Multi-functional transparent electrode for reliable flexible perovskite solar cells

Han, Gill Sang,Lee, Seongha,Duff, Matthew Lawrence,Qin, Fen,Jiang, Minlin,Li, Guangyong,Lee, Jung-Kun Elsevier 2019 Journal of Power Sources Vol.435 No.-

<P><B>Abstract</B></P> <P>Multilayer MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> (DMD) films are found to be transparent conducting electrodes for use in extremely stable and highly bendable flexible perovskite solar cells (PSCs). The optical transparency and electric properties of DMD and its role as a top electrode of PSCs were studied by changing the thickness of the MoO<SUB>x</SUB> layer. Although the MoO<SUB>x</SUB> thickness was shown to have a negligible effect on the sheet resistance of DMD, the transmittance of visible light, selective carrier transport capability, and long-term stability of a device considerably depend on this factor. The sandwich structure of a 20-nm-thick MoO<SUB>x</SUB>, 7-nm-thick Ag, and 20-nm-thick MoO<SUB>x</SUB> exhibits a high transmittance and large photon–electron conversion rate of PSCs. In addition, PSCs using the DMD top electrode maintain 92% of their initial current density after 24 h of continuous operation owing to a UV light cut-off of the top illumination. Moreover, the overall structure of DMD blocks the diffusion of water and oxygen molecules from real environmental conditions. At the same time, the underlying/upper MoO<SUB>x</SUB> layer retards the degradation through a chemical reaction between Ag and the halide ions inside the cells, as well as foreign ions from outside the polluted atmosphere. When DMD is applied to flexible PSCs on Ti foil, the PCE reaches 14.5%, and mechanical integrity of the PSCs is maintained at a bending radius of 4 mm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> multilayer is used as a top electrode of perovskite solar cells. </LI> <LI> The multilayer electrode has multiple functions in real operation environment. </LI> <LI> 92% of the initial current density is maintained after 24 h continuous operation. </LI> <LI> The efficiency of flexible solar cells using MoO<SUB>x</SUB>/Ag/MoO<SUB>x</SUB> reaches 14.5%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

Li-Fen Hu,Jia-Bin Li,Ying Ye,Xu Li 한국미생물학회 2007 The journal of microbiology Vol.45 No.2

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA (Ser→Ile) and codon 64 of parC (Ala64→Cys, Ala64→Asp), which were related to fluroquinolone resistance.

Effects of sodium diacetate or microbial inoculants on aerobic stability of wilted rye silage

Li Yan Fen,Wang li li,Jeong Eun Chan,김학진,Ahmadi Farhad,김종근 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.12

Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air. Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), Lactobacillus plantarum (LP), L. buchneri (LB), or their equal mixture (LP+LB) at 1×106 colony-forming unit/g fresh matter. Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest in vitro DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages. Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage. Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air.Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), <i>Lactobacillus plantarum</i> (LP), <i>L. buchneri</i> (LB), or their equal mixture (LP+LB) at 1×10⁶ colony-forming unit/g fresh matter.Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest <i>in vitro</i> DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages.Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage.

Effects of sodium diacetate and microbial inoculants on fermentation of forage rye

Yan Fen Li,Eun Chan Jeong,Li Li Wang,Hak-Jin Kim,Farhad Ahmadi,Jong Geun Kim 한국축산학회 2023 한국축산학회지 Vol.65 No.1

Rye (Secale cereale L.) is a valuable annual forage crop in Korea but there is limited information about the impact of chemical and biological additives on fermentation characteristics of the crop. This experiment was conducted to investigate fermentation dynamics of wilted forage rye treated with the following six additives; control (no additive), sodium diacetate applied at 3 g/kg wilted forage weight (SDA3), 6 g/kg wilted forage weight (SDA6), inoculations (106 CFU/g wilted forage) of Lactobacillus plantarum (LP), L. buchneri (LB), or LP+LB. The ensiled rye sampled at 1, 2, 3, 5, 10, 20, 30, and 45 days indicated that the acidification occurred fast within five days of storage than the rest of the storage period. The microbial inoculants decline the pH of ensiled forage, more rapidly than the control or SDA treated, which accompanied by the decrease of water-soluble carbohydrates and increase of lactic acid. Compared with the control silage, all treatments suppressed ammonia-nitrogen formation below to 35 g/kg DM throughout the sampling period. Suppression of total microbial counting occurred in SDA6, LP, and LP + LB. The lactic acid production rates were generally higher in microbial inoculation treatments. Acetic acid concentration was lowest in the LP-treated silage and highest in the SDA- and LB-treated silages. The in vitro dry matter (DM) digestibility and total digestible nutrients were the highest in the silage treated with SDA (6 g/kg) at day 45 of ensiling. Based on lower ammonia-nitrogen concentrations and higher feed value, ensiling forage rye treated with SDA at 6 g/kg is promising through enhanced silage quality.

Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

Hu, Li-Fen,Li, Jia-Bin,Ye, Ying,Li, Xu The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.2

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

Electrochemical Immunosensor for Carcinoembryonic Antigen Detection Based on Mo-Mn3O4/MWCNTs/Chits Nanocomposite Modified ITO Electrode

Wen-Ting Li,Yu Wang,Fen-Fang Deng,Li-Li Liu,Hai-Jun Nan,He Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.8

A novel electrochemical immunosensor for determination of carcinoembryonic antigen (CEA) in human serum was fabricated by depositing Mo–Mn3O4/MWCNTs/Chits nanocomposite onto an indium-tin oxide (ITO) electrode. Mo-doped Mn3O4 (MMO) was synthesized by sol–gel method and the presence of molybdenum improved its electrochemical properties. The MMO/ MWCNTs/Chits nanocomposite could accelerate the electron transfer rate and enlarge the surface area to capture a large number of Carcinoembryonic Antigen (CEA). The factors influencing the performance of the immunosensor were investigated, such as incubation time, incubation temperature and pH. Under optimal conditions, the electrochemical immunosensor could detect CEA in a linear range from 0.1 ng · mL-1 to 125 ng · mL-1 with a detection limit of 4.9 pg · mL-1 (S/N = 3). In addition, it exhibited high sensitivity and acceptable stability on a promising immobilization platform for signal amplification, which could be extended to other labeled recognition systems. This electrochemical immunosensor may provide potential applications for the clinical diagnosis.

Evaluating optimum tilt angle for PV modules using solar radiation models in Wuhan, China

Fen. Li,Nianjun. Ma,Jinbin. Zhao,Keqing. Qu,Xingwu. Yang,Zhenghong. Chen 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Four models are used to estimate the hourly solar radiation on 15 pieces of different tilted photovoltaic (PV) modules in Wuhan, China based on power and solar radiation data during a whole year. The optimum tilt angle (OTA) in Wuhan for yearly and semi-yearly adjustment was determined. Then it was determined that the best mode is the tilt angle of PV module adjusted every half a year. In semi-yearly adjustment, OTA in semi-year of winter and summer is found as 45°, 15°, respectively. Experimental results verify the theoretical calculated values of the OTA with high precision. Energy radio (ER) reveals PV modules with adjustment of tilt angle twice a year has a capability to improve nearly 7% in comparison with fixed type. The best model was chosen based on test results from statistical indicators. The statistical results demonstrate that among the studied models, Liu&Jordan model is the most accurate.

THE PERIODIC JACOBI MATRIX PROCRUSTES PROBLEM

Li, Jiao-Fen,Hu, Xi-Yan The Korean Society for Computational and Applied M 2010 Journal of applied mathematics & informatics Vol.28 No.3

The following "Periodic Jacobi Procrustes" problem is studied: find the Periodic Jacobi matrix X which minimizes the Frobenius (or Euclidean) norm of AX - B, with A and B as given rectangular matrices. The class of Procrustes problems has many application in the biological, physical and social sciences just as in the investigation of elastic structures. The different problems are obtained varying the structure of the matrices belonging to the feasible set. Higham has solved the orthogonal, the symmetric and the positive definite cases. Andersson and Elfving have studied the symmetric positive semidefinite case and the (symmetric) elementwise nonnegative case. In this contribution, we extend and develop these research, however, in a relatively simple way. Numerical difficulties are discussed and illustrated by examples.

Molecular characterization and functional analysis of two trehalose transporter genes in the cabbage beetle, Colaphellus bowringi

Li Jia-Xu,Cao Zhen,Guo Shuang,Tian Zhong,Liu Wen,Zhu Fen,Wang Xiao-Ping 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.3

The trehalose, major blood sugar in insects, enhances stress resistance of diapausing individuals in adverse environment and provides an energy source for reproduction. Trehalose transporters (TRETs) play an important role in transport of trehalose from trehalose-producing tissues, e.g. fat body, to trehalose-consuming tissues. Although studies have shown that trehalose contributes to diapause and reproduction, the function of TRETs in these processes remains unclear. In this work, we cloned two TRET genes, TRET1a and TRET1b, from the cabbage beetle Colaphellus bowringi, which is capable of entering reproductive diapause under long-day conditions. We also analyzed the expression profiles of these two genes and investigated their potential roles in diapause and reproduction. The results suggested that both TRET1a and TRET1b belong to sugar-transporter and major facilitator superfamilies. Interestingly, TRET1a was highly expressed in the fat bodies of diapause-destined (DD) females but TRET1b was predominantly expressed in the ovaries of non-diapause-destined (NDD) females. Hormonal induction indicated that juvenile hormone induced TRET1b but repressed TRET1a at transcriptional levels. Methoprene-tolerant and Krüppel homolog 1 mediated the JH-suppressed TRET1a expression but were not involved in the regulation of TRET1b expression by JH. RNAi of TRET1a in DD females elevated the trehalose content in the fat bodies and suppressed the expression of a couple of genes related to stress resistance, which is a critical diapause trait. Knockdown of TRET1b in NDD females reduced the trehalose content in the ovaries but had no apparent effect on the ovary development and yolk deposition. These data suggest that TRET1a and TRET1b could regulate the trehalose content in specific tissues and may play potential roles in reproductive diapause in the females of C. bowringi. Introduction Diapause is a survival strategy for many insects in adapting to adverse environmental conditions (Tauber and Tauber, 1976; Tougeron, 2019). Diapause is a dynamic successive process that consists of diapause induction, preparation, initiation, maintenance, termination, and post-diapause quiescence (Kostal, 2006). Insects accumulate enormous nutrients such as sugars and lipids to enter diapause during diapause preparation phase (Hahn and Denlinger, 2007, 2011). The trehalose is the major hemolymph sugar in insects. The sugar not only provides source of energy but also protects proteins and cellular membranes from dehydration, desiccation, heat, cold, and oxidation (Elbein et al., 2003; Li et al., 2002; Richards et al., 2002; Wyatt and Kalf, 1957; Yancey, 2005; Zhu et al., 2008). Therefore, trehalose can play roles in reproduction and diapause by mediating energy supply and stress tolerance, respectively (Kamei et al., 2011; Lu et al., 2019; Xu et al., 2009).

Characterization and function of a short peptidoglycan recognition protein from the Chinese oak silkworm, Antheraea pernyi

Li-Shang Dai,Cen Qian, LeiWang,Guo-Qing Wei,Qiu-Ning Liu,Yu Sun,Cong-Fen Zhang,Jun Li,Dong-Ran Liu,Bao-Jian Zhu,Chao-Liang Liu 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.4

Peptidoglycan recognition proteins (PGRPs) are conserved proteins in animals from insects to mammals and play an important role in immune response by recognizing peptidoglycan on microbial surfaces. In this study, a PGRP gene from Antheraea pernyi, named Ap-PGRP-A, was isolated and characterized. Sequence analysis revealed that the full-length cDNA of Ap-PGRP-A was 961 bp, containing a 40 bp 5′-untranslated sequence, a 339 bp 3′-untranslated region and an open reading frame of 582 bp. This gene encoded a putative protein of 193 amino acid residues. Phylogenetic analysis indicated that Ap-PGRP-A had the closest protein sequence similarity to Antheraea mylitta PGRP. The recombinant protein was successfully expressed in Escherichia coli cells and a rabbit anti-Ap-PGRP-A antibody was also prepared. Real-time quantitative reverse transcription-PCR analysis showed that Ap-PGRP-A was extensively expressed in the fat body, midgut, hemocyte,malpighian tubule and epidermis of A. pernyi, especially in the fat body and midgut. The expression levels of Ap-PGRP-A were significantly up-regulated by three types of microorganisms, and Ap-PGRP-A expression was more sensitive in response to the Gram-negative bacterium E. coli than the Gram-positive bacterium Bacillus subtilis or the fungus Beauveria bassiana. These data indicate that Ap-PGRP-A may play a role in the innate immune responses of A. pernyi.