallower waters (<70 m) regardless of their bottom temperature. The present findings also suggested that colder bottom waters at all depths were associated with lower‐than‐average hake abundance. Red mullet and hake preferences for areas with specific bathymetric and ocean environmental conditions are believed to be linked to the oceanography of the NE Mediterranean ecosystem.
Sugar fatty acid ester surfactants: Base‐catalyzed hydrolysis
Authors: Baker Irene J. A. , Furlong D. Neil , Grieser Franz , Drummond Calum J. 
Published: November 2006

AbstractRate constants for the base‐catalyzed hydrolysis of sucrose laurate, sucrose α‐sulfonyl laurate, and sucrose α‐ethyl laurate were measured at several temperatures in pH 11 buffer. Activation energies and Arrhenius factors for the hydrolysis reactions were determined. At 27°C, sucrose laurate hydrolyzed fastest and sucrose α‐ethyl laurate slowest. Activation energies and Arrhenius factors showed that both steric and electronic factors affect the rates of ester hydrolysis. Other work has shown that bacterial hydrolysis of sugar fatty acid esters is inhibited in the presence of either α‐sulfonyl or α‐alkyl groups. A kinetic study of base‐catalyzed ester hydrolysis has revealed reasons for the inhibition of bacterial hydrolysis and provided information regarding ester stability at elevated pH.
Synthesis, characterization, and surface properties of new bis‐quaternary pyrimidinium surfactants
Authors: Pegiadou‐Koemtzopoulou S. , Papazoglou V. , Kehayoglou A. H. 
Published: November 2006

AbstractNew bis‐quaternary pyrimidinium surfactants were synthesized by reacting 4‐amino‐5‐phenyl‐pyrimidine with alkylene dibromides (C8−C12). Structural assignments of the new compounds were made on the basis of elemental analysis, infrared, and 1H nuclear magnetic resonance spectroscopy. Critical micelle concentrations, as determined by tensiometry, were lower than those of previously studied corresponding monoquats. The rate of drop coalescence in an oil (hepatane)/water emulsion of a bis‐quat was lower than that of the corresponding monoquat, showing a higher emulsification efficiency for the former.
Composition of mixed anionic/nonionic surfactant micelles
Authors: Akbaş Halide , Işcan Mehmet , Sidim Taliha 
Published: November 2006

AbstractA proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium dodecyl sulfate‐polyoxyethylene 23 lauryl ether (Brij 35) in water and in 0.1 M sodium chloride solution at 25°C. This technique applies the Gibbs‐Duhem equation to the mixed micelle, which is treated as a pseudophase. This proposed methodology which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer‐micelle equilibrium is found to be very similar to the much‐used regular solution for nonideal systems.
Chemical structure/property relationships in surfactants. 17. N‐substituted‐N‐acyl glycinates in pure and synthetic hard river water
Authors: Zhu Yun‐Peng , Rosen Milton J. , Morrall Stephen W. 
Published: November 2006

AbstractThe surface properties [effectiveness of surface tension reduction (γCMC), critical micelle concentration (CMC), efficiency of surface tension reduction (pC20), maximum surface excess concentration (ΓCMC), minimum area/molecule at the interface (Amin), and the CMC/C20) ratio] of well‐purified N‐substituted glycine derivatives, having the structural formula RC(O)N(R′)CH2COONa, where RC(O)=lauroyl, myristoyl, or oleoyl, and R′=Et, Pr, Bu, CH2CH2OH or CH2CH2CH2OCH3, were investigated at 25°C in hard river water and distilled water. These surfactants show greater surface activity in hard river water than in distilled water. The effect of both the main alkyl chain R and the N‐substituent R′ on surface properties was elucidated, the oleoyl group showing properties equivalent to that of a C16 saturated acyl group. A linear relationship was observed between the pC20 or CMC values and the number of carbon atoms in the alkyl chain R or in R′ when it was alkyl. With increase in the number of carbon atoms in either R or the N‐substituent R′ when it is alkyl, both pC20 and micelle‐forming ability increase, although the effect of R′ on the foregoing two surface properties is lower than that of R. When R′ is (CH2)3OCH3, however, the results suggest that R′ is only partly removed from contact with the aqueous phase either upon adsorption at the water/air interface or upon micellization. It increases Amin, is equivalent only to an ethyl group in its effect on pC20 and to a methyl group in its effect on CMC, and, in contrast to the effect of R′ when it is alkyl, produces no increase in the CMC/C20 ratio. As a result, γCMC increases with R when R′ is alkyl and decreases with R when R′ is (CH2)3OCH3.
Assembly properties of the aggregates resulting in the solubilization of phosphatidylcholine bilayers by sodium cholate
Authors: de la Maza Alfonso , Parra José Luis 
Published: November 2006

AbstractThe interaction of sodium cholate with phosphatidylcholine liposomes was investigated. Permeability alterations were detected as a change in 5(6)‐carboxyfluorescein (CF) released from the interior of vesicles and bilayer solubilization as a decrease in the static light‐scattered by liposomes. Free surfactant concentration at subsolubilizing and solubilizing levels showed, respectively, values that were lower than and similar to the surfactant critical micelle concentration, and indicated that permeability alterations and solubilization were determined, respectively, by the action of surfactant monomer and by the formation of mixed micelles. A direct relationship was established in the initial steps [effective surfactant/lipid molar ratio (Re) lower than 0.07] between the growth of vesicles, the leakage of entrapped CF (fluidity of vesicles), and Re. These changes could be correlated with the increasing presence of surfactant molecules in the outer monolayer of vesicles and its saturation. The subsequent increase in Re led to a lower growth of vesicles in coexistence with a similar increase in the CF release. This behavior could be related to a increased rate of flipflop of the sodium cholate molecules, making the inner monolayer also available for the interaction with added surfactant. A direct dependence was also established in the initial solubilization steps (Re values up to 0.6) between the surfactant‐phosphatidylcholine aggregate size, the static light‐scattering of the system, and Re. In the Re interval 0.36–0.84 mixed vesicles and mixed micelles coexisted.
Mechanism of micelle formation in sodium dodecyl sulfate and cetyltrimethylammonium bromide
Authors: Topallar Hüseyin , Karadag Birgül 
Published: November 2006

AbstractpH changes as a function of concentration for sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) were observed by addition of 1 N HCl and 1 N KOH. pH values increased up to the critical micellar concentration (CMC) for the SDS/HCl system and decreased for the CTAB/KOH system. In the SDS/HCl and CTAB/KOH systems, the micellar phase had a fixed composition and was homogeneous and monodisperse above the CMC. However, in the SDS/KOH and CTAB/HCl systems, pH values increased continuously and gradually below and above the CMC, and the properties of the micellar phase changed as a function of concentration, giving rise to inhomogeneity and polydispersity.