• Applied Biological Chemistry
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• v.27 no.4
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• pp.231-237
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• 1984

Culture conditions for yeast production from the acid hydrolyzate of the 2nd waste composts of oyster mushroom (Pleurotus ostreatus) were determined. Among the yeast strains tested, Candida quilliermondii JAFM 215, which was culture at $30^{\circ}C$, pH 5.0, showed good culture yield. Yeast production was the highest yield with the medium composition of 0.3% $NH_4Cl$, 0.15% $KH_2PO_4$, 0.02% $MgSO_4{\cdot}7H_2O$, and 0.05% $CaCl_2$. Yeast growth was increased at the concentration of 0.001 to 0.01% furfural, but at the higher concentration the yeast growth was inhibited. Utilization rate of sugar was 86.2%, and yield of yeast from sugar was 50.45%. Crude protein of yeast ranged from 50 to 52%.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1085-1088
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• 2011

Heavy metal concentration as well as chemical composition were surveyed in commercial liquid pig manure to provide the basic information for mitigation research of hazardous material to agro-product. Seventy-five samples of liquid pig manure were collected and analyzed from 2009 to 2010 nationwide. Average contents of T-N, $P_2O_5$, and $K_2O$ were 0.29%, 0.08%, and 0.11%, respectively. The contents of heavy metals ranged from 0.001~0.083 for As, 0.001~0.108 for Cd, 0.002~0.495 for Cr, 0.07~47.8 for Cu, ND~0.005 for Hg, 0.035~1.033 for Ni, ND~0.291 for Pb, and $0.75{\sim}342.4mg\;L^{-1}$ for Zn, respectively. It was noted that among 75 samples, only four samples exceeded the Zn guideline ($130mg\;L^{-1}$) of liquid fertilizer derived from livestock manure but others were not exceeded the regulation.

• Journal of fish pathology
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• v.36 no.2
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• pp.379-388
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• 2023

Experiments were performed to investigate hypoxia tolerance with body size of red seabream (Pagrus major) at 24℃. The rate of oxygen consumption was measured at an interval of 10 min using automated intermittent-flow respirometry. The weight-specific standard metabolic rate (SMR, mg O₂ kg^-1hr^-1) and critical oxygen saturation (S_crit, % air saturation) of the fish were measured under normoxic condition and progressive hypoxia with 0.6-786 g of fish weight (W), respectively. SMR typically decreased with increasing body weight based on SMR=351.59·W^-0.195 (r²=0.934). S_crit was higher in larger fish than those of smaller fish in the range of 17.3-24.4%. The result of this study suggests that the smaller seabream can withstand in hypoxic waters better than the larger ones.

• Journal of Surface Science and Engineering
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• v.57 no.5
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• pp.406-415
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• 2024

Using DC magnetron sputtering, we deposited a bilayer composed of a seed layer consisting of Ti, Cr, Co, and Zr, and an overlayer of Ag on MgO(001) single crystal substrates, creating self-assembled nanostructures. When Ti was used as the seed layer, it was observed that the formed nano-dots inherently aggregated into dot shapes. Additionally, Cr, Co, and Zr were chosen to investigate their influence on SLAA(Seed layer Assisted Agglomeration) depending on the seed layer material, revealing different shapes of the formed nano-dots. Moreover, it was observed that aggregation was inhibited as the thickness of the seed layer exceeded a critical point. X-ray diffraction analysis of the Ti seed layer revealed epitaxial growth of Ag along the (001) direction of the MgO substrate. In contrast, no epitaxial growth was observed when Cr, Co, and Zr were used as seed layer materials. Ultimately, Ti was identified as the most suitable seed layer material for the fabrication of self-assembled nanostructures utilizing the aggregation phenomenon of the bilayer. This research is deemed sufficiently valuable in addressing the limitations associated with the low productivity and high cost of current nano thin film processes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.162-162
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• 2003

최근에 산화물 인공격자의 우수한 특성으로 인하여 활발한 연구가 진행되고 있다. 본 연구에서는 펄스레이저 증착방법을 이용하여 산소분압 100mTorr, $650^{\circ}C$에서 LSCO/MgO 기판위에 La-50mol% 첨가된 SrTiO$_3$ (SLTO)와 SrTiO$_3$ 를 적층시켜 산화물 인공격자를 만들어 결정구조에 대하여 연구하였다. SrTiO$_3$ (STO)는 상온에서 3.904$\AA$인 cubic perovskite 구조를 가지고 있다. 일반적으로 La$^{3+}$ (1.14$\AA$)은 Sr$^{2+}$(1.12$\AA$)과 이온반경이 거의 유사하기 때문에 ABO 페로브스카이트 구조의 A자리에 치환될 것으로 기대되며 또한 Sr$^{2+}$ 자리에 La$^{3+}$ 가 치환되므로써 발생하는 charge compensation은 Sr 자리에 Vacancy 생성으로 판단된다. 인공격자의 성장확인을 위하여 SLTO와 STO를 10층씩 증착하여 XRD분석을 통하여 평가하여 보았다. 확인된 결과를 바탕으로 산화물 인공격자의 적층 주기를 SLTO layer를 한층으로 고정시키고 STO를 한 층에서 다섯 층까지 다양하게 변화시켰다. 본 연구의 목적은 산화물 인공격자에서 결정결함을 제어하여 소자에 응용할 수 있는 전기적 물성을 평가하기 위함이다. X-ray diffraction 결과 SLTO/STO 인공격자는 (001) 방향으로 우선배향하였으며 적층주기에 따라 격자상수의 변화를 보였다. AES의 depth profile 분석을 통하여 La의 분포를 확인하였으며, HRTEM 분석을 통하여 미세구조분석을 실시하였다.

• Journal of the Korean Ceramic Society
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• v.45 no.1
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• pp.1-29
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• 2008

In last two decades, an impressive progress has been recorded in terms of developing new materials or refining existing material composition/microstructure in order to obtain better performance in biomedical applications. The success of such efforts clearly demands better understanding of various concepts, e.g. biocompatibility, host response, cell-biomaterial interaction. In this article, we review the fundamental understanding that is required with respect to biomaterials development, as well as various materials and their properties, which are relevant in applications, such as hard tissue replacement. A major emphasize has been placed to present various design aspects, in terms of materials processing, of ceramics and polymer based biocomposites, Among the bioceramic composites, the research results obtained with Hydroxyapatite (HAp)-based biomaterials with metallic (Ti) or ceramic (Mullite) reinforcements as well as $SiO_2-MgO-Al_2O_3-K_2O-B_2O_3-F$ glass ceramics and stabilized $ZrO_2$ based bioinert ceramics are summarized. The physical as well as tribological properties of Polyethylene (PE) based hybrid biocomposites are discussed to illustrate the concept on how can the physical/wear properties be enhanced along with biocompatibility due to combined addition of bioinert and bioactive ceramic to a bioinert polymeric matrix. The tribological and corrosion properties of some important orthopedic metallic alloys based on Ti or Co-Cr-Mo are also illustrated. At the close, the future perspective on orthopedic biomaterials development and some unresolved issues are presented.

• Journal of the Mineralogical Society of Korea
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• v.8 no.2
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• pp.73-85
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• 1995

춘천 지역 구봉산층군 내에서 산출되는 백색 및 흑회색 투감섬석에 대하여 전자현미분석과 리트벨트법에 의하여 결정화학적 특징이 연구되었다. 화학 조성상 백색 투감섬석 (WHT)은 흑회색형 (BLT)에 비하여 Al과 Na의 양은 많고, Mg와 Ca의 양은 적은 차이를 보여준다. 단위포의 크기에 있어 b축의 길이는 WHT가 BLT보다 약 0.013$\AA$ 크다. 이는 후자의 M(4) 자리에 보다 많은 Na와 Mg가 치환된 결과로서 계사된 $\AA$로 잘 일치하고 있다. 자리 점유율에 있어 BLT의 경우 모든 Al이 T(2)에 채워지며, WHT에서는 T(1), T(2)에 각각 0.138, 0.181씩 Si를 치환하고 있다. M(1), M(2), 및 M(3)는 모두 Mg에 의해 채워지고 있으며, Ca가 채워지는 M(4)에는 BLT에서는 소량의 Mg가 들어 있다. (001) 방향으로 투각섬석의 구조를 작도해 보면, WHT에서는 사면체의 바닥면이 T(1) 안쪽으로 다소 기울어져 있으나, BLT에서는 T(1)과 T(2)가 서로 마주보며 기울어져 있는 특이한 양상을 보여준다. 이러한 구조상의 차이점은 앞으로 보다 많은 투각섬석에 대한 구조적인 연구를 수행할 필요가 있음을 보여준다.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.1-6
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• 2019

The flavonoid, isokaempferide, has various biological activities such as hepatoprotective, antimicrobial and antiproliferative effect and is extracted from Amburana cearensis and Cirsium rivulare (Jacq.). Biotransformation is an alternative tool for the synthesis of value-added flavonoids with inexpensive substrates. Here, to synthesize isokaempferide from naringenin, two genes, PFLS and Rice O-mthyltransferae-9 were introduced in Escherichia coli. Although isokaempferide was successfully synthesized, the amount of biosynthesis was no high. In order to increase the yields of isokaempferide, S-adenosylmethionine (SAM) used as a methyl donor was increased by deleting MetJ, which is a transcriptional regulator related to SAM biosynthetic pathway. Next we optimized the cell concentration and substrate feed concentration with the engineered E. coli strain. Through these strategies, the biosynthesis of isokaempferide was increased up to 87 mg/L.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.365-370
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• 2009

An experiment was conducted to evaluate the effect of different levels of supplemental selenomethionine (Se-Met) on growth performance and serum antioxidant status in Taihang Black goats. Fifty 16-week-old goats with an average body weight of 12.5${\pm}$0.5 kg were randomly assigned to five treatments fed a basal diet (0.049 mg Se/kg DM) supplemented with 0 (control), 0.10, 0.30, 0.50 and 1.00 mg of Se/kg DM (form Se-Met) for 80 days. Average daily gain and feed efficiency were higher (p<0.05) in the groups supplemented with 0.30 to 0.50 mg Se/kg DM compared with the control group. However, Se-Met supplementation had no influence on average daily feed intake (p>0.05). Se-Met supplementation significantly increased (p<0.01) the activity of glutathione peroxidase enzymes (GSH-Px) and superoxide dismutase (SOD) in serum. The group supplemented with 0.50 mg Se/kg DM had the highest activity of GSH-Px compared with other groups (p<0.05). Serum SOD activity was higher (p<0.05) in goats supplemented with both 0.30 and 0.50 mg Se/kg DM than in control goats and goats supplemented with 1.00 mg Se/kg DM. Serum glutathione-S-transferase (GST) activity and malondialdehyde (MDA) concentration were significantly decreased (p<0.05) in goats supplemented with 0.30, 0.50 and 1.00 mg Se/kg DM compared with control values. These results indicated that Se-Met supplementation markedly improved the antioxidant status in goats. Blood Se concentration increased linearly (p<0.001) and quadratically (p<0.001) as the level of supplemental Se-Met increased. The concentration of Se in the control diet (0.049 mg Se/kg DM) did not satisfy the Se requirement in goats as indicated by reduced growth rate, feed efficiency, activities of GSH-Px and SOD in serum, and blood Se concentrations. In conclusion, it is recommended that 0.30 to 0.50 mg of Se/kg DM from Se-Met (total diet Se of 0.349 to 0.549 mg/kg DM) be supplied in the diet of Taihang Black goats to enhance growth performance and improve antioxidant status.