bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of nanoporous organosilicate hybrid thin films with a bimodal pore size distribution
Authors: Hyeon‐Lee J , Rhee J , Yim JH , Jeong HD , Gidley DW 
Published: January 2005

AbstractLow dielectric poly[methylsilsesquioxane‐ran‐trifluoropropylsilsesquioxane‐ran‐(2,4,6,8‐tetramethyl‐2,4,6,8‐tetraethylenecyclotetrasiloxane)silsesquioxane]s {P[M‐ran‐TFP‐ran‐(TCS)]SSQs} having various compositions were synthesized using trifluoropropyl trimethoxysilane, methyl trimethoxysilane and 2,4,6,8‐tetramethyl‐2,4,6,8‐tetra(trimethoxysilylethyl)cyclotetrasiloxane. The chemical composition of the polymers and the content of SiOH end‐groups were controlled by adjusting the reaction conditions, and they were characterized by 1H‐NMR. The thermally decomposable trifluoropropyl groups on the P[M‐ran‐TFP‐ran‐(TCS)]SSQ backbone and heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin (CD) were employed as pore generators. The dielectric constants of the porous CD/P[M‐ran‐TFP‐ran‐(TCS)]SSQ films were in the range 2.0–2.7 (at 100 kHz) depending on the concentration of the porogens, and showed no change over 4 days under aqueous conditions. The pore size of the films showed a bimodal distribution, with diameters of ca 0.5–1.0 nm for those originating from the trifluoropropyl groups and 1.7 nm from the CD. The elastic modulus and hardness of the 30 vol% CD‐blended film with a dielectric constant of 2.26 were 2.40 and 0.38 GPa, respectively, as determined by a nanoindenter. Copyright © 2005 Society of Chemical Industry
High‐pressure effect on organic reactions in fluorophobic media
Authors: Jenner Gérard , Gacem Badra 
Published: January 2005

AbstractThe kinetic effect of fluorophobic interactions was examined in Diels–Alder reactions and the conjugate addition of amines to acrylonitrile at different pressures. Its magnitude is lower than for other solvophobic media (water, ethylene glycol). Activation volumes determined in perfluorohexane are less negative for Diels–Alder cycloadditions owing to reduced fluorophobic interactions under pressure, in line with a former study. At variance, the conjugate addition is more pressure sensitive in the fluorous medium owing to the combination of solvophobic acceleration and enhanced electrostriction. Some synthetic applications of the multiactivation method (pressure + fluorophobic activation) are presented with emphasis on the beneficial solvophobic properties of the fluorous medium. Copyright © 2003 John Wiley & Sons, Ltd.
Computational study of base‐induced skeletal conversion via a spirocyclic intermediate in dibenzodithiocinium derivatives by ab initio MO calculations
Authors: Okada Keiji , Tanaka Masato , Takagi Ryukichi 
Published: January 2005

AbstractReaction of 6‐methyl‐12‐oxo‐5H,7H‐dibenzo[b,g][1,5]dithiocinium salt (1‐SO) with methanolic KOH afforded a mixture of dibenzothiepin derivatives 2‐SO. In order to clarify the intermediates of the rearrangement, ab initio MO calculations with the HF/6–31G* basis set were performed on the reaction intermediates, the transition states and related compounds. The rearrangement was explained in terms of the usual [2,3]‐sigmatropic shift via a spirocyclic intermediate, followed by a 1,3‐shift of the sulfonyl group. However, a different type of rearrangement was observed in 6‐methyl‐5H,7H‐dibenzo[b,g][1,5]dithiocinium salt (1‐S), giving an unexpected dibenzothiepin derivative 3‐S along with a small amount of a ring‐opening product 8 under the same reaction conditions. The formation of 3‐S and 8 was understandable by the assumption of a cationic intermediate resulting from heterolytic cleavage at the benzyl position. Copyright © 2003 John Wiley & Sons, Ltd.
[2 + 3] Cycloaddition of C,C,N‐triphenylnitrone to trans‐substituted nitroethylenes in the light of an AM1 and AM1/COSMO computational study
Authors: Baranski Andrzej , Jasinski Radomir , Żurowski Kazimierz 
Published: January 2005

AbstractAM1 calculations suggest that the [2 + 3] cycloaddition of triphenylnitrone 1 to nitroalkenes 2a–c in the gas phase takes place in a concerted manner. However, the azolidine ring bonds C3—C4 and O1—C5 are not formed fully synchronously. Kinetic factors favor the formation of cycloadducts with nitro group in position C‐4 of the azolidine ring (path A). Introduction of toluene, acetone or acetonitrile as a reaction medium increases the activation barriers for both regioisomeric paths. Simultaneously, the energy profiles for path A undergo qualitative change. In this case, two transition states and an intermediate with zwitterionic character were localized by means of the AM1/COSMO method. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of methyl and vinyl substitution on the geometries, relative stabilities and Diels–Alder reactivities of phospholes: a DFT study
Authors: Geetha K. , Dinadayalane T. C. , Sastry G. Narahari 
Published: January 2005

AbstractEquilibrium geometries and the relative stabilities of 1H‐, 2H‐ and 3H‐phospholes and their methyl‐ and vinyl‐substituted analogs were computed at the B3LYP/6–31G* level. The transition states and products were located for the Diels–Alder reactions of all the dienes with ethylene. The effect of substitution on the geometries, relative stabilities and Diels–Alder reactivities of 1H‐, 2H‐ and 3H‐phospholes were analyzed. The relative stabilities predict that the substitution on phospholes prefers phosphorus over carbon. Computations show that the activation energies are not altered much by substitution of either methyl or vinyl groups on phospholes, but most of the substituted phospholes require slightly higher activation energies than the corresponding parent phospholes. 2H‐phospholes require lower activation energies than 1H‐ and 3H‐phospholes. The reactivity ordering based on FMO energy gaps and the activation energies are similar and follows the sequence 2H‐ > 3H‐ > 1H‐phospholes. The quantaum of charge‐transfer values from diene to dienophile at the transition states and distortion energies were calculated. Copyright © 2003 John Wiley & Sons, Ltd.
Magnetic interactions and optical spectral weights in Mott insulators with orbital degrees of freedom
Authors: Oleś Andrzej M. , Horsch Peter , Khaliullin Giniyat 
Published: January 2005

AbstractWe outline a unified approach to magnetic and optical properties of Mott insulators at orbital degeneracy, which provides deep insight into the complex spin–orbital physics. It introduces partial sum rules for individual optical excitations which follow from the multiplet structure of transition metal ions. We show that the observed anisotropies and the temperature dependence of the optical spectral weights in LaVO3 and LaMnO3 follow from spin and orbital correlations and are well understood within this approach. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Orbital polarons and optical conductivity in doped manganites
Authors: Bała J. 
Published: January 2005

AbstractOrbital polaron formation and the optical conductivity σ(ω) is investigated in the ferromagnetic and paramagnetic phases of doped (x = 1/4) manganites. Using finite‐temperature diagonalization techniques for a realistic spin–orbital model we find the three‐site correlations specific for the orbital polarized state and the σ(ω) which is characterized by a broad spectrum with pronounced optical gap due to polaron formation. At small frequencies (ω < t) the conductivity is dominated by an incoherent spectrum with spectral weight decreasing with increasing temperature leading to an activated behavior in resistivity above Tc. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protective effect of green tea polyphenol (‐)‐epigallocatechin gallate and other antioxidants on lipid peroxidation in gerbil brain homogenates
Authors: Lee Seong‐Ryong , Im Ki‐Jo , Suh Seong‐Il , Jung Jung‐Gil 
Published: January 2005

AbstractThe aim of this study was to compare the protective effects of green tea polyphenol (‐)‐epigallocatechin gallate (EGCG) and other well‐known antioxidants on the lipid peroxidation in gerbil brain homogenates. Oxidative stress was induced by H2O2 (10 mM) or ferrous ammonium sulfate (5 µM) and lipid peroxidation was studied. Hydrogen peroxide and ferrous ions are capable of oxidizing a wide range of substrates and causing biological damage. The reaction, referred to as the Fenton process, is complex and can generate both hydroxyl radicals and higher oxidation states of the iron. Thiobarbituric acid‐reactive substances (TBA‐RS) were used as a marker of lipid peroxidation. EGCG, trolox, lipoic acid, and melatonin reduced H2O2‐ or ferrous ion‐induced lipid peroxidation in a concentration‐dependant manner. In reducing the H2O2‐induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (0.66 µM), trolox (37.08 µM), lipoic acid (7.88 mM), and melatonin (19.11 mM). In reducing the ferrous ion‐induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (3.32 µM), trolox (75.65 µM), lipoic acid (7.63 mM), and melatonin (15.48 mM). Under the in vitro conditions of this experiment, EGCG was the most potent antioxidant in inhibiting H2O2 or ferrous ion‐induced lipid peroxidation in the gerbil brain homogenates. Copyright © 2003 John Wiley & Sons, Ltd.
In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis
Authors: Mahady Gail B. , Pendland Susan L. , Stoia Adenia , Chadwick Lucas R. 
Published: January 2005

AbstractMethanol extracts of the rhizomes of Sanguinaria canadensis, and the roots and rhizomes of Hydrastis canadensis, two plants used traditionally for the treatment of gastrointestinal ailments, were screened for in vitro antibacterial activity against 15 strains of Helicobacter pylori. The rhizome extracts, as well as a methanol extract of S. canadensis suspension‐cell cultures inhibited the growth of H. pylori in vitro, with a MIC50 range of 12.5–50.0 µg/ml. Three isoquinoline alkaloids were identiﬁed in the active fraction. Sanguinarine and chelerythrine, two benzophenanthridine alkaloids, inhibited the growth of the bacterium, with an MIC50 of 50.0 and 100.0 µg/ml, respectively. Protopine, a protopine alkaloid, also inhibited the growth of the bacterium, with a MIC50 of 100 µg/ml. The crude methanol extract of H. canadensis rhizomes was very active, with an MIC50 of 12.5 µg/ml. Two isoquinoline alkaloids, berberine and β‐hydrastine, were identiﬁed as the active constituents, and having an MIC50 of 12.5 and 100.0 µg/ml, respectively. Copyright © 2003 John Wiley & Sons, Ltd.
Brazilian Propolis: physicochemical properties, plant origin and antibacterial activity on periodontopathogens
Authors: Santos F. A. , Bastos E. M. A. F. , Maia A. B. R. A. , Uzeda M. , Carvalho M. A. R. , Farias L. M. , Moreira E. S. A. 
Published: January 2005

AbstractPropolis samples collected in the dry and rainy seasons, from an experimental apiary located in a cerrado vegetation region in Brazil were used in this study. Microscopic analysis showed the presence of 31 pollen types, secretory hairs (genus Baccharis) and fragments of plant epidermis. The oxidation rates and the wax content of the samples after physicochemical analyses were in agreement with the Cuban Guideline NRAG 870–88. A high performance liquid chromatography analysis showed a similar pattern of chromatograms, characterized by the presence of ten phenolic compounds. There was no signiﬁcant difference in the proﬁle of phenolic compounds and also in the total ﬂavonoid concentration in propolis samples collected in different seasons. Antibacterial assays were performed by the method of dilution of an ethanol extract of propolis (EEP) in agar (v/v%) and showed that all 16 A. actinomycetemcomitans strains tested were inhibited by propolis concentrations of 0.1% to 0.25%, and did not grow at all at 0.5%. The growth inhibition of six Fusobacterium spp. and 16 black‐pigmented anaerobes was observed at concentrations of 0.05% to 0.1%, and no growth was observed at 0.25%. There was no effect of seasonality on the inhibitory activity of propolis. The antibiotics tetracycline and meropenem were used as positive controls. Copyright © 2003 John Wiley & Sons, Ltd.
The protective effects of Propolis on hepatic injury and its mechanism
Authors: Won Seo Kyung , Park Mijung , Jung Song Yeon , Kim Sung‐Jin , Ro Yoon Kwang 
Published: January 2005

AbstractPropolis (PP) is a sticky substance that is collected from plants by honeybees. The purpose of this study was to investigate the protective effects of PP on hepatotoxicity induced by acetaminophen (AA, paracetamol) and the mechanism of its hepatoprotective effect. In rat hepatocyte culture, pretreatment with PP (1, 10, 100, 200 and 400 µg/mL, 24 h) signiﬁcantly decreased the cytotoxicity of AA (0.5 mm) in a dose‐dependent manner. In mice, pretreatment with PP (10 and 25 mg/kg, p.o., 7 days) also decreased the mortality and the incidence and severity of hepatic necrosis induced by AA (400 mg/kg, i.p.). After treatment with PP for 7 days, the hepatic enzyme activities of cytochrome P450 monooxygenases (P450s), UDP‐glucuronyltransferase, phenolsulphotransferase (PST), glutathione S‐transferase (GST) were measured in both rats and mice. In rats, PP (50 and 100 mg/kg, p.o.) decreased the activity of P4502E1, but signiﬁcantly increased the activities of GST and PST. On the other hand, in mice treated with PP (10 and 25 mg/kg, p.o.), the activities of P4501A2, 2B1, 3A4 and 2E1 were dramatically inhibited, and the activity of PST was signiﬁcantly enhanced. These results suggest that PP has a protective effect on hepatic injury, and that its effect may be explained by inhibition of phase I enzymes and induction of phase II enzymes. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation of wound healing activity of some herbal formulations
Authors: Mukherjee Pulok K. , Mukherjee Kakali , Rajesh Kumar M. , Pal M. , Saha B. P. 
Published: January 2005

AbstractThe wound healing activity of two herbal formulations (Himax ointment and lotion) containing Indradaru extract, i.e. Arjuna bark (Terminalia arjuna, Family‐Combretaceae), extract was evaluated for its wound healing potential in two types of wound models in rats (i) excision wound model and (ii) incision wound model. Both the formulations responded signiﬁcantly in both the wound models tested. The results were also comparable to that of the standard drug nitrofurazone used as a standard drug for comparison in this present investigation. The results were also comparable in terms of wound contracting ability, epithelization period, tensile strength and regeneration of tissues at the wound area. Thus, this investigation conﬁrms the use of the Himax ointment and lotion containing Terminalia arjuna extract as a wound‐healing agent as known from folklore medicine. Copyright © 2003 John Wiley & Sons, Ltd.
Covariance mapping in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Feldman Andrew B. , Antoine Miquel , Lin Jeffrey S. , Demirev Plamen A. 
Published: January 2005

AbstractA novel method for acquisition and numerical analysis of matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight mass spectral data is described. The digitized ion current transient from each consecutive laser shot is first acquired and stored independently. Subsequently, statistical correlation parameters between all stored transients are computed. We illustrate the uses of this event‐by‐event analysis method for studies of sample surface heterogeneity as well as for elucidating the mechanisms of ion formation in MALDI. Other potential applications of the method are also outlined. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of a bioactive β‐(1 → 3) polysaccharide (Curdlan) using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Chan T.‐W. D. , Tang K. Y. 
Published: January 2005

AbstractThis paper focuses on the development of MALDI sample preparation protocols for the analysis of a bioactive β‐(1 → 3) polysaccharide, i.e. Curdlan. The crude Curdlan sample was first separated into a low molecular weight water‐soluble portion and a high molecular weight water‐insoluble portion. The water‐soluble portion was analyzed using a standard MALDI sample preparation method developed for dextran analysis. Two low‐mass (<4000 Da) polysaccharide distributions differing by 16 Da were observed. For the analysis of the water‐insoluble portion, several sample preparation protocols were evaluated using GPC‐fractionated samples. A sample preparation method based on the deposition of the analyte solution with a mixture of 2,5‐dihydroxybenzoic acid (DHB) and 3‐aminoquinoline (3AQ) matrices in dimethyl sulfoxide (DMSO) at elevated temperature of 70°C was found to reliably produce good MALDI spectra. MALDI analysis of the water‐insoluble Curdlan portion gave number‐average (Mn) and weight‐average (Mw) molecular weights and polydispersity of 8000 Da, 8700 Da, and 1.10, respectively. Copyright © 2003 John Wiley & Sons, Ltd.
Some aspects of the stability of ion current in a matrix‐assisted laser desorption/ionization source
Authors: Ptasińska Sylwia , Michalak Leszek , Smolira Marcin 
Published: January 2005

AbstractThe effect of laser exposure (the number of laser shots) on the stability of production of matrix (gentisic acid, sinapinic acid, nicotinic acid and benzoic acid) and biomolecule (insulin and cytochrome‐c) ions is presented. Two methods of sample preparation, dried‐droplet and pressure, were examined. In the case of pressure preparation, the dry powder sample was pressed mechanically with a pressure of 30 MPa. The best results were obtained for the pressure method and gentisic acid as matrix. Copyright © 2003 John Wiley & Sons, Ltd.
Primary structural determination of N‐terminally blocked peptides from the bark of Eucommia ulmoides Oliv by mass spectrometric analysis
Authors: Huang Ren‐Huai , Zhang Ying , Wang Da‐Cheng 
Published: January 2005

AbstractSequencing of N‐terminally blocked proteins/peptides is a challenge since these molecules inhibit processing by Edman degradation. By using high accuracy Fourier transform ion cyclotron resonance (FTICR) tandem mass spectrometry and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS), the primary structures of two novel N‐terminally blocked antifungal peptides (EAFP1 and EAFP2), purified from the bark of Eucommia ulmoides Oliv, have been determined. The results show that the high mass accuracy provided by FTICR mass spectrometry is effective to determine the N‐terminally blocking group, and can simplify the task of spectral interpretation and improve the precision of sequence determination. The combination of MALDI‐TOFMS with carboxyl peptidase Y digestion was used to determine the C‐terminal 36‐ and 27‐residue sequences of EAFP1 and EAFP2, respectively, to provide the sequence linkage information for tryptic fragments. Compared with traditional peptide chemistry the advantage of mass spectrometric techniques is their simplicity, speed and sensitivity. Copyright © 2003 John Wiley & Sons, Ltd.
Ray casting free‐form deformed‐volume objects
Authors: Chen Haixin , Hesser Jürgen , Männer Reinhard 
Published: January 2005

AbstractA collection of techniques is developed in this paper for ray casting free‐form deformed‐volume objects with high quality and efficiency. The known inverse ray deformation approach is combined with free‐form deformation to bend the rays to the opposite direction of the deformation, producing an image of the deformed volume without generating a really deformed intermediate volume. The local curvature is estimated and used for the adaptive selection of the length of polyline segments, which approximate the inversely deformed ray trajectories; thus longer polyline segments can be automatically selected in regions with small curvature, reducing deformation calculation without losing the spatial continuity of the simulated deformation. We developed an efficient method for the estimation of the local deformation function. The Jacobian of the local deformation function is used for adjustments of the opacity values and normal vectors computed from the original volume, guaranteeing that the deformed spatial structures are correctly rendered. The popular ray casting acceleration techniques, like early ray termination and space leaping, are incorporated into the deformation procedure, providing a speed‐up factor of 2.34–6.56 compared to the non‐optimized case. Copyright © 2003 John Wiley & Sons, Ltd.
Useful Backward and Forward Reflections
Authors: Cripe Lloyd I. 
Published: January 2005

Pathways to Prominence in Neuropsychology: Reflections of
Twentieth-Century Pioneers. Anthony Y. Stringer, Eileen L. Cooley,
and Anne-Lise Christensen, 2002. New York: Psychology Press. 324 pp.,
$64.95.Pathways to Prominence in Neuropsychology discusses the
origin and development of research and clinical neuropsychology in the
20th century. This is an important first book to help us better
understand where we have been, where we are, where we are going and who
we are, but be forewarned that the writer of this review is extremely
biased, believing that history is both interesting and potentially
useful to enlighten our individual and collective journeys. The writing
of history, its facts and interpretations, is fraught with challenges
and pitfalls, especially when looking at ourselves. As the American
humorist Herb Shiner once said, “Nothing has changed the course
of history as much as the historian.
A Classic Renewed
Authors: Ogden Jenni A. 
Published: January 2005

Clinical Neuropsychology. Fourth Edition. Kenneth M. Heilman
and Edward Valenstein (Eds.). 2003. New York: Oxford University Press.
744 pp., $78.00 (HB).As a 1st-year graduate student and new convert to clinical
neuropsychology, the second book I purchased in this exciting area was
the first edition of Heilman and Valenstein's “Clinical
Neuropsychology” published in 1979. It will come as no surprise
to most readers that the first book I purchased was Lezak's first
edition of “Neuropsychological Assessment,” published 3
years earlier, and of course a required text for our graduate course.
As a teacher of that very same course over the past 18 years, I have
recommended the various editions of both these texts to my students as
the “standard” texts, a practice I imagine is shared
world-wide. Thus, at one level it seems almost unnecessary to write a
review of such a classic text, and at the same time to do it justice is
a humbling task which I have no hope of fulfilling. All I can do is
give a small taste of this latest offering edited by two of the great
neurologists (and neuropsychologists) of modern times.