Rice starch is used as an additive in various food and industrial products. With the inherent merits of small and uniform size distribution of rice starch and its white color and clean odor, deserts and bakery products are some of the favorable applications among processed foods [1]. The small granular size of the starch imparts it soft texture, high water retention and low syneresis, suggesting the possibility in using rice starch as fat substitute [2]. Rice protein in the endosperm, however, tightly associates on the surface of starch granules and the difficulty in removing the protein makes the starch isolation more costly compared to other starches [3].Rice protein which accounts for 7-8 % (DB) in the milled rice kernel is classified into four types: alkali-soluble glutelins (80 %), water-soluble albumins (9-11 %), salt-soluble globulins (7-15 %) and alcohol-soluble prolamins (2-4 %) [4]. Among those, albumin and globulin existing in the aleurone layer are usually removed during milling. But heterogeneous large molecules of glutelins exist inside the rice endosperm in the forms of protein bodies [5][6][7][8]. These spherically shaped protein bodies bind strongly to the compound starch granules with strong disulfide bonds and/or hydrophobic bonds [9, 10].To isolate rice starch, alkaline solvents, surfactants or protein hydrolyzing enzymes could be used to remove rice protein from rice flour [11]. Alkaline solvents such as NaOH and surfactants such as dodecylbenzene sulfonate (DoBS) and sodium lauryl sulfate (SLS) are commonly used in the protein extraction for starch isolation. These solvents destruct the oligomeric protein structures and transform them 120 Starch/Stärke 51 (1999) Nr. 4, S. 120-125When the extraction in 0.2 % NaOH was repeated four times (1 h for each step) at 25°C, the residual protein content in the isolated rice starch was 0.9 % (DB), equivalent to 86 % removal of the rice protein.Raising the extraction temperature slightly increased the protein solubility, but starch loss also became significant. Among the solutions, DoBS was most effective in removing rice protein whereas SLS was least. The residual protein content had a critical role in determining the pasting characteristics of the isolated starch, showing a negative correlation to the peak viscosity of the starch paste, but a positive correlation to the pasting temperature.* Journal Paper No. CAFST 97010 of Korea University.

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The purpose of this project was to study the effect of chitosan microsphere-encapsulated human growth hormone, which causes sustained release of chitosan and human growth hormone after implantation on early bony consolidation in distraction osteogenesis of a canine model. Forty-eight dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy, and the mandibular distraction was started 5 days after the operation at a rate of 1 mm/d up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan microsphere group (III), and chitosan microsphere-encapsulated human growth hormone group (IV). Normal saline was injected in group I. In group II, a 1-ml volume of hyaluronic acid solution was injected into the distracted area. In the group III, powder of chitosan microspheres and hGH were mixed with a 1-ml volume of hyaluronic acid to make an injectable form, and it was implanted into the distracted area. In group IV, powder of chitosan microsphere-encapsulated hGH was mixed with a 1-ml volume of hyaluronic acid. A total of 1-ml volume of the solution mix was implanted into the distracted area. Five dogs in each group (total of 20 dogs) were killed 3 weeks after completion of distraction. Twenty-eight dogs were killed at 6 weeks. Bone mineral density was 13.1% of the contralateral normal mandible at 3 weeks and 29.6% at 6 weeks in group I, 16.4% at 3 weeks and 40.4% at 6 weeks in group II, 16.6% at 3 weeks and 45.95% at 6 weeks in group III, and 29.6% at 3 weeks and 66.7% at 6 weeks in group IV. The mean three-point failure load was 16.1% in the control group, 34.7% in group II, 41.5% in group III, and 52.1% in group IV compared with the intact contralateral mandible, with statistical significance. In the histological findings, new bone was generated in all groups. In group IV, the formation of active woven bone was observed throughout the distracted area at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV, group III, group II, and the control group. In conclusion, these findings suggest that chitosan microsphere-encapsulated hGH seems to be quite effective in early bone consolidation in distraction osteogenesis.

SUMMARYThe integration of wireless local area networks (WLANs) and third generation (3G) cellular networks has been recently a subject of great interest, mainly aimed at augmenting cellular networks with high-rate data services by WLANs in hotspots. The complementary characteristics of 3G cellular networks and 802.11 WLANs are expected to offer the best of both technologies. On the other hand, the drastically different characteristics of both networks could be a serious obstacle to providing seamless mobility in the integrated WLAN and cellular networks. In particular, mobile users suffer from a drastic decrease in data rate after a vertical handoff from a WLAN to a 3G cellular network. However, current TCP congestion control cannot adapt to the change in the data rate after the vertical handoff, resulting in significant throughput degradation. Thus, we propose a novel TCP scheme to enhance the throughput when a vertical handoff occurs from a WLAN to a cellular network. For the proposed scheme, the throughput performance is investigated via analytic modeling and simulation.

A deterministic production and transportation planning problem is considered over a finite time horizon for two products that can be produced in each of two regions. Each region uses its own facility to supply the demands for two products. Demands for product 2 in one region can be satisfied either by its own production or by transportation from other region, while no transportation between two regions is allowed for product 1. Production, inventory and transportation costs are assumed to be non-decreasing and concave. The objective is to find the schedule of production and transportation in each region by which the total cost over the horizon is minimized. Using a network flow approach, we develop a dynamic programming algorithm that can find an optimal policy.