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PubMed2005

[Determination of trace silver by flame atomic absorption spectrometry using chitosan enriching method].

A method for the determination of trace silver by flame atomic absorption spectrometry using chitosan enriching method has been investigated. The conditions that influence the adsorption of silver by chitosan were studied. The optimal flow rate of the sample solution was 1 mL x min(-1), and the optimal sorption (96.7%) was possible by using the systems with pH 6.0 for silver. The amount of saturated adsorption of silver in the chitosan was 97.8 mg x g(-1). Silver was eluted from the chitosan by 1 mol x L(-1) H2SO4. 100 mg x mL(-1) of Al3+, Cr3+ and 80 mg x mL(-1) of Ni2+, Cu2+, Pb2+ and Zn2+ did not disturb the determination of silver. K+, Na+, Ca2+, Mg2+ and Mn2+ did not disturb the determination of silver because they were not adsorbed by chitosan. The method has been applied to the determination of silver (1.83 microg x mL(-1)) in waste water sample with a recovery of 94.3%.

Absorption↗
PubMed2006

[Experimental study on xenogenic acellular dermal matrix incorporated with silver].

OBJECTIVE: To investigate the biological characteristics of xenogenic acellular dermal matrix( Xeno-ADM) incorporated with silver, and to observe its effect in grafting. METHODS: Xeno-ADM was prepared with 0. 25% trypsin and 0. 5% triton X-100 , and then it was immersed in 2 g/L silver nitrate solution to prepare xeno-ADM incorporated with silver. The bacterial inhibitory effect of two kinds of xeno-ADM on burn wound was determined, and the histological characteristic of the wounds was observed with optical microscope, transmission electron microscope and scanning electron microscope. The Ag+ content in the xeno-ADM incorporated with silver was measured with atomic absorption spectrometer. Twenty-seven rabbits with full-thickness skin defects on the back were randomly divided into three groups, i. e. split-thickness skin autograft only( group A, n = 9) , xeno-ADM with overlying split-thickness skin autograft( group B, n = 9) , xeno-ADM incorporated with silver with overlying split-thickness skin autograft ( group C, n = 9). The skin specimens from grafted area in each group were harvested at 2,4 and 6 post-operation weeks( POW) and examined under light microscope and transmission electron microscope. The condition of the graft, the contraction degree of the grafts and the historical changes in grafting area were observed at 2,4,6 POW. The survival rate of the grafts was calculated and the proliferative activity of the lymphocyte in each group was determined at 2 POW. RESULTS: 1. Compared with xeno-ADM, the anti-bacterial effect of xeno-ADM incorporated with silver was much better ( P < 0. 05). No epidermis was seen in both types of xenografts ,and the collagen fibers were even in size and arranged regularly, with no obvious degeneration, and the dermis was also devoid of cells and cellular components. The Ag + content in xeno-ADM incorporated with silver measured (2. 7+/-0. 7) mg/g. 2. The grafts in B and C groups presented similar color to that of normal skin at 6 POW, and it was smooth, with fine texture and no scarring. The collagen fibers was arranged regularly, and conjunction between epidermis and dermis, the structure of basal cell desmosome and semi-desmosome were well reconstructed. The grafts in A group was in dark red color, with obvious contraction, and easily broken. The contraction rate in A group at 2,4 and 6 POW were obviously higher than those in B and C groups( P < 0. 05), while no obvious difference was observed between B and C groups. ( P >0. 05). The overall survival rate of the grafts in C group at 2 POW was 91.7% , which was evidently higher than that in A (77.8%) and B (80. 6% ) groups. The lymphocyte proliferative activity exhibited no difference among A, B and C groups( P >0.05). CONCLUSION: The xeno-ADM incorporated with silver has good anti-bacterial effect. In addition, it preserves the basic tissue structure and integral collagen fiber scaffold, without cells to induce rejection, so that it can be used as an ideal dermal substitute.

Animals↗
PubMed1986

Tyrosine hydroxylase immunoreactive neurons throughout the hypothalamus receive glutamate decarboxylase immunoreactive synapses: a double pre-embedding immunocytochemical study with particulate silver and HRP.

Silver-intensified gold (SIG) particles were used for light- and electron-microscopic immunocytochemical localization of neuronal antigens, and the SIG method was compared with related heavy-metal methods for the purpose of dual ultrastructural localization of neurotransmitter-related antigens. SIG immunostaining was combined with peroxidase immunostaining to allow simultaneous study of differentially labeled tyrosine hydroxylase and glutamate decarboxylase immunoreactive neurons in the medial hypothalamus. A number of electron-dense markers that might be of use in double immunostaining for light and electron microscopy were examined, either with a simple nitrocellulose dot-blot method or on Formvar-coated slot grids. Of these, silver-intensified 5 nm colloidal gold was the most effective. Silver intensification of colloidal silver and of peroxidase reaction product also showed promise for combined LM and EM double-immunolabeling studies. Since the silver-intensification procedure used here intensifies both gold and peroxidase, in experiments involving, double staining, the silver-intensified gold procedure should be used for the first antigen and nonintensified HRP for the second. Presumptive dopaminergic neurons containing the enzyme tyrosine hydroxylase were located throughout the hypothalamus with SIG immunostaining. In the same areas where frequent tyrosine hydroxylase immunoreactive neurons were found, many axons and bouton terminals were also found with antisera against GABA or against the GABA-synthesizing enzyme glutamate decarboxylase. Areas containing cells immunoreactive for tyrosine hydroxylase and stained with SIG and axons immunoreactive for glutamate decarboxylase and stained with peroxidase included the periventricular area (A14), the arcuate nucleus (A12), the dorsomedial hypothalamus/zona incerta area (A13), the posterior hypothalamus (A11), the medial paraventricular nucleus, and dorsal to the supraoptic nucleus, in addition to the preoptic area near the third ventricle and dorsally adjacent to the anterior commissure. For comparison, the SIG procedure was also used to stain dopaminergic neurons outside the hypothalamus in the substantia nigra and ventral tegmental area. Double immunocytochemical staining of two different neurotransmitter-related antigens allowed examination with both light and electron microscopy. By virtue of a large silver shell formed around the colloidal gold particle and its adsorbed immunoglobulin or protein A, cross-reactivity of the first set of immunoreagents stained with particulate silver and a second set stained with peroxidase could be reduced or eliminated.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Silver nylon cloth: in vitro and in vivo evaluation of antimicrobial activity.

The topical agents used in burn care today, although beneficial, do have limitations, the most important of which is the failure to prevent or treat burn wound infections in patients with extensive injuries. Therefore, we evaluated the antimicrobial activity of two silver nylon fabrics (SN and HRS) on the growth of S. aureus, P. aeruginosa, and C. albicans. The theoretical advantages of these nylon fabrics over presently available silver compounds is their ability to continuously release silver ions into the burn wound as long as the material is in contact with the wound. Additionally, the release of silver from these fabrics can be augmented electrolytically. The results of these experiments indicated that both materials were microbicidal in vitro for all three test organisms. Furthermore, the antimicrobial activity could be significantly augmented by passing a weak DC current through the material, which increased the rate of release of silver ions from the fabrics. In vivo, HRS was as effective as silver sulfadiazine in preventing colonization of the burn wound. The use of silver nylon fabrics thus appears to be a promising way of delivering large quantities of silver ions into the burn wound without the potential side effects of a carrier molecule or cream.

Bandages↗
PubMed1977

Topical chemotherapy for burns using cerium salts and silver sulfadiazine.

These experimental data indicate that cerium compounds exert a measurable antimicrobial action in vitro. In vivo the simultaneous use of cerium sulfadiazine and silver sulfadiazine was more effective than silver sulfadiazine alone or the combination of cerous nitrate and silver sulfadiazine. When cerous nitrate was used clically, gram-positive bacteria predominated. In contrast, wounds exposed to silver salts alone harbor a predominately gram-negative flora. The combination of cerous nitrate and silver sulfadiazine appears to provide a broad spectrum inhibitory to both types of organisms. It is apparent that a sampling problem exists in any attempt to monitor wounds that may exceed a square meter in extent. These bacteriologic data pertain only to the surface flora. The need to culture tissue samples of burn wounds has been emphasized. Our experience, however, is that invasion of deep tissue without dense surface colonization, greater than 10(5), is infrequent. Furthermore, fragments of eschar were submitted regularly for culture; those results confirmed the surface culture findins. The characteristic yellow-green color of cerium nitrate treated eschars may results from oxidation of trivalent cerium to yellow ceric ions. Free silver and sulfadiazine ions are available also in small amounts because of limited ionization of the highly insoluble silver sulfadiazine. This might promote the in vivo formation of cerous sulfadiazine and would provide a continuous source of ionic cerium for microbial inhibition. The modification of silver sulfadiazine cream by incorporating cerous nitrate into it strikingly enhances its topical antiseptic effect in burn wounds without increasing toxicity.

Administration, Topical↗
PubMed1998

Effect of light on generation of colored silver colloids in protein solutions.

The exposure to light (20 mW/cm2, an incandescence lamp) of weakly alkaline protein solutions which contained silver nitrate and formaldehyde initiated reduction of silver ions with the subsequent generation of colored silver colloids. At light intensities lower than 0.2 mW/cm2 the generation of colored silver colloids was delayed. The rate of silver reduction depended on the protein type and on the light spectral structure. In particular, solutions which contained prealbumin, lysozyme, gamma-globulin, and transferrin were more photosensitive than solutions which contained albumin, pepsin, and beta-amylase. The formation of [Ag(NH3)2]+ complex after an addition of ammonium ions into the solutions preferentially suppressed silver reduction in the dark and under exposure to red light, thus resulting in a significant difference in the time of appearance of colored silver colloids when the solutions were exposed to violet or red light. These findings are promising for the elaboration of selective silver development of proteins in polyacrylamide gels.

Animals↗
PubMed2005

[Synthesis and SERS characterization of silver nanocubes].

Silver nanocubes were synthesized by reducing silver nitrate with ethylene glycol in the presence of poly(vinyl pyrrolidone) based on the report by Xia's group. Silver nanocubes were immobilized on silicon wafers by self-assembly processes. SERS activity of silver nanocubes was detected by using pyridine and SCN- respectively as probe molecules. The preliminary results show that the Raman intensities of pyridine and SCN- adsorbed at silver nanocubes were enhanced considerably, indicating that silver nanocubes can be used as a good SERS substrate. On the other hand, SERS combined with the probe molecule method can be used to characterize the optical property of silver nanocubes.

Ethylene Glycol↗
PubMed2000

Characterization of organometallic coordinative cluster compounds of silver by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was successfully applied to characterize the organosilver coordinative cluster compounds, silver phenylacetylide and three silver thiolates, namely, silver tertiary butylthiolate, silver 2,6-dimethylbenzenethiolate, and silver 2, 6-dichlorobenzenethiolate. Samples and dithranol matrix were finely dispersed in 1:1 tetrahydrofuran (THF)/chloroform (CHCl(3)) mixed solvent. In most cases the monomer units remained intact during ionization, and the oligomeric molecular ions were produced through silver cationization, with a general molecular ion formula [nM + Ag](+). This was further verified by the relative abundances of the isotopic peaks within the molecular ion clusters, which were in close agreement with those theoretically calculated for nM cationized with one silver ion. In the case of silver 2, 6-dichlorobenzenethiolate, in addition to the dominant [nM + Ag](+) peaks, weak peaks corresponding to the successive losses of hydrogen chloride molecules were observed. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1996

Development of a radioimmunoassay for European eel growth hormone and application to the study of silvering and experimental fasting.

A specific and sensitive homologous radioimmunoassay for eel (Anguilla anguilla L.) growth hormone (angGH) has been developed. The antiserum, raised against purified angGH and used at 1:20,000 final dilution, did not cross-react with eel prolactin or thyrotropin, carp gonadotropin II, bovine GH, or serum from hypophysectornized eel. The inhibition curves for eel pituitary extracts and serum were parallel to that of angGH standard. The ED50 value was between 1 and 2 ng/tube and the recovery of purified angGH added to the serum was about 100%. In immunocytochemical studies, the antiserum, used at 1:1000 dilution, specifically labeled the somatotrophs in the pituitaries of the glass, yellow, and silver eels. The GH contents were determined in the pituitaries of glass, yellow, and silver eels and in the serum at the yellow and silver stages. GH variations during the transformation of the yellow to silver eel were examined. The results indicated a decrease in GH production between the yellow and the silver eels, possibly related to the cessation of growth at the silver stage. In contrast to the situation in the naturally fasting silver eel, submitting yellow eels to 3 months of starvation (experimental fasting) greatly increased GH production. This suggests a variation in the regulation of GH according to the type of fasting (natural or experimental) and/or the stage of the fish (yellow or silver).

Anguilla↗
PubMed2005

Silver nanocomposite layer-by-layer films based on assembled polyelectrolyte/dendrimer.

Silver nanocomposite multilayer films were prepared through the in situ method. Multilayer thin films, prepared through the sequential electrostatic deposition of a positively charged third-generation poly(amidoamine) dendrimer (PAMAM) and negatively charged poly(styrenesulfonate) (PSS) and poly(acrylic acid) (PAA), were utilized as nanoreactors for the formation of silver nanoparticles. The silver ions were preorganized in layer-by-layer (LBL) films composed of PAMAM dendrimers and subsequently reduced with hydrogen to prepare the silver nanoparticles. The UV-vis spectrum and profilometer were used to characterize the regular growth of bilayers. UV-vis absorption from plasmon resonance at 435 nm and TEM images indicated the formation of the silver nanoparticles in the multilayer films. The silver nanocomposite LBL films were also constructed on the indium tin oxide-glass and investigated using cyclic voltammetry. The silver nanoparticles in the multilayer films have a stronger negative redox potential. The silver nanocomposite LBL films may have a potential application in the catalysis of reduction of 4-nitrophenol with sodium borohydride.

Journal Article↗
PubMed2001

Silver cluster interferences in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of nonpolar polymers.

Potential difficulties associated with background silver salt clusters during matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of nonpolar polymers are reported. Silver salt cluster ions were observed from m/z 1500 to 7000 when acidic, polar matrices, such as 2,5-dihydroxybenzoic acid (DHB), all-trans-retinoic acid (RTA) or 2-(4-hydroxyphenylazo)benzoic acid (HABA), were used for the analysis of nonpolar polymers. These background signals could be greatly reduced or eliminated by the use of nonpolar matrices such as anthracene or pyrene. Representative examples of these background interferences are demonstrated during the analysis of low molecular weight nonpolar polymers including polybutadiene and polystyrene. Nonpolar polymers analyzed with acidic, polar matrices (e.g., RTA) and silver cationization reagents can yield lower quality mass spectral results when interferences due to silver clusters are present. Replacing the polar matrices with nonpolar matrices or the silver salts with copper salts substantially improved the quality of the analytical results. In addition, it was found that silver contamination cannot be completely removed from standard stainless steel sample plates, although the presence of silver contamination was greatly reduced after thorough cleaning of the sample plate with aluminum oxide grit. Carry-over silver may cationize polymer samples and complicate the interpretation of data obtained using nonpolar matrices in the absence of added cationization reagents.

Journal Article↗
PubMed2005

Structure and bonding in silver halides. A quantum chemical study of the monomers: Ag(2)X, AgX, AgX(2), and AgX(3) (X = F, Cl, Br, I).

The molecular structure of all silver halide monomers, Ag(2)X, AgX, AgX(2), and AgX(3), (X = F, Cl, Br, I), have been calculated at the B3LYP, MP2, and CCSD(T) levels of theory by using quasirelativistic pseudopotentials for all atoms except fluorine and chlorine. All silver monohalides are stable molecules, while the relative stabilities of the subhalides, dihalides, and trihalides considerably decrease toward the larger halogens. The ground-state structure of all Ag(2)X silver subhalides has C(2)(v)() symmetry, and the molecules can be best described as [Ag(2)](+)X(-). Silver dihalides are linear molecules; AgF(2) has a (2)Sigma(g) ground state, while all of the other silver dihalides have a ground state of (2)Pi(g) symmetry. The potential energy surface (PES) of all silver trihalides has been investigated. Neither of these molecules has a D(3)(h)() symmetric trigonal planar geometry, due to their Jahn-Teller distortion. The minimum energy structure of AgF(3) is a T-shaped structure with C(2)(v)() symmetry. For AgCl(3), AgBr(3), and AgI(3), the global minimum is an L-shaped structure, which lies outside the Jahn-Teller PES. This structure can be considered as a donor-acceptor system, with X(2) acting as donor and AgX as acceptor. Thus, except for AgF(3), in the other three silver trihalides, silver is not present in the formal oxidation state 3.

Journal Article↗
PubMed2006

Toward monodispersed silver nanoparticles with unusual thermal stability.

A novel in situ autoreduction route has been developed, by which monodispersed silver nanoparticles with tunable sizes could be easily fabricated on silica-based materials, especially inside the channels of mesoporous silica (MPS). 13C CP/MAS NMR spectroscopy was employed to monitor the whole assembly process. It was demonstrated that the amino groups of APTS (aminopropyltriethoxyl silane)-modified MPS can be used to anchor formaldehyde to form novel reducing species (NHCH2OH), on which Ag(NH3)2NO3 could be in situ reduced. Monodispersed silver nanoparticles were thus obtained. In situ XRD and in situ TEM experiments were used to investigate and compare the thermal stabilities of silver nanoparticles on the external surface of silica gels (unconfined) and those located inside the channels of SBA-15 (confined). It was observed that unconfined silver nanoparticles tended to agglomerate at low temperatures (i.e., lower than 773 K). The aggregation of silver nanoparticles became more serious at 773 K. However, for those confined silver nanoparticles, no coarsening process was observed at 773 K, much higher than its Tammann temperature (i.e., 617 K). Only when the treating temperature was higher than 873 K could the agglomeration of those confined silver nanoparticles happen with time-varying via the Ostwald ripening process. The confinement of mesopores played a key role in improving the thermal stabilities of silver nanoparticles (stable up to 773 K without any observable coarsening), which is essential to the further investigations on their chemical (e.g., catalytic) properties.

Journal Article↗
PubMed2006

Density functional study of the interaction of carbon monoxide with small neutral and charged silver clusters.

CO adsorption on small neutral, anionic, and cationic silver clusters Ag(n) (n = 1-7) has been studied with use of the PW91PW91 density functional theory (DFT) method. The adsorption of CO on-top site, among various possible sites, is energetically preferred irrespective of the charge state of the silver cluster. The cationic silver clusters generally have a greater tendency to adsorb CO than the anionic and neutral silver ones, except for n = 3 and 4, and the binding energies reach a local minimum at n = 5. The binding energies on the neutral clusters, instead, reach a local maximum at n = 3, which is about 0.87 eV, probably large enough to be captured in the experiments. Binding of CO to the silver clusters is generally weaker than that to the copper and gold counterparts at the same size and charge state. This is due to the weaker orbital interaction between silver and CO, which is caused by the larger atomic radius of the silver atom. In contrast, Au atoms with a larger nuclear charge but a similar atomic radius to silver owing to the lanthanide contraction are able to have a stronger interaction with CO.

Journal Article↗
PubMed2005

Silver nanoparticle formation in microemulsions acting both as template and reducing agent.

A novel method of making silver nanoparticles in water-in-oil microemulsions using the surfactants as both the reducing agent and as the structure-directing agent is presented. Since no external strong reducing agent is used the kinetics of the formation is slow, which makes it possible to study the silver nanoparticle formation in situ. The microemulsions used were based on either the nonionic surfactant Brij30 (C12E4), which reduces the silver ion to metallic silver and is thereby partly oxidized, or mixtures of Brij30 and AOT (sodium bis(2-ethylhexyl) sulfosuccinate, where the latter does not reduce the silver ions. The influences of silver ion and nonionic surfactant concentrations on the formation kinetics of the nanoparticles were followed in situ using UV-vis spectroscopy, and both parameters were found to have a big influence. The microemulsion droplet's size, size distribution, and shape were examined by small-angle X-ray scattering (SAXS), and the formed silver nanoparticles were studied using both transmission electron microscopy and SAXS. The SAXS measurements showed that the presence of silver nitrate does not affect the microemulsion systems noticeably and that the droplet's size and shape are retained during the particle formation. It is shown that the size and morphology of the particles do not directly follow the shape and size of the microemulsion droplets even though there is a relation between the droplet size and the radii of the formed particles.

Journal Article↗
PubMed1987

Effect of silver ions on ethylene biosynthesis by tomato fruit tissue.

Mature-green tomato fruit (Lycopersicon esculentum Mill.) were treated asymmetrically with 2 millimolar silver thiosulfate (STS) through a cut portion of the peduncle while still attached to the plant. One-half of the fruit received silver and remained green while the other half ripened normally and was silver-free (less than 0.01 parts per billion). Harvested mature-green fruit were also treated with STS through the cut pedicel. Green tissue from silver-treated fruit had levels of 1-aminocyclopropane-1-carboxylic acid (ACC, the immediate ethylene precursor) slightly less or similar to that of turning or red-ripe tissue from the same fruit, and similar to that of mature-green tissue from control fruit. Ethylene production was higher in green tissue from silver-treated fruit than from either red tissue from the same fruit, or mature-green tissue from control fruit. By inhibiting ACC synthesis with aminoethoxyvinyl glycine, and by applying ACC +/- silver to excised disks of pericarp tissue from control or silver-treated tomatoes, we showed that short-term silver treatment did not affect the biological conversion of ACC to ethylene, while long-term treatment stimulated both the conversion of ACC to ethylene and the synthesis of ACC.

Journal Article↗
PubMed2006

Temperature dependence of the silver distribution in the crystal structure of natural pearceite, (Ag,Cu)16(As,Sb)2S11.

The crystal structure of the mineral pearceite, (Ag,Cu)16(As,Sb)2S11, has been solved and refined at 300, 120 and 15 K. At room temperature pearceite crystallizes with trigonal symmetry, space group P3m1; the refinement of the structure leads to a residual factor of R = 0.0464 for 1109 independent observed reflections and 92 variables. The crystal structure consists of sheets stacked along the c axis. The As atoms form isolated (As,Sb)S3 pyramids, which typically occur in sulfosalts, copper cations link two S atoms in a linear coordination, and the silver cations are found in a fully occupied position and in various sites corresponding to the most pronounced probability density function locations (modes) of diffusion-like paths. These positions correspond to low-coordination (2, 3 and 4) sites, in agreement with the preference of silver for such environments. d10 silver-ion distribution has been determined by means of a combination of a Gram-Charlier description of the atomic displacement factors and a split-atom model. To analyse the crystal chemical behaviour of the silver cations as a function of temperature, a structural study was carried out at 120 K (R = 0.0450). The refinement indicates that the mineral exhibits the same structural arrangement as the room-temperature structure (space group P3m1) and shows that the silver cations are still highly disordered. In order to investigate a possible ordering scheme for the silver cations, a data collection at ultra-low temperature (15 K) was performed. The structural skeleton was found to be similar to that of the room-temperature and 120 K atomic structures, but the best solution was achieved with a fully split-atom model of five silver positions, giving an R value of 0.0449 for 651 observed reflections and 78 parameters. Although the silver cation densities condense into better defined modes, the joint probability density function still exhibits a strong overlapping of neighbouring sites.

Journal Article↗
PubMed2001

Slow muscle power output of yellow- and silver-phase European eels (Anguilla anguilla L.): changes in muscle performance prior to migration.

Eels swim in the anguilliform mode in which the majority of the body axis undulates to generate thrust. For this reason, muscle function has been hypothesised to be relatively uniform along the body axis relative to some other teleosts in which the caudal fin is the main site of thrust production. The European eel (Anguilla anguilla L.) has a complex life cycle involving a lengthy spawning migration. Prior to migration, there is a metamorphosis from a yellow (non-migratory) to a silver (migratory) life-history phase. The work loop technique was used to determine slow muscle power outputs in yellow- and silver-phase eels. Differences in muscle properties and power outputs were apparent between yellow- and silver-phase eels. The mass-specific power output of silver-phase slow muscle was greater than that of yellow-phase slow muscle. Maximum slow muscle power outputs under approximated in vivo conditions were 0.24 W kg(-1) in yellow-phase eel and 0.74 W kg(-1) in silver-phase eel. Power output peaked at cycle frequencies of 0.3--0.5 Hz in yellow-phase slow muscle and at 0.5--0.8 Hz in silver-phase slow muscle. The time from stimulus offset to 90 % relaxation was significantly greater in yellow- than in silver-phase eels. The time from stimulus onset to peak force was not significantly different between life-history stages or axial locations. Yellow-phase eels shifted to intermittent bursts of higher-frequency tailbeats at a lower swimming speed than silver-phase eels. This may indicate recruitment of fast muscle at low speeds in yellow-phase eels to compensate for a relatively lower slow muscle power output and operating frequency.

Animals↗