A laser scabbling experiment was performed using a high-power fiber laser to investigate the removal rate of the concrete block and the scabbled depth. Concrete specimens with a 28-day compressive strength of 30 MPa were used in this study. Initially, we conducted the scabbling experiment under a stationary laser beam condition to determine the optimum scan speed. The laser interaction time with the concrete surface varied between 3 s and 40 s. The degree of spalling and vitrification on the surface was primarily dependent on the laser interaction time and beam power. Furthermore, thermal images were captured to investigate the spatial and temporal distribution of temperature during the scabbling process. Based on the experimental results, the scan speed at which the optical head moved over the concrete was set to be 300 mm∙min−1 or 600 mm∙min−1 for the 4.8-kW or 6.8-kW laser beam, respectively. The spalling rates and average depth on the concrete blocks were measured to be 87 cm3∙min−1 or 227 cm3∙min−1 and 6.9 mm or 9.8 mm with the 4.8-kW or 6.8-kW laser beams, respectively.

Recently, the number and scale of projects being carried out within the enterprise are increasing. Accordingly, many companies are competitively introducing a Project Management Office (PMO) to efficiently manage these projects, allocate resources, and effectively link the projects and corporate strategies. However, the project manager who directly manages the project wants to receive support from the PMO in many areas for successful project management, but the project manager does not like to be interfered with by the PMO. On the other hand, the PMO may not be able to satisfy all the requirements of each PM as PMO oversees the entire project with limited resources. In addition, since the PMO must monitor and control the project and support the project according to the priorities of each project, conflicts with each PM can be formed. Therefore, in this study, based on the case of a company, the difference between the perceptions of PMs and PMOs about the importance of the required roles of PMOs is to be examined. As a result of the study, it was confirmed that the core functions and sub-functions of PMO, which PMO members and PMs consider important, are different. It was identified that the PMs valued the PMO function that would be helpful for their successful project execution. On the other hand, PMO members revealed that they had a relatively high priority for the roles to monitor and control project performance for which they were directly responsible.

Helicobacter (H.) pylori is one of the most common pathogenic bacteria in the human gut, and is also one of the most important factors that cause digestive disorders such as chronic inflammation, gastric ulcers, and even gastric cancer. Since the use of various antibiotics to treat H. pylori infection is associated with the development of resistance in this bacterium, the aim of this study was to determine the anti-H. pylori effects of Peucedanum japonicum extracts (PJE) in the stomach tissue of C57BL/6 mice. In this experimental study, 50 C57BL/6 mice in five groups were evaluated. After induction of H. pylori infection in mice with the standard strain of H. pylori (ATCC 43504), the infected mice were treated with 3 different doses of PJE in different groups. Then, the anti-H. pylori effects of PJE were evaluated by rapid urease test (CLO), histopathological exam and blood interleukin (IL)-8 ELISA analysis. Based on CLO results, H. pylori eradication effects of PJE was observed. H. pylori infection of C57BL/6 mice showed significant increase of histopathological lesion scores. However, the treatment of PJE showed significant decrease of histopathological lesion scores. The treatment of PJE decreased gastric inflammation and mucosal lesions in the stomach of H. pylori-infected mice. Blood IL-8 levels were elevated 4 weeks after H. pylori inoculation. However, the treatment of PJE showed significant decrease of IL-8 level. According to the results of this study, PJE could be useful in the reduction of H. pylori infection in the mouse model.

C-reactive protein (CRP) is an acute-phase protein produced by hepatocytes. The plasma concentration of CRP peaks around 48 hours following stimulation. A rapid decrease in CRP levels is observed when the stimuli end. Considering these characteristics of CRP, it is used to evaluate acute inflammatory responses in clinics. In addition, as it reflects the degree of surgical trauma, measuring the CRP concentration is an effective method of evaluating tissue damage depending upon the surgical method. As CRP is also an acute-phase protein in dogs, the purpose of the present study was to compare the factors related to acute inflammatory responses between dogs undergoing elective general surgery (GS) and orthopedic surgery (OS). A total of 44 healthy dogs were included in this study. The sex ratio of dogs that underwent OS was similar. Both groups showed increased CRP levels and white blood cell (WBC) counts on post-operative day (POD) 1-2. The CRP level in the OS group on POD 1-2 was significantly higher than that of the GS group and it was increased about 16-fold compared to the pre-operative value. No significant difference in WBC counts was observed between the two groups. Although a slight increase in the WBC count was observed on POD 1-2 in both groups, it was near the reference range during follow-up. Thus, measuring CRP levels can be more effective in evaluating acute inflammatory responses than WBC counts. Although a high level of post-operative serum CRP concentrations was observed in the OS group, it rapidly decreased to a level similar to the pre-operative value if there were no post-operative complications.

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the colon and rectum with intervals of acute exacerbation. Its etiology remains unknown, although recent studies suggest that pro-inflammatory cytokines initiate the inflammatory responses. In this study, we investigated the ameliorative effects of YB-21 (new product containining Lactobacillus plantarum, Barley Bran and Nymphaeaceae) in a dextran sulfate sodium (DSS)-induced colitis in mice. The experimental groups were divided into 6 groups (n = 10) of ICR mice: normal control(NC), DSS-treated(PC, positive control), DSS+latic-L-treated (3×107CFU/ml), DSS+latic-M-treated (3×109CFU/ml), DSS+latic-H-treated (3×1011CFU/ml), and DSS+YB-21-treated. Histological examinations indicated that YB-21 suppressed edema, mucosal damage, and the loss of crypts induced by DSS. Moreover, YB-21 reduced serum level expressions of, tumor necrosis factor-α (TNF-α). These results suggest that YB-21 has an anti-colitic effect by the suppression of intestinal inflammatory responses in DSS-induced colitis in mice.

목적 : 본 연구는 레이저 주사광학계에 응용되는 보급형 f-theta 렌즈의 성능을 향상시키기 위하여 수행되었다. 방법 : ZemaxTM 렌즈설계 프로그램을 이용하여 새로운 f-theta 렌즈 시스템을 설계하였다. 연구 결과는 spot diagram, ray fan, 단색수차 등 3가지 항목에서 선행 연구와 비교·평가되었다. 결과 : 새롭게 설계된 f-theta 렌즈 시스템은 spot size와 레이저 입사광선의 왜곡도가 감소하였으며 특히 구 면수차가 77% 감소하여 대폭 개선되었다. 결론 : 본 연구에서 설계된 f-theta 렌즈 시스템은 전반적으로 상의 질과 성능이 크게 향상되었으며, 레이저 프린터 장비 등에 적용될 수 있으리라 기대된다.