Hot Research Trends Research Articles

Room temperature deprotonation engineering for large-scale preparation of MIL-88B-like for efficient electromagnetic wave absorption

Metal-organic frameworks (MOFs)-derived electromagnetic functional materials are a hot research trend in the field of microwave absorption (MA). However, there is a lack of high-yield strategies to drive high-performance MOFs-derived MA absorbers out of the laboratory. Herein, we prepared MIL-88B-like using a simple room-temperature liquid-phase method with more than 75 times the yield of the solvothermal method. The obtained MOFs were pyrolyzed to form C/FeO/FeN0.0324/Fe quaternary composite materials. Under suitable graphitizing conditions, the moderate conductivity of derivative material of M1 precursor carbonized at 700 °C (M1-700) not only meets the requirement of impedance matching but also provides high conduction loss. Meanwhile, the multiple polarization loss mechanisms from defect-induced polarization, dipole polarization, heterogeneous interfaces, and magnetic loss mechanism synergize with each other, resulting in an effective absorption bandwidth (EAB) of 6.71 GHz and a reflection loss (RL) value of −62.57 dB at 22.5 wt% filler, which is a 6-fold increase in the RL compared with that of the conventional MIL-88B-derived wave absorber. In conclusion, this work provides a feasible solution for practical absorbers and an excellent reference value for high MA performance materials for applications.

Synthetic receptor scaffolds significantly affect the efficiency of cell fate signals

Mimicry of receptor functions by designing synthetic receptors would be one of the recently hot research trends in cell engineering. While several types of synthetic receptors have been designed to induce desired cell fates in response to external stimuli, little is known about which receptor type signals more efficiently for inducing a certain cell fate. In this study, we compared the performance of three types of synthetic receptor scaffolds, i.e. myristoylated, cytosolic, and transmembrane types that signal through JAK-dependent phosphorylation of tyrosine motifs to transduce growth signaling. As a result, the phosphorylation levels of JAK and subsequent downstream signaling molecules were significantly maintained in the cytosolic type receptors, leading to more efficient cell growth than the other types. In contrast, the phosphorylation levels of JAK decreased in a motif-dependent manner in the transmembrane type receptors. Although various studies on receptor engineering based on domain or motif engineering have been reported, to our knowledge this study is the first to demonstrate that synthetic receptor scaffolds significantly affect the efficiency of cell fate signals. These findings are important for both receptor biology and receptor engineering, providing guidelines for rationally designing synthetic receptors that can transduce as efficient signaling as possible.

The Global Situation of Karst Desertification Research Based on Forest Ecology

Karst desertification (KD) is a major ecological and environmental problem threatening human survival and development in karst areas. In order to explore the research situation and development trend of KD based on forest ecology, this paper provides a systematic literature review based on the CNKI and WoS databases, which involves search, appraisal, synthesis, and analysis. We performed a statistical and visual analysis of 2955 studies acquired between 1 January 1995 and 30 June 2023, including the time distribution of the studies, hot research trends, pivotal research clusters, literature co-citations, main publishing trends, and keyword bursts. The results show the following. (1) The literature shows a fluctuating growth trend, and the research trends are divided into accumulation, development, and expansion stages. (2) The pivotal research clusters comprised three major aspects: study area and method, driving and genetic mechanisms, and control technology and models. (3) KD research forms a China-centered research network, dominated by institutions and scholars in southwestern China. (4) Future research needs to solve a series of related scientific issues and technological needs for forest ecosystem function optimization, ecological product supply capacity enhancement, ecological product value realization, ecological industry formation, and rural revitalization in KD control. The purpose of this paper is to reveal research trends relating to KD and highlight the future direction of KD research and control.

Molecular Dynamics Simulation Study on Thermal Transport in Graphyne/Polyaniline Composite System

AbstractGraphyne (GY) is a new carbon material with excellent electrical conductivity and low thermal conductivity (TC). The doping of GY into polymers to improve the thermoelectric properties of the material has become a hot research trend. In this study, molecular dynamics (MD) and nonequilibrium MD are used to study the effect of the number of oxidation units of polyaniline (PANI) on TC and heat transfer of PANI and GY/PANI systems. The geometric structure of polymer, interaction energy, and heat transport of all systems are studied and analyzed. It is found that (1) as the number of oxidation units of PANI increases, the interchain and intrachain heat transfers of PANI are decreased thereby decreasing the heat transfer of the PANI chains; (2) the weak interaction energy at the interface hinders the heat flux transfer, and the phonon vibration of GY and PANI mismatch at the interfaces; eventually the above reasons lead to low interface TC; (3) the doping of GY can effectively reduce the TC of the system. This study provides some research ideas and theoretical exploration for the application of polymer doped with GY composites in the field of thermoelectricity.

Dynamic Development Analysis of Complex Network Research: A Bibliometric Analysis

In recent years, the method of the complex network has been applied to various fields. Dynamics research in complex networks is also an important branch. There are many types of research into dynamic complex network, but few scholars use bibliometrics to study it. Therefore, this paper adopts the method of bibliometrics to analyze the development history and status quo of dynamic complex network, providing a summary description of this research field. We used CiteSpace and Pajek to analyze 2936 relevant papers on the website of Web of Science and further interpreted and summarized the analysis results. To fully show the bibliometric results, we further derive the productive countries, institutions, sources, and authors and some main research directions in the dynamic complex network research. The research results show that the dynamic complex network research method was applied to various fields after the dynamic research method had been integrated into the complex network. According to the subject analysis of the cited papers, we find that the dynamic complex network method has been widely used in various subjects. Through emergent analysis, we found that the latest hot research trends are the study of infectious diseases and applications in neural networks. At the same time, through the main path analysis, we find the essential literature to elaborate on the development context of a dynamic complex network at different time points. This paper gives a comprehensive analysis of dynamic complex network research and provides some enlightenment for the future research direction.

Mapping the Field in Stress, Anxiety, and Postpartum Depression in Mothers of Preterm Infants in Neonatal Intensive Care.

Objective: The main aim of this study was to describe and conduct a bibliometric analysis of the state of research on stress, anxiety, and postpartum depression in mothers of preterm infants in the Neonatal Intensive Care Unit. Background: Women affected by premature births are particularly exposed to mental health difficulties in the postpartum period. The desire to comprehend and the growing interest in research on stress, anxiety, and postpartum depression in mothers of preterm infants in neonatal intensive care have led to a substantial rise in the number of documents in this field over the last years. Thus, it makes it vital to regularly review the state of knowledge on this phenomenon in order to identify progress and constraints, to stimulate reflection, and to encourage progress in future research. Method: This study examined 366 articles published in the Scopus database (1976–2020). Keyword analysis was also used to identify hot research trends to be developed in future studies. This study complies with the PRISMA-Scr guidelines for quality improvement research in the EQUATOR network. Results: Our results reveal that research in this field is in a period of high production and allows this flourishing body of work to be organized into different periods, highlighting the most important themes. In such a way, our research enriches the lively field by presenting a comprehensive understanding of the field. Discussion: The key contribution of this study is the development of a conceptual map of research on stress, anxiety, and postpartum depression in mothers of preterm infants in neonatal intensive care units.

UAV Communications for Sustainable Federated Learning

Federated learning (FL), invented by Google in 2016, has become a hot research trend. However, enabling FL in wireless networks has to overcome the limited battery challenge of mobile users. In this regard, we propose to apply unmanned aerial vehicle (UAV)-empowered wireless power transfer to enable sustainable FL-based wireless networks. The objective is to maximize the UAV transmit power efficiency, via a joint optimization of transmission time and bandwidth allocation, power control, and the UAV placement. Directly solving the formulated problem is challenging, due to the coupling of variables. Hence, we leverage the decomposition technique and a successive convex approximation approach to develop an efficient algorithm, namely UAV for sustainable FL (UAV-SFL). Finally, simulations illustrate the potential of our proposed UAV-SFL approach in providing a sustainable solution for FL-based wireless networks, and in reducing the UAV transmit power by 32.95%, 63.18%, and 78.81% compared with the benchmarks.

2D metal-organic framework-based materials for electrocatalytic, photocatalytic and thermocatalytic applications.

Ultrathin two-dimensional metal-organic frameworks (2D MOFs) have recently attracted extensive interest in various catalytic fields (e.g., electrocatalysis, photocatalysis, thermocatalysis) due to their ultrathin thickness, large surface area, abundant accessible unsaturated active sites and tunable surface properties. Besides tuning the intrinsic properties of pristine 2D MOFs by changing the metal nodes and organic ligands, one of the hot research trends is to develop 2D MOF hybrids and 2D MOF-derived materials with higher stability and conductivity in order to further increase their activity and durability. Here, the synthesis of 2D MOF nanosheets is briefly summarized and discussed. More attention is focused on summaries and discussions about the applications of these 2D MOFs, their hybrids and their derived materials as electrocatalysts, photocatalysts and thermocatalysts. The superior properties and catalytic performance of these 2D MOF-based catalysts compared to their 3D MOF counterparts in electrocatalysis, photocatalysis and thermocatalysis are highlighted. The enhanced activities of 2D MOFs, their hybrids and derivatives come from abundant accessible active sites, a high density of unsaturated metal nodes, ultrathin thickness, and tunable microenvironments around the MOFs. Views regarding current and future challenges in the field, and new advances in science and technology to meet these challenges, are also presented. Finally, conclusions and outlooks in this field are provided.

Strain modulation of phase transformation of noble metal nanomaterials

AbstractNoble metals have been extensively studied owing to their high chemical stability and outstanding catalytic properties in various important reactions. However, their large‐scale application of noble metals is still challenged by their high expense and scarcity on the earth, as well as the yet insufficient activity to give a satisfying performance. For decades, enormous research efforts have been devoted to the nanoengineering of noble metal nanocrystals, such as the size‐, composition‐, shape‐, and/or morphology‐controlled syntheses, and impressive advances have been achieved. Meanwhile, the discovery that the crystal structure of noble metal nanocrystals also has a significant impact on their properties opened a new pathway that modulates the crystal phases of noble metals to achieve better properties. Among the feasible methods for crystal phase transformation, the presence of strain is not negligible. Strain generally has two roles: the driving force of the phase transformation and/or the origin of the distinct properties of the new crystal structure. Strain effect on noble metals has also been extensively studied due to its capability of fine‐tuning the surface catalytic activity. Therefore, combining the two hot research trends together, a possible research pathway is emerging. That is, utilizing the potential synergistic effect between novel crystal phases and the subsequent lattice strain to boost the performance of noble metal nanocrystal even further. Herein, a brief summary of the currently discovered noble metal phases and strain effect and the introduction of strain related phase modulation techniques along with the catalytic applications will be presented. Finally, a brief conclusion and future perspective is given.image

Reinforcing materials for polymeric tissue engineering scaffolds: A review.

Final purpose of tissue engineering is to regenerate or repair damaged tissues or organs. Desired repair efficacy necessitates proper physicochemical performances of scaffolds, among which adequate mechanical properties are crucial. Therefore, reinforcing tissue engineering scaffolds has been a hot research trend in recent years. In this regard, the use of some biomaterials as reinforcing materials is a longstanding area of interest. This article introduces the most popular reinforcing materials and focuses on recent advances in the use of these materials for reinforcing mechanical properties of tissue engineering scaffolds. A classification based on materials nature, for example, bioceramics, clays, carbon-based materials, and metal oxides, is provided, followed by their effects on scaffolds properties. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1560-1575, 2019.

Blockchain Security in Cloud Computing: Use Cases, Challenges, and Solutions

Blockchain has drawn attention as the next-generation financial technology due to its security that suits the informatization era. In particular, it provides security through the authentication of peers that share virtual cash, encryption, and the generation of hash value. According to the global financial industry, the market for security-based blockchain technology is expected to grow to about USD 20 billion by 2020. In addition, blockchain can be applied beyond the Internet of Things (IoT) environment; its applications are expected to expand. Cloud computing has been dramatically adopted in all IT environments for its efficiency and availability. In this paper, we discuss the concept of blockchain technology and its hot research trends. In addition, we will study how to adapt blockchain security to cloud computing and its secure solutions in detail.

Development of a portable non-invasive swallowing and respiration assessment device.

Dysphagia is a condition that happens when a person cannot smoothly swallow food from the mouth to the stomach. It causes malnourishment in patients, or can even cause death due to aspiration pneumonia. Recently, more and more researchers have focused their attention on the importance of swallowing and respiration coordination, and the use of non-invasive assessment systems has become a hot research trend. In this study, we aimed to integrate the timing and pattern monitoring of respiration and swallowing by using a portable and non-invasive approach which can be applied at the bedside in hospitals or institutions, or in a home environment. In this approach, we use a force sensing resistor (FSR) to detect the motions of the thyroid cartilage in the pharyngeal phase. We also use the surface electromyography (sEMG) to detect the contraction of the submental muscle in the oral phase, and a nasal cannula to detect nasal airflow for respiration monitoring during the swallowing process. All signals are received and processed for swallowing event recognition. A total of 19 volunteers participated in the testing and over 57 measurements were made. The results show that the proposed approach can effectively distinguish the swallowing function in people of different ages and genders.