Ultrafast fiber lasers have significant applications in ultra-precision manufacturing, medical diagnostics, medical treatment, precision measurement and astronomical detection, owing to their ...ultra-short pulse width and ultra-high peak-power. Since graphene was first explored as an optical saturable absorber for passively mode-locked lasers in 2009, many other 2D materials beyond graphene, including phosphorene, antimonene, bismuthene, transition metal dichalcogenides (TMDs), topological insulators (TIs), metal-organic frameworks (MOFs) and MXenes, have been successively explored, resulting in rapid development of novel 2D materials-based saturable absorbers. Herein, we review the latest progress of the emerging 2D materials beyond graphene for passively mode-locked fiber laser application. These 2D materials are classified into mono-elemental, dual-elemental and multi-elemental 2D materials. The atomic structure, band structure, nonlinear optical properties, and preparation methods of 2D materials are summarized. Diverse integration strategies for applying 2D materials into fiber laser systems are introduced, and the mode-locking performance of the 2D materials-based fiber lasers working at 1-3 μm are discussed. Finally, the perspectives and challenges facing 2D materials-based mode-locked fiber lasers are highlighted.
The latest progress of emerging 2D materials applied in ultrafast fiber lasers is summarized, and perspectives and challenges are discussed.
Ferroelectric materials have a variety of technological applications, as transducers, capacitors, sensors, etc. Great interest in molecular ferroelectrics has emerged because of their structural ...flexibility, tunability, and homochirality. However, the discoveries of molecular ferroelectrics are not abundant. The lack of chemical design is the main challenge in realizing new molecular ferroelectrics. Consequently, chemical design approaches, including the ideas of introducing quasi-spherical theory, homochirality, and H/F substitution, have been developed recently. Through these advanced methodologies, a wide range of ferroelectrics were successfully synthesized, changing the blind search into a targeted chemical design. In this Perspective, we aim to provide insight into the fundamental chemistry and physics of molecular ferroelectrics and propose the concept of “ferroelectrochemistry”, concerned with the targeted design and performance optimization of molecular ferroelectrics from the chemical point of view. We start with the basic theories used in the modification of chemical structures for new molecular ferroelectrics, such as the quasi-spherical theory. After that, we focus on the fundamentals of homochirality from the perspective of chemistry and advantages of introducing a homochiral molecule within the scope of ferroelectrics. Further, we explore another design strategy, H/F substitution, as an analogue of the H/D isotope effect. The introduction of a F atom usually does not change the polar point group but may induce a minor structural disruption that enhances physical properties such as Curie temperature and spontaneous polarization. We hope our comprehensive studies on the targeted design and performance optimization strategies for molecular ferroelectrics may build up and enrich the content of ferroelectrochemistry.
Black phosphorus (BP) has increasingly attracted scientific attention since its first applications in biomedicine due to its unique properties and excellent biocompatibility. In particular, its ...layer‐dependent bandgap, moderate carrier mobility, large surface‐area‐to‐volume ratio, biodegradability, intrinsic photoacoustic properties, and biocompatibility make it an ideal candidate for use in photothermal therapy, photodynamic therapy, drug delivery, 3D printing, bioimaging, biosensing, and theranostics, which are reviewed here. In addition, the article discusses strategies to overcome challenges related to surface instability due to chemical degradation, a major obstacle for its application. This review not only provides a comprehensive summary on BP preparation and biomedical applications but also summarizes recent research and future possibilities.
2D black phosphorus is extensively used in biomedicine due to its excellent physical and chemical properties. This review focuses on the current progress and future perspectives of 2D black phosphorus–based biomedical applications, including cancer therapy, diagnosis, and theranostics. In addition, the article discusses strategies to overcome challenges related to surface instability, a major obstacle for its application.
To date, considerable knowledge gaps remain regarding the chest CT imaging features of coronavirus disease 2019 (COVID-19). We performed a systematic review and meta-analysis of results from ...published studies to date to provide a summary of evidence on detection of COVID-19 by chest CT and the expected CT imaging manifestations.
Studies were identified by searching PubMed database for articles published between December 2019 and February 2020. Pooled CT positive rate of COVID-19 and pooled incidence of CT imaging findings were estimated using a random-effect model.
A total of 13 studies met inclusion criteria. The pooled positive rate of the CT imaging was 89.76% and 90.35% when only including thin-section chest CT. Typical CT signs were ground glass opacities (83.31%), ground glass opacities with mixed consolidation (58.42%), adjacent pleura thickening (52.46%), interlobular septal thickening (48.46%), and air bronchograms (46.46%). Other CT signs included crazy paving pattern (14.81%), pleural effusion (5.88%), bronchiectasis (5.42%), pericardial effusion (4.55%), and lymphadenopathy (3.38%). The most anatomic distributions were bilateral lung infection (78.2%) and peripheral distribution (76.95%). The incidences were highest in the right lower lobe (87.21%), left lower lobe (81.41%), and bilateral lower lobes (65.22%). The right upper lobe (65.22%), right middle lobe (54.95%), and left upper lobe (69.43%) were also commonly involved. The incidence of bilateral upper lobes was 60.87%. A considerable proportion of patients had three or more lobes involved (70.81%).
The detection of COVID-19 chest CT imaging is very high among symptomatic individuals at high risk, especially using thin-section chest CT. The most common CT features in patients affected by COVID-19 included ground glass opacities and consolidation involving the bilateral lungs in a peripheral distribution.
The endoplasmic reticulum (ER) is an important organelle involved in cellular homeostasis and control of protein quality. Unfolded protein response (UPR) is a cellular response to ER stress and ...promotes cell survival. Severe or prolonged stress activates apoptosis signaling to trigger cell death. In mammals, the UPR is initiated by three major ER stress sensors, including inositol-requiring transmembrane kinase 1, double-stranded RNA-activated protein kinase-like ER kinase and activating transcription factor 6. UPR dysfunction plays an important role in the pathogenesis of neurodegenerative diseases including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and Huntington’s disease, which is characterized by the accumulation and aggregation of misfolded proteins. ER stress mediates the pathogenesis of psychiatric diseases, such as depression, schizophrenia, sleep fragmentation and post-traumatic stress disorder. The role of UPR in the neuropathology of humans, cell lines and animal models, is established. Therefore, inhibition of specific ER mediators may contribute to the treatment and prevention of neurodegeneration. Preclinical studies have shed light on the potential therapeutic strategies. Here, we will review the evidence of UPR activation in neurodegenerative disorders and psychiatric diseases along with the methodology.
The formation of new blood vessels, known as angiogenesis, significantly impacts the development of multiple types of cancer. Consequently, researchers have focused on targeting this process to ...prevent and treat numerous disorders. However, most existing anti-angiogenic treatments rely on synthetic compounds and humanized monoclonal antibodies, often expensive or toxic, restricting patient access to these therapies. Hence, the pursuit of discovering new, affordable, less toxic, and efficient anti-angiogenic compounds is imperative. Numerous studies propose that natural plant-derived products exhibit these sought-after characteristics. The objective of this review is to delve into the anti-angiogenic properties exhibited by naturally derived flavonoids from plants, along with their underlying molecular mechanisms of action. Additionally, we summarize the structure, classification, and the relationship between flavonoids with their signaling pathways in plants as anti-angiogenic agents, including main HIF-1α/VEGF/VEGFR2/PI3K/AKT, Wnt/β-catenin, JNK1/STAT3, and MAPK/AP-1 pathways. Nonetheless, further research and innovative approaches are required to enhance their bioavailability for clinical application.
2D phosphorene, arsenene, antimonene, and bismuthene, as a fast‐growing family of 2D monoelemental materials, have attracted enormous interest in the scientific community owing to their intriguing ...structures and extraordinary electronic properties. Tuning the monoelemental crystals into bielemental ones between group‐VA elements is able to preserve their advantages of unique structures, modulate their properties, and further expand their multifunctional applications. Herein, a review of the historical work is provided for both theoretical predictions and experimental advances of 2D V‐V binary materials. Their various intriguing electronic properties are discussed, including band structure, carrier mobility, Rashba effect, and topological state. An emphasis is also given to their progress in fabricated approaches and potential applications. Finally, a detailed presentation on the opportunities and challenges in the future development of 2D V‐V binary materials is given.
2D V‐V binary materials, as the internal combination of group‐VA elements (N, P, As, Sb, Bi), have become a popular research topic. Through the interaction among charge, orbital, lattice, and spin degrees of freedom, the favorable and superior properties in 2D V‐V binary materials can be further modulated, extending their application in novel electronic, optoelectronic, and energy devices.
3D ABX3 organic–inorganic halide perovskite (OIHP) semiconductors like CH3NH3PbI3 have received great attention because of their various properties for wide applications. However, although a number ...of low‐dimensional lead‐based OIHP ferroelectric semiconductors have been documented, obtaining 3D ABX3 OIHP ferroelectric semiconductors is challenging. Herein, an A‐site cation CH3PH3+ (methylphosphonium, MP) is employed to successfully obtain a lead‐free 3D ABX3 OIHP ferroelectric semiconductor MPSnBr3, which shows clear above‐room‐temperature ferroelectricity and a direct bandgap of 2.62 eV. It is emphasized that MPSnBr3 is a multiaxial molecular ferroelectric with the number of ferroelectric polar axes being as many as 12, which is far more than those of the other OIHP ferroelectric semiconductors and even the classical inorganic perovskite ferroelectric semiconductors BiFeO3 (4 polar axes) and BaTiO3 (3 polar axes). MPSnBr3 is the first MP‐based 3D ABX3 OIHP ferroelectric semiconductor. This finding throws light on the exploration of other excellent 3D ABX3 OIHP ferroelectric semiconductors with great application prospects.
MPSnBr3 (MP = methylphosphonium) is the first MP‐based 3D ABX3 hybrid perovskite ferroelectric semiconductor. MPSnBr3 is lead‐free and shows clear ferroelectricity with the number of ferroelectric polar axes up to 12, much more than that of other hybrid perovskite ferroelectric semiconductors. MPSnBr3 also exhibits a direct bandgap of 2.62 eV.
Based on the chiral kinetic equations of motion, spin polarizations of various quarks, due to the magnetic field induced by spectator protons as well as the quark-antiquark vector interaction, are ...studied within a partonic transport approach. Although the magnetic field in QGP enhances the splitting of the spin polarizations of partons compared to the results under the magnetic field in vacuum, the spin polarizations of s and s¯ quarks are also sensitive to the quark-antiquark vector interaction, challenging that the different Λ and Λ¯ spin polarization is a good measure of the magnetic field in relativistic heavy-ion collisions. It is also found that there is no way to obtain the large splitting of the spin polarization between Λ and Λ¯ at sNN=7.7 GeV with partonic dynamics.
Solution processing of colloidal MXenes is reviewed, focusing on the fundamentals from MXene ink formulation to processed thin films/structures/devices. Colloidal and rheological properties of MXene ...inks, including wettability, drying kinetics, adhesion and film formation, which are highly crucial for the high-resolution printing and high-quality, homogeneous coating, are discussed in detail. A map of guidelines for solution processing of colloidal MXenes is provided.
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Since the discovery of two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, research on these wonder 2D inorganic compounds has become increasingly intensified with their members quickly expanding. MXenes' state-of-the-art applications are heavily dependent on their processing strategies and manufacturing methods. Nevertheless, the solution processing of MXenes has not been comprehensively reviewed. This review summarizes progress regarding solution processing of MXenes over the past decade as well as outlines key perspectives for future scalable manufacturing strategies. Etching of MAX phases and delamination of MXene are briefly introduced. Rheological properties of MXene dispersions and wetting of the MXene inks, which are crucial for the achievement of high-resolution printing and homogeneous coating, are discussed in detail. We have discussed the ink formulation strategies and fine-tuning of the ink properties to match with that of the targeted substrates to yield efficient yet high-quality printed/coated films/structures. As such, we demonstrate a “map of guidelines” for solution-based processing of MXenes toward high-performance applications, such as electrochemical energy storage, conductive electrodes, electromagnetic interference shielding, and so on.
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