• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.84-90
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• 2001

This study was performed to know the effect of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$ on intestinal environment, Rats were fed with diets containing $1\%$, $5\%$, and $10\%$ of each depolymerized alginate (HAG-10, HAG-50, HAG-100 and alginate) for 35 days, The changes of weight, moisture content, pH and volatile basic nitrogen (VBN) of fecal, and a short chain fatty acids (SCFA) were checked in the rats. The fecal weight and moisture content were the highest in rats fed with alginate diets (p<0.01), followed by HAG-100, HAG-50 and HAG-10 in order. The $5\%$ of HAG-50 diets induced a significant increase in contents of protein and lipid of feces, resulting in the decrease of apparent digestibility of protein and lipid (p<0.01). The pH and VBN content in feces of the rats decreased in $5\%$ and $10\%$ of HAG-50 diets, but $10\%$ of HAG-100 diets; $5\%$ and $10\%$ of alginate diets brought about an increase of fecal pH and VBN (p<0.01), The amount of n-butyric acid in feces was increased while propionic and acetic acid contents decreased significantly (p<0.01) in diets containing $5\%$ and $10\%$ HAG-50. However, the feces of rat fed diet containing $5\%$ and $10\%$ alginate showed a tendency to being opposite in results than that of HAG-50.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.520-523
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• 2000

Anti-ulcer effects of depolymerized alginate (HAG-10, average molecular weight 10,000; HAG-50, average molecular weight 50,000; HAG-100, average molecular weight 100,000) obtained by hydrolysis of alginate by heating at $121^{\circ}C$, against $HCl{\cdot}ethanol$ and water-immersion stress in rats were investigated. The acute gastritis, induced by $HCl{\cdot}ethanol$, and the gastric ulcer, induced by water-immersion stress, were inhibited dose-dependently by administration of HAG-50, HAG-100 and alginate. Histopathological lesions of the gastritis and gastric ulcer in rats treated with HAG-50, HAG-100 and alginate were significantly lower than those in rats fed with HAG-10. The inhibition rates (${\%}$) on acute gastritis induced by $HCl{\cdot}ethanol$ and gastritis ulcer induced by water-immersion stress in rats, were $13.00{\%}\;and\;15.74{\%}$of HAG-10, $41.15{\%}\;and\;35.72{\%}$ of HAG-50, $41.58{\%}\;and\;35.37{\%}$ of HAG-100, and $45.17{\%}\;and\;41.11{\%}$ of alginate, respectively. These results suggested that HAG-50, HAG-100 and slginate had a protective effect against the gastritis and gastric ulcer. The effect was not as visible when using HAG-10 in rats. From the present results, it was suggested that HAG-50 was an effective anti-ulcer agent against $HCl{\cdot}ethanol$and water-immersion stress in rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.21-26
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• 2001

To examine functionality of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$ on gastrointestinal physiology, the changes of body weight, organ weight and length, pancreatic and small intestinal composition, and light microscopy (LM) observation of small intestinal microvilli's appearances were checked in the rats. Rats were fed diets containing $1\%, 5\%, and 10\%$ of each depolymerized alginate (HAG-10, HAG-50, HAG-100) and alginate for 35 days, The feeding of 5 and $10\%$ HAG-50 and $10\%$ alginate diets for 35 days significantly depressed the body weight gain, but increased the length and weight of the small intestine and cecum in rats (p<0.01). Pancreatic protease activity was decreased significantly (p<0.01) in all groups except lo/o of HAG-10 diets, but the protein content increased in all groups, However, pancreatic amylase and lipase activities as well as DNA and RNA content were not significantly different. The small intestinal protein and the DNA content were the highest in diets fed $5\%$ HAG-50; RNA content increased significantly (p<0.01) in all groups except in the fiber-free diets. Light microscopy (LM) observation showed growth of small intestinal microvilli with numerous ridges; the multiplication of the convolution goblet cells in rats fed with diets containing $5\%$ of HAG-50 were more than others group.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.388-392
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• 2000

To improve functionality and characteristics of alginate from the sea tangle, Laminaria japonicus, partially depolymerized alginates (HAG-10, average molecular weight 10,000; HAG-50, average molecular weight 50,000; HAG-100, average molecular weight 100,000) were obtained with hydrolysis of alginate by heating at $12^{\circ}C$. Effects of the depolymerization on physicochemical properties were investigated in the antimutagenicity and binding capacity of cholesterol, glucose and cadmium. In the Ames mutagenicity test using Salmonella typhimurium TA 100, HAG-10, HAG-50, HAG-100 and intact alginate reduced effectively the mutagenicities induced by aflatoxin $B_1 (AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and HAG-10 showed the strongest antimutagenicity among the tested samples. The binding capacity of cholesterol, glucose and cadmium at different pH in vitro depended highly on molecular weight of alginate, and the changes in binding capacity at different pH was not different.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.393-398
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• 2000

To extend utilization of alginate from the sea tangle, Laminaria japonicus, depolymerized alginates (HAG-10, average molecular weight 10,000; HAC-50, average molecular weight 50,000; HAG-100, average molecular weight 100,000) were obtained by hydrolysis of alginate by heating at $12^{\circ}C$. The effects of each depolymerized alginate on excretion of cholesterol, glucose and namium in rats were investigated. The total excretion rate (${\%}$) of cholesterol and cadmium was the highest in rats administered with HAG-50, The rate was $45.81{\%} and 59.02{\%} with HAG-50$. It was high in the order of $45.78{\%} and 56.05{\%}$ in HAG-100, $41.28{\%}$ and $55.96{\%}$ in alginate, and $32.11{\%} and 44.92{\%} in HAC-10$, respectively. In the case of HAG-50, it significantly (p<0.01) prevented the serum glucose level of rats from rising within 30 min and 60 min after glucose loading or administration among all the samples, but it had no particular effects on the serum insulin level. In conclusion, it was suggested that HAG-50, in which the alginate had a decreased molecular weight, while still retaining its desirable functions as a dietary fiber, was effective in excretion of harmful substances, such as cadmium and cholesterol, and in lowering glucose activities in serum of rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.77-83
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• 2001

To clarify functionality of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$ on gastrointestinal physiology, the effects of a depolymerized alginate on fecal microflora and the intestinal environment were studied in rats. Rats were fed with diets containing 1, 5 and $10\%$ of each depolymerized alginate (HAG-10, HAG-50 and HAG-100) and alginate for 35 days, Among 20 species of authentic intestinal bacteria, Bacteroides ovatus showed the abilities to ferment HAG-10 HAG-50, HAG-100 and alginate, The 1, 5 and $10\%$ of HAG-50 and $1\%$ of alginate diets resulted in the increased ratio of Bifidobacterium and Lactobacillus to total bacteria, while the 5 and $10\%$ alginate diets decreased in feces of rats, significantly (p<0.01). These results suggested that $5\%$ HAG-50 diets contribute to an improvement of intestinal microflora in rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.173-178
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• 2001

This study was performed to know the hypocholesterolemic effect of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$. The changes of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in serum, as well as the atherogenic index were elucidated in rats for 35 days. In order to evaluate single-dose toxicity of HAG-50 in rats via oral routes, induction any mortalities and abnormal signs in clinical finding, body weight, gross findings and histopathological finding, and estimation of $LD_{50}$ were elucidated. Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in the serum significantly decreased and resulted in the decrease of atherogenic index in rats fed diets containing $5\%\;and\;10\%$ HAG-50 (p<0.01). HAG-50 did not induce any mortalities and abnormal signs in clinical findings, body weights, gross findings and histopathological findings in single-dose toxicity test via oral routes of rats, after which it was impossible to estimate $LD_{50}$ values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8A
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• pp.702-711
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• 2011

This paper proposes a HAG(Hidden-Node-Aware Grouping) algorithm for IEEE 802.15.4 networks to enhance the performance by eliminating collisions resulted from the hidden node problem without adopting the RTS/CTS packet exchanges. To solve the hidden node problem, the HAG algorithm organizes nodes into disjoint transmission groups by dynamically allocating hidden nodes into separate groups which take turns in a round robin way for their transmission. For dynamic group adjustment, it periodically evaluates the presence of hidden nodes based on subordinate nodes' receipt reports. To accurately measure its behavior, this paper also builds an analytical model to estimate its throughput fluctuation over various network topologies. The mathematical model along with simulation results confirmed that the HAG technique gracefully degraded the throughput of IEEE 802.15.4 networks whereas the standard IEEE 802.15.4 networks suffer severe throughput fallout as hidden nodes become populated.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.81-91
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• 2014

This paper proposes hidden-node aware grouping (HAG) algorithm to enhance the performance of institute of electrical and electronics engineers (IEEE) 802.15.4 networks when they undergo either severe collisions or frequent interferences by hidden nodes. According to the degree of measured collisions and interferences, HAG algorithm dynamically transforms IEEE 802.15.4 protocol between a contention algorithm and a contention-limited one. As a way to reduce the degree of contentions, it organizes nodes into some number of groups and assigns each group an exclusive per-group time slot during which only its member nodes compete to grab the channel. To eliminate harmful disruptions by hidden nodes, especially, it identifies hidden nodes by analyzing the received signal powers that each node reports and then places them into distinct groups. For load balancing, finally it flexibly adapts each per-group time according to the periodic average collision rate of each group. This paper also extends a conventional Markov chain model of IEEE 802.15.4 by including the deferment technique and a traffic source to more accurately evaluate the throughput of HAG algorithm under both saturated and unsaturated environments. This mathematical model and corresponding simulations predict with 6%discrepancy that HAG algorithm can improve the performance of the legacy IEEE 802.15.4 protocol, for example, even by 95% in a network that contains two hidden nodes, resulting in creation of three groups.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.311-317
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• 2006

Phenolic compounds in safflower seeds were recently found to stimulate bone formation and increase plasma HDL cholesterol levels in estrogen deficient rats, and to inhibit melanin synthesis. Nine phenolic compounds: $N-feruloylserotonin-5-O-{\beta}-D-glucoside,\;8'-hydroxyarctigenin-4'-O-{\beta}-D-glucoside,\;luteolin-7-O-{\beta}-D-glucoside$, N-(p-coumaroyl)serotonin, N-feruloylserotonin, 8'-hydroxy arctigenin (HAG), luteolin (LT), $acacetin-7-O-{\beta}-D-glucuronide$ (ATG) and acacetin (AT), were quantified by HPLC in safflower (Carthamus tinctorius L.) seeds during growth and processing. During growth, levels of the nine phenolic compounds in the seeds increased progressively with increasing growth stages, reached a maximum on July 30 (42nd day after flowering), and then remained relatively constant. During the roasting process, levels of phenolic compounds, except HAG, LT and AT, generally decreased with increased roasting temperature and time, whereas those of HAG, LT and AT increased progressively with increased roasting temperature and time. During the steaming process, levels of other phenolic compounds except HAG and AT generally tended to increase with increased steaming time, whereas those of HAG and AT were scarcely changed. During the microwave treatment, quantitative changes of phenolic compounds were similar to the roasting process, although there were some differences in levels of phenolic compounds between two heat treatments. These results suggest that the steamed safflower seeds after harvesting on late July may be useful as potential dietary supplement source of phenolic compounds for prevention of several pathological disorders, such as atherosclerosis and osteoporosis and aging.