bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion Behavior of Candidate Materials in Molten LiCl-KCl Salt Under Argon Atmosphere
Authors: Shankar A. Ravi , Thyagarajan K. , Mudali U. Kamachi
Published: February 2013

Pyrochemical reprocessing involves the use of molten LiCl-KCl (lithium chloride-potassium chloride) eutectic salt at 773 K for the recovery of uranium and plutonium from spent metallic fuel of fast breeder reactors. The materials selected for such corrosive environments should withstand high temperatures and at the same time offer good corrosion resistance. The present work discusses the corrosion behavior of candidate materials like 2.25Cr-1Mo steel (UNS K21590), 9Cr-1 Mo steel (UNS K90941), Ni-based alloy 600 (UNS N06600), Ni-based alloy 625 (UNS N06625), and Ni-based alloy 690 (UNS N06690) in molten LiCl-KCl eutectic salt at 873 K for various durations under ultrahigh-purity argon atmosphere. Corrosion behavior of partially stabilized zirconia (PSZ) coating on candidate materials also was evaluated. Weight-loss results indicated that the corrosion resistance of the materials increased in the following order: 2.25Cr-1Mo > 9Cr-1 Mo > Ni-based alloys > PSZ coating. PSZ-coated specimens showed better corrosion resistance in molten LiCl-KCl salt when compared with uncoated specimens; however, accidental ingression of oxygen and moisture could result in premature spallation of the coating. Scanning electron microscopy (SEM) examination and grazing incidence x-ray diffraction (GIXRD) analysis of exposed Cr-Mo steels and Ni-based alloys exhibited dealloyed surfaces and corrosion product regions rich in Cr, indicating preferential leaching of Cr. The paper highlights the results of the present investigation.
Characterization of organic aerosol produced during pulverized coal combustion in a drop tube furnace
Authors: Wang X. , Williams B. J. , Wang X. , Tang Y. , Huang Y. , Kong L. , Yang X. , Biswas P.
Published: February 2013

Abstract. Controlled bench scale pulverized coal combustion studies were performed that demonstrate that inorganic particles play a critical role as carrier of organic species. Two commonly-used aerosol mass spectrometry techniques have been applied to characterize fine particle formation during coal combustion. It was found that the organic species in coal combustion aerosols have similar mass spectra as those from biomass combustion. Ambient measurements in Shanghai, China confirm the presence of these species in approximately 36~42% of the sampled particles. With the absence of major biomass sources in the Shanghai area, it is suggested that coal combustion may be the main source of these particles. This work indicates there is a significant potential for incorrect apportionment of coal combustion particles to biomass burning sources using widely adopted mass spectrometry techniques.
Trace metal distribution in pristine permafrost-affected soils of the Lena River Delta and its Hinterland, Northern Siberia, Russia
Authors: Antcibor I. , Zubrzycki S. , Eschenbach A. , Kutzbach L. , Bol'shiyanov D. , Pfeiffer E.-M.
Published: February 2013

Abstract. Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N–69.5° N) representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe), arsenic (As), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co) and mercury (Hg) in different soil types developed in different geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex) in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island) showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA) revealed that soil oxides play a significant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were similar to background levels reported for other pristine arctic areas and did not exceed mean global background concentrations examined for the continental crust as well as for the world's soils.
Comment on "Polynomial cointegration tests of anthropogenic impact on global warming" by Beenstock et al. (2012) – Some fallacies in econometric modelling of climate change
Authors: Hendry D. F. , Pretis F.
Published: February 2013

Abstract. We demonstrate major flaws in the statistical analysis of Beenstock et al. (2012), discrediting their initial claims as to the different degrees of integrability of CO2 and temperature.
The New Christian Rhetoric of Origen
Authors: Duncan Michael
Published: February 2013

This article explores Contra Celsum as the extant text most representative of the homiletician, philosopher, and scholar Origen's thoughts on rhetoric, which have been underexplored. The Contra Celsum addresses several practical problems facing third-century Christianity, among them the conversion of mixed audiences, the usefulness of pagan rhetoric, and the protection and delivery of the newly canonized New Testament and its divine proofs. Origen's conception of a separate Christian rhetoric that attempts to solve these problems predates and possibly informs the union of Christian and pagan rhetoric in Augustine's De doctrina christiana.
Hope in Multiple Sclerosis: A Nursing Perspective
Authors: Morgante Linda
Published: February 2013

Feelings of hopelessness are common in patients with multiple sclerosis (MS), which poses a significant threat to an individual's independence and feelings of competence. Because hope has been shown to play an important role in health and coping during chronic illness, it is critical for the MS provider to understand the elements of hope and recognize when the person with MS is struggling with feelings of hopelessness. The MS nurse is the pivotal player in ensuring that the individual with MS maintains a sense of hope throughout the illness. In addition to providing education, counseling and referrals, the nurse can help the MS patient focus on feelings and ideas, recognize personal reasons for living, and establish both short-term and long-term goals.
Longitudinal Assessment of Health-Related Quality of Life (HRQL) of Patients with Multiple Sclerosis
Authors: Hopman Wilma M. , Coo Helen , Brunet Donald G. , Edgar Catherine M. , Singer Michael A.
Published: February 2013

Over the past decade, health-related quality of life (HRQL) has become an important tool for assessing health status. To evaluate factors that could influence changes in HRQL over time, we surveyed multiple sclerosis (MS) patients who had completed the Medical Outcomes Trust 36-item Health Survey (SF-36) as part of a cross-sectional analysis of HRQL in 1994. Of the 100 subjects in the original study, 45 provided follow-up surveys in 1998.

The 1998 Expanded Disability Status Scale (EDSS) score was obtained from patient records. Disease severity (mild, moderate, or severe) was derived from the EDSS score. Differences from baseline scores for the eight domains and the two summary scales of the SF-36 were calculated. Patients were stratified by sex, baseline disease severity, and change in disease severity, to determine if any of these factors were associated with changes in HRQL.

A significant decline in health status was observed in the physical functioning, role physical, general health, and social functioning domains and on the physical component summary of the SF-36. In contrast, slightly over half the group showed an improvement in the mental health domain. Baseline disease severity was not significantly associated with changes in HRQL. However, change in disease severity was associated with change in the role emotional domain. Also, men showed significantly more deterioration than women in the role emotional domain. There were several meaningful changes in HRQL over time in this small sample. Additional studies are warranted to investigate associated factors. This may lead to a better understanding of HRQL for MS patients, and ultimately to improved patient care.
Incidental Complication From a Left Atrial Appendage Device
Authors: Garg Rimmy , Mungee Sudhir , Baumann Rebecca
Published: July 2024

This case report describes a diagnosis of extracardiac mural thrombus and pulmonary emboli resulting from a left atrial appendage device in a patient with atrial fibrillation.
National and State Estimates of SELECT Trial Eligibility and Its Public Health Impact in the US
Authors: Erhabor John , Khorsandi Michael , Blaha Michael J.
Published: July 2024

This cross-sectional study of US adults examines the geographical distribution of individuals eligible to participate in the Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity (SELECT) trial to estimate potential cardiovascular health impacts of implementing the trial findings at state and national levels.
The super‐recogniser advantage extends to the detection of hyper‐realistic face masks
Authors: Robertson David J. , Davis Josh P. , Sanders Jet G. , Towler Alice
Published: July 2024

Hyper‐realistic silicone masks provide a viable route to identity fraud. Over the last decade, more than 40 known criminal acts have been committed by perpetrators using this type of disguise. With the increasing availability and bespoke sophistication of these masks, research must now focus on ways to enhance their detection. In this study, we investigate whether super‐recognisers (SRs), people who excel at identity recognition, are more likely to detect this type of fraud, in comparison to typical‐recogniser controls. Across three tasks, we examined mask detection rates in the absence of a pre‐task prompt (covert task), and again after making participants aware of their use in criminal settings (explicit task). Finally, participants were asked to indicate which aspects of the masks could support their detection (regions of interest task). The findings show an SR advantage for the detection of hyper‐realistic masks across the covert and explicit mask detection tasks. In addition, the eye, mouth, and nose regions appear to be particularly indicative of the presence of a mask. The lack of natural skin texture, proportional features, expressiveness, and asymmetry are also salient cues. The theoretical and applied implications of these findings are discussed.
Does presentation size of instructional materials influence the split‐attention effect?
Authors: Zhang Shirong , de Koning Bjorn B. , Paas Fred
Published: July 2024

The split‐attention effect posits that learning outcomes are negatively impacted when interrelated text and graphics are spatially segregated rather than cohesively integrated. This study explored how the instructional material's presentation size influences the manifestation of the split‐attention effect. Based on cognitive load theory and perceptual load theory, we hypothesized that elevated information density in a compact presentation format would attenuate the advantage of integrated text and graphics, thereby diminishing the salience of the split‐attention effect relative to a more expansive presentation size. University students (n = 146) studied a split‐attention format or integrated format in either large or small presentation size. Results on retention and comprehension tests and extraneous cognitive load ratings revealed no effects of instructional format, presentation size or their interaction. The present results call for a more nuanced understanding of the split‐attention effect and suggest additional research to explore its cognitive foundations.
Time‐Space‐Coding Radiation‐Stealth Metasurface with Amplitude‐Phase Co‐Modulation
Authors: Mu Yajie , Xia Dexiao , Han Jiaqi , Ma Xiangjin , Wang Xin , Liu Haixia , Li Long
Published: July 2024

The integrated design of radiation and stealth holds significant importance for radar communication and camouflage. Currently, radar systems primarily rely on radomes for off‐band stealth. However, achieving in‐band stealth by radomes and absorbing materials is challenging. Even more challenging is the dynamic control of both in‐band radiation and stealth. Therefore, a novel space‐time‐coding metasurface is proposed for radiation and stealth modes regulation. By adjusting the two PIN diodes loaded on the meta‐atom, switching between radiation and scattering modes can be achieved. A 1‐bit reflection phase can be achieved in the scattering mode. The stealth is achieved by controlling the scattering properties of the metasurface. In the radiation mode, 2‐bit phase modulation is achieved by separately controlling the PIN diodes on the meta‐atom and the 3 dB coupler. Additionally, by varying the size of the meta‐atom in the y‐polarization direction, a 1‐bit reflection phase also can be achieved. To validate the proposed radiation‐stealth metasurface characteristics, a 12 × 12 prototype is fabricated. This prototype demonstrates important functionalities, including dual‐mode radiation, amplitude‐phase co‐modulation space‐time‐coding stealth, and space‐coding stealth.
Boronic Acid‐Rich Lanthanide Metal‐Organic Frameworks Enable Deep Proteomics with Ultratrace Biological Samples
Authors: Zhang Shuang , Ghalandari Behafarid , Chen Youming , Wang Qingwen , Liu Kun , Sun Xinyi , Ding Xinwen , Song Sunfengda , Jiang Lai , Ding Xianting
Published: July 2024

Label‐free proteomics is widely used to identify disease mechanism and potential therapeutic targets. However, deep proteomics with ultratrace clinical specimen remains a major technical challenge due to extensive contact loss during complex sample pretreatment. Here, a hybrid of four boronic acid‐rich lanthanide metal‐organic frameworks (MOFs) with high protein affinity is introduced to capture proteins in ultratrace samples jointly by nitrogen‐boronate complexation, cation‐π and ionic interactions. A MOFs Aided Sample Preparation (MASP) workflow that shrinks sample volume and integrates lysis, protein capture, protein digestion and peptide collection steps into a single PCR tube to minimize sample loss caused by non‐specific absorption, is proposed further. MASP is validated to quantify ≈1800 proteins in 10 HEK‐293T cells. MASP is applied to profile cerebrospinal fluid (CSF) proteome from cerebral stroke and brain damaged patients, and identified ≈3700 proteins in 1 µL CSF. MASP is further demonstrated to detect ≈9600 proteins in as few as 50 µg mouse brain tissues. MASP thus enables deep, scalable, and reproducible proteome on precious clinical samples with low abundant proteins.
Unraveling the Role of the Stoichiometry of Atomic Layer Deposited Nickel Cobalt Oxides on the Oxygen Evolution Reaction
Authors: van Limpt Renée T. M. , Lao Mengmeng , Tsampas Mihalis N. , Creatore Mariadriana
Published: July 2024

Nickel cobalt oxides (NCOs) are promising, non‐precious oxygen evolution reaction (OER) electrocatalysts. However, the stoichiometry‐dependent electrochemical behavior makes it crucial to understand the structure‐OER relationship. In this work, NCO thin film model systems are prepared using atomic layer deposition. In‐depth film characterization shows the phase transition from Ni‐rich rock‐salt films to Co‐rich spinel films. Electrochemical analysis in 1 m KOH reveals a synergistic effect between Co and Ni with optimal performance for the 30 at.% Co film after 500 CV cycles. Electrochemical activation correlates with film composition, specifically increasing activation is observed for more Ni‐rich films as its bulk transitions to the active (oxy)hydroxide phase. In parallel to this transition, the electrochemical surface area (ECSA) increases up to a factor 8. Using an original approach, the changes in ECSA are decoupled from intrinsic OER activity, leading to the conclusion that 70 at.% Co spinel phase NCO films are intrinsically the most active. The studies point to a chemical composition dependent OER mechanism: Co‐rich spinel films show instantly high activities, while the more sustainable Ni‐rich rock‐salt films require extended activation to increase the ECSA and OER performance. The results highlight the added value of working with model systems to disclose structure‐performance mechanisms.
Chiral‐induced highly efficient NIR–photothermal conversion of perylene diimide@silica nanocapsules for photothermal therapy
Authors: Zhao Yue , An Fuhao , Wu Jichao , Li Haining , Wang Xueyu , Jiao Lanya , Kong Ying , Zhu Jinghan , Sun Xun , Li Xu , Wang Miao , Zhang Yu , Sun Xuan
Published: July 2024

Photothermal agents (PTAs) with ultra‐high photothermal conversion efficiency (PCE) activated upon near‐infrared (NIR) laser irradiation can heat up and destroy tumor cells under low‐intensity laser excitation to allow safe and efficient tumor therapy. Herein, an organic PTA with an outstanding PCE of 89.6% is developed from rationally designed perylene diimide (PDI) with electron‐donating cyclohexylamine moiety at the bay‐positions of its skeleton and chiral phenethylamine (PEA) moiety at its N terminals, termed here PEAPDI. The strong intermolecular interaction between the PDI skeletons induced by PEA together with the intramolecular charge transfer from cyclohexylamine to PDI skeleton severely quenches the fluorescence emission from PEAPDI and significantly enhances its NIR absorption, resulting in super NIR–photothermal conversion. PEAPDI molecules are subsequently encapsulated within silica nanocapsules (SNCs), creating PEAPDI@SNC. Characterized by its small hydrodynamic diameter, monodispersity, high PDI encapsulation efficiency, colloidal stability, and biocompatibility, PEAPDI@SNC exhibits prolonged blood circulation and enhanced permeability and retention effect, enabling targeted accumulation at the tumor site. An in vivo study using a 4T1 tumor–bearing mice model illustrates the agent's potent tumor ablation capability without side effects at low dosage under NIR laser irradiation (808 nm). The findings demonstrate PEAPDI@SNC's significant potential as a PTA for tumor treatment.
Hardware Implementation of Next Generation Reservoir Computing with RRAM‐Based Hybrid Digital‐Analog System
Authors: Dong Danian , Zhang Woyu , Xie Yuanlu , Yue Jinshan , Ren Kuan , Huang Hongjian , Zheng Xu , Sun Wen Xuan , Lai Jin Ru , Fan Shaoyang , Wang Hongzhou , Yu Zhaoan , Yao Zhihong , Xu Xiaoxin , Shang Dashan , Liu Ming
Published: July 2024

Reservoir computing (RC) possesses a simple architecture and high energy efficiency for time‐series data analysis through machine learning algorithms. To date, RC has evolved into several innovative variants. The next generation reservoir computing (NGRC) variant, founded on nonlinear vector autoregression (NVAR) distinguishes itself due to its fewer hyperparameters and independence from physical random connection matrices, while yielding comparable results. However, NGRC networks struggle with massive Kronecker product calculations and matrix‐vector multiplications within the read out layer, leading to substantial efficiency challenges for traditional von Neumann architectures. In this work, a hybrid digital‐analog hardware system tailored for NGRC is developed. The digital part is a Kronecker product calculation unit with data filtering, which realizes transformation of nonlinear vector of the input linear vector. For matrix‐vector multiplication, a computing‐in‐memory architecture based on resistive random access memory array offers an energy‐efficient hardware solution, which markedly reduces data transfer and greatly improve computational parallelism and energy efficiency. The predictive capabilities of this hybrid NGRC system are validated through the Lorenz63 model, achieving a normalized root mean square error (NRMSE) of 0.00098 and an energy efficiency of 19.42TOPS W−1.
Vision‐Based Online Key Point Estimation of Deformable Robots
Authors: Zheng Hehui , Pinzello Sebastian , Cangan Barnabas Gavin , Buchner Thomas J. K. , Katzschmann Robert K.
Published: July 2024

The precise control of soft and continuum robots requires knowledge of their shape, which has, in contrast to classical rigid robots, infinite degrees of freedom. To partially reconstruct the shape, proprioceptive techniques use built‐in sensors, resulting in inaccurate results and increased fabrication complexity. Exteroceptive methods so far rely on expensive tracking systems with reflective markers placed on all components, which are infeasible for deformable robots interacting with the environment due to marker occlusion and damage. Here, a regression approach is presented for three‐dimensional key point estimation using a convolutional neural network. The proposed approach uses data‐driven supervised learning and is capable of online markerless estimation during inference. Two images of a robotic system are captured simultaneously at 25 Hz from different perspectives and fed to the network, which returns for each pair the parameterized key point or piecewise constant curvature shape representations. The proposed approach outperforms markerless state‐of‐the‐art methods by a maximum of 4.5% in estimation accuracy while being more robust and requiring no prior knowledge of the shape. Online evaluations on two types of soft robotic arms and a soft robotic fish demonstrate the method's accuracy and versatility on highly deformable systems.
A Wireless Drive and Control Method for Robots: Multifrequency Microwaves
Authors: Li Yongze , Wu Jianyu , Zhao Lijun , Xing Zhiguang , Zhao Jianwen
Published: July 2024

Microwave (MW)‐driven strategies could potentially offer transmissivity through obstacles, selective energization, wave‐focusing, and nonmechanical steering via phased‐array technologies, which have unique application prospects in confined environments. Implementing multidegree of freedom (MDOF) control is the key to developing motion strategies for advanced MW‐driven robots. However, the use of MWs for MDOF control of robots has so far remained a challenge. This article first presents examples of wireless driving and controlling millimeter‐scale peristaltic pipeline robots (diameter, 4 mm; length, 30 mm; weight, 0.39 g) utilizing multifrequency MWs in complex nonmetal channel environments. Herein, shape memory alloy springs combined with passive wires, whose length depends on the frequencies of MWs, are adopted to form selectively controlled robot components, and silicon rubber replica technology is utilized to achieve miniaturization of the robot. The monopole antenna model is developed for the actuator, and its structure is refined using antenna theory. This allows the successfully achievement of MDOF control of the robot at several MW frequencies (2.4, 4, and 5.9 GHz). Powered by MWs from outside the pipe, the pipeline robot achieves horizontal, vertical, and curved motions in a pipe with a diameter of 5 mm.
Current Developments in Michael Addition Reaction using Heterocycles as Convenient Michael Donors
Authors: Samanta Barsha , Shankar Panda Bhabani , Mohapatra Seetaram , Nayak Sabita
Published: July 2024

The Michael addition reaction, a cornerstone of contemporary organic synthesis, has witnessed a resurgence of interest owing to its ability to forge intricate carbon‐carbon and carbon‐heteroatom bonds. In the past few years, heterocyclic compounds have been rigorously used as Michael donors, owing to their architectural diversity and distinct reactivity with or without the presence of base/transition metals/organocatalysts. This review encapsulates the latest breakthroughs in chemistry involving Michael addition reaction using heterocyclic compounds as Michael donors. It delivers a comprehensive update on developments in Michael addition reaction triggered by potent heterocycles since 2017, highlighting novel and innovative methodologies, with strategic insights.
One‐Step Construction of 9,10‐Diarylphenanthrenes Using Solid Calcium Carbide as an Alternative of Gaseous Acetylene
Authors: Liu Zhenrong , Wang Zhiqiang , Li Zheng
Published: July 2024

A convenient method for the construction of 9,10‐diarylphenanthrenes through one‐pot multicomponent reactions of iodoarenes, o‐bromobenzoic acids, and calcium carbide is described. A series of target compounds are efficiently synthesized via Csp2−H activation and the simultaneous construction of five C−C bonds. The salient features of this method are the use of inexpensive and easy‐to‐handle solid alkyne source as an alternative of flammable and explosive gaseous acetylene. Meanwhile the use of commercially available substrates, wide functional tolerance, and simple workup procedure are also advantage of this protocol. In addition, the corresponding products can also be synthesized on gram scale.
Elektrochemische Gerüst‐Editierung von Indolen durch Stickstoffatom‐Insertion mit nachhaltiger Sauerstoff‐Reduktionsreaktion
Authors: Zhang Bo‐Sheng , Homölle Simon L. , Bauch Tristan , Oliveira João C. A. , Warratz Svenja , Yuan Binbin , Gou Xue‐Ya , Ackermann Lutz
Published: July 2024

Molekulares Editieren hat in letzter Zeit stark an Bedeutung gewonnen und sich als einzigartiges Werkzeug für Late‐Stage Diversifizierungen erwiesen. Bislang waren für die Indol‐Editierung meist überstöchiometrische Mengen an teuren hochvalenten Iod(III)‐Reagenzien erforderlich. Im Gegensatz dazu zeigen wir hier, dass Elektrizität nachhaltige Stickstoffatom‐Insertionsreaktionen ermöglicht, um bio‐relevante Chinazolin‐Gerüste ohne stöchiometrische chemische Redox‐Abfallprodukte zu erhalten. Die Übergangsmetall freie Elektro‐Editierung wurde durch die Sauerstoff‐Reduktionsreaktion (ORR) ermöglicht und erwies sich in großem Maßstab als robust, wobei eine Vielzahl wertvoller funktioneller Gruppen toleriert wurden.
Molecular Engineering Regulation Achieving Out‐of‐Plane Polarization in Rare‐Earth Hybrid Double Perovskites for Ferroelectrics and Circularly Polarized Luminescence
Authors: Wang Na , Xu Ze‐Jiang , Ni Hao‐Fei , Luo Wang , Li Hua‐Kai , Ren Mei‐Ling , Shi Chao , Ye Heng‐Yun , Fu Xiao‐Bin , Zhang Yi , Miao Le‐Ping
Published: July 2024

Out‐of‐plane polarization is a highly desired property of two‐dimensional (2D) ferroelectrics for application in vertical sandwich‐type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out‐of‐plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S‐3‐hydroxylquinuclidinium), we designed a molecular strategy of F‐substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S‐3‐fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out‐of‐plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F‐substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F‐substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro‐nano optoelectronic devices.
A Simple and Sequential Strategy for the Introduction of Complexity and Hierarchy in Hydrogen‐Bonded Organic Framework (HOF) Crystals for Environmental Applications
Authors: Halliwell Christopher A. , Jolley Kenny , Yendall Keith , Elsegood Mark R. J. , Parkinson Gary N. , Fernandez Antonio
Published: July 2024

Hydrogen‐bonded organic frameworks (HOFs) are a new class of crystalline porous organic molecular materials (POMMs) with great potential for a diverse range of applications. HOFs face common challenges to POMMs, and in general to purely organic crystals, that is, the difficulty of integrating complexity in crystals. Herein, we propose a simple and sequential strategy for the formation of HOFs with hierarchical superstructures. The strategy is based on controlling the assembly conditions, avoiding the use of any surface functionalization or template, which allows to obtain hierarchical crystalline porous superstructures in an easy manner. As proof of concept, we obtained the first example of core–shell (HOF‐on‐HOF) crystals and HOFs with hierarchical superstructures having superhydrophobicity and trapping abilities for the capture of persistent water contaminants such as oils and microplastics. We expect that this strategy could serve as inspiration for the construction of more intricate multiscale structures that could greatly expand the library of HOF materials.
Electrochemical Skeletal Indole Editing via Nitrogen Atom Insertion by Sustainable Oxygen Reduction Reaction
Authors: Zhang Bo‐Sheng , Homölle Simon L. , Bauch Tristan , Oliveira João C. A. , Warratz Svenja , Yuan Binbin , Gou Xue‐Ya , Ackermann Lutz
Published: July 2024

Skeletal molecular editing gained considerable recent momentum and emerged as a uniquely powerful tool for late‐stage diversifications. Thus far, superstoichiometric amounts of costly hypervalent iodine(III) reagents were largely required for skeletal indole editing. In contrast, we herein show that electricity enables sustainable nitrogen atom insertion reactions to give bio‐relevant quinazoline scaffolds without stoichiometric chemical redox‐waste product. The transition metal‐free electro‐editing was enabled by the oxygen reduction reaction (ORR) and proved robust on scale, while tolerating a variety of valuable functional groups.
Bimetallic magnetic nanoparticles dispersed in glycerol: An efficient hydrophilic catalyst for the reduction of 4‐nitrophenol
Authors: Mary Selvaraj Angel Anusuya , Stella Selvaraj
Published: July 2024

A one‐pot, ecologically friendly method for the preparation of Fe/Ni, Fe/Co and Co/Ni bimetallic magnetic nanoparticles (MNPs) was reported, using glycerol as both a solvent and reducing agent. Six different bimetallic MNPs by varying the proportions of transition metals, namely, Fe, Co and Ni were synthesized by the chemical reduction method. The catalytic efficiency of the synthesized nanoparticles (NPs) was explored for the reduction of 4‐nitrophenol, and the reaction rate for different catalysts was systematically analysed. Especially, glycerol‐Fe/Co (1:3) bimetallic nanoparticles as a magnetically recoverable catalyst had higher catalytic activity than the other bimetallic nanoparticles for the reduction of 4‐nitrophenol to 4‐aminophenol in the presence of sodium borohydride. The reduction process was monitored by UV–visible spectroscopy, and the reaction was complete within 8 min. The kinetic study shows 99% conversion of 4‐nitrophenol to 4‐aminophenol, and the rate constant is 0.593 min−1. Furthermore, the glycerol‐Fe/Co (1:3) MNPs were retrieved from the reaction mixture and subsequently utilized in five consecutive cycles, demonstrating both the reusability and durability of the NPs as a catalyst. This research was remarkable for its fast reaction kinetics, simplified one‐pot conversion of 4‐nitrophenol to 4‐aminophenol without the need for mechanical or magnetic stirring and in‐depth study of six bimetallic MNPs' catalytic properties in nitro reduction. These findings explored the potential benefits of bimetallic magnetic NPs for the synthesis of 4‐aminophenol products.
Tertiary phosphine‐supported diiron model complexes relevant to [FeFe]‐hydrogenases
Authors: Gao Yan , Jin Bo , Zhang Jin‐Liang , Jing Xing‐Bin , Zhao Pei‐Hua
Published: July 2024

In an effort to better probe the structure–function relationship on the biological [Fe4S4] cluster of [FeFe]‐hydrogenases, a new library of tertiary phosphine‐supported diiron dithiolate complexes [Fe2(μ‐adtNR)(CO)5{P(C6H4X)3}] (1–3) with various substituents (X = F vs. H vs. Me), wherein adtNR is denoted as abbreviation for the (SCH2)2N(C6H4C2H4OC(O)CH2C6H4Me) unit, is prepared as the active site mimics of [FeFe]‐hydrogenases. Notably, the substituent influences of tertiary phosphines on the structures and electrochemical behaviors of 1–3 are studied by spectroscopic and crystallographic techniques as well as cyclic voltammetry. For example, the electronic effect of tertiary phosphines [P(C6H4X)3] is responsible for the electron density around diiron center and the key Fe–Fe as well as Fe–P lengths in 1–3 as revealed by IR spectroscopy and crystallographic analysis. Further, complexes 1–3 show the electrochemical activity for proton reduction into molecular hydrogen (H2) using acetic acid (AcOH) as a proton source. Noticeably, F‐substituent‐containing diiron model complex 1 exhibits greater turnover frequency (i.e., turnover frequency value) and similar overpotential for electrocatalytic H2 evolution relative to H‐ or Me‐substituent‐bearing diiron homologs 2 or 3.
Deep eutectic solvent engineered GO/ZrO2 nanofiller for mixed matrix membranes: An efficient hydrogen gas separation
Authors: Chavda Vishwajit , Patel Harsh D. , Patel A. K. , Hirpara Darshna , Acharya N. K. , Kumar Sanjeev
Published: July 2024

This study explores fabrication and characterization of mixed matrix membranes (MMMs) for gas separation, employing a cost‐effective solution casting method. Polycarbonate (PC) and polystyrene (PS) blends are combined with graphene oxide (GO) and zirconium dioxide (ZrO2) nanofillers, with and without a deep eutectic solvent (DES) obtained through hydrogen bond exchange. Various MMMs compositions (2–20 wt%) are systematically examined using diverse characterization techniques, including differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, porosity determination, and water contact angle analysis. The MMMs exhibit enhanced gas permeability and selectivity, surpassing conventional membrane materials. Notably, H2 gas permeability reaches outstanding levels, with the composition PC/PS‐DES‐GO/ZrO2 at 20 wt% (PBC20‐IV) demonstrating the highest value of 86.32 Barrer. This superior performance is attributed to the unique properties of ZrO2, increased sorption capacity of GO, and enhanced thermal stability due to DES. Permeability data for CO2, N2, O2, and CH4 also show significant values, aligning with the observed trends in H2 permeability. Robeson's plot for the H2/CO2 gas pair surpasses the 2008 upper bound, placing the MMMs in a novel category for gas separation membranes. The incorporation of DES‐modified nanofiller blend composites presents a promising strategy for the potential production of pure hydrogen.
Torrefied spent coffee grounds as biofillers for poly(butylene adipate‐co‐terephthalate) biocomposites
Authors: Kim Youngsan , Kwon Sangwoo , Park Su‐il
Published: July 2024

In this study, poly(butylene adipate‐co‐terephthalate) (PBAT) biocomposites were generated from spent coffee grounds (SCGs) or torrefied SCG (TSCGs) using a melt compounding process. TSCGs were obtained at torrefaction temperatures of 230, 245, 260, 275, or 290°C for a duration of 60 min. Torrefaction enhanced the hydrophobicity, grindability, and biomass stability of the resulting composites by eliminating hemicellulose. Various concentrations of SCGs (10 and 20 wt.%) and TSCGs (10, 20, and 30 wt.%) were compounded into PBAT. The thermal, mechanical, and degradation properties of PBAT biocomposites were investigated. As SCGs and TSCGs were introduced, the crystallization temperature drastically increased. Compared with PBAT biocomposites with SCGs, PBAT biocomposites with TSCGs exhibited higher thermal stability and hydrophobicity, and improved mechanical properties. Further, alkaline hydrolysis occurred at a faster rate for biocomposites with biofillers than for neat PBAT. Therefore, this study demonstrated the improved compatibility between SCGs and PBAT by torrefaction.
Improvement of polycaprolactone and polyethylene glycol flexible polymeric film enhances bone volume and interconnectivity in bone lesions through transport of mesenchymal stem cells differentiated to osteoblasts
Authors: Jayme Cristiano C. , Fernandes Daniela S. , Matsuo Flávia S. , de Paula Leonardo B. , Osako Mariana K. , Tedesco Antonio C.
Published: July 2024

Bone fractures are one of the most common types of human injury. This study aimed to create a synergistic action of polymeric films (PFs) based on polycaprolactone (PCL) and polyethylene glycol (PEG) (PCL‐PEG‐PFs) deposited by casting, combined with mesenchymal stem cells (MSCs) that differentiate into osteoblasts for bone regeneration. In vitro experiments indicated that the PCL‐PEG‐PFs (70:30) exhibited low cytotoxicity and enhanced cell adhesion capacity. In vivo studies were performed to evaluate the bone regeneration capacity of PFs with MSCs that adhered to and differentiated into osteoblasts. The cell differentiation process was carried out for 18 days in cell culture for subsequent implantation in the calvaria of male C57BL/6J mice, which remained in contact with the bone lesion for another 14 days. In vivo studies indicated that the application of PCL‐PEG‐PFs (70:30) increased the bone surface area to the total volume, with significant regeneration areas (levels greater than 25%) and interconnectivity compared to the control. In addition, the generated tissue presented cells with a morphology comparable to that of the peripheral tissue of the injured region, indicating a positive synergistic interaction between PCL‐PEG‐PFs (70:30) and MSCs differentiated into osteoblasts in contact with the bone lesion.
Flexible and recyclable thermally conductive phase change composites with shape stability
Authors: Xu Yaofei , Sun Junyan , Feng Yixin , Lin Bili , Luo Fubin
Published: July 2024

Form‐stable and flexible highly thermally conductive phase change composites are crucial for thermal management. In this work, based on the associative exchangeable crosslinkers derived from the reaction of epoxidized soybean oil (ESO) and sebacic acid (SA), a kind of flexible and recyclable thermally conductive phase change composite with shape stability is prepared. The shape stabilization is achieved through the co‐cooperation of expanded graphite (EG) and the dynamic covalent crosslinking network. The thermal conductivity is enhanced by embedding with boron nitride (BN). When the mass fraction of BN is 25%, the thermal conductivity of the composite can reach 4.03 W/(m·K). The results indicate that the prepared PCMs composites have excellent flexibility and form stability, suggesting the potential application in the thermal management for electronic devices. The presence of dynamic exchangeable bonds makes the matrix degradable under mild conditions, enabling the recycling of valuable thermally conductive fillers, which proves to be highly sustainable. This work introduces a novel method for preparing flexible and recyclable thermally conductive phase change composites with shape stability vitrimer.
Electrospun chitosan/polymethyl methacrylate nanofiber membranes integrated with polyethyleneimine for enhanced removal of chromium(VI) ions
Authors: Yu Mengyun , Xu Weiwei , Sun Jianjun , Liu Zhiyong , Ding Guangjun , Gao Jiangang , Zhang Zongrui
Published: July 2024

This study demonstrates the preparation of a unique chitosan (CS)/polymethyl methacrylate (PMMA)/polyethyleneimine (PEI) nanofiber (NF) membrane using PMMA as the composite skeleton through an electrospinning method. The chemical and mechanical properties, chromium (Cr) adsorption capabilities, and mass transfer mechanisms of the NF membrane were thoroughly investigated. The findings indicate that the CS/PMMA/PEI NF membranes, with an average diameter of approximately 856.2 nm, exhibits favorable hydrophilicity, effective Cr(VI) adsorption (first adsorption capacity of 226.5 mg g−1), and robust mechanical properties (tensile strength of 1.58 ± 0.092 Mpa), which is superior to most reported adsorbents. Moreover, the composite NF membranes exhibit a second adsorption capacity of 194.4 mg g−1 and a tensile strength of 0.739 ± 0.072 Mpa after the second adsorption, indicating a remarkable level of reusability and cycle stability. Additionally, x‐ray photoelectron spectroscopy, and structural tests reveal the presence of abundant amino (NH2) and hydroxyl (OH) groups in the CS/PMMA/PEI NF membranes, suggesting potential sites for complexation reactions and the reductions of Cr(VI) ions, thereby facilitating effective adsorption and removal of heavy metals. This study introduces a novel and straightforward approach for synthesizing highly effective adsorbents, with have potential implications for the removal of heavy metal ions from wastewater.
Carbon dioxide‐based poly(hydroxyurethane‐urea) elastomers: Synthesis, microphase structure, and properties
Authors: Jiang Shan , Han Tianyi , Tian Tongshuai , Yang Chuanqing , Liu Li
Published: July 2024

Compared with isocyanate‐based polyurethanes (PUs), poly(hydroxyurethane)s (PHUs) are more likely to form phase mixing structure, inducing poor elastic properties. To avoid this, stronger interaction between hard segments is required. Herein, carbon dioxide‐based poly(hydroxyurethane‐urea)s (PHUUs) with different hard segment contents were prepared through polyaddition reaction using 5‐membered dicyclic carbonate (BADC) as hard segment, poly(propylene glycol) bis(2‐aminopropyl ether) (D2000) as soft segment, and amino‐terminal polyurea oligomer (HMDA*) chain extender, and several PHUs were prepared by using hexamethylenediamine (HMDA) chain extender or without using chain extender as controls. The interaction between hard segments were strengthened with the introduce of chain extender. Compared with PHUs, PHUUs with HMDA* chain extender were more inclined to form significant microphase separation. For PHUUs, the hard segment Tg appeared at around 60°C when hard segment content reached 40 wt%, and the interdomain spacings were in the range of around 14–23 nm with 40–50 wt% hard segment content. In addition, PHUUs exhibited better solvents resistance and mechanical properties than PHUs with the same hard segment content. PHUUs with certain hard segment content showed good elastic recovery, with a residual strain less than 2% after 10 cycles, which comparable with conventional isocyanate‐based PUs.
Mechanics of dissolving microneedles insertion into the skin: Finite element and experimental analyses
Authors: Babapour Fatemeh , Faraji Rad Zahra , Ganji Fariba
Published: July 2024

Transdermal drug delivery using dissolving microneedles (DMNs) is promising due to increased patient compliance and safety. This article presents a comprehensive simulation and experimental analysis of DMNs with varying tip and base diameters and polymers. The objective of the simulation study is to identify the optimal tip and base diameter of DMNs, as well as the most suitable polymer, for achieving maximum penetration depth. The simulation results showed that the compound consisting of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) in a ratio of 2:1, with a tip radius of 17.5 μm and a base radius of 150 μm, achieved the deepest penetration among the different types of polymers investigated (including PVA, hyaluronic acid (HA), and PVA/PVP in ratios of 1:1 and 1:2). In addition, mechanical and skin penetration experiments were performed on PVA/PVP 2:1 DMNs with varying concentrations of 4, 7, 10, and 15% w/w to determine the optimal polymer concentration. The results of this study indicated that the optimal composition, considering the viscosity of the polymer solution and the simplicity of filling the silicone negative molds, is a PVA/PVP 2:1 with a concentration of 7% w/w.
Robust stability and H∞$$ {H}_{\infty } $$ performance evaluation for time‐varying‐delayed uncertain linear systems based on variable‐augmented‐based free‐weighting matrices
Authors: Chen Dong‐Shuai , Shangguan Xing‐Chen , He Yong
Published: July 2024

The problem of the robust stability and
performance evaluation of time‐varying‐delayed uncertain linear systems (TVDULSs) is studied in this article. At first, to obtain a modified robust delay‐dependent condition of TVDULSs, a novel augmented Lyapunov‐Krasovskii functional (LKF) is established, and a variable‐augmented‐based free‐weighting matrices (VAFWMs) technique is tailored to evaluate the functional derivative. Compared with the existing robust stability methods, the constructed functional takes fully time delay information of the system into consideration and provides more delay‐cross terms, where the corresponding matrices are used to relax the constraints of linear matrix inequalities in the stability condition. Also, the VAFWMs method fully considers the linear relation of some delayed integral terms in the functional derivative, which avoids the usage of a quadratic order or higher order terms of the time delay. Then, an improved
performance analysis criterion of TVDULSs is obtained against the disturbance on the basis of the proposed robust stability condition. The admissible maximal delay upper bounds that the uncertain linear system can tolerate are provided by proposed criterion under a given
performance level. At last, two numerical examples are presented to verify the effectiveness and the superiority of the methods obtained.
RNA sequencing reveals the potential mechanism of exercise preconditioning for cerebral ischemia reperfusion injury in rats
Authors: Wu Yan , Yang Hui , Chen Feifeng , Li Baohua , Meng Xiangbo
Published: July 2024

Introduction

Cerebral ischemia reperfusion injury (CIRI) often leads to deleterious complications after stroke patients receive reperfusion therapy. Exercise preconditioning (EP) has been reported to facilitate brain function recovery. We aim to explore the specific mechanism of EP in CIRI.

Methods

Sprague‐Dawley rats were randomized into Sham, middle cerebral artery occlusion (MCAO), and EP groups (n = 11). The rats in the EP group received adaptive training for 3 days (10 m/min, 20 min/day, with a 0° incline) and formal training for 3 weeks (6 days/week, 25 m/min, 30 min/day, with a 0° incline). Then, rats underwent MCAO surgery to establish CIRI models. After 48 h, neurological deficits and cerebral infarction of the rats were measured. Neuronal death and apoptosis in the cerebral cortices were detected. Furthermore, RNA sequencing was conducted to investigate the specific mechanism of EP on CIRI, and qPCR and Western blotting were further applied to confirm RNA sequencing results.

Results

EP improved neurological deficit scores and reduced cerebral infarction in MCAO rats. Additionally, pre‐ischemic exercise also alleviated neuronal death and apoptosis of the cerebral cortices in MCAO rats. Importantly, 17 differentially expressed genes (DEGs) were identified through RNA sequencing, and these DEGs were mainly enriched in the HIF‐1 pathway, cellular senescence, proteoglycans in cancer, and so on. qPCR and Western blotting further confirmed that EP could suppress TIMP1, SOCS3, ANGPTL4, CDO1, and SERPINE1 expressions in MCAO rats.

Conclusion

EP can improve CIRI in vivo, the mechanism may relate to TIMP1 expression and HIF‐1 pathway, which provided novel targets for CIRI treatment.