bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristic of Methyl-Ammonium Lead Bromide Perovskites Solar Cells Fabricated By One-Step Spin Coating Process for the Application of Transparent Photovoltaics
Authors: Kim Mijoung , Kim Moonhoe , Kim Gisung , Shin Jaekwon , Oh Juyoung , Park Geon , Yang JungYup
Published: December 2020

Perovskite solar cells (PSCs) based on organic-inorganic halide have experienced an unprecedentedly rapid development when the first efficient perovskite-based solar device with solid-state structure was reported in 2009. Also, solution-processed organic-inorganic halide perovskites are currently established as the hottest area of interest in the world of photovoltaics, ensuring low manufacturing cost and relatively simple process and high conversion efficiencies. Methylammonium lead bromide (MAPbBr3) is one of the researched halide perovskite materials for transparent photovoltaics and high open circuit voltage (Voc) solar cells. Here, we have investigated MAPbBr3 absorber layer to increase the Voc and average visible transmittance. The MAPbBr3 perovskite films were fabricated by one-step spin coating process. The properties of MAPbBr3 perovskite films were found to be strongly influenced by the time to spray of anti-solvent solution (chlorobenzen). The result that the MAPbBr3 layer appropriately sprayed with chlorobenzen is beneficial to film quality and device efficiency because the nucleation of MAPbBr3 layer was affected by the anti-solvent engineering, which affected the film crystallite, density, and surface morphology. The MAPbBr3 layer by optimized 7~8 second (time to spray after spinning) showed the best efficiency of above 6.5 % with reproducibility.

This research was also supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2019R1A2C4070248).
(Invited) Silica Based Ionogels: Raman Study of Protic Vs. non Protic Ionic Liquids, with Lithium Salt Vs. Sodium Salt
Authors: Marie Angélique , Bayle Maxime , Galarneau Anne , Said Bilel , Balducci Andrea , Stettner Timo , Ewels Chris , Humbert Bernard , Le Bideau Jean
Published: December 2020

Ionogels represent a route to biphasic materials, for the use of ionic liquids (ILs) for all solid devices. Confining ILs within host networks enhances their averaged dynamics, resulting in improved charge transport. Fragility, short relaxation times, low viscosity, and good ionic conductivity, all them appear to be related to the IL / host network interface. The presence of ILs at interface neighborhood leads to the lowering of cation-anion interaction, i.e. to the breakdown of aggregated and structured regions that are systematically found in bulk ILs.[1] This “destructuration”, as well as segregative interactions at interface,[2] coupled with percolation of the bicontinuous solid/liquid interface,[3] make these materials very competitive among the existing solid electrolytes.

Herein we will present an in-depth study of coordination of TFSI anion with lithium or with sodium cations, in the presence of protic or non protic pyrrolidinium cations, confined within silica with well-controlled porosities. The coordination number of TFSI-cation is shown to decrease upon confinement, making the lithium of sodium cation more diffusive. Moreover, the cation-anion layering at the interface is studied by DFT and shows striking modifications when a lithium or sodium salt is added, thus highlighting the effect of the chemistry of the host network, similarly with previous study.[4]

References

1) A. Guyomard-Lack, P.-E. Delannoy, N. Dupré, C. V. Cerclier, B. Humbert, J. Le Bideau, Phys. Chem. Chem. Phys., 16, (2014) 23639-23645

2) A. Guyomard-Lack, B. Said, N. Dupré, A. Galarneau, J. Le Bideau, New J. Chem., 40, (2016) 4269-4276

3) C. V. Cerclier, J.-M. Zanotti, J. Le Bideau, Phys. Chem. Chem. Phys., 17, (2015) 29707—29713

4) D. Aidoud, D. Guy-Buissou, D. Guyomard, B. Lestriez, J. Le Bideau, J. Electrochem. Soc., 165, (2018) A3179-A3185
(Invited) Enabling Fast Charging Li-ion Batteries through Three-dimensional Graphite Anode Design
Authors: Chen Kuan-Hung , Namkoong Min Ji , Goel Vishwas , Yang Chenglin , Mazumder Jyoti , Thornton Katsuyo , Sakamoto Jeff , Dasgupta Neil P.
Published: December 2020

Current Li-ion battery technology is highly optimized for performance at relatively slow charging rates. However, significant challenges still present for fast-charge conditions with < 15-minute charge time.1 In state-of-the-art Li-ion batteries with high energy densities, thick electrodes (> 50 μm) are adopted, which leads to a tradeoff between energy density and high-power performance. Thicker electrodes with tortuous pathways limit Li-ion transport through the electrode thickness, resulting in large electrolyte concentration gradients during cycling. This causes large cell polarizations, which reduce the accessible capacity of the battery. In addition, the electrochemical potential of the graphite anode can become more negative than the thermodynamic potential of Li metal during fast charging, resulting in irreversible Li plating. Therefore, to simultaneously achieve fast charging and maintain energy density of Li-ion batteries, new approaches are required to address Li ionic transport limitations through the thick graphite anodes.

In this work, we demonstrate a structural modification of conventional graphite anodes to improve their fast-charge capability. This is achieved by introducing laser-patterned vertical channels into post-calendered graphite anodes.2 This 3-D electrode architecture consists of a hexagonal close-packed array of vertical channels that serve as linear pathways for rapid ionic diffusion through the electrode thickness, allowing for a more homogeneous Li-ion flux throughout the volume of the electrode and decreased ionic concentration gradients. As a result, the accessible capacity of the electrode can be significantly improved and Li plating can be minimized during fast charging. Utilizing the 3-D electrode design, we demonstrate significant improvement in capacity fade at 4C (15-minute) and 6C (10-minute) charge rate with industrial-relevant electrode material and loading (> 3 mAh/cm2 electrode loading in > 2Ah pouch cells). This work thus demonstrates the viability of realizing high energy density Li-ion batteries with fast charge capability based on thick electrodes.

Reference

Ahmed, S. et al. Enabling fast charging e A battery technology gap assessment. 367, 250–262 (2017).

Chen, K.-H; Namkoong, M.; Goel, V.; Yang, C.; Mazumder, J; Thornton, K.; Sakamoto, J; Dasgupta, N. P. Efficient Fast-Charging of Lithium-ion Batteries Enabled by Laser-Patterned Three-Dimensional Graphite Anode Architectures. J. Power Sources In Press (2020).
Role of Reduced Graphene Oxide Binder for Supercapacitor with Commercial-Level Mass Loading
Authors: Choi Ji-Hyuk , Kim Byung-su
Published: December 2020

Effective specific-surface-area (SSA) utilization of active materials and rapid ion/electron transport within electrodes with commercial-level mass loadings (>10 mg cm−2) are critical for the practical applications of supercapacitors (SCs). In this study, we demonstrate a versatile method to achieve high-performance SCs for commercial applications using biomass-derived porous activated carbons (PACs) as the main active material and reduced graphene oxide (rGO) as a multifunctional conductive binder that holds the PACs in an interconnected-network structure across the entire electrode. In the resultant PAC–rGO, the rGO sheets not only effectively maintain the high SSA of the PACs to provide abundant active sites in contact with electrolyte ions but also provide conductive passages through which ions can easily pass to reach the PAC surfaces. Functional groups on the rGO binder also promote substantial ion-adsorption capability by improving electrolyte wettability. Benefiting from the multifunctional roles of the rGO binder, the obtained electrode exhibits outstanding specific and areal capacitances as well as excellent rate capability and cycling performance, even with a high mass loading of 12 mg cm−2, demonstrating its strong potential for use in high-performance SCs.
Adhesive Polymer Containing Two-Dimensional Conductive Material As Binder for Electrochemical Double-Layer Capacitors
Authors: Qi Yanchunxiao , Oh Eun-Suok
Published: December 2020

In recent years, water-based binders have been attracted for electrochemical double-layer capacitor (EDLC) due to their eco-friendly and easy manufacture processing, such as: carboxymethyl cellulose (CMC), Styrene Butadiene Rubber (SBR), poly tetrafluoroethylene (PTFE), etc. Particularly, the combination of CMC and SBR shows better performance than polyvinylidene fluoride (PVdF) which is dissolved in a harmful organic solvent, N-methyl-2-pyrollidone (NMP). Good ionic/electronic conduction of binder can greatly improve the performance of electrode, even though the key factor of binder materials is electrode adhesion. Recently, a new type of two-dimensional material composed of transition metal carbides or nitrides was developed, which is highly electronically conductive. In our research, we synthesized a high adhesive poly(acrylonitrile-co-butylacrylate) on the surface of the two-dimensional conductive materials by emulsion polymerization. This novel conductive water-based binder was applied to EDLC and have a remarkable effect on the electrochemical performance. A variety of characteritics demonstrate that the polymer binder containing 2-dimentional conducting materials can be a good candidate binder for EDLCs, probably lithium ion batteries.
Sodium Ion Hybrid Capacitor in Poly-Acrylic Acid with Vinyl Silica Nano Particle Gel Electrolyte
Authors: Kim Junsu , Park Jeong Hee , Shin Kang Ho , Rana Harpalsinh H. , Park Ho Seok
Published: December 2020

Sodium ion hybrid capacitor (SIHC) has much attention because of abundance of sodium source and low cost. To improve the performance of SIHC stability, the poly-Acrylic Acid (PAA) cross-linked with Vinyl Silica Nano Particle (VSNP) was used as gel electrolyte. The VSNP was used as cross-linker and synthesized by Sol-Gel method with Vinyltriethoxysilane (VTES) to improve the mechanical strength of gel. Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) was used to analyze C=C bond and morphology of VSNP. PAA gel was polymerized by radical polymerizaiotn with VSNP cross-linker. To measure electrochemical property, SIHC was fabricated with Na3V2(PO4)3 (NVP) cathode material and Activated Carbon (YP50F) anode material. Electrochemical Impedance Spectroscopy (EIS) was used to analyze interfaces-contact with electrode and electrolyte. After measure electrochemical property, X-ray Diffraction was measured to characterize the NVP crystallinity. By this research, It can propose the way how apply to flexible sodium ion hybrid capacitor and gel electrolyte SIHC
Li Plating Detection during Extreme Fast Charging of Li-Ion Batteries Using Operando Impedance Spectroscopy
Authors: Brown David Emory , Konz Zachary M. , McShane Eric J. , McCloskey Bryan D.
Published: December 2020

To promote the continued growth of the electric vehicle (EV) market—as well as to improve the performance of other battery-powered technologies such as phones, laptops, and drones—Li-ion battery charging times need to be significantly reduced. At higher charging rates, Li metal may plate on the graphite anode, which is a possible safety concern and leads to decreased cycle life of the battery.1 To date, no work has demonstrated a consistently reliable technique to detect the onset of Li plating in operando.2 Previous work has included dV/dQ analysis of discharge profiles after fast charging,3,4 impedance analysis after fast charging5 and during pseudo-operando measurements,6 dV/dt analysis of voltage relaxation profiles after fast charging,5,6 three electrode graphite potential monitoring,4 and simple optical inspection after many fast charging cycles, among other techniques.2 Our group has also developed ex situ mass spectrometry titrations to detect and quantify electrically isolated Li deposits,7 as well as an improved dV/dt technique to detect the onset of Li plating after fast charging.8

In this work, we use impedance spectroscopy—and specifically the Distribution of Relaxation Times (DRT) analysis method9—to detect in operando the onset of Li plating. There is a change in the graphite interfacial impedance upon Li plating on the graphite surface. Coupled with differential voltage relaxation for cross-validation, we can reliably detect the Li plating onset graphite state of charge (SOC) for rates as high as 6C at room temperature and for different graphite loadings with ~1% graphite capacity sensitivity. Three electrode cell measurements will be shown here, as well as some promising data from more applicable two electrode cells. We also see variation in the impedance for fast versus slow plating, and we discuss possible physical explanations for this behavior. This capability to detect the onset of Li plating allows for the safe implementation of fast charging protocols.

References

Y. Liu, Y. Zhu, and Y. Cui, Nat Energy, 4, 540–550 (2019).

T. Waldmann, B.-I. Hogg, and M. Wohlfahrt-Mehrens, Journal of Power Sources, 384, 107–124 (2018).

K. G. Gallagher, D. W. Dees, A. N. Jansen, D. P. Abraham, and S.-H. Kang, J. Electrochem. Soc., 159, A2029–A2037 (2012).

C. Uhlmann, J. Illig, M. Ender, R. Schuster, and E. Ivers-Tiffée, Journal of Power Sources, 279, 428–438 (2015).

S. Schindler, M. Bauer, M. Petzl, and M. A. Danzer, Journal of Power Sources, 304, 170–180 (2016).

U. R. Koleti, T. Q. Dinh, and J. Marco, Journal of Power Sources, 451, 227798 (2020).

Eric J. McShane et al., ACS Energy Letters, submitted (2020).

Zachary M. Konz, Eric J. McShane, and Bryan D. McCloskey, ACS Energy Letters, submitted (2020).

E. Ivers-Tiffée and A. Weber, J. Ceram. Soc. Japan, 125, 193–201 (2017).
(Invited) Zinc-Deposited Aluminum Electrode Prepared Using Spontaneous Deposition Method for Use in Aqueous Hybrid Capacitors
Authors: Inoue Hiroshi , Takenaka Masakazu , Chiku Masanobu , Higuchi Eiji
Published: December 2020

Aqueous electrolytes have advantages compared to nonaqueous electrolytes, such as high ionic conductivity, nonflammability, low environmental load, low cost, and so on. However, the maximum operating voltages of electric double-layer capacitors (EDLCs) with aqueous electrolytes are much lower than those with nonaqueous electrolytes, which can operate at voltages over 2.5 V, because the former are limited to 1.23 V, the theoretical decomposition voltage of water, leading to low energy and power densities. So, a key to improve energy and power densities is to increase the maximum operating voltage. Hybrid capacitors (HCs), which consists of activated carbon (AC) and redox electrodes, can greatly improve the energy and power densities of EDLCs because of widened potential windows. As for aqueous HCs, metal hydroxides/oxides as a redox positive electrode have realized the maximum operating voltages of 1.4–2.0 V because they have higher potential limits and higher oxygen overpotentials than AC,1-3 leading to higher energy and power densities. In the same manner, we reported that an HC with a Zn negative electrode whose hydrogen overpotential was larger than AC also increased the maximum operating voltage due to the extension of the negative potential limits, leading to low energy and power densities.4 A copper sheet was used as a substrate for zinc electrodeposition in the previous study.4 Aluminum is a light metal and cheap. Since the standard potential of Al is more negative than that of Zn, Zn can be spontaneously deposited on an Al sheet only by immersing it in a zincate solution. In this study, we prepared Zn-deposited Al sheet negative electrodes and evaluated their electrochemical properties and capacitor performance of a HC with the negative electrode.

A polished Al sheet was immersed in a zincate solution to deposit Zn metal spontaneously. After the deposition, the mirror image of the Al sheet was cloudy due to zinc deposits. EDX and XPS analyses showed that Zn deposits covered almost the whole Al surface, indicating that spontaneous deposition of Zn occurred as follows.

2Al + 3Zn(OH)4
2- → 3Zn + 4OH- + 2Al(OH)4
-

Cyclic voltammograms of a Zn/Al electrode were recorded in 7 M KOH aqueous solution containing 0.6 M ZnO. A reduction peak due to Zn deposition and an oxidation peak due to Zn dissolution were observed in cyclic voltammograms, which was similar to a cyclic voltammogram of a Cu electrode in the same electrolyte.

An aqueous HC cell with a Zn/Al negative electrode and AC positive electrode was assembled, and its capacitor performance will be reported.

References

V. Khomenko, E. Raymundo-Piñero, F. Béguin, J. Power Sources, 153, 183 (2006).

T. Cottineau, M. Toupin, T. Brousse, D. Bélanger, Appl. Phys. A: Mater. Sci. Process., 82, 599 (2006).

H. Inoue, Y. Namba, E. Higuchi, J. Power Sources, 195, 6239 (2010).

H. Inoue, T. Morimoto, S. Nohara, Electrochem. Solid-State Lett., 10, A261 (2007).
Additive Manufacturing of Solid Oxide Fuel Cell (AM-SOFC) Stacks
Authors: Zhao Feng , Liao Jared , Zhang Ray
Published: December 2020

The Solid oxide fuel cell (SOFC) is an electrochemical energy-conversion device which offers tremendous promise for delivering high electrical efficiency and significant environmental benefits in terms of fuel flexibility, as well as clean and efficient electric power generation. However, the state-of-the-art SOFC cell currently involves expensive and time-consuming multi-step manufacturing processes including tape casting, screen printing, shaping, lamination, sintering, etc. In addition, SOFC stacks are usually assembled with pre-fabricated cells, metal interconnects, and glass-ceramic sealing. These indispensable components add extra layers of complexity to the stack structure’s fabrication and maintenance, significantly increasing the size and weight of the final product. These intrinsic limitations on the current planar stack cannot be easily removed by traditional manufacturing processes. However, as additive manufacturing (AM) technologies start to mature and show increasing market penetration, it lends itself admirably to breaking the limits on high-power-density SOFC stack manufacturing. Storagenergy’s SOFC project is developing an all-ceramic AM-SOFC by a high-speed AM process of multiple materials. The developed technology allows the fabrication of robust and compact AM-SOFC stacks with unique features such as monolithic architecture with embedded novel micro flow channels and thinner elements (anode, cathode, electrolyte, and interconnect) by only three production steps (3D printing, sintering, and catalyst infiltration) without the need for subsequent assembly of individual layers and indispensable components. This simplification of the fabrication process is expected to reduce the cost of the SOFC and increase SOFC design flexibility and manufacturing reliability.
Kinetic Analysis of Electrochemical Lactonization of Ketones Using Water As the Oxygen Atom Source
Authors: Maalouf Joseph , Jin Kyoungsuk , Yang Dengtao , Limaye Aditya M , Manthiram Karthish
Published: December 2020

Lactones serve as key synthetic intermediates for the large-scale production of several important chemicals, such as polymers, pharmaceuticals, and scents. Current thermochemical methods for the formation of some lactones rely on molecular oxidants, which yield stoichiometric side products that result in a poor atom economy and impose safety hazards when in contact with organic substrates and solvents. Electrochemical synthesis can alleviate these concerns by exploiting an applied potential to enable the possibility of a clean and safe route for lactonization. In this study, we investigated the mechanism of electrochemical lactone formation from cyclic ketones. When using a platinum anode and cathode in acetonitrile with 10 M H2O and 400 mM cyclohexanone, we found that non-Baeyer-Villiger products, δ-hexanolactone and ɣ-caprolactone, are formed with a total Faradaic efficiency of ~20%. Isotope labeling experiments support that water is the oxygen atom source for this reaction. In addition, electrochemical kinetic data suggest a 1st order dependence on water at low water concentrations (<2 M H2O) and a 0th order dependence on the substrate, cyclohexanone. A Tafel slope of 139 mV/decade was measured at 400 mM cyclohexanone and 10 M H2O, implying an initial electron transfer as the rate determining step. Literature proposed mechanisms for similar transformations suggest an outer sphere pathway. However, based on the collected electrochemical kinetic data, we propose the possibility that Pt reacts with water in an initial electron transfer that forms Pt-OH, which can subsequently react with the ketone substrate. A subsequent electron transfer forms a ring opened carboxylic acid cation that can reclose to form either of the observed five- or six-member ring lactone products.
Highly Efficient Electrochemical Oxidation of Alcohols in a Flow Electrochemical Column Cell Modified with Au Nanoparticle Catalyst
Authors: Suga Tatsuya , Tanaka Kenta , Atobe Mahito
Published: December 2020

Electrosynthesis is a powerful means for obtaining a variety of useful chemical products without employing toxic or otherwise hazardous chemical reagents and under relatively mild conditions. However, conventional batch-type cells suffer from a low productivity due to narrow two-dimensional reaction fields in the electrochemical system. To overcome this problem, we utilized continuous-flow column cell[1]. Although it was developed for a highly sensitive coulometric analysis of trace chemical substances in 1968, it is also expected to conduct rapid and quantitative bulk electrolysis due to its large electrode area and continuous-flow system. This flow cell consisted of a working electrode compartment and a counter electrode compartment, separated by an ion permeable Vycor® glass tube (Figure 1 (a)). A bundle of carbon fiber threads was tightly packed as a working electrode in the continuous-flow column cell, and a Pt spiral wire was used as a counter electrode. During several decades, the bulk gold has been considered as less active material, but at nanoscale, it exhibits surprisingly physicochemical and catalytic properties[2]. Therefore, in this work, the carbon fiber surface was also functionalized with Au nanoparticle catalyst to promote an electrochemical oxidation of alcohols.

As a result, we have successfully demonstrated an efficient electrocatalytic oxidation of benzyl alcohol to provide benzaldehyde and benzoic acid with high current efficiencies in alkaline media. Moreover, it was also found that the selectivity of benzaldehyde was influenced by the added base amounts, and increased up to 97% by decreasing the amounts. We will also report the results of electrochemical oxidation of other alcohols.

References

[1] F. Kusu, et al., DENKI KAGAKU, 1997, 65, 51-56.

[2] M. Rossi, Chem. Soc. Rev., 2008, 37, 2077-2095.

Figure 1
(Keynote) Continuous Glucose Monitoring Systems - Current Status and Future Perspectives of the Flagship Technologies in Biosensor Research -
Authors: Sode Koji
Published: December 2020

The history of the development of glucose sensors is synonym of the history of biosensor research. Glucose sensors created the past and current largest market in the industrialized biosensors. The most of the commercially available glucose sensors have been dedicated to the disposable sensor strips for self-monitoring of blood glucose (SMBG), thereby diabetic patients know which treatments and amounts of treatments to self-administer and to learn how activities affect their blood glucose levels. Currently, continuous glucose monitoring (CGM) systems have been recognized as the ideal monitoring systems for glycemic control of diabetic patients, expecting the replacement of SMBG sensors. Glucose monitoring using SMBG sensors requires taking tiny blood sample using a “lancet” to prick your finger or some other alternate sites for testing, whereas CGM systems monitor glucose level at interstitial fluid (ISF) where CGM sensor is inserted. At present, the glucose concentration in blood and ISF samples are recognized as the clinically relevant values. In 2018, the U.S. Food and Drug Administration (FDA) approved a medical device comprising CGM system, a continuous subcutaneous insulin infusion pump and a control algorithm that can supply an appropriate amount of basal insulin based on the CGM results as an artificial pancreas. Consequently, it became possible to automatically and continuously control the blood glucose level. In 2019, synthetic receptor employing long-term implantable CGM system, was approved as the prescription device, which realized up to 90 days (180 days in Europe) operation. These technological achievements boosted up CGM systems and sensors as the flagship technologies in the biosensor research.

In this presentation, I will overview the current status and future perspectives of sensors for CGM systems.
(Keynote) Real-Time Biosensors for Continuous Measurements of Biomolecules in Live Subjects
Authors: Soh Hyongsok Tom
Published: December 2020

A biosensor capable of continuously measuring specific molecules in vivo would provide a valuable window into patients’ health status and their response to therapeutics. Unfortunately, continuous, real-time molecular measurement is currently limited to a handful of analytes (i.e. glucose and oxygen) and these sensors cannot be generalized to measure other analytes. In this talk, we will present a biosensor technology that can be generalized to measure a wide range of biomolecules in living subjects. To achieve this, we develop synthetic antibodies (aptamers) that change its structure upon binding to its target analyte and produce an electrochemical current or emit light. Our real-time biosensor requires no exogenous reagents and can be readily reconfigured to measure different target analytes by exchanging the aptamer probes in a modular manner. Using our real-time biosensor, we demonstrate the first closed loop feedback control of drug concentration in live animals and discuss potential applications of this technology. Finally, we will discuss methods for generating the aptamer probes which are at the heart of this biosensor technology.
(Keynote) DT-Diaphorase As a Promising Catalytic Label for Rapid and Sensitive Immunosensors
Authors: Yang Haesik
Published: December 2020

The most common enzyme labels in biosensors are alkaline phosphatase (ALP) and horseradish peroxidase (HRP), which, however, have some limitations for use in electrochemical immunosensors. DT-diaphorase (DT-D) is a redox enzyme that catalyzes a two-electron reduction of quinone in the presence of NADH or NADPH. Importantly, DT-D from Bacillus stearothermophilus (EC 1.6.99.-) has a low molecular weight (30 kDa) and high thermal and long-term stability. Nevertheless, DT-D has never been employed as a catalytic label in biosensors. In this presentation, we report that DT-D can be used as a bifunctional enzyme label for rapid and sensitive electrochemical immunosensors: DT-D can convert an electrochemically inactive substrate into an electrochemically active product and DT-D can participate in electrochemical-chemical (EC) and electrochemical-enzymatic (EN) redox cycling induced by the product. We found that DT-D has high catalytic activities for nitroso reduction, phosphoester hydrolysis, and carboxyl ester hydrolysis as well as quinone reduction in the presence of NADH. 4-Nitroso-1-naphthol, 1-amino-2-naphthyl phosphate, and 4-aminonaphthalene-1-yl acetate are used as electrochemically inactive substrates for corresponding enzymatic reactions, which are converted into electrochemically active aminohydroxy-naphthalenes. This combination of DT-D and the substrates allows for high electrochemical signal-to-background ratios, because (i) the catalytic reaction by DT-D is fast, (ii) the electrochemical oxidation of the aminohydroxy-naphthalenes is rapid, even at an indium-tin oxide electrode, and (iii) two redox cycling processes significantly increase the electrochemical signal. The electrochemical immunosensor using DT-D and 4-nitroso-1-naphthol detects parathyroid hormone with a low detection limit of 2 pg/mL, the immunosensor using DT-D and 1-amino-2-naphthyl phosphate detects outer membrane vesicles from Escherichia coli with a detection limit of 8 ng/mL, and the immunosensor using DT-D and 4-aminonaphthalene-1-yl acetate detects thyroid-stimulating hormone with a detection limit of ~2 pg/mL. DT-D may be used as a catalytic label in sensitive and stable bioassays instead of common ALP and HRP.

References

1. P. Nandhakumar, A. M. Ichzan, N.-S. Lee, Y. H. Yoon, S. Ma, S. Kim, H. Yang, ACS Sens. in press.

2. A. Bhatia, P. Nandhakumar, G. Kim, J. Kim, N.-S. Lee, Y. H. Yoon, H. Yang, ACS Sens. 4, 1641 (2019)

3. A. M. Ichzan, S. Lee, C. S. Fang, P. Nandhakumar, H. Ha, J. M. Joo, K. Kim, H. Yang, Anal. Chem. 91, 4680 (2019)

4. P. Nandhakumar, A.-M. J. Haque, N.-S. Lee, Y. H. Yoon, H. Yang, Anal. Chem. 90, 10982 (2018)

5. C. Kang, J. Kang, N.-S. Lee, Y. H. Yoon, H. Yang, Anal. Chem. 89, 7974 (2017)
Addition of Carbon Nanodots for Improving Charge/Discharge Characteristics of Lithium Metal Anode
Authors: Takee Kazuki , Momma Toshiyuki , Nara Hiroki , Osaka Tetsuya
Published: December 2020

Lithium metal is considered as the most promising anode material for high-energy-batteries due to its high theoretical capacity and low electrochemical potential. However, dendrite formation due to uncontrollable Li growth during cycling is a major challenge. Lithium dendrite growth leads to low coulombic efficiency, short cycle life, and safety issues. To solve the problem, addition of 2D carbon nano material that lead uniform Li deposition has been reported[1]. Here, we report carbon nanodots (CND) as an electrolyte additive which can suppress dendrite growth and keep stable Li metal deposition/dissolution process. CND has defect sites and functional groups that attract Li ions and serve as a Lithiophilic nucleation site for uniform nucleation.

Electrochemical properties were evaluated with the charge / discharge cycles of Li symmetric cell in Li(G3)TFSI/HFE electrolyte in Fig. 1 Voltage drop that seems to be short circuit was confirmed in 88 cycles without CND. On the other hand, no short circuit was confirmed for 100 cycles with CND, confirming an improvement of cycle life. In addition, with CND, it showed lower overpotential than that of without CND which was suggested low film resistance. Fig. 2 shows the coulombic efficiency of Cu/Li half cell. Without CND, unstable CE was confirmed after 50 cycle. It is considered that the irreversible capacity due to side reaction and dead lithium caused a CE reduce. With CND, it showed stable and high CE (> 95 %) for 100 cycles. It was suggested that excessive side reactions and dead lithium were suppressed by the CND addition. It is obviously indicated that addition of CND contributes to improvement of cycle ability and coulombic efficiencies for lithium metal anode.

Reference

[1] X. Cheng, et al. Nature communications, 8, 336 (2017).

Figure 1
Parity Effects in the Physicochemical Properties of Self-Assembled Monolayers
Authors: Badia Antonella , Dionne Eric , Ben Amara Fadwa , Pellerin Christian
Published: December 2020

Large-area metal/molecule/metal junctions based on self-assembled monolayers (SAMs) of organothiolates are of interest for investigations of charge transport across ultrathin organic films and the fabrication of molecular electronic devices. Several recent reports demonstrate an odd-even dependency in the rate of charge transport through SAMs of the insulating n-alkanethiolates (CH3C
n
S)1,2 or the redox-active ferrocenylalkanethiolates (FcC
n
S)3. This parity effect has been attributed to differences in the orientation of the terminal functional group and alkyl chain packing in SAMs consisting of an odd versus even number of methylene repeat units.

We have sought experimental evidence for odd-even distinctions in the molecular organization of these SAMs using infrared reflection-adsorption spectroscopy (IRRAS), electrochemistry, and contact angle goniometry. The findings of the investigations will be presented in this talk and the molecular origin of the parity effect of SAM macroscopic properties will be discussed.

References:

1. Baghbanzadeh, M.; Simeone, F. C.; Bowers, C. M.; Liao, K.-C.; Thuo, M.; Baghbanzadeh, M.; Miller, M. S.; Carmichael, T. B.; Whitesides, G. M., Odd–Even Effects in Charge Transport across n-Alkanethiolate-Based SAMs. J. Am. Chem. Soc. 2014, 136, 16919- 16925.

2. Chen, J.; Giroux, T. J.; Nguyen, Y.; Kadoma, A. A.; Chang, B. S.; VanVeller, B.; Thuo, M. M., Understanding Interface (Odd–Even) Effects in Charge Tunneling using a Polished EGaIn Electrode. Phys. Chem. Chem. Phys. 2018, 20, 4864-4878.

3. Thompson, D.; Nijhuis, C. A., Even the Odd Numbers Help: Failure Modes of SAM-Based Tunnel Junctions Probed via Odd-Even Effects Revealed in Synchrotrons and Supercomputers. Acc. Chem. Res. 2016, 49, 2061-2069.
MiR-429 Involves in the Pathogenesis of Colorectal Cancer via Directly Targeting LATS2
Authors: Chen Xia , Wang Ai-li , Liu Yuan-yuan , Zhao Chen-xi , Zhou Xue , Liu Hai-long , Lin Mo-bin
Published: December 2020

Colorectal cancer (CRC) is a leading cause of cancer-related death around the world whose recurrence and metastasis rate is high. Due to the underlying unclear pathogenesis, it is hard so far to predict the tumorigenesis and prevent its recurrence. YAP/TAZ has been reported to be activated and functioned as a potential oncogene in multiple cancer types and proved to be essential for the carcinogenesis of most solid tumors. In the present study, we found that YAP/TAZ was markedly upregulated in CRC tissues comparing with the adjacent noncancerous tissues due to the downregulation of LATS2, the main upstream regulator. We further identified miR-429 as a direct regulator of LATS2-YAP/TAZ activation, suggesting that the miR-429-LATS2-YAP/TAZ might be novel effective diagnostic axis and therapeutic targets for CRC.
Research on the Large Deformation Prediction Model and Supporting Measures of Soft Rock Tunnel
Authors: Rao Junying , Tao Yonghu , Xiong Peng , Nie Chongxin , Peng Hao , Xue Yanghao , Xi Zuowei
Published: December 2020

The weak surrounding rock has the characteristics of easy softening, poor integrity, low mechanical strength, etc., which makes it easy to induce different degrees of deformation and damage under excavation disturbance and then seriously affects the stability of the tunnel. Carrying out soft rock tunnel deformation prediction research and designing the supporting structure according to the predicted value is of great significance to engineering construction and design. Based on the grey theory, the large deformation of the vault, shoulder, and waist of the soft rock tunnel are predicted, and then the specific bolt support is designed in the maximum predicted value (Smax·R) area. The control effects of different bolts, spacing (d), length (L) on the maximum displacement (Smax·M), and maximum stress (σmax·M) the surrounding rock are analyzed by numerical simulation. Results show that the gray model has high prediction accuracy, the best prediction time is one week, and the maximum error is only 2.99%; with the decrease in d, resin bolt support has a significant supporting effect compared with mortar bolt support, with Smax.M and σmax·M reduced by 64.38% and 10.35%, respectively; as the L of bolt increases, compared with the mortar bolt support, the resin bolt support has a more obvious restraining effect on the surrounding rock deformation, and Smax·M and σmax·M are reduced by 28.20% and 10.00%, respectively; when 4.5 m < L < 6.0 m and 0.6 m < d < 0.7 m, resin bolt support should be adopted; in other ranges, mortar bolt support or resin bolt support has a less significant difference in controlling surrounding rock deformation.
Genetic Variability of Antioxidative Mechanisms and Cardiotoxicity after Adjuvant Radiotherapy in HER2-Positive Breast Cancer Patients
Authors: Marinko Tanja , Stojanov Konda Jakob Timotej , Dolžan Vita , Goričar Katja
Published: December 2020

Background. Breast cancer treatment is associated with the occurrence of various cardiac adverse events. One of the mechanisms associated with cardiotoxicity is oxidative stress, against which cells are protected by antioxidative enzymes. Genetic variability of antioxidative enzymes can affect enzyme activity or expression, which modifies the ability of cells to defend themselves against oxidative stress and could consequently contribute to the occurrence of treatment-related cardiotoxicity. Our aim was to evaluate the association of common polymorphisms in antioxidative genes with cardiotoxicity after adjuvant radiotherapy (RT) in HER2-positive breast cancer patients. Methods. Our retrospective study included 101 HER2-positive early breast cancer patients who received trastuzumab and adjuvant RT. We isolated DNA from buccal swabs and used competitive allele-specific PCR for genotyping of PON1 rs854560 and rs662, GSTP1 rs1138272 and rs1695, SOD2 rs4880, CAT rs1001179, and HIF1 rs1154965 polymorphisms. N-terminal pro B-type natriuretic peptide (NT-proBNP), left ventricular ejection fraction, and NYHA class were used as markers of cardiotoxicity. We used logistic regression to evaluate the association of genetic factors with markers of cardiotoxicity. Results. Carriers of at least one polymorphic PON1 rs854560 allele were less likely to have increased NT-proBNP (

OR
=
0.34

; 95% CI = 0.15-0.79;

P
=
0.012

), even after adjustment for age (

OR
=
0.35

; 95% CI = 0.15-0.83;

P
=
0.017

). Carriers of at least one polymorphic PON1 rs662 allele were more likely to have increased NT-proBNP (

OR
=
4.44

; 95% CI = 1.85-10.66;

P
=
0.001

), even after adjustment for age (

OR
=
5.41

; 95% CI = 2.12-13.78;

P
<
0.001

). GSTP1 rs1695 was also associated with decreased NT-proBNP in the multivariable analysis (

P
=
0.026

), while CAT rs1001179 was associated with NYHA class in the univariable (

P
=
0.012

) and multivariable analysis (

P
=
0.023

). Conclusion. In our study, polymorphisms PON1 rs662 and rs854560, CAT rs1001179, and GSTP1 rs1695 were significantly associated with the occurrence of cardiac adverse events after adjuvant RT and could serve as biomarkers contributing to treatment personalization.
A Traceable and Revocable Multiauthority Attribute-Based Encryption Scheme with Fast Access
Authors: Zhang Kai , Li Yanping , Song Yun , Lu Laifeng , Zhang Tao , Jiang Qi
Published: December 2020

Multiauthority ciphertext-policy attribute-based encryption (MA-CP-ABE) is a promising technique for secure data sharing in cloud storage. As multiple users with same attributes have same decryption privilege in MA-CP-ABE, the identity of the decryption key owner cannot be accurately traced by the exposed decryption key. This will lead to the key abuse problem, for example, the malicious users may sell their decryption keys to others. In this paper, we first present a traceable MA-CP-ABE scheme supporting fast access and malicious users’ accountability. Then, we prove that the proposed scheme is adaptively secure under the symmetric external Diffie–Hellman assumption and fully traceable under the

q

-Strong Diffie–Hellman assumption. Finally, we design a traceable and revocable MA-CP-ABE system for secure and efficient cloud storage from the proposed scheme. When a malicious user leaks his decryption key, our proposed system can not only confirm his identity but also revoke his decryption privilege. Extensive efficiency analysis results indicate that our system requires only constant number of pairing operations for ciphertext data access.
Knockdown of nrf2 Exacerbates TNF-α-Induced Proliferation and Invasion of Rheumatoid Arthritis Fibroblast-Like Synoviocytes through Activating JNK Pathway
Authors: Du Yu , Wang Qian , Tian Na , Lu Meng , Zhang Xian-Long , Dai Sheng-Ming
Published: December 2020

Fibroblast-like synoviocytes (FLS) in the synovial tissue of rheumatoid arthritis (RA) exhibit over-proliferative and aggressive phenotypes, which participate in the pathophysiology of RA. In RA, little is known about the nonantioxidant effect of nuclear factor erythroid 2-related factor 2 (nrf2), the master regulator of redox homeostasis. In this study, we aimed to explore the expression and upstream regulatory factors of nrf2 and revealed its functions in modulating the proliferation and invasion in RA-FLS. FLS were isolated from RA and osteoarthritis patients. Expression of nrf2 in the synovial tissues and FLS was analyzed by immunohistochemistry, real-time PCR, Western blotting, and immunofluorescence staining. Cell proliferation was examined by Cell Counting Kit-8. Cell invasion was tested by transwell assay. Phosphorylation of JNK was determined by Western blotting. The results showed that nrf2 expression in the RA synovial tissues was upregulated. TNF-α promoted expression and nuclear translocation of nrf2 in RA-FLS and increased the intracellular reactive oxygen species (ROS) level. Nrf2 nuclear translocation was blocked by ROS inhibitor N-acetylcysteine. Both knockdown of nrf2 by siRNA and inhibition of nrf2 by ML385 significantly promoted the TNF-α-induced proliferation and invasion of RA-FLS. Activation of nrf2 by sulforaphane (SFN) profoundly inhibited the TNF-α-induced proliferation and invasion of RA-FLS. Knockdown of nrf2 also enhanced the TNF-α-induced matrix metalloproteinases (MMPs) expression and phosphorylation of JNK in RA-FLS. Proliferation and invasion of RA-FLS incubated with TNF-α and nrf2 siRNA were inhibited by pretreatment with JNK inhibitor SP600125. In conclusion, nrf2 is overexpressed in synovial tissues of RA patients, which may be promoted by TNF-α and ROS levels. Activation of nrf2 may suppress TNF-α-induced proliferation, invasion, and MMPs expression in RA-FLS by inhibiting JNK activation, indicating that nrf2 plays a protective role in relieving the severity of synovitis in RA. Our results might provide novel insights into the treatment of RA.
Low-Frequency Carbody Sway Modelling Based on Low Wheel-Rail Contact Conicity Analysis
Authors: Wu Yi , Zeng Jing , Qu Sheng , Shi Huailong , Wang Qunsheng , Wei Lai
Published: December 2020

Low-frequency carbody swaying on China’s high-speed trains is not only an impediment to ride comfort but it may also be an operational risk under some extreme situations. To study the mechanism and mitigate the carbody swaying problem for high-speed trains, a multibody dynamics model was established based on both linear and nonlinear analyses. Whilst it is generally assumed that carbody swaying is predominantly caused by carbody hunting motion, the results in this paper has shown that, under certain boundary conditions, bogie-hunting motion can also lead to low-frequency carbody swaying. This low-frequency swaying phenomenon was also found to be caused by the excessively low wheel-rail contact or mismatched suspension parameters. Parametric optimization analysis was accordingly conducted from the perspective of the wheel-rail contact relationship and the suspension system. The analysis indicated that although optimizing the suspension parameters can meet the requirement of vehicle stability, bogie's vibration worsen when the wheel profiles wear over time. Overall, while rail reprofiling was found to be one of the fundamental solutions to mitigate carbody swaying, it is cost prohibitive for most routine operational applications. Thus, for economic considerations and the fact that low wheel-rail contact conicity is also a contributing factor to carbody swaying, vehicles with worn wheels can also be operated on the rail line, which was successfully verified by the field data presented in this paper.
Circulating Monocytic Myeloid-Derived Suppressor Cells Are Elevated and Associated with Poor Prognosis in Acute Myeloid Leukemia
Authors: Wang Huiping , Tao Qianshan , Wang Zhitao , Zhang Qing , Xiao Hao , Zhou Mei , Dong Yi , Zhai Zhimin
Published: December 2020

Background. Monocytic myeloid-derived suppressor cells (M-MDSCs) characterized with the phenotype of CD14+HLA-DRlow/- have attracted a lot of attention in the field of human tumor immunology. However, little is known about the roles of M-MDSCs in acute myeloid leukemia (AML) as opposed to their multiple roles in solid tumors. Methods. We examined the frequencies of M-MDSCs identified for CD14+HLA-DRlow/- by flow cytometry in the peripheral circulating blood of 109 newly diagnosed adult patients with AML and 30 healthy controls (HC). Then, we, respectively, validated the clinic significance of circulating M-MDSCs on the relevance of spectral features for diagnostic stratification, induction therapy response, treatment effect maintenance, and long-term survival in AML. Results. Circulating M-MDSC frequencies of AML were significantly higher than those of HC both in CD14+ monocytes (46.22%±2.95%vs.1.07%±0.17%,p<0.01) and peripheral blood mononuclear cells (PBMCs) (4.21%±0.80%vs.0.17%±0.03%,p<0.01). Elevated circulating M-MDSCs in patients with AML were significantly associated with low complete remission (CR) rate, high relapse/refractory rate, and poor long-term survival, but had no correlation with common clinic risks and cytogenetic molecular risk categories. Conclusions. It was demonstrated that circulating M-MDSCs are elevated and associated with poor prognosis in AML, suggesting M-MDSCs might be a prognostic indicator for AML.
The Potential Role of Regulatory B Cells in Idiopathic Membranous Nephropathy
Authors: Dong Zhaocheng , Liu Zhiyuan , Dai Haoran , Liu Wenbin , Feng Zhendong , Zhao Qihan , Gao Yu , Liu Fei , Zhang Na , Dong Xuan , Zhou Xiaoshan , Du Jieli , Huang Guangrui , Tian Xuefei , Liu Baoli
Published: December 2020

Regulatory B cells (Breg) are widely regarded as immunomodulatory cells which play an immunosuppressive role. Breg inhibits pathological autoimmune response by secreting interleukin-10 (IL-10), transforming growth factor-β (TGF-β), and adenosine and through other ways to prevent T cells and other immune cells from expanding. Recent studies have shown that different inflammatory environments induce different types of Breg cells, and these different Breg cells have different functions. For example, Br1 cells can secrete IgG4 to block autoantigens. Idiopathic membranous nephropathy (IMN) is an autoimmune disease in which the humoral immune response is dominant and the cellular immune response is impaired. However, only a handful of studies have been done on the role of Bregs in this regard. In this review, we provide a brief overview of the types and functions of Breg found in human body, as well as the abnormal pathological and immunological phenomena in IMN, and propose the hypothesis that Breg is activated in IMN patients and the proportion of Br1 can be increased. Our review aims at highlighting the correlation between Breg and IMN and proposes potential mechanisms, which can provide a new direction for the discovery of the pathogenesis of IMN, thus providing a new strategy for the prevention and early treatment of IMN.