Visitor Visa - B2

I will apply usa visit visa next week, previously I have rejected in 2014,as VO said that I do not have strong ties in Pakistan, I live alone in karachi Pakistan, My mother and father has died, my brother lives in UK, I visited him in May 2016 for one month,my age is 39 ,my own bank statment is around 11lac pak rupess,So please guide me how to handle this situation, my sister is professor in university in USA and she is us national.Is there any significant chance to get the visa this time?.

Thanks

Imran