bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequence‐dependent and independent inhibition specific for mutant ataxin‐3 by small interfering RNA
Authors: Li Yi , Yokota Takanori , Matsumura Ryusuke , Taira Kazunari , Mizusawa Hidehiro 
Published: June 2004

AbstractIn Machado–Joseph disease (MJD) gene, there is a C/G polymorphism immediately after the CAG repeat; the expanded CAG repeat tract is exclusively followed by C, whereas about half of wild‐type alleles are followed by G. Using this C/G polymorphism, we have engineered the small interfering RNA (siRNA) which decreased the expression of mutant ataxin‐3, Q79C, by 96.0%, whereas there was minimal reduction on that of the wild type, Q22G (5.9%). Furthermore, unexpectedly, the expression of another wild‐type allele, Q22C, was also much less suppressed (22.5%) by this siRNA possibly due to difference of the secondary structure of the target RNA. This is the first report of sequence‐independent discrimination of mutant and wild‐type alleles by siRNA. Ann Neurol 2004;56:124–129
Increased susceptibility of S100B transgenic mice to perinatal hypoxia‐ischemia
Authors: Wainwright Mark S. , Craft Jeffrey M. , Griffin W. Sue T. , Marks Alexander , Pineda Jose , Padgett Kyle R. , Van Eldik Linda J. 
Published: June 2004

AbstractS100B is a glial‐derived protein that is a well‐established biomarker for severity of neurological injury and prognosis for recovery. Cell‐based and clinical studies have implicated S100B in the initiation and maintenance of a pathological, glial‐mediated proinflammatory state in the central nervous system. However, the relationship between S100B levels and susceptibility to neurological injury in vivo has not been determined. We used S100B transgenic (Tg) and knockout (KO) mice to test the hypothesis that overexpression of S100B increases vulnerability to cerebral hypoxic‐ischemic injury and that this response correlates with an increase in neuroinflammation from activated glia. Postnatal day 8 Tg mice subjected to hypoxia‐ischemia showed a significant increase in mortality compared with KO and wild‐type mice. Tg mice also exhibited greater cerebral injury and volume loss in the ischemic hemisphere after an 8‐day recovery, as assessed by histopathology and magnetic resonance imaging. Measurement of glial fibrillary acidic protein and S100B levels showed a significant increase in the Tg mice, consistent with heightened glial activation and neuroinflammation in response to injury. This is the first demonstration to our knowledge that overexpression of S100B in vivo enhances pathological response to injury. Ann Neurol 2004;56:61–67
B‐lymphocyte and plasma cell clonal expansion in monosymptomatic optic neuritis cerebrospinal fluid
Authors: Haubold Kurt , Owens Gregory P. , Kaur Paramjit , Ritchie Alanna M. , Gilden Donald H. , Bennett Jeffrey L. 
Published: June 2004

AbstractThe CD19+ B‐lymphocyte and CD138+ plasma cell repertoires in cerebrospinal fluid from four patients with monosymptomatic optic neuritis (ON) were analyzed by single‐cell reverse transcriptase polymerase chain reaction. Amplified heavy (H)– and light (L)–chain antibody segments were sequenced and used to identify the rearranged germline and J segment of closest homology. Both the B‐cell and plasma cell repertoires from ON cerebrospinal fluid demonstrated significant clonal expansion. Up to 75% of the amplified H‐ and L‐chain sequences were contained in overrepresented populations and were somatically mutated, consistent with an antigen‐targeted response. The relationship between clonal populations within the CD19+ B lymphocyte and CD138+ plasma cell populations suggests ongoing mutational pressure to refine antigen binding. Our observations demonstrate that an antigen‐driven clonal B‐lymphocyte and plasma cell response is prominent in the initial stages of central nervous system demyelination and suggest that detection of the disease‐relevant antigens in ON may bear on the inciting antigens in chronic inflammatory disorders such as multiple sclerosis. Ann Neurol 2004;56:97–107
Abnormal lysosomal and ubiquitin‐proteasome pathways in 19p13.3 distal myopathy
Authors: Di Blasi Claudia , Moghadaszadeh Behzad , Ciano Claudia , Negri Tiziana , Giavazzi Alessio , Cornelio Ferdinando , Morandi Lucia , Mora Marina 
Published: June 2004

AbstractWe describe a second large Italian kindred with autosomal dominant vacuolar myopathy characterized by variable severity, adult‐onset weakness of distal limb muscles, and no cardiac involvement. At least 19 individuals over four generations are affected. Histopathological and immunochemical features of the vacuoles, present in many fibers, indicate protein degradation abnormalities with dysregulation of the lysosomal pathway and activation of the ubiquitin‐proteasomal pathway. Linkage analysis localized the defect to the 19p13.3 locus in a region with no known genes. We speculate that the primary defect may be an abnormality in the lysosomal degradation pathway or related components. Ann Neurol 2004;56:133–138
Medial temporal lobe function and structure in mild cognitive impairment
Authors: Dickerson Bradford C. , Salat David H. , Bates Julianna F. , Atiya Monika , Killiany Ronald J. , Greve Douglas N. , Dale Anders M. , Stern Chantal E. , Blacker Deborah , Albert Marilyn S. , Sperling Reisa A. 
Published: June 2004

AbstractFunctional magnetic resonance imaging (fMRI) was used to study memory‐associated activation of medial temporal lobe (MTL) regions in 32 nondemented elderly individuals with mild cognitive impairment (MCI). Subjects performed a visual encoding task during fMRI scanning and were tested for recognition of stimuli afterward. MTL regions of interest were identified from each individual's structural MRI, and activation was quantified within each region. Greater extent of activation within the hippocampal formation and parahippocampal gyrus (PHG) was correlated with better memory performance. There was, however, a paradoxical relationship between extent of activation and clinical status at both baseline and follow‐up evaluations. Subjects with greater clinical impairment, based on the Clinical Dementia Rating Sum of Boxes, recruited a larger extent of the right PHG during encoding, even after accounting for atrophy. Moreover, those who subsequently declined over the 2.5 years of clinical follow‐up (44% of the subjects) activated a significantly greater extent of the right PHG during encoding, despite equivalent memory performance. We hypothesize that increased activation in MTL regions reflects a compensatory response to accumulating AD pathology and may serve as a marker for impending clinical decline. Ann Neurol 2004;56:27–35
POMGnT1 gene alterations in a family with neurological abnormalities
Authors: Vervoort Virginie S. , Holden Kenton R. , Ukadike Kennedy C. , Collins Julianne S. , Saul Robert A. , Srivastava Anand K. 
Published: June 2004

AbstractMuscle‐eye‐brain disease (MEB), is caused by mutations in the POMGnT1 gene. We describe a white family with two siblings affected with congenital hypotonia early‐onset glaucoma, and psychomotor delays. Brain magnetic resonance images (MRIs) showed hydrocephalus, bilateral frontal polymicrogyria, abnormal cerebellum, and characteristic flattened dystrophic pons. We identified novel POMGnT1 gene alterations in this family. Both affected siblings were found to be compound hetrozygotes and carried two missense changes inherited from their mother and one missense change (p.R442C) inherited from their father. Our findings further define the phenotypic spectrum of MEB and its occurrence in the US population. Ann Neurol 2004;56:143–148
Quantification of mechanical deformations induced by an electric field in a semicrystalline organic insulator
Authors: Mamy P. R. , Martinez‐Vega J. , Dupre J. C. , Bretagne N. 
Published: June 2004

AbstractWe studied mechanical deformations induced when an insulating material was subjected to a gradual increase in a direct‐current electric field. Poly(ethylene terephthalate) film was studied with an optical technique, which was nondestructive and involved no physical contact. The experimental results indicated that the level of the induced mechanical deformation depended on the strength of the applied electric stress, the linear dimensions of the area under study, and the thickness of the film. When the studied area was relatively small, the level of the mechanical deformation seemed to be more important. The relationship between the induced mechanical deformation and the electric conduction phenomenon was also examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2313–2321, 2004
Permeation and separation characteristics of acetic acid/water mixtures through poly(vinyl alcohol‐g‐itaconic acid) membranes by pervaporation, evapomeation, and temperature‐difference evapomeation
Authors: Işıklan Nuran , Şanlı Oya 
Published: June 2004

AbstractIn this study, itaconic acid (IA) was grafted onto poly(vinyl alcohol) (PVA) with cerium(IV) ammonium nitrate as an initiator at 45°C. The grafted PVA was characterized with Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. IA‐grafted PVA membranes were prepared with a casting method, and the permeation and separation characteristics of acetic acid/water mixtures were investigated with pervaporation (PV), evapomeation (EV) and temperature‐difference evapomeation (TDEV) methods. The effects of the feed composition, operating temperature, and temperature of the membrane surroundings on the permeation rate and separation factor for the acetic acid/water mixtures were studied. The permeation rates in EV were lower than those in PV, whereas the separation factors were higher. With the TDEV method, the permeation rates decreased and the separation factors increased as the temperature of the membrane surroundings decreased. The prepared membranes were also tested in PV, EV, and TDEV to separate the various compositions of the acetic acid/water mixtures (20–90 wt % acetic acid) at 40°C. The highest separation factor, 686, was obtained in TDEV with a 90 wt % acetic acid concentration in the feed. The activation energies of permeation in PV and EV were calculated to be 8.5 and 10.2 kcal/mol, respectively, for a 20 wt % acetic acid solution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2322–2333, 2004
The fractal and scaling analysis of chemical reactions
Authors: Kozlov G. V. , Shustov G. B. , Zaikov G. E. 
Published: June 2004

AbstractIt is shown that the geometrical factor controlling a thermooxidative degradation course is effective spectral dimension d or factor β. In turn, parameters d and β are a function of a polymer melt structure characterized by its fractal dimension Δf. The applicability of this or that scaling relationship allows the evaluation of general features of chemical reactions in the thermooxidative degradation process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2343–2347, 2004
Deacetylation of β‐chitin. II. Factorial experimental design
Authors: Chen Cheng‐Ho , Wang Fang‐Yu , Ou Zu‐Pei 
Published: June 2004

AbstractA 23‐factorial experimental design has been used to study the main, two‐factor‐interaction, and three‐factor‐interaction effects of the NaOH concentration (X1), deacetylation time (X2), and deacetylation temperature (X3) on the degree of deacetylation (DD) of deacetylated products prepared from β‐chitin. Because the DD values of deacetylated products increase as X1, X2, or X3 increases, the main, two‐factor‐interaction, and three‐factor‐interaction effects for these three deacetylation conditions are positive. The sequence of the main effects on the DD values of deacetylated products is X3 < X2 < X1. The sequence of the two‐factor‐interaction effects on the DD values of deacetylated products is X2 versus X3 < X1 versus X3 < X1 versus X2. The prediction equation is Ŷ = 42.4 + 13.9X1 + 9.4X2 + 8.4X3 + 5.8X1X2 + 4.9X1X3 + 3.7X2X3 + 2.6X1X2X3 (where Ŷ is the predicted response) © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2423–2428, 2004
Deacetylation of β‐chitin. I. Influence of the deacetylation conditions
Authors: Chen Cheng‐Ho , Wang Fang‐Yu , Ou Zu‐Pei 
Published: June 2004

AbstractThe influences of the deacetylation temperature, deacetylation time, and NaOH concentration on the degree of deacetylation (DD) of deacetylated products prepared from β‐chitin are discussed. The DD values of deacetylated products are related to the ratio of the signal intensities of methyl on acetyl groups and the first anomeric carbon, which are obtained from 13C‐NMR spectra. The results show that the DD values of deacetylated product increase as the NaOH concentration, deacetylation time, or deacetylation temperature increases. The thermal properties, chemical structures, and crystalline characteristic of deacetylated products are significantly related to their DD values. Differential scanning calorimetry shows that the peak temperature is slightly increased as the DD values of deacetylated products of β‐chitin increase. Thermogravimetric analysis shows that the thermal degradation onset temperature of deacetylated products decreases as the DD values increase. Fourier transform infrared spectra show that the intensity of a specific absorption peak of NH2 in deacetylated products significantly increases as DD increases. X‐ray diffraction patterns of deacetylated products with DD values of 17.5 and 44.7% have three significant diffraction peaks. However, there are only two diffraction peaks found in products with higher DD values of 76.5 and 94.7%. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2416–2422, 2004
Synthesis and evaluation of high‐performance ethylene–propylene–diene terpolymer/organoclay nanoscale composites
Authors: Acharya H. , Pramanik M. , Srivastava S. K. , Bhowmick A. K. 
Published: June 2004

AbstractThe main objective of this study was to synthesize and characterize the properties of ethylene–propylene–diene terpolymer (EPDM)/clay nanocomposites. Pristine clay, sodium montmorillonite (Na+–MMT), was intercalated with hexadecyl ammonium ion to form modified organoclay (16Me–MMT) and the effect of intercalation toward the change in interlayer spacing of the silicate layers was studied by X‐ray diffraction, which showed that the increase in interlayer spacing in Na+–MMT by 0.61 nm is attributed to the intercalation of hexadecyl ammonium ion within the clay layers. In the case of EPDM/16Me–MMT nanocomposites, the basal reflection peak was shifted toward a higher angle. However, gallery height remained more or less the same for different EPDM nanocomposites with organoclay content up to 8 wt %. The nanostructure of EPDM/clay composites was characterized by transmission electron microscopy, which established the coexistence of intercalated and exfoliated clay layers with an average layer thickness in the nanometer range within the EPDM matrix. The significant improvement in thermal stability and mechanical properties reflects the high‐performance nanocomposite formation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2429–2436, 2004
Structure and properties of AlSi/polyester coating
Authors: Öksüz Mustafa , Yıldırım Hüseyin 
Published: June 2004

AbstractPowder coatings, which are formed by plasma spray technique, are being used in industrial applications. Resistance of plastics and their based composite materials to chemicals, solvents, atmospheric conditions, and high impact strength even at low service temperature increases the importance of plastic and plastic based coating applications. In this study, aluminum silicon based polyester (AlSi/polyester) coating was applied by plasma spraying technique with and without intermediate bond layer coat (NiAl). The effect of coating thickness, intermediate bond layer coat, and plasma spraying parameters on bond strength of coating were studied experimentally. The bond strengths of the coatings were determined according to the ASTM C‐633–79. Microstructures of the coating were examined by optic microscopy and scanning electron microscopy (SEM), respectively. Obtained results indicated that plasma spraying current rate, coating thickness, and spraying distance were important factors on bond strength of coating. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2437–2444, 2004
Use of laser spallation to measure the adhesion of optical fiber coatings
Authors: Logunov Stephan , Kouzmina Inna , Winningham Michael , Fewkes Edward 
Published: June 2004

AbstractThe correlation between chemical effects of some typical optical fiber coating formulations and adhesion to glass was studied by the use of laser spallation. The technique was able to show verifiable differences between dissimilar materials and demonstrated a good correlation to adhesion values determined by mechanical peel testing, and to pullout values measured on coated optical fiber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2459–2468, 2004
Interface and mechanical properties of poly(methyl methacrylate)–fiber composites
Authors: Xie Tingxiu , Yang Guisheng 
Published: June 2004

AbstractLong‐fiber pellets were made by an in situ pultrusion process. Fiber‐reinforced composites were prepared by an injection‐molding process and an extrusion/injection‐molding method with pellets, respectively. SEM observations showed that the strong interface was maintained during the injection process for low shearing forces, although polymer adhesion to the fiber surface was completely delaminated in the process of extrusion/injection molding for very high shearing forces. Enhanced adhesion of composites promoted substantial improvement of mechanical properties compared to those with poor adhesion. However, the enhanced adhesion between the fiber and the matrix also sacrificed the impact resistance properties. Longer fibers substantially enhanced the properties of composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2478–2483, 2004
Synthesis and characterization of polybutadiene with monotitanocene/methylaluminoxane catalyst
Authors: Zhu Fangming , Huang Dongdong , Lin Shangan 
Published: June 2004

AbstractButadiene was polymerized using a monotitanocene complex of η5‐pentamethylcyclopentadienyltribenzyloxy titanium [Cp*Ti(OBz)3] in the presence of four types of modified methylaluminoxanes (mMAO), which contained different amounts of residual trimethylaluminum (TMA). The titanium oxidation states in Cp*Ti(OBz)3/mMAO and Cp*Ti(OBz)3/mMAO/triisobutylaluminum (TIBA) catalytic systems were determined by redox titration method. The effects of various oxidation states of titanium active species on butadiene polymerization were investigated. It was found that Ti(III) active species is more effective for preparing polybutadiene with high molecular weight. The addition of TIBA to the Cp*Ti(OBz)3/mMAO system could reduce a greater number of Ti(IV) complexes to Ti(III) species and lead to significant increases of polymerization activity and molecular weight of polymer, whereas the polybutadiene microstructure was only slightly changed. On the basis of microstructure and property characterization by FTIR, 13C‐NMR, DSC, and WAXD, all resultant polymers were proved to be amorphous polybutadiene with mixed 1,2; cis‐1,4; and trans‐1,4 structures. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2494–2500, 2004
Synthesis and Antibacterial Evaluation of 1β‐Methyl‐2‐(5‐substituted heterocyclic carbamoyl)pyrrolidin‐3‐ylthio)carbapenem Derivatives
Authors: Lee Joo‐Shin , Choa Jung‐Hyuck , Cho Heeyeong , Oh Chang‐Hyun 
Published: June 2004

Abstract>The synthesis of a new series of 1β‐methylcarbapenems having a substituted heterocyclic carbamoyl pyrrolidine moiety is described. Their in vitro antibacterial activity against both gram‐positive and gram‐negative bacteria was tested, and the effect of heterocyclic substituents on the pyrrolidine was investigated. One particular compound (IIId) having a substituted oxadiazole moiety showed the most potent antibacterial activity.
Membrane‐aerated microbioreactor for high‐throughput bioprocessing
Authors: Zanzotto Andrea , Szita Nicolas , Boccazzi Paolo , Lessard Philip , Sinskey Anthony J. , Jensen Klavs F. 
Published: June 2004

AbstractA microbioreactor with a volume of microliters is fabricated out of poly(dimethylsiloxane) (PDMS) and glass. Aeration of microbial cultures is through a gas‐permeable PDMS membrane. Sensors are integrated for on‐line measurement of optical density (OD), dissolved oxygen (DO), and pH. All three parameter measurements are based on optical methods. Optical density is monitored via transmittance measurements through the well of the microbioreactor while dissolved oxygen and pH are measured using fluorescence lifetime‐based sensors incorporated into the body of the microbioreactor. Bacterial fermentations carried out in the microbioreactor under well‐defined conditions are compared to results obtained in a 500‐mL bench‐scale bioreactor. It is shown that the behavior of the bacteria in the microbioreactor is similar to that in the larger bioreactor. This similarity includes growth kinetics, dissolved oxygen profile within the vessel over time, pH profile over time, final number of cells, and cell morphology. Results from off‐line analysis of the medium to examine organic acid production and substrate utilization are presented. By changing the gaseous environmental conditions, it is demonstrated that oxygen levels within the microbioreactor can be manipulated. Furthermore, it is demonstrated that the sensitivity and reproducibility of the microbioreactor system are such that statistically significant differences in the time evolution of the OD, DO, and pH can be used to distinguish between different physiological states. Finally, modeling of the transient oxygen transfer within the microbioreactor based on observed and predicted growth kinetics is used to quantitatively characterize oxygen depletion in the system. © 2004 Wiley Periodicals, Inc.
Toward construction of a self‐sustained clock‐like expression system based on the mammalian circadian clock
Authors: Chilov Dmitri , Fussenegger Martin 
Published: June 2004

AbstractDespite recent advances in circadian biology, detailed understanding of how a biological pacemaker system is assembled, maintained, and regulated continues to be a significant challenge. We have assembled and characterized a first‐generation, regulatable, self‐sustained clock‐like expression system based on key components of the mammalian circadian clock. The molecular setup of the clock‐like oscillator was reduced to the core set of positive and negative elements common to all known circadian pacemakers. Sophisticated tetracycline‐responsive multi‐cistronic expression integrated with forefront lentiviral transduction tools enabled autoregulated reporter transgene expression in a human cell line. We characterized transgene expression kinetics of an artificial oscillator and showed that its expression profiles could be modulated by a serum shock and administration of regulating tetracycline antibiotics. Design of a generic mammalian clock‐like expression system will offer novel opportunities to study circadian biology and may provide a unique tool for rhythmic expression of desired transgenes fostering advances in biopharmaceutical manufacturing, gene therapy, and tissue engineering. © 2004 Wiley Periodicals, Inc.
Eukaryoten ohne Mitochondrien — Fakt oder Illusion?
Authors: Hachtel Wolfgang 
Published: June 2004

AbstractDie Mitochondrien der Eukaryoten haben sich nach allgemeiner Auffassung aus ehemals freilebenden Bakterien entwickelt, die zunächst als Endosymbionten in die Zellen urtümlicher, einzelliger Eukaryoten aufgenommen worden waren. Dass es auch heute noch ursprüngliche Protozoen gibt, die keine Mitochondrien besitzen, galt lange als unstrittig. Sie werden als Archaezoa zusammengefasst. Diese Organismen könnten als rezente Belege einer extrem frühen Phase der Eukaryoten‐Evolution vor dem endosymbiontischen Erwerb von Mitochondrien gelten. Diese Ansicht gerät aber immer mehr ins Wanken, denn die Beweise mehren sich, dass etliche Archaezoen doch erst sekundär frei von Mitochondrien sind.