Virginia Commonwealth University in Richmond, Va., has signed a contract with extremely restrictive terms to do research for Philip Morris USA, the nation’s largest tobacco company and a unit of Altria Group. The contract bars professors from publishing the results of their studies, or even talking about them, without Philip Morris’s permission. It raises questions about how far universities will go in search of scarce research dollars to enhance their standing. A university official acknowledges that many of the contract provisions violated the university’s guidelines for industry-sponsored research