Throughout this paper, every groups are finite. The prime graph of a group $G$ is denoted by $Gamma(G)$. Also $G$ is called recognizable by prime graph if for every finite group $H$ with $Gamma(H) = Gamma(G)$, we conclude that $Gcong H$. Until now, it is proved that if $k$ is an odd number and $p$ is an odd prime number, then $PGL(2,p^k)$ is recognizable by prime graph. So if $k$ is even, the r...

BACKGROUND/PURPOSE The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. METHODS The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. ...

This interlaboratory study on determination of 25-hydroxyvitamin D (25-OH-D) in serum involved 15 laboratories in eight European countries. All could distinguish between normal (50 +/- 31 nmol/L, mean +/- SD) and grossly increased concentrations, but for eight laboratories the results for serum samples with low and normal 25-OH-D content overlapped. In general, values were well reproducible, bu...

‎let $g$ be a finite group and $pi_{e}(g)$ be the set of element‎ ‎orders of $g$‎. ‎let $k in pi_{e}(g)$ and $m_{k}$ be the number of‎ ‎elements of order $k$ in $g$‎. ‎set nse($g$):=${ m_{k} | k in‎ ‎pi_{e}(g)}$‎. ‎in this paper‎, ‎we prove that if $g$ is a group such‎ ‎that nse($g$)=nse($psl(2‎, ‎25)$)‎, ‎then $g cong psl(2‎, ‎25) $‎.

‎let $g$ be a finite group and $pi_{e}(g)$ be the set of element‎ ‎orders of $g$‎. ‎let $k in pi_{e}(g)$ and $m_{k}$ be the number of‎ ‎elements of order $k$ in $g$‎. ‎set nse($g$):=${ m_{k} | k in‎ ‎pi_{e}(g)}$‎. ‎in this paper‎, ‎we prove that if $g$ is a group such‎ ‎that nse($g$)=nse($psl(2‎, ‎25)$)‎, ‎then $g cong psl(2‎, ‎25) $‎.