• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.11
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• pp.1986-1996
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• 2003

Methodology based on the elastic-plastic fracture mechanics has been widely accepted in predicting the critical crack length(CCL) of pressure tubes of CANDU nuclear plants. A conservative estimate of CCL is obtained by employing the J-resistance curves measured with the specimens satisfying plane strain condition as suggested in the ASTM standard. Due to limited thickness of the pressure tubes the curved compact tension(CT) specimens taken out from tile pressure tube have been used in obtaining J-resistance curves. The curved CT specimen inevitably introduce slant fatigue crack during precracking. Hence, effect of specimen geometry and slant crack on J-resistance curve should be explored. In this study, the difference of J integral values between the standard CT specimens satisfying plane strain condition and the nonstandard curved CT with limited thickness (4.2mm) is estimated using finite element analysis. The fracture resistance curves of Zr-2.5Nb obtained previously by other authors are critically discussed. Various finite element analysis were conducted such as 2D analysis under plane stress and plane strain conditions and 3D analysis for flat CT, curved CT with straight crack and curved CT with slant crack front. J-integral values were determined by local contour integration near the crack tip, which was considered as accurate J-values. J value was also determined from the load versus load line displacement curve and the J estimation equation in the ASTM standard. Discrepancies between the two values were shown and suggestion was made for obtaining accurate J values from the load line displacement curves obtained by the curved CT specimens.

• IMMUNE NETWORK
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• v.6 no.2
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• pp.76-85
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• 2006

Background: Chemotaxis is one of the cardinal functions of leukocytes, which enables them to be recruited efficiently to the right place at the right time. Analyzing chemotactic activities is important not only for the study on leukocyte migration but also for many other applications including development of new drugs interfering with the chemotactic process. However, there are many technical limitations in the conventional in vitro chemotaxis assays. Here we applied a new optical assay to investigate chemotactic activities induced in differentiated HL-60 cells. Methods: HL-60 cells were stimulated with 0.8% dimethylformamide (DMF) for 4 days. The cells were analyzed for morphology, flow cytometry as well as chemotactic activities by a time-lapse videomicroscopic assay using a chemotactic microchamber bearing a fibronectin-coated cover slip and an etched silicon chip. Results: Videomicroscopic observation of the real cellular motions in a stable concentration gradient of chemokines demonstrated that HL-60 cells showed chemotaxis to inflammatory chemokines (CCL3, CCL5 and CXCL8) and also a homeostatic chemokine (CXCL12) after DFM-induced differentiation to granulocytic cells. The cells moved randomly at a speed of $6.99{\pm}1.24{\mu}m/min$ (n=100) in the absence of chemokine. Chemokine stimulation induced directional migration of differentiated HL-60 cells, while they still wandered very much and significantly increased the moving speeds. Conclusion: The locomotive patterns of DMF-stimulated HL-60 cells can be analyzed in detail throughout the course of chemotaxis by the use of a time-lapse videomicroscopic assay. DMF-stimulated HL-60 cells may provide a convenient in vitro model for chemotactic studies of neutrophils.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.299-309
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• 2019

Objective: This study aimed to investigate the effect of pre-applied orthodontic force on the regeneration of periodontal ligament (PDL) tissues and the underlying mechanisms in tooth replantation. Methods: Orthodontic force (50 cN) was applied to the left maxillary first molars of 7-week-old male Sprague-Dawley rats (n = 32); the right maxillary first molars were left untreated to serve as the control group. After 7 days, the first molars on both sides were fully luxated and were immediately replanted in their original sockets. To verify the effects of the pre-applied orthodontic force, we assessed gene expression by using microarray analysis and real-time reverse transcription polymerase chain reaction (RT-PCR), cell proliferation by using proliferating cell nuclear antigen (PCNA) immunofluorescence staining, and morphological changes by using histological analysis. Results: Application of orthodontic force for 7 days led to the proliferation of PDL tissues, as verified on microarray analysis and PCNA staining. Histological analysis after replantation revealed less root resorption, a better arrangement of PDL fibers, and earlier regeneration of periodontal tissues in the experimental group than in the control group. For the key genes involved in periodontal tissue remodeling, including CXCL2, CCL4, CCL7, MMP3, PCNA, OPG, and RUNX2, quantitative RT-PCR confirmed that messenger RNA levels were higher at 1 or 2 weeks in the experimental group. Conclusions: These results suggest that the application of orthodontic force prior to tooth replantation enhanced the proliferation and activities of PDL cells and may lead to higher success rates with fewer complications.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.287-294
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• 2021

Background: Ginsenoside Rb1 (G-Rb1), one of the major active compounds in Panax ginseng, has already been shown to reduce inflammation in various diseases. Osteoarthritis (OA) has traditionally been considered a degenerative disease with degradation of joint articular cartilage. However, recent studies have shown the association of inflammation with OA. In the present study, we investigated whether Rb1 had an antiinflammatory effect on monoiodoacetate (MIA)-induced OA in ovariectomized rats as a model of postmenopausal arthritis. Methods: G-Rb1 at a dosage of 3 and 10 ㎍/kg body weight was administered every 3 days intraarticularly for a period of 4 weeks to observe antiarthritic effects. Diclofenac (10 mg/kg) served as a positive control. Results: The administration of Rb1 significantly ameliorated OA inflammatory symptoms and reduced serum levels of inflammatory cytokines. Furthermore, G-Rb1 administration considerably enhanced the expression of bone morphogenetic protein-2 and collagen 2A and reduced the levels of matrix metalloproteinase-13 genes, indicating a chondroprotective effect of G-Rb1. G-Rb1 also significantly reduced the expression of several inflammatory cytokines/chemokines (interferon gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1)/CCL-2, interleukin [IL]-1β, and IL-6). Histological analysis demonstrated that G-Rb1 significantly attenuated the pathological changes in MIA-induced OA in ovariectomized rats. Safranin O and toluidine blue staining further demonstrated that G-Rb1 effectively prevented the degradation of cartilage and glycosaminoglycans, respectively. Conclusion: Overall, our results suggest that G-Rb1 exerts cartilage protective effect on MIA-induced ovariectomized OA rats, by inhibiting inflammatory mediators such as IL-6, IL-1β, MCP-1/CCL-2, cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE2). These results shed a light on possible therapeutic application of G-Rb1 in OA.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.13.1-13.11
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• 2023

Background: Highly pathogenic avian influenza viruses (HPAIVs) is an extremely contagious and high mortality rates in chickens resulting in substantial economic impact on the poultry sector. Therefore, it is necessary to elucidate the pathogenic mechanism of HPAIV for infection control. Objective: Gene set enrichment analysis (GSEA) can effectively avoid the limitations of subjective screening for differential gene expression. Therefore, we performed GSEA to compare HPAI-infected resistant and susceptible Ri chicken lines. Methods: The Ri chickens Mx(A)/BF2(B21) were chosen as resistant, and the chickens Mx(G)/BF2(B13) were selected as susceptible by genotyping the Mx and BF2 genes. The tracheal tissues of HPAIV H5N1 infected chickens were collected for RNA sequencing followed by GSEA analysis to define gene subsets to elucidate the sequencing results. Results: We identified four differentially expressed pathways, which were immune-related pathways with a total of 78 genes. The expression levels of cytokines (IL-1β, IL-6, IL-12), chemokines (CCL4 and CCL5), type interferons and their receptors (IFN-β, IFNAR1, IFNAR2, and IFNGR1), Jak-STAT signaling pathway genes (STAT1, STAT2, and JAK1), MHC class I and II and their co-stimulatory molecules (CD80, CD86, CD40, DMB2, BLB2, and B2M), and interferon stimulated genes (EIF2AK2 and EIF2AK1) in resistant chickens were higher than those in susceptible chickens. Conclusions: Resistant Ri chickens exhibit a stronger antiviral response to HPAIV H5N1 compared with susceptible chickens. Our findings provide insights into the immune responses of genetically disparate chickens against HPAIV.

• IMMUNE NETWORK
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• v.24 no.3
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• pp.27.1-27.14
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• 2024

The tumor microenvironment (TME) is formed by several immune cells. Notably, tumor-associated macrophages (TAMs) are existed in the TME that induce angiogenesis, metastasis, and proliferation of cancer cells. Recently, a point-mutated variant of IL-32θ was discovered in breast cancer tissues, which suppressed migration and proliferation through intracellular pathways. Although the relationship between cancer and IL-32 has been previously studied, the effects of IL-32θ on TAMs remain elusive. Recombinant human IL-32θ (rhIL-32θ) was generated using an Escherichia coli expression system. To induce M0 macrophage polarization, THP-1 cells were stimulated with PMA. After PMA treatment, the cells were cultured with IL-4 and IL-13, or rhIL-32θ. The mRNA level of M1 macrophage markers (IL-1β, TNFα, inducible nitric oxide synthase) were increased by rhIL-32θ in M0 macrophages. On the other hand, the M2 macrophage markers (CCL17, CCL22, TGFβ, CD206) were decreased by rhIL-32θ in M2 macrophages. rhIL-32θ induced nuclear translocation of the NF-κB via regulation of the MAPK (p38) pathway. In conclusion, point-mutated rhIL-32θ induced the polarization to M1-like macrophages through the MAPK (p38) and NF-κB (p65/p50) pathways.

• Korean Journal of Optics and Photonics
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• v.19 no.3
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• pp.182-186
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• 2008

The prism spectrometer is a standard device for the measurement of refractive index; it is used in undergraduate laboratories. Typically, however, lots of attention is required in the alignment, and the accuracy of the obtained refractive index is not so high in spite of the durability of the device. The maximum and minimum deviation method, which compensates the disadvantages of the prism spectrometer, can be composed cost effectively using a length marking tape and a rotating platform. It can measure the refractive indices accurately by utilizing a wide screen. In this study, the equal sided hollow prism whose length is 26 mm was fabricated and measured the refractive indices of seven kind of liquids (pure water, $C_3H_5(OH)_2$, $CCl_4$, $C_6H_4NH_2$, $CS_2$, $C_6H_4(CH_3)_2)$ by using the prism spectrometer and maximum and minimum deviated laser beam method at the wavelengths of He-Ne laser (${\lambda}$= 632.8 nm) and YVO4 laser (${\lambda}$= 532 nm). The result shows that the data obtained by the latter method are more accurate and precise than those obtained by the former device.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.267-272
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• 2007

Various kinds of RI wastes are discharged from licensed organizations of radioisotopes les such as hospitals and clinic organizations, educational organizations, research institutions, and public organizations. Radioiodines such as $^{125}I\;and\;^{131}I$ are radioisotopes mainly used in nuclear medicine and industry. A method for the determination of radioiodines in RI wastes has been applied to measure low level activity using acid decomposition method and HPGe gamma ray spectrometer. Prior to analysis of real samples, $^{131}I$ reference solution and 10 g of yellow tissue paper was added to flask in mantle and was heated in 100 mL of 0.4 N $K_2Cr_2O_7$ and 100 mL of 9 M $H_2SO_4$, and then distilled after adding 10 mL of 30% $H_2PO_3$ and 1 mL of 30% $H_2O_2$. The condensed iodine by circulator was extracted into $CCl_4$, then back-extracted into the aqueous phase with 10 mL of 5% $K_2SO_2$ solution. Finally, $^{131}I$ was measured at 364.48 keV using HPGe gamma ray spectrometer after precipitation and filtration. Chemical yield of three steps such as acid decomposition process, chemical separation process, and precipitation and filtration process was more han 94% respectively, MDA(Minimum Detectable Activity) of $^{131}I$ at this analytical condition was 0.6 Bq/g.

• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.5-11
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• 2005

When inoculating with B. bassiana 101A for the mass production of B. corpus, the infection ratio was high with regardless of the treating time with highly-humidity if the concentration of spore was 1.0${\times}$$10^8$ spores/m/, but that was low if the concentration was 1.0${\times}$$10^7$ spores/m/. In the study of the activities according to the coserving temperature or days of the B. bassiana spawn, the infection ratio of 90% was maintained for 12 days in the temperature of $4^{\circ}C$. However, the infection ratio was rapidly dropped to the below of 5% after conserved for 48 hours in the temperature of $25^{\circ}C$. Besides, the activities of the original isolate had no difference after conserved for 12 months in the temperature of $4^{\circ}C$, so that the infection ratio 90% could be mintatined. In the measure of liver-protecting activities of B. bassiana 101A, the recovering effect was 43.5% and 65.7% respectively in the poisonous treatment induced with galactosamine, compared with liver-protecting activities of Silymarin and DDB in the $H_2O$ fraction. In the poisonous treatment induced with $CCl_4$ the recovering effect was 100% and 69.3% respectively, compared with liver-protecting activities of Silymarin and DDB in the EtOAc fraction.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.224-238
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• 1992

Hepatic fibrosis was induced in Sprague-Dawley rats to evaluate the ultrastructural changes of fat-storing cells(Ito cells). For experimental induction of liver fibrosis, the rats were administered intraperitoneally with 0.5ml of 50% $Ccl_4$ solution per Kg body weight, twice weekly for 12 weeks. The rats were sacrified every week. The liver tissues were examined under light and eletron microscopes. And the immunohistochemical study of desmin was also performed. The results were summarized as follows : Light microscopic findings : The cellular infiltrations with inflammatory cells and Kupffer cells developed from 1 week after $Ccl_4$ injection, and were the most severe in 4 weeks. The strong immunoreactivity for desmin was also evident in 4 weeks. The centrilobular necrosis and fibrosis developed from 2 weeks after injection, and the necrosis persisted until 8 weeks. The progress of fibrosis was accompanied by decreases in cellular infiltration and reactivity for desmin, and increased gradual nodular formation was also observed. The cirrhosis was developed after 10 weeks. Electron microscopic findings : An increase in number of fat-storing cells was observed from 1 week after injection. Transitional cells characterized by a depletion of lipid droplets and a hypertrophy of the rER appeared after 2 weeks. The number of transitional cells with abundant collagen fibers in the extracellular spaces increased in 4 weeks. With progression of fibrosis the number of fat-storing cells decreased and proliferating fibroblasts with dilated rER were observed. According to these results it was revealed that there was an apparent transition from fat-storing cells to transitional cells and to fibroblasts. These cells had a few similar characteristics and may belong to the same cell population. Thus it was suggested that fat-storing cells might play an important role in hepatic fibrosis.