Mathematically modeling photosynthesis helps to interpret gas exchange in a plant and estimate the photosynthetic rate as affected by environmental factors. Notably, the photosynthetic rate varies among leaf vertical positions within a single plant. The objective of this study was to measure the distinct photosynthetic rate of lily (Lilium Oriental Hybrid ‘Casa Blanca’) at the upper, medium, and basal leaf positions. Subsequently, the FvCB (Farquhar-von Caemmerer-Berry) photosynthesis model was employed to determine the parameters of the model and compared it with a rectangular hyperbola photosynthesis model. The photosynthetic rates were measured at different intracellular CO2 concentrations () and photosynthetic photon flux density (PPFD) levels. SPAD values significantly decreased with lowered leaf position. The photosynthetic rates at the medium and basal leaves were lower compared with the upper leaves. FvCB model parameters,  and   , showed no significant difference between the medium and basal leaves. Estimated photosynthetic rates from derived parameters by the FvCB model demonstrated over 0.86 of R2 compared with measured data. The rectangular hyperbola model tended to overestimate or underestimate photosynthetic rates at high  with high PPFD levels or low  with high PPFD levels, respectively, at each leaf position. These results indicated that the parameters of the FvCB model with different leaf positions can be used to estimate the photosynthetic rate of lily.

Salinity stress is a major threat to plant growth and development, affecting crop yield and quality. This study investigated the effects of different salinity levels on photosynthetic responses and bulb growth of Lilium LA hybrid “‘Serrada’.” Plants were irrigated with 1 L of 0, 200, and 400 mM NaCl solutions every two weeks for 14 weeks in a greenhouse. At the end of the cultivation period, the substrate pH decreased, and electrical conductivity increased with increasing salinity. Regardless of salinity levels, the days to flowering and number of flowers were similar among treatments. In contrast, the flower width, plant height, number of leaves, and leaf area decreased with increasing NaCl concentrations. Although there were no differences in the photosystem II (PSII) operating efficiency and maximum quantum yield of PSII, net CO2 assimilation rates (An) and stomatal conductance (gs) were significantly reduced at 200 and 400 mM NaCl solutions compared to the control. At 400 mM NaCl solution, bulb diameter and weight significantly decreased at the end of the experiment. These results suggest that bulb growth inhibition could be attributed to limiting photosynthetic rate and stem growth. This finding suggests that salinity mitigation is necessary to maintain plant growth and photosynthetic capacity in lily cultivation on salt-affected soils.

According to IAEA PRIS, there is no record of dismantling commercial heavy water reactors among 57 heavy water reactors around the world. In Canada, which has the largest number of heavy water reactors, three of the 22 commercial heavy water reactors with more than 500 MW are permanently suspended, Gentilly unit 2 (2012), Pickering unit 2 (2007), and Pickering unit 3 (2008), all of which chose a delayed decommissioning strategy. On the other hand, Wolsong unit 1, which will be the world’s first heavy water reactor to be dismantled commercially, will be immediately carried out as a decommissioning strategy. KHNP has established various cooperation systems with advanced companies and international organizations related to overseas NPP decommission and is actively exchanging technologies. Among them, the most important focus is on research cooperation related to COG (CANDU owners Group). The first case is a joint study on Conceptual Calandria Segmentation. Four areas of process, waste management, ALARA, and cost for decommissioning reactors to be submitted to Canadian regulators for approval of Pickering and Gentilly-2’s preliminary decommissioning plan have been evaluated, and research on Wolsong unit 1 is currently underway. The second case is Decommissioning and long-term waste management R&D. Although the technical maturity is low, it studies the common interests of member companies in the decommissioning of heavy water reactor power generation companies and long-term waste management. Robotics for dismantling high-radiation structures, C- 14, H-3 measurement and removal methods, and concrete decontamination technology, which are characterized by heavy water, are being actively studied. KHNP is strengthening international cooperation with COG to prepare for the successful decommissioning of Wolsong unit 1. Based on previous studies by Pickering and Gentilly-2, an evaluation of the decommissioning of Wolsong unit 1 reactor is being conducted. In addition, it is preparing for decommissioning through experience analysis of the pressure tube replacement project.

Non-destructive estimation of leaf area is a more efficient and convenient method than leaf excision. Thus, several models predicting leaf area have been developed for various horticultural crops. However, there are limited studies on estimating the leaf area of strawberry plants. In this study, we predicted the leaf areas via nonlinear regression analysis using the leaf lengths and widths of three-compound leaves in five domestic strawberry cultivars (‘Arihyang’, ‘Jukhyang’, ‘Keumsil’, ‘Maehyang’, and ‘Seollhyang’). The coefficient of determination (R2) between the actual and estimated leaf areas varied from 0.923 to 0.973. The R2 value varied for each cultivar; thus, leaf area estimation models must be developed for each cultivar. The leaf areas of the three cultivars ‘Jukhyang’, ‘Seolhyang’, and ‘Maehyang’ could be non-destructively predicted using the model developed in this study, as they had R2 values over 0.96. The cultivars ‘Arihyang’ and ‘Geumsil’ had slightly low R2 values, 0.938 and 0.923, respectively. The leaf area estimation model for each cultivar was coded in Python and is provided in this manuscript. The estimation models developed in this study could be used extensively in other strawberry-related studies.

Colorectal cancer is one of the most common types of cancer in men and women who consume a Western diet. We investigated the inhibitory effect of selenium (sodium selenite, Na2SeO3) and selenium nanoparticles (nano-Se) on experimental colon carcinogenesis in ICR mice. After a 1-week acclimation, 6-week-old mice received three intraperitoneal (i.p.) injections (experimental week 0-2) of azoxymethane (AOM, 10 mg/kg body weight, b.w.), followed by 2% dextran sodium sulfate (DSS)-containing drinking water for the next 1 week. The three groups (10 mice/group) were orally administered either distilled water (control), selenium (1.7 ppm), or nano-Se (1.7 ppm) daily for 8 weeks. The numbers of aberrant crypt foci (ACF), aberrant crypt (AC), and tumorous lesions were measured in colonic mucosa. Se and nano-Se treatments significantly decreased the number of ACF, AC, and tumorous lesions compared with the control. However, there was no significant difference between the selenium and nano-Se groups. The glutathione peroxidase (GSH-Px) activity in the liver and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in serum, were high in the selenium and nano-Se groups, while thiobarbituric acid reactive substance (TBARS) level was low in both Se and nano-Se groups when compared with that in the control group. These findings indicate that selenium and nano-Se showed similar protective effects against colon carcinogenesis by inhibiting the development of ACF and tumorous lesions in mice.

Iron-overload can cause harmful effects such as cancer and aging via promoting the production of free radicals. The effect of orally administered nano-Fe overload with ascorbic acid on colon carcinogenesis was investigated in male ICR mice. After a 1-week acclimation, 5-week-old mice received three intraperitoneal injections (experimental week 0-2) of azoxymethane (AOM, 10 mg/kg body weight) weekly, followed by 2% dextran sodium sulfate (DSS) in drinking water for the next 1 week to induce aberrant crypt foci (ACF). Animals were divided into four groups; carboxymethylcellulose (CMC) alone (control), CMC + ascorbic acid (AA), CMC + nano-Fe (NFe), and CMC + NFe + AA groups. Animals were fed an AIN-76A purified rodent diet and daily administrated oral doses of 450 ppm each of nano-Fe and AA combination for 6 weeks. The colonic mucosa was stained with 0.5% methylene blue, and then the ACF and polyps were counted. Lipid peroxidation in the serum and liver was evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Iron concentration in the liver was measured using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Iron concentration in the liver of the NFe-overloaded groups was higher than that of the control (p<0.05). AA treatment increased the iron concentration in the liver. The number of ACF was not significantly different among all the groups. The number of polyps in all the NFe-treated groups was slightly higher than that in the control group and AA only-treated group. The serum TBARS was not significantly different among all the groups, but that in the liver was higher in all the NFe-treated groups than it was in the control group (p<0.05). These results indicate that the additional NFe treatment did not affect the experimental colon carcinogenesis in mice regardless of the presence of ascorbic acid.

Iron is an essential trace element for normal functions of the body. Restriction of iron availability directly limits erythropoiesis. The objective of this experiment was to compare the bioavailability of iron nanoparticles (Fe-NPs) with iron-microparticles (Fe-MPs) in anemic mice. There were four experimental groups, including the normal control group, iron-deficiency anemia (IDA) group, Fe-NPs group, and Fe-MPs group. Animals in the normal group fed on an adequate iron-containing diet (45 ppm Fe). Meanwhile, animals in the other three groups fed on a low Fe diet (4.5 ppm Fe) for seven weeks. Double deionized water was supplied as drinking water ad libitum. After feeding for three weeks with the low Fe diet, animals in the Fe-NPs and Fe-MPs groups received oral administration of Fe-NPs or Fe-MPs at a daily dose of 40 mg/kg for four weeks. The IDA group showed markedly decreased red blood cell (RBC) count, hematocrit (Hct), and hemoglobin (Hb) values compared with the normal group throughout the experimental periods. Treatments with Fe-NPs or Fe-MPs for four weeks resulted in restoration of the decreased RBC count and hematological values similar to normal values. The Fe-NPs group showed faster restoration in values than Fe-MPs with passage of time. The iron contents of the upper small intestine in the Fe-NPs and Fe-MPs groups were higher than in the normal group at weeks 2 and 4. Treatment with Fe-NPs and Fe-MPs resulted in a significant increase in hepatic iron contents and lipid peroxidation, compared with the IDA group with passage of time. The iron contents in liver and ferritin deposits in spleen were identified in the Fe-NPs and Fe-MPs groups, similar to the normal group. These results indicate that oral administration of both Fe-NPs and Fe-MPs can result in recovery from anemia and Fe-NPs is more absorbable and available in the body than Fe-MPs.

DME 제조공정에서 발생하는 혼합가스 중 CO2를 제거하기 위해서 H2 투과도보다 CO2투과도가 우수한 고무상 고분자를 분리소재로 선정하여 복합막을 제조하고 CO2/H2의 분리성능을 검증하여 보았다. 지지체 중공사막 소재로 PEI를 이용하여 지지체 중공사막을 제조하였으며, 제조된 지지체 중공사막의 기체투과도를 각 가스별로 측정하여 PDMS의 경우는 CO2 투과도 300 GPU 이상, CO2/H2의 선택도가 4.3 이상, PEBAX를 사용한 경우 CO2 투과도 120 GPU 이상 CO2/H2의 선택도가 5 이상인 복합 중공사를 제조하였다.

Both iron-deficient and zinc-sufficient diets have been known to be associated with a decreased risk of colon cancer. We investigated that effect of dietary zinc on the formation of colonic aberrant crypt foci (ACF) induced by azoxymethane (AOM) followed by dextran sodium sulfate in iron-deficient mice. Five-week old ICR mice were acclimated for 1 week and fed on iron-deficient diet (4.50 ppm iron) with three different zinc levels (0.01, 0.1, and 1.0 ppm) for 12 weeks. The total number of aberrant crypt (AC) and ACF was measured in the colonic mucosa after methylene blue staining. The total ACF numbers of low Zn (LZn), medium Zn (MZn) and high Zn (HZn) diet groups were 10.00 ± 2.67, 8.78 ± 3.12, and 7.96 ± 2.44, respectively and there were no significant differences among the groups. However, the total AC numbers of HZn (27.07 ± 3.88) and MZn (26.39 ± 5.59) diet groups were significantly low compared to LZn (22.57 ± 5.09) diet group (p<0.01). Cytosolic SOD activity was the highest in LZn diet group. But thiobarbituric acid-reactive substances level in liver was also the highest in LZn diet group compared to other groups. There is no difference in cell proliferation in mucous membrane among the groups, while apoptotic positive cells were increased in the HZn diet group. The high zinc diet exhibited decreased β-catenin-stained areas on the mucous membrane of colon compared to the LZn or MZn diet group. These findings indicate that dietary zinc might exert a modulating effect on development of ACF/AC in the mice with iron-deficient status.