Abstract
In December 2019, the coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and now has spread in many countries. ...Pregnant women are a population susceptible to COVID-19 and are more likely to have complications and even progress to severe illness. We report a case of neonatal COVID-19 in China with pharyngeal swabs testing positive by real-time reverse-transcription polymerase chain reaction assay 36 hours after birth. However, whether the case is a vertical transmission from mother to child remains to be confirmed.
This article focuses on the robust fault tolerant control (FTC) problem for a class of Lipschitz nonlinear multi‐agent systems(MASs) subject to sensor faults. Firstly, sensor faults are transformed ...into actuator faults via introducing a new intermediate auxiliary state variable, and a distributed adaptive fault estimation observer is designed to estimate the state information and the concerned faults by using the relative output estimation error. Then, the sufficient existence conditions for the observer to satisfy the robust performance index are given. Thirdly, based on the results of observer design, a new design method of dynamic output feedback controller is proposed to implement consensus of MASs and ensure the desired disturbance rejection performance. Finally, the simulation results are presented to illustrate the effectiveness of the proposed method.
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•A novel FUNP analysis on QFPD function.•QFPD act on COVID-19 via anti-viral, anti-inflammatory and metabolic programming.•9 QFPD ingredients presented good molecular docking score ...for 2019-nCov.•SGMH, MXSG and Others are the top 3 efficient formula for COVID-19.
Qingfei Paidu decoction (QFPD), a multi-component herbal formula, has been widely used to treat COVID-19 in China. However, its active compounds and mechanisms of action are still unknown. Firstly, we divided QFPD into five functional units (FUs) according to the compatibility theory of traditional Chinese medicine. The corresponding common targets of the five FUs were all significantly enriched in Go Ontology (oxidoreductase activity, lipid metabolic process, homeostatic process, etc.), KEGG pathways (steroid biosynthesis, PPAR signaling pathway, adipocytokine signaling pathway, etc.), TTD diseases (chronic inflammatory diseases, asthma, chronic obstructive pulmonary Disease, etc.), miRNA (MIR183), kinase (CDK7) and TF (LXR). QFPD contained 257 specific targets in addition to HCoV, pneumonia and ACE2 co-expression proteins. Then, network topology analysis of the five components-target-pathway-disease networks yielded 67 active ingredients. In addition, ADMET estimations showed that 20 compounds passed the stringent lead-like criteria and in silico drug-likeness test with high gastrointestinal absorption and the median lethal dose (LD50 > 1600 mg/kg). Moreover, 4 specific ingredients (M3, S1, X2 and O2) and 5 common ingredients (MS1, MX16, SX1, WO1 and XO1) of QFPD presented good molecular docking score for 2019-nCov structure and non-structure proteins. Finally, drug perturbation of COVID-19 network robustness showed that all five FUs may protect COVID-19 independently, and target 8 specifically expressed drug-attacked nodes which were related to the bacterial and viral responses, immune system, signaling transduction, etc. In conclusion, our new FUNP analysis showed that QFPD had a protection effect on COVID-19 by regulating a complex molecular network with safety and efficacy. Part of the mechanism was associated with the regulation of anti-viral, anti-inflammatory activity and metabolic programming.
Polymer-fullerene bulk heterojunction solar cells (PSCs) are currently attracting a great deal of attention and gaining increasing importance, having already shown great promise as renewable, ...lightweight and low-cost energy sources. Recently, the power-conversion efficiency of state-of-the-art PSCs has exceeded 8% in the scientific literature. However, to find viable applications for this emerging photovoltaic technology, further enhancements in the efficiency towards 10% (the threshold for commercial applications) are urgently required. Here, we demonstrate highly efficient PSCs with a certified efficiency of 9.2% using an inverted structure, which simultaneously offers ohmic contact for photogenerated charge-carrier collection and allows optimum photon harvest in the device. Because of the ease of use and drastic boost in efficiency provided by this device structure, this discovery could find use in fully exploiting the potential of various material systems, and also open up new opportunities to improve PSCs with a view to achieving an efficiency of 10%.
In recent years, substantial progress has been made in developing perovskite light-emitting diodes with near-infrared, red and green emissions and over 20% external quantum efficiency. However, the ...development of perovskite light-emitting diodes with blue emission remains a great challenge, which retards further development of full-color displays and white-light illumination based on perovskite emissive materials. Here, firstly, through composition and dimensional engineering, we prepare quasi-two-dimensional perovskite thin films with improved blue emission, taking advantages of reduced trap density and enhanced photoluminescence quantum yield. Secondly, we find a vertically non-uniform distribution of perovskite crystals in the PEDOT:PSS/perovskite hybrid film. Through modulating the position of the recombination zone, we activate the majority of quasi-two-dimensional perovskite crystals, and thus demonstrate the most efficient blue perovskite light-emitting diode to date with emission peak at 480 nm, record luminance of 3780 cd m
and record external quantum efficiency of 5.7%.
Perovskite solar cells (PSCs) have been brought into sharp focus in the photovoltaic field due to their excellent performance in recent years. The power conversion efficiency (PCE) has reached to be ...25.2% in state-of-the-art PSCs due to the outstanding intrinsic properties of perovskite materials as well as progressive optimization of each functional layer, especially the active layer and hole transporting layer (HTL). In this review, we mainly discuss various hole transporting materials (HTMs) consisting of HTL in PSCs. The progress in PSCs is firstly introduced, then the roles of HTL playing in photovoltaic performance improvement of PSCs are emphasized. Finally, we generally categorize HTMs into organic and inorganic groups and demonstrate both their advantages and disadvantages. Specially, we introduce several typical organic HTMs such as P3HT, PTTA, PEDOT:PSS, spiro-OMeTAD, and inorganic HTMs such as copper-based materials (CuO
x
, CuSCN, CuI, etc.), nickel-based materials (NiO
x
), and two-dimensional layered materials (MoS
2
, WS
2
, etc.). On basis of reviewing the reported HTMs in recent years, we expect to provide some enlightenment for design and application of novel HTMs that can be used to further promote PSCs performance.
The wind field around a 1:1:2 isolated building was predicted by large-eddy simulation for evaluating the pedestrian-level wind environment. This study focused on the effects of cell types ...(hexahedral, tetrahedral and polyhedral cells) and boundary layer mesh on the time-averaged and fluctuating wind characteristics. The minimum cell size and stretching ratio were set to be the same among all cases. The case composed of hexahedral cells was found to have the best agreement with the experiment among the three cell types. The accuracies of the polyhedral cases are close to that of the hexahedral case, and better than those of the tetrahedral cases. However, the polyhedral mesh is most economical for the computational resources since the cell numbers of the polyhedral cases are less than half of that of the hexahedral case and about a quarter of those of the tetrahedral cases. It was also found that the boundary layer mesh does not improve the numerical accuracy under any circumstances. For both tetrahedral and polyhedral meshes, the boundary layer mesh can improve the numerical accuracy in the region above the flat ground by reducing the mesh non-orthogonality and skewness. However, the boundary layer mesh was found to worsen the mesh quality in the local region around the sharp corners of the building for both tetrahedral and polyhedral meshes. As a result, the boundary layer mesh did not lead to the expected improvement of numerical accuracy of wind velocity in the sensitive region of the separated flow from the sharp corners.
•The effects of cell types and boundary layer mesh on reproducing the pedestrian-level wind environment were analyzed.•The polyhedral mesh is most economical for computational resources while acceptable accuracy can be maintained.•The boundary layer mesh was found to worsen the mesh quality in the local region around the sharp corners of the building.•The boundary layer mesh in the near-ground region is more necessary for the tetrahedral mesh than the polyhedral mesh.
In this review, the synthesis and optoelectronic properties of various π‐conjugated‐, σ‐conjugated‐, pendanted‐, and hyperbranched or dendritic silole‐containing polymers (SCPs) are described. So ...far, substituted silole, dibenzosilole, dithienosilole, and bis‐silicon‐bridged stilbene have been incorporated into SCPs. The tunable bandgaps from 4.0–1.55 eV, variable fluorescent colors from UV to blue, green, and red (RGB) light, fluorescent chemo‐sensors for 2,4,6‐trinitrotoluene (TNT)‐type explosives, aggregation‐induced emission, efficient electroluminescence emissions for RGB lights, phosphorescent hosts with high triplet energy level, efficient solar cells, stable field‐effect transistors with high hole mobility in air, and attenuation of strong laser power, are the important features of SCPs.
Regarding the inherent structure of some nonpolluting resources such as fuel cell (FC) stacks and photovoltaic (PV) panels, the output exhibits a low voltage, which cannot be employed in the common ...conventional utilizations. Accordingly, an interference dc-dc converter is extremely required. This paper demonstrates the feasibility of using an ultra-high-voltage-gain dc-dc converter in either the FC or the PV applications. While keeping the high voltage gain, the proposed topology illustrates low switches' voltage stress resulted in high efficiency. The continuous and discontinuous conduction operation modes, as well as efficiency analysis, are investigated. The prototype setup of 250 W and 400 V output voltage is implemented. The proposed dc-dc converter merits involving ultra-high-voltage ratio, low switches' voltage stress, and high efficiency are verified via experimental results.
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