• 한국패류학회지
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• 제21권1호
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• pp.41-46
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• 2005

A series of radiotracer studies were conducted to evaluate the influence of water temperature and/or body size on the clearance rates and uptake rates of Cd, Se and Zn in the Asiatic clam, Corbicula fluminea, Asian clam Potamocorbula amurensis and Balthic clam, Macoma balthica. Uptake rates of Cd, Se and Zn were estimated simultaneously with clearance rate of clams under 3 different water temperature conditions (5, 13 and $21^{\circ}C$). The weight specific clearance and metal uptake rates of P. amurensiswere increased with temperature, however, no consistent temperature effect was observed for the other clams. The variation of uptake rates of Cd, Se and Zn along with temperature or body size in each clam species was well associated with clearance rates. The inter-species as well as the intra-species difference of metal uptake rates could be well explained by the variation of clearance rates of clam individuals.

• 환경생물
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• 제22권3호
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• pp.438-445
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• 2004

캘리포오니아 홍합(Mytilus californianus)의 용존 Cd, Se, Zn의 흡수율에 대한 개체 크기와 수온의 영향을 평가하기 위하여 방사성 동위원소를 이용한 실험을 수행하였다. 세 개의 크기 구배(0.07, 0.24 and 0.73g; 육질부 건중량)를 갖는 홍합의 용존 금속 흡수율과 여수율은 동시에 4개의 온도 구배(3, 8, 13 and $21^\circ{C})$에서 측정되었다. 세 원소의 흡수율은 개체 크기가 증가함에 따라 유의하게 감소한 반면, 수온이 증가함에 따라 유의한 증가를 보였다. 홍합의 여수율은 전반적으로 용존 금속의 흡수율과 뚜렷한 상관관계를 보였는데, 이는 여과식자인 홍합이 용존 금속을 흡수하는 과정에 있어서 해수 여과 능력의 기능적인 중요성을 보여주는 결과이다.

• 미생물학회지
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• 제16권1호
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• pp.21-29
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• 1978

In the fed-batch fermentation of penicillin specific uptake rates of carbon source and ammonia nitrogen, and specific production rate of penicillin as the most important process variables were evaluated over the fermentation course and their effects on the productivity studied. As the results, glucose and lactose each as a major carbon source showed the following values, respectively ; the specific uptake rates of 47-93 mg hexose per gm-DCW per he and 37-44 mg hexose per gm-DCW per hr, the specific uptake rates of 4.6-6.8 mg $NH_3-N$ per gm-DCW per hr, and 1.2 mg $NH_3-N$ per gm-DCW per he and the specific production rates of 32-42 arbitrary unit per gm-DCW per hr and 46-50 arbitrary unit per gm-DCW per hr. The productivity of penicillin could be improved by controlling the feed rates of glucose and ammonia nitrogen to meet the uptake rates.

• 한국작물학회지
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• 제47권2호
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• pp.108-115
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• 2002

The effects of long-term fertilization on soil properties and nutrient availability are not well documented for cassava cultivation in Vietnam. In 1990, a field research plots were established with 12 treatments to test the effect of different rates of nitrogen (N), phosphorus (P) and potassium (K) on soil properties in Acrisols at Thai Nguyen University in Northern Vietnam. In 1999, composite soil samples (0 to 20cm depth) were collected from eight selected plots for measurements of nutrient supply rates by ion exchange membrane probes and for growing corn and canola in a growth chamber with and without added lime. Generally, long-term nitrogen (N) fertilization increased available N supply rates but decreased available potassium (K) and magnesium (Mg). Long-term phosphorus(P) applications increased canola N, calcium (Ca) and Mg uptake. Canola P uptake increased with increased P rates only when lime was added. Long-term K applications increased canola N, K, Ca, Mg uptake but only significantly increased corn N uptake. Liming significantly increased uptake of N, P, K, Ca, Mg and S for both corn and canola. However, N $H_{4-}$N, K and Mg soil supply rates were reduced when lime was added, due to competition between Ca from the added lime and other nutrients.

• Journal of Radiation Protection and Research
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• 제32권2호
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• pp.45-50
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• 2007

본 연구는 한국인 특성에 대해 보다 신뢰할 수 있는 방사성핵종의 체내 흡수선량 평가를 위한 일환으로 $^{131}I$을 선정하여 체내 각 장기별 잔류율 및 소변 일일배설률을 측정하였다. 실험방법은 성인남성 28명을 대상으로 $^{131}I$을 경구 투여한 후, 시간대별(2, 4, 6, 24시간) 갑상선, 간, 위, 소장, 신장, 소변의 방사능을 측정하고 이를 이용하여 각 장기별 잔류율 및 소변 일일배설률을 산출하였다. 그 결과, $^{131}I$ 투여 24시간 후 갑상선이 평균 19.70%의 잔류율과 71.12%의 소변 일일배설률을 나타냈으며, 갑상선을 제외한 각 장기는 투여 2시간 후 최고 잔류율 및 최고 소변 일일배설률을 보이나, 이후 감소하는 경향을 보였다. 또한 잔류율이 높은 장기 순서는 갑상선을 제외하고 위, 왼쪽 신장, 간, 소장, 오른쪽 신장으로 나타났다. 본 연구를 통해 산출된 방사성옥소의 섭취 24시간 후 갑상선 잔류율 변화는 기존 30%로 보고된 ICRP-54/67 및 25% 잔류율로 보고된 ICRP-78의 자료와 차이를 나타냈다. 한국인의 특성에 맞는 체내 흡수선량 평가의 올바른 접근과 그에 따른 기초 자료의 확보는 향후 원자력 발전소의 작업 종사자 내부피폭 및 임상에서 발생 가능한 체내 피폭의 정량적 평가에 도움을 줄 수 있을 것으로 판단된다.

• Applied Biological Chemistry
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• 제33권3호
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• pp.261-263
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• 1990

The water uptake rates of thirty-four japonica and twenty-five j x indica brown rices at $100^{\circ}C$ were analyzed. The water uptake rates had no correlation with size or volume of brown rice kernel. The regression equations for water uptake rates between brown rice at $100^{\circ}C$(Y) and milled rice at $23^{\circ}C(X)$ for japonica and j x indica varieties were Y = 1.12X-0.34(r = 0.976, p<0.001) and Y = 1.16X-0.54(r = 0.990, p<0.001), respectively (Received August 13, 1990 and accepted September 20,1990).

• Journal of the korean society of oceanography
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• 제32권4호
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• pp.191-201
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• 1997

To test the roles of NO$_3^-$ concentration and light as controlling factors of NO$_3^-$ uptake in the NO$_3^-$-low and -high environments and to assess the significance of night-time nitrogen (N) uptake in estimating the daily N uptake rate, 2 diel studies of N uptake were conducted in NO$_3^-$-low (the eastern part of the Yellow Sea) and NO$_3^-$-high (the marginal ice zone of the northwestern Weddell Sea) environments on June 14 to 15, 1996 and January 15 to 16, 1995, respectively. Ourobservations confirmed that NO$_3\;^-$ uptake by phytoplankton is mainly determined by ambient NO$_3^-$ concentration in NO$_3^-$-low environment and by light in NO$_3^-$-high environment, respectively, Our results suggest the need for diel studies to accurately estimate the daily N uptake rates and thus new and regenerated production because the daily rates calculated without considering the night-time N uptake would be significantly underestimated (up to 41%), particularly in the NO$_3^-$-low environment.

• 대한핵의학회지
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• 제27권2호
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• pp.248-255
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• 1993

To Assessment of the quantified renal uptake rates in every $^{99m}Tc$-DMSA scan tests of patients is actually difficult because of time consumption and complicated calculations required to measure the correct dose of the infused radionulide and radiation decay, the adjustment for the depth of kidney and the subtraction of background count. We've formulated two regression models for the quantified renal uptake rates[I] from the simple renal uptake rates[H] with a square shaped ROI (Region-Of-Interest) in 25 cases (Group 1) and with a kidney shaped ROI in 37 cases (Group 2), respectively. The regression model for the Group 1 was $[I]_1$=0.885 $[H]_1$-4.575 (P<0.005), and for the Group 2 was $[I]_2$=0.591 $[H]_2$-2.105 (p<0.005). The formal charts were clinically convenient to evaluate the individual renal functions in patients with $^{99m}Tc$-DMSA renal scan.

• The Korean Journal of Physiology
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• 제4권1호
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• pp.1-11
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• 1970

Studies on the analysis of walking were performed on 33 male subjects. A prescription of physical exercise (walking at a speed of greater than 6 km/hr for more than one hour daily) for the promotion of individual health is presented on the basis of walking analysis. Presumptions were made that adequate physical exercise does promote health and is beneficial for the healthy life and increases the life span. These presumptions were derived from the numerous experimental literatures. The literatures support indirectly the presumptions. The following results were obtained and prescription of physical exercise is presented. 1. Oxygen uptake in a walking on a treadmill at a speed of 4 km/hr was only 3 times of the resting oxygen uptake. This kind of moderate exercise did not stimulate the cardiopulmonary system adequately. Heart rate at a 4 km/hr walking was 101 beats/min in boys of less than 20 years old and 83 beats/min in adults. Oxygen uptake at a 6 km/hr walking exceeded 4 times of the resting oxygen uptake. It was interpreted that walking at 6 km/hr stimulated the cardiopulmonary system for the promotion of health. Heart rate at this speed was greater than 110 beats/min in boys and greater than 100 beats/min in adults. 2. Heart rates in a walking of 10 km/hr were 172 beats/min in boys, and 143 beats/min in adults, respectively. Maximal heart rates were 185 beats/min in boys, 180 in office clerks, and 168 beats/min in construction site laboreres. 3. The correlation between heart rate and oxygen uptake was high, namely, r>0.95. Subsequently heart rate could be used as a measure of degree of intensity of physical exercise instead of the cumbersome oxygen uptake measurement. 4. The prescription of physical exercise for the promotion of health is: Daily walking for more than one hour at a speed of greater than 6 km/hr. Bodily functions in this daily walking are in boys (body weight, 50 kg): heart rates of 110 beats/min; breathing frequency, 28/min; oxygen uptake, greater than 4 times of the resting uptake; pulmonary ventilation, 351/min; stride, 124 strides/min; cumulative number of strides for one hour, 7,440 strides, and energy expenditure of more than 300 kcal. In adults (body weight, 60 kg) the bodily functions are: heart rates of 100 beats/min, breathing frequency, 28/min; oxygen uptake, greater than 4 times of the resting uptake; Pulmonary ventilation, 301/min; stride, 127 strides/min; cumulative number of strides for one hour, 7,670 strides, and energy expenditure of more than 300 kcal.

• 한국패류학회지
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• 제21권1호
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• pp.47-56
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• 2005

A series of radiotracer experiments were employed to quantitatively compare the biokinetics of uptake from the dissolved phase (influx rates), uptake from the various types of food source (assimilation efficiency), and loss (efflux) of Ag between Potamocorbula amurensis and Macoma balthica. Simultaneously, influx rates of dissolved Cd in both clams were determined to compare with those of Ag. Effects of salinity on influx rates were evaluated in these 2 euryhaline species, as were effects of clam size. Influx rate of Ag and Cd (${\mu}g g^{-1}$ [dry wt.] $d^{-1}$) increased linearly with metal concentrations. Influx rates of Ag in both clams were 3 to 4 times those of Cd. Absolute influx rates of the 2 metals were 4 to 5 times greater in P. amurensis than M. balthica, probably because of differences in biological attributes (i.e. clearance rate or gill surface area). As salinity was reduced from 20 to 2.5 psu, the influx rate of Cd in P. amurensis increased 4-fold and that of Ag increased 6-fold, consistent with expected changes in speciation. Weight-specific metal influx rates (${\mu}g g^{-1}$ [dry wt.] $d^{-1}$) were negatively correlated with the tissue dry weight of the clams, but most rate constants determining physiological turnover of assimilated metals were not affected by clam size.