bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isomerisation of Erythro‐ and Threo‐Succinyl Units in Alternating Alkene‐Maleic Acid Copolymers: A Promising Route to New Microstructures
Authors: Komber Hartmut , Steinert Volker 
Published: January 2005

AbstractSummary: A first route to the isomerisation of erythro‐ and threo‐2,3‐disubstituted succinyl units in alternating alkene‐maleic acid copolymers is presented. The isomerisation reactions of the disodium salt of ethene‐maleic acid copolymer were carried out in aqueous solution at 180–240 °C in an autoclave. It is demonstrated that the erythro‐content can be changed from 17% up to 67%. The dissociation of methine CH bonds with the intermediate formation of a sp2 hybridised carbon is proposed as the mechanism.Isomerisation equilibrium between the threo‐ and erythro‐form of the 2,3‐disubstituted succinyl unit.imageIsomerisation equilibrium between the threo‐ and erythro‐form of the 2,3‐disubstituted succinyl unit.
Cover Picture: Macromol. Rapid Commun. 2/2005
Authors: Hafrén Jonas , Córdova Armando 
Published: January 2005

Cover: The first direct organocatalytic ring‐opening polymerization from cellulose fibers is presented. The synthesis was based on organocatalytic bulk ring‐opening polymerization (ROP) of ε‐caprolactone with cellulose cotton fiber and filter paper as the initiators. Organic acid catalysis provides a new method for the synthesis of valuable nanomaterials as well as polyesters for biomedical applications.Further details can be found in the Communication by J. Hafrén* and A. Córdova* on page 82.
The role of ASTM E27 methods in hazard assessment part II: Flammability and ignitability
Authors: Britton Laurence G. , Cashdollar Kenneth L. , Fenlon William , Frurip David , Going John , Harrison B. Keith , Niemeier Jeff , Ural Erdem A. 
Published: January 2005

AbstractAccurate flammability and ignitability data for chemicals form the cornerstone of procedures used to assess the hazards associated with commercial chemical production and use. Since 1967 the ASTM E27 Committee on the Hazard Potential of Chemicals has issued numerous, widely used consensus standards dealing with diverse testing and predictive procedures used to obtain relevant chemical hazard properties. The decision to issue a standard rests solely with the membership, which consists of representatives from industry, testing laboratories, consulting firms, government, academia, and instrument suppliers. Consequently, the procedures are automatically relevant, timely, and widely applicable. The purpose of this paper is to highlight some of the widely used standards, complemented with hypothetical but relevant examples describing the testing strategy, interpretation, and application of the results. A further goal of this paper is to encourage participation in the consensus standards development process.The paper is published in two parts. The first part (in the preceding issue of Process Safety Progress) dealt with the E27 standards pertaining to thermodynamics, thermal stability, and chemical compatibility. The second part, published here, focuses on the flammability, ignitability, and explosibility of fuel and air mixtures. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
High‐Tccuprate superconductivity in a nutshell
Authors: Won Hyekyung , Haas Stephan , Parker David , Maki Kazumi 
Published: January 2005

AbstractSince the discovery of high‐Tccuprate superconductivity in 1986 many new experimental techniques and theoretical concepts have been developed. In particular it was shown that the BCS theory of d‐wave superconductivity describes semi‐quantitatively the high‐Tcsuperconductivity. Furthermore, it was demonstrated that Volovik's approach is extremely useful for finding the quasiparticle properties in the vortex state. Here we survey these developments and forecast future directions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hubbard model in the ferromagnetic state. Dimer and trimer approach
Authors: Matlak M. , Słomska T. , Grabiec B. 
Published: January 2005

AbstractWe consider the Hubbard model for the sc lattice which consists of interacting, parallel lying dimer (trimer) planes. Each plane is a collection of equidistant, interacting, parallel lying dimers (trimers). We apply the exact solution of the dimer (trimer) problem after introducing the intrinsic symmetry breaking leading to the ferromagnetic ordering. We present preliminary, test results concerning the phase diagram of the system. In both approximations (dimer and trimer approach) there is a threshold for the ferromagnetic ordering at the Coulomb repulsion U = Ucr. The trimer approach gives a better saturation for the Curie temperature TC vs. U in comparison to the dimer approach. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mutagenic and antimutagenic potential of the medicinal plants M. laevigata and C. xanthocarpa
Authors: Fernandes J. B. F. , Vargas V. M. F. 
Published: January 2005

AbstractAqueous extracts of medicinal plants (Mikania laevigata and Campomanesia xanthocarpa) were screened for the presence of mutagenic activity in the Salmonella/microsome assay. The extracts of Campomanesia xanthocarpa showed frameshift (TA97a strain) signs of mutagenic activity without exogenous metabolism (S9 fraction). The infusions of Mikania laevigata, negative for mutagenic activity, showed high percentages of inhibition of mutagenesis induced by mutagens 2AF (2‐aminoﬂuorene), in the presence of exogenous metabolism (S9 fraction), for frameshift (TA98) and base pair substitution (TA100) lesions. In addition, these inhibitions were observed against mutagen SAZ (sodium azide) in assays with the TA100 strain, without exogenous metabolism (S9 fraction). A synergistic effect was also observed in frameshift mutagenic events, with direct action in the presence of 4NQO (4‐oxide‐1‐nitroquinoline) and a tendency to a low percentage of action enhancement, in the presence of the 2AF mutagen. The variable responses observed in the extract assays show the potentials for interaction of the different active principles in genetic material. Copyright © 2003 John Wiley & Sons, Ltd.
Antibacterial and antifungal activity of juniper berry oil and its selected components
Authors: Filipowicz Natalia , Kamiński Marcin , Kurlenda Julianna , Asztemborska Monika , Ochocka J. Renata 
Published: January 2005

AbstractJuniper berry oil is stated to possess a wide spectrum of pharmacological activities and its monographs are included in some National Pharmacopoeias. The antibacterial and antifungal activity of the oil was reported by some authors. In our study we estimated the antibacterial and antifungal activity of three different juniper berry oils and their main components. All the micro‐organisms used in this experiment were isolated from patients of Regional Hospital of Gdańsk and some of them showed resistance against commonly used antibiotics. Only one of the oils (labelled A) revealed good antimicrobial properties. None of the single oil components was a stronger antibacterial and antifungal inhibitor than the oil A itself. Our data suggest that the antimicrobial activity of juniper oil A is the result of either the speciﬁc composition of the oil A (highest concentration of (−)‐α‐pinene, p‐cymene and β‐pinene) or activity of a single non‐identiﬁed compound. The presence of an adulterant in the oil was excluded. Copyright © 2003 John Wiley & Sons, Ltd.
The protective effect of Allium sativum L. clove aqueous and methanolic extracts against hypoxia‐induced lethality in mice
Authors: Hosseinzadeh Hossein , Sadati Nargess 
Published: January 2005

AbstractThe antihypoxic activity of Allium sativum clove (garlic) aqueous and methanolic extracts was studied in mice.The extracts of garlic showed that the antihypoxic effect was dose‐dependent. The minimum effective doses of aqueous and methanolic extracts were 0.2 g/kg and 5.12 g/kg, respectively. Phenytoin, 50 mg/kg, and R‐phenylisopropyladenosine (R‐PIA), 1.6 mg/kg (R‐PIA) as positive controls increased survival time up to 52.5 ± 2.9 min and 120.5 ± 6 min, respectively, compared to normal saline (34.73 ± 0.71 min). The high doses of aqueous (16.9 g/kg) and methanolic (12.8 g/kg) extracts increased survival time up to 73.17 ± 4.9 and 68.41 ± 3.7, respectively.These results indicated that the extracts of A. sativum cloves have a protective effect against hypoxia‐induced lethality in mice. Copyright © 2003 John Wiley & Sons, Ltd.
The activity against leukocyte eicosanoid generation of essential oil and polar fractions of Adesmia boronioides Hook.f.
Authors: González S. B. , Houghton P. J. , Hoult J. R. S. 
Published: January 2005

AbstractThe polar fractions (methanol and aqueous extract) and essential oil of Adesmia boronioides aerial parts were tested in vitro at concentrations of 15 and 50 µg/mL, for their effects on the COX and 5‐LOX pathways of eicosanoid generation (TXB2, PGE2 and LTB4) in stimulated rat peritoneal leukocytes. Potent inhibition of LTB4 generation was displayed by the methanol extract and the essential oil, whereas the aqueous extract was essentially inactive. The methanol extract also caused potent inhibition of TXB2 generation but the essential oil and the aqueous extract were much less active. The effects on PGE2 production were much less striking, implying that the main effect is on thromboxane synthetase rather than on COX. Although the essential oil caused LDH release in leukocytes treated concurrently with ionophore, suggesting substantial toxicity to the cells, this extract did not affect cell viability according to the MTT test when incubated with the cells in the absence of ionophore. The two other extracts did not affect cell viability at the concentrations tested. It is concluded that Adesmia boronioides contains substance(s) that preferentially inhibit the 5‐lipoxygenase activity of arachidonic acid metabolism and suggest that this may contribute to the antiinﬂammatory actions of extracts of this plant. Copyright © 2003 John Wiley & Sons, Ltd.
Essential amino acids interacting with flavonoids: A theoretical approach
Authors: Codorniu‐Hernández Edelsys , Mesa‐Ibirico Ariel , Hernández‐Santiesteban Richel , Montero‐Cabrera Luis A. , Martínez‐Luzardo Francisco , Santana‐Romero Jorge L. , Borrmann Tobias , Stohrer Wolf‐D. 
Published: January 2005

AbstractThe interaction of two flavonoid species (resorcinolic and fluoroglucinolic) with the 20 essential amino acids was studied by the multiple minima hypersurface (MMH) procedures, through the AM1 and PM3 semiempirical methods. Remarkable thermodynamic data related to the properties of the molecular association of these compounds were obtained, which will be of great utility for future investigations concerning the interaction of flavonoids with proteins. These results are compared with experimental and classical force field results reported in the available literature, and new evidences and criteria are shown. The hydrophilic amino acids demonstrated high affinity in the interaction with flavonoid molecules; the complexes with lysine are especially extremely stable. An affinity order for the interaction of both flavonoid species with the essential amino acids is suggested. Our theoretical results are compared with experimental evidence on flavonoid interactions with proteins of biomedical interest. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Wigner function of the rotating Morse oscillator
Authors: Stanek Jerzy , Konarski Jerzy 
Published: January 2005

AbstractWe present an analytical expression of the Wigner distribution function (WDF) for the bound eigenstates of the rotating Morse oscillator (RMO). The effect of rotational excitation on the WDF on the quantum phase space has been demonstrated. This effect has been visualized by a series of contour diagrams for given rovibrational quantum states. Rotations of the molecule have been proved to qualitatively and quantitatively change the Wigner function. As a result, the most probable distance between atoms in a rotating molecule changes, and depends on the parity of the vibrational quantum number. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Microcapillary liquid chromatography/tandem mass spectrometry using alkaline pH mobile phases and positive ion detection
Authors: Tomlinson Andy J. , Chicz Roman M. 
Published: January 2005

AbstractExtending the dynamic range of microcapillary liquid chromatography/tandem mass spectrometry (LC/MS/MS) peptide sequencing methods is essential for extracting new discoveries from proteomic studies. The complexity of global protein digests and in vivo processed peptide repertoires (as isolated from immunologically important HLA complexes) have led to the development of novel separation methods to increase the number of peptides identified by a single analysis. Separation of complex mixtures by multidimensional high‐performance liquid chromatography (HPLC) decreases the number of isolated peptides contained in each fraction and increases the likelihood of detecting low abundant peptides in a background of dominant signals. In this study, we have evaluated the use of two dimensions of reversed‐phase chromatography for resolving and sequencing naturally processed HLA‐A2 presented peptide repertoires. The first dimension of separation was reversed‐phase chromatography using the strong ion pairing reagent trifluoroacetic acid (TFA) to ensure the highest efficiency of peptide fractionation. The second dimension of reversed‐phase chromatography was online with an electrospray ionization (ESI) ion trap mass spectrometer. Mobile phases used for the second dimension of chromatography were modified with volatile reagents including a contemporary acetate‐modified acidic solvent, which was compared with mobile phases prepared with ammonium hydroxide at an alkaline pH. As expected, we demonstrate improved separation of the HLA‐A2 presented fractions using the alkaline pH conditions. However, less obvious was the improved peptide signal‐to‐noise detected for peptide signals by positive ion ESI ion trap mass spectrometric detection, which was attributed to a reduced chemical background when using the alkaline pH mobile phases that allowed the ion trap to fill with the peptide ions until the automatic gain control detected a full trap. The term ‘wrong‐way‐round ionization’ has been used to describe intense [M+H]+ ions generated during ESI under strongly basic solutions. Ultimately, a larger number of the HLA‐A2 peptide repertoire was sequenced by coupling TFA‐modified reversed‐phase fractionation with alkaline‐modified microcapillary LC/MS/MS analysis of each fraction. In the present report, we compare the two second‐dimension approaches and demonstrate the quality of data that was acquired using alkaline pH reversed‐phase conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Mass spectrometric study of aliphatic α‐carbonyl azides
Authors: Duarte M. Filomena , Martins Filipa , Fernandez M. Tereza , Langley G. John , Rodrigues Paula , Barros M. Teresa , Costa M. Lourdes 
Published: January 2005

AbstractA series of derivatives of 2‐azidoacetic acid and 2‐azidoacetone were synthesized and their behaviour under electron ionization conditions was investigated. This paper reports the electron ionization fragmentation mechanisms for five aliphatic α‐carbonyl azides, which were clarified by accurate mass measurements and B/E linked scans. The substituent influences the abundance and the nature of the ions resulting from the molecular ion fragmentation. Copyright © 2003 John Wiley & Sons, Ltd.
Somatostatin receptor scintigraphy with 99mTc-depreotide (neospect) in discriminating between malignant and benign lesions in the diagnosis of lung cancer: a pilot study
Authors: Bååth M. , Kölbeck K. G. , Danielsson R. 
Published: January 2005

Purpose: To evaluate the diagnostic value of a new somatostatin analog, 99mTc-Depreotide, in differentiating benign from malignant lesions in patients with pulmonary nodules or masses. Material and Methods: A pilot study was performed on 28 patients referred to our Lung Department on suspicion of lung cancer. A chest X-ray, computed tomography (CT) of the thorax and upper abdomen, and scintigraphy were done - scintigraphy following the administration of 740 MBq 99mTc-Depreotide. Planar and tomographical imaging of the thorax and whole-body scanning with a gamma camera were done, and diagnostic outcome of the scintigrams was compared to CT, pathology, and clinical outcome. Results: Of 21 patients who had a focal high uptake of Depreotide, 17 were malignancies. One patient had two lesions with high Depreotide uptake, lung cancer, and pneumonia in the contralateral lung. Two patients with sarcoidosis and one with bilateral round atelectasis also had high Depreotide uptake bilaterally. Seven of the 8 patients with no uptake were true negative: 5 hamartomas and 2 round atelectases. One small lung cancer in the pleura sinus did not have Depreotide uptake. Conclusion: The somastotatin analog Depreotide is promising for discriminating between malignant and benign lung lesions.
Characterization of an Arabidopsis Enzyme Family That Conjugates Amino Acids to Indole-3-Acetic Acid
Authors: Staswick Paul E. , Serban Bogdan , Rowe Martha , Tiryaki Iskender , Maldonado Marién T. , Maldonado Mitsa C. , Suza Walter 
Published: January 2005

Abstract
Substantial evidence indicates that amino acid conjugates of indole-3-acetic acid (IAA) function in auxin homeostasis, yet the plant enzymes involved in their biosynthesis have not been identified. We tested whether several Arabidopsis thaliana enzymes that are related to the auxin-induced soybean (Glycine max) GH3 gene product synthesize IAA–amino acid conjugates. In vitro reactions with six recombinant GH3 enzymes produced IAA conjugates with several amino acids, based on thin layer chromatography. The identity of the Ala, Asp, Phe, and Trp conjugates was verified by gas chromatography–mass spectrometry. Insertional mutations in GH3.1, GH3.2, GH3.5, and GH3.17 resulted in modestly increased sensitivity to IAA in seedling root. Overexpression of GH3.6 in the activation-tagged mutant dfl1-D did not significantly alter IAA level but resulted in 3.2- and 4.5-fold more IAA-Asp than in wild-type seedlings and mature leaves, respectively. In addition to IAA, dfl1-D was less sensitive to indole-3-butyric acid and naphthaleneacetic acid, consistent with the fact that GH3.6 was active on each of these auxins. By contrast, GH3.6 and the other five enzymes tested were inactive on halogenated auxins, and dfl1-D was not resistant to these. This evidence establishes that several GH3 genes encode IAA-amido synthetases, which help to maintain auxin homeostasis by conjugating excess IAA to amino acids.
Genetic Analysis Reveals Domain Interactions of Arabidopsis Hsp100/ClpB and Cooperation with the Small Heat Shock Protein Chaperone System
Authors: Lee Ung , Wie Chris , Escobar Mindy , Williams Ben , Hong Suk-Whan , Vierling Elizabeth 
Published: January 2005

AbstractWe have defined amino acids important for function of the Arabidopsis thaliana Hsp100/ClpB chaperone (AtHsp101) in acquired thermotolerance by isolating recessive, loss-of-function mutations and a novel semidominant, gain-of-function allele [hot1-4 (A499T)]. The hot1-4 allele is unusual in that it not only fails to develop thermotolerance to 45°C after acclimation at 38°C, but also is sensitive to 38°C, which is a permissive temperature for wild-type and loss-of-function mutants. hot1-4 lies between nucleotide binding domain 1 (NBD1) and NBD2 in a coiled-coil domain that is characteristic of the Hsp100/ClpB proteins. We then isolated two classes of intragenic suppressor mutations of hot1-4: loss-of-function mutations (Class 1) that eliminated the 38°C sensitivity, but did not restore thermotolerance function to hot1-4, and Class 2 suppressors that restored acquired thermotolerance function to hot1-4. Location of the hot1-4 Class 2 suppressors supports a functional link between the coiled-coil domain and both NBD1 and the axial channel of the Hsp100/ClpB hexamer. In addition, the strongest Class 2 suppressors restored solubility of aggregated small heat shock proteins (sHsps) after heat stress, revealing genetic interaction of the Hsp100/ClpB and sHsp chaperone systems. These results also demonstrate that quantitative phenotypes can be used for in vivo genetic dissection of protein mechanism in Arabidopsis.
PlusandMinusSexual Agglutinins fromChlamydomonas reinhardtii
Authors: Ferris Patrick J. , Waffenschmidt Sabine , Umen James G. , Lin Huawen , Lee Jae-Hyeok , Ishida Koichi , Kubo Takeaki , Lau Jeffrey , Goodenough Ursula W. 
Published: January 2005

AbstractGametes of the unicellular green alga Chlamydomonas reinhardtii undergo sexual adhesion via enormous chimeric Hyp-rich glycoproteins (HRGPs), the plus and minus sexual agglutinins, that are displayed on their flagellar membrane surfaces. We have previously purified the agglutinins and analyzed their structural organization using electron microscopy. We report here the cloning and sequencing of the Sag1 and Sad1 genes that encode the two agglutinins and relate their derived amino acid sequences and predicted secondary structure to the morphology of the purified proteins. Both agglutinin proteins are organized into three distinct domains: a head, a shaft in a polyproline II configuration, and an N-terminal domain. The plus and minus heads are related in overall organization but poorly conserved in sequence except for two regions of predicted hydrophobic α-helix. The shafts contain numerous repeats of the PPSPX motif previously identified in Gp1, a cell wall HRGP. We propose that the head domains engage in autolectin associations with the distal termini of their own shafts and suggest ways that adhesion may involve head–head interactions, exolectin interactions between the heads and shafts of opposite type, and antiparallel shaft–shaft interactions mediated by carbohydrates displayed in polyproline II configurations.
Dissection of Arabidopsis ADP-RIBOSYLATION FACTOR 1 Function in Epidermal Cell Polarity
Authors: Xu Jian , Scheres Ben 
Published: January 2005

AbstractVesicle trafficking is essential for the generation of asymmetries, which are central to multicellular development. Core components of the vesicle transport machinery, such as ADP-ribosylation factor (ARF) GTPases, have been studied primarily at the single-cell level. Here, we analyze developmental functions of the ARF1 subclass of the Arabidopsis thaliana multigene ARF family. Six virtually identical ARF1 genes are ubiquitously expressed, and single loss-of-function mutants in these genes reveal no obvious developmental phenotypes. Fluorescence colocalization studies reveal that ARF1 is localized to the Golgi apparatus and endocytic organelles in both onion (Allium cepa) and Arabidopsis cells. Apical-basal polarity of epidermal cells, reflected by the position of root hair outgrowth, is affected when ARF1 mutants are expressed at early stages of cell differentiation but after they exit mitosis. Genetic interactions during root hair tip growth and localization suggest that the ROP2 protein is a target of ARF1 action, but its localization is slowly affected upon ARF1 manipulation when compared with that of Golgi and endocytic markers. Localization of a second potential target of ARF1 action, PIN2, is also affected with slow kinetics. Although extreme redundancy precludes conventional genetic dissection of ARF1 functions, our approach separates different ARF1 downstream networks involved in local and specific aspects of cell polarity.