• International Journal of Oral Biology
• /
• v.32 no.2
• /
• pp.59-65
• /
• 2007

It has been well known that excitatory amino acids, primarily glutamate, are involved in the transmission of nociception in pathological and physiological conditions in the spinal and brainstem level. Recently, peripheral glutamate also play a critical role in the peripheral nociceptive transmissions. The present study investigated the role of N-methyl-D-aspartic acid (NMDA) or non-NMDA ionotropic glutamate receptors in formalin-induced TMJ pain. Experiments were carried out on male Sprague-Dawley rats weighing 220-280 g. Intra-articular injection was performed under halothane anesthesia. Under anesthesia, AP-7 (10, $100\;{\mu}M$, $1\;mM/20\;{\mu}L$), a NMDA receptor antagonist, or CNQX disodium salt (0.5, 5, 50, $500\;{\mu}M/20\;{\mu}L$), a non-NMDA receptor antagonist, were administered intra-articularly 10 min prior to the application of 5% formalin. For each animal, the number of behavioral responses, such as rubbing and/or scratching the TMJ region, was recorded for nine successive 5-min intervals. Intra-articular pretreatment with 1 mM of AP-7 or $50\;{\mu}M$ CNQX significantly decreased the formalin-induced scratching behavioral responses during the second phase. Intra-articular pretreatment with $500\;{\mu}M$ of CNQX significantly decreased the formalin-induced scratching behavior during both the first and the second phase. These results indicate that the intra-articular administration of NMDA or non-NMDA receptor antagonists inhibit formalin-induced TMJ nociception, and peripheral ionotropic glutamate receptors may play an important role in the TMJ nociception.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.6
• /
• pp.76-82
• /
• 2016

Recently, environmental sustainability of the transitional explosives and propellants is an issue of growing importance in energetic materials. For examples, ammonium perchlorate(AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, hydrazinium nitroformate(HNF) is an effective candidate substance for eco-friendly oxidizer, which has high density, pressure index, and less smog generating property during combustion for the thrust control system. This study was controlled the size distribution and shapes through various conditions. Length and diameter ratio(L/D) of crystals has below 1 : 3, and the particle size was two types of $200{\mu}m$ and $50{\mu}m$.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.5
• /
• pp.1189-1196
• /
• 1988

Thermal entrance lengths of turbulent tube flow for viscoelastic polymer solutions are investigated experimentally in the recirculating flow system with tubes of inside diameters 8.5mm(L/D=710) and 10.3mm(L/D=1158), respectively. In the present system, the hydrodynamic and thermal boundary layers develop simultaneously from the beginning of the test section. To provide the boundary condition of constant heat flux at the wall, the test tubes are heated directly by electricity. The polymer solution used in the current study is 1000 wppm aqueous solution of polyacrylamide(Separan AP-273). The apparent viscosity of the polymer solutions circulating in the flow system are measured by the capillary tube viscometer at regular time intervals. Thermal entrance lengths vary due to the rate of degradation. The entrance lengths of degraded polymer solutions are about 500~600 times the diameter. However, the entrance lengths of fresh polymer solutions are greater than the lengths of the test tubes used in this study suggesting that thermal entrance lengths for viscoelastic polymer solutions are greater than 1100 tube times the diameters. Friction factor is almost insensitive to the degradation, but the heat transfer $j_{H}$-factor is affected seriously by degradation. Based on the present experimental data of fresh solutions a correlation for the heat transfer $j_{H}$-factor is presented.ted.

• Food Science of Animal Resources
• /
• v.42 no.6
• /
• pp.1031-1045
• /
• 2022

Postbiotics are defined as probiotics inactivated by heat, ultraviolet radiation, sonication, and other physical or chemical stresses. Postbiotics are more stable than probiotics, and these properties are advantageous for food additives and pharmacological agents. This study investigated the immunostimulatory effects of heat-treated Lactiplantibacillus plantarum LM1004 (HT-LM1004). Cellular fatty acid composition of L. plantarum LM1004 isolated form kimchi was analyzed by gas chromatography-mass spectrometry detection system. The nitric oxide (NO) content was estimated using Griess reagent. Immunostimulatory cytokines were evaluated using enzyme-linked immunosorbent assay. Relative protein expressions were evaluated by western blotting. Phagocytosis was measured using enzyme-labelled Escherichia coli particles. L. plantarum LM1004 showed 7 kinds of cellular fatty acids including palmitic acid (C16:0). The HT-LM1004 induced release of NO and upregulated the inducible NO synthase in RAW 264.7 macrophage cells. Tumor necrosis factor-α and interleukin-6 levels were also increased compared to control (non-treated macrophages). Furthermore, HT-LM1004 modulated mitogen-activated protein kinase (MAPK) subfamilies including p38 MAPK, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase. Therefore, these immunostimulatory effects were attributed to the production of transcriptional factors, such as nuclear factor kappa B (NF-κB) and the activator protein 1 family (AP-1). However, HT-LM1004 did not showed significant phagocytosis of RAW 264.7 macrophage cells. Overall, HT-LM1004 stimulated MAPK/AP-1 and NF-κB expression, resulting in the release of NO and cytokines. These results will contribute to the development of diverse types of food and pharmacological products for immunostimulatory agents with postbiotics.

• Research in Community and Public Health Nursing
• /
• v.33 no.1
• /
• pp.128-138
• /
• 2022

Purpose: This study aimed to identify the factors influencing the wellness of call center employees. Methods: From December 2018 to October 2019, a cross-sectional study was conducted with 155 workers recruited from the call centers in Seoul, South Korea. Data were collected using self-administered questionnaires. The questionnaires were used to measure the following scales: Korean occupational stress scale, emotional labor scale, work-life balance scale and wellness scale. Using the SPSS 26.0 program, the descriptive statistics, independent t-test, ANOVA, correlation analysis, and multiple regression analysis were conducted. Results: The mean score of the wellness level of call center employees was 3.05 out of a maximum of 5.00. More wellness level of call center employees was associated with gender, psychiatric diagnosis, and call characteristics. A multiple regression analysis indicated that the total scores on the wellness scale were predicted by call characteristics, occupational stress and work-life balance, with an explanatory power of 42.2%. Conclusion: Study findings show that it is necessary to promote wellness in call center workers with differentiated strategies according to call characteristics, occupational stress and work-life balance. This implies that it is necessary to understand the call characteristics and patterns of workers and to provide an innovative wellness program tailored to individual characteristics for an effective management of the emotional labor and occupational stress.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.13 no.1
• /
• pp.58-65
• /
• 2010

Purpose: Since there are few studies involving acute pancreatitis in children, we reviewed our experience with this medical condition to describe the clinical features. Methods: A retrospective analysis was conducted by reviewing the medical records of 41 patients with AP who were admitted to the Department of Pediatrics of Pusan National University Hospital between January 1996 and June 2007. Results: Twenty males and 21 females (mean age, 8.7${\pm}$4.5 years) were included. In 22 patients (53.7%), no definitive causes were found. The most common etiologies were choledochal cysts (22.0%). Necrotizing pancreatitis was diagnosed in 5 patients (12.2%), and recurrent acute pancreatitis in 4 patients (9.8%). CT findings included pancreatic swelling (43.9%), peripancreatic fluid collection (29.3%), ascites (24.4%), and peripancreatic fat necrosis (12.2%). Serum amylase and lipase levels at diagnosis were 535.3${\pm}$553.2 and 766.2${\pm}$723.6 U/L, respectively, and were normalized within 1 week in 22 and 14 patients, respectively. On the basis of the Balthazar scale, 2 patients were diagnosed with severe AP. In 4 patients (9.8%), a surgical procedure was indicated. Major complications included ascites (32.3%), sepsis (16.1%), and pseudocyst and renal impairments (12.9%). Two patients died from multi-organ failure. Conclusion: The etiologies of AP in children are varied. Most children have a single episode and a self-limited course. However, AP of childhood still carries significant morbidity and mortality. Early diagnosis, appropriate treatment according to disease severity, and management of complications are important.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.1
• /
• pp.13-22
• /
• 2009

The composite resin, due to its esthetic quality, is considered the material of choice for restoration of anterior teeth. To get a satisfactory result in the composite resin restorations, it is necessary to choose right shade. At present, most of the commercial composite resins are based on the Vita Lumin shade guides or shade guides that are provided by their company, but color differences among them might be expected even using the same shade in various materials. This study is to measure color differences between various light-cured composite resins and shade guides and to provide the clinicians with information which may aid in improved color match of esthetic restoration. Four kinds of light-cured composite resins (Gradia Direct (GD), Z250 (Z250), Clearfil AP-X (AP-X), Esthet X (E X)) and shade guides with A2 and A3 shade were used. Three specimens of each material and one specimen of each shade guide were made. Each composite resin was filled into the Teflon mold (1.35 mm depth, 8 mm diameter), followed by compression, polymerization and polishing with wet sandpaper. Shade guides were grinded with polishing stones and rubber points to a thickness of approximately 1.35 mm. Color characteristics were performed with a spectrophotometer(color i5, GretagMacbeth, USA). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$, $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E^*ab$) between composite resins and shade guides. CIE standard D65 was used as the light source. The results were as follows : 1. Among the $L^*$, $a^*$, $b^*$ values of most of 4 kinds of composite resin specimens which are produced by same shade, there were significant differences(p<0.05). 2. Among all 4 kinds of composite resin specimens which are produced by same shade, there were color differences that is perceptible to human eye(${\Delta}E^*>3.3$). 3. Between most of composite resin specimens investigated and their corresponding shade guides, there were color differences that is perceptible to human eye(${\Delta}E^*>3.3$). 4. In the clinical environment, it is recommended that custom shade guides be made from resin material itself for better color matching. Shade guides supplied by manufacturers or Vita Lumin shade guide may not provide clinicians a accurate standard in matching color of composite resins, and there are perceptible color differences in most of products. Therefore, it is recommended that custom shade guides be made from resin material itself and used for better color matching.

• Journal of Life Science
• /
• v.24 no.10
• /
• pp.1085-1091
• /
• 2014

The purpose of this study was to determine the effect of selenate on adipocyte differentiation and to identify genes involved in the modulation of adipogenesis in 3T3-L1 cells. To test the effect of selenate on adipocyte differentiation, adipogenesis was induced in cells using various concentrations ($0-100{\mu}M$) of selenate. Various phases of adipogenesis were induced: postconfluent (PC), early phase (EP, d0-d2), postmitotic growth arrest (PM, d2-d4), and all period (AP). The PC cells exposed to selenate for 24 h displayed dose-dependent inhibition of intracellular lipid droplet accumulation on day 6 of adipogenesis. Two days of selenate treatment at EP or AP inhibited adipogenesis, with an approximately 20-80% reduction in lipid accumulation compared to that of a control (p<0.05). When preadipocytes were exposed to selenate during the PM period, the antiadipogenic effect of selenate was attenuated. Two types of selenoprotein genes (Seps1 and Sepp1) were up-regulated by the selenate treatment during mitotic clonal expansion, whereas these genes were down-regulated during PM growth arrest (p<0.05). The findings demonstrate the antiadipogenic function of selenate and the possible involvement of Sepp1 and Seps1 genes in selenate-inhibited adipogenesis in 3T3-L1 cells.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.15 no.1
• /
• pp.1-7
• /
• 2007

At present, multivoltine silkworm races reared five times per year involving huge manpower and rearing expenditure. Egg diapausing behavior is facultative in multivoltine and egg diapause was induced in selected multivoltine races by regulating temperature at $18^{\circ}C$, relative humidity 80% and photoperiod (6L:18D) in the late stage silkworm rearing. The maximum percentage of egg diapause induction was recorded in Rong Diazo, Diazo and MW13 showed 94%, 93% and 92% respectively, whereas the races A14DY and OS-616 showed minimum diapause induction 15% and 18% respectively. The diapause induced multivoltine eggs were preserved up to six months by cold preservation schedule normally adopted for bivoltine. After three and six months egg preservation, the diapause induced layings were released and observed for hatching percentage, all races showed above 82 % of hatching except the race AP12, which showed only 78 % of hatching. This methods reduce the crop cycle, gives strong safety backup and preventing the genetic erosion. This study helps formulating a new conservation method for multivoltine silkworm germplasm.

• Journal of the Korean Chemical Society
• /
• v.57 no.3
• /
• pp.341-351
• /
• 2013

Zn(II), Cd(II) and Hg(II) complexes with a general composition[$M(L)_2(X)_2$], where L=4-aminopyridine (4AP) and $X=NO_2{^-}$ were prepared under microwave irradiation. The metal complexes were characterized by elemental analyses, molar conductance, IR, Far-IR, electronic, NMR ($^1H$, $^{13}C$), XPS spectral and thermal studies. The spectroscopic studies reveal the composition, different modes of bonding, electronic transition, different chemical environment of C and H atoms and the electronic state of the metal atoms. On the basis of the characterization data, tetrahedral geometry is suggested for all the complexes. The free ligand (4-aminopyridine) and their metal complexes were screened against phytopathogenic fungi and bacteria in vitro and the activities were compared.