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Solar-induced chlorophyll fluorescence (SIF) provides a means to estimate plant photosynthetic activities and to detect early plant stress. The accurate quantification of SIF emitted by various scene components (tree crowns and background) may significantly improve the interpretation of top-of-canopy SIF (SIFtoc) measurements made over heterogeneous canopies. To do so, a three-dimensional (3-D) canopy SIF model (FluorFLiES) was introduced by coupling the excitation-fluorescence matrices (EF-matrices) with a 3-D Monte Carlo canopy radiative transfer model (Forest Light Environmental Simulator, FLiES). A tool was developed to construct forest canopy scene components from LiDAR data and enable their simulated contributions in structurally complex forest scenes. FluorFLiES is able to quantify SIF measurements with good accuracy at both half-hourly (R2 = 0.72, RMSE = 0.26 mW m−2 sr−1 nm−1) and daily (R2 = 0.83, RMSE = 0.19 mW m−2 sr−1 nm−1) scales. This study showed that non-photosynthetic elements in tree crowns, the fractional vegetation cover (FVC), and the background (including understory vegetation and soils) had a strong influence on SIFtoc intensity. Non-photosynthetic woody material suppressed the propagation of photons within crowns, thereby decreasing SIFtoc by around 10%. The canopy background made a significant contribution to SIFtoc in the NIR region by scattering downward SIF photons upward, and the background contribution increased rapidly with decreasing FVC: SIFtoc increased two-fold from 0.15 to 0.3 mW m−2 sr−1 nm−1 when ground leaf area index increased from 0.5 to 1.5 m2/m2. The results showed that the fluorescence escape ratio (fesc), a key variable relating observed SIFtoc to photosynthesis CO2 rate, contained a contribution from the background with a magnitude of 42%, even for relatively dense forest canopies. Assuming fesc simulated by the FluorFLiES model as a reference value, this study demonstrated that the current reflectance-based approach may cause large uncertainties (29%) when understory vegetation and/or FVC changes, largely due to neglecting the contribution of background elements. This study highlights the need to separate scene components and to consider multiple scattering within/among these components in interpreting the SIFtoc signal when working with heterogeneous ecosystems. The source code of FluorFLiES is available for further benchmarking.

The polysulfides shuttling and slow redox kinetics of sulfur-based cathodes have severely hindered the commercialization of lithium-sulfur (Li-S) batteries. Herein, distinctive three-dimensional microspheres composed of boron nitride (BN) nanosheets and reduced graphene oxide (rGO) were applied to act as efficient sulfur cathode hosts for the first time using in a spray-drying process. Using this construction, the robust microsphere structure could shorten ion diffusion pathways and supply sufficient spaces to alleviate the volumetric expansion of sulfur during lithiation. Besides, the synergistic effect between BN and rGO significantly enhanced polysulfides adsorption capability and accelerated their conversion, verified by the density functional theory (DFT) calculations and adsorption experiments. Consequently, the S-BN@rGO cathode could manifest the high initial capacity (1137 mAh g-1 at 0.2 C) and remarkable cycling/stability performance (572 mAh g-1 at 1 C after 500 cycles). These results shed light on a design concept of high-performance sulfur cathode host materials.

Photosynthesis plays a crucial role in regulating the global carbon cycle and mitigating climate change. The diurnal variation in photosynthesis provides key information on the responses of ecosystems to environmental drivers, but there is a critical gap in the large-scale estimation of diurnal photosynthesis. In the last decade, satellite estimates of solar-induced chlorophyll fluorescence (SIF) have been found to mimic the seasonality of photosynthesis. Recently, the deployment of the Orbiting Carbon Observatory-3 (OCO-3) on the International Space Station has provided the opportunity to retrieve SIF at different times of the day. Here we utilized OCO-3 measurements to estimate and analyze diurnal cycles of SIF and gross primary production (GPP) at the global scale. We first mitigated the sun-sensor geometry effects on nadir-mode OCO-3 SIF (SIFnadir) at the sub-diurnal scale (hourly) by deriving the total canopy SIF emission (SIFtotal) using radiative transfer theory. Next, we generated the spatially and temporally continuous hourly SIFnadir and SIFtotal using artificial neural networks under clear-sky conditions, whose extrapolation ability was evaluated using the data from independent years. Compared with SIFnadir, the diurnal relationship between clear-sky SIFtotal and GPP from 38 homogeneous flux sites had smaller variations in the slope (the coefficient of variation was 0.07 vs 0.19). In addition, a correction to account for the bias between clear-sky and overcast conditions was used to estimate all-sky GPP from clear-sky SIFtotal and the resulting GPP was strongly correlated with tower GPP (R2 = 0.75; RMSE = 3.53 μmol/m2/s). Our results demonstrated that the new OCO-3 SIF trained GPP product (GPPSIF) was able to depict the diurnal pattern of photosynthesis globally, capturing also the physiologically hysteresis or afternoon depression of photosynthesis. By doing so, hourly GPPSIF has the potential to improve the modeling of terrestrial photosynthesis and the projection of the global carbon cycle under climate change.

Developing low-cost and high-efficiency bifunctional electrocatalysts for both oxygen evolution and reduction reactions is urgent to fulfill the practical application of rechargeable Zn-air batteries (ZABs). However, to explore the high catalytic performance of air electrocatalysts still remains a challenge. In response, a three-dimensionally ordered macroporous (3DOM) Co3O4 electrocatalyst is designed and synthesized through a nanocasting strategy. A well-controlled phosphorization treatment is further conducted to induce defect engineering on the resulting P-doped Co3O4–δ (3DOM P-Co3O4–δ). With the oxygen vacancy (Vo) tailoring, partial reduction from Co3+ to Co2+ is verified as the key to improving the intrinsic electrocatalytic bifunctionality. By incorporating the geometric and electronic merits, 3DOM P-Co3O4–δ possesses an ORR half-wave potential of 0.82 V and an OER overpotential of 366 mV to achieve 10 mA cm–2, which is comparable to noble-metal benchmarks. Particularly, under galvanostatic cycling measurements, ZABs using 3DOM P-Co3O4–δ containing air cathode showcase a potential gap of 0.84 V with negligible voltage fading over 250 h at 10 mA cm–2.

Due to the demands for high performance and ecological and economical alternatives to conventional lithium-ion batteries (LiBs), the development of lithium-sulfur (Li-S) batteries with remarkably higher theoretical capacity (1675 mA h g−1) has become one of the extensive research focus directions worldwide. However, poor conductivity of sulfur, critical cyclability problems due to shuttle of polysulfides as intermediate products of the cathodic reaction, and large volume variation of the sulfur composite cathode upon operation are the major bottlenecks impeding the implementation of the next-generation Li-S batteries. In this work, a unique three-dimensional (3D) interconnected macrocellular porous carbon (PC) architecture decorated with metal Ni nanoparticles was synthesized by a simple and facile strategy. The as-fabricated Ni/PC composite combines the merits of conducting carbon skeleton and highly adsorptive abilities of Ni, which resulted in efficient trapping of lithium polysulfides (LiPSs) and their fast conversion in the electrochemical process. Owing to these synergistic advantageous features, the composite exhibited good cycling stability (512.3 mA h g−1 after 1000 cycles at 1 C with an extremely low capacity fading rate 0.03 % per cycle), and superior rate capability (747.5 mA h g−1 at 2 C). Accordingly, such Ni nanoparticles embedded in a renewable puffed corn-derived carbon prepared via a simple and effective route represent a promising active type of sulfur host matrix to fabricate high-performance Li-S batteries.

With the rapid development of flexible and wearable electronics, flexible zinc-air battery technology attracts ever-increasing attention and is considered as one of the most promising energy storage systems. However, its practical application is still at the preliminary stage. In this review, the basic battery configurations and design principles are discussed for flexible zinc-air battery, followed by challenges and recent progresses in developing each battery component, in terms of polymer electrolyte, metal anode and air cathode. An overview of flexible zinc-air battery is provided here with the aim to present a clear picture of current research directions.

The switch/sugar nonfermenting (SWI/SNF) family of chromatin remodeling complexes have been implicated in normal hematopoiesis. The ARID2 protein is a component of the polybromo-associated BAF (PBAF), one of the two main SWI/SNF complexes. In the current study, we used a conditional Arid2 knockout mouse model to determine its role in normal hematopoiesis. We found that the loss of Arid2 has no discernable effects on steady-state hematopoiesis, with the exception of a modest effect on erythropoiesis. On bone marrow transplantation, however, the loss of Arid2 affects HSC differentiation in a cell-autonomous manner, resulting in significant decreases in the ability to reconstitute the lymphoid lineage. Gene expression analysis of Arid2 knockout cells revealed enrichment of myeloid-biased multipotent progenitor (MPP) cell signatures, while the lymphoid-biased MPPs are enriched in the wild type, consistent with the observed phenotype. Moreover, Arid2 knockout cells revealed enrichment of inflammatory pathways with upregulation of TLR receptors, as well as downstream signaling cascade genes. Furthermore, under lymphocyte-biased growth conditions in vitro, Arid2 null bone marrow cells have significantly impaired proliferation, which decreased further on lipopolysaccharide stimulation. Overall, these data suggest that the loss of Arid2 impairs HSC differentiation ability, and this effect may be mediated through upregulation of inflammatory pathways.

It is difficult to predict precisely the frequency response of a complex vibro-acoustic system in mid-frequency region. To overcome this deficiency, a novel hybrid stable node-based smoothed finite element method/statistical energy analysis model is proposed in this work. The whole vibro-acoustic system can be divided into a combination of a structural subsystem with statistical behavior and an acoustic subsystem with deterministic feature. The recently developed stable node-based smoothed finite element method is employed here to simulate the deterministic subsystem, and the statistical energy analysis is utilized to deal with the statistical subsystem. Based on the so-called diffuse field reciprocity relation, these two subsystems can be easily connected and coupled. Due to the introducing of gradient smoothing and compensation operation, our algorithm can significantly reduce the dispersion error compared with the traditional finite element method. Thus, it is expected that the present coupled model can provide ultra-accurate results. Numerical examples, including both benchmark and practical engineering cases, demonstrate that our algorithm works very well in mid-frequency vibro-acoustic analysis.

Although rice cultivation is one of the most important agricultural sources of methane (CH4) and contributes ∼8% of total global anthropogenic emissions, large discrepancies remain among estimates of global CH4 emissions from rice cultivation (ranging from 18 to 115 Tg CH4 yr−1) due to a lack of observational constraints. The spatial distribution of paddy-rice emissions has been assessed at regional-to-global scales by bottom-up inventories and land surface models over coarse spatial resolution (e.g., > 0.5°) or spatial units (e.g., agro-ecological zones). However, high-resolution CH4 flux estimates capable of capturing the effects of local climate and management practices on emissions, as well as replicating in situ data, remain challenging to produce because of the scarcity of high-resolution maps of paddy-rice and insufficient understanding of CH4 predictors. Here, we combine paddy-rice methane-flux data from 23 global eddy covariance sites and MODIS remote sensing data with machine learning to 1) evaluate data-driven model performance and variable importance for predicting rice CH4 fluxes; and 2) produce gridded up-scaling estimates of rice CH4 emissions at 5000-m resolution across Monsoon Asia, where ∼87% of global rice area is cultivated and ∼ 90% of global rice production occurs. Our random-forest model achieved Nash-Sutcliffe Efficiency values of 0.59 and 0.69 for 8-day CH4 fluxes and site mean CH4 fluxes respectively, with land surface temperature, biomass and water-availability-related indices as the most important predictors. We estimate the average annual (winter fallow season excluded) paddy rice CH4 emissions throughout Monsoon Asia to be 20.6 ± 1.1 Tg yr−1 for 2001–2015, which is at the lower range of previous inventory-based estimates (20–32 CH4 Tg yr−1). Our estimates also suggest that CH4 emissions from paddy rice in this region have been declining from 2007 through 2015 following declines in both paddy-rice growing area and emission rates per unit area, suggesting that CH4 emissions from paddy rice in Monsoon Asia have likely not contributed to the renewed growth of atmospheric CH4 in recent years.

The paddy rice fields act as an important anthropogenic source of methane (CH4) to the atmosphere. The study of pattern, magnitude, and environmental controls of CH4 emissions are still insufficient due to limited measurements and understand of underlying drivers for variations of CH4 fluxes at different temporal scales. In this study, CH4 fluxes from a rice-wheat rotation agroecosystem in eastern China were continuously measured using the eddy covariance technique. The diurnal and seasonal variations of CH4 flux and potential controlling factors in 2016 were analyzed using wavelet coherence, conditional Granger causality, correlation analysis and path analysis methods. CH4 fluxes showed distinguishable diurnal variations with single peaks during 13: 00–16: 00 local time. At the diurnal timescale, gross primary productivity (GPP) regulates CH4 fluxes after accounting for the effects of latent heat flux (LE), air temperature (TA), and soil temperature (TS) on CH4 fluxes. LE mirrored the diurnal pattern of CH4 fluxes when the effects of TA and TS on CH4 fluxes were considered. Daily CH4 fluxes exhibited large seasonal variations, with the largest daily CH4 flux of 1191.78 mg C-CH4 m−2 d−1 on 29 July 2016. The daily CH4 fluxes were continuously low in the growing season of wheat, and sharply increased from very low values in late June to peaks in late July and early August, and then gradually decreased to low values at the end of the rice growing season in late November and early December. Correlation analysis and path analysis showed that seasonal variations of soil temperature, air temperature, and GPP had strong effects on daily CH4 fluxes during pre-panicle initiation of the rice growing season, while soil temperature and leaf area index (LAI) had very strong effects on daily CH4 fluxes during the post-panicle initiation stage. The total of CH4 fluxes from the rice-wheat rotation agroecosystem into the atmosphere amounted to 58.08 ± 9.87 g C m−2 in 2016, and the annual net carbon (C) budget and greenhouse gas (GHG) budget were 163.50 ± 9.87 g C m−2 and 2322.53 ± 329.00 g CO2eq m−2, respectively. This study represents a comprehensive assessment of fluxes and drivers of CH4 from a rice-wheat rotation agroecosystem at different timescales. Additionally, the consecutive data of CH4 emission in this region will also useful for model calibration and validation.

Kinetic Monte Carlo (KMC) is a powerful tool for studying catalytic reaction mechanisms. In this work, we present a practical approach for the mechanistic study of catalytic systems under site blocking deactivation through accelerated kinetic Monte Carlo (AKMC). It was used to simulate 31 elementary events proposed for graphene growth on copper, and subsequently validated by comparing graphene growth’s time evolution from simulation with experiments. The AKMC reported in this study, which is capable of accelerating the time evolution of catalytic systems under evolving permanent blocking of active sites, advances the application of KMC for mechanistic studies of systems undergoing catalytic deactivation. Moreover, using this approach, new fundamental insights on the graphene growth mechanism was unveiled, highlighting the role of CH species rather than C adatoms in the growth of graphene.

MicroRNAs (miRNAs) play important regulatory roles during interactions between virus pathogens and host cells, but whether and how they work in the case of foot-and-mouth disease virus (FMDV) is less understood. Based on a microarray-based miRNA profiling in the porcine kidney cell line PK-15, we identified 36 differentially expressed host miRNAs at the early stage of FMDV infection, among which miR-1307 was significantly induced. Functional characterization demonstrated that miR-1307 attenuated FMDV replication. Further experiments proved that miR-1307 specifically promoted the degradation of the viral structural protein VP3 indirectly through proteasome pathway. Moreover, innate immune signaling was activated and expression of immune responsive genes was significantly enhanced in the miR-1307-overexpressing clones. Together, our data demonstrated that miR-1307 suppresses FMDV replication by destabilizing VP3 and enhancing host immune response. Importantly, subcutaneous injection of miR-1307 agomir delayed the FMDV-induced lethality in suckling mice, exhibiting its therapeutic potential to control foot-and-mouth disease (FMD).

Wheat is the most important staple crop grown in Australia, and Australia is one of the top wheat exporting countries globally. Timely and reliable wheat yield prediction in Australia is important for regional and global food security. Prior studies use either climate data, or satellite data, or a combination of these two to build empirical models to predict crop yield. However, though the performance of yield prediction using empirical methods is improved by combining the use of climate and satellite data, the contributions from different data sources are still not clear. In addition, how the regression-based methods compare with various machine-learning based methods in their performance in yield prediction is also not well understood and needs in-depth investigation. This work integrated various sources of data to predict wheat yield across Australia from 2000 to 2014 at the statistical division (SD) level. We adopted a well-known regression method (LASSO, as a benchmark) and three mainstream machine learning methods (support vector machine, random forest, and neural network) to build various empirical models for yield prediction. For satellite data, we used the enhanced vegetation index (EVI) from MODIS and solar-induced chlorophyll fluorescence (SIF) from GOME-2 and SCIAMACHY as metrics to approximate crop productivity. The machine-learning based methods outperform the regression method in modeling crop yield. Our results confirm that combining climate and satellite data can achieve high performance of yield prediction at the SD level (R2 ˜ 0.75). The satellite data track crop growth condition and gradually capture the variability of yield evolving with the growing season, and their contributions to yield prediction usually saturate at the peak of the growing season. Climate data provide extra and unique information beyond what the satellite data have offered for yield prediction, and our empirical modeling work shows the added values of climate variables exist across the whole season, not only at some certain stages. We also find that using EVI as an input can achieve better performance in yield prediction than SIF, primarily due to the large noise in the satellite-based SIF data (i.e. coarse resolution in both space and time). In addition, we also explored the potential for timely wheat yield prediction in Australia, and we can achieve the optimal prediction performance with approximately two-month lead time before wheat maturity. The proposed methodology in this paper can be extended to different crops and different regions for crop yield prediction.

In this work, we report a new type of aqueous sodium-ion batteries employing Na4Mn9O18/carbon nanotube/reduced graphene oxide (NMO/CNT/RGO) composite as a cathode material while zinc metal as anode material. The NMO/CNT/RGO composites are prepared by a spray drying method and possess a microsphere structure. Addition of RGO and CNT significantly improve the electrical conductivity of NMO composite materials. A stable network skeleton structure was formed in the interior and was beneficial to relieve stress and strain caused due to sodium ion movement and significantly improve the electrochemical performance of cathode materials. The initial reversible discharge specific capacity of the ternary composite electrode is 96.2 mAh g−1 at 4 C, and retained 68% capacity after 150 cycles (discharge capacity 65.8 mAh g−1). NMO/CNT/RGO composites have an excellent rate performance and high cycle capacity.

Bismuth vanadate (BiVO4) has been widely used as a photocatalytic semiconductor for oxygen evolution in artificial photosynthesis. In this study, one-dimensional mesoporous BiVO4 nanofibers (BiVO4 NFs) were fabricated by the electrospinning strategy. The NFs were then deposited with NiCo layered double hydroxides (NiCo LDHs) to improve their reaction kinetics, charge transfers, and water oxidation activities. The obtained BiVO4/4 wt%NiCo LDHs composite exhibits enhanced photocatalytic oxygen oxidation activity that is approximately 1.6 times higher than that of BiVO4 NFs, due to the synergistic effects between BiVO4 NFs and NiCo LDHs, which can accelerate the transfer of holes between their surfaces. This design is a promising approach for fabricating large-scale nanofibers with good photocatalytic performance.

Snow cover, which has been declining over recent decades because of rising temperatures, impacts alpine vegetation in various ways on the Tibetan Plateau (TP). However, it is still unclear how the alpine ecosystem responses to the rapid changes of snow cover on the TP. Here, we use the novel spaceborne measurements of solar-induced fluorescence (SIF) from the GOME-2 instrument, a direct proxy of photosynthetic activity, along with traditional vegetation indices (VIs) to study the responses of an alpine ecosystem to changes in snow cover over the TP. We find that seasonal dynamics of SIF are more consistent with alpine vegetation gross primary productivity (GPP) than those of enhanced vegetation index (EVI), suggesting the decoupling of photosynthesis and changes in greenness-based VIs. The snow cover explains most of the interannual variability of SIF, with secondary effects due to summer air temperature, while summer precipitation has little impact on alpine vegetation photosynthesis, indicating the critical role of snow cover in regulating alpine vegetation growth on the TP. This study suggests that the alpine vegetation photosynthesis on the TP is highly dependent on the snow cover at the start of the growing season and air temperature at the end of the growing season. Our results also demonstrate that the on-going satellite measurements of SIF shed new light on the understanding of future vegetation growth and vegetation–atmosphere interactions under a changing climate on the TP.

Herein, magnesium/aluminum (Mg/Al) composite rods were prepared by compound casting and multi-pass warm caliber rolling, and the effect of caliber rolling on the evolution of the interfacial microstructure and mechanical properties of the Mg/Al compound castings was investigated. The results reveal a uniform interface, which can be divided into three layers consisting of Al3Mg2, Al12Mg17 and (Al12Mg17 + Mg) eutectic structure, was formed during the compound casting. Afterwards, the brittle reaction layer fragmented during the rolling process, and was effectively eliminated after 12 passes. Meanwhile, the fresh Al and Mg bases squeezed out and bonded together under the rolling force. The interface formed after the final rolling process had no visible intermetallic compounds. Further, an inhomogeneous deformation in the Mg and Al bases was observed during the rolling process. Initially, the Al clad layer accommodated a larger proportion of the plastic deformation. With increasing number of passes, however, the strain in the Mg core layer increased and, after 12 passes, the deformation of both layers tended to be equivalent. The strength of the Mg/Al composite rod increased gradually and the ultimate tensile stress reached a value of 247 MPa after 12 passes.

Transition metal oxide Cu2O anode is still not meeting the current market demands due to the low theoretical capacity and poor cycle stability. We herein report the synthesis of a nanoporous GeO2/Cu/Cu2O network by a straightforward dealloying method. The resulting material possesses high porosity which served to alleviate the stress incurred during lithiation/delithiation volume variation and presents good conductivity for fast electron transfer. Enhanced electrochemical performance is observed when measured as an anode material, delivering 715 mAh g−1 at 200 mA g−1 after 50 cycles and offered 504 mAh g−1 even at a high current density of 1600 mA g−1 after 150 cycles. Furthermore, the material also demonstrates excellent rate performance of 812, 782, 741, 695, 635 and 552 mAh g−1 at 100, 200, 500, 800, 1600 and 3200 mA g−1 current densities, respectively. The enhanced Li storage performances could be ascribed to the reticular ligament with high porosity, the increased conductivity by Cu as well as the improved capacity from GeO2. Moreover, this work provides us a new material design strategy to fabricate various porous composite anodes with high capacity through a straightforward dealloying method in future for lithium-ion battery applications.

Herein, we demonstrate a facile synthesis process to fabricate and deposit flower-like CuS/graphene nanocomposite on a multi-functional separator for efficient immobilization of polysulfides of lithium/sulfur (Li/S) batteries. Admirably, as-prepared CuS/graphene composite endows enriched oxygen-functional groups and excellent electrical conductivity for cathode area. The introduction of CuS/graphene-coated separator effectively reduced the dissolution of lithium polysulfides as well as enhanced the integrity of the sulfur cathode for Li/S batteries. The cell with these modified separator delivered an enviable discharge capacity of 1302 mAh g−1 at 0.2 C, as well as an excellent reversible capacity of 760 mAh g−1 after 100 cycles. Furthermore, an outstanding rate capability of 568 mAh g−1 at 3.0 C has been achieved in the cell with CuS/graphene-coated separator. The results reveal that CuS/graphene-coated separator shows an admirable potentiality to boost the performance of next-generation Li/S batteries.

Lithium-sulfur (Li-S) batteries represent one of the most promising battery techniques in 21st century. However, the practical implementation of Li-S batteries is impeded by several intractable obstacles including the poor conductivity of sulfur, shuttling behaviour of polysulfides intermediates, and large volume change during sulfur lithiation. Thus, the rational design and morphological control of sulfur cathode paves the way to Li-S batteries practicalizations. Herein, we develop a blackberry-like hollow graphene sphere through spray drying method as a promising sulfur host for Li-S batteries. Attributed to the uniform sulfur distribution, fast reaction kinetics, and excellent sulfur immobilization, the S-HGS composite electrode achieves a highly reversible capacity of 780 mAh g−1, a great rate capability as well as cyclability without adding additives.

Highlights • A Chinese virulent genotype GIIb PEDV strain, CH/HNPJ/2017, was successfully separated and serially propagated in Vero cells. • The biological characteristics and pathogenicity of PEDV strain CH/HNPJ/2017 were determined. • The median pig diarrhea dose (PDD50) of Chinese PEDV strain was first determined. • The immune protective effect of PEDV strain CH/HNPJ/2017 as vaccine candidates was also be evaluated., Since October 2010, severe porcine epidemic diarrhea (PED) outbreaks caused by highly virulent PED virus (PEDV) strains have occurred continuously in the Chinese pig population and caused considerable economic losses. Although PEDV vaccines based on classical PEDV strains have been widely used in China in recent years, the morbidity and mortality in piglets remain high. Therefore, virulent genotype GII PEDV strains that are prevalent in the field should be isolated and used to develop next-generation vaccines. In the present study, a Chinese virulent genotype GIIb PEDV strain, CH/HNPJ/2017, was serially propagated in Vero cells for up to 90 passages. The S genes contained typical insertions and deletions that were also found in other recently isolated highly virulent PEDV strains from China and other countries and had two neighboring unique insertion mutations, which resulted in four amino acid changes in the S1 region of passages P10 and P60. Pig infection studies revealed that the CH/HNPJ/2017 strain was highly virulent in piglets, and the median pig diarrhea dose (PDD50) was 7.68 log10PDD50/3 mL. Furthermore, the cell-adapted CH/HNPJ/2017 strain elicited potent serum IgG and neutralizing antibody responses in immunized pigs when it was used as an inactivated vaccine candidate. In addition, the pigs that received the experimental inactivated vaccines were partially protected (3/5) against subsequent viral challenge. In brief, these data indicate that the CH/HNPJ/2017 strain is a promising candidate for developing a safe and effective PEDV vaccine in the future.

Highlights • Origin and genomic organization of the miR-34/449 family in vertebrates. • Expression of the mir-34/449 family regulated by viral infection. • Virus replication regulated by the mir-34/449 family. • Inflammatory responses regulated by the miR-34/449 family after viral infection., MicroRNAs are short, endogenous, nonprotein-coding RNAs that are essential for regulation of cellular processes through gene silencing. The miR-34/449 family is conserved in mammalian organisms and generally comprises six homologous genes: miR-34a, miR-34b, miR-34c, miR-449a, miR-449b and miR-449c, at three genomic loci. Strong similarity in the sequence of these miRNAs, particularly at the seed region, predicts robust functional redundancy. A large proportion of the literature on the miR-34/449 family focuses on its role in regulating cell cycle arrest and apoptosis by modulating E2F- and p53-related signaling pathways. A growing subset of the literature reports that the miR-34/449 family is involved in the regulation of immune responses and viral infections, and data suggest the potential for miR-34/446 as a diagnostic and therapeutic target. In this review, we discuss our current understanding of the conservation and transcriptional regulation of the miR-34/449 family and review the literature on its functions in viral infections.

Solar-induced chlorophyll fluorescence (SIF) has shown great potential for detecting changes in vegetation function under herbicide stress. However, how physiological (ΦF, canopy SIF emission efficiency) and non-physiological (e.g., structure and illumination) dynamics regulate canopy SIF, and the coupling between SIF and gross primary production (GPP) under herbicide stress remains unclear. Here, we conducted continuous eddy covariance flux and far-red SIF measurements during the early stage of maize in an herbicide-resistant maize field, where herbicide exclusively affects weeds. We investigated the performance of SIF, GPP, and vegetation indices (VIs) in capturing herbicide stress and then explored the sensitivity of SIF to the effects of herbicide treatments by disentangling canopy SIF into the physiological (ΦF) and non-physiological components (NIRvP). We found that SIF rapidly increased in response to the herbicide and that GPP decreased, and that both were more responsive than VIs in capturing the early effects of herbicides. Thus, the opposing responses in SIF and GPP disrupted their otherwise linear relationship during herbicide treatment. More importantly, we found that the increased ΦF dominated the variation of SIF during the early stages of herbicide stress, while the influence of NIRvP was prominent in the variability of SIF in the absence of herbicide. By unraveling its physiological and non-physiological contributions, our findings advance our understanding of how SIF responds to herbicide stress in heterogeneous cropland and will improve our interpretation of SIF as a tool for monitoring photosynthesis.

Karst ecosystems occupy approximately 20% of the Earth's land surface with the unique and vulnerable geomorphological and hydrogeological characteristics. To date, it remains a challenge to accurately monitor ecosystem productivity from space, as well as their responses to the environmental conditions due to climate change and anthropogenic pressure, which is pivotal to the sustainable development strategies in global karst areas. Here we use a reconstructed long-term solar-induced chlorophyll fluorescence dataset (SIF) and two satellite-based gross primary productivity (GPP) products to examine the patterns and trends of vegetation productivity within global karst ecosystems, and to assess the relative contributions of different countries to the restoration of these fragile ecosystems over the period 2001–2016. As an effective proxy for terrestrial GPP, SIF reveals a greening trend across most of the world's karst areas. China and the European Union (EU) lead the world in vegetation greening within their karst areas by 78.02% and 42.44%, respectively. The total net increase in SIF shows that China alone accounted for 43.66% with just 7.0% of global karst area. Brazil is the only country with a negative greening trend. Recent land cover changes caused by the grain-for-green programme in China and deforestation in Brazil account for 36.93% and 64.71% of the increases and decreases, respectively. Our results have significant implications for restoring ecosystem productivity in global karst areas.

Sun-induced chlorophyll fluorescence (SIF) is a promising new tool for remotely estimating photosynthesis. However, the degree to which incoming solar radiation and the structure of the canopy rather than leaf physiology contribute to SIF variations is still not well characterized. Therefore, we investigated relationships between SIF and variables that at least partly capture the canopy structure component of SIF. For this, we relied on high-quality SIF observations from ground-based instruments, high-resolution airborne SIF imagery and the most recent satellite SIF products to cover large ranges in spatial and temporal resolution and diverse ecosystems. We found that the canopy structure-related near-infrared reflectance of vegetation multiplied by incoming sunlight (NIRVP) is a robust proxy for far-red SIF across a wide range of spatial and temporal scales. Our findings indicate that contributions from leaf physiology to SIF variability are small compared to the structure and radiation components. Also, NIRVP captured spatio-temporal patterns of canopy photosynthesis better than SIF, which seems to be mostly due to the greater retrieval noise of SIF. Compared to other relevant structural SIF proxies, NIRVP showed more robust relationships to SIF, especially at the global scale. Our results highlight the promise of using widely available NIRVP data for vegetation monitoring and also indicate the potential of using SIF and NIRVP in combination to extract physiological information from SIF.

Aqueous rechargeable batteries (ARBs) have appealed extensive research interests due to its superiorities of high safety, environmental protection and low redox potential. A Zn/Na4Mn9O18 ARB with metal Zn as anode, Na4Mn9O18 (NMO) as cathode and Na+/Zn2+ hybrid-ion as electrolytes has been the focus of attention in recent years. Nevertheless, serious dendrite formation and side reactions impede the application of a Zn anode and the development of the ARBs. In this study, an independent self-supporting defective ZnOx dispersed porous carbon nanofibers (ZnOx@PCNF) is designed as the main body of zinc metal anode to solve this problem. It is revealed from ab initio molecular dynamics simulation (AIMD) that ZnO with oxygen defect can promote the surfacely uniform Zn deposition. In this situation, the ZnOx@PCNF/Zn||Zn symmetrical battery shows high reversibility and free of Zn dendrites. A full cell is assembled by selecting the NMO cathode and ZnOx@PCNF/Zn anode, and it remains a high reversible capacity of 44.5 mAh g−1 after 200 cycles at 4 C, showing one of the best electrochemical performance of ARBs by using Zn-NMO system. The research has important guiding significance for design and fabricate of defects-containing materials and has a positive impact on the exploitation of high performance ARBs.

For investigating the influence of coexisting ions (K+, Mg2+, Ca2+ and SO42−), temperature and their synergistic effect on energy generation by reverse electrodialysis, two series of cells dividing with Yadeshi membranes are fed with different solutions at 10 °C, 25 °C and 40 °C. The presence of K+, Mg2+, Ca2+ and SO42− results in lower open circuit voltage, higher internal resistance and lower maximum power density, and the influence order of ions coexisting with NaCl is Ca2+ > Mg2+ (>SO42−) > K+. With the temperature risen, the open circuit voltage and the internal resistance show a trend of increase and decrease respectively, resulting in a bigger power density. Based on the synergistic effect of coexisting ions and temperature, the maximum power density of the pure NaCl system shows a greater increment (0.15 W m−2) than that of NaCl-CaCl2 (0.10 W m−2) and NaCl-MgCl2 (0.11 W m−2) systems when temperature increases from 10 °C to 40 °C. Furthermore, the transport quantities of ions in each system increased with temperature at different degrees, and the uphill of Ca2+ and Mg2+ was more obvious, which can reasonably explain the different effects of temperature on the maximum power density. Moreover, these results are further verified when simulated concentrated seawater is used for both the Yadeshi- and Fujifilm membranes, and the Fujifilm shows better energy generation performance mainly due to a lower internal resistance.

A hierarchically porous TiO2 matrix was synthesized via a facile dealloying method for high-performance lithium/sulfur batteries. The dealloying processing forms an interconnected porous structure with high porosity (0.39 cm3 g−1) and large surface area (82.39 m2 g−1). The specific structure provides effective contact between sulfur and host material, thus trapping the polysulfide intermediates and suppressing the shuttle effect. The resulting S/TiO2 composites exhibit excellent cycling and rate performance, which maintained 641 mAh g−1 at 200th cycle at 0.2 C, and 600 mAh g−1 at 2.5 C. The coulombic efficiency remains at nearly 99% except for the first cycle. This excellent electrochemical performance of S/TiO2 composites can be attributed to the strong electrostatic attraction between metal-oxygen bond and polysulfides and structural restriction to encapsulate sulfur of hierarchically porous TiO2.

In this work, a series of efficient visible-light-driven WO3/Cu (II) nanofiber photocatalysts, with superior photocatalytic activities for the degradation of dyes and aniline, were prepared by electrospinning and impregnation methods. The impregnation method brought about homogeneous distribution of Cu (II) species on the surface of WO3 nanofibers. The prepared WO3/Cu (II) nanofiber photocatalysts exhibited enhanced visible-light absorption and reduced charge recombination, as compared to pure WO3 nanofibers, due to the interfacial charge transfer (IFCT) effect between the Cu (II) species and WO3. The combined benefits of the grafting Cu (II) species on the surface of WO3, in terms of optical, surface, and texture properties, led to a significant improvement in the photocatalytic activity for the degradation of Rhodamine B (Rh B) and aniline under conditions of visible light irradiation. Upon the irradiation with visible light in the presence of WO3/Cu (II)-2% photocatalyst, the concentration of Rhodamine B (Rh B) decreased from 10 mg/L to 1.5 mg/L, and that of aniline solution decreased from 5 mg/L to 0.728 mg/L over a period of 3 h. And after running five cycles, the concentration of aniline solution could decrease from 5 mg/L to 0.89 mg/L by WO3/Cu (II)-2% photocatalyst.

EGFR T790 M accounts for 50% to 60% of cases of non-small-cell lung carcinoma (NSCLC) resistance to the first-generation EGFR tyrosine kinase inhibitors (TKIs). Hence, identifying novel compounds with activity against TKIs resistant is of great value. In this study, twenty honokiol and magnolol derivatives were isolated from the EtOH extract of Magnolia officinalis and the antiproliferative activity was evaluated on HCC827 (19del EGFR mutation), H1975 (L858 R/T790 M EGFR mutation), and H460 (KRAS mutation) cell lines. Among the isolated compounds, piperitylmagnolol (a 3-substituted magnolol derivative) showed the best antiproliferative activity against those three cell lines with the IC50 values of 15.85, 15.60 and 18.60 μM, respectively, which provided a direction for the structural modification of magnolol. Further structural modification led to the synthesis of thirty-one magnolol derivatives, and compounds A13, C1, and C2 exhibited significant and broad-spectrum antiproliferative activity with the IC50 values ranging from 4.81 to 13.54 μM, which were approximately 4- and 8-fold more potent than those of honokiol and magnolol, respectively. Moreover, their aqueous solubility was remarkably improved with 12-, 400- and 105 fold greater than those of honokiol and magnolol. Anti-tumor mechanism research revealed that these three compounds were able to induce cell cycle arrest at G0/G1 phase, cause efficient apoptosis in H1975 cells, and also prevent the migration of HUVECs in a dose-dependent manner through Cdk2, Cdk4, Cyclin E, and Cyclin D1 inhibition as well as up-regulation of cleaved-PARP and cleaved-caspase 3 levels. In in vivo antitumor activity, C2 (10, 30 and 100 mg/kg, po) dose-dependently inhibited the tumor growth in H1975 xenograft model with the tumor inhibition rate of 46.3%, 59.3% and 61.2% respectively, suggesting that C2 is a potential oral anticancer agent deserving further investigation.

Herein, we report a three-dimensionally (3D) ordered macro-/mesoporous carbon (3DOM-mC) as the ZnO nanoparticles support for the anode material in lithium-ion batteries (LIBs). The 3DOM-mC is synthesized by the typical dual-templating method that combines the hard-templating (silica opal as template) and soft-templating techniques using resol (phenol/formaldehyde) as the carbon source. The prepared 3DOM-mC material having ordered interconnected macropores and mesopores is then applied to support ZnO nanoparticles to form the ZnO/3DOM-mC composite via a simple in situ solution growth approach. In the ZnO/3DOM-mC composite, the ZnO nanoparticles (∼4.5 nm) are evenly dispersed on the macropore walls of the 3DOM-mC. The ZnO/3DOM-mC composite (40 wt% ZnO loading) anode shows an enhanced LIB performance delivering a specific capacity of 973.3 mAh g−1 after 100 cycles and 1396.6 mAh g−1 after 300 cycles at 0.1 C. This good electrochemical performance of the ZnO/3DOM-mC is ascribed to the ordered interconnected macropores of the 3DOM-mC that can provide the rapid diffusion of Li ions and electrolytes and the ordered mesopores that can buffer the volume expansion of ZnO during the cycling operation.

Porous three-dimensional reduced graphene oxide (3D-RGO) was successfully synthesized. After being loaded with sulfur, the as-obtained 3D-S-RGO composite was used as a cathode for Li-S batteries. Due to its unique 3D-structured porous carbon layers with a high surface area, a high sulfur loading (75.8%) was achieved. More importantly, its 3D structure can also serve as a polysulfide storeroom to relieve the shuttle effect. Therefore, compared with regular sulfur-loaded reduced graphene oxide (S-RGO), the 3D-S-RGO cathode exhibits a greatly improved discharge capacity and cycling stability. The 3D-S-RGO cathode delivers an initial discharge capacity of 1140 mAh g−1 at 0.2 C and remains at 790 mAh g−1 after 200 cycles. This study shows that the 3D structure is essential for improving the performance of graphene-based cathodes in Li-S batteries.

Si nanowires (SiNWs) and graphite-like carbon nitride (g-C3N4) are highly promising materials for solar water splitting. In this work, n-type SiNWs (n-SiNWs) are obtained via metal-catalyzed electroless etching. To improve the photoelectrochemical performance of the n-SiNWs, g-C3N4 is deposited on their surface as a coating layer (n-SiNW/g-C3N4). Furthermore, to increase the density of active sites in g-C3N4, barbituric acid (BA) is introduced into precursors before the layer deposition. The n-SiNW/g-C3N4 photoanode shows a negative shift of the onset potential as compared to the bare n-SiNWs. Moreover, a 50% enhancement in the photocurrent density at 1.6V vs. RHE is achieved on the BA-modified n-SiNW/g-C3N4 as compared to the pristine n-SiNW/g-C3N4. Keywords: Water splitting, Si nanowires, Graphite-like carbon nitride, Core/shell nanostructure, Copolymerization modification