4-quinolin-8-yloxy Linked Triphenylamine Based Polyimides: Blue Light Emissive and Potential Hole-Transport Materials.

A series of fluorescent donor- acceptor (D-A) alternating copolyimides (P1, P2, P3 and P4) with 4-quinolin-8-yloxy linked triphenylamine main polymer chain have been synthesized by conventional polycondensation. All the synthesized co-polyimides were characterized by elemental, gel permeation chromatography and FTIR spectral analysis. These newly prepared PIs possess HOMO energy levels in range of - 4.74 to - 4.78 eV and have medium optical band gaps. The photoluminescence spectral analysis revealed blue to violet emission with appreciable efficiency with lower onset oxidation potentials suitable for the facile hole injection materials. All the photophysical and electrochemical properties were also explored in context of effect of the pendant 4- quinolin-8-yloxy, indicating suitable combination of donor (TPA) on one hand and imide and pendant as acceptor on both ends.Graphical Abstract.

Synthesis and Photophysical Study of New Green Fluorescent TPA Based Poly(azomethine)s.

A series of poly(azomethine)s (PAMs) were synthesized from N1-(4-aminophenyl)-N1-(4-phenoxyphenyl)benzene-1,4-diamine (DA) and various dialdehydes to investigate the influence of structure of polymer chain and triphenylamine-based phenoxy pendant group on the optoelectronic properties. The structural characterization of the resulting poly(azomethine)s was carried out by solubility test, gel permeation chromatography, viscosity measurement, fourier transform infrared (FTIR) spectral and CHN elemental analysis. The photophysical and electrochemical properties of the materials were scrutinized by UV-vis, photoluminescence, time correlation photon counting spectral analysis (TCSP) and cyclic voltammetry. The thermal stability of the poly(azomethine)s was assessed by differential scanning calorimetry and thermogravimetric analysis found to be stable upto 300 °C. These polymers exhibit moderate inherent viscosity range from 0.99 to 1.15 g dL- 1 and appreciable organosolubility. The presence of triphenylamine and azomethine (CH = N) linkage in our synthesized materials rendered them fluorescent, emitting green light upon excitation at 375 nm with quantum efficiencies of 3.9-8.5%. The pendant phenoxy group at para-position in new poly(azomethine)s has also lowered the onset oxidation potentials and elevated the HOMO levels. Additionally, the presence of conjugation increases the fluorescence time of the excited state in conjugated polymers which was found in the range 9.22-11.17 ns, sufficient to be use in future optoelectronic applications.

Basic neonatal resuscitation, knowledge assessment at primary health care centers of district Sheikhupura in Pakistan -- a cross-sectional study.

OBJECTIVE: To assess the knowledge of lady health visitors and midwives working at primary healthcare facilities about neonatal resuscitation. METHODS: The cross-sectional survey was conducted in District Sheikhupura of Pakistan's Punjab province from September to November 2013, and comprised lady health visitors and midwives at primary level healthcare facilities. Datas was gathered using a close-ended questionnaire. SPSS 16 was used for statistical analysis. RESULTS: Of the 103 health workers interviewed, 54(52.4%) were lady health visitors and 49(47.5%) were midwives. Overall, 71(69.90%) health workers had received training on neonatal resuscitation, while 32(30.10%) had no formal training. Basic neonatal resuscitative arrangements were available at all the 54(100%) basic health units and 7(100%) rural health centres. Basic neonatal care knowledge was found adequate but the knowledge of midwives on the subject was poor as only 24(49%) answered correctly. CONCLUSIONS: There is a need for regular in-service trainings of lady health visitors and midwives regarding Basic Neonatal Resuscitation.