Crystal growth of small-molecule organic semiconductors with nucleation additive

He Zhengran,Zhang Ziyang,Asare-Yeboah Kyeiwaa,Bi Sheng,Chen Jihua,Li Dawen 한국물리학회 2021 Current Applied Physics Vol.21 No.-

In this study, we employ a nucleation additive 4-octylbenzoic acid (OBA) with an optimized solvent evaporation method to regulate crystal orientation and grain width of small-molecule organic semiconductors. When 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS pentacene) was utilized as a benchmark material to mix with the additive, a self-assembled OBA interfacial layer was formed and promoted uniform deposition of nucleation seeds. As a result, the TIPS pentacene/OBA blend crystalline film exhibited crystal alignment in long range order, attributing to a 11-fold reduction of the crystal misorientation angle and a 4-fold increase of the grain width. We further discussed the important correlation between the effective hole mobility, grain boundaries, grain width and length, and nucleation sites. Organic thin film transistors were fabricated to test charge transport, yielding a hole mobility of up to 0.17 cm2/V. This work provides a new pathway to modulate the nucleation and crystallization events of organic semiconductors, and can potentially be applied to optimize the thin film morphology and electrical performance of organic semiconducting materials in general.

Effects of Emodin Extracted from Chinese Herbs on Proliferation of Non-small Cell Lung Cancer and Underlying Mechanisms

He, Lin,Bi, Juan-Juan,Guo, Qian,Yu, Yin,Ye, Xiu-Feng Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

To aim of this was to observe emodin-mediated cytotoxicity and its influence on Rad51 and ERCC1 expressionin non-small cell lung cancer (NSCLC). NSCLC cells were cultured in vitro with emodin at various concentrations (0, 25, 50, 75 and $100\;{\mu}mol/L$) for 48h and the proliferation inhibition rate was determined by the MTT method. Then, NSCLC were treated with emodin (SK-MES-1 $40\;{\mu}mol/L$, A549 $70\;{\mu}mol/L$) or $20\;{\mu}mol/L$ U0126 (an ERK inhibitor) for 48 h, or with various concentrations of emodin for 48 h and the protein and mRNA expressions of ERCC1 and Rad51 were determined by RT-PCR and Western blot assay, respectively. Emodin exerted a suppressive effect on the proliferation of NSCLC in a concentration dependent manner. Protein and mRNA expression of ERCC1 and Rad51 was also significantly decreased with the dose. Vacuolar degeneration was observed in A549 and SK-MES-1 cell lines after emodin treatment by transmission electron microscopy. Emodin may thus inhibited cell proliferation in NSCLC cells by downregulation ERCC1 and Rad51.

High Glucose Causes Human Cardiac Progenitor Cell Dysfunction by Promoting Mitochondrial Fission: Role of a GLUT1 Blocker

( He Yun Choi ),( Ji Hye Park ),( Woong Bi Jang ),( Seung Taek Ji ),( Seok Yun Jung ),( Da Yeon Kim ),( Songhwa Kang ),( Yeon Ju Kim ),( Jisoo Yun ),( Jae Ho Kim ),( Sang Hong Baek ),( Sang Mo Kwon ) 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

TWO APPLICATIONS OF LEWIS' THEOREM ON CHARACTER DEGREE GRAPHS OF SOLVABLE GROUPS

He, Liguo,Zhao, Yuanhe,Bi, Jianxing Korean Mathematical Society 2015 대한수학회보 Vol.52 No.2

In this note, we prove Gluck's conjecture and Isaacs-Navarro-Wolf Conjecture are true for the solvable groups with disconnected graphs by using Lewis' group structure theorem with respect to the disconnected character degree graphs.

Effect of Polymer Molecular Weight on Morphology and Charge Transport of Small‑Molecular Organic Semiconductors

Zhengran He,Ziyang Zhang,Sheng Bi,Jihua Chen 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

The utilization of polymer additives provides an intriguing pathway to tune the electrical performance of solution-grown,small-molecular organic semiconductors. In this study, we report the effect of different polymer molecular weight on thecrystal growth, phase segregation and charge transport of the organic semiconductors. A semicrystalline polymer additivepolyethylene oxide (PEO) with 8000 and 100 K molecular weight was blended with a well-known organic semiconductor6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene). Distinctively different thin film morphology of the resultantTIPS pentacene/PEO blend film was identified and quantitatively characterized. In particular, PEO with a higher molecularweight of 100 K exerted a stronger effect on enhancing film formation, crystal coverage and likely mechanical properties,whereas PEO with an 8000 molecular weight yielded more superior crystal alignment and larger crystal sizes. Bottom-gate,top-contact TIPS pentacene/PEO OTFTs were fabricated to test the charge transport, which indicated loading the PEOpolymer with molecular weight of 8000 demonstrated a five-fold enhancement in the extracted hole mobilities as comparedto the 100 K counterpart. This work of using polymer additives with different molecular weight can be used to tune thecrystallization of other solution-processed high-mobility small-molecular organic semiconductors.

TWO APPLICATIONS OF LEWIS’ THEOREM ON CHARACTER DEGREE GRAPHS OF SOLVABLE GROUPS

Liguo He,Yuanhe Zhao,Jianxing Bi 대한수학회 2015 대한수학회보 Vol.52 No.2

In this note, we prove Gluck’s conjecture and Isaacs-Navarro- Wolf Conjecture are true for the solvable groups with disconnected graphs by using Lewis’ group structure theorem with respect to the disconnected character degree graphs.

High Glucose Causes Human Cardiac Progenitor Cell Dysfunction by Promoting Mitochondrial Fission: Role of a GLUT1 Blocker

Choi, He Yun,Park, Ji Hye,Jang, Woong Bi,Ji, Seung Taek,Jung, Seok Yun,Kim, Da Yeon,Kang, Songhwa,Kim, Yeon Ju,Yun, Jisoo,Kim, Jae Ho,Baek, Sang Hong,Kwon, Sang-Mo The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.4

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

Solvent Exchange in Controlling Semiconductor Morphology

Zhengran He,Ziyang Zhang,Kyeiwaa Asare-Yeboah,Sheng Bi 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.6

Recent studies in solution processed, small molecular organic semiconductors have reported unparalleled advances in charge carrier mobilities, warranting promising application in organic electronic devices such as organic gas sensors and complimentary circuits. However, the in-solution crystallization of small molecular organic semiconductors has presented specific challenges including crystal misorientation, grain boundary and mobility variation. In this article, we first discuss the effects of these issues on charge transport and highlight the virtues of solvent choices to optimize the semiconductor morphology. Then, we conduct an in-depth review of the miscellaneous solvent exchange methods to effectively palliate these challenges. By discussing various benchmark semiconductor materials such as 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) and perylenetetracarboxyldiimide derivatives (PTCDI-Cn), we demonstrate the solvent exchange-based crystallization methods can modulate supramolecular aggregation, promote nucleation formation, improve semiconductor alignment, change crystal dimensionality, and enhance charge transport. We believe this work provides useful comprehension of employing the solvent exchange methods to powerfully regulate the crystallization, morphology and mobility of organic semiconductors, and thereby casts light on high performance organic electronic applications.

Optimal Configuration of Flexible Interconnection Devices for Transferring Photovoltaic Power in Active Distribution Network

Wu Hongbin,He Ye,Lin Xueshan,Bi Rui,Hua Yuting,Sun Ming,Xu Bin 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

With the increasing penetration of distributed photovoltaic in distribution network, it is more difficult to control active distribution network (ADN). A flexible interconnection device (FID) can realize regional interconnection of the ADN through transferring power. However, the influence of installation position and number of FIDs on the ADN varies, it is necessary to analyze its operational planning model. In this study, first, a photovoltaic power and load forecasting model is established, followed by reduction of the typical scenarios. Second, the ADN operational planning model is established according to the line load balance index to analyze the coordination and determine the power transfer value of the FID in different installation positions and numbers for the ADN. Third, the net income index of the distribution network in the entire life cycle is established to analyze the economy of the ADN and determine the optimal FID installation location and quantity. Finally, numerous simulations and comparisons are carried out on the actual example system, and the results show that the FID can effectively transfer the active power, strengthen the ADN power supply level, and solve the problem of power supply imbalance caused by distributed photovoltaic access.

Tumour volume doubling time of molecular breast cancer subtypes assessed by serial breast ultrasound.

Ryu, Eun Bi,Chang, Jung Min,Seo, Mirinae,Kim, Sun Ah,Lim, Ji He,Moon, Woo Kyung Springer International 2014 EUROPEAN RADIOLOGY Vol.24 No.9

<P>The aim of our study was to evaluate the tumour volume doubling time (TVDT) of molecular breast cancer subtypes by serial ultrasound (US).</P>