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排序方式： 共有1275条查询结果，搜索用时 15 毫秒
41.
Sungmin Park Taehee Kim Seongwon Yoon Chang Woo Koh Han Young Woo Hae Jung Son 《Advanced materials (Deerfield Beach, Fla.)》2020,32(51):2002217
Organic solar cells based on bulk heterojunctions (BHJs) are attractive energy-conversion devices that can generate electricity from absorbed sunlight by dissociating excitons and collecting charge carriers. Recent breakthroughs attained by development of nonfullerene acceptors result in significant enhancement in power conversion efficiency (PCEs) exceeding 17%. However, most of researches have focused on pursuing high efficiency of small-area (<1 cm2) unit cells fabricated usually with spin coating. For practical application of organic photovoltaics (OPVs) from lab-scale unit cells to industrial products, it is essential to develop efficient technologies that can extend active area of devices with minimized loss of performance and ensured operational stability. In this progress report, an overview of recent advancements in materials and processing technologies is provided for transitioning from small-area laboratory-scale devices to large-area industrial scale modules. First, development of materials that satisfy requirements of high tolerability in active layer thickness and large-area adaptability is introduced. Second, morphology control using various coating techniques in a large active area is discussed. Third, the recent research progress is also underlined for understanding mechanisms of OPV degradation and studies for improving device long-term stability along with reliable evaluation procedures. 相似文献
42.
Timothy Jee Kam Koh Christopher T. Chan 《Hemodialysis international. International Symposium on Home Hemodialysis》2016,20(3):E10-E13
Adrenal insufficiency is a complication of chronic corticosteroid therapy. Unexplained hypotension may be a manifestation of an adrenal insufficient state in patients with a history of corticosteroid therapy on hemodialysis. We present a series of five cases of patients on nocturnal home hemodialysis with hypotension as the main manifestation of adrenal insufficiency. Unexplained hypotension in patients with a history of corticosteroid therapy should prompt the managing clinician to consider adrenal insufficiency as a possible cause. 相似文献
43.
Srikanth Pedireddy Hiang Kwee Lee Charlynn Sher Lin Koh Joel Ming Rui Tan Weng Weei Tjiu Xing Yi Ling 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(33):4531-4540
Controlling sub‐10 nm ligament sizes and open‐shell structure in nanoporous gold (NPG) to achieve strained lattice is critical in enhancing catalytic activity, but it remains a challenge due to poor control of reaction kinetics in conventional dealloying approach. Herein, a ligament size‐controlled synthesis of open‐shell NPG bowls (NPGB) through hetero‐epitaxial growth of NPGB on AgCl is reported. The ligament size in NPGB is controlled from 6 to 46 nm by varying the hydroquinone to HAuCl4 ratio. The Williamson–Hall analysis demonstrates a higher lattice strain in smaller ligament size. In particular, NPGB with 6 nm (NPGB 6) ligament size possess the highest strain of 15.4 × 10?3, which is nearly twice of conventional 2D NPG sheets (≈8.8 × 10?3). The presence of high surface energy facets in NPGBs is also envisaged. The best electrocatalytic activity toward methanol oxidation is observed in NPGB 6 (27.8 μA μg?1), which is ≈9‐fold and 3‐fold higher than 8 nm solid Au nanoparticles, and conventional NPG sheets. The excellent catalytic activity in NPGB 6 is attributed to the open‐shell structure, lattice strain, and higher electro‐active surface area, allowing efficient exposure of catalytic active sites to facilitate the methanol oxidation. The results offer a potential strategy for designing next generation electrocatalysts. 相似文献
44.
45.
Yukihisa Fujinaga Tadashi Namisaki Yuki Tsuji Junya Suzuki Koji Murata Soichi Takeda Hiroaki Takaya Takashi Inoue Ryuichi Noguchi Yuki Fujimoto Masahide Enomoto Norihisa Nishimura Koh Kitagawa Kosuke Kaji Hideto Kawaratani Takemi Akahane Akira Mitoro Hitoshi Yoshiji 《International journal of molecular sciences》2022,23(17)
Primary biliary cholangitis (PBC) has a wide variation in clinical presentation and course. There is no significant correlation between these symptoms and the disease stage, although patients with more advanced stages generally have more symptoms. It is important to develop biomarkers in order to identify patients with an increased risk of complications and end-stage liver disease. This study investigated surrogate markers for risk estimation of PBC-related complications, including a study population of 77 patients with PBC who underwent liver biopsy and were measured for serum levels of macrophage activation markers, soluble CD163 (sCD163), soluble mannose receptor (sMR), and zonulin. Patients with PBC were divided into symptomatic (Group S, n = 20) and asymptomatic (Group A, n = 57) groups. The correlations of histological stages based on both Scheuer and Nakanuma classifications with the three serum markers were investigated. The Nakanuma classification involves grading for liver fibrosis and bile duct loss. The three biomarkers were assessed for their diagnostic ability to identify patients with PBC having high risk of developing complications. The predictive factors of these complications were examined as well. Group S had significantly higher serum sMR (p = 0.011) and sCD163 (p = 0.048) levels versus Group A. A composite index of sMR and sCD163 measurements had significantly better prediction performance than sCD163 alone (p = 0.012), although not when compared to sMR alone (p = 0.129). Serum sMR was an independent factor for developing complications on both univariate (Odds ratio (OR) = 30.20, 95% confidence interval (95% CI): 3.410–267.0, p = 0.00220), and multivariate (OR = 33.70, 95% CI: 3.6600–311.0, p = 0.0019) analyses. Patients with PBC having sMR of ≥56.6 had a higher incidence of clinical complications versus those with a sMR of <56.6. Serum sMR predicts the development of complications in patients with PBC. sMR plus sCD163 showed better predictive power than either marker alone, although the addition of sCD163 did not improve the predictive power of sMR. Future prospective studies are required in order to validate the findings of the present study. 相似文献
46.
Jin-Ho Park Eun-Byeol Koh Young-Jin Seo Hye-Seong Oh Ju-Yeong Won Sun-Chul Hwang June-Ho Byun 《International journal of molecular sciences》2022,23(22)
Tiron is a potent antioxidant that counters the pathological effects of reactive oxygen species (ROS) production due to oxidative stress in various cell types. We examined the effects of tiron on mitochondrial function and osteoblastic differentiation in human periosteum-derived cells (hPDCs). Tiron increased mitochondrial activity and decreased senescence-associated β-galactosidase activity in hPDCs; however, it had a detrimental effect on osteoblastic differentiation by reducing alkaline phosphatase (ALP) activity and alizarin red-positive mineralization, regardless of H2O2 treatment. Osteoblast-differentiating hPDCs displayed increased ROS production compared with non-differentiating hPDCs, and treatment with tiron reduced ROS production in the differentiating cells. Antioxidants decreased the rates of oxygen consumption and ATP production, which are increased in hPDCs during osteoblastic differentiation. In addition, treatment with tiron reduced the levels of most mitochondrial proteins, which are increased in hPDCs during culture in osteogenic induction medium. These results suggest that tiron exerts negative effects on the osteoblastic differentiation of hPDCs by causing mitochondrial dysfunction. 相似文献
47.
Eun Sil Koh Soojeong Kim Mina Son Ji-Young Park Jaehyuk Pyo Wan-Young Kim Minyoung Kim Sungjin Chung Cheol Whee Park Ho-Shik Kim Seok Joon Shin 《International journal of molecular sciences》2022,23(22)
Renal fibrosis, the final pathway of chronic kidney disease, is caused by genetic and epigenetic mechanisms. Although DNA methylation has drawn attention as a developing mechanism of renal fibrosis, its contribution to renal fibrosis has not been clarified. To address this issue, the effect of zebularine, a DNA methyltransferase inhibitor, on renal inflammation and fibrosis in the murine unilateral ureteral obstruction (UUO) model was analyzed. Zebularine significantly attenuated renal tubulointerstitial fibrosis and inflammation. Zebularine decreased trichrome, α-smooth muscle actin, collagen IV, and transforming growth factor-β1 staining by 56.2%. 21.3%, 30.3%, and 29.9%, respectively, at 3 days, and by 54.6%, 41.9%, 45.9%, and 61.7%, respectively, at 7 days after UUO. Zebularine downregulated mRNA expression levels of matrix metalloproteinase (MMP)-2, MMP-9, fibronectin, and Snail1 by 48.6%. 71.4%, 31.8%, and 42.4%, respectively, at 7 days after UUO. Zebularine also suppressed the activation of nuclear factor-κB (NF-κB) and the expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, by 69.8%, 74.9%, and 69.6%, respectively, in obstructed kidneys. Furthermore, inhibiting DNA methyltransferase buttressed the nuclear expression of nuclear factor (erythroid-derived 2)-like factor 2, which upregulated downstream effectors such as catalase (1.838-fold increase at 7 days, p < 0.01), superoxide dismutase 1 (1.494-fold increase at 7 days, p < 0.05), and NAD(P)H: quinone oxidoreduate-1 (1.376-fold increase at 7 days, p < 0.05) in obstructed kidneys. Collectively, these findings suggest that inhibiting DNA methylation restores the disrupted balance between pro-inflammatory and anti-inflammatory pathways to alleviate renal inflammation and fibrosis. Therefore, these results highlight the possibility of DNA methyltransferases as therapeutic targets for treating renal inflammation and fibrosis. 相似文献
48.
Adam Alemayehu Dominika Zákutná Soňa Kohúteková Václav Tyrpekl 《Journal of the American Ceramic Society》2022,105(7):4621-4631
Ceria, pure or doped, is an important electrolyte material in solid oxide fuel cells, catalysts, and plutonium surrogates. Even though ceria is a widely studied material, its coprecipitation with the most common doping element, gadolinium, remains mostly overlooked. Here, we present a comprehensive study of gadolinium–cerium oxalates prepared by coprecipitation of gadolinium (III) and cerium (III) salts by oxalic acid under different reaction conditions and element ratios. For this purpose, we assessed the effects of basic precipitation conditions on the final oxalate size, shape, and conversion into the corresponding oxides. The results showed that coprecipitation with oxalic acid yields and ideal solid solution, which translates into the oxides. This low-cost and straightforward synthetic route provides then high-quality solid solutions of Ge–Gd in the oxide lattice. Thus, this approach has a high industrialization potential, with significant advantages over hydrolysis or hydrothermal techniques. 相似文献
49.
Nikhil K. Tulsian Valerie Jia-En Sin Hwee-Ling Koh Ganesh S. Anand 《International journal of molecular sciences》2021,22(10)
Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized to actively associate with cyclic nucleotide receptors (protein kinases, PKs) in larger macromolecular assemblies referred to as signalosomes. Complexation of PDEs with PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated PDEs to preferentially catalyze active hydrolysis of cyclic nucleotides bound to PKs and aid in signal termination. PDEs are important drug targets, and current strategies for inhibitor discovery are based entirely on targeting conserved PDE catalytic domains. This often results in inhibitors with cross-reactivity amongst closely related PDEs and attendant unwanted side effects. Here, our approach targeted PDE–PK complexes as they would occur in signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted to identify inhibitors that block cyclic nucleotide pockets in PDE–PK complexes in one mode and disrupt protein-protein interactions between PDEs and PKs in a second mode. We tested this approach with three different systems—cAMP-specific PDE8–PKAR, cGMP-specific PDE5–PKG, and dual-specificity RegA–RD complexes—and ranked inhibitors according to their inhibition potency. Targeting PDE–PK complexes offers biochemical tools for describing the exquisite specificity of cyclic nucleotide signaling networks in cells. 相似文献
50.