MOSCOW, April 27. /TASS/. The one-time cash injection into the economy will not generate a positive effect in the midterm, press secretary of the Russian president, Dmitry Peskov said on Monday in an interview with the Rossiya-24 TV Channel.”A certain one-time effect can be positive but such methods of work in the midterm will lead to the fact that we will eventually be left without the positive effect at all,” Peskov said.There is a need “to be extremely careful” in the use of reserves, he noted. “The safety margin is available but it should be spent with care, as President [Vladimir Putin] reiterated,” Peskov added.