64 research outputs found
Flexible and Shape-Reconfigurable Hydrogel Interlocking Adhesives for High Adhesion in Wet Environments Based on Anisotropic Swelling of Hydrogel Microstructures
This study presents wet-responsive, shape-reconfigurable, and flexible hydrogel adhesives that exhibit strong adhesion under wet environments based on reversible interlocking between reconfigurable microhook arrays. The experimental investigation on the swelling behavior and structural characterization of the hydrogel microstructures reveal that the microhook arrays undergo anisotropic swelling and shape transformation upon contact with water. The adhesion between the interlocked microhook arrays is greatly enhanced under wet conditions because of the hydration-triggered shape reconfiguration of the hydrogel microstructures. Furthermore, wet adhesion monotonically increases with water-exposure time. A maximum adhesion force of 79.9 N cm-2 in the shear direction is obtained with the hydrogel microhook array after 20 h of swelling, which is 732.3% greater than that under dry conditions (i.e., 9.6 N cm-2). A simple theoretical model is developed to describe the measured adhesion forces. The results are in good agreement with the experimental data
Single quantum dot selection and tailor-made photonic device integration using nanoscale focus pinspot
Among the diverse platforms of quantum light sources, epitaxially grown
semiconductor quantum dots (QDs) are one of the most attractive workhorses for
realizing various quantum photonic technologies owing to their outstanding
brightness and scalability. There exist various material systems for these QDs
based on their appropriate emission bandwidth; however, only a few material
systems have successfully grown single or low-density QDs, which are essential
for quantum light sources. In most other material systems, it is difficult to
realize low-density QDs, and the mesa-etching process is usually undergone in
order to reduce their density. Nevertheless, the etching process irreversibly
destroys the medium near the QD, which is detrimental to in-plane device
integration. In this study, we apply a nondestructive luminescence picking
method termed as nanoscale focus pinspot (NFP) using helium ion microscopy to
reduce the luminous QD density while retaining the surrounding medium. Given
that the NFP can precisely manipulate the luminescence at nanoscale resolution,
a photonic device can be deterministically fabricated on the target QD matched
from both spatial and spectral points of view. After applying the NFP, we
extract only a single QD emission out of the high-density ensemble QD emission.
Moreover, the photonic structure of a circular Bragg reflector is
deterministically integrated with the selected QD, and the extraction
efficiency of the QD emission has been improved 27 times. Furthermore, this
technique does not destroy the medium and only controls the luminescence.
Hence, it is highly applicable to various photonic structures, including
photonic waveguides or photonic crystal cavities regardless of their materials.Comment: 16 pages, 5 figure
Mammary gland tumors in a male Cocker Spaniel
Background
Mammary gland tumors are the most common tumors in sexually intact female dogs; however, they are rare in male dogs. This study was conducted to investigate the relationship between sexual hormones and mammary gland tumors in a male dog.
Case presentation
A 13-year-old, intact male Cocker Spaniel presented to the Veterinary Teaching Hospital of Kangwon National University, Republic of Korea, with an acute right ruptured caudal abdominal mass. Physical examination revealed a 14 × 14 cm ruptured mass in the right caudal abdomen, as well as a 1.5 × 1.5 cm mass in the first right mammary gland. The estrogen and progesterone concentrations in serum were within normal levels. Total mastectomy was done on the right side mammary glands. Following surgery, the site was fully recovered; however, a mass that had grown to 2 × 2 cm was found in the left fifth mammary gland and a testis tumor was also found over the period of 4 months. Mastectomy was performed on the left caudal mammary gland and castration was also performed. After the final surgery, the dog fully recovered. Histopathological examination of all three masses revealed high grade mammary adenocarcinoma in the mammary gland and the testis was diagnosed as Leydig cell adenoma. Immunohistochemical analysis revealed that the estrogen and progesterone receptors were expressed on limited cells in mammary and testis tumors.
Conclusion
The results of this study suggest that mammary tumors and testes tumors can occur in male dogs without relationship to female sexual hormone
Mesoscopic transport in KSTAR plasmas: avalanches and the staircase
The self-organization is one of the most interesting phenomena in the
non-equilibrium complex system, generating ordered structures of different
sizes and durations. In tokamak plasmas, various self-organized phenomena have
been reported, and two of them, coexisting in the near-marginal (interaction
dominant) regime, are avalanches and the staircase. Avalanches
mean the ballistic flux propagation event through successive interactions as it
propagates, and the staircase means a globally ordered pattern of
self-organized zonal flow layers. Various models have been suggested to
understand their characteristics and relation, but experimental researches have
been mostly limited to the demonstration of their existence. Here we report
detailed analyses of their dynamics and statistics and explain their relation.
Avalanches influence the formation and the width distribution of the staircase, while the staircase confines avalanches within its
mesoscopic width until dissipated or penetrated. Our perspective to consider
them the self-organization phenomena enhances our fundamental understanding of
them as well as links our findings with the self-organization of mesoscopic
structures in various complex systems
Exploring Determinants of Tourists’ Ethical Behavior Intention for Sustainable Tourism: The Role of Both Pursuit of Happiness and Normative Goal Framing
This study explored variables that determine outbound Korean tourists’ ethical behavior intention during their visits of Southeast Asian countries and analyzed the influencing relationship between them in an integrated manner. The results from the partial least squares path modeling of the R statistical program demonstrate that the pursuit of hedonic and eudaimonic motives plays a positive role in activating normative goal framing which supports tourists’ ethical behavior intention. This study therefore empirically proved the important roles of both the pursuit of happiness in daily life and normative goal framing as motivators that enhance ethical behavior intention at tourist destinations to achieve the goal of sustainable tourism after the pandemic
Exploring Determinants of Tourists’ Ethical Behavior Intention for Sustainable Tourism: The Role of Both Pursuit of Happiness and Normative Goal Framing
This study explored variables that determine outbound Korean tourists’ ethical behavior intention during their visits of Southeast Asian countries and analyzed the influencing relationship between them in an integrated manner. The results from the partial least squares path modeling of the R statistical program demonstrate that the pursuit of hedonic and eudaimonic motives plays a positive role in activating normative goal framing which supports tourists’ ethical behavior intention. This study therefore empirically proved the important roles of both the pursuit of happiness in daily life and normative goal framing as motivators that enhance ethical behavior intention at tourist destinations to achieve the goal of sustainable tourism after the pandemic
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