This study was carried out to determine the effects of growth factors (epidermal growth factor, transforming growth factors-alpha and -beta 1, basic fibroblast growth factor, insulin), gonadotrophins (LH, FSH), and fetal bovine serum added to TCM199 medium on cumulus expansion and fertilization during in vitro maturation, and on subsequent embryonic development of bovine cumulus cell-enclosed oocytes. Epidermal growth factor, transforming growth factor-alpha, LH and FSH enhanced cumulus expansion and oocyte fertilizability. No significant effect was achieved with transforming growth factor-beta 1 nor with basic fibroblast growth factor. No additive stimulation on cumulus expansion and oocyte fertilizability was observed when epidermal growth factor was combined with LH or FSH. The addition of either epidermal growth factor or transforming growth factor-alpha to the maturation medium increased the number of fertilized ova that developed to the blastocyst stage. These results demonstrate the potential use of epidermal growth factor and transforming growth factor-alpha in obtaining high quality mature bovine oocytes for in vitro fertilization.

The thermoelectric properties of Y-doped polycrystalline SrTiO3 (Sr1-x Y x TiO3) are measured from 10 K to 900 K. The Y component is doped up to the solubility limit of Sr1-x Y x TiO3, x=0.1. The Y-doped polycrystalline samples show a low resistivity, ∼1 ×10-5 Ω·m and a large absolute value of the Seebeck coefficient, ∼150 µV/K, at room temperature. Consequently, they have a high power factor, 1.2 ×10-3 W/mK2, defined as PF=S 2/ρ, where S is the Seebeck coefficient and ρ is the resistivity. Furthermore, we observe a decrease in the thermal conductivity of SrTiO3 due to phonon scattering by the Y dopant.

A bicarbonate-stimulated adenylyl cyclase (AC) activity was found in ocular ciliary processes, which secrete the aqueous humor of the eye. Other fluid-transporting tissues also showed HCO3(-)-stimulated AC activity. Relative to basal, the response to 10 mM NaHCO3 was greatest in the particulate fraction of bovine ciliary processes, followed by bovine corneal endothelium, bovine choroid plexus, and rat kidney (medulla and cortex). However, no activity was detectable in bovine retina, cerebral cortex, or cerebellum. The activity in ciliary processes was present only in the particulate fraction, was supported by Mg2+ or Mn2+, was independent of GTP, and was additive to the stimulatory G protein-dependent AC response (via beta-adrenergic receptor stimulation). The activation of AC was dose dependent up to 100 mM bicarbonate with a 50% effective concentration of 2-3 mM. The HCO3- response was unaffected by 1 mM methazolamide, a carbonic anhydrase inhibitor, but HSO3- was a partially selective inhibitor compared with its effect on forskolin-stimulated AC activities. The presence of membrane-bound bicarbonate-sensitive AC in fluid-transporting tissues suggests an autoregulatory mechanism for intracellular HCO3- concentration acting via adenosine 3',5'-cyclic monophosphate in the control of membrane ion transporters.

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Nanoscale constituents in bulk materials can promote enhanced boundary-scattering in the transport of phonons as well as electrons, which is considered a key design factor for enhancing thermoelectric properties. Here, we demonstrate a method for synthesizing zinc oxide bulk materials from nanoparticles without significant grain growth by means of pressure-induced deformation at 200°C. This allows us to comprehensively analyze the grain size dependence of thermoelectric properties in the nanoscale range above 30 nm, the size of a nanoparticle. Grain size was found to largely influence thermal conductivity as well as electrical conductivity. The observed thermal conductivity agreed with the Callaway model, indicating that enhanced phonon boundary-scattering was responsible for the variation. On the contrary, Seebeck coefficient was mostly governed by effective mass and carrier concentration, and was independent of the grain size. The dimensionless figure of merit systematically increased with grain size, which challenged the effect of nanograin on this system.

Embryogenesis-stimulating activity (ESA) was found in serum-free conditioned media (CM) of bovine cumulus/granulosa cells (BGC) and bovine oviductal epithelial cells (BOEC). The CM of BGC (BGC-CM) contained two molecular species of ESA, one with a low molecular weight (M(r) 30,000) and another with a high molecular weight (M(r) 80,000); but only the activity with low molecular weight was detected in CM of BOEC by gel-permeation chromatography. The smaller ESA (embryogenin-1) in BGC-CM was purified to homogeneity, as a common activity in both CM by a combination of gel-permeation chromatography, ion-exchange chromatography, and reverse-phase HPLC. Embryogenin-1 has a molecular weight of 31,100 (reduced) and has been identified as a bovine tissue inhibitor of metalloproteinase-1 by NH2-terminal amino acid sequence analysis. Western blot analysis, anti-proteinase activities against metalloproteinases, and the nucleotide sequence of cDNA isolated from a lambda gt11 cDNA library of the bovine ovary by a polyclonal antibody against embryogenin-1. These data suggest that the tissue inhibitor of metalloproteinase-1 produced by BGC and BOEC is a major ESA for in vitro development of bovine embryos.

Bulk ZnO with a grain size of 20 nm was successfully obtained by pulsed electric current sintering. The crystalline size was almost identical to that of the raw particles, because the sintering temperature was as low as 200°C. A pressure of 500 MPa effectively enhanced densification, leading to a relative density of >90% at 200°C. The small grain size led to a low thermal conductivity of 3 W/m K at room temperature, due to enhanced boundary scattering. The Seebeck coefficient was higher than that of micrograined ZnO with similar Ga doping (0.3 at.% Ga). However, the resistivity was increased by more than 1000 times. The temperature dependence of conductivity showed thermally activated conduction behavior, while that of micrograined ZnO exhibited metallic-like behavior. The thermoelectric properties suggest that a carrier trap in the nanograined ZnO hinders carrier transport. Surface modification of the ZnO nanoparticles by heat treatment in H 2 resulted in observable photoluminescence which was quenched in the starting nanoparticles, and led to a decrease in the resistivity of the sintered bulk, which indicates that control of surface defects on the nanoparticles is crucial for enhancement of the thermoelectric properties of nanograined ZnO.

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