Electrical, optical and theoretical characterization of doped and undoped calamitic liquid crystal: (s)-5-octyloxy-2-[[[4-(2-methyl butoxy) phenyl] imino] methyl] phenol

The electrical conductivities of undoped and doped calamitic liquid crystalline compound, (S)-5-octyloxy-2-[[[4-(2-methylbutoxy) phenyl] imino] methyl] phenol (OMPIMP) with tetrabutylammonium tetrafluoroborate as dopant were determined as a function of temperature. Optical studies of undoped and doped OMPIMP thin films were also carried out using spectrophotometer. Optical band gaps of doped and undoped OMPIMP thin films were determined through absorption spectra using Tauc plot. The frontier orbital energies; E-HOMO, E-LUMO and the band gap energies were calculated from the DFT calculations which were carried out by the hybrid B3LYP functional

Electrical and thermodynamical characterization of thermotropic liquid crystal

The thermodynamic interactions, sorption properties and electrical conductivity measurements of thermotropic liquid crystalline compound, (S)-5-dodecyloxy-2-[[[4-(2-methylbutoxy) phenyl]imino]methyl]phenol (DMPIMP) are experimentally investigated in this work. The retention diagrams of trace amount of solvents such as benzene, propylbenzene, chlorobenzene were passed through the gas chromatography column loaded with DMP IMP coated on Chromosorb W. The retention diagrams of the solvents on DMPIMP were plotted by means of specific retention volumes, V-g(0) at the temperatures in K between 363 and 383 by inverse gas chromatography. Flory-Huggins liquid crystal-solvent interaction parameter, chi(infinity)(12), equation of state liquid crystal-solvent interaction parameter, chi(12)*, the weight fraction activity coefficient, Omega(infinity)(1) and effective exchange energy parameter, X-eff and molar enthalpies related to the DMPIMP-solvent systems were obtained. The DMPIMP films were also characterized by means of its electrical properties depending on doping effect for the films having two different dopant concentrations such as 25 and 50 percent of tetrabutylammonium tetrafluoroborate

Incidence, risk factors and severity of retinopathy of prematurity in Turkey (TR-ROP study): a prospective, multicentre study in 69 neonatal intensive care units

Background To evaluate the prevalence, risk factors and treatment of retinopathy of prematurity (ROP) in Turkey and to establish screening criteria for this condition. Methods A prospective cohort study (TR-ROP) was performed between 1 April 2016 and 30 April 2017 in 69 neonatal intensive care units (NICUs). Infants with a birth weight (BW)=1500 g or gestational age (GA) 1500 g or GA> 32 weeks with an unstable clinical course were included in the study. Predictors for the development of ROP were determined by logistic regression analyses. Results The TR-ROP study included 6115 infants: 4964 (81%) with a GA 32 weeks. Overall, 27% had any stage of ROP and 6.7% had severe ROP. A lower BW, smaller GA, total days on oxygen, late-onset sepsis, frequency of red blood cell transfusions and relative weight gain were identified as independent risk factors for severe ROP in infants with a BW=1500 g. Of all infants, 414 needed treatment and 395 (95.4%) of the treated infants had a BW <= 1500 g. Sixty-six (16%) of the treated infants did not fulfil the Early Treatment for Retinopathy of Prematurity requirements for treatment. Conclusions Screening of infants with a GA <= 34 weeks or a BW<1700 g appears to be appropriate in Turkey. Monitoring standards of neonatal care and conducting quality improvement projects across the country are recommended to improve neonatal outcomes in Turkish NICUs