Virological characterization and liver histology in HCV positive subjects with normal and elevated ALT levels

In a retrospective study of the pattern of drugs used in the initial treatment of hypertension, 300 case notes of hypertensive patients attending medical clinics at the Korle-Bu Teaching Hospital, Accra and whose treatment were initiated during the period 1973-1993, were reviewed. The mean age of patients was 55 years, mean pre-treatment systolic and diastolic pressures were 179.5 +/- 25. 5 and 108.5 +/- 14.2 mm Hg, respectively, with 85% of patients being female. The frequencies of individual drugs prescribed for the initial treatment of hypertension were: diuretics (90%), reserpine (46%), methyldopa (31%), and propranolol (30%). Single drug treatment was prescribed for 18%, two drugs for 60% and three or more (multiple drugs) for 22% of patients. The mean number of drugs per patient was 2.2 Patients prescribed multiple drugs had pre-treatment systolic and diastolic blood pressures which were significantly (p < 0.01) higher than those prescribed 2 drugs which were, in turn, higher (p < 0.001) than those prescribed single drugs. The results showed that during the period 1973-1993, diuretic based "stepped care" therapy was the main first line anti-hypertensive drug management regime. "Old" anti-hypertensive drugs were more commonly used than newer ones. The cost and availability drugs and the pretreatment blood pressure were probably the main determinants of the choice of the type and number of drugs prescribed.     

Electroosmotic flow in nanoporous membranes in the region of electric double layer overlap

This study investigates electroosmotic flow (EOF) with sodium tetraborate buffer in nanoporous anodized alumina membranes. Membranes with pore diameters ranging from 8 to 100 nm have been fabricated with narrow pore size distributions to systematically investigate the effect of pore diameter on the electroosmosis (EO) pumping down to the electric double layer overlap region. EOF was observed in membranes with pore diameters in and below this region, along with evidence of concentration polarization (CP), which resulted in a significant reduction in flux. The initial flux, though, could be fully recovered by temporarily reversing the flow and dislodging the accumulated ion layer from the feed side of the membrane. Stable pumping for up to 2 h was obtained before any flux reduction caused by CP was observed.     

Flash spark plasma sintering of 3YSZ

Flash SPS (FSPS) consolidation of 3YSZ cold pressed pellets was investigated. The results show that FSPS allows ultra-rapid consolidation of 3YSZ samples in 30–90 s under an applied electric field. The DC field induces electrochemical blackening. The partial reduction process starts from the cathode (-) and propagates toward the anode (+). This phenomenon, not previously discussed in FSPS literature, induces the development of internal temperature gradients resulting in a polarity dependent grain size/densification.     

Efficient discovery and optimization of complex high-throughput experiments

As the pace of experimentation in materials science and catalysis has increased, experimental tactics and strategies have had to adapt to meet the demands of goals of experimentalists, and the spaces they explore. This pace has increased from runs/year to runs/day and sometimes to runs/minute in high-throughput experimentation. Although much of this capacity is used to simply speed up conventional experimental designs, the leading-edge application is discovery of low-probability, high-value occurrences (hits) by searching extensive, complex experimental spaces. Conventional design of experiments (DoE) is not capable of dealing with these issues. Instead, more advanced experimental tactics and strategies must be implemented. After introducing the elements that make an experimental campaign complex, here we present a novel statistical model-based evolutionary experimental strategy and apply it to the optimization of a family of artificial complex systems. With our experiments, we show that such a strategy may significantly reduce the experimental effort required for finding the optima compared to other state-of-the-art evolutionary strategies.     

Vortex Molecules in Bose-Einstein Condensates

Stable vortex dimers are known to exist in coherently coupled two component Bose-Einstein condensates (BECs). We construct stable vortex trimers in three component BECs and find that the shape can be controlled by changing the internal coherent (Rabi) couplings. Stable vortex N-omers are also constructed in coherently coupled N-component BECs. We classify all possible N-omers in terms of the mathematical graph theory. Next, we study effects of the Rabi coupling in vortex lattices in two-component BECs. We find how the vortex lattices without the Rabi coupling known before are connected to the Abrikosov lattice of integer vortices with increasing the Rabi coupling. In this process, vortex dimers change their partners in various ways at large couplings. We then find that the Abrikosov lattices are robust in three-component BECs.     

Physical and thermal characterization of polylactic acid meltblown nonwovens

A series of polylactic acid (PLA) nonwovens were prepared by the melt blowing process using micro and nano dies. The nonwovens were characterized for structural, thermal, and mechanical properties. These properties varied with the type of die, airflow, and die to collector distance (DCD). The mean pore size for PLA microfiber ranged between 1.82 and 10.48 micrometers, and nanofiber nonwovens ranged between 452 and 818 nanometers. The tensile modulus and strength of PLA nonwovens increased with airflow at a given DCD, but decreased with increased DCD for a given airflow. Thermograms from calorimetry showed microfiber mats had a larger composition of beta‐form crystals than the nanofiber mats. The results showed that a wide range of nonwovens can easily be generated with properties tailored to the specific application. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40593.     

Impact behaviour of A356 alloy for low-pressure die casting automotive wheels

Instrumented impact strength tests have been carried out on KV sub-size Charpy samples drawn from A356 aluminium alloy 17-in. wheels, produced by a low-pressure die casting. The wheels show different geometry and thermal treatment. In this paper, the effects of microstructure and defects on the impact properties are studied. The results indicate that the impact energy is lower in as-cast wheel than in T6 heat-treated wheels. A finer microstructure always corresponds to higher impact strength, while a direct correlation between the resistance to crack propagation values and secondary dendrite arm spacing (SDAS) exists. Casting defects, revealed by means of X-ray and density measurements techniques, become critical when concentrated around the V-notch, where they reduce the load bearing area of Charpy specimens. The fracture profile and surface of Charpy specimens have been investigated revealing how the crack crosses the interdendritic eutectic region where a significant fraction of cracked eutectic silicon and intermetallic particles is found.Numerical simulations have been performed to study the filling and solidification behaviour of the alloy of the wheels analysed, in order to predict the final microstructure and shrinkage formation. Solidification times, estimated by means of SDAS measurements and calculated with a numerical simulation approach, show a good correspondence. Critical areas, as concern hot spots and shrinkage porosities, are generally revealed in the zone of the wheels between the spoke and the rim, as well as in the rim area.