We present a femtosecond broad-band fluorescence up-conversion study of the vibrational relaxation dynamics of two UV chromophores, 2,5-diphenyloxazole (PPO) and para-terphenyl (pTP), pumped with a large excess of vibrational energy (>2000 cm(-1)). The band narrowing of the transient fluorescence spectrum reflects a biphasic cooling process in a few hundreds of fs and a few ps. In the sub-ps re...

Abstract This paper presents an optimal and efficient design of low pass digital finite impulse response (FIR) filter using hybrid predator prey optimization (HPPO) technique. HPPO is an evolutionary algorithm that exhibits the features of basic PPO, hooke jeeves exploratory move and opposition based strategy that helps to design an optimal filter. Predator Prey Optimization is a global search ...

Plasma-etching is a powerful tool in the determination of the resistance of the sublayer of skinned asymmetric hollow fiber membranes of poly (2,6-dimethyl-1,4-phenylene oxide). Using a resistance model and data provided by etched hollow PPO fiber membranes it is possible to predict the ultimate selectivity of the total membrane for helium over nitrogen and oxygen over nitrogen. From this model...

Studies have shown that the lowest performing physicians in pay-for-performance (P4P) programs improved the most; however, it is unclear whether this would occur without the P4P program or be sustained. The objective of this study is to investigate the impact of P4P in a Preferred Provider Organization (PPO) on low performing physicians over a 4-year period. We used administrative claims data f...

Amphiphilic poly(ethylene oxide)–poly(propylene oxide) (PEO–PPO)-based copolymers are thermoresponsive materials having aggregation properties in aqueous medium. As hydrosolubilizers of poorly water-soluble drugs and improved stability of sensitive agents, these materials have been investigated for improvement in solubility, stability, release and bioavailability of drugs. The goal of the prese...

Lineal (poloxamers or Pluronic®) or X-shaped (poloxamines or Tetronic®) amphiphilic tri-block copolymers of poly(ethylene oxide) and poly(propylene oxide) (PEO-PPO-PEO) have been broadly explored for controlled drug delivery in different regenerative medicine approaches. The ability of these copolymers to self-assemble as micelles and to undergo sol-to-gel transitions upon heating has endowed t...

Calculations of the conformational preferences of isolated single chains of poly(2,6-dimethylphenylene oxide) (PPO) and bisphenol-A polycarbonate (PC) predict that the rings of both chains are nearly free rotors a t room temperature. However, experimental dipolar rotational spin-echo 13C NMR shows that in the glass, the rings of PPO execute only small-amplitude motions while those of PC undergo...

Polyphenoloxidase (PPO; EC 1.14.18.1) extracted from Mentha arvensis leaves was isolated by (NH4)2SO4 precipitation and extensive dialysis. Its optimum pH and temperature varied with the substrate. The PPO showed activity with various diphenols. Km values were found 0.825, 0.928 and 7.41mM for caffeic acid, 4-methylcatechol and catechol, respectively. On heat-inactivation, half of the activity ...

Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance (1H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic bro...