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1.
Accid Anal Prev ; 201: 107571, 2024 Jun.
Article En | MEDLINE | ID: mdl-38608507

Drivers' risk perception plays a crucial role in understanding vehicle interactions and car-following behavior under complex conditions and physical appearances. Therefore, it is imperative to evaluate the variability of risks involved. With advancements in communication technology and computing power, real-time risk assessment has become feasible for enhancing traffic safety. In this study, a novel approach for evaluating driving interaction risk on freeways is presented. The approach involves the integration of an interaction risk perception model with car-following behavior. The proposed model, named the driving risk surrogate (DRS), is based on the potential field theory and incorporates a virtual energy attribute that considers vehicle size and velocity. Risk factors are quantified through sub-models, including an interactive vehicle risk surrogate, a restrictions risk surrogate, and a speed risk surrogate. The DRS model is applied to assess driving risk in a typical scenario on freeways, and car-following behavior. A sensitivity analysis is conducted on the effect of different parameters in the DRS on the stability of traffic dynamics in car-following behavior. This behavior is then calibrated using a naturalistic driving dataset, and then car-following predictions are made. It was found that the DRS-simulated car-following behavior has a more accurate trajectory prediction and velocity estimation than other car-following methods. The accuracy of the DRS risk assessments was verified by comparing its performance to that of traditional risk models, including TTC, DRAC, MTTC, and DRPFM, and the results show that the DRS model can more accurately estimate risk levels in free-flow and congested traffic states. Thus the proposed risk assessment model provides a better approach for describing vehicle interactions and behavior in the digital world for both researchers and practitioners.


Accidents, Traffic , Automobile Driving , Humans , Automobile Driving/psychology , Risk Assessment/methods , Accidents, Traffic/prevention & control , Models, Theoretical , Automobiles , Risk Factors
2.
PLoS One ; 19(4): e0297381, 2024.
Article En | MEDLINE | ID: mdl-38635828

The new thermal insulating shotcrete is of great significance for the management of thermal damage in deep mines, and its own strength has a greater impact on the roadway insulation and safe production, so it is very necessary to study the shear strength of the new thermal insulating shotcrete under the influence of the deep hot and humid environment and the stress of mining. For the heat-insulating shotcrete, firstly, we carried out the concrete variable angle shear test under different loading rates, which concluded that the shear rate and peak shear stress showed a trend of increasing and then decreasing; as the angle increases, the different rates have a greater impact on the peak shear stress of the specimen. Secondly, the concrete variable angle shear test was carried out under the temperature and humidity cycle, which revealed that the shear strength of thermal insulated shotcrete increased firstly and then decreased with the increase of temperature at the same number of cycles. Finally, the empirical equations between the cohesive force c, the angle of internal friction ϕ and the number of warm and wet cycles n and the temperature of warm and wet cycles T are fitted with the MATLAB software respectively, and the research results provide technical references for the management of geothermal temperature in deep well projects.


Hot Temperature , Temperature , Humidity , Stress, Mechanical
3.
Plant J ; 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38647454

Uncovering the function of phytopathogen effectors is crucial for understanding mechanisms of pathogen pathogenicity and for improving our ability to protect plants from diseases. An increasing number of effectors have been predicted in various plant pathogens. Functional characterization of these effectors has become a major focus in the study of plant-pathogen interactions. In this study, we designed a novel screening system that combines the TMV (tobacco mosaic virus)-GFP vector and Agrobacterium-mediated transient expression in the model plant Nicotiana benthamiana. This system enables the rapid identification of effectors that interfere with plant immunity. The biological function of these effectors can be easily evaluated by observing the GFP fluorescence signal using a UV lamp within just a few days. To evaluate the TMV-GFP system, we initially tested it with well-described virulence and avirulence type III effectors from the bacterial pathogen Ralstonia solanacearum. After proving the accuracy and efficiency of the TMV-GFP system, we successfully screened a novel virulence effector, RipS1, using this approach. Furthermore, using the TMV-GFP system, we reproduced consistent results with previously known cytoplasmic effectors from a diverse array of pathogens. Additionally, we demonstrated the effectiveness of the TMV-GFP system in identifying apoplastic effectors. The easy operation, time-saving nature, broad effectiveness, and low technical requirements of the TMV-GFP system make it a promising approach for high-throughput screening of effectors with immune interference activity from various pathogens.

4.
Chem Commun (Camb) ; 60(29): 3926-3929, 2024 Apr 04.
Article En | MEDLINE | ID: mdl-38497367

A novel Au-allenylidene promoted decarboxylative annulation by intramolecular α-nucleophilic addition has been disclosed. The unsaturated cyclic ethynylethylene carbamates/carbonates can be converted to unique nucleophiles attached with alkylidene ketenes by sequential decarboxylation and oxidation processes. Such alkylidene ketenes can be rapidly trapped by intramolecular α-attacking annulation to generate potential biological active unsaturated γ-lactams/lactones with broad scope, facile post-modification, high regioselectivity and efficiency.

5.
Small ; : e2309823, 2023 Dec 18.
Article En | MEDLINE | ID: mdl-38109127

Electrocatalysts with low Pt loading mass to achieve high current density (≥1 A cm-2 ) for hydrogen evolution reaction (HER) are still extremely challenging due to the limited intrinsic activity and weak stability of catalytic sites. The modulation of the electronic microenvironment of the support-Pt structure is crucial to enhance the intrinsic activity and stability of catalytic sites. Herein, an innovative titanium oxycarbide (TiV CO) solid solution with Ti vacancies (TiV ) is proposed as support to anchor sub-nanoscale Pt atomic clusters (Pt ACs) and a stable "TiV -Pt ACs" structure is carefully designed. The electronic microenvironment of "TiV -Pt ACs" is indirectly optimized by an unsaturated C/O site near TiV . Thanks to this, novel "TiV -Pt ACs" structure (Pt@TiV CO) with low Pt loading mass (2.44 wt.%) exhibits excellent HER activity in acidic solution and the mass activity is more than ten times that of commercial 20% Pt/C at the overpotentials of 50 and 100 mV. Particularly, Pt@TiV CO shows amazing stability at high and fluctuating current density of 1-2 A cm-2 for 120 h. This work provides a novel and promising method to develop stable and low-loading Pt-based catalysts adapting to high current density.

6.
Langmuir ; 39(47): 16807-16811, 2023 Nov 28.
Article En | MEDLINE | ID: mdl-37956213

We report spectroscopic measurements of the local pH and pKa at an electrode/electrolyte interface using surface enhanced Raman scattering (SERS) spectroscopy of 4-mercaptobenzoic acid (4-MBA). In acidic and basic solutions, the protonated and deprotonated carboxyl functional groups at the electrode surface exist in the solution as -COOH and -COO-, which have different Raman active vibrational features at around 1697 and 1414 cm-1, respectively. In pH neutral water, as the applied electrochemical potential is varied from negative to positive, the acidic form of the 4-MBA (i.e., -COOH) decreases in Raman intensity and the basic form (i.e., -COO-) increases in Raman intensity. The change in local ion concentration is due to the application of electrochemical potentials and the accumulation of ions near the electrode surface. Under various applied potentials, the ratio of 1697 and 1587 cm-1 (pH-independent) peak areas spans the range between 0.7 and 0, and the ratio of the 1414 and 1587 cm-1 peak areas ranges from 0 to 0.3. By fitting these data to a normalized sigmoid function, we obtain the percentage of surface protonation/deprotonation, which can be related to the pKa and pH of the system. Thus, we can measure the local pKa at the electrode surface using the surface enhanced Raman signal of the 4-MBA.

7.
Adv Mater ; 35(35): e2303943, 2023 Sep.
Article En | MEDLINE | ID: mdl-37402138

Al batteries have great potential for renewable energy storage owing to their low cost, high capacity, and safety. High energy density and adaptability to fluctuating electricity are major challenges. Here, a lightweight Al battery for fast storage of fluctuating energy is constructed based on a novel hierarchical porous dendrite-free carbon aerogel film (CAF) anode and an integrated graphite composite carbon aerogel film (GCAF) cathode. A new induced mechanism by the O-containing functional groups on the CAF anode is con-firmed for uniform Al deposition. The GCAF cathode possesses a higher mass utilization ratio due to the extremely high loading mass (9.5-10.0 mg cm-2 ) of graphite materials compared to conventional coated cathodes. Meanwhile, the volume expansion of the GCAF cathode is almost negligible, resulting in better cycling stability. The lightweight CAF‖GCAF full battery can adapt well to large and fluctuating current densities owing to its hierarchical porous structure. A large discharge capacity (115.6 mAh g-1 ) after 2000 cycles and a short charge time (7.0 min) at a high current density are obtained. The construction strategy of lightweight Al batteries based on carbon aerogel electrodes can promote the breakthrough of high-energy-density Al batteries adapted to the fast storage of fluctuating renewable energy.

8.
Nat Mater ; 22(11): 1294-1303, 2023 Nov.
Article En | MEDLINE | ID: mdl-37500958

Textiles represent a fundamental material format that is extensively integrated into our everyday lives. The quest for more versatile and body-compatible wearable electronics has led to the rise of electronic textiles (e-textiles). By enhancing textiles with electronic functionalities, e-textiles define a new frontier of wearable platforms for human augmentation. To realize the transformational impact of wearable e-textiles, materials innovations can pave the way for effective user adoption and the creation of a sustainable circular economy. We propose a repair, recycle, replacement and reduction circular e-textile paradigm. We envisage a systematic design framework embodying material selection and biofabrication concepts that can unify environmental friendliness, market viability, supply-chain resilience and user experience quality. This framework establishes a set of actionable principles for the industrialization and commercialization of future sustainable e-textile products.

9.
Front Oncol ; 13: 1185991, 2023.
Article En | MEDLINE | ID: mdl-37284198

Background/objective: We retrospectively analyzed the effective and safety of continuous low-dose cyclophosphamide combined with prednisone (CP) in relapsed and refractory multiple myeloma (RRMM) patients with severe complications. Methods: A total of 130 RRMM patients with severe complications were enrolled in this study, among which 41 patients were further given bortezomib, lenalidomide, thalidomide or ixazomib on the basis of CP regimen (CP+X group). The response to therapy, adverse events (AEs), overall survival (OS) and progression-free survival (PFS) were recorded. Results: Among the 130 patients, 128 patients received therapeutic response assessment, with a complete remission rate (CRR) and objective response rate (ORR) of 4.7% and 58.6%, respectively. The median OS and PFS time were (38.0 ± 3.6) and (22.9±5.2) months, respectively. The most common AEs were hyperglycemia (7.7%), pneumonia (6.2%) and Cushing's syndrome (5.4%). In addition, we found the pro-BNP/BNP level was obviously decreased while the LVEF (left ventricular ejection fraction) was increased in RRMM patients following CP treatment as compared with those before treatment. Furthermore, CP+X regimen further improved the CRR compared with that before receiving the CP+X regimen (24.4% vs. 2.4%, P=0.007). Also, both the OS and PFS rates were significantly elevated in patients received CP+X regimen following CP regimen as compared with the patients received CP regimen only. Conclusion: This study demonstrates the metronomic chemotherapy regimen of CP is effective to RRMM patients with severe complications.

10.
Asian J Pharm Sci ; 18(3): 100812, 2023 May.
Article En | MEDLINE | ID: mdl-37274921

Biopolymers are promising environmentally benign materials applicable in multifarious applications. They are especially favorable in implantable biomedical devices thanks to their excellent unique properties, including bioactivity, renewability, bioresorbability, biocompatibility, biodegradability and hydrophilicity. Additive manufacturing (AM) is a flexible and intricate manufacturing technology, which is widely used to fabricate biopolymer-based customized products and structures for advanced healthcare systems. Three-dimensional (3D) printing of these sustainable materials is applied in functional clinical settings including wound dressing, drug delivery systems, medical implants and tissue engineering. The present review highlights recent advancements in different types of biopolymers, such as proteins and polysaccharides, which are employed to develop different biomedical products by using extrusion, vat polymerization, laser and inkjet 3D printing techniques in addition to normal bioprinting and four-dimensional (4D) bioprinting techniques. This review also incorporates the influence of nanoparticles on the biological and mechanical performances of 3D-printed tissue scaffolds. This work also addresses current challenges as well as future developments of environmentally friendly polymeric materials manufactured through the AM techniques. Ideally, there is a need for more focused research on the adequate blending of these biodegradable biopolymers for achieving useful results in targeted biomedical areas. We envision that biopolymer-based 3D-printed composites have the potential to revolutionize the biomedical sector in the near future.

11.
Sensors (Basel) ; 23(3)2023 Feb 02.
Article En | MEDLINE | ID: mdl-36772677

Intelligent operation and maintenance technology for vessels can ensure the safety of the entire system, especially for the development of intelligent and unmanned marine technology. The material properties of metal abrasive particles in oil could demonstrate the wear areas of the marine mechanical system because different components consist of different materials. However, most sensors can only roughly separate metallic contaminants into ferromagnetic and non-ferromagnetic particles but cannot differentiate them in greater detail. A micro-three-coil sensor is designed in this paper; the device applies different excitation signals to two excitation coils to differentiate materials, based on the different effects of different material particles in the asymmetric magnetic field. Therefore, a particle's material can be judged by the shape of the induction electromotive force output signal from the induction coil, while the particle size can be judged by the amplitude of the signal. Experimental results show that the material differentiation of four different types of particles can be achieved, namely, of aluminum, iron, 304 stainless steel, and carbon steel. This newly designed sensor provides a new research prospect for the realization of an inductive detection method to distinguish non-ferrous metals and a reference for the subsequent detection of metal contaminants in oil and other liquids.

12.
Hematology ; 28(1): 2177979, 2023 Dec.
Article En | MEDLINE | ID: mdl-36794720

OBJECTIVE: Gain or amplification 1q21 (1q21+) is one of the most common recurrent cytogenetic abnormalities in multiple myeloma (MM). Our aim was to explore the presentation and outcomes of patients with MM harboring 1q21 + . METHODS: We retrospectively analyzed the clinical features and survival outcomes in 474 consecutive patients with MM receiving immunomodulatory drugs or proteasome inhibitor-based regimens as first-line therapies. RESULTS: 1q21 + was detected in 249 (52.5%) patients. Patients with 1q21 + had a higher proportion of subtypes of IgA, IgD, and λ-light chain than non-1q21 + . 1q21 + was associated with more advanced ISS stage and was more frequently accompanied by del(13q), elevated lactate dehydrogenase and lower levels of hemoglobin and platelets. Patients with 1q21 + had shorter PFS (21 months vs. 31 months, P = 0.001) and OS (43 months vs. 72 months, P < 0.001) than those without 1q21 + . Multivariate Cox regression analysis confirmed that 1q21 + was an independent prognostic factor for both PFS (HR 1.277, P = 0.031) and OS (HR 1.547, P = 0.003). Patients with 1q21 + del(13q) double-abnormality had shorter PFS (P < 0.001) and OS (P = 0.001) than those with no FISH abnormalities, and they also had shorter PFS (P = 0.018) and OS (P = 0.026) than those with del(13q) single abnormality. No significant difference in PFS (P = 0.525) or OS (P = 0.245) was found between patients with 1q21 + del(13q) double-abnormality and 1q21 + del(13q) multiple-abnormality. CONCLUSIONS: Patients with 1q21 + were more likely to have coexisting negative clinical features and del(13q). 1q21 + was an independent prognostic factor associated with poor outcomes. Concurrence with such unfavorable features may account for poor outcomes given 1q21 + .


Multiple Myeloma , Humans , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Retrospective Studies , Prognosis , Proteasome Inhibitors , Chromosome Aberrations
13.
Plant Cell ; 35(4): 1241-1258, 2023 03 29.
Article En | MEDLINE | ID: mdl-36648110

In Arabidopsis thaliana, female gametophyte (FG) development is accompanied by the formation and expansion of the large vacuole in the FG; this is essential for FG expansion, nuclear polar localization, and cell fate determination. Arabidopsis VACUOLELESS GAMETOPHYTES (VLG) facilitates vesicular fusion to form large vacuole in the FG, but the regulation of VLG remains largely unknown. Here, we found that gain-of-function mutation of BRASSINOSTEROID INSENSITIVE2 (BIN2) (bin2-1) increases VLG abundance to induce the vacuole formation at stage FG1, and leads to abortion of FG. Loss-of-function mutation of BIN2 and its homologs (bin2-3 bil1 bil2) reduced VLG abundance and mimicked vlg/VLG phenotypes. Knocking down VLG in bin2-1 decreased the ratio of aberrant vacuole formation at stage FG1, whereas FG1-specific overexpression of VLG mimicked the bin2-1 phenotype. VLG partially rescued the bin2-3 bil1 bil2 phenotype, demonstrating that VLG acts downstream of BIN2. Mutation of VLG residues that are phosphorylated by BIN2 altered VLG stability and a phosphorylation mimic of VLG causes similar defects as did bin2-1. Therefore, BIN2 may function by interacting with and phosphorylating VLG in the FG to enhance its stability and abundance, thus facilitating vacuole formation. Our findings provide mechanistic insight into how the BIN2-VLG module regulates the spatiotemporal formation of the large vacuole in FG development.


Arabidopsis Proteins , Arabidopsis , Arabidopsis/physiology , Arabidopsis Proteins/metabolism , Brassinosteroids/metabolism , Gene Expression Regulation, Plant/genetics , Germ Cells, Plant/metabolism , Ovule/genetics , Ovule/metabolism , Phosphorylation , Protein Kinases/metabolism , Signal Transduction/genetics , Vacuoles/metabolism
14.
J Am Chem Soc ; 145(5): 2860-2869, 2023 Feb 08.
Article En | MEDLINE | ID: mdl-36715560

Photoelectrochemical solar fuel generation at the semiconductor/liquid interface consists of multiple elementary steps, including charge separation, recombination, and catalytic reactions. While the overall incident light-to-current conversion efficiency (IPCE) can be readily measured, identifying the microscopic efficiency loss processes remains difficult. Here, we report simultaneous in situ transient photocurrent and transient reflectance spectroscopy (TRS) measurements of titanium dioxide-protected gallium phosphide photocathodes for water reduction in photoelectrochemical cells. Transient reflectance spectroscopy enables the direct probe of the separated charge carriers responsible for water reduction to follow their kinetics. Comparison with transient photocurrent measurement allows the direct probe of the initial charge separation quantum efficiency (ϕCS) and provides support for a transient photocurrent model that divides IPCE into the product of quantum efficiencies of light absorption (ϕabs), charge separation (ϕCS), and photoreduction (ϕred), i.e., IPCE = ϕabsϕCSϕred. Our study shows that there are two general key loss pathways: recombination within the bulk GaP that reduces ϕCS and interfacial recombination at the junction that decreases ϕred. Although both loss pathways can be reduced at a more negative applied bias, for GaP/TiO2, the initial charge separation loss is the key efficiency limiting factor. Our combined transient reflectance and photocurrent study provides a time-resolved view of microscopic steps involved in the overall light-to-current conversion process and provides detailed insights into the main loss pathways of the photoelectrochemical system.

15.
Eur J Haematol ; 110(3): 229-235, 2023 Mar.
Article En | MEDLINE | ID: mdl-36366975

OBJECTIVES: Recently, the Mayo Clinic introduced a new staging system (the Mayo Additive Staging System [MASS]) for patients with newly diagnosed multiple myeloma (NDMM) based on the number of high-risk (HR) abnormalities, including HR IgH translocations, 1q gain/amplification, chromosome 17 abnormalities, International Staging System (ISS)-III, and elevated lactate dehydrogenase. Patients with 0, 1, or ≥2 HR abnormalities were defined as stage I, II, or III, respectively. We aimed to validate the real-world prognostic value of the MASS. METHODS: We retrospectively analyzed the cytogenetic and laboratory results of 544 patients with NDMM at a single center. RESULTS: Ninety (16.5%) patients had no HR factors (MASS I), 193 (35.5%) had 1 HR factor (MASS II), and 261 (48%) had ≥2 HR factors (MASS III). The median progression-free survival (PFS) and overall survival (OS) times were 48, 28, and 20 months and 137, 73, and 39 months in the three groups, respectively (p < .001). In the subgroup analysis, patients had different OS outcomes based on the MASS when grouped by age, renal function, or therapeutic regimens. The MASS identified patients with the worst outcomes among those rated revised ISS II. CONCLUSION: The MASS system is a reliable risk stratification tool for patients with NDMM in real-world clinical practice.


Multiple Myeloma , Humans , Multiple Myeloma/diagnosis , Multiple Myeloma/genetics , Multiple Myeloma/therapy , Neoplasm Staging , Retrospective Studies , Prognosis , Chromosome Aberrations
16.
Hematol Oncol ; 41(1): 139-146, 2023 Feb.
Article En | MEDLINE | ID: mdl-36252280

The Second Revision of the International Staging System (R2-ISS) was recently introduced to improve risk stratification over that provided by the extensively applied standard revised International Staging System (R-ISS). In addition to the variables included in the R-ISS, the R2-ISS incorporates chromosome 1q gain/amplification and divides the patients into 4 groups with different survival outcomes, better stratifying patients within the R-ISS intermediate-risk. The new model was developed based on a great quantity of data from patients participating in uniform clinical trials and has not been validated in real-world clinical practice. Therefore, we retrospectively analyzed the prognostic value of the R2-ISS in 474 consecutive patients with multiple myeloma receiving immunomodulatory drugs or proteasome inhibitor-based regimens as their first-line treatment. According to the R2-ISS, 41 (8.6%), 76 (16%), 275 (58%), and 82 (17.3%) patients were identified as R2-ISS I, R2-ISS II, R2-ISS III, and R2-ISS IV, respectively. The median progression-free survival (PFS) was 48 (95% CI: 38-58), 35 (95% CI: 23-47), 24 (95% CI: 21-27), and 12 (95% CI: 7-17) months, and the estimated median overall survival (OS) was 110 (95% CI: 42-178), 88 (95% CI: 75-101), 50 (95% CI: 43-57), and 26 (95% CI: 19-33) months (p < 0.001) in the 4 groups, respectively. The R2-ISS could also classify groups with distinct survival among patients with renal impairment or classified as R-ISS II. Adjusted by age, sex, treatment approaches and transplantation status, the R2-ISS was an independent prognostic factor associated with OS with a hazard ratio of 7.055 (95% CI: 3.626-13.726) (p < 0.001) for R2-ISS IV versus R2-ISS I and 2.707 (95% CI: 1.436-5.103) (p = 0.002) for R2-ISS III versus R2-ISS I. In conclusion, our results suggest that the R2-ISS is a simple and robust risk stratification tool for patients with multiple myeloma treated with novel drugs and could be used in everyday clinical practice.


Multiple Myeloma , Humans , Multiple Myeloma/pathology , Proteasome Inhibitors/therapeutic use , Immunomodulating Agents , Neoplasm Staging , Retrospective Studies , Prognosis
17.
IEEE Trans Cybern ; 53(2): 1184-1194, 2023 Feb.
Article En | MEDLINE | ID: mdl-34606467

This article investigates the leader-follower formation learning control (FLC) problem for discrete-time strict-feedback multiagent systems (MASs). The objective is to acquire the experience knowledge from the stable leader-follower adaptive formation control process and improve the control performance by reusing the experiential knowledge. First, a two-layer control scheme is proposed to solve the leader-follower formation control problem. In the first layer, by combining adaptive distributed observers and constructed in -step predictors, the leader's future state is predicted by the followers in a distributed manner. In the second layer, the adaptive neural network (NN) controllers are constructed for the followers to ensure that all the followers track the predicted output of the leader. In the stable formation control process, the NN weights are verified to exponentially converge to their optimal values by developing an extended stability corollary of linear time-varying (LTV) system. Second, by constructing some specific "learning rules," the NN weights with convergent sequences are synthetically acquired and stored in the followers as experience knowledge. Then, the stored knowledge is reused to construct the FLC. The proposed FLC method not only solves the leader-follower formation problem but also improves the transient control performance. Finally, the validity of the presented FLC scheme is illustrated by simulations.

18.
Nanoscale Adv ; 4(3): 916-925, 2022 Feb 01.
Article En | MEDLINE | ID: mdl-36131835

Polymer composite materials have been proven to have numerous electrical related applications ranging from energy storage to sensing, and 3D printing is a promising technique to fabricate such materials with a high degree of freedom and low lead up time. Compared to the existing 3D printing technique for polymer materials, binder jet (BJ) printing offers unique advantages such as a fast production rate, room temperature printing of large volume objects, and the ability to print complex geometries without additional support materials. However, there is a serious lack of research in BJ printing of polymer materials. In this work we introduce a strategy to print poly(vinyl alcohol) composites with MXene-surfactant ink. By ejecting highly conductive MXene particles onto a PVOH matrix, the resulting sample achieved conductive behaviour in the order of mS m-1 with demonstrated potential for strain sensing and energy storage. This work demonstrates that BJ printing has the potential to directly fabricate polymer composite materials with different end applications.

19.
Adv Mater ; 34(45): e2206960, 2022 Nov.
Article En | MEDLINE | ID: mdl-36111463

Atomic-scale utilization and coordination structure of Pt electrocatalyst is extremely crucial to decrease loading mass and maximize activity for hydrogen evolution reactions (HERs) and oxygen reduction reactions (ORRs). A novel atomic-scale (Pt-Ox )-(Co-Oy ) nonbonding active structure is designed and constructed by anchoring Pt single atoms and Co atomic clusters on the defective carbon derived from oxygen-rich coal tar pitch (CTP). The Pt loading mass is extremely low and only 0.56 wt%. A new nonbonding interaction phenomenon between Pt-Ox and Co-Oy is found and confirmed based on X-ray absorption spectroscopy and density functional theory calculations. Based on the (Pt-Ox )-(Co-Oy ) nonbonding active structure, surface chemical field coupling with electrocatalysis for the HER and ORR is confirmed. It is found that the (Pt-Ox )-(Co-Oy ) nonbonding active structure exhibits high mass activities of 64.4 A cm-2 mgPt -1 (at an overpotential of 100 mV) and 7.2 A cm-2 mgPt -1 (at 0.8 V vs reversible hydrogen electrode) for the HER and ORR, respectively. The values are 6.5 and 11.6 times as much as those of commercial 20% Pt/C. The work provides innovative insight to design and understand efficient active sites of atomic-scale Pt on oxygen-rich CTP-derived carbon supports for electrocatalysis.

20.
ACS Appl Mater Interfaces ; 14(34): 39199-39210, 2022 Aug 31.
Article En | MEDLINE | ID: mdl-35976981

Silver nanowire (Ag NW)-based transparent electrodes (TEs) are promising alternatives to indium tin oxide (ITO) for next-generation flexible optoelectronic devices. Although many different constructs of Ag NW networks and post-treatment methods have been developed for TE applications, trade-offs between optical and electrical performance still remain. Herein, aided by electrohydrodynamic (EHD) printing, we present a cost-effective strategy to fabricate aligned Ag NW microgrids in a large area with excellent uniformity, resulting in superior optoelectronic properties. Guided by the percolation theory and simulation, we demonstrated that by confining aligned Ag NWs into a microgrid arrangement, the percolation threshold can be reduced significantly and adequate electrical conducting pathways can be achieved with an optimized combination of sheet resistance and optical transparency, which surpass conventional random Ag NW networks and random aligned Ag NW networks. The resulting TEs exhibit an ultrahigh transmittance of 99.1% at a sheet resistance of 91 Ω sq-1 with extremely low nanowire usage, an areal mass density of only 8.3 mg m-2, and uniform spatial distribution. Based on this TE design, we demonstrated transparent heaters exhibiting rapid thermal response and superior uniformity in heat generation. Using UV-curable epoxy, highly flexible Ag NW-embedded TEs were fabricated with superior mechanical stabilities and low surface roughness of 2.6 nm. Bendable organic light-emitting diodes (OLEDs) are directly fabricated on these flexible Ag NW electrodes, with higher current efficiency (27.7 cd A-1) than ITO devices (24.8 cd A-1).

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