bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene transfer into intact fetal skeletal muscle grown in vitro
Authors: Cardoso Sandra M. Pinto , Mutch Philip , Scotting Paul J. , Wigmore Peter M. 
Published: June 2004

AbstractThe development of an organ culture system for growing prenatal intercostal muscle in vitro and its use to study gene function is described. Fetal skeletal muscle is relatively inaccessible during the key stages of its development, and this method enables DNA transfections and other manipulations to be carried out. The system allows cell proliferation and differentiation to continue and also maintains the morphology and fiber types of developing muscle. Gene transfer into cultured embryonic intercostal muscle was achieved by square‐pulse electroporation of intact pieces of tissue. Expression of a marker gene (GFP) was found within 5 h and maintained for 2 days in muscle fibers and cells. The technique should enable the function of genes implicated in muscle development and disease to be studied at stages when access is difficult and in a controlled environment. Muscle Nerve 30: 87–94, 2004
Number of contractions to maintain mass and force of a denervated rat muscle
Authors: Dow Douglas E. , Cederna Paul S. , Hassett Cheryl A. , Kostrominova Tatiana Y. , Faulkner John A. , Dennis Robert G. 
Published: June 2004

AbstractWithin 5 weeks, denervated extensor digitorum longus (EDL) muscles of rats lose 66% of mass, 91% of force, and 76% of fiber cross‐sectional area (CSA). We previously determined the parameters of electrical stimulation for denervated rat EDL muscles to generate tetanic contractions sufficient to maintain mass and force close to control values. Using these parameters, we tested the hypothesis that a range exists for number of contractions per day, below and above which values for mass, maximum force, and fiber CSA are lower than values for innervated control muscles. For 5 weeks, denervated EDL muscles were stimulated to generate between 25 and 5000 contractions daily with contractions separated by constant intervals of rest, repeated 24 h per day. Force was not maintained with fewer than 200 or more than 800 contractions daily, whereas mass and fiber CSA were not maintained with fewer than 50 contractions daily. Protocols of stimulation that maintain muscle mass and force during prolonged periods of denervation may minimize problems clinically associated with denervation atrophy. Muscle Nerve 30: 77–86, 2004
Inactivity‐induced modulation of Hsp20 and Hsp25 content in rat hindlimb muscles
Authors: Huey Kimberly A. , Thresher Jeffrey S. , Brophy Colleen M. , Roy Roland R. 
Published: June 2004

AbstractDenervation decreases small heat shock protein (HSP) content in the rat soleus muscle; however, it is unknown whether this change is due to inactivity or absence of a nerve–muscle connection. Spinal cord isolation (SI) is a model of inactivity with an intact neuromuscular connection. After 7 days of SI, Hsp20 and Hsp25 levels in the soleus, plantaris, and adductor longus muscles were lower than in control rats, whereas Hsp20 was unchanged and Hsp25 increased in the tibialis anterior. The results for the soleus indicate that these small HSPs respond to inactivity and that this response is not influenced by neural activity–independent factors. Furthermore, the data indicate that these HSPs are impacted to a greater degree in muscles that are predominantly slow or have an antigravity function than in flexor muscles. Understanding the regulation of these HSPs during chronic reductions in neuromuscular activity may have valuable applications for conditions such as spinal cord injury. Muscle Nerve 30: 95–101, 2004
Corticosteroid use in the treatment of neuromuscular disorders: Empirical and evidence‐based data
Authors: Bromberg Mark B. , Carter Orly 
Published: June 2004

AbstractCorticosteroids have been used to treat neuromuscular disorders for many years. With few randomized, controlled trials, efficacy has been established primarily from empirical data. This has led to a range of treatment regimens varying in terms of initial dosing, dosing schedules, and taper rates. The goals of this review were to examine the literature for data concerning corticosteroid pharmacokinetics and for evidence‐based treatment regimens in several prototypic neuromuscular disorders. The results provide a number of sound principles for corticosteroid use, but also indicate that corticosteroid regimens and patient management are largely based on empirical clinical experiences. Muscle Nerve 30: 20–37, 2004
Annexin expression in inflammatory myopathies
Authors: Probst‐Cousin Stefan , Berghoff Corinna , Neundörfer Bernhard , Heuss Dieter 
Published: June 2004

AbstractThe pathogenesis of the inflammatory myopathies is still unclear, making their treatment largely empirical. Improved understanding of the molecular mechanisms of inflammatory muscle injury may, however, lead to the development of more specific immunotherapies. To elucidate a possible pathogenic contribution of calcium‐binding proteins such as the annexins, we immunohistochemically investigated muscle biopsy specimens from patients with dermatomyositis (10 cases), polymyositis (9 cases), and inclusion‐body myositis (4 cases), compared to control cases comprising sarcoid myopathy (3 cases), Duchenne muscular dystrophy (DMD; 4 cases), and normal muscle (3 cases). We found expression of annexins A1, A2, A4, and A6 in the vascular endothelium of all cases. Myofibers expressed annexins A5, A6, and A7 diffusely and weakly in the cytosol, whereas annexins A5 and A7 were also particularly localized to the sarcolemma. In the inflammatory myopathies, in areas of myonecrosis in DMD, and in granulomatous lesions of sarcoid myopathy, reactivity of annexins A1, A2, A4, A5, and A6 was observed in macrophages and T‐lymphocytes. Whereas the latter annexins appear to be nonspecific indicators of activation, annexin A1 upregulation may represent endogenous anti‐inflammatory mechanisms that merit further investigation. Muscle Nerve 30: 102–110, 2004
Free‐radical‐initiated copolymerization of 2‐(2‐naphthylamino)‐2‐oxo‐ethyl methacrylate with methyl methacrylate and styrene
Authors: Erol Ibrahim , Soykan Cengiz 
Published: June 2004

AbstractA naphthylamino species containing the methacrylate‐based monomer 2‐(2‐naphthylamino)‐2‐oxo‐ethyl methacrylate (NphAOEMA) was synthesized by reacting 2‐chloro‐N‐2‐naphthylacetamide (NphA) with sodium methacrylate in acetonitrile. The acetamide was prepared by reacting 1‐naphthylamine, dissolved in benzene, with chloroacetylchloride. The free‐radical‐initiated copolymerization's of NphAOEMA, with methyl methacrylate (MMA) and styrene (ST), were carried out in dimethylsulfoxide (DMSO) solution at 65 °C using 2,2′‐azobisisobutyronitrile (AIBN) as the initiator with various monomer‐to‐monomer ratios in the feed. The monomer (NphAOEMA) and copolymers were characterized from FT‐IR, 1H and 13C NMR spectral studies. The copolymer compositions were evaluated by determining the nitrogen contents in the polymers. The reactivity ratios of the monomers were determined by the application of the Fineman–Ross and Kelen–Tüdőos methods. The molecular weights (M̄w and M̄n) and polydispersity indices of the polymers were measured by using gel permation chromagtography. The thermal stabilities of the homo and copolymers were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The solubilities and inherent viscosities of the homo and copolymers were also studied. Copyright © 2004 Society of Chemical Industry
Novel thermally resistant polysilphenylenesiloxanes with a high content of vinyl substituents
Authors: Liu Yang , Imae Ichiro , Kawakami Yusuke 
Published: June 2004

AbstractPolysilphenylenesiloxanes containing various amounts of vinyl substituents (ranging from partial (25 %) to complete (100 %)) on the silicon atoms were synthesized. 29Si NMR spectroscopy revealed that they had a well defined structure, as designed. Unlike the known crystalline poly(tetramethyl‐p‐silphenylenesiloxane), all polymers containing vinyl side groups were amorphous and showed low Tgs, ranging from −52 to −32 °C (from differential scanning calorimetry (DSC)). Dynamic and isothermal thermogravimetric (TG) analyses indicated that they all possessed a greatly improved thermal stability up to 500 °C, and have ultra‐high residual yields at 1000 °C under both inert and oxidative conditions. Polysilphenylenesiloxanes containing a high percentage of vulcanizable vinyl substituents should be excellent candidates for high‐temperature polymers and have potential applications such as heat‐resistant or flame‐retardant materials. Copyright © 2004 Society of Chemical Industry
Preparation of styrene‐acrylic emulsion by using nano‐SiO2 as seeds
Authors: Zhang Faai , Wang Yunpu , Chai Chunpeng 
Published: June 2004

AbstractA styrene‐acrylic/SiO2 nanoparticle composite emulsion was prepared by using SiO2 nanoparticles as seeds. The effect of factors such as the level of nano‐SiO2, reaction temperature and ultrasound treatment of nano‐SiO2 on the stability of the polymerization reaction was investigated. Water‐resistance of the emulsion was measured. The level of nano‐SiO2 in the emulsion was determined by inductively coupled plasma (ICP) spectrometry. The particle morphology of the emulsion with nano‐SiO2 was observed with transmission electron microscopy (TEM). The kinetics of the polymerization was also studied at various temperatures and various levels of nano‐SiO2. They showed that the level of nano‐SiO2 and reaction temperature had a great influence on the monomer conversion, particle size, coagulum content and viscosity of the emulsion. Nano‐SiO2 treated by ultrasonics can increase the coagulum content greatly, but it does not improve the water resistance of the emulsion. The level of nano‐SiO2 in the emulsion was lower than the theoretical value. The reaction kinetics indicated that the level of nano‐SiO2 had less influence on the reaction rate than the reaction temperature. Even a small amount of nano‐SiO2 can decrease the reaction rate. Copyright © 2004 Society of Chemical Industry
New bound electronic states of NH+
Authors: Amero José M. , Vázquez Gabriel J. 
Published: June 2004

AbstractAb initio MRD‐CI electronic structure calculations were carried out on the NH+ cation. A basis set of DZ + POL quality augmented with Rydberg and bond functions was employed, together with an extensive treatment of electron correlation. We find four new bound electronic states of NH+, namely, three doublets (2Δ, 2Σ+, 2Σ+) and one sextet (6Π). A fifth bound electronic state, a quartet (4Π) that was reported schematically in an early SCF study (Liu, H. P. D.; Verhaegen, G. J Chem Phys 1970, 53(2), 735), is calculated for the first time over a wide range of NH distances. Electronic energies, potential energy curves, and spectroscopic constants are reported for these five states. Vertical and adiabatic excitation and ionization energies are reported, as well as vertical de‐excitation energies for emission from the novel states to lower‐lying bound states. The potential energy curve of NH2+ (X1Σ+) was also calculated to aid in the discussion of a Rydberg bound state of NH+. It is hoped that the information reported in this article will be helpful in guiding the experimental detection of these species. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Pyrrole anion addition to carbon disulfide: An ab initio study
Authors: Kobychev Vladimir B. , Vitkovskaya Nadezhda M. , Zaytseva Irina L. , Trofimov Boris A. 
Published: June 2004

AbstractThe reaction pathways of pyrrole‐1‐ and pyrrole‐2‐carbodithioate anions formation were studied using the MP2/6‐31+G* approach. No activation barrier was found on the potential energy surface for the former. By contrast, there is a significant activation barrier on the C2‐adduct formation pathway. This can cause a kinetic formation of the thermodynamically less favorable N‐adduct from unsubstituted pyrrole and CS2, while a relative instability of 2(5)‐methylpyrrole‐1‐carbodithioates results in C2‐ and C3‐adducts. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
TUNCUR: Sequential codes for semiempirical quantum chemical calculations of tunneling current
Authors: Zayets Valentin A. , Sheka Elena F. 
Published: June 2004

AbstractTUNCUR codes are aimed at a self‐consistent calculation of both equilibrated structures and electronic properties of a sample and scanning tunneling microscopy (STM) tip altogether with the tunneling current between them in the framework of the same computational scheme. Both objects are modeled by atomic clusters. Quantum chemical calculations in TUNCUR codes are provided by sequential programs, CLUSTER‐Z1 and CLUSTER‐Z2, which perform Hartree–Fock self‐consistent field semiempirical calculations in the valence sp‐ and spd‐basis, respectively. TUNCUR consists of three main blocks that provide calculations of STM recordings in two modes of operation as well as computing local density of states. All calculations are performed over a grid of variable parameters. There are two additional blocks for calculations of both the current Z‐dependence and volt‐ampere characteristic of the tunneling gap. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Enhanced post‐source decay and cross‐ring fragmentation of oligosaccharides facilitated by conversion to amino derivatives
Authors: Muzikar Jan , Mechref Yehia , Huang Yunping , Novotny Milos V. 
Published: June 2004

AbstractPost‐source decay (PSD) fragmentation of chemically or enzymatically produced aminoglycans has been evaluated through matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. Conversion of native glycans to their respective aminoglycan derivatives improved detection sensitivity of the usual fragments and promoted cross‐ring fragmentation of linear oligosaccharides, facilitating linkage recognition. The cross‐ring fragmentations for both dextrin and dextran oligosaccharides were not limited to the reducing‐end glucose moiety, as they were extended throughout the entire molecule. When the amino group was generated for N‐glycans derived from three different glycoproteins, an enhancement of PSD was observed, without a significant extent of cross‐ring fragmentation. Copyright © 2004 John Wiley & Sons, Ltd.
Electrospray ionization mass spectrometric analysis of noncovalent complexes between DNA and polyamides containing N‐methylpyrrole and N‐methylimidazole
Authors: Zhou Jiang , Yuan Gu 
Published: June 2004

AbstractElectrospray ionization mass spectrometry was utilized to investigate the noncovalent complexes between novel polyamides and DNA containing the TCCT sequence. We analyzed the noncovalent binding of the polyamides with the DNA and assessed their relative affinities and stoichiometry. The results confirm that hairpin polyamides have higher binding affinities than three‐ring polyamides. The hairpin polyamide (PyPyPyPyγPyImImPyβDp) has the highest affinity, and the β‐linked polyamide (PyPyPyβImImImβDp) shows a dominant 1:2 binding stoichiometry. Two groups of competition experiments were undertaken to compare the binding affinities of the duplex DNA with different polyamides directly. The affinity scale thus obtained for the group‐1 polyamides is PyPyPyPyγPyImImPyβDp > PyPyPyβImImImβDp ≈ PyPyPyγImImImβDp ≫ PyPyPyβDp > PyImImβDp ≈ ImImPyβDp, and the order for the group‐2 polyamides is PyPyPyγImImImβDp > PyPyPyγImImImβOEt > PyPyPyγImImImβCOOH. Copyright © 2004 John Wiley & Sons, Ltd.
Porous polymer monolith for surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry of small molecules
Authors: Peterson Dominic S. , Luo Quanzhou , Hilder Emily F. , Svec Frantisek , Fréchet Jean M. J. 
Published: June 2004

AbstractPorous poly(butyl methacrylate‐co‐ethylene dimethacrylate), poly(benzyl methacrylate‐co‐ethylene dimethacrylate), and poly(styrene‐co‐divinylbenzene) monoliths have been prepared on the top of standard sample plates used for matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry and the modified plates were used for laser desorption/ionization mass spectrometry (LDI‐MS). The hydrophobic porous surface of these monoliths enables the transfer of sufficient energy to the analyte to induce desorption and ionization prior to TOFMS analysis. Both UV and thermally initiated polymerization using a mask or circular openings in a thin gasket have been used to define spot locations matching those of the MALDI plates. The desorption/ionization ability of the monolithic materials depends on the applied laser power, the solvent used for sample preparation, and the pore size of the monoliths. The monolithic matrices are very stable and can be used even after long storage times in a typical laboratory environment without observing any deterioration of their properties. The performance of the monolithic material is demonstrated with the mass analysis of several small molecules including drugs, explosives, and acid labile compounds. The macroporous spots also enable the archiving of samples. Copyright © 2004 John Wiley & Sons, Ltd.
Statistical estimation of link availability and its impact on routing in wireless ad hoc networks
Authors: McDonald A. Bruce , Znati Taieb F. 
Published: June 2004

AbstractIn this paper, an analytical framework is developed and validated via simulation for statistical estimation of the evolution of the separation between a pair of mobile nodes in an ad hoc network. Simulation results demonstrate that path selection based on minimization of the product of the link statistic significantly outperforms minimum‐hop and fixed threshold‐based ‘path‐stability’ schemes. A hierarchical mobility model integrating the dynamic effects of velocity, group movement and geographic scope is used to generalize the results. Another significant result is the performance enhancements hold in large networks irregardless of the assumptions used for statistical estimation. The effect of merging many independent groups appears to restore independent mobility. Finally, results show that at the highest mobility levels, 90% of the longest surviving paths fail within 60 s. None of the strategies approach this optimal value. This important result suggests that optimal predictive mechanisms alone are insufficient to ensure scalable routing in ad hoc networks. Copyright © 2004 John Wiley & Sons, Ltd.
Average error rate of NCFSK with multi‐branch post‐detection switched diversity
Authors: Yang Hong‐Chuan , Alouini Mohamed‐Slim , Simon Marvin K. 
Published: June 2004

AbstractWe investigate the performance of non‐coherent frequency shift keying (NCFSK) with multi‐branch post‐detection switched diversity systems. After an appropriate statistical description of the square‐law detector output, we derive generic formulas for the symbol/bit error probability of NCFSK for both switch and stay combining (SSC) and switch and examine combining (SEC) schemes. We show that while the SSC scheme does not benefit from more than two diversity paths when the paths are identically distributed, the error performance of SEC improves as the number of antenna paths increases. We consider two detection schemes for NCFSK, one for M‐ary FSK and another limited to only BFSK. We show that the second scheme leads to lower error probability performance when both are used to detect binary signals. The mathematical formalism is illustrated with a number of selected numerical examples. Copyright © 2004 John Wiley & Sons, Ltd.
Mobility assessment on‐demand (MAOD) routing protocol for mobile ad hoc networks
Authors: Chang Ruay‐Shiung , Chen Wei‐Wen 
Published: June 2004

AbstractIn ad hoc wireless networks, the high mobility of hosts is usually a major reason for link failures. The general ‘shortest path’ based routing protocols may not lead to stable routes. In this paper, we propose a mobility assessment on‐demand (MAOD) routing protocol to select a stable route in order to enhance system throughput and performance. An error count parameter is used to judge whether a host is highly mobile. The proposed MAOD routing protocol is an on‐demand routing protocol similar to dynamic source routing (DSR). The difference between MAOD and DSR is in the path selection method. Because MAOD takes the mobility of hosts into consideration, it will select a more stable and reliable path than DSR. In comparison, DSR only considers whether this route is a shortest path or not. Finally, the system performance is analyzed by using the global mobile simulation (GloMoSim) simulator. We can observe that MAOD routing protocol outperforms DSR routing protocol especially in the high mobility environment. Copyright © 2004 John Wiley & Sons, Ltd.
High‐capacity resource sharing schemes for broadband wireless networks
Authors: Andreadis Alessandro , Benelli Giuliano , Giambene Giovanni , Pasqualetti Veronica 
Published: June 2004

AbstractThe unique capabilities of new cellular systems are expected to provide users with integrated multimedia services. Since the air interface still represents the system bottleneck, this paper proposes novel scheduling techniques to integrate efficiently the support of real‐time traffic (i.e. voice and video) and data bursty traffic under quality of service (QoS) guarantees. Prioritization among traffic classes is adopted and a polling service discipline is employed within a class, where the permission rights of each traffic source are determined on the basis of token bucket regulators. Two polling‐based approaches are compared to serve the sources of a class: (i) when a source is enabled to transmit, a burst of packets is sent at once; (ii) within the time interval destined to a traffic class, a cyclic service of the sources is allowed on a packet basis. With realistic assumptions on both radio channel conditions and protocol signaling overhead, this paper compares these two different approaches and the dynamic slot assignment++ (DSA++) scheme appeared in the literature. The obtained results highlight that our second scheme (case ii) allows increasing the number of supported video traffic sources of many units with respect to DSA++. Finally, an analytical approach has been proposed for our second polling scheme. Copyright © 2004 John Wiley & Sons, Ltd.
Discrete Rayleigh fading channel modeling
Authors: Aráuz Julio , Krishnamurthy Prashant , Labrador Miguel A. 
Published: June 2004

AbstractIn order to understand the behaviour of upper‐layer protocols and to design or fine tune their parameters over wireless networks, it is common to assume that the underlying channel is a flat Rayleigh fading channel. Such channels are commonly modeled as finite state Markov chains. Recently, hidden Markov models have also been employed to characterize these channels. In this paper, we study the different models that have been proposed along with the analysis of their validity. We start by presenting some preliminary concepts related to the modeling of the wireless communications channel. We then proceed to introduce finite state Markov channel models (FSMCs) along with the relations between them and the modulation schemes, error control protocols and channel coding. We propose and study the effects of taking into account the fading process in its characterization. We finish with a discussion on hidden Markov models for Rayleigh fading channel modeling. Copyright © 2004 John Wiley & Sons, Ltd.