Severe outbreaks of hand, foot and mouth disease (HFMD) have occurred in China for decades. Our understanding of the HFMD transmission process and its determinants is still limited. In this paper, ...factors that affect the local variation of HFMD transmission process were studied. Three classes of factors, including meteorological, demographic and public health intervention factors, were carefully selected and their effects on HFMD transmission were investigated with Pearson's correlation coefficient and multiple linear regression models. The determining factors for the variation of HFMD transmission were different for the southeastern and the northwestern regions of China. In the northwest, fadeouts occurred yearly, and the average age at infection and the fadeout were negatively correlated with the population density. In the southeast, HFMD transmission was governed by the combined effects of the birth rate, the relative humidity and the interaction of the Health System Performance and the log of the population density. When the Health System Performance was low, HFMD transmission increased with the population density, but when the Health System Performance was high, the better health performance counteracted the transmission increase due to the higher population density.
As one of the most critical elements in the hydrological cycle, real-time and accurate rainfall measurement is of great significance to flood and drought disaster risk assessment and early warning. ...Using commercial microwave links (CMLs) to conduct rainfall measure is a promising solution due to the advantages of high spatial resolution, low implementation cost, near-surface measurement, and so on. However, because of the temporal and spatial dynamics of rainfall and the atmospheric influence, it is necessary to go through complicated signal processing steps from signal attenuation analysis of a CML to rainfall map. This article first introduces the basic principle and the revolution of CML-based rainfall measurement. Then, the article illustrates different steps of signal process in CML-based rainfall measurement, reviewing the state of the art solutions in each step. In addition, uncertainties and errors involved in each step of signal process as well as their impacts on the accuracy of rainfall measurement are analyzed. Moreover, the article also discusses how machine learning technologies facilitate CML-based rainfall measurement. Additionally, the applications of CML in monitoring phenomena other than rain and the hydrological simulation are summarized. Finally, the challenges and future directions are discussed.
Metal aromatic substances play a unique and important role in both experimental and theoretical aspects, and they have made tremendous progress in the past few decades. The new aromaticity system has ...posed a significant challenge and expansion to the concept of aromaticity. From this perspective, based on spin-polarized density functional theory (DFT) calculations, we systematically investigated the doping effects on the reduction reactions of N2O catalyzed by CO for M13@Cu42 (M = Cu, Co, Ni, Zn, Ru, Rh, Pd, Pt) core–shell clusters from aromatic-like inorganic and metal compounds. It was found that compared with the pure Cu55 cluster, the strong M–Cu bonds provide more structural stability for M13@Cu42 clusters. Electrons that transferred from the M13@Cu42 to N2O promoted the activation and dissociation of the N–O bond. Two possible reaction modes of co-adsorption (L-H) and stepwise adsorption (E-R) mechanisms over M13@Cu42 clusters were thoroughly discovered. The results showed that the exothermic phenomenon was accompanied with the decomposition process of N2O via L-H mechanisms for all of the considered M13@Cu42 clusters and via E-R mechanisms for most of the M13@Cu42 clusters. Furthermore, the rate-limiting step of the whole reactions for the M13@Cu42 clusters were examined as the CO oxidation process. Our numerical calculations suggested that the Ni13@Cu42 cluster and Co13@Cu42 clusters exhibited superior potential in the reduction reactions of N2O by CO; especially, Ni13@Cu42 clusters are highly active, with very low free energy barriers of 9.68 kcal/mol under the L-H mechanism. This work demonstrates that the transition metal core encapsulated M13@Cu42 clusters can present superior catalytic activities towards N2O reduction by CO.
► Elastic moduli are correlated with Vickers hardness for covalent materials. ► Linear relationships between shear/Young’s modulus and Vickers hardness are fitted. ► Hardness of some potential ...superhard compounds is predicted.
From a statistical manner, we collected and correlated experimental bulk (
B), shear (
G), Young’s modulus (
E), and ductility (
G/
B) with Vickers hardness (
H
v
) for a number of covalent materials and fitted quantitative and simple
H
v
–
G and
H
v
–
E relationships. Using these experimental formulas and our first-principles calculations, we further predicted the microhardness of some novel potential hard/superhard covalent compounds (BC
2N, AlMgB
14, TiO
2, ReC, and PtN
2). It was found that none of them are superhard materials (
H
v
⩾
40
GPa) except BC
2N. The present empirical formula builds up a bridge between Vickers hardness and first-principles calculations that is useful to evaluate and design promising hard/superhard materials.
RIP3 activation leads to activation of necroptosis and the NLRP3 inflammasome pathways. The activation of RIP3 in lupus nephritis (LN) has not been investigated. In this study, RIP3 and necroptosis ...pathway activations were demonstrated in podocytes in renal biopsies from patients with class IV LN and in the diseased kidneys from lupus-prone NZM2328 and MRL/lpr mice. RIP3 activation was accompanied with the activation of MLKL, the effector molecule of the necroptosis pathway, and activation of caspase-1, the effector of the NLRP3 inflammasome pathway. Podocyte activation of RIP3 was detected readily with the development of LN in NZM2328 mice, suggesting this activation may play a significant role in the pathogenesis of LN. GSK872, a RIP3 specific inhibitor, inhibited the development of LN in MRL/lpr mice with down-regulation of RIP3 activation in podocytes, decreased the splenic sizes and weights and anti-dsDNA antibody titers. IgG from pooled sera of diseased NZM2328 mice succumbing to LN induced both the necroptosis pathway and NLRP3 inflammasome activation in a podocyte cell line and this activation was specifically blocked by GSK872. These results indicate that the necroptosis pathway and the RIP3 dependent NLRP3 inflammasome pathway are activated in podocytes during LN. Inhibition of RIP3 kinase may be a novel therapeutic approach to treat LN and systemic lupus erythematosus (SLE).
•Necroptosis and NLRP3 inflammasome pathways are activated in podocytes in LN.•RIP3 regulates both NLRP3 inflammasome and necroptosis activation.•IgG from LN activates RIP3 dependent necroptosis and NLRP3 inflammasome pathways.•Inhibition of RIP3 reduces autoimmunity and alleviates clinical manifestation of LN.
Exploring stable two-dimensional materials with appropriate band gaps and high carrier mobility is highly desirable due to the potential applications in optoelectronic devices. Here, the electronic ...structures of phosphorene on a Au(111) substrate are investigated by scanning tunneling spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations. The substrate-induced phosphorene superstructure gives a superlattice potential, leading to a strong band folding effect of the sp band of Au(111) on the band structure. The band gap could be clearly identified in the ARPES results after examining the folded sp band. The value of the energy gap (∼1.1 eV) and the high charge carrier mobility comparable to that of black phosphorus, which is engineered by the tensile strain, are revealed by the combination of ARPES results and DFT calculations. Furthermore, the phosphorene layer on the Au(111) surface displays high surface inertness, leading to the absence of multilayer phosphorene. All these results suggest that the phosphorene on Au(111) could be a promising candidate, not only for fundamental research but also for nanoelectronic and optoelectronic applications.
Silicene monolayers grown on Ag(111) surfaces demonstrate a band gap that is tunable by oxygen adatoms from semimetallic to semiconducting type. With the use of low-temperature scanning tunneling ...microscopy, we find that the adsorption configurations and amounts of oxygen adatoms on the silicene surface are critical for band gap engineering, which is dominated by different buckled structures in √13 × √13, 4 × 4, and 2√3 × 2√3 silicene layers. The Si–O–Si bonds are the most energy-favored species formed on √13 × √13, 4 × 4, and 2√3 × 2√3 structures under oxidation, which is verified by in situ Raman spectroscopy as well as first-principles calculations. The silicene monolayers retain their structures when fully covered by oxygen adatoms. Our work demonstrates the feasibility of tuning the band gap of silicene with oxygen adatoms, which, in turn, expands the base of available two-dimensional electronic materials for devices with properties that is hardly achieved with graphene oxide.
To understand the nucleation of carbon atoms to form graphene on transition metal substrates during chemical vapor deposition (CVD) synthesis, carbon clusters supported on Ni(111) surfaces, namely ...CN@Ni(111) (where N ≤ 24), were explored systematically using density functional theory (DFT) calculations. Very different from the freestanding C clusters, on a Ni(111) surface, the C chain configuration is superior to the C ring formation and dominates the ground state until N > 12. A ground state structural transition from a one-dimensional C chain to a two-dimensional sp2 network (or graphene island) occurs at N = 12. It is surprising that incorporating one to three 5-membered-rings (5MRs) or pentagons into a graphene island is required to achieve the energetically most stable structure. This deep insight into the supported C cluster formation is crucial for understanding the growth mechanism of graphene on a transition metal surfaces in CVD experiments and the experimental design of CVD graphene growth.
ObjectivesMalaria is a vector-borne disease that remains a serious public health problem due to its climatic sensitivity. Accurate prediction of malaria re-emergence is very important in taking ...corresponding effective measures. This study aims to investigate the impact of climatic factors on the re-emergence of malaria in mainland China.DesignA modelling study.Setting and participantsMonthly malaria cases for four Plasmodium species (P. falciparum, P. malariae, P. vivax and other Plasmodium) and monthly climate data were collected for 31 provinces; malaria cases from 2004 to 2016 were obtained from the Chinese centre for disease control and prevention and climate parameters from China meteorological data service centre. We conducted analyses at the aggregate level, and there was no involvement of confidential information.Primary and secondary outcome measuresThe long short-term memory sequence-to-sequence (LSTMSeq2Seq) deep neural network model was used to predict the re-emergence of malaria cases from 2004 to 2016, based on the influence of climatic factors. We trained and tested the extreme gradient boosting (XGBoost), gated recurrent unit, LSTM, LSTMSeq2Seq models using monthly malaria cases and corresponding meteorological data in 31 provinces of China. Then we compared the predictive performance of models using root mean squared error (RMSE) and mean absolute error evaluation measures.ResultsThe proposed LSTMSeq2Seq model reduced the mean RMSE of the predictions by 19.05% to 33.93%, 18.4% to 33.59%, 17.6% to 26.67% and 13.28% to 21.34%, for P. falciparum, P. vivax, P. malariae, and other plasmodia, respectively, as compared with other candidate models. The LSTMSeq2Seq model achieved an average prediction accuracy of 87.3%.ConclusionsThe LSTMSeq2Seq model significantly improved the prediction of malaria re-emergence based on the influence of climatic factors. Therefore, the LSTMSeq2Seq model can be effectively applied in the malaria re-emergence prediction.
Uncovering the thickness‐dependent electronic property and environmental stability for 2D materials are crucial issues for promoting their applications in high‐performance electronic and ...optoelectronic devices. Herein, the extrahigh air stability and giant tunable electronic bandgap of chemical vapor deposition (CVD)–derived few‐layer PdSe2 on Au foils, by using scanning tunneling microscope/spectroscopy (STM/STS), are reported. The robust stability of 2D PdSe2 is uncovered by the observation of nearly defect/adsorption‐free atomic lattices on long‐time air‐exposed samples. A one‐to‐one correspondence between the electronic bandgap (from ≈1.15 to ≈0 eV) and thickness of PdSe2/Au (from bilayer to bulk) is established. It is also revealed that few‐layer semiconducting PdSe2 flakes present zero‐gap edges, induced by hybridization of Pd 4d and Se 4p orbitals. This work hereby provides straightforward evidence for the thickness‐tunable electronic property and air stability of 2D semiconductors, thus shedding light on their applications in next‐generation electronic devices.
The thickness‐dependent electronic property and environmental stability for 2D PdSe2/Au are unveiled by scanning tunneling microscope/spectroscopy. The robust stability of 2D PdSe2 is uncovered on long‐time air‐exposed samples. Particularly, a one‐to‐one correspondence between the electronic bandgap and thickness of PdSe2/Au is established. Besides, zero‐gap edges are observed in the PdSe2 flakes on Au foils.
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