Polyamide-Scorpion Cyclam Lexitropsins Selectively Bind AT-Rich DNA Independently of the Nature of the Coordinated Metal

Cyclam was attached to 1-, 2- and 3-pyrrole lexitropsins for the first time through a synthetically facile copper-catalyzed “click” reaction. The corresponding copper and zinc complexes were synthesized and characterized. The ligand and its complexes bound AT-rich DNA selectively over GC-rich DNA, and the thermodynamic profile of the binding was evaluated by isothermal titration calorimetry. The metal, encapsulated in a scorpion azamacrocyclic complex, did not affect the binding, which was dominated by the organic tail

Blood cultures in paediatric patients: A study of clinical impact

Purpose : Blood cultures form a critical part of evaluation of patients with suspected sepsis. The present study was undertaken to study the risk factors, duration of incubation for obtaining positive cultures, and the clinical impact of the culture report. Methods : A total of 220 samples from 107 pediatric patients presenting with suspected bacteraemia were processed aerobically. Results : Cultures were positive in 18.7% of the samples. Most of the positive cultures were obtained after 24 hours of incubation of the broth and no isolates were obtained beyond day 4 of incubation. Therapy was modified in 54.23% of the patients after receipt of culture report. Conclusions : Incubation beyond four days (unless with specific indication like enteric fever) may be unnecessary for issuing a negative culture report. Repeated isolation of doubtful pathogens confirms true bacteraemia. Early culture report increases therapeutic compliance

Mass-size distribution of PM10 and its characterization of ionic species in fine (PM2.5) and coarse (PM10-2.5) mode, New Delhi, India

Size distribution of PM10 mass aerosols and its ionic characteristics were studied for 2 years from January 2006 to December 2007 at central Delhi by employing an 8-stage Andersen Cascade Impactor sampler. The mass of fine (PM2.5) and coarse (PM10-2.5) mode particles were integrated from particle mass determined in different stages. Average concentrations of mass PM10 and PM2.5 were observed to be 306 ± 182 and 136 ± 84 μg m-3, respectively, which are far in excess of annual averages stipulated by the Indian National Ambient Air Quality Standards (PM10: 60 μg m-3 and PM2.5: 40 μg m-3). The highest concentrations of PM10-2.5 (coarse) and PM2.5 (fine) were observed 505 ± 44 and 368 ± 61 μg m-3, respectively, during summer (June 2006) period, whereas the lower concentrations of PM10-2.5 (35 ± 9 μg m-3) and PM2.5 (29 ± 13 μg m-3) were observed during monsoon (September 2007). In summer, because of frequent dust storms, coarse particles are more dominant than fine particles during study period. However, during winter, the PM2.5 contribution became more pronounced as compared to summer probably due to enhanced emissions from anthropogenic activities, burning of biofuels/biomass and other human activities. A high ratio (0.58) of PM2.5/PM10 was observed during winter and low (0.24) during monsoon. A strong correlation between PM10 and PM2.5 (r 2 = 0.93) was observed, indicating that variation in PM10 mass is governed by the variation in PM2.5. Major cations (NH4 +, Na+, K+, Ca2+ and Mg2+) and anions (F-, Cl-, SO4 2- and NO3 -) were analyzed along with pH. Average concentrations of SO4 2- and NO3 - were observed to be 12.93 ± 0.98 and 10.33 ± 1.10 μg m-3, respectively. Significant correlation between SO4 2- and NO3 - in PM1.0 was observed indicating the major sources of secondary aerosol which may be from thermal power plants located in the southeast and incomplete combustion by vehicular exhaust. A good correlation among secondary species (NH+, NO3 - and SO4 2-) suggests that most of NH4 + is in the form of ammonium sulfate and ammonium nitrate in the atmosphere. During winter, the concentration of Ca2+ was also higher; it may be due to entrainment of roadside dust particles, traffic activities and low temperature. The molar ratio (1.39) between Cl- and Na+ was observed to be close to that of seawater (1.16). The presence of higher Cl- during winter is due to western disturbances and probably local emission of Cl- due to fabric bleaching activity in a number of export garment factories in the proximity of the sampling site