5,192 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
Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin Torque
The current-induced resonant excitation of a magnetic vortex core is
investigated by means of analytical and micromagnetic calculations. We find
that the radius and the phase shift of the resonant motion are not correctly
described by the analytical equations because of the dynamic distortion of a
vortex core. In contrast, the initial tilting angle of a vortex core is free
from the distortion and determined by the nonadiabaticity of the spin torque.
It is insensitive to experimentally uncontrollable current-induced in-plane
Oersted field. We propose that a time-resolved imaging of the very initial
trajectory of a core is essential to experimentally estimate the
nonadiabaticity.Comment: 4 pages, 4 figure
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
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Sustainable Conservation of a Difficult Heritage in South Korea: Mapping the Conservation Resources of Sorok-do Island, Hansen’s Disease Site
South Korea’s Sorok-do island bears witness to the 100-year history of the Sorok-do hospital and the village for Hansen’s disease (leprosy) patients. All the facilities of Sorok-do were established by the Japanese imperial authorities, and the collective memories of social isolation and discrimination against Hansen’s disease patients were deeply embedded in this island during the colonial and post-colonial periods. Despite changing perceptions toward the conservation of the island’s history since the 1990s, the island’s deep collective memory remains at risk due to the increasing number of incoming settlers and the shrinking number of Hansen’s disease patients since the opening of the Sorok Bridge in 2009. Taking into consideration the historical lack of critical engagement with difficult heritage conservation in South Korea, this paper introduces a novel approach to sustainable conservation, using as a case study the Sorok-do island. We collected data using archival research, participant observation and semi-structured in-depth interviews, and analyzed them by using a position-mapping method. This paper examines the island’s multifaceted, shifting processes within its history, urban structure, and changing social meanings, and offers a new set of criteria for long-term strategies that will ensure both tangible and intangible types of conservation resources.</jats:p
Genome sequence of the chromate-resistant bacterium Leucobacter salsicius type strain M1-8T
Leucobacter salsicius M1-8(T) is a member of the Microbacteriaceae family within the class Actinomycetales. This strain is a Gram-positive, rod-shaped bacterium and was previously isolated from a Korean fermented food. Most members of the genus Leucobacter are chromate-resistant and this feature could be exploited in biotechnological applications. However, the genus Leucobacter is poorly characterized at the genome level, despite its potential importance. Thus, the present study determined the features of Leucobacter salsicius M1-8(T), as well as its genome sequence and annotation. The genome comprised 3,185,418 bp with a G+C content of 64.5%, which included 2,865 protein-coding genes and 68 RNA genes. This strain possessed two predicted genes associated with chromate resistance, which might facilitate its growth in heavy metal-rich environments.
The Rhizome Mixture of Anemarrhena asphodeloides
We investigated the effect of DWac on the gut microbiota composition in mice with 2,3,6-trinitrobenzenesulfonic acid- (TNBS-) induced colitis. Treatment with DWac restored TNBS-disturbed gut microbiota composition and attenuated TNBS-induced colitis. Moreover, we examined the effect of DWac in mice with mesalazine-resistant colitis (MRC). Intrarectal injection of TNBS in MRC mice caused severe colitis, as well as colon shortening, edema, and increased myeloperoxidase activity. Treatment with mesalazine (30 mg/kg) did not attenuate TNBS-induced colitis in MRC mice, whereas treatment with DWac (30 mg/kg) significantly attenuated TNBS-induced colitis. Moreover, treatment with the mixture of mesalazine (15 mg/kg) and DWac (15 mg/kg) additively attenuated colitis in MRC mice. Treatment with DWac and its mixture with mesalazine inhibited TNBS-induced activation of NF-κB and expression of M1 macrophage markers but increased TNBS-suppressed expression of M2 macrophage markers. Furthermore, these inhibited TNBS-induced T-bet, RORγt, TNF-α, and IL-17 expression but increased TNBS-suppressed Foxp3 and IL-10 expression. However, Th2 cell differentiation and GATA3 and IL-5 expression were not affected. These findings suggest that DWac can ameliorate MRC by increasing the polarization of M2 macrophage and correcting the disturbance of gut microbiota and Th1/Th17/Treg, as well as additively attenuating MRC along with mesalazine
On the dynamics of a quadruped robot model with impedance control: Self-stabilizing high speed trot-running and period-doubling bifurcations
The MIT Cheetah demonstrated a stable 6 m/s trot gait in the sagittal plane utilizing the self-stable characteristics of locomotion. This paper presents a numerical analysis of the behavior of a quadruped robot model with the proposed controller. We first demonstrate the existence of periodic trot gaits at various speeds and examine local orbital stability of each trajectory using Poincar`e map analysis. Beyond the local stability, we additionally demonstrate the stability of the model against large initial perturbations. Stability of trot gaits at a wide range of speed enables gradual acceleration demonstrated in this paper and a real machine. This simulation study also suggests the upper limit of the command speed that ensures stable steady-state running. As we increase the command speed, we observe series of period-doubling bifurcations, which suggests presence of chaotic dynamics beyond a certain level of command speed. Extension of this simulation analysis will provide useful guidelines for searching control parameters to further improve the system performance.United States. Defense Advanced Research Projects Agency. Maximum Mobility and Manipulation (M3) Progra
Image Captioning with Very Scarce Supervised Data: Adversarial Semi-Supervised Learning Approach
Constructing an organized dataset comprised of a large number of images and
several captions for each image is a laborious task, which requires vast human
effort. On the other hand, collecting a large number of images and sentences
separately may be immensely easier. In this paper, we develop a novel
data-efficient semi-supervised framework for training an image captioning
model. We leverage massive unpaired image and caption data by learning to
associate them. To this end, our proposed semi-supervised learning method
assigns pseudo-labels to unpaired samples via Generative Adversarial Networks
to learn the joint distribution of image and caption. To evaluate, we construct
scarcely-paired COCO dataset, a modified version of MS COCO caption dataset.
The empirical results show the effectiveness of our method compared to several
strong baselines, especially when the amount of the paired samples are scarce.Comment: EMNLP 2019. Project page :
https://sites.google.com/view/emnlp19scarcecaptio
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