bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of structure and scaling behavior of chemically unfolded β‐casein by means of small‐angle neutron scattering
Authors: Aschi Adel , Gharbi Abdelhafidh , Daoud Mohamed , Douillard Roger , Calmettes Patrick 
Published: December 2006

AbstractStructures of β‐casein formed in water with various concentrations of guanidine hydrochloride (GdmCl) were studied by small‐angle neutron scattering (SANS). A transition in structure and properties of the protein seems to occur around a GdmCl concentration of 1.2 mol L−1. The data are interpreted assuming that the protein molecules behave like multi‐block copolymers with alternating hydrophilic and hydrophobic sequences. Below the transition, the protein structure is still native and has a fractal dimension larger than that beyond the transition where the β‐casein has the feature of a three‐dimensional excluded‐volume coil. A possible interpretation of these results is that the presence of salt increases the value of the critical micelle concentration. This allows a comparison of the structure of β‐casein and synthetic macromolecules. We find that, although the protein is short, excluded‐volume interactions between monomers are present, and that the structure of β‐casein is very similar to what was found in dilute solutions of linear polymers in a good solvent. Thus, it is reasonable to assume that above the critical salt concentration, the protein is completely isolated, whereas below, some structure remains present. Copyright © 2006 Society of Chemical Industry
Luminescent supramolecular polymers: Cd2+‐directed polymerization and properties
Authors: Chen Xuegang , Ma Liang , Cheng Yanxiang , Xie Zhiyuan , Wang Lixiang 
Published: December 2006

AbstractA family of supramolecular polymers was prepared via Cd2+‐directed self‐assembly polymerization of bis(2,2′:6′,2″‐terpyridine)‐based ligand monomers, using oligofluorenes and triphenylamine as bridges under mild conditions. The polymers were fully characterized using thermogravimetric analysis, inherent viscosity, electrochemical measurements, UV‐visible spectroscopy, photoluminescence (PL) and electroluminescence (EL). Polymers with oligofluorenes as spacers exhibited blue emission (434–442 nm) in dimethyl acetamide (DMAc) solution, while polymers with triphenylamine as spacer presented an emission peak at 494 nm in DMAc solution. Complexation polymerization of bis(2,2′:6′,2″‐terpyridine)‐based ligand monomers with cadmium(II) improved fluorescence quantum yields dramatically, and the film PL quantum yields of these polymers were about 0.38–0.54. Single‐layer light‐emitting diodes were fabricated with the configuration indium tin oxide (ITO)/polymer/Ca/Al; the EL showed green emission and the onset voltages of the devices were 8–11 V. Copyright © 2006 Society of Chemical Industry
Multidimensional analysis of the insoluble sub‐proteome of Oceanobacillus iheyensis HTE831, an alkaliphilic and halotolerant deep‐sea bacterium isolated from the Iheya ridge
Authors: Graham Robert L. J. , Pollock Catherine E. , O'Loughlin S. Naomi , Ternan Nigel G. , Weatherly D. Brent , Tarleton Rick L. , McMullan Geoff 
Published: December 2006

AbstractWe report the first proteomic analysis of the insoluble sub‐proteome of the alkaliphilic and halotolerant deep‐sea bacterium Oceanobacillus iheyensis HTE831. A multidimensional gel‐based and gel‐free analysis was utilised and a total of 4352 peptides were initially identified by automated MS/MS identification software. Automated curation of this list using PROVALT reduced our peptide list to 467 uniquely identified peptides that resulted in the positive identification of 153 proteins. These identified proteins were functionally classified and physiochemically characterised. Of 26 proteins identified as hypothetical conserved, we have assigned function to all but four. A total of 41 proteins were predicted to possess signal peptides. In silico investigation of these proteins allowed us to identify three of the five bacterial classes of signal peptide, namely: (i) twin‐arginine translocation; (ii) Sec‐type and (iii) lipoprotein transport. Our proteomic strategy has also allowed us to identify, at neutral pH, a number of proteins described previously as belonging to two putative transport systems believed to be of importance in the alkaliphilic adaptation of O. iheyensis HTE831.
Novel, environmentally friendly crosslinking system of an epoxy using an amino acid: Tryptophan‐cured diglycidyl ether of bisphenol A epoxy
Authors: Li Yi , Xiao Fei , Wong C. P. 
Published: December 2006

AbstractTryptophan, an amino acid, has been used as a novel, environmentally friendly curing agent instead of toxic curing agents to crosslink the diglycidyl ether of bisphenol A (DGEBA) epoxy resin. The curing reaction of tryptophan/DGEBA mixtures of different ratios and the effect of the imidazole catalyst on the reaction have been evaluated. The optimum reaction ratio of DGEBA to tryptophan has been determined to be 3:1 with 1 wt % catalyst, and the curing mechanism of the novel reaction system has been studied and elucidated. In situ Fourier transform infrared spectra indicate that with the extraction of a hydrogen from NH3+ in zwitterions from tryptophan, the formed nucleophilic primary amine and carboxylate anions of the tryptophan can readily participate in the ring‐opening reaction with epoxy. The secondary amine, formed from the primary amine, can further participate in the ring‐opening reaction with epoxy and form the crosslinked network. The crosslinked structure exhibits a reasonably high glass‐transition temperature and thermal stability. A catalyst‐initiated chain reaction mechanism is proposed for the curing reaction of the epoxy with zwitterion amino acid hardeners. The replacement of toxic curing agents with this novel, environmentally friendly curing agent is an important step toward a next‐generation green electronics industry. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 181–190, 2007
Reversible addition‐fragmentation chain transfer polymerization of methacrylates containing hole‐ or electron‐transporting groups
Authors: Zhao Ping , Ling Qi‐Dan , Wang Wei‐Zhi , Ru Jie , Li Sheng‐Biao , Huang Wei 
Published: December 2006

AbstractThe controlled/living radical polymerization of 2‐(N‐carbazolyl)ethyl methacrylate (CzEMA) and 4‐(5‐(4‐tert‐butylphenyl‐1,3,4‐oxadiazol‐2‐yl)phenyl) methacrylate (t‐Bu‐OxaMA) via reversible addition‐fragmentation chain transfer polymerization has been studied. Functional polymers with hole‐ or electron‐transfer ability were synthesized with cumyl dithiobenzoate as a chain transfer agent (CTA) and AIBN as an initiator in a benzene solution. Good control of the polymerization was confirmed by the linear increase in the molecular weight (MW) with the conversion. The dependence of MW and polydispersity index (PDI) of the resulting polymers on the molar ratio of monomer to CTA, monomer concentration, and molar ratio of CTA to initiator has also been investigated. The MW and PDI of the resulting polymers were well controlled as being revealed by GPC measurements. The resulting polymers were further characterized by NMR, UV‐vis spectroscopy, and cyclic voltammetry. The polymers functionalized with carbazole group or 1,3,4‐oxadiazole group exhibited good thermal stability, with an onset decomposition temperature of about 305 and 323 °C, respectively, as determined by thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 242–252, 2007
In pursuit of B‐cell synovial autoantigens in rheumatoid arthritis: Confirmation of citrullinated fibrinogen, detection of vimentin, and introducing carbonic anhydrase as a possible new synovial autoantigen
Authors: Tilleman Kelly , Union Ann , Cantaert Tineke , De Keyser Saskia , Daniels Annick , Elewaut Dirk , De Keyser Filip , Deforce Dieter 
Published: December 2006

AbstractWe aimed to investigate potential synovial autoantigens in rheumatoid arthritis (RA) that could trigger the induction of B‐cell autoantibodies. Total protein extract of synovial tissue obtained from seven RA patients was pooled and separated by 1‐DE and 2‐DE. The corresponding blots were probed with sera from RA (n = 30) and disease control samples (n = 30). Protein spots showing a sensitivity of >15% were identified by MS. 1‐D immunoblots revealed one protein band with a specificity in RA of 100%, a sensitivity of 43%, which was identified as fibrinogen β chain. 2‐D analysis revealed the subunits of fibrinogen, especially the β and γ chain, as the most prominent synovial autoantigens. We also identified vimentin, the Sa‐antigen and carbonic anhydrase I as a potentially new synovial autoantigen. The protein patterns of these immunoreactive spots were observed as trains. The spots showing the highest autoimmune reactivity occurred at the acidic side of these trains and were recognized by anticitrullinated protein/peptide antibodies positive RA sera. Antimodified citrulline staining of these patterns confirmed protein citrullination. Therefore, PTMs such as citrullination due to alterations of peptidylarginine deiminase activity or generation of RA‐specific epitopes, should be considered as a trigger in tolerance break.
A catalogue of proteins released by colorectal cancer cells in vitro as an alternative source for biomarker discovery
Authors: Diehl Hanna C. , Stühler Kai , Klein‐Scory Susanne , Volmer Martin W. , Schöneck Anna , Bieling Cornelia , Schmiegel Wolff , Meyer Helmut E. , Schwarte‐Waldhoff Irmgard 
Published: December 2006

AbstractImproved methods for the early diagnosis of colorectal cancer by way of sensitive and specific tumour markers are highly desirable. Therefore, efficient strategies for biomarker discovery are urgently needed. Here we present an approach that is based on the direct experimental access to proteins released by SW620 human colorectal cancer cells in vitro. A 2‐D map and a catalogue of this subproteome – here termed the secretome – were established comprising more than 320 identified proteins which translate into approximately 220 distinct genes. As the majority of the secretome constituents were nominally cellular proteins, we directly compared the secretome and the total proteome by 2‐D‐DIGE analysis. We provide evidence that unspecific release through cell death, classical secretion, ectodomain shedding, and exosomal release contribute to the secretome in vitro, presumably reflecting the mechanisms in vivo which lead to the occurrence of tumour‐specific proteins in the circulation. These data together with the fact that the SW620 secretome catalogue, as presented here, does comprise a large number of known and novel biomarker candidates, validates our approach to isolate and characterize the tumour cell secretome in vitro as a rich source for tumour biomarkers.
Pressure behaviour of the UV and green emission bands in ZnO micro‐rods
Authors: Li G. H. , Su F. H. , Wang W. J. , Ding K. , Chen W. , Liu Y. F. , Joly A. G. 
Published: December 2006

AbstractThe pressure behavior of the ultraviolet (UV) and green emission bands in ZnO tetrapod‐like micro‐rods has been investigated at 300 and 70 K, respectively. The pressure coefficient of the UV band at 300 K is 24.5 meV/GPa, consistent with that of the band gap of bulk ZnO. However, the pressure coefficient of the green band is 25 meV/GPa, far larger than previous literature reports. The green band in this work originates from Cu‐related emission, as confirmed by the fine structure observed in the spectra at 10 K. The pressure coefficients of four phonon replicas of the free exciton emission (FX) at 70 K are 21.0, 20.2, 19.8, and 19.3 meV/GPa, respectively. The energy shift rate of the FX emission and the LO phonon energies is then determined to be 21.4 and 0.55 meV/GPa. The pressure coefficient of the neutral donor bound exciton (D0X) transition is 20.5 meV/GPa, only 4% smaller than that of FX. This confirms that the D0X emission corresponds to excitons bound to neutral shallow donors. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain profile of the wall of semiconductor microtubes: A micro‐Raman study
Authors: Bernardi A. , Lacharmoise P. D. , Goñi A. R. , Alonso M. I. , Vaccaro P. O. , Saito N. 
Published: December 2006

AbstractWe have investigated three‐dimensional nanostructures consisting of microtubes fabricated by rolling‐up III–V semiconductor multilayers. Through micro‐Raman spectroscopy we were able to derive the depth profile of residual strain in the microtubes by monitoring the phonon shifts experienced by different layers buried inside the tube wall. By this procedure we were able to obtain the strain components at different depths moving from the outer to the inner surface of the tube wall. We compared them with the strain distribution calculated by elastic modeling, gaining insight into the strain relaxation processes that produce the final local nanostructure of semiconductor microtubes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Force field modeling of conformational energies: Importance of multipole moments and intramolecular polarization
Authors: Rasmussen Thomas D. , Ren Pengyu , Ponder Jay W. , Jensen Frank 
Published: December 2006

AbstractThe ability of force fields to reproduce relative conformational energies for seven molecules is probed. The correlation against LMP2/cc‐pVTZ results for standard force field employing fixed partial charges deteriorates as the molecules become more polar. Inclusion of multipole moments and intramolecular polarization can improve the correlation, and both contributions are of similar importance. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Toll like receptors and viruses
Authors: Finberg Robert W. , Wang Jennifer P. , Kurt‐Jones Evelyn A. 
Published: December 2006

AbstractToll like receptors (TLRs) are ‘pattern recognition proteins’ that discriminate between self and non‐self. They interact with products of infectious agents to activate cells of the innate immune system and also stimulate the adaptive immune system. Intracellular and extracellular TLRs recognise a wide range of viruses leading to the production of different cytokines. In this paper, we summarise the types of TLRs that recognise viruses, the cytokines produced, the specific cell types involved and the activation pathways that have been characterised. We also provide an overview of the viruses demonstrated to interact with TLRs. A greater understanding of relationships between viruses or viral products and TLRs should improve understanding of pathogenesis and lead to the development of new anti‐viral therapies. Copyright © 2006 John Wiley & Sons, Ltd.
The component triglycerides of palm‐kernel oil
Authors: Bezard Jean A. 
Published: December 2006

AbstractTriglycerides of palm‐kernel oil were fractionated by gas liquid chromatography into 13 groups based on their carbon number of 30 to 54. These groups represent 99.9% of the total glyceride content. The proportion of triglyceride types in each group was calculated from the component fatty acids. These groups are defined by the nature of their constituent fatty acids but the position of the acids on glycerol is unknown. These 87 types, 24 of which are given in detail, were found. The two major components are trilaurin (19.8%) and dilauromyristin (14.1%). Only 18 types, occurring in an amount greater than 1%, together represent 80% of the total glycerides. Comparison of the glyceride content with that of coconut oil revealed many similarities between the two oils.
Diesters of diols in wheat leaf wax
Authors: Tulloch A. P. 
Published: December 2006

AbstractDiesters have been isolated from the leaf wax of spring wheat,Triticum aestivum, L. (Selkirk variety) by chromatography. The diesters, which form 3% of the wax and which were shown by gas liquid chromatography to be a mixture of C51−C60 esters, consist largely oftrans 2‐docosenoic andtrans 2‐tetracosenoic acid esters of 1,9‐nonanediol, 1,10‐decanediol, 1,11‐undecanediol and 1,12‐dodecanediol. The structures of the components were confirmed by synthesis.
Resistance to the effect of phospholipase A2 of the biliary phospholipids during incubation of bile
Authors: Boucrot P. , Clement J. R. 
Published: December 2006

AbstractMixtures of fresh bile of the rat and of isolated hepatic phospholipids (one or the other of these components having been labeled with3H oleic acid) were incubated either with heated rat pancreatic juice, at 37 C during periods of 1 and 3 hr, or with snake venom, at 25 C during periods of 17 and 36 hr, as sources of phospholipase A2. After incubation, tritiated free oleic acid was measured since this acid was in the 2 position of both phospholipidic substrates. With heated pancreatic juice, no significant enzymatic hydrolysis of the bile phospholipids occured, but isolated hepatic phospholipids were readily attacked. With snake venom, the whole isolated hepatic phospholipids were very strongly hydrolyzed while biliary phospholipids were hydrolyzed to a much lesser extent.
Effect of soluble and membrane proteins upon diethyl ether extraction of aqueous phospholipid dispersions
Authors: Parenti‐Castelli G. , Bertoli E. , Sechi A. M. , Silvestrini M. G. , Lenaz G. 
Published: December 2006

AbstractThe effect of proteins upon diethyl ether extraction of phospholipids from aqueous dispersions has been investigated as a model for elucidating lipid‐protein interactions in the more complex membrane systems. Mixed phospholipids having a net anionic charge or purified lecithin (a zwitterion) are extracted from water dispersions into ether only after addition of salts. Basic proteins (lysozyme and cytochromec), by ionically binding phospholipids, allow extraction. Phospholipids are extracted together with the proteins in the form of neutralized lipid‐protein complexes. On the other hand, lipid depleted mitochondria (a hydrophobic protein residue after acetone extraction of mitochondria), after reconstitution with phospholipids, do not allow phospholipid extraction unless salts or basic proteins also are added to the system. This observation indicates that, in reconstituted membranes, the phospholipids are largely in the bilayer form with the polar heads still charged and susceptible to ether extraction only after neutralization with salts or basic proteins.
Acyl specificity in glyceride synthesis by lactating rat mammary gland
Authors: Tanioka Hiroaki , Lin Chu Yuan , Smith Stuart , Abraham S. 
Published: December 2006

AbstractWe have investigated the possibility that the nonrandom association of fatty acids in rat milk triglycerides results from specificity of the acyl transferases in the glycerolphosphate pathway. Subcellular fractionation of lactating rat mammary gland revealed that the microsomal fraction was the most active in acylation of 3‐sn‐[U‐14C] glycerolphosphate with various acyl‐CoA's. The major products were diacylglycerolphosphate and diglyceride; no monoacylglycerolphosphate was detected. Maximum rate of acylation occurred at or below the critical micelle concentration for each acyl‐CoA, indicating that only the monomeric substrate molecules were acceptable by the enzyme system. The observed acyl specificity, 16∶0>18∶0≏14∶0>12∶0>10∶0>8∶0 is consistent with the concept that, in general, milk triglycerides are synthesized by insertion of a short or medium chain fatty acid into a long chain diglyceride.
Bis‐(monoacylglyceryl) phosphate and acyl phosphatidylglycerol isolated from human livers of lipidosis induced by 4,4′‐diethylaminoethoxyhexesterol
Authors: Kasama Kazuo , Yoshida Katsumi , Takeda Susumu , Akeda Shozo , Kawai Kazuo 
Published: December 2006

AbstractBis‐(monoacylglyceryl) phosphate and acyl phosphatidylglycerol were isolated from the liver of two patients with lipidosis induced by 4,4′‐diethylaminoethoxyhexesterol. Identification was based upon the results of alkaline hydrolysis, acetolysis, IR spectrometry, and upon the determination of molar ratio of phosphorus‐glycerol‐ester. The contents of the bis‐(monoacylglyceryl) phosphate were 10 and 16% total phospholipid phosphorus in them. The bis‐(monoacylglyceryl) phosphate contained mainly docosahexaenoic (42%), oleic (29%), and linoleic acid (14%) and had the hemolytic activity of ca. one‐eighth lysolecithin from egg yolk. Acidic lipids from the liver also were found to contain a lipid which is less polar than bis‐(monoacylglyceryl) phosphate. The results of lipid analysis showed that the lipid possessed the structure of an acyl phosphatidylglycerol, and its content was ca. 2% total phospholipid phosphorus. Accumulation of 4,4′‐diethylaminoethoxyhexesterol and its derivatives was found in clinical cases by thin layer chromatography and IR spectrometry. This fact suggested that human liver has an ability to metabolize the drug.
Occurrence ofcis‐5,cis‐9‐Hexacosadienoic andcis‐5,cis‐9,cis‐19‐Hexacosatrienoic acids in the marine spongeMicrociona prolifera
Authors: Jefferts Elaine , Morales Reginald W. , Litchfield Carter 
Published: December 2006

AbstractFatty acid analysis of the total lipids from the marine spongeMicrociona prolifera by gas liquid chromatography on an EGSS‐X column revealed two major peaks with equivalent chain length values of 27.08 and 27.74. Each of these components was isolated as a separate band by thin layer chromatography on AgNO3‐silicic acid. Characterization of the two unknowns by IR spectroscopy, NMR, hydrogenation, and gas liquid chromatography revealed that the unknown acids weren‐26∶2 andn‐26∶3 containing only nonmethylene interruptedcis‐double bonds. Reductive ozonolysis identified the 26∶2 ascis‐5,cis‐9‐hexacosadienoic acid and the 26∶3 ascis‐5,cis‐9,cis‐19‐hexacosatrienoic acid. Analysis of the fatty acid composition ofMicrociona total lipids showed 14% 26∶2 and 31% 36∶3. The neutral lipids, phosphatidylethanomaline, and phosphatidylserine all contained >41% C26 acids; but only 4% C26 was present in the phosphatidylcholine.
Sequential gas chromatographic procedure for microanalysis of monoenoic double bond position in hydrogenated oils
Authors: Emken E. A. , Dutton H. J. 
Published: December 2006

AbstractQuantitative cleavage of epoxyoctadecanoates with periodic acid (HIO4) has been demonstrated and the technique incorporated into an all gas chromatographic system for detailed lipid analysis. The overall procedure involves three sequential gas chromatographic separations interspersed by two microreactions. By this procedure, a complete analysis forcis‐ andtrans‐geometric isomers corresponding to each positional octadecenoate isomer is obtained. Total sample requirements are less than 10 mg, and the elapsed analysis time/sample is less than 10 hr. In this all gas chromatographic procedure, a lipid methyl ester sample is first separated by preparative gas chromatography, and the monoene fraction is collected and epoxidized. Next, the epoxidized sample is separated by gas chromatography intocis‐ andtrans‐epoxyoctadecanoate fractions. These epoxyoctadecanoate fractions are collected and cleaved with HIO4 into aldehyde and aldehyde‐ester fragments, which are quantitatively analyzed by gas chromatography. The double bond positions are determined from the aldehyde and aldehyde‐ester cleavage data, which are stored and processed by a computerized on‐line gas chromatographic data acquisition system. The procedure was tested on pure octadecenoate isomers, standard mixtures, and commercially hydrogenated vegetable oils. Analyses of hydrogenated vegetable oils are compared with data acquired by reverse‐phase and argentation chromatography followed by reductive ozonolysis.
Age dependent structural changes in the diol esters of uropygial glands of chicken
Authors: Kolattukudy P. E. , Sawaya W. N. 
Published: December 2006

AbstractThe chain lengths and diastereoisomer composition of alkane‐2, 3‐diol diesters of the uropygial glands of chicken changed significantly as the birds became physiologically mature. The C24 diol decreased, and C22 and C23 diols increased. Threo isomer content of the diols decreased. In the acyl portion, the shorter (C12−C15) acids decreased, and the longer (C17−C20) acids increased.