• Title/Summary/Keyword: self-limiting

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Desalting of tobacco extract using electrodialysis

  • Ge, Shaolin;Li, Wei;Zhang, Zhao;Li, Chuanrun;Wang, Yaoming
    • Membrane and Water Treatment
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    • v.7 no.4
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    • pp.341-353
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    • 2016
  • Papermaking reconstituted tobacco is an important strategy for recycling the waste tobacco residues. To indentify the influences of the inorganic components on harmful components delivery in cigarette smoke, a self-made electrodialysis stack was assembled to desalt the tobacco extract. The influences of the applied current and extract content on the removal rate of the inorganic ions were investigated. Results indicated that the applied current was a dominant impact on the desalination performance. High currents lower than the limiting current density could accelerate the desalting efficiency but cause higher energy consumption. A current of 2 A, or current density of ${\sim}11mA{\cdot}cm^{-2}$, was an optimal choice by considering both the energy consumption and desalting efficiency. A 20% tobacco extract was an appropriate content for the electrodialysis process. More than 90% of inorganic ions could be removed under the optimum condition. The preliminary result indicated that removal of inorganic components was beneficial to decrease the harmful component delivery in cigarette smoke. Naturally, ED is an environmentally friendly and high-effective technology for desalting the tobacco extract.

Inhibition of Herpes Simplex Viruses, Types 1 and 2, by Ginsenoside 20(S)-Rg3

  • Wright, Stephen M.;Altman, Elliot
    • Journal of Microbiology and Biotechnology
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    • v.30 no.1
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    • pp.101-108
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    • 2020
  • Infections by herpes simplex viruses have an immense impact on humans, ranging from self-limiting, benign illness to serious, life-threatening diseases. While nucleoside analog drugs are available, resistance has been increasing and currently no vaccine exists. Ginsenosides derived from Panax ginseng have been documented to inhibit several viruses and bolster immune defenses. This study evaluated 12 of the most relevant ginsenosides from P. ginseng for toxicities and inhibition of herpes simplex viruses types 1 and 2 in Vero cells. The effects of test compounds and virus infection were determined using a PrestoBlue cell viability assay. Time course studies were also conducted to better understand at what points the virus life cycle was affected. Non-toxic concentrations of the ginsenosides were determined and ranged from 12.5 μM to greater than 100 μM. Ginsenoside 20(S)-Rg3 demonstrated the greatest inhibitory effect and was active against both HSV-1 and HSV-2 with an IC50 of approximately 35 μM. The most dramatic inhibition-over 100% compared to controls-occurred when the virus was exposed to 20(S)-Rg3 for 4 h prior to being added to cells. 20(S)-Rg3 holds promise as a potential chemotherapeutic agent against herpes simplex viruses and, when used together with valacyclovir, may prevent increased resistance to drugs.

Cause analysis, prevention, and treatment of postoperative restlessness after general anesthesia in children with cleft palate

  • Xu, Hao;Mei, Xiao-Peng;Xu, Li-Xian
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.17 no.1
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    • pp.13-20
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    • 2017
  • Cleft palate is one of the most common congenital malformations of the oral and maxillofacial region, with an incidence rate of around 0.1%. Early surgical repair is the only method for treatment of a cleft lip and palate. However, because of the use of inhalation anesthesia in children and the physiological characteristics of the cleft palate itself combined with the particularities of cleft palate surgery, the incidence rate of postoperative emergence agitation (EA) in cleft palate surgery is significantly higher than in other types of interventions. The exact mechanism of EA is still unclear. Although restlessness after general anesthesia in children with cleft palate is self-limiting, its effects should be considered by clinicians. In this paper, the related literature on restlessness after surgery involving general anesthesia in recent years is summarized. This paper focuses on induction factors as well as prevention and treatment of postoperative restlessness in children with cleft palate after general anesthesia. The corresponding countermeasures to guide clinical practice are also presented in this paper.

Autoimmune hepatitis and thyroiditis associated with antituberculous medications : A case report (항결핵약으로 유발되고 갑상선염이 동반된 자가면역간염 1례)

  • Yu, Seong Keun;Kim, Sara;Moon, Jin Soo;Kim, Han Seong
    • Clinical and Experimental Pediatrics
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    • v.51 no.5
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    • pp.528-532
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    • 2008
  • Drug-induced toxic hepatitis is a relatively common hepatic disease in children, and it is usually self-limiting upon cessation of the offending drugs. Antituberculous drugs are well known for inducing hepatitis. Some cases of drug-induced hepatitis with autoimmune features have been reported; in these cases, the offending drugs were usually methyldopa, nitrofurantoin, minocycline, and interferon. The authors report the first case in Korea of drug-induced autoimmune hepatitis associated with thyroiditis and multiple autoantibodies that was induced by the antituberculous drugs isoniazid and rifampin.

Visualization of Gene Transfer into Live Cells Using Fluorescent Semiconductor Nanocrystals

  • Kim Jung Kyung;Lim Sun Hee;Lee Yongku;Shin Young Shik;Chung Chanil;Chang Jun Keun;Yoo Jung Yul
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.81-82
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    • 2003
  • We have developed the method for the conjugation of biotinylated DNA to streptavidin-coated QDs. QD-DNA conjugates and a high-sensitive fluorescence imaging technique are adopted to visualize gene transport across the membrane of the live cell in real time. Endocytotic cellular uptake of oligonucleotide and electrically-mediated plasmid DNA transfer into the live cell are monitored by a quantitative microscopic imaging system. Long-term kinetic study enables us to reveal the unknown mechanisms and rate-limiting steps of extracellular and intracellular transport of biomolecules. We designed experimental protocols to conjugate the oligonucleotide or the plasmid DNA to commercially available streptavidin-coated QDs. Gel electrophoresis is used to verify the effect of incubation time and the molar ratio of QDs and DNA on the conjugation efficiency. It is possible to fractionate the QD-DNA conjugates according to the DNA concentration and obtain the purified conjugates by a gel extraction technique.

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Two Cases of Neurotoxin Tetramine Poisoning Following Ingestion of Buccinum Striatissinum (물레고동 섭취 후 발생한 테트라민 중독 2례)

  • Kim, So Eun;Lee, Jae Baek;Jin, Young Ho;Yoon, Jae Chol;Jo, Si On;Lee, Jeong Moon;Jeong, Tae Oh
    • Journal of The Korean Society of Clinical Toxicology
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    • v.14 no.1
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    • pp.66-69
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    • 2016
  • Some carnivorous gastropods have heat stable tetramine toxins in their salivary glands. This toxin is an autonomic ganglionic blocking agent that enables them to catch the prey easily by paralyzing their targets. Acute tetramine toxin poisoning in humans from eating whelks has been well described based on numerous cases, but is rare in Korea. Symptoms of tetramine poisoning include eyeball pain, blurred vision, headache, dizziness, muscular twitching, tingling of hands and feet, weakness, paralysis and sometimes collapse. Gastrointestinal symptoms, such as abdominal pain, nausea, and vomiting can also occur. However, intoxication is self-limiting and patients will usually recover in about 24 hours. Herein, we report 2 cases of tetramine poisoning after ingestion of Buccinum striatissinum as meat and soup.

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New Measurement Technique of Expiratory Air Flow Rate Using Miniatured Air Chamber (소형 공기챔버를 센서소자로 사용하는 새로운 호식기류 계측기술)

  • Kim, Kyung-Ah;Lee, Jae-Hun;Kim, Goon-Jin;Lee, Tae-Soo;Cha, Eun-Jong
    • Journal of Sensor Science and Technology
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    • v.13 no.2
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    • pp.79-84
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    • 2004
  • Asthma is one of the important respiratory diseases requiring home self care usually performed by commercialized peak expiratory flow meter (PEFM). However, this simple device can measure only single parameter, PEF, due to its purely mechanical principle, significantly limiting desease management quality. The present study introduced a new expiratory flow measurement technique by miniatured air expansion chamber easily installed within PEFM. Continuous pressure signal obtained from the chamber demonstrated an accurate quadratic relationship with flow. The volume measurement error was $<{\pm}1%$ well within the American Thoracic Society (ATS) criteria of 3%. Important spirometric parameters of FVC, PEF, and FEF25-75% were all accurately estimated with correlation coefficients > 0.95. The present technique obtains continuous expiratory air flow signal, making possible and convenient to perform spirometric test at home. Electronic interface capability would be also useful for remote asthma management.

Density Functional Theory Study of Silicon Chlorides for Atomic Layer Deposition of Silicon Nitride Thin Films

  • Yusup, Luchana L.;Woo, Sung-Joo;Park, Jae-Min;Lee, Won-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.211.1-211.1
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    • 2014
  • Recently, the scaling of conventional planar NAND flash devices is facing its limits by decreasing numbers of electron stored in the floating gate and increasing difficulties in patterning. Three-dimensional vertical NAND devices have been proposed to overcome these issues. Atomic layer deposition (ALD) is the most promising method to deposit charge trap layer of vertical NAND devices, SiN, with excellent quality due to not only its self-limiting growth characteristics but also low process temperature. ALD of silicon nitride were studied using NH3 and silicon chloride precursors, such as SiCl4[1], SiH2Cl2[2], Si2Cl6[3], and Si3Cl8. However, the reaction mechanism of ALD silicon nitride process was rarely reported. In the present study, we used density functional theory (DFT) method to calculate the reaction of silicon chloride precursors with a silicon nitride surface. DFT is a quantum mechanical modeling method to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. The bond dissociation energy of each precursor was calculated and compared with each other. The different reactivities of silicon chlorides precursors were discussed using the calculated results.

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Application of Atomic Layer Deposition to Solid Oxide Fuel Cells

  • Kim, Eui-Hyun;Ko, Myeong-Hee;Hwang, Hee-Soo;Hwang, Jin-ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.478.2-478.2
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    • 2014
  • Atomic layer deposition (ALD) provides self-limiting processes based on chemisorption-based reactions. Such unique features allow for superior step coverage, atomic-scale control in thickness, and surface-dependent reaction controls. Furthermore, the surface-limited deposition enables the artificial deposition of oxide and/or metallic materials onto the porous systems as long as the supply is guaranteed in terms of time in providing reactant species and removing the byproducts and redundant reactants. The unique feature of atomic layer deposition is applied to solid oxide fuel cells whose incorporates two porous cathode and anode compartments in addition to the ionic electrolyte. Specific materials are deposited to the surface sites of porous electrodes, with the aim to controlling the triple phase boundaries crucial for the optimized SOFC performances. The effect of ALD on the SOFC performance is characterized using current-voltage characteristics in addition to frequency-dependent impedance spectroscopy. The pros and cons of ALD-controlled SOFCs are discussed toward high-performance SOFC systems.

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Study on Cone Type Thresher (I) (원추형(圓錐型) 탈곡기(脱糓機)에 관(關)한 연구(硏究))

  • Lee, Seung Kyu
    • Journal of Biosystems Engineering
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    • v.6 no.1
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    • pp.48-59
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    • 1981
  • The major limiting factor on the determination of combine capacity is the frequent occurence of clogging over the some parts of machine when the crop is wet in the case of Japanese self-feeding type combine. And in the case of American conventional combine having big separating parts, the great grain loss and damage occur when the machine is used for rice harvesting. This experiment was carried out to develop the new type threshing and separating equipment. Proto-type thresher which consist of a conical threshing drum and a conical separating sieve rotating around the threshing cone was constructed and tested. In the case of 800 rpm of threshing cone speed, average threshing loss was below 1 percent, separating loss was about 1 percent, grain damage was about 0.4 percent, and average total power required was about 2.6 PS. This design has some problems such as higher power required or wrapping problems under the conditions of feeding long damp straw. But, compared with the conventional combine or thresher, this machine certainly has some potentials for this approach to combine development. The crop feed rate must be increased through improvement of the feeding portion of the threshing cone. And it is required to investigate further about some parameters causing wrapping phenomena.

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