• Journal of Korean Biological Nursing Science
• /
• 제13권2호
• /
• pp.179-184
• /
• 2011

Purpose: The purpose of this study was to examine the effect of short-term undernutrition on muscle weight and Type I and II fiber cross-sectional area of hindlimb muscles in undernourished rats. Methods: Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The undernourished (UN) group (n=9) and the control (C) group (n=9). A control group was allowed to have water and pellet ad libitum for 5 days. Undernutrition was induced by providing 32% of total intake of the control group for 5 days. Body weight of two groups and food intake of the control group were measured every day. At 6 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles, and liver were dissected. Body weight, food intake, muscle weight, liver weight and cross-sectional area were determined. Results: The UN group at 6 days after undernutrition showed significant decreases, as compared to the control group in body weight, liver weight, muscle weight of soleus, plantaris, and gastrocnemius, and Type I fiber cross-sectional area of soleus and gastrocnemius muscles and Type II fiber cross-sectional area of plantaris and gastrocnemius muscles. Conclusion: Hindlimb muscle atrophy occurs from the short-term undernutrition.

• Journal of Korean Biological Nursing Science
• /
• 제13권1호
• /
• pp.1-7
• /
• 2011

Purpose: The purpose of this study was to compare the hypertrophic effects of low-intensity exercise on weight, myofibrillar protein content and Type I, II fiber cross-sectional area of hindlimb muscles of rats between every other day exercise and every day exercise. Methods: Adult male Sprague-Dawley rats were assigned to 1 of 3 groups: control group (C, n=6), experimental group 1 (E1, n=7) and experimental group 2 (E2, n=7). Rats in E1 group had 7 sessions (every other day) and those in E2 group had 14 sessions (every day) of exercise in which they ran on a treadmill for 30 min/day at 10 m/min. Results: Muscle weight, cross-sectional area of type I fiber and myofibrillar protein content of soleus and myofibrillar protein content of plantaris in E1 group, and myofibrillar protein content of soleus and cross-sectional area of type I fiber of plantaris in E2 group were greater than those in C group. Cross-sectional area of type I fiber of soleus of E1 group was higher than E2 group while cross-sectional area of type I fiber of plantaris of E2 group was higher than E1 group. Conclusion: Hypertrophy of hindlimb muscles occurs from every other day exercise similar to every day exercise.

• 대한간호학회지
• /
• 제26권2호
• /
• pp.271-280
• /
• 1996

The purpose of this study was to determine the effect of periodic walking during hindlimb suspension on the mass, relative weight, fiber type distribution and cross-sectional area of Type I and II fibers in the developing Type II plantaris muscle. To examine the effectiveness of periodic walking on mass and fiber size, the hindlimbs of young female Wistar rats were suspended (HS group) and half of these rats walked on a treadmill for 45 min／day(15 min every 4 hours) at 5 meters／min at a 15 degree grade(HS-W group) After seven days of hindlimb suspension, the plantaris muscle wet weight was 28.40％ significantly smaller（P＜0.005） and relative plantaris muscle weight was 26.97％ smaller compared with those of control rats（P＜0.05）. The plantaris muscle wet weight and the relative plantaris muscle weight increased by 46.60％ and 49.23％ respectively with periodic walking, moreover. the plantaris muscle wet weight and the relative plantaris muscle weight of the HS-W rats recovered to the level of the control rats. No change was observed in fiber type percentage of the developing plantaris muscle following one week of hindlimb suspension or periodic walking during hindlimb suspension. Type I and II fiber cross-sectional areas of the developing plantaris muscle were 42.51％ and 43. 68％ lower in the HS group than in the control group（p＜0.0001）, Type I and II fiber cross-sectional areas of the developing plantaris were 30.82％ and 45.97％ greater in the HS-W group than in the HS group（p＜0.0001）, whereas Type I and II fiber cross-sectional area of HS-W group were less than those of the control group（P＜0.0001） The results suggest that periodic walking can attenuate developing plantaris muscle atrophy induced by hindlimb suspension.

• Journal of Korean Biological Nursing Science
• /
• 제10권1호
• /
• pp.88-95
• /
• 2008

Purpose: The purpose of this study was to examine the effect of neuropathic pain by peripheral nerve injury on mass and Type I and II fiber cross-sectional areas on hindlimb muscles of the neuropathic pain model rat. Method: Adult male Sprague-Dawley rats (body weight 200-220 g) were assigned to one of two groups: a neuropathic pain group (n=7) that had a ligation of the left L5 spinal nerve, a control group (n=5), a naive rat without any procedures. Withdrawal threshold, activity, body weight and food intake were measured daily. At 8 days after neuropathic pain, all rats were anesthetized and the soleus and plantaris muscles were dissected from the both hindlimbs. Body weight, food intake, muscle weight and Type I and II fiber cross-sectional area of the dissected muscles were determined. Result: The neuropathic pain group showed a significant decreases (p<.05) as compared with the control rats, in diet intake, body weight, muscle weight and Type II fiber cross-sectional area of the left (affected side) soleus and plantaris muscles, and the right (unaffected side) muscle weight of plantaris and Type II fiber cross-sectional area of the soleus muscle. Conclusion: The hindlimb muscle atrophy occurs in both affected and unaffected side due to neuropathic pain by the peripheral nerve injury. The hindlimb muscle atrophy of the affected side is more pronounced than that of the unaffected side.

• 대한간호학회지
• /
• 제25권2호
• /
• pp.193-209
• /
• 1995

The purpose of this study was to determine the effect of intermittent low - intensity, short duration exercise during hindlimb suspension on the mass, relative weight, myofibrillar protein content, cross-sectional area of Type I and Type II fibers and SDH activity in Type II(plantaris) muscle. To examine the effectiveness of intermittent low-intensity, short duration exercise on mass, myofibrillar protein content and fiber size, the hindlimbs of adult female Wistar rats were suspended(HS) and half of these rats walked on a treadmill for 45 min/day(9 min every 2h) at 5m /min and a 15$^{\circ}$grade (HS-EX). Plantaris wet weight was 19.67% significantly smaller(p<0.005) and relative plantaris weight was 6.25% smaller compared with those of control rats following seven days of hindlimb suspension. Plantaris wet weight and relative plantaris weight increased by 27.66%, 12.22% each through intermit-tent exercise during hindlimb suspension(p<0.005, p<0.05), moreover, plantaris wet weight and relative plantaris weight of the HS-EX rats were similar to those of control rats. Soleus wet weight and relative soleus weight decreased significantly by 31% and 22.0% in the HS rats(p<0.05). Soleus wet weight and relative soleus weight increased by 10.41%, 25.64% respectively through intermittent ex-ercise during hindlimb suspension, furthermore, soleus wet weight and relative weight of the HS-EX rats were closer to those of control rats. Myofibrillar protein content of plantaris and soleus decreased significantly by 51.49%, 59.65% each, following seven days of hindlimb suspension (p<0.005) Myofibrillar protein content of plantaris and soleus increased by 51.79%, 75.47% each with significance through intermittent exercise during hindlimb suspension(p<0.005). Myofibrillar protein content of plantaris and soleus in HS-EX rats was smaller than that of control rats. No change was observed in fiber type percentage following 1 week of hindlimb suspension or exercise during hindlimb suspension. The type I fiber cross-sectional area of both soleus and plantaris muscle was 18.72% and 41.07% lower in the HS than that of the controls (p<0.05, p<.001), that of both muscles was 6.60% and 29. 3％ greater in the HS-EX than that of the HS rats. HS plus intermittent low- intensity short duration exercise resulted in Type I fiber cross-sectional area closer to the controls. Type II fiber cross-sectional area of both plantaris and soleus muscle was 22.45% and 22.58% sl nailer in the HS than in the controls, that of both muschles in the HS-EX was 14.10%, 5.78% greater than HS. Intermittent exercise during hindlimb suspension resulted in Type I, II fiber cross-sectional area closer to the control value. There was no change in SDH activity following 1week of hindlimb suspension or exercise during hindlimb suspension in the plantaris muscle. The results suggest that intermittent low intensity short duration exercise can ameliorate Type II muscular atrophy Induced by hindlimb suspension.

• 대한인간공학회지
• /
• 제27권2호
• /
• pp.1-7
• /
• 2008

This study quantified 7 trunk muscles' physiological cross-sectional areas (PCSAs) and developed prediction equations for the physiological cross-sectional area as a function of anthropometic variables for Korean people. Nine females and nine males were participated in the magnetic resonance imaging (MRI) scans approximately from S1 through T8. Muscle fiber angle corrected cross-sectional areas (anatomical cross sectional areas: ACSAs) were recorded at each vertebral level and maximum value of ACSAs were determined as physiological cross sectional area (PCSA). There was a significant gender difference in PCSAs of all muscles (p<0.05). Stepwise linear regression techniques using anthropometric measures (e.g., height, weight, trunk depths and widths) as independent variables were conducted to develop prediction equations for the PCSA for each muscle. For males, six muscles' significant prediction equations (p<0.05) were developed except quadratus lumborum. For females, three prediction equations were developed for psoas, quadratus lumborum, and erector spinae muscles (p<0.05).

• 대한간호학회지
• /
• 제37권1호
• /
• pp.81-90
• /
• 2007

Purpose: The purpose of this study was to examine the effects of daily exercise before steroid treatment on mass, the type I and II fiber cross-sectional area, and myofibrillar protein content of hindlimb muscles in a rat model. Method: Adult male Sprague-Dawley rats were randomly assigned to one of three groups: a control group(n=10) that had a normal saline injection for 7days, a steroid group(n=10) that had a steroid injection for 7days, and an exercise-steroid group(n=10) that ran on the treadmill for 7days before a steroid treatment. Body weight and food intake were measured every day. At 15 days all rats were anesthetized and the soleus, plantaris and gastrocnemius muscles were dissected. Result: The exercise-steroid group showed significant increases as compared with the steroid group in body weight, muscle weight of the soleus and gastrocnemius, type II muscle fiber cross-sectional area of plantaris, and myofibrillar protein content of the soleus, plantaris, and gastrocnemius. As compared with the control group, the steroid group showed significant decreases in body weight and diet intake, muscle weight, the type II fiber cross-sectional area and myofibrillar protein content of the soleus, plantaris, and gastrocnemius muscles. Conclusion: Daily exercise before steroid treatment attenuates hindlimb muscle atrophy, with type II muscle changes more apparent than type I muscle changes.

• 수산해양기술연구
• /
• 제54권1호
• /
• pp.25-31
• /
• 2018

In this study, the differences of holding power according to the shape and weight distribution of concrete weight used in shellfish shell fishery were investigated through the experiments. To investigate the differences in shape, five bar-shaped concrete weights with the same length and different cross-sectional shapes were produced. The sectional shape of each weight was square, triangle, circle, small cross, and large cross (SQ, TR, CI, CR-S, CR-L). Ten rectangular parallelepiped weights with different bottom area and cross-sectional area were produced. To investigate the differences by the weight distribution, the holding power on the square model (SQ) with six 50 g weights at different positions was investigated. All the holding power was obtained by measuring the tensile force generated when the concrete weight was pulled at a constant speed on the sand. As a result, there were no differences in holding power between the ten rectangular weights. However, the experiment on weights with different cross-sectional shapes showed differences in holding power. The holding power was higher in the order of CR-L > CR-S > CI > TR > SQ. In the weight distribution test, the holding power was higher as the front side of the weight was heavier. Generally, the frictional force is the same even if the shape is different, when two objects have the same value in the weight and the roughness. On the other hand, it seems to have a large impact when the shape of the bottom is deformed in the course of pulling the object. Particularly, the larger the degree of protrusion like cruciform weights, the more the holding power increased while deeply digging the bottom. It is also likely that the holding power increases as the front weight increases.

• 대한토목학회논문집
• /
• 제13권4호
• /
• pp.27-37
• /
• 1993

응력 및 변위제약 하에 뼈대구조물의 초소중량설계를 얻기 위한 효율적인 방법을 제안한다. 주문제작이 빈번히 이루어지는 공학설계의 응용을 위해 다음의 5가지 단면형상을 고려하였다.(rectangular형, frame형, tube형, channel형 그리고 I형). 최적화 과정의 효율성을 증진시키기 위해 구조응답량(절점력, 변위)을 단면성질에 대해 1차 Taylor급수 전개했고 반면에 단면치수를 설계변수로 고려하였다. 제안된 방법의 효율성과 신뢰성을 보이기 위해 수치예를 통해 다른 방법에 의한 결과와 비교하였다. 그 결과 구조해석의 수를 크게 감소시킬 수 있었으며 뼈대구조물의 최적화에 매우 효율적으로 적용될 수 있음을 알게 되었다.

• 한국조사연구학회지:조사연구
• /
• 제12권3호
• /
• pp.173-186
• /
• 2011

본 연구에서는 2003년 시작된 한국청소년패널조사 중학교 2학년 패널자료 분석을 위해 필수적인 각 연도별 횡단면, 종단면 가중치 산출방안을 소개하고 있다. 패널 모집 당시 추출된 표본이 대표하는 모집단의 종단면적 변화 분석을 위한 종단면 가중치는 로지스틱 회귀분석을 이용한 무응답 보정과 사후 층화를 통해 산출되었으며, 조사 연도의 표본 대응 모집단 분석을 위해 필수적인 횡단면 가중치는 전년도 대비 응답률과 사후 층화를 통해 산출되었다.