가덕도 인근 해역의 오염 현황 조사

문장원,홍혜경,민병윤 경남대학교 환경문제연구소 1995 환경연구 Vol.17 No.-

During the past two years. We surveyed the monthly variations of DO, PH, COD, TSS, PO4--P, TIN in Noksan. It seemed that the concentrations were gradationally increasing in all parameters as the landfill proceeding. It is the result that the influents of soils and sands were naturally increased as the landfill proceeding and organisms and nutrients of land are influenced to the ocean by increasing a rainfall.

High Glucose Causes Human Cardiac Progenitor Cell Dysfunction by Promoting Mitochondrial Fission: Role of a GLUT1 Blocker

( He Yun Choi ),( Ji Hye Park ),( Woong Bi Jang ),( Seung Taek Ji ),( Seok Yun Jung ),( Da Yeon Kim ),( Songhwa Kang ),( Yeon Ju Kim ),( Jisoo Yun ),( Jae Ho Kim ),( Sang Hong Baek ),( Sang Mo Kwon ) 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

Two pHZ1358 Derivative Vectors for Efficient Gene Knockout in Streptomyces

( Yun Long He ),( Zhi Jun Wang ),( Lin Quan Bai ),( Jing Dan Liang ),( Xiu Fen Zhou ),( Zi Xin Deng ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.4

Causes, Features, and Outcomes of Drug-Induced Liver Injury in 69 Children from China

( Yun Zhu ),( Yong Gang Li ),( Jia Bo Wang ),( Shu Hong Liu ),( Li Fu Wang ),( Yan Ling Zhao ),( Yun Feng Bai ),( Zhong Xia Wang ),( Jian Yu Li ),( Xiao He Xiao ) 대한소화기학회 2015 Gut and Liver Vol.9 No.4

Background/Aims: Drug-induced liver injury (DILI) is a frequent cause of pediatric liver disease; however, the data on DILI are remarkably limited. Methods: All 69 children hospitalized with DILI between January 2009 and December 2011 were retrospectively studied. Results: A total of 37.7% of the children had medical histories of respiratory infection. The clinical injury patterns were as follows: hepatocellular 89.9%, cholestatic 2.9%, and mixed 7.2%. Liver biopsies from 55 children most frequently demonstrated chronic (47.3%) and acute (27.3%) hepatitis. Hypersensitivity features, namely, fever (31.9%), rash (21.7%), and eosinophilia (1.4%), were found. Twenty-four children (34.8%) developed chronic DILI. Antibiotics (26.1%) were the most common Western medicines (WMs) causing DILI, and the major implicated herbs were Ephedra sinica and Polygonum multiflorum. Compared with WM, the children whose injuries were caused by Chinese herbal medicine (CHM) showed a higher level of total bilirubin (1.4 mg/dL vs 16.6 mg/dL, p=0.004) and a longer prothrombin time (11.8 seconds vs 17.3 seconds, p=0.012), but they exhibited less chronic DILI (2/15 vs 18/39, p=0.031). Conclusions: Most cases of DILI in children are caused by antibiotics or CHM used to treat respiratory infection and present with hepatocellular injury. Compared with WM, CHM is more likely to cause severe liver injury, but liver injury caused by CHM is curable. (Gut Liver 2015;9:525-533)

Analysis on temperature field of friction pair of aviation friction clutch based on different groove shapes of friction disk

He-yun Bao,Weidi Kong,Xiaonan Hou,Rupeng Zhu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

To examine the influence of the groove shape of a friction disk on the transient temperature field in the engagement process of aviation wet friction clutch, a transient thermal analysis model of friction clutch was established, and the application method of thermal boundary conditions, including the calculation of convective heat transfer coefficient and heat flux density, was studied. The transient heat loading process was established by the partition method of friction disk and steel disk. The temperature characteristics of wet clutch friction pairs with different groove shapes during the engagement process were analyzed and tested on an SAE#2 testing machine. Results show that when the clutch is engaged, the temperature of the friction pair composed of two-way parallel groove, three-way parallel groove, and waffle groove friction disk increases continuously at first and finally decreases slightly; the highest temperature of the friction disk and steel disk is at the ring near the outer ring of the friction disk;and the waffle groove friction disk is more suitable for aviation wet friction clutch.

Nonlinear dynamic analysis of an external gear system with meshing beyond pitch point

He-yun Bao,Guang-hu Jin,Feng-xia Lu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

A two-dimensional non-linear dynamics model of a gear with meshing beyond pitch point with six degrees has been established, considering time-varying meshing stiffness, time-varying bearing stiffness, time-varying friction, backlash and bearing clearance. Timevarying meshing stiffness is computed by using material mechanics method. The friction coefficient of Coulomb model and the friction coefficient of EHL theory are analyzed and compared in dynamic response. The global bifurcation characteristics caused by input speed, backlash, bearing clearance and damping are investigated. The maximum Lyapunov exponent which leads to chaos characters effect of changing parameters is analyzed. The verification experiment is carried out on the CL-100 test rig. Meshing frequency has main impact on vibration acceleration of ordinary spur gear and double meshing frequency has main impact on vibration acceleration of gear with meshing beyond pitch point. The results show that the gear with meshing beyond is better than ordinary spur gear whether in bifurcation characteristics or in vibration acceleration response.

Temperature impact analysis of star gear bearing inner ring based on under-race lubrication passage

He-yun Bao,Chun-lei Wang,Feng-xia Lu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

In order to reduce the inner ring temperature and the oil consumption, temperature impact of star gear bearing inner ring based on under-race lubrication passage is analyzed, the flow and temperature fields of the inner ring are simulated using the realizable k-ɛ turbulence model based on the computational fluid dynamics (CFD) method, and experimental verification is performed. The results indicate that adding annular grooves to the star gear cylindrical roller bearing has a significant impact in reducing the temperature of the inner ring, and annular grooves with different cross-sectional sizes have different impacts in reducing the temperature of the inner ring. When the cross-sectional area of the annular grooves is 5 × 1.5 mm, the temperatures of the inner raceway of the left and right bearing decrease from 123.95 and 111.98 °C to 104.3 and 101.4 °C, respectively.

Calculation method of radial displacement in the engaging process of wet friction clutch

He-yun Bao,Xiang Li,Wei Huang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.9

The radial vibration of the wet friction clutch has a certain influence on the engagement characteristics during the engagement process, and this influence cannot be ignored. This paper takes a variable speed configuration as the research object, establishing a six-degree-of-freedom equivalent bending-torsional vibration model of the variable speed transmission system, and studies the calculation method of the meridional displacement during the engagement process of the clutch. The Runge-Kutta method is used in this paper to solve the dynamic model and analyzes the relationship between the joint state and the radial vibration amplitude. The verified experiment is then conducted. Simulation and test results show the following: the clutch eccentric distance and the radial vibration amplitude, as well as the mass of the driven disc of the clutch and the radial vibration amplitude, all increase. The supporting rigidity of the clutch becomes large, the amplitude of radial vibration becomes small.

In situ Synthesis, Crystal Structure, XPS and Fluorescent Property of a Novel Two-Dimensional Binuclear Copper(I) Tetrazole Complex

Yun-Zhi Tang,Jun Huang,Man Zhou,Yun-Pan Deng,Qing Xu,He-Rui Wen 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

구성주의 이론을 적용한 과학 활동이 유아의 과학적 탐구능력과 과학적 태도에 미치는 효과

윤성혜(Yun Sung He),한미라(Han Mi Ra) 학습자중심교과교육학회 2018 학습자중심교과교육연구 Vol.18 No.23

본 연구의 목적은 누리과정 교사용 지도서의 과학 활동에 구성주의 이론을 적용하여 실시할 때 유아들의 과학적 탐구능력과 과학적 태도에 효과가 있는지를 알아보는 데 있다. 이를 위해 경상남도 C시의 H유치원 만 5세 유아 26명을 실험집단으로, B유치원 만 5세 유아 25명을 비교집단으로 하였다. 이들을 대상으로 2016년 4월 1주 부터 7월 2주까지 총 15주 동안 매주 2회 정도 과학활동을 실시하였으며, 과학적 탐구능력과 과학적 태도에 대한 사전 및 사후 검사를 시행하였다. 연구 결과 구성주의 이론을 적용하여 과학활동을 실시했던 실험집단이 지도서의 과학활동을 그대로 실시했던 비교집단에 비해 과학적 탐구능력과 과학적 태도에서 모두 효과가 있었다. 이를 볼 때 누리과정의 자연탐구영역에서 구현하고자 하는 구성주의 과학을 교사들 이 가능한 명확하게 이해하고 보다 쉽게 실행할 수 있도록 교사용 지도서의 과학활동에 대한 변화가 필요하다고 본다. The purpose of this study was to examine whether the science activities set forth in the Nuri course manual for teachers applied with the constructivist theory are effective for children s scientific inquiry ability and attitudes when the activities are executed by the children. To that end, 26 children aged 5 years attending H kindergarten in C city in Gyeongsangnam-do were assigned to an experimental group and 25 children aged 5 years attending B kindergarten in the same city were assigned to a comparison group. The children executed science activities about two times per week for a total of 15 weeks from the first week of April to the second week of July 2016 and the children s scientific inquiry ability and scientific attitudes were tested before and after the execution of activities. The results of the study indicated that the experimental group that executed the science activities applied with the constructivist theory was affected more by the activities in terms of both scientific inquiry ability and scientific attitudes compared to the comparison group that executed the science activities set forth in the manual for teachers as they were. Given the foregoing, the science activities set forth in the manual for teachers should be reviewed to modify and supplement or reorganize them so that teachers can more clearly understand the constructivist science intended to be implemented in the nature inquiry area of the Nuri course and implement it more easily.