• Applied Biological Chemistry
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• 제44권3호
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• pp.185-190
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• 2001

알긴산은 일반적으로 미생물의 고정화에 널리 사용되는 biopolymer이다. 본 연구는 구연산 생산균인 Aspergillus niger를 calcium alginate로 고정화한 beads로 납의 흡착 특성을 조사하였다. A. niger beads는 $CaCl_2$를 사용하여 주사기로 제조하였으며 이 beads를 납제거에 이용하였다. 그 결과는 다음과 같다. 즉, A. niger를 구연산 생성배지에서 1일에서 7일까지 배양한 후 제조한 beads로 납흡착량을 측정한 결과는 3일간 배양된 곰팡이 beads에서 가장 높았다. 발아되지 않은 beads와 3일간 배양된 beads로 시간에 따른 납흡착량을 정량한 결과 30분까지는 그 흡착량이 동일하게 급격히 증가하였으며 그 후 발아되지 않은 beads는 더 이상 흡착이 일어나지 않았으나 3일간 배양된 곰팡이 beads는 시간이 지남에 따라 천천히 계속 흡착하여 1시간 후에는 480 ppm까지 흡착하였다. 납흡착시 최적 pH와 온도는 각각 6과 $35^{\circ}C$로 나타났다. 납용액 50 ml (500 ppm)이 든 250 ml 삼각플라스크에 beads $50{\sim}100$개가 최적이었으며 그 이상에서는 납흡착율이 감소하였다. 중금속에 대한 흡착율은 납> 구리> 카드뮴 순이었으며 0.1 M $CaCl_2$, 0.1 M NaOH 및 0.1 M KOH의 전처리의 효과는 없었으며 0.1 HCI로 곰팡이 bead의 납탈착하여 beads를 재사용이 가능하였다.

• 대한핵의학회지
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• 제10권1호
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• pp.21-34
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• 1976

The diagnosis of iron deficiency rests upon the correct evaluation of body iron stores. Morphological interpretation of blood film and the red cell indices are not reliable and often absent in mild iron deficiency. Serum iron levels and iron-binding capacity are more sensitive indices of iron deficiency, but they are often normal in iron depletion and mild iron deficiency anemia. They are also subject to many variables which may introduce substantial errors and influenced by many pathologic and physiologic states. Examination of the bone marrow aspirate for stainable iron has been regarded as one of the most sensitive and reliable diagnostic method for detecting iron deficiency, but this also has limitations. Thus, there is still need for a more practical, but sensitive and reliable substitute as a screening test of iron deficiency. Pollack et al. (1965) observed that the intestinal absorption of cobalt was raised in iron-deficient rats and Valberg et al. (1969) found that cobalt absorption was elevated in patients with iron deficiency. A direct correlation was demonstrated between the amounts of radioiron and radiocobalt absorbed. Unlike iron, excess cobalt was excreted by the kidney, the percentage of radioactivity in the urine being directly related to the percentage absorbed from the gastrointestinal tract. Recently a test based on the urinary excretion of an oral dose of $^{57}Co$ has been proposed as a method for detecting iron deficiency. To assess the diagnostic value of urinary cobalt excretion test cobaltous chloride labelled with $1{\mu}Ci\;of\;^{58}Co$ was given by mouth and the percentage of the test dose excreted in the urine was measured by a gamma counter. The mean 24 hour urinary cobalt excretion in control subjects with normal iron stores was 6.1% ($1.9{\sim}15.2%$). Cobalt excretion was markedly increased in patients with iron deficiency and excreted more than 29% of the dose. In contrast, patients with anemia due to causes other than iron deficiency excreted less than 27%. Hence, 24 hour urinary cobalt excretion of 27% or less in a patient with anemia suggets that the primary cause of the anemia is not iron deficiency. A value greater than 27% in an anemic subject suggests that the anemia is caused by iron deficiency. The cobalt excretion test is a simple, sensitive and accurate method for the assessment of body iron stores. It may be particularly valuable in the epidemiological studies of iron deficiency and repeated evaluations of the body iron stores.