Future developments in cosmetic formulations

In recent years, there have been a great deal of interest in applications of microemulsions, liposomes (vesicles) and multiple emulsions in cosmetic formulations. These systems will provide the cosmetic industry with new types of formulations which are easier to apply, better functional benefit and potentially safer formulations. Microemulsions are thermodynamically stable systems and hence shelf life is no problem. Many cosmetic ingredients can be adequately solubilized in the swollen micelles of the microemulsions. Such solubilized systems may enhance transport and diffusion through various barriers, eg., the skin, thus enhancing the efficacy of the formulations. However, microemulsions may cause skin irritation by disrupting the liquid crystalline structure of the stratum corneum. This problem may be overcome by formulating microemulsions, which on evaporation produce lamellar liquid crystalline structures. The problem of skin irritation is certainly reduced or eliminated using liposomes or vesicles, which offer an alternative to microemulsions. The principles for formation and stabilization of vesicles are discussed in this paper and research work is needed to produce nanocapsules from liposomes, using polymerizable surfactants. Multiple emulsions of the water/oil/water (w/o/w) or oil/water/oil (o/w/o) types are also valuable systems for formulating cosmetics. In the first place, they offer a means of sustained release of the various ingredients. Secondly, they allow one to separate the various ingredients in the formulation, thus preventing their possible interaction. The basic principles required for preparation of stable multiple emulsions are summarised. Developments of polymeric surfactants led to the formulation of stable multiple emulsions. An example of a recently formulated stable w/o/w multiple emulsion is given in this paper The stability of the system was investigated using optical microscopy. Creaming occurred on storage, particularly at high temperature (40°C) and this was significantly reduced by addition of Kelzan (a polysaccharide with high molecular weight). The final formulation was studied rheological techniques.     

Transient behavior of subthreshold characteristics of fullydepleted SOI MOSFETs

It has been found that the subthreshold currents of fully depleted silicon-on-insulator (SOI) MOSFETs show a transient behavior under certain front-gate and back-gate voltage conditions. The cause of this anomaly is explained, and applications for the phenomenon are pointed out. Particularly, a simple way to measure the silicon film thickness is suggested     

Highly compact AC-AC converter achieving a high voltage transferratio

This paper reports a new, highly integrated modular design approach for pulsewidth-modulation AC-AC converters based on a modular phase-bank structure. Novel high-power 3-in-1 integrated bi-directional power modules (IBPM) rated at 1200-V AC and 150 A and the 3-to-1 phase bank circuits have been successfully developed, fabricated and tested. This enables the modularity design of the multiphase converter systems and reduces the critical parasitic inductance. A theoretical analysis of the IBPM's silicon utilization for this new breed of direct power converters has been outlined. A lab prototype at medium power level has been successfully designed, implemented, and tested with good results. A nearly 460-VRMS out voltage at a 1:0.955 voltage transfer ratio, which, perhaps, is the highest performance reported so far in the literature, has been achieved by the novel two-side modulation control system. The converter-fed AC motor system is able to operate over the 0-240 Hz range with inherent regenerative capability and four-quadrant operation. Potential industrial applications are also briefly highlighted in this paper     

A novel therapeutic approach for rectal varices: a case report of rectal varices treated with double balloon-occluded embolotherapy

We present a patient with continuous melena, diagnosed as rectal varices bleeding. She had a history of esophageal varices, which was treated by endoscopic ligation therapy. Eight years after the treatment of esophageal varices, the continuous melena began. Colonoscopic examination showed that the melena was caused by rectal varices, which were so severe that they could not be treated by either endoscopic sclerotherapy or surgical devascularization. Taking into considering the overall risk of treating rectal varices, we chose the approach of double balloon-occluded embolotherapy (DBOE) with 5% ethanolamine oleate with iopamodol as a liquid embolic material. DBOE is one of the interventional radiology techniques (Morita et al., Acta Hepatol Jpn 1994;35:109-120), but in this case was a completely new and novel clinical procedure for rectal varices. After the DBOE therapy, the condition of rectal varices was markedly improved. Thus, DBOE might be a new tool for treating inoperable rectal varices.     

NOTCHED FATIGUE BEHAVIOUR OF TWO COLD ROLLED STEELS

Abstract— A SAE1010 plain carbon steel and a SAE945X HSLA steel were cold rolled to various thickness reductions. Centre notched specimens were tested under stress control at a stress ratio of—1. The effect of loading direction on the fatigue strength was examined. The notched specimen fatigue strength was only slightly increased by cold rolling, since two opposing factors: the smooth specimen fatigue strength and the notch sensitivity, were increased by cold rolling. The notched specimen fatigue strength in the transverse direction was approximately the same as that in the longitudinal direction. An empirical equation and equations derived from fracture mechanics and Neuber's rule were applied to predict the fatigue notch factor for the sharp and blunt notch geometries examined. A reasonable agreement between the predictions and the experimental results was observed for the sharp notches. For the blunt notches, the predicted fatigue notch factors were conservative.     

Modeling of multilevel converters

In this paper, the imbricated cells multilevel converters are studied and modeled from a control viewpoint. These converters make use of several switches connected in a series, which allows using switches with reduced voltage ratings; these low voltage switches have lower conduction losses and can switch at higher frequency. In addition to this feature common to all converters using series connected switches, the control signals of multilevel converters can be phase shifted to increase the apparent switching frequency and improve the dynamic performances of the whole converter. It is shown that a multilevel inverter leg, composed of p pairs of switches and p-1 capacitors, forms a multivariable nonlinear system that cannot be properly modeled by standard methods such as state-space averaging. The transient behavior of this system depends on the current harmonics and their phase shift with the different control signals. A specific model is detailed, studied, and used to illustrate the properties of these converters. In particular, the natural balancing of the voltage across the switches is demonstrated and the time constants involved in this process are determined     

Cardiac papillary fibroelastoma excision combined with reconstructive surgery

1. The effect of the aqueous extract of Cissus sicyoides (CS) on isolated guinea pig aortic rings was studied. CS contracts the smooth muscle of the aorta in a dose-response relation. 2. The extract of CS increases the norepinephrine contraction in normal calcium and in solutions without calcium. 3. Lanthanum inhibits the contraction induced by CS. 4. The vasoconstrictor effect of CS was increased in solutions without calcium or with low calcium, which is an inverse calcium-dependent contraction. 5. Prolonged exposure to calcium-free solution did not abolish CS contraction. These contractions can be elicited repeatedly even after 6 hr of continuous exposure to calcium-free solutions. 6. Caffeine reduces contractile response induced by CS in normal calcium, as well as in solutions without calcium. 7. Our results support the idea that the aqueous extract of CS acts at the membrane level, increasing the calcium entry through the membrane as well as acting on the internal calcium deposits, possibly on the sarcoplasmic reticulum.