bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of multiwall carbon nanotube on physical properties of poly(ethylene 2,6‐naphthalate) nanocomposites
Authors: Kim Jun Young , Kim Seong Hun 
Published: February 2006

AbstractPolymer nanocomposites consisting of multiwall carbon nanotube (MWCNT) and poly(ethylene 2,6‐naphthalate) (PEN) were prepared by a melt blending process in a twin‐screw extruder. The storage modulus (G′) and loss modulus (G″) of the PEN/MWCNT nanocomposites increased with increasing frequency, and this increment being more significant at low frequency. The terminal zone slope of G′ for the PEN/MWCNT nanocomposites decreased with increasing MWCNT content, and the nonterminal behavior of those was related to the dominant nanotube–nanotube interactions at higher MWCNT content, leading to the formation of the interconnected or network‐like structures of MWCNT in the polymer nanocomposites. The decrease in the slope of the plot of log G′ versus log G″ for the PEN/MWCNT nanocomposites with increasing MWCNT content suggested the changes in the microstructures of the polymer nanocomposites by incorporating MWCNT. The incorporation of very small quantity of MWCNT significantly improved the mechanical properties of the PEN/MWCNT nanocomposites. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1062–1071, 2006
Polymorphism behavior of poly(ethylene naphthalate)/clay nanocomposites
Authors: Chua Yang Choo , Lu Xuehong , Wan Tong 
Published: February 2006

AbstractThermally stable organically modified clays based on 1,3‐didecyl‐2‐methylimidazolium (IM2C10) and 1‐hexadecyl‐2,3‐dimethyl‐imidazolium (IMC16) were used to prepare poly(ethylene naphthalate) (PEN)/clay nanocomposites via a melt intercalation process. The clay dispersion in the resulting hybrids was studied by a combination of X‐ray diffraction, polarizing optical microscopy, and transmission electron microscopy. It was found that IMC16 provided better compatibility between the PEN matrix and the clay than IM2C10, as evidenced by some intercalation of polymer achieved in the PEN/IMC16‐MMT hybrid. The effects of clay on the crystal structure of PEN were investigated. It was found that both pristine MMT and imidazolium‐treated MMT enhanced the formation of the β‐crystal phase under melt crystallization at 200 °C. At 180 °C, however, the imidazolium‐treated MMT was found to favor the α‐crystal form instead. The difference in clay‐induced polymorphism behavior was attributed to conformational changes experienced by the clay modifiers as the crystallization temperature changes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1040–1049, 2006
Ferromagnetic phase transition in ultra‐thin films
Authors: Tuleja S. , Kecer J. , Ilkovič V. 
Published: February 2006

AbstractThe ferromagnetic phase transition in ultra thin films is studied by the many body Green's function method based upon the Heisenberg model with the different surface exchange couplings with respect to bulk one plus a surface second order uniaxial anisotropy. The critical temperature of the system is studied as a function of the ratio Δ S = J S/J of the surface exchange couplings to the bulk ones and as a function of the surface single ion anisotropic strength K S2. A model calculation shows thatexist critical values Δ SC and K SC2 (cross over points). If Δ S > Δ SC or K S2 > K SC2, the critical temperature of the thin film is larger than the bulk one. We analyse various possible configurations for the surface exchange couplings J S and the surface single ion anisotropic strength K S2. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure and the site preference of chromium in Fe3Al alloy
Authors: Go A. , Pugaczowa‐Michalska M. , Dobrzyński L. 
Published: February 2006

AbstractThe TB‐LMTO‐ASA method is employed to obtain the electronic and magnetic structures as well as the site preference of chromium in Fe3–x Crx Al alloys. Quantitative agreement with the experimental results is obtained for site preferences, for total and local magnetic moments. Cr atoms are shown to be antiferromagnetically coupled with surrounding atoms. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation effects in the valence bands of ferromagnetic semiconductor EuS
Authors: Sharma A. , Nolting W. 
Published: February 2006

AbstractWe present a many body analysis of the multi‐band Kondo lattice model. The study is then combined with the first principles TB‐LMTO band structure calculations, in order to investigate the temperature dependent correlation effects in the 3p valence bands of the ferromagnetic semiconductor EuS. Some of the physical properties of interest like the quasi‐particle density of states (Q‐DOS), spectral density (SD) and quasi‐particle band structure (Q‐BS) are calculated and discussed. Therewith, we propose a spin resolved ARPES of the valence bands of EuS to be performed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First principle studies on the electronic structures of raspite‐ and scheelite‐structured PbWO4 and raspite with VO2+
Authors: Sun Yuanyuan , Zhang Qiren , Liu Tingyu , Yi Zhijun 
Published: February 2006

AbstractWe present first‐principle calculations on the electronic structures of perfect raspite‐ and scheelite‐structured PbWO4 (PWO). The results indicate that profiles of the electronic structures for the two types of PWO are similar to each other and the bandgap of RSP is 1.1 eV smaller than that of SSP. This bandgap difference between the two types of PWO is induced by the different coordination of W. The electronic structure of raspite‐structured PWO containing oxygen vacancies $ {\rm V}^{+2}_{\rm O} $ is also calculated. An additional energy level occurs in the forbidden band, which would induce an absorption peaking at 620 nm in the yellow region. Compared to the absorption spectra of scheelite‐structured PWO with $ {\rm V}^{+2}_{\rm O} $, it is concluded that in PWO crystals the different ligand field around $ {\rm V}^{+2}_{\rm O} $ would not greatly affect the absorption band related to $ {\rm V}^{+2}_{\rm O} $. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of vertical‐bloch‐line chains in the walls of the first kind of dumbbell domains subjected to static bias field at various in‐plane fields
Authors: Wang L. N. , guo G. X. , Zhen C. M. , Nie X. F. 
Published: February 2006

AbstractFor the first kind of dumbbell domains (IDs) of garnet bubble films, the annihilating process of vertical bloch line chains (VBLs) subjected to an in‐plane field ($ H_{\rm ip} $) at various static bias fields ($ H_{\rm b} $) was experimentally studied. Three important relations have been obtained, which are the relations between $ H_{\rm ip}^{(1)} $, $ H_{\rm ip}^* $, $ H_{\rm ip}^{(2)} $ and $ H_{\rm b} $. here, $ H_{\rm ip}^{(1)} $ is the initial critical in‐plane field where VBLs in the walls of IDs are annihilated, i.e. some of the ID begin to be softened, $ H_{\rm ip}^* $ is designated as the in‐plane field where ID begins to soften to SB and $ H_{\rm ip}^{(2)} $ is the lowest in‐plane field at which all VBLs in the walls of IDs annihilate completely. by the experiment of the so‐called “tail‐cut”, it is found that each $ H_{\rm ip} $ from $ H_{\rm ip}^{(1)} $ to $ H_{\rm ip}^{(2)} $ corresponds to a certain length of VBL chains in the walls of IDs. the higher $ H_{\rm ip} $, the shorter the VBL chains. $ H_{\rm ip}^{(1)} $ and $ H_{\rm ip}^{(2)} $ correspond to the longest and shortest VBLs, respectively. it is also found that both $ H_{\rm ip} $ and $ H_{\rm b} $ play an important role during the annihilating of vbl chains in the walls of IDs. If $ H_{\rm b} $ is lower, $ H_{\rm ip}^{(1)} $, $ H_{\rm ip}^* $ and $ H_{\rm ip}^{(2)} $ are unchanged. with increasing $ H_{\rm b} $, especially being close to or higher than the standard stripe‐to‐bubble transition field ($ H_{\rm sb} \prime $), they all rapidly decrease. And they do not change further when $ H_{\rm b} $ is a little higher than the minimum collapse field of OHBs ($ H_0 \prime $). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exact exchange for correlated electrons
Authors: Novák P. , Kuneš J. , Chaput L. , Pickett W. E. 
Published: February 2006

AbstractThe cover picture is taken from the article by Pavel Novák that was chosen as Editor's Choice of this issue [1]. The figure shows the density of minority spin states in nickel oxide calculated by three commonly used approximations (LSDA, GGA, LDA+U) as well as using the newly proposed ‘Exact Exchange for Correlated Electrons’ (EECE) method. The EECE method treats the interactions between correlated electrons in a Hartree–Fock way, while all other interactions are described by the density functional theory. EECE is a promising starting point for the improvement of orbital‐dependent functionals within the density functional theory.Pavel Novák is the head of the ‘Spectroscopy of Magnetic Oxides’ group at the Institute of Physics of ASCR, Prague, Czech Republic. Most of his scientific activity is devoted to the calculation of the electronic structure of solids, but he also closely cooperates with several experimental groups. Particular attention is focused on the nuclear magnetic resonance and electronic structure of magnetic oxides with mixed valency of the cations.
Photoionization of C2F4 in the VUV region
Authors: Dos Santos A. S. , Brescansin L. M. , Lee M.‐T. , Machado L. E. 
Published: February 2006

AbstractWe report calculated cross sections and asymmetry parameters for photoionization out of the outermost valence orbital 2b2u of C2F4 for photon energies ranging from near‐threshold to 19 eV. We also report asymmetry parameters for photoionization out of the eight outermost orbitals of C2F4 at the He I radiation energy (21.23 eV). The iterative Schwinger variational method at the exact static‐exchange level is used to obtain the continuum photoelectron orbitals. Our calculated results are compared with experimental results available in the literature. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Laser desorption/ionization and laser ablation synthesis of new selenium oxide compounds from selenium(IV) dioxide
Authors: Špalt Zbyněk , Peña‐Méndez Eladia María , Alberti Milan , Havel Josef 
Published: February 2006

AbstractLaser desorption/ionization (LDI) and/or laser ablation (LA) of selenium dioxide crystals or its mixtures with sodium peroxide were studied using a commercial matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometer. It was found that LDI and LA of selenium (IV) dioxide not only ionizes SeO2, but also leads to the formation of several positively and negatively singly charged species: SeO (n = 0–2), Se, SeO (n = 0–4), Se2O (n = 3–7), Se3O (n = 4–9), Se4O (n = 8–10). A rather high yield of selenium species in the positive ion mode, Se (m = 1–8) and SemOH+ (m = 3–7), was obtained by using the MALDI approach while the species detected in the negative ion mode, SeO (n = 0–4), Se2O (n = 3–7), Se3O (n = 4–9), and Se4O (n = 9, 10), were the same as those observed during LDI/LA of selenium dioxide. The addition of sodium peroxide to selenium dioxide with the aim of enhancing its oxidation and thus increasing the production of SeO4 product resulted in extensive cationization of the species with sodium or potassium. The following positively and negatively charged species were identified: Se+, Se, Se2OH+, Se2ONa+, SeO (n = 0–3), and Se2O (n = 0, 1, 4). Also observed in mass spectra of such mixtures, various mixed sodium and/or potassium adducts with selenium oxide species, e.g. Se2O4K2Na−, were identified. In all, 26 totally new species, Se2O (n = 3–6), Se3O (n = 4–9), Se4O (n = 8–10), Se4O11H, Se4O12H, Se2O4Na−, Se2O5HNa−, Se2O5HNa, Se3O6K2Na−, Se3O6K2Na, Se2ONa+, and SemOH+ (m = 3–7), were described for the first time. Also, for the first time, the formation of selenium(IV) diperoxide, O‐O‐Se‐O‐O or O2SeO2, is described. The stoichiometries of the compounds generated were confirmed using isotopic pattern modeling. Copyright © 2006 John Wiley & Sons, Ltd.
Evidence for an hereditary defect in taurine transport in the ciliary epithelium of an inbred strain of rabbits
Authors: Harris T. M. , Nance C. S. , Sheppard L. B. , Fox R. R. 
Published: February 2006

AbstractThe concentration of taurine in the aqueous humour and serum of 21 rabbits with hereditary buphthalmia (Bu rabbits‐genotypebu/bu) was compared with the aqueous and serum taurine levels of eight strain‐related normal rabits (JAX) and nine non‐strain‐related normal rabbits (MCV). There was a significant difference in the mean aqueous taurine concentration in each of the three groups. The Bu rabbits had only 29% of the MCV rabbits' level while the JAX rabbits were intermediate with 56% of the MCV level. It is suggested that some of the JAX rabbits may be heterozygous and the Bu rabbits homozygous for a semi‐dominant allele of a gene that is less efficient in taurine transport in the ciliary epithelium than the normal allele represented by the MCV animals.
Hair root analysis in X‐linked ichthyosis
Authors: Dancis J. , Jansen V. , Hutzler J. 
Published: February 2006

AbstractHair roots have been analysed in a large kindred with X‐linked ichthyosis associated with steroid sulphatase deficiency. Enzyme activity in individual hair roots was assayed for the steroid sulphatase: neutral α‐glucosidase ratio, the latter serving as an indicator of the general metabolic activity of the hair root. The distribution of the enzyme ratios in the individual hair roots in the heterozygotes described a normal curve suggesting origin from a single population of cells. The results differed strikingly from the irregular distribution of enzyme activities in hair roots of Lesch‐Nyhan disease, where mosaicism occurs. It is suggested that the maternal and paternal genes for steroid sulphatase remain activein vivo in each cell in the hair root in apparent contradiction to the Lyon hypothesis. The observation is consistent with that previously reported for skin fibroblastsin vitro. Sulphatase activity in female controls was minimally greater than in males but the difference was not statistically significant.
Organic acids and branched‐chain amino acids in body fluids before and after multiple exchange transfusions in maple syrup urine disease
Authors: Shigematsu Y. , Kikuchi K. , Momoi T. , Sudo M. , Kikawa Y. , Nosaka K. , Kuriyama M. , Haruki S. , Sanada K. , Hamano N. , Suzuki Y. 
Published: February 2006

AbstractWe successfully treated a critically ill infant with the classical type of maple syrup urine disease by multiple exchange tranfusions via a peripheral artery and vein and with positive supplementation in the early stage of therapy. Clinical improvement was definite after the plasma leucine level fell below 1 mmol/l. There was a close linear correlation between plasma concentrations of branched‐chain amino acids and their corresponding branched‐chain α‐keto acids and branched‐chain α‐hydroxy acids. α‐Hydroxy acids were more easily excreted in the urine than α‐keto acids and amino acids. Our studies on urinary organic acids supported the existence of minor metabolic pathways of branched‐chain α‐keto acids, although they were not though to be important in eliminating accumulated α‐keto acids. Urinary excretion of succinic acid and α‐ketoglutaric acid, which are components of the citric acid cycle, increased transiently during the patient's convalescence. The cerebrospinal fluid/plasma ratios for branched‐chain amino acids, α‐keto acids, and α‐hydroxy acids were very high before the transfurions and decreased after improvement. The cerebrospinal fluid/plasma rations for 5‐carvon acids, α‐ketoisovaleric acid and α‐hydroxyisiovaleric acid were much higher than for other branched‐chain acids not only in the patients but also in normal controls. Cerebrospinal fluid levels of α‐ketoisocaproic acid and α‐hydroxyisovaleric acid were as high as 1 mmol/l in our patient.
Granulocyte dysfunction in transcobalamin II deficiency responding to leucovorin or hydroxocobalamin‐plasma transfusion
Authors: Seger R. , Fràter‐Schröder Marijke , Hitzig W. H. , Wildefeuer A. , Linnell J. C. 
Published: February 2006

AbstractGranulocytes from a 6‐year‐old boy with congenital transcobalamin II (TCII) deficiency were found to have abnormally low antibacterial activity againstStaphylococcus aureus and very low intracellular levels of the cobalamin coenzymes. Transfusion of hydroxocobalamin (OH‐Cbl) bound to normal plasma temporarily restored granulocyte bactericidal activity and increased cellular levels of the cobalamin coenzymes. Granulocyte function was also temporarily restored by oral Leucovorin. The defect appeared to be causally related to the patient's TC II deficiency and indirectly to a deficiency of cobalamin and folate coenzymes.
D‐2‐hydroxyglutaric aciduria: Case report and biochemical studies
Authors: Chalmers R. A. , Lawson A. M. , Watts R. W. E. , Tavill A. S. , Kamerling J. P. , Hey E. , Ogilvie D. 
Published: February 2006

AbstractA patient with protein‐losing gastroenteropathy and egg allergy has been shown to have a previously unrecognized organic aciduria,d‐2‐hydroxyglutaric aciduria. The observations made are consistent with an inherited metabolic disorder in the catabolism of 5‐aminolaevulinate possibly due to deficient activity of a specificd‐2‐hydroxyglutarate dehydrogenase.
Screening for organic acidurias and amino acidopathies in newborns and children
Authors: Chalmers R. A. , Purkiss P. , Watts R. W. E. , Lawson A. M. 
Published: February 2006

AbstractThis investigation was undertaken in order to define the place of multidisease screening for inborn errors of metabolism in paediatric practice with particular reference to the organic acidurias, and to compare the efficiency of organic acid screening as a detection method for inborn errors of metabolism with that of amino acid screening on urine. The clinical criteria adopted for the selection of patients were: (i) acute unexplained illness in the newborn or infant; (ii) unexplained developmental delay in infancy or early childhood.The derivatized organic acids were separated by automated gas chromatography and identified by mass spectrometry. The patients were also screened for abnormal amino acidurias by thin‐layer chromatography supplemented by automated quantitative column chromatography when visual inspection of the thin‐layer chromatography plates suggested that the result might be abnormal.Six hundred and ninety‐five patients were studied. The incidence of abnormalities was higher in the material which was referred from other hospitals. We attribute this to the more extensive preliminary investigation to which these cases had been subjected before our help was sought than was the case in patients referred from our hospital.We conclude that screening for organic acidurias on the basis of the broad criteria which we originally specified is unproductive and not cost‐effective and that screening for organic acidurias should be confined to acutely ill neonates and young children who have been systematically evaluated biochemically by other means. A suitable scheme of investigation which need not involve a clinically unacceptable delay is proposed.Organic acid analysis by the present methods detected about ten times more abnormalities than amino acid analysis, or three times more if one considers only the known and likely inherited metabolic abnormalities in this series. The amino acidopathies were often diagnosed more precisely by the associated organic aciduria and only a few of the known inborn errors of metabolism require amino acid analysis exclusively for their identification. The present type of urinary organic acid analysis used as part of the investigation scheme which we have described will identify about one third of the approximately 180 inherited metabolic diseases with known enzyme defects. Organic acid analysis also detects other disorders and usually provides more information about the underlying biochemical derangement than does amino acid analysis alone.
Citrullinaemia: The possibility of prenatal diagnosis
Authors: Christensen E. , Brandt N. J. , Philip J. , Kennaway N. G. 
Published: February 2006

AbstractArgininosuccinate synthetase activity in amniotic fluid cells from a fetus at risk for citrullinaemia was low compared to the activity in amniotic fluid cells from a normal fetus, but five times the activity in fibroblasts from a patient with citrullinaemia. These enzyme values indicated a normal or heterozygous fetus.Chromosome analysis of the amniotic fluid cells from the fetus at risk, however, showed an unusual X/20 translocation. As we could not guarantee the delivery of a normal child, the parents chose to have a therapeutic abortion. Argininosuccinate synthetase activity in the liver and kidney of the aborted fetus was in the normal and heterozygous range respectively, confirming the prenatal diagnosis.The activity in the father's fibroblasts was low, less than 10% of normal. The difficulty of interpreting the results of prenatal diagnosis in such a family and the importance of studying parental cells are discussed.
Combined iminoglycinuria and cystine‐ and dibasic aminoaciduria in patients with propionic acidaemia and 3‐methylcrotonylglycinuria
Authors: Purkiss P. , Chalmers R. A. , Borud O. 
Published: February 2006

AbstractUrinary amino acids have been determined in six patients with propionic acidaemia, one of whom also showed 3‐methylcrotonylglycinuria. Two patients, including the subject with 3‐methylcrotonylglycinuria, showed a gross aminoaciduria with features of both cystinuria and iminoglycinuria. We suggest a defect in certain amino acid transport systems in some patients with these disorders.
Reproductive counselling for adolescent females with phenylketonuria
Authors: Tice Kathleen S. , Wenz Elizabeth , Jew Katherine , Koch R. 
Published: February 2006

SummaryIt is our goal to provide young adolescents with the information needed to make an informed choice, and a support system for them and their families, in whatever they choose.

Sterilization is not advocated.

Pregnancy is not advocated.

Reliable birth control methods are encouraged.

Organized reproductive counselling is essential using concrete problem solving—diagram, taste tests, etc.

Diet trial before or during pregnancy requires aninformed understanding of the responsibilities of parenthood.
Prenatal diagnosis of I‐cell disease by measuring altered α‐Mannosidase activity in amniotic fluid
Authors: Owada M. , Nishiya O. , Sakiyama T. , Kitagawa T. 
Published: February 2006

AbstractPrenatal diagnoses of I‐cell disease were carried out by examination of the amniotic fluid and cultured amniotic cells in four cases of high‐risk pregnancy in three different families. Three of the four fetuses were diagnosed as having I‐cell disease, on the basis of observation of abnormally increased activity of lysosomal acid hydrolases in the amniotic fluid and their decreased activity in cultured amniotic cells, thus leading to therapeutic abortion. α‐Mannosidase in the amniotic fluid of the fetuses with I‐cell disease exhibited significant alterations in pH profile,Km value, thermal stability and isoelectric focusing pattern, compared with the enzyme in normal controls. The results indicate that prenatal diagnosis of I‐cell disease may be accomplished by demonstration of altered enzymological characteristics of α‐mannosidase in the supernatant of amniotic fluid. The significance of the alteration of α‐mannosidase in the amniotic fluid is not known.