Using Modified-Intake Plasma-Enhanced Metal–Organic Chemical Vapor Deposition System to Grow Gallium Doped Zinc Oxide

We have used a modified-intake plasma-enhanced metal–organic chemical vapor deposition (MIPEMOCVD) system to fabricate gallium-doped zinc oxide (GZO) thin films with varied Ga content. The MIPEMOCVD system contains a modified intake system of a mixed tank and a spraying terminal to deliver the metal–organic (MO) precursors and a radio-frequency (RF) system parallel to the substrate normal, which can achieve a uniform distribution of organic precursors in the reaction chamber and reduce the bombardment damage. We examined the substitute and interstitial mechanisms of Ga atoms in zinc oxide (ZnO) matrix in MIPEMOCVD-grown GZO thin films through crystalline analyses and Hall measurements. The optimal Ga content of MIPEMOCVD-grown GZO thin film is 3.01 at%, which shows the highest conductivity and transmittance. Finally, the optimal MIPEMOCVD-grown GZO thin film was applied to n-ZnO/p-GaN LED as a window layer. As compared with the indium–tin–oxide (ITO) window layer, the n-ZnO/p-GaN LED with the MIPEMOCVD-grown GZO window layer of the rougher surface and higher transmittance at near UV range exhibits an enhanced light output power owing to the improved light extraction efficiency (LEE).

Soybean miR159-GmMYB33 Regulatory Network Involved in Gibberellin-Modulated Resistance to Heterodera glycines

Soybean cyst nematode (SCN, Heterodera glycines) is an obligate sedentary biotroph that poses major threats to soybean production globally. Recently, multiple miRNAome studies revealed that miRNAs participate in complicated soybean-SCN interactions by regulating their target genes. However, the functional roles of miRNA and target genes regulatory network are still poorly understood. In present study, we firstly investigated the expression patterns of miR159 and targeted GmMYB33 genes. The results showed miR159-3p downregulation during SCN infection; conversely, GmMYB33 genes upregulated. Furthermore, miR159 overexpressing and silencing soybean hairy roots exhibited strong resistance and susceptibility to H. glycines, respectively. In particular, miR159-GAMYB genes are reported to be involve in GA signaling and metabolism. Therefore, we then investigated the effects of GA application on the expression of miR159-GAMYB module and the development of H. glycines. We found that GA directly controls the miR159-GAMYB module, and exogenous GA application enhanced endogenous biologically active GA1 and GA3, the abundance of miR159, lowered the expression of GmMYB33 genes and delayed the development of H. glycines. Moreover, SCN infection also results in endogenous GA content decreased in soybean roots. In summary, the soybean miR159-GmMYB33 module was directly involved in the GA-modulated soybean resistance to H. glycines.

The miR528-D3 module regulates plant height in rice by modulating the gibberellin and abscisic acid metabolisms

Background Plant height, as one of the important agronomic traits of rice, is closely related to yield. In recent years, plant height-related genes have been characterized and identified, among which the D3 gene is one of the target genes of miR528, and regulates rice plant height and tillering mainly by affecting strigolactone (SL) signal transduction. However, it remains unknown whether the miR528 and D3 interaction functions in controlling plant height, and the underlying regulatory mechanism in rice. Results In this study, we found that the plant height, internode length, and cell length of internodes of d3 mutants and miR528-overexpressing (OE-miR528) lines were greatly shorter than WT, D3-overexpressing (OE-D3), and miR528 target mimicry (OE-MIM528) transgenic plants. Knockout of D3 gene (d3 mutants) or miR528-overexpressing (OE-miR528) triggers a substantial reduction of gibberellin (GA) content, but a significant increase of abscisic acid (ABA) accumulation than in WT. The d3 and OE-miR528 transgenic plants were much more sensitive to GA, but less sensitive to ABA than WT. Moreover, the expression level of GA biosynthesis-related key genes, including OsCPS1, OsCPS2, OsKO2 and OsKAO was remarkably higher in OE-D3 plants, while the NECD2 expression, a key gene involved in ABA biosynthesis, was significantly higher in d3 mutants than in WT and OE-D3 plants. Conclusion The results indicate that the miR528-D3 module negatively regulates plant height in rice by modulating the GA and ABA homeostasis, thereby further affecting the elongation of internodes, and resulting in lower plant height, which adds a new regulatory role to the D3-mediated plant height controlling in rice.

Gallium containing zinc borate bioactive glasses for bone graft applications

Zinc borate glasses with increasing gallium (Ga) content (0, 2.5, 5, 10, and 15 wt.% Ga) were synthesized with Ga replacing boron. X-ray diffraction (XRD) verified their amorphous state. Thermal analysis recorded a steady decline in both glass transition and crystallization temperatures with the addition of Ga. 11B magic angle spinning nuclear magnetic resonance spectroscopy showed incremental addition of Ga reduced the BO4/BO3 ratio. Next, Bioactivity and antibacterial properties were investigated. Ion release profiles showed that increased Ga content in the glass resulted in increased Ga ion release, but decreased the release of other ions. The formation of amorphous Ca-P on the surface of all the glasses after 24 hours of incubation in simulated body fluid was confirmed by scanning electron microscopy-energy dispersive spectroscopy, XRD and Fourier transform infrared spectroscopy analyses. Antibacterial evaluation of the glasses demonstrated that the addition of Ga increased the antibacterial potency of the glasses against P. aeruginosa (Gram-negative bacteria) while decreasing it against S. epidermidis (Gram-positive bacteria). Finally, the effect of glass composition on the viability and proliferation of preosteoblast and osteosarcoma cancer cells was investigated. Methyl Thiazolyl Tetrazolium (MTT) cell viability assays using glass degradation extracts revealed that the extracts from glasses with 0, 2.5 and 5 wt.% Ga did not lower the viability of preosteoblasts; however, extracts from glasses with 0 and 2.5 % Ga increased the viability of cancer cells. Therefore, glass with 5 wt.% Ga (G3) was selected for further analyses. The viability of preosteoblasts and osteosarcoma cells in contact with the G3 glass powders were also investigated using MTT assays. G3 powders could enhance the viability of preosteoblasts while decreasing the viability of osteosarcoma cells. According to Live/Dead assays, suppression of proliferation appeared to be the mechanism causing the reductions in the viability of osteosarcoma cells exposed to G3 powders. In conclusion, the performed in vitro characterizations confirmed the bioactivity and antibacterial activity of all glasses. However, G3 was selected as the most suitable composition for osteosarcoma-related graft operations as it could improve the viability of preosteoblasts without increasing the viability of cancer cells.

Gallium containing zinc borate bioactive glasses for bone graft applications

Zinc borate glasses with increasing gallium (Ga) content (0, 2.5, 5, 10, and 15 wt.% Ga) were synthesized with Ga replacing boron. X-ray diffraction (XRD) verified their amorphous state. Thermal analysis recorded a steady decline in both glass transition and crystallization temperatures with the addition of Ga. 11B magic angle spinning nuclear magnetic resonance spectroscopy showed incremental addition of Ga reduced the BO4/BO3 ratio. Next, Bioactivity and antibacterial properties were investigated. Ion release profiles showed that increased Ga content in the glass resulted in increased Ga ion release, but decreased the release of other ions. The formation of amorphous Ca-P on the surface of all the glasses after 24 hours of incubation in simulated body fluid was confirmed by scanning electron microscopy-energy dispersive spectroscopy, XRD and Fourier transform infrared spectroscopy analyses. Antibacterial evaluation of the glasses demonstrated that the addition of Ga increased the antibacterial potency of the glasses against P. aeruginosa (Gram-negative bacteria) while decreasing it against S. epidermidis (Gram-positive bacteria). Finally, the effect of glass composition on the viability and proliferation of preosteoblast and osteosarcoma cancer cells was investigated. Methyl Thiazolyl Tetrazolium (MTT) cell viability assays using glass degradation extracts revealed that the extracts from glasses with 0, 2.5 and 5 wt.% Ga did not lower the viability of preosteoblasts; however, extracts from glasses with 0 and 2.5 % Ga increased the viability of cancer cells. Therefore, glass with 5 wt.% Ga (G3) was selected for further analyses. The viability of preosteoblasts and osteosarcoma cells in contact with the G3 glass powders were also investigated using MTT assays. G3 powders could enhance the viability of preosteoblasts while decreasing the viability of osteosarcoma cells. According to Live/Dead assays, suppression of proliferation appeared to be the mechanism causing the reductions in the viability of osteosarcoma cells exposed to G3 powders. In conclusion, the performed in vitro characterizations confirmed the bioactivity and antibacterial activity of all glasses. However, G3 was selected as the most suitable composition for osteosarcoma-related graft operations as it could improve the viability of preosteoblasts without increasing the viability of cancer cells.