Identification of potent inhibitors of Plasmodium falciparum plasmepsin II from an encoded statine combinatorial library

An encoded 13,020-member combinatorial library was synthesized containing a statine core. Evaluation of this library with plasmepsin II, an aspartyl protease required for hemoglobin metabolism in the malaria parasite, led to the identification of potent and selective inhibitors as well as novel structure-activity relationships.     

The effect of nitrogen dioxide exposure on the release of surfactant isolated from neonatal rabbit type II pneumocytes in culture

Nitrogen dioxide (NO2) is a well-known environmental air toxin, produced from a variety of sources, including cigarette smoke. Because of the growing knowledge of the harmful effects of passive smoking on children, we decided to study the effect of NO2 exposure on the release of surfactant from isolated neonatal type II pulmonary epithelial cells. After isolation from 1 to 4 day old rabbits, type II epithelial cells were allowed to adhere for 18 hours, washed, media changed, and were exposed to either 5% CO2 in room air or NO2, 5 ppm, for 2 hours (all results mean +/- sd; comparisons, paired t-test). There was no difference in cell number or viability prior to exposure. Cells exposed to NO2 had an increase in LDH release [LDH activity in media/(LDH in media+cells) x 100], air 12.6 +/- 2.2%, NO2 21.7 +/- 3.7%, (p < 0.05). NO2-exposed cells also had an increase in total phospholipid (microgram/cell culture dish) in media compared to air exposed, air 170.13 +/- 7.54, NO2 195.15 +/- 11.2, (p < 0.05). 3H-choline incorporation as a precursor to disaturated phosphatidylcholine (DSPC) was also conducted during exposure to either air or NO2. Incorporation of 3H-choline into surfactant lipid was increased in media from cells after NO2 exposure compared to air, 58.23 +/- 15.16 air, 76.81 +/- 19.86 NO2 (cpm/microgram protein; p < 0.05). These results show that 2 hours of 5 ppm NO2 exposure is associated with an increase in release of surfactant from neonatal type II cells in culture.     

Gray-scale ultrasound: utility preoperatively and postoperatively in a patient with obstructive jaundice

We present a case of obstructing calculi of the common bile duct diagnosed by ultrasonography. Postoperatively, a sterile abscess due to bile leakage at the distal common bile duct developed, and was also diagnosed by ultrasound Ultrasonography was useful in following the course of clearing of the bile collection. Preoperative ultrasound evaluation of the jaundiced patient should be followed by postoperative sonography, especially if complications occur.     

On the dynamics of taut mooring systems

The dynamics of vertical tauttethers for compliant offshore platforms are assessed using three types of dynamic analysis and the resulting models are compared. An analytic linear model is derived as a basis for comparison with a linear modal analysis as well as with both linear and nonlinear finite element models. It is shown that the linear finite element analysis can predict the behaviour of the continuous tether with adequate accuracy over the frequency range of interest. The finite element model is subsequently used to study the effect of spatial variation of tether tension due to self-weight and square law damping. The validity of equivalent energy dissipative linearization is investigated.     

Microwave conductivity of thick-film conductors

The letter presents the results of an investigation aimed at minimising losses in thick-film screen-printed microstrip circuits. The Q factor of closed resonators of 30 ? and 50 ? impedances has been measured over the 1?10 GHz range. It is found that the effective r.f. conductivity is about one half that of bulk material over the major portion of the band considered.     

Action of phenols on the corrosion of 3S aluminium in hydrochloric acid solutions

The inhibiting effect of some phenols on the corrosion of iron in 0.5 N hydrochloric acid depends from the concentration and the constitution of the particular inhibitor. The effect decreases in the following order; p-thiocresol > pyrogallol > resorcinol > phenol > p-cresol > m-cresol > o-cresol. The low inhibiting power of the cresols appears to be due to the cresol appears to be due to the electron donating capacity of th CH₃ groups and their interaction with OH groups which is an electron donator, too. The SH and OH groups appear to facilitate the adsorption on cathodic sites as do the π-electrons of the aromatic annulus.     

Thermal degradation of methoxyanisole-1,2-dichloroethane resins

Thermal behaviour of m-methoxyanisole-1,2-dichloroethane resins was studied at different heating rates. Kinetic parameters for the decomposition of the resins have been determined from TG and DTA studies using various methods of thermal analysis. The first stage of degradation had E₁ ～ 3, the second stage had E₂ ～ 28 and the overall degradation had E₁₂ ～ 36 kcal·mol^?1, respectively.     

Acrylic Homo- and Co-polymers Based on 2, 4-dichlorophenyl Methacrylate and 8-quinolinyl Methacrylate

The monomer 2, 4-dichlorophenyl methacrylate (2,4-DMA) was synthesized from 2, 4-dichlorophenol and characterized by conventional methods. The homopolymers of 2,4-dichlorophenyl methacrylate and its copolymers with 8-quinolinyl methacrylate (8-QMA) in different feed ratio were prepared by free radical polymerization using dimethyl formamide (DMF) as a solvent and 2,2-azobis iso butyronitrile (AIBN) as an initiator. The resulting polymers were characterized by using IR spectroscopy. Reactivity ratios of monomer were evaluated using UV-spectroscopy. Average molecular weights and polydispersity were determined by gel permeation chromatography (GPC). Solution viscosity was also obtained. The thermal analysis was carried out using TGA and DSC. The homo- and co-polymers were also tested for their antimicrobial properties against selected microorganism. The metal ion uptake capacity of synthesized copolymers was estimated by batch equilibration method using different metal ion solution under different experimental conditions. It is observed that due to the presence of pendant ester bound quinoline group, the copolymers are capable of adsorbing cations from their aqueous solution.     

Pre-partitioning as a means of enhancing pairwise interchange solutions to quadratic assignment problems

Two partition/interchange processes are described for solving quadratic assignment problems. Explicit partitioning is used in both methods to decompose the initial large graph into several smaller graphs for initial placement and subsequent interchange optimization. Comparative runs were made between the two processes and against the interchange process without partitioning on problems involving up to 100 vertices. The comparative results clearly establish the effectiveness of partitioning in enhancing the performance of interchange processes and provide a basis for selecting partitioning processes.While the two methods described herein were developed for microcircuit placement problems, they are applicable to quadratic assignment problems arising from numerous other settings.     

Theory on long time delays, Q-switching and related phenomena in GaAs junction lasers

We present a theory that explains long time delays. Q-switching and related phenomena in GaAs junction lasers, based only on processes known to occur in these lasers.