Effects of dietary plant polyphenols and seaweed extract mixture on male-rabbit semen: Quality traits and antioxidant markers

Feed additive consisting of polysaccharides from brown seaweeds plus phenolic acid, hydroxycinnamic acids, tannins, and flavonoids from plant extracts, was used as rabbit food supplement. Main aim of the study was to determine the effect of natural mix of marine and freshwater seaweed polyphenols on selected reproductive characteristics of male rabbits during the 90-days experiment. Natural mix was incorporated in feed-pellets for rabbits in two different concentrations – 0.3% (T1 group) and 0.6% (T2 group), compared with a control group (C group). In experimental groups a significant increase of concentration of calcium during first 30 days of supplementation was found. An increase of alanine aminotransferase, glutathione peroxidase and ferric reducing ability of plasma and a decrease in aspartate aminotransferase after 90 days were recorded in the same groups. Except for that we noticed decrease of semen distance of curved line and velocity of curved line after 30 days though only while being supplemented with 0.6% proportion of seaweed polyphenols in feed mixture. Based on the results it can be stated that the natural mix in the tested levels do not show adverse effect on male rabbit reproductive parameters, and an improvement of antioxidant status was observed. The feed additives can have a very important effect on growth, health and development of animals in general as it supplies the with the much-needed minerals, nutritional substances and antioxidants, on which we focused in our study

Lippia citriodora (verbascoside) extract supplementation: Effect on rabbit semen quality in vivo and in vitro

Verbascoside, the main component of Lippia citriodora extract, is one of the most powerful free radical scavengers exhibiting a wide biological activity. In in vivo study 20 adult New Zealand white rabbit bucks were divided into two homogeneous groups, one control (CON) and one verbascoside-supplemented (0.1%) in feed mixture (EXP) and later in vitro effects of verbascoside on the motility aspects of rabbit spermatozoa were analysed. The spermatozoa concentration, ejaculate volume, spermatozoa motility, progressive motility, distance parameters, velocity parameters and type of spermatozoa movement were negatively affected by Lippia citriodora leaves extract after the first 4 weeks of dietary treatment, till the end of experiment (8 weeks). Four weeks after the suspension of feed additive supplementation, all spermatozoa traits values returned to the normality, and in line with CON group. For in vitro findings, ejaculates from 10 male New Zealand white bucks were collected using an artificial vagina. Then it was diluted in physiological saline solution containing different concentrations of verbascoside at the concentration of 0, 0.0024, 0.0219, 0.157, 120.0 mg/ml (Ctrl, VB1, VB2, VB3, VB4 groups, respectively), using a dilution ratio of 1: 4. The obtained data proved that verbascoside at the concentration of 0.0024 and 0.0219 mg/ml had no adverse effect on spermatozoa. Additionally, we found that verbascoside at higher concentrations (0.157 and 120.0 mg/ml) significantly altered all the motility parameters analysed in the experiment. In conclusion a possible negative effect of verbascoside supplementation into feed mixture (0.1%) on semen quality parameters in rabbit bucks as well as in vitro can be stated, obviously considering that target organs of antioxidant activities of phenylpropanoid glycosides are various. In addition it has to be emphasized that the extract showed a reversible action, since the semen traits of treated animals returned to the normality after the dietary administration period

Direct observation of delithiation as the origin of analog memristance in LixNbO2

The discovery of analog LixNbO2 memristors revealed a promising new memristive mechanism wherein the diffusion of Li+ rather than O2- ions enables precise control of the resistive states. However, directly correlating lithium concentration with changes to the electronic structure in active layers remains a challenge and is required to truly understand the underlying physics. Chemically delithiated single crystals of LiNbO2 present a model system for correlating lithium variation with spectroscopic signatures from operando soft x-ray spectroscopy studies of device active layers. Using electronic structure modeling of the x-ray spectroscopy of LixNbO2 single crystals, we demonstrate that the intrinsic memristive behavior in LixNbO2 active layers results from field-induced degenerate p-type doping. We show that electrical operation of LixNbO2-based memristors is viable even at marginal Li deficiency and that the analog memristive switching occurs well before the system is fully metallic. This study serves as a benchmark for material synthesis and characterization of future LixNbO2-based memristor devices and suggests that valence change switching is a scalable alternative that circumvents the electroforming typically required for filamentary-based memristors

Studies of minority carrier diffusion length increase in p-type ZnO : Sb

Minority electron diffusion length was measured in p-type, Sb-doped ZnO as a function of temperature using the electron beam induced current technique. A thermally induced increase of electron diffusion length was determined to have an activation energy of 184 +/- 10 meV. Irradiation with a low energy (5 kV) electron beam also resulted in an increase of diffusion length with a similar activation energy (219 +/- 8 meV). Both phenomena are suggested to involve a Sb-Zn-2V(Zn) acceptor complex. Saturation and relaxation dynamics of minority carrier diffusion length are explored. Details of a possible mechanism for diffusion length increase are presented

Doping level dependence of electron irradiation-induced minority carrier diffusion length increase in Mg-doped GaN

The electron irradiation-induced increase of minority carrier diffusion length was studied as a function of hole concentration in Mg-doped GaN. Variable-temperature electron beam induced current measurements yielded activation energies of 264, 254, 171, and 144 meV for samples with hole concentrations of 2x10(16), 9x10(16), 3x10(18), and 7x10(18) cm(-3), respectively. This carrier concentration dependence of the activation energy for the effects of electron irradiation was found to be consistent with Mg acceptors, indicating the involvement of the latter levels in the irradiation-induced diffusion length increase

Cathodoluminescence studies of carrier concentration dependence for the electron-irradiation effects in p-GaN

Electron-irradiation increase of nonequilibrium carrier lifetime was studied as a function of hole concentration in Mg-doped GaN. Temperature-dependent cathodoluminescence (CL) studies yielded activation energies of 344, 326, 237, and 197 meV for samples with hole concentrations of 2x10(16), 9x10(16), 3x10(18), and 7x10(18) cm(-3), respectively. The systematic decay of activation energy with carrier concentration was found to be consistent with Mg acceptors, indicating the involvement of the latter levels in irradiation-induced lifetime changes

Carrier concentration dependence of acceptor activation energy in p-type ZnO

The characteristics of an acceptor level in Sb-doped, p-type ZnO were studied using cathodoluminescence (CL) spectroscopy as a function of hole concentration. Variable-temperature CL measurements allowed us to estimate the activation energy of an Sb-related acceptor from temperature-induced decay of CL intensity. The values of activation energy of about 212 +/- 28, 175 +/- 20, 158 +/- 22, and 135 +/- 15 meV were obtained for samples with carrier concentrations of 1.3x10(17), 6.0x10(17), 8.2x10(17), and 1.3x10(18) cm(-3), respectively. The involvement of acceptor levels is supported by the temperature-dependent hole concentration measurements. The possible origins of the strong temperature dependence are discussed