Select Medical to Go Private, Shares Soar  CHICAGO (Reuters) - Select Medical Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=SEM.N target=/stocks/quickinfo/fullquote"&gt;SEM.N&lt;/A&gt;, which  operates acute care hospitals, said on Monday it struck a deal  to be taken private in a \$2.3 billion buyout led by a private  equity group, sending shares soaring 23 percent.