Although NaHS and Na2S presented promising biological results both in vitro and in vivo, the likelihood of their use in clinical applications is small due to reasons such as release kinetics, smell, lack of ability to target, and difficulty in controlling its concentration because of hydrogen sulfide׳s volatility.
Despite their importance, little is known about the genomic diversity harbored in phages, as methods to capture complete phage genomes have been hampered by the lack of knowledge about the target genomes, and difficulties in generating sufficient quantities of genomic DNA for sequencing.
There are a number of problems associated with antibody-based photodynamic therapies, including difficulty to achieve specific antibodies that also display high affinity, inconsistent expression of target antigens, and difficulty to internalize antibodies by the same cells [ 70].
She was anchored bow and stern, broadside to her target, and had difficulties dealing with the tidal currents.
A report produced by Somerset council last year highlighted problems including some missed targets, IT teething problems and difficulties in establishing a level of loyalty from transferred staff, although its customer contact centre and management spending controls were praised.
This lack of qualified personnel, combined with intensifying attacks against both coalition and administration targets and the subsequent difficulty recruiting workers, deeply impacted the ability of the still-forming government to function.
While optogenetics is continuing to enable novel studies that were previously impossible, a number of fundamental limitations exist, including lack of deep tissue penetration using conventional visible light sources, the need for invasive surgeries to deliver light, and difficulties in targeting deeper brain regions [43].
Many inhalable drug formulations suffer from low respirable fractions, rapid clearance by alveolar macrophages, target non-specificity, and difficulty in combining aerodynamic properties with efficient cellular uptake.
Sensory nerve disorders are difficult to cure completely considering poor nerve regeneration capacity and difficulties in accurately targeting neural tissues.
The rout was so complete, however, that fighter-bombers were having difficulty finding targets and distinguishing between Taliban fighters fleeing in aid workers' vehicles and noncombatants trying to escape the mayhem, Pentagon officials said.
