• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.226-236
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• 2020

Antibiotic resistance by pathogenic bacteria and fungi is one of the most serious global public health problems in the 21^st century, directly affecting human health and lifestyle. Pseudomonas aeruginosa and Staphylococcus aureus with strong resistance to the common antibiotics have been isolated from Intensive Care Unit patients at Zagazig Hospital. Thus, in this study we assessed the biocidal activity of nanoparticles of silver, copper and zinc synthesized by Fusarium solani KJ 623702 against these multidrug resistant-bacteria. The synthesized Metal Nano-particles (MNPs) were characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Zeta potential. The Fourier transform infrared spectroscopy (FTIR) result showed the presence of different functional groups such as carboxyl, amino and thiol, ester and peptide bonds in addition to glycosidic bonds that might stabilize the dispersity of MNPs from aggregation. The antimicrobial potential of MNPs by F. solani against the multidrug-resistant (MDR) P. aeruginosa and S. aureus in addition to the mycotoxigenic Aspergillus awamori, A. fumigatus and F. oxysporum was investigated, based on the visual growth by diameter of inhibition zone. Among the synthesized MNPs, the spherical AgNPs (13.70 nm) displayed significant effect against P. aeruginosa (Zone of Inhibition 22.4 mm and Minimum Inhibitory Concentration 21.33 ㎍/ml), while ZINC oxide Nano-Particles were the most effective against F. oxysporum (ZOI, 18.5 mm and MIC 24.7 ㎍/ml). Transmission Electron Microscope micrographs of AgNP-treated P. aeruginosa showed cracks and pits in the cell wall, with internalization of NPs. Production of pyocyanin pigment was significantly inhibited by AgNPs in a concentration-dependent manner, and at 5-20 ㎍ of AgNPs/ml, the pigment production was reduced by about 15-100%, respectively.

• 한국식품과학회지
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• 제38권2호
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• pp.165-168
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• 2006

분석이 번거로웠던 현미의 총 식이섬유(TDF) 함량을 신속하면서도 친 환경적인 비파괴 분석방법인 FT-NIRS를 이용하여 예측 모델을 개발하였다. 현미는 국내산으로 전남 지방에서 재배된 47개 품종(516개 시료)에 대해서 AOAC 방법에 준한 효소법에 의해 각 측정 시료별 TDF 함량을 분석하였다. 습식 분석된 TDF 함량의 분석오차범위는 0.17-0.72% 이었다. FT.NIRS로 측정된 스렉트럼의 검량식은 빛의 산란 효과를 최소화하기 위해 수학적 처리를 하였고, 몇 개의 특정 파장이 아닌 전 파장 영역(1,000-2,500nm)에 대해서 PLS법으로 작성하였다 회귀분석과 검량식은 NIRCal chemometric software에 의해 작성되었다. 얻어진 검량식의 정확도는 상관계수(r), SEE 및 SEP로 확인하였다. 현미 중 총 식이섬유 함량에 대한 회귀분석을 행한 결과, 상관계수는 0.9780, SEE는 0.0636, SEP는 0.0642로 측정 정확도가 우수함으로 현장 적용을 위한 실용화도 가능할 것으로 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.165-170
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• 2006

Objectives : The determination of oxalate in urine is required for the diagnosis and treatment of primary hyperoxaluria, idiopathic stone disease and various intestinal diseases. We examined the possibility of using Fourier transform near-infrared (FT-NIR) spectroscopy analysis to quantitate urinary oxalate. The practical advantages of this method include ease of the sample preparation and operation technique, the absence of sample pre-treatments, rapid determination and noninvasiveness. Methods : The range of oxalate concentration in standard urine solutions was $0-221mg/{\ell}$. These 80 different samples were scanned in the region of 780-1,300 nm with a 0.5 nm data interval by a Spectrum One NTS FT-NIR spectrometer. PCR, PLSR and MLR regression models were used to calculate and evaluate the calibration equation. Results : The PCR and PLSR calibration models were obtained from the spectral data and they are exactly same. The standard error of estimation (SEE) and the % variance were $10.34mg/{\ell}$ and 97.86%, respectively. After full cross validation of this model, the standard error of estimation was $5,287mg/{\ell}$, which was much smaller than that of the pre-validation. Furthermore, the MCC (multiple correlation coefficient) was 0.998, which was compatible with the 0.923 or 0.999 obtained from the previous enzymatic methods. Conclusions : These results showed that FT-NIR spectroscopy can be used for rapid determination of the concentration of oxalate in human urine samples.

• 마이크로전자및패키징학회지
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• 제26권1호
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• pp.23-28
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• 2019

타이타니아 ($TiO_2$)는 독성이 없고 매우 높은 굴절률, 촉매 활성 및 생체 적합성을 지니고 있으며 화학적 안정성이 있고 높은 이방성을 갖는 저렴한 재료로써 다양한 분야에서 각광받고 있는 세라믹 소재이다. 이러한 $TiO_2$를 sol-gel법을 이용하여 나노입자화 하였다. 나노입자 형성중에 pH를 조절하여 $TiO_2$의 결정성을 제어하였다. 합성된 나노입자는 엑스선 회절분석법, 퓨리에 분광기(Fourier transform infrared), 전계방사형 주사전자현미경(field emission scanning electron microscopy)과 포토루미네선스(photoluminescence spectroscopy)를 이용하여 분석하였다. 합성된 $TiO_2$ 나노입자는 5 nm 이하의 크기를 갖는 것을 확인하였다. 나노입자의 결정성이 증가됨에 따라 550 nm 영역의 발광세기가 증가함을 확인하였다. 이러한 결과로 $TiO_2$ 나노입자의 결정성 조절을 통한 발광 특성 조절을 기대할 수 있다.

• 농업과학연구
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• 제46권2호
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• pp.257-271
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• 2019

The use of food grade hexane (FGH) for edible oil extraction is responsible for the presence of benzene in the crude oil. Benzene is a Group 1 carcinogen and could pose a serious threat to the health of consumer. However, its detection still depends on classical methods using chromatography which requires a rapid non-destructive detection method. Hence, the aim of this study was to investigate the feasibility of using Fourier transform infrared (FTIR) spectroscopy combined with multivariate analysis to detect and quantify the benzene residue in edible oil (sesame and cottonseed oil). Oil samples were adulterated with varying quantities of benzene, and their FTIR spectra were acquired with an attenuated total reflectance (ATR) method. Optimal variables for a partial least-squares regression (PLSR) model were selected using the variable importance in projection (VIP) and the selectivity ratio (SR) methods. The developed PLS models with whole variables and the VIP- and SR-selected variables were validated against an independent data set which resulted in $R^2$ values of 0.95, 0.96, and 0.95 and standard error of prediction (SEP) values of 38.5, 33.7, and 41.7 mg/L, respectively. The proposed technique of FTIR combined with multivariate analysis and variable selection methods can detect benzene residuals in edible oils with the advantages of being fast and simple and thus, can replace the conventional methods used for the same purpose.

• 공업화학
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• 제17권3호
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• pp.291-295
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• 2006

본 연구에서는 아임계 및 초임계 이산화탄소하의 에틸 아세토아세테이트의 케토-에놀 토토머릭 평형상수를 후리에 적외선 분광기를 이용하여 세 가지 다른 온도에서 측정하였다. 케토-에놀 토토머릭 평형상수의 용매에 대한 밀도 의존성을 연구하기 위하여 정온하에서 이산화탄소의 압력을 변화시켰다. 용매인 이산화탄소의 밀도를 증가 시키면, 케토 토토머의 양이 증가하게 되어 케토-에놀 토토머릭 평형상수값이 감소한다. 에틸 아세토아세테이트의 케토-에놀 토토머릭 평형상수의 밀도의존성을 연구하기 위하여 변형된 격자유체수소결합 모델을 적용하였다.

• Advances in nano research
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• 제13권5호
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• pp.437-451
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• 2022

Synthesis approaches usually affect the physical and chemical properties of ferrites. This helps ferrite materials to design them for desired applications. Some of these methods are mechanical milling, ultrasonic method, micro-emulsion, co-precipitation, thermal decomposition, hydrothermal, microwave-assisted, sol-gel, etc. These methods are extensively reviewed by taking example of ZnFe₂O₄. These methods also affect the microstructure and local structure of ferrite which ultimately affect the physical and chemical properties of ferrites. Various spectroscopic techniques such as Raman spectroscopy, Fourier Transform Infrared spectroscopy, Ultra Violet-Visible spectroscopy, Mossbauer spectroscopy, extended x-ray absorption fine structure, and electron paramagnetic resonance are found helpful to reveal this information. Hence, the basic principle and the usefulness of these techniques to find out appropriate information in ZnFe₂O₄ nanoparticles is elaborated in this review.

• Food Science and Biotechnology
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• 제18권2호
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• pp.546-551
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• 2009

The objective of this study was to investigate Fourier transform infrared (FT-IR) spectrometry and the X-ray diffraction (XRD) characterization of melanoidins formed from glucose and fructose with amino acid enantiomers in the Maillard reaction. Before dialysis, FT-IR spectroscopy of all the samples showed that the characteristic absorption intensities appeared as a broad and intense band of the stretching vibration of the -OH group at 3,400/cm for a high pH. The absorption bands of the melanoidins sharply decreased in intensity after dialysis as compared to those before dialysis. In particular, the absorption bands at 992 and 575/cm disappeared. The XRD confirmed that the crystal structure of the melanoidins disappeared after dialysis and a new crystal structure was formed at 9 and $28^{\circ}$ ($2{\theta}$. In particular, broad diffraction peaks were formed in the $10-21^{\circ}$ ($2{\theta}$) range for a high pH, while other sharp diffraction peaks disappeared.

• 공업화학
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• 제16권4호
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• pp.542-548
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• 2005

몇 가지 금속 산화물에 플루오르르 치환된 카르복시산의 자기조립박막을 제조하였다. 사슬 길이의 영향을 비교하기 위하여 퍼플루오르도테칸 산과 퍼플루오르옥타데칸 산을 사용하였다. 사용된 금속 산화물은 알루미나, 탄탈리아, 티타니아, 지르코니아였다. 자기조립박막의 형성은 DRIFT (Diffuse Reflectance Infrared Fourier Transform) 분광법으로 확인하였다. 퍼플루오르탄화수소는 소수성을 가지므로 형성된 자기조립박막도 소수성을 지닐 것으로 예측된다. 형성된 자기조립박막의 DRIFT 스펙트럼의 품질은 금속산화물의 성분 원소뿐만 아니라 분말으 크기에 따라서도 달라졌다.

• 한국세라믹학회지
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• 제52권2호
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• pp.128-132
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• 2015

In this study, we prepared cadmium phosphate glasses with various compositions, given by $xCdO-(100-x)P_2O_5$ (x = 10-55 mol%), and analyzed their Fourier transform infrared spectra, dissolution rate, thermal expansion coefficient, glass transition temperature, glass softening temperature, and optical band gap. We found that the thermal expansion coefficient and dissolution rate increased while the glass transition temperature and glass softening temperature decreased with increasing CdO content. These results suggest that CdO acts as a network modifier in binary phosphate glass and weakens its structure.