Silicon (Si) and phosphorus (P) are beneficial nutrient elements for plant growth. These elements are widely used in chemical fertilizers despite their abundance in the earth’s crust. Excessive use of chemical fertilizers is a threat to sustainable agriculture. Here, we screened different Si and P solubilizing bacterial strains from the diverse rice fields of Daegu, Korea. The strain with high Si and P solubilizing ability was selected and identified as Enterobacter ludwigii GAK2 through 16S rRNA gene sequence analysis. The isolate GAK2 produced organic acids (citric acid, acetic acid, and lactic acid), indole-3-acetic acid, and gibberellic acid (GA1, GA3) in Luria-Bertani media. In addition, GAK2 inoculation promoted seed germination in a gibberellin deficient rice mutant Waito-C and rice cultivar ‘Hwayoungbyeo’. Overall, the isolate GAK2 increased root length, shoot length, fresh biomass, and chlorophyll content of rice plants. These findings reveal that E. ludwigii GAK2 is a potential silicon and phosphate bio-fertilizer.

The current study aimed to isolate and identify japonica rice (Oryza sativa L. cv. Dongjin) root-associated rhizobacteria and to investigate their ability to solubilize silicate, produce indole acetic acid (IAA), promote plant growth, and encourage silicon (Si) uptake and deposit in plants. A single bacterial isolate was selected on the basis of its silica-solubilizing ability and IAA production. The 16S rRNA gene sequence of the isolate identified it as Burkholderia eburnea CS4-2. Burkholderia eburnea CS4-2 produced high amounts of IAA at pH 8. When combined with silica fertilization, soil inoculation with CS4-2 promoted all growth attributes over those of the water-treated (control) and insoluble silica-fertilized plants. Microscopic observations also demonstrated a significant difference in the Si deposits on the leaf epidermis of rice plants under different treatments, indicating that more Si was deposited in plants fertilized with both B. eburnea CS4-2 and insoluble silica than in either insoluble silica-fertilized or water-treated plants. Inductively coupled plasma spectrometry analysis confirmed the same trend of Si concentration in whole-plant biomass of the rice that received the same treatments, respectively. Therefore, we conclude that B. eburnea CS4-2 has the ability to produce IAA under high-pH conditions, solubilize silicate, and promote plant growth.

The crystallization behavior of nitrogen-doped amorphous Ge 2 Sb 2 Te 5 -(N) phase-change thin films was studied by utilizing differential scanning calorimetry, in situ ellipsometry and in situ transmission electron microscopy. The combined analysis of in situ ellipsometry isotherms of amorphous Ge 2 Sb 2 Te 5 -(N) films and the Johnson-Mehl-Avrami equation revealed that the crystallization process of amorphous Ge 2 Sb 2 Te 5 -(N) films changes depending on the nitrogen content. The crystallization behavior of Ge 2 Sb 2 Te 5 film revealed a two-step process that includes spherical-nucleation and disc-shaped grain growth. In contrast, nitrogen-doping into Ge 2 Sb 2 Te 5 thin films suppresses the second step and the crystallization of Ge 2 Sb 2 Te 5 -(N) becomes a onestep process that is the primary nucleation process. The number of nucleation sites during the crystallization of amorphous Ge 2 Sb 2 Te 5 -(N) films, increased markedly with the annealing temperature in the spherically shaped nuclei and eventually saturated. The effective crystallinity of Ge 2 Sb 2 Te 5 -(N) alloy films decreased with the increase in nitrogen content, mainly due to the grain-size refinement.

Given the high rate of aspiration in the infants who underwent open heart procedures, monitoring and prompt recognition of the signs and the risk factors of dysphagia may substantially improve infant care with oral feeding and reduce the duration of hospital stays.