Differentiation potential of SOX2-positive stem cells in the bovine pituitary gland.

The pituitary gland is the master endocrine gland, harboring stem cells with various genetic characteristics; however, data from non-rodent and non-human sources are scarce. In this study, we isolated putative stem cells from the bovine pituitary gland and investigated their potential for differentiation into hormone-producing cells. Immunohistochemical analysis revealed that in calves and heifers, stem cell marker sex-determining region Y-box 2 (SOX2)-positive cells were widely present in the pituitary gland and partially co-localized with anterior pituitary hormones. Next, a single-cell suspension of primary anterior lobe cells from bovines aged 0 and 12 months was subjected to two-dimensional culture. Consequently, some cells proliferated in the culture dishes. The expression levels of Sox2 and several other stem cell markers were higher in these cells after culture. In addition, almost all proliferating cells were positive for SOX2, whereas all were negative for hormones. In three-dimensional cultures, SOX2-positive cells presented a spheroid-like morphology and differentiated into endocrine cells. These results provide evidence that SOX2-positive cells are pituitary stem cells with the potential to differentiate into hormone-producing cells, regardless of age. Our data lay a theoretical foundation for further studies on controlling fundamental processes, such as body growth, reproduction, and lactation.

Improvement of Pharmaceutical Properties of Isoprenoid Compounds through the Formation of Cyclodextrin Pseudorotaxane-Like Supramolecules.

The purpose of this study was to design cyclodextrin (CyD)-based pseudorotaxane-like supramolecular complexes with various isoprenoid compounds, such as reduced coenzyme Q10 (R-CoQ10), squalene, tocotrienol, and teprenone, and to evaluate their pharmaceutical properties. Squalene, tocotrienol, and teprenone formed precipitates with ß-CyD and γ-CyD in aqueous solution, whereas R-CoQ10 formed precipitates with γ-CyD aqueous solution. The results of powder X-ray diffraction and (1)H-NMR analyses indicated that these precipitates are derived from pseudorotaxane-like supramolecular complexes. The photostability of teprenone was markedly improved by complexation with CyDs, especially in the γ-CyD system. In addition, the dispersion rates of teprenone in the γ-CyD system were higher than those in the ß-CyD system, compared with the corresponding physical mixtures. In conclusion, pharmaceutical properties such as photostability and dispersion rates of isoprenoid compounds were improved by the formation of pseudorotaxane-like supramolecular complexes with ß-CyD and/or γ-CyD.

Synthesis of Hollow Carbon Nano-Onions Using the Pulsed Plasma in Liquid.

We synthesized carbon nano-onions (CNOs) using a low-voltage spark discharge in a liquid and studied the effects of liquid type and pulse duration. By the pulsed electric discharge between two graphite rods of 120 mm length and 6 mm diameter submerged into a 200 ml toluene or ethanol, hollow CNOs with diameters ranging from 10 to 30 nm were produced. CNOs produced using toluene grew more carbon shells than does the sample produced using ethanol. The sample that was synthesized using pulsed plasma with pulse duration of 5 µs showed more carbon shells (10-30) than the sample prepared by 12 µs (2 to 10). High performance liquid chromatography (HPLC) and high resolution transmission electron microscopy analyses confirmed that the sample produced at 12 µs pulsed plasma contains fullerene C60, while the sample prepared at 5 µs does not.

Relationship between the somatic cell count in milk and reproductive function in peripartum dairy cows.

The aim of the present study was to examine the effect of the somatic cell count (SCC) in milk on reproductive performance, such as pregnancy status in the prepartum period and ovarian function in the postpartum period, in dairy cows. Blood samples were collected every week from one month prepartum to parturition in order to measure the concentrations of 13,14-dihydro-15-keto-PGF2α (PGFM), estrone sulfate (E1S) and progesterone. Milk samples were collected three times per week in both the prepartum (for one month before the dry period) and postpartum periods (for 3 months immediately after parturition) to measure the SCC. Progesterone was also determined in the whole milk of postpartum cows to define the day of the first ovulation. In the prepartum period, the maximum SCC negatively correlated with the pregnancy period (r = -0.77), but not the calf birth weight. Positive and negative correlations were observed between the average SCC and PGFM or progesterone concentrations in plasma, respectively (r = 0.84 or -0.92, respectively), at 39 weeks of pregnancy. In the postpartum period, a correlation was observed between the day of the first ovulation and both the average and maximum SCC (r = -0.74 and -0.75, respectively), whereas days open was not related to the SCC. These results suggest that a high SCC in the prepartum period may advance parturition by increasing PGF2α and decreasing progesterone and that the first ovulation in the postpartum period was affected by a high SCC.

Synthesis of novel CoCx@C nanoparticles.

CoC(x) nanoparticles encapsulated in carbon shells were synthesized using a pulsed plasma in liquid ethanol. This is the first time that monolithic cubic phase cobalt carbide nanoparticles have been obtained. X-ray diffraction refinement of the nanoparticles showed that the lattice parameter of prepared cubic phase cobalt carbide is larger than that of CoC(x) (44-0962) and cubic phase Co (15-0806 and 01-1259). The x-ray absorption fine structure spectra near the Co K-edge of the synthesized sample indicated differences from commercial metallic cobalt and cobalt oxide samples. High resolution transmission electron microscopy revealed that a thin carbon coating covered the surface of the nanoparticles. These carbon layers might isolate core CoC(x) material from the outside environment, and allow functionalization by carboxyl groups for the further purpose of targeted drug delivery. The obtained CoC(x)@C particles, with a crystallite size of about 10 nm confirmed by the electron microscope, aggregate into 20-40 nm secondary particles in distilled water as shown by dynamic light scattering, and possess high saturation magnetization of about 120 emu g(-1). The sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene sulfonic acid hydrate assay and defragmentation of deoxyribonucleic acid on MCF-7 cells after incubation with particles indicate relatively low cytotoxicity of CoC(x)@C nanoparticles, compared with micro-sized and nano-sized metallic cobalt particles and commonly used iron oxides. For the small sized CoC(x)@C particles, the release of cobalt ions was checked by a chelation method with ethylenediaminetetraacetic acid solution to be at a very low level compared with other reference materials.

Wurtzite-type ZnS nanoparticles by pulsed electric discharge.

The synthesis of wurtzite-type ZnS nanoparticles by an electric discharge submerged in molten sulfur is reported. Using a pulsed plasma between two zinc electrodes of diameter 5 mm in molten sulfur, we have synthesized high-temperature phase (wurtzite-type) ZnS nanocrystals with an average size of about 20 nm. The refined lattice parameters of the synthesized wurtzite-type ZnS nanoparticles were found to be larger than those of the reported ZnS (JCPDS card no 36-1450). Synthesis of ZnMgS (solid solution of ZnS and MgS) was achieved by using ZnMg alloys as both cathode and anode electrodes. UV-visible absorption spectroscopy analysis showed that the absorption peak of the as-prepared ZnS sample (319 nm) displays a blue-shift compared to the bulk ZnS (335 nm). Photoluminescence spectra of the samples revealed peaks at 340, 397, 423, 455 and 471 nm, which were related to excitonic emission and stoichiometric defects.

Synthesis of blue amorphous TiO2 and Ti(n)O(2n-1) by the impulse plasma in liquid.

Synthesis of blue amorphous TiO2 and Ti(n)O(2n-1) by the impulse plasma in dielectric liquid is presented. The impulse plasma in liquid enables us to quench from plasma state, by which we can synthesize nanomaterials, metastable materials, etc. By the impulse plasma between titanium rods submerged into water, we have synthesized blue colored amorphous TiO2 nanoparticles suspended in water and black titanium monoxide at the bottom. Different types of titania oxides like Ti3O, TiO, Ti2O3, Ti4O7 were produced by the impulse plasma in different water temperatures (3, 30, 60, and 90 degrees C respectively). High Resolution Transmission Electron Microscopy analysis showed that the amorphous TiO2 contains anatase nanocrystals with less than 10 nm. UV-vis absorption spectra of the blue TiO2 nanoparticles showed higher absorbance of visible light than the commercially available pure anatase nanoparticles.

Identification of crack path of inter- and transgranular fractures in sintered silicon nitride by in situ TEM.

Inter- and/or transgranular crack paths in sintered silicon nitride (Si3N4) during fracture were investigated by in situ straining experiments in a transmission electron microscope at room temperature, using a high-precision micro-indenter. By this technique, cracks introduced in an in situ manner were observed to propagate in the grain interior and along grain boundaries. High-resolution electron microscopy (HREM) observation revealed that the crack propagation takes place at an interface between Si3N4 grains and an intergranular glassy film (IGF) in the case of intergranular fractures. According to the results by previous molecular dynamics simulations, a number of dangling bonds are present at the Si3N4/IGF interface, which should result in the observed fracture behavior at the interface. On the other hand, the crack path introduced during transgranular fracture of Si3N4 grains was found to be sharp and straight. The observed crack propagated towards [1120] inside the Si3N4 grain with the crack surface parallel to the (1100) plane. The HREM observations of crack walls revealed them to be atomically flat. The atomic termination of the crack walls was identified in combination with image simulations based on atomic models of the cleaved crack walls.

Multifunctional Alloys Obtained via a Dislocation-Free Plastic Deformation Mechanism.

We describe a group of alloys that exhibit "super" properties, such as ultralow elastic modulus, ultrahigh strength, super elasticity, and super plasticity, at room temperature and that show Elinvar and Invar behavior. These "super" properties are attributable to a dislocation-free plastic deformation mechanism. In cold-worked alloys, this mechanism forms elastic strain fields of hierarchical structure that range in size from the nanometer scale to several tens of micrometers. The resultant elastic strain energy leads to a number of enhanced material properties.