An accurate fatigue damage model for welded joints subjected to variable amplitude loading

Researchers in the past have proposed several fatigue damage models to overcome the shortcomings of the commonly used Miner's rule. However, requirements of material parameters or S-N curve modifications restricts their practical applications. Also, application of most of these models under variable amplitude loading conditions have not been found. To overcome these restrictions, a new fatigue damage model is proposed in this paper. The proposed model can be applied by practicing engineers using only the S-N curve given in the standard codes of practice. The model is verified with experimentally derived damage evolution curves for C 45 and 16 Mn and gives better agreement compared to previous models. The model predicted fatigue lives are also in better correlation with experimental results compared to previous models as shown in earlier published work by the authors. The proposed model is applied to welded joints subjected to variable amplitude loadings in this paper. The model given around 8% shorter fatigue lives compared to Eurocode given Miner's rule. This shows the importance of applying accurate fatigue damage models for welded joints.publishedVersio

Bacteriology division, Animal and Plant Quarantine Agency

ABSTRACT Background: Haemophilus parasuis is the etiological agent responsible for causing Glässer's disease in pigs, which are major respiratory pathogens that cause large economic losses in the pig industry worldwide. H. parasuis obtains transferrinbound iron by expressing two surface receptors, transferrin-binding protein A and B (TbpA and B). The TbpA and B are capable of binding to transferrin, and an impairment of iron uptake mechanisms is likely to induce virulence. For this reason, these proteins can be useful as a candidate target for H. parasuis vaccination. Also, the live attenuated Salmonella Typhimurium expressing recombinant antigens from other pathogens are attractive vaccine vectors. Materials, Methods & Results: In this study, we constructed attenuated S. Typhimurium vaccine strain by porcine neurtophil passage method. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. The aspartate β-semialdehyde dehydrogenase (asd) gene was eliminated from S. Typhimurium by one-step PCR. Deletion of asd region was confirmed by PCR using primers specific to the endpoints of the targeted region. TbpA fragment was amplified by PCR from genomic DNA of H. parasuis serotype 5. To construct TbpA expression plasmids, tbpA was subcloned downstream from the β-lactamase signal sequence in the multicopy asd + pYA3493 vector. This plasmid was subsequently electrotransformed into attenuated S. Typhimurium. The 636bp fragment of the tbpA gene of H. parasuis in attenuated S. Typhimurium was amplified by PCR and the in-frame fusion of the tbpA was confirmed by nucleotide sequencing. The used this strain with Asd + balanced-lethal plasmid pYA3493 vector to specify recombinant TbpA antigen, conserved immunogenic region of H. parasuis. Expression of the TbpA protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. The size of TbpA protein was estimated at about 30kDa. Mice were administered orally in order to evaluate protective efficacy of this vaccine strain against H. parasuis serotype 5. For efficacy test, female ICR mice (5 weeks old) were orally injected, intraperitoneally challenged with a lethal dose (4X10 5 CFU/mouse) of H. parasuis serotype 5, and examined the survival rates compared with vaccination and non-vaccination group. The experiment was terminated two weeks post-challenge. The live attenuated S. Typhimurium conserved pYA3493-TbpA antigen vaccine protected 40% of immunized mice against challenge of H. parasuis serotype 5. This result suggested that the live attenuated Salmonella Typhimurium vaccine expressing TbpA might be protection for Glässer's disease outbreaks caused by H. parasuis. Discussion: This paper has shown protected mice that attenuated S. Typhimurium strain using pYA3493 expresses TbpA antigen against H. parasuis. Vaccination using bacterins is an efficient way to control outbreaks of Glässers disease, but significant variability has been reported. Therefore, the development of a new vaccine system to prevent Glässers disease using pYA3493-TbpA will avoid the disadvantages of the currently used vaccines. We need further works to enhance protection rate and to determine the potential of the vaccine in pigs

Bacteriology division, Animal and Plant Quarantine Agency. Anyang 480-757

ABSTRACT Background: Haemophilus parasuis is the etiological agent responsible for causing Glässer's disease in pigs, which are major respiratory pathogens that cause large economic losses in the pig industry worldwide. H. parasuis obtains transferrinbound iron by expressing two surface receptors, transferrin-binding protein A and B (TbpA and B). The TbpA and B are capable of binding to transferrin, and an impairment of iron uptake mechanisms is likely to induce virulence. For this reason, these proteins can be useful as a candidate target for H. parasuis vaccination. Also, the live attenuated Salmonella Typhimurium expressing recombinant antigens from other pathogens are attractive vaccine vectors. Materials, Methods & Results: In this study, we constructed attenuated S. Typhimurium vaccine strain by porcine neurtophil passage method. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. The aspartate β-semialdehyde dehydrogenase (asd) gene was eliminated from S. Typhimurium by one-step PCR. Deletion of asd region was confirmed by PCR using primers specific to the endpoints of the targeted region. TbpA fragment was amplified by PCR from genomic DNA of H. parasuis serotype 5. To construct TbpA expression plasmids, tbpA was subcloned downstream from the β-lactamase signal sequence in the multicopy asd + pYA3493 vector. This plasmid was subsequently electrotransformed into attenuated S. Typhimurium. The 636bp fragment of the tbpA gene of H. parasuis in attenuated S. Typhimurium was amplified by PCR and the in-frame fusion of the tbpA was confirmed by nucleotide sequencing. The used this strain with Asd + balanced-lethal plasmid pYA3493 vector to specify recombinant TbpA antigen, conserved immunogenic region of H. parasuis. Expression of the TbpA protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. The size of TbpA protein was estimated at about 30kDa. Mice were administered orally in order to evaluate protective efficacy of this vaccine strain against H. parasuis serotype 5. For efficacy test, female ICR mice (5 weeks old) were orally injected, intraperitoneally challenged with a lethal dose (4X10 5 CFU/mouse) of H. parasuis serotype 5, and examined the survival rates compared with vaccination and non-vaccination group. The experiment was terminated two weeks post-challenge. The live attenuated S. Typhimurium conserved pYA3493-TbpA antigen vaccine protected 40% of immunized mice against challenge of H. parasuis serotype 5. This result suggested that the live attenuated Salmonella Typhimurium vaccine expressing TbpA might be protection for Glässer's disease outbreaks caused by H. parasuis. Discussion: This paper has shown protected mice that attenuated S. Typhimurium strain using pYA3493 expresses TbpA antigen against H. parasuis. Vaccination using bacterins is an efficient way to control outbreaks of Glässers disease, but significant variability has been reported. Therefore, the development of a new vaccine system to prevent Glässers disease using pYA3493-TbpA will avoid the disadvantages of the currently used vaccines. We need further works to enhance protection rate and to determine the potential of the vaccine in pigs

Dissemination and tracking of Salmonella spp. in integrated broiler operation

Controlling Salmonella in integrated broiler operation is complicated because there are numerous potential sources of Salmonella contamination, including chicks, feed, rodents, wild poultry operations, and the processing plant. The objective of this study was to investigate the distribution of Salmonella through all phases of two integrated broiler operations and to determine the key areas related to the control of all known sources of infection. Two different Salmonella serotypes were observed at integrated broiler chicken company A. S. enteritidis, the predominant company A isolate, was consistently found in the breeder farm, hatcheries, broiler farms, and chicken slaughterhouse. At company B, a total of six different serotypes, S. heidelberg, S. senftenberg, S. enteritidis, S. blockley, S. gallinarum, and S. virchow, were detected. Although S. heidelberg was not found in the broiler farms, it was consistently found in the breeder farm, hatcheries, and chicken slaughterhouse. In addition, S. enteritidis was found in the hatcheries, broiler farm, and chicken slaughterhouse. In order to obtain the genetic clonality, 22 S. enteritidis isolates were digested with XbaI and analyzed by pulsed-field gel electrohporesis (PFGE). A difference in the PFGE pattern was found to be related to the origin of the integrated broiler operation. These data support the critical need to control Salmonella in breeder farms and hatcheries, and demonstrate important points related to the control of infection in large-scale poultry operations of Korea

Establishment of a piglet model for peritoneal metastasis of ovarian cancer

Background : A piglet model for peritoneal metastasis (PM) of ovarian cancer was developed. It will contribute to establishing innovative chemotherapeutical and surgical strategies without any limitation on rodent models. Methods : A total of 12 four- to five-week-old piglets of 7 to 8 kg were used. Two phases of ovarian cancer cell injections were performed with laparoscopic surgery. In phase I trial, 5.0 × 106 SK-OV-3 cells in 0.1 ml suspension were inoculated into the omentum, peritoneum, and uterine horns of two piglets twice with a one-week interval. In the phase II trial, 5.0 × 106 SNU-008 cells in 0.1 ml suspension were injected only into uterine horns within the same time frame because tumor implantation after inoculation of SK-OV-3 cells was not observed at the omentum or peritoneum in the phase I trial. Modified peritoneal cancer index (PCI) score was used to monitor tumorigenesis up to 4 weeks after inoculation. Tumor tissues disseminated in the peritoneum 4 weeks after injection were used for histological examination with hematoxylin and eosin (H&E) and paired-box gene 8 (PAX-8) staining. Results : In the phase I trial, two piglets showed PM with modified PCI scores of 5 and 4 at 3 weeks after the first inoculation, which increased to 14 and 15 after 4 weeks, respectively. In the phase II trial, PM was detected in eight of ten piglets, which showed modified PCI scores of 6 to 12 at 4 weeks after the first inoculation. The overall incidence of PM from the total of 12 piglets after inoculation was 75%. Immunohistochemical H&E and PAX-8 staining confirmed metastatic tumors. Conclusions : This study provides strong evidence that piglets can be employed as a model for PM by inoculating ovarian cancer cell lines from humans. Using two cell lines, the PM rate is 75%.This research was supported by a grant from Seoul National University (No,800–20190437). Moreover, Commercializations Promotion Agency for R&D Outcomes supported this research with a grant funded by the Korea government (the Ministry of Science and ICT; No. 1711151316)

Prognostic role of computed tomography-based, artificial intelligence-driven waist skeletal muscle volume in uterine endometrial carcinoma

Abstract Objectives To investigate the impact of computed tomography (CT)-based, artificial intelligence-driven waist skeletal muscle volume on survival outcomes in patients with endometrial cancer. Methods We retrospectively identified endometrial cancer patients who received primary surgical treatment between 2014 and 2018 and whose pre-treatment CT scans were available (n = 385). Using an artificial intelligence-based tool, the skeletal muscle area (cm2) at the third lumbar vertebra (L3) and the skeletal muscle volume (cm3) at the waist level were measured. These values were converted to the L3 skeletal muscle index (SMI) and volumetric SMI by normalisation with body height. The relationships between L3, volumetric SMIs, and survival outcomes were evaluated. Results Setting 39.0 cm2/m2 of L3 SMI as cut-off value for sarcopenia, sarcopenia (< 39.0 cm2/m2, n = 177) and non-sarcopenia (≥ 39.0 cm2/m2, n = 208) groups showed similar progression-free survival (PFS; p = 0.335) and overall survival (OS; p = 0.241). Using the median value, the low-volumetric SMI group (< 206.0 cm3/m3, n = 192) showed significantly worse PFS (3-year survival rate, 77.3% vs. 88.8%; p = 0.004) and OS (3-year survival rate, 92.8% vs. 99.4%; p = 0.003) than the high-volumetric SMI group (≥ 206.0 cm3/m3, n = 193). In multivariate analyses adjusted for baseline body mass index and other factors, low-volumetric SMI was identified as an independent poor prognostic factor for PFS (adjusted HR, 1.762; 95% CI, 1.051–2.953; p = 0.032) and OS (adjusted HR, 5.964; 95% CI, 1.296–27.448; p = 0.022). Conclusions Waist skeletal muscle volume might be a novel prognostic biomarker in patients with endometrial cancer. Assessing body composition before treatment can provide important prognostic information for such patients

Highly Pathogenic Avian Influenza Virus (H5N1) in Domestic Poultry and Relationship with Migratory Birds, South Korea

During the 2006–2007 winter season in South Korea, several outbreaks of highly pathogenic avian influenza virus (H5N1) were confirmed among domestic poultry and in migratory bird habitats. Phylogenetic analysis showed that all isolates were closely related and that all belong to the A/bar-headed goose/Qinghai/5/2005–like lineage rather than the A/chicken/Korea/ES/2003–like lineage

Global Norms, Local Activism, and Social Movement Outcomes: Global Human Rights and Resident Koreans in Japan

The authors integrate social movement outcomes research and the world society approach to build a theoretical model to examine the impact of global and local factors on movement outcomes. Challenging the current research on policy change, which rarely examines the effects of global norms and local activism in one analysis, they argue (1) that global regimes empower and embolden local social movements and increase pressure on target governments from below, and (2) that local activists appeal to international forums with help from international activists to pressure the governments from above. When the pressures from the top and the bottom converge, social movements are more likely to succeed. Furthermore, these pressures are stronger in countries integrated into global society and on issues with strong global norms. The empirical analysis of social movements by resident Koreans in Japan advocating for four types of human rights—civil, political, social/economic, and cultural—demonstrates that the movements produced more successes as Japan\u27s involvement in the international human rights regime expanded since the late 1970s, and that activism on issues with strong global norms achieved greater successes. The analysis also shows that lack of cohesive domestic activism can undercut the chances of social movements\u27 success even with strong global norms on the issue

르장드르 다항식의 법 p^2 에 대한 합동식

In this article, we extend Z. H. Sun's congruences concerning Legendre polynomials P p−1 2 (x) to P p+1 2 (x) for odd prime p, which enables us to deduce some congruences resembling p+1 2 ∑ k=0 4pk + 4k 2 − 1 16 k (2k − 1) 2 (2k k)2 (mod p 2).이 논문에서 우리는 Z. H. Sun의 르장드르 다항식의 합동식 P p−1 2 (x) 에서 P p+1 2 (x) (단, p는 소수) 까지를 이용해서 이 합동식과 비슷한 합동식 p+1 2 ∑ k=0 4pk + 4k 2 − 1 16 k (2k − 1) 2 (2k k)2 (mod p 2) 을 유도한다