bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen‐Vacancy‐Rich Piezoelectric BiO2−x Nanosheets for Augmented Piezocatalytic, Sonothermal, and Enzymatic Therapies
Authors: Yang Lu , Tian Boshi , Xie Ying , Dong Shuming , Yang Meiqi , Gai Shili , Lin Jun 
Published: April 2023

AbstractPiezocatalytic therapy is a new‐emerging reactive oxygen species (ROS)‐enabled therapeutic strategy that relies on built‐in electric field and energy‐band bending of piezoelectric materials activated by ultrasound (US) irradiation. Despite becoming a hot topic, material development and mechanism exploration are still underway. Herein, as‐synthesized oxygen‐vacancy‐rich BiO2−x nanosheets (NSs) demonstrate outstanding piezoelectric properties. Under US, a piezo‐potential of 0.25 V for BiO2−x NSs is sufficient to tilt the conduction band to be more negative than the redox potentials of O2/•O2−, •O2−/H2O2, and H2O2/•OH, which initiates a cascade reaction for ROS generation. Moreover, the BiO2−x NSs exhibit peroxidase and oxidase‐like activities to augment ROS production, especially in the H2O2‐overexpressed tumor microenvironment. Density functional theory calculations show that the generated oxygen vacancies in BiO2−x NSs are favorable for H2O2 adsorption and increasing the carrier density to produce ROS. Furthermore, the quick movement of electrons enables an excellent sonothermal effect, for example, rapid rise in temperature to nearly 65 °C upon US with low power (1.2 W cm−2) and short time (96 s). Therefore, this system realizes a multimode synergistic combination of piezocatalytic, enzymatic, and sonothermal therapies, providing a new direction for defect engineering‐optimized piezoelectric materials for tumor therapy.
Nano Surface‐Heterogeneities of Particles Modulate the Macroscopic Properties of Hydrogels
Authors: Rana Vijay K. , Karami Peyman , Nasrollahzadeh Naser , Pioletti Dominique P. 
Published: April 2023

AbstractNanoparticles, when incorporated into polymer matrices, can improve the intrinsic properties of composite materials. These materials possess fascinating properties and find widespread applications in bioengineering, medicine, aerospace, and electronics. However, the impact of nanoparticle surface heterostructures on composite systems is not fully understood. To bridge this gap, composite hydrogels (HRCs) are developed using rough‐surfaced raspberry‐like colloidal (RC) particles. It is hypothesized that the surface roughness of nanoparticles can significantly affect their adsorption, motion, and interfacial forces when interacting with polymeric networks, thereby influencing the macroscopic properties of HRCs. The properties of HRCs are compared with those of composite hydrogels containing smooth‐surfaced particles (HSCs) to isolate the effect of surface roughness. The results show that the nano‐surface heterogeneities of nanoparticles dictate the macroscopic properties of HRC hydrogels. It is found that HRCs exhibit much greater mechanical and adhesive properties compared to HSCs and control hydrogel without nanoparticles. As identified by the relaxation behavior, the enhanced frictional drag of interstitial fluid due to surface roughness, combined with the strong interaction of polymer network components dynamically linked by rough‐surfaced RC particles, is responsible for these improvements. These findings can guide the design and fabrication of new nanocomposites, including hydrogels, for various applications.
Alkyl Chain Length‐Dependent Amine‐Induced Crystallization for Efficient Interface Passivation of Perovskite Solar Cells
Authors: Zhao Pengjun , Subbiah Jegadesan , Zhang Bolong , Hutchison James A. , Ahluwalia Gagandeep , Mitchell Valerie , Ghiggino Kenneth P. , Jones David J. 
Published: April 2023

AbstractEfficient surface passivation of perovskite solar cells (PSC) using treatment with ammonium salts is demonstrated as an efficient method to enhance the device performance, owing to the affinity between the amine group and [PbI6]4− octahedron. However, due to their high solubility in polar solvents (DMF/DMSO), ammonium salts are more difficult to use in passivation of the interface between the electron transport layer and perovskite thin film in n‐i‐p structured PSCs. In this report, this work successfully links the amine group with a fullerene through a series of increasing carbon chain length, from two to twelve methylene units (FC‐X, X = 2, 6, 12), and then introduce the synthesized molecules as interface passivation layers into SnO2‐based planar n‐i‐p PSCs. Results show that the interface passivation effect is highly dependent on the side‐chain length, and the longer chain length amine‐functionalized fullerene is more beneficial for the device performance. A power conversion efficiency as high as 21.2% is achieved by using FC‐12. The surface energy, perovskite crystallite size and electron transfer capacity correlate with the linker chain length. This work develops an amine‐induced anchored crystallization of perovskite to unravel the mechanism of this passivation effect. As expected, enhanced device stability is also observed in the FC‐12 passivated PSCs.
Highly Efficient Electrocatalytic Hydrogen Production over Carbon Nanotubes Loaded with Platinum Nanoparticles Using Solution Processing
Authors: Metawea Osama R. M. , Nara Miyuki , Murakami Takeharu , Wada Satoshi , Fujii Katsushi , Ito Yoshihiro , Kawamoto Masuki 
Published: April 2023

AbstractProton exchange membrane (PEM) electrolyzers are used for hydrogen (H2) production by water electrolysis. The commercial cathodic electrocatalyst for this process is typically mechanically mixed platinum on carbon (Pt/C). However, aggregation of the platinum (Pt) makes high loading of the catalyst difficult. Therefore, a method for the homogeneous combination of Pt and carbon materials is required. Herein, the first example of a highly efficient single‐walled carbon nanotube (SWCNT) cathodic H2‐production electrocatalyst that is loaded with platinum nanoparticles (PtNPs) using a newly developed suspension method is reported. Combining SWCNTs lapped with a water‐soluble, thiol‐functionalized polymer with PtNPs in water yields a PtNP‐conjugated SWCNT suspension. The electrocatalyst exhibits a low overpotential of 47 mV at a current density of 10 mA cm−2 toward H2 evolution in 0.5 m sulfuric acid. A PEM electrolyzer fabricated using the optimally prepared electrocatalyst with the low loading of 15 µgPt cm−2 shows a high mass activity of 27 200 A gPt−1, which is 80 times that of Pt/C with a loading amount of 2.8 mgPt cm−2 (324 A gPt−1). In addition, the PEM electrolyzer produces H2 at a Faradaic efficiency of 97% and operates stably for 150 h at 100 mA cm−2.
Multiple Shapes Micro‐LEDs with Defect Free Sidewalls and Simple Liftoff and Transfer Using Selective Area Growth on Hexagonal Boron Nitride Template
Authors: Gujrati Rajat , Srivastava Ashutosh , Vuong Phuong , Ottapilakkal Vishnu , Sama Yves N. , Ngo Thi Huong , Moudakir Tarik , Patriarche Gilles , Gautier Simon , Voss Paul L. , Sundaram Suresh , Salvestrini Jean Paul , Ougazzaden Abdallah 
Published: April 2023

AbstractSeveral technological challenges have prevented GaN‐based micro‐LEDs from finding application in mass market displays, despite their unique properties such as very high brightness and the very fast response time of GaN‐based materials. The primary challenges are the cost and complexity of lift‐off and transfer of LEDs from sapphire substrates to suitable supports as well as the lowered performance of tiny micro‐LEDs caused by chemical etching that defines individual LEDs. Herein, this work reports demonstration of a complete process that solves these challenges with epitaxy and cleanroom technologies that are commercially available. The process begins with van der Waals epitaxy of 2D h‐BN on silica masks with square, triangular and hexagonal patterns on sapphire substrates which define the micro‐LED regions. Then selective area growth of MQW LED heterostructures, with ultra smooth crystalline sidewalls, down to ultra tiny size of 1.4 µm is performed. Because of the lack of vertical chemical bonds in the h‐BN layer, simple mechanical lift‐off and transfer is performed on an array of LEDs heterostructures down to size of 8 µm. Finally, transparent ITO p‐contacts are deposited on LEDs with uniform lift‐off, resulting in high brightness LEDs.
A Mobile E‐Nose Prototype for Online Breath Analysis
Authors: Chen Qiaofen , Guo Xufeng , Jiang Yuyue , Liu Xuemei , Xu Shiyuan , Huang Xuqing , Chen Yueling , Ye Xiaogang , Pan Aiwu , Dong Yalin , He Zhengfu , Wu Jianmin 
Published: April 2023

AbstractExhaled breath provides information of individual's holistic physiological condition, making non‐invasive exhaled breath testing a convenient and effective choice for personalized health management. This work proposes a mobile e‐nose prototype equipped with a miniaturized gas delivering unit, an advanced sensor array, a customized analog to digital conversion circuit board, an online data transmission, and machine learning algorithms that can effectively detect and analyze volatile compounds in exhaled breath, providing a systematic design strategy for non‐invasive disease diagnosis. The gas sensor array, as a core element, is composed of eight graphene‐based chemiresistive materials which are sensitive to trace gas analytes. In an online breath test study with 401 cases, patients with respiratory diseases can be distinguished from the healthy with an overall accuracy higher than 80%. In addition, classification of breath samples between patients with chronic obstructive pulmonary disease and the healthy higher than 85% is achieved. These results indicate the proposed portable e‐nose prototype holds great promise in personalized health state monitoring.
Synaptic Transistor Based on In‐Ga‐Zn‐O Channel and Trap Layers with Highly Linear Conductance Modulation for Neuromorphic Computing
Authors: Park Junhyeong , Jang Yuseong , Lee Jinkyu , An Soobin , Mok Jinsung , Lee Soo‐Yeon 
Published: April 2023

AbstractBrain‐inspired neuromorphic computing has drawn significant attraction as a promising technology beyond von Neumann architecture by using the parallel structure of synapses and neurons. Various artificial synapse configurations and materials have been proposed to emulate synaptic behaviors for human brain functions such as memorizing, learning, and visual processing. Especially, the memory type indium‐gallium‐zinc‐oxide (IGZO) synaptic transistor adopting a charge trapping layer (CTL) has the advantages of high stability and a low leakage current of the IGZO channel. However, the CTL material should be carefully selected and optimized to overcome the low de‐trapping efficiency, resulting from difficulty in inducing holes in the IGZO channel. In this paper, IGZO is adopted as a CTL and found out that making it degenerated is crucial to improving de‐trapping efficiency. The degenerate CTL, where electrons remain as free electrons, induces Fowler‐Nordheim tunneling by increasing the electric field across the tunneling layer. As a result, the synaptic transistor represents a high linearity of potentiation (αp: −0.03) and depression (αd: −0.47) with 64 conductance levels, which enables the spiking neural network simulation to achieve high accuracy of 98.08%. These experimental results indicate that the synapse transistor can be one of the promising candidates for neuromorphic applications.
Microscopic Quantum Transport Processes of Out‐of‐Plane Charge Flow in 2D Semiconductors Analyzed by a Fowler–Nordheim Tunneling Probe
Authors: Shin Dong Hoon , Lee Duk Hyun , Choi Sang‐Jun , Kim Seonyeong , Kim Hakseong , Watanabe Kenji , Taniguchi Takashi , Campbell Eleanor E. B. , Lee Sang Wook , Jung Suyong 
Published: April 2023

AbstractWeak interlayer couplings at 2D van der Waals (vdW) interfaces fundamentally distinguish out‐of‐plane charge flow, the information carrier in vdW‐assembled vertical electronic and optical devices, from the in‐plane band transport processes. Here, the out‐of‐plane charge transport behavior in 2D vdW semiconducting transition metal dichalcogenides (SCTMD) is reported. The measurements demonstrate that, in the high electric field regime, especially at low temperatures, either electron or hole carrier Fowler–Nordheim (FN) tunneling becomes the dominant quantum transport process in ultrathin SCTMDs, down to monolayers. For few‐layer SCTMDs, sequential layer‐by‐layer FN tunneling is observed to dominate the charge flow, thus serving as a material characterization probe for addressing the Fermi level positions and the layer numbers of the SCTMD films. Furthermore, it is shown that the physical confinement of the electron or hole carrier wave packets inside the sub‐nm thick semiconducting layers reduces the vertical quantum tunneling probability, leading to an enhanced effective mass of tunneling carriers.
Common population characteristics of direct‐seeded hybrid indica rice for high yield
Authors: Guo Changchun , Yuan Xiaojuan , Wen Yanfang , Yang Yonggang , Ma Yangming , Yan Fengjun , Li Bo , Wang Zhonglin , Xing Mengwen , Zhang Rongping , Yang Zhiyuan , Ma Jun , Sun Yongjian 
Published: April 2023

AbstractDirect seeding of rice has attracted attention because of its simplicity and rapidity compared with traditional cultivation methods. However, the geographical location of the rice region in Southwest China is complex, and the common characteristics of high yield of direct seeding hybrid indica rice and the law of nutrient absorption and accumulation are still unclear. This study results demonstrated that the mean yield of high‐yield varieties (HYV) in the two ecological points increased by 17.68%–19.98% and 17.37%–27.06%, respectively, compared with low‐yield varieties (LYV). The high tillering ability and effective tillering rate of HYV promoted a large leaf area index (LAI) and a strong photosynthetic capacity and stimulated the accumulation of aboveground biomass and nitrogen, phosphorus, and potassium nutrients in rice plants, which were finally transported and allocated to the grains to maintain high yields. Correlation analysis indicated that yield and its components were closely related to spatial population structure and nutrient accumulation and allocation. In particular, LAI at the full heading stage, net photosynthetic rate, aboveground biomass from jointing to maturity stage, and nitrogen, phosphorus, and potassium accumulation and distribution from jointing to full heading stage have the strongest correlation with yield and its components. Therefore, improving the effective tillering rate and LAI, as well as the accumulation and distribution of aboveground biomass, nitrogen, phosphorus, and potassium of rice plants from jointing to full heading stage, are the common laws for the formation of high yield of direct seeding hybrid rice in different ecological areas.
The impact of maritime shipping disruptions on US tree nut exports and inventories
Authors: Steinbach Sandro , Zhuang Xiting 
Published: April 2023

AbstractThis paper assesses the impact of the 2021/22 maritime shipping disruptions on US tree nut exports and domestic inventories. Using detailed trade data for almonds, pistachios, and walnuts and counterfactual empirical methods that account for treatment dynamics, we estimate the trade response to maritime shipping disruptions at the US port and commodity level. We find that tree nut shipments were 457 million pounds or $943 million below the counterfactual between May 2021 and July 2022. Almonds experienced the brunt of those trade losses, while pistachio and walnut exports recorded smaller losses and recovered faster. Our estimates imply that maritime shipping disruptions are a primary driver of surging tree nut inventories. Without the trade destruction caused by maritime shipping disruptions, the almond inventory could have been 38.7% lower and close to the long‐run average in the 2021/22 marketing year. [EconLit Citations: F14, Q17].
Closing the equity deficit: Sustainability justice in municipal climate action planning in Waterloo region
Authors: Dobai Jennifer , Riemer Manuel 
Published: April 2023

AbstractThere is growing recognition that often well‐intended climate action solutions perpetuate and exacerbate manifestations of colonialism and racism due to the lack of equity and justice considerations in designing and implementing these solutions. There is limited research exploring why the integration of these considerations are lacking in municipal climate action planning. This exploratory descriptive qualitative study explored how municipal actors perceive and understand equity and justice in municipal climate action planning as a step toward addressing this issue. Semistructured interviews were conducted with seven members of the core management group from ClimateAction Waterloo region, and a template analysis of the interview data resulted in six themes. Findings suggested that those involved in municipal climate action planning understand and perceive justice and equity considerations as important to their work, however, translating this understanding to practice is a challenge due to structural (governmental and societal) and capacity (limited time, funding, resources, and knowledge) barriers. By better understanding how key actors consider justice and equity, we identify shifting colonial mental models as a potential pathway for transformative change given the central role of these actors.
Association of primary lifetime occupational cognitive complexity and cognitive decline in a diverse cohort: Results from the KHANDLE study
Authors: Soh Yenee , Eng Chloe W. , Mayeda Elizabeth Rose , Whitmer Rachel A. , Lee Catherine , Peterson Rachel L. , Mungas Dan M. , Glymour M. Maria , Gilsanz Paola 
Published: April 2023

AbstractIntroductionHigher occupational complexity has been linked to favorable cognitive outcomes, but rarely examined in racially and ethnically diverse populations.MethodsIn a diverse cohort (n = 1536), linear mixed‐effects models estimated associations between main lifetime occupational complexity and domain‐specific cognitive decline (z‐standardized). Occupational complexity with data, people, and things were classified using the Dictionary of Occupational Titles.ResultsFor occupational complexity with data, highest tertile (vs. lowest) was associated with higher baseline executive function (β = 0.11; 95% confidence interval [CI] 0.00–0.22) and slower annual rate of decline (β = 0.03; 95% CI 0.01–0.06), and higher baseline semantic memory (β = 0.14; 95% CI 0.04–0.25). Highest tertile of occupational complexity with people was associated with higher baseline executive function (β = 0.29; 95% CI 0.18–0.40), verbal episodic memory (β = 0.12; 95% CI 0.00–0.24), and semantic memory (β = 0.23; 95% CI 0.12–0.34).DiscussionIn a diverse cohort, higher occupational complexity is associated with better cognition. Findings should be verified in larger cohorts.Highlight
Few studies have examined associations of occupational complexity with cognition in diverse populations.
Racial and ethnic minorities are disproportionately exposed to lower occupational complexity.
Occupational complexity with data and people are associated with better cognition.
Copper‐Catalyzed Dynamic Kinetic Asymmetric P−C Coupling of Secondary Phosphine Oxides and Aryl Iodides
Authors: Kang Jie , Ding Kang , Ren Si‐Mu , Su Bo 
Published: April 2023

AbstractTransition‐metal‐catalyzed enantioselective P−C cross‐coupling of secondary phosphine oxides (SPOs) is an attractive method for synthesizing P‐stereogenic phosphorus compounds, but the development of such a dynamic kinetic asymmetric process remains a considerable challenge. Here we report an unprecedented highly enantioselective dynamic kinetic intermolecular P−C coupling of SPOs and aryl iodides catalyzed by copper complexes ligated by a finely modified chiral 1,2‐diamine ligand. The reaction tolerates a wide range of SPOs and aryl iodides, affording P‐stereogenic tertiary phosphine oxides (TPOs) in high yields and with good enantioselectivity (average 89.2 % ee). The resulting enantioenriched TPOs were transformed into structurally diverse P‐chiral scaffolds, which are highly valuable as ligands and catalysts in asymmetric synthesis.
Aqueous Processable Two‐Dimensional Triazine Polymers with Superior Photocatalytic Properties
Authors: Sun Tian , Li Shuo , Zhang Lei , Xu Yuxi 
Published: April 2023

AbstractEfficient and scalable production of high‐quality and processable two‐dimensional (2D) polymers are highly desired but have not yet been reported. Herein, we demonstrate a convenient noncovalent functionalization strategy for producing highly uniform, aqueous processable and semiconducting 2D triazine polymers. Experimental and theoretical analysis reveal that the aromatic amphiphilic 1‐pyrenebutyrate can adsorb and intercalate into the interlayer of bulk crystalline covalent triazine framework (CTF) through noncovalent π‐π stacking interaction between the pyrene moiety and the porous basal plane of 2D triazine polymer layer, which greatly facilitate the exfoliation of CTF in water in large scale. The as‐prepared highly water‐dispersible single‐layer/few‐layer 2D triazine polymer nanosheets can be easily processed into ultralight aerogels with a density of 5–15 mg cm−3, which can be further shaped into mechanically strong films upon simple compression. This noncovalent functionalization not only improve the dispersibility and processability of 2D triazine polymer, but also optimize its band structure and promote the photogenerated carrier separation via an interesting surface molecule doping effect, thus resulting in a remarkable photocatalytic hydrogen evolution rate of 1249 μmol h−1 (24980 μmol g−1 h−1) and apparent quantum efficiency up to 27.2 % at 420 nm for the 2D triazine polymer, outperforming most metal‐free photocatalysts ever reported.
In‐situ formation of macromolecule P/N/Si flame retardant for epoxy resin with low smoke toxicity and excellent flame‐retardancy
Authors: Liu Huaiyin , Zheng Penglun , Li Junwei , Sun Jichang , Wang Rui , Zhao Haihan , Wu Jing , Zheng Yun , Liu Quanyi 
Published: April 2023

AbstractEpoxy resins (EP) have great chemical and physical properties, but their poor flame retardant properties have prevented their widespread use. To improve the flame retardancy properties of EP, an active P/N/Si flame retardant (KDC) containing a double bond was successfully synthesized in this work by using a typical aldehyde amine condensation reaction. This flame retardant not only can form a large molecule flame retardant in situ by double bond reaction and increase the tightness with EP matrix, but also has the advantage of P/N/Si three elements synergistic flame retardant, and at the same time play the flame retardant performance of each element, can achieve excellent flame retardant performance and low smoke and toxicity with low addition amount. Subsequently, the performance of the flame retardants was tested. When 7 wt% of KDC was added, the pHRR and TSR of the EP composites were reduced by 51.7% and 29.8%, respectively. More importantly, the addition of KDC inhibited the release of toxic fuels and smoke from EP, where the TSP values of EP/3‐KDC were 18.14% below those of neat EP and increased the residual amount of charcoal, while the inhibition of CO and CO2 release was particularly pronounced with the presence of KDC.