Sentence examples for has proven difficult with from inspiring English sources

Chips used in computers are currently made at the 14nm scale, but going smaller has proven difficult, with 7nm the latest breakthrough.

However, repeating initial successful TGC trials that reduced mortality and other outcomes has proven difficult with more failures than successes.

Maintaining native perennial bunchgrasses is key to controlling annual grass expansion, but postfire restoration of these species has proven difficult with traditional fall drill-seeding.

However, inducing neutralizing antibodies specific to the broad range of HIV subspecies has proven difficult with current candidate vaccines.

By contrast, detailed characterization of the common breakpoint regions as well as the identification of the specific genes targeted by such abnormalities has proven difficult with these approaches.

Treating severe childhood obesity has proven difficult with inconsistent treatment results.

But that fight has proved difficult, with suspicions of bribes, money laundering, organized crime, fraud and now organ trafficking, ensnaring high-level government officials.

Appointing staff has proved difficult, with overnight closures at its accident and emergency unit partly caused by a lack of doctors and nurses in key areas.

Finding the genetic factors in autism has proved difficult, with one study implicating hundreds of genetic mutations, many of which arise spontaneously.

The cancer has proven difficult to control with conventional therapeutic and surgical approaches, and the prognosis is poor with an overall 5-year survival rate of 10 14% in the USA (Jemal et al, 2004).

This question has proven difficult to answer, with some researchers proposing independent "pointers" for tracking separate targets [12], while others proposing a single spotlight or multiple interdependent spotlights for all targets [13].