• Title/Summary/Keyword: Neutralization tests

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Strength and durability of concrete in hot spring environments

  • Chen, How-Ji;Yang, Tsung-Yueh;Tang, Chao-Wei
    • Computers and Concrete
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    • v.6 no.4
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    • pp.269-280
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    • 2009
  • In this paper an experimental study of the influence of hot springs curing upon concrete properties was carried out. The primary variables of the investigation include water-to-binder ratio (W/B), pozzolanic material content and curing condition. Three types of hot springs, in the range $40-90^{\circ}C$, derived from different regions in Taiwan were adopted for laboratory testing of concrete curing. In addition, to compare with the laboratory results, compressive strength and durability of practical concrete were conducted in a tunnel construction site. The experimental results indicate that when concrete comprising pozzolanic materials was cured by a hot spring with high temperature, its compressive strength increased rapidly in the early ages due to high temperature and chloride ions. In the later ages, the trend of strength development decreased obviously and the strength was even lower than that of the standard cured one. The results of durability test show that concrete containing 30-40% Portland cement replacement by pozzolanic materials and with W/B lower than 0.5 was cured in a hot spring environment, then it had sufficient durability to prevent steel corrosion. Similar to the laboratory results, the cast-inplace concrete in a hot spring had a compressive strength growing rapidly at the earlier age and slowly at the later age. The results of electric resistance and permeability tests also show that concrete in a hot spring had higher durability than those cured in air. In addition, there was no neutralization reaction being observed after the 360-day neutralization test. This study demonstrates that the concrete with enough compressive strength and durability is suitable for the cast-in-place structure being used in hot spring areas.

Selection and identification of single-domain antibody against Peste des Petits Ruminants virus

  • Liu, Dan;Li, Lingxia;Cao, Xiaoan;Wu, Jinyan;Du, Guoyu;Shang, Youjun
    • Journal of Veterinary Science
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    • v.22 no.4
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    • pp.45.1-45.13
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    • 2021
  • Background: Peste des petits ruminants (PPR) is an infectious disease caused by the peste des petits ruminants virus (PPRV) that mainly produces respiratory symptoms in affected animals, resulting in great losses in the world's agriculture industry every year. Single-domain variable heavy chain (VHH) antibody fragments, also referred to as nanobodies, have high expression yields and other advantages including ease of purification and high solubility. Objectives: The purpose of this study is to obtain a single-domain antibody with good reactivity and high specificity against PPRV. Methods: A VHH cDNA library was established by immunizing camels with PPRV vaccine, and the capacity and diversity of the library were examined. Four PPRV VHHs were selected, and the biological activity and antigen-binding capacity of the four VHHs were identified by western blot, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) analyses. ELISA was used to identify whether the four VHHs were specific for PPRV, and VHH neutralization tests were carried out. ELISA and western blot analyses were used to identify which PPRV protein was targeted by VHH2. Results: The PPRV cDNA library was constructed successfully. The library capacity was greater than 2.0 × 106 cfu/mL, and the inserted fragment size was approximately 400 bp to 2000 bp. The average length of the cDNA library fragment was about 1000 bp, and the recombination rate was approximately 100%. Four single-domain antibody sequences were selected, and proteins expressed in the supernatant were obtained. The four VHHs were shown to have biological activity, close affinity to PPRV, and no cross-reaction with common sheep diseases. All four VHHs had neutralization activity, and VHH2 was specific to the PPRV M protein. Conclusions: The results of this preliminary research of PPRV VHHs showed that four screened VHH antibodies could be useful in future applications. This study provided new materials for inclusion in PPRV research.

Generation of a recombinant rabies virus expressing green fluorescent protein for a virus neutralization antibody assay

  • Yang, Dong-Kun;Kim, Ha-Hyun;Park, Yu-Ri;Yoo, Jae Young;Park, Yeseul;Park, Jungwon;Hyun, Bang-Hun
    • Journal of Veterinary Science
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    • v.22 no.4
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    • pp.56.1-56.10
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    • 2021
  • Background: Fluorescent antibody virus neutralization (FAVN) test is a standard assay for quantifying rabies virus-neutralizing antibody (VNA) in serum. However, a safer rabies virus (RABV) should be used in the FAVN assay. There is a need for a new method that is economical and time-saving by eliminating the immunostaining step. Objectives: We aimed to improve the traditional FAVN method by rescuing and characterizing a new recombinant RABV expressing green fluorescent protein (GFP). Methods: A new recombinant RABV expressing GFP designated as ERAGS-GFP was rescued using a reverse genetic system. Immuno-fluorescence assay, peroxidase-linked assay, electron microscopy and reverse transcription polymerase chain reaction were performed to confirm the recombinant ERAGS-GFP virus as a RABV expressing the GFP gene. The safety of ERAGS-GFP was evaluated in 4-week-old mice. The rabies VNA titers were measured and compared with conventional FAVN and FAVN-GFP tests using VERO cells. Results: The virus propagated in VERO cells was confirmed as RABV expressing GFP. The ERAGS-GFP showed the highest titer (108.0 TCID50/mL) in VERO cells at 5 days post-inoculation, and GFP expression persisted until passage 30. The body weight of 4-week-old mice inoculated intracranially with ERAGS-GFP continued to increase and the survival rate was 100%. In 62 dog sera, the FAVN-GFP result was significantly correlated with that of conventional FAVN (r = 0.95). Conclusions: We constructed ERAGS-GFP, which could replace the challenge virus standard-11 strain used in FAVN test.

Prevalence of feline calicivirus and the distribution of serum neutralizing antibody against isolate strains in cats of Hangzhou, China

  • Zheng, Mengjie;Li, Zesheng;Fu, Xinyu;Lv, Qian;Yang, Yang;Shi, Fushan
    • Journal of Veterinary Science
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    • v.22 no.5
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    • pp.73.1-73.11
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    • 2021
  • Background: Feline calicivirus (FCV) is a common pathogen of felids, and FCV vaccination is regularly practiced. The genetic variability and antigenic diversity of FCV hinder the effective control and prevention of infection by vaccination. Improved knowledge of the epidemiological characteristics of FCV should assist in the development of more effective vaccines. Objectives: This study aims to determine the prevalence of FCV in a population of cats with FCV-suspected clinical signs in Hangzhou and to demonstrate the antigenic and genetic relationships between vaccine status and representative isolated FCV strains. Methods: Cats (n = 516) from Hangzhou were investigated between 2018 and 2020. The association between risk factors and FCV infection was assessed. Phylogenetic analyses based on a capsid coding sequence were performed to identify the genetic relationships between strains. In vitro virus neutralization tests were used to assess antibody levels against isolated FCV strains in client-owned cats. Results: The FCV-positive rate of the examined cats was 43.0%. Risk factors significantly associated with FCV infection were vaccination status and oral symptoms. Phylogenetic analysis revealed a radial phylogeny with no evidence of temporal or countrywide clusters. There was a significant difference in the distribution of serum antibody titers between vaccinated and unvaccinated cats. Conclusions: This study revealed a high prevalence and genetic diversity of FCV in Hangzhou. The results indicate that the efficacy of FCV vaccination is unsatisfactory. More comprehensive and refined vaccination protocols are an urgent and unmet need.

Current Status and Analysis of Durability for Buildings Long Neglected after Construction Discontinuation in Jeju (제주지역 공사중단 건축물의 현황조사 및 내구성 분석)

  • Han, In-Deok;Kim, Doo-Seong;Jang, Myunghoun
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.4
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    • pp.441-452
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    • 2023
  • Buildings that have been long neglected can suffer severe durability reduction due to factors such as rebar rust and concrete quality deterioration resulting from exposure to outside air. Furthermore, the issues associated with these suspended buildings, including safety accidents, social crimes, and environmental pollution, are becoming increasingly serious. This study investigates the current status of these buildings in the Jeju area, identifies the problems, and examines the durability of the structure in a specific location to assess the possibility of future use. Aesthetic surveys(visual and slope inspections) as well as non-destructive tests(compressive strength tests, neutralization tests, and rebar detection tests) were conducted to assess durability. The analysis revealed that the structure maintained satisfactory durability and the building's condition was good in comparison to the years of neglect.

Influencing Factors for Compliance Intention of Information Security Policy (정보보안 정책 준수 의도에 대한 영향요인)

  • Kim, Sang-Hoon;Park, Sun-Young
    • The Journal of Society for e-Business Studies
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    • v.16 no.4
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    • pp.33-51
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    • 2011
  • This research derived the influencing factors for employees' compliance with the information security policy in organizations on the basis of Neutralization Theory, Theory of Planned Behavior and Protection Motivation Theory. To empirically analyze the research model and the hypotheses, data were collected by conducting web survey, 194 of 207 questionnaires were available. The test of causal model was conducted by PLS. Reliability, validity and model fit were found to be statistically significant. the results of hypotheses tests showed that seven ones of eight hypotheses could be accepted. The theoretical implications of this study are as follows : 1) this study is expected to play a role of baseline for future research about employee compliance with the information security policy, 2) this study attempted interdisciplinary approach through combining psychology and information system security research, and 3) it suggested concrete operational definitions of influencing factors for information security policy compliance through comprehensive theoretical review. Also, this study has some practical implications. First, it can provide the guideline to support the successful execution of the strategic establishment for implement of information system security policies in organizations. Second, it is proved that the need for conducting education and training program suppressing employees. neutralization psychology to violate information security policy should be emphasized in the organizations.

Detection of antibodies and antigens of Aujeszky's disease virus using dot-immunoassay (Dot-immunoassay를 이용한 Aujeszky's disease virus항원 및 항체 검출)

  • Jun, Moo-hyung;Cho, Young-sung;Chang, Kyung-soo
    • Korean Journal of Veterinary Research
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    • v.34 no.3
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    • pp.529-536
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    • 1994
  • To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

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Study on the correlation between long-term exposure tests and accelerated corrosion tests by the combined damage of salts (염해 및 복합열화에 의한 부식촉진시험과 장기폭로 시험의 상관성에 관한 연구)

  • Park, Sang Soon;Lee, Min Woo
    • Corrosion Science and Technology
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    • v.13 no.6
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    • pp.214-223
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    • 2014
  • Interest in the durability assessment and structural performance has increased according to an increase of concrete structures in salt damage environment recent years. Reliable way ensuring the most accelerated corrosion test is a method of performing the rebar corrosion monitoring as exposed directly to the marine test site exposure. However, long-term exposure test has a disadvantage because of a long period of time. Therefore, many studies on reinforced concrete in salt damage environments have been developed as alternatives to replace this. However, accelerated corrosion test is appropriate to evaluate the critical chlorine concentration in the short term, but only accelerated test method, is not easy to get correct answer. Accuracy of correlation acceleration test depends on the period of the degree of exposure environments. Therefore, in this study, depending on the concrete mix material, by the test was performed on the basis of the composite degradation of the salt damage, and investigate the difference of corrosion initiation time of the rebar, and indoor corrosion time of the structure, of the marine environment of the actual environments were inuestigated. The correlation coefficient was derived in the experiment. Long-term exposure test was actually conducted in consideration of the exposure conditions submerged zone, splash zone and tidal zone. The accelerated corrosion tests were carried out by immersion conditions, and by the combined deterioration due to the carbonation and accelerated corrosion due to wet and dry condition.

Studies on Viral Disease of masu salmon, Oncorhynchus masou-II Isolation of infectious hematopoietic necrosis virus form masu salmon fry (산천어의 바이러스성 질병에 관한 연구-II -산천어 치어에서 1HNV 분리-)

  • Sohn, Sang-Gyu;Park, Myoung-Ae;Park, Jeong-Woo
    • Journal of fish pathology
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    • v.6 no.2
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    • pp.87-92
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    • 1993
  • In February of 1990, an epizootic disease to masu salmon. Onchorynchus masou cultured at the hatchery of trout in Samchuk. Kwangwondo have broken out and induced heavy mortality. An infectious hematopoietic necrosis virus(IHNV) was isolated from diseased masu salmon fry by the use of fish cell line, CHSE-214. This IHNV isolated from masu salmon was compared with USA isolates of IHNV, SRCV and RB-76 by analysis of virion proteins in sodium dodecyl sulfate poly-acrylamide gel electrophoresis (SDS-PAGE) and neutralization tests with two monoclonal antibodies raised against SRCV(MAb SRCV/A4) and RB-76(MAb RB/B5). In the antigenicity and the size of structural proteins. this IHNV, SCS atrain was smilar to RB-76 belonged to the electropherotype I proposed by Hsu et al.(1986).

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A Case Study on Spatting Distresses in Cold Regions (추운 지역의 스폴링 파손 사례에 관한 연구)

  • Hong, Seung-Ho;Yoo, Tae-Seok;Kwon, Soon-Min;Jeong, Jin-Hoon
    • International Journal of Highway Engineering
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    • v.7 no.4 s.26
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    • pp.79-89
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    • 2005
  • Field and laboratory investigations were performed for concrete pavement of the Yeongdong Expressway located in western part of the Kangwon Province where lots of the substantially large spatting distresses were found. The spatting distresses were investigated to the naked eye in the field, and splitting tensile strength, air void, and neutralization tests were performed for the cores obtained from the pavement. In addition, load transfers at joints and dynamic bearing capacities at slab centers were measured to identify the lowering of the structural capability of the pavement. It was judged that the investigated concrete slabs were affected by freezing and thawing action because the air voids of the cores were substantially low. Therefore, it was concluded that the low air voids affected the lots of the large spatting distress in the pavement located in the region of cold winter.

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