bluuebunny/crossref_metadata_2025_split huggingface dataset:
Instability for functional differential equations
Authors: Haddock John R. , Zhao Jiaxiang 
Published: September 2006

AbstractIn this paper, we extend the study on instability in [11] to autonomous functional differential equations with infinite delay by means of Liapunov–Razumikhin techniques, and to nonautonomous functional differential equations with finite or infinite delay via limiting equations. Examples are used throughout the paper for illustrations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fundamental solutions and mapping properties of semielliptic operators
Authors: Hile G. N. 
Published: September 2006

AbstractAn explicit formula is given for a fundamental solution for a class of semielliptic operators. The fundamental solution is used to investigate properties of these operators as mappings between weighted function spaces in ℝn . Necessary and sufficient conditions are given for such a mapping to be an isomorphism. Results apply, for example, to elliptic, parabolic, and generalized p ‐parabolic operators. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polyhedral Oligomeric Silsesquioxane Containing Copolymers for Negative‐Type Photoresists
Authors: Lin Ho‐May , Wu Shi‐Yin , Huang Pei‐Yuan , Huang Chih‐Feng , Kuo Shiao‐Wei , Chang Feng‐Chih 
Published: September 2006

AbstractSummary: A series of methacrylate copolymers containing polyhedral oligomeric silsesquioxane (POSS) was synthesized from the free radical copolymerization of methacrylic acid, methyl methacrylate, and isobutyl propylmethacryl polyhedral oligosilsesquioxanes, and then were modified with glycidyl methacrylate to serve as negative‐type photoresists. The UV/Vis spectroscopy reveals that the incorporation of POSS moiety into the copolymer results in a slight decrease in transparency from 99 to 92.5% (at wavelength = 365 nm). The photosensitivity in terms of resist sensitivity (D), contrast (γ), and photopolymerization rate are significantly increased with increase in the POSS content. In addition, the induction time is reduced from 0.520 to 0.515 min after incorporating the POSS unit based on photo‐DSC analyses. These observed results can be rationalized as due to hydrogen bonding interactions between siloxane and hydroxyl groups in copolymers which tend to attract the methacrylate double bonds surrounding POSS units to crosslink, thereby enhancing the photopolymerization rate and sensitivity. We further evaluate the lithographic property of a photoresist under a collimated exposure.Compact double bonds zone induced via hydrogen bonding.magnified imageCompact double bonds zone induced via hydrogen bonding.
Properties of Nylon‐6/Na+‐Montmorillonite Nanocomposites Obtained by Hydrolyzed Ring‐Opening Polymerization
Authors: Liu Andong , Xie Tingxiu , Yang Guisheng 
Published: September 2006

AbstractSummary: Nylon‐6/Na+‐montmorillonite (MMT) nanocomposites (NNNs) are synthesized by a hydrolyzed ring‐opening polymerization. At a loading of only 2 wt.‐% MMT, the tensile modulus, the flexural modulus, and the heat distortion temperature of the NNNs exhibit increases of nearly 20%, 60%, and 63 °C, respectively. Compared with that of neat nylon‐6, the temperature of the main α‐relaxation (Tα) of the NNNs is shifted 3.6 °C toward higher temperatures and two β‐relaxation peaks are observed. Another interesting phenomenon is that there is a new melting peak (at about 206 °C) for the NNNs.DSC second heating curves of neat nylon‐6 (N6), nylon‐6/Na+‐MMT nanocomposites with highly swollen Na+‐MMT (NHM), and nylon‐6/Na+‐MMT nanocomposites with slightly swollen Na+‐MMT (NSM) with various amounts of Na+‐MMT.magnified imageDSC second heating curves of neat nylon‐6 (N6), nylon‐6/Na+‐MMT nanocomposites with highly swollen Na+‐MMT (NHM), and nylon‐6/Na+‐MMT nanocomposites with slightly swollen Na+‐MMT (NSM) with various amounts of Na+‐MMT.
Photoinitiated Free Radical Polymerization Using Benzoxazines as Hydrogen Donors
Authors: Tasdelen M. Atilla , Kiskan Baris , Yagci Yusuf 
Published: September 2006

AbstractSummary: Free radical polymerization of methyl methacrylate (MMA) is initiated upon irradiation at λ > 350 nm in CH2Cl2 that contains benzoxazine (P‐a) and one of the following photosensitizers: benzophenone (BP), thioxanthone (TX), 2‐chlorothioxanthone (CTX), 2‐isopropyl thioxanthone (ITX), and camphorquinone (CQ). The postulated mechanism is based on the intermolecular reaction of the excited photosensitizer with the tertiary amino moiety of the ground state P‐a and a subsequent hydrogen abstraction reaction. The resulting aminoalkyl radicals initiate the polymerization. The incorporation of P‐a groups into polymers is demonstrated by spectroscopic methods. The possibility of deep curing using the described photoinitiating system followed by the thermal ring opening of the incorporated P‐a groups is also demonstrated.Schematic of the photoinitiated free radical polymerization using benzoxazines as hydrogen donors.magnified imageSchematic of the photoinitiated free radical polymerization using benzoxazines as hydrogen donors.
Premature translation of transition protein 2 mRNA causes sperm abnormalities and male infertility
Authors: Tseden Khailun , Topaloglu Özlem , Meinhardt Andreas , Dev Arvind , Adham Ibrahim , Müller Christian , Wolf Stephan , Böhm Detlef , Schlüter Gregor , Engel Wolfgang , Nayernia Karim 
Published: September 2006

AbstractDuring mammalian spermiogenesis somatic histones are replaced at first by transition proteins, which are in turn replaced by the protamines, forming the sperm nucleoprotamines. It is believed that transition protein 2 (Tnp2) is necessary for maintaining the normal processing of protamines and, consequently, the completion of chromatin condensation. The transition protein mRNAs are stored in translationally inert messenger ribonucleoprotein particles for up to 7 days until translational activation in elongated spermatids. Substantial evidence suggests an involvement of 3′untranslated region (UTR) in the translational regulation of the Tnp2 mRNAs. In order to determine the role of Tnp2 3′UTR in translational regulation and to study whether the translational repression of Tnp2 mRNA is necessary for normal spermatid differentiation in mice, we generated transgenic mice that carry a Tnp2‐hGH transgene. In this transgene, 3′UTR of Tnp2 gene was replaced by 3′ 3′UTR of human growth hormone gene. In these transgenic animals, transcription and translation of Tnp2 occur simultaneously in round spermatids which is an evidence for involvement of Tnp2 3′UTR in its translation repression. Premature translation of Tnp2 mRNA caused abnormal head morphogenesis, reduced sperm motility and male infertility. These results show clearly that a strict temporal and stage‐specific Tnp2 translation is necessary for the correct differentiation of round spermatids into mature spermatozoa and for male fertility. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Anterior interosseous nerve conduction study: Normative data
Authors: Vucic Steve , Yiannikas Con 
Published: September 2006

AbstractNeurophysiological techniques assessing anterior interosseous nerve (AIN) function and employing surface electrode recordings from the flexor pollicis longus (FPL), have been limited by technical difficulties. The aim of this study was to describe a surface electrode recording technique of investigating the AIN by recording compound muscle action potentials (CMAPs) from FPL. CMAP responses exhibited a negative onset, suggesting that they originated from FPL, and this was confirmed by needle recording. Normative data has been established that may prove useful in future studies assessing pathological involvement of the anterior interosseous nerve. Muscle Nerve, 2006
Molecular and cellular defects of skeletal muscle in an animal model of acute quadriplegic myopathy
Authors: Mozaffar Tahseen , Haddad Fadia , Zeng Ming , Zhang Li Ying , Adams Greg R. , Baldwin Kenneth M. 
Published: September 2006

AbstractMuscle denervation and concomitant high‐dose dexamethasone treatment in rodents produces characteristic pathologic features of severe muscle atrophy and selective myosin heavy filament (MyHC) depletion, identical to those seen in acute quadriplegic myopathy (AQM), also known as critical illness myopathy. We tested the hypothesis that defective pre‐translational processes contribute to the atrophy and selective MyHC depletion in this model. We examined the effects of combined glucocorticoid–denervation treatment on MyHC and actin mRNA populations; we also studied mRNA expression of the myogenic regulatory factors (MRFs), primary transcription factors for MyHC. Adult female rats were subjected to proximal sciatic denervation followed by high‐dose dexamethasone (DD) treatment (5 mg/kg body weight daily) for 7 days. Disease controls included rats treated with denervation alone (DN) or dexamethasone alone (DX). At 1 week the plantaris atrophied by ∼42% in DD muscles. DD treatment resulted in selective MyHC protein depletion; actin protein concentration was not significantly changed. Despite an increase in total RNA concentration in DN and DD muscles, MyHC and actin mRNA concentrations were significantly decreased in these muscles. MyHC mRNA showed a significantly more extensive depletion relative to actin mRNA in DD muscles. Glucocorticoid treatment did not influence a denervation‐induced increase in the mRNA expression of the MRFs. We conclude that a deleterious interaction between glucocorticoid and denervation treatments in skeletal muscle is responsible for pre‐translational defects that reduce actin and MyHC mRNA substrates in a disproportionate fashion. The resultant selective MyHC depletion contributes to the severe muscle atrophy. Muscle Nerve, 2006
Whipple's disease with muscle impairment
Authors: Puget Marie , Iwaz Jean , Tristan Anne , Streichenberger Nathalie 
Published: September 2006

AbstractA 67‐year‐old man presented with myalgia, muscle atrophy, and a history of seronegative polyarthritis. Blood tests showed inflammation but no hematologic or immunologic abnormalities. Muscle biopsy revealed no vasculitis or myositis but Tropheryma whipplei was detected by polymerase chain reaction in muscle, blood, and duodenum specimens; this was confirmed by immunohistochemistry. Ceftriaxone led to clinical improvement. Although rare, Whipple's disease should be considered in the differential diagnosis of diffuse myopathy. Muscle Nerve, 2006
Proapoptotic factor Bax is increased in satellite cells in the tibialis anterior muscles of old rats
Authors: Krajnak Kristine , Waugh Stacey , Miller Roger , Baker Brent , Geronilla Kenneth , Alway Stephen E. , Cutlip Robert G. 
Published: September 2006

AbstractAging impairs the ability of muscle to adapt to exercise or injury. The goal of this study was to determine whether age‐related changes in muscle adaptability could be the result of satellite cell apoptosis. Ten days after exposure to an injury protocol, estimates of edema in the exposed tibialis anterior muscles were higher in old (30 months) than young (3 months) rats, and isometric force levels were lower in old rats. Both young and old rats displayed an increase in MyoD labeling in the exposed muscle, indicating that injury induced satellite‐cell activation. However, there were more MyoD‐labeled cells that coexpressed the proapoptotic factor, Bax, in old than in young rats, suggesting that decrements in muscle recovery may be associated with an increase in satellite‐cell apoptosis. Based on these findings we conclude that reducing satellite‐cell apoptosis in aged animals may improve muscle recovery after injury. Muscle Nerve, 2006
Expanding the phenotypes of the Pro56SerVAPBmutation: Proximal SMA with dysautonomia
Authors: Marques Vanessa D. , Barreira Amilton A. , Davis Mary B. , Abou‐Sleiman Patrick M. , Silva Wilson A. , Zago Marco A. , Sobreira Claudia , Fazan Valéria , Marques Wilson 
Published: September 2006

AbstractThe phenotype of 16 members of a family affected by a late‐onset, dominant, progressive, motor and autonomic disorder is described. TheVAPB(Pro56Ser) mutation was detected in Brazilian families with different phenotypes of motor neuron disorders. In this family, proximal and axial muscle weakness and atrophy, associated with abdominal protrusion, defined the motor phenotype. Death occurred in 10–15 years due to respiratory insufficiency. Tone and tendon reflexes were decreased and a distal tremor was common. Sensation was preserved. Autonomic abnormalities were also present, including choking, chronic intestinal constipation, sexual dysfunction, and sudomotor abnormalities, and on nerve morphology there was involvement of unmyelinated fibers. Electromyography disclosed ongoing denervation and reinnervation. Isolated dysfunction of motor and autonomic neurons is unusual among the spinal muscular atrophies. On this basis, this condition seems to represent a new category of disease. Muscle Nerve, 2006
Hip joint position modulates volitional knee extensor muscle activity after stroke
Authors: Lewek Michael D. , Schmit Brian D. , Hornby T. George , Dhaher Yasin Y. 
Published: September 2006

AbstractEvidence from animal and human models has demonstrated the importance of hip proprioceptors and vestibular inputs in modulating lower‐extremity muscle activity through reflex pathways. Comprehension of the role of these sensory inputs following stroke may be important in understanding pathological muscle activity during functional activities. We therefore examined the influence of both hip and head/trunk position on volitional quadriceps activity in chronic stroke and control subjects. With the knee held at 60°, maximal voluntary isometric quadriceps contractions were elicited with trunk orientation (head position) and hip angle systematically positioned at 0°, 45°, and 90°. Integrated electromyographic activity from the quadriceps was compared between groups and conditions. Vasti activity in the stroke group was greater in a seated upright posture (hip flexed) than supine (hip neutral). Controlling for vestibular input, the stroke group demonstrated greater quadriceps activity (VL and RF) with a neutral hip compared to flexion. Such findings may have implications for understanding inappropriate muscle activity during walking after stroke, as hip extension occurs immediately prior to toe off, when inappropriate quadriceps activity is commonly observed. Muscle Nerve, 2006
Metalloprotease‐induced ectodomain shedding of neural cell adhesion molecule (NCAM)
Authors: Hinkle C. Leann , Diestel Simone , Lieberman Jeffrey , Maness Patricia F. 
Published: September 2006

AbstractTransmembrane forms of neural cell adhesion molecule (NCAM140, NCAM1801) are key regulators of neuronal development. The extracellular domain of NCAM can occur as a soluble protein in normal brain, and its levels are elevated in neuropsychiatric disorders, such as schizophrenia; however the mechanism of ectodomain release is obscure. Ectodomain shedding of NCAM140, releasing a fragment of 115 kD, was found to be induced in NCAM‐transfected L‐fibroblasts by the tyrosine phosphatase inhibitor pervanadate, but not phorbol esters. Pervanadate‐induced shedding was mediated by a disintegrin metalloprotease (ADAM), regulated by ERK1/2 MAP kinase. In primary cortical neurons, NCAM was shed at high levels, and the metalloprotease inhibitor GM6001 significantly increased NCAM‐dependent neurite branching and outgrowth. Moreover, NCAM‐dependent neurite outgrowth and branching were inhibited in neurons isolated from a transgenic mouse model of NCAM shedding. These results suggest that regulated metalloprotease‐induced ectodomain shedding of NCAM down‐regulates neurite branching and neurite outgrowth. Thus, increased levels of soluble NCAM in schizophrenic brain have the potential to impair neuronal connectivity. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Pre‐/post‐otic rhombomeric interactions control the emergence of a fetal‐like respiratory rhythm in the mouse embryo
Authors: Borday C. , Coutinho A. , Germon I. , Champagnat J. , Fortin G. 
Published: September 2006

AbstractHow regional patterning of the neural tube in vertebrate embryos may influence the emergence and the function of neural networks remains elusive. We have begun to address this issue in the embryonic mouse hindbrain by studying rhythmogenic properties of different neural tube segments. We have isolated pre‐ and post‐otic hindbrain segments and spinal segments of the mouse neural tube, when they form at embryonic day (E) 9, and grafted them into the same positions in stage‐matched chick hosts. Three days after grafting, in vitro recordings of the activity in the cranial nerves exiting the grafts indicate that a high frequency (HF) rhythm (order: 10 bursts/min) is generated in post‐otic segments while more anterior pre‐otic and more posterior spinal territories generate a low frequency (LF) rhythm (order: 1 burst/min). Comparison with homo‐specific grafting of corresponding chick segments points to conservation in mouse and chick of the link between the patterning of activities and the axial origin of the hindbrain segment. This HF rhythm is reminiscent of the respiratory rhythm known to appear at E15 in mice. We also report on pre‐/post‐otic interactions. The pre‐otic rhombomere 5 prevents the emergence of the HF rhythm at E12. Although the nature of the interaction with r5 remains obscure, we propose that ontogeny of fetal‐like respiratory circuits relies on: (i) a selective developmental program enforcing HF rhythm generation, already set at E9 in post‐otic segments, and (ii) trans‐segmental interactions with pre‐otic territories that may control the time when this rhythm appears. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Intrastriatal administration of human immunodeficiency virus‐1 glycoprotein 120 reduces glial cell‐line derived neurotrophic factor levels and causes apoptosis in the substantia nigra
Authors: Nosheny Rachel L. , Bachis Alessia , Aden Sadia A. , De Bernardi Maria A. , Mocchetti Italo 
Published: September 2006

AbstractUninfected neurons of the substantia nigra (SN) degenerate in human immunodeficiency virus (HIV)‐positive patients through an unknown etiology. The HIV envelope glycoprotein 120 (gp120) causes apoptotic neuronal cell death in the rodent striatum, but its primary neurotoxic mechanism is still under investigation. Previous studies have shown that gp120 causes neurotoxicity in the rat striatum by reducing brain‐derived neurotrophic factor (BDNF). Because glial cell line‐derived neurotrophic factor (GDNF) and BDNF are neurotrophic factors crucial for the survival of dopaminergic neurons of the SN, we investigated whether gp120 reduces GDNF and BDNF levels concomitantly to induce apoptosis. Rats received a microinjection of gp120 or vehicle into the striatum and were sacrificed at various time intervals. GDNF but not BDNF immunoreactivity was decreased in the SN by 4 days in gp120‐treated rats. In these animals, a significant increase in the number of caspase‐3‐ positive neurons, both tyrosine hydroxylase (TH)‐positive and ‐negative, was observed. Analysis of TH immunoreactivity revealed fewer TH‐positive neurons and fibers in a medial and lateral portion of cell group A9 of the SN, an area that projects to the striatum, suggesting that gp120 induces retrograde degeneration of nigrostriatal neurons. We propose that dysfunction of the nigrostriatal dopaminergic system associated with HIV may be caused by a reduction of neurotrophic factor expression by gp120. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Kinetic model of reversible addition fragmentation chain transfer polymerization of styrene in seeded emulsion
Authors: Peklak A. David , Butté Alessandro 
Published: September 2006

AbstractA detailed model describing the kinetics of living polymerization mediated by reversible addition‐fragmentation chain transfer (RAFT) in seeded emulsion polymerization is developed. The model consists of a set of population balance equations of the different radical species in the aqueous phase and in the particle phase (accounting for radical segregation) as well as for the dormant species in the particle phase. The entire population of radicals was divided into several distinguished species, based on their length and their chain end group. The model results are helpful in understanding inhibition and retardation phenomena that are typical for RAFT emulsion polymerizations. While inhibition is due to the radical loss in form of the RAFT leaving group, retardation is mostly caused by a small amount of short dormant chains in the particle phase, leading to a slight increase of radical loss via RAFT exchange with radicals entering a particle. The model results are compared to a series of experiments, using cumyl dithiobenzoate as a RAFT agent in polymerizations of styrene. The agreement between experimental and model results is good and, notably, the only parameters considered adjustable were the RAFT exchange rate coefficients. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6114–6135, 2006
Copolymerization of propylene and disubstituted diallylsilanes involving intramolecular cyclization with stereoselective zirconocene catalysts
Authors: Naga Naofumi 
Published: September 2006

AbstractThe copolymerization of propylene and disubstituted diallylsilanes [(CH2 CHCH2)2R2Si (R = CH3 or C6H5)] was investigated with isoselective and syndioselective zirconocene catalysts with methylaluminoxane as a cocatalyst. The syndioselective catalyst showed a higher reactivity for disubstituted diallylsilanes than the isoselective catalysts. Diallyldimethylsilane was incorporated into the polymer chain via cyclization insertion preferentially and formed 3,5‐disubstituted dimethylsilacyclohexane units in the polypropylene main chain. In the copolymerization with diallyldiphenylsilane, diallyldiphenylsilane was copolymerized via both cyclization insertion and 1,2‐insertion, which formed a pendant allyl group. The structures of isolated silacyclohexane units, determined by 13C NMR and distortionless enhancement by polarization transfer spectroscopy, proved that the 1,2‐insertion of diallylsilanes proceeded with enantiomorphic site control; however, the diastereoselectivity of the cyclization reaction was independent of the stereoselectivity of the catalysts used, and cis‐silacyclohexane units were mainly formed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6083–6093, 2006
Is lGnRH‐III the most potent GnRH analog containing only natural amino acids that specifically inhibits the growth of human breast cancer cells?
Authors: Herédi‐Szabó Krisztina , Murphy Richard F. , Lovas Sándor 
Published: September 2006

AbstractAnalogs of the decapeptide, gonadotropin‐releasing hormone (GnRH), used in the treatment of hormone‐dependent tumors, contain numerous unnatural amino acids, giving rise to many adverse effects. lGnRH‐III, a natural isoform of GnRH isolated from the sea lamprey, is a weak agonist of GnRH in the pituitary, but inhibits the growth of human cancer cells in micromolar concentrations. As lGnRH‐III is not a natural ligand in humans, it is possible that a more potent peptide, also containing only natural amino acids, can be synthesized. A positional scanning peptide library, focused on the variable region of the GnRH family of peptides, residues 5–8, was synthesized. The synthesized peptides were analyzed in competitive binding experiments and six new analogs were designed on the basis of the results. Their biological activities were evaluated in cell growth experiments. The only natural sequence selected was chicken GnRH‐II. The synthetic library did not yield a more potent peptide than lGnRH‐III. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.