• Title/Summary/Keyword: Free Si

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Bacterial contamination levels in strawberry parts according to their cultivation methods (재배방식에 따른 딸기의 부위별 세균 오염도 분석)

  • Yu, Yong-Man;Kim, Jin-Won;Choi, In-Wook;Youn, Young-Nam;Lee, Young-Ha
    • Food Science and Preservation
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    • v.20 no.3
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    • pp.323-329
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    • 2013
  • Strawberries are among the leading ready-to-eat agricultural products that have superior taste and nutrition. Thus, consumer concerns about the safety of eating strawberries are growing. To evaluate the contamination levels of strawberries according to their cultivation methods (nutriculture, pesticide-free culture and organic farming) and parts [fruit (flesh), stalk (pedunle) and leaf (calyx)], 1,020 parts of strawberry samples were collected at 12 farms in Nonsan-si and quantitatively or qualitatively examined for the indicators of food safety and food poisoning bacteria. The total aerobic bacteria count in the whole samples was 2.3~6.8 ${\log}_{10}$ CFU/g, and coliform bacteria were detected in 14.2% of the whole samples with a contamination level range of 2.1~4.5 log CFU/g. E. coli were detected in 0.9% of the whole samples with a contamination level range of 2.1~2.8 log CFU/g. The analysis of the bacterial levels according to the cultivation methods showed that the total aerobic bacteria and coliform counts were higher in the strawberries that were grown via organic farming than in those that were grown via nutriculture and pesticide-free culture. However, the E. coli counts of the strawberries that were grown via organic farming and via pesticide-free culture were similar and differed from that of the strawberries that were grown via nutriculture. The analysis of the contamination levels according to the parts of the strawberries showed that the total aerobic bacteria, coliform and E. coli counts of the fruits, stalks and leaves of the strawberries did not significantly differ. Staphylococcus aureus was detected in two organically grown strawberries, but Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected in the whole samples. These results show that the bacterial contamination levels of the strawberries differed based on their cultivation methods. Thus, a suitable method of reducing the bacterial contamination levels of strawberries according to their farming methods is needed.

Dynamical Study on the Blasting with One-Free-Face to Utilize AN-FO Explosives (초유폭약류(硝油爆藥類)를 활용(活用)한 단일자유면발파(單一自由面發破)의 역학적(力學的) 연구(硏究))

  • Huh, Ginn
    • Economic and Environmental Geology
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    • v.5 no.4
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    • pp.187-209
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    • 1972
  • Drilling position is one of the most important factors affecting on the blasting effects. There has been many reports on several blasting factors of burn-cut by Messrs. Brown and Cook, but in this study the author tried to compare drilling positions of burn-cut to pyramid-cut, and also to correlate burn-cut effects of drilling patterns, not being dealt by Prof. Ito in his theory, which emphasized on dynamical stress analysis between explosion and free face. According to former theories, there break out additional tensile stress reflected at the free face supplemented to primary compressive stress on the blasting with one-free-face. But with these experimented new drilling patterns of burn-cut, more free faces and nearer distance of each drilling holes make blasting effects greater than any other methods. To promote the above explosive effect rationary, it has to be considered two important categories under-mentioned. First, unloaded hole in the key holes should be drilled in wider diameter possibly so that it breaks out greater stress relief. Second, key holes possibly should have closer distances each other to result clean blasting. These two important factors derived from experiments with, theories of that the larger the dia of the unloaded hole, it can be allowed wider secondary free faces and closes distances of each holes make more developed stress relief, between loaded and unloaded holes. It was suggested that most ideal distance between holes is about 4 clearance in U. S. A., but the author, according to the experiments, it results that the less distance allow, the more effective blasting with increased broken rock volume and longer drifted length can be accomplished. Developed large hole burn-cut method aimed to increase drifting length technically under the above considerations, and progressive success resulted to achieve maximum 7 blasting cycles per day with 3.1m drifting length per cycle. This achievement originated high-speed-drifting works, and it was also proven that application of Metallic AN-FO on large hole burn-cut method overcomes resistance of one-free-face. AN-FO which was favored with low price and safety handling is the mixture of the fertilizer or industrial Ammonium-Nitrate and fuel oil, and it is also experienced that it shows insensible property before the initiation, but once it is initiated by the booster, it has equal explosive power of Ammonium Nitrate Explosives (ANE). There was many reports about AN-FO. On AN-FO mixing ratio, according to these experiments, prowdered AN-FO, 93.5 : 6.5 and prilled AN-FO 94 : 6, are the best ratios. Detonation, shock, and friction sensities are all more insensitive than any other explosives. Residual gas is not toxic, too. On initation and propagation of the detonation test, prilled AN-FO is more effective than powered AN-FO. AN-FO has the best explosion power at 7 days elapsed after it has mixed. While AN-FO was used at open pit in past years prior to other conditions, the author developed new improved explosives, Metallic AN-FO and Underwater explosive, based on the experiments of these fundmental characteristics by study on its usage utilizing AN-FO. Metallic AN-FO is the mixture of AN-FO and Al, Fe-Si powder, and Underwater explosive is made from usual explosive and AN-FO. The explanations about them are described in the other paper. In this study, it is confirmed that the blasting effects of utilizing AN-FO explosives are very good.

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The improvement of ginsenoside accumulation in Panax ginseng as a result of γ-irradiation

  • Kim, Dong Sub;Song, Mira;Kim, Sun-Hee;Jang, Duk-Soo;Kim, Jin-Baek;Ha, Bo-Keun;Kim, Sang Hoon;Lee, Kyung Jun;Kang, Si-Yong;Jeong, Il Yun
    • Journal of Ginseng Research
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    • v.37 no.3
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    • pp.332-340
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    • 2013
  • In this study, gamma rays were used to irradiate embryogenic calli induced from cotyledon explants of Panax ginseng Meyer. After the embryogenic calli were irradiated, they were transferred to adventitious roots using an induction medium; next, mutated adventitious root (MAR) lines with a high frequency of adventitious root formations were selected. Two MAR lines (MAR 5-2 and MAR 5-9) from the calli treated with 50 Gy of gamma rays were cultured on an $NH_4NO_3$-free Murashige and Skoog medium with indole-3-butyric acid 3 mg/L. The expression of genes related to ginsenoside biosynthesis was analyzed using reverse transcription polymerase chain reaction with RNA prepared from native ginseng (NG), non-irradiated adventitious root (NAR) and 2 MAR lines. The expression of the squalene epoxidase and dammarenediol synthase genes was increased in the MAR 5-2 line, whereas the phytosterol synthase was increased in the MAR 5-9 line. The content and pattern of major ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1) were analyzed in the NG, NAR, and 2 MAR lines (MAR 5-2 and MAR 5-9) using TLC and HPLC. In the TLC analysis, the ginsenoside patterns in the NG, NAR, and 2 MAR lines were similar; in contrast, the MAR 5-9 line showed strong bands of primary ginsenosides. In the HPLC analysis, compared with the NG, one new type of ginsenoside was observed in the NAR and 2 MAR lines, and another new type of ginsenoside was observed in the 2 MAR lines irradiated with gamma rays. The ginsenoside content of the MAR 5-9 line was significantly greater in comparison to the NG.

High Performance Flexible Inorganic Electronic Systems

  • Park, Gwi-Il;Lee, Geon-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.115-116
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    • 2012
  • The demand for flexible electronic systems such as wearable computers, E-paper, and flexible displays has increased due to their advantages of excellent portability, conformal contact with curved surfaces, light weight, and human friendly interfaces over present rigid electronic systems. This seminar introduces three recent progresses that can extend the application of high performance flexible inorganic electronics. The first part of this seminar will introduce a RRAM with a one transistor-one memristor (1T-1M) arrays on flexible substrates. Flexible memory is an essential part of electronics for data processing, storage, and radio frequency (RF) communication and thus a key element to realize such flexible electronic systems. Although several emerging memory technologies, including resistive switching memory, have been proposed, the cell-to-cell interference issue has to be overcome for flexible and high performance nonvolatile memory applications. The cell-to-cell interference between neighbouring memory cells occurs due to leakage current paths through adjacent low resistance state cells and induces not only unnecessary power consumption but also a misreading problem, a fatal obstacle in memory operation. To fabricate a fully functional flexible memory and prevent these unwanted effects, we integrated high performance flexible single crystal silicon transistors with an amorphous titanium oxide (a-TiO2) based memristor to control the logic state of memory. The $8{\times}8$ NOR type 1T-1M RRAM demonstrated the first random access memory operation on flexible substrates by controlling each memory unit cell independently. The second part of the seminar will discuss the flexible GaN LED on LCP substrates for implantable biosensor. Inorganic III-V light emitting diodes (LEDs) have superior characteristics, such as long-term stability, high efficiency, and strong brightness compared to conventional incandescent lamps and OLED. However, due to the brittle property of bulk inorganic semiconductor materials, III-V LED limits its applications in the field of high performance flexible electronics. This seminar introduces the first flexible and implantable GaN LED on plastic substrates that is transferred from bulk GaN on Si substrates. The superb properties of the flexible GaN thin film in terms of its wide band gap and high efficiency enable the dramatic extension of not only consumer electronic applications but also the biosensing scale. The flexible white LEDs are demonstrated for the feasibility of using a white light source for future flexible BLU devices. Finally a water-resist and a biocompatible PTFE-coated flexible LED biosensor can detect PSA at a detection limit of 1 ng/mL. These results show that the nitride-based flexible LED can be used as the future flexible display technology and a type of implantable LED biosensor for a therapy tool. The final part of this seminar will introduce a highly efficient and printable BaTiO3 thin film nanogenerator on plastic substrates. Energy harvesting technologies converting external biomechanical energy sources (such as heart beat, blood flow, muscle stretching and animal movements) into electrical energy is recently a highly demanding issue in the materials science community. Herein, we describe procedure suitable for generating and printing a lead-free microstructured BaTiO3 thin film nanogenerator on plastic substrates to overcome limitations appeared in conventional flexible ferroelectric devices. Flexible BaTiO3 thin film nanogenerator was fabricated and the piezoelectric properties and mechanically stability of ferroelectric devices were characterized. From the results, we demonstrate the highly efficient and stable performance of BaTiO3 thin film nanogenerator.

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A Dual-Channel 6b 1GS/s 0.18um CMOS ADC for Ultra Wide-Band Communication Systems (초광대역 통신시스템 응용을 위한 이중채널 6b 1GS/s 0.18um CMOS ADC)

  • Cho, Young-Jae;Yoo, Si-Wook;Kim, Young-Lok;Lee, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.12 s.354
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    • pp.47-54
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    • 2006
  • This work proposes a dual-channel 6b 1GS/s ADC for ultra wide-band communication system applications. The proposed ADC based on a 6b interpolated flash architecture employs wide-band open-loop track-and-hold amplifiers, comparators with a wide-range differential difference pre-amplifier, latches with reduced kickback noise, on-chip CMOS references, and digital bubble-code correction circuits to optimize power, chip area, and accuracy at 1GS/s. The ADC implemented in a 0.18um 1P6M CMOS technology shows a signal-to-noise-and-distortion ratio of 30dB and a spurious-free dynamic range of 39dB at 1GS/s. The measured differential and integral non-linearities of the prototype ADC are within 1.0LSB and 1.3LSB, respectively. The dual-channel ADC has an active area of $4.0mm^2$ and consumes 594mW at 1GS/s and 1.8V.

Distinctions Between Clinicopathological Factors and Prognosis of Alpha-fetoprotein Negative and Positive Hepatocelluar Carcinoma Patients

  • Xu, Jia;Liu, Chang;Zhou, Lei;Tian, Feng;Tai, Ming-Hui;Wei, Ji-Chao;Qu, Kai;Meng, Fan-Di;Zhang, Ling-Qiang;Wang, Zhi-Xin;Zhang, Jing-Yao;Chang, Hu-Lin;Liu, Si-Nan;Xu, Xin-Shen;Song, Yan-Zhou;Liu, Jun;Zhang, Peng
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.2
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    • pp.559-562
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    • 2012
  • Serum alpha-fetoprotein (AFP) is a significant marker for clinical diagnosis and prognosis evaluation in hepatocellular carcinoma (HCC) patients. However, some proportion of liver cancer patients are AFP-negative (AFP ${\leq}$20ng/ml). In order to study the differences between clinicopathological factors and prognosis of alpha-fetoprotein negative and positive patients, a total of 114 cases (41 AFP-negative and 73 AFP-positive) were selected for our research. By systematically statistical analysis, the results demonstrated that compared with AFP-negative patients, AFP-positive examples were more likely to feature cirrhosis nodules, non-complete neoplasm capsules, and a poor Edmondson-steiner grade. Furthermore, AFP-negative patients demonstrated a favorable long-term prognosis. By univariate analysis and multivariate analysis with Cox's proportional hazards model, multiple tumors were found to be independent risk factors for worse survival of AFP negative patients; however, less tumor-free margins, multiple tumors and Edmondson-steiner grades III/IV, proved to be independent risk factors leading to a poor prognosis of AFP positive cases. Finally, we can infer that high levels of AFP signify a highly malignant tumor and unfavorable prognosis.

Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea

  • Chai, Jong-Yil;Park, Jae-Hwan;Jung, Bong-Kwang;Guk, Sang-Mee;Kim, Jae-Lip;Shin, Eun-Hee;Klein, Terry A.;Kim, Heung-Chul;Chong, Sung-Tae;Baek, Luck-Ju;Song, Jin-Won
    • Parasites, Hosts and Diseases
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    • v.47 no.3
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    • pp.311-314
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    • 2009
  • A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n= 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Effect of 4-hexylresorcinol on Blood Coagulation and Healing of Injured Vessel in a Rat Model

  • Park, Yong-Tae;Park, Si-Yeok;Kim, Min-Keun;Kim, Seong-Gon;Park, Young-Wook;Kwon, Kwang-Jun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.35 no.5
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    • pp.284-293
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    • 2013
  • Purpose: For reconstruction of craniomaxillofacial defects caused by tumor, trauma, infection etc, free flap transplantation with microvascular surgery is a very useful method. Thrombus formation at the anastomosis site is the major cause of graft failure. 4-Hexylresorcinol (4-HR) is generally known as an antiseptic and antiparasitic agent. This study was conducted in order to evaluate the effect of 4-HR on blood coagulation in vitro. In addition, we investigated thrombus formation and endothelial repair of an injured vessel in an animal model. Methods: In the in vitro experiment, we compared blood coagulation time between the 4-HR treated group and normal blood. Thirty rats were used for in vivo animal experiments. After exposure of the right femoral vein, a micro vessel clamp was placed and the femoral vein was intentionally cut. Microvascular anastomosis was performed on all rats using 10-0 nylon under microscopy. The animals were divided into two groups. In the experimental group (n=15), 4-HR (250 mg/kg) mixed with olive oil (10 mL/kg) was administered per os daily. Animals in the control group (n=15) were given olive oil only. The animals were sacrificed at three days, seven days, and fourteen days after surgery and rat femoral vein samples were taken. Vascular patency and thrombus formation were investigated just before sacrifice. Histologic analysis was performed under a microscope. Results: Results of an in vitro blood coagulation test showed that coagulation time was delayed in the 4-HR treated group. The results obtained from an in vivo 4-HR administered rat model showed that the patency of all experimental groups was better at thirty minutes, seven days, and fourteen days after microvascular anastomosis than that of the control group at seven and fourteen days after anastomosis, and the amount of thrombus in the experimental groups was much less than that of the control group. Endothelial repair was observed in the histologic analysis. Conclusion: Findings of this study demonstrated that blood coagulation was delayed in the vitro 4-HR treated group. In addition, good vascular patency, anti-thrombotic effect, and repair of venous endothelial cells were observed in the vivo 4-HR administered rat group.

Fermentation Process for Odor Removal of Oyster (Crassostrea gigas) Hydrolysate and Its Properties (이취 제거를 위한 굴 가수분해물의 발효공정과 제품의 특성)

  • Lee, Su-Seon;Park, Si-Hyang;Kim, Hyeun-A;Choi, Yeung-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.4
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    • pp.542-550
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    • 2016
  • This study was carried out to investigate the optimal processing conditions for odor removal and maximal antioxidant effects of oyster (Crassostrea gigas) hydrolysate. The optimal hydrolysis conditions were 3.3% neutrase as the protease, $50^{\circ}C$ as the hydrolysis temperature, and 8.3 h as the hydrolysis time. Fish odor of enzymatic oyster hydrolysate was greatly reduced during Saccharomyces cerevisiae fermentation at $24^{\circ}C$ with 0.5% glucose. The protein content of the fermentation product from oyster hydrolysate powder was 25.7%, which contained the major amino acids Glu, Asp, Lys, Arg, Gly, and Ala, whereas Leu, Ala, Phe, Val, and Tau were abundant free amino acids. The important minor minerals were Zn and Fe. Toxicity against Chang cells was not observed in the fermentation product from the oyster hydrolysate up to $200{\mu}g/mL$. The results suggest that fermentation with S. cerevisiae could reduce the fish odor of enzymatic oyster hydrolysate. The hydrolysate has potential application as a food ingredients and nutraceutical.

Differentiation of Barley Response to Drought and Salt Stress in Antioxidant Enzyme Activity and Free Amino Acid Content (염해 및 한발에 대한 보리의 생화학적 반응 - 항산화효소 활성 및 아미노산 함량의 변화)

  • Kim, Dea-Wook;Heo, Hwa-Young;Suh, Sae-Jung;Lee, Yeong-Ho;Kim, Si-Ju
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.133-138
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    • 2006
  • To differentiate barley responses to drought and salt stress, barley seedlings at the second leaf stage were treated with 218 mM NaCl and 29.5% PEG6000 iso-osmotic to 218 mM NaCl for 6 days. Shoot fresh weight and leaf relative water content of barley seedlings were more reduced by drought compared to salt stress. Hydrogen peroxide content increased under both stress conditions, but its accumulation was more severe at 6 days after salt stress. The activity of ascorbate peroxidase, glutathione reductase (GR) and catalase (CAT) was enhanced until 4 days after salt stress. On the other hand, the activity of GR and CAT increased gradually until 6 days after drought. Among the amino acids measured in this study, the accumulation of glycine, arginine and GABA (${\gamma}-aminobutyric$ acid) was lower under salt stress than drought. However, considerably larger amount of proline was accumulated by salt stress. It is concluded that the antioxidant enzymes activity and amino acid content of barley seed-lings were differently regulated in response to the isoosmotic condition of salt and drought stress.