NEW YORK — Sears, a back-to-school shopping destination for generations of kids, has said that after years of losing money that there is "substantial doubt" it will be able to keep its doors open. But it also insisted that its actions to turn around its business should help reduce that risk.It was still a dramatic acknowledgment from the chain that owns Sears and Kmart stores, which has long held fast to its stance that a turnaround is possible, even as many of its shoppers [...]