bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conceptual modelling of sand bars morphodynamics for a microtidal beach (Sète, France)
Authors: Certain Raphaël , Barusseau Jean-Paul 
Published: September 2005

Abstract
The sandy littoral of Sète, with its barred shoreface, is one of the three studied sites of the thematic action “Morphodynamics of sandy beaches” of the French Programme National d’Environnement Côtier (PNEC), selected because of its microtidal wave-dominated characteristics and of the long time series of available data. During the PNEC program, the principal results obtained show that the morphological evolution of the sedimentary bars can be synthesized according to two conceptual models, in reaction to hydrodynamic variability. (1) The model of “oscillation around a position of equilibrium” (O.P.E) defines the usual mode of behaviour of the bars, with an alternation of shoreward and seaward movements. The bars migrate seaward during storms and shoreward when the energy conditions decrease. This oscillation is expressed with several rhythms. (i) During the main phases of the bar evolution, which are long periods during which the bars present the same geometrical characters. The passage from one phase to the other occurs when a 4 m significant height storm happens. (ii) At the seasonal scale, which is well illustrated by the behaviour of the inner bar: during summer, when the conditions of agitation are weak, the bar aggregates punctually with the shore; when the conditions of agitation increase in autumn the inner bar is reformed and moved seaward. (2) The model of “Net Offshore Migration” (N.O.M) points to the tendency of the bars to retreat under the effect of paroxysmal events (storms with a 20 to 50 yrs return time) being a prelude to their degeneration. From the former position of equilibrium, the outer bar strongly moves seaward and drops following heavy swell. Instead of moving to the coast according to the O.P.E model, the outer bar loses material that is recovered by the inner bar and degenerates. The inner bar, exposed to the swell, then moves seaward to replace the initial outer bar, a new inner bar being created at the coast. A few years after, the standard pattern is restored. These results are compared with those described in the literature.
Microbially mediated phosphatization in the Neoproterozoic Doushantuo Lagerstätte, South China
Authors: Hubert Benoìt , Álvaro J. Javier , Chen Jun-Yuan 
Published: September 2005

Abstract
Detailed petrographic and geochemical studies of pore-filling cements and replaced (epigenic) membranes of some organic-walled microorganisms preserved in the Neoproterozoic Doushantuo Lagerstätte (China) are based on an energy dispersive system (EDS) of elemental mapping attached to backscattered MEB. Their microcrystalline apatite (collophane) occurs predominantly as phosphatized microbial pseudomorphs: phosphatic crusts of chasmolithic bio-films (or microstromatolites) and globular clusters occur lining intraparticular porosities. Three major pre-compactional cement types are identified on algal thalli, embryos and vase-shaped microfossils: epigenic collophane (by replacement of membranes), polyphasic filling of collophane and crystalline apatite and fluorapatite within intraparticular porosities (some of them microbially mediated), and latest carbonate precipitation filling the remaining intraparticular porosities (preserved at present as dedolomitized calcite). P2O5 concentration has a clear peak in the microbial pseudomorphs and uniformly low concentrations elsewhere, whereas MgO, Na2O, K2O and SiO2 show a slight increase in concentration through successive cements. These geochemical trends evidence a slight change of pore fluids accompanied by a final rise in pH, presumably following the main interval of decay, which favoured precipitation of CaCO3 postdating that of apatite.
Novel type of two‐impinging‐jets reactor for solid–liquid enzyme reactions
Authors: Dehkordi Asghar Molaei 
Published: September 2005

AbstractThe isomerization of D‐glucose to D‐fructose using the immobilized glucose isomerase, as a typical model system of solid–liquid enzyme reactions has been carried out in a novel type of two‐impinging‐jets reactor (TIJR), which is characterized by a rotating inner cylinder in a stationary one. Because of the impinging process, turbulence, and complex trajectory of the solid particles within the reactor, the fractional conversion of glucose obtained in the TIJR increased dramatically compared to that obtained by conventional reaction systems. A compartment model was considered to describe the pattern of flow [residence time distribution (RTD) of solid particles] within the TIJR. Considering such a flow pattern, a stochastic model for the RTD of the solid particles was developed using Markov chains models. The latter was correlated with the experimental RTD data, obtained by using a tracer analysis technique. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Exposure to a moderate intensity static magnetic field enhances the hypotensive effect of a calcium channel blocker in spontaneously hypertensive rats
Authors: Okano Hideyuki , Ohkubo Chiyoji 
Published: September 2005

AbstractWe investigated the combined effects of a moderate intensity static magnetic field (SMF) and an L‐type voltage‐gated Ca2+ channel blocker, nicardipine in stroke‐resistant spontaneously hypertensive rats during the development of hypertension. Five‐week‐old male rats were exposed to SMF intensity up to 180 mT (Bmax) with a peak spatial gradient of 133 mT/mm for 14 weeks. Four experimental groups of 14 animals each were examined: (1) sham exposure with intraperitoneal (ip) saline injection (control); (2) SMF exposure with ip saline injection (SMF); (3) sham exposure with ip nicardipine injection (NIC); (4) SMF exposure with ip nicardipine injection (SMF + NIC). A disc‐shaped permanent magnet or a dummy magnet was implanted in the vicinity adjacent to the left carotid sinus baroreceptor region in the neck of each rat. Nicardipine (2 mg/kg ip) was administered three times a week for 14 weeks, and then 15 min after each injection, arterial blood pressure (BP), heart rate (HR), baroreflex sensitivity (BRS), skin blood flow (SBF), skin blood velocity (SBV), plasma nitric oxide (NO) metabolites (NOx = NO + NO), plasma catecholamine levels and behavioral parameters of a functional observational battery were monitored. The action of nicardipine significantly decreased BP, and increased HR, SBF, SBV, plasma epinephrine and norepinephrine in the NIC group compared with the control respective age‐matched group without changing plasma NOx levels. Neck exposure to SMF alone for 5–8 weeks significantly suppressed or retarded the development of hypertension together with increased BRS in SMF group. Furthermore, the exposure to SMF for 1–8 weeks significantly promoted the nicardipine‐induced BP decrease in the SMF + NIC group compared with the respective NIC group. Moreover, the SMF induced a significant increase in plasma NOx in the nicardipine‐induced hypotension. There were no significant differences in any of the physiological or behavioral parameters measured between the SMF + NIC and the NIC groups, nor between the SMF and the control groups. These results suggest that the SMF may enhance nicardipine‐induced hypotension by more effectively antagonizing the Ca2+ influx through the Ca2+ channels compared with the NIC treatment alone. Furthermore, the enhanced antihypertensive effects of the SMF on the nicardipine‐treated group appear to be partially related to the increased NOx. Theoretical considerations suggest that the applied SMF (Bmax 40 mT, 0 Hz) can be converted into a changing magnetic field (Bmax 30–40 mT, 5.7–6.5 Hz or 7.5–8.3 Hz) in the baroreceptor region by means of the carotid artery pulsation. Therefore, we propose that the moderate intensity changing magnetic field, i.e., the magnetic field modulated by the pulse rate, may influence the activity of baroreceptor and baroreflex function. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Metabolic pathway of magnetized fluid‐induced relaxation effects on heart muscle
Authors: Ayrapetyan Gayane , Papanyan Alexander , Hayrapetyan Hovik , Ayrapetyan Sinerik 
Published: September 2005

AbstractThe effect of magnetized physiological solution (MPS) on isolated, perfused snail heart muscle contractility, 45Ca uptake and intracellular level of cAMP, and cGMP was studied. The existence of the relaxing effect of MPS on heart muscle at room temperature (22 °C) and its absence in cold medium (4 °C) was shown. The MPS had a depressing effect on 45Ca uptake by muscles and intracellular cAMP content and an elevating effect on intracellular cGMP level. It is suggested that the relaxing effect of MPS on heart muscle is due to the decrease of intracellular Ca ions as the result of activation of cGMP‐dependent Ca efflux. The MPS induced decrease of intracellular cAMP content can be considered as a consequence of intracellular Ca loss, leading to the Na + K‐ATPase reactivation, and causing the decrease of the intracellular level of ATP, serving as a substrate and positive modulator of cyclase activity. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Pulsed electric field exposure of insulin induces anti‐proliferative effects on human hepatocytes
Authors: Li Lejun , Dai Yuwen , Xia Ruohong , Chen Shude , Qiao Denjiang 
Published: September 2005

AbstractThe purpose of this study was to examine the effects and the mechanism of a pulsed electric field (PEF) on insulin and its subsequent mediation of proliferative changes in human hepatocytes in vitro. The PEF, the electric field intensity coupled into the culture medium, was about 0.7 V/m with a repeating frequency of 50 Hz. Insulin solution was exposed to PEF for 20 min and added to the culture medium of human hepatocytes. Combining fluorescence spectroscopy, immunocytochemistry, microarrays, RT‐PCR and MTT, several important events of the insulin signaling pathways were investigated, including ligand‐receptor binding capacity, intracellular tyrosine phosphorylation level, gene transcription, and cell proliferation. PEF produced a conformational change of insulin molecule. The binding capacity of insulin to its receptors was reduced to 87% of the control level after PEF treatment, and the average intracellular tyrosine phosphorylation level decreased by 11%. The expression of 55 of 12000 genes examined was modified, including an increase in the expression of human tyrosine phosphatase and the small GTP‐binding protein. Based on these results, a mechanism is proposed to explain the bio‐effects of PEF on hepatic cell proliferation through the insulin signaling pathway. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Numerical assessment of induced ELF Currents in the human head due to the battery current of a digital mobile phone
Authors: Ilvonen Sami , Sihvonen Ari‐Pekka , Kärkkäinen Kimmo , Sarvas Jukka 
Published: September 2005

AbstractIn this study, the extremely low frequency (ELF) fields induced in the human head by the battery currents of a mobile phone are considered. The magnetic field induced by the phone was measured, and this data was used to calculate the resulting currents induced in the human head and brain. Both the finite element method (FEM) and finite integration technique (FIT) were used for numerical computations. The computed current density values were then compared with the guidelines given by the International Commission on Non‐Ionising Radiation Protection (ICNIRP). The comparison showed that the computed exposure is well within the limits of those guidelines. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Effect of a low intensity magnetic field on human motor behavior
Authors: Legros Alexandre , Beuter Anne 
Published: September 2005

AbstractExtremely low frequency (ELF) magnetic fields (MF) are omnipresent in our modern daily environment, but their effects on humans are still not clearly established. The aim of this study was to determine the effect of a 50 Hz, 1000 µT MF centered at the level of the head on human index finger micro‐displacements. Twenty‐four men recruited among the personnel of the French company, Electricité de France (EDF), completed the experiment. Their postural and kinetic tremors were recorded under four “field‐on” and four “field‐off” conditions, each tested during a real and a sham sequence. Eight postural and four kinetic tremor characteristics were calculated on recorded time series and were used for statistical analysis. No effect of the MF was found for kinetic tremor. Concerning postural tremor, the proportion of oscillations at low frequencies (between 2 and 4 Hz) was higher during the real than during the sham exposure sequence (P < .05). It suggests that MF could have a subtle delayed effect on human behavior, which is clearly not pathological. These results should be taken into account for the establishment of new exposure limits. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Timing of pulsed electromagnetic field stimulation does not affect the promotion of bone cell development
Authors: Hannay Gwynne , Leavesley David , Pearcy Mark 
Published: September 2005

AbstractPulsed electromagnetic field (PEMF) devices have been used clinically to promote the healing of surgically resistant fractures in vivo. However, there is a sparsity of data on how the timing of an applied PEMF effects the osteogenic cells that would be present within the fracture gap. The purpose of this study was to examine the response of osteoblast‐like cells to a PEMF stimulus, mimicking that of a clinically available device, using four protocols for the timing of the stimulus. The PEMF signal consisted of a 5 ms pulse burst (containing 20 pulses) repeated at 15 Hz. Cultures of a human osteosarcoma cell line, SaOS‐2, were exposed to the four timing protocols, each conducted over 3 days. Protocol one stimulated the cells for 8 h each day, protocol two stimulated the cells for 24 h on the first day, protocol three stimulated the cells for 24 h on the second day, and protocol four stimulated the cells for 24 h on the third day. Cells were seeded with either 25 000 or 50 000 cells/well (24‐well cell culture plates). All assays showed reduced proliferation and increased differentiation (alkaline phosphatase activity) in the PEMF stimulated cultures compared with the control cultures, except for protocol four alkaline phosphatase measurements. No clear trend was observed between the four protocols; however this may be due to cell density. The results indicated that an osteoblast‐like cell line is responsive to a 15 Hz PEMF stimulus, which will stimulate the cell line to into an increasing state of maturity. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Do electromagnetic fields interact with electrons in the Na,K‐ATPase?
Authors: Blank Martin 
Published: September 2005

AbstractThe effects of low frequency electric and magnetic fields on several biochemical systems, including the Na,K‐ATPase, indicate that electromagnetic (EM) fields interact with electrons. The frequency optima for two enzymes in response to EM fields are very close to their turnover numbers, suggesting that these interactions directly affect reaction rates. Nevertheless, generally accepted ideas about Na,K‐ATPase function and ion transport mechanisms do not consider interactions with electrons. To resolve the clash of paradigms, we hypothesize interaction with transient electrons and protons that arise from flickering of H‐bonds in the hydrated protein. These transient charges in the enzyme could provide a trigger for the sequence of conformation changes that are part of the ion transport mechanism. If the distributions of transient electrons and protons in the membrane are affected by their concentration and the membrane potential, as expected from electric double layer theory, this can account for the different effects of low frequency electric and magnetic fields, as well as for the observation that membrane hyperpolarization reverses the ATPase reaction to generate ATP. Bioelectromagnetics © 2005 Wiley‐Liss, Inc.
Analysis of the structure of magnetic fields that induced inhibition of stimulated neurite outgrowth
Authors: Binhi V.N. , Blackman C.F. 
Published: September 2005

AbstractThe important experiments showing nonlinear amplitude dependences of the neurite outgrowth in pheochromocytoma nerve cells due to ELF magnetic field exposure had been carried out in a nonuniform ac magnetic field. The nonuniformity entailed larger than expected variances in magnetic field magnitudes associated with specific levels of biological effects, thereby evoking a question about validity of the interpretations formulated for the case of a uniform field. In this work, we calculate the relative value of nonuniformity and deviations in ac magnetic field. It is shown that these factors do not affect the main conclusion in the original papers about the form of the amplitude dependence of the observed biological effect. Bioelectromagnetics Published 2005 Wiley‐Liss, Inc.
Microbial transformations 59: First kilogram scale asymmetric microbial Baeyer‐Villiger oxidation with optimized productivity using a resin‐based in situ SFPR strategy
Authors: Hilker Iris , Wohlgemuth Roland , Alphand Véronique , Furstoss Roland 
Published: September 2005

AbstractThis study is demonstrating the scale up of asymmetric microbial Baeyer‐Villiger oxidation of racemic bicyclo[3.2.0]hept‐2‐en‐6‐one (1) to the kilogram scale using a 50 L bioreactor. The process has been optimized with respect to bottlenecks identified in downscaled experiments. A high productivity was obtained combining a resin‐based in situ substrate feeding and product removal methodology (in situ SFPR), a glycerol feed control, and an improved oxygenation device (using a sintered‐metal sparger). As expected both regioisomeric lactones [(−)‐(1S,5R)‐2 and (−)‐(1R,5S)‐3] were obtained in nearly enantiopure form (ee > 98%) and good yield. This represents the first example of such an asymmetric Baeyer‐Villiger biooxidation reaction ever operated at that scale. This novel resin‐based in situ SFPR technology therefore clearly opens the way to further (industrial) upscaling of this highly valuable (asymmetric) reaction. © 2005 Wiley Periodicals, Inc.
Physical and biological performance of a novel block copolymer nerve guide
Authors: Lietz M. , Ullrich A. , Schulte‐Eversum C. , Oberhoffner S. , Fricke C. , Müller H.W. , Schlosshauer B. 
Published: September 2005

AbstractAlthough the ability to regenerate is evident in the nervous system, lesioned neurites are unable to cross gaps in neuronal pathways. In order to bridge gaps, guiding cues are essential to direct neurite regrowth. To overcome many of the shortcomings of polymer‐based nerve guides, we developed a bioresorbable nerve guide composed of a novel trimethylene carbonate‐caprolacton block copolymer (TMC‐CL). Pore formation was controlled by using special solvent/precipitation media compositions in combination with the pore forming agent poly ethylene glycol (PEG). NMR spectroscopy, shear force‐, compression‐, and permeation assays were used for conduit characterization. The polymer conduit has a semipermeable wall with submicron pores to allow free metabolite/drug exchange. In order to investigate the principle of temporally controlled expression of therapeutic proteins in nerve guides, Neuro‐2a cells were genetically engineered to express the reporter gene product green fluorescent protein (GFP) under the control of the Tet‐On system. When these transduced cells were encapsulated in nerve guides, GFP expression could be induced for days by adding the antibiotic tetracycline derivative doxycycline to the nerve guide environment. Furthermore, encapsulated dorsal root ganglia (DRG) produced long neurites in vitro. In subsequent in vivo experiments, nerve guides filled with Schwann cells (SC) were implanted into lesioned spinal cords of adult rats. Regeneration of spinal cord axons into nerve guides was promoted by co‐implanted Schwann cells. The data suggest that the novel TMC‐CL nerve guides provide a promising tool for neuroregeneration. © 2005 Wiley Periodicals, Inc.
Reversible permeabilization using high‐intensity femtosecond laser pulses: Applications to biopreservation
Authors: Kohli Vikram , Acker Jason P. , Elezzabi Abdulhakem Y. 
Published: September 2005

AbstractNon‐invasive manipulation of live cells is important for cell‐based therapeutics. Herein we report on the uniqueness of using high‐intensity femtosecond laser pulses for reversibly permeabilizing mammalian cells for biopreservation applications. When mammalian cells were suspended in a impermeable hyperosmotic cryoprotectant sucrose solution, femtosecond laser pulses were used to transiently permeabilize cells for cytoplasmic solute uptake. The kinetics of cells exposed to 0.2, 0.3, 0.4, and 0.5 M sucrose, following permeabilization, were measured using video microscopy, and post‐permeabilization survival was determined by a dual fluorescence membrane integrity assay. Using appropriate laser parameters, we observed the highest cell survival for 0.2 M sucrose solution (>90%), with a progressive decline in cell survival towards higher concentrations. Using diffusion equations describing the transport of solutes, the intracellular osmolarity at the inner surface of the membrane (x = 10 nm) and to a diffusive length of x = 10 μm was estimated, and a high loading efficiency (>98% for x = 10 nm and >70% for x = 10 μm) was calculated for cells suspended in 0.2 M sucrose. This is the first report of using femtosecond laser pulses for permeabilizing cells in the presence of cryoprotectants for biopreservation applications. © 2005 Wiley Periodicals, Inc.
Bean Yellow Dwarf Virus replicons for high‐level transgene expression in transgenic plants and cell cultures
Authors: Zhang Xiuren , Mason Hugh 
Published: September 2005

AbstractA novel stable transgenic plant expression system was developed using elements of the replication machinery of Bean Yellow Dwarf Virus (BeYDV). The system contains two transgenes: 1) The BeYDV replicon vector with an expression cassette flanked by cis‐acting DNA elements of BeYDV, and 2) The viral replication initiator protein (Rep) controlled by an alcohol‐inducible promoter. When Rep expression was triggered by treatment with ethanol, it induced release of the BeYDV replicon from stably integrated T‐DNA and episomal replication to high copy number. Replicon amplification resulted in substantially increased transgene mRNA levels (up to 80‐fold) and translation products (up to 10‐fold) after induction of Rep expression by ethanol treatment in tobacco NT1 cells and leaves of whole potato plants. Thus, the BeYDV stable transformant replicon system is a powerful tool for plant‐based production of recombinant proteins. © 2005 Wiley Periodicals, Inc.
Trap and release of oligonucleotide using pH‐responsive amphoteric particle prepared by interfacial polymerization in W/O miniemulsion system
Authors: Taira Shu , Du Yong‐Zhong , Kodaka Masato 
Published: September 2005

AbstractNovel amphoteric particles are prepared by an interfacial polyaddition reaction of ethylene glycol diglycidyl ether (EGDGE) and L‐lysine in a water‐in‐oil (W/O) miniemulsion system. The ζ‐potential of the copolymer particle as a function of pH indicates a sigmoid curve with an isoelectric point at pH 8.7 due to the existence of secondary amino and carboxyl groups in the copolymer chain. The obtained amphoteric particle bears positive charge under pH 8.7 and negative charge over pH 8.7. This specific property of the pH‐responsive amphoteric particle is employed to separate single‐stranded DNA (ssDNA). The trapped ssDNA at pH 7.0 is almost released by changing pH to 11.0, which can be carried out repeatedly. © 2005 Wiley Periodicals, Inc.