5,543 research outputs found
Labisia pumila extract protects skin cells from photoaging caused by UVB irradiation
Labisia pumila (Myrsinaceae), known as "Kacip Fatimah," has been used by many generations of Malay women to induce and facilitate child birth as well as a post partum medicine. However, its topical application on skin has not been reported yet. In this study, we have focused on the anti-photoaging effects of L. pumila. Extract of L. pumila was first analyzed for their antioxidant activities using DPPH (2,2-diphenyl-1-picrylhydrazyl) since UV irradiation is a primary cause of reactive oxygen species (ROS) generation in the skin. The 50% free radical scavenging activity (FSC(50)) of L. pumila extract was determined to be 0.006%, which was equal to that produced by 156 microM ascorbic acid. TNF-alpha and cyclooxygenase (COX-2) play a primary role in the inflammation process upon UV irradiation and are known to be stimulated by UVB. Treatment with L. pumila extract markedly inhibited the TNF-alpha production and the expression of COX-2. Decreased collagen synthesis of human fibroblasts by UVB was restored back to normal level after treatment with L. pumila extract. On the other hand, the enhanced MMP-1 expression upon UVB irradiation was down regulated by L. pumila extract in a dose-dependent manner. Furthermore, treatment of normal keratinocytes with L. pumila extract attenuated UVB-induced MMP-9 expression. These results collectively suggest L. pumila extract has tremendous potential as an anti-photoaging cosmetic ingredient
Effect of Aging Time and Retail Displaying Period with a Short-Term Temperature Abuse on Color Stability of Two Beef Muscles
Meat color and tenderness are two most important quality factors affecting consumers’ decision on meat purchasing. Post-mortem meat aging has been widely practiced to improve palatability attributes, but could be adversely related to meat color. In particular, temperature abuse during aging or retail display can negatively affect the color stability of aged meat. The objective of this study was to determine the effect of aging time and short-term temperature abuse during display on color stability of two beef muscles (M. longissimus dorsi, LD and semitendinosus, ST). LD and ST muscles were separated from three beef carcasses, vacuum-packaged and assigned into 4 different aging times (7, 14, 21 and 28 days) at 2ºC. After each assigned aging, each sample was cut into a steak, overwrap packaged with PVC film on a tray, and displayed for 7 days at 2ºC under light. At 4 d display, temperature abuse on displayed muscles was performed by placing packages at 10ºC for 45 min and 20ºC for 15 min (total 1h). Beef aged for 21 and 28d were more sensitive to discoloration induced by temperature abuse. Between two different muscles, ST was rapidly discolored compared to LD. Myoglobin content, non-heme iron content, ferric ion reducing capacity, and lipid oxidation of the steaks after display were determined. Non-heme iron content, ferric ion reducing capacity and lipid oxidation were increasing as the aging time increased. These findings suggest that longer aged beef is more susceptible to discoloration under the temperature abused condition due to reduced antioxidant properties
Effects of muscular response for the intensity of vibratory stimulus applied on the ankle tendon
The present study was conducted to measure the individual threshold value for the somatosensory system of the human body, the thresholds value of vibratory stimulus were assessed through the ascent and descent methods. In the interests of the attainment of this study`s goal, comparing the thresholds value measured and change of state of the muscles when applied on the ankle tendon connected to muscles, changes in threshold measurement accuracy due to the differences in measuring methods were discussed. The experiment was conducted by constructing systems to stimulate somethetic sensibility by vibratory stimulus, ultrasound imaging system and EMG system. Five adult males were involved in this experiment. According to the results of experiments, the threshold value of somatosensory stimulation measured by the ascent method was greater than the threshold values measured by the descent method. And the muscular response to the somatosensory stimulation applied to the tibialis anterior tendon showed a larger rate of change with the ascending stimulus than with the descending stimulus. The results of this study could serve as a basis to discuss the reliability of the measurement method of the human body’s individual threshold value for the somatosensory system through the ascent and descent methods and can be used as reference data for the integration and performance threshold measurement methods
A study on the changes in gait characteristics by applying sub-threshold vibration stimulus in the ankle
This study was conducted to suggest the potential use of a mechanical vibration stimulus in the ankle to correct gait abnormalities. As for the mechanical vibration stimulus, different locations and durations are suggested based on the detection results of real-time gait patterns. 5 young males participated in this study. They were asked to perform assigned gait tasks when either a threshold or sub-threshold stimulus was applied in the tibialis anterior and Achilles tendon. The analysis results of gait cycle and muscle activity showed the changes on gait cycle, the activity pattern of used muscle for gait and the movement pattern of the ankle were observed based on the applied locations of vibration stimulus. Also, the result of sub-threshold stimulus showed similar effects as that of threshold stimulus. As such, the mechanical vibration stimulus was considered to affect gait by being adjusted its characteristics and local stimulus also would affect human body systemically. The result of this study can be used as basic data for the correction of individual’s specific gait abnormality and rehabilitation using vibration stimulus
A study on the change in the characteristics of the gait of elderly people when somatosensory stimulation was applied to their ankle joint
The gait is the most complicated, habitual, and involuntary activity of humans and is a result of the cooperation of the central and peripheral nervous systems that harmoniously mobilize the sensory receptors, nervous system, and muscles. A sensory signal binds to a somatosensory system proprioceptor to obtain information on posture. This study was designed to analyze the change in the characteristics of a gait when stimulation is applied in the somatosensory system that controls the balance of the body. A result of the GRF obtained from the force plate and gyroscope signals from the sensor attached on ankle joint were obtained to compare the change before and after the somatosensory stimulation. The result of this study proved a potential of somatosensory stimulation in improving balance, which could be used in studies on the balance of positions and gait improvement
USCID fourth international conference
Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Since 3000 BC, rice has been the main crop in the Korean Peninsula, and where currently most of the available irrigation water is used to grow paddy rice. Methods for calculating the quantity of irrigation water required developed in the 1990's were compared to quantities measured in the field. The largest difference between calculated and measured quantities occurred in April and May. Based on field data we obtained in the middle part of the Korean Peninsula, significant changes have occurred in rice management, which has changed the amount of irrigation water required. Rice is now transplanted earlier, and duration of the transplanting phase on the regional scale is shorter through mechanization and consolidation of land holdings. These changes need to be taken into account when calculating the quantity of water needed for irrigation
Current-induced domain wall motion in a nanowire with perpendicular magnetic anisotropy
We study theoretically the current-induced magnetic domain wall motion in a
metallic nanowire with perpendicular magnetic anisotropy. The anisotropy can
reduce the critical current density of the domain wall motion. We explain the
reduction mechanism and identify the maximal reduction conditions. This result
facilitates both fundamental studies and device applications of the current-
induced domain wall motion
Numerical Simulations of the Impact and Spreading of a Particulate Drop on a Solid Substrate
We present two-dimensional numerical simulations of the impact and spreading of a droplet containing a number of small particles on a flat solid surface, just after hitting the solid surface, to understand particle effects on spreading dynamics of a particle-laden droplet for the application to the industrial inkjet printing process. The Navier-Stokes equation is solved by a finite-element-based computational scheme that employs the level-set method for the accurate interface description between the drop fluid and air and a fictitious domain method for suspended particles to account for full hydrodynamic interaction. Focusing on the particle effect on droplet spreading and recoil behaviors, we report that suspended particles suppress the droplet oscillation and deformation, by investigating the drop deformations for various Reynolds numbers. This suppressed oscillatory behavior of the particulate droplet has been interpreted with the enhanced energy dissipation due to the presence of particles
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