High-performance broadband heterojunction photodetectors based on multilayered PtSe₂ directly grown on a Si substrate

Xie, Chao,Zeng, Longhui,Zhang, Zhixiang,Tsang, Yuen-Hong,Luo, Linbao,Lee, Jung-Ho The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.32

<P>Two-dimensional group-10 transition metal dichalcogenides have recently attracted increasing research interest because of their unique electronic and optoelectronic properties. Herein, we present vertical hybrid heterojunctions of multilayered PtSe2 and Si, which take advantage of large-scale homogeneous PtSe2 films grown directly on Si substrates. These heterojunctions show obvious rectifying behavior and a pronounced photovoltaic effect, enabling them to function as self-driven photodetectors operating at zero bias. The photodetectors can operate in both photovoltage and photocurrent modes, with responsivity values as high as 5.26 × 10<SUP>6</SUP> V W<SUP>−1</SUP> and 520 mA W<SUP>−1</SUP> at 808 nm, respectively. The <I>I</I>light/<I>I</I>dark ratio, specific detectivity, and response speed are 1.5 × 10<SUP>5</SUP>, 3.26 × 10<SUP>13</SUP> Jones, and 55.3/170.5 μs, respectively. Furthermore, the heterojunctions are highly sensitive in a broad spectral region ranging from deep ultraviolet to near-infrared (NIR) (200-1550 nm). Because of the strong NIR light absorption of PtSe2, the heterojunctions exhibit photocurrent responsivities of 33.25 and 0.57 mA W<SUP>−1</SUP> at telecommunication wavelengths of 1310 and 1550 nm, respectively. Considering the excellent performance of the PtSe2/Si heterojunctions, they are highly suitable for application in high-performance broadband photodetectors. The generality of the above results also signifies that the proposed <I>in situ</I> synthesis method has great potential for future large-scale optoelectronic device integration.</P>

Scaffold Engineering with Flavone-Modified Biomimetic Architecture for Vascular Tissue Engineering Applications

Xie Chao,Guo Ting,Wang Wei,Li Gang,Cai Zhou,Chen Shen,Wang Xianwei,Liu Ziyu,Wang Zuyong 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Vascular intimal hyperplasia (IH) is one of the key challenges in the clinical application of smalldiameter vascular grafts. Current tissue engineering strategies focus on vascularization and antithrombotics, yet few approaches have been developed to treat IH. Here, we designed a tissue-engineered vascular scaffold with portulaca flavonoid (PTF) composition and biomimetic architecture. METHOD: By electrospinning, PTF is integrated with biodegradable poly(e-caprolactone) (PCL) into a bionic vascular scaffold. The structure and functions of the scaffolds were evaluated based on material characterization and cellular biocompatibility. Human vascular smooth muscle cells (HVSMCs) were cultured on scaffolds for up to 14 days. RESULTS: The incorporation of PTF and preparation parameters during fabrication influences the morphology of the scaffold, including fibre diameter, structure, and orientation. Compared to the PCL scaffold, the scaffolds integrated with bioactive PTF show better hydrophilicity and degradability. HVSMCs seeded on the scaffold alongside the fibres exhibit fusiform-like shapes, indicating that the scaffold can provide contact guidance for cell morphology alterations. This study demonstrates that the PCL/PTF (9.1%) scaffold inhibits the excessive proliferation of HVSMCs without causing cytotoxicity. CONCLUSION: The study provides insights into the problem of restenosis caused by IH. This engineered vascular scaffold with complex function and preparation is expected to be applied as a substitute for small-diameter vascular grafts.

Numerical investigation on aerodynamic performance of a 2-D inclined hovering wing in asymmetric strokes

Chao Wang,Chaoying Zhou,Peng Xie 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

A numerical study on the effects of the asymmetry in flapping motions on the aerodynamic performance of a 2-D inclined hoveringwing is carried out through the solution of the two-dimensional unsteady Navier-Stokes equations. Asymmetric flapping motions withdifferent flapping durations as well as different angles of attack during downstroke and upstroke are considered, correspondingly theaerodynamic forces, the energy consumption and the flow structures of the wing are examined for the purpose. The results show that theasymmetry either in flapping duration or in angle of attack can effectively alter the aerodynamic characteristics of the wing. It is foundthat much larger vertical force is generated in the downstroke with smaller duration. As for the angle of attack, an increase in the angleduring the downstroke gives rise to a larger vertical force and lifting efficiency while for the upstroke the increase in the angle results in alarger thrust force. Furthermore, a combined model with asymmetry in both flapping duration and angles of attack is also studied and theresults show that a combined flapping motion with a faster downstroke and a higher downstroke angle of attack can produce much largervertical force than a motion with asymmetry simply in stroke duration or angle of attack. The present results provide physical insight intoa better understanding of the asymmetric stroke mechanisms in the flapping motion of insects.

Selection of Reference Genes for Real-time Quantitative PCR Normalization in the Process of Gaeumannomyces graminis var. tritici Infecting Wheat

Xie, Li-hua,Quan, Xin,Zhang, Jie,Yang, Yan-yan,Sun, Run-hong,Xia, Ming-cong,Xue, Bao-guo,Wu, Chao,Han, Xiao-yun,Xue, Ya-nan,Yang, Li-rong The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.1

Gaeumannomyces graminis var. tritici is a soil borne pathogenic fungus associated with wheat roots. The accurate quantification of gene expression during the process of infection might be helpful to understand the pathogenic molecular mechanism. However, this method requires suitable reference genes for transcript normalization. In this study, nine candidate reference genes were chosen, and the specificity of the primers were investigated by melting curves of PCR products. The expression stability of these nine candidates was determined with three programs-geNorm, Norm Finder, and Best Keeper. $TUB{\beta}$ was identified as the most stable reference gene. Furthermore, the exopolygalacturonase gene (ExoPG) was selected to verify the reliability of $TUB{\beta}$ expression. The expression profile of ExoPG assessed using $TUB{\beta}$ agreed with the results of digital gene expression analysis by RNA-Seq. This study is the first systematic exploration of the optimal reference genes in the infection process of Gaeumannomyces graminis var. tritici.

Numerical investigation into the effects of stroke trajectory on the aerodynamic performance of insect hovering flight

Chao Wang,Chaoying Zhou,Peng Xie 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Various stroke trajectories may be observed in insect hovering flight in nature; however their influences on the flight performance of insect are not well estimated. In this study, a numerical investigation into the effects of stroke trajectories on the aerodynamic performance of insect hovering flight is carried out through the solution of the two-dimensional unsteady incompressible Navier-Stokes equations. An insect wing model with ellipse cross section in hovering flight is considered for the purpose and four types of idealized trajectories (Named linear, oval, figure-eight and double-eight) which possess different deviation characteristics from the stroke plane are examined. The influences of the deviation amplitude of trajectory, the attack angle of wing and the inclined angle of stroke plane on the aerodynamic characteristics of hovering wing are systematically analyzed. The results show that in the case of the wing in a normal hovering flight where the stroke plane is horizontal, the trajectory deviation from the stroke plane weakens the aerodynamic performance for each trajectory case considered, and this deteriorative effect becomes more serious as the amplitude of deviation increases. With regard to the influence of the angle of attack, the results show that the time-averaged drag force and power consumption increase monotonically with the angle, whereas the time-averaged lift force and the lifting efficiency increase first and then decrease as the angle increases further. In the case of a hovering flight with an inclined stroke plane, distinctly different trends from a normal hovering flight are obtained.

Saliva Supernatant miR-21: a Novel Potential Biomarker for Esophageal Cancer Detection

Xie, Zi-Jun,Chen, Gang,Zhang, Xu-Chao,Li, Dong-Feng,Huang, Jian,Li, Zi-Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Objective: To identify whether saliva supernatant miR-21 can serve as a novel potential biomarker in patients with esophageal cancer (EC). Methods: 32 patients with EC and 16 healthy controls were recruited in this study. Total RNA was extracted from saliva supernatant samples for measurement of miR-21 levels using RT-qPCR and relationships between miR-21 levels and clinical characteristics of EC patients were analyzed. Results: miR-21 was significantly higher in the EC than control groups. The sensitivity and specificity were 84.4% and 62.5% respectively. Supernatant miR-21 levels showed no significant correlation with cancer stage, differentiation and nodal metastasis. Conclusions: Saliva supernatant miR-21 may be a novel biomarker for EC.

Nitrogen metabolism and mammary gland amino acid utilization in lactating dairy cows with different residual feed intake

Xie, Yunyi,Miao, Chao,Lu, Yi,Sun, Huizeng,Liu, Jianxin Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.10

Objective: This study was conducted to enhance our understanding of nitrogen (N) metabolism and mammary amino acid (AA) utilization in lactating cows with divergent phenotypes of residual feed intake (RFI). Methods: Fifty-three multiparous mid-lactation Holstein dairy cows were selected for RFI measurements over a 50-d experimental period. The 26 cows with the most extreme RFI values were classified into the high RFI (n = 13) and low RFI (n = 13) groups, respectively, for analysis of N metabolism and AA utilization. Results: Compared with the high RFI cows, the low RFI animals had lower dry matter intake (p<0.01) with no difference observed in milk yield between the two groups (p>0.10). However, higher ratios of milk yield to dry matter intake (p<0.01) were found in the low RFI cows than in the high RFI cows. The low RFI cows had significant greater ratios of milk protein to metabolizable protein (p = 0.02) and milk protein to crude protein intake than the high RFI cows (p = 0.01). The arterial concentration and mammary uptake of essential AA (p<0.10), branched-chain AA (p<0.10), and total AA (p<0.10) tended to be lower in the low RFI cows. Additionally, the low RFI cows tended to have a lower ratio of AA uptake to milk output for essential AA (p = 0.08), branched-chain AA (p = 0.07) and total AA (p = 0.09) than the high RFI cows. Conclusion: In summary, both utilization of metabolizable protein for milk protein and mammary AA utilization are more efficient in cows with lower RFI than in the high RFI cows. Our results provide new insight into the protein metabolic processes (related to N and AA) involved in feed efficiency.

Resource recovery and harmless treatment of waste oil-in-water drilling fluid

Chao Tang,Shui Xiang Xie 대한환경공학회 2017 Environmental Engineering Research Vol.22 No.3

Destablization and demulsification is a difficult task for the treatment of waste oil-in-water drilling fluid because of its “three-high” characteristics: emulsification, stabilization and oiliness. At present, China is short for effective treating technology, which restricts cleaner production in oilfield. This paper focused on technical difficulties of waste oil-in-water drilling fluid treatment in JiDong oilfield of China, adopting physical-chemical collaboration demulsification technology to deal with waste oil-in-water drilling fluid. After oil-water-solid three-phase separation, the oil recovery rate is up to 90% and the recycled oil can be reused for preparation of new drilling fluid. Meanwhile, harmless treatment of wastewater and sludge from waste oil-in-water drilling fluid after oil recycling was studied. The results showed that wastewater after treated was clean, contents of chemical oxygen demand and oil decreased from 993 mg/L and 21,800 mg/L to 89 mg/L and 3.6 mg/L respectively, which can meet the requirements of grade one of “The National Integrated Wastewater Discharge Standard” (GB8978); The pollutants in the sludge after harmless treatment are decreased below the national standard, which achieved the goal of resource recovery and harmless treatment on waste oil-in-water drilling fluid.

Comparative Study of Two Common In Vitro Models for the Pancreatic Islet with MIN6

Chao Xinxin,Zhao Furong,Hu Jiawei,Yu Yanrong,Xie Renjian,Zhong Jianing,Huang Miao,Zeng Tai,Yang Hui,Luo Dan,Peng Weijie 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.1

BACKGROUND: Islet transplantation is currently considered the most promising method for treating insulin-dependent diabetes. The two most-studied artificial islets are alginate-encapsulated b cells or b cell spheroids. As three-dimensional (3D) models, both artificial islets have better insulin secretory functions and transplantation efficiencies than cells in twodimensional (2D) monolayer culture. However, the effects of these two methods have not been compared yet. Therefore, in this study, cells from the mouse islet b cell line Min6 were constructed as scaffold-free spheroids or alginate-encapsulated dispersed cells. METHODS: MIN6 cell spheroids were prepared by using Agarose-base microwell arrays. The insulin secretion level was determined by mouse insulin ELISA kit, and the gene and protein expression status of the MIN6 were performed by Quantitative polymerase chain reaction and immunoblot, respectively. RESULTS: Both 3D cultures effectively promoted the proliferation and glucose-stimulated insulin release (GSIS) of MIN6 cells compared to 2D adherent cells. Furthermore, 1% alginate-encapsulated MIN6 cells demonstrated more significant effects than the spheroids. In general, three pancreatic genes were expressed at higher levels in response to the 3D culture than to the 2D culture, and pancreatic/duodenal homeobox-1 (PDX1) expression was higher in the cells encapsulated in 1% alginate than that in the spheroids. A western blot analysis showed that 1% alginate-encapsulated MIN6 cells activated the phosphoinositide 3-kinase (PI3K)/serine/threonine protein kinase (AKT)/forkhead transcription factor FKHR (FoxO1) pathway more than the spheroids, 0.5% alginate-, or 2% alginate-encapsulated cells did. The 3D MIN6 culture, therefore, showed improved effects compared to the 2D culture, and the 1% alginate-encapsulated MIN6 cells exhibited better effects than the spheroids. The upregulation of PDX1 expression through the activation of the PI3K/AKT/FoxO1 pathway may mediate the improved cell proliferation and GSIS in 1% alginate-encapsulated MIN6 cells. CONCLUSION: This study may contribute to the construction of in vitro culture systems for pancreatic islets to meet clinical requirements.

Metabolic Regulation of Gene Expression by Histone Lysine β-Hydroxybutyrylation

Xie, Zhongyu,Zhang, Di,Chung, Dongjun,Tang, Zhanyun,Huang, He,Dai, Lunzhi,Qi, Shankang,Li, Jingya,Colak, Gozde,Chen, Yue,Xia, Chunmei,Peng, Chao,Ruan, Haibin,Kirkey, Matt,Wang, Danli,Jensen, Lindy M. Elsevier 2016 Molecular cell Vol.62 No.2

<P><B>Summary</B></P> <P>Here we report the identification and verification of a β-hydroxybutyrate-derived protein modification, lysine β-hydroxybutyrylation (Kbhb), as a new type of histone mark. Histone Kbhb marks are dramatically induced in response to elevated β-hydroxybutyrate levels in cultured cells and in livers from mice subjected to prolonged fasting or streptozotocin-induced diabetic ketoacidosis. In total, we identified 44 histone Kbhb sites, a figure comparable to the known number of histone acetylation sites. By ChIP-seq and RNA-seq analysis, we demonstrate that histone Kbhb is a mark enriched in active gene promoters and that the increased H3K9bhb levels that occur during starvation are associated with genes upregulated in starvation-responsive metabolic pathways. Histone β-hydroxybutyrylation thus represents a new epigenetic regulatory mark that couples metabolism to gene expression, offering a new avenue to study chromatin regulation and diverse functions of β-hydroxybutyrate in the context of important human pathophysiological states, including diabetes, epilepsy, and neoplasia.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lysine β-hydroxybutyrylation (Kbhb) is a new type of histone mark </LI> <LI> 44 non-redundant histone Kbhb sites are identified in human and mouse cells </LI> <LI> Histone Kbhb increases under starvation and STZ-induced ketoacidosis </LI> <LI> Starvation-induced H3K9bhb is associated with active gene expression </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>