• Title/Summary/Keyword: Failure analysis

Search Result 8,271, Processing Time 0.035 seconds

Effects of High Glucose on Na,K-ATPase and Na/glucose Cotransporter Activity in Primary Rabbit Kidney Proximal Tubule Cells

  • Han, Ho-Jae
    • The Korean Journal of Physiology
    • /
    • v.29 no.1
    • /
    • pp.69-80
    • /
    • 1995
  • Renal proximal tubular hypertrophy and hyperfunction are known to be early manifestations of experimental and human diabetes. As the hypertrophy and hyperfunction have been suggested to be central components in the progression to renal failure, an understanding of their underlying causes is potentially important for the development of therapy. A primary rabbit kidney proximal tubule cell culture system was utilized to evaluate the possibility that the renal proximal tubular hypertrophy and hyperfunction observed in vivo in diabetes mellitus, can be attributed to effects of elevated glucose levels on membrane transport systems. Primary cultures of rabbit proximal tubules, which achieved confluence at 10 days, exhibited brush-border characteristics typical of proximal tubular cells. Northern analysis indicated $2.2{\sim}2.3$ and 2.0 kb Na/glucose cotransporter RNA species appeared in fresh and cultured proximal tubule cells after confluence, repectively. The cultured cells showed reduced Na/glucose cotransporter activity compared to fresh proximal tubules. Primary cultured proximal tubule cells incubated in medium containing 20 mM glucose have reduced ${\alpha}-MG$ transport compared to cells grown in 5 mM glucose. In the proximal tubule cultures incubated in medium containing 5 mM or 20 mM glucose, phlorizin at 0.5 mM inhibited 0.5 mM ${\alpha}-MG$ uptake by 84.35% or 91.85%, respectively. The uptake of 0.5 mM ${\alpha}-MG$ was similarly inhibited by 0.1 mM ouabain (41.97% or 48.03% inhibition was observed, respectively). In addition, ${\alpha}-MG$ uptake was inhibited to a greater extent when $Na^{+}$ was omitted from the uptake buffer (81.86% or 86.73% inhibition was observed, respectively). In cell homogenates derived from the primary cells grown in 5 mM glucose medium, the specific activity of the Na/K-ATPase $(6.17{\pm}1.27\;{\mu}mole\;Pi/mg\;protein/hr)$ was 1.56 fold lower than the values in cell homogenates treated with 360 mg/dl D-glucose, 20 mM $(9.67{\pm}1.22\;{\mu}mole\;Pi/mg\;protein/hr)$. Total $Rb^{+}$ uptake occurred at a significantly higher rate (1.60 fold increase) in primary cultured rabbit kidney proximal tubule cell monolayers incubated in 20 mM glucose medium $(10.48{\pm}2.45\;nM/mg\;protein/min)$ as compared with parallel cultures in 5 mM glucose medium. $Rb^{+}$ uptake rate in 5 mM glucose medium was reduced by 28% when the cultures were incubated with 1 mM ouabain. The increase of the $Rb^{+}$ uptake by rabbit kidney proximal tubule cells in 20 mM glucose could be attributed primarily to an increase in the rate of ouabain-sensitive $Rb^{+}$ uptake $(5\;mM\;to\;20\;mM;\;4.68{\pm}0.85\;to\;8.38{\pm}1.37\;nM/mg\;protein/min)$. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Nafglucose cotransport system is inhibited.

  • PDF

Exploratory study of Cultural Education in Home Economics Education (가정과교육에서의 문화교육에 대한 탐색적 연구)

  • Kim Eun-Jeung
    • Journal of Korean Home Economics Education Association
    • /
    • v.18 no.2 s.40
    • /
    • pp.1-13
    • /
    • 2006
  • The main purpose of this thesis is to research various theories in Cultural Education. It is to rebuild the value of home economics, and to demonstrate its potential to bring out a true human being. Until now, home economics education had been focused on developing ability to solve problems, only to fail us in training students to have ability to cope with different conditions in daily life by themselves. With the society rapidly changing, such a temporizing education system would lose its value immediately, and the identity of home economics education is at stake today. The present situation is resulted from the failure in approaching the culture education properly. With the fact that the elements of home economics are culture themselves. the failures in organizing and teaching the subject would urge us to rearrange curriculum of home economics. We need to bear in mind that the curriculum of home economics cannot contain every cultural value. A careful consideration is necessary in order to include the essence of the culture at the minimum quantity. Through analyzing different types of theories and methods of education in Cultural Education, this research is aimed at reviewing home economics education with its concept. Further study in the future should be proceeded with more comprehensive researches on instruction and learning methods with Cultural Education perspective, based on the analysis.

  • PDF

A Study on the Sufficiency of Anticipated Effect of Order Communication System Introduced to Medium-Sized Hospitals (Focused on the case of S Hospital) (중소병원의 처방전달시스템 도입효과분석에 관한 연구 (S병원의 사례를 중심으로))

  • Hong, Suk-Won;Jung, Key-Sun;Choi, Sung-Woo
    • Korea Journal of Hospital Management
    • /
    • v.7 no.4
    • /
    • pp.172-192
    • /
    • 2002
  • The purpose of this study is to ascertain whether the effect of introduction of OCS(Order Communication System) to the hospital is satisfied or not comparing the anticipated effect with the actual effect. For this purpose, a domestic hospital which has introduced and has been operating OCS for several years was chosen. Based on the internal data of S Hospital prepared before introducing OCS, researcher has analyzed the basic direction, design standard and status of operation after the introduction of OCS, etc. After analyzing the status of operations of several departments using OCS and interviewing with the chiefs of pertinent departments, a survey form was designed. Actual survey and interviews were conducted by the researcher for weeks to know whether doctors, nurses, medical technicians and clerks of the patient management dept. were satisfied with OCS and to find if they have any recommendations to improve OCS. Based on the analysis of survey, the effect of OCS was evaluated whether it has satisfied the anticipated effectiveness. For the question if they feel convenient in using OCS, doctors, nursing staffs in charge of ward and the staffs of billing dept. has answered that they were all satisfied(100%). The answers for the same question were relatively high in the case of nurses in charge of outpatient and staffs of radiography. Of course, there have been some nurses and staffs who complained for the inconvenience. However, overall satisfaction was high on the average. Some common problems occurred after the introduction of OCS were frequent errors due to instability of OCS system, paralysis of function of hardware on data back-up system and redundant investment due to erroneous choice of DB program in setting DB. It was also pointed out that lack of computer education and low participation of medical staffs has resulted in failure of developing effective software. As a result, it has lowered the efficiency of OCS. For example, some works have to be done by hands even after OCS. Based on the result of this research, recommendations to maximize the effect of OCS were presented as follows. First, strong leadership of CEO and active cooperation of doctors are mandatory. Second, all the process of hospital work should be analyzed and be redesigned in more efficient ways. Third, OCS should be designed to be user-based system which can be used efficiently by all staffs of the hospital. Forth, prior to the operation of OCS, proper tests of the program and trainings of the pertinent staff are required. Fifth, prior to the selection of hardware, BMT(Bench Marking Test) should be conducted. Sixth, before introducing OCS, staffs in charge of OCS should visit many hospitals operating the OCS system and take their cases into account.

  • PDF

Drug Use Evaluation of Antihypertensive Agents by JNC VI Guidelines (고혈압 치료 지침 Vl에 의한 항고혈압제의 사용평가)

  • Kim, Kyung Hwa;Lee, Suk Hyang
    • Korean Journal of Clinical Pharmacy
    • /
    • v.12 no.1
    • /
    • pp.29-38
    • /
    • 2002
  • Hypertension is an important public health problem because it increases the risk of stroke, angina, myocardial infarction, heart failure, and end-stage renal disease. If it is not actively treated, morbidity and mortality increase with hypertension-induced complications and quality of life decreases. This study was to evaluate the use of antihypertensive drugs and blood pressure changes and to compare algorithms chosen (or the 1st and 2nd line therapy of hypertension based on the JNC VI recommendations. The medical charts of 222 patients with essential hypertension at St. Vincent's Hospital in Suwon from January 1997 to January 2000 were reviewed retrospectively. Data collection and analysis included baseline BP underlying diseases and complications, administered antihypertensives, BP changes, changes of antihypertensive regimen, and adverse effects with treatments. As results, the higher BP the patients had, the more frequent they had target organ damages and clinical cardiovascular diseases. Mean duration to reduce blood pressure less than 140/90 mmHg was 8 weeks in $85.3\%$ of the patients. The rate of control in BP was $82.4\%$ at 6 months. The major antihypertensive drugs prescribed were calcium channel blockers $(61.8\%)$ , ACE inhibitors $(19.1\%),\;\beta-blockers\;(13.7\%)$ and diuretics $(5.3\%)$ as the 1st-line monotherapy. The methods of treatment used as the 1st-line therapy were monotherapy$(59\%)$ and combination therapy $(41\%)$. Blood pressure change was significantly greater for combination therapy than monotherapy$(-26.2\pm21.4\;vs.\;-18.56\pm16.7$ mmHg for systolic blood pressure; P<0.003, $-16.9\pm13.2\;vs.\;-9.2\pm12.8$ mmHg for diastolic blood pressure; p<0.001). When blood pressure was not completely controlled with the first antihypertensive selected, the 2nd line therapy had 4 options: addition of 2nd agent from different class; $66.2\%$, substitution with another drug, $21.9\%$ increase dose $11.9\%$ continue first regimen $27.9\%$ Calcium channel blockers were the most frequently prescribed agents. This was not comparable to the JNC VI guideline which recommended diuretics and $\beta-blockers$ for the 1st-line therapy. Most of patients achieved the goal BP and maintained it until 6 months, but the remaining patients should be controlled more tightly to improve their BP with combination of life style modification, patient education, and pharmacotherapy.

  • PDF

Family Support: a Review of Nursing Literature on its Trends and Implementations (가족지지개념을 다룬 국내 간호연구 분석)

  • Park, Shin-Ae;Kang, Kyung-Sook;Jeong, Mi-Young;Cha, Nam-Hyun;Kim, Soon-Young
    • Research in Community and Public Health Nursing
    • /
    • v.12 no.3
    • /
    • pp.639-646
    • /
    • 2001
  • The purpose of this study is to analyze the trend of nursing research related to family support and to provide an effective direction for future research by conducting a review of the Korean nursing literature from 1980 to 2000. A total of 73 studies were analyzed with the following results. 1) The number of studies related to family support has been rapidly increasing since 1984, and 77% of those were conducted in the 1990s. 48 studies, 65% of those analyzed. were degree-based research including 4 doctoral theses (4%) and 45 master's theses (62%). 2) Based on the objective frame of study types developed by Lee et al. (991), the types of studies were analyzed: 56 studies, 76.6% of those reviewed, belonged to factor-relating: 9 studies (12.4%) belonged to factor-isolating: 7 studies (9.6%) belonged to situation-producing: and only 1 study (1.4%) belonged to situation-relating research, respectively. 3) In terms of research design, most studies of analyzed (90.4%) were conducted by non-experimental design, and 7 studies (9.6%) were conducted by experimental design. But, qualitative research related to family support was not found. 4) In terms of research subjects, target populations of experimental studies were patients with arthritis, mental disorder, tuberculosis, coronary artery disease and hypertension. In correlational studies, 51 studies, 69.9% of those analyzed, were conducted to patients with renal failure, cancer and hemiplegia, and 5 studies (6.8%) were conducted to aged people and adolescents. 5) Study concepts used in correlational studies were quality of life, anxiety and depression, self-esteem, hope, role behavior, compliance and self-care activities. The quality of life was most often used among studies with 12.5% of those analyzed. 6) Nursing interventions, including diet therapy, family involving education and supportive care, used in experimental studies mostly showed positive effects on client involvement and home health improvement. However, the nursing interventions of mental health rehabilitation and resistance exercise showed neutral and negative results. The findings of this study provide evidence that more empirical research including experimental or qualitative studies should be conducted actively to improve nursing practice related to family support. Also, to promote more diverse nursing interventions, a family assessment tool especially for Korean families needs to be developed.

  • PDF

Renewable Electricity Promotion Policy in Korea - Feature and Challenges through the Comparative Analysis of EU and Japanese Policy - (한국의 신재생에너지전력 지원정책 - EU와 일본의 제도 비교분석을 통한 지원정책의 현상과 과제 -)

  • Lee, Soo-Cheol;Park, Seung-Joon
    • Journal of Environmental Policy
    • /
    • v.7 no.4
    • /
    • pp.1-34
    • /
    • 2008
  • It is recognized that RPS(Renewable Portfolio Standard) and FIT(Feed-in Tariff) are two main policy instruments to promote Renewable Electricity(RE). The Korean Government announced in 2008 that RE promotion scheme will be changed to RPS from current FIT system in 2012. But we believe RPS is inferior to FIT for promoting less developed technologies such as photovoltaics or wind power. This is because the achievement of RE promotion in countries adopting RPS is markedly worse than that in European counties or Janpan adopting FIT. If the policy change is inevitable, when considering the lessons from Japan's failure as well as supporting the less developed technologies, it is recommended that either the market should be divided into several technology and scale categories, or more RPS-Credit per kWh should be assigned to the photovoltaic and wind power than instead of letting the all technologies compete in the "open category". It is also recommended that (1) Renewable Energy Promotion Fund(tentative name) based on a part of current energy related tax revenue should be introduced, or (2) cost of supporting the Renewable Electricity should automatically be transferred into the electricity bill of electricity consumers following the German System.

  • PDF

Failure Analysis of Corroded Coating Materials by Acoustic Emission (음향방출법에 의한 용사코팅 피막부식재의 파손 해석)

  • KIM GUI-SHIK;HYUN CHANG-HAE;HONG YONG-UI;SHON CHANG-HWAN
    • Journal of Ocean Engineering and Technology
    • /
    • v.19 no.5 s.66
    • /
    • pp.43-49
    • /
    • 2005
  • This paper is to investigate the effect of corrosion by acoustic emission method in tensile loading and the adhesiveness between substrate and coating layer. The powders used are Zn and Amdry625, respectively. They are coated on brass alloy substrate. AE signals of Zn and Amdry625 coating layer increase drastically in strain $2\%$. However, those of Zn specimen have more than those of Amdry625 specimen. When the specimens executed the corrosion test under $3.5\%$ NaCl solution for 500, 1000 hours, the salt solution penetrated into the surface of the substrate through the pores of the coating layer. As a result, corrosion production formed on the surface of the substrate. The adhesiveness between coating layers is weakened by the polarization and corrosion itself. The AE event, count, and energy of corroded coating specimens decrease, compared to specimens without corrosion. The results are summarized as follows : 1. In the tensile tests, the time that it took to start and develop the cracks and exfoliations between the surface of the substrates and the plasma spray coatings were different according to the type of plasma sprayed material, which are Zn and Amdry625. These phenomena were obvious at the strain rate 1 to $5\%$, and few available data were found after that stage. 2. The specimens with Zn coating showed the characteristics of crack, according to the changes of the tensile strength applied on the substrates while those with Amdry625 showed exfoliation as a result of low adaptation to the tensile strength. 3. The anti-corrosion specimens showed that the adhesive properties between the substrate and the plasma spray coating were strong in the order of Zn, Amdry. It showed that Corroded specimens cracked or exfoliated easily, even with the small energy, because those had a comparatively weakened adhesive property, due to corrosion. 4. Zn specimen showed no corrosion phenomena on the surface of the substrates, because they had the function of sacrifice anode however, Amdry625 specimen showed the corrosion, because it did not have that function.

Influence of Alumina Slurry Composition on Mechanical Properties of Green Tapes (알루미나 슬러리 조성에 따른 그린 테이프의 기계적 특성)

  • Lee, Myung-Hyun;Park, Il-Seok;Kim, Dae-Joon;Lee, Deuk-Yong
    • Journal of the Korean Ceramic Society
    • /
    • v.39 no.9
    • /
    • pp.871-877
    • /
    • 2002
  • Alumina slurriers, having various amount of alumina and ratio of organic additives, were prepared for tape casting. The relative viscosities were compared to investigate influence of composition on stability of the slurry and plotted as a function of powder fraction. They raised with increasing powder fraction of slurries, revealing a exponential function curve, which means that stability of slurry was not affected by amount and composition of organic additives. Cast green tapes were tested under tensile condition at room temperature. The increase in alumina ratio and binder ratio was found to decrease strain to failure of green tapes from 363% to 45% and from 68% to 25%, respectively. Tensile strength of green tapes increased abruptly with increasing alumina ratio, which showed its maximum at 1 MPa. On other hand, Tensile strength increased continuously from 0.5 MPa to 4 MPa with increasing binder ratio. Mechanical properties of them were affected seriously and lost their properties by elevating temperature from 20$^{\circ}C$ to 80$^{\circ}C$.

New Suggestion of Effective Moment of Inertia for Beams Reinforced with the Deformed GFRP Rebar (이형 GFRP Rebar로 보강된 보의 유효단면이차모멘트 산정식 제안)

  • Sim, Jong-Sung;Oh, Hong-Seob;Ju, Min-Kwan;Lim, Jun-Hyun
    • Journal of the Korea Concrete Institute
    • /
    • v.20 no.2
    • /
    • pp.185-191
    • /
    • 2008
  • To fundamentally solve the problem of deterioration of concrete structures, it has been researched that the high durable concrete structure reinforced with the FRP rebar can be one of major solution to the newly-developed concrete structure. FRP rebar has lots of advantages such as non-corrosive, high performance and light weight against the conventional steel rebar. Among these kinds of FRP rebars, GFRP rebar has usually been considered as the best reinforcement because of its economic point of view. Even though the material capacity of the GFRP rebar was already investigated, there are some problems such as low modulus of elastic that will be cause for degrade of the serviceability of flexural concrete member reinforced with the GFRP rebar. Thus, the deflection characteristics of the GFRP rebar reinforced concrete structure should be considered then investigated. In this study, ACI 440 guideline (2003), ISIS Canada Design Manual (2001) and Toutanji et al. (2000) was considered for predicting the moment of inertia of the concrete beam reinforced with the GFRP rebar. And it was also evaluated that load-deflection relationship had a good accordance with the test and analysis result. In the result of this study, it could be estimated that the load-deflection relationship using the suggested equation of moment of inertia in this study indicated better accordance with the test result than that of the others until failure.

A STUDY ON THE SHEAR BOND STRENGTH OF LUTING GLASS IONOMER AND DENTIN TREATED WITH CALCIUM SOLUTION (칼슘수용액으로 처리한 상아질과 합착용 글래스아이오노머의 전단결합강도에 관한 연구)

  • Paik, Young-Girl;Lee, Sung-Bok;Park, Nam-Soo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.34 no.3
    • /
    • pp.593-610
    • /
    • 1996
  • The objective of this paper was to evaluate the shear bond strength of luting glass ionomer cement with defferent calcium based solution treatment on dentin surface. 120 extracted human teeth were classified into 12 group based on presence of smear layer on dentin surface and type of treatment solution. Smear layer remove on dentin surface was done using 6% citric acid for 60 seconds. Five different dentin surface treatment solutions(calcium acetate, calcium carbonate, clacium chlorided, calcium hydroxide, and calcium phosphate) were evaluated in this study. After surface modification, metal ring(inner diameter : 3mm, depth : 1mm) was placed to expose the same dentin surface area and inner space was filled with luting glass ionomer cement according to the recommended procedure for stadard clinical procedure. The shear bond strength of glass ionomer cement was determined after 24 hours. SEM was used for the evaluation of the surface morphologic changes and EDAX analysis was done for determination of the change of the calcium contents of treated dentin. Follwing conclusion can be drawn : 1. In the group of the dentin surface with smear layer, the calcium carbonate solution was the most effective for the increase of the clacium content and the shear bond strength of glass ionomer cement to dentin surfaces. 2. In the group of the calcium carbonate treated dentin with msear layer, the shear bond strength was increased twice compared to the control group and cohesive failure mode was observed. 3. The shear bond strength of cement was increased significantly be the removal of smear layer using 6% citric aicd. However, additional calcium solution treatments were not effective for further bond strength increase. 4. The shear bond strength of cement was significantly improved by both of the removal of smear layer and the calcium solution treatment, and the former was more effective for bond strength improvement. 5. The smear layer removed/calcium solution treated groups showed dentinal tubule obstruction and crystal attachment in SEM evaluation. However, the shear bond strengths of these groups were not increased compared to the smear layer removed/no dentin treatment group.

  • PDF