• Korean Journal of Environmental Agriculture
• /
• v.41 no.3
• /
• pp.191-198
• /
• 2022

BACKGROUND: Plants can be grown using a culture medium without soil using a hydroponic system. Crop production by the hydroponic system is likely to increase as a means of solving various problems in the agricultural sector such as aging of rural population and climate change. Different water sources can be used to prepare the culture medium used in the hydroponic system. Therefore, it is necessary to study the effect of different water sources on crop production by the hydroponic system in order to explore the applicability of various water resources. METHODS AND RESULTS: Lettuce was cultivated by the hydroponic system and three different water sources [tap water (TW), bottled water (BW), and groundwater (GW)] were used to compare the effect of water sources on lettuce growth. The three kinds of waters with a nutrient solution (TW-M, BW-M, GW-M) were also used as the media. After the six-week growth period, the lettuce length and weight, the number of leaves, and the contents of chlorophylls and polyphenols were compared among the different media used. The lettuces did not grow in the waters without the nutrient solution. In the media, the lettuce growth and the contents of chlorophylls were affected by the different water sources used to prepare the media, while the contents of polyphenols were not affected. The absorbed amounts of ions by lettuces, especially Ca and Zn ions, and the dry weight of the harvested lettuces showed a strong positive correlation. CONCLUSION(S): Overall, this study shows that different water sources used for growing lettuce in a hydroponic system can affect lettuce growth. Further studies on the enhancement of crop qualities using different water sources may be required in future studies.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.2
• /
• pp.182-187
• /
• 2013

This study was conducted to examine the effect of calcium extracted from salted anchovy (Engraulis japonicus) on the calcium metabolism of rats. Sprague-Dawley male rats were fed low-calcium diets (0.15%) for 2 weeks after the adjustment period. Rats were divided into five groups and were fed experimental diet for four weeks. Experimental diets were low calcium (LC, 0.15% $CaCO_3$), 0.5% $CaCO_3$ (CC), seaweed calcium (SC), calcium lactate (LC), anchovy calcium (AC). The low-calcium diet group (LC) showed the lowest weight gain and had no differences among the groups with adequate calcium intake. Calcium retention was lowest in the LC group and higher in the CL, SC, AC groups than in SC groups. Serum alkaline phosphatase (ALP) level was highest in LC group, and significantly low in the CC and AC groups (p<0.05). Parathyroid hormone and osteocalcin levels showed no differences among experimental groups. The urine deoxypyridinoline (DPD) level was lower in AC and CC groups compared to the LC group (p<0.05). The dry weight of the femur showed no significant differences among normal calcium groups. The bone mineral density of the femur in AC and CC group were significantly higher than the LC group (p<0.05). From these results, calcium extracted from salted anchovy can be useful as a calcium supplement comparable with calcium carbonate.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.3
• /
• pp.29-37
• /
• 2014

Objectives Osteoporosis is an impending problem in the rapidly aging society. The purpose of this study is to identify the effects of Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) on osteoporosis induced by ovariectomy in rats. Methods 24 rats were randomly assigned to a SHAM group, a control group, and a Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) group (n=8). Ovaries were extracted and for 8 weeks, the rats were given dry feeds and Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) group were given a mixture of dry feeds and Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$). At 8 weeks, their body weight, femur mass, tibia ash per body ratio, overall surface area and thickness of the trabeculae, overall surface area of the osteoblasts, and the number of osteoclasts were measured and levels of albumin, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total-cholesterol, calcium and estradiol were recorded. Results There was no significant difference in the weight of the femur and the tibia ash per body ratio. The Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) group had significantly thicker trabeculae than the control group and showed a minimal increase of overall surface area of the trabeculae. The overall surface area of the osteoblasts and the number of osteoclasts decreased in the Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) group. There were no statistically significant differences in AST, ALT, ALP, total cholesterol, phosphorus, and estradiol levels. On the contrary the Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) group had significantly higher levels of Albumin, triglyceride, and calcium. Conclusions It can be concluded that oral intake of Yoohyangheukho-dan ($R{\check{u}}xi{\bar{a}}ngh{\bar{e}}ih{\check{u}}-d{\bar{a}}n$) prevents the thinning process of the trabeculae. Thus, it may have positive effects on the treatment and prevention of osteoporosis in postmenopausal women.

• Clinical and Experimental Reproductive Medicine
• /
• v.37 no.2
• /
• pp.89-98
• /
• 2010

Sex and its tropic hormones influence the lacrimal system, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, and retinal disease. Dry eye occurs especially frequently during pregnancy, oral contraceptive use, and after menopause, during which androgen levels decrease. Androgen control development, differentiation, and lipid production of sebaceous glands throughout the body, and androgen deficiency also leads to meibomian gland dysfunction and evaporative dry eye. On the other hand, estrogen causes a reduction in size, activity, and lipid production of sebaceous glands. Sex and its tropic hormones also influence the corneal anatomy and disease, and corneal thickening occurred on the second day of the menstrual cycle and around the time of ovulation and appeared to be related to estrogen levels. Fuchs' dystrophy is more commonly seen in postmenopausal women than men and may be linked to hormonal changes that occur with aging. In addition, overexpression of estrogen and progesterone receptors in the conjunctiva of vernal keratoconjunctivitis patients. Serum progesterone levels also may be associated with intraocular pressure especially in pregnant women, and for the women. For women with cataracts, hormone levels were typical of menopause, and there was a significant negative correlation between estradiol and follicular stimulating hormone levels. In addition, serum testosterone levels are associated with the development of diabetic retinopathy. Although the role of sex hormones on the eye is largely unknown, and the results should be interpreted with caution until replicated, the functions of sex hormones in ocular disease remains to be investigated, because they may be involved in structure and function of the ocular components, which are important in the pathogenesis of ocular disease.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.40 no.4
• /
• pp.227-235
• /
• 2020

This study was conducted to investigate the growth characteristics of the shoot and roots and to analyse the morphological characteristics of roots of waterlogging resistant and susceptible maize inbred lines. Six maize inbred lines were treated with waterlogging for 10 days at V3, and the degree of leaf senescence was evaluated for waterlogging resistance. As a result of waterlogging resistance evaluation, KS85 was the most damaged inbred line with 3.33 senescence leaves and 5.54 degree, and KS141 was the least damaged inbred line with 1.33 senescence leaves and 3 degree. At 20 days after treatment, the effect of waterlogging stress on the shoot dry matter accumulation of KS85 and KS141 were decreased by 86.1% and 77.0%, respectively, compared to the control. Similarly, root dry matter accumulation of KS85 and KS141 were decreased by 77.6% and 65.0%. As a result of SEM photographs of the nodal roots of the two maize inbred lines, the thickness of cortex of KS141 was thicker than that of KS85, and the distortion of the cortex was observed in KS85 at 20 days after waterlogging. It was concluded that the thickness of cortex was related to maize waterlogging resistance.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.6
• /
• pp.764-769
• /
• 1999

This study was designed to investigate the effects of sea tangle (Laminaria japonica) extract (Dasi-Ex group: dry base $4.0\%$) and fucoidan-added (Fuco-I, II, III group: fucoidan of $1,0\%,\;2.0\%,\;3.0\%$ added to Dasi-Ex) drinks on the formation of oxygen radicals and scavenger enzyme activities of stressed mice. ICR male mice (20 $\pm$2 g) were fed experimental diets and these drinks instead of water for 18 days including 4 days of sociopsychological stress. Dasi-Ex and Fuco-I, II and III groups resulted in a marked decreases $20\~40\%$ in basal oxygen radical (BOR) formation, and $15\~25\%$ in induced oxygen radical (IOR) formation compared with control group. Hydroxyl radical formations were significantly inhibited about $10\%$ in Dasi-Ex group, while remarkably inhibited $30\~40\%$ in Fuco-I, II and III groups. lipid peroxide (ISO) levels in Dasi-Ex group were not significantly different from those of control group, tut Fuco-I, II and III groups resulted in a significant decreases about $10\%$ in LPO levels compared with control group, Dasi-Ex, Fuco-I, II and III groups resulted in a marked decreases ($31\%,\;36\%,\;39\%$ and $42\%$, respectively) in oxidized protein levels through production of carbonyl group. Significant differences in nitric oxide (NO) levels in Dasi-Ex group were not obtained, but NO levels were slightly inhibited about $7\%$ in Fuco-I and II groups and $20\%$ in Fuco-III group compared with control group. Significant differences in superoxide dismutase (SOD) and catalase (CAT) activities in Dasi-Ex and Fuco-I groups were not obtained, but Fuco-II and III groups resulted in a significant increases $25\~40\%$ in SOD activities, and about $10\%$ in CAT activities compared with control group. These results suggest that the sociopsychological stress and aging process could be effectively inhibited by biological activity of sea tangle and fucoidan components.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.1
• /
• pp.30-39
• /
• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.422-431
• /
• 2019

Severe droughts in spring have occurred frequently in Korea in recent years, exerting a critical impact on corn yield. Therefore, it is necessary to find physiological and/or molecular indicators of the response to drought stress in maize plants. In this study, we investigated the effects of water-deficit stress on two Korean elite F₁ maize hybrids, Ilmichal and Gwangpyeongok, by withholding water for 10 days at tassel initiation. The water deficit drastically reduced the relative leaf water content, leaf number, leaf area, and stem length, leading to dry matter reduction. Moreover, it reduced the SPAD values and stomatal conductance of leaves in drought-stressed plants of both hybrids. Importantly, the number of leaves and SPAD value were non-destructive and easy to investigate in response to water-deficit stress, suggesting that they may be useful indicators for screening drought-tolerant genetic resources. We detected more than 100 spots that were differentially accumulated under drought stress. Of these spots, a total of 21 protein spots (≥1.5-fold) from drought-exposed maize leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Functional annotation using Gene Ontology analysis revealed that most of the identified proteins were involved in carbohydrate metabolism, stress response fatty acid catabolism, photosynthesis, energy metabolism, and transport. The protein expression levels were increased in both Ilmichal and Gwangpyeongok, except for triosephosphate isomerase, fructose-bisphosphate aldolase, and an uncharacterized protein. The lactoylglutathione lyase delta (3,5)-delta (2,4)-dienoyl-CoA isomerase was overexpressed in Gwangpyeongok only. The results obtained from this study suggest that the drought-specific genes may be useful as molecular markers for screening drought-tolerant maize genotypes.

• Korean Journal of Plant Resources
• /
• v.34 no.4
• /
• pp.287-296
• /
• 2021

Recently, the pace of global climate change has tremendously increased, causing extreme damage to crop production. Here, we aimed to examine the growth characteristics and useful components of Angelica gigas under extreme heat stress, providing fundamental data for its efficient cultivation. Plants were exposed to various experimental temperatures (28℃, 34℃, and 40℃), and their growth characteristics and content of useful components were analyzed. At the experimental site, the ambient and soil temperature were 19.38℃ and 21.34℃, ambient and soil humidity were 81.3 % and 0.18 m³/m³, solar radiation was 162.05 W/m². Moreover, the soil was sandy-clay-loam (pH 6.65), with 2.66% organic matter, 868.52 mg/kg soil available phosphate, and 0.14% nitrogen. Values of most growth characteristics, including the survival rate (85%), plant height (38.66cm), and fresh and dry weight (41.3 g and 14.24 g), were the highest at 28℃. Although the highest content of useful components was observed at 34℃ (3.24%), there were no significant differences across temperatures. Growth characteristics varied across temperatures due to detrimental effects of heat stress, such as accelerated tissue aging, reduced photosynthesis, and delay of growth. Similar content of useful components across temperatures may be due to poor accumulation of anabolic products caused by impaired growth at extremely high temperatures.