bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Impact Study of the COVID-19 Pandemic on Routine Paediatric Immunisation in Nigeria: Recommendations to Strengthen Routine Immunization during a Pandemic
Authors: Amamilo Ifeyinwa , Iloduba Ndidi Nkemjika , Asunumeh Ikhenoba , Wakdok Sabastine 
Published: August 2023

The COVID-19 pandemic spread to Nigeria, resulting in a nationwide lockdown from 30th March 2020. Consequently, there was enormous impact on the health and socio-economic facets of life affecting individuals, families, and communities. A key component of primary health care that was affected was routine childhood immunisation which is one of the fundamental pillars of the Nigerian government’s child health care policy. The study aimed at evaluating the impact of the pandemic on routine immunization, as well as, make recommendations to strengthen routine immunization during a pandemic based on lessons learnt.
Primary data were collected using semi-structured questionnaires administered to 150 parents or caregivers across the childcare and wellness clinics of four selected secondary health facilities in the Federal Capital Territory (FCT) from January to June 2020 (January to March representing the pre-lockdown period while April to June, the lockdown period). Secondary data were collected from immunisation records of these facilities. The mean changes in the immunisation coverage of pre-lockdown period were compared with the lockdown period using student t-test. A p-value of < 0.05 was considered statistically significant.
There was a significant decline of 19.1% in the total number of immunizations given in the pre- and during the lockdown period [t=2.86, p=0.035]. This reduction was diverse across all districts and all vaccine antigens. The highest decline was seen for the 6 weeks’ vaccines (31.2%), followed by the 10 weeks (28.7%). Fear of contracting COVID was the commonest reason for missing vaccines (26.4%) followed by lack of transportation money (5.7%). For those that presented, the main reason for not getting vaccinated was that the vaccination centres were closed (55.6%). About 46.9% and 34.5% of the participants responded that they would prefer home-visits by the healthcare workers and hospital ‘drive-by’ for delivery of routine vaccination during a pandemic.
The COVID-19 pandemic significantly affected the routine immunisation in the FCT. Routine immunisation services should continue during pandemics while health promotion should be continued by the government, healthcare professionals and other stakeholders. Also pivotal is to ensure that healthcare workers have adequate training regarding infection, prevention and control measures, and vaccine logistics, while adhering to strict standard protocols. Appointment-based visits can be scheduled using phone calls, emails, and SMS to have less people in waiting areas. Drive-by and home-based services are acceptable alternatives for parents and caregivers in addition to fixed-site vaccination activities during a pandemic.
Tunable Interparticle Connectivity in Gold Nanosphere Assemblies for Efficient Photoacoustic Conversion
Authors: Kim Myeongsoo , Kim Jinhwan , VanderLaan Don , Kubelick Kelsey P. , Jhunjhunwala Anamik , Choe Ayoung , Emelianov Stanislav Y. 
Published: August 2023

AbstractManipulating matter at the nanometer scale to create desired plasmonic nanostructures holds great promise in the field of biomedical photoacoustic (PA) imaging. This study demonstrates a strategy for regulating PA signal generation from anisotropic nanosized assemblies of gold nanospheres (Au NSs) by adjusting the interparticle connectivity between neighboring Au NSs. The interparticle connectivity is controlled by modulating the diameter and interparticle spacing of Au NSs in the nanoassemblies. The results indicate that nanoassemblies with semi‐connectivity, i.e., assemblies with a finite interparticle spacing shorter than the theoretical limit of repulsion between nearby Au NSs, exhibit 3.4‐fold and 2.4‐fold higher PA signals compared to nanoassemblies with no connectivity and full connectivity, respectively. Furthermore, due to the reduced diffusion of Au atoms, the semi‐connectivity Au nanoassemblies demonstrates a high photodamage threshold and, therefore, excellent photostability at fluences above the current American National Standards Institute limits. The exceptional photostability of the semi‐connectivity nanoassemblies highlights their potential to surpass conventional plasmonic contrast agents for continuing PA imaging. Collectively, the findings indicate that semi‐connected nanostructures are a promising option for reliable, high‐contrast PA imaging applications over multiple imaging sessions due to their strong PA signals and enhanced photostability.
Gallium‐Based Liquid–Solid Biphasic Conductors for Soft Electronics
Authors: Reis Carneiro Manuel , Majidi Carmel , Tavakoli Mahmoud 
Published: August 2023

AbstractSoft and stretchable electronics have diverse applications in the fields of compliant bioelectronics, textile‐integrated wearables, novel forms of mechanical sensors, electronics skins, and soft robotics. In recent years, multiple material architectures have been proposed for highly deformable circuits that can undergo large tensile strains without losing electronic functionality. Among them, gallium‐based liquid metals benefit from fluidic deformability, high electrical conductivity, and self‐healing property. However, their deposition and patterning is challenging. Biphasic material architectures are recently proposed as a method to address this problem, by combining advantages of solid‐phase materials and composites, with liquid deformability and self‐healing of liquid phase conductors, thus moving toward scalable fabrication of reliable stretchable circuits. This article reviews recent biphasic conductor architectures that combine gallium‐based liquid‐phase conductors, with solid‐phase particles and polymers, and their application in fabrication of soft electronic systems. In particular, various material combinations for the solid and liquid phases in the biphasic conductor, as well as methods used to print and pattern biphasic conductive compounds, are discussed. Finally, some applications that benefit from biphasic architectures are reviewed.
Inhibited Grain Growth Through Phase Transition Modulation Enables Excellent Mechanical Properties in Oxide Ceramic Nanofibers up to 1700 °C
Authors: Xu Zhen , Liu Hualei , Wu Fan , Cheng Longdi , Yu Jianyong , Liu Yi‐Tao , Ding Bin 
Published: August 2023

AbstractOxide ceramics are widely used as thermal protection materials due to their excellent structural properties and earth abundance. However, in extremely high‐temperature environments (above 1500 °C), the explosive growth of grain size causes irreversible damage to the microstructure of oxide ceramics, thus exhibiting poor thermomechanical stability. This problem, which may lead to catastrophic accidents, remains a great challenge for oxide ceramic materials. Here, a novel strategy of phase transition modulation is proposed to control the grain growth at high temperatures in oxide ceramic nanofibers, realizing effective regulation of the crystalline forms as well as the size uniformity of primary grains, and thus suppressing the malignant growth of the grains. The resulting oxide ceramic nanofibers have excellent mechanical strength and flexibility, delivering an average tensile strength as high as 1.02 GPa after being exposed to 1700 °C for 30 min, and can withstand thousands of flexural cycles without obvious damage. This work may provide new insight into the development of advanced oxide ceramic materials that can serve in extremely high‐temperature environments with long‐term durability.
Dual Breaking of Molecular Orbitals and Spatial Symmetry in an Optically Controlled Ferroelectric
Authors: Liao Wei‐Qiang , Zeng Yu‐Ling , Tang Yuan‐Yuan , Xu Yu‐Qiu , Huang Xiao‐Yun , Yu Hang , Lv Hui‐Peng , Chen Xiao‐Gang , Xiong Ren‐Gen 
Published: August 2023

AbstractAs particles carry quantified energy, photon radiation enables orbital transitions of energy levels, leading to changes in the spin state of electrons. The resulting switchable structural bistability may bring a new paradigm for manipulating ferroelectric polarization. However, the studies on molecular orbital breaking in the ferroelectric field remain blank. Here, for the first time, a new mechanism of ferroelectrics—dual breaking of molecular orbitals and spatial symmetry, demonstrated in a photochromic organic crystal with light‐induced polarization switching, is formally proposed. By alternating the ultraviolet/visible light irradiation, the states of electron spin and the radial distribution p atomic orbitals experience a change, showing a reversible switch from “shoulder‐to‐shoulder” form to a “head‐to‐head” form. This reflects a reversible conversion between π and σ bonds, which induces and couples with the variation of spatial symmetry. The intersection of spatial symmetry breaking and molecular orbital breaking in ferroelectrics present in this work will be more conducive to data encryption and anticounterfeiting.
Sub‐Nanosecond Reconfiguration of Ferroelectric Domains in Bismuth Ferrite
Authors: Guzelturk Burak , Yang Tiannan , Liu Yu‐Chen , Wei Chia‐Chun , Orenstein Gal , Trigo Mariano , Zhou Tao , Diroll Benjamin T. , Holt Martin V. , Wen Haidan , Chen Long‐Qing , Yang Jan‐Chi , Lindenberg Aaron M. 
Published: August 2023

AbstractDomain switching is crucial for achieving desired functions in ferroic materials that are used in various applications. Fast control of domains at sub‐nanosecond timescales remains a challenge despite its potential for high‐speed operation in random‐access memories, photonic, and nanoelectronic devices. Here, ultrafast laser excitation is shown to transiently melt and reconfigure ferroelectric stripe domains in multiferroic bismuth ferrite on a timescale faster than 100 picoseconds. This dynamic behavior is visualized by picosecond‐ and nanometer‐resolved X‐ray diffraction and time‐resolved X‐ray diffuse scattering. The disordering of stripe domains is attributed to the screening of depolarization fields by photogenerated carriers resulting in the formation of charged domain walls, as supported by phase‐field simulations. Furthermore, the recovery of disordered domains exhibits subdiffusive growth on nanosecond timescales, with a non‐equilibrium domain velocity reaching up to 10 m s−1. These findings present a new approach to image and manipulate ferroelectric domains on sub‐nanosecond timescales, which can be further extended into other complex photoferroic systems to modulate their electronic, optical, and magnetic properties beyond gigahertz frequencies. This approach could pave the way for high‐speed ferroelectric data storage and computing, and, more broadly, defines new approaches for visualizing the non‐equilibrium dynamics of heterogeneous and disordered materials.
Broadband Electromagnetic Properties of Engineered Flexible Absorber Materials
Authors: Suriyasena Liyanage Luckshitha , Smith Connor S. , Pawlik Jacob , Evans Sarah , Stelson Angela , Long Christian , Orloff Nathan D. , Arnold David P. , Booth James C. 
Published: August 2023

AbstractFlexible and stretchable materials have attracted significant interest in wearable electronics and bioengineering fields. Recent developments also incorporate embedded microwave circuits and systems with engineered flexible materials that operate over a broad frequency range (≈1–100 GHz). Herein, a simple flip‐chip technique is used to evaluate frequency‐dependent electromagnetic properties of flexible materials and applied to evaluate engineered microwave absorbers based on self‐biased barium hexaferrite composites. On‐wafer error correction and de‐embedding techniques are applied to determine broadband electromagnetic properties of the material‐loaded transmission lines by placing the materials on top of coplanar waveguide transmission lines. Finite‐element simulations along with broadband measurements were employed to estimate the electromagnetic material properties. To demonstrate, flexible polydimethylsiloxane (PDMS) composites are fabricated with barium hexaferrite nanoparticles and complex permittivity and permeability of the composites are quantified under zero magnetic field bias up to 110 GHz. Frequency‐dependent composite permeability is fitted to models describing the ferromagnetic resonance of the self‐biased barium hexaferrite nanoparticles in polydimethylsiloxane, and constituent nanoparticle properties are estimated using the Maxwell–Garnett mixing model. This study paves the way to exploit a wide range of engineered materials in flexible, wearable, and biomedical electronics applications and presents a convenient methodology to extract important broadband electromagnetic properties of nanoparticles for customized electromagnetic applications.
Electrochemical Approach to Amide Bond Formation
Authors: Strekalova Sofia , Kononov Alexander , Morozov Vladimir , Babaeva Olga , Gavrilova Elena , Budnikova Yulia 
Published: August 2023

AbstractElectrochemical amidation of the C(sp2)−H and C(sp3)−H bonds of broad spectrum of arenes toward the direct synthesis of anilides and N‐benzylamides under mild conditions (room temperature, ambient pressure) in the absence of metal catalyst and external oxidizing agents using nitriles RCN (R=Me, Et) as amide source is described. This electrochemical approach features moderate to high yields, a broad scope of arenes with different functional groups and is amenable to gram scale synthesis. The key role of the hydroxyl radical as inductor generated during the oxidation of water and fixed by a spin trap in EPR experiment has been established.
3D Nanocomposite Thin Film Cathodes for Micro‐Batteries with Enhanced High‐Rate Electrochemical Performance over Planar Films
Authors: Lovett Adam J. , Daramalla Venkateswarlu , Nayak Debasis , Sayed Farheen N. , Mahadevegowda Amoghavarsha , Ducati Caterina , Spencer Ben F. , Dutton Siân E. , Grey Clare P. , MacManus‐Driscoll Judith L. 
Published: August 2023

AbstractHigh energy and high power density rechargeable micro‐batteries are a necessity for powering the next generation of flexible electronics, internet of things, and medical technology devices. In theory, significant improvements in the capacity, current and power densities of micro‐batteries would result if 3D architectures with enhanced interdigitated component interface areas and shortened ion diffusion path‐lengths were used. Further gains are achievable if the materials utilized have high crystalline quality and are preferentially oriented for fast lithium intercalation. In this work, this is achieved by creating epitaxial thin film cathodes comprised of nanopillars of LiMn2O4 (LMO) embedded in a supporting matrix of electronically conducting SrRuO3 (SRO). The first electrochemical study of such a 3D vertically aligned nanocomposite (VAN) that displays clear cathode redox signatures is provided, and demonstrates remarkable capacity retention under high‐rate regimes. The electrochemical performance is shown to be dependent on the nanopillar topography, namely the crystallographic orientation, nanopillar dimensions, and electrode/electrolyte interfacial surface area. This work offers a pathway to realizing 3D architectured micro‐batteries with high‐capacity retention under high‐rate conditions enabling fast charge capabilities.
Synergistic Dual Photoredox and Chiral Hydrogen Bonding Catalysis: Recent Advances
Authors: Selvakumar Sermadurai 
Published: August 2023

AbstractIn the last two decades, chiral hydrogen bonding catalysis has been enormously utilized to trigger several valuable synthetic transformations. Similarly, modern day radical chemistry has witnessed the potency of visible light photoredox catalysis to generate radicals via single electron transfer pathway. Recently, their cooperative effect has proved to be a key strategy to access many elegant transformations that are only feasible under the synergistic action of these two catalytic systems. This dual catalytic system demonstrates high efficiency for introducing molecular complexity in an enantioselective fashion. In this mini review, we have compiled the most recent development of this dual catalytic system that surfaced in the last three years with particular attention paid to the mechanistic details and its substrate scope. We hope that this mini review will provide readers with a brief overview of the advancement and application of photoredox catalysts and chiral hydrogen bond donors for synergistic dual catalytic reactions.
A Supramolecular Naphthalene Diimide Radical Anion with Efficient NIR‐II Photothermal Conversion for E. coli‐Responsive Photothermal Therapy
Authors: Hu Hao , Zhang Yang‐Yang , Ma He , Yang Yuchong , Mei Shan , Li Jun , Xu Jiang‐Fei , Zhang Xi 
Published: August 2023

AbstractWe report a supramolecular naphthalene diimide (NDI) radical anion with efficient NIR‐II photothermal conversion for E. coli‐responsive photothermal therapy. The supramolecular radical anion (NDI‐2CB[7])⋅−, which is obtained from the E. coli‐induced in situ reduction of NDI‐2CB[7] neutral complex, formed by the host–guest interaction between an NDI derivative and cucurbit[7]uril (CB[7]), exhibits unexpectedly strong NIR‐II absorption and remarkable photothermal conversion capacity in aqueous solution. The NIR‐II absorption is caused by the self‐assembly of NDI radical anions to form supramolecular dimer radicals in aqueous solution, which is supported by theoretically predicted spectra. The (NDI‐2CB[7])⋅− demonstrates excellent NIR‐II photothermal antimicrobial activity (>99 %). This work provides a new approach for constructing NIR‐II photothermal agents and non‐contact treatments for bacterial infections.
Promoting CO2 Electroreduction to Multi‐Carbon Products by Hydrophobicity‐Induced Electro‐Kinetic Retardation
Authors: Zhuansun Mengjiao , Liu Yue , Lu Ruihu , Zeng Fan , Xu Zhanyou , Wang Ying , Yang Yaoyue , Wang Ziyun , Zheng Gengfeng , Wang Yuhang 
Published: August 2023

AbstractAdvancing the performance of the Cu‐catalyzed electrochemical CO2 reduction reaction (CO2RR) is crucial for its practical applications. Still, the wettable pristine Cu surface often suffers from low exposure to CO2, reducing the Faradaic efficiencies (FEs) and current densities for multi‐carbon (C2+) products. Recent studies have proposed that increasing surface availability for CO2 by cation‐exchange ionomers can enhance the C2+ product formation rates. However, due to the rapid formation and consumption of *CO, such promotion in reaction kinetics can shorten the residence of *CO whose adsorption determines C2+ selectivity, and thus the resulting C2+ FEs remain low. Herein, we discover that the electro‐kinetic retardation caused by the strong hydrophobicity of quaternary ammonium group‐functionalized polynorbornene ionomers can greatly prolong the *CO residence on Cu. This unconventional electro‐kinetic effect is demonstrated by the increased Tafel slopes and the decreased sensitivity of *CO coverage change to potentials. As a result, the strongly hydrophobic Cu electrodes exhibit C2+ Faradaic efficiencies of ≈90 % at a partial current density of 223 mA cm−2, more than twice of bare or hydrophilic Cu surfaces.
Noncovalent Modification of Cycloparaphenylene by Catenane Formation Using an Active Metal Template Strategy**
Authors: Ishibashi Hisayasu , Rondelli Manuel , Shudo Hiroki , Maekawa Takehisa , Ito Hideto , Mizukami Kiichi , Kimizuka Nobuo , Yagi Akiko , Itami Kenichiro 
Published: August 2023

AbstractThe active metal template (AMT) strategy is a powerful tool for the formation of mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes, allowing the synthesis of a variety of MIMs, including π‐conjugated and multicomponent macrocycles. Cycloparaphenylene (CPP) is an emerging molecule characterized by its cyclic π‐conjugated structure and unique properties. Therefore, diverse modifications of CPPs are necessary for its wide application. However, most CPP modifications require early stage functionalization and the direct modification of CPPs is very limited. Herein, we report the synthesis of a catenane consisting of [9]CPP and a 2,2′‐bipyridine macrocycle as a new CPP analogue that contains a reliable synthetic scaffold enabling diverse and concise post‐modification. Following the AMT strategy, the [9]CPP‐bipyridine catenane was successfully synthesized through Ni‐mediated aryl‐aryl coupling. Catalytic C−H borylation/cross‐coupling and metal complexation of the bipyridine macrocycle moiety, an effective post‐functionalization method, were also demonstrated with the [9]CPP‐bipyridine catenane. Single‐crystal X‐ray structural analysis revealed that the [9]CPP‐bipyridine catenane forms a tridentated complex with an Ag ion inside the CPP ring. This interaction significantly enhances the phosphorescence lifetime through improved intermolecular interactions.
Combinatorial Screening of Water/Proton Permeation of Self‐Assembled Pillar[5]arene Artificial Water Channel Libraries
Authors: Andrei Iuliana‐Marilena , Strilets Dmytro , Fa Shixin , Baaden Marc , Ogoshi Tomoki , Barboiu Mihail 
Published: August 2023

AbstractArtificial water channels (AWCs) that selectively transport water and reject ions through bilayer membranes have potential to act as synthetic Aquaporins (AQPs). AWCs can have a similar osmotic permeability, better stability, with simpler manufacture on a larger‐scale and have higher functional density and surface permeability when inserted into the membrane. Here, we report the screening of combinatorial libraries of symmetrical and unsymmetrical rim‐functionalized PAs A–D that are able to transport ca. 107–108 water molecules/s/channel, which is within 1 order of magnitude of AQPs’ and show total ion and proton rejection. Among the four channels, C and D are 3–4 times more water permeable than A and B when inserted in bilayer membranes. The binary combinations of A–D with different molar ratios could be expressed as an independent (linear ABA), a recessive (inhibition AB, AC, DB, ACA), or a dominant (amplification, DBD) behavior of the water net permeation events.