delete columns inside a cell based on null elements

Hi! In this example:

union_cell = importdata("union_cell.mat");

I should know whether in the block included by rows 3:5 and columns 2:6, there are columns characterized by all null elements.

For example, columns 4:6 have the three rows with null elements. I need to delete those columns and get this:

Answer 1

[Matt J]

map = cellfun('isempty',union_cell)

tf=all(  map(3:5,:),1);

union_cell(:,tf)=[]