Polyhydroxy chalcones and flavanones as antioxidants for edible oils

A series of 11 polyhydroxy chalcones, and in 4 cases, flavanones derived from them by isomerisation, some of which occur naturally in plant tissues, have been shown to be potent antioxidants for lard. Most of these compounds, not being commercially available, were prepared synthetically. Two of them, 3′,3,4-trihydroxy- and 2′4′,2,3-tetrahydroxy chalcone, are described for the first time.3,4-Dihydroxy chalcones, such as butein and okanin, are particularly effective antioxidants in the range of concentrations 0·025–0·1%, as judged by induction period measurements. Chalcones are more effective than the corresponding flavanones.The hypothesis is put forward that the effectiveness of 3,4-dihydroxy chalcones is dependent on the formation of extended forms of resonance-stabilised free radicals.     

A 2.6-GByte/s multipurpose chip-to-chip interface

A 2.6 GByte/s megacell that interfaces to single or double byte wide DRAMs or logic chips is implemented using 0.35-0.18 μm CMOS technologies. Special I/O circuits are used to guarantee 800 Mbit/s/pin data rate. Microwave PC board design methodologies are used to achieve the maximum possible interconnect bandwidth     

Reductive cleavage of the disulfide bonds of the collagen IV noncollagenous domain in aqueous sodium dodecyl sulfate: absence of intermolecular nondisulfide cross-links

OBJECTIVES: The goal of this study was to develop an accurate, simplified proximal isovelocity surface area (PISA) method for calculating volume flow rate using lower blue-red interface velocity produced by a color Doppler zero baseline shift technique. BACKGROUND: The Doppler color proximal isovelocity surface area method has been shown to be accurate for calculating the volume flow rate (Q) across a narrowed orifice by the formula Q = PISA x Blue-red interface velocity. A hemispheric model is generally used to calculate proximal isovelocity surface area (PISA = 2 pi a2, where a = the radius corresponding to the blue-red interface velocity). Although a hemispheric model is simple, requiring measurement of one radius, it may underestimate the actual volume flow rate because, in the general case, the shape of a proximal isovelocity surface area is hemielliptic. Although a hemielliptic model is generally more accurate for calculating proximal isovelocity surface area, it is more complex, requiring measurement of two orthogonal radii. METHODS: Sixteen in vitro constant flow model studies were performed using planar circular orifices (diameter range 6 to 16 mm). The blue-red interface velocity was changed from 3 to 54 cm/s using color Doppler zero baseline shift. RESULTS: 1) With decreasing blue-red interface velocity, the size of the proximal isovelocity surface area was increased, and its shape changed from hemielliptic to hemispheric. 2) With the blue-red interface velocity in the range 11 to 15 cm/s, the proximal isovelocity surface area became nearly hemispheric; however, it was difficult to determine the blue-red interface radius at a blue-red interface velocity < 10 cm/s because of interface fluctuations. 3) Calculated volume flow rate using the hemispheric proximal isovelocity surface area model with a single radius was relatively accurate at a blue-red interface velocity of 11 to 15 cm/s (mean percent difference from actual volume flow rate was -3.6%). CONCLUSIONS: Because the shape of the proximal isovelocity surface area is nearly hemispheric at a blue-red interface velocity of 11 to 15 cm/s, volume flow rate can be accurately calculated in this proximal isovelocity surface area interface velocity range (produced by zero baseline shift) by measuring a single-interface radius. This approach should be clinically useful for calculating the volume flow rate across stenotic and regurgitant valves and across shunt defects.     

Tissue response to nano-hydroxyapatite/collagen composite implants in marrow cavity

The formation of otoconia in the endolymphatic sac (ES) of the larval newt, Cynops pyrrhogaster, has been studied by light and transmission electron microscopy. Some of the epithelial cells of the ES contain an abundance of swollen vesicles, Golgi complexes, rough endoplasmic reticula and ribosomes at the late larval stages 50 and 51, approximately 26-30 days after eggs are laid. Five days later, at stage 52, crystals are present in the vacuoles between the epithelial cells. Serial sections indicate that these vacuoles actually form small canals which lie in the wall and join the lumen of the ES. Reconstruction of the ES shows that several canals are contained in the ES wall. At stage 56, about 72 days after eggs are laid, a large number of otoconia are present in the ES lumen, while the otoconia disappear from the canals. It appears that the otoconia are first produced in the canals and then released to the lumen. Some epithelial cells of the ES are thought to expel the organic and inorganic material to the canals to form the otoconia in situ. The process of formation of the otoconia in the ES is discussed.     

Processing/morphology correlations in poly(benzoate-co-naphthoate) liquid crystalline polymers

The molecular orientation and disclination defects in injection molded bulk samples of liquid crystal polymers have been revealed by transmission electron microscopy (TEM). Using a recently optimized lamellar decoration and etch technique for use with poly(benzoate-co-naphthoate), we have studied in detail the skin-core morphology produced by realistic injection molding processing. In the skin, the director is observed to be highly aligned along the flow direction, and the defect density is very low (10 cm^?2). In the core, however, the defect density is six orders of magnitude greater, and the director lies predominantly in the plane defined by the flow and neutral directions. The flow during processing is turbulent, giving rise to distinct morphological features and disclination clusters. When the material is filled at 20% volume fraction with long glass fibers, the molecular and filler orientations are nearly parallel. Dimensional precision also correlates with the morphology and improves with increasing core fraction.     

Polycarboxylates in soda ash detergents

Calcium carbonate deposition on cotton fabric from soda ash-based detergents containing polycarboxylates is measured and related to polymer composition and molecular weight, under varying conditions of temperature, water hardness and detergent composition. Deposition effects on fabric are compared with threshold inhibition effects and calcium binding capacities of the polymers. Polyacrylic acids with molecular weights of 2000–5000 are most effective in preventing calcium carbonate deposition on fabric. A 1.5:1 acrylic acid:maleic acid copolymer is more effective than polyacrylic acid. Detergents with LAS left somewhat higher calcium carbonate deposits than detergents with a nonionic surfactant. Prevention of visible calcium carbonate precipitation in the absence of fabric (“threshold effects”) appears at polymer levels considerably lower than those necessary to prevent calcium carbonate deposition on fabric. Deposition on fabric can be prevented at levels of polymer much less than that necessary to bind most of the calcium ions, as determined by the calcium binding capacity. Presented at the AOCS meeting in New Orleans in May 1987.