A photoinduced pH jump applied to drug release from cucurbit[7]uril

A proof-of-principle for the application of a photoinduced pH jump for delivery of the Hoechst 33258 drug by disassembly of its host-guest complex with cucurbit[7]uril is described

Current opinions and recommendations of paediatric healthcare professionals - The importance of tablets:Emerging orally disintegrating versus traditional tablets

The appropriate prescribing of paediatric dosage forms is paramount in providing the desired therapeutic effect alongside successful medication adherence with the paediatric population. Often it is the opinion of the healthcare practitioner that dictates which type of dosage form would be most appropriate for the paediatric patient, with liquids being both the most commonly available and most commonly used. Orally disintegrating tablets (ODTs) are an emerging dosage form which provide many benefits over traditional dosage forms for paediatric patients, such as rapid disintegration within the oral cavity, and the reduction in the risk of choking. However the opinion and professional use of healthcare practitioners regarding ODT's is not known. This study was designed to assess the opinions of several types of healthcare professionals (n = 41) regarding ODTs, using a survey across two hospital sites. Results reaffirmed the popularity of liquids for prescribing in paediatrics, with 58.0% of participants preferring this dosage form. ODTs emerged as the second most popular dosage form (30.0%), with healthcare practitioners indicating an increasing popularity amongst patients in the hospital setting, belief with 63.0% of practitioners agreeing that many liquid formulations could be substituted with a suitable ODT. The desired properties of an ideal ODT were also identified by healthcare practitioners preferring a small, fast disintegrating tablet (90.2% and 95.1% respectively), with the taste, disintegration time and flavour being the three most important attributes identified (29.5%, 28.7% and 21.7% respectively). This study provided a pragmatic approach in assessing healthcare professional's opinions on ODTs, highlighting the ideas and thoughts of practitioners who are on the frontline of paediatric prescribing and treatment and gave an indication to their preference for ODT properties

A rain-rate retrieval algorithm for attenuated radar measurements

Adynamic regularization scheme for rain-rate retrievals from attenuated radar measurements is presented. Most regularization techniques, including the optimal estimation method, use the state-space parameters to regularize the problem, which will always lead to a bias in the solution. To avoid this problem the authors introduce an evolutionary regularization technique, which is based on the spatial derivative of the measured reflectivity profile and allows for a bias-free global solution. The regularization strength is determined by the quadratic eigenvalue solution using the regularized total least squares method. With the new method, the authors perform a retrieval of rain-rate profiles from simulated measurements of a nadir-pointing W-band (94 GHz) radar, in a configuration similar to the cloud radar employed on CloudSat. The simulations assume that multiple scattering is negligible and only liquid hydrometeors are taken into account. The authors compare the results of this method with the outcome of an optimal estimation method and demonstrate that their method is superior in terms of reliability, correlation coefficient, and dispersion to the optimal estimation method for layers experiencing high values of attenuation; therefore, the a priori bias typical for optimal estimation solutions is avoided. © 2010 American Meteorological Society

ESPT of 2-(2'-pyridyl)benzimidazole at the micelle-water interface: Selective enhancement and slow dynamics with sodium dodecyl sulfate

The effect of micellar environment on the excited state proton transfer (ESPT) of 2-(2'-pyridyl)benzimidazole (2PBI) has been investigated by steady state and time resolved fluorescence spectroscopy. The ESPT, which occurs to a rather small extent at pH 7, is found to be enhanced remarkably at the interface of sodium dodecyl sulfate (SDS) micelles and water. Such an enhancement is not observed for the cationic cetyl trimethyl ammonium bromide (CTAB) or neutral Triton X-100 micelles. This selective enhancement is explained in the light of a modification of pK(a) and a more acidic local pH in the micelle-water interface. A rise time of about 890 ps is observed in the region of tautomer emission. The origin of this rise time is explored, considering three factors, namely, diffusion controlled protonation of the normal form of 2PBI, slow and possibly incomplete solvation of the transition state, leading to a slowing down of the proton transfer process and a similar slow dynamics of the tautomeric excited state

Interaction of Lucifer yellow with cetyltrimethyl ammonium bromide micelles and the consequent suppression of its non-radiative processes

The interaction of the fluorophore Lucifer yellow with micelles has been monitored using steady state and time resolved fluorescence techniques. Contrary to the popular belief that the fluorophore is too polar to associate with the stern layer or hydrophobic core of micelles, we have observed that it binds with the micelles of the positively charged surfactant cetyl trimethyl ammonium bromide and that such interaction causes an decrease in the rates of its non-radiative processes. This phenomenon cannot be explained solely in the light of a reduced polarity, as we have demonstrated that the photophysics of Lucifer yellow is complex and intramolecular charge transfer does not seem to be the only excited state process that is operative.© Elsevie

A comparative life cycle energy cost analysis of photovoltaic and fuel generator for load shedding application

Comparative life cycle energy cost analysis for different electricity generators (photovoltaic generator, kerosene generator and diesel generator) used during load shedding is presented. The parameters considered for calculation of the unit cost of energy are: the discount rate, inflation rate, IREDA loan facility to promote PV, operation and maintenance cost of PV and fuel generator (FG) set and the associated fuel cost. It is found that the unit cost of PV electricity is comparable to or less than that of FG generated electricity at present market prices