Polyethylenimine ethoxylated interlayer-mediated ZnO interfacial engineering for high-performance and low-temperature processed flexible perovskite solar cells: A simple and viable route for one-step processed CH₃NH₃PbI₃

Lim, Ju Won,Wang, Huan,Choi, Chi Hun,Quan, Li Na,Chung, Kyungwha,Park, Won-Tae,Noh, Yong-Young,Kim, Dong Ha Elsevier 2019 Journal of Power Sources Vol.438 No.-

<P><B>Abstract</B></P> <P>Developing perovskite solar cells (PSCs) with high-efficiency and a low-temperature process has great potential for the realization of the scalable, economic, and roll-to-roll based renewable energy conversion devices. ZnO has been recognized as the promising electron transport layer (ETL) that may overcome the limitations of the conventional TiO<SUB>2</SUB>. However, methylammonium lead iodide (MAPbI<SUB>3</SUB>) perovskite is prone to decomposition at the ZnO surface, which hinders the development of simple one-step deposition of perovskite, resulting in the limited photovoltaic performance. Herein, we report interlayer mediated efficient ETLs for viable flexible PSCs. The utilization of polyethyleneimine ethoxylated layer on ZnO prevents the direct contact between the perovskite and ETLs, avoiding the photoactive layer decomposition. Thus, interlayer-mediated PSCs show higher efficiency with enhanced stability by decreasing the electron transport barrier. As a result, the PSC employing tailor-designed ETL interfaces exhibited average power conversion efficiency (PCE) of 15.8%, which was superior by 25.4% to that of a control device (12.6%). With our strategy, we further demonstrated PSCs on flexible substrates which exhibit an average PCE of 11.9% under low-temperature fabrication. The new interface engineering strategy may pave the way to the realization of high performance, easy-to-process, and large-area perovskite optoelectronics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Universal interface engineering technique for highly stable flexible PSCs. </LI> <LI> The in-depth investigation into the enhanced stability and high-efficiency PSCs. </LI> <LI> Interlayer mediated PSC exhibits 15.8% PCE, superior by 25.4% to control device. </LI> <LI> Low-temperature processed PSCs for the next-generation renewable energy sources. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Self-powered reduced-dimensionality perovskite photodiodes with controlled crystalline phase and improved stability

Lim, Ju Won,Wang, Huan,Choi, Chi Hun,Kwon, Hannah,Quan, Li Na,Park, Won-Tae,Noh, Yong-Young,Kim, Dong Ha Elsevier 2019 Nano energy Vol.57 No.-

<P><B>Abstract</B></P> <P>In this work, we developed the perovskite photodiodes based on the dimensionality-reduced quasi two-dimensional (Q-2D) photoactive layer structure by incorporating phenylethylammonium iodide (PEAI) into methylammonium lead iodide (MAPbI<SUB>3</SUB>), which effectively enhanced both the crystalline phase and the ambient stability of the perovskite. The Q-2D perovskite photodiode exhibited a dark current of 1.76 × 10<SUP>−7</SUP> A/cm<SUP>2</SUP>, resulting in the detectivity (D*) of 2.20 × 10<SUP>12</SUP> J and responsivity of 0.53 A/W, which is among the highest performance levels without the voltage bias (0 V) due to the systematically optimized perovskite phase resulting in the reduced leakage current. In addition, the current density of Q-2D perovskite photodiode maintained 76% of the initial level current density even after 80 days in the ambient condition, compared to 15% of 3D perovskite photodiode control sample. Such superior performance and stability were mainly attributed to the enhanced degree of crystallization of the Q-2D perovskites, which was confirmed by X-ray diffraction and grazing incidence wide-angle X-ray scattering (GIWAXS) measurement. Also, the improved stability of Q-2D perovskite films was confirmed by both lifetime test and atomic force microscopy studies where the negligible number of pinholes was observed in the quasi-2D perovskite films while considerable deformations were found in the 3D perovskites photodiode. Our study suggests a simple and robust protocol for the development of stable and high-performance perovskite photodetectors via dimensional and constitutional optimization of conventional perovskites for the practical usage of perovskite in the photodiode applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Q-2D perovskite photodiode exhibited the D* of 2.20 × 10<SUP>12</SUP> J and R of 0.53 A/W without the voltage bias (0 V). </LI> <LI> The current density of Q-2D perovskite photodiode maintained 76 % of the initial level while 15 % for the 3D one. </LI> <LI> Grazing incidence wide-angle X-ray scattering (GIWAXS) analysis revealed the origin of the stability improvement. </LI> <LI> Quasi-2D perovskite materials can be promising candidates for stable, tunable and flexible optoelectronic applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Dimensionality-controlled perovskite photodiodes with improved stability were systematically fabricated while retaining the comparable electrical performance of conventional three-dimensional perovskites. The quasi-2D perovskite photodetector exhibited an improved detectivity of 2.20 × 10<SUP>12</SUP> J performance and maintained 76% of initial level while the performance of three-dimensional perovskite photodetector remained only 15% after 80 days. Our study suggests a facile solution for the poor stability of the three-dimensional perovskite, with a potential for the development of highly-stable perovskite optoelectronics.</P> <P>[DISPLAY OMISSION]</P>

Microwave-assisted Approach for the Rapid Enzymatic Digestion of Rapeseed Meal

Ju-Fang Li,Fang Wei,Lu-Lu Guo,Gang-You Yuan,Feng-Hong Huang,Mu-Lan Jiang,Yuan-Di Zhao,Xu-Yan Dong,Guang-Ming Li,Hong Chen 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

This study demonstrates the use of a new microwave-assisted approach for accelerating the enzymatic digestion of rapeseed meal. The effects of different microwave parameters, such as the time, temperature, and power level, on the degree of hydrolysis (DH) were investigated by using response surface methodology (RSM). The maximum predicted DH value (10.2%) was in good agreement with the value obtained experimentally using an alkaline protease, which was 12.57% under optimal conditions. In only 7 min, the microwave-assisted method achieved a DH value similar to that obtained by the conventional enzymatic digestion method (4 hr). Therefore,this new technique for rapid enzymatic digestion will improve the application of rapeseed meal in the preparation of protein hydrolysates for use in food and feed.

Risk Factors for Surgical Site Infections after Liver Resec-tion (A Multivariate Analysis of 6,132 Patients)

( Li-yang Sun ),( Jiong-jie Yu ),( Ju-dong Li ),( Xin-fei Xu ),( Jia-he Wang ),( Bing Quan ),( Wen-tao Yan ),( Feng Shen ),( Chao Li ),( Lei Liang ),( Tian Yang ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Surgical site infection (SSI) is a common postoperative complication and associated with an increased morbidity, hospital stay, and overall cost. The aim of the present study was to identify risk factors for SSIs after hepatic resection based on a large single-center cohort. Methods: A retrospective study was conducted of 6,132 patients who underwent liver resection without concomitant biliary reconstruction or gastrointestinal procedures between 2014 and 2016 at the largest hepatic center in China. The occurrences of SSI, classified as incisional SSI and organ/space SSI within 30 days after operation were investigated. Patient- and surgical-related risk variables were collected using standardized data collection form. A likelihood ratio forward regression model was used to assess the independent association of risk factors with SSI. Results: SSI developed in 587 patients (9.6%), including superficial/deep incisional SSI in 357 patients (5.8 %), and organ/ space SSI in 304 patients (5.0 %). Multivariate logistic regression analysis showed that obesity, diabetes mellitus, ASA score ≥ 2, liver cirrhosis, re-hepatectomy, hepatoliathiasis, and intraoperative blood transfusion were independent risk factors of overall SSI. However, incisional and organ/space SSI differed from each other with respect to risk factors. Among a variety of risk factors, hepatolithiasis, liver cirrhosis, and intraoperative blood transfusion were consistently associated with both incisional and organ/space SSI. Conclusions: SSI is a common complication after liver resection, and more caution should be taken in patients with hepatolithiasis or liver cirrhosis. Prevention strategies focusing on factors associated with SSI is necessary in order to reduce SSI after liver resection.

Bioconversion of conjugated linoleic acid by Lactobacillus plantarum CGMCC8198 supplemented with Acer truncatum bunge seeds oil

Dong-Ju Chen,Li-Hua Yan,Qian Li,Cai-jiao Zhang,Chuan-Ling Si,Zhong-Yuan Li,Ya-Jian Song,Hao Zhou,Tong-Cun Zhang,Xuegang Luo 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.6

Conjugated linoleic acid (CLA) isomers, c9, t11- CLA and t10, c12-CLA, have been proved to exhibit excellent biomedical properties for potential use in anticancer applications and in reducing obesity. Acer truncatum Bunge (ATB), which is rich in unsaturated fatty acids, including oleic acid, linoleic acid, and nervonic acid, is a new resource for edible oil. In the present study, we developed a new method for producing two CLA isomers from ATB-seed oil by fermentation using Lactobacillus plantarum CGMCC8198 (LP8198), a novel probiotics strain. Polymerase chain reaction results showed that there was a conserved linoleate isomerase (LIase) gene in LP8198, and its transcription could be induced by ATBseed oil. Analyses by gas chromatography–mass spectrometry showed that the concentration of c9, t11-CLA and t10, c12-CLA in ATB-seed oil could be increased by about 9- and 2.25-fold, respectively, after being fermented by LP8198.

Association of Family History with Cancer Recurrence and Survival in Patients with Hepatitis B-Related Hepatocellular Carcinoma (A Propensity Score Matching Analysis)

( Ju-dong Li ),( Xin-fei Xu ),( Jiong-jie Yu ),( Zhen-li Li ),( Hao Xing ),( Han Wu ),( Han Zhang ),( Chao Li ),( Ming-da Wang ),( Meng-chao Wu ),( Wan-yee Lau ),( Tian Yang ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: A family history of liver cancer is regarded as a risk factor for hepatocellular carcinoma (HCC) development. We investigated the association between family history and cancer recurrence and survival in patients with hepatitis B virus (HBV)- related HCC. Methods: Patients who underwent curative resection of HBV-related HCC between 2003 and 2013 from a tertiary hepatobiliary center in China were enrolled in this study. A family history was defined as a self-reported history of primary liver cancer in the first-degree relatives. Propensity score matching (PSM) and multivariable Cox-regression analyses were performed to compare the overall survival (OS) and recurrence-free survival (RFS) between patients with and without a family history of liver cancer. Results: Of 1,112 patients, 183 patients (16.5%) had a family history of liver cancer. A family history was not associated with OS and RFS (P=0.994 and 0.428) in the entire cohort. Using PSM, 179 pairs of patients with and without a family history but with comparable baseline characteristics and operative variables were created. A family history was associated with decreased OS and RFS (P=0.042 and 0.006) in the PSM cohort. On multivariable Cox-regression analyses, a family history was significantly associated with decreased OS (HR: 1.574, 95% CI: 1.171-2.116, P=0.003) and RFS (HR: 1.534, 95% CI: 1.176-2.002, P=0.002) after adjusting for other prognostic factors. Conclusions: A family history of liver cancer was associated with decreased OS and RFS rates after curative resection in patients with HBV-related HCC.

Preoperative Prealbumin Level as an Independent Predictor of Long-Term Prognosis after Curative Liver Resection of Hepatocellular Carcinoma (a Multicenter Study of 1,483 Patients)

( Ju-dong Li ),( Xin-fei Xu ),( Jiong-jie Yu ),( Jia-he Wang ),( Li- Yang Sun ),( Wen-tao Yan ),( Bing Quan ),( Jian-hong Zhong ),( Yi-sheng Huang ),( Ya-hao Zhou ),( Ting-hao Chen ),( Hong Wang ),( W 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Serum prealbumin is more sensitive to profile nutritional status and liver function than albumin, which could hardly be affected by infusion supplement. This study aims: to identify the relationship between preoperative prealbumin level and the long-term prognosis after curative resection of hepatocellular carcinoma (HCC). Methods: Patients undergone HCC curative resection between 2001 and 2014 at six institutions in China were enrolled. By using 170 mg/dl as cut-off value of serum prealbumin level, these patients were divided into the low and normal preoperative prealbumin groups. The overall survival (OS) and recurrence-free survival (RFS) were analyzed and compared. Univariable and multivariable Cox-regression analyses were performed to identify predictive factors of OS and RFS. Results: Among 1,483 patients, 437 (29.5%) had a low prealbumin level within a week before surgery. The 1-, 3-, and 5-year OS and RFS rates of patients in the low prealbumin group were 83.8, 57.0, and 31.1%, and 67.0, 39.8, and19.9%, respectively, which was significantly poorer than those in the normal group (93.0, 75.5, and 42.6%, and 77.0, 56.4, and 28.4%, both P<0.001). Multivariable analyses revealed that preoperative prealbumin level, but not albumin level, was an independent predictor of OS (HR, 1.789; 95% CI: 1.544 -2.072, P<0.001) and RFS (HR, 1.420; 95% CI: 232-1.636, P<0.001). Conclusions: Preoperative prealbumin level is useful for predicting long-term prognosis in patients undergoing liver resection for HCC. Prealbumin may be suitable to displace albumin, yielding to an updated Child-Pugh grade for accessing liver function.

Is Surgical Resection Justified for Hepatocellular Carcinoma with Portal Vein Tumor Thrombus? (A Systematic Review and Meta-Analysis)

( Liang Lei ),( Xin-fei Xu ),( Jiong-jie Yu ),( Ju-dong Li ),( Zhen-li Li ),( Jun Han ),( Han Zhang ),( Hao Xing ),( Han Wu ),( Ming-da Wang ),( Chao Li ),( Zheng Wang ),( Feng Shen ),( Meng-chao Wu ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) is very poor. According to the BCLC treatment recommendations, sorafenib or other palliative treatment (PT) is recommended as the first-line therapy when it happens. In real world, however, a significant number of selected patients with HCC and PVTT suffered from surgical resection (SR). Methods: PubMed, Embase, Medline and Cochrane library were searched for studies comparing SR with PT (including TACE, sorafenib, etc.) for HCC with PVTT, which were published before September 2017. Results: 4,810 patients from 7 studies were enrolled in this meta-analysis, which divided into the SR group (n = 2,344) and the PT group (n = 2476). When compared with the PT group, the pooled hazard ratio (HR) for the 1, 3 and 5-year OS rates of the SR group were 0.56 (95% CI 0.52-0.60, P=0.03), 0.56 (95% CI 0.53-0.59, P<0.001) and 0.55 (95% CI 0.54-0.57, P<0.001). For subgroup analysis, when compared with the mere TACE group, the pooled HR for the 1, 3 and 5-year OS rates of the SR group were 0.54 (95% CI 0.43-0.67, P=0.81), 0.75 (95% CI 0.65-0.87, P=0.25) and 0.76 (95% CI 0.67-0.88, P=0.25). Conclusions: This meta-analysis demonstrated SR had better OS than TACE or other palliative therapy for HCC with PVTT. SR may be suitable as the first-line treatment for selected patients with resectable HCC and removable PVTT.

Identification of Wiener Model with Discontinuous Nonlinearities using Differential Evolution

Dong-Li Zhang,Ying-Gan Tang,Ju-Hai Ma,Xin-Ping Guan 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.3

This paper deals with the identification of Wiener models with discontinuous nonlinearities. The identification of the Wiener model is formulated as an optimization problem. Differential evolution algorithm, a powerful and robust evolutionary algorithm, is used to search the optimal parameter of the Wiener model such that the error between the output of true model and that of the identified model is minimized. The proposed method can identify the parameters of linear dynamic subsystems and static nonlinear function of the Wiener model simultaneously, and overcome the difficulty of un-availability of the intermediated signal. Two application examples verify that the proposed method can accurately estimate the parameters of the Wiener model even in a low SNR environment.

Carbon Deposition Onto Ni-Based Catalysts for Combined Steam/CO₂ Reforming of Methane

Li, Peng,Park, Yoon Hwa,Moon, Dong Ju,Park, Nam Cook,Kim, Young Chul American Scientific Publishers 2016 Journal of nanoscience and nanotechnology Vol.16 No.2

<P>The present study was performed to suppress carbon deposition by Ce and Fe onto Ni-based catalysts in combined steam/CO2 reforming of methane (CSCRM), which is a process for producing synthesis gas (H-2:CO = 2:1) for gas-to-liquids (GTL). The catalytic reaction was evaluated at 900 degrees C and 20 bar with a reactant feed ratio CH4:CO2:H2O:Ar = 1:0.8:1.3:1 and gas hourly space velocity GHSV = 25,000 h(-1). The Ce and Fe modified Ni/gamma-Al2O3 catalyst was characterized by BET surface area analysis, X-ray diffraction (XRD), H-2 temperature-programmed reduction (TPR), H-2 chemisorption, CO2 temperature-programmed desorption (TPD) and SEM. Ce-and Fe-modified Ni/Al2O3 catalysts exhibited remarkable activity and stability during the CSCRM over the course of 50 hours. It suggested that the Ni(12)-Ce(5)-Fe(5)/Al2O3 catalyst shows highly dispersed Ni particles with strong metal-to-support interaction (SMSI) as well as excellent catalytic activity.</P>