Do the sons and daughters of the deceased brother inherit from their uncle, who has no male children, but has one daughter, and a paternal uncle and paternal aunt who are still alive?

Your uncle's daughter and his siblings inherit. The daughter receives half, as Allah Almighty says: "And if there is only one, she will have half." The remainder goes to the siblings, with the male receiving the share of two females, if they are full siblings or paternal siblings, as Allah Almighty says: "And if they be brethren, men and women, then for the male will be the share of two females." Maternal siblings do not inherit if a daughter is present. In this case, the remainder is between you and your brother, based on the hadith: "Give the prescribed shares to those entitled to them, and whatever remains is for the nearest male relative." The maternal brother does not inherit in the presence of the daughter, and the full brother takes the remainder. The paternal brother does not inherit with the full brother, and the nephew does not inherit with the full brother or the paternal brother. The niece does not inherit at all.