• Environmental Analysis Health and Toxicology
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• v.30
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• pp.1.1-1.8
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• 2015

Objectives In this study, the effect of tube length and outer diameter (OD) size of hydroxylated-multi walled carbon nanotubes (OH-MWCNTs) on their uptake and toxicity was investigated in the nematode Caenorhabditis elegans using a functional mutant analysis. Methods The physicochemical properties of three different OH-MWCNTs were characterized. Uptake and toxicity were subsequently investigated on C. elegans exposed to MWCNTs with different ODs and tube lengths. Results The results of mutant analysis suggest that ingestion is the main route of MWCNTs uptake. We found that OH-MWCNTs with smaller ODs were more toxic than those with larger ODs, and OH-MWCNTs with shorter tube lengths were more toxic than longer counterparts to C. elegans. Conclusions Overall the results suggest the aspect ratio affects the toxicity of MWCNTs in C. elegans. Further thorough study on the relationship between physicochemical properties and toxicity needs to be conducted for more comprehensive understanding of the uptake and toxicity of MWCNTs.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.11-18
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• 1994

We have studied the iron uptake by the purified brush-border membrane vesicles (BBMVs) to determine the effect of fructose on the absorption of iron. BBMVs were prepared by the modified calcium precipitation method, The degree of purification was routinely assessed by the marker enzyme, alkaline phosphatase, and the functional integrity was tested by $D-[1-^3H]glucose$ uptake. The appearance of membrane vesicles was shown by transmission electron microscopy (TEM). The uptakes of complexes of labeled iron $[^{59}Fe]$ with fructose and ascorbate were measured with a rapid filtration technique, The uptake rate and pattern of the two iron-complexes, Fe(III)-fructose and Fe(III)-ascorbate, were also observed. A typical overshooting uptake of D-glucose was observed with peak value of $2{\sim}3$ times higher concentration than that at equilibrium. This result was similar to other studies with BBMVs. TEM showed that the size of BBMVs was uniform and we can hardly find any contaminants, Fe(III)-fructose has the higher value of $V_{max}$ and the lower value of Km than those of Fe(III)-ascorbate, respectively. It may be concluded that D-fructose is more effective in promoting the iron absorption than ascorbate.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.59-71
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• 1968

The uptake of phenolsulfonphthalein (PSP) and of paraaminohippuric acid (PAH) by cortical slices of the rabbit kidney was investigated while varying the composition of medium. The overall uptake of these substances displayed typical active transport characteristics and was significantly enhanced in presence of acetate. When the phosphate buffer was used the optimal pH was 7.4 for both substances. However, when the tris-buffer was used the optimal pH was 7.4 for PSP and 8.3 for PAH. Removal of $Na^+$ from the medium resulted in a significant reduction in the uptake. Similar results, though lesser in magnitude, were obtained when either $K^+\;or\;Ca^{++}$ was removed from the medium. However, there was no additive effect when $K^+\;and/or\;Ca^{++}$ were additionally removed from the $Na^+-free$ medium. The presence of ${NH_4}^+$ greatly reduced while $Li^+\;and\;Mg^{++}$ moderately reduced the uptake of both substances. However, choline had no effect. In substrate-leached slices, acetate greatly enhance the uptake of organic acids; but this action was not demonstrable in absence of $Na^+,\;K^+\;or\;Ca^{++}$.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.98-103
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• 2011

The System of Rice Intensification (SRI) is a new concept of increasing the yield of rice produced in farming. Therefore, we investigated the impacts of planting density on nutrient uptake as affected by SRI under no-till cropping system. The field was prepared as a randomized complete block design with three treatments: $10{\times}10$ cm, $20{\times}20$ cm and $30{\times}30$ cm planting densities. The root dry mass was significantly increased in the wider planting densities (p<0.05%). The highest grain yield was obtained in $20{\times}20$ cm planting density plot (p<0.05%) due to higher plant density per unit area and spikelets number per panicle. The total uptake amounts by rice plant were significantly higher in $20{\times}$20 cm planting density plot as 94.8 kg $ha^{-1}$ for T-N and 29.9 kg $ha^{-1}$ for P than other planting densities plots, but K and Mg uptake were significantly higher in $10{\times}10$ cm planting density plot (p<0.05%). In this study, our findings suggest that SRI should be considered as a new practice for the rice productivity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2899-2902
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• 2015

Background: Cervical cancer is one of the most common cancers among women worldwide, and in Thailand is the second most common cancer among women. In 2008, a national cervical cancer screening programme was implemented in Thailand, but coverage remains relatively low. Objectives: The purpose of the study was to investigate whether cervical cancer screening uptake is associated with the area of residency in Thailand. Materials and Methods: A case-control study was carried out in women aged 30 to 60 year-old, who live in Sikhiu district, Nakhon Ratchasima province, Thailand. Structured-questionnaires were used to interview 226 women (cases) who had attended cervical cancer screening in the last five years and 226 women (controls) who had not. Multiple logistic regression was used to investigate the association between the area of residency and cervical cancer screening uptake. Results: After controlling for parity, marital status and duration of hormonal contraceptive use, an association between the area of residence and cervical cancer screening uptake could not demonstrated ($OR_{adj}$ 1.27, 95%CI: 0.79, 2.04). Conclusions: We found no evidence to suggest remoteness to health care center led to lower cervical cancer screening uptake.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.61-68
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• 2008

High initial (2 minutes after iv injection) brain-uptake of PET agents is required to deliver the agent to binding sites in brain tissue but, for quantification of the specific binding, relatively rapid washout of free and non-specifically bound PET agents from the brain (30 minutes after injection) also is required. In order to compare the physicochemical properties of the PET agents which are responsible for early brain-uptake and rapid washout, respectively, chemometric analysis on brain-uptake of PET agents was performed via a classical VolSurf approach. According to the PCA and PLS results, high 2-30 min brain-uptake ratio seems to be related to the large hydrophobic regions in the PET agents which are not confined to a particular surface.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.162-165
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• 2003

Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• ALGAE
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• v.17 no.3
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• pp.187-194
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• 2002

A seaweed biofilter/production system of being developed to reduce the environmental impact of marine fish farm effluent in coastal ecosystems as a part of an integrated aquaculture system. Several known seaweed taxa and their cultivars have been considered as candidate biofilter organisms based on their species-specific physiological properties such as nutrient uptake kinetics and their economic value. Porphyra is an excellent cadidate and shows efficient nutrient extraction properties. Rates of ammonium uptake were maintained at around 3 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ at 150 ${\mu}M$ inorganic nitrogen at $10^{\circ}C$. Ulva is another possible biofilter candidate with an uptake rate of 1.9 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ under same conditions. A simple uptake/growth and harvest model was applied to estimate the efficiency of the biofilter/production system. The model was deterministic and used a compartment model structure based on difference equations. The efficiency of Porpyra filter was estimated over 17% of ${NH_4}^+$ removal from the contimuous supply of 100 ${\mu}mole{\cdot}l^{-1}\;{NH_4}^+\;at\;100l{\cdot}sec^{-1}$ flow rate.

• The Korean Journal of Nuclear Medicine
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• v.3 no.2
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• pp.17-22
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• 1969

The differences in the change of the uptake rate of radioactive iodine ($^{131}I$) in the thyroid gland after $Tapazole^{(R)}$ administration before $^{131}I$ treatment were analysed in 137 patients who were diagnosed as diffuse toxic goiter in the Radioisotope Clinic and Laboratory, Seoul National University Hospital since Jan. 1967 to July, 1969. The uptake rate of the therapeutic dose of $^{131}I$ was changed diffusely compared with that of the trace dose in the patients who had no $Tapazole^{(R)}$ administration before $^{131}I$ treatment. In those patients who had $Tapazole^{(R)}$ more than 20 mg/day for more than one week before $^{131}I$ treatment, the uptake rate was decreased significantly. When the patients discontinued the administration of $Tapazole^{(R)}$ 7 days prior to $^{131}I$ treatment, the uptake rate was increased in all cases.