[ruslan_mart]

var str = 'data_loaded=1;param_access=1;priv=1;location.href= \'/blog/public/Vot_etot%20daZBlogKaravamnI%20STOriI\'';

var result = /'\/blog\/public\/([^']+)/i.exec(str);
result = result && result[1];

alert(result);