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The aim of this study was to investigate the role of microRNA-222 (miR-222) in osteosarcoma (OS), and to further explore the potential molecular mechanism.We measured the level of miR-222 in OS tissues and cell lines using quantitative Real-time polymerase chain reaction. Synthesized miR-222 mimics or inhibitors were obtained to up-regulate or down-regulate the expression of miR-222 in U2OS or Saos2 cells. Cell counting kit-8 (CCK8) and colony formation assay were employed to detect the ability of cell proliferation, and transwell assay was used to confirm the ability of cell invasion. Furthermore, luciferase assay and Western blot were applied to verify the target of miR-222 in OS.The level of miR-222 in OS tumor tissue samples was significantly lower than that in normal group. Over-expression of miR-222 decreased cell proliferation and invasion in U2OS cells while knockdown of miR-222 promoted cell growth and metastasis in Saos2 cells. Furthermore, YWHAG was found to be a candidate target of miR-222 using several databases. Elevated level of miR-222 inhibited YWHAG expression while reduced miR-222 promoted YWHAG expression. Also, up-regulation of YWHAG restored the inhibiting effect of miR-222 mimics.We identified for the first time that the expression level of miR-222 was reduced in OS tissues as well as in OS cell lines. miR-222 could inhibit cell proliferation and invasion via down-regulating YWHAG. These data could provide a potential target for the biological treatment of OS.

In order to control the cavitation generated by oily medium, the advantage of mechanical production brought by cavitation is better utilized, and the mechanical damage of parts caused by cavitation is avoided, it is concluded that the cavitation pressure of lubricating oil of oily medium. The pressure field, streamline diagram and cavitation phase diagram were obtained by Ansys Fluent numerical calculation of the oily medium in the flow field of expanding region, the analysis of the mechanism of cavitation. The test bench of cavitation jet is designed, and verified with the simulation results, the specific value of critical pressure of lubricating oil cavitation under different apertures is obtained, and collected cavitation images. The pressure field decreases from the pressure inlet to the outlet, the cavitation occurs in the vicinity of the low pressure zone and the high pressure zone. When the diameter of the jet hole becomes larger, the cavitation occurs more difficult. The lower the viscosity of the lubricating oil, the higher the temperature, the occurrence of cavitation requires higher pressure to stimulate.

The effect of pre-existing shear bands induced by cold-rolling on the crystallization behavior was investigated in the Cu46Zr46Al8 bulk metallic glass. It was found that with increasing degree of pre-deformation, more shear bands are created resulting in the decrease of the crystallization activation energy for the alloy. Our experimental results demonstrate that pre-existing shear bands can promote the nucleation of crystals, which is discussed in terms of nucleation thermodynamics and kinetics aspects.

Ultrafine amorphous Fe–B alloy nanoparticles are self-assembled within anodic aluminum oxide templates by combining a preparation process of Fe–B nanoparticles with a template method. Scanning electron microscopy, inductively coupled plasma-atomic emission spectrometry, X-ray diffraction spectrometry, Mossbauer spectrometry, and vibrating sample magnetometry are employed to study the morphology, chemical composition, structure, and magnetic properties of the nanoparticle assemblies, respectively. The results show that the alloy particles are amorphous with a boron content of 24 at. % and can be in shape of sphere and rod by controlling the duration of preparation. There is a narrow distribution of the sizes of spherical nanoparticles with an average diameter below 35 nm in relatively short preparation time, while rods are found in longer time. The measurements of magnetic properties indicate that the nanoparticles are mostly in superparamagnetic state and the self-assembly of the nanoparticles has a weak magnetic anisotropy with an easy direction perpendicular to the template plane.

Thin high-k dielectric HfO2 films are deposited on Si(100) substrate by molecular beam epitaxy using Hf and atomic oxygen source. The composition of the film is determined to be stoichiometric HfO2. The very flat surface of the deposited film with a root mean square roughness less than 0.16nm without any visible pin holes down to the nanometer size can be reached. The film maintains good thermal stability after annealing at 900°C for 15min in N2 ambient. The refractive index of the film is 1.89 with a negligible extinction coefficient in the visible wavelength region and the dielectric constant is around 19. A low leakage current of 1.61×10−3A∕cm2 at −2V bias is achieved for a film with the equivalent oxide thickness of 2.4nm after annealing.

Plasma spraying with axial powder injection inside the anode nozzle is a method considered to markedly enhance deposition efficiency and reduce plasma power compared to the most general method of injecting powder at the nozzle exit. However, powder injecting inside the nozzle will also likely cause problems from powder deposition on the nozzle wall and clogging of the particle feed channels. In this study, spherical stainless steel 316 and angular alumina powders with a mean size of 20-40 μm are used to deposit coatings via axial powder injection. The effect of powder feed rate, gas flow rate, and plasma power on deposition efficiency and particle clogging are investigated. The results show that particle clogging can be avoided by reducing powder feed rate and increasing the velocity of the plasma jet.

We report here the alteration(s) in the expression of the DNA repair gene, DNA polymerase beta, in kidney tumors induced by stilbene estrogen (diethylstilbestrol, DES). RT-PCR, slot blotting, and Northern blotting experiments revealed that expression of DNA polymerase beta (DNA pol beta) was several fold lower in stilbene-estrogen-induced kidney tumors than in age-matched controls. Several mutations were identified in DNA pol beta mRNA from DES-induced kidney tumors, but not in age-matched control kidney. The mutations in DNA pol beta mainly occurred in the catalytic domain of pol beta, and not in the DNA binding domain. All the mutations produced a stop codon at nucleotide 199 indicating that a protein of aberrant size may be synthesized. These data suggest that mutation of DNA pol beta coupled with attenuation in expression might compromise the DNA repair system. This in turn may allow a greater error rate during DNA repair and the accumulation of lesions in the genome.

This study was designed to optimize conditions for transfection of a mammary gland specific transgene into bovine fetal fibroblasts. Transfection of Sulfolobus solfataricus β-glycosidase gene (lacS) was mediated by liposome. Neomycin resistance (Neor) and enhanced green fluorescent protein (EGFP) gene were used as genetic markers to screen transgenic somatic cells. A 0.92-kb fragment of bovine β-lactoglobulin gene sequence was obtained from bovine genome by PCR amplification and was inserted into the T site of pMD19-Simple T plasmid. 1.49 kb of lacS gene coding sequence was cloned from Sulfolobus solfataricus genome by PCR amplification and inserted into the pUC19 plasmid. The coding sequence of Neor was derived by PCR amplification from pIRES2-EGFP plasmid and inserted into the BamHI/NheI site of pIRES2-EGFP plasmid. The resultant vector (pNIE) contained a Neor and an EGFP gene, which were linked by an internal ribosome entry site sequence downstream of the cytomegalovirus (CMV) promoter. Finally, the vector pNIE was assembled into the pUC19 plasmid, thus creating a pBLI vector, which contained the Neor and EGFP gene regulated by CMV promoter for expression in a non-tissue specific mode and the lacS gene regulated by bovine β-lactoglobulin promoter for specific expression in mammary gland. Bovine fetal fibroblasts (bFF) were isolated from the ear skin of female fetuses at the age of 2 to 3 months. The cells proliferated well and grew normally in culture, with typical fibroblast morphology and growth curve. The effects of different concentrations of transfection and pBLI were compared on the efficiency of transfection. The passage 4 bFF cells at 70 to 80% confluency were transfected in a 24-well culture plate. 2 × 105 cells were cultured in DMEM with 0.5, 0.75, 1.0, 1.5, 2.0, and 2.5 μg of pBLI using transfection (1, 2, 3, 4, 5, and 6 μL) for 48 h, respectively. The transfected cells were cultured for 48 h before adding G418 at concentrations of 200, 300, 400, 500, 600, 700, 800, and 900 μg mL–1 for 14 d, respectively. Positive cell colonies were selected and purified through both the expression of Neor and EGFP gene under a fluorescence microscopy. The selected colonies were propagated in DMEM containing 300 μg mL–1 G418. The results showed that bright green fluorescence could be detected at 48 h after transfection. 1.0 μg of pBLI plasmid and 3 μL of transfection yielded the desirable efficiency of transfection. More transgenic bFF colonies were selected by G418 at the concentration of 800 μg mL–1. In conclusion, a specifically expressed vector in mammary gland for lacS gene was successfully constructed, transfection parameters were developed, and efficient screening measures were established for detecting transgenic somatic cells.

The effects of several growth factors on the proliferation of fibroblastic colony-forming units (CFU-F) were studied. In the present study CFU-F colonies were found to consist of fibroblasts, macrophages, and endothelial cells. Growth factors, including interleukin 3 (IL-3), interleukin 1 alpha (IL-1 alpha), epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), macrophage colony-stimulating factor (M-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and buffalo rat liver cell-conditioned medium (BRL-CM) were tested for stimulation of the proliferation of CFU-F in a standard culture in both 2% and 15% serum. Overall, the colony numbers produced in 15% serum were much higher than in 2% serum with or without growth factors. However, the influence of several growth factors on CFU-F cultured in 2% serum was relatively greater than in 15% serum when compared to controls. The stimulation of CFU-F by FGF only occurred in culture with 15% serum, and the stimulation by PDGF only occurred with 2% serum. Overall, the strongest stimulations were produced by PDGF, IL-3, and BRL-CM. Combining the other growth factors with IL-3, PDGF, or IL-1 alpha enhanced their effects only modestly. The stimulation by growth factors included increases of the cell numbers between and within colonies as well as an increase in the number of colonies. The study produced results that suggest a complex interaction mediated by growth factors between fibroblasts and other stromal cells within the CFU-F colonies and within the bone marrow itself.

Purified normal murine bone marrow-derived fibroblasts were shown to produce a factor that stimulates the in vitro growth of fibroblastic colony-forming unit (CFU-F) colonies. Conditioned medium from the purified fibroblasts (F-CM) also stimulated pure marrow fibroblasts themselves. Analysis of the F-CM detected the presence of macrophage colony-stimulating factor (M-CSF), and low levels of interleukin 1 (IL-1) and interleukin 6 (IL-6), but no detectable levels of interleukin 3 (IL-3), interleukin 5 (IL-5), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte colony-stimulating factor (G-CSF). Macrophages and endothelial cells, freed from other bone marrow components, required the F-CM if no other growth factors were added. We conclude that F-CM contains an autocrine factor, which the evidence suggests is IL-1, for bone marrow fibroblasts, and a paracrine factor (CSF-1) for macrophages and/or endothelial cells.