• 대한수학회보
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• 제51권6호
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• pp.1735-1748
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• 2014

In this paper, we investigate the finite order transcendental meromorphic solutions of complex difference equation of Malmquist type $$\prod_{i=1}^{n}f(z+c_i)=R(z,f)$$, where $c_1,{\ldots},c_n{\in}\mathbb{C}{\backslash}\{0\}$, and R(z, f) is an irreducible rational function in f(z) with meromorphic coefficients. We obtain some results on deficiencies of the solutions. Using these results, we prove that the growth order of the finite order solution f(z) is 1, if f(z) has Borel exceptional values $a({\in}\mathbb{C})$ and ${\infty}$. Moreover, we give the forms of f(z).

• International Journal of Control, Automation, and Systems
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• 제3권3호
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• pp.430-443
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• 2005

A general construction algorithm of the Grassmann space parameters in linear systems - so-called, the Plucker matrix, 'L' in m-input, p-output, n-th order static output feedback systems and the Plucker matrix, $'L^{aug}'$ in augmented (m+d)-input, (p+d)-output, (n+d)-th order static output feedback systems - is presented for numerical checking of necessary conditions of complete static and complete minimum d-th order dynamic output feedback pole-assignments, respectively, and also for discernment of deterministic computation condition of their pole-assignable real solutions. Through the construction of L, it is shown that certain generically pole-assignable strictly proper mp > n system is actually none pole-assignable over any (real and complex) output feedbacks, by intrinsic rank deficiency of some submatrix of L. And it is also concretely illustrated that this none pole-assignable mp > n system by static output feedback can be arbitrary pole-assignable system via minimum d-th order dynamic output feedback, which is constructed by deterministic computation under full­rank of some submatrix of $L^{aug}$.

• Clinical and Experimental Pediatrics
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• 제46권9호
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• pp.934-938
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• 2003

저자들은 신생아기에 경련을 보였던 환아에서 소변의 N-acetylaspartic acid의 정량검사를 통해 확진하였으며, 뇌자기공명 소견상 뇌백질의 퇴행성변화를 보였던 Canavan 병 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국물환경학회지
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• 제30권6호
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• pp.665-672
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• 2014

Elemental cellular stoichiometry of natural phytoplankton communities was examined in six large dam reservoirs in the Han River system. Carbon (C) and nitrogen (N) contents of the phytoplankton-dominated seston from Lake Soyang was higher than that from other lakes. Phosphorus (P) content showed slight variations among six lakes in the range of $0.04{\sim}0.18{\mu}mol$ P mg $DW^{-1}$. The phosphorus concentrations of lake water showed obvious positive relationship with P and C contents of the phytoplankton-dominated seston. In all six lakes, N:P ratios and C:P ratios in the phytoplankton-dominated seston were more than 23 and 133 respectively, indicating the phytoplankton communities in six lakes have been exposed in phosphorus limited condition. The relative abundance of diatoms showed significant negative correlation with C, N, P contents of the phytoplankton-dominated seston and that of cyanobacteria showed significant positive correlation. Elemental stoichiometry of diatoms-dominated seston showed distinctive less content than that of cyanobacteria-dominated seston. The cellular N:P ratios of diatoms- and cyanobacteria-dominated seston indicate that both main classes of phytoplankton in six lakes are in phosphorus deficiency. Elemental stoichiometry of the phytoplankton-dominated seston in this study could be used for the further ecological stoichiometric studies in six lakes.

• 운동영양학회지
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• 제24권4호
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• pp.24-27
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• 2020

[Purpose] Dehydroepiandrosterone (DHEA) administration reportedly recovers osteoporosis, a bone disorder associated with bone deficiency in postmenopausal women. However, the physiological mechanism of DHEA in osteoporosis remains elusive, especially in terms of intestinal calcium absorption. Therefore, we investigated the effect of DHEA administration on calcium absorption in ovariectomized (OVX) female rats using an estrogen receptor antagonist. [Methods] Female Sprague-Dawley rats (n=23, 6 weeks old) were randomized into three groups: OVX control group (OC, n=7), OVX with DHEA treatment group (OD, n=8), and OVX with DHEA inhibitor group (ODI, n=8) for 8 weeks. [Results] Intestinal calcium accumulation, as well as the rate of absorption, demonstrated no significant differences during the experimental period among investigated groups. The bone mineral density (BMD) of the tibia at the proximal metaphysis was higher in the OD group than that in the OC group (p<0.05); however, BMD of the ODI group showed no significant difference from investigated groups. Furthermore, the BMD of the tibia at the diaphysis did not significantly differ among these groups. [Conclusion] We revealed that DHEA administration does not involve intestinal Ca absorption, although this treatment improves BMD levels in OVX rats. These observations indicate that the effect of DHEA on the bone in postmenopausal women is solely due to its influence on bone metabolism and not intestinal calcium absorption.

• KSBB Journal
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• 제10권4호
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• pp.349-356
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• 1995

하수처리장의 활생오니를 분리원으로 하여 수십종의 PHA 생산균을 분리하였다. 일반적으로 hy­d droxyvalerate monomer unit의 전구물질로 알려져 있지않은 glucose로부터 비교적 많은 PHA를 생산 하는 균주를 공시균으로 선정하여 형태학척, 배양적, 생리학적 제 특성을 검토한 결과 Pseudomonas 속으 로 통정되었다. 균체 생육을 위한 최적 배양온도 벚 배양 pH는 각각 $37^{\circ}C$와 7.0이었으며, 최적 탄소원 으로셔 glucose 1 %, 최적 질소원으로서 $(NH_4)_2SO_4$ 0.2%, K1HPO. 0.3%, $KH_2PO_4$ 0.45% 였다. 최적 P PHA 생산조건을 조사하기 위하여 2단계 배양법을 이용하였다 PHA 생산은 배지성분중 $NH_4, O_4$, Mg가 결핍되 였을 때 향상되었고, 그중 $NH_4$, 의 결핍시 PHA 축적률과 HV monomer의 함량이 가장 높았다. C/N molar ratio 95.2에서 PHA 축적률이 가장 높았다. 공시균주 Pseudomonas sp. HJ는 alkane, alkanoic acid, alcohol을 탄소원으로 하여 P PHB/HV를 생산하였다. PHA의 생산량과 HV monomer의 함량은 이용된 기질에 따라 다양하였으며, 특히 hexadecane와 propiOnate를 탄소원으로 하였을 때 PHA중의 HV monomer의 함량이 49~74mol %로 매우 높았다. IH-NMR로셔 공시균으로 부터 분리정제된 PHA의 조성을 분석한 결과 PHB/ H HV copolymer임을 알 수 였였다

• 한국환경농학회지
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• 제32권2호
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• pp.102-107
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• 2013

BACKGROUND: Pithy pear fruit are not distinguished externally from sound fruit and thus often cause unexpected economic losses. To find out the cause of pithiness, the pithiness incidence and characteristics of Japanese pear (Pyrus pyrifolia cv. Niitaka) fruit picked from a spot frequently produced pithy fruit in an orchard were compared with those of fruit picked from another spot produced sound fruit every year. And the soil chemical properties of the two spots and mineral contents in fruit, shoots, and leaves of Japanese pear trees cultivated in the two spots were also examined. METHODS AND RESULTS: The pithiness incidence was 0, 8.8, and 11.3% at 7 days before and 0 and 7 days after optimal harvest date, respectively, in the spot frequently produced pithy fruit. Flesh firmness was significantly lower in pithy fruit than in sound fruit, while soluble solids content was slightly higher in pithy fruit than in sound fruit. Unlike other mineral contents, Ca content was significantly lower in pithy fruit than in sound fruit. These results indicate that Ca deficiency in fruit is closely associated with decrease in flesh firmness and thus pithiness development. Ca content in soil of the spot frequently produced pithy fruit was also significantly lower than that in soil of the spot produced sound fruit. However, shoots or leaves did not exhibit significant difference in Ca and/or other mineral contents between the two spots, indicating that Ca deficiency in fruit is dependent on the translocation of Ca within a plant rather than soil Ca status. Although total-N, available $P_2O_5$, K, and Ca contents were significantly lower in soil of the spot frequently produced pithy fruit than in soil of the spot produced sound fruit, Mg and Na contents and pH were not different between the soil conditions. CONCLUSION(S): Fruit maturity and Ca level in fruit are closely related to the incidence of pithiness in 'Niitaka' Japanese pear.

• Journal of Animal Science and Technology
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• 제44권3호
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• pp.279-288
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• 2002

본 연구는 국내 홀스타인 젖소 보증종모우 16두와 후보종모우 93두를 이용하여 선천성 장애 유전자의 검색을 통하여 불량 유전자의 존재 유무를 판별함과 동시에 가축의 선발 및 육종, 개량시 기초자료로 제공하고자 하는데 그 목적이 있으며, 본 연구의 결과를 요약하면 아래와 같다. 공시재료(홀스타인 젖소 보증종모우 16두, 후보 종모우 93두) 109두에 대하여 DUMPS (deficiency of uridine monophophate synthase)의 검색결과 모든 개체에서 DUMPS 유전자를 보유하는 개체는 없는 것으로 판명되었다. 또한 PCR-RFLP(Ava I) 방법에 의해 조기 검색이 가능하게 되었다. 한편, BLAD(bovine leukocyte adhesion deficiency) 검색결과, 보증종모우 16두에서는 검출되지 않았으나, 후보우 93두중 5두에서 BLAD 잠재성 보유개체(carrier)로 판명되었고, 혈통확인을 통하여 BLAD 유전자의 전이 경로를 추정할 수 있었으며, PCR 증폭산물에 대한 제한효소 처리시 HaeⅢ 보다는 TaqⅠ 제한효소를 사용하였을 때 더 효율적으로 판명할 수 있는 것으로 나타났다. Citrullinemia 검색결과 보증종모우 16두 및 후보종모우 93두 모두에서 잠재성 보유개체는 없는 것으로 판명되었으나 citrullinemia에 대한 폭넓고 다양한 조사 및 분석이 이루어져야 할 것으로 사료된다. 본 연구의 결과로 미루어 볼 때 가축의 유전성 질환에 대한 다양하고 폭넓은 연구가 이루어 져야 할 것으로 사료되며, 가축의 선발과 육종, 개량에 있어서 지속적이며 혈통의 철저한 관리를 통한 개량의 방향을 설정하여야 할 것으로 판명되었다.

• Osteoporosis and Sarcopenia
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• 제2권4호
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• pp.228-237
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• 2016

Objective: There has been no prospective study that examined intramuscular injection of high-dose vitamin D in Korean adults. The aim of this study was to assess the efficacy and safety of high-dose vitamin $D_3$ after intramuscular injection in Korean adults with vitamin D deficiency. Method: This study was a 24-week, prospective, multicenter, randomized, double-blind, placebo-controlled trial. A total of 84 subjects ${\geq}19$ and <65 years of age were randomly allocated to either the vitamin $D_3$ or placebo group in a 2:1 ratio. After randomization, a single injection of plain vitamin $D_3$ 200,000 IU or placebo was intramuscularly administered. If serum 25-hydroxyvitamin D (25[OH]D) concentrations were <30 ng/mLon week 12 or thereafter, a repeat injection was administered. Results: After a single intramuscular injection of vitamin $D_3$ to adults with vitamin D deficiency, the proportion of subjects with serum 25(OH)D concentrations ${\geq}30ng/mL$ within 12 weeks was 46.4% in the vitamin $D_3$ group and 3.6% in the placebo group (p<0.0001). The proportion of subjects with serum 25(OH)D concentrations ${\geq}30ng/mL$ within 24 weeks was 73.2% in the vitamin $D_3$ group and 3.6% in the placebo group (p<0.0001). Mean change in serum 25(OH)D concentrations at weeks 12 and 24 after vitamin $D_3$ injection was $12.8{\pm}8.1$ and $21.5{\pm}8.1ng/mL$, respectively, in the vitamin $D_3$ group, with no significant changes in the placebo group. Serum parathyroid hormone concentrations showed a significant decrease in the vitamin $D_3$ group but no change in the placebo group. Conclusion: Intramuscular injection of vitamin $D_3$ 200,000 IU was superior to placebo in terms of its impact on serum 25(OH)D concentrations, and is considered to be safe and effective in Korean adults with vitamin D deficiency.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권1호
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• pp.79-86
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• 2022

Purpose: To determine the effect of zinc deficiency on fecal protein, electrolyte, and short-chain fatty acid levels in both heat-stable (ST) and heat-labile (LT) enterotoxigenic Escherichia coli (ETEC)-induced diarrhea in rats. Methods: Albino rats, weighing 100 to 150 g, were divided into 2 groups, with 15 animals each: non-zinc and zinc-deficient. These two groups were sub-divided into three sub-groups with five rats each: control (saline); LT-ETEC; and ST-ETEC. Sodium phytate (30 mmol/L) was added to the animals' water to induce zinc deficiency, while diarrhea was induced using 5×10⁹ ETEC cells/mL. Fecal protein levels were estimated using the Bradford method, while sodium and potassium levels were determined using atomic absorption spectrophotometry. Short-chain fatty acids were measured using gas chromatography-mass spectrometry. Results: Among the non-zinc and zinc-deficient groups, there were significant increases (p=0.04), (p=0.03) in fecal protein concentrations (mg/mL) in the LT-ETEC- (4.50±0.33), (6.50±0.26) and ST-ETEC- (3.85±0.19), (5.98±0.32) induced groups compared to the control groups (2.60±0.52), (3.50±0.11) respectively. Fecal sodium and potassium levels (mg/L) were significantly (p=0.029) increased in non-zinc-deficient rats induced with LT-ETEC (9.35±0.95, 1.05±0.48), and ST-ETEC (9.96±1.02, 1.21±0.45) compared with the control group (8.07±0.44, 0.47±0.17) but the increase were not statistically significant (p=0.059) in the zinc deficient rat groups. Fecal acetate and propionate levels (mg/g) significantly (p=0.032) increased when induced with LT-ETEC and ST-ETEC in non-zinc and zinc-deficient groups compared with the control groups. Conclusion: Zinc deficiency among rats with ETEC-induced diarrhea elevated fecal protein loss but may not have an effect on fecal sodium, potassium and short-chain fatty acid levels.