Absorbability of Calcium From Common Beans

Absorption of calcium from white, red, and pinto beans, labeled with ⁴⁵Ca, was measured in 24 women in a three-way randomized design using a calcium load of 72 mg and milk as the referent. Fractional absorption for the three beans averaged 0.219 ± 0.047 and did not differ by type. Milk calcium absorption at the same load was more than two times higher, 0.451 ± 0.088 (P < 0.001). Oxalate content averaged 0.34%, and phytate averaged 1.7%, a stoichiometric excess relative to calcium. To evaluate the relation of phytate to reduced absorbability, labeled pinto beans were pre-treated with phytase and fed to 10 subjects. Fractional absorption rose, averaging 0.318 ± 0.071, (P <0.01 vs. untreated beans), but was significantly below that of milk. The difference was partly accounted for by phytate, with the remainder probably due to relatively high oxalate.     

Circuit topologies for single-phase voltage-doubler boostrectifiers

A new family of single-phase voltage-doubler PWM (pulse width modulated) boost rectifiers is presented. By examining the switching states of several standard single-phase boost rectifier circuits, three characteristic PWM voltage switching patterns are identified: unipolar PWM; bipolar PWM; and phase-adjusted unipolar PWM. From this analysis, an equivalent family of voltage-doubler rectifiers is derived. When high output voltages are required, voltage-doubler rectifiers are shown to be able to generate AC line currents with the lowest current distortion. The circuits presented are examined using circuit simulators and experimental results     

Dynamic digital holographic wavelength filtering

This paper describes the theory and results of a new generic technology for use in optical telecommunications and wavelength division multiplexing (WDM): dynamic digital holographic wavelength filtering. The enabling component is a polarization-insensitive ferroelectric liquid crystal (FLC) spatial light modulator (SLM) in conjunction with a highly wavelength-dispersive fixed diffractive element. The technology has been used to perform demultiplexing of single or multiple WDM signals, dynamic erbium doped fiber amplifier (EDFA) gain equalization and channel management, and used to tune an erbium-doped fiber laser (EDFL) functioning as a high power, very narrow linewidth WDM source     

Intracellular analysis of relations between the slow (< 1 Hz) neocortical oscillation and other sleep rhythms of the electroencephalogram

The newly described slow cortical rhythm (approximately 0.3 Hz), whose depolarizing-hyperpolarizing components are analyzed in the preceding article, is now investigated from the standpoint of its relations with delta (1-4 Hz) and spindle (7-14 Hz) rhythmicity. Regular-spiking and intrinsically bursting cortical neurons were mostly recorded from association suprasylvian areas 5 and 7; fewer neurons were also recorded from pericruciate motor and posterolateral visual areas. Although most cells were investigated under various anesthetics, a similar slow cortical rhythm was found in animals with brainstem transection at the low- or high-collicular levels. These cerveau isolé (isolated forebrain) preparations display the major sleep rhythms of the EEG in the absence of general anesthetics. In 38% of recorded cortical neurons (n = 105), the slow rhythm was combined with delta oscillation. Both cellular rhythms were phase locked to the slow and delta oscillations in the surface- and depth-recorded EEG. In a group of this cell sample (n = 47), delta activity occurred as stereotyped, clock-like action potentials during the interdepolarization lulls of the slow rhythm. In another neuronal subsample (n = 58), delta events were grouped in sequences superimposed upon the depolarizing envelope of the slow rhythm, with such sequences recurring rhythmically at approximately 0.3-0.4 Hz. The associations between the two cellular and EEG rhythms (1-4 Hz and 0.3-0.4 Hz) were quantified by means of autocorrelograms, cross-correlograms, and spike-triggered averages. In 26% of recorded neurons (n = 72), the slow rhythm was combined with spindle oscillations. Regular-spiking cortical neurons fully reflected the whole frequency range of thalamically generated spindles (7-14 Hz). However, during similar patterns of EEG spindling, intrinsically bursting cells fired grouped action potentials (with intraburst frequencies of 100-200 Hz) at only 2-4 Hz. The dependence of the slow cortical oscillation upon the thalamus was studied by lesions and stimulation. The slow rhythm survived extensive ipsilateral thalamic destruction by means of electrolytic lesions or kainate-induced loss of perikarya in thalamic nuclei that were input sources to the recorded cortical neurons. To further prevent the possibility of a thalamic role in the genesis of the slow rhythm, through the contralateral thalamocortical systems and callosal projections, we also transected the corpus callosum in thalamically lesioned animals, and still recorded the slow rhythm in cortical neurons. These data indicate that the thalamus is not essentially implicated in the genesis of the slow rhythm.(ABSTRACT TRUNCATED AT 400 WORDS)     

MEASUREMENT OF THE SPECIFIC SURFACE AREA OF POWDERS BY THIN LAYER WICKING

The specific surface areas (A) of different clay mineral powders were measured by both the BET method and by thin layer wicking. The values of A for the BET and the wicking experiments coincided within a few percent. Thus, the simple and inexpensive thin layer wicking approach may well suffice to obtain reliable specific surface area values for most powders. From the wicking data it is also possible to obtain a rough estimate of the average particle size.     

Use of gas plasmas to increase breakdown strengths in polycarbonatefilm/foil capacitors

It is shown that the electrical breakdown voltages of polycarbonate film/metal foil capacitors can be increased. This can be achieved by briefly exposing the metal foil in these spirally wound film foil sections to a low-pressure, low-temperature gas plasma. Exposure of tin/lead foil to a 96% CF₄/4% O₂ gas plasma for four min, for example, produced >500% increase in breakdown voltage of sealed polycarbonate capacitors     

Excessive closure of the right eye: a new sign of infarction in the territory of the ipsilateral right middle cerebral artery

In right middle cerebral territory infarction a new sign, excessive closure of the right eye ipsilateral to the lesion and mild closure of the left eye on command, was noted. The excessive ipsilateral eye closure was not observed on spontaneous eye closure.