bluuebunny/crossref_metadata_2025_split huggingface dataset:
The central residues of a T cell receptor sequence motif are key determinants of autoantigen recognition in murine experimental autoimmune encephalomyelitis
Authors: Huang Jason C. , Ober Raimund J. , Ward E. Sally 
Published: December 2004

AbstractThe autoreactive response in murine experimental autoimmune encephalomyelitis (EAE) is dominated by an oligoclonal expansion of Vβ8+ CD4+ T cells. These T cells recognize the immunodominant N‐terminal nonapeptide of myelin basic protein (MBP1–9) associated with the MHC class II molecule, I‐Au. Amongst the autoreactive cells, T cells bearing TCR containing the CDR3β motif Asp‐Ala‐Gly‐Gly‐Gly‐Tyr (DAGGGY) play a dominant role in the disease process. Here we have investigated the molecular basis for antigen recognition by a representative TCR (172.10) that contains the DAGGGY motif. The roles of the three glycines in this motif in the corresponding TCR‐peptide‐MHC interactions have been analyzed using a combination of site‐directed mutagenesis and surface plasmon resonance. Our data show that mutation of either of the first two glycines (G97, G98) to alanine results in soluble, recombinant TCR that do not bind to recombinant antigen at detectable levels. Mutation of the third glycine (G99) of the 172.10 TCR results in a substantial decrease in affinity. The importance of the triple glycines for antigen recognition provides an explanation at the molecular level for the recruitment of T cells bearing the DAGGGY motif into the responding repertoire during EAE induction.
Bis(trimethylsilyl)acetylene Complexes of Titanocenes and Zirconocenes: Their Recent Chemistry and Reactions with Lewis Acids
Authors: Rosenthal Uwe , Burlakov Vladimir V. , Arndt Perdita , Baumann Wolfgang , Spannenberg Anke , Shur Vladimir B. 
Published: December 2004

AbstractThe chemistry of the metallocene bis(trimethylsilyl)acetylene complexes [Cp2M(L)(η2‐Me3SiC2SiMe3)] [M = Ti, without L (1); M = Zr, L = THF (2a); M = Zr, L = pyridine (2b)], the pentamethylcyclopentadienyl complexes [Cp*2M(η2‐Me3SiC2SiMe3)] [M = Ti (3), Zr (4)], and the ethylenebis(tetrahydroindenyl) (ebthi) complexes rac‐[(ebthi)M(η2‐Me3SiC2SiMe3)] [M = Ti (5), Zr (6)] has been described in several reviews. A fine‐tuning of the reactions is possible by varying the Cp ligands (Cp, Cp*, ebthi), additional the co‐ligands (THF, pyridine), and/or metals (Ti, Zr), and it has been pointed out that these complexes offer a number of compelling advantages over other, similar, widely used metallocene reagents. In this microreview recent (2000−2004) examples of the chemistry of complexes 1−6 are summarized, and some special interactions with Lewis acids are described. In these reactions the metallocene cores “Cp′2Ti” and “Cp′2Zr” (Cp′ = substituted Cp ligands) are mostly formed after dissociation of the alkyne. As examples of this, a new selective zirconocene coupling route to large, functionalized macrocycles has been established from 2b and polyynes, complex 1 catalyses the first anti‐Markovnikov hydroamination of terminal alkynes, complexes 1 and 3 selectively form polynuclear titanium complexes by C−C coupling of N‐containing heterocycles, and complexes 1, 2b, 3, and 6 promote selective C−H and C−F bond‐cleavage reactions of fluorinated N‐containing heterocycles. Beside this recent chemistry, this microreview also focuses on the reactions of the above‐mentioned complexes with the Lewis acids diisobutylaluminum hydride and tris(pentafluorophenyl)borane. For example, complexes 1, 2b, and 6 react with iBu2AlH to give heterodimetallic complexes containing tetracoordinate planar carbon atoms. The titanium complex 1 reacts with B(C6F5)3 with elimination of the alkyne and gaseous hydrogen to give an electrophilic substitution of the Cp or Cp* ligand in which zwitterionic TiIII complexes are formed. The zirconium complexes 4 and 6 do not liberate hydrogen in the reaction with B(C6F5)3, although, after C−H activation of one methyl group of the Cp* or Cp part of the ebthi ligand and a B−C bond formation, zwitterionic complexes containing alkylidene groups with agostic interactions with the metal center are obtained. Complex 5 reacts with B(C6F5)3 with Si−C bond cleavage of the alkyne and formation of an alkynylboranate [Me3SiC≡CB(C6F5)3]−, which is complexed by the “rac‐(ebthi)Ti” fragment to give a zwitterionic complex. Some of the formed heterodinuclear complexes and the zwitterionic complexes are active catalysts in the ring‐opening polymerization of lactones, cyclic carbonates, and epoxides, as well as the polymerization of ethylene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A secure authentication watermarking for halftone and binary images
Authors: Kim Hae Yong , Afif Amir 
Published: December 2004

AbstractAn authentication watermark is a hidden data inserted into an image that can be used to detect any accidental or malicious alteration in the image. Many authentication‐watermarking techniques for continuous‐tone images are described in the literature, but only a quite small number of secure authentication watermarking techniques are available for binary/halftone images. This article proposes a simple solution for inserting a secure authentication watermark in binary/halftone images. It consists of choosing a set of pseudo‐random pixels in the image, clearing them, computing the message authentication code (or the digital signature) of the now‐cleared image, and inserting the resulting code into the selected random pixels. Dispersed‐dot halftone images watermarked by the proposed technique present better visual quality than do watermarked generic binary images. However, in practice, the visual degradation is hardly noticeable in either case. The proposed technique seems to be the only binary/halftone watermarking scheme that can detect even a single pixel alteration in the host image. It can be used with secret‐key or public‐key ciphers. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 147–152, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20018
GABA alters the metabolic fate of [U‐13C]glutamate in cultured cortical astrocytes
Authors: McKenna Mary C. , Sonnewald Ursula 
Published: December 2004

AbstractThe effect of γ‐aminobutyric acid (GABA) on glutamate metabolism was studied by 13C‐nuclear magnetic resonance (NMR) spectroscopy. Cerebral cortical astrocytes were incubated with 0.5 mM [U‐13C]glutamate and 5 mM glucose in the presence or absence of 0.2 mM GABA for 2 hr. 13C‐Labeled glutamate, glutamine, and aspartate were observed in cell extracts, and 13C‐labeled glutamine and lactate were present in the media. Both uniformly labeled glutamate and [1,2,3‐13C]glutamate derived from the tricarboxylic acid (TCA) cycle were present in the cells. The consumption of [U‐13C]glutamate and glucose was unchanged in the presence of GABA; however, the formation of [U‐13C]lactate and [U‐13C]aspartate from metabolism of [U‐13C]glutamate was increased in cells incubated with GABA. The total concentration of aspartate was increased to the same extent as the 13C‐labeled aspartate, suggesting increased entry of [U‐13C]glutamate into the TCA cycle to allow for the transamination of GABA. Although the concentrations of unlabeled glucose and lactate in the media were unchanged in the presence of GABA, the concentration of alanine was decreased, indicating that there was decreased transamination of the unlabeled pyruvate from glucose metabolism. The amount of [U‐13C]glutamate converted to [U‐13C]glutamine and [U‐13C]lactate was increased in the presence of GABA. However, since the overall consumption of [U‐13C]glutamate was not different, it can be concluded that the amount of [U‐13C]glutamate used for energy was decreased. This suggests that exogenous GABA could substitute for glutamate as an energy source for astrocytes. The results indicate that the presence of GABA influences the metabolic fate of both glutamate and glucose in astrocytes, suggesting that fluctuations in the concentration of GABA in normal and pathological conditions can alter the compartmentation of glial metabolism in brain. © 2004 Wiley‐Liss, Inc.
Relationship of climate and genotype to seasonal variation in the glucosinolate–myrosinase system. I. Glucosinolate content in ten cultivars of Brassica oleracea grown in fall and spring seasons
Authors: Charron Craig S , Saxton Arnold M , Sams Carl E 
Published: December 2004

AbstractTwo cultivars each of broccoli (Brassica oleracea L var italica), Brussels sprouts (B oleracea var gemmifera), cabbage (B oleracea var capitata), cauliflower (B oleracea var botrytis) and kale (B oleracea var acephala) were grown during two fall seasons and two spring seasons to determine whether significant seasonal effects on glucosinolate (GS) concentrations could be explained by mean temperature, photosynthetic photon flux (PPF) and daylength during the growing seasons. Concentrations of total GSs, indole GSs and glucoraphanin differed by genotype and season. Total GS concentrations at harvest had a negative linear but positive quadratic relationship with temperature and daylength over the 2 weeks preceding harvest and a positive linear but negative quadratic relationship with PPF over the same 2 weeks. The regression model for indole GS concentrations similarly varied with mean temperature, daylength and PPF over the 4 weeks prior to harvest. Glucoraphanin concentrations at harvest decreased linearly with mean PPF from transplanting to harvest and had a negative linear but positive quadratic relationship with daylength from transplanting to harvest. Because glucoraphanin and other GSs in cruciferous crops are important for cancer chemoprotection, climatic conditions should be considered when planning planting dates or when making breeding selections for GS concentration. Copyright © 2004 Society of Chemical Industry
Unmalted triticale cultivars as brewing adjuncts: effects of enzyme activities and composition on beer wort quality
Authors: Glatthar Jens , Heinisch Jürgen J , Senn Thomas 
Published: December 2004

AbstractThe applicability of three selected triticale cultivars (Trinidad, Lamberto, Fidelio) for use as brewing adjuncts was investigated in comparison with wheat adjunct and barley malt. Fermentable substance, crude protein and arabinoxylan levels of starchy materials were determined as well as their native potencies (amylolytic, proteolytic, pentosolytic) to solubilise and degrade grain components during mashing. Laboratory‐scale experiments were performed to evaluate the influence of the adjuncts (composition, enzyme potency) on beer wort quality by mashing mixed (1:1) grists of malt and adjunct. Barley malt was rated as the superior raw material, possessing considerably higher enzyme activities and yielding the lowest wort viscosity. Among the triticale cultivars cv Trinidad was identified as the most suitable to serve as a brewing adjunct due to its improved starch solubilisation properties and its ability to generate low wort viscosities. Compared with the potent malt enzymes, the enzyme activities of unmalted triticale (such as amylases, pentosanases and proteases) had little affect on the composition of the sweet worts. In contrast, the contents of crude protein and fermentable substance of the triticale varieties greatly affected wort quality. Furthermore, the adjunct moiety determined the level of wort viscosity when mashing a combination of malt and triticale. In general, the brewing properties of triticale cv Trinidad were comparable with those of wheat. Copyright © 2004 Society of Chemical Industry
Quality of vacuum packed cold‐smoked salmon during refrigerated storage as affected by high‐pressure processing
Authors: Lakshmanan R , Miskin David , Piggott John R 
Published: December 2004

AbstractEffects of high pressure on the shelf life of vacuum‐packed cold‐smoked salmon during refrigerated storage were analysed with respect to changes associated with sensory, chemical (thiobarbituric acid reacting substances; TBARS), cutting strength and colour parameters. High pressure at higher levels (300 MPa) gave lighter products (p < 0.001), and both pressure and storage time significantly affected the cutting strength (p < 0.001) of samples irrespective of process time and temperature. TBARS values increased with increase in pressure and storage time (p < 0.001). The samples clearly formed three clusters based on the pressure levels applied in principal component analysis of descriptive sensory data. The present experimental design yielded optimal process variables, ie, pressure not greater than 200 MPa produces an organoleptically acceptable product, with 20 min as the processing time to suit commercial production costs. Copyright © 2004 Society of Chemical Industry
Characterization of mechanical stress distributions in a cross section of cucumber fruits: bisector reference line represents tissue anatomy
Authors: Dan Haruka , Okuhara Kazutake , Kohyama Kaoru 
Published: December 2004

AbstractThis study sought to statistically analyze the difference of planar stress distribution in a cross section of cucumber cultivars. The method dealt with statistically comparable data, incorporating both the stress magnitude and their positional information, and was developed to reduce complexity without losing anatomical information. Utilizing the trigonal symmetry of cross‐sectioned cucumbers, a reference line bisecting the cross section was introduced on the rupture frame for referencing the relative locations of stress‐sensing points to the underlying anatomical tissue distribution. The stress–location curves on the reference line statistically differed among the cultivars, especially at the center of the cross section. The corresponding tissue for the center of the curve was the seed cavity, so the cultivar differences arise from mainly the mechanical differences in this tissue. The stress–strain analysis of definite tissues revealed flesh stiffness to exceed the seed cavity stiffness, but both differed from the average stiffness of the whole cross section in all cultivars. Copyright © 2004 Society of Chemical Industry
Emulsifying properties of gelatin conjugated to pectin under alkaline conditions
Authors: Diftis Nickolaos G , Pirzas Themis A , Kiosseoglou Vassilios D 
Published: December 2004

AbstractGelatin–pectin mixed solution incubated under mild alkaline conditions for a period of 4 h exhibited an improvement of emulsion stability in terms of both droplet coalescence and serum separation. Application of SDS–PAGE provided evidence for gelatin–pectin hybrid formation possibly due to amide bonds between the lysine group residues of protein and the esterified carboxyl groups of the polysaccharide. The superior stabilizing properties of the heat‐treated protein–polysaccharide conjugate is attributed to the enhancement of the repulsive steric forces operating between emulsion oil droplets, as a result of conjugate adsorption through their protein moiety. Copyright © 2004 Society of Chemical Industry
Extractive components of boiled–dried scallop adductor muscle and effect on the taste of soup after mixing with chicken leg meat
Authors: Yoneda Chie , Okubo Kumiko , Kasai Midori , Hatae Keiko 
Published: December 2004

AbstractThe extractive components of raw and boiled–dried scallop adductor muscle were examined. On a dry weight basis the levels of total free amino acids, total adenosine triphosphate (ATP) and related compounds, and betaines in the boiled–dried sample were lower than those in the raw muscle, which may have been due to the outflow of these compounds during boiling. Soup prepared from the boiled–dried scallop and chicken leg meat was assessed by sensory evaluation. This soup cooked with the scallop and chicken was stronger in sweetness, umami and body and rated higher in overall preference than the soup containing these ingredients after cooking separately. The inosine monophosphate (IMP) level in the former soup was 4.4 times higher than that in the latter. The adenosine monophosphate (AMP) deaminase (EC 3.5.4.6) activity in the crude extract from the chicken meat was 9.16 units l−1, whereas no activity could be detected in the crude extract from the boiled–dried scallop. It is concluded that AMP, which was mainly derived from the boiled–dried scallop, was converted to IMP by AMP deaminase from the chicken meat during the preparation of the soup, resulting in an improvement in the taste. Copyright © 2004 Society of Chemical Industry
Conditions for stress corrosion cracking to occur from crevice corrosion sites and related electrochemical features
Authors: Wang S. 
Published: December 2004

AbstractThe occurrence of stress corrosion cracking (SCC) from crevice corrosion sites was studied using a kind of occluded U‐bend specimen of Type 316L (UNS S31603) stainless steel. It was done in 0.5 M NaCl solution at room temperature and 50°C. The galvanostatic and potentiostatic polarization methods were adopted. It was found that a tight crevice and high polarization current were the necessary conditions for SCC to occur relative rapidly from crevice corrosion sites. Meanwhile, if there was obvious SCC developing from a crevice corrosion site, the IR drop (or solution resistance) in the crevice path would increase. The increase of IR was attributed to the corrosion product deposition and/or hydrogen bubbles evolved from the cracks. On the other hand, the usually high aspect ratio of stress corrosion cracks, i.e. the inhibited dissolution on the crack walls, might be explained as due to the existence of high IR drops in them.
Impact of wear debris on striated muscle‐ a comparativein‐vivostudy with titanium and stainless steel
Authors: Kraft C.N. , Burian B. , Kunze J. , Diedrich O. , Pennekamp P. , Wimmer M.A. 
Published: December 2004

AbstractWear debris and corrosion products of metal implants induce biological events that may have severe consequences for skeletal muscle microcirculation. We therefore studied in vivo leukocyte‐endothelial cell interaction and leukocyte transmigration in skeletal muscle after confrontation with characterised titanium and stainless steel fretting corrosion particles, and compared these results with those of the bulk materials. Using the hamster dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate in 30 animals that stainless steel induces a more pronounced inflammatory answer in contrast to the implant material titanium. However we were not able to show a general benefit of bulk vs. debris. Overall the study suggests that not only the bulk properties of orthopaedic implants but also the microcirculatory implications of inevitable wear debris may play a role in determining biocompatibility and ultimately longlivety of an implant. The skinfold chamber is a feasible and versatile model for observation of the dynamic process of microvascular response after foreign‐body implantation, and offers much perspective. With a minimum of adverse host reaction, our results indicate that titanium still represents the gold standard in metallic implant material, even in the case of generated wear debris, which shows a comparatively low inflammatory potential.
Controlled release of gentamicin from biomimetic calcium phosphate in vitro. Comparison of four different incorporation methods
Authors: Tadic D. , Welzel T. , Seidel P. , Wüst E. , Dingeldein E. , Epple M. 
Published: December 2004

AbstractCylinders of biomimetic (nanocrystalline) calcium phosphate were loaded with gentamicin by four different methods: 1) dip‐coating, 2) impregnation followed by cold‐isostatic pressing, 3) co‐precipitation followed by cold‐isostatic pressing, and 4) coating of co‐precipitated particles with a biodegradable polymer PDLLA (poly‐D,L‐lactide), followed by uniaxial pressing. The release kinetics were studied in vitro over 10 days. The incorporation by methods 2), 3) and 4) showed a significantly higher long‐term release of active gentamicin than dip‐coating, although there was an initial burst during the first two days with all four methods. With method 4), there was an increase of the released gentamicin after 7 days, and the long‐term release was the highest of these four methods. The results are of considerable interest for the preparation of biodegradable bone implants which are loaded with biologically active substances.
Allergic reactions to metal implants
Authors: Thomas P. , Maier S. , Summer B. 
Published: December 2004

AbstractUpon surgery only transient inflammatory response may be observed in contrast to some developing immune response to metal implants as result of material characteristics or individual reagibility. This is predominantly a macrophage‐driven foreign body like response to particulate debris. Metal implant allergy may develop as result of preexisting allergy or upon newly induced lymphocyte sensitisation. Clinical manifestations encompass eczema, recurrent swelling, seroma formation and impaired wound healing. Allergy‐dependent implant loosening is also suspected. We discuss more detailed clinical‐allergological testing, the analysis of periimplantar immune reaction and report about an interdisciplinary data collection (metal implant allergy register).
Mutant torsinA, which causes early‐onset primary torsion dystonia, is redistributed to membranous structures enriched in vesicular monoamine transporter in cultured human SH‐SY5Y cells
Authors: Misbahuddin Anjum , Placzek Mark R. , Taanman Jan‐Willem , Gschmeissner Steve , Schiavo Giampietro , Cooper J. Mark , Warner Thomas T. 
Published: December 2004

AbstractA single GAG deletion in the DYT1 gene causes primary early‐onset, generalized torsion dystonia. The DYT1 protein product, torsinA, belongs to the AAA+ family of proteins. When overexpressed, wild‐type torsinA localizes mainly to the endoplasmic reticulum, whereas the mutant forms inclusions of unclear biogenetic origin. In this study, overexpressed wild‐type torsinA in human neuroblastoma (SH‐SY5Y) cell lines was distributed throughout the cell body and colocalized with a marker for the endoplasmic reticulum, confirming it is an endoplasmic reticulum protein. However, mutant torsinA showed perinuclear staining and formed distinct globular inclusions, which did not colocalize with endoplasmic reticulum markers. Immunoelectron microscopy of the mutant torsinA inclusions revealed membrane whorls staining for torsinA, as well as labeling of lamellae, isolated bilayers, and perinuclear membranes. This finding shows that mutant torsinA redistributes to specific membranous structures, which may represent different stages of maturation of the intracellular inclusions. The mutant torsinA‐containing bodies were immunoreactive for vesicular monoamine transporter 2 (VMAT2). VMAT2 expression is important for the exocytosis of bioactive monoamines in neurons. Abnormal processing, transport, or entrapment of VMAT2 within the mutant torsinA membranous inclusions, therefore, may affect cellular dopamine release, providing a potential pathogenic mechanism for the DYT1‐dependent dystonia. © 2004 Movement Disorder Society