COVID-19 was declared a pandemic on March 11 by WHO, due to its great threat to global public health. The coronavirus main protease (M
, also called 3CLpro) is essential for processing and maturation ...of the viral polyprotein, therefore recognized as an attractive drug target. Here we show that a clinically approved anti-HCV drug, Boceprevir, and a pre-clinical inhibitor against feline infectious peritonitis (corona) virus (FIPV), GC376, both efficaciously inhibit SARS-CoV-2 in Vero cells by targeting M
. Moreover, combined application of GC376 with Remdesivir, a nucleotide analogue that inhibits viral RNA dependent RNA polymerase (RdRp), results in sterilizing additive effect. Further structural analysis reveals binding of both inhibitors to the catalytically active side of SARS-CoV-2 protease M
as main mechanism of inhibition. Our findings may provide critical information for the optimization and design of more potent inhibitors against the emerging SARS-CoV-2 virus.
The development of advanced microelectronics requires new device architecture and multi‐functionality. Low‐dimensional material is considered as a powerful candidate to construct new devices. In this ...work, a flexible memristor is fabricated utilizing 2D cadmium phosphorus trichalcogenide nanosheets as the functional layer. The memristor exhibits excellent resistive switching performance under different radius and over 103 bending times. The device mechanism is systematically investigated, and the synaptic plasticity including paired‐pulse facilitation and spiking timing‐dependent plasticity are further observed. Furthermore, based on the linearly conductance modulation capacity of the flexible memristor, the applications on decimal operation are explored, that the addition, subtraction, multiplication, and division of decimal calculation are successfully achieved. These results demonstrate the potential of metal phosphorus trichalcogenide in novel flexible neuromorphic devices, which accelerate the application process of neuromorphic computing.
A flexible memristor constructed by 2D cadmium phosphorus trichalcogenide nanosheets emerges with excellent resistive switching characteristics. Essential synaptic plasticities can be successfully mimicked. The applications on decimal operation including the addition, subtraction, multiplication, and division of decimal operation are successfully explored, which demonstrates the promising prospect in artificial electronic synapses of CdPS3‐based memristor.
A new solar energy storage system is designed and synthesized based on phase‐changing microcapsules incorporated with black phosphorus sheets (BPs). BPs are 2D materials with broad light absorption ...and high photothermal performance, which are synthesized and covalently modified with poly(methyl methacrylate) (PMMA) to produce the PMMA‐modified BPs (mBPs). With the aid of PMMA, the mBPs and phase‐changing materials (PCM, eicosane) are encapsulated together to form microcapsules. The microencapsulated eicosane and mBPs (mBPs‐MPCM) composites exhibit a high latent heat of over 180 kJ kg−1, good thermal reliability, as well as excellent photothermal characteristics inherited from BPs. Owing to the direct contact in the integrated mBPs‐MPCM composites, the thermal energy generated by mBPs is transferred to eicosane immediately giving rise to three times higher efficiency in solar energy storage compared to microcapsules with mBPs on the surface. The mBPs‐MPCM composites have great potential in solar energy storage applications and the concept of integrating photothermal materials and PCMs as the core provides insights into the design of high‐efficiency solar energy storage materials.
Phase‐changing microcapsules incorporated with black phosphorus are designed and prepared for efficient solar energy storage. Because of the direct contact between the black phosphorus sheets and eicosane, the microencapsulated composites show reduced energy loss during solar‐thermal energy transfer and accelerated solar energy storage. This structure has large potential in high‐efficiency solar energy storage.
The aim of the study was to determine the prevalence and clinical associations of antiphosphatidylserine/prothrombin antibodies (aPS/PT) with thrombosis and pregnancy loss in Chinese patients with ...antiphospholipid syndrome (APS) and seronegative APS (SNAPS).
One hundred and eighty six Chinese patients with APS (67 primary, 119 secondary), 48 with SNAPS, 176 disease controls (79 systemic lupus erythematosus SLE, 29 Sjogren's syndrome SS, 30 ankylosing spondylitis AS, 38 rheumatoid arthritis RA) and 90 healthy donors were examined. IgG and IgM aPS/PT, IgG/IgM/IgA anticardiolipin (aCL) and IgG/IgM/IgA anti-β2-glycoprotein I (anti-β2GPI) antibodies were tested by ELISA.
One hundred and sixty (86.0%) of APS patients were positive for at least one aPS/PT isotype. One hundred and thirty five (72.6%) were positive for IgG aPS/PT, 124/186 (66.7%) positive for IgM aPS/PT and 99 (53.2%) positive for both. Approximately half of the SNAPS patients were positive for IgG and/or IgM aPS/PT. Highly significant associations between IgG aPS/PT and venous thrombotic events (odds ratio OR=6.72) and IgG/IgM aPS/PT and pregnancy loss (OR=9.44) were found. Levels of IgM aPS/PT were significantly different in APS patients with thrombotic manifestations and those with fetal loss (p=0.014). The association between IgG/IgM aPS/PT and lupus anticoagulant (LAC) was highly significant (p<0.001). When both were positive, the OR for APS was 101.6. Notably, 91.95% (80/87) of LAC-positive specimens were positive for IgG and/or IgM aPS/PT, suggesting aPS/PT is an effective option when LAC testing is not available.
Anti-PS/PT antibody assays demonstrated high diagnostic performance for Chinese patients with APS, detected some APS patients negative for criteria markers and may serve as potential risk predictors for venous thrombosis and obstetric complications.
Two dimensional (2D) nanoribbons constitute an emerging nanoarchitecture for advanced microelectronics and energy conversion due to the stronger size confinement effects compared to traditional ...nanosheets. Triclinic crystalline red phosphorus (cRP) composed by a layered structure is a promising 2D phosphorus allotrope and the tube‐like substructure is beneficial to the construction of nanoribbons. In this work, few‐layer cRP nanoribbons are synthesized and the effectiveness in the electrochemical nitrogen reduction reaction (NRR) is investigated. An iodine‐assisted chemical vapor transport (CVT) method is developed to synthesize circa 10 g of bulk cRP lumps with a yield of over 99 %. With the aid of probe ultrasonic treatment, high‐quality cRP microcrystals are exfoliated into few‐layer nanoribbons (cRP NRs) with large aspect ratios. As non‐metallic materials, cRP NRs are suitable for the electrochemical nitrogen reduction reaction. The ammonia yield is 15.4 μg h−1 mgcat.−1 at −0.4 V vs. reversible hydrogen electrode in a neutral electrolyte under ambient conditions and the Faradaic efficiency is 9.4 % at −0.2 V. Not only is cRP a promising catalyst, but also the novel strategy expands the application of phosphorus‐based 2D structures beyond that of traditional nanosheets.
Crystalline red phosphorus (cRP) with a layered structure are synthesized on a large scale by an efficient chemical vapor transport method and few‐layer 2D nanoribbons are exfoliated. Theoretical and experimental studies demonstrate that the cRP nanoribbons are promising in electrochemical nitrogen reduction in aqueous solutions under ambient conditions.
A transmitarray antenna (TAA) with a small-scale circular phased array antenna (PAA) feed is proposed in this article to generate orbital angular momentum (OAM)-carrying radio beams. After analyzing ...the operating mechanisms of the OAM-generating PAA-fed TAA, its numerical model is further developed to determine the TAA element arrangement and the PAA feed excitation coefficients. Furthermore, a three-layer element with polarization-conversion property and the traditional patch antenna element are identified as the elements of the TAA and PAA feed, respectively. Benefiting from the intrinsic multibeam capabilities of the TAA, the steering of the zero-OAM-mode beam is firstly discussed, where a conical scanning across an angular range of ±25° is realized. Meanwhile, the creation of multiple pure or mixed OAM beams with helical phase fronts is also presented, where the superposition of multiple OAM states provides more possibilities to increase the channel capacity and spectrum efficiency. To facilitate the experiments, an <inline-formula> <tex-math notation="LaTeX">8\times 8 </tex-math></inline-formula> Butler matrix with a bandwidth over 30% is designed, which integrated with the array-fed TAA also provides an attractive solution to simultaneously generate multiple OAM modes without requiring any active modules. The experimental results agree reasonably well with the numerical ones, validating the feasibility of our idea to design a high-gain OAM-generating PAA-fed TAA.
Growing evidences suggest that cancer stem cells exhibit many molecular characteristics and phenotypes similar to their ancestral progenitor cells. In the present study, human embryonic stem cells ...are induced to differentiate into hepatocytes along hepatic lineages to mimic liver development in vitro. A liver progenitor specific gene, RALY RNA binding protein like (RALYL), is identified. RALYL expression is associated with poor prognosis, poor differentiation, and metastasis in clinical HCC patients. Functional studies reveal that RALYL could promote HCC tumorigenicity, self-renewal, chemoresistance, and metastasis. Moreover, molecular mechanism studies show that RALYL could upregulate TGF-β2 mRNA stability by decreasing N6-methyladenosine (m
A) modification. TGF-β signaling and the subsequent PI3K/AKT and STAT3 pathways, upregulated by RALYL, contribute to the enhancement of HCC stemness. Collectively, RALYL is a liver progenitor specific gene and regulates HCC stemness by sustaining TGF-β2 mRNA stability. These findings may inspire precise therapeutic strategies for HCC.
A filtering transmitarray antenna (TAA) with high-gain in-band radiations at the <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula>-band and an out-of-band low-scattering ...characteristic is presented in this communication. The proposed composite TAA element consists of a dual-polarized resistive sheet, a fixed bandstop frequency-selective surface (FSS) element, and an adjustable bandpass FSS element also serving as a phase shifter. The resistive element is constructed by inserting a parallel inductor-capacitor (PLC) resonant structure into the center of a lumped-resistor-loaded metallic dipole. A transparent frequency-domain window at the center operating frequency (<inline-formula> <tex-math notation="LaTeX">f_{c} </tex-math></inline-formula>) is created by the PLC resonance and is further shared by both FSS elements, hence allowing for high in-band transmission herein. At frequencies below or above <inline-formula> <tex-math notation="LaTeX">f_{c} </tex-math></inline-formula>, the whole composite TAA element acts as an absorber with the bandpass or bandstop FSS elements as the ground planes for the resistive sheet, respectively. The measured results show that the composite TAA can achieve gain-filtering responses with out-of-band suppression levels ≥25 dB, ~8 dB scattering cross section (SCS) reductions in 4-7 and 14-20 GHz, and the radiation gain of 25.3 dBi simultaneously. Because of these merits, the proposed design can relieve the stress on filtering circuit designs, also offering an attractive solution in stealth technology.
•A composite is successfully prepared with sea-urchin-like Fe2O3 and MXene nanosheets.•The 2D Ti2C3Tx MXene nanosheets were closely self-assembled on the surface of Fe2O3.•The 2D MXene nanosheets can ...effectively improve the conductivity of Fe2O3.•The optimized Fe2O3/MXene composite showed excellent electrochemical performance for supercapacitors.
Fe2O3 is one of promising negative materials for supercapacitors (SCs), because of its low cost and high theoretical value of specific capacitance. However, the inferior conductivity and insufficient ionic diffusion rate of Fe2O3 will seriously hinder the electrochemical performance of Fe2O3, resulting in limiting its practical application in SCs. Herein, a sea urchin-like 3D Fe2O3 was synthesized via hydrothermal methods. And then, the 2D Ti2C3Tx MXene nanosheets with high conductivity closely self-assemble on the surface of Fe2O3 to provide efficient pathways for the rapid electrons transport. In addition, the sea urchin-like structure of Fe2O3 can facilitate the rapid diffusion of the electrolyte to accelerate faradaic reaction. The optimized Fe2O3/MXene composite as electrode material exhibits a high specific capacitance of 486.3 F g−1 at current density of 1 A g−1, and excellent cycling stability with 95.7% capacity retention after 5000 charge/discharge cycles. Furthermore, an asymmetric supercapacitors (ASCs) device was assembled by using Fe2O3/MXene composite as anode and MnO2 as cathode, showing a high energy density of 32.2 Wh kg−1 at the power density of 900.6 W kg−1, and remarkable long-term durability (95.7 % capacitance retention after 5000 cycles). This work demonstrates an effective approach of integrating the sea urchin-like Fe2O3 with 2D MXene nanosheets to fabricate Fe2O3/MXene composite for high-performance SCs.
Display omitted The Fe2O3/MXene composites were prepared through electrostatic self-assembly, by integrating the negatively charged 2D Ti2C3Tx MXene nanosheets with positively charged urchin-shaped Fe2O3 together. The optimized Fe2O3/MXene composite as electrode material exhibits a high specific capacitance of 486.3 F g-1 at current density of 1 A g-1, and excellent cycling stability with 95.7% capacity retention after 5000 charge/discharge cycles.
LiNi0.5‑x P2x Mn1.5‑x O4 (x = 0, 0.005, 0.01, and 0.02) submicrograins in regular octahedral shape with merely {111} surface facets and truncated octahedral shape with both {111} and {100} surface ...planes were obtained by the solid-state reaction method. The effect of doping P on ions arrangement, grain morphology, and the electrochemical performance of lithium nickel manganese oxide was investigated. The characterizations of X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), and selected area electron diffraction (SAED) confirm more Mn3+ ions in the structure to enhance the cationic disorder degree of LiNi0.5Mn1.5O4 after P-doping. Comparing the LiNi0.5Mn1.5O4 and LiNi0.495P0.01Mn1.495O4 samples both with regular octahedral morpology, their electrochemical performance could be remarkably improved by more disordered transition metal ions arrangement leading to higher conductivity of Li-ions and electrons. However, when the amount of P-doping further increased, the rate and cycle ability of the LiNi0.480P0.04Mn1.480O4 sample in truncated octahedral shape worsen dramatically even with a higher degree of cationic disorder. This could be on account of the crystal planes starting to dominate the electrochemical performance instead of ions arrangement under high voltage and large rate: the {111} facet is more favorable to the lithium ion transport than the {100} crystal plane for LiNi0.5Mn1.5O4 submicrograins during charge and discharge.
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