RESUMO
A new carbazole-coupled tetrakis-(1 H-pyrrole-2-carbaldehyde) anion receptor 1 has been designed and synthesized. Anion binding studies in organic media using fluorescence and UV-vis spectroscopy revealed that receptor 1 is capable of sensing HP2O73- with high selectivity. Addition of HP2O73- to THF solution of 1 resulted in the emergence of a new broad band at longer wavelength along with quenching of the original emission band forming a ratiometric response. Based on dynamic light scattering (DLS) experiment and fluorescence lifetime measurement, we propose that the emergence of new emission band in the presence of HP2O73- ion is due to the aggregation-induced excimer formation.
RESUMO
Meso-3,5-bis(trifluoromethyl)phenyl picket calix[4]pyrrole 1 displays excellent fluoride anion transport activity across artificial lipid bilayers showing EC50 = 2.15 µM (at 450 s in EYPC vesicle) with high fluoride over chloride ion selectivity. The high fluoride selectivity of 1 was ascribed to the formation of a sandwich type π-anion-π interaction complex.
RESUMO
Diagnostic dilemma owing to radiological similarities between smear negative pulmonary tuberculosis and bronchogenic lung cancer pose a critical problem of late detection of the later with all its impact on the life of the victims.The aim of the study was to assess the magnitude and consequence of diagnostic dilemma between lung cancer and smear negative pulmonary tuberculosis. The retrospective observational study was conducted in the radiotherapy department of RG Kar Medical College and Hospital, Kolkata, West Bengal involving the lung cancer patients reported from February, 2009 to March, 2011. Out of the 76 lung cancer patients, 39.47% had exposure to anti tuberculosis treatment (ATT) before the actual diagnosis of lung cancer. Significantly higher proportion of rural patients was put on the ATT compared to their urban counterpart. Duration of symptoms before arrival was found significantly more among those who got ATT. Presence of any history of tuberculosis within the family was found to have significant association with the exposure to ATT before diagnosis as lung cancer. So in conclusion the treating physician must think twice before stamping a case as smear negative tuberculosis based on the radiological findings. High index of suspicion should also be maintained during treatment and follow-up of both smear positive and smear negative pulmonary tuberculosis as because the lung cancer may be preceded by or coexist with pulmonary tuberculosis.
