bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges to the Formation of Nano-cells in Foaming Processes
Authors: Zhu Z. , Park C. B. , Zong J. H.
Published: June 2008

This paper uses a finite element analysis to investigate the morphological changes of nano-cells in a polystyrene (PS) – CO2 foaming system. The system was composed of a finite polymer melt with a central cell and eight surrounding cells. The computational domain was discretized using linear triangular elements. The growth and shrinkage of nano-sized cells were tracked using the moving mesh method. The effects of the initial bulk gas concentration, cell size, intercellular distance, and system temperature on cell ripening were examined. The results show that smaller nano-sized cell(s) are doomed to collapse very quickly once they have interacted with larger cell(s), making it difficult to survive. Efforts were made to improve the general understanding of the challenges posed to the formation of nano-cells in foaming processes.
Experimental Study on the Sliding Friction and Wear Characteristics of Roller Burnished Polymers
Authors: Ong L. K. , El-Tayeb N. S. M. , Brevern P. V.
Published: June 2008

The increasing utilization of polymers in sliding members has triggered much research on the enhancement of surface quality and tribological performance. In this regard, no work has considered the application of roller burnishing as a new surface treatment method for polymeric surfaces. The present work aims to investigate the influence of burnishing feed and roller contact width on the sliding friction and wear performance of acetal homopolymer and polyurethane. Dry and lubricated sliding conditions for both parallel and crossed burnished orientations were considered. The results revealed that low burnishing feed rate and smaller roller contact width led to a decrease in coefficient of friction for both polymers while improvement in the wear resistance was observed. Hence, it can be suggested that the roller burnishing process has high potential as a valuable polymer surface treatment technique.
Rheological Behavior of Immiscible PS/PMMA Blends during Dynamic Plasticating Extrusion
Authors: Luo W. H. , Zhou N. Q. , Peng X. F.
Published: June 2008

PS/PMMA blends were prepared using a twin screw extruder and then extruded using an electromagnetic dynamic plasticating extruder equipped with a specially designed split die. During dynamic plasticating extrusion, the dynamic rheological behavior of PS/PMMA blends was investigated. The extrudates were cooled immediately and collected for morphology measurements using a scanning electron microscope (SEM). Results show that the average shear stress decreases with the introduction of vibration force field into the whole extrusion process, and reaches a minimum at the vibration amplitude of 0.15 mm and the vibration frequency of 5 Hz. At the same shear stress, the melt viscosity of the blend under dynamic plasticating extrusion is lower than that under static extrusion and decreases with vibration intensity. With increasing vibration intensity, the power-law index of the blend melt has a tendency to increase. The drop size of the dispersed phase in 25/75 PS/PMMA blend decreases at a faster rate with an increase of shear stress, compared with that in 75/25 PS/PMMA blends, correspondingly, the melt viscosity of 25/75 PS/PMMA blend has a stronger shear rate dependence. During dynamic plasticating extrusion, a negative deviation from the additivity rule is observed for the studied blend compositions.
Inhibition of Thermal Oxidation Destruction of PBT/HDPE Blends by Organic Compounds of Five-valent Phosphorus
Authors: Ozden S. , Borukayev T. A. , Shaov A. K.
Published: June 2008

Polybutylene terephthalate (PBT) and highy density polyethylene (HDPE) were blended and stabilized with four different stabilizers obtained from the organic derivatives of five-valent phosphorus. These stabilizers were cyclohexylphosphonic acid, its metallic salts of cyclohexyl phosponates of bivalent nickel, bivalent iron and trivalent iron. The stabilization improved the thermal stability of the PBT/HDPE blends and increased their mass loss temperature. The blend melts were thermally aged inside a viscometer barrel and the Melt flow Index (MFIs) was measured. All stabilizers increased the melt stability of the blends when used in low rates (< 0.2 % in mass). At higher stabilizer rates, some stabilizers further enhanced the thermal stability, while others decreased it. A melt parameter was introduced to determine the melt stability of the PBT/HDPE blends during extrusion. The best stabilization was obtained with cyclohexylphosphonic acid based on the metallic salts of bivalent nickel. The mechanisms that lead to the inhibition of thermal destruction of the blends were explained in terms of the stabilizers.
Non-isothermal Model for the Drive Power Calculation of Single-screw Plasticating Units
Authors: Potente H. , Bornemann M.
Published: June 2008

This paper presents a non-Isothermal numerical model developed at the KTP for calculating the drive power of single-screw plasticating units. It includes, firstly, a description of the mathematical and physical modeling process and, secondly, an explanation of the systematic approach, based on statistical methods, that was adopted for compiling an approximation equation with the aid of non-isothermal, three-dimensional FEA flow simulation results. In addition, the generated model is verified on the basis of the computation results obtained with a simulation program for screw layout, in which the model was implemented. The simulation results are compared with experimentally recorded power data for selected extrusion and injection molding processes and the quality of the model is subsequently assessed.
Stakeholder Perspectives on Regulatory Aspects of Antarctic Tourism
Authors: Haase Daniela , Storey Bryan , McIntosh Alison , Carr Anna , Gilbert Neil
Published: June 2008

Over the last decade, Antarctic tourism has experienced an exponential growth in tourist numbers and a diversification of tourist activities resulting in questions that challenge the effectiveness and adequacy of the current regulatory regime. Three categories of key Antarctic tourism
stakeholders—regulators, organizers, and monitors—were interviewed and provided their perspective on some of the main aspects of Antarctic tourism regulation. The current and anticipated future state of Antarctic tourism, tourism practice and ethos, the success of regulatory mechanisms
through the Antarctic Treaty System and International Association of Antarctica Tour Operators (IAATO), and the cooperation between the stakeholder groups are explored to draw conclusions about the effectiveness of the regulatory regime. The study confirms that currently Antarctic tourism
can be adequately regulated through existing mechanisms, but that growing numbers of tourists and vessels may require more stringent tools to be adopted. Site-specific guidelines are identified as effective tools for a targeted and flexible regulation of primarily ship-borne tourism.
Tourism in the South Shetland Islands: Recent Changes in Local Destinations and Activities
Authors: Serrano Enrique
Published: June 2008

Antarctic tourism has been developed in the archipelago since the 1960s, but its growth has been remarkable since the beginning of the 1990s. The South Shetland Islands are the most visited tourist destination in the Antarctic and the Islands were visited by 22,604 tourists in the 2005–2006
season. Three phases of tourist activity can be distinguished: initial development (1965–1985), growth and consolidation (1985–1998), and growth and diversification (1998–2006). Changes have been detected in the tourist activities and frequentation of visitors to different
sites. The last phase is characterized by the multiplication of annual trips and the diversification of tourist activities, typically from landings with short walks and visits to scientific stations, to new tourism activities that are more active in nature. Visits are concentrated in seven
geographical areas and specialization in specific activities has developed at different sites. This article examines the evolution of maritime tourism, the use, frequency, and development of local tourist sites on the South Shetland Islands.
The Commencement of Regular Arctic Cruise Ship Tourism: Wilhelm Bade and the "Nordische Hochseefischerei Gesellschaft" of 1892/1893
Authors: Barthelmess Klaus
Published: June 2008

The opening of tourism in northern Norway in the 1870s coincided with the emergence of Tromsø as a port for Arctic research expeditions, as well as with the founding of modern whaling stations along the North Norwegian coast, tourist attractions themselves. One of the first entrepreneurs
of tourism to northern Norway was a German by the name of Captain Wilhelm Bade. He was the first to regularly accompany cruise tourists to the Arctic Svalbard archipelago (Spitzbergen). Bade was a survivor of an 8-month drift on an ice floe after the wreck of a German polar expedition ship
in 1869/1870. As a result of this experience he propagated an image of a friendly Arctic yielding sustenance to its human inhabitants as well as profit to nonnative entrepreneurs. In 1892, Bade cofounded the "Nordische Hochseefischerei Gesellschaft" (Nordic Sea Fisheries Company) in Mülheim
an der Ruhr, a center of the German industrial mining area. Arctic coal mining was one of the business purposes of the company, which had leading German industrialists on board. The other purposes were whaling and Arctic tourism. A tourist steamer went to Spitzbergen in company of a whale
catcher. Passengers could board the whaler to witness a whale hunt. Mining efforts by the company failed, as did fishing attempts and whaling. The company went into liquidation after its first season, but Spitzbergen tourism had proved its economic potential, attracting immediate competition,
while Bade and Sons continued chartering cruise ships to Spitzbergen until 1908.
Tourism Growth and Proposed Management Solutions in the Fildes Peninsula Region (King George Island, Antarctica)
Authors: Pfeiffer Simone , Buesser Christina , Mustafa Osama , Peter Hans-Ulrich
Published: June 2008

Tourism is a rapidly growing industry in the Antarctic, particularly on King George Island where wildlife areas, research stations, or their vicinity are frequently visited. A comprehensive assessment of the environment and human activities in the Fildes Peninsula region was conducted,
and spatiotemporal patterns were analyzed. Additionally, opinions on tourism of station members were surveyed. Visitor activity is increasing and diversifying. There is thus some conflict with conservation, research, and logistics, although it is currently local and temporary. Increasing human
activity and its possible cumulative effects should be monitored and appropriately managed. On the basis of our findings, site-specific guidelines and visitor zones (e.g., within an "Antarctic Specially Managed Area") are recommended.
Working Towards Policy Creation for Cruise Ship Tourism in Parks and Protected Areas of Nunavut
Authors: Marquez Janet R. , Eagles Paul F. J.
Published: June 2008

This article provides an understanding of the goals and operational procedures of current cruise ship operators in Nunavut and gives insight into the policies necessary to effectively manage cruise ship tourism in Nunavut. The exploratory research found that cruise tourism in Nunavut
is perceived as a safe and economically viable industry. However, a number of important issues emerged: 1) the need for policies and guidelines to aid in the management of parks and protected areas in Nunavut; 2) the desire for unity across the Arctic cruise ship tourism industry; 3) the requirement
for greater government awareness and assistance; and 4) the need for more research, particularly from local perspectives.
Management of Tourism in the Marine Environment of Antarctica: The IAATO Perspective
Authors: Landau Denise , Splettstoesser John
Published: June 2008

Management of tourism in Antarctica has been the combined responsibility of Antarctic Treaty Parties and the International Association of Antarctica Tour Operators (IAATO) since 1991 when IAATO was formed. With the growth of tourism during the past 15–20 years, management strategies
developed by IAATO included establishing categories of membership that are tailored to accommodate size of vessels and passenger capacity, plus a variety of steps taken to ensure environmental protection. These are mentioned in detail in the following sections. Benefits of Antarctic tourism
are many, such as spin-offs that assist science programs through "ships of opportunity" by way of transporting science personnel and gear, as well as in numerous observations of marine wildlife by tour company naturalists.
Estimating the Greenhouse Gas Emissions from Antarctic Tourism
Authors: Amelung Bas , Lamers Machiel
Published: June 2008

Tourism in Antarctica is rapidly growing and diversifying, which raises concerns about its effects on the environment. Research and policy-making efforts have so far focused on the impacts on Antarctica's own ecosystems, whereas global impacts have all but been ignored. This article
presents an inventory of greenhouse gas emissions produced by Antarctic tourism. Emissions are shown to be considerable, with aviation and cruises being the main sources. Tourism to the Antarctic ranks among the most energy-intensive segments in the tourism market. It is argued that greenhouse
gas emissions should be included in environmental impact assessments. Improving the global environmental performance of Antarctic tourism is difficult, because of its exclusive dependency on long-haul trips.
Antarctic Whales and Antarctic Tourism
Authors: Williams Rob , Crosbie Kim
Published: June 2008

Shipboard visitors to the Antarctic are routinely rewarded with whale sightings. However, careful management and dedicated research are needed to ensure that the growing Antarctic marine tourism industry does not inadvertently harm these populations, which are recovering from heavy
exploitation in the early part of the 20th century. Ongoing research by the International Whaling Commission (IWC) aims to monitor whale population recovery, and the International Association of Antarctica Tour Operators (IAATO) has developed operational guidelines to minimize and mitigate
potential impacts, some specific to marine mammals and marine wildlife watching. Nonetheless, while boat-based tourism has the potential to affect whales, responsible tourism also has a substantial contribution to make to Antarctic whale conservation and research through collaboration.
Underneath the Radar: Emergency Search and Rescue Insurance for East Antarctic Tourism
Authors: Jabour Julia
Published: June 2008

Operators of tourism activities in the Antarctic will soon be legally required to hold adequate insurance for emergency search and rescue. This may push some operators underground because they cannot afford to pay. The intent of the new law is to encourage compliance with tourism best
practice and self-sufficiency. In the East Antarctic, maritime search and rescue is problematic due to limitations on the response capability. When Australia and New Zealand implement this law they may make provision for cost recovery, otherwise the insurance requirement is meaningless. However,
cost recovery overlaps with obligations they have under the SAR Convention to provide emergency search and rescue as a maritime community service, foregoing cost recovery.
Antarctic Gateway Ports: Opening Tourism to Macquarie Island and the East Antarctic from Hobart
Authors: Muir Shona , Jabour Julia , Carlsen Jack
Published: June 2008

This article discusses the significance of Antarctic gateway ports, and identifies the key issues and challenges in developing East Antarctic tourism, especially through the port of Hobart. Recent opportunities have emerged through increased ship-borne and pending air-borne capacity
from Hobart, and a network of government and private agencies have made Hobart the locus of these services. This presents an opportunity to investigate the needs and expectations of tourists through the gateways with a view to developing products and services to meet those needs and expectations.
Findings from a preliminary survey of East Antarctic tourists in the 2005–2006 season are presented and a model for developing tourism to the East Antarctic from Hobart is proposed.
How mathematical dispositions of adult learners play a role in their STEM choices
Authors: Jameson Molly M.
Published: April 2024

Mathematical dispositions, or an individual's behavioral (i.e., things they say and do), cognitive (i.e., attention and memory), and affective (i.e., emotions and beliefs) tendencies related to mathematics, are critical to the learning of mathematics and choices related to STEM. Previous research has suggested that adult learners may possess unproductive mathematical dispositions, such as high math anxiety and low math self‐efficacy. This paper argues that unproductive mathematical dispositions may serve as a barrier to adult learners' STEM choices and provides strategies and techniques to help move adult learners towards productive mathematical dispositions and potentially stronger attraction to STEM fields.
Incorporation of artificial intelligence in healthcare professions and patient education for fostering effective patient care
Authors: Mucci Andrea , Green Wendy M. , Hill Lilian H.
Published: April 2024

Artificial intelligence (AI) influences many aspects of modern life and has multiple applications in the delivery of healthcare. AI is designed to mimic human capabilities including pattern recognition, data analysis, and decision‐making and perform tasks more efficiently. It is capable of detecting patterns in large datasets that might elude human beings. AI has potential to improve patient care, patient safety, disease diagnosis and treatment; public health; health research; health administration; and the daily work of health professionals. In 2019, the US National Academy of Medicine emphasized the need for “physicians, nurses, and other clinicians, data scientists, health care administrators, public health officials, policy makers, regulators, purchasers of health care services, and patients to understand the basic concepts, current state of the art, and future implications of the revolution in AI and machine learning.” Therefore, it is incumbent on adult educators to incorporate AI training into health professions education and patient education.
Effects of explainable artificial intelligence in neurology decision support
Authors: Gombolay Grace Y. , Silva Andrew , Schrum Mariah , Gopalan Nakul , Hallman‐Cooper Jamika , Dutt Monideep , Gombolay Matthew
Published: April 2024

Objective

Artificial intelligence (AI)‐based decision support systems (DSS) are utilized in medicine but underlying decision‐making processes are usually unknown. Explainable AI (xAI) techniques provide insight into DSS, but little is known on how to design xAI for clinicians. Here we investigate the impact of various xAI techniques on a clinician's interaction with an AI‐based DSS in decision‐making tasks as compared to a general population.

Methods

We conducted a randomized, blinded study in which members of the Child Neurology Society and American Academy of Neurology were compared to a general population. Participants received recommendations from a DSS via a random assignment of an xAI intervention (decision tree, crowd sourced agreement, case‐based reasoning, probability scores, counterfactual reasoning, feature importance, templated language, and no explanations). Primary outcomes included test performance and perceived explainability, trust, and social competence of the DSS. Secondary outcomes included compliance, understandability, and agreement per question.

Results

We had 81 neurology participants with 284 in the general population. Decision trees were perceived as the more explainable by the medical versus general population (P < 0.01) and as more explainable than probability scores within the medical population (P < 0.001). Increasing neurology experience and perceived explainability degraded performance (P = 0.0214). Performance was not predicted by xAI method but by perceived explainability.

Interpretation

xAI methods have different impacts on a medical versus general population; thus, xAI is not uniformly beneficial, and there is no one‐size‐fits‐all approach. Further user‐centered xAI research targeting clinicians and to develop personalized DSS for clinicians is needed.
Fuzzy sliding mode tracking control of discrete‐time nonlinear interconnected systems via a previewable approach
Authors: Qin Xianghui , Ren Junchao
Published: April 2024

This article investigates the fuzzy sliding mode tracking problem for discrete‐time nonlinear interconnected systems (ICSs) via a previewable information approach. First, an augmented system containing tracking errors and previewable reference and disturbance signals is established for discrete‐time nonlinear ICSs according to a previewable length. Second, novel sliding surfaces are given and some sufficient conditions of making the sliding motion asymptotically stable are derived in term of linear matrix inequalities (LMIs). Next, fuzzy sliding mode control (SMC) laws are designed so that the controlled system can reach the sliding surfaces and keep on them thereafter, and compared to not having previewable signals, these designed control laws can also enable system outputs to better track the reference signals asymptotically. Finally, a simulation example is given to demonstrate the effectiveness of the proposed control law.
Fixed time function combination synchronization of perturbed chaotic systems via adaptive control
Authors: Su Haipeng , Luo Runzi
Published: April 2024

The concerns of this article is to investigate the fixed time function combination synchronization (FCS) among three different chaotic systems with disturbances. First, a new stability theorem is presented by virtue of the integral inequality technique and a more accurate upper estimation of the convergence time is given. Next, the fixed time FCS problem is considered for the perturbed chaotic systems in which the scaling functions are generated by the bounded dynamical systems. Besides, the synchronization time is related to the control parameters rather than the initial values. The time upper bound can be calculated out by the simple formula, which is the function of control parameters. Finally, a simulation example is provided to illustrate the correctness of the derived criteria.
Exploring the Role of Hyaluronic Acid in Reproductive Biology and Beyond: Applications in Assisted Reproduction and Tissue Engineering
Authors: Rashki Ghaleno Leila , Pennisi Cristian Pablo , Shahverdi Abdolhossein , Dardmeh Fereshteh , Alipour Hiva , Rezazadeh Valojerdi Mojtaba
Published: April 2024

Hyaluronic acid (HA) plays a prominent role in various aspects of reproductive biology and assisted reproductive technologies (ART). This review describes the multifaceted influence of HA, ranging from primordial germ cell migration, ovarian follicle development, and ovulation in females to sperm structure, physiology, motility, and capacitation in males. In addition, HA also plays an important role in fertilization and promotes embryo implantation by mediating cellular adhesion and communication within the uterus. Against this physiological background, the review examines the current applications of HA in the context of ART. In addition, the article addresses the emerging field of reproductive tissue engineering, where HA‐based hydrogels offer promising perspectives as they can support the development of mature oocytes and spermatogenesis in vitro. Overall, this review highlights the integral role of HA in the intricate mechanisms of reproductive biology and its growing importance for improving ART outcomes and the field of tissue engineering of the reproductive system.
Additive Manufacturing of TiC/Steel Composites Using Electron Beam Melting and In Situ Infiltration
Authors: Chen Yong , Fu Zongwen , Ye Jihui , Wahlmann Benjamin , Körner Carolin
Published: April 2024

Cemented carbides containing titanium carbide (TiC), characterized by low specific weight, superior hardness, and excellent high‐temperature resistance, are widely used as wear‐resistant cutting tools and brake discs. Instead of using conventional powder metallurgical approaches, composites comprising TiC and stainless steel are fabricated in this study by means of an innovative method combining electron beam powder bed fusion (PBF‐EB) and in situ liquid metal infiltration. For PBF‐EB, a pure TiC powder as feedstock and a stainless steel plate as substrate are used, respectively. Owing to the high processing temperature in the hatching area, the TiC particles are inhomogeneously sintered. Simultaneously, an in situ infiltration of liquid steel into the pores between TiC particles takes place during PBF‐EB, forming a dense and crack‐free composite material containing ≈68% TiC. The electrical properties of the raw TiC powder are investigated at different temperatures to optimize the process parameters ensuring high process stability during PBF‐EB. The microstructure and mechanical properties (compression strength, hardness, and fracture toughness) of the PBF‐EB‐produced TiC/steel composite are analyzed.
Effects of Solvents on the Material Properties of Screen‐Printed Electrodes and a Polydimethylsiloxane Dielectric for Dielectric Elastomer Transducers
Authors: Willian Tobias Pascal , Pohl Svenja , Bruch Daniel , Rizzello Gianluca , Motzki Paul , Kickelbick Guido , Seelecke Stefan
Published: April 2024

Dielectric elastomer transducers (DETs), namely, highly stretchable dielectric membranes sandwiched between two compliant electrodes, allow to develop sensors, actuators, and generator systems. DET performance is strongly influenced by the material properties of dielectric and electrodes, as well as the type of manufacturing process. For instance, when manufacturing the electrodes via screen‐printing, significant amounts of solvents are needed to adjust the printing materials’ viscosity, but they potentially alter DET properties. The investigation of this effect, however, is largely unexplored. Addressing this issue, this article investigates the influence of various solvents on a DET consisting of a polydimethylsiloxane (PDMS) membrane with PDMS/carbon black electrodes. Physical and chemical interactions between dielectric and solvents are characterized by infrared‐spectroscopy (IR), optical investigations, and light microscopy. Different solvents used for screen‐printing are analyzed in terms of their effects on the electrode electrical resistance, screen‐print image, and breakdown strength. Even though the solvent strongly affects the electrodes’ electrical resistance (ranging from ≈22 kΩ to >MΩ), it does not modify the breakdown strength of the pure dielectric (113 V μm−1). In the IR, no chemical aging is found. The obtained results provide systematic guidelines for the choice of solvents in DET electrode manufacturing.
A Library of Nanocrystal‐Inserted Ordered Mesoporous Frameworks with Ultrahigh Density and Spatial Dispersity
Authors: Zhang Wei , Shi Wenxiong , Wang Jinxiu , Zhu Kerun , Tian Yong , He Haili , Duan Linlin , Fang Huang , Liu Yupu , Wang Biwei , Ma Yuzhu , Zhao Tiancong , Zhang Xingmiao , Lv Zirui , Zu Lianhai , Tang Yun , Dong Angang , Kong Biao , Zhao Dongyuan
Published: April 2024

It is a great challenge to integrate incompatible subunits into ordered macroscopic materials with tailored functionalities. Herein, a facile modular assembly strategy is demonstrated to link incompatible colloidal nanocrystals and polymer micelles by using the phenolic resol as the “molecule glue” for the synthesis of nanocrystal‐inserted mesoporous frameworks with diverse functionalities. It is found that the uniform nanocrystals can be inserted into the mesoporous frameworks with outstanding spatial dispersity, even in the case of high incorporation density. This modular assembly route is versatile, a library of nanocrystals with diverse diameters, shapes, and compositions can be integrated into various kinds of mesoporous frameworks (carbon, carbon‐SiO2, and carbon‐TiO2 composites). Unprecedently, this strategy also allows the controllable assembly of two, even three types of nanocrystals within the mesoporous frameworks to achieve multiple functionalities. The as‐prepared nanocomposites can simultaneously exhibit catalytic, magnetic, and adsorption properties independently, and show synergistic effects for tandem catalytic applications.
Observing Proton–Electron Mixed Conductivity in Graphdiyne
Authors: Li Jiaofu , Wang Cong , Su Jiangtao , Liu Zhihua , Fan Hangming , Wang Changxian , Li Yanzhen , He Yongli , Chen Nuan , Cao Jinwei , Chen Xiaodong
Published: April 2024

Mixed conducting materials with both ionic and electronic conductivities have gained prominence in emerging applications. However, exploring material with on‐demand ionic and electronic conductivities remains challenging, primarily due to the lack of correlating macroscopic conductivity with atom‐scale structure. Here, the correlation of proton–electron conductivity and atom‐scale structure in graphdiyne is explored. Precisely adjusting the conjugated diynes and oxygenic functional groups in graphdiyne yields a tunable proton–electron conductivity on the order of 103. In addition, a wet‐chemistry lithography technique for uniform preparation of graphdiyne on flexible substrates is provided. Utilizing the proton–electron conductivity and mechanical tolerance of graphdiyne, bimodal flexible devices serving as capacitive switches and resistive sensors are created. As a proof‐of‐concept, a breath–machine interface for sentence‐based communication and self‐nursing tasks with an accuracy of 98% is designed. This work represents an important step toward understanding the atom‐scale structure–conductivity relationship and extending the applications of mixed conducting materials to assistive technology.
Precision Calcination Mechanism of CaCO3 to High‐Porosity Nanoscale CaO CO2 Sorbent Revealed by Direct In Situ Observations
Authors: Martinez Jenny , Wardini Jenna L. , Zheng Xueli , Moghimi Lauren , Rakowsky Jason , Means Jonathan , Guo Huiming , Kuzmenko Ivan , Ilavsky Jan , Zhang Fan , Dholabhai Pratik P. , Dresselhaus‐Marais Leora , Bowman William J.
Published: April 2024

Deploying energy storage and carbon capture at scale is hindered by the substantial endothermic penalty of decomposing CaCO3 to CaO and CO2, and the rapid loss of CO2 absorption capacity by CaO sorbent particles due to sintering at the high requisite decomposition temperatures. The decomposition reaction mechanism underlying sorbent deactivation remains unclear at the atomic level and nanoscale due to past reliance on postmortem characterization methods with insufficient spatial and temporal resolution. Thus, elucidating the important CaCO3 decomposition reaction pathway requires direct observation by time‐resolved (sub‐)nanoscale methods. Here, chemical and structural dynamics during the decomposition of CaCO3 nanoparticles to nanoporous CaO particles comprising high‐surface‐area CaO nanocrystallites are examined. Comparing in situ transmission electron microscopy (TEM) and synchrotron X‐ray diffraction experiments gives key insights into the dynamics of nanoparticle calcination, involving anisotropic CaCO3 thermal distortion before conversion to thermally dilated energetically stable CaO crystallites. Time‐resolved TEM uncovered a novel CaO formation mechanism involving heterogeneous nucleation at extended CaCO3 defects followed by sweeping reaction front motion across the initial CaCO3 particle. These observations clarify longstanding, yet incomplete, reaction mechanisms and kinetic models lacking accurate information about (sub‐)nanoscale dynamics, while also demonstrating calcination of CaCO3 without sintering through rapid heating and precise temperature control.
A High‐Performance Phosphate Potentiometric Sensor Based on Cobalt Nanoparticles Electroplated on Hierarchically Porous Laser‐Induced Graphene
Authors: Chang Muxuan , Tang Rui , Zou Wenke , Xian Jieyu , Zhang Zhengwei , Liu Xingye , Qu Menglong , Zhang Cheng
Published: April 2024

Phosphate is an important fertilizer in agriculture and electrochemical sensors based on cobalt (Co) are promising for measurement of phosphate. The deposition of Co onto conductive substrates to form a nano/microstructured Co layer with rich active sites is a typical strategy to improve detection performances. However, the widely used substrates show smooth surfaces, which cannot provide extra active sites. Herein, a high‐performance phosphate sensor is fabricated by generating Co nanoparticles (NPs) on a hierarchically porous laser‐induced graphene (LIG) matrix with a large surface area. Specifically, a Co layer is first electroplated on the LIG matrix. Nevertheless, the pores of LIG will be blocked by the dense Co layer so the performances of the fabricated LIG‐Co sensor exhibit limited enhancements. Therefore, a “nearly all etching (NAE)” technique is developed to transform the dense Co layer to dispersive Co NPs and re‐expose the pores of LIG, both increasing the active sites. Compared to the LIG‐Co sensor, the LIG‐Co NP sensor displays overall superiority. The response time, sensitivity, and linearity are enhanced from ≈60 to ≈10 s, from 0.012 to 0.069 V dec−1, and from 0.973 to 0.998, respectively. The LIG‐Co NP sensor also shows a decent anti‐interference capability.
Cationic Engineering Strategy to Achieve Controllable Room‐Temperature‐Phosphorescence in Hybrid Zinc Halides
Authors: Liu Yu‐Hang , Zhang Bing‐Lin , Wang Yu‐Jiao , Zhang Xiao‐Yang , Shang Yan‐Bing , Liu Tian‐Ci , Lei Xiao‐Wu , Chen Zhi‐Wei , Yue Cheng‐Yang
Published: April 2024

Despite rapid progress and wide applications of room temperature phosphorescence (RTP) materials, it is still a great challenge to optimize the RTP activity through rational structural design at a molecular level. Herein, a successful cationic engineering strategy is demonstrated to modulate the crystal flexibility achieving controllable RTP in a new pair of metal halides [APML]ZnCl4 ([APML] = N‐(3‐Aminopropyl)morpholine) and [AEML]ZnCl4 ([AEML] = N‐(2‐Aminoethyl)morpholine). Both halides display blue fluorescence under 365 nm UV. Comparing with longer [APML]+, shorter [AEML]+ significantly enhances crystal rigidity and restrains non‐radiative scattering, boosting photoluminescence quantum yield (PLQY) from 18.89% to 22.41%. Synchronously, enhanced crystal rigidity significantly promotes the inter‐system crossing from singlet to triplet excited states. As a consequence, [AEML]ZnCl4 displays long‐lived green RTP property with millisecond scale lifetime in contrast to the blank RTP activity of [APML]ZnCl4. Comprehensive investigations demonstrate that the energy transfer between inorganic and organic components greatly changes the redistribution of singlet and triplet excited states, resulting in distinct phosphorescence activity. The different short‐lived blue fluorescence and long‐lived green phosphorescence provide a color‐time‐dual‐resolved luminescent tag with advanced applications in anti‐counterfeiting, etc. This work highlights a new structural engineering strategy to achieve controllable RTP affording a guide to rationally design RTP materials.
Chiral P,N,N‐Ligands for Asymmetric Hydrogenation
Authors: Liang Ding‐Hua , Hou Chuan‐Jin , Li Qi , Qin Hao , Li Ling , Hu Xiang‐Ping
Published: April 2024

The chiral P,N,N‐ligands represented a new type of tridentate ligand developed in recent years and displayed wide utilities in asymmetric catalysis. In the past decades, numerous chiral P,N,N‐ligands with ferrocene, phenethylamine and spiro backbones were synthesized by addition of an aminopyridine, imidazole or diamines coordinating group. These chiral tridentate P,N,N‐ligands showed excellent performance in the ruthenium, iridium, manganese, or cobalt‐catalyzed asymmetric hydrogenations. A wide range of substrates, including simple ketones, α‐halogenated ketones, α‐hydroxy ketones, α‐ or β‐amino keto‐ ones, α‐, γ‐, or δ‐keto acids, α‐ or β‐keto amides, β‐ or δ‐keto esters, α‐ or β‐enones, olefins, imines, quinolines and indoles, could be hydrogenated to afford the corresponding chiral products with high yields and enantioselectivities. In this review, progress on the asymmetric hydrogenation of C=O, C=N, C=C bonds with chiral tridentate P,N,N‐ligands was summarized.
Machine Learning Approach for Predicting the Hole Mobility of the Perovskite Solar Cells
Authors: Rashid Md Al Mamunur , Lee Seul , Kim Kwang Ho , Kim Jaeoh , Jeong Keunhong
Published: April 2024

Traditional computational approaches such as Monte Carlo simulation, molecular dynamics, and density functional theory (DFT) have contributed to understanding the role of hole mobility in the development of suitable hole transporting materials (HTMs) for perovskite solar cell efficiency. However, these methods often involve significant computational expenses, thereby limiting the number of feasible studies and hindering the extraction of valuable structure−property guidelines for a rational design of novel HTMs. To address these challenges, this study proposes an ultrafast predictive model that balances prediction accuracy and time efficiency, a critical aspect for predicting the hole mobility of HTMs for perovskite optimization. The model, which leverages the Random Forest learning algorithm, enables comprehensive and rapid analysis of photovoltaic features taken from previous experiments/literature and processed with the RDKit Python library. Notably, recognizing the challenges associated with high correlation in the dataset, a method to improve the calculation of feature importance in random forests is applied. The results highlight bertz_ct, chi1, and logP as key predictive features of HTM performance. However, the model underscores the need to uncover additional predictive features based on structure–property relationships to predict the optimized hole mobility. This approach significantly accelerates the discovery process, outperforming prevalent statistical methods in the prediction of hole mobility and HTM performance. This research signifies a pivotal step toward cost‐effective, accelerated stability and efficiency of HTMs, with implications for the advancement of optoelectronic devices.
Building Haplotype‐Resolved 3D Genome Maps of Chicken Skeletal Muscle
Authors: Li Jing , Lin Yu , Li Diyan , He Mengnan , Kui Hua , Bai Jingyi , Chen Ziyu , Gou Yuwei , Zhang Jiaman , Wang Tao , Tang Qianzi , Kong Fanli , Jin Long , Li Mingzhou
Published: April 2024

Haplotype‐resolved 3D chromatin architecture related to allelic differences in avian skeletal muscle development has not been addressed so far, although chicken husbandry for meat consumption has been prevalent feature of cultures on every continent for more than thousands of years. Here, high‐resolution Hi‐C diploid maps (1.2‐kb maximum resolution) are generated for skeletal muscle tissues in chicken across three developmental stages (embryonic day 15 to day 30 post‐hatching). The sequence features governing spatial arrangement of chromosomes and characterize homolog pairing in the nucleus, are identified. Multi‐scale characterization of chromatin reorganization between stages from myogenesis in the fetus to myofiber hypertrophy after hatching show concordant changes in transcriptional regulation by relevant signaling pathways. Further interrogation of parent‐of‐origin‐specific chromatin conformation supported that genomic imprinting is absent in birds. This study also reveals promoter‐enhancer interaction (PEI) differences between broiler and layer haplotypes in skeletal muscle development‐related genes are related to genetic variation between breeds, however, only a minority of breed‐specific variations likely contribute to phenotypic divergence in skeletal muscle potentially via allelic PEI rewiring. Beyond defining the haplotype‐specific 3D chromatin architecture in chicken, this study provides a rich resource for investigating allelic regulatory divergence among chicken breeds.
Catalytically Active Carbon for Oxygen Reduction Reaction in Energy Conversion: Recent Advances and Future Perspectives
Authors: Liu Shuling , Wang Ao , Liu Yanyan , Zhou Wenshu , Wen Hao , Zhang Huanhuan , Sun Kang , Li Shuqi , Zhou Jingjing , Wang Yongfeng , Jiang Jianchun , Li Baojun
Published: April 2024

The shortage and unevenness of fossil energy sources are affecting the development and progress of human civilization. The technology of efficiently converting material resources into energy for utilization and storage is attracting the attention of researchers. Environmentally friendly biomass materials are a treasure to drive the development of new‐generation energy sources. Electrochemical theory is used to efficiently convert the chemical energy of chemical substances into electrical energy. In recent years, significant progress has been made in the development of green and economical electrocatalysts for oxygen reduction reaction (ORR). Although many reviews have been reported around the application of biomass‐derived catalytically active carbon (CAC) catalysts in ORR, these reviews have only selected a single/partial topic (including synthesis and preparation of catalysts from different sources, structural optimization, or performance enhancement methods based on CAC catalysts, and application of biomass‐derived CACs) for discussion. There is no review that systematically addresses the latest progress in the synthesis, performance enhancement, and applications related to biomass‐derived CAC‐based oxygen reduction electrocatalysts synchronously. This review fills the gap by providing a timely and comprehensive review and summary from the following sections: the exposition of the basic catalytic principles of ORR, the summary of the chemical composition and structural properties of various types of biomass, the analysis of traditional and the latest popular biomass‐derived CAC synthesis methods and optimization strategies, and the summary of the practical applications of biomass‐derived CAC‐based oxidative reduction electrocatalysts. This review provides a comprehensive summary of the latest advances to provide research directions and design ideas for the development of catalyst synthesis/optimization and contributes to the industrialization of biomass‐derived CAC electrocatalysis and electric energy storage.
Targeting the MCP‐GPX4/HMGB1 Axis for Effectively Triggering Immunogenic Ferroptosis in Pancreatic Ductal Adenocarcinoma
Authors: Li Ge , Liao Chengyu , Chen Jiangzhi , Wang Zuwei , Zhu Shuncang , Lai Jianlin , Li Qiaowei , Chen Yinhao , Wu Dihan , Li Jianbo , Huang Yi , Tian Yifeng , Chen Yanling , Chen Shi
Published: April 2024

Induction of ferroptosis can inhibit cancer cells in vitro, however, the role of ferroptosis in treatment in vivo is controversial. The immunosuppressive cells activated by the ferroptotic tumor cells can promote the growth of residual tumor cells, hindering the application of ferroptosis stimulation in tumor treatment. In this study, a new strategy is aimed to be identified for effectively triggering immunogenic ferroptosis in pancreatic ductal adenocarcinoma (PDAC) and simultaneously stimulating antitumor immune responses. Toward this, several molecular and biochemical experiments are performed using patient‐derived organoid models and a KPC mouse model (LSL‐KrasG12D/+, LSL‐Trp53R172H/+, Pdx‐1‐Cre). It is observed that the inhibition of macrophage‐capping protein (MCP) suppressed the ubiquitin fold modifier (UFM)ylation of pirin (PIR), a newly identified substrate of UFM1, thereby decreasing the transcription of GPX4, a marker of ferroptosis, and promoting the cytoplasmic transportation of HMGB1, a damage‐associated molecular pattern. GPX4 deficiency triggered ferroptosis, and the pre‐accumulated cytosolic HMGB1 is released rapidly. This altered release pattern of HMGB1 facilitated the pro‐inflammatory M1‐like polarization of macrophages. Thus, therapeutic inhibition of MCP yielded dual antitumor effects by stimulating ferroptosis and activating antitumor pro‐inflammatory M1‐like macrophages. The nanosystem developed for specifically silencing MCP is a promising tool for treating PDAC.
Integrative Single Cell Atlas Revealed Intratumoral Heterogeneity Generation from an Adaptive Epigenetic Cell State in Human Bladder Urothelial Carcinoma
Authors: Xiao Yu , Jin Wan , Qian Kaiyu , Ju Lingao , Wang Gang , Wu Kai , Cao Rui , Chang Luyuan , Xu Zilin , Luo Jun , Shan Liuying , Yu Fang , Chen Xintong , Liu Dongmei , Cao Hong , Wang Yejinpeng , Cao Xinyue , Zhou Wei , Cui Diansheng , Tian Ye , Ji Chundong , Luo Yongwen , Hong Xin , Chen Fangjin , Peng Minsheng , Zhang Yi , Wang Xinghuan
Published: April 2024

Intratumor heterogeneity (ITH) of bladder cancer (BLCA) contributes to therapy resistance and immune evasion affecting clinical prognosis. The molecular and cellular mechanisms contributing to BLCA ITH generation remain elusive. It is found that a TM4SF1‐positive cancer subpopulation (TPCS) can generate ITH in BLCA, evidenced by integrative single cell atlas analysis. Extensive profiling of the epigenome and transcriptome of all stages of BLCA revealed their evolutionary trajectories. Distinct ancestor cells gave rise to low‐grade noninvasive and high‐grade invasive BLCA. Epigenome reprograming led to transcriptional heterogeneity in BLCA. During early oncogenesis, epithelial‐to‐mesenchymal transition generated TPCS. TPCS has stem‐cell‐like properties and exhibited transcriptional plasticity, priming the development of transcriptionally heterogeneous descendent cell lineages. Moreover, TPCS prevalence in tumor is associated with advanced stage cancer and poor prognosis. The results of this study suggested that bladder cancer interacts with its environment by acquiring a stem cell‐like epigenomic landscape, which might generate ITH without additional genetic diversification.
Inflammation‐Targeted Nanomedicines Alleviate Oxidative Stress and Reprogram Macrophages Polarization for Myocardial Infarction Treatment
Authors: Hu Danrong , Li Ran , Li Yicong , Wang Meng , Wang Lu , Wang Shiqi , Cheng Hongxin , Zhang Qing , Fu Chenying , Qian Zhiyong , Wei Quan
Published: April 2024

Myocardial infarction (MI) is a critical global health challenge, with current treatments limited by the complex MI microenvironment, particularly the excessive oxidative stress and intense inflammatory responses that exacerbate cardiac dysfunction and MI progression. Herein, a mannan‐based nanomedicine, Que@MOF/Man, is developed to target the inflammatory infarcted heart and deliver the antioxidative and anti‐inflammatory agent quercetin (Que), thereby facilitating a beneficial myocardial microenvironment for cardiac repair. The presence of mannan on the nanoparticle surface enables selective internalization by macrophages rather than cardiomyocytes. Que@MOF/Man effectively neutralizes reactive oxygen species in macrophages to reduce oxidative stress and promote their differentiation into a reparative phenotype, reconciling the inflammatory response and enhancing cardiomyocyte survival through intercellular communication. Owing to the recruitment of macrophages into inflamed myocardium post‐MI, in vivo, administration of Que@MOF/Man in MI rats revealed the specific distribution into the injured myocardium compared to free Que. Furthermore, Que@MOF/Man exhibited favorable results in resolving inflammation and protecting cardiomyocytes, thereby preventing further myocardial remodeling and improving cardiac function in MI rats. These findings collectively validate the rational design of an inflammation‐targeted delivery strategy to mitigate oxidative stress and modulate the inflammation response in the injured heart, presenting a therapeutic avenue for MI treatment.