Enzymatic ribosylation of fluorescent 8-azapurine derivatives, like 8-azaguanine and 2,6-diamino-8-azapurine, with purine-nucleoside phosphorylase (PNP) as a catalyst, leads to N9, N8, and N7-ribosides. The final proportion of the products may be modulated by point mutations in the enzyme active site. As an example, ribosylation of the latter substrate by wild-type calf PNP gives N7- and N8-rib...

The purpose of this study was to compare sprint test performance performed by football players of different ages and levels of competition. One hundred and forty six Portuguese players from different teams completed the test (seven maximal sprints interspersed with 25 s active recovery). A 6 (level of competition: 1(st) national division, 2(nd) national division, 1(st) regional division, sub 16...

heart produces and secretes a hormone called atrial natriuretic peptide. the aim of this research was to investigate the effect of eight weeks of resistance and sprint training on anp of non-athlete men. 36 non-athlete healthy men were randomly divided into three groups (12 subjects each group): resistance (mean age ± sd: 33.1±2.9 years), sprint (mean age ± sd:  32.1±2.5 years) and control (mea...

The current density-luminance-voltage characteristics of organic light-emitting devices ~OLEDs! with N ,N8-Bis~naphthalen-1-yl)-N ,N8-bis~phenyl! benzidine ~NPB! of various thicknesses as the hole transport layer have been investigated. It is found that for conventional structures of indium– tin–oxide/NPB/tris~8-hydroxyquinoline! aluminum (Alq3) ~60 nm!/LiF ~0.5 nm!/Al the optimal hole injectio...

This study examined the contribution of phosphocreatine (PCr) and aerobic metabolism during repeated bouts of sprint exercise. Eight male subjects performed two cycle ergometer sprints separated by 4 min of recovery during two separate main trials. Sprint 1 lasted 30 s during both main trials, whereas sprint 2 lasted either 10 or 30 s. Muscle biopsies were obtained at rest, immediately after th...

A 29‐year‐old male patient presented with decreased vision for 2 years following electrocution injury (electric cables with 25000 volts). No significant family or ocular history was elicited. He was diagnosed to have pigmentary retinopathy in both eyes clinically. Best corrected visual acuity (BCVA) was 6/12, N8 in the right eye and 6/18, N8 in the left eye. Anterior segment examination reveale...

The aims of the present study were to compare the effects of 1) training at 90 and 100% sprint velocity and 2) supervised versus unsupervised sprint training on soccer-specific physical performance in junior soccer players. Young, male soccer players (17 ± 1 yr, 71 ± 10 kg, 180 ± 6 cm) were randomly assigned to four different treatment conditions over a 7-week intervention period. A control gro...

The present study examined the growth hormone (GH) response to repeated bouts of maximal sprint cycling and the effect of cycling at different pedaling rates on postexercise serum GH concentrations. Ten male subjects completed two 30-s sprints, separated by 1 h of passive recovery on two occasions, against an applied resistance equal to 7.5% (fast trial) and 10% (slow trial) of their body mass,...