본 연구는 칼슘과 철 그리고 철과 아연의 상호작용과 신뢰성있는 영양정보를 제공하기 위해 영양강조표시제품중 칼슘, 철, 아연의 함량을 분석하고 표시량과 분석값을 비교하였다. 칼슘, 철, 아연을 강조표시한 제품(시리얼, 과자, 두유, 초콜릿가공품, 기타코코아가공품, 당류가공품, 과줆채음료, 고형차) 총 42건을 수거하였으며 칼슘, 철, 아연은 무기성분의 건식분해법으로 전 처리한 후 Inductively Coupled Plasma Spectrometer (ICP)로 실험하였다. 칼슘이 강조표시된 제품 42건에 대한 표시량 비율은 87~176%이 었으며, 철이 강조표시된 제품 13건에 대한 표시량 비율은 84~167%, 아연이 강조표시된 제품 6건에 대한 표시량비율은 98~275%였다. 모든 분석값이 표시량 대비 80% 이상으로 식품 등의 표시기준을 충족하였다. 칼슘과 철의 상호작용은 한국인의 칼슘 섭취가 1일 권장량의 68.7% 수준으로 부족하므로 칼슘의 과다섭취로 인한 철의 흡수방해는 우려할 만한 상황은 아닌 것으로 보인다. 또한, 분석한 영양강조표시제품의 철과 아연의 함량 비율이 1.53:1이 최대였으므로 철의 과다섭취로 인한 아연의 흡수방해는 우려할 만한 상황은 아니었다. 그러나 업체에서는 칼슘, 철, 아연을 강조한제품을 생산할 시에 영양소의 상호작용을 고려하여 생산을 해야 할 것이고 소비자에게 정확한 영양정보를 제공하고 적정량의 영양섭취를 위해서는 지속적인 모니터링을 통해 식품표시에 대한 주기적인 관리가 필요할 것으로 생각된다.

Zinc (Zn2+) is one of essential factors during mammalian oocyte maturation and fertilization. Previous studies showed that depletion of cellular Zn by metalion chelator impair asymmetric division of oocyte. But the detailed mechanism of these phenomena is unclear. We found that depletions of zinc by cell-permeable heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine (TPEN) caused the decrease of cytoplasmic actin mesh level. Spire2-GFP is co-localized with zinc at the cortex and intracellular vesicle. By the treatment of TPEN, number of Spire2-GFP decorated vesicle is drastically decreased, indicating that Zn2+is essential for the localization of the spire in mouse oocyte. Two putative zinc-binding regions were located in the C-terminal part of Spire2. Mutations of zinc binding site on spire abolish its localization at the intracellular vesicle. Over expression of C-terminal region containing zinc binding site of spire impair oocyte maturations and decrease cytoplasmic actin mesh. Taken together, these results suggest that intracellular zinc is crucial for the proper localizations of spire in the mouse oocyte, and unraveling the novel regulatory mode of actin nucleator spire by Zn2+.

In this study, an environment-friendly synthetic strategy to process zinc oxide nanocrystals is reported. The biosynthesis method used in this study is simple and cost-effective, with reduced solvent waste via the use of fruit peel extract as a natural ligation agent. The formation of ZnO nanocrystals using a rambutan peel extract was observed in this study. Rambutan peels has the ability to ligate zinc ions as a natural ligation agent, resulting in ZnO nanochain formation due to the presence of an extended polyphenolic system over the whole incubation period. Via transmission electron microscopy, successful formation of zinc oxide nanochains was confirmed. TEM observation revealed that the bioinspired ZnO nanocrystals were spherical and/or hexagonal particles with sizes between 50 and 100 nm.

Zinc Sulfide (ZnS) is one of the II-VI semiconducting materials, having novel fundamental properties and diverse areas of application such as light-emitting diodes (LEDs), electroluminescence, flat panel displays, infrared windows, catalyst, chemical sensors, biosensors, lasers and biodevices, etc. However, despite the remarkable versatility and prospective potential of ZnS, research and development (R&D) into its applications has not been performed in much detail relative to research into other inorganic semiconductors. In this study, based on global patent information, we analyzed recent technical trends and the current status of R&D into ZnS applications. Furthermore, we provided new technical insight into ZnS applicable fields using in-depth analysis. Especially, this report suggests that ZnS, due to its infrared-transmitting optical property, is a promising material in astronomy and military fields for lenses of infrared systems. The patent information analysis in this report will be utilized in the process of identifying the current positioning of technology and the direction of future R&D.

The properties of zinc oxynitride semiconductors and their associated thin film transistors are studied. Reactively sputtered zinc oxynitride films exhibit n-type conduction, and nitrogen-rich compositions result in relatively high electron mobility. Nitrogen vacancies are anticipated to act as shallow electron donors, as their calculated formation energy is lowest among the possible types of point defects. The carrier density can be reduced by substituting zinc with metals such as gallium or aluminum, which form stronger bonds with nitrogen than zinc does. The electrical properties of gallium-doped zinc oxynitride thin films and their respective devices demonstrate the carrier suppression effect accordingly.

We present an excellent detection for nitrogen monoxide (NO) gas using polycrystalline ZnO wire-like films synthesized via a simple method combined with sputtering of Zn metallic films and subsequent thermal oxidation of the sputtered Zn nanowire films in dry air. Structural and morphological characterization revealed that it would be possible to synthesize polycrystalline hexagonal wurtzite ZnO films of a wire-like nanostructure with widths of 100-150 nm and lengths of several microns by controlling the sputtering conditions. It was found from the gas sensing measurements that the ZnO wirelike thin film gas sensor showed a significantly high response, with a maximum value of 29.2 for 2 ppm NO at 200 oC, as well as a reversible fast response to NO with a very low detection limit of 50 ppb. In addition, the ZnO wire-like thin film gas sensor also displayed an NO-selective sensing response for NO, O2, H2, NH3, and CO gases. Our results illustrate that polycrystalline ZnO wire-like thin films are potential sensing materials for the fabrication of NO-sensitive high-performance gas sensors.

The effect of sintering temperature on the microstructure, electrical and dielectric properties of (V, Mn, Co, Dy, Bi)- codoped zinc oxide ceramics was investigated in this study. An increase in the sintering temperature increased the average grain size from 4.7 to 10.4 μm and decreased the sintered density from 5.47 to 5.37 g/cm3. As the sintering temperature increased, the breakdown field decreased greatly from 6027 to 1659 V/cm. The ceramics sintered at 900 oC were characterized by the highest nonlinear coefficient (36.2) and the lowest low leakage current density (36.4 μA/cm2). When the sintering temperature increased, the donor concentration of the semiconducting grain increased from 2.49 × 1017 to 6.16 × 1017/cm3, and the density of interface state increased from 1.34 × 1012 to 1.99 × 1012/cm2. The dielectric constant increased greatly from 412.3 to 1234.8 with increasing sintering temperature.

투명 전도성 산화물로서 알루미늄과 붕소가 함께 도핑된 아연산화물(AZOB)이 900℃에서 분무 열분해법에 의해 제조되었다. 얻어진 마이크론 크기의 AZOB 분말은 알루미늄, 붕소 및 아연의 수용액으로부터 얻어진다. 분무 열분해로 얻어진 마이크론 크기의 AZOB 분말은 700℃에서 두 시간동안의 후 소성 과정과 24 시간 동안의 볼 밀링을 통해 나노 크기의 AZOB으로 변환된다. AZOB을 구성하는 일차 입자의 크기를 Debye-Scherrer 식에 의해 계산하였고 압축된 AZOB 펠렛의 표면 저항을 측정하였다.

ZnO nanoparticles in the size range from 5 to 15 nm were prepared by zinc-lithium-acetate system. The morphologies and structures of ZnO were characterized by TEM, XRD and FT-IR spectra. UV-visible results shows that the absorption of ZnO nanoparticles is blue shifted with decrease in particles size. Furthermore, photoluminescence spectra of the ZnO nanoparticles were also investigated. The ZnO nanoparticles have strong visible-emission intensity and their intensities depend upon size of ZnO nanoparticles.

The electrochemical performance for the corrosion of zinc anodes according to particle size and shape as anode in Zn/air batteries was study. We prepared five samples of Zn powder with different particle size and morphol- ogy. For analysis the particle size of theme, we measured particle size analysis (PSA). As the result, sample (e) had smaller particle size with 10.334 µm than others. For measuring the electrochemical performance of them, we measured the cyclic voltammetry and linear polarization in three electrode system (half-cell). For measuring the morphology change of them before and after cyclic voltammetry, we measured Field Emission Scanning Electron Microscope (FE- SEM). From the cyclic voltammetry, as the zinc powder had small size, we knew that it had large diffusion coefficient. From the linear polarization, as the zinc powder had small size, it was a good state with high polarization resistance as anode in Zn/air batteries. From the SEM images, the particle size had increased due to the dendrite formation after cyclic voltammetry. Therefore, the sample (e) with small size would have the best electrochemical performance between these samples.

We report on the NO gas sensing properties of non-directional ZnO nanofibers synthesized using a typical electrospinning technique. These non-directional ZnO nanofibers were electrospun on an SiO2/Si substrate from a solution containing poly vinyl alcohol (PVA) and zinc nitrate hexahydrate dissolved in distilled water. Calcination processing of the ZnO/PVA composite nanofibers resulted in a random network of polycrystalline ZnO nanofibers of 50 nm to 100 nm in diameter. The diameter of the nanofibers was found to depend primarily on the solution viscosity; a proper viscosity was maintained by adding PVA to fabricate uniform ZnO nanofibers. Microstructural measurements using scanning electron microscopy revealed that our synthesized ZnO nanofibers after calcination had coarser surface morphology than those before calcination, indicating that the calcination processing was sufficient to remove organic contents. From the gas sensing response measurements for various NO gas concentrations in dry air at several working temperatures, it was found that gas sensors based on electrospun ZnO nanofibers showed quite good responses, exhibiting a maximum sensitivity to NO gas in dry air at an operating temperature of 200˚C. In particular, the non-directional electrospun ZnO nanofiber gas sensors were found to have a good NO gas detection limit of sub-ppm levels in dry air. These results illustrate that non-directional electrospun ZnO nanofibers are promising for use in low-cost, high-performance practical NO gas sensors.

본 연구는 말똥성게(Hemicentrotus pulcherrimus)의 생식세포 및 pluteus 유생을 이용하여 중금속인 납(lead, Pb)과 아연(zinc, Zn)의 독성을 조사였다. H. pulcherrimus 배우자 및 배아에 미치는 Pb과 Zn의 독성은 각각 31, 63, 125, 250, 500 ppb 및 16, 31, 63, 125, 250 ppb의 농도에서 조사하였다. 0.5 M KCl 용액을 이용하여 방란 및 방정을 유도하였고, 수정률 및 정상 배아발생률의 조사는 수정 후 각각 10분 및 64시간째 관찰하여 시행하였다. Pb 노출 시 수정률은 대조군과 비교하여 유의적인 변화가 없었다. 그러나 정상 배아발생률은 농도가 높을수록 농도의존적으로 유의적인 감소를 보였다. Zn을 노출시켰을 경우 수정률과 정상 배아발생률은 농도가 높을 수록 농도의존적인 유의적 감소를 나타냈다. H. pulcherrimus의 정상 배아 발생에 대한 독성치는 각각 Pb (반수영향농도 (EC50) 45.13 ppb, 95% Cl 40.12~50.05 ppb), Zn (반수영향농도(EC50) 19.82 ppb, 95% Cl 18.26~21.31 ppb)로 나타났다. 또한 Pb과 Zn의 무영향농도(NOEC)는 각각 ⁄31.25 ppb 및 ⁄15.63 ppb로 나타났고, 최소영향농도(LOEC)는 31.25 및 15.63 ppb로 나타났다. 본 연구 결과, H. pulcherrimus의 초기 배아발생 과정은 Pb과 Zn 등의 중금속에 높은 민감성을 보인다. 따라서 H. pulcherrimus는 해양생태계 위해 평가를 위한 시험생물로서 사용이 가능하다고 사료된다.

We report on the NO gas sensing properties of Al-doped zinc oxide-carbon nanotube (ZnO-CNT) wire-like layered composites fabricated by coaxially coating Al-doped ZnO thin films on randomly oriented single-walled carbon nanotubes. We were able to wrap thin ZnO layers around the CNTs using the pulsed laser deposition method, forming wire-like nanostructures of ZnO-CNT. Microstructural observations revealed an ultrathin wire-like structure with a diameter of several tens of nm. Gas sensors based on ZnO-CNT wire-like layered composites were found to exhibit a novel sensing capability that originated from the genuine characteristics of the composites. Specifically, it was observed by measured gas sensing characteristics that the gas sensors based on ZnO-CNT layered composites showed a very high sensitivity of above 1,500% for NO gas in dry air at an optimal operating temperature of 200˚C; the sensors also showed a low NO gas detection limit at a sub-ppm level in dry air. The enhanced gas sensing properties of the ZnO-CNT wire-like layered composites are ascribed to a catalytic effect of Al elements on the surface reaction and an increase in the effective surface reaction area of the active ZnO layer due to the coating of CNT templates with a higher surface-to-volume ratio structure. These results suggest that ZnO-CNT composites made of ultrathin Al-doped ZnO layers uniformly coated around carbon nanotubes can be promising materials for use in practical high-performance NO gas sensors.

Both iron-deficient and zinc-sufficient diets have been known to be associated with a decreased risk of colon cancer. We investigated that effect of dietary zinc on the formation of colonic aberrant crypt foci (ACF) induced by azoxymethane (AOM) followed by dextran sodium sulfate in iron-deficient mice. Five-week old ICR mice were acclimated for 1 week and fed on iron-deficient diet (4.50 ppm iron) with three different zinc levels (0.01, 0.1, and 1.0 ppm) for 12 weeks. The total number of aberrant crypt (AC) and ACF was measured in the colonic mucosa after methylene blue staining. The total ACF numbers of low Zn (LZn), medium Zn (MZn) and high Zn (HZn) diet groups were 10.00 ± 2.67, 8.78 ± 3.12, and 7.96 ± 2.44, respectively and there were no significant differences among the groups. However, the total AC numbers of HZn (27.07 ± 3.88) and MZn (26.39 ± 5.59) diet groups were significantly low compared to LZn (22.57 ± 5.09) diet group (p<0.01). Cytosolic SOD activity was the highest in LZn diet group. But thiobarbituric acid-reactive substances level in liver was also the highest in LZn diet group compared to other groups. There is no difference in cell proliferation in mucous membrane among the groups, while apoptotic positive cells were increased in the HZn diet group. The high zinc diet exhibited decreased β-catenin-stained areas on the mucous membrane of colon compared to the LZn or MZn diet group. These findings indicate that dietary zinc might exert a modulating effect on development of ACF/AC in the mice with iron-deficient status.

Zinc oxide as an optoelectronic device material was studied to utilize its wide band gap of 3.37 eV and high exciton biding energy of 60 meV. Using anti-site nitrogen to generate p-type zinc oxide has shown a deep acceptor level and low solubility. To increase the nitrogen solubility in zinc oxide, group 13 elements (aluminum, gallium, and indium) was co-added to nitrogen. The effect of aluminum on nitrogen solubility in a 3×3×2 zinc oxide super cell containing 72 atoms was investigated using density functional theory with hybrid functionals of Heyd, Scuseria, and Ernzerhof (HSE). Aluminum and nitrogen were substituted for zinc and oxygen sites in the super cell, respectively. The band gap of the undoped super cell was calculated to be 3.36 eV from the density of states, and was in good agreement with the experimentally obtained value. Formation energies of a nitrogen molecule and nitric oxide in the zinc oxide super cell in zinc-rich conditions were lower than those in oxygen-rich conditions. When the number of nitrogen molecules near the aluminum increased from one to four in the super cell, their formation energies decreased to approach the valence band maximum to some degree. However, the acceptor level of nitrogen in zinc oxide with the co-incorporation of aluminum was still deep.

We report the structural characterization of BixZn1-xO thin films grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. By increasing the Bi flux during the growth process, BixZn1-xO thin films with various Bi contents (x = 0~13.17 atomic %) were prepared. X-ray diffraction (XRD) measurements revealed the formation of Bi-oxide phase in (Bi)ZnO after increasing the Bi content. However, it was impossible to determine whether the formed Bi-oxide phase was the monoclinic structure α-Bi2O3 or the tetragonal structure β-Bi2O3 by means of XRD θ-2θ measurements, as the observed diffraction peaks of the 2θ value at ~28 were very close to reflection of the (012) plane for the monoclinic structure α-Bi2O3 at 28.064 and the reflection of the (201) plane for the tetragonal structure β-Bi2O3 at 27.946. By means of transmission electron microscopy (TEM) using a diffraction pattern analysis and a high-resolution lattice image, it was finally determined as the monoclinic structure α-Bi2O3 phase. To investigate the distribution of the Bi and Bi-oxide phases in BiZnO films, elemental mapping using energy dispersive spectroscopy equipped with TEM was performed. Considering both the XRD and the elemental mapping results, it was concluded that hexagonal-structure wurtzite BixZn1-xO thin films were grown at a low Bi content (x = ~2.37 atomic %) without the formation of α-Bi2O3. However, the increased Bi content (x = 4.63~13.17 atomic %) resulted in the formation of the α-Bi2O3 phase in the wurtzite (Bi)ZnO matrix.