ABSTRACT
Preauricular sinus is a congenital malformation that is very commonly encountered among the general population and it has especially high prevalence among Asians when compared to other ethnic groups. It can often go unnoticed or easily overlooked by the patient or even by doctors because most of them are asymptomatic and is most of the time only a tiny pit that can be trivial in terms of aesthetics. We report a very rare and unique case that has no precedence what so ever; hence no reported case in the literature: an ectopic preauricular sinus in a facial cleft and microsomia patient.
ABSTRACT
The problem of DNA-DNA interaction mediated by divalent counterions is studied using computer simulation. Although divalent counterions cannot condense free DNA molecules in solution, we show that if DNA configurational entropy is restricted, divalent counterions can cause DNA reentrant condensation similar to that caused by tri- or tetravalent counterions. DNA-DNA interaction is strongly repulsive at small or large counterion concentration and is negligible or slightly attractive for a concentration in between. Implications of our results to experiments of DNA ejection from bacteriophages are discussed. The quantitative result serves to understand electrostatic effects in other experiments involving DNA and divalent counterions.
