bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anisotropic mechanical properties of thermoplastic elastomers in situ reinforced with thermotropic liquid‐crystalline polymer fibers revealed by biaxial deformations
Authors: Saikrasun S. , Bualek‐Limcharoen S. , Kohjiya S. , Urayama K. 
Published: December 2004

AbstractThe anisotropic mechanical properties of the thermoplastic elastomer (TPE) in situ reinforced with thermotropic liquid‐crystalline polymer (TLCP) fibers were investigated by uniaxial, strip‐biaxial, and equibiaxial tensile measurements. The in situ composite sheets were prepared from an immiscible blend of a TLCP, Rodrun LC3000, and a TPE, styrene‐(ethylene butylene)‐styrene (SEBS) triblock copolymer, by a melt extrusion process. The uniaxial orientation of the TLCP fibers in the TPE matrix generated during processing yielded a significant mechanical anisotropy in the composites. The biaxial tensile measurements clearly demonstrated the anisotropic mechanical properties of the composites: The modulus in the direction parallel to the machine direction (MD) was considerably higher than that in the transverse direction (TD), even at large deformations; in equibiaxial stretching, the yield strain in the MD was smaller than that in the TD; the composite containing 10 wt % of TLCP exhibited the highest mechanical anisotropy among the composites, with 0–30 wt % TLCP. The latter result was in accord with the SEM observation that the composite with 10 wt % of TLCP possessed the best fibrillar morphology and the highest degree of uniaxial orientation of the TLCP fibers. The yield strains in uni‐ and biaxial elongation for the composite containing 10 wt % of TLCP were almost the same as those for the neat styrene‐ethylene butylene‐styrene. The TLCP phase with good fibrillation did not appreciably alter the original yielding characteristics of the elastomer matrix. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 135–144, 2005
Topological phase transitions in Calabi‐Yau compactifications of M‐theory
Authors: Saueressig F. 
Published: December 2004

AbstractIn this thesis we construct five‐dimensional gauged supergravity actions which describe flop and conifold transitions in M‐theory compactified on Calabi‐Yau threefolds. While the vector multiplet sector is determined exactly, we use the Wolf spaces $X(1+N) = {{U(1+N,2)}\over{U(1+N) \times U(2)}}$ to model the universal hypermultiplet together with N charged hypermultiplets corresponding to winding states of M2‐branes. After specifying the hypermultiplet sector the actions are uniquely determined by M‐theory. As an application we consider five‐dimensional Kasner cosmologies. Including the dynamics of the winding modes, we find smooth cosmological solutions which undergo flop and conifold transitions. Instead of the usual runaway behavior the scalar fields of these solutions generically stabilize in the transition region where they oscillate around the transition locus. The scalar potential thereby induces short episodes of accelerated expansion in the space‐time.
A study of the processing characteristics and mechanical properties of multiple recycled rigid PVC
Authors: Ditta A. S. , Wilkinson A. J. , McNally G. M. , Murphy W. R. 
Published: December 2004

AbstractThis study focuses on the ability of U‐PVC to be processed a number of times. Three different types of U‐PVC were investigated: virgin lead‐stabilized material; virgin calcium/zinc‐stabilized material; and reground, 20‐year‐old, post‐consumer windows. Each material was extruded four times, without any addition of any stabilizers. Samples were taken at each stage for rheological and mechanical analysis. J. Vinyl Addit. Technol. 10:174–178, 2004. © 2004 Society of Plastics Engineers.
Aryl phosphate ester fire‐retardant additive for low‐smoke vinyl applications
Authors: Moy Paul 
Published: December 2004

AbstractAdditives that act as flame retardants can contribute significantly to smoke generation because they decrease the efficiency of the fuel source and, as a result, create a sooty combustion. Work on a new phosphate ester material has shown interesting results and synergies that complement both flame retardancy and low smoke generation in flexible vinyl compositions. This new proprietary aryl phosphate was examined in both neat and blended systems and compared to other typical phosphate ester fire‐retardant (FR) compounds for vinyl. Additionally, the flammability and smoke effects were measured with and without other common vinyl FR additives (zinc borate and ammonium octamolybdate). J. Vinyl Addit. Technol. 10:187–192, 2004. © 2004 Society of Plastics Engineers.
Ceroid, lipofuscin and the ceroid‐lipofuscinoses (Batten Disease)
Authors: Jolly R. D. , Dalefield R. R. , Palmer D. N. 
Published: December 2004

ConclusionThe similar histochemical, fluorescent and ultrastructural appearance of some lipofuscins and the pigment of Batten disease imply some underlying common chemical feature. The similar chloroform—methanol solubility of the protein subunit c in Batten disease and the specific proteins accumulated in thyroid lipofuscin imply that disordered or delayed catabolism of hydrophobic protein may be that common feature.
Refined assignment of the infantile neuronal ceroid‐lipofuscinosis (INCL) locus at 1p32 and the current status of prenatal and carrier diagnostics
Authors: Hellsten E. , Vesa J. , Järvelä I. , Mäkelä T. P. , Santavuori P. , Peltonen L. 
Published: December 2004

ConclusionsThe refined assignment of the INCL locus and the observed strong linkage disequilibrium with one highly informative tetranucleotide repeat polymorphism at 1p32 has created reliable tools for DNA‐based prenatal and carrier diagnosis of INCL in the majority of the families. The observed tendency for homozygosity of one rare allele in Finnish INCL patients suggests a very close physical distance to the INCL gene and provides an excellent starting point for the molecular cloning of the gene. Identification of the gene defect causing this fatal brain disease will reveal the molecular pathogenesis of the disease but also will provide new information of a factor essential for normal postnatal development of cortical neurons.
Refined genetic mapping of juvenile‐onset neuronal ceroid‐lipofuscinosis on chromosome 16
Authors: Mitchison H. M. , Williams R. E. , McKay T. R. , Callen D. F. , Thompson A. D. , Mulley J. C. , Stallings R. L. , Hildebrand C. E. , Moyzis R. K. , Järvelä I. , Peltonen L. , Haines J. , Sutherland G. R. , Gardiner R. M. 
Published: December 2004

ConclusionWe propose that the most likely location for CLN3 is within the interval between loci D16S297 and D16S57 on the proximal portion of the short arm of chromosome 16. The position of the CLN3 gene could be further refined by the use of new polymorphic markers isolated within this interval.We have preliminary data indicating strong linkage disequilibrium with the disease for two markers, D16S298 and D16S299, and we find no recombination between these loci in the CEPH pedigrees (Thompson, Callen, Mitchison and Gardiner, unpublished). We therefore have a good indication that within our expected interval CLN3 is within close proximity of the locus D16S298/299.
Lactic acidosis and mitochondrial dysfunction in two children with peroxisomal disorders
Authors: Holmes R. D. , Moore K. H. , Ofenstein J. P. , Tsatsos P. , Kiechle F. L. 
Published: December 2004

SummaryMitochondrial myopathies and defects in oxidative phosphorylation have been described in some patients with peroxisomal disorders. Although peroxisomes and mitochondria play a role in the β‐oxidation of fatty acids, the metabolic interactions between the two are not well defined. Defects in peroxisomal β‐oxidation are associated with extracellular accumulation of very long‐chain fatty acids and may be accompanied by alterations in the intracellular pool of fatty acyl‐CoAs, which are known to alter mitochondrial function. This study was initiated to examine alterations in the intracellular pool of acyl‐CoAs and mitochondrial function in two children with generalized disorders of peroxisomal function and clinical lactic/pyruvic acidaemia. Fibroblasts were cultured from skin biopsies obtained from one child with neonatal adrenoleukodystrophy (NALD) and another with rhizomelic chondrodysplasia punctata (RCDP). Fibroblast lactate oxidation was significantly inhibited in NALD by 76% and RCDP by 92% compared to control values of 1.9±0.1 nmol/min per mg protein. Pyruvate dehydrogenase (PDH) (mean±SEM; activity nmol/min per mg protein) was: NALD 0.55±0.02 (p<0.01), RCDP 0.44±0.02 (p<0.01), and controls 0.83±0.02. The acid‐insoluble (long‐chain and very long‐chain) acyl‐CoA levels (mean±SEM; pmol/mg protein) were: NALD 129±69 (p<0.01), RCDP 65±15 (p<0.05), and control 45±7. These two patients with generalized peroxisomal disorders exhibited an increase in intracellular acyl‐CoA species accompanied by decreased PDH activity and clinical lactic/pyruvic acidaemia.
The deficient degradation of synthetic 2‐ and 3‐methyl‐branched fatty acids in fibroblasts from patients with peroxisomal disorders
Authors: Van Veldhoven P. P. , Huang S. , Eyssen H. J. , Mannaerts G. P. 
Published: December 2004

SummaryThe oxidation of pristanic and phytanic acids by human skin fibroblasts was compared to that of their synthetic analogues, 2‐methylpalmitic and 3‐methylmargaric acids. The synthetic compounds and natural substrates were degraded at comparable rates in control and X‐linked adrenoleukodystrophy fibroblasts. The α‐decarboxylation of 3‐methylmargaric acid, similarly to that of phytanic acid, was affected in Refsum disease and Zellweger syndrome, but not in X‐linked adrenoleukodystrophy. The β‐oxidation of 2‐methylpalmitic acid, similarly to that of pristanic acid, was deficient in fibroblasts derived from patients suffering from Zellweger syndrome, confirming the importance of peroxisomes in the breakdown of 2‐methyl‐branched fatty acids. No deficiency was observed in fibroblasts from X‐linked adrenoleukodystrophy patients. The 1‐14C‐labelled 2‐ and 3‐methyl‐branched fatty acids, which are easier to synthesize that the natural analogues, are therefore valuable tools for the diagnosis of human peroxisomal disorders.
Cerebral metabolic change after treatment in biotinidase deficiency
Authors: Lott I. T. , Lottenberg S. , Nyhan W. L. , Buchsbaum M. J. 
Published: December 2004

SummaryA 13.5‐year‐old boy with biotinidase deficiency was studied 8 days before and 5 months after biotin treatment by positron emission tomography (PET) and computerized electroencephalographic topography (CET). With biotin treatment there was a marked improvement in the presenting symptom of loss of visual acuity and a more modest recovery in spastic quadraparesis. By PET scanning, the relative metabolic rate for glucose was more than 2 standard deviations lower in the temporal and occipital cortices than in adult or age‐matched controls. With biotin treatment, these values rose to normal limits for both control groups. By CET, normalized EEG equivalent to the relative glucose metabolic rate showed asymmetric slowing in the left temporal and frontal regions before treatment, whereas none of the 32 leads exceeded normal limits of delta, theta, alpha or beta after treatment. These results suggest a strong correlation between clinical, metabolic and electrical measures of brain function as related to biotin treatment in biotinidase deficiency.
Decreased blood coagulation activities in carbohydrate‐deficient glycoprotein syndrome
Authors: Okamoto N. , Wada Y. , Kobayashi M. , Otani K. , Tagawa T. , Futagi Y. , Imayoshi Y. , Hayashi A. , Shimizu A. , Kato Y. 
Published: December 2004

SummaryThe carbohydrate‐deficient glycoprotein (CDG) syndromes are a newly recognized group of inherited metabolic diseases. We report a Japanese brother and sister with a CDG syndrome. Both patients showed decreased activities of blood coagulation Factor XI and of the coagulation inhibitor protein C. In one of them there was also a somewhat decreased activity of Factor IX and of antithrombin III. Isoelectric focusing of antithrombin III revealed a decrease of negatively charged fractions and an increase of more cathodal bands. Furthermore, there was a discrepancy between activity and antigen level of Factor VIII and protein C. The patients had an incidental deficiency of factor XII. This is the first detailed report on blood coagulation systems in the CDG syndromes. These blood coagulation abnormalities may explain at least in part the thrombotic or haemorrhagic complications of the CDG syndromes.
Osteoporosis in lysinuric protein intolerance
Authors: Parto K. , Penttinen R. , Paronen I. , Pelliniemi L. , Simell O. 
Published: December 2004

SummaryLysinuric protein intolerance (LPI) is an autosomal recessive disease characterized by defective transport of cationic amino acids. Patients have an increased incidence of fractures and their skeletal radiographs show osteoporosis. The aim of the study was to characterize the osteopenia in LPI.Twenty‐nine Finnish LPI patients (age range 3.7–44.4 years) were screened for parameters of bone metabolism. Morphometric analysis of bone was carried out in specimens of 9 patients. Collagen synthesis was studied with cultured skin fibroblasts (4 patients) and collagen fibril sizes (3 patients) were measured using electron microscopy.Most histological bone specimens (8/9) showed osteoporosis. Osteomalacia was excluded. Routine clinical laboratory tests were unrevealing. The concentrations of free hydroxyproline and type III procollagen N‐propeptide in serum and the urinary excretion of hydroxyproline were increased in almost all patients during their growth and in about half of adult patients. Collagen synthesis in LPI fibroblast cultures was significantly decreased compared with that in age‐matched controls at 5 (p<0.01), 14 (p<0.01) and still at 30 years (p<0.01), whereas no difference was observed at the age of 44 years (p=N.S.).Osteoporosis in LPI might reflect defective matrix protein synthesis caused by protein deprivation and deficiency of cationic amino acids. Increased collagen turnover can also contribute to the osteoporosis.
Decreased hyperammonaemia and orotic aciduria due to inactivation of ornithine aminotransferase in mice with a hereditary abnormal ornithine carbamoyltransferase
Authors: Seiler N. , Grauffel C. , Daune‐Anglard G. , Sarhan S. , Knödgen B. 
Published: December 2004

SummaryMice with the X‐chromosomal sparse‐fur (spf) mutation are an animal model of some hereditary deficiencies of ornithine carbamoyltransferase (OCT) in man. Orotic aciduria and hyperammonaemia are the most conspicuous metabolic changes in these diseases. Selective inactivation of ornithine aminotransferase (OAT) by 5‐fluoromethylornithine raises endogenous ornithine concentrations so that citrulline formation is effectively catalysed by the aberrant OCT, in spite of its low affinity for ornithine. As a consequence, blood and tissue ammonia concentrations and orotic acid excretion are reduced near to normal values, and the abnormal amino acid patterns in blood, brain and liver are normalized. Selective inactivation of OAT seems a promising therapeutic approach in some hereditary OCT deficiencies, and a tool that may allow us to clarify the role of ammonia and orotic acid in the development of nanism and abnormal behaviour in spf mutant mice.
Pre‐ and postnatal diagnosis of succinic semialdehyde dehydrogenase deficiency using enzyme and metabolite assays
Authors: Gibson K. M. , Baumann C. , Ogier H. , Rossier E. , Vollmer B. , Jakobs C. 
Published: December 2004

SummaryWe Report our cumulative experience for the prenatal diagnosis of succinic semialdehyde dehydrogenase (SSADH) deficiency in seven ‘at‐risk’ pregnancies from four unrelated families. Prenatal diagnosis was performed by determination of 4‐hydroxybutyric acid (4‐HBA) concentration in amniotic fluid using isotope‐dilution gas chromatography‐mass spectrometry in conjunction with assay of SSADH activity in biopsied chorionic villus and/or cultured amniocytes. In three of four pregnancies predicted as affected, confirmation was obtained by demonstration of deficient SSADH activity in fetal tissues. Our results suggest that determination of 4‐HBA concentration in amniotic fluid combined with enzyme determination in cultured or biopsied tissue represents a reliable method for the prenatal diagnosis of SSADH deficiency.
Identification of the stereoisomeric configurations of methylcitric acid produced bysi‐citrate synthase and methylcitrate synthase using capillary gas chromatography‐mass spectrometry
Authors: van Rooyen J. P. G. , Mienie L. J. , Erasmus E. , de Wet W. J. , Ketting D. , Duran M. , Wadman S. K. 
Published: December 2004

SummaryThe absolute separation of the four stereoisomeric configurations of methylcitric acid can be achieved on a nonchiral stationary phase SE30 capillary column using the correspondingO‐acetylated (tri‐(−)‐2‐butyl ester derivatives. Identification of the separated isomers was done using methylcitric acid produced bysi‐citrate synthase and methylcitrate synthase ofCandida lipolitica. si‐Citrate synthase produces the (2S,3S)‐, (2S,3R)‐ and a small amount of the (2R,3S)‐isomers. Methylcitrate synthase produces the (2R,3S)‐isomer, indicating that this enzyme is more stereospecific than the animal citrate synthase enzyme. The (2R,3R)‐isomer may act as an inhibitor of aconitase.
Comparison of the Quaternary Stratigraphy of the Alps and Rocky Mountains ,
Authors: Richmond Gerald M. 
Published: December 2004

Comparison of the glacial and periglacial deposits and soils of the Alps and Rocky Mountains suggests the following correlations. The Donau, Günz, and Mindel are correlated with the Washakie Point (Nebraskan), Cedar Ridge (Kansan), and Sacagawea Ridge (Illinoian). These glaciations are separated and followed by interglacials represented by thick deeply weathered soils, the last being the Mindel/Riss, or Sacagawea Ridge/Bull Lake (Sangamon). The Riss I (Paar) and Riss II (type Riss) Glaciations are correlated with the early and late advances of the Bull Lake Glaciation (early Altonian), and are believed to be different glaciations separated and followed by short interglacials represented by soils of intermediate development at these latitudes. The Alt-Würm period of restricted ice in the Alps is represented only by local unnamed deposits in the Rocky Mountains. In the Alps, at least three interstadial soils occur between the Riss/Würm soil and the oldest Main Würm end moraine. These coincide in time respectively with the beginning and end of the Port Talbot II interstadial and with Plum Point interstadial. The three major end moraines of the Main Würm are correlated with three or locally more end moraines of the early and middle stades of the Pinedale (Woodfordian). Moraines of the late stade of the Pinedale are equivalent to the late glacial and early postglacial moraines of post-Würm but pre-Atlantic age in the Alps.K-Ar dating and tephrochronology in the Rockies suggest that the Washakie Point ended about 1.2 m.y. B.P., the Cedar Ridge about 700,000 B.P., the Sacagawea Ridge about 180,000 B.P., the last great interglacial about 130,000 B.P., and the interglacial separating early and late Bull Lake about 80,000 B.P. Radiocarbon dates from the Alps suggest that the Riss/Würm was about 70,000–60,000 B.P., and that Alt-Würm interstadials occurred at >50,000, 45,000–40,000, 34,000–32,000, and 28,000 B.P. Radiocarbon dates from rock shelter deposits in France indicate minor interstadials in the Main Würm at 21,000–20,000 B.P. and about 17,000 B.P. Both the Main Würm and Pinedale ended about 11,800 B.P.
Climatic Change and Early Population Dynamics in the Southwestern United States
Authors: Irwin-Williams Cynthia , Haynes C. Vance 
Published: December 2004

It is becoming increasingly apparent that the pattern of early human occupation of the Southwestern United States was strongly influenced by the major paleoclimatic events of the period 9500 B.C. to A.D. 700. The size of human populations and the distribution of human settlement at both the regional-topographic and large-scale areal level, known from archaeological research, are directly correlated to climatic change documented by the evidence of geology and palynology.The effect of climatic change is felt through the actions and reactions of the economic subsystem and its linkages with other subsystems. These reactions reflect not only the character of the climatic stimulus but also the existing state of the cultural system. Alternate reactions include direct systemic readaptation to the changed environment (through changed technologies, methods of population control, etc.); or small scale or large scale relocation of populations in different local niches, regions, or areas whose character most closely approximates the conditions to which the cultural system was initially adapted.
Futher Reflections on the Isimila Acheulian
Authors: Cole G.H. , Kleindienst M.R. 
Published: December 2004

Uranium series dates on bone from the Isimila Prehistoric Site, Tanzania, indicate that this East African Acheulian site may be older than originally estimated. They raise the possibility that the Middle Pleistocene sediments containing Acheulian occurrences span a longer range of time than had been supposed. This could add to the plausibility of a contention by Hansen and Keller that differences between artifacts in the uppermost Acheulian horizon and in lower-lying beds are primarily a reflection of change through time rather than a result of different human activities.A summary of the artifact content and associations of the several archeological stratigraphic units is given, and, although a sort of “developmental sequence” can be seen, the existence of discrepant occurrences suggests that an interpretation of directional change as a “function of time” does not, in fact, well accommodate the evidence.Quantitative changes in artifact class proportions in aggregates seem just as likely to be related to local exploitation potentials for early man which were produced during the process of basin in-filling, while observed qualitative differences in the lower-lying horizons may be due to samples biased because of limited exposures which are restricted to a single sedimentary environment.