$re = '/Study Title: {[^}]*}/';
$str = '{\\af31507 \\ltrch\\fcs0 \\insrsid6361256 Study Title: {Test for 14431 process\\\'27s \\u8805 1000 Testing2 14432 \\u8805 8000}}{\\rtlch\\fcs1 \\af31507 \\ltrch\\fcs0 \\insrsid12283827';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php