Evacuation safety effects of a lightweight elevator-type evacuation device using carbon material: Focus on plantar pressure and muscle strength.

BACKGROUND: Elevator-type evacuation devices have proven to be feasible in high-rise buildings through studies on safety performance and evacuation time. However, there is a lack of research on safety using biosignal analysis in the elderly population. OBJECTIVE: A carbon material is used in this study to reduce the weight of an evacuation elevator. The impact on the human body is evaluated by conducting a satisfaction survey involving elderly and youth groups and quantitatively analyzing biological signals, including electromyography (EMG) and plantar pressure, during five repeated uses of the proposed device. METHODS: The study involves 12 healthy adults in their 20s and 20 elderly individuals with no experience in using an evacuation elevator. The EMG and left and right plantar pressures are analyzed to evaluate the physical factors affected by repeated use. RESULTS: The experiment results showed that the normalization of EMG to maximum voluntary contraction showed a significant decrease with repeated use, especially in the right tibialis anterior muscle. Moreover, plantar pressure shows a significant difference, which decreased with repetition, and the left and right balance gradually tilted to the left. CONCLUSION: This suggests that with more repeated use, muscle tension decreases owing to adaptation, resulting in lower muscle activity and plantar pressure. Particularly, the tibialis anterior muscle experiences significant muscle activity, indicating increased load, but without any apparent danger. In the future, it will be necessary to evaluate elevators for disabled individuals.

Preliminary study on verifying the detection of gait intention based on knee joint anterior displacement of gait slopes.

This study investigated the feasibility of the Infrared (IR) sensor-based walking aids for detecting the gait intention. To compensate for the defects of Force Sensing Resistors (FSRs) or force sensors, such as the velocity control problem on gait slopes, we used IR sensors to investigate knee joint anterior displacement in order to recognize the gait intention. We also measure leg muscle activities and foot pressure, in order to verify our investigation. We placed two IR sensors on the rollator center to sense left and right leg walking intentions. We took EMG signals of four leg muscles, and analyzed them. Foot pressure analysis parameters were the measured force and mean pressure. We conducted experiments on twenty young healthy adults. The results show that knee joint anterior displacement increases according to gait slope and velocity. We confirm similar results of knee joint anterior displacement through the IR sensors.

Analysis of basal physical fitness and lumbar muscle function according to indoor horse riding exercise.

The aim of this study is to verify the effect of indoor horse riding exercise on basal physical exercise and lumbar muscular function. The subjects included were 20 healthy females, who participated in the horse riding exercise using SRider (Rider Co. & ChonbuK National Univ, Korea) for 30 minutes per day, 3 days per week, over a period of 8 weeks. The subjects were divided into 4 groups as follows, with 10 subjects in each group: Postural Balance Exercise mode (PBE), Abdomen Exercise mode (ADE), Whole body Exercise mode (WBE), and Multiple Exercise (MTE). Isokinetic muscular function test was performed before and after the horse riding exercise, to assess the effect of horse riding on basal physical exercise and lumbar muscular function. The test result on basal physical exercise and isokinetic muscular function showed improvements with variable degree in the back muscle strength, maximum joint torque, total work, and muscular acceleration time. The result signifies that the horse riding is an antagonistic exercise mainly performed on waist and abdomen area, and the machine induces persistent muscle contraction and causes myotonic induction enhancing the muscle strength. Indoor horse riding exercise proved its effectiveness for senior or the disabled people who need muscle exercises but have difficulties performing outdoor activities.

Taurine prevents hypertension and increases exercise capacity in rats with fructose-induced hypertension.

BACKGROUND: Fructose-induced hypertension was used to test the hypothesis that taurine supplementation and/or exercise can prevent hypertension and increase exercise capacity. METHODS: Five groups of 15 Sprague-Dawley rats were allocated and designated as control, high fructose-fed (fructose), high fructose-fed plus exercise (FE), high fructose-fed plus 2% taurine supplement (FT) and high fructose-fed plus 2% taurine supplement and exercise (FET) groups. Noninvasive systolic blood pressure (SBP) was recorded weekly and invasive arterial blood pressure (ABP) was recorded at the end of the 4-week trial. Three consecutive swimming tests were performed in the selected rats from each group and the plasma biomarkers were measured in the remaining rats. RESULTS: Noninvasive SBP differed significantly (P < 0.001) from week 3, both noninvasive and invasive ABP increased significantly (P < 0.001), and exercise capacity significantly decreased (P < 0.001) in the fructose group compared with the control group. The individual effects of swimming and taurine supplementation were incapable of preventing the development of hypertension and SBP significantly (P < 0.001) increased in the FE and FT groups; exercise capacity in those groups remained similar to control. The combined effects of exercise and taurine alleviated hypertension and significantly increased exercise capacity in the FET group. Insulin resistance increased significantly and plasma nitric oxide (NO) decreased significantly in the F, FE, and FT groups. Both parameters remained similar to control values in the FET group with an increasing antioxidant activity. CONCLUSION: Taurine supplementation in combination with exercise prevents hypertension and increases exercise capacity by possibly antioxidation and maintaining NO concentrations.

Improvement of gas transfer by hemosome.

Intravascular oxidation is a respiratory assist method used to treat acute respiratory distress syndrome (ARDS). However intravascular oxidation through higher gas exchange is needed for successful clinical applications. In this study, an attempt was made to improve the gas exchange of an intravascular lung assist device by decreasing the level of damage to the blood through the microencapsulation of hemoglobin. The results showed that a hemosome 0.8 microm in diameter could be produced by microencapsulating the hemoglobin extracted from fresh bovine blood with the phospholipids extracted from egg yolk. The oxygen saturation curve of hemosome was S-shaped, which is similar to that found in normal blood, and the P50 was 24 mmHg. The oxygen saturation in the mixed solution of hemosome and blood at a 1:4 (v/v%) ratio was similar to that of normal blood. The gas exchange of the blood-hemosome mixed solution was more effective than whole blood. Therefore, the hemosome solution is expected to improve oxygen transfer.

Nitrite-induced methemoglobinaemia affects blood ionized and total magnesium level by hydrolysis of plasma adenosine triphosphate in rat.

The objective of this study was to evaluate the effects of sodium nitrite (NaNO(2))-induced methemoglobinaemia on plasma ATP (adenosine triphosphate) and corresponding changes of blood-ionized magnesium (iMg(2+)) as well as total magnesium (tMg(2+)) in a time-dependent manner. This study was performed on male Sprague-Dawley rats to which NaNO(2) was injected (10 mg/kg i.p.) to induce methemoglobinaemia. Methemoglobin (MetHb) in blood was measured before (0 min.) and after 10, 30, 60 and 120 min. of NaNO(2) injection. At respective time points, the tMg(2+), blood ions and gases were measured by atomic absorption spectrometry and ion selective electrode, respectively. Haematological parameters were checked by automatic blood cell count, and blood films were observed under light microscope. Plasma ATP was measured by bioluminescence assay using a luminometer, and plasma proteins were measured by an automatic analyser. Blood cell count (RBC, WBC and platelet), haematocrit, and haemoglobin were found to be decreased with the advancement of MetHb concentration. With the gradual increase of MetHb concentration, the plasma ATP decreased and blood iMg(2+) and plasma tMg(2+) increased significantly as time passed by in comparison with the pre-drug values. A significant decrease of the ratio of ionized calcium to iMg(2+), Na(+) and increase of K(+) was observed. In conclusion, NaNO(2)-induced methemoglobinaemia is a cause of hydrolysis of plasma ATP which is responsible for the increase of blood iMg(2+) and plasma tMg(2+) in rats.

The antioxidant, taurine reduced lipopolysaccharide (LPS)-induced generation of ROS, and activation of MAPKs and Bax in cultured pneumocytes.

Lipopolysaccharide (LPS) can cause damage to the epithelia of the respiratory tract. However, taurine can protect the lung tissue from such oxidant-induced inflammation. This study examined the effects of a LPS treatment on the intracellular calcium levels ([Ca(2+)]i) as well as the specific mechanisms of LPS-induced cell death in pneumocytes. In addition, the effects of taurine on the LPS-induced increase in the accumulation of reactive oxygen species (ROS) in pneumocytes were investigated. The [Ca(2+)]i in cultured pneumocytes was determined using microfluorescence techniques. The level of activation of the mitogen-activated protein kinases (MAPKs) and Bax protein were measured by Western blotting. LPS at 10 and 100 ng/ml induced cell death and decreased the viability of MRC-5 cells. Moreover, the intracellular Ca(2+) and ROS levels were increased by LPS. The LPS treatment led to the phosphorylation of ERK1/2, JNK and the activation of Bax. A pretreatment with 20 mM taurine reduced the LPS-induced production of ROS and MARK activity. These results show that a LPS treatment induces cell death in MRC-5 cells by increasing the intracellular ROS and Ca(2+) levels. The increase in the intracellular level of ROS promotes MAPKs activation and Bax translocation. Overall, LPS induces lung cell death by activating MAPKs. Furthermore, taurine decreased the LPS-induced generation of ROS and activation of MAPK and Bax.

Taurine increases cell proliferation and generates an increase in [Mg2+]i accompanied by ERK 1/2 activation in human osteoblast cells.

Taurine has been reported to influence bone metabolism, and its specific transport system, the taurine transporter, is expressed in osteoblasts. The mean [Mg2+]i was 0.51+/-0.01 mM in normal culture media. Taurine caused an increase in [Mg(2+)]i by 0.72+/-0.04 mM in human osteoblast (HOB) cells. This increment in [Mg2+]i was inhibited significantly by PD98059, nifedipine, lidocaine, and imipramine. Taurine was also shown to stimulate the activation of ERK 1/2. This taurine-stimulated ERK 1/2 activation was inhibited by PD98059. In the present study, taurine was shown to increase cell proliferation and generate an increase in [Mg2+]i accompanied by ERK 1/2 activation in HOB cells.

Experimental studies on the training of postural control using an unstable platform.

We performed experimental studies on the training of postural control using a training system which consists of an unstable platform, a computer, a computer interface, a monitoring device, and training programs. Using this system with the training programs that we have developed, we performed a variety of experiments of training the abilities of postural control of subjects. To evaluate the effects of the training, the parameters on how long a subject can maintain a focus on a target, the mean absolute deviation of the trace, and the fatigue of the muscles in lower limbs were measured. The experimental results showed that the training system can improve the ability of postural control of the subject. Therefore, the training system could be applied to clinical rehabilitation training for posture control as a new balance training system.