Gamma-tocotrienol stimulates the proliferation, differentiation, and mineralization in osteoblastic MC3T3-E1 cells

Gamma-tocotrienol, a major component of tocotrienol-rich fraction of palm oil, has been suggested to exhibit bone protective effects in vivo. However, the effects of γ-tocotrienol on osteoblast cells are still unclear. In this study, the effects of γ-tocotrienol on the proliferation, differentiation, and mineralization in osteoblastic MC3T3-E1 cells were investigated. Our results showed that γ-tocotrienol (2–8 μmol/L) significantly improved the cell proliferation (), but it did not affect cell cycle progression. γ-Tocotrienol significantly increased alkaline phosphatase (ALP) activity (), secretion levels of osteocalcin (OC) and osteonectin (ON), and mRNA levels of collagen type I (Col I) of MC3T3-E1 cells. Meanwhile, we found that γ-tocotrienol is promoted in differentiation MC3T3-E1 cells by upregulation of the expression of Runx2 protein. Moreover, the number of bone nodules increased over 2.5-fold in cells treated with γ-tocotrienol (2–8 μmol/L) for 24 d compared to control group. These results indicated that γ-tocotrienol at low dose levels, especially 4 μmol/L, could markedly enhance the osteoblastic function by increasing the proliferation, differentiation, and mineralization of osteoblastic MC3T3-E1 cells. Moreover, our data also indicated that Runx2 protein may be involved in these effects. Further studies are needed to determine the potential of γ-tocotrienol as an antiosteoporotic agent

Nanoscale Structural and Emission Properties within - Russian Doll- - Type InGaN/AlGaN Quantum Wells

Due to the increasing desire for nanoscale optoelectronic devices with green light emission capability and high efficiency, ternary III- N- based nanorods are extensively studied. Many efforts have been taken on the planar device configuration, which lead to unavoided defects and strains. With selective- area molecular- beam epitaxy, new - Russian Doll- - type InGaN/AlGaN quantum wells (QWs) have been developed, which could largely alleviate this issue. This work combines multiple nanoscale characterization methods and k- p theory calculations so that the crystalline structure, chemical compositions, strain effects, and light emission properties can be quantitatively correlated and understood. The 3D structure and atomic composition of these QWs are retrieved with transmission electron microscopy and atom probe tomography while their green light emission has been demonstrated with room- temperature cathodoluminescence experiments. k- p theory calculations, with the consideration of strain effects, are used to derive the light emission characteristics that are compared with the local measurements. Thus, the structural properties of the newly designed nanorods are quantitatively characterized and the relationship with their outstanding optical properties is described. This combined approach provides an innovative way for analyzing nano- optical- devices and new strategies for the structure design of light- emitting diodes.The chemical components of the nanorods, shape effects and strain effects given by this unique - Russian Doll- - type geometry of InGaN/AlGaN quantum wells are quantitatively related with the optical properties. This combined approach reported here provides an innovative way for analyzing nano- optical- devices and new strategies for the structure design of light- emitting diodes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162759/3/adom202000481_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162759/2/adom202000481.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162759/1/adom202000481-sup-0001-SuppMat.pd

Predicting Academic Performance: A Systematic Literature Review

The ability to predict student performance in a course or program creates opportunities to improve educational outcomes. With effective performance prediction approaches, instructors can allocate resources and instruction more accurately. Research in this area seeks to identify features that can be used to make predictions, to identify algorithms that can improve predictions, and to quantify aspects of student performance. Moreover, research in predicting student performance seeks to determine interrelated features and to identify the underlying reasons why certain features work better than others. This working group report presents a systematic literature review of work in the area of predicting student performance. Our analysis shows a clearly increasing amount of research in this area, as well as an increasing variety of techniques used. At the same time, the review uncovered a number of issues with research quality that drives a need for the community to provide more detailed reporting of methods and results and to increase efforts to validate and replicate work.Peer reviewe

Al-rich Region of Al-Cu-Mn

The Al–Cu–Mn alloy system was studied above 45 at.% Al between 550 and 910 °C by scanning electron microscopy, powder X-ray diffraction and differential thermal analysis. A wide ternary region of the so-called β-phase extending along ∼50 at.% Al was confirmed. It has a CsCl-type structure with a ≈ 0.292–0.298 nm. The total γ1/γ2-region extends from Al–Mn up to ∼17 at.% Cu and the high-temperature T-Al3Mn phase (Pnma, a ≈ 1.48, b ≈ 1.24, c ≈ 1.25 nm) extends up to ∼15 at.% Cu. The so-called R-phase (Bbmm, a ≈ 2.41, b ≈ 1.25, c ≈ 0.76 nm) was found to exist in a compositional region of Al74-80Cu5-12.5Mn12.5-18. The ternary phase earlier reported at Al57.9Cu26.3Mn15.8 was confirmed. It exists below 697 °C in a compositional region of Al55-58Cu29-37Mn7.5-14. The decagonal D3-phase was concluded to be stable in a compositional region of Al61.5-68.5Cu19-29.5Mn9-16. Below 631 °C an fcc phase (a = 0.5814 nm) was revealed around ∼ Al60Cu36.5Mn3.5. Partial isothermal sections at 550, 600, 650, 750, 850 and 910 °C were constructed

Atomic-scale investigation of spinel LiFe5O8 thin films on SrTiO3 (001) substrates

Microstructural properties of spinel LiFe5O8 (LFO) films grown on (001)-oriented SrTiO3 (STO) substrates have been investigated at the atomic-scale by advanced electron microscopy techniques. Two types of orientation relationship (OR) between the LFO films and the STO substrates have been determined, cube-on-cube and (111)[ 10]LFO//(111)[1 0]STO. Antiphase boundaries (APBs) and three types of twin boundaries (TBs) form within the LFO films, and the propagation of TBs and APBs results in their complex interactions. In most cases, interactions between TBs and APBs change the type of TBs and terminate the propagation of APBs since the APBs introduce a displacement vector of (a/4)〈110〉 into the TBs. In addition, the interactions between two coherent TBs are observed to generate the incoherent TB. The epitaxial strain of the LFO/STO (001) heterosystem can be released by the formation of TBs and APBs in the films and misfit dislocations at the interface. Considering that the magnetic coupling across the APBs and TBs can lead to novel physical properties, the appearance of APBs and TBs with a high density in the LFO films would affect the magnetic properties of the films

Correlation between growth kinetics and nanoscale resistive switching properties of SrTiO3 thin films

We deliberately fabricated SrTiO3 thin films deviating from ideal stoichiometry and from two-dimensional layer-by-layer growth mode, in order to study the impact of well pronounced defect arrangements on the nanoscale electrical properties. By combining transmission electron microscopy with conductive-tip atomic force microscopy we succeeded to elucidate the microstructure of thin films grown by pulsed laser deposition under kinetically limited growth conditions and to correlate it with the local electrical properties. SrTiO3 thin films, grown in a layer-by-layer growth mode, exhibit a defect structure and conductivity pattern close to single crystals, containing irregularly distributed, resistive switching spots. In contrast to this, Ti-rich films exhibit short-range-ordered, well-conducting resistive switching units. For Ti-rich films grown in a kinetically more restricted island growth mode, we succeeded to identify defective island boundaries with the location of tip-induced resistive switching. The observed nanoscale switching behavior is consistent with a voltage driven oxygen vacancy movement that induces a local redox-based metal-to-insulator transition. Switching occurs preferentially in defect-rich regions, that exhibit a high concentration of oxygen vacancies and might act as easy-diffusion-channels. (C) 2010 American Institute of Physics. [doi:10.1063/1.3520674