Abstract: A preparation method for a silica aerogel, comprising the following steps: A) raw material containing a solid silicon source and an alkaline solution is used to produce an aerogel precursor after mixing; and B) the aerogel precursor is dried to obtain a silica aerogel. An improved silica aerogel preparation method, comprising the following steps: A) a cation exchange resin and a silicate solution are used as raw materials and mixed; B) the mixed material is allowed to stand to obtain an aerogel precursor; and C) the aerogel precursor is dried to obtain a silica aerogel.

Abstract: The TaNAC2 gene can promote uptake and utilization of nitrogen in a plant. A method for improving the uptake, transport and/or assimilation of nitrogen element in the plant includes: introducing a gene encoding a protein represented by SEQ ID NO:4 into a primary plant to obtain a transgenic plant. Compared to the primary plant, the uptake, transport and/or assimilation of the nitrogen element in the transgenic plant are improved. The method provides advantages in that: the TaNAC2 gene, as a nitrate nitrogen responsive regulatory factor, which can regulate the expression of a series of genes in nitrogen element uptake pathways of wheat, greatly promotes the study of the metabolism and utilization of the nitrogen element in a plant; and it is possible to improve the assimilation efficiency of nitrogen element by increasing the expression of TaNAC2, thereby reducing fertilizer application and increasing yield.

Abstract: The present invention provides porous structures that each comprise chitosan, alginate and divalent metal cations, wherein: (a) the chitosan is ionically linked to the alginate; and (b) the structure is porous and has a compressive yield strength of at least 0.35 MPa. The present invention also provides methods for making the porous structures, and methods for using the porous structures as substrates to grow living cells.

Abstract: A method for expanding a population of stem cells using a porous scaffold, a porous scaffold populated with renewed stem cells, methods of administering stem cells using the porous scaffold and cells collected from the porous scaffold, and methods for tissue engineering and treating a condition treatable by administration of stem cells using the porous scaffold and cells collected from the porous scaffold.

Abstract: The present invention provides porous structures that each comprise chitosan, alginate and divalent metal cations, wherein: (a) the chitosan is ionically linked to the alginate; and (b) the structure is porous and has a compressive yield strength of at least 0.35 MPa. The present invention also provides methods for making the porous structures, and methods for using the porous structures as substrates to grow living cells.

Abstract: The present invention provides porous structures that each comprise chitosan, alginate and divalent metal cations, wherein: (a) the chitosan is ionically linked to the alginate; and (b) the structure is porous and has a compressive yield strength of at least 0.35 MPa. The present invention also provides methods for making the porous structures, and methods for using the porous structures as substrates to grow living cells.

Abstract: The present invention provides porous structures that each comprise chitosan, alginate and divalent metal cations, wherein: (a) the chitosan is ionically linked to the alginate; and (b) the structure is porous and has a compressive yield strength of at least 0.35 MPa. The present invention also provides methods for making the porous structures, and methods for using the porous structures as substrates to grow living cells.