• 대한물리치료사협회지
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• 제13권1호
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• pp.5-17
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• 1992

Depression in Spinal Cord Injury Patients Kang, Soon Hee, M.Ed., R.P.T. Dept. of Rehabilitation Medicine, Kyung-Hee University Medical Center Depressions have the potential to affect adversely the rehabilitation of patients with spi-nal cord iniury. The present study examined depression, functional independence, and demographic and medical characteristics for 49 spinal cord injury(SCI) patients. This investigation involved the administration of the Beck Depression Inventory, the Modified Barthel Index, and aquestionnaire consisted of 14 items, The results were as follows .1. Compared to normal subjects, SCI patients had significantly higher BDI scores.2. When the cut-off point of HDI scores was assumed 21, 26.1% of normal subjeets and 75.5% of SCI patients appeared to be depressed. Depression in SCT patients were not related with age, sex, marital status, injury evel, severity, duration, pain, functional independence and medical charge. Depression in SCI patients were related with education level, economic level, age at injury, motivation. Depression in normal subjects were related with age, education level, economic level, but not related with sex, marital status. There were significant differences at 30 items of BDI between normal subjects and SCI patients. The items were as fellows . 1 sadness, 2 pessimism, 3 failure, 4 dissat-isfaction, 5 guilt, 6 punishment. 7 self-dislike 9 suicidal, 10 crying, 11 irritability, 12withdrawl, 13 indecisive, 14 self-image, IS work inhibition, 16 insomnia, 17 fatigue,18 anorexia, 19 weight loss, 20 hypochondria, 21 libido loss.

• Clinical Nutrition Research
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• 제5권3호
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• pp.172-179
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• 2016

Acid food indicators can be used as pH indicators for evaluating the quality and freshness of fermented products during the full course of distribution. Iron oxide particles are hardly suspended in water, but partially or completely agglomerated. The agglomeration degree of the iron oxide particles depends on the pH. The pH-dependent particle agglomeration or dispersion can be useful for monitoring the acidity of food. The zeta potential of iron oxide showed a decreasing trend as the pH increased from 2 to 8, while the point of zero charge (PZC) was observed around at pH 6.0-7.0. These results suggested that the size of the iron oxide particles was affected by the change in pH levels. As a result, the particle sizes of iron oxide were smaller at lower pH than at neutral pH. In addition, agglomeration of the iron oxide particles increased as the pH increased from 2 to 7. In the time-dependent aggregation test, the average particle size was 730.4 nm and 1,340.3 nm at pH 2 and 7, respectively. These properties of iron oxide particles can be used to develop an ideal acid indicator for food pH and to monitor food quality, besides a colorant or nutrient for nutrition enhancement and sensory promotion in food industry.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.139-139
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• 2012

With angle resolved photoemission spectroscopy (ARPES), the surface electronic band structures of Pt3Co (111) and Pt3Ni (111) single crystals are investigated, which allow to study the bonding interaction between chemically absorbed atomic oxygen and its surfaces. The d-band electrons of subsurface TM are separated from the direct chemical bonding with atomic oxygen. That is, the TM does not contribute to direct chemical bonding with oxygen. From the density functional theory (DFT) calculations, it is identified that the main origin of improved oxygen absorption property, i.e. softening of Pt-O bonding, is due to the suppression of Pt surface-states which is generated from change of interlayer potential, i.e. charge polarization, between Pt-top and TM-subsurface. Our results point out the critical roles of subsurface TM in modifying surface electronic structures, which in turn can be utilized to tune surface chemical properties.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2861-2866
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• 2012

Results of the comparisons of various density functional theory (DFT) methods with different basis sets for predicting the molecular geometry of TPOP24N-Oxide macrocycle, an oxoporphyrin N-oxide, are reported in this paper. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-$31G^*$, 6-31+G (d, p), 6-311+G (d, p), and 6-311++G (d, p), are also considered. The M06-2X/6-$31G^*$ level is superior to all other density functional methods used in predicting the geometry of TPOP24N-Oxide. The geometries of regioisomeric chlorin N-oxide and oxoporphyrin N-oxide are reported using M06-2X/6-$31G^*$ method. The geometry effects of oxoporphyrin and chlorin N-oxide regioisomers are increased ${\beta}-{\beta}$ bond lengths by N-oxidation because the bond overlap index due to charge transfers is decreased. In N-oxidation ring (II, III), angles that include ${\beta}-{\beta}$ bond length increase as the bond overlap index of ${\beta}-{\beta}$ bond is decreased by N-oxidation. The potential energy surfaces of chlorin N-oxide and oxoporphyrin N-oxide are explored by M06-2X/6-$31G^*$, and single-point calculations are performed at levels up to M06-2X/6-311++G (d, p). Total and relative energies are then calculated. The results indicate that chlorin 24 N-oxides are more stable than chlorin 22 N-oxides in chlorin N-oxide regioisomers. Moreover, TPOP24N-Oxide is less stable than TPOP22N-Oxide.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.93-104
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• 2011

Two hepcidin paralogs (ojhamp1 and ojhamp2) were isolated and characterized from a euryhaline Javanese ricefish (Oryzias javanicus: Beloniformes). The ojhamp1 cDNA encoded 90 or 91 amino acids (aa) of a typical HAMP1 preproprotein. This preproprotein is believed to cleave and yield the 66 or 67 aa-proprotein, followed by the 26 aa-mature peptide, composed of 8 conserved cysteine residues and the QSHL amino terminal motif. The ojhamp2 cDNA encoded 89 aa of HAMP2 preproprotein, cleaved to yield a 65 aa proprotein, and subsequently the 25 aa-mature peptide. The mature OJHAMP1 possessed a cationic isoelectric point (pI), whereas OJHAMP2 had an anionic charge. At the genomic level, both ojhamp1 and ojhamp2 share a conserved tripartite structure (three exons interrupted by two introns) with other vertebrate hepcidin genes. However, the ojhamp1 was shown to exist as two distinct mRNA species, encoding 90 or 91 aa, due to alternative splicing at the junction site between intron I and exon II. Both ojhamp1 and ojhamp2 transcripts were detected in a wide range of tissue types with varying levels of basal expression, although the highest expression was observed in the liver for both isoforms. Transcriptional response to bacterial challenge using Edwardsiella tarda showed that ojhamp1 was moderately upregulated in the liver but remained unchanged in the kidney. However, the ojhamp2 was significantly suppressed in both the kidney and liver, suggesting a potential diversification between the two paralogs.

• 한국환경과학회지
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• 제20권2호
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• pp.185-197
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• 2011

Sorption of chlorinated pesticides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine onto natural clays (montmorillonite and zeolite) modified with cationic surfactant, hexadecyltrimethyl-ammonium (HDTMA) and a natural soil was investigated using batch adsorbers. The clays were transformed from hydrophilic to hydrophobic by the cation exchange between clay surface and HDTMA up to 100% of the cation exchange capacity (CEC). Physicochemical characteristics of the sorbents such as pH, PZC (point of zero charge), organic carbon content ($f_{oc}$), fourier transform infrared spectroscopy (FT-IR), differential thermogravimetric analysis (DTGA) and X-ray diffraction (XRD) were analyzed. Sorption isotherm models such as Freundlich and Langmuir were fitted to the experimental data, resulting Langmuir model ($R^2$ > 0.986) was fitted better than Freundlich model ($R^2$ > 0.973). Sorption capacity ($Q^0$) for 2,4-D and atrazine was in the order of HDTMA-montmorillonite > HDTMA-zeolite > natural soil corresponding to the increase in organic carbon content ($f_{oc}$). The sorption of the pesticides was also affected by pH. The sorption of 2,4-D decreased with the increase in pH, whereas that of atrazine was not changed. This indicated that the sorption capacity ($Q^0$) of 2,4-D and atrazine was not affected by the solution pH because they exist as anionic (deprotonated) forms at pH above pKa. The results indicate that organoclay has a promising potential to reduce chlorinated pesticides in the effluent from golf courses.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.523-523
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• 2012

As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.

• Macromolecular Research
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• 제16권6호
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• pp.492-502
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• 2008

This study examined the adsorption of a synthetic cutting fluid and cutting fluid effluent on chitosan and SDS-modified chitosan, Chitosan and SDS-modified chitosan were prepared in form of beads and fibers. A series of batch experiments were carried out as a function of the initial concentration of cutting fluid, contact time and pH of the fluid. The contact angle study suggested that the SDS-modified chitosan was more hydrophobic than chitosan. The Zeta potential study showed that chitosan, SDS-modified chitosan and synthetic cutting fluid had a point of zero charge (PZC) at pH 7.8, 9 and 3.2, respectively. SDS-modified chitosan has a greater adsorption capacity than chitosan. The experimental results show that adsorption capacity of the cutting fluid on 1.0 g of SDS-modified chitosan at pH 3 and for a contact time of 120 min was approximately 2,500 g/kg. The adsorption capacity of chitosan and SDS-modified chitosan increased with decreasing pH. The Langmuir, Freundlich, and Brunauer Emmett and Teller (BET) adsorption models were used to explain the adsorption isotherm. The Langmuir isotherm fitted well with the experimental data of chitosan while the BET isotherm fitted well with the SDS-modified chitosan data. Pseudo first- and second-order kinetic models and intraparticle diffusion model were used to examine the kinetic data. The experimental data was fitted well to a pseudo second-order kinetic model. The significant uptake of cutting fluid on chitosan and SDS-modified chitosan were demonstrated by FT-IR spectroscopy, SEM and heat of combustion.

• 한국광물학회지
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• 제28권2호
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• pp.95-108
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• 2015

광산배수가 지표에 노출되거나 주변 수계로 유입됨에 따라 나노크기의 철 교질물질이 형성되며, 이러한 철 교질물질은 심미적 오염을 발생시킬 뿐만 아니라 수생태계에도 악영향을 미친다. 이를 제어하기 위해 철 나노물질의 거동특성을 파악하는 것이 매우 중요한데, 아직까지 이에 대한 연구가 미흡하다. 본 연구는 영가철과 자철석을 이용하여 배경용액의 pH와 조성, 그리고 자연유기물에 따른 철 나노물질의 거동특성을 고찰하기 위해 수행되었다. 이를 위해 동적광산란분석기를 이용하여 철 나노물질의 입자크기와 표면 제타전위를 측정하였으며, DLVO (Derjaguin, Landau, Verwey, and Overbeek) 이론에 적용하여 응집 및 분산 등의 거동특성을 비교하였다. 철 나노물질은 영전하점 pH 근처에서는 입자간의 전기적 인력으로 인한 응집이 발생되며, 그보다 pH가 낮거나 높으면 전기적 반발력에 의해 분산이 잘되는 것을 확인하였다. 배경용액 내 양이온이 음이온보다 거동특성에 더 큰 영향을 끼치는 것을 확인하였으며, 특히 1가 양이온보다 2가 양이온이 입자표면간의 전기적인 인력 및 반발력에 더 큰 영향을 주는 것을 알 수 있었다. 수용상의 자연유기물은 철 나노물질을 코팅함으로써 표면을 음전하로 띠게 하여 분산이 잘 되게 하는 것을 확인하였다. 동일한 환경조건에서 자철석보다 영가철이 응집이 더 잘 되는 것으로 나타났는데, 이는 영가철의 낮은 안정성과 빠른 반응성으로 인해 철 산화물로 변질되기 때문인 것으로 판단된다.

• 한국광물학회지
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• 제22권3호
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• pp.177-189
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• 2009

철 (산수)산화물은 높은 반응성과 큰 비표면적 등의 특성을 갖는 이차광물로서 환경관련 산업이나 연구에서 무기 및 유기 오염물질들을 효과적으로 제거할 수 있는 수착제로 널리 활용되어 오고 있다. 이러한 철 (산수)산화물들 중에서 침철석(${\alpha}$-FeOOH)은 지중에서 가장 많이 분포하고 안정된 광물로 알려져 있다. 본 연구에서는 이러한 침철석을 이용하여 비소를 제거하는데 있어서 주요한 기작인 흡착반응에 대하여 알아보았다. 순수한 침철석을 얻기 위하여 실험실에서 합성하였으며, 침철석의 다양한 광물학적, 물리화학적 특성들을 분석하여 비소와의 흡착반응을 해석하는데 이용하였다. 그리고 비소의 화학종별 침철석에 대한 흡착특성을 비교하기 위하여 흡착 등온식을 얻기 위한 평형흡착실험, pH에 따른 흡착실험, 흡착반응속도 실험 등을 수행하였다. 합성된 침철석의 영전하점(point of zero charge, PZC)은 7.6으로 다른 철 (산수)산화물들에 비해서 상대적으로 약간 높은 값으로 측정되었다. 침철석의 비표면적은 $29.2\;m^2/g$으로 다른 철 (산수)산화물들에 비해 비교적 낮게 나타나서 흡착력이 다소 떨어질 것으로 예상되었다. 침철석에 대한 친화도는 3가 비소(아비산 이온)가 5가 비소(비산 이온)보다 훨씬 더 커서 동일한 pH 조건에서 3가 비소가 5가 비소보다 침철석에 많이 흡착되는 것으로 조사되었다. pH에 따른 비소 화학종별 흡착특성을 살펴보면 3가 비소는 중성의 pH 범위(7.0~9.0)에서 가장 높은 흡착을 보였으며, 산성 또는 염기성 pH 조건에서는 흡착량이 크게 감소하는 것으로 나타났다. 5가 비소의 경우에는 낮은 pH 조건에서 가장 흡착이 잘 일어났으며 pH가 증가함에 따라서 흡착은 감소하는 것으로 나타났다. 이러한 거시적인 현상은 pH에 따라서 각 비소종의 화학적 존재형태와 침철석의 표면 전하가 변하기 때문에 발생하는 정전기적인 작용에 의한 것으로 생각된다. 침철석과 비소와의 흡착반응속도를 가장 잘 모사하는 반응속도 모델은 parabolic diffusion 모델인 것으로 평가되었으며, 회귀 분석 결과 5가 비소가 3가 비소보다 반응속도상수가 크게 나타났다.