bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase Behavior and Thermal Properties for Binary Blends of Bacterial Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)s with Narrow‐Comonomer‐Unit Compositional Distribution
Authors: Feng Lidan , Watanabe Takumi , He Yong , Wang Yi , Kichise Tomoyasu , Fukuchi Takeshi , Chen Guo‐Qiang , Doi Yoshiharu , Inoue Yoshio 
Published: June 2003

AbstractThe miscibility and the effect of compositional distribution on physical properties were investigated for binary blends of biosynthesized poly(3‐hydroxybutyrate) [P(3HB)] and comonomer compositionally fractionated poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)s [P(3HB‐co‐3HH)] with narrow compositional distribution. Biosynthesized P(3HB‐co‐3HH) samples were compositionally fractionated using solvent (chloroform)/nonsolvent (n‐heptane) mixtures. The binary blends of fractionated P(3HB‐co‐3HH)s with different 3HH unit content were prepared by casting from solution in chloroform. The miscibility and the thermal properties of these blends were analyzed by differential scanning calorimetry (DSC). It was found that the two components are miscible in the amorphous phase when the difference in 3HH unit content between the two component polymers of these blends is less than 20 mol‐%, subsequently they are immiscible when the difference is larger than 30 mol‐%. By comparing the thermal properties of the binary blends of fractions, with those for the fractions themselves, and with those for the bacterially as‐produced unfractionated copolyesters, the effects of compositional distribution on the properties of copolyesters were discussed.Glass transition temperatures of blends PHB/H10, H10/H20, and PHB/H20 versus total 3HH unit content in the blends. The solid lines are the best fits of the experimental results of the P(3HB‐co‐3HH) fractions with narrow compositional distribution.magnified imageGlass transition temperatures of blends PHB/H10, H10/H20, and PHB/H20 versus total 3HH unit content in the blends. The solid lines are the best fits of the experimental results of the P(3HB‐co‐3HH) fractions with narrow compositional distribution.
Antioxidant Activity of Graft Chitosan Derivatives
Authors: Sun Tao , Xie Wenming , Xu Peixin 
Published: June 2003

AbstractGraft chitosan derivatives (CMCTS‐g‐MAAS and CMCTS‐g‐AAS) were prepared by the graft copolymerization of methacrylic acid sodium (MAAS) and acrylic acid sodium (AAS) onto the etherification product of chitosan‐carboxymethyl chitosan (CMCTS). Their antioxidant activity was estimated as superoxide anion scavengers by chemiluminescence techniques. The derivatives with low grafting percentages have a relatively low 50% inhibition concentration (IC50), which could be related to the fact that they have different contents of hydroxyl and amino groups in the polymer chains.Superoxide radical scavenging activity of CMCTS‐g‐MAAS.magnified imageSuperoxide radical scavenging activity of CMCTS‐g‐MAAS.
Hydrolytic and Thermal Degradation of Random Copolyesters of ε‐Caprolactone and 2‐Oxepane‐1,5‐dione
Authors: Dwan'Isa Jean‐Pierre Latere , Lecomte Philippe , Dubois Philippe , Jérôme Robert 
Published: June 2003

AbstractThe hydrolytic and thermal stability of random copolyesters of ε‐caprolactone (ε‐CL) and ca. 30 mol‐% 2‐oxepane‐1,5‐dione (OPD) have been investigated. Compared with poly(ε‐caprolactone) (PCL) of a comparable molecular weight, the hydrolytic degradation of the copolyester is faster in a phosphate buffer (pH = 7.4) at 37 °C as confirmed by the time dependence of water absorption, weight loss, melting temperature, and molecular weight. This difference is a result of the higher hydrophilicity imparted to the copolyester by the ketone of the OPD units. The thermal degradation has been studied by thermogravimetric analysis (TGA), 1H NMR spectroscopy, and size exclusion chromatography (SEC). The activation energy of the thermal degradation under nitrogen has been found to be lower for the copolyesters than for PCL, which indicates that the OPD co‐units have a deleterious effect on the thermal stability of PCL. The thermal degradation primarily occurs by pyrolysis of the ester functions.Pyrolysis of the ester function of the ε‐CL/OPD diad.magnified imagePyrolysis of the ester function of the ε‐CL/OPD diad.
Thermo‐Responsive and Emulsifying Properties of Poly(N‐vinylcaprolactam) Based Graft Copolymers
Authors: Verbrugghe Sam , Bernaerts Katrien , Du Prez Filip E. 
Published: June 2003

AbstractThermo‐responsive graft copolymers have been synthesized based on a poly(N‐vinylcaprolactam) (PVCL) backbone and either hydrophilic poly(ethylene oxide) (PEO) or hydrophobic poly(tetrahydrofuran) (PTHF) side chains. The phase separation behavior of the graft polymers in water was studied by transmittance measurements and compared to that of the corresponding swollen segmented polymer networks and aqueous solutions of both polymers. The influence of the concentration and length of the grafts on the cloud point temperature (TCP) has been demonstrated. PVCL‐g‐PTHF copolymers have been synthesized by using the macromonomer technique, i.e. the radical copolymerization of VCL with a PTHF macromonomer. A special feature of these amphiphilic graft copolymers is their ability to stabilize aqueous emulsions below the TCP and to suddenly break them above the TCP. PVCL‐g‐PEO copolymers were prepared by a grafting onto method. First, succinimide groups were introduced in the backbone, to which amino terminated PEO chains were grafted in the second step. This leads to di‐hydrophilic copolymers that become amphiphilic after heating their aqueous solutions above the TCP.magnified image
Donaldson–Friedman construction and deformations of a triple of compact complex spaces, II
Authors: Honda Nobuhiro 
Published: June 2003

AbstractIn a previous paper of the same title the author gave a generalization of the constrution of Donaldson–Friedman, to prove the existence of twistor spaces of nCP2 with a special kind of divisors. In the present paper, we consider its equivariant version. When n = 3, this gives another proof of the existence of degenerate double solid with C*–action, and we show that the branch quartic surface is birational to an elliptic ruled surface. In case n ≥ 4, this yields new Moishezon twistor spaces with C*–action, which is shown to be the most degenerate ones among twistor spaces studied by Campana and Kreußler.
Integral representation for exponentially bounded negative–definite functions on hypergroups
Authors: Nasr–Isfahani R. 
Published: June 2003

AbstractThe author has recently shown that a Bochner type theorem obtained by Bloom and Ressel for exponentially bounded positive–definite functions on second countable commutative hypergroups is valid for all commutative hypergroups X. Here an application of this result is made to give an integral representation for exponentially bounded negative–definite functions on X.
On the axiomatic definition of real JB*–triples
Authors: Peralta Antonio M. 
Published: June 2003

AbstractIn the last twenty years, a theory of real Jordan triples has been developed. In 1994 T. Dang and B. Russo introduced the concept of J*B–triple. These J*B–triples include real C*–algebras and complex JB*–triples. However, concerning J*B–triples, an important problem was left open. Indeed, the question was whether the complexification of a J*B–triple is a complex JB*–triple in some norm extending the original norm. T. Dang and B. Russo solved this problem for commutative J*B–triples.In this paper we characterize those J*B–triples with a unitary element whose complexifications are complex JB*–triples in some norm extending the original one. We actually find a necessary and sufficient new axiom to characterize those J*B–triples with a unitary element which are J*B–algebras in the sense of [1] or real JB*–triples in the sense of [4].
Polyelectrolyte Multilayers on Weak Polyelectrolyte Brushes
Authors: Zhang Haining , Rühe Jürgen 
Published: June 2003

AbstractThe interaction of surface‐attached weak polyelectrolyte brushes, grown directly from the surface of a solid substrate by surface‐initiated polymerization, with weak polyelectrolyte molecules in solution is studied. In addition, the formation of PEL multilayers onto such brush substrates is investigated. A strong template effect is observed and the thickness of each adsorbed layer is closely related to the thickness of the initial brush. Thus monolayers of more than 100 nm can be adsorbed in one single dipping cycle.Layer thickness of PEI layers adsorbed to PMAA brushes as a function of the thickness of the surface‐attached monolayer. The solid line represents a case in which the PEI layer has exactly the same thickness as the brush monolayer.magnified imageLayer thickness of PEI layers adsorbed to PMAA brushes as a function of the thickness of the surface‐attached monolayer. The solid line represents a case in which the PEI layer has exactly the same thickness as the brush monolayer.
A New Approach to High‐Capacity Functionalized Monoliths via Post‐Synthesis Grafting
Authors: Lubbad Said , Buchmeiser Michael R. 
Published: June 2003

AbstractA new approach toward the grafting of norborn‐2‐ene derivatives onto ROMP‐based monolithic supports has been developed. Grafting yields were governed by three variables, which are the catalyst, temperature and the crosslinker used. Three different catalysts, three grafting temperatures, as well as two different crosslinkers were investigated. By optimizing all variables 4‐fold amounts of grafted monomers compared to previously reported procedures were obtained reaching values of 1.04 mmol of monomer/g monolith.Grafted monolithic supports applying the method reported here.magnified imageGrafted monolithic supports applying the method reported here.
Synthesis of Poly(methyl methacrylate) Nanosize Particles by Differential Microemulsion Polymerization
Authors: He Guangwei , Pan Qinmin , Rempel Garry L. 
Published: June 2003

AbstractPoly(methyl methacrylate) nanosize particles were synthesized by a differential microemulsion polymerization process. Sodium dodecylsulfate and ammonium persulfate were used as the surfactant and initiator, respectively. The effects of reaction conditions on the particle size have been investigated. A particle size of less than 20 nm in diameter has been achieved with surfactant/monomer and surfactant/water weight ratios of 1:18 and 1:120, i.e. much milder conditions than those previously reported in the literature.TEM image of nanoparticles prepared via differential microemulsion polymerization.magnified imageTEM image of nanoparticles prepared via differential microemulsion polymerization.
Tandem mass spectrometry in the study of fatty acids, bile acids, and steroids
Authors: Griffiths William J. 
Published: June 2003

Abstract

I.
Introduction
82

II.
Collision‐Energy Effects and Charge‐Remote Fragmentation
83

III.
Fatty Acids and Related Lipids
85

A.  Saturated and Unsaturated Fatty Acids
85

B.  Hydroxy‐Polyunsaturated Fatty Acids and Eicosanoids
89

C.  Derivatization of Fatty Acids for FAB and ES Analysis
90

D.  Fatty Alcohols and Aldehydes
94

IV.
Complex Lipids
96

A.  Phospholipids
97

B.  Triacylglycerols
106

V.
Bile Acids and Conjugated Steroids
112

A.  Bile Acids
112

B.  Steroid Conjugates: Sulfates and Glucuronides
115

C.  Mechanism of Fragmentation of Bile Acids, Steroid Sulfates, and Steroid Glucuronides
126

1.  Side‐Chain Fragmentation
127

2.  Ring Fragmentation
127

3.  Sulfate Fragmentation
128

4.  Bile Acid Fragmentation
128

VI.
Neutral Steroids
128

A.  Estradiol Metabolites and Synthetic Derivatives
128

B.  Oxosteroids and Their Derivatives
131

1.  3‐Oxo‐Δ4‐Steroid 3‐Oximes
132

2.  20‐Oxosteroid and 17‐Oxosteroid Oximes
133

3.  Methyl Oximes
134

4.  Underivatized Oxosteroids
134

5.  Steroid Esters
138

6.  Girard T Hydrazone
139

VII.
Novel Derivatives of Neutral Steroids
140

VIII.
Conclusions
142

Acknowledgments

143

Appendix

143

A.
Abbreviations and Relevant References
143

B.
Use of the Prime
144

C.
Some Steroid Structures
145

References

145

Over the last 50 years, the mass spectrometry of lipids has evolved to become one of the most mature techniques in biomolecule analysis. Many volatile and non‐polar lipids are directly amenable to analysis by gas‐chromatography‐mass spectrometry (GC‐MS), a technique that combines the unsurpassed separation properties of gas‐chromatography with the sensitivity and selectivity of electron ionization mass spectrometry. Less volatile and/or thermally labile lipids can be analyzed by GC‐MS, following appropriate sample derivatization. However, many complex lipids are not readily analyzed by GC‐MS, and it is these molecules that are the subject of the current review. Since the early 1970s, there have been three outstanding developments in mass spectrometry that are particularly appropriate in lipid analysis; i.e., the introduction of (i) fast atom bombardment (FAB); (ii) electrospray (ES); and (iii) tandem mass spectrometry (MS/MS). The FAB and ES ionization techniques will be discussed in relation to MS/MS, and examples of their application in biochemical studies will be presented. The review will concentrate on the analysis of fatty acids, bile acids, steroid conjugates, and neutral steroids. © 2003 Wiley Periodicals, Inc., Mass Spec Rev 22:81–152, 2003; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/mas.10046
Untersuchung zur Schichtfolge eines Multilayerschichtsystems NiZn Ferrit / Si bzw. SiO2für Höchstfrequenzleiterplatten im Frequenzbereich größer 1000 MHz
Authors: Gräbner F. , Teichert G. , Knedlik Ch. , Hildenbrand S. , Romanus H. , Hungsberg A. , Koledintseva M. 
Published: June 2003

AbstractEs ist gelungen mittels des Sputterverfahrens ferritische Multilayerschichten auf HF‐Leiterplattenmaterial der Firmen Rogers (USA) und Mauritz ( Germany) abzuscheiden.Es wurde eine fast linear anwachsende Reflexionsdämpfung von 0,6 dB ab 1000 MHz bis 77000 MHz gemessen. Die theoretische Betrachtung mit einem numerischen Simulator 2DTLM zum Schichtfolgeaufbau konnte im Experiment in der Striplineanordnung bis 3800 MHZ diskutiert werden. Theoretische Simulationsergebnisse weisen auf gute Dämpfungsergebnisse bei einem Schichtaufbau mit Anordnung einer Ferritschicht am Metallabschluß hin.
Zum Korrosions‐ und Verschleißverhalten von Nickeldispersionsschichten mit Nanopartikeln
Authors: Steinhäuser S. , Lampke Th. , Wielage B. , Erler F. , Jakob C. 
Published: June 2003

AbstractDiese Arbeit berichtet über die Ergebnisse der elektrochemischen Abscheidung von Nickeldispersionsschichten mit nanoskaligen Partikeln aus einem Watts Elektrolyten. Es werden Aussagen zu erzielten Einbauraten und daraus resultierenden Gefügen und mechanischen Eigenschaften getroffen. Von besonderer Bedeutung für die Anwendung der abgeschiedenen Schichten sind deren Korrosions‐ und Verschleißverhalten. Mit Hilfe von Stromdichte‐Potenzialmessungen und optischen Untersuchungsmethoden ist das Korrosionsverhalten in Abhängigkeit von den Feststoffen und organischen Zusätzen bewertbar. Eine Steigerung der Korrosionsbeständigkeit durch nanoskalige Teilchen wurde nicht festgestellt. Sehr positiv wirken sich die inkorporierten Partikel auf das Verschleißverhalten, ermittelt im Schwingverschleißtribometer, aus.
Thermisches Bonden von Bauteilen aus mikrostrukturiertem Glas
Authors: Hecht‐Mijic St. , Harnisch A. , Hülsenberg D. , Schundau S. , Pfeifer J. , Schroeter Th. 
Published: June 2003

AbstractAn der TU Ilmenau erfolgte die Entwicklung von mikrostrukturierbaren Gläsern und von mikrostrukturierbaren Gläsern mit besonderen pH‐sensitiven Eigenschaften. Die Gläser sind über eine UV‐Lithographietechnik mikrostrukturierbar. Zum Aufbau von chemischen Sensoren ist das Fügen von derartigen Glasbauteilen erforderlich. Im Beitrag werden das thermische Bonden als ein mögliches Fügeverfahren vorgestellt und Versuchsergebnisse diskutiert. Vorteile des Verfahrens sind die stabile Verbindungsausbildung und das werkstoffkonforme Fügen ohne Zusatzstoffe.
Bioglass® coated poly(DL‐lactide) foams for tissue engineering scaffolds
Authors: Gough J. E. , Arumugam M. , Blaker J. , Boccaccini A. R. 
Published: June 2003

AbstractThe purpose of this study was to prepare poly(DL‐lactic acid) (PDLLA)/Bioglass® composites of foam‐like structure, to measure the degree of bioactivity of the composites by studying the formation of hydroxyapatite (HA) after immersion in simulated body fluid (SBF) and to test the initial attachment of human osteoblasts within the porous network. It was found that crystalline HA formed on the Bioglass® coated PDLLA foams after 7 days of immersion in SBF. HA formed also on the surfaces of non‐coated PDLLA foams, however the rate and amount of HA formation were much lower than in the composites. The rapid formation of HA on the Bioglass®/PDLLA foam surfaces confirmed the high bioactivity of these materials. Osteoblasts attached within the porous network throughout the depth of the foams. Cell density was found to be higher in the PDLLA/Bioglass® composites compared to the pure PDLLA foams. The composite foams developed here exhibit the required bioactivity to be used as scaffolds for bone tissue engineering.
Eliminating the Extinction‐Induced Reflection Enlargement in the XRD Characterisations of Textured Films
Authors: Tomov I. 
Published: June 2003

AbstractThis investigation throws additional light on the nature of secondary extinction (SE). A method is described for computing the correct integral breadth using the observed one, which is affected by SE. The method is applied for more precise measuring the integral breadths of reflections corresponding to the ideal directions of main texture components of electrodeposited silver films. Further, the effect of SE on the systematic error in integral breadth measurements is investigated in dependence on the reflectivity and pole density.
Essential tremor is not associated with α‐synuclein gene haplotypes
Authors: Pigullo Simona , Di Maria Emilio , Marchese Roberta , Bellone Emilia , Gulli Rossella , Scaglione Cesa , Battaglia Stella , Barone Paolo , Martinelli Paolo , Abbruzzese Giovanni , Ajmar Franco , Mandich Paola 
Published: June 2003

AbstractA specific allele of the NACP‐Rep1 polymorphism within the α‐synuclein promoter was found to be associated both with Parkinson's disease and essential tremor. We repeated the association study on a large series of Italian patients with essential tremor using a panel of polymorphisms within the α‐synuclein gene. Our results did not confirm the association reported previously and failed to identify a α‐synuclein specific haplotype as susceptibility factor for essential tremor. © 2003 Movement Disorder Society
Clinical features and neuroimaging of PARK7‐linked parkinsonism
Authors: Dekker Marieke , Bonifati Vincenzo , van Swieten John , Leenders Nico , Galjaard Robert‐Jan , Snijders Pieter , Horstink Marten , Heutink Peter , Oostra Ben , van Duijn Cornelia 
Published: June 2003

AbstractWe recently reported linkage to chromosome 1p36 (the PARK7‐locus) in a family with early‐onset parkinsonism. Linkage to this locus has since been confirmed in an independent data set. We describe clinical and neuroimaging features of the 4 patients in the original PARK7‐linked kindred. Age at onset of parkinsonism varied from 27 to 40 years. Clinical progression was slow, and response to dopaminergic therapy good. The clinical spectrum ranged from mild hypokinesia and rigidity, to severe parkinsonism with levodopa‐induced dyskinesias and motor fluctuation. Three of four patients with PARK7‐linked parkinsonism exhibited psychiatric disturbances. Structural neuroimaging was unremarkable, but functional imaging of the brain, carried out in 3 patients, showed significant evidence for a presynaptic dopamine deficit, and assessment of cerebral glucose metabolism, as carried out in 1 patient, showed possible cerebellar involvement. © 2003 Movement Disorder Society
Chorea as a presenting feature of variant Creutzfeldt‐Jakob disease
Authors: McKee David , Talbot Paul 
Published: June 2003

AbstractWe report on a patient with pathologically proven variant Creutzfeld‐Jakob disease in whom chorea was a presenting feature of the disease, and was unaccompanied by the typical prodrome of psychiatric disturbance or sensory symptoms. © 2003 Movement Disorder Society
Lack of effect of polymorphisms in dopamine metabolism related genes on imaging of TRODAT‐1 in striatum of asymptomatic volunteers and patients with Parkinson's disease
Authors: Lynch David R. , Mozley P. David , Sokol Set , Maas Nicole M.C. , Balcer Laura J. , Siderowf Andrew D. 
Published: June 2003

AbstractSPECT scanning using 99Tc‐TRODAT‐1, a ligand that binds to dopamine transporters, may be useful for detection of early Parkinson's disease (PD), diagnosis of presymptomatic individuals, and monitoring disease progression. Understanding whether genetic factors contribute to inter‐individual variability is crucial for interpreting imaging results in the context of disease pathophysiology. We tested whether polymorphisms in the genes for catechol‐O‐methyltransferase (COMT), monoamine‐oxidase B (MAO‐B), and the dopamine transporter (DAT) influence dopamine uptake parameters in the striatum in vivo in asymptomatic volunteers and patients with PD as measured with 99Tc‐TRODAT‐1. 99Tc‐TRODAT‐1 binding declined with age in both asymptomatic volunteers and PD patients, and depended on disease duration in PD patients. We found no significant association between COMT, MAO‐B, and DAT polymorphisms and results of 99Tc‐TRODAT‐1 testing in asymptomatic volunteers or patients with PD. In PD patients, the age of disease onset and speed of progression did not differ based on these polymorphisms. These results demonstrate that these specific genetic variations do not alter the fidelity of 99Tc‐TRODAT‐1 as a measure of dopaminergic function in asymptomatic volunteer individuals or patients with PD. © 2003 Movement Disorder Society
Marked variation in clinical presentation and age of onset in a family with a heterozygous parkin mutation
Authors: Tan Louis C. , Tanner Caroline M. , Chen Rong , Chan Piu , Farrer Matthew , Hardy John , Langston J. William 
Published: June 2003

AbstractParkin gene mutations have been detected in families with early‐onset autosomal recessive parkinsonism. We report a novel heterozygous 40 base pair deletion in exon 3 of the parkin gene that increases the susceptibility of carriers to develop parkinsonism/dystonia and manifests remarkable variability in regard to age of onset and phenotype in a single family. After identifying the new mutation in the proband of this kindred, family members were contacted and evaluated by a movement disorders specialist using standardized protocols and prospectively set diagnostic criteria. Importantly, examining physicians and family members were blinded to the genetic testing. Five affected members in two generations carried the parkin mutation. The proband and one of his brothers had disease onset at 24 years of age while another brother had disease at age 44. One exhibited multi‐focal dystonia and parkinsonism of 17 years duration, another suffered a unilateral slowly progressive parkinsonism over 13 years while the third suffered dystonia–parkinsonism of recent onset. A sibling pair in the preceding generation had mild previously undiagnosed parkinsonism. Clinicians should be aware that patients carrying a parkin gene mutation may present with dystonia–parkinsonism or very subtle parkinsonism with a markedly varied age of onset. © 2003 Movement Disorder Society
Tongue tremor in a patient with coma after electrical injury
Authors: Lin Katia , Lin Jaime , Piovesan Elcio Juliato , Germiniani Francisco M.B. , Teive Hélio A.G. , Werneck Lineu Cesar 
Published: June 2003

AbstractWe report on the case of a patient with transient tongue tremor and coma after electrical injury, probably due to a reversible brainstem dysfunction. We then reviewed the differential diagnosis of abnormal involuntary movements of the tongue as well as movement disorders related to electrocution. © 2003 Movement Disorder Society