المؤلفون: Young-Geun Park, Yong Won Kwon, Chin Su Koh, Enji Kim, Dong Ha Lee, Sumin Kim, Jongmin Mun, Yeon-Mi Hong, Sanghoon Lee, Ju-Young Kim, Jae-Hyun Lee, Hyun Ho Jung, Jinwoo Cheon, Jin Woo Chang, Jang-Ung Park

المصدر: Nature Communications, Vol 15, Iss 1, Pp 1-15 (2024)

مصطلحات موضوعية: Science

الوصف: Abstract Current soft neural probes are still operated by bulky, rigid electronics mounted to a body, which deteriorate the integrity of the device to biological systems and restrict the free behavior of a subject. We report a soft, conformable neural interface system that can monitor the single-unit activities of neurons with long-term stability. The system implements soft neural probes in the brain, and their subsidiary electronics which are directly printed on the cranial surface. The high-resolution printing of liquid metals forms soft neural probes with a cellular-scale diameter and adaptable lengths. Also, the printing of liquid metal-based circuits and interconnections along the curvature of the cranium enables the conformal integration of electronics to the body, and the cranial circuit delivers neural signals to a smartphone wirelessly. In the in-vivo studies using mice, the system demonstrates long-term recording (33 weeks) of neural activities in arbitrary brain regions. In T-maze behavioral tests, the system shows the behavior-induced activation of neurons in multiple brain regions.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2041-1723Test

الوصول الحر: https://doaj.org/article/9ab20659da3344c6a7a291cfe3133b44Test

المؤلفون: Ji-Youn Kwak, Ji-Young Jeong, Ye-Pil Kwon, Dong-Hyun Seo, Chung-Mo Kang, Dong-Hyeon Kim, Jun Sae Han, Eun-Ji Gwak, Doo-Sun Choi, Ju-Young Kim, Tae-Jin Je, Eun-chae Jeon

المصدر: Scientific Reports, Vol 13, Iss 1, Pp 1-11 (2023)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract There has been significant research focused on the development of stretchable materials that can provide a large area with minimal material usage for use in solar cells and displays. However, most materials exhibit perpendicular shrinkage when stretched, which is particularly problematic for polymer-based substrates commonly used in stretchable devices. To address this issue, biaxial strain-controlled substrates have been proposed as a solution to increase device efficiency and conserve material resources. In this study, we present the design and fabrication of a biaxial strain-controlled substrate with a re-entrant honeycomb structure and a negative Poisson’s ratio. Using a precisely machined mold with a shape error of less than 0.15%, we successfully fabricated polydimethylsiloxane substrates with a 500 μm thick re-entrant honeycomb structure, resulting in a 19.1% reduction in perpendicular shrinkage. This improvement translates to a potential increase in device efficiency by 9.44% and an 8.60% reduction in material usage for substrate fabrication. We demonstrate that this design and manufacturing method can be applied to the fabrication of efficient stretchable devices, such as solar cells and displays.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/2c365aabe95543758dbc607b81cefdc5Test

المؤلفون: Ji-Woo Gu, Jae-Young Bae, Guangzhe Li, Hae Won Hwang, So-Hyeon Lee, Sung-Geun Choi, Ju-Young Kim, Myoung-Ryul Ok, Yu-Chan Kim, Seung-Kyun Kang

المصدر: Journal of Magnesium and Alloys, Vol 11, Iss 9, Pp 3241-3254 (2023)

مصطلحات موضوعية: Biodegradable alloy, Mg–3Zn binary alloy, Solid-solution thin film electrode, Biodegradable conductor, Transient electronics, Mining engineering. Metallurgy, TN1-997

الوصف: Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg–Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg–3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg–3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg–3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2213956723001299Test; https://doaj.org/toc/2213-9567Test

الوصول الحر: https://doaj.org/article/6d608bc15edc42679db8c6a2cd57785fTest

المؤلفون: Han-Mo Yang, Joonoh Kim, Baek-Kyung Kim, Hyun Ju Seo, Ju-Young Kim, Joo-Eun Lee, Jaewon Lee, Jihye You, Sooryeonhwa Jin, Yoo-Wook Kwon, Hyun-Duk Jang, Hyo-Soo Kim

المصدر: Research, Vol 6 (2024)

مصطلحات موضوعية: Science

الوصف: Resistin plays an important role in the pathophysiology of obesity-mediated insulin resistance in mice. However, the biology of resistin in humans is quite different from that in rodents. Therefore, the association between resistin and insulin resistance remains unclear in humans. Here, we tested whether and how the endocannabinoid system (ECS) control circulating peripheral blood mononuclear cells (PBMCs) that produce resistin and infiltrate into the adipose tissue, heart, skeletal muscle, and liver, resulting in inflammation and insulin resistance. Using human PBMCs, we investigate whether the ECS is connected to human resistin. To test whether the ECS regulates inflammation and insulin resistance in vivo, we used 2 animal models such as “humanized” nonobese diabetic/Shi-severe combined immunodeficient interleukin-2Rγ (null) (NOG) mice and “humanized” resistin mouse models, which mimic human body. In human atheromatous plaques, cannabinoid 1 receptor (CB1R)-positive macrophage was colocalized with the resistin expression. In addition, resistin was exclusively expressed in the sorted CB1R-positive cells from human PBMCs. In CB1R-positive cells, endocannabinoid ligands induced resistin expression via the p38–Sp1 pathway. In both mouse models, a high-fat diet increased the accumulation of endocannabinoid ligands in adipose tissue, which recruited the CB1R-positive cells that secrete resistin, leading to adipose tissue inflammation and insulin resistance. This phenomenon was suppressed by CB1R blockade or in resistin knockout mice. Interestingly, this process was accompanied by mitochondrial change that was induced by resistin treatment. These results provide important insights into the ECS–resistin axis, leading to the development of metabolic diseases. Therefore, the regulation of resistin via the CB1R could be a potential therapeutic strategy for cardiometabolic diseases.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2639-5274Test

الوصول الحر: https://doaj.org/article/9f2b5de1784b4bea8fe9c6db86a7114bTest

المؤلفون: Han-Mo Yang, Joo-Eun Lee, Ju-Young Kim, Jihye You, Joonoh Kim, Hak Seung Lee, Hee Min Yoo, Min Gyu Kong, Jung-Kyu Han, Hyun-Jai Cho, Kyung Woo Park, Hyun-Jae Kang, Bon-Kwon Koo, Young-Bae Park, Hyo-Soo Kim

المصدر: Biomaterials Research, Vol 27, Iss 1, Pp 1-17 (2023)

مصطلحات موضوعية: Coronary artery spasm, Vasospastic angina, Calcium, Ex vivo diagnosis, Medical technology, R855-855.5

الوصف: Abstract Background Although vasospastic angina (VSA) is known to be caused by coronary artery spasm, no study has fully elucidated the exact underlying mechanism. Moreover, in order to confirm VSA, patients should undergo invasive coronary angiography with spasm provocation test. Herein, we investigated the pathophysiology of VSA using peripheral blood-derived induced pluripotent stem cells (iPSCs) and developed an ex vivo diagnostic method for VSA. Methods and results With 10 mL of peripheral blood from patients with VSA, we generated iPSCs and differentiated these iPSCs into target cells. As compared with vascular smooth muscle cells (VSMCs) differentiated from iPSCs of normal subjects with negative provocation test, VSA patient-specific iPSCs-derived VSMCs showed very strong contraction in response to stimulants. Moreover, VSA patient-specific VSMCs exhibited a significant increase in stimulation-induced intracellular calcium efflux (Changes in the relative fluorescence unit [ΔF/F]; Control group vs. VSA group, 2.89 ± 0.34 vs. 10.32 ± 0.51, p

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2055-7124Test

الوصول الحر: https://doaj.org/article/eab3758d7e894c6388147a35d28e32cdTest

المؤلفون: Hangeul Kim, Gyeong‐Seok Hwang, Sukbin Lee, Ju‐Young Kim

المصدر: Advanced Electronic Materials, Vol 9, Iss 7, Pp n/a-n/a (2023)

مصطلحات موضوعية: amorphous oxides, elastic behavior, micromechanical modeling, stretchability, tensile test, Electric apparatus and materials. Electric circuits. Electric networks, TK452-454.4, Physics, QC1-999

الوصف: Abstract Aligned wavy‐structured thermally grown silicon dioxide films are fabricated for stretchable encapsulation films. Uniaxial stretchability is investigated with micromechanics modeling, which can elucidate the stretchability arising from the wavy structure and the properties of the materials. The wavy‐structured films with optimum combinations of film thickness and wavy structure show 20.1% of uniaxial stretchability and 1.11 × 10−6 g m−2 day−1 of water vapor transmission rate (WVTR), simultaneously. It shows highly reliable barrier properties even after 1000 stretching cycles at 90% of their stretchability.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2199-160XTest

الوصول الحر: https://doaj.org/article/9f615c97ca57455c97f1c45692623f71Test

المؤلفون: Ju-Young Kim, Yoon-Hee Cheon, Sung-Jun Ahn, Sung Chul Kwak, Chong Hyuk Chung, Chang Hoon Lee, Myeung Su Lee

المصدر: BMC Complementary Medicine and Therapies, Vol 22, Iss 1, Pp 1-13 (2022)

مصطلحات موضوعية: Collagen-induced arthritis model, Harpagoside, Inflammation, Osteoclasts, Rheumatoid arthritis, Other systems of medicine, RZ201-999

الوصف: Abstract Background Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes local bone erosion and systemic osteoporosis. Harpagoside (HAR), an iridoid glycoside, has various pharmacological effects on pain, arthritis, and inflammation. Our previous study suggests that HAR is more deeply involved in the mechanism of bone loss caused by inflammatory stimuli than hormonal changes. Here, we identified the local and systemic bone loss inhibitory effects of HAR on RA and its intracellular mechanisms using a type 2 collagen-induced arthritis (CIA) mouse model. Methods The anti-osteoporosis and anti-arthritic effects of HAR were evaluated on bone marrow macrophage in vitro and CIA in mice in vivo by obtaining clinical scores, measuring hind paw thickness and inflammatory cytokine levels, micro-CT and histopathological assessments, and cell-based assay. Results HAR markedly reduced the clinical score and incidence rate of CIA in both the prevention and therapy groups. Histological analysis demonstrated that HAR locally ameliorated the destruction of bone and cartilage and the formation of pannus. In this process, HAR decreased the expression of inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-6, and IL-1β in the serum of CIA mice. Additionally, HAR downregulated the expression of receptor activator of nuclear factor-κB ligand and upregulated that of osteoprotegerin. HAR suppressed systemic bone loss by inhibiting osteoclast differentiation and osteoclast marker gene expression in a CIA mouse model. Conclusions Taken together, these findings show the beneficial effect of HAR on local symptoms and systemic bone erosion triggered by inflammatory arthritis.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2662-7671Test

الوصول الحر: https://doaj.org/article/952b31e3b57b4be8a871243c2ef0ca90Test

المؤلفون: Jung-Hyun Kim, MD, PhD, Hyesung Lee, PhD, So-Young Park, MD, PhD, Ju-Young Kim, MD, Sun Hee Choi, MD, PhD, Hyouk-Soo Kwon, MD, PhD, Woo-Jung Song, MD, PhD, Sae-Hoon Kim, MD, PhD, Jinho Yu, MD, PhD, Dae Jin Song, MD, PhD, You Sook Cho, MD, PhD, Dae Hyun Lim, MD, PhD, Young-Joo Cho, MD, PhD, Suk-Il Chang, MD, PhD, Tae-Bum Kim, MD, PhD

المصدر: World Allergy Organization Journal, Vol 16, Iss 4, Pp 100768- (2023)

مصطلحات موضوعية: Asthma, Claims data, Severity, Immunologic diseases. Allergy, RC581-607

الوصف: Background: There has been a concerning increase in the prevalence and socioeconomic burden of asthma in Korea. Korea's National Health Insurance System (NHIS) covers insurance payment and claims management for all Koreans. Using National Health Insurance Sharing Service (NHISS) claims data. This study aimed to investigate patterns of healthcare utilization and direct cost in patients with asthma over a 10-year period. Methods: In this retrospective population-based study, we examined NHISS claims records between July 2005 and June 2016 and investigated healthcare utilization among patients with asthma based on age group and severity of disease (non-severe asthma [NSA] and severe asthma [SA]). Results: From 2006 to 2015, the total number of patients with asthma in Korea steadily increased from 743 968 to 2 286 309, with a corresponding increase in prevalence from 1.62% to 4.74%. The proportion of patients with SA decreased from 3.16% in 2006 to 1.56% in 2015; the proportion was consistently higher in men than in women. In addition, patients with SA had a higher cost per outpatient visit than patients with NSA, and the number of outpatient visits per year increased. The inhaled corticosteroid (ICS) prescription rate among patients with asthma decreased from 22.9% in 2006 to 15.7% in 2015. Furthermore, for a period of 10 years, more than 40% of patients with SA have been prescribed short-acting β-2 agonists (SABAs). Conclusions: Although patients with SA comprised a small proportion of patients with asthma, they incurred greater medical costs per person. The pharmaceutical prescription pattern indicated a lack of ICS-based prescriptions and frequent SABA prescriptions.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S1939455123000285Test; https://doaj.org/toc/1939-4551Test

الوصول الحر: https://doaj.org/article/a82e59f1db2a49d59df2d74dcdceff4fTest

المؤلفون: Eugene Lee, Ju-young Kim, Tae-Kyung Kim, Seo-Young Park, Gun-Il Im

المصدر: Cell Death Discovery, Vol 7, Iss 1, Pp 1-13 (2021)

مصطلحات موضوعية: Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282, Cytology, QH573-671

الوصف: Abstract While bone has an inherent capacity to heal itself, it is very difficult to reconstitute large bone defects. Regenerative medicine, including stem cell implantation, has been studied as a novel solution to treat these conditions. However, when the local vascularity is impaired, even the transplanted cells undergo rapid necrosis before differentiating into osteoblasts and regenerating bone. Thus, to increase the effectiveness of stem cell transplantation, it is quintessential to improve the viability of the implanted stem cells. In this study, given that the regulation of glucose may hold the key to stem cell survival and osteogenic differentiation, we investigated the molecules that can replace the effect of glucose under ischemic microenvironment of stem cell transplantation in large bone defects. By analyzing differentially expressed genes under glucose-supplemented and glucose-free conditions, we explored markers such as methyltransferase-like protein 7A (METTL7A) that are potentially related to cell survival and osteogenic differentiation. Overexpression of METTL7A gene enhanced the osteogenic differentiation and viability of human bone marrow stem cells (hBMSCs) in glucose-free conditions. When the in vivo effectiveness of METTL7A-transfected cells in bone regeneration was explored in a rat model of critical-size segmental long-bone defect, METTL7A-transfected hBMSCs showed significantly better regenerative potential than the control vector-transfected hBMSCs. DNA methylation profiles showed a large difference in methylation status of genes related to osteogenesis and cell survival between hBMSCs cultured in glucose-supplemented condition and those cultured in glucose-free condition. Interestingly, METTL7A overexpression altered the methylation status of related genes to favor osteogenic differentiation and cell survival. In conclusion, it is suggested that a novel factor METTL7A enhances osteogenic differentiation and viability of hBMSCs by regulating the methylation status of genes related to osteogenesis or survival.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2058-7716Test

الوصول الحر: https://doaj.org/article/dbf163274a8f47ff9361aa2ebaa11495Test

المؤلفون: Seungjun Choo, Faizan Ejaz, Hyejin Ju, Fredrick Kim, Jungsoo Lee, Seong Eun Yang, Gyeonghun Kim, Hangeul Kim, Seungki Jo, Seongheon Baek, Soyoung Cho, Keonkuk Kim, Ju-Young Kim, Sangjoon Ahn, Han Gi Chae, Beomjin Kwon, Jae Sung Son

المصدر: Nature Communications, Vol 12, Iss 1, Pp 1-11 (2021)

مصطلحات موضوعية: Science

الوصف: The geometrical design of thermoelectric legs in modules is key for sustainable power generation but can be hardly achieved by traditional fabrication process. Here, the authors develop an extrusion-based 3D printing process of Cu2Se thermoelectric materials for efficient power generation.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2041-1723Test

الوصول الحر: https://doaj.org/article/b99be82131ba419594bc196e7ac1ed7fTest